Drought stress is a condition that occurs frequently in the field, it reduces of the agricultural yield of field crops. The aim of the study was to screen drought-adapted genotype of Italian rye grass. The experiments were conducted between the two Italian ryegrass (Lolium multiflorum L.) cultivars viz. Hwasan (H) and Kowinearly (KE). The plants were exposed to drought for 14 days. The results suggest that the morphological traits and biomass yield of KE significantly affected by drought stress-induced oxidative stress as the hydrogen peroxide (H2O2) level was induced, while these parameters were unchanged or less affected in H. Furthermore, the cultivar H showed better adaptation by maintaining several physiological parameter including photosystem-II (Fv/Fm), water use efficiency (WUE) and relative water content (RWC%) level in response to drought stress. These results indicate that the cultivar H shows improved drought tolerance by generic variation, improving photosynthetic efficiency and reducing oxidative stress damages under drought stress. These findings can be useful to the breeder and farmer for improving drought tolerance in Italian rye grass through breeding programs.

본 연구는 장미 ‘Bubble Gum’에 대한 수확 후 LED 광 환경 과 살균제 Azoxystrobin 보존용액 처리 시 절화품질에 미치는 영향을 구명하고자 수행되었다. 광은 백색 LED와 유색 LED (red:blue=5:1)로 처리하였고, 보존용액은 수돗물(tap water, TW)과 Azoxystrobin 0.05 mL･L-1를 처리하였다. 백색 LED처 리의 절화수명은 TW, Azoxystrobin처리구 각각 9.6일, 9.7일 로 LED 광과 보존용액 처리 간의 유의차가 없었다. 유색 LED 처리의 절화수명은 TW처리구가 13.6일, Azoxystrobin처리구 가 9.8일로, 유색 LED 처리구가 대조구(백색 LED + TW)에 비해 절화수명을 4일 연장시켰다. 절화수명 종료 증상은 LED 광 조건과 관계없이 Azoxystrobin처리구는 꽃잎 위조와 청변 화 증상을 감소시켰다. 모든 처리구에서 상대생체중과 수분흡 수율은 각각 처리 후 2일, 4일까지 증가하다 감소하는 경향을 보였다. 수확 직후 대비 처리 6일 후 화색 변화율과 잎의 엽록 소 함량은 수확 직후와 모든 처리구에서 차이가 없었으며, 화 폭증가율도 처리 간 차이가 없었다. 결론적으로 백색 LED + Azoxystrobin 보존용액처리는 절화장미의 꽃잎 위조와 청변화 증상을 감소시키지만, 절화수명 연장효과가 없었으며, 적색 +청색 LED 처리는 장미의 절화수명 연장효과에 효과적이었다.

ROK Navy intends to secure the Korean-type aircraft carrier in order to effectively prepare for various future security threats. In general, the Korean national competency is considered to be at the level of having an aircraft carrier, but it is unclear what scale aircraft carrier would be appropriate. In this study, the efficiency was evaluated through the relative comparison between national competency(national power, economic power) and the scale of aircraft carriers, and the optimal scale of the Korean-type aircraft carrier that could be acquired was presented. A DEA(Data Envelopment Analysis) model was applied to aircraft carriers(19 aircraft carriers in 11 countries) currently in operation and scheduled to be possessed in the world. As input variables, CINC(Composite Index of National Capability) and GDP(Gross Domestic Product), which are the most widely used as indicators of national and economic power, and as output variables, the full-load displacement, length, and width of aircraft carriers were selected. ARIMA(short-term within 5 years) and simple regression(long-term over 5 years) were used to estimate the future national competency of each country at the time of aircraft carriers acquisition. The relative efficiency score of the Korean-type aircraft carrier currently being evaluated is 1.062, and it was evaluated as small-scale aircraft carrier compared to the national competency. Based on Korean national competency, the optimal scale of the Korean-type aircraft carrier calculated by aggregating benchmark groups, is 58,308.1 tons of full-load displacement, 279.4m in length, and 68.3m in width.

