• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.6 s.249
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• pp.538-545
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• 2006

Stratified charge compression ignition (SCCI) combustion, also known as HCCI(homogeneous charge compression ignition), offers the potential to improve fuel economy and reduce emission. In this study, SCCI combustion was studied in a single cylinder gasoline DI engine, with a direct injection system. We investigated the effects of air-fuel ratio, intake temperature and injection timing such as early injection and late injection on the attainable SCCI combustion region. Injection timing during the intake process was found to be an important parameter that affects the SCCI region width. We also find it. The effects of mixture stratification and fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.391-401
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• 2020

This study verified the reliability and validity of the Korean version of the Student Career Construct Inventory(K-SCCI) that was translated into Korean language from the Student Career Construct Inventory (SCCI) developed by Savickas et al.(2018). To achieve this, this study conducted item content analysis, exploratory factor analysis, confirmatory factor analysis, and criterion-related validity in 530 university students. As a result of item content analysis and exploratory factor analysis, it was found that 4 factor models and 18 items were the most appropriate in K-SCCI. The 4 factors were named as crystallizing a vocational self-concept, exploring to gather information about occupations, deciding to commit to an occupational choic, and preparing to implement that choice. As a result of confirmatory factor analysis to verify the goodness-of-fit of the 4 factor models, it appeared to be appropriate. As a result of analyzing the correlation with related measures to verify the criterion-related validity of measures, it was found that student career construct was negatively correlated with employment anxiety but positively correlated with career adaptability.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.179-182
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• 2014

A comparative DNS study of the ignition characteristics of dual-fueled reactivity controlled compression ignition (RCCI) and stratification charge compression ignition (SCCI) is investigated using a 116-species reduced primary reference fuel (PRF) mechanism. In the RCCI combustion, two PRF fuels (n-heptane and iso-octane) with opposite autoignition characteristics are separatedly supplied and in-cylinder blended such that spatial variations in fuel reactivity, fuel concentration and temperature are achieved. In the SCCI combustion, however, just a single fuel (PRF50) is used such that only fuel concentration and temperature inhomoginieties are obtained. Because three factors, rather than only two as in SCCI combustion, govern the overall RCCI combustion, combustion timing and combustion duration or heat release rate of RCCI combustion are flexibly and effectively controlled. It is found that the overall RCCI combustion occurs much earlier and its combustion duration is longer compared to SCC combustionI. Moreover, the negative temperature coefficient (NTC) has a positive effect on enhancing RCCI combustion by inducing a shorter combustion timing and a longer combustion duration as a result of the occurrence of a predominant low-speed deflagration-combustion mode.

• Asia-Pacific Journal of Business
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• v.2 no.1
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• pp.1-22
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• 2011

Chamber of commerce and industry plays important role for development of business community and creating vibrant competition. Present paper compares chambers operations in Bangladesh, especially, Sylhet Chamber of Commerce and Industry(SCCI) by reviewing global models of chambers practices. The study identifies important gaps between international standards and Bangladesh practices. Mostly practiced chambers model in the world are: Continental Model, Anglo-Saxon Model and Mixed model or Asian model. Like other Asian countries, chambers in Bangladesh including SCCI, have been following Mixed Model. The empirical study found that SCCI is performing different developmental functions like accumulating members, collecting revenue, fulfilling corporate social responsibility and providing business development services to its members and business community. The notable constraining factors of SCCI operations are: short term orientation in assembling members, limited functional activities, lack of creative endeavors in diversifying services, linkage between SCCI and academic institutions, poor research involvement etc. The necessary suggestions for improvement of chambers performance include adoption of creative measures in various operations, providing training to the members, assisting entrepreneurs in obtaining industrial finance and extending support in the establishment of specialized industrial zone for attaining long term developmental objectives.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.2
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• pp.121-126
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• 2006

A gasoline-fueled stratified charge compression ignition (SCCI) engine with both direct fuel injection and intake temperature and compression ratio was examined. The fuel was injected directly by using the high temperature resulting from heating intake port. With this injection strategy, the SCCI combustion region was expanded dramatically without any increase in NOx emissions which were seen in the case of compression stroke injection. Injection timing during the intake temperature was found to be an important parameter that affects the SCCI region width. The effect of mixture stratification and the effect of fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.675-680
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• 2006

