• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.41-49
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• 2019

Probing the Na environments in Na silicate and aluminosilicate glasses is essential to the macroscopic properties of melts in the Earth. In particular, exploring the atomic structure of Na silicate and aluminosilicate glasses reveals Na-O distance, which plays an important role in transport properties of melts. Here we report the local environment around Na using $^{23}Na$ magic angle spinning (MAS) NMR. We also obtain $^{23}Na$ isotropic chemical shift (${\delta}_{iso}$) of Na silicate and aluminosilicate glasses with varying composition using Dmfit program. The Q mas 1/2 model simulates the experimental results with three simulated peaks while the CzSimple model simulates with one peak. The ${\delta}_{iso}$ decreases with increasing $SiO_2$ content in Na silicate and aluminosilicate glasses. The ${\delta}_{iso}$ increases with increasing $Na_2O$ content in Na-Ca silicate and Na aluminosilicate glasses when the $SiO_2$ content is fixed. Considering the ${\delta}_{iso}$ of Na aluminosilicate glasses available in the previous studies, together with the current simulation results, we confirm that the ${\delta}_{iso}$ has positive correlation with Al / (Al + Si). Those experimental results were reproduced better using Q mas 1/2 model. The disorder of Na in Na silicate and aluminosilicate glasses can be revealed through the simulation of 1D $^{23}Na$ MAS NMR spectra using Dmfit program in a short time.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.168-173
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• 1989

In this report two experiments were carried out. Vertical distribution of exchangeable potassium(K) of soil in the orchardgrass meadow was investigated‘ a and K leaching from soil was monitored under lysimeter condition throughout one year. The results obtained a are as follows; The difference in the exchangeable soil K content b between the soil layers was very small in K-zero plot of the orchard grass meadow, but it was significant in K¬h high plot (Experiment 1). T The volume of leached water from the Iysime ter was a about 471 liters/m2 during a year and the amount of leached water was influenced by the precipitation. D During the investigation the quantity of leached K was 2 22.3 g/$m^2$. About 40 % of the total K in a year leached out during the first two months, May and June, after the start of the experiment. On the other hand, leached K amounted to 13.2 g/$m^2$ (60 % of the total K leached) during the period of ten months from July, 1985 to A April, 1986, when forages were harvested from the soil o of the lysimeter (Experiment 2). From the above results, it was known that K leach¬i ing from grassland soil can be also occurred in consider¬a able amount when the growth stage of forage is not d developed or soil does not become solid on such a p period as immediately after grassland improvement or e establishment. However, unless the K leaching from soil s seems to be little under the condition of permanent g grassland ecosystem with higher grade of soil hardness a and possibly with compact density of forage plants.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.63-74
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• 2010

The present study was carried out to evaluate the effects of organic liquid fertilizer (OLFs) fertigation on the growth and fruit quality of hot pepper (Capsicum annuum L.) cv. 'Nokkwang (Seminis Korea)'. Treatments were given with control (chemical feritilzer), OLF I(fowl dropping : fish meal : soybean meal, 2:1:1), OLF II(fowl dropping : bone meal : soybean meal, 2:1:1), OLF III(fowl dropping : bone meal, 1:1), and OLF IV(fowl dropping : rice bran : soybean meal, 2:1:1). The composition ratio of OLF based on weight to weight. The pH and EC of OLFs according to different material and compositions ranged from 6.5 to 6.8, and from 2.91 to $3.69dS{\cdot}m^{-1}$, respectively. The C/N ratio was the highest as 5.75 in OLF Ⅳ, and there was no difference among the treatments in C/N ratio of the exception of OLF IV. In OLF IV total fruit weight was the highest as 1,558g per plant and total fruit number increased as 23.7% compared to control. The content of capsaicin in the ripened pepper increased with OLF I and II treatments, and decreased with OLF III and IV treatments compared to control of $662mg{\cdot}kg^{-1}$, but the soluble solid content was the highest with OLF IV treatment as $10.0^{\circ}Brix$.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.143-148
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• 1995

The competence of callus formation and plant regeneration from root derived callus was higher in japonica cultivars than those of Tongil-type cultivars of rice. A japonica type cultivars Yeongdeogbyeo, showed the highest capacity (13%) for plant regeneration from root calli of 6 cultivars tested. The callus induced from seed and root tissues maintained higher capacity for plant regeneration during 7 passages of subculture on N$_{6}$ solid media at 2-week intervals. The maximum frequency (2 x 10$^{5}$ mL) of round cells and their cell colonies showed about 24 days after suspension culture of root-derived callus in N$_{6}$ medium with lmg/L 2,4-D, 300mg/L casein hydrolysate, 10mM L-proline, 20g/L sucrose and 30g/L sorbitol. The frequency of somatic embryo formation in suspension cultures of root-derived callus increased with prolonged advance of subculture time from 30 to 90 days, but their regenerative capacities decreased.

