• Journal of the Korean Society of Groundwater Environment
• /
• v.6 no.4
• /
• pp.194-205
• /
• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.4
• /
• pp.352-362
• /
• 1985

In succession to the previous paper, the present study was directed to investigate the optimal processing conditions of meat paste products with mackerel. To improve the gel forming ability of meat paste, washing conditions with water and alkaline solution, setting time and temperature, and heating temperature were controlled, and the influences of the freshness of raw mackerel and mixing ratios of ordinary and dark muscle on the qualities of meat paste products were discussed. The most effective condition for the keeping freshness of raw mackerel meat among different storage conditions was the forozen storage at $-20^{\circ}C$, followed by the storage at $-3^{\circ}C$ and ice storages, and this relation was coincided with the effect for maintaining of gel forming ability among above conditions, but there was no effect on keeping freshness of raw mackerel in the storage at $25^{\circ}C$. Gel strength of meat washed with tap water decreased with washing time, particularly, the meat washed three times showed higher gel strength than the meat washed more than 5 times. And the removal ratios of water soluble protein were $60\%$ in the meat washed three times and $90\%$ in the meat washed nine times. Washing effect of raw mackerel meat with alkaline solution was great at pH $6.5{\sim}7.0$ of meat paste yielding the highest gel strength in the meat washed with $0.5\%$ sodium bicarbonate solution. Gel strength of meat paste product decreased with the increase of mixing ratios of ordinary and dark muscle in the raw meat. In the setting conditions of meat paste examined, 15 hours at $5^{\circ}C$ and 2 hours at $30^{\circ}C$. The most suitable temperature for gel forming in heating conditions was $90^{\circ}C$, fellowed by $100^{\circ}C\;and\;80^{\circ}C$.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.3
• /
• pp.36-44
• /
• 2007

The purpose of this study was to investigate thermal stability, reactivity, and bonding strength of existing epoxy resin mixed with the epoxidized soybean oil (ESBO) in order to use soybean oil economically. In the dry shear test, the marked strengths showed $30.5kgf/cm^2$ at the ratio of ESBO to epoxy resin 9 : 1 and $6.2kgf/cm^2$ at the ratio 8 : 2. The bonding strengths of the others, except mixing ratios 2 : 8 and 1 : 9, exceeded the requirement of Korean plywood standard of $7.0kgf/cm^2$. In the wet shear test, the result was $5.8kgf/cm^2$ at the ratio 9 : 1. There were no thickness swelling and moisture absorption in the water resistance of the film. The value of activation energy, Tg (${\Delta}E$), by DSC analysis showed between $110^{\circ}C$ and $120^{\circ}C$ through all ratios. Epoxy in the epoxy resin fully reacted with the hardener (TETA), but it is difficult to decide that epoxys in the ESBO were reacted directly with the hardener from FT-IR analysis. As the mixing ratio of ESBO increased, the thermal stabilities dropped from TGA analysis. From the comprehensive view on the results of above experiments, it could be confirmed through experiments that the ESBO in the mixed adhesive of epoxy resin/ESBO played a role as an extending agent level of epoxy adhesive, and we were able to know that in order to utilize ESBO as an adhesive, a study should be performed on the condition of hardening, inducible of the hardening reaction.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.2
• /
• pp.62-69
• /
• 2003

The aim of research is the evaluation of the $Cr^{6+}$ emission features of the liquid injection through emission experiments in varying conditions, based on a field-mixing ratio. The results showed that the content of $Cr^{6+}$ content in cement measured had an Ordinary Potland Cement (OPC) of 25.3 mg/kg, which constitute the largest portion among the other materials. Likewise, the emission experiment of homo-gel and sand-gel generally satisfied the standard of KSLT (Korea Standard Leaching Test) in waste of 1.5 mg/L, but in case of the standard of KSLT in soil the emission of OPC $Cr^{6+}$ of 4.85 mg/kg. These conditions is a little exceeded the criteria in the ‘Ga’ area in terms of Korea Soil Environmental Preservation Law. In addition, results generated by the mock-up injection facilities revealed that $Cr^{6+}$ emission increased as Water/Cement and injection pressure increased. At injection pressure higher than 4 kg/㎤, $Cr^{6+}$ emission exceeded the water preservation standard of 0.5 mg/L. Similarly, a pattern experiment of C $r^{6+}$ emission according to pH was conducted, in order to evaluate the $Cr^{6+}$ emission features of grout materials in leachate below pH 5 such as pH 4 acid rain or landfill. Results show that $Cr^{6+}$ emission dramatically increased in high acidic or basic state. It indicates that $Cr^{6+}$ emission will probably increase in an environment where grout materials are injected. On the other hand, concentration of leachate was determined in areas where grout materials are used. The results show that the concentration of emission in an ultra purity condition does not manifest intensity, and is affected in the OPC>MC>SC order. It means that the pollutants or $Cr^{6+}$ emission increases with decreasing concentration. As such, $Cr^{6+}$ emission will probably exceed the countermeasure criteria according to the types of gout materials. Similarly, high pressure or injection will cause increased $Cr^{6+}$ emission. Therefore, the selection of materials or mixing ratio should be considered in general as well as according to specific industries, based on the strength and pH of $Cr^{6+}$ emission.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.6
• /
• pp.419-427
• /
• 2005

