산업발달과 함께 환경오염이 심해짐에 따라 환경성 질환 또한 증가하고 있다. 이에, 맑은 공기, 깨끗한 물에 대한 일반 대중들의 관심이 높아지면서 정수기, 공기청정기 등 오염물질로부터 노출을 감소시킬 수 있는 제품들이 필수 구매용품처럼 인식되어 가고 있다. 이러한 제품 수요는 증가하는 반면, 제품의 규제준수 및 제품 내 함유물질에 대한 안전성 측면에서의 관리체계는 부족한 실정이다. 국내ㆍ외적으로 살생물제를 포함한 화학물질 및 유해화학물질을 함유하고 있는 제품 사용으로 발생될 수 있는 인체/환경에 대한 노출을 관리하기 위한 규제가 강화되고 있으며, 유해물질 함유 제품에 대한 안전성 확인의 시급성 또한 거론되고 있으므로 소재개발에서부터 함유물질에 대한 규제 및 안전성 확인이 이뤄져야 한다.

Porous materials play a vital role in science and technology. The ability to control their pore structures at the atomic, molecular, and nanometer scales enable interactions with atoms, ions and molecules to occur throughout the bulk of the material, for practical applications. Three-dimensional (3D) porous carbon-based materials (e.g., graphene aerogels/hydrogels, sponges and foams) made of graphene or graphene oxide-based networks have attracted considerable attention because they offer low density, high porosity, large surface area, excellent electrical conductivity and stable mechanical properties. Water pollution and associated environmental issues have become a hot topic in recent years. Rapid industrialization has led to a massive increase in the amount of wastewater that industries discharge into the environment. Water pollution is caused by oil spills, heavy metals, dyes, and organic compounds released by industry, as well as via unpredictable accidents. In addition, water pollution is also caused by radionuclides released by nuclear disasters or leakage. This review presents an overview of the state-of-the-art synthesis methodologies of 3D porous graphene materials and highlights their synthesis for environmental applications. The various synthetic methods used to prepare these 3D materials are discussed, particularly template-free self-assembly methods, and template-directed methods. Some key results are summarized, where 3D graphene materials have been used for the adsorption of dyes, heavy metals, and radioactive materials from polluted environments.

This study is based on the screen printing method with heat resistant thin film as base material and development for expansion is proceeding. Therefore, it is convenient to be applicable to the installation and it will be possible to reduce the cost compared with the existing construction such as heat trace by 50% or more. As a result, it is possible to develop and commercialize the market for Polar ship, shipbuilding and offshore plants as it is possible to secure CNT(Carbon Nano Tube) based surface heating element and heating paste composition technology as a heating element material at a cryogenic temperature. It is expected that the efficiency will be great when this method is applied to other industries.

In this study, the heating block for 3D printer has a problem that heat is transferred to the filament guide portion to dissolve the filament, thereby preventing the filament from being discharged quickly out of the nozzle. In order to solve these problems, the cladding with different thermal conductivity was fabricated and the heating block was manufactured. The properties of the fabricated clad material and the surface temperature of the fabricated heating block were measured and the following conclusions were obtained. As a result of modeling thermal analysis of the heating block made of the clad material developed in this study rather than the existing heating block, the surface temperature of the filament guide portion was predicted to be lower than the surface temperature of the heating portion. The shear strength of the clad material developed in this study was measured and the average value of 82.8 MPa was obtained. The thermal conductivity of the existing heating block was 237W/m K at 300K. The thermal conductivity of the heating block made of the clad material ⋅ developed in this study was 81.416W/m K, which is lower than the conventional thermal conductivity. The ⋅ surface temperature of the heating block made of the clad material developed in this study is 172.3℃, which is lower than that of the conventional heating block. Future research is to evaluate the thermal distribution by using a metal with a lower thermal conductivity than carbon steel and by cladding pressure, evaluating the physical properties of the clad material, and fabricating it as a heating block.

In this paper, the method of vibration analysis for calculating the natural frequency is presented. This method is a simple but exact method of calculating natural frequencies corresponding to the modes of vibration for the cantilevered composite materials conical beam. The influence of natural frequency of the cantilevered composite materials conical beam is presented. This method may be extended to stability analysis of complex structureal elements.

Since the settlement of the underground ground occurred in Seok-Chon Underground Roadway in Seoul from August 2014, the social interest of ground stability has increased. Thus, in this paper, We introduce not only the legal counterplan about the ground settlement but also a result of study on how many new materials can be used in the repairing of ground settlement.

