• 제목/요약/키워드: its mixture

검색결과 2,010건 처리시간 0.031초

점화에너지 특성이 예혼합기의 착화와 연소에 미치는 영향(2) (Effect of Ignition Energy Characteristics on the Ignition and the Combustion of a Premixed Gas(2))

  • 이중순;강병무;김현수;정성식;하종률
    • 한국자동차공학회논문집
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    • 제5권6호
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    • pp.183-191
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    • 1997
  • For the improvement of ignitability we need ignition energy and its discharge characteristics which are suitable for a part distribution of the mixture density around the ignition spark plug and the flow characteristics of the mixture in the combustion. Especially, for the solving of the instability of initial ignition and lean ignitability limit in the case of lean-burn combustion, the more powerful ignition energy is required. The conclusions from the observation can be summarized as follows: 1) The ignitability limit for HIS expands wider and the combustion is more stable than for CDI. 2) The combustion duration and ignition timing depend upon the distribution of local mixture density in the vicinity of ignition spark plug.

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Biodiesel Production Using a Mixture of Immobilized Rhizopus oryzae and Candida rugosa Lipases

  • Lee, Dong-Hwan;Kim, Jung-Mo;Shin, Hyun-Yong;Kang, Seong-Woo;Kim, Seung-Wook
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권6호
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    • pp.522-525
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    • 2006
  • Biodiesel conversion from soybean oil reached a maximum of 70% at 18 h using immobilized 1,3-specific Rhizopus oryzae lipase alone. Biodiesel conversion failed to reach 20% after 30 h when immobilized nonspecific Candida rugosa lipase alone was used. To increase the biodiesel production yield, a mixture of immobilized 1,3-specific R. oryzae lipase and nonspecific C. rugosa lipase was used. Using this mixture a conversion of greater than 99% at 21 h was attained. When the stability of the immobilized lipases mixture was tested, biodiesel conversion was maintained at over 80% of its original conversion after 10 cycles.

Mixture Filtering Approaches to Blind Equalization Based on Estimation of Time-Varying and Multi-Path Channels

  • Lim, Jaechan
    • Journal of Communications and Networks
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    • 제18권1호
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    • pp.8-18
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    • 2016
  • In this paper, we propose a number of blind equalization approaches for time-varying andmulti-path channels. The approaches employ cost reference particle filter (CRPF) as the symbol estimator, and additionally employ either least mean squares algorithm, recursive least squares algorithm, or $H{\infty}$ filter (HF) as a channel estimator such that they are jointly employed for the strategy of "Rao-Blackwellization," or equally called "mixture filtering." The novel feature of the proposed approaches is that the blind equalization is performed based on direct channel estimation with unknown noise statistics of the received signals and channel state system while the channel is not directly estimated in the conventional method, and the noise information if known in similar Kalman mixture filtering approach. Simulation results show that the proposed approaches estimate the transmitted symbols and time-varying channel very effectively, and outperform the previously proposed approach which requires the noise information in its application.

흰쥐에서 Curcuminoid 및 이를 함유한 천연식물 혼합물이 심혈관계에 미치는 영향 (Effect of Curcuminoids and Natural Plants Extract Mixture on the Cardiovascular System in Rats)

  • 안수현;이종호;박하림;권승택;고유석;손영덕;장양수;정광회
    • Journal of Nutrition and Health
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    • 제36권2호
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    • pp.101-108
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    • 2003
  • Antiplatelet aggregation, anticoagulant and lipid-lowering drugs are clinically widely used for secondary preventive purpose in the cardiovascular patients, but there is no primary preventive agents to prevent these diseases. With the aim of developing effective primary agents for cardiovascular diseases, we tried to formulate an optimized mixture of natural plants extract containing Theae sinensis, Camelliae sinensis, Vitis vinifera, Gingko folium and curcuminoids from Curcuma longa and to evaluate its anti-thrombotic and anti-hypercholesterolemic effects in vivo. The inhibitory effect of curcuminoids on vascular smooth muscle cell proliferation and migration were also investigated in vitro. in the animal experiments treated with hyperlipidemic diet, oral treatment of curcuminoids and natural plants extracts mixture (100 mg/kg) into male Sprague Dawley rats for 7 week simultaneously inhibited platelet aggregation as well as improved lipid profile in the blood. Compared to control group, both of curcuminoids-treated and mixture-treated groups revealed significantly decrease of total cholesterol (24.4%, 28.6%), free cholesterol (25.1%, 24.0%), cholesterol ester (14.6%, 29.0%), LDL-cholesterol (27.0%, 32.0%) and triglyceride (15.0%, 31.0%), respectively. However, both groups showed increase of HDL-cholesterol (46.6% and 51.5%) . In particular, atherogenic index of curcuminoids and mixture treatment group was significantly decreased to 47.0% and 56.0%, respectively. Furthermore, oral treatment of curcuminoids and mixture significantly inhibited collagen-induced platelet aggregation (21.1% and 29.1%, respectively), compared to control group. The anti-thrombotic values of mixture was almost similar to that of aspirin treatment (100 mg/kg) group. These results suggest that the oral treatment of curcuminoids-based natural plant extract mixture improved cardiovascular conditions in hyperlipidemic rats.

