• Title/Summary/Keyword: spontaneous reaction

Search Result 166, Processing Time 0.027 seconds

The study on Coal Spontaneous Ignition Prevention using Safety Materials of Food and Cosmetics (식품과 화장품의 안전 소재를 이용한 석탄 자연발화 억제에 대한 연구)

  • Jun, Soo-Man;Kim, Young-Hee
    • Journal of the Korean Applied Science and Technology
    • /
    • v.39 no.2
    • /
    • pp.368-376
    • /
    • 2022
  • Spontaneous ignition occurs in industrial sites or anywhere in our lives, and is a phenomenon in which a substance ignites itself without an ignition source in the atmosphere. As the rate of chemical reaction increases, the heat generated increases, and the risk of spontaneous ignition increases. In this study, safe raw materials used for food and cosmetics were mixed to prepare coal spontaneous ignition prevention agents specifically among various spontaneous ignition phenomena. The effect of suppressing spontaneous combustion of coal was confirmed through lab and field tests with low-calorie, low-grade coal from Indonesia. As a result of the outdoor field test, the ignition prevention agent manufactured in this study compared with the control group(Fire after 90 days) showed excellent ignition inhibitors for more than 120 days. In addition, CO concentration control was confirmed by comparing the concentration of carbon monoxide for 50 days at the indoor coal yard. It was confirmed that the results were better than the comparative group coal and the existing anti-firing method. In addition, the possibility of coal fire prevention agents for indoor coal farms will be applied from 2024 was confirmed by studying the environment and safety of workers' working environments through official test such as soil and water quality test, MSDS of coal fire prevention agents in consideration of working workers, water quality, and eye irritation tests.

Current Status of Spontaneous Adverse Reactions Reporting System on Herbal Medicine in China, Japan, Korea and WHO (중국, 일본, 한국, WHO의 한약 자발적부작용보고체계 현황)

  • Woo, Yeon-Ju;Chung, Soo-Youn;Park, Byung-Joo
    • The Journal of Internal Korean Medicine
    • /
    • v.35 no.2
    • /
    • pp.111-118
    • /
    • 2014
  • Drugs may cause adverse effects, and spontaneous adverse drug reaction (ADR) reports have been used as the main method of drug safety evaluation after drugs have been released. The World Health Organization (WHO) collects ADR data reported from pharmacovigilance organizations in each nations. In China, pharmacovigilance centers operate with hierarchical structure at local, provincial and national levels. Also, Japan and Korea each operate their own respective independent pharmacovigilance organizations. WHO is collecting ADR reports for herbal medicine and 15~20% of all ADRs was related to herbal medicine in China. There are status reports of ADRs for herbal medicine in Japan as well. However, in Korea, there is no ADR reporting system regarding herbal medicine. In light of these overseas cases, a spontaneous ADR reporting system for herbal medicine in Korea should be necessary as well.

Characteristics of Spontaneous Combustion of Various Fuels for Coal-Fired Power Plant by Carbonization Rank

  • Kim, Jae-kwan;Park, Seok-un;Shin, Dong-ik
    • KEPCO Journal on Electric Power and Energy
    • /
    • v.5 no.2
    • /
    • pp.83-92
    • /
    • 2019
  • Spontaneous combustion propensity of various coals of carbonization grade as a pulverized fuel of coal-fired power plant has been tested from an initial temperature of $25^{\circ}C$ to $600^{\circ}C$ by heating in an oven with air to analyze the self-oxidation starting temperature. These tests produce CPT (Cross Point Temperature), IT (Ignition temperature), and CPS (Cross Point Slope) calculated as the slope of time taken for a rapid exothermic oxidation reaction at CPT base. CPS shows a carbonization rank dependence whereby wood pellet has the highest propensity to spontaneous combustion of $20.995^{\circ}C/min$. A sub-bituminous KIDECO coal shows a CPS value of $15.370^{\circ}C/min$, whereas pet coke has the highest carbonization rank at $2.950^{\circ}C/min$. The nature of this trend is most likely attributable to a concentration of volatile matter and oxygen functional groups of coal surface that governs the available component for oxidation, as well as surface area of fuel char, and constant pressure molar heat.

The Spontaneous Resorption of Herniated Lumbar Disc -A case report- (요추 추간판탈출증의 자연적 흡수 -증례 보고-)

  • Kim, Young Hoon;Moon, Dong Eon;Park, Chong Min;Yoon, Jae Won
    • The Korean Journal of Pain
    • /
    • v.18 no.1
    • /
    • pp.56-59
    • /
    • 2005
  • The most effective treatment methods for a herniated lumbar disc remain questionable. This report follows the patients course, from the onset of pain through the completion of the non-surgical treatment, and shows that a lumbar herniated disc, with radiculopathy, can be successfully treated with a non-surgical approach. This report discusses the possible explanations for disc resorption: retraction into the intervertebral space, dehydration/shrinkage and resorption due to an inflammatory reaction. A non-surgical approach can be an effective treatment option for a herniated lumbar disc.

