A Quantitative A naly sis of the Fire Hazard Generated from Hydrogen Fuel Cell Electric Vehicles

Sungwook Kang(Sungwook Kang),Kyu Min Lee(Kyu Min Lee),Minjae Kwon(Minjae Kwon),Ohk Kun Lim(Ohk Kun Lim),Joung Yoon Choi(Joung Yoon Choi) 한국화재소방학회 2022 International Journal of Fire Science and Engineer Vol.36 No.2

There is a lack of information on (i) the potential fire load of new green-technology vehicles, (ii) flame spread behavior, (iii) thermal impacts on high-pressure hydrogen storage vessels (HSVs) and lithium-ion batteries (LIBs) during fuel cell electric vehicles fires (FCEVs), and (iv) thermal damage to adjacent vehicles and upper structural members during FCEV fires occurring in civil structures, such as underground spaces, multi-story parks, and tunnels. In view of this, a full-scale fire test was conducted in this study to quantitatively assess the fire risk of hydrogen FCEVs. Large-scale cone calorimetry was used to quantify the thermal intensity released from the FCEV fire. The flame spreading behavior through an FCEV with HSVs and LIBs was observed using the thermocouples installed. Changes in the temperature and irradiance around the FCEV fire were also measured using an instrumented test rig. The peak heat release rate, total heat released, and fire growth rate were observed to be 5.99 MW, 11.8 GJ, and 0.0055 kW/s², respectively. The temporal point of hydrogen gas release from the HSVs' thermal pressure relief device (TPRD) was estimated to be 16.2-26.2 min. The initiation of thermal runaway of LIBs was deduced from the temperature-time profiles of the LIB modules and their metal housing approximately 22.2 min after HCEV ignition. Moreover, FCEV fires could thermally impair adjacent upper structural members by 800 ℃ combustion gas for at least 13 min and emit a median heat flux of 27.2 kW/m² (peak heat flux of 76.5 kW/m²) to adjacent vehicles. The measurements and findings obtained from this study can contribute to the evaluation of and further studies on newly emerging fire hazards.

Comparing hemostatic resuscitation management of intraoperative massive bleeding with traumatic massive bleeding: a computer simulation

Lee Young Sun,Kim Kyu Nam,Lee Min Kyu,Sun Jung Eun,Hyun Jin Lim,전종헌 대한마취통증의학회 2020 Anesthesia and pain medicine Vol.15 No.4

Background: Appropriate blood component transfusion might differ between intraoperative massive bleeding and traumatic massive bleeding in the emergency department because trauma patients initially bleed undiluted blood and replacement typically lags behind blood loss. We compared these two blood loss scenarios, intraoperative and traumatic, using a computer simulation. Methods: We modified the multi-compartment dynamic model developed by Hirshberg and implemented it using STELLA 9.0. In this model, blood pressure changes as blood volume fluctuates as bleeding rate and transcapillary refill rate are controlled by blood pressure. Using this simulation, we compared the intraoperative bleeding scenario with the traumatic bleeding scenario. In both scenarios, patients started to bleed at a rate of 50 ml/min. In the intraoperative bleeding scenario, fluid was administered to maintain isovolemic status; however, in the traumatic bleeding scenario, no fluid was supplied for up to 30 min and no blood was supplied for up to 50 min. Each unit of packed red blood cells (PRBC) was given when the hematocrit decreased to 27%, fresh frozen plasma (FFP) was transfused when plasma was diluted to 30%, and platelet concentrate (PC) was transfused when platelet count became 50,000/ml. Results: In both scenarios, the appropriate ratio of PRBC:FFP was 1:0.47 before PC transfusion, and the ratio of PRBC:FFP:platelets was 1:0.35:0.39 after initiation of PC transfusion. Conclusion: The ratio of transfused blood component did not differ between the intraoperative bleeding and traumatic bleeding scenarios.

