• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.10
• /
• pp.1081-1089
• /
• 2005

In order to examine the application feasibility of Orimulsion fuel in a commercial boiler using heavy fuel oil, a numerical and experimental research efforts have been made especially to figure out the fundamental combustion characteristics of this fuel in a small-scale boiler. One of the notable combustion features of Orimulsion fuel is the delayed appearance of flame location with the flame shape of rather broad distribution, which is found experimentally and confirmed by numerical calculation. This kind of flame characteristics is considered due to the high moisture content included inherently in the process of Orimulsion manufacture together with micro-explosion by the existence of fine water droplets. In order to investigate the effect on the combustion characteristics of Orimulsion, a series of parametric investigation have been made in terms of important design and operational variables such as injected amount of fuel, types of atomization fluid, and phonemenological radiation model employed in the calculation, etc. The delayed feature of peak flame can be alleviated by the adjustment of the flow rate of injected fuel and the generating features of CO, $SO_2$ and NO gases are also evaluated in the boiler. When the steam injection as atomizing fluid is used, the combustion process is stabilized with the reduced region of high flame temperature. In general, the calculation results are physically acceptable and consistent but some refinements of phenomenological models are necessary for the better resolution of pollutant formation. From the results of this small-scale Orimulsion boiler, it is believed that a number of useful information are obtained with the working computer program for the near future application of Orimulsion fuel to a conventional boiler.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.59 no.4
• /
• pp.462-466
• /
• 2010

The purpose of this study is to evaluate the safety of a wire connector fabricated for the effective installation of a lighting fixture including its contact resistance, insulation resistance, withstanding voltage characteristics, etc., and to provide the basis for the analysis and judgment of PL(Product Liability) dispute by presenting a damage pattern due to a general flame and overcurrent. This study applied the Korean Standard (KS) for the incombustibility test of the connector using a general flame and performed an overcurrent characteristics test of the connector using PCITS (Primary Current Injection Test System). The contact resistance of the housing connector was measured using a high resistance meter and the insulation resistance was measured using a multimeter. In addition, a supply voltage of AC 1,500V for testing the withstanding voltage characteristics was applied to both ends of the connector. Measurement was performed on 5 specimens and the measured values were used as a basis for judgment. Since the connector is fabricated in the form of a housing, it can be connected and separated easily and has a structure that allows no foreign material to enter. In addition, since it has a structure that allows wires to be connected only when their polarity is identical, any misconnection that may occur during installation can be prevented. When the incombustibility test was performed by applying a general flame to the connector, it showed outstanding incombustibility characteristics and the blade and blade holder connected to the housing remained firmly secured even after the insulation sheath (PVC) was completely destroyed by fire. In addition, the mechanism of the damaged connecting wire showed a comparatively uniform carbonization pattern and it was found that some residual melted insulation material was attached to both ends. In the accelerated life test (ALT) to which approximately 500% of the rated current was applied, the connector damage proceeded in the order of white smoke generation, wire separation, spark occurrence and carbonization. That is, it could be seen that the connector damaged by overcurrent lost its own metallic color with traces of discoloration and carbonization. The contact resistance of the connector at a normal state was 2.164mV/A on average. The contact resistance measured after the high temperature test was 3.258mV/A. In addition, the insulation resistance after the temperature test was completed was greater than $10G\Omega$ and the withstanding voltage test result showed that no insulation breakdown occurred to all specimens showing stable withstanding voltage and insulation resistance characteristics.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.1000-1009
• /
• 2005

This study is made to link lip the policy analysis theory flame and practice concerning the analysis of railroad tourism resources development policy and propose an alternative to feasibility for railroad tourism resources development policy in general. The specific objectives to achieve the purpose of this research are as follow; First. In consideration of railroad tourism resources development policy and theory of policy analysis idea and goals, for analysis of railroad tourism resources development policy analysis are to be instituted more systematically. Second, the theory of railroad tourism resources development policy analysis will be made more systematic and use it as basis of the said analysis for further.

• Analytical Science and Technology
• /
• v.21 no.6
• /
• pp.443-458
• /
• 2008

Brominated flame retardants (BFRs) are chemical compounds that inhibit the combustion of organic materials by scavenging free radicals that would otherwise encourage the spread of flames. These compounds are found in a wide variety of materials including paints, plastics, textiles, furniture and electronics. Mounting evidence, however, suggests that the non-reactive BFRs can easily leach into the environment and pose significant environmental and health concerns. PBDDs/PBDFs are often formed in the process of manufacturing brominated flame retardants and from the combustion of waste products containing flame retardants BFR. Therefore, this paper describes the general characteristics, management status, residual concentration in environments and analytical method.

• Journal of the Korean Institute of Gas
• /
• v.1 no.1
• /
• pp.1-6
• /
• 1997

In case of using the electrical apparatus in the hazardous atmosphere which exist flammable gas mixtures, There is a dangerosity of gas explosion accident by the electrical spark. The most general method to prevent the explosion by the spark is to use the flame-proof type electrical apparatus to isolate the ignition source. from the flammable atmosphere. But actualy it is impossible to isolate the ignition sources from the atmosphere. So it was needed to find the safe gap which prevent ignition of flammable atmosphere by transmission of flame or heat when a flammable gas mixture exploded inside the apparatus. In this study we tried to find the maximum experimental safe gap(MESG) of $H_2$-air, and $CH_4$-air mixtures by using the 8 litre spherical vessel with 25mm flange. The experiment parameter were ignition position, concentration and initial pressure before explosion. From the experiment the ignition position was affected to the MESG. MESG value was minimum near the stoichiometric concentration of gas mixtures, and according to the increase of initial pressure MESG was decreased.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.1
• /
• pp.76-86
• /
• 2015

KSLV-II, a new launch vehicle of Korea, requires a new launch complex(LC) for its own and proper launch operations. The new launch complex will be constructed in NARO Space Center neighboring KSLV-I launch complex for maximizing operation efficiency and economic matters. The launch complex consists of three ground support equipments, i.e., mechanical, electrical, and fuel in general. The fuel ground support equipment could be defined as a combination of systems for storage and supply of propellants and gases which are required by a launch vehicle. The compositions, functions and capabilities of fuel ground support equipment are introduced in this paper. In addition, basic design results of flame deflector configurations are included.

