• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.452-455
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• 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$(2{\theta}=41.5^{\circ})$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.533-536
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• 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

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.30-34
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• 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($2{\theta}=41.5^{\circ}$).

• Journal of Environmental Science International
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• v.8 no.1
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• pp.75-81
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• 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).

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1095-1103
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• 2014

A packaging and distribution system for transferring individual live squids at low temperature was developed and compared to a conventional bulk container system. Ten live squids in individual packages were stored in a large container at low temperature ($0{\sim}10^{\circ}C$). Live squids in individual packages at $6^{\circ}C$ showed a survival rate of 84% up to 72 hours, after which the survival rate decreased. However, the survival rate remained at 60% up to 120 hours. Further, the squids survived up to a maximum of 7 days. Optimum temperature was $5^{\circ}C$, and the survival rate of the packages was 70% when stored at $5^{\circ}C$ for 96 hours. A distribution test was carried out using a refrigerator truck at $5^{\circ}C$, and the results showed a 100% survival rate up to 16 hours and over 90% survival rate after 20 hours. A rectangular container was the most favorable when loading the container into the refrigerator truck. In testing the required volume of supplied seawater, 100% survival rate was observed over 15 hours with 20 L of sea water or more. Therefore, a single squid needed 2 L of seawater. After refrigerator truck transportation, optimum temperature for fish tank storage was $5^{\circ}C$, at which the survival rate was over 90% up to 72 hours. Using a refrigerator truck at $5^{\circ}C$, live squids survived up to 7 days, maintaining marketability.

• Journal of Korean Dental Science
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• v.14 no.2
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• pp.61-68
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• 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.

• Journal of the Korean Ceramic Society
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• v.26 no.4
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• pp.514-520
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• 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.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.58-59
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• 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.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.719-726
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• 2016

The effect of high and low temperatures on seedling quality while raising of paprika (Capsicum annuum L.) seedlings, and their early development after planting was investigated. The control raising seedling temperature (RST) was $23^{\circ}C$; high temperature, $31^{\circ}C$; and low temperature, $15^{\circ}C$ throughout the raising seedling period. At $15^{\circ}C$ and $30^{\circ}C$, plant height, stem diameter, fresh weight, dry weight, number of leaves, and seedling leaf area were significantly lower than those at $23^{\circ}C$. At 4 weeks after planting, seedling's growth characteristics showed a similar pattern. Compared to $23^{\circ}C$, seedlings raised at $15^{\circ}C$ and $30^{\circ}C$ had an increased dry weight and leaf area per unit time after planting than during the seedling raising period. At 4 weeks after planting, crop growth rate and leaf area index were unaffected by RST, and relative growth rate and net assimilation rate at RSTs of $15^{\circ}C$ and $31^{\circ}C$ were higher than those those at RST of $23^{\circ}C$. At an RST of $15^{\circ}C$, growth speed and net assimilation rates were higher after planting than before planting, according to increased photosynthetic rate. Thus, high and low temperatures during the seedling raising period significantly reduced seedling growth and plant growth after planting. After planting, seedlings raised at $15^{\circ}C$ recovered more quickly than did those raised at $31^{\circ}C$.

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.14-18
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• 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.