국내 패션잡지에 나타난 민족적 요소의 하이브리드 경향 (Hybridization of Ethnic-Cultural Elements Shown in Domestic Fashion Magazines)

  • 김선영
    • 복식
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    • 제61권8호
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    • pp.45-56
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    • 2011
  • This study is about the features of hybridization of ethnic-cultural elements in Korean fashion magazines. Its purpose was to embody more creative and newer images in fashion by promoting better mutual understanding of foreign cultures and addressing the issues of fashion design from multicultural perspectives. In doing so, the present study conducted a literature review and analyzed a total of 130 photographic images with any hybrid ethic element from two Korean fashion magazines, Vogue Korea and Harper's Bazaar Korea, issued between 2005 and 2009. The analysis revealed that there were 66 images(50.8%) with a mixture of two different cultures and 64 images(49.2%) with a mixture of three or more different cultures. As seen from the results, the two categories had a similar number of cases. In regional terms, the use of two different cultural elements included a mixture of Asian and Western cultures in 32 images(24.6%), a mixture of Western and African, Middle Eastern or Latin American cultures in 23(17.7%), and a mixture of Western and Russian or European folk cultures in 11(8.5%). In the use of three or more different cultural/national elements, the present study found a mixture of Asian, African, Middle Eastern, Latin American and Western costume items in 20 photo images(15.4%), a mixture of African, Middle Eastern and Latin American elements plus Western costume items in 19 images( 14.6%), a mixture of all regional cultures in 13 photos(10%), and a mixture of Asian ethic cultures plus Western costume items in 12 cases(9.2%). The results of this analysis indicated that the hybridization of ethnic-culture elements in Korean fashion magazines consisted of diverse clothing and accessories from various ethnic groups. The expression of these multi-cultural hybrid images that consists background images and models from different cultures well-portrayed the multi-cultural elements based on total coordination and broke the stereotypical aspects of styling.

Amylase 생산세균 및 생산능의 촉진조건에 관한 연구 1 (Studies on amylase producing bacteria and its stimulaton. (I))

  • 이두영
    • 미생물학회지
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    • 제7권2호
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    • pp.86-90
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    • 1969
  • 1. Amylase producing bacteria have been isolated from natural sources and was identified out. The above strain is identical to Bacillus subtillis in every details of physiological and morphorogical characteristics by this investigations. 2. Sikworm chrysalis nad chlorella extracts are prove to be further effective for the stimulation of amylase production than any other sources. The former silkworm extract is more stronger in its activity. 3. It is found that effective results had been accepted by a less soybean meal addition per that of wheat bran in the mixture ratio of them, also less addition of corn is needed in the mixture ratio of between corn and whear bran. In the mixing ratio of wheat bran per silkworm or chlorella extracts, the addition of wheat bran is necessary for stimulation of amylase production. 4. Fro the stimulation of amylase production, the effective substances from natural sources and its order of activity in cultral media cultral media is proved as follows, silkworms ext.>chlorella ext.>alcohol>skim-milk and peptone>fermented milk>radish leaf ext.

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Potassium hexatitanate의 합성과 박막형 Matrix 제작에 관한 연구 (Studies on the Synthesis of Potassium Hexatitanate and Manufacturing Thin Film Type Matrix)

  • 심중표;이홍기;이주성
    • 한국표면공학회지
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    • 제26권6호
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    • pp.299-306
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    • 1993
  • The characteristic of synthesized potassium hexatitanate and manufacturing of thin film type matrix for battery was studied. After ball milled the mixture with 1:4 of $K_2CO_3$ and TiO2, mixsture was sintered at 85$0^{\circ}C$ and its product was confirmed with XRD. Adding the PTFE to the obtained potassium hexatitanate according to there various ball-mill time to control its particle size, thin film type matrix was manufactured. The high-est wettability of 50% was found with 12 hour ball milled powder containing 10w/o of PTFE and also it shown good mechanical properties. The matrix with $K_2O$$\cdot$$6TiO_2$ whisker shown 170% of wettability. Thed char-acteristics of matrix made by whisker and powder mixture were compared with the investigation of bubbled pressure and pore size distribution to improve its mechanical properties.

