• Elastomers and Composites
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• v.51 no.3
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• pp.240-249
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• 2016

$BiVO_4$ nanomaterial was synthesized from bismuth (III) nitrate pentahydrate [$Bi(NO_3)_3{\cdot}5H_2O$] and ammonium vanadate (V) [$NH_4VO_3$]. The $BiVO_4$-graphene nanocomposite was fabricated by calcining the $BiVO_4$ nanomaterial and graphene under an oxygen-free atmosphere at $700^{\circ}C$. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize structural and morphological properties of samples. The catalytic activity of the $BiVO_4$-graphene nanocomposite was studied for the reduction of 4-nitrophenol, 3-nitrophenol and 2-nitrophenol by sodium borohydride [$NaBH_4$]. The photocatalytic activity of the $BiVO_4$-graphene nanocomposite was demonstrated by the degradation of organic dyes like BG, MB, MO and RhB under irradiation at 365 nm. The catalytic and photocatalytic activity were studied by UV-vis spectrophotometry.

• Development and Reproduction
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• v.20 no.4
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• pp.367-377
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• 2016

Red spotted grouper, Epinephelus akaara, is a popular aquaculture species and a protogynous hermaphrodite. Induction of artificial sex change at the time of primary sex differentiation is of interest but has not been successful due to the lack of necessary basic information. To find out the potential neuroendocrine influence on the primary sex differentiation, the expression of key genes in the brain was investigated during the formation of ovarian cavity. Expression of cyp19a1b, esr1, gnrhr1, fsh, lh and cga in the brain was positively associated with the formation of ovarian cavity, showing gradual increase as the formation proceeds. However, the expression of gnrh1 was suppressed during the early part of the ovarian cavity formation, signifying potential hypothalamic influence on the primary sex differentiation in this species.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.1-8
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• 2009

This study was conducted to determine the effects of processed tobacco leaves on the development, adult emergence and body weight of the cigarette beetle, Lasioderma serricorne Fabricius) (Coleoptera: Anobiidae) is serious insect pest of tobacco leaves and cigarette during storage. Developmental time, adult emergence rate and adult weight of the cigarette beetle, were evaluated on the cured tobacco and burley tobacco leaves at $30{\pm}1^{\circ}C$ with $70{\pm}5$ % RH under 12L:12D. The developmental time on all of the flue-cured tobacco leaves was about 61 days, but in the only CD3W and CD4TR grade burley tobacco, the developmental times ranged from 70 days to 74 days. Among the flue-cured tobacco leaves, the highest beetle emergence rate was 123 % on the CD3L grade, and the lowest was on the AB4OR grade. Adult body weights of the cigarette beetle reared on flue-cured tobacco were about 2.11~2.46 mg, and on the only CD3W and CD4TR grade burley tobacco were about 1.86~1.96 mg. Among the flue-cured tobacco leaves, the highest adult body weight(2.46 mg) of cigarette beetle was observed on the B1O grade flue-cured tobacco, whereas the lowest adult weight(2.11 mg) was observed on the CD4L grade flue-cured tobacco. The adult weight of cigarette beetle reared on whole meal was 2.04mg.

• Korean Journal of Materials Research
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• v.20 no.2
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• pp.82-89
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• 2010

Benzotriazole (B.T.A) which has been mainly used for the stabilization processing method of excavated copper and bronze artifacts is vaporized within 2~3 years after the usage because it is unstable at the acid conditions and cannot protect the surface of artifacts. In this study, NaOH method which has been used for the steel artifacts was applied as a stabilization process for the method of copper and bronze artifacts to gush chlorine ion out. For the reproduction of excavated samples, copper and bronze plates were dipped in 0.1M HCl for 26 hrs to form CuCl, rusted at $70^{\circ}C$ with RH 75% for the formation of corrosion products, and desalted in 0.1 M NaOH solution. The concentration of chlorine ion was measured by using ionchromatography. During the desalting process, a large quantity of chlorine ions was gushed out in early period and corrosion products were not additionally generated through the re-corrosion experiment. This NaOH desalting process was found to be a method of stabilization process for copper and bronze artifacts from the formation of Tenorite (CuO) during desalting as a protection layer for corrosion.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.186.2-187
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• 2003

