• 제목/요약/키워드: optimal composition rate

검색결과 143건 처리시간 0.027초

질소가 포함된 탄소나노튜브의 질소 원자를 이용한 이중 금속 촉매 제조 및 그의 수소 발생 촉매 특성 분석 (Facile Fabrication of Bimetallic Catalysts via Selective N atoms of N-Doped Carbon Nanotubes and Their Superior Catalytic Activities for Hydrogen Generation)

  • 신원호;정형모;최윤정;강정구
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.111.2-111.2
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    • 2010
  • One-dimensional nanostructures such as carbon nanotubes could be ideal templates for formation of metallic nanoparticles. Furthermore, bimetallic component nanoparticles have recently been interesting issues for having high catalytic activity. This work provides both a facile method to synthesize bimetallic catalysts via N atoms of carbon nanotubes and also a picture about how to design the optimal bimetallic catalyst for hydrogen generation from the hydrogen storage material. In principle, the ratio of one component to another component could be generically extended to fabricate the high-performance bimetallic catalysts on host nanostructures. Indeed, we demonstrate that the bimetallic catalyst composed of the optimum composition results in the excellent hydrogen generation property from an aqueous borane ammonia solution, thus being capable of satisfying the Depart of Energy in USA target required for many advanced applications even with the small amount of our bimetallic catalysts attached onto the N-doped carbon nanotubes. This high hydrogen generation rate is found to be attributed to the optimal distance between active Pt and cheap Ni atoms for effective hydrogen generation.

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Optimization of Hydroxyl Radical Scavenging Activity of Exopolysaccharides from Inonotus obliquus in Submerged Fermentation Using Response Surface Methodology

  • Chen, Hui;Xu, Xiangqun;Zhu, Yang
    • Journal of Microbiology and Biotechnology
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    • 제20권4호
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    • pp.835-843
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    • 2010
  • The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different components of the medium. Corn flour, peptone, and $KH_2PO_4$ were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, $KH_2PO_4$ 0.26, $MgSO_4$ 0.02, and $CaCl_2$ 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose, and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%.

곤충세포-배큘로바이러스 시스템에서 재조합 단백질 생산을 위한 최적 감염시기 및 배지조성 (Optimal Infection Time and Medium Composition for the Production of Recombinant Protein in Insect Cell-Baculovirus System)

  • 하성호;이성환박태현
    • KSBB Journal
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    • 제10권3호
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    • pp.317-322
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    • 1995
  • 유전자 재조합 단백질 생산을 위한 곤충세포- 배쿨로바이러스 시스템에 있어서, 바이러스에 감염시 키는 시기가 늦을수록 재조합 단백질의 발현이 낮게 나타났다. 이것은 높은 세포농도일수록 단위세포당 낮은 발현율을 의미하므로 재조합 단백질 생산을 위 해 감염시기에 대한 최적화의 필요성을 보여주며, 재조합 단백질의 최대 생산생을 위한 최적 감염시기 의 존재를 실험적으로 업증하였다. 또한 배지에 5% 누에 체액을 보강함으로써 발현율이 증가하였고, 이 것은 누에 체액 첨가로 인해 세포내 바이러스 숫자가 증가하고 감염 후 세포의 생존성이 오래 유지되 는 것에 기 인하는 것으로 생각된다. 고농도 세포배 양을 위해 yeastolate를 첨가하고, 재조합 단백질 발 헌을 위해 누에 체액을 첨가함으로써 ${\beta}$-galactosidase의 생산이 10배 정도 증가하였다.

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목질계 바이오매스의 이용(제3보)-탈리그닌 처리한 폭쇄재의 산가수분해- (Utilization of Ligno-cellulosic Biomass(III)-Acid Hydrolysis of Exploded Wood after Delignification)

  • 양재경;장준복;임부국;이종윤
    • 펄프종이기술
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    • 제29권4호
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    • pp.18-27
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    • 1997
  • This study was performed to obtained the optimal delignified condition of exploded wood on the acid hydrolysis with sulfuric acid. Wood chips of pine wood(Pinus desiflora), oak wood(Quercus serrata) and birch wood (Betula platyphylla var. japonica) were treated with a high pressure steam (20-30kgf/$\textrm{cm}^2$, 2-6 minutes). The exploded wood was delignified with sodium hydroxide and sodium chlorite, and then hydrolyzed with sulfuric acid. The result can be summerized as follows ; In the exploded wood treated with sodium hydroxide, the optimal concentration of sodium hydroxide was 1% as content of lignin in the exploded wood. Lignin content of exploded wood treated with sodium chlorite was lower then that sodium hydroxide. The maximum reducing sugar yield of exploded wood treated with 1% sodium hydroxide was lower than non-treated exploded wood. In the case of sodium chlorite treated, the maximum reducing sugar yield was hgher than non-treated exploded wood. Sugar composition of acid hydrolysis solution was composed of xylose and glucose residue, and the rate of glucose residue was increased in high pressure condition.

