최근에는 익명성과 비대면성으로 인해 사이버 공간에서 괴롭힘의 가능성이 높다. 사이버 공간은 현실적 공간 과 비교했을 때 24시간 괴롭힘이 가능하고, 괴롭힘을 매우 빠르고 광범위하게 확산시킨다. 사이버 공간에서의 괴롭힘은 물리적 공간에서의 괴롭힘보다 더 심각한 정신적 피해를 줄 수 있다. 본 연구는 청소년의 사이버 괴 롭힘 경험과 자살생각에 대하여 살펴보았다. 사이버 괴롭힘 경험을 따돌림, 욕설과 모욕 중심으로 살펴보고, 사이버 괴롭힘의 정도에 따라 자살사고의 차이를 살펴보았다. 자료는 한국청소년정책연구원의 2019 중고등용 인권실태조사 데이터를 활용하였다. 집단 간의 차이를 검증하기 위해 SPSS프로그램 25를 사용하여 공분산분 석(ANCOVA)을 실시하였다. 종속변수에 영향을 줄 수 있는 현실공간인 학교에서의 괴롭힘 경험을 통제하여 청소년이 사이버공간에서 괴롭힘 경험에 따른 자살생각의 차이를 검증하였다.

The electrical resistances of small-sized activated carbon fiber (ACF) fabric (specific surface area: 1244.7 m2/ g, average pore diameter: 1.92 nm) and felt (specific surface area: 1321.2 m2/ g, average pore diameter: 2.21 nm) sensors were measured in a temperature and humidity controlled gas chamber by CO2 adsorption at different surrounding CO2 concentrations (3000–10,000 ppm). The electrical resistances of ACF sensors decreased linearly as the increase of temperature and decreased exponentially as the increase of humidity in the ambient atmospheric chamber. The electrical resistances of ACF rapidly decreased within 4 s and an equilibrium state was achieved within 10 s due to the very rapid CO2 adsorption at room temperature and 40% humidity. Comparing the difference in electrical resistance values measured during injection of similar concentrations of CO2 after reaching the equilibrium value, the fabric exhibited a significant change, whereas the felt did not, even though it had a relatively larger specific surface area. The reason is that micropore volume greatly affected the amount of CO2 adsorbed, whereas the specific surface area did not affect it as much. Therefore, ACF fabric with large micropores (> 2.0 nm) can be developed and used as CO2 sensors in small rooms such as a passenger vehicles.

목적 : 본 연구는 3-[{2-(Methacryloyloxy)ethyl}dimethylammonio]propane-1-sulfonate(DMAPS)로 기능화된 하이드로겔 콘택트렌즈를 개발하고, 이들의 물리적 물성과 단백질 및 세균의 흡착성을 조사하기 위한 것이다. 방법 : 하이드로겔 콘택트렌즈는 2-hydroxyethyl methacrylate(HEMA)와 ethylene glycol dimethacrylate (EGDMA)의 공중합에 의해 제조되었다. 연속적으로 벤조페논의 흡착과 DMAPS 단량체의 UV 유도 자유 라디칼 중합을 통해 양쪽 이온성이 기능화된 하이드로겔 콘택트렌즈를 제조하였다. 제조된 콘택트렌즈의 수분함량, 접촉각, 광학적 특성, 단백질 및 세균 흡착을 분석하였다. 결과 : DMAPS으로 기능화된 하이드로겔 콘택트렌즈는 더 높은 수분 함량, 향상된 표면 습윤성 및 우수한 가시광선 투과율을 가지고 있다. 더욱이, 하이드로겔 콘택트렌즈 표면에 양쪽 이온성의 DMAPS가 존재하기 때문에 라이소자임 및 알부민과 같은 단백질의 흡착이 낮아지고 세균 흡착이 대군에 비해 감소하였다. 결론 : 양쪽 이온성의 DMAPS을 이용한 하이드로겔 콘택트렌즈의 기능화 방법은 습윤성이 우수하고 단백질 및 세균 흡착을 감소시킬 수 있는 기능성 콘택트렌즈의 개발을 위한 전략을 제공할 수 있다.

The present multidisciplinary study, which is a nexus of engineering and political science, investigates how the modernization of Non-Strategic Nuclear Weapons (NSNWs) affects the IAEA safeguards system based on the likelihood of the use of nuclear weapons. To this end, this study examines the characteristics of modernized NSNWs using Monte Carlo techniques. The results thus obtained show that 10 kt NSNWs with a Circular Error Probability (CEP) of 10 m can destroy the target as effectively as a 500 kt weapon with a CEP of 100 m. The IAEA safeguards system shows that the Significant Quantity (SQ) of 1 of plutonium is 8 kg, a parameter that was established when strategic nuclear weapons were dominant. However, the results of this study indicate that in recent years, low-yield nuclear weapons such as NSNWs have been more strategically interesting than strategic nuclear weapons as NSNWs require less plutonium than strategic nuclear weapons. Therefore, we would like to conclude that reducing the SQ of plutonium can result in more robust safeguards and non-proliferation strategies.

The concentrations of four potentially toxic elements were analyzed in 70 spraint samples of Eurasian otters from the Daechung Lake area. The median concentrations of As, Hg, Ni, and Pb were 1.19, 1.06, 9.95, and 0.37 μg/g dry weight, respectively. A moderate negative correlation was observed between the levels of Hg and Pb (rs = -0.47). The Hg levels showed a weak negative correlation with the distances of the sampling locations from the Daechung Dam (rs = -0.35). This study provides baseline information on the health risks associated with the hazardous elements in otter species.

Understanding the distribution of heavy metals in sediment is necessary because labile heavy metals can partition into the water column and bioaccumulate in aquatic organisms. Here we investigated six heavy metals (Co, Cu, Mn, Ni, Pb, and Zn) in sediment cores using a five-step sequential leaching method to examine the occurrence of heavy metals in the sediment. The results showed that all elements, except Mn, are depleted in the exchangeable and carbonate fractions. However, heavy metal concentrations are much higher in the Fe-Mn oxide and organic matter fractions, especially for Cu, indicating enrichment in the organic matter fraction. Furthermore, contamination parameters (contamination factor and geoaccumulation index) indicate that Mn contamination is high, primarily derived from anthropogenic sources, presenting a potential risk to ecosystems in the Nakdong River.

This study aimed to investigate the effects of oyster mushroom addition on the physicochemical properties of full fat soy (FFS)-based extruded meat analog. The meat analog blend was FFS, wheat gluten, and corn starch (0.5:0.4:0.1), and oyster mushroom was added to the base formulation (0, 4, 8, and 12%). The extrusion condition was set to 55% feed moisture, 170oC barrel temperature, and screw speed of 150 rpm by using the twin-screw extruder equipped with a cooling die. The hardness, chewiness, cutting strength, and integrity index of the FFSbased extruded meat analog increased with the increase in oyster mushroom contents, while its nitrogen solubility index (NSI) decreased. The cohesiveness, springiness, and water holding capacity revealed the inconstant patterns with the increase in oyster mushroom contents. The total phenolic content and DPPH radical scavenging activity significantly increased with the increase in oyster mushroom contents. In conclusion, the incorporation of the oyster mushroom into the FFS-based meat analog enhanced the textural properties and antioxidant activity.