• 제목/요약/키워드: Spontaneous increase

검색결과 287건 처리시간 0.026초

활성탄의 자연발화에 있어서 발화유도시간과 온도분포에 관한 연구 (A Study on the Ignition Induction Time and Temperature Distribution at Spontaneous Ignition of Activated Carbon)

  • 최재욱;김상렬;이상록;최광재
    • 한국안전학회지
    • /
    • 제8권3호
    • /
    • pp.44-49
    • /
    • 1993
  • The spontaneous ignition induction time and temperature distribution were observed by performing experiments for granulated activated carbon. As the results of the experiments at the same amplitude, the critical spontaneous ignition temperature was decreased with increase of the time period, while, the ignition induction time was increased with the increase of the time period. The critical spontaneous ignition temperature was decreased with the increase of the amplitude for the shorter period. The temperature distribution of the sample showed the highest around ignition-point at center of the vessel and after ignition the highest temperature was moved toward surface of the vessel.

  • PDF

Roles of Nitric Oxide in Vestibular Compensation

  • Jeong, Han-Seong;Jun, Jae-Yeoul;Park, Jong-Seong
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제7권2호
    • /
    • pp.73-77
    • /
    • 2003
  • The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy (UL) were studied. Sprague-Dawley male rats, treated with nitric oxide liberating agent sodium nitroprusside (SNP) and NOS inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME), were subjected to destruction of the unilateral vestibular apparatus, and then spontaneous nystagmus was observed in the rat. To explore the effects of nitric oxide on the neuronal excitability, whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus in SNP treated rats was lesser than that of spontaneous nystagmus in control animals. In contrast, pre-UL treatment with L-NAME resulted in a significant increase in spontaneous nystagmus frequency. In addition, SNP increased the frequency of spontaneous action potential in isolated medial vestibular nuclear neurons. Potassium currents of the vestibular nuclear neurons were inhibited by SNP. After blockade of calcium dependent potassium currents by high EGTA (11 mM) in a pipette solution, SNP did not inhibit outward potassium currents. 1H-[1,2,4] oxadiazolo [4,3-a] quinozalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, inhibited the effects of SNP on the spontaneous firing and the potassium current. These results suggest that nitric oxide after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cGMP, and consequently would increase excitability in ipsilateral vestibular nuclear neurons.

쌀과자의 자연발화 특성에 관한 연구 (A Study on the Characteristics of Spontaneous Ignition for Rice Cracker)

  • 김홍;강영구
    • 한국안전학회지
    • /
    • 제10권4호
    • /
    • pp.75-80
    • /
    • 1995
  • Spontaneous ignition characteristics of rice cracker were observed by preforming experiments at constant ambient temperature. As the results of the experiments, the critical spontaneous ignition temperature were exponentially decreased with the increase of ambient temperature. Type of combustion of rice cracker are smouldering combustion at low ignition temperature and flame combustion at high temperature. The rice cracker containing pam oil showed lower spontaneous ignition temperature than pure rice cracker because of oxidation heat of pam oil.

  • PDF

불임 환자와 반복자연유산 환자에서 황체형성호르몬에 대한 연구 (A Study of Luteinizing Hormone in Patients with Infertility and Recurrent Spontaneous Abortion)

  • 남윤성;조용선;이우식;김남근;김세현;차광렬
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제29권2호
    • /
    • pp.91-96
    • /
    • 2002
  • Objective : To evaluate luteinizing hormone (LH) in patients with infertility and recurrent spontaneous abortion. Material and Method: LH was tested by solid phase immunoradiometric assay based on monoclonal and polyclonal anti-LH antibodies. Results: Of 100 infertile patients, the number of less than 5 mIU/ml, 5$\sim$10 mIU/ml, greater than 10 mIU/ml in LH level was 67 (67%), 22 (22%), 11 (11%), respectively. Of 100 patients with recurrent spontaneous abortion, the number of less than 5 mIU/ml, 5$\sim$10 mIU/ml, greater than 10 mIU/ml in LH level was 79 (79%), 18 (18%), 3 (3%), respectively. There was a significant difference between patients with infertility and recurrent spontaneous abortion only in the group with LH level greater than 10 mIU/ml (p=.0325). Conclusions: High LH in the follicular phase is known to decrease pregnancy rate and increase abortion rate. But in this study the incidence of high LH in patients with recurrent spontaneous abortion was low. On the contrary, there was a significant increase of LH in infertile patients. So recurrent spontaneous abortion does not seem to be related to high LH level.

