• 한국표면공학회지
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• 제37권2호
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• pp.86-91
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• 2004

Effect of potassium formate, glycine and oxalic acid in a sulfate solution on the deposit composition and current efficiency of trivalent chromium plating was studied. The trivalent chromium layers prepared by solutions with potassium formate, glycine and oxalic acid contain a few carbon inside. The solutions containing potassium formate, glycine and oxalic acid are relatively stable with pH change. The solution with the potassium formate shows 6-30％ current efficiency with current density, whereas, the solutions with oxalic acid and glycine show about 5％ current efficiency, respectively. The improved current efficiency is related to enough supply of chromium ions to the electrode due to the increase of pH at the front of electrode.

• Molecules and Cells
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• 제37권8호
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• pp.575-584
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• 2014

Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.

• 대한화학회지
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• 제17권5호
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• pp.378-384
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• 1973

요오드화칼륨으로부터 요오드산칼륨까지의 양극산화시 그 반응의 내용을 검토키 위하여 전착과산화납 및 백금양극을 사용하여 각종 농도의 요오드화칼륨 수용액중에서 분극곡선을 측정한 결과 요오드화칼륨의 1.5M이하에서 한계전류가 존재하며 0.1M의 수산화칼륨을 가하였을때는 한계전류는 나타나지 않음을 알았다. 한편 백금양극의 경우에는 과산화납양극에서와 같이 희박한 요오드화 칼륨수용액중에서 한계전류가 나타나지 않으며 이는 과산화납양극표면에서 $PbO_2+2I^{-}+2H^+{\to}PbO+I_2+H_{2}O$와 같은 화학반응에 기인함을 알았다. 무격막전해조를 사용하여 요오드화염으로부터 요오드산염까지의 전해제조시 가장 효율적인 전해조건에 관하여서도 검토한 결과, (a)환원방지제인 중크롬산칼륨의 첨가는 0.1g/l의 농도가 적당하였으며, (b)전해온도는 전류효율에 큰 영향을 미치지 않았으며, (c)전류밀도가 증가함에 따라 전류효율은 상승하였고, (d)전해중 전해액의 액성은 약알카리성이 가장 효율적이었다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권2호
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• pp.73-77
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• 2003

The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy (UL) were studied. Sprague-Dawley male rats, treated with nitric oxide liberating agent sodium nitroprusside (SNP) and NOS inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME), were subjected to destruction of the unilateral vestibular apparatus, and then spontaneous nystagmus was observed in the rat. To explore the effects of nitric oxide on the neuronal excitability, whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus in SNP treated rats was lesser than that of spontaneous nystagmus in control animals. In contrast, pre-UL treatment with L-NAME resulted in a significant increase in spontaneous nystagmus frequency. In addition, SNP increased the frequency of spontaneous action potential in isolated medial vestibular nuclear neurons. Potassium currents of the vestibular nuclear neurons were inhibited by SNP. After blockade of calcium dependent potassium currents by high EGTA (11 mM) in a pipette solution, SNP did not inhibit outward potassium currents. 1H-[1,2,4] oxadiazolo [4,3-a] quinozalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, inhibited the effects of SNP on the spontaneous firing and the potassium current. These results suggest that nitric oxide after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cGMP, and consequently would increase excitability in ipsilateral vestibular nuclear neurons.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.787-791
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• 2004

We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that car be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, ther nal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2711-2716
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• 2014

The high content of potassium in molasses limits its usage as a raw material for stock feed. Moreover, its high viscosity makes it difficult to develop an efficient removal process. In this study, ion exchange and solvent extraction experiments have been performed to investigate the removal of potassium from a mixture of molasses with water. Cationic exchange resins (AG50W-X8 and Diphonix) showed a high loading percentage of potassium but the occurrence of breakthrough in few bed volumes was a drawback to the industrial application. Among the cationic extractants (D2EHPA, PC 88A, Cyanex 272) tested in this study, saponified PC 88A was found to be the best extractant for the removal of potassium. Batch simulation studies on a three stage counter current extraction confirmed that 85% of potassium was removed from 50 wt % molasses solution in water by using saponifed PC 88A.

