본 연구에서는 상용 폴리염화비닐을 개질하여 두 종류의 PVC 기반 이온교환용 고분자를 성공적으로 제조하였다. 이후 개질된 두 이온교환 고분자를 활용한 전기방사 공정과 열 압착 공정을 거쳐 2차원 계면(2D-PVC-BPM)과 3차원 접합부 (3D-PVC-BPM)를 갖는 바이폴라막(BPM)을 제조하였다. 제조된 3D-PVC-BPM은 2D-PVC-BPM에 비해 우수한 물 분해 효율 및 안정성을 보였다. 구체적으로, 300 mA cm-2의 고전류 밀도에서 3D-PVC-BPM은 2D-PVC-BPM가 나타낸 전위보다 4.4 V 낮은 8.05 V의 막 전위를 나타냈다. 더욱이, PVC 주쇄가 가진 내화학성 덕분에 3D-PVC-BPM은 가혹한 조건에서도 높은 화 학적 안정성을 보였고, 이는 4 M H2SO4 및 4 M NaOH 용액에 28일간 침지한 후 관측된 질량 손실이 각각 2.8%와 2.1%에 그친 것을 통해 입증되었다. 끝으로, 3차원 접합부가 3D-PVC-BPM에 맞물림(interlocking) 효과와 넓은 계면면적을 제공해준 덕분에 3D-PVC-BPM의 인장 강도는 36 MPa를 초과했고 신장률 또한 약 50%에 이르는 등 우수한 기계적 물성을 나타냈다.

In treatment processes of drinking water, the use of disinfectants is essential for eliminating microorganisms and pathogenic viruses. Chlorine dioxide (ClO2) is one of the most promising disinfectants. To ensure its effective application in drinking water treatment, it is crucial to investigate the stability and reactivity of ClO2 in drinking water treatment environments. Therefore, we examined the effects of various environmental factors such as temperature, light type, fluorescence intensity, and water quality on its stability. We also examined its reactivity with activated carbon and other inorganic compounds such as coagulants and hypochlorous acid. Findings revealed that ClO2 stability was influenced by several environmental factors. Typically, ClO2 is highly volatile. However, the rate of its volatility is independent of its concentration. As temperature and fluorescent light intensity increased, the concentration of ClO2 showed a rapid decline. Additionally, the presence of activated carbon significantly reduced ClO2 levels. In contrast, the reactivity of ClO2 with coagulants and hypochlorous acid was negligible. These findings provide essential insights for optimizing the use of ClO2 in drinking water treatment facilities.

The present study investigated the effects of forage cutting and baler mixing on the chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) haylage. The WCR (“Youngwoo”) was harvested at 48.4% dry matter and ensiled into a 300 kg bale silo with forage cutting (whole crop without cutting vs. 5 cm of cutting length). The WCR forages were ensiled without baler mixing process (CON) or with (MIX). The concentrations of dry matter, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 48.4, 9.70, 2.57, 6.11, 41.2, and 23.5%, respectively. The forage cutting did not affect the chemical compositions, fermentation indices, microbes, and aerobic stability of WCR haylage (p>0.05). The CON haylages tend to be higher in NDF content (p<0.10). The MIX haylages had lower in lactate (p=0.019), and lactate:acetate ratio (p<0.001). The MIX haylages had higher in lactic acid bacteria (LAB) (p=0.010). Therefore, this study concluded that the fermentation quality of WCR haylage improved by baler mixing, but had no effects by forage cutting.

The present study investigated effects of microbial additives and silo density on chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) silage. The WCR (“Youngwoo”) was harvested at 49.7% dry matter (DM), and ensiled into 500 kg bale silo with two different compaction pressures at 430 kgf (kilogram-force)/cm2 (LOW) and 760 kgf/cm2 (HIGH) densities. All WCR forage were applied distilled water (CON) or mixed inoculants (Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1) with 1:1 ratio at 1x105 colony forming unit/g (INO). The concentrations of DM, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 49.7, 9.59, 2.85, 6.74, 39.7, and 21.9%, respectively. Microbial additives and silo density did not affect the chemical compositions of WCR silage (p>0.05). The INO silages had lower lactate (p<0.001), but higher propionate (p<0.001). The LOW silages had higher lactate (p=0.004). The INO silages had higher yeast count (p<0.001) and aerobic stability (p<0.001). However, microbial counts and aerobic stability were not affected by silo density. Therefore, this study concluded that fermentation quality of WCR silage improved by microbial additives, but no effects by silo density.