This study investigates the trend on application technologies of advanced composite materials and outlook on research development to the challenges associated with innovative applications of advanced composite materials in construction: 1) initiation of new construction materials; 2) development of rehabilitation techniques for aging infrastructural systems; 3) implementation of greener construction approaches; and 4) introduction of multifunctional advanced composite materials. This fundamental investigation will assure wide field implementation of advanced composite materials in construction.

This study was carried out to elucidate suppressive effect of loess-sulfur complex and neem oil on the development of leaf mold and fungus gnat in no-pesticide tomato farming system. Since tomato leaf mold occurred 15%, neem oil, loess-sulfur mixture and boscalid(47%, water soluble chemicals) 2,000 times, 1,000 times and 2000 times diluted was treated three times, respectively. When disease incidence of tomato leaf mold was investigated 20 days after final treatment, it was recorded 17% in neem oil treatment(control efficacy 40%) and 12.3% in loess-sulfur mixture treatment(control efficacy 59%). Among three control agents used, Boscalid(47%, water soluble chemicals) showed the best control effect against tomato leaf mold. When neem oil was diluted 250 times, 330 times and 500 times and treated in coir bag infected with fungus gnat, its control values was 69, 59, and 55%, respectively. There was no significant difference among three treatments. As a result, 500-fold diluted neem oil treatment is considered a good measure to control fungus gnat in the field condition.

Anthracene has been a motive molecule for the blue-emitting materials in OLED. Since the blue emission needs big band gap between HOMO and LUMO, the blue-emitting materials are rare. In this paper, some anthracene derivatives containing simple aryl groups are synthesized and characterized. Regardless of the substituents the absorption and the emission bands are similar to each other and similar to the derivatives with the bulky silyl groups. The thermal and the CIE tests imply that among the tested 9-(2-naphthyl)-10-phenylanthracene is most promising for the diode. The material for the emission layer has to be investigated, which is simple to be prepared as well as good in the electrical and the thermal properties.

목적: 재질이 다른 하루 교체용 소프트 콘택트렌즈(daily disposable soft contact lens: DDCL)의 자각적 증상, 타각적 증상 및 눈물막을 비교하였다. 방법: 소프트 콘택트렌즈를 착용하고 있는 33명(남: 2명, 여: 31명 ; 평균 21.94±1.58세)을 대상으로 재 질이 다른 세 종류(A;Nesofilcon A, B;Omafilcon A, C;Etafilcon A)의 DDCL을 단일맹검법을 사용하여 하 루 8시간 이상 2주 동안 양안에 착용하도록 하고 콘택트렌즈 피팅상태(중심잡기, 래그, 푸쉬업 검사), 자각 적 증상의 빈도와 정도, 타각증상 및 눈물막 검사 결과를 비교하였다. 결과: 세 종류의 콘택트렌즈 모두 피팅 상태가 적합한 것으로 나타났고, A 렌즈가 다른 렌즈보다 중심이 탈이 적고(p=0.000), 래그(Lag), 푸쉬업(push-up) 움직임이 적었다(p<0.01). 자각적 증상의 빈도(frequency) 와 정도(intensity) 평가에서는 재질에 따른 차이가 없었고, 타각적 증상은 A 렌즈가 다른 렌즈보다 결막충 혈과 염색(staining)이 더 많았고(p<0.05), NIBUT(noninvasive break-up time)와 TBUT(tear break-up time)는 A 렌즈가 다른 렌즈보다 길었다(p=0.000, p=0.008). 결론: 재질이 서로 다른 세 종류의 DDCL 착용 후 재질에 따른 자각적 증상은 차이가 없었고, 눈물막 안 정성과 타각적 증상은 차이가 있었으나 눈물막 안정성, 자각적 증상 및 타각적 증상 사이에 상관성은 확인할 수 없었다.

