• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.514-517
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• 2008

Water gas shift(WGS) is an important step in fuel process for fuel cells, and improperness of commercial WGS catalysts for use in fuel cell systems has prompted numerous researches on noble metal catalysts. A selected noble metal catalyst for water gas shift reaction(WGS) was prepared with various metal loadings. The prepared catalysts were tested under two feeding conditions. At moderate residence time, carbon monoxide conversion was much higher on the noble metal catalysts as compared to commercial high-temperature shift catalyst. Effects of metal loading were examined by activity tests at short residence time. Higher metal loading effected higher reaction rate. The kinetic data was fitted to simple reaction equations and effectiveness factor was estimated. The results suggest the necessity of a structural design for the highly active noble metal catalysts.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.560-563
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• 2008

A modified polyol process is developed to enhance Pt loading during the preparation of Pt/C catalysts. With the help of the zeta potential, the effect of pH on the electrostatic forces between the support and the Pt colloid is investigated. It is shown experimentally that the surface charge on the carbon support becomes more electropositive when the solution pH is changed from alkaline to acidic. However, this change does not affect the electronegative surface charge of Pt colloids already attained and stabilized by glycolate anions. This new behavior caused by the change in the solution pH accounts for the enhanced yield of the process and does not affect the Pt particle size. All our experimental results reveal that this simple modification is a cost effective method for the synthesis of highly Pt loaded Pt/C catalysts for fuel cells.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.77-82
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• 1997

The CANDU-6 transition core refuelled from 37-element fuel to CANFLEX-NU fuel has been evaluated by an 100full power day time-dependent fuel-management simulation to find the core compatibility with the CANFLEX fuel loading. The simulation calculations for the transition core were carried out with the RFSP code, provided by the cell averaged fuel properties obtained from the POWDERPUFS-V code. The simulation results were compared with those of the current 37-element fuel loading only. The results show that the CANFLEX-NU fuel bundles will be compatible with the CANDU-6 reactor because the core physics characteristics of CANFLEX-NU fuel are very similar to those of the 37-element fuel bundle.

• Journal of Mechanical Science and Technology
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• 제16권5호
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• pp.655-665
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• 2002

Two-dimensional elastic analysis of doubly periodic circular holes in an infinite plane is given in this paper. Two cases of loading, remote tension and remote shear, are considered. A rectangular cell is cut from the infinite plane. In both cases, the boundary value problem can be reduced to a complex mixed one. It is found that the eigenfunction expansion variational method is efficient to solve the problem. Based on the deformation response under certain loading, the notched medium could be modeled by an orthotropic medium without holes. Elastic properties for the equivalent orthotropic medium are investigated, and the stress concentration along the hole contour is studied. Finally, numerical examples and results are given.

• 한국지반공학회지:지반
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• 제12권5호
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• pp.55-62
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• 1996

Lateral loading model tests were performed on the rigid box-shaped cellular bulkhead by displacement-controlled method. The materials of ground and fill used in this study are two aluminium rods with different sections. The behalf·iotas of ground and fill were recorded by photo/video techniques and failure mechanism created in ground and fill has been simulated two-야mensionally. Also the theoretical consideration about the test results was done on the basis of Hansen's earth pressure theory. As a result, the shape of sliding face the location of sliding face and the loading height was also investigated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.865-870
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• 2001

A sensing element for tri-axial force measurement, unit sensor of tactile sensor, was designed and evaluated by using finite element method (ANSYS). The sensor has a maximum force range of ${\pm}10$ N in the x, y, and z direction. Optimal cell structures and piezoresistor positions were determined by the strain distribution obtained from finite element analysis. Finally three Wheatstone birdge circuits were arranged and verified by $F_x$, $F_y$, and $F_z$ loading conditions. In addition, in case of sensing element subjected to thermal loading, the outputs of three bridge circuits were also evaluated.

