• Steel and Composite Structures
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• 제19권6호
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• pp.1561-1580
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• 2015

No significant improvement has been observed on the seismic performance of the ordinary steel reinforced concrete (SRC) columns compared with the reinforced concrete (RC) columns mainly because I, H or core cross-shaped steel cannot provide sufficient confinement for core concrete. Two improved SRC columns by constructing with new-type section steel were put forward on this background: a cross-shaped steel whose flanges are in contact with concrete cover by extending the geometry of webs, and a rotated cross-shaped steel whose webs coincide with diagonal line of the column's section. The advantages of new-type SRC columns have been proved theoretically and experimentally, while construction measures and seismic behavior remain unclear when the new-type columns are joined onto SRC beams. Seismic behavior of SRC joints with new-type section steel were experimentally investigated by testing 5 specimens subjected to low reversed cyclic loading, mainly including the failure patterns, hysteretic loops, skeleton curves, energy dissipation capacity, strength and stiffness degradation and ductility. Effects of steel shape, load angel and construction measures on seismic behavior of joints were also analyzed. The test results indicate that the new-type joints display shear failure pattern under seismic loading, and steel and concrete of core region could bear larger load and tend to be stable although the specimens are close to failure. The hysteretic curves of new-type joints are plumper whose equivalent viscous damping coefficients and ductility factors are over 0.38 and 3.2 respectively, and this illustrates the energy dissipation capacity and deformation ability of new-type SRC joints are better than that of ordinary ones with shear failure. Bearing capacity and ductility of new-type joints are superior when the diagonal cross-shaped steel is contained and beams are orthogonal to columns, and the two construction measures proposed have little effect on the seismic behavior of joints.

• 전기학회논문지
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• 제67권6호
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• pp.789-793
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• 2018

All transparent metal oxide photoelectric device based on $V_2O_5$ was fabricated with structure of $V_2O_5/ZnO/ITO$ by magnetron sputtering system. $V_2O_5$ was deposited by reactive sputtering system with 4 inch vanadium target (purity 99.99%). In order to achieve p-n junction, p-type $V_2O_5$ was deposited onto the n-type ZnO layer. The ITO (indium tin oxide) was applied as the electron transporting layer for effective collection of the photo-induced electrons. Electrical and optical properties were analyzed. The Mott-Schottky analysis was applied to investigate the energy band diagram through the metal oxide layers. The $V_2O_5/ZnO/ITO$ photoelectric device has a rectifying ratio of 99.25 and photoresponse ratios of 1.6, 4.88 and 2.68 under different wavelength light illumination of 455 nm, 560 nm and 740 nm. Superior optical properties were realized with the high transmittance of average 70 % for visible light range. Transparent $V_2O_5$ layer absorbs the short wavelength light efficiently while passing the visible light. This research may provide a route for all-transparent photoelectric devices based on the adoption of the emerging p-type $V_2O_5$ metal oxide layer.

• Advances in environmental research
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• 제9권2호
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• pp.135-150
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• 2020

Many industries, such as textiles, chemical refineries, leather, plastics and paper, use different dyes in various process steps. At the same time, these industrial sectors are responsible for discharging contaminants that are harmful and toxic to humans and microorganisms by introducing synthetic dyes into wastewater. Of these dyes, methylene blue dye, which is classified as basic dyes, is accepted as a model dye. For this reason, methylene blue dye was selected in the study and its removal from the water was studied. In this study, two efficient biosorbents were developed from chitosan and sunflower waste, an agro-industrial waste and modified using iron nanoparticles. The biosorption efficiency was evaluated for methylene blue (MB) dye removal from aqueous solution under various parameters such as treating agent, solution pH, biosorbent dosage, contact time, initial dye concentration and temperature. We investigated the kinetic properties of dye removal from water for Chitosan-Sunflower (CS), Chitosan-Sunflower-Nanoiron (CSN). When the wavelength of MB dye was spectrophotometrically scanned, the maximum absorbance was determined as 660 nm. For the core shell biosorbents we obtained, we found that the optimum time for removal of MB from wastewater was 60 min. The pH of the best pH was determined as 5 in the studied pH. The most suitable temperature for the experiment was determined as 30℃. SEM-EDAX, TEM, XRD, and FTIR techniques were used to characterize biosorbents produced and modified in the experimental stage and to monitor the change of biosorbent after dye removal. The interactions of the paint with the surface used for removal were explained by these techniques. It was calculated that 80% of CS and 88% of CSN removed MB in optimum conditions. Also, the absorption of MB dye onto the surface was investigated by Langmiur and Frendlinch isotherms and it was determined from the results that the removal was more compatible with Langmiur isotherm.

