• Analytical Science and Technology
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• v.23 no.1
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• pp.89-96
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• 2010

In general, three types of fingerprints could be found at the crime scene: visible, plastic, and latent fingerprints. Examples of visible fingerprint include those made by blood, paint or ink. Plastic fingerprint are made from an impression of the finger on soft material as soap, wax, etc. Latent fingerprint are those of the invisible one to the human eye. Oil-contaminated fingerprints remained in the evidence, that are contaminated with the soybean oil, engine oil, lubricating oil or grease. Oil-contaminated fingerprints are special types of fingerprint evidence but the research for developing method regarding oil-contaminated fingerprints is a few. In this study, ultraviolet light source was employed for untreated oil-contaminated prints and the freeze-dry method with liquid nitrogen for freeze oil residue on the surfaces with sequence of developing oil-contaminated fingerprints with black and magnetic powders, cyanoacrylate (CA) fuming, Basic Yellow 40. The types of oil chosen for the experiment were soybean oil, LSA oil, engine oil and material surfaces selected for the experiment were glass, plastic aluminum plates. The aims of this study were to determine the appropriate developing methods for oil-contaminated fingerprints.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.44-49
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• 2005

Real-scale experimental study was performed to characterize the surface flame propagating velocity along the OF cable in the underground utility fire. Temperatures of oil filled OF cable and dried OF cable with the diameter of 90mn were measured using thermocouple and data log system. The hexane and alkyl-benzene oil were used as a fire source using the ignition device. As a result while the surface flame propagating velocity of the three cables was $0.06\~0.09cm/s$, the surface flame propagating velocity of the one cable was $0.028\~0.032cm/s$. Therefore, it was found that the surface propagating flame velocity of the three OF cables is $2.1\~2.8times$ faster than that of one OF cable case. The results show that the surface propagating flame velocity became larger as increase of the number of cable, the volume of alkyl-benzene oil in the cable. The characteristics of surface propagating flame velocity in the OF cable can be helpful to fire suppression system in utility.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1468-1473
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• 2013

This paper dealt with the propagation characteristics of acoustic signals produced by partial discharges and the positioning of PD origin in insulation oil to develop insulation diagnostic techniques of oil-immerged transformers. Electrode systems such as needle to plane, plane to plane, and particle electrodes were fabricated to simulate some defects of power transformers. In addition, the frequency spectrum and propagation characteristics of acoustic signals with partial discharge (PD) in insulation oil were analyzed. Although there were differences based on the type of defect, the frequency spectra of the acoustic signals measured by wide and narrow band acoustic emission (AE) sensors were distributed in the range of 50 kHz-400 kHz. Therefore, a narrowband AE sensor is suitable for the diagnosis of oil-immersed power transformers. We could find the position of the PD source with an error margin of 10% in the experiments by calculating the position of the PD occurrence using the time difference of arrival measured by five AE sensors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.1-14
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• 1999

To find characteristics and areas of greater risk of oil spill at the coastal waters in Korea, some of risk factors were analyzed with historical data of oil spill and marine traffic. As a result, it is characterized that frequency of oil spill is increasing year by year and greatest percentage of spill source is fishing boat. It is proposed that the ports of Ulsan, Yeosu, Incheon and Pusan will be designated as primary area of risk as they have a higher risk of oil spills and its response authority is required to maintain appropriate regional response capability for prompt and effective response to a future spill incident. In addition, the regional response equipments at Ulsan are examined under a assumption of a medium size spill and it is found that the use of chemical dispersant can be an alternative when mechanical containment and recovery is not feasible in this area, and the existing response equipments may be appropriate to address that size of spill. However, the response authority is required to maintain more numbers of stronger boom for unsheltered waters and more quantity of concentrate dispersant to disperse all spilled oils on the water, furthermore the response authority should be prepared for a possible future catastrophic spill with sufficient equipments.

• Resources Recycling
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• v.13 no.1
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• pp.3-13
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• 2004

The use of biomass has attracted extensive attention from the beginning of civilization. However, intensive researches on the biomass from the view point of the development of alternative energy have been carried out just recently. Fast pyrolysis, as a tool for the utilization of the biomass as the secondary energy source has drawn great attentions due to high applicability for the production of several valuable materials from biomass. This review paper focuses on the recent developments of pyrolysis process and reports the characteristics of bio-oil, which is the main product of fast pyrolysis of biomass.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3059-3064
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• 2013

