호소수에 대한 막여과 공정 설계 및 운영인자를 도출하기 위하여 부산시 소재 회동 수원지의 물을 원수로 하는 200 m3/일 용량의 정수처리 침지식 막여과 pilot을 운영하였다 (운영기간 : 2018년 1월 ~ 9월). 막여과 공정 운영 관점에서 주요한 원수 수질변화로는 1월 ~ 2월 사이 수온이 5 ℃ 이하를 유지하였고, 6~7월의 평균 탁도는 24±40 NTU 이었으며, 7월 중 태풍 발생으로 인하여 약 229 NTU의 고탁도가 유입되었다. 막여과 pilot 운영결과를 바탕으로 막여과 공정의 주요 설계값인 막여과 유속, 막여과 차압, 약품 세척 주기 및 단위공정의 운전순서를 결정하였다. 운영결과 중에서 특별히 괄목할 만한 관찰점은 막여과 배출수 탁도의 중력침전 제거율이 평균 94±4%로 분석된 것이다.

Presence of a palato-nasally impacted supernumerary tooth with nasopalatine canal involvement is a unique finding that demands careful attention during surgical extraction due to its distinctive anatomy. In this case report of a 7-year-old child, an impacted supernumerary tooth had a developmental anomaly that required both palatal and nasal approaches to successfully remove the tooth.

목적: : 최근 국내에서 다양하게 출시되고 있는 자외선 차단용 기능성 안경렌즈의 자외선 차단율을 동일 굴절률의 기존 안경렌즈와 비교하여 측정하였으며, 이를 국내외 표준규격에서의 자외선 투과율 측정 규정과 비교하여 분석하였다. 방법: 현재 국내에 출시되고 있는 자외선 차단용 기능성 안경렌즈와 굴절률 1.60의 플라스틱 안경렌즈를 분광광도계(spectrophotometer)를 사용하여 자외선 투과율을 측정하고 그 차이를 분석하였다. 결과: 5종류의 1.60 렌즈의 UV-A에 해당하는 320~380 nm까지의 차단율을 측정한 결과, 모든 렌즈가 100%의 차단율을 보였으며, 380~400 nm까지 측정한 결과 평균 98.72%, 320~400 nm에서는 99.2%의 차단율을 나타냈다. 자외선 차단용 기능성 안경렌즈의 320~400 nm에서의 차단율은 100%를 나타내 두 결과값의 차이는 약 0.8%p로 나타났다. 그러나 세계보건기구 산하인 국제비이온화 방사선 방호협회(ICNIRP)는 UV-A의 파장대를 315~400 nm로 규정하고 있지만, 국제 규격인 ISO 8980-3 (Ophthalmic optics- Uncut finished spectacle lenses - Part3: Transmittance specifications and test methods)에서는 UV-A의 파장대를 315~380 nm로 규정하고 있는 것으로 나타났다. 결론: 일반 플라스틱 고굴절률(1.60) 안경렌즈와 자외선 차단용 기능성 안경렌즈는 대기권 내부로 들어오는 UV-A 영역에서 차단율은 크게 차이가 없으며, 국제규격에는 적합한 자외선 차단율을 가진 안경렌즈도 다른 규정으로 인해 부적합한 안경렌즈로 오인될 수 있기에 규격화된 동일 규정에 의한 안경렌즈의 자외선 차단 평가가 필요한 것으로 판단된다.

Algal problem in drinking water treatment is being gradually increased by causing deterioration of water supplies therefore, especially taste and odor compounds such as geosmin and 2-MIB occur mainly aesthetic problem by its unpleasant effects resulting in the subsequent onset of complaints from drinking water consumer. Recently, geosmin and 2-MIB are detected frequently at abnormally high concentration level. However, conventional water treatment without advanced water treatment processes such as adsorption and oxidation process, cannot remove these two compounds efficiently. Moreover, it is known that the advanced treatment processes i.e. adsorption and oxidation have also several limits to the removal of geosmin and 2-MIB. Therefore, the purpose of this study was not only to evaluate full scale nanofiltration membrane system with 300 m3/ day of permeate capacity and 90% of recovery on the removal of geosmin and 2-MIB in spiked natural raw water sources at high feed concentration with a range of approximately 500 to 2,500 ng/L, but also to observe rejection property of the compounds within multi stage NF membrane system. Rejection rate of geosmin and 2-MIB by NF membrane process was 96% that is 4% of passage regardless of the feed water concentration which indicates NF membrane system with an operational values suggested in this research can be employed in drinking water treatment plant to control geosmin and 2-MIB of high concentration. But, according to results of regression analysis in this study it is recommended that feed water concentration of geosmin and 2-MIB would not exceed 220 and 300 ng/L respectively which is not to be perceived in drinking tap water. Also it suggests that the removal rate might be depended on an operating conditions such as feed water characteristics and membrane flux. When each stage of NF membrane system was evaluated relatively higher removal rate was observed at the conditions that is lower flux, higher DOC and TDS, i.e., 2nd stage NF membrane systems, possibly due to an interaction mechanisms between compounds and cake layer on the membrane surfaces.

