This study was performed to evaluate the pollutants removal characteristics of two types of RBFs(Riverbank filtration, Riverbed filtration) intake facilities installed in Nakdong River and in Hwang River respectively. The capacity of each RBF is 45,000 ㎥/d for riverbank filtration intake facility and 3,500 ㎥/d for riverbed filtration intake facility. According to data collected in the riverbank filtration site, removal rate of each pollutant was about BOD(Biochemical oxygen demand) 52%, TOC(Total organic carbon) 57%, SS(Suspended solids) 44%, Total coliforms 99% correspondingly. Furthermore, Microcystins(-LR,-YR,-RR) were not found in riverbank filtered water compared to surface water in Nakdong River. DOC(Dissolved organic carbon) and Humics which are precursors of disinfection byproduct were also reported to be removed about 59% for DOC, 65% for Humics. Based on data analysis in riverbed filtration site in Hwang River, removal rate of each contaminant reaches to BOD 33.3%, TOC 38.5%, SS 38.9%, DOC 22.2%, UV254 21.2%, Total coliforms 73.8% respectively. Additionally, microplastics were also inspected that there was no obvious removal rate in riverbed filtered water compared to surface water in Hwang River.

Li1.3Al0.3Ti1.7(PO4)3(LATP) is considered a promising material for all-solid-state lithium batteries owing to its high moisture stability, wide potential window (~6 V), and relatively high ion conductivity (10-3–10-4 S/cm). Solid electrolytes based on LATP are manufactured via sintering, using LATP powder as the starting material. The properties of the starting materials depend on the synthesis conditions, which affect the microstructure and ionic conductivity of the solid electrolytes. In this study, we synthesize the LATP powder using sol-gel and co-precipitation methods and characterize the physical properties of powder, such as size, shape, and crystallinity. In addition, we have prepared a disc-shaped LATP solid electrolyte using LATP powder as the starting material. In addition, X-ray diffraction, scanning electron microscopy, and electrochemical impedance spectroscopic measurements are conducted to analyze the grain size, microstructures, and ion conduction properties. These results indicate that the synthesis conditions of the powder are a crucial factor in creating microstructures and affecting the conduction properties of lithium ions in solid electrolytes.

PURPOSES : When fire event occurs in tunnel the reinforced concrete is exposed to very high temperature at a very short time period. This study investigates the tensile behavior of steel rebar that experienced high temperature. METHODS : The steel rebar was exposed to 200, 400, 600, and 800℃ following the ISO 834 temperature-time fire curve. Hightemperature- exposed steel rebars were tested using the UTM for their yielding and tensile strengths, and elongation rate. RESULTS : Up to an exposure temperature of 600℃, the tensile properties of the rebar did not vary considerably. However, at 800℃ (which corresponds to a temperature rise time of approximately 22 min), the rebar lost its yielding and tensile strength by approximately 27 and 13%, respectively, compared to the control specimen. Further, the elongation rate increased after exposure to 600℃. The above fundamental tensile test results can be a good reference for future guidelines in the repair manual for tunnels after severe fire events. CONCLUSIONS : When steel rebar experiences high temperatures of 800℃, the yield strength of the rebar reduces approximately 27%. This strength reduction can cause severe structural damage to tunnels that use reinforced concrete as the primary structural elements.

Carbon fibers (CFs) are considered promising composite materials for various applications. However, the high cost of CFs (as much as $26 per kg) limits their practical use in the automobile and energy industries. In this study, we developed a continuous stabilization process for manufacturing low-cost CFs. We employed a textile-grade polyacrylonitrile (PAN) fiber as a low-cost precursor and UV irradiation technique to shorten the thermal stabilization time. We confirmed that UV irradiation on the textile-grade PAN fibers could lower the initial thermal stabilization temperature and also lead to a higher reaction. These resulted in a shorter overall stabilization time and enhancement of the tensile properties of textilegrade PAN-based CFs. Our study found that only 70 min of stabilization time with UV irradiation was required to prepare textile-grade PAN-based low-cost CFs with a tensile strength of 2.37 ± 0.22GPa and tensile modulus of 249 ± 5 GPa.

In this study, multilayered SnO nanoparticles are prepared using oleylamine as a surfactant at 165oC. The physical and chemical properties of the multilayered SnO nanoparticles are determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Interestingly, when the multilayered SnO nanoparticles are heated at 400oC under argon for 2 h, they become more efficient anode materials, maintaining their morphology. Heat treatment of the multilayered SnO nanoparticles results in enhanced discharge capacities of up to 584 mAh/g in 70 cycles and cycle stability. These materials exhibit better coulombic efficiencies. Therefore, we believe that the heat treatment of multilayered SnO nanoparticles is a suitable approach to enable their application as anode materials for lithium-ion batteries.

