• Membrane Journal
• /
• v.25 no.3
• /
• pp.203-215
• /
• 2015

Chlor-alkali (CA) membrane process is based on salined water electrolysis employing cation condutive polymer electrolytes, which has been used for the conventional production of both sodium hydroxide and chlorine gas. The CA membrane process has advantages such as relatively low environmental impacts and fairly reduced energy consumption, when compared with diaphragm and mercury process. In this review articles, basic concepts, fundamental characteristics, key technologies of CA membrane process are dealt with in detail. In addition, advanced technologies associated with CA membrane process are described. They include zerogap and oxygen depolarized cathode technologies to improve energy efficiency during the electrolysis. Carbon dioxide mineralization technology will also be introduced as an example of hybridization with different technologies. Finally, current market trend in CA membrane process will be presented.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.576-580
• /
• 1997

Lipoxygenase activity in Chinese cabbage was measured at various concentrations of brines. Lipoxygenase activity on linoleic acid substrate was determined by changing the rate of dissolved oxygen consumption. The inactivation of lipoxygenase by salting was increased when concentration of sodium chloride and soaking time were increased. About 60% of enzyme activity was reduced after submerging in 13% brine solution for 5 hr. The addition of calcium chloride (0.7%) reduced about $10{\sim}15%$ of lipoxygenase activity rather than without. Residual activity of lipoxygenase in Chinese cabbage submerged in 13% brine was 20% and about 60% of lipoxygenase was also inhibited by addition of garlic extract.

• Journal of the East Asian Society of Dietary Life
• /
• v.7 no.3
• /
• pp.375-382
• /
• 1997

This study was performed to evaluate the nutrient intake status according to coffee intake among Korean female college students. Two-hundred subjects were asked for their daily coffee intake using a questionnaire. Daily intakes of nutrients and food groups were calculated 3-day food records. The mean height and weight of the subjects were 161.6cm and 51.2kg. The mean daily intake of coffee and milk were 0.5 and 0.6 cups, respectively. When nutrient intake was compared to RDA for Koreans, intakes of energy, iron, vitamin A were short of recommendations. The mean intakes of calcium, sodium, vitamin B$_2$ in BMI＜20 group were significantly higher than those in BMI $\geq$20 group. The mean intakes of calcium and phosphorous in no-coffee group were significantly higher than those in $\geq$2 cup-coffee group. The mean intake of beverage and others significantly increased as the level of coffee intake was increased. However, intake of milk and its product decreased. There were significantly negative correlation between coffee and calcium intake, and positive correlation between milk and calcium intake. These results indicate that coffee consumption decreases calcium intake because of decrement of milk and its products. Therefore, it could be suggested that there is increased need for nutritional education on proper eating patterns for female college students.

• Journal of the Korean Solar Energy Society
• /
• v.33 no.5
• /
• pp.24-33
• /
• 2013

Renewable energy industries, including sola cell plants, has been ever increasing ones for reducing fossil fuel consumption and strengthening national energy policy. In this paper we tried to identify occupational health hazards in solar cell-related industries operated in Korea. Poly silicon, silicon ingot and wafer, solar cell and module are major processes for producing solar cells. Poly silicon operations may cause hazards to workers from metal silicon, silanes, silicon, hydro fluoric acid and nitric acid. Solar cells could not be constructed without using metals such as aluminum and silver, acids such as hydrofluoric acid and nitric acid, bases such as sodium hydroxide and potassium hydroxide, and solvent and phosphorus chloride oxide. Workers in module assembly process may exposed to isopropanol, flux, solders that contain lead, tin and/or copper. To prevent occupational exposure to these hazards, it is essential to identify the hazards in each process and educate workers in industries with proper engineering and administrative control measures.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.4
• /
• pp.19-26
• /
• 2012

The influence of operation time on electrokinetic restoration was investigated to remove salts from sulfate-accumulated greenhouse soil. Operation time is directly related to the process cost, therefore, we determined the relationship between operation time and removal of salts. Nitrate and sodium were removed almost completely within 2 weeks, chloride and calcium was removed in proportion to the operation time. Sulfate was accumulated at the center of anode and cathode. The soil electrical conductivity (EC), an indicator for soil salinity, showed similar shape with the residual sulfate after electrokinetic treatment. The soil EC was not changed after 2 weeks, however, the energy consumption increased with operation time. Based on the experimental results, most salts except sulfate were removed within 2 weeks, but sulfate was not removed during same time period. For the further removal of sulfate, longer operation time is in need.

• Clinical and Experimental Pediatrics
• /
• v.64 no.8
• /
• pp.408-414
• /
• 2021

Background: Complementary food in infancy is necessary for human growth, neurodevelopment, and health. However, the role of allergen consumption in early infancy and its effects on the development of food allergy or tolerance remain unclear. Purpose: To investigate the influence of age at the time of complementary food introduction on the development of asthma and atopic dermatitis in Korean children aged 1-3 years. Methods: We combined data from the Korea National Health and Nutrition Examination Survey collected from 2010 to 2014 and analyzed 1619 children aged 1-3 years who were included in the survey. Multivariate regression analysis was used to identify associations among type of feeding, age at the time of complementary food introduction, and doctor-diagnosed atopic dermatitis and asthma. Results: Age at the time of complementary food introduction was not significantly associated with doctor-diagnosed atopic dermatitis and asthma in children aged 1-3 years. In the univariate analysis, children with asthma showed higher water and sodium intake levels than nonasthmatic children. However, this relationship was not significant in the multivariate regression analysis. Conclusion: The present study revealed no statistically significant relationship between age at the time of complementary food introduction and the risk of atopic dermatitis and asthma in young Korean children. A national prospective study is needed to clarify the influence of age at the time of complementary food introduction on the development of allergic diseases.

