In this study, an Co/Fe coated porcelain using a cobalt and ferrous sulfate was sintered at 1,250 oC. The specimens were investigated by HR-XRD, FE-SEM (EDS), Dilatometer, and UV-vis spectrophotometer. The surface of the porcelain was uniformly fused with the pigment, and white ware and celadon body specimens were densely fused to a certain thickness from the surface. Other new compounds were produced by the chemical reaction of cobalt/ferrous sulfate with the porcelain body during the sintering process. These compounds were identified as cobalt ferrite spinel phases for white ware and white mixed ware, and an andradite phase for the celadon body, and the amorphous phase, respectively. As for the color of the specimens coated with cobalt and ferrous mixed pigments, it was found that the L* value was greatly affected by the white ware, and the a* and b* values were significantly changed in the celadon body. The L* values of the specimens fired with pure white ware, celadon body, and white mix ware were 72.1, 60.92, 82.34, respectively. The C7F3 pigment coated porcelain fired at 1,250 oC had L* values of 39.91, 50.17, and 40.53 for the white ware, celadon body, and white mixed ware, respectively; with a* values of -1.07, -2.04, and -0.19, and at b* values of 0.46 and 6.01, it was found to be 4.03. As a new cobalt ferrite spinel phase was formed, it seemed to have had a great influence on the color change of the ceramic surface.
This study investigated the reaction between clay and Mn. Mn was coated using a manganese sulfate on porcelain plate and sintered from 1,100 oC to 1,250 oC. The body begin to shrink around 950 oC with the increase in temperature and rapidly progressed after 1,100 oC. Shrinkage of celadon body was performed at a lower temperature than for other substrates. Quartz, kaolin, and feldspar were the main crystalline phases of the starting materials, but they became mullite and crystobalite during the firing process, and some formed amorphous glass. When manganese sulfate was applied and fired, manganese oxide was fused, and some manganese oxide reacted with the substrate to show a dense microstructure different from that of the substrate; the substrate had pores. The manganese coated porcelain fired at 1,200 oC had L* values of 55.25, 36.87, and 37.13 for the white ware, celadon body, and white mixed ware, respectively; with a* values of 4.63, 3.07, and 2.15, and b* values of 7.93 and 3.98, it was found to be 3.42. This result indicated that the color of the surface was affected during firing by the chemical reaction between the substrate and manganese.
본 연구는 간호대학생의 그릿과 사회적 지지가 대학생활적응에 미치는 영향요인을 파악하기 위한 조사연구이다. 연구 대상자는 간호대학생 196명을 대상으로 하였으며 자료수집은 2020년 7월 1일부터 8월 13일까지 수행하였다. 자료 분석은 SPSS 22.0을 이용하여 기술통계, 상관관계 분석 및 다중회귀분석을 사용하였다. 연구결과, 간호대학생의 대학생활적응은 그릿(r=.328, p<.001)과 사회적 지지(r=.334, p<.001) 와 유의한 정적 상관관계를 보였다. 학년, 그릿 및 사회적 지지는 간호대학생의 대학생활적응에 유의한 영향을 미치는 요인으로 나타났다. 이에 본 연구결과를 바탕으로 간호대학생의 대학 생활 적응을 위해서 그릿과 사회적 지지와 같은 긍정적 요인을 포함시킨 대학생활적응 프로그램 개발 및 적용을 제안한다.
서울시내에 위치한 프랜차이즈 매장과 대형마트 내 판매되고 있는 4종(후라이드, 양념, 간장, 치즈가루 치킨)의 치킨제품 123건에 대하여 당과 나트륨 검사를 실시하였다. 전체 치킨제품의 평균 당 함량은 100 g 당 4.5 g이었으며, 양념치킨(8.7 g), 치즈가루 치킨(4.3 g), 간장치킨(3.6 g), 후라이드 치킨(0.6 g) 순으로 나타났다. 평균 나트륨 함량은 전체 치킨제품의 경우 100 g 당 552.4 mg이었으며, 치즈가루 치킨(627.0 mg), 간장치킨(536.3 mg), 양념치킨(511.2 mg), 후라이드 치킨(448.0 mg) 순으로 나타났다. 프랜차이즈와 대형마트 내 판매 치킨제품을 비교하였을 때, 평균 당 함량의 경우 100 g당 대형마트 내 판매 후라이드 치킨(0.8 g) 과 양념치킨(8.9 g)에서 모두 프랜차이즈의 후라이드 치킨 (0.5 g)과 양념치킨(8.6 g)보다 높았으며, 프랜차이즈와 대형 마트 내 판매 제품에 따른 유의적으로 차이를 보였다(P<0.05). 평균 나트륨 함량의 경우 100 g당 프랜차이즈 양념치킨 (516.0 mg)과 대형마트의 후라이드 치킨(471.5 mg)이 높은 값을 보였으며, 유의적인 차이는 보이지 않았다. 포장량 전체를 섭취했을 경우, 평균 당 함량의 섭취비율은 후라이드 치킨은 모두 WHO에서 권고하는 1일 당류 섭취권고량인 50 g 이하였고, 간장치킨(47.6%)과 치즈가루 치킨(55.4%)은 절반 수준이었으나, 양념치킨은 프랜차이즈(140.4%)와 대형마트(148.8%) 제품 모두 권고량을 넘어섰다. 나트륨은 WHO의 1일 나트륨 섭취권고량인 2,000 mg 대비 섭취비율이 후라이드 치킨은 프랜차이즈(140.1%)와 대형마트(170.3%) 제품과 간장치킨(167.9%)에서 높게 나타났다. 특히, 양념치 킨은 프랜차이즈(203.7%)와 대형마트(208.4%) 제품 모두와 치즈가루 치킨(202.4%)에서 섭취권고량의 2배를 넘어선 것으로 나타났다.
