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        검색결과 274

        81.
        2018.04 구독 인증기관·개인회원 무료
        The ambrosia beetle, Xyleborinus saxesenii Ratzeburg, infests physiologically stressed apple and peach trees in Korea. Dispersing females utilize the degradation product ethanol and host-related volatiles to locate and colonize new host trees. We examined the extent to which 12 chemicals emitted from fruit trees act synergistically with ethanol to attract X. saxesenii. The addition of benzaldehyde to ethanol significantly increased beetle attraction, although benzaldehyde was not attractive by itself. The addition of α-pinene, ethyl butyrate, ethyl isovalerate, limonene, 3-methyl-1-butanol, ethyl tiglate, aromadendrene, vanillin, 2-butanol, styrene, or ethyl 3,3-dimethylacrylate to ethanol had no effect on beetle attraction. In a dose-response test, the addition of 5–50% benzaldehyde doses synergistically increased the number of beetle captures; however, trap catches did not increase as the benzaldehyde dosage increased. The synergistic influence of benzaldehyde on beetle response to ethanol was lower in early spring than in late summer to early fall, probably because synthetic benzaldehyde emissions from field lures were overwhelmed by background levels of natural benzaldehyde emitted from peach twigs in the flowering stage.
        82.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The electronic and optical characteristics of molybdenum disulphide (MoS2) film significantly vary with its thickness, and thus a rapid and accurate estimation of the number of MoS2 layers is critical in practical applications as well as in basic researches. Various existing methods are currently available for the thickness measurement, but each has drawbacks. Transmission electron microscopy allows actual counting of the MoS2 layers, but is very complicated and requires destructive processing of the sample to the point where it will no longer be useable after characterization. Atomic force microscopy, particularly when operated in the tapping mode, is likewise time-consuming and suffers from certain anomalies caused by an improperly chosen set point, that is, free amplitude in air for the cantilever. Raman spectroscopy is a quick characterization method for identifying one to a few layers, but the laser irradiation causes structural degradation of the MoS2. Optical microscopy works only when MoS2 is on a silicon substrate covered with SiO2 of 100~300 nm thickness. The last two optical methods are commonly limited in resolution to the micrometer range due to the diffraction limits of light. We report here a method of measuring the distribution of the number of MoS2 layers using a low voltage field emission electron microscope with acceleration voltages no greater than 1 kV. We found a linear relationship between the FESEM contrast and the number of MoS2 layers. This method can be used to characterize MoS2 samples at nanometer-level spatial resolution, which is below the limits of other methods.
        4,000원
        83.
        2017.10 구독 인증기관·개인회원 무료
        This study was conducted to in vitro antioxidant and anti-inflammatory activities of EtOH extracts of Cordyceps militaris (CM). Antioxidant potential, total phenolic and flavonoid contents of CM EtOH extracts were determined by Folin-Ciocalteu method and the aluminum chloride colorimetric method, respectively. Antioxidant activity of CM extracts was measured by following some well-established methods for free radical scavenging such as 2,2-diphenyl-picrylhydrazyl hydrate and 1,2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid). Moreover, Anti-inflammatory activity of CM extracts was determined by measuring the inhibition of nitric oxide (NO) production in lipopolysaccharide/interferon-γ-activated RAW264.7 macrophage-like cells. In addition, cytotoxicity of CM extracts against macrophages was determined by MTT assay. Our results showed that total phenolic content was 19.7 mg gallic acid/g extract. Total flavonoid content was 5.0 mg Naringin/g. Its antioxidant activity was assessed by IC50 value and the values are 338.8 μg/ml (DPPH radical scavenging), 35.4 μg/ml (ABTS radical scavenging). In addition, CM extracts attenuated NO production through the reduction of cellular inducible NO synthase protein expressions. Using MTT assay on indicate that CM extracts showed no toxicity. In conclusion, these results provide important evidence that CM extracts can potentially be used to antioxidant and anti-inflammatory agent.
        84.
