• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.131-139
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• 2004

In this study, on-site sewage treatment tests were conducted using the Absorbent Biofilter System (ABS) under different hydraulic loading rates to examine its treatment characteristics and efficiencies and to determine its feasibility as a small on-site sewage treatment system in a rural area. Results showed that the removal rates of BOD and SS were satisfactory at hydraulic loading rates of 100~150 cm/day, meeting the Korean effluent water quality standards for the riparian zone (10 mg/L). In the case of nutrients (N, P), however, the system did not perform well, necessitating further improvement for nutrient removal. A comparative analysis indicated that as a small on-site sewage treatment system, the ABS would be more suitable than other treatment systems in terms of performance stability, maintenance requirement, and cost-effectiveness and could be applied as an alternative treatment system in Korean rural areas.

• BMB Reports
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• v.33 no.1
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• pp.69-74
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• 2000

The Arabidopsis thaliana S-Adenosylmethionine decarboxylase (AdoMetDC) cDNA ($GenBank^{TM}$ U63633) was cloned, then the AdoMetDC protein was expressed and purified. The purified AdoMetDC was inactivated by salicylaldehyde in a pseudo first- order kinetics. The secondorder rate constant for inactivation was 126 $M^{-1}min^{-1}$ with the slope of n=0.73, suggesting that inactivation is the result of the reaction of one lysine residue in the active site of AdoMetDC. Site-specific mutagenesis was performed on the AdoMetDC to introduce mutations in conserved $lysine^{81}$ residues. These were chosen by examination of the conserved sequence and proved to be involved in enzymatic activity by chemical modification. Changing $Lys^{81}$ to alanine showed an altered optimal pH. The substrate also provided protection against inactivation by salicylaldehyde. Considering these results, we suggest that the $lysine^{81}$ residue may be involved in catalytic activity.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.294-299
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• 2006

Mt. Seokseong is located $37^{\circ}15'15'{\sim}37^{\circ}17'00'N$ in latitude at $127^{\circ}09'30'{\sim}127^{\circ}11'00'E$ in longitude in Yongin-si. As the result of cluster analysis, B site has 170 taxa of vascular plants, so it is the most abundant site in this area. And C site has 140 taxa of that, it is secondly abundant. But it has the highest similarity index (53.7%) between A site and B site. To construct natural resort for residents, it needed make thorned park just as hiking course, woods bathing site, aquatic place, pebble path, and natural garden path. And to protect ecological isolation of this area ecobridges must be constructed at Myeokjogogae and at Yongin Medical Hospital.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.4 s.44
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• pp.29-42
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• 2005

Total 350 borehole profiles were selected from the database of borehole logs in Seoul, for the site-specific seismic evaluation at two 4km${\times}$4km plain areas. Equivalent-linear site response analyses for the selected 350 sites were conducted based on shear wave velocity (Vs) Profiles, which were determined from the N-Vs correlation established using borehole seismic testing results in the inland areas of Korea. Most sites were categorized as site classes C and D based on the mean Vs to 30 m in depth (Vs30) ranging from 250 to 550 m/s. The she periods of the plains in Seoul ranging between 0.1 and 0.4 sec were significantly lower than those of the western US, from which the site coefficients in Korea were derived. For plains in Seoul, the site coefficients, Fa's and Fv's specified in the Korean seismic design guide, underestimate the ground motion in short-period (0.1-0.5 sec) band and overestimate the ground motion in mid-period (0.4-2.0 sec) band, respectively, because ol the differences in the geotechnical conditions between Seoul and the western US, although the Fa's in several sites overestimate the motion due to the base Isolation effect resulted from the soft layer in soil deposit.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.321-325
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• 1996

