• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E4
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• pp.203-213
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• 2002

Receptor modeling is one of statistical methods to achieve reasonable air pollution strategies. In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The main purpose of the study was to survey seasonal trends of inorganic elements in the coarse and fine particles. Second, this study has attempted emission sources qualitatively by a receptor method, the PMF mo-del. After that. both PMF (positive matrix factorization) model and TTFA (target transformation factor analysis) model were applied to compare and to estimate mass contribution of coarse and fine particle sources at the receptor. A total of 138 sets of samples was collected from 1989 to 1996 by a low volume cascade impactor with 9 size fraction stages at Kyung Hee University in Korea. Sixteen chemical species (Si, Ca, Fe, K, Pb, Na, Zn, Mg, Ba, Ni, V, Mn, Cr, Br, Cu. Co) were characterized by XRF. The study result showed that the weighted arithmetic mean of coarse and fine particles were 51.3 and 54.4 $\mu\textrm{g}$/㎥, respectively. Contribution of both particle fractions were esti-mated using TTFA and PMF models. The number of estimated sources was seven according to TTFA model and 8 according to PMF model. Comparison of TTFA and PMF revealed that both methodologies exhibited similar trends in their contribution pattern. However, large differences between contributions were observed in some sour-ces. The results of this study may help to suggest control strategies in local countries where known source profiles do not exist.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.179-190
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• 1989

The experimental study for extracorporeal preservation of the heart-lung preparation by autoperfusion system was performed in 10 dogs. Under intravenous Pentothal endotracheal anesthesia bilateral thoracotomies were performed. A 24F cannula connected to a plastic reservoir bag located 100 cm above the level of the heart was introduced into the aortic arch. Left subclavian, innominate artery, and descending aorta were ligated and divided. Both vena cavae were ligated and divided after the bag was half filled with blood. A 24F catheter inserted into right atrium and connected to the plastic bag in order to keep constant the preload. The thoracic trachea was intubated and the lungs were ventilated. The heart-lung preparations were removed en bloc and floated in a $34^{\circ}C$ bath of Hartmann solution. The preparations were observed for from 2 hours to 8 hours, with the average of 5.2 hours. Hemodynamic and hematologic variables were measured during preharvest and autoperfusion. The pH revealed severe respiratory alkalosis due to very low $PaCO_2$ during autoperfusion ; $PaO_2$ remained constant for 130-140 mmHg; $A-aDO_2$ increased markedly. The static inspiratory pressure [SIP] at late autoperfusion [6hr] increased significantly as compared with at early autoperfusion [2hr]. There was no difference between white blood cell counts from right atrium and those of left atrium. Heart rates remained constant for 110-120/min; cardiac outputs maintained to approximately 0.6L/min; mean aortic pressures, 75 mmHg; mean pulmonary arterial pressures, 15-18 mmHg; mean right atrial pressures, 9-13 mmHg; mean left atrial pressures, 12 mmHg lower than those of right atrium. Serum Na maintained with normal range during autoperfusion; K increased significantly; Ca decreased progressively. Hemoglobin and hematocrit decreased significantly during autoperfusion. The study demonstrated that stable hemodynamics could be maintained throughout the experiment and the preparation of the lung seemed to be inadequate, especially after 3-4 hours, such as high $A-aDO_2$, increased SIP, and scattered atelectasis and edema in their gross appearances.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.95-103
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• 2013

PURPOSES : To investigate the fundamental characteristics of blast-furnace slag mortar that was hardened with activating chemicals to capture and sequester carbon dioxide. METHODS : Various mix proportions were considered to find an appropriate stregnth development in regards with various dosages of activating chemicals, calcium hydroxides and sodium silicates, and curing conditions, air-dried, wet and underwater conditions. Flow characteristics was investigated and setting time of the mortar was measured. At different ages of 3, 7 and 28days, strength development was investigated for all the mix variables. At each age, samples were analyzed with XRD. RESULTS : The measured flow values showed the mortar lost its flowability as the activating chemicals amount increased in the scale of mole concentration. The setting time of the mortar was relatively shorter than OPC mortar but the initial curing condition was important, such as temperature. The amount of activating chemicals was found not to be critical in the sense of setting time. The strength increased with the increased amount of chemicals. The XRD analysis results showed that portlandite peaks reduced and clacite increased as the age increased. This may mean the $Ca(OH)_2$ keeps absorbing $CO_2$ in the air during curing period. CONCLUSIONS : The carbon capturing and sequestering activated blast-furnace slag mortar showed successful strength gain to be used for road system materials and its carbon absorbing property was verified though XRD analysis.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.56-64
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• 2015

