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        검색결과 32

        4.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : It is well known that low temperature cracking is one of the most serious distresses on asphalt pavement, especially for northern U.S. (including Alaska), Canada and the northern part of south Korea. The risk of thermal cracking can be numerically measured by estimating thermal stress of a given asphalt mixture. This thermal stress can be computed by low temperature creep testing. Currently, in-direct tensile (IDT) mixture creep test mentioned in AASHTO specification is used for measuring low temperature creep properties of a given asphalt mixture. However, IDT requires the use of expensive testing equipment for performing the sophisticated analysis process, however, very few laboratories utilize this equipment. In this paper, a new and simple performance test (SPT) method: bending beam rheometer (BBR) mixture creep testing equipment is introduced, and the estimated experimental results were compared with those of conventional IDT tests. METHODS: Three different asphalt mixtures containing reclaimed asphalt pavement (RAP) and roofing shingles were prepared in the Korea Expressway Corporation (KEC) research laboratory. Using the BBR and IDT, the low temperature creep stiffness data were measured and subsequently computed. Using a simple power-law function, the creep stiffness data were converted into relaxation modulus, and subsequently compared. Finally, thermal stress results were computed from relaxation modulus master curve using Gaussian quadrature approach with condierations of 24 Gauss number. RESULTS: In the case of the conventional asphalt mixture, similar trends were observed when the relaxation modulus and thermal stress results were compared. In the case of RAP and Shingle added mixtures, relatively different computation results were obtained. It can be estimated that different experimental surroundings and specimen sizes affected the results. CONCLUSIONS: It can be said that the BBR mixture creep test can be a more viable approach for measuring low temperature properties of asphalt mixture compared to expensive and complex IDT testing methods. However, more extensive research and analysis are required to further verify the feasibility of the BBR mixture creep test.
        4,000원
        7.
        2018.07 구독 인증기관·개인회원 무료
        This paper investigates a theoretical and experimental evidence for a niche strategy for small and medium online shopping malls to survive against large famous shopping malls dominating the E-commerce market. The present study explored both theoretically and empirically how consumers’ preferences for alternatives in online shopping context are affected by their construal level and concentrated its efforts on the verification of the phenomenon under various frames and regarding various categories(Liberman and Trope 1998; Liberman, Trope, and Stephan 2007, Liberman Trope, and Wakslak 2007). For this, this study demonstrates how chronic construal levels of consumers may affect their alternative choice for online shopping via various contexts (Experiment 1-3) and categories (Experiment 3-5). This series of experiments suggests that consumers with high construal level can be defined as a group that is relatively less susceptible to reputation of the shopping malls. Thus, strategically targeting this group of consumers will help small online malls lacking store reputation to mitigate their competitive disadvantage. Based on both existing literature and the experimental results as above, this research discusses possible methods for small online shopping malls to target high-construal segmentation.
        11.
        2016.07 구독 인증기관·개인회원 무료
        The purpose of this study is to present theoretical and experimental evidence for a niche strategy for small and medium online shopping malls to run business against large famous shopping malls prevailing the E-commerce market. For this, the present study demonstrates how chronic construal levels of consumers may affect their alternative choice for online shopping via various contexts (Experiment 1-3) and categories (Experiment 3-5). This series of experiments suggests that consumers with high construal level can be defined as a group that is relatively less susceptible to reputation of the shopping malls. Thus, strategically targeting this group of consumers will help small and medium-sized online malls lacking store reputation to mitigate their competitive disadvantage. Based on both existing literature and the experimental results as above, this research discusses possible methods for small and medium-sized online shopping malls to target high-construal segmentation.
        13.
        2006.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        중수로 원전내 여러 계통으로 부터 발생된 폐수지내에는 핵종이 다량 함유되어 있으며, Class A 및 C 폐기물로 분류되는 폐수지의 적정 처리 기술 개발을 위한 기초연구를 수행하였다. IRN-150 혼상 이온교환수지를 이용하여 비방사성 이온과 양이온의 흡착 특성 및 탈차용액을 이용한 이온의 제거 특성을 고찰하였다. IRN-150 수지의 이온의 흡착능은 이론값에 근접한 11 mg-C/g-IRN-150을 나타내었고, 양이온의 흡착 친화도를 단일성분 및 복합성분 시스템을 이용하여 분석하였다. 여러 가지 탈착용액을 이용한 폐수지로부터 이온의 제거 특성을 평가한 결과, 핵종을 전량 효과적으로 제거하기 위해서는 보다도 용액이 유리한 것으로 나타났다.
        4,300원
        14.
        2006.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        [ ] 핵종이 함유된 IRN-150 혼상 폐수지로부터 이온의 제거 및 제거된 핵종의 기체로의 전환 특성을 고찰하였다. 비방사성 이온이 흡착되어 있는 IRN-150 혼합수지로부터 이온의 탈착용액내로의 분리 및 기체로의 전환 특성을 용액의 농도 변화에 따라 평가하였으며, 탈착용액으로는 를 사용하였고, 비교 평가를 위하여 NaOH, , HCl를 이용한 기체로의 전환 특성을 분석하였다. 아울러 월성 원자력발전소에 저장중인 실제 폐수지를 이용하여 탈착용액을 이용한 폐수지내 핵종의 기체화 특성을 평가하였고, 탈착후 잔류용액내 존재하는 감마핵종을 분석하였다.
