• Applied Microscopy
• /
• v.8 no.1
• /
• pp.81-90
• /
• 1978

Introduction of electron microscope in biological and medical sciences change the concept of functional and morphologic unit of biological phenomena from the cell to subcellular unit, and it formulated the basis for molecular biology and pathology. Until recently, electron microscopy has mainly been applied to basic research works. However, practical clinical application of electron microscopy is being actively tried. The major clinical fields in which electron microscopy is helpful or even essential include viral diseases, metabolic diseases, glomerular diseases and in the identification of certain types of neoplasms. A brief introduction of characteristics of each conditions are made to encourage more active application of electron microscopy in clinical medicine.

• Journal of Convergence for Information Technology
• /
• v.9 no.9
• /
• pp.252-257
• /
• 2019

We investigated the microstructure and morphological characteristics of microplastics added to rinse off cosmetics by scanning electron microscope. The size of the microplastic was in a wide range of sizes, from $250{\mu}m$ to 1.5mm in diameter. The small microplastics were in the shape of elongated particles and the large microplastics were cuboidal. Most cubic microplastics were observed in the form of squares or rectangles. The surface of the cubic microplastic was smoothly observed without protruding portions, but irregularly many gaps were formed. The gap between openings was measured from about $5{\mu}m$ to $20{\mu}m$. It has not been confirmed that these gaps are formed from the surface of the microplastic to the inside there of.

• Journal of the Korean Ceramic Society
• /
• v.50 no.6
• /
• pp.518-522
• /
• 2013

This study investigatesthe coloration mechanism by identifying the factor that affects thered coloration of copper red glazesin traditional Korean ceramics. The characteristics of the reduction-fired copper red glaze's sections are analyzed using an optical microscope, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The sections observed using an optical microscope are divided into domains of surface, red-bubble, and red band. According to the Raman micro spectroscopy analysis results, the major characteristic peak is identified as silicate in all three domains, and the intensity of $Cu_2O$ increases toward the red band. In addition, it is confirmed that the most abundant CuO exists in the glaze bubbles. Moreover, CuO and $Cu_2O$ exist as fine particles in a dispersed state in the surface domain. Thus, Cu combined with oxygen is distributed evenly throughout the copper red glaze, and $Cu_2O$ is more concentrated toward the interface between body and glaze. It is also confirmed that CuO is concentrated around the bubbles. Therefore, it is concluded that the red coloration of the copper red glaze is revealed not only through metallic Cu but also through $Cu_2O$ and CuO.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.2
• /
• pp.171-175
• /
• 2014

In this study, we suggest a method to measure the thickness of thin films nondestructively using the dispersion characteristics of a surface acoustic wave propagating along the thin film surface. To measure the thickness of thin films, we deposited thin films with different thicknesses on a Si (100) wafer substrate by controlling the deposit time using the E-beam evaporation method. The thickness of the thin films was measured using a scanning electron microscope. Subsequently, the surface wave velocity of the thin films with different thicknesses was measured using the V(z) curve method of scanning acoustic microscopy. The correlation between the measured thickness and surface acoustic wave velocity was verified. The wave velocity of the film decreased as the film thickness increased. Therefore, thin film thickness can be determined by measuring the dispersion characteristics of the surface acoustic wave velocity.

• Applied Microscopy
• /
• v.20 no.2
• /
• pp.12-22
• /
• 1990

The morphological characteristics and changes of the foregut in the grasshopper (Oxya sinuosa Mistshenko) have been studied with the special reference to the developmental stage. In light microscope level, the epithelia are seen the cuboidal shape in the 5th instar nymph and the adult. A number of pigment granules are appeared in the cuboidal epithelium of the 5th instar nymph, however the pigment granules were a few in the adult. Indistinct or undifferentiated folds of the epithelial layer were appeared in the 5th instar nymph, whereas the well-developed folds were in the adult. The well-developed muscular layers are seen in the 5th instar nymph, however in the adult the muscular layers are appeared thin or a few layer except the crop. In electron microscope level, in the foregut epithelium, a few round or oval shaped mitochondria, well-developed rER, Golgi complex, lysosome and a number of vacuoles were appeared in the cytoplasm. Two types of pigment granules, electron dense or homogenous and low electron dense or lamellar profiles, are seen in the esophageal epithelium. The crystalline profiles and plasma membrane infoldings were also appeared. In the foregut epithelium of the 5th instar nymph, however the cell organelles were generally undifferentiated and in the crop two types of pigment granules as the adult esophageal epithelium were also found.

