• Title/Summary/Keyword: target utilization

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Thermal-hydraulic safety analysis of radioisotope production in HANARO using MCNP6 and COMSOL multiphysics: A feasibility study

  • Taeyun Kim;Bo-Young Han;Seongwoo Yang;Jaegi Lee ;Gwang-Min Sun;Byung-Gun Park;Sung-Joon Ye
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.3996-4001
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    • 2023
  • The High-flux Advanced Neutron Application Reactor (HANARO) produces radioisotopes (RIs) (131I, 192Ir, etc.) through neutron irradiation on various RI production targets. Among them, 177Lu and 166Ho are particularly promising owing to their theranostic characteristics that facilitate simultaneous diagnosis and treatment. Prior to neutron irradiation, evaluating the nuclear heating of the RI production target is essential for ensuring the thermal-hydraulic safety of HANARO. In this study, the feasibility of producing 177Lu and 166Ho using irradiation holes of HANARO was investigated in terms of thermal-hydraulic safety. The nuclear heating rates of the RI production target by prompt and delayed radiation were calculated using MCNP6. The calculated nuclear heating rates were used as an input parameter in COMSOL Multiphysics to obtain the temperature distribution in an irradiation hole. The degree of temperature increase of the 177Lu and 166Ho production targets satisfied the safety criteria of HANARO. The nuclear heating rates and temperature distribution obtained through the in silico study are expected to provide valuable insight into the production of 177Lu and 166Ho using HANARO.

Effects of Heat Treatment on the Properties of ITO Films Deposited with Powder Target (분말 타겟을 이용하여 증착된 ITO 박막의 열처리 특성)

  • Lee Jae-Hyeong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.2
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    • pp.109-115
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    • 2006
  • Indium tin oxide (ITO) films have been prepared by DC magnetron sputtering. In order to improve the utilization efficiency of the target and reduce the cost of the film deposition processes, the powder target was used instead of the conventional ceramic target. As-deposited films were annealed at temperatures between $200^{\circ}C$ and $500^{\circ}C$ for 30 min in air. Also, the film was annealed in various atmospheres such as air, $O_2,\;H_2,\;N_2$, and vacuum at $400^{\circ}C$C for 30 min. Effects of the heat treatment conditions on structural, electrical, and optical properties of ITO films were investigated. The annealing temperature of $400^{\circ}C$ and atmospheres of $H_2$ and $N_2$ seem to be the most suitable conditions for post processing.

Challenges and suggestions in dealing with flexible space in predicting space utilization

  • Chen, Xingbin;Kim, Tae Wan
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.299-303
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    • 2015
  • Flexible space is an adaptable space that has been increasingly used in many office and academic buildings as it increases the use of the space available and reduces the unnecessary building area. However, the architectural, engineering and construction (AEC) industry lacks a formalized method that helps architects predict and update the space utilization of flexible space during the project development, as such prediction aims to maximize the use of the building space available without exceeding the target utilization policy. Consequently, current manual utilization prediction results in lower accuracy level and limits the maximized use of the flexible space, which has multiple space-use types that affect the prediction of utilization. To address this problem, we identified eight space-use type differentiators (SUTDs) based on the literature review and observations and discussed the use of them in automated space-use analysis (SUA), which can predict the utilization of flexible space via a computer program. This research builds on SUA and contributes to flexible space planning by providing a means of a more comprehensive and accurate SUA.

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Determinants of Functional MicroRNA Targeting

  • Hyeonseo Hwang;Hee Ryung Chang;Daehyun Baek
    • Molecules and Cells
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    • v.46 no.1
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    • pp.21-32
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    • 2023
  • MicroRNAs (miRNAs) play cardinal roles in regulating biological pathways and processes, resulting in significant physiological effects. To understand the complex regulatory network of miRNAs, previous studies have utilized massivescale datasets of miRNA targeting and attempted to computationally predict the functional targets of miRNAs. Many miRNA target prediction tools have been developed and are widely used by scientists from various fields of biology and medicine. Most of these tools consider seed pairing between miRNAs and their mRNA targets and additionally consider other determinants to improve prediction accuracy. However, these tools exhibit limited prediction accuracy and high false positive rates. The utilization of additional determinants, such as RNA modifications and RNA-binding protein binding sites, may further improve miRNA target prediction. In this review, we discuss the determinants of functional miRNA targeting that are currently used in miRNA target prediction and the potentially predictive but unappreciated determinants that may improve prediction accuracy.