        2017.10 구독 인증기관·개인회원 무료
        Occurrence spontaneous mushrooms in eastern Jeju Muryeongarioreum, Sillyecheon-Iseungak, Kyoraegotjawal, Geomunoreum were examined in 2016. The collected mushrooms were classified by 15 order 56 family 149 genera 317 species. Among the collected mushrooms, 87 species of mushrooms were successfully incubated in mushroom complete medium in which DNA of 25 species were completely extracted and amplified using universal primers ITS1 (5’-CTTG GTCA TTTA GAGG AAGT AA-3’) and ITS4 (5’-TCCT CCGC TTAT TGAT ATGC-3’). Four species of them were differently identified between the classification by morphological observation and by analysis of DNA sequences i.e. by morphological identification Ganoderma applanatum, Armillaria gallica, Macrolepiota procera and Trametes gibbosa were identified as G. gibbosum, A. cepistipes, M. detersa and T. elegans by analysis of DNA sequences, respectively. Based on these results both identification ways might be necessary for correct classification of mushrooms. On the other hand, among the collected 317 mushrooms, 48 species could be identified to genus but not to species by the morphological observations. However, by the analysis of DNA sequences, 15 species were identified to species in which 6 species were unregistered mushrooms in Korea. Therefore, the analysis of DNA sequence may be useful to identify the mushrooms which are difficult to recognize by morphological observation.
        85.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ginger was steamed at 121 o C and 1.5 lb/in 2 for 30 min, dried at 60 o C for 12 h, and each step was repeated nine times. During processing, the lightness (L* value) and yellowness (b* value) decreased from 85.65±0.33 and 26.99±0.20 in the non-treated ginger to 56.91±0.25 and 16.69±0.06 in ginger treated for the ninth treatment. On the other hand, redness (a* value) increased from -1.51±0.03 to 7.34±0.08 on the eight treatment and then decreased to 7.21±0.04 on the ninth theatment. The contents of 6-gingerol decreased from 3.257±0.067 mg/g in the non-treated ginger to 0.567±0.036 mg/g on the theatment, whereas the contents of 6-shogaol increased from 1.299±0.050 mg/g to 2.999±0.089 mg/g on the sixth treatment and decreased to 2.099±0.039 on the ninth treatment. The contents of 10-gingerol decreased slightly from 1.106±0.125 mg/g to 0.806±0.026 mg/g. Unlike the 6- and 10-gingerol, the contents of 8-gingerol did not change greatly, with values between 0.916±0.005 mg/g and 1.106±0.005 mg/g being observed during processing. The tyrosinase inhibitory activities were increased from 43.42±11.45% in the non-treated ginger to 100% on the sixth treatment and then decreased to 51.98±7.36% on the theatment. The antioxidative activity was retained during processing.
        4,000원
        86.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Earthworms, especially Eisenia andrei, are cultivated for a variety of purposes including waste disposal and compost production. In this study, bacteria from earthworm gut were cultured and the dominant species identified. Subsequently, we isolated bacteriophages able to lyse the isolated gut bacteria. Two dominant genera of gut bacteria, Aeromonas sp. and Citrobacter sp. were identified by using MALDI-TOF MS analysis and a library was constructed to find lytic phages. Phage EF1 showed lytic activity for C. freundii and two Citrobacter isolates, C. braakii and C. murliniae. These 3 species have similar sensitivities to EF1. Several aspects of the life cycle of EF1 were investigated by using C. freundii under optimal growth conditions. EF1 infects C. freundii with a moderate latent period, approximately 25 min, and a large burst size averaging 5 × 109 per infected cell. Moreover, the antimicrobial activity of EF1 was well maintained under diverse conditions including a broad temperature range of 40°C to 50°C and a wide pH range of 4 to 11. In conclusion, the results indicate that earthworm casting contain a wide range of bacteria species, for which there are various corresponding bacteriophages.
        4,000원
        88.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The genetic algorithm (GA), one of the artificial intelligence (AI), is developed based on Darwin's theory of evolution, i.e., the mating of randomly selected objects. If more optimal solution is generated, then it is better to repeat the process of setting the optimum value. In this paper, the method of background music using the genetic algorithm is exploited when the computer game is executed each time. As a result, it has created several music that can be used in the actual game, and it could be confirmed that the other music that is created is different music when performed each time.
        4,000원
        89.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the present study, exfoliated graphite nanoplatelets (xGnP) with different particle sizes were coated onto polyacrylonitrile-based carbon fibers by a direct coating method. The flexural properties, interlaminar shear strength, and the morphology of the xGnP-coated carbon fiber/phenolic matrix composites were investigated in terms of their longitudinal flexural strength and modulus, interlaminar shear strength, and by optical and scanning electron microscopic observations. The results were compared with a phenolic matrix composite counterpart prepared without xGnP. The flexural properties and interlaminar shear strength of the xGnP-coated carbon fiber/phenolic matrix composites were found to be higher than those of the uncoated composite. The flexural and interlaminar shear strengths were affected by the particle size of the xGnP, while the particle size had no significant effect on the flexural modulus. It seems that the interfacial contacts between the xGnP-coated carbon fibers and the phenolic matrix play a role in enhancing the flexural strength as well as the interlaminar shear strength of the composites.
