• 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.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.99-104
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• 2006

The Langmuir-Blodgett(LB) technique has attracted considerable interest in the fabrication of electrical and electronic devices. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed u and the molecular area Am. Compression speed a was about 30, 40, 50mm/min. Langmuir-Blodgett(LB)layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 9$\sim$21. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Journal of the Korean institute of surface engineering
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• v.46 no.4
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• pp.168-174
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• 2013

In this study, low-cost, high-speed deposition, excellent processability, high mechanical strength and electrical conductivity, chemical stability and corrosion resistance of stainless steel to meet the obsessive-compulsive (0.1 mm or less) were selected CrN thin film. new price reduction to sputter deposition causes - the possibility of sublimation source for inductively coupled plasma Cr rods were attempts by DC bias. 0.6 Pa Ar inductively coupled plasmas of 2.4 MHz, 500 W, keeping Cr Rod DC bias power 30 W (900 V, 0.02 A) is applied, $N_2$ flow rate of 0.5, 1.0, 1.5 sccm by varying the characteristics of were analyzed. $N_2$ flow rate increases, decreases and $Cr_2N$, CrN was found to increase. In addition to corrosion resistance and contact resistance, corrosion resistance, electrical conductivity was evaluated. corrosion current density than $N_2$ 0 sccm was sure to rise in all, $N_2$ 1 sccm at $4.390{\times}10^{-7}$ (at 0.6 V) $A{\cdot}cm^{-2}$, respectively. electrical conductivity process results when $N_2$ 1 sccm 28.8 $m{\Omega}/cm^2$ with the lowest value of the contact resistance was confirmed that came out. The OES (SQ-2000) and QMS (CPM-300) using a reactive deposition process to add $N_2$ to maintain a uniform deposition rate was confirmed that.

• Journal of Photoscience
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• v.9 no.2
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• pp.284-286
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• 2002

The inverted retina of the Onchidium dorsal eye (DE) is composed only of ciliary-type photoreceptor cells (CC's). The outer segment (OS) of the CC is a concentric lamellar structure consisting of many modified ciliary membranes and stains positively with anti-$\beta$-tubulin antibody. Near the base of the OS there are about 30 basal bodies each connecting individually to a cilium. The cilia are rod-shaped at the base, progressing upwards to a flattened sheet-like shape with increasing surface area. Three-dimensional analysis on serial sections demonstrates the ladle-shape of a modified cilium. Many modified cilia wrap around each other like the leaves of a cabbage. Nine pairs of microtubules (MT's) are located regularly in a ring at the base of the cilium, gradually losing their regular arrangement towards the periphery, where they separate into two subgroups that are contained within two swollen portions of a modified cilium. Within the CC of the Onchidium DE, MT's in the modified cilium exist as two poles extending longitudinally in a thin expanded ciliary membrane. This arrangement may support the photoreceptive OS and serve to maintain its structural integrity.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.398-402
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• 2012

ZnSe/$SiO_2$ coaxial nanowires were synthesized by a two-step process: thermal evaporation of ZnSe powders and sputter-deposition of $SiO_2$. Two different types of nanowires are observed: thin rod-like ones with a few to a few tens of nanometers in diameter and up to a few hundred of micrometers in length and wide belt-like ones with a few micrometers in width. Room-temperature photoluminescence (PL) measurement showed that ZnSe/$SiO_2$ coaxial nanowires had an orange emission band centered at approximately 610 nm. The intensity of the orange emission from the $SiO_2$-sheathed ZnSe nanowires was enhanced significantly by annealing in a reducing atmosphere whereas it was degraded by annealing in an oxidizing atmosphere. The origins of the PL changes by annealing are discussed based on the energy-dispersive X-ray spectroscopy analysis results.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.383-390
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• 2005

