• Environmental Engineering Research
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• 제7권2호
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• pp.93-101
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• 2002

The seasonal patterns of dissolved organic matter (DOM) in Lake Kasumigaura, a shallow, eutrophic lake, and serveral DOM sources in its catchment area were investigated. DOM was fractionated using three resin adsorbents into classes: aquatic humic substances (AHS=humic acid+fulvic acid), hydrophobic neutrals (HoN), hydrophilic acids (HiA), bases (BaS) and hydrophilic neutrals (HiN). The DOM produced significantly different fraction distributions depending on the origin of sample. AHS and HiA prevailed over AHS in the lake while AHS and HiA existed at almost the same concentration levels in the rivers. AHS seems to be a more dominant component in rever water than lake water. The dominance of organic acids was also observed in the DOM sources: forest stream (FS), plowed field percolate (PFP), domestic sewage (DS) and sewage treatment plant effluent (STPE).

• 한국수소및신에너지학회논문집
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• 제19권2호
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• pp.111-117
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• 2008

A Bunsen reaction section is a primary stage of Sulfur-iodine thermochemical hydrogen production cycle. This section is important, because it decides the efficiency of next stages. In order to produce hydrogen very efficiently, the characteristics of Bunsen reaction were investigated via two experimental methods. The one is a phase separation of $H_2SO_4-HI-H_2O-I_2$ mixture system, and the other is a direct Bunsen reaction. The characteristics of each method were investigated and compared. As the result of this study, the amount of HI and $I_2$ in $H_2SO_4$ phase via Bunsen reaction was more decreased than that via $H_2SO_4-HI-H_2O-I_2$ mixture system with increasing $I_2$ concentration. However, the amount of $H_2SO_4$ in $HI_x$ phase via Bunsen reaction was remarkably increased with increasing $I_2$ concentration, while that via $H_2SO_4-HI-H_2O-I_2$ mixture system was decreased. On the other hand, the range of initial composition which is able to separate into two liquid phases without $I_2$ solidification was almost alike.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.28-36
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• 2015

Simultaneous mobility reduction of explosives and heavy metals in an operational range by monopotassium phosphate (MKP) and bentonite spreading technology was investigated. Potassium ion and phosphate ion in MKP act as explosives sorption enhancer and insoluble heavy metal phosphate formation, respectively, while bentonite acts as the explosives adsorbent. Then, the decrease in surface water concentration of the pollutants and resulting risk reduction for local residents of the operational range, by MKP/bentonite application was estimated. Under untreated scenario, the noncancer hazard index (HI) exceeded unity on February, July and August, mainly due to 2,4,6-trinitrotoluene (TNT); however, MKP/bentonite treatment was expected to lower the noncancer hazard index by decreasing the surface water concentration of explosives and heavy metals (especially TNT). For example, on July, estimated surface water concentration and HI of TNT were 0.01 mg/L and 1.1, respectively, meanwhile the sorption coefficient of TNT was 3.9 mg¹⁻ⁿkg⁻¹Lⁿ. However, by MKP/bentonite treatment, the TNT sorption coefficient increased to 113.8 mg¹⁻ⁿkg⁻¹Lⁿ and the surface water concentration and HI decreased to about 0.002 mg/L and 0.2, respectively. Based on the result, it can be concluded that MKP/bentonite spreading is a benign technology that can mitigate the risk posed by the pollutants migration from operational ranges.

• 대한수의학회지
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• 제42권1호
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• pp.73-80
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• 2002

An enzyme-linked immunosorbent assay (ELISA) using purified hemagglutinin of swine influenza virus (H1N1) as antigen was developed for detection of antibody to avian influenza virus (AIV). The sensitivity and specificity of a developed and commercial available ELISA kits were compared with those of agar gel precipitation (AGP) test and hemagglutination inhibition (HI) test using sera collected from chickens under condition of field exposure. The concentration of antigen, serum dilution and concentration of enzyme-conjugated secondary antibody in developed ELISA (S-ELISA) were 0.5ug/100ul, 1:200 and 0.03ug/100ul, respectively. The correlation coefficients between S-ELISA and commercial ELISA and HI titers were 0.419 and 0.533, respectively. A significant correlation (p < 0.01) was not found between HI and ELISA titers. The S-ELISA was found to be as more sensitive and specific than the AGP test, showing 86.8% sensitivity and 85.3% specificity. It is suggested that the ELISA using the SIV as antigen may be useful method as an investigating tool for AIV serological surveillance.

• Molecules and Cells
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• 제26권2호
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• pp.206-211
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• 2008

HI0381 of Haemophilus influenzae was investigated by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. HI0381 is a 153-residue peptidoglycan-associated outer membrane lipoprotein, and a part of the larger Tol/Pal network. Here, we report its backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignments, and secondary structure predictions. About 97% of all of the $^1HN$, $^{15}N$, $^{13}CO$, $^{13}C{\alpha}$, and $^{13}C{\beta}$ resonances covering 131 non-proline residues of the 134 residue, mature protein, were clarified by sequential and specific assignments. CSI and TALOS analyses revealed that HI0381 contains five ${\alpha}$-helices and five ${\beta}$-strands. To characterize the structure of HI0381, the effects of pH and salt concentration were investigated by CD. In addition, the structural changes occurring when HI0381 was in a membranous environment were investigated by comparing its HSQC spectra and CD data in buffer and in DPC micelles; the results showed that helix ${\alpha}4$ and strand ${\beta}4$ became aligned with the membrane. We conclude that the conformation of HI0381 is affected by the membrane environment, implying that its folded state is directly related to its function.

