• 제목/요약/키워드: comminution

검색결과 59건 처리시간 0.028초

Operative Treatment with Intramedullary Fibular Strut Allograft for Osteoporotic Proximal Humerus Fracture

  • Chun, Yong-Min;Lee, Wonyong
    • Clinics in Shoulder and Elbow
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    • 제20권2호
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    • pp.95-99
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    • 2017
  • Background: The purpose of this study was to investigate the clinical and radiological outcomes of locking plate fixation with fibular strut allograft to manage unstable osteoporotic proximal humerus fractures. Methods: We retrospectively reviewed 15 patients who underwent open reduction and locking plate fixation with fibular strut allograft for osteoporotic proximal humerus fracture between July 2011 and June 2015. For functional evaluation, we evaluated visual analogue scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, University of California Los Angeles (UCLA) shoulder score, and active range of motion. For radiological evaluation, shoulder true anteroposterior (AP) and AP in $20^{\circ}$ external rotation, as well as the axillary view were taken at two weeks, six weeks, three months, six months, and one year. And the neck-shaft angle was measured on the AP view in $20^{\circ}$ external rotation view. Results: At the one-year follow-up, mean VAS pain score and all shoulder scores, including ASES score and UCLA shoulder score, exhibited satisfactory clinical outcomes. All patients obtained bone union between three and six months post-procedure. Moreover, the mean immediate postoperative neck-shaft angle was $138^{\circ}{\pm}4^{\circ}$, and at one-year follow-up, the neck shaft angle was $137^{\circ}{\pm}5^{\circ}$. There was no significant difference between the preoperative and postoperative values (p=0.105). Conclusions: For the unstable two-part and three-part osteoporotic proximal humerus fractures with medial calcar comminution, the use of fibular strut allograft with locking plate fixation was effective in maintaining the initial status of reduction and exhibiting the satisfactory functional and radiological outcomes.

이산요소법을 이용한 다단 임팩트 파쇄기 내 입자 거동 모사 (Simulation of Particle Behaviors within a Multi-stage Impact Crusher using Discrete Element Method)

  • 유명열;이훈
    • 자원리싸이클링
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    • 제27권3호
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    • pp.86-92
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    • 2018
  • 건설폐기물 발생량은 매년 꾸준하게 상승하고 있으며 재활용촉진 법이 재정되어있지만 콘크리트-시멘트페이스트 간의 단체분리 저하로 인해 높은 흡수율과 낮은 밀도로 순환골재 품질 기준에 제시되어 있는 콘크리트용 순환골재로서 사용되기 어려운 실정이다. 따라서 본 연구에서는 순환골재의 품위 향상에 필수적인 몰타르 제거를 위하여 다단형 임팩트 크러셔를 사용하였다. 장비의 특성을 분석하는데 있어서 전산 모사 방법인 DEM (Discrete Element Method)를 이용하여 영상 분석을 이용한 내부 입자의 거동 특징과, 투입 입자-장비의 각 부분에 발생하는 에너지의 스펙트럼을 분석하였다. 내부벽, 가이더 및 임펠러의 힘의 크기를 발생하는 횟수에 따라 스펙트럼을 생성하여 효과적인 분석이 가능하였다. 효과적인 박리현상을 발생시키기 위하여, 저에너지 그룹의 충돌 횟수(L)와 파분쇄를 발생시키는 고에너지 그룹의 충돌 횟수(H)의 비율을 토대로 회전속도 900RPM의 조건이 적절함을 확인하였다.

분쇄가 심한 Ruedi-Allgower II, III형의 개방성 경골 천정 골절에서 단계적 수술의 결과 (Result of Staged Operation in Ruedi-Allgower Type II and III Open Tibia Pilon Fractures with Severe Comminution)

  • 최귀연;이준영;장현웅;김영욱
    • 대한족부족관절학회지
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    • 제23권3호
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    • pp.110-115
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    • 2019
  • Purpose: This study analyzed the clinical and radiological results of Reudi-Allgower type II and III open tibia pilon fracture patients who underwent plate fixation after the recovery of a soft tissue injury after external fixation. Materials and Methods: From 2010 to 2015, this study analyzed 14 patients who were treated for open tibial pilon fractures and could be followed up at least one year. The mean age was 49 years and the average follow-up period was 19 months. An emergency operation was performed for external fixation and open wounds, and secondary surgery was performed for definitive fixation using a plate. The radiological and clinical evaluations were analyzed retrospectively. Complications, such as post-traumatic osteoarthritis and wound infections were also analyzed. Results: The mean duration between two-staged surgery was 21 days and the mean bone union time was 9.2 months. Three cases of delayed union and one case of nonunion were reported. The malunion did not occur in all cases. The average American Orthopaedic Foot and Ankle Society (AOFAS) score was 68 points. A limitation of the ankle motion occurred in all cases. In four cases, wound infections due to initial open wounds occurred; one patient underwent a below the knee amputation due to chronic osteomyelitis. Post-traumatic arthritis occurred in 10 cases. Conclusion: Severe comminuted tibial plateau open fractures of Reudi-Allgower type II and III, which are high-energy injuries that result in extensive soft tissue damage, have a higher incidence of complications, such as ulcer problems and osteomyelitis, than closed tibia plateau fractures. Post-traumatic arthritis is the most common complication of tibia plateau open fractures, and staged surgery is recommended because of the relatively satisfactory clinical results.

Estimation of Moisture Content in Comminuted Miscanthus based on the Intensity of Reflected Light

  • Cho, Yongjin;Lee, Dong Hoon
    • Journal of Biosystems Engineering
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    • 제40권3호
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    • pp.296-304
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    • 2015
  • Purpose: The balance between miscanthus production and its cost effectiveness depends greatly on its moisture content during post processing. The objective of this research was to measure the moisture content using a non-destructive and non-contact methodology for in situ applications. Methods: The moisture content of comminuted miscanthus was controlled using a closed chamber, a humidifier, a precision weigher, and a real-time monitoring software developed in this research. A CMOS sensor equipped with $50{\times}$ magnifier lens was used to capture magnified images of the conditioned materials with moisture content level from 5 to 30%. The hypothesis is that when light is incident on the comminuted particles in an inclined manner, higher moisture content results in light being reflected with a higher intensity. Results: A linear regression analysis for an initiative hypothesis based on general histogram analysis yielded insufficient correlations with low significance level (<0.31) for the determination coefficient. A significant relationship (94% confidence level) was determined at level 108 in a reverse accumulative histogram proposed based on a revised hypothesis. A linear regression model with the value at level 108 in the reverse accumulative histogram for a magnified image as the independent variable and the moisture content of comminuted miscanthus as the dependent variable was proposed as the estimation model. The calibrated linear regression model with a slope of 92.054 and an offset of 32.752 yielded 0.94 for the determination coefficient (RMSE = 0.2%). The validation test showed a significant relationship at the 74% confidence level with RMSE 6.4% (n = 36). Conclusions: To compensate the inconsistent significance between calibration and validation, an estimation model robust against various systematic interferences is necessary. The economic efficiency of miscanthus, which is a promising energy resource, can be improved by the real-time measurement of its crucial material properties.

Review on Rice Flour Manufacturing