This research introduces an innovative approach for evaluating the degree of densification of carbon nanotube (CNT) sheets produced through direct spinning and subsequently treated with organic solvent (specifically ethanol). Analysis of the morphological features of the CNT sheets from the FE-SEM image affirms that the sheet’s structure becomes more densified following the treatment. Based on this, the treated CNT sheet was comprehensively evaluated using Raman spectroscopy. The results indicate a downward shift in the G′ band, signifying the densification of the CNT sheet’s structure due to the C–C bond weakening by the cohesive force. Following ethanol treatment, the CNT sheet exhibited enhanced electrical conductivity and tensile strength, measuring approximately 1.7 × 105 S m− 1 and 138.7 MPa, respectively, a remarkable improvement of roughly 300% compared to the untreated CNT sheet. This study underscores the efficacy of Raman spectroscopy as a powerful tool for assessing the densification of CNT sheets.
In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.
우리는 식물검역 과정에서 검출되는 파리목 유충을 효과적으로 동정하기 위하여 대화형 검색표를 제작하고 있다. 파리목은 농업 분야와 식물검역 분야에서 매우 중요한 해충이며, 특히 과실파리과는 다양한 식물에 피해를 주는 대표적인 분류군이다. 과실파리과는 예전부터 형태, 생태, 분자, 분류, 모니터링, 방제 등 다양한 주제로 연구가 이루어져 왔으며, 현재까지 다양한 연구가 이루어지고 있다. 본 연구에서는 과실파리과를 연구하는데 중요한 기초자료로 활용될 수 있도록 1)과실파리과 유충의 형태학적 특징을 포함하여 2)과실파리과의 일반적인 특징과 3)생태학적 특징 등 관련 정보를 수집하고 분석하여 결과를 종합정리하였다.
GN01 is a new antiviral medicine acting against Korean Sacbrood virus (KSBV) of honeybees. It contains 5 mg/mL of active ingredient, double stranded RNAs(dsRNA), that homologous to KSBV ribonucleic acid coding coat protein (VP1) of virus and inducing RNA interference (RNAi). RNA medicine is generally recognized as safe for rapid breakage by intrinsic ribonuclease and limited absorption from gastrointestinal tract. However, there were no data of repeat-dose toxicity in laboratory animals for dsRNA targeting SBV. This study was performed to investigate toxicity of GN01 in SD rats after weekly oral dosing for 28 days and to determine its no-observed-adverse-effect-level (NOAEL). Male and female SD rats were orally administered with GN01 at 0, 25, 50 and 100 mg/kg bw/day of dsRNA once per week for 28 days (total 5 administrations). The highest dose 100 mg/kg bw/day was determined based on the maximum volume injectable (20 mL/kg bw) via gavage. During treatment period, clinical signs, functional and sensory responses, body weights, food and water consumption, ophthalmological findings and urinalysis were investigated. After treatment period, hematological and clinical biochemistry tests and examination of necropsy findings, organ weights and histopathological lesions were performed. There were no significant differences between all test groups and vehicle control group in all measured parameters. Therefore, the NOAEL of GN01 was determined 100 mg/kg bw/day, the highest dose administered. In conclusion, repeated oral administration of GN01, a dsRNA medicinal product, is safe even at the maximum available dose in rats.
Mecysolobini족에 속하는 Sternuchopsis (Sternuchopsis) waltoni (Boheman, 1844) (메꽃통바구미; 신칭) 암컷 1개체를 한반도의 남단인 부 산의 가덕도 야산에서 떨어잡기를 통해 채집하였다. 이 바구미가 국내 식물방역법상 검역해충으로 지정되어 있어 침입종 또는 자생종 인지 여부를 판단할 필요가 있으나 현재 작물에 대한 피해가 확인되지 않고 있고, 그 밖의 채집정보도 없어 그 판단은 무리가 있다고 생각된다. 본 연구는 이 바구 미에 관한 국내 발생정보를 더 확보하기 위한 정확한 진단정보 및 생태정보를 제공하고자 한다.
