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        검색결과 209

        101.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metallic porous materials have many interesting combinations of physical and geometrical properties with very low specific weight or high gas permeability. In this study, highly porous Cu foam is successfully fabricated by a slurry coating process. The Cu foam is fabricated specifically by changing the coating amount and the type of polyurethane foam used as a template. The processing parameters and pore characteristics are observed to identify the key parameters of the slurry coating process and the optimized morphological properties of the Cu foam. The pore characteristics of Cu foam are investigated by scanning electron micrographs and micro-CT analyzer, and air permeability of the Cu foam is measured by capillary flow porometer. We confirmed that the characteristics of Cu foam can be easily controlled in the slurry coating process by changing the microstructure, porosity, pore size, strut thickness, and the cell size. It can be considered that the fabricated Cu foams show tremendous promise for industrial application.
        4,000원
        102.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        경관해석에서 기호학은 매우 유용한 정보전달의 도구이며 도상기호(Icon), 지표(Index), 상징(Symbol)으로 구성되어 있다. 본 연구는 도상기호를 통해서 가로의 간판에서 표출되는 항구의 가로경관의 특성을 밝혀내는 것이다. 그리고 가로 의 간판에 나타난 기호적 경관의 특성을 통해서 경관을 직접 관리하거나 경관정책을 제시하는 이들에게 중요한 정보를 제공하는데 연구의 목적이 있다. 연구의 대상지는 경북 영덕군 강구항구이며, 연구방법은 가로의 간판에 나타난 도상기 호를 전수 조사하여 의미를 분석하였다. 연구의 결과는 다음과 같다. 강구항구의 가로 간판에 나타난 도상기호의 수는 모두 169개이며, 2차원 도상기호와 3차원 도상기호로 구성되어 있고 도상기호의 형태은 모두 34종이다. 그 중에서 가 장 많이 나타난 도상기호를 순서대로 보면 영덕대게 36.7%, 생선(회) 19.6%, 항구(배) 7.2%, 사람 얼굴 4.9% 찻잔 4..3%, 꽃 3.1% 등의 순서로 나타났다. 평면적 도상기호의 구성비는 전체 도상기호의 구성비와 유사하나 3차원 도상기 호의 빈도는 모두 15개이며, 유형은 영덕대게와 생선(회) 2종류로 영덕대게가 93%, 생선(회)이 7%다. 이러한 도상기호는 이 지역 특산물인 영덕대게와 생선(회)을 표현한 것으로 이런 현상은 매우 흥미 있는 것이다. 그리고 도상기호를 통한 강구항구의 가로경관의 특성은 특산물을 표현한 것이다. 따라서 가로경관에 3차원적 도상기호가 차지하는 비중이 절대적이다. 또한 강구항구 가로의 도상기호를 유형화하면 동식물, 자연, 음식물, 생활서비스, 추상적 유형 등의 5가지 유형으로 구분되었다. 주로 관광객들을 위한 가로와 인근 주민들을 위한 가로에서 표출되는 도상기호가 다른 양상으로 표출되는 특징이 있다. 그리고 가로의 도상기호는 해당 지역 주민들의 삶을 한마디로 표현한 것으로 보인다.
        4,000원
        103.
        2014.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the development of solar flux receivers operating at 2.8 GHz to monitor solar radio activity. Radio waves from the sun are amplified, filtered, and then transmitted to a power meter sensor without frequency down-conversion. To measure solar flux, a calibration scheme is designed with a noise source, an ambient load, and a hot load at 100℃. The receiver is attached to a 1.8 m parabolic antenna in Icheon, owned by National Radio Research Agency, and observation is being conducted during day time on a daily basis. We compare the solar fluxes measured for last seven months with solar fluxes obtained by DRAO in Penticton, Canada, and by the Hiraiso solar observatory in Japan, and finally establish equations to convert observed flux to the so-called Penticton flux with an accuracy better than 3.2 sfu.