고정층 활성탄 흡착반응기에서 기상 톨루엔의 흡착특성

임진관,이송우,감상규,이동환,이민규 한국환경과학회 2005 한국환경과학회지 Vol.14 No.1

Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity. mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

전환장애와 감별해야할 Meige 증후군 1예

임세원,김진세,정인과,박민규,이대희 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.3

Meige 증후군은 안검경련과 구-하악부의 근긴장이상을 특징적으로 보이는 신경학적 임상증후군이다. 발병원인은 아직 불분명하나 아세틸콜린과 도파민의 신경활성과다(excess neuronal activity)가 원인으로 여겨지고 있으며, 치료로는 향도파민성약물과 항콜린성약물, 그리고 보튤리듐독소 주사가 이용되고 있다. 그러나 증상양상이 다양하며 심리적 영향을 받으므로 전환장애 혹은 불안장애 등의 정신과적 문제로 오진되는 경우가 있다. 저자들은 49세 여자로 초기에 전환장애로 진단되었으나 Meige 증후군임이 밝혀져 성공적으로 치료되었던 환자 1례를 경험하여 문헌고찰과 함께 보고한다. A Meige's syndrome is a rare neurological syndrome characterized by blepharospam and oro-mandibular dystonia. Its pathophysiology is not clearly determined yet, but the hypothesis of dopaminergic and cholinergic hyperactivity is most widely accepted. Anticholinergic drugs, antidopaminergic drugs and botulism toxin injection are currently used for the treatment of Meige's syndrome. The Meige's syndrome could be misdiagnosed as a psychiatric disorder such as conversion disorder or anxiety disorder, because clinical features of the Meige's syndrome are very variable and affected by psychological factors. The authors experienced one case of a 49-year-old female patient who was initially misdiagnosed as conversion disorder but confirmed later as Meige's syndrome, and then successfully treated.

혼합액정(80CB+50CB)의 네마틱-스멕틱 A 상전이 근처의 네마틱상에서 휨 탄성상수(K₃)에 관한 광산란 실험연구

임동건,이민규,변영태,유영훈,김두철 濟州大學校 基礎科學硏究所 1990 基礎科學硏究 Vol.3 No.1

액정 8OCB(octyloxycyanobiphenyl)에 액정 5OCB(pentyloxycyanobiphenyl)를 무게비로 혼합하여 혼합액정 (8OCB+5OCB)을 만들었다. 이 혼합액정은 5OCB의 무게비에 따라 McMillan지수 (??)가 감소하였다. 그리고 Rayleigh 광산란 실험방법을 이용하여, 순수 8OCB와 혼합액정의 네마틱-스멕틱 A 상전이 근처의 네마틱상에서 산란된 빛의 세기를 온도와 함수로 측정하였다. 실험데이타 분석결과는 휨(bend) 탄성 상수에 비례하는 세로방향 상관거리(??)는 McMillan 지수에 관계없이 임계지수 ??=0.66±0.03을 갖고 발산하였다. 이 값은 de Gennes의 모델에서 제시된 ??=0.67과 일치함을 알수있다. By utilizing Rayleigh scattering technique, we have measured the temperature dependence of scattered light intensity near nematic to smectic-A phase transition point in the pure 8OCB(octyloxycyanobiphenyl) and its mixtures contaning 5, 10, 15 weight percentage of 5OCB(pentyloxycyanobiphenyl). From analysis of these data. it is found that the longitudinal correlation length (??) diverges with critical exponent ??=0.66±0.03 independent on McMillan parameter (??). This result is consistent with de Gennes model (??).

