국내 고속도로의 콘크리트 포장은 줄눈 콘크리트 포장 공법을 주로 적용해 왔으나 잦은 줄눈부 파손으로 인해 최근에는 공용성이 우수한 연속철근 콘크리트 포장(CRCP)을 확대 적용하고 있는 추세이다. CRCP는 우수한 공용성을 가지고 있지만 다량의 철근 사용으 로 인해 초기 시공비가 높은 단점이 있다. 이러한 CRCP의 단점을 보완하고 공용성을 보다 향상시키기 위해 신개념 철근콘크리트 포 장(ARCP)이 개발되었다. 본 연구에서는 ARCP의 공용성 검증을 위해 고속도로 제14호선 함양~울산 구간에 시공된 ARCP와 동일한 구 간에 시공된 CRCP의 균열조사를 수행하였으며 균열형상 및 균열간격 등을 비교 분석하였다. 분석 결과 ARCP에서 발생한 균열은 CRCP와 비교하여 대부분 직선 형상으로 발생하였으며 균열간격도 보다 균일한 것을 확인하였다. 또한, ARCP에서는 좁은 균열간격, 지그재그 균열, 분리균열 등 부적절한 균열의 발생이 매우 적은 것을 확인하였다. 따라서 ARCP의 균열형상 분석 결과로 보아 ARCP 는 CRCP의 우수한 공용성을 보다 향상시킬 수 있는 공법이라는 것을 검증하였다.
신개념 철근콘크리트 포장인 ARCP(Advanced Reinforced Concrete Pavement)는 연속철근 콘크리트 포장인 CRCP(Continuously Reinforced Concrete Pavement)에서 균일하지 않게 발생하는 균열과 다량의 철근 사용으로 인한 높은 시공비를 개선한 기술이다. ARCP 는 고속도로 제1호선 언양~영천 구간에 최초로 시공하였으며 고속도로 제14호선 밀양~울산 구간에도 시공하였다. 이전의 시공 과정 및 초기 공용성을 기반으로 ARCP의 주요 기술 요소인 부분철근과 균열유도장치의 형상을 개선하여 고속도로 제14호선 창녕~밀양 구 간에 적용하여 시공하였다. 기존 균열유도장치는 반달형의 GFRP 재질로 제작되었으며 지지대를 이용하여 설치하였으나 개선된 균열 유도장치는 L형의 철재로 부분철근에 용접된 어셈블리 형태로 제작되어 설치가 간단하다. 기존 부분철근은 2개의 부분철근을 서로 연 결시킨 형상이었으나 개선된 부분철근은 연결부를 두지 않고 독립적인 형상으로 설치하였다. ARCP 시공 이후 초기 현장조사 결과, 균 열유도장치가 설치된 곳에서 적절한 균열이 발생하는 것을 확인하였으며 슬래브 표면 침하도 발생하지 않았다. 따라서 개선된 부분철 근과 균열유도장치를 적용함으로써 ARCP의 시공성 및 공용성을 한층 더 향상시킬 수 있을 것으로 기대된다.
최근 급격한 기후 변화로 인해 도로 교통사고의 발생 빈도가 증가하고 있으며, 특히 겨울철에 자주 발생하는 도로 살얼음(블랙아이 스) 현상이 주요 원인 중 하나로 지목되고 있다. 도로살얼음의 형성 메커니즘은 다양한 요인에 따라 복합적으로 작용하며, 당시의 도 로 기상 조건과 도로의 기하학적 구조에 따라 얼음의 형태 및 강도가 결정된다. 그중에서도 도로 노면 온도는 도로살얼음 형성에 중 요한 요소로, 여러 나라에서 겨울철 교통안전 평가를 위한 주요 지표로 사용되고 있다. 그러나 현재 도로 노면 온도에 대한 명확한 정 의가 부족할 뿐만 아니라, 측정 방법에 따라 계측 편차와 온도 손실 등 여러 한계가 존재해 정확한 온도 측정이 어려운 실정이다. 이 에 본 연구는 지중 깊이에 따른 온도 데이터와 도로 기상 데이터를 결합하여 보다 정밀한 도로 노면 온도 예측 방법을 제시하는 것을 목적으로 한다. 연구를 위해 지중 깊이 2cm, 3cm, 4cm, 5cm, 7cm, 9cm, 15cm, 20cm에 각각 온도 센서를 설치하였으며, 기상 데이터는 해당 지점에서 2m 떨어진 AWS(Automatic Weather System)를 통해 대기 온도, 습도, 강수량, 일사량 등의 정보를 수집하였다. 이를 바 탕으로 지중 온도와 기상 조건의 상관관계를 활용하여 노면 온도를 예측하는 방법론을 도출하였다. 본 연구의 결과는 도로 노면 온도 예측의 정확성을 향상시킬 뿐만 아니라, 새로운 접근 방식을 통해 노면 온도의 정의를 재정립하는 데 기여할 것으로 기대된다.