Cathodic Recirculation System Using a Dual-ejector to Improve Oxygen Utilization of a Submarine Fuel Cell

  • Kim, Min-Jin;Sohn, Young-Jun;Lee, Won-Yong
    • Journal of the Korean Electrochemical Society
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    • v.13 no.3
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    • pp.193-197
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    • 2010
  • In terms of the system efficiency, it is very useful to apply the ejector into the fuel recirculation system of a fuel cell system since the ejector needs no parasitic power to operate. Since the conventional automotive fuel cell use hydrogen and air as their fuel, the only hydrogen is needed to be recirculated for the better fuel efficiency. On the other hand, the submarine fuel cell needs both hydrogen and oxygen recirculation systems because the submarine drives under the sea. In particular, the cathodic recirculation has to meet the tougher target since the oxygen based pressurized stack generally used in the submarine applications generates the significant amount of the water in the stack during the operation. Namely, the oxygen utilization has designed less than 50% in the whole operating range for the better exhausting of the generated waters. And thereby in terms of the oxygen utilization, the entrainment ratio of the ejector should be more than 1 within the whole operating range. However, the conventional ejector using a constant nozzle can not afford to satisfy the mentioned critical requirement. To overcome the problem, the dual-ejector and its control strategy are designed. The performance of the proposed dual-ejector is verified by the experiments based on the real operating conditions of the target submarine system. Furthermore, the proposed design method can be used for the other fuel recirculation system of a large-scale fuel cell system with the critical requirement of the fuel utilization.

A Comparative Study of the Utilization Condition and Typical Characteristics after the Closed School in Japan (일본 폐교 이후 활용 현황과 유형적 특징 비교)

  • Sung, Lee-Yong
    • Journal of the Korean Institute of Educational Facilities
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    • v.27 no.3
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    • pp.25-31
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    • 2020
  • The reasons for studying the case of Japan are as follows. First, the increases in the aged population is similar to the case of Korea, and consumers are aging as the population ages. Second, the structure of industry in Japan is very similar to Korea, which describes the fact that the share of the manufacturing industry decreases but the service industry (e.g., medicine, finance, and insurance) increases. Third, Japan is considered as the best predictive model for forecasting the future of closed schools in Korea because the GNI gross income per capita is relatively close to the one of Korea among the several neighboring countries. The purpose of this study is to analyze the current extent of utilizing closed schools in Japan and, based on the analysis, to provide basic data on the use of closed schools in Korea in the future. The types of closed schools can be classified into education facilities, social welfare facilities, cultural facilities, public sports facilities, income growing facilities, and others. Based on the classification, the analyses of the characteristics of each type for the facilities are presented. and When the utilization status of closed schools in Japan is analyzed, 363 schools were utilized (51.4%) in 2003, means the lowest utilization rate of the target year, after that 4198 schools (70.6%) were utilized in 2015. The utilization ratio is steady increased.

Level of Knowledge and Utilization of Fortified Maize Flour by Primary Food Shoppers in Mathare, Nairobi County, Kenya

  • SAMIRA, Hussein;NJOGU, Eunice;MAKWORO, Drusilla
    • The Korean Journal of Food & Health Convergence
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    • v.6 no.2
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    • pp.1-8
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    • 2020
  • Micronutrient malnutrition severely affects development and functioning of the body leading to increased morbidity and mortality. The study adopted a cross-sectional research design; cluster sampling was used to target 318 households. The significance level was P < 0.05, the mean age of primary food shoppers was 33 years and the average income was 3,000-5,000 Kenya shillings. Slightly above half, 55% of the primary food shoppers knew about fortification but only 25% understood its meaning. Fortified maize flour was consumed by < 80% of primary food shoppers however utilization frequency was low. In conclusion factors that were significantly associated with utilization of fortified maize flour included; knowledge on fortified maize flour (p=0.00), household size (p=0.005), preference of fortified maize flour (p=0.000) and level of fortification knowledge (p=0.002). Availability and price were ranked as the most important factors that influence utilization of fortified maize flour at 58% and 55% contrary nutritional value was ranked least important at 37%. The ministry of health and concerned millers should make more emphasis on creating and sustaining awareness more so a steady supply and affordable prices should be ensured by millers so that more primary food shoppers can be able to utilize the fortified maize flour.

