• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.471-474
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• 2002

This experiment was conducted to investigate the response of rice growth and grain yield to night illumination. Three cultivars Heugjubyeo (early maturing), Hwaseongbyeo (medium maturing), and Ilpumbyeo(mid-late maturing) were tested under different light intensities ranging 1.0 to 20.0 lux (0.3 to 5.6 $1\mu\textrm{W}$ $cm^{-2}$). Awn length of all cultivars became longer as night illumination intensity increased; 4.09 cm under 10-20 lux compared to 1.93cm under 2 lux in Hwaseongbyeo. However culm and spike length ere not affected by night illumination. Night illumination delayed flowering by 3 days in Heugjinjubyeo, 5 days in Hwaseongbyeo, and 9 days in Ilpumbyeo at 10-20 lux compared to that at 2 lux. Grain yield was reduced by 10.0% in Heugjinjubyeo, 17.7% in Hwaseongbyeo, and 20.7% in Ilpumbyeo at 10-20 lux compared to 2 lux condition.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.132-141
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• 1996

The pixelated phase grating has been studied as a kind of diffraction gratings splitting and input beam into multiple spots. It consists of regular size cells which produce phase delays, and each cell provokes the phase delay up to sixteen levels. We have compared and analyzed the characteristics of multi-level phase gratings, laying streess on efficiency and resulted pattern. Experimental resutls obtained form fabricated grating have been presented, and the real-time method using a liquid-crystal spatial light modulator has been demonstrated through experiments. Gratings making meams with specific intensities have been designed and optical images have been generated by them. In order to specific intensities have been designed and optical images have been genrated by them. In order to decide the phase delay of each cell, optimization conditon consists of diffraction efficiency and target values. One period of phase gratings fabricated with surface relief was less than 256${\mu}m{\times}256{\mu}m$ and size of each cell was 1${\mu}m{\times}1{\mu}m$ surface relief grating has been made by coating photoresist on the glass plate, writing information pattern by Ar laser and developing it. in the experiment for real-tiem processing liquid-crystal display of epson video projector has been used.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.717-728
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• 1996

The effects of electro-acupuncture on the pain threshold and the amplitude of dEMG(di-gastric EMG) evoked by the noxious electric stimulation on teeth and gingiva in dogs were studied. Experiments were carried out with 10 dogs weighing 5-8kg. Each animal was anestheticed with Entobar given intraperitoneally in an initial dose of 30mg/kg. Maintenance dose of 5mg/kg/hr was given through a cannula, in the femoral vein, as required to keep up light anesthesia. Bipolar stimulating wire electrodes, 0.1mm in diameter, insulated except for tips, were inserted into the upper canine and palatal gingiva. Rectangular aluminium plate electrodes (15$\times$5mm) were placed on acupuncture points, called Yin-Hsiang, located at both sides of the upper jaw. Rectangular biphasic current pulses of 2Hz, with a $250{\mu}sec$ duration, were delivered for 15 minutes. The dEMG activities were recorded from the anterior belly of the digastric muscle(one of the jaw opening muscles) using bipolar wire electrodes. The magnitude of the jaw opening reflex at different intensties of electro-acupuncture(1volt 4volt and 10volt) was estimated by averaging the 30 superimposed dEMGs recorded on an oscilloscope and audiomonitor. Data were analysed statistically with ANOV A and paired t-test. The obtained results were as follows: 1. Pain thresholds were increased 7.7 %, 15.4 %, 17.3 % in the teeth and 11.1 %, 19.0 %, 25.4 % in the gingiva as the intensities of electro-acupuncture increased incrementally. 2. Amplitudes of dEMG were decreaed 8.3%, 22.4%, 27.4% in the teeth and 9.8%, 36.5%, 42.2 % in the gingiva as the intensities of electro-acupuncture increased incrementally. 3. Inhibition of pain responses by the electroacupuncture was more effective in the gingiva than in the teeth.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.569-577
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• 2019

