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2-Thienyl chalcone 유도체에 대한 Thioglycolic acid의 친핵성 첨가반응 연구
공승대,황성규,이기창,최상회,오세영 明知大學校 産業技術硏究所 1994 産業技術硏究所論文集 Vol.13 No.-
The Addition reaction kinetics of 2-Thienyl chalone derivatives[][] was investigated by ultraviolet spectrophotometery in 20% dioxane-H2O at 25. The structure of these compounds were ascertained by means of ultraviolet, melting point,IR and NMR spectra. The final product was 2-thienyl chalcone-thioglycolic acid synthesized by the addition of thioglycolic acid for the 2-thienyl chalcone. The rate equations which were applied over a wide pH range(pH 1.013.0) were obtained. The substituent effects on 2-thienyl chalcone derivatives[][] were studied, and the addition reaction were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and general base effect,the plausible addition reaction mechanism was proposed : Below pH 9.0, neutral H2O molecule and thioglycolic acid anion competitively attacked on the double bond. Above pH 9.0, It was proportional to concentration of hydroxideion.
2-Fluorenyl chalcone 유도체의 합성과 가수분해반응에 관한 연구
이기창,황성규,윤철훈,오세영 명지대학교 자연과학연구소 1995 자연과학논문집 Vol.12 No.-
Fluorenyl chalcone 유도체를 합성하였고 25 ±1℃의 20% dioxane-H?O 혼합용매 중에서 자외선 분광광도법을 이용하여 pH 1.0~13.0까지의 넓은 pH범위에서 가수분해 반응속도를 측정하였다. 또한 Fluoreny chalcone 유도체의 pH변화에 따른 반응속도로 측정하고, 일반염기효과, 치환기효과 및 가수 분해 생성물 확인 등으로부터 Fluorenyl chalcone 유도체에 대한 가수분해 반응속도상수를 구하였다. 이들 유도체들은 pH와 무관한 부분과 수산화 이온농도에 비례하며, pH와 무관한 부분에서는 중성의 물분자가 첨가된다. 반응속도 상수 측정으로부터 Fluorency chalcon 유도체의 가수분해 반응은 비가역 1차 반응임을 확인하였고, 치환기효과로부터 전자유인성기에 의해 반응이 촉진되는 것을 알 수 있었다. 또한, 가수분해 최종 생성물은 확인 결과 2 ~acetyl fluorene과 벤즈알데히드였다. 이러한 실험결과를 토대로 하여 Fluorenyl chalcone 유도체에 대한 가수분해 반응 메카니즘을 제안하였다. Fluorenyl chalcone derivatives were synthesis, it was measured that hydrolysis made use of ultraviolet spectrophotometry at a wide pH 1.0 ~ 13.0 range in 20% dioxane-H?O solution, 25±1℃. On the basis of general base catalysis, substitutent effect and confirmation of hydrolysis product, it was measured the reaction rate of fluorenyl chalcone derivatives for the pH change. It maybe concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion: Above pH 10.0, It was in propotion to concentration of hydroxide ion, a part having no concern with pH was added to the neutral H?O molecule. From the result of measurement the reaction rate, hydrolysis of fluorenyl chalcone derivatives confirmed to the irreversible first order through measurement the substituent effect, It was found that reaction rate was accelerated first order through measurement the substituent effect, It was found that reaction rate was accelerated by electron attracting group. Also, from the result of final product, there were 2-acetyl fluorene benzaldehyde.On the basis of these findings, Hydrolysis for the fluorenyl chalcone derivative was proposed a fitting mechanism.
황용현,황성규,이한섭 한국유화학회 1998 한국응용과학기술학회지 Vol.15 No.4
In spite of various applications of chitin derivatives from waste marine sources, commercial use of chitin has been limited due to resistance to chemicals and the absense of proper solvents. We prepared chitin through decalcification, bleaching and deproteination from protunus triuberculatus shells by the application of Hackman's method. Structural and chemical properties of chitin were investigated to have proper specific surface area and particle size by IR, BET and PSA. The amount of absorbed water of chitin reached equilibrium by stirring about 15 minutes. The amount of absored water of the prepared chitin were large than the commercial chitin. When prepared chitin tested on dyeing wastewater, they showed better treatment efficiency in COD, suspended solid, and color tests than the commercial chitin. The adsorption capacity increased with decreasing particle size for the prepared chitin. Treatment efficiency for color was increased as the sitirring rate increased. Results show the possibility of the prepared chitin from waste marine sources as a treatment system for dyeing wastewater.
