• Title/Summary/Keyword: Suppressant

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Effects of propane substitution for safety improvement of hydrogen-air flame (수소-공기 화염의 안전성 향상을 위한 프로판 첨가 효과)

  • Kwon, Oh-Chae
    • Transactions of the Korean hydrogen and new energy society
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    • v.15 no.1
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    • pp.12-22
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    • 2004
  • In order to evaluate the potential of partial hydrocarbon substitution to improve the safety of hydrogen use in general and the performance of internal combustion engines in particular, the outward propagation and development of surface cellular instability of spark-ignited spherical premixed flames of mixtures of hydrogen, hydrocarbon, and air were experimentally studied at NTP (normal temperature and pressure) condition in a constant-pressure combustion chamber. With propane being the substituent, the laminar burning velocities, the Markstein lengths, and the propensity of cell formation were experimentally determined, while the laminar burning velocities and the associated flame thicknesses were computed using a recent kinetic mechanism. Results show substantial reduction of laminar burning velocities with propane substitution, and support the potential of propane as a suppressant of both diffusional-thermal and hydrodynamic cellular instabilities in hydrogen-air flames.

The Influence of the BTA on Electrical Properties of Synthetic Fluids (합성절연유의 전기적 특성에 미치는 BTA의 영향)

  • Shin, Jong-Yeol;Shin, Hyun-Teak;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.2
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    • pp.162-166
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    • 1998
  • Synthetic fluid, class 7 group 2, as an insulating and cooling material is selected as. specimen, arid it is studied for the physical and electrical properties. Also, Benzotriazole(following as BT A) known as a suppressant of streaming electrification is added to it, and the change of physical and electrical properties by addition of BT A is investigated. From the spectrum of FT-IR, it is confirmed that the absorption peak in wavenumbers $3400{\sim}3450[cm^{-1}]$ is small or disappears when BTA is added. AC breakdown strength and volume resistivity of each specimen are investigated. It is considered that the effective content of BTA is about 10[ppm] for the suppression of electrification in this experiment.

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Dielectric Properties of Ultra-High Voltage Transformer Oils due to Streaming Electrification Suppressant (유동대전 억제제에 의한 초고압 변압기유의 유전 특성)

  • 이태훈;신종열;조경순;이용우;이수원;홍진웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.203-206
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    • 1998
  • In this paper, specimens stirred with the several kinds of benzotriazole(following as BTA) addition which is very effective to decrease the streaming electrification, are tested to investigate the change of properties for insulating fluid using in ultra-high voltage transformer, and it will give a guideline to find out a proper quantity of BTA addition for the most effective suppression against the streaming electrification. In GC, we could not find out the change of the physical properties in an insulating fluid by BTA. In a flowing transformer oil, the characteristics on dielectric of specimen contained BTA 10[ppm] are superior to the others.

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Electrical Conduction Properties of Synthetic Fluids (합성절연유의 전기전도특성)

  • 조경순;최봉철;이종필;이수원;신현택;홍진웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.294-297
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    • 1997
  • A study has been carried out electrical conduction properties of synthetic fluids No. 2 of KS class VII used for insulating and cooling the power device. BTA(Benzotrizole) as the streaming electrification suppressant additive is added to the oil, and the change of physical and electrical properties due to different BTA concentration is investgated. From the result of FTIR spectrum, it is confirmed that the absorpption peak in wavenumber 3400-3450[cm$\sub$-1/] is smaller and disappered by adding BTA to the oil. It is considered that the effective content of BTA is about 10[ppm] from the result of electrical conduction experiment.

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Herpetic Esophagitis in Immunocompetent Child

  • Altamimi, Eyad M.;Alorjani, Mohammed S.;Alquran, Wejdan Y
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.22 no.3
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    • pp.298-302
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    • 2019
  • A previously healthy 2.5-year-old male child presented with vomiting, diarrhea, and fever. During hospitalization he developed odynophagia and refusal to eat. His symptoms did not respond to acid suppressant therapy. He underwent upper endoscopy which showed severe inflammation, ulcerations and abundant necrosis. Histopathological features and serological testing were consistent with herpetic esophagitis. He had no history of recurrent infections or history of sick contacts. His immunological work up showed normal level of immunoglobulins and his White Blood Cells subpopulations were normal. His HSV serology was positive. The patient was started on acyclovir 5 mg/kg q 8 hours. He resolved his symptoms within 24 hours of treatment.

Phentermine and Phendimetrazine-Induced Psychotic Disorder and Bipolar Disorder: A Case Series (Phentermine 및 Phendimetrazine으로 유발된 정신병적 장애 및 양극성 장애 증례군 연구)

  • Kim, Soo Young;Kim, Tae-Suk;Kim, Dai-Jin;Chae, Jeong-Ho;Lee, Chang Uk;Joo, Soo Hyun
    • Korean Journal of Biological Psychiatry
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    • v.29 no.1
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    • pp.22-31
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    • 2022
  • Objectives Recently, weight loss has emerged as a national concern in South Korea, and this has resulted in an increase in the frequency of use of central nervous system (CNS)-stimulating appetite suppressants. This study aimed to collect cases of psychotic disorders and bipolar disorders triggered by phentermine and phendimetrazine and explore the clinical features and courses. Methods In this retrospective study, we analyzed the electronic medical records of patients and selected eight patients who developed psychotic symptoms and manic symptoms for the first time after taking phentermine and phendimetrazine. All cases were reviewed, and their clinical features and course were summarized. Results All eight patients developed psychotic symptoms, and one had accompanying manic symptoms. The final diagnosis was appetite-suppressant-induced psychotic disorder in four patients, schizophrenia in three, and appetite-suppressant-induced bipolar disorder in one. In addition, three patients were diagnosed as having substance-use disorder. The key psychotic symptoms of these patients were hallucinations and paranoia. Conclusions These case findings suggest that phentermine and phendimetrazine can cause psychotic disorder, bipolar disorder, or substance use disorder and that medical professionals and the public should practice caution when prescribing and using these drugs.