본 연구는 기능성 물질인 알로에를 종류별로 첨가함에 따라 유화소시지의 이화학적 특성과 저장성, 그리고 관능성에 미치는 영향을 조사하기 위해 수행되었다. 알로에 베라(AV구)와 알로에 사포나리아(AS구)는 각 3%씩 첨가하였으며, 모든 처리구들은 냉장온도 4±1℃에서 4주간 저장하면서 주 1회 간격으로 실험이 진행되었다. pH는 AV구와 AS구가 대조구보다 유의적(p<0.05)으로 낮았고, 저장기간의 경과함에 따라 대조구 및 모든 처리구는 증가하였다. 보수성에서 AS구는 대조구와 AV구보다 유의적(p<0.05)으로 높은 값을 나타냈으며, 저장기간의 경과함에 따라 대조구 및 모든 처리구는 유의적(p<0.05)으로 감소하였다. 적색도는 AS구가 대조구 및 AV구 보다 낮은 값을 나타내었고, 황색도는 AS구가 대조구, AV구보다 높은 값을 나타내었다. 전단가는 AS구가 대조구보다 낮은 값을 나타냈으며, AV구와는 유의적인 차이가 없었다. 지방 산패도에서 AS구는 유의적 (p<0.05)으로 가장 낮은 값을 나타내었고, 관능 평가의 색은 AV구가 가장 높은 값을 나타냈으며, 선호도는 AV구가 대조구보다 높은 값을 나타냈고 AS구와는 유의적인 차이가 없었다. 이는 알로에 사포나리아의 첨가가 높은 보수성, 알로에 베라 첨가보다 낮은 지방산패도, 유사한 관능성을 나타내 기능성 소시지의 개발에 충분한 경쟁력을 가지고 있으며 향후 알로에 사포나리아를 첨가한 육제품의 일반화 및 대량생산 체계의 확립에 긍정적인 영향을 준다고 판단된다.

During the treatment of spent nuclear fuel, radioactive iodine is generated in a liquefied or gaseous form in a specific process. In the case of iodine 129, it is a long-lived nuclide with a very long halflife and has high groundwater mobility under repository conditions. Despite showing a low radioactivity value, research on the management of radioactive iodine from a long-term perspective is continuously being performed. Although research has been conducted using borosilicate glass as a medium for solidifying iodine, compatibility of I in borosilicate glass is very small and the volatility is high in the solidification process. So it is not suitable as a solidified substance of iodine. Therefore, studies on other solidification media to replace them are continuously being conducted. Our research team tried to develop a new medium that can contain iodine in a solidified body stably through a simple heat treatment process and can improve problems such as volatility and waste loading. Iodine is captured as AgI in the Ag ion-exchanged zeolite. So, TeO2, Ag2O, and Bi2O3 having a high AgI loading rate were used as main components. It was named TAB after taking the first letter of each element. In previous studies, the physical properties, structure, and chemical stability of TAB materials were confirmed. PCT (Product Consistent test) was performed to confirm chemical stability. It is mainly used to compare the chemical stability of glass materials with other glass materials, but there are limitations in evaluating the long-term chemical stability of materials. In this experiment, we tried to evaluate the long-term stability of TAB and compare it with borosilicate, which is conventionally used to treat radioactive waste. In addition, we tried to understand the leaching behavior inside the TAB medium. For this purpose, ASTM C1308 test was performed for 365 days, and distilled water and KURT groundwater were used as leachates to examine the effect of ions in the groundwater on the solidified body. To analyze the leaching behavior, ICP-MS and ICP-OES analyses were performed, and the cross-section of the sample after leaching was observed through SEM.

Saline water electrolysis is an electrochemical process to produce valued chemicals by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been used as polymer electrolyte membrane (PEM) materials owing to their high sodium ion selectivity and barrier properties. However, sulfonic acid groups in PFSA ionomers are chemically decomposed under a basic catholyte condition, which makes the PEM materials lose their ionic selectivity and Faraday efficiency. In this study, double layered membranes were prepared by anchoring cross-linked hydrocarbon ionomers, as a protection layer to catholyte atmosphere, into the water channels, particularly, located at around the surface of a PFSA membrane. Here, each monomer results in the identical chemical architecture and different free volume content when polymerized.