측두하악장애 환자 중 하악과두의 퇴행성 골 변화를 보이는 환자의 분포 및 임상적 특징

임용규,김민지,김연중,송윤헌,이동렬 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.6

측두하악장애 환자 중 하악과두의 퇴행성 골 변화를 보이는 환자의 분포와 임상적 특징을 규명하고자 측두하악장애로 진단받은 6,070명의 환자들을 대상으로 연구를 시행하였다. 환자들의 초진 시 파노라마와 TMJ 파노라마 사진을 관찰하여 하악과두의 퇴행성 골 변화 유무를 기준으로 환자들을 퇴행성 골 변화를 보이는 군(DJD군)과 골 변화를 보이지 않는 군(non-DJD군)으로 나누고, 환자들의 초진 의무기록을 바탕으로 두 군 간의 특징을 비교, 분석하였으며, 각종 변수들이 DJD 발병에 미치는 상대적 위험성을 측정하기 위하여 로지스틱 회귀분석을 시행하였다. 연구 결과 전체 환자 중 DJD군에 속한 환자는 31.7%였고, non-DJD군에 속하는 환자는 68.3%였다. DJD군은 성별에 따라 다른 분포를 보여 남자보다 여자의 이환율이 높았고, 10대와 20대에서 가장 높은 분포를 보였다. 환자의 내원 주소 중에서는 전치부 개방교합, 턱의 후퇴감, 안모 비대칭, 개구장애를 주소로 내원한 환자가 다른 주소로 내원한 환자들에 비해 DJD를 보일 위험성이 높았으며, 교정치료 경력이나 중심위-중심교합위 변위 그리고 염발음을 보이는 환자도 DJD군에 속할 위험성이 큰 것으로 나타났다. 따라서 측두하악장애를 가진 환자 중 30세 이하의 여성이 위와 같은 임상적 특징을 보이는 경우, 교정치료를 계획할 때 DJD에 이환 되었을 가능성에 대하여 충분히 주의를 기울여야 할 것으로 생각된다. (대치교정지 2006;36(6):402-11) Objective: This study was carried out to evaluate the distribution and clinical features of patients with degenerative change of the mandibular condyle. Methods: Six thousand and seventy patients with TMD (temporomandibular disorder) were selected for this study, who had complete initial clinical records and radiographs. Panorama and TMJ panorama radiographs were used to screen the degenerative change in the condyle, and the patients were divided into DJD (degenerative joint disease) and non-DJD groups. Results: The distribution and clinical features of the two groups were compared. Out of the total number of patients, 31.7% were in the DJD group, and 68.3% were in the non-DJD group. The portion of females was larger in the DJD group (80.8%) than in the non-DJD group (67.5%), and the DJD group had high prevalence in the second and third decades. Lack of incisal contact, retrusive chin, facial asymmetry, and mouth opening limitation were the chief complaints of the patients who had positive relation to DJD. Conclusion: Patients with an orthodontic treatment history, CO-CR discrepancy and crepitation were at possible risk of having DJD. (Korean J Orthod 2006;36(6):402-11)

백화사설초의 외부형태와 내부조직의 형태학적 관찰

임웅규,권규찬,사동민 서울大學校 農業生命科學大學 農業開發硏究所 1995 서울대농학연구지 Vol.20 No.1

유럽의 웨딩플라워에 대한 역사적 고찰

임수연,이규민 한국화훼연구회 2001 화훼연구 Vol.9 No.2

Flower design has been developed into various way through the ages. Particularly it has been greatly influenced by fashion, social background and so on. According to ancient description, people used flowers far the purpose of medical care or religious things first time and gradually people used flowers as a fragrance and a decoration for women's costumes. There were corsages, headdress, trimming of dresses and various ways to use flowers. And then these things were getting biger and more elaborate, women started to carry bunches of flowers on the wedding scenes which was one of the happiest moment in a life.

