• Journal of the Korean earth science society
• /
• v.29 no.7
• /
• pp.523-530
• /
• 2008

The phase changes and variations of elemental contents in hematite medicinal mineral were investigated by a traditional processing operation including heating and quenching in vinegar. Hematite was processed at $650^{\circ}C$ and $900^{\circ}C$ through at least 5 processing cycles. Metal extraction tests in water were carried out with the processed hematite. Heating and quenching in vinegar could not change the phase of hematite. The effect of this traditional method was not clear because there were no variational trends between extracted elements and the number of processing cycles at $650^{\circ}C$ and $900^{\circ}C$. However, the traditional processing operation of heating and quenching in vinegar was very effective to change the hematite mineral towards soft and easily crushing medicinal material.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.4
• /
• pp.152-159
• /
• 2014

Urea solution as a reductant of SCR has been widely used to reduce NOx emissions from diesel engine. But it has lots of problems which are freezing at low temperature due to liquid state, deposition of solid formation in the exhaust, dosing device, and complex package such as mixers for uniform concentration of ammonia. In order to overcome these obstacle, ammonium carbonate which is one of solid ammonium materials to produce ammonia gas directly by sublimation process is considered. Simple reactor with visible widow was designed to predict equilibrium temperature and pressure of ammonium carbonate. To simulate real operation conditions under automobile environment, several cycles of heating and cooling condition were settled, two different re-solidification materials were extracted from the reactor and visible window. Analytical study is performed to characterize these unknown materials by XRD(X-Ray Diffraction), FT-IR(Fourier Transform Infrared Spectroscopy), and EA(Elemental Analyzer). From analytical results, re-solidification materials from heating and cooling cycles are very similar to original material of ammonium carbonate.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.10a
• /
• pp.140-141
• /
• 2016

Dynamic nature and diverse requirements on construction sites make the automation technology harder to be employed actively. In this study, we analyzed optimal type of automation system and importance of core technologies for developing efficient construction automation system on 11 construction operations. As a result, it showed that man-machine cooperation system may be the most suitable for most operations, while autonomous robot will be best suited in hard working environment such as maintenance of exterior wall. In elemental technology, ease and accuracy of control and operation showed higher priority than others regardless of automation system type. These findings will provide useful information for developing the construction automation system.

• Applied Chemistry for Engineering
• /
• v.7 no.4
• /
• pp.645-652
• /
• 1996

Selective catalytic oxidation of $H_2S$ to elemental sulfur using $TiO_2/SiO_2$ catalysts was investigated in this study. The reaction test with pure $TiS_2$ and $Ti(SO_4)_2$ and cyclic temperature operation revealed that $TiO_2$ had a good resistance to sulfation and sulfidation, which are known as the main cause of catalytic deactivation in sulfur recovery process. With the increase of $TiO_2$ loading amount in $TiO_2/SiO_2$ catalysts, the conversion of $H_2S$ increased and the selectivity of elemental sulfur was very slightly decreased. As the ratio of $O_2/H_2S$ increased, the selectivity to elemental sulfur was drastically decreased. In the presence of 10 vol.% water vapor to a stoichiometric mixture of $H_2S$ and $O_2$($H_2S$= 5 vol.% O=2.5 vol.% ), both activity and selectivity of 10 wt.% $TiO_2/SiO_2$ catalyst are decreased, but it still showed more than 80% of sulfur yield.

• Journal of The Korean Association For Science Education
• /
• v.6 no.2
• /
• pp.15-33
• /
• 1986

The main purpose of this study is to analyze the fourth and sixth grade in the elemental)' science contents using piagetian thinking patterns. An analysis of the elementary Science contents used the systems of Han Jong-Ha(1977), Lee Won-Shic and Lee Sang-On(1979). They analyzed the science contents based on Piagets' cognitive developmental stages. According to the results of this study, science contents consist of more difficult concepts those of children's thinking level. In other words, 6.4-19.3 percent to 23.5-25.0 percent in the fourth and sixth grade of the science contents are consisted with abstract level concepts that formal operational children can perform. But each grade, 99.2-95.3 percent of children have a difficulty in understanding such a abstract level concepts. They are in the concrete operation thinking level. Therefore, we say that children have difficulty in understanding of science contents and may lose interest in the contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.04a
• /
• pp.36-36
• /
• 2008

