• Journal of Korean Society for Atmospheric Environment
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• 제22권E1호
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• pp.27-34
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• 2006

Although the importance of size-resolved raindrops study has been known, it has not been popularized up to the present. In the present study, an attempt was made to generalize the size-resolved raindrops study by a combination of the frozen raindrop collection method and a commercially available high-performance capillary electrophoresis (HPCE). Samplings were carried out at Kyoto, Japan in October 2002. The inorganic ions (chloride, nitrate, sulphate, calcium, ammonium, sodium, magnesium, potassium) in size classified raindrop samples were successfully analyzed by HPCE with good repeatability. To assure the accuracy and precision of HPCE data, t-test was conducted with paired analytical data, which were experimentally constructed by analyzing standard solutions with HPCE and IC, respectively. T-test showed that there is no notable difference between the concentrations determined by the two analytical methods. Every ionic concentration in both cation and anion was found to be strong raindrop size dependence. Though there was slight increase of sodium and sulphate concentrations between 0.85 mm and 1.15 mm raindrop radius, it showed a strong decrease for every ionic component with increasing droplet radius. The combination of the frozen raindrop collection method and a commercially available HPCE can meet the need of size-resolved raindrops study.

• Journal of Electrochemical Science and Technology
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• 제2권1호
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• pp.8-13
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• 2011

Interfacial compatibility between the Si-Cu electrode and diluted ionic liquid electrolyte containing 50 vol.% of 1M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide (MPP-TFSI) and 50 vol.% dimethyl carbonate (DMC) in a lithium cell and dilution effect on surface chemistry are examined. ex-situ ATR FTIR analysis results reveal that the surface of the Si-Cu electrode cycled in the diluted ionic liquid electrolyte is effectively passivated with the SEI layer mainly composed of carboxylate salts-containing polymeric compounds produced by the decomposition of DMC. Surface species by the decomposition of TFSI anion and MPP cation are found to be relatively in a very low concentration level. Passivation of electrode surface with the SEI species contributes to protect from further interfacial reactions and to preserve the electrode structure over 200 cycles, delivering discharge capacity of > 1670 $mAhg^{-1}$ and capacity retention of 88% of maximum discharge capacity.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3687-3691
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• 2011

Ion exchange experiments of molybdenum(VI) from strong HCl and $H_2SO_4$ solution have been done to investigate the existence of anionic complexes. The concentration of HCl and $H_2SO_4$was changed from 1 to 9 M. From the data on the complex formation of molybdenum in aqueous solution, a new distribution diagram of Mo(VI) was constructed in the pH range from zero to 10. AG 1 X-8, an anion exchange resin, and Diphonix, a cation exchange resin were used in the loading experiments. Ion exchange results indicate that anionic complexes of Mo(VI) begins to form from 3 M HCl and 1 M $H_2SO_4$ solution and the tendency to form anionic complexes is stronger in HCl than in $H_2SO_4$ solution. Our results can be utilized in the analysis of Mo(VI) in strong acid solution and in the design of a process to separate Mo(VI).

• The Korean Journal of Physiology
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• 제28권2호
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• pp.143-150
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• 1994

The whole-cell mode of the patch clamp technique was used to study $Ca^{2+}-activated\;Cl^-\;current$ $(I_{Cl_{Ca}})$ in gastric antral myocytes. Extracellular application of caffeine evoked $Ca^{2+}-activated\;current$. In order to isolate the chloride current from background current, all known systems were blocked with specific blockers. The current-voltage relationship of caffeine-induced current showed outward rectification and it reversed at around $E_{Cl^-}$. The shift of reversal potential upon the alteration of external and internal chloride concentrations was well fitted with results which were calculated by the Nernst equation. Extracellular addition of N-phenylanthranilic acid and niflumic acid which are known anion channel blockers abolished the caffeine induced current. Intracellular application of a high concentration of EGTA also abolished this current. Application of c-AMP, c-GMP, heparin, or $AIF^-_4$ made no remarkable changes to this current. Sodium replacement with the impermeable cation N-methylglucamine or with $Cd^{2+}$ rarely affected this current. From the above results it is suggested that the caffeine induced current was a $Cl^-$ current and it was activated by intracellular $Ca^{2+}$.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.133-142
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• 2011

