• Membrane and Water Treatment
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• v.7 no.4
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• pp.341-353
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• 2016

Papermaking reconstituted tobacco is an important strategy for recycling the waste tobacco residues. To indentify the influences of the inorganic components on harmful components delivery in cigarette smoke, a self-made electrodialysis stack was assembled to desalt the tobacco extract. The influences of the applied current and extract content on the removal rate of the inorganic ions were investigated. Results indicated that the applied current was a dominant impact on the desalination performance. High currents lower than the limiting current density could accelerate the desalting efficiency but cause higher energy consumption. A current of 2 A, or current density of ${\sim}11mA{\cdot}cm^{-2}$, was an optimal choice by considering both the energy consumption and desalting efficiency. A 20% tobacco extract was an appropriate content for the electrodialysis process. More than 90% of inorganic ions could be removed under the optimum condition. The preliminary result indicated that removal of inorganic components was beneficial to decrease the harmful component delivery in cigarette smoke. Naturally, ED is an environmentally friendly and high-effective technology for desalting the tobacco extract.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.5
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• pp.393-400
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• 2012

The modularized equalizers normally use additional components among the modules in the long series-connected lithium-ion battery string. In these approaches, the overall systems are heavy, bulky, and high-priced. Furthermore, the losses related to additional components decrease the system efficiency. To avoid these problems, a modularized equalizer, which has no additional components among the modules, is required. This paper proposes a novel control scheme using the magnetizing energy of the multi-winding transformer for the module equalization. In this scheme, the high duty cycle is applied to the module where the voltage is higher than the reference voltage and the low duty cycle is applied to the module where the voltage is lower than the reference voltage. Due to the different duty cycle, more electric charges are transferred from high voltage module to the low voltage module during the turn-off switching interval. Using the proposed control scheme, the equalizer system does not suffer from the size, cost, and loss related to the modularization. The experimental results are provided to verify the effectiveness of the proposed modularized equalizer.

• ETRI Journal
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• v.38 no.4
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• pp.675-684
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• 2016

This paper demonstrates the effect of fluoride-based plasma treatment on the performance of $Al_2O_3/AlGaN/GaN$ metal-insulator-semiconductor heterostructure field effect transistors (MISHFETs) with a T-shaped gate length of $0.20{\mu}m$. For the fabrication of the MISHFET, an $Al_2O_3$ layer as a gate dielectric was deposited using atomic layer deposition, which greatly decreases the gate leakage current, followed by the deposition of the silicon nitride layer. The silicon nitride layer on the gate foot region was then selectively removed through a reactive ion etching technique using $CF_4$ plasma. The etching process was continued for a longer period of time even after the complete removal of the silicon nitride layer to expose the $Al_2O_3$ gate dielectric layer to the plasma environment. The thickness of the $Al_2O_3$ gate dielectric layer was slowly reduced during the plasma exposure. Through this plasma treatment, the device exhibited a threshold voltage shift of 3.1 V in the positive direction, an increase of 50 mS/mm in trans conductance, a degraded off-state performance and a larger gate leakage current compared with that of the reference device without a plasma treatment.

• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.481-490
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• 2012

Evaluation of chloride penetration is very important, because induced chloride ion causes corrosion in embedded steel. Diffusion coefficient obtained from rapid chloride penetration test is currently used, however this method cannot provide a correct prediction of chloride content since it shows only ion migration velocity in electrical field. Apparent diffusion coefficient of chloride ion based on simple Fick's Law can provide a total chloride penetration magnitude to engineers. This study proposes an analysis technique to predict chloride penetration using apparent diffusion coefficient of chloride ion from neural network (NN) algorithm and time-dependent diffusion phenomena. For this work, thirty mix proportions with the related diffusion coefficients are studied. The components of mix proportions such as w/b ratio, unit content of cement, slag, fly ash, silica fume, and fine/coarse aggregate are selected as neurons, then learning for apparent diffusion coefficient is trained. Considering time-dependent diffusion coefficient based on Fick's Law, the technique for chloride penetration analysis is proposed. The applicability of the technique is verified through test results from short, long term submerged test, and field investigations. The proposed technique can be improved through NN learning-training based on the acquisition of various mix proportions and the related diffusion coefficients of chloride ion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.121-128
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• 1989

