The thermal conductivity (TC) of graphene-based/metal composites is currently not satisfactory because of the existence of large interfacial thermal resistance between graphene and metal originating from the strong scattering of phonons. In this work, 6063Al-alloy-based reduced graphene oxide (rGO) composite with strong covalent bonds interface was prepared via self-assembly, reduction, and electrophoresis-deposition processes by using 3-aminopropyl triethoxysilane (APTS) as a link agent. Structural characterizations confirmed the successful construction of strong Al-O-Si-O-C covalent bonds in the as-prepared 6063Al-Ag-APTS-rGO composite, which can promote the transfer of phonons in the interface. Benefiting from the unique structure, 6063Al-Ag-APTS-rGO (214.1 W/mK) showed obviously higher cross-plane TC than 6063Al (195.6 W/mK). Comparative experiments showed that 6063Al-Ag-APTS-rGO has better cross-plane TC than 6063Al/Ag/ APTS/rGO (196.6 W/mK) prepared via physical mixing of stirring process, evidencing the significance of electrophoresisdeposition (EPD) process on constructing strong covalent bonds for improving the heat dissipation performance. Besides, the effects of different rGO contents and test temperature on the TC of the composites and their corrosion resistance were also discussed. This work demonstrated a feasible strategy for the construction of metal–carbon interface composite with improved thermal performance.
CO2 photocatalytic reduction is a carbon–neutral renewable energy technology. However, this technology is restricted by the low utilization of photocatalytic electrons. Therefore, to improve the separation efficiency of photogenerated carriers and enhance the performance of CO2 photocatalytic reduction. In this paper, g-C3N4/Pd composite with Schottky junction was synthesized by using g-C3N4, a two-dimensional material with unique interfacial effect, as the substrate material in combination with the co-catalyst Pd. The composite of Pd and g-C3N4 was tested to have a strong localized surface plasmon resonance effect (LSPR), which decreased the reaction barriers and improved the electron utilization. The combination of reduced graphene oxide (rGO) created a π–π conjugation effect at the g-C3N4 interface, which shortened the electron migration path and further improved the thermal electron transfer and utilization efficiency. The results show that the g-C3N4/ rGO/Pd (CRP) exhibits the best performance for photocatalytic reduction of CO2, with the yields of 13.57 μmol g− 1 and 2.73 μmol g− 1 for CO and CH4, respectively. Using the in situ infrared test to elucidate the intermediates and the mechanism of g-C3N4/rGO/Pd (CRP) photocatalytic CO2 reduction. This paper provides a new insight into the interface design of photocatalytic materials and the application of co-catalysts.
최근 프리팹 부재간 비간섭 계면이음 설계기술이 도입되고 기계주입식 충진 기술의 실용화 성공으 로, 교량 프리캐스트 바닥판 시공의 저해요인이 상당히 해결될 수 있다. 이 때 프리팹 부재에 GFRP 보강근을 적용한다면 가공조립비 절감 효과가 있고, 프리팹 부재의 경량화로 경제성이 제고될 뿐 만 아니라, 현장 안전성과 작업편의성이 향상될 것으로 보인다. 기존 철근 연신율은 20% 내외 수준인데 반해 GFRP 보강근의 파괴변형율은 3% 내외이며 탄성계수는 50GPa (강재 대비 25%수준)이므로, 이 러한 재료특성 차이로 인한 휨성능에 대한 영향 평가가 필요하다. 특히 GFRP 보강근을 프리캐스트 바닥판과 거더 간 계면이음 적용에 따른 영향을 평가하기 위한 프로토타입 거더를 설계하고, 재료간 계면의 부착 특성을 고려한 유한요소해석 모델을 수립하고 극한 휨성능과 소요 계면 전단성능과의 상 관관계를 검토하였다. 추후 본 변수해석 연구에 대해 실험적 검증이 완수된다면, GFRP 보강근 설계기 술을 정립하는 데 기여할 것으로 기대된다.
