• Applied Biological Chemistry
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• v.32 no.4
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• pp.386-392
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• 1989

The adsorption of $NH_4\;^+$ and $Zn^{2+}$ by four Korean zeolites, the major species of which are clinoptilolite, clinoptilolite with mordenite, mordenite with clinoptilolite, and mordenite was measured in different concentrations of solutions of $NH_4\;^+$ and $Zn^{2+}$, and their mixtures. The adsorption of $NH_4\;^+$ was greater than that $Zn^{2+}$ far all samples at the concentrations of the added solutions from $1\;to\;7{\times}10^{-3}N$ and this difference was greater at the higher concentrations. Also, $Zn^{2+}$ adsorption by samples was decreased by the presence of $NH_4\;^+$, but that of $NH_4\;^+$ by the presence of $Zn^{2+}$ was not. The extent of $NH_4\;^+$ selectivity among samples was increased in order of clinoptilolite with mordenite$NH_4\;^+$ adsorbed by six successive equilibrations with the solution containing both $NH_4\;^+$ and $Zn^{2+}$ each at a concentration of $3{\times}10^{-3}N$ were in range from 43.7 to 50.4 me/100g, whereas those amounts of $Zn^{2+}$ were in the range from 6.6 to 17.0 me/100g. It was suggested from these results that mordenite and clinoptilolite, particularly the former, can be used for removal of $NH_4\;^+$ from municipal wastewater and those zeolites treated with wastewater can be applied to agricultural land.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.643-651
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• 2006

The Pb-Ag-Bi-S system minerals such as galena-matildite solid solutions, cosalite and heyrovskyite occur in the Nakdong As-Bi deposits. Galena-matildite solid solutions commonly coexisting with native bismuth fill in microfractures of pyrite grains and form irregular shapes. Cosalite forms composite grains including native bismuth, heyrovskyite and Bi-Te-S system minerals in the matrix of quartz vein. Matildite from the Nakdong deposits has an end member composition, $Ag_{1.07-1.11}Bi_{1.12-1.20}S_2$, and an excess concentration of $0.3{\sim}2.4$ mole % $Bi_2S_3$ compared to the stoichiomeoic value. PbS concentrations in $PbS-AgBiS_2$ solid solutions do not exceed 54 mole %. The average chemical composition of cosalite in the study area is $Pb_{1.79}Bi_{2.29}Ag_{0.12}S_5$. Pb is slightly depleted compared to the ideal composition, but the concentrations of Ag and Cu reach as much as 1.47 wt.% and 0.27 wt.%, respectively. Heyrovskyite has the chemical formula of $Pb_{5.01}Ag_{0.26}Bi_{2.70}S_9$ suggesting that there occurs the coupled substitution of $2Bi^{3+}$ for $3Pb^{2+}$ as well as that of $Ag^++Bi^{3+}$ for $2Pb^{2+}$. The genetic condition of Pb-Ag-Bi-S system minerals can be confined to the temperature of $220{\sim}270^{\circ}C$ and the pressure below 200 bars.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.11
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• pp.101-109
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• 2009

Generally, depth cache and pixel cache of 3D graphics are designed by using write-back scheme for efficient use of memory bandwidth. Also, there are write after read operations of same address or only write operations are occurred frequently in 3D graphics cache. If a cache miss is detected, an access to the external memory for write back operation and another access to the memory for handling the cache miss are operated simultaneously. So on frequent cache miss situations, as the memory access bandwidth limited, the access time of the external memory will be increased due to memory bottleneck problem. As a result, the total performance of the processor or the IP will be decreased, also the problem will increase peak power consumption. So in this paper, we proposed a novel early write back cache architecture so as to solve the problems issued above. The proposed architecture controls the point when to access the external memory as to copy the valid data block. And this architecture can improve the cache performance with same hit ratio and same capacity cache. As a result, the proposed architecture can solve the memory bottleneck problem by preventing intensive memory accesses. We have evaluated the new proposed architecture on 3D graphics z cache and pixel cache on a SoC environment where ARM11, 3D graphic accelerator and various IPs are embedded. The simulation results indicated that there were maximum 75% of performance increase when using various simulation vectors.

