• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.749-752
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• 2005

Normally, the degradation of concrete member exposed to fire is largely dependent on the fire scale and fire condition. With all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Thus, this study is concerned with experimentally investigating fire resistance of high strength-light weight concrete. From the test result, high strength-light weight concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.375-376
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• 2010

본 연구는 WCP 대체율 및 오토클레이브 양생시간 변화에 따른 경량기포콘크리트의 미세구조 및 광물분석을 통한 화학적 특성을 검토하였다. 경화체의 미세구조 분석으로부터 수열 반응 후 WCP 대체율 및 양생시간에 관계없이 반응하여 판상형, 섬유형의 결정 구조물의 수화물을 형성한 것을 확인하였다. 또한 Tobermorite(C5S6H5)는 WCP의 구성성분인 결정질 Quartz의 반응에 의한 것으로 추정된다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.167-171
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• 2002

We have investigated the optical properties of Te-doped ZnSSe:Te epitaxial layers grown on (100) GaAs substrates by molecular beam epitaxy. The Te-doped ternary specimen shows strong blue or green emission (at 300k) which is assigned to Te$_{1}$ or Te$_{n}$( n$\geq$2) cluster bound exciton. Bright green and blue light-emitting diodes (LEDs) have been developed using ZnSSe:Te system as an active layer. The green LEDs exhibit a fairly long device lifetime (>2000 h) when operated at 3 A/cm$^{2}$ under CW condition at room temperature. It is confirmed that the Te-doping induced "crystal-hardening effect" plays a significant role in both efficient and strong suppression of the optical device degradation.gradation.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.98-105
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• 2008

In this paper, the system for monitoring process of aluminum laser welding was developed using the light signal emitted from the plasma which comes from interaction between material and laser. Photodiode for monitoring system was selected based on the spectrum analysis of light from plasma and keyhole. Behavior of plasma and keyhole was analyzed through the sensor signals. Value of sensor signal represented the light intensity and fluctuation of signal indicated the stability of plasma and keyhole. For the relation between welding condition and sensor signals, the input power and weld geometry greatly effected on the average of each sensor signals. Using the feature values of signals, estimation model for tensile strength of weld was formulated with neural network algorithm. Performance of this model was verified through coefficient of determination and average error rate.

• 한국전기전자재료학회논문지
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• 제21권3호
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• pp.255-259
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• 2008

Built-in voltage in ITO/$Alq_3$/ Al organic light-emitting diodes was studied by varying a thickness of $Alq_3$ layer using modulated photocurrent technique at ambient condition. A thickness of the $Alq_3$ layer was varied from 100 to 250 nm. From the bias voltage-dependent photocurrent, built-in voltage of the device was able to be determined. The obtained built-in voltage is about 0.8 V irrespective of the $Alq_3$ layer thickness in the device. This value of built-in voltage confirms that the built-in voltage is generated due to a difference of work function of the anode and cathode. The $Alq_3$ layer thickness independent built-in voltage indicates that the built-in electric field in the device is uniform across the organic layer.

• 한국수산과학회지
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• 제28권6호
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• pp.805-811
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• 1995

Final biomass yields (peak optical density) and growth rates (divisions/day) of seven clones of Skeletonema costatum from Korean coastal waters were measured to understand their intraspecific variations in the light intensity niche component under $25^{\circ}C$ condition. Daily growth rates of 6 of 7 S. costatum, clones were maximum at 6000 lux while that of YS4, a neritic clone, was maximum at 9000 lux. The final biomass yields of 4 of the 7 S. costatum clones were maximum at the lowest light intensity of 2000 lux. Minimum final biomass yields were found at 9000 lux in all the S. costatum clones other than an estuarine clone, HDC9. The intraspecific variations of the mean growth rate and mean final biomass yield under each of the three different light intensity in terms of the coefficient of variation were not greater than 10% in any of the 7 S. costatum clones.

• Archives of Reconstructive Microsurgery
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• 제17권1호
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• pp.48-50
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• 2008

Loupes-assisted microsurgery often needs an operational head lamp for a better condition of light. This may cause serious neck fatigue due to the weight the operational head lamp, the limitation of the operator's head movement from the hind cable, and some cost for purchasing and management of it. On the contrary, a mountain head lamp is very light, full of freedom in movement, applicable to all types of loupes, and relatively very cheap. In conclusion, a mountain head lame can be a cost-effective light source for Loupes-assisted microsurgery.

• Applied Science and Convergence Technology
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• 제27권2호
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• pp.42-45
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• 2018

Photovoltaic and optoelectronic devices based on hybrid metal halide perovskites ($MAPbX_3$; $MA=CH_3NH_3{^+}$, $X=Cl^-$, $Br^-$, or $I^-$) are rapidly improving in power conversion efficiency. Also, during recent years, perovskite single crystals have emerged as promising materials for high-efficiency photovoltaic and optoelectronic devices because of their low defect density. Here we show that the light soaking effect of mixed halide perovskite ($MAPbBr_{3-x}I_x$) single crystals can be explained using photoluminescence, time-resolved photoluminescence, and Raman scattering measurements. Unlike Br-based single crystal, Br/I mixed single crystal show a strong light soaking effect under laser irradiation condition that was related to the existence of multiple phases.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.40-47
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• 2002

Because UV wavelength lights can activate photocatalysts, plasma is used as a light source of a photocatalytic reactor. Even though plasma has good intensity for photo reaction, substrate of catalyst coating was limited by the geometry of plasma generator. Usually bead type substrate was used for a pack bed type reactor. Honeycomb monolith type substrate was used with UV lamps instead plasma, due to the light penetration the honeycomb monolith length was too short to show good activity In this study a photocatalytic reactor, which is using a honeycomb monolith substrate, was investigated with plasma as an activation light source. As a parametric study the effects of 1311owing factors on plasma generation and power consumption are examined; supply voltage, substrate length, environment condition, catalyst loading and ratio. Using the test results, the practicability test was done with simulated synthetic gases representing bad smells and automotive exhaust gases.

• 한국염색가공학회지
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• 제16권2호
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• pp.41-46
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• 2004

We have studied on the experimental variables such as optimum adsorption condition, color changes, light fastness, antimicrobial properties, and wash durability of the cotton fabrics treated with gallnut extracts. Treatment of gallnut extracts on the cotton fabrics was optimally achieved at 6$0^{\circ}C$ for 60min. Gallnut extracts did not cause unintended color change after treatment on the cotton fabrics dyed with reactive dyes. The cotton fabrics treated with gallnut extracts showed good light fastness, though we took into the account the extract is a natural material. The cotton fabrics treated with 10.0% o.w.f. of gallnut extracts had strong antimicrobial activity and good wash durability.