• 대한화학회지
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• 제34권6호
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• pp.582-592
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• 1990

양이온 교환체 (LC-18 coated with $C_{20}H_{41}SO_4^-$)에서 희토류원소-$\alpha$HiBA 착물계의 머무름 거동을 연구하였다. [Na$^+$] 및 [$\alpha$-HiBA]의 등용매 또는 기울기 용리에 따른 희토류원소의 머무름을 나타내는 관계식을 이온 교환 평형식으로부터 유도하였다. [$Na+$] 및 [$\alpha$-HiBA]의 등용매 용리에 따른 크기성질(k')의 관계인 log k' vs log [$Na^+$] 및 log k' vs log [$\alpha$-HiBA]의 직선의 기울기 값에 대한 실험값과 계산값을 비교한 결과 서로 일치하였다. 위의 관계식으로부터 비선형 최소자승법으로 각 개별 착물들의 크기성질($k'_{Ln}^{3+}, k'_{LnL}^{2+}, k'{LnL2+}) 및 착물의 안정도 상수(${\beta}_1$, ${\beta}_2$, ${\beta}_3$)를 각각 구하였다. 희토류원소들의 크기성질(k')에 대한 실험값과 계산값의 상관계수가 0.9996보다 좋은 결과를 나타내었다.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.13-21
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• 2016

The Sulfur-Iodine thermochemical hydrogen production process (SI process) consists of the Bunsen reaction section, the $H_2SO_4$ decomposition section, and the HI decomposition section. The $HI_x$ solution ($I_2-HI-H_2O$) could be recycled to Bunsen reaction section from the HI decomposition section in the operation of the integrated SI process. The phase separation characteristic of the Bunsen reaction using the $HI_x$ solution was similar to that of $I_2-H_2O-SO_2$ system. On the other hands, the amount of produced $H_2SO_4$ phase was small. To investigate the effects of $SO_2$ solubility on Bunsen reaction, the continuous Bunsen reaction was performed at variation of the amounts of $SO_2$ gas. Also, it was carried out to make sure of the effects of partial pressure of $SO_2$ in the condition of 3bar of $SO_2-O_2$ atmosphere. As the results, the characteristic of Bunsen reaction was improved with increasing the amounts and solubility of $SO_2$ gas. The concentration of Bunsen products was changed by reverse Bunsen reaction and evaporation of HI after 12 h.

• 한국화재소방학회논문지
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• 제12권4호
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• pp.13-19
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• 1998

Hartman식 분진폭발 장치를 이용하여 두 총회 카본블랙 High Black 10과 50L의 업도분포별, 농도별 그리고 동일한 입도분포에서 비표면적과 표면 기능기의 양에 따흔 이뜰 시료의 분진폭발 확 률, 분진폭발 압력 통을 조사함i으로서 카본블랙 분친의 위험성을 평가하고자 하였다\ulcorner 이에 카본블 랙의 비표면적을 측정하고 표면에 존재하는 기놓기룹 정량함으로서 휘발분이나 비표면적이 싱-대 적 으로 넓 몫 Hi - Black 50L의 경 우 f-lilongleftarrowBlack 10에 비 해 상대 적 으로 폭발 획 룹과 폭발 압력 이 크게 나타났으며, 최대폭발압력은 돼- Black 50L의 입도분포 230/270 mesh, 시료농도 0.9 mg/em에서 약 6 6.0 kg/em'으로 나타났다.

• Corrosion Science and Technology
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• 제3권5호
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• pp.194-197
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• 2004

The corrosion resistance of several kind of ME (Metal Evaporated) tape has been investigated both in mild sulfuric acid solution and NaCl solution by electrochemical impedance spectroscopy. It was found that the degradation of ME tapes was accelerated with increasing the concentration of sulfuric acid. There was no significant change in corrosion resistance when the concentration of NaCl was under 3.5 wt%. However, the impedance value decreased when the concentration of NaCl was up to 10 wt%. The degradation of backside of ME tapes was also investigated by AC impedance measurements. The results showed that the impedance behavior of backside plastic film changed with the concentration of sulfuric acid even at the beginning of immersion, implying the changing of the permeability for the backside of ME tapes. It was also found that the corrosion resistance of DVC (Digital Video Cassette) ME tape was better that that of Hi-8mm ME tapes in sulfuric acid solutions. Also, the backside of DVC ME tape showed better water resistance than that of Hi8 ME tapes.

• KSBB Journal
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• 제13권3호
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• pp.272-278
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• 1998

Cell recovery from high cell density broths of Alcaligenes eutrophus by pretreatment with aluminum-based coagulants such as aluminum sulfate, polyaluminum hydrooxide chloride silicate (PACS), and polyaluminum hydrooxide chloride (Hi-PAX) was carried out. Cells coagulated with coagulants could be successfully recovered above 95-99% by centrifugation or filtration. The optimum initial pH of fermentation broths for cell recovery was in the range of 10 to 12. Optimum coagulants dosage for cell recovery increased with increasing of cell concentrations (21-160 g/L). The optimum coagulant dosages to recover cells with more than 95% cell recovery by centrifugation for the cell concentrations ranged 21-160 g/L were as follows: aluminum sulfate, 416-1708 mg Al/L; PACS, 211-826 mg Al/L; Hi-PAX, 320-960 mg Al/L. At optimum conditions for the coagulation of cells, centrifugal forces for 95% of cell recovery were dependent on the cell concentration. The centrifugal forces at 82 g/L and 160 g/L of cell concentration were only 45${\times}$g and 1600${\times}$g, respectively.