최근 기술이 발전함에 따라 다양한VR (Virtual Reality) 및AR (Augmented Reality) 장치들이 등장하고 있다. 이 러한 장치들의 대부분의 콘텐츠는 사용자 상호작용을 위해 컨트롤러에 의존하고 있으나 컨트롤러는 휴대하 기 어렵고 분실하기 쉽다는 단점이 있다. 또한, 컨트롤러를 통한 사용자 인터페이스는 장치에 익숙하지 않은 사용자들이 불편함을 느낄 수 있고 새로 인터페이스를 배워야 하는 한계가 있다. 이러한 문제를 해결하기 위 해Oculus Quest는 핸드 트래킹 기술을 도입하여 사용자가 자연스러운 손 제스처를 인터페이스로 사용할 수 있게 하였다. 그러나 핸드 트래킹을 활용하는 방법은 그 어려움 때문에 아직 널리 연구되지 않았고 아직 활 용되지 못하고 있다. 이에 VR 콘텐츠와 상호작용하는 데 손을 사용하는 방법을 탐구하고, 그것을 이용하여 콘텐츠를 만드는 방법을 설명한다
Background: The regulation of maternal immunity is critical for the establishment and maintenance of successful pregnancy. Among many cell types regulating the immune system, innate lymphoid cells (ILCs) are known to play an important role in innate immunity. Although some reports show that ILCs are present at the maternalconceptus interface in humans and mice, the expression and function of ILCs in the endometrium have not been studied in pigs. Methods: Thus, we determined the expression, localization, and regulation of ILC markers, CD127 (a common marker for ILCs), BCL11B (a ILC2 marker), and RORC (a ILC3 marker) at the maternal-conceptus interface in pigs. Results: The expression of BCL11B and RORC, but not CD127, in the endometrium changed during pregnancy in a stage-specific manner and the expression of CD127, BCL11B, and RORC was greatest on Day 15 during pregnancy. CD127, BCL11B, and RORC were also expressed in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. BCL11B and RORC proteins were localized to specific cells in endometrial stroma. The expression of CD127 and BCL11B, but not RORC, was increased by the increasing doses of interferon-γ (IFNG) in endometrial explants. Conclusions: These results suggest that ILCs present at the maternal-conceptus interface may play a role in the establishment and maintenance of pregnancy by regulating the innate immunity in pigs.
In the fluid-structure interaction analysis, the finite element formulation is performed for the wave equation for dynamic fluid pressure, and the dynamic pressure is defined as a degree of freedom at the fluid nodes. Therefore, to connect the fluid to the structure, it is necessary to connect the degree of freedom of fluid dynamic pressure and the degree of freedom of structure displacement through an interface element derived from the relationship between dynamic pressure and displacement. The previously proposed fluid-structure interface elements use conformal finite element meshes in which the fluid and structure match. However, it is challenging to construct conformal meshes when complex models, such as water purification plants and wastewater treatment facilities, are models. Therefore, to increase modeling convenience, a method is required to model the fluid and structure domains by independent finite element meshes and then connect them. In this study, two fluid-structure interface elements, one based on constraints and the other based on the integration of nonsmooth functions, are proposed in nonconformal finite element meshes for structures and fluids, and their accuracy is verified.
Domestic nuclear power plants have developed radiological emergency plans based on the USNRC’s NUREG-0654/FEMA-REP-Rev.1 report and the Korea Institute of Nuclear Safety’s (KINS) research report on radiation emergency criteria for power reactors (KINS/RR-12). NUREG-0654 is a US emergency planning guide for nuclear power plants and provides detailed technical requirements for the content of radiological emergency plans. The document classifies radiological emergencies into three levels: Alert, Site Area Emergency, and General Emergency, which correspond to the white, blue, and red emergency levels used in domestic nuclear power plants. KINS/RR-12 is a technical guidance document published by the Korea Institute of Nuclear Safety in 2012, which divides radiological emergency criteria into criteria for pressurized water reactors (PWRs) and criteria for boiling water reactors (BWRs), and describes in detail the regulatory position and implementation of radiological emergency criteria for domestic PWRs and BWRs. The physical protection-related radiation emergency criteria included in the radiological emergency plan are specified in the radiological emergency criteria guidelines. There are two items each related to white and blue emergencies and one item related to red emergencies. Standard order of emergency plan lists the physical protection-related radiological emergency criteria for domestic PWRs and BWRs, which are identical according to the radiological emergency criteria guidelines. To enhance the physical protection regulation, the legal and regulatory basis for target set identification and vital area identification need to be established by considering radiological and physical protection emergency plan.