Acid mine drainage occurrence is a serious environmental problem by mining industry, it usually contains high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of the greatest concern. An indigenous plant extract was used to produce calcium carbonate from Canavalia ensiformis as effective biomaterial, and its ability to form the calcium carbonate under stable conditions was compared to that of purified urease. X-ray diffraction and scanning electron microscopy were employed to elucidate the mechanism of calcium carbonate formation from the crude plant extracts. The results revealed that urease in the plant extracts catalyzed the hydrolysis of urea in liquid state cultures and decreased heavy metal amounts in the contaminated soil. The heavy metal amounts were decreased in the leachate from the treated mine soil; 31.7% of As, 65.8% of Mn, 50.6% of Zn, 51.6% of Pb, 45.1% of Cr, and 49.7% of Cu, respectively. The procedure described herein is a simple and beneficial method of calcium carbonate biomineralization without cultivation of microorganisms or further purification of crude extracts. This study suggests that crude plant extracts of Canavalia ensiformis have the potential to be used in place of purified forms of the enzyme during remediation of heavy metal contaminated soil.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.169-176
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• 2014

To evaluate bio-cementation of microbial on sands, laboratory test was conducted using acrylic cubic molding boxes ($5cm{\times}5cm{\times}5cm$). It was incubated the microbial, called Bacillus Pasteurii, according to Park et al (2011, 2012). and applied 50ml each specimen. Two type of sand samples used were Jumoonjin sand and common sand (well graded). These sands were molded in acrylic boxes with the relative density of 30 % and 60 % respectively. Microbial were poured onto the samples molded in acrylic boxes and cured at the room temperature and humidity. After 7, 14 and 21days, it was measured the compressive strength, pH, EC, and density and it were observed SEM and XRD to verify the effect of bio-cementation. It was found that bio-cementation was increased a strength of sands and it was appeared that strengths were related to the type of sand and relative density. Therefore it was confirmed the solidification of sands using the bio-cementation by microbial activation and the usefullness of acrylic molding boxes when tests were conducted on the soil of sands.

• Journal of Life Science
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• v.9 no.1
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• pp.26-34
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• 1999

A thermostable pullulanase has been isolated and purified from Thermus caldophilus GK-24 to a homogeneity by gel-filtration and ion-exchange chromatography. The specific activity of the purified enzyme was 431-fold increase from the crude culture broth with a recovery of 11.4%. The purified enzyme showed $M_{r}$ of 65 kDa on denaturated and natural conditions. The pI of the enzyme was 6.1 and Schiff staining was negative, suggesting that the enzyme is not a glycoprotein. The enzyme was most active at pH 5.5. The activity was maximal at $75^{\cire}C$ and stable up to $95^{\cire}C$ for 30 min at pH 5.5. The enzyme was stable to incubation from pH 3.5 to pH 8.0 at $4^{\cire}C$ for 24hr. The presence of pullulan protected the enzyme from heat inactivation, the extent depending upon the substrate concentration. The activity of the enzyme was simulated by $Mn^{2+}$ ion, }$Ni^{2+}$, $Ca^{2+}$, $Co^{2+}$ ions. The enzyme hydrolyzed the ${\alpha}$-1,6-linkages of amylopectin, glycogens, ${\alpha}$, ${\beta}$-limited dextrin, and pullulan. The enzyme caused the complete hydrolysis of pullulan to maltotriose and the activity was inhibited by $\alpha$, $\beta$, or $\gamma$-cyclodextrins. The $NH_{2}$-terminal amino acid sequence [(Ala-Pro-Gln-(Asp of Tyr)-Asn-Leu-Leu-Xaa-ILe-Gly-Ala(Ser)] was compared with known sequences of various sources and that was compared with known sequences of various sources and that was different from those of bacterial and plant enzymes, suggesting that the enzymes are structurally different.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.216-219
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• 1997

