• 한국전기전자재료학회논문지
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• 제18권9호
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• pp.793-797
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• 2005

This study introduces Electro-chemical Mechanical Deposition(ECMD) lot making Cu interconnect. ECMD is a novel technique that has ability to deposit planar conductive films on non-planar substrate surfaces. Technique involves electrochemical deposition(ECD) and mechanical sweeping of the substrate surface Preferential deposition into the cavities on the substrate surface nay be achieved through two difference mechanisms. The first mechanism is more chemical and essential. It involves enhancing deposition into the cavities where mechanical sweeping does not reach. The second mechanism involves reducing deposition onto surface that is swept. In this study, we demonstrate ECMD process and characteristic. We proceeded this experiment by changing of distribution of current density on divided water area zones and use different pad types.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.154-159
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• 2001

Nakdong estuary is located at south-eastern coast of the Korea. A lot of sediment from upper river was deposited at this area. It has caused many problems such as changes in topography and tidal current. In this paper, field observation data on tidal currents and sediments were investigated as well as historical topographic changes by dredging and reclamation of the foreshore. Then, the numerical model considered the settling velocity of the suspended solids according to the particle size was applied to examine the characteristic of deposition. The results are as follows : 1. Changes of characteristics of deposition were caused by topographic changes of Nakdong estuary 2. Characteristics of deposition were influenced by river plume and tidal currents. 3. Numerical model which considers settling velocity reappeared distribution of deposition by particle-size. 4. Used model is only resonable for discussion in the quality, so, it is strongly suggested that the new model development is needed including the quatitative deposition processes.

• 한국방재안전학회논문집
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• 제16권4호
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• pp.1-7
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• 2023

본 연구의 목적은 급경사지 사면에서 토석류 재해가 발생했을 때, 토석류 저감 구조물의 효과를 조사한 실험연구이다. 제어 구조물로는 베플 형태를 취하였고, 베플의 설치 기수와 각 제원에 따라서 하류에서의 토석류에 의한 토사퇴적면적과 토사도달거리를 조사한 것이다. 수로의 경사가 급할수록 토사의 퇴적면적과 도달거리가 증가하였고, 토사체적농도가 감소할수록 토사퇴적면적과 토사의 도달거리가 증가하였다. 토사농도가 작은 경우(Cv = 0.5)는 토석류의 액성이 크기 때문에 수로 경사에 따른 차이가 나타났고, 전반적으로 토사체적농도가 클수록 토사퇴적면적과 토사의 도달거리 감소율이 크게 나타났다. 베플의 수를 증가할수록 토사퇴적면적과 도달거리를 약 5~10% 이상 감소하는 것으로 나타남으로서 베플의 토석류 제어능력이 있음을 보여주고 있다. 본 연구의 결과는 급경사지에서 토사재해가 발생할 때 감쇠 또는 제어 구조물을 설치할 때 중요한 정보를 제공할 것이다.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.1-14
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• 1994