• Korean Journal of Materials Research
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• v.12 no.12
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• pp.941-946
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• 2002

Both Cu and Cu-oxide nanopowders have great potential as conductive paste, solid lubricant, effective catalysts and super conducting materials because of their unique properties compared with those of commercial micro-sized ones. In this study, Cu and Cu-oxide nanopowders were prepared by Pulsed Wire Evaporation (PWE) method which has been very useful for producing nanometer-sized metal, alloy and ceramic powders. In this process, the metal wire is explosively converted into ultrafine particles under high electric pulse current (between $10^4$ and $10^{ 6}$ $A/mm^2$) within a micro second time. To prevent full oxidations of Cu powder, the surface of powder has been slightly passivated with thin CuO layer. X-ray diffraction analysis has shown that pure Cu nanopowders were obtained at $N_2$ atmosphere. As the oxygen partial pressure increased in $N_2$ atmosphere, the gradual phase transformation occurred from Cu to $Cu_2$O and finally CuO nanopowders. The spherical Cu nanopowders had a uniform size distribution of about 100nm in diameter. The Cu-oxide nanopowders were less than 70nm with sphere-like shape and their mean particle size was 54nm. Smaller size of Cu-oxide nanopowders compared with that of the Cu nanopowders results from the secondary explosion of Cu nanopowders at oxygen atmosphere. Thin passivated oxygen layer on the Cu surface has been proved by XPS and HRPD.

• Journal of Pharmaceutical Investigation
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• v.39 no.4
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• pp.309-314
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• 2009

An enzyme immunoassay (EIA) was validated for quantitation of cacitriol in human plasma. Calcitriol was immunoextracted with immunocapsules, which contain monoclonal antibodies to calcitriol linked to solid phase particles in suspension with a vitamin D binding protein inhibitor. Calcitrol was eluated and the eluates were evaporated under a gentle stream of nitrogen gas. The absorbance of analytes was determined using a microplate reader (reference wavelength 650 nm; measurement wavelength 450 nm). The method was specific and sensitive enough to detect as low as 6.5 pmol/L of calcitriol. Linear calibration range was 6.5-491 pmol/L with correlation coefficient greater than 0.99. The overall accuracy was in the range of 83.8 to 111.2% and precision C.V. (%) 0.99 to 8.47%. The recovery was approximately 100% and stability was confirmed during storage and sample preparation. The pharmacokinetic parameters were calculated by baseline subtraction because calcitriol is an endogenous material. Following oral dose of calcitriol, the mean AUC$_{24h}$ was 1038${\pm}$539 pmol/Lhr and C$_{max}$ of 128${\pm}$63.1 pmol/L was reached at 3.50${\pm}$1.07 hr. The mean t$_{1/2}$ of calcitriol was 5.13${\pm}$2.10 hr. The present EIA method was successfully applied to study bioavailability after oral administration of 2 ${\mu}$g of calcitriol in healthy Korean subjects.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.1
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• pp.38-43
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• 2003

Immature and mature embryos of 18 Korean wheat genotypes were cultured in vitro to develop an efficient method of callus formation and plant regeneration, and to compare the responses of both embryo cultures. Immature and mature embryos were placed on a solid agar medium containing the MS salts and vitamins, 30g/l maltose, 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), and amino acids. The developed calli were maintained on regeneration medium containing MS salts and B5 vitamins, 20 g/l sucrose, and the combination of two plant growth regulators, 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). Immature embryos in most genotypes showed high efficiency of callus induction except three genotypes; Eunpamil, Chunggemil, and Namhaemil, and significant differences among the genotypes. Plant regeneration of calli induced from immature embryos showed high efficiency in Geurumil (56.5%), Tapdongmil (50.5%), Gobunmil (45.5%), and Urimil(42.2%). The analysis of variance showed significant differences for regeneration frequency among the genotypes. Mature embryos showed low callus induction frequency compared with that in immature embryos, and significant differences among the genotypes. Plant regeneration of calli induced from mature embryos showed high efficiency in Keumkangmil (33.33%), Tapdongmil(28.13%), and Geurumil (27.78%). The analysis of variance showed significant differences for plant regeneration frequency among the genotypes.

