• Analytical Science and Technology
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• v.5 no.1
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• pp.25-31
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• 1992

A benzene synthesizer was manufactured and has been used for the treatment of the various samples such as wood, charcoal, shell and soil for radiocarbon dating using liquid scintillation counter. The experimental conditions were optimized in each successive step of the synthesis of carbon dioxide, acetylene and the final product of benzene. Fifteen hours operation of the benzene synthesizer leads to product yields consistently in excess of 85% based on the content of calcium carbonate for the organic samples. Purity of the synthesized benzene was measured to be more than 99.9% by GC/MS.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.271-277
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• 2015

The present paper discusses about noble idea on various reactions including hydrides, hydrogen peroxide and nano-sized metal powders, which do not emit toxic materials as well as carbon dioxide. Here in this paper, the very first-ever concept that heat energy can be generated from the direct reaction between sodium borohydride and hydrogen peroxide is presented. Sodium hydride as fuel can supply hydrogen reacting with oxygen provided by the decomposition of hydrogen peroxide solution. Solid sodium borohydride can be resolved in water and treated as liquid solution for the easy handling and the practical usage although its solid powder can be directly mixed with hydrogen peroxide for the higher reactivity. The thermodynamic analysis was conducted to estimate adiabatic reaction temperatures from these materials. The preliminary experiment on the reactions conducted using sodium borohydride powder and hydrogen peroxide water solution revealed that the self-propagating reaction can occur and that its reactivity increases with an increase of hydrogen peroxide concentration.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.543-551
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• 2007

The performance characteristics of water-chilling heat pump using $CO_2$ with respect to variation of inlet temperature and mass flow rate of secondary fluid was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter-flow-type heat exchangers with concentric dual tubes, which ate made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2.4 m length. The experimental results were summarized as the followings : As inlet temperature of secondary fluid in the gas cooler increases from $10^{\circ}C$ to $40^{\circ}C$, the compressor work, heating capacity and heating COP were varied to 37.8%, -13%, -35.9%, respectively. The heating capacity, compressor work, heating COP were turned into 23.3%, 6.42%, 13.1%, respectively when ass flow rate of secondary fluid in the evaporator increases from 70 g/s to 150 g/s. The above tendency is similar with performance variation with respect to temperature variation of secondary fluid in the conventional vapor compression cycle.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3181-3188
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• 2008

The supercritical $CO_2$ Brayton cycle energy conversion system is presented as a promising alternative to the present Rankine cycle. The principal advantage of the S-$CO_2$ gas is a good efficiency at a modest temperature and a compact size of its components. The S-$CO_2$ Brayton cycle coupled to a SFR also excludes the possibilities of a SWR (Sodium-Water Reaction) which is a major safety-related event, so that the safety of a SFR can be improved. KAERI is conducting a feasibility study for the supercritical carbon dioxide (S-$CO_2$) Brayton cycle power conversion system coupled to KALIMER(Korea Advanced LIquid MEtal Reactor). The purpose of this research is to develop S-$CO_2$ Brayton cycle energy conversion systems and evaluate their performance when they are coupled to advanced nuclear reactor concepts of the type under investigation in the Generation IV Nuclear Energy Systems. This paper contains the research overview of the S-$CO_2$ Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.131-136
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• 2008

The oil separation in an oil separator is one of the most important characteristics for proper compressor operation. In this study, a gravity type of oil separator is used. Oil separation characteristics has been investigated for $CO_2$/PAG mixture in the range of oil concentration 0 to 5 weight-percent and the mixture temperature range of $5^{\circ}C$ to $15^{\circ}C$ and $70^{\circ}C$ to $90^{\circ}C$. The results obtained indicate that the oil separation is increased with an increase in the oil concentration. It is also found that the oil separation in liquid state is increased with an increase in the mixture temperature while the oil separation in gas state is decreased.

• Journal of Oral Medicine and Pain
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• v.23 no.3
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• pp.249-255
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• 1998

Mucoceles of the minor salivary glands are the most common cystic lesions affected the oral mucosa. They are believed to be the result of trauma to the salivary duct caused, for example, by biting the lip, cheek, or tongue. Surgical excision has been the most common treatment for these lesions, but occasional recurrences develop after excision because surgical trauma may damage the surrounding minor salivary glands Although various alternative nonsurgical approaches, such as steroid infection, application of gamma-linolenic acid, have also been reported, they are not used routinely, Lasers, particularly the carbon dioxide laser, have been used in the management of mucoceles. Although this treatment requires specialized equipment. Cryotherapy is another effective nonsurgical method for treating mucoceles. Clinically, cryotherapy has primarily been applied to the treatment of leukoplakia and hyperplastic, granulomatous, vascular, and pigmented lesions. Limited information, however, is available on the application of cryotherapy in salivary gland lesions, including mucoceles. A simple and easy cryotherapy to treat a mucocele on the lower lip is described. A 25 years old female patient with a mucocele on the lower lip was treated by direct application of liquid nitrogen with a cotton swab. The lesion was exposed to 4 or 5 cycles composed of freezings of 10-30 s and thawings of double the freezing times. No anesthesia was required. The lesion nearly disappeared without scar 10 days after the cryotherapy. Cryotherapy has become an established nonsurgical method, characterized by its simple application, therapeutic effectiveness, painless during the procedure and low incidence of secondary infection and hemorrhage.

