• Korean Journal of Materials Research
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• v.22 no.12
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• pp.696-700
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• 2012

(Na, K) $NbO_3$ thick film was successfully achieved using a sol-gel coating process with the addition of polyvinylpyrrolidone (PVP) to a metal alkoxide solution. The transparent coating solution, mixed with Nb:PVP = 1:1 in a molar ration, was synthesized by evaporating the solvent to over 62.5 wt%. Additive PVP increased the viscosity of the solution so that the coating thickness could be enhanced. The thickness of the (Na, K) $NbO_3$ film assisted by PVP was ca. 320 nm at the time of deposition; this value is four times thicker than that of the sample fabricated without PVP. Also, due to PVP binding with the OH groups of the metal alkoxide, the condensation reaction in the film was suppressed. The crystalline size of the (Na, K) $NbO_3$ films assisted by PVP was ca. 15 nm smaller than that of the film fabricated without PVP. After the sintering process at $700^{\circ}C$, the (Na, K) $NbO_3$ films were mainly composed of randomly oriented (Na, K) $NbO_3$ phase of perovskite crystal structure, including a somewhat secondary phase of $K_2Nb_4O_{11}$. However, by adding PVP, the content of the secondary phase became quite smaller than that of the sample without PVP. It was thought that the addition of PVP might have the effect of restraining the loss of potassium and that PVP could hold metalloxane by strong hydrogen bonding before complete decomposition. Therefore, the film thickness of the (Na, K) $NbO_3$ films could be considerably advanced and made more crack-free by the addition of PVP.

• Journal of the Korean Ceramic Society
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• v.22 no.1
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• pp.35-39
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• 1985

Synthetic mica $NaMg_{2.5}(Si_4O_{10})F_2 (Na-TSM)$ was treated with HCl solution and H-type exchange resin to investigate the chemical stability and the ion exchange by measuring the dissolution of chemical components and the exchanged $H^+$ ion. The replacement of $Na^+$ ion occurred in contact with HCl solution and H-type ion exchange resin at the surface of Na-TSM particles reached $Na^+$ ions at maximum value of 70~80%. $Mg^{2+}$ ion of octahedral layer became to dissolve from the pH2 solution and th amount of it dissolved in-creased almost proportional to $H^+$ ion concentration from around 0.02N $H^+$ ion equilibrium concentration. The crystalline structure of Na-TSM was destructed by dissolution of Mg2+ ion in cncentrated hydrochloric acid solution and resulted silica gel precipitation.

• Korean Journal of Plant Resources
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• v.16 no.2
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• pp.141-146
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• 2003

To improve the percentage of field germination of Zanthoxytum piperitum DC., storage in ground(control) and several chemicals as treatments was investigated. Germination percentage was 30.3 and 22.7% in GA$_3$(100 ppm) and NaCIO(10%), respectively compared with 17.3％ in storage in ground without treatments. Germination percentage reached maximum between 26 and 33 days after seeding and then increased slowly. Top/Root ratio was the highest at storage in ground after the treatment of GA$_3$ 100ppm.

• Development and Reproduction
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• v.22 no.4
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• pp.319-329
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• 2018

The experiment was conducted for 210 days to determine the effect of feeding, and starvation, and exposure to sodium nitrite ($NaNO_2$) on the survival, physiological changes, hematological parameter, and stress response of Far Eastern catfish, Silurus asotus. The survival of the starved group was lower than that of the fed group during the experiment. Starvation resulted in retardation of growth, which provides an example of fish that failed to continue to grow and remain in a good condition. Blood analyses (cortisol and glucose) showed significant differences of stress response between the fed and starved groups exposed to $NaNO_2$ at the conclusion of the experiment (p<0.05). These results suggest that all nutritional parameters used for starvation and feeding with $NaNO_2$ stress in this experiment appear to be a useful index of nutritional status in Far Eastern catfish.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.177-183
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• 2008

Sodium is known to reduce a plant growth and yields. However, the relationships between physiological response of seedling and salinity stress caused by growing media are not well understood yet. We conducted experiments to investigate change of some parameters including Na, EC, moisture content in media under different air temperature ($15^{\circ}C$, $25^{\circ}C$), and the response of fruit-vegetables such as cucumber, oriental melon on saline conditions originated from horticultural substrate. Volumetric moisture content of media at $15^{\circ}C$ was 70%, but at $25^{\circ}C$ was decreased by 45% within 22 hrs, showing below optimal matric potential, approximately. During reaction time, the increase of Na concentration was significantly greater in saline substrate than in control. The decrease rate of Na concentration according to supplying irrigation water was higher in saline substrate than in control. $CO_2$ assimilation rate and transpiration rate of Korea melon grown in low temperature were decreased with a Na/cation ratio in hydroponic solution. Water saturation deficit was also increased significantly at $15^{\circ}C$ as compare to $25^{\circ}C$. Saline stress during nursery stage induced a reduction of seedling quality, growth and cucumber yield. The results suggest that the relationship between uncontrolled Na uptake of seedling from saline substrate and meteological condition is responsible for saline stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.995-1002
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• 2000

