• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.214-221
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• 2018

In this paper, the effects of ferronickel slag powder and admixture on the strength of VR sewer pipe were analyzed. the substitution rate was tested as a variable, and the strength development was studied through the flexural strength, compressive strength and using SEM microscopic analysis. bending strength, compressive strength results and micro analysis using SEM showed the correlation in each case. the substitution rates were 20% and 30% relative to the mass of the OPC respectively, and were substituted according to a constant ratio of ferronickel slag fine powder and mixture. when the substitution ratio was 20%, the strength development was excellent. also, bending strength and compressive strength were the best when the ferronickel slag fine powder, quicklime, gypsum and calcium chloride were used as the admixture, dense microstructural patterns appeared. the possibility of progressive strength development is shown after 28 days.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.88-94
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• 2011

To make recycling aggregate, quantity of fine particles increase due to multi-crushing. Though this particles were mixed with recycling aggregate, those have to be disparted from aggregate in the high quality recycling aggregate, because of the cause of low quality. Considering reactivity, fine particles is better than coarse one. Therefore, it needs to develop suitable usage. We try to make cement extruding material by using the fine particles from concrete recycling, as a silicious replacement. Test results are as follows ; 1) Waste concrete powder has major ingredients such as $SiO_2$ and CaO, its density is $2.45g/cm^3$ being similar to silica powder, its diameter is range 13 to $141{\mu}m$. 2) Considering to strength properties according to particle size, specimen was made using small particles is higher strength than large one. 3) Despite of exception in the autoclaved curing, when the replacement of waste fine particle increase, strength of extruding panel shows almost same level.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.317-322
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• 2005

Nowadays, recycling of aggregates from the waste concrete is in big demand due to the protection of environment and the shortage of aggregates that are needed for ever expanding construction projects. This study was undertaken to examine the feasibility of recycling waste concrete powder produced in the crushing process of demolished concrete as a filler material for polymer mortar. In this study, polymer mortar specimens were prepared by varying the mix proportion of polymer binder (ranging 9~15 wt%), waste concrete powder (ranging 0~20 wt%) substituted for silica powder, 0.1~0.3 mm fine aggregate (ranging 21~24 wt%) and 0.7~1.2 mm fine aggregate (ranging 44~47 wt%). For the prepared polymer mortar specimens, various physical properties such as strength, water absorption, heat water resistance, acid resistance, pore distribution and SEM observation were investigated in this work. As a result, physical properties of polymer mortar were observed to have remarkably improved with an increase of polymer binder, but greatly deteriorated with an increase of substitution quantity of waste concrete powder.

• Food Engineering Progress
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• v.23 no.3
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• pp.217-222
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• 2019

The purpose of this study is to investigate the effect of ultra-fine powder kelp powder as a natural food additive for fast rehydration on the quality of freeze-dried fish cake noodle with soft and elastic texture properties during or after cooking. The average moisture content and water activity ranges of freeze-dried fish cake noodle were 3.71±0.12% (dry basis) and 0.185-0.332, respectively. The water activity of freeze-dried fish cake noodle decreased upon increasing the kelp powder content at the same moisture content. The rehydration ratios of fish cake noodle with 1, 3, and 5% (w/w) of kelp powder were 1.39, 1.49, and 1.77 g water/g solid, respectively. The hardness of the 5% (w/w) kelp powder-enhanced fish cake noodle after rehydration had the lowest value among the three samples upon using a texture profile analysis test (TPA). In the sensory hedonic test results, 5% (w/w) kelp powder added to fish cake noodle after rehydration produced the highest values in texture, flavor, and overall quality.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1605-1610
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• 2012

Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of $300{\mu}m$, 0.8% red pepper powder processed as a super fine powder with a vibrational mill ($44{\mu}m$) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% $Na_2CO_3$ either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p<0.05) for birds fed 1.2, 2.4 or 9.6 ppm red pepper pigment than for birds fed the diet containing 0.3 ppm red pepper pigment. On d 14, egg color scores increased linearly as the level of red pepper pigment in the diet increased. In Exp. 2, feeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05). All the red pepper powder treatments also increased (p<0.05) the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

• Journal of Powder Materials
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• v.16 no.5
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• pp.310-315
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• 2009

Ultra-fine TiC/Co composite powder was synthesized by the carbothermal reduction process without wet chemical processing. The starting powder was prepared by milling of titanium dioxide and cobalt oxalate powders followed by subsequent calcination to have a target composition of TiC-15 wt.%Co. The prepared oxide powder was mixed again with carbon black, and this mixture was then heat-treated under flowing argon atmosphere. The changes in the phase, mass and particle size of the mixture during heat treatment were investigated using XRD, TG-DTA and SEM. The synthesized oxide powder after heat treatment at 700$^{\circ}C$ has a mixed phase of TiO$_2$ and CoTiO$_3$ phases. This composite oxide powder was carbothermally reduced to TiC/Co composite powder by the solid carbon. The synthesized TiC/Co composite powder at 1300$^{\circ}C$ for 9 hours has particle size of under about 0.4 $\mu$m.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.383-388
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• 2019

High purity SiC fine powder with metal impurity contents of less than 1 ppm was synthesized by improved carbothermal reduction process, and the synthesized powder was used for SiC single crystal growth in RF heating PVT device at temperature above 2,100℃. In-situ x-ray image analyzer was used to observe the sublimation of the powder and single crystal growth behavior during the growth process. SiC powder was used as a source of single crystal growth, exhausted from the outside of the graphite crucible at the growth temperature and left graphite residues. During the growth, the flow of raw materials was concentrated in the middle and influenced the growth behavior of SiC single crystals. This is due to the difference in temperature distribution inside the crucible due to the fine powder. After the single crystal growth was completed, the single crystal ingot was cut into a 1 mm thick single crystal substrate and finely polished using a diamond abrasive slurry. A dark yellow 4H-SiC was observed overall of single crystal substrate, and the polycrystals generated in the outer part may be caused by the incorporation of impurities such as the bubble layer mixed in the process of attaching the seed crystal to the seed holder.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.47-50
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• 2007

This study investigates the properties of light weight foamed concrete (LWC) designed with various content of fine grains (FG). Test showed that LWC containing diverse powder materials with addition, more than 15% of FG, tended to decrease the fluidity of fresh concrete. 10% of FG content in LWC exhibited 4mm in sinking depth, which is the lowest value. This value dramatically increased at more than 15% of addition. However the concrete incorporating LSP proportionally increased the sinking depth in overall. As for the strength, the values of all specimens were under standardization of KS, except for the concrete adding 5 and 10% of FG. Apparent density of LWC showed the lowest value when used 10% of FG which was satisfied the 0.5 grade in KS. For the thermal conductivity, it was also indicated at 0.5 grade in KS, which is under $0.160W/(m{\cdot}k)$. In conclusion, it is demonstrated that adding 10% of FG in LWC was effective in the aspects of recycling of materials, cost effectiveness and quality.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.197-198
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• 2023

This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.474-475
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• 2007

Wire electrical explosion(WEE) has been used for the production of fine metal particles. In WEE, electrical powder was stored and compressed into capacitor and released to produce fine particles through evaporation and condensation. In this study, the effect of applied voltage on the size of copper powders was investigated. High tension was added up to the explosion device by dividing 4 steps. At voltages lower than 5.2 kV, the fraction of powders finer than $44{\mu}m$ was almost negligible. The effectiveness of explosion increased sharply with increased voltage over 5.8 kV. At the highest voltage of 6.4 kV, more than 80% of explosion products were finer than $44{\mu}m$.