• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.241-241
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• 2010

Recently high and persistent spontaneous buildup of a surface potential (SP) upon vacuum deposition of tris (8-hydroxyquinolinato) aluminum (III) ($Alq_3$), which is widely used for organic light emitting devices. The removal of the giant surface potential by visible light irradiation has also been reported. In this study, we coated $Alq_3$ on the FTO substrate and raise the capacity for absorbing sun light. The $Alq_3$ which is green light emitting diode emits light at wavelengths between 500 and 550nm. If we apply one's FTO/$Alq_3$ substrate in one's DSSC, we could get higher energy conversion efficiency because the N719 dye that we used for fabricating the DSSC emits light just at near 540nm. The energy conversion efficiency of approximately 4.8 % at the condition of irradiation of AM 1.5 (100 mW/$cm^2$) simulated sunlight, and the $J_{sc}$ is 12.0 mA/$cm^2$, $V_{oc}$ is 0.71 V, FF is 0.56, respectively.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.616-622
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• 2016

Baicalein (5,6,7-trihydroxy-2-phenyl-chromen-4-one) is a flavone, a type of flavonoid, originally isolated from the roots of Scutellaria baicalensis. This study evaluated the protective effects of baicalein against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) radiation in a human keratinocyte cell line (HaCaT). Baicalein absorbed light within the wavelength range of UVB. In addition, baicalein decreased the level of intracellular reactive oxygen species (ROS) in response to UVB radiation. Baicalein protected cells against UVB radiation-induced DNA breaks, 8-isoprostane generation and protein modification in HaCaT cells. Furthermore, baicalein suppressed the apoptotic cell death by UVB radiation. These findings suggest that baicalein protected HaCaT cells against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging ROS.

• 한국수소및신에너지학회논문집
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• 제15권3호
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• pp.220-227
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• 2004

The purpose of this paper is, based on the theoretical background of the principle of gas purification and absorption, and the absorbing ability of metals, to syudy the efficiency of gas purification of inorganic gases using Zr alloys, so as to contribute to the IT industry. To produce and distribute gas with high purity and ultra-high purity, different types of gas purifier are currently being used: distillation type, getter type, catalyst type, absorption at low-temperature type, and membrane separation equipment. From the different purification methods mentioned above, the getter type gas purifier is capable of not only high performance and capacity but also P.O.U(Point Of Use) method. The key of the getter type gas purifier is its efficiency of gas purification, which is the subject chosen for this study.

• Earthquakes and Structures
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• 제11권5호
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• pp.887-904
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• 2016

An efficient, economical and practical strengthening method for hollow brick infill walls was proposed and investigated in the present study, experimentally and numerically. This method aims at increasing the overall lateral strength and stiffness of the structure by increasing the contribution of the infill walls and providing the non-bearing components of the structure with the capability of absorbing earthquake-induced energy to minimize structural damage during seismic excitations. A total of eleven full-scale infill walls strengthened with expanded mild steel plates were tested under diagonal monotonic loading to simulate the loading condition of the non-bearing walls during an earthquake. The contact surface between the plates and the wall was increased with the help of plaster. Thickness of the plates bonded to both faces of the wall and the spacing of the bolts were adopted as test parameters. The experiments indicated that the plates were able to carry a major portion of the tensile stresses induced by the diagonal loads and provided the walls walls with a considerable confining effect. The composite action attained by the plates and the wall until yielding of the bolts increased the load capacities, rigidities, ductilities and energy-absorption capacities of the walls, considerably.

• 대한기계학회논문집A
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• 제25권7호
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• pp.1131-1138
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• 2001

This paper concerns the crashworthiness of the widely used vehicle structure, the spot welded hat and double hat shaped section members, which are excellent on the point of the energy absorbing capacity and low production cost. The target of this paper is to analyze the energy absorption capacity of the structure against the front-end collision, and to obtain useful information for designing stage. Changing the spot weld pitches on the flanges, the hat and double hat shaped section members were tested on the axial collapse loads in impact velocities of 4.72m/sec, 6.54m/sec, 7.19m/sec and 7.27m/sec. To efficiently review the collapse characteristics of these sections, the simulation have been carried out using explicit FEM package, LS-DYNA3D. The solutions are compared with results from the impact collapse experiments.

