• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.10
• /
• pp.4672-4678
• /
• 2013

Aluminum dross is formation at the surface of the molten metal as the latter reacts with the furnace atmosphere and it was an unavoidable by-product of the aluminum production process. However aluminum dross was usually landfilled or disposed without treatment, causing much environmental damage. The purpose of this study is to investigate the possibility of ceramic catalyst support using recycled Al dross. The recycled Al dross was made into SCR catalyst by mixing with $WO_3$, $V_2O_5$ and $TiO_2$. The $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR catalyst was observed with XRF, XRD and BET. $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR strength was measured by Universal Testing Machine(UTM). As the added $Al_2O_3$, streagth is increased. And the NOx removal activity was observed by MR(Micro-Reactor). The temperatures ranging from $350^{\circ}C$ and $400^{\circ}C$, $V_2O_5-WO_3/TiO_2-Al_2O_3$ SCR catalyst De-NOx performance result of showed excellent activity over 90% at application condition.

• Korean Journal of Clinical Laboratory Science
• /
• v.52 no.1
• /
• pp.53-61
• /
• 2020

Cell migration is a central process for recovering from wounds triggered by physical distress besides embryogenesis and cancer metastasis. Wound healing assay is widely used as a fundamental research technique for investigation of two-dimensional cell migration in vitro. The most common approach for imitating physical wound in vitro is mechanical scratching on the surface of the confluent monolayer by using sharp materials. The iron metal pin with a suspension spring for fine adjustment of the orthogonal contact surface between the scratching point and the individual bottom of multi-well plate with planar curvatures were adopted for the creative invention of a 96-well plate wound maker. While classic tips drew diverse and zigzag scratching patterns on the confluent monolayer, our wound maker displayed synchronized linear wounds in the middle of each well of a 96-well plate that was seeded with several cell lines. Given that several types of multi-well plates commercially available are compatible with our lab-made wound maker for creating uniform scratches on the confluent monolayer for the collective cell migration in wound healing assay, it is certain that the application of this wound maker to the real-time wound healing assay in high content screening (HCS) is superior than utilization of typical polypropylene pipette tips.

• Journal of Conservation Science
• /
• v.28 no.1
• /
• pp.53-62
• /
• 2012

The archival objects are tangible evidence related to the public service. They are unique and offer information representing the specific events, time or person. The archival objects as modern cultural heritage do not have the guideline to classify, manage and conserve them. Especially, it is difficult to apply general conservation process for burial artifacts, because there are few study example of conservation for metal archival objects and they have complex administrative value. We tried to find suitable material and application method for consolidation of copper alloy archival object. We choose three kinds of wax and acrylic resin for burial artifacts and had done comparative analysis of their characterizations following kinds and coating methods. As a result of evaluation by several surface analysis such as optical microscope, measuring film thickness, adhesive strength, contact angle and yellowing test, acrylic resin can use to archival objects of copper alloy, effectively but the method of heating after dip-coating with Wax B used before can get best effect of consolidation.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.42 no.6
• /
• pp.67-76
• /
• 2005

This paper proposes a compact-sized surface myoelectric sensor for the myoelectric hand prosthesis. To fit the surface myoelectric sensor in the socket for the myoelectric hand prosthesis, the sensor should be a compact size. The surface myoelectric sensor is. composed of a skin interface and a single processing circuit that are mounted on a single package. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper we propose two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, we select the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22 mm. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value circuit. We evaluate the proposed sensor from the output characteristics according to the IED and the shape of the reference electrode. From the experimental results we show the surface myoelectric sensor with the 18mm IED and the bar-shaped reference electrode is suitable for the myoelectric hand prosthesis.

• Journal of the Mineralogical Society of Korea
• /
• v.20 no.2 s.52
• /
• pp.71-81
• /
• 2007

The marble-type dolomite from the Jasung Mine, which was farmed by duplicated affects of contact metamorphism and subsequent hydrothermal alteration, corresponds to a high-purity dolomite ranging up to above 98wt.% in dolomite contents. The dolomite contain minor impurities such as quartz, muscovite, and pyrite. It is characteristic that the dolomite is fairy Fe-rich corresponding to 0.4 wt.% due to the presence of pyrite of possible hydrothermal origin. The dolomite is nearly white-colored and constituting with subhedral crystals ranging $0.35{\sim}0.46mm$M in size, forming equigranular texture. Compared to the typical high-Ca limestone from the Pungchon Formation, the powder characteristics of dolomite is rather superior in milling efficiency, yields of fine particles, and size distribution. In addition, except for iron contents, the dolomite powder is no less superior than the limestone in quality and characteristics as fillers with respects to not only whiteness, oil absorption, and specific surface area but also shape characters such as elongation ratio, aspect ratio, and sphericity. This good characteristics of dolomite powder seem to be originated basically from comparatively higher grade and crystallinity of dolomite. Higher iron contents and the presence of sulfides prevents the dolomite from application for uses by thermal treatment, except for metallic manufacture. However, if proper ore separation procedure is available, the dolomite can be sufficiently utilized as substitutes for high-Ca limestone in most fields of filler industries.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.1
• /
• pp.15-23
• /
• 2000

