• Title/Summary/Keyword: enrichment

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An Experimental Study on Performance Characteristics of a Hydrogen Fuelled Spark Ignition Engine

  • Han, Sung Bin
    • Journal of Energy Engineering
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    • v.23 no.1
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    • pp.81-89
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    • 2014
  • The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.76 to 1.5, and the ignition timing was controlled to be at minimum spark advance for best torque (MBT).

Effect of Exhaust Heat Exchanger on Catalytic Converter Temperature in an SI Engine (가솔린 엔진의 배기 열교환기가 촉매 온도에 미치는 영향에 관한 연구)

  • 이석환;배충식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.2
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    • pp.9-16
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    • 2004
  • Close-coupled catalyst (CCC) can reduce the engine cold-start emissions by utilizing the energy in the exhaust gas. However, in case the engine is operated at high engine speed and load condition, the catalytic converter may be damaged and eventually deactivated by thermal aging. Excess fuel is sometimes supplied intentionally to lower the exhaust gas temperature avoiding the thermal aging. This sacrifices the fuel economy and exhaust emissions. This paper describes the results of an exhaust heat exchanger to lower the exhaust gas temperature mainly under high load conditions. The heat exchanger was installed between the exhaust manifold and the inlet of close-coupled catalytic converter. The exhaust heat exchanger successfully decreased the exhaust gas temperature, which eliminated the requirement of fuel enrichment under high load conditions. However, the cooling of the exhaust gas through the heat exchanger may cause the deterioration of exhaust emissions at cold start due to the increment of catalyst light-off time.

Examination of Optimal Reaction Mechanism in Oxygen Enriched Condition (산소부화조건에서의 반응기구 검토)

  • Han, Ji-Woong;Lee, Chang-Eon
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.247-253
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    • 2003
  • Burning velocities of conventional methane flame and oxygen-enriched methane flame were determined by experimentally and numerically at atmospheric pressure in order to examine the validity of various detailed reaction mechanisms in oxygen-enriched flame. The schlieren system was adopted to obtain the burning velocity of flame stabilized on a circular nozzle. Premix code was employed to compute the burning velocity. Three reaction mechnisms were tested at several oxygen enrichment level, whose names are GRI 3.0, MB(Miller and Bowman) and LKY(Lee Ki Yong) reaction mechanism. Sensitivity analysis was also performed to discriminate dominantly affecting reaction on burning velociy. The results showed that conventional reaction mechanisms originally based on methane-air flame were underpredict the burning velocity at high oxygen-enrichment level. The modified GRI 3.0 reaction mechanism based on our experimental results was suggested and shows a good agreement in estimating the burning velocity and the NO number density of oxygen-enriched flame.

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Development and evaluation of enrichment program for the relationship of young daughter-in-law with their mothers-in-law (젊은 며느리를 위한 고부관계 향상 교육 프로그램의 개발 및 평가)

  • 정혜정
    • Journal of Families and Better Life
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    • v.14 no.4
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    • pp.13-26
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    • 1996
  • Based on the conceptual framework of Double ABCX model of family stress and adaptation this study developed the enrichment program for the relationship of young daughters-in-law with their mothers-in-law. Results of empirical research concerning the relationship between them also provided for the basis of designing this program. Consisting of 6 sessions this education program was delivered to 20 young daughters-in-law in a rural area of Kyunggi-do province. The effectiveness of the program was evaluated through one-group posttest design and follow-up interview. Overall most participants in the program reported that the relationship with their mothers-in-law was enhanced in terms of understanding mothers-in-laws psychology and roles of improving communication and problem-solving skills self-control and of blaming.

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Brain Plasticity and Stroke Rehabilitation (뇌가소성과 뇌졸중 재활)

  • Kim, Sik-Hyun
    • PNF and Movement
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    • v.6 no.2
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    • pp.39-50
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    • 2008
  • Purpose : This article reviewed the advances in the understanding of the effect of motor rehabilitation and brain plasticity on functional recovery after CNS damage. Methods : This is literature study with Pubmed, Medline and Science journal. Results : The inability of CNS neurons to regenerate is largely associated with nonneuronal aspects of the CNS environment. Especially, this neuronal growth inhibition is mediated by myelin associated glycoprotein, olygodendrocyte-myelin glycoprotein, and NOGO. Enriched environment, motor learning, forced limb use have been utilized in scientific studies to promote functional reorganization and brain plasticity. Especially, enriched environment and motor enrichment may prime the brain to respond more adaptively to injury, in part by expressed neurotrophic factors. Conclusions : These reviews suggest that activity-induced neural plasticity occur in damaged brain areas in order to functional reorganization, where it could contribute to motor recovery, and represent a target for stroke rehabilitation.

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Geology and Ore Deposits of Geoje Dong-A Mine (거제(巨濟) 동아광산(東亞鑛山)의 지질(地質) 및 광상(鑛床))

  • Kim, Jong Dae
    • Economic and Environmental Geology
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    • v.19 no.spc
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    • pp.103-112
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    • 1986
  • The geology of the mine consists of Cretaceous lower andesitic breccia member, tuffaceous black shale, upper tuffaceous sandstone member and andesitic dike. Ore bodies are two parallel veins of breccia originated from hydrothermal activity of later acidic igneous intrusion. First two periods of mineralization, gold and silver, and copper, and later copper enrichment was identified. The first two might have been occurred during boiling of hydrothermal solution that formed breccia and copper enrichment was accomplished by enhancement of $CO_2$ fugacity from the organic material contained in the black shale. With all the geologic and mineralogic data and inferences attained from other investigators it was estimated that the optimum depth of the ore mineralization was between 500m and 300m below the surface of Kyong-Sang series.

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An Exploratory Program on the Enrichment of Marital Intimacy (자기인식 향상을 통한 부부친밀감 증진 프로그램 시안 -우리 부부에 대해 새롭게 알기-)

  • 이경희;옥선화
    • Journal of the Korean Home Economics Association
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    • v.37 no.8
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    • pp.29-42
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    • 1999
  • The purpose of this study was to develop the new marital intimacy enrichment program. Some family counselors(or therapists) and 3 couples'interviewees helped to design this program. This program intended to increase couples to understand one's personality, feeling, and behavior each other. For the purpose of it, two psychological theories and two family therapy theories were provided for the base of this program. This program is consisted of 6 sessions that are Sharing, Real Understanding of Our Personalities 1, Understanding of Our Personalities H, Understanding of Our family of Origins and Habits, Understanding of Our Recent Life, and Understanding of Our Feelings, aiming for increasing couple's cognitive, affective, and sexual intimacy.

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