• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.2
• /
• pp.63-67
• /
• 2004

The layered structure of cobalt dodecanesulfate was synthesized. A phase transition takes place at various temperature ranges and results in a drastic change of the layer distance. A monolayer structure of cobalt dodecanesulfate at room temperature transformed to a bilayer structure as a dehydrated form at high temperature.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.173.2-173.2
• /
• 2016

A two-step oxidation method was applied on Al6061 to debate the growth mechanism of plasma electrolytic oxidation (PEO) coating. The specimens were first oxidized in the primary electrolyte solution {$Na_3PO_4$ (8g/l), NaOH (2g/l), consequently, the specimens were transferred into a different electrolyte {$K_2ZrF_6$ (8g/l), NaOH (2g/l), $Na_2SiF_6$ (0.5g/l)} for further oxidation. The processes was conducted for various processing times. It was found the second step electrolyte component were reached to inner layers, in contrast to the primary step components which were thrustle to the outer layer. The presence of the secondary component in the inner layers were significantly varied with processing time which suggest the change in growth properties with processing time. further more the inside growth of the secondary component confirmed the increasing trend in the downward growth of the coating layer. The corrosion and hardness properties of the coatings were found highly improved with change in growth features with increasing the processing time.

• Journal of the Korean Vacuum Society
• /
• v.5 no.3
• /
• pp.199-205
• /
• 1996

InGaAs eqitaxial layers have been selectively grown on patterned GaAs(100) substrates by chemical beam epitaxy (CBE) using triethylgallium (TEGa), trimethylindium (TMIn), and unprecracked monoethylarsine (MEAs). Facet growth of InGaAs epilayers has also been investigated at the various growth temperatures and Si4N4 dielectric pattern directions. In [011] jirection of mask, the change from (311), (377) and (111) facets to (311) facet with increasing growth temperature was observed. In [011] direction, however, the change from (011) and (111) facets to (111) facet with increasing growth temperature was observed. These results are attributed to the sidewall growth caused by different surface migration lengths of reactants. The formation of U-shaped (100) top surface is also discussed in terms of dangling bond model.

• Journal of Powder Materials
• /
• v.7 no.4
• /
• pp.237-243
• /
• 2000

The property and performance of the $Al_2O_3/Ni$ nanocomposites have been known to strongly depend on the structural feature of Ni nanodispersoids which affects considerably the structure of matrix. Such nanodispersoids undergo structural evolution in the process of consolidation. Thus, it is very important to understand the microstructural development of Ni nanodispersoids depending on the structure change of the matrix by consolidation. The present investigation has focused on the growth mechanism of Ni nanodispersoids in the initial stage of sintering. $Al_2O_3/Ni$ powder mixtures were prepared by wet ball milling and hydrogen reduction of $Al_2O_3$ and Ni oxide powders. Microstructural development and the growth mechanism of Ni dispersion during isothermal sintering were investigated depending on the porosity and structure of powder compacts. The growth mechanism of Ni was discussed based upon the reported kinetic mechanisms. It is found that the growth mechanism is closely related to the structural change of the compacts that affect material transport for coarsening. The result revealed that with decreasing porosity by consolidation the growth mechanism of Ni nanoparticles is changed from the migration-coalescence process to the interparticle transport mechanism.

• Journal of Environmental Impact Assessment
• /
• v.18 no.3
• /
• pp.161-170
• /
• 2009

As urban growth continues, the earth ecosystem is increasingly dependent on the patterns of urban growth. The impact intensity from urban growth is expected to change predictably with distance from the urban center. However we can't fully understand yet how urban development pattern affects urban ecosystem. In researches about urban ecosystem, it is important to relate the spatial pattern of urbanization to ecological processes. So we used gradient analysis with time data; 1980's, 1990's and 2000's. We attempted to quantify the urban spatiotemporal impacts in Daejeon-city and Cheonan-city, Korea, along a 75km long and 3km wide transect. Through the results, we found the impacts range of urbanization with urban development process of two cities. When the urban growth was concentrated on in both cities, the impacts intensity and range were much stronger and wider. As a result, in urban planning or green space planning, we have to consider suitable urban development forms with surrounding areas, and make legal clauses which limits landuse change. This quantifying the urban gradient is an important step in understanding urban ecology.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.3
• /
• pp.395-405
• /
• 2012