For the purpose to verify the physico­chemical properties of Korean waxy wheat, comparative analyses between waxy wheat lines and their respective maternal parents were performed on mixing and pasting properties, and flour particle sizes. The particle sizes of waxy wheat flour were significantly larger than those of their parents when milled in a same condition. Although the protein contents of flour in waxy wheat lines tested were high as much as those of bread wheat, the quality parameters showed lower baking uses based on sedimentation volumes and mixing characteristics. Waxy flour required more water than non-waxy flour to obtain the proper mixogram. Waxy wheat flour showed more or less higher onset pasting temperatures and much higher breakdown viscosities than their respective parent flour in the Rapid Viscograph test. Moreover, peak viscosity temperatures and final viscosities were dramatically reduced in waxy wheat lines by showing $79.4 - 81.7^{\circ}C$ and 101 ­116.9 RVU, respectively, compared to their parents in that the temperatures above $95^{\circ}C$ and the viscosity ranges of 148 -171.8 RVU.

• The Korean Journal of Mycology
• /
• v.34 no.2
• /
• pp.73-78
• /
• 2006

Attempts were made to investigate the physiological and genetic changes when two different shiitake (Lentinula edodes) strains are mixed. Mycelial growth of KFRI 180 strain and KFRI 1 strain were investigated 82 mm and 80 mm, respectively. Concerning the weight loss percentage of medium, KFRI 1 strain decreased 2.4% and KFRI 180 strain 1.6%. Plug-shaped spawn had no-problem to incubate and there were no differences among the ratios of mixture. Also, conditions of plug-shaped spawns were similar, When the isolated mycelia from plugshaped spawns was incubated again, KFRI 1 50%-KFRI 180 50% showed decreased growth of mycelia compared with other treatments. The same results were obtained from test tubes filled with sawdust. When surface of spawn bottles were observed, KFRI 1 50%-KFRI 180 50% showed spots, but other treatments were not different from KFRI 1 and KFRI 180. Test was made to confirm the strains by confrontation culture. The mixture of two strains was proved to be KFRI 1 regardless the ratios of mixture. However, by the RAPD primer analysis, when KFRI 1 was mixed with KFRI 180, KFRI 180 was stronger. Thus, the confrontation line on PDA was different from the bands analysis by primers. Attempts were made whether the fruit-bodies were made at the generating condition of spawn bottles. The results were that KFRI 1 100%, KFRI 1 90%-KFRI 180 10%, KFRI 1 80%-KFRI 180 20%, KFRI 1 50%-KFRI 180 50% treatment showed fruit-body formation. The shape of fruit-body was deformed, but the gill was made normally.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.12
• /
• pp.19-30
• /
• 2010

Bentonite-based grout has been widely used to seal a borehole constructed for a closed-loop vertical ground heat exchanger in a geothermal heat pump system (GHP) because of its high swelling potential and low hydraulic conductivity. Three types of bentonites were compared one another in terms of viscosity and thermal conductivity in this paper. The viscosity and thermal conductivity of the grouts with bentonite contents of 5%, 10%, 15%, 20% and 25% by weight were examined to take into account a variable water content of bentonite grout depending on field conditions. To evaluate the effect of salinity (i.e., concentration of NaCl : 0.1M, 0.25M, and 0.5M) on swelling potential of the bentonite-based grouts, a series of volume reduction tests were performed. In addition, if the viscosity of bentonite-water mixture is relatively low, particle segregation can occur. To examine the segregation phenomenon, the degree of segregation has been evaluated for the bentonite grouts especially in case of relatively low viscosity. From the experimental results, it is found that (1) the viscosity of the bentonite mixture increased with time and/or with increasing the mixing ratio. However, the thermal conductivity of the bentonite mixture did not increase with time but increased with increasing the mixing ratio; (2) If bentonite grout has a relatively high swelling index, the volume reduction ratio in the saline condition will be low; (3) The additive, such as a silica sand, can settle down on the bottom of the borehole if the bentonite has a very low viscosity. Consequently, the thermal conductivity of the upper portion of the ground heat exchanger will be much smaller than that of the lower portion.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.2
• /
• pp.148-169
• /
• 2023