The current experiment was conducted to compare nutrient utilization in the aged laying hens with different eggshell strengths or different intensities of brown eggshell color. Two metabolic trials with 96-week-old Hy-Line Brown laying hens were conducted. Twelve hens with a strong eggshell strength (SES) and 12 hens with a weak eggshell strength (WES) were selected and used in the first experiment, whereas 12 hens with dark brown eggshells (DBE) and 12 hens with light brown eggshells (LBE) were selected and used in the second experiment. All hens were fed a common commercial layer diet. Diets included chromic oxide as an indigestible marker to determine the apparent total tract retention (ATTR) of the gross energy (GE), dry matter, acid-hydrolyzed ether extract, nitrogen, neutral detergent fiber, acid detergent fiber, ash, and minerals. The results indicate that the ATTR of Ca in the aged laying hens with SES (59.7%) was greater (p < 0.05) than in the aged laying hens with WES (48.6%). However, the ATTR of the GE and other nutrients was not different between the hens with SES or WES. There were no differences in the ATTR of GE and nutrients between the hens with DBE or LBE. In conclusion, aged laying hens with SES have a greater ability to utilize dietary Ca than those with WES, indicating that the extent of dietary Ca utilization determines the eggshell strength of aged laying hens. However, nutrient utilization in diets may have little impact on eggshell brown coloration in aged laying hens.

• Journal of Photoscience
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• v.9 no.2
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• pp.41-43
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• 2002

In photoreceptor cells, light activates visual pigments consisting of a chromophore (retinal) and a protein moiety (opsin). Activated visual pigments trigger an enzymatic cascade, called phototransduction cascade, in which more than ten phototransduction proteins are participating. Two types of vertebrate photoreceptor cells, rods and cones, play roles in twilight and daylight vision, respectively. Cones are further classified into several subtypes based on their morphology and spectral sensitivity. Though the diversities of vertebrate photoreceptor cells are crucial for color discrimination and detection of light over a wider range of intensities, the molecular mechanism to characterize the photoreceptor types remains unclear. We investigated the amino acid sequences of about 50 vertebrate opsins, and found that these sequences can be classified into five fundamental subfamilies. Clear relationships were found between these subfamilies and their characteristic spectral sensitivities. In addition to opsins, we studied other phototransduction proteins. The amino acid sequences of phototransduction proteins can be classified into a few subfamilies. Even though their spectral sensitivity is considerably different, cones fundamentally share the phototransduction protein isoforms which are different from those found in rods. It is suggested that the difference in phototransduction proteins between rods and cones is responsible for their sensitivity to light. Isoforms and their selective expression may characterize individual photoreceptor cells, thus providing us with physiological functions such as color vision and daylight/twilight visions.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.58-64
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• 1997

$H_2$ production by Chromatium sp., a large purple sulfur bacterium blooming in lake Kaiike, under various environmental conditions was examined. Chromatium sp. produced $H_2$ only in the presence of light and $H_2$. Maximum $H_2$ production ($0.01\;{\mu}mol/hr/(mg\;dry\;cell\;weight)$) was obtained in the solution of 20 mg $H_2S-S/l$ under low light intensity (1000 lux) at $30^{\circ}C$. $H_2$ production was severely inhibited by the presence of $N_2\;or\;NH_4^+$. The rate observed for Chromatium sp. was relatively low compared to that of other phototrophic bacteria. Chromatium sp. is probably a most potent Ha producing species in lake Kaiike, since the bacterium readily produced $H_2$ photoautotrophically even at low light intensities by the application of suboptimal $H_2$ concentrations. Based on the photoautotrophic characteristics of bacterial $H_2$ production, it is suggested that Chromatium sp. can be an economic and practical species for biological $H_2$ production system, particularly in temperate region.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.710-716
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• 2017

