• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.28-28
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• 2003

Viable interspecific hybrids between yellowtail flounder (Pleuronectes ferrugineus, Store.) and winter flounder (Pleuronectes americanus, Walbaum) were produced by artificial insemination of yellowtail flounder eggs with winter flounder sperm. However, mean fertilization rate, hatching success and early survival up to 3 weeks post hatch were significantly lower than those of parental pure cross controls (P<0.01). Overall, cytogenetic traits (karyological analysis and estimation of cellular DNA contents using flow cytometry) of hybrid flounder were intermediate between the two parental species. Microsatellite assay was used to distinguish the parental genomes in the hybrids; in most cases, one allele was specific to each of the parents. Morphometrics assessed by body proportions indicated that hybrids generally displayed a morphology intermediate between the maternal and paternal species. Interspecific hybrids exhibited abnormal and retarded gonad development in both sexes based on histological analysis of gonads from adult fish. The sterility of the hybrids presents a significant advantage for their use in aquaculture, as potential escapees would not be capable of reproducing in the wild and contaminating natural stocks.

• 한국실내디자인학회논문집
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• 제22권6호
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• pp.68-78
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• 2013

The purpose of this study is to investigate Seonyudo Park and Kkummaru in terms of haptic space. This is an attempt to escape from the limits of optical space that identifies the space with abstract concepts. Haptic perception of the space refers to feeling the space with all the senses through non-hierarchical interactions. Time of the haptic space is revealed by Deleuze's crystalline description and Bergson's pure recollection that is not useful to identify objects. According to two concepts, the running present forks into the past and the future, and the nature of time appears at the point of indiscernibility in which the past, present, and future coexist. Thought on time about the architecture provides a valid point of view to understand the relationship of visitor's sensory experience of space, recollection, and emotion. In this respect, it can be said that Joh sung-yong's two works explored for new areas of architectural experience by building up the potential image of the subject which is placed in the human memory. And then this study shows that two works recover the relationship between the past and the present so that they give an opportunity to consider the meaning of time in the architecture.

• 전기화학회지
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• 제17권1호
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• pp.13-17
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• 2014

The $TiO_2$ nanotube/Ti electrode are used as an anode in thin-film lithium microbatteries is known to have high oxidation-reduction potential of 1.8 V (vs. $Li/Li^+$). It can prevent from dendrite growth of lithium during charging. The $TiO_2$ nanotube/Ti electrode was prepared by anodizing at constant voltages for thin-film lithium microbatteries. The capacities of $TiO_2$ nanotube/Ti anode prepared by anodizing at 10 V, 20 V and 30 V were observed to be $23.9{\mu}Ah\;cm^{-2}$, $43.1{\mu}Ah\;cm^{-2}$ and $74.0{\mu}Ah\;cm^{-2}$. We identified it was found that the capacity of $TiO_2$ nanotube/Ti increases with increasing anodizing voltage and the anatase structure of $TiO_2$ nanotube/Ti compared with amorphous structure has batter cycle performance than amorphous $TiO_2$ nanotube/Ti.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.159.2-159.2
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• 2010

Asbestos is the collective name for a group of naturally occurring minerals in their fibrous form and hydrous silicates of magnesium and a mineral fiber that has been used commonly in a variety of building construction materials for insulation and as a fire-retardant. Asbestos has been used for a wide range of manufactured goods, because of its fiber strength and heat resistant properties. Nevertheless harmful of asbestos is quite serious. Exposure to airborne friable asbestos may result in a potential health risk because persons breathing the air may breathe in asbestos fibers. Continued exposure can increase the amount of fibers that remain in the lung. Fibers embedded in lung tissue over time may cause serious lung diseases including asbestosis, lung cancer. In this paper, we carried out as fundamental study for dispose of asbestos cement slate safely and perfectly. Melting Temperature of asbestos need to more than $1,520^{\circ}C$ and specially asbestos cement slate need more energy than that of pure asbestos. We need to decrease melting temperature of asbestos cement slate for economical efficiency. To the purpose, glass and bottom ash were chosen as additives for basicity control. we analyzed about properties of asbestos cements slate, melting characteristics on the additives ratio and temperature. We confirmed about harmlessness of melting slag through analysis of scanning electron microscope(SEM) and x-ray diffractometer(XRD).

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4041-4048
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• 2011

High molecular weight tetrasulfonated poly(arylene biphenylsulfone ether) (TsPBPSEH) copolymers containing up to four pendant sulfonate groups per repeat unit were synthesized via aromatic nucleophilic displacement condensation from 4,4'-bis(4-chloro-3-sulfonatophenylsulfonyl)biphenyl-2,2'-disulfonate (SBCSBPD), 4,4'-dichlorodiphenylsulfone (DCDPS) and 4,4'-(hexafluoroisopropylidene)diphenol (6F-BPA). The synthesized copolymers were structurally characterized using $^1H$ NMR and FT-IR techniques. They were analytically pure, amorphous and were readily soluble in a wide range of organic solvents. Electrolyte membranes were successfully cast using the synthesized polymers with various sulfonation levels and N-methyl-2-pyrrolidinone. This new class of polymer membranes exhibited elevated thermal and physical stabilities and reduced swelling at high temperatures. An increase of acidic functional groups in the copolymer yielded high ion exchange capacity and moderate ionic conductivity values even at higher temperatures, which makes them potential ion conducting candidates.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2685-2690
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• 2013

