• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.67-75
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• 1995

The progress of periodontal disease and the wound healing process after treatment result in alveolar bone bone change. So, detection of it is very important in the diagnosis and the radiograph of periodontal disease. Various effects have been made to assess the subtle alveolar bone change and digital subtraction radiography (DSR) has been reported to be the best method in evaluating it qualitatively and quantitatively. The present study was performed to estimate the detectable alveolar bone change qualitatively with digital subtraction radiography. For the in vitro study, 10 intraoral standard radiographs were taken from porcine dry mandible which a rectangular cortical bone chip of 0.1mm to 1.0mm thickness with 0.1mm increment was attached on the buccal surface. The radiographs without and with bone plates were reviewed at the same time by 10 observers and requested to detect the presence of cortical bone plates. Digital Subtraction radiograph was reviewed subsequently by using the DSR system(digital converter-256 grey-levels,DT 2851,Data Translation Co., U.S.A;IBM 386 ; CCD camera, FOTOVIX, Tamrom Co., Japan). The detectable thickness of cortical bone plate was O.4mm on the intraoral radiograph and 0.2mm on the subtaction images. For the human study, radiographs were taken from patients by using intraoral film holding device and aluminum reference wedge before and 3 month after bone graft and 1 week after osteoplasty. The grey level change was estimated in the subtraction images and calculated to aluminum equivalent thickness. The grey level of the grafted site was higher that that of healthy controls. Average grey levels of change on healthy controls were O.48mm aluminum equivalent. However, the amount of changes in grafted sites were 1.87mm aluminum thickness equivalent and in the site of osteoplasty were -1.49mm aluminum thickness equivalent. In conclusion, digital subtraction radiography was more effective in detecting as subtle change of alveolar bone than intraoral standard radiography. With the aid of quantitative analysis of digital subtraction radiography, alveolar bone resorption of apposition can be estimated during diagnosis and treatment of periodontally diseased patients.

• Tribology and Lubricants
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• 제21권2호
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• pp.53-62
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• 2005

In this study a general Galerkin FE lubrication analysis method was utilized to analyze the complex lubrication performance of a spiral groove seal having an additional inner circular groove, which was designed for a chemical process mixer operating at a low speed of the maximum 500 rpm. Equilibrium seal clearance analyses under varying outer pressure revealed that the seal maintains a certain levitation seal clearance under the outer pressure of more than about 1.5 bar, regardless of a rotating speed. Also, under the normal outer pressure of 11 bar, the axial stiffness of the seal was predicted to have a high value of more than 7.0 e + 07 N/m, regardless of a rotating speed and thereby, the seal is expected to maintain a stable thickness of lubrication film under a certain external excitation acting. A seal levitation test rig was designed and constructed. Experimental results at 500 rpm agreed well with analytical predictions and the applied lubrication analysis method was verified.

• Tribology and Lubricants
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• 제21권1호
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• pp.8-15
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• 2005

In this study a general Galerkin FE lubrication analysis method is utilized to analyze the complex lubrication performance of a spiral groove seal, which is being designed and developed for a high-speed flying object application operating at a high-speed of over 50,000 rpm. As at the equilibrium seal clearance the axial stiffness of the seal is predicted to have almost such a constant high value of $1.04\times10^8\;N/m$ regardless of a rotating speed, the seal is expected to maintain a stable thickness of lubrication film under a certain external excitation acting. Also, as even at an ultra high-speed of 80,000 rpm the axial damping of the seal is shown to have a rotatively high value of 5,775 N-s/m, the dynamic stability of the seal system at the axial degree of freedom is assured well enough.

• 열처리공학회지
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• 제11권3호
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• pp.186-191
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• 1998

An oxidation behavior of 304 and 316 stainless steels were studied in dry air. After solution treatment, specimens were polished up to $1{\mu}m$ $A1_2O_3$ grade and then subjected to oxidation treatment in dry air at $800^{\circ}C{\sim}1200^{\circ}C$. The oxidation behavior between matrix and oxide scale was analyzed with SEM, EDS and XRD. When oxidation treatment was conducted at $1200^{\circ}C$, large thickness of Fe oxide scale was formed on top of surface and fine $(Cr,Fe)_2O_3$ oxide film was formed below it. Cr rich zone existed at interface between metal and $(Cr,Fe)_2O_3$ oxide layer, and it was believed that this zone acted as obstacle to oxidation. Most of Ni was detected at the interface between metal and $(Cr,Fe)_2O_3$ and also detected at the interface between $Fe_2O_3$ and $(Cr,Fe)_2O_3$.