Quantum chemical calculations are used to characterize the decomposition of nitrogenmonoxide over $Cu^{n+}$-Y zeolite. The method of theoretical calculations, such as CNDO/2, have been applied to cluster models representing cation sites in zeolite to obtain total energies, LUMO energies, and Wiberg bond orders. The calculated total energies and bond orders of cluster models showed the reaction mechanism of NO decomposition over $Cu^{n+}$ site in zeolite framework. The suggested cluster models of varying Si/Al ratios studied with exchange cations in the $Cu^+$ and in the $Cu^{2+}$ states. And the calculated LUMO energies can predict L acidifies of cluster models. The results from these experiments showed the possibility of the mechanism of NO decomposition, progressing adsorption of NO, conversion to $N_2$ and $O_2$, desorption of $N_2$ and $O_2$ in sequence. The L acidity of $Cu^{2+}$ ion in cation site is more strong than $Cu^+$.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.129-133
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• 2015

Purpose: The purpose of this study is to evaluate the surgical outcome of duodenal injuries and to analyze the risk factors related to the leakage after surgical treatment. Methods: A retrospective review of 31 patients with duodenal injuries who managed by surgical treatment was conducted from December 2000 to May 2014. The demographic characteristics, injury mechanism, site of duodenal injury, association of intraabdominal organ injuries, injury severity score (ISS), abdominal abbreviated injury scale (AIS), injury-operation time lag, surgical treatment methods, complications, and mortality were reviewed. Results: Duodenal injury was more common in male. Twenty four (77.4%) patients were injured by blunt trauma. The most common injury site was in the second portion of the duodenum (n=19, 58.6%). Fourteen patients (45.2%) had other associated intraabdominal organ injuries. The mean ISS is $13.6{\pm}9.6$. The mean AIS is $8.9{\pm}6.5$. Eighteen patients (58.1%) were treated by primary closure. The remaining 13 patients underwent various operations, including exploratory laparotomy (n=4), pancreaticoduodenectomy (n=3), pyloric exclusion (n=3), Resection with end-to-end anastomosis (n=2), and duodenojejunostomy (n=1). Most common postoperative complications were intraabdominal abscess (n=9) and renal failure (n=9). Mortality rate was 9.7%. Conclusion: ISS, AIS>10, operative time, pancreaticoduodenectomy, sepsis, and renal failure are significant predictors of a postoperative leak after duodenal injury. Careful management is needed to prevent a potential leak in patient with these findings.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.53-63
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• 1998

Total of 1085 swine sera (1996-1997) from nation-wide were tested for the presence of antibodies to influenza A virus. Fifty nine percent of the tested sera showed seropositive by HI test. Positive sera consisted of 24--- of H3, 15--- of H1, and 20--- of the sample had both antibodies, respectively. Sera collected from various region represented 7~27--- seropositivity to H1N1, 15~25--- to H3N2, respectively. Swine influenza field isolate from nasal swab was characterized antigenically and genetically to elucidate its relatedness with other known strains of influenza A virus. The study was focused on the HA gene which is related to pathogenecity and antigenic variability of the influenza virus. By RT-PCR using influenza A/H1N1 specific primers, influenza virus H1N1 specific DNA fragment was amplified from A/Swine/Iowa/15/30(H1N1), US field isolate but not in H3N2 strain. PCR products were sequenced by dideoxy chain termination method to determine nucleotide homology with other strains of influenza A virus. The US field isolate and A/Swine/Indiana/1726/88 strain had 97--- of nucleotide homology and 98--- of amino acid homology. Based on the results obtained from this experiment, the field isolate was genetically related to A/Swine/Indiana/1726/88 and had higher homology with A/Swine/Indiana/1726/88 than with classical swine influenza virus, A/Swine/Iowa/15/30. The field isolate had no amino acid changes at the antigenic site compare to that of the A/Swine/Indiana/1726/88. The proteolytic enzyme cleavage site between HA1 and HA2 had no alteration and the amino acid arginine was intact. There is no evidence has been found that the field isolate has genetic shift or genetic drift which might altered antigenic determinant.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.901-907
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• 2008

