• 한국응용과학기술학회지
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• 제35권1호
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• pp.151-156
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• 2018

산업과 의학이 발전되면서 많은 인구는 삶의 질에 관심을 가지게 되었다. 건강에 대한 시각이 높아지면서 육류보다 채식 또는 식물성 오일을 선호하게 되었다. 오늘날 주로 니켈 촉매를 사용한 공정이 개발되면서 식물성 오일의 보존기간이 늘어나고 이동성이 편리해졌다. 현재 유지경화용 니켈 촉매는 외국기업이 세계시장을 장악하고 있다. 한편, 국내 니켈 촉매의 대량 생산 기술은 퇴보 되어 전량 외국에서 수입하고 있는 실정이다. 따라서 활발한 기초연구가 필요하고 국내에서 상용화 할 수 있는 촉매개발이 필요하다. 본 연구는 수소화 반응으로부터 유지경화에 기반이 되는 니켈을 주 활성 촉매제로 사용하였고, 희토류가 촉매의 활성에 주는 영향을 알아보았다. 일정량의 희토류는 니켈의 분산을 유도하여 효율을 증가시키고 조촉매로써 사용이 가능하였다.

• Journal of Nutrition and Health
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• 제36권8호
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• pp.819-827
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• 2003

Linoleic acid [LA; 18: 2 (n-6)] is the most abundant polyunsaturated fatty acid in human skin. The exclusion of LA from diet induces epidermal hyperproliferation, which is reversible by the inclusion of LA in diet, and hence, LA is heralded as an essential fatty acid (EFA). Since safflower oil (SO) has been widely recognized as the major dietary source of LA and Arctii Fructus (Arctium lappa L.) is recently reported to contain high level of LA, we compared the antiproliferative effects of SO and Arctii Fructus in this study. Epidermal hyperproliferation was induced in guinea pigs by hydrogenated coconut oil (HCO) diet for 8 wk. During following 2 wk, EFA deficient guinea pigs were fed diets of safflower oil (group HS), water extract of Arctii Fructus (group AW) or organic extract of Arctii Fructus (group AO). Normal control group was fed SO containing diet (group SO) and EFA deficient group was fed HCO containing diet (group HCO) for 10 wk. Epidermal hyperproliferation was reversed in groups AO (55.9% of group HCO) and HS(74.1% of group HCO). However, the thymidine incorporation into epidermal DNA of group HS was greater than of normal control group SO. Epidermal hyperproliferation was not reversed in group AW. The accumulations of LA into phospholipids and ceramides, and of 13-hydroxyoctadecadienoic acid (13-HODE), the potent antiproliferative metabolite of LA in the epidermis of group AO were greater than of group HS. In contrast, the de novo synthesis of ceramides, the major lipids maintaining epidermal barrier, did not differ between all of groups. Together, our data demonstrate that organic extract of Arctii Fructus is more prominent than safflower oil in reversing epidermal hyperproliferation by inducing the higher accumulations of LA and 13-HODE in the epidermis of guinea pigs.

• Journal of Information Display
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• 제9권4호
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• pp.21-29
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• 2008

We studied both the wavelength and intensity dependent photo-responses (photofield-effect) in amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs). During the a-IGZO TFT illumination with the wavelength range from $460\sim660$ nm (visible range), the off-state drain current $(I_{DS_off})$ only slightly increased while a large increase was observed for the wavelength below 400 nm. The observed results are consistent with the optical gap of $\sim$3.05eV extracted from the absorption measurement. The a-IGZO TFT properties under monochromatic illumination ($\lambda$=420nm) with different intensity was also investigated and $I_{DS_off}$ was found to increase with the light intensity. Throughout the study, the field-effect mobility $(\mu_{eff})$ is almost unchanged. But due to photo-generated charge trapping, a negative threshold voltage $(V_{th})$ shift is observed. The mathematical analysis of the photofield-effect suggests that a highly efficient UV photocurrent conversion process in TFT off-region takes place. Finally, a-IGZO mid-gap density-of-states (DOS) was extracted and is more than an order of magnitude lower than reported value for hydrogenated amorphous silicon (a-Si:H), which can explain a good switching properties observed for a-IGZO TFTs.