• Journal of Veterinary Science
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• 제23권1호
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• pp.10.1-10.12
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• 2022

Background: Dry eye disease (DED) cannot be diagnosed by a single test because it is a multifactorial disorder of the ocular surface. Although studies on various dry eye tests (DETs) in dogs have been reported, standard criteria have not been established except for the Schirmer tear test 1 (STT-1). Objectives: To establish reference values for DETs in dogs with normal STT-1 values (≥ 15 mm/min) and to analyze the correlation between DETs. Methods: The STT-1 was performed in 10 healthy Beagle dogs (20 eyes). After 20 min, interferometry (IF) for estimating the lipid layer thickness (LLT) of the tear film, tear meniscus height (TMH), non-invasive tear breakup time (NIBUT), and meibomian gland loss rate of the upper eyelid (MGLRU) and lower eyelid (MGLRL), were measured using an ocular surface analyzer. Results: Mean values for STT-1, TMH, and NIBUT were as follows: 21.7 ± 3.4 mm/min, 0.41 ± 0.21 mm, and 19.1 ± 9.5 sec, respectively. The most frequent LLT range, measured by IF, was 30-80 nm (11 eyes), followed by 80 nm (5 eyes) and 80-140 nm (4 eyes). MGLRU ≤ 25% was measured in 11 eyes and 26%-50% in 9 eyes; MGLRL ≤ 25% in 8 eyes and 26%-50% in 12 eyes. Besides positive correlation between TMH and NIBUT (P = 0.038), there were no significant associations between DETs. Conclusions: Data obtained in this study provided normative references that could be useful for diagnosing DED and for further research into correlation between DETs in dogs with DED.

• 생물환경조절학회지
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• 제9권3호
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• pp.156-160
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• 2000

플라즈마 필름은 플라스틱 필름 표면의 유적성을 향상시키기 위하여 고전압처리 되었다. 플라즈마 필름과 계면활성제 필름(대조구)를 각각 직경 25mm 두께 1.5mm 골조 파이프 하우스에 피복하였다. 또한 40일 플러그 육묘된 풋고추를 110cmx25cm 간격으로 정식하였다. 피복시 수온을 7$0^{\circ}C$로 처리된 수적발생 장치에서 나온 수증기가 필름 표면에서 응결되어 흘러내려 비이커에 모인 양을 150분 후에 측정한 결과, 플라즈마 필름에서 2.56mL.100$cm^{-2}$ , 계면활성제 필름에서 0.94mL.100$cm^{-2}$ 이 나왔다. 피복 60일 후 오전 8시 20분에 시설내 필름 표면에 부착된 수적량은 플라즈마 필름에서 0.34mL.100$cm^{-2}$ , 계면활성제필름에서 0.32mL.10$cm^{-2}$ 이었다. 광 투과율은 플라즈마 필름 피복시설이 계면활성제 피복시설 보다 2.0% 높았다. 그리고 시설내 기온은 플라즈마 필름 피복시설이 계면활성제 피복시설 보다 0.5$^{\circ}C$ 높았다. 그러나 상대습도는 차이가 없었다. 풋고추 초장, 엽면적, 건물중 및 초기수량 또한 처리간에 차이가 없었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.67-67
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• 2009

Due to the scaling down of the dielectrics thickness, the leakage currents arising from electron tunneling through the dielectrics has become the major technical barrier. Thus, much works has focused on the development of high k dielectrics in both cases of memories and CMOS fields. Among the high-k materials, $Al_2O_3$ considered as good candidate has been attracting much attentions, which own some good properties as high dielectric constant k value (~9), a high bandgap (~2eV) and elevated crystallization temperature, etc. Due to the easy control of ion energy and flux, low ownership and simple structure of the inductively coupled plasma (ICP), we chose it for high-density plasma in our study. And the $BCl_3$ was included in the gas due to the effective extraction of oxygen in the form of BClxOy compound. In this study, the etch characteristic of ALD deposited $Al_2O_3$ thin film was investigated in $BCl_3/N_2$ plasma. The experiment were performed by comparing etch rates and selectivity of $Al_2O_3$ over $SiO_2$ as functions of the input plasma parameters such as gas mixing ratio, DC-bias voltage and RF power and process pressure. The maximum etch rate was obtained under 15 mTorr process perssure, 700 W RF power, $BCl_3$(6 sccm)/$N_2$(14 sccm) plasma, and the highest etch selectivity was 1.9. We used the x-ray photoelectron spectroscopy (XPS) to investigate the chemical reactions on the etched surface. The Auger electron spectroscopy (AES) was used for elemental analysis of etched surface.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1487-1489
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• 1998

