본 연구는 Tetraselmis suecica와 T. tetrathele의 영양물질 증진효과를 가져올 수 있는 배양시스템 구축을 위하여, 발광다이오드 (LED)의 파장별(청색; 450 nm, 황색; 590 nm, 적색; 630 nm) 탄수화물, 단백질, 지질 함량을 측정하였다. 두 종 모두 단백질 비율(42~69%)이 가장 높았으며, 생장속도가 낮았던 황색파장에서 탄수화물, 단백질, 지질의 높은 함량을 보였고, 생장속도가 가장 높았던 적색파장에서는 낮은 함량을 보였다. 이러한 결과는 세포 분열 속도의 감소로 인해 단백질 합성과 함께 세포의 화학적 조성과 효소 활동에 변화를 주어 지질과 탄수화물 함량이 증가한 것으로 생각된다. 따라서, T. suecica와 T. tetrathele의 유용한 생화학적 물질의 증대를 위해 대수생장기 초 기와 중기는 적색 LED 그리고 대수생장기 후기에는 황색 LED를 주사하는 2단계 LED 배양을 제안하였다.

‘Tracers’ are bullets that emit light at the backside so that the shooter can see the trajectory of their flight. These light-emitting bullets allow snipers to hit targets faster and more accurately. Conventional tracers are all combustion type which use the heat generated upon ignition. However, the conventional tracer has a fire risk at the impact site due to the residual flame and has a by-product that can contaminate the inside of the gun and lead to firearm failure. To resolve these problems, it is necessary to develop non-combustion-type tracers that can convert heat to luminance, so-called ‘thermoluminescence (TL)’. Here, we highly improve the thermoluminescence properties of MgB4O7 through co-doping of Dy3++Ce3+ and Dy3++Na+. The presence of doping materials (Dy3+, Ce3+, Na+) was confirmed by XPS (X-ray photoelectron spectroscopy). The as-synthesized co-doped MgB4O7 was irradiated with a specific radiation dose and heated to 500 °C under dark conditions. Different thermoluminescence characteristics were exhibited depending on the type or amounts of doping elements, and the highest luminance of 370 cd/m2 was obtained when Dy 10 % and Na 5 % were co-doped.

Understanding the light environment in greenhouse cultivation and the light utilization characteristics of crops is important in the study of photosynthesis and transpiration. Also, as the plant grows, the form of light utilization changes. Therefore, this study aims to develop a light extinction coefficient model reflecting the plant growth. To measure the extinction coefficient, five pyranometers were installed vertically according to the height of the plant, and the light intensity by height was collected every second during the entire growing season. According to each growth stage in the early, middle, and late stages, the difference between the top and bottom light intensity tended to increase to 69%, 72%, and 81%. When leaf area index and plant height increased, the extinction coefficient decreased, and it showed an exponential decay relationship. Three-dimensional model reflecting the two growth indexes, the paraboloid had the lowest RMSE of 1.340 and the highest regression constant of 0.968. Through this study, it was possible to predict the more precise light extinction coefficient during the growing period of plants. Furthermore, it is judged that this can be utilized for predicting and analyzing photosynthesis and transpiration according to the plant height.

Magnetically separable and reusable zinc ferrite/reduced graphene oxide ( ZnFe2O4/rGO) nanocomposite has been prepared by hydrothermal method. The results illustrate that the construction of ZnFe2O4 and rGO occur concurrently in a hydrothermal reaction that initiates the formation of rGO-wrapped ZnFe2O4 nanospheres. The morphological and structural features of the ZnFe2O4/ rGO nanocomposites reveal that the rGO nanosheets anchored to the ZnFe2O4 sphere act as a self-protective clamping layer to avoid the photo corrosion effect under photo irradiations. The nanocomposites express the soft magnetic behavior with high saturation magnetization under annealing temperature at 300 °C, which may attribute to the well-defined crystalline structure and surface defects. In addition, the GZF 300 nanocomposites exhibit the enhanced photocatalytic degradation over Rhodamine B dye which is 3.4, 1.15, and 1.32 times higher than that of ZF, GZF, and GZF 600 over under visible irradiation in 120 min. The GZF 300 nanocomposites demonstrate their ability to degrade RhB efficiently, even after several photocatalysis cycles with high catalyst recovery by its magnetically separable behavior. The high densities of oxygen defects improvise electron transfer from ZnFe2O4 to rGO and delay the recombination process of the nanocomposite, resulting in enhanced visible photocatalytic activity. The strong magnetic properties of rGO wrapped ZnFe2O4 nanocomposite catalysts the easy separation from the suspension system for multiple usages in water treatment.

