• Applied Microscopy
• /
• v.1 no.1
• /
• pp.11-17
• /
• 1969

Conidio spores of Aspergillus niger (strain No. NRRL 330) cultured on potato dextrose agar media were studied by electron microscopy, using the thin sectioning techniques. Conidio spores to be sectioned were fixed by triple methods with $K_2Cr_2O_7$, Glutaraldehyde and $OsO_4$. After dehydrated with alcohol, the specimens were embedded in metacrylate and epon resin media, and thinly sectioned by Porter-Blum MT-2. After sectioned these specimens were negative-stained with uranyl acetate and observed. by Hitachi HS-6 electron microscope. The results of this experiment were summarized as follows. 1. The structures of spore ,wall system seem to be formed 4 layers; exosporium, basal layer, spore coat and unit cell membrane. The protuberance of spore surface that was looked like hair appears to be protrusived from the basal layer. 2. The 3 layers of unit cell membrane was constituted outer layer membrane, inner layer membrane and inter-mediate light layer. 3. The structures of intra cytoplasmic membrane appear as spiral form which was consisted of 3 layers membrane system; outer membrane, inner membrane, and intermediate layer, which has pits. 4. The cement substance of spore coat and cortex may be changed quantitatively by physiological state in cell. 5. In some cases, we observed that the ribosome was transformed into poly ribosome group, and the storage materials and the protein crystals were changed variously. It. has been suggested that the morphological change of some cytoplasmic materials may be caused by some specialized function of the physiological stage.

• Current Photovoltaic Research
• /
• v.9 no.4
• /
• pp.137-144
• /
• 2021

In this study, the microstructure of the CVD-fabricated Cu(In,Ga)Se₂ (CIGSe) absorber layer by simulating the stacking sequence used in a co-evaporation method, and changes solar cell performance were investigated. The absorber layer prepared by stacking CuSe and (In,Ga)Se between InSe is separated into Ga-free CuInSe₂ and Ga-rich CIGSe, and transformed to CIGSe by selenization heat treatment with slight improvement in the the solar cell efficiency. However, in CVD, since the supply of liquid Cu-Se is not as active as in the co-evaporation method, the nanoocrystalline layer containing a large amount of Ga remained independently in the absorption layer, which acted as a cause of the loss of J_SC and FF. Therefore, by using a precursor structure in which CuGa is sputter-deposited on a single layer of InSe deposited by CVD, performance parameters of V_OC, J_SC, and FF could be greatly improved.

• Journal of the korean society of oceanography
• /
• v.32 no.1
• /
• pp.8-16
• /
• 1997

The ventilation theory developed by Luyten, Pedlosky and Stommel (1983) is applied to the East Sea to understand the general circulation pattern of the Intermediate Water, especially the ventilated circulation beneath the Tsushima Warm Current. The original model is slightly modified such that it takes the inflow-outflow of the Tsushima Current into consideration. Results of the model indicate that for sufficiently strong Ekman pumping, the Intermediate Water circulates cyclonically by ventilation. The Intermediate Water subducts beneath the Tsushima Warm Water through the western boundary layer. Off the western boundary layer, it turns northward, outcrops to the north by passing the polar front and continues to flow northward until it finally is absorbed by the northern boundary layer. This result seems to be compatible with some recent observations. Over the ventilated area, the transport of the Tsushima Current is negligible and most transport occurs in the shadow area where the Intermediate layer is motionless indicating that, over the deep motionless layer, the two-layered vertical structure under consideration becomes substantially single-layered.

• Korean Journal of Hydrosciences
• /
• v.4
• /
• pp.93-104
• /
• 1993

This paper is concerned with the actual comparison analysis for the freshening process in the two selected experimental reservoirs. At the deep freshening reservoir, salinity and depth of the freshwater layer were estimated by simulation technique using the quantitative equation for the two layered flow structures. First of all, it is shown that the effects of underdraiange conduit in the lower layer were reported more effective for the control of upper layer salinity comparing with the case of no underdraiange conduit. Further the results of computation were later compared with the real observed values and the relating parameters of the salt balance equation are conformed even though approximately. Finally it was represented that the salinity of upper layer is easily diluted not only by the tidal gate but also by the underdraiange conduit in the lower layer of the freshening reservoir.