자발성 두개내 저압환자에서 경막외 혈액봉합술로 치험한 3예 (Three Cases of Spontaneous Intracranial Hypotension(SIH) Treated with Epidural Blood Patch)

  • 신진우;윤창섭;이청
    • The Korean Journal of Pain
    • /
    • 제10권1호
    • /
    • pp.104-108
    • /
    • 1997
  • Spontaneous intracranial hypotension, a syndrome of low CSF pressure, occurs without preceding events such as lumbar puncture, back trauma, operative procedure or medical illness. The most characteristic symptom is an occipital or frontal headache which is aggrevated in the erect position and relieved in the supine position. This syndrome usually resolves spontaneously or with strict bed rest. When the headach persists or is incapacitating, more aggressive treatment may be necessary. Autologous epidural blood patch is highly effective in the management of spontaneous intracranial hypotension. Epidural blood produces an organized clot which effectively tamponade any dural CSF leak. The rapid relief of headache immediately after the infusion of blood occur by some other mechanism, such as an increase in subarachnoid pressure that is known to occur with infusion of fluid into the lumbar epidural space. We report three cases of spontaneous intracranial hypotension successfully treated with epidural blood patch.

  • PDF

자연발화 음성 코퍼스에서 발화 속도에 대한 발화 길이의 영향 (The influence of utterance length on speech rate in spontaneous speech)

  • 김정선
    • 말소리와 음성과학
    • /
    • 제9권1호
    • /
    • pp.9-17
    • /
    • 2017
  • The current study examined speech rate and its variance in spontaneous Seoul Korean speech. The current study focused on factors affecting the variance of speech rate such as utterance length, individual speakers, and gender. The results revealed that, first, utterance length has a significant influence on speech rate. Longer utterances were spoken at a faster rate. Second, regarding the effect of utterance length, individual speakers differed significantly in their speaking rate. The variation between speakers and within speakers tended to increase as utterance length increases. Third, there were speakers' gender differences, indicating that males produced considerably faster speaking rate than females. Additionally, the current study implied that non-linguistic factors in spontaneous speech can affect the variance of speakers' speaking rate.

Spontaneous Pneumomediastinum: An Unusual Pulmonary Complication in Anorexia Nervosa

  • Lee, Kyung-Jin;Yum, Ho-Kee;Park, I-Nae
    • Tuberculosis and Respiratory Diseases
    • /
    • 제78권4호
    • /
    • pp.360-362
    • /
    • 2015
  • Spontaneous pneumomediastinum (PM) is an uncommon condition in which free air enters the mediastinum. This usually occurs either through esophageal tears after vigorous vomiting, or after alveolar rupture subsequent to a rapid increase in intra-alveolar pressure. Spontaneous PM is a rare entity in anorexia nervosa (AN) and self-induced vomiting is often the cause of PM in patients with AN. We experienced a case of spontaneous PM in an anorexic adolescent, in whom vomiting was not the cause of PM.

연속 파장 가변시 현상론적인 비선형 이득포화효과가 다전극 DBR 레이저의 잡음특성에 미치는 영향 (Phenomenological Nonlinear Gain Saturation Effect on the Noise Characteristics of a Multi-electrode DBR Laser with Continuous Frequency Tuning)

  • 이석목;최원준;한일기;김회종;우덕하;김선호;이정일;감광남;박홍이
    • 한국광학회지
    • /
    • 제6권2호
    • /
    • pp.135-141
    • /
    • 1995
  • 현상론적인 비선형 이득 포화 효과가 연속 파장 가변시 다전극 DBR 레이저의 잡음 특성에 미치는 영향을 이론적으로 연구하였다. 광전송선 모델에 종 방향으로의 자발적 방출 분포에 의한 향상계수 K와 비선형 이득 포화 효과를 고려하여 연속 파장 가변시 출력의 감소에 따른 상대적 세기 잡음과 주파수 잡음 특성을 분석하였다. 수동부분의 주입전류의 증가에 따라 자발적 방출률은 증가하며, 이에 비례하여 상대적 세기 잡음, 주파수 잡음 및 선폭은 증가한다. 현상론적인 비선형 이득 포화 효과는 상대적 세기 잡음 및 주파수 잡음 특성에 큰 영향을 주지만 선폭은 오히려 감소한다.

  • PDF

Cell thickness dependence of liquid crystal parameters

  • Sood, Nitin;Khosla, Samriti;Singh, Darshan;Bawa, S.S.
    • Journal of Information Display
    • /
    • 제13권1호
    • /
    • pp.31-36
    • /
    • 2012
  • Ferroelectric liquid crystal parameters, spontaneous polarization, and transition temperature were studied as a function of cell thickness. These parameters were found to increase with increasing cell thickness, but an exception was observed for the transition temperature in the case of a thin cell. A simple Landau model is presented to interpret the theoretical and experimental observations. The anomalous behavior is attributed to the electroclinic effect and is explained using the Landau model.