• KSBB Journal
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• 제10권4호
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• pp.358-369
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• 1995

A mathematical model using local thermodynamic equilibrium isotherms for adsorption in encapsulated adsorbent is proposed in order to optimize the design parameters in situ bioproduct separation process. The model accurately follows the experimental data on the adsorption of berberine, secondary metabolite produced in Thaictrum rugosum plant cell culture. The adsorption rate on encapsulated adsorbent is compared with that on alginate-entrapped adsorbent. The result shows that the higher loading capacity in encapsulated adsorbent is mainly due to the increase in the maximum solid phase concentration. Based on the adsorption rate and loading capacity, the encapsulated adsorbent would be more useful than the entrapped adsorbent when used in situ bioproduct separation process. Design parameters in situ bioproduct separation process, such as the size of the capsule, membrane thickness, the ratio of capsule volume to bulk volume, the ratio of single capsule volume to total capsule volume and the adsorbent content in the capsule, are evaluated by using the model. The ratio of single capsule volume to total capsule volume is the most effective parameter for adsorption of berberine on encapsulated adsorbent.

• Geomechanics and Engineering
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• 제13권6호
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• pp.963-975
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• 2017

Improvement of soft clay deposit by preloading with vertical drains is one of the most popular techniques followed worldwide. These drains accelerate the rate of consolidation by shortening the drainage path. Although the analytical and numerical solutions available are mostly based on equal strain hypothesis, the adoption of free strain analysis is more realistic because of the flexible nature of the imposed surcharge loading, especially for the embankment loading used for transport infrastructure. In this paper, a numerical model has been developed based on free strain hypothesis for understanding the behaviour of soft ground improvement by vertical drain with preloading. The unit cell analogy is used and the effect of smear has been incorporated. The model has been validated by comparing with available field test results and thereafter, a hypothetical case study is done using the available field data for soft clay deposit existing in the eastern part of Australia and important conclusions are drawn therefrom.

• 한국해양공학회지
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• 제32권3호
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• pp.158-165
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• 2018

Generally, container ships contain cargo holds with cell guides that serve to increase the container loading and unloading efficiency, minimize the space loss, and fix containers during the voyage. This paper describes a new quality management system for the cell guides of container ships (the so-called Trim Cell Guide system). The main functions of this system are the trimming of the point cloud obtained using a 3D scanner and an inspection simulation for cell guide quality. In other words, the raw point cloud of cell guides after construction is measured using a 3D scanner. Here, the raw point cloud contains a lot of noise and unnecessary information. Using the GUI interface supported by the system, the raw point cloud can be trimmed. The trimmed point cloud is used in a simulation for cell guide quality inspection. The RANSAC (Random Sample Consensus) algorithm is used for the transverse section representation of a cell guide at a certain height and applied for the calculation of the intervals between the cell guides and container. When the container hits the cell guides during the inspection simulation, the container is rotated horizontally and checked again for a possible collision. It focuses on a system that can be simulated with the same inspection process as in a shipyard. For a practicality review, we compared the precision data gained from an inspection simulation with the measured data. As a result, it was confirmed that these values were within approximately ${\pm}2mm$.

• 한국물환경학회지
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• 제22권3호
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• pp.546-556
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• 2006

The purpose of this study is to improve the polluted stream water quality by pilot-scale five different constructed wetlands (CWs). Cell 1 to 3 are newly designed 2SFCW (Surface-subsurface flow CW) with 1 to 3 flow shifters (FS) in the middle of the wetland system. Cell 4 and 5 are control CW (CCW), but Cell 5 is the same type as Cell 3. The FS, which converts the route of surface and subsurface flow between two wetlands connected in series, was able to enhance the treatability of TN via nitrification and denitrification and of SS due to filtration and sedimentation. The void fraction and dispersion number of Cell 1, 2 and 3 obtained from the RTD analysis were found to be 0.73 and 0.17, respectively. COD and TP removal efficiencies of Cell 1 to 3 were similar to that of Cell 4 and 5. SS removal efficiencies of Cell 1 to 3 and 5 with FS were 5-10% higher than that of Cell 4 without FS. TN removal efficiencies of Cell 1 to 3 were 3-14% higher than that of Cell 4 and 5. The average $R^2$ values of COD, SS, TN and TP obtained from nonlinear regression analysis were similar to the results of other researchers.