• The Korean Journal of Pesticide Science
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• v.6 no.3
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• pp.175-182
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• 2002

This experiment was conducted to investigate the effects of acid rain in spraying copper hydroxide 77% wettable power(WP) on leaf surface morphology and crop injury of the garlic(Allium sativum L.). Leaf chlorosis, hooked leaves, wrinkled epidermal cells and increased stomata open of garlic were induced by foliar application of simulated acid rain(SAR). It was become to be severe in application of copper hydroxide solution after application of SAR, but those yield of garlic was not significantly different from the untreated control. Leaf chlorosis was sharply increased above 100 ppm of copper ions. Amount of solved copper ions in copper hydroxide solution was remarkably increased below pH 5.5 and the residue in garlic leaves was significantly increased by application of copper hydroxide solution after spraying SAR compared with application of copper hydroxide solution only. When calcium carbonate was applied together with copper hydroxide leaf chlorosis was less than copper hydroxide only.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.58-65
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• 2021

In this study, as a method to increase the recycling of circulating fluidized bed combustion ash(CFBCA), CFBCA was utilized to produce autoclave aerated concrete product since CFBCA contains quicklime and calcium sulfate components that are required for the manufacture of autoclave aerated concrete. Successful achievement of such objective will bring cost reduction with high value addition, saving of natural resources, and the reduction of environmental load. Various mixing designs were designed to evaluate the properties of autoclave aerated concrete made of CFBCA. Based on series of experimental program, prototypes mix design for factory manufacturing was obtained. According to the experimental results, it was confirmed that gypsum can be replaced with CFBCA through the method of pre-treating the CFBCA as a slurry. It was possible to produce competitive autoclave aerated concrete products using CFBCA.

• New & Renewable Energy
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• v.19 no.1
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• pp.1-11
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• 2023

A large amount of carbon monoxide (CO) is generated in circulating fluidized bed combustion, the process whereby a hot cyclone separates unburned fuel. However, calcium sulfate (CaSO₄), when combined with a high CO content, can cause fouling on the surface of the steam tube installed inside the integrated recycle heat exchangers (INTREX). In this study, CaSO₄ decomposition was investigated using 0.2-3.2 vol.% CO and 1-3 vol.% oxygen (O₂) at 850℃ for 20 min in a lab-scale fluidized bed reactor. The results show that CaSO₄ decomposes into CaS and CaO when CO gas is supplied, and SO₂ emissions increase from 135 ppm to 1021 ppm with increasing CO concentration. However, the O₂ supply delayed SO₂ emissions because the reaction between CO and O₂ is faster than that of CaSO₄; nevertheless, when supplied with CaCO₃, the intermediate product, SO₂ was significantly released, regardless of the CO and O₂ supply. In addition, agglomerated solids and yellow sulfur power were observed after solid recovery, and the reactor distributor was corroded. Consequently, a sufficient O₂ supply is important and can prevent fouling formation on the INTREX surface by suppressing CaSO₄ degradation.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.716-723
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• 1995

The fucoidan purified from Korean brown seaweed, Ecklonia stolonifera was characterized on molecular structure and blood anticoagulant activities. Extraction was conducted at $100^{\circ}C$ with water and repeated twice. The crude fucodian was 151.1g out of 20.0 kg of Ecklonia stolonifera. The Fucoidan-1, which was purified from crude fucoidan using calcium chloride and cetyl pyridium chloride (CPC), was 35.2% against crude fucoidan. Fucoidan-5 was obtained approximately 28.1% from Fucoidan-1 through DEAE-Toyopearl 650 M ion-exchange column chromatography and showed one band by cellulose acetate electrophoresis. The molecular weight of Fucoidan-5 was estimated to be about 21,000∼23,000 dalton by Sephacryl S-300 gel filtration chromatography. Fucoidan-5 consists of 35.7% of fucose and 4.3% of galactose and the molar ratio of fucose and sulfate was about one to one. IR spectrum of Fucoidan-5 showed absorption at $1240\;cm^{-1}\;and\;850\;cm^{-1}$ and specific rotation value, $[\alpha]$, was $[\alpha]$. These results suggests that the sulfate maybe bind at $C_{4}$ carbon on ${\alpha}-L-fucose$. Gas chromatograph of methyl alditol acetate revealed that Fucoidan-5 is a fucose containing sulfated polysaccharide with $({\alpha}l-2)\;or\;({\alpha}l-2)$ glycosidic linkage. Anti-thrombin activity of the Fucoidan-5 was estimated as 1.4 time stronger than heparin. From above results, the purification methods using CPC and ion exchange chromatography is effective tools for obtaining highly purified fucoidan from Gompi, Ecklonia stolonifera.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.257-274
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• 2018

