• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.341-344
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• 2006

The waste glasses among plenty of wastes put out lately is limited in recycling and reusing, and the phenomenon hasn't been improved quite much. And besides, the recycling rate shows the 70.1%, relatively low. These waste glasses is currently used for road pavement materials, interior and exterior decorating materials in architecture, road painting meterials, auxiliary lagging materials for heat-retaining, coldness-retaining and soundproofing, and glass bottles. 30% of waste glasses powder is, however, not reused pratically. Therefore, in this research, we operated some tests including flow of mortar mixed with waste glasses powder, setting time, rheology and compressive strength to utilize waste glasses powder put out in the precess of recycling for admixture for repair mortar. As a result, we've found out that we can utilize waste glasses powder for admixture for repair mortar.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.55-56
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• 2011

This study is to investigate the engineering properties of low heat concrete incorporating improved ternary blended cement by combining OPC(original portland cement), blast furnace slag and fly ash. The results were summarized as following ; For ITB(Improved Ternary Blend)mixture was that setting time proved to be accelerated, and adiabatic temperature rises were low. The use of ITB resulted in an increase of initial compressive strength.

• Journal of the Korean Ceramic Society
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• v.34 no.4
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• pp.399-405
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• 1997

With the increase of ZnO content, heat of hydration decreased. For specimens containing ZnO more than 0.6 wt.%, the compressive stength of cement cured for 28 days could not be measured because setting was not occurred. With the increase of ZnO content, Blaine specific surface area of cement was decreased and the residue of 45 ${\mu}{\textrm}{m}$ and 90 ${\mu}{\textrm}{m}$ was increased when cement was ground. That is, grindability became worse as ZnO increased in clinker. The difference of color as a function of ZnO content could not be observed, but in the excess of amount of ZnO added, color became more white and reddish yellow.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.109-114
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• 2010

In a fan design, CFD analysis, which is very useful for mechanical design relating to the heat and fluid dynamics, is one of the most popular tools. However, since the CFD analysis is conventionally carried out with the constant fan speed condition, the speed change, induced by the air flow rate and motor characteristics, is hardly modeled. And, consequently, the remarkable difference exist between analysis and experimental results. In this paper, we has proposed a method of setting the varying fan speed as a boundary condition considering air flow rate and motor torque-speed characteristics. The effectiveness of the proposed method is verified by comparison with experimental results.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1418-1423
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• 2009

This study describes experimental study on the performance characteristics with load condition in hybrid solar heating system during spring season. The room temperatures, the hot water conditions and the lower part temperatures of heat storage tank were changed to analyze the system performances. As a results, the hot water was significantly affected by the ambient temperature. The indoor setting temperature affected the solar fraction. When the low part temperature of the storage tank increased, the temperature of the hot water rose and the temperature of the hot water in morning was affected by the ambient temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.195-198
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• 2000

Recently, the anriwashout underwater concrete has been increasingly used for underwater structures such as vary high diaphrame walls of high strength massive concrete structures. In this study, experiments were made on the fundamental properties of antiwashout underwater concrete replaced with Fly Ash from 10% to 30% to improve its properties. Resultant to the test, we got the results as follows; the value of slump flow wasi ncreased, the setting, time was very delayed, and the heat evolution amount decreased, whereas the amount of suspended solids became high, and pH value became low as to increasing the replacement ratio of Fly Ash. Also the ratios of compressive strength (in water compared to in air) at 28day were obtained over 90%, and these values were satisfied with 70% of a criterion.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.150-151
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• 2016

In previous study, researchers studied development of early anti-freezing cement at low temperature (-5℃) using hydration characteristics of reduction slag. In this study, the durability of concrete using reduction slag was conducted. The experiment result, reduction slag makes high temperature and improves compressive strength due to quick setting. And then result of durability show that it is no problem. However, it is considered that further study is needed about high shrinkages which was indicated in dry shrinkage.

• Journal of Welding and Joining
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• v.11 no.1
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• pp.42-51
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• 1993

In this study, investigations were conducted in calculating parameters of elastic-plastic fracture mechanics using single specimen. The validity of these testing methods was judged by the confirmation of multiple specimen method of stop block test. The results were as follows: In order to measure a fracture toughness using the instrumented impact test, two general requirement must be considered; One, setting up proper impact velocity considered the effect of loading and the other, the necessity of low blow test for obtaining true energy by the compliance correction. It was possible to detect a crack initiation point by calculating the compliance changing rate from a load-defection curve. Criterion of a stable crack growth, $T_{mat}$ could be estimated by using key-curve method for a base metal. and combining Kaiser's rebound compliance with Paris-Hutchison's $T_{appl}$ equation for the brittled zone of welding heat affected.at affected.d.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.2
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• pp.47-52
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• 2013

Aim of this study is to investigate the dimensional and shrinkage characteristics of the weft knitted fabrics with Polylactic acid(PLA) knitted yarn. This PLA knitted yarn was made of the biodegradability fiber. The structure of weft knitted fabrics that was utilized for this study is the plain stitch, which is the most basic structure among all weft knitted fabrics. As the stitch length is shorter, the stitch density, courses density, and wales density are more increasing. The stitch density increased as pre-treatment process and dyeing process progressed. On the contrary, the heat setting process made it decreasing. The MR(Machine Relaxation) and DR(Dry Relaxation) standard area shrinkage were increasing as wet process progressed and as the stitch lengths are long.

• Textile Coloration and Finishing
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• v.20 no.1
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• pp.36-43
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• 2008

False twist texturing uses the thermoplastic property of synthetic yarn and produces a bulk and a stretch by giving the filament a permanent crimp. This study investigated the effects of false twist texturing parameters, disk/yarn(D/Y) and heater temperature, on the physical properties of nylon textured yarn. D/Y was a primary determinant of twist numbers of filaments and was proportionally increased with the twist numbers of filaments, resulting in an increase of crimp rigidity of the textured yarn. Heater temperature, a determinant of the heat setting of transformed filaments, was proportionally increased with the increase of crimp rigidity. Nylon 6 was partially melted at $190^{\circ}C$. This study consequently suggested the optimal parameters of nylon 6 85d/68f full-dull POY.