Hydrogen peroxide (H2O2) is widely used in bleaching treatments in the pulp and paper industry, in wastewater treatment, and as a food additive. However, H2O2 solutions are unstable and decompose slowly when subjected to external factors such as light, high temperatures, or metal compounds. Therefore, a simple and reliable method to measure the concentration of H2O2 is required for its proper use in various applications. We determined the concentration of an H2O2 solution by measurement at a single wavelength (249 nm) without any reagents or complex analytical procedures. In the present work, the measurable concentration of H2O2 was as low as 0.015 wt% (4.41 mM) and as high as 0.300 wt% (88.2 mM), with high linearity (99.99% at 249 nm) between the concentration of H2O2 and the optical density (OD) values. In addition, the method could be used to measure the concentration of H2O2 in a peracetic acid solution without interference from acetic acid and peracetate ion.
국립원예특작과학원에서는 밝은 화색과 안정적인 화형의 생 육이 우수한 빨간색 스탠다드 장미 품종을 육성하기 위해 진한 적색 스탠다드 장미 품종 ‘엔드리스러브(Endless Love)’를 모 본으로, 꽃잎수가 많고 안정적으로 가시가 적은 밝은 노란색 ‘페니레인(Penny Lane)’ 품종을 부본으로 인공교배하였다. 37 개의 교배실생을 양성해 1, 2, 3차에 걸친 특성검정 및 현장실증 을 통해 꽃이 크고 화형이 안정적이며, 재배안정성 및 생산성, 절화특성이 우수한 ‘원교 D1-390’을 최종 선발하였다. 2023년 ‘루비레드(Ruby Red)’로 명명하여 국립종자원에 품종보호출원·등록되었다. ‘루비레드’ 품종은 밝은 적색(R53C)을 가졌으 며, 꽃잎수가 32.8매, 화폭과 화고는 각각 10.9, 5.9cm로 대조 품종보다 크다. 절화장은 평균 71.7cm, 절화수명은 약 16.7일, 수량은 연간 168대/m2로 대조품종인 ‘레드스퀘어(Red Square)’ 대비 절화장이 길고 절화수명도 2배 이상 길며, 수확량도 1.4배 우수하다. 2023년 국내 육성 장미 품종 서울식물원 관람객 대상 공동평가회에서 스탠다드 장미 중 우수한 평가를 받았으며, 현 장 실증 결과 농가별로 균일하고 우수한 수량과 절화품질을 보 였다. 절화용 장미 ‘루비레드’ 품종은 밝은 적색과 우수한 화형 을 가지는 품종으로 해외 대체 품종으로 국내에서 많이 재배될 것으로 기대된다.
Schlumbergera truncata absorbs CO2 through its mature phylloclades during the night, and can use a substantial amount of CO2 without requiring ventilation. This study investigated the growth and photosynthetic responses of S. truncata ‘Red Candle’ at two CO2 levels—ambient (≈ 400 μmol・mol-1) and elevated (≈ 1000 μmol・mol-1). At 0–8 weeks after treatment (WAT), width and length of mature phylloclade and length of immature phylloclade did not differ significantly among the CO2 treatments. At 4–8 WAT, number of branches and phylloclades were significantly greater in plants grown under ambient CO2 than those under elevated CO2. Net CO2 uptake was highest in mature phylloclades of plants grown under ambient and elevated CO2 regimes at night, at 2.51 and 1.30 μmol·CO2·m-2·s-1, respectively. However, no statistically significant variation was observed at 6 WAT, and stomatal conductance was significantly affected only by CO2 uptake time at 6 and 8 WAT. Water-use efficiency of mature and immature phylloclades at night increased with increase in CO2 levels (r = 0.7462 and 0.9312, respectively). At 123 days after treatment, plants grown under elevated CO2 had 82.7 floral buds, compared to 72.1 buds in those under ambient CO2. However, this difference was not statistically significant. Moreover, S. truncata grown under elevated CO2 exhibited decreased growth and photosynthesis, whereas the number of floral buds did not exhibit any significant differences among the treatments.
Entomopathogenic fungi serve as eco-friendly alternatives to chemical pesticides. In this study, we investigate the interactions between mosquitoes and Metarhizium anisopliae JEF-157, which showed high insecticidal activity against mosquitoes, by RNA-seq analysis. RNA from mosquitoes was extracted at the median lethal time to identify changes in gene expression. The results showed 580 genes were up-regulated, while 336 genes were down-regulated in fungal treated mosquitoes. Up-regulated genes were related to metabolic and cellular processes such as cytochrome P450, DNA replication, and apoptosis. Down-regulated genes were involved in metabolism pathways such as lysosome, starch and sucrose metabolism, and fatty acid biosynthesis. These results are crucial for elucidating the mechanisms of fungal invasion and interaction in insects, providing insights for future pest management strategies.
