• The Korean Journal of Community Living Science
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• v.26 no.1
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• pp.127-133
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• 2015

This study identifies the factors improving bread quality by using fermented liquid dough. Fermented liquid dough, the main part of bread dough, contains yeasts that are prepared in order to enhance the fermentation rate. This study investigates the fermentation rate after mixing dough, the pH of dough, loaf volume, water activity, hardness, and sensory properties of loaf bread samples with different amounts of fermented liquid dough. The fermentation rate was slightly higher in the bread samples, the control dough and 10% fermented liquid dough, than in samples with more than 20% dough. The pH values of dough decreased with an increase in the content of fermented liquid dough. The loaf volume of bread with 10% fermented liquid dough was the highest. The water activity of loaf bread increased with an increase in amount of fermented liquid dough. For the sensory evaluation of loaf bread, adding 10% fermented liquid dough improved the loaf volume and evenness of baking. These results suggest that 10% fermented liquid dough increased the fermentation rate and bread quality. Further research is required to enhance internal quality characteristics of loaf bread, including taste and flavor.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.102-109
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• 1994

As a fundamental study to apply high pressure injection system to direct injection diesel engine, fuel injection system and constant volume combustion chamber were made and the behaviors of evaporating spray with the variation of injection pressure and the ambient gas temperature were observed by using high speed camera, and the combusion characteristics with the variation of injection pressure and A/F ratio were analyzed. As injection pressure increases, spray tip penetration and spray angle increase and, as a results spray volume increases. This helps an uniform mixing of fuel and air. Spray liquid core length decreases as ambient gas temperature increases, while it decreases as injection pressure increases but the effect of ambient gas temperature is dorminant. As injection pressure increases, ignition delay is shortened and combustion rate being raised, maximum heat release rate increases. It become clear that High injection pressure has high level of potential to improve the performance of DI-diesel engine.

• KSTLE International Journal
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• v.2 no.2
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• pp.103-113
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• 2001

The influence of aerated oil on high-speed journal bearing is examined by classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The live oil surface tension is considered as functions of temperature, API gravity and air volume ratio. With changing eccentricity ratio, it is investigated the effects of air bubbles on the performance of a high-speed plain journal bearing. Just at the moderate eccentricity ratios, even if the involved aeration levels are not so severe and the entrained air bubble sizes are not so small, it is found that the bearing load and friction farce may be changed so visibly for the high speed bearing operation.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.4
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• pp.413-422
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• 2005

The ozone concentration measured by HALOE (Ver 19) from Oct. 1991 to Dec. 2003 is used for analyzing the variation of ozone concentration. The HALOE loaded in UARS is observing several gases in the atmosphere, from 10km to 80km. Fourier analysis of these data in the middle latitude northern hemisphere is reported in this paper. To detect any possible long term trends, the fourier transformed time series was back transformed after removing signals with time periods of less than 6 months. Although the results clearly show the strong annual cycle, it is difficult to show any long term trends from the fourier series. We also compared the ozone volume mixing ratio's from HALOE with that from the ground-based radiometry to evaluate the accuracy of microwave observation at Sookmyung Women's University.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.99-104
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• 1991

It is necessary to generalize the use for structural ALA Concrete in our country, as increasing in the need for the development of ALA and the use of ALA Concrete which is related with the diminution of the self load and foundation section of structure responding to the realistic requirement against the decrease of natural aggregate and the high-rising and large-sizing of structures. This little study, therefore intended to help in the mixing design of concrete by considering the fundamental properties of ALA Concrete used with expanded clay, which is considered by acopting the experimental factors such as unit cement content, water cement ratio and the rate of fine aggregate. By considering the results of this experiment, it has difficulty in getting expected slump with the unit water content of normal concrete because of the large absorption of lightweight aggregate, and because the weight of unit volume and specific gravity ALA Concrete are small it appears that the strength and Elastic Modulus of that are small too and that it is more ductile than normal concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.631-636
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• 2002

This study shows basic data for using as the structural lightweight aggregate. This will be the procedural method of recycling environmental close waste PET bottle lightweight aggregate(PBLA) that is rapidly increased the amount of production of waste PET bottle recently, the quality of developed PBLA and the fundamental properties by analyzing of mortar containing with PBLA. After experiment, the result shows the PBLA quality that have oven dry specific gravity of 1.39, unit volume weight of 844 kg/m$^3$ and absorption rate of 0% is satisfied with qualify regulation of lightweight aggregate. The flowability of mortar containing PBLA is increased maximum 16% with increasing mixing ratio of PBLA, however the compressive strength of mortar is decreased maximum 35% with increasing mixing ratio of PBLA.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.145-147
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• 2009

Nutrients in wastewater should be removed prior to release in the receiving waters to prevent the occurrence of eutrophication. In this study, seawater is used to remove ammonia and phosphate by the formation of struvite ($MgNH_{4}PO_{4}{\cdot}6H_{2}O$). It aims to know the optimum conditions for the removal of nutrients using seawater as source of magnesium ions. Experiments were performed using jar tester and pH of ammonium-phosphate solutions were adjusted Samples were drawn at different mixing times. It was shown that simultaneous removal of ammonia and phosphate is rapid, with no significant reduction beyond 10 min of mixing Another important parameter is pH, where range 10-11 showed the optimum nutrient removal. Increase in the volume of seawater, which meant an increase in magnesium ions also lead to better removal.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.253-256
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• 2000

The functions of porous concrete were influenced by continuous void, and it differ greatly from the distribution and size shape of continuous void in the same void volume. And porous concrete has been few used because the strength level of porous concrete is lower than that of ordinary concrete at the present time. So the purpose of this study is to increase the strength of porous concrete at the range of satisfying its function, analyze those effects of the mixing ratio of aggregate, affecting the development of its strength.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.17-21
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• 1999

The baking property, chemical composition, instrumental characteristics and sensory quality of yeast breads containing various mixing percentage of Job's-tears flour with wheat flour were studied. The loaf volume and baking quality of the yeast bread made from mixing of 30% Job's-tears flour were similar to those of wheat flour bread. The contents of crude protein, crude fat, and crude ash in Job's-tears flour breads were much higher than those of wheat flour brad. Instrumental rheological characteristics of the yeast breads were measured with a Texture Analyzer. As the addition level of Job's-tears flours increased, hardness of the yeast breads increased but fracturability, adhesiveness, springness, cohesiveness, gumminess, chewiness and resilience decreased. The results of sensory evaluation revealed that Job's-tears flour was added to wheat flour at a replacement level of 10% without a large adverse effect on flavor, taste, mouthfeel and aftertaste.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.218-219
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• 2018

This study analyzed the unit weight and compressive strength properties of lightweight concrete using high volume blast furnace slag powder by the mixing ratio of lightweight coarse aggregate to investigate the properties of lightweight concrete using domestic artificial lightweight aggregate.