국립원예특작과학원에서 2016년 거베라 신품종 ‘샤이핑크 (Shy Pink)’를 육성하였다. ‘Shy Pink’는 2008년 10월부터 2008년 11월까지 녹색 화심의 분홍색 반겹꽃 ‘프리존’과 갈 색 화심의 살구색 반겹꽃 ‘아틸리아’를 교배하여 획득한 실생 72개체 중에서 2009년부터 2016년까지 생육 및 개화특성검 정을 거쳐 선발한 절화용 대륜 거베라 품종이다. ‘샤이핑크 (Shy Pink)’는 화형이 안정적인 갈색 화심의 연분홍색(RHS R49A) 반겹꽃 대륜계 품종이다. 꽃은 평균 직경이 12.4cm이 고, 내부설상화와 화반의 직경은 각각 7.2cm와 2.3cm이다. 외부설상화의 길이와 폭은 각각 6.0cm와 1.2cm로 꽃잎이 좁은 도란형이다. 꽃대 직경은 상부 6.1mm, 중부 7.0mm 정 도로 강건하며, 꽃대의 길이는 48.9cm이다. 절화수명은 12.1 일로 대조구인 ‘하모니(Harmony)’ 12.0일로 유사하였지만 절 화수명이 길며, 연간 채화량은 52.8본/주로 다수성 품종이다.

Recently, halogen lamps for vehicle exterior lamp systems are being replaced by LEDs (Light Emitting Diode) in consideration of miniaturization, power consumption, life, luminance, and eco-friendliness. Due to regulations on the amount of light required, luminance, light uniformity, and glare prevention, it is required to develop a light guide for controlling a light source of an LED lamp for a vehicle. For the development of the light guides, the development of machining technology that can cut micro patterns of hundreds of micrometers scale into surface roughness of tens of nanometers scale must be preceded. In this study, the effect of variations in cutting conditions on surface roughness was analyzed through experiments. The micro patterns was manufactured by cutting into STAVAX material, and the surface of the micro patterns was super-finished using a ball-shaped PCD (polycrystalline diamond) tool without flutes. In experiments, the cutting conditions of the super-finishing process were varied, and the varied cutting conditions were feed rate, radial depth of cut, and spindle speed

N-doped Na2Ti6O13@TiO2 (denoted as N-NTO@TiO2) composites are successfully synthesized using a simple two-step process: 1) ball-milling of TiO2 with Na2CO3 followed by heat treatment at 900oC; 2) mixing of the prepared Na2Ti6O13 with titanium isopropoxide and calcining with urea at 500oC. The prepared composites are characterized using XRD, SEM, TEM, FTIR, and BET. The N-NTO@TiO2 composites exhibit well-defined crystalline and anatase TiO2 with exposed {101} facets on the external surface. Moreover, dopant N atoms are uniformly distributed over a relatively large area in the lattice of the composites. Under visible light irradiation, ~51% of the aqueous methylene blue is photodegraded by N-NTO@TiO2 composites, which is higher than the values shown by other samples because of the coupling effects of the hybridization of NTO and TiO2, N-doping, and presence of anatase TiO2 with exposed {101} facets.

Thermal protection systems (TPS) are a group of materials that are indispensable for protecting spacecraft from the aerodynamic heating occurring during entry into an atmosphere. Among candidate materials for TPS, ceramic insulation materials are usually considered for reusable TPS. In this study, ceramic insulation materials, such as alumina enhanced thermal barrier (AETB), are fabricated via typical ceramic processing from ceramic fiber and additives. Mixtures of silica and alumina fibers are used as raw materials, with the addition of B4C to bind fibers together. Reaction-cured glass is also added on top of AETB to induce water-proof functionality or high emissivity. Some issues, such as the elimination of clumps in the AETB, and processing difficulties in the production of reusable surface insulation are reported as well.

Low-cost particulate matter (PM) sensors based on the light scattering principle measure the concentration of particles by the change of scattering intensity after light is irradiated onto the particles. It has been reported that when the relative humidity is high, water vapor may cause the expansion of airborne particles and affect the accuracy of the light scattering method for PM measurement, but it has also been shown that the effect of humidity is not significant or even negligible. Therefore, to determine the effect of humidity on the Plantower PMS7003 light scattering sensor, in this study, a BAM1020 (Beta Attenuation Monitoring) was installed alongside to continuously monitor the ambient atmospheric PM concentration for approximately four weeks. The sensors collected data at 10-minute intervals, resulting in a 1-hour average for comparative analysis. To accurately measure humidity, the performance of the Arduino + DHT22 humidity sensor was also pre-evaluated using a series of saturated salt solutions. The humidity was grouped into five intervals and analyzed by visual analysis. The results confirmed that there was no significant correlation between PM2.5 differences and humidity, which were randomly and uniformly distributed around the mean. However, since in the very low and high concentration ranges based on the beta-ray monitor measurements, the difference between the light scattering sensor PM10 measurement and the reference value is much larger than the difference between the PM2.5 and the reference value., there is an additional need to investigate the appropriate correction method for dust season or PM10. The results show that the outcomes of the light scattering sensor are more influenced by particle size and concentration than by humidity.