Organic light-emitting device (OLED) have become very attractive due to their potential application in flat panel displays. One important problem to be solved for practical application of full-color OLED is development of three primary color (Red, Green and Blue) emitting molecule with high luminous operation. Particularly, the development of organic materials for blue electroluminescence (EL) lags significantly behind that for the other two primary colors. For this reason, Flu-Si was synthesized and characterized by means of high-resolution mass spectro metry and elemental analyses. Flu-Si has the more wide optical band gap (Eg = 3.86) than reference material (Cz-Si, Eg = 3.52 eV). We measured the photophysical and electrochemical properties of Flu-Si. The HOMO-LUMO levels were estimated by the oxidation potential and the onset of the UV-Vis absorption spectra. The EL properties were studied by the device fabricated as a blue light emitting material with FIrpic.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.2
• /
• pp.37-46
• /
• 2004

The electrochemical adsorption of the Ag ions from aqueous solution on pelletized activated carbon monolith was investigated over wide range of operation time. The adsorption capacities of pelletized activated carbon monolith are associated with their internal porosity and are related properties such as surface area, pore size distribution. The chemical industry generates wastewater that contains toxic matters like heavy metals in small concentrations so that their economic recovery is not feasible. But, the method using activated carbon monolith can be used to withdrawal of heavy metals in waste water. After the electrochemical treatment, the quantitative properties in Ag ion solutions are also examined by pH concentration and studied elemental analysis by ICP-Atomic Emission Spectrometer and Energy Disperse X-ray (EDX) spectra. It is consider that the pH is very important factor at the reason of water pollutant with increasing acidity in industrial field. The result of quantitative analysis using Inductively Coupled Plasma-Atomic Emission Spectrometer of metal after electrochemical reaction in Ag ions solution depending on time are shown that the amount of Ag ions deposited was decreased with growth of Ag particles on the carbon surfaces as increasing electrochemically treated time. And, surface morphologies are investigated by scanning electron microscopy (SEM) to explain the changes in adsorption properties.

• Journal of the Korean Society for Library and Information Science
• /
• v.49 no.1
• /
• pp.173-200
• /
• 2015

This study is to seek a development plan in the borrowed book and current condition of operation of J-do provincial library. Based on library use card issuer 30,072 people and the number of lending books 705,447(2012 to 2013) of J-do provincial library, it was to analyzed elemental and comparative research for library development plan and user satisfaction. Method of analysis used SPSS statistics 21. This confirmed provincial library user's library user behavior and usage pattern of data. Based on the results of analytics, it indicated a development plan of J-do provincial library.

• Nuclear Engineering and Technology
• /
• v.52 no.10
• /
• pp.2394-2401
• /
• 2020

Octadecylamine is an effective film-forming amine that protects carbon steel from corrosion. In the present study, the effect of octadecylamine concentration on adsorption on a carbon steel surface was investigated in anaerobic alkaline solution by using SEM/EDS, TEM and the Materials Studio simulation techniques. TEM morphology observation and EDS elemental detection determine the thicknesses of octadecylamine film on a carbon steel surface, which are confirmed by the in-situ electrochemical impedance spectroscopy measurement and resistance calculation. The Materials Studio simulation reveals the number of octadecylamine film layers at different concentrations. Results obtained in this study indicate that adsorption of octadecylamine film on carbon steel proceeds with the multi-layer adsorption mechanism.

• International Journal of High-Rise Buildings
• /
• v.11 no.2
• /
• pp.87-102
• /
• 2022

In Japan, the population progresses to the extreme aging society and it is entering the phase of the population decrease while the population increase is continuing in the world. The construction market is expected to shrink accordingly, however the situation of labor shortage is expected to continue at a faster rate, because the aging of construction workers is progressing and new younger labor force cannot be secured. In order to supplement the labor shortage, it is required to progress mechanization, automation, labor saving, and efficiency improvement by utilizing the information well in each stage in a series of flow of planning, design, construction, operation, and disassembly in one building. The measures to maintain and expand the construction market by the new efficiency improvement techniques which enhance the utilization degree of building information are required. Currently, the elemental technologies which utilized BIM (Building Information Modeling) are accumulated by advancing digitization in each phase. DX (Digital transformation) in the construction industry can be achieved by the technology maturing and having a series of continuities. It is anticipated that this will evolve to a new method which is unprecedented. Present status of BIM and mechanized constructions in Taisei Construction are introduced, and future prospect is described.