• 대한기계학회논문집B
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• 제27권7호
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• pp.893-900
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• 2003

Numerical simulations of freely propagating flames burning stoichiometric C $H_4$/CHC1$_3$/ $O_2$/$N_2$ mixtures are performed at atmospheric pressure in order to understand the effect of the $O_2$ enrichment level and the CHC1$_3$/C $H_4$ molar ratio. A chemical kinetic mechanism is developed, which involves 69 gas-phase species and 379 forward and 364 backward reactions. The calculated flame speeds are compared with the experiments for the flames established at several CHC1$_3$/C $H_4$ molar ratio (R<1), the results of which is in excellent agreement. As a results of the increased $O_2$ enrichment level from 0.21 to 1, the flame speed and the temperature in the burned gas are increased. At high CHC1$_3$/C $H_4$ molar ratio two peak values appear on the $O_2$ consumption rate, which are affected by CC1$_2$＋ $O_2$$_{-}$>C1O+CC1O and H＋ $O_2$$_{-}$>O＋OH.＋OH.

• 대한수의학회지
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• 제31권3호
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• pp.271-277
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• 1991

To investigate the epidemiological trait of listeriosis, Listeria spp were isolated from poultry meat, products and environmental specimens in chicken slaughterhouse. Also determined were isolation rates by the different enrichment procedures, the biochemical properties of isolates. In a total of 307 samples including poultry meat, liver, feathers, feces, chiller water, scalding water overflow and slaughterhouse floor, Listeria spp were isolated predominantly from scalding water overflow (90.0%), body skin before washing (66.7%), liver (20.0%) and feathers(15.0%) However, few Listeria spp were isolated from body skin after washing and feces. The higher isolation rates were obtained in the secondary enrichment procedure (7.2%) than in the primary enrichment (3.9%); after stored the secondary enrichment cultures for 2 weeks at $4^{\circ}C$, Listeria spp were present in 9.8%. The majority of the isolated Listeria spp were identical to those of the standards strains in biochemical and cultural properties. Overall, Listeria spp were present in 13.4% of the specimens tested, and were in order of prevalence of L innocua(11.1%), L monocytogenes(3.3%), L grayi(0.7%) and L murrayi(0.3%).

• 대한수의학회지
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• 제45권2호
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• pp.169-177
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• 2005

We developed the one-step strip based on an immunochromatographic (IC) assay for the rapid detection of Listeria spp. Genus-specific monoclonal antibody to flagella of L. monocytogenes was conjugated with 40 nm colloidal gold particles which were prepared in our laboratory. The specificity of the IC strip was tested with pure cultured bacteria. All strains of the genus of Listeria spp. yielded positive reactions and 12 strains of non-Listeria were negative, resulting in a specificity of 100%. L. monocytogenes was artificially inoculated in raw pork macerated with listeria enrichment broth. And then it was 10-fold diluted from $8.7{\times}10^6$ to 8.7 CFU/ml. L. monocytogenes could be detected at a minimum of $8.7{\times}10^5CFU/ml$ before enrichment, $8.7{\times}10^2CFU/ml$ after primary enrichment and 8.7 CFU/ml after secondary enrichment, respectively. These results indicated that the IC strip exhibited high specificity and sensitivity in the detection of Listeria spp.

• 약학회지
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• 제52권5호
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• pp.407-411
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• 2008

Phosphorylation plays the most important role in cell signaling mechanism. Various methods to identify the phosphorylation sites of proteins using tandem mass spectrometry (MS/MS) have been reported recently. Furthermore, the enrichment strategy such as Titanium dioxide ($TiO_2$) method should be combined with MS/MS analysis to effectively identify phosphorylation sites. It is necessary to optimize phosphopeptide-enrichment strategy, $TiO_2$ method in this study, due to the low amount of phosphorylated form followed by analyzing them by MS/MS. To evaluate the several conditions to enrich phosphopeptides using $TiO_2$ method, we used ${\apha}$-casein as a standard phosphoprotein and analyzed a representative phosphopeptide (VPQLEIVPNpSAEER) peak of MS spectrum. Batch is better than column method for binding and 300 g/l DHB in loading buffer is better than lower concentration of DHB. 3% TFA and pH 10.5 shows high efficiency of phosphopeptide-enrichment for washing and elution steps, respectively. Finally we identified various efficient conditions of phosphopeptide-enrichment method using $TiO_2$. This optimized method would assist in reliable identifying thousands of phosphorylation sites existed in low abundance from various complex proteins.

