본 연구는 코팅 방법을 활용한 단결정 양극 소재 연구로서 Ni-rich계 다결정 양극 소재로 부터 단결정 양극 소재를 합 성하여 사이클 구동 시 양극 소재의 안정성을 향상시키고자 한다. 양극 소재에 LixCoO2와 LixSnO3 를 각각 코팅하여 이차입자 내부 혹은 외부에 코팅층이 형성된 양극 소재를 합성한 후 이를 소결하여 단결정 형성에 대한 영향을 비교 하였다. 입자 외부에 LixSnO3가 코팅되어 열처리 된 Ni0.8Co0.1Mn0.1O2(NCM811)의 경우 코팅 처리 없이 열처리된 양극 소재 보다 개선된 수명특성을 보였으나, 단결정화가 이뤄지지 않았다. 입자 내부에 LixCoO2 코팅층이 형성된 NCM811 을 열처리 한 결과 이차입자 내부에 형성된 Co 코팅층이 결정화되어 50회 사이클 후 기준 단결정 양극 소재의 방전용 량인 117.34 mAh·g-1 대비 129.11 mAh·g-1의 높은 방전용량을 나타내었고, 형상제어를 통해 이성적인 단결정화가 이뤄 졌다. 본 연구는 다결정체인 Ni-rich 양극소재의 단결정화에 대한 유요한 통찰력을 제공할 것으로 예상한다.

Upgraded activated carbons (ACs) are typically synthesized by mixed methods, such as solid–solid mixing and wet impregnation of low-grade ACs with KOH. This study compares the properties of upgraded ACs prepared by different methods using elemental analysis, X-ray photoelectron spectroscopy, N2 adsorption isotherms, and X-ray diffraction. In ACs produced by the solid–solid mixing, the ratio of potassium activator is proportional to the surface area and amount of gas produced. However, in wet impregnated ACs, the potassium ratio exhibits a zero or negative correlation. It is demonstrated that potassium ions in solution are not transferred to K2O and do not contribute to the surface area and pore size, generating less amount and different composition of gases. As such, impregnated ACs exhibit similar surface areas and large pores, regardless of the potassium ratio. The physical properties, such as specific surface areas and pore size distribution, of ACs using wet impregnation were similar to the ACs generated by the water physical activation. It indicated that the KOH does not efficiently act as a chemical activator in the wet impregnation method. Therefore, a certain amount and suitable mixing method of chemical activator play an important role in the property upgrade of ACs.

상법 제795조 제2항과 제796조는 운송인의 손해배상책임에 대한 다양한 면책 사유를 규정하고 있다. 상법상 위와 같은 운송인의 면책사유들은 그 법적 성질 과 요건이 각 상이하다는 차이점은 있으나, 그 논리적 전제로서 운송도구로서의 감항능력을 갖춘 선박과 함께 선박을 조종하는 인적요소로서의 선원 등을 구비할 것을 공통적으로 요구하고 있다. 그런데 최근의 정보공학기술 및 인공 지능 등의 발전에 따라 과거에 인간에 의해 이루어지던 운송수단의 조종이 무인화 되고 있고, 해상운송에 있어서도 무인선박의 건조 및 운항이 현실화되고 있다. 조만간 상용화될 것으로 예상되는 무인선박의 운항은 기존 해상운송 법 제와 전반적인 측면에서 법리적 문제를 발생시킬 것으로 예상되는데, 특히 무인선박의 운항이 상법 795조 제2항과 제796조가 규정하는 면책사유의 해석과 적용에 어떤 영향을 미칠 것인가 하는 점에 대한 고찰은 실천적 가치가 있다. 무인선박의 경우 운송인 등의 감항능력주의의무 위반사실이 인정되지 않는 한, 선내에 선원이 승선하지 않는다는 점에서 원칙적으로 선원 등의 항해과실을 이유로 한 면책이 적용될 소지는 없다고 볼 것이다. 또한 무인선박의 경우에는 선박의 운항을 위한 각종 정보통신 관련 기기 및 전자장비가 유인선박에 비해 상대적으로 더 많이 장치되어야 한다는 점에서 이들 운항 관련 장비들의 적절 한 유지 · 관리상 과실로 인해 발생한 손해에 대해서는 운송인 등이 면책될 소지도 있을 것이나, 상법 제796조에서 규정하는 법정면책사유 중 하나인 「선박 의 숨은 하자」와의 관계에 있어서는 해석상 어려운 문제를 제기한다. 나아가 상법 제796조가 규정하는 법정면책사유인「해적행위나 그 밖에 이에 준한 행위」·「해상에서의 인명이나 재산의 구조행위 또는 이로 인한 항로이탈이나 그 밖의 정당한 사유로 인한 항로이탈」·「선박의 숨은 하자」의 해석과 관련해서 도법적 문제가 제기될 수 있다. 특히「해적행위나 그 밖에 이에 준한 행위」 의 해석 · 적용과 관련해서는 외부의 제3자가 자율운항선박의 운항장비 등을 해킹하는 등 불법적으로 통제하는 방법으로 자율운항선박 및 운송물의 점유를 취득하는 경우에 현행 법제상 운송인이 면책될 수 있을 것인가 하는 문제가 있다. 입법론으로서, 향후 사이버 해킹 등을 통한 선박 등의 탈취행위의 경우에도 일정한 요건 하에서 운송인의 면책을 허용할 수 있도록 포괄적 면책규정을 상법 제796조에 신설할 필요가 있다.

