• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.127-133
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• 1996

The development of high resolution capillary columns and a large variety of different detectors led to a strong position of gas chromatography in instrumental analysis. Every effort has been made to solve sophisticated separation problems by column switching. Nowadays, several systems are commercially available for this purpose. The principle and the capabilities of multidimensional gas chromatography(MDGC) are illustrated by different applications in the field of modern flavor and essential oil research.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.222-222
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• 2011

Plastic product is increasing by the growth of its demand and most of refused plastics are incinerated or reclaimed. However, the refused plastic is not easily decomposed and has the environmental problem with its various toxic gas in case of incineration. Therefore, many countries such as USA, Japan, Germany and other developed industrial countries as well as Korea are interested in studying the recyclable resource of refused plastic. The macromolecular waste pyrolysis has the advantage of collecting of raw materials in high price and can at least get fuel gas or oil with high heat capacity. It also discharges low waste gas and low toxic gas including SOx, NOx and HCl heavy metals. However, pyrolyzed oil includes enough excess unsaturated hydrocarbons to form tar, which can cause the nozzle of engines to plug when pyrolyzed oil is used as fuel. Activated carbon was proven to have prominent adsorption capability among the other adsorbents that were mainly composed of carbon. This study examined the possibility of application in activated charcoal of its solid formation by analysing the feature of pyrolysis which is one of the chemical recycling methods and getting chemical analysis of the product and activated energy. Analyze the element of the oil produced by pyrolysis using GC-MS. The experiment of tar adsorption using fly-ash showed that fly-ash improved the optical intensity of pyrolyzed oil and decreased oxygen compounds in the pyrolyzed oil.

• Tribology and Lubricants
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• 제22권3호
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• pp.155-163
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• 2006

Ring, groove and cylinder bore wear may not be a problem in most current automotive engines. However, a small change in ring face, groove geometry and cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blowby and oil consumption in an engine. Therefore, by predicting the wear of piston ring face, ring groove and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Being based on the calculation of gas flow amount by the theory of piston ring dynamics and gas flow, and the calculation of oil film thickness and friction force by the analysis of piston ring lubrication, the calculation theory of oil amount through top ring gap into combustion chamber will be set. This is estimated as engine oil consumption. Furthermore, the wear theories of ring, groove and cylinder bore are included. Then the each amount of wear is to be obtained. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. Next, the calculated amount of oil consumption and wear are compared with the guideline of each part's wear and oil consumption. So, the timing of part repair and engine life cycle can be predicted in advance without performing engine durability test. The wear data of rings, grooves and cylinder bore are obtained from three engines before and after engine durability test. The calculated wear data of each part are turn out to be around the band of averaged test values or a little below.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권12호
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• pp.578-584
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• 2005

This paper describes development of management software for transformers based on artificial intelligent analysis technology of dissolved gases in oil. Fault interpretation using the artificial intelligent analysis is performed by the artificial neural network and a rule based on the analysis of dissolved gases. The used gases are acetylene($C_{2}H_{2}$), hydrogen($H_2$), ethylene($C_{2}H_{4}$), methane($CH_4$), ethane($C_{2}H_{6}$), carbon monoxide(CO) and carbon dioxide($CO_2$). This software is mainly composed of gases input, fault's causes, expected fault's phenomena in detail, the decision on maintenance as well as report and gas trend windows. It is indicated that this is very powerful software for the efficient management of oil-immersed transformers using data analysis of gas components.

• Journal of Nutrition and Health
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• 제13권4호
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• pp.159-166
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• 1980

Methods for the determination of sterols in sesame oils were studied. The sesame oils were saponified and the sterols isolated from the unsaponifiable matter by Florisil column chromatography, and the individual components were determined by means of gas chromatography. Campesterol, ${\beta}-sitosterol$, stigmasterol were found in sesame oil including unknown Ⅰ and Ⅱ. The use of SE-30 gas chromatographic column allows the slow elution, duplication of peaks and relatively low reproducibility, therefore, 3% OV-17 was suitable for the sterol analysis. The result of this study showed that contents of sterols in sesame oil were campesterol 8.4%, stigmasterol 4.5%, ${\beta}-sitosterol$ 33.9% and others 53.0% involving 8.8% of unknown I and 44.3% of unknown Ⅱ. There has been no specific test available for identifying the sesame oil among common edible oils. But the ratio of sterols in sesame oils allowed the estimation of genuiness. The ratio of sterols vs. campesterol in genuine sesame oils were stigmasterol 0.3- 0.6, ${\beta}-sitosterol$ 3.0-3.8 and unknown Ⅱ 3.0, respectively. The 65 samples were composed of genuine sesame oil 40%, mixed rape seed oil 3%, cotton seed oil 1. 5% others were reused soybean oil or re-extracted oil.

