• Title/Summary/Keyword: Spontaneous removal

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Kinetic and Thermodynamic Studies of Brilliant Green Adsorption onto Carbon/Iron Oxide Nanocomposite (탄소/산화철 나노복합재료의 Brilliant Green 흡착에 대한 반응속도론적, 열역학적 연구)

  • Ahmad, Rais;Kumar, Rajeev
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.125-130
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    • 2010
  • In the present work, we have investigated the adsorption efficiency of carbon/iron oxide nanocomposite towards removal of hazardous brilliant green (BG) from aqueous solutions. Carbon/iron oxide nanocomposite was prepared by chemical precipitation and thermal treatment of carbon with ferric nitrate at $750^{\circ}C$. The resulting material was thoroughly characterized by TEM, XRD and TGA. The adsorption studies of BG onto nanocomposite were performed using kinetic and thermodynamic parameters. The adsorption kinetics shows that pseudo-second-order rate equation was fitted better than pseudo-first-order rate equation. The experimental data were analyzed by the Langmuir and Freundlich adsorption isotherms. Equilibrium data was fitted well to the Langmuir model with maximum monolayer adsorption capacity of 64.1 mg/g. The thermodynamic parameters were also deduced for the adsorption of BG onto nanocomposite and the adsorption was found to be spontaneous and endothermic.

A Comparative Study on Adsorption Characteristics of PCBs in Transformer Oil Using Various Adsorbents (여러 흡착제를 이용한 변압기 오일 중의 PCBs 흡착특성에 관한 비교연구)

  • Ryoo, Keon Sang;Hong, Yong Pyo;Ahn, Chun Ju
    • Journal of the Korean Chemical Society
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    • v.56 no.6
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    • pp.692-699
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    • 2012
  • The aim of the present study is to explore the possibility of utilizing loess and fly ash as well as activated carbon for the adsorptive removal of PCBs in transformer oil. Here, we investigated the effect of various factors such as temperature (5, 25, 55), contact time (30 min-3 day) and adsorbent does (1, 2.5, 5, 10 g) in detail. It was found that PCBs adsorption rate from transformer oil by activated carbon is more favored than loess at the equilibrium time of 60 minutes. The equilibrium data for both activated carbon and loess is fitted well to the Freundlich isotherm model. The rate constant and activation energy of PCBs adsorption in transformer oil on each adsorbent was analyzed by fitting a kinetic model at 5, 25 and $55^{\circ}C$. From the thermodynamic parameters, the PCBs adsorption process for transformer oil/activated carbon and loess system is spontaneous and endothermic in nature.

Adsorption Characteristics of Sr Ions by Coal Fly Ash-Based-Zeolite X using Response Surface Modeling Approach (반응표면분석법을 이용한 석탄회로 합성한 제올라이트 X에서의 Sr 이온 제거특성)

  • Lee, Chang-Han;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.26 no.6
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    • pp.719-728
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    • 2017
  • In order to investigate the adsorption characteristics for Sr ion using the Na-X zeolite synthesized from coal fly ash, batch tests and response surface analyses were carried out. The adsorption kinetic data for Sr ions, using Na-X zeolite, fitted well with the pseudo-second-order model. The uptake of Sr ions followed the Langmuir isotherm model, with a maximum adsorption capacity of 196.46 mg/g. Thermodynamic studies were conducted at different reaction temperatures, with the results indicating that Sr ion adsorption by Na-X zeolite was an endothermic (${\Delta}H^o$>0) and spontaneous (${\Delta}G^o$<0) process. Using the response surface methodology of the Box-Behnken method, initial Sr ion concentration ($X_1$), initial temperature ($X_2$), and initial pH ($X_3$) were selected as the independent variables, while the adsorption of Sr ions by Na-X zeolite was selected as the dependent variable. The experimental data fitted well with a second-order polynomial equation by multiple regression analysis. The value of the determination coefficient ($R^2=0.9937$) and the adjusted determination coefficient (adjusted $R^2=0.9823$) was close to 1, indicating high significance of the model. Statistical results showed the order of Sr removal based on experimental factors to be initial pH > initial concentration > temperature.

