• 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 Technologic Dentistry
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• v.21 no.1
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• pp.27-41
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• 1999

The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-30Pd-10Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at 350-$550^{\circ}C$ Age-hardening characteristic of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, energy dispersed spectra and electron probe microanalysis. Principal results are as follows ; Maximum hardening occured in two co-phases of ${\alpha}_2$ + PdCu In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase($L1_o$ type) and an Ag-rich ${\alpha}_2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu redered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}{\to}{\alpha}_1+PdCu{\to}{\alpha}_2+PdCu$ at Pd/Cu = 3 Pd element of Ag-Pd-Cu alloy is more effective dental alloy on anti-corrosion and is suitable to isothermal ageing at $450^{\circ}C$.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.21-35
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• 1997

The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy is cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-20Pd-20Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electic furace and centrifugal casting machine in Ar atmoshpere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age-hardening characteristics of the small Au-containing Ag-pPd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, emergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, I. e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the Llo type face centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affedted by the Cu concentration. In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase(L1o type) and an Agrich ${\alpha}2$ phase occurred and a discontiunous precipitation occurred at the grain boundary. Form the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}\to{\alpha}+{\alpha}2+PdCu\to{\alpha}1+{\alpha}2+PdCu$ at Pd/Cu = 1 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.173-205
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• 2008

Space debris have frequently caused damage to space objects like satellites in orbits and sometimes have fallen on the earth. Such increase in space debris will lead to the high possibility of threatening space activities of mankind. However, it is not so easy for the damage caused both by identified and by unidentified space debris to be recovered since in the regime of the current international law, there is no legislation of prescribing the damage done by space debris. For overcoming the limitation it seems desirable that either the Liability Convention should partly be amended or new international law regime should be established. For instance, 'space debris' should be included in the new definition of 'space object' and the range of launching should also be defined clearly by making the concept of 'launching' somewhat more specified. Moreover, the subject of international liability for damage caused by space debris should be divided into two classes: the subject before and after registration. While in case of before-registration launch states should be held liable for any damage jointly or individually, in case of after-registration 'the state of registry' or 'owner' of the space debris should be. In the event of damage being caused elsewhere than on the surface of the earth to a space object of other State, 'fault-based liability' is currently applied. But it needs to be changed into 'absolutely liability'. In this paper, 'Liability Pool', 'Insurance', 'Market-Share Liability' are presented as aid devices of the damages resulting from unidentified space debris. They should be defined through the amendment of the Liability Convention or another international treaty. Some day there comes a time when our country shall possess many of the astronomical price of satellites. It means that we can't be free from the damage by the increasing number of space debris. Provided that our satellites are damaged by such space debris, it will do the satellites damage and cause impaired functioning or troubles in operation. As a result, if we are not paid for the damage by space debris, we will be confronted with tremendous economic loss because it is necessarily connected with the excess burden of taxation. Thus, an international agreement regarding the measures of the compensation for space debris damage must be made very soon.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.785-794
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• 1998

Background: Chemical pleurodesis is a widely used method for the control of symptomatic and recurrent malignant pleural effusions. Talc has been accepted to be the most effective sclerosing agent for chemical pleurodesis. This study was undertaken to evaluate the usefulness of talc pleurodesis via video-assisted thoracoscopic surgery (VATS) in treatment of malignant pleural effusions. Methods : A retrospective analysis of the medical records and radiographic findings was performed. The success of the procedure was defined as daily pleural fluid drainage below 100ml within 1 week after pleurodesis and complete expansion of the lung on simple chest radiograph. Recurrence was defined as reaccumulation of pleural fluid on follow-up chest radiographs, and complete response as no fluid accumulation on follow-up chest radiographs. Results: Between October 1994 and August 1996, talc pleurodesis via VATS was performed in 35 patients. Duration of follow-up ranged from 5 days to 828 days(median 79days). The initial success rate of procedure was 88.6%(31 of 35 cases). Complete responses were observed in 92.8% at 30 days, 75.7% at 90 days and 64.9% at 180 days. Postoperative complications were fever (54.3%), subcutaneous emphysema(11.4%), reexpansion pulmonary edema(2.9%) and respiratory failure(5.7%). But procedure related mortality or respiratory failure was not found. Conclusion: Talc pleurodesis via VATS is a safe and effective method for the control of symptomatic malignant pleural effusions.

