• Advances in nano research
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• v.1 no.3
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• pp.153-158
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• 2013

An approach to achieving of spatially homogeneous, ordered ensemble of semiconductor quantum rods in polymer film of polyvinyl butyral is reported. The CdSe/ZnS quantum rods are embedded to the polymer film. Obtained film is stretched up to four times to its initial length. A concentration of quantum rods in the samples is around $2{\times}10^{-5}$ M. The absorption spectra, obtained in the light with orthogonal polarization, confirm the occurrence of spatial ordering in a quantum rod ensemble. Anisotropy of the optical properties in the ordered quantum rod ensemble is examined. The presented method can be used as a low-cost solution for preparing the nanostructured materials with anisotropic properties and high concentration of nanocrystals.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.358-360
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• 2004

To reduce the earth resistance, earth electrode are installed horizontally or vertically in the earth. There are two kinds of vertical earth electrode methods, one is a deep-driven rod and another is slight-driven parallel rods. Bibliography have so far analyzed the earth resistance calcalation of a rod type electrode and parallel rods type for the multi-layered earth. Befor long, We are going to study earth resistance of deep-driven rod and slight-driven parallel rods in the multi-layered earth with reference to bibliography.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.133-139
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• 1980

In this experiment, etching was performed on the incisor enamel surfaces of 13 Albino rats, weighted about 130gm, with both 30% and 50% concentrations of the phosphoric, citric acids, and EDTA solution for 60 seconds. Immediately after extraction of the animal teeth, laboratory procedures for scanning electron microscopic observations were made and the author derived the following conclusions: 1. On the enamel surface treated with 30% and 50% phosphoric acids, all of the periphery, center of the enamel rods, and the enamel matrices were severely etched. 2. In the etched with 30% citric acid group, only the small part of the enamel rods were etched out. In case of 50% citric acid the periphery, center of enamel rods were partially or entirely etched, and the intermatrix spaces were widened. 3. In the 30% and 50% of the EDTA etched groups, the periphery of the enamel rods explicitely were etched, and the spaces between matrices were widened.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1858-1860
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• 2003

Ground rods as the discharge path are commonly installed to ensure the safety of human beings and facilities from the surge. Accordingly, proper grounding resistance are specified by the grounding types, and the specified resistance are also required to install the lightning protective facilities. it is needed to analyze the difference between these two resistance through the field test. Therefore, in this paper, the impulse response behavior of the ground rods is analyzed by constructing the test facilities and by testing the ground rods in multi-ground power distribution systems. The impulse responses were analyzed, in transient state, by testing the concrete poles as well since the grounding wires are installed in the concrete poles.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.219-224
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• 1987

A strain of Leptospira interrogans(UM-19) was isolated in 1984 from a patient with epidemic pulmonary hemorrhagic fever. The bacteria has been characterized morphologically by a polymorphism showing spiral forms, short and long rods in culture. In order to study the biological relatedness among these forms of the bacteria, the short rods were separated from others by means of continuous sucrose density gradient centrifugation, and cultured at various temperatures such as $10^{\circ}C$, $15^{\circ}C$, $30^{\circ}C$ and $37^{\circ}C$. It was revealed that cultivation or subcultivation of the short rods has resulted in morphological changes observed by darkfield examination, silver stain, and scanning electron microscope showing spiral forms as well as short and long rods.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.2
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• pp.79-84
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• 1999

An image processing technology was developed to measure the dimension of nuclear fuel rods and the diameter of nuclear fuel rods was measured by this method. It was confirmed that parameters such as camera-to-specimen distance. camera location, light intensity and light characteristic would affect dimension measurement of nuclear fuel rods. The percent relative error and percent standard deviation of measuring the diameter of nuclear fuel rods using image processing method were 4.88%, ${\pm}3.34%$ while the percent relative error and percent standard deviation using conventional method were 12.7%, ${\pm}9.72%$, respectively. The accuracy of diameter measurement of nuclear fuel rods using image processing method was about 3 times as high as that using conventional method.