Effect of applying a DC voltage on the interfacial reaction at the metal to zirconia interface was investigated utilizing an oxygen ionic conductivity of partially stabilized zirconia. The joining of copper rod and zirconia tube was carried out in Ar gas atmosphere at $1000^{\circ}C$. There are two type of the joining. The one is the reaction bond consisting of copper and zirconia was dominated by surface reaction with a undetectable very thin layer. It was found that copper elements were diffused to zirconia side, but that Zr ions were not diffused to copper side. These results mean application of a DC voltage to migrate oxygen to the copper-zirconia interface can oxidize metal at the copper-zirconia interface and the bonding reaction between zirconia and copper oxide may occur. The other is the reaction bonding was dominated by interdiffusion with a very thick interface layer. This result mean application of a DC voltage can reduce zirconia at the interface. The bonding reaction is to be an alloying between Zr and Cu.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.87-98
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• 1999

This study is concentrated on the development of real-time estimation model and vision control method as well as the experimental test. The proposed method permits a kind of adaptability not otherwise available in that the relationship between the camera-space location of manipulable visual cues and the vector of manipulator joint coordinates is estimate in real time. This is done based on a estimation model ta\hat generalizes known manipulator kinematics to accommodate unknown relative camera position and orientation as well as uncertainty of manipulator. This vision control method is roboust and reliable, which overcomes the difficulties of the conventional research such as precise calibration of the vision sensor, exact kinematic modeling of the manipulator, and correct knowledge of position and orientation of CCD camera with respect to the manipulator base. Finally, evidence of the ability of real-time vision control method for manipulator's position control is provided by performing the thin-rod placement in space with 2 cues test model which is completed without a prior knowledge of camera or manipulator positions. This feature opens the door to a range of applications of manipulation, including a mobile manipulator with stationary cameras tracking and providing information for control of the manipulator event.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.90-92
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• 2010

Staining profiles and bacterial morphology were compared in Xanthomonas citri pv. citri by a transmission electron microscopy. Four types of negative staining regimes were employed depending on culture media and heavy metal stains. The bacterial cells grown on LB agar media often appeared clustered on the supporting film. Meanwhile, individual bacterial cells could be readily found on the preparations from LB broth media. Typical rod-shaped cells (ca. $1\;{\mu}m$ in length) and their flagella were observed in either 2% uranyl acetate (UA) or 2% neutralized potassium phosphotungstate (PTA) staining. The UA-stained bacteria often showed relatively intact cell morphology and rather positively stained cells with a thin electron-dense stain depth around bacteria. The PTA-stained bacteria were characterized by the wrinkled cell surface where the stain was entrapped in grooves. In addition, distinct electron-dense stain depth was evident around the PTA-stained preparations. Numerous fimbriae could be mostly observed from the PTA-stained preparations of the two culture media, but not from the UA-stained preparations.

• Journal of Powder Materials
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• v.2 no.2
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• pp.135-141
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• 1995

As the first step of study on fabrication of ceramic powders from phytoliths in rice, especially in rice husks, pulverization method of rice husks and the properties of milled rice husks were investigated. Impact methods, such as ball milling, were not meaningful for pulverizing elastic and thin fabric structure of rice husks. The most effective one was cutting method. In the present work, a rotating knife cutting method was applied to pulverizing rice husks. A 40-mesh screen was inserted under the rotating knives. The most portion of the milled powder was found in -50/+100 mesh section. Morphology of the milled rice husks revealed that the husks larger than 70 mesh were flake-like shape, at -70/+100 mesh section relatively equi-axed shape, at -170/+325 mesh section rod-like shape, and below 325 mesh section dust-like shape. Tap density of raw rice husks was about 0.1 $g/cm^3$, while those of milled rice husks were over $0.4 g/cm^3$. This meant that, for a given volume of reactor, raw material charge can be increased more that 4 times when using milled rice husks than unmilled one. True densities of unmilled and milled rice husks were higher than $1.4 g/cm^3$, and increased with decreasing milled sizes.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.24-27
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• 2001

The barbel structure of the spined loach Iksookimia longicorpa were investigated histologically. Their barbels consist of epidermis, dermis, and a central rod. The epidermis contains mucous cells, terminal buds, granular cells, and epidermal cells. The mucous cells are thin rims of basophilic cytoplasm and are located at the surface of the epidermis. The terminal bud is basophilic and is situated at the distal portion of the epidermis. The dermis consists of loose connective tissue containing blood vessels, pigment cells, and nerve cells. The central region of cartilage is the innermost region and is enclosed within muscle layers.