• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.365-372
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• 2007

Revisited in this paper are Green's functions for unit concentrated forces in an infinite orthotropic Kirchhoff plate. Instead of obtaining Green's functions expressed in explicit forms in terms of Barnett-Lothe tensors and their associated tensors in cylindrical or dual coordinates systems, presented here are Green's functions expressed in two quasi-harmonic functions in a Cartesian coordinates system. These functions could be applied to thin plate problems regardless of whether the plate is homogeneous or inhomogeneous in the thickness direction. With a composite variable defined as $z=x_1+ipx_2$ which is adopted under the necessity of expressing the Green's functions in terms of two quasi-harmonic functions in a Cartesian coordinates system Stroh-like formalism for orthotropic Kirchhoffplates is evolved. Using some identities of logarithmic and arctangent functions given in this paper, the Green's functions are presented in terms of two quasi-harmonic functions. These forms of Green's functions are favorable to obtain the Newtonian potentials associated with defect problems. Thus, the defects in the orthotropic plate may be easily analyzed by way of the Green's function method.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.758-762
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• 2008

As development of IT technology, Interest of Green building has been increasing rapidly. Because the construction industry is on the center of Green development, Green construction management is demanded for efficient analysis solution of building performance. BIM has a object-oriented parametric modeling technology. IT, which green building's performance management and analysis, is very useful. A green building certification is essential course in the green building construction. So this Paper suggest him based green building simulation system. The him based green building simulation system will support resonable decision making on the early construction phase.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.525-531
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• 2001

The present study investigated the protective effects of green tea against acute ethanol-induced lipid peroxidation and the change of antioxidative enzyme activities in various regions of rat brain : cortex, cerebellum, striatum and hippocampus. The following parameters were examined : malondialdehyde(MDA) levels and activities of superoxide dismutase(SOD), catalase and glutathione peroxidase(GSH-Px). Male Sprague-Dawley rats were given the experimental containing 1% green tea powder or control diet for 4 weeks, and at the end of feeding diet group received acute ethanol(5g/kg body weight) or equicaloric sucrose solution intragastrically. Green tea powder significantly decreased MDA levels in the striatum compared to control-non alcohol treated group to 1% green tea-non alcohol treated group without altering the antioxidative enzyme activities. Green tea resulted in a significant increase in GSH-Px activities in the hippocampus compared to either control-non alcohol treated group(0.043units/mg protein) or 1% green tea-non alcohol treated group(0.071units/mg protein). In conclusion, these results suggest that moderate consumption of green tea leaves can exert protective effects against ethanol-induced oxidative stress in brain regions, by reducing MDA concentrations in the striatum and enhancing GSH-Px activities in the hippocampus. (Korean J Nutrition 34(5) : 525∼531, 2001)

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.2
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• pp.83-90
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• 2010

The hydrodynamic interaction of two floating bodies in waves freely floating or connected by a rigid link is studied by using a boundary element method in the frequency-domain. The exact two-body hydrodynamic coefficients of added mass, wave damping and exciting force are calculated from the radiation-diffraction potential solution of the improved Green integral equation associated with the free surface Green function. The irregular frequencies in the conventional Green integral equation make it difficult to predict the physical resonance of the fluid in the gap between two bodies floating side by side. However, the improved Green integral equation employed in this study is free of irregular frequencies and always yields the exact solution of the multi-body radiation-diffraction potential boundary value problem. The 6 degree-of-freedom motions of two bodies freely floating side by side or connected parallel by a rigid link have been calculated for the incident wave frequencies ranging from 0.1 to 5 radians per second in head, left and right bow quartering seas. The 6-component load of the rigid link have also been presented.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.1
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• pp.17-33
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• 2023

Disasters in coastal regions are a constant source of damage due to their uncertainty and complexity, leading to the proposal of green infrastructure as a nature-based solution that incorporates the concept of resilience to address the limitations of traditional grey infrastructure. This study analyzed trends in research related to coastal disasters and green infrastructure by conducting a co-occurrence keyword analysis of 2,183 articles collected from the Web of Science (WoS). The analysis resulted in the classification of the literature into four clusters. Cluster 1 is related to coastal disasters and tsunamis, as well as predictive simulation techniques, and includes keywords such as surge, wave, tide, and modeling. Cluster 2 focuses on the social system damage caused by coastal disasters and theoretical concepts, with keywords such as population, community, and green infrastructure elements like habitat, wetland, salt marsh, coral reef, and mangrove. Cluster 3 deals with coastal disaster-related sea level rise and international issues, and includes keywords such as sea level rise (or change), floodplain, and DEM. Finally, cluster 4 covers coastal erosion and vulnerability, and GIS, with the theme of 'coastal vulnerability and spatial technique'. Keywords related to green infrastructure in cluster 2 have been continuously appearing since 2016, but their focus has been on the function and effect of each element. Based on this analysis, implications for planning and management processes using green infrastructure in response to coastal disasters have been derived. This study can serve as a valuable resource for future research and policy in responding to and managing various disasters in coastal regions.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.694-696
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• 2010

