Earticle

Dihydrotetraphenylgermole has been synthesized from the reduction of dichlorotetraphenylgermole with lithiumaluminiumhydride. UV-Vis absorption and photoluminescence was measured by using UV-Vis and fluorescence spectroscopy. Nanoparticles of dihydrotetraphenylsilole were synthesized from the mixture solution of water and THF. Photoluminescence behavior of organogermanium nanoparticle was investigated at various water fractions. Critical fraction of water to form organogermanium nanoparticles was 60%. Photoluminescence intensity of organogermanium nanoparticle was increased as the concentration of organogermanium nanocolloids increased. Photoluminescence efficiency of organogermanium nanoparticle at 90% water fraction increased about 100 times compared to that of molecular state.

Purpose: To determine the effects of 630 nm light emitting diode (LED) on full-thickness wound healing. Methods: Twelve male Sprague-Dawley rats were randomly divided into LED (n=6) and control group (n=6). Two $19.63mm^2$ wounds were created on the mid dorsum. LED group received a 630 nm LED irradiation with $3.67mW/cm^2$ for 30 minutes ($6.60J/cm^2$) for 7 days, while control group received sham LED irradiation. Epithelial gap, collagen density, ${\alpha}$-SMA fibroblast and PCNA keratinocyte were measured on histochemical and immunohistochemical staining using image analysis system. An independent t-test was conducted to compare the difference between groups. Results: The wound closure rate, collagen density, ${\alpha}$-SMA fibroblast number, epithelial gap and PCNA keratinocyte number have shown no significant difference between LED and control group at day 3 after the treatment. At day 7 after the treatment, the wound closure rate in LED group was increased when compared with control group (p<0.05). The collagen density (p<0.05) and ${\alpha}$-SMA immunoreactive fibroblast number (p<0.001) were increased when compared with control group at day 7. The epithelial gap in LED group was significantly shorten than control group at day 7 (p<0.01). The PCNA positive cell number in LED group was higher than control group at day 7 (p<0.01). Conclusion: 630 nm LED with $3.67mW/cm^2$, $6.60J/cm^2$ accelerate collagen deposition by stimulating fibroblasts, and enhance wound contraction by differentiating myofibroblasts in the dermis, and accelerate keratinocyte proliferation by facilitating DNA synthesis in the epidermis. It may promote the healing process in proliferation stage of wound healing.

Recovery of gallium and indium from waste light emitting diodes has been emphasized gradually owing to high content of gallium and indium. This study was established the recovery of gallium (Ga3+ ) and indium (In3+ ) from waste gallium nitride was contained in waste light-emitting diodes. The procedure was divided into the following steps; characteristic analysis, alkaline roasting, and leaching. In characteristic analysis part, the results were used as a theoretical basis for the acid leaching part, and the chemical composition of waste light emitting diodes is 70.32% Ga, 5.31% Si, 2.27% Al and 2.07% In. Secondly, with reduction of non-metallic components by alkaline roasting, gallium nitride was reacted into sodium gallium oxide, in this section, the optimal condition of alkaline roasting is that the furnace was soaked at 900°C for 3 hours with mixing Na2CO3. Next, leaching of waste light emitting diodes was extremely important in the process of recovery of gallium and indium. The result of leaching efficiency was investigated on the optimal condition accounting for the acid agent, concentration of acid, the ratio of liquid and solid, and reaction time. The optimal condition of leaching procedures was carried out for 2.0M of HCl liquid-solid mass ratio of 30 ml/g in 32minutes at 25°C and about 96.88% Ga and 96.61% In were leached.

