• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.124-128
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• 1997

Semivolatile components in mainstream smoke of cigarette attached the different type filter were analysed. Based on the main peak of GC profile, benzene, toluene, acetic acid, limonene, acetamide, pyridine, nicotine, phenol, pyrrole, and furfuryl alcohol were identified. The amount delivered of semivolatile components by each filter was evaluated with the ratio of areas of sample vs area% of ISTD. By comparing dual and triple filter to mono filter, the delivery amounts were 52% benzene, 62% toluene and 74% benzene, 84% toluene, respectively. The delivery amount of limonene which was known of tobacco taste component, were 52%, and 93% by dual and triple filter, respectively. Also, delivery amounts of acetic acid which was one of acidic compounds in smoke, were 86% and 83% by dual and triple filter, respectively. When adding the same amount of active carbon, the amounts delivered of vapour phase such as benzene and toluene by dual filter were lower than that of triple filter. But the delivery amounts of acetic acid and phenol by dual filter were higher than that of triple filter. This results assume that the pH of active carbon in filter affect to the adsorption or absorption of triacetin during filter making process.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.817-821
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• 2016

Levodopa or L-3,4-dihydroxyphenylalanine (L-DOPA) is the direct precursor of the neurotransmitter dopamine. L-DOPA is a well-known neuroprotective agent for the treatment of Parkinson's disease symptoms. L-DOPA was synthesized using the enzyme, tyrosinase, as a biocatalyst for the conversion of L-tyrosine to L-DOPA and an electrochemical method for reducing L-DOPAquinone, the product resulting from enzymatic synthesis, to L-DOPA. In this study, three electrode systems were used: A glassy carbon electrode (GCE) as working electrode, a platinum, and a Ag/AgCl electrode as auxiliary and reference electrodes, respectively. GCE has been modified using electropolymerization of pyrrole to facilitate the electron transfer process and immobilize tyrosinase. Optimum conditions for the electropolymerization modified electrode were a temperature of $30^{\circ}C$ and a pH of 7 producing L-DOPA concentration 0.315 mM. After 40 days, the relative activity of an enzyme for electropolymerization remained 38.6%, respectively.

• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.135-148
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• 2012

Ionic liquids are steadily attracting interests throughout a recent decade and their application is expanding into various fields including electrochemistry due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, wide electrochemical potential window and so on. These features make ionic liquids become an alternative solution for electrodeposition of metals that cannot be electroplated in aqueous electrolytes. In this review, we classify investigated metals into three categories, which are light (Li, Mg), refractory (Ti, Ta) and noble (Pd, Pt, Au) metals, rather than covering the exhaustive list of metals and try to update the recent development in this area. In electrodeposition of light metals, granular fine Li particles were successfully obtained while the passivation of electrodeposited Mg layers is an obstacle to reversible deposition-dissolution process of Mg. In the case of refractory metals, the quality of Ta and Ti deposit particles was effectively improved with addition of LiF and pyrrole, respectively. In noble metal category, EMIM TFSA ionic liquid as an electrolyte for Au electrodeposition was proven to be effective and BMP TFSA ionic liquid developed a smooth Pd deposit. Pt nanoparticle production from ionic liquid droplet in aqueous solution can be cost-effective and display an excellent electrocatalytic activity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.615-620
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• 2002

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidise (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized enzyme electrodes by electropolymerization added some organic solvent, such as ethanol and tetrahydrofuran (THF). The formative seeds of film growth was delayed by adding ethanol. The delay was induced by radical transfer between ethanol and pyrrole monomer. The radical transfer reactions shared the contribution of dopants between electrolyte anion and GOx polyanion. This led to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.704-710
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• 2004

A poly(1-hexyl-3,4-dimethyl-2,5-pyrrolylene) (PHDP) was prepared and its luminescence in tetrahydrofuran (THF) was studied. When PHDP is excited by UV light, it produces very strong blue luminescence. The quantum yield of PHDP (Q = 36.9%) is much greater than that of the monomer, 1-hexyl-3,4-dimethylpyrrole (HDP) with Q = 0.61%. The principal luminescence of PHDP has a single decay component with ca. 1 ns, whereas the decay of HDP is complicated. The molecular structure and conformational behavior of HDP and the oligomers up to trimer have been also determined by ab initio Hartree-Fock (HF/6-31$G^{**}$), density functional theory (DFT-B3LYP/6-31$G^{**}$), and semiempirical (ZINDO) methods. According to the results of calculations, it is proposed that the enhanced quantum yield of the polymer PHDP results mostly from the ${\pi}$-conjugation between neighboring pyrrole rings.

