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        검색결과 65

        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is concerned with the optimization of the manufacturing process of a hot water extract containing antioxidant activity from Lycium barbarum, traditionally known to have various physiological activities. For the establishment of the optimization process, the central composite design of response surface methodology(RSM) was used. Thirteen extraction processes were performed by encoding the independent variables, extraction temperature (65.9oC–94.1oC) and extraction time (2.59 hr–5.41 hr). As a result of the experiment, the optimal manufacturing conditions for the extract were 340.0 mg/100 g of GAE at an extraction temperature of 94.1oC and an extraction time of 5 hr. The maximum yield of flavonoids was 22.44 mg/100 g of HES at an extraction temperature of 94.1oC and an extraction time of 4 hr. The conditions for producing the extract with the maximum antioxidant capacity (DPPH 92.12%) were 90oC and 4.5 hr extraction time. Therefore, the optimal manufacturing process conditions for extracts containing total phenol content, flavonoid content, and DPPH radical scavenging activity, which are dependent variables, were extraction temperature of 90-95oC and extraction time of 4 hr, which were not significantly different from the actual values. Therefore, Lycium barbarum extract rich in total phenol and flavonoid content related to antioxidant function is expected to be used as a functional food and cosmetic material.
        4,000원
        5.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study presents the synthesis, characterization, and utilization of marine macroalgae-derived bio-carbon catalysts (BC and KOH-AC) for the efficient conversion of waste cooking oil (WCO) into biodiesel. The biochar (BC) was produced through slow pyrolysis of macroalgal biomass, which was subsequently activated with potassium hydroxide (KOH) to produce a KOH-modified activated carbon (KOH-AC) catalyst. Advanced characterization techniques, including SEM, EDX, XRD, FTIR, and TGA, were used to examine the physicochemical characteristics of the catalysts. The synthesized catalysts were utilized to produce biodiesel from WCO, and the results revealed that the highest biodiesel yields, 98.96%, and 47.54%, were obtained using KOH-AC and BC catalysts, respectively, under optimal reaction conditions of 66 °C temperature, 12.3 M/O molar ratio, 130 min time, and 3.08 wt.% catalyst loading via RSM optimization. The kinetic and thermodynamic parameters, such as k, Ea, ΔH, ΔS, and ΔG, were determined to be 0.0346 min− 1, 43.31 kJ mol− 1, 38.98 kJ mol− 1, − 158.38 J K− 1 mol− 1, and 92.58 kJ mol− 1, respectively. The KOH-AC catalyst was recycled up to five times, with a significant biodiesel yield of 80.37%. The fuel properties of the biodiesel met ASTM (D6751) specifications, ensuring that it has excellent fuel characteristics and can be used as an alternative fuel.
        5,500원
        6.
        2023.10 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (Bt) is currently the most commonly used microbial pesticide. In the previous study, Bt IMBL-B9 known for its high toxicity against Spodoptera exigua, S. frugiperda and Plutella xylostella was characterized. To develop novel biopesticide, optimization of culture medium is required for the cost-effective mass production for toxin production of IMBL-B9. Through experimental design by Plackett-Burman design, ingredients that significantly influenced the production of IMBL-B9's toxin were selected. Using these results, the novel culture medium for IMBL-B9 was developed and the toxin yield of IMBL-B9 was significantly increased than conventional media by using this medium. These results could be useful for the development of biopesticides.
