• Title/Summary/Keyword: Light conditions

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Compression Behavior of Wood Stud in Light Framed Wall as Functions of Moisture, Stress and Temperature

  • Park, Joo-Saeng;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.5
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    • pp.19-28
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    • 2006
  • There has been considerable research in recent times in light-timber med structures in fires. These structures have included horizontal (floor-like) panels in bending and walls under eccentric and approximately concentric vertical loading. It has been shown that compression properties are the most dominant mechanical properties in affecting structural response of these structures in fire. Compression properties have been obtained by various means as functions of one variable only, temperature. It has always been expected that compression properties would be significantly affected by moisture and stress, as well. However, these variables have been largely ignored to simplify the complex problem of predicting the response of light-timber framed structures in fire. Full-scale experiments on both the panels and walls have demonstrated the high level of significance of moisture and stress for a limited range of conditions. Described in this paper is an overview of these conditions and experiments undertaken to obtain compression properties as a functions of moisture, stress and temperature. The experiments limited temperatures to $20{\sim}100^{\circ}C$. At higher temperatures moisture vaporizes and moisture and stress are less significant. Described also is a creep model for wood at high temperatures.

Identification and Isolation of Differentially Expressed Gene in Response to Cold Stress in a Green Alga, Spirogyra varians (Zygnematales)

  • Han, Jong-Won;Yoon, Min-Chul;Lee, Key-Pyoung;Kim, Gwang-Hoon
    • ALGAE
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    • v.22 no.2
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    • pp.131-139
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    • 2007
  • The expression of genes responding to cold stress in a freshwater alga, Spirogyra varians, was studied by using differential expression gene (DEG) method. A gene strongly up-regulated in 4°C was isolated and designated as SVCR2 (Spirogyra varians cold regulated) gene. The cDNA encoding SVCR2 was cloned using λZAP cDNA library of Spirogyra varians. The deduced amino acid had a sequence similarity with trans-membrane protein in Arabidopsis thaliana (Q9M2D2, 52.7%). Northern blot analysis demonstrated that transcript level of SVCR2 increased about 10 fold under low temperature (4°C), compared with that cultured at warm (20°C) conditions. The expression of SVCR2 was also affected by light conditions. When the plants were exposed to high light (HL) (1200 μmol photon m–2 s–1), the expression of SVCR2 began within 2 hrs. This gene expression lasted for 4 hrs and decreased afterwards. Under the blue light (470 nm) condition, the expression of this gene was induced in same way as HL treatment, even under less than 100 μmol photon m–2 s–1. But red light (650 nm) and UV-A irradiation did not affect the expression of SVCR2.

A Comparative Evaluation on Visual Performance of CRT and TFT-LCD as Desktop Computer Displays (데스크탑용 CRT와 TFT-LCD의 시각 작업수행도 비교·평가)

  • Kim, Sang-Ho;Choi, Kyung-Lim
    • Journal of the Ergonomics Society of Korea
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    • v.21 no.1
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    • pp.95-112
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    • 2002
  • Two experiments were carried out to compare the suitability in visual tasks between cathode-ray tube (CRT) and thin film transistor-liquid crystal display (TFT-LCD). In the first experiment, the subjects were requested to detect pre-assigned target words or icons among distracters presented under time-invariant (static) image mode. The subjects' visual performance and fatigue were assessed while carrying out search tasks with dim and bright ambient light conditions. Significant interaction effects were found among displays, task types, and ambient light conditions. Due to visual fatigue, the subjects' accommodative power decreased in the end of task and the degradation was more significant for the CRT users and under bright ambient light. IN the second experiment, the subjects performed information processing task with time-varying road signs at a driving simulator to assess interaction effects between display types and changing speed of dynamic image. The perception time using TFT-TCD was shorter under slow image change while that of CRT was shorter rapid image change. Findings from this study suggest that, to improve visual task performance, users should carefully select their visual display type depending on the task to be performed.

Investigation of Lighting Conditions and Visitors' Satisfaction in Exhibition Spaces of Museums in Korea - Focused on the 4 Cases of the Seoul Museum, the Mimesis Art Museum, the Seoul Museum of Art in Nowon and the National Museum of Modern and Contemporary Art in Gwacheon -

  • Kim, Chang-Sung
    • KIEAE Journal
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    • v.14 no.5
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    • pp.13-20
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    • 2014
  • Museums have developed various needs of the visitors and exhibits over the past two centuries. Currently, they have multiple functions of display, conservation, research and public education about artworks and cultural events. Therefore, exhibits should be displayed in various ways so that visitors can feel inter-relations with exhibits. The exhibition areas of museums should be provided with the stable lighting environment for visitors and artworks. For the study, I selected four museums, which were the Seoul Museum, the Mimesis Art Museum, the Seoul Museum of Art in Nowon and the National Museum of Modern and Contemporary Art in Gwacheon, and I measured illumination levels of the selected Museums, and then, I surveyed the visitors' responses on the lighting conditions of them. According to the results, the measurements of the illumination levels in the four museums showed that the illumination levels of them were effectively controlled to display the art works. However, the illuminance levels at some areas that drew the natural light as lighting source were much higher than recommended illumination values for museum. In the mean time, the answers of questionnaires showed that the natural light were so effective to light the museums although the natural light provided some areas with high illumination levels.

