• Title/Summary/Keyword: Fire Point

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Effect of $Al_2O_3$ Particle Size on Thermal Properties of Glass-Ceramics for LTCC Material (저온동시소성용 결정화 유리의 필러 사이즈가 열적 특성에 미치는 영향)

  • Kim, Jin-Ho;Hwang, Seong-Jin;Lee, Sang-Wook;Kim, Hyung-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.281-281
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    • 2007
  • Low Temperature Co-fired Ceramic (LTCC) technology has been used in electronic device for various functions. LTCC technology is to fire dielectric ceramic and a conductive electrode such as Ag or Cu thick film below the temperature of $900^{\circ}C$ simultaneously. The glass-ceramic has been widely used for LTCC materials due to its low sintering temperature, high mechanical properties and low dielectric constants. To obtain the high strength, addition of filler, the microstructure should have various crystals and low pores in a composite. In this study, two glass frits were mixed with different alumina size(0.5, 2, 3.7um) and sintered at the range of $850{\sim}950^{\circ}C$. The microstructure, crystal phases, thermal and mechanical properties of the composites were investigated using FE-SEM, XRD, TG-DTA, Dilatomer. When the particle size of $Al_2O_3$ filler increased, the starting temperatures for the densification of the sintered bodies, onset point of crystallization, peak crystallization temperature in the glass-ceramic composites decreased gradually. After sintered at $900^{\circ}C$, the glass frits were crystallized as $CaAl_2Si_2O_8\;and\;CaMgSi_2O_6$. The purpose of our study is to understand the relationship between the $Al_2O_3$ particle size and thermal properties in composites.

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A Research on the rule of following of three ${\breve{U}}m$ and three Yan (삼음삼양(三陰三陽)의 종화규율(從化規律)에 관한 연구(硏究))

  • Kim, Ho-Hyun
    • Journal of Oriental Physiology
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    • v.14 no.2 s.20
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    • pp.99-116
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    • 1999
  • This study was undertaken to define the expression rule of six vital substances for human life(六氣) in Meridians and the rule of following of three ${\breve{U}}m$ and three Yan. In order to investigate the expression rule of six vital substances for human life(六氣), incident(標)-fundamental(本) and Ki of middle energizer(中氣) of three ${\breve{U}}m$ and three Yang(三陰三陽) were reviewed. 1, The rule of following is formed centering around fundamental Ki(本氣) between incident(標) and fundamental(本). And in case the ${\breve{U}}m$ and Yang (陰陽) disposition of incident(標) and fundamental(本) is different, whether the ${\breve{U}}m$ and Yang(陰陽) disposition of incident(標) and fundamental(本) is same as those of Ki of middle energizer(中氣), is the key point in following fundamental and activating of the vital energy(氣化). 2. As twelve channels(十二經脈) have not only fundamental Ki(本氣) but also Ki of middle energizer(中氣) at the same time, in expression of six vital substances for human life(六氣), if the fundamental Ki(本氣) is stronger, fundamental Ki(本氣) can be expressed or if the fundamental Ki(本氣) is weaker, Ki of middle energizer(中氣) can be expressed. 3. Twelve channels which is connected with each other through the relation of the interior and the exterior can be regarded as a system, in which Wind(風) and Fire(火), Dryness(燥) and Dampness(濕), Cold(寒) and Heat(熱) maintain balance through mutual control. 4. We can see that in the disease caused by the unbalance of six vital substances for human life(六氣), expression of six pathogenic factor and controlment of six vital substances for human life(六氣) are made up after the following one in the rule of following(從化規律).