Dental calculus which is calcifing and/or calcified dental plaque is divided into supragingival calculus and subgingival calculus according to the position of deposit to gingival margin. Subgingival calculus has more important clinical significance in diagnosis and treatment of periodontal disease than supragingival calculus. In order to investigate the deposition pattern of subgingival calculus on each root surface of different tooth type, extracted 192 teeth due to excessive destruction of periodontal tissue were divided according to tooth type and the deposition pattern of subgingival calculus was classified into linear type, veneer type, scattered type, and aggregated type according to the configuration and the extent of deposit. The difference of percentage between each deposition pattern was statistically analyzed by Chi-Square test. Following results were obtained : l. In maxillary incisors, linear type and aggregated type were predominant deposition pattern of subgingival calculus on labial(45.5%, 36.4%) and palatal(36.4%, 36.4%) root surface, aggreated type(72.7%) was on mesial surface, and aggregated type(54.5%) and scattered type(36.4%) was on distal suface. 2. In mandibular incisors, scattered type, linear type and aggregated type were predominant deposition pattern of subgingival calculus on labial(33.3%, 30.6%, 27.8%) and lingual(36.1%, 30.6%, 25.0%) root surface, aggregated type(33.3%), scattered type(27.8% ), and veneer type(27.8%) were on mesial surface, and aggregated type(38.9%) and scattered type(33.3%) on distal surface. 3. In maxillary peremolars, the predominant deposition patterns of subgingival calculus were linear type(28.6%) on buccal root suface, scattered type(35.7%) and linear type(28.6%) on palatal surface, scattered type(39.3%) on mesial surface, aggregated type(46.4%) on distal surface, and aggregated type(53.6%) on furcation area. 4. In mandibular premolars, scattered type was predominant deposition pattern of subgingival calculus on buccal(39.3%) and lingual(50.0%) root surface, scattered type(32.1%) and aggregated type(32.1% ) were on mesial surface, and aggregated type(42.9%) was on distal surface. 5. In maxillary molars, aggregated type(40.0%) and scattered type(32.5%) were predominat deposition pattern of subgingival calculus on buccal root surface, aggregated type was on distal(40.0%) and furcation area(50.0%), but there was no predominat pattern on palatal and mesial root surfaces. 6. In mandibular molars, aggregated type(39.5%) and scattered type(28.9%) were predominant deposition patterns of subgingival calculus on buccal root surface, aggregated type(36.8%) was on lingual surface, linear type(39.5%) and aggregated type(34.2%) were on furcation area, but there was no predominant pattern on mesial and distal root surfaces.

• 한국방재학회 논문집
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• 제11권2호
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• pp.103-112
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• 2011

본 연구에서는 분포형 강우-유사-유출 모형을 이용하여 격자기반의 유역침식 및 퇴적 공간분포 정보를 획득하고, 유역의 지형학적, 수문기상학적 특성인자가 유역의 침식 및 퇴적에 미치는 영향을 평가한다. 유역의 지형학적 특성을 대표하는 인자로는 유역면적, 지표흐름 이동거리, 국부경사를 선택하였으며, 격자기반의 누적강우량을 수문기상학적 인자로 활용하여 대상유역에서의 침식 및 퇴적의 변동성을 분석한다. 유역면적에 따른 침식 및 퇴적의 변화양상을 분석하기 위해 대상유역은 Strahler 하천 차수법칙에 의해 다수의 소유역으로 구분되었으며, 면적에 따른 변동성을 분석한 결과, 침식 및 퇴적 모두 면적이 커짐에 따라 선형적으로 증가하는 경향을 보였다. 지표흐름의 이동거리 및 국부경사에 따른 침식 및 퇴적양상의 분석 결과, 침식은 유역전반에 걸쳐 비교적 균등하게 발생하였으나 퇴적의 경우 짧은 지표흐름 이동거리 및 완만한 경사를 갖는 하천선 인접 격자에서 집중적으로 발생하였다. 또한 격자별 누적 강우량에 따른 침식 및 퇴적 변동성 분석결과, 강우량이 증가함에 따라 침식은 점진적으로 증가하는 반면 퇴적은 강우량 증감에 따라 불규칙적인 변동성을 나타내었다. 이상의 결과로부터 본 연구에서 선택된 지형학적 인자들은 퇴적과정에 밀접한 관련이 있으며, 강우량은 유역의 침식에 영향을 미치는 매우 중요한 인자임을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.161-161
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• 2011

