• NICE (News & Information for Chemical Engineers)
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• v.31 no.1
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• pp.48-57
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• 2013

석탄가스화 기술은 석탄의 에너지원으로서의 중요성에 더하여 고효율 고청정 에너지화 기술이라는 측면에서 많은 기술선진국에서 시장 선점을 위하여 다양한 석탄가스화 기술을 개발하고 있다. 초기에는 미국과 유럽을 중심으로 기술개발이 이루어졌으나 최근에는 일본과 중국에서도 상업화 기술을 보유하는 수준에 이르렀다. 특히 중국은 우리나라보다 뒤늦게 기술개발을 시작하여 2000년 이전에만 하여도 석탄가스화 기술의 후진국이었으나 최근에는 ECUST와 TPRI 등이 주도적으로 기술개발을 진행하고 집중적인 연구개발 지원에 힘입어 이제 2,000톤/일급 이상의 가스화기 개발을 완료하고 수십기의 상업용 실적을 보유하는 등으로 비약적인 발전을 이루었다. 반면에 우리나라는 중국보다 이른 시점인 1990년대 초반부터 가스화 기술개발을 시작하여 많은 기술축적을 이루어 미분탄 기류 수송, 슬러리 제조, 탈황 기술 등의 일부 요소기술에서는 세계 수준급의 기술을 확보하고 있으나 연구비의 제한적인 투자로 인하여 규모의 측면에서는 아직 수톤~수십톤/일급 가스화기의 운전 또는 설계 진행 수준에 머무르고 있다. 우리나라의 경우 에너지의 대부분을 수입한다는 측면을 고려할 때에 저가의 에너지원 확보 및 에너지원의 다양성 확보 측면에서 석탄에너지 활용은 필수적이므로 석탄 활용 기술, 특히 석탄가스화 기술 개발에 많은 관심을 기울일 필요성이 아주 강하다고 판단된다.

• Food Science and Preservation
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• v.24 no.7
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• pp.885-890
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• 2017

For the construction of the microbial monitoring method, anti-Salmonella polyclonal antibodies (pAbs) were produced from a rabbit and purified by saturated ammonium sulfate precipitation and protein A affinity column. The reactivity of anti-Salmonella pAbs was compared to that of commercial ones by using an indirect ELISA. The specificity of anti-Salmonella pAbs was investigated using 20 Salmonella serotypes and 20 non-Salmonella strains. A capturing ability of anti-Salmonella pAbs was investigated by exposing antibody-immobilized gold biosensor to different concentration of Salmonella mixture. Anti-Salmonella pAbs were successfully produced and purified with an antibody concentration of 2.0 mg/mL The reactivity of purified anti-Salmonella pAbs was greater than that of commercial one at all tested concentrations. All Salmonella serotypes, except S. Diarizonae, showed excellent binding efficiency with purified anti-Salmonella pAbs. Moreover, the purified anti-Salmonella pAbs showed excellent specificity against all non-Salmonella strains. The anti-Salmonella pAbs immobilized on the gold biosensor demonstrated the successful capturing capability against Salmonella with a dose-response manner. Therefore, the anti-Salmonella pAbs exhibited sufficient reactivity, specificity, as well as capturing capability against Salmonella to be considered as a bio-recognition element.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.359-368
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• 2008

Black soybean has been widely utilized as foods and oriental medicinal materials. The pigmentation in the seed coat of black soybean is due to accumulate anthocyanins in the epidermis palisade layer. The anthocyanins of black soybean seed coat are considered as a parameter of quality evaluation of black soybean. Therefore, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of anthocyanins in black soybean seed coats extracts. The efficient HPLC analytical condition of D3G, C3G, and Pt3G contained extracts of black soybean seed coats was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 5% aqueous formic acid, and mobile phase B, comprising 5% formic acid - acetonitrile, and delivered at a flow rate of 0.7 mL/min as follows: $0{\sim}35\;min$, $90%\;A{\sim}60%\;A$; 36 min, 90% A; 46 min, 90% A. The UV-VIS. detection wavelength was set at 520 nm. The limit of detection (LOD) for D3G, C3G, and Pt3G were under 10 ng/mL.