• Transactions on Electrical and Electronic Materials
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• 제15권2호
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• pp.60-65
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• 2014

This article explains the experimental results of ferroelectric polarization switching (FPS) of potassium nitrate ($KNO_3$) with different polymers such as polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) using simple melt-press techniques. To analyze the ferroelectric polarization switching in potassium nitrate ($KNO_3$) composite films at room temperature, we applied the Ishibashi and Takagi theory (based on Avrami model) to the switching current transient. To investigate the dimensionality of domain growth, the ferroelectric polarization switching current (FPS current) was observed from the square - wave bipolar signals across a resistance of $0.1k{\Omega}$ in series with the composite films. The existence of a switching current transient pulse confirmed the ferroelectricity and indicated the stability of the ferroelectric phase (phase III) of $KNO_3$ at room temperature. Polarization hysteresis (P-E) characteristics supported the prominent features of ferroelectric polarization switching in the composite films at room temperature.

• 대한의생명과학회지
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• 제16권4호
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• pp.259-264
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• 2010

This study was designed to investigate the effects of nitric oxide on the neuronal activity of rat cerebellar Purkinje cells. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated Purkinje cells were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium current were recorded by standard patch-clamp techniques under current and voltage-clamp modes respectively. 15 Purkinje cells revealed excitatory responses to $20\;{\mu}M$ of sodium nitroprusside (SNP) and 4 neurons (20%) did not respond to SNP. Whole potassium currents of Purkinje cells were decreased by SNP (n=10). Whole potassium currents of Purkinje cells were also decreased by L-arginine, substrate of nitric oxide (n=10). These experimental results suggest that nitric oxide increases the neuronal activity of Purkinje cells by altering the resting membrane potential and after hyperpolarization.

• Nutritional Sciences
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• 제2권2호
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• pp.76-81
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• 1999

Sodium restricted diets are known to lower blood pressure in salt sensitive, hypertensive patients. Thare is increasing evidence that potassium plays an important role as a protective factor in the regulation of blood pressure. The objective of the current study was to measure parameters of sodium, potassium, and chloride utilization as affected by feeding of substantial quantities of bread made from whole ground white torn meal, whole ground yellow corn meal, and whole ground wheat flour. The breads provided 40 percent of a caloric content of the constant, measured laboratory diet. The 28-day study was divided into an introductory period of 7-days and three experimental periods of 7-days each. Order of assignment to specific treatments for 12 healthy subjects were according to a complete randomized block design. Yellow corn bread diets resulted in the highest potassium retention (243 mg/day) and the lowest urinary sodium and potassium ratio (1.53 $\pm$ 0.26) numerically in comparison to the other test breads. The excretions of sodium and chloride were higher during controlled feeding periods than during the self-selected diet period(p < 0.05). This indicates a response to the higher intake of these electrolytes from the experimental diets than from self-selected diets. There was no significant difference in the effect of white corn bread, yellow corn bread, or whole wheat bread diet on electrolyte status in humans. However, the yellow corn bread diet resulted in a somewhat more favorable urina교 sodium to potassium ratio than that from white corn bread or whole wheat bread diet.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.236-243
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• 2017

A fixed-bed zinc/nickel redox flow battery (RFB) is designed and developed. The proposed cell has been established in the form of a fixed bed RFB. The zinc electrode is immersed in an aqueous NaOH solution (anolyte solution) and the nickel electrode is immersed in the catholyte solution which is a mixture of potassium ferrocyanide, potassium ferricyanide and sodium hydroxide as the supporting electrolyte. In the present work, the electrode area has been maximized to $1500cm^2$ to enforce an increase in the energy efficiency up to 77.02% at a current density $0.06mA/cm^2$ using a flow rate $35cm^3/s$, a concentration of the anolyte solution is $1.5mol\;L^{-1}$ NaOH and the catholyte solution is $1.5mol\;L^{-1}$ NaOH as a supporting electrolyte mixed with $0.2mol\;L^{-1}$ equimolar of potassium ferrocyanide and potassium ferricyanide. The outlined results from this study are described on the basis of battery performance with respect to the current density, velocity in different electrolytes conditions, energy efficiency, voltage efficiency and power of the battery.