• Korean Journal of Food Science and Technology
• /
• v.22 no.3
• /
• pp.350-356
• /
• 1990

Functional properties such as nitrogen solubility, emulsifying property, foaming property, and water and oil absorption of sesame and perilla protein isolates were determined at pH range of 2-10 and ionic strength of 0-0.5M NaCl. Nitrogen solubility of protein isolates in distilled water showed minimum value at pH6.0 in sesame and at pH 4.0 in perilla and soybean protein isolates, and significantly increased above pH 8.0 in all samples. Addition of 0.1M NaCl solution increased nitrogen solubility, however, decreased in 0.5M NaCl solution. Emulsion activities of all the protein isolates showed minimum value at pH 4.0 and increased in 0.1M NaCl solutions while it was reduced in 0.5M NaCl solutions. The perilla protein isolate showed higher emulsion activity than that of soybean and sesame protein isolates at above pH 6.0. Foaming capacities of sesame and perilla protein isolates were lower than soybean protein isolate and generally all of the samples showed higher profiles in NaCl solutions. The foaming stability of soybean isolate decreased abruptly in 10min, while it was slowly decreased for sesame and perilla isolates during initial 30 min. Oil absorption capacity of perilla protein isolate was higher than that of sesame and soybean protein isolates. Water absorption capacity was similar among the three samples studied.

• The Korean Journal of Ecology
• /
• v.26 no.5
• /
• pp.273-280
• /
• 2003

Saline conditions invoke oxidative stress attributed to the overproduction of reactive oxygen species (ROS). Changes in quantum efficiency and antioxidative enzyme activity upon salt treatment were examined in a salt-tolerant plant, Atriplex gmelini, to test the hypothesis that salt tolerance of A. gmelini is due to the increased activity of antioxidative enzymes. A. gmelini showed optimum growth at 100 mM NaCl producing 116% of the shoot dry weight over control plants in 0 mM NaCl treatment. Healthy growth persisted up to 300 mM NaCl treatment maintaining normal internal water content and dry weight. No photochemical stress or damages on antioxidative defense system was obvious in plants of 2 and 4 day salt treatment which was indicated by increased quantum efficiency (Fv/Fm value), decreased stress index (Fo/Fm value), and increased activity of antioxidative enzymes such as SOD, APX, GR. However, the plants treated with 400 mM NaCl showed decrease in growth and in antioxidative enzyme activity although the enzyme activity was still higher than that of the 0 mM NaCl treated plants (l31%, 114%, and 134% of the SOD, APX, and GR activity, respectively). Interestingly, another important antioridative enzyme that scavenges H₂O₂ in plant cells, CAT, showed rapid decrease in its activity as salt concentration increased; 38%, 22%, 15% of the 0 mM NaCl treated plants at 200, 300, 400 mM NaCl treatments, respectively. It appears that the enzymes in ascorbate-glutathione cycle such as APX and GR play the major roles in scavenging ROS produced by salt stress in A. gmelini. After 6 days of salt treatment, the damage in photochemical and antioxidative defense system was indicated by decreased Fv/Fm value and increased Fo/Fm value. A. gmelini appears to cope with short term salt treatment by enhanced activity of the antioxidative defense system, whereas long term stress invoke oxidative stress by increased ROS due to the damages in photochemical and antioxidative system.

• Korean Journal of Food Science and Technology
• /
• v.11 no.3
• /
• pp.153-156
• /
• 1979

Spoiled mushroom cans were collected from several canneries and examined the spore bearing bacteria in them. Thirty four isolates of anaerobic mesophiles were isolated. The one isolate(Cl-5) which was the most heat stable among the above isolates, the other isolate (D-29) which was examined in the previous experiment (Korea J. Food Sci. Technol., 10(2), 224 (1978) and PA 3679 were compared their heat resistancy in neutral phosphate buffer. They were confirmed the spoilage of mushroom products. Z value and $D_{250}$ value of the Cl-5(isolated from mushroom casing soil at Gimjae) possessing the highest resistancy were $21.3^{\circ}F$ and 1.8 min in mushroom can (4 oz. piece and stem). It's F value was 8.95 when Z value was 21.3.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.20 no.2
• /
• pp.133-136
• /
• 1984

The characteristics of the stress corrosion cracking of SUS 304 stainless steel were studied with the specimens of the constant displacement type under the environment of various MgCl sub(2) aqueous solutions. Main results obtained are as follows; 1) Latent time of crack initiations is delayed in the SCC under low condition of initial stress intensity K sub(Ii) value. 2) SCC occurs owing to the passive film-rupture by both load and Cl ion under MgCl sub(2) boiled aqueous solution. 3) The susceptibility of SCC can be largely improved by reducing the temperature in case of the high concentration of MgCl sub(2) aqueous solution.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.2
• /
• pp.308-312
• /
• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• Biomedical Science Letters
• /
• v.24 no.3
• /
• pp.270-274
• /
• 2018

Chlorine dioxide ($ClO_2$) gas is a neutral chlorine compound. $ClO_2$ gas was proven to effectively decontaminate different environments, such as hospital rooms, ambulances, biosafety level 3 laboratories, and cafeterias. In this study, to evaluate the effects of $ClO_2$ gas, bacteria of clinical importance were applied. Staphylococci, Streptococci and Bacillus strains were applied and Klebsiella, and others e.g., Escherichia coli, Shigella, Salmonella, Serratia were also done for the inhibitory analysis. Bacteria plates were applied with a hygiene stick, namely, "FarmeTok (Medistick/Puristic)" to produce $ClO_2$. $ClO_2$-releasing hygiene stick showed the very strong inhibition of bacterial growth but had different inhibitions to the bacteria above 96.7% except for MRSA of 90% inhibition. It is difficult to explain why the MRSA were not inhibited less than others at this point. It can be only suggested that more releasing $ClO_2$ should be essential to kill or inhibit the MRSA. B. subtilis, S. agalactiae, S. pyogenes, E. coli O157:H7, S. typhi (S. enterica serotype typhi) and S. marcesence were inhibited over 99%. This study will provide fundamental data to research growth inhibition by $ClO_2$ gas with bacteria of clinical importance value.