        7.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Microbial proteases are more economical than plant- and animal-derived proteases due to their ease of production and high activity. This study aimed to optimize the production of proteases from fermentative food-derived microorganisms. Five strains with proteolytic activity among 50 Bacillus sp. were first screened. Two strains with high protease activity were identified: Bacillus amyloliquefaciens SRCM 102139 and Bacillus subtilis SRCM 104999. SRCM 102139 strain and SRCM 104999 strain had the highest protease activity in 0.8% glucose and 0.3% yeast extract, and in 0.8% starch and 0.1% soy peptone, respectively. The production of protease for two strains was optimized by the Central Composite Design (CCD) under response surface methodology. The optimal conditions for protease production in SRCM 102139 were 0.5% and 0.347%, pH 6.0, for carbon (glucose) and nitrogen (yeast extract springer 0202) sources, respectively, with a predicted value of 0.929 U/mL. Additionally, the optimal conditions for protease production in SRCM 104999 were 0.5% and 0.5%, pH 6.7, for carbon (starch) and nitrogen (soy peptone HSP-349) sources, respectively, with a predicted value of 0.431 U/mL. The actual protease activities of SRCM 102139 and SRCM 104999 under the established conditions were 0.926 U/mL and 0.428 U/mL, respectively, closely matching the predicted values.
        4,200원
        8.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, graphene oxide (GO) was synthesized by the improved Hummers’ method. The degree of oxidation from graphite (Gi) to GO was determined through interlayer spacing calculated from X–ray diffraction. Besides, the effect of KMnO4: Gi ratios (X1), H2SO4 volume (X2), oxidation temperature (X3), oxidation time of stage 1 (X4), and oxidation time of stage 2 (X5) was screened by the Plackett–Burman model. The simultaneous impact of three factors that influenced the degree of oxidation (X1, X2, and X3) was studied by the Box–Behnken experimental model of response surface methodology to achieve suitable conditions for the GO synthesis process. The characterization of GO product was investigated via the modern analytical methods: X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, UV–Vis spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Inaddition, the study was also carried out on a pilot scale for orientation in industrial application with the yield of 14 g/batch.
        4,300원
        9.
        2022.10 구독 인증기관·개인회원 무료
        Interests in molten salt reactor (MSR) using a fast spectrum (FS) have been increased not only for having a high power density but for burning the high-level waste generated from nuclear power plants. For developing the FS-MSR technologies, chloride-based fuels are considered due to the advantage of higher solubility of actinides and lanthanides over fluoride-based salts. Despite significant progress in development of MSR technology, the manufacturing technology for production of the fuel is still insufficiently understood. One of the option to prepare the MSR fuel is to use products from pyroprocessing where oxide form of spent nuclear fuel is reduced into metal form and useful elements can be collected via electrochemical methods in molten salt system at high temperature. In order to chlorinate the products into chloride form, previous study used NH4Cl to chlorinate U metal into UCl3 in an airtight reactor. It was found that the U metal was completely chlorinated into chloride forms; however, impurities generated by the reaction of NH4Cl and reactor wall were found in the product. Therefore, in this work, the air tight reactor was re-deigned to avoid the reaction of reactor wall by insertion of Al2O3 crucible inside of the reactor. In addition, the reactor size was increased to produce UCl3 over 100 g. Using the newly designed reactor, U metal chlorination experiments using NH4Cl chlorinating agent were performed to confirm the optimal experimental conditions. The detailed results will be further discussed.
        10.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated the effect of solid culture medium on the production of cordycepin in Cordyceps militaris. The regression equation was expressed as follows: Y1= 755.3-58.6625X1+4.79432E-14X2-46.6625X3-5.66269E-14X1X2- 0.025X1X3+1.62475E-14X2X3-160.6625X1 2+0.0125X2 2-206.9625X3 2, where, Y represents the value of cordycepin content (μg/g), X1 corresponds to the weight of M. alternatus in solid culture medium (g/bottle), X2 to the water content of the solid culture medium (%), and X3 to the culture period (day). The solid culture medium was optimized using the response surface methodology, and the optimal medium composition was as follows: the weight of M. alternatus in solid culture medium and water content were 16.2% and 100.7% (20.14 mL water/20 g solid culture medium), respectively, with a culture period of 39 days. Under these conditions, the cordycepin content of the fruiting bodies reached 150.0 μg/g (actual value). The supplementation of M. alternatus in solid culture for improved cordycepin content of C. militaris seems to be a promising alternative to wild and solid cultivation.