본 연구는 피부표면온도가 유효물질 경피 흡수와 피부 상태변화에 미치는 영향을 실험하였다. 열에 강한 나이아신아마이드 10% 에멀젼을 인공피부에 도포하여 경피 흡수 시험을 진행하였고 동일한 에멀젼으로 피부임상시험을 시행하여 온열효과를 확인하였다. 그 결과 피부표면 온도 42℃에서 정상 피부 온 도보다 도포 10분 경과 후 2배, 15분 경과 후 3배의 경피 흡수 효과를 보였다. 피부임상평가에서는 임상대상자 모두 특이한 이상반응을 보이지 않았으며 수분, 유분 항목에서 통계적으로 유의한 효과를 나타냈다. 이상의 결과로 온열은 유효물질 경피 흡수 촉진과 피부상태 개선에 긍정적인 영향을 미치는 것을 확인하였고 이는 온열을 이용한 다양한 뷰티디바이스 개발에 기초자료가 될 것으로 판단된다.

본 연구는 표면 반응 분석법을 이용하여 곤드레 데치기 최적 공정 조건을 확립하고 각각의 공정으로부터 생산된 곤드레 추출물로부터 총 페놀 화합물, 플라보노이드의 함량, DPPH 라디칼 소거능 을 분석하였다. 최적 공정 확립을 위한 데치기 공정 범위로 온도는 70℃ - 99℃, 시간은 70 - 170 sec. 로 하였다. 데치기 공정 후 총 페놀 함량의 범위는 13.00 - 35.48 mg/g 이고 최대 예측 총 페놀함량은 35.48 mg/g, 총 페놀 함량의 경향을 보면 데치기 온도에 따라 급격히 감소하다가 증가하는 것으로 보 여 지므로 온도에 의해 더 많은 영향을 받는 것으로 나타난다. 플라보노이드의 함량의 범위는 2.31 - 8.38 mg/g 이고 최대 예측 플라보노이드 함량은 8.38 mg/g 이었다. 플라보노이드 함량의 경향을 보면 데치기 시간에 따라 서서히 증가하다가 급격히 감소하는 것으로 보여 지므로 시간에 의해 더 많은 영향 을 받는 것으로 나타났다. DPPH 라디칼 소거능의 범위는 42.10 - 67.14%이고 최대 예측 DPPH 라디 칼 소거능은 67.14%로 측정 되었다. DPPH의 경향을 보면 데치기 온도에 따라 증가하다가 급격히 감소 하는 것으로 보여 지므로 온도에 의해 더 많은 영향을 받는 것으로 나타난다. 따라서 데치기 공정 최적 조건은 온도 85℃와 시간 150 sec. 로 결정되었다.

Multi-walled carbon nanotube (MWCNT)/polycarbonate (PC) nanocomposite was prepared by direct melt mixing to investigate the effect of the shear rate on the surface resistivity of the nanocomposites. In this study, an experiment was carried out to observe the shear induced orientation of the MWCNT in the polymer matrix using a very simple melt flow indexer with various loads. The compression-molded, should be eliminated. MWCNT/PC nanocomposite sample exhibited lower percolation thresholds (at 0.8 vol%) and higher electrical conductivity values than those of samples extruded by capillary and injection molding. Shear induced orientation of MWCNT was observed via scanning electron microscopy, in the direction of flow in a PC matrix during the extrusion process. The surface resistivity rose with increasing shear rate, because of the breakdown of the network junctions between MWCNTs. For real applications such as injection molding and the extrusion process, the amount of the MWCNT in the composite should be carefully selected to adjust the electrical conductivity.

In this work, the effect of aminized multi-walled carbon nanotubes (NH-MWNTs) on the mechanical interfacial properties of epoxy nanocomposites was investigated by means of fracture toughness, critical stress intensity factor (KIC), and impact strength testing, and their morphology was examined by scanning electron microscope (SEM). It was found that the incorporation of amine groups onto MWNTs was confirmed by the FT-IR and Raman spectra. The mechanical interfacial properties of the epoxy nanocomposites were remarkably improved with increasing the NH-MWNT content. It was probably attributed to the strong physical interaction between amine groups of NH-MWNTs and epoxide groups of epoxy resins. The SEM micrographs showed that NH-MWNTs were uniformly embed and bonded with epoxy resins, resulted in the prevention of the deformation and crack propagation in the NH-MWNTs/epoxy nanocomposites.

