• Journal of Soil and Groundwater Environment
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• v.17 no.1
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• pp.8-12
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• 2012

This study is maintains the condition of high temperature (above $600^{\circ}C$) within a short time using on microwave and high temperature heating elements. And removal characteristics according to changes in soil moisture, microwave power and temperature through the decomposition of the contaminated soil by oil. The difficulty resolvability material was sort of lubricating oil having long carbocyclic (C18-C50) and TPH removal rate reached 85.2% at 6 kW and $700^{\circ}C$ and thus the contaminant was removed 1,788 mg/kg within a process time of 40 minutes. In the case of light oil, gasoline contaminated soil, the removal amount showed 567 mg/kg and the treatment rate reached 98.4% at 6 kW, $500^{\circ}C$ and 20 minute. In the case of non-resolvability reached TPH concentrations on 2,000 mg/kg of worrisome level of soil contamination in the 3 zones at 6 kW, $700^{\circ}C$ and 30 minute. At the time, showed up processing costs 8,173 won per ton.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.55-60
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• 2017

The supercritical $CO_2$ (sc-$CO_2$) mixture and the sc-$CO_2$-based Photoresist(PR) stripping(SCPS) process were applied to the removal of the post etch/ash PR residue on aluminum patterned wafers and the results were observed by scanning of electron microscope(SEM). In the case of MDII wafers, the carbonized PR was able to be effectively removed without pre-stripping by oxygen plasma ashing by using sc-$CO_2$ mixture containing the optimum formulated additives at the proper pressure and temperature, and the same result was also able to be obtained in the case of HDII wafer. It was found that the efficiency of SCPS of ion implanted wafer improved as the temperature of SCPS was high, so a very large amount of MEA in the sc-$CO_2$ mixture could be reduced if the temperature could be increased at condition that a process permits, and the ion implanted photoresist(IIP) on the wafer was able to be removed completely without pre-treatment of plasma ashing by using the only 1 step SCPS process. By using SCPS process, PR polymers formed on sidewalls of metal conductive layers such as aluminum films, titanium and titanium nitride films by dry etching and ashing processes were removed effectively with the minimization of the corrosion of the metal conductive layers.

• International Journal of Highway Engineering
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• v.16 no.5
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• pp.49-58
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• 2014

PURPOSES : In areas of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide ($TiO_2$), that is one of photocatalytic reaction material, is very efficient for removing NOx. The NOx removing mechanism of $TiO_2$ is the reaction of solar photocatalysis. Therefore, $TiO_2$ in road structure concrete need to be contacted with ultraviolet rays (UV) to be activated. In general, $TiO_2$ concretes are produced by replacement of $TiO_2$ as a part of concrete binder. However, considerable portion of $TiO_2$ in concrete cannot contact with the pollutant in the air and UV. Therefore, $TiO_2$ penetration method using the surface penetration agents is attempted as an alternative in order to locate $TiO_2$ to the surface of concrete structure. METHODS : This study aimed to evaluate the NOx removal efficiency of photocatalytic concrete due to various $TiO_2$ application method such as mix with $TiO_2$, surface spray($TiO_2$ penetration method) on hardened concrete and fresh concrete using surface penetration agents. The NOx removal efficiency of $TiO_2$ concrete was confirmed by NOx Analyzing System based on the specification of ISO 22197-1. RESULTS : The NOx removal efficiency of mix with $TiO_2$ increased from 11 to 25% with increasing of replacement ratio from 3 to 7%. In case of surface spray on hardened concrete, the NOx removal efficiency was about 50% due to application amount of $TiO_2$ with surface penetration agents as 300, 500 and 700g/m2. The NOx removal efficiency of surface spray on fresh concrete due to all experimental conditions, on the other hand, which was very low within 10%. CONCLUSIONS : It was known that the $TiO_2$ penetration method as surface spray on hardened concrete was a good alternative in order to remove the NOx gases for concrete road structures.

• Resources Recycling
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• v.23 no.5
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• pp.55-61
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• 2014

Froth flotation was performed to study the effect of phosphate addition in the experiment to remove As from tailing of Sang-dong Mine. The experiment without Trisodium phosphate (T.S.P) showed that the removal rate of As was 88.7% and weight-ratio of floating material was 2.52%. By contrast, the experiment with T.S.P showed that the removal rate of As was 92.74% and weight-ratio of floating material was 2.26%. In flotation without T.S.P, the average particle size of float material was 19.34 um and the amount less than 10um was 40.2%. On the other hand, in flotation with T.S.P the average particle size of float material was 176.8 um and the amount less than 10um was 6.5%. The result of X.R.F analysis presented that contents of $SiO_2$ was 42.74% in float material of the experiment without T.S.P. In contrast, contents of $SiO_2$ was 29.56% in float material of the experiment with T.S.P.

