This study was performed to determine the effects of soil and building materials on indoor radon concentration. Short-term measurements were made in the underground soil of a building along with the radon emanation rates from the phosphogypsum board used as the interior wall. The radon measurements in the soil were 9,213 Bq/m3 in the B3 level, and 3,765 Bq/m3 in the B4 level. Soil radon concentration in the B4 level was 2.4 times higher than in the B3 level. Indoor radon measurements in 50 different locations in the underground of the building, averaged from 144.3 Bq/m3 (B1), 177.0 Bq/m3 (B2), and 189.2 Bq/m3 (B3) to a high of 210.1 Bq/m3 (B4). Indoor radon concentration was increased from the lower level to the upper level. The radon emanation rates from phosphogypsum were 4,234.1 mBq/m2/h and, 450.4 mBq/kg/h. The measurement results indicated that the phosphogypsum board used as building materials as well as the soil could affect the indoor radon concentration.

이 글은 중국어 평가와 교육의 변화에 주목하면서 HSK 교과교육에서 다루어야 할 교육내용을 파악하기 위한 목적으로,『新HSK大綱(2015)』의 ‘話題大綱’을 기준 삼아 新HSK 5급 기출문제의 화제 범주를 분석하고 출제의 경향성을 고찰한 것이다. 먼저, 교육기준인『國際大綱 (2014)』의 ‘漢語敎學話題’와 평가기준인『新HSK大綱(2015)』의 ‘話題大綱’을 비교하고『新HSK大 綱(2015)』의 ‘話題’가 등급별로 범주와 항목이 체계적으로 확정되어 있음을 살펴보았다. 다음으로, 2012년과 2014년 기출문제의 화제 범주를 분석하여 新HSK 5급의 화제 범주는 사회생활을 체험해야 하는 학습자의 상황을 전제로 한 내용들이고 일상생활이 가장 높은 분포율을 보였음을 파악하였다. 마지막으로, 新HSK 5급 기출문제의 화제 범주와 항목 내용을 중심으 로 新HSK 5급의 출제 경향을 논의하였다. 일상생활, 과학기술, 자연, 경제 범주의 문제는 주로 현실을 반영하고 있고, 문학예술, 체험적 깨달음, 일과직업, 문화, 교육 범주의 문제는 주로 사회적 가치를 판단하고 있음을 밝혔다. 분포율에 근거할 때, 현실을 반영하는 문제가 가치를 판단하는 문제보다 비중이 높았음을 고찰하였다.

A new deformation micromechanism operating in the carbon cathode for aluminum electrolysis termed a ripplocation has been proposed in this paper. The creep deformation of semi-graphitic cathode was measured using a modified Rapoport equipment at 965 °C with cryolite ratio = 4.0. The characteristic of the defect was obtained by analyzing TEM photograph of the carbon cathode with different testing times. The results indicated that basal dislocations, bulk ripplocations, kink bands and delamination cracks appeared in succession in the first two stages of the creep deformation. Ripplocations in the carbon cathode make a layer of carbon atoms to glide relative to each other without damaging the in-plane bonds. Ripplocations could also attract each other and result in kink boundaries. The creep strain of the carbon cathode could be accommodated by kink band and delamination cracks during aluminum electrolysis. A more comprehensive understanding of their micromechanics behaviors is very important and could deeply influence our current knowledge of the deformation mechanism of the carbon cathode for aluminum electrolysis.

This research combines the liquid carbon precursor infiltration process for carbon/carbon composites with the fabrication procedure for organic, carbon-matrix friction materials in automotive. In the densification process, different liquid carbon precursors and numbers of densification cycle are adopted to investigate the influence on physical and mechanical properties, microstructure and tribological behavior. Experimental results indicate that the infiltration of liquid carbon precursors could improve the physical, mechanical properties and tribological performances of organic friction materials. The open porosity decreases with the number of densification cycle. Both bulk density and hardness increase with the number of densification cycle. The resin-based specimens show higher hardness and lower open porosity than those of the pitch-based specimens after each densification cycle. The tribological measurement of specimens with different carbon precursors shows that the pitch-based specimen shows lower and more stable friction coefficients and exhibits lower weight losses in comparison with other carbon precursors. Morphological observations show that a large area of smooth lubricative film was easily presented on the worn surfaces of the pitch-based specimens, whereas it was seldom observed on the worn surfaces of the preform specimen and resin-based specimens.

In this study, we investigated the properties of adhesive materials with different lightweight materials such as CFRP and Al-foam. The specimens were tested and analyzed using DCB (Double Cantilever Beam) specimens. In order to secure the reliability of the finite element method, the test and analysis were carried out, and the reliability of the finite element method was secured by using the graph of reaction force to displacement based on the experiment and analysis. The study on the adhesive failure characteristics according to the position of notch hole proceeded. Notch holes were generated at the locations of 40, 110, 150 and 190 mm from the beginning of the specimen near the bonding interface, and the analysis conditions used were the same as those used for securing reliability. The obtained study results are compared with reaction force and equivalent stress. In the case of reaction force, the overall tendency is similar but the difference in maximum reaction force is found. It was found that higher reaction forces appeared at the beginning than at the end of the bonding interface. When the equivalent stresses in the specimens were examined, the value of CFRP was seen to be 30 times higher as much as that of Al-foam.

