• Title/Summary/Keyword: Contaminated surface

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The Endotoxin Assay of Contaminated Titanium Implants following Various Techniques of Detoxification (오염된 임프란트 표면의 해독 방법에 따른 내독소 제거 효과에 관한 연구)

  • Park, Joong-Hee;Lim, Sung-Bin
    • Journal of Periodontal and Implant Science
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    • v.34 no.1
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    • pp.71-81
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    • 2004
  • Peri-implantitis could be the result of biomechanical and occlusal overload as well as microbiologic invasion. The dental implant may be more susceptible to dental plaque than the natural tooth, as the predictability of a stable soft tissue attachment complex has not yet been confirmed. With the development of peri-implantitis, the implant surface would be exposed to the oral environment and becomes coated with bacteria. The objective of therapy for this condition is to regain integration of the implant with bone. Since fibroblast adherence to surfaces is impeded by endotoxin, it would seem that decontamination would be desirable to obtain maximum osseointegration. The purpose of this study was to determine whether various chemotherapeutic and mechanical treatments(distilled water, air-powder abrasive, hypersaturated citric acid, tetracycline) can detoxify contaminated titanium implant surface by means of kinetic LAL test. Experimental rough surface titanium disks were fabricated. All of them were divided into two groups(A.a group and P.g group) and each contaminated by A. actinomycetemcomitans and P. gingivalis suspension. Contaminated disks were treated with distilled water, air-powder abrasive, citric acid and tetracycline, and then all disks were placed into LPS-free water for elution. The results were as follows : 1. In A.a group, LPS elute level of all test groups were significantly lower than control group(p<0.05). 2. In A.a group, LPS elute level of test 2, test 3 and test4 groups were significantly lower than that of control group(p<0.05). But, among the test 2, test 3, test4 groups, the significant differences were not detected. 3. In P.g group, LPS elute level of test 2, test 3 and test 4 groups were lower than that of control group(p<0.05). But, among the test groups, the significant differences were not detected. From the result of this study, it would be concluded that air-powder abrasive, hypersaturated citric acid and tetracycline treatments may be effective at reducing endotoxin level on rough titanium implant surfaces, and can be clinically used. But the treatments in peri-implantitis differentially impact osseointegration making one method clinically superior. To gain this knowledges, further molecular biologic and histopathologic studies should be developed.

Effect of Interfacial Properties on the Detergency in Dishwashing Agent Composition (식기용 세정제 조성에 있어서 계면물성이 세정력에 미치는 영향)

  • Oh, Hyun-Joo;Lim, Hyo-Seon;Kim, Young-Ho
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.193-199
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    • 2020
  • The effects of the composition of the dishwashing detergent on interfaces of the oil (O) and the aqueous (W) solution in addition to the cleaning effects of interfacial properties were investigated. Also, the cleaning power of the oil contaminated on the surface of the dish according to each composition and the residuals of the contaminants and the cleaning agent after the washing rinses were evaluated. The removal of contaminated oil on the solid (S) surface in the composition of the cleaning agents used in this study was strongly related to the interfacial properties between the W/O/S, and was particularly dependent on the forward and backward dynamic contact angles. When both contact angles were low at the same time, the permeability of the cleaning solution was so high that the contaminated oil showed a high removal effect. The smaller the interfacial tension of O/W was, the better emulsification of the contaminated oil, the higher the interfacial tension, and the poorer emulsification were achieved. However, the emulsification effect did not significantly affect the cleaning power. In particular, in the case of the cleaner having low interfacial tension, the cleaning material remained on the surface of the solid after washing.

The application of rapid SIMS analysis for the identification of surface contamination in TFT-LCD manufacturing

  • Liou, Been-Chih;Chou, Yi-Hung;Chen, Chien-Chih;Eccles, John A.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.665-668
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    • 2006
  • Sodium is a serious contamination in LTPS TFT process. It causes the abnormal characteristics of TFT in operation. Contaminated areas can be seen in SEM images, but EDX measurements do not have adequate sensitivity to confirm the presence of superficial sodium residues. We employed SIMS as a fast analysis method to map the non-uniform distribution of sodium on the surface. SIMS can also indicate the thickness of the contamination.

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Investigation of Nanoparticle Generation during Surface Decontamination by Low-Energy-Fluence Laser Ablation (저에너지 플루언스(fluence) 레이저 어블레이션(ablation)을 통한 표면오염제거과정에서의 나노입자의 생성에 관한 연구)

  • Lee, Doh-Won;Cheng, Meng-Dawn
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.199-199
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    • 2003
  • During the cleanup of US Department of energy facilities, contaminated materials, toxic and hazardous radionuclides (e.g., Th, Cs, and U) and heavy metals (e.g., Cr, Hg, Pb, and Ni)-laden ultrafine particles are generated. The size of the particles is up to about 200 nm. Understanding of the production of these nanometer size particles is critical in determining the surface cleaning efficiently. (omitted)

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A Study on the Treatment of Petroleum-Contaminated Soils Using Hydrogen Peroxide (석유로 오염된 토양의 과수를 이용한 처리에 관한 연구)

  • 최진호;김재호;공성호
    • Journal of Korea Soil Environment Society
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    • v.2 no.3
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    • pp.49-57
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    • 1997
  • Naturally-occurring iron minerals, goethite and magnetite, were used to catalyze hydrogen peroxide and initiate Fenton-like oxidation of silica sand contaminated with diesel, kerosene in batch systems. Reaction conditions were investigated by varying H$_2$0$_2$concentration(0%, 1%, 15%), initial contaminant concentration(0.2, 0.5, 1.0g diesel and kerosene/kg soil), and iron minerals(1, 5wt% magnetite or goethite). Contaminant degradations in silica sand-iron mineral-$H_2O$$_2$ systems were identified by determining total petroleum hydrocarbon(TPH) concentration. In case of silica sand contaminated with diesel(1g contaminan/kg soil with 5wt% magnetite) addition of 0%, 1%, 15% of $H_2O$$_2$showed 0%, 25%, and 60% of TPH reduction in 8 days, respectively When the mineral contents were varied from 1 to 5wt%, removal of contaminants increased by 16% for magnetite and 13.1% for goethite. The results from system contaminated by kerosene were similar to those of the diesel. Reaction of magnetite system was more aggressive than that of goethite system due to dissolution of iron and presence of iron(II) and iron(III); however, dissolved iron precipitated on the surface of iron mineral and seemed to cause reducing electron transfer activity on the surface and quenching $H_2$$O_2$. The system used goethite has better treatment efficiency due to less $H_2$$O_2$ consumption. Results of this study showed possible application of catalyzed $H_2$$O_2$ system to petroleum contaminated site without addition of iron source since natural soils generally contain iron minerals such as magnetite and goethite.

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