• 한국응용과학기술학회지
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• 제34권4호
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• pp.746-755
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• 2017

본 연구에서는 $CeO_2$ 표면에 $Ti(SO_4)_2$의 가수 분해를 이용하여 $TiO_2$를 성장시켜 코어-쉘 구조를 가지는 세라믹 나노입자를 합성 하였다. $CeO_2/TiO_2$ 코어-쉘 합성에서는 $CeO_2:TiO_2$의 몰비, 반응 시간, 반응 온도, $CeO_2$ 슬러리 농도, $Ti(SO_4)_2$의 pH 조절을 통하여 코어-쉘 구조를 가지는 최적의 합성 조건을 찾았다. $CeO_2:TiO_2$의 최적의 몰비는 1:0.2~1.1, 최적의 반응 시간은 24 시간, 최적의 $CeO_2$ 슬러리 농도는 1%, 최적의 반응 온도는 $50^{\circ}C$임을 알 수 있었다. $NH_4OH$ 수용액을 이용하여 $Ti(SO_4)_2$ 의 pH를 1로 맞추어 $CeO_2$ 슬러리에 적하하면 10%의 농도를 가지는 $CeO_2$ 슬러리에서도 $CeO_2/TiO_2$ 코어-쉘 나노 입자를 합성할 수 있었다. $80^{\circ}C$이상의 높은 온도에서 반응을 시키면 $CeO_2/TiO_2$ 코어-쉘 구조가 아닌 독립된 $TiO_2$ 나노 입자를 형성함을 알 수 있었다. 최적의 반응 온도는 $50^{\circ}C$로서 가장 좋은 구조의 $CeO_2/TiO_2$ 코어-쉘이 합성되었다.

• 한국입자에어로졸학회지
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• 제9권4호
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• pp.209-219
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• 2013

We have used the modified diffusion flame burner to synthesize silica coated iron oxide nanoparticles having enhanced superparamagnetic property. Silica-encapsulated iron oxide particles were directly observed using a high resolution transmission electron microscope. From the energy dispersive X-ray spectroscopy (EDS) and zeta potential measurements, the iron oxide particles were found to be completely covered by a silica coating layer. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements revealed that the iron oxide core consists of ${\gamma}-Fe_2O_3$ rather than ${\alpha}-Fe_2O_3$. Our magnetization measurements support this conclusion. Biocompatibility test of the silica-coated iron oxide nanoparticles is also conducted using the protein adsorption onto the coated particle.

• 한국의류학회지
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• 제19권6호
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• pp.946-954
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• 1995

The purpose of this study is to modify the hydrophobic property and dyeability of polyethylene terephthalate fiber. Methacrylic acid (2nA) was graftpolymerized with benzoyl peroxide (BPO) as initiator onto polyethylene terephthalate fabrics. The results were as follow; 1. Graft-polymerization exhibited maximum graft ratio at a temperature of 100"C. 2. The polymer was gradually grafted in great amount to the surface of MA-g-PET as graft ration increase; with the cross-section examination of MA-g-PET, it was discovered that graft-polymeriation had also taken place inside the textile core. 3. Dyes absorption of basic dyes and disperse dyes was improved as craft ratio increase; with resistance to laundering, the former showed grade 3-4 and the latter showed grade 5.de 5.

• 수산해양기술연구
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• 제40권2호
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• pp.155-160
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• 2004

Water jet trajectories and velocity deficits from a high pressurize nozzles were experimentally observed. In this article, several parameters affecting plugging and erosion onto the steam generator tube were quantitatively analyzed. Visualization, velocity distribution, and spray growth rate with different nozzle configurations have been mainly focused using a 2-D PDPA (Phase Doppler Particle Analyzer) system. The results indicated that trajectories along the centerline regardless of their momentum has its potential core region. However, the phenomena from the peripheral part need to be meticulosly considered. Accordingly, it is evident that quantitative velocity deficits at the outer region are outstanding due to the aerodynamical drag and entrainment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.100.5-100
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• 2002

A core technology for implementation of Augmented Reality is to develop a merging algorithm between interesting 3-D objects and real images. In this paper, we present a 3-D object recognition method to decide viewing direction toward the object from camera. This process is the starting point to merge with real image and 3-D objects. Perspective projection between a camera and 3-dimentional objects defines a plane in 3-D space that is from a line in an image and the focal point of the camera. If no errors with perfect 3-D models were introduced in during image feature extraction, then model lines in 3-D space projecting onto this line in the image would exactly lie in this plane. This observa...

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.971-976
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• 2012

Silica-coated Au with Ag, Co, Cu, and Ir bimetallic radioisotope nanoparticles were synthesized by neutron irradiation, after coating $SiO_2$ onto the bimetallic particles by the sol-gel St$\ddot{o}$ber process. Bimetallic nanoparticles were synthesized by irradiating aqueous bimetallic ions at room temperature. Their shell and core diameters were recorded by TEM to be 100 - 112 nm and 20 - 50 nm, respectively. The bimetallic radioisotope nanoparticles' gamma spectra showed that they each contained two gamma-emitting nuclides. The nanoparticles could be used as radiotracers in petrochemical and refinery processes that involve temperatures that would decompose conventional organic radioactive labels.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2007년도 정기학술대회
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• pp.182-191
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• 2007

This paper gives a thorough investigation into Mandarin sentence-final particles (henceforth SFPs). First I induce core grammatical functions and semantic interpretations of SFPs. Based on Rizzi's (1997) Split CP hypothesis, I make some modifications to accommodate Mandarin SFPs and map them onto separate functional heads within a proper hierarchy. I also examine some empirical evidence of head directionality and tentatively assume Mandarin C is head-initial. To explain the surface head-final order, in light of Chomsky's (2001) Phase Theory and Hsieh's (2005) revised Spell-out hypothesis, I pose a CP complement to Spec movement. Following Moro's (2000) idea, I further claim the motivation behind is to seek for antisymetry.