• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.277-284
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• 1998

The raw food waste of Korea contained markedly high sodium chloride and such high sodium chloride concentration in the soil is a factor limiting plant growth and impairing soil physicochemical properties. This study was carried out to assess the effect of NaCl-containing compost on the growth of lettuce(Lactuca satjva L.) and on the soil chemical properties. For the experiment, six treatments applying 0, 0.5, 1, 3, 6, and 9% NaCl-containing composts at the rate of $20Mg\;ha^{-1}$ were conducted established in a greenhouse. Growth measurements, chemical analysis of lettuce foliage, and soil chemical properties after the harvest were investigated. Lettuce yield in the treatments applied to composts over 3% NaCl was gradually reduced and mortality of lettuce as well as Na concent ration of lettuce foliage progressively increased with successively higher NaCl concentration of composts. With an increase of NaCl concentration of composts, the values of ESP and exchangeable sodium concentration in the surface soil were significantly increased. Especially, ESP of surface soil in the treatment incorporated with 9% NaCl-containing compost after the harvest attained by about 15, suggesting that sodification of surface soil under a greenhouse condition can occur when the compost over 9% NaCl is applied to soil. In conclusion, the application of over 3% NaCl-containing compost at the rates of $20Mg\;ha^{-1}$ can cause undesirable influences in plant growth and also the treatments of over 6% NaCl-containing composts can create conspicuous deteriorations in soil chemical properties in the current year.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.457-467
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• 2022

Electron bombardment to silicate glass during electron probe microanalysis (EPMA) causes outward migration of Na from the excitation volume and subsequent decrease in the measured X-ray count rates of Na. To acquire precise Na₂O content of silicate glass, one should use proper analytical technique to avoid or minimize Na migration effect or should correct for decreases in the measured Na X-ray counts. In this study, we analyzed 8 silicate glass standard samples using automated Time Dependent Intensity (TDI) correction method of Probe for EPMA software that can calculate zero-time intercept by extrapolating X-ray count changes over analysis time. We evaluated an accuracy of TDI correction for Na measurements of silicate glasses with EPMA at 15 kV acceleration voltage and 20 nA probe current electron beam, which is commonly utilized analytical condition for geological samples. Results show that Na loss can be avoided with 20 ㎛-sized large beam (<0.1 nA/㎛²), thus silicate glasses can be analyzed without TDI correction. When the beam size is smaller than 10 ㎛, Na loss results in large relative errors up to -55% of Na₂O values without correction. By applying TDI corrections, we can acquire Na₂O values close to the reference values with relative errors of ~ ±10%. Use of weighted linear-fit can reduce relative errors down to ±6%. Thus, quantitative analysis of silicate glasses with EPMA is required for TDI correction for alkali elements such as Na and K.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.83-90
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• 1998

Stage transformation characteristics of Li, K and Na-graphite deintercalation compounds (GDICs) were studied under consideration of a deintercalation mechanism of the intercalants between carbon layers. Li-graphite intercalation compounds (GICs) synthesized by a controlling temperatures and pressures have been spontaneously decomposed in the atmosphere. By X-ray differaction analysis the $d_{001}$-values of stage 1 and 2 were identified to be 3.71 and 7.06 $\AA$, respectively. After 6 weeks, the deintercalation reaction of the Li-GICs ceased and only residual compounds could be observed. K-GICs were synthesized by the modified two-bulb method resulting in structural stabilities and stage transitions. By X-ray diffraction analysis the very stable K-graphite residue compounds were observed after 10 weeks. Na-GICs with stage 1 and 2 were synthesized using the high temperature and pressure technique. The temperature dependence of a deintercalation reaction and a thermal stability of Na-GICs were discussed. The structure changes of the Na-GDICs depending on heating rates were identified by X-ray diffraction. According to the deintercalation process, the stage transformations could be attributed to irregular deintercalations of the GDICs with disordered stage.

• ALGAE
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• v.28 no.2
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• pp.173-183
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• 2013

Sodium hypochlorite (NaOCl) is widely used to disinfect seawater in power plant cooling systems in order to reduce biofouling, and in ballast water treatment systems to prevent transport of exotic marine species. While the toxicity of NaOCl is expected to increase by ongoing ocean acidification, and many experimental studies have shown how algal calcification, photosynthesis and growth respond to ocean acidification, no studies have investigated the relationship between NaOCl toxicity and increased $CO_2$. Therefore, we investigated whether the impacts of NaOCl on survival, chlorophyll a (Chl-a), and effective quantum yield in three marine phytoplankton belonging to different taxonomic classes are increased under high $CO_2$ levels. Our results show that all biological parameters of the three species decreased under increasing NaOCl concentration, but increasing $CO_2$ concentration alone (from 450 to 715 ${\mu}atm$) had no effect on any of these parameters in the organisms. However, due to the synergistic effects between NaOCl and $CO_2$, the survival and Chl-a content in two of the species, Thalassiosira eccentrica and Heterosigma akashiwo, were significantly reduced under high $CO_2$ when NaOCl was also elevated. The results show that combined exposure to high $CO_2$ and NaOCl results in increasing toxicity of NaOCl in some marine phytoplankton. Consequently, greater caution with use of NaOCl will be required, as its use is widespread in coastal waters.