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염산용액에서 Cyanex 272 및 혼합용매와 이온성 액체에 의한 Tb(III)의 용매추출 (Solvent Extraction of Tb(III) from Hydrochloric Acid Solution with Cyanex 272, Its Mixture and Ionic Liquid)

  • 오창근;이만승
    • 대한금속재료학회지
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    • 제56권12호
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    • pp.870-877
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    • 2018
  • Cyanex 272 shows the highest separation factor for the rare earth elements from hydrochloric acid solution among the organophosporus acidic extractants, D2EHPA and PC 88A. Solvent extraction of Tb(III) from weak hydrochloric acid solution with an initial pH 3 to 6 was compared with Cyanex 272, its mixture with Alamine 336, and ionic liquid with Aliquat 336. The solvent extraction reaction of Tb(III) using Cyanex 272 was the same as that of light rare earth elements. Synergism was observed for the extraction of Tb(III) by the mixture with Alamine 336 when the initial concentration ratio of Cyanex 272 to Alamine 336 was higher than 5. Use of the ionic liquid led to a great increase in the extraction percentage of Tb(III) from the same initial extraction conditions. While the equilibrium pH of the mixture was always lower than the initial pH, under some conditions extraction with the ionic liquid resulted in a higher equilibrium pH than the initial pH. The loading capacity of the mixture and the ionic liquid was the same and 2.6 times larger than that using Cyanex 272 alone. Ionic liquid was recommended as a suitable extractant for the extraction of Tb(III) from hydrochloric acid solution based on the ease of handling and higher extraction percentage.

복합확률분포의 파라메타 추정을 위한 EM 알고리즘의 적용 연구 (An Approach for the Estimation of Mixture Distribution Parameters Using EM Algorithm)

  • 심대영;김상구
    • 한국ITS학회 논문지
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    • 제22권4호
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    • pp.35-47
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    • 2023
  • 그동안 차두시간분포를 나타내는 확률분포로 음지수분포, Erlang 분포, 정규분포 등 다양한 단일확률분포들이 사용되어져 왔다. 그러나, 실제 도로에서 차두시간분포의 조사결과는 단일확률분포로서 설명하기 어려운 경우가 있었다. 본 연구는 차량의 차두시간에 대해 두 개의 정규분포가 일정한 관련성을 가지고 결합된 복합확률분포의 파라메타에 대해 최우추정법 중 하나인 EM 알고리즘을 이용하여 추정하는 접근방법을 시도하였다. 이에 대한 분석결과 기존에 알려진 단일확률분포로서 잘 설명되기 어려웠던 차량도착 차두시간 분포를 EM 알고리즘을 이용하여 복합확률분포의 파라메타를 추정하여 설명하였다. χ2 test 적합도 검정결과, 유의수준 1%에서 통계학적으로 유의성이 확보되어 EM 알고리즘을 이용한 복합확률분포의 파라메타 추정의 신뢰성이 입증되는 것으로 분석되었다.

식물추출 혼합제재인 phyto-extract mixture의 니트로세이션 억제능과 항산화능 분석 (Analysis of Nitrosation Inhibition and Antioxidant Effect by Phyto-Extract Mixture)

  • 김지훈;신미정;조희재;이상원;정종문
    • 한국식품과학회지
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    • 제33권6호
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    • pp.656-663
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    • 2001
  • 본 연구는 흡연에 의해 체내로 유입된 독성 물질들로 유발될 수 있는 폐암을 비롯한 각종 질병 기전을 in vitro 상에서 재현한 실험적 모델을 이용하여 8개의 식물로부터 추출한 phyto-extract mixture의 작용에 의하여, 체내 니코틴이 니트로사민으로의 전환되는 대사효율과 NNK의 활성화에 미치는 효과를 분석한 것이다. 이를 위해 in vitro 상에서 phyto-extract mixture에 의한 니트로소모폴린의 생성 억제와 CYP효소 활성 억제를 분석하였다. Phyto-extract mixture에 의한 니코틴으로부터 니트로소모폴린이 생성되는 대사 억제능 실험 결과, phyto-extract mixture(75%)는 비타민 C(64%)와 가루녹차(37%) 보다 우수한 억제 효능을 나타내므로서, phyto-extract mixture는 니코틴으로 부터 유독한 중간 대사물질이 생성되는 경로를 효과적으로 억제시킬 수 있음을 알 수 있었다. 또한 간에서 NNK 활성화에 관여하는 CYP 효소들에 대한 phyto-extract mixture의 효소 활성 억제능 분석 결과, phyto-extract mixture이 가루녹차보다 NNK로부터 발암물질이 생성되는 경로를 효과적으로 억제시키는 것으로 분석되었다. 결론적으로 phyto-extract mixture는 흡연으로 체내에 유입된 니코틴이 NNK와 같은 강력한 발암 물질인 니트로사민 유도체로 전환되는 경로를 효과적으로 억제함으로써 암 발생율을 효과적으로 낮출 수 있는 기능성 첨가제 혹은 식 음료로 활용될 수 있음을 in vitro 실험으로 증명하였다.

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