• 약학회지
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• 제52권1호
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• pp.20-26
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• 2008

2-Aminothiazole ring as a bioisoster of catechol in dopamine has provided with good oral availability and lipophilic property. Selenium was reported to have an improved antioxidant ability and to reduce the loss of dopamine. 2-Aminoindan, is a rigid form of dopamine, was evaluated as a dopamine agonist with low neurotoxocity. In order to develop a novel dopamine agonist, we tried to synthesize the selenazoloaminoindan derivative that is a hybrid structure of aminoindan and aminoselenazole instead of aminothiazole. 2-Indanone-2-oxime was reduced with $TiCl_4$ and $NaBH_4$ to form 2-aminoindan, which was reacted with propionyl chloride to give 2-N-n-propionylaminoindan (2). Compound 2 was reduced with $TiCl_4$ and $NaBH_4$ to afford 2-N-n-propylaminoindan (3) and it was nitrated and reduced to form 5-amino-2-N-n-propylaminoindan (5), which was reacted with KSeCN, $Br_2$, and glacial acetic acid to give 4,6-dibromo-5- amino-2-N-n-propylaminoindan (7) instead of selenazole ring formation. Otherwise, compound 2 was nitrated and hydrogenated to form 5-amino-2-N-n-propionylaminoindan (9), which was treated with KSeCN, $Br_2$, and glacial acetic acid to give 4,6-dibromo-5-amino-2-N-n-propionylaminoindan (10). Compound 9 was cyc1ized with KSeCN and glacial acetic acid in the absence of $Br_2$ to give 6-amino-2-N-(n-propionylamino)selenazolo[4,5-f]indan (11).

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.178-191
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• 2003

OMC is essentialiy necessary compound in sun goods as organic UV protecting products. But the skin-trouble problem is raising because of skin penetration of OMC. In this study, non-capsulated pure OMC was compared with Organic-Inorganic-Nano-hybrid OMC for skin penetration force and SPF degree. Organic- Inorganic Nano-Hybrid OMC is OMC trapped in the pore of the mesoporous silica synthesized by the sol-gel method after OMC is nanoemulsified in the system of the hydrogenated Lecithin/ Ethanol/caprylic/capric triglyceride/OMC/water. OMC- nano- emulsion was obtained by a microfluidizing process at 1000bar and then micelle size in the nanoemulsion solution is 100-200nm range. Mesoporous silica nano-hybrid OMC was prepared by the process; surfactant was added in dissolved OMC-Nanoemulsion, then the rod Micelle was formed. OMC-nanoemulsion was capsulated in this rod Micelle and then silica precursor was added in the OMC-nanoemulsion solution. Through the hydrolysis reaction of the silica precursor, mesoporous silica concluding OMC-Nanocapsulation was obtained. The nano-hybrid surface of this OMC-Nanoemulsion-Inorganic system was treated with polyalkyl-silane compound. OMC-Mesoporous silica Nano-hybrids coated with polyalkyl-silane compound show the higher sun protecting factor (SPF Analyzer: INDEX 10-15) than pure OMC and could reduce a skin penetration of OMC. The physico-chemical properties of these nano-hybrids measured on the SPF index, partical size, strcture, specific surface area, pore size, morphology, UV absorption, rate of the OMC dissolution using SPF Analyzer, Laser light scattering system, XRD, BET, SEM, chroma Meter, HPLC, Image analyzer, microfluidizer, UV/VIS. spectrometer.

• 한국재료학회지
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• 제9권4호
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• pp.404-408
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• 1999

Effects of heating time and radiation under high temperature on the properties of thermal, mechanical and shielding ability of modified (KNS-101), hydrogenated bisphenol-A(KNS-201) type epoxy resin and phenol-novolac(KNS-301) type epoxy resin based neutron shielding materials that are used for shipping casks for radioactive material have been investigated. At early stages, the offset temperatures of KNS-101, KNS-201 and KNS-301 increased with the heating time under high temperature, but it was rarely affected by the heating time in the later stages. In addition, the thermal conductivities of KNS-101 and KNS-201 decreased with heating time, but that of KNS-301 increased with the heating time. On the contrary, the thermal expansion coefficients of neutron shielding materials decreased with heating time. At the high temperature, the tensile strength and flexural strength of the shielding materials decreased with heating time. On the contrary, the thermal expansion coefficients of neutron shielding materials decreased with heating time. At the high temperature, the tensile strength and flexural strength of the shielding materials of KNS-101 and KNS-301 increased with heating time, but those of KNS-201 decreased with heating time. The shielding ability of neutron shielding materials slightly increased with the radiation dose, and shielding abilities of shielding materials of KNS-101 and KNS-201 were affected to a more extent than that of KNS-301 by radiation dose under high temperature.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2737-2742
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• 2011

Ring-opening metathesis polymerization (ROMP) of an ethyl-substituted tetracyclododecene (8-ethyltetracyclo[$4.4.0.1^{2,5}.1^{7,10}$] dodec-3-ene, Et-TCD) was carried out in the presence of a ternary catalyst system consisting of $WCl_6$, triisobutyl aluminium (iso$Bu_3Al$), and ethanol. The optimal molar ratio of Et-TCD/$WCl_3$/iso-$Bu_3Al$/ethanol was found as 500/1/3/2 at which the yield of ring-opened polymer was 100%. 1-Hexene was shown to be an effective molecular weight controlling agent for ROMP reaction of Et-TCD. The hydrogenation of the ring opened polymer (p-Et-TCD) was conducted successfully using Pd(5 wt %)/${\gamma}$-$Al_2O_3$ at $80^{\circ}C$ for 1 h. Chemical structures of p-Et-TCD and its hydrogenated product($H_2$-p-Et-TCD) were characterized using 2D NMR techniques ($^1H-^1H$ COSY and $^1H-^{13}C$ HSQC). The changes of physical properties such as thermal stability, glass transition temperature and light transmittance after the hydrogenation were also investigated using TGA, DSC, and UV.

