• 제목/요약/키워드: $NO_x$ removal

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Low Temperature Selective Catalytic Reduction of NO with $NH_3$ over Mn/$CeO_2$ and Mn/$ZrO_2$ (Mn/$CeO_2$와 Mn/$ZrO_2$ 촉매 상에서 $NH_3$를 사용한 NO의 선택적 촉매 산화 반응)

  • Ko, Jeong Huy;Park, Sung Hoon;Jeon, Jong-Ki;Sohn, Jung Min;Lee, See-Hoon;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.23 no.1
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    • pp.105-111
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    • 2012
  • Manganese (Mn) catalysts were generated using $CeO_2$ and $ZrO_2$supports synthesized by the supercritical hydrothermal method and two different Mn precursors, aimed at an application for a low-temperature selective catalytic reduction process. Manganese acetate (MA) and manganese nitrate (MA) were used as Mn precursors. Effects of the kind and the concentration of the Mn precursor used for catalyst generation on the NOx removal efficiency were investigated. The characteristics of the generated catalysts were analyzed using $N_2$ adsorption-desorption, thermo-gravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. De-NOx experiments were carried out to measure NOx removal efficiencies of the catalysts. NOx removal efficiencies of the catalysts generated using MA were superior to those of the catalysts generated using MN at every temperature tested. Analyses of the catalyst characteristics indicated that the higher NOx removal efficiencies of the MA-derived catalysts stemmed from the higher oxygen mobility and the stronger interaction with support material of $Mn_2O_3$ produced from MA than those of $MnO_2$ produced from MN.

CASE REPORTS ON THE REMOVABLE PARTIAL DENTURES WITH DONUS TELESCOPE (Konus telescope에 의한 유리단 결손 수복에 관한 임상적 연구(I))

  • Vang, Mong-Sook
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.1
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    • pp.67-77
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    • 1997
  • The purpose of this study was to evaluate a cases which was treated with konus telescope on the patients in bilaterally edentulous mandible. Author made konus telescope for two patients and then X-ray and clinical examination were used for evaluation of the function and change in supporting structure of the abutment teeth during the 60months. Patient complained of difficulties in removal of denture at the beginning but they got used to it soon. X-ray showed that there were no changes in supporting structure of the abutment teeth after 60 months. It was effective in promotion of ridge soreness and also reducing the need of relining. This study suggest that konus telescope was effective for the treatment of bilaterally edentulous situations.

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Development of a Commercial-scale RDF Boiler with Chain type Stoker (실증규모 체인스토커식 RDF전용보일러 개발)

  • Choi, Yeon-Seok;Kim, Byung-Gil;Roh, Nam-Sun
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.813-816
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    • 2009
  • A commercial-scale RDF boiler that its burning capacity is 400 kg-RDF/hr and steam production capacity is 2 ton/hr. It has a chain type stoker and waste heat recovery system. Heat exchanger is vertical water-pipe so that soot blowing and removal is convenient during operation. Dry scrubber, bag filter and activated carbon tower have been installed for the reduction of air pollutant gases and dust. Analysing data of pollutants from stack such as $SO_x$. $NO_x$ and dioxin shows so good results that the boiler system could comply the regulated emission limits.

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Mediastinal lipoma and liposarcoma (종격동 지방종 및 지방육종: 3례 보고)

  • Kim, Won-Gon;Kim, Ju-Hyeon
    • Journal of Chest Surgery
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    • v.16 no.3
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    • pp.375-380
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    • 1983
  • The lipomatous of the mediastinum are fairly uncommon tumors. Since 1971, two patients with proven mediastinal lipoma and one primary liposarcoma of the mediastinum have been treated at the Seoul National University Hospital. This report reviews our experience with the review of literature. Case 1.: A 3 year old body revealed a huge round homogenous mass density in the posterior mediastinum in routine chest X-ray. The tumor mass, lipoma, was successfully removed and postoperative course was uneventful. Cases 2.: An asymptomatic 24 year old male was operated on with the preoperative diagnosis of mediastinal lipoma. His preoperative chest X-ray and CT films showed a huge anterior to middle mediastinal tumor, right, with fat density. There is no postoperative problem after successful removal of the tumor mass. Case 3. : A 24 year old female was hospitalized with the complaints of cough and chest pain. A mediastinal mass was removed, which proved to be a liposarcoma on pathologic examination. About one year later, she was found to have recurrent liposarcoma in the right chest area at the OPD follow-up. She was lost to follow-up since then.