The aim of this study was to investigate the effect of supporting surface instability to trunk and lower extremity muscle activities during bridging exercise combined with core-stabilization exercise. Thirty young healthy adults (15 males and 15 females) voluntarily participated in this study. Each subject was asked to perform bridging exercise combined with core-stabilization exercise on three different supporting surfaces (stable ground surface, the wooden balancing board, and the air cushion). The muscle activities were measured using surface electromyography (EMG) during performing exercise. To test statistical significance, one-way ANOVA with repeated measures was used with the significance level of .05. The findings of this study are summarized as follows. (1) There were significant differences in muscle activities on internal oblique, external oblique, gluteus medius, semitendinosus, biceps femoris, medial gastrocnemius and lateral gastrocnemius during exercise (p<.05). (2) The biceps femoris and lateral gastrocnemius showed significantly higher muscle activity on the wooden balancing board rather than on the ground, and semitendinosus, biceps femoris, medial gastrocnemius and lateral gastrocnemius showed significantly higher muscle activity on the air cushion rather than on the ground (p<.05). Therefore, it is concluded that muscle activities in the trunk and the lower limbs during bridging exercise combined with core-stabilization exercise was affected with instability of supporting surface. Further researches are needed to investigate the long term effect of bridging exercise on muscle activity with patient group.

The influence of carbon surface area, carbon-oxygen groups associated with the carbon surface and the solution pH on the adsorption of Pb(II) ions from aqueous solutions has been studied using three activated carbons. The adsorption isotherms are Type I of BET classification and the data obeys Langmuir adsorption equation. The BET surface area has little effect on the adsorption while it is strongly influenced by the presence of acidic carbon oxygen surface groups. The amount of these surface groups was enhanced by oxidation of the carbons with different oxidizing agents and reduced by eliminating these groups on degassing at different temperatures. The adsorption of Pb(II) ions increases on each oxidation and decreases on degassing the oxidized carbons. The increase in adsorption on oxidation has been attributed to the formation of acidic carbon-oxygen surface groups and the decrease to the elimination of these acidic surface groups on degassing. The adsorption is also influenced by the pH of the aqueous solution. The adsorption is only small at pH values lower than 3 but is considerably larger at higher pH values. Suitable mechanisms consistent with the adsorption data have been suggested.

The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. subject gazed the monochrome or the unique color, which was tailed target rotor. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling for the target color presented, the estimation of the unique color was cai\ulcornerlied out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law, The color difference saturated In the increase of area of background with the ratio more than 2:1.

The effect of surface free energy on the positive temperature coefficient (PTC) of carbon black/thermoplastic resin composites was investigated. The thermoplastic resins such as EVA, LDPE, LLDPE and HDPE were used with the addition of 30 wt.% of the carbon black. The surface free energy of the composites was studied in the context of two-liquid contact angle measurements, i.e., deionized water and diiodomethane. It was observed that the resistivity on PTC composites Was greatly increased near the crystalline melting temperature, due to the thermal expansion of polymeric matrix. From the experimental results, it was proposed that the decrease of surface free energy induced by interactions between carbon black surfaces and polymer chains is an important factor to the fabrication of a PTC composite made of carbon black and polymeric matrix.

The influence of the polarity of the spreading solvent on the properties of the monolayer of poly(styrene-co-acrylonitrile)'s with various acrylonitrile contents was studied. The surface pressure - area isotherm and the apparent dipole moment - area isotherm were obtained and analyzed when the mixtures of methylene chloride and N-N-dimethylformamide used as spreading solvent. The isotherms were strongly influenced by the polarity of the solvent.

Better understanding the mechanism of black ice occurrence on the road in winter is necessary to reduce the socio-economic damage it causes. In this study, intensive observations of road weather elements and surface information under the influence of synoptic high-pressure patterns (22nd December, 2020 and 29th January, and 25th February, 2021) were carried out using a mobile observation vehicle. We found that temperature and road surface temperature change is significantly influenced by observation time, altitude and structure of the road, surrounding terrain, and traffic volume, especially in tunnels and bridges. In addition, even if the spatial distribution of temperature and road surface temperature for the entire observation route is similar, there is a difference between air and road surface temperatures due to the influence of current weather conditions. The observed road temperature, air temperature and air pressure in Nongong Bridge were significantly different to other fixed road weather observation points.

Recently, a possibility of the surface treatment material is expected as an integrated control method for various degradations of concrete structure. However, as experimental results, although water permeability of the concrete could be improved due to the surface treatment material, the scaling of surface layer was accelerated under freezing and thawing cycles. Furthermore, the mechanism of scaling acceleration has not been clarified yet. Therefore, in order to clarify the mechanism accelerating the scaling of the treated concrete, the behavior of variations in the moisture and ice contents in the concrete were investigated especially based on a simulation analysis using a simultaneous heat and moisture transfer equation for a three-phase system. The analysis simulated the freezing-thawing process in the RILEM CIF/CDF test. And the mechanism accelerating the scaling is discussed based on the differences of the freezing behavior due to the infiltration depth of the surface treatment material. As the results, in the case of the smaller infiltration depth, it has been clarified that the reason to accelerate the scaling is the increasing of the ice content at the boundary between the treated and untreated regions.