• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
• /
• pp.452-455
• /
• 2002

Single crystal 3C-SiC(cubic silicon carbide) thin-films were deposited on Si(100) substrate up to a thickness of $4.3{\mu}m$ by APCVD method using HMDS(hexamethyildisilane) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like crystal surface. The growth rate of the 3C-SiC films was $4.3{\mu}m/hr$. The 3C-SiC epitaxical films grown on Si(100) were characterized by XRD, AFM, RHEED, XPS and raman scattering, respectively. The 3C-SiC distinct phonons of TO(transverse optical) near $796cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The heteroepitaxially grown films were identified as the single crystal 3C-SiC phase by XRD spectra$(2{\theta}=41.5^{\circ})$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.533-536
• /
• 2001

Single crystal cubic silicon carbide(3C-SiC) thin film were deposited on Si(100) substrate up to a thickness of 4.3 $\mu\textrm{m}$ by APCVD(atmospheric pressure chemical vapor deposition) method using hexamethyildisilane(HMDS) at 1350$^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like. The growth rate of the 3C-SiC films was 4.3 $\mu\textrm{m}$/hr. The 3C-SiC epitaxical layers on Si(100) were characterized by XRD(X-ray diffraction), raman scattering and RHEED(reflection high-energy electron diffraction), respectively The 3C-SiC distinct phonons of TO(transverse optical) near 796 cm$\^$-1/ and LO(longitudinal optical) near 974${\pm}$1 cm$\^$-1/ were recorded by raman scattering measurement. The deposition films were identified as the single crystal 3C-SiC phase by XRD spectra(2$\theta$=41.5$^{\circ}$). Also, with increase of films thickness, RHEED patterns gradually changed from a spot pattern to a streak pattern

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
• /
• pp.30-34
• /
• 2002

Single crystal 3C-SiC(cubic silicon carbide) thin-films were deposited on Si(100) wafers up to a thickness of 4.3 ${\mu}m$ by APCVD method using HMDS(hexamethyldisilane) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like crystal surface. The growth rate of the 3C-SiC films was 4.3 ${\mu}m$/hr. The 3C-SiC epitaxial films grown on Si(100) were characterized by XRD, AFM, RHEED, XPS and raman scattering, respectively. The 3C-SiC distinct phonons of TO(transverse optical) near 796 $cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The heteroepitaxially grown films were identified as the single crystal 3C-SiC phase by XRD spectra($2{\theta}=41.5^{\circ}$).

• 한국환경과학회지
• /
• 제8권1호
• /
• pp.75-81
• /
• 1999

In recent years increasing production and disposal of wastewater have caused an accelerated eutrophication of receiving waters. Therefore, in order to alleviate the detrimental impact of wastewater discharge, there is an increasing demand for removing the main nutrients, nitrogen and phosphorus, as well as the organic content of the waste water prior to disposal. This is effectively achieved by extended conventional treatment technology. However, the working expenses and energy requirements of such advanced treatment systems are rather high. So in a sparsely populated rural community is required development of wastewater treatment system combined with the regional characteristics. In this study, the systems are planted with Reeds and Amaryllis In A.C and estimated purification potential of system. The results obtained are as follows. BOD removal rate is 20% in the early stage, the last removal rate is 35% in A.C process and is 65% in Amaryllis+A.C process and is 50% in Reed+A.C process. T-N removal rate by Amaryllis is average 2.6g/$m^3$ㆍd, T-N removal rate by Reed is average 1.76g/$m^3$ㆍd. T-P removal rate by Amaryllis is average 0.27g/$m^3$ㆍd, T-P removal rate by Reed is average 0.25g/$m^3$ㆍd. BOD removal rate constant with retention time is 1.4494(1/d), T-N removal rate constant is 0.5428(1/d), T-P removal rate constant is 0.5287(1/d).