• Polymer(Korea)
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• v.30 no.3
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• pp.210-216
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• 2006

To use the filter materials for selective removal of carbonyl compounds in cigarette mainstream smoke, hydrazine such as 2,4-dinitrophenylhydrazine (2,4-DNPH) and dansylhydrazine (DAH) impregnated adsorbents were prepared with perchloric acid or phosphoric acid as an accelerator in hydrazone formation reaction. Changes of molecular structure and morphology of adsorbents in various of impregnator were investigated by FTIR/ATR and SEM. Impregnation amount caused by reaction time, acid type and impregnation reagent, and the adsorption properties of carbonyl compounds in cigarette mainstream smoke were studied. Amounts of impregnation increased with increasing reaction time. The removal amount for vapor phase carbonyl compounds by 2,4-DNPH impregnated adsorbent was higher than that of dansylhydrazine impregnated adsorbent. The selectivity of 2,4-DNPH impregnated polyacrylic type adsorbent was superior to those of other adsorbents. This result indicates that the 2,4-DNPH impregnated polyacrylic adsorbent is applicable to cigarette filter material because of its fast reactivity and porosity.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.536-539
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• 2000

A simple and effective method has been developed for the immobilization of the cell on polyurethane foam. Two types of commercially available polyurethane foam and Hydro-filt were tested. The ultimate purpose of the process is to produce low-cost materials for hydrogen sulfide removal which are being increasingly used for industrial application. Effect of several parameters were studied on the cell loading. These parameters were type, size, and amount of polyurethane foam. MC-70 was the best immobilization material of three type of carriers, and optical particle size was $5{\sim}8mm$ and amount of polyurethane foam was 8g/L.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.1-7
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• 1995

Strontium selective chromatographic material $(Sr-Spec^{TM})$ was investigated for separation of radiostrontium from environmental soil and water sample. This chromatographic material has great capacity of binding of strontium ion in nitric acid media, and has selectivity to permit the separation of stontium from bulk amount of calcium. But the extraction of strontium was reduced by the other interfering ions such as K and Ba. So, in order to apply this material to the soil sample, prior removal treatment of K and Ba was needed. But the Sr-Spec material could provides simple and effective methods for the separation and removal of radiostrontium from liquid sample.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.637-642
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• 2005

The focus of this study was to examine the phosphorus removal characteristic by zirconium mesoporous structured material synthesized on various conditions. The zirconium sulfate-surfactant mesoporous structured material(ZS) was synthesized by hydro-thermal synthesis. The material has regular hexagonal array of surfactant micelles and sulfate ion ($HSO_4{^-}$). We confirmed that sulfate ion in zirconium mesoporous structured material can be ion-exchanged with phosphate ion ($H_2PO_4{^-}$) in phosphoric acid solution. On the X-ray diffraction (XRD) pattern of ZS, three peaks which shows the important characteristics of hexagonal crystal lattice were observed at (100), (110) and (200). The transmission electron micrograph (TEM) show high crystallization with pore size about $47{\AA}$. The maximum adsorption capacity of ZS was as great as 3.2 mmol-P/g-ZS. From the adsorption isotherm, correlation coefficients were higher for the Langmuir isotherm than the Freundlich isotherm. With the respect of chain length of surfactant, the adsorption capacity for phosphate synthesized with C12 was higher than C16 and C18. The highest amount of adsorbed phosphate on ZS was observed at the surfactant-to-zirconium molar ratio of 0.5 to 1.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.443-444
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• 2002

The uniformity of field oxide is critical to isolation property of device in STI, so the control of field oxide thickness in STI-CMP becomes enormously important. The loss of field oxide in shallow trench isolation comes mainly from dishing and erosion in STI-CMP. In this paper, the effect of slurries on the dishing was investigated with both blanket and patterned wafers were selected to measure the removal rate, selectivity and dishing amount. Dishing was a strong function of pattern spacing and types of slurries. Dishing was significantly decreased with decreasing pattern spacing for both slurries. Significantly lower dishing with ceria based slurry than with silica based slurry were achieved when narrow pattern spacing were used. Possible dishing mechanism with two different slurries were discussed based on the observed experimental results.

• Journal of Chest Surgery
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• v.33 no.9
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• pp.738-743
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• 2000

Background: Video-assisted thoracic surgery(VATS) is being used as a therapeutic modality in many diseases in which thoracotomy has been used. We studied that the VATS can substitute the thoracotomy in benign esophageal disease. Material and Method: Group I (n=18) underwent video-assisted thoracic surgery, and group II(n=19) thoracotomy. Group I includes 14 leiomyomas and 4 achalasias. Group II includes 16 leiomyomas and 3 achalasias. Operative technique is enucleation in the leiomyoma and modified Heller's myotomy in the achalasia. Analyzing factors of operation-efficacy are anesthetic time, operation time, hospital stay, chest tube drainage amount and chest tube removal day. The degree of the postoperative pain is assessed by the frequency of opioid analgesics injection. Result: There was no death in both groups. There were 5 complications in the group I and 2 in the group II. Prolonged pleural effusion and restenosis of achalasia occurred to 1 patient in each group. In the group I, there were 1 temporaty vocal cord palsy and 2 mucosal tear leading to thoracotomy. There were no differences in anesthesia time, operation time, hospital stay, total chest tube drainage amount, chest tube removal day and frequency of opioid analgesics injection. The amount of the chest tube drainage at POD 1 day was significantly lower in group I(155.6$\pm$77.8cc) than in group II(572.8$\pm$280.1cc)(p<0.05). Conclusion: The results of our data showed that video-assisted thoracic surgery for benign esophageal disease is as effective as thoracotomy and in addition, cosmetic effect is much better. We concluded VATS may be a substitute for thoracotomy in benign esophageal disease.