• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.25 no.6
• /
• pp.386-393
• /
• 2013

After the 2011 Tohoku Earthquake, it has been pointed out that Tokai, Tonankai and Nankai massive earthquakes with a magnitude of 9.0 could strike the Pacific coasts in western Japan. This study aims at investigating numerically propagation characteristics of tsunami generated by a 9.0 magnitude Tokai, Tonankai and Nankai massive earthquakes on the Pacific coasts and three major bays in Japan, Tokyo Bay, Ise Bay and Osaka Bay. It was revealed from the numerical results that the tsunami heights on the Pacific coasts for M9.0 earthquake were about twice as much as those for M8.7 earthquake and the first tsunami arrival time was faster at some areas distant from the tsunami source. Moreover, high water level in the bays was recognized to continue for a long time because of the enclosed bays.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.1
• /
• pp.33-40
• /
• 2023

Todorokite is a manganese oxide mineral containing Mg²⁺ in a tunnel structure in which MnO₆ octahedra share corners. In order to investigate the suitability and efficiency of high temperature-treated todorokite as a material for adsorption and fixation of Cs, Cs was ion exchanged and the amount of leached Cs from todorokite was measured. The todorokite used in this study was synthesized by transforming Na-birnessite to Mg-buserite and used as a precursor. After high temperature treatment, Cs exchanged todorokite changed to birnessite and hausmannite as the temperature increased. The amount of leached Cs was investigated for Cs exchanged todorokite which was reacted with distilled water and 1 M NaCl solution at different reaction times. In general, for the samples reacted with 1 M NaCl solution, the fixation of Cs was quite effective, although the amount of leached Cs was greater due to the ion exchange reaction with Na. As the treatment temperature increased, the amount of leached Cs increased and then decreased again, which was related to the mineral phases formed at each temperature. As birnessite was formed, the amount of leached Cs increased, but as birnessite decreased, that decreased again. As the mineral phase changed to hausemanite, the amount of Cs decreased rapidly. The results of our study show that Cs exchanged todorokite can be used as a material that effectively fixes Cs and prevents its diffusion by high temperature treatment.

• Journal of the Mineralogical Society of Korea
• /
• v.13 no.4
• /
• pp.205-220
• /
• 2000

북동태평양 C-C지역의 우리나라 광구에서 산출되는 망간단괴의 내부조직을 크게 주상조직 층상대, 첨상조직 층상대, 첨상조직 괴상대, 첨상조직 다공질대 및 괴상조직 괴상대로 구분하였다. 주상조직 층상대에서는 버나다이트(vernadite)가 가장 우세하게 산출되며, 첨상조직 층상대에서는 부서라이크(buserite)가 함께 산출된다. 첨상조직 괴상대는 부서라이트의 산출이 두드러지며, 부분적으로 토도로카이트(todorokite)가 수반된다. 첨상조직 다공질대는 첨상체 또는 구상체로 이루어지며 부분적으로 괴상조직으로 교대되는데 주로 토도로카이트와 부서라이트로 구성되어 있다. 괴상조직을 갖는 괴상대에서는 토도로카이트와 버네사이트(birnessite)가 부서라이트와 함께 산출된다. 각 조직대별로 미세조직을 이루는 엽리들에 대해 전자현미분석을 실시하였다. 엽리의 화학조성을 구성하는 요인은 상관계수 군집분석에 의해 Mn-K의 Mn군, Cu-Ni-Zn-Mg(Ca-Na)의 Cu-Ni-Mg군 Fe-Co-Ti(Ca-P)의 Fe군과 Si-Al의 Si군 등 네 개군으로 구분된다. 각 조직대는 세 개 또는 네 개의 군으로 구성되며 이들 각군은 단괴에서 산출되는 광물과 밀접한 관계를 가진다. Mn군은 토도로카이트, Cu-Ni-Mg군은 부서라이트, Fe군은 함코발트수산화철광물, 그리고 Si군은 규산염광물에서 주로 기인하는 것으로 생각된다. 엽리의 화학조성은 이들 광물의 조합과 구성광물의 화학조성에 따라 지배되고 한 조직대내에서도 여러종류의 조합을 보이는데 이는 각 조직대의 엽리들의 성인과 밀접한 관련이 있는 것으로 생각된다.

• Journal of the Korean Society for Library and Information Science
• /
• v.38 no.1
• /
• pp.13-34
• /
• 2004

The Reference Model for an Open Archival Information system(OAIS) was recommended for developing digital archives effectively and for implementing interoperability and resource sharing between digital archives. But as the Reference Model is high-level recommendation, it does not specify a design and an implementation. Therefore, this study investigates the architecture of several digital archives, suggestes three strategies for persistent archive, and proposes the conceptual model for developing trusted, persistent, and secure digital archive.

• Journal of the Mineralogical Society of Korea
• /
• v.32 no.3
• /
• pp.151-162
• /
• 2019

Todorokite, a tunnel-structured manganese oxide, can contain cations within the relatively large nanopores created by the $3{\times}3$ Mn octahedra. Because todorokite is poorly crystalline and found as aggregates mixed with other phases of Mn oxides in nature, the coordination structure of cations in the nanopores is challenging to fully characterize in experiment. In the current article, we report the atomistic coordination structures of $Mg^{2+}$ ions in todorokite tunnel nanopores using the classical molecular dynamics (MD) simulations. In experiment, $Mg^{2+}$ is known to occupy the center of the nanopores. In our MD simulations, 60 % of $Mg^{2+}$ ions were located at the center of the nanopores; 40 % of the ions were found at the corners. All $Mg^{2+}$ located at the center formed the six-fold coordination with water molecules, just as the ion in bulk aqueous solution. $Mg^{2+}$ ions at the corners also formed the six-fold coordination with not only water molecules but also Mn octahedral surface oxygens. The mean squared displacements were calculated to examine the dynamic features of $Mg^{2+}$ ions in the one-dimensional (1D) nanopores. Our MD simulations indicate that the dynamic features of water molecules and the cations observed in bulk aqueous solution are lost in the 1D nanopores of todorokite.

• Journal of the Korean Society for Library and Information Science
• /
• v.47 no.2
• /
• pp.315-335
• /
• 2013

As the indigenous history of the city gets recorded and today's history is lively reflected as it draws breath, the city will have its own symbolic images. This study is to show the new city archives of building direction by the status survey and analysis of the city archives based on theoretical study in respect of the comprehension of the characteristics of the city and the need to archive. To this end, the city of Seoul, Busan, and Wonju, was surveyed and were given the suggestion it should efficiently build its city archive based on the results of its analysis.

• 도로교통
• /
• s.100
• /
• pp.107-114
• /
• 2005

• The Bimonthly Magazine for Agrochemicals and Plant Protection
• /
• v.13 no.3 s.108
• /
• pp.44-50
• /
• 1992

• Radioisotope journal
• /
• v.16 no.3
• /
• pp.78-82
• /
• 2001

• Radioisotope journal
• /
• v.16 no.3
• /
• pp.83-88
• /
• 2001