The activities of Au-modified Cu electrodes toward glucose oxidation are evaluated according to their fabrication conditions and physico-chemical properties. The Au-modified Cu electrodes are fabricated by the galvanic displacement of Au on a Cu substrate and the characteristics of the Au particles are controlled by adjusting the displacement time. From the glucose oxidation tests, it is found that the Au modified Cu has superior activity to the pure Au or Cu film, which is evidenced by the negative shift in the oxidation potential and enhanced current density during the electrochemical oxidation. Though the activity of the Au nanoparticles is a contributing factor, the enhanced activity of the Au-modified Cu electrode is due to the increased oxidation number of Cu through the electron transfer from Cu to more electronegative Au. The depletion of electron in Cu facilitates the oxidation of glucose. The stability of the Au-modified Cu electrode was also studied by chronoamperometry.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2765-2768
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• 2013

The effect of $TiO_2$ nanorods (TNR) and nanoparticles (TNP) composite photoelectrodes and the role of TNR to enhance the energy conversion efficiency in dye-sensitized solar cells (DSSCs) was investigated. The 5% TNR content into the TNP photoelectrode significantly increased the short-circuit current density ($J_{sc}$) and the open-circuit potential ($V_{oc}$) with the overall energy conversion efficiency enhancement of 13.6% compared to the pure TNP photoelectrode. From the photochemical and impedemetric analysis, the increased $J_{sc}$ and $V_{oc}$ for the 5% TNR/TNP composite photoelectrode was attributed to the scattering effect of TNR, reduced electron diffusion path and the suppression of charge recombination between the composite photoelectrode and electrolyte or dye.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.279-301
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• 2008

This paper develops a 3D homogenization based continuum damage mechanics (HCDM) model for fiber reinforced composites undergoing micromechanical damage under monotonic and cyclic loading. Micromechanical damage in a representative volume element (RVE) of the material occurs by fiber-matrix interfacial debonding, which is incorporated in the model through a hysteretic bilinear cohesive zone model. The proposed model expresses a damage evolution surface in the strain space in the principal damage coordinate system or PDCS. PDCS enables the model to account for the effect of non-proportional load history. The loading/unloading criterion during cyclic loading is based on the scalar product of the strain increment and the normal to the damage surface in strain space. The material constitutive law involves a fourth order orthotropic tensor with stiffness characterized as a macroscopic internal variable. Three dimensional damage in composites is accounted for through functional forms of the fourth order damage tensor in terms of components of macroscopic strain and elastic stiffness tensors. The HCDM model parameters are calibrated from homogenization of micromechanical solutions of the RVE for a few representative strain histories. The proposed model is validated by comparing results of the HCDM model with pure micromechanical analysis results followed by homogenization. Finally, the potential of HCDM model as a design tool is demonstrated through macro-micro analysis of monotonic and cyclic damage progression in composite structures.

• Journal of Electrochemical Science and Technology
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• 제8권4호
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• pp.294-306
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• 2017

Stainless steels and titanium alloys are widely used in the medical industry as replacement materials. These materials may be affected by the conditions and type of environment. In the same manner, soft drinks are widely consumed products. It is of interest for dental industry to know the behavior of medical-grade alloys when these are in contact with soft drinks, since any excessive ion release can suppose a risk for human health. In the present study, the electrochemical behavior of three stainless steel alloys and pure titanium was analyzed using three types of cola soft drinks as electrolyte. The objective of this study was to evaluate the response of these metallic materials in each type of solution (cola standard, light and zero). Different electrochemical techniques were used for the evaluation of the alloys, namely potentiodynamic polarization, linear polarization, and open-circuit potential measurements. The corrosion resistance of the stainless-steel alloys and titanium in the cola soft drinks was provided by the formation of a stable passive film formed by metal oxides. Scanning electron microscopy was used as a complementary technique to reveal corrosion phenomena at the surface of the materials evaluated.

• 한국세라믹학회지
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• 제53권4호
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• pp.406-410
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• 2016

Carbon-coated sodium iron pyrophosphate ($Na_2FeP_2O_7$) was prepared by a simple and low-cost pyro-synthesis route for further use as the cathode for Na-ion batteries. The X-ray diffraction (XRD) pattern of the sample annealed at $650^{\circ}C$ confirmed the pure triclinic phase of $Na_2FeP_2O_7$. Electron microscopy studies revealed a cross linked plate shape morphology of the $Na_2FeP_2O_7$ sample. When tested for application in Na-ion battery, the $Na_2FeP_2O_7$ cathode showed two redox pairs in the potential window of 2.0-4.0 V. The cathode registered initial discharge and charge capacities of 80.85 and 90 mAh/g, respectively, with good cycling performance.