• International Journal of Automotive Technology
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• 제7권5호
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• pp.527-534
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• 2006

Modern passenger cars with diesel engines are equipped with DOC(diesel oxidation catalyst) for the purpose of reducing HC and CO in the exhaust stream. Cold start exhaust emissions pose troubles here as on gasoline engine vehicles. As a result, some of the diesel passenger cars roll off todays the assembly lines with WCC(warm-up catalytic converter). Oxidation characteristics of the particulates in WCC is analyzed in this study by EEPS(engine exhaust particulate size spectrometer). The maximum number of PM is found to come out of WCC in sizes near 10nm when an HSDI diesel engine is operated under the conditions of high speed and medium to heavy load. When the temperature of the WCC exceeds $300^{\circ}C$, the number of PM smaller than 30 nm in diameter sharply increases upon passing through the WCC. Total mass of emitted PM gets reduced downstream of the WCC under low speed and light load conditions due to adsorption of PM onto the catalyst. Under conditions of high speed and medium to heavy load, the relatively large PM shrink or break into fine particles during oxidation process within the WCC, which results in more mass fraction of fine particles downstream of the WCC.

• 한국정보컨버전스학회논문지
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• 제7권1호
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• pp.17-24
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• 2014

본 연구는 세계적 수준의 전문대학(WCC) 교수학습센터의 웹서비스 현황을 분석하였다. WCC란 산업체의 요구를 수용할 수 있는 교육여건을 갖추고 성장가능성과 비전을 갖춘 전문대학을 말한다. WCC의 교수학습센터에서 지원하는 웹서비스는 센터소개, 교수지원, 학습지원, 서비스, 특화된 메뉴로 구성되어 있다. 총 21개 대학 중 웹서비스를 제공하고 있는 9대 대학의 메뉴와 대학별 특화된 웹서비스를 분석하였다. 세계적 수준의 전문대학 교수학습센터의 웹서비스를 분석함으로써 전문대학 교수학습센터가 지향하는 교수학습센터 웹서비스의 방향을 제시하고자 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권1호
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• pp.62-72
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• 2016

This study investigated the dynamics associated with prolonged ensiling and aerobic deterioration of whole crop corn (WCC) silages and total mixed ration (TMR) silages containing WCC (C-TMR silages) to clarify the differences that account for the enhanced aerobic stability of TMR silages. Laboratory-scale barrel silos were randomly opened after 7, 14, 28, and 56 d of ensiling and were subjected to analyses of fermentation quality, microbial and temperature dynamics during aerobic exposure. WCC and C-TMR silages were both well preserved and microorganisms were inhibited with prolonged ensiling, including lactic acid bacteria. Yeast were inhibited to below the detection limit of 500 cfu/g fresh matter within 28 d of ensiling. Aerobic stability of both silages was enhanced with prolonged ensiling, whereas C-TMR silages were more aerobically stable than WCC silages for the same ensiling period. Besides the high moisture content, the weak aerobic stability of WCC silage is likely attributable to the higher lactic acid content and yeast count, which result from the high water-soluble carbohydrates content in WCC. After silo opening, yeast were the first to propagate and the increase in yeast levels is greater than that of other microorganisms in silages before deterioration. Besides, increased levels of aerobic bacteria were also detected before heating of WCC silages. The temperature dynamics also indicated that yeast are closely associated with the onset of the aerobic deterioration of C-TMR silage, whereas for WCC silages, besides yeast, aerobic bacteria also function in the aerobic deterioration. Therefore, the inclusion of WCC might contribute to the survival of yeast during ensiling but not influence the role of yeast in deterioration of C-TMR silages.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.29-36
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• 2008

Diesel vehicle is growing in importance in light-duty sector as a way of reducing greenhouse gases due to improved fuel economy. Carbon monoxide, gas-phase hydrocarbon and organic fraction of diesel particulates can be oxidized to harmless products using a diesel warm-up catalyst (WCC). This study investigated the effect of a turbocharger and a baffle on flow fields and temperature distributions in the WCC for Diesel vehicles by a numerical analysis. In the case of the WCC with the turbocharger, velocity vectors and temperatures of inlet of the WCC have the relatively homogeneous distributions by the swirl generated from the turbocharger. Velocity vectors and temperatures of inlet of the WCC with the turbocharger and the baffle have the improved distributions in homogeneity compared with the case of the WCC without the baffle. The homogeneous flow field and the temperature distribution in the WCC may contribute to improve the conversion performance of the catalysts.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.198-207
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• 2018