Health Care Utilization of Age Group in the Elderly on the Korean Health Panel (한국의료패널 자료를 활용한 노년기 연령그룹에 따른 의료이용)

  • Choi, Ryoung;Hwang, Byung-Deog
    • The Korean Journal of Health Service Management
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    • v.8 no.3
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    • pp.49-61
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    • 2014
  • Due to the rapid population's aging, the life span's expansion and social & cultural characteristics, the standards of age classes in senescence are changed. Thus, this study aimed to identify the influential factors on health care utilization in the elderly by age class, and targeted 2,937 adults in their ages over 55 years old from the Korea Health Panel's 2009 Yearly Integrated Data. This study investigated the target health care utilization in the elderly in relation with the gender, the education level, the health-care insurance type, the income, the current job state, the chronic disease. In order to analyze the influential factors on health care utilization in the elderly, the multiple linear regression analysis was conducted to the data. As the results from this study, Concerning the influential factors on the health care utilization, the income, the subjective health state, the chronic disease and the regularly meals for the young-old influenced. Concerning the influential factors on the health care utilization, the subjective health state for the old. Concerning the influential factors on the health care utilization, the subjective health state, the income for the older-old influenced. Concerning the influential factors on the health care utilization, the education level, the spouse, the economic activity and the drinking oldest-old influenced. Therefore, it will need to provide systemic health-care & medical services, to develop health-care & medical programs and the health-care & medical policies and to execute them according to the age classes in senescence.

A Study on the Appropriateness Evaluation of Utilization of green buffer zone - Focusing on green buffer zone, Daejeon City Seo-gu (완충녹지 활용의 적정성 평가 -대전시 서구 완충녹지를 대상으로)

  • Kim, Sun Min;Lee, Shi Young
    • Land and Housing Review
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    • v.10 no.4
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    • pp.41-50
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    • 2019
  • This study was started to study the buffer zone of Daejeon metropolitan city in order to study the policy and environment for the suitability evaluation of the use of green buffer zone. The target of the study was selected as the buffer zone of western buffer, which is frequently used in the Daejeon Metropolitan City, and a preliminary index was selected to evaluate the suitability of the green buffer zone. AHP analysis was conducted to increase the reliability of the preliminary indicators and the weight was analyzed by questionnaires to experts and practitioners. In addition, based on the existing statistical data, we rebuilt the green buffer zone and investigated the current condition, and compared and analyzed the green buffer zone and the places where they did not. The results are as follow. First, unlike the statute interpretation that construction can not be done in buffered green spaces, green buffer zones have been utilized in various ways. However, the lack of advanced citizen consciousness of the residents, the responsibility of the responsible person, and the problem of the management office alone are causing problems. Second, according to the results of AHP questionnaire analysis, functional and stability among the appropriateness indexes of green buffer zone utilization were evaluated highly. Park accessibility and utilization potential also weighed somewhat, and it was judged that the epochal trend was more important in the use of green buffer zones. Third, analysis of the status of Western green buffer zones in Daejeon showed that the utilization rate was more than half. This suggests the necessity of judging the appropriateness of the application of the green buffer zone effectively due to the change of the perception of the green buffer zone of the residents. Fourth, as a result of comparing and analyzing the site where the site is used and the site where it is not, it is found that it is used within a range that does not greatly affect each index. However, as the stability has decreased, we have decided that the utilization method is most damaging to the green zone, and we should strive to improve the stability in future. Finally, the analysis of a red clay road and a red clay road sites decreased from Class I of stability to Grade II. However, the fall figure showed a difference between the 13 % drop rate of the target location and the 5% decline rate of utilization. The difference was analyzed as the difference of width of a red clay road. This can be regarded as one of the ways of damaging the green zone to the minimum extent, which is a great advantage in selecting the future utilization plan.

Turn-off time improvement by fast neutron irradiation on pnp Si Bipolar Junction Transistor

  • Ahn, Sung Ho;Sun, Gwang Min;Baek, Hani
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.501-506
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    • 2022
  • Long turn-off time limits high frequency operation of Bipolar Junction Transistors (BJTs). Turn-off time decreases with increases in the recombination rate of minority carriers at switching transients. Fast neutron irradiation on a Si BJT incurs lattice damages owing to the displacement of silicon atoms. The lattice damages increase the recombination rate of injected holes with electrons, and decrease the hole lifetime in the base region of pnp Si BJT. Fast neutrons generated from a beryllium target with 30 MeV protons by an MC-50 cyclotron were irradiated onto pnp Si BJTs in experiment. The experimental results show that the turn-off time, including the storage time and fall time, decreases with increases in fast neutron fluence. Additionally, it is confirmed that the base current increases, and the collector current and base-to-collector current amplification ratio decrease due to fast neutron irradiation.