• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.869-877
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• 2020

A 24-month Advanced Power Reactor 1400 (APR1400) core with a very-low-boron (VLB) concentration has been investigated for an inherently safe and high-performance PWR in this work. To develop a high-performance APR1400 which is able to do the passive frequency control operation, VLB feature is essential. In this paper, the centrally-shielded burnable absorber (CSBA) is utilized for an efficient VLB operation in the 24-month cycle APR1400 core. This innovative design of the VLB APR1400 core includes the optimization of burnable absorber and loading pattern as well as axial cutback for a 24-month cycle operation. In addition to CSBA, an Er-doped guide thimble is also introduced for partial management of the excess reactivity and local peaking factor. To improve the neutron economy of the core, two alternative radial reflectors are adopted in this study, which are SS-304 and ZrO₂. The core reactivity and power distributions for a 2-batch equilibrium cycle are analyzed and compared for each reflector design. Numerical results show that a VLB core can be successfully designed with 24-month cycle and the cycle length is improved significantly with the alternative reflectors. The neutronic analyses are performed using the Monte Carlo Serpent code and 3-D diffusion code COREDAX-2 with the ENDF/B-VII.1.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.81.2-81.2
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• 2012

To fabricate a metal mold for injection molding, hot-embossing and imprinting process, mechanical machining, electro discharge machining (EDM), electrochemical machining (ECM), laser process and wet etching ($FeCl_3$ process) have been widely used. However it is hard to get precise structure with these processes. Electrochemical etching has been also employed to fabricate a micro structure in metal mold. A through mask electrochemical micro machining (TMEMM) is one of the electrochemical etching processes which can obtain finely precise structure. In this process, many parameters such as current density, process time, temperature of electrolyte and distance between electrodes should be controlled. Therefore, it is difficult to predict the result because it has low reliability and reproducibility. To improve it, we investigated this process numerically and experimentally. To search the relation between processing parameters and the results, we used finite element simulation and the commercial finite element method (FEM) software ANSYS was used to analyze the electric field. In this study, it was supposed that the anodic dissolution process is predicted depending on the current density which is one of major parameters with finite element method. In experiment, we used stainless steel (SS304) substrate with various sized square and circular array patterns as an anode and copper (Cu) plate as a cathode. A mixture of $H_2SO_4$, $H_3PO_4$ and DIW was used as an electrolyte. After electrochemical etching process, we compared the results of experiment and simulation. As a result, we got the current distribution in the electrolyte and line profile of current density of the patterns from simulation. And etching profile and surface morphologies were characterized by 3D-profiler(${\mu}$-surf, Nanofocus, Germany) and FE-SEM(S-4800, Hitachi, Japan) measurement. From comparison of these data, it was confirmed that current distribution and line profile of the patterns from simulation are similar to surface morphology and etching profile of the sample from the process, respectively. Then we concluded that current density is more concentrated at the edge of pattern and the depth of etched area is proportional to current density.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.295-304
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• 2001

Characterization of quantitative trait loci (QTL) was investigated in the experimental crosses between Berkshire and Yorkshire breed. A total of 525 F$_2$ progenies from 65 matting of F$_1$ Parents were produced. Phenotypic measurements included average daily gain (ADG), average back fat thickness (ABF), and loin eye area (LEA). To identify the presence of QTL for reproductive performance, birth weight (BWT) and body weight at 16 days (16DAY) were included as indirect trait. QTL segregation was deduced using 8 markers assigned to chromosome 2 (SSC2). Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. Presence of imprinting was tested under the statistical model that separated the expression of paternally and maternally inherited alleles. To set the evidence of QTL presence, significance thresholds were derived by permutation following statistical tests, respectively. Genome scan revealed significant evidence for three quantitative trait loci (QTL) affecting growth and body compositions, of which two were identified to be QTL with imprinting expression mode near the ICF II gene region. For average back fat thickness (ABF), a paternally expressed QTL was found on chromosome 2 (SSC2). A paternally expressed QTL affecting loin eye area (LEA) was found in the region of SSC2 where evidence of imprinted QTL was found for average back fat thickness (ABF). For average daily gain (ADG), QTL expressed with Mendelian mode was found on chromosome 2 (SS2). Also, QTL affecting average daily gain (ADC), was identified to be expressed with Mendelian express mode.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.6
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• pp.455-463
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• 1998

RCCA(rod cluster control assembly) End-Tip suffers from neutron irradiation and constant vibration due to high-speed internal flow of primary coolant during plant operation. Such operating conditions cause the RCCA end-tip crackings around tile circumferential weldment of the end-tip, and in some cases, the defective end-tips were completly broken loose. However, no reliable inspection techniques for end-tip crackings were developed in the past, although some techniques exist for inspecting RCCA control rod wears. Therefore, NDE group at KEPRI has developed an ECT technique for the detection and the sizing of the end-tip crackings. The technique uses a specially designed surface-riding probe that can detect size of circumferential crackings with an accuracy of ${\pm}5.31%$ RMS error. This paper describes the ECT instrumentation including the ECT probes, calibration bars, as well as technical approaches.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.295-304
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• 2011