        4,000원
        11.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Roridin E, produced by Podostroma cornu-damae, is a mycotoxin with anticancer activity. To increase the content of roridin E, submerged culture conditions were optimized using response surface methodology. Three factors, namely, medium initial pH, incubation time and agitation speed were optimized using a Box–Behnken design. The optimum submerged culture conditions to increase the content of roridin E included a medium with an initial pH of 4.0, an incubation time of 12.90 days, and an agitation speed of 63.03 rpm. The roridin E content in the submerged culture, under the aforementioned conditions, was 40.26 mg/L. The findings of this study can help lower the current price of roridin E and promote its related research.
        4,000원
        12.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The choice of the culture medium is an important factor for the mass production of mycelia in submerged cultures. The influence of liquid medium on the mycelial dry weight of Paecilomyces tenuipes was investigated in this study. The regression equation is expressed as Y=-1292.94187+17.78612X1+18.92425X2+2.11464X3-0.019375X1X2-0.006276X1X3+0.008177X2X3- 0.070169X1 2-0.292175X2 2-0.008818X3 2, where Y represents the value of the mycelial dry weight (g/L), X1 is the particle size of wood sawdust in liquid medium (mesh), X2 is the concentration of the wood sawdust in liquid medium, and X3 is incubation time (h). The medium was optimized using a response surface methodology, and the optimal medium contained 30 g of wood sawdust (140 mesh), 20 g of glucose, and 10 g/L of peptone. Under these conditions, the mycelial dry weight reached 38.1 g/L (actual value). The culture medium containing wood sawdust is simple and easy to use, highly efficient, and eco-friendly, and its effectiveness in large preparations of P. tenuipes mycelia with low material costs has been demonstrated.
        4,000원
        14.
        2018.10 구독 인증기관·개인회원 무료
        Destruxins (Dtxs) are insecticidal cyclic hexadepsipeptides produced by the entomopathogenic fungus Metarhizium anisopliae. Media composition for dtxs production was optimized with industrial grade media. Glycerol and casein peptone were selected as a carbon source and a nitrogen source, respectively. Dtxs production varied with C/N ratios. High yields of dtxs were observed at C/N ratios ranging 0.3 to 1.5, with concentrations mostly higher than 800 mg/L. Low yields were caused by high C/N ratio ranging from 3.0 to 8.0, resulting in less than 500 mg/L. The highest yield of Dtxs was obtained with 2% glycerol and 3% casein peptone, showing 192.2 mg/L of dtx A, 911.1 mg/L of dtx B, and 113.3 mg/L of dtx E, respectively. These results indicated that dtxs production is highly influenced by C/N ratio, especially the content of nitrogen source.
        16.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        깨다시 꽃게(Ovalipes punctatus)는 갑각류로서 우리나라에서 잡히는 매끈 꽃겟속, 주름 꽃 겟속, 톱날 꽃겟속, 민 꽃겟속, 두갈래 민꽃겟속 들 중에 하나이다. 대부분의 꽃게는 가공되지 않은 상태로 찜 또는 찜육 등 반 가공 형태로 산업화 되었지만 최근에 게로부터 생리활성을 나타내는 펩타이드를 생산하는 연구가 발표되고 있다. 본 연구는 항산화 기능성을 나타내는 펩타이드를 선별하고 생산 최저공정 확립에 연구를 수행 하였다. 사용된 효소 alcalase, bromelain, flavourzyme, neutrase, papain, protamex들 중에서 bromelain으로 생산된 꽃게육 단백질 가수분해물이 가장 높은 활성을 보여 주었다. 꽃게육 단백질의 bromelain 가수분해물의 펩타이드들의 분자량 분포는 500-3,200 Da로서 7 종류의 이상의 펩타이드들로 구성되었다. 가수분해물의 구성아미노산 분포는 항산화 기능성에 관련된 소수성 아미노산은 전체 42.54%를 차지하였다. 가수분해물의 최적 생산 수율 조건을 확립하기 위하여 공정 조건, 효소 반응 온도 40-60℃, pH 6-8, 효소의 농도 1–3%(w/v)로 표면반응 분석법을 수행한 결과 효소 반응온도 55℃, 반응 pH 6.5, 효소의 양은 3%(w/v)에서 결정되었다. 최적 조건에서 단백질 가수분해도는 최대 71.60%에 도달하였다.