완제품 제조업 중심의 성장을 진행한 한국경제는 소재부품산업의 경쟁력 강화를 통한 산업고도화를 지향하고 있다. 소재부품산업은 기존 핵심산업의 경쟁력 유지 및 4차 산업혁명 시대에 요구되는 신산업의 육성 측면에서 더욱 주목받고 있다. 이러한 중요성에도 불구하고, 소재부품산업의 효율적인 R&D를 위한 연구가 매우 부족한 현황이다. 본 연구는 정부의 소재부품기술개발사업 성과 데이터를 기반으로 R&D 효율성 분석과 이에 기업규모 와 협력유형이 미치는 영향에 대하여 탐색적 연구를 진행하였다. 분석결과, 전반적으로 R&D 효율성은 낮은 것으로 나타났으나, 이는 경제적 성과가 반영된 산출변수 설정에 기인한 결과로 판단한다. 중소기업이 주관기관일 경우가 대기업보다 규모 성과가 우수한 것으로 나타났으며, 산학연이 협력할 경우가 그렇지 않은 경우와 비교하여 성과가 저조한 것으로 나타났다. 본 연구의 결과는 연구개발 수행기관 및 협력유형에 따른 R&D 성과 창출에 대한 시사점을 제시하였다. 이는 국내 소재부품산업이 당면한 질적 성장을 위한 산업정책 기획, R&D 투자 및 배분 전략 수립에 도움을 줄 것으로 기대한다.

Sustainable biomass-derived porous carbons demonstrate excellent capacitive properties owing to their heteroatom-rich nature and distinct textural feature. Herein, a series of nitrogen-/phosphorus-/oxygen-containing microporous carbons (CWWN/ P/O-MPCs) have been successfully fabricated by etching in H2O2 solution, pre-treatment of camphor wood wastes with KOH solution and subsequent carbonization. As an electrode material for supercapacitors, the typical microporous carbon (CWW-N/P/O-MPCs-0.5) exhibits a remarkably high specific capacitance of 245 F g− 1 at 0.5 A g− 1, corresponding to an impressively large volumetric capacitance of 208 F m− 3, and excellent long-term stability over 10,000 cycles. The excellent electrochemical performance can be ascribed to the optimal combination of heteroatom groups and ultrafine micropores.

손드하임의 뮤지컬은 20세기 후반의 미국 극장예술의 새로운 양식을 갈망하는 사람들에게 해답을 주었다. 그의 뮤지컬 음악은 각 대본과 극중 인물에 대한 깊은 이해와 고찰의 결과물이다. 또한 다양한 장르의 음악과 그 수준을 따지지 않고 활용하는 그의 비범한 절충주의의 결과이다. 이 논문에서는 그의 대표 뮤지컬 중 몇 장면을 음악적인 측면으로 분석하고 사용된 작곡 소재와 기법을 화성, 선법, 리듬, 텍스처, 형식 구성 원리 등의 측면에서 살펴본다. 그리고 그 결과 어떻게 극의 총체적 예술성에 공헌하고 있는지를 살피고 왜 그의 뮤지컬이 미국 고전으로 남을만한 가치가 있는지에 대해 논의한다.

We fabricated glucose oxidase (GOx)-modified biosensor for detection of glucose by physical immobilization of GOx after electrochemical polymerization of the conductive mixture monomers of the 3-thiophenecarboxylic acid (TCA) and thiophene (Th) onto ITO electrode in this study. We confirmed the successfully fabrication of GOx-modified biosensor via FT-IR spectroscopy, SEM, contact angle, and cyclic voltammetry. The fabricated biosensor has the detection limit of 0.1 μM, the linearity of 0.001-27 mM, and sensitivity of 38.75 mAM-1cm-2, respectively. The fabricated biosensor exhibits high interference effects to dopamine, ascorbic acid, and L-cysteine, respectively. From these results, the fabricated GOx-modified biosensor with long linearity and high sensitivity could be used as glucose sensor in human blood sample.

Chlorella-derived activated carbon (CDAC) with a high specific surface area and hierarchical pore structure was prepared as a CO2 adsorbent and as a supercapacitor electrode material. During KOH activation of Chlorella-derived carbon, metallic K gas penetrated from the outer walls to the inner cells, and pores formed on the outer frame and the inner surface. Micropores were dominant in CDAC, contributing toward a high specific surface area (> 3500 m2/g) and a hierarchical pore structure owing to the cell walls. Consequently, CDAC exhibited a high CO2 adsorption capacity (13.41 mmol/g at 10 atm and room temperature) and afforded high specific capacitance (142 F/g) and rate capability (retention ratio: 91.5%) in supercapacitors. Compared with woody- and herbaceous-biomass-derived activated carbons, CDAC has a superior specific surface area when the precursors are used without any pretreatment under the same conditions due to their soft components such as lipids and proteins. Furthermore, developing microalgae into high-value-added products is beneficial from both economic and environmental perspectives.