Major Hemothorax Induced Hypovolemic Shock Fallowing Administration of Intrapleural Urokinase (늑막강내 Urokinase 주입후 발생된 Major Hemothorax에 기인된 Hypovolemic shock)

  • Kim, Jung Kyu;Jung, In Beom;Son, Ji Woong;Choi, Eugene;Na, Moon Jun;Lee, Won Young;Cho, Young Jun
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.5
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    • pp.465-469
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    • 2004
  • Exudative pleural effusion can arise from pneumonia, tuberculosis, cancer, etc. Early drainage is needed for prevention of complications such as pleural fibrosis, thickening, bronchopleural fistulae and decline of lung function. Intrapleural Instillation of fibrinolytic enzymes has been used for 50years as an adjunct in the removal of fibrous material, hematoma and pus from the thoracic cavity. By the local fibrinolytic effect on fibrinous exudates within the pleural space, fibrinolytic agent has improved results of chest tube or pig tail drainage. But there were no controlled randomized studies, so significant controversy exists concerning the efficacy of this therpy, especially tuberculous pleurisy. Furthermore about complication, severe spontaneous bleeding has not been reported with intrapleural urokinase. Intrapleural fibrinolytic enzymes has shows no systemic complication. When it is administrated intravenously, not into intrpleural space, major bleeding is reported about 1-3% of patient, especially they had systemic disease, such as coagulation abnormalities. This case report presents a patient who suffered major hemothorax induced hypovolemic shock following the administration of 100,000 units of urokinase intrapleurally. He was 25-year old male with tuberculosis pleurisy without systemic illness demonstraion.

Inferior Vena Cava Thrombectomy in a Patient with Antiphospholipid Syndrome - A case report - (하대정맥의 혈전증을 동반한 인지질항체 증후군의 수술적 치료 - 1예 보고 -)

  • Jang, Jae-Seok;Kwon, Oh-Choon;Lee, Sub;Kim, Seok
    • Journal of Chest Surgery
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    • v.42 no.3
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    • pp.371-374
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    • 2009
  • A 36-year-old woman with a history of spontaneous abortion and photosensitivity was admitted to our hospital with periumbilical pain and lower extremity edema. The preoperative CT scan revealed massive inferior vena cava thrombus, which extended from the suprarenal portion of the vena cava to the hepatic vein. The laboratory data showed an elevated level of anticardiolipin antibody, which suggested the diagnosis of antiphospholipid syndrome. After medical management, she underwent an operation for removal of an vena cava thrombus by performing cavectomy and thrombectomy. After the operation, she has been taking oral anticoagulation and she is doing quite well at 9 months after her operation.

Bilateral Intralobar Pulmonary Sequestration with Horseshoe Lung A near suggestion about the treatment of pulmonary sequestration (마제상폐를 보이는 양측성 엽내형 폐격리증의 외과적 치료 -폐격리증치료에 대한 새로운 제안-)

  • 박종빈;김용희
    • Journal of Chest Surgery
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    • v.30 no.2
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    • pp.226-230
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    • 1997
  • This is a case report of surgical management of a bilateral intralobar pulmonary sequestration with horseshoe lung presenting with frequent U I with productive sputum. Simple chest X-ray showed pneumonic consolidation and infiltration on both lower lobes, and chest CT revealed multiple cystic lesions compatible with pulmonary sequestration. The aortography demonstrated two anomalous systemic arteries arising from the thoracic aorta just above the diaphragm to both sequestrums. Left lower lobectomy was performed through the left thoracotomy with ligations and divisions of the both systemic feeding arteries to the left and right sequestrum, and division of the isthmic portion of horseshoe lung without removal of right sequestrum. The patient was discharged on the postoperative loth day and followed-up till now without any sequelae and symptoms of residual right sequestration. The recent follow-up chest CT 5 months after the operation revealed spontaneous regression of the residual right sequestrum. Authors would suggested that only division of aberrant artery to sequestrum without lobectomy may be applied in uncomplicated ca e of intrapulmonary seqilestration.

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Plastic bronchitis in children: 2 cases (소아 증식성 기관지염 2례)

  • Kim, Yeo Hyang;Choi, Hee Jung;Kim, Jung Ok;Hyun, Myung Chul
    • Clinical and Experimental Pediatrics
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    • v.52 no.7
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    • pp.832-836
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    • 2009
  • Plastic bronchitis is a rare disorder characterized by the formation of extensive, obstructing endobronchial casts. It is associated with asthma and complex cardiac defects such as those requiring the Fontan procedure. The treatment of plastic bronchitis comprises conventional therapy involving spontaneous expectoration and bronchoscopic removal and specific therapy with several new drugs. Herein, we describe the cases of 2 patients diagnosed with plastic bronchitis accompanied with a different underlying disease, which were treated with inhaled corticosteroid and low-dose oral clarithromycin.

