• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.05a
• /
• pp.93-97
• /
• 2008

The study analyzed on each kind of basic characteristics in mortar to prove an effect of pre-mix cement, ultra high strength binder. The results were as follows. in characteristics of not set mortar, fluidity time was the quickest at the time of using POBSA and was more delayed at the time of using Fly Ash than at the time of using Blast Furnace Slag as a binder. Mortar ring flow and flow con flow got smaller as fluidity time got longer, on the contrary to fluidity time. Unit capacity mass was smaller at the time of using Fly Ash than at the time of using Blast Furnace Slag. According to pre-mix, it was difficult to discover a regular tendency. In characteristics of hardening mortar, the 28th day compressive strength was better than thing mixed after measuring separately in pre-mix. According to a binder's kind, Silica Fume B, C was better than Silica Fume A.

• International Journal of Highway Engineering
• /
• v.19 no.2
• /
• pp.55-65
• /
• 2017

PURPOSES : This study aimed to analyze the experimental and numerical behavior of warm mix asphalt pavement prepared using steel slag and RAP and to conduct economic analysis of pavement construction. METHODS : For developing high performance asphalt pavement, we performed three evaluations: fundamental analysis, experimental testing, and 3D finite element analysis. In particular, 3D finite element analysis was conducted on several pavement structures by adopting the results of experimental tests. RESULTS : Through the various evaluations, it was established that steel slag was effective for use as asphalt mixture aggregate. Moreover, asphalt mixture constituting steel slag and RAP demonstrated higher performance behavior compared with conventionally used asphalt mixture. Furthermore, based on the 3D FE modeling, we established that the developed asphalt pavement constituting steel slag and RAP can be utilized for thin layer pavement with comparable performance behavior. CONCLUSIONS :Warm mix asphalt pavement prepared using steel slag and RAP is more competitive and economic compared to hot-mix asphalt pavement. Moreover, it can be applied for preparing thin layer asphalt pavements with reasonable performance. The developed warm mix asphalt pavement prepared using steel slag and RAP can be an alternative pavement type with competitive performance based on the reasonable economic benefit it provides.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.11a
• /
• pp.37-40
• /
• 2007

This study investigates the effect of the pre-mix cement to the physical properties of the concrete according to the various combinations of the binders and the silica fume types. The results are summarized as following. For the properties of the fresh, the fluidity in the case that OPC+cilica fume-blast-furnace slag is appropriate compared to OPC+cilica fume+fly ash. Expecially, it is favorable when pre-mix is used. The fluidity time of the A, B depending on silica fume types is favorable, but it is decreased on C. The air content depending on silica fume types is low when the fly ash is used. Specially, the air content in the case that pre-mix is used is low caused by the dispersion of the silica fume. For the properties of the hardened concrete, the compressive and flexible strength when the blast-furnace slag is pre-mixed are high, and they exceed OPC. The strength depending on the silica fume types is high on B, and the strength of the others is similar.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.7
• /
• pp.1233-1241
• /
• 2017

The ginsenoside Rh2 has strong anti-cancer, anti-inflammatory, and anti-diabetic effects. However, the application of ginsenoside Rh2 is restricted because of the small amounts found in Korean white and red ginsengs. To enhance the production of ginsenoside Rh2-MIX (comprising 20(S)-Rh2, 20(R)-Rh2, Rk2, and Rh3 as a 10-g unit) with high specificity, yield, and purity, a new combination of enzymatic conversion using the commercial enzyme Viscozyme L followed by acid treatment was developed. Viscozyme L treatment at pH 5.0 and $50^{\circ}C$ was used initially to transform the major ginsenosides Rb1, Rb2, Rc, and Rd into ginsenoside F2, followed by acid-heat treatment using citric acid 2% (w/v) at pH 2.0 and $121^{\circ}C$ for 15 min. Scale-up production in a 10-L jar fermenter, using 60 g of the protopanaxadiol-type ginsenoside mixture from ginseng roots, produced 24 g of ginsenoside Rh2-MIX. Using 2 g of Rh2-MIX, 131 mg of 20(S)-Rh2, 58 mg of 20(R)-Rh2, 47 mg of Rk2, and 26 mg of Rh3 were obtained at over 98% chromatographic purity. Then, the anti-cancer effect of the four purified ginsenosides was investigated on B16F10, MDA-MB-231, and HuH-7 cell lines. As a result, these four rare ginsenosides markedly inhibited the growth of the cancer cell lines. These results suggested that rare ginsenoside Rh2-MIX could be exploited to prepare an anti-cancer supplement in the functional food and pharmaceutical industries.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.11 no.1
• /
• pp.1604-1615
• /
• 1969

