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        검색결과 4,564

        182.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oysters are the most widely produced shellfish culture in Korea and 90% of their weight. Main component of oyster shell is CaCO3 and an appropriate calcination temperature was derived using thermo-gravimetric analysis. The difference in components for each calcination temperature was confirmed and the adsorbent was manufactured by activation. The oyster shell adsorbent surface area was 5.72m2/g with pores in the mesopore range. The adsorption amount was 37.44 mg/g. Therefore, the possibility of using oyster shell as an adsorbent was confirmed.
        4,000원
        183.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국의 전통 과자인 유과는 거의 모든 공정이 수작업으로 제조되기 때문에 공정 중 작업자 및 작업도구 등에 의한 교차오염으로 인한 안전문제가 제기되고 있다. 본 연구에서는 유과 제조 공정 중 찹쌀의 불림 단계에서 증가된 미생물을 제어하기 위하여 항균 활성이 있는 용액 9가지 용액(40% 자몽종자 추출물, 100% 계피 추출물, 70% 에탄올, 100% 식초, 0.2% 차아염소산나트륨, 40% 초산나트륨, 40% 탄산수소나트륨, 40% 사과산, 40% 구연산)을 이용하여 Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, Bacillus cereus에 대해 항균 효과를 비교 확인하였다. Disk diffusion법을 통해 40% 사과산과 구연산에서 높은 항균 효과를 확인할 수 있었고, 추가로 항균용액의 농도, 처리방법 및 시간을 최적화한 결과 1% 사과산-구연산을 10분 동안 처리 시 세균 5종을 모두 사멸시켜 높은 항균효과를 확인할 수 있었다. 불림단계의 찹쌀에 1% 사과산-구연산으로 정치 및 교반하면서 10분 동안 세척하였을 때 일반세균과 대장균군의 수가 각각 4.0 Log CFU/g와 5.0 Log CFU/g씩 감소하였다. 이상의 결과로 볼 때 1% 사과산-구연산으로 불린 찹쌀에 대해 침지와 교반으로 10분 동안 처리함으로써 전통 유과 제조과정 중 쌀의 불림단계에서 증가된 미생물을 효과적으로 저감화 할 수 있음을 확인하였다.
        4,000원
        184.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 글로벌 정치․경제 환경의 대전환으로 미국과 유럽 국가들은‘재산업화 전략’으로 제조업 회복을 추진하고 있고, 중국도 ‘중국제조 2025’를 통해 제조업의 질적 발전과 고도화에 집중하고 있다. 이러한 상황에서 본 연구는 외국인직접투자(Inward Foreign Direct Investment, IFDI)가 중국 제조업 고도화에 미치는 영향에 대해 실 증적 분석을 통해 검증해 보고자 하였다. 제조업 가운데 첨단기술 산업의 비중을 중국 제조업 고도화의 지표로 이용하여 2004년부터 2020년까지의 17개년도 중국 31개 성(省)별 패널데이터로 고정효과 모형과 FGLS 모형 을 활용하여 실증분석을 하였다. 분석 결과, 중국 전체와 중국의 동부, 중부, 동북 지역, 장강경제벨트는 IFDI가 중국 제조업 고도화에 긍정적인 영향을 미치는 것으로 나타났지만, 서부지역에 대해서는 영향을 미치지 않는 것 으로 나타났다. 이러한 결과를 통해 IFDI가 중국 제조업 고도화에 미치는 영향은 지역별로 다소 차이가 존재 하고 있음을 입증하였다. 분석 결과는 중국 정부의 IFDI를 통한 지역 균형 발전정책이 중부와 동북 지역에 대 해서는 효과적이었음을 알 수 있었던 반면 중국 서부지역에 대해서는 IFDI를 통한 첨단기술 산업 고도화의 정 책 목표와 전략을 수정할 필요가 있음을 시사한다. 한편 통제변수로 활용된 변수인 수출과 수입으로 측정된 개 방정도와 첨단기술에 대한 연구개발 투자는 제조업 고도화에 매우 긍정적인 영향을 미치는 것으로 일관되게 나 타나고 있다.