This study was designed to detect and measure the concentration of radioactivity of natural radionuclides ($^{238}U$, $^{232}Th$, $^{40}K$) and artificial radionuclides ($^{137}Cs$, $^{60}Co$) present in the drinking water of the city of Busan and surrounding areas in South Korea, and also to measure the absorbed dose of radiation caused by these elements in the residents so as to help better manage the risk that these radionuclides pose in the future. For the purposes of the study, a total of 42 samples of water were collected from three key water sources (19 samples of groundwater, 4 samples of tap water, and 19 samples of surface water) and their contents were analyzed for radioactivity concentration. The results revealed that two natural radionuclides, $^{238}U$ and $^{232}Th$, exist in the groundwater with an average concentration of radioactivity of 3.34 Bq/L and $8.28{\times}10^{-5}Bq/L$ respectively, while the surface water was found to contain the same two radionuclides with mean concentrations of 0.849 Bq/L and $1.103{\times}10^{-4}Bq/L$ respectively. In addition, of the 19 samples of the groundwater, $^{137}Cs$ was found in eight of them and $^{60}Co$ was detected in ten. Of the four samples of the tap water, $^{137}Cs$ was detected in all samples and $^{60}Co$ was detected in three. Both $^{137}Cs$ and $^{60}Co$ were detected in all 12 samples of surface water. As far as $^{40}K$ is concerned, this element was detected in three of the 19 groundwater samples, but was not detected in any surface or tap water sample. In addition, the absorbed dose of $^{238}U$ from the groundwater was $7.94{\times}10^{-8}Sv/y$, while the absorbed dose of $^{232}Th$ from the surface water was $9.33{\times}10^{-13}Sv/y$. The absorbed dose of $^{137}Cs$ from the tap water was $7.33{\times}10^{-5}Sv/y$, while the absorbed dose of $^{60}Co$ from the surface water was the highest at $4.23{\times}10^{-6}Sv/y$.

Light is an important factor for cordycepin production in Cordyceps militaris. We investigated the effects of different light-emitting diode (LED) conditions including various LED wavelengths and their combinations on cordycepin production in Cordyceps militaris cultivated in submerged culture. The results of our study showed that the combinations of LED wavelengths were more beneficial than single LED sources for cordycepin production. Among the three tested wavelength combinations, the greatest effects for cordycepin production were observed for the red:blue light combination at the wavelength ratio of 5:5 or 3:7. The optimal culture conditions were 19.2278 h/day of illumination time; 9.19497 g/50 mL of glucose content in the media; and 53.112 h of cultivation time. Our model predicted a maximum yield of 2860.01 μg/mL cordycepin. Finally, to verify the calculated maximum, we performed experiments in the culture media representing the obtained optimum combination and the cordycepin yield of 2412.5 μg/mL.

We aim to elucidate suitable color of light during development of fruit body in Pleurotus eryngii. The four color of LED(Light Emitting Diode), blue LED(475nm), green LED(525nm), yellowed LED(590nm), and red LED(660nm), were irradiated for formation of fruit body after mycelia growth. First, as effect of color of LED at all growth stage, the morphological properties of fruit body in fluorescent lamp and blue LED irradiation were showed thicker and longer pileus than those in other color LED irradiation. The commercial yields in blue and green LED treatment were similar to control(Fluorescent lamp). Second, as effect of color of LED by light irradiation time, we could obtain the highest commercial yields at the green LED continuous radiation, 1/1 and 1/2(lighting/lighting-out, hours). And we could obtain the highest number of available stipes and biological efficiency at the 1/1(lighting/lighting-out, hours). The ergosterol was the highest under the green LED continuous radiation.

Environmental movements to return captured wildlife to nature are accelerating globally. From dolphins to killer whales, many species of marine organisms receive training to adjust to life in the wild. Different techniques can be utilized in behavioral training process including exposure to light sources (light training). Using classical training to teach Rasbora (Rasbora daniconius) to associate green light and food, other colors were tested to observe the optimum wavelength for behavioral training. Colored LED lights of blue, red, and white with short, long, and mixed wavelengths respectively were tested after complete training with green light which lasted ten days. The group of Rasbora was successfully trained to show feeding behavior when conditioned stimulus of green light was presented even in the absence of food. When introduced light of red and white, Rasbora showed feeding behavior almost identical to that of green light exposure. However, blue light elicited no clear feeding behavior in the group. As Rasbora have preference over light with long and mixed wavelengths such as red and white light, it can be inferred that red and white light is more effective in behavioral training. Blue light of short wavelength was found to be ineffective for detection of stimulus.The results demonstrated that the potential programs for returning wildlife back to nature can achieve success based on the understanding visual perceptions of marine animals such as those of rasbora.