A total of 247 samples were collected from groundwater being used for drinking-water supply, and hydrogeochemistry and radionuclide analysis were performed. In-situ analysis of groundwaters resulted in ranges of $13.7{\sim}25.1^{\circ}C$ for temperature, 5.9~8.5 for pH, 33~591 mV for Eh, $66{\sim}820{\mu}S/cm$ for EC, and 0.2~9.4 mg/L for DO. Major cation and anion concentrations of groundwaters were in ranges of 0.5~227.6 for Na, 1.0~279.3 for Ca, 0.0~9.3 for K, 0.1~100.1 for Mg, 0.0~3.3 for F, 0.9~779.1 for Cl, 0.3~120.4 for $SO_4$, 0.0~27.4 for $NO_3$-N, and 6~372 mg/L for $HCO_3$. Uranium-238 and radon-222 concentrations were detected in ranges of N.D-$131.1{\mu}g/L$ and 18-15,953 pCi/L, respectively. In case of some groundwaters exceeding USEPA MCL level ($30{\mu}g/L$) for uranium concentration, their pH ranged from 6.8 to 8.0 and Eh showed a relatively low value(86~199 mV) compared to other areas. Most groundwaters belonged to Ca-(Na)-$HCO_3$ type, and groundwaters of metamorphic rock exhibited the highest concentration of Na, Mg, Ca, Cl, $NO_3$-N, U, and those of plutonic rock showed the highest concentration of $HCO_3$, and Rn. Uranium and fluoride from granite areas did not show any correlation. However, uranium and bicarbonate displayed a positive relation of some areas in plutonic rocks($R^2$=0.3896).

• 생명과학회지
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• 제23권3호
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• pp.377-382
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• 2013

이 연구에서는 동충하초, 영지, 상황 버섯 복합물의 항산화 효과를 평가하였다. 3가지 버섯을 각각 70% 에탄올 추출하여 80:10:10의 비율로 혼합하여 평가를 실시하였다. DPPH radical을 이용한 전자공여능 측정에서는 버섯 복합물이 500 ${\mu}g/ml$의 농도에서 66%의 효과를 나타내었고, ABTS radical cation decolorization 측정은 50 ${\mu}g/ml$에서 73%, 500 ${\mu}g/ml$에서 대조군인 BHA와 유사한 효과를 나타내었다. Superoxide anion radical 소거능 측정은 버섯 복합물 10 ${\mu}g/ml$에서 41%로 대조군인 BHA에 비해 3배 이상의 높은 효과가 있었고, 50 ${\mu}g/ml$, 100 ${\mu}g/ml$에서도 BHA 보다 효과가 높았으나, 500 ${\mu}g/ml$에서는 낮은 효과를 나타내었다. Lipid oxidation 측정결과 $Cu^{2+}$군보다 $Fe^{2+}$군이 지방 산패 억제능이 뛰어났다. SOD 유사활성능 측정은 500 ${\mu}g/ml$에서 13%의 낮은 효과를 나타내었다. 이 결과, 버섯 복합물의 항산화 효과가 아주 우수했으므로, 항산화 소재로서의 가능성을 확인할 수 있었다.

• 한국대기환경학회지
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• 제14권5호
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• pp.479-490
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• 1998

The concentrations of ten inorganic (sodium, chloride, sulfate, ammonia, etc.) and three organic (acetate, formate, and MSA) ions associated with airborne particulate matter were measured from Cheju Island, Korea during the three field intensive campaigns conducted in (1) Sept./oct. 1997 (fall), (2) Dec. 1997 (winter), and (3) April 1998 (spring). The results of our measurements indicated that the concentration levels of most ionic species were decreasing significantly across the three experimental periods. The patterns of concentration reduction were clear as the sum of all cation and anion species changed dramatically across those periods such as 294> 144 > 65 and 193 >96>74 nequiv/m3, respectively. The changes were best explained in terms of the wind rose patterns of the study site. Since our sampling spot is located on the western-end point of Cheju Island, it is likely to reflect the effects of diverse sources such as natural, marine processes during NW and local non-maritime ones during SE winds. .Hence, the periodical changes in ionic concentrations may be accounted for by the comparable changes in wind direction. To further investigate environmental characteristics of these ionic components, correlation analysis was conducted not only between meteorological and ion data but between different ion-pairs. The results of these analyses confirm that the concentration levels of ionic species are strongly affected by wind speed and temperature and that there are certain patterns between ion species to which such effects apply. In light of the significance of the wind rose patterns in the area, we further extended these analyses into four data groups that were divided on the basis of wind direction. The results of these analyses showed that the strength of correlations between important pairs (e.g.:. between windspeed and most of major inorganic species including sodium and chloride) can be ranked on the distribution of major ions are very diverse, depending on data grouping scheme for such analysis. The results of this study thus suggest that environmental behavior of chemical components be analyzed in various respects, rather than simple standard, especially if measurements are made in complex environmental condition under which both natural and anthropogenic effects are competing each other.

