• Korean Journal of Materials Research
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• v.21 no.9
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• pp.502-508
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• 2011

The goal of the present work was to investigate the development of a geopolymeric ceramic material from a mixture of mine residue, coal fly ash, blast furnace slag, and alkali activator solution by the geopolymer technique. The results showed that the higher compressive strength of geopolymeric ceramic material increased with an increase in active filler (blast furnace slag + coal fly ash) contents and with a reduction of mine residue contents. The geopolymeric ceramic had very high early age strength. The compressive strength of the geopolymeric ceramic depended on the added active filler content. The maximum compressive strength of the geopolymeric ceramic containing 20 wt.% mine residue was 141.2 MPa. The compressive strength of geopolymeric ceramic manufactured by adding mine residue was higher than that of portland cement mortar, which is 60 MPa, when cured for 28 days. SEM observation showed the possibility of having amorphous aluminosilicate gel within geopolymeric ceramic. XRD patterns indicate that the geopolymeric ceramic was composed of amorphous aluminosilicate, calcite, quartz, and muscovite. The Korea Standard Leaching Test (KSLT) was used to determine the leaching potential of the geopolymeric ceramic. The amounts of heavy metals were noticeably reduced after the solidification of mine residue with active filler.

• YAKHAK HOEJI
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• v.50 no.3
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• pp.172-176
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• 2006

The purpose of this study is to develop a mass preparation method of (+)-decursinol from Angelica gigas roots. Recently; it has been shown that (+)-decursin, (+)-decursinol angelate and its analogues, isolated from Angelica gigas roots, exhibit various biological activities such as antitumor, antibacterial and neuroprotective activities. The contents of these compounds, ester form of (+)-decursinol, is very high in the Angelica gigas roots, whereas the content of (+)-decursinol itself is very low Therefore, (+)-decursinol which can be used as starting material to synthesize various its analogues was easily prepared from decursin analogues in the Angelica gigas roots. In order to achieve such aim, the Ether-Fr. of the ethanol exact of Angelica gigas roots was hydrolysed with various alkalis and solvents. As a result, the order of (+)-decursinol preparation was 1) NaOH, KOH, 2) $K_2CO_3$, and 3) $NaHCO_3$ as alkali. Also, the yield of (+)-decursinol was higher in diethyl ether than any other solvent conditions. From 1 kg of dried Angelica gigas roots, we could obtain 27.4 g of (+)-decursinol as a pure white solid.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Resources Recycling
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• v.9 no.1
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• pp.63-69
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• 2000

Ferromanganese dust is an oxide substance of Mn. If imprities are removed and oxidation degree is controlled, the dust can be recycled for soft ferrite materials. The ferromanganese dust contained about 7 kinds of impurities, expecially about 9000 ppm of $SiO_2$ contents of the ferromanganese dust from 9000 ppm to under 500 ppm by fritting method. The $SiO_2$ in ferromanganese dust can be converted into water soluble compounds by alkali fritting and removed by water leaching. KOH and NaOH were used. The most effective conditions to get rid of $SiO_2$ from the dust are that the weight ratio of alkali to ferromanganese dust is 1.75 and fritting is run at $550^{\circ}C$ for 1 hour.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.67-74
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• 2010

This study was carried out to investigate the pulping and papermaking characteristics of lotus (Nelumbo nucifera G.) leafstalk for the development of high performance paper. Anatomical and chemical properties of the lotus leafstalk were analyzed. The pulping and papermaking properties of the lotus leafstalk by conventional alkali and sulfomethylated pulping processes were also evaluated. The length and width of fibers were 0.06-3.32 mm (av. 1.23 mm) and 3.47-25.6 ${\mu}m$ (av. 20.7 ${\mu}m$), respectively. The length and width of vessel elements were 0.07-0.78 mm (av. 0.20 mm) and 14.1-330.0 ${\mu}m$ (av. 54.13 ${\mu}m$), respectively. The fiber length/fiber width ratio was 60.20. The extractives (cold water, hot water, 1% NaOH and ethanol-benzene) and lignin content of lotus leafstalk were higher than those of plant bast fiber. The contents of holocellulose, lignin, and ash were 73.8%, 24.3%, and 4.3%, respectively. The pulp yields based on pulping methods were sulfomethylated pulping av. 52%, and alkaline pulping av. 42%. The conventional alkaline pulping shows better pulp and sheet properties than the sulfomethylated pulping which was modified pulping processes. But the sulfomethylated pulping shows higher brightness than alkali pulping. In the consequence of FE-SEM observation, lotus leafstalk pulp consists of various kinds of thin walled fibers which have large amount of small pits.