• Journal of Electrochemical Science and Technology
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• v.8 no.2
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• pp.107-114
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• 2017

Pseudo capacitors belong to one group of super capacitors which are consisted with non carbon based electrodes. As such, conducting polymers and metal oxide materials have been employed for pseudo capacitors. Conducting polymer based pseudo capacitors have received a great attention due to their interesting features such as flexibility, low cost and ease of synthesis. Much work has been done using liquid electrolytes for those pseudo capacitors but has undergone various drawbacks. It has now been realized the use of solid polymer electrolytes as an alternative. Among them gel polymer electrolytes (GPEs) are in a key place due to their high ambient temperature conductivities as well as suitable mechanical properties. In this study, composition of a polyacrylonitrile (PAN) based GPE was optimized and it was employed as the electrolyte in a pseudo capacitor having polypyrrole (PPy) electrodes. GPE was prepared using ethylene carbonate (EC), propylene carbonate (PC), sodium thiocyanate (NaSCN) and PAN as starting materials. The maximum room temperature conductivity of the GPE was $1.92{\times}10^{-3}Scm^{-1}$ for the composition 202.5 PAN : 500 EC : 500 PC : 35 NaSCN (by weight). Performance of the pseudo capacitor was investigated using Cyclic Voltammetry technique, Electrochemical Impedance Spectroscopy (EIS) technique and Continuous Charge Discharge (GCD) test. The single electrode specific capacity (Cs) was found out to be 174.31 F/g using Cyclic Voltammetry technique at the scan rate of 10 mV/s and within the potential window -1.2 V to 1.2 V. The same value obtained using EIS was about 84 F/g. The discharge capacity ($C_d$) was 69.8 F/g. The capacity fade over 1000 cycles was rather a low value of 4%. The results proved the suitability of the pseudo capacitor for improving the performance further.

• Clean Technology
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• v.2 no.2
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• pp.100-125
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• 1996

After recycle of spent materials has been optimised, there remains a proportion of waste which must be dealt with in the most environmentally friendly manner available. For materials such as municipal waste, clinical waste, toxic waste and special wastes such as tyres, incineration is often the most appropriate technology. The study of incineration must take a process system approach covering the following aspects: ${\bullet}$ Collection and blending of waste, ${\bullet}$ The two stage combustion process, ${\bullet}$ Quenching, scrubbing and polishing of the flue gases, ${\bullet}$ Dispersion of the flue gases and disposal of any solid or liquid effluent. The design of furnaces for the burning of a bed of material is being hampered by lack of an accurate mathematical model of the process and some semi-empirical correlations have to be used at present. The prediction of the incinerator gas phase flow is in a more advanced stage of development using computational fluid dynamics (CFD) analysis, although further validation data is still required. Unfortunately, it is not possible to scale down many aspects of waste incineration and tests on full scale incinerators are essencial. Thanks to a close relationship between SUWIC and Sheffield Heat&Power Ltd., an extended research programme has been carried out ar the Bernard Road Incinerator plant in Sheffield. This plant consists of two Municipal(35 MW) and two Clinical (5MW) Waste Incinerators which provide district heating for a large part of city. The heat is distributed as hot water to commercial, domestic ( >5000 dwelling) and industrial buildings through 30km of 14" pipes plus a smaller pipe distribution system. To improve the economics, a 6 MW generator is now being added to the system.

• Korean Journal of Medicinal Crop Science
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• v.23 no.2
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• pp.125-131
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• 2015

In this study, we determined the ingredient analysis of harvested garlic bulb and soil analysis of four garlic-cultivated regions in Jeju, being one of the major areas of Namdo garlic production. Soil pH and electric conductivity were 7.02 and 1.03 dS/m, respectively. Soil organic matter was 4.31%. The mineral elements (potassium, calcium, magnesium, sodium, iron, manganese, copper and zinc) of Namdo garlic cultivated soil were analyzed by ICP, and calcium was the most highly contained mineral with $14.67cmol_+/kg$ and in the decreasing order of magnesium ($2.25cmol_+/kg$), potassium ($1.51cmol_+/kg$). Soluble solid and total acidity were 7.60 oBrix and 0.49%, respectively. The mineral contents of garlic bulb were in order of potassium (12,728 ppm) > sulfur (7,778 ppm) > phosphorus (4,916 ppm) > magnesium (691 ppm) > calcium (359 ppm). The content of total phenolic, total flavonoid and reducing sugar were 71.14 mg GAE/100 g, 17.64 mg QE/100 g and 26.53 mg GE/g, respectively. Alliin and allicin were 8.78 mg/g and 2.10 mg/g, respectively. The Pearson's correlation coefficients between mineral contents of soil and garlic bulb are analyzed. Macronutrients of soil is correlated with macronutrients of garlic (positive) and micronutrients of garlic (negative) contents.