A disposal of radioactive wastes is one of the urgent issues in worldwide. Considering upcoming plans for decommissioning of nuclear power plants, this problem is unavoidable and should be discussed very thoughtfully before long. There are variety of methods to deal with radioactive wastes, including Incineration process, conventional gasification process and plasma gasification process and so on. Among them, plasma gasification process is in the limelight due to its ecofriendly features and very large volume reduction effects. So, lots of countries like Japan, Taiwan, Russia, Bulgaria are already utilizing commercial plasma melting facilities and researching their own characteristics & disposal abilities and so on. Within the scope of this paper, I would like to introduce other countries current status of plasma melting facilities, and reach the conclusion on the directions to go for realistic radioactive wastes treatment.

Considering the domestic situation where all nuclear power plants are located on seaside, the interim storage site is also likely to be located on coastal site. Maritime transportation is inevitable and the its risk assessment is very important for safety. Currently, there is no independently developed maritime transportation risk assessment code in Korea, and no research has been conducted to evaluate the release of radioactive waste due to the immersion of transport cask. Previous studies show that the release rate of radionuclides contained in a submerged transport cask is significantly affected by the area of flow path generated at the breached containment boundary. Due to the robustness of a cask, the breach is the most likely generated between the lid and body of cask. CRIEPI investigated the effect of cask containment on the release rate of radioactive contents into the ocean and proposed a procedure to calculate the release rate considering the socalled barrier effect. However, the contribution of O-ring on the release rate was not considered in the work. In this study, test and analysis is performed to determine the equivalent flow path gap considering the influence of O-rings. These results will be implemented in the computational model to assess sea water flow through a breached containment boundary using CFD techniques to assess radionuclide release rates. To evaluate the release rate as a function of lid displacement, a small containment vessel is engineered and a metal O-ring of the Helicoflex HN type is installed, which is the most commonly used one in transport and storage casks. The lid of containment vessel is displaced in vertical and horizontal direction and the release rate of the vessel was quantified using the helium leak test and the pressure drop test. Through this work, the relationship between the vertical opening displacement and horizontal sliding displacement of the cask lid and the actual flow path area created is established. This will be implemented in the CFD model for flow rate calculation from a submerged transport cask in the deep sea. In addition, the compression of the O-ring causes very small gaps, such as capillaries. In these cases, Poiseuille’s law is used to calculate the capillary flow rate.

The solid-state chemistry of uranium is essential to the nuclear fuel cycle. Uranyl nitrate is a key compound that is produced at various stages of the nuclear fuel cycle, both in front-end and backend cycles. It is typically formed by dissolving spent nuclear fuel in nitric acid or through a wet conversion process for the preparation of UF6. Additionally, uranium oxides are a primary consideration in the nuclear fuel cycle because they are the most commonly used nuclear fuel in commercial nuclear reactors. Therefore, it is crucial to understand the oxidation and thermal behavior of uranium oxides and uranyl nitrates. Under the ‘2023 Nuclear Global Researcher Training Program for the Back-end Nuclear Fuel Cycle,’ supported by KONICOF, several experiments were conducted at IMRAM (Institute of Multidisciplinary Research for Advanced Materials) at Tohoku University. First, the recovery ratio of uranium was analyzed during the synthesis of uranyl nitrate by dissolving the actual radioisotope, U3O8, in a nitric acid solution. Second, thermogravimetric-differential thermal analysis (TG-DTA) of uranyl nitrate (UO2(NO3)2) and hyper-stoichiometric uranium dioxide (UO2+X) was performed. The enthalpy change was discussed to confirm the mechanism of thermal decomposition of uranyl nitrate under heating conditions and to determine the chemical hydrate form of uranyl nitrate. In the case of UO2+X, the value of ‘x’ was determined through the calculation of weight change data, and the initial form was verified using the phase diagram for the U-O system. Finally, the formation of a few UO2+X compounds was observed with heat treatment of uranyl nitrate and uranium dioxide at different temperature intervals (450°C-600°C). As a result of these studies, a deeper understanding of the thermal and chemical behavior of uranium compounds was achieved. This knowledge is vital for improving the efficiency and safety of nuclear fuel cycle processes and contributes to advancements in nuclear science and technology.

