• Membrane Journal
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• v.21 no.3
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• pp.213-221
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• 2011

Using poly(ethylene oxide) (PEO) as a polymer host, poly(ethylene glycol) (PEG) as a plasticizer, potassium iodide and iodine as sources of $I^-/I_3^-$, polymer electrolyte membranes were prepared. Based on the polymer electrolytes, solid-state dye-sensitized solar cell (DSSC)s were fabricated. The content of PEG in the electrolyte was controlled to be 95%. The mole number of KI per 1 mole of EO ([KI]/[EO] ratio) in the electrolyte was changed to be 0.022, 0.044, 0.066 and 0.088. The electrolyte membrane showed wax phase in ambient temperature. The ionic conductivity increased with increasing KI content to reach the maximum value at which [KI]/[EO] ratio is 0.066. After the maximum value, the ionic conductivity decreased with increasing KI content. In the case of DSSC, the Voc decreased continuously with increasing KI content in the polymeric electrolyte membrane. The $J_{SC}$ increased with increasing KI content to show maximum value at which [KI]/[EO] ratio is 0.044. In the higher KI content region, $J_{SC}$ value decreased with increasing KI content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.965-970
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• 2003

This study has been performed to develope a method for the simultaneous determination of 1,4-dioxane (DOX), epichlorohydrin (EPC), propylene chlorohydrin (PCH), ethylene chlorohydrin (ECH) and 1,3-dichloro-2-pro-panol (DCP) in polysorbates, chloline chloride, choline bitartrate, modified starch and spices by purge and trapgas chromatography. Experimental design was used to select a suitable trap by measuring the limit of detection (LOD) and to investigate the effect of temperature and salt of extraction, and the percentage of recovery in various matrix. The LOD of DOX, EPC, PCH, ECH and DCP were 1.38$\mu\textrm{g}$, 0.23$\mu\textrm{g}$, 3.30$\mu\textrm{g}$, 3.97$\mu\textrm{g}$, 20.43$\mu\textrm{g}$ respectively, by means of using Vorcarb 3000 trap with 5$0^{\circ}C$ sample sparger. Excluding EPC, the recoveries of target compounds were above 90% in all matrix. Target compounds in polysorbates (17), choline chloride (5), choline bitartrate (5), modified starch (8) and spices (25) were not detected. But 2.5 ppm of DOX was detected in Tween 80.

• Korean Journal of Community Nutrition
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• v.19 no.6
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• pp.513-526
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• 2014

Objectives: This study was conducted to investigate the effect of low sodium diet education program on dietary habits, diet quality, and measures of obesity in overweight or obese middle-aged women. Methods: Subjects were 81 individuals aged 45 years or over, who completed an 8-week nutrition education. The subjects were divided into a normal group (N = 30) and an overweight-obese group (N = 51) according to the BMI. The effects were evaluated by anthropometric measurement, biochemical analysis, questionnaire, and diet records before and after the program. Results: Overweight-obese group showed significant decreases in weight (p < 0.0001), BMI (p < 0.0001), percent of body fat (p = 0.0087), waist circumference (p < 0.0001), systolic (p = 0.0003) and diastolic blood pressure (p = 0.0261). Nutrients intakes were not different between the two groups and only sodium intake was decreased after education. Total score of general dietary habits, dietary behavior related to sodium intake, dietary diversity score (DDS), diet variety score (DVS), and diet quality index-international (DQI-I) were improved in both groups compared to the baseline. Overweight-obese group showed significant improvement in 'having fruits everyday', 'having fish everyday', 'trying to eat many kinds of food', 'eating less broth when eating soup, stew, and noodles', 'eating less kimchi and salt-fermented vegetable', and 'propensity to think that dishes should be pretty seasoned'. In addition, moderation of empty calories food (p = 0.0064) and macronutrient ratio (p = 0.0004) were improved in the overweigh-obese group, but in the normal group, the results did not reach statistical significance. Conclusions: These results suggested that low sodium diet education program may contribute to obesity management by improving diet quality and dietary habits in middle-aged women.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1017-1023
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• 2010

