• Title/Summary/Keyword: critical means

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Can a nanofluid enhance the critical heat flux if the recirculating coolant contains debris?

  • Han, Jihoon;Nam, Giju;Kim, Hyungdae
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1845-1850
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    • 2022
  • In-vessel corium retention (IVR) during external reactor vessel cooling (ERVC) is a key severe accident management strategy adopted in advanced nuclear power plants. The injection of nanofluids has been regarded as a means of enhancing CHF when using the IVR-ERVC strategy to safeguard high-power nuclear reactors. However, a critical practical concern is that various types of debris flowing from the contaminant sump during operation of an ERVC system might degrade CHF enhancement by nanofluids. Our objective here was to experimentally assess the viability of nanofluid use to enhance CHF in practical ERVC contexts (e.g., when fluids contain various types of debris). The types and characteristics of debris expected during IVR-ERVC were examined. We performed pool boiling CHF experiments using nanofluids containing these types of debris. Notably, we found that debris did not cause any degradation of the CHF enhancement characteristics of nanofluids. The nanoparticles are approximately 1000-fold smaller than the debris particles; the number of nanoparticles in the same volume fraction is 1 billion-fold greater. Nanofluids increase CHF via porous deposition of nanosized particles on the boiling surface; this is not hindered by extremely large debris particles.

Research on the Correlation Between Rail Transit Entrances and Urban Form in High-Density Areas

  • Dongzhu Chu;Hong Su
    • International Journal of High-Rise Buildings
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    • v.12 no.1
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    • pp.35-47
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    • 2023
  • The transport system and its infrastructure are not only the fundamental means of sustaining the operation of contemporary cities, but also important drivers for the evolution of urban form. Rail transit, critical to improving the operational efficiency and optimizing the spatial layout in cities, is one of the critical conditions for high-density areas with limited land and concentrated resources to be compact to take on complex challenges. As a node element of infrastructure, rail transit entrances are the most important points connecting the rail transit system with urban space. Although influenced by urban form, their quantity and location also influence and shape the evolution of urban space form. Based on the development gap of high-density areas in various contexts, focusing on various rail transit stations in Asia, this research analyzes the correlation between rail transit entrances and peripheral high-density urban form in a delicate, dynamic and granular way. The research considers both horizontal and vertical perspectives, in combination with the urban evolution process in time series, to explore the development trend of high-density urban form in Asia from the aspect of correlation, and building a new foundation for research on urban form, suitable for different types of cities.

The Importance of Anonymity and Confidentiality for Conducting Survey Research

  • Eungoo KANG;Hee-Joong HWANG
    • Journal of Research and Publication Ethics
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    • v.4 no.1
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    • pp.1-7
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    • 2023
  • Purpose: Poor anonymity and confidential strategies by a researcher not only develop unprecedented and precedented harm to participants but also impacts the overall critical appraisal of the research outcomes. Therefore, understanding and applying anonymity and confidentiality in research is key for credible research. As such, this research expansively presents the importance of anonymity and confidentiality for research surveys through critical literature reviews of past works. Research design, data and methodology: This research has selected the literature content approach to obtain proper literature dataset which was proven by high degree of validity and reliability using only books and peer-reviewed research articles. The current authors have conducted screening procedure thoroughly to collect better fitted resources. Results: Research findings consistently mentioned the confidentiality and anonymity principles are preserved and implemented as a means of protecting the privacy of all individuals, establishing trust and rapport between researchers and study participants, as a way of critically upholding research ethical standards, and preserving the integrity of research processes. Conclusions: Confidentiality and anonymity are research ethical principles that help in providing informed consent to participants assuring subjects of the privacy of their personal data. As provided by research bodies and organizations, every research process has to incorporate the principles to meet credibility.