• Bulletin of the Society of Naval Architects of Korea
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• v.6 no.1
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• pp.35-42
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• 1969

Penetrations of arc welding electrades are different by changing welding conditions, welding speed of travel and current, even though quite same ones. Changing status of penetration is studied by changing welding speed of travel keeping welding current constant, at first, and by changing welding current keeping welding speed of travel which was obtained prior experiment constant, afterward. The F-100 4mm $\phi$ rods, E4301 class, which covering substance is mainly ilmenite and a domestic representative product of this class electrode, are used for this experiment. The Marquette's No.130 5/32"(4mm)$\phi$ rods, E6011 class, and No. 140 5/32"(4mm)$\phi$, E6013 class, which were produced in the United Stated, are used to compare penetration with F-100 at same welding conditions. The covering substance of Marquette's No. 130 rods is mainly cellulose, and belong to deep penetration arc welding electrodes, the covering material of another rods is titania, and a kind f shallow penetration rods. The result of this study is as follow : penetration of F-100, domestic ilmentite covering electrade, E4301 class, is between E6011 and E6013 of the United States products. At the lower range of welding current, penetration is closer to E6013 than E6011, at the higher range, closer to E6011 than another; and the value of penetration ranges $1.65{\sim}2.70mm$ for 4mm$\phi$ rods in the adequate current range. The changing status of penetration is showed by following experimental formula. $P=KE_v^{-\frac{2}{5}}1^{\frac{3}{2}}$

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3260-3267
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• 2023

Zr-Nb alloy have been widely used as fuel rods in nuclear power plants. However, from the Fukushima nuclear accident, the weakness of the rod was revealed under harsh conditions, and research on the safety of these types of rods was conducted after the disaster. The method of depositing chromium onto the existing Zr-Nb alloy fuel rods is being considered as a means by which to compensate for the weakness of Zr-Nb alloy rods because chromium is strong against oxidation at high temperatures and has high strength. In order to secure these advantages, it is important to maintain the Cr thickness of the rods and properly inspect the rods before and during their use in power generation. Eddy current testing is a typical means of evaluating the thickness of thin metals and detecting surface defects. Depending on the size and shape of the inspected object, various eddy current sensors can be applied. In particular, because pancake sensors can be manufactured in very small sizes, they can be used for inspections even in narrow spaces, such as a nuclear fuel assembly. In this study, an eddy current technique was developed to confirm the feasibility of Cr coating thickness evaluations. After determining the design parameters of the pancake sensor by means of a FEM simulation, a FPCB pancake sensor was manufactured and the optimal frequency was selected by measuring minute changes in the Cr-coating thickness using the developed sensor.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.825-836
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• 2010

The advancement of electronic records brought great changes of the records management system. One of the biggest changes is the transition from passive to automatic management system, which manages massive records more efficiently. The integrated Rule-Oriented Data System (iRODS) is a rule-oriented grid system S/W which provides an infrastructure for building massive archive through virtualization. It also allows to define rules for data distribution and back-up. Therefore, iRODS is an ideal tool to build an electronic record management system that manages electronic records automatically. In this paper we describe the issues related to design and implementation of the electronic record management system using iRODS. We also propose a system that serves automatic processing of distribution and back-up of records according to their types by defining iRODS rules. It also provides functions to store and retrieve metadata using iRODS Catalog (iCAT) Database.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.2
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• pp.121-128
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• 1996

The optimum conditons were experimentally established for the powder synthesis and sintering of the feed-rods for $LiNbO_3$ crystal growth by a floating zone method. At the lower synthesis temperatures(700, $ 800^{\circ}C$) the minor amounts of $Li_2CO_3$ and $Nb_2O_5$ were present in the synthesized $LiNbO_3$ powder and at the higher temperature the particle size increased which is not favorable for the sintering process for the feed-rods. $LiNbO_3$ powder synthesized at $950^{\circ}C$ for 12 hours was found to be the best because it contains only the$LiNbO_3$ phase with the small particle size and uniform particle size distribution. As the sintering temperature and the soaking time increase, the sintered feed-rods exhibited the higher sintered density and grain growth phenomena. The $LiNbO_3$ feed rods sintering at $1100^{\circ}C$ for 2 hours were found to have the best microstructure for the precursor feed-rods of the floating zone crystal growth because of their higher density, small grain size and uniform particle size distribution. As the sintering temperature and the soaking time increase, the sintered feed-rods exhibited the higher sintered density and grain growth phenomena. The $LiNbO_3$ feed rods sintering at $1100^{\circ}C$ for 2 hours were found to have the best microstructure for the precursor feed-rods of the floating zone crystal growth because of their density, small grain size and uniform grain size distribution.