This study was carried out to examine the physical characteristics of bacterial cellulose (BC) and its optimal culture condition using coffee by-products. Recently, recycling resources and employing eco-friendly materials have been raised as significant issues in the food industry. As the coffee industry develops, interests and efforts for recycling coffee wastes are also growing. This study attempted to confirm the production of BC by utilizing spent coffee grounds filtrate as a medium. In order to confirm the optimal culture conditions for BC production, different culture methods, initial pH, culture temperature, and culture period were examined. The optimal pH and temperature were 6.0 and 30oC, and the optimal culture period was 14 days. The cultivated BC was dried by hot air drying, freezedrying, and mold drying, respectively. Then, the properties of the BC films, such as tensile strength, elongation, water-solubility, thickness, and chromaticity were compared. The drying method affected the shape and structure of the final BC films. The production of BC film is expected to expand opportunities for recycling coffee by-products and contribute to solving environmental problems caused by food waste.

This study aims to investigate the physicochemical properties of meat analogs by using high and low moisture extrusion processes to create a plant-based analog burger patty material. The isolated soy protein blends of low- and high-meat analogs (LMMA and HMMA) were texturized using the twin-screw extruder equipped with a cooling die. The highest hardness, cohesiveness, chewiness, and cutting strength were observed in beef, but the highest stringiness was indicated in HMMA. The highest integrity index was seen in beef, while LMMA had the highest nitrogen solubility index (NSI). LMMA also had the highest water holding capacity (WHC) and water absorption capacity (WAC), whereas beef had the highest oil absorption capacity (OAC). LMMA had the highest emulsifying activity (EA) and emulsion stability (ES) in emulsifying properties. Further, the highest protein digestibility was revealed in LMMA. This study suggested that extrusion process types influence the quality of meat analog, which could be the elementary source for manufacturing the analog burger patty.

This study demonstrates the effect of the compaction pressure on the microstructure and properties of pressureless-sintered W bodies. W powders are synthesized by ultrasonic spray pyrolysis and hydrogen reduction using ammonium metatungstate hydrate as a precursor. Microstructural investigation reveals that a spherical powder in the form of agglomerated nanosized W particles is successfully synthesized. The W powder synthesized by ultrasonic spray pyrolysis exhibits a relative density of approximately 94% regardless of the compaction pressure, whereas the commercial powder exhibits a relative density of 64% under the same sintering conditions. This change in the relative density of the sintered compact can be explained by the difference in the sizes of the raw powder and the densities of the compacted green body. The grain size increases as the compaction pressure increases, and the sintered compact uniaxially pressed to 50 MPa and then isostatically pressed to 300 MPa exhibits a size of 0.71 m. The Vickers hardness of the sintered W exhibits a high value of 4.7 GPa, mainly due to grain refinement.

Aluminum alloys are extensively employed in several industries, such as automobile, aerospace, and architecture, owing to their high specific strength and electrical and thermal conductivities. However, to meet the rising industrial demands, aluminum alloys must be designed with both excellent mechanical and thermal properties. Computer-aided alloy design is emerging as a technique for developing novel alloys to overcome these trade-off properties. Thus, the development of a new experimental method for designing alloys with high-throughput confirmation is gaining focus. A new approach that rapidly manufactures aluminum alloys with different compositions is required in the alloy design process. This study proposes a combined approach to rapidly investigate the relationship between the microstructure and properties of aluminum alloys using a direct energy deposition system with a dual-nozzle metal 3D printing process. Two types of aluminum alloy powders (Al-4.99Si-1.05Cu-0.47Mg and Al-7Mg) are employed for the 3D printing-based combined method. Nine types of Al-Si-Cu-Mg alloys are manufactured using the combined method, and the relationship between their microstructures and properties is examined.

In this study, a new manufacturing process for a multilayer-clad electrical contact material is suggested. A thin and dense BCuP-5 (Cu-15Ag-5P filler metal) coating layer is fabricated on a Ag plate using a high-velocity oxygen-fuel (HVOF) process. Subsequently, the microstructure and bonding properties of the HVOF BCuP-5 coating layer are evaluated. The thickness of the HVOF BCuP-5 coating layer is determined as 34.8 μm, and the surface fluctuation is measured as approximately 3.2 μm. The microstructure of the coating layer is composed of Cu, Ag, and Cu-Ag-Cu3P ternary eutectic phases, similar to the initial BCuP-5 powder feedstock. The average hardness of the coating layer is 154.6 HV, which is confirmed to be higher than that of the conventional BCuP-5 alloy. The pull-off strength of the Ag/BCup-5 layer is determined as 21.6 MPa. Thus, the possibility of manufacturing a multilayer-clad electrical contact material using the HVOF process is also discussed.

