• Applied Chemistry for Engineering
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• 제34권5호
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• pp.493-500
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• 2023

In this study, we developed an impedance sensor capable of controlling electrode polarization by coating iridium oxide (IrO_x) on the surface of the screen-printed carbon electrode. IrO_x was deposited on the surface of carbon electrodes according to the number of cycles (0~50 cycles) by cyclic voltammetry. Observation of scanning electron microscope images revealed that the size and number of IrO_x particles increased as the number of cycles increased. The changes in impedance responses as a function of the NaCl concentration of the as-obtained sensors were investigated using electrochemical impedance spectroscopy. The sensors manufactured in 50 cycles exhibited the best coefficient of determination and reproducibility, attributed to the well-controlled electrode polarization. We further demonstrated the usefulness of the IrO_x-based sensor as a diagnosis sensor for dry eye syndrome by comparing the results of the commercially available osmometer and our sensor using actual solution samples.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• 제17권4호
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• pp.419-427
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• 2019

The application of ion crystallization technology was considered as a way to increase the operating efficiency and improve the operating performance of a liquid waste management system (LWMS) in the Advanced Power Reactor 1400 (APR 1400). Although ion crystallization technology has not been practically applied to Nuclear Power Plants (NPPs) until now, a previous experimental study demonstrated that it is possible to selectively remove at least 95% of various nuclide ions present in the liquid radioactive waste of NPPs. We reviewed the possibility of applying ion crystallization technology to the existing LWMS by applying the nuclide removal rate of ion crystallization technology and prepared a way to improve the existing LWMS in the APR 1400. Furthermore, we determined the optimized application location of ion crystallization technology in the existing LWMS by considering decontamination characteristics of the ion crystallization technology and the existing LWMS design features and operating experiences. The application of ion crystallization technology to the liquid waste collection tank, where liquid radioactive materials are collected, will have the least impact on the existing design while providing the greatest improvement. It is expected that the application of ion crystallization technology to the current APR 1400 or new NPPs would increase the operating efficiency of the LWMS and result in an improvement of system performance.

• The Korean Journal of Ecology
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• 제25권3호
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• pp.171-177
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• 2002

Three species of Chenopodiaceae, i.e. Suaeda japonica, Salicomia herbacea, Beta vulgaris var. cicla, were investigated to compare the physiological characteristics through ionic balances and osmoregulations under different environmental salt gradients. Plants were harvested in two weeks from treatments with salt gradients(0, 50, 100, 200 and 400 mM NaCl) and mineral nutrition gradients(1/1, l/5, 1/10 dilutions of Hoagland solution). Plants were analyzed for growth responses, ionic balances, osmolalities, conductivities, glycinebetaine and proline contents quantitatively. Three plants of Chenopodiaceae accumulated salts into tissues unlike some salt sensitive species, and showed unique adaptation patterns to overcome saline environments, i.e. strong growth stimulation for Salicomia herbacea, growth negative tolerance for Suaeda japonica, and growth positive tolerance for Beta vulgaris var cicla. The absorption of inorganic $Ca^{2+}$ ions was inhibited remarkably due to the excess uptake of $Na^+$ with increasing salinity. The $K^+$ content in plants was significantly reduced with increasing salinity. Total nitrogen content was reduced as mineral nutritions and salinity increases. Conductivity and osmolality increased with increasing salinity regardless of mineral nutritions. The ranges of glycinebetaine and proline contents were $0.2{\sim}2.5{\mu}M/g$ plant water and $0.1{\sim}0.6{\mu}M/g$ plant water, respectively.

