• 제목/요약/키워드: Spontaneous removal

검색결과 143건 처리시간 0.031초

Polysulfone에 Di-(2-ethylhexyl)phosphoric acid(D2EHPA)와 tri-butyl-phosphate(TBP)를 고정화하여 제조한 고체상 추출제에 의한 Sr(II)의 제거특성 (Removal Characteristics of Sr(II) by Solid-Phase Extractant Prepared by Immobilizing Di-(2-ethylhexyl)phosphoric acid (D2EHPA) and Tri-butyl-phosphate (TBP) in Polysulfone)

  • 감상규;전진우;이민규
    • 한국환경과학회지
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    • 제24권3호
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    • pp.267-274
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    • 2015
  • The feasibility of PS-D2EHPA/TBP beads prepared by immobilizing two extractants D2EHPA and TBP in polysulfone to remove Sr(II) from aqueous solution was investigated in batch system. Batch experiments were carried out to study equilibrium isotherms, kinetics, and thermodynamics. Equilibrium data were fitted using Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich equation models at temperatures of 298 K, 313 K, and 328 K. The removal capacity of Sr(II) by PS-D2EHPA/TBP beads obtained from Langmuir model was 2.41 mg/g at 298 K. The experimental data were well represented by pseudo-second-order model. The removal process of Sr(II) by PS-D2EHPA/TBP beads prepared in this study was found to be feasible, endothermic, and spontaneous.

Polysulfone으로 carbon nanotubes (CNT)와 di-(2-ethylhexyl)-phosphoric acid (D2EHPA)를 고정화한 PSf/D2EHPA/CNT 비드에 의한 Cu(II)의 제거특성 (Removal Characteristics of Cu(II) by PSf/D2EHPA/CNT Beads Prepared by Immobilization of Carbon Nanotubes (CNT) and Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) on Polysulfone (PSf))

  • 이창한;이민규
    • 한국환경과학회지
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    • 제25권11호
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    • pp.1485-1491
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    • 2016
  • PSf/D2EHPA/CNT beads were prepared by immobilizing di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and carbon nanotubes (CNT) on polysulfone (PSf) and used to remove Cu(II) from aqueous solutions. Optimum pH was in the range of 4 to 6. The removal kinetic of Cu(II) by the prepared PSf/D2EHPA/CNT beads was mainly governed by internal diffusion, and the diffusion coefficient of Cu(II) by PSf/D2EHPA/CNT beads was found to be $2.19{\times}10^{-4}{\sim}2.64{\times}10^{-4}cm^2/s$. The Langmuir isotherm model predicted the experimented data well. The maximum removal capacity of Cu(II) obtained from this isotherm was 7.32 mg/g. Calculated thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ showed that the adsorption of Cu(II) ions onto PSf/D2EHPA/CNT beads was feasible, spontaneous and endothermic at 293-323 K.

화산재에 의한 수용액의 납 이온 흡착특성 (Adsorption characteristics of lead ion in aqueous solution by volcanic ash)

  • 김미연;소명기;김영관
    • 상하수도학회지
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    • 제25권3호
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    • pp.359-366
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    • 2011
  • The feasibility of using volcanic ash for lead ion removal from wastewater was evaluated. The adsorption experiments were carried out in batch tests using volcanic ash that was treated with either NaOH or HCl prior to the use. Volcanic ash dose, temperature and initial Pb(II) concentration were chosen as 3 operational variables for a $2^3$ factorial design. Ash dose and concentration were found to be significant factors affecting Pb(II) adsorption. The removal of Pb(II) was enhanced with increasing volcanic ash dose and with decreasing the initial Pb(II) concentration. Pb(II) adsorption on the volcanic ash surface was spontaneous reaction and favored at high temperatures. Calculation of Gibb's free energy indicated that the adsorption was endothermic reaction. The equilibrium parameters were determined by fitting the Langmuir and Freundlich isotherms, and Langmuir model better fitted to the data than Freundlich model. BTV(base-treated volcanic ash) showed the maximum adsorption capacity($Q_{max}$) of 47.39mg/g. A pseudo second-order kinetic model was fitted to the data and the calculated $q_e$ values from the kinetic model were found close to the values obtained from the equilibrium experiments. The results of this study provided useful information about the adsorption characteristics of volcanic ash for Pb(II) removal from aqueous solution.

