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        검색결과 4,540

        101.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transition metal chalcogenides are promising cathode materials for next-generation battery systems, particularly sodium-ion batteries. Ni3Co6S8-pitch-derived carbon composite microspheres with a yolk-shell structure (Ni3Co6S8@C-YS) were synthesized through a three-step process: spray pyrolysis, pitch coating, and post-heat treatment process. Ni3Co6S8@C-YS exhibited an impressive reversible capacity of 525.2 mA h g-1 at a current density of 0.5 A g-1 over 50 cycles when employed as an anode material for sodium-ion batteries. However, Ni3Co6S8 yolk shell nanopowder (Ni3Co6S8-YS) without pitch-derived carbon demonstrated a continuous decrease in capacity during charging and discharging. The superior sodium-ion storage properties of Ni3Co6S8@C-YS were attributed to the pitchderived carbon, which effectively adjusted the size and distribution of nanocrystals. The carbon-coated yolk-shell microspheres proposed here hold potential for various metal chalcogenide compounds and can be applied to various fields, including the energy storage field.
        4,000원
        102.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the government has provided support such as entering new markets, expanding sales channels, and supporting manpower, not just in the form of funding, to efficiently and effectively support limited national resources to improve corporate performance. In this study, we tried to find out the effect of government support for companies that have benefited from the Excellent Technology Research Center Project (ATC Project) and the World Class 300 project using propensity score matching. As a result of the analysis, the effect of government support for the ATC project became visible after the appointment period, while the effect of the World Class 300 project was insignificant. This means that when the size of the company is small, the effect of government support is more pronounced. This suggests that in order to maximize the effectiveness of government support, appropriate national policy interventions such as government innovation funding are needed when the size of the company is small. In this study, differences in the timing, performance indicators, and company size of policy support effects were found in the growth stage of a company from a mid- to long-term time series perspective, suggesting that support policies based on this need to be adjusted and redesigned.
        4,300원
        105.
        2023.09 구독 인증기관 무료, 개인회원 유료
        3,000원
        106.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, as ESG management has become an important issue, major companies in the automotive parts manufacturing industry are conducting ESG evaluations of their suppliers for the purpose of supply chain management. The results of these evaluations are being incorporated into contractual agreements. However, many small and medium-sized enterprises(SMEs) are lacking in their capacity and resources to effectively respond to ESG evaluations. Furthermore, existing ESG management guidelines do not provide an industry-specific guidance, making it necessary to establish industry-specific guidelines that SMEs can refer to. Therefore, in this study, the evaluation Indicators of ESG supply chain assessments are surveyed, which is conducted by domestic major automotive parts companies and global automobile manufacturers. Then 56 supply chain ESG evaluation Indicators are derived. Also, ESG management indicators for SMEs is analyzed through the Importance-Performance Analysis(IPA), based on an interview of expert groups. Therefore, this study could propose industry-specific ESG guidelines, based on the results of the derived indicators, which reflects the need for SMEs to practice ESG management within certain boundaries.
        4,300원
        107.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates the melting point and brazing properties of the aluminum (Al)-copper (Cu)-silicon (Si)-tin (Sn) alloy fabricated for low-temperature brazing based on the alloy design. Specifically, the Al-20Cu-10Si-Sn alloy is examined and confirmed to possess a melting point of approximately 520oC. Analysis of the melting point of the alloy based on composition reveals that the melting temperature tends to decrease with increasing Cu and Si content, along with a corresponding decrease as the Sn content rises. This study verifies that the Al-20Cu-10Si-5Sn alloy exhibits high liquidity and favorable mechanical properties for brazing through the joint gap filling test and Vickers hardness measurements. Additionally, a powder fabricated using the Al-20Cu-10Si-5Sn alloy demonstrates a melting point of around 515oC following melting point analysis. Consequently, it is deemed highly suitable for use as a low-temperature Al brazing material.
        4,000원
        108.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to prepare a colloidal silica-containing powder to enhance the solubility and dissolution rate of rivaroxaban using a self-nanoemulsifying drug delivery system (SNEDDS). We investigate the impact of colloidal silica on a nanoemulsion system for preparing powdered SNEDDS. The liquid SNEDDS comprises 30/20/50 (w/w/w) Peceol/ Cremophor RH40/Tween 80, which results in the formation of the smallest droplets. Three powdered SNEDDS formulations are prepared by suspending the liquid SNEDDS formulation using colloidal silica and spray drying. The powdered SNEDDS prepared with liquid SNEDDS and colloidal silica at a ratio of 1/0.5 (w/w) exhibits the highest water solubility (0.94 ± 0.62 vs. 26.70 ± 1.81 μg/mL) and dissolution rate (38.4 ± 3.6 vs. 85.5 ± 3.4%, 45 min) when compared to the drug alone. Morphologically, the liquid SNEDDS is adsorbed onto colloidal silica and forms smaller particles. In conclusion, an SNEDDS containing rivaroxaban, prepared using colloidal silica, facilitates the creation of a nanoemulsion and enhances the water solubility of rivaroxaban. Accordingly, this technology holds significant potential for commercialization.
