• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.436-442
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• 2017

Fischer-Tropsch synthesis is the technology of converting a syngas (CO+$H_2$) derived from such as coal, natural gas and biomass into a hydrocarbon using a catalyst. The catalyst used in the Fischer-Tropsch synthesis consists of active metal, promoter and support. The types of these components and composition affect the reaction activity and product selectivity. In this study, we manufactured an iron catalyst using ${\gamma}-Al_2O_3/SiO_2$ mixed support (100/0 wt%, 75/25 wt%, 50/50 wt%, 25/75 wt%, 0/100 wt%) by an impregnation method to investigate how the composition of ${\gamma}-Al_2O_3/SiO_2$ mixed support effects on the reaction activity and product selectivity. The physical properties of catalyst were analyzed by $N_2$ physical adsorption and X-Ray diffraction method. The Fischer-Tropsch synthesis was conducted at $300^{\circ}C$, 20bar in a fixed bed reactor for 60h. According to the results of the $N_2$ physical adsorption analysis, the BET surface area decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the pore volume and pore average diameter increase as the composition of ${\gamma}-Al_2O_3$ decreases except for the composition of ${\gamma}-Al_2O_3/SiO_2$ of 50/50 wt%. By the results of the X-Ray diffraction analysis, the particle size of ${\alpha}-Fe_2O_3$ decreases as the composition of ${\gamma}-Al_2O_3$ decreases. As a result of the Fischer-Tropsch synthesis, the CO conversion decreases as the composition of ${\gamma}-Al_2O_3$ decreases, and the selectivity of C1-C4 decreases until the composition of ${\gamma}-Al_2O_3$ was 25 wt%. In contrast, the selectivity of C5+ increases until the composition of ${\gamma}-Al_2O_3$ is 25 wt%.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.279-285
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• 2005

Background : Ambient particles during Asian dust events are usually less than $10{\mu}m$ in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. Methods : Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. Results : One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of $148.0{\mu}g/m^3$. The 24 hour average PM10 level was $57{\mu}g/m^3$. There was a significant difference in the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. Conclusions : Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

• Journal of Life Science
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• v.30 no.10
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• pp.886-895
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• 2020

The development of novel peptide antibiotics with potent antimicrobial activity and anti-inflammatory activity is urgently needed. In a previous work, we performed an in-silico analysis of the Papilio xuthus transcriptome to identify putative antimicrobial peptides and identified several candidates. In this study, we investigated the antibacterial and anti-inflammatory activities of papiliocin 3, which was selected bioinformatically based on its physicochemical properties against bacteria and mouse macrophage Raw264.7 cells. Papiliocin 3 showed antibacterial activities against E. coli and S. aureus without inducing hemolysis and decreased the nitric oxide production of the lipopolysaccharide-induced Raw264.7 cells. Moreover, ELISA and Western blot analysis revealed that papiliocin 3 reduced the expression levels of pro-inflammatory enzymes, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE₂). In addition, we examined whether papiliocin 3 could inhibit the expression of pro-inflammatory cytokines (interleukin-6 and interleukin-1β) in LPS-induced Raw264.7 cells. We found that papiliocin 3 markedly reduced the expression level of cytokines through the regulation of mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB) signaling. We also confirmed that papiliocin 3 binds to bacterial cell membranes via a specific interaction with lipopolysaccharides. Collectively, these findings suggest that papiliocin 3 could be a promising molecule for development as a novel peptide antibiotic.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.1-8
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• 2009