원발성 흉골결핵의 외과적 치험 -1례 보고- (Primary Sternal Tuberculosis with Spontaneous Fracture Treated by Resection and Reconstruction -A Case Report-)

  • 배상일;김미혜;오태윤;장운하
    • Journal of Chest Surgery
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    • 제31권2호
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    • pp.190-193
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    • 1998
  • 본 강북삼성병원 흉부외과에서는 병적골절이 동반된 원발성 흉골결핵을 치험 하였다. 22세된 여자환자가 특별한 외상이없이 발생한 흉골부위의 통증 및 골절로 입원 하였다. 입원당시 시행한 흉부단순촬영 및 전산화단층촬영상 흉골의 괴사소견과 연부조직의 부종이 관찰되었다. 세침세포검사상 냉농양을 동반한 결핵성 골수염으로 진단되어 술전 항결핵 치료후 수술을 시행하였다. 수술시 흉골중앙부위의 골괴사 및 다발성 누공을 확인하였으며, 골괴사 부위를 제거한후 환자의 장골능을 골이식 하였다. 병리조직학적 결과는 결핵성 골수염의 소견 및 치즈양괴사를 보였다. 술후 경과는 양호 하였으며, 2개월동안의 추적검사상 흉골의 불안정은 관찰되지 않았다.

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자연성 기흉으로 인한 대량의 혈흉 (Massive hemothorax resulting from spontaneous pneumothorax)

  • 홍지연;김수완
    • Journal of Medicine and Life Science
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    • 제17권1호
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    • pp.16-20
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    • 2020
  • Spontaneous hemopneumothorax is a rare disease, and it can cause life threatening condition. It is characterized by the accumulation of more than 400 mL of blood and air in the pleural cavity without any other apparent causes. A previously healthy 22-year-old female patient presented with acute chest pain and dyspnea. Chest X-ray and computed tomography revealed a massive hemopneumothorax in the left hemithorax. The images showed a completely collapsed left lung with right-sided tracheal deviation, several pleural adhesion bands, and fluid collection with air-fluid level. We emergently performed a closed thoracostomy, and then 560 mL of fresh bloods were initially drained. We considered an emergent video-assisted thoracoscopic surgery for pulmonary wedge resection and bleeding control because of the massive hemothorax. However, the patient's vital signs were stabilized after blood transfusion and supportive cares for re-expansion pulmonary edema. The patient discharged from the hospital on 11th in-hospital day after removal of the chest tube, and there had not been any recurrence of the pneumothorax for 10 months. We suggest that treatment strategy should be decided upon individually based on the patient's condition and clinical course of the disease.

자발성 척수내혈종 - 증례보고 - (Spontaneous Hematomyelia - Case Report -)

  • 황정현;성주경;황성규;함인석;박연묵;김승래
    • Journal of Korean Neurosurgical Society
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    • 제29권3호
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    • pp.411-419
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    • 2000
  • Hematomyelia is an extremely rare condition that cause severe neurological symptoms. We reported 4 cases of spontaneous hematomyelia, two cases of cavernous angioma and two cases of hematoma. In all patients, the clinical course was progressive ; motor and sensory abnormalities below the lesion and voiding difficulties were the common presenting symptom complex. The preoperative diagnosis was made by magnetic resonance imaging and the all patients underwent surgical exploration. Complete removal of hematoma was done in 3 patients and complete evacuation after aspiration of hematoma were performed in one patients. Neurological function did not worsen postoperatively in any patients. The early diagnosis with magnetic resonance imaging and immediate surgical treatment of the hematoma and the associated vascular malformation are considered to be the best way to halt the progression of the disease.

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Spontaneous Regression of Eyelid Histiocytoma in a Maltese Dog

  • Kim, Boyun;Lim, Jaegook;Shim, Jae-ho;Seo, Kangmoon;Kang, Seonmi
    • 한국임상수의학회지
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    • 제39권3호
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    • pp.121-125
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    • 2022
  • A 1-year-old neutered male Maltese dog was presented with a mass on the upper eyelid of the left eye (OS). A pinkish and alopecic mass was located in the nasal portion of the upper eyelid of OS. The mass was firmly attached to the eyelid and round-shaped with a diameter of 11 mm. Any spread to conjunctiva was not identified. On a cytological examination, cutaneous histiocytoma was confirmed, with the presence of small lymphocytes indicating later regression stage. The patient received no treatment and complete regression of the mass was verified 2 months later. The cytological examination was helpful for the diagnosis and staging of cutaneous histiocytoma. Canine eyelid histiocytoma can regress spontaneously, and thus medical or surgical treatment for removal should be considered carefully.