New white-light-emitting $SrSnO_3:Dy^{3+}$ phosphors were prepared using different concentrations of $Dy^{3+}$ ions via a solid-state reaction. The phase structure, luminescence, and morphological properties of the synthesized phosphors were investigated using X-ray diffraction analysis, fluorescence spectrophotometry, and scanning electron microscopy, respectively. All the synthesized phosphors crystallized in an orthorhombic phase with a major (020) diffraction peak, irrespective of the concentration of $Dy^{3+}$ ions. The excitation spectra were composed of a broad band centered at 298 nm, ascribed to the $O^2-Dy^{3+}$ charge transfer band and five weak bands in the range of 350~500 nm. The emission spectra of $SrSnO_3:Dy^{3+}$ phosphors consisted of three bands centered at 485, 577, and 665 nm, corresponding to the $^4F_{9/2}{\rightarrow}^6H_{15/2}$, $^4F_{9/2}{\rightarrow}^6H_{13/2}$, and $^4F_{9/2}{\rightarrow}^6H_{11/2}$ transitions of $Dy^{3+}$, respectively. As the $Dy^{3+}$ concentration increased from 1 to 15 mol%, the intensities of all the emission bands gradually increased, reached maxima at 15 mol% of $Dy^{3+}$ ions, and then decreased rapidly at 20 mol% due to concentration quenching. The critical distance between neighboring $Dy^{3+}$ ions for concentration quenching was calculated to be $9.4{\AA}$. The optimal white light emission by the $SrSnO_3:Dy^{3+}$ phosphors was obtained when the $Dy^{3+}$ concentration was 15 mol%.

• Journal of Astronomy and Space Sciences
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• v.17 no.1
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• pp.39-44
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• 2000

We reinvestigate UV line emissions of 44i Boo, W UMa, AW UMa and VW Cep, which are indicaters of chromospheric activity of these stars. C I, C II, C IV, Si IV lines show significant variation in orbital phase. Among those lines, the Line of C IV showed the strongest line flux. while other Si IV and N V lines showed relative low line intensities. 44i Boo emitted the strongest flux than other stars. UV light curves of target stars shoed UV maximum at phase around 0.2 an 0.8 Such UV emissions are generally believed to be observed at the active regions and contacting parts of the two stars due to the clear visibility at the phase 0.2 and 0.8. Total emissivity of four transitions lines lead to conclude that the activity of this region is 40 times larger than the quiet sun. It is obvious that the activity decrease according to increase period. We obtained also Mg II light curve of AW UMA and VW Cep. These stars showed more clearly phase-dependent light curves. We estimated effective temperature of two star, AW UMa and VW Cep, using by Mg II flux.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.291-296
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• 2014

Inserting a $SiO_2$ layer underneath the p-pad electrode as the current blocking layer (CBL) structure and extending p-metal finger patterns, the GaN LEDs using an indium-tin-oxide (ITO) layer show the improved light output intensity, resulting from better current spreading and reduced light loss on the surface of p-pad metal. The LEDs with an oxide layer of $100{\mu}m$-pad-width and $6{\mu}m$-finger-width have better light output intensities than those with an oxide layer of $105{\mu}m$-pad-width and $12{\mu}m$-finger-width. Using the ATLAS device simulator from Silvaco Corporation, the current density distributions on the active layer in CBL LEDs have been investigated.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.292-301
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• 2014

Akinete germination may be a starting point of some akinete-producing cyanobacterial blooms in eutrophic freshwater systems. This study examined germinability of akinete of a cyanobacterium Anabaena circinalis isolated from the sediment of the North Han River (Cheongpyung Dam), Korea, under several environmental factors such as temperature ($5{\sim}25^{\circ}C$), light ($0{\sim}100{\mu}mol\;photons\;m^{-2}\;s^{-1}$), nutrients (nitrogen and phosphorus) and pH (5~12). The high germination rate appeared at high temperature: >55% at $25^{\circ}C$, followed by 15% at $15^{\circ}C$, $10^{\circ}C$ and 10% at $5^{\circ}C$. Low light intensity was favorable for akinete germination. Over 45% of germination occurred at low light intensities (5, 15 and $30{\mu}mol\;photons\;m^{-2}\;s^{-1}$), while less than 10% of germination occurred at both 50 and $100{\mu}mol\;photons\;m^{-2}\;s^{-1}$. No germination occurred in the dark condition. Akinete germination rate increased with nutrient (phosphorus and nitrogen) enrichment, and nitrogen addition showed greater effect on the germination compared to phosphorus addition. Akinetes germinated well at neutral or slightly alkaline pH condition (pH 7 and pH 8: >55%), but no germination was observed at pH 11~12. The present study demonstrates some favorable ambient conditions of Anabaena circinalis germination, which could provide useful information to study the germination conditions of other Anabaena species or akinete-forming algae and predict its bloom in eutrophic freshwaters.