From the time of the industrial revolution, fossil fuel has been the main source of energy, acting as a stimulant for many modernized industries. Despite the positive changes fossil fuel has brought to the mankind, it has produced carbon emission, facilitating the rising temperature of Earth resulting in global warming. Limited supply of fossil fuel has also hastened the search for alternative sources of energy. Biofuel from microalgae is recently gaining attention for its environmental friendliness, for example CO2 fixation during cultivation and high lipid content. Two strains of microalgae are used, Botryococcus braunii and Nannochloropsis oceanica, for their high potential as biofuel sources. Different colored settings of LED light, Green, Red, White, Blue, Red: Blue = 5:1, Red: Blue 3:1, Red: Blue = 1:1 were controlled to investigate the effects of mixture of colors on growth and lipid content of microalgae. Spectrophotometry and fluorescence spectrophotometry were used to measure the growth and lipid content of each microalgae strain. The experiment was conducted over the period of eight days, with measurements done on day 0,2,4,6, and 8. The optimum color of light differed slightly between strains, with B. braunii Red: Blue = 5:1 and N. oceanica red. The mixture of red and blue LED light had the better growth and lipid content than the single colored lights, red and blue mixed light with 18% more lipid content than white light in Botryococcus braunii. The ultimate light conditions for the cultivation of microalgae vary among species, but the best outcomes can be expected from using a mixture of red and blue lights. To find the optimum light ratio for each microalgae strain, further research and experiments using various ratio mixtures of red and blue lights are essential.

With the global energy crisis, many technologies in energy harvesting, such as solar, wind, geothermal, and hydraulic power plants, have been developed. This project envisioned to explore the potential of vibrations as a sustainable alternative source of energy through a simple and easy-to-make harvester. Piezoelectric materials that convert vibrations from human activities into energy were applied. A digital multi-meter was used to continually monitor the voltage output of the system. Three trials were done per monitoring. Actual testing to light emitting diode was also performed. Data showed that an output voltage was successfully generated. An average output voltage of 0.52V had a charging time of 20.56 seconds, 1.03V in 33.16 seconds, 1.52V in 60.52 seconds, 2.02V in 88.30 seconds, and 2.34V in 119.71 seconds. An average discharging time of 41.86 seconds per 1mV drop was also recorded. Results suggested that a fully charged device could have a theoretical continuous illumination of approximately 26 hours. In addition, the fabricated device successfully powered a light emitting diode for possible lighting purposes. The experiment established the viability of converting vibrations from human locomotion using a simple wooden box energy harvester and the potential of vibration as one of the most promising sources of energy for powering devices with low voltage electric requirements.

This study analyzes the government’s policy response through the case of ‘Radon-emitting mattress’, which is a radiation in the natural environment accident in Korea. And By reviewing cases of Radon management overseas, to draw up implications and suggest measures for efficient future government response. As a result, the first is that the criteria for Radon concentration control in everyday life were specified, Second, it operates information provision and education and training programs for Radon, third, training experts and fostering reliable institutions and private organizations, fourth, trying to identify the actual use of natural radioactive materials, and finally creating an environment in which members of society can be educated regardless of language. Based on these result, first, the sophistication of the relevant legal system, second, the re-establishment of the government's role as a control tower, third, distribution of processed products containing radioactive materials management and effective information management, fourth, the promotion of specialized institutions and finally the preparation of government measures for people-oriented.