Thirty day old rice seedlings, Ilpoom and Taeback variety, grown under deficient condition of several elements in nutrition solution of sand culture were exposed to 20Gy, 40Gy, 80Gy of gamma ray $(^{60}Co)$ to study the effect of their radiosensitivity. The results obtained are summarized as follows : Plant height and fresh weight of nutrient deficient rice plants were far less than those of control. The effect was different with nutrient element and rice variety, as show increasing effect of radiosensitivity in the Ilpoom variety was high in the Fe deficient whereas that of Taeback was high in the P deficient. Growth inhibition of rice plant irradiated with 20Gy was highly occurred in the Fe and Zn deficient plot in Ilpoom variety and P and Zn deficient plot in Taeback variety. In 80Gy irradiated group, radiosensitivity of rice plant was high in the P and Ca deficient plot of both Ilpoom and Taeback variety.

• Elastomers and Composites
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• v.38 no.4
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• pp.342-353
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• 2003

This work is about the development of jet-fuel resistant PVC sealant using a polyester plasticizer. PVC copolymer was compounded with adipic acid glycol(Songcizer P-3000) or DOP plasticizers. Fuel-immersed and non-immersed penetration, solubility, flow, and elongation by tensile adhesion of PVC compounds were measured. Penetration increase by fuel immersion and solubility of PVC compounds with adipic acid glycol polyester plasticizer were smaller than those of PVC compounds with DOP plasticizer. Elongation by tensile adhesion test of PVC compound containing 500 phr of Songcizer P-3000 decreased proportionally to the content of DCDP (dicyclopentadiene) base petroleum resin adhesion promoter. Calcium carbonate($CaCO_3$) filler inhibited the diffusion of fuel in all the PVC compounds and decreased the solubility of PVC compounds containing Songcizer P-3000.

• Food Science and Preservation
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• v.7 no.1
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• pp.108-112
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• 2000

Proximate composition , volatile compounds, free amino acids, fatty acids and inorganic compounds in leaf, stem and root of Houttyunia cordata Thunb cultivated from two different area, Bosung and Sunchon , were analyzed. Each part of Houttuynia cordata Thunb from both local area showed moisture contents of 80-84% and crude ash contents of 2.1 ∼2.8%. Crude fat and protein contents were less than 3 % showing slightly higher contents in leaf than in both stem and root . Twenty six volatile compunds were identified from the parts of the plant, the volatile contents were high in the oder of leaf, root and stem. Major volatile compounds were mostly derivatives of decanoic acid ; decanoic acid, 20 tridecanoie, decanal and dodecanoic acid. Of free amino acids in leaf asparagine was the highest, while in stem hydroxyproline, proline and arginine were the major free amino acids. Linoleic acid was the highest in the stem and root, and linolenic acid was highest in leaf. the major minerals of all parts were K, Ca. Mg, P, Fe, Zn and Cu, showing highest with K.

• KSBB Journal
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• v.25 no.6
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• pp.539-546
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• 2010

In this work, mass production of Bacillus licheniformis SCD121067 through medium optimization by statistical experimental method was studied. First, galactose, yeast extract and potassium phosphate dibasic were selected as carbon, nitrogen and phosphate sources for mass production of B. licheniformis SCD121067 by using one factor at a time method. Second, according to the result of Plackett-Burman experimental design, key factors was yeast extract and $K_2HPO$. Finally, the response surface methodology was performed to obtain the optimum concentrations of two selected variables. The optimized medium composition consisted of 20 g/L galactose, 36 g/L yeast extract, 0.41 g/L $K_2HPO4$, 0.25 g/L $Na_2CO_3$, 0.4g/L $MgSO_4$ and 0.01g/L $CaCl_2$. Dry cell weight (15.4 g/L) by optimum production medium were increased 10 times, as compared to that determined with basic production medium (1.5 g/L). Fermentation conditions were examined for the mass production of B. licheniformis. The effect of temperature, agitation speed, pH and aeration rate on the mass production of B. licheniformis were also studied in a batch fermenter which was carried out in a 2.5 L bioreactor with a working volume of 1.5 L containing optimized production medium. As a result, dry cell weight of batch culture was 30.7 g/L at $42^{\circ}C$, 300 rpm, pH 8.0 and 2 vvm.