A Study on Impact of Nursing Work Environment, Interpersonal Skills, and Grit on Field Adaptation of Nurses Who Have Experienced Department Transfers (부서이동을 경험한 간호사의 간호근무환경, 대인관계능력, 그릿이 현장적응에 미치는 영향)

  • Lee, Su Jeong;Lee, Yun Mi
    • Journal of Korean Critical Care Nursing
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    • v.17 no.2
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    • pp.71-82
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    • 2024
  • Purpose : This study aims to identify the factors influencing field adaptation among nurses who have undergone department transfers, by examining the levels of and the relationships between their nursing work environment, interpersonal skills, grit, and field adaptation. Methods : The study involved 137 nurses who had experienced at least one department transfer within the last three years across two hospitals. Data analysis was performed using SPSS/WIN 29.0, involving descriptive statistics, means, standard deviations, independent t-tests, one-way ANOVA, Scheffé post-hoc tests, Pearson correlation coefficients, and multiple regression analysis (enter method). Results : Factors affecting field adaptation included the nursing work environment (β=.37, p<.001), interpersonal skills (β=.19, p=.021) and grit (β=.18, p=.025), with a total explanatory power of 31% (F=12.16, p<.001). Conclusion : This study contributes insights into effective nursing personnel management, offers foundational data for managing department transfers, and aims to improve the overall quality of nursing care.

A Study on the Triage and Statitical Data of Patients in the Emergency Room, PNU (일 종합병원 응급실 이용환자의 중증도 분류)

  • 김영혜;이화자;조석주
    • Journal of Korean Academy of Nursing
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    • v.31 no.1
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    • pp.68-80
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    • 2001
  • The purpose of this study is to analyze ER patient's Triage and other statistical data. The subjects were 12,618 patients who visited the ER during the year 1998. The study showed the following results; 1. The male vs female ratio was 1.3 : 1.0, the male were in the majority (56.6%), and the age range of 20-29 old was the majority (15.3). The patients who visited ER at 8-10 pm were the majority (11.5%). On Sunday the number of patients who visited the ER were 2,189, and the majority were 17.4%. On Saturday the number of patients was visited the ER were 1,944 patients the second majority (15.4%). Their traffic means : the general passenger cars (75.5%), 119 or hospital ambulance (11.3%). 2.The reasons of visiting ER were : diseases (59.2%), injuries (23.7%). The disease vs injury ratio was 100 : 69. 3. Triage : urgent 40.7%, non-urgent 38.2%, acute 17.8%, and critical 3.2%. 4. The time of waiting and staying in the ER by the Triaget: the average time was 572 minutes (9.53 hrs.). The majority of critical patients (20.5%), acute patients (24.7%) and urgent patients (21.2%) stayed 12-24 hrs., but the majority of non-emergent (27.8%) stayed not longer than one hour. 5. Treatments by the Triage : the 42.9% of critical patients, and 61.3% of acute patients, 57.5% of urgent patients were admitted. But 91.8% of the non-emergents were discharged and 4.7% was admitted. Mortality of total ER visiter were 1.7%. DAA portion was 0.86%. 26.6% of the critical patients were DAA. DAA vs DOA ratio was 1.3 : 1.0. 6. Visiting time, monthly and seasonal distribution by the Triage : the majority of critical patients (12.2%), visited 10-12 am. The majority of acute (12.9%) and urgent (11.7%) visited 4-6 pm, but the majority of non-emergents (15.1%) visited during 8-10 pm. Autumn visiter were the majority (27.6%). The percentage of non-emergent visited in Spring was 41.4% and Autumn was 41.3%. The percentage of urgents who visited in the Summer was 45.3% and the Winter was 40.4%. By clinical departments: the 48.0% of critical patients was NS. The 45.5% of acute and the 33.6% of urgent patients were IM. But the majority of non-emergent patients was PS (21.2%), and the second majority of non-emergent patients was oral Surgery (12.8%).

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Types of Educational Ministry for The Post Digital Generation (포스트 디지털 세대에 대한 교육목회 유형)

  • Lee, Wonil
    • Journal of Christian Education in Korea
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    • v.70
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    • pp.11-35
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    • 2022
  • The purpose of this article is to suggest nine types of educational ministry based on the practical theology in Christian Education. For the purpose this article emphasizes an individual dimension including church, society dimensions. An individual dimension is based on the spirit of post digital era within sociocultural area in different with personal-existential area of the philosophical and theological perspective and life cycle theology area of the developmental psychological perspective. Post digital era means the humanization of digital, digital friendly, and emotional digital cultural characteristics. Post digital generation means child, youth, young adults those who are accustomed with post digital cultural of the post digital era. The educational ministry for the post digital generations categorized into nine types according to correlation with individual, church, and society as a field of ministry and critical scientific method, critical confessional method, and critical correlational method as an interdisciplinary which are composed of Christian tradition and contemporary science. Representative key competencies of nine types in the educational ministry are media literacy, relational identity, communication, high touch, discipleship, making and using media, integrative vocation, collaboration abilities, and home, school, and social resilience in relation with multicultural generations.