        4,200원
        17.
        2018.05 구독 인증기관·개인회원 무료
        A사는 발전 플랜트, 오수처리장, 취수, 정수, 배수장, Oil Plant 등 국가 기간 산업현장에서 사용되는 전동 액추에이터를 제조하고 있다. A사가 각 수요처별로 각기 다른 기능을 필요로 하는 Order에 대응하여 제품을 생산하고자 기존의 A사가 적용하고 있는 생산방식인 라인로트생산방식이 가지고 있는 문제점을 파악하여 개선하고자 한다. 본 연구를 통해 시장과 고객의 요구에 유연하게 대응할 수 있도록 다품종 소량생산에 적합한 셀 생산방식으로 변경을 통하여 생산유연화와 생산성향상을 이룰 수 있었다. 이러한 개선을 통하여 다변화하는 고객의 요구에 실시간으로 대응 할 수 있음은 물론이고 생산성향상과 그에 따른 이익창출을 이뤄낼 수 있는 계기가 될 것이다. 또한 A사의 생산 작업자의 업무 능력배양에 긍정적으로 작용하여 일을 하는 재미와 이에 따른 보상의 기대치를 높일 수 있는 계기로 작용하였다.
        18.
        2018.04 구독 인증기관·개인회원 무료
        In order to develop solid mass cultivation technology that maximizes insecticide of entomopathogenic nematode(EPN) isolated from Korea, we have studied the optimization of solid culture medium and production conditions. The optimized conditions from the harvest yields and the insecticidal activity against the Galleria mellonella larvae were yeast extract 2.0%, soybean flour 20%, whole milk powder 3%, olive oil 5% and egg yolk 5%. It was also found that the optimum condition of the carrier(polyurethane) content was about 8-12%, the culture time of symbiotic bacteria was about 48 hours, and the inoculation concentration of nematode was 4,000-5,000 per g medium. And the optimal harvesting point in solid culture conditions was confirmed after 12 days of inoculation.
        19.
        2018.04 구독 인증기관·개인회원 무료
        Tyrosinase is a key enzyme in animal melanogenic pathway that is the rate-limiting step for the production of melanin. Several synthetic and naturally occurring tyrosinase inhibitors have been studied for skin whitening, the development of natural agents is becoming more important due to the disadvantages of synthetics such as high cytotoxicity, insufficient penetration power, and low activity. The purpose of this study was to evaluate the polyphenols, antioxidant and tyrosinase inhibition activity of mealworm (Tenebrio molitor) extract and optimization of extraction condition using statically-based optimization. The results showed that extraction temperature of 92.0°C, extraction time of 36.7 min, and ethanol concentration of 79.5% provided the maximum levels of compounds of 5.69 mg GAE/g DW, tyrosinase inhibition of 78.8%, and radical scavenging activity of 100.8 μg/ml in the validation experiment.
        20.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effects of blanching time (1-5 min), types of blanching solution (1% NaCl vs 1-3% sucrose), addition of packaging with blanching solution, and thawing methods (thawing in packaged versus depackaged units) on the qualities of frozen Aster scaber. As quality parameters, drip loss, moisture content, shear force, color, and sensory test were conducted. Aster scaber was blanched in 1% sucrose for 4 min and packaged with the same solution prior to freezing whereas frozen Aster scaber exhibited palatable quality when it was removed from the package and thawed in running water. Consequently, this study demonstrated that the optimized processing condition provided qualities like non-frozen control.
        4,000원
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