Volatile compounds were collected by simultaneous distillation extraction and carbon dioxide method, and analyzed by GC and GC-MS. The neutral fraction obtained from the whole steam volatile concentrate 55 kinds of components, phenolic fraction had 4 kinds of components, basic fraction had 13 kinds of components and 10 kinds of components were in acidic fraction. Alcohols, propanols, butanols, octanols, dodecanols etc. and aldehydes, pentanals, hexanal, 2-methyl-1-propanal, heptenal etc. were highly increased after boiled and roasted. And these compounds were contributed to formation of filefish flavor. The molecular ion peak of phenolic fraction was generally appeared in the range 100 to about 160. From the basic fraction, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-3,5-di-methylpyrazine and 2-methylpyridine were identified. The contents of basic compounds and furans obtained from the neutral fraction were increased at the higher heating temperature. The flavor of acidic fraction was influenced by the low molecular as isovaleric and valeric acid.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.2
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• pp.119-127
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• 1999

This study was conducted to evaluate the effect of cigarette papers, flax and wood, on the delivery of mainstream smoke. The main components of cigarette papers were cellulose, hemicellulose, lignin, and pectin. Lignin contents, known as precursor of smoke's phenolic compounds, of the flax and wood cigarette papers were 5.8% and 10.6%, respectively. The pyrolysis products of cigarette papers were similar by the profile of total ion chromatogram. But, the area % of some components, such as 1,3-cyclopentanedione, 3,5- dimethyl cyclopentane-1,2-dione, 2-hydroxy-3-methyl-2-cyclopentenone, dihydro-2(3H)-furanone, 3-methyl-2(5H)-fruanone, and 5-methyl-2-furaldehyde delivered through pyrolysis of the flax cigarette paper were higher than that of wood cigarette paper. Otherwise, the area % of some components, such as 2-methyl-cyclopentene-l-one), 2,3-butanedione, 2-cyclopentene-l-one, and 5-hydroxy-2-methyl-furaldehyde, 2-furaldehyde delivered through pyrolvsis of the wood cigarette paper were higher than that of flax cigarette paper. To identify the difference between two cigarette papers, we used the cigarette column filled with the cut cigarette paper instead of the cut tobacco leaf. The amounts of semi-volatile fraction delivered from flax cigarette paper was more than that of wood cigarette paper. But, by using the cut tobacco, there was no big difference of delivery amount between flax and wood cigarette papers. Also, aroma of TPM by collecting from brening cut tobacco wrapped in flax and wood papers showed a different pattern by the electonic nose system. Although the difference between two cigarette papers by using the cut tobacco was smaller than that of cut cigarette paper, this result indicated that the fax and wood had the different effects on the delivery of smoke components as shown in the sensory test results.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.274-283
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• 1996

In this study, the effects of red ginseng components [ginsenosides (total saponins and $Rg_1$) on the function of ryanodine receptor (RyR) -$Ca^{2+}$ release channel complex protein (named as RyR or $Ca^{2+}$ channel), a membrane protein in sarcoplasmic reticulum (SR) of rabbit skeletal muscle were examined at the SR vesicle's level and the molecular levels with Chaps-solubilized and purified $Ca^{2+}$ channel protein and with reconstituted proteoliposomes by dialysis. The results were as follows. 1. The binding of ryanodine known as inhibitor of muscle contraction to the RyR was decreased at the whole range of concentration ($10^2$~$10^7$%) by these two ginseng components. In heavy SR vesicles, Chaps-solubilized and purified $Ca^{2+}$ channel protein, and reconstituted vesicles, its maximal inhibition by total saponins was shown at the concentration of $10^3$, $10^3$%, and $10^5$% respectively, and by gin- senoside $Rg_1}$) each was $10^3$%, $10^3$%, and $10^4$%. 2. The release of $Ca^{2+}$ ion through $Ca^{2+}$ channel in heavy SR vesicles and reconstituted proteoliposomes was increased as a whole by these two ginseng components, and particularly maximal release by both of them was shown at the range of $10^4$~$10^6$%. These results were seemed to be caused by conformational change of $Ca^{2+}$ release channel protein (RyR) by red ginseng components [ginsenosides (total saponins and $Rg_1}$).

