• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.61-66
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• 2012

Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.72-87
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• 2022

For the sustainable development and conservation of the national land, planned development and efficient environmental conservation must be accompanied. To this end, it is possible to induce development and conservation to harmonize by deriving factors affecting development through analysis of previously developed areas and applying appropriate management measures to areas with high development pressure. In this study, the relationship between the area where the land cover changed from forest to urbanization and various social, geographical, and restrictive factors was implemented in a regression formula through logistic regression analysis, and potential development sites were analyzed for Yongin City. The factor that has the greatest impact on the analysis of potential development area is the restrict factors such as Green Belt and protected areas, and the factor with the least impact is the population density. About 148km²(52%) of Yongin-si's forests were analyzed as potential development area. Among the potential development sites, the area with excellent environmental value as a protected area and 1st grade on the Environment Conservation Value Assessment Map was derived as about 13km². Protected areas with high development potential were riparian buffer zone and special measurement area, and areas with excellent natural scenery and river were preferred as development areas. Protected areas allow certain actions to protect individual property rights. However, there is no clear permit criteria, and the environmental impact of permits is not understood. This is identified as a factor that prevents protected areas from functioning properly. Therefore, it needs to be managed through clear exception permit criteria and environmental impact monitoring.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.98-102
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• 1995

Popped popcorn generally have a regular popping direction and typical shape. But the reason and mechanism are not clear yet. This experiment was carried out to investigate the shape moulding factor of popped popcorn. Pericarp thickness of tip-cap section of kernels is slightly thicker than that of top section and this fact provides the important information to the reason. Popping starts when the moisture pressure of heated popcorn is increased and reaches at the critical pressure. Therefore, in the same moisture pressure conditions, top sections are bursted first because their pericarp section is thinner than that of tip-cap section. At the very moment tip-cap sections pull down the top sections of peri carp as bi-metal does. So kernels which removed tip-cap section showed the irregular popping shape because they lost the tip-cap pericarp function. How-ever, kernels which removed embryo showed the typical popping shape but their popping volume was small due to emition and shortage of critical moisture pressure. But kernels which removed the whole pericarp and top pericarp were not popped at all because moisture was entirely emitting out of kernels. These results suggest that the shape moulding factor of popped popcorn is the pericarp thickness differences between the top and tip-cap section of kernels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.293-300
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• 2006

Domestic laws such as Korea Marine Pollution Prevention Law (KMPPL) which has been mae and amended according to the conclusions and amendments of various international conventions for the prevention a marine pollution such as MARPOL 73/78 were reviewed and compared with the major contents of the relevant international conventions. Alternative measures for legislating new laws or amending existing laws such as KMPPL for the acceptance of major contents of existing international conventions were proposed. Annex VI of MARPOL 73/78 into which the regulations for the prevention of air pollution from ship have been adopted has been recently accepted in KMPPL which should be applied to ships which are the moving sources of air pollution at sea rather tlnn in Korea Air Environment Conservation Law which should be applied to automobiles and industrial installations in land. The major contents of LC 72/95 have been accepted in KMPPL However, a few of substances requiring special care in Annex II of 72LC, a few of items in characteristics and composition for the matter in relation to criteria governing the issue of permits for the dumping of matter at sea in Annex III of 72LC, and a few of items in wastes or other matter that may be considered for dumping in Annex I of 96 Protocol have not been accepted in KMPPL yet. The major contents of OPRC 90 have been accepted in KMPPL. However, oil pollution emergency plans for sea ports and oil handling facilities, and national contingency plan for preparedness and response have not been accepted in KMPPL yet. The waste oil related articles if Basel Convention, which shall regulate and prohibit transboundary movement of hazardous waste, should be accepted in KMPPL in order to prevent the transfer if scrap-purpose tanker ships containing oil/water mixtures and chemicals remained on beard from advanced countries to developing and/or underdeveloped countries. International Convention for the Control if Harmful Anti-Fouling Systems on the Ships should be accepted in KMPPL rather tlnn in Korea Noxious Chemicals Management Law. International Convention for Ship's Ballast Water/Sediment Management should be accepted in KMPPL or by a new law in order to prevent domestic marine ecosystem and costal environment from the invasion of harmful exotic species through the discharge of ship's ballast water.

• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.14-23
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• 2002

