• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.50-50
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• 2002

The heterologous expression of sodN gene from Streptomyces seoulensis in Streptomyces lividans together with the gel filtration and sedimentation equilibrim data indicated that the quaternary structure of NiSOD is homohexamer, which is novel among SODs, not the previously reported homotetramer. The EPR spectrum of $^{61}$ Ni (I = 3/2) substituted NiSOD showed a clear resolved hyperfine structure at g=2.016, unambiguously identifying that the EPR signal from NiSOD is due to Ni.(omitted)

• Computers and Concrete
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• v.13 no.5
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• pp.621-632
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• 2014

This paper is aimed at adapting Artificial Neural Networks (ANN) to predict the compressive strength of High Performance Concrete (HPC) containing binary and quaternary blends. The investigations were done on 23 HPC mixes, and specimens were cast and tested after 7, 28 and 56 days curing. The obtained experimental datas of 7, 28 and 56 days are trained using ANN which consists of eight input parameters like cement, metakaolin, blast furnace slag and fly ash, fine aggregate, coarse aggregate, superplasticizer and water binder ratio. The corresponding output parameters are 7, 28 and 56 days compressive strengths. The predicted values obtained using ANN show a good correlation between the Experimental data. The performance of the 8-9-3-3 architecture was better than other architectures. It concluded that ANN tool is convenient and time saving for predicting compressive strength at different ages.

• Journal of the Korean Geophysical Society
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• v.5 no.1
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• pp.41-50
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• 2002

In order to delineate distribution of the basement in the vicinity of a Quaternary fault outcrop near the Gamsansa temple in Gyeongju, we conducted a seismic refraction survey along a 188 m profile with a 4 m receiver interval. Through tomographic inversion, we define four layers with refraction velocities of approximately 350 m/s, 600 m/s, 1,100 m/s and 2,400 m/s, respectively. We depict a reversed fault at a location of 40 m apart from the base station of the profile and interpret a fracture zone related to fault movements in the NNW of the profile.

• Bulletin of the Korean Mathematical Society
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• v.55 no.3
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• pp.971-997
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• 2018

The parity of cyclotomic numbers of order 2, 4 and 6 associated with 4-cyclotomic cosets modulo an odd prime p are obtained. Hence the explicit expressions of primitive idempotents of minimal cyclic codes of length $p^n$, $n{\geq}1$ over the quaternary field $F_4$ are obtained. These codes are observed to be subcodes of Q codes of length $p^n$. Some orthogonal properties of these subcodes are discussed. The minimal cyclic codes of length 17 and 43 are also discussed and it is observed that the minimal cyclic codes of length 17 are two weight codes. Further, it is shown that a Q code of prime length is always cyclotomic like a binary duadic code and it seems that there are infinitely many prime lengths for which cyclotomic Q codes of order 6 exist.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.104-105
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• 2006

We succeeded the synthesis of new functional polymers by novel ring-opening addition reactions of bis(oxetane)s with diacyl chlorides, di(active ester)s, and di(carboxylic acid)s using quaternary onium salts as catalysts at appropriate conditions. Hyperbranched polyesters with many pendant hydroxy groups were also synthesized by the polyaddition of bis(oxetane)s with tricarboxylic acid, or by the self-polyadditions of $AB_2\;or\;A_2B$ type monomers containing oxetane group. The anionic ring-opening polymerization of (3-ethyl-3-hydroxymethyl)oxetane was examined using sodium tert-buthoxide to give hyperbranched poly(ether)s containing one oxetanyl group and many hydroxyl groups in the end of polymer chain.

• Korean Journal of Pharmacognosy
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• v.17 no.1
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• pp.49-54
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• 1986

To explore the biological activities of Thalictrum alkaloids, a study was initiated to investigate the alkaloidal constituents from T. fauriei, a species indigenous to Taiwan. Extensive fractionation of the ethanolic extract provided three known aporphines, (+)-oconovine (Ia), (+)-isocorydine (Ib), and (+)-corydine (Ic) from nonphenolic tertiary base fraction. From quaternary base fraction two new protoberberinium salts, thalifaurine (IIa), dehydrodiscretine (IIb), in addition to magnoflorine (III), were isolated. The structure of both new compounds were confirmed by total syntheses. Fractionation of phenolic bases yielded a dihydromorphinandienone, (-)-ocobotrine (IV), as well as a novel aporphine-pavine dimer, tentatively named EP-10. The structure of EP-10 was established by means of 2D NMR studies. Preliminary study indicated a weak activity of lyzing Hela cells, in vitro, for EP-10.

• Carbon letters
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• v.16 no.1
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• pp.51-56
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• 2015

Carbonate-type organic electrolytes were prepared using propylene carbonate (PC) and dimethyl carbonate (DMC) as a solvent, quaternary ammonium salts, and by adding different contents of 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMImBF_4$). Cyclic voltammetry and linear sweep voltammetry were performed to analyze conducting behaviors. The surface characterizations were analyzed by scanning electron microscopy method and X-ray photoelectron spectroscopy. From the experimental results, increasing the $EMImBF_4$ content increased the ionic conductivity and reduced bulk resistance and interfacial resistance. In particular, after adding 15 vol% $EMImBF_4$ in 0.2 M $SBPBF_4$ PC/DMC electrolyte, the organic electrolyte showed superior capacitance and interfacial resistance. However, when $EMImBF_4$ content exceeded 15 vol%, the capacitance was saturated and the voltage range decreased.

• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.254-260
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• 2022

Trimethylammonium tetrafluoroborate (TriMA BF₄), consisting of the smallest trialkylammonium ion, was investigated for use in electrochemical double-layer capacitors. Despite the presence of a proton in TriMA⁺, cycle life tests in acetonitrile (AN) and -butyrolactone (GBL) showed a good capacity retention with a 1.8 V cut-off voltage. The rate of electrolysis of TriMA BF₄ in GBL was lower than that in AN because of the lower conductivity in GBL. As a consequence, the cells based on GBL achieved a higher capacitance and longer life than those with AN. TriMA BF₄ had a higher conductivity and lower viscosity than the quaternary salt tetraethylammonium tetrafluoroborate in GBL, as well as higher ionic mobility, these factors resulted in a higher rate capability.

• Textile Coloration and Finishing
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• v.13 no.6
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• pp.413-427
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• 2001

In this studs, we synthesized durable antistatic agents with acrylic monomers for preventing the electrification of static electricity which is one of defects of polyester fabrics. Also we synthesized quaternary ammonium salts which give antistatic property and crosslinking agents which make antistatic agents adhere to fiber. The treatment of synthesized antistatic agents on polyester fabric carried out at the condition of various concentrations, treatment times and temperatures. The antistatic property, handle characteristics and other properties of treated and untreated polyester fabrics were also investigated.

• Textile Coloration and Finishing
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• v.13 no.6
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• pp.55-55
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• 2001

In this study, we synthesized durable antistatic agents with acrylic monomers for preventing the electrification of static electricity which is one of defects of polyester fabrics. Also we synthesized quaternary ammonium salts which give antistatic property and crosslinking agents which make antistatic agents adhere to fiber. The treatment of synthesized antistatic agents on polyester fabric carried out at the condition of various concentrations, treatment times and temperatures. The antistatic property, handle characteristics and other properties of treated and untreated polyester fabrics were also investigated.