This study was carried out to investigate the effect of harvest stage of Sorghum ${\times}$ Sorghum Hybrid (SSH) and manufacture methods of SSH silage on nutritive values and quality of SSH silage manufactured with SSH grown in paddy land of Department of Animal Resources Development, National Institute of Animal Science, RDA. SSH "SS405" was harvested at two different growth stages (heading and ripen stage) and ensiled at each harvest stages. The content of crude protein in both square baled SSH silage (SBSS) and bag silage (BS) increased with delayed harvest maturity, but the contents of ADF (acid detergent fiber), NDF (neutral detergent fiber) decreased. The contents of ADF and NDF was not influenced by the inoculation of lactic bacteria. The contents of TDN (total digestible nutrient) in both stage and in vitro dry matter digestibility (IVDMD) in heading stage was not influenced by the harvest stage of SSH. The pH in all SSH silage ranged from 3.8 to 4.4 at two different harvest stages, and pH in heading stage was higher than that of ripen stage (P<0.05). The content of lactic acid of all SSH silage increased with delayed harvest maturity (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in ripen stage were not influenced by manufacture method of silage. The content of lactic acid in both SBSS was higher than that of both BS and RBSS in heading and ripen stage (P<0.05), but the content of acetic acid decreased (P<0.05). The contents of lactic acid and acetic acid in BS were similar as compared to that of RBSS. Therefore, we suggest that the quality of SSH silage in both heading and ripen stage can be improved by manufacture methods of SBSS and BS.

• Journal of Korean Philosophical Society
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• v.130
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• pp.277-304
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• 2014

Der vorliegende Beitrag zielt darauft ab, zwei Perspektiven $f{\ddot{u}}r$ die Kunst bei Kant und Nietzsche und ihre Schlussfolgerungen zu $er{\ddot{o}}rtern$. Kants Kritik der Urteilskraft hat eine enorme Rolle in der Geschichte der ${\ddot{A}}sthetik$ gespielt. $F{\ddot{u}}r$ Kant sollen ${\ddot{a}}sthetische$ Urteile ebenso wie Erkenntnis- und Moralurteile $allgemeing{\ddot{u}}ltig$ sein, obwohl sie auf einem $pers{\ddot{o}}nlichen$ Geschmack beruhen. Die $Allgemeing{\ddot{u}}ltigkeit$ des $Sch{\ddot{o}}nen$ sei $m{\ddot{o}}glich$, weil sie nicht auf dem Gegenstand, sondern auf dem transzendentalen Subjekt basiere. Die $sch{\ddot{o}}ne$ Kunst als Kunst des Genies soll uns wie die $Natursch{\ddot{o}}nheit$ ohne Interesse wohlgefallen. Nietzsches Stellungnahme zu Kants ${\ddot{A}}sthetik$ ist sehr kritisch. Nietzsches erster Kritikpunkt richtet sich gegen das 'interesselose Wohlgefallen'. Gegen Kant behauptet Nietzsche, dass die $Sch{\ddot{o}}nheit$ sehr wohl mit Interesse verbunden ist. Grund $daf{\ddot{u}}r$ ist, dass das $Sch{\ddot{o}}ne$ wesentlich aus dem Willen zur Macht entspringt. Der zweite Kritikpunk Nietzsches liegt darin, dass in Kants ${\ddot{A}}sthetik$ die Moral im Vordergrund steht. Das $Sch{\ddot{o}}ne$ ist $f{\ddot{u}}r$ Kant durch die Moral gerechtfertigt. Nietzsche dreht diese Stellung der Moral zur Kunst um. Der dritte Kritikpunkt Nietzsches ist, dass Kant statt von der Erfahrung des $K{\ddot{u}}nstlers$ (Schaffenden) aus das ${\ddot{a}}sthetische$ Problem zu betrachten, allein vom Zuschauer (Empfangenden) aus ${\ddot{u}}ber$ die Kunst und das $Sch{\ddot{o}}ne$ nachgedacht habe. $F{\ddot{u}}r$ Nietzsche ist die Kunst $prim{\ddot{a}}r$ vom $K{\ddot{u}}nstler$ aus zu verstehen. Nietzsches Physiologie der Kunst ist mit dem Begriff 'Leib' $verkn{\ddot{u}}pft$, d.h. Nietzsche behauptet, dass physiologische und ${\ddot{a}}sthetische$ Prozesse wesentlich $zusammenh{\ddot{a}}ngen$. Die Schlussfolgerung der Physiologie der Kunst lautet: erstens, jeder Mensch ist $K{\ddot{u}}nstler$, sofern er schaffend ist, und zweitens, die Welt selbst ist nichts als Kunst. Nietzsches Physiologie der Kunst hat einen $gro{\ss}en$ Einfluss auf die $gegenw{\ddot{a}}rtige$ Kunst $ausge{\ddot{u}}bt$ und kein anderer Philosoph hat auf die $gegenw{\ddot{a}}rtige$ Kunst nachaltiger gewirkt.