• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.175-180
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• 2004

Improving furnace efficiency is a high priority need for aluminum, glass, steel and other metal casting industries. Oxy-fuel combustion is considered to be one of the most effective method to improve thermal efficiency and reduce $NO_x$, SOx and $CO_2$ emissions for high temperature furnaces. The characteristics of an oxy-fuel flame, in particular its shape, radiation profile and exhaust gas composition are considerably different to those of an air-fuel burner. For this reason, a new approach is needed regarding factors such as burner design, power input levels, number and positioning strategies of burners and also control philosophies. In this paper will discuss the latest developments of high performance oxy-fuel combustion reheating furnace system. This high performance oxy-fuel combustion system will be shown to be technologically superior to other types of combustion systems in the areas of fuel efficiency, emissions and productivity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.300.2-300.2
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• 2016

Increasing of the demand for energy savings for buildings, thermal barrier films have more attracted. In particular, as heat loss through the windows have been pointed out to major problems in the construction and automobile industries, the research is consistently conducted for improving the thermal blocking performance for windows. The main theory of the technology is reflect the infrared rays to help the cut off the inflow of the solar energy in summer and outflow of the heat from indoors in winter to save the energy on cooling and heating. Furthermore, this is well known for prevent glare, reduces fading caused by harmful ultraviolet radiation and easy to apply on constructed buildings if it made as a film. In addition to these advantages, apply the transparent electrode to eliminate condensation by heating. Generally ITO is used as a transparent electrode, but is has a low stability in environmental factors. In this study, ITO and its alternative, ATO, is deposited by sputtering system and then the characteristic is evaluated each material based thermal barrier thin film. The optical property was measured on wide range of wavelength (200 nm 2500 nm) to know the transparency in visible wavelength and reflectivity in IR wavelength range. The electrical property was judged by sheet resistivity. Finally the changes of the temperature and current of the deposited film was observed while applying a DC power.

• Environmental Engineering Research
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• 제25권4호
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• pp.561-570
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• 2020

In the present study, dye decolorizing bacteria were isolated from water and soil samples, collected from textile industries in Jodhpur province, India. Two bacterial species namely, Bacillus pumilis and Paenibacillus thiaminolyticus were screened and identified based on biochemical characterization. The degradation efficiency of these two microorganisms was compared through optimization of pH, incubation time, initial dye concentration and inoculum size. B. pumilis and P. thiominolyticus were able to degrade 61% and 67% Red HE3B, 81% and 75% Orange F2R, 49.7% and 44.2% Yellow ME4GL and 61.6% and 59.5% Blue RC CT dyes of 800mg/l concentration respectively. The optimum pH and time were found to be 8 within 24 hours. The FT-IR analysis confirmed that microorganisms were able to degrade toxic azo dyes into a non-toxic product as proved through structural modifications to analyze chemical functions in materials by detecting the vibrations that characterize chemical bonds. It is based on the absorption of infrared radiation by the microbial product. Therefore, Bacillus pumilis and Paenibacillus thiaminolyticus are a promising tool for decolorization of dyes due to its potential to effectively decolorize higher azo dye concentrations (10-800 mg/L) and can be exploited for bioremediation.

• 동아시아식생활학회지
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• 제19권4호
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• pp.564-569
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• 2009

Antioxidative activities, total phenolic compounds and the sulforaphane contents of cooked broccoli extracts were studied. Total phenolic compounds were determined to be 0.96 mg/g(flower) and 0.76 mg/g(stem) in fresh broccoli extracts. The total phenolic compounds of cooked broccoli extracts showed 0.92 (1 min), 0.79 (3 min), 0.67 (10 min) mg/g when a boiling process was used and 1.27 (1 min) mg/g when a steaming process was used. In the DPPH assay, the steam process showed the highest free radical scavenging capacities. Sulforaphane has been of increasing interest in the nutraceutical and phamaceutical industries due to its anti-cancer effect. Sulforaphane was isolated from fresh and boiled, steamed broccoli using dichloromethane as an extract solvent. The sulforaphane contents of fresh broccoli were higher in the flower (14.78 mg/kg) than in the stem (6.16 mg/kg). The sulforaphane content dramatically decreased after the boiling ($100{\pm}2^{\circ}C$) or steaming ($100{\pm}2^{\circ}C$) processes were used.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1995년도 제4회 학술강연회논문집
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• pp.171-175
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• 1995

Semiconductor diode lasers that can generate one watt or more of optical energy for tens of milliseconds (quasi continuous wave) are now readily available. Several researchers have demonstrated that this power level, when properly coupled, can reliably initiate pyrotechnic mixtures. This means that the initiator containing the pyrotechnic can be protected against inadvertent initiation from electromagnetic radiation or electrostatic discharge by a conducting Faraday cage surrounding the explosive. Only a small dielectric window penetrates the housing of the initiator, thereby eliminating the conductors necessitated by a bridgewire electroexplosive device. The diode laser itself, however, functions at a low voltage (typically 3 volts) and hence is susceptible to inadvertent function from power supply short circuits, electrostatic discharge or induced RF energy. The rocket motor arm-fire device de-scribed in this paper uses a diode laser, but protects it from unintentional function with a Radio Frequency Attenuating Coupler (RFAC).The RFAC, invented by ML Aviation, a UK company, transfers power into a Faraday cage via magnetic flux, thereby protecting the diode, its drive circuit and the pyrotechnic from all electromagnetic and electrostatic hazards. The first production application of a diode laser and RFAC device was by the Korean Agency for Defense Development.

