• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.778-786
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• 2017

In this study, analyzed the changes occurred after adding casein emulsions to water - dispersed polyurethane using polypropylene glycol (PPG). For this purpose, anionic water - dispersed polyurethane containing PPG, IPDI and DMPA and casein emulsion prepared by dissolving casein in distilled water using ammonia water were prepared. As a result of measuring the alkali resistance by using the prepared resin, there was no change in the physical properties. The tensile strength of the sample having a high casein content was measured to be $2.227kgf/mm^2$. Elongation was measured at 474% for samples containing less casein and The abrasion resistance was measured as 46.090 mg.loss of sample containing much casein as a result of the surface roughness measurement.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.527-534
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• 2021

The demand for sustainable extraction of bioactive compounds from food matrices has been increasing. Water extraction of anthocyanins in aronia was investigated using conventional and ultrasonic-assisted methods. The optimum extraction conditions for the conventional method included a sample-to-water ratio of 1:40 g/mL, extraction temperature 71℃, and extraction time of 39 min. The optimized conditions for ultrasonic-assisted extraction were a sample-to-water ratio of 1:40 g/mL, extraction temperature 80℃, extraction time of 20 min, and an amplitude of 87.2 ㎛. The anthocyanin contents of the two extracts were 155.32 and 158.02 mg/100 g fresh weight, respectively. The major anthocyanins were cyanidin 3-galactoside (65% of the total) and cyanidin 3-arabinoside (30% of the total). The contents of individual anthocyanins and phenolic acids were not significantly different between the two optimized extracts.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.56-63
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• 1996

The results of the water purification studies using water parsley (Oenanthe javanica) were obtained as follows. The removal rate of nutrient salts increased with longer plant growth periods. The results of this study use the assumption, log(T+1) = $K(C_0-C)^A$, based on Prakish's Theory. The initial concentration was calculated from experimental data. A and K are closely related to the initial concentration. It is possible to model the concentration of residual salts, as time goes by, if concentration is constant. It was observed that water parsley neutralizes acid and alkali substances promptly. The maximum suitable neutralization period is 48 hours. But water parsley withered up in strong acid and alkali solutions within a week. The removal efficiency of Cd progresses in 2 steps, which are unrelated to the initial concentration of Cd. The first part of the curve shows the concentration rapid rate of Cd removal, followed by a levelling off. The removal rate of $NO_x-N$ in the sample water tank containing 0.5 ppm Cd was between 50~80% but the removal rate was less than 20% for the higher concentration. On the other hand, increased amounts of $PO_4-P$ in the sample water tank from the third day on suspected that $PO_4-P$ was desorbed from the water parsley. The accumulation efficiency of Cd in plant was increased in proportion to the initial concentration of Cd. The accumulation phenomenon was observed in the tanks more than 50~100 times.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.27-28
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• 2019

In this study, the characteristics of compressive strength of ultra high strength concrete supplied with moisture from outside by vacuum water absorbing curing method were investigated. Specimens were prepared by replacing the binder(Silifa fume and GGBS) by 25 wt% with respect to the weight of cement at W/B 0.16. Each specimen was subjected to water Vacuum absorbing curing time 0 min, 30 min, 60 min, 90 min and 120 minutes immediately after the demolding. Curing was performed at $20^{\circ}C$ Air-dry curing, $90^{\circ}C$ steam curing, $90^{\circ}C$ steam curing and $180^{\circ}C$ autoclave curing. Experimental results showed that water absorbing degree increased with increasing water absorbing curing time, and BS25 sample had higher water absorbing degree than SF25 sample at same time. Compressive strength tended to increase up to about 40% in water absorbing degree, but compressive strength decreased again in water absorbing more than 40%.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.272-277
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• 2014

At present, the index of chemical oxygen demand (COD) is widely used as an indicator of organic water pollution with biochemical oxygen demand (BOD). But, traditional COD measurement method are not only with various chemical reagents exhausted, but also long time consumed, the operation procedure and the modification are much professional. This paper reported a novel COD measurement system using double-beam and multiple wavelength analysis UV-VIS spectrometries. It consists of pulsed xenon lamp, two-way optical fiber, optical switch, spectrometer and main processor. Proposed COD measurement system obtains any spectral information of water sample (KHP standard sample and two river water and wastewater) and reference sample (distilled water) in the range of 200~520 nm, corresponding to the COD concentration from 0 to 300 mg/L through calculating the UV absorbance. The system show improved precision and can work continuously fast at time interval about 25 seconds.