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, $H_2SO_4$ and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven ($37^{\circ}C$). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of $H_2SO_4$ and temperature of acid-solution. Acid-treatment conditions (concentration of $H_2SO_4$, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with $90^{\circ}C$ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.47-58
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• 1981

Relationships between the electrical conductivity and the contents of the chloride, sulfate, calcium, magnesium, sodium, potassium and total major inorganic ions, and between each, chemical conservative constituents were calculated with the data which sampled at the lesions of Mulgeum and between Namji and Wondong from March 1974 to April 1980. Semilogarithmic relations were found between the electrical conductivity and the contents of monovalent ions, and logarithmic relations were found between the electrical conductivity and the contents of divalent ions at the both regions. The relational equations between the electrical conductivity $\lambda_{25}$and the contents of the major inorganic ions at Mulgeum are as follows: $log\;Cl(ppm)\;=\;2.37{\cdot}\lambda_{25}(m{\mho}/cm)+0.733{\pm}0.141$, $log\;SO_4(ppm)=1.12{\cdot}log\lambda_{25}(m{\mho}/cm)+2.14{\pm}0.18$, $log\;Ca(ppm)=0.615{\cdot}log\lambda_{25}(m{\mho}/cm)+1.67{\pm}0.12$, $log\;Mg(ppm)=0.756{\cdot}log\lambda_{25}(m{\mho}/cm)+1.27{\pm}0.11$, $log\;Na(ppm)=2.82{\cdot}\lambda_{25}(m{\mho}/cm)+0.551{\pm}0.133$, $log\;K(ppm)=1.33{\cdot}\lambda_{25}(m{\mho}/cm)+0.136{\pm}0.095$, and total inorganic ions $C(ppm)=399{\cdot}\lambda_{25}(m{\mho}/cm)-0.9{\pm}14.6$. The relational equations between the electrical conductivity ($\lambda_{25}$) and the contents of the major inorganic ions at the region between Namji and Wondong a.e as follows: $log\;Cl(ppm)=4.27{\cdot}\lambda_{25}(m{\mho}/cm)+0.380{\pm}0.138$, $log\;SO_4(ppm)=0.915{\cdot}log\lambda_{25}(m{\mho}/cm)+1.95{\pm}0.18$, $log\;Ca(ppm)=0.756{\cdot}log\lambda_{25}(m{\mho}/cm)+1.74{\pm}0.12$, $log\;Mg(ppm)=1.00{\cdot}log\lambda_{25}(m{\mho}/cm)+1.41{\pm}0.10$. $log\;Na(ppm)=2.47{\cdot}\lambda_{25}(m{\mho}/cm)+0.614{\pm}0.065$, $log\;K(ppm)=1.62{\cdot}\lambda_{25}(m{\mho}/cm)+0.030{\pm}0.060$, and total inorganic ions $C(ppm)=323{\cdot}\lambda_{25}(m{\mho}/cm)+11.7{\pm}9.3$. Logarithmic relations were found between each chemical conservative constituents at Mulgeum and the equations are as follows: $log\;Cl(ppm)=0.711{\cdot}log\;SO_4(ppm)+0.488{\pm}0.206$, $log\;Cl(ppm)=0.337{\cdot}log\;Ca(ppm)+0.822{\pm}0.130$, $log\;Cl(ppm)=0.605{\cdot}log\;Mg(ppm)-0.017{\pm}0.154$, $Cl(ppm)=0.676{\cdot}Na(ppm)+2.31{\pm}4.67$, $log\;Cl(ppm)=0.406{\cdot}log\;K(ppm)-0.092{\pm}0.112$, $log\;SO_4(ppm)=0.378{\cdot}log\;Ca(ppm)+0.721{\pm}0.125$, $log\;SO_4(ppm)=0.462{\cdot}log\;Mg(ppm)+0.107{\pm}0.118$, $log\;SO_4(ppm)=0.592{\cdot}log\;Na(ppm)+0.313{\pm}0.191$, $log\;SO_4(ppm)=0.308{\cdot}log\;K(ppm)-0.019{\pm}0.120$, $Ca(ppm)=0.262{\cdot}Mg(ppm)+0.74{\pm}1.71$. $log\;Ca(ppm)=1.10{\cdot}log\;Na(ppm)-0.243{\pm}0.239$, $Ca(ppm)=0.0737{\cdot}K(ppm)+1.26{\pm}0.73$, $log\;Mg(ppm)=0.0950{\cdot}Na(ppm)+0.587{\pm}0.159$, $log\;Mg(ppm)=0.0518{\cdot}K(ppm)+0.111{\pm}0.102$, and $Na(ppm)=0.0771{\cdot}K(ppm)+1.49{\pm}0.59$. Logarithmic relations were found between each chemical conservative constituents except a relationship between the chloride and calcium contents at the region between Namji and Wondong, and the equations are as follows : $log\;Cl(ppm)=0.312{\cdot}log\;SO_4(ppm)+0.907{\pm}0.210$, $log\;Cl(ppm)=0.458{\cdot}log\;Mg(ppm)+0.135{\pm}0.130$, $Cl(ppm)=0.484{\cdot}logNa(ppm)+0.507{\pm}0.081$, $Cl(ppm)=0.0476{\cdot}K(ppm)+1.41{\pm}0.34$, $log\;SO_4(ppm)=0.886{\cdot}log\;Ca(ppm)+0.046{\pm}0.050$, $log\;SO_4(ppm)=0.422{\cdot}log\;Mg(ppm)+0.139{\pm}0.161$, $log\;SO_4(ppm)=0.374{\cdot}log\;Na(ppm)+0.603{\pm}0.140$, $log\;SO_4(ppm)=0.245{\cdot}log\;K(ppm)+0.023{\pm}0.102$, $log\;Ca(ppm)=0.587{\cdot}log\;Mg(ppm)+0.003{\pm}0.088$, $log\;Ca(ppm)=0.892{\cdot}log\;Na(ppm)+0.028{\pm}0.109$, $log\;Ca(ppm)=0.294{\cdot}log\;K(ppm)-0.001{\pm}0.085$, $log\;Mg(ppm)=0.600{\cdot}log\;Na(ppm)+0.674{\pm}0.120$, $log\;Mg(ppm)=0.440{\cdot}log\;K(ppm)+0.038{\pm}0.081$, and $log\;Na(ppm)=0.522{\cdot}log\;K(ppm)-0.260{\pm}0.072$.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.8
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• pp.554-560
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• 2014

To investigate the applicability of montmorillonite to capping material for the remediation of contaminated marine sediment, adsorption characteristics of $PO{_4}{^{3-}}$ onto montmorillonite were studied in a batch system with respect to changes in contact time, initial concentration, pH, adsorbent dose amount, competing anions, adsorbent mixture, and seawater. Sorption equilibrium reached in 1 h at 50 mg/L but 3 h was required to reach sorption equilibrium at 300 mg/L. Freundlich model was more suitable to describe equilibrium sorption data than Langmuir model. The $PO{_4}{^{3-}}$ adsorption decreased as pH increased, due to the $PO{_4}{^{3-}}$ competition for favorable adsorption site with OH- at higher pH. The presence of anions such as nitrate, sulfate, and bicarbonate had no significant effect on the $PO{_4}{^{3-}}$ adsorption onto the montmorillonite. The use of the montmorillonite alone was more effective for the removal of the $PO{_4}{^{3-}}$ than mixing the montmorillonite with red mud and steel slag. The $PO{_4}{^{3-}}$ adsorption capacity of the montmorillonite was higher in seawater than deionized water, resulting from the presence of calcium ion in seawater. The water tank elution experiments showed that montmorillonite capping blocked well the elution of $PO{_4}{^{3-}}$, which was not measured up to 14 days. It was concluded that the montmirillonite has a potential capping material for the removal of the $PO{_4}{^{3-}}$ from the aqueous solutions.