알코올사용장애의 유형별 특징

임명호,백기청,이경규,홍성도,김현우,이민규 大韓神經精神醫學會 1997 신경정신의학 Vol.36 No.5

대체적으로 알코올성 장애는 이질적인 집단으로 이해되어지고 있으며, 이는 알코올성 장애의 예후와 치료가 유형에 따라 다르다고 보기 때문이다. 이러한 알코올성 장애는 음주 형태, 의존유형, 유전적 취약성(genetic vulnerability), 성격유형, 정신병리적 측면에 따라 여러 유형으로 나눌 수 있다. 본 논문은 Babor등(1992)이 분류한 A형, B형의 아형분류가 우리나라에서도 이용가능한 지를 알아보는 예비적 조사논문으로써 알코올리즘의 진단 및 이해를 기하고자 하였다. 만 18세 이상부터 만 65세 이하의 알코올중독 남자 환자 94명을 대상으로 15개의 변인에 따라 군집분석을 시행하였으며, A형과 B형의 두 아형군 및 정상대조군과의 인구학적 특성, 임상양태의 차이를 비교하였다. 결과는 다음과 같다. 1) A형, B형, 그리고 정상대조군간의 연령, 학력, 결혼상태, 종교 등의 인구학적 특성의 차이는 없었다. 2) B형은 음주시작연령, 과다한 음주를 시작한 연령, 문제를 일으킨 연령에서 A형에 비해 세 항목 모두에서 일찍 발현하는 것으로 나타났다. 또한 B형에서 A형보다 의존 정도가 더 심하며, 평균음주량 및 가장 많이 과음한 양에 있어서도 A형보다 많이 마시는 것으로 나타났다. 3) A형보다 B형에서 좀 더 1차가족 중에 알코올로 인한 문제가 있는 사람이 많이 있는 것으로 나타났다. 4) B형은 A형보다 소아청소년기에 있어서 좀 더 많은 행동문제가 있음을 나타냈다. 5) 내과적 합병증, 신체생리적 후유증 및 사회적 후유증 및 생활사 후유증 또한 B형에서 좀 더 심한 분포를 보이고 있었다. 6) 정신병리요소에서 B형은 우울, 불안, 적대감에 있어서 A형보다 모두 유의하게 심한 증상을 보였다. 7) A형, B형, 정상대조군의 세 군간에서 모두 유의한 차이를 보이는 신뢰성있는 척도는 음주일수, 의존정도척도, 생활사정도 척도, 내과적 합병증, 사회적 후유증등이었다. 8) 음주 사용척도는 두 아형군과 정상대조군을 구분하는데 매우 신뢰성이 있는 척도로 나타났다. 상기의 결과를 종합해보면, 알코올사용장애에 대하여 Babor등(1992)이 분류한 A형, B형의 아형분류는 우리나라에서도 비슷한 양상을 보였으며, 이의 적용은 향후 알코올사용장애의 진단 및 이해에 이용가능할 것으로 평가한다. Objective : Multiple typologies of alcoholics have been studied, such as Jellineck's disease concept classification, Cloninger's neurobiological learning model, Zucker's developmental model, DSM Ⅲ-R and DSM Ⅳ classification, and Babor's multidimensional typology. To study if Babor's typology modification could be used to classify Korean alcoholics, we grouped 95 male inpatient alcoholics into Babor's typology modification. Methods : This study employed cluster analysis of measures representing several dimensions : premorbid risk and vulnerability dependence severity and alcohol-related problems, chronicity and alcohol-related consequences, and comorbid psychopathology. We compared demographic and clinical characteristics among Babor's type A and type B alcoholics and normal control group. Results : Type B alcoholics showed more characteristic symptoms in family history, more childhood behavior problems, earlier onset, more drinking amount, and more dependence severity, more medical, social, physical problems, more life time severity, more depressive, anxiety, hostility, compared with type A alcoholics. The statistically significant variables differentiating three groups(type A, type B, normal control group) were drinking days, dependence severity, lifetime severity, medical, social consequence. Alcohol Use Inventory to Babor's typology of alcoholism was very useful scale differentiating three groups. Conclusion : Babor's typology of alcoholism was useful for classification of inpatient alcoholics of Korea. It can be helpful and applicable to clinical diagnosis and research in Korean alcoholic patients.

극저사이클 하중을 받는 구상흑연주철의 초기균열성장에 관한 연구

김민건,임복규,김동열 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

In this study, extremely low cycle fatigue tests were carried out under push-pull loading conditions using graphite cast iron (GCD). In order to clarify the fatigue fracture mechanism of GCD in an extremely low cycle fatigue regime successive observations of internal fatigue damage were performed. The results obtained are as follows. (1) The process of extremely low cycle fatigue can be classified into three stages which are composed of the generation, growth and coalescence of microvoids inside materials. (2) In an extremely low cycle fatigue regime, microvoids originate from debonding of graphite-matrix interface.