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Microstructure and Optical Properties of Yttrium-doped Zinc Oxide(YZO) Nanobolts Synthesized by Hydrothermal Method

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Journal of Materials Science & Technology 2016年第1期32卷 12-16页

作者： Sanjeev K.Sharma Deuk young kim Semiconductor Materials and Device Laboratory Department of Semiconductor ScienceDongguk University-Seoul

In this work, yttrium-doped zinc oxide （YZO） nanopowder was synthesized via hydrothermal precipitation- method. The microstructure and optical properties of yttrium-doped zinc oxide nanopowder were characterized, which confirmed the well-crystalline wurtzite hexagonal phase of ZnO. The yttrium- doped zinc oxide nanopowder grains formed the nanobolts of -400 nm in length and -900 nm in width. High resolution-transmission electron microscopy （HR-TEM） of the nanobolts revealed uniform lattice fringes and no visible faults and/or distortions. X-ray photoelectron spectroscopy （XPS） analysis con- firmed the presence of yttrium in the zinc oxide lattice, proving the contribution of yttrium on the microstructural and optical properties of the material. A strong ultra violet （UV） emission peak of the YZO exhibited a red shift compared to pure zinc oxide, which was ascribed to the defects and the for- mation of a shallow energy level caused bv the incorporation of yttrium.

关键词： YZO nanobolts Hydrothermal synthesis Microstructural Optical properties

Spatial Fourier-decomposition optical fluorescence tomography-theoretical investigation

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Chinese Optics Letters 2008年第9期6卷 665-668页

作者：刘诚 Dug young kim 朱健强 Physics Department of Xuzhou Normal University Gwangju Institute of Science and Technology.Gwangju South Korea Shanghai Institute of Optics and Fine Mechanics.Chinese Academy of Sciences

A new three-dimensional （3D） optical fluorescent tomographic imaging scheme is proposed with structured illumination and spatial Fourier-domain decomposition methods for the first time. In this spatial Fourierdecomposition optical fluorescence tomography （SF-OFT）, the intensity of focused excitation light from an objective lens is modulated to be a cosine function along the optical axis of the system. For a given position in a two-dimensional （2D） raster scanning process, the spatial frequency of the cosine function along the optical axis sweeps in a proper range while a series of fluorescence intensity are detected accordingly. By making an inverse discrete cosine transformation of these recorded intensity profiles, the distribution of fluorescent markers along the optical axis of a focused laser beam is obtained. A 3D optical fluorescent tomography can be achieved with this proposed SF-OFT technique with a simple 2D raster scanning process.

关键词： Diagnostic radiography Fluorescence Image coding Light emission Light measurement Luminescence Medical imaging Scanning Three dimensional Tomography

Preparation and Characterization of Porous PVdF-HFP/clay Nanocomposite Membranes

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Journal of Materials Science & Technology 2010年第7期26卷 633-638页

作者： Mi Jin Koh Hae young Hwang Deuk Ju kim Hyeng Jun kim young Taik Hong Sang Yong Nam School of Materials Science and Engineering Engineering Research Institutei-Cube CenterGyeongsang National UniversityJinjuKorea Fuel Cell Research Center Korea Institute of Science and TechnologySeoul 136-791Korea Energy Material Research Center Korea Research Institute of Chemical TechnologyDaejeon 305-600Korea

Polyvinylidene fluoride-hexafluoropropylene （PVdF-HFP） / clay nanocomposite membranes were prepared by phase inversion method through controlling retention time to apply for a lithium ion secondary batteries. Increased membrane porosity with macrovoids was observed at increasing retention time. Partially intercalated structures of PVdF-HFP/clay nanocomposite membranes were confirmed by X-ray diffraction （XRD） analysis. PVdF-HFP membranes containing various kind of clay showed the increase of membrane modulus compared to the pristine PVdF-HFP membrane.

关键词： PVdF-HFP Porosity Mechanical properties Clay Separator

Hormonal replacement therapy and aging: Asian practical recommendations on testosterone supplementation

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Asian Journal of Andrology 2003年第4期5卷 339-344页

作者： young Chan kim Yonsei University College of Medicine Korean Sexual and Men's Health Center 135-911 Seoul Korea

Profound and diffuse alterations in the production of gonadal and adrenal androgens as well as growth hormone are associated with aging. To convey this concept more appropriately, partial endocrine deficiency in the aging male (PEDAM) was introduced as a term for the phenomenon of hormonal alterations in the aging male. Hormones responsible for some of the manifestations associated with male aging are testosterone, growth hormone, dehydroepiansdrosterone (DHEA), melatonin, thyroid hormones and leptin. Of these, testosterone has been widely investigated and its beneficial and adverse effects on male bodily systems are relatively well established. However, a serious body of confusion and misunderstandings surrounding the diagnosis, treatment and monitoring of men suspected of having androgen deficiency has been raised. Therefore, it is timely to provide practical criteria for diagnosis and treatment to avoid misconception about the use of testosterone in the aging male. To provide an understanding and information of the issues, the following headings are summarized: (1) Important clinical consideration on testosterone supplementation in the aging male; (2) Asian practical recommendations on testosterone supplementation in the aging male.

