• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.501-505
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• 2004

Esterification of aliphatic or aromatic carboxylic acids with alcohols using 2-(4-nitrobenzenesulfonyl)-4,5-dichloropyridazin-3(2H)-one (3) in the presence of base in organic solvents gave the corresponding esters in excellent yields

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2797-2800
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• 2010

For the purpose of developing advanced new absorbents for carbon dioxide, ionic liquids (ILs) are considered as alternative materials due to their superior properties to conventional organic solvents. Since low $CO_2$ solubility in ionic liquids is a major concern for their application as absorbents, it is essential to focus on improving $CO_2$ absorbing capability of ILs. In this paper, strongly basic ionic liquids, namely [$C_n$-mim]OPh (n = 2, 4, 6), have been synthesized and studied over a wide range of temperature and pressure changes. [$C_n$-mim]OPh can be easily synthesized from corresponding [$C_n$-mim]Cl and sodium phenoxide and has been found to be good $CO_2$ absorbents.

• 통합자연과학논문집
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• 제5권4호
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• pp.253-256
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• 2012

The rugate porous silicons containing multiple photonic band gaps have been generated by applying a composite waveform summed three computer-generated pseudo-sinusoidal current waveforms and exhibit three sharp photonic band gaps in the optical reflectivity spectrum. Generated multiple rugate porous silicons display three rugate peaks corresponding to the each of the sine components varied from 0.42, 0.36, and 0.30 Hz, with a spacing of 0.06 Hz between each sine component. The resulting rugate PSi films have been removed from the silicon substrate by applying an lift-off current and are then made into particles by ultrasono-method in a organic solution. The sensing experiments using these particles for organic solvents such as toluene, hexane, acetone, and methanol have been achieved. Condensing of organic vapors in the pores increases the refractive indices of entire particle which results a red shift in the photonic peaks.

• 한국발생생물학회지:발생과생식
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• 제22권4호
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• pp.379-391
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• 2018

Through the development of organic synthetic skill, chemicals that mimic signaling mediators such as steroid hormones have been exposed to the environment. Recently, it has become apparent that this circumstance should be further studied in the field of physiology. Estrogenic action of chronic low-dose nonylphenol (NP) and di-(2-ethylhexyl) phthalate (DEHP) in mouse uterus was assessed in this study. Ten to twelve-week-old female mice (CD-1) were fed drinking water containing NP (50 or $500{\mu}g/L$) or DEHP (133 or $1,330{\mu}g/L$) for 10 weeks. Uterine diameter, the thickness of myometrium and endometrium, and the height of luminal epithelial cells were measured and the number of glands were counted. The expression levels of the known $17{\beta}$-estradiol ($E_2$)-regulated genes were evaluated with real-time RT-PCR methodology. The ration of uterine weight to body weight increased in $133{\mu}g/L$ DEHP. Endometrial and myometrial thickness increased in 133 and $1,330{\mu}g/L$ DEHP treated groups, and in 50, $500{\mu}g/L$ NP and $133{\mu}g/L$ DEHP, respectively. The height of luminal epithelial cell decreased in NP groups. The numbers of luminal epithelial gland were decreased in NP groups but increased in $50{\mu}g/L$ DEHP group. The histological characters of glands were not different between groups. The mRNA expression profiles of the known $17{\beta}$-estradiol ($E_2$) downstream genes, Esr1, Esr2, Pgr, Lox, and Muc1, were also different between NP and DEHP groups. The expression levels dramatically increased in some genes by the NP or DEHP. Based on these results, it is suggested that the chronic low-dose NP or DEHP works as estrogen-like messengers in uterus with their own specific gene expression-regulation patterns.