• Journal of Mushroom
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• v.7 no.1
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• pp.9-21
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• 2009

This study was executed in an attempt to investigate a artificial requisites of fruitbody occurrence. Environmental requirements on habitat for fruitbody occurrence of collected cultures resulted in leading to $13-16^{\circ}C$ and 75% relative humidity, and requiring silt loam of soil texture which had more nutritional substances than a dry field. Optimal temperature was $25^{\circ}C$, medium PDB, and pH 5.0 in cultural conditions. Mannose required of 5% in ASI 59002, 59003, 59004, but 3% in ASI 59001 was selected as optimum carbon source. The substrates stimulating sclerotium formation were cotton waste, or cotton waste + oak sawdust (mixture ratio of 8:2), which had 20% additive of wheat barn respectively. Sclerotium was formed well in the substrate adjusted chemical properties by applying 2% of calcium sulfate. Sclerotium formation was the most effective in the treatment of peat moss + oak sawdust (mixture ratio of 5:5) + 30% of wheat barn.

• Journal of the Korea Concrete Institute
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• v.16 no.6 s.84
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• pp.777-783
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• 2004

In this study, for improving of concrete properties, those are used ground granulated blast slag(GGBS) and fly ash(FA). There are some advantage to add the GGBS and FA in plain concrete. The objective of this study is to find the characteristics of fresh and hardened antiwashout underwater concrete which is followed by blended ratio of GGBS and FA. Experimental parameters were chosen that W/C was 50%, S/a was 40% and as the blended ratio of GGBS was set at 0, 10, 20, 30, 40, 50, 60% and FA was set at 0, 10, 15, 20, 25, 30, 35% in order to prove the properties of antiwashout underwater concrete can be changed by blended ratio of GGBS md FA. It was measured pH, suspension and slump flow of fresh antiwashout underwater concrete and compressive strength of hardened antiwashout underwater concrete in age of 7 days, 28 days and 56 days. The experimental results of fresh concrete show that pH, suspension and slump flow were all satisfied with KSCE (Korea Society of Civil Engineering) standard value and mix design standard value. To synthetically consider, the optimum blended ratio is about 30% of GGBS and FA.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.557-563
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• 2008

Recently, the amount of disposed construction materials like demolished concrete is growing fast and the shortage of natural concrete aggregate is becoming serious. Therefore, recycling of aggregate extracted from the demolished concrete is getting important and use of the recycled aggregate for concrete has been seriously considered. However, the use of the recycled aggregate even for low performance concrete is very limited because recycled aggregate which contains large amount of old mortar has very low quality. Therefore, removing the paste sticked to the recycled aggregate is very important in the manufacturing of high quality recycled aggregate. We have studied a series of research according to complex crushing method, which is removed the ingredient of cement paste from recycled fine aggregate using both the low speed wet abrasion crusher as mechanical process and the acid treatment as chemical processes. This paper is to analyze the quality of the recycled fine aggregate produced by those complex method and investigate optimum manufacturing condition for recycled fine aggregate by the design of experiments. The experimental parameters considered are water ratio, coase aggregate ratio, and abrasion time. As a result, data concerning the properties of recycled sand were obtained. It was found that high quality recycled fine aggregate could be to obtain at the condition of the fifteen minute of abrasion-crusher time and the over 1.0 of recycled coarse aggregate ratio.