• 제목/요약/키워드: shock reaction

검색결과 259건 처리시간 0.021초

Ignition Delay Times in $C_2H_2-O_2$-Ar Mixture behind a Reflected Shock Wave

  • 류지철;서희;강준길;오규형
    • Bulletin of the Korean Chemical Society
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    • 제18권10호
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    • pp.1071-1075
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    • 1997
  • Detonation characteristics of acetylene were studied behind reflected shock waves in the temperature range 800-1350 K by monitoring OH emission and pressure profiles. For a comprehensive measurement of ignition delay time, the mixture composition was varied in a wide range of Ar mole % was varied from 0.625 to 2.5 in stoichiometric ratio of C2H2-O2-Ar. A computer simulation study was also performed to elucidate the important elementary steps determining ignition behavior. The 33-reaction mechanism provides a good agreement in delay time between the observed and the calculated ones.

예조건화기법을 이용한 유동장 및 반응유동장의 계산 (Computation of Non-reacting and Reacting Flow-Fields Using a Preconditioning Method)

  • 고현;윤웅섭
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2001년도 춘계 학술대회논문집
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    • pp.189-194
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    • 2001
  • In this paper, non-reacting and reacting flowfields were computed using a preconditioned Navier-Stokes solver. The preconditioning technique of Merkle et al. and TVD scheme or Chakravarthy and Osher was employed and the results obtained using developed code have a good agreement with the previous results and experimental data. The preconditioned Wavier-Stokes equation set with low Reynolds number $\kappa-\epsilon$ equation and species continuity equations, are discretized with strongly implicit manner and time integrated with LU-SSOR scheme. For the purpose of treating unsteady problem the duel-time stepping scheme was employed. For the validation of the code in incompressible flow regime, steady driven square cavity flow was considered and calculation result shows reasonably good agreement with the result of incompressible code. Shock wave/boundary layer interaction problem was considered to show the shock capturing performance of preconditioned-TVD scheme. To validate unsteady flow, acoustic oscillation problem was calculated, and supersonic premix flame of $H_2$-air reaction problem which is calculated with turbulence model, 9-species/18-reaction step reaction model, shows reasonable agreement with the previous results. As a result, the preconditioning method has an advantage to calculate incompressible and compressible flow through one code and preconditioned solver easily developed from standard compressible code with minor efforts. But additional computational time and computer memory is required due to preconditioning matrix.

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메틸 라디칼과 산소 분자 반응에 관한 충격관 연구 (Shock Tube Study on the Reaction of Methyl Radical with Molecular Oxygen)

  • 신권수
    • 대한화학회지
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    • 제39권10호
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    • pp.769-775
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    • 1995
  • 메틸 라디칼과 산소 분자 사이의 반응 속도를 입사 충격파를 이용하여 1390부터 2250k 온도범위 및 1.5에서 5.3mol/$m^3$ 밀도 범위에서 213.9nm 파장에서의 메틸 라디칼의 흡수 스펙트럼을 측정하여 고찰하였다. 메틸 라디칼을 생성하기 위한 원천 분자로는 azomethane이 사용되었다. 실험 결과 $CH_3 + O_2{\rightarrow}CH_2O + OH$ 반응의 속도상수는 $k_2=1.35{\times}10^{12}\;exp( - 5900 K/T)\;cm^3 mol^{-1}s^{-1}$ 같이 표현할 수 있었다.

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서민주거안정정책이 주택가격에 미치는 영향에 관한 연구 (Study on the Price of Housing depending on the Ordinary housing stability policy)

  • 고필송;고봉성
    • 한국전자통신학회논문지
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    • 제6권2호
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    • pp.280-287
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    • 2011
  • 연구의 목적은 서민주거안정정책이 주택가격에 미치는 영향을 분석하는 것이다. 이에 대한 실증분석을 실시한 결과 다음과 같은 결론을 얻었다. 첫째, 그랜저인과관계를 검증한 결과 전 지역의 주택시장은 서민주거안정정책에 영향을 주고 있는 것으로 나타났다. 둘째, 충격반응은 전 지역에서 부(-)의 반응을 보이며, 서민주거안정정책은 주택시장안정에 어느 정도 기여한 것으로 나타났다. 셋째, 로짓회귀분석결과 서민주거안정정책은 노무현 정부의 강남지역을 제외하고 주택시장안정에 상당한 효과가 있는 것으로 나타났다.