In this research, the inspection system for the concentricity of hole-saws through the image analysis is developed. The hole-saw, made by being rolled manually with bimetals, is the tool to make a hole in the wall. Its quality is definitely depended on the concentricity of hole-saws. However, it is difficult to check its concentricity and make a decision for the quality control without any automatic inspection system. This research made the automatic image analysis program based on the singular value decomposition model with only a webcam. Experimental results and evaluations demonstrate the validity of the proposed methods.
A microfluidic reactor with computer-controlled programmable isocratic pumps and online detectors is employed as a combinatorial synthesis system to synthesize and analyze materials for fabricating CdSe quantum dots for various applications. Four reaction condition parameters, namely, the reaction temperature, reaction time, Cd/Se compositional ratio, and precursor concentration, are combined in synthesis condition sets, and the size of the synthesized CdSe quantum dots is determined for each condition. The average time corresponding to each reaction condition for obtaining the ultraviolet–visible absorbance and photoluminescence spectra is approximately 10 min. Using the data from the combinatorial synthesis system, the effects of the reaction conditions on the synthesized CdSe quantum dots are determined. Further, the data is used to determine the relationships between the reaction conditions and the CdSe particle size. This method should aid in determining and selecting the optimal conditions for synthesizing nanoparticles for diverse applications.
내시경 역행 췌담관조영술 중 경췌중격절개술은 선택적 담관 삽관이 어려운 환자에서 성공률을 높일 수 있는 방법으로 알려져 있다. 최근 후향적 연구에서는 경췌중격절개술이 침형절개도를 이용한 조임근절개술보다 효과적이며 안전한 것으로 보고되었다. 그러나 이번 증례에서 담석췌장염 환자에서 경췌중격절개술 후 벽내 십이지장 혈종 및 십이지장 폐쇄가 발생하였고 이로 인해 저혈량쇼크 등 치명적인 합병증이 발생하였다. 따라서 급성 췌장염이 동반된 환자에서 내시 경역행췌담관조영술 중 경췌 중격절개술을 시행한 후에는 벽내 십이지장 혈종과 같은 합병증 발생 여부를 주의 깊게 관찰할 필요가 있다고 생각된다.
In everyday network changing field, permanent service is being an issue. Network disconnection phenomenon is directed to financial damage to service providers. Some companies guarantee on network maintenance, but there is a permitted limit according to their company regulations. If customers overuse the limitation, extra pay will be placed. Moreover, network disconnection affects critical in some fields with using network. Permanent service becomes indispensable in stock, finance, online game, and other fields. Additionally, it should be possible to pre-detect and block abnormal traffic area, improve network infrastructure secureness and optimization, and reduce damage recovery cost. MCS(Multi Connection System) can provide permanent service even if a connection is cut because it provides multi-connection. It can also isolate the attacker when it detects DDoS attack, so it provides smooth service. Also, the benefit from this structure is that the real server can be hidden so the service can be provided continuously. It prevents damages from network cutting, reduces management cost, maintains the best performance, and increases convenient on management and maintenance. Stable and continuous service can be provided with managing network through MCS.
This study was investigated to determine the contents of sulfur dioxide residues in medicinal herbs in Seoul Yang Nyoung Shi in 2010 (1,522 samples of 189 kinds). Samples were measured by modified Monier-Williams method. Of the total samples, 618 samples (84 kinds) were domestic, and 904 samples (158 kinds) were imported. The content of sulfur dioxide in the domestics showed the range of 0.0 to 1,298.0 mg/kg (average 12.7 mg/kg), while those in imported samples were the range of 0.0 to 3,982.2 mg/kg (average 42.4 mg/kg). The average (mg/kg) amount of sulfur dioxide by parts in medicinal herbs was as follows; Tuber 122.3, Radix 69.3, Rhizoma 37.4, Cortex 33.3, Fructus 8.8, Ramulus 4.9, Semen 4.6, Folium 3.4, Flos 2.7, Perithecium 1.4. Of the total samples (1,522), 52 samples (3.4%) were violated the KFDA regulatory guidance of sulfur dioxide. Among these 52 unsuitable samples, 16samples (7 kinds) were domestic, and 36 samples (23 kinds) were imported. Approximately 88.1% of the total samples was less than 10 mg/kg of sulfur dioxide and 6.3% of the total samples showed more than 30 mg/kg of sulfur dioxide.