• Journal of electromagnetic engineering and science
• /
• v.5 no.4
• /
• pp.183-188
• /
• 2005

A simple microwave backscattering model for vegetation canopies on earth surfaces is developed in this study. A natural earth surface is modeled as a two-layer structure comprising a vegetation layer and a ground layer. This scattering model includes various scattering mechanisms up to the first-order multiple scattering( double-bounce scattering). Radar backscatter from ground surface has been modeled by the polarimetric semi-empirical model (PSEM), while the backscatter from the vegetation layer modeled by the vector radiative transfer model. The vegetation layer is modeled by random distribution of mixed scattering particles, such as leaves, branches and trunks. The number of input parameters has been minimized to simplify the scattering model. The computation results are compared with the experimental measurements, which were obtained by ground-based scatterometers and NASA/JPL air-borne synthetic aperture radar(SAR) system. It was found that the scattering model agrees well with the experimental data, even though the model used only ten input parameters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.04c
• /
• pp.42-44
• /
• 2008

In this study, we report an electrical properties of green OLEO, using the changed thickness of Al Layer. We investigated the electrical properties of OLEOs by IVL and optical properties by EL spectrum. The fundamental structure of green OLEOs was ITO anode/TPD($400{\AA}$)/$Alq_3(600{\AA})$)/LiF($10{\AA}$)/Al($200{\sim}600{\AA}$) cathode. The threshold voltage was low value according to the more thin Al layer. The luminance was increased by decreased cathode layer. The threshold voltage was 12V and wavelength was 530nm at $200{\AA}$ cathode.

• Journal of Welding and Joining
• /
• v.10 no.4
• /
• pp.181-189
• /
• 1992

The purpose of this investigation is to examine the effects of the strengthening treatments on the mechanical properties of the flame-sprayed titania ceramic coating layer. The strengthening treatments for flame sprayed specimens were carried out in 12 different conditions in vaccum furance. The mechanical properties such as microhardness, thermal shock resistance, adhesive strength and erosion resistance were tested for the sprayed specimens after strengthening treatments. And it was clear that the mechanical properties of coating layer were much improved by the strengthening treatments. The results obtained are summarized as follows; 1. It was shown that the metallurgical bond was formed between substrate and coating layer by the strengthening treatments and that thermal shock resistance and adhesive strength were remarkably raised. 2. Microhardness of coating lay was considerably increased by the strengthening treatments. 3. Erosion resistance and porosity of coating layer were slightly improved by the strengthening treatments.

• Proceedings of the KWS Conference
• /
• 2006.10a
• /
• pp.120-122
• /
• 2006

This study deals with characterizations of microstructure and wear performance of a cladding layer, product on 1.9 mm-thick mild steel plate by the electric resistance welding, of composite metal powder of Coarse WC-6.5%Co and high carbon alloy(SHA). The cladding layer was examined and tested fur microstructural features, chemical composition, hardness, wear performance and wear mechanism. The cladding layer have two different matrix were observed by an optical microscope and EPMA. The one was the coarse WC-6.5Co structure. The other was the melted SHA with surrounding the WC-6.5Co structure. The hardness of WC-6.5Co was 1210HV. The hardness of SHA was 640HV. In comparison by wear rate, the cladding layer showed the remarkable wear performance that was 15 times of SM490 and about 62% of D2.

• Current Optics and Photonics
• /
• v.4 no.2
• /
• pp.141-147
• /
• 2020

To understand the cause of the high light transmittance of the human eye, the optical effects of the collagen fibers of the stroma layer, which constitute the majority of the cornea, were analyzed. These collagen fibers, approximately 20 nm in diameter, have a regular arrangement. Accordingly, the optical properties of the collagen fibers and the fiber layer were analyzed by simulation. A standing wave was formed in the incident space by the overlapping incident light and the light reflected by the plate. In addition, it was confirmed that when the collagen fibers are arranged in a layer, the light transmittance periodically changes, depending on the number of fiber layers. The standing wave was formed in the incident space, and the light's intensity distribution was changed by the nanoscale collagen fibers in the section with the collagen layer, which affected the transmittance. To explain this phenomenon, the collagen fiber was defined as a second light source, and an attempt was made to describe the simulation results in terms of overlap of the incident light with the light emitted from the collagen fiber.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.2
• /
• pp.131-134
• /
• 2011

In this study, we propose an optimal design and new fabrication method for a slim tactile sensor. Slim tactile sensor can detect 3-axial forces and has suitable flexibility for intelligent robot fingers. To amplify the contact signal, a unique table-shaped structure was attempted. A new layer-by-layer fabrication process for polymer micromachining that can make a 3D structure by using a sacrificial layer was proposed. A table-shaped epoxy sensing plate with four legs was built on top of a flexible polymer substrate. The plate can convert an applied force to a concentrated stress. Normal and shear forces can be detected by combining responses from metal strain gauges embedded in the polymer substrate. The optimal positions of the strain gauges are determined using the strain distribution obtained from finite element analysis.