• Journal of the Korean Applied Science and Technology
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• 제33권4호
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• pp.795-801
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• 2016

This study is on the denitrification process using the sodium alginate and $CaCl_2$ as a flocculant. Removal techniques of nitrate nitrogen from waste water are reverse osmosis, ion exchange, electro dialysis and biological method etc. We tried to remove nitrate nitrogen with flocculation and sedimentation method in the present study. Calcium alginate is expected to form a chelate bond with nitrate nitrogen in the solution. So the effects of flocculantt component, flocculation reaction time, molar ratio of the flocculant, flocculant injection rate are studied to determine the best removal rate of nitrate nitrogen. In addition, we tried to determine the nitrate nitrogen removal mechanism by analyzing the structure and component ratio of the configuration after the agglutination precipitate by FE-SEM and EDS. As a result, the nitrate nitrogen removal mechanism is turned out to form calcium-nitro-alginate, and the best mole ratio of flocculating agent is 1 : 1, the injection rate of the flocculant was up to 2%, the removal rate of the nitrate nitrogen to be 56.7% in the synthetic wastewater.

• Membrane Journal
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• 제34권2호
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• pp.87-95
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• 2024

Recent studies explore a wide array of desalination and water treatment methods, encompassing membrane processes such as reverse osmosis (RO), nanofiltration (NF), and electrodialysis (ED) to advanced capacitive deionization (CDI) and its membrane variant (MCDI). Comparative analyses reveal ED's cost-effectiveness in low-salinity scenarios, while hybrid systems (NF-MCDI, RO-NF-MCDI) show improved salt removal and energy efficiency. Novel ion separation methods (NF-CDI, NF-FCDI) offer enhanced efficacy and energy savings. These studies also highlight the efficiency of these methods in treating complex wastewater specific to various industries. Environmental impact assessments emphasize the need for sustainability in system selection. Additionally, the integration of microfabricated sensors into membranes allows real-time monitoring, advancing technology development. These studies underscore the variety and promise of emerging desalination and water treatment technologies. They provide valuable insights for enhancing efficiency, minimizing energy usage, tackling industry-specific issues, and innovating to surpass conventional method limitations. The future of sustainable water treatment appears bright, with continual advancements focused on improving efficiency, minimizing environmental impact, and ensuring adaptability across diverse applications.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.663-666
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• 2015

In this research, botanical extracts containing green tea, Saururus chinensis and Prunus padus were tested to see possibility as shampoo. Leaves of Green tea and Saururus chinensis were extracted with hot water. Prunus padus bark extract was applied reverse osmosis and ultrasonic extraction. When interfacial tension was measured among shampoo including botanical extracts, Sodium dodecylsulfate(SDS) and Quillaja Bark Saponin(QBS), that of shampoo was lower than that of SDS and QBS at lower concentration, however, it showed similar interfacial tension at 100% concentration. Shampoo showed moderate antimicrobial activity in Staphylococcus aureus and Candida albicans. Botanical extract did not indicate cell toxicity up to $350{\mu}g/ml$ concentration in MTT assay. Shampoo containing botanical extract was stable for 3 months, however, it showed considerable variation in pH and viscosity. In conclusion, shampoo containing botanical extract shows strong possibility for natural shampoo if the formulation is modified.

• Clinical and Experimental Pediatrics
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• 제48권2호
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• pp.148-153
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• 2005

Purpose : The aim of this study was to determine the reference ranges of serum albumin levels depending on the gestational ages of preterm infants. We also intended to compare the mean serum albumin levels between groups of preterm infants that did not develop clinical disorders later, and groups that did develop clinical disorders such as respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity, apnea and bronchopulmonary dysplasia. We also examined the significance of serum albumin as a predictor for the development of clinical disorders. Methods : The records of 208 neonates with gestational ages from 23 weeks to 41 weeks were reviewed retrospectively. The mean albumin concentrations with reference ranges by gestational ages were determined. Statistics for each two of group were compared. Logistic regression analysis was used to model odd ratio, and 95 percent confidence interval as a mean of the association between predictors and outcome. Results : Serum albumin levels were at 23-24 weeks gestation was 2.36 g/dL, rising to 3.43 g/dL in full term babies. There were significant mean differences between the clinical groups and control groups for each clinical disorder such as respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity and apnea in premature babies of 30-36 weeks of gestation. Low serum albumin appeared to be associated with increased risks of clinical disorders. Conclusion : The normal serum albumin levels in preterm infants should be defined according to the gestational ages. Lower albumin levels increase the risks of the later development of clinical disorders, which are common in premature infants.