맹출 지연 영구치의 자발적 맹출 유도 : 증례보고 (DELAYED TOOTH ERUPTION GUIDED BY SPONTANEOUS TOOTH ERUPTION: CASE REPORT)

  • 권지훈;박호원;이주현;서현우
    • 대한소아치과학회지
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    • 제34권4호
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    • pp.694-699
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    • 2007
  • 정상적인 맹출 시기는 종족, 인종, 성별과 개인적인 요소에 의해 결정되며, 만약 정상적인 맹출 시기에서 두드러지게 벗어날 경우 맹출 지연이라고 한다. 영구치의 맹출 지연 원인은 다양하며, 발생 시 치열 및 악궁에 부정적인 영향을 줄 수 있어 조기진단 및 치료가 중요하다. 본 증례들에서는 치아종 및 치아발육부전 그리고 낭종으로 인한 맹출지연을 보이는 각각의 환자에 대해 맹출 방해 인자의 제거와 맹출 공간의 형성 및 유지만으로 자발적 맹출을 이룰 수 있었기에 보고하는 바이다.

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LMS 적응필터를 이용한 직교 함수 기반의CPR 잡음 제거 알고리즘 설계 (Design of CPR Artifact Removal Algorithm Based on Orthogonal Function using LMS Adaptive Filter)

  • 임은호;남동훈;명현석;강동원;전대근;윤영로;이경중
    • 대한의용생체공학회:의공학회지
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    • 제37권5호
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    • pp.153-160
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    • 2016
  • This study proposes an algorithm for removal of CPR artifact in order that automated external defibrillator (AED) can effectively diagnose ECG rhythm during cardiopulmonary resuscitation (CPR). Current AED required to interrupt chest compression for reliable rhythm analysis to avoid the effect of artifacts produced by CPR. However even temporarily interruption of chest compression during CPR adversely affects the probability of restoration of spontaneous circulation (ROSC) and survival after the delivery of the shock. Therefore, we proposed a method for removal of CPR artifacts using least mean square (LMS) filter. The removal of the CPR artifacts would enable compressions to continue during AED rhythm analysis, thereby increasing the likelihood of resuscitation success. It was tested on 31 segments of shockable and 300 segments of non-shockable ECG signals recorded from three pigs during CPR. In the result, sensitivity (Se) and specificity (Sp) analysis on the test segments showed values of Se = 3.2%, Sp = 66.0% and Se = 96.8%, Sp = 98.7% in the case of unfiltered and filtered signals during CPR. In conclusion, it was shown that the proposed method can be a useful tool to exactly diagnose the ECG rhythm during the CPR.

수용액 중 Orange II 흡착 제거를 위한 우모폐기물의 이용가능성 (Effectiveness of Feather Waste for Orange II Removal from Aqueous Solutions)

  • 박수연;유지연;손홍주
    • 한국환경과학회지
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    • 제27권9호
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    • pp.743-751
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    • 2018
  • The objective of this study was to investigate the adsorption potential of chicken feathers for the removal of OrangeII (AO7) from aqueous solutions. Batch experiments were performed as a function of different experimental parameters such as initial pH, reaction time, feather dose, initial OrangeII concentration and temperature. The highest OrangeII uptake was observed at pH 1.0. Most of the OrangeII was adsorbed at 2 h and an adsorption equilibrium was reached at 6 h. As the amount of chicken feather was increased, the removal efficiency of OrangeII increased up to 99%, but its uptake decreased. By increasing the initial concentration and temperature, OrangeII uptake was increased. The experimental adsorption isotherm exhibited a better fit with the Langmuir isotherm than with the Freundlich isotherm, and maximum adsorption capacity from the Langmuir constant was determined to be 0.179244 mmol/g at $30^{\circ}C$. The adsorption energy obtained from the Dubinin-Radushkevich model was 7.9 kJ/mol at $20^{\circ}C$ and $30^{\circ}C$ which indicates the predominance of physical adsorption. Thermodynamic parameters such as ${\Delta}G^0$, ${\Delta}H^0$, and ${\Delta}S^0$ were -12.28 kJ/mol, 20.64 kJ/mol and 112.32 J/mol K at $30^{\circ}C$, respectively. This indicates that the process of OrangeII adsorption by chicken feathers was spontaneous and endothermic. Our results suggest that as a low-cost biomaterials, chicken feather is an attractive candidate for OrangeII removal from aqueous solutions.