        4,000원
        109.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Physicochemical properties and storage stability of plant-based alternative meat prepared with low-fat soybean powder (LPAM) treated by supercritical-CO2 and those of full-fat soybean powder (FPAM) were compared. Ash and crude protein contents were higher in LPAM than in FRAM. Water absorption capacity and oil absorption capacity were significantly higher in LPAM than in FPAM. Water binding capacity was higher in LPAM than in FPAM during a 20 days storage period at 5℃ and pH was significantly lower in LPAM than in FPAM after a 5~10 days storage period. Hardness, gumminess and chewiness significantly increased with the increase in the storage period, and the three were significantly higher in LPAM than in FPAM after 10 days and 20 days of storage. The acid value showed no remarkable difference according to the storage period in LPAM; however, it was significantly higher in FPAM than in LPAM after 20 days of storage. The peroxide value and TBA value were significantly increased according to the storage period, and were significantly lower iin LPAM than in FPAM during all the storage periods. Therefore, the use of low-fat soybean powder may be effective in improving oxidative stability during storage in the production of plant-based alternative meat.
        4,000원
        110.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study measured the quality characteristics of Yulmu-added kimchi with different manufacturing methods to present primary data for the food development of kimchi and the optimal Yulmu manufacturing method. pH, salinity, and soluble solids tended to decrease during the storage period in all sample groups. The chromaticity differed depending on the mixing ratio of the material, and WYS showed the highest values for all L, a, and b values. Total polyphenol content and ABTS free radical scavenging activity were higher in the Yulmu-added sample groups than in the control group. Citric acid was reduced in range in the control group and all sample groups during the storage period, and lactic acid tended to increase in content in all sample groups. The dietary fiber content was higher in the Yulmu-added sample group than in the control group during storage. As a result, it was found that Yulmu-added kimchi had higher total phenol content, antioxidant properties, and dietary fiber content than the control group. YFF, YF, and WYF were found to be excellent, confirming their nutritional value, and are considered suitable for developing healthy and functional food materials for kimchi.
        4,000원
        111.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 중공사형 지지체막을 폴리술폰(polysulfone, PSf) 고분자를 이용하여 비용매 상분리법(non solvent induced phase separation, NIPS)에 의해 제조하였다. 제조된 중공사 지지체막을 PDMS와 Pebax를 코팅하여 중공사형 복합막 을 제조하고 CO2, H2, O2 그리고 N2에 대한 순수 투과도(permeance)와 선택도를 측정하였다. 제조된 복합막 모듈 중에서 선 택도(CO2/H2)가 가장 높은 모듈을 선정하여 모사가스를 사용하여 스테이지컷(stage cut, SC)의 변화에 따라 분리성능을 측정 하였다. 이때 사용된 모사가스는 PSA에서 버려지는 off gas의 농도인 CO2 70% : H2 30%인 것을 사용하였다. 1단 실험에서 는 H2 농도 약 60%, H2 회수율 12%의 값을 얻을 수 있었다. 낮은 H2 농도와 회수율을 극복하기 위해 2단 직렬 테스트를 수 행하였으며, 이를 통해 H2 농도 약 70%, H2 회수율 70%를 달성할 수 있었으며, 이를 통해 CO2/H2 분리에 대하여 분리 공정 구성을 도출할 수 있었다.
        4,200원
        112.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 에너지 저장 응용을 위한 PVI-PGMA/LiTFSI 고분자 막 전해질 및 CxNy-C 유연 전극의 합성 및 특성 에 관한 연구이다. 이중 기능을 갖는 PVI-PGMA 공중합체는 우수한 이온 전도성을 나타내었으며, PVI-GMA73/LiTFSI200 막 전해질은 1.0 × 10-3 S cm-1의 최고 전도도를 달성하였다. CxNy-C 전극의 전기화학적 성능을 체계적으로 분석하였으며, C3N2-C는 나노와이어와 다면체로 구성된 높은 연결성을 갖는 하이브리드 구조와 이중 Co/Ni 산화물을 포함하여 풍부한 산 화환원 활성 부위와 이온 확산을 용이하게 하는 특징으로 인해 958 F g-1의 최고용량 및 최소한의 전하 전달 저항(Rct)을 달성 하였다. 흑연 탄소 껍질의 존재는 충전-방전 동안 높은 전기화학적 안정성에 기여하였다. 이러한 결과들은 고성능 에너지 저 장 장치인 슈퍼커패시터 및 리튬 이온 전지와 같은 첨단 에너지 저장 장비에 PVI-PGMA/LiTFSI 고분자 막 전해질과 CxNy-C 전극을 활용하는 잠재력을 보여주었으며, 지속 가능하고 고성능의 에너지 저장 기술을 더욱 발전시키는 길을 열어가 고 있다.