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SCP 생산용 메탄올 자화균주의 연속배양에 의한 배지 최적화 (The Medium Optimization through Continuous Culture of an Methanol Utilizing Bacterium for SCP Production)

  • 김창호;김태진홍석인
    • KSBB Journal
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    • 제5권4호
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    • pp.355-363
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    • 1990
  • 서울 인근의 생활하수에서 메탄올을 이용하는 박테리아를 분리하였다. 이의 최적 성장을 위한 온도 및 pH는 각각 $33^{\circ}C$ 및 7.1이었다. 최대비성장율은 $0.42hr^{-1}$을 나타내었다. 최소 배지조성은 기본배지의 양을 안정상테에서 연속발효법으로 구하였으며, 그 조성은 다음과 같다(g / l); Methanol 40, $(NH_4)_2\;SO_42,\;KH_2PO_4\;1.5,\;K_2HPO_4\;0.2,\;H_3PO_4\;0.79,\;Na_2HPO_4{\cdot}12H_2O\;0.15,\;MgSO_4{\cdot}7H_2O\;1.5,\;FeSO_4{\cdot}7H_2O\;0.034,\;MnSO_4{\cdot}4H_2O\;0.005,\;CuSO_4{\cdot}5H_2O\;0.0027,\;CaCl_2{\cdot}2H_2O\;0.25,\;ZnSO_4{\cdot}7H_2O\;0.007,\;(NH_4)_6\;Mo_7O_{24}{\cdot}4H_2O\;0.00048,\;H_3BO_3\;0.00068,\;CoCl_2\; 0.00024$ 최적 배지 조건에서 구한 최대 세포생산성은 3.8g / l / hr였으며, 이때의 회석율은 $0.23hr^{-1}$이었다. 최대 세포농도와 그대의 단백질의 함량은 각각 19.5g / l 및 70%였으며, 이때의 회석율은 $0.1hr^{-1}$이었다.

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상황버섯균사체 쌀을 이용한 죽의 품질특성 (Quality Characteristics of Porridge Containing Rice incubated with Phellinus linteus Mycelium)

  • 김지현;전순실
    • 한국식품영양학회지
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    • 제30권3호
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    • pp.560-567
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    • 2017
  • In this study, we investigated the quality characteristics and optimum conditions of porridge containing rice incubated with Phellinus linteus mycelium (PLMR). Composition measurements of PLMR were moisture 13.05%, ash 0.88%, carbohydrate 78.65%, crude protein 6.29%, and crude lipid 1.13%, also glutinous rice composition was moisture 13.99%, ash 0.32%, carbohydrate 77.18%, crude protein 7.85%, and crude lipid 0.66%. The water absorption rate of PLMR increased with increasing soaking time during 6 hours. However, the water absorption rate of glutinous rice increased until 30 minutes of soaking time. The pH of porridge was decreased as PLMR contents increased. The viscosity of porridge was increased as PLMR contents increased, and it was the lowest for the control at 914.77 cP. However, spreadability of porridge was decreased as PLMR contents increased. In terms of color, lightness was the highest for the 50% level, redness was the highest for the 75% level, and yellowness was the highest for the 25% level. In terms of textural characteristics, hardness and fracturability were increased as PLMR contents increased, whereas springiness, cohesiveness and resilience showed reverse results. In terms of consumer acceptance, flavor, appearance, viscosity, delicate taste, and overall acceptability were not significantly different between samples. Hot taste was decreased as PLMR contents increased, whereas grittiness showed reverse results. In conclusion, the results indicate that adding 25~50% PLMR to porridge is optimal for a recipe.