The increase in the consumption of herb medicines have made their use a public health problem due to the potential fungal contamination and the risk of the presence of mycotoxins. 360 samples of herb medicines were evaluated for the aflatoxin contamination. The natural occurrence of aflatoxins in these samples were determined using immunoaffinity column clean up and high performance liquid chromatography (HPLC) with post-column derivatization. For samples analyzed, mean levels (incidence) of AFB1, AFB2, AFG1 and AFG2 in positive samples were 1.4 μg/kg (46.4%), 0.4 μg/kg (25.4%), 1.1 μg/kg (37.8%) and 0.9 μg/kg (24.3%), respectively. Recoveries of the full analytical procedure were 71.7~99.7% for AFB1, 88.1~99.2% for AFB2, 82.8~95.5% for AFG1 and 77.9~90.0%for AFG2. The excess cancer risk estimated using the cancer potency of aflatoxin B1 (7 (mg/kg/day)−1 for HBsAg− and 230 (mg/kg/day)−1 for HBsAg+) were 1.30 × 10^(−5) ~ 1.22 × 10^(−7) for hepatits B surface antigen negative (HBsAg−) and 3.31 × 10^(−4)~ 3.12 × 10^(−6) for hepatits B surface antigen positive (HBsAg+) respectively. In conclusion, although the contamination levels of samples used in the study were low, further actions are also required to undertake a program of herbal surveys in order to access mycotoxin contamination overall so that the safety of public will be protected.
본 논문의 1편에서는 레저선박의 실시간 선체구조모니터링시스템을 개발하기 위하여 도파로 어레이격자(AWG, Arrayed Waveguide Grating)와 광섬유 브래그격자센서(FBG, Fiber-optic Bragg Grating)를 이용한 선체구조모니터링시스템의 설계 및 적용 가능성을 검토하였다. 본 연구에서는 레저선박의 구조취약부의 실시간 모니터링을 위하여 광섬유센서 데이터의 측정 및 분석을 고속으로 처리할 수 있도록 시스템을 최적화하였으며, 레저선박의 선체구조안전모니터링을 위하여 레저선박의 선체 주재료인 FRP와 알루미늄 시편을 대상으로 재료 특성에 대한 기 초 데이터베이스를 구축하였다. 30feet 및 60feet급 세일요트의 알루미늄 마스트에 개발된 시스템을 적용하여 하중변화에 따른 변형률 특성 확인 및 레저선박의 선체구조안전성 평가를 위한 기초 연구를 수행하였다.
21종류의 폴리스티렌 용기를 대상으로 용출조건에 따른 용기내 증류수로 용출되는 5종의 VOCs(톨루엔, 스티렌, 에틸벤젠, 이소프로필벤젠 및 n-프로필벤젠)를 Purge&Trap 장치를 연결하여GC-FID로 분석하였다. 각 표준물질은 1~50 ng/ mL의 농도범위에서 직선성(r2 =0.9976~0.9995)을 나타냈으며, 검출한계는 0.041~0.092 ng/mL, 정량한계는 0.135~0.304 ng/mL 이었다. 용출조건은 첫째, 60oC에서 30분, 둘째, 95oC에서 30분, 셋째, 실생활에서 컵라면 섭취시를 고려하여 끓은 물을 부은 후 뚜껑을 덮고 3분간 유지한 다음 뚜껑을 열고 5분 동안 개방하여 용출시키는 것으로 설정하였다. 톨루엔, 에틸벤젠, 이소프로필벤젠 및 n-프로필벤젠은 평균용출량이 모든 조건에서 5 ng/mL 이하로 검출되었으며 스티렌의 경우는 60oC에서 평균용출량이 4.02 ng/mL, 95oC에서는 52.71 ng/mL, 컵라면 섭취시의 조건에서는 17.23 ng/mL로 검출되었다.
Disk type porous nickel membrane was fabricated by in-situ reduction/sintering process using compacted NiO/PMMA (PMMA; Polymethyl methacrylate) mixture at 800℃ in hydrogen atmosphere. The porosity (4958%) of these membrane was investigated as an amount of PMMA additive. The thermal decomposition and reduction behavior of NiO/PMMA were analyzed by TG/DTA in hydrogen atmosphere and the activation energy for the hydrogen reduction of NiO and thermal degradation of PMMA was calculated as 61.1 kJ/mol, evaluated by Kissinger method. Finally, the filtering performance and pressure drop were measured by particle counting system.
Through the volume change of Sn in a low-temperature phase transformation, the Sn nanopowder with high, purity, was fabricated by an economic and eco-friendly process. The fine cracks were spontaneously generated. in, Sn ingot, which was reduced to powders in the repetition of phase transformation. The Sn nanopowder with 50 run in size was obtained by the 24th repetitions of phase transformation by low-temperature and ultrasonic treatments. Also, the powder was fabricated by the oxidation of the produced Sn powder to the ingot and milled by the ultrasonic milling method. The nanopowder of 20 nm in size was fabricated after the milling for 180 h