• 한국대기환경학회지
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• 제24권1호
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• pp.55-62
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• 2008

This study is aimed at substantially reducing the particulate matter (dust) emission during the combustion of heavy fuel in boilers by addition of combustion improver. The combustion improver used were the oil-soluble organometallic compounds that were found to be more effective than the dispersing agents that are generally used for reducing the particulate emission. The dust reduction effect was found to depend on the active materials (metals) as well as on the organic ligand part of organometallic compounds. Acetylacetonoate and naphthenate of Fe and Ca were found to be most effective for dust reduction. Addition of Fe and Ca organometallic compounds as combustion improver in concentration of 30 ppm (metal basis) to heavy fuel oil, caused dust reduction by 50 wt% to 80 wt%.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.178.1-178.1
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• 2011

DME is generally expected to be used as a promising clean alternative fuel to diesel fuel. DME is not natural product but a synthetic product that is produced either through the dehydration of methanol or a direct synthetic from syngas. As DME has no carbon-carbon bond in its molecular structure and is an oxygenate fuel, it's combustion essentially generates no soot. DME has such cetane number of 55~60 that it can be used as a diesel engine fuel. However, DME has low lubricity but a proven method to solve the poor lubricity is by adding lubricity improver. Therefore, the aim of this study is to develop lubricity improver of DME as a transport fuel in Korea. In this study, we investigated a possibility of fatty acid ester compounds as a candidate to improve DME lubricity as compared with current lubricity improver of diesel. We also evaluated quality characteristics, storage stability of DME with lubricity additives.

• Korea-Australia Rheology Journal
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• 제15권3호
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• pp.117-124
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• 2003

Elastohydrodynamic lubrication (EHL) film is measured under the condition of viscosity index improver added to base oil. In-situ optical contact method using the interference principle make the measuring resolution of ~5 nm possible and enables the measuring range all over the contact area of up to ~300 $\mu\textrm{m}$ diameter. What is more important to the developed method by the author is that the measurement of EHL film thickness is possible in the range from 100 nm to 2 $\mu\textrm{m}$, which is the regime of worst contact failures in precision machinery. Viscosity index improver (VII) is one of the major additives to the modem multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate (over $10^5 s^{-1}$) of general EHL contact regime. In order to exactly verify the VIIs performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to ~100 nm with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of ~5 nm, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

• International Journal of Automotive Technology
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• 제6권1호
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• pp.15-21
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• 2005

The purpose of this paper is to experimentally investigate the engine pollutant emissions and combustion characteristics of diesel engine fueled with ethanol-diesel blended fuel (bio-diesohol). The experiments were performed on a single-cylinder DI diesel engine. Two blend fuels were consisted of $15\%$ ethanol, $83.5\%$ diesel and $1.5\%$ solublizer (by volume) were evaluated: one without cetane improver (E15-D) and one with a cetane improver (E15-D+CN improver). The engine performance parameters and emissions including fuel consumption, exhaust temperature, lubricating oil temperature, Bosch smoke number, CO, NOx, and THC were measured, and compared to the baseline diesel fuel. In order to gain insight into the combustion characteristics of bio-diesohol blends, the engine combustion processes for blended fuels and diesel fuel were observed using an Engine Video System (AVL 513). The results showed that the brake specific fuel consumption (BSFC) increased at overall engine operating conditions, but it is worth noting that the brake thermal efficiency (BTE) increased by up to $1-2.3\%$ with two blends when compared to diesel fuel. It is found that the engine fueled with ethanol-diesel blend fuels has higher emissions of THC, lower emissions of CO, NOx, and smoke. And the results also indicated that the cetane improver has positive effects on CO and NOx emissions, but negative effect on THC emission. Based on engine combustion visualization, it is found that ignition delay increased, combustion duration and the luminosity of flame decreased for the diesohol blends. The combustion is improved when the CN improver was added to the blend fuel.

• 한국식품영양학회지
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• 제24권4호
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• pp.567-576
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• 2011

A study was undertaken to examine the antioxidative activity and the quality attributes of broccoli stem powder pound cakes. Broccoli stem powder was added to the batter at a ratio of 5, 10 and 15% respectively. The antioxidant activity was estimated by DPPH free radical scavenging activity, the total phenolic compounds content and flavonoid content in Broccoli stem powder and pounds cakes. Antioxidative activity was highly correlated with the total phenolic and total flavonoids contents of broccoli stem pound cakes respectively($r$=0.937, $r$=0.981). The effect of cake improver on quality characteristics of cake broccoli stem powder and pound cakes were estimated in terms of the specific load volume, hardness, hunter value of crumb and crust and sensory quality of cakes. The specific volume were increased significantly with increasing substitution level of cake improver and broccoli stem powder($p$ <0.01). The lightness were significantly decreased with increases in broccoli stem powder of pound cake crust and crumb($p$ <0.01, $p$ <0.01). The hardness, chewiness and gumminess and cohesiveness were tended to reduce in both of powder. The consumer acceptability score for 5~10% broccoli stem pound cakes ranked significantly($p$ <0.01) higher than those of the other groups in taste, flavor and overall preference. This results showed that cake improver & broccoli stem powder are a good ingredient to increase consumer acceptability and the healthy.

