• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.5
• /
• pp.246-254
• /
• 2017

Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

• Microbiology and Biotechnology Letters
• /
• v.26 no.2
• /
• pp.122-129
• /
• 1998

It were reported that antifungal mechanism of Enterobacter cloacae is a volatile ammonia that produced by the strain in soil, and the production of ammonia is related to the bacterial urease activity. A powerful bacterium SH14 against soil-borne pathogen Fusarium solani, which cause root rot of many important crops, was selected from a ginseng pathogen suppressive soil. The strain SH14 was identified as Bacillus subtilis by cultural, biochemical, morphological method, and $API^{circledR}$ test. From several in vitro tests, the antifungal substance that is produced from B. subtilis SH14 was revealed as heat-stable and low-molecular weight antibiotic substance. In order to construct the multifunctional biocontrol agent, the urease gene of Bacillus pasteurii which can produce pathogenes-suppressive ammonia transferred into antifungal bacterium. First, a partial BamH I digestion fragment of plasmid pBU11 containing the alkalophilic B. pasteurii l1859 urease gene was inserted into the BamH I site of pEB203 and expressed in Escherichia coli JM109. The recombinant plasmid was designated as pGU366. The plasmid pGU366 containing urease gene was introduced into the B. subtilis SH14 with PEG-induced protoplast transformation (PIP) method. The urease gene was very stably expressed in the transformant of B. subtilis SH14. Also, the optimal conditions for transformation were established and the highest transformation frequency was obtained by treatment of lysozyme for 90 min, and then addition of 1.5 ${mu}g$/ml DNA and 40% PEG4000. From the in vitro antifungal test against F. solani, antifungal activity of B. subtilis SH14(pGu366) containing urease gene was much higher than that of the host strain. Genetical development of B. subtilis SH14 by transfer of urease gene can be responsible for enhanced biocontrol efficacy with its antibiotic action.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.286-291
• /
• 2011

Hypoxia is a common condition found in a wide range of solid tumors and is often associated with metastasis and poor clinical outcomes. In the present study, we found that HIF-$1{\alpha}$ was induced by cobalt chloride (500 ${\mu}M$) treatment on human lung cancer cells, A549 and H460, for 24 hr. However, cobalt chloride (500 ${\mu}M$) did not affect cell proliferation of A549 and H460 in 48 hr. Cobalt chloride (500 ${\mu}M$) additionally induced epithelial-to-mesenchymal-like transition (EMT) such as reduced E-cadherin expression and increased ${\alpha}$-SMA expression. These results were confirmed by immunofluorecence experiment in H460 cells. E-cadherin was localized on the outer cell membrane. However, when the cells were treated with 500 ${\mu}M$ cobalt chloride for 24 hr, diffuse E-cadherin staining was observed, characteristic of a migratory mesenchymal phenotype. We also found that cobalt chloride induced integrin ${\beta}3$ expression and FAK phosphorylation in human lung cancer cells using western blotting and FACS anlaysis. Our data suggest that integrin ${\beta}3$-induced FAK phosphorylation may be developed into target molecules for blocking tumor metastasis.

• Radiation Oncology Journal
• /
• v.7 no.1
• /
• pp.85-92
• /
• 1989

Dosimerty based on electron spin resonance (ESR) analysis of radiation induced free radicals in amino acids is relevant to biological dosimetry applications. Alanine detectors are without walls and are tissue equivalent. Therefore, alanine ESR dosimetry looks promising for use in the therapy level. The dose range of the alanine/ESR dosimetry system can be extended down to 1 Gy. In water phantom the absorbed dose of electrons generated by a medical linear accelerator of different initial energies $(6\~21MeV)$ and therapeutic dose levels (1~60 Gy) was measured. Furthermore, depth dose measurements carried out with alanine dosimeters were compared with ionization chamber measurements. As the results, the measured absorbed doses for shallow depth of initial electron energies above 15 MeV were higher by$2\~5\%$ than those calculated by nominal energy $C_E$ factors. This seems to be caused by low energy scattered beams generated from the scattering foil and electron cones of beam projecting device in medical linear accelerator.

• Applied Biological Chemistry
• /
• v.20 no.2
• /
• pp.182-187
• /
• 1977

This investigation was to determine the changes in the trypsin inhibitor activity(TIA) and electrophoresis patterns of the soybean cotyledon and axis during germination. The TIA of the cotyledon decreased slightly and that of the axis decreased rapidly to 50% activivity after 7 day germination. At the 2nd, 3rd and 4th day's germination the TIA of the defatted dry axis was higher than that of cotyledon. However, the TIA of the fresh cotyledon was lower than that of the axis, due to its higher moisture content. Results from the electrophoretic studies showed that band 1 (polymer, 15S etc.), 2(11S), and 3(7S) whichare the major reserve proteins of soybean were decreased consid erably in cotyledon and axis and the fragments with Rm values between 0.5 and 1.0 were increased and band 5 showed up during germination. The band 4 of the cotyledon and band 6 of axis were not changed during germination. Generally speaking, the TIA and thereserve protein decreased as germination proceed.