• Nuclear Engineering and Technology
• /
• v.55 no.6
• /
• pp.2047-2052
• /
• 2023

Risk-informed approach has been widely applied in the safety design, regulation, and operation of nuclear reactors. It has been commonly accepted that risk-informed design optimization should be used in the innovative reactor designs to make nuclear system highly safe and reliable. In spite of the risk-informed approach has been used in some advanced nuclear reactors designs, such as Westinghouse IRIS, Gen-IV sodium fast reactors and lead-based fast reactors, the process of risk-informed design of nuclear reactors is hardly to carry out when passive system reliability should be integrated in the framework. A practical method for new passive safety reactors based on probabilistic safety assessment (PSA) and passive system reliability analyze linking is proposed in this paper. New three-dimension frequency-consequence curve based on risk concept with three variables is used in this method. The proposed method has been applied to the determination optimization of design options selection in a 10 MWth lead-based research reactor(LR) to obtain one optimized system design in conceptual design stage, using the integrated reliability and probabilistic safety assessment program RiskA, and the computation resources and time consumption in this process was demonstrated reasonable and acceptable.

• Korean Chemical Engineering Research
• /
• v.48 no.2
• /
• pp.275-282
• /
• 2010

A characteristic study of aqueous chlorine dioxide generation from sodium chlorite($NaClO_2$) by an undivided electrochemical cell with different anode materials were performed. $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA were used as anode materials and Pt-coated Ti electrode was used as cathode. Various electrochemical cell operating parameters such as cell residence time($t_R$), initial feed solution pH, sodium chlorite and sodium chloride(NaCl) concentration and applied current for the generation of chlorine dioxide in an un-divided cell were investigated and optimized. Estimated optimal cell residence times in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode material systems were around 2.27, 1.52 and 1.52 sec, respectively. Observed optimum initial feed solution pH was around 2.3 in all anode material systems. Optimum sodium chlorite concentrations in $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems were around 0.43, 0.43 and 0.32 g/L, respectively. Optimum electrolyte concentration and applied current were around 5.85 g/L and 0.6 A in all anode systems. Current efficiencies of $IrO_2$-coated Ti, $RuO_2$-coated Ti and DSA anode systems under optimum conditions were 79.80, 114.70 and 70.99%, respectively. Obtained energy consumptions for the optimum generation of chlorine dioxide were 1.38, 1.03 and $1.61W{\cdot}hr/g-ClO_2$, respectively.

• Journal of fish pathology
• /
• v.12 no.1
• /
• pp.32-41
• /
• 1999

Ozonization for rearing seawater in land-based culture system has recently been utilized for disinfection of pathogenic microorganisms and improvement of water quality. This study was conducted to examine the effects of total residual oxidants (TRO) in ozone-treated seawater on survival, blood parameters, osmolality and oxygen consumption, and gill tissue of the flounder. Paralichthys olivaceus. Experiments were carried out with the starved flounder of 12~19 cm in total length at $20^{\circ}C$. The 48-hr and 96-hr $LC_{50}$ for the flounder amounts to 26.4 ppb and 22.3 ppb, respectively. With increase of TRO concentration from 24 to 39 ppb, the values of hematocrit, hemoglobin concentration, red blood cell count and osmolality of the flounder with respect to exposure time were significantly elevated, however, the oxygen consumption rates decreased. In the case of the fish exposed to 13 ppb for 96 hrs, blood glucose increased with an elapse of exposure time, while survival rate was 100%. Death apparently resulted by massive destruction of gill lamellar epithelium, severe osmotic imbalance and the lack of oxygen uptake. The results of this experiment indicated that to protect aquaculture organisms, the ozone-treated seawater should not contain any residual oxidants, and that relatively long-term exposure to TRO of low concentration can impact on survival and physiological conditions of the flounder.

• Journal of Nutrition and Health
• /
• v.49 no.5
• /
• pp.335-346
• /
• 2016

Purpose: This study was conducted to conduct dietary assessment of Korean adults according to intake of Korean soup and stew. Methods: To accomplish this study, 20,926 adults aged 19 yr or higher who participated in the dietary intake survey (24 h recall method) were analyzed from the data of the 2011~2014 Korea National Health and Nutrition Examination Survey (KNHANES). The items included in the soup and stew were guk, tang, jjigae, jijimi, and jeongol. Results: Intakes of soup and stew of subjects were divided into quartiles; intake range by quartile was Q1: < 22.96 g, Q2: 22.96~98.75 g, Q3: 98.75~212.23 g, and Q4: $${\geq_-}212.24g$$. In the case of the Q4 group, male, married, employed, higher educated, and high income subjects showed increased intakes of soup and stew. In addition, sodium intake among nutrient intakes increased from 3,849.04 mg in Q1 group to 5,363.57 mg in Q4 group. Intakes of cereals/grains, potatoes/starches, legumes, seeds/nuts, vegetables, mushrooms, fruits, meat, fishes/shell fishes, milks/dairy products, oils/fats, and seasonings among all foods significantly increased from Q1 group to Q4 group. Lastly, in the multivariable regression analysis, male, higher age, married, eating breakfast, consumption of snacks, prepared meals from home/institution, average eating-out frequency per week, energy consumption, and sodium intake related parameters increased intake of Korean soup and stew. Conclusion: Excessive intake of sodium was related to high blood pressure and metabolic syndrome. Thus, there are needs to improve dietary guidelines and nutrition education for balanced intake of soup and stew.