        4,000원
        104.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of bacterial inoculation (Lactobacillus plantarum) and cutting height on the chemical composition, fermentation characteristics and in vitro dry matter digestibility (IVDMD) in whole crop barley silage. Barley forage (Youngyang hybrid) was harvested at about 27% of dry matter (DM) level at two different cutting height (5 vs. 15 cm). And it was chopped to 5 cm length and treated with or without L. plantarum. Four replicates of each treatment were ensiled into 10 L mini silo (3 kg) for 100 days. After 100 days, bacterial inoculation decreased (p=0.001) DM content, while increased cutting height increased (p=0.002) DM in uninoculated silage. Crude protein (CP) concentration was decreased by increasing height in uninoculated silage (8.84 vs. 8.16) but increased in inoculated silage (8.19 vs. 8.99). Both neutral detergent fiber (NDF) (p<0.011) and acid detergent fiber (ADF) (p<0.004) were decreased by increasing cutting height of forage at harvest. The IVDMD and ammonia-N was increased (p=0.001) by increasing cutting height and inoculation, respectively. Lactic acid bacteria (LAB) was increased (p=0.002) in inoculated silage, but yeast count was decreased (p=0.026) in uninoculated silages. It is concluded that increased cutting height of forage at harvest could be useful to make a fibrous portion with increase of dry matter digestibility of silages.
        4,000원
        105.
        2014.07 구독 인증기관·개인회원 무료
        Explicit environmental attitude measures tend to produce strong socially desirable responses (Bruni & Schultz, 2010; Milfont & Duckitt, 2010; Stern & Dietz, 1994) and fail to capture more than what participants consciously recall (e.g., explicit belief, past behavior, Dunlap, Van Liere, Mertig, Jones, 2000; Schultz, Shriver, Tabanico, & Khazian, 2004). A number of studies have highlighted the popularity of environmental issues in common discourse in various countries, which leads individuals to eagerly express pro-environmental explicit attitudes (Dunlap, 1998; Leiserowitz, 2005; Meijers & Stapel, 2011). Therefore, an explicit measure of environmental attitudes would hardly be an unbiased indicator of prior knowledge and experience when testing the effect of subtle feeling on judgments: although a participant explicitly reports favorable attitudes toward environment or related issues, it does not necessarily mean that she or he has knowledge and experience to hinder the regulatory fit effects. Using the Implicit Association Test, we examined whether the extent to which individuals are implicitly biased toward (or against) sustainability moderates the regulatory focus by construal level interaction. Scores from the indirect measure of attitudes served as the indicator of the strength of associations between the concept of sustainability and evaluations that may result form its frequent pairing with desirable consumption patterns or repeated exposure to persuasive messages promoting sustainability. Specifically, we showed that the regulatory focus – construal level fit effect will be greater among individuals who have not formed significant associations about sustainability since these individuals are more likely to rely on feeling right from regulatory fit rather than using prior experience or knowledge.
        106.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the wakes behind a square cylinder were simulated using two kinds of different turbulence models for the eddy viscosity concept such as the zero- and the one-equation model in which the former is the mixing length model and the latter is the k-equation model. For comparison between numerical and analytical solutions, we employed three skill assessments: the correlation coefficient(r) for the similarity of the wake shape, the error of maximum velocity difference(EMVD) for the accuracy of wake velocity and the ratio of drag coefficient(RDC) for the pressure distribution around the structure. On the basis of the numerical results, the feasibility of each model for wake simulation was discussed and a suitable value for the empirical constant was suggested in these turbulence models. The zero-equation model, known as the simplest turbulence model, overestimated the EMVD and its absolute mean error(AME) for r, EMVD and RDC was ranging from 20.3 % to 56.3 % for all test. But the AME by the one-equation model was ranging from 3.4 % to 19.9 %. The predicted values of the one-equation model substantially agreed with the analytical solutions at the empirical mixing length scale L=0.6b1/2 with the AME of 3.4 %. Therefore it was concluded that the one-equation model was suitable for the wake simulation behind a square cylinder when the empirical constant for eddy viscosity would be properly chosen.