Entomopathogenic fungi have been studied to control insect pests as an alternative to chemical insecticides. However, all fungi haven't a high virulence against pests. In this study, we compared the biological characteristics of Metarhizium anisopliae strains. First, we selected four M. anisopliae strains and compared the thermotolerance, conidial productivity, and virulence. For the thermotolerance test, conidial suspensions were exposed to 0, 30, 60, and 90 min at 45 °C. As a result, the conidial germination rates were over 95% when exposed for 0 min but, were 64, 37.7, 6, and 3% when exposed for 30 min at 45°C, respectively. To compare conidial productivity, 200g of millet were used and inoculated with a conidial suspension of 1 ml (1×107 conidia/ml). Conidial productivity was investigated after 14 days. As a result of conducting a virulence test against mealworms using a spray method, differences in virulence between strains were confirmed.
Climate change has led to increased insect pests and pest distribution changes. Traditionally, chemical control using synthetic pesticides has been the main method for pest management, but the emergence of pesticide-resistant pests has become a problem. There is a need to develop new pest control agents to overcome these issues. Entomopathogenic fungi used in pest management have minimal environmental side effects and possess a mechanism of action distinct from that of synthetic pesticides. However, there is a need for the development of technologies to maximize the insecticidal effects of fungi against pests, and expressing and releasing dsRNA within the fungi can preemptively knock out the activation of the insect’s defense system, thereby enhancing the insecticidal effect. Controlling insect defense genes and using entomopathogenic fungi as bio-carriers forms a new pest management strategy. This approach, described as a “microbial insecticide agents development strategy of cassette concept, ” can versatilely modify genes and microbes. It is expected to overcome the limitations of synthetic pesticides.
본 연구는 민간시장의 절화 유통 현황을 조사하여 국내 절 화 시장 유통 및 판매의 기초 자료로 제공하고자 수행하였다. 조사 기간은 2022년 5월부터 10월까지이며, 민간시장 내 판 매 점포 수, 취급 품목, 수입국 및 품목 등을 비교 및 분석하 였다. 민간시장은 서울 서초구 반포동에 위치한 강남터미널 꽃시장을 대상으로 판매 품목 및 수입 국가 등을 조사하였고, 비교 대상인 공영시장의 경우 한국농수산식품유통공사 화훼 유통정보에서 제공되는 양재동 화훼공판장 거래 품목을 조사 하였다. 조사 결과, 민간시장의 월별 절화 판매 점포 수는 평 균 143개였다. 민간시장에서는 5월을 제외하고 장미 판매 매 장이 가장 많았다. 5월에는 카네이션 판매 매장이 가장 많았 으며 장미, 리시안셔스, 거베라가 그 뒤를 이었다. 민간시장 점포 내 수입 품목의 원산지는 호주, 중국, 콜롬비아, 이스라 엘, 이탈리아, 일본, 네덜란드, 페루, 남아프리카 공화국, 미 국, 베트남 등으로 조사되었다. 취급 품목은 민간시장이 69개 로 공영시장 18개에 비해 약 3.8배 많았으며, 이는 민간시장에서 수입 절화가 더 많이 유통되고 있음을 시사한다. 민간시 장은 공영시장과 달리 유통 정보를 알 수 있는 시스템이 없어 소비자들이 제품의 원산지, 품질, 가격 등을 파악하기 어렵다. 따라서, 민간시장의 절화 유통 정보를 소비자들에게 정확히 제공할 필요가 있으며, 이를 통한 투명한 거래 제공 및 소비자 의 신뢰도를 높이는 것이 중요하다.
The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.
The decommissioning of Korea Research Reactor Units 1 and 2 (KRR-1&2), the first research reactors in South Korea, began in 1997. Approximately 5,000 tons of waste will be generated when the contaminated buildings are demolished. Various types of radioactive waste are generated in large quantities during the operation and decommissioning of nuclear facilities, and in order to dispose of them in a disposal facility, it is necessary to physico-chemically characterize the radioactive waste. The need to transparently and clearly conduct and manage radioactive waste characterization methods and results in accordance with relevant laws, regulations, acceptance standards is emerging. For radioactive waste characterization information, all information must be provided to the disposal facility by measuring and testing the physical, chemical, and radiological characteristics and inputting related documents. At this time, field workers have the inconvenience of performing computerized work after manually inputting radioactive waste characterization information, and there is always a possibility that human errors may occur during manual input. Furthermore, when disposing of radioactive waste, the production of the documents necessary for disposal is also done manually, resulting in the aforementioned human error and very low production efficiency of numerous documents. In addition, as quality control is applied to the entire process from generation to treatment and disposal of radioactive waste, it is necessary to physically protect data and investigate data quality in order to manage the history information of radioactive waste produced in computerized work. In this study, we develop a system that can directly compute the radioactive waste characterization information at the field site where the test and measurement are performed, protect the stored radioactive waste characterization data, and provide a system that can secure reliability.
The inclusion of conductive carbon materials into lithium-ion batteries (LIBs) is essential for constructing an electrical network of electrodes. Considering the demand for cells in electric vehicles (e.g., higher energy density and lower cell cost), the replacement of the currently used carbon black with carbon nanotubes (CNTs) seems inevitable. This review discusses how CNTs can contribute to the development of advanced LIBs for EVs. First, the reason for choosing CNTs as a conducting agent for the cathode is discussed in terms of energy density. Second, the reinforcing effect of CNTs on the anode is described with respect to the choice of silicon as the active material. Third, the development of water-based cathode fabrication as well as dry electrode fabrication with aid of CNTs is discussed. Fourth, three technical hurdles, that is, the price, dispersion issue, and entrapped metal impurities, for widespread use of CNTs in LIBs are discussed.
