• 제목/요약/키워드: Removal technique

검색결과 949건 처리시간 0.027초

Dewaxing(탈랍) 기술의 최근의 발전된 기술 내용 소개 (Introduction to the recent development of the dewaxing technique.)

  • 나윤호
    • 기술사
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    • 제15권3호
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    • pp.33-36
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    • 1982
  • Dewaxing Technique was reconized as the removal of waxy materials from the lubriating distillates for the purpose of the improvement of the low temperative fluidity of the lubricating oils. Recently this technique is developed not only the removal of the waxy materials but the reformation of the waxy materials which does not effect the low temperative fluidity of the lutricating oils. The cutalytic dewaxing technique is developed is this letter direction. And so I insist here the defintion of dewaxing technique must be defined as the technique of the removal and reforming technique of the waxy materials which effect the fluidity of the lubricating oils.

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폐금속 광산지역 농경지 납, 아연 오염 토양의 중금속 고도선별 (Enhanced Separation Technique of Heavy Metal (Pb, Zn) in Contaminated Agricultural Soils near Abandoned Metal Mine)

  • 박찬오;김진수;서승원;이영재;이재영;박미정;공성호
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제18권7호
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    • pp.41-53
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    • 2013
  • The study is to propose the optimal separation technique of heavy metals (Pb and Zn) contaminated in soil for improving the removal efficiency by various applicable techniques. The heavy metal contaminated soil samples near abandoned mine X-1 and X-2 were used for the study. Firstly, the wet classification process was shown more than 80% of removal efficiency for lead and zinc. Meanwhile, the magnetic separation process was shown low removal efficiency for lead and zincs because those heavy metals were non-magnetic materials. For the next step, the flotation separation process was shown approximately 24.4% of removal efficiency for zinc, while the gravity concentration process was shown approximately 57% of removal efficiency for lead, and 19.9% of removal efficiency for zinc, respectively. Therefore, zinc contaminated in soil would be effectively treated by the combination technique of the wet classification and the flotation technique. Meanwhile, lead contaminated in soil would be effectively treated by the combination technique of the wet classification process and the flotation process. Furthermore, the extraction of organic matter was shown more effective with aeration, 3% of hydrogen peroxide and 3% of lime such as calcium hydroxide.

Fiber-reinforced composite post removal using guided endodontics: a case report

  • Changgi Cho ;Hyo Jin Jo ;Jung-Hong Ha
    • Restorative Dentistry and Endodontics
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    • 제46권4호
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    • pp.50.1-50.8
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    • 2021
  • Although several techniques have been proposed to remove fiber-reinforced composite (FRC) post, no safe and efficient technique has been established. Recently, a guided endodontics technique has been introduced in cases of pulp canal obliteration. This study describes 2 cases of FRC post removal from maxillary anterior teeth using this guided endodontics technique with a dental operating microscope. Optically scanned data set from plaster cast model was superimposed with the data set of cone-beam computed tomography. By implant planning software, the path of a guide drill was selected. Based on them, a customized stent was fabricated and utilized to remove the FRC post. Employing guided endodontics, the FRC post was removed quickly and safely with minimizing the loss of the remaining tooth structure. The guided endodontics was a useful option for FRC post removal.

소아 안면열상 환자의 치료에 있어서 유용한 봉합술 (Convenient Suture Technique for Pediatric Facial Lacerations)

  • 김준형;권순범;어수락;조상헌
    • Archives of Plastic Surgery
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    • 제37권4호
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    • pp.496-498
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    • 2010
  • Purpose: Lacerations requiring formal wound closure compose a significant number of all childhood injuries presenting to the emergency department. The problem with conventional suture technique are that suture removal is quite cumbersome, especially in children. Unwanted soft tissue damage can result in the process of suture removal, which calls for sedation, stressful for both medical personnel and child. The purpose of this study is to introduce the convenient suture technique for pediatric facial lacerations. Methods: Children under the age of four, presenting to the emergency department with facial lacerations were enrolled in the study. From March 2008 to June 2009, 63 patients (41 males and 22 females) with an average age of 1.4 years were treated with our convenient suture technique using utilized a loop suspended above a double, flat tie. Clean, tension free wounds were treated with our technique, wounds with significant skin defect and concomitant fractures were excluded. Results: The Patients were followed-up in 1, 3 and 5 days postoperatively. On the third hospital visit, suture removal was done by simply cutting the loop suspended above the wound margin and gently pulling the thread with forceps. There were no significant differences in the rates of infection and dehiscence compared with conventional suture technique. Conclusion: The use of our technique was to be simple with similar operative time compared with conventional suture technique. Removal of suture materials were easy without unwanted injuries to the surrounding tissue which resulted in less discomfort for the patient and greater parental satisfaction, minimized the complications. It can be considered as a viable alternative in the repair of pediatric facial lacerations.

Straight lift technique as an alternative to surgical extraction of an intact, partially impacted mesioangular mandibular third molar

  • Rai, Anshul J.;Kumar, Jitendra;Lal, Babu;Shakti, Prateek
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제48권5호
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    • pp.326-328
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    • 2022
  • Impacted mandibular third molar removal is the most common procedure performed by oral and maxillofacial surgeons. An array of alternative procedures have been suggested, like operculectomy in cases of pericoronitis and coronectomy in certain cases. However, these procedures pose several disadvantages, and we propose a relatively non-invasive 'straight lift technique'. This technique is specifically useful in straightening abnormally positioned mesioangular third molars as a substitute of complete removal. This can improve tooth function, eliminate the need for surgical intervention, and reduce the risk of complications associated with third molar removal.