This study was conducted to evaluate the effect of light spectrum using red (660㎚), blue (460㎚), red and blue mixed (Red : Blue = 6 : 4) LED (light-emitting diode), and fluorescent lamp on antioxidant activities and functional components of dandelion (Taraxacum officinale). Total polyphenol contents in dandelion irradiated with the red and blue mixed or the red LED were 121.77㎎/100 g or 115.36㎎/100 g, respectively, which were greater than those in dandelion treated with blue LED and fluorescent lamp. Asparagine showed the highest content among amino acids in leaves and roots regardless of treatments. Total amino acid was the highest when illuminated with the red LED. DPPH (1,1-diphenyl-2-picrylhydrazyl)radical-scavenging activity and SOD (super oxide dismutase) activity of ethanol extracts were increased under all of the LED treatments compared with fluorescent lamp, and the antioxidant activities were increased by the red and the mixed LED illumination. The results indicate that application of the red and the mixed LED illumination promote antioxidant activity and increase functional components during cultivation of dandelion.

Solution processed conjugated molecules enable to manufacture various electronic devices by unconventional and cost effective patterning methods as screen or gravure printing. Spin-coating is the most popularly used method to form conjugated polymeric film for various electronic devices. The coating method has certain disadvantages such as a large amount of unwanted wastes, difficulty forming a film with a large area, and impossible to apply roll-to-roll manufacturing. We present here a promising alternative coating method, bar-coating for conjugated polymer film and OLED with the bar coated light emitting layer. In this papers, we show atomic force microscope images of spin- and bar-coated Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (F8BT) films on substrate. The bar-coated film showed a slight lower RMS roughness (1.058 [nm]) than spin-coated film (1.767 [nm]). It means the bar-coating is suitable method to form light emitting layers in OLEDs. By using bar-coating process, an OLED obtained with 4.7 [cd/A] in maximum current efficiency.

In Projection Stereolithography Apparatus (PSLA), Digital Micromirror Device (DMD) and Liquid Crystal Display (LCD) are used as a beam pattern generator. The DMD shows high resolution, but it is mostly applied in micro stereolithography due to high cost and fabricable area. In LCD, the size of pattern beam is freely controlled due to various panel sizes. The LCD, however, has some limitations such as short life time by the high power light source, non-uniform light intensity of pattern beam and low transmittance of UV-light. To solve these problems in LCD-based PSLA, a Scanbeam-SLA with LCD of 19 inches and visible LED-array is developed. In this system, the light module works like a scanner for uniform illumination. The system configuration, working principle and fabrication examples are addressed in this study.

Thelightemittingplasma(LEP)hasrecentlyattractedattentionasanovelartificiallightsourceforplantgrowthandfunc- tionalcomponentenhancement.WeinvestigatedtheeffectsofLEPonwhiteningandantioxidantactivitiesoftheplantpartsofperilla. Methods and Results: Previously germianted seeds of perilla were cultivated under different light conditions (fluoresce lamp, LED red, blue, white, green, and LEP) in a culture room for 2 months. Parts of perilla were harvested and extracted in 70% EtOH. The extracts were used to detect total phenolic contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis- 3-ethylbenzothiazoline-6-sulfonicacid (ABTS),reducingpowerandtyrosinaseinhibitionactivity asindicatorsofbiologicalactivity. Biological activity was highest in seedlings grown under LEP. The total phenolic content was highest in the stems and the total fla- vonoid content was highest in the roots of perilla exposed to LEP. The DPPH and ABTS radical activity in all the parts of perilla exposed to LEP were higher by approximately three-fold compared to that in the control (fluoresce lamp). The reducing power val- ues of perilla significantly increased after treatment with LEP. In addition, all the extract of perilla plants exposed to LEP promoted the tyrosinase inhibitory activity. These results suggest that LEP can be an important artificial light source for enhancement of bio- logical activity. Conclusions: LEP could promote whitening and antioxidant activity of perilla.