This study investigated the effect of surfactants (nonionic surfactant (Tween 20), biosurfactant) on enhancing transport of bacteria (Bacillus subtilis ATCC 6633) in geological materials. Column experiments were performed under various surfactant conditions with columns packed with quartz sand (particle size distribution: 0.5~2.0 mm, mean diameter: 1.0 mm). Bacterial mass recovery, sticking efficiency, and other parameters were quantified from breakthrough curves. Results indicate that bacterial attachment to sand surfaces increased considerably in the presence of mineral salt medium (MSM), especially at the inlet, which was due to the increase of ionic strength by MSM. It was observed that bacterial transport in sand columns was enhanced in the presence of surfactant. Results also show that simultaneous injection of both surfactant and MSM or pre-injection of surfactant was more effective in bacterial transport enhancement than after-injection of surfactant. This study suggests that transport of bacteria in geological materials could be influenced by surfactants and their injection methods.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.124-129
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• 2017

The Experiments were conducted by moderate season culture of each of early, medium and late maturing varieties which were considered to be of strong salt tolerance in low and high salty reclaimed areas (0.2% at the May). This study was carried out to investigate the proper nitrogen fertilizer level and seeding rates at reclaimed saline land in Korea. The proper seeding rates were $40kg\;ha^{-1}$ in 0.2% saline land. The dry matter production of barnyard millet was possibly estimated by exponential functions of $Y=0.0098X^2+0.7030X+2.6267$. Effects of nitrogen rate on agronomic characteristics, forage yield, and chemical composition of barnyard millet to reclaimed tidal land are summarized as follows: The proper nitrogen fertilizer level was $200kg\;ha^{-1}$ in 0.2% saline land. N was absorbed actively before the emergence of the barnyard millet but showed relative decrease thereafter. The early growth of the barnyard millet was inhibited, resulting in the favorable late growth, increased panicle weight and ratio of matured grain. These results suggest that barnyard millet is the most forage crops for cultivation on reclaimed tideland in view of the good emergence and forage production.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.532-537
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• 1991

Effect of storage temperature fluctuation on quality of frozen breaded raw shrimp was studied. Storage experiments were undertaken as follows; First, after storage at $-20^{\circ}C$ for 20 days or 40 days, storage temperature of materials were raised to $-15^{\circ}C\;or\;15^{\circ}C$, and then stored at these temperatures, And second, by repeating for 5, 10 and 15 times by 3 conditions ($-20{\rightarrow}-15^{\circ}C{\rightarrow}-20^{\circ}C,\;-20{\rightarrow}-10^{\circ}C{\rightarrow}-20^{\circ}C\;-20{\rightarrow}-5^{\circ}C{\rightarrow}-20^{\circ}C$) with temperature fluctuation during storage. Quality changes were measured by determining extractability of salt-soluble protein, volatile basic nitrogen, thiobar-bituric acid, pH and microbiological changes at regular intervals. Rise in storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ had not caused significant change on it's quality, but rise up to $-5^{\circ}C$ caused some change in quality without relationship with storage period before temperature rise. Fluctuation of storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ of frozen breaded raw shrimp did not cause noticeable changes on it's quality. But temperature fluctuation from $-20^{\circ}C\;to\;-10^{\circ}C\;or\;-5^{\circ}C$ caused remarkable changes of it's quality, according to the increase of fluctuation times and temperatures.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.168-174
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• 2005

