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        검색결과 76

        43.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지진하중에 대한 구조물의 동적 거동과 내진성능을 평가하기 위하여 유사동적실험기법이 흔히 사용되고 있으나, 실험장비의 제약과 구조물의 규모 등으로 대부분 축소모형실험에 의존하고 있다. 그러나 일반적인 상사법칙은 탄성범위에서 유도된 것으로 지진거동과 같은 비탄성 거동을 예측하는 경우에는 한계가 있기 때문에 축소모형의 실험결과를 원형 구조물에 직접 적용하는 것은 많은 주의가 필요하다. 본 연구에서는 원형구조물과 축소모형에 대한 철골모형을 실험 대상으로 하여 실제 축소모형 실험결과로부터 원형구조물의 거동을 예측하는 경우의 문제점을 확인하고, 그 해결방법을 모색하고자 한다. 실제로 축소모형실험에서는 원형구조물의 경계조건을 정확히 재현하기 어려우며, 축소모형의 제작과정과 실험과정에서의 모든 오차가 강성의 변화로 반영되어 나타난다. 따라서 본 연구에서는 기하학적 상사율과 축소모형의 변화된 강성비를 함께 고려한 수정된 상사법칙을 제안하였으며, 수정된 상사법칙이 적용된 축소모형에 대하여 유사동적실험을 수행하여 지진응답결과를 원형구조물의 결과와 비교하였다. 축소모형에 대한 유사동적실험결과로부터 제안된 상사법칙을 적용함으로써 원형구조물의 지진응답 재현이 효과적임을 입증하였다.
        4,000원
        49.
        2017.05 서비스 종료(열람 제한)
        Background : Extraction is the first and the most important step in the recovery and purification of bio-active compounds from plant materials. Many important factors such as solvent, solvent composition, solvent to solid ratio, pH, and temperature significantly influence the extraction efficiency of bio-active compounds. Factorial design of a limited set of variables is advantageous when compared to the conventional method which varies a single parameter per trial. Methods and Results : The objective of this study was to screen independent factors, namely, ethanol concentration (60 – 100%), extraction temperature (40 – 80℃), time (6 – 18 hours), and liquid to solid ratio (10 – 50 ㎖/g) on the recovery of the extract yield, antioxidant capacity, phenolic and flavonoid contents from Dendropanax morbifera leaf using factorial design. Total flavonoid content of extract was determined by colorimetric method with aluminum chloride, while antioxidant activity was screened using the DPPH radical scavenging activity, TEAC and FRAP assays. Full factorial design was employed to determine the significant contribution of the above factors towards antioxidant capacity (TEAC, DPPH and FRAP), and flavonoid contents. Among, all the factors examined, ethanol concentration and extraction temperature are very significant (p < 0.0001), in obtaining higher antioxidant activity, total flavonoid contents. Conclusion : Two level full factorial design screening was successfully employed to determine the significant factors, which are ethanol concentration, temperature, time and liquid to solid ratio in contributing to high antioxidant capacity (TEAC, DPPH and FRAP), and flavonoid content determination from Dendropanax morbifera leaf. From the results obtained, ethanol concentration and temperature was very significant (p < 0.0001), in obtaining higher antioxidant activity and flavonoid contents. Further work on optimization using these significant factors are in progress.
        50.
        2017.05 서비스 종료(열람 제한)
        Background : For the GAP standard cultivation, weed occurrence pattern was investigated by planting density and mulching method of Bupleurum falcatum L. Methods and Results : Vinyl and rice straw were used for mulching. The planting density were 10, 20, and 30 cm, and the spacing between plants were 5 ㎝. The amount of weed emergence were examined twice at the end of July and at the end of September. The degree of importance was based on the Braun-Branquet’s dominance value distinction criterion. As a result, the kind of total weeds emerged during the cultivation of Bupleurum falcatum L. were identified as 20 species in 10 families. Amount of weed’s occurrence were the highest in rice straw covering after 10 × 5 ㎝ sowing, and it were lowest in vinyl mulching after 30 × 5 ㎝ sowing. The frequency of weed emergence was highest with 10 species of 8 families in rice straw mulching treatment. On the other hand, the treatment with the least emergence frequency of weeds was 30 × 5 ㎝ sowing after vinyl mulching, and weeds of 7 species of 6 families appeared. In the second survey in September, weeds of 15 species in 9 families were identified in the test field. The amount of weed’s occurrence were the highest in rice straw mulching after 10 × 5 ㎝ sowing, and it were the least in the case of vinyl mulching after 30 × 5 ㎝ sowing. The frequency of emergence of weeds was highest in rice straw mulching after 20 × 5 ㎝ sowing, and the kind of weeds were 11 species of 8 families. The treatment of the lowest emergence frequency of weeds was 30 × 5 ㎝ sowing after vinyl mulching. Three kinds of weeds occurred. Conclusion : From the above results, it is expected that we can suppress the weed occurrence at the planting density of 30 × 5 ㎝ after vinyl mulching at the sowing of Bupleurum falcatum L.
