In this study, N/S co-doped carbon felt (N/S-CF) was prepared and characterized as an electrode material for electric double-layer capacitors (EDLCs). A commercial carbon felt (CF) was immersed in an aqueous solution of thiourea and then thermally treated at 800 oC under an inert atmosphere. The prepared N/S-CF showed a large specific surface area with hierarchical pore structures. The electrochemical performance of the N/S-CF-based electrode was evaluated using both 3- electrode and 2-electrode systems. In the 3-electrode system, the N/S-CF-based electrode showed a good specific capacitance of 177 F/g at 1 A/g and a good rate capability of 41% at 20 A/g. In the 2-electrode system (symmetric capacitor), the freestanding N/S-CF-based electrode showed a specific capacitance of 275 mF/cm2 at 2 mA/cm2, a rate capability of 62.5 % at 100 mA/cm2, a specific power density of ~ 25,000 mW/cm2 at an energy density of 23.9 mWh/cm2, and a cycling stability of ~ 100 % at 100 mA/cm2 after 20,000 cycles. These results indicate the N/S co-doped carbon felts can be a promising candidate as a new electrode material in a symmetric capacitor.

As coffee consumption increases, coffee extraction's by-products increase. Research on coffee by-product recycling is fundamental as social costs and environmental problems arise from the course of coffee processing, estimated to be 270,000 tons per year. This study attempted to confirm the possibility of an eco-friendly food packaging material by solvating cellulose from spent coffee grounds. For cellulose solubility, delignification and TEMPO (2,2,6,6- tetramethylpiperidin-1-oxyl) oxidation treatment were performed. An optimal plasticizer (glycerol) and a crosslinking agent (cinnamaldehyde) were added to the film-forming solution for film manufacturing, while physical treatment (high-pressure treatment, 276 MPa, 10 times) was done to improve physical properties. Then, the film was dried by a solution-casting method. Physical properties of food packaging materials such as tensile strength, elongation, water-solubility, thickness, and chromaticity were measured. In particular, the film to which 1.5% glycerol was added showed the highest value among the physical properties of the dried film. These results indicate that TEMPOSCG films have potential as eco-friendly food packaging materials in the food industry.

This study was performed to evaluate the quality characteristics and antioxidant activity of Nurungji by varying the purple sweet potato powder addition time (AR: added after rice cooking, BR: added before rice cooking) and powder ratio (0, 2, 4, 6, 8%) on the prepared rice during Nurungji’s manufacturing. In both AR and BR samples, water binding capacity, soluble solid content, reducing sugar, and hardness increased with an increasing proportion of purple sweet potato powder; however, the pH and moisture content decreased. The L value and b value decreased and increased with the influence of anthocyanin in purple sweet potato powder. The total polyphenol, flavonoid, anthocyanin contents, DPPH, and ABTS radical scavenging activity were highest in Nurungji with 8% of purple sweet potato powder. Moreover, AR samples showed higher antioxidant activity than BR samples. Based on the study results above, the preparation of Nurungji with 8% purple sweet potato powder by AR process was more favorable based on the content of antioxidants and antioxidant activity.

A non-pneumatic tire (NPT), unlike a pneumatic tire, is a tire that acts as air pressure with spokes, and has the advantage of not requiring maintenance of air pressure and the risk of puncture of the pneumatic tire. Recently, many technological advances are taking place in non-pneumatic tire (NPT) using artificial intelligence technology, and non-pneumatic tire manufacturers are actively conducting research and development. Here, in order to compare and analyze the technological competitiveness of major patent applicants, non-pneumatic tire-related patents that have been applied for Japan, the United States, China, Korea, Germany, France, and the European Union Patent Office are reviewed through the patent applications of global tire manufacturers.

A porous photocatalyst concrete filter was successfully produced to remove NOx, by mixing TiO2 photocatalyst with lightweight aerated concrete. Ultra Fine Bubbles were used to form continuous pores inside the porous photocatalytic concrete filter, which was mixed via a bubble generation experiment. The optimal mixing condition was determined to be with 4% of the bubble generation agent B. NO removal specimens were prepared for various photocatalytic loading conditions, and the specimen containing 3% P-25 removed NO at a concentration of 1.03 μmol in 1 h. The NO removal rate of the porous photocatalytic concrete filter prepared in this study was 10.99%. This photocatalytic filter performance was more than 9 times the amount of NO removed by a general photocatalytic filter. The porous photocatalyst concrete filter for removing NOx developed in this study can be applied to various construction sites and the air quality can be solved by reducing NOx contributing to the formation of fine particles.