Microabrasion Techinique을 이용한 치아변색의 치료증례 (Treatment of Tooth Discoloration using Microabrasion Technique : Case Report)

  • 박미령;김종수;김용기
    • 대한소아치과학회지
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    • 제24권3호
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    • pp.511-517
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    • 1997
  • Tooth discoloration detracts from one's appearance and influences self-image and it is particularly true in children. Therefore, pediatric dentists are required to treat tooth discoloration manifested in children for the normal development of their psycosocial health. Three treatment modalities are currently availabler for the removal of a variety of intrinsic stains from vital teeth. These are enamel microabrasion technique using hydrochloric acid, office bleaching and home bleaching technique with carbamide. Microabrasion technique has several advantages over bleaching in that it is easy to accomplish and does not require multiple office visits or the expensive instruments and the color change seems to be permanent after treatment. The process relies on decalcification, a softening with HCl and then removal of the enamel containing the stain with rubbing. Due to the mechanism of stain removal, this method is indicated for the removal of superficial enamel stains or disc oloration only. We report four successfully treated cases by enamel microabrasion using 15% HCl and pumice. Entire clinical steps are described in detail with some discussions on the outcome.

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Minimally Invasive Removal of an Intradural Cervical Tumor : Assessment of a Combined Split-Spinous Laminectomy and Quadrant Tube Retractor System Technique

  • Kwak, Young-Seok;Kim, Kyoung-Tae;Cho, Dae-Chul;Kim, Young-Baeg
    • Journal of Korean Neurosurgical Society
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    • 제52권4호
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    • pp.427-431
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    • 2012
  • Conventional laminectomy is the most popular technique for the complete removal of intradural spinal tumors. In particular, the central portion intramedullary tumor and large intradural extramedullary tumor often require a total laminectomy for the midline myelotomy, sufficient decompression, and adequate visualization. However, this technique has the disadvantages of a wide incision, extensive periosteal muscle dissection, and bony structural injury. Recently, split-spinous laminectomy and tubular retractor systems were found to decrease postoperative muscle injuries, skin incision size and discomfort. The combined technique of split-spinous laminectomy, using a quadrant tube retractor system allows for an excellent exposure of the tumor with minimal trauma of the surrounding tissue. We propose that this technique offers possible advantages over the traditional open tumor removal of the intradural spinal cord tumors, which covers one or two cervical levels and requires a total laminectomy.

초음파동전기세척 복합기법에 의한 오염부지 복원기술

  • 정하익;김상근;송봉준;강동우;이경국
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.183-185
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    • 2004
  • In this study, the combined electrokinetic and ultrasonic remediation technique, ultrasonically enhanced electrokinetic technique, was studied for the removal of heavy metal and organic substance in contaminated soils. The electrokinetic technique has been applied to remove mainly the heavy metal and the ultrasonic technique has been to remove mainly organic substance in contaminated soil. The laboratory soil flushing tests combined electrokinetic and ultrasonic technique were conducted using specially designed and fabricated devices to determine the effect of these both techniques. A series of laboratory experiments involving the simple, electrokinetic, ultrasonic, and electrokinetic & ultrasonic flushing test were carried out. A soil admixed with sand and kaolin was used as a test specimen, and Pb and ethylene glycol were used as contaminants of heavy metal and organic substance. An increase in out flow, permeability and contaminant removal rate was observed in electrokinetic and ultrasonic flushing tests. Some practical implications of these results are discussed in terms of technical feasibility of in situ implementation of electrokinetic ultrasonic remediation technique.

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Heavy metals removal from aqueous solution through micellar enhanced ultrafiltration: A review

  • Yaqub, Muhammad;Lee, Seung Hwan
    • Environmental Engineering Research
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    • 제24권3호
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    • pp.363-375
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    • 2019
  • Micellar-enhanced ultrafiltration (MEUF) is a surfactant-based separation technique and has been investigated for the removal of heavy metals from wastewater. The performance of heavy metals removal from wastewater through MEUF relies on membrane characteristics, surfactant properties, various operational parameters including operating pressure, surfactant and heavy metal concentration, pH of the solution, temperature, and presence of dissolved solutes and salts. This study presents an overview of literature related to MEUF with respect to the all significant parameters including membranes, surfactants, operating conditions and MEUF hybrid processes. Moreover, this study illustrates that MEUF is an adaptable technique in various applications. Nowadays water contamination caused by heavy metals has become a serious concern around the globe. MEUF is a significant separation technique in wastewater treatment that should be acknowledged, for the reason that removal of heavy metals contamination even at lower concentrations becomes achievable, which is evidently made known in the presented review. Hybrid processes presented the better results as compared to MEUF. Future studies are required to continue the experimental work with various combinations of surfactant and heavy metals, and to investigate for the treatment of concentrated solutions, as well as for real industrial wastewater.

Simultaneous removal of dissolved TCE and chromate using micellar-enhanced ultrafiltration

  • 이율리아;김호정;백기태;김보경;양지원
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.413-416
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    • 2003
  • Micellar enhanced ultrafiltration(MEUF) is a surfactant-based separtaion technique which can remove dissolved organics or multivalent ions from water. In this study, trichloroethylene(TCE) and chromate were simultaneouly removed using MEUF and cetyltrimethylammoniun chloride (CPC) was used as a surfactant. The removal efficiency of chromate was 99% and that of TCE was more than 80%. The presence of TCE or chromate did not affect removal efficiency of each pollutants because the predominat mechanism of TCE and chromate are different.

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