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        검색결과 1,238

        644.
        2015.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effects of Nb doping on the crystal structure, microstructure, and dielectric ferroelectric and piezoelectric properties of (Bi0.5Na0.5)0.935Ba0.065Ti(1-x)NbxO3-0.01SrZrO3 (BNBTNb-SZ, with x = 0, 0.01 and 0.02) ceramics have been investigated. X-ray diffraction patterns revealed that all ceramics have a pure perovskite structure with tetragonal symmetry. The grain size of the ceramics slightly decreased and a change in grain morphology from square to spherical shape was observed in the Nb-doped samples. The maximum dielectric constant temperature (Tm) increases with increasing amount of Nb; however, ferroelectric-relaxor transition temperature (TF-R) and maximum dielectric constant (εm) values decrease gradually. Nb addition disrupted the polarization hysteresis loops of the BNBT-SZ ceramics by leading a reduction in the remnant polarization coercive field and piezoelectric constant.
        4,000원
        645.
        2015.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent decades, there has been an increasing interest in the use of carbon fiber reinforced plastic (CFRP) in aerospace, renewable energy and other industries, due to its low weight and relatively good mechanical properties compared with traditional metals. However, due to the high cost of petroleum-based precursors and their associated processing costs, CF remains a specialty product and as such has been limited to use in high-end aerospace, sporting goods, automotive, and specialist industrial applications. The high cost of CF is a problem in various applications and the use of CFRP has been impeded by the high cost of CF in various applications. This paper presents an overview of research related to the fabrication of low cost CF using polyethylene (PE) control technology, and identifies areas requiring additional research and development. It critically reviews the results of cross-linked PE control technology studies, and the development of promising control technologies, including acid, peroxide, radiation and silane cross-linking methods.
        6,100원
        646.
        2015.06 구독 인증기관 무료, 개인회원 유료
        This study aims to examine the effects of services marketing mix elements on customer equity through the customer experience in order to determine an optimal marketing mix strategy in the service industry. This paper utilizes confirmatory factor analysis and structural equation modeling (SEM) to analyze and confirm the proposed conceptual model. This study finds that the process, people, and physical evidence of the “7Ps” of the service marketing mix impart a positive and significant effect on the customer experience in the post-office setting. This result would help practitioners to create a service marketing strategy to differentiate their service from competitors in order to retain existing customers and attract new ones. It was also found that the customer experience is positively linked to customer equity. From the customer equity perspective, this study provides theoretical support that the customer experience, as one of the service operations management measurements, can be employed to measure service performance, which is also closely related to customer equity.
        4,000원
        647.
        2015.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        New lead-free piezoelectric ceramics 0.96[{Bi0.5 (Na0.84 K0.16)0.5}1-xLax(Ti1-y Nby)O3]-0.04SrTiO3 (BNKT-ST-LN, where x = y = 0.00 ≤ (x = y) ≤ 0.015) were synthesized using the conventional solid-state reaction method. Their crystal structure, microstructure, and electrical properties were investigated as a function of the La and Nb (LN) content. The X-ray diffraction patterns revealed the formation of a single-phase perovskite structure for all the LN-modified BNKT-ST ceramics in this study. The temperature dependence of the dielectric curves showed that the maximum dielectric constant temperature (Tm) shifted towards lower temperatures and the curves became more diffuse with an increasing LN content. At the optimum composition (LN 0.005), a maximum value of remnant polarization (33 C/cm2) with a relatively low coercive field (22 kV/cm) and high piezoelectric constant (215 pC/N) was observed. These results indicate that the LN co-modified BNKT-ST ceramic system is a promising candidate for lead-free piezoelectric materials.
        4,000원
        648.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.
        4,000원
        649.
        2015.06 구독 인증기관·개인회원 무료
        This study was designed to investigate luxury brand co-value creation. A mixed method approach was used to 1) identify encounter attributes of value co-creation, consumer value and brand value and 2) examine the relationships among encounter attributes, consumer value, brand value, and purchase intention to explain the process of value co-creation.
        650.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To date, most serodiagnostic methods for brucellosis screening are based on antibodies against lipopolysaccharides of Brucella spp. However, this approach has the drawback of yielding false-positive results due to cross-reactivity with lipopolysaccharides of other related pathogens, especially Yersinia enterocolitica O:9. In this study, Brucella abortus AspC was cloned and expressed by PCR amplification into a pCold TF expression system to obtain recombinant AspC (rAspC). The immunogenicity of rAspC was confirmed by western blotting of Brucella-positive bovine serum. rAspC-based ELISA was performed to determine whether rAspC could be used in the serodiagnosis of bovine brucellosis. rAspC reacted strongly with anti-Brucella antibodies in positive sera in the tube agglutination test (TAT), but did not show strong reaction with most negative samples. In particular, the average OD492 value at the highest TAT titer showed a 1.4-fold increase with respect to the cutoff value. The accuracy, specificity, and sensitivity of rAspC were 71.88%, 78.33%, and 68%, respectively. These findings suggest that rAspC might be valuable for the serological diagnosis of bovine brucellosis.