Hayeob pigment is known as one of the traditional dark green pigments, but the color, raw material, and manufacturing method have not been clearly identified. However, comparing the analysis results of the particle shape and constituent minerals of Hayeob pigments revealed through pigment analysis studies of colored cultural properties such as Dancheong, Gwaebul, and paintings, Hayeob pigments appear to be the same as Dongrok pigments produced by salt corrosion. Therefore, in order to restore Hayeob pigment, the manufacturing method of Dongrok pigment was studied based on the records of old literature. The Dongrok pigment manufacturing method confirmed in the old literature records is a natural corrosion method in which copper powder and a caustic are mixed and then left in a humid condition to corrode. Based on this, artificial corrosion using a corrosion tester was adopted to corrode the copper powder more efficiently, and an appropriate mixing ratio was selected by analyzing the state of corrosion products according to the mixing ratio of the caustic agent. In addition, the manufacturing method of Dongrok pigment was established by adding a salt removal process to remove residual caustic agents and a purification process to increase chroma during pigment coloring. The prepared Dongrok pigments have a bluish green or green color, show an elliptical particle shape and a form in which small particles are aggregated, and a porous surface is observed. The main constituent elements are copper(Cu) and chlorine(Cl), and the main constituent mineral is identified as atacamite [Cu₂Cl(OH)₃]. As a result of an accelerated weathering test to evaluate the stability of the prepared Dongrok pigments, it was found that the greenness partially decreased and the yellowness significantly increased as deterioration progressed. Before deterioration, the Dongrok pigments had lower yellowness compared to the Hayeob pigments of the old Dancheong, but after deterioration, yellowness increased significantly, and it was found to have a similar chromaticity range as Dancheong's Hayeob pigments. As a result, the prepared Dongrok pigments were confirmed to be similar to Dancheong's Hayeob pigments in terms of color as well as particle shape and constituent minerals.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.1
• /
• pp.83-88
• /
• 2014

This research was carried out to determine the characteristics of germination in relation to temperature, and seedling emergence and growth affected by soil moisture in forage millet. The seeds of forage millet could germinate at more than $15^{\circ}C$ at the rate of 0, 90.5, 97.3 and 96.8% respectively 10 days after seeding at 10, 15, 20 and $25^{\circ}C$. The result showed that the temperature needs to be $15^{\circ}C$ or more for the seeds to germinate. The effects of seeding depth on the growth characteristics and emergence of millet seed were investigated in waters and direct seeding methods by thoroughly mixing the seed and soil. In water treatment, the emergence rates were 3.7% at $15^{\circ}C$, 7.6% at $20^{\circ}C$, 6.3% at $25^{\circ}C$, while direct seeding treatment showed the emergence rates of 65.6, 75 and 71% at 15, 20 and $25^{\circ}C$, respectively. At 15, 20, and $25^{\circ}C$, seeds in water seeding could germinate at 0.5, 1.8, 1.5 cm of soil depth, while in direct seeding, they could germinate at the depth of 9.5, 10.0, 9.9 cm. When the initial growth characteristics of the seeds were investigated, there was positive correlation between seeding depth and mesocotyl length in both water and direct seed methods. Growth and development in terms of leaf age, root length, coleoptiles and mesocotyl length, and plant height were found maximum at 0.5 cm soil depth for water seeding, and 3-5 cm soil depth for direct seeding. Results showed that there were close relationship among temperature, soil depth and moisture acquiring methods, and the combination of these factors greatly affected the initial growth characteristics and development of millet seeds. It can be concluded that, to get good seedling stand and germination of millet seed, millet should grown in field condition at the depth of 0.5 cm or less for water seeding, and 3-5 cm for direct seeding method.

• Journal of the Society of Disaster Information
• /
• v.8 no.1
• /
• pp.18-26
• /
• 2012

Accordingly architectural structure is getting high-rise and bigger, a use of high strength and high performance concrete has been increasing. High performance concrete has cons of explosion in a fire. This Explosion in the fire can cause the loss of the sheath on a concrete surface, therefore it effects that increasing a rate of heat transmission between the steel bar and inner concrete. Preventing this explosion of high performance concrete in the fire, many kinds of researches are now in progressing. Typically, researches with using Polypropylene-fiber and Steel-fiber can prove controling the explosion, but the reduction of mobility was posed as a problem of workability. Consequently, to solve the problem as mentioned above, concrete cans secure fire resisting capacity through the using of coating liquid, including Ester-lubricant and non-ionic characteristic surfactant. This research has been drawn a ideal condition in compressive strength areas of concrete by an experiment. When applying 13mm of polyamide-fiber, proper fiber mixing volume by compressive strength areas of concrete is $0.8kg/m^3$ in 60MPa, $1.0kg/m^3$ in 80MPa, $1.5kg/m^3$ in $100MPa/m^3$. These amount of a compound can control the explosion.