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        검색결과 62

        7.
        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
        8.
        2019.04 구독 인증기관·개인회원 무료
        This study was conducted aiming to figure out two things. First, knowledge of the change in spatial distribution of Tetranychus urticae depending on how to control it (using pesticide or natural enemy). Second, spatial association of T. urticae and Phytoseiulus persimilis in biocontrol plot (B.P). The data was analyzed by spatial analysis by distance indices (SADIE) using global aggregation index, Ia . Ia values were 0.77-1.37 in conventional plot (C.P) and 0.88-1.68 in B.P, respectively. However, the fluctuation level of Ia in B.P was higher than C.P. Therefore, the results indicated that there was a clear spatial pattern change in B.P, i.e. prey’s spatial distribution is affected by natural enemy. And spatial association analysis showed that T. urticae and P. persimilis have positively associated. It means that T. urticae is relatively low mobile prey, and P. persimilis is relatively high mobile predator.
        10.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the current study, a total of 102 common Todarodes pacificus squid caught in the East Sea were investigated for parasitological research. The results revealed that 33 (32.35%) out of 102 squid were infected by Nybelinia surmenicola, the mean intensity was 5.58 parasites per squid, and the maximum abundance was 11. Morphological analysis using a field emission scanning electron microscope showed the characteristic features of N. surmenicola. Molecular identification based on the 28S rRNA gene confirmed the isolated parasite as N. surmenicola, while phylogenetic analysis revealed that N. surmenicola isolated in this study was clustered with N. surmenicola isolated from Japan. This is the first report of phylogenetic characterization of N. surmenicola isolated from Korea.
        4,000원
        11.
        2018.10 구독 인증기관·개인회원 무료
        본 연구는 호남지방 소비자 들의 곤충 제품과 관련하여 식품구매 행동, 곤충제품에 대한 인식, 식용, 학습, 애완용, 사료용 곤충에 대한 인식 등에 대한 기초 자료를 얻고자 수행하였다. 연구의 대상은 광주, 전주, 순천 등 대도시 학생과 성인 230여명을 대상으로 2018년 5월부터 9월까지 설문조사를 실시하였다. 설문조사 결과, 새로운 음식을 맛보는 소비자는 36%인고 맛보지 않는 소비자는 32%이지만 새로운 음식을 신뢰하는 소비자는 19%로 신뢰하지 않은 소비자 45%보다 더 적었으며 음식 재료를 모르면 맛보지 않은 소비자가 47%로 많지만 먹어 본적 없는 음식을 꺼리지 않고(46%), 까다롭지 않으며(45%), 무엇이든 잘 먹는(57%) 소비자가 더 많았다. 곤충 제품에 대한 인식은 곤충을 잘 알고 있으며(97%), 체험해보거나(89%), 구입해본 적이 있는(59%) 소비자가 더 많아 소비자들의 거부감이 크지 않음을 알 수 있었으며, 구입장소는 다양하고 주로 TV, 라디오를 통해(48%) 알게 되며 체험 종류나(59%), 구입 용도(63%)는 대부분 식,약용 곤충이었다. 식용곤충 구입은 어쩌다 한번이 79%로 아직까지 주기적으로 구입은 하지 않았으며 멋져 보이거나(54%), 건강을 생각하여(28%) 구입하는데 요리재료(46%), 건조, 튀김(24%) 형태로 누에(74%), 갈색거저리(6%), 흰점박이꽃무지(5%) 등을 구입하였다. 가격 만족도는 47%이며 품질(52%), 구입경로(53%), 맛(70%) 만족도도 긍정적으로 높았다.
        12.
