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        검색결과 2,998

        1531.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, two kinds of advanced powder processing techniques Metal Injection Molding (MIM) and Direct Laser Forming (DLF) are introduced to fabricate complex shaped Ti alloy parts which are widely used for med- ical and aerospace applications. The MIM process is used to strengthen Ti-6Al-4V alloy compacts by addition of fine Mo, Fe or Cr powders. Enhanced tensile strength of 1030 MPa with 15.1% elongation was obtained by an addition of 4 mass%Cr because of the microstructural modification and also the solution strengthening in beta phase. However, their fatigue strength was lower compared to wrought materials, but was improved by HIP. Subsequently, the effect of feed- ing layer height (FLH) on the characteristics of the DLF compacts was investigated. In the case of 100 µm FLH, sur- face roughness was improved and nearly full density (99.8%) was obtained. Also, tensile strength of 1080 MPa was obtained, which is higher than the ASTM value.
        4,000원
        1532.
        2013.10 구독 인증기관 무료, 개인회원 유료
        Hanok recently is getting attention by Korean wave and the eco-friendly construction. However it has the not a few . weak points to live in modem and been recognized as a big problem such as efficiency problem, hight cost to construct and maintenance difficulty to be solved. The solution are the modularity and weight lightening of Hanok but the roof is one of the most difficult parts of it, the roofrepresents the beauty of Hanok with graceful catenary line, filling timber and soil should be improved to the modem materials and construction methods as an alternative. As the result, this study conceives the improvement figuring out the problem and the case study review as well as suggests the valuation of feasible plan and the potential for modularity by application of the actual field. The roof is consisted of the framework as the constructable role on the upper part of roof board, the insulation and air layer as well as additional roof board should be installed to make easy the roof construction and attach the vapor permeability water proofed paper. Accordingly, Additional rafter, Diaphragm board and Panel can be used as the alternatives. and this reports the possibility of workability, modularity applied in the field. The results of this study are expected to improve the efficiency of the waterproofing of roofs, insulation, maintenance, etc and so on contribute to the pervasiveness of the hanok.
        4,900원
        1533.
        2013.10 구독 인증기관 무료, 개인회원 유료
        Hanok is the key technology of the 21st century buzzword, as 'healthy homes' and 'eco-friendly' and to meet the demands for the safety and comfort of the human body in space, the possibility is getting attention again. Hanok worth from the perspective of brand marketing, pay raises, and maintain it throughout the whole life cycle of the value based on continuous activities. The systematization, and the efficiency of the way should be carried out to maintain to achieve the purpose. This presented study is divided into three stages, the consideration of Hanok Characteristics, maintenance manual written case analysis and Hanok written direction of the manual and take advantage of the possibilities. Firstly, for the consideration of Hanok natures, we study the Hanok maintenance characteristics to analyze the use of materials and construct method based on the result of 'Hanok technology development'. Secondly, we grasp the element which can be applied on the maintenance manual, analyze the maintenance manual contents and the written direction. Lastly, proposed step of written direction, we suggest the direction of Hanok manual writing based on identified elements. "Hanok Maintenance Manual," has two dictionary definitions that one explains easily know the use and the features of Hanok as well as another describes specific knowledge needed to perform maintenance work on how to organize a 'guide'. The result as above is based on the understanding of the objective and in the pursuit of the only purpose, which express the inherent meaning and configuration on the manual, in helping the readers understand techniques of expression and the cumulativee necessity of proven cases
        4,500원
        1534.
        2013.10 구독 인증기관·개인회원 무료
        Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 19 acaricides to determine its suitability for residual contact vial bioassay (RCV) by using PyriF strain as a reference. Twelve acaricides (Amitraz Abamectin, Bifenthrin, Bifenazate, Chlorfenapyr, Cyenopyrafen, Cyflumetofen, Endosulfan, Fenothiocarb, Monocrotophos, Omethoate and Tebufenpyrad) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Dicofol, Etoxazole, Fenbutatin oxide, Fenpyroxymate, Flufenoxuron, Spiromesifen and Pyridaben) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to 12 acaricides were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.
        1535.