In this paper, thin films of PI were fabricated VDPM of dry processes which are easy to control the film's thickness and hard to pollute due to volatile solvents. From FT-lR, PAA thin films fabricated by VDP were changed to PI thin films by thermal curing. From SEM, AFM and Ellipsometer experimental, as the higher curing temperatures the films thickness decreases and reflectance increases. Therefore, Pl could be fabricated stable by increasing curing temperature. The relative permitivity and dissipation loss factor were 3.7 and 0.008. Also, the resistivity was about $1.05{\times}10^{15}{\Omega}cm$ at $30^{\circ}C$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.27-27
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• 1998

진공기술의 응용과 진공환경의 이용은 더 이상 논하지 않더라도 산업 전반에 그 충요성이 점점 더 커가고 있다. 이러한 여건에도 불구하고 진공율 이용하는 system 개밟의 국산화는 수 입하는 system으$\mid$ 수에 비하여 절대적으로 부족하며, 또한 개발하는 system의 자동화는 거의 이 루어지지 않고 있으며, 자동화된 진공판련 system은 거의 대부분 수입에 의흔하고 있다. 실험 실 규모에서부터 System올 하나하나 개밭하고, 이톨 자동화하는 노력과 일이 진행됨다면 산업 응용에 있어서도 자연스럽게 자동화된 system으$\mid$ 개발이 이루어 질 것이다 .. system 자동화는 상 품수명의 단축과 이에 따른 다품종 소량을 요구하는 시장수요에 대응하고, 인력절감과 고풀짙 화로 생산성 향상의 요구에 대응하기 위하여 필요하다. 본 연 구에 서 는 e-beam evaporator로 evaporation하면 서 ion beam으로 assist하여 thin film율 제 작하는 IBAD vacuum system율 싫 계 및 제 작하고[1,2], PLC[3,떼톨 이 용하여 system 자동화톨 하였다 .. thin film 제작 process는 먼저 기본 진공상태로 만뚫고 난 뒤, e-beam evaporator로 e evaporation하면서 ion beam source로 assist하여 substrate 011 thin film율 제조한다 226;. thin film올 제 조하면서 thickness monitor로 sample의 thickness rate톨 control 하고, sample의 균얼성과 밀착 성을 고려하여 substrate톨 rotation 및 heating 할 수 있도록 싫계, 제작하였다. 양질의 박막올 제조하기 위해서 진공환경이 좋은 상태로 제공되어야 한다. 이톨 위하여 oil free operation 0 I 가 능한 dry pump와 turbo molecular pump로 고진공 배기 하였다. 진공도의 흑점은 thermal effect 툴 고려하여 cold cathode ion gauge률 사용하였고, intro chamber와 main chamber 사이에는 g gate valve톨 설치하여 벌도로 운용되도록 하였다. 이러한 process를 박막의 두께, 진공도, 시 간, 온도, 공정 동의 조건올 기훈으로 자동화한 것이다. 또한 정전과 단수에 대한 interlock 기능 도 고려하였다.하였다.

• 한국세라믹학회지
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• 제46권1호
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• pp.30-34
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• 2009

A Sand blasting technology has been used to address via and trench processing of glass wafer of optic semiconductor packaging. Manufactured sand blast that is controlled by blast nozzle and servomotor so that 8" wafer processing may be available. 10mm sq test device manufactured by Dry Film Resist (DFR) pattern process on 8" glass wafer of $500{\mu}m's$ thickness. Based on particle pressure and the wafer transfer speed, etch rate, mask erosion, and vertical trench slope have been analyzed. Perfect 500 um tooling has been performed at 0.3 MPa pressure and 100 rpm wafer speed. It is particle pressure that influence in processing depth and the transfer speed did not influence.