• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.817-822
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• 2000

A proper flashing light is expected to enhance microalgal biomass productivity and photosynthetic efficiency. The effect of flashing light on high-density Chlorella kessleri (UTEX 398) cultures was studied using light-emitting diodes. A frequency modulator was designed to flash LEDs, and the device successfully provided wide range of frequencies and various duty cycles of flashing. A relatively high frequencies of 10, 20 and 50 kHz were used in this study. These frequencies have very short flashing time ($2-50{\mu}s$), which corresponded to the time constant of the light reaction of photosynthesis. The specific oxygen production rates of photosynthesis under flashing light were compared with those under an equivalent continuous light in specially designed illumination cuvette. The specific oxygen production rates under flashing light were 5-25% higher than those under the continuous light. A range of cell concentration was discovered, where the benefit of flashing light was maximized. The photosynthetic efficiency was also higher under flashing light with frequencies of over 1 kHz, which was a clear indication of flashing light effect and the degree of mutual shading could by overcome by flashing lights, particularly at high-density algal cultures.

• Korean Institute of Interior Design Journal
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• v.15 no.3 s.56
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• pp.65-74
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• 2006

This study is intended to analyze the way of incorporating the effect of natural light into the architectural space design by Le Cobusier. The composition of modem architectural space is significantly different from that of classical architecture. Such transition is attributable to the change of tectonic method which was supported by the development of new materials and structural systems. In addition, the effect of natural light systems which is one of the main elements in architectural space has undergone significant changes in modern ages. Moreover, Le Corbusier introduces the new concept of natural light in his works. By bringing the above two trends together, this study analyzed the way how Le Cobusier applied light effect in his works. Specifically, findings regarding the 'traffic flow in the space' with the light, 'elevation effect' with the 'Brise soleil' in Le Cobusier's works were presented. And also the way of lighting the object in the space was presented.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.383-390
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• 2020

Blue light is a blue-based light existing at a wavelength between 380 and 450 nm, and it has been reported that it induces active oxygen and causes aging, and accordingly, interest in the blue light blocking effect is increasing. In this study, the effects of the polarity of oil, viscosity of the formulation, type of emulsifier, emulsified particles, and inorganic UV blocking agents on the blue light blocking effect in UV blocking products were investigated. As a result, it was confirmed that the blue light blocking rate increased as the polarity of the oil became similar to that of the organic UV blocker, and the higher the viscosity of the formulation, the higher the blue light blocking rate. The types of emulsifiers and emulsified particles had little effect on the blue light blocking effect, and the presence of inorganic UV blocking agents was found to be one of the factors that greatly influenced the blue light blocking rate. These results can effectively increase the efficiency of blocking blue light, and may be used in the development of blue light blocking products and formulation research in the future.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.953-956
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• 2009

We have investigated the effect of light on amorphous silicon thin film transistors based photo-sensor applications. We have analyzed the instability caused by electrical gate bias stresses under the light illumination and the effect of photo-induced quasi-annealing on the instability. Threshold voltage ($V_{TH}$) under the negative gate bias stress with light illumination was more decreased than that under the negative gate bias stress without light illumination even though $V_{TH}$ caused by the light-induced stress without negative gate bias was shifted positively. These results are because the increase of carrier density in a channel region caused by the light illumination has the enhanced effect on the instability caused by negative gate bias stress. The prolonged light illumination led to the recovery of shifted VTH caused by negative gate bias stress under the light illumination due to the recombination of trapped hole charges.

• Korean Institute of Interior Design Journal
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• v.23 no.5
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• pp.25-32
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• 2014

The purpose of this study is to analyze the expression method and visual characteristics of material utilized the lighting in terms of a visual aspect. The method of study is to establish standards for analysis and to classify type of visual effect and expression of that focused on preliminary study. And It is to grasp the visual expression characteristics of new materials. through analysis standards. The results of the study are as follows. First, 'decorativeness', 'symbolization', 'motion-images' and 'interactivity' were selected as the type of visual expression through the precedent studies. And it was classified the visual effects as 3 types like 'a light-emitting effect', 'steric effects' and 'movement effect'. Second, We could know that 'light-emitting effect' was expressed in 7-new materials, 'three-dimensional effect' was expressed in 3-new materials, and 'motion effect' in 4-new materials. Through that. We could know that the new materials represented with 'light-emitting effect' are much more than the other new materials. Third, the results of this study show that 'decorativeness' in the visual types was appeared to 'light-emitting effect' and 'three-dimensional effect'. 'symbolization' to 'light-emitting effect' and 'motion effect', 'motion-images' to 'three-dimensional effect' and 'motion effect' and 'interactivity' to 'light-emitting effect', 'three-dimensional effect' and 'motion effect'. And It was appeared to three effects in 'interactivity'. We could know that it is more effective to be presented the visual effect simultaneously to communication with the visual perception.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.904-911
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• 2019