        2013.10 구독 인증기관·개인회원 무료
        Insects possess two distinct acetylcholinesterases (AChE1 vs. AChE2), which are encoded by two paralogous loci originated from duplication. Kinetic analyses of several insect AChEs revealed that both AChE1 and AChE2 retain common catalytic properties of AChE but subtle kinetic differences also exist between these two AChEs. To understand how selection pressure has shaped the protein structure of AChEs and affected their function during evolution, we measured and compared the nucleotide diversity (Pi) and amino acid site-specific selection pressure between AChE1 and AChE2 from various insects. Highly conserved were the majority of the amino acid residues involved in forming the essential domains, including peripheral anionic site (PAS), and little differences were revealed between AChE1 and AChE2, suggesting the presence of strong purifying selection pressure over these essential residues. Interestingly, the EF-hand like motif was mostly found in the AChE1 lineage but not in AChE2. In addition, a unique amino acid difference in the PAS (D72 vs. Y72) was highly conserved between AChE1 and AChE2. Three-dimensional modeling of insect AChEs by particularly focusing on the PAS revealed that a subtle but consistent structural alteration in the active site topology was caused by the PAS amino acid substitution. Taken together, despite the long evolutionary history and low overall sequence similarity, both insect AChE1 and AChE2 still share a extremely high degree of structural and functional conservation, indicative of a strong purifying selection pressure. Nevertheless, only a small change in the PAS, appears to be associated with a local but significant alteration of AChE2 structure, which in turn drives the functional differentiation of AChE.
        1536.
        2013.10 구독 인증기관·개인회원 무료
        Acetylcholinesterase (AChE) plays a pivotal role in the synaptic transmission in the cholinergic nervous system of most animals, including insects. Insects have two different ace (ace1 and ace2) loci that encode two distinct AChEs (AChE1 and AChE2), which were originated by duplication events long before the radiation of insects. However, little is known about when the ace duplication occurred and how each duplicated ace locus has evolved to retain the original functions. In this study, we conducted phylogenetic analysis for cholinesterase genes from all the lower animals with their genome sequenced together with all known arthropod ace1 and ace2, including those from a number of insects that were newly cloned. Among several independent duplications in lower animal lineages, one duplication event found in platyhelminthes appeared to be the direct origin of arthropod ace1 and ace2. Comparison of the evolutionary distance (d) of two aces from different insect groups relative to those from common ancestors revealed that ace1 has evolved with a significantly slower rate compared to ace2, suggesting that the ace1 lineage has maintained relatively more essential functions following duplication. When the dN/dS ratio was compared between ace1 and ace2 within different insect orders, ace2 was determined to have received relatively more positive selection pressure in Diptera and Hymenoptera whereas the same was true for ace1 in Coleoptera, Hemiptera and Lepidoptera. Along with the relatively more decreased d value for ace2, such an increased dN/dS ratio for ace2 in Diptera and Hymenoptera implied the incidence of functional transition of ace1 to ace2. Our findings should provide with new insights into the evolution of two insect AChEs: when they were generated and how they retain and gain the neuronal functions.
        1537.
        2013.10 구독 인증기관·개인회원 무료
        F. occidentalis causes to decrease the yield of chrysanthemum flower economically because it is the major crop pest injuring the flower directly at flowering period in chrysanthemum artificial houses. The control of it with chemicals is very difficult because the resistance of it to chemicals is so high. F. occidentalis began to occur at early-May and increased rapidly mid-May after in standard chrysanthemum artificial houses, Yesan, Chungcheongnam-do. In case of a farm, the density of it increased continuously in spite of chemical control . The times of chemical control to depress the density of it was 6 or 7th for cultivation period of chrysanthemum. We put the flowering yellow pot-mum already (trap plant attracting F. occidentalis) in standard chrysanthemum PVC-houses and set the yellow sticky cards up at an interval of 5m from trap plant(TP). The more yellow sticky trap near to trap plant, the more F. occidentalis was attracted to yellow sticky trap. TP was more attractive to adult F. occidentalis up to distances of 10m. The numbers of it attracted to yellow sticky traps at different distance from TP was not different significantly when standard chrysanthemum bloomed. We put the TP in standard chrysanthumum PVC-house at an distance of 20m and released the natural enemies (Orius laevigatus) on TP at 3 times, an interval of 7 days. And then we set yellow sticky traps up at an distance of 5m from TP and compared the plot with TP+natural enemy(NE) to the plot without them. The density of F. occidentalis was rather lower at TP+NE plot than the plot without at the formative period of flower bud of standard chrysanthemum. Therefore, The yellow flowering chrysanthemum possesses great value of TP attracting F. occidentalis in chrysanthumum PVC-house up to flowering period of cultivating chrysanthemum, and if it is used with natural enemy and chemicals simultaneously, farmers can minimize the quantity of chemicals used.