        4,200원
        113.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기업의 기술혁신이 고용과 기업성과에 미치는 영향을 변수 간 양방향 인과관계를 고려하여 분석하였다. 기술혁신의 대리변수는 기업의 특허출원 수이며, 분석대상은 100인 이상 규모의 국내 제조업체이다. 실증분석의 경우 기술혁신(특허출원), 고용(근로자 수, 숙련 근로자 비중), 기업성과(근로자 1인당 매출액)가 종속변수인 연립방정식 모형을 3단계 최소자승추정법(3SLS)으로 추정하였다. 외생변수로 기업의 경영상 특성과 일반적 특성을 통제하였고, 각 방정식의 식별변수로 R&D집약도, 근로자 1인당 노동비용(또는 기업부설연구소 보유 여부), 교육훈련투자를 사용하였다. 분석자료는 인적자본기업패널(HCCP)의 1차년도(2005년) ∼7차년도(2017년) 자료이며, 이를 NICE신용평가정보(주)의 기업 재무자료 및 한국 특허청의 특허정보와 병합하여 사용하였다. 분석결과에 의하면, 기업의 특허출원이 활발할수록 근로자 수, 숙련 근로자 비중, 근로자 1인당 매출액이 모두 증가하였고, 반대 방향의 인과관계도 모두 유의 하였다. 따라서 기업의 기술혁신은 고용의 확대 및 질적 제고뿐 아니라 기업의 지속적인 성장에도 기여하는 것으로 확인된다.
        7,700원
        114.
        2023.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.
        4,000원
        115.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of flow analysis is to develop a simple CFD analysis model to develop a heat transfer analysis model including transient heat transfer characteristics, especially phase change, of thin film evaporators. The simple analytical model focuses on the evaporation phase change. To reduce the computational cost, the shape was simplified to two dimensions, and the simulation time was set short with a focus on simulating the phase change phenomenon. In the future, based on this analysis model, we will develop an analysis model for simulating not only vaporization but also liquefaction, that is, transient distillation phenomenon, according to the shape of the thin film distillation device.
        4,000원
        116.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The demand for energy is steadily rising because of rapid population growth and improvements in living standards. Consequently, extensive research is being conducted worldwide to enhance the energy supply. Transpiration power generation technology utilizes the vast availability of water, which encompasses more than 70% of the Earth's surface, offering the unique advantage of minimal temporal and spatial constraints over other forms of power generation. Various principles are involved in water-based energy harvesting. In this study, we focused on explaining the generation of energy through the streaming potential within the generator component. The generator was fabricated using sugar cubes, PDMS, carbon black, CTAB, and DI water. In addition, a straightforward and rapid manufacturing method for the generator was proposed. The PDMS generator developed in this study exhibits high performance with a voltage of 29.6 mV and a current of 8.29 μA and can generate power for over 40h. This study contributes to the future development of generators that can achieve high performance and long-term power generation.
        4,000원
        117.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Boron carbide (B4C) is highly significant in the production of lightweight protective materials when added to aluminum owing to its exceptional mechanical properties. In this study, a method for fabricating Al-B4C composites using high-energy ball milling and directed energy deposition (DED) is presented. Al-4 wt.% B4C composites were fabricated under 21 different laser conditions to analyze the microstructure and mechanical properties at different values of laser power and scan speeds. The composites fabricated at a laser power of 600 W and the same scan speed exhibited the highest hardness and generated the fewest pores. In contrast, the composites fabricated at a laser power of 1000 W exhibited the lowest hardness and generated a significant number of large pores. This can be explained by the influence of the microstructure on the energy density at different values of laser power.
        4,000원
        118.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aluminum alloys are widely utilized in diverse industries, such as automobiles, aerospace, and architecture, owing to their high specific strength and resistance to oxidation. However, to meet the increasing demands of the industry, it is necessary to design new aluminum alloys with excellent properties. Thus, a new method is required to efficiently test additively manufactured aluminum alloys with various compositions within a short period during the alloy design process. In this study, a combinatory approach using a direct energy deposition system for metal 3D printing process with a dual feeder was employed. Two types of aluminum alloy powders, namely Al6061 and Al-12Cu, were utilized for the combinatory test conducted through 3D printing. Twelve types of Al-Si-Cu-Mg alloys were manufactured during this combinatory test, and the relationship between their microstructures and properties was investigated.
        4,000원
        119.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we evaluated the effects of acid leaching on the properties of Cr powder synthesized using self-propagating high-temperature synthesis (SHS). Cr powder was synthesized from a mixture of Cr2O3 and magnesium (Mg) powders using the SHS Process, and the byproducts after the reaction were removed using acid leaching. The properties of the recovered Cr powder were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), particle size analysis (PSA), and oxygen content analysis. The results show that perfect selective leaching of Cr is challenging because of various factors such as incomplete reaction, reaction kinetics, the presence of impurities, and incompatibility between the acid and metal mixture. Therefore, this study provides essential information on the properties under acidic conditions during the production of high-quality Cr powder using a self-propagating high-temperature synthesis method.
        4,000원
        120.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.
        4,000원