산화제를 이용한 아닐린폐수 처리

신진환,이원호 충주대 산업과학기술연구소 1996 産業科學論文集 Vol.4 No.-

This work carried out the removal of aniline by wet oxidation in aqueous solutions like a industrial wastewater using Ozone. UV, and Ozone - UV. The main features of this experiment are as follows : the aniline was decomposed by OH and HO2 radicals which produced from the reaction of water with UV and Ozone, when the Ozone and Ozone - UV used the aniline was decomposed completely. The decomposition of aniline was very fast reaction and the reaction times were 10 min. and 20 min. in case of for Ozone and Ozone-UV respectively. Assumed simplified reaction mechanism from the aniline oxidation model, and then we are calculated the theoretical reaction rate constants by computer simulation, and then compared with experimental data. We suggest that this simulation program is applicable to estimate of the aniline decaying concentration and removal efficiency of aniline - contaminated wastewater.

견인용 동기전동기의 시동 및 운전특성 해석에 관한 연구

황정원,조용길,송호신,박한규,우정인 東亞大學校 1994 東亞論叢 Vol.31 No.1

It needs a large capacity of equipments to test the starting performance of middle and large synchronous motors in a factory. This paper propose a new method which is the combination of single phase AC applied test and usual routine test with a small synchronous test machine and testing equipments. We can obtain the results from these proposed tests as follows ; (1) The starting performance and stabilized operation at variable speed is predicted from this results. (2) The armature winding leakage reactance is resulted from the no-load saturation curve, the short-circuit charactristic curve and the armature-reaction magnetomotive force converted to the field current. (3) This test must be performed twice, one for short-circuiting the field winding, the other for joining a resistance between the field terminals, as a result the unknown constants in equivalent circuits are identified. (4) Inverter-fed three phase voltage with variable frequency is applied to armature terminals, as a result, We show the actual armature leakage reactance and reaction of the induced harmonic voltages from rotor.

영구자석 동기발전기의 정주파수 정전압 출력에 관한 연구

우정인,조용길,황정원,송호신 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

The permanent magnet machines have the advantages of high efficiency and power density, features very improtant for air-borne applications with their requiement of no external dc supply for rotor excitation, in addition, a very lower synchronous reactance thus making it a stiff source of power with a higher steady state and more transient capability than ist counterpart, the wound rotor type. In this paper, The permanent magnet synchronous machine is taken as a power source in the variable speed constant frequency power conversion scheme with converter-inverter system. All digital routines are excuted in the sampling time of 100 micro second by a DSP Board (TMS320c25) with A/D converters, which is detect the load current, capacitor current and DC link voltage at a sudden load change and to compute the predicted current. In one sampling interval, two optimal space voltage vectors as well as tow zero voltage vectors are employed so that the capacitor current may follow the reference. As a result, sinusoidal output constant voltage is obtained while swiching frequency is constant, and experimental results are presented, which shows the effectiveness of the proposed control method.

Quantitative Determination of Absorption and First-Pass Metabolism of Apicidin, a Potent Histone Deacetylase Inhibitor

Shin, Beom Soo,Yoo, Sun Dong,Kim, Tae Hwan,Bulitta, Jurgen B.,Landersdorfer, Cornelia B.,Shin, Jeong Cheol,Choi, Jin Ho,Weon, Kwon-Yeon,Joo, Sang Hoon,Shin, Soyoung American Society for Pharmacology and Experimental 2014 Drug metabolism and disposition: the biological fa Vol.42 No.6

<P>Apicidin, a potential oral chemotherapeutic agent, possesses potent anti-histone-deacetylase activity. After oral administration, the total bioavailability of apicidin is known to be low (14.2%–19.3%). In the present study, we evaluated the factors contributing to the low bioavailability of apicidin by means of quantitative determination of absorption fraction and first-pass metabolism after oral administration. Apicidin was given to rats by five different routes: into the femoral vein, duodenum, superior mesenteric artery, portal vein, and carotid artery. Especially, the fraction absorbed (<I>F</I><SUB>X</SUB>) and the fraction that is not metabolized in the gut wall (<I>F</I><SUB>G</SUB>) were separated by injection of apicidin via superior mesenteric artery, which enables bypassing the permeability barrier. The <I>F</I><SUB>X</SUB> was 45.9% ± 9.7%, the <I>F</I><SUB>G</SUB> was 70.9% ± 8.1% and the hepatic bioavailability (<I>F</I><SUB>H</SUB>) was 70.6% ± 12.3%, while the pulmonary first-pass metabolism was minimal (<I>F</I><SUB>L</SUB> = 102.8% ± 7.4%), indicating that intestinal absorption was the rate-determining step for oral absorption of apicidin. The low <I>F</I><SUB>X</SUB> was further examined in terms of passive diffusion and transporter-mediated efflux by in vitro immobilized artificial membrane (IAM) chromatographic assay and in situ single-pass perfusion method, respectively. Although the passive diffusion potential of apicidin was high (98.01%) by the IAM assay, the in situ permeability was significantly enhanced by the presence of the P-glycoprotein (P-gp) inhibitor elacrider. These data suggest that the low bioavailability of apicidin was mainly attributed to the P-gp efflux consistent with the limited <I>F</I><SUB>X</SUB> measured in vivo experiment.</P>