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.311-315
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• 2004

The brown planthopper, Nilaparvata lugens, is among the most serious insect pests of rice. It is widely distributed in Asia, Australia and Pacific islands. An earlier mitochondrial DNA study revealed that there exist significant genetic differences between populations north and south of the Red River Delta region in Vietnam. However the mitochondrial DNA was not sufficiently variable to examine the sources of immigration. For a more detailed analysis of geographic population structure of N. lugens, we developed microsatellite markers. Thirty-seven putative microsatellite loci were isolated using a magnetic biotin method, and five primer pairs designed from the flanking regions of sequenced microsatellite clones were labeled with fluorescent. Of these five primer sets, two have proven to be useful across all the samples we used in this study. We used variation at these two microsatellite loci to test the hypothesis that N. lugens biotypes (1, 2, and 3) sampled from laboratory selection constituted distinct genetic units. Allele frequency differences among the three major biotype categories were not significantly different at one locus (27035). However, the other (7314) did show differences among the major three biotypes. The methods we describe here will be useful for studying population structure of crop pest and for tracking the patterns of migratory pest like the rice planthoppers.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.163-176
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• 2009

The pyrophyllite deposits located in Jinhae area have been studied through field observations and laboratory works including the X-ray diffraction (XRD), X-ray fluorescence (XRF), Electron probe microanalyzer (EPMA) and Inductively Coupled Plasma (ICP). The pyrophyllite deposits consist of mainly illite, dickite, pyrophyllite, diaspore, chlorite, pyrite and copiapite. According to the mineral assemblages, geological occurrences and alteration modes, the altered rocks can be classified into four types: Type A; quartz with silicifictaion, Type B; quartz + illite with illitization, Type C; quartz + dickite + illite with kaolin alteration, Type D; pyrophyllite + illite + dickite + diaspore with pyrophyllite alteraion. Rocks in Type A, which is generated by silicifictaion, have high $SiO_2$ contents more than 90 wt% and distinctive equigranular textures with microcrtstalline quartz. The pyrophyllites from the study area belong to 2M polytype. The host rocks of the pyrophyllite ore in this mine are rhyolitic rock, andecitic tuff and volcanic breccia. The alteration products seem to be controlled by the different lithology of the host rocks. The hydrothermal solution formed the deposits would be inferred to the acidic and have relatively high ionic activity of hydrogen and silica judging from alteration mineral assemblage. Pyrophyllite alteraion zone is generated by highest temperature condition of all alteration zone.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.123-129
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• 2016

This study is conducted to estimate the firing temperature and condition of the 4-6th Century earthenwares excavated from the ancient tombs in the Seonggok-ri, Cheongdo through mineralogical approaches, and to contrast to the characteristics of the earthenware from the Changnyeong the adjacent area to the Cheongdo. The Cheongdo earthenware was mainly composed of quartz, pores and vitric matrix with minor parts of feldspars, felsic volcanic fragments and opaque minerals, of which quartz crystals frequently show embayed texture and pores was partly filled with amorphous quartz. Mullite, hematite and cristobalite were found by XRD spectrometer additionally, and in the SEM image the Mullite contents are evenly distributed from the central part to the marginal part. As a result, the firing temperature of the Cheongdo earthenware could be 1,100 to $1,200^{\circ}C$, which is higher than that of the Changnyeong. Distribution characteristics of mullite in the Cheongdo and the Changnyeong earthenware indicate that the Cheongdo earthenware was under the longer firing time or more homogeneous thermal condition in the kiln than the Changnyeong.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.72-78
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• 2016

BACKGROUND: Entomopathogenic fungi have been studied to develop for biological control agents as an alternative to chemical control agents in insect pest management. This investigated to determine the optimal culture conditions in ceramic balls for maximal sporulation of entomopathogenic fungi Beauveria bassiana M130 by use rice bran extract.METHODS AND RESULTS: METHODS AND RESULTS: A culture of entomopathogenic fungi for 12day on rice bran extract(1:8, w/v) incubated in ceramic matrix at 28℃. Natural zeolite ceramic ball was high production of 4.2×108 conidial/mL. The culture condition optimized initial pH, temperature, rice bran extract concentration, adhesives substance and concentration of NaCl, respectively. The high production of spore optimal conditions were temperature 28℃, initial pH 3, rice bran extract 3 mL, starch 33 g, 5 % NaCl and sopre suspension 7 mL, respectively.CONCLUSION: This study was carried out for the mass production of entomopathogenic fungi conidia recover rate 65% in matrix of natural zeolite ceramic ball, and to develop ingredient-used formulation of Beauveria bassiana M130 conidia for biological control agents.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.75-95
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• 2002

