• Applied Chemistry for Engineering
• /
• v.25 no.4
• /
• pp.346-351
• /
• 2014

With the world population's continuous growth and urban industrialization, capacitive deionization (CDI) has been proposed as a next-generation water treatment technology to augment the supply of water. As a future water treatment method, CDI attracts significant attention because it offers small energy consumption and low environmental impact in comparison to conventional methods. Carbon electrodes, which have large surface area and high conductivity, are mainly used as electrode materials of choice for the removal of ions in water. A variety of carbon materials have been investigated, including their adsorption-desorption behavior in accordance to the specific surface area and pore size distribution. In this review, we analyzed and highlighted these carbon materials and looked at the impact of pore size distribution to the overall CDI efficiency. Finally, we propose an optimal condition in the interplay between micropores and mesopores in order to provide the best electrosorption property for these carbon electrodes.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.29 no.3
• /
• pp.223-228
• /
• 2023

Sustainable energy supplies without the recharging and replacement of the charge storage device have become increasingly important. Among various energy harvesters, the triboelectric nanogenerator (TENG) has attracted considerable attention due to its high instantaneous output power, broad selection of available materials, eco-friendly and inexpensive fabrication process, and various working modes customized for target applications. In this study, the amount of voltage and current generated was measured by applying the PSD profile random vibration test of the electronic vibration tester and ISTA 3A according to the time of Anodized Aluminum Oxide (AAO) pore widening of the manufactured TENG device Teflon and AAO. The discharge and charging tests of the integrated module during the random simulated transport environment and the recognition distance of RFID were measured while agricultural products (onion) were loaded into the returnable folding plastic box. As a result, it was found that AAO alumina etching processing time to maximize TENG performance was optimal at 31 min in terms of voltage and current generation, and the integrated module applied with the TENG module showed a charging effect even during the continuous use of RFID, so the voltage was kept constant without discharge. In addition, the RFID recognition distance of the integrated module was measured as a maximum of 1.4 m. Therefore, it was found that the surface condition of AAO, a TENG element, has a great influence on the power generation of the integrated module, and due to the characteristics of TENG, the power generation increases as the surface dries, so it is judged that the power generation can be increased if the surface drying treatment (ozone treatment, etc.) of AAO is applied in the future.

• Tunnel and Underground Space
• /
• v.7 no.1
• /
• pp.39-50
• /
• 1997

Reference concepts for the disposal of spent nuclear fuel and the current status of underground rock laboratory were studied. An analysis to simulate the deep disposal of spent nuclear fuel in saturated rock mass was conducted. Main input parameters for numerical study were determined based on the KBS-3 concept. A series of results showed that the temperature distribution around a cavern reached the maximum value at about 10 years after the emplacement of spent fuel. The maximum temperature at the surface of canister was more than about 12$0^{\circ}C$ at about 4 years. This temperature was not much higher than the temperature criteria to meet the performance criteria of an artificial barrier in the KBS-3 concept. The maximum upward displacement due to the heat generation of spent fuel was about 0.9cm at about 10 years after the emplacement of spent fuel. It turned out that the vertical displacement became smaller with the decrease in heat generation of a canister. The quantity of groundwater inflow into a disposal tunnel increased by about 1.6 times at 20 years after the emplacement of spent fuel with the increase of pore pressure around a cavern.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.610-612
• /
• 2008

Piston cores retrieved from the eastern part of the deep-water Ulleung Basin were analyzed to access the potential of hydrocarbon gas generation and natural gas hydrate (NGH) formation. Seismic data acquired in the study area were also analyzed to determine the presence of hydrocarbon gas and/or NGH, and to map their distribution. Core analyses revealed high total organic carbon (TOC) contents which favor hydrocarbon generation. The cores recovered from the southern study area showed the sufficient residual hydrocarbon gas concentrations for the formation of significant NGH. These cores also showed the cracks developed parallel to the bedding that suggest significant gas content in situ. A number of seismic blanking zones were observed on seismic data. They are identified as vertical to sub-vertical chimneys caused by the upward migration of pore fluid or gas, and containing of free gas and/or NGH. Often, they are associated with velocity pull-up structures that are interpreted to be the result of high-velocity NGH. The seismic data also showed several bottom-simulating reflectors (BSRs) that are associated with overlying NGH and underlying free gas. The distribution of blanking zones and BSRs would be impacted by the lateral differences of upward methane fluxes.