Thermotoga neapolitana $\beta$-glucosidase (BglA) was subjected to site-directed mutagenesis in an effort to increase its ability to synthesize arbutin derivatives by transglycosylation. The transglycosylation reaction of the wild-type enzyme displays major ${\beta}(1,6)$ and minor ${\beta}(1,3)$ or ${\beta}(1,4)$ regioselectivity. The three mutants, N291T, F412S, and N291T/F412S, increased the ratio of transglycosylation/hydrolysis compared with the wild-type enzyme when pNPG and arbutin were used as a substrate and an acceptor, respectively. N291T and N219T/F412S had transglycosylation/hydrolysis ratios about 3- and 8-fold higher, respectively, than that of the wild-type enzyme. This is due to the decreased hydrolytic activity of the mutant rather than increased transglycosylation activity. Interestingly, N291T showed altered regioselectivity, as well as increased transglycosylation products. TLC analysis of the transglycosylation products indicated that N291T retained its ${\beta}(1,3)$ regioselectivity, but lost its ${\beta}(1,4)$ and ${\beta}(1,6)$ regioselectivity. The altered regioselectivity of N291T using two other acceptors, esculin and salicin, was also confirmed by TLC. The major transglycosylation products of the wild type and N291T mutant were clearly different. This result suggests that Asn-291 is highly involved in the catalytic mechanism by controlling the transglycosylation reaction.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.643-650
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• 2005

In order to treat leachate from aged landfill site effectively, removal of biologically recalcitrant organic matter and denitrification efficiency were evaluated through the combination of $H_2O_2/O_3$ AOP pretreatment process and UASB process. The results can be summarized as follows. In case of leachate having low COD/N ratio from aged landfill site, it is possible to increase available COD for denitrification in nitrate utilizing denitrification and nitrite utilizing denitrification both by enhancing biodegradability of recalcitrant organic matter as applying $H_2O_2/O_3$ AOP to pretreatment process. In this experiment, it is found that available COD for denitrification can be increased to 1.0 and 0.4 g/day, respectively. Comparison has been made between requiring COD and available COD for denitrification in each experimental stages. It is expected that high rate of denitrification can be achieved with leachate from young landfill site because higher amount of available COD for denotrification is present in the leachate than the amount of requiring COD for denitrification. Especially, In leachate from aged landfill site with low COD/N ratio, it can be concluded that denitrification using nitrite nitrogen can enhance overall denitrification performance efficiently because denitrification using nitrite nitrogen requires less amount of carbon source than denitrification using nitrate nitrogen. Comparing the biogas production rate and nitrogen content of biogas under the condition of same amount of nitrate and nitrite addition, biogas production and nitrogen content of biogas are increased during denitrification after $H_2O_2/O_3$ AOP pretreatment process. Therefore, it can be confirmed that COD/N ratio in the leachate is increased. Applying $H_2O_2/O_3$ AOP as pretreatment system of landfill leachate seems to have little economic benefit because it requires additional carbon source to denitrify ammonia nitrogen in leachate coming from aged landfill site. However, it is possible to apply this pretreatment process to leachate from old landfill site in view of AOP process can achieve removal of biologically recalcitrant organic matter and increase of available COD for denitrification simultaneously.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1095-1102
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• 2011

The effect of mixed cultivation with green manure crops and liquid pig manure on rice growth was investigated. Field experiment in site 1 (Astragalus sinicus L.) and site 2 (Lolium multiflorum Lam.) were designed with control (non-green manure crop), PLM 100 (non-green manure crop + liquid pig manure 100%), A(L)PLM 0 (green manure crop + PLM 0%), A(L)PLM 50 (green manure crop + PLM 50%), A(L)PLM 75 (green manure crop + PLM 75%), and A(L)PLM 100 (green manure crop + PLM 100%). The results of 1,000 grain in rice plant were in the order of APLM 100 ${\geqq}$ APLM 75 ${\fallingdotseq}$ PLM 100 ${\fallingdotseq}$ APLM 0 ${\fallingdotseq}$ APLM 50 ${\fallingdotseq}$ control for site 1 and LPLM 100 ${\geqq}$ LPLM 75 = LPLM 50 = PLM 100 ${\geqq}$ LPLM 0 ${\fallingdotseq}$ control for site 2. The yields of rice in site 1 and site 2 were $636kg\;10a^{-1}$ (increasing yield 10%) for APLM 100 and $775kg\;10a^{-1}$ (increasing yield 12%) for LPLM 100, respectively.