We have synthesized boron (or phosphorous) doped silicon nanoparticles (Si-NPs) by a solution process. The surfaces of the Si-NPs were terminated with various alkyl groups to form a protecting layer. The Si-NPs were characterized by UV-Vis, PL, FTIR, and NMR. Through a microwave sintering process, the crystalline thin films of the Si-NPs were prepared by removing the surface alkyl groups. The TEM and SEM images reveal that contiguous films as large as $200{\mu}m$ in diameter were formed with a cubic structure. The electrical conductivity of the Si film was controlled by a doping type.

• Membrane Journal
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• v.30 no.4
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• pp.276-281
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• 2020

A research was conducted on the removal of ion from the solution involving the alkali metal ion and chlorine ion using ion exchange resin. The cation exchange resin and anion exchange resin was used for the remove of metal ion (Na⁺ and K⁺) and chlorine ion (Cl^-), respectively. In the case of solution A (involving 36,633 ppm of Na⁺ and 57,921 ppm of Cl^-), the Na⁺ ion and Cl^- ion were removed over 99% within 20 min. In the case of solution B (involving 1,638 ppm of K⁺), the K⁺ ion was removed over 99% within 3 min.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.328-335
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• 2018

'EGCG(epigallocatechin gallate) rich Green Tea extract(EGTE)' was prepared by a convenient chromatographical manner using water and alcohol which was regarded as the most suitable and appropriate process for food manufacturing. The EGCG content in EGTE was estimated above 97%. Analysis of polyphenol components in green tea, i.e., catechin(C), epigallocatechin(EGC), epicatechin(EC), epigallocatechin gallate(EGCG), epicatechin gallate(ECG) and caffeine was performed by HPLC. The optimized HPLC method exhibited a good linearity of calibration curve, accuracy and precision. The long-term stability evaluation of EGTE was carried out with a powdered formulation and solution formulation by estimating the color change and measuring the EGCG content by HPLC analysis for one year. The EGCG content of the powdered EGTE stored in a transparent bottle at room temperature was retained over 97% at the end of the experimental period. The EGCG content of 0.1% water solution of EGTE stored in a transparent bottle at RT were observed to decrease below 30%, whereas that stored at $2^{\circ}C$ retained over 70%, respectively. These results suggested that a powdered formulation could be recommended for the commercialized nutraceutical product of EGTE rather than a solution formulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.682-687
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• 2018

We investigated the effects of a highly saline solution (HS) containing hypochlorous acid, calcium chloride ($CaCl_2$), and phosphoric acid ($H_3PO_4$) on cell death and growth rate of laver Porphyra yezoensis and green laver Ulva intestinalis. Cell death rates of laver treated with HS and HS plus hypochlorous acid (HS + HOCl) in the harvesting stage were less than 0.5%, and there were no significant differences between the HS and HS + HOCl treatments. However, cell death of green laver treated with HS + HOCl in the harvesting stage was greater than 81.2%. These results indicate that the addition of HOCl is highly effective to eradicate noxious green laver without causing damage to laver. The addition of HOCl and $H_3PO_4$ to HS did not increase the area or weight of laver blades. A combination treatment of $CaCl_2$ and HS, however, significantly increased the area and weight of laver lades compared to controls (P<0.05).

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.209-216
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• 2008

Super austenitic stainless steels shows the high PRE (Pitting Resistance Equivalent) number and the good corrosion resistance. This work controlled the Co contents in Fe-31Cr-1.7Mo-27Ni-0.25N alloys to elucidate the effect of cobalt contents on the biocompatibility and corrosion resistance. Increasing Co contents, the hardness of the annealed alloys tends to be reduced. In aged alloys, cobalt decreased the increments of hardness by aging treatment. Cobalt decreased the critical pitting temperature (CPT) in 6% $FeCl_3$ + 1% HCl solution, but improved the anodic polarization behavior in Hanks' balanced salt solution and artificial saliva solution. Repassivation rate in artificial body solutions was improved by increasing cobalt contents, but didn't show the linear relationship to PRE number of the alloys. The experimental alloys showed the non-cytotoxicity because of its high corrosion resistance.