• Journal of the Korea Concrete Institute
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• v.28 no.1
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• pp.49-57
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• 2016

The aim of this study was to investigate the fundamental properties of pyroclastic flow deposit (PFD), and evaluate the fresh and strength properties of concrete mixed with PFD by indoor tests. The fresh properties, strength properties, shrinkage properties, and durability of the concrete mixed with PFD were also evaluated by outdoor plant tests. the harmful alkali-silica reaction did not occur by mixing concrete with PFD. ages. Moreover, no difficulty was found to be associated with concrete manufacture in the plant because no change in air contents and noticeable slump loss occurred by mixing concrete with PFD. The strength properties, shrinkage properties, and durability of the concrete mixed with PFD were also compared with those of normal concrete. With a suitable temperature control and curing method of concrete, the concrete mixed with PFD is considered to be useful in the construction material field.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.369-379
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• 1995

About forty ore deposits of $CaF_2{\pm}Au{\pm}Ag{\pm}Cu{\pm}Pb{\pm}Zn$ are widely distributed in the Geumsan district and are believed to be genetically related to the Mesozoic Geumsan granitic rocks. Based on their petrogeochemistry and isotopic dating data, the granitic rocks in this district can be classified into two groups ; the Jurassic granitic rocks(equigranular leucocratic granite, porphyritic biotite granite, porphyritic pink-feldspar granite, seriate leucocratic granite) and the Cretaceous granitic rocks(seriate pink-feldspar granite, equigranular alkali-feldspar granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite, equigranular biotite granite). Spatial distribution of fluorite ore deposits, fluorine contents of granitic rocks and fracture patterns in this district suggest that three granitic rocks(equigranular biotite granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite) of the Cretaceous period be genetically related to the fluorite mineralization. In these fluorite-related granitic rocks, fluorine is most highly correlated with Cs(correlation coefficient(r)>0.9), and also highly with MnO, U, Sm, Yb, Lu, Zn, Y, Li(r>0.7). Statistically the variation of fluorine in the fluorite-related granitic rocks can be explained in terros of only three elements, such as Lu, CaO and Cs, and the fluorite-related granitic rocks can be discriminated from the fluorite-nonrelated granitic rocks by a linear functional equation of La, Ce, Cs and F($Z_{Ust}=-1.38341-0.00231F-0.19878Ce+0.38169La+0.54720Cs$). Also, equigranular alkali-feldspar granite is classified into the fluorite-related granitic rocks by means of the linear functional equation($Z_{Ust}$).

• Korean Journal of Microbiology
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• v.16 no.4
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• pp.170-179
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• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.7-18
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• 2015

The characteristics of As and heavy metals depend on the oxidation/reduction condition of the soil environment. The most heavy metals are immobilized by the reduction condition whereas As, Fe and Mn become more soluble. Therefore this study estimated the stabilization efficiency of the agricultural paddy soil in the vicinity of the abandoned mine using a flooded column test including analysis of the soil solution, contaminants fractionation and rice grain. Limestone and steelmaking slag were used as amendments for stabilization of the contaminated soil. In an analysis of the soil solution, the mobile characteristics of Fe and Mn, which were used as electron acceptors of the microorganisms, were controlled by increasing the pH by adding alkali amendments. This means that the contaminants combined with Fe and Mn can be stable under flooded reduction condition. However, the concentrations of cationic heavy metals (Cd, Pb, and Zn) were also decreased without amendments because the carbonates produced from microbial respiration increased the pH of the soil solution. In the amended soil, the specific sorbed fraction of As and carbonates fraction of heavy metals were increased when compared to the control soil at the end of the column test. Especially in heavy metals, the increase of carbonates fraction seems to be influenced by alkali amendments rather than microbial respiration. Because of the stabilization effect in the flooded paddy soil, the contents of As and Zn in rice grain from amended soil were lower than that of the control soil. But additional research is needed because of the relatively higher Pb content identified in the rice grain from the amended.

• Applied Biological Chemistry
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• v.30 no.2
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• pp.133-140
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• 1987

The physicochemical properties and characteristics of potato starches which were isolated from the six varieties were investigated. The ash content of starch prepared from the Arkula showed lower than that of the other five samples. The shapes of starch granules were oval and round, and the average diameters were in the range of $25{\sim}26.9$ microns. The main constituents of the inorganic components of each starch sample were found to be phosphorus and potassium. The amylose contents of starches were between $27.2{\sim}32%$, and blue value, alkali numbers were in the range of $0.42{\sim}0.45$ and $5.8{\sim}7.7$, respectively. Amylograph data revealed that Nook Sack had the highest viscosity at all reference points. The swelling power and solubility patterns were negligible until $50^{\circ}C$, thereafter it increased rapidly.