• Journal of the Korea Safety Management & Science
• /
• v.11 no.1
• /
• pp.43-49
• /
• 2009

This study set three kinds of situation and observed the various states such as carbonization by experimenting damages by fire of electric iron. The results of this study are as follows: The fire did not occurred when the unpowered iron over mattress and cotton shirts was com busted completely by external flame because the temperature of surface of soleplate and mattress did not reach the minimum ignition energy and when the powered electric iron over mattress and cotton shirts was left for an hour with its temperature dial set to high because the temperature of combustibles did not reach the minimum ignition energy. The fire occurred when the electric iron in which the outer box, bi-metal switch, and temperature fuse were removed over mattress and cotton shirts was powered by through heater terminal, and then the electric iron, mattress, and cotton shirts were combusted by the fallen combustibles because the temperature of combustibles reached to the minimum ignition energy with the help of active transfer of heat.

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.6
• /
• pp.635-641
• /
• 2018

To select the operating condition of 0.5 MWth chemical looping combustion system, minimum fluidization velocity, transition velocity to fast fluidization and solid circulation rate were measured using mass produced new oxygen carrier (N016-R4) which produced by spray drying method for 0.5 MWth chemical looping combustion system. A minimum fluidization velocity decreased as the pressure increased. The measured transition velocity to fast fluidization was 2.0 m/s at ambient temperature and pressure. The measured solid circulation rate increased as the solid control valve opening increased. We could control the solid circulation rate from 26 to $93kg/m^2s$. Based on the measured minimum fluidization velocity and transition velocity to fast fluidization, we choose appropriate operating conditions and demonstrated continuous solid circulation at high pressure condition (5 bar-abs) up to 24 hours.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.136.2-136.2
• /
• 2011

In this work, we analyzed correlations between life-cycle greenhouse gas (GHG) emissions and life-cycle cost of energy resources. Energy resources studied in this paper include coal, natural gas, nuclear power, hydropower, geothermal energy, wind power, solar thermal energy, and solar photovoltaic energy, and all of them are used to generate electricity. We calculated the mean values, ranges of maximum minus minimum values, and ranges of 90% confidence interval of life-cycle GHG emissions and life-cycle cost of each energy resource. Based on the values, we plotted them in two dimensional graphs to analyze a relationship and characteristics between GHG emissions and cost. Besides, to analyze the technical maturity, the GHG emissions and the range of minimum and maximum values were compared to each other. For the electric generation, energy resources are largely inverse proportional to the GHG emission and the corresponding cost.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.05a
• /
• pp.303-308
• /
• 2003

가연성 물질의 최소점화에너지(Minimum Ignition Energy; MIE)를 아는 것은 화학공정 등의 안전성 평가에 중요한 것이다. 현재 MIE의 측정에는 주로 용량성 불꽃방전이 이용되고 있다. 용량이 큰 커패시터를 이용한 방전에서는 MIE가 크게 되는 경향이 있고, MIE가 회로정수에 의존한다는 것이 실험적으로 알려져 있다. 이 현상은 방전회로의 시정수와 점화를 위한 에너지의 수송시간과의 관계에 의해 이론적으로 설명하는 것이 가능하게 되었다.(중략)

• Bulletin of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.155-157
• /
• 1992

Extensive search over the energy surface of bicyclo[4.2.2]decapentaene with MMP2 molecular mechanics method and AM1 semiempirical MO method revealed only one, deep energy minimum structure, which corresponds to 1. The alternative structure 2 could not be identified as a stationary point. Although the deviation of benzenoid ring from planarity is large in the energy minimum structure (${\phi} = 26^{\circ}$(MMP2), $37^{circ}$ (AM1)), the bond lengths show no severe alternation.

• Journal of the Korean Solar Energy Society
• /
• v.24 no.3
• /
• pp.73-83
• /
• 2004

The purpose of this study is to select the optimal transmittance rate of windows in office buildings through subjective evaluation and energy performance analysis(computer simulation program ; DOE 2.1E). The results are as follows ; 1) In the subjective evaluation experiment, minimum transmittance of the glass is GE 30% and LT 70%, but the optimal transmittance rate is concluded in $40%\sim60%$. 2) As a result of the energy performance analysis, it is desirable for the building of consumptive with mainly air-conditioning to make transmittance as 40-60%. 3) Comparing foreign study on minimum and optimal transmittance rate is $25%\sim38%$, the minimum transmittance of this study is almost the same. But for the optimal transmittance rate, 20% more is needed for KOREAN.

• Journal of The Korean Astronomical Society
• /
• v.37 no.5
• /
• pp.509-515
• /
• 2004

We present results from an extensive synthetic observation analysis of numerically-simulated radio galaxy (RG) jets. This analysis is based on the first three-dimensional simulations to treat cosmic ray acceleration and transport self-consistently within a magnetohydrodynamical calculation. We use standard observational techniques to calculate both minimum-energy and inverse-Compton field values for our simulated objects. The latter technique provides meaningful information about the field. Minimum-energy calculations retrieve reasonable field estimates in regions physically close to the minimum-energy partitioning, though the technique is highly susceptible to deviations from the underlying assumptions. We also study the reliability of published rotation measure analysis techniques. We find that gradient alignment statistics accurately reflect the physical situation, and can uncover otherwise hidden information about the source. Furthermore, correlations between rotation measure (RM) and position angle (PA) can be significant even when the RM is completely dominated by an external cluster medium.

• Fire Science and Engineering
• /
• v.10 no.1
• /
• pp.3-9
• /
• 1996

Electrostatic charge is generated in large scale or high speed processes dealing with materials with large resistance, or under complicated condition. Fire and explosion often occur due to electrostatic charge accumulated in flammable gases, vapor, liquids and powder. It is usually very difficult to verify the cause of accidents as well as the prevention. In this study, it is shown that the needle electrode needs the electrode gap from 1.8mm to 3.8mm, sphere electrode and plate electrodes need the electrode gap of 1.9mmfor the minimum ignition energy. The sphere electrode and the plate electrode requires 12.8mJ and 3.2mJ of minimum ignition energy respectively with the electrode gap of 1.1mm. The ignition voltage rises to very large value as the ground resistance increases.

• Fire Science and Engineering
• /
• v.11 no.2
• /
• pp.3-10
• /
• 1997

Attempts are being made to investigate temperatures dependence of minimum ignition energy (MIE) based on concept of quantity of heat and thermal ignition theory. Regression equations for predicting MIE by means of temperature variations on the basis of statistical and mathematical methods are proposed. This study is undertaken to learn what proposed method is satisfactory hydrocarbons(propane and pentane). The proposed method has been tested and compared sucessfully with previously reported data in various journal.

• Journal of the Korean Institute of Gas
• /
• v.2 no.2
• /
• pp.55-60
• /
• 1998

In this study, we investigated the dust explosion characteristics by determining minimum ignition energy and explosion limit for this experiment, we used pine-tree dust which was used widely for the filler of thermosetting resin. The experiment was accomplished according to the variation of discharge gap, dust concentration, particle size and humidity. The result of this experiment are as follows; (1) The relation between the discharge gap and ignition energy was that ignition energy decreased according as the discharge gap became small, but increased when the discharge gap was below 4mm and suddenly became infinite when the discharge gap was below. So, we knew that this infinite value was limit discharge gap. (2) When the dust concentration increase and the particle size became microscopic it was easy to explore and in the same particle size, if the humidity increase the minimum ingnition energy decreased.