• 한국가금학회지
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• 제26권3호
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• pp.203-211
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• 1999

This study was performed to develop brand egg. Forty-four week-old Isa Brown were randomly assigned to 8 treatments and the number of hens were 300 per each group. Experimental period was about 10 weeks. The 8 treatment were as follows : astarich 2%(A), astarich 5%(B), chitch chitosan 2%(C), omega-3 powder 2%(D), pyrogreen 1%(E), greenpia 0.2%(F), hydrogenated soy oil 3%(G) and commercial layer feed(H). Eggs were collected at day 0, 7, 14, 40 and 70 for egg quality analyses. Laying rate was significantly higher in astarich groups(B, C) than ant other group, showing average of 88% of laying rate. In terms of egg factors, whole egg weight was the heaviest in control in control(A) and the lightest in omega-3 powder group(E), while egg yolk weight was the heaviest in astarich group(H). Haugh unit(HU) was the mean of 70 for all treatments and there were no significant differences among the treatments. Egg yolk color was significantly different among treatments during experimental period whenever yolk color was measured. At the day 7 after feeding of experimental diets, the yolk color of astarich 5% group(C) was darker and that of omega-3 powder group(E) lighter. The value of yolk color in astarich 5%(C) and 2%(B) was 14.2 and 12.5, respectively. But the rest of the groups did not show any differences in yolk color, showing mean of 11.5. In terms of shell thickness, shell tended to become thinner, but there were no defferences among treatments during experimental period. The mean value of shell thickness was 0.390mm. In conclusion, astarich groups may seem to produce the best possible quality of brand egg.

• 한국재료학회지
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• 제26권1호
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• pp.47-53
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• 2016

Silicon nitride ($SiN_x:H$) films made by plasma enhanced chemical vapor deposition (PECVD) are generally used as antireflection layers and passivation layers on solar cells. In this study, we investigated the properties of silicon nitride ($SiN_x:H$) films made by PECVD. The passivation properties of $SiN_x:H$ are focused on by making the antireflection properties identical. To make equivalent optical properties of silicon nitride films, the refractive index and thickness of the films are fixed at 2.0 and 90 nm, respectively. This limit makes it easier to evaluate silicon nitride film as a passivation layer in realistic application situations. Next, the effects of the mixture ratio of the process gases with silane ($SiH_4$) and ammonia ($NH_3$) on the passivation qualities of silicon nitride film are evaluated. The absorption coefficient of each film was evaluated by spectrometric ellipsometry, the minority carrier lifetimes were evaluated by quasi-steady-state photo-conductance (QSSPC) measurement. The optical properties were obtained using a UV-visible spectrophotometer. The interface properties were determined by capacitance-voltage (C-V) measurement and the film components were identified by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectroscopy detection (RBS) - elastic recoil detection (ERD). In hydrogen passivation, gas ratios of 1:1 and 1:3 show the best surface passivation property among the samples.

• Korean Chemical Engineering Research
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• 제54권4호
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• pp.519-526
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• 2016

Biomass derived jet fuel is proven as a potential alternative for the currently used fossil oriented energy. The efficient production of jet fuel precursor with special molecular structure is prerequisite in producing biomass derived jet fuel. We synthesized a new jet fuel precursor containing branched $C_{15}$ framework by aldol condensation of furfural (FA) and ethyl levulinate (EL), where the latter of two could be easily produced from lignocellulose by acid catalyzed processes. The highest yield of 56% for target jet fuel precursor could be obtained at the optimal reaction condition (molar ratio of FA/EL of 2, 323 K, 50 min) by using KOH as catalyst. The chemical structure of $C_{15}$ precursor was specified as (3E, 5E)-6-(furan-2-yl)-3-(furan-2-ylmethylene)-4-oxohex-5-enoic acid ($F_2E$). For stabilization, this yellowish solid precursor was hydrogenated at low temperature to obtain C=C bonds saturated product, and the chemical structure was proposed as 4-oxo-6-(tetrahydrofuran-2-yl)-3-(tetrahydrofuran-2-yl)-methyl hexanoic acid ($H-F_2E$). The successful synthesis of the new jet fuel precursors showed the significance that branched jet fuel could be potentially produced from biomass derived FA and EL via fewer steps.