• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.348-354
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• 2009

Copper(II) complexes with tetraoxo dithia tetraaza macrocyclic ligands; [18]ane$N_4S_2$: 1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, [20]ane$N_4S_2$: 1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane,Bzo2[18]ane$N_4S_2$: dibenzo-1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, Bzo2[20]ane$N_4S_2$: dibenzo-1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane; were entrapped in the nanopores of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)copper(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); $[Cu(N-N)_2]^{2+}$-NaY; in the nanopores of the zeolite, and (ii) in situ template condensation of the copper(II) precursor complex with thiodiglycolic acid. The obtained complexes and new host-guest nanocomposite materials; $[Cu([18]aneN_4S_2)]^{2+}-NaY,\;[Cu([20]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[18]aneN_4S_2)]^{2+}-NaY,\;[Cu(Bzo_2[20]aneN_4S_2)]^{2+}$-NaY; have been characterized by elemental analysis FT-IR, DRS and UV-Vis spectroscopic techniques, molar conductance and magnetic moment data, XRD and, as well as nitrogen adsorption. Analysis of data indicates all of the complexes have been encapsulated within nanopore of zeolite Y without affecting the zeolite framework structure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.469-481
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• 2013

The monitoring of a free surface generated by waterjet cutting technology is very important for an efficient construction process. In this study, experiments using a laser sensor were performed to provide a data processing method and to determine optimized parameters. The experimental parameters here are the angular resolution, measurement distance, and free surface cutting shape. The results show that the monitoring resolution increases with a decrease in the angular resolution and the horizontal measurement distance and with an increase in the cutting (free surface) width. This laser monitoring method can be applied during the measurement of free surface shapes and depths in situ.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2003.03a
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• pp.113-120
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• 2003

The estimation of the coeff. of permeability is a major process that influenced in very large portion to the changing of gound water movement and estimation of the outflow’s quantity in the ground water movement modelling. To overcome the error caused by difficulty of the ground investigation for the hydraulic parameter’s estimation, in this paper, we study of correlation between electric resistivity and coeff. of permeability, and analyse of coeff. of permeability from electric resistivity. To accomplish this purpose, we carry out electrical logging, AMT survey as an in-situ test, and measure electric resistivity, porosity, permeability for the intact rock as a laboratory test. Based on the results of this research, it can be applied that estimation of the coeff. of permeability using electrical logging and AMT survey is a effective method for the impossible area of the ground investigation caused by geographical condition and petition.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.411-434
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• 2022

In deep geological disposal concept for spent nuclear fuel, it is well-known that rock mass at near-field experiences the thermal-hydraulic-mechanical (THM) coupled behavior. The mechanical properties of rock changes during the coupled process, and it is important to consider the changes into the analysis of numerical simulation and in-situ tests for long-term stability evaluation of nuclear waste disposal repository. This report collected the previous studies on indirect coupled behaviors of rock. The effects of water saturation and temperature on some mechanical properties of rock was considered, while the change in hydraulic conductivity of rock due to stress was included in the indirect coupled behavior.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.406-412
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• 2018

This paper describes the fabrication process of laser induced graphene (LIG) and its transfer method on to a flexible and stretchable PDMS substrate. By irradiating CO2 laser on a polyimide(PI) film surface, a localized high temperature is created, resulting in a three-dimensional porous graphene network structure with good conductivity. This LIG electrode is relatively easy to fabricate and since it is very weak the LIG electrode was transferred to a flexible PDMS substrate to increase the sturdiness as well as possible use in flexible applications. Sheet resistance, thickness, and electrochemical activity of the fabricated in-situ LIG electrodes have been examined and compared with the LIG electrodes after transferring to PDMS elastomer. The properties of the LIG electrodes were also examined depending on the $CO_2$ laser power. As the irradiated laser power increased, the LIG electrode resistance decreases and the LIG electrode thickness increased. At 4.8 W of laser power, the average sheet resistance and thickness of the fabricated LIG electrodes were approximately $31.7{\Omega}/{\Box}$ and $62.67{\mu}m$, respectively. Moreover, the electrochemical activity of the fabricated LIG electrode at 4.8 W of laser power showed a high oxidation current of $28.2{\mu}A$ after transferring to PDMS.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.178-184
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• 2007