• Tuberculosis and Respiratory Diseases
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• v.49 no.5
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• pp.614-623
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• 2000

Background : Diffuse alveolar hemorrhage (DAH) is rare but often fatal. To determine the clinical manifestations of DAH, its etiology, clinical course and prognosis were studied. Method : A retrospective analysis was performed in 21 patients that were diagnosed as DAH. Diagnosis of DAH was based on the presence of the "classical triad" of hemoptysis, anemia, and rapidly progressive infiltrates on chest X-ray and a finding of bronchoalveolar lavage or lung biopsy. Results : Thirteen patients (61.9%) had collagen vascular diseases (CVDs) as underlying disease and 10 patients had systemic lupus erythematosus. Females were more prevalent in CVD than in non-collagen vascular disease (NCVD). Otherwise, there were no significant differences between the two groups in terms of clinical manifestations. Dyspnea (95.2%), cough (76.2%), hemoptysis (61.9%), and fever (33.0%) were frequent symptoms. The initial creatinine level was higher in CVD than in NCVD ($3.27{\pm}3.15$ mg/dl vs. $1.19{\pm}0.94$ mg/dl, p=0.030). The corresponding drop in hemoglobin level was $2.69{\pm}1.26$ g/dl. Maximal drop in hemoglobin preceded the progression of infiltrates on the chest radiograph by $1.38{\pm}4.22$ days. The mortality rate was higher in the patients with NCVD than in those with CVD (50.0% vs. 23.1%). Conclusion : The DAH can occur not only in patients with CVD but also in those with NCVD. Higher creatinine level CVD in patients is associated with renal involvement in conjunction with DAH. The maximal drop in hemoglobin preceeding the progression of infiltrates on the chest radiograph suggests that the drop in hemoglobin is important for diagnosing DAH.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.195-203
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• 2013

In this study, antioxidative effects of the extracts of different species and flowering periods of Inula britannica were investigated. According to the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of the extracts, The I. britannica var. chinensis flower extract (500 ${\mu}g/mL$) was measured in a 79.89% free radical scavenging activity, but the flower extracts of similar species (I. britannica var. linariaefolia Regel, I. britannica var. ramosa, I. salicina var. asiatica) did not show any effect on the free radical scavenging activity. The effects of the free radical scavenging activity of I. britannica var. chinensis flower extracts were exhibited in the order of full bloom (93.68%), bud (43.28%), and fallen blossom (14.11%). Next, we established optimum condition of extract solvent, temperature, extraction time. The extract from ethanol at $60^{\circ}C$ showed the most free radical scavenging activity among other conditions and extraction time not relevant in free radical scavenging activity. The protective effects of the extract of I. britannica var. chinensis flower on the photohemolysis of human erythrocytes by using rose bengal were increased in a concentration-dependent manner (5 ~ 50 ${\mu}g/mL$). In particular, the extract in 50 ${\mu}g/mL$ concentration exhibited better protective activity (${\tau}_{50}$ = 116.1 min) than (+)-${\alpha}$-tocopherol (${\tau}_{50}$ = 73.44 min), which is a known lipophilic antioxidant. Principle component of I. britannica var. chinensis flower was identified as quercetin of flavonoids by high-performance liquid chromatography (HPLC). These results indicate that the extract of I. britannica var. chinensis flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and $^1O_2$, and protect cellular membranes against ROS. It is concluded that the antioxidative effects of the extract of I. britannica var. chinensis flower could be applicable to functional cosmetics.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.287-294
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• 2014

