• Title/Summary/Keyword: Radical removal

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Decomposition of odor using atmospheric-pressure plasma (플라즈마를 이용한 악취물질 분해 특성)

  • Kang, Seok-Won;Lee, Jae-Sik;Lee, Kang-San;Lim, Hee-Ah;Kim, Ji-Seong;Lee, Jeong-Dae;Park, Wol-Su;Park, Young-Koo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.708-718
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    • 2020
  • Offensive odor is recognized as a social environmental problem due to its olfactory effects. Ammonia(NH3), hydrogen sulfide(H2S) and benzene(C6H6) are produced from various petrochemical plants, public sewage treatment plants, public livestock wastes, and food waste disposal facilities in large quantities. Therefore efficient decomposition of offensive odor is needed. In this study, the removal efficiency of atmospheric-pressure plasma operating at an ambient condition was investigated by evaluating the concentrations at upflow and downflow between the plasma reactor. The decomposition of offensive odor using plasma is based on the mechanism of photochemical oxidation of offensive odor using free radical and ozone(O3) generated when discharging plasma, which enables the decomposition of offensive odor at ordinary temperature and has the advantage of no secondary pollutants. As a result, all three odor substances were completely decontaminated within 1 minute as soon as discharging the plasma up to 500 W. This result confirms that high concentration odors or mixed odor materials can be reduced using atmospheric-pressure plasma.

Clinical Studies on Locally Invasive Thyroid Cancer (국소침범한 갑상선암의 임상적 고찰)

  • Kim Young-Min;Lee Chang-Yun;Yang Kyung-Hun;Rho Young-Soo;Park Young-Min;Lim Hyun-Jun
    • Korean Journal of Head & Neck Oncology
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    • v.14 no.2
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    • pp.236-243
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    • 1998
  • Objectives: Local invasion of the thyroid cancer that is invasion of the upper aerodigestive tract, neurovascular structures of the neck and superior mediastinum, is infrequent and comprises of 1-16% of well-differentiated thyroid cancer. However the proximity of the thyroid gland to these structures provides the means for an invasive cancer to gain ready access into theses structures and when invasion occurs, it is the source of significant morbidity and mortality. So locally invasive thyroid cancer should be removed as much as possible, but still much debates have been exist whether the surgical method should be radical or conservative. This study was desinged to evaluate the clinical characteristics and the surgical treatment of the locally invasive thyroid cancer. Material and Methods: At the department of otorhinolaryngology of Hallym university, 10 patients diagnosed as locally invasive thyroid cancer among the 81 patients treated for thyroid cancer between 1991 to 1997 were retrospectively evaluated. Results: Of the 10 patients, 3 patients had histories of previous surgical treatment with or without radiation or radioactive iodine therapy. The site of invasion of thyroid cancer were trachea(7 cases), recurrent laryngeal nerve(5 cases), mediastinal node(5 cases), esophagus(3cases), larynx(3cases), carotid artery(3 cases), pharynx(l case), and other sites(4 cases). The operation techniques included 1 partial laryngectomy and 1 partial cricoid resection, 2 shavings and 3 window resections of the trachea, 1 sleeve resection of the trachea with end-to-end anastomosis and 1 cricotracheoplasty for tracheal invasion, 2 shavings and 1 partial esophagectomies for esophageal invasion, and 1 wall shaving and 2 partial resections with $Gortex^{\circledR}$ tube reconstruction for carotid artery invasion, and so on. Conclusions: These data and review of literature suggest that the surgical method should be perfomed on the basis of individual condition and complete removal of all gross tumor with preservation of vital structures whenever possible will offer a good result.

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