In order to Develop a low Na functional kimchi using sea tangle, the Na-binding capacity of alginate in sea tangle along with other dietary fibers was evaluated in vitro. The adding type and amount of the sea tangle that contains alginate in kimhi and characteristics of the sea tangle added kimchi were also studied. Na-binding capacity of various dietary fibers such as cellulose, pectin, gun gum, carageenan, alginates (sodium alginate, alginate, alginate from sea tangle) was measured by equilibrium dialysis method in pH 2 and pH 7 in vitro. Gua gum, carageenan and a group of alginates effectively bound to Na+ Espacially sodium alginate showed high Na-binding capacity of 29.2% in pH of stomach (pH 2.0) and 33.8% in pH of small intestine (pH 7.0), however, the alginate extracted from sea tangle could not bind Na in PH of stomach (pH 2.0), but 27.4% in pH of small intestine (pH 7.0) condition. The content of alginate in sea tangles (dried sea tangle, salted sea tangle and washed salted sea tangle) was 19.8 ~ 22.2% on dry matter basis. The sea tangle added kimchi was prepared with the addition of the flake type (0.5$\times$3 cm) of sea tangle with a quantity of 30% in kimchi from the data of the sensory analysis. The addition of the sea tangle to the kimchi increased the content of soluble dietary fiber, suggesting the Na-binding capacity increased. The sea tangle added kimchi (SK) and sea tangle and fermented anchovy added kimchi (SAK) showed higher levels of reducing sugar and acidity than the control kimchi (CK). In quantitative descriptive analysis (QDA) SK and SAK showed higher score in overall acceptance, and lower score in acidic order than CK, however, SK showed less moldy taste and more fresh acidic taste than SAK.

• Journal of the Korean Ceramic Society
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• v.32 no.11
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• pp.1292-1300
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• 1995

The ionic conductivity of NASICON solid electrolytes was simulated by using Monte Carlo Method (MCM). There were included two conduction paths: (1) Na1-Na2 and (2) Na1-Na2 including Na2-Na2. We assumed that mid-Na ions provde an additional driving force for Na mobile ions due to the interionic repulsion between Na1 and Na2 ions. The inflection point of vacancy availability factor, V has been shown at nearby x=2, the maximum mid-Na ions. The inflection point of vacancy availability factor, V has been shown at nearby x=2, the maximum mid-Na sites are occupied. The effective jump frequency factor, V has been shown at nearby x=2, the maximum mid-Na sites are occupied. The effective jump frequency factor, W increased rapidly with the composition at low temperature, but decreased at high temperature region. On Na1-Na2 conduction path, the minimum of charge correlation factor, fc and the maximum of $\sigma$T were appeared at x=2.0. this indicated that mid-Na ions affect on the high ionic conductivity behavior. At the whole range of NASICON composition, 1n $\sigma$T vs. 1/T* plots have been shown Arrhenius behavior but 1n (VWFc) vs. 1/T* have been shown the Arrhenius type tendency at x=2, which mid-Na is being the maximum. The results of MCM agreed with the experimental one when the chosen saddle point value was 6$\varepsilon$ : 3$\varepsilon$. Here the calculated characteristic parameter of materials, K and the phase transition temperature were -4.001$\times$103 and 178$^{\circ}C$ (1/T*=1.92, 1000/T=2.22), respectively.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.1
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• pp.67-74
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• 1995

The aim of this study was to investigate the interrelationship among urinary excretion dietary habit of Na, Ca intake and hormonal factors in 22 hypertensive and 30 normotensive hospitalized patients. The results were summarized as follows : 1. Urinary excretion of Na in normotensive patients was not significantly different from that of hypertensive patients, while Ca excretion(as expressed on the basis of mg of creatinine) was significantly higher in hypertensive patients. 2. Habitual dietary intake of Na, Ca in hypertensive patients were not significantly different from those of normotensive patients. 3. There were no significant differences in mean plasma renin activity, aldosterone and parathyroid hormone(PTH) level between two groups. However, systolic pressure significantly correlated with PTH(r=0.2597) and aldosterone level(r=0.24648)(P<0.05). In this study blood pressure did not show any significant relationship between urinary Na excretion and habitual dietary Na intake of Na. It is speculated that individual difference of Na sensitivity might result in heterogenous blood pressure response to dietary Na intake. Higher Ca excretion in hypertensive subjects suggested a future study on the interrelationship between Ca metabolism and aldosterone system in hypertension.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.90-94
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• 1976

The amounts of volatile fatty acid and carbon dioxide of different salt Kimchis (1.02% NaCl, 3.16% NaCl) and Kimchis fermented at different temperature were determined. After the extraction of the acids with 80% ethanol it was steam-distillated. Identification and quantitative determination of individual acids were performed by gas chromatography and paper chromatography. Carbon dioxide contents were measured by microdiffusion method. Formic and acetic acid were found in four Kimchis. The acetic acid content of 1.02% NaCl Kimchi and Kimchi fermented at $4-5^{\circ}C$ were very high and their carbon dioxide contents were also high. Fifteen taste panels scored 1.02% NaCl Kimchi higher than 3.16% NaCl Kimchi and Kimchi fermented at $4-5^{\circ}C$ higher than Kimchi fermented at $20-22^{\circ}C$. It is assumed that large amounts of acetic acid and carbon dioxide make Kimchi flavorful.

• Journal of Life Science
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• v.9 no.1
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• pp.22-25
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• 1999

In order to study the mechanism for the adaptation to salt stress, we mutagenized budding yeast Saccharomyces cerevisiae with Ethylmethane sulfonate, and isolated salt-tolerant mutants. Among the salt-tolerant mutants, two strains exhibit additional temperature sensitive phenotype. Here, we report that these two salt-tolerant mutants are specific to {TEX}$Na^{+}${/TEX} rather than general osmotic stress. These mutant strains may contain mutations in the genes involved in {TEX}$Na^{+}${/TEX} home-ostasis.