The changes of soil salinity in the Pinus densiflora forest after seawater spread using a fire-fight helicopter

  • Park, Jeong Soo;Koo, Kyu-Sang;Lee, Eun Ju
    • Journal of Ecology and Environment
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    • v.38 no.4
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    • pp.443-450
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    • 2015
  • The east coast of the Korean Peninsula is susceptible to fires because of the low rainfall in winter and spring, and large forest fires have occurred in this area. Lack of fresh water to combat fires has hampered efforts to prevent widespread forest fires in this region. Seawater has not been used as a suppressant because of possible detrimental effects of salt. We investigated the mobility of saline water in the forest soil and their effect on the microbial activity. Using a fire-fighting helicopter, seawater was sprayed over three plots (50 × 100 m) located on the eastern slope of the Baekdu mountain range in South Korea in April, 2011. We sampled the soil in April 4, May 20, and August 5 to determine the amount of salt that remained in the soil. The electrical conductivity value of the soil decreased to <400 μS/cm over a 1-month period. Approximately, four months after the application of seawater, the electrical conductivity value and Na+ content in all treatment plots did not significantly differ to those of the control plot, and total microbial activity also recovered to that of the control. Our results indicate that the amount of rainfall, soil physical-chemical properties, and topological factors may be a critical factor determining the mobility of saline water in forest soil.

Study on Perception of Weight Control and Patterns of Diet/Low-Calorie Food Consumption according to Weight Status in Adult Women (성인여성의 체중상태에 따른 체중조절인식과 다이어트 식품 구매·섭취행동에 관한 연구)

  • Han, Chae-Jeong
    • Journal of the East Asian Society of Dietary Life
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    • v.27 no.2
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    • pp.104-113
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    • 2017
  • The purpose of this study was to analyze and consumption patterns diet/low-calorie food. Ubjects were 353 adult women aged 20s~50s. Ubjects were divided into three groups according to body mass index (BMI): Normal group (BMI>23.0), overweight group (23.0${\leq}$BMI<25.0), and obesity group (BMI${\geq}$25.0). This study collected all information by self-administrated questionnaires. The SPSS version 21.0 was used for analysis of data. The obesity group lower education level (p<0.001), higher age (p<0.001) and higher income (p<0.001) than normal group. However, score of health status was highest in normal group (p<0.001). Proportion of obesity group pill type diet/low-calorie (p<0.034), drug (diuretic, appetite suppressant and riental medicine) (p<0.001), and cosmetic surgery (p<0.001). The main reason for consumption of diet/low-calorie was control without starving (28.0%). Obese group emphasized manufacturer, ingredient and reputation, whereas the normal group emphasized price and expected effectiveness (p<0.001).

A Technical Description on The Safety Aspects related To Gas Suppression Fire Protection System (가스계 소화시스템관련 안전기술)

  • 이창욱
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2002.05a
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    • pp.21-29
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    • 2002
  • With regard to the personnel safety and other safety when the gas suppressants are discharged into the area where occupants exist, the short term and long term effects to the health of people are discussed mainly with the Carbon dioxide agent and Halon Replacement agents system. To gain the benefits of CO2 extinguishing systems while minimizing risk to people serious attention must be given to personnel safety in the design, installation, and maintenance of CO2 systems. Training of personnel is essential. A major factor in the use of a clean agent fire suppressant in a normally occupied area is toxicity. While all halocarbon agents are tested for long-term health hazards, the primary endpoint is acute or short-term exposure, The primary acute toxicity effects of the halocarbon agents described here are anesthesia and cardiac sensitization. For inert gases, the primary physiological concern is reduced oxygen concentration.

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Anti-Obesity Drugs: A Current Research Insight

  • Son Eun-hwa;In San-Whan;Kim Byung-Oh;Pyo Suhkneung
    • Biomedical Science Letters
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    • v.11 no.2
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    • pp.89-101
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    • 2005
  • Obesity is increasing worldwide and has become a major health burden in Western societies affecting every third American and every fifth European. Obesity makes a major contribution to morbidity and mortality, predisposing individuals to cardiovascular disease and diabetes. Many new substances are currently being investigated for their usefulness in the pharmacotherapy of obesity. Most anti-obesity drugs can be divided into four groups: those that reduce food intake; those that alter metabolism; those that increase thermogenesis; and those that regulate hormone involved in feeding behavior. In this article we review these and other agents available in various countries for the treatment of obesity. Perhaps more importantly, we have focussed on areas of potential productivity in the future. Over the last 5 or so years, this impetus in obesity research has provided us with exciting new drugs targets involved in the regulation of feeding behavior and cellular mechanism involved in energy expenditure. Recent development in the quest for control of human obesity include the discovery of hormones, neuropeptides, receptors and transcription factors involved in feeding behavior, metabolic rate and adipocyte development. For developing new, perhaps even more specific pharmacological agents, further research is needed to understand the individual different genetic and physiological basis of obesity. It remains the hope of research scientists that in the not too distant future we shall see a new class of anti-obesity drugs arising logically from the molecular biology revolutions.

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