• Journal of Mushroom
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• v.16 no.4
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• pp.299-303
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• 2018

Flammulina velutipes, which is a white rot fungus, is a commercially important edible mushroom and is produced in large quantities with the help of an automated and mechanized cultivation system in Korea. F. velutipes has the lowest distribution rate among domestic cultivars, estimated at about 20 percent. As most white cultivars of F. velutipes produced and exported to Korea were introduced from Japan, farmers pay large amounts of royalties. Therefore, we have developed a new, purely domestic cultivar, "Baeke," to substitute for Japanese cultivars, which has improved storage characteristics for export. Baeke was bred by mating two monokaryotic strains isolated from ASI 4216-18 (Hansol) and ASI 4217-26 (Baekjung). Baeke showed faster mycelial growth and higher mycelial density upon incubation for seven days at $25^{\circ}C$ on PDA media than the control variety. The mycelial growth of Baeke was even maintained at $30^{\circ}C$ unlike the control. The lengths of pilei and stipes in Baeke harvested in the optimal stage were $11.2{\pm}0.5mm$ and $125{\pm}5.4mm$, respectively, and they were $11{\pm}0.5mm$ and $141.9{\pm}5.7mm$, respectively, in the control harvested in the optimal stage. The yields of Baeke ($257.4{\pm}13.5g$) and control ($270.7{\pm}17.8g$) per 1,100ml in bottle cultivation showed no significant difference. Overall, our results showed that Baeke was at par with foreign varieties of Flammulina velutipes in terms of quality and yield and had a uniformly shaped fruitbody, which added to its commercial value.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1998.10a
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• pp.83-106
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• 1998

This study was conducted to investigate the probiotics(acid and bile resistance, fermentation properties, viability, cholesterol assimilation, antimicrobial activity, antimutagenicity, and immunoactivation) of the strains of bifidobacteria isolated from healthy Koreans and to investigate the effects of oral administration of Bifidobacterium longum A-2 on the fecal microflora, ${\beta}-glucuronidase$ activity, pH values, Ammonia concentration. The experimental results are summarized as follows: The probiotics were tested for 23 strains including three commer챠al strains as controls. Compared to other strains, strains of A-2 and A-9 showed more acid resistance whereas A-2, A-5, A-13, A-14, A-18 and A-22 showed excellent bile resistances. The properties of bifidobacteria during fermentation were tested. Strains of A-1, A-2, A-3, A-4, A-6, and A-23 resulted in less than pH 4.5 and titratable acidity over 0.90 after 24 hr of fermentation. When the strains of A-2 was grown with glucose, maltose, and fructooligosaccharide, the acetic acid production were higher than with sorbitol and mannitol. The storage stability of the strains of A-2 and A-22 were tesed, indicating the strain A-2 was more stable over 10 days of storage at both $4^{\circ}C$ and $20^{\circ}C$ than A-22. The strains of A-8, A-10, A-11, A-12 and A-20 assimilated more than 30% of cholesterol included in the media. The strains of A-1 and A-2 showed antimicrobial activity against Sta. aureus. The antimutagenicity of the strains were also tested, showing that the mutation was suppressed more by three strains(A-2, A-12, and A-23). In addition, strain A-5 improved immunological activity(phagocytosis, $TNF-{\alpha}$, IL-6) more than other strains. In the effects of oral administration of Bif. longum A-2, the number of fecal bifidobacteria was siginificantly increased(p<0.01) and the level of fecal ${\beta}-glucuronidase$ also was siginificantly reduced(p<0.05). However there were no siginificant differences in the level of Lαctobacilli, Enterobacteriaceae, Clostridium perfringens, pH and ammonia by the administration. The results suggested that Bif. longum A-2 may be met the criteria for probiotics culture.

• Research in Plant Disease
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• v.26 no.3
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• pp.170-178
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• 2020

Most strawberry viruses exist relatively low titers in tissues, and strawberry tissues include high levels of contamination by polysaccharides and phenolic compounds. These traits make the efficiency of strawberry diagnosis difficult. In this study, we tested different commercially available kits and reagents to secure optimal RNA extraction methods to determine virus detection from strawberry leaves. Total RNA was isolated from leaves of strawberry mottle virus (SMoV)-infected strawberry cultivar 'Mihong'. The efficiency of total RNA for virus diagnosis was confirmed through SMoV detection by one-step or two-step reverse transcription and polymerase chain reaction (RT-PCR). Among those, the RNeasy plant RNA kit was best to isolate RNA and the isolated RNA was good enough for further applications. To ensure a reliable detection for strawberry viruses, synthetic diagnosis clones for major seven strawberry viruses such as strawberry mild yellow edge virus, SMoV, strawberry latent ring spot virus, strawberry crinkle virus, strawberry pallidosis associated virus, strawberry vein banding virus and strawberry necrotic spot virus have been constructed. Based on the synthetic genes in each clone, primer sets for seven strawberry viruses were designed and tested an RT-PCR condition through a simultaneous application of the same annealing temperature that allowed to achieve an efficient and convenient diagnosis.