에틸렌 작용억제제인 1-MCP(1-methylcyclopropene) 처리에 따른 토마토의 선도연장효과를 검정하기 위해 본 연구는 수행되었다. 토마토“슈퍼도태랑(Supermomotaro)”품종을 Mature green 단계에서 수화한 다음 1-MCP를 2$0^{\circ}C$에서 250, 500, 및 1000ppb 의 농도로 4시간 동안 처리후 온도 2$0^{\circ}C$, 90% RH 조건에 저장하면서 에틸렌 발생, 호흡량 및 품질특성 변화를 조사하였다. 토마토의 에틸렌 발생은 모든 처리구에서 저장 2일째 급등하는 경향을 보였는데, 1-MCP 처리구는 무처리에 비해 그 급등정도가 낮았으며, 호흡량 또한 1-MCP 처리에 의해 효과적으로 억제되었다. 특히 처리 2일 후부터 무처리에 비해 2배정도 낮은 호흡량을 나타냈다. 과피의 착색진행 정도를 Hunter color의 적색도“a”값으로 비교한 결과, 무처리는 2일부터 6일까지 빠르게 증가하였지만 1-MCP 처리구는 그 증가 속도가 낮았으며, 처리농도가 높을수록“a”값의 변화가 적은 경향을 보였다. 또한 황색도“b”값의 비교에 있어서도 1-MCP 처리구가 무처리에 비해 그 변화가 적었다. 경도는 무처리에서 2일 후에 급격히 감소하는데 비해 1-MCP처리에서는 4일까지 그 감소 폭이 적었으며, 1-MCP처리 농도별 차이는 크지 않았다. 부패과 발생은 무처리와 500ppb 처리에서 비슷한 수준이었으며, 1000ppb 처리에서는 오히려 무처리에 비해 부패율이 높아 고농도 처리에 의한 장해로 판단되었다. 그러나 250ppb 처리는 무처리에 비해 부패율이 적게 나타났다.

• Journal of the Korean Ceramic Society
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• v.52 no.3
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• pp.173-179
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• 2015

We report the facile synthesis of graphene-$CdLa_2S_4$ composite through a facile solvothermal method at low temperature. The as-prepared products were characterized by X-ray diffraction (XRD) and by Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and BET analysis, revealing the uniform covering of the graphene nanosheet with $CdLa_2S_4$ nanocrystals. The as-prepared samples show a higher efficiency for the photocatalytic degradation of typical MB dye compared with P25 and $CdLa_2S_4$ bulk nanoparticles. The enhancement of visible-light-responsive photocatalytic properties by decolorization of Rh.B dye may be attributed to the following causes. Firstly, graphene nanosheet is capable of accepting, transporting and storing electrons, and thus retarding or hindering the recombination of the electrons with the holes remaining on the excited $CdLa_2S_4$ nanoparticles. Secondly, graphene nanosheet can increase the adsorption of pollutants. The final cause is that their extended light absorption range. This work not only offers a simple way to synthesize graphene-based composites via a one-step process at low temperature but also a path to obtain efficient functional materials for environmental purification and other applications.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1898-1899
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• 2005

반도체 집적회로 공정에서 사용되는 폴리이미드 포토레지스트(P12723, Dupont)를 감습막으로 사용하는 마이크로 습도센서 소자를 제작하였다. 마이크로 습도센서는 실리콘 웨이퍼 기판 위에 $SiO_2$ 박막을 건식열산화 공정으로 제작하고, Al 박막을 포토리소그라피 공정으로 패터닝 한 IDT (Interdigital Transducer)를 전극 위에 폴리이미드 포토레지스트를 공정변수를 다양하게 조절하면서 감습막으로 제작하였다. 폴리이미드 감습막은 스핀코팅법으로 제작하였으며, 회전수를 조절하여 두께를 변화시켰다. 완성된 마이크로 습도센서 소자의 상대습도 변화$(10{\sim}90% RH)$에 따른 정전용량 값 변화를 항온항습조 내에서 다양한 온도에서 HP4192A Impedance Analyzer를 사용하여 조사함으로써, 폴리이미드 포토레지스트를 사용하는 마이크로 정전용량형 습도센서의 제작 가능성을 검토하였다. 폴리이미드 정전용량형 마이크로 습도센서는 다양한 인가 전원 주파수에서 기준 센서로 사용된 상용 Vaisala Hygrometer와 유사한 감습특성 및 응답특성을 보였다.