• 멤브레인
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• 제25권5호
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• pp.447-455
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• 2015

본 연구에서는 Polysulfone (PSf), Polyetherimide (PEI)를 각각 비율을 달리하여 아민화하였고, Polyether ether ketone (PEEK)을 설폰화하였다. 합성한 두 이온교환고분자를 더블캐스팅방법으로 SPEEK (sulfonated PEEK)/APSf (aminated PSf) 및 SPEEK/APEI (aminated PEI) 바이폴라막을 제조하였다. 각각의 막 표면을 불소화하고, 아민화 비율에 따라 차아염소산나트륨발생량을 비교하였다. 아민화 비율이 증가할수록 차아염소산나트륨 발생 농도 또한 증가하였다. SPEEK/APSf 3 : 1 막의 경우 불소화 전의 차아염소산나트륨 농도와 총 운전시간은 61.0 ppm, 220 min이고, 불소화한 막의 경우 58.6 ppm, 570 min이다. 또한 SPEEK/APEI 3 : 1 막에서 역시 불소화 전후의 차아염소산나트륨 농도는 각각 60.1 ppm, 58.3 ppm이고, 총 운전시간은 150 min에서 440 min으로 내구성이 크게 향상되었다. 따라서 표면 불소화가 막의 내구성에 중요한 역할을 한다고 사료된다.

• 대한화학회지
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• 제43권6호
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• pp.651-655
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• 1999

뱃치법을 이용하여 음이온 교환수지(Amberlite IRA 400, $Cl^-$형)에 Xylenol Orange를 결합시킨 수지를 얻었다. 이 수지는 0.1 M 정도의 무기산에서 안정하였으며, Xylenol Orange가 결합된 Amberlite lRA-400 수지의 금속 이온들에 대한 흡착능을 측정해 본 결과, Fe(lll) 이온의 흡착력이 다른 이온에 비해 컸다. 따라서 Fe(III) 이온을 예비 농축할 수 있었으며 다른 이온으로 부터 분리하는데는 용리액으로 0.1 M sulfosalicylic acid 용액이 사용되었다.

• 한국환경과학회지
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• 제26권6호
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• pp.767-778
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• 2017

This research investigates the characteristics of metallic and ionic elements in $PM_{10}$ and $PM_{2.5}$ on haze day and non-haze day in Busan. $PM_{10}$ concentration on haze day and non-haze day were 85.75 and $33.52{\mu}g/m^3$, respectively, and $PM_{2.5}$ on haze day and non-haze day were 68.24 and $23.86{\mu}g/m^3$, respectively. Contribution rate of total inorganic water-soluble ion to $PM_{10}$ mass on haze day and non haze day were 58.2% and 61.5%, respectively, and contribution rate of total water-soluble ion to $PM_{2.5}$ mass on haze day and non haze day were 58.7% and 64.7%, respectively. Also, contribution rate of secondary ion to $PM_{10}$ mass on haze day and non haze day were 52.1% and 47.5%, respectively, and contribution rate of secondary ion to $PM_{2.5}$ mass on haze day and non haze day were 54.4% and 53.6%, respectively. AC (anion equivalents)/CE (cation equivalents) ratio of $PM_{10}$ mass on haze day and non haze day were 1.09 and 1.0, respectively, and AC/CE ratios of $PM_{2.5}$ mass on haze day and non haze day were 1.12 and 1.04, respectively. Also, SOR (Sulfur Oxidation Ratio) of $PM_{10}$ mass on haze day and non haze day were 0.32 and 0.17, respectively, and SOR of $PM_{2.5}$ on haze day and non haze day were 0.30 and 0.15, respectively. Lastly, NOR (Nitrogen Oxidation Ratio) of $PM_{10}$ on haze day and non haze day were 0.17 and 0.08, respectively, and NOR of $PM_{2.5}$ on haze day and non haze day were 0.13 and 0.06, respectively.