• Animal cells and systems
• /
• v.3 no.4
• /
• pp.407-412
• /
• 1999

The influence of eating habits and food type on the ultrastructural characteristics of the digestive tracts was studied under the scanning and transmission electron microscopes in two crustacean decapods (Hemigrapsus penicillatus De Haan; mud crab, Pinnotheres cyclinus Shen; symbiotic crab). The relative ratio of the length of midgut versus hindgut was 1:1 in the mud crab, but 4:1 in the symbiotic crab. Observation through the scanning electron microscope revealed that the midguts of both species have densely-arranged longitudinal mucosal folds with a smooth surface. In the hindgut of the mud crab, mucosal folds were longitudinally oriented, clusters of two to five spines were observed on the cuticular surface, and the length of the spine in the distal hindgut was longer than that in the proximal portion. In the symbiotic crab, the mucosal folds were irregulary arranged, and numerous rudimentary spinal structures were noted on the cuticular surface. Through observation of a transmission electron microscope, the epithelial cells of the midgut in both species had numerous microvilli, but the length of the microvilli was slightly longer in the mud crab than in the symbiotic crab. The central layer of the basement membrane and the muscular layer of the midgut were more developed in the mud crab than in the symbiotic crab. The thickness of the cuticular layer over the hindgut surface in the mud crab was about 4 times than that of the symbiotic crab.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.1
• /
• pp.85-97
• /
• 2000

The purpose of this study was to compare the corrosion characteristics between implant fixture and two types of abutment screw ; gold screw, titanium screw. The anodic polarization behavior, the galvanic corrosion behavior, and the crevice corrosion behavior of prepared samples were investigated using potentiostat and scanning electron microscope. The results were as follows: 1. Anodic polarization behavior of samples; The primary passivation potential of implant fixture was -420mV, implant abutment was -560mV. titanium screw was -370mV and gold screw was -230mV. All samples were shown to have a high corrosion potential and good formation of passive film. The critical passive current density of gold screw was higher than that of other samples and the sample of gold screw showed a unstable passive film formation at passive region. 2. Galvanic corrosion behavior of samples; Contact current density between implant fixture and titanium screw showed $8.023{\times}10^{-5}C/cm^2$. Contact current density between implant fixture and gold screw showed $5.142{\times}10^{-5}C/cm^2$. 3. Crevice corrosion behavior of samples; The crevice corrosion resistance of sample using titanium screw was higher than that of sample using gold screw, and a severe corrosion morphologies were observed at the fixture-screw interface by the scanning electron microscope.

• Journal of the Korean Applied Science and Technology
• /
• v.28 no.3
• /
• pp.290-298
• /
• 2011

Natural Omija belongs to magnoliaceae was known to possess natural odor, taste, color, and various pharmaceutical & chemical characteristics. Omija extraction was extracted using ethanol as a solvent. Omija extract showed a light red-violet color of viscous liquid state. Some conclusions from the result of characteristic experiment were obtained as follows. From the result of antimicrobial experiment, occurrence of staphylococuss aureus and aspergillus niger as microbes was decreased according to the passage of time. This phenomenon could know that Omija component is affected to antimicrobial effect. From the result of dye experiment, fiber dyeing showed with some ivory color after dyed to cotton and silk. This phenomenon could know that Omija component is affected to dyeing effect from observation of scanning electron microscope(SEM). From the result of instrument analysis, inorganic components of K(107.30ppm), Na(2.110ppm), Ca(0.935ppm), Mg(0.891ppm), Li(0.270ppm) etcs from Omija were detected with ICP/OES, and aromatic components of benzene(10.808), a-pinene(13.996), phenol(14.183), ${\beta}$-terpene(15.840), a-terpinolene(17.616) etcs from Omija were also detected with GC/MSD.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.10 s.175
• /
• pp.121-128
• /
• 2005

The research on electromagnetic shielding has been advanced for military applications as well as for commercial products. Utilizing the reflective properties and absorptive properties of shielding material, the replied signal measured at the rear surface or at the signal source can be minimized. The shielding effect was obtained from materials having special absorptive properties and structural characteristics such as stacking sequence. Recently researchers studied the electromagnetic properties of nano size particles. In this research {glass fiber}/{epoxy}/{nano particle} composites(GFR-Nano composites) was fabricated using various nano particles, and their properties in electromagnetic shielding were compared. For the visual observation of the nano composite materials, SEM(Scanning Electron Microscope) and TEM(Transmission Electron Microscope) were used. For the measurement of electromagnetic shielding, HP8719ES S-parameter Vector Network Analyser System was used on the frequency range of 8 GHz${\~}$12GHz. Among the nano particles, carbon black and Multi-Walled Carbon Nano-Tube (MWCNT) revealed outstanding electromagnetic shielding. Although silver nano particles (flake and powder) were expected to have effective electromagnetic shielding due to their excellent electric conductivities, test results showed little shielding characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.10
• /
• pp.1326-1338
• /
• 1997

Electrical characteristics of soot particles in a LPG diffusion flame were studied for the control of soot particle coagulation. When a DC voltage was applied between two electrodes installed parallel to gas flow, ionic wind effect caused soot deposition on the cathode, implying that most of the soot particles were positively charged. Soot deposit on the cathode linearly increased and was saturated with respect to the strength of the applied voltage. The possibility of applying an AC voltage to enhance the particle coagulation was then investigated and the efficiency of the size control was checked with transmission electron microscope photographs. For the amplitude of 2 kV AC field, primary (spherical) soot particle size decreased from 30 ~ 40 nm to around 20 nm when the frequency of the applied AC voltage was 60 Hz and higher. Collisions between the soot particles in such a selected AC condition could lead to the formation of much bigger agglomerates of roughly 1-5 .mu.m in size.