Charge polarization-dependent activity of catalyst nanoparticles on carbon nitride nanotubes for hydrogen generation

Shin, Weon Ho,Yang, Seong Ho,Choi, Yoon Jeong,Jung, Hyung Mo,Song, Cheol Ock,Kang, Jeung Ku Royal Society of Chemistry 2009 Journal of materials chemistry Vol.19 No.26

<P>We demonstrate that catalyst nanoparticles attached to carbon nitride nanotubes (CNNTs) show superior catalytic activity for hydrogen generation from aqueous solutions. The calculated natural bonding orbitals show quite different charge polarizations for different catalysts attached to CNNTs; Co and Ni atoms attached to CNNTs are more positively polarized than Pt when they interact with NaBH<SUB>4</SUB> and H<SUB>2</SUB>O. Our experiments prove that the increased positive charges for Co and Ni result in a greater ability to attract hydride anions, thus improving the hydrogen generation rate. For example, Co catalysts attached to CNNTs show the highest hydrogen generation rate, up to 10 kg hydrogen per hour per 1 kg catalyst, while Pt is about 3 times less effective. It should therefore be feasible to use cheap metals such as Co for generating hydrogen from aqueous solutions for automobile applications.</P> <P>Graphic Abstract</P><P>Catalyst nanoparticles supported on carbon nitride nanotubes (CNNTs) can be utilized as excellent catalysts to generate hydrogen from aqueous solution. Co–CNNTs have the highest hydrogen generation rate, almost 3 times that for Pt–CNNTs. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b902786f'> </P>

Electrochemically Controlled Nanopore and Crystal Structure Evolution in Zinc Oxide Nanorods

Shin, Weon Ho,Hwang, Tae Hoon,Huh, Yun Suk,Choi, Jang Wook The Electrochemical Society 2012 Journal of the Electrochemical Society Vol.159 No.12

Enhanced thermoelectric performance of reduced graphene oxide incorporated bismuth-antimony-telluride by lattice thermal conductivity reduction

Shin, Weon Ho,Ahn, Kyunghan,Jeong, Mahn,Yoon, Jeong Seop,Song, Jae Min,Lee, Soonil,Seo, Won Seon,Lim, Young Soo Elsevier 2017 Journal of alloys and compounds Vol.718 No.-

<P><B>Abstract</B></P> <P>We investigate the thermoelectric properties of reduced graphene oxide (RGO) incorporated Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> composites. A melt spinning process enables RGO to be uniformly distributed with Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> matrix and the incorporated RGO increases the carrier mobility of Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> matrix with the enhancement of the power factor by 20%. The grain sizes of the Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> materials decrease with the RGO amount, leading to the reduction in lattice thermal conductivity by enhancing grain boundary scattering. Owing to the above effects, the thermoelectric figure of merit (ZT) can be enhanced in the measured temperature range, where the optimum ZT value is reached to 1.16 at 393 K, ∼15% higher ZT value than pristine Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB>. Consequently, this RGO incorporation method could be widely used to improve thermoelectric performances in other conventional thermoelectric materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The single step synthesis of reduced graphene oxide/Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> composites is proposed. </LI> <LI> The enhanced thermoelectric properties are obtained by incorporating reduced graphene oxide in Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB>. </LI> <LI> The reduced graphene oxide prevents the matrix diffusion during the sintering process in order to reduce BST grain size. </LI> <LI> The reduced graphene oxide in Bi<SUB>0.36</SUB>Sb<SUB>1.64</SUB>Te<SUB>3</SUB> provides an increment of charge carrier mobility. </LI> </UL> </P>

Enhancing Thermoelectric Performances of Bismuth Antimony Telluride via Synergistic Combination of Multiscale Structuring and Band Alignment by FeTe₂ Incorporation