        4,000원
        90.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Fatigue crack growth experiments were carried out on a 304 L stainless steel compact-tension(CT) specimen under load control mode. Neutron diffraction was employed to quantitatively measure the residual strains/stresses and the evolution of stress fields in the vicinity of a propagating fatigue-crack tip. Three principal stress components (i.e. crack growth, crack opening, and through-thickness direction stresses) were examined in-situ under loading as a function of distance from the crack tip along the crack-propagation path. The stress/strain fields, measured both at the mid-thickness and near the surface of the CT specimen, were compared. The results show that much higher compressive residual stress fields developed in front of the crack tip near the surface than developed at the mid-thickness area. The change of the stresses ahead of the crack tip under loading is more significant at the mid-thickness area than it is near the surface.
        3,000원
        91.
        2015.10 구독 인증기관·개인회원 무료
        Grapholita molesta occur four times a year and Carposina sasakii occur twice a year, and both pests do damage on stone fruits such as peach, apple, plum, apricot, etc. Grapholita molesta is worldwide distributed in temperate and subtropical areas including South Korea. But, Carposina sasakii distributed in South Korea, Japan, China and Asia, and has been managed as an important import quarantine pest by the authorities of United States, Canada and Taiwan. Forecasting of both pests in Korea is currently done through the investigation of 1,000 fruits per 10 trees (100 fruits / tree) in designated peach orchard. However, this method is very difficult to observe the pest by bagging of peach and require too much time and labor. Therefore, we tried to carry out a new forecasting method by using of sex pheromone traps for newly standardized method as an alternative. Using sex pheromone trap, attractiveness of G. molesta was proved to be 2.5 > 1.5 > 0.5 m by the height and the border => outside > center by the position. Attractiveness of C. sasakii made no difference in height, but, more trapped at the center and border than outside in position at peach orchard.
        92.
        2015.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In-situ neutron diffraction has been employed to examine the effect of strain path on lattice strain evolution during monotonic and cyclic tension in an extruded Mg-8.5wt.%Al alloy. In the cyclic tension test, the maximum applied stress increased with cycle number. Lattice strain data were acquired for three grain orientations, characterized by the plane normal to the stress axis. The lattice strain in the hard {10.0} orientation, which is unfavorably oriented for both basal slip and {10.2} extension twinning, evolved linearly throughout both tests during loading and unloading. The {00.2} orientation exhibited significant relaxation associated with {10.2} extension twinning. Coupled with a linear lattice strain unloading behavior, this relaxation led to increasingly compressive residual strains in the {00.2} orientation with increasing cycle number. The {10.1} orientation is favorably oriented for basal slip, and thus showed a soft grain behavior. Microyielding occurred in the monotonic tension test and in all cycles of the cyclic test at an applied stress of ~50 MPa, indicating that strain hardening in this orientation was not completely stable from one cycle to the next. The lattice strain unloading behavior was linear in the {10.1} orientation, leading to a compressive residual strain after every cycle, which, however, did not increase systematically from one cycle to the next as in the {00.2} orientation.
        4,000원
        93.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We quantified temporal and spatial changes in the habitat for fish populations, the distribution of mandarin fish(Siniperca scherzeri) and an introduced species, largemouth bass(Micropterus salmoides) in Lake Paro and inflowing streams. The number of fish species identified in Lake Paro and the tributary streams included 10 families, 24 species and 10 families 30 species, respectively. The dominant fish species in Lake Paro were Zacco platypus, Hemibarbus labeo, Squalidus gracilis majimae, S. scherzeri and Tridentiger brevispinis, Z. platypus, Z. koreanus, and S. gracilis majimae in the inflowing streams. Although the habitat segregation for S. scherzeri and M. salmoides occurs, these two species showed the use of the fishes of the family Gobiidae as an important prey item based on IRI analysis. S. scherzeri and M. salmoides preyed mainly on T. brevispinis(67.4 %) and R. brunneus(84.0 %), respectively. The species preyed on by S. scherzeri and M. salmoides were benthic fishes that inhabit shallow water depths around the lake and have little swimming ability.