기술축적과정에서의 사용자-생산자 관계 : 우리나라 기계제어 컴퓨터 사례

  • 임채성
    • Journal of Technology Innovation
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    • v.9 no.1
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    • pp.149-165
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    • 2001
  • This paper analyses characteristics of the numerical controller industry in market formation and the flow of information between users and producers and the characteristic of knowledge base of the industry and discuses the difficulties derived, from the characteristics, in accumulation of technological capability. In market formation between users and producers, the multi-layered market is not favorable to domestic producers in that lower end market is not large enough to provide cradle market to them which produce inferior quality and lower price than imported products. The credibility of the performance of a product is different to prove until a critical mass of products are sold. Therefore gaining market share is deterred by unproven credibility of the performance of the product. The flow of information between users and producers is limited. The flow of information on users environment through mass market to producers is essential for improving credibility of a product. The nature of knowledge base is tacit and the means of knowledge transmission is limited. Technological licensing and reverse engineering, which have been conventional means of knowledge transmission, are not useful in the numerical controller industry. These characteristics provide conditions of vicious circle in accumulation of technological capability of the numerical controller industry. This paper argues that these characteristics of the industry challenge existing approach to R&D management and framework of science and technology policy.

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Development of Advanced Vehicle Tracking System Using the Uncertainty Processing of Past and Future Locations

  • Kim Dong Ho;Kim Jin Suk
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.729-734
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    • 2004
  • The e-Logistics means the virtual business activity and service architecture among the logistics companies based on the Internet technology. The management of vehicles' location in most conventional vehicle tracking system has some critical defects when it deals with data which are continuously changed. It means the conventional vehicle tracking system based on the conventional database is unable eventually to cope with the environment that should manage the frequently changed location of vehicles. The important things in the evaluation of the vehicle tracking system is to determine the threshold of cost of database ,update period and communication period between vehicles and the system. In other words, the difference between the reallocation of vehicle and the data in database can evaluate the overall performance of vehicle tracking systems. Most of the previous works considers only the information that is valid at the current time, and is hard to manage efficiently the past and future information. To overcome this problem, the efforts on moving objects management system(MOMS) and uncertainty processing have been started from a few years ago. In this paper, we propose an uncertainty processing model and system implementation of moving object that tracks the location of the vehicles. We adopted both linear-interpolation method and trigonometric function to chase up the location of vehicles for the past time as well as future time, respectively. We also explain the comprehensive examples of MOMS and uncertainty processing in parcel application that is one of major application of e-Logistics domain.

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Varietal Differences of Soybean in A-Values (대두(大豆)의 품종별(品種別) A-value에 대하여)

  • Ahn, H.S.;Chung, H.T.;Lee, C.Y.
    • Applied Biological Chemistry
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    • v.13 no.3
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    • pp.261-268
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    • 1970
  • 1. A-value in the soils studied in this experiment were found to be about 40-50kg/10a (as $P_2O_5$) 2. Percentage of utilized phosphorus in Soybeans was 10%. 3. The utilization and A-value of phosphorus were very different among the varieties of soybean plants, and the range was about 30%. 4. A/M-value (A means maximum value of total amount of available phosphorus and M means minimum value of absorbed phosphorus by plants from soils) indicated the critical range of available phosphorus to the crops.

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Policy-based End-to-End QoS Provision for 3G Networks Using DiffServ-aware MPLS (3G 네트워크상에서 정책기반 End-to-End QoS 지원을 위한 DiffServ-aware MPLS)

  • Choi Sung-Gu;Jun Kyung-Koo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.4B
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    • pp.349-354
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    • 2006
  • In 3G networks interworking with external IP-based networks, provision of end-to-end QoS to packet-based services is a critical issue. In this paper, we propose DiffServ-aware Multiple Protocol Label Switching(MPLS) as a new policy enforcement means. With the adoption of the proposed DiffServ-aware MPLS, it is feasible to provide differentiated QoS provision with the help of DiffServ as well as to improve network utilization by using multiple paths based on MPLS. We verify the effectiveness of our proposed policy enforcement means through a simulation in which realtime traffic and non-realtime traffic are served together.