关键词： hormone alteration recommendation testosterone supplementation aging male

Adsorption of phosphate on magnetite-enriched particles (MEP) separated from the mill scale

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Frontiers of Environmental Science & Engineering 2019年第5期13卷 81-92页

作者： Muhammad Kashif Shahid Yunjung kim young-Gyun Choi Department of Environmental Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Mechanical Process Research Group Engineering CenterPOSCO E&CIncheon 220099Republic of Korea

Phosphate is a major pollutant in water, causing serious environmental and health consequences. In present study, the phosphate adsorption on novel magnetite-enriched particles (MEP) was comprehensively investigated. A new method and device were introduced for the separation of MEP from the mill scale at low magnetic intensity. Particles were characterized with different techniques such as XRD, XRF, SEM and EDS. The XRD and XRF analysis of MEP identified the dominant existence of crystalline magnetite. Furthermore, the morphological analysis of MEP confirmed the agglomerate porous morphology of magnetite. Oxygen and iron, the main constituents of magnetite were acknowledged during the elemental analysis using EDS. The phosphate adsorption on MEP is well explained using various isotherm and kinetic models, exhibiting the monolayer adsorption of phosphate on the surface of MEP. The maximum adsorption capacity was determined 6.41 mg/g. Based on particle size (45–75 and 75–150 μm) and empty bed contact time (1 and 2 h), four columns were operated for 54 days. MEP were appeared successful to remove all phosphate concentration from the column influent having 2 mg/L concentration. The operated column reactors were successfully regenerated with alkaline solution. The results indicated potential for practical application of the MEP for phosphate removal.

关键词： Adsorption Magnetite Mill-scale Phosphate Wastewater treatment

Investigation of long-wavelength elastic wave propagation through wet bentonite-filled rock joints

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2496-2507页

作者： Ji-Won kim Song-Hun Chong Jin-Seop kim Geon-young kim Disposal Performance Demonstration R&D Division Korea Atomic Energy Research InstituteDaejeon34057Republic of Korea Department of Civil Engineering Sunchon National UniversitySuncheon57922Republic of Korea

The saturation of the compacted bentonite buffer in the deep geological repository can cause bentonite swelling,intrusion into rock fractures,and ***,erosion and subsequent bentonite mass loss due to groundwater inflow can aggravate the overall integrity of the engineered barrier ***,the coupled hydro-mechanical interaction between the buffer and rock during groundwater inflow and bentonite intrusion should be evaluated to guarantee the long-term safety of deep geological *** study investigated the effect of bentonite erosion and intrusion on the elastic wave propagation characteristics in jointed rocks using a quasi-static resonant column *** rock specimens with different joint conditions(*** surface saturation and bentonite filling)were prepared using granite rock discs sampled from the Korea Underground Research Tunnel(KURT)and Gyeongju *** long-wavelength longitudinal and shear wave velocities were measured under different normal stress levels.A Hertzian-type power model was used to fit the wave velocities,and the relationship between the two fitted parameters provided the trend of joint *** simulations using three-dimensional distinct element code(3DEC)were conducted to better understand how the long-wavelength wave propagates through wet bentonite-filled rock joints.

关键词： Engineered barrier system Bentonite erosion and intrusion Jointed rock mass Long-wavelength elastic wave velocity Quasi-static resonant column test Three-dimensional distinct element code(3DEC)

Computed tomographic differentiation between alcoholic and gallstone pancreatitis:Significance of distribution of infiltration or fluid collection

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World Journal of Gastroenterology 2006年第28期12卷 4524-4528页

作者： young-Sun kim Yongsoo kim Sung-Kyu kim Hyunchul Rhim Department of Radiology and Center for Imaging Science Samsung Medical CenterSungkyunkwan University School of MedicineSeoulSouth Korea Department of Diagnostic Radiology Hanyang University College of MedicineGuri-citySouth Korea Yeongdeungpo Imaging Center SeoulSouth Korea