Organic light-emitting diodes (OLEDs) using microcavity effect have attracted great attention because they can reduce the width of emission spectra from organic materials, and enhance brightness from the same material. We demonstrate the simulation results of the radiation properties from top-emitting organic light-emitting diodes (TE-OLEDs) with microcavity structures based on the general electromagnetic theory. Organic materials such as N,N'-di (naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) ($Alq_3$) as emitting and electron transporting layer are used to form the OLEDs. The organic materials were sandwiched between anode such as Ni or Au and cathode such as Al, Ag, or Al:Ag. The devices were characterized with electroluminescence phenomenon. We confirmed that the simulation results are consistent with experimental results.

디스플레이 광원으로서 다양하게 적용되고 있는 발광다이오드 기반의 반도체 광원에서 발광 효율은 매우 중요한 광학적 특징이며, 이러한 발광 효율 향상을 위하여 다중양자우물층을 포함하는 다양한 연구 방법이 제시되 어져 왔다. 하지만 이러한 효율 향상은 기본적으로 평면 구조에 기반을 두고 있음에 따라 광학적 특성 향상에 제 약이 되어 왔다. 본 연구에서는 실리콘 산화물의 미세 패턴과 이를 이용한 에칭을 통해 나노 홀을 형성하고자 하 였다. 또한, 실리콘 산화물의 나노 홀과 이를 통한 나노 크기의 원주형 구조를 구현할 수 있으며, 이러한 나노 원 주 구조에 발광층을 증착시킴에 따라 나노 크기의 발광 구조를 가지는 반도체 광원을 제시하고자 한다.

In a light emitting diode-based semiconductor light source that is variously applied as a display light source, luminous efficiency is a very important optical property, and various research methods including multiple quantum wells have been proposed to increase the luminous efficiency. However, since the efficiency improvement is basically based on the planar structure, there was a limit to the improvement of optical properties. In this study, nano holes were formed through micro patterns and etching of silicon oxide, different from the conventional structure are proposed. In addition, it is possible to implement a nano sized columnar structure through nano holes of silicon oxide, and by depositing a light emitting layer on the nano structure, it is intended to present a semiconductor light source having a nano-sized light emitting structure.

본 연구는 사용자 요구를 기반으로 손동작 인식과 터치 기반 발광 기능을 갖춘 안전 장갑을 설계 및 개발 하고, 사용자 평가를 통해 시스템의 기술적 성능과 사용성을 평가하는 것을 목적으로 한다. 기존의 보호 장갑 은 스위치 기반 작동으로 직관성이 낮아 야간 활동 및 작업 환경에서 즉각적인 안전 확보에 한계가 있었다. 이를 개선하기 위해 본 연구에서는 보행자와 라이더 총 257명을 대상으로 수요 조사를 실시하였으며, 분석 결과 약 45%가 야간 활동 중 불안감을 느끼고 71%가 자신의 시인성이 낮다고 인식하였다. 본 연구에서는 사용자의 기본 및 응용 손동작 메커니즘을 분석하고, 이를 기반으로 14개의 1차 디자인 선호도 조사를 거쳐, 최종 3개의 디자인으로 프로토타입을 완성하였다. 제작된 프로토타입은 사용자 10명을 대상으로 기술 평가 와 디자인 평가를 수행하였다. 그 결과, 기술 평가 부분에서 시스템 신뢰성 4.3점, 직관적 인터페이스 4.5점으 로 높은 성능과 일관성을 보였으며, 디자인 평가 부문에서 착용성 4.0점, 실용성 4.1점, 독창성 3.6점으로 나타 났다. 본 연구는 사용자 수요와 손동작 기반 메커니즘을 설계에 반영하고, 예비 사용자를 대상으로 기술·디자 인 평가를 통해 기능성과 사용성을 동시에 검증한 데 의의가 있다. 특히, 스위치가 없는 접촉 기반 작동 메커 니즘과 사용자 경험을 반영한 직관적 설계를 통해 착용 편의성과 시스템 활용도를 크게 향상시킨 기술적 기여가 있으며, 이는 위급 상황에서 안전을 확보하는데 필요한 시간을 단축할 가능성을 제시한다. 최종적으 로 본 연구는 야간 활동과 다양한 직종의 작업 환경에서 사고 예방 및 시인성 향상을 지원하는 실용적인 웨어러블 솔루션으로 평가된다.