        51.
        2017.05 서비스 종료(열람 제한)
        Background : Gangwon-do (Province) is chief producing district of six-year-old raw material of red ginseng and transplanting culture is more than 90%. The 6-year-old red ginseng is easy to differentiate in quality and can secure a stable market, but it has high disadvantages such as high seedling cost, effort cost, and long term cultivation. Therefore, it is necessary to develop environment-friendly products that enhance price competitiveness based on 3 to 4-year-old ginseng by using direct seedling cultivation techniques. When ginseng seed sown directly, it is highly productive and has high disease resistance, which is advantageous for environment-friendly cultivation. Thus, it is advantage to save work force in seed production stage. The purpose of this study is to find the planting density for 4-year-old ginseng. Methods and Results : In order to determine proper planting density, ginseng growth characteristics such as root length, root diameter, raw weight, and yields were investigated at 4-year-old ginseng after planting 34, 67, and 100 roots per ㎡. As a result, the root length was the longest at 33.9 ± 5.45 ㎝ in 67 roots/㎡, and there was no difference in root diameter. The raw weight of 4-year-old ginseng was the highest at 65.1g in 34 roots/㎡. However, yields were 4.3 ± 0.78 and 4.8 ± 0.50 ㎏ in the 67 roots/㎡ and 100 roots/㎡, respectively, which were higher than the 34 roots/㎡. Conclusion : The proper planting density for direct seedling cultivation of yunpung cultivar was 67 - 100 roots/㎡, and these results could be applied to increase productivity in direct seeding cultivation of ginseng.
        52.
        2017.05 서비스 종료(열람 제한)
        Background : The Production of high quality ginseng seedling become increasingly important in the cultivation of ginseng because the quality of ginseng seedling is closely related to yield of ginseng. However, it has become difficult to produce high quality ginseng seedling due to environmental instability such as an increase in the occurrence of abnormal climate and pests, and the difficulty in obtain new place to cultivate ginseng seedling. This study was carried out to analyze the growth characteristics of ginseng seedling according to application of fermented compost during ginseng seedling cultivation Methods and Results : In order to evaluate the effect of fermented compost on the growth of ginseng seedling, fermented compost containing antagonistic microorganism was prepared and applied 300kg per 10a to planned place for ginseng cultivation. After seeding of the ginseng seeds, the growth of ginseng was analysed. The pH, EC, organic matter, P2O5 and NO3-N of the compost treated group were 6.1, 2.75 ds/m, 18.97 g/㎏, 1,202 ㎎/㎏ and 287.4 ㎎/㎏, respectively, while those of non-treated group were 6.6, 0.25 ds/m, 14.67 g/㎏, 1,055 ㎎/㎏ and 8.77 ㎎/㎏, respectively. As a result of analyzing the growth characteristics of ginseng seedling, the growth of aboveground part was not significantly different between the treated and non-treated group. The root length and root diameter were 13.0 ± 1.50 ㎝ and 5.5 ± 0.27 ㎜, respectively, which were not significantly different from non-treated group. However, root weight was 1.20 ± 0.14 g, which is 1.4 times higher than that of control. Conclusion : It was confirmed that the quality of ginseng seedling was improved by compost application. These results suggested that fermented compost could be used as a material for nutrients management in ginseng seedling cultivation.
        53.