Titanium (IV) dioxide (TiO2) is one of the most attractive d-block transition metal functional oxides. Many applications of TiO2 such as dye-sensitized solar cells and photocatalyst have been widely investigated. To utilize solar energy efficiently, TiO2 should be well-aligned with a high surface area and promote the charge separation as well as electron transport. Herein, the TiO2 nanotubes were successfully fabricated by a template-directed method. The electrospun PEO(Polyethylene oxide, Molecular weight, 400k)fibers were used as a soft template for coating with titanium dioxide using an atomic layer deposition (ALD) technique. The deposition was conducted onto a template at 50$^{\circ}C$ by using titaniumisopropoxide [Ti(OCH(CH3)2)4; TTIP] as precursors of TiO2. While the as-deposited TiO2 layers onto PEO fibers were completely amorphous with atomic layer deposition, the TiO2 layers after calcination at 500$^{\circ}C$ for 1 h were properly converted into polycrystalline nanostructured hallow TiO2 nanotube. The TiO2 nanotube with high surface area can be easily handled and reclaimed for use in future applications related to solar cell fabrications.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.447-447
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• 2023

Soil organic carbon (SOC) is a critical indicator of soil fertility. Its importance in maintaining ecological balance has received widespread attention. However, global temperatures have risen by 0.8℃ since the late 1800s due to human-induced greenhouse gas emissions, resulting in severe disruptions in SOC dynamics. To study the impacts of temperature variations on SOC and soil respiration, we used the Soil Carbon and Landscape co-Evolution (SCALE) model, which was capable of estimating the spatial distribution of soil carbon dynamics. The study site was located at Heshan Farm (125°20'10.5"E, 49°00'23.1"N), Nenjiang County in Heilongjiang Province, Northeast China. We validated the model using observed soil organic carbon and soil respiration in 2015 and achieved excellent agreement between observed and modeled variables. Our results showed considerable influences of temperature increases on SOC and soil respiration rates at both erosion and deposition areas. In particular, changes in SOC and soil respiration at the deposition area were greater than at the erosion area. Our study highlights that the impacts of temperature elevations are considerably dependent on soil erosion and deposition processes. Thus, it is important to implement effective soil conservation strategies to maintain soil fertility under global warming.

• 열처리공학회지
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• 제34권5호
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• pp.239-244
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• 2021

Following Silicon Carbide, single crystal diamond continues to attract attention as a next-generation semiconductor substrate material. In addition to excellent physical properties, large area and productivity are very important for semiconductor substrate materials. Research on the increase in area and productivity of single crystal diamonds has been carried out using various devices such as HPHT (High Pressure High Temperature) and MPECVD (Microwave Plasma Enhanced Chemical Vapor Deposition). We hit the limits of growth rate and internal defects. However, HFCVD (Hot Filament Chemical Vapor Deposition) can be replaced due to the previous problem. In this study, HFCVD confirmed the distance between the substrate and the filament, the accompanying growth rate, the surface shape, and the Raman shift of the substrate after vapor deposition according to the vapor deposition temperature change. As a result, it was confirmed that the difference in the growth rate of the single crystal substrate due to the change in the vapor deposition temperature was gained up to 5 times, and that as the vapor deposition temperature increased, a large amount of polycrystalline diamond tended to be generated on the surface.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3168-3172
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• 2007

As the minimum feature size decreases, control of contamination by nanoparticles is getting more attention in semiconductor process. Cleaning technology which removes nanoparticles is essential to increase yield. A reference wafer on which particles with known size and number are deposited is needed to evaluate the cleaning process. We simulated particle trajectories in the chamber by using FLUENT and designed a particle deposition system which consists of scanning mobility particle sizer (SMPS) and deposition chamber. Charged monodisperse particles are generated using SMPS and deposited on the wafer by electrostatic force. The experimental results agreed with the simulation results well in terms of particle number and deposition area according to particle size, flow rate and deposition voltage.

• 환경위생공학
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• 제18권3호통권49호
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• pp.64-68
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• 2003

Measurement of dried deposition for air pollutant was investigated in Gwang-ju Health college area for a year. The average value of air pollutants was investigated three times a month. Measured heavy metals and concentration of mass are not corelated. Heavy metals were thrown up air as state of large particles and they were moved by wind. Deposition of heavy metals and deposition velocities were high in the order of Fe > n > Cu > Pb > Cr and Pb > Fe > Cr > Zn > Cu, respectively. The pattems of deposition velocity of heavy metals for a year were much the same as each other except that Pb is faster than others.