        2018.10 구독 인증기관·개인회원 무료
        Gryllus bimaculatus is one of many cricket species known as field crickets. Also known as the African or Mediterranean field cricket or as the two-spotted cricket, it can be discriminated from other Gryllus species by the two dot-like marks on the base of its wings. G.bimaculatus is a subtropical insect and widely distributed from Africa to south Asia. After into the country, The species are popular for use as a food source for insectivorous animals like spiders and reptiles kept as pets. In 2016, was approved as a general food ingredient by Korean Ministry of Food and Drug Safety. However, domestic research on G.bimaculatus is still in its study is beginning stages. and analyze nutrtion elements as per dry conditions for processing&production of G.bimaculatus. The growth stage passing by 50 days after hatching was highest in general component and amino acid contents. The crickets passing by 50 days after hatching was highest 77% crude protein in condition hotair drying 60℃, 23% crude fat in condition freeze drying.
        13.
        2018.10 구독 인증기관·개인회원 무료
        Oxya chinensis sinuosa Mistshenko(Orthoptera:Acrididae) was lived in clean and non polluted area. grasshopper was approved as a general food ingredient by Korean Ministry of Food and Drug Safety. general component contents was 67~75% crude protein, 5~11% crude fat in a dried state. grasshopper is a high protein food. amino acids is high. In the composition and content of amino acids, which consists of the protein is the hightes alanine, glycine(soft and sweet) and arginine, histidine(essential amino acid of children) consequently, we developed a snack for children added with grasshopper powder. general composition of snack is 8~11% crude protein, 0.2~0.75% crude fat. The protein content increased with increasing addition ratio. 3% grasshopper powder was the best in general preference.
        14.
        2018.10 구독 인증기관·개인회원 무료
        상주는 귀농 도시이자 농업 중심 도시로써 농업기술원을 유치할 만큼 생태학적 연구가치가 있는 친환경 도시이다. 특히 경천섬은 낙동강 본류에 있는 상주보 인근에 위치하고 있어 낙동강 생태 환경 연구의 중요 지역 중 하나이다. 하지만, 아직 경천섬에 대한 생물다양성 연구가 부족한 상태이다. 섬과 산지의 생태환경이 다르기 때문에 생물의 다양성도 다를 것이라 간주하고, 경천섬 주변의 생태학적 가치를 재조명할 기초자료를 조사하고자 한다. 이에 경천섬과 인근에 위치한 청룡사 길목 산지에 서식하는 곤충 채집을 통해 생물다양성을 조사하여 비교분석하는 것을 목적으로 한다. 채집방법은 직접잡기, 쓸어잡기, 함정트랩, 흡충관을 이용하였으며, 함정트랩에 사용된 유인제는 소주1.8ℓ와 빙초산350㎖를 혼합하여 사용하였다. 2018년 4월~8월 중 3회 채집과정을 수행하여 목표개체수를 확보하였고, 채집된 곤충은 에탄올을 채운 conical tube에 넣어 냉동실에 보관하여 보존성을 높였다. 채집과정에서 잡은 곤충들을 건조시키고 유사종끼리 분류하고 동정하는 과정을 거쳐 다양도지수, 우점도지수, 종풍부도지수, 종균등도지수, 유사도지수를 계산할 것이다. 기존에 알려지지 않았던 경천섬 일대의 생물다양성을 세세하게 분석하는 과정을 통해 경천섬의 생태학적 가치를 드러내고, 경천섬 일대의 자연환경관리와 보존에 필요한 정보나 체계적인 관리체계를 구축할 기초자료를 제공하고자 한다.
        15.
        2018.05 구독 인증기관·개인회원 무료
        In this study, eye movements of drivers on expressway ramps were comprehensively investigated using raw data from driving simulator and eye tracker(MyGaze) deducted though the previous study. Based on the literature review, several parameters including number of fixations, fixation time, horizontal & vertical eye movements, and gaze position were selected. With them, eye movements of older drivers and young drivers were compared and investigated. Average fixation time of older drivers is shorter and tend to focus more on the inside road edge for both left and right turning ramps comparing young drivers. Also, they tend to look wider at right turning ramp. All driver’s fixation points were spread along the inside road edge for both left and right turning ramps. Currently, road delineating facilities are installed on the side where centrifugal force is applied. However, considering the result, it should be installed where centripetal force is applied. In addition, road line marking management should be more taken care of. For future study, vehicle’s speed is also in need of consideration with eye movement.