• Journal of Radiation Protection and Research
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• v.13 no.2
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• pp.52-56
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• 1988

An ion-exchange method for the detection of radioactivity in water using ion-exchange resin in concentrating radioactive nuclides was compared with an evaporation method. The loss of the radioactive materials in the sample treated by the ion-exchange method was less by about 20% than that by the evaporation method. In addition, the evaporation method needed about 20 hours for evaporating one liter of the sample at $70^{\circ}C$, while the ion-exchange method spent 6 hours to adsorb and adsorb the same amount of the sample on the resin. Consequently, the ion-exchange method is more effective than the evaporation method for the treatment of the radioactively contaminated water and is especially suitable for detecting the low-level radioactivity in water.

• The Korean Journal of Malacology
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• v.18 no.2
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• pp.83-91
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• 2002

Reproductive cycle of natural population and artificial control experiments of gonadal development by the conditions of water temperatures-feeding and starvation of Ruditapes philippinarum were investigated by histological observations. The reproductive cycle of natural population in females and males can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (May to October), and spent-inactive stage (August to March). In the artificial control experiments, gonadal development of this species was inhibited by the low water temperature (10$^{\circ}C$). In the experimental group which was exposed to artificial high water temperatures of 19$^{\circ}C$ and 22$^{\circ}C$, gonadal development was accelerated by the higher water temperatures and was faster (about one month) than that in natural populations. In the high water temperatures-feeding experimental group, the gonadal developmental phase was faster in the small-size group than that in the large-size group, and was faster in lower water temperature (10$^{\circ}C$)(p=0.01). The gonad developmental phases in the high water temperature (22-28$^{\circ}C$)-starvation experimental group showed faster (paired sample t-test, p=0.004) than those in the high water temperature-feeding group in females and males. In the high water temperature-feeding experimental group of female and male gonadal developments of small sized group were more sensitive than those in large sized group after 42 days cultivation, However, the gonadal development of male was more sensitive to the lower water temperature than female. On the whole, sexual maturation in the high water temperature experimental group was faster than those in the low water temperature group, and showed a significant difference (paired sample t-test, p=0.001) between female and male. In the starvation experimental group after 42 days, gonadal developments in the high water temperature-large male group showed faster than those in the high water temperature-large female group. However, in small size, gonad developmental phases showed the same pattern between feeding and starvation experimental groups. During the main spawning season, in the high water temperature-starvation experimental groups in females and males, their gonadal development showed faster than that in higher water temperature-feeding experimental group regardless of their sexes and individual sizes and showed a significant difference (paired sample t-test, p=0.004).

• Journal of Korean Society of Forest Science
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• v.3 no.1
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• pp.18-22
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• 1963

