• Title/Summary/Keyword: Radical removal

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Preparation of Fe-ACF/TiO2 Composites and their Photocatalytic Degradation of Waste Water

  • Oh, Won-Chun;Bae, Jang-Soon
    • Journal of the Korean Ceramic Society
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    • v.45 no.11
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    • pp.667-674
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    • 2008
  • In this study, we prepared Fe-activated carbon fiber(ACF)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/$TiO_2$ composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/$TiO_2$ composites. The chemical composition of the Fe-ACF/$TiO_2$ composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/$TiO_2$ composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported $TiO_2$, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF.

Measurements of Internal Auditory Meatus on Skull of Korean (한국인 두개골에 대한 내이도 계측)

  • 김진영;김희남;김영명;김기령;홍성우
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1972.03a
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    • pp.1.3-1
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    • 1972
  • The are early diagnosis of acoustic neuroma is important for radical removal of it and for early radiologic diagnosis which was considered to be the most reliable method it is required to know the normal dimension of the internal auditory meatus. There are two methods for internal auditory meatal measurement; one is indirect, such as the conventional roentogenography, laminoraphy and cisternography and the other is direct using rubber cast method of Amjad, A.H. et. al. Authors measured the anatomical dimensions of Korean adult internal auditory meatus with regular rubberbase impression material.

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Numerical Study of the Effects of Hydrocarbon Addition and Corresponding Chemical Kinetics on the Promotion of NO Oxidation in Nonthermal Plasma DeNOx Treatment (비열 플라즈마에 의한 NO의 산화에서의 탄화수소 첨가 효과와 그 반응역학에 대한 수치적 연구)

  • Shin, Hyun-Ho;Yoon, Woong-Sup
    • Journal of the Korean Society of Combustion
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    • v.5 no.2
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    • pp.37-50
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    • 2000
  • In the present study, a systematic chemical kinetic calculations were made to investigate the augmentation of $NO-NO_2$ conversion due to the addition of various hydrocarbons (methane, ethylene, ethane, propylene, propane) in the nonthermal plasma treatment. It is included in the present conclusion that the reaction between hydrocarbon and oxygen radicals induced by electron collision, is believed to be a primarily process for triggering the overall NO oxidation and the eventual NOx reduction. Upon the completion of the initiating step, various radicals (OH, $HO_2$ etc.) successively are produced by hydrocarbon decomposition form the primary path of $NO-NO_2$ conversion. When the initiating step is not activated, hydrocarbon consumption rate appeared to be very low, thereby the targeted level of NO conversion can only be achieved by the addition of more input energy. Present study showed ethylene and propylene to have higher affinity with O radical under all conditions, thereby both of these hydrocarbons show very fast and efficient $NO-NO_2$ oxidation. It was also shown that propylene is superior to ethylene in the aspect of NOx removal.

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A DIAGNOSIS OF SUBMANDIBULAR SIALOLITHIASIS WITH COMPUTED TOMOGRAPHY (전산화 단층촬영술을 이용한 악하선 타석증의 진단)

  • Koo, Chi-Kyun;Choi, Hyung-Jun;Lee, Jong-Gap;Lee, Jae-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.25 no.3
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    • pp.545-548
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    • 1998
  • Sialolithiasis is the formation of calcareous concretions within ductal system of a major or minor salivary gland. They are formed by deposition of calcium salts around a central nidus which may consist of desquamated epithelial cells, bacteria, foreign bodies, or products of bacterial decomposition. An 11-year-old boy complained of pain during meals and intermittent mild swelling in the right submandibular region. Although it was not detected in true occlusal radiograph, panoramic radiograph showed a round radiopaque mass 3mm in diameter. Computed tomography(CT) was taken for locating the stone and 3-dimensional reconstruction was performed. Under general anesthesia, sialoadenectomy was done through extraoral approach. Diagnosis of submandibular sialolithiasis using high-resolution CT with reconstructions was helpful for surgical decisions, namely radical removal of the submandibular gland and its duct.

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A CLINICAL STUDY ON THE APPLICATION OF LABIO-MANDIBULOTOMY APPROACH FOR ORAL AND OROPHARYNGEAL TUMORS (구강 및 구인두종양수술시 구순-하악골이단 접근법의 이용에 관한 임상적 연구)

  • Pyo, Sung-woon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.21 no.2
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    • pp.225-230
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    • 1999
  • The labiomandibulotomy approch to the oral cavity and oropharygeal region was first described by Roux in 1836 and become popular for oral and oropharyngeal tumors in cases where there are no clinical and radiological signs of mandible invasion. Anterior labiomandibulotomy and swing procedure provides excellent access and facilitate a mandibular resection and subsequent repair. In last two years, 8 cases of oral and oropharyngeal tumors were treated by this approach at the Dept. of Oral & Maxillofacial Surgery, Holy Family Hospital, Catholic University of Korea. And we analyzed postoperative complications as well as functional evaluations, and the results were as follows; In 4 cases, marginal mandibulectomy were combined with labiomandibulotomy and in case of malignancies, neck dissection was performed simultaneously. In almost case, plate and miniscrew fixation was used for osteotomy sites. Histologic evaluation of the resection margins of the specimens revealed tumor free in all cases. The postoperative complications were occured in 3 cases, one case of nonunion, one case of orocutaneous fistula, and one case of wound dehisence. Occlusal stability, jaw movement and swallowing function were acceptable postoperatively in 3 months. From above results, we concluded that, this approach not only provides wide exposure, permitting radical removal of benign and malignant lesions but also preserves function with minimal complications.