Anaphylactic Shock Caused by the Epidurally-Administered Hyalurinidase

  • Lee, Hae-Kwang;Choi, Eun-Joo;Lee, Pyung-Bok;Nahm, Francis Sahngun
    • The Korean Journal of Pain
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    • 제24권4호
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    • pp.221-225
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    • 2011
  • Hyaluronidase is an enzyme that has temporary and reversible enzymatic effects on the matrix of connective tissue. When added to local anesthetics in pain treatments, it enhances their infiltration and dispersal into tissues. It is widely used in anesthesia for ocular, dental, and plastic surgery. Reports of drug hypersensitivity to hyaluronidase are rare and are usually confined to peribulbar or retrobulbar anesthesia during ophthalmic surgery. However, few reports exist on adverse drug reaction after epidural injection. We have observed two patients experiencing anaphylactic shock caused by hyaluronidase following epidural injection. Most of the patients with a hypersensitivity to hyaluronidase had one previous uneventful injection containing hyaluronidase, implying that sensitization had taken place. However, hypersensitivity occurring at the first administration is possible. A positive skin test can help establish the diagnosis. Although rare, the possibility of an allergic reaction to hyaluronidase should be considered even in patients with no known previous exposure.

스포츠 에어로빅스 팔착지 동작의 지면 반력 분석 (Analysis of the Ground Reaction Force of Arm Landing during Sports Aerobics)

  • 유실
    • 한국운동역학회지
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    • 제12권1호
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    • pp.115-124
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    • 2002
  • The purpose of this study is to analyze the ground reaction force of arm landing on arm and leg during sports aerobics. Subjects of this study were total 10 players of 5 males and 5 females who have are domain sports aerobics medalists more than the third place in national tournaments. The subjects jumped between the two ground reaction force analyzers, while landing their right hand on the front platform(#1) and their right leg on the rear platform(#2), and the data frequency was set to 200Hz. Findings of this study are as follows; More than 3 times of impact peak force of vertical reaction force acted on arm joint than on leg joint. And, when ground reaction force on foot increased, ground reaction force on hand decreased. 3 impact peaks of curve of ground reaction force were found - Impact Peak 1 incurred on the time the palm lands on the ground, Impact Peak 2 absorbing shock secondarily on wrist joint, and Active Peak incurred on the time of holding the weight while pushing out the severly bent elbow joint.

항장요법(肛腸療法)에 의한 소시호탕(小柴胡湯)의 아나필락시 쇼크 억제(抑制)에 대한 실험적(實驗的) 연구(硏究) (Experimental Study of Inhibitory Effect on Anaphylactic Shock of Sosihotang by Anal Therapy)

  • 강태희;문석재;문구;원진희;김형민
    • 대한한의학회지
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    • 제19권2호
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    • pp.439-449
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    • 1998
  • Anal Therapy is another way of taking medicine. It is a traditional pathway but not available in common situation. Nevertheless, It has many benifect and usefulness, it has not treated so much. Through Anal Therapy, the valid compound of Herb med can be reach to the desination in theory of the organism and loca1 medical action. The former is called Jung-Chei Theory(整體論), which is the one of the most important basements in building traditional Korean medicine. As there are many kinds of Anal therapy, this study use reservation type. Sosihotang(SSHT) is one of the well-known korean medicines for a long time. It is used for the treatment of such dieases as infectious diseases, hepatic diseases and gastroenteritis and so on. In this study, the author investigated the effect of an aqueous extract of SSHT by Anal therapy(Reservative Enema) in anaphylactic shock. The following results were obtained 1. SSHT inhibited anaphylactic shock 100% with a dose of 1.0 g/kg 1 hr before intraperitoneal injection of compound 48/80. SSHT significantly reduced serum histamine contents induced by compound 48/80. 2. SSHT (0.1 g/kg) also inhibited to 30.9% (P<0.05)) local cutaneous anaphylactic reaction activated by anti-dinitrophenyl (DNP) IgE. 3. The validity rate of reservative enema is as much as oral pathway. 4. In addition, SSHT dose-dependently inhibited the histamine release from the peritoneal mast cells by compound 48/80 or anti-DNP IgE. These results provide evidence that Anal Therapy(Reservative enema) of SSHT may be beneficial in the treatment of systemic and local anaphylactic reaction. Moreover, I wish another much sincere study of Anal Therapy (Reservative enema) would be obtained.