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.161-166
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• 2009

The purpose of the present study is to develop a simple, fast and sensitive LC/MS method for simultaneous separation and the determination of an active component in the oriental medicinal mushroom Cordyceps militaris. Based on this work, the contents of cordycepin in Cordyceps militaris fruiting cultivated on various media were determined and compared. And also, the nutritional components such as minerals and vitamins were determined in order to provide useful information to consumer as a food material. The analysis methods of nutritional components were chosen on the basis of AOAC. The optimum separation for cordycepin was achieved using a solvent gradient consisting of the mixture of 0.1% formic acid in methanol (solvent B) in a background of 0.1% formic acid in water (solvent A) as a mobile phase and a 3.0${\times}$150 Waters XTera column. Selective ion monitoring (SIR) mode ([M+H]+ at m/z 252) was used for quantitative analysis of cordycepin. The cultivated Cordyceps militaris on various media contained 1~14 /g of cordycepin, 0.65~1.08% of thiamine, 0.86~7.17% of riboflavin, and 3.01~5.26% of niacin. The content of mineral components varied on categories, especially contained 500~3500% of potassium as a major mineral. Cordycepin, niacin and potassium were found much higher in the fruiting cultivated with soy power media (gold 10) than other media.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.104-114
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• 2014

The variation of acidity, conductivity, and ion components in precipitation depending on the dominant wind direction was investigated from January, 2009 to December 2009 in Busan, Korea. Both southwesterly and northeasterly winds were dominant in Busan area. The volume-weighted mean acidity showed pH 7, and the high conductivity indicated 200 ${\mu}scm^{-1}$ in westerly wind. The volume-weighted mean equivalent concentration showed higher value of $K^+$ and $Cl^-$ in all wind directions. The composition ratio of $NO{_3}^-/SO{_4}^{2-}$ showed over 3 in northerly wind. The neutralization factors have been found to have higher value for potassium ion in northeasterly, easterly, southwesterly, and westerly winds compared with different wind directions, which indicated significant neutralization of acidic components over the region by potassium. Also, the concentration of sea salt has been found over 800 ${\mu}sm^{-3}$ in northeasterly and southwesterly winds. Air masses passing through Manchuria, Inner Mongolia plateau, China, and Russia in spring, autumn, and winter covered Busan, Korea in northerly, westerly, and northwesterly winds. However, air masses passing through the ocean in summer covered Busan, Korea in easterly, northeasterly, and southwesterly winds. Therefore, the variation of acidity, conductivity, and ionic components contained in precipitation shows each seasonal characteristics with prevailing wind systems between the continental and coastal area in Busan, Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.3
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• pp.25-32
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• 2022

To understand the distribution characteristics of PM_2.5 concentration in the Saemangeum Reclamation Area and nearby areas, three points of the background area, the occurrence area, and the affected area were selected and samples were collected for each season. The chemical composition was determined. As a result of analyzing the chemical composition contained in PM_2.5, NO₃^- (7.2 ㎍/m³), SO₄^2- (4.3 ㎍/m³), NH₄+ (4.3 ㎍/m³), OC (2.5 ㎍/m³), Si (1.3 ㎍/m³) m³) and EC (0.5 ㎍/m³) seemed to be the main components, and NO₃-, SO₄^2-, NH₄⁺, which are components that form secondary particles, occupied a large proportion. The composition ratio of PM_2.5 was investigated in the order of ion component (56.8%) > Unknown (27.4%) > carbon component (11.8%) > heavy metal component (4.0%). During the PM_2.5 high concentration case days, the ionic component accounted for 90.7% during atmospheric stagnation cases, whereas the chemical composition ratio was in the order of ionic component (51.7%) > heavy metal component (41.5%) > carbon component (6.8%) during yellow dust cases. It was found that the characteristic of PM_2.5 in the Saemangeum reclaimed land and surrounding areas is mainly influenced by outside (domestic and overseas) throughout the year. Ion components accounted for the largest portion of PM_2.5 components in this area, but there were few sources of SOx and NOx emission in the Seamangeum area, which are precursors for secondary particle formation. Therefore, it is judged that most of these are generated and influenced as a secondary reaction in the atmosphere from the outside.