The purpose of this study is to design and develop gesture-recognizing and touch-based light-emitting safety gloves based on user requirements, and to evaluate the system's technical performance and usability through user assessment. Conventional protective gloves, relying on switch-based operation, inherently lack intuitiveness, which limits the potential for immediately securing safety in nighttime or occupational environments. To address this, a demand survey was conducted with 257 pedestrians and riders, revealing that approximately 45% felt insecure during nighttime activities and 71% reported low visibility. The study analyzed users’ basic and applied hand movement mechanisms, produced 14 preliminary designs for user preference evaluation, and finalized three designs, from which the prototypes were produced. Technical and design evaluations were conducted with 10 participants. Results indicated high technical performance, with system reliability scoring 4.3 and intuitive interface scoring 4.5, while design evaluations scored 4.0 for wearability, 4.1 for practicality, and 3.6 for originality. This research is significant in that it integrated user demand and gesture-based mechanisms into the design, and simultaneously verified functionality and usability through preliminary user evaluation. Specifically, the switch-free, touch-based operation mechanism and the intuitive design reflecting user experience offer a significant technical contribution by substantially enhancing wearability and system usability. This mechanism, compared to switch-based methods, suggests the potential to reduce the time required to secure safety in critical situations. Ultimately, the findings are evaluated as providing a practical wearable solution that supports accident prevention and visibility enhancement in nighttime activities and various occupational settings.

In this study, a mixed resin containing Bis-GMA was developed to produce a light-emitting sign using quantum dots. As a result of measuring the viscosity, color coordinates change, and luminance of the mixed resin, the following conclusions were obtained. The viscosity of the mixed resin decreased as the content of the diluent increased, and viscosity values ​​ranged from 3,627 to 1,349cps showed as a result. The viscosity of the mixed resin decreased as the temperature increased, and the viscosity showed a value of 5,156 to 1,132cps. For the optical properties of InP/GaP/ZnSe/ZnS quantum dots, the absolute quantum efficiency was 91% at 522nm and 90% at 618nm when the gallium was 0.01%. The luminance of the light-emitting sign using the resin mixed with quantum dots was showed 142.6cd/m2 in white and 104.2cd/m2 in the red region.

본 연구는 키네틱 발광 오브젝트 제어 장치 및 이를 위한 방법에 관한 것으로 BMW Korea의 의뢰를 받아 제작하게 된 작품이다. 연구에서 설명하고 있는 작품은 BMW Korea 드라이빙센터의 설치를 목적으로 하고 있으며 현제 프로토타입 제작이 완료된 상태이다. 본 연구는 다수의 그룹으로 이루어진 다수의 오브젝트와, 그것을 이용하여 형상을 나타내기 위해 다수의 그룹 각각에 대응하는 메인 제어 신호를 전송하는 메인제어부와, 메인 제어신호에 따 라 상기 다수의 그룹 중 대응하는 그룹의 오브젝트 각각에 대응하는 서브 제어 신호를 전송하는 다수의 서브제어부 와, 서브 제어 신호에 따라 다수의 오브젝트 각각과 연결된 와이어의 길이를 조절하는 다수의 구동부를 포함하는 것 을 특징으로 하는 키네틱 발광 오브젝트 제어 장치와 이에 따른 방법에 관한 연구이다.

This study is on kinetic light-emitting object control systems and the methodologies for research. The study explores the methodologies for researching and findings on kinetic light-emitting object control systems, which consist of multiple objects comprising multiple groups; the main control section that transmits the main control signals that correspond to each of the groups in order to display forms using multiple objects; multiple sub control sections that transmit sub control signals in correspondence to each of the objects in the corresponding groups from the above in accord with the main control signal; and multiple driving parts that control the length of the wires connected to each of the multiple objects according to the sub control signal.