천연 Gum 류를 이용한 생분해성 필름의 제조와 생체분해
황성규,김판기,황성희 한국유화학회 1998 한국응용과학기술학회지 Vol.15 No.4
Gum is known as natural polymer. Biodegradable films were prepared by solution blend method in the weight ratio of natural gums(Xanthan, Locust bean, Guar) for the purpose of useful bioimplants. The possibility of bioimplants, which prepared from natural gums as a skin substitute was evaluated by measuring biodegradability. This biodegradable films were inserted in the back of rats and their of biodegradability were investigated by hematological change evaluation as a function of time to the biotransformation. Rats implantation test results showed that Guar induced increments of monocyte and basophil after 48 hours of implantation. And Locust bean showed increase of monocyte and neutrophile counts after 48 hours of implantation. And Xanthan induced decrease of monocyte and neutrophile at 24 hours after implantation. Guar and Locust showed high hemoglobin contents and hematocrit after 48 hours of implantation. Guar and Locust induced some suspects of incompatibility in the tissue after 48 hours, but three were little effects to yhe skin inflammation at 24 hours. These values of biodegradable films, which prepared from prepared from natural gums measured in this were some satisfiable results at short period with those of ideal skin bioimplants.
Park, Kwi‐,Il,Lee, Minbaek,Liu, Ying,Moon, San,Hwang, Geon‐,Tae,Zhu, Guang,Kim, Ji Eun,Kim, Sang Ouk,Kim, Do Kyung,Wang, Zhong Lin,Lee, Keon Jae WILEY‐VCH Verlag 2012 Advanced Materials Vol.24 No.22
<P>K. J. Lee and co‐workers demonstrate the fabrication of a flexible nanocomposite generator using piezoelectric BaTiO<SUB>3</SUB> nanoparticles and universal graphitic carbons (carbon nanotubes and reduced graphene oxide). The nanomaterials are dispersed in a matrix of polydimethyl‐siloxane and spun onto a metal‐coated plastic substrate. This method enables the production of self‐powered energy‐harvesting systems in a simple, low‐cost, and large‐scale manner, thus overcoming the limitations of previous nanogenerators. The resulting device is demonstrated on page 2999. </P>
Inverse size-dependence of piezoelectricity in single BaTiO<sub>3</sub> nanoparticles
Kim, Sung-Dae,Hwang, Geon-Tae,Song, Kyung,Jeong, Chang Kyu,Park, Kwi-Il,Jang, Jinhyuk,Kim, Kwang-Ho,Ryu, Jungho,Choi, Si-Young Elsevier 2019 Nano energy Vol.58 No.-
<P><B>Abstract</B></P> <P>The piezoelectric charge coefficients <I>d</I> <SUB>33</SUB> of single BaTiO<SUB>3</SUB> (BT) nanoparticles (NPs) were characterized using a transmission electron microscope (TEM) that is equipped with a precise charge meter and an in-situ TEM indentation holder that enables controlled compression experiments. An exceptionally high <I>d</I> <SUB>33</SUB> of 1775 pC/N was obtained in NPs that are smaller than the critical diameter (<I>D</I>; typically known as < 100 nm) that has been regarded as the lower limit to permit for ferroelectricity in BT. The mechanical conversion efficiency of piezoelectric BT nanogenerators enhanced as <I>D</I> of BT NPs was decreased; this result corresponds with the single-NP compression measurements of <I>d</I> <SUB> <I>33</I> </SUB>. This quantification of the effect of <I>D</I> in ferroelectric materials may guide development of efficient and high-powered nanostructured piezoelectric energy devices such as piezoelectric nanogenerators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The piezoelectric d33 of BT nanoparticles are characterized in a transmission electron microscope (TEM) with an in-situ stage. </LI> <LI> Exceptionally high d33 of 1775 pC/N by direct piezoelectric effect from a 50 nm BT nanoparticle is monitored. </LI> <LI> The piezoelectric nanogenrators with BT nanoparticles are fabricated to confirm the scaling effect of BT nanoparticles. </LI> <LI> The nanogenerator including BT nanoparticles shows an outstanding output performance compare to ordinal BT particles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
다차원 스펙트럼 해석법을 이용한 로드노이즈의 전달경로 해석 및 실내음압 예측
박상길(Sang-Gil Park),강귀현(Kwi-Hyun Kang),황성욱(Sung-Uk Hwang),오기석(Ki-Seok Oh),노국희(Kuk-Hee Rho),오재응(Jae-Eung Oh) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
This paper presents a the method for estimating the noise source contribution on the road noise of the vehicle in a multiple input system where the input sources may be coherent with each other. By coherence function method, it is found that the biggest part of the noise source in the road noise is generated by structural vibration on the mechanical-acoustic transfer functions of vehicles. This analysis is modeled as four input/single output system because the noise is generated with four wheels that mechanism of the road noise is very complicated. The coherence function method is proved to be useful tool for identifying of noise source. The overall levels of the interior noise be coherence function method are compared with those measured and calculated by the frequency response function approach using mechanical excitation test. The experimental results have shown a good agreement with the results calculated by the coherence function method when the input sources are coherent strongly each other. The estimation of the road noise indicates that significant coherent can be achieved in the vehicle interior noise.