• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.2
• /
• pp.164-169
• /
• 2002

This paper reports on design and fabrication of near field probe operating at 300~3000 MHz. Design parameters are extracted by equivalent circuit of E-field probe and simulation using S parameter is performed to predict probes performance. The probe consists of a dipole antenna with 3.25 mm length, a zero bias Schottky diode and a highly resistive transmission line. A TEM cell was used for performance evaluation.

• Journal of Environmental Science International
• /
• v.9 no.4
• /
• pp.331-337
• /
• 2000

The variation of microorganisms (activated slude, Saccharomyces cerevisiae, Aureobasidium pullulans) caused by the biosorption of $Pb^{2+}$ was observed by TEM and microscope. By the TEM observation of S. cerevisiae, the plasmolysis and lysis of cell wall or cell membrane were occurred by the penetration of $Pb^{2+}$ into the inner cellular region. However, in the case of A. pullulans, the plasmolysis and lysis of cell wall or cell membrane were not occurred because of the prevention of $Pb^{2+}$ penetration by the extracelluar polymeric substances (EPS). A flocculation of microorganisms, in the case of A. pullulans, was observed by the $Pb^{2+}$ accumulation after 3~4 h and the color was changed from white to black after 1 day. The flocculation of activated sludge was improved by the accumulation $Pb^{2+}$ after 1 h, however, the floc was broken up and the settling efficiency decreased after 1 day.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.2
• /
• pp.9-15
• /
• 2007

A comparative study of the structure and organization of the primary and secondary walls in different types of tropical plant waste fibers was carried out using transmission electron microscopy (TEM). The thickness of each layer was also measured using Image Analyzer. TEM micrographs haveconfirmed that cell wall structure of all six types of tropical plant waste fibers (empty fruit bunch, oil palm frond, oil palm trunk, coir, banana stem and pineapple leaf) has the same ultrastructure with wood fibre. The fibers consisted of middle lamella, primary and thick secondary wall with different thickness for different types of fibers. The secondary wall was differentiated into a $S_1$ layer, a unique multi-lamellae $S_2$ layer, and $S_3$ layer.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.10
• /
• pp.1354-1367
• /
• 2014

In the present work, we describe a simple, cheap, and unexplored method for "green" synthesis of silver nanoparticles using cell extracts of the cyanobacterium Anabaena doliolum. An attempt was also made to test the antimicrobial and antitumor activities of the synthesized nanoparticles. Analytical techniques, namely UV-vis spectroscopy, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and TEM-selected area electron diffraction, were used to elucidate the formation and characterization of silver-cyanobacterial nanoparticles (Ag-CNPs). Results showed that the original color of the cell extract changed from reddish blue to dark brown after addition of silver nitrate solution (1 mM) within 1 h, suggesting the synthesis of Ag-CNPs. That the formation Ag-CNPs indeed occurred was also evident from the spectroscopic analysis of the reaction mixture, wherein a prominent peak at 420 nm was noted. TEM images revealed well-dispersed, spherical Ag-CNPs with a particle size in the range of 10-50 nm. The X-ray diffraction spectrum suggested a crystalline nature of the Ag-CNPs. FTIR analysis indicated the utilization of a hydroxyl (-OH) group in the formation of Ag-CNPs. Ag-CNPs exhibited strong antibacterial activity against three multidrug-resistant bacteria. Additionally, Ag-CNPs strongly affected the survival of Dalton's lymphoma and human carcinoma colo205 cells at a very low concentration. The Ag-CNPs-induced loss of survival of both cell types may be due to the induction of reactive oxygen species generation and DNA fragmentation, resulting in apoptosis. Properties exhibited by the Ag-CNP suggest that it may be used as a potential antibacterial and antitumor agent.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1996.06a
• /
• pp.286-290
• /
• 1996

• Proceedings of the Petrological Society of Korea Conference
• /
• 2009.05a
• /
• pp.9-9
• /
• 2009

• Korean Chemical Engineering Research
• /
• v.57 no.1
• /
• pp.111-117
• /
• 2019

This study proposed the fabrication and deposition of high purity crystalline $core-TiO_2/shell-Al_2O_3$ nanoparticles. Morphological properties of $core-TiO_2$ and coated $shell-Al_2O_3$ were confirmed by transmission electron microscope (TEM) and transmission electron microscope - energy dispersive spectroscopy (TEM-EDS). The electrical properties of the prepared $core-TiO_2/shell-Al_2O_3$ nanoparticles were evaluated by applying them to a working electrode of a Dye-Sensitized Solar Cell (DSSC). The particle size, growth rate and the main crystal structure of $core-TiO_2$ were analyzed through dynamic light scattering system (DLS), scanning electron microscope (SEM) and X-ray diffraction (XRD). The $core-TiO_2$, which has a particle size of 17.1 nm, a thin film thickness of $20.1{\mu}m$ and a main crystal structure of anatase, shows higher electrical efficiency than the conventional paste-based dye-sensitized solar cell (DSSC). In addition, the energy conversion efficiency (6.28%) of the dye-sensitized solar cell (DSSC) using the $core-TiO_2/shell-Al_2O_3$ nanoparticles selectively controlled to the working electrode is 26.1% higher than the energy conversion efficiency (4.99%) of the dye-sensitized solar cell (DSSC) using the conventional paste method.

• Applied Microscopy
• /
• v.45 no.3
• /
• pp.183-188
• /
• 2015

Due to the miniaturization of semiconductor devices, their crystal structure on the nanoscale must be analyzed. However, scanning electron microscope-electron backscatter diffraction (EBSD) has a limitation of resolution in nanoscale and high-resolution electron microscopy (HREM) can be used to analyze restrictive local structural information. In this study, three-dimensional (3D) automated crystal orientation and phase mapping using transmission electron microscopy (TEM) (3D TEM-EBSD) was used to identify the crystal structure relationship between an epitaxially grown CdS interfacial layer and a $Cu(In_xGa_{x-1})Se_2$ (CIGS) solar cell layer. The 3D TEM-EBSD technique clearly defined the crystal orientation and phase of the epitaxially grown layers, making it useful for establishing the growth mechanism of functional nano-materials.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.95-98
• /
• 1998

In this paper, we propose a cell scheduling algorithm for ABR traffic in ATM multiplexer. Proposed Algorithm can support ABR service more efficiently than existing WRR and DWRR algorithm. We evaluate the performances of proposed algorithm through computer simulation. Also, we model the VBR and the ABR traffics as ON/OFF source, and the CBR traffic as a Poisson source. And the simulation shows that proposed algorithm better performance over other cell scheduling algorithm in tem of mean cell delay time.

• Korean Journal of Animal Reproduction
• /
• v.22 no.4
• /
• pp.331-339
• /
• 1998

The purpose of this study was to investigate the applicability of periodic acid thiocarbohy-drazide silver proteinate, physical development (PA-TCH-SP, -PD) stain to the seminiferous tubules for the ultrastructural studies of Sertoli cell column and Sertoli cell processes. In the Sertoli cell cloumn and Sertoli cell processes, high concentration of the reactive granules were observed under transmission electronmicroscope (TEM) after PA-TCH-SP-PD stain. Also some reactive granules were seen in the spermatogonium cytoplasm, clearly. These reactive granules specifically stained with PA-TCH-SP, -PD make the Sertoli cell column, Sertoli cell processes and spermatogonium cytoplasm easy to distinguish from nucleus of the germ cells, spermatocyte, spermatid and residual body which did not contain the reactive granules. This result indicates that the PA-TCH-SP, -PD stain is superior to other traditional electronic double stain methods for the ultrastructural studies of Sertoli cell.