• Title/Summary/Keyword: decontamination methods

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Principles and Applications of Non-Thermal Technologies for Meat Decontamination

  • Yewon Lee;Yohan Yoon
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.19-38
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    • 2024
  • Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

A Study on the Construction of Cutting Scenario for Kori Unit 1 Bio-shield considering ALARA

  • Hak-Yun Lee;Min-Ho Lee;Ki-Tae Yang;Jun-Yeol An;Jong-Soon Song
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4181-4190
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    • 2023
  • Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm2/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

The effects of ozone therapy as an adjunct to the surgical treatment of peri-implantitis

  • Isler, Sila Cagri;Unsal, Berrin;Soysal, Fatma;Ozcan, Gonen;Peker, Elif;Karaca, Inci Rana
    • Journal of Periodontal and Implant Science
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    • v.48 no.3
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    • pp.136-151
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    • 2018
  • Purpose: The decontamination procedure is a challenging aspect of surgical regenerative therapy (SRT) of peri-implantitis that affects its success. The purpose of the present study was to determine the impact of additional topical gaseous ozone therapy on the decontamination of implant surfaces in SRT of peri-implantitis. Methods: A total of 41 patients (22 males, 19 females; mean age, $53.55{\pm}8.98years$) with moderate or advanced peri-implantitis were randomly allocated to the test group (ozone group) with the use of sterile saline with additional ozone therapy or the control group with sterile saline alone for decontamination of the implant surfaces in SRT of peri-implantitis. Clinical and radiographic outcomes were evaluated over a period of 12 months. Results: At the 12-month follow-up, the plaque and gingival index values were significantly better in the ozone group (P<0.05). Probing depth decreased from $6.27{\pm}1.42mm$ and $5.73{\pm}1.11mm$ at baseline to $2.75{\pm}0.7mm$ and $3.34{\pm}0.85mm$ at the end of the 12-month observation period in the ozone and control groups, respectively. Similarly, the clinical attachment level values changed from $6.39{\pm}1.23mm$ and $5.89{\pm}1.23mm$ at baseline to $3.23{\pm}1.24mm$ and $3.91{\pm}1.36mm$ at the 12-month follow-up in the ozone and control groups, respectively. According to the radiographic evidence, the defect fill between baseline and 12 months postoperatively was $2.32{\pm}1.28mm$ in the ozone group and $1.17{\pm}0.77mm$ in the control group, which was a statistically significant between-group difference (P<0.05). Conclusions: Implant surface decontamination with the additional use of ozone therapy in SRT of peri-implantitis showed clinically and radiographically significant. Trial registry at ClinicalTrials.gov, NCT03018795.

The Extraction of Metal Contaminants using Supercritical CO2 (초임계이산화탄소를 이용한 방사성 금속이온 추출)

  • Ju, Minsu;Kim, Jung-Hoon;Kang, Se-Sik
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.660-667
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    • 2016
  • Conventional decontamination methods utilize water-based systems, which generate high amounts of secondary wastes. Herein, we describe an environmentally benign decontamination method using liquid and supercritical $CO_2$. The use of $CO_2$ as a solvent affords effective waste reduction by its ability to be recycled, thereby leaving be hind only the contaminants upon its evaporation. In this study, a $CO_2$ solution process was assessed using t-salen(t-butylsalen), DC18C6 (dicyclohexano-18Crown6), 8-HQN(8-hydroxyquinoline), NEt4PFOSA(perfluoro-1-octanesulfonic acid tetra-ethyl ammonium salt), and NEt4PFOA(pentadecafluorooctanoic acid ammonium salt) to extract spiked radioactive contaminants(Nb,Zr,Co,Sr) from an inert sample matrix, namely filter paper. With the static extraction method, Sr was extracted with a maximum extraction rate of 97%, and Nb was extracted with a maximum extraction rate of 75%. Additionally, we were also able to extract Co and Zr with maximum extract ion ratesof 73% and 64%, respectively.