Pregnancy and fertilization potential of immature oocytes retrieved in intracytoplasmic sperm injection cycles

  • Ko, Duck Sung;Lee, Sun-Hee;Park, Dong-Wook;Yang, Kwang Moon;Lim, Chun Kyu
    • Clinical and Experimental Reproductive Medicine
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    • v.42 no.3
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    • pp.118-125
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    • 2015
  • Objective: The goal of this study was to evaluate the pregnancy potential of immature (metaphase I or germinal vesicle stage) oocytes retrieved in intracytoplasmic sperm injection (ICSI) cycles. Methods: A total of 1,871 couples with infertility underwent 2,984 ICSI cycles. Cycles in which three or fewer oocytes were retrieved were included in this study in order to evaluate the pregnancy potential of immature oocytes. Cycles were divided into five groups (group I-V), according to the maturation status of the oocytes at the time of cumulus cell removal and ICSI. The fertilization and pregnancy rates after ICSI were analyzed and compared among the study groups based on the maturation status of the retrieved oocytes. Results: The retrieval of only immature oocytes was associated with a significant decrease in the fertilization rate ($76.1%{\pm}37.3%$ vs. $49.0%{\pm}49.1%$, $66.7%{\pm}48.7%$; group I vs. group II, group III, respectively) and the average number of transferred embryos ($1.5{\pm}0.7$ vs. $1.1{\pm}0.4$, $1.1{\pm}0.6$). The cycle cancellation rate was significantly higher when only immature oocytes were retrieved. The clinical pregnancy rate decreased significantly when the transferred embryos had originated from immature oocytes (16.9% vs. 10.3%, 1.2%). Conclusion: In ICSI cycles, the fertilization potential and pregnancy potential of the immature oocytes retrieved in ICSI cycles were inferior to those of mature oocytes. Therefore, increasing the number of injectable oocytes and transferrable embryos by using immature oocytes after their spontaneous in vitro maturation does not necessarily improve pregnancy outcomes.

Application of Response Surface Methodology (RSM) on Adsorption of Cs Ion in Aqueous Solution with Zeolite X Synthesized from Coal Fly Ash (석탄비산재로 합성한 제올라이트 X에 의한 수중의 Cs 이온 흡착에 반응표면분석법 적용)

  • Lee, Chang-Han;Lee, Min-Gyu
    • Clean Technology
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    • v.23 no.4
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    • pp.413-420
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    • 2017
  • The batch experiments and response surface methodology (RSM) have been applied to the investigation of the Cs adsorption with zeolite X synthesized using coal fly ash generated from the thermal power plant. Regression equation formulated for Cs adsorption was represented as a function of response variables. The model was highly relevant because the decision coefficient ($r^2$) was 0.9630. It was confirmed from the statistical results that the removal efficiency of Cs was affected by the order of experimental factors as pH > Cs concentration > temperature. The adsorption kinetics were more accurately represented by a pseudo second-order model. The maximum adsorption capacity calculated from the Langmuir isotherm model was $151.52mg\;g^{-1}$ at 293 K. Also, according to the thermodynamic parameters calculated from Vant Hoff equation, it could be confirmed that the adsorption reaction was an endothermic reaction and a spontaneous process.

Adsorption Characteristics of 2,4-Dichlrophenol by Magnetic Activated Carbon Prepared from Waste Citrus Peel (폐감귤박으로 제조한 자성 활성탄을 이용한 2,4-디클로로페놀의 흡착특성)

  • Kam, Sang-Kyu;Lee, Min-Gyu
    • Applied Chemistry for Engineering
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    • v.29 no.4
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    • pp.388-394
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    • 2018
  • The removal of 2,4-dichlorophenol (2,4-dichlorophenol, 2,4-DCP) in aqueous solution was studied using the magnetic activated carbon (MAC) prepared from waste citrus peel. The adsorption characteristics of 2,4-DCP by MAC were investigated by varying the contact time, MAC dose, solution temperature, pH and 2,4-DCP concentration. The isothermal adsorption data were well explained by the Langmuir isotherm model equation and the maximum adsorption capacity calculated from the Langmuir isotherm equation was 312.5 mg/g. The adsorption kinetic data were well described by the pseudo-second-order reaction equation. The intraparticle diffusion model data indicated that both the film and intraparticle diffusion occur simultaneously during the adsorption process. The thermodynamic parameters of ${\Delta}H^o$ and ${\Delta}G^o$ have positive and negative values, respectively, indicating that the adsorption of 2,4-DCP by MAC is a spontaneous endothermic reaction. After the adsorption experiment was completed, the used MAC could be easily separated by an external magnet.