• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.205-206
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• 2016

This study examines the effect of binding material and alkali activator on the rheology characteristics of alkali active mortar quantitatively, and a result is as follows. In the 1/2 slump flow, the higher mixing ratio of the fly ash has been shown to increase the table flow. the reason is that fly ash ball bearing action. When viewed in the consistency curve, the higher mixing ratio of the blast furnace slag powder was higher shear stress.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.747-755
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• 2006

This study evaluated the microbiological hazard of three Korean rice cake products (Gaepidduk, Injulmi, Julpyon). Microorganisms testing was conducted in various phases of the product flow of Korean rice cakes preparation, food equipment, environment work and cook employees at small scale. The results showed the presence of redbean paste, soybean powder and oil at levels as high as $10^5$ CFU/g on the hazard analysis of rice cakes ingredients. High levels of coliforms were detected in Julpyon products after 24 hr. and on the cooker's aprons. Clinical bacteria were not detected in any of the rice cakes. We concluded that there is a strong requirement for education related to personal hygiene for the production of hygienic rice cake products and for the publics health.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.45-48
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• 2005

Self compacting concrete has the strong point in capability of concrete to be uniformly filled and compacted in every corners of formwork by its self-weight without vibration during placing. However, powder type self compacting concrete has the weak point in the heat of hydration, the drying shrinkage and the elastic property of concrete etc. Recently viscosity agent has been developed in order to overcome these weaknesses. In this study, self compacting concrete is made with viscosity agent based on polysaccharide derivative in order to develope the normal strength self compacting concrete. Slump flow, loss of slump flow and setting time are measured for comparison with normal concrete. Compressive strength, freezing and thawing test and carbonation test are conducted on normal and self compacting concrete using viscosity agent. In the experiment, we acquired good results in fresh and hardened self compacting concrete using viscosity agent based on polysaccharide derivative.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3571-3574
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• 2011

Nano-scaled metal oxides have been attractive materials for sensors, photocatalysis, and dye-sensitization for solar cells. We report the controlled synthesis and characterization of single crystalline $TiO_2$ nanowires via a catalyst-assisted vapor-liquid-solid (VLS) and vapor-solid (VS) growth mechanism during TiO powder evaporation. Scanning electron microscope (SEM) and transmission electron microscope (TEM) studies show that as grown $TiO_2$ materials are one-dimensional (1D) nano-structures with a single crystalline rutile phase. Also, energy-dispersive X-ray (EDX) spectroscopy indicates the presence of both Ti and O with a Ti/O atomic ratio of 1 to 2. Various morphologies of single crystalline $TiO_2$ nano-structures are realized by controlling the growth temperature and flow rate of carrier gas. Large amount of reactant evaporated at high temperature and high flow rate is crucial to the morphology change of $TiO_2$ nanowire.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2423-2428
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• 2008

A turbo classifier having a rotating rotor of two stage classification region has been developed to have a cut size of 1 micro meter. Particle number concentrations were counted using Aerosol Particle Sizer (APS, TSI co., USA) at inlet and outlet of the classifier. Partial classification efficiency was obtained at various rotation speeds, total flow rates, and feed rates of powders, and classification characteristic depending on design parameters was discussed. Classification performance was enhanced as rotation speed of rotor increased and total flow rate decreased.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.727-730
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• 2004

The purpose of this study is to evaluate the fundamental properties of fine type cement grouts with redispersible polymer powders. Cement grouts with redispersible polymer powders are prepared with various polymer-cement ratios, and tested. for flow, water absorption, drying shrinkage, flexural and compressive strengths. From the test results, flow of the cement grouts with EVA and Va/VeoVa polymer powers decreased with increasing elapsed time. Regardless of polymer type, the flexural strength of the cement grouts tends to increase with increase in polymer-cement ratio. The maximum compressive strengths of the cement grouts are obtained at a polymer-cement ratio of $5\%$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.177-185
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• 1999