• 환경위생공학
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• 제22권1호
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• pp.17-27
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• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3233-3240
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• 2012

We demonstrated the combined applications of online protein digestion using trypsin immobilized enzyme reactor (IMER) and dual tandem mass spectrometry with collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) for tryptic peptides eluted through the trypsin-IMER. For the trypsin-IMER, the organic and inorganic hybrid monolithic material was used. By employing the trypsin-IMER, the long digestion time could be saved with little or no sacrifice of the digestion efficiency, which was demonstrated for standard protein samples. For three model proteins (cytochrome c, carbonic anhydrase, and bovine serum albumin), the tryptic peptides digested by the IMER were analyzed using LC-MS/MS with the dual application of CAD and ETD. As previously shown by others, the dual application of CAD and ETD increased the sequence coverage in comparison with CAD application only. In particular, ETD was very useful for the analysis of highly-protontated peptide cations, e.g., ${\geq}3+$. The combination approach provided the advantages of both trypsin-IMER and CAD/ETD dual tandem mass spectrometry applications, which are rapid digestion (i.e., 10 min), good digestion efficiency, online coupling of trypsin-IMER and liquid chromatography, and high sequence coverage.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2396-2400
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• 2007

Transparent In-doped (1 at.%) zinc oxide (IZO) thin films are deposited by pulsed DC magnetron sputtering with H2 mixed Ar atmosphere on glass substrate without any heating process. Even at room temperature, highly c-axis oriented IZO thin films were grown in perpendicular to the substrate. The hydrogenated IZO (IZO:H) film isolated in H2 atmosphere for 30 min exhibited an average optical transmittance higher than 85% and low electrical resistivity of less than 2.7 × 10?3 Ω·cm. These values are comparable with those of commercially available ITO. Each of the IZO films was used as an anode contact to fabricate organic light-emitting diodes (OLEDs) and the device performances studied. At the current density of 1 × 103 A/m2, the OLEDs with IZO:H (H2) anode show excellent efficiency (11 V drive voltage) and a good brightness (8000 cd/m2) of the light emitted from the devices, which are as good as the control device built on a commercial ITO anode.

• Applied Science and Convergence Technology
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• 제23권1호
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• pp.44-47
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• 2014

In this study, we investigated the basic properties of N-doped ethylcyclohexene plasma polymer thin films that deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition (PECVD) method with controlled ammonia flow rate. Ethylcyclohexene was used as organic precursor with hydrogen gas as the precursor bubbler gas. Additionally, ammonia ($NH_3$) gas was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, UV-Visible spectroscopy, and water contact angle measurement. We found that with increasing plasma power, film thickness is gradually increased while optical transmittance is drastically decreased. However, under the same plasma condition, water contact angle is decreased with increasing $NH_3$ flow rate. The FT-IR spectra showed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

• Bulletin of the Korean Chemical Society
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• 제4권4호
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• pp.157-161
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• 1983

Ab initio calculations were performed on systems containing various basic ${\pi}$ fragments and glycines to generalize the ${\pi}$-nonbonded interaction (${\pi}$-NBI) method of determining relative conformational and configurational stability of organic molecules. It was found that the relative stability of conformational isomers can be determined in general by the simple application of the ${\pi}$-NBI method, but the method is not applicable to the geometrical isomerism in which stronger structural factors are involved. The ${\pi}$-NBI effect of a crowded ${\pi}$-structure ($n{\pi}/m$) is maximum for the system in which n is equal to m. In crowded structures containing heteroatoms, ${P^{\pi}}_{ij}$ values of 4N+1 system may become negative, but this sign reversal does not invalidate the predictions based on the ${\pi}$-NBI method.

• Advances in environmental research
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• 제2권4호
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• pp.291-308
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• 2013

In the present study, an experimental design methodology was used to optimize the adsorptive removal of Basic Yellow 13 (BY13) using Turkish coal powder. A central composite design (CCD) consisting of 31 experiments was employed to evaluate the simple and combined effects of the four independent variables, initial dye concentration (mg/L), adsorbent dosage (g/L), temperature ($^{\circ}C$) and contact time (min) on the color removal (CR) efficiency (%) and optimizing the process response. Analysis of variance (ANOVA) showed a high coefficient of determination value ($R^2=0.947$) and satisfactory prediction of the polynomial regression model was derived. Results indicated that the CR efficiency was not significantly affected by temperature in the range of $12-60^{\circ}C$. While all other variables significantly influenced response. The highest CR (95.14%), estimated by multivariate experimental design, was found at the optimal experimental conditions of initial dye concentration 30 mg/L, adsorbent dosage 1.5 g/L, temperature $25^{\circ}C$ and contact time 10 min.