• Journal of the Mineralogical Society of Korea
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• v.21 no.1
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• pp.37-44
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• 2008

This study was performed to synthesize Na-A type zeolite with melting slag from the Mapo incineration site and recycle the zeolite as an environmental remediation agent. The melting slag used had a favorable composition containing 26.6% $SiO_2$, 10.9% $Al_2O_3$ and 2.7% $Na_2O$ for zeolite synthesis although there were high contents of iron oxides, including 19.6% $Fe_2O_3$ and 18.9% FeO, which had been used as a flux for the melting. It was confirmed that the Na-A type zeolite could be successfully synthesized at $80^{\circ}C$ and $SiO_2/Al_2O_3\;=\;0.80{\sim}1.96$. The cation exchange capacities (CEC) of the zeolites was determined to be about 220 cmol/kg leveled off at the synthetic time more than 10hrs. The adsorption capacities of zeolite to heavy metals (Cd, Cu, Mn and Pb) were high except for As arid Cr. It was also confirmed through the Eh and pH analysis that As and Cr existed in the forms of $HAsO_4^{2-}$ and $CrO_4^{2-}$. The low absorption rates of zeolite for As and Cr are attributed to the fact that the pore size ($4\;{\AA}$) of Na-A type is smaller than those of $HAsO_4^{2-}$ and $CrO_4^{2-}$ ions ($4\;{\AA}$ ionic radii and $8\;{\AA}$ diameter).

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.217-234
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• 2005

혈소판 농축 혈장은 구강과 안면부 재건수술에 새로이 사용되는 유용한 첨가물이다. 혈소판은 상처 치유과정에서 매우 중요하며, 혈소판은 상처부위에 빠르게 도달하여 응고를 형성한다. 그리고 다양한 성장인자를 분비한다. 이러한 성장인자는 골의 형성과 혈관의 증가, 골 이식재의 치유에 관여하는 것으로 생각된다. 본 연구의 목적은 실험 동물을 통하여 혈소판 농축 혈장에 함유된 혈소판의 정량화를 통한 성장인자 함유량을 추정하고, 방사선학적, 조직학적 평가를 통해 혈소판 농축 혈장이 초기의 골형성에 미치는 영향에 대한 평가를 하는데 있다. 15마리의 가토 두개골에 6mm trephine bur(외경 8mm)를 이용하여 경뇌막의 손상을 주지 않도록 하면서 4개의 결손부를 형성하였다. 각각의 두개골 결손부는 $Bio-Oss^{(R)}$만 이식한 군, PRP만 이식한 군, PRP와 $Bio-Oss^{(R)}$를 혼합하여 이식한군, 그리고 아무것도 이식하지 않은 군을 대조군으로 설정하였다. 각각의 재료를 이식한 후 비흡수성 차폐막($Tefgen^{(R)}$)을 위치시키고 흡수성 봉합사로 일차봉합을 시행하였다. 각 군 당 술 후 1, 2, 4주의 치유기간을 설정하였다. 동물을 희생시키고 두개골을 절제하였다. 먼저 방사선학적인 골 밀도 측정을 시행하고, 조직학적 평가를 위해 통법에 따라 조직 표본을 제작한 후 광학현미경으로 관찰하였다. 또한 가토 귀 변연정맥에서 채취한 10 ml의 혈액을 원심분리하여 혈소판 함유량을 평가하여 다음과 같은 결과를 얻었다. 1. 혈소판 농축 혈장은 일반 혈액에 비해 약 4.02배 많은 수의 혈소판이 함유되어 있었다. 2. 방사선적인 평가에서 1, 2, 4주 사이에 대조군과 비교하여 $Bio-Oss^{(R)}$에 PRP를 이식한 군에서 골의 밀도는 큰 차이를 보이고 있다(p<0.01). 하지만, 동일한 시기에 PRP만 이식한 군과 대조군의 차이는 발견할 수 없었으며 (p>0.05), $Bio-Oss^{(R)}$만 이식한 군과 $Bio-Oss^{(R)}$에 PRP를 이식한 군의 차이 또한 발견할 수 없었다(p>0.05). 3. 조직학적 평가에서 모든 이식재는 시간이 경과할수록 골 형성이 증가함을 알 수 있었다. 대조군에 비해 PRP만 이식한 군에서 더 두꺼운 섬유성 결합을 보이고 있다. 대조군과 PRP만 이식한 군과 비교해 $Bio-Oss^{(R)}$와 $Bio-Oss^{(R)}$에 PRP를 혼합 이식한 군에서 골의 형성이 더 진행됨을 알 수 있었다. $Bio-Oss^{(R)}$에 PRP를 혼합 이식한 군이 $Bio-Oss^{(R)}$만 이식한 군에서보다 더 많은 신생골 형성을 관찰할 수 있다. 이상의 결과에서 가토의 두개골 결손부에 $Bio-Oss^{(R)}$에 PRP를 혼합 이식하였을 경우 결손부의 초기 골 형성을 촉진 할 수 있음을 시사하였다.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.79-86
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• 2016