This study was carried out to investigate the feeding effect of wild grape wine by-products on pork qualities. The chemical composition, volatile basic nitrogen, thiobarbituric acid reactive substances and pH were not significantly different between control and wild grape pork, but the cholesterol and roast loss of wild grape polk. were lower than those of the control, and 1l1e salt soluble protein extractability of the control was lower than that of the wild grape pork. The Hunter's $a^{\ast}$ and $b^{\ast}$ value of wild grape polk. meat were higher than the control, the $a^{\ast}$ value of wild grape polk. meat was higher than the control, but the $L^{\ast}$ value of meat and fat were not significantly different between control and wild grape pork. The cohesiveness, gumminess and chewiness of control(respectively $66.2\%$ 428kg and 189g) were higher than wild grape polk. (respectively $61.4\%$ 357 kg and 154 g). The total amino acid composition of polk. were not significantly different between control and wild grape wine, The glutamic acid, leucine, arginine and aspartic acid were major amino acids in control and wild grape pork. The arachidonic acid $(C_{20:4})$, EPA $(C_{20:5})$ and DHA $(C_{22:6})$ of wild grape polk. were higher than those of the control. The taste (p<0.001), aroma (p<0.05), flavor (p<0.001), juiciness (p<0.01) and palatability (p<0.01) of wild grape polk. were higher than those of the control, but the texture between control and wild grape polk. were not significantly different.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1023-1035
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• 2015

This study applies 3-D N-S solver based on PBM (Porous Body Model), LED-WASS-3D ver 2.0 to directly analyze non-linear interaction of seawater-freshwater-coastal aquifer in order to simulate the seawater infiltration into coastal aquifer. This numerical simulation is the first trial in Korea, as well as unusual and new numerical analysis abroad. Firstly, to validate the applied numerical model, the validity and effectiveness was verified for the numerical model by comparing and considering it with the result of laboratory experiment for seawater-freshwater interface in coastal aquifer. And then it simulated the seawater infiltration into coastal aquifer considering the changed levels of seawater and groundwater in order to analyze the distribution characteristics of flow field and seawater-freshwater interface of coastal aquifer as the level difference between seawater and groundwater and rate of seawater level (${\Delta}h/h$) increased. In addition, the characteristics of seawater infiltration were analyzed from the vertical salinity in the coastal aquifer by ${\Delta}h/h$, which cannot be obtained from existing non-diffusion numerical models. Finally, it analyzed the effect of ${\Delta}h/h$ on the seawater infiltration distance in coastal aquifer, which was indexed.

• Journal of Mushroom
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• v.17 no.4
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• pp.235-240
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• 2019

In this study, we investigated the effects of pH, temperature, and salt concentration on protease activities in Hypsizygus marmoreus, and the ability of H. marmoreus extract to tenderize beef. In fact, H. marmoreus was shown to have higher protease activity than kiwi fruits. The pH of beef was dose dependently increased with addition of H. marmoreus extract. Cooking loss, cutting strength, and color value (L, a, b) were also dose dependently decreased with addition of H. marmoreus extract. In sensory assessments, H. marmoreus extract dose dependently enhanced perception of tenderness, flavor, and taste. In contrary, use of kiwi fruits as a meat tenderizer decreased positive perception of taste. The protease activitiy of H. marmoreus decreased sharply at pH < 2.0, and temperature > 50 ℃. Protease activity was relatively stable in NaCl concentrations ranging from 0-5 M, but incrementally decreased with increasing NaCl. These results suggest that, H. marmoreus extract can improve the texture and taste of beef.

• Analytical Science and Technology
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• v.14 no.3
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• pp.230-237
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• 2001

In general, the pH measurement follows calibration of glass electrode system using pH standard solution. When pH is measured at constant temperature, uncertainty factors are mainly related to the accuracy of pH standard solution and the accuracy and precision of glass electrode. Participants in this proficiency test were the volunteers trying to know the distribution of the measured pH values for the same sample and the sources of error through 1998 and 1999. The samples for proficiency test are phosphate salt standard solutions specially prepared in KRISS, of which pH values were 6.860, 7.415(at $25^{\circ}C$), and the stability test was performed for the same periods of proficiency test. The results of the proficiency test were plotted according to Youden plot, which shows whether the error is random or systematic. The results of Youden plot showed that the source of error was from the systematic effect of laboratories in each year. This shows that the source of error is the standard solutions used in laboratories.