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"DUMBBELL" Neurilemmoma -1 case Report- (DUMBBELL 신경종양 -1례 보고-)

  • 박영환
    • Journal of Chest Surgery
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    • v.23 no.3
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    • pp.556-560
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    • 1990
  • A 22 year old soldier was discovered on routine study for discharge to have a mass in the posterior mediastinum He was admitted due to high fever and improved by antibiotic treatment for 2 weeks. Chest PA, apicogram, myelogram and CT scan demonstrated enlargement of the neural foramen at the T1 level with erosion of the posterior aspect of the vertebral body and the pedicle contiguous with the intrathoracic mass, A myelogram showed a large extradural defect at the T1 level on the left. There were no clinical signs of cord compression. A standard posterolateral thoracotomy incision was made with extension to high thoracic vertebra. The 3rd rib was resected and the angles of the posterior portion of 1st and 2nd ribs were cut and rib heads were removed. Extrapleural neurilemmoma 6x6 cm was resected intrathoracically. And after removal of the pedicle and the lamina, intraspinal extradural mass 3 X 2 cm was resected carefully with trivial tearing of the dura which was sealed with gel-foam and pleura. There was ma postoperative neurological complication.

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The Effectiveness of Bladder Training on Self Voiding after Removal of Catheter in Female Patients with Craniotomy (개두술 여성환자에게 시행한 방광훈련이 유치도뇨관제거후 자가배뇨에 미치는 효과)

  • Lee, Jung-Lim;Kim, Keum-Soon
    • The Korean Journal of Rehabilitation Nursing
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    • v.2 no.1
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    • pp.72-84
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    • 1999
  • The purpose of this study was to identify the effectiveness of bladder training on self voiding after removal of catheter in female patients with craniotomy, finally to develop a bladder rehabilitation program for cognitive impaired patients. Nonequivalent control group posttest design was used. The population of this study consisted of 34 hospitalized neurosurgical patients, all patients have been received craniotomy. 17 patients were assigned to the experimental group and another 17 patients to the control group. The homogeneity of general characteristics of the subjects was no significant difference. Bladder training program consisted of pre-training education, the bladder training, positive verbal reinforcement. The experimental group has been received bladder training and the control group has been received gravity drainage. The dependent variable, the frequency of voiding trial untill self voiding achieves, the frequency of urinary retention, the amount of residual urine, the occurrence, of urinary incontinence, were measured during 3 days after catheter removed. The data analyzed with SPSSWIN ; frequency, percentage, t-test and $X^2$-test were used to analyze homogeneity of general characteristics of subjects between the experimental and the control group. T-test, Mann-Whitney U test, and $X^2$-test were used to determine the effect of bladder training. The result of the study were as follows : There was significant difference in the frequency of voiding trial untill self voiding achieves between the experimental group and the control group. There was no significant difference in the frequency of urinary retention between the experimental group and the control group. There was no significant difference in the amount of residual urine between the experimental group and the control group. However, there was significant difference in the amount of residual urine in urinary retention patients. There was significant difference in the occurrence of urinary incontinence between the experimental group and the control group. In conclusion, bladder training program as a nursing intervention was effective in conclusion, bladder self voiding ability after removal of catheter for craniotomy patients. Therefore, it is recommended to use the bladder training program clinically for the bladder management of cognitive impaired patients.

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Modeling Study on Dispersion and Scavenging of Traffic Pollutants at the Location Near a Busy Road

  • Ma, Chang-Jin
    • Asian Journal of Atmospheric Environment
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    • v.9 no.4
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    • pp.272-279
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    • 2015
  • The information about the dispersion and scavenging of traffic-related pollutants at the locations near busy expressways is very helpful to highway planners for developing better plans to reduce exposures to air pollution for people living as well as children attending schools and child care centers near roadways. The objective of the current study was to give information in the dispersion and scavenging of vehicle-derived pollutants at the region near a busy urban expressway by a combination of two different model calculations. The modified Gaussian dispersion model and the Lagrange type below-cloud scavenging model were applied to evaluate $NO_x$ dispersion and DEP (Diesel exhaust particles) wet removal, respectively. The highest $NO_x$ was marked 53.17 ppb within 20-30 meters from the target urban expressway during the heaviest traffic hours (08:00AM-09:00AM) and it was 2.8 times higher than that of really measured at a nearby ambient measuring station. The calculated DEP concentration in size-resolved raindrops showed a continuous decreasing with increasing raindrop size. Especially, a noticeable decrease was found between 0.2 mm and 1.0 mm raindrop diameter.