In the present work, the vermicomposting index was investigated using leakage water from sludge to develop the process of mechanization and automation in the earthworm-cast treatment. The in situ sewage sludge was used batch and continuous experiments. Due to different treatment processes, the physico-chemical characteristics of liquid extracted from sludge was the similar change pattern. However, some items, such as Oxidation Reduction Potential (ORP), pH, Electrical Conductivity (EC) and $NH_3-N$, showed the distinct changes between pre- and post-vermicomposting. Also, The ORP and EC were the best parameters for the vermicomposting index. These results offered that the present vermicomposting technology was an actual earthworm-cast treatment.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.30-36
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• 1998

For successful soil flushing process selection of appropriate flushing reagents is essential. Futhermore, obtaining operating parameters for site remediation application through various bench-scale tests is also important. In this research a series of organic acids (acetic, citric, oxalic, and succinic acids) were tested for flushing capability. Copper-contaminated natural soil was used as a test medium, and flushing experiments were performed with batch system. All the organic acids used did not provide effective flushing conditions at concentration of 1 mM. At the acid concentration of 50 and 100 mM copper was removed efficiently although 50 and 100 mM did not show any significant differences in removal efficiencies. Citric acid and oxalic acid removed copper more efficiently than the others, and especially, citric acid showed over 87% of removal efficiency of copper at near neutral pH of 5 to 7. Speciation of extracted copper using GEOCHEM simulation showed majority of extracted copper existed as complexed with organic acids and only small portion of organic acids were complexed with copper indicating promising application of soil flushing with organic acid to heavy metal-contaminated site remediation.

• Journal of Powder Materials
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• v.22 no.5
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• pp.356-361
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• 2015

Fe-30 wt% TiC composite powders are fabricated by in situ reaction synthesis after planetary ball milling of (Fe, $TiH_2$, Carbon) powder mixture. Two sintering methods of a pressureless sintering and a spark-plasma sintering are tested to densify the Fe-30 wt% TiC composite powder compacts. Pressureless sintering is performed at 1100, 1200 and $1300^{\circ}C$ for 1-3 hours in a tube furnace under flowing argon gas atmosphere. Spark-plasma sintering is carried out under the following condition: sintering temperature of $1050^{\circ}C$, soaking time of 10 min, sintering pressure of 50 MPa, heating rate of $50^{\circ}C/min$, and in a vacuum of 0.1 Pa. The curves of shrinkage and its derivative (shrinkage rate) are obtained from the data stored automatically during sintering process. The densification behaviors are investigated from the observation of fracture surface and cross-section of the sintered compacts. The pressureless-sintered powder compacts are not densified even after sintering at $1300^{\circ}C$ for 3 h, which shows a relative denstiy of 66.9%. Spark-plasma sintering at $1050^{\circ}C$ for 10 min exhibits nearly full densification of 99.6% relative density under the sintering pressure of 50 MPa.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.221-226
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• 1998

Amorphous (Ba, Sr)$TiO_3$[BST] layer(30, 70 nm) was introduced between crystalline BST and $RuO_2$electrode to realize double-layered BST structure in order to improve the properties of BST film. The structure and surface morphology of double-layered BST film were modified by the application of amorphous BST layer; that is, surface became smoother and grain size increased abruptly. Amorphous layer thicker than 30 nm was effective to hinder the influence of $RuO_2$surface on the structure of as-grown BST films by in-situ process. Dielectric constant of double-layered BST film was improved dramatically from 152 to 340 and leakage current was lowered from $1.25{\times}10^{-5}A/{\textrm}{cm}^2);to;6.85{\times}10^{-7}A/{\textrm}{cm}^2$, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.5
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• pp.437-441
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• 2014

This paper presents a novel microplatform for high power generation based on reverse electrodialysis. The ideal cation-selective membrane for power generation was realized using geometrically controlled in situ self-assembled nanoparticles. Our proposed membranes can be constructed through a simple and cost-effective process that uses microdroplet control with nanoparticles in a microchannel. Another advantage of our system is that the maximum power and energy conversion efficiency can be improved by changing the geometry of the microchannel and proper selection of the nanoparticle size and material. This proposed platform can be used to supply power sources to other microdevices and contribute to a fundamental understanding of ion transport behavior and the power generation mechanism.