        4,200원
        107.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, advancing technology and growing interest in neuromarketing and neurobranding have led to foundational research that facilitates a better understanding of consumers’ affective responses and unconscious information processing. However, the areas of aesthetics and design have remained largely unaffected by such advances and implications. The purpose of this study is to present a systematic review of the neuroscientific evidence aimed at sensible design for design and marketing researchers interested in exploring neuroaesthetics, an interdisciplinary area by nature. Sciencedirect, EBSCO, and the Google Scholar database were searched in February 2014 to select and review previous studies of aesthetics involving neuroscience. Twenty-eight studies were reviewed and divided into two categories: reward system and emotion. In addition to discussions on previous approaches, future research directions focusing on the process of aesthetic judgments (e.g., design elements, marketing stimuli) are proposed.
        4,000원
        108.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ampelopsis brevipedunculata, a porcelain berry that is a kind of Korean domestic wild berry (Viticeae), has been known to be resistant to diseases and insects. A total of 2,622 unigenes containing 912 contigs and 1,710 singletons were obtained by sequencing 5,839 expressed sequence tag (EST) clones derived from the cDNA library of wild grape, A. brevipedunculata. In the gene ontology analysis, 1,175 genes related to biological process, 1,516 genes related to molecular function, and 1,413 ones related to cell components were annotated. Among the genes showing molecular function, 17 clones were classified into defense-related genes, and 102 were known to be related with responses to stress in plants. Domains, such as leucine-rich repeat, Serine/threonine protein kinase-related, WD40 repeat, EF-hand calcium-binding, pentatricopeptide repeat, and pathogenesis-related transcriptional factor were highly expressed. Genes encoding defense related proteins, such as chitinase, catalase, protein-serine/threonine kinases, were also clustered into an abundant group in cDNAs from A. brevipedunculata. Approximately, 80 simple sequence repeats with 2~5 nucleotides were detected in the cDNAs of A. brevipedunculata. These data could provide useful information for the genetic analysis of wild grapevines and in programs for breeding grape cultivars.
        4,500원
        109.
        2013.10 구독 인증기관 무료, 개인회원 유료
        With the rapid development of the rural economy and vigorous promotion of energy-saving technologies, it is found through a field investigation that the new rural housing in the northeast of China shows new changes on green, energy-efficiency, health, comfort and beauty. The new rural housing mainly applied the technologies of composite energy-saving wall, double or three layers of glass energy saving windows and the roof benzene board insulation, heated in winter by Kang with the fuel of straw, corn stalks and other bio energy, which brings prominent energy-saving effect and the improved indoor environment significantly. The only or main function of the Kang is no longer the heating facilities in winter, but to play its unique benefits of comfort and health for sleep as a bed. the highlights of cultural traditions and customs in Cold rural area, the changes of the Kang are smaller and more exquisite. In the future, northeast rural housing should integrate the technolgies of residential structures, materials and kang further to promote rural sustainable development of society, economy.
        4,000원
        110.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study of oxidation kinetic of Fe-36Ni alloy has been investigated using thermogravimetric apparatus (TGA) in an attempt to define the basic mechanism over a range of temperature of 400 to and finally to fabricate its powder. The oxidation rate was increased with increasing temperature and oxidation behavior of the alloy followed a parabolic rate law at elevated temperature. Temperature dependence of the reaction rate was determined with Arrhenius-type equation and activation energy was calculated to be 106.49 kJ/mol. Based on the kinetic data and micro-structure examination, oxidation mechanism was revealed that iron ions and electrons might migrate outward along grain boundaries and oxygen anion diffused inward through a spinel structure, .
        4,000원
        111.