        2016.10 서비스 종료(열람 제한)
        Background : Angelica dahurica Bentham et Hooker, Angelica gigas Nakai, Ostericum koreanum Maximowicz and Peucedanum japonicum Thumberg are a major medicinal plant in north Geungbuk province. Using medicinal plants are impotant it`s ingredient. Dry condition and stroage method are not standard manual. The ingredient variation of dry condition and stroage method were not researched. Methods and Results : Using plant material were cutivated on Gyongsangbukdo Bonghwa area. It were studied ingredient variation after dry and storage condition by HPLC methods. Major ingredient of Angelica gigas Nakai are decurusin, decurusinangelate. Heated air bulk dry get more decursin than natuarl dry and decurusinangelate of natural bulk dry was higher than heated air bulk dry. Major ingredient of Ostericum koreanum Maximowicz are imperatorin and isoimperatorin.. Imperatorin of Ostericum koreanum was highest peak on 50℃ heated-air dry after plastic bag sorage and isoimperatorin was highest peak on 40℃ heated-air dry after mountain cultivation. Imperatorin is a major ingredient Angelica dahurica Bentham et Hooker. Heated air bulk dry get more decursin and decursinangelate than natuarl dry and small heated-air dry. Peucedanol-7o_glucoside is a major ingredient Peucedanum japonicum Thumberg. Natural bulk dry get more peucedanol-7o_glucoside than heated-air bulk dry. Conclusion : Ingredient of Angelica dahurica Bentham et Hooker, Angelica gigas Nakai, Ostericum koreanum Maximowicz are different under various cutivation, drying method, storage. Diffent Ingedients of Angelica gigas Nakai, Ostericum koreanum Maximowicz were not accord it’s optical conditon.
        54.
        2016.10 서비스 종료(열람 제한)
        Background : Some of invasive plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plants in Korea, particularly in Jeju Island, invade farmland, and autochthonous forest, establishing monocultures and modifying the ecosystem structure. This invasive species has become a serious environmental problem because they displace the indigenous plant species. This study was conducted to evaluate the antioxidantive effects of ethanolic extracts from different parts (root, stem, seed and leaf) of the invasive exotic species Hypochaeris radicata L. Methods and Results : The aim of present study was to estimate the total phenolic and flavonoid contents and to investigate in vitro antioxidant potential of ethanolic leaf, root, seed, and stem extracts of the Hypochaeris radicata. Antioxidant activity was assessed by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, reducing power activity, [2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] ABTS+ assay and ferrous ion chelating activity. The total phenolic and flavonoid contents were also determined and expressed in gallic acid and quercetin equivalent respectively. The results of the study indicate that the ethanolic extracts of the leaf, root, seed, and stem of H. radicata posses significant scavenging activity against DPPH (21.25% for leaf, 34.98% for root, 60.76% for seed and 45.25% for stem at 250 μg/ml each) and ABTS+ radical scavenging activity (14.85% for leaf, 17.40% for root, 35.91% for seed and 24.70% for stem at 250 μg/ml each), reducing power activity (0.178 absorbance at 300 μg/ml for leaf, 0.211 absorbance at 300 μg/ml for root, 0.447 absorbance at 300 μg/ml for seed, 0.276 absorbance at 300 μg/ml for stem). The free radical scavenging and antioxidant activities may be attributed to the presence of adequate phenolic (gallic acid content is 361.92.98 μg/g in leaf, 356.59μg/g in root, 719.72 μg/g in seed and 512.08 μg/g stem) and flavonoid compounds (219.52 μg/g in leaf, 75.67μg/g in root, 281.39 μg/g in seed and 215.66 μg/g stem). This study revealed that the ethanolic extracts of both leaf, root, seed and stem of H. radicata has demonstrated significant antioxidant activity. Conclusion : In conclusion, the present study has demonstrated that Hypochaeris radicata seed ethanol extracts are rich in phenolics and have a strong antioxidant activity and a radical-scavenging action in all of the tested methods. This suggests that Hypochaeris radicata is a good source of natural antioxidants.
        55.