The cellular communication network factor (CCN) family proteins regulate many biological events such as angiogenesis, tumor growth, placentation, implantation, and embryogenesis. The expression and function of CCN1, CCN2, and CCN3 at the maternal-conceptus interface are established in humans and rodents, but little is known about the role of CCN4 to CCN6 in the reproductive organs in any other species. Several studies in transcriptome analysis in pigs have shown that the expression of CCN4 and CCN6 increases in the endometrium during early pregnancy. However, their expression, regulation, and function in the endometrium throughout the estrous cycle and pregnancy have not been fully understood in pigs. Thus, we determined the expression, localization, and regulation of CCN4 and CCN6 during the estrous cycle and at the maternal-conceptus interface in pigs. We found that the levels of CCN4, but not CCN6, changed during the estrous cycle. The levels of CCN4 were greater during mid- to late pregnancy than in the early stage, and the levels of CCN6 were greatest on Day 15 of pregnancy. CCN4 and CCN6 were detected in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. CCN4 mRNA was mainly localized to epithelial cells, CCN6 mRNAs to epithelial and stromal cells in the endometrium. In endometrial explant cultures, CCN4 expression was increased by progesterone, and CCN6 expression by interferon-γ. These results suggest that CCN4 and CCN6 may play roles in the establishment and maintenance of pregnancy by regulating the endometrial epithelial cell functions in pigs.
As the 4th industrial revolution emerges, the implementation of smart factories are essential in the manufacturing industry. However, 80% of small and medium-sized enterprises that have introduced smart factories remain at the basic level. In addition, in root industries such as injection molding, PLC and HMI software are used to implement functions that simply show operation data aggregated by facilities in real time. This has limitations for managers to make decisions related to product production other than viewing data. This study presents a method for upgrading the level of smart factories to suit the reality of small and medium-sized enterprises. By monitoring the data collected from the facility, it is possible to determine whether there is an abnormal situation by proposing an appropriate algorithm for meaningful decision-making, and an alarm sounds when the process is out of control. In this study, the function of HMI has been expanded to check the failure frequency rate, facility time operation rate, average time between failures, and average time between failures based on facility operation signals. For the injection molding industry, an HMI prototype including the extended function proposed in this study was implemented. This is expected to provide a foundation for SMEs that do not have sufficient IT capabilities to advance to the middle level of smart factories without making large investments.
Thermal management is significant to maintain the reliability and durability of electronic devices. Heat can be dissipated using thermal interface materials (TIMs) comprised of thermally conductive polymers and fillers. Furthermore, it is important to enhance the thermal conductivity of TIMs through the formation of a heat transfer pathway. This paper reports a polymer composite containing vertically aligned electrochemically exfoliated graphite (EEG). We modify the EEG via edge selective oxidation to decorate the surface with iron oxides and enhance the dispersibility of EEG in polymer resin. During the heat treatment and curing process, a magnetic field is applied to the polymer composites to align the iron oxide decorated EEG. The resulting polymer composite containing 25 wt% of filler has a remarkable thermal conductivity of 1.10 W m− 1 K− 1 after magnetic orientation. These results demonstrate that TIM can be designed with a small amount of filler by magnetic alignment to form an efficient heat transfer pathway.
Identifying plausible scenarios is necessary to evaluate the performance of the repository reliably over a very long period. All features, events, and processes (FEPs) expected in the repository should be comprehensively well-defined and structured into scenarios based on the relation analysis. A platform for the FEP DB management and relation analysis is needed to facilitate the efficient composition of the scenarios. For this purpose, the CYPRUS program was developed, but abandoned due to suspended FEPs and scenario research. Thus, it became necessary to build a new easy-tomaintain platform that inherits the legacy of CYPRUS and reflects the latest research. The data structure and user interface configuration were derived to develop a new platform. The new platform provides extensive data such as the assessment context, the FEP DB, the interaction between FEP contents, the relevance to other project FEPs, the influence on performance, the scenarios for the TSPA, the AMF, and the PA Data. The platform displays the long-term evolution FEPs developed by KAERI, the international and major project FEPs in table format. The correlation between FEP items is composed of a detailed interaction matrix and visualized as the chord diagram or arc diagram. The relevance and linkages between the project FEP items are mapped and presented in the form of network diagrams and network tables. The platform designed in this study will be used to manage the FEP DB, analyze and visualize the relationship between the FEP and scenarios, and finally construct the performance assessment scenarios. It is expected that the platform itself will be used as a part of the knowledge management system and facilitate efficient collaboration and knowledge exchange among experts.