        2012.10 구독 인증기관 무료, 개인회원 유료
        절삭가공에서 가공양의 과다 및 가공부위와 형상은 절삭저항에 의한 절삭 열을 발생시키고 이 열로 인해 가공품의 정밀도에 변형을 가져온다. 절삭가공 시 공작기계에서 발생하는 오차의 40~70%는 열 변형 오차에 의해서 발생한다. 박판 박판 블레이드는 절삭 열을 받아들이는 공작물의 두께가 얇기 때문에 열 변형 오차에 쉽게 정밀도가 저하된다. 이때에 뒤틀림이 발생하면 정밀도는 매우 큰 오차를 포함하게 된다. 본 연구의 목적은 박판의 절삭가공에서 열 변형이 발생함을 예측하고 발생 부위에 따라 어떤 변형이 발생하는 지를 측정하여 파악하고자 한다. 또한, 측정된 결과를 통해 열 변형을 최소화하는 가공방법을 제시한다.
        3,000원
        112.
        2012.08 구독 인증기관 무료, 개인회원 유료
        With the rapid development of the rural economy and vigorous promotion of energy-saving technologies, it is found through a field investigation that the new rural housing in the northeast of China shows new changes on green, energy-efficiency, health, comfort and beauty. The new rural housing mainly applied the technologies of composite energy-saving wall, double or three layers of glass energy saving windows and the roof benzene board insulation,heated in winter by Kang with the fuel of straw, corn stalks and other bio energy, which brings prominent energy-saving effect and the improved indoor environment significantly. The only or main function of the Kang is no longer the heating facilities in winter, but to play its unique benefits of comfort and health for sleep as a bed. the highlights of cultural traditions and customs in Cold rural area, the changes of the Kang are smaller and more exquisite. In the future, northeast rural housing should integrate the technolgies of residential structures, materials and kang further to promote rural sustainable development of society, economy.
        4,000원
        113.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est2R) was 2,120 bp in length, encoding a protein of 516 amino acid residues with a calculated molecular weight of 57,286 Da. The molecular weight of the enzyme was estimated to be 57,000 Da by SDS-PAGE. Est2R shared 35.6% amino acid identity with esterase (CAH19079) of uncultured prokaryote. The Est2R was most active at 20-40°C, and showed optimum at 30°C and pH 8.0. The most activity of Est2R for the different chain length of p-nitrophenyl ester group as substrate was p-nitrophenyl acetate. Moreover, the enzyme was found to be most active without organic solvent, followed by 98% active with ethanol, and the enzyme activity was highly affected by the acetonitrile. The enzyme was significantly inhibited by Zn2+ but stimulated by Ca2+. So, novel esterase gene est2R is likely to obtain from cow rumen metagenome and supposed to use for industrial purpose.
        4,000원
        114.
        2012.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A carboxymethyl cellulase gene, cel5B, was cloned, sequenced, and expressed in Escherichia coli. pRCS20 in E. coli was identified from metagenomic cosmid library of cow rumen for cellulase activity on a carboxymethyl cellulose agar plates. Cosmid clone (RCS20) was partially digested with Sau3AI, ligated into BamHI site of pBluescript II SK+ vector, and transformed into E. coli DH5α. The insert DNA of 1.3 kb was obtained, designated cel5B, which has the activity of hydrolyzation of CMC. The cel5B gene had an open reading frame (ORF) of 1,059 bp encoding 352 amino acids with a signal peptide of 48 amino acids and the conserved region, VIYEIYNEPL, belongs to the glycosyl hydrolase family 5. The molecular mass of Cel5B protein expressed from E. coli DH5α exhibited to be about 34 kDa by CMC-SDS-PAGE. The optimal pH was 8.0, and the optimal temperature was about 50℃ for its enzymatic activity.