감마분광분석 시스템 상에서는 226Ra(186.2 keV)과 235U(185.7 keV)가 방출하는 감마선 에너지의 피크 중첩이 발생한다. 226Ra의 직접분석을 위해서는 중첩된 피크로부터 235U의 기여를 제거해주거나 보정상수를 이용하여 실제 226Ra의 방사능 값 으로 보정 해주어야 한다. 235U가 방출하는 다른 감마선 피크를 참조하여 235U의 기여를 제거할 경우 복잡한 수계산이 필요하며, 참조피크에서 기인하는 큰 불확도로 인해 높은 정량한계를 갖는다. 반면에 보정상수를 이용하여 226Ra을 평가할 경우 간단한 계산으로 평가가 가능하며, 간접측정시 요구되는 222Rn의 용기건전성과 방사평형 복구기간이 필요하지 않아 226Ra의 신속 측정시 유용한 방법이다. 따라서 해당 방법을 통해 원료물질 3종과 공정부산물 3종, 총 93여개 시료에 대해서 보정상수로 산출된 226Ra의 방사능 농도와 방사평형 된 214Bi의 방사능 농도의 비교를 통해 유효성을 확인하였다. 대부분 ± 20% 내에서 유효하였지만 인산석고의 경우 약 50%의 오차를 보였다. 이는 보정상수를 유도하기 위한 가정 중 238U과 226Ra의 방사평형 관계가 달라진 것으로 판단된다. 특이성을 반영한 보정상수를 적용하여 226Ra의 방사능 농도에 대한 유효성을 평가한 결 과 약 ±10%로 좀 더 정밀한 결과를 얻을 수 있었다. 본 연구에서 산출된 보정상수를 통한 226Ra의 방사능 농도 평가 방법은 복잡한 수계산이 필요하지 않고 용기선택으로부터 자유로우며 방사평형 복구를 위한 기간이 필요하지 않아 원료물질 및 공정부산물의 226Ra의 신속한 농도 분포 평가시 유효한 방법이다.

This study analyzed that the standard of school supplies affects the satisfaction of certification. Safety requirements of school supplies in the Republic of Korea is enforced by court duty certification. Therefore, a test was conducted to compare the safety requirements of the United States and Europe and the survey was conducted to know how much manufacturers and importers are satisfied with the certification. To prepare management measures for harmful substances contained in children's product, XRF(X-ray Fluorescence Spectrometry) is utilized to analyze lead(Pb) and cadmium(Cd) in PA(paint), SP(sheet) and PVC(Poly Vinyl Chloride). The results of comparative analysis of ICP(inductively coupled plasma) is analyzed statistically with measured values.

Nowadays, advanced composite material are widely used in civil & architectural structures. Analysis of foam core sandwich bridges for simple supported made by advanced composite materials is presented in this paper. For the design of advanced composite materials bridge, foam core shape is economical and profitable. Navier’s solutions are compared in this paper to verify the authenticity of Finite Difference Method. Finite Difference Method is used for analysis of the pertinent problems. In this study, reduction rate of tensile strength for E-glass fibers due to increase in size, strength reduction ratios of according to mass, stress changes according to form core height and safety ratio due to increase form core height is presented. Tasi-Wu failure strength theory are used. Strength reduction is necessary for safe design of a structures.

There has been growing concern over the emissions of formaldehyde and VOCs from automotive interior materials, as these could have an important impact on the in-vehicle air quality (IVAQ) of automotive vehicles. Odor along with VOCs refers to the automotive interior smell emitted directly or indirectly from any part of an automotive interior, based on human olfactory senses and a comfort evaluation of vehicle quality. The objective of this paper is to compare the odor intensity using GC/MS analysis method and odor sensory test in accordance with ISO 12219-2. For the compounds having low odor threshold value and high VOC concentration, it was found that there was the same tendency in each field of odor whether the instrument analysis method or the odor sensory test method was used.

최근 전 세계적으로 급속한 도시화, 인구증가 및 기후변화에 따른 물의 수요와 공급의 불균형으로 인해 물 산업 의 경제, 사회, 환경적 중요성은 더욱 증가하고 있다. 이러한 물 산업은 크게 해당 분야에 따라 사용되는 분리막의 종류가 상 이하다. 주로 물리적, 화학적 안정성이 매우 우수한 고분자 소재가 사용되고 있으나, 이들 고분자들의 소수성인 성질 때문에 친수성을 부여하는 다양한 방법들이 소개되고 있다. 본 연구에서는 상용화되어 있는 중공사 지지체에 총 4종류의 친수성 고 분자들을 도입하여 친수성을 부여하였고, 주사전자현미경을 통해 코팅된 중공사 지지체의 모폴로지를 확인하였다. 또한, 각 고분자들로 코팅한 중공사 지지체의 친수화 정도를 알아보기 위해 접촉각을 측정하였고, 마지막으로 코팅 시간에 따른 수투 과도 변화 그리고 친수성 고분자에 따라 수투과도에 미치는 영향을 확인하였다. 그 결과 Pluronic 1 wt%로 코팅하였을 때 친 수화 정도가 우수하며 중공사의 기공을 막지 않고 우수한 수투과도 정도를 나타내 수처리 분리막으로 가장 적절하다는 결론 을 얻을 수 있었다.