• 한국초등과학교육학회지:초등과학교육
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• 제24권4호
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• pp.465-475
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• 2005

In this study, to explore the ways of the development of the effective and desirable teaching and learning materials for the elementary science gifted, relevant previous research results were critically examined and integrated. Then a theoretical background was established and specific materials in Life Areas of elementary science was developed based on the science knowledge construction types of 'What', 'How', and 'Why'. The results could be summarized as follows: (1) The types of educational programs for the science gifted were categorized and defined as 'General-Level','Early-Growing, Fast-Growing General Level', and 'Slow-Growing Enrichment, Excellence 'Types. (2) For 5th graders, in the unit of 'Environment and living Organisms', some activities of Enrichment Type for subject on 'Changes of Living Organism with Temperature' were developed following the processes of RDPE (Research-Development-Practice-Evaluation) and their ways of using and assessment were presented. On the basis of these results, several educational implications were discussed for further research and ways of applying to the science gifted education.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.351-359
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• 2016

The Korean Prototype Gen-IV sodium-cooled fast reactor (PGSFR) is supposed to be loaded with a relatively-costly low-enriched U fuel, while its envisaged transuranic fuels are not available for transmutation. In this work, the U-enrichment reduction by improving the neutron economy is pursued to save the fuel cost. To improve the neutron economy of the core, a new reflector material, PbO, has been introduced to replace the conventional HT9 reflector in the current PGSFR core. Two types of PbO reflectors are considered: one is the conventional pin-type and the other one is an inverted configuration. The inverted PbO reflector design is intended to maximize the PbO volume fraction in the reflector assembly. In addition, the core radial configuration is also modified to maximize the performance of the PbO reflector. For the baseline PGSFR core with several reflector options, the U enrichment requirement has been analyzed and the fuel depletion analysis is performed to derive the equilibrium cycle parameters. The linear reactivity model is used to determine the equilibrium cycle performances of the core. Impacts of the new PbO reflectors are characterized in terms of the cycle length, neutron leakage, radial power distribution, and operational fuel cost.

• 한국환경과학회지
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• 제21권8호
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• pp.989-996
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• 2012

Nitrate contamination of water environments can create serious problems such as eutrophication of rivers. Conventional biological processes for nitrate removal by heterotrophic denitrification often need additional organic substrates as carbon sources and electron donors. We tried to accelerate biological denitrification by using bioelectrochemical reactor (BER) in which electrode works as an electron donor. Denitrification activity of 8 environmental samples from various sediments, soils, groundwaters, and sludges were tested to establish an efficient enrichment culture for BER. The established enrichment culture from a soil sample showed stable denitrification activity without any nitrite accumulation. Microbial community analysis by using PCR-DGGE method revealed that dominant denitrifiers in the enrichment culture were Pantoea sp., Cronobacter sakazakii, and Castellaniella defragrans. Denitrification rate ($0.08kg/m^3{\cdot}day$) of the enrichment culture in BER with electrode poised at -0.5 V (vs Ag/AgCl) was higher than that ($2.1{\times}10^{-2}kg/m^3{\cdot}day$) of BER without any poised potential. This results suggested that biological denitrification would be improved by supplying potential throughout electrode in BER. Further research using BER without any organic substrate addition is needed to apply this system for bioremediation of water and wastewater contaminated by nitrate.

