• 한국환경보건학회지
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• 제20권4호
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• pp.1-9
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• 1994

In order to investigate the regional level of air pollutants at Kangwha island situated on the western coast in Korea, the suspended particulate matter samples were collected by using the low volume air sampler on ten interval from March 1992 to February 1993 and the mass concentration of suspended particulate matter (SPM) and the chemical composition of water-soluble major ionic components in SPM samples were measured. During the sampling period, the average concentration of SPM under diameter 10 $\mu$m was found to be 48 $\mu$g/m$^3$ (+ 12). The seasonal concentration of SPM was showed in order of spring>fall>winter>summer. It was considered that higher concentration on spring than other season was affected by the long-range transport of Yellow sand particulate from China continent and lower concentration on summer by the washout and rainout effect of large rainfall. The content of water-soluble component in SPM samples was founded to be about 31% (14.69 $\mu$g/m$^3$) and 65% was unknown or unanalyzed. The content of cationic component showed in order of NH$_4^+$ (44.6%)>Na$^+$ (21.2%)>K$^+$ (14.7%)>Ca$^{2+}$ (13.6%)>Mg$^{2+}$ (5.9 %) and the content of anionic component SO$_4^{2-}$ (62.5%)>NO$_3^-$ (22.3%)>Cl$^-$ (15.2%), respectively. This fact indicates that ammonium and sulfate ion of water-soluble component in SPM sample were dominant in this region. From the chemical composition of water-soluble component, the most of Na$^+$, Mg$^{2+}$ and Cl$^-$ were originated from seawater source but K$^+$, Ca$^{2+}$ and SO$_4^{2-}$ were originated from other non-marine source. The contribution of seasalt to the composition of precipitation was 23%.

• 한국대기환경학회지
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• 제31권1호
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• pp.15-27
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• 2015

The collection of fine particulate matter samples was made at Gosan site of Jeju Island, one of the background sites of Korea, during a year of 2013, and their water-soluble ionic species were analyzed in order to examine the chemical compositions and pollution characteristics. The concentrations of $nss-SO_4{^{2-}}$, $NH_4{^{+}}$, $NO_3{^{-}}$, and $K^+$ had occupied 66.0% of water-soluble ionic species in $PM_{10}$, especially 94.3% in $PM_{2.5}$ fine mode, however the $nss-Ca^{2+}$ and $Na^+$ showed high concentrations in $PM_{10-2.5}$ coarse mode. $NO_3{^-}/nss-SO_4{^{2-}}$ concentration ratios in $PM_{10}$ and $PM_{10-2.5}$ were 0.30 and 0.13, showing less significant effect from automobile and local pollution sources. The sulfate and nitrate compounds were presumed to be long-range transported to Gosan area by the relatively high SOR and NOR values. The trajectory cluster analysis showed the higher concentrations of the major secondary pollutants ($nss-SO_4{^{2-}}$, $NO_3{^{-}}$, $NH_4{^{+}}$) and $nss-Ca^{2+}$ when the air masses had moved from China continent and Korean peninsula into Gosan area.

• 한국대기환경학회지
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• 제22권1호
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• pp.15-24
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• 2006

Precipitation samples were collected at Anmyeon (1997 - 2004), Uljin, and Gosan (1998 ~ 2004), the background area of the Korean Peninsula. These samples were analyzed for the concentration of 9 major ionic components ($F^{-}$,$Cl^{-}$, $NO_{3}^{-}$, $SO_{4}^{2-}$, $Na^{+}$, $NH_{4}^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$) with including a pH and an electric conductivity. Data quality for these samples was verified by ion balance and conductivity balance which are based on GAW manual for precipitation chemistry and the number of valid data at Anmyeon, Uljin, and Gosan is 249, 173, and 188, respectively. During the study period, the precipitation-weighted average pH at Anmyeon, Uljin, and Gosan was found to be 4.81, 4.87 and 4.89, respectively and each annual average pH was showed below pH 5.6 for every site. From the frequency survey on the precipitation acidity, the occurrence rate of acid rain below pH 5.6 is greater than $80\%$ for every site. Particularly, the highest occurrence rate for strong acid rain below pH 4.5 was found at Anmyeon, $32.1\%$, compared with other sites ($10.4\%$ at Uljin, $15.4\%$ at Gosan). That's because acidifying species (nss-$SO_{4}^{2-}$, $NO_{3}^{-}$) are remarkably high concentration at Anmyeon.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.856-862
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• 2013