BACKGROUND: This study was initiated to quantitatively evaluate the effects of five heavy metals on the growth and P removal efficiencies of Alcaligenes sp., known as the Phosphorus Accumulating Organisms (PAOs). It was cultivated in the batch system with five heavy metals, such as Cd, Cu, Zn, Pb and Ni, added in single and binary mixtures, respectively.METHODS AND RESULTS: IC₅₀ (half of inhibition concentration of bacterial growth) and EC₅₀ (half of effective concentration of phosphorus removal Efficiencies) were used to quantitatively evaluate the effects of heavy metals on the growth and phosphorus removal Efficiencies of Alcaligenes sp. In addition, Additive Index Value (A.I.V.) method was used to evaluate the interactive effects between Alcaligenes sp. and heavy metals. As a result, as the five heavy metals were singly added to Alcaligenes sp., the greatest inhibitory effects on the growth and P removal efficiencies of each bacteria was observed in the cadmium (Cd). In the binary mixture treatments of heavy metals, the treatments of lowest IC₅₀ and EC₅₀ were the Cd + Cu treatment. Based on the IC₅₀ and EC₅₀ of the binary mixtures of heavy metals treatments, most interactive effects between the heavy metals were found to be antagonistic.CONCLUSION: Based on the results obtained from this study, it appears that they could provide the basic information about the toxic effects of the respective treatments of single and binary mixtures of heavy metals on the growth and P removal efficiencies of Alcaligenes sp. through further study about the characterization of functional proteins involved in toxic effects of heavy metals.

• Korean Journal of Poultry Science
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• v.15 no.1
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• pp.21-29
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• 1988

This study was conducted to obtain more detailed information on the characteristics of body fat distribution, genetic variation and correlation of fat amount at different location in broiler type chicken. A total of 429 offsprings, produced by mating 13 sires with 52 dams of WPR, were used for this study. All experimental analyses were made on dressed carcasses of 8 weeks of age. The average live body weight was 1,856g in male and 1,483g in female, the proportions of each part to live body weight were higher in male group except skin and abdominal fat pad. The total body fat was more in male (40.76g), but fat rate of total body, skin, and abdomen to live body weight were significantly higher in female group. The fat percentages in each body location were significantly higher in the fatty group and in each sex. The rates of abdominal fat to total body fat were increased by fattening, while subcutaneous fat percentages were lowered. There were high correlations between body weight and fat deposit in each location. The genetic correlation coefficients of body weight to fat percentages of skinned carcass, skin, abdomen, and total body fat to live body weight were negative in both sexes, but those to total body fat, eviscerated carcass fat, and skin fat were positive. In conclusion, the fat weight and fat percentage in individual chickens became higher by fattening however, genetic correlation between live body weight and percentages total body fat to live body weight were so low(negative) that decreasing body fat could be possible without decreasing body weight.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.68-76
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• 2002