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Statistical Parametric Mapping을 이용한 시상면에서의 양발 착지와 외발 착지의 전략 차이 (Analysis of the Differences of the Shock Attenuation Strategy between Double-leg and Single-leg Landing on Sagittal Plane using Statistical Parametric Mapping)

  • Ha, Sunghe;Park, Sang-Kyoon;Lee, Sae Yong
    • 한국운동역학회지
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    • 제29권4호
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    • pp.255-261
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    • 2019
  • Objective: The purpose of this study was to investigate differences of shock attenuation strategies between double-leg and single-leg landing on sagittal plane using statistical parametric mapping. Method: Nine healthy female professional soccer players (age: 24.0±2.5 yrs, height: 164.9±3.3 cm, weight: 55.7±6.6 kg, career: 11.2±1.4 yrs) were participated in this study. The subjects performed 10 times of double-leg and single-leg landing from the box of 30 cm height onto force plates respectively. The ground reaction force, angle, moment, angular velocity, and power of the ankle, knee, and hip joint on sagittal plane was calculated from initial contact to maximum knee flexion during landing phase. Statistical parametric mapping was used to compare the biomechanical variables of double-leg and single-leg landing of the dominant leg throughout the landing phase. Each mean difference of variables was analyzed using a paired t-test and alpha level was set to 0.05. Results: For the biomechanical variables, significantly increased vertical ground reaction force, plantarflexion moment of the ankle joint, negative ankle joint power and extension moment of the hip joint were found in single-leg landing compared to double-leg landing (p<.05). In addition, the flexion angle and angular velocity of the knee and hip joint in double-leg landing were observed significantly greater than single-leg landing, respectively (p<.05). Conclusion: These findings suggested that negative joint power and plantarflexion moment of the ankle joint can contribute to shock absorption during single-leg landing and may be the factors for preventing the musculoskeletal injuries of the lower extremity by an external force.

사백산(瀉白散)이 Compound 48/80에 의하여 유도(誘導)된 Anaphylatic shock와 피하반응(皮下反應)에 미치는 영향(影響) (Effects of Sabaiksan on the Compound 48/80 Induced Anaphylatic Shock and Cutaneous Reaction)

  • 김민호;한상환;전병득
    • 대한한방내과학회지
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    • 제11권2호
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    • pp.22-42
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    • 1990
  • Sabaiksan has been prescribed to treat various allergic diseases in herbal medicine which were induced by various vasoactive amine released from the mast cells. The constituents of Sabaiksan are Mori Cortex Radices(MCR), Lycii Cortex Radicis(LCR) and Glycyrrhizae Radix(GR). Recently, simple models of compound 48/80 induced anaphylactic shock and cutaneous reaction in vivo were developed to test various agents employed in the field of allergy and toxicology research. The purpose of this study is to evaluate the effects of Sabaiksan on compound 48/80 induced anaphylactic stock, cutaneous reaction and mesenteric mast cell degranulation rate in ICR mice, and on compound 48/80 induced peritoneal mast cell degranulation and histamine release in vitro. Groups of ICR mice were intraperitoneally pretreated with $100{\mu}{\ell}$ of saline, $MCR(2g/m{\ell}),\;LCR(2g/m{\ell}),\;GR(g/m{\ell})$ or Sabaiksan itself(MCR+LCR+GR) at 24, 12 and 1 hour before compound 48/80 solution ($10{\mu}{\ell}/gm$ B. W) were peritoneally given into them, and then mortality within 72 hours after the compound 48/80 injection, and mesenteric mast cell degranulation rate at 15 minutes after compound 48/80 injection were calculated. In vitro experiment, $400{\mu}{\ell}$ of rat peritoneal mast cell suspension$(10^6cell/m{\ell})$ were pretreated with $50{\mu}{\ell}$ of saline, $MCR(2g/m{\ell}),\;LCR(2g/m{\ell}),\;GR(g/m{\ell})$ or Sabaiksan itself at room temperature for 30 minutes, and then $50{\mu}{\ell}$ of compound 48/80 solution $(100{\mu}g/m{\ell})$ were added into it. 30 minutes after the addition of compound 48/80 solution, histamine release assay in the supernatant of peritoneal mast cell suspension were performed employing radioisotope enzymatic assay and morphologic changes of mast cells in each regular time point were photographed. Compared with controls, compound 48/80 induced anaphylactic shock was significantly inhibited by MCR and GR pretreatment into the ICR mice. Significant inhibition of compound 48/80 induced cutaneous reaction, mesenteric mast cell degranulation rate in vivo and histamine release from the rat peritoneal mast cells in vitro was observed only in MCR pretreated group. From the above results, it is suggested that MCR component of Sabaiksan may playa key role to suppress mast cell function since it has been applied to various allergic diseases.

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