• Korean Journal of Pharmacognosy
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• v.16 no.2
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• pp.93-98
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• 1985

This investigation was performed to study the effect of Ginseng water extract on the cardiac sarcolemma $Na^+,\;K^+-ATPase$ activity of rat hearts. The Ginseng water extract (100mg/kg/day) was administered orally to Sprague-Dawley rats for one, four and seven days. The fragment of sarcolemma was prepared by the method of Matsui and Erdmann and the $Na^+,\;K^+-ATPase$ and $Mg^{++}-ATPase$ activity were measured by the method of Martins and Doty. $Na^+,\;K^+-ATPase$ activity in the rat heart treated with Ginseng water extract for 1 day was not significantly different from control value, but the activity was decreased by 13.4% in the rat heart treated for 4 days and was decreased by 20.4% in the 7 days treated group. $Mg^{++}-ATPase$ activity in the rat treated with ginseng water extract was similar to control value. It may be concluded that chronic administration of Ginseng may inhibit the $Na^+,\;K^+-ATPase$ enzyme activity, but single administration may not inhibit the activity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.8
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• pp.717-723
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• 2006

Lead free $(Na_{0.5}K_{0.47}Cd_x)NbO_3$ ceramics (x=0.015-0.005) were prepared by the conventional mixed oxide route. The effects of CdO addition on the sintering, dielectric and piezoelectric properties of the samples were examined. The addition of CdO greatly enhanced the sinterability of ceramics and the sample has a lower dielectric loss. The $k_p\;and\;Q_m$ of the samples with 0.02 mol CdO addition are 0.35 and 125, respectively, The $(Na,K)NbO_3$ ceramics show a large degradation of $k_p$ due to the deliquescence when exposed to humidity, while the $(Na,K,Cd)NbO_3$ ceramics have no a significant degradation of it.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.83-89
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• 2014

The aim of this study is to investigate the sorption/ion exchange of radioactive nuclides such as $Cs^+$ and $Sr^{2+}$ by synthetic Na-micas. In order to prepare Na-micas, two natural micas (phlogopite and biotite) were used as precursor materials. XRD, SEM, and EDS analyses were used to examine material characterization of synthetic Na-micas. Analyses of materials revealed that Na-micas were successfully obtained from natrual micas by K removal treatment. On the other hand, single solute (Cs or Sr) and bi-solute (Cs/Sr) sorption experiments were carried out to determine sorption capacity of Na-micas for Cs and Sr under different pH and ionic strength conditions. Uptake of Cs and Sr by micas in bi-solute system was lower than in single-solute system. Additionally, Langmuir and Langmuir competitive models were applied to describe sorption isotherm of Na-micas. bi-solute system was well described by Langmuir competitive models. For the results obtained in this study, Na-micas could be promising sorbents to treat multi-radioactive species from water and groundwater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.672-679
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• 1996

In order to examine the quality attributes of native-bee honey, proximate composition and mineral components were analysed by atomic absorption spectrometry, ion chromatography and high performance liquid chromatography. The analytical results showed that native-bee honey is higher in the contents of crude ash, crude protein and diastase activity than those of foreign-bee honey. The principal mineral components of honey were Ca, Mg, Na, K and Cl, which showed that almost all the mineral components were contained higher in the native-bee honey than the foreign-bee honey samples. When we calculated K/Na ratio, we could make a clear distinction between native-bee honey and foreign-bee honey. The K/Na ratio turned out to be more than 10 in 6 samples of native-bee honey, whereas the ratio of foreign-bee honey showed up less than 1.5 in all 3 samples.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.146-151
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• 2008

In this study, batch or semi-continuous reactions, introducing site-specific carboxylic acids in ${\beta}$-1,3-glucan structures, were performed to increase water solubility and gel forming ability, using TEMPO/hypobromite with or without NaBr as catalysts. Regio-selective carboxylic acid formations were determined with infrared (IR) and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopic analyses. The regio-selective reactions with and without NaBr gave oxidation yields of 92.5 and 85.6%, respectively, in the batch type, and yields of 93.9 and 86.4%, respectively, in the semi-continuous type. The reaction times in the batch and semi-continuous reactions without NaBr were delayed by 100 and 150%, respectively, as compared to those with NaBr. A combination of IR and $^{13}C$ NMR analyses were used to confirm the formation of carboxylic acids in ${\beta}$-1,3-glucan. From the batch reactions with and without NaBr, the water solubilities of oxidized products were 50.0 and 55.6%, respectively, and in the semi-continuous reactions they were 52.6 and 53.5%, respectively; while the water solubility of the native ${\beta}$-1,3-glucan was less than 1.0%. Finally, as compared to the native ${\beta}$-1,3-glucan, the gel forming ability of the reaction products was greatly increased irrespective of the presence of NaBr or the reaction type.

• Analytical Science and Technology
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• v.7 no.3
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• pp.271-276
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• 1994

A Na-cellulose adsorbent was prepared by treating Sigma S-5504 cellulose with 2M NaOH and examined the adsorption behavior between metal ions and Na-cellulose in aqueous solution with batch method. Considering ion exchange capacity of Na-cellulose, the adsorption ratio of the Na-cellulose to metals charge equivalent indicated that the adsorption result from ion exchanging between metal ions and Na-cellulose. The enthalpy for the metal adsorption on the Na-cellulose was calculated to -18kcal/mol, which value was compared to those of carboxymethylcellulose(CMC) and Dowex 50W-X8, these result suggested that the adsorption on Na-cellulose resulted from ion exchange adsorption.