        16.
        2016.10 구독 인증기관·개인회원 무료
        Euzophera batangensis (Lepidotera: Pyralidae) is seriously damaging trunks or branches of persimmon tree (Diospyros sp.). We tested the attractiveness of (Z)-9-tetradecen-1-ol (Z9-14OH) and (Z9,E12)-tetradeca- 9,12-dien-1-ol (Z9,E12-14OH) with single or blended baits at southern parts of Korea in 2014 and 2015. The monoene was not attractive at all at three places during the two years. In 2014, diene was equally or more attractive than the mixture in Jinju and Suncheon, respectively. In 2015 too, the attractiveness of diene and mixture was not different in Jinju and Munsan. Monitoring of the seasonal occurrence of E. batangesis with the sex pheromone components revealed that it occurred three times a year; the first occurrence from early April to mid May, the second from early Jun to mid July, and the third from late August to late September.
        18.
        2012.06 구독 인증기관 무료, 개인회원 유료
        This study aims to examine the effect of Genetically Modified β -Carotene Biofortified Rice rice developed by simultaneous expression technology in NAAS on biological immunity. Accordingly, this study added Genetically Modified β-Carotene Biofortified Rice 25, 50% and general rice 50% as control group into diet and provided rats with the prescribed feeds and then measured the contents of immunoglobulin and cytokine in blood. As a result, male and female IgM, IgE, male IgG1, female IgG2a and TNF-a, IL5 and IL12 showed no significant difference; male IgG2a tended to decrease dependently on the combined concentration of Genetically Modified β-Carotene Biofortified Rice; female IgG1 showed significance with control group, but its association with diet was not found. The higher the dietary mixing ratio, the more the male and female IFN-a and female IL-4 contents, regardless of rice variety, and it was found that female IL6 content decreased significantly, but its association with diet was not found. The risk of beta carotene-enriched rice into environment and human body has not been reported yet. The digestion of Genetically Modified β-Carotene Biofortified Rice can be seen as "safe" as this test result showed no big difference between general rice and Genetically Modified β-Carotene Biofortified Rice, and its usability is full of suggestions.
        4,000원
        19.
        2011.09 구독 인증기관 무료, 개인회원 유료
        Periodontitis results from the activation of host immune and inflammatory defense responses to subgingival plaque bacteria, most of which are gram-negative rods with lipopolysaccharides (LPSs) in their cell walls. LPSs have been known to induce proinflammatory responses and recently it was reported also that they induce the expression of microRNAs(miRNAs) in host cells. In our current study therefore, we aimed to examine and compare the miRNA expression patterns induced by the LPSs of major periodontopathogens in the human gingival epithelial cell line, Ca9-22. The cells were treated with 1 μg/ml of E. coli (Ec) LPS or 5 μg/ml of an LPS preparations from four periodontopathogens Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Aggregatibacter actinomycetemcomitans (Aa), and Fusobacterium nucleatum (Fn) for 24 h. After small RNA extraction from the treated cells, miRNA microarray analysis was carried out and characteristic expression profiles were observed. Fn LPS most actively induced miRNAs related to inflammation, followed by Aa LPS, Pi LPS, and Ec LPS. In contrast, Pg LPS only weakly activated miRNAs related to inflammation. Among the miRNAs induced by each LPS, miR-875-3p, miR-449b, and miR-520d-3p were found to be commonly up-regulated by all five LPS preparations, although at different levels. When we further compared the miRNA expression patterns induced by each LPS, Ec LPS and Pi LPS were the most similar although Fn LPS and Aa LPS also induced a similar miRNA expression pattern. In contrast, the miRNA profile induced by Pg LPS was quite distinctive compared with the other bacteria. In conclusion, miR-875- 3p, miR-449b, and miR-520d-3p miRNAs are potential targets for the diagnosis and treatment of periodontal inflammation induced by subgingival plaque biofilms. Furthermore, the observations in our current study provide new insights into the inflammatory miRNA response to periodontitis.
        4,000원
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