작물 생육 진단에 있어서 군락 엽면적과 군락 피복은 주한 요소 이다. 최근에는 이러한 측정을 디지털 카메라를 활용하여 RGB 식생지수로 작물 생육을 측정하고 있다. 본 연구는 밀 재배 기간 카메라의 노출 값을 다르게 설정하여 RGB 컬러 식생 지수와 군락 엽면적지수 및 군락피복에 대해 평가하였다. 군락 엽면적, 군락 피복 및 디지털 영상 측정은 출수 16일전부터 출수 후 25일까지 하였다. 일출 후 30분 이내에 촬영하였다. 노출 값은 셔터 속도를3 수준(1/60s, 1/340s, 1/640s)으로 하였다. RGB 컬러 식생지수 분석은 파이썬으로 하였다. 실제 군락 엽면적과 군락 피복간에는 정의 상관관계(r2 =0.94)를 보였다. 군락 피복 이미지의 ExG, GLI, NGRDI, ExG-ExR, MExG, TGI, MNGRD 및 MExG-CIVE는 군락 엽면적 지수와 및 군락 피복과는 정의 상관관계를 보였다. 그러나 CIVE와 ExR은 부의 상관관계를 보였다. 본 연구 결과 1/640s 가 1/60s와 1/320s에 비하여 노출이 높게 설정된 것으로 보였다. 또한, 토양과 녹색 영역을 분리하는데 있어서 너무 어린 시기 보다는 출수 전이 가장 잘 분리되었다. 따라서 야외에서의 다양한 광 조건에서는 과도한 노출보다는 광 간섭을 줄이는 기술과 함께 작물의 생육 시기와 기상환경을 고려하여 노출 값이 설정되어야 할 것이다.

목적 : 반응성 청색광차단 염료를 하이드로겔 콘택트렌즈에 화학적으로 고정시켰고, 제조된 콘택트렌즈의 청색 광차단 기능의 분석 및 첨가된 염료를 정량하고자 한다. 방법 : Vinyl sulfone-기반의 반응성 염료인 Reactive Orange 16 Dye를 다량의 알콜 작용기를 함유하는 하 이드로겔 콘택트렌즈에 화학적으로 결합시켰다. 콘택트렌즈의 청색광차단 특성 및 염료의 정량은 UV-vis spectrophotometer를 이용하여 확인하였다. 결과 : 청색광차단기능의 Reactive Orange 16 Dye가 성공적으로 하이드로겔 콘택트렌즈에 결합되었다. UV-vis spectra 분석을 통해 염료를 함유한 콘택트렌즈들이 우수한 청색광차단 기능을 보임을 확인하였다. Beer-Lambert의 법칙을 이용하여, 콘택트렌즈에 첨가된 Reactive Orange 16 Dye를 정량하였으며, 반응 염료 의 농도 조절을 통해, 콘택트렌즈의 청색광차단율을 조절할 수 있었다. 결론 : 본 연구에서는 청색광차단 기능의 반응성 염료를 하이드로겔 콘택트렌즈에 화학적 결합을 통해 고정시 키고, 청색광차단 기능을 분석하였다. 화학적 반응에서 청색광차단 염료의 농도가 증가할수록, 380~500 nm 사 이의 청색광 파장 영역에서의 차단 세기와 첨가된 염료의 양이 같이 증가함을 확인하였다. 대량생산이 가능한 청 색광차단 콘택트렌즈의 개발은 기능성 안광학의료기기 개발에 큰 역할을 할 것으로 기대된다.