• 한국산림과학회지
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• 제97권5호
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• pp.540-546
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• 2008

Enrichment planting has been used as one of the promising restoration techniques to accelerate the natural restoration process of secondary forests or logged-over forests in Myanmar, The objectives of this study were to examine the growth performances of two commercial species such as Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) in response to different canopy opening treatments and to examine the suitability of these species in enrichment planting activities for the restoration of degraded tropical forests in Myanmar. In this study, split plot design was applied, and three levels of canopy openings were experimented. The survival rate and height growth of two species were measured four times with 6 month interval. The root collar diameter (RCD) was also measured in the last assessment. Although the survival rate of seedlings was not significantly different among the three treatments (p>0.05) as well as between two species (p>0.05) for all consecutive measurements, height (p<0.05) and RCD were significantly different (p<0.001) among the treatments, T. grandis seedlings thrived best under complete canopy opening (i.e., 5 m width canopy opening with strip-clear cutting) while P. macrocarpus seedlings under partial canopy opening (without felling of marketable tree species). Because this study is concerned with only for young stage of seedlings, continuous assessment and follow-up tending activities are needed to verify the species suitability and optimum width of canopy opening for enrichment planting activities in restoration of degraded forests of Myanmar.

• 대한수의학회지
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• 제42권3호
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• pp.327-333
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• 2002

The study was carried out to examine the distribution and survival rate of Listeria monocytogenes (L monocytogenes) from various source of waters using improved isolation method. In comparision of enrichment media for isolation of L monocytogenes from water, the isolation rate and 50% detection limit of the pathogen were higher in UVM modified Listeria enrichment broth (UVM) than Listeria enrichment broth (LEB). On the other hand, when compared the selective media for isolation of the pathogen from water, the isolation rate was highest in culture at Oxford agar followed by Fraser agar, and LEB agar. In order to improve enrichment method, 100 ml of water samples with 0.1 CFU/ml of L monocytogenes was inoculated into 10 ml of UVM concentrated at 10-fold, and incubated for 24 h at $36^{\circ}C$. Isolated frequency of the pathogens in improved enrichment method completely corresponded with common (filter) method. Of a total mumber of 147 water samples from river, lake and sea, the pathogen was isolated from 1 of 39 (2.6%) river water samples and 1 of 75 (1.3%) sea water samples, but no pathogen was isolated from 33 lake water samples. Serotypes of 2 isolates were identified as type 1. L monocytogenes decreased in number from 7.2-7.4 to 4.2-4.7 log CFU/ml for 1 week poststorage (5 and $20^{\circ}C$), but the pathogens were able to be detected in river and sea water until 8 weeks after storage. However, in tap water, L monocytogenes were decreased to undetectable level after 2 weeks of storage.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.326-333
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• 2020

본 연구는 맞벌이 부부의 결혼만족에 대한 이해를 위해 부부 각각의 성역할 태도, 다중역할 수행에서의 갈등과 향상의 경험이 자신과 배우자에게 미치는 상호영향을 살펴보았다. 이를 위해 맞벌이 부부 95쌍, 총 190명을 대상으로 하여 대응표본 t검증과 중다회귀분석을 실시하였다. 먼저 맞벌이 부부의 성역할태도, 다중역할 경험 및 결혼만족도에 있어 부부 간 차이를 살펴본 결과, 성역할태도 및 다중역할 경험에 있어 부부 간의 유의한 차이는 없었으며, 결혼만족도에 있어 남편이 아내보다 유의하게 만족하는 것으로 나타났다. 둘째, 맞벌이 부부의 결혼만족도에 영향을 미치는 요인에 대한 상호영향을 살펴본 결과, 부부 간의 결혼만족도에 영향을 주는 변인에서 유의한 차이가 발견되었다. 남편의 경우 자신의 성역할태도, 자신의 다중역할 향상이 결혼생활의 만족도에 정적으로 유의한 영향을 주는 반면, 아내의 경우는 남편의 성역할태도가 결혼생활 만족에 있어 정적으로 영향을 미치며 아내 자신의 다중역할 갈등이 결혼생활의 만족도에 부적인 영향을 미치는 것으로 나타났다. 이는 맞벌이 부부의 결혼만족에 관한 교육 및 프로그램에 있어 남편과 아내 각각의 영향과 상호간의 영향에 대한 고려가 필요함을 시사한다.