This experiment was carried out as one of the basic studies to improve the acid resistance of concrete and it was conducted to investigate some relations among physical properties such as basorption, ratio of water to cement, compressive strength, density and ratio of mix to weight losses of mortar when exposed to 0.1 N solution of hydrochrolic acid. The results obtained from the limited data secured so far in this experiment are summarized as follows: 1. The specimens used in the experiment were made of 5 cubic centimeters of mortar having such various ratios of mix by weight as 1 : 1, 1 : 3, 1 : 5, 1 : 7, 1 : 10. 2. Physical tests included compressive strengths at 7 days, 28 days, 3 months, and 6 month, and 5 hour boiling absorption test. 3. In acid test, every specimen was immersed into 0.1 N solution of hydrochrolic acid. The specimens exposed to the acid solution were weighed to determine the weight losses of the acid-corroded at one week interval for 7 weeks exposure, and the old acid solutions were also changed to fresh one when weighed the weight losses by acid attack at one week interval. 4. The correlative relations were found among physical properties and they are expressed by certain formulas as follows; i) Relation between ratio of mix and absorption Y = 1.036x + 13.53 where Y: absorption(%) X: ratio of mix ii) Relation between ratio of mix and ratio of water-cement Y = 0.204x + 0.214 where Y: ratio of water-cement. X: ratio of mix iii) Relation between ratio of water-cement and absorption Y = 5.01x + 12.53 where Y: absorption(%). X: ratio of water-cement iv) Relation between density and absorption Y = 50.6 - 0.0176X where Y: absorption(%). X: density($kg/m^3$) v) Relation between density and ratio of water cement Y = 7.2183 - 0.0033X where Y: ratio of water-cement . X: density($kg/m^3$) 5. After completing the acid exposure test the specimens were corroded and , the per cent ranges of weight losses varies from a minimum of 20.4 per cent at a 1 : 1 mix to a maximum of 92.0 per cent at a 1:10 mix 6. The correlative relations of physical properties of mortar to weight losses by acid attak were found and they are also expressed by certain formulas as follows: i) Relation between weight losses and ratio of mix Y = 8.59X + 8.63 where Y: weight losses(%), X: ratio of mix ii) Relation between wieght losses and absorption Y = 0.121x + 12.43 where Y: absorption(%). X: weight losses(%) iii) Relation between weight losses and ratio of w/c Y = 0.0226X + 0.07 where Y: ratio of w/c X: weight losses(%) iv) Relation between weight losses and compressive strength LogY = 3.6097 - 0.05058X + 0.00022$X^2$ where Y: compressive strength ($kg/cm^3$) X: weight losses(%) v) Relation between weight losses and density Y = 2153.1 - 6.62X where Y: density($kg/m^3$) X: weigh losses(%) 7. In order to make better acid resistant mortar, it could be concluded that a 1 : 3 mix or richer mixes, adequate mixing water to minnimize the ratio of water-cement considering the workability, 16 per cent or less absorption by 5 hour boiling water, 1,800 kilogram per cubic meter or denser density by absolute weight base and 200 kilogram per square meter or compressive strength at 20 day, etc are required so as to obtain acid-resistant mortar. In addition to the above, it might be recommonded to select the fine aggregate and to use better equipments such as a mechanical vibrator, a mechanical mixer etc. in concrete manufacturing works.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.3 no.2
• /
• pp.191-198
• /
• 1999