• 한국식품영양과학회지
• /
• 제43권7호
• /
• pp.1095-1103
• /
• 2014

본 연구에서는 오징어 개별 포장체를 개발하여 포장하지 않은 오징어와 저온 저장에서의 생존율을 비교함으로써 개별포장체를 활용한 유통시스템을 개발하고자 하였다. 개별 포장체를 이용한 활오징어는 저온 저장($10^{\circ}C$, $8^{\circ}C$, $6^{\circ}C$, $4^{\circ}C$, $2^{\circ}C$, $0^{\circ}C$) 조건 하에서 각 10마리씩 저장하였다. $6^{\circ}C$에서 격리 포장된 활오징어는 72시간까지 84%의 우수한 생존율을 나타내었고 이후 생존율이 감소하다 120시간까지 60% 이상의 생존율을 나타내었다. 또한 최대 7일까지 생존하는 것을 관찰하였다. 최적 온도는 $5^{\circ}C$였으며 $5^{\circ}C$에서 96시간 저장했을 때 70% 우수한 생존율을 나타내었고 최대 7일까지 생존이 가능하였다. 냉장트럭을 이용한 유통 실험에서 $5^{\circ}C$ 저온에서 16시간까지 100%의 우수한 생존율을 나타내었고 저장 20시간 이후에도 90% 이상의 우수한 생존율을 보였다. 냉장트럭에 적재할 용기 실험에서는 사각형의 저장용기가 유리하였다. 상자에 공급하는 최소 해수량 실험에서는 20 L 이상의 해수량에서 15시간 이상, 100% 생존하는 것을 확인하였다. 따라서 오징어 한 마리당 2 L의 해수가 필요한 것으로 판단되었다. 냉장트럭 운송 후 보관 수조의 최적 온도는 $5^{\circ}C$였으며 $5^{\circ}C$에서 저장 72시간까지 90% 이상의 생존율을 나타내었고 최대 7일까지 생존이 가능하였다. 따라서 본 연구 결과, 활오징어의 유통 시 개별 포장체를 사용하여 사각용기에 2 L의 해수를 같이 담아 $5^{\circ}C$의 냉장트럭으로 유통하는 것이 가장 바람직한 것으로 나타났다.

• Journal of Korean Dental Science
• /
• 제14권2호
• /
• pp.61-68
• /
• 2021

Purpose: The aim of this study was to investigate the outcomes of endodontic treatment of mandibular second molar with C-shaped canal in elderly patients and related factors affecting the survival of the tooth. Materials and Methods: From 2010 to 2015, the survival rate following endodontic treatment was evaluated in elderly patients over 60 years who visited the Veterans Health Service Medical Center for endodontic treatment. The presence of C-shaped canals was confirmed using clinical records and radiographic features. Patient's age, sex, systemic diseases, tooth location, vitality, signs and symptoms, fractures, caries, apical radiolucency, canal shaping methods, sealer leakage, filling voids, and restoration of prosthesis were included in the analyses as confounding variables. The survival rate of teeth was analyzed using Kaplan-Meire analysis and the relationship between the survival rate and variables was analyzed using Simple and Multiple Cox regression analysis. Result: In total, 107 teeth in elderly patients had C-shaped canal. The survival rate of teeth that received endodontic treatment was 63.70%. None of the factors investigated significantly influenced the survival rate (P>0.05). Conclusion: In elderly patients with C-shaped canal, the survival rate after root canal treatment was not significantly different from that of other mandibular molars.