        1538.
        2013.10 구독 인증기관·개인회원 무료
        Abamectin, soil-born bacterial acaricides, has been intensively used to control Tetranychus urticae. Target site insensitivity and enhanced activity of detoxification enzymes have been considered as major resistance mechanisms. Here, we identified the differentially expressed genes after feeding sublethal dose of abamectin for 36 h by RNA-seq analysis. About 4.9 million reads (± 2,630,543 reads) were assembled into T. urticae. Among a total of 75 genes showing differential transcription, 18 and 14 genes were up- and down-regulated over two fold ratio, respectively. In the validation analysis, the calculated fold change of each genes between RNA-seq and qPCR were moderately correlated (r 2 = 0.661). A cuticular protein was shown as the highest up-regulated gene (192.3-fold) and a chitinase was revealed to be the highest down-regulated (-16.4-fold). Further study would be necessary to validate their roles in T. urticae adaptation to acaricides.
        1539.
        2013.10 구독 인증기관·개인회원 무료
        Most insects possess two different acetylcholinesterases (AChEs) (i.e., AChE1 and AChE2). It has been recently reported that both AChEs are equally active in a damselfly species, providing a unique example of the incomplete specialization of one AChE function after duplication (Kim and Lee, 2013). In this study, we investigated the tissue distribution patterns and the molecular and inhibitory properties of two AChEs (i.e., VgAChE1 and VgAChE2) from the Vestalis gracilis damselfly. VgAChEs exhibited almost identical catalytic activity and were expressed in the central nervous system (CNS). The most predominant molecular form of both VgAChEs was a disulfide-bridged dimer, which is associated with the cell membrane via a glycosylphosphatidylinositol anchor. In an inhibition assay, however, VgAChE1 and VgAChE2 exhibited different sensitivities to organophosphate and carbamate insecticides depending on the structure of the inhibitors. These findings suggest that both VgAChEs have neuronal functions. In addition, soluble monomeric and cleaved molecular forms were detected in both the CNS and peripheral nervous system tissues by an AChE2-specific antibody, implying that VgAChE2 probably shares both neuronal and non-neuronal physiological functions in V. gracilis. Our results support the notion that both VgAChEs, paralogous of each other, are involved in synaptic transmission, with VgAChE2 being in the early stage of acquiring non-neuronal functions.
        1540.
        2013.09 구독 인증기관·개인회원 무료
        The oil sands are loose sand or partially consolidated sandstone containing naturally occurring mixtures of sand, clay, and water, saturated with a dense and viscous from of bitumen. Natural bitumen deposits are found in large quantities in Alberta and Utah area. Nevertheless of its environmental issues, a large-scale commercial oil sands industry is expected to increase in coming decades.(1) The present paper focuses on physico-chemical analysis of two different types of bitumens. These bitumen samples were chosen based on: the original source (oil sand and crude petroleum), and mode of process. The aim of this study is to determine both the manufacturing effect on chemical species and the chemical organization as a function of the type of bitumen sample. In order to obtain information on bitumen chemistry, elemental analysis (C, H, N, S, and O), heavy metal (Ni, V) concentrations, IATROSCAN chromatography (thin layer chromatography-flame ionization detection), FTIR spectroscopy, and NMR spectroscopy (1H NMR,13C NMR)haveallbeenused.The characterization includes information about the major compound types (saturates, aromatics, resins and asphaltenes) which can be compared with similar data for other bitumens, more importantly, can be correlated with data from petroleum samples for which refining characteristics are known. Examination of oil sand asphalt showed that it differed significantly from representative petroleum residues, principally in their nonhydrocarbon content and aromatic compounds. When possible, properties and composition were related to recovery and refining processes. This information is important because of the effects that composition has on recovery and processing reactions.