Shin, Weon Ho,Roh, Jong Wook,Ryu, Byungki,Chang, Hye Jung,Kim, Hyun Sik,Lee, Soonil,Seo, Won Seon,Ahn, Kyunghan American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.4

<P>It has beeri a-difficulty to form well-distributed nano-and mesosized inclusions in a, Bi2Te3-based matrix and thereby realizing no degradation of carrier mobility at interfaces between matrix and inclusions for high thermoelectric performances. Herein, we Successfully synthesize multistructured thermoelectric Bi0.4Sb1.6Te3 materials with Fe-rich nano precipitates and sub-micron FeTe2 inclusions by a conventional solid-state reaction followed by melt-spinning, and spark plasma sintering that could be a facile preparation method for scale-up production. This study presents a bismuth antimony telluride based thermoelectric material with a multiscale structure whose lattice thermal conductivity is drastically reduced with minimal degradation on its carrier mobility. This is possible because a carefully chosen FeTe2 incorporated in the matrix allows its interfacial valence band with the matrix to be aligned, leading to a significantly improved p-type thermoelectric power factor. Consequently, an impressively high thermoelectric figure of merit ZT of 1.52 is achieved at 396 K for p-type Bi0.4Sb1.6Te3-8 mol % FeTe2, which is a 43% enhancement in ZT compared to the pristine Bi0.4Sb1.6Te3. This work demonstrates riot billy the effectiveness of multiscale structuring, for lowering lattice thermal conductivities, but also the importance of interfacial band alignment between matrix and inclusions for maintaining high carrier mobilities when designing high-performance thermoelectric materials.</P>

Nitrogen-Doped Multiwall Carbon Nanotubes for Lithium Storage with Extremely High Capacity

Shin, Weon Ho,Jeong, Hyung Mo,Kim, Byung Gon,Kang, Jeung Ku,Choi, Jang Wook American Chemical Society 2012 Nano letters Vol.12 No.5

<P>The increasing demands on high performance energy storage systems have raised a new class of devices, so-called lithium ion capacitors (LICs). As its name says, LIC is an intermediate system between lithium ion batteries and supercapacitors, designed for taking advantages of both types of energy storage systems. Herein, as a quest to improve the Li storage capability compared to that of other existing carbon nanomaterials, we have developed extrinsically defective multiwall carbon nanotubes by nitrogen-doping. Nitrogen-doped carbon nanotubes contain wall defects through which lithium ions can diffuse so as to occupy a large portion of the interwall space as storage regions. Furthermore, when integrated with 3 nm nickel oxide nanoparticles for a further capacity boost, nitrogen doping enables unprecedented cell performance by engaging anomalous electrochemical phenomena such as nanoparticles division into even smaller ones, their agglomeration-free diffusion between nitrogen-doped sites as well as capacity rise with cycles. The final cells exhibit a capacity as high as 3500 mAh/g, a cycle life of greater than 10 000 times, and a discharge rate capability of 1.5 min while retaining a capacity of 350 mAh/g.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2012/nalefd.2012.12.issue-5/nl3000908/production/images/medium/nl-2012-000908_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl3000908'>ACS Electronic Supporting Info</A></P>

Bimetallic catalysts selectively grown <i>via</i> N-doped carbon nanotubes for hydrogen generation

Shin, Weon Ho,Jung, Hyung Mo,Choi, Yoon Jeong,Miyasaka, Keiichi,Kang, Jeung Ku Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.31

<P>This work provides both a facile method to synthesize bimetallic catalysts (BMCs) <I>via</I> pyridine-like N atoms of N-doped carbon nanotubes (NDCNTs) and also a picture about how to design the optimal BMC for hydrogen generation from the hydrogen storage material. In principle, the ratio of one component to another component could be generically extended to fabricate the high-performance BMCs on host nanostructures. Indeed, we demonstrate that the BMC composed of the optimum composition (Ni<SUB>0.72</SUB>Pt<SUB>0.28</SUB>) results in the large hydrogen generation of ∼28 kg h<SUP>−1</SUP>/kg of catalyst from an aqueous borane ammonia hydrogen storage, thus being capable of satisfying the DOE target (7.2 kg h<SUP>−1</SUP>) required for advanced applications even with the small amount of our BMC attached onto the NDCNTs. This high hydrogen generation rate is found to be attributed to the optimal distance between active Pt and cheap Ni atoms for effective hydrogen generation.</P> <P>Graphic Abstract</P><P>Ni–Pt bimetallic catalysts on N-doped carbon nanotubes show an excellent hydrogen generation rate of 27.6 kg h<SUP>−1</SUP>/kg of catalyst with a small activation energy. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm01126f'> </P>