• Carbon letters
• /
• 제11권3호
• /
• pp.206-210
• /
• 2010

Removal of dyes Reactive Blue 221, N Blue RGB and Acid Blue MTR using two different samples of activated carbon by static batch method was studied. Experimental data on optical density of solutions at different concentrations ranging from 10 to 100 mg/L and of solutions after adsorption on activated carbon samples were measured. Calibration curves were plotted and the amount of dye $q_e$ adsorbed was calculated. The data was fitted to Langmuir and Freundlich isotherms for two different carbon samples and different concentration and pH values. Constants were calculated from the slope and intercept values of the isotherms. Coefficient of correlation $R_2$ and Standard Deviation SD were also noted. The data fitted well to the isotherms. Carbon sample $C_1$ showed higher potential to adsorb all the three dyes. Adsorption was higher at lower concentrations. Carbon sample $C_2$ showed better adsorption in acidic pH as compared to in alkaline pH. From the analysis of the data capacity of $C_1$ and $C_2$ to remove the dyes from water have been compared.

• 한국결정학회지
• /
• 제12권1호
• /
• pp.5-9
• /
• 2001

Nd/sub 0.05/Y/sub 0.95/Ca₄O(BO₃)₃(Nd:YCOB) single crystals were grown by the Czochralski method using a iridium crucible under N₂ atmosphere. Optimum growth parameters to get high quality of single crystals were 1.5∼2 mm/hr of growth rate and 10∼20 rpm of rotation rate. The grown crystals were transparent with light purple color and well-developed in cleavage planes. The crystal structure of Nd;YCOB were identified to monoclinic by XRD method. Crystal defects acting as light scattering centers, such as micro-pores, secondary phases, inclusions and cracks were not observed under the He-Ne laser illuminations. Three red, green, blue laser devices for the RGB laser oscillations were designed and then fabricated from the grown Nd:YCOB crystals according to the phase-matching angles of negative type-I which were φ=16.40°, 33.95° and θ=22.59° with the flatness of λ/6 at least, respectively.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.198-198
• /
• 2003

LED(Light Emitting Diode)는 전기 신호를 빛으로 신호를 보내고 받는데 사용되는 반도체의 일종으로 가정용 가전제품, 리모컨, 전광판, 각종 자동화 기기등에 사용된다. 3색광 백색 LED는 soft-UV 또는 blue 빛을 내는 device 와 RGB 형광체로 이루어져 있다. 현재 연구중인 3색광 백색 LED는 InGaN 또는 GaN 이 RGB 형광체를 여기 시키는것이 대부분이다. 이러한 경우에 유기물과 무기물 형과체가 백색광을 구현하기 위해 사용된다. 유기물의 경우에는 lift-time 이 짧고, 무기물의 경우에는 유해원소인 S, Cd등이 포함되기 때문에 환경오염이 야기된다. 이러한 단점을 보완하기 위해 진화 최적방법을 이용하여 alkali earth borosilicate ((Eu,Mg,Ca,Sr,Ba)$_{x}$ $B_{y}$ S $i_{z}$ $O_{d}$ ) 계열에 $^{Eu3+}$을 도핑하여 고효율 형광체를 합성하였다.

• 한국레이저가공학회지
• /
• 제14권2호
• /
• pp.24-29
• /
• 2011

The design of a telecentric f-${\theta}$ lens with a field of view (FOV) $30^{\circ}$ and an effective focal length of 1000mm is presented. The optical stop is placed at the front plane and the design is based on a geometric ray tracing technique, and the designed system consists of a series of convex and concave lenses. The designed f-${\theta}$ lens showed a considerable reduction in weight with a simplified structure and resulted in a good performance in the designated FOV. Detail analysis of rays is also presented. 653nm (red laser), 586nm (green laser), and 468nm (blue laser) were simulated as a light source and image illuminating source. The developed optical design requires 7 pieces of lenses made of SF1, N-FK56, N-LAK33, and BK7 glass materials. With optimal parametric design, the effective focal length was calculated to be 974.839mm which is very close to the initial design target. For the manufacturing purpose, the dimensions of lens curvature and thickness were truncated with error ranging 0.1% to 3.2%. As a result, the overall error was calculated to be 3.2% which can be still tolerable for display, laser material, and machining processing.