In this study, study about fly ash and blast-furnace slag used as substitutive materials for cement, and the influence on the neutralization of high flow concrete durability with these substitutive materials was performed and analyzed. The results are as follows 1) Aggregate segregation was partially improved with the progress of the admixture input at the mix proportion above slump flow 65 cm 2) Compressive strength with the progress of the increasement of fly ash input was decreased in early age, but decrease range was improved in long term age. Also, in case of blast-furnace, similar or improved compressive strength was appeared. 3) The neutralization depth with fly ash input was noticeably increased. But blast-furnace slag was effective to prevent. 4) In this experiment, high powder content was advantageously affected on preventive effect of the neutralization, and the relationship between the compressive strength and the neutralization depth was inversely proportional.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.696-702
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• 2007

The effect of different steamed garlic powder concentrations on sponge cake quality were investigated by analyzing both physicochemical and sensory properties. The sponge cakes were mixed with either steamed and freeze-dried garlic powders at different ratio [0, 2, 4, 6, 8 and 10 % (w/flow w)]. The density of the prepared dough increased with increasing amounts of steamed garlic powder when the concentrations were over 4%. The heights of the sponge cakes ranged from $3.53{\pm}0.12{\sim}3.60{\pm}0.15cm$ in the $4{\sim}8%$ steamed garlic powder samples, and were significantly higher than the control. The specific loaf volume of the cake was $3.86{\pm}0.07mL/g$ the highest in the 4% steamed garlic powder samples. When the garlic powder concentration was over the 6%, the specific loaf volumes of the sponge cakes decreased with increases in garlic powder contents. The measured L- and b-values of the crust were significantly decreased with increasing garlic powder concentration while the a-value gradually increased. The L-value of the crumb increased with increasing steamed garlic powder concentration, especially at concentrations greater than 4%. The a-values were higher in the steamed garlic powder treatments than in the control. however, no significant differences were found in the concentrations over 4%. The hardness of the control was $812.42{\pm}56.69g/cm^2$, whereas it ranged from $1005.36{\pm}43.65{\sim}1522.78{\pm}204.95g/cm^2$ in the experimental groups. Hardness increased with increasing garlic powder concentration. When considering moistness, overall acceptability, and other characteristics, the optimal concentration of steamed garlic powder was found to be 4%.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.118-121
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• 2007

Bulk metallic glass (BMG)/crystalline composites comprising a copper based BMG alloy and crystalline nickel were produced by means of eloctroless plating of nickel on $Cu_{54}Zr_{22}Ti_{18}Ni_6$ BMG powder and subsequent consolidation using spark plasma sintering. The plastic deformation behavior of BMG/crystalline composites was examined by uniaxial compression test at various temperatures in the supercooled liquid region (SLR) of the BMG alloy. The evolution of strain states during uniaxial compression was tackled by microstructure observations. Deformation temperature played an important role in the deformation behavior of BMG/crystalline composites, which was attributed to a strong temperature dependence of the flow stress of the BMG alloy in the SLR. BMG/crystalline composites deformed homogenously in the temperature range where the flow stress of the BMG alloy was close to that of crystalline nickel. In contrast, inhomogeneous deformation was observed in the temperature range where the flow stress of the BMG alloy largely differs from that of crystalline nickel.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.721-727
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• 2006

This study was carried out to investigate the effect of hydrocolloids on the changes in physical properties of a model ice cream. The model ice cream contained water, sugar, skin milk powder, com oil, and 4 different hydrocolloid stabilizers (gelatin, pectin, hydroxyethylstarch, locust bean gum), was manufactured in a batch type freezer. The following physical characteristics of ice cream were examined: flow behavior, overrun, air cell size, ice crystal size, and melt resistance. With regard to flow behavior, all of aged mixes had a lower apparent viscosity relative to the mix before aging, and ice cream mix containing locust bean gum had the highest viscosity. Air cell size was observed to range from 20 to $38\;{\mu}m$, and ice cream with locust bean gum showed the largest size. There was an inverse correlation between overrun and air cell size. The ice crystal sizes of all samples ranged from 25 to $35\;{\mu}m$. Ice cream with added pectin contained the smallest ice crystal size, which was significantly difference from other stabilizers (p<0.05), and resulted in superior melt resistance with increased melting time compared to other samples.