순환여과양식시스템에서 사료 공급 횟수가 연어(Oncorhynchus keta) 치어의 성장, 체조성 및 혈액성분에 미치는 영향 (Effect of Different Feeding Frequency on the Growth Performance, Hematological Parameters and Body Nutrient Composition of Juvenile Chum Salmon Oncorhynchus keta Reared in a Recirculating Aquaculture System)

  • 조규석;장석우;이유진;이승형
    • 한국수산과학회지
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    • 제56권5호
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    • pp.734-740
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    • 2023
  • The effect of feeding frequency on growth performance, body nutrient composition, and hematological parameters of juvenile chum salmon Oncorhynchus keta was investigated. The juveniles (10.9±0.3 g) were fed commercial feed for 30 days with feeding frequencies of 1, 2, 3, 4, or 5 meal (s)/day (n=2 tanks per treatment) in a recirculating aquaculture system (RAS). Fish were fed to satiation at each of the feeding frequencies. At the end of the feeding trial, final body weight, weight gain, and specific growth rate of fish fed 2 meals/day were significantly higher than those of fish fed 1 meal/day(P<0.05); however, no difference was detected among the other feeding frequencies. Daily feed intake significantly increased with increasing feeding frequency, whereas feed and protein utilization efficiencies continuously decreased with increase in the feeding frequency. Among the treatments, fish fed 1 meal/day showed the lowest value in whole-body lipid content and total protein concentration in plasma. Taken together, the optimal feeding frequency for growth performance and feed utilization efficiency in chum salmon juveniles reared in the RAS was determined to be 2 meals/day.

A Simplified Efficient Algorithm for Blind Detection of Orthogonal Space-Time Block Codes

  • Pham, Van Su;Mai, Linh;Lee, Jae-Young;Yoon, Gi-Wan
    • Journal of information and communication convergence engineering
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    • 제6권3호
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    • pp.261-265
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    • 2008
  • This work presents a simplified efficient blind detection algorithm for orthogonal space-time codes(OSTBC). First, the proposed decoder exploits a proper decomposition approach of the upper triangular matrix R, which resulted from Cholesky-factorization of the composition channel matrix, to form an easy-to-solve blind detection equation. Secondly, in order to avoid suffering from the high computational load, the proposed decoder applies a sub-optimal QR-based decoder. Computer simulation results verify that the proposed decoder allows to significantly reduce computational complexity while still satisfying the bit-error-rate(BER) performance.

Nutritional Support Strategies for the Preterm Infant in the Neonatal Intensive Care Unit

  • Hay, William W. Jr.
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제21권4호
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    • pp.234-247
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    • 2018
  • The goal of nutrition of the preterm infant is to "provide nutrients to approximate the rate of growth and composition of weight gain for a normal fetus of the same postmenstrual age and to maintain normal concentrations of blood and tissue nutrients" (American Academy of Pediatrics 2014). Failure to provide the necessary amounts of all of the essential nutrients to preterm infants has produced not only growth failure, but also increased morbidity and less than optimal neurodevelopment. This continues to be true despite many efforts to increase nutrition of the preterm infants. In contrast, enhanced nutrition of very preterm infants, both intravenous and enteral, beginning right after birth, promotes positive energy and protein balance and improves longer term neurodevelopmental outcomes. The benefits are long lasting too, particularly for prevention of later life chronic diseases.

폴리피롤 첨가에 의한 supercapacitor용 저 임피던스 전극 (Electrode of Low Impedance by Polypyrrole Addition for Supercapacitor)

  • 김경민;장인영;강안수
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2003년도 추계학술대회
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    • pp.343-350
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    • 2003
  • The best Ppy weight ratio was 7 wt% and the optimal electrode composition ratio was 78 : 17 : 5 wt.% of (MSP-20 : BP-20 =1 : 1), (Super P : Ppy =10 : 7) and P(VdF-co-HFP). Implantation of Ppy as the conducting agents have led to superior electrochemical characteristics because of the low of internal resistance and faradaic capacitance. The result of unit cell with Ppy 7 wt% were as follows: 28.02 Fig of specific capacitance, 1.34 Ω of DC-ESR and 0.36 Ω of AC-ESR. Unit cell showed a good stability up to 200 charge-discharge cycles, retaining 82% of their original capacity at 200 cycles. From the analysis of impedance, the electrodes with Ppy 7 wt% showed low ESR, low charge transfer resistance and quick reaction rate. It was inferred that quick charge-discharge was possible. As compared with the specific capacitance (rectangular shape) of CV, it was also concluded that the specific capacitance originated from thecompound phenomena of the faradaic capacitance by oxidation and reduction of Ppy and the non-faradaic capacitance by adsorption-desorption of activated carbon.

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