This study was investigated 35 government-authorized and officially approved textbooks for the Fisheries and marine high school which were published by the 2007 Revised Curriculum at 2009 for analyzing the objective and content domains concerning school the low carbon green growth education. Prior to the grounds of analyzing for the objective and content domains were presented, the factors of the grounds were made based on the low carbon green growth standards for the nation. According to the analysis, the findings which were as follows; 18(51.4%) in 35 textbooks and 666(6.4%) in 10,406 pages were related the low carbon green growth education in the course of the Fisheries and marine high school education. There were 37 participation domains, 27 information and knowledge domains, 9 value and attitude domains and 6 skill domains in the objective domains. The content domains were consisted of 33 green growth, 23 climate change, 10 energy conservation, 6 low carbon and 6 international cooperation.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2011.11a
• /
• pp.48-48
• /
• 2011

• Journal of Climate Change Research
• /
• v.1 no.2
• /
• pp.121-131
• /
• 2010

This study was carried out to evaluate spatial variations in rice production areas by simulating rice growth and yield with CERES-Rice growth model under GCM $2{\times}CO_2$ climate change scenarios. A modified window version(v4.0) of CERES-Rice was used to simulate the growth and development of three varieties, representing early, medium, and late maturity classes. Simulated growth and yield data of the three cultivars under the climate for 1971 to 2000 was set as a reference. Compared with the current normal(1971 to 2000), heading period from transplanting to heading date decreased by 7~8 days for the climate in $2^{\circ}C$ increase over normal, and 16~18 days for the climate in UKMO with all maturity classes, while change of ripening period from heading to harvesting date was different with maturity classes. That is, physical maturity was shortened by 1~3 days for early maturity class and 14~18 days for late maturity class under different climate change scenarios. Rice yield was in general reduced by 4.5%, 8.2%, 9.9%, and 14.9% under the climate in $2^{\circ}C$, $3^{\circ}C$, $4^{\circ}C$, and about $5^{\circ}C$ increase, respectively. The yield reduction was due to increased high temperature-induced spikelet sterility and decreased growth period. The results show that predicted climate changes are expected to bring negative effects in rice production in Korea. So, it is required for introduction of new agricultural technologies to adapt to climate change, which are, for example, developing new cultivars, alternations of planting dates and management practices, and introducing irrigation systems, etc.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.59 no.4
• /
• pp.27-42
• /
• 2017

The global rise in atmospheric $CO_2$ concentration and its associated climate change have significant effects on agricultural productivity and hydrological cycle. For food security and agricultural water resources planning, it is critical to investigate the impact of climate change on changes in agricultural productivity and water consumption. APEX-Paddy model, which is the modified version of APEX (Agricultural Policy/Environmental eXtender) model for paddy ecosystem, was used to evaluate rice productivity and evapotranspiration based on climate change scenario. Two study areas (Gimjae, Icheon) were selected and the input dataset was obtained from the literature. RCP (Representitive Concentration Pathways) based climate change scenarios were provided by KMA (Korean Meteorological Administration). Rice yield data from 1997 to 2015 were used to validate APEX-Paddy model. The effects of climate change were evaluated at a 30-year interval, such as the 1990s (historical, 1976~2005), the 2025s (2011~2040), the 2055s (2041~2070), and the 2085s (2071~2100). Climate change scenarios showed that the overall evapotranspiration in the 2085s reduced from 10.5 % to 16.3 %. The evaporations were reduced from 15.6 % to 21.7 % due to shortend growth period, the transpirations were reduced from 0.0% to 24.2 % due to increased $CO_2$ concentration and shortend growth period. In case of rice yield, in the 2085s were reduced from 6.0% to 25.0 % compared with the ones in the 1990s. The findings of this study would play a significant role as the basics for evaluating the vulnerability of paddy rice productivity and water management plan against climate change.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.222-227
• /
• 2002

This research will examine into the capabilities of KOMPSAI-1 EOC image application in the field of urban environment and at the same time, with that as its foundation, come to understand the urban changes of the study areas. This research is constructed in three stages: Firstly, for application of change detection techniques, which utilizes multi-temporal remotely sensed data, the data normalization process is carried out. Secondly, change detection method is applied fur the systematic monitoring of land use changes, which utilizes multi-temporal EOC images. Lastly, by using the results of the application of land use changes, the existing land use map is updated. Consequently, the land-use change patterns are monitored, which utilize multi-temporal panchromatic EOC image data; and application potentials of ancillary data fur updating existing data can be presented. In this research, with the use of the land use change, monitoring of urban growth has been carried out, and the potential for the application of KOMPSAT-1 EOC images and the scope of application was examined. Henceforth, the future expansion of the scope of application of KOMPSAT-1 EOC image is anticipated.