본 연구는 기온 상승에 따른 개별 콘크리트 슬래브의 팽창과 그로 인한 Pavemnent Growth 및 Blow-up 현상을 분석하고 예측하기 위 해 수행되었다. 기온이 상승함에 따라 슬래브는 팽창하며, 콘크리트 슬래브들의 팽창량은 팽창 줄눈 사이에 존재하는 모든 수축 줄눈 이 닫히게 될 정도로 발생하게 되고 그 결과 모든 슬래브들이 접촉하게 된다. 온도의 추가적인 증가로 슬래브가 계속해서 팽창하게 되면 팽창 줄눈의 수축 허용 폭을 초과하는 경우 일체화된 슬래브 내에서 압축 응력이 발생하게 되며, 이러한 현상을 "Pavement Growth"라 정의된다. 이로 인해 콘크리트 포장은 팽창하면서 파손이나 균열에서 좌굴 및 파괴와 같은 압력 관련 문제를 일으킬 수 있 다. 이는 교량 및 도로 내 접근 구조물과 같은 인접 구조물에도 손상을 줄 수 있다. 그러나 현재 사용 가능한 이론적 해결책이나 Pavement Growth 평가 방법과 Blow-up 예측에 관한 연구는 매우 제한적이다. 따라서 본 연구에서는 콘크리트 포장의 팽창을 예측하기 위해 Pavement Growth 및 Blow-up 분석 모델인 PGBA(Pavement Growth and Blow-up Analysis) Model을 개발하였다. 이 모델은 기후 조 건, 포장 구조, 재료, 팽창 줄눈 등의 요인을 고려하였다. 본 모델은 일체화된 슬래브가 팽창하여 팽창 줄눈의 수축 허용 폭을 초과하 는 시기를 결정한다. 슬래브와 기층 사이의 Frictional Darg 및 슬래브의 End Restraint으로 인해 발생하는 압축 응력을 계산 할 수 있는 것이다. 또한 Geometric Imperfection의 변화에 따른 Blow-up Stress를 검토하기 위해 Large-scale Blow-up Test를 진행하였으며, 측정된 결과를 Blow-up 발생 임계값으로 사용하였다. 일체화된 슬래브 내부에 발생하는 연도별 압축 응력을 예측하고 Blow-up Stress와 비교 하여 압축 응력이 Blow-up Stress를 초과하는 시점을 Blow-up 발생 시기로 선정하였다.
몽골은 러시아, 중국과 국경을 맞대고 있는 내륙국가로 해외시장연결을 위해 도로 인프라 구축이 상당히 중요하다. 이에 몽골은 지 난 15년 동안 도로 건설을 지속적으로 추진하였으며 현재 몽골 국가도로 포장율을 약 50%까지 끌어 올렸다. 그러나 몽골은 최근 도로 포장 파손이 증가하고 이에 따른 보수예산이 증가하고 있는 추세인데, 이를 체계적으로 관리할 수 있는 관련 기술이 부재한 상황이다. 이에 본 사업에서는 한국의 30년 이상 축적된 도로관리기술을 기반으로 몽골에 최적화된 관리시스템과 장비를 개발할 계획이다. 이 를 통해 몽골에 디지털 기반 도로관리기술을 안착시키고 장기적으로 몽골의 도로연결성 강화 및 도로상태수준을 증진시키는데 기여하 고자 한다.