• Biomolecules & Therapeutics
• /
• v.26 no.2
• /
• pp.182-190
• /
• 2018

The objective of this work is to evaluate the effect of polyamidoamine (PAMAM) dendrimers on electroosmotic flow (EOF) through skin. The effect of size and concentration of dendrimer was studied, using generation 1, 4 and 7 dendrimer (G1, G4 and G7, respectively). As a marker molecule for the direction and magnitude of EOF, a neutral molecule, acetoaminophen (AAP) was used. The visualization of dendrimer permeation into the current conducting pore (CCP) of skin was made using G4-fluorescein isothiocyanate (FITC) conjugate and confocal microscopy. Without dendrimer, anodal flux of AAP was much higher than cathodal or passive flux. When G1 dendrimer was added, anodal flux decreased, presumably due to the decrease in EOF by the association of G1 dendrimer with net negative charge in CCP. As the generation increased, larger decrease in anodal flux was observed, and the direction of EOF was reversed. Small amount of methanol used for the preparation of dendrimer solution also contributed to the decrease in anodal flux of AAP. Cross-sectional view perpendicular to the skin surface by confocal laser scanning microscope (CLSM) study showed that G4 dendrimer-FITC conjugate (G4-FITC) can penetrate into the viable epidermis and dermis under anodal current. The permeation route seemed to be localized on hair follicle region. These results suggest that PAMAM dendrimers can permeate into CCP and change the magnitude and direction of EOF. Overall, we obtained a better understanding on the mechanistic insights into the electroosmosis phenomena and its role on flux during iontophoresis.

• 보존과학연구
• /
• s.21
• /
• pp.273-291
• /
• 2000

The perilla oil is painted to the wooden cultural properties of protection of wood and pigment. But that is happened to discolor and gather mold because of the long drying time. So we were put to the test for the improvement of this matter. The result is follows;1. The perilla oil, do not parched domestic Perilla japonica, add to the Japanese acid clay, later passing through the filter paper that the pore size is less than $7\mum$ 2. If the perilla oil add to the antiseptic of Thiazole origin, the mold is suppressed.3. In the painting of perilla oil, the existing Dan-chung paints one time (Luster generation in the more than two times) and the non-existing Dan-Chung paints two times.

• Journal of the Korean Ceramic Society
• /
• v.53 no.5
• /
• pp.548-556
• /
• 2016

Recently, porous alumina-based ceramics have been extensively applied in the semi-conductor and display industries, because of their high mechanical strength, high chemical resistance, and high thermal resistance. However, the high electrical resistance of alumina-based ceramics has a negative effect in many applications due to the generation of static electricity. The low electrical resistance and high air permeability are key aspects in using porous alumina-based ceramics as vacuum chucks in the semi-conductor industry. In this study, we tailored the pore structure of porous alumina-based ceramics by adjusting the mixing ratio of the starting alumina, which has different particle sizes. And the electrical resistance was controlled by using chemical additives. The characteristics of the specimens were studied using scanning electron microscopy, mercury porosimetry, capillary flow porosimetry, a universal testing machine, X-ray diffraction, and a high-resistance meter.

• Journal of Pharmaceutical Investigation
• /
• v.23 no.4
• /
• pp.207-211
• /
• 1993

Reservoir type devices were designed for long-term implantable drug delivery system. The reservoir type device was prepared with the polymethacrylic acid gel coated with polyurethane membrane. Release controlling agent (RCA) were employed to control drug release from devices via generation of micropores in the membranes. The polyurethane membrane functioned as a rate controlling barrier. The drug release pattern of hydrogel demonstrated zero order kinetics. The release rate of drugs could be regulated by varying hydrophobicity/hydrophilicity and content of the RCA, as well as the thickness of the polyurethane membrane. The release of drugs from this system was governed by pore mechanism via simple diffusion and osmotic pressure.

• 연구논문집
• /
• s.24
• /
• pp.81-96
• /
• 1994

To investigate failure mechanisms observed in carbon-phenolic thermal insulators, differential equations which govern the decomposition process in a deformable anisotropic porous solid are derived for three-dimensional axisymmetric constructions. The governing equations not only couple the material deformation with pore pressure, but also couple pressure and temperature, which means that heat convected by the pyrolysis gases is properly accounted for. Then the Bubnov-Galerkin finite element method is applied to these equations to transform them into a semidescrete finite element system. A thermal insulation liner in the cowl region under typical operating conditions is analyzed to find a mechanism for plylift. The results from the structural analysis show across-ply failure in the cowl zone. The mechanism for plylift is hypothesized as a sequential procedure : 1) the across-ply failure which is the precursor to plylift and 2) the local fiber buckling caused by generation of excessive in-plane compressive stress. To prevent plylift, the across-ply stress can be reduced by using appropriate material ply angles in cowl zone design.

• Journal of the Korean Ceramic Society
• /
• v.56 no.1
• /
• pp.77-83
• /
• 2019

MgO-C refractories are used in basic furnaces and steel ladles due to their many desirable properties, such as excellent thermal shock resistance via low thermal expansion, and high thermal conductivity. However, the mechanical and thermal properties of the refractory continuously deteriorate by spalling phenomena and pore generation due to the oxidation of graphite, used as a carbon source, indicating that the characteristics and performance of MgO-C refractories need to be improved by using a new material or composition. In this study, the use of a Hertzian indentation test as a method for determining the damage and fracture behavior of an MgO-C refractory is described. The results highlight that Hertzain indentation tests can be one of the important evaluation tools for quasi-plastic damage accumulation of MgO-C refractories during falling process of scrap metal.