• Korean Journal of Materials Research
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• v.13 no.12
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• pp.796-800
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• 2003

The polypyrrole prepared with pyrrole monomer, APS and DBSA was synthesized by chemical Polymerization at $V^{\circ}C$ under atmosphere conditions. After dissolving polypyrrole powder to the chloroform including DBSA, polypyrrole film was prepared on the alumina substrate with an interdigitated electrode by using the dip-coating method. This film was soaked in methanol solvent for 1 h at room temperature and heated to $70^{\circ}C$ for 4 h in $N_2$. Initial resistance was increased with the increasing humidity and decreasing temperature. The sensitivity was increased with lower humidity and decreasing temperature. The best linearity was achieved at $25^{\circ}C$ and low humidity of 0%.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.1
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• pp.1-10
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• 2017

Adsorption is a plausible technology using solid adsorbents for dry capture of carbon dioxide ($CO_2$). In general, narrow size distribution of tiny pores and surface chemical functionalities of solid adsorbents enhance the adsorption capacity of gaseous $CO_2$ molecules. In order to utilize the advantages of fibrous adsorbents, this work prepared activated carbon nanofibers (ACNFs) via the electrospinning process using a polymer precursor of polyacylonitrile (PAN). The spun fibers were 390 nm to 580 nm in thickness with an average surface area of $27.3m^2/g$. The surface structure was improved by a programmed thermal activation at $800^{\circ}C$ in $CO_2$ atmosphere. It was also found that the nitrogen-groups including pyrrole and pyridine were created during the activation facilitaing the selective adsorption as forming enhanced active sites. The finally obtained adsorption capacities were 2.74 mmol/g for pure $CO_2$ flow and 0.74mmol/g for 3000 ppm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.141-146
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• 2002

We synthesized polypyrrole (PPy) by electrolysis of the pyrrole monomer solution containing support electrolyte, KCl and/or p-toluene sulfonic acid sodium salt (p-TS). The electrochemical behavior, was investigated using cyclic voltammetry and AC impedance. In the case of using electrolyte p-TS, the oxidation potential of the PPy was about -02 V vs Ag/AgCl reference electrode, while the potential was about 0 V for using electrolyte KCl. The falloff of the oxidation potential gave a sign of an improvement in the electron hopoing mechanism on the backbone. The AC impedance plot gave a hint of betterment of mass transport. PPy doped with p-TS improved in mass transport or diffusion. That was because the PPy doped with p-TS was more porous than PPy with KCl. We attained an effect of good kinetic parameters, in the case of PP-GOx enzyme electrodes doped with p-TS, which were determined by 58 mmol dm$\^$-3/ for apparent Michaelis constant and by 581 ㎂ for maximum current respectively.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.617-621
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• 2014

An efficient and selective method for the synthesis of ethyl 2-amino/aryloxy-3-aryl-4-oxo-5-phenyl-4,5-dihydro-3H-pyrrolo[3,2-d]pyrimidine-7-carboxylate derivatives has been developed. The main process involved the reaction of diethyl 1-phenyl-3-((triphenylphosphoranylidene)amino)-1H-pyrrole-2,4-dicarboxylate and aromatic isocyanates, followed by addition of amines/phenols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1706-1719
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• 2020

The objective of this study was to optimize the conditions for enhancing the antioxidant properties of sword bean (Canavalia gladiata) as a coffee substitute in two processing methods, roasting and grinding. The optimum conditions for removing off-flavor of the bean and maximizing functionality and efficiency were light roasting and cryogenic grinding (< 53 ㎛). In these conditions, extraction yield was 16.75%, total phenolic content (TPC) was 69.82 ± 0.35 mg gallic acid equivalents/g, and total flavonoid content (TFC) was 168.81 ± 1.64 mg quercetin equivalents/100 g. The antioxidant properties were 77.58 ± 0.27% for DPPH radical scavenging activity and 58.02 ± 0.76 mg Trolox equivalents/g for ABTS radical scavenging activity. The values for TFC and ABTS radical scavenging activity were significantly higher (p < 0.05) than in other conditions, and TPC and DPPH radical scavenging activity were second highest in lightly roasted beans, following raw beans. HS-SPME/GC-MS analysis confirmed that the amino acids and carbohydrates, which are the main components of sword bean, were condensed into other volatile flavor compounds, such as derivatives of furan, pyrazine, and pyrrole during roasting. Roasted and cryogenically ground (cryo-ground) sword beans showed higher functionality in terms of TFC, DPPH, and ABTS radical scavenging activities compared to those of coffee. Overall results showed that light roasting and cryogenic grinding are the most suitable processing conditions for enhancing the bioactivity of sword beans.