The development of food packaging materials with mechanical and antimicrobial properties is still a major challenge. N, P-doped carbons (NPCs) were synthesized. Poly(butylene adipate-co-terephthalate) (PBAT), which has an adverse effect on the environment and affects petroleum resources, has been commonly used for applications as food packaging. The development of PBAT composites reinforced with NPCs and studies on their structure and antimicrobial properties are presented in this study. The composite materials in the PBAT/NPCs were processed by solution casting. The plasticizing properties of NPCs enhanced the mechanical strength of composites produced of PBAT and NPCs. The thermal properties of PBAT composites were enhanced with addition of NPCs, according to thermogravimetric analysis (TGA). After reinforcement, PBAT/NPCs composites became more hydrophobic, according to contact angle measurements. In studies against S. aureus and E. coli food-borne pathogenic bacteria, the obtained composites show noticeably improved antimicrobial activity. The composite materials, according to the results of PBAT and NPCs may be a good choice for packing for food that prevents microorganisms.

In this study, we successfully grafted chitosan (CS) onto multi-walled carbon nanotubes (MWCNTs) to enhance their properties and potential applications in the biomedical field. FTIR spectroscopy confirmed the successful covalent bonding of CS onto MWCNTs, indicated by the new absorption peak of the amide bond (–CONH–). Thermal analysis showed that the modified MWCNTs (MWCNT-CS) had significant weight loss around 260 °C, suggesting the decomposition of hydroxypropyl chitosan, and confirming its presence in the nanocomposite. SEM images revealed that CS grafting improved the dispersibility of MWCNTs, a property crucial for their use as nanofillers in polymers. Moreover, the micro-tensile bond strength of dentin surface increased with increasing MWCNT-CS concentrations, indicating the potential of MWCNT-CS as a pretreatment for dentin bonding. After simulated aging, the bond strength remained significantly higher for MWCNT-CS groups compared to those without pretreatment. In biocompatibility assessment using the MTT assay, MWCNT-CS showed higher cell viability than MWCNT, suggesting improved biocompatibility after CS modification. The results of this study suggest that CS-modified MWCNTs could be promising materials for applications in dentin bonding, dentin mineralization, bone scaffolding, implants, and drug delivery systems.

A novel kind of self-assembled graphene quantum dots-Co3O4 (GQDs-Co3O4) nanocomposite was successfully manufactured through a hydrothermal approach and used as an extremely effectual oxygen evolution reaction (OER) electrocatalyst. The characterization of morphology with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that Co3O4 nanosheets combined with graphene quantum dots (GQDs) had a new type of hexagonal lamellar selfassembly structure. The GQDs-Co3O4 electrocatalyst showed enhanced electrochemical catalytic properties in an alkaline solution. The start potential of the OER was 0.543 V (vs SCE) in 1 M KOH solution, and 0.577 V (vs SCE) in 0.1 M KOH solution correspondingly. The current density of 10 mA cm− 2 had been attained at the overpotential of 321 mV in 1 M KOH solution and 450 mV in 0.1 M KOH solution. Furthermore, the current density can reach 171 mA cm− 2 in 1 M KOH solution and 21.4 mA cm− 2 in 0.1 M KOH solution at 0.8 V. Moreover, the GQDs-Co3O4 nanocomposite also maintained an ideal constancy in an alkaline solution with only a small deterioration of the activity (7%) compared with the original value after repeating potential cycling for 1000 cycles.

새만금 호의 수질 개선을 위하여 국가에서 해수 유통을 증가시킴에 따라 해수 유통 빈도 증가로 인한 새만금 호 내 염분과 저 층수 교환 변화를 알아보기 위하여, EFDC(Environmental Fluid Dynamics Code) 모델을 이용하였다. 갑문 개폐 횟수를 하루 1회에서 2회로 증 가했을 때, 새만금 호 내부 수위는 최대 약 0.7 m 상승하였다. 염분은 서측 방조제 근방에서 2.12 psu 증가하였으며, 담수 유입 부근에서는 1.18 psu 감소하였다. 입자추적을 이용하여 저층수 교환 정도 분석한 결과, 수심 5m 이하 입자 잔류율은 Case 2(1일 2회 개방)에서 Case 1(1 일 1회 개방)에 비해 2.52% 감소한 것으로 나타났다. 이는 수문 개폐 횟수를 증가시켰을 때, 저층수 교환이 더 활발해 질 수 있다는 것을 알 수 있다. 따라서 해수 유통 증가에 따른 염분 및 저층수 교환 증가로 새만금 호의 수질 개선이 될 수 있다고 판단된다.