In the direct injected gasoline engine, atomized spray is desired to achieve efficient mixture formation needed to good engine performance because the injection process leaves little time for the evaporation of fuels. Therefore, substantial understanding of global spray structure and quantitative characteristics of spray are decisive technology to optimize combustion system of a GDI engine. The combustion and emission characteristics of gasoline-fueled stratified-charge compression ignition(SCCI) engine according to intake temperature and compression ratio was examined. The fuel was injected directly to the cylinder under the high temperature condition resulting from heating the intake port. With this injection strategy, the SCCI combustion region was expanded dramatically without any increase in NOx emissions, which were seen in the case of compression stroke injection. Injection timing during the intake temperature was found to be an important parameter that affects the SCCI region width. The mixture stratification and the fuel reformation can be utilized to reduce the required intake temperature for suitable SCCI combustion under each set of engine speed and compression ratio conditions.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.101.2-102
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• 2003

The ability of P. chlororaphis O6 to induce resistance to Erwinia carotovora subsp. carotovara SCCI and to promote growth in tobacco was demonstrated in microtiter assays on plants pre-inoculated at the root level with the bacteria before challenge with the leaf pathogen. To identify th bacterial determinants involved in induced systemic resistance and plant growth promotion, cell culture of O6 grown in King's medium B was fractionated with organic solvents and purified using various columns. in vivo and in vitro assays with samples from successive fractionation steps of the O6 supernatant led to the conclusion that antibacterial compounds were observed in aqueous layer, and to the isolation of fractions containing metabolites that retained most of the resistance-inducing activity (70：30, methanol：water) and the plant growth promotion (80：20 and 90：10, methanol：water) after ODS column chromatography. Although these molecules remain to be purified further and structurally characterized, its isolation is an addition to the range of determinants from plant growth-promoting rhizobacteria known to stimulate plant defence.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.8
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• pp.672-679
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• 2007

The combustion characteristics of a liquefied petroleum gas-di-methyl ether (LPG-DME) compression ignition engine was investigated under homogeneous charge and stratified charge conditions. LPG was used as the main fuel and injected into the combustion chamber directly. DME was used as an ignition promoter and injected into the intake port. Different LPG injection timings were tested to verify the combustion characteristics of the LPG-DME compression ignition engine. The combustion was divided into three region which are homogeneous charge, stratified charge, and diffusion flame region according to the injection timing of LPG. The hydrocarbon emission of stratified charge combustion was lower than that of homogeneous charge combustion. However, the carbon monoxide and nitrogen oxide emission of stratified charge combustion were slightly higher than those of the homogeneous charge region. The indicated mean effective pressure was reduced at stratified charge region, while it was almost same level as the homogeneous charge combustion region at diffusion combustion region. The start of combustion timing of the stratified charge combustion and diffusion combustion region were advanced compared to the homogeneous charge combustion. It attributed to the higher cetane number and mixture temperature distribution which locally stratified. However, the knock intensity was varied as the homogeneity of charge was increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.78-85
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• 2008

The exhaust emission characteristics of a liquefied petroleum gas-di-methyl ether (LPG-DME) compression ignition engine was investigated under homogeneous charge, stratified charge and diffusion combustion conditions. LPG was used as the main fuel and injected into the combustion chamber directly. DME was used as an ignition promoter and injected into the intake port. Different LPG injection timings were tested to verify the combustion characteristics of the LPG-DME compression ignition engine. The combustion was divided into three region which are homogeneous charge, stratified charge, and diffusion combustion region according to the injection timing of LPG. The HC emission was reduced with LPG stratification. However, the carbon monoxide and particulate matter emissions were increased. The ignition timing was advanced with LPG stratification. This advance combustion was because of charge temperature and cetane number stratification with LPG.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.220-227
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• 2014

The GacS/GacA system in the root colonizer Pseudomonas chlororaphis O6 is a key regulator of many traits relevant to the biocontrol function of this bacterium. Proteomic analysis revealed 12 proteins were down-regulated in a gacS mutant of P. chlororaphis O6. These GacS-regulated proteins functioned in combating oxidative stress, cell signaling, biosynthesis of secondary metabolism, and secretion. The extent of regulation was shown by real-time RT-PCR to vary between the genes. Mutants of P. chlororaphis O6 were generated in two GacS-regulated genes, trpE, encoding a protein involved in tryptophan synthesis, and prnA, required for conversion of tryptophan to the antimicrobial compound, pyrrolitrin. Failure of the trpE mutant to induce systemic resistance in tobacco against a foliar pathogen causing soft rot, Pectobacterium carotovorum SCCI, correlated with reduced colonization of root surfaces implying an inadequate supply of tryptophan to support growth. Although colonization was not affected by mutation in the prnA gene, induction of systemic resistance was reduced, suggesting that pyrrolnitrin was an activator of plant resistance as well as an antifungal agent. Study of mutants in the other GacS-regulated proteins will indicate further the features required for biocontrol-activity in this rhizobacterium.