Background: The opitmal ventilator setting during partial liquid ventilation(PLV) is controversial. This study investigated the effects of various gas exchange parameters during PLV in normal rabbit lungs in order to aid in the development of an optimal ventilator setting during PLV. Methods: Seven New-Zealand white rabbits were ventilated in pressure-controlled mode with the following settings; tidal volume($V_T$) 8 mL/kg, positive end-expiratory pressure(PEEP) 4 $cmH_2O$, inspiratory-to-expiratory ratio(I:E ratio) 1:2, fraction of inspired oxygen($F_TO_2$) 1.0. The respiration rate(RR) was adjusted to keep $PaCO_2$ between 35~45 mmHg. The ventilator settings were changed every 30 min in the following sequence : (1) Baseline, as the basal ventilator setting, (2) Inverse ratio, I:E ratio 2:1, (3) high PEEP, adjust PEEP to achieve the same mean inspiratory pressure (MIP) as in the inverse ratio, (4) High $V_T$, $V_T$ 15 mL/kg, (5) high RR, the same minute ventilation (MV) as in the High $V_T$. Subsequently, the same protocol was repeated after instilling 18 mL/kg of perfluorodecalin for PLV. The parameters of gas exchange, lung mechanics, and hemodynamics were examined. Results: (1) The gas ventilation(GV) group showed no significant changes in the $PaO_2$ at all phases. The $PaCO_2$ was lower and the pH was higher at the high $V_T$ and high RR phases(p<0.05). No significant changes in the lung mechanics and hemodynamics parameters were observed. (2) The baseline $PaO_2$ for the PLV was $312{\pm}$ mmHg. This was significantly lower when decreased compared to the baseline $PaO_2$ for GV which was $504{\pm}81$ mmHg(p=0.001). During PLV, the $PaO_2$, was significantly higher at the high PEEP($452{\pm}38$ mmHg) and high $V_T$ ($461{\pm}53$ mmHg) phases compared with the baseline phase. However, it did not change significantly during the inverse I:E ratio or the high RR phases. (3) The $PaCO_2$ was significantly lower at high $V_T$ and RR phases for both the GV and PLV. During the PLV, $PaCO_2$ were significantly higher compared to the GV (p<0.05). (4) There were no important or significant changes in of baseline and high RR phases lung mechanics and hemodynamics parameters during the PLV. Conclusion: During PLV in the normal lung, adequate $V_T$ and PEEP are important for optimal oxygenation.

• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.879-890
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• 2006

Background: The dysfunction of multiple organs is found to be caused by reactive oxygen species as a major modulator of microvascular injury after hemorrhagic shock. Hemorrhagic shock, one of many causes inducing acute lung injury, is associated with increase in alveolocapillary permeability and characterized by edema, neutrophil infiltration, and hemorrhage in the interstitial and alveolar space. Aggressive and rapid fluid resuscitation potentially might increased the risk of pulmonary dysfunction by the interstitial edema. Therefore, in order to improve the pulmonary dysfunction induced by hemorrhagic shock, the present study was attempted to investigate how to reduce the inflammatory responses and edema in lung. Material and Method: Male Sprague-Dawley rats, weight 300 to 350 gm were anesthetized with ketamine(7 mg/kg) intramuscular Hemorrhagic Shock(HS) was induced by withdrawal of 3 mL/100 g over 10 min. through right jugular vein. Mean arterial pressure was then maintained at $35{\sim}40$ mmHg by further blood withdrawal. At 60 min. after HS, the shed blood and Ringer's solution or 5% albumin was infused to restore mean carotid arterial pressure over 80 mmHg. Rats were divided into three groups according to rectal temperature level($37^{\circ}C$[normothermia] vs $33^{\circ}C$[mild hypothermia]) and resuscitation fluid(lactate Ringer's solution vs 5% albumin solution). Group I consisted of rats with the normothermia and lactate Ringer's solution infusion. Group II consisted of rats with the systemic hypothermia and lactate Ringer's solution infusion. Group III consisted of rats with the systemic hypothermia and 5% albumin solution infusion. Hemodynamic parameters(heart rate, mean carotid arterial pressure), metabolism, and pulmonary tissue damage were observed for 4 hours. Result: In all experimental groups including 6 rats in group I, totally 26 rats were alive in 3rd stage. However, bleeding volume of group I in first stage was $3.2{\pm}0.5$ mL/100 g less than those of group II($3.9{\pm}0.8$ mL/100 g) and group III($4.1{\pm}0.7$ mL/100 g). Fluid volume infused in 2nd stage was $28.6{\pm}6.0$ mL(group I), $20.6{\pm}4.0$ mL(group II) and $14.7{\pm}2.7$ mL(group III), retrospectively in which there was statistically a significance between all groups(p<0.05). Plasma potassium level was markedly elevated in comparison with other groups(II and III), whereas glucose level was obviously reduced in 2nd stage of group I. Level of interleukine-8 in group I was obviously higher than that of group II or III(p<0.05). They were $1.834{\pm}437$ pg/mL(group I), $1,006{\pm}532$ pg/mL(group II), and $764{\pm}302$ pg/mL(group III), retrospectively. In histologic score, the score of group III($1.6{\pm}0.6$) was significantly lower than that of group I($2.8{\pm}1.2$)(p<0.05). Conclusion: In pressure-controlled hemorrhagic shock model, it is suggested that hypothermia might inhibit the direct damage of ischemic tissue through reduction of basic metabolic rate in shock state compared to normothermia. It seems that hypothermia should be benefit to recovery pulmonary function by reducing replaced fluid volume, inhibiting anti-inflammatory agent(IL-8) and leukocyte infiltration in state of ischemia-reperfusion injury. However, if is considered that other changes in pulmonary damage and inflammatory responses might induce by not only kinds of fluid solutions but also hypothermia, and that the detailed evaluation should be study.