• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.219-229
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• 2020

This study evaluated the applicability of the convergence technology by deriving the optimum conditions about operating factors of electrical resistance heating to enhance the soil flushing effect on soil contaminated with bunker C oil in the coastal landfill area. As a result of the batch scale experiment, the flushing efficiency of the VG-2020 was higherthan that of the Tween-80, and the flushing efficiency increased by about 1.4 times at 60℃ compared to room temperature. As a result of the electrical resistance heating box experiment, soil temperature rose to 100℃ in about 40~80 minutes in soil with water content of 20~40%, and it was found that the heat transfer efficiency is excellent when the pipe-shaped electrode rod with STS 316 material is located in a triangular arrangement in saturated soil. In addition, it was confirmed that the interval between the electrode rods to maintain the soil temperature above 60℃ under the optimum conditions was 1.5 m, and the soil flushing box experiment accompanying electrical resistance heating showed TPH reduction efficiency of about 55% at 5 Pore Volume, and satisfied the Korean standard for the conservation of soil (less than TPH 2,000 mg/kg) at 10 Pore Volume.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.217-224
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• 1989

Four females and a male nematode isolated from 2 patients who visited eye clinics In Seoul were identified as Thelazia callipaeda and their ultrastructures were observed by scanning electron microscopy(SEM). General features of the worms were slender and attenuated at both ends. Vaginal opening was located at 0.27 mm from the anterior end, and in front of the esophagointestinal junction. In the body cuticle transverse striations varied characteristically through the body. The number of cuticular transverse striations was 400∼650/mm at head portion, 250/mm at middle portion and 300∼350/mm at tail portion. The SEM observation of the mouth part of the females showed 6 cord-like cuticular thickenings in hexagonal arrangement and an amphid was observed. A lateral line, a vaginal opening, a pair of phasmids, and an anus were identified in the body portion. A pair of papillae and 6 cord-like cuticular thickenings were on the mouth part of the male. It was difficult to observe structures at the tail of the male except wrinkle-like structures. Most of the larvae isolated from the uterus of a female worm were sheathed and thus cuticular striations were not Eren. Others were unsheathed and revealed cuticular striations. The oval membrane which encysted sheathed larvae was also observed. These are the 18th and 19th record of human thelaziasis in Korea as the literature are concerned.

• The Journal of Engineering Geology
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• v.17 no.4
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• pp.511-516
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• 2007

Active method MASW(Multi channel Analysis of Surface Waves), which is one of the surface wave exploration methods, has the difficulties to supply enough shear wave velocity log, caused by short spread length and lack of low frequency energy. To make up this defect, the passive method MASW survey is taked and analysised in Daeku subway construction site, Jungpyung-dong Gyeongsan city. The passive method MASW using the microtremor, improve the quality of the overtone record by applying the azimuth correction caused offline sources. And combing with active overtone record which is acquired by same geometry has the benefits of improve shallow depth resolution and extend possible investigation depth. To take the optimized acquisition parameters, the 2m, 4m, and 6m geophone spacing is tested. And 2m spacing overtone image could make the reliable shear wave velocity log.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.26-38
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• 1994

The purpose of this study was to evaluate the effects of citric acid and fibrin on the regeneration of periodontal tissues using 4 normal canines of five dogs. Mucoperiosteal flap was raised and experimental defects were made at the buccal root surfaces about $4{\times}6mm$ in length. The denuded root surfaces were covered using coronally repositioning technique after root planing alone at left lower canine, root planing plus fibrin at rigth lower canine, root planing plus citric acid at left upper canine or root planning plus citric acid and fibrin at right upper canine. All of the specimens were tangentially cut(about $3-5{\mu}m$)and available for histologic analysis 1, 3, 7, 14 and 21 days after operations. The results were as follows : At one' day after operations, the amounts of fibrin were similarly higher in the group I, II and III than control group and at 3 days after operations, the apical migrations of the long junctional epithelium were prominent in the control group and group I. At 7 days after operations, the fibrin meshworks of each group were partly changed to the collagen fibers and characteristics of the fibers were almost collagenous rather than fibrinous at 14 days after operations and at 21 days after operations, the orientation of collagen fibers were partly normal in group II and group III, but not in control group and group I. Root resorptions were visible in group II and group III at 14 days after operations and more significant in group II than group III at 21 days.

• Asian Journal of Turfgrass Science
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• v.18 no.1
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• pp.15-27
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• 2004

For the study of ecophysiological characteristics of ground cover plant with shade tolerance, the material productivity and the growh characteristics were analyzed in Hosta clausa community at experimental farm of Kemyung College from March to October. The installation of experimental plots were split into control plot (full sunlight), 30%, 50%, 70%, shading rate by completely randomized design method. After the transplant, to take into account the edge effect of plant population, the plants were selected from each plot by random sampling every 10days. The following results were obtained; Then number of leaf, length of leaf and width of leaf length of leafstack remarkably showed high tendency under 30%, 50% shading plot as compared with control, 70% shading plot for the exmination as the process of develpment. They showed characteristics as herbaceous ground with shade tolerance under conparatively low the light condition and they ettain a stabilized development.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.97-104
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• 2007

Present study aims to investigate the effect of muddy water on gill and kidney tissues and blood components of Opsariichthys uncirostris amurensis in Imha reservoir. As a result of observing the gill tissues in muddy water with light and scanning electron microscopes, the edema, the exfoliation of epithelial cells and fusion of the secondary lamellae were observed. The space between gill lamellae was irregular, and a lots of muddy debris around the secondary lamellae were observed. In case of kidney tissues, the size of glomerulus was smaller and thickness of basal membrane was broader and the empty space in Bowman's capsule was wider than those of the control. The blood cells of O. uncirostris amurensis in muddy water were increased in number. Of the white blood cells, acidophilic granulocytes were highly distributed, and the shapes were irregular. Among the plasma components, the concentration of TP, ALB, A/G ratio, TG, CHOL, and AST were low, whereas that of the inorganic materials was high. Based on the above results, it is considered that muddy water possibly involves in the decrease of respiratory and excretory rates, giving rise to secondary lesion of tissues.