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Effect of pre-hospital BLS simulation training on the paramedic's competency

  • Jung, Jun-Ho;Cho, Byung-Jun
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.1
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    • pp.103-109
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    • 2018
  • The purpose of the study is to investigate the effect of a simulation training of BLS in paramedics in pre-hospital situation. This a nonequivalence control quasi-experimental study. The study subjects were 8 paramedics of experimental group and 8 paramedics of control group in K fire department. An informed consent was written by the subjects after explaining of the purpose of the study. The study methods consisted of conventional education and practice training. The conventional education was done for 30 minutes and the practice training was taken by four trainees of one group and the instructor demonstrated Basic Iife Support (BLS) performance for three minutes. Each trainer peformed BLS for ten minutes. In the beginning of the course, two paramedics got off from the ambulance and performed BLS including 5 cycles of Cardiopulmonary Resuscitation (CPR). Soon after the BLS, another two paramedics performed pre-hospital BLS survey. The education was guided by two professors of emergency medical technology, two Basic Iife Support instructors, and two emergency rescue directors. Pre-hospital BLS was measured by a 5-point Likert scale. Higher score means higher performance skills. The data were analyzed using SPSS/WIN 22.0 program set at significance level of p<05. The effect of simulation education was much more significant than the conventional education in BLS. The simulation education is very important and effective in improving the clinical performance skills of paramedics than the conventional education. The simulation education can provide the virtual environment of cardiac arrest to the paramedics. In conclusion, the simulation education can provide the effective teaching methods for various practice performance skills and solution by critical thinking in the paramedics and healthcare providers in the future.

Manufacturing of artificial lightweight aggregate from water treatment sludge and application to Non-point treatment filteration (정수슬러지를 재활용한 인공경량골재의 제조 및 비점오염원 여재의 적용)

  • Jung, Sung-Un;Lee, Seoung-Ho;Namgung, Hyun-Min
    • Industry Promotion Research
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    • v.6 no.4
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    • pp.1-9
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    • 2021
  • The purpose of this study is to manufacture lightweight aggregates for recycling water treatment sludge, to identify the physical properties of the aggregates, and present a method of utilizing the manufactured lightweight aggregates. The chemical composition and thermal properties were examined via a raw materials analysis. The aggregate examined here was fired by the rapid sintering method and the single-particle density and water absorption rate were measured. Water treatment sludge has high ignition loss and high fire resistance. When 30wt% of purified sludge was added, the single-particle density of the aggregates was in the range of 0.8~1.2g/cm3 at a temperature of 1,150~1,200℃. At temperatures of 1200℃ or higher, ultra-light aggregates having a single-particle density of 0.8 or less could be produced. When applied to concrete by replacing the general aggregate in the concrete, a specimen having strength values of 200 to 450 kgf/cm2 on 28 days was obtained, and when applied as a filter material, the performance was equal to or higher than that of ordinary sand.

The Dialectic of Immersion and Fire in Traditional Puppetry : Focusing on Brecht's Theory of Effectiveness (전통인형극 <꼭두각시놀음>에 나타난 몰입과 소격의 변증법 -브레히트의 소격효과이론을 중심으로-)

  • Choi, Bae-Suk
    • The Journal of the Korea Contents Association
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    • v.19 no.3
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    • pp.197-212
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    • 2019
  • This study points out how the two conflicting elements of empathy and estrangement that constitute the dual structure of are incorporated by dialectic; finally, this paper explores the spontaneous estrangement effects' meaning and value on the point of view of reception aesthetics. As results of these studies, First, the Brechtian set of estrangement effects techniques showed that in it could function as an empathy technique for audiences. Second, the role of Sanbazi to increase the audience's participation was to produce both the immersion effect and the estrangement effect simultaneously. These double features of Sanbazi are dialectically incorporated and simultaneously bring about both the social reality reflection and enjoyment of the audience. Third, the puppetry is valid as not a way to describe reality but one of the ways to look at social reality. Conclusionally, in terms of producing counter-discourse, the puppet show has more extensible than any other form of performance with regard to expression.