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Maltol, an Antioxidant Component of Korean Red Ginseng, Shows Little Prooxidant Activity

  • Suh, Dae-Yeon;Han, Yong-Nam;Han, Byung-Hoon
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.112-115
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    • 1996
  • Some antioxidant phenolic compounds exhibit prooxidant activity mainly due to their abilities to reduce $Fe^{3+}\; to\; Fe^{2+}.$ Reducing ability and prooxidant activity of maltol, an antioxidant component of Korean red ginseng, were compared with those of pyrogallol. Maltol at 2 mM did not appreciably reduce$ Fe^{3+}\; to\; Fe^{2+}$ and also failed to reduce nitroblue tetrazolium. Stimulation of hydroxyl radical mediated-deoxyribose degradation by pyrogallol was maximal at 60 .mu.M. Maltol stimulated the deoxyribose degradation to a much less extent, and a similar stimulatory effect was observed at a concentration of more than 100-fold higher than that of pyrogallol. The stimulatory effect of maltol reached a plateau over 1 mM, suggesting the removal of hydroxyl radicals by excess maltol. In bleomycin-$Fe^{3+}$-DNA assay, maltol at 2 mM produced a 2.5-fold increase of the iron-bleomycin-dependent DNA degradation over the basal value, whereas pyrogallol at 10 .mu.M accelerated DNA degradation by ca. 10-fold. Furthermore, maltol inhibited $Fe^{2+}$-stimulated DNA degradation by bleomycin. These results strongly suggested that maltol is an antioxidant with little prooxidant activity.

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Removal of Phenanthrene by Electrokinetic-Fenton Process in a 2-dimensional Soil System (동전기-펜턴 공정을 이용한 2차원 토양 정화장치에서의 phenanthrene 제거)

  • Park Ji-Yeon;Kim Sang-Joon;Lee You-Jin;Yang Ji-Won
    • Journal of Soil and Groundwater Environment
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    • v.10 no.5
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    • pp.11-17
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    • 2005
  • Characteristics of phenanthrene removal in the Electrokinetic (EK)-Fenton process were investigated in a 2-dimensional test cell in a viewpoint of the effect of gravity and electrosmotic flow (EOF). When the constant voltage of 100 V was applied to this system, the current decreased from 1,000 to 290 mA after 28 days, because soil resistance increased due to the exhaustion of ions in soil by electroosmosis and electromigration. Accumulated EOF in two cathode reservoirs was 10.3 L and the EOF rate was kept constant for 28 days. At the end of operation, the concentration of phenanthrene was observed to be very low near the anode and increased in the cathode region because hydrogen peroxide was supplied from anode to cathode region following the direction of EOP. Additionally, the concentration of phenanthrene decreased at the bottom of the test cell because the electrolyte solution containing hydrogen peroxide was largely transported toward the bottom due to a low capillary action in the soil with high porosity. Average removal efficiency of phenanthrene by EK-Fenton process was 81.4% for 28 days. In-situ EK-Fenton process would overcome the limitations of conventional remediation technologies and effectively remediate the contaminated sites.

Combined Modality Therapy with Selective Bladder Preservation for Muscle Invading Bladder Cancer (침윤성 방광암 환자에서 방광 보존 치료)

