• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.330-334
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• 1983

The author carried out an experiment to find out the response of gray rock cod, Sebastes inermis (Cuvier et Valenciennes) to the color light. The experimental tank ($360L{\times}50W{\times}55H\;cm$) was set up in a dark room. Six longitudinal sections with 60 cm intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 cm level. Light bulbs of 20W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The colors favourited by the fish was found in the order of white, blue, yellow and red. The gathering rate of fish on illumination period was small and comparatively fluctuated with stability. The difference of the gathering rates on two different colors of light was much greater, regardless of illumination period, in day time than in night time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.191-196
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• 1984

The author carried out an experiment to find out the response of filefish, Navodon modestus(Gunther) to the colored lights. The experimental tank($360L{\times}50W{\times}55Hcm$) was set up in a dark room. Six longitudinal sections with 60 cm intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 cm level. Light bulbs of 20W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before thor were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The colors favourited by the fish was found in the order of blue, white, yellow and red. The gathering rate of fish on illumination period was not constant but varied randomly. The difference of the gathering rates on two different colors of light was rather in significant, however the difference was larger in the day time than in the night time.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.280-280
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• 2014

We report the fabrication and electroluminescent characteristics of GaN/InxGa1-xN microdonut-shaped light-emitting diode (LED) microarrays as variable-color emitters. The diameter, width, height, and period of the GaN microdonuts were controlled by their growth parameters and the geometrical factors of the growth mask patterns. For the fabrication of microdonut LEDs, p-GaN/p-AlxGa1-xN/u-GaN/u-InxGa1-xN heteroepitaxial layers were coated on the entire surface of n-GaN microdonuts. The microdonut LED arrays showed strong light emission, which could be seen with the unaided eye under normal room illumination. Additionally, magnified optical images of microdonut LED arrays exhibited microdonut-shaped light emissions having spatially resolved blue and green colors. Their electroluminescence spectra had two dominant peaks at 460 and 560 nm. With increasing applied voltage, the intensity of the blue emission peak increased much faster than that of the green emission peak, indicating that the color of the LEDs is tunable. We also demonstrated that EL spectra of the devices could be controlled by changing the size of microdonut LEDs. What we want to emphasize here with the microdonut LEDs is that they have additional inner sidewall facets which did not exist for other typical three-dimensional structures including nanopyramids and nanorods, and that InxGa1-xN single quantum well formed on the inner sidewall facets had unique thickness and chemical composition, which generated additional EL color. The origin of the electroluminescence peaks was investigated by structural characterizations and chemical analyses.

• Elastomers and Composites
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• v.45 no.3
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• pp.206-211
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• 2010

Zinc oxide(ZnO) nanoparticles were synthesized by reacting an aqueous-alcoholic zinc nitrate solution to sodium hydroxide under ultrasonic irradiation at room temperature. The fullerene($C_{60}$) and ZnO nanoparticles were heated individually in an electric furnace for two hours at $700^{\circ}C$. The morphology and optical properties of the $C_{60}$ and ZnO nanoparticles were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and ultraviolet/visible (UV-vis) spectroscopy. The photocatalytic activity of the heated and unheated the $C_{60}$ and ZnO nanoparticles for the decomposition of methylene blue(MB), methyl orange(MO) and rhodamine B(RhB) was examined using UV-vis spectroscopy.

• Journal of Pharmaceutical Investigation
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• v.34 no.2
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• pp.91-94
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• 2004

To develop a poloxamer-based solid suppository with poloxamer mixtures, the melting points of various formulations composed of P 124 and P 188 were investigated. To investigate the effect of poloxamer to the dissolution ad dissolution mechanism of diclofenac sodium from the suppository the dissolution of diclofenac sodium delivered by the poloxamer-based suppository was performed. Furthermore, to investigate the mucoadhesive property of the poloxamer-based sold suppository, the identification test in the rectum was carried out after its rectal administration in rats. The poloxamer mixtures composed of P 124 and P 188 were homogeneous. Ver small amounts of P 188 affected the melting points of poloxamer mixtures. In particular, the poloxamer mixture [P 124/P 188 (97/3%)] with the melting point of about $32^{\circ}C$ was a sold for at room temperature and instantly melted at physiological temperature. Furthermore, very small amounts of P 188 in the poloxamer-based suppository hardly affected the dissolution rates of diclofenac sodium from the suppository. Dissolution mechanism analysis showed the dissolution of diclofenac sodium was proportional to the time. At 4 h after administration, the blue colo of poloxamer-based suppository [diclofenac sodium/poloxamer mixture (2.5/97.5%)] with the P 124/ P 188 ratio of (97/3%) and blue lake in the rectum was faded. However, the position of suppository in the rectum did not significantly change with time. Thus, it retained in thε rectum for at least 4 h. Our results indicated that the poloxamer-based sold suppository with P 124 and P 188 would be a candidate of rectal dosage form for diclofenac sodium.