        4,000원
        651.
        2015.06 구독 인증기관 무료, 개인회원 유료
        The Maillard reaction is a complex reaction that occurs between carbonyl and amine groups during food pro-cessing and storage. In addition, it produces a large number of Maillard reaction products (MRPs), which have an importantrole in determining food characteristics including aroma, color, flavor, and texture. Importantly, recent studies have beenconducted that the Maillard reaction products and their ferments with lactic acid bacteria (LAB) induced specific biologicalcharacteristics including antimicrobial, antioxidative, and antihypertensive activities as well as improved their physiologicalfeatures such as the heat stability and emulsifying properties. Therefore, we described on new insights for enhanced physi-ologic and biologic functions of MRPs through LAB fermentation.
        4,000원
        654.
        2015.04 구독 인증기관·개인회원 무료
        This study was aimed at assessing the fumigant toxicity to adult Thrips palmi and Orius strigicollis of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour-phase toxicity bioassays. Results were compared with those for dichlorvos. Against adult T. palmi, linalool (LD50, 0.0055 mg cm–3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm–3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm–3), (±)-camphor (0.0097 mg cm–3) and 1,8-cineole (0.0167 mg cm–3). Moderate toxicity was produced by camphene, 3-carene, (–)-menthone, (+)-α-pinene, (+)-β-pinene, α-terpineol and (–)-α-thujone (0.0215–0.0388 mg cm–3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 ×10–10 mg cm–3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm–3. Based upon selective toxicity ratio (STR, O. strigicollis LD50/T. palmi LD50), the compounds described (STR, 0.7–>10.7) are more selective than dichlorvos (STR, 10.8×10–9 mg cm–3). Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
        655.
        2015.04 구독 인증기관·개인회원 무료
        The entomopathogenic fungus, Beauveria bassiana is widely used in integrated pest management (IPM), however its successful application is often limited by the little effort to explore its functions of unknown genes. In this work, egfp-expression cassette was randomly integrated into B. bassiana using Agrobacterium tumefaciensmediated transformation, and the general features of the mutants with unusual characteristics and the localization of the integrated genes were explored. To construct a transformation vector, egfp-expression cassette including gpdA promoter and trpC terminator was cut from pBARKS1-egfp using SacI and HindIII and integrated into pCAMBIA containing hygromycin B resistant hygR gene, designated as pCAMBIA-egfp. Transformed B. bassiana isolates were grown on quarter strength-Sabouraud dextrose agar containing 150 μg hygromycinB ml-1. Expression of egfp was investigated by RT-PCR and a fluorescent microscope (400×). Through the genome walking of the transformants using adaptor primers and gene specific primers, unique bands were detected on the egfp-expressing transformants, which were sequenced to figure out the flanking regions. This work provides a platform of methodology to figure out unknown functional genes of B .bassiana and possibly suggest an improved strategy to use the entomopathogen in IPM.
        656.
        2015.04 구독 인증기관·개인회원 무료
        An insect faunal survey was carried out to investigate insect community structure along the vegetation community to monitor insect species in forest ecosystem. We performed day and night collections from June to August along three vegetation communities of Is. Nam-hae in 2014: the first stand with Pinus thunbergii, the second P. thunbergii with Quercus serrata and the third P. thunbergii with various Quercus species. In total 2,259 individuals of 532 species, 99 families, 13 orders are identified. Cluster Analyses (CA) showed that all three vegetation communities were relatively similar between vegetation community types. According to indicator species analysis (ISA) result, nine significant indicator species were identified (p < 0.05); five species were found to be affected by the vegetation cluster and four species the month cluster.
        657.
