• Applied Microscopy
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• v.25 no.4
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• pp.115-123
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• 1995

This study was carried out to observe the functional ultrastructures of photoreceptor cells in frog(Rana catesbeiana) retina using transmission electron microscope. The photoreceptor cells are divided into two types-rod and cone cells-consist of outer and inner segment. The long outer segment of rod cell contains dense stacks of membrane and formed vertical and horizontal folds. The outer segment of cone cell is small, and vertical and horizontal folds are not exist. The electron dense cytoplasm of rod cell contains compact mitochondria, Golgi complexes, and endoplasmic reticula. The inner segment of cone cell shows low electron density and contains a large lipid droplet in the upper part of inner segment. In addition, cone cell contains many mitochondria, Golgi complexes. rough endoplasmic reticula, ribosomes and numerous glycogen particles. It is believed that these ultrastructural characteristics are closely associated with photoreceptive function of photoreceptor cells in frog retina.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.152-159
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• 2001

This paper presents a development of the recoil rod pull force measurement system suing the load cell with a sleeve normally available in the recoil system test. The commercial load cell cannot be used in the test of recoil system floating the breach contact point freely in the air. The load cell is designed and manufactured to meet the recoil system test condition. Theoretical analysis and experimental results show that the accuracy of the developed measurement system is within $\pm$0.5%. We notice that the measurement technique proposed in this paper is accurate and useful in the recoil rod pull force measurement of the recoil system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.141-144
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• 2006

In this study, we developed a decladding device which separates 250 mm length of simulated nuclear spent fuel rod into the pallets and the pieces of the hulls after inserting the rod cut into the module with several pairs of blades. To improve the performance of the equipment, we considered some mechanisms to prevent the rod cut from being exposed or bounced into the hot-cell, to reduce the operation time, and to insert the rods automatically. It is expected that the newly developed system will contribute to prevent radioactive pollution in the hot-cell, reduce the operation time, and to increase the safety of the operators. As a result of the performance test for some mockup fuel rod cuts in the ACP(Advanced Spent Fuel Control Process) facility, it was verified that the decladding device could be applied to the actual fuel rod cut. And it will be able to use for a scale-up facility in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.684-687
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• 2002

The authors have developed two devices which cuts the spend fuel rod to an optimal size and extracts fuel pellet from the pieces of cut fuel rods. These devices are so important to reduce radioactive wastes that some advanced countries developed their own methods and devices. The authors have benchmarked from these methods and devices. For spent fuel rod cutting, the tube cutting method has been chosen. some mechanical properties of the fuel tube and pellet has been carefully considered for an optimal cutting size. For fuel pellet extraction, a mechanically extracting method has been adopted. The existing chemical method have turned out to be inappropriate because it produced large amount of radioactive wastes, in spite of its high fuel recovery characteristics. The developed method has an advantage that it can be applied to other fuel rods that have different shapes and sizes. The two devices are set up and operated in the hot cell where people can not go in, so that the devices have been designed to be controlled remotely and modulated for easy maintenance. And the performance of the devices has been tested by using simulated fuel rod. From the experimental results, the devices are supposed to be useful for reducing radioactive wastes.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.175-180
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• 1997

It has been known that eater-side corrosion of fuel rods in nuclear reactor is accompanied with the metallic loss of wall thickness and hydrogen pickup in the fuel dadding tube. The fuel dad corrosion is one of the major factors to be controlled to maintain the fuel integrity during reactor operation. An oxide later thickness measuring device equipped with ECT probe system was developed by KAERI, and whose performance test was carried out in NDT(Non-destructive Test) hot-cell or PIE(Post Irradiation Examination) Facility. At first, the calibration/performance test was executed for the unirradiated standard specimen rod fabricated with several kinds of plastic thin films whose thickness ore predetermined, and the result of which showed a good precision within 10% of discrepancy. And then, hot test us peformed for the irradiated fuel rod selectively extracted from J44 fuel assembly discharged from Kori Unit-2. The data obtained with this device were compared with the metallographic result obtained from destructive examination in PIEF hot-cell on the same fuel rod to verify the validity of the measurement data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.651-654
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• 2001