• Tribology and Lubricants
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• 제30권3호
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• pp.189-198
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• 2014

This paper presents the results of an experimental investigation of the correlation between the lubrication characteristics of an engine and its fuel economy. Improving the lubrication characteristics of the engine oil is one of the most efficient ways to improve a car's fuel economy. The methods to accomplish this include lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver. In addition, it is necessary to use different methods to reduce the friction to individual lubrication areas, because different lubrication regimes are used for different engine parts. The experimental investigation in this study is based on design of experiments ; this paper presents the results of a modified Sequence VID test, which is an ASTM standard test used to measure the effects of automotive engine oils on the fuel economy of passenger cars. The results demonstrate the effects of the following lubrication factors on the fuel economy : the low temperature cranking viscosity, high-temperature high shear (HTHS) viscosity, friction modifier, polymer type and shear stability index of the viscosity index improver. Moreover, this study involves an analysis of variance based on design of experiments. The test results show that the HTHS viscosity, friction modifier and shear stability index of the viscosity index improver are more effective than the other factors. Therefore, lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver should be considered to improve fuel economy.

• 한국식품영양과학회지
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• 제28권6호
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• pp.1275-1282
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• 1999

To investigate the effect of flour brew with bifidobacteria on bread characteristics, flour brew with bifidobacteria was added to baking after 16 hour incubation at 37oC. The more addition of flour brew, the higher gassing power, the better machinality of dough were obtained, resulting in the larger specific volume of bread. Flavor profile analyzed by Electronic Nose System showed that flavor components of 30% flour brew were decreased comparing with those of control and there was shown definite difference in sensory characteristics between them. Staling studies of bread containing flour brew indicated had a definite effect in retarding the staling rate of bread, with time constant calculated in 30% treatment being 3.09 days and in control being 2.08 days. The enthalphy of gelatinization was decreased from 2.51J/g to 0.61J/g with increment of flour brew, suggesting that starch crystallization is delayed. conclusion, Flour brew fermented by bifidobacteria can be used as a natural bread improver with so many benefits as better machinality, one more day storage period, slower staling rate, better bread volume and more appealing bread flavor.

• The Korean Journal of Ecology
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• 제15권1호
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• pp.67-73
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• 1992

This study was carried out to investigate the effects of soil improver on the population density and composition of microarthropods in the upland which cultivated pepper consecutively. We have treated soil improver sucf as zeolite, compost, ca, sio2 , and integrated improvement i. e. treated zeolite, compost, ca, and deep cultivate ; 20 cm. We sampled soil to collect soil microarthropods from a week to 15 months after treament at each site by soil-corer and extracted 48 hours in berlese- tullgren funnel. We have classified 16 families, 35 species diversity index of soil microarthropods are highe in the integrated improver and compost site than those found in any other sites. We suggest that soil improvement effrcts of integrated improved site are influenced by compost.

• 한국고분자학회지:고분자과학과기술
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• 제7권2호
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• pp.201-209
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• 1996

• Tribology and Lubricants
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• 제15권3호
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• pp.248-256
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• 1999

Many tribological components in automobile engine undergo high load and sliding speed with thin film thickness. The lubrication characteristics of the components are regarded as ether hydrodynamic lubrication or boundary lubrication, whereas in a working cycle they actually have both characteristics. Many modem engine lubricants have various additives for better performance which make boundary film formation even under hydrodynamic lubrication regime. Conventional Reynolds equation with the viewpoints of continuum mechanics concerns only bulk viscosity of lubricant, which means that its simulation does not give insights on boundary lubrication characteristics. However, many additives of modern engine lubricant provide mixed modes of boundary lubrication characteristics and hydrodynamic lubrication. Especially, high molecular weight polymeric viscosity index improvers form boundary film on the solid surface and cause non-Newtonian fluid effect of shear thinning. This study has performed the investigation about journal bearing system with the mixed concepts of boundary lubrication and hydrodynamic lubrication which happen concurrently in many engine components under the condition of viscosity index improver added.