        2015.04 구독 인증기관·개인회원 무료
        The species composition of the parasitoid complex and the degree of parasitism by each species were analyzed for Ivela auripes Butler (Lepidoptera, Lymantridae) populations in the increasing phase. Total of 2,177 eggs, larvae and pupae were collected and reared from the Gwangneung forest Pocheon-si, Korea. The most abundant parasitoids from each developmental stage were: a trichogrammatid wasp (Trichogramma kurosuae) from eggs, a braconid wasp (Cotesia melanoscela) from larvae, an ichneumonid wasp (Pimpla disparis) and a tachinid fly (Tachinidae sp.1), each from pupae. 19 other parasitoids, mostly hyperparasitoids, also occurred including Tachinidae sp.2, Pteromalidae sp.1, Ichneumonidae sp.3, and Apechthis capulifera. Illustrations and a list of the species parasitizing of I. auripes are provided.
        658.
        2015.04 구독 인증기관·개인회원 무료
        An oxidative fumigant is potent to kill insect pests infesting stored grains. Its oxidative activity generates reactive oxygen species (ROS), which has been considered to be a main insecticidal factor. Furthermore, the oxidative fumigant has cytotoxic effect to insect cell lines, but the cytotoxicity is abrogated by antioxidant treatment. This study aimed to extend the usefulness of the oxidative fumigant in terms of medical purpose against cancer cells. Five cancer cell lines HCT 116 (human colorectal), Lovo (human colorectal), SW480 (human colorectal), MDA-MB-231 (human breast), and MCF-7 (human breast) were tested to determine their susceptibility to the oxidative fumigant with reference to two insect cell lines (Sf9 and Hi-Five). All cancer cell lines were highly susceptible to the oxidative fumigant, compared to the insect cell lines. Interestingly, basal ROS levels of the cancer cell lines were much higher than the insect cell lines. Furthermore, the oxidative fumigant significantly increased the ROS levels in the cancer cells. Treatment of vitamin E as an antioxidant mitigated the cytotoxicity of the oxidative fumigant. Thus, the high susceptibility of cancer cells to the oxidative fumigant may be induced by their high inducible ROS production. This study also investigated the antiviral activity of the oxidative fumigant against insect and plant viruses. The oxidative fumigant significantly inactivated a baculovirus (dsDNA virus) by inhibiting polyhedral production in Sf9 cells. It also inactivated tobacco mosaic virus (ssRNA virus) by suppressing phytopathogenicity. These results support a broad effect of the oxidative fumigant, which can be applied to agricultural and medical purposes.
        659.
        2015.04 구독 인증기관·개인회원 무료
        The repellent activities of 33 plant extracts against Aedes albopictus were examined using a patch test for adult. The six plant extracts (Magnolia denudate, Dryopteris crassirhizoma, Cnidium officinale, Lindera obtusiloba, Magnolia kobus, and Houttuynia cordata) showed over 70% repellency activities to Ae. albopictus. The insecticidal activity of Curcuma longa against Ae. albopictus was also determined. C. longa hexane extraction showed 100% larvicidal activity at 1,000 ppm after treated 24 h. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel column chromatography. H1 fraction gave 100% mortality to Ae. albopictus at 100 ppm. H12 fraction was determined 87.8% larvicidal activity to Ae. albopictus at 50 ppm. Active constituent was analysed as the sesquiterpene, ar-turmerone (C15H20O) by GC and GC-MS. C. longa extract gave highly protection against mosquito bites. The hexane extraction showed complete protection at 10 mg over 6 h. In this study, the sesquiterpene from C. longa induced a protection time, repellency, landing time, and biting time against Ae. albopictus. These results suggest that the some plant extracts and C. longa have the potential to be used an eco-friendly materials for the control of mosquitoes.
        660.
        2015.04 구독 인증기관·개인회원 무료
        The melon and cotton aphid Aphis gossypii Glover (Hemiptera; Aphididae) is one of the most serious pests worldwide. We surveyed insecticide susceptibility in A. gossypii field populations to 12 insecticides to examine resistance ratios. The levels of insecticide resistance were extremely high, especially to neonicotinoids. One point mutation was found in the beta1 subunit loop D region of the nicotinic acetylcholine receptor (nAChR) of the imidacloprid-resistant strain. Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of imidacloprid had significant effects on the duration of phloem ingestion. In addition, higher doses of imidacloprid induced contact toxicity rather than inhibition of feeding behavior. Temperature and insecticide are two important factors that affect survival, reproduction and other physiological processes of insects. To determine interactions of temperature and insecticide treatment on susceptible and imidacloprid-resistant strains of A. gossypii, adults were exposed to three temperatures (17, 22, and 28℃) or combinations of three temperatures and imidacloprid (LC20), and the expression of several genes (heat shock protein 70, cuticle protein, cytochrome P450, and elongation factor) were analyzed. Additionally, the effect of electron beam irradiation on development, reproduction, and several gene expression of imidacloprid-resistant and -susceptible A. gossypii were compared.