피마자 기반 수성 폴리우레탄(CPUD)을 얻기 위해 무 변성 피마자유 (CO) 와 투명 필름을 얻기 위해 이소포론 디이소시아네이트(IPDI)를 사용했다. 유연성을 증가시키기 위해 폴리프로필렌글리콜 (PPG)의 혼합 효과를 분석하였다. 또한, 사슬연장제로 에틸렌다이아민(EDA)을 사용했다. 각각 피마자유 함유에 따른 변화와 사슬연장제 변화에 따른 인장강도, 연신율 내마모성을 측정했다. 피마자유 함유가 많은 시료의 인장강도가 1.112kgf/㎟, 연신율 88%로 나타났으며, 사슬연장제 함유가 많은 시료의 인장 강도가 3.33kgf/㎟, 연신율 99%로 측정되었다. 표면강도는 SEM을 통해 육안으로 확인하였다.

화석연료의 사용에 따른 지구 온난화 및 기상 이변으로 인하여 온실가스 저감 문제가 대두되고 있으며, 그에 따 라 에너지 소모 없이 셀프 쿨링이 가능한 소재에 대한 연구가 활발히 진행되고 있다. 그 중에서도 실크는 천연 쿨링 소재로 알려져 있으나, 기존의 혼합 공정에서는 실크를 화학적으로 분말화 시키기 때문에 복사 냉각 효과가 사라지는 문제점이 있어, 복사냉각을 위한 필름 또는 코팅제 형태로 제조하는데 어려움을 겪고 있다. 본 연구에서는 실크 피브로인의 고유구조를 훼손 하지 않는 물리적 분쇄 공정을 거친 실크 분말을 사용하여 다양한 형태의 막을 제조하고, 코팅제로서의 적용가능성을 살펴보 고자 연구를 수행하였다. 이를 위해 실크 피브로인 분말이 도입된 전기방사 복합막 및 평막 형태의 복합막을 제조하였으며, 용액의 점도가 막 제조 및 제조된 막의 물성에 큰 영향을 미치는 것을 관찰하였다.

The CoCrFeMnNi high-entropy alloy (HEA), which is the most widely known HEA with a single facecentered cubic structure, has attracted significant academic attention over the past decade owing to its outstanding multifunctional performance. Recent studies have suggested that CoCrFeMnNi-type HEAs exhibit excellent printability for selective laser melting (SLM) under a wide range of process conditions. Moreover, it has been suggested that SLM can not only provide great topological freedom of design but also exhibit excellent mechanical properties by overcoming the strength–ductility trade-off via producing a hierarchical heterogeneous microstructure. In this regard, the SLM-processed CoCrFeMnNi HEA has been extensively studied to comprehensively understand the mechanisms of microstructural evolution and resulting changes in mechanical properties. In this review, recent studies on CoCrFeMnNi-type HEAs produced using SLM are discussed with respect to process-induced microstructural evolution and the relationship between hierarchical heterogeneous microstructure and mechanical properties.

The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.

The synthesis of porous W by freeze-casting and vacuum drying is investigated. Ball-milled WO3 powders and tert-butyl alcohol were used as the starting materials. The tert-butyl alcohol slurry is frozen at –25oC and dried under vacuum at –25 and –10oC. The dried bodies are hydrogen-reduced at 800oC and sintered at 1000oC. The XRD analysis shows that WO3 is completely reduced to W without any reaction phases. SEM observations reveal that the struts and pores aligned in the tert-butyl alcohol growth direction, and the change in the powder content and drying temperature affects the pore structure. Furthermore, the struts of the porous body fabricated under vacuum are thinner than those fabricated under atmospheric pressure. This behavior is explained by the growth mechanism of tert-butyl alcohol and rearrangement of the powders during solidification. These results suggest that the pore structure of a porous body can be controlled by the powder content, drying temperature, and pressure.