Wolfiporia cocos is an edible fungus commercially cultivated in Asia. To investigate metabolic changes of W. cocos mycelia under both light and dark culture conditions, gas chromatography mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) analyses were performed. In terms of the total amount of sugars, alcohols, amino acids, organic acids, fatty acids, and purines, there no significant differences between the W. cocos mycelia cultivated under light (L) or dark (D) conditions (p < 0.05). However, there were some differences with respect to the production of particular sugars and proteins. The levels of trehalose (L: 17.2 ± 0.3% vs. D: 13.9 ± 1.6%), maltose (L: 0.9 ± 0.1% vs. D: 0.3 ± 0.1%), turanose (L: 0.7 ± 0.2% vs. D: 0.1 ± 0.1%), glutamine (L: 1.6 ± 0.3% vs. D: 0.7 ± 0.2%), and proline (L: 0.3 ± 0% vs. D: 0.1 ± 0%) were all significantly higher under light condition (p < 0.05). In contrast, the levels of galactose (L: 13.7 ± 1.2% vs. D: 17.6 ± 2.0%), aspartic acid (L: 0.6 ± 0.1 % vs. D: 0.9 ± 0.1%), cystathionine (L: 0.6 ± 0.1% vs. D: 0.8 ± 0 %), and malic acid (L: 0.7 ± 0.1% vs. D: 1.2 ± 0.1%) were higher under the dark condition. It is worth noting that the amount of pachymic acid, a pharmaceutically active compound of W. cocos, was 1.68 times greater under the light condition (p < 0.05).

본 연구는 1960-70년대 서부 미니멀리즘의 작업 경향에서 드러난 지역성을 통해 이들의 독자성을 고찰하고자 한다. 서부 미니멀리즘은 로스앤젤레스 화단이 주체적으로 형성한 예술 운 동이라는 의의가 있다. 서부 미니멀리즘은 동시대 뉴욕 미니멀리즘과 유사성을 공유함에도 불구 하고, 이들은 로스앤젤레스의 지역성에 기반한 독자성을 형성하였다. 이들의 독자성이 구축되는 과정은 회화 매체를 주축으로 이루어졌으며, 이는 뉴욕 미니멀리즘과 구별되는 주요한 지점이다. 이에 본 연구는 서부 미니멀리즘의 지역성이 특히 이들의 회화 작업에서 드러났음에 주목한다. 20세기 중반 기존 추상표현주의를 모방하던 로스앤젤레스 화단은 셰이프트 캔버스 및 하드 엣지 형태의 비(非)-전통적 회화 작업을 통해 서부 미니멀리즘을 발단시켰다. 이후 서부 미니멀리즘은 동시대 팝아트와 맞물려 피니쉬 페티쉬(Finish Fetish)로 이어졌다. 이때 피니쉬 페티쉬는 로스 앤젤레스 자동차 문화라는 지역성을 바탕으로 로스앤젤레스 팝아트로서의 정체성을 구축하였 다. 또한, 서부 미니멀리즘의 회화에 대한 지속적 관심은 1970년대 오브제 및 공간 작업으로 전 환한 일부 작가들의 회화로의 복귀로도 나타난다. 회화의 복귀는 3차원 형태의 작업으로 총체적 으로 전환한 뉴욕 미니멀리즘과 비교되는 서부 미니멀리즘의 특징이다.

The seismic responses of traffic light poles are investigated using a finite element analysis. Among the traffic light poles, single- and bi-directional traffic light poles are considered since such poles are frequently installed on vehicle roads. For a more detailed investigation, three different lengths of the mast arm are considered for each directional pole. For a time-history analysis, six actual and two artificial earthquakes are considered and applied to each direction of the poles (x and y) to investigate which direction input provides more significant responses due to the unsymmetrical structural shape. Herein, the x and y directions are respectively parallel and perpendicular based on the single mast pole case. From the analysis results, the average maximum displacement response is developed with the x-direction input case for both types of light poles. Also, the bi-directional traffic light poles show a 13% larger response than the single-directional traffic light poles. Even though the y-direction input case produces a smaller response, the response difference between the single- and bi-directional light poles considerably increases by about 60%. The average maximum acceleration responses are almost similar for both types of light poles.

안트라센의 골격을 갖는 청색 발광 물질, 9-(2-naphthyl)-10-(p-tolyl)anthracene (2-NTA)를 기본으로 하고, 오렌지 도판트인 루브렌을 다양한 부피비로 사용하여 백색 유기발광소자를 제작하였다. 그 결과 C.I.E. 좌표가 (0.32, 0.39)인 백색 유기발광소자를 얻었다. 다양한 부피비의 소자 중 루브렌을 1.5% 이하로 증착된 소자가 3% 이상으로 증착된 소자 보다 전기발광 효율이 높았다. 더욱이 2-NTA를 포함하 는 백색 유기발광소자는 같은 조전하에서 2-NTA 만의 청색 유기발광소자 보다 낮은 턴온 전압을 갖는다. 결론적으로 2-NTA는 적은 양의 오렌지 도판트만으로 순수한 백색 유기발광소자를 구현할 수 있다.