• Korean Journal of Soil Science and Fertilizer
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• 제9권1호
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• pp.33-38
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• 1976

As a basic studies for increasing food production utilizing sandy barren lands and sandy farmlands of low productivity which distributed widely in Korea, an experiment of growing rice-plant on sandy barren land was undertaken as follows. 1. Variety, IR-667 was adopted and the growing method was a nutrient-irrigation culture which aimed to minimize percolation loss in sand with an automatic contineous supplying nutrient solution for supplmenting the sand characteristics. 2. The growth type price-plant after heading was a typical higher yield plant, that is, numerous, small, narrow, and thickend leaves, straight attitute, dense fasciculated etc. though the rooting of plant after planting was delayed because of using paddy-field grown seedling. 3. The adaptability of rice-plants on sandy land seemed to be different by varieties and IR-667 was more adaptable than ordinary Japonica varieties. 4. Even at the period of heading and maturing, the root system of rice-plant grown on sand showed vigorous growth having more activated apical portions. while, even the lower leaves showed flourished state. 5. The suppling of calcium and magnecium in addition to nitrogen, phosphorus and potassium on sand made notable increase of stem number per plant, grain number per stem and yields.

• Parasites, Hosts and Diseases
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• 제30권2호
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• pp.133-140
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• 1992

Theileria sergenti were isolated from infected erythrocytes by hypotonic Iysis, and soluble meroBoite antigens were purified by sonication and differential centrifugation. The preparation contained 29, 34, 35 and 105 kD immuno-dominant polypeptides. The soluble antigens (0.5 mg/ml) were prepared and fortified with Freund's adjuvant. Five month old naive Korean calves were subcutaneously inoculated with the preparation and a booster dose was administered 4 weeks later Nine weeks after the booster dose, vaccinates and controls were challenged with a homologous stabilate (5.6×106 RBC/dose, 40% Parasitemia). All animals were monitored for hematocrit, total erythrocyte count, parasitemia and for the specific antibody by Western immuno- blot (WB) and indirect immuno-auorescent antibody(IFA) test. By 18 weeks after vaccination (6 weeks after the challenge), vaccinated cattle had an average IFA titer of 1 : 10,240 compared with 1 : 1,280 of the controls. The vaccinates showed ne91igib1e change in hematocrit and total RBC count whereas control animals showed significant (P<0.05) hematological chanties and associated anemia. After vaccination and challenge, the antibody responses demonstrated that vaccination had induced significant production of antibody to the 29 and 35 kD polypeptides. The latter polypeptide was much more strongly recognized by the vaccinated animals, and thus it may be a potential candidate for the vaccine.

• Journal of Plant Biotechnology
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• 제44권3호
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• pp.296-302
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• 2017

Rice (Oryza sativa) cultivars show an impairment of growth and development in response to abiotic stresses such as drought, salinity, heat and cold at the early seedling stage. The tolerance to heat stress in plants has been genetically modulated by the overexpression of heat shock transcription factor genes or proteins. In addition to a high temperature-tolerance that has also been altered by elevating levels of osmolytes, increasing levels of cell detoxification enzymes and through altering membrane fluidity. To examine the heat tolerance in transgenic rice plants, three OsOPT10 overexpressing lines were characterized through a physiological analysis, which examined factors such as the electrolyte leakage (EL), soluble sugar and proline contents. We further functionally characterized the OsOPT10 gene and found that heat induced the expression of OsOPT10 and P5CS gene related proline biosynthesis. It has been suggested that the expression of OsOPT10 led to elevated heat tolerance in transgenic lines.