Most of the white fumes from the tenter process of a textile plant in an industrial complex are generated by water vapor and oil mist. While general water vapor disappears when the humidity is lowered, the white fume generated in the tenter process does not disappear and is continuously maintained, resulting in environmental problems and complaints. Efforts to reduce white fume are being conducted, but it is vitally important to develop a performance index that quantitatively calculates and deduces the degree by which white fume has been reduced, so that a tangible and visible result can be obtained in the performance evaluation of prevention facilities. In this study, the removal efficiency or performance of a general wet scrubber and a wet electrostatic precipitator (electrical fume collector, EFC) installed in the actual textile tenter process was analyzed by the light scattering method that can measure the concentration of particles up to a high level. The white fume removal efficiency of the EFC was 92%, much higher than the 17% removal efficiency of the general scrubber. In addition, the EFC was more effective in removing toluene, 1,1'- [oxybis(methylene)]bis- Benzene, and benzothiazole, which are the major substances generated from the textile tenter process, as well as complex odors. From these results, it was found that the light scattering method is one of the useful tools to evaluate the performance of white fume prevention facilities in the industrial field in terms of satisfying the urgent need for measurement and the ability to obtain a clear and precise result on site. This approach is meaningful in that real-time quantification is applicable more intuitively than the gravimetric method in assessing the fume removal performance as it can be observed with the naked eye.

This study investigated a graded-refractive-index (GRIN) coating pattern capable of improving the light extraction efficiency of GaN light-emitting diodes (LEDs). The planar LEDs had total internal reflection thanks to the large difference in refractive index between the LED semiconductor and the surrounding medium (air). The main goal of this paper was to reduce the trapped light inside the LED by controlling the refractive index using various compositions of (TiO2)x(SiO2)1−x in GRIN LEDs consisting of five dielectric layers. Several types of multilayer LEDs were simulated and it was determined the transmittance value of the LEDs with many layers was greater than the LEDs with less layers. Then, the specific ranges of incident angles of the individual layers which depend on the refractive index were evaluated. According to theoretical calculations, the light extraction efficiency (LEE) of the five-layer GRIN is 25.29 %, 28.54 % and 30.22 %, respectively. Consequently, the five-layer GRIN LEDs patterned enhancement outcome LEE over the reference planar LEDs. The results suggest the increased light extraction efficiency is related to the loss of Fresnel transmission and the release of the light mode trapped inside the LED chip by the graded-refractive-index.

장미의 단일 마디 삽목의 경우 온도, 상대 습도 및 광과 같은 환경 관리가 생산성에 영향을 미친다. 기온과 상대습도가 삽 목 성공률과 묘 소질에 미치는 영향을 조사하기 위해 장미 (Rosa hybrida) ‘Maisie’ 품종과 투명한 플라스틱 박스를 이 용하였으며 인공조명(white LED, PPFD 104.0μmol·m-2·s-1) 을 이용하여 전 기간 밀폐 조건에서 삽목 시 가장 효과적인 소 엽수와 광주기 조건을 구명하고자 하였다. 첫 번째 실험은 밀 폐 기간을 달리하여 총 6주 동안 진행되었다. 밀폐 기간이 길 어질수록 뿌리수와 가장 긴 뿌리의 길이가 감소하였다. 그러 나 밀폐 기간에 따른 생존율, 신초발생률, 발근율에 유의한 차 이가 없었다. 두 번째 실험에서는 삽수 생존율과 신초발생률 이 광주기(0/24, 2/22, 4/20, 8/16, 16/8h)와 삽수 소엽의 개수 (0, 2, 4)에 의해 영향을 받는 것으로 나타났다. 생존율은 명기 16시간, 소엽 4개 처리구에서 가장 높았다. 생존율과 신초발 생률을 에너지 효율과 함께 고려한 결과, 소엽을 2개 또는 4개 붙인 삽수를 이용하여 하루 8시간 광을 조사하는 것이 가장 효 과적인 것으로 판단되었다.

In this study, a two-stage electrostatic precipitator (ESP) was developed using a novel automatic dry cleaning device to reduce the ultrafine particles in subway stations. Collection efficiency was evaluated with a pilot scale ESP (1.2m× 1.2m) and the scale of the test duct was half of the subway air handling unit. The maximum collection efficiency for 0.3 μm particles was 96.9%. In addition, we studied a method of automatic dry cleaning for maintenance of the ESP. The cleaning efficiency was analyzed according to the cleaning flow rate for each particle loading amount to achieve a recovery rate over 90%. In addition, we derived the equation to estimate the reduction in collection efficiency according to the particle loading amount. It was confirmed that the performance of the contaminated ESP was restored to the initial state by the automatic dry cleaning in this study and that the electrical energy consumption was 5 times lower compared to utilizing conventional water cleaning.

Shipping companies are key components of the logistics industry, which is extremely significant in enhancing the country's comprehensive national power and promoting global trade development. In the context of the implementation of the new development pattern strategy in China and the impact of the global novel coronavirus (COVID-19), this paper takes 22 Chinese shipping listed companies as the research object and analyses the operational efficiency of them from 2011 to 2020 based on the Super-SBM DEA Model and Window DEA Model. Factors affecting the efficiency are further analyzed with the Tobit model. The research conclude that the operational efficiency of Chinese shipping companies as a whole shows a steady increase from 2011 to 2020. Although most of them are in a relatively effective operation state, fewer are absolutely effective companies. Besides efficiency among companies differs obviously, which indicates the potential of further improvement and promotion. What’s more, factors such as current economic development level, enterprise size, human resources quality and enterprise turnover speed have significant positive correlation to the operation efficiency of Chinese shipping listed companies, which is significant to improve the operation efficiency of Chinese shipping companies.