        4,200원
        94.
        2015.04 구독 인증기관·개인회원 무료
        Damages of medicinal crops by thrips and identification of thrips species were investigated on major medicinal crops, Platycodon grandiflorum, Schizandra chinensis, Codonopsis lanceolata, Lycium chinense, Bupleurum falcatum, Ledebouriella seseloides, Angelica gigas, Glycyrrhiza uralensis, Liriope platyphylla, Atractyloides sp., in Suwon, Eumseong, Jecheon, Pyeongchang, Chyungyang 2012. Thrips and their damages were found at all of the medicinal crops investigated, mostly occurring at early growing stages of each medicinal crop and causing apical meristem region withered, thereby inhibiting the growth of plants. As a result, Frankliniella intonsa, Thrips tabaci, and Megalurothrips distalis have been identified as dominant species on medicinal crops in open field, whereas Frankliniella occidentalis was restricted to Lycium chinense in which protected cultivation. Occurrence of thrips species on medicinal crops seems to be affected by host specificity and environmental factors such as cultivation types.
        95.
        2015.04 구독 인증기관·개인회원 무료
        The Chrysomelid species of the genus Xanthogaleruca, X. aenescens Fairmaire, 1878 is reportd for the first time from South Korea. The genus Xanthogaleruca Laboissiére, 1934, within subfamily Galerucinae, contains only nine species, and is distributed Palearctic region (Beenen, 2010), but one adventive species, X. luteola (Müller, 1766), is widespread throughout much of Canada, North Africa and the United States. Also known as the elm leaf beetle, it feed on Ulmus (Ulmaceae). In the present study we report on the genus Xanthogaleruca Laboissiére, 1934 from Korea for the first time, based on X. aenescens Fairmaire, 1878. We provide the habitus photographs, illustrations of diagnostic features and a key to the genus in S. Korea.
        96.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to find out an inspiratory muscles training program’s therapeutic effects on stroke patients’respiratory function. For the purpose, this study targeted 20 stroke patients being hospitalized in K hospital in Daegu, and diveded the patients into the both groups of Inspiratory muscle training(IMT) group and control group, randomization. The 10 patients in the IMT group was applied the inspiratory muscles training. The control group was composed of other 10 patients. IMT group was given a inspiratory muscle training program for 30 minutes per times, 5 times a week for 6 weeks. The investigator measured the patients’respiratory function compared changes in the function and ability before and after the IMT. The results of this study are as follows. Investigating the inspiratory muscle training group’s lung functions, there appeared some significant differences in the tests the FVC(Forced vital capacity), FEV1(Forced expired volume in one second) before and after the training(p<.05), but the control group had no significant in the same tests before and after(p<.05). The differences in the both groups after depending the inspiratory muscles training were significantly found in the tests of FVC, FEV1, FEV1/FVC(p<.05). The maximum inspiratory pressure showed some significant differences in the inspiratory muscle training group(p<.05), but didn't show any significant difference in the control group(p>.05). Conclusionally, it will be judged that the inspiratory muscles training program will improve stroke patients’respiratory function, and it is considered that will move up stroke patients’gait and body function.
        4,000원
        97.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The currently cultivated varieties of moth orchid flowers have weak or no fragrance and the plant requires high temperatures for cultivation. In order to develop a new variety of orchid that is psychrophilic and fragrant, intergeneric cross between wild wind orchids and moth orchids was performed. In 2009, To obtain intergeneric hybrids from Sedirea japonicum and Neofinetia falcata with moth orchids, artificial crosses with a total of 160 combinations were performed. Most of the cross combinations failed due to crossincompatibility after intergeneric crosses, with no pod formation, premature pod dropping after pod formation, and pod formation that did not produce seeds. From among these, the crosses that formed normal seeds and germinated to produce viable plants included Doritis pulcherrima × S. japonicum, N. falcata × D. pulcherrima, and N. falcata × P. equestris. From the hybrid specimens obtained through these crosses, 2 superior lines (819-3B and K9256) were selected based on their floral morphology, number of flowers, hardiness, and fragrance. Comparative analyses of the morphological and chromosomal traits were performed between the selected hybrid specimens and their parents. The flower and inflorescence characteristics of the selected hybrids exhibited intermediary traits of both the parents; however, more traits from the moth orchids were inherited. For pollinia traits, both 819-3B and K9256 specimens exhibited intermediate forms of their parents in terms of their shape and size. In the case of 819-3B specimen, a high degree of trait similarity with that of D. pulcherrima was observed; whereas, K9256 specimen showed lobes similar to that of P. equestris. The ploidy of moth orchid, S. japonicum, and N. falcata used for crosses was diploid, as determined by microscopic examination and ploidy analysis. The microscopic examination of chromosomes from the intergeneric hybrid pollens revealed mutation of the chromosome count among different specimens as well as irregular chromosome separation. For the production of next-generation progeny using the obtained hybrids, back-cross was performed; however, most of the progeny obtained were sterile and, among the 12 back-crosses, pod formation was noted in S. japonicum × 819-3B and 819-3B × S. japonicum crosses only.