본 논문은 노후소득보장정책을 중심으로 한국 노인복지정책의 발전방향을 모색하는 데 그 목적이 있다. 이를 위해 본 논문은 우선 한국의 노후소득보장정책의 현황을 살펴보고자 하며, 다음으로 그러한 현황분석을 토대로 향후 한국이 고령사회에 적합한 노후소득보장정책을 갖기 위하여 어떤 노력을 기울여야 하는지 논의하고자 한다. 본 논문은 크게 세 부분으로 구성된다. 첫째, 노인복지정책 중에서도 왜 노후소득보장정책에 주목해야 하는지를 커다란 사회경제적 변화, 예컨대 인구의 고령화 및 복지국가의 변화와 연결지여 살펴본다. 둘째, 한국의 노후소득보장정책이 그런 사회경제적 변화에 잘 부합하고 있는지 그 현황을 되짚어보고, 이를 통해 우리의 현실을 진단한다. 셋째, 현황에 대한 진단과 비판적 검토를 토대로 향후 한국의 노후소득보장정책이 어떤 방향으로 발전해 나가야 하는지 모색한다.

Hydroxyapatite (HAp) and biphasic calcium phosphate (BCP) nano powders were synthesized using the microwave-assisted synthesis process dependent on pH and microwave irradiation time. The average size of a powder was less than 100 nm in diameter. Through in-vitro cytotoxicity tests by an extract dilution method, the HAp and BCP nano powders have shown to be cytocompatible for L-929 fibroblast cells, osteoblastlike MG-63 cells and osteoclast-like Raw 264.7 cells. The activation of osteoblast was estimated by alkaline phosphatase (ALP) activity. When the HAp and BCP were treated to MG-63 cells, alkaline phosphatase activities increased on day 3, compared with those of the untreated cells. Also, the collagen fibers increased when the HAp and BCP powders suspension were treated to MG-63 cells, compared to those of the untreated cells. Quantitative alizarin red S mineralization assays showed a trend toward increasing mineralization in osteoblast cultured with powder suspension. In conclusion, hydroxyapatite and biphasic calcium phosphate appeared to be a bone graft substitute material with optimal biocompatibility and could be further applied to clinical use as an artificial bone graft substitute.

The purpose of this study is to measure the cost-benefit of a road construction project in Vietnam through international development cooperation, which includes private grants and Official Development Assistance(ODA). In developing countries, it is difficult and costly to use data on markets, the CVM(Contingent Valuation Method) to measure the WTP(Willingness-to-Pay) as the benefits of road construction are used. A total of 232 villagers in 16 villages of Lao Cai Province in Northern Vietnam have been surveyed. It is found that the Benefit-Cost Ratio(B/C) in all 3 models are found to be well over 1.0, ranging from 2.8 to 3.64 with the discount rate of 0.06. These BC ratios imply the road construction project in Lao Cai can be justified. Also, it is found that the shortened travel time is the most relevant factor for WTP among direct benefits and the enhanced academic achievement of the children is the most relevant factor among indirect benefits, due to easier and faster access to schools, which in turn increase the school attendance rate. The result of this study can be used to justify other similar projects in Vietnam, even though the benefits may have to be reassessed in other countries.

The aim of this study is to investigate the effects of tea catechin on fasting blood glucose in experimental diabetes model. Type 2 diabetes mellitus in rats was induced by high fat diet/low-dose streptozotocin. The experimental group was divided into 3 different groups, non-diabetes control (NC) group, diabetes mellitus (DM) group, and diabetes mellitus+P60 (DM+P60) group. Polyphenon 60(P60) administered with dissolved in 0.2% dringking water. At 16 weeks after P60 treatment, fasting blood glucose, plasma insulin and serum triglyceride levels were measured. The glucose metabolism-related genes were studied in rat liver by RNA-seq analysis. Fasting blood glucose levels increase by four times in the DM group compared to the NC group. In the DM+P60 group, it was decreased by 24% compared to the DM group. The HOMA-IR index was increased in the DM group and it decreased in the DM+P60 group compared to the DM group. The serum triglyceride level increased by 148% in the NC group, and decreased by 22% in the DM+P60 group compared to the DM group. Glucokinase mRNA expression was decreased in the liver of DM group compared to NC group, whereas the phosphofructokinase 1, glucose-6-phosphotase and phosphoenolpyruvate carboxykinase expression did not show significant differences in DM group liver. In DM+P60 group, liver glucokinase expression was increased significantly (P: 5.00E-05) compared with DM group. This study shows that P60 beneficially modifies glucose metabolism and markedly enhances glucose tolerance in experimental diabetic rats. Dietary supplementation with P60 could potentially contribute to nutritional strategies for treatment of type 2 diabetes mellitus.