• Proceedings of the KIEE Conference
• /
• 2004.11a
• /
• pp.187-190
• /
• 2004

In this work, we investigated etching characteristics and mechanism of BST thin films using $Cl_2$/Ar, $CF_4/Cl_2$/Ar and $BCl_3/Cl_2$/Ar gas mixtures using inductively coupled plasma (ICP) system. A chemically assisted physical etch of BST was experimentally confirmed by ICP under various gas mixtures. The etch rate of the BST thin films had a maximum value at 20 $BCl_3$ and 10% $CF_4$ gas concentration, and decreased with further addition of $BCl_3$ or $CF_4$ gas, because $BaCl_x$, $SrCl_x$, $BaF_x$ and $SrF_x$ compounds have higher melting and boiling points. The maximum etch rate of the BST thin films was 57nm/min at the 30% $Cl_2(Cl_2+Ar)$. The characteristics of the plasma were analyzed by using OES and Langmuir probe.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1998.10a
• /
• pp.87-90
• /
• 1998

1. 서론 : 막 분리공정에 사용되고 있는 대부분의 고분자 막들은 침지침강(immersion precipitation) 상변환법에 의해 제조되고 있다. 침지침강 상변환법으로 제조된 막의 최종 구조는 고분자 캐스팅 용액의 열역학적 특성과 비용매와의 속도론적 특성에 따라 대칭형 또는 비대칭형 막구조를 갖게 된다. 고분자/용매로 이루어진 캐스팅 용액에 제3의 성분으로서 PVP, PEG, LiCl. ZnCl$_2$ 와 같은 유.무기물을 첨가시킴으로서 막구조 및 투과성능을 변화시킬 수 있다. 이러한 점에서 이들 첨가제를 pore-forming agent라 부르기도 한다. 본 연구에서는 상대적으로 열적.기계적 특성이 우수하고, 화학약품에 대한 안정성이 뛰어나 상변환 막의 소재물질로서 널리 사용되고 있는 Polyethersulfone(PES)을 막 소재 물질로 사용하여 PES/NMP 캐스팅 용액에 다양한 종류의 무기염[CaCl$_2$, LiCl, LiClO$_4$, Mg(ClO$_4)_2$, ZnCl$_2$]을 PES에 대한 중량비를 달리하여 첨가시켜 비대칭 막을 제조하여 무기염의 첨가가 막구조 형성 및 막투과 특성에 미치는 영향을 연구하였다. 이때 첨가된 무기염 및 첨가 중량비에 따른 영향을 PES/NMP/Salt 계의 coagulation value, light transmittance, 점도 등의 열역학 및 속도론적 특성으로서 설명하였다.

• Elastomers and Composites
• /
• v.50 no.4
• /
• pp.304-313
• /
• 2015

In this study, the anionic emulsified asphalt was prepared by dispersing asphalt particles evenly into water with combination of anionic and nonionic surfactants. Effects of NaOH and $CaCl_2$ on the phase stability of the emulsified asphalt were also investigated through zeta potential value and rheology behavior; the emulsified asphalt added with NaOH and $CaCl_2$ showed higher zeta potential value than that the asphalt with addition of only anionic and nonionic surfactants. In addition, with regard to shear thinning behaviors, it was found that pH of the emulsified anionic asphalt and $Ca^{2+}$, counter ion, affected the phase stability. SBR (styrene-butadiene-rubber) latex, EPD (water dispersed Epoxy), PU (polyurethane) and RI-10S, SBS (styrene-butadiene-styrene)-based property improvement additive, were used and studied to enhance the adhesion properties with the aggregates. RI-10S, however, was found to be only compatible with the anionic emulsified asphalt; the coating rate, adhesion and compression strength were increased with the RI-10S content.

• Economic and Environmental Geology
• /
• v.36 no.5
• /
• pp.339-347
• /
• 2003

Using 171 groundwater chemistry data, seawater intrusion in the Ulsan area was studied. The area near the downstream area of the Taehwa River shows the higher Cl concentrations(11,300 mg/L in maximum), whereas the Cl concentrations are generally low in the eastern coastal area maybe due to the geology of the area. When Cl concentrations are very low, groundwater shows Br:Cl weight ratios significantly deviating from the Br:Cl ratio of seawater($34.7{\times}10^{-4}$). However, Br:Cl ratios are very close to the value of seawater when Cl concentrations are higher than 100 mg/L. Eleven groundwater samples having very high Cl concentrations(>500 mg/L) show that ionic ratios for Ca, Mg, $SO_4$, $HCO_3$ and $SiO_2$ are considerably different from those of seawater. This indicates that the origin of the high Cl groundwaters occurring along the Taehwa River are likely to be the residual salines from the salterns previously located on the alluviums rather than the seawaters intruded recently. These waters seem to be accumulated in the sediments before the drastic expansion of the city. Considering the characteristics of the urban groundwater system where the inflow exceeds the outflow, it is anticipated that the high Cl concentration in the groundwater show a decreasing trend in the future.