• Korean Journal of Materials Research
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• v.31 no.2
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• pp.75-83
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• 2021

To cope with automobile exhaust gas regulations, ISG (Idling Stop & Go) and charging control systems are applied to HEVs (Hybrid Electric Vehicle) for the purpose of improving fuel economy. These systems require quick charge/discharge performance at high current. To satisfy this characteristic, improvement of the positive electrode plate is studied to improve the charge/discharge process and performance of AGM(Absorbent Glass Mat) lead-acid batteries applied to ISG automotive systems. The bonding between grid and A.M (Active Material) can be improved by applying the Sand-Blasting method to provide roughness to the surface of the positive grid. When the Sand-Blasting method is applied with conditions of ball speed 1,000 rpm and conveyor speed 5 M/min, ideal bonding is achieved between grid and A.M. The positive plate of each condition is applied to the AGM LAB (Absorbent Glass Mat Lead Acid Battery); then, the performance and ISG life characteristics are tested by the vehicle battery test method. In CCA, which evaluates the starting performance at -18 ℃ and 30 ℃ with high current, the advanced AGM LAB improves about 25 %. At 0 ℃ CA (Charge Acceptance), the initial charging current of the advanced AGM LAB increases about 25 %. Improving the bonding between the grid and A.M. by roughening the grid surface improves the flow of current and lowers the resistance, which is considered to have a significant effect on the high current charging/discharging area. In a Standard of Battery Association of Japan (SBA) S0101 test, after 300 A discharge, the voltage of the advanced AGM LAB with the Sand-Blasting method grid was 0.059 V higher than that of untreated grid. As the cycle progresses, the gap widens to 0.13 V at the point of 10,800 cycles. As the bonding between grid and A.M. increases through the Sand Blasting method, the slope of the discharge voltage declines gradually as the cycle progresses, showing excellent battery life characteristics. It is believed that system will exhibit excellent characteristics in the vehicle environment of the ISG system, in which charge/discharge occurs over a short time.

• The Journal of the Korean dental association
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• v.57 no.5
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• pp.264-268
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• 2019

Objectives: This study aimed to measure the water sorption / solubility of Biodentine, composite resin and glass ionomer cement. Materials and Methods: The materials used in this study were Biodentine(BD), Filtek Z250(FZ) and Ketac Molar(KM). Twenty disc-shaped specimens of each material were prepared of 6mm diameter and 1mm thickness. All specimens were desiccated for 24 hours and weighed(m1). After then, They were immersed in distilled water and stored at $37^{\circ}C$. 1 week later, They were washed with running water, wiped with absorbent paper and weighed(m2). Finally, They were dried for 24 hours and weighed(m3). Water sorption and solubility, net water uptake were calculated. Results: KM and BD showed high water sorption than FZ(P<0.05). KM and BD exhibited similar water sorption(P<0.05). BD exhibited high solubility than KM(P=0.012). BD exhibited high net water uptake than FZ(P=0.008). Conclusion: Biodentine showed higher water sorption, solubility and net water uptake than Filtek Z250 and Ketac Molar. Within limitation of this study, it is not recommended to use Biodentine for permanent restoration.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.296-301
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• 2015

The experiment was performed for in order to remove NOx which is generated in the Ship's engine. it was performed test in order to remove NOx which is generated in the Ship's engine. It was used as the oxidizing agent sodium chlorite. Use the oxidizer is nitrogen monoxide was oxidized to nitrogen dioxide. and was tested pH adjustment to increase the efficiency of oxidizing. An aqueous solution of sodium hydroxide was used for the nitrogen dioxide absorbent. Low concentration of the solution, it showed a high efficiency. improves the absorption efficiency by add additives.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.276-285
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• 2000

Paraquat is a very potent herbicide which causes fatal toxicity when ingested, and there is no specific antidote against it. Human ingestion induces acute renal failure, hepatic dysfunction and progressive respiratory failure with high mortality rate. Clinical investigation and medical treatment were done on two cases of acute renal failure caused by paraquat poisoning admitted to the Department of Internal Medicine, Wonkwang University Oriental Chonju Medical Hospital. We report two cases of patients who survived after acute paraquat intoxication, by means of oriental medicine such as Gamdutang, a typical antidote of toxins, chinese ink as an absorbent and burned powder of Rhei Radix et Rhizoma for laxative and so on, western medicine such as gastric lavage, diuretics and fluid therapy. We suggest more experiments and studies related to such treatment for paraquat poisoning be conducted.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.431-434
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• 2002