Objective: This study investigated the association of yeast species with improved aerobic stability of total mixed ration (TMR) silages with prolonged ensiling, and clarified the characteristics of yeast species and their role during aerobic deterioration. Methods: Whole crop corn (WCC) silages and TMR silages formulated with WCC were ensiled for 7, 14, 28, and 56 d and used for an aerobic stability test. Predominant yeast species were isolated from different periods and identified by sequencing analyses of the 26S rRNA gene D1/D2 domain. Characteristics (assimilation and tolerance) of the yeast species and their role during aerobic deterioration were investigated. Results: In addition to species of Candida glabrata and Pichia kudriavzevii (P. kudriavzevii) previously isolated in WCC and TMR, Pichia manshurica (P. manshurica), Candida ethanolica (C. ethanolica), and Zygosaccharomyces bailii (Z. bailii) isolated at great frequency during deterioration, were capable of assimilating lactic or acetic acid and tolerant to acetic acid and might function more in deteriorating TMR silages at early fermentation (7 d and 14 d). With ensiling prolonged to 28 d, silages became more (p<0.01) stable when exposed to air, coinciding with the inhibition of yeast to below the detection limit. Species of P. manshurica that were predominant in deteriorating WCC silages were not detectable in TMR silages. In addition, the predominant yeast species of Z. bailii in deteriorating TMR silages at later fermentation (28 d and 56 d) were not observed in both WCC and WCC silages. Conclusion: The inhibition of yeasts, particularly P. kudriavzevii, probably account for the improved aerobic stability of TMR silages at later fermentation. Fewer species seemed to be involved in aerobic deterioration of silages at later fermentation and Z. bailii was most likely to initiate the aerobic deterioration of TMR silages at later fermentation. The use of WCC in TMR might not influence the predominant yeast species during aerobic deterioration of TMR silages.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.80-86
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• 2005

In this study, we investigated the characteristics of the conversion efficiency and the effect of ageing Diesel Oxidation Catalyst (DOC). The DOC was composed of Warm-up Catalytic Converter (WCC) and Underbody Catalytic Converter (UCC). As the result, the conversion efficiency of THC was 10$\~$50$\%$ on WCC and 30$\~$40$\%$ on UCC .The conversion efficiency of CO was 80$\~$90$\%$ on WCC and remained 10$\~$20$\%$ of CO was purified on UCC. The WCC shows high conversion efficiency on CO. After 20 hours aging process of engine bench, conversion efficiencies of THC and CO were improved a little, because it was activated catalyst surface by 20 hours aging. In case of 80 hours aging, the conversion efficiencies of THC and CO were decreased on WCC. However, the UCC was not affected by aging process .

• 지질공학
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• 제25권1호
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• pp.35-43
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• 2015

수위-유량 관계곡선을 이용한 동절기 수막재배기간의 지하수 사용량 추정 방법을 제시하고, 이를 논산 왕전리 수막재배 지역에 현장 적용하였다. 연구지역의 동절기 수막재배 기간의 농수로수의 구성성분은 주로 지하수와 강우의 직접 유출 성분으로 구성된다. 농수로 수위를 관측하고, 강우에 의한 농수로 수위 상승분을 수위 관측 자료로 부터 제거시키기 위해 기저유출분리법을 적용하였다. 강우에 의한 수위 상승분이 제거된 농수로 수위자료에 수위-유랑 관계를 적용하여 연구지역의 수막재배용 지하수 배출량을 산출하였다. 왕전리 지역의 수막재배용 지하수 사용량은 평균 10,900 m³/d, 420 m³/d/ha인 것으로 추정되었다. 추정 지하수 사용량(420 m³/d/ha)과 전국의 수막재배면적(10,746 ha), 그리고 연간 수막재 배일수(120 days/year)을 기준한 전국 규모의 수막재배용 지하수 사용량은 5억 4천만 m³에 이른다. 이는 농업용 지하수 연간 사용량(약 17 억 m³)의 약 32%에 달한다.