The objective of this experiment was to investigate the effect of drip irrigation volume on tomatoes (Solanum lycopersicum L.) grown in a greenhouse using perlite medium. Plants were treated by three different irrigation treatment I0, I25, and I50 (where irrigation volume of I25 and I50 was 25% and 50% higher than I0, having limited or no leaching). Growth characteristics of plants, yield and water use efficiency were measured. The result showed that plant height, leaf length and leaf width were lowest in the I0 treated plants. However, these parameters were not statistically significant differences between the plants that were grown in the I25 and I50 treatment. Soluble solids content, acidity and dry matter of 111th, 132nd, and 143rd days harvested tomato were higher in the plants irrigated with lowest volume (I0) than the higher volume (I25 or I50). In addition, water content was lower in the 111th and 132nd days of harvested tomatoes from the I0 treatment. The number of big-size tomatoes (>180 g) was significantly higher in the I25 irrigated plants. There was no significant difference in the total number of harvested fruits among the treatments. The average fruit weight and total yield of harvested tomatoes were lowest in the I0 treated plants. The water consumption of tomato was not significantly different amongst the treatments but water use efficiency was lowest in the I0 treatment. Principal component analysis revealed that total soluble solid and acidity of tomato showed a positive correlation between each other. These results suggest that I25 was the optimum irrigation treatment for tomato based on its measured growth characteristics, yield and water use efficiency.
The number of dismantled nuclear facilities is increasing globally. Dismantling of nuclear facilities generates large amount of waste such as concrete, soil, and metal. Concrete waste accounts for 70% of the total amount of waste. Since hundreds of thousansds of tons of concrete waste generated, securing technology of reduction and recycling of waste is emerging as a very important issue. The objective of this study is to synthesize geopolymer using inorganic materials from cement fine powder in concrete waste. Dismantled concrete waste contains a large amount of calcium silicate hydrate(C-S-H), Ca(OH)2, SiO2, etc., which is an inorganic material required for the synthesis of geopolymer. SiO2 affects the compressive strength of the geopolymer and Ca(OH)2 affects the curing rate. A high concentration of alkali solution is used as an alkali activator, and alkali activator is necessary for the polymerzation reaction of metakaolinite. The experiment consists of three steps. The first step is to react with concrete waste and hydrochloric acid to extract ions. In the solid after filtration, SiO2 and Al2O3 are composed of 84.10%. It can be used instead of commercial SiO2 required for the synthesis of geopolymer. The second step is to add NaOH up to pH 10, impurities can be removed to extract Ca(OH)2 with high purity. The final step is to add NaOH up to pH 13, and Ca(OH)2 extraction. The alkali solution generated after the last reaction can be recycled into an alkali activator during the synthesis of the geopolymer. If dismantled concrete waste is recycled during geopolymer synthesized, the volume reduction rate of dismantled concrete waste is more than 50%. If you put the radioactive waste in the recycled solidification materials synthesis from concrete waste by dismantling of nuclear facilities, it is possible to reduce the amount of waste generated and disposal costs.
기후 변화의 가속화로 국내 제주 및 남부 지방을 중심으로 열대 및 아열대 작물의 재배 및 소비가 증가하는 추세이다.오크라는 식용적 가치가 있을 뿐만 아니라, 품종별 고유의 꼬 투리와 잎의 색은 관상적 가치가 있어 조경 식물로 많이 사용 되고 있다. 본 연구는 도심 내 옥상 온실에 관상식물인 오크 라를 도입하기 위해 피트모스와 펄라이트 비율에 따른 기초 종자 발아 및 육묘기 실험을 진행하였다. 피트모스와 펄라이 트 비율은 PT:PL=1:2, 1:1, 2:1, 4:1 네 가지로 조성하였다. 발 아율은 파종 후 7일차부터 다른 처리구에 비해 피트모스:펄라 이트=1:2의 처리구에서 가장 높았다. 파종 후 28일차와 70일 차에 줄기길이, 경경, 뿌리길이, 지상부와 지하부의 생체중과 건물중 그리고 엽면적은 피트모스:펄라이트=1:2 처리구에서 가장 높았다. 그러나, 파종 후 56일 이후부터 엽수는 피트모 스:펄라이트=1:2, 2:1, 4:1 처리구에서 감소하였다. 피트모스: 펄라이트=1:1, 2:1, 4:1 처리구에서 식물이 필요로 하는 피트 모스의 비율이 지나치게 높아 높은 피트모스 비율로 인하여 수분함수량이 과도하게 높아 식물이 고사한 것으로 판단된다. 따라서 오크라를 관상식물로 활용하기 위해서는 피트모스와 펄라이트를 1:2로 혼합한 배지가 가장 적합하다.