Perception of child abuse and attitudes towards mandatory reporting among 119 emergency medical technicians (119구급대원의 아동학대 인식 및 신고의무태도에 관한 연구)

  • Kim, Tae-Hyun;Cho, Keun-Ja
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.2
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    • pp.43-59
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    • 2019
  • Purpose: The purpose of this study was to assess 119 emergency medical technicians' perception of child abuse, attitudes towards mandatory reporting, and perceptions of mandatory reporting system, and to promote early reporting. Methods: The questionnaire was filled out by one hundred ninety 119 EMTs with paramedic or nurse licenses. The questionnaire consisted of 53 items with responses based on a five-point scale. Data were collected from July 10 to July 31, 2018, and were analyzed using IBM SPSS version 24.0 software. Results: The average score for 119 EMT's perception of child abuse was 3.76. The average score for positive attitude towards mandatory reporting was 3.63, and the average score for negative attitude towards mandatory reporting was 2.63. The average score for perceptions of the mandatory reporting system was 3.50. There was a significant positive correlation between perception of child abuse and positive attitude towards mandatory reporting (r=.244, p=.001), between perception of child abuse and perceptions of the mandatory reporting system (r=.209, p=.004), and between positive attitude towards mandatory reporting and perceptions of mandatory reporting system (r=.336, p=.000). Conclusion: Systemic educational programs for 119 EMTs on perception of child abuse and reporting are needed. It is very important to establish institutional strategies such as the use of checklist for suspicion of child abuse, procedural simplicity after reporting, and protection of reporter information.

Effect of chest compressions on the quality of back pain prevention and chest compressions by applying body stabilization Convergence movement (체간안정화 융합운동을 접목한 가슴압박이 요통예방과 가슴압박 품질에 미치는 영향)

  • Hong, Eun-Jeong;Cho, Byung-Jun;Kim, Gyoung-Young
    • Journal of the Korea Convergence Society
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    • v.10 no.5
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    • pp.85-94
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    • 2019
  • This study was aimed to identify a study on the effect of chest compressions combined with abdominal drawing-in technique on prevention of back pain and chest compression quality. We tested motion analysis, electromyography, and chest compression quality of 15 paramedics. Data were normalized to SPSS 21.0 (Kolmogorov-Smirnov and Shapiro-Wilk test). The paired t-test was used for the pre- and post-test chest compressions, the one-way ANOVA was used for the analysis of the measurement point-in-time differences, and LSD was used for the post-test. The results of the study showed significant difference in muscle activity and chest compression success rate when the chest pressure was applied with abdomen drawing-in. Therefore, it is necessary to study cardiopulmonary resuscitation education which can increase the chest compression success rate while preventing the back pain of the paramedics in the future.

User Preference for Improved Remodeling of Arcade in Traditional Market - Based on user surveys in Daegu Seomun Market - (전통시장 아케이드 공간의 리모델링을 위한 이용자 태도에 관한 연구 - 대구서문시장 이용자 설문을 바탕으로 -)

  • Kim, gyeong-Im;Lee, Jeong-Ho
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.1
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    • pp.27-36
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    • 2020
  • Fifteen years after the modernization of traditional markets, commercial facilities and some 1,000 markets across the country contacted arcade operators, there are no specific guidelines on installation standards, exact guidelines for public facilities, and guidelines on law, maintenance and management yet. Therefore, it is necessary to derive a plan that reflects the mindset of the market project and the users as basic planning data for making arcade remodeling of traditional markets more advanced. As a research method, case studies and surveys were conducted and the details are as follows. Through the case study, this study drew suggestions that were available and needed in Korea on the planning plan of arcade space in the developed traditional market and conducted user preference. The survey participants are 150 users of Daegu seomun market. In addition, the survey contents are approached with the concept of remodeling remuneration, so the total number of questions is 47 including 'accessibility', 'comfort', 'openness', 'safety' and 'integrity', which are five elements of the arcade plan. The survey method assessed the importance and satisfaction of each questionnaire on a 5-point scale, and the survey results were compared with technical statistics and means using the SPSS statistics package. The results of user awareness and image survey, in which the installation and remodeling of the ventilation system of the crosshairs are mentioned in the event of fire or in the case of daily ventilation, are important factors in safety. The user-conscious survey, analyzed in 'integrity', indicates that the use of multi-purpose space is required, and that the layout of street stalls and parking and user movements should be integrated. Mac of this study is going to present direction of remodeling plan and behavior analysis by analyzing user preference data for advanced remodeling of arcade in traditional markets.

