• ETRI Journal
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• v.29 no.6
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• pp.814-816
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• 2007

Conventional lithography methods of gold patterning are based on deposition and lift-off or deposition and etching. In this letter, we demonstrate a novel method of gold patterning using spin-coatable gold electron-beam resist which is functionalized gold nanocrystals with amine ligands. Amine-stabilized gold electron beam resist exhibits good sensitivity, 3.0 mC/$cm^2$, compared to that of thiol-stabilized gold electron beam resists. The proposed method reduces the number of processing steps and provides greater freedom in the patterning of complex nanostructures.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.241-242
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• 2009

Characterics of carrier-envelope-offset frequency ($f_{ceo}$) of a femtosecond laser stabilized by the direct locking method were investigated using two f-to-2f interferometers. The stability of $f_{ceo}$ was comaparable to that achieved with a conventional PLL method.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10a
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• pp.337-344
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• 2001

The application of mechanically stabilized earth wall(MSEW) with segmental front panel has been increasing in highway construction due to its cost-effectiveness. However, some failures during construction have been reported and many field engineers are reluctant to select this method for important structure. One of the main reasons may be that there is no moderate specification for design and construction of MSEW yet. This paper discussed the main results of analysis on a case of block-type segmental retaining wall in highway construction. Based on the results, some recommendations on design and construction method of MSEW are presented.

• 한국전산유체공학회:학술대회논문집
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• 1999.05a
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• pp.98-105
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• 1999

The Pressure-based Unstructured-grid Navier-Stokes Solver PUNS-2/3D for incompressible steady and unsteady viscous flows has been developed. It is based on nonstaggered cell-centered finite volume method. Second-order upwind scheme with least-square reconstruction is used for convective fluxes. The SIMPLE method is implemented to couple the pressure and velocity fields. And the time derivatives in the momentum equations are discretised using a second-order Euler backward-differencing scheme. The discretised linear equations are solved by the preconditioned Biconjugate Gradient Stabilized method(Bi-CGSTAB). The developed solver is applied to validation problems using hybrid meshes.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.457-462
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• 2022

This study is about the case applied of a shallow foundation reinforcement method for a low/mid-rise building where a relatively small load is applied by using a soil stabilized material that utilizes recycled resources. First, laboratory mixing test was conducted for four mixing ratios in order to derive the optimal mixing ratio in the field. Using the derived optimal mixing ratio, it was applied as a shallow foundation for the building in the field. The field application method used a simple process of compaction by the soil mixedure with the original soil and the soil stabilized material in the field. After field application, a plate bearing test was performed on one original ground and two improved ground to confirm the allowable bearing capacity. As a result of checking the bearing capacity, it was found that sufficient bearing capacity was exhibited.Therefore, it was confirmed that it can be used as a shallow foundation for the building.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.229-237
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• 2009

A conventional way of backfilling has used sand or in-situ soil. It not only requires substantial amount of time and cost but also makes it particularly difficult to fill the bottom part and small cracks of a pipe. To address the problem with the conventional method of compaction, liquefied stabilized soil was proposed as an alternative because it reuses in-situ soil which can ensure sand supply while adjusting flowability and strength of the soil with design of mix proportion. With an aim to identify the mixing properties of liquefied stabilized soil depending on the organic content of in-situ soil, this study conducted indoor tests of material segregation, flowability, strength, and permeability by changing humic acid content of the soil. The results revealed that material segregation and flowability increased proportionally while strength decreased with the increased amount of humic acid. In the mean time, permeability of liquefied stabilized soil wasn't affected by organic content.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.43-46
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• 2005

Micro molding technology is a promising mass production technology for polymer based microstructures. Mass production technologies such as the micro injection/compression molding, hot embossing, and micro reaction molding are already in use. In the present study, we have developed a numerical analysis system to simulate three-dimensional non-isothermal cavity filling for hot embossing, with a special emphasis on the free surface capturing. Precise free surface capturing has been successfully accomplished with the level set method, which is solved by means of the Runge-Kutta discontinuous Galerkin (RKDG) method. The RKDG method turns out to be excellent from the viewpoint of both numerical stability and accuracy of volume conservation. The Stokes equations are solved by the stabilized finite element method using the equal order tri-linear interpolation function. To prevent possible numerical oscillation in temperature Held we employ the streamline upwind Petrov-Galerkin (SUPG) method. With the developed code we investigated the detailed change of free surface shape in time during the mold filling. In the filling simulation of a simple rectangular cavity with repeating protruded parts, we find out that filling patterns are significantly influenced by the geometric characteristics such as the thickness of base plate and the aspect ratio and pitch of repeating microstructures. The numerical analysis system enables us to understand the basic flow and material deformation taking place during the cavity filling stage in microstructure fabrications.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.53-59
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• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• Journal of the Korean Ceramic Society
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• v.53 no.5
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• pp.529-534
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• 2016

Nanocrystalline powder of zirconia stabilized with 8 mol% yttria (YSZ) has been synthesized through oxalate process using $ZrOCl_2{\cdot}8H_2O$ and $Y(NO_3)_3{\cdot}6H_2O$ as starting materials. Understanding of the characteristic changes of YSZ powder as a function of processing conditions is crucial in developing dense and porous microstructures required for fuel cell applications. In this research, microstructure change, surface area, particle shape and particle size were measured as a function of different processing conditions such as calcination temperature, stirring speed and concentration of starting materials. The resultant crystallite sizes were calculated by XRD-LB (X-Ray Diffraction Line-Broadening) method, BET method, and morphology of the crystal was observed in TEM and FE-SEM. The TEM examination showed that the powder synthesized with 0.7 M of YSZ concentration had a spherical morphology with sizes ranging from 20 to 40 nm. However, the powder was gradually aggregated above 1.0 M of YSZ concentration with the aggregation being intensified as the YSZ concentration was increased.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.10-17
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• 2024

In Korea, the common remedial process for reclamation of agricultural soils nearby abandoned mines involves chemical soil stabilization followed by covering with clean soil. This study investigated the chemical properties of cover soils and the validity of HCl extraction method in assessing the degree of As and heavy metal stabilization in stabilized soils collected from 14 plots where mine reclamation had been completed. The results revealed there were no major differences in contaminants extraction rate between the stabilized soils and contaminated soils, suggesting HCl extraction procedure is a less feasible method to determine the efficiency of the stabilization. Soil quality indicators including OM, SiO₂, P₂O₅, etc. of the land-covering soils were generally lower than those of stabilized soils that used to be the cultivation layer before the stabilization. Nonetheless, the value of those indicators didn't meet the regulatry limits of agricultural soil. Therefore, future strategy for mine reclamation should concentrate not only on contaminant concentration but also on soil quality parameters for agricultural use of the reclaimed soil.