• Transactions of the Korean hydrogen and new energy society
• /
• v.25 no.1
• /
• pp.59-71
• /
• 2014

An experimental study has been conducted to investigate the heat transfer characteristics of laminar syngas/air mixture with 10% hydrogen content impinging normally to a flat plate of cylinder. Effects of impinging distance, Reynolds number and equivalence ratio as major parameters on heat fluxes of stagnation point and radial direction were examined experimentally by the direct photos and data acquisitions from heat flux sensor. In this work, we could find the incurved flame behavior of line shaped inner top-flame in very closed distance between flat plate and burner exit, which has been not reported from general gas-fuels. There were 3 times of maximum and 2 times minimum heat flux of stagnation point with respect to the impinging distance for the investigation of Reynolds number and equivalence ratio effect. It was confirmed that the maximum heat flux of stagnation point in 1'st and 2'nd peaks increased with the increase of the Reynolds number due to the Nusselt number increment. There was a third maximum rise in the heat flux of stagnation point for larger separation distances and this phenomenon was different each for laminar and turbulent condition. The heat transfer characteristics between the stagnation and wall jet region in radial heat flux profiles was investigated by the averaged heat flux value. It has been observed that the values of averaged heat flux traced well with the characteristics of major parameters and the decreasing of averaged heat flux was coincided with the decreasing trend of adiabatic temperature in spite of the same flow condition, especially for impinging distance and equivalence ratio effects.

• Korean Journal of Clinical Pharmacy
• /
• v.12 no.2
• /
• pp.55-64
• /
• 2002

Infection is one of the main causes of death in severe burn cases. Treatment of burn patient includes fluid therapy, wound care, complication care and antibiotic therapy for infection. The objective of this study was to evaluate the characteristics of burn patients, the type of isolated microorganisms and their susceptibility, and the systemic antibiotics used. This is a retrospective study of 126 burn patients treated in the Hanil General Hospital from January to December 2001. Total 126 patients were assessed with 103 males and 23 females (4.5:1). The average age was $34.8\pm17.6$ years and extent of burn $(TBSA\;\%)\;was\;24.5\pm18.5\%$. The burn was caused by electric accident $(47.6\%),\;flame\;(29.4\%),\;scalding\;(21.4\%),\;and\;chemical\;accident\;(1.6\%)$. The overall mortality rate was $7.14\%$ (9/126) and all expired patients were males. The average age (n=9) was $48.8\pm15.6$ yrs and the extent of burn was $65.0\pm19.0\%$. The causes of death were due to flame burns $(13.5\%)$ and electric burns $(6.7\%)$. The culture sites of the isolated microorganisms were wound $(85.3\%),\;sputum\;(9.3\%),\;urine\;(2.7\%),\;blood\;(1.3\%)\;and\;catheter\;tip\;(1.3\%)$. Pseudomonas aeruginosa was the most commonly isolated organism $(35\%)$, followed by Staphylococcus aureus $(30.1\%)$, Acinetobacter baumannii $(21.4\%)$, and Enterococcus spp. $(3.9\%)$. The number of systemic antibiotics administered was 4.5. The classes of the antibiotics were cephalosporines $(38.5\%)$, aminoglycosides $(31\%)$, quinolones $(13.3\%)$, penicillins $(12.4\%)$, carbapenems $(2.4\%)$, glycopeptides $(1.9\%)$ and others $(0.6\%)$. In conclusion, most of burn patients had wound infection and Pseudomonas aeruginosa was the most commonly isolated organism. Cephalosporins were administered the most frequently among antibiotics.

• Journal of the Korean Society for Railway
• /
• v.15 no.6
• /
• pp.682-687
• /
• 2012

This study is made to link up the policy analysis theory flame and practice concerning the analysis of the railroad logistics resources development policy and propose an alternative to feasibility for the railroad logistics resources development policy in general. The specific objectives to achieve the purpose of this research are as follow: First, In consideration of the railroad logistics resources development policy and theory of policy analysis idea and goals, for analysis of the railroad logistics resources development policy analysis are to be instituted more systematically. Second, the theory of the railroad logistics resources development policy analysis will be made more systematic and use it as basis of the said analysis for further.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.9 no.3
• /
• pp.101-119
• /
• 2005

For MEMS applications, the effects of the momentum and heat loss on the stability of laminar premixed flames in a narrow channel are investigated by high-fidelity numerical simulations. A general finding is that momentum loss promotes the Saffman-Taylor (S-T) instability which is additive to the Darrieus-Landau (D-L) instabilities, while the heat loss effects result in an enhancement of the diffusive-thermal (D-T) instability. These effects are also valid in nonlinear behavior of the premixed flame. The simulations of multiple cell interactions are also conducted with heat and momentum loss effects.