        5,500원
        185.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to develop and evaluate amorphous spray-dried microparticles (SDM) containing levosulpiride to increase its solubility. SDM are prepared via solvent evaporation using polyvinylpyrrolidone (PVP) as the water-soluble polymer and Cremophor RH40 as the surfactant. The SDM is prepared by varying the amounts of PVP and Cremophor RH40, and its physicochemical properties, solubility, and dissolution are confirmed. All levosulpiride-loaded SDMs converted the crystalline drug into an amorphous form, significantly improving drug solubility and dissolution compared with the drug alone. SDM consisting of drug/PVP/Cremophor RH40 in a weight ratio of 5:10:3, with increased solubility (720 ± 36 vs. 1822 ± 51 μg/mL) and dissolution rate (10.3 ± 2.2 vs. 92.6 ± 6.0%) compared with drug alone, shows potential as a commercial drug for improved oral bioavailability of levosulpiride.
        4,000원
        186.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, an Al82Ni7Co3Y8 (at%) bulk metallic glass is fabricated using gas-atomized Al82Ni7Co3Y8 metallic glass powder and subsequent spark plasma sintering (SPS). The effect of powder size on the consolidation of bulk metallic glass is considered by dividing it into 5 m or less and 20–45 m. The sintered Al82Ni7Co3Y8 bulk metallic glasses exhibit crystallization behavior and crystallization enthalpy similar to those of the Al82Ni7Co3Y8 powder with 5 m or less and it is confirmed that no crystallization occurred during the sintering process. From these results, we conclude that the Z-position-controlled spark plasma sintering process, using superplastic deformation by viscous flow in the supercooled liquid-phase region of amorphous powder, is an effective process for manufacturing bulk metallic glass.
        4,000원
        187.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a graphite block is fabricated using artificial graphite processing byproduct and phenolic resin as raw materials. Mechanical and electrical property changes are confirmed due to the preforming method. After fabricating preforms at 50, 100, and 150 MPa, CIP molding at 150 MPa is followed by heat treatment to prepare a graphite block. 150UP-CIP shows a 12.9% reduction in porosity compared with the 150 MPa preform. As the porosity is decreased, the bulk density, flexural strength, and shore hardness are increased by 14.9%, 102.4%, and 13.7%, respectively; and the deviation of density and electrical resistivity are decreased by 51.9% and 34.1%, respectively. Therefore, as the preforming pressure increases, the porosity decreases, and the electrical and mechanical properties improve.
        4,000원
        188.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The global demand for raw lithium materials is rapidly increasing, accompanied by the demand for lithiumion batteries for next-generation mobility. The batch-type method, which selectively separates and concentrates lithium from seawater rich in reserves, could be an alternative to mining, which is limited owing to low extraction rates. Therefore, research on selectively separating and concentrating lithium using an electrodialysis technique, which is reported to have a recovery rate 100 times faster than the conventional methods, is actively being conducted. In this study, a lithium ion selective membrane is prepared using lithium lanthanum titanate, an oxide-based solid electrolyte material, to extract lithium from seawater, and a large-area membrane manufacturing process is conducted to extract a large amount of lithium per unit time. Through the developed manufacturing process, a large-area membrane with a diameter of approximately 20 mm and relative density of 96% or more is manufactured. The lithium extraction behavior from seawater is predicted by measuring the ionic conductivity of the membrane through electrochemical analysis.
        4,000원
        189.
        2023.02 구독 인증기관 무료, 개인회원 유료
        3,000원
        190.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A turbo engine is used to improve engine volumetric efficiency by using the energy of exhaust gas with a device such as a turbocharger. Recently, it has been attracting attention as a solution for responding to environmental issues such as exhaust gas regulation, and its use is being expanded to gasoline and CNG engines as well as diesel engines. However, as electric and hydrogen vehicles enter the automotive market more rapidly, traditional turbo engines also confront many challenges. In this paper, to examine the current status and prospects of the turbo engine, we analyze the related patents in the turbo engine field applied to patent offices in seven major countries, including Korea, USA, China, Japan, Germany, France, and the European Union Patent Office, and analyze the patent application trend. Using ‘the pie’ system of Korea Institute of Science and Technology Information (KISTI), family patents were refined, patent application trends were diagnosed, and the technology and market competitiveness of major applicants were compared and analyzed. Even within the turbo engine market, where traditional automakers and turbocharger manufacturer participate, it was possible to examine the dynamic changes in the market through the analysis of technology and market competitiveness. The main companies leading the technology and market aspects and the companies specialized in the technology and market aspects were observed.