1. Objects The experiments of catalytic aharcoaling were carried out for the fallowing purposes. (1) To determine the economically desirable amount of catalytic materials to be used when a catalytic charcoaling is practiced. (2) To observe the rate of carbonization of non-treated charcoal wood when the catalytic charcoaling is proceeded in the same charcoal pit. 2. Meterials (1) Small sample chips made of oak (Q. accutissima Carr.), measured by 0.5cm in width and thickness, respectively, and 1cm in length, were used as charcoal wood in each experiment. (2) Ammonium chloride was used as a catalytic material and electric kiln as a charcoaling apparatus. 3. Experiment (1) The sample chips were put into a electric oven for three hours at the temperature $60^{\circ}{\sim}70^{\circ}C$ in order to reduce some water contents. (2) Oven dried sample chips were then soaked for an hour in solution of ammonium chloride. Three kinds of solution were prepared, that is, 2.5%, 5%, and 10%, solution in which the amount of ammonium chloride used was weighed at the rate of 0.5%, 1.0%, and 2.0% to the total weight of the sample chips, resppectivelly. (3) Soaked sample chips were put in the air for 12 hours to reduce some water contents, and then were put into electric oven for 2 hours at the temperature $105^{\circ}{\sim}110^{\circ}C$. (4) Dried sample chips were kept in a desiccator with control sample chips which were treated excarly the same process as the treated sample chips except only not using the ammonium chloride in the process of soking. (5) Sample chips kept in the desiccator were used at random in each charcoaling experiment. (6) Charcoaling in the electric kiln were carried out by using small crucibles with complete cover to reduce the amount of ash. At each charcoaling experiment four crucibles filled with sample ships, weighed about 20gr, were put into electric kiln. The charcoaling was continued for an hour at the temperature $400^{\circ}{\sim}450^{\circ}C$. (7) In order to investigate the influence given by the gases produced during the catalytic charcoaling to the rate of carbonization of non-treated sample chips, the following experiment was done. (a) A crueible was divided into two parts by inserting a fine iron net at the middle of the crucible, and then non-treated sample chips, weighed about 10gr, were put in the upper part of the crucible and treated sample chips, weighed also about 10gr, were put in the under part. (b) The crucibles filled with two kinds of sample chips were put into a electric kiln for an hour at the temperature $400^{\circ}{\sim}450^{\circ}C$. 4. Results. Results for two replications (with four crucibles in one replication) for each experiment designed are as follows : (1) The rats of carbonization of the non treated sample chips, and that of the treated sample chips with ammonium chloride at the rate of 1.5%, 1.0%, and 2.0% to the total weight of the sample chips used were averaged at 19.85%, 22.63%, 24.14%, and 26.60%, respectively. (2) The rats of carbonization of the non-treated sample chips were averaged at (a) 20.04% (0.5% treatment), (b) 20.28% (1.0% treatment), and (c) 20.61% (2.0% treatment) when the treated sample chips were carbonized in the same crucible.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.6
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• pp.1026-1031
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• 2011

This experimental study was designed to investigate the inhibitory effects of hot water extract of Yukeuigambi-tang (YEGT) on high-fat diet-induced obesity and hyperlipidemia in C57BL/6 mice. Animals were divided into normal, control, YEGT(sample A 3.8 g/kg, and sample B 7.6 g/kg) treated group. Obesity with hyperlipidemia was induced by high fat diet treatment for 6 weeks. YEGT was given to the animals by oral gavage. The effect of YEGT on the body weight change, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, and leptin levels in serum were evaluated. In respect to the body weight change, sample B significantly reduced body weight compared with control group in the 6th weeks. In the total cholesterol, triglyceride, and leptin level, sample B significantly reduced all of them compared with control group; sample A significantly reduced triglyceride and leptin levels compared with control group. The above results suggest that YEGT is effective to prevention and treatment of obesity and hyperlipidemia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1013-1020
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• 1997

To elicit the effect of fermentation on food quality of the watery Chinese cabbage pickles without fish sauce and red pepper paste(Baik-kimchi), changes in physicochemical properties and microstructure of fiber components were studied. Better water holding capacity(WHC) was showed in Baik-kimchi fermented at $25^{\circ}C$ than that of Baik-kimchi fermented at 5$^{\circ}C$. WHC measured at pH 2 and 6 were ranged from 10.18 to 16.79g/g dried sample for Baik-kimchi fermented at $25^{\circ}C$ and 6.51~14.58g/g dried sample for sample for samples at 5$^{\circ}C$, respectively. The higher WHC was resulted in pH controlled freeze-dried sample to pH 6 than that measured in pH 2 sample. The settling volume(SV) and oil adsorption capacity(OAC) increased with fermentation period and kept the same value for a little while, but slightly decreased in the over ripening period. Baik-kimchi fermented at $25^{\circ}C$ exhibited more shrunk microstructure of parenchyma cell and xylem than those of Baik-kimchi fermented at 5$^{\circ}C$. The appearance of SDF of the both Baik-kimchi ripened at 5$^{\circ}C$ and $25^{\circ}C$ could give granular shape, whereas the overripened Baik-kimchi had smooth surface of SDF. On the other hand, the IDF retained the original shape during fermentation.