RC oscillation method was applied to study the condenser characteristics of two metal sticks insulated by vinyl tube and used in the dielectric constant determinations of most soils. Its capacitance as influenced by the contacted ambient materials was measured as relative capacitance of the sensor sticks compared with the standard one on the RC oscillation circuit. According to the equivalent circuit of the sensor stick set, the measured capacitance was composed of a basic capacitance connected in parallel with sensor stick capacitance, which was composed of lineally connected vinyl tube capacitances and the sensing part capacitance. The dielectric constant (U) of the contacted ambient moist soil located in the sensing part around the sticks interrelated with the other parameters as following equation. $$\frac{1}{C-B}=\frac{k}{U}+Z$$ where C is the output total relative capacitance, B is the hidden and fixed basic relative capacitance, k is a constant related with U, and Z is a constant for the insulating vinyl tube capacitances determined by its thickness and dielectric constant. The constant k is determined by the spacing and length of sensor sticks. The Z value is theoretically an invariable constant, but it may become considerably bigger than the determined in lab if air tube is formed on the surface of sensor sticks by some shocks on them after their installation in soil. Due to the unstability of lab Z value, it may be better to revise it after sensor stick's installation in soil and no shaking shocks should be applied on them.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.2
• /
• pp.155-164
• /
• 2014

Carbon-fiber-reinforced plastic (CFRP) composites are increasingly being used in a variety of industry applications, such as aircraft, automobiles, and ships because of their high specific stiffness and high specific strength. Aircraft are exposed to high temperatures and high humidity for a long duration during flights. CFRP materials of the aircraft can absorb water, which could decrease the adhesion strength of these materials and cause their volumes to change with variation in internal stress. Therefore, it is necessary to estimate the characteristics of CFRP composites under actual conditions from the viewpoint of aircraft safety. In this study air-coupled ultrasonic testing (ACUT) was applied to the evaluation of water absorption properties of CFRP composites. CFRP specimens were fabricated and immersed in distilled water at $75^{\circ}C$ for 30, 60, and 120 days, after which their ultrasonic images were obtained by ACUT. The water absorption properties were determined by quantitatively analyzing the changes in ultrasonic signals. Further, shear strength was applied to the specimens to verify the changes in their mechanical properties for water absorption.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
• /
• v.55 no.6
• /
• pp.527-537
• /
• 2018

Column tests of a sulfate reducing bacteria (SRB) bioreactor were conducted to determine the design factors for sulfate-rich mine drainage. Various substrates were applied to the bioreactor, including cow manure and its mixture with a mushroom compost, with rice straw and limestone as subsidiary materials. This procedure provided a removal efficiency of up to 82% of the total sulfur with the mixture of cow manure (70%), mushroom compost (10%) and rice straw (20%), and higher efficiencies were observed after 2 days of retention time. In the downflow condition of the flow direction, oxygen supply and re-oxidation of the sulfates occurred, causing a decrease in sulfate removal efficiency. The addition of an inorganic sludge containing heavy metals, which was intended for production of metal-sulfides in the bioreactor, had a negative effect on the long-term operation owing to arsenic release and toxicity to the SRB. The results thus show that a bioreactor using a mixed substrate with cow manure and operating in the downflow direction could reduce sulfates and total dissolved sulfur content; this process confirms the applicability of the SRB bioreactor to sulfate-rich saline drainage.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.175-181
• /
• 2019

In the case of a conventional single stage decompression regulator used for large depressurization in the hydrogen fuel cell system of a fuel cell electric vehicle (FCEV), problems can arise, such as pulsation, slow response, hydrogen brittleness, leakage, high weight, and high cost due to high decompression. Most of these problems can be overcome easily using two decompression mechanisms (two-stage structures). In addition, a wide outlet-pressure control range can be secured if an electronic solenoid is applied to the second decompression. Accordingly, it is necessary to improve the precision of the outlet pressure of a two-stage pressure-reducing regulator and develop techniques, such as leakage prevention, durability, light weight, and price reduction. Therefore, to improve the outlet pressure accuracy and prevent leakage, the structural part before and after decompression to improve the air tightness were divided and the analysis was carried out assuming that the valve part was closed (open ratio: 0%) after each initial internal pressure application.

• Journal of the Korean Electrochemical Society
• /
• v.22 no.3
• /
• pp.87-103
• /
• 2019

Nonaqueous organic electrolyte solution in commercially available lithium-ion batteries, due to its flammability, corrosiveness, high volatility, and thermal instability, is demanding to be substituted by safer solid electrolyte with higher cycle stability, which will be utilized effectively in large-scale power sources such as electric vehicles and energy storage system. Of various types of solid electrolytes, composite solid electrolytes with polymer matrix and active inorganic fillers are now most promising in achieving higher ionic conductivity and excellent interface contact. In this review, some kinds and brief history of solid electrolyte are at first introduced and consequent explanations of polymer solid electrolytes and inorganic solid electrolytes (including active and inactive fillers) are comprehensively carried out. Composite solid electrolytes including these polymer and inorganic materials are also described with their electrochemical properties in terms of filler shapes, such as particle (0D), fiber (1D), plane (2D), and solid body (3D). In particular, in all-solid-state lithium batteries using lithium metal anode, the interface characteristics are discussed in terms of cathode-electrolyte interface, anode-electrolyte interface, and interparticle interface. Finally, current requisites and future perspectives for the composite solid electrolytes are suggested by help of some decent reviews recently reported.