In the dismantling process of nuclear spent fuels, the spent fuel rod cutting process, followed immediately by the decladding process, performs the cutting the spent fuel rods to a proper length for fast decladding operation. In this paper, we analyzed the chemical compositions, mechanical properties, and physical characteristics for SUS and zircaloy tubes in order to identify the feasibility of cutter-blade type in cutting SUS and zircaloy tubes. It is considered that material, shape and angle, and heat treatment for fabricating the highly durable cutter blade and also it is investigated that the round-shape sustenance of cross-section, amount of debris production, and fire occurrence for measuring the cutting performance on SUS and zircaloy tubes, spent fuel rod cutting device is designed to be operated automatically through the remote control system for use in Hot Cell(radioactive) area and the electro-driven mechanical parts are modularized for easy maintenance. Results from various experiments confirm the efficiency of this device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.459-460
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• 2008

Zinc oxide micro rods were fabricated using as chemical bath deposition ok photolithography. Vertically aligned Zinc Oxide rod array as grown by chemical bath deposition method on Zinc Oxide template layer. The ZnO template layer was deposited on glass and the pattering was made by standard photolithography technique. The selective growth of ZnO micro rods were achieved with the masked ZnO template layer substrate. The fabricated ZnO micro rods were found to be single crystalline and have grown along hexagonal c-axis direction of (0002) which is same as the preferred growth orientation of ZnO template layer. The ZnO micro-rod array structure was implemented as a window layer in Cu(InGa)Se2 solar cell and its effect on photovoltaic efficiency was examined.

• Applied Microscopy
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• v.50
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• pp.11.1-11.3
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• 2020

The human turbinate-derived mesenchymal stem cells (hTMSCs), which were DiI-labeled and transplanted into the subretinal space in degenerating mouse retina, were observed in retinal vertical sections processed for rhodopsin (a marker for rod photoreceptor) by confocal microscope with differential interference contrast (DIC) filters. The images clearly demonstrated that DiI-labeled hTMSCs have rhodopsin-immunoreactive appendages, indicating differentiation of transplanted hTMSC into rod photoreceptor. Conclusively, the finding suggests therapeutic potential of hTMSCs in retinal degeneration.

• Applied Microscopy
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• v.47 no.4
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• pp.238-241
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• 2017

A study on the visual cell and eyeball of the endemic Korean species Liobagrus mediadiposalis was investigated by light and electron microscopes. The retina of a small and 2 mm-diameter round eye was thin, $151.0{\pm}4.0{\mu}m$ and has two visual cells, a single cone and a rod cell. The single cone cells are short and thick, $18.0{\pm}0.9{\mu}m$ in length and $5.1{\pm}0.7{\mu}m$ (n=30) in diameter, while the rod cells are longer and thinner, $54.8{\pm}2.9{\mu}m$ in length and $3.3{\pm}0.6{\mu}m$ in diameter. The cone cells are seen an irregular and random mosaic pattern, and the rod cells are also randomly situated at between cone cells. As a rare phenomenon, such structure is one of characteristics reflecting the eye of a nocturnal and bottom-dwelling freshwater fish. The ultrastructure of visual cells was observed with scanning and transmission electron microscopy, both cone and rod cells are divided into an inner segment with numerous mitochondria and an outer segment with stacks of membrane discs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.1055-1058
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• 2005

In the ACPF(Advanced spent nuclear fuel Conditioning Process Facility), the spent fuel pellets which are highly radioactive materials are separated with its clad and are fed into the next conditioning process. For this, at the other facility called PIEF(Post Irradiation Examination Facility) a spent fuel rod, 3.5 m long, is cut by 25 cm long which is suitable length fur the decladding process. These rod-cuts are packed into the capsule and are moved to the ACPF. Once the capsule is unloaded in the ACPF, the rod-cut is taken out one-by-one from the capsule and installed on the decladding device. In these processes, the crushed spent fuel pellet can be scattered inside the facilities and thus it contaminate the hot cell. In this paper, we developed the specially designed capsule which prevents the pellets scattering and remarkably reduces the leading and unloading time of the rod-cuts.