아메리카동애등에 유충은 유기성폐기물을 먹이원으로 하며 그 분해산물인 동애등에분은 비료원료로 활용 가능하다. 그러나 농가에서 나오는 분변토는 염분함량이 높아 단독으로 사용하면 토양에 염류집적의 우려가 있다. 이에 산업곤충인 동애등에 분변토의 염분을 낮춰 퇴비로 활용하고자 옥수수(미백2호)에 5처리(무처리, 동애등에분, 동애등에분:흰점박이꽃무지분(2:8), 동애등에분:퇴비(2:8), 퇴비)로 비료를시용하였다. 옥수수 생 육은 초장, 간장, 웅수장, 착수고를 조사하였고 종실은 이삭중, 이삭장, 착립이삭장, 이삭폭 등을 조사하였다. 처리구별 옥수수 수량(kg/10a)은 무처리구 702.8kg, 동애등에분처리구 835.6kg. 동애등에분:흰점박이꽃무지분 (2:8) 처리구 723.7kg, 동애등에분:퇴비(2:8) 처리구 862.3kg, 퇴비 처리구 803.7kg으로 조사되었다. 동애등에 분변 토를 시판퇴비와 혼합하여 퇴비로 활용하면 옥수수 생산을 증진시키는데 효과적이나 장기적인 실험을 통해 토양과 작물에 미치는 영향을 모니터링해야 될 것으로 판단된다.

아메리카동애등에 성충은 음식물 폐자원 등 유기물이 있는 곳에 알을 낳는 습성이 있다. 대부분의 농가는 음식 물폐자원을 가공한 단미사료(습식사료)를 유인배지로 활용하여 그 위에 플로랄폼(오아시스)를 놓고 알을 받는 다. 그러나 플로랄폼은 재사용이 불가하고 생분해되지 않는 환경폐기물로서 처리가 곤란하며 포름알데하이드, 카본 블랙 등의 발암물질을 함유한 것으로도 알려져 있다. 이에 본 연구는 먹이원 자체를 활용하여 폐기물이 발생하지 않는 친환경 산란받이를 개발하였으며 일회용으로 사용되는 플로랄폼을 대체하였다. 먹이원으로 활 용할 수 있는 습식사료와 건식사료를 주재료로 하여 제작하며, 습식사료(수분60~80%)와 건식사료(1~10%)를 1:0.5~1 비율로 혼합한 사료 혼합물과 보조첨가제와 물을 포함하여 제작한다. 친환경 산란받이는 기존 플로랄폼 대비 산란율이 34% 증가하였으며 구매비용 또한 75% 절감하였다.

Hongjam is a natural health food that has been shown to have various health-promoting effects, but studies on immunity enhancement have not been done so far. In this study, we investigated whether HongJam extracts could be enhancing innate immunity by protomoting proliferatin of macrophages and their phagocytic or pinocytic abilities to pathogens. (Grant No. PJ017024022023)

Immunity is largely divided into innate immunity and adaptive immunity. We conducted a study using HongJam extract to confirm its innate immunity-enhancing effect. Our data using Natural Killer (NK) cells, which play an important role in innate immunity, confirmed that HongJam extract promotes the proliferation of NK cells and also enhances the function of NK cells to attack and destroy cancer cells. (Grant No. PJ017024022023)

The enzyme digestion of foods is known to have certain advantages, such as enhancing health improvement functions of functional foods. In this study, we investigated whether the memory enhancement effects of HongJam could be enhanced by enzymatic digestions. We found that enzyme digested HJ had more enhanced functionality than undigested HJ. We also found the molecular basis of memory enhancement by performing various biochemical and molecular biological experiments. (Grant No. PJ016908032023)

솔알락명나방(Dioryctria abietella)의 유충은 잣나무 구과를 가해 하는데, 피해를 심하게 받은 구과 종자의 손실량은 20.3%이며, 잣나무에서 구과피해율이 평균 25.7%에 달하여(이성찬, 2014), 잣 생산에 막대한 영향을 미치고 있다. 잣나무에서 페로몬 트랩의 설치 높이에 따른 솔알락명나방의 유인 효과 조사를 위하여 고가작업차 를 이용하여 잣나무림 지상부, 수관하부, 수관중부, 수관상부에 페로몬 트랩을 설치하였다. 페로몬은 케이아이 피에서 구입 하여 사용하였으며 트랩은 델타트랩을 설치하였다. 4월 26일에 최초 설치를 시작하여 기상상황에 맞게 10~15일 간격으로 수거하여 유인된 개체수를 조사하였다. 5월 초순에 4개 개체가 채집되기 시작하였으며, 6월 하순에 136개체가 채집되어 최대 밀도가 채집되었으며, 이후 점차 밀도가 감소하다가 8월 부터 밀도가 다시 증가하였다가 8월 중순 이후부터 다소 감소하기 시작하였다. 6월 초순에는 채집개체가 전혀 없었는데 이는 5월 하순부터 잣나무 송화가루가 날리면서 끈끈이트랩을 오염시켜 끈끈이트랩의 접착력이 떨어진 것에 기인한 것 으로 판단되었다. 수고별 솔알락명나방 페로몬 트랩 유인효과는 채집된 개체의 99.0%가 수관 상부에서 채집되 었으며, 2개체만이 수관중부에서 채집되었다. 수관하부와 지상에 설치된 트랩에서는 전혀 채집이 되지 않아 페로몬 트랩의 설치 높이에 따라 유인 효과가 매우 다른 것으로 나타났다.