Regenerative procedure using rotary titanium brush for surface decontamination of peri-implantitis: 3 cases with a 2-year follow-up (회전형 타이타늄 브러쉬를 이용한 임플란트 주위염 재생술식: 2년 추적결과 증례 보고)

  • Baek, Min-Woo;Yu, Jeoung-A;Choi, Seong-Ho;Lee, Dong-Woon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.37 no.4
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    • pp.259-267
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    • 2021
  • Peri-implantitis, in which inflammation caused by plaque and biofilm on the implant surface spreads to the hard tissue, can be treated by decontamination of the implant surface and reconstruction of the lost hard tissue through surgical methods. We have described the management of 3 peri-implantitis cases by decontamination of the implant surface using a round titanium brush and regenerative therapy. All cases showed clinical improvements, and no further radiographic bone loss was observed during a 2-year follow-up. This treatment method can be effective for clinical improvement and bone regeneration. However, a longer follow-up period is necessary to support these outcomes.

Effects of Decontamination Treatments on Chemical Components of Panax Ginseng-Leaf Tea (살균처리가 인삼엽록차의 화학성분에 미치는 영향)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Choi, Kang-Ju;Kwon, Dae-Won;Cho, Han-Ok
    • Korean Journal of Food Science and Technology
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    • v.24 no.1
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    • pp.65-69
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    • 1992
  • The comparative effects of ethylene oxide(EO) fumigation and gamma irradiation (5 kGy) were determined on the chemical components of exportable ginseng-leaf tea which is required for improving the hygienic quality. Saponins and fatty acids detected in the samples were found to be resistant to both treatments at the practical levels. In an experiment on free sugar and amino acids, however, quantitative analysis has shown that glucose, lysine and histidine in the samples are significantly decreased by EO fumigation (p<0.05) and that negligible changes were observed in gamma-irradiated samples.

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A Study on The Assessment of Treatment Technologies for Efficient Remediation of Radioactively-Contaminated Soil (방사성 오염 토양의 효율적 복원을 위한 처리기술 평가 연구)

  • Song, Jong Soon;Shin, Seung Su;Kim, Sun Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.3
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    • pp.245-251
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    • 2016
  • Soil can be contaminated by radioactive materials due to nuclide leakage following unexpected situations during the decommissioning of a nuclear power plant. Soil decontamination is necessary if contaminated land is to be reused for housing or industry. The present study classifies various soil remediation technologies into biological, physics/chemical and thermal treatment and analyzes their principles and treatment materials. Among these methods, this study selects technologies and categorizes the economics, applicability and technical characteristics of each technology into three levels of high, medium and low by weighting the various factors. Based on this analysis, the most applicable soil decontamination technology was identified.

In situ dental implant installation after decontamination in a previously peri-implant diseased site: a pilot study

  • Kim, Young-Taek;Cha, Jae-Kook;Park, Jung-Chul;Jung, Ui-Won;Kim, Chang-Sung;Cho, Kyoo-Sung;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.42 no.1
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    • pp.13-19
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    • 2012
  • Purpose: The aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases. Methods: A peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with $H_2O_2$. Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically. Results: The untreated implants and $H_2O_2$-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site. Conclusions: It can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.

Diagnosis and treatment of Peri-implantitis (Peri-implantitis의 진단 및 치료)

  • Koo, Ki-Tae
    • The Journal of the Korean dental association
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    • v.54 no.4
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    • pp.252-257
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    • 2016
  • This manuscript aims at discussing the technical and biological aspects of peri-implant disease. The following contents will be discussed. -The difference between peri-implantitis and peri-implant mucositis. -Prevalence of peri-implant disease. -Risk factors for peri-implantitis. -Indications and boundaries of non-surgical and surgical treatment -Treatment flow-chart by Schwarz -Limitations of non-surgical treatment -Methods to decontaminate diseased surfaces -Importance of defect configuration in surgical treatment -Biomechanical factors that influence the progression and decontamination related to peri-implantitis -Maintenance of implants.

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Evaluating Commercial Spray Applications of Lactic Acid, Hot Water, and Acidified Sodium Chlorite for the Reduction of Escherichia coli on Beef Carcasses

  • Kang, Dong-Hyun;Lee, Sun-Young
    • Food Quality and Culture
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    • v.2 no.1
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    • pp.55-60
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    • 2008
  • This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water ($89{\pm}1^{\circ}C$), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.

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