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Rotor Position Detection Method of a Single Phase Switched Reluctance Motor Using Back EMF
Han-Geol Sun,Duck-Sick Shin,Hyong-Yeol Yang,Young-Cheol Lim 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-
This paper presents the position estimation and driving method of single phase Switched Reluctance Motor(SRM) using Back EMF. To drive SRM, the information about position of a rotor must be fully needed. Generally, a rotor's position sensor is used to detect the rotor position. However, most of position sensors are complex and increase the constructing cost of the system. Moreover, these sensors tend to decrease reliability of driving system. Therefore, a detecting method of a rotor's specific position using Back EMF is supposed to solve those problems mentioned above. When a rotor pole and a stator pole are overlapped, a variation occurs in the Back EMF waveform and the instant of the overlap can be detected. Therefore the rotor position and speed can be calculated and the SRM is driven by appropriate switching. The validity of presented method is verified through simulation and experiment.
Galvanic synthesis of three-dimensional and hollow metallic nanostructures
Park, Sun Hwa,Son, Jin Gyeong,Lee, Tae Geol,Kim, Jongwon,Han, Sang Yun,Park, Hyun Min,Song, Jae Yong Springer US 2014 NANOSCALE RESEARCH LETTERS Vol.9 No.1
<P>We report a low-cost, facile, and template-free electrochemical method of synthesizing three-dimensional (3D) hollow metallic nanostructures. The 3D nanoporous gold (3D-NPG) nanostructures were synthesized by a galvanic replacement reaction (GRR) using the different reduction potentials of silver and gold; hemispherical silver nanoislands were electrochemically deposited on cathodic substrates by a reverse-pulse potentiodynamic method without templates and then nanoporous gold layer replicated the shape of silver islands during the GRR process in an ultra-dilute electrolyte of gold(III) chloride trihydrate. Finally, the wet etching process of remaining silver resulted in the formation of 3D-NPG. During the GRR process, the application of bias voltage to the cathode decreased the porosity of 3D-NPG in the voltage range of 0.2 to -0.62 V. And the GRR process of silver nanoislands was also applicable to fabrication of the 3D hollow nanostructures of platinum and palladium. The 3D-NPG nanostructures were found to effectively enhance the SERS sensitivity of rhodamine 6G (R6G) molecules with a concentration up to 10<SUP>-8</SUP> M.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/1556-276X-9-679) contains supplementary material, which is available to authorized users.</P>
Synthesis and NIR Absorption Properties of Triethylene Glycol Substituted Metallo-Naphthalocyanines
Seong-Hun Han(한성훈),Gopal Balamurugan(고팔 발라무루간),Jae Woong Jang(장재웅),Fayong Sun(손법용),Nguyet N. T. Pham(팜티누구엣),Seung Geol Lee(이승걸),Jong S. Park(박종승) 한국고분자학회 2021 폴리머 Vol.45 No.6
다양한 전이 금속의 존재하에서 트리에틸렌 글리콜(TEG) 치환체를 가지는 함금속 나프탈로시아닌 유도체(MNPcs)을 합성하고, 이들의 광학적 및 근적외(NIR) 영역에서 흡수 특성을 조사하였다. UV-Vis 스펙트럼 측정 결과에 따르면 MNPcs는 나프탈로시아닌 구조 주변부에 부가된 페닐링과 비주변부(non-peripheral) 위치에 치환된 전자주게 치환체로 인해 NIR 영역에서 강한 흡수 특성을 나타내었다. 또한, MNPcs의 최대 흡수파장은 중앙부 금속의 종류에 따라 780에서 950 nm까지 광범위하게 조정할 수 있었다. 또한, 친수성이 강한 TEG 치환체가 존재함에 따라 극성 용매에서의 용해도와 고분자 매트릭스에 대한 상용성이 크게 증진하는 효과를 나타내었다. 높은 NIR 영역 흡수 및 가시광 투과도를 보이는 MNPc의 특성을 이용하여 근적외 차단 필름을 제조하였다. 니켈-나프탈로시아닌(nickel naphthalocyanine)을 포함하여 근적외 차단 필름을 제조하였을때 안티몬 주석 산화물(ATO) 단독 대비 가시광선 투과성은 그대로 유지하면서 근적외 차단 성능을 향상할 수 있는 것으로 확인되었다. 