In this study, we have investigated the geochemical behavior and fate of heavy metals in acid rock drainage (ARD). The ARD was collected from the area of the former Dongrae pyrophyllite mine. The Dongrae Creek waters were strongly acidic (pH : 2.3~4.2) and contained high concentrations of $SO_4$, Al, Fe, Mn, Pb, Cu, Zn, and Cd, due to the influence of ARD generated from weathering of pyrite-rich pyrophyllite ores. However, the water quality gradually improved as the water flows downstream. In view of the change of mole fractions of dissolved Fe, Al and Mn, the generated ARD was initially both Fe- and AA-ich but progressively evolved to more Al-rich toward the confluence with the uncontaminated Suyoung River. As the AR3 (pH 2.3) mixed with the uncontaminated waters (pH 6.5), the pH increased up to 4.2, which caused precipitation of $SO_4$-rich Fe hydroxysulfate as a red-colored, massive ferricrete precipitate throughout the Dongrae Creek. Accompanying the precipitation of ferricrete, the Dongrae Creek water progressively changed to more Al-rich toward downstream sites. At the mouth of the Dongrae Creek, it (pH 3.4) mixed with the Suyoung River (pH 6.9), where pH increased to 5.7, causing precipitation of Al hydroxysulfate (white precipitates). Neutralization of the ARD-contaminated waters in the laboratory caused the successive formation of Fe precipitates at pH<3.5 and Al precipitates at higher pH (4~6). Manganese compounds were precipitated at pH>6. The removal of trace metals was dependent on the precipitation of these compounds, which acted as sorbents. The pHs for 50% sorption ($pH_{50}$) in Fe-rich and Al-rich waters were respectively 3.2 and 4.5 for Pb, 4.5 and 5.8 for Cu, 5.2 and 7.4 for Cd, and 5.8 and 7.0 for Zn. This indicates that the trace metals were sorbed preferentially with increasing pH in the general order of Pb, Cu, Cd, and Zn and that the sorption of trace metals in Al-rich water occurred at higher pH than those in Fe-rich water. The results of this study demonstrated that the partitioning of trace metals in ARD is not only a function of pH, but also depends on the chemical composition of the water.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.331-338
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• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.220-228
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• 2010

This study was designed to examine the effectiveness of an unused tunnel as a rice storage place. The physicochemical changes of rice grains were investigated during 8-months of storage in the tunnel located at Kyungnam province, Korea. Two kinds of tunnel stored rices, NP(rice grown with no pesticides) and LP(rice grown with less pesticides) were compared with $5^{\circ}C$ stored rice as a control. The peroxidase activities, as an index of freshness of rice grains, gradually decreased and NP appeared to be fresher than LP. Whiteness, grain wholeness, and chalkyness were less desirable for the tunnel stored rice than the control, with no significant difference of physicochemical properties, including the broken, damaged, colored rice, and contents of moisture, protein, and amylose. Palatability dropped below 70 in all three groups at later phase. The sensory evaluation showed that overall preference was slightly higher for the control but not significantly different from the other two groups. From all the evidences shown, unused tunnels may be an effective place for a long-term rice storage, since the average temperature inside the tunnel was maintained very constantly around $14.3^{\circ}C$ and relative humidity was optimal for rice storage, especially during spring and summer seasons.

• Applied Biological Chemistry
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• v.8
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• pp.51-59
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• 1967