• The Journal of Asian Finance, Economics and Business
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• 제5권2호
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• pp.25-33
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• 2018

In the globalization and free trade era, the current account deficit problem is a common phenomenon experienced by most countries, both developing and developed countries. Also with managed floating regime of exchange rate, it becomes very important to analyze the dynamics of current account balance which determine the trade. The deficit condition has lasted for four years in Indonesia, as well the deficit value above the value of the surplus that has been experienced during the period 2005-2011. This study is firstly aim to examine the condition of the deficit which happens in the export and import, manufactured goods and oil and gas, whether related to the transaction of goods and services. We try to build a predicted model which near the actual. Then, the focuses examines an exchange rate volatility impact on current account deficit. The model used in this research is a simultaneous model of Indonesia current account deficit from 2005 to 2014. The simulation result indicated that depreciation increase surplus to current account deficit. The decrease of export manufactured goods (non oil and gas) higher than the increase of import. For the oil and gas sector, depreciation of the rupiah against the US dollar results in an increased burden of higher oil and gas imports due to import transactions.

• Ocean Systems Engineering
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• 제6권1호
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• pp.99-115
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• 2016

In meeting the technical needs for deepwater conditions and overcoming the shortfalls of single-layer pipes for deepwater applications, pipe-in-pipe (PIP) systems have been developed. While, for PIP pipelines directly laid on the seabed or with partial embedment, one of the primary service risks is lateral buckling. The critical axial force is a key factor governing the global lateral buckling response that has been paid much more attention. It is influenced by global imperfections, submerged weight, stiffness, pipe-soil interaction characteristics, et al. In this study, Finite Element Models for imperfect PIP systems are established on the basis of 3D beam element and tube-to-tube element in Abaqus. A parameter study was conducted to investigate the effects of these parameters on the critical axial force and post-buckling forms. These parameters include structural parameters such as imperfections, clearance, and bulkhead spacing, pipe/soil interaction parameter, for instance, axial and lateral friction properties between pipeline and seabed, and load parameter submerged weight. Python as a programming language is been used to realize parametric modeling in Abaqus. Some conclusions are obtained which can provide a guide for the design of PIP pipelines.

• 한국연소학회지
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• 제14권1호
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• pp.19-24
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• 2009

A novel low NOx oil burner of 0.7 MW (for a 1 ton steam/hr industrial boiler) was designed and tested to investigate the combustion characteristics through in-flame measurement and flue gas analysis. Flame shape was observed by CCD camera and $CH^*/{C_2}^*$ radical distribution in the flame were observed, along with measurement of flue gas composition such as NOx and CO, for various heat inputs, excess airs and pressure of the fuel spary nozzles. The flame showed the two-zone structure: fuel-rich and fuel-lean zone, which was very favorable for the low-NOx combustion, and the NOx emission for haevy oil combustion was significantly reduced to < 150 ppm at 4 % $O_2$, compared with the NOx level of a conventional heavy oil burner.

• 설비공학논문집
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• 제22권4호
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• pp.181-188
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• 2010

The objectives of this study are to analyze the possibility of the landfill gas recycling for the middle and small scale landfills where the recycling facilities are not installed in Korea. It was found that the power generation plants by landfill gas were installed in domestic 15 landfills and the gas engine generation was adopted in 14 places. As the result of economic analysis, the landfill gas recycling is found to be available in 12 places and CERs of 153,693 $tCO_{2e}$ can be secured per year. Through the reduction of the air pollutants and VOCs, the social benefits of 730 million won accrue per year. Also, the power production of 18.8 GWh will substitute the crude oil imports of 4,048 TOE and the revenue of 2.49 billion won is expected to power trading. It is also found that the power generation plants by landfill gas will give the social benefits such as the reduction of the environmental problems and the substitution effect of crude oil imports.

• Tribology and Lubricants
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• 제22권3호
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• pp.131-136
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• 2006

Cylinder bore wear may not be a problem in most current automotive engines. However, a small change in cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blow-by and oil consumption in an engine. Therefore, by predicting the wear of piston ring face, ring groove and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Being based on the calculation of gas flow amount by the theory of piston ring dynamics and gas flow, and the calculation of oil film thickness and friction force by the analysis of piston ring lubrication, the calculation theory of oil amount through top ring gap into combustion chamber will be set. This is estimated as engine oil consumption. Furthermore, the wear theories of ring, groove and cylinder bore are included. Then the each amount of wear is to be obtained. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. Next, the calculated amount of oil consumption and wear are compared with the guideline of each pare0s wear and oil consumption. So, the timing of part repair and engine life cycle can be predicted in advance without performing engine durability test. The wear data of cylinder bore diameter are obtained from three engines before and after engine durability test. The calculated wear data of cylinder bore diameter are turn out to be twice of the lower bound of averaged test values at TDC and the lower bound at BDC.