Objective: The study was conducted to evaluate the effects of night light regimen on growth performance, antioxidant status and health of Lingnan Yellow broiler chickens from 1 to 21 days of age. Methods: A completely randomized factorial design involved 2 photoperiods (constant lighting [CL], 24 L:0 D and intermittent lighting [INL], 17 L:3 D:1 L:3 D)${\times}2$ light intensities (10 lx and 30 lx). A total of one thousand six hundred and eighty 1-d-old Lingnan Yellow broiler chicks were randomly divided into 4 treatments with 6 replicates (70 birds per replicate). The experiment lasted for 21 d. Results: Photoperiods and light intensities had no effect on average daily gain, feed conversion ratio, and mortality of the broiler chickens (p>0.05). The INL had a significant effect on average daily feed intake (p<0.05) of broiler chickens compared with CL. Photoperiod and light intensity had an interactive effect on melatonin (MT) concentration (p<0.05). At CL, reducing light intensity increased MT concentration; INL birds had higher MT but MT concentration was not affected by light intensity. There was an interactive effect on glutathione peroxidase (GPx) and catalase (CAT) in serum and total antioxidant capability (T-AOC) in liver between photoperiod and light intensity. With the decrease of light intensity, the activities of GPx and CAT in serum and T-AOC in liver increased in CL group (p<0.05). Broiler chickens reared under INL had better antioxidant status and 10 lx treatments had higher activities of CAT in serum than 30 lx (p<0.05). Different photoperiods and light intensities had no effect on malondialdehyde. There was an interaction between photoperiod and light intensity on serum creatine kinase (CK) concentration (p<0.05). At CL, the elevated light intensity resulted in an increase in CK content; INL birds had lower CK concentration especially in low light intensity group. Besides, INL and low light intensity significantly reduced the concentration of serum corticosterone and heat shock protein 70 (p<0.05). Serum immunoglobulin M contents were increased in broiler chickens reared under the INL compared with CL group (p<0.05). Conclusion: Results above suggest that the night light regimen of INL and 10 lx could be beneficial to the broiler chickens from 1 to 21 days of age due to the better health status and electricity savings.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.9-14
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• 2014

We numerically investigate the effect of sunlight polarization on the absorption efficiency of V-shaped organic solar cells (VOSCs) using the finite element method (FEM). The spectral distribution of absorbance and the spatial distribution of power dissipation are calculated as a function of the folding angle for s-and p-polarized light. The absorption enhancement caused by the light-trapping effect was more pronounced for s-polarized light at folding angles smaller than $20^{\circ}$, where s-polarized light has a relatively larger reflectance than p-polarized light. On the other hand, the absorption efficiency for p-polarized light is relatively larger for folding angles larger than $20^{\circ}$, where the smaller reflectance at the interface of the VOSC is more important in obtaining high absorption efficiency.

• Journal of Institute of Convergence Technology
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• v.1 no.1
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• pp.29-33
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• 2011

This study is performed to investigate the effect of the artificial light for room lightening. To do that, the experiments were done using the black room with 1m3 and performed to show the effect of the length between the room and light source and light intensities as LUX. The LUX of 18 sites in the room was measured using LUX meter. The length between the room and the light source was chosen as 500mm, 1000mm, and 1500mm and the light intensities was 3 levels. The results were shown the distinct difference between the part directly projected through the light path and non-directly projected. So, the light delivery path have to be modified for next step research. The results were very sensitive for the part directly projected through the light path. This study showed the basic results for room lightening using light source to simulate the solar lightening and was worth in a strict sense as fundamental study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.7-13
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• 2014

As issues on light pollution is being raised recently, movements to prevent light pollution is being implemented by each local government, such as by enforcing the Light Pollution Act from February 2013, in order to require compliance with the light-emitting permission level of existing lighting facilities. However, despite the regulations, no specific measures on products are being prepared. Thus, this Research has designed a light shield as a measure to minimize the burden of the effectiveness and time required for development and the burden of the cost necessary to re-install existing light facilities in its entirety and reviewed the effect of the measure through the BUG ratings.

• Journal of Science Education
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• v.44 no.1
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• pp.112-121
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• 2020

The photoelectric effect is a representative phenomenon explaining the particle nature of light and is an important theme that led to the transition from classical physics to modern physics. Although the secondary school curriculum deals with the photoelectric effect, teachers and students are often confused with terms because the explanation of the 'light intensity' is different from that of electromagnetic waves. Hence, this study examines how modern physics textbooks explain the intensity of light through photon model. We analyzed the photoelectric effect unit of 10 modern physics textbooks. Results show that there are two different types of representation on 'light intensity.' Especially those two different types were found even within a textbook. Modern physics textbooks do not seem to provide a unified presentation of the light and cautions to describe the photoelectric effect and its interpretation are suggested for teaching light intensity in modern physics.