• 한국지반공학회논문집
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• 제34권12호
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• pp.83-92
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• 2018

사면 구조물은 시간이 경과함에 따라 대상지반에서 각종 열화 현상이 진행되어 내구성의 저하로 인한 붕괴가 발생할 수 있으며, 사용 연한을 감소시키는 결과를 초래하게 된다. 이러한 지반 열화에 따른 사면안정에 대한 접근방안은 지반의 물리적 특성 및 기하학적인 구조에 국한하여 분석하는 기존의 한계 평형 해석과는 또 다른 개념이라 할 수 있다. 본 연구에서는 사면의 열화 특성과 관련하여 각종 문헌 조사를 통하여 비교분석을 수행하고, 전단강도 저감에 대한 최적의 제안식들로서 지수함수, 로그함수 및 역쌍곡선 함수를 제시하고, 열화에 취약한 양산 단층대의 셰일층에서 붕괴가 발생한 경부고속철도 절토사면을 대상으로 사례분석을 실시하였다. 본 연구에서는 사례분석을 통하여 향후 열화로 인한 사면 안전성과 관련하여 정량적인 평가를 위한 최적의 강도 저하 곡선을 도출하고 한계평형해석에 의한 안정해석을 할 수 있는 접근 방법을 제시하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권6호
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• pp.816-826
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• 2015

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from $10^7$ to $10^{10}cfu/g$ during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to $10^9cfu/g$ DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

• 한국인쇄학회지
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• 제29권3호
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• pp.41-53
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• 2011

For manufacturing the tape for repairing archival documents, we tested ten carrier candidates for selecting best material. The tensile strength, transmissivity, stability of deterioration, and processability were determined. Physical-chemical characteristics and stability of deterioration was best to the Hanji. Tensile strength and transmissivity was best in tracing paper, but was low in oil paper, white sketch paper, lyon coat paper. Synthetic carrier to tensile strength showed higher than paper carrier and to the transmissivity showed 2-8 times higher than paper carriers. The tracing paper to the transmissivity was 10 times higher than others. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $90^{\circ}C$ for 15 days. Oil paper and white sketch paper turned strongly yellowish. Cellulopane, Felt, and Cpp film showed stable stability of deterioration, but deformation like wrinkles. PET film and Syntheletic film showed excellent conservation characteristics without any change of exterior. Test of adhesive uniform between carriers and adhesive processability was performed. PET film > Syntheletic film > Tracing Paper in order were determined. Ununiformal adhesive characteristics appeared to Hangi. Accordingly, we thought that Hanji as carrier material might be unsuitable because of low adhesive processability.

• 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.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.421-424
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• 1996

Effects of humidity absorbing deterioration on AC dielectric breakdown characteristics of modified epoxy resin system with SN(succinonitrile) were investigated. As the forced humidity absorbing deterioration proceeded under high temperature and humidify, glass transition temperature increased. The dielectric breakdown strength increased and then decreased at deterioration cycles higher than 2. Not only, the increment of thermal stability but also, the physical detects such as Internal cracks and voids occurred during the humidity absorbing deterioration cycle were the main causes of the change in dielectric properties.

• 펄프종이기술
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• 제45권6호
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• pp.10-16
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• 2013

This study aims to carry out the final evaluation on the deterioration stability of dewaxing and strengthening treatments devised to conserve and restore the beeswax-treated volumes of the Annals of the Joseon Dynasty. Thus, this study artificially deteriorated dewaxed Hanji, strengthened Hanji and beeswax-treated Hanji with optimized processing conditions applied, and comparatively analyzed the deterioration characteristics of each kind of Hanji. As a result of this study, it turned out that there was the loss of physical strength and the value of $L^*$ was increased and the values of $a^*$ and $b^*$ were decreased from removing beeswax after dewaxing by supercritical fluid extraction (SFE). Also deteriorated strength during dewaxing was reinforced by strengthening treatment with methylcellulose and it showed higher strength than beeswax-treated Hanji. From the evaluation on deterioration stability after dewaxing and strengthening, it turned out that deterioration stability of strengthened Hanji is the superior. Therefore, it is presumed that conservation of aged beeswax-treated Hanji can be improved and extended when dewaxing and strengthening are applied under optimum conditions.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.543-550
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• 2000

Rock slopes along the road or railroad are affected by temperature and therefore experienced iterative freezing-thawing process between winter and early spring. The purpose of this study is to analyze the stability of rock slopes which are influenced by the deterioration due to the freezing-thawing. The analysis is the homogenization method which evaluates the strength property of discontinuous rock mass, and as a strength failure criterion, Drucker-Prager failure criterion is used. The deterioration property of real rock is obtained by a freezing-thawing laboratory test of tuff and this property of deterioration is quantitated and used as a basic data of stability analysis for rock mass. To evaluate the deterioration depth due to the freezing-thawing in situ rock slope, one dimensional heat conductivity equation is used and as the result I can find that the depth of which is affected by a temperature. After the freezing-thawing depth of model slope is determined, we analyze the pattern of rock mass stength value of rock slope model which excesses the limit of self-load.

• Journal of Ginseng Research
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• 제25권2호
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• pp.94-100
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• 2001

The influence of cultivation condition and harvest time on the storage stability of the fresh ginseng (50g) individually packaged in a soft film bag (ONY/LDPE/L-LDPE; 200$\times$300 mm, 90㎛) was investigated. When the fresh ginsengs were divided into four groups of direct-planted ginseng on the paddy soil(PD), transplanted ginseng on the upland(UT) and each group was stored at 25$\^{C}$ for 40 days, the quality deterioration rate was the highest in PD group while PT, UD and UT groups exhibited similar quality patterns from each other. When each group was stored at 10$\^{C}$, the quality deterioration rate was also the highest in PD group and the other three groups exhibited similar quality patterns from each other till 90 days passed after storage. However, the quality deterioration rate of UT group was 54% which was higher than UD group or PT group 180 days after storage. When the fresh ginseng harvested between September of 1997 and October of 1998 was individually packaged with the soft film and stored at 25$\^{C}$ for 12 days, the quality deterioration rate was the lowest in the group harvested in October while relatively high in the groups harvested between July and September.

• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.516-522
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• 2016

We investigated the effects of the predominant lactic acid bacteria (LAB) on the fermentation characteristics and aerobic stability of total mixed ration (TMR) silage containing soybean curd residue (SC-TMR silage). The SC-TMR materials were ensiled in laboratory silos for 14 or 56 days. LAB predominant in SC-TMR silage were identified (Exp. 1). Lactobacillus fermentum (L. fermentum) and Streptococcus bovis (S. bovis) were found in the untreated materials, Leuconostoc pseudomesenteroides (L. pseudomesenteroides) in 14-day silage and Lactobacillus plantarum (L. plantarum) in all silages. Pediococcus acidilactici (P. acidilactici), Lactobacillus paracasei (L. paracasei), and Lactobacillus brevis (L. brevis) formed more than 90% of the isolates in 56- day silage. Italian ryegrass and whole crop maize were inoculated with P. acidilactici and L. brevis isolates and the fermentation and aerobic stability determined (Exp. 2). Inoculation with P. acidilactici and L. brevis alone or combined improved the fermentation products in ryegrass silage and markedly enhanced its aerobic stability. In maize silage, P. acidilactici and L. brevis inoculation caused no changes and suppressed deterioration when combined with increases in acetic acid content. The results indicate that P. acidilactici and L. brevis may produce a synergistic effect to inhibit SC-TMR silage deterioration. Further studies are needed to identify the inhibitory substances, which may be useful for developing potential antifungal agents.