• Journal of Satellite, Information and Communications
• /
• v.10 no.2
• /
• pp.90-94
• /
• 2015

We stuidied liauid crystal alignment treatment using solution process for making thin oxide layer in liquid crystal display. It is the one of very effient and popular process in making thin oxide layer in electronical industrial fields. Particularly, this process has highly potential value in liquid crystal display industrial fields because it cause automatically induced alignment process without tranditional alignment process in liquid crystal alignment process. We made several different kinds of mol density solutions using strontium oxide solution. And those solutions were treated for solidification layers using annealing process for 2 hours. And we stuided pretilt angle properties of these alignment layers of strontium oxide for clarifying the relationship of liquid crystal molecules and thin strontium oxide layer. And we also tested the existence of strontium oxide thin layer on substrate using XPS measurement. We expected the hig gain of electro-optical properties in liquid crystal display using strontium oxide thin layer because it has high K property material than the other metal-based oxide layers. In this results, we measured 1.447 to 1.613 thresholds volts as 0.1 mol to 0.4 mol density in 0.1 mol density steps. This is significant better characteristics than conventional liquid crystal display as higher than 1.85 thresholds volts. And it make possible to making next-generation liquid crystal display which present low-power consumption and wide gray scale in liquid crystal display.

• Journal of Korean Society of Archives and Records Management
• /
• v.1 no.1
• /
• pp.177-200
• /
• 2001

The causes which affects the deterioation of paper arc paper structure, papermaking process, temperature and rative humidity, light and biological agents. Paper made from cllulose fibers by the wood and the nonwood, This paper structure is further hydrolyzed by acidic additive such as the sizing agents during the manufacturing process. These additives leave residual acids in the paper, which break the cellulose clown to simper molecules. The results is weak paper and bas caused most of the damage to book. This study was carried out to investigate the presevation and the deacidification for the permanenece by the book. The deacidification and the chemical agents aims to nutralized the aicd in paper and add alkaline to it as a buffer to withstand future acid attacks. By applying the system to the acid paper with a pH of 4.5 neutralized a pH of 8.5. The expected of alkaline reserved paper extend about 2times and 3times than acidic paper.

• Membrane Journal
• /
• v.28 no.3
• /
• pp.180-186
• /
• 2018

The nano-composite membranes were prepared onto the polyvinylidene fluoride (PVDF) hollow fiber membranes through twice dip-coating known layer-by-layer method. For the first coating, poly(vinylsulfonic acid, sodium salt)(PVSA) and Poly(styrene sulfonic acid)(PSSA) were used with varying the concentration and ionic strength (IS) and the poly(ethyleneimine)(PEI) as the second coating material was fixed at 10,000 ppm and IS = 0.3. To characterize the prepared nano-composite membranes, the permeabilities and rejection ratio were measured for each 100 ppm NaCl, $CaSO_4$, $MgCl_2$, and 25 ppm MO aqueous solution. The rejections were increased as the concentrations of coating materials increased. And it was confirmed that the salt rejections for PSSA as the coating material were higher than for PVSA. Typically, the permeability, 1.848 LMH and the rejection for MO 76.3% were obtained at the coating conditions of PSSA 30,000 ppm and I.S = 1.0.

• Applied Chemistry for Engineering
• /
• v.31 no.5
• /
• pp.475-480
• /
• 2020

Chelates synthesized with Cu(II) ion and lactic acid or chitosan were applied to the hydrolysis of organophosphate simulant, DFP (diisopropyl fluorophosphate). Under the homogeneous reaction condition, Cu(II)-lactic acid chelate hydrolyzed DFP with the half life time of 37.1 min. Cu(II)-LMWS chitosan chelate was synthesized with 1 kDa molecular weight of chitosan, which showed low solubility, and then crystallized. The half life time for hydrolyzing DFP using Cu(II)-LMWS chitosan was 32.9 h indicating that the reaction rate is enhanced as much as 16 times more than that of using 18 kDa chitosan-Cu(II) complex. Under the homogeneous reaction condition, the half life time of Cu(II)-LMWS chitosan was 8.75 h. Therefore, we found out that the solubility of Cu(II)-LMWS chitosan makes the difference in the reaction rate as much as 4 times.

• Food Engineering Progress
• /
• v.21 no.2
• /
• pp.138-142
• /
• 2017

This study investigated the possible use of enzymatically hydrolyzed isolated soy protein (eHISP) to enhance the intensity of salty taste. The sodium chloride content of eHISP is 69.5 g/L. Yellowness (b) increased, and lightness (L) and redness (a) decreased with increasing eHISP concentration in sample solution. Also, perceived salty intensity of eHISP solution increased in sample solution with increasing added amount of eHISP with same NaCl concentration. The intensity of the salty taste was enhanced by 2-39% as the eHISP was added. The results suggest that it may be possible to reduce the content of sodium chloride in foods by enhancing the salty taste with eHISP.