This study was conducted to investigate the effect of rainfall, irrigation and fertilizer application on water qualities of pond in golf course from May in 2007 year to November in 2008 year. For survey of water quality, it was sampled at $10{\sim}12$ sites(irrigation site 2, drainage site 3, and hazard site $5{\sim}7$) of SKY72 G.C and evaluated with analysis items such as pH, electrical conductivity(EC), DO, SS, T-N, $PO_4$-P, K, Ca, Mg, Na, SAR, BOD and COD. Results obtained were summarized as follows: The value of pH, EC, DO, T-N, P04-P, K, Ca, Mg, Na and SAR was in dry season, but those of SS, BOD and COD in the rainy season. N and P concentration of pond water showed $1.2{\sim}28.8mg/L$ and $0.005{\sim}0.172mg/L$, respectively, and so it was higher than eutrophication level of lakes and marshes recommended by the Ministry of Environment in Korea. As a reault of correlation analysis, EC in the water was significantly(P<0.01) related items such as K, Ca, Mg, Na, SAR and salinity, and SS significantly(P<0.05) BOD and COD. In comparison with a corelation between respective analysis items and rainfall amount, SAR was significantly(P<0.01) positive but T-N negative(P<0.01). As compared with corelation between respective items and irrigation amount, pH was significantly(P<0.01) positive but T-N(P<0.05) and BOD(P<0.01) negative. When it was applied to N, $P_2O_5$ and $K_2O$ in golf course, N and $K_2O$ significantly affected water qualities of pond(P<0.01). These results suggested that a pond water in golf course was affected by the fertilizer application, rainfall and irrigation and EC was adequate monitoring indicator for the evaluating water quality of pond by chemicals influent.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.9-24
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• 1997

Surfactant-aided in situ soil flushing has been proposed as an alternative for the expensive and time consuming 'pump and treat' technology in remediation of contaminated soil and groundwater Injected surfactants can effectively solubilize contaminants sorbed to the soil matrix or nonaqueous phase liquids(NAPLs) in residual saturation. The contaminants solubilized in groundwater are recovered and treated further. The theoretical background of the technology and the results of the field operations, mostly in the US. were summarized. In addition, the factors crucial to the successful application of the technology were discussed. Cost analyses and technical limitations in current applications were also discussed. In conclusion, it is likely that in situ surfactant flushing become a viable option for soil remediation in limited cases. Currently, further advances with respect to operation cost and to treatment efficiency are required for more extensive application of the technology. However, the current trends in soil remediation, specially the growing emphasis on risk based corrective action and natural attenuation, will increase the competitiveness of the technology. For example, removal of easily washable contaminants by short term soil flushing followed by long term monitoring and natural attenuation can greatly reduce the operation cost and time.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.277-289
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• 2006

This study was carried out to find a new material having high removal efficiency for the harmful red tide. C. polykrikoides grow very fast and accumulate into dense and visible patches near the surface of the seawater ('Water bloom'). Some mineral medicines and Hwangto (reddish soil consist of clay minerals and Fe-oxides) were used in this study to remove C. polykrikoides. The pre-determined sprinkling ratio of mineral vs. seawater which contains approximately 5,000 cells/mL of C. polykrikoides was 10 g/L. In order to quantify the removal efficiency, the density of living cells was measured by counting with the Intervals of 0, 10, 30, and 60 minutes after sprinkling. Five Hwangtos feom different localities were examined in this study. It is found that a material with a high concentration of Fe and Al was the most effective to remove C. polykrikoides. After the sprinkling of the Hwangto showing the best removal efficiency in the test, 99% of total algaes were found to be eliminated within 60 minutes. Jeokeokji showed the highest removal efficiency among clay mineral medicines(92% removal efficiency after 60 minutes), and the rests in decreasing order are as follows: Gamto (91%) > Baekseokji (89%) > Hydromica (81%). In addition, Fe-oxide mineral medicine similarly looking as fine-grained earthy Daejaseok showed 100% removal efficiencyafter 30 minutes, and Wooyoeryang, 95% after 60 minutes. It is noted that even little addition (1 g/L) of Daejaseok, 10% of Hwangto concentration into seawater showed the removal efficiency of 100% after 60 minutes. From the results, it could be concluded that the fine-grained earthy Daejaseok was the most effective natural mineral medicine to remove the C. polykrikoides from seawater. Under the microscope the removal mechanism was found to be activated in the following order: adsorption, swelling of chain colony, chain colony crisis and algaecide.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.31-39
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• 2002