Verification for transcription of spherical radius and prediction of birefringence in injection molding optical lens (초정밀 광학렌즈의 복굴절 예측과 금형 전사성)

  • Ohmori Hitoshi;Kwak Tae Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.55-60
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    • 2005
  • This paper has been focused in developing of plastic lens with ultra-precision and low birefringence ability using by injection molding simulation tools. The simulation tools, $3D-Timon^{TM}\;and\;Asu-Mold^{TM}$ were applied to visualize indirectly the flow pattern of melted polymer enter the mould and the simulation results are verified as compared with the experimental results. Birefringence and polarized light generated in injection molding process was also calculated for each injection conditions and compared with .the pictures of experimented optical lens go through the polarized light plates device. A spherical radius of plastic optical lens transcribed from profile of mould core surface was measured to estimate the geometrical accuracy fer the each injection conditions. It is confirmed that the simulation results about flow pattern and polarized light area coincided in experimental results. It is known that increasing in thickness shrinkage at center of lens, the spherical radius is larger from comparing the graph measured spherical radius and the thickness shrinkage at center of lens

Nonthermal Sterilization of Animal-based Foods by Intense Pulsed Light Treatment

  • Gyeong Mi Lee;Jung-Kue Shin
    • Food Science of Animal Resources
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    • v.44 no.2
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    • pp.309-325
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    • 2024
  • The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

Natural Dyeability of Cow leather dyeing with Turmeric powder (울금 분말을 이용한 우피의 천연염색)

  • Bai, Sang-Kyoung
    • Journal of Fashion Business
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    • v.15 no.4
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    • pp.182-189
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    • 2011
  • Dyeing properties of cow leather was investigated with Tumeric powder. The effects of dyeing conditions, mordanting conditions, color change, and color fastnesses were studied. The results were as follows. The dye uptake increased as dye concentration, dyeing temperature, and bath ratio increased. In the effect of dyeing time, the highest dye uptakes showed at 20 minutes and decreased after that point. Pre mordanting was more effective than the post mordanting, and the dye uptakes improved all mordanted fabrics. The highest K/S values showed in pre-Al sample, and the lowest K/S values showed in post-Cu one. The values of Hunter on the samples were more changeable $L^*$ and $b^*$ than $a^*$, and all samples showed Yellow color in Munsell value. But the mordanting methods and mordanting agents were not significant in the color changes. The light fastness of dyed samples showed 1 grade, the dry cleaning and abrasion fastnesses did not improved except post-Fe wet sample.

Carbody strength evaluation for a light rail vehicle (경전철 차량 개발을 위한 차체 강도 평가)

  • 김진혁;박근수;박상규
    • Proceedings of the KSR Conference
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    • 1998.05a
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    • pp.466-473
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    • 1998
  • LRV(Light Rail Vehicle) is one of the most useful way for urban transit. HDPIC has designed and manufactured the LRV train set for Manila Line 1 expansion. The LRV is composed of two carbody sections which are coupled by a articulated bogie. The articulated bogie and two motorized bogies have slewing rings in order to improve the curving performance and ride quality. Carbody structures are mainly made of low-carbon stainless steel (STS301L), and the carbody bolsters and draft sills are made of rolled steel for welded structures. The authority's specifications specified the design load conditions and weight limits. Design load conditions are vertical load, compressive load and diagonal jacking, and the maximum axle load is 10.7 ton. In order to meet those requirements, the stiffness and strength of carbody structure were predicted using finite element analysis during design stage. The half or full structure is modeled and analyzed with design load conditions, and critical areas are analysed in detail using sub-modeling method. The strength and strength of carbody structure was also verified by the load test. The analysis and test results show a good agreement.

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Experimental Evidence for New Pinning Conditions in Strongly Pinned Permalloy Film

  • Han, Kyung-Hunn;Cho, Jae-Hun;Lee, Suk-Mock
    • Journal of Magnetics
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    • v.12 no.1
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    • pp.27-30
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    • 2007
  • Experimental evidence suggests that spin pinning conditions for standing spin mode in polycrystalline $Ni_{84}Fe_{16}$ alloy film, is confirmed using the four categories of Camley et al. and the value of q$\bot$ for the pinning conditions, this was achieved by performing Brillouin light scattering measurements. The value of q$\bot$ was observed, in order to increase at a rate of $\pi$/2 with an increasing mode number. With this condition, the coexistence of standing spin wave modes was shown, with intermediate pinning, in addition to free and strong pinning. The values for spin-wave-stiffness constant ($D_B$), g-factor (g), and surface magnetization (4$\pi$M) of the Permalloy film were obtained from the results of BLS, and determined to be $D_B=1.85{\pm}0.05Oecm^2$, $g=2.11{\pm}0.02$, and 4$\pi$M=8.7 kG, respectively.

Evaluations for Representativeness of Light-Duty Diesel Vehicles' Fuel-based Emission Factors on Vehicle Operating Conditions (연료 소비량에 기반한 소형 경유차 대기오염물질 배출계수의 운전조건별 대표성 평가)

  • Lee, Taewoo;Kwon, Sangil;Son, Jihwan;Kim, Jiyoung;Jeon, Sangzin;Kim, Jeongsoo;Choi, Kwangho
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.6
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    • pp.745-756
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    • 2013
  • The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.