• 한국세라믹학회지
• /
• 제26권4호
• /
• pp.514-520
• /
• 1989

The early hydration characteristics according to the C3S/C3A ratio and presence of gypsum, in order to establish the hydration mechanism of the system C3S-C3A, have been studied. The rate of C3S dissolution in the system C3S-Gypsum was higher than that in the system C3S. Consequently, the induction period was reduced and the rate of Ca(OH)2 formation in the accleration period was increased. The hydration of C3S in the system C3S-C3A was retarded because Al3+ in the liquid phase originating from the hydration of C3A was incorporated into calcium hydrosilicates formed. The retardation phenomenon of C3S hydration was not appeared in the system C3S-C3A-gypsum because the reaction of monosulfate formation became the rate-determining step.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2011년도 전력전자학술대회
• /
• pp.58-59
• /
• 2011

본 논문은 전류에 따른 NiMH 배터리의 성능 변화를 충 방전 실험을 통하여 비교 분석하였다. 따라서 실험을 통하여 NiMH 배터리의 데이터시트에 있는 충 방전 특성곡선과 실제 실험을 통한 충 방전 특성곡선을 비교 분석한다. 또한 충 방전 전류의 크기에 따라 변하는 특성곡선의 차이를 비교 분석한다. 전류 변화에 의한 배터리 분석을 위해 0.2C, 0.5C, 1C, 2C 정전류 충 방전 실험과 동일한 C-rate로 펄스전류로 충 방전 실험을 하였다. 실험을 통해서 얻은 데이터로 1차 Randles 등가회로를 통해 C-rate변화와 잔존용량 변화에 의한 파라미터 분석과 잔존용량-개로전압 곡선에서의 충 방전 히스테리시스를 알아보았다.

• 원예과학기술지
• /
• 제34권5호
• /
• pp.719-726
• /
• 2016

본 연구에서는 고온 및 저온의 육묘 온도가 파프리카 묘의 소질 및 정식 후 초기 생육에 미치는 영향을 알아보았다. 육묘 온도는 다용되고 있는 $23^{\circ}C$를 대조구로 하여 고온을 $31^{\circ}C$, 저온을 $15^{\circ}C$로 처리하였다. 육묘 온도에 따라 자란 묘의 초장, 줄기직경, 생체중, 건물중, 엽수, 엽면적 등은 $15^{\circ}C$와 $31^{\circ}C$ 처리구에서 대조구보다 유의하게 낮았다. 그리고 그 묘들의 정식 4주 후 식물체 특성에서도 같은 경향을 나타내었다. 대조구 대비 $15^{\circ}C$와 $31^{\circ}C$ 처리구의 단위 시간 당 건물중 및 엽면적의 증가 속도는 육묘 기간보다 정식 후에 크게 높아졌다. 정식 후 4주 간 자란 $15^{\circ}C$와 $31^{\circ}C$ 처리구의 식물체의 작물생장속도와 엽면적지수는 대조구와 유의한 차이를 나타내지 않았고, 상대생장율과 순동화율은 유의하게 높았다. 이러한 $15^{\circ}C$처리구의 정식 후 생장 속도 및 순동화율의 증가는 정식 후 정식 전에 비해 크게 높아진 광합성 능력에서 기인하였다. 이상의 결과를 요약하면, 파프리카의 저온 및 고온 육묘온도는 묘 및 정식 후 식물체의 생육을 저하시켰다. 그리고 정식 후의 식물체의 회복 속도는 $31^{\circ}C$보다 $15^{\circ}C$에서 육묘된 묘에서 빨랐다.

• 한국임상약학회지
• /
• 제6권2호
• /
• pp.14-18
• /
• 1996

This study was attempted to investigate the dissolution rate and the bioavailability after oral administration of commercially available norfloxacin tablets in rabbits. The dissolution test was conducted in artificial gastric juice using basket method with for norfloxacin preparations (A, B, C and D) which were chemically equivalent. The results were as follows ; The dissolution rate was increased in the order of four different brand A>D>B>C. Area under the plasma concentration curve and peak plasma concentration were increased in the order of brand A>D>B>C. Absorption rate constant and peak time were increased in the order of brand B>A>C>D, and there was a little difference in elimination rate constant and biological half-life. The correlation of the dissolution rate and relative bioavailability showed significant linear relationship. From the results of this experiment, the bioavailability of norfloxacin tablets in rabbits may be predicted from the results of dissolution rate studies.