  • Youn Seon Min;Yang Kwang Mo;Lee Hyung Sik;Hur Won Joo;Oh Sin Geun;Lee Jong Cheol;Yoon Jin Han;Kwon Heon Young;Jung Kyung Woo;Jung Se Il
    • Radiation Oncology Journal
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    • v.19 no.3
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    • pp.237-244
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    • 2001
  • Purpose : To assess the tolerance, complete response rate, bladder preservation rate and survival rate in patients with muscle-invading bladder cancer treated with selective bladder preservation protocol. Method and Materials : From October 1990 to June 1998, twenty six patients with muscle-invading bladder cancer (clinical stage T2-4, N0-3, M0) were enrolled for the treatment protocol of bladder preservation. They were treated with maximal TURBT (transurethral resection of bladder tumor) and 2 cycles of MCV chemotherapy (methotrexate, crisplatin, and vinblastine) followed by $39.6\~45\;Gy$ pelvic irradiation with concomitant cisplatin. After complete urologic evaluation (biopsy or cytology), the patients who achieved complete response were planed for bladder preservation treatment and treated with consolidation cisplatin and radiotherapy (19.8 Gy). The patients who had incomplete response were planed to immediate radical cystectomy. If they refused radical cystectomy, they were treated either with TURBT followed by MCV or cisplatin chemotherapy and radiotherapy. The median follow-up duration is 49.5 months. Results : The Patients with stage T2-3a and T3b-4a underwent complete removal of tumor or gross tumor removal by TURBT, respectively. Twenty one out of 26 patients $(81\%)$ successfully completed the protocol of the planned chemo-radiotherapy. Seven patients had documented complete response. Six of them were treated with additional consolidation cisplatin and radiotherapy. One patient was treated with 2 cycles of MCV chemotherapy due to refusal of chemo-radiotherapy. Five of 7 complete responders had functioning tumor-free bladder. Fourteen patients of incomplete responders were further treated with one of the followings : radical cystectomy (1 patient), or TURBT and 2 cycles of MCV chemotherapy (3 patients), or cisplatin and radiotherapy (10 patients). Thirteen patients of them were not treated with planned radical cystectomy due to patients' refusal (9 patients) or underlying medical problems (4 patients). Among twenty one patients, 12 patients $(58\%)$ were alive with their preserved bladder, 8 patients died with the disease, 1 patient died of intercurrent disease. The 5 years actuarial survival rates according to CR and PR after MCV chemotherapy and cisplatin chemoradiotherapy were $80\%\;and\;14\%$, respectively (u=0.001). Conclusion : In selected patients with muscle-invading bladder cancer, the bladder preservation could be achieved by MCV chemotherapy and cisplatin chemo-radiotherapy. All patients tolerated well this bladder preservation protoco. The availability of complete TURBT and the responsibility of neoadjuvant chemotherapy and chemoradiotherapy were important predictors for bladder preservation and survival. The patients who had not achieved complete response after neoadjuvant chemotherapy and chemoradiotherapy should be immediate radical cystectomy. A randomized prospective trial might be essential to determine more accurate indications between cystectomy or bladder preservation.

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Components and Biological Activity of Aqueous Extract Isolated from Winged Stem of Euonymus alatus (화살나무 물 추출물의 구성성분과 생리활성)

  • Oh, Bong-Yun;Hwang, Soo-Kyung;Cheong, Mi-Young;Sin, Hong-Sig;Park, Bock-Hee;Lee, Jeong-Ho;Kim, Soo-Hyun
    • Korean Journal of Food Science and Technology
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    • v.37 no.6
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    • pp.898-904
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    • 2005
  • Although Euonymus alatus (EA) has been used as traditional medicine for cancer treatment, exact substances involved in curing of the disease are not yet known. Free radical scavenging and reactive oxygen species (ROS) removal activities of aqueous extract components isolated from winged stem of EA in animal cell line were investigated. Aqueous extract of EA (AEEA) was fractionated by ultrafiltration. All fractions mainly consisted of polysaccharide (44.8%), protein (2.1%), small amounts of phenol compounds and organic acids. Antioxidant activity of AEEA increased depending on concentration fractions, as determined by 1,1-diphenyl-2-picrylhydrazyl method. ROS removal activity was visualized in Chinese hamster ovary cell line using laser scanning confocal microscope, and AEEA activity increased in order of F IV>F III>F I>F II. These results suggest AETA has bioactive carbohydrates with potentials as functional foods and antioxidants.

Oxidation of Geosmin and 2-MIB in Water Using $O_3/H_2O_2$: Kinetic Evaluation (오존과 과산화수소를 이용한 Geosmin과 2-MIB 산화: 동력학적 평가)

  • Lee, Hwa-Ja;Son, Hee-Jong;Roh, Jae-Soon;Lee, Sang-Won;Ji, Ki-Won;Yoo, Pyung-Jong;Kang, Lim-Seok
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.7
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    • pp.826-832
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    • 2007
  • Unpleasant tastes and odors in drinking water cause same problems for water utilities across Korea. Even though tastes and odors do not create health problems, they are main concerns for consumers who determine the safety of their drinking water. In this study, two different odor producing compounds(geosmin 2-MIB) in the Nakdong river water and rapid sand filtered rater were treated by advanced oxidation of $O_3/H_2O_2$ process. The experimental results showed that the removal efficiency of geosmin with the use of 5 mg/L of $O_3$ and $H_2O_2$ was higher than efficiency with the use of $O_3$ alone for both the raw water and the sand filtered water. And in general, the removal efficiency of geosmin was higher than 2-MIB in the sand filtered water. Under the range of $O_3$ concentration $0.5\sim2.0$ mg/L, the removal rate constants(k) of geosmin for the raw and sand filtered waters, and the one of 2-MIB in the sand filtered water were increased rapidly as doses of $O_3$, and $H_2O_2$, increased. The removal rate constants(k) do not increase any more when $H_2O_2/O_3$ ratio increases above the optimum ratio. The optimum ratio of $H_2O_2/O_3$, dose was $1.0\sim2.0$ for both geosmin and 2-MIB. The removal rate constant(k) becomes lower when OH radical consuming materials are present in raw water. The half-life of geosmin decreased rapidly as the $O_3$ and $H_2O_2$ doses increase in the sand filtered water. The half life decreased about 8.5 times with the use of 2 mg/L of $O_3$ and 10 mg/L of $H_2O_2$ than with the use of 2 mg/L of $O_3$ alone for the sand filtered water.