Concrete structures must maintain their shielding abilities and structural integrity over extended operational periods. Despite the widespread use of dry storage systems for spent nuclear fuel, research on the properties of deteriorated concrete and their impact on structural performance remains limited. To address this significant research gap, static and dynamic material testing was conducted on concrete specimens carefully extracted from the outer wall of the High-flux Advanced Neutron Application ReactOr (HANARO), constructed approximately 30 years ago. Despite its age, the results reveal that the concrete maintains its structural integrity impressively well, with static compression tests indicating an average compressive strength exceeding the original design standards. Further dynamic property testing using advanced high-speed material test equipment supported these findings, showing the consistency of dynamic increase factors with those reported in previous studies. These results highlight the importance of monitoring and assessing concrete structures in nuclear facilities for long-term safety and reliability.
This study investigated speaking anxiety among advanced Korean language learners in Korean Language Institution classrooms, and the strategies they used to overcome it. The study employed qualitative methodology using online interviews for data collection. The sampling technique involved purposive sampling by selecting 13 Korean learners who had completed an advanced Korean course at TOPIK Levels 5 or 6, with Level 6 being the highest. The interview questions addressed various aspects, including comparisons of speaking skills, anxiety in Korean classrooms, fear of making mistakes, concerns about classmates’ reactions, and anxiety induced by teachers. Thematic analysis was performed by generating initial codes, grouping related codes to uncover potential themes, and highlighting recurring patterns in the participants’ responses. The results revealed three factors that contribute to speaking anxiety: personal reasons, teachers’ classroom approaches, and teaching methods. Advanced learners manage anxiety through three coping strategies: preparation, positive thinking, and seeking support from peers. The study concludes with discussions on the pedagogical implications, limitations, and recommendations for future research in advanced Korean language learning classrooms.
The purpose of this study was to determine the effect of simulation-based Korea advanced life support training on new nurses' knowledge, clinical performance ability, performer confidence, and learning satisfaction. Methods: This is a non-equivalent controlled pre-post quasi-experimental study. A simulation-based CPR training program was applied to 37 new nurses. Results: The experimental group scored lower on emergency management knowledge (83.65±7.61) than the control group (84.55±9.22), which was not significant (t=-4.46, p=.657). However, the clinical performance ability score was significantly higher in the experimental group (109.59±9.98) than in the control group (100.24±11.87) (t=3.581, p <.001). Performer confidence was significantly higher in the experimental group (23.43±3.29) than in the control group (19.90±3.85) (t=3.69, p〈.001). In addition, the learning satisfaction score of the experimental group (96.16±5.64) was significantly higher than the control group (88.42±11.13) (t=3.72, p< .001). Conclusion: This study confirmed that simulation training is an efficient way to improve new nurses' clinical performance ability, and performer confidence. Therefore, applying simulation training in scenarios can improve new nurses' work competence and contribute to improving the quality of patient care.
The Fukushima-Daiichi accident in 2011 revealed the limitations of Zr-alloys in accident scenarios where severe steam oxidation led to the liberation of heat and hydrogen and the destruction of the reactor core. In response to this accident, there has been a concerted effort by industry, national laboratories, and universities to develop cladding and fuel materials for lightwater reactors (LWRs) that are more accident tolerant. The near-term approach has been to develop coatings for Zr-alloys that would provide additional safety and operational margin by virtue of its excellent corrosion/oxidation resistance at both normal and accident conditions. The designs being considered for implementation by major nuclear fuel suppliers include a thin Cr or a ceramic coating on the conventional LWR fuel cladding. For improved economics, the industries are also considering ATF coated cladding with high enrichment fuel (up to 8%) to achieve high burnup (> 75 GWd/MTU). While the development of ATF concepts (i.e., the front end of the fuel cycle), including coated claddings and doped fuels have progressed at an accelerated pace, relatively less attention has been devoted to the used fuel disposition of ATF fuels (i.e., the backend of the fuel cycle). For accelerated deployment of the ATF designs in the current LWR fleet, it is necessary to investigate technical aspects of the ATF used nuclear fuel (UNF) management in transportation, storage, and disposal. This presentation will provide a brief overview of state-of-the-art ATF developments and list out potential considerations to apply the fuels into back-end fuel cycle. New test plan should be planned to compare the characteristics of current LWR used nuclear fuels with those of the new fuel designs. For example, research focus can be understanding of ATF used fuel particulate size and quantity (at high burnup condition) and mechanical integrity of coated cladding under normal and off-normal conditions during transportation and long-term storage. Finally, the impacts of CRUD on the new fuel cladding, increased container weight, temperature, and radiation level to the back-end fuel cycle activities need to be investigated.