표면발현(surface-display system)은 세포 또는 바이러스 표면에 목적 단백질을 고정하여 발현시킴으로써 목적 단백질에 대하여 독립적인 공간 구조 및 생물학적 활성을 부여하는 단백질 공학 기술이다. 또한 이를 이용하여 높은 중화항체 유도 및 대량생산이 가능한 삼량체의 형태로 항원 단백질의 발현 또한 가능하다. BES(baculovirus expression system)에서의 표면발현 기술은 번역 후 수정과정 및 복잡한 구조의 다양한 단백질의 발현이 가능하기 에 다른 숙주 기반 시스템보다 효율적이라고 보고되고 있다. 그러나 목적 단백질 외의 다른 표면 단백질과 발현 공간에서의 경쟁으로 목적 단백질의 낮은 생산량이 큰 문제점으로 지적되고 있다. 따라서, 이러한 BES에서 표면 발현의 생산 효율을 증대시키기 위하여, 동일한 표면 공간에 대한 단백질 간의 발현 경쟁에 대해 실험적으로 확인 후, 그를 해결하기 위하여 표면발현에 최적인 목적 단백질 발현을 위한 프로모터 선발 실험을 수행하였다. 이를 통해 BES에서 표면발현에 의한 목적 단백질의 생산 효율을 증대시킬 수 있음을 확인하였다.
최근 기후변화로 인해 외래 무척추동물(곤충)의 돌발발생 가능성이 높아지고 있는 추세를 감안할 때 이들에 대한 확산 및 변화예측 진단을 통한 조기방제의 중요성이 대두되고 있다. 그러나, 외래곤충의 종 정보 및 정확한 침입경로가 충분치 않아 문제해충이 될 가능성이 매우 높은 것이 사실이다. 또한, 신속정확한 정책결정을 위해서 는 현장조사자료가 체계적으로 수집되어 종합되어야만 정확한 진단 및 방제에 활용될 것이므로 이에 대한 다양 한 장치가 필요하다. 현재 국내 서식 중인 주요 산림해충 일부를 제외한 종들은 대부분 외래곤충으로 돌발적으로 대발생한 해충이 많이 포함되어 있어 국내에 유입된 외래 곤충에 대한 체계적인 데이터 확보를 통해 정착, 확산, 생태계 영향 예측모델 개발 및 활용시스템의 구축이 요구되는 실정이다. 따라서, 본 연구는 외래 곤충의 전국적인 모니터링을 통해 분포정보 및 생태정보 등의 중요 데이터 수집과 최신 정보를 활용하여 국내 유입된 외래 곤충의 정착, 확산, 생태계 영향 및 변화예측을 위한 전략수립과 모바일 등을 이용한 전자야장의 사용에 대해 논하고자 한다.
As various accidents have occurred in underground spaces, we aim to improve the quality validation standards and methods as specified in the Regulations on Producing Integrated Map of Underground Spaces devised by the Ministry of Land, Infrastructure and Transport of the Republic of Korea for a high-quality integrated map of underground spaces. Specifically, we propose measures to improve the quality assurance of pipeline-type underground facilities, the so-called life lines given their importance for citizens’ daily activities and their highest risk of accident among the 16 types of underground facilities. After implementing quality validation software based on the developed quality validation standards, the adequacy of the validation standards was demonstrated by testing using data from two-dimensional water supply facilities in some areas of Busan, Korea. This paper has great significance in that it has laid the foundation for reducing the time and manpower required for data quality inspection and improving data quality reliability by improving current quality validation standards and developing technologies that can automatically extract errors through software.
Nowadays, variable materials have been investigated to find alternative lightweight conductors instead of copper because copper has a relatively high density. Carbon nanotube (CNT) is one of the most suitable materials as an alternative conductor to Cu, thanks to its high conductivity. In addition, CNT has many other great properties, such as low density, high strength, and high ampacity. However, individual CNT loses some of its performance after the assembly process. Therefore, CNT materials have been electroplated with copper to achieve lighter conductors. In this study, CNT buckypaper (CNTBP) is fabricated using a multi-walled carbon nanotube and copper electroplated using optimizing electrolyte with the help of additive chemicals such as accelerator and suppressor. Furthermore, the effect of hydrochloric acid in the electrolyte on the electroplating of CNTBP is observed. The results show that HCl in electrolyte enhances the effectiveness of additive chemicals and provide a well-plated CNTBP@Cu composite. The composite in this study is expected to be used in various areas.
