• Title/Summary/Keyword: Flash Point

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Study on Characteristics of Change of Physical/Chemical Property in Domestic Aviation Fuel by the Quality Monitoring Analysis (국내 항공유(Jet A-1) 품질모니터링을 통한 물성 변화 특성 연구)

  • Doe, Jin-woo;Youn, Ju-min;Jeon, Hwa-yeon;Yim, Eui-soon;Lee, Joung-min;Kang, Hyung-kyu
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1327-1337
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    • 2018
  • Aviation fuel oil is more strictly controlled than other transport fuels because it can lead to major accidents in the event of a problem. The quality standards of the aircraft are specified by the domestic Korean Standard, the American Society for Testing and Materials and the International Air Transport Association, respectively. From 2016 to 2017, the quality analysis of 6 items such as aromatic content, sulfur content and distillation characteristics was carried out on the jet fuel produced at five domestic refineries. Domestic production of jet fuel has been shown to be in conformity with the quality standards and has been maintained at a constant level throughout the year. Compared with the specification of ASTM and IATA the aromatic content of domestic KS specification is set to be strictly 1.5 wt% higher than the ASTM and IATA setting specification, but it satisfies this specification sufficiently. In addition, other items such as sulfur content, distillation property and flash point satisfied both domestic and international specification.

Evoked Potentials before the Intractable Epilepsy Surgery (난치성 뇌전증 환자에서 수술 전 유발전위검사)

  • Lim, Sung Hyuk;Park, Sang Ku;Baek, Jae Seung;Kim, Kab Kyu;Kim, Ki Eob;Lee, Yu Ji
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.2
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    • pp.198-204
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    • 2019
  • Various treatments can be attempted in patients with intractable epilepsy, in whom the symptoms of seizures are not controlled by various drugs. On the other hand, in patients requiring a surgical method, a preoperative examination is needed to determine the portion of seizure site to be resected. Electrodes are inserted into the cerebral cortex for accurate lesion measurements and safe operation. The electrodes inserted in the cortex not only record the electroencephalography (EEG), but also allow various tests to confirm the function of the part. One of these methods is the evoked potential test. From January 2015 to December 2018, the trends of measured waveforms in were analyzed 70 patients. The somatosensory evoked potential (SSEP) recorded on the electrode inserted in the cerebral cortex can be searched for the pathway of the central sulcus to avoid the primary motor area and primary sensory area. In addition, using the middle latency auditory evoked potentials (MLAEP) and flash visual evoked potentials (FVEP), the functional cortex in the auditory cortex and the visual cortex were compared with the seizure focus point on the EEG to help determine the location of the ablation and minimize functional impairment after surgery.

A Study on the Quality Analysis of Biodiesel for Ship's Fuel Utilization (바이오디젤의 선박 연료 활용을 위한 품질 분석)

  • Ha-seek Jang;Won-ju Lee;Min-ho Lee;Yong-gyu Na;Chul-ho Baek;Beom-seok Noh;Jun-soo Kim
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.4
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    • pp.348-355
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    • 2023
  • Biodiesel is known as an environmentally friendly neutral fuel, and a policy of obligatory mixing of a certain ratio is implemented on land. In this study, to verify the feasibility of using biodiesel as a ship fuel, component analysis, metal corrosion test, and storage stability test were performed on the mixing ratios of 0 %, 5 %, 10 %, and 20 % of marine diesel and biodiesel. Component analysis evaluated a total of eight factors including density, kinematic viscosity and flash point according to ISO 8217:2017 standards and the reliability of biodiesel through metal corrosion tests and storage stability tests under atmosphere temperature and harsh conditions (60 ℃) for 180 days. Results demonstrate that component analysis satisfied the ISO 8217:2017 standard in all biodiesel mixing ratios. Furthermore, as the biodiesel mixing ratio increased, the kinematic viscosity, density, and acid value increased and the sulfur content decreased. Metal corrosion rarely occurred in the case of carbon steel, iron, aluminum, and nickel, whereas in the case of copper, corrosion occurred under the influence of oxygen-rich biodiesel under the harsh conditions (60 ℃) of 20 % biodiesel mixture. As for storage stability, discoloration, sludge formation, and fuel separation were not visually confirmed.

Development of Children Food Safety Education Program for 4th and 5th Grade Elementary School Students in Daegu and Evaluation of Its Effects (대구지역 초등학교 4, 5학년 대상 어린이 식생활 안전관리 교육 프로그램 개발 및 효과 평가)

  • Kim, Jung-Mi;Lee, Nan-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.2
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    • pp.213-220
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    • 2012
  • This study was conducted on 4th and 5th grade elementary school students in Daegu, Korea for the purpose of promoting health and proper dietary habits. A children food safety education program was developed and its effects evaluated on 4th and 5th graders (3,932 students for 4th year, 4,438 students for 5th year) at 46 elementary schools, which were under the jurisdiction of the four educational bureaus of Daegu city. Education was conducted in accordance with an education design plan, of which there were two goals, including know the contents of 'special act on children's dietary life safety management' and 'practice proper hand-washing'. 'Special act on children's dietary life safety management' was explained, and the education curriculum included proper hand-washing for prevention of food poisoning, quality certification mark on children's favorite foods, harmful foods such as unsanitary and adulterated foods, and green food zone. Flash songs, PowerPoint, 'glitter burger' notice note, and banner were used as education media. It was found that the awareness level of items related to 'special act on children's dietary life safety management' increased significantly after education (p<0.001). 'Necessity of nutrition education and children's food safety' also increased significantly (p<0.05) after education. Lastly, children answered that they washed their hands more often after education (62.9%) than before (60.7%).

P300 speller using a new stimulus presentation paradigm (새로운 자극제시방법을 사용한 P300 문자입력기)

  • Eom, Jin-Sup;Yang, Hye-Ryeon;Park, Mi-Sook;Sohn, Jin-Hun
    • Science of Emotion and Sensibility
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    • v.16 no.1
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    • pp.107-116
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    • 2013
  • In the implementation of a P300 speller, rows and columns paradigm (RCP) is most commonly used. However, the RCP remains subject to adjacency-distraction error and double-flash problems. This study suggests a novel P300 speller stimuli presentation-the sub-block paradigm (SBP) that is likely to solve the problems effectively. Fifteen subjects participated in this experiment where both SBP and RCP were used to implement the P300 speller. Electroencephalography (EEG) activity was recorded from Fz, Cz, Pz, Oz, P3, P4, PO7, and PO8. Each paradigm consisted of a training phase to train a classifier and a testing phase to evaluate the speller. Eighteen characters were used for the target stimuli in the training phase. Additionally, 5 subjects were required to spell 50 characters and the rest of the subjects were to spell 25 characters in the testing phase. Classification accuracy results show that average accuracy was significantly higher in SBP as of 83.73% than that of RCP as of 66.40%. Grand mean event-related potentials (ERPs) at Pz show that positive peak amplitude for the target stimuli was greater in SBP compared to that of RCP. It was found that subjects tended to attend more to the characters in SBP. According to the participants' ratings on how comfortable they were with using each type of paradigm on 7-point Likert scale, most subjects responded 'very difficult' in RCP while responding 'medium' and 'easy' in SBP. The result showed that SBP was felt more comfortable than RCP by the subjects. In sum, the SBP was more correct in P300 speller performance as well as more convenient for users than the RCP. The actual limitations in the study were discussed in the last part of this paper.

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