• Journal of Life Science
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• v.5 no.1
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• pp.26-32
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• 1995

The antimutagenic effects of insoluble dietary fibers(IDF) extracted from some green-yellow vegetables(kale, carrot, spinach, broccoli and soybean sprout) and soybean by binding the carcinogens of MeIQ (2-amino-3,4- dimethyl-imidazo(4,5-f) quinoline) and Trp-P-2(3-amino-1-methyl-5H-pyrido[4,3-b] indole) in Salmonella tylhimirium TA100 and TA98 were studied. All of the insoluble dietary fiber samples which binded MeIQ exhibited high antimutagenic effects by removing the mutagen. Among the samples, IDFs from kale and soybean showed strong binding capacity fo the carcinogen and revealed about 90% of the antimutagenic activity. the IDF samples showed somewhat lower binding capacity to the Trp-p-2. The lignin which extracted from kale, soybean and carrot, and the cellulose strongly removed the mutagenicity of MeIQ by the binding. Among the samples, the level of lignin in kale revealed the highest(about 10%), and it seemed that the higher content of lignin in kale is one of the reasons to increase its antimutagenic effect.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3352-3358
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• 2023

Nuclear medicine seems to be a decent choice of medicine in the recent decade. The radioactive isotopes ⁵¹Cr, ⁸⁹Sr, ⁹⁹Tc, ¹³¹I, ¹³³Xe, ¹³⁷Cs and ¹⁵³Sm are extremely essential in nuclear medicine. The excitation functions of the ⁵⁴Fe (n, α) ⁵¹Cr, ⁹²Zr (n, α) ⁸⁹Sr, ¹⁰²Rh (n, α) ⁹⁹Tc, 134Cs (n, α) ¹³¹I, ¹³⁶Ba (n, α) ¹³³Xe, ¹⁴⁰La (n, α) ¹³⁷Cs and ¹⁵⁶Gd (n, α) ¹⁵³Sm reactions were calculated in this study using the EMPIRE 3.2.3 and TALYS 1.95 nuclear codes. Additionally, the cross sections at 14-15 MeV were calculated using empirical formulae and the experimental data. The computer codes were compared to the experimental data and Empirical formulas as well as the evaluated data (TENDL 2021, JENDL 3.3, JENDL 5, JEFF 3.3, EAF 2010, CENDL 3.1, CENDL 3.2, ROSFOND 2010, FENDL 3.2 b, and BROND 3.1).

• Elastomers and Composites
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• v.57 no.4
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• pp.181-187
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• 2022

CdSe-Mn nanocomposites were synthesized using a microwave method with sodium sulfite (Na₂SO₃), selenium (Se), cadmium sulfate octahydrate (3CdSO₄·8H₂O), ammonia solution (NH₃·H₂O), and manganese (II) sulfate monohydrate (MnSO₄·H₂O). We obtained CdSe-Mn-C₆₀ nanocomposites by calcining CdSe-Mn nanocomposites and fullerene (C₆₀) in an electric furnace at 700 ℃ for 2 h. X-ray diffraction, Raman spectroscopy, and scanning electron microscopy were used to characterize the crystal structures, lattice vibrations, and surface morphologies of the products, respectively. The photocatalytic activities of the CdSe-Mn-C₆₀ nanocomposites were investigated based on the photocatalytic degradations of organic dyes such as BG, MB, MO, and RhB under ultraviolet (UV) irradiation at 254 nm. UV-visible spectrophotometry was used to confirm the degradation process.