The aim of this study was to determine the contamination of mycotoxins and the concentration of preservatives and antioxidants in commercial pet food. 106 pet foods were purchased from online in Korea. Mycotoxin analysis were performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and preservatives and antioxidants were analyzed by high performance liquid chromatography (HPLC). The contamination of the mycotoxins in all samples was proved to comply with the Korea legislation with regards to animal feed, the analyses revealed presence of aflatoxins, ochratoxin A, zearalenone and fumonisins, with values below 1.6 ㎍/㎏, 12.1 ㎍/㎏, 478.5 ㎍/㎏ and 1873.5 ㎍/㎏, respectively. Furthermore, the simultaneous presences of different mycotoxins were observed in most of positive samples. The levels of dehydroacetic acid (DHA), sorbic acid (SA) and benzoic acid (BA) were, respectively, with values below 0.24 g/㎏, 4.82 g/㎏ and 6.35 g/㎏. The concentrations of butylated hydroxy anisole (BHA) and butylated hydroxy toluene (BHT) were demonstrated to be acceptable, with values below 0.04 g/㎏, and 0.02 g/㎏. This indicated the need for further investigation into the potential risk deriving from chronic exposure to low doses of mycotoxins. Additionally, a co-contamination of mycotoxins which interact in synergic manner are more concern. As DHA that not accepted was detected and very high levels of SA were identified in samples, an upper limit for preservatives in pet foods should be established in pet foods. BHA and BHT were detected within the recommended levels for antioxidant content, so these are considered as safe.
부추속은 수선화과에 속하며 약 1000여종에 이른다. 좀부 추는 자생 부추속에 속하며 식용이 가능하고 크기가 작아 분 화식물로 적합하다. 이에 따라 본 연구는 좀부추를 분화 소재 로서 개발하기 위하여 식물의 측지성장을 촉진하고 꽃의 품질 을 향상시키기 위해 수행되었다. 이를 위하여 좀부추의 구근 을 생장조절제(GA3, BA, 에테폰, TDZ)에 다른 시간(1, 5시 간)동안 침지처리했을 때 식물의 생장과 꽃에 어떤 영향을 주 는지 조사하였다. GA3 처리구는 엽수와 자구의 수가 증가해 증식을 촉진시키는 효과가 있었다. 게다가 GA3는 화수의 증 가와 조기개화를 유도했다. 그러나 엽폭과 화경의 폭은 감소 하였다. 에테폰은 좀부추의 초장과 초폭에서 영향을 주지 않 았으나 1h에서 자구의 수가 증가하였다. 에테폰은 화서 발생 을 억제하여 화경의 수가 감소하였다. BA는 식물의 생장과 개 화 특성에 유의적인 영향을 보이지 않았다. TDZ처리한 식물 은 왜화되고 생육상태가 불량하였으며, 식물을 고사시켰다.
Some consumer goods containing radioactive substances are in circulation and used in everyday life. In accordance with the Nuclear Safety Act, consumer goods with radioactivity are regulated. However, since most consumer goods distributed in Korea have no information that can confirm the amount of radiation, it is necessary to analyze the radiation for safety regulation. Among these consumer goods, GTLS (Gaseous Tritium Light Source) contains gaseous tritium (tritium, written as 3H or T), which is a radioactive material. The gaseous composition ratio in GTLS was analyzed using a precision gas mass spectrometer (Thermo Fisher, model MAT 271). As a result of GTLS analysis, the H2, HD or H3 +(T) or 3He, HT or D2 or He, DT, and T2, which correspond to the mass-to-charge ratio (m/z) 2 to 6 and the air components were detected. In addition, substances corresponding to m/z=24 and m/z=21 were also detected. These were compared with pure CH4 and those fragmentation patterns. The ratios of CT4 (m/z = 24) to CT3 (m/z = 21) and CH4 (m/z = 16) to CH3 (m/z = 15) were compared and they agree within the measurement uncertainty. We also performed additional experiments to separate the water component in the GTLS samples, considering the possibility that the m/z = 21 to m/z = 24 region is tritium compounds based on H2O. Despite the removal of the water components, peaks were detected at m/z=21 and m/z=24. Therefore, we confirmed that the component of m/z = 24 in the GTLS sample was CT4.