Recently, the occurrence of the fall webworm, one of the foreign invasive pests, is rapidly increasing due to the increase in average annual temperature due to global climate changes. In this study, we are presenting diverse eco-friendly technologies to control the fall webworm. (Grant No. PJ014845032023).

두점박이사슴벌레는 2012년 5월 31일부터 환경부 지정 멸종위기야생생물 2급으로 보호받고 있는 딱정벌레 목의 사슴벌레과 톱사슴벌레속의 곤충으로 우리나라에는 제주도 숲에서 자생하고 있다. 보통 검정색 사슴벌레 와는 달리 황갈색의 이국적인 색상을 지니고 있으며, 가슴 양쪽에 2개의 검은색 점이 있는 것이 특징이다. 본 연구는 아열대기후의 특정 서식지에서만 살아가는 두점박이사슴벌레의 산업곤충으로써 가치성과 희귀성을 고려하여 인공증식 사육기술을 개발하였으며, 이 과정 중 점차적으로 온도를 낮춰가며 영상 8℃에서 90일간의 월동처리 하였고, 이러한 월동처리의 유무과정이 두점박이사슴벌레 유충기의 생육에 어떠한 영향을 미치는지 조사하였다. 비월동시 수컷 249일, 암컷 239일이었고, 성별간 수컷이 암컷보다 약 10일정도 더 길었으며, 암수 평균 유충기간은 245일이었다. 그리고 월동시에는 수컷 309일, 암컷 280일로 수컷이 약 30일정도 길었으며, 암수 평균 유충기간은 290일이었다. 월동처리 유무에 따른 두점박이사슴벌레 유충기간의 차이는 비월동 개체가 월동 개체보다 수컷은 약 60일, 암컷은 약 40일정도 짧았으며, 암수 평균 유충기간은 약 45일정도 짧았던 경향을 보였 다. 또한 유충의 생육특성 중 두폭은 처리간 서로 유사하였던 반면, 암수 무게는 월동 개체가 비월동 개체보다 모두 높게 나타났다. 우화의 경우 암컷이 비월동과 월동 개체에서 모두 수컷보다 빨랐던 경향을 보였다. 추후에는 월동 유무에 따른 성충 산란량과 사육 키트 개발을 위한 사육상자 크기 및 배지 높이별 성충 산란량, 온도 및 사육상 자 크기별 유충 생육 등의 연구를 추진할 계획이다.

아메리카동애등에(H. illucens)는 음식물 폐기물 등 유기성 폐자원을 효율적으로 처리할 수 있는 능력을 가지 고 있어 전세계적으로 주목받고 있는 환경정화 곤충이다. 하지만 유기성 폐자원을 처리 시 가장 큰 문제는 아메리 카동애등에가 먹이인 유기성 폐자원을 소화시킬 때 발생되는 악취이다. 국내에서 현재 아메리카동애등에를 사육하고 있는 농가는 223호로 조사되고 있지만 이중 악취발생 저감장치 등을 설치한 농가는 10%가 안되는 것으 로 생각된다. 따라서 국내에서 동애등에 먹이로 가장 많이 사용되는 습식사료를 먹이로 사용하였을 때 농가 사육 장 안에서 발생되는 복합악취와 지정악취 22종에 대하여 분석하였다. 그 결과, 복합악취는 249배였으며, 지정악 취는 22종 중 7종(암모니아, 메틸메르캅탄, 트라이메틸아민, 아세트알데하이드, 프로피온알데하이드, 뷰틸알 데하이드, i-발레르알데하이드)가 검출되었다. 이중 가장 높은 농도를 나타낸 악취물질은 암모니아로 98.4ppm 이 분석되었다. 또한, 아메리카동애등에를 사육 시 가장 많이 발생되는 암모니아의 발생시기는 사육초기인 1~4 령보다 5령 이후 전생육기 중의 대부분을 발생시키는 것으로 조사되었다. 이러한 결과는 암모니아 저감을 위한 적정시기를 설정하는데 도움이 될 것으로 생각된다.

Apolygus is one of speciose genus in subfamily Mirinae, including more than 80 species worldwide. Most of Apolygus species are phytophagous, and some species are regard as severe crop pest. For that, precise diagnosis and classification for this genus is crucial. In this work, we provide checklist of Korean Apolygus species with a new species and new distributional records. Diagnostic characters of the new species are discussed with the illustrations of adult male, female specimen and genitalic structures. A key to the Korean Apolygus is also presented.

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.

The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.