        4,000원
        115.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        머루(Vitis coignetiae)는 국내에 자생하는 야생종 포도의 한 종류로서, 포도 새눈무늬병에 저항성이다. 내병성 포도 육종에 활용할 유용한 육종소재를 개발하고자 머루의 잎과 과실로부터 cDNA libraray를 제작하였다. 머루의 cDNA library의 총 5,760개의 EST 클론을 분석하여 676개의 contig와 2,306개의 singleton을 분리하여 총 2,982개의 unigene을 분리하였다. NCBI 데이터베이스의 BLAST를 통한 상동성을 검색한 결과, 2,241개의 클론이 기능이 알려진 유전자이었고, 그 중에서 1,442개는 생물학적인 대사에 관여하고 836개는 세포구성물과 관련이 있었다. EST와 contig의 평균 크기는 각각 702bp와 757bp이었다. 포도새눈무늬병균에 감염된 머루 cDNA library로부터 Proline-rich cell wall protein, thaumatin-like protein, class IV chitinase, and pathogenesis-related (PR) protein 10 등의 다양한 방어관련 유전자와 광합성관련유전자 및 수분스트레스 저항성 관련유전자가 많이 검출되었다. 본 연구를 통해 얻어진 머루의 EST 자료는 포도의 새로운 유전자원에 관한 연구 및 내병성 포도 신품종 육종 프로그램에 기본자료로 유용하게 활용될 것이다.
        4,000원
        116.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Zinc oxide nanoparticles (nZnO) are used in a various range, including ceramic manufacture, photocatalysis, UV filters, and the food industry. However, little is known about the effects of micro- and nano-particles during mouse embryo organogenesis. To determine whether ZnO affects size-dependent anomalies during embryonic organogenesis, mouse embryos were cultured for two days with 300 ug/ml micro ZnO (mZnO;80±25 μm) and nZnO (< 100 nm) and the developmental changes were then investigated. Quantity of Zn by inductively coupled plasma mass spectrometry analysis, and expression patterns of various antioxidant enzymes in the embryos were investigated. Embryos exposed to mZnO or nZnO exhibited severe retardation of growth and development. In embryos exposed to mZnO and nZnO, yolk sac diameter, crown-rump length, and head length were significantly diminished. The morphological parameters, including yolk sac circulation, allantois, flexion, heart, hindbrain, midbrain, forebrain, otic system, optic system, branchial bars, maxillary process, mandibular process, olfactory system, caudal neural tube, forelimb, hindlimb, and somites in mZnO and nZnO-treated groups were significantly decreased. Zn absorption of the nZnO-treated group was significantly higher than that of the mZnO-treated group. Significantly decreased levels of CuZn-SOD, Mn-SOD, cGPx, and PHGPx mRNA were observed in the ZnO-treated group. In addition, antioxidant enzyme mRNA expressions of the nZnO group were significantly diminished, less than those of the mZnO treated group. These findings indicate that 300 ug/ml ZnO showed abnormality and nZnO may have a more severe effect than mZnO in developing embryos.
        4,000원
        117.
        2011.03 구독 인증기관 무료, 개인회원 유료
        Neurotoxicity and oxidative injury induced by glutamate cause neuronal degeneration related to various central nervous system diseases. Resveratrol, a polyphenolic compound, is known to have antioxidative and anti-inflammatory effects. The aim of this study was to investigate the question of whether resveratrol has a neuroprotective effect against glutamate-induced toxicity in cultured cortical neurons. Following exposure to glutamate for 15 min, cortical neurons originating from ICR mouse fetuses on embryonic days 15-16 were then treated with resveratrol for 24 h in the post-treatment paradigm. Glutamate induced a significant reduction in cell viability; however, resveratrol induced a significant increase in cell viability. Glutamate induced generation of ROS and apoptotic neuronal death; however, these were decreased by exposure to resveratrol. mRNA expression in antioxidant enzymes, cytoplasmic glutathione peroxidase, copper/zinc superoxide dismutase (SOD), and manganese SOD, and anti-apoptotic regulator Bcl-xL were decreased by exposure to glutamate, however, exposure to resveratrol resulted in a significant increase in their mRNA levels. In addition, mRNA expression of pro-inflammatory cytokines, interleukin-1β and tumor necosis factor-α, was increased by glutamate insult, but significantly reduced by resveratrol. These findings indicate that resveratrol is neuroprotective against glutamate-induced toxicity, suggesting a useful therapeutic application in treatment of neurodegenerative disorders.
        4,200원
        118.