본 실험에서는 α-Al2O3 세라믹 중공사를 지지체로 사용하였고, 무전해 도금을 통해 Pd 및 Pd-Ag가 도금된 수소 분리막을 제조하였다. Pd-Ag 분리막은 Pd와 Ag 합금 형태로 만들기 위하여 500°C, 10 h 동안의 annealing 과정을 거쳤으며, EDS (Energy Dispersive X-ray Spectroscopy) 분석을 통해 Pd-Ag 합금이 되었다는 것을 확인하였다. 또한, SEM (Scanning Electron Microscope) 분석을 통해 제조된 Pd 및 Pd-Ag 도금층의 두께는 약 8.98, 9.29 μm으로 측정되었다. 제조된 수소 분 리막은 350~450°C, 1-4 bar의 범위에서 수소 단일 가스, 혼합가스(H2, N2)를 이용하여 수소 투과 실험을 진행하였다. 수소 단 일 가스에서 Pd와 Pd-Ag 분리막은 최대 각각 21.85, 13.76 mL/cm2⋅min의 flux를 가지며, 혼합가스에서는 450°C, 4 bar의 조건일 때, 1216, 361의 separation factor가 각각 나오는 것을 확인하였다.

본 연구에서는 용매로 침액되었을 시 전반적으로 더 균일한 상전이법 기반 평막 제조 시 주로 사용되는 부직포 지지체의 영향을 분석하였다. 도프용액의 점도가 낮을 경우 용액이 부직포층으로 쉽게 침투하여 불균일한 막이 형성되는 것 을 확인하였으며, 이를 방지하기 위해 부직포층을 유기용매로 침액하는 기법을 도입하였다. 부직포층이 유기 분리막이 생성 되는 것을 확인하였으며, 수투과 및 용매투과율도 향상하는 것을 알 수 있었다. 부직포 침액의 영향은 낮은 점도에서 확연하 게 나타났으며, 고분자용액의 점도가 높은 경우 침액 여부에 관계없이 동일한 성능을 얻을 수 있었다.

The purpose of this study was to examine the quality characteristics of byeolmijang prepared several roasted whole grain powders (oat, brown rice, black soybean, corn) for eight weeks. As the fermentation progressed, the pH decreased from 6.10~6.12 to 4.48~4.92 and the total acidity increased dramatically from 0.41~0.48% to 1.67~2.24%. There were no differences in the moisture content. The content of reducing sugar decreased, in particular, brown rice sample(C) decreased significantly than the other samples during fermentation. In color, L and b-value decreased all samples, whereas a-value showed a tendency to slightly increase. The total cell counts and lactic acid bacteria revealed an increasing tendency during fermentation. In case of the amino-type nitrogen contents, it increased significantly during the fermentation period, especially control sample (A) showed the highest content significantly. The total polyphenol of all samples increased in the fermentation period. ABTS and DPPH radical scavenging activities also increased, especially corn sample (E) had the highest levels. In by electronic tongue analysis, corn sample (E) revealed higher umami and sourness than the control. So, by adding roasted corn powder, it can enhance function and taste of byeolmijang.

This study compared and analyzed the antioxidant effect of Doenjang prepared from vegetable water, and explored the optimal addition ratio of vegetables of 5 kinds and the possibility of application to Doenjang. The sample is three kinds of vegetable water (VW1, VW2, VW3) prepared by adding different ratios of radish, carrot, green onion, onion and shiitake mushroom and Denjang prepared using it. Doenjang was aged and fermented at about 40°C for 40 days, and then separated and used only solids. The content of their antioxidant compounds was measured the content of total phenolic acid contents and total flavonoid contents. In addition, the antioxidant effect was measured by electron donating activity, SOD-like activity, ABTs radical scavenging activity and reducing power. The total phenolic acid contents and total flavonoid contents were high at VW3 and that Doenjang made with VW3. Electron donating activity and SOD-liked activity were high at VW2 and Doenjang made with VW2. ABTs radical scavenging activity was high in Doenjang made of VW3, and Reducing power was high in VW3. Therefore, if Doenjang is prepared with vegetable water prepared by properly mixing 5 types of vegetables, the possibility of developing Doenjang with high antioxidant effect was suggested.