The purpose of this study is investigating characteristics of the concrete containing Fly-ash according to different 4 mix design, that is, the first mix design is partial replace Fly-ash of cement, second is partial replace Fly-ash of cement and fine aggregate, third is partial replace Fly-ash of fine aggregate, fourth partial replacement of fine and coarse aggregate. For this purpose, selected test variables were water-binder ratio with two levels of 45%, 50%, and Fly-ash contents with four levels 0%, 10%, 20%, 30%, As the result of this study are as follow. 1) The result of mix design of a partial replacement of cement, the slump-flow value was appeared a promotive effect of viscosity. But in case of the over with Fly-ash 10% and the other mix design was not changed slump value. 2) The unit weight of the mixing rate with Fly-ash 0% was $1.875{\sim}1.884t/m^3$, the other mix design 10% over with Fly-ash was $1.846{\sim}1.615t/m^3$, the difference was appeared less about 15% than that. 3) In design, partial replace Fly-ash of fine aggregate, this compressive strength was appeared that the concrete age after 7 days was higher than in partial replacement of cement, therefore, the default of a concrete with Fly-ash, that is the earlier compressive strength was to lessen, was improved. 4) The thermal conductivity of the all mix design was $0.447{\sim}1.144kcal/mh^{\circ}C$, this value was as good as a lightweight aggregate concrete.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.1
• /
• pp.76-84
• /
• 2013

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at $4^{\circ}C$ and $10^{\circ}C$. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at $4^{\circ}C$. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at $4^{\circ}C$ and $10^{\circ}C$. Lc. gelidum was detected as the dominant LAB at $4^{\circ}C$ in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At $4^{\circ}C$, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.

• Geotechnical Engineering
• /
• v.12 no.3
• /
• pp.17-34
• /
• 1996

The objective of this paper is to evaluate the asphalt mixture performance with pyrolyzed carbon black(CBP) and air -cooled iron blast furnace slag. Marshall mix design was performed to determine the optimum binder content, The optimum binder content ranged from 6.3 percent to 7.75 percent. Dynamic creep testing was carried out using mixtures at the optimum binder content. Based on the test results, the use of pyrolyzed carbon black and slag in the asphalt pavement showed a positive result, such as the increase of Marshall stability, the decrease of the strain rate and the decrease in the mix stiffness rate at high temperature(5$0^{\circ}C$) and 137.9 kPa confinement. Within the limits of this research. it was concluded that pyrolyzed carbon black as an additive and slag as a coarse aggregate could be used to produce an asphalt paving mixture that has good stability, stiffness, and rutting resistance.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.823-830
• /
• 1999

The suppressing effects of crude extracts of three Korean teas, persimmon leaf tea extract (PLTE), green tea extract (GTE) and oolong tea extract (OTE), were studied on the induction of sister chromatid exchange (SCE) in cultured Chinese hamster ovary cells. When cells were treated with tea extract after mitomycin C (MMC) treatment, the frequency of MMC-induced SCEs were decreased at the high concentration $(1000\;{\mu}g/mL)$ of PLTE in the presence of S9 mix and at low concentrations $(20{\sim}80\;{\mu}g/mL)$ of PLTE in the absence of S9 mix, Whereas GTE and OTE showed suppressing effects on the MMC-induced SCEs at low concentrations $(10{\sim}20\;{\mu}g/mL)$ for OTE and $160\;{\mu}g/mL$ for GTE only in the presence of S9 mix. MMC-induced SCEs were decreased by post-treatment with each tea extracts with S9 mix in the G1 phase of the cell cycle. These results suggest that PLTE, GTE and OTE could have bio antimutagenic activities, and also suggest that PLTE might have unknown antimutagenic components which would be responsible for the inhibitory effect against direct acting mutagenicity.

• Korean Journal of Poultry Science
• /
• v.35 no.1
• /
• pp.29-37
• /
• 2008

This study was evaluated the oxidative stability of the breast and leg meat from chicken fed extract of medicinal herb mix (Lonicera japonica Thunberg : Morus alba L. : Coptis chinensis = 48.5 : 48.5 : 3.0%) and antibiotics (Albac G150). Ross chickens were divided into three treatments: basal diet (control), basal diet with antibiotics (0.05%) and basal diet with extract of medicinal herb mix (0.3%). They were fed the experimental diets for 35 days and slaughtered. After that, the breast and leg meat samples were stored at $4^{\circ}C$ for 10 days. Total phenol content of breast meat in Ross chicken fed extract of medicinal herb mix was higher than that of antibiotics treatment and control during storage. DPPH radical scavenging activity was the highest in leg meat of Ross chicken fed extract of medicinal herb mix at 0 day. $ABTS^+$ reduction activity was higher in chicken meat fed extract of medicinal herb mix than antibiotics treatment and control. This results showed that the diet with extract of mixed medicinal herb was more effective in oxidative stability of chicken meat than basal diet and diet with antibiotics.