• Korean Journal of Clinical Pharmacy
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• v.19 no.1
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• pp.65-68
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• 2009

Disposal infusion device is known to be useful for chemotherapy. Anti-cancer drug can be released by the force of carbon dioxide or balloon. In this study, we compared the$Anapa^{(R)}$ (LC0020) with B Company (LV2 ml) in terms of infusion rate and stability. Infusion rate was determined every six minute using software, MSI08IH. Stability of 5-fluorouracil was examined periodically using a High Performance Liquid Chromatography. Infusion rates of gas-derived $Anapa^{(R)}$ device were 2.29, 1.86, 1.98 ml/hr and those of balloon-derived B Company device were 1.71, 1.58, 1.37 ml/min. There were no significant differences in stability of 5-fluorouracil between $Anapa^{(R)}$ and B Company devices. In summary, gas-derived $Anapa^{(R)}$ device is thought to be comparable or superior to balloon-derived B Company device as far as infusion rate and stability are concerned. We expect that $Anapa^{(R)}$ as a home infusion device can be employed to improve a quality of life and compliance of cancer patients.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.3
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• pp.88-93
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• 2009

Lubricant oil is needed in air conditioning and refrigeration system because the compressor requires oil to prevent surface to surface contact between its moving parts, to remove heat, to provide sealing, to keep out contaminants, to prevent corrosion, and to dispose of debris created by wear. Thus, the oil separation in an oil separator is one of the most important characteristics for proper compressor operation. In this study, a gravity type of oil separator is used. Oil separation characteristics have been investigated for $CO_2$/PAG mixture in the range of oil concentration 0 to 5 weight-percent and the mixture temperature range of $0^{\circ}C$ to $15^{\circ}C$ at 50 bar and $70^{\circ}C$ to $90^{\circ}C$ at 80 bar. The results obtained indicate that the oil separation is increased with an increase in the oil concentration. It is also found that the oil separation in liquid state is increased with an increase in the mixture temperature while the oil separation in gas state is decreased.

• Journal of ILASS-Korea
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• v.27 no.3
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• pp.155-160
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• 2022

Recently, major developed countries have strengthened automobile fuel efficiency regulations and carbon dioxide emission allowance standards to curb climate change caused by global warming worldwide. Accordingly, research and manufacturing on electric vehicles that do not emit pollutants during actual driving on the road are being conducted. Several automobile companies are producing and testing electric vehicles to commercialize them, but it takes a lot of manpower and time to test and evaluate mass-produced electric vehicles with driving mileage of more than 300km on a per-charge. Therefore, in order to reduce this, a simulation model was developed in this study. This study used vehicle information and MCT speed profile of small electric vehicle as basic data. It was developed by applying Simulink, which models the system in a block diagram method using MATLAB software. Based on the vehicle dynamics, the simulation model consisted of major components of electric vehicles such as motor, battery, wheel/tire, brake, and acceleration. Through the development model, the amount of change in battery SOC and the mileage during driving were calculated. For verification, battery SOC data and vehicle speed data were compared and analyzed using CAN communication during the chassis dynamometer test. In addition, the reliability of the simulation model was confirmed through an analysis of the correlation between the result data and the data acquired through CAN communication.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.115-116
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• 2023

This study aims to investigate and improve the carbon dioxide sequestration capability and the mechanical properties of non-hydraulic low calcium silicate cement especially designed for CO₂ reaction and ordinary Portland cement subjected to the carbonation curing facilitating pH swing method. Nitric acid (HNO₃) was utilized as an liquid for the mixing of cement paste to enhance the initial dissolution of Ca ions from the cements by promoting low pH environment and prevent the direct precipitation of Ca with the anion, owing to the high solubility of Ca(NO₃)₂ in water. The results presented that the higher the concentration of HNO₃, the higher the compressive strength and CO₂ sequestration (until 0.1 M). Ca dissolution caused by the harsh acid attack onto the anhydrous cement particle lead to the higher carbonation reaction degree, forming abundant CaCO₃ crystals after the reaction. However, cement paste mixed with excessively high concentration of HNO₃ presented deterioration due to the too harsh pH environment and abundant NO₃- ions which are known to retard the reaction of cement.