http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Synergetic effect of BN for the electrical conductivity of CNT/PAN composite fiber
Hee Jin Kim,Dae-Young Jeon,Se Gyu Jang,Min Wook Lee 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6
Carbon nanotube (CNT) fillers in composite materials improve electrical conductivity, thermal stability, and mechanical properties. Boron nitride (BN) is an insulating material that is also thermally stable. Therefore, CNT and hexagonal boron nitride (hBN) fillers have been used to obtain composite materials’ high electrical conductivity. In this study, CNThBN/polyacrylonitrile (PAN) fibers were spun using simple wet-spinning and the effect of hBN on the electrical conductivity of the CNT-hBN/PAN composite was investigated. Contrary to predictions, as the content of the insulating material, BN, increased up to 15 wt%, the electrical resistance of the composite fiber decreased.
A Simple and Quick Chemical Synthesis of Nanostructured Bi2Te3, Sb2Te3, and BixSb2-xTe3
HeeJin Kim,Ki Jung Lee,김성진,한미경 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5
We report a simple and quick route for the preparation of high-quality, nearly monodisperse Bi2Te3, Sb2Te3, and BixSb2-x-Te3 nanocrystallites. The reactions of bismuth acetate or antimony acetate with Te in oleic acid result in pure phase of Bi2Te3 or Sb2Te3 nanoparticles, respectively. Also, ternary BixSb2-xTe3 nanoparticles were successfully synthesized using the same method. The size and morphology of the nanoparticles were controlled by varying the stabilizing agents. The as-prepared nanoparticles are characterized by X-ray diffraction, scanning electron microscope, and high-resolution transmission electron microscope using an energy dispersive spectroscopy.
Hee Jin Kim,오창현,유경호 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.8
A series of new diarylamide and diarylurea derivatives possessing pyrimidinylaminobenzene scaffold was synthesized. Their in vitro antiproliferative activities were tested against A375P human melanoma cell line. Among them, compounds 1a-c, k and 2b-d, f, g, j, l showed superior potencies against A375P human melanoma cell line to Sorafenib. In particular, compound 2f possessing 3-fluoro-5-trifluoromethyl moiety exhibited the highest potency with IC50 value in nanomolar scale.
Morphology Controlled Synthesis of Nanostructured Bi2Te3
Hee-JinKim,Mi-Kyung Han,Ha-young Kim,이우영,김성진 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12
Nanostructured thermoelectric bismuth telluride (Bi2Te3) powders with various morphologies, such as nanoplates, nanorods, and nanotubes, were prepared by a hydrothermal method based on the reaction between BiCl3, Te, and sodium ethylenediaminetetraacetate (Na2-EDTA) at 150, 180, and 210 °C. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The effect of reaction temperature on the morphology of the Bi2Te3 particles was investigated, and the possible mechanism of morphology control was proposed.