본 연구는 서울·경기 소재 65세 이상 노인 463명을 대상으로 신체활동 참여에 따른 체력요 인과 인지기능, 일상생활수행능력, 도구적 일상생활수행능력 및 심리적 변인에 대한 차이를 분석하였다. 수집 된 자료는 SPSS 25.0 통계프로그램을 이용하여 빈도분석, 신뢰도 분석, 독립 t-검증과 일원분산분 석 그리고 피어슨의 상관관계분석을 실시하였으며 모든 통계적 유의수준은 p<.05로 설정하였다. 그 결과 첫째, 노인의 신체활동 참여유무에 따라 체력, 인지기능, 일상생활수행능력, 도구적일상생활수행능력 및 심리적 변인인 우울과 삶의 질에 통계적으로 유의한 차이가 나타났으며, 신체활동에 참여하는 노인의 참여빈도에 따라 체력, 인지기능, ADL, IADL, 우울 및 삶의 질에 통계적 유의한 차이가 나타났다. 신체활동에 참여하는 노인의 참여시간에 따라 체력에서 통계적 유의한 차이가 나타났다. 둘째, 체력과 인지기능, ADL, IADL, 우울 및 삶의 질의 상관관계를 살펴본 결과 대부분의 요인에서 상관관계가 나타났다. 이러한 연구결과를 바탕으로 노인의 성공적인 노화와 자립적인 노후생활을 위해 신체활동을 포함한 체계적인 중재 전략의 개발이 필요하다.

국내 하천에서 발생하는 준설 및 보 건설은 하천 연속성 차단과 교란을 유도하여 수서 생물서식환경에 변화를 가져 온다. 본 연구에서는 4대강 보 (이포보, IP; 세종보, SJ; 죽산보, JS; 강정고령보, GG; 달성보, DS)에 서식하는 깔따구 군집 분포를 조사하고 서식환경에 영향을 주는 여러 환경인자를 측정하였다. 조사 지역 중 IP, SJ은 다른 조사 지역에 비해 WT, pH, TOC, Chl-a가 낮은 수준을 보였으며, 깔따구 개체수 결과에서는 Chironominae, Orthocladinae, Tanypodinae 가 비교적 균등한 수준으로 관찰되었다. 반면, JS, GG, DS는 Chironominae가 높은 비율로 우점하며, TOC와 Chl-a의 농도가 높게 나타났다. 각 조사 정점에 대한 깔따구 군집 조성의 특징과 환경요인을 반영한 집괴분석 결과 4대강 보는 3개의 그룹으로 구분되었으며, 이는 정점별 환경 차이와 깔따구의 대악 및 하순기절의 구조에 따른 먹이원 선호도 차이와 일치하였다. 따라서 본 연구에서는 연구 정점 간 먹이원의 차이에 의해 깔따구의 군집 구조의 차이가 나타나는 것을 확인 하였으며, 향후 각 깔따구 과 별 주 먹이원에 대한 연구에 대한 필요성을 제시한다.

Myelolipoma is a benign tumor consists of mature adipocyte and hematopoietic elements. Mostly, this tumor locates in adrenal gland and it also can be found in extra-adrenal area. However, intraosseous myelolipoma is extremely rare. The etiology of this tumor is unclear but some hypothesis proposed that altered mesenchymal stem cell functioning and hormonal events act together in the pathogenesis of myelolipoma. With radiographic view, myelolipoma shows similar characteristics of other fat-containing tumors. The histopathologic examination is necessary for the definite diagnosis. This case report includes a patient with intraosseous myelolipoma of maxilla and mandible and literature review about the clinical, histopathologic, and radiologic features of myelolipoma.

This study includes the clinical features of diabetic patients with fascial space infections of head and neck and those of non-diabetic patients. We retrospectively studied 62 patients who were treated for fascial space infections of the head and neck, and compared the patients’ background, the aetiology of the infection, clinical variables, laboratory values, and treatment process. Statistical analyses of the differences between groups were made with Student's t test, the chi square test, and analysis of variance, as appropriate. Diabetic patients had more spaces involved, had longer hospital stays, and developed more complications. The main microorganism of diabetic group was Klebsiella pneumonia and otherwise, Streptococcus spp. was for non-diabetic group. We conclude that diabetic patients are more likely to develop complications and it is necessary to consider about dominant microorganism when using medication for diabetes patients