        4,000원
        98.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study were to evaluate the antimicrobial effects of ε-poly-L-lysine mixture (EPM) on cheon-ggukjang and to determine the optimal mixing ratio in cheonggukjang. Increasing the EPM up to 2% decreased via-ble cell counts at both 15oC and 30oC storage. The pH of cheonggukjang without EPM increased slowly over thestorage periods, but cheonggukjang with EPM showed a slight increasing tendency, with the highest pH at 2% EPM.The sensory scores, such as texture and flavor, were highest in samples containing 2% EPM; however, overall pref-erence was not significantly different when compared to the control. For the optimum cheonggukjang processingconditions, 13 experimental points were selected. Soybean and EPM were chosen as independent variables. Viablecell count, pH, texture, and overall preference were measured. The optimum formulation of cheonggukjang usingthe numerical analysis was found to be 98.52% soybean and 1.48% EPM, resulting in a 0.722 desirability value.
        4,000원
        99.
        2014.04 구독 인증기관·개인회원 무료
        Conservation biological control (CBC) is one of the pest management tactics based on protecting and maintaining natural enemies that already exist in the crop environment. Among many appropriate practices to control pests, CBC has been considered as a sustainable means and a less expensive alternatives to chemicals. It contains an introduction of non-crop plants as shelter habitat for providing natural enemies with food sources, overwintering or refuges shelters. As a small scale experiment of CBC, we tried to intercrop six kinds of floral plants (buckwheat, red clover, Agastache rugosa, Chrysanthemum indicum, Allium tuberosum, Lythrum anceps) with napa cabbage in order to attract some natural enemies, especially parasitic wasps that could be fed on them in the cabbage fields, which is a novel way for conservation of natural enemies, but none showed significant result. For the development of integrated pest management system by harmonizing biological and chemical control, we carried out evaluating toxicity of 30 pesticides to parasitoids and investigating effectiveness of traps. With leaf dipping method for adult and body dipping method for cocoons, 12 pesticides showed under 30% of toxicity being selected as safer by IOBC. Using sex-pheromone traps for attracting lepidopteran pests showed that DBM, CAW and CL occurred less than untreated fields; 67.5%, 70.6% and 44.0%, respectively. Also, yellow sticky traps could reduce some pests; 52% for flea beetle, 62% for cabbage sawfly and 41% for Phaedon brassicae. These results are expected to give basic information to develop conservation biological control of DBM with indigenous parasitoids in the cabbage fields on a large scale in the future. Before developing and distributing a promising pest control method, we should consider whether it can be compatible with other agricultural practices or various situations around fields.
        100.
        2014.04 구독 인증기관·개인회원 무료
        Apolygus spinolae (Meyer-Dür) (Heteroptera: Miridae) is an important pest of fruit and tea trees in Korea and Japan. Analyses of extracts of metathoracic scent glands revealed that those of female bugs contained hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal in a ratio of 20:100:7. The glands of males contained the same three compounds, but the ratio of the components was quite different, with hexyl butyrate being the most abundant. Field trapping tests with various blends of the synthetic compounds dispensed from high-density polyethylene tubes showed that (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal were essential for attraction of male A. spinolae, and catches with a wide range of ratios of these two compounds did not differ significantly. However, adding hexyl butyrate at 50% or more of the (E)-2-hexenyl butyrate to the binary blend strongly inhibited attraction of males. Trap catches increased with increasing amounts of a 10:1 blend of (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal from 0.011 to 11 mg loaded into the tube. Catches of males in traps baited with lures containing 1.1 mg of the binary blend were not significantly different from catches in traps baited with live virgin females.
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