The Mandible: An Atlas of Osteological and Radiological Anatomy
Hee-Jin Kim 대한해부학회 2022 Anatomy & Cell Biology Vol.55 No.1
In this book review, I would like to introduce the book ‘The Mandible’ which has recently been published in 2022. The mandible is the largest and strongest facial bone which can preserve its shape better than any other bone in the forensic and anthropologic field. The mandible is utilized to distin-guish between the ethnic groups and sexes [1]. The temporomandibular joint located between the mandib-ular head and the temporomandibular fossa allows free move-ment of the mandible which aids in chewing and digestion [2]. The mandible is inserted by the masticatory muscles, which include the masseter muscle, the temporal muscle, the medial pterygoid muscle, and the lateral pterygoid muscle. The shape of the mandible can vary according to the different lifestyles and chewing habits [3]. Therefore, the morphological charac-teristics of the mandible vary among different ethnic groups. There is very little text in this atlas. All contents are orga-nized in pictures, which is very helpful since you can intui-tively check the shape of the mandible. In chapters 1 to 4, the shape of an adult mandible can be confirmed from various angles, and in chapter 5, the human fetus specimens at 27, 28, and 29 weeks are summarized. By taking detailed pictures of the upper and lower jaws of the fetus, which cannot be eas-ily observed, you can check the appearance of the fetus’s jaw when it occurs. In addition to the general features of the mandible, several specimens can be viewed from multiple angles and various cross-sectional views. Besides the normal anatomy of the mandible, morphological variations that can be encountered in clinical practices such as the mandibular torus, elongated mental spine, and elongated coronoid process are included. Various eruption patterns of the 3rd molar are also de-picted which is beneficial when clinically extracting the third molar, which is an important part in the dental field. And this book also provides information on the mylohyoid line, external oblique ridge, and mental foramen. In addition, it provides CBCT (cone-beam computed tomography) images of the lower jaw, which can be a good guide for comprehend-ing radiographic images. Therefore, this atlas can provide osteological and radio-logical information to not only anthropologists who study bones, but also dentists or oral and maxillofacial surgeons engaged in clinical practice in this area, and researchers who specialize in this field and related research fields.
Heejin Kim,Jaesik Kang,Sangmin Kim,Chan-Ki Kim,Kyeon Hur 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6
This paper proposes an asymmetrical unipolar full-bridge submodule to protect modular multilevel converter from DC fault. The asymmetrical unipolar fullbridge submodule consists of 3 IGBTs, 4 diodes, and 2 capacitors. Central capacitor generates submodule voltage and works during normal operation. The other capacitor named a supplemental capacitor is located in the short circuit current path and charges during DC fault, effectively generating higher opposite voltage than the conventional full-bridge submodule. It thus reduces the required number of full-bridge submodules in each arm and consequently converter loss. This paper investigates DC fault blocking principles and procedures with the asymmetrical unipolar full-bridge submodule applied hybrid MMC. This paper explores the requirements of the full-bridge submodule of MMC to handle DC fault current and compares the semiconductor losses in the cases of using conventional fullbridge submodule and the asymmetrical unipolar fullbridge submodule. Simulation studies validate the efficacy of the proposed scheme.
High-performance continuous carbon fiber composite filament via solution process
Heejin Kim,Yuree Oh,황준연,문숙영,이민욱 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-
Carbon fibers and their composites are attractive materials owing to their excellent mechanicalproperties, lightweight nature, and high corrosion and high fatigue resistances. The three-dimensional(3D) printing is a promising commercial technology because it reduces the high processing cost of carbonfiber-reinforced plastics. In this study, high-performance filament composites comprising continuouscarbon fibers and nylon matrix materials were investigated. A rapid and continuous manufacturing processwas designed after determining the high impregnation condition based on a hydrodynamic analysisof a nylon solution. After performing a one-step solution process on the filament composites, individualfibers were uniformly distributed in the filament, obtaining a high packing density exceeding 90%. Surprisingly, the fabricated composite filament comprising continuous carbon fibers and nylon matricesoutperformed the pristine carbon fiber tow in terms of tensile strength. Microimages and tensile testwere investigated to further study the microstructure and mechanical behavior of the fabricated compositefilament.
( Hee-jin Kim ),( Seong-il Kim ),( Gi-won Jang ),( Sung-hyun Han ) 한국산업융합학회 2022 한국산업융합학회 논문집 Vol.25 No.2
This study proposed a new approach to impliment a robusut control of comsumerfriendly flexible manipulator with five joint for untact working in filed work-site. The output redefinition approach was used to overcome the non minimum phase characteristic of the system. The new output is defined so that the zero dynamics related to this output are stable. The control strategy is based on an computed torque method which is applicable to a class of time-invariamt phase linear systems whose uncertainties appear in output loop stable. The controller is composed of a stabilizing joint controller and an output redefinition tracking controller. Experimental results are also presented to verify the effectiveness of the proposed control scheme.