• Carbon letters
• /
• 제9권1호
• /
• pp.1-7
• /
• 2008

The ability of cow dung ash without any pretreatment to remove color from textile dyes N Blue RGB, Green B and EOSIN YWS from aqueous solution has been investigated in this work. Cow dung ash, an ecofriendly and low cost adsorbent was prepared by burning cow dung cakes in the muffle furnace at $500^{\circ}C$. The adsorption was achieved under different pH and adsorbate concentration. The data was fitted to simple polynomial and the isotherms similar to Langmuir and Freundlich isotherms.

• The Journal of Korean Physical Therapy
• /
• 제23권1호
• /
• pp.45-51
• /
• 2011

Purpose: This study investigated the effect of needle electrode stimulation at various frequencies on change in wound healing in excision wound rats Methods: Twenty-four Sprague-Dawley adult male rats were assigned to one of four groups: control (n=6), acupuncture group (n=6), low rate (2 Hz) percutaneous electrical stimulation group, high rate (100 Hz) percutaneous electrical stimulation group (n=6). We analyzed morphological effects by measuring the area of the excision wound, the contraction rate, and chromatic red. A digital camera and an image analysis program were used to measure and analyze the wound area,which was also used for the contraction rate. Chromatic red was obtained by calculating red, green, and blue (RGB) values of the wound area. Results: The electro acupuncture stimulation groupsshowed significant healing effects compared to the control and acupuncture groups. Conclusion: The results of this study showed that various frequencies of percutaneous electrical stimulation have a therapeutic effect on wound healing.

• 한국염색가공학회지
• /
• 제13권6호
• /
• pp.39-39
• /
• 2001

The accurate representation of the colors of dyed fabric on a color CRT(cathode ray tube) screen is the basis for the automatic process in dyeing industry. In the former study, we had focused on the theoretically color matching method between CIE(International Commission on Illumination) and RGB color coordinates, but In this study we tried simulating the colors obtained from fabrics on the color CRT by using experimental method. we obtained the following results. 1. We could simulate all of the color CRT by gamut mapping method, even though some of the KOSCOTE(Korea Standard Color of Textile) colors represented on the color CRT didn′t exist in the region of color region. 2. We could do conditional matching by CIE system, even though it was hard to do invariant matching the Red, Green, Blue phosphers of the color CRT because of the SPD(Spectral Power Distribution) which had been set up before. 3. We could simulate all the colors obtained from fabrics on the color CRT by matching those two color groups from KOSCOTE fabrics and color CRT using match algorithm and matching programs. 4. If we get over on obstacles by grafting CCM and CCK machines which have been used in educational and industrial areas by matching KOSCOTE with color CRT we will be able to invent color simulation system controled automatically.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1583-1586
• /
• 2006

All non-dopant white organic light-emitting diodes (WOLEDs) have been realized by using solid state highly fluorescent red bis(4-(N-(1- naphthyl)phenylamino)phenyl)fumaronitrile (NPAFN) and amorphous bipolar blue light-emitting 2-(4- diphenylamino)phenyl-5-(4-triphenylsilyl)phenyl- 1,3,4-oxadiazole (TPAOXD), together with well known green fluorophore tris(8- hydroxyquinolinato)aluminum $(Alq_3)$. The fabrication of multilayer WOLEDs did not involve the hard-tocontrol doping process. Two WOLEDs, Device I and II, different in layer thickness of $Alq_3$, 30 and 15 nm, respectively, emitted strong electroluminescence (EL) as intense as $25,000\;cd/m^2$. For practical solid state lighting application, EL intensity exceeding $1,000\;cd/m^2$ was achieved at current density of $18-19\;mA/cm^2$ or driving voltage of 6.5-8 V and the devices exhibited external quantum efficiency $({\eta}_{ext})$ of $2.6{\sim}2.9%$ corresponding to power efficiency $({\eta}_P)$ of $2.1{\sim}2.3\;lm/W$ at the required brightness.