• Journal of the Korean Geophysical Society
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• v.6 no.1
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• pp.13-23
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• 2003

Dipole-dipole resistivity and ground penetrating radar(GPR) surveys were performed on an abandoned landfill site filled with asbestos containing material. The main purpose of the study was to estimate spatial extension and volume of the landfill for evaluting the cost for developing appropriate remedial alternatives. Assuming that the bedrock is within 10 m depth, dipole spacings of 2, 2.5 and 5m were set for six survey lines for resistivity measurements. For More detailed information, GPR suvey using 225 Mhz antenna was carried out for twelve survey lines for the shallower information. DC resistivity structures showed few tens ~ hundreds ohm-m for the landfill or alluvial laver, and 1,000~ 5,000 ohm-m for the bedrock. The depth to bedrock is found out to be approximately 5m. GPR survey results represented very clear reflection and/or diffraction events from the boundaries as well as from the blocky construction wastes. With high-resolution GPR survey, depth of the bedrock was resolved up to 2m, which in turn, could be a good indicator for estimating the volume of the landfill. Those depths of bedrock were confirmed by backhoe excavation data for 13 sites. The total area and volume of the landfill were to be approximately 3,953 .$m^2$ and 4,033 $m^3$, respectively.

• Korean Journal of Optics and Photonics
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• v.20 no.6
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• pp.354-360
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• 2009

We have constructed and analyzed the performance of a simple fiber bundle multi-focal microscope. The microscope had a fiber bundle substituted for micro-lens array that is the core part of MMM(multi-focal multi-photon microscope). The MMM is a type of confocal microscope. To analyze the performance and characteristics of the fiber bundle multi-focal microscope, three types of samples were used: a standard grating, USAF 1951(7, 3), and 1951(7, 6). Using two polarizers and a polarizing beam splitter, we eliminated noise and got clear images. We obtained the FWHM of fiber spot images with the standard grating using two different magnifier lenses which were 63X and 20X, and found an image of the sample as a distribution of fiber spot images. For this case we used the low magnification lens, which gives denser distribution, so that we could get clearer images. In order to test the resolution of the fiber bundle multi-focal microscopic system, we used the USAF 1951 sample which has a smaller line interval than that of the standard grating. The FWHM of the line width of the image coincides well with the real line width of the USAF 1951 sample. We confirmed the performance of a fiber bundle multi-focal microscopic system which is relatively simple but has submicron resolution and is able to get 1600 images at the same time.

• Journal of the Korean Geophysical Society
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• v.3 no.4
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• pp.215-226
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• 2000

In order to map the acoustic basement and to locate fracture zones in the Galgok fault, seismic refraction data were acquired near the Chonbuk ranch in Gyeongju. Along three profiles of 72m(Line 1), 72m(Line 2), and 36m(Line 3) long, seismic signals were generated by a 5kg hammer. The refraction data were collected by employing twelve 8 Hz geophones at an interval of 3m and recording time of 192ms at a sampling rate of 0.2ms. The data are interpreted using GRM method. The top layer (Layer 1) is characterized as the velocity of approximately250 m/s and thickness of approximately 2.1m. This layer is regarded as a soil layer. Underneath Layer 1 lies unconsolidated layer (Layer 2) whose refraction velocity is determined to be $1,030{\sim}1,400m/s$. Layer 2 is approximately 4.6m thick and is regarded as a Quaternary gravel layer. The third layer (Layer 3) has the mean refraction velocity of $2,100{\sim}2,200m/s$ and is interpreted to be the acoustic basement. In some parts of Lines 1 and 3, the difference in depth to the top of Layer 2 is greater than 20 cm indicating the possibility of existence of Quaternary faults. Along Line 3 and the eastern part of Line 1, refracted energy from the acoustic basement was not recorded. This may highly indicate that a relatively large scale fault exists under the western part of Line 1.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.51-60
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• 2005

The disposal problem of waste lime which is a residual product of lime industry have caused a lots of arguments in the past few years. Further more, waste lime contains a high moisture content which causes the disposal of waste lime is a great difficulty. The purpose of this study is to investigate for the effective dewatering solutions by placing various prefabricated vertical drains. The moisture content and degree of consolidation, pore water pressure, changes of settlement, bearing capacity with various vertical drains in waste lime were analyzed. The laboratory test results indicate that PBD is 2 times higher than circular drain in coefficient of consolidation. Based on the laboratory test results, settlement, pore water pressure, and dewatering measurements are shown in similar tendency. It is considered that PBD can drain primitive pore water much efficiently. The picture of SEM shows that circular drain filter has a serious clogging problem in comparison with PBD. In conclusion, PBD holds a superiority in waste lime's ground improvement and dewatering pore water pressure from the waste lime sludge. Also, circular drain is desired for some modification in its filtering system.