본 연구의 목적은 음성 인터페이스(Voice User Interface, VUI)를 이루는 설계변수 중 사용자에게 긍정적인 감성을 유발하는 설계변수를 확인하는 것이다. 특히, 사용자의 성별과 설계변수의 조절 효과를 분석하여 VUI와 상호작용하는 동안 사용자가 만족할 수 있는 적절한 설계변수 수준을 찾아보고자 하였다. 선행연구를 통해 VUI에 사용되는 음성 설계변수 중에서 사용자의 감성 만족도에 영향을 미칠 수 있는 설계변수 6가지를 도출하였다. 설계변수는 수준을 조절할 수 있도록 Wizard of OZ를 활용하여 VUI 시스템을 구현하였고, 6가지 설계변수의 수준을 조합하여 사용자와 음성으로 대화를 할 수 있도록 구성하였다. 실험에 참여한 사용자는 총 80명으로, 남/여 성비를 고려하여 각 40명씩 모집하였다. 사용자는 VUI와 주어진 임무에 대한 정답을 알아내기 위해 자연스러운 대화를 진행하며, 그동안의 얼굴 표정 변화에 대한 이미지 데이터를 수집 및 표정 분석 소프트웨어를 통해 Valence 점수로 변환하였다. Valence 데이터 를 기반으로 빈도 및 카이제곱 분석을 통해 확인한 결과, 사용자의 성별과 AI gender간의 조절효과가 유의한 것으로 나타났다. 이 결과는 VUI를 설계할 때 사용자의 성별 차이를 고려하는 것이 좋다는 것을 의미한다. 결론적으로, 남성사용자의 경우 성인/남성/높은 톤의 음성, 여성 사용자의 경우 성인/여성/중간톤의 음성이 향후 만족스러운 인터랙션 구현을 위한 VUI 설계에 주요한 가이드라인인 것을 확인하였다. 본 연구의 결과를 통해 향후 다양한 인적 요소를 고려하여 UX 관점에서 인간-AI 상호작용을 보다 섬세하게 분석할 수 있을 것이며, 표정을 통한 실시간 감성 측정을 위한 기초연구로 활용될 수 있을 것이다.
This study aims to propose a conceptual design of information displays for supporting responsive actions under severe accidents in Nuclear Power Plants (NPPs). Severe accidents in NPPs can be defined as accident conditions that are more severe than a design basis accident and involving significant core degradation. Since the Fukushima accident in 2011, the management of severe accidents is increasing important in nuclear industry. Dealing with severe accidents involves several cognitively complex activities, such as situation assessment; accordingly, it is significant to provide human operators with appropriate knowledge support in their cognitive activities. Currently, severe accident management guidelines (SAMG) have been developed for this purpose. However, it is also inevitable to develop information displays for supporting the management of severe accidents, with which human operators can monitor, control, and diagnose the states of NPPs under severe accident situations. It has been reported that Ecological Interface Design (EID) framework can be a viable approach for developing information displays used in complex socio-technical systems such as NPPs. Considering the design principles underlying the EID, we can say that EID-based information displays can be useful for dealing with severe accidents effectively. This study developed a conceptual design of information displays to be used in severe accidents, following the stipulated design process and principles of the EID framework. We particularly attempted to develop a conceptual design to make visible the principle knowledge to be used for coping with dynamically changing situations of NPPs under severe accidents.
In this study, we have prepared a Ti-6Al-4V/V/17-4 PH composite structure via a direct energy deposition process, and analyzed the interfaces using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The joint interfaces comprise two zones, one being a mixed zone in which V and 17-4PH are partially mixed and another being a fusion zone in the 17-4PH region which consists of Fe+FeV. It is observed that the power of the laser used in the deposition process affects the thickness of the mixed zone. When a 210 W laser is used, the thickness of the mixed zone is wider than that obtained using a 150 W laser, and the interface resembles a serrated shape. Moreover, irrespective of the laser power used, the expected phase is found to be absent in the V/17-4 PH stainless steel joint; however, many VN precipitates are observed.
The continuous development of in-vehicle information systems in recent years has dramatically enriched drivers’ driving experience while occupying their cognitive resources to varying degrees, causing driving distraction. Under this complex information system, managing the complexity and priority of information and further improvement in driving safety has become a key issue that needs to be urgently solved by the in-vehicle information system. The new interactive methods incorporating the augmented reality (AR) and head-up display (HUD) technologies into in-vehicle information systems are currently receiving widespread attention. This superimposes various onboard information into an actual driving scene, thereby meeting the needs of complex tasks and improving driving safety. Based on the qualitative research methods of surveys and telephone interviews, this study collects the information needs of the target user groups (i.e., beginners and skilled drivers) and constructs a three-mode information database to provide the basis for a customized AR-HUD interface design.