AIM： To evaluate the usefulness of various computed tomography （CT） findings including distribution of infiltration or fluid collection in differentiating the major etiologies of acute pancreatitis. METHODS： We reviewed 75 relatively severe cases of acute pancreatitis of alcoholic （n = 43） or biliary stone （n = 32） etiology having infiltration or fluid collection on CT. We compared the pancreatic size, CT grading, presence or absence of biliary calculi, and dilatation of pancreatic or bile duct. We also evaluated degree and the distribution of infiltration and fluid collection in each group. RESULTS： The sizes of pancreas were not different between alcohol group and stone group. Alcohol group showed higher CT grading than stone group （P 〈 0.05）. Presence of biliary stone and duct dilatation was statistically significant in differentiating etiology （P 〈 0.05）. Alcohol group showed significantly prominent peripancreatic pathology than stone group only in left peritoneal compartment （P = 0.020）. CONCLUSION： Alcoholic pancreatitis tends to form more prominent peripancreatic changes than gallstone pancreatitis in relatively severe cases. This is evident on the anterior aspect of left abdomen. Although clinical history and some CT findings usually are a major determinant of the etiology, this pattern of peripancreatic pathology may have an ancillary role in determining the etiologies of acute pancreatitis in the equivocal cases.

关键词： Pancreatitis Pancreas Computed tomography Peritoneum Fluid Retroperitoneal space

MRI of gastric carcinoma:Results of T and N-staging in an in vitro study

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World Journal of Gastroenterology 2009年第32期15卷 3992-3998页

作者： Il young kim Sang Won kim Hyeong Cheol Shin Moon Soo Lee Dong Jun Jeong Chang Jin kim young Tong kim Department of Radiology Soonchunhyang University Cheonan Hospital23-20 BongmyungdongCheonanChoongnam 330-720South Korea Department of Surgery Soonchunhyang University Cheonan Hospital23-20 BongmyungdongCheonanChoongnam 330-720South Korea Department of Pathology Soonchunhyang University Cheonan Hospital23-20 BongmyungdongCheonanChoongnam 330-720South Korea

AIM： To determine the accuracy of 1.5-T magnetic resonance imaging （MRI） in the evaluation of gastric wall invasion and perigastric lymph node metastasis in gastric adenocarcinoma.METHODS： Twenty resected gastric specimens containing 20 tumors were studied with a 1.5-T MR system using a commercial head surface coil. MR scanning was performed with a T1 weighted image （TR/TE = 500/20）, and a T2 weighted image （TR/TE = 2500/90）. MR findings were compared with pathologic findings.RESULTS： A T1-weighted image demonstrated three layers in the normal gastric wall. All of the gastric tumors were well demonstrated by lesions and location. In a MRI findings of gastric wall invasion, there was 1 case of T1, 7 of T2, 11 of T3. Pathologic results of resected specimens included 3 cases of pT1, 4 of pT2, and 12 of pT3. The accuracy of T staging with MRI was 74% （14 of 19）. MRI findings of lymph node metastasis included 6 cases of NO, 13 cases of N1. The accuracy of the N staging with MRI was 47% （9 of 19）.CONCLUSION： MRI has a high diagnostic accuracy in the evaluation of the T staging of gastric cancerin vitro and thus potentially enables preoperative histopathologic staging.

关键词： Gastric cancer Magnetic resonance imaging Neoplasm Staging Stomach Depiction of walllayer

Advanced polymer materials-based electronic skins for tactile and non-contact sensing applications

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InfoMat 2023年第7期5卷 1-42页

作者： Feifei Yin Hongsen Niu Eun-Seong kim young Kee Shin Yang Li Nam-young kim Department of Electronics Engineering Kwangwoon UniversitySeoulRepublic of Korea Department of Molecular Medicine and Biopharmaceutical Sciences Seoul National UniversitySeoulRepublic of Korea School of Information Science and Engineering University of JinanJinanthe People's Republic of China

Recently,polymer materials have been at the forefront of other materials in building high-performance flexible electronic skin(e-skin)devices due to con-spicuous advantages including excellent mechanical flexibility,good compatibil-ity,and high ***,most research works just paid considerable attention and effort to the design,construction,and possible application of e-skins that reproduce the tactile perception of the human skin sensory *** with tactile sensing devices,e-skins that aim to imitate the non-contact sensing features in the sensory system of human skin tend to avoid undesired issues such as bacteria spreading and mechanical *** further promote the development of e-skins to the human skin sensory system where tactile perception and non-contact sensing complement each other,significant progress and advances have been achieved in the field of polymer materials enabled e-skins for both tactile perception and non-contact sensing *** this review,the latest progress in polymer material-based e-skins with regard to tactile,non-contact sensing capabilities and their practical applications are *** fabrication strategies of polymer materials and their role in building high-performance e-skins for tactile and non-contact sensing are ***,we also review the research works that integrated the polymer-based tactile and non-contact e-skins into robots and prostheses,smart gloves,and VR/AR devices and addressed some representative problems to dem-onstrate their suitability in practical applications in human–machine ***,the current challenges in the construction of high-performance tactile and non-contact e-skins are highlighted and promising properties in this direction,by taking advantage of the polymer materials,are outlined.

关键词： electronic skins human-machine interaction non-contact sensing polymer materials tactile sensing