        2010.12 구독 인증기관 무료, 개인회원 유료
        Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a unique antioxidant enzyme involved in reduction of peroxidized phospholipids within biomembranes. To investigate the expression pattern of the PHGPx gene during fetal development, in situ hybridization analyses were performed using mouse FITC-labeled PHGPx cRNA probes in fetal tissues on embryonic days (Ed) 13.5-18.5. During these periods, PHGPx mRNA appeared in the developing telencephalon, diencephalon, spinal cord, and spinal ganglion. In particular, PHGPx mRNA was strongly expressed in pyramidal cells of the cerebral cortex. On Eds 17.5-18.5, PHGPx mRNA was detected in various tissues including liver, intestinal villi and crypt, pancreas, lung, and olfactory epithelium of the nasal cavity. In addition, PHGPx mRNA was highly expressed in the inner ear on Eds 14.5-18.5, brown fat on Ed 17.5, and adrenal gland on Ed 18.5. It is conceivable that PHGPx may act as an important antioxidant against fetal oxidative stress during mouse organogenesis.
        4,000원
        119.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Animal crude drugs (natural medicines derived from animal organs) have been widely used in various Chinese medicine for the therapeutic effects and for enhancement of immunologic functions. We found the specific identification methods using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses for mitochondrial DNA (mt DNA) in order to discriminate between the animal species and organs as well as the placenta of humans. Species-specific PCR bands of D-loop mt DNA for equine, bovine, porcine, and human were 133 bp, 137 bp, 231 bp, and 240 bp, respectively. Porcine organs were identified using restriction enzyme, HphI cut into two subfragments, 36 bp and 195 bp bands in the heart, spleen, and liver, except for kidney. The heart and liver of porcine were identified using restriction enzyme, SpeI cut into two subfragments, 84 bp and 147 bp bands, except for kidney and spleen. Bovine organs were cut into 68 bp and 69 bp bands in the liver, kidney, and spleen using NalIV, except heart and placenta. Placentas of bovine and humans were easily identified using each primer. Our results suggest that sequencing of mt DNA and its PCR-RFLP methods are useful for identification and discrimination of inter- and intra-specific variations in equine, bovine, porcine, and human by routine analysis.
        4,000원
        120.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Wrinkles are an outward sign of cutaneous aging appearing preferentially on ultraviolet B (UVB)-exposed areas. The anti-wrinkle effects of herbal extracts were investigated in an animal model. Female albino hairless mice (HR/ICR) were randomly allocated to the control group (non-irradiated vehicle), positive control group (UVB irradiated-vehicle), and two herbal extract mixture groups (HE-1 and HE-2). HE-1 included Glycyrrhizae radix, Rhei Rhizoma, Cornus officinalis, and Sesami semeni, and HE-2 included Swertia pseudo-chinensis, Sophora flavescens, Scutellaria baicalensis, and Salvia miltiorrhiza. The herbal extract mixtures were pre-treated dorsally with 0.2 ml per individual five times per week for four weeks prior to the start of UVB irradiation. At the fifth week, the animals were exposed to UVB irradiation for a subsequent eight weeks, three times per week. The intensity of irradiation showed a gradual increase, from 30 mJ/cm 2 to 240 mJ/cm2 (1 MED: 60 mJ/cm2 ). Dorsal skin samples were stained with H&E in order to examine the epidermal thickness. In addition, Masson-Trichrome staining was performed for determination of the amount of collagen fiber. Treatments with HE-1&2 resulted in an increase in the amount of collagen fiber, a better appearance, and fewer wrinkles, compared with the positive control. As determined by hydroxyproline assay, treatments with HE-1&2 led to a significant increase in the amount of collagen, compared with the positive control group (p<0.05). Chronic UVB irradiation to skin of hairless mice resulted in an increase in expression of matrix metalloproteinase-1 (MMP-1), however, treatments with HE-1&2 tended to decrease the expression of MMP-1. These results indicate that the herbal extracts used in this study have a preventive effect on UVB-induced wrinkle formation in a hairless mouse model, due in part to inhibition of MMP-1 expression and increment of collagen amount.
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