        4,000원
        191.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, as interest in safe food and ingredient content has increased, the demand for highly concentrated health functional food that can be manufactured at home is increasing. Accordingly, in this study, we developed a galenic maker that can increase the extraction efficiency of herbal medicine(ginseng) ingredients and shorten the manufacturing time. After verifying the safety of the designed components through structural analysis and thermal flow analysis, the dimensions and shape of the galenic maker were determined. A prototype was produced based on the design process and the performance of the product was verified through extraction efficiency and ingredient analysis.
        4,000원
        192.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There is a considerable amount of research on metal material product worker’s hearing loss caused by noise that comes from manufacturing process. A further investigation that characterizes the sound that comes from manufacturing process of metal material products. however. To do this, a noise management plan is needed. It should include a generated sound process from the main sources of disturbance at manufacturing process areas. And a soundproof measurement will identify the amount of noise reduction needed for a hearing-safe working environment. Finally, researchers in this study measured tests on the noise and the vibration process, and the noise caused by operations allowed for an investigation on the suitability of certain environmental conditions. Noise-related programs can be used to predict the noise distribution of the noise level characteristic. This can help identify and reduce the presence of sound interference through sound proofing measures.
        4,000원
        193.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ion-beam irradiation(IB) on HfO2 surface induced high-performance liquidcrystal(LC) driving at a 1-V threshold with vertical alignment of liquid crystals(LC). The high-k materials Atomic layer deposition was used to obtain LC orientation on ultra thin and high-quality films of HfO2 layers. To analyze surface morphological transition of HfO2 which can act as physic alignment effect of LC, atomic force micro scopy images are employed with various IB intensities. The contact angle was measured to elucidate the mechanism of vertical alignment of LC on HfO2 with IB irradiation. Contact angle measurements show the surface energy changes via IB intensity increasing.
        4,000원
        194.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigate the austenite stability in nanocrystalline Fe-7%Mn-X%Mo (X = 0, 1, and 2) alloys fabricated by spark plasma sintering. Mo is known as a ferrite stabilizing element, whereas Mn is an austenite stabilizing element, and many studies have focused on the effect of Mn addition on austenite stability. Herein, the volume fraction of austenite in nanocrystalline Fe-7%Mn alloys with different Mo contents is measured using X-ray diffraction. Using a disk compressive test, austenite in Fe–Mn–Mo alloys is confirmed to transform into strain-induced martensite during plastic deformation by a disk d. The variation in austenite stability in response to the addition of Mo is quantitatively evaluated by comparing the k-parameters of the kinetic equation for the strain-induced martensite transformation.
        4,000원
        195.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to assess the impact of spray drying conditions on medium-chain triglyceride (MCT) loading, solubility, and release of an MCT-loaded solid self-emulsifying system in a water-insoluble oily substance. MCT-loaded solid self-emulsifying systems are prepared by spray drying with SDS and calcium silicate. The effects of inlet temperature (60, 80, or 100oC) and feed solution composition (0, 10, 50, 90, or 100% ethanol) on physicochemical properties of MCT-loaded solid self-emulsifying systems are studied. The inlet temperature significantly affects the water solubility of MCT. Moreover, the feed solution composition significantly affects water solubility, release rate, and MCT loading. The MCT-loaded solid self-emulsifying system obtained at 60oC using 90% ethanol feed solution shows the best physicochemical properties among the synthesized products and exhibits better water solubility (4.43 ± 0.44 vs. 0 μg/mL) and release (94.4 ± 1.6 vs. 32.8 ± 7.4%, 60 min) than a commercial product. Furthermore, the MCT-loaded solid self-emulsifying system shows an excellent emulsion droplet size (approximately 230 nm).