        2016.10 서비스 종료(열람 제한)
        Background : More than 1250 bamboo species, belonging to 75 genera, are distributed all over the world. Sasa quelpaertensis Nakai is a type of bamboo grass widely distributed in Halla mountain, Jeju Island, which has been used as antidiabetic, anti-cancer and anti-inflammatory drugs. In this study, we investigated the antioxidant and antimicrobial activities of Sasa quelpaertensis Nakai leaf extracted with different ethanol concentration and demonstrated the potent bioactivities of the extracts suitable to be used as natural antioxidant compounds or pharmaceutical supplements. Methods and Results : Antioxidant and anti-microbial activities of Sasa quelpaertensis Nakai extracts were studied. At first, different ethanol concentrations (0, 20, 40, 60 and 80%) were compared for determining of the best solvent for extraction of phenolic compounds from Sasa quelpaertensis Nakai. Forty percent Ethanol extract with 990.01±28.9 (mg of gallic acid equivalents/g sample) were the best solvent in the extraction of phenolic compounds. But, 60% ethanolic extracts were highest antioxidant activity appeared such as DPPH radical scavenging (IC50 21.20±0.42 μg/ml), ABTS radical scavenging (IC50 49.85±1.27 μg/ml) and reducing power. However, 80% ethanol extracts showed the strongest SOD like activity. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and yeast. Sixty percent and 80% ethanol extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 125 μ g/ml and 250 μg/ml for the 60% and 80% extracts, respectively. Conclusion : The results of this study show that the extract of Sasa quelpaertensis Nakai can be used as easily accessible source of natural antioxidants and as a possible food supplement or in pharmaceutical industry. However, the components responsible for the antioxidant and antimicrobial activities of both extracts of Sasa quelpaertensis Nakai are currently unclear. Therefore, it is suggested that further works should be performed on the isolation and identification of the antioxidant components in Sasa quelpaertensis Nakai.
        56.
        2016.10 서비스 종료(열람 제한)
        Background : This study for the stable production and supply of seeds of Angelica gigas Nakai(Man-chu Korean Angelica), when seeds harvested using nets, seed productivity was investigated. Methods and Results : Planting density is 50 × 25cm, Fertilizer per 10a was sprayed amount of N-P2O5-K2O = 16-17-10kg. And the amount of compost per 10a was sprayed 3000kg. Seed harvesting nets were used for a time formed the endosperm of the seeds (later in mid-August to late). And net for seed production was used for onion nets (at least 13 × 18cm). Shoot growth conditions were as follows. Bolting rate was 89.0% in the untreated, the treated group was 93.1%. The length and thickness of each stem was 129.3 ~ 130.8cm, 1.8cm. The number of nodes per plant was 6.7 ~ 7.5 pieces, and the number of petiole was 14.8 ~ 15.5 per plant. The number of umbel was 10.3 ~ 11.1 piece per plant, and number of deleted umbel was 7.1 ~ 7.2 piece. Seed weight per plant was 24.2g of the net treatment, but ripening seeds 19.6g, 1000 grain weight were all treated and untreated 2.8g. The total seed weight per plant, the net treated was 24.2g, was the weight of the ripening seeds 19.6g. The weight of the ripening seeds were heavier than those of the control. However, the weight of 1000 grain were both treated and untreated 2.8g. When treated nets, the total seed yield per 10a was 88.0kg production, increased by 60.9% compared to untreated. In addition, the ripening seed production per 10a was 71.5kg production, increased by 50.1% compared to untreated. Researching after germination Seed Production, germination rate was 50.8% in the control group and the treatment group was 54.9%. When applying the germination rate, high-quality seed production per 10a was able to produce 39.2kg, compared to control obtain the results increased by 65%. Conclusion : Through the above results, When producing angelica seed, use of net for seed production is thought to be used as a way to prevent early shattering and insect damage.(True bug, etc.).
        57.
        2016.10 서비스 종료(열람 제한)
        Background : Recently, some of the previous stuies reported that was useful technique on growth and yield of organically grown ginseng transplantation in a rain shelter greenhouse. This study was conducted to investigate the optimum method of greenhouse shading for ginseng(Panax ginseng C. A. Meyer) cultivaton in the northern area of Ganwon, Korea. Methods and Results : We carried out to select optimal shade materials and light-penetrated ratio among polyethylene film with two-layered polyethylene net(PEF+PEN) and blue-white duplicated PE film(BWD-PEF) in the condition of greenhouse for ginseng cultivation. The order of light-penentrated ratio by shade meterials was PEN(75%)+PEF 〉 PEN(85%)+PEF 〉BWD-PEF(85%) 〉BWD-PEF(90%) and the order of air temperature was BWD-PEF(85%) 〉BWD-PEF(90%) 〉PEN+PEF(85%) 〉PEN+PEF(75%). The net photosynthetic rate was higher in PEN(75%)+PEF than other shading material treatments during growth season including summer high-temperature period. The root weight and yield were increased by 31.2~55.0% and 25.6~52.2%, respectively under PEN+PEF(75%) compared to other shading materials. Conclusion : We concluded that the PEN+PEF(75%) could be a good shading meterails of the greenhouse for organic 4-year-old ginseng cultivation in northern area of Gangwon, Korea.