The photoanode electrode of $TiO_2$ nanotubes (NTs) anchored with ZnS/CdSSe/CdS quantum dots (QDs) was prepared by anodization of Ti metal and successive ionic layer adsorption and reaction (SILAR) procedure. The tuning of the band gap of CdSSe was done with controlled composition of Cd, S, or Se during the SILAR. A ladder-like energy structure suitable for carrier transfer was attained with the photoanode electrode. The power conversion efficiency (PCE) of our solar cell fabricated with the regular array of $TiO_2$ NTs anchored with CdSSe/CdS or CdSe/CdS QDs [i.e., (CdSSe/CdS/$TiO_2NTs$) or (CdSe/CdS/$TiO_2NTs$)] was PCE = 3.49% and 2.81% under the illumination at 100 mW/$cm^2$, respectively. To protect the photocorrosion of our solar cell from the electrolyte and to suppress carrier recombination, ZnS was introduced onto CdSSe/CdS. The PCE of our solar cell with the structure of a photoanode electrode, (ZnS/CdSSe/CdS/$TiO_2$ NTs/Ti) was 4.67% under illumination at 100 mW/$cm^2$.

• Animal cells and systems
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• 제2권4호
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• pp.455-462
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• 1998

A survey was conducted on the inorganic and organic solute patterns of plants in connection with nitrate metabolism according to different light regimes (1.9, 16.0, 91.5 $Wm^{-2}$). Besides measuring in vivo NRA, we also quantitatively analyzed ater-soluble inorganic ions, organic acids, low molecular weight carbohydrates, amino aciss and total N (% DW). Among 4 Carex species, C. pilosa is known as shade-adapted species and the others as half (C. gracilis) to full (C. rostrata & C. distans) light-adapted species. Compared to species adapted to high light intensity, shade-adapted C. pilosa showed reduced productivity under the highest light intensity. In general, nitrate and amino acid levels decreased at higher light intensity, while sugar and organic acid concentrations increased. In C. pilosa osmolality tended to rise with increasing light intensity, while in the other species it tended to fall. Under low light intensity, the drop in soluble carbohydrate contents is osmotically compensated for by an enhanced nitrate concentration. It is concluded that competition between nitrate and $CO_2$reduction for reductants and ATP from photosynthesis may have important ecological consequences for the adaptation of plants to low or high light conditions. Additionally, the patterns of ionic changes due to increased light intensities were essentially the same in all selected species, indicating similar characteristics of heir mineral ion and organic acid metabolism as well as in field-grown Carex species.

• 한국물환경학회지
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• 제31권5호
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• pp.453-459
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• 2015

This paper aims to evaluate the results of acute toxicity testing with Daphnia mag$Na^+$ and Vibrio fischeri and characteristics of ionic substance of treated effluent which contained salt. Acute toxicity with Daphnia mag$Na^+$ and Vibrio fischeri and salinity of 19 samples (4 business categories) were a$Na^+$lysed. Salinity of effluent could explain the fluctuation of toxicity with D. mag$Na^+$ about 66% ~ 91% ($r^2=0.66{\sim}0.91$). The results of acute toxicity testing with V. fischeri of treated effluent (aggregate manufacture facilities) did not indicate toxicity (TU = 0), whereas that of chemical manufacture facilities indicated toxicity. V. fischeri, a candidate test organism, seemed suitable test organism for acute toxicity testing of effluent except high salinity (above 65‰ ~ 70‰) in aggregate manufacture facilities (nonmetalic minerals facilities). The performance of ion composition about treated effluent of surveyed facilities indicated that ion concentration of $Na^+$ (5,740 mg/L) and $Cl^-$ (9,727 mg/L) showed high level among 6 major ions ($Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $SO_4{^{2-}}$, $Cl^-$) in effluent of nonmetalic minerals facilities. In addition, Clion seemed to influence the D. magna survival rather than $Na^+$ ion.

• 전기화학회지
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• 제7권4호
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• pp.189-193
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• 2004

본 연구에서는 POAGA와 TEGDMA로 구성된 반응성 단량체에서 두 단량체 및 개시제의 조성에 따른 겔폴리머전해질전지를 제조하고 전지특성을 평가하였다 POAGA계 겔폴리머전해질은 단량체의 함량이 증가함에 따라 겔화 시간은 감소하였다. POAGA계 겔폴리머전해질은 4.5V까지 전기화학적으로 안정하였으며, 상온 이온전도도는 약 $5.2\times10^{-3}Scm^{-1}$이었다. POAGA계 겔폴리머전해질을 채용한 리튬이온폴리머전지는 반응성 단량체의 함량이 $5.0wt\%$ 및 $7.0wt\%$인 경우에 비하여 $3.0wt\%$인 경우가 고율, 저온 및 사이클 특성이 우수하였다 또한 개시제 함량은 $1.0\~3.0wt\%$ 범위에서는 $1.0wt\%$인 경우가 우수한 전지특성을 나타내었다.

