• Nuclear Engineering and Technology
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• v.50 no.2
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• pp.297-305
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• 2018

Fuel assembly (FA) bow in pressurized water reactor (PWR) cores is considered to be a complex process with a large number of influencing mechanisms and several unknowns. Uncertainty and sensitivity analyses are a common way to assess the predictability of such complex phenomena. To perform such analyses, a structural model of a row of 15 FAs in the reactor core is implemented with the finite-element code ANSYS Mechanical APDL. The distribution of lateral hydraulic forces within the core row is estimated based on a two-dimensional Computational Fluid Dynamics model with porous media, assuming symmetric or asymmetric core inlet and outlet flow profiles. The influence of the creep rate on the bow amplitude is tested based on different creep models for guide tubes and fuel rods. Different FA initial states are considered: fresh FAs or FAs with higher burnup, which may be initially straight or exhibit an initial bow from previous cycles. The simulation results over one reactor cycle demonstrate that changes in the creep rate and the hydraulic conditions may have a considerable impact on the bow amplitudes and the bow patterns. A good knowledge of the specific creep behavior and the hydraulic conditions is therefore crucial for making reliable predictions.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.51-55
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• 1997

Three soils, sandy loam, loam and silty clay loam, were selected and three inches soil cores with 4 bulk density(BD) levels were made by compressing the soils wetted with 3 levels water. Mechanical and water characteristics were measured and analyzed the mechanical resistance limiting water, available water and least-limiting water range. Mechanical resistance limiting water(MRLW) were appeared at higher bulk density than $1.6Mg/m^3$ in sandy loam, and $1.4Mg/m^3$ in loam and silty clay loam. The least-limiting water ranges were sharply decreased at the bulk density $1.6Mg/m^3$ in sandy loam and loam, $1.4Mg/m^3$ in silty clay loam. There were big deferences between available water contents and least limiting water ranges in finer texture and higher bulk density soils.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1099-1103
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• 2011

Since the mechanical strength and stiffness of wire-woven bulk Kagome (BK) have been theoretically estimated by assuming that WBK is composed of straight struts, the analytical solutions occasionally give substantial errors as compared with the experimental results. The struts of WBK are helically formed, which results in errors in the estimations In this study, for accurately predicting the mechanical properties of WBK, the effects of waviness and brazed part are taken into account for estimating the strength and stiffness of WBK. The results are compared with the measured experimental results and the results estimated by a finite element analysis performed on a unit cell under periodic boundary conditions (PBC).

• Journal of the korean society of oceanography
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• v.31 no.2
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• pp.43-54
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• 1996

Jinhae Bay, one of the largest tidal bays on the southern coast of Korea, is an area with thick accumulations of recent, fine-grained sediments, mainly supplied from the Nakdong River. The preponderance of silt and clay particles reflects the large quantity of sediments transported in suspension. Although the clay mineral assemblage is similar to that derived from the nearby Nakdong River, relatively high concentration (3-9%) of smectite suggests some local input of fine particles from several streams around the bay or some contribution from the offshore water that may be influenced by the Tsushima Current. The content of organic matters in sediments is as high as 12%, and their C/N ratios imply that they are comprised of mixtures derived from marine plankton and terrestrial plants. $^{210}Pb$ excess activity profiles of sediment cores yield an average sedimentation rate (a 100-year time scale) of about 2-5 mm/yr, which coincides well with the long-term sedimentation rate (a 1000-year time scale) estimated from the sediment isopach map. On the basis of sediment bulk density and sedimentation rate, an annual sink of mud in the bay is estimated approximately 1.0 ${\times}$ $10^{6}$ tons per year.

• Journal of the Korean Society of Food Culture
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• v.11 no.5
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• pp.683-687
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• 1996

Jujube paste was prepared by autoclaving the fresh jujube at 1.2 atm and $120^{\circ}C$ for 30 min and removing the skin and cores. In order to increase the juice yield, the paste was treated with pectinase, cellulase and their combinations. The soluble fractions of enzymatically treated jujube paste were characterized in terms of yield, pH, titratable acidity, color, Bx, transmittance and sugar compositions. The original paste exhibited the water soluble fraction of 57.3%. Of various quality factors, the clarity was the most significantly distinguished between pectinase and cellulase treatments. The cellulase treatment produced the cloudy juice with the yield of 83.60%. On the other hand, the clear juice was produced by the pectinase and combined treatments due to degradation of pectins, whose yields were 79.47% and 85.39%, respectively. The results clearly demonstrated that the pectinase treatments improved the solubilization efficiency and clarity.