Dispersion Model of Initial Consequence Analysis for Instantaneous Chemical Release (순간적인 화학물질 누출에 따른 초기 피해영향 범위 산정을 위한 분산모델 연구)

  • Son, Tai Eun;Lee, Eui Ju
    • Journal of the Korean Society of Safety
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    • v.37 no.2
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    • pp.1-9
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    • 2022
  • Most factories deal with toxic or flammable chemicals in their industrial processes. These hazardous substances pose a risk of leakage due to accidents, such as fire and explosion. In the event of chemical release, massive casualties and property damage can result; hence, quantitative risk prediction and assessment are necessary. Several methods are available for evaluating chemical dispersion in the atmosphere, and most analyses are considered neutral in dispersion models and under far-field wind condition. The foregoing assumption renders a model valid only after a considerable time has elapsed from the moment chemicals are released or dispersed from a source. Hence, an initial dispersion model is required to assess risk quantitatively and predict the extent of damage because the most dangerous locations are those near a leak source. In this study, the dispersion model for initial consequence analysis was developed with three-dimensional unsteady advective diffusion equation. In this expression, instantaneous leakage is assumed as a puff, and wind velocity is considered as a coordinate transform in the solution. To minimize the buoyant force, ethane is used as leaked fuel, and two different diffusion coefficients are introduced. The calculated concentration field with a molecular diffusion coefficient shows a moving circular iso-line in the horizontal plane. The maximum concentration decreases as time progresses and distance increases. In the case of using a coefficient for turbulent diffusion, the dispersion along the wind velocity direction is enhanced, and an elliptic iso-contour line is found. The result yielded by a widely used commercial program, ALOHA, was compared with the end point of the lower explosion limit. In the future, we plan to build a more accurate and general initial risk assessment model by considering the turbulence diffusion and buoyancy effect on dispersion.

Analysis of Development Trends on Bio-based Environmental Transformers Oils in Power Sector (전력분야의 바이오 기반 친환경 전기 절연유 적용에 관한 개발 동향 분석)

  • Kim, Jae-Kon;Min, YoungJe;Kim, Mock-Yeon;Kwark, ByeongSub;Park, Hyunjoo
    • Tribology and Lubricants
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    • v.38 no.2
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    • pp.41-52
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    • 2022
  • Mineral electrical insulating oil, which is widely used in transformers, exhibits excellent cooling performance and transformer efficiency. However, given that it is composed of petroleum-based components, it is weak in terms of biodegradability. This causes environmental problems in case of leakage and a low flash point, which is a factor that would cause great damage in the event of a fire in a substation. In this context, the use of eco-friendly electric insulating oil composed of bio-based vegetable oil and synthetic ester, which has excellent biodegradability and flame retardancy performance, has recently been expanded to the field of electric power, and various research and development (R&D) studies are in progress. According to different research results, vegetable oil and synthetic ester manufacturing technology, thermal stability, oxidation stability, property change, and quality control, which are characteristics of eco-friendly electrical insulating oils, are major factors affecting the maintenance of insulating oil properties. In addition, power companies have established and operated quality control standards according to the use of eco-friendly electrical insulating oil as they expand the exploitatoin of renewable energy in electricity production. In particular, deterioration and oxidation characteristics were jointly identified in R&D as an important influencing factor according to the content of saturated and unsaturated fatty acids present in vegetable oils and synthetic esters in power transformer applications.