• 동의신경정신과학회지
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• 제21권4호
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• pp.99-112
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• 2010

Objectives : This study was to investigate the associations of Parent Stress Index(PS]). Way of Coping Checklist(WCC). and Diagnostic System of Oriental Medicine(DSOM) in mothers of elementary school children. Methods: In the study. K-PSI-SF. WCC. and DSOM were carried out on 202 mothers of O Oelementary school children during June. 2010. Cross tabulation analysis was used to verify the association of PSI. WCC and DSOM. Results: 1. The most common pathogenic factor was Dampness(濕) in total subjects. 2. The score of problem-focused coping methods showed significant difference in PSI grades. 3. The zp and sc10 of Qi deficiency(氣虛), Blood deficiency(血虛), Qi-Stagnation(氣滯), Insufficiency of Yang(陽虛), Heat(熱), Dampness(濕), Dryness(燥), Liver(肝), Heart(心), and Kidney(腎) showed significant difference in PSI grades. 4. The score of total PSI and PSI subscale had negative correlations with problem-focused coping methods 5. The score of total PSI had positive correlations with Qi-Stagnation (氣滯), Dampness(濕), Dryness(燥), Heart(心), and Kidney(腎) in total subjects. Conclusions : This study provides insights on associations of parenting stress coping methods and diagnostic system in Oriental Medicine. Furthermore, the study shows positive correlations among Qi-Stagnation (氣滯), Dampness(濕), Dryness(燥), Heart(心), Kidney(腎) and PSI, and negative correlations between PSI and Problem-focused coping methods, all with statistical significance.

• 한국초지조사료학회지
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• 제43권1호
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• pp.11-21
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• 2023

본 연구는 기계학습을 기반으로 제작한 수량예측모델을 이용하여 PCR 4.5 시나리오에 따른 사일리지용 옥수수(WCC)의 피해량 산정 및 전자지도를 작성할 목적으로 수행하였다. WCC 데이터는 수입적응성 시험보고서(n=1,219), 국립축산과학원 시험연구보고서(n=1,294), 한국축산학회지(n=8), 한국초지조사료학회지(n=707) 및 학위논문(n=4)에서 총 3,232점을 수집하였으며, 기상데이터는 기상청의 기상자료개방포털에서 수집하였다. 본 연구에서 이상기상에 따른 WCC의 피해량은 RCP 4.5 시나리오에 따른 월평균기온 및 강수량을 시간단위로 환산하여 준용하여 산정하였다. 정상기상에서 DMY 예측값은 13,845~19,347 kg/ha 범위로 나타났다. 이상기상에 따른 피해량은 이상기온 2050 및 2100년 각각 -263~360 및-1,023~92 kg/ha, 이상강수량 2050 및 2100년 각각 -17~-2 및-12~2 kg/ha였다. 월평균기온이 증가함에 따라서 WCC의 DMY는 증가하는 경향으로 나타났다. RCP 4.5 시나리오를 통해 산정한 WCC의 피해량은 QGIS를 이용하여 전자지도로 제시하였다. 본 연구는 온실가스 저감이 진행된 시나리오를 이용했지만, 추가 연구는 온실가스 저감이 되지 않은 RCP 시나리오를 이용한 연구를 수행할 필요가 있다.

• Journal of the Korean Wood Science and Technology
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• 제8권1호
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• pp.1-12
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• 1980

경화촉진제로서 염화칼슘, 경화억제제로서 수크로오즈를 처리한 포트렌트시멘트의 양생효과를 전자현미경에 의해 관찰한 결과, 경화억제제를 처리한 시멘트는 결정을 이루지 못하고 융기상태로 남아있고, 경화촉진제를 처리한 시멘트는 겔형으로 변한후 육각형의 결정을 이루는 것이 관찰되었다. 또한 시멘트-목재 복합체의 양생은 좀 다른 양상을 보이고있어 경화제가 처리된 WCC는 포플러 스리버 표면에서 작은 융기가 겔상의 표면에 많이 관찰되나 무처리는 거의 일정한 모양의 입자가 관찰되어 시멘트 경화촉진제와 억제제의 효과를 구명하였다.