The purpose of this study is to use basic data of dental hygiene curriculum with a new technique called motivational interviewing of communication skill to demonstrate the effectiveness of the method of oral health care. In this study, we performed oral health care program that has been made in dental hygiene department to university students. It was assigned to the control group and 66 and 32 experimental group based on the date of the first visit time. It conducted motivational interviewing of a total of three times in the experimental group. The analytical results of the measurements obtained in the oral examination and questionnaires. The results were as follows: The experimental group measured value was reduced after the intervention compared to before the PSR to evaluate the state of periodontal, gingival index, calculus index, plaque control record (PCR; O'Leary plaque index), simple plaque scor of Quantitative Light Induced Fluorescnece Digital measurement value (p<0.05). Experimental group decreased more and more the result of changes in the reduction of the average of the PCR. But control group was reduced to 3 weeks and increased back to the middle 16 weeks. There was also support interaction between the measurement point and the groups (p<0.05). Re-visit adherence of fit, 12.1% in the control group, the experimental group was 43.7% in the period of participation in the oral health care program. Thus, visit adherence of the experimental group was higher. In this study, a group that has motivational interviewing, It was able to confirm the improvement of oral health state. Discussion of the motivational interviewing can be applied to oral health care program.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.113-118
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• 2010

Due to diverse soil-forming environments and different purposes of the soil classification, numerous soil classification systems have been developed worldwide. The World Reference Base for Soil Resources (WRB) and the Soil Taxonomy of the United States are well-known in Korea. However, the German Soil Systematics based on somewhat different principles from the two former systems is little-known. The objective of this paper is therefore to give a short overview of the principles of the German Soil Systematics. The German Soil Systematics consists of a six-level hierarchical structure which comprises soil divisions, soil classes, soil types, soil subtypes, soil varieties, and soil subvarieties. Soils in Germany are firstly classified into one of four soil divisions according to the soil moist regime: terrestrial soils, semi-terrestrial soils, semi-subhydric/subhydric soils, and peats. Terrestrial soils are subdivided into 13 soil classes based on the stage of soil formation and the horizon differentiation. Semi-terrestrial soils are differentiated into four classes regarding the source of soil moist: groundwater, freshwater, saltwater, and seaside. Semi-subhydric/subhydric soils are subdivided into two classes: semi-subhydric and subhydric soils. Peats are classified into two classes of natural and anthropogenic origins. Classes can be compared to orders of the U.S. Taxonomy. Classes are subdivided into 29 soil types with regard to soil forming-processes for terrestrial soils, into 17 types with regard to the soil formation for semi-terrestrial soils, into five types with regard to the content of organic matter for semi-subhydric/subhydric soils, and also into five types with regard to peat-forming processes for peats. The soil mapping units in Germany are types, which can be additionally subdivided into ca. 220 subtypes, several thousands of varieties and subvarieties using detailed nuances of morphologic features of soil profile. Soil types can be compared to great groups of the U.S. Taxonomy.

• Food Science and Preservation
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• v.15 no.1
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• pp.49-57
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• 2008

This study was conducted to develop an optimal composite recipe for a cookie including yam powder that would be attractive to all age groups. Wheat flour was partially substituted by yam powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making cookies, respectively with each 5 level of yam powder $(X_1)$, Sugar$(X_2)$, butter$(X_3)$, by C.C.D (Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM (Response Surface Methodology). Sensory items showed very significant values in color, softness, overall quality (p<0.01), flavor (p<0.05) and those of instrumental analysis showed significant values in lightness, redness (p<0.05), spread ratio, hardness (p<0.01). Also sensory optimal ratio of yam cookie was calculated at yam powder 37.35 g, sugar 50.75 g, butter 78.40 g and it was revealed that the factors of influencing yam cookie aptitude were in older of yam powder, butter, sugar.