It is essential to provide a safe working environment for radiation workers. At a research reactor decommissioning site in Seoul (KRR1 & KRR2), radioactive waste drum disposal work is in progress. Before performing radiation work, it is necessary to determine the radioactivity of the waste drum to ensure safety. In this reason, we conducted a study to determine the detection efficiency of waste drums using the EXVol code. Determination of the full energy absorption peak efficiency (detection efficiency) is one of the important processes of the gamma-ray activation analysis. For the large voluminous gamma-ray sources like waste drum, the geometrical and attenuation effect should be considered. EXVol (Efficiency calculator for eXtended Voluminous source) code is a detection efficiency calculation code using the effective solid angle method. EXVol can calculate both coaxial and asymmetric structure. In addition, the introduction of a collimator made it possible to reduce the radiation intensity of a high radiation source. And it is possible to determine the precise detection efficiency according to the energy of a gamma ray at a specific position of the volume source. To verify the performance of the EXVol, a high resolution gamma spectroscopy system was constructed and measurement and analysis were performed. Measurements were performed on coaxial, asymmetric and collimated structures with standard point source, standard 1 L liquid volume source and HPGe detector. The measured results were compared with the calculation results of EXVol. The relative deviation of the measurement and calculation in the coaxial and asymmetric structures was 10%, and that of the collimation structure was 20%. Results can be available in analysis of waste drums’ radioactivity determination at a specific position.

The off-site dose calculation is regularly carried out at the nuclear power plants in order to evaluate off-site dose from gaseous and liquid effluent during normal operation. In 2009, the off-site calculation program (K-DOSE60) was developed in accordance with ICRP-60 by KHNP. This software needs meteorological data, gaseous and liquid effluent data, and various other input parameters to evaluate off-site dose. As a result, it takes a certain amount of time for the user to enter accurate input data and verify calculated results, and it is difficult to intuitively determine them because of providing textbased calculated results. Therefore, in this study, the improvement of the calculation program was considered so that a more reliable and effective evaluation could be performed when calculating the off-site dose. The main improvements of the off-site dose calculation program (ODCP) are as follows. First, it is developed as the network-based program to link with meteorological data, and gaseous and liquid effluent data to remove input errors and simplify data transfer. Second, through validation process of input data, input errors are eliminated. Third, the input data and calculated results are visually provided so that the user can easily determine the evaluation results. Fourth, database of input and calculated results is constructed to facilitate evaluation result history management.

Due to the environmental regulations of the International Maritime Organization (IMO), the number of ships using cryogenic fuel such as LNG (liquefied natural gas) is increasing rapidly, and the demand for eco-friendly ships is expected to grow further in the future. The material of the tank for storing cryogenic fuel such as LNG is limited within the IGC Code, and available materials include 9% nickel steel, Invar (36% nickel steel), Al5083-0, STS304L, and high manganese steel. Recently, 9% nickel steel has been used as a tank in LNG fuel-powered ship projects, and it has excellent thermal/mechanical properties in cryogenic LNG environmental conditions (-163°C). In this study, it is conducted an experimental study on SAW(Submerged Arc welding), which has better welding efficiency than FCAW(Flux Cored Arc Welding), which is mainly used for 9% nickel steel materials. In addition, to verify the reliability of the welded part after the welding test, cross-sectional observation of the welded part was performed and the mechanical properties such as the tensile strength and cryogenic impact strength of the welded part were evaluated.

A porous photocatalyst concrete filter was successfully produced to remove NOx, by mixing TiO2 photocatalyst with lightweight aerated concrete. Ultra Fine Bubbles were used to form continuous pores inside the porous photocatalytic concrete filter, which was mixed via a bubble generation experiment. The optimal mixing condition was determined to be with 4% of the bubble generation agent B. NO removal specimens were prepared for various photocatalytic loading conditions, and the specimen containing 3% P-25 removed NO at a concentration of 1.03 μmol in 1 h. The NO removal rate of the porous photocatalytic concrete filter prepared in this study was 10.99%. This photocatalytic filter performance was more than 9 times the amount of NO removed by a general photocatalytic filter. The porous photocatalyst concrete filter for removing NOx developed in this study can be applied to various construction sites and the air quality can be solved by reducing NOx contributing to the formation of fine particles.