        4,000원
        196.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        N-doped Na2Ti6O13@TiO2 (denoted as N-NTO@TiO2) composites are successfully synthesized using a simple two-step process: 1) ball-milling of TiO2 with Na2CO3 followed by heat treatment at 900oC; 2) mixing of the prepared Na2Ti6O13 with titanium isopropoxide and calcining with urea at 500oC. The prepared composites are characterized using XRD, SEM, TEM, FTIR, and BET. The N-NTO@TiO2 composites exhibit well-defined crystalline and anatase TiO2 with exposed {101} facets on the external surface. Moreover, dopant N atoms are uniformly distributed over a relatively large area in the lattice of the composites. Under visible light irradiation, ~51% of the aqueous methylene blue is photodegraded by N-NTO@TiO2 composites, which is higher than the values shown by other samples because of the coupling effects of the hybridization of NTO and TiO2, N-doping, and presence of anatase TiO2 with exposed {101} facets.
        4,000원
        197.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lithium lanthanum titanium oxide (LLTO) is a promising ceramic electrolyte because of its high ionic conductivity at room temperature, low electrical conductivity, and outstanding physical properties. Several routes for the synthesis of bulk LLTO are known, in particular, solid-state synthesis and sol-gel method. However, the extremely low ionic conductivity of LLTO at grain boundaries is one of the major problems for practical applications. To diminish the grain boundary effect, the structure of LLTO is tuned to nanoscale morphology with structures of different dimensionalities (0D spheres, and 1D tubes and wires); this strategy has great potential to enhance the ion conduction by intensifying Li diffusion and minimizing the grain boundary resistance. Therefore, in this work, 0D spherical LLTO is synthesized using ultrasonic spray pyrolysis (USP). The USP method primarily yields spherical particles from the droplets generated by ultrasonic waves passed through several heating zones. LLTO is synthesized using USP, and the effects of each precursor and their mechanisms as well as synthesis parameters are analyzed and discussed to optimize the synthesis. The phase structure of the obtained materials is analyzed using X-ray diffraction, and their morphology and particle size are analyzed using field-emission scanning electron microscopy.
        4,000원
        198.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Thermal protection systems (TPS) are a group of materials that are indispensable for protecting spacecraft from the aerodynamic heating occurring during entry into an atmosphere. Among candidate materials for TPS, ceramic insulation materials are usually considered for reusable TPS. In this study, ceramic insulation materials, such as alumina enhanced thermal barrier (AETB), are fabricated via typical ceramic processing from ceramic fiber and additives. Mixtures of silica and alumina fibers are used as raw materials, with the addition of B4C to bind fibers together. Reaction-cured glass is also added on top of AETB to induce water-proof functionality or high emissivity. Some issues, such as the elimination of clumps in the AETB, and processing difficulties in the production of reusable surface insulation are reported as well.
        4,000원
        199.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop an optimal processing method for the production of apple-mango jelly for domestic suppliers, by analyzing the quality attributes of the jelly. According to the central composite design, a total of 11 experimental points were designed including the content of apple-mango juice (X1), and the sugar content (X2). The responses were analyzed including the color values (CIE Lab and color difference), physicochemical properties (water activity, sweetness, pH, and total acidity), and textural properties (hardness and gel strength). Regression analysis was conducted, except for total acidity, and showed no significant difference for all the experimental points (p<0.05). Quadratic model was derived for all responses with an R square value ranging from 0.8590 to 0.9978. Based on regression model, the appropriate mixing ratio of apple-mango jelly was found to be 31.11% of apple mango juice and 14.65% of sugar. Through this study, the possibility for developing jelly product using apple-mango was confirmed, and it is expected that these findings will contribute to the improvement of the agricultural industry.
        4,000원
        200.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Starfish are creatures that destroy marine ecosystems due to their high reproductive rate and predatory nature. Instead of mass incineration, this study attempted to utilize them as functional adsorbents to control odorous organic compounds. This waste starfishbased adsorbent showed a high aldehyde capture efficiency of 91.1%. The maximum specific surface area of the prepared waste starfish adsorbent was 2.19m2/g, and the adsorption amount was 101.66mg/g. Therefore, it was confirmed that the waste starfish had the ability to perform well as an adsorbent.
        4,000원