• 한국작물학회지
• /
• 제65권4호
• /
• pp.377-385
• /
• 2020

적절한 질소 시비는 작물에 초형을 개선하는 한편, 엽록소 유지에도 도움을 주어 엽노화를 억제하고 광합성도 증대시켰다. 드론을 활용해 얻어진 잎의 RGB 값은 4월 29일에서 추비량 증가에 따라 RGB 값의 뚜렷한 차이를 나타내 단순한 엽색 분석도 작물의 생리적 상태 평가에 활용할 수 있음을 보여주었다. 휴대용 측정기를 이용한 실험에서 추비 조건에 따른 NDVI와 SPAD 값은 3월 19일에 큰 차이 확인할 수 없었다. 그러나 초분광카메라를 통한 분석에서 추비량 증대에 따라 780 nm보다 큰 파장대인 NIR 영역에서 반사율 증가가 확인되었다. 이는 시비 효과가 명확히 드러나지 않는 생육 초반에도 초분광카메라 활용해 작물 상태를 진단할 수 있음을 보여준다. 포장에서 추비 수준이 낮을수록 4월 29일에는 가시광선 영역의 반사율이 증가하고, NIR 영역의 감소가 확인되어 시비에 따른 영향을 확인할 수 있었다. 초분광카메라를 이용한 식생지수 확인으로 엽록소 함량, 질소 부족 정도, 광합성 상태 분석에 근거한 시비 효과 평가가 가능하였다.

• 대한인간공학회지
• /
• 제36권2호
• /
• pp.123-144
• /
• 2017

Objective: The objective of this study is to evaluate affection on how users perceive colors viewed from an automotive visual display according to cultural and radical differences including North America, Europe, and Southeast Asia. This study especially aims to identify effects of the variation of tone and chroma of representative color groups by analyzing affection differences depending on cultural and racial differences targeting the colors constituted through variation of tone and chroma, centered on representative colors. Background: The colors of the menu, information display or background viewed through an automotive visual display are an important factor stimulating consumer's affection, and therefore an effort to express the vehicle's brand and product image through colors is made. The studies on colors focus only on the research on unique characteristics of colors, but an affective approach lacks according to cultural and racial differences on colors considering tone and chroma variation within a color from the currently used automotive visual displays. Method: To grasp the visual affection felt by users, this study extracted affective adjectives related with colors through existing literature and a dictionary for adjectives, and presented human affection dimensions on colors through evaluation of various colors. Prior to carrying out affection evaluation, the basic light sources, red (R), green (G), and blue (B) constituting the colors used for automotive visual displays were defined as a representative color group, respectively. When colors in a color group are constituted, the evaluation target of each color group consisted of the colors considering the variation of tone and chroma by changing color sense through RGB values of the remaining two light sources. And then, this study carried out affection evaluation on the constituted colors targeting the subjects with cultural and racial differences. Results: As a result of evaluating the constituted colors with representative affections, there were statistically significant differences between the groups having cultural and racial differences. As a result of S-N-K post-hoc analysis on the colors showing significant differences, North America and Europe were classified as heterogeneous groups. In some cases, Korea was classified as the homogeneous group with North America, but Korea was mainly classified as the homogenous group with Europe. Conclusion: The representative affections on colors from an automotive visual display was drawn as three affective dimensions: passionate, neat, and masculine. Based on these, the affection of Korea and Europe on the constituted colors showed significant differences from that of North America, as a result of affection evaluation on the constituted colors viewed through the visual display by reflecting cultural and racial factors. Regarding representative color groups, bigger cultural and racial differences were revealed in terms of affection on red and green colors than on blue color, and variation of affection was the biggest in the red color. Application: This study analyzed correlations of affection considering the colors constituted through variation of tone and chroma, and the culture and race in the representative color groups constituting a visual display. The results of this study are predicted to be utilized in coordination and selection of colors viewed from an automotive visual display taking into account culture and race.