• Journal of Life Science
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• v.27 no.3
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• pp.301-309
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• 2017

This study is examined river naturality and vegetative composition of river riparian zones to identify their most important sources of variation. Information on plant species cover and on physical characteristics that occur at upper, medium, and low areas was collected for 30 riparian plots located throughout the Youngjeong River in Korea. The riparian areas of river banks are dominated by mixed sediment and the vegetation is composed of herbs, shrub, and trees. The floristic characterization of riparian at this river during 2015 season was identified with a total of 28 families, 72 genera, 75 species, 13 varieties, 23 associations. The vegetations of low water's edge and flood way at upper region were naturally formed various vegetation communities by natural erosion. Forty plant species were identified around the upper region, where the dominant growth form was mostly trees. The flood way vegetation at middle region was both of natural vegetation and artificial vegetation. Land uses in riparian zones river levee at low region were bush or grassland as natural floodplain. The values of cover-abundance at upper, middle, and low region were total 9.26, 7.24, and 7.56, respectively. Grasses and forbs at the Youngjeong River have similar cover-abundance values. Recent, many riparian areas of this river have been lost or degraded for commercial and industrial developments. Thus, monitoring for biological diversity of plant species of this river is necessary for an adaptive management approach and the successful implementation of ecosystem management.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.21-33
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• 2007

The dispersion/flocculation behavior of bentonite is a major concern in performance of drilling fluid. We studied the dispersion/flocculation characteristics of three commercial bentonites [two CMC (carboxymethyl cellulose) treated and one untreated] in waters of different pHs and salt concentrations. We also examined changes in the viscosity of bentonite suspensions in such waters as a major rheological property of drilling fluid. The dispersion/flocculation behaviors of bentonites were measured by two methods: colorimetric and light scattering method. Light scattering method allows estimating the floc diameter and flocculation rate. The dispersion and flocculation behaviors were diverse with the different bentonites and water qualities. In distilled water, all the bentonites were well dispersed up to first 10 minutes. After that, the CMC-bearing bentonites were flocculated. In salt waters, all the samples were flocculated and the flocculation rate is varied with salt concentration and polymer content. The volume of settled flocs decreased with increasing salt concentration. The flocculation rate and floc diameter increased with decreasing pH of solutions, whereas the volume of settled flocs increased with increasing pH of solutions. The bentonites of fast flocculation behavior had low viscosity. The results of the present study will be helpful in applying bentonites to drilling fluids in diverse environments.

• Journal of the Korean Regional Science Association
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• v.38 no.2
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• pp.59-72
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• 2022

In line with increasing interest of climate change and pedestrian rights, the city of Seoul has been implementing car-free pedestrian street policies. The government and the private sector agreed to introduce carfree streets, expecting to increase the urban vibrancy and attract customers in the streets. However, studies that empirically analyze the effects of the policy are insufficient, and there are no studies that reevaluate the car-free pedestrian street policy after the COVID-19 outbreak. Therefore, this study evaluates the car-free pedestrian street policy at the commercial street, the Jongno 52-gil, using the synthetic control method. As a result of the analysis, it was found that the car-free pedestrian street policy was valid for enhancing urban vibrancy. Also, it was found that proper time interval is required to assess the policy since the peak increase of policy was observed in 3 months after the policy implementation. However, less than a year, the increase of the de facto population density on the Jongno 52-gil was revealed to be insignificant. In addition, the Jongno 52-gil was more vulnerable in the decrease of the de facto population density in the COVID-19 period than the synthetic control region. The results of this study suggest that long-term population inflow measures and flexible counterplan to contagious diseases are necessary in the car-free pedestrian street policy.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.434-443
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• 2023

We have investigated the performance improvement of grease by synthesizing calcium sulfonate grease as an alternative to lithium grease, which is widely used globally. Since the composition ratio of the grease, when manufactured, is usually 50% base oil and 50% thickener, using grease as a lubricant in a cryogenic environment is not encouraged due to its inferior low-temperature performance. In this study, we have synthesized three types of calcium sulfonate grease with paraffin oil and PAO-based base oil and thickener. Furthermore, lithium grease was synthesized via saponification with PAO-based base oil, lithium hydroxide, 12-hydroxystearic acid, and sebacic acid. We have measured low-temperature characteristics using a rheometer and low-temperature torque meter, and tribology characteristics were obtained using a four-ball lubricant tester and schwingung reibung verschleiß (SRV). As a result, the flow point of the calcium sulfonate grease synthesized with a PAO-based base oil and thickener was found to be -40℃, overcoming the existing calcium sulfonate grease's low-temperature limitation. Moreover, the synthesized calcium sulfonate grease showed low-temperature performance similar to that of lithium grease synthesized with PAO base oil, but superior anti-wear, extreme pressure, coefficient of friction, heat resistance, adhesion, and corrosion resistance. It is thus expected to commercially replace the existing lithium grease.