• Journal of the Korea Computer Graphics Society
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• v.24 no.3
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• pp.101-109
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• 2018

Recently, the improvement of virtual reality and augmented reality technologies leverages many new technologies like the virtual study room, virtual architecture room. Such virtual worlds require free handed drawing technology such as writing descriptions of formula or drawing blue print of buildings. In nature, lots of view point modifications occur when we walk around inside the virtual world. Especially, we often look some objects from near to far distance in the virtual world. Traditional drawing methods like using fixed size image for drawing unit is not produce acceptable result because they generate blurred and jaggy result as view distance varying. We propose a novel method which robust to the environment that produce lots of magnifications and minimizations like the virtual reality world. We implemented our algorithm both two dimensional and three dimensional devices. Our algorithm does not produce any artifacts, jaggy or blurred result regardless of scaling factor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.8-14
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• 2009

To prevent the food poisoning originated by consumption of shellfish contaminated with domoic acid, the quantitative analysis of domoic acid is to be very important. The stability of domoic acid at different temperature, pH and light was investigated using high performance liquid chromatography (HPLC). The mean recoveries of domoic acid in the methanol extracts from oyster (Crassostrea gigas), blue mussel (Mytilus edulis), short neck clam (Ruditapes philippinarum) and ark shell (Scapharca broughtonii) were 85.4-104.5%, 94.8-101.2%, 91.0-104.6%, and 95.7-109.6%, respectively. The working solutions of domoic acid standard were very stable for one month at $-18^{\circ}C$, $4^{\circ}C$, and room temperature. And domoic acid in the methanol extract from oyster was stable for a day at $4^{\circ}C$ and room temperature, and for a week at $-18^{\circ}C$. Therefore, this implies that quantitative analysis for domoic acid must consider the storage conditions of the standard solutions and the methanol extracts from shellfish. The standard solutions adjusted to pH 3-9 were also stable after heating at $121^{\circ}C$ for 30 min. The effect of light exposure on domoic acid was tested by exposing the methanol extracts to light. Domoic acid degraded slowly when the samples were kept in the dark (brown vial). However, following the light exposure the photodegradation became more rapid; no detectable domoic acid remained in $1.0{\mu}g/mL$ of methanol extract after 5 hours.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.9
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• pp.708-713
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• 2010

In this research a ring light was developed so that a partial shadowless shooting for the patient's affected area at the medical treatment room and surgical operation room using high luminance light emitting diode (LED) for which attention is being paid as new lighting parts for medical purpose. LED which was applied to the development used high luminance three color LED for full color for which various color materialization and the adjustment of radiation intensity are possible and we can get white light in order to emphasize the delicate expression for generic tone of shooting object, strong highlight, simple shadow and three dimensional effect at the time of close-up shadowless shooting of the affected area. And at the time of design of ring light, the characteristics of LED and the loss of light at the time of penetrating light diffusion PC were considered so that intensity of illumination for over 150 lx can be obtained. The result of measurement of the intensity of illumination of the ring light that was developed revealed that maximum intensity of illumination of 225.7 lx was obtained, while smoke index was measured to be maximum 78 Ra in the case of Red(50%) Green(100%) and Blue LED(60%). We could confirm that response speed was also very fast as 1.72 ms.

• Journal of Powder Materials
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• v.27 no.3
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• Journal of the Korean Electrochemical Society
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• v.23 no.1
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• pp.11-17
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• 2020

The Prussian blue analogues of Fe₂(CN)₆ and Na_xFe₂(CN)₆ are prepared by precipitation method and evaluated the electrochemical characteristics as positive electrode materials for lithium-ion batteries (LIBs) because of their low cost. Fe₂(CN)₆ shows a low reversible capacity of 34.6 mAh g^-1, whereas sodium-containing Na_xFe₂(CN)₆ exhibits a reversible capacity of 107.5 mAh g^-1 when the discharge process proceeds first. When charging is first carried out to remove sodium in the structure, the reversible capacity of 114.1 mAh g^-1 is achieved and the cycle performance is further improved. In addition, Na_x-Fe₂(CN)₆ is synthesized at 0℃, room temperature (RT), and 60℃, respectively. Regardless of the synthesis temperature, Na_xFe₂(CN)₆ shows similar initial reversible capacity, but the crystallite size is formed smaller and improved cycle performance when synthetic temperature is lower. The sample synthesized at 0℃ shows a reversible capacity of 86.4 mAh g^-1 at the 120^th cycle and maintains 76.8% of the initial capacity.