In this study transesterification of Triglycerides (TG) from Jatropha curcas oil (JCO) with methanol for production of biodiesel was investigated over cerium impregnated ZSM-5 catalysts. NaZSM-5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as a source for cerium. They were characterized by X-ray diffraction (XRD), Thermogravimeteric analysis (TGA), $CO_2$-temperature programmed desorption, and $N_2$ adsorption/desorption analysis. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is an evident for 10 and 15% loading. The optimal yield of transesterification process was found to be 90% under the following conditions: oil to methanol molar ratio: 1:12; temperature: $60^{\circ}C$; time: 1 h; catalyst: 5 wt %. Here the yield of fatty acid methyl ester (FAME) was calculated through $^1H$ NMR analysis. The investigation on catalyst loading, temperature, time and reusability illustrated that these ceria impregnated NaZSM-5's were found to be selective, recyclable and could yield biodiesel at low temperature with low methanol to oil ratio due to the presence of both Lewis and Bronsted basicity. Hence, from the above study it is concluded that ceria impregnated ZSM-5 could be recognized as a potential catalysts for biodiesel production in industrial processes.

• KSBB Journal
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• v.23 no.6
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• pp.509-512
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• 2008

The hydrolysis reaction of soybean oil was conducted experimentally by various source enzymes. The analytical result of hydrolysate of soybean oil showed that the compositions were linoleic acid, olic acid, palmitic acid, and stearic acid in order. The enzymes CR-E and CC-E from Candida rufosa and Candida cylindracea had two hold or more hydrolysis conversions than those of Lipase 16, Novozyme 871, and Lipolase-100L under the same conditions. Therefore CR-E and CC-E were selected for further experiments. These two enzymes had similar ranges of optimun conditions as follows: pH 3-6, $35-45^{\circ}C$, and water to soybean oil ratio of 3.3 or above. They finally got conversions 95% above.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.373-382
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• 1994

This study was observed the effect of n6 and n3 polyunsaturated fatty acids of dietary corn oil and fish oil which was supplemented with similar levels of tocopherol in high fat diet on the levels of tocopherol, malondialdehyde ( MDA) productions of plasma and tissues of rats. Also RBC hemolysis, superoxide dismutase (SOD) and glutathione peroxidase (GSH Px) activities In liver were determined. Male Sprague Dawley rats were fed high fat (40%Cal) diet which was different only In fatty acid composition for 6 weeks. Dietary (arts were beef tallow(BT) as a source of saturated fatty acid, corn oil(CO) for n6 linoleic acid (LA) and fish oil(FO) for n3 eicosapentaenoic acid(EPA) + docosahexaenoic acid (DHA). Plasma and liver tocopherol levels were lowered by n3 PUy4 but there was no difference in malondialdehyde(MDA) level by different dietary PUFA. However, MDA content of RBC and hemolysis were increased by n3 PUFA. MDA content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver were increased in more unsaturated dietary fat groups. Especially, SOD activity was increased in proportion to the degree of fat unsaturation.

• Journal of Power Electronics
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• v.18 no.2
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• pp.395-406
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• 2018

Marine controlled-source electromagnetic transmitters (MCSETs) are important in marine electromagnetic exploration systems. They play a crucial role in the exploration of solid mineral resources, marine oil, and gas and in marine engineering evaluation. A DC-DC controlled-source circuit is typically used in traditional MCSETs, but using this circuit in MCSETs causes several problems, such as large voltage ringing of the high-frequency diode, heating of the insulated-gate bipolar transistor (IGBT) module, high temperature of the high-frequency transformer, loss of the duty cycle, and low transmission efficiency of the controlled-source circuit. This paper presents a clamping-diode circuit for MCSET (CDC-MCSET). Clamping diodes are added to the controlled-source circuit to reduce the loss of the duty ratio and the voltage peak of the high-frequency diode. The temperature of the high-frequency diode, IGBT module, and transformer is decreased, and the service life of these devices is prolonged. The power transmission efficiency of the controlled-source circuit is also improved. Saber simulation and a 20 KW MCSET are used to verify the correctness and effectiveness of the proposed CDC-MCSET.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.122-130
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• 2004

Crude oil is complex mixture of thousands of different organic compound formed from a variety of organic materials that are chemically converted under differing geological conditions over long periods of time. Also oil composition varies according to crude source, refining, processing, handling and storage. The oil fingerprint method is application of specific knowledge of petrochemicals and use of sophisticated analytical equipment and techniques to identify the source(s) of oil pollution. KNMPA currently utilizes three primary analytical techniques: Gas Chromatography (GC), Fluorescence Spectroscopy(FL) and Infrared Spectroscopy(IR). Of all these techniques, GC technique are most widely used. Gas Chromatography is used as a primary analytical method because high reliableness, high separating efficiency and repeatability, but it is timeconsumable. The study results of identification of waterborne spilled oil by Fast Gas Chromatograph method showed that analytical time is cut down to 30minutes in comparison with packed column method and chromatograms represent high resolution and high repeatability.