• 교육시설 논문지
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• 제20권1호
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• pp.37-44
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• 2013

The present study examines the effects of periodic type diffusers for producing the preferred acoustics for speech and determines the more successful configurations of sound-absorbing and diffusing treatments for achieving good acoustics in classrooms. The measurements were carried out in a 1/10 scale model classroom systematically adding diffusers to one or more of four surfaces of the room. A total of 13 combination of diffusers with absorptive treatments were investigated. Adding diffusers on the ceiling were more effective to increasing the early-arriving reflection energy($G_{50}$) than adding absorptive materials on the entire ceiling. The late arriving reflection energy($G_{late}$) was decreased with increasing amounts of diffusing treatments of upper front or rear wall and this resulted in achieving higher early-to-late ratios($G_{50}$). Adding diffusers on the upper front wall($AC_{100}DUFW_{26}$) achieved more uniform acoustical conditions over the receiver positions than adding diffusers on the upper rear wall($AC_{100}DUFW_{26}$). Adding diffusers on the ceiling and absorptive materials on the lower front wall($AC_{75}DC_{25}ALFW_{26}$) achieved better acoustical conditions than adding the absorptive materials on the entire ceiling and lower front wall($AC_{100}ALFW_{26}$).

• Journal of Ship and Ocean Technology
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• 제5권3호
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• pp.36-44
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• 2001

The collision energy absorbing characteristics of side structure of the LNG carriers which have the cargo containment systems of the spherical and the membrane types are compared. A failure mechanism of the double hull side structures of 130, 000 $m^3$ class LNG carriers under sideways collision event has been simulated by using the detailed finite element calculations. In ship collision analysis, the finite element method based on explicit time integration has been use[1 with much success. Finite element modeling techniques for detail description of structural members antral ship motion regarding the dynamic behavior allowed to investigate the effect of bow shape and the initial contact position on side shell of collided ship. In the numerical simulations of the ship-to-ship sideways collision, the effect of the colliding bow shapes and the change of the colliding ship draft are investigated. The critical collision energy which is absorbed by a side structure of a collided ship until the fore-end of colliding ship arrives at the boundary of the cargo tank is calculated. The critical speed of specified colliding ships which can not penetrate the boundary of the LNG cargo tank of the collided ship under collision accident if evaluated.

• 한국수소및신에너지학회논문집
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• 제10권2호
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• pp.91-99
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• 1999

Mg, Ni, graphite chips을 원료로 하여 기계적 합금화를 수행한 결과, 분위기 수소와 carbon의 불안정한 유기화합물이 합성되어 사료 획득시에 격렬한 발화 현상을 야기하는 것으로 생각되며 수소 분위기에서 45Mg+55Ni chips을 합성한 후 graphite를 첨가하여 Ar 분위기에서 합금화한 결과 Mg-Ni-C가 합성되었다. 개선된 공정에서 획득한 시료는 623K에서 약 4.9 wt%의 수소를 저장하지만 안정한 Mg-Ni-C-H의 합성여부와 수소화 특성등은 보다 면밀한 물리화학적 검토가 필요할 것으로 사료된다.

• 전력전자학회논문지
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• 제17권1호
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• pp.34-40
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• 2012

In this paper, voltage clamped tapped-inductor boost converter with high voltage conversion ratio is proposed. The conventional tapped-inductor boost converter has a serious drawback such as high voltage stresses across all power semiconductors due to the high resonant voltage caused by the leakage inductor of tapped inductor. Therefore, the dissipative snubber is essential for absorbing this resonant voltage, which could degrade the overall power conversion efficiency. To overcome these drawbacks, the proposed converter employs a voltage clamping capacitor instead of the dissipative snubber. Therefore, the voltage stresses of all power semiconductors are not only clamped as the output voltage but the power conversion efficiency can also be considerably improved. Moreover, since the energy stored in the clamp capacitor is transferred to the output side together with the input energy, the proposed converter can achieve the higher voltage conversion ratio than the conventional tapped-inductor boost converter. Therefore, the proposed converter is expected to be well suited to various applications demanding the high efficiency and high voltage conversion ratio. To confirm the validity of the proposed circuit, the theoretical analysis and experimental results of the proposed converter are presented.

• 설비공학논문집
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• 제17권10호
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• pp.891-897
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• 2005

The characteristics of energy Performance for total heat exchanger have been investigated under various conditions. In cooling operation the latent and enthalpy efficiency are affected by the difference of absolute humidity ratio between indoor and outdoor air. In addition to this the characteristics of absorbing material in the element affects the energy performance. Low dry bulb temperature of indoor air or high absolute humidity ratio in outdoor air give high latent and enthalpy efficiency even with the same temperature difference of dry bulb temperate between indoor and outdoor air.