Proposal of the Pharmacoepidemiologic Methodology Application to Research for Sasang Constitutional Pharmacology (약물역학연구 방법론의 체질약리연구 적용에 대한 제안)

  • Kim, Sang-Hyuk;Yoo, Jong-Hyang;Lee, Si-Woo
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.24 no.5
    • /
    • pp.753-757
    • /
    • 2010
  • The objectives of this paper is to propose the pharmacoepidemiologic methodology to Research for Sasang Constitutional Pharmacology. We mainly searched "Journal of Pharmacoepidemiology and Risk Management". And we also searched "J Korean Oriental Med.", "J of Sasang Constitutional Med.", "J. Oriental Physiology & Pathology", "Korean J Orient Int Med." using these kew words - "adverse event" or "side effect" and "Sasang Contitution" or "Constitution" or "Constitutional medicine". Through the examination of the Pharmacoepidemiologic methodology and current research for sasang constitiutional pharmacology, we could establish the proposal to collect objective constitutional medical reaction. For the actualization of this proposal, the more advanced studies will have to be carried out continuously.

The Investigation of Diesel Spray Combustion in DME HCCI Combustion (DME 예혼합 자기착화 연소중의 디젤분무연소에 관한 연구)

  • Lim, Ock-Taeck
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.32 no.4
    • /
    • pp.241-248
    • /
    • 2008
  • The purpose of the research is to investigate of diesel spray combustion for simultaneously reduction way of NOx and PM. The diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured, so we estimated it by CHEMKIN calculation. Two dimensional spontaneous luminescence images which are created by chemical species reaction at low temperature reaction (LTR) and high temperature reaction (HTR) are captured by using a framing streak camera. Also, combustion events were observed by high-speed direct photography. The ignition and combustion events were analyzed by pressure profiles and the KL values and flame temperatures were analyzed by the two-color method.

An Experimental Study on Expansion of Operation Range by Lean Boosting for a HCCI H2 Engine (희박과급에 의한 수소 예혼합 압축착화 기관의 운전영역 확장에 관한 실험적 연구)

  • Ahn, Byunghoh;Lee, Jonggoo;Lee, Jongmin;Lee, Jongtai
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.24 no.6
    • /
    • pp.573-579
    • /
    • 2013
  • Hydrogen engine with homogeneous charged compression ignition can achieve high efficiency by high compression ratio and rapid chemical reaction rates spatially. However, it needs to expansion of the operation range with over-all load conditions which is very narrow due to extremely high pressure rise rate. The adoption of the lean boosting in a HCCI $H_2$ engine is expected to be effective in expansion of operation range since minimum compression ratio for spontaneous ignition is decreased by low temperature combustion and increased surround in-cylinder pressure. In order to grasp its possibility by using lean boosting in the HCCI $H_2$ engine, compression ratio required for spontaneous ignition, expansion degree of the operation range and over-all engine performance are experimentally analyzed with the boosting pressure and supply energy. As the results, it is found that minimum compression ratio for spontaneous ignition is down to the compression ratio(${\varepsilon}$=19) of conventional diesel engine due to decreased self-ignition temperature, and operation range is extended to 170% in term of the equivalence ratio and 12 times in term of the supply energy than that of naturally aspirated type. Though indicated thermal efficiency is decreased by reduced compression ratio, it is over at least 46%.

Low-temperature Synthesis of (TiC+Al2O3) Reinforced Al Matrix Composite Based on Self-combustion Reaction (자발연소반응을 이용한 (TiC+Al2O3)/Al 복합재료의 저온합성)

  • Lee, Jung-Moo;Kim, Su-Hyeon;Cho, Young-Hee;Kim, Je-Woo;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.12
    • /
    • pp.1001-1004
    • /
    • 2011
  • The formation of TiC and $Al_2O_3$ particles based on the self-combustion reaction of the $Al-TiO_2-C-CuO$ system in an Al alloy melt was investigated. With an adequate amount of CuO in the system, a spontaneous reaction occurred within the Al alloy melt at $850^{\circ}C$ and thereafter was self-maintained, producing an Al matrix composite reinforced with thermodynamically stable TiC and $Al_2O_3$ particles. TiC and $Al_2O_3$ particles contributed to a considerable increase in the strength and stiffness, demonstrating the feasibility of this method as a practical application for structural parts.

The Study for the Single-based Propellant Shelf Life extension (단기추진제 저장수명 연장을 위한 방안 연구)

  • Bong, Ha-Gyu;Yoon, Keun-Sig
    • Journal of Applied Reliability
    • /
    • v.5 no.3
    • /
    • pp.357-371
    • /
    • 2005
  • Nitrogen oxide gases which were produced by spontaneous reaction of nitrocellulose (NC) in the single base propellant accelerate the decomposition of propellant, and result in the reduction of shelf life, The amount of nitrogen oxide was reduced by the addition of $0.3wt\%$ CaCO3 to conventional stabilizer(DPA) which extended the shelf life of the single base propellant as much as twice compared with commercial propellant.

  • PDF

Histopathological Observation of Spontaneous Pulmonary Keratinizing Cyst in Sprague-Dawley Rat (Sprague-Dawley 랫트에 자연발생한 Pulmonary Keratinizing Cyst의 병리조직학적 관찰)

  • 손화영
    • Korean Journal of Veterinary Pathology
    • /
    • v.1 no.2
    • /
    • pp.135-138
    • /
    • 1997
  • A pulmonary keratinizing cyst was found incidentally in a 30-week-old female Sprague-Dawley rat. The cyst was lobe of the lung, lined by stratified squamous epithelium and filled with concentric layers of desquamated keratin. The wall consisted of 2-4 layers of well differenciated squamous cells. The adjacent lung tissues were slightly compressed but not otherwise damaged by the cyst. There was no inflammatory reaction or mitotic figures observed in the cyst.

  • PDF