The Agency needs to maintain a solid and reliable foundation for recruited inspectors by providing practical training at commercial nuclear power plants. The Comprehensive Inspection Exercise (CIE) is a basic training which consists of a simulation of a Design Information Verification (DIV) Visit, a Physical Inventory Verification (PIV) at a nuclear power plant, including Complementary Access. The basic curriculum includes a pre-course session, auditing exercises, fresh fuel (bundles and assemblies) measurements, spent fuel (bundles and assemblies) measurements, verification of design features, as well as nuclear material flow. ROK has been holding the lightwater reactor (LWR) / heavy-water reactor (CANDU) training course (CIE) from 2010 every year with about 2 weeks curriculum through MSSP (Member State Support Program). LWR and CANDU are operated by KHNP. To efficiently carry out the safeguards, IAEA receives the contribution through the ROK support program and implement R&D for the nuclear material inspection. ROK has been supporting and contributing total 22 tasks to IAEA in-cash and in-kind. Among them, this training provides for a course on safeguards verification activities at CANDU and LWR facilities. This course offers inspectors a unique opportunity to understand diversion scenarios and to familiarize themselves with instruments specifically used at CANDU and LWR facilities (OFPS and DCVD), as well as spent fuel dry storage transfer verification activities and dry storage dual sealing arrangements. KINAC performs PoC (Point of Contact) on behalf of NSSC and coordinates work between IAEA and KHNP. Additionally, KINAC first discusses with KHNP that can host light-water reactors and heavy-water reactors with KHNP at the beginning of each year. In order to hold a successful training, ROK plans and carries out a lot of process including agenda, accommodation, equipment movement, logistics and so on in consultation with the IAEA and facilities.
As a promising anode for sodium-ion batteries (SIBs), cobalt sulfide ( CoS2) has attracted extensive attention due to its high theoretical capacity, easy preparation, and superior electrochemical activity. However, its intrinsic low conductivity and large volume expansion result in poor cycling ability. Herein, nitrogen-doped carbon-coated CoS2 nanoparticles (N–C@ CoS2) were prepared by a C3N4 soft-template-assisted method. Carbon coating improves the conductivity and prevents the aggregation of CoS2 nanoparticles. In addition, the C3N4 template provides a porous graphene-like structure as a conductive framework, affording a fast and constant transport path for electrons and void space for buffering the volume change of CoS2 nanoparticles. Benefitting from the superiorities, the Na-storage properties of the N–C@CoS2 electrode are remarkably boosted. The advanced anode delivers a long-term capacity of 376.27 mAh g− 1 at 0.1 A g− 1 after 500 cycles. This method can also apply to preparing other metal sulfide materials for SIBs and provides the relevant experimental basis for the further development of energy storage materials.
Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×102 mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.
Due to the introduction of Smart Advanced Life Support in 2015, paramedics can provide Advanced Cardiovascular Life Support to patients with out-of-hospital cardiac arrest. Although studies have been conducted to confirm the effectiveness of Smart Advanced Life Support for patients with out-of-hospital cardiac arrest, there is a lack of exploration of the experiences that paramedics face in the field in a changed environment. In this paper, I report two cases experienced by paramedics when using Smart Advanced Life Support, including communication with uncooperative caregivers and the burden felt by paramedics. In addition, to promote Smart Advanced Life Support, I propose enhancing paramedic training, establishing communication guidelines with caregivers, expanding the promotion of Smart Advanced Life Support, and providing customized education for the elderly.