        4,000원
        15.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        Hemp (Cannabis sativa L.) is a dioecious plant, although monoecious plants are bred in some cultivars for fiber or seed production. Recently, hemp has received attention for medicinal use with some cannabinoids, including cannabidiol. Self-fertilization for breeding inbred lines is difficult because of dioeciousness and anemophily in hemp. This experiment was conducted to develop a self-fertilization method by forming female flowers and seeds from male plants of dioecious hemp. To induce the formation of female flowers on male plants, 500 ㎎ L-1 of ethephon was sprayed on plants at soon, seven and fourteen days after primordia formation. The plant ratio of female flowers formation and the number of harvested seeds were increased by ethephon treatment. Female flowers of male plants have 5 stigmas in contrast to the dual stigma of female 1plants. Male plant seeds were lighter and smaller than those from female plants. Although the germination rate was lower than that of normal seeds from female plants, the seeds from male plants germinated to grow seedlings. Thus, we suggest that hemp plants should be treated with ethephon at soon after primordia formation to induce the formation of more female flowers on the male plants.
        16.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Background: Adenophora triphylla var. japonica (Regel) H. Hara shows vegetative growth with radical leaves during the first year and shows reproductive growth with cauline leaves and bolting during the second year. In addition, the shape of the plant varies within the same species. For this reason, there are limitations to classifying the species by visual examination. However, there is not sufficient genetic information or molecular tools to analyze the genetic diversity of the plant. Methods and Results: Approximately 34.59 Gbp of raw data containing 342,487,502 reads was obtained from next generation sequencing (NGS) and these reads were assembled into 357,211 scaffolds. A total of 84,106 simple sequence repeat (SSR) regions were identified and 14,133 primer sets were designed. From the designed primer sets, 95 were randomly selected and were applied to the genomic DNA which was extracted from five plants and pooled. Thirty-nine primer sets showing more than two bands were finally selected as SSR markers, and were used for the genetic relationship analysis. Conclusions: The 39 novel SSR markers developed in this study could be used for the genetic diversity analysis, variety identification, new variety development and molecular breeding of A. triphylla.
        19.
        2017.05 서비스 종료(열람 제한)
        Background : This study aimed to determine the use of proper organic fertilizer through side dressing application in the environmental cultivation of Adenophora triphylla var. japonica Hara. to improve farming income. Methods and Results : In the cultivation of eco-friendly and environmental medicinal plant like Adenophora triphylla var. japonica Hara., it is necessary to use organic instead of chemical fertilizer. Organic fertilizers such as HL, CK, OK were applied three (3) times during the last ten days of July, August, and September. There was no significant difference between CF and NT, in terms of the number of rooting per 1㎡ which was 12.1 -12.9. There were also no significant differences in plant length, leaf length, leaf width and dry weight. The root length was 19.9 ㎝, which was the longest in CK, and 16.8 ㎝, the shortest in ST, but described as no significant difference. The root width was 14.8 – 5.5 ㎜, and the number of rootlet was 5.7 - 7.1, but was considered not a significant difference. The dry weight was 16.6 g in HL, 16.3 g in CK and ST, and 15.6 g in OK, but still there were no significant differences observed. However, it was 14.6 g in NT, which was considered the lowest, thus there was a significant difference. The number of dry root per 10 a was 149 ㎏ which is considered the most in HL, 141 ㎏ in CK, 140 ㎏ in ST, and 138kg in OK yet there were no significant differences observed. While NT only had 123 ㎏ hence, there was a significant difference on the number of dry root per 10a as compared with the group applied with the three organic fertilizers. Conclusion : In conclusion, it is proper to use Organic Fertilizer HL and CK through side dressing application in growing Adenophora triphylla var. japonica Hara.
        20.
        2017.05 서비스 종료(열람 제한)
        Background : This project was conducted to determine proper seed harvest time and seed storage methods of Adenophora triphylla var. japonica Hara. Methods and Results : When Adenophora triphylla var. japonica Hara. transplanted this year, seeding can only be done the following year. Therefore, the seeds harvested in the interval of ten (10) days were investigated for seed harvest amount, germination rate, seed storage temperature and storing on container, between the period late August and mid-October. It is when the seed fructification started and ended. The seeds harvested from the first ten (10) days of October to mid October were 87.9% in whole seeds. The proper seed harvesting time was mid October which has a germination rate of 75% in whole seed harvest time. The lowest germination rate of 27.3% was at the germination temperature of 15℃. As the temperature rises, the germination rate increases. In 29℃, the germination rate was at 79% which is the highest; and from 30℃, the germination rate decreased to 71%. When the storage temperature was at 0℃ after storage of 5 months, the germination rate was at 83%. However, after storage of 12 months, it decreased by 7% that was 76%. When in 4℃, after storage of 5 months the germination rate was at 85%. However, after storage of 12 months it decreased by 8% which was 77%. In room temperature after storage of 5 months, germination rate was at 77%, but after storage of 12 months it decreased by 22% which was 55%. When seeds were stored in vinyl container, it was observed that the germination rate was at 86% after 5 months of storage, which was 9% higher than seed stored in paper which was 77%. After 12 months storage, seed in vinyl container had a germination rate of 71%, which was 3% higher than seed in paper at 68%. Conclusion : It is concluded that the proper time of seed gathering of Adenophora triphylla var. japonica Hara. is during the first ten (10) days of October to mid-October. When the long time storage is needed, below zero temperature with vinyl container is more appropriate.
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