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water column can accumulate in sediments at much higher levels. The purpose of this study was to make optimal treatment and disposal plan o( sediment for water quality improvement in small-scale resevoir based on an evaluation of degree of contamination. The degree of contamination were investigated for 23 samples of 9 site at different depth of sediment in small-scale J river. Results for analysis of contaminated sediments were observed that copper concentration of 4 samples were higher than the regulation of hazardous waste (3 mg/L) and that of all samples were exceeded soil pollution warning levels for agricultural areas. Lead and mercury concentration of all samples were detected below both regulations. Necessary of sediment dredge was evaluated for organic matter and nutrient through standard levels of Paldang lake and the lower Han river in Korea and Tokyo bay and Yokohama bay in Japan. The degree of contamination for organic matter and nutrient was not serious. Compared standard levels of Japan, America, and Canada for heavy metal, contaminated sediment was concluded as lowest effect level or limit of tolerance level because standard levels of America and Canada was established worst effect of benthic organisms. The optimal treatment method of sediment contained heavy metal was cement-based solidification/stabilization to prevent heavy metal leaching.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.285-292
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• 2013

This study was carried out to validate the safety of ametoctradin residues in agricultural commodities by developing an official analysis method. An analytical method was developed and validated using HPLC-PDA detectors. The samples were extracted with methanol, subsequently partitioned with dichloromethane and purified with florisil column chromatograph using acetone/hexane (30/70, v/v) as solvent. The method was validated by using grape, hulled rice, mandarin, and potato spiked with ametoctradin at 0.05 and 5.0 mg/kg, and pepper at 0.05 and 2.0 mg/kg. Average recoveries were 76-114.8% with relative standard deviation less than 10%, and the limit of detection and limit of quantification were 0.0125 and 0.05 mg/kg, respectively. The result of recoveries and overall coefficient of variation of the laboratory results from Gwangju regional Food and Drug Administration (FDA) and Daejeon regional FDA was accorded with Codex Alimentarius Commission Guideline (CAC/GL 40). Based on these results, this method was found to be appropriate for ametoctradin residue determination and can be used as the official method of analysis.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.35-43
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• 2005

Bioslurping combines the three remedial approaches of bioventing, vacuum-enhanced free-product recovery, and soil vapor extraction. Bioslurping is less effective in tight (low-permeability) soils. The greatest limitation to air permeability is excessive soil moisture. Optimum soil moisture is very soil-specific. Too much moisture can reduce air permeability of the soil and decrease its oxygen transfer capability. Too little moisture will inhibit microbial activity. So Modified Fenton reaction as chemical treatment which can overcome the weakness of Bioslurping was experimented for simultaneous treatment. Although the diesel removal efficiency of SVE process increased in proportion to applied vacuum pressure, SVE process was difficulty to remediation quickly semi- or non-volatile compounds absorbed soil strongly. And SVE process had variation of efficiency with distance from the extraction well and depth a air flow form of hemisphere centering around the well. Below 0.1 % hydrogen peroxide shows the potential of using hydrogen peroxide as oxygen source but the co-oxidation of chemical and biological treatment was impossible because of the low efficiency of Modified Fenton reaction at 0.1 % (wt) hydrogen peroxide. NTA was more efficiency than EDTA as chelating agent and diesel removal efficiency of Modified Fenton reaction increased in proportion to hydrogen peroxide concentration. Hexadecane as typical aliphatic compound was removed less than Toluene as aromatic compound because of its structural stability in Modified Fenton reaction. What minimum 10% hydrogen peroxide concentration has good remediation efficiency of diesel contaminated groundwater may show the potential use of Modified Fenton reaction after bioslurping treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.24
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• pp.5-38
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• 1991