• Steel and Composite Structures
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• v.19 no.2
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• pp.293-308
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• 2015

Interaction between the external thin-walled steel tube and the internal concrete core significantly increases the bending resistance of composite beams and beam-columns in comparison with the steel or concrete members. There is presented a developed method for design of hollow and solid concrete-filled steel tubular beams based on test data, which gives better agreement with test results than EC4 because its limitation to take an increase in strength of concrete caused by confinement contradicts the recommendation of 6.7.2(4) that full composite action up to failure may be assumed between steel and concrete components of the member. Good agreement between the results of carried out experimental, numerical and theoretical investigations allows recommending the proposed method to use in design practice.

• Journal of the Korea Safety Management & Science
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• v.14 no.4
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• pp.107-116
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• 2012

The issues raised so far in the development of safety-critical systems have centered on how effectively the safety requirements are met in systems design. The systems are becoming more complex due to the increasing demand on the functionality and performance. As such, the integration of both the systems design and systems safety processes becomes more important and at the same time quite difficult to carry out. In this paper, an approach to solving the problem is presented, which is based on an integrated data model. To do so, the data generated from the inputs and outputs of the systems design and systems safety processes are analyzed first. The results of analysis are used to extract common attributes among the data, thereby making it possible to define classes. The classes then become the cores of the interface data model through which the interaction between the two processes under study can be modeled and interpreted. The approach taken has also been applied in a design case to demonstrate its value. It is expected that the results of the study could play a role of the stepping stone in extending to the architecture development of the integrated process.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.118-126
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• 2004

The aqueous extract of European mistletoe (Viscum album, L.) has been used in cancer therapy. The purified mistletoe lectins, main components of mistletoe, have demonstrated cytotoxic and immune-system-stimulating activities. Korean mistletoe (Viscum album L. coloratum), a subspecies of European mistletoe, has also been reported to possess anticancer and immunological activities. A galactose- and N-acetyl-D-galactosamine-specific lectin (Viscum album L. coloratum agglutinin, VCA) with Mr 60 kDa was isolated from Korean mistletoe. Mistletoe preparations have been given subcutaneously due to the low stability of lectin in the gastrointestinal (GI) tract. In the present study, we investigated the possibility of alginate/chitosan microcapsules as a tool for oral delivery of mistletoe lectin. In addition, our strategy has been to develop a system composed of stabilizing cores (granules), which contain mistletoe lectin, extract or powder, coated by a biodegradable polymer wall. Our results indicated that successful incorporation of VCA into alginate/chitosan microcapsules has been achieved and that the alginate/chitosan microcapsule protected the VCA from degradation at acidic pH values. And coating the VCA with polyacrylic polymers, Eudragit, produced outstanding results with ideal release profiles and only minimal losses of cytotoxicity after manufacturing step. The granules prepared with extract or whole plant produced the best results due to the stability in the extract or whole plant during manufacturing process.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.878-888
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• 2020

This paper presents the validation of UNIST in-house Monte Carlo code MCS used for the high-fidelity simulation of commercial pressurized water reactors (PWRs). Its focus is on the accurate, spatially detailed neutronic analyses of startup physics tests for the initial core of the Watts Bar Nuclear 1 reactor, which is a vital step in evaluating core phenomena in an operating nuclear power reactor. The MCS solutions for the Consortium for Advanced Simulation of Light Water Reactors (CASL) Virtual Environment for Reactor Applications (VERA) core physics benchmark progression problems 1 to 5 were verified with KENO-VI and Serpent 2 solutions for geometries ranging from a single-pin cell to a full core. MCS was also validated by comparing with results of reactor zero-power physics tests in a full-core simulation. MCS exhibits an excellent consistency against the measured data with a bias of ±3 pcm at the initial criticality whole-core problem. Furthermore, MCS solutions for rod worth are consistent with measured data, and reasonable agreement is obtained for the isothermal temperature coefficient and soluble boron worth. This favorable comparison with measured parameters exhibited by MCS continues to broaden its validation basis. These results provide confidence in MCS's capability in high-fidelity calculations for practical PWR cores.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.5
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• pp.537-546
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• 2021

Remanufacturing is one of the most important resource recycling technology in response to resource depletion and environmental pollution. Domestic remanufacturing industry don't invigorate compared to other advanced countries because of low price and reliability of remanufactured product. In this study, remanufactured hydraulic pump and solenoid valve were evaluated durability by accelerated life test. In order that standard remanufacturing process was developed by core analysis and failure mode and effect analysis. And cores were remanufactured by standard remanufacturing process. For accelerated life test, the evaluation item and criteria were deduced by results of FMEA, reliability standards and enterprise interior criteria. To evaluate durability of remanufactured product, the remanufactured hydraulic pump and solenoid valve were evaluated performance after accelerated life test and the results were satisfied with criteria. This study showed that remanufactured products have a similar level of durability to new products by definition of remanufacturing.