A split plot was laid out in 1965 for perennial application of straw by 500kg per 10 are, as main plot, and of chemical fertilizer in conventional way, as sub-plots. The sub-plot included the following 5 fertilizer treatments as (1) non-fertilized, (2) nitrogen-free, (3) phosphate-free (4) potassium-free, (5) completely fertilizer applied plots. Trends in the growth and yield of rice was observed at present experimental site in the first year, 1965, and second year, 1966, as follows: 1. Each treatmental plot showed nearly identical trends between the first and second year, in term of growth, yield and yield components. 2. Straw application deterred the initial growth at non-fertilized and nitrogen-free plots. But straw application raised the effective stem ratio and enlarged the values in yield components, finally to be resulted in the second year with significant difference. 3. Both phosphate and potassium did not much affected to plants for longer stem and larger number of tillers. 4. Effect of nitrogen, phosphate and potassium was recorded as investigated by previous research works. Phospate deficiency decreased maturing rate to a great extent. 5. Numerical index was calculated for the comparison of plots in yield, where the non-straw, completely fertilizer applied plot stands for 100. The indexes of the first and second year were as follows : at non-straw plot(indexes in the blank are from the first year trial); non-fertilized : 80.2(80.9), nitrogen-free: 83.6(89.4), phosphate-free : 89.4(93.1) and potassium-free plot: 93.5(102.4) at non-straw plot. On the other hand, indexes at straw applied plots were non-fertilized : 84.0(86.6), nitrogen-free 82.6(93.9), phosphate-free : 91.7(96.3), potassium-free: 103.2(102.0) and complete plot: 98.7(109.8).

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.87-96
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• 2007

Risk assessment was carried out in order to improve the remediation and management strategy on a contaminated gunnery site, where a flood control reservoir is under construction nearby. Six chemicals, including explosive chemicals and heavy metals, which were suspected to possess risk to humans by leaching events from the site were the target pollutants for the assessment. A site-specific conceptual site model was constructed based on effective, reasonable exposure pathways to avoid any overestimation of the risk. Also, conservative default values were adapted to prevent underestimation of the risk when site-specific values were not available. The risks of the six contaminants were calculated by API's Decision Support System for Exposure and Risk Assessment with several assumptions. In the crater-formed-area(Ac), the non-carcinogenic risks(i.e., HI values) of TNT(Tri-Nitro-Toluene) and Cd were slightly larger than 1, and for RDX(Royal Demolition Explosives), over 50. The total non-carcinogenic risk of the whole gunnery range calculated to a significantly high value of 62.5. Carcinogenicity of Cd was estimated to be about $10^{-3}$, while that of Pb was about $5\;{\times}\;10^{-4}$, which greatly exceeded the generally acceptable carcinogenic risk level of $10^{-4}{\sim}10^{-6}$. The risk assessment results suggest that an immediate remediation practice for both carcinogens and non-carcinogens are required before the reservoir construction. However, for more accurate risk assessment, more specific estimations on condition shifts due to the construction of the reservoir are required, and more over, the effects of the pollutants to the ecosystem is also necessary to be evaluated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.146-150
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• 2011

A large amount of nitrogenous compounds are found in burley tobacco and are responsible for peculiar aroma during smoking. Excess in nitrogen or its compounds such as total nitrogen and proteins in burley tobacco gives a strong pungency and make its taste bad. The present study has focused on improving quality of Burley tobacco by regulating topping and harvesting time of leaf to reduce nitrogen compounds in Burley tobacco. In addition, the early-stage of flower topping had lower level of nitrogenous compound, such as total nitrogen and protein nitrogen, and total tobacco-specific nitrosamine (TSNA) contents compared to the button-stage and full flower-stage topping. Also, the contents of nicotine got significantly decreased while the ether extract was increased as the period of topping got delayed. Regarding the brightness among the colors of cured leaves, the color at the full flower-stage topping was the brightest, and there was no particular difference in red and yellow colors. The harvesting amount was decreased as the period of topping got delayed and there was no significant difference between the topping treatments in terms of the exterior quality. As the harvesting time delayed, the total nitrogen, protein nitrogen, nitrate nitrogen, and ammonium nitrogen were decreased while the nicotine contents got increased. Also, the total TSNA contents were decreased as the harvesting time delayed. However, ether extract was increased. Among the colors of cured leaves, the brightness and degree of yellow color were significantly increased as the harvesting time delayed, and there was no particular difference in the degree of red color. The harvesting amount was decreased along with the delayed harvesting time; however, the harvest of the matured and mellow leaves was higher in terms of price, compared to that of the immature leaves. For the reduction of nitrogenous compound and TSNA contents in Burley tobacco, the topping was examined to be more effective in terms of improvement in chemical contents and quality regardless of the decreased harvesting amount.