Microalgal Removal of $CO_2$from Flue Gases: Changes in Medium pH and Flue Gas Composition Do Not Appear to Affect the Photochemical Yield of Microalgal Cultures

  • Olaizola, Miguel
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.6
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    • pp.360-367
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    • 2003
  • Our research objectives are to determine under what conditions microalgal-based $CO_2$capture from flue gases is economically attractive. Specifically, our objective here was to select microalgae that are temperature, pH and flue gas tolerant. Microalgae were grown under five different temperatures, three different pH and five different flue gas mixtures besides 100% $CO_2$(gas concentrations that the cells were exposed to ranged 5.7-100% $CO_2$, 0-3504ppm SO$_2$, 0-328ppm NO, and 0-126ppm NO$_2$). Our results indicate that the microalgal strains tested exhibit a substantial ability to withstand a wide range of temperature (54 strains tested), pH (20 strains tested) and flue gas composition (24 strains tested) likely to be encountered in cultures used for carbon sequestration from smoke stack gases. Our results indicate that microalgal photosynthesis is a limited but viable strategy for $CO_2$capture from flue gases produced by stationary combustion sources.

Mitral Valve Replacement: A Case Report (승모판막 이식수술 1례 보고)

  • 양기민
    • Journal of Chest Surgery
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    • v.4 no.1
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    • pp.51-54
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    • 1971
  • 37 years old female was admitted with chief complaints of dyspnea on exertion and hemoptysis. Past history and family history were non-contributory. Physical examination showed Grade III systolic murmur at the apex, which transmitted to the back. E. K. G. and X-ray findings were compatible with the mitral insufficiency. With small size of Beall mitral valve, mitral valve replacement was done under the cardia-pulmonary bypass using hemodilution technic. Patient was tracheotomized after operation and assisted respiration was done for four weeks. Postoperatively, all signs were fine and patient walked around the ward without any difficulty, but she was in psychotic state. On postoperative 60th day, she complained of sudden dyspnea and on chest film, tracheal stenosis was found and recannulation of the tracheal tube was made. Thereafter, she was quite fine until postoperative 110th day when she, by berself, removed the tracheal cannula and died of asphyxia. Autopsy findings of the valve showed no thrombosis, no variance of the valve, and good endothelization of the valve cuffs. Asphyxia, due to removal of the tracheal connula by herself under psychotic state, was considered to be the cause of death in this patient who had tracheal stenosis after tracheostomy.

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"DUMBBELL" Neurilemmoma -A Case Report- ("DUMBBELL" 신경종양 -1례 보고-)

  • Park, Jin-Seok;Im, Seung-Pyeong;Kim, Gwan-Tae
    • Journal of Chest Surgery
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    • v.27 no.6
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    • pp.502-505
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    • 1994
  • Neurogenic tumors of the mediastinum may have an intraspinal component connected by a narrowed segment of tumor in the intervertebral foramen,hence the descriptive term dumbbell.Recently we had an occasion to remove a dumbbell neurilemmoma in a 62 years old woman using an approach designed to allow wide posterolateral thoracotomy and concomitant laminectomy for a single stage removal of the entire tumor. The mass in the posterior mediastinum was discovered on routine chest roentgenography. CT scan demonstrated a dumbbell shaped soft tissue mass density compressing spinal canal but preserving spinal cord. There were no neurologic signs. A standard posterolateral thoracotomy incision was made to remove tumor mass and then T5 unilateral laminectomy has done by Neurosurgeon. 7 x 7 cm sized extrapleural neurilemmoma was round, cystic, soft mass which covered parietal pleural with invaded regional vertebrae. There was no postoperative neurological complication.

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