• Corrosion Science and Technology
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• 제6권2호
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• pp.50-55
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• 2007

The smaller size and higher integration of advanced electronic package systems result in severe electrochemical reliability issues in microelectronic packaging due to higher electric field under high temperature and humidity conditions. Under these harsh conditions, electronic components respond to applied voltages by electrochemical ionization of metal and the formation of a filament, which leads to short-circuit failure of an electronic component, which is termed electrochemical migration. This work aims to evaluate electrochemical migration susceptibility of the pure Sn, Sn-3.5Ag, Sn-3.0Ag-0.5Cu solder alloys in $Na_{2}SO_{4}$. The water drop test was performed to understand the failure mechanism in a pad patterned solder alloy. The polarization test and anodic dissolution test were performed, and ionic species and concentration were analyzed. Ag and Cu additions increased the time to failure of Pb-free solder in 0.001 wt% $Na_{2}SO_{4}$ solution at room temperature and the dendrite was mainly composed of Sn regardless of the solders. In the case of SnAg solders, when Ag and Cu added to the solders, Ag and Cu improved the passivation behavior and pitting corrosion resistance and formed inert intermetallic compounds and thus the dissolution of Ag and Cu was suppressed; only Sn was dissolved. If ionic species is mainly Sn ion, dissolution content than cathodic deposition efficiency will affect the composition of the dendrite. Therefore, Ag and Cu additions improve the electrochemical migration resistance of SnAg and SnAgCu solders.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권4호
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• pp.98-105
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• 2020

In this study, the concentrations of some of the important ionic contaminants in groundwaters of national monitoring network in Korea were identified, and their correlation to nitrate concentration was investigated. Approximately 80% of the groundwater samples were found to be as Ca2+-(Cl-+NO3-) type groundwater with the concentration ranges [minimum to maximum values, median (mg/L)] of Ca2+[0.1~228.2, 19.7], Mg2+[0.1~53.2, 5.1], K+[0.1~50.8, 1.9], Na+[1.5~130.5, 18.1], NO3--N[0.1~73.4, 9.3], NH4+-N[0.0~53.9, 0.3], Cl-[3.1~482.6, 24.0], and SO42-[2.8~101.6, 7.0]. The prevalence of Ca2+-(Cl-+NO3-) type suggest that the composition of groundwaters were greatly influcenced by chemical fertilizers and animal manure, Correlation analyses indicated threre was positive correlation between NO3--N concentration and ionic species including Cl-, Ca2+, Mg2+, and Na+. In particular, the correlation was strongest for Cl- and NO3--N, suggesting that groundwaters largely impacted by agricultural and livestock breeding activities tend to contain high levels of Cl-.

• 한국토양비료학회지
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• 제29권4호
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• pp.389-395
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• 1996

시설재배지내(施設栽培地內)에서 사용하고 있는 지하수질(地下水質) 현황을 파악하기 위하여 경기남부(용인, 화성, 평택)의 50개 농가를 대상으로 한발기(旱魃期) 및 중간기(中間期)(2월 및 5월)와 강우기(降雨期)(9월)에 지하수를 채취하여 화학분석(化學分析)을 실시하고 각 요인별(要因別)로 검토하여 얻어진 내용을 요약하면 다음과 같다. 1. 지하수 깊이에 따른 $NO_3-N$ 함량은 지하수 6-10m 깊이에서 높았고 지형별(地形別)로는 내륙평탄지(內陸平坦地), 곡간지(谷間地) 및 선상지(扇狀地), 산록경사지(山麓傾斜池)보다 하성평탄지(河成平坦地) 중(中) 하천변지(河川邊地)에시 높았다. 2. 경작년수(耕作年數)가 증가할수록 지하수중 $NO_3-N$ 및 $SO_4{^2}$ 함량은 높아지는 경향을 보였다. 3. 지하수의 음(陰)이온/양(陽)이온 총당량(總當量) 비율은 하성평탄지(河成平坦地)중 하천변지(河川邊地)에서 높았고 지하수 깊이가 깊을수록 낮아지는 경향이었다. 4. 지하수중 $NO_3-N$은 pH와 부의 상관을 보였고 $SO_4{^{2-}}$, $Cl^-$, $K^+$, $Ca^{2+}$ 및 $Mg^{2+}$와는 고도의 정의 상관을 보였다.