This paper reports on the evaluation of weathering resistance, tracking test and salt-fog of various kinds of cycloaliphatic epoxy systems. It was found that UV irradiation induced the loss of hydrophobic level due to the chain scission attack at the surface. It could be seen that samples containing an UV absorbent/antioxidant and a silicone oil additive knave a good performance in weathering ageing, whereas ATH filled ones have high resistance against tracking failure than others. Under salt-fog test, specimens mixed with silicone oil could suppress leakage current development. It was thought that silicone oil mixed into cycloaliphatic epoxy system could lead to lower the surface energy and to retain hydrophobic properties for a long time, which are desirable for outdoor performances.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.45-49
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• 2019

The basalt fiber is expected to become a trend for industrial fibers as they have better properties of heat-resistant, non-combustion, absorbent, soundproof, moistureproof, lightweight, corrosion resistant, and high strength properties. Also, the fiber is found to be non-toxic and harmless to the human body. Therefore, in this study, we analyzed the chemical and mineral compositions of powdered sludge of basalt produced at seven sites on Jeju Island for the development of fire resistance insulating material for a building. The results showed that the basalt stone sludge is made from only sodium calcium aluminum silicate and ferridioside components unlike the basalt rock.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.579-584
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• 1997

A series of ferrocene-containing chelating bidentate nitrogen ligands (1 & 2) and polyazamacrocycles (3 & 4) were prepared in high yields from the reaction of ferrocenecarboxaldehydes with corresponding diamines under various catalytic and stoichiometric reaction conditions. The stoichiometric condensation to form Schiff bases required the presence of MgSO₄in the reaction mixture as a water-absorbent. Employment of cyclic diamines such as 1,2-diaminocyclohexane and p-phenylenediamine in the reaction with 1,1'-ferrocenedicarboxaldehyde resulted in the formation of polymers in stead of the expected macrocycles. All these compounds were characterized by microanalytical and spectroscopic techniques. In one case, the structure of 3a was confirmed by X-ray crystallography.

• Analytical Science and Technology
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• v.30 no.3
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• pp.138-145
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• 2017

Microwave-assisted organic synthesis has gained a remarkable interest over the past years because of its advantages - (i) rapid energy transfer and superheating, (ii) higher yield and rapid reaction, (iii) cleaner reactions. Ionic liquids are well known for their unique properties such as negligible vapor pressure and high thermal stability. With these properties, ionic liquids have gained increasing attention as green, multi-use reaction media. Recently, ionic liquids have been applied as reaction media for biocatalysis. Lipase-catalyzed reactions in ionic liquids provide high activity and yield compared to conventional organic solvents or solvent free system. Since polar molecules are generally good absorbent to microwave radiation, ionic liquids were investigated as reaction media to improve activity and productivity. In this study, therefore, the effect of microwave irradiation in ionic liquids was investigated on lipase catalyzed reactions such as benzyl acetate synthesis and caffeic acid phenethyl ester synthesis. Comparing to conventional heating, microwave heating showed almost the same final conversion but increased initial reaction rate (3.03 mM/min) compared to 2.11 mM/min in conventional heating at $50^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.88.1-88.1
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• 2015

In recent printed electronics technology, Photo-Sintering, a technique for sintering materials using a light source, has attracted attention as an alternative to time-consuming high-temperature thermal processes. The key principle of this technique is the selective heating of a strongly absorbent thin film, while preventing the heating of the transparent substrate by the light source. Many recent studies have used a flash lamp as the light source, and investigated the material-dependent effect of the width or intensity of the pulsed light. However, the flash lamp for sintering is not suitable for industry yet, because of needing too high power to sinter for a large scale. In energy-saving and large-scale sintering, LED technologies would be very useful in the near future. In this work, we investigated a sintering process for silver nanoparticles using UV-LED array. Silver nanoparticles in ink were inkjet-printed on a $1{\times}1cm$ area of a PET film and photo-sintered by 365 nm UV-LED module. A sheet resistance value as low as $72.6m{\Omega}/sq$ (2.3 - 4.5 times that of bulk silver) was obtained from the UV-LED sintering at 300 mW/cm2 for 50 min.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.97-101
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• 2014

With the increase in global air travel, aircraft noise has become a major public issue. In modern aircraft engines, only a small proportion of the air that passes through the whole engine actually goes through the core of the engine, the rest passes around it down the bypass duct. A successful method of reducing noise further, even in ultra-high bypass ratio engines, is to absorb the sound created within the engine. Acoustically absorbent material or acoustic liners have desirable acoustic attenuation properties and thus are commonly used to reduce noise in jet engines. The liners typically are placed upstream and downstream of the rotors (fans) to absorb sound before it propagates out of the inlet and exhaust ducts. Noise attenuation can be dramatically improved by increasing the area over which a noise reducing material is applied and by placing the material closer to the noise source. In this paper we will briefly discuss acoustic liner applications in modern turbofan engines.