Silicon alloys are considered promising anode active materials to replace Li-ion batteries by graphite powder, because they have a relatively high capacity of up to 4200 mAh/g, and are environmentally friendly and inexpensive ECO-materials. However, its poor charge/discharge properties, induced by cracking during cycles, constitute their most serious problem as anode electrode. In order to solve these problems, Si-Ge-Al alloys with porous structure are designed as anode alloy powders, to improve cycling stability. The alloys are melt-spun to obtain the rapidly solidified ribbons, and then ball-milled to make fine powders. The powders are etched using 1 M HCl solution, which gives the powders a porous structure by removing the element Al. Subsequently, in this study, the microstructures and the characteristics of the etched powders are evaluated for application as anode materials. As a result, the etched porous powder shows better electrochemical properties than as-milled Si-Ge-Al powder.

Fishing pots are one of the important fishing gears in our coastal and offshore fisheries. In terms of a sustainable use of marine resources, there are concerns about the ghost fishing by lost pots. It is reported that 10 to 70% of the pots are abandoned or lost annually. This study is to compare the catching efficiency of drum type whelk pots that are made of biodegradable nets to those made of the ordinary nets, in the eastern coast of Korea. Five types of drum pots were used with combination of biodegradable nets and ordinary (PA, PE) nets applied to the main and funnel parts of the pots: pots with biodegradable nets (Bio+Bio); pots with PE net (PE+PE); pots with body and funnel made of biodegradable nets and PE nets respectively (Bio+PE); pots with body and funnel made of PE nets and PA nets respectively (PE+PA); pots with body and funnel made of PE nets and biodegradable net respectively (PE+Bio). Field experiments were conducted from June 18th, 2015 to August 7th, 2015 using a commercial fishing vessel in the Uljin waters on the eastern coast of Korea. Two fleets of pots with one hundred in each, 20 pots of each type, were casted for 8 to 15 days to analyze their catching efficiency. The catch of target species, whelks, was 202,563.0 g with catch rate of 38.7% of the total catch, while the bycatch was 320,709.7 g with the rate of 61.3% of the total catch. The catch of whelks was the highest in the Bio+PE pots (46,020.3 g), followed by the Bio+Bio pots (42,027.5 g), the PE+Bio pots (41,849.9 g) and the lowest being PE+PE pots (38,054.2 g). Compared to the conventional pots, the pots with biodegradable nets on the body or entrance part had slightly higher catch rate for both the target species and the bycatch. The PE+PE had the lowest catch rate. There is no significant difference in catch between the pots with biodegradable nets and the ordinary nets for the target species such as Buccinum opisthoplectum, Neptunea eulimata, Buccinum striatissimum. Consequently, using biodegradable nets for the conventional whelk pots can reduce ghost fishing by lost gears while keeping the performance of the pots.

국내 유통중인 다양한 형태의 원료물질 또는 공정부산물들에 대한 물리적, 화학적 및 방사선적 특성을 평가하기 위해 약 220 여 개, 총 16 종의 표본 시료를 선정하였다. 해당 시료들에 대하여 LaBr3 섬광검출기를 이용한 에너지 스펙트럼 측정과 에너 지 분산형 X-선 형광 분광기를 이용한 U, Th, K와 물질의 주요 성분 분석을 수행하였다. 그리고 HPGe 검출기를 이용하여 234Th, 234mPa 및 214Bi 등의 우라늄 붕괴계열 핵종들과 228Ac, 212Pb 및 208Tl 등의 토륨 붕괴계열 핵종들 그리고 40K 등의 방사능 농도를 분석함으로써 원료물질 및 공정부산물의 특성에 관한 기초자료를 수집하였다. 추가적으로 ROI구간별 계수율과 원 소성분함량, 방사능농도와 같은 특성변수들 간의 상관관계를 분석함으로써 스크리닝 장비를 이용한 방사능 농도 분포 유추 가능성을 평가하였다. 본 연구에서 구축된 특성 데이터베이스는 천연방사성핵종 분석을 위한 절차 및 방법을 수립하는데 유 용한 정보를 제공하고, 천연방사성핵종 분석에 대한 정확성 및 재현성을 향상시킬 수 있을 것으로 판단된다