상기 결과로 보건데 근적외 차단 물질로서의 함금속 나프탈로시아닌의 효능을 확인할 수 있으며, 이는 근적외 흡수성과 극성 매체에 대해 상용성을 동시에 발휘하는 것에 기인하는 것이다. Naphthalonitrile substituted with triethylene glycol (TEG) in the presence of transition metals synthesized a series of metallo-naphthalocyanine derivatives (MNPcs), and it was investigated that the optical and near-infrared (NIR) absorption properties. In UV-Vis spectra measurements, these MNPcs exhibited strong absorption in the NIR regions because of the annulated benzene ring of naphthalocyanine and highly electron-donating substituents attached at the non-peripheral positions. The absorption wavelength of MNPcs was effectively adjusted in NIR ranges from 780 to 950 nm by inserting various central metals. Additionally, the presence of TEG-substituents in MNPcs significantly enhanced the solubility in highly polar solvents and the compatibility with the polymer matrix. NIR blocking films were fabricated for taking advantage of high NIR absorption and visible transmittance. When NIR film was fabricated with nickel-napthalocyanine, it was confirmed that the NIR cutting property can be improved while maintaining the visible light transmittance compared to the antimony tin oxide (ATO). From the observations, the feasibility of designed MNPcs as an effective NIR blocking material was evidenced, which is attributed to its strong NIR absorption and compatibility in the polar mediums.
이인걸(In Geol Yi),강진규(Jin Kyu Kang),김성배(Song Bae Kim),김현중(Hyun Jung Kim),한요셉(Yo Sep Han),엄익춘(Ig Chun Eom),조은혜(Eun Hye Jo),박선영(Sun Young Park) 大韓環境工學會 2014 대한환경공학회지 Vol.36 No.8
탄소나노물질은 대표적인 나노물질로써, 풀러렌, 탄소나노튜브, 그래핀 등을 포함한다. 탄소나노물질은 다양한 분야에서 널리 이용되고 있는데, 생산, 사용, 처리 등의 단계에서 환경에 노출될 수 있고, 일단 노출이 되면 다양한 계로 확산되어 여러 생태학적 수용체에 큰 위협이 될 수 있다. 탄소나노물질이 토양환경에 노출되었을 때, 물의 흐름을 따라 토양을 통과하여 지하수에 노출될 가능성 여부를 판단하기 위하여 연구들이 진행되고 있다. 토양이 탄소나노물질의 이동을 제한하는 역할을 잘하는 것으로 판단될 경우에는, 탄소나노물질의 지하수 노출 가능성이 상당히 낮아질 것이다. 본 논문에서는 최근까지 토양 매질체에서 탄소나노물질의 이동과 관련하여 수행된 연구들을 정리하였다. 또한, 이러한 연구들을 통해 알려진 탄소 나노물질의 이동에 영향을 미치는 인자들을 제시하였다. 그리고, 탄소나노물질의 이동을 모사하는데 이용되는 DLVO이론, 콜로이드 여과이론 그리고 이동모델을 제시하였다. 최근, 국내에서도 탄소나노물질의 생산과 상업적, 환경적 이용이 급속히 증가하고 있다. 따라서, 국내에서 생산되고 유통되는 탄소나노물질의 토양환경에서 이동에 관한 연구들이 향후에도 다양한 토양 환경조건에서 수행되어야 할 것으로 보인다. Carbon nanomaterials such as fullerene, carbon nanotube and graphene are representative nanomaterials and widely used in various fields. Carbon nanomaterials can be exposed to environments during their production, usage and disposal, spreading to different systems and posing a great threat to various ecological receptors. Researches are conducted in order to determine the possibility of groundwater exposure to carbon nanomaterials due to their release and passage through soils. If soils can play a significant role in limiting the transport of carbon nanomaterials, the possibility of groundwater exposure to carbon nanomaterials can be reduced greatly. This review paper presented the research works performed for the mobility of carbon nanomaterials in soil media. Also, the paper provided the factors affecting the transport of carbon nanomaterials in soil media along with the DLVO theory/colloid filtration theory/transport model, which are used to describe the transport of carbon nanomaterials in soil media. Recently, production of carbon nanomaterials and their commercial and environmental applications increase rapidly in Korea. Therefore, researches regarding the fate and transport of domestic carbon nanomaterials in soil environments should be performed in various environmental conditions.