• International Journal of Ocean System Engineering
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• 제1권1호
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• pp.46-51
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• 2011

In a line heating process for hull forming, the phase of the steel transforms from austenite to martensite, bainite, ferrite, or pearlite depending on the actual speed of cooling following line heating. In order to simulate the water cooling process widely used in shipyards, a heat transfer analysis on the effects of impinging water jet, film boiling, and radiation was performed. From the above simulation it was possible to obtain the actual speed of cooling and volume percentage of each phase in the inherent strain region of a line heated steel plate. Based on the material properties calculated from the volume percentage of each phase, it should be possible to predict the plate deformations due to line heating with better precision. Compared to the line heating experimental results, the simulated water cooling process method was verified to improve the predictability of the plate deformation due to line heating.

• 대한조선학회논문집
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• 제42권5호
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• pp.472-478
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• 2005

From a rapid cooling to a slow cooling in the actual cooling process in shipyards, the phase of steel becomes martensite, bainite, ferrite, and pearlite. In order to simulate the cooling process, heat transfer analysis was performed considering the effects of impinging water jet, film boiling, and radiation. From above simulation it is possible to find the cooling speed at the inherent strain region and volume percentage of all phases in that region. By the suggested method based on the precise material properties calculated from volume percentage of all phases, it will be possible to predict the plate deformations by line heating more precisely. It is verified by comparing with some experimental results that the present method is very effective and efficient.

• 한국미생물·생명공학회지
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• 제49권2호
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• pp.167-173
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• 2021

Reactive oxygen species (ROS) disrupt the cellular redox balance, exert cytotoxic effects, and consequently promote the development of various diseases in humans. Previous studies have reported that antioxidants counteract the adverse effects of ROS. Several studies examine the whitening effects of various agents based on their ability to inhibit tyrosinase activity. Tyrosinase is a critical enzyme involved in the synthesis of melanin, which protects the skin against radiation. Various agents exhibiting antioxidant and tyrosinase inhibitory activities have been synthesized. However, these synthetic drugs are associated with toxicity, decreased safety, and poor skin penetration in vivo, which has limited the clinical application of synthetic drugs. This study examined the antioxidant and tyrosinase inhibitory activities of some microalgae. The methanol, dichloromethane, and ethyl acetate extracts of four microalgal species (Tetraselmis tetrathele, Dunaliella tertiolecta, Platymonas sp., and Chaetoceros simplex) were prepared. The physiological and whitening effects of microalgal extracts were investigated by measuring the antioxidant and tyrosinase inhibitory activities. The ethyl acetate extract of D. tertiolecta exhibited the highest antioxidant and tyrosinase inhibitory activities. Future studies must focus on examining the whitening effects of microalgae on cell lines to facilitate the development of microalga-based therapeutics for skin diseases, functional health foods, and whitening agents. Thus, microalgae have potential applications in the pharmaceutical, food, and cosmetic industries.

• 방사성폐기물학회지
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• 제21권4호
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• pp.481-487
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• 2023

Concerning the apprehensions about naturally occurring radioactive materials (NORM) residues, the International Atomic Energy Agency (IAEA) and its member nations have acknowledged the imperative to ensure the radiation safety of NORM industries. Residues with elevated radioactivity concentrations are predominantly produced during NORM processing, in the form of scale and sludge, referred to as technically enhanced NORM (TENORM). Substantial quantities of TENORM residues have been released externally due to the dismantling of NORM processing factories. These residues become concentrated and fixed in scale inside scrap pipes. To assess the radioactivity of scales in pipes of various shapes, a Monte Carlo simulation was employed to determine dose rates corresponding to the action level in TENORM regulations for different pipe diameters and thicknesses. Onsite gamma spectrometry was conducted on a scrap iron pipe from the titanium dioxide manufacturing factory. The measured dose rate on the pipe enabled the estimation of NORM concentration in the pipe scale onsite. The derived action level in dose rate can be applied in the NORM regulation procedure for on-site judgments.

• 한국식품영양과학회지
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• 제40권10호
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• pp.1378-1383
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• 2011

본 연구는 폐자원으로 버려지는 버찌의 활용 증대방안 모색을 위한 기초자료 마련을 위해 버찌의 에탄올 추출물에 0~20 kGy 선량으로 감마선 조사를 실시하고, 이에 따른 항산화활성 변화를 측정하였다. 총 폴리페놀 함량 측정결과, 10 kGy 조사구에서 30.35 mg/g으로 가장 높은 값을 나타내었으나 감마선 조사에 따른 일정한 증가나 감소의 경향은 나타내지 않았다. DPPH radical 소거능 측정결과 10 kGy 조사구에서 327.52 ppm으로 가장 낮은 $IC_{50}$값을 나타내 가장 높은 활성을 나타내었으며 대체적으로 비조사구보다는 조사구에서 높은 활성을 나타내었다. 환원력 측정 결과, 2.5 mg/mL 이하 농도에서 비조사구에 비해 조사구에서 높은 활성을 나타내었고 20 kGy 조사구에서 대체적으로 높은 환원력을 나타내었다. 아질산염 소거능을 측정한 결과 pH 4.2 이하의 pH에서 조사구 및 비조사구 모두 73~94% 이내의 높은 소거능을 나타내 pH 의존적인 아질산염 소거능을 보였으나 조사에 따른 활성 증가는 나타내지 않았다. FRAP value를 측정결과 3 kGy 조사구에서 0.38 mM로 가장 높은 활성을 나타내었다. 결론적으로 버찌 에탄올 추출물에 대한 감마선 조사는 일부 선량에서 추출물의 항산화 활성 증가를 나타내며, 사용목적에 따른 적정 선량의 감마선 조사는 생리활성물질의 증가를 유도하여 산업적인 면에서 효율적으로 이용될 수 있을 것으로 사료된다.