비료(肥料)를 공업적(工業的)으로 제조(製造)하여 농업(農業)에 사용(使用)하기 시작(始作)한 이래(以來) 신비종(新肥種)의 개발(開發)에 대한 관심(關心)은 부단(不斷)히 계속(繼續)되어 왔으며 현재(現在)에도 어느 국가(國家)나 생산업계(生産業界)에서 개발(開發)을 위한 노력(努力)을 많이 기우리고 있음이 현실(現實)일 것이다. 어느 국가(國家)와 어느 시대(時代)에 있어서나 현존(現存) 비종(肥種)을 생산(生産)함에는 소비(消費)와 생산면(生産面)에서 상응(相應)하는 사정(事情)이 있었을 것이며 또한 미래(未來)에도 신비종(新肥種)을 개량(改良)하거나 창제(創製)함에는 여러 가지 관련문제(關聯問題)를 검토(檢討)하여 새로운 요구(要求)에 합리적(合理的)으로 부합(符合)되도록 설계(設計)해야 할 것이다. 비료(肥料)는 현대(現代) 농업(農業)에서 불가피(不可避)하게 사용(使用)되는 기본자재(基本資材)이며 세계적(世界的)으로 그 소비(消費)가 증가(增加)되나 국가별(國家別) 농업(農業)의 특수성(特殊性)에 맞추어서 비료(肥料)의 형태(形態)와 생산량(生産量)에 차이(差異)가 있게 되며 또 변화(變化), 개량(改良)될 것이다. 우리나라의 농업(農業)이 최근(最近) 급속(急速)히 변화(變化)되면서 생산수단(生産手段)과 경영(經營)에도 큰 변혁(變革)이 불가피(不可避)하게 따라야 할 것으로 판단(判斷)된다. 생산수단(生産手段)의 개량(改良)은 농산물(農産物) 생산가(生産價)를 낮추고 노력(勞力)의 투입(投入)을 줄이며 우수품질(優秀品質)의 농산물(農産物)을 안정적(安定的)으로 생산(生産)하기 위한 대응책(對應策)이 될 것이다. 비료(肥料)의 사용(使用)은 이러한 시대적(時代的) 요구(要求)에 맞추어 신비종(新肥種)이 개발(開發)되고 시용기술면(施用技術面)에서 발전(發展)이 있어야 될 것이다. 미래(未來)의 우리 나라 농업(農業)을 위하여 개발(開發)되어야 할 비종(肥種)의 형태(形態)와 그에 관련(關聯)되는 요건(要件)은 다음과 같이 요약(要約)된다. 1. 시비효율(施肥效率)을 높히기 위하여서나 성력재배(省力裁培)를 위하여 완효성(緩效性) 비료(肥料) 특히 질소비료(窒素肥料)의 신비종(新肥種) 개발(開發)이 절실(切實)히 필요(必要)하다고 판단(判斷)됨. 신비종(新肥種)은 대상작물(對象作物)의 종류(種類), 재배방식(裁培方式) 및 기계화(機械化) 상태(狀態)에 적합(適合)한 형태별(形態別)로 제조(製造)됨이 바람직함. 완효성(緩效性) 질소비료(窒素肥料)의 제조(製造)에는 화학합성(化學合成), 성형화(成形化), 흡착화(吸着化) 및 피복화(被覆化) 방식중(方式中) 성형화(成形化)에 의한 것이 최다(最多)이나 피복화(被覆化)도 재료(材料)와 기술(技術)의 발전(發展)에 따라 증가(增加)의 경향(傾向)임. 2. 현존(現存) 복합비료(複合肥料)의 토양(土壤) 및 작물(作物)에 대한 적합성(適合性)을 재검토(再檢討)하여 효율(效率)을 높히도록 개량(改良)함. 3. 소시비방식(少施肥方式)의 영농(營農)으로서 환경(環境)을 오염(汚染)으로부터 방호(防護)할 것이며 4. 작물종류(作物種類)(품종포함(品種包含)) 유전자형별(遺傳子型別) 비료감응성(肥料感應性)을 검정(檢定)하여 소시비(少施肥), 고효율(高效率)을 기(期)하도록함. 5 작물(作物)의 영양생리학(營養生理學) 분야(分野)에서도 비료외적(肥料外的)인 성장관련요인(成長關聯要因)의 작용(作用)을 연구(硏究)하여 응용(應用)의 가능성(可能性)을 추구(追究)함이 미래(未來)의 한 과제(課題)가 될 것으로 생각됨. 예(例): 유전공학적(遺傳工學的) 기법(技法)에 의한 성장인자(成長因子)의 개량(改良) 또는 시비효율(施肥效率)의 증대(增大) 작물성장(作物成長)과 미생물활동(微生物活動)과의 상호관계(相互關係) 등(等). 6. 가용(可用) 자원(資源)의 비료화(肥料化)를 위하여 타산업(他産業)의 부산물(副産物) 및 폐기물(廢棄物) (특히 유기질(有機質) 자원(資源))을 효율적(效率的)으로 재활용(再活用)하도록 함.