        58.
        2016.10 서비스 종료(열람 제한)
        Background : The Aralia cordata and Dendropanax morbifera, belonging to the family Araliacea, is a perennial herbaceous species. Although its beneficial effects for several chronic diseases are well-known, the role of its effects on chronic intestinal inflammation, colon carcinogenis are limited. Inflammatory bowel diseases (IBD) are chronic inflammatory disorders of gastrointestinal tract. It has been reported that IBD is associated with colon cancer which is one of the most common types of cancer diagnosed and a major cause of cancer-related mortality. Methods and Results : The present study hypothesized that Araliacea family would exert a protective effect on inflammation and dextran sulfate sodium (DSS)-induced colitis mouse model. Effect of Aralia cordata extracts (ACE) and Dendropanax morbifera leaf extracts (DMLE) on pro-inflammatory markers, mitogen-activated protein kinase signaling (MAPKs), activation of nuclear factor κB (NF- κB) in THP-1 human monocyte and HT-29 colon epithelial cell model were investigated. In addition, colon inflammation inhibitory effects of ACE and DMLE on the characteristics of in DSS-induced colitis model. Results showed that ACE, DMLE attenuated the severity of DSS-induced colitis, as assessed by disease activity index scores, shrinkage of colon length, and histopathologic changes and infirmatory cytokine concentration. Furthermore, ACE treatment significantly suppressed the colon carcinogenesis in AOM/DSS induced colon cancer model. The apoptosis induction abilities of the DMLE were studied by analyzing the expressions of Bcl2 family protein, caspase, Annexin V/PI staining and DNA fragmentation. According to our results, DMLE significantly induced cell death in SW-480 cells. Apoptosis was determined by cell morphology and electrophoresis of DNA fragmentations. Furthermore, treatment with DMLE also induced the increase in caspase activity, pro-apoptotic proteins (Bax and Bad) and the decrease in anti-apoptotic proteins (Bcl-2 and Bcl-xL). In addition, DMLE induce cell cycle arrested at the G1/S phase in SW-480 cells and exhibited significant inhibition on the expressions of G1/S phase specific CDK, cyclin and up regulation of CDK inhibitors. Conclusion : Taken together, these results provide evidence that ACE and DMLE prevention colon cancer by regulating inflammation, colitis, and colon carcinogenesis which indicates its benefit for colon health.
        59.
        2016.05 서비스 종료(열람 제한)
        Background : Cylindrocarpon root rot, caused by Cylindrocarpon destructans and Fusarium solani, is a major disease which lead to replanting failure in ginseng garden. Chlamydospores of C. destructans, generated by poor environmental condition, can survived more than ten years in soil without host plant, ginseng. Density of soil pathogens gradually decreased as the progress of time since ginseng was harvested. Methods and Results : Soil chemical properties was analyzed from soil samples of 43 regions in farmer’s ginseng garden to study the variation of content and the correlation among inorganic contents. Soil samples of 24 regions was also analyzed to study correlation between progressed-year after ginseng harvest and soil chemical properties. Variation of soil chemical properties in descending order was Fe, Zn, P2O4, NO3, Mn. The content of Fe and Zn were great variation among inorganic chemicals of soil of farmer’s field. Electrical conductivity to induce physiological demage in excessive concentration showed highly significant positive correlation with the content of NO3 and K. As the progress of year after ginseng harvest, the content of organic matter and zinc was increased, while pH and Na were decreased in farmer’s field to cultivate ginseng. There were highly significant positive correlation between the progress of year after ginseng harvest and zinc content in farmer’s field to cultivate ginseng. Ratio of root rot of 2-year-old ginseng showed significant positive correlation with K content, and negative correlation in experimental field cultured by six rotation crops for one year. Conclusion : Root rot by soil pathogens was closely related with the content of potassium and zinc in soil chemical properties.
        60.
        2016.05 서비스 종료(열람 제한)
        Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.
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