Air conditioning facilities in nuclear power plants use pre-filters, HEPA filters, activated carbon filters, and bag filters to remove radionuclides and other harmful substances in the atmosphere. Spent filters generate more than 100 drums per year per a nuclear power plant and are stored in temporary radioactive waste storage. Plasma torch melting technology is a method that can dramatically reduce volume by burning and melting combustible, non-flammable, and mixed wastes using plasma jet heat sources of 1,600°C or higher and arc Joule heat using electric energy, which is clean energy. KHNP CRI & KPS are developing and improving waste treatment technology using MW-class plasma torch melting facilities to stably treat and reduce the volume of radioactive waste. This study aims to develop an operation process to reduce the volume of bag filter waste generated from the air conditioning system of nuclear power plants using plasma torch melting technology, and to stably treat and dispose of it. It is expected to secure stability and reduce treatment costs of regularly generated filter waste treatment, and contribute to the export of radioactive waste treatment technology by upgrading plasma torch melting technology in the future.
Since high-level radioactive wastes contain long-lived nuclides and emit high energy, they should be disposed of permanently through a deep geological disposal system. In Korea, the first (2016.07) and the second (2021.12) basic plans for the management of high-level disposal systems were proposed to select sites for deep geological disposal facilities and to implement business strategies. Leading countries such as Finland, Sweden and France have developed and applied safety cases to verify the safety of deep geological disposal systems. By examining the regulatory status of foreign leading countries, we analyze the safety cases ranging from the site selection stage of the deep geological disposal system to the securing of the permanent disposal system to the investigation, analysis, evaluation, design, construction, operation, and closure. Based on this analysis, we will develop safety case elements for long-term safety of deep geological disposal systems suitable for domestic situation. To systemically analyze data based on safety cases, we have established a database of deep geological disposal system regulations in leading foreign countries. Artificial intelligence text mining and data visualization techniques are used to provide database in dashboard form rather than simple lists of data items, which is a limitation of existing methods. This allows regulatory developers to understand information more quickly and intuitively and provide a convenient interface so that anyone can easily access the analyzed data and create meaningful information. Furthermore, based on the accumulated bigdata, the artificial intelligence learns and analyzes the information in the database through deep learning, and aims to derive a more accurate safety case. Based on these technologies, this study analyzed the legal systems, regulatory standards, and cases of major international leading countries and international organizations such as the United States, Sweden, Finland, Canada, Switzerland, and the IAEA to establish a database management system. To establish a safety regulation base suitable for the domestic deep geological disposal environment, the database is provided as data to refer to and apply systematic information management on regulatory standards and regulatory cases of overseas leading countries, and it is expected that it will play a key role as a forum for understanding and discussing the level of safety of deep geological disposal system among stakeholders.
Timely detection of nuclear activity is important for the management and supervision of nuclear materials, and inspections on North Korea as a method of safety measures for this monitoring system seem to be a not far future in the rapidly changing North Korea relationship. However, a simpler and more reliable monitoring device is required since the inspection period is limited and the possibility of revisiting is unclear. The seal is a simple but easily used security device for monitoring forgery and falsification in the IAEA. IAEA presents matters related to 1) project engineering, 2) remote monitoring, and 3) seal development as the three major tasks of the Department of safeguards and Division of Technical Support. The importance of development, modernization, and application of new seal devices is emphasized, and advanced sealing and identification system development is in progress at many research institutes such as JRC, ISCN, and JAEA. Since the existing seal devices used by IAEA and KINAC can only be confirmed through on-site inspections for damage, it is difficult to respond immediately in the event of similar situations such as theft of nuclear materials and loss of continuity of knowledge. Unlike facilities that comply with the requirements for safety measures, such as domestic nuclear facilities, in the case of facilities subject to denuclearization, it is very likely that various hazardous environments will exist that make it difficult to apply safety measures. Hence, a real-time seal device has developed through prior research due to the high possibility of situations in which Continuity of Knowledge (COK) is not maintained, such as damage, malfunction, and power loss of sealing and monitoring equipment. Through previous studies, the real-time seal device was loaded with server-based operating software and improved its performance by utilizing feedback from real users (KINAC) after use. In this study, the effectiveness of the previously developed sealing system was verified through performance evaluation, and the authentication of the equipment was secured through environmental tests.