The Andong pluton in the Andong Batholith is composed of comagmatic plutonic rocks, in which the lithofacies comprise hornblende biotite tonalite in the central paft biotite granodiorite in the marginal paft and porphyritic biotite granite at the topside (noJthea~tern paft) of the pluton. The pluton is petrographically and petrochemically zoned, having more mafic center than margin and topside. Distribution pallern of the lithofacies represents a reverse zoning in the pluton. Modal and chemical data in the pluton show progressive and gradual compositional variations from the centrer via the margin to the topside. Quartz and K-teldspar increase toward the topside of the pluton, whereas hornblende, biotite and color index increase toward the center. The bulk composition in the pluton is also reversely zoned, with high $Si0_2$ and $K_{2}O$ in the topside facies, and high MnO, CaO, $Ti0_2$, $Fe_{2}O_{3}$t, MgO and $P_{2}O_{5}$ in the central facies. The reverse zoning is also evident in higher Cr. V, Ni, Sc and Sr of the more mafic tonalite in the interior. The reversely zoned pluton results from remobilization (resurgence) of the lower more mafic compositional zone into the upper more felsic zones of the pluton modified by thennogravitational diffusion and fractional crystallization. In the initial stages of evolution, the pluton was a petrochemical system that fonned chemical compositional zonation with mafic tonalitic magma in the lower. granodioritic one in the middle and granitic one in the upper paft of the magma chamber. Periodic influxes of more mafic magma from the ba~e resulted in mingling of liquids and redistribution of minerals, and may have triggered the remobilil.ation of the lower compositional zone into the upper more felsic zones.

• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.123-129
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• 2010

A study on modeling of medium temperature drops of the elevated-bench hydroponic system for strawberry cultivation during low temperature season was conducted. Four different conditions were used for the experiment. These consisted of two kinds of bed types (plant, V), four kinds of medium (rice, perlite, rice hulls80% and peatmoss20%, perlite80% and peatmoss20%), two kinds of mulched bed (mulched, non mulched) and four kinds of greenhouse air temperature (l.5, 3.2, 5.0, $6.7^{\circ}C$), and the results were summarized as follows: Temperature drop of medium in the V-bed was slower than that in the plant bed, showing better insulation effect of V-bed. Temperature drop of medium with mulching on the top of the bed was slower than the case without mulching, as a result, the beneficial effect of temperature drop was appeared in mulched bed. Linear regression of the temperature descent rate and the temperature difference between medium and air showed significant correlation. The regression equation for the Pearlite80% and Peatmoss20% in the V-bed was f(x) = -0.2656 + 0.1345x at the $R^2$ of 0.9269. Using the model, the temperature drop during night can be predicted for the various media at the different depths.

• Journal of the Korean Institute of Gas
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• v.9 no.2 s.27
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• pp.50-55
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• 2005

The compositional and structural properties of alkali metal ion exchanged Y-zeolites have been investigated by la number of analytical techniques and their catalytic activities were tested for NOx reduction in combination with a non-thermal plasma. The NOx conversion data for LiY, NaY, KY and CsY were measured by chemiluminiscent NOx meter in the temperature range of 100 to $350^{\circ}C$. The initial activities of the catalyst at $150^{\circ}C$ increased in the order LiY < KY < NaY < CsY in alkali series. The activity of CsY and NaY were increased and showed maximum at $200^{\circ}C$ and then decreased in the plasma reactor, as the temperature increased. The activity of KY maintained same by $200^{\circ}C$ and then decreased, whereas the activity of LiY decreased with the increasing temperature. The CsY catalyst, which showed the highest activity in alkali metal series, exhibits a NOx conversion efficiency of $80\%$ between $170{\~}220^{\circ}C$.