멤브레인은 분리 기술 및 다양한 사용처에 따라서 유기물, 액체, 용질, 증기, 기체, 이온 또는 전자 등 다양한 물질 을 선택적으로 분리할 수 있다. 멤브레인은 크게 대칭막과 비대칭막으로 나누며, 기공의 유무에 따라 다공성과 비다공성으로 분류된다. 또한 멤브레인의 계면은 분자적으로 균일하거나, 또는 화학적으로 또는 물리적으로 불균일할 수 있다. 제조기술로 는 용융 압출 제조법, 연신법, 템플레이트 침출법, 트랙-에치법, 용액 캐스팅법, 상전이법 및 용액 코팅법 등이 있다. 제조된 멤브레인은 정밀여과, 한외여과, 나노여과, 역삼투, 기체분리 및 에너지 분야와 같은 다양한 응용 분야에 적용될 수 있다. 본 총설에서는 멤브레인의 분류 및 종류에 따른 제조 방법에 대한 튜토리얼을 제공한다.

Production management in the automobile parts industry is carried out according to the production plan of the customer, so it is important to prevent shortages in product supply. As the product composition became increasingly complex, the MES System was built for the purpose of efficient production plan management and inventory management, but its utilization is low. This study analyzed the problems of the MES system and sought to improve it. Through previous studies, it was confirmed that the inventory management of the pull approach that actually occurred in the warehouse is more suitable than the push approach based on the forecast of the warehouse for the volatility, complexity, and uncertainty of orders in the auto parts industry. To realize this, we tried distributed MRP by using the ADO function of VBA to link the standard information of the MES system with Excel and change the structure of the BOM table. Through this, it can help increase the accuracy of production planning and realize efficient inventory management, thereby increasing the utilization of the MES system in the auto parts industry and enhancing the competitiveness of the company.

광전기화학 성능을 향상시키기 위해 각 ZnO, ZnSe과 g-C3N4 소재의 장점을 살리도록 3성분계 적층 구조를 디자 인했다. 용액공정으로 FTO 기판위에서 ZnO 나노로드 어레이가 성장하도록 한 후 ZnO표면에 Se을 부착시켜 ZnO표면에 서 ZnSe층이 형성 되도록 이온 치환법을 도입하였다. ZnO/ZnSe 나노로드 위에 g-C3N4 층을 스핀코팅 한 후 각 층이 화 학적 접합이 되도록 질소 분위기 하에서 열처리를 하였다. AM 1.5G, 0.5 V 외부전압하에서 각 적층구조별로 광전기화학 적 전류밀도를 측정하였고 비교 결과 ZnO/ZnSe/g-C3N4 나노로드가 ZnO 및 ZnO/ZnSe 나노로드에 비하여 보다 높은 광 전류 밀도가 측정되었다. 수직 정렬된 ZnO 육각 프리즘형태는 큰 비표면적과 축 방향을 따라 전자 흐름을 원활히 하고, ZnSe 층은 비표면적과 광흡수 범위를 더욱 넗히는 효과를 가져왔다. 이로 인하여 ZnO/ZnSe/g-C3N4 삼원 접합 전극의 향상된 성능은 가시광선 흡수범위 확장, 전하 분리 강화 및 전자 전도도 향상으로 인한 시너지 효과에 기인되는 것으로 판단된다.

It was legislated in Korea that the small-sized enterprise with fewer than 50 employees should appoint at least one managing officer in order to improve safety and health of the employees since 2016. Study on the effectiveness of this legislation is hardly found, however. This study tried to evaluate effectiveness of the regulations for appointing the safety and health management officer in small-sized manufacturing companies and make suggestions to improve it. It was done by pairwise comparison between the level of safety and health achievement of 52 companies before and after the legislation. A scorecard system and questionnaires were devised for assessing the level of safety and health achievement and surveying awareness and practice of the regulation in the field. Results from quantitative and qualitative analyses performed in the study confirm that the safety and health achievement score has increased significantly after appointing the managing officer. It is also revealed that the lack of expertise and motivation of the appointed officer would yield pointless outcomes. Recommendations to make it better the effectiveness of the regulation are: to administrate requirements more strictly to be appointed as a safety and health management officer, to revise the curriculum to train the expertise of the appointed officers, and to expand financial support of the government to settle the safety and health management system.

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.