• Journal of the Korean Solar Energy Society
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• v.39 no.1
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• pp.1-9
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• 2019

Light induced degradation is one of the major research challenges of hydrogenated amorphous silicon related thin film silicon solar cells. Amorphous silicon shows creation of metastable defect states, originating from elevated concentration of dangling bonds during light exposure. The metastable defect states work as recombination centers, and mostly affects quality of intrinsic layer in solar cells. In this paper we present results of light induced degradation in thin film silicon solar cells and discussion on physical origin, mechanism and practical solutions of light induced degradation in thin film silicon solar cells. In-situ light-soaking IV measurement techniques are presented. We also present thin film silicon material with silicon nano-quantum dots embedded within amorphous matrix, which shows superior stability during light-soaking. Our results suggest that solar cell using silicon nano-quantum dots in abosrber layer shows superior stability under light soaking, compared to the conventional amorphous silicon solar cell.

• Food Science and Preservation
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• v.14 no.4
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• pp.400-407
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• 2007

This study compared lipid oxidation and color stability of M. longissimus from five Korean native black barrows (66 kg average weight; KNP) and modern genotype barrows ($Landrace{\times}Yorkshire{\times}Duroc$, 112 kg average weight, MGP) during light exposure in a refrigerated shop display. The meat samples were aged at $1^{\circ}C$ for 5 days and either kept in the dark, or under light of flux 3,000 lux, at $4^{\circ}C$ for 7 days. The KNPs contained larger amounts of fat than did MGPs (p<0.05), but KNPs had lower $C_{14:0},\;Cl_{8:3},\;and\;C_{20:5}$ contents than did MGPs (p<0.05). The pH of KNP was lower than that of MGP, and increased more rapidly upon exposure to light. The TBARS assay showed that oxidized lipid levels increased more rapidly in KNP than in MGP, and this accumulation was accelerated by exposure to light. The KNP was always a darker red in color than was MGP, and the color deteriorated more rapidly in the light than in the dark. The sensory attributes of raw pork were reduced by exposure to light, but KNP showed higher sensory attributes than did MGP. Compared to the MGP, the KNP showed greater color stability under light, retained desired sensory attributes under light longer, but showed a lower lipid oxidation stability under light. Overall, light exposure accelerated lipid oxidation in and discoloration of pork.

• Food Science and Preservation
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• v.10 no.1
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• pp.32-36
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• 2003

Quality stability of the dried layer Porphyra tenera depending on various light sources, water activities, packaging materials and storage temperatures were investigated by peroxide value and chlorophyll degradation. Major fatty acids of dried layer were 45.7％ eicosapentaenoic acid and 13.6% palmitic acid. Quality stability was increased in order of darkness, incandescent and fluorescent increased sharply with the decrease of water activity and temperature, and also improved by the packaging material with strong barriers of water vapor, oxygen and light.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.1
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• pp.37-45
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• 1986

The purpose of this study was to investigate the relationship between color & clothing color preferences and three personality traits. Personality traits were measured with chung's Personality Scale. The questionare measuring Color & Clothing color preferences consisted of items designed to assess color preference, color repugnance clothing color preferences. These questionaire were administered to 302 senior high school girls in Seoul. Statistical analysis consisted of corelation and chi-square-test. The result were; 1) Activity, stability, sociability was no significant related to color preference. 2) Activity, sociability was positively related to color repugnance in Value but stability was no significant. 3) Sociability and stability was positively related to color preference, but activity and stability was no significant. 4) There was a positive relationship between color preference and clothing color preference. (r=0.8867) 5) The most preferred colors were white, light blue, and light green. The most repugnated colors were light red, dark red purple, and dark yellow. 6) The most preferred clothing colors were yellow, pink, and green in Spring, white and blue in Summer all kinds of colors, colors in Autumn, and Black and Grey in Winter.

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.27-34
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• 1989

In the present study, the oxidative stability of Korean evening primrose oil (EPO) stored in various conditions, i.e., dark, cool, fluorescent light and daylight irradiation were investigated. Furthermore difference between the compositional content of gamma-linolenic acid (GLA) of EPO and that of alpha-linolenic acid of soybean oil (SOY) undergoing various modes of oxidation was observed. The results of the present study were as follows: More rapid autoxidative reations of EPO than that of SOY in vairous conditions increased in order of daylight, fluorescent light, cool and dark. Espectially, autoxidative rates of EPO increased rapidly on exposure to daylight and fluorescent light. This probably was due to chlorophyll functioned as a photosensitizer resulting in rapid oxidation of the EPO during irrdadiation of light. However, there was no difference between compositional content of GLA in EPO and alpha-linolenic acid in SOY undergoing various modes of oxidation. Therefore, theripid oxidative rate of EPO could be due to the catalytic effect of the chlorophyll on the photoxidation and the free radical reaction of PUFA.

• International Journal of Aerospace System Engineering
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• v.5 no.1
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• pp.9-18
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• 2018

The longitudinal flight parameters of a light airplane are estimated from flight test data by use of the output error method. The reliability of the flight test measurement is examined in engineering judgment, scatter and Cramer-Rao bound, which turns out to be satisfactory with minor defects. Estimated parameter values are validated by comparing the simulated responses with the ones from actual flight tests. The FTD(Flight Training Device) of a light airplane turns out to satisfy the qualification of FAA Level 5 FTD in longitudinal motion. All the necessary practices for generation of high-fidelity data in longitudinal motion of a light aircraft are successfully performed in this study.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.9-16
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• 2021

As the climate changes rapidly due to warming, it is becoming very important to ensure the stability of environmental structures. It is necessary to choose a material that withstands repeated external forces (wind loads) and satisfies members and joints that have energy absorbing power. Even if the strength of the traffic light attachment is sufficient, if the rigidity is insufficient, there is a limit to the displacement during strong winds. Excessive deformation may cause damage and fall, resulting in a safety accident. The author intends to study mechanical properties and resistance to external environment as a structural material capable of withstanding wind load (50m/sec) by fabricating a C/GFRP composite traffic light attachment using the pultrusion method (Pultrusion).

• Textile Coloration and Finishing
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• v.24 no.3
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• pp.165-172
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• 2012

The stability of yellow and red dyes prepared from safflower (Carthamus tinctorius L.) in aqueous solution and in solid state was investigated. External factors such as light irradiation and temperature on the stability were examined during storage. Changes in absorbance of dye solutions and the color changes of fabrics dyed after long time storage were measured. Also, color reproducibility during storage was investigated by dyeing test on various fabrics. Red colorant in aqueous solution was very unstable to light, resulting that about 40% of absorbance were lost in 12hrs. The absorbance of yellow dye solutions was not decreased within 84hrs. In aqueous medium, yellow dye was much more stable than carthamin. Both dyes are relatively stable for long storage when they are stored in solid state compared to when in aqueous solution. Color changes are marginal in both dyes.

• KSBB Journal
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• v.26 no.5
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• pp.381-385
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• 2011

Studies were made to improve the stability of astaxanthin which has application limitations caused by light and thermal stability problems in spite of its strong anti-oxidant property. Astaxanthin was extracted from Haematococcus pluvialis with supercritical carbon dioxide. Liposomal encapsulation of astaxanthin to improve the stability was made with high pressure homogenizer. The narrow size distribution was observed with astaxanthin liposomes. Tests on light and thermal stabilities resulted that the liposormal encapsulation improved the stability of astaxanthin for cosmeceutical purposes.

• Journal of Powder Materials
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• v.19 no.1
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• pp.55-59
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• 2012

In this work, the silver nanoparticles have been synthesized by electrical explosion of wire in three liquid mediums: deionized water (DIW), polyvinylpyrrolidone (PVP) and sodium dodecyl benzene sulfonate (SDBS) solutions. Absorption in the UV-visible region of these suspensions was measured in the range of 300-800 nm. A surface plasmon peak was observed at ~400 nm in all suspensions in measured wavelength range. Particle size was analyzed by transmission electron microscope. It showed that the particles had nearly spherical shape in all samples. The average particle sizes prepared in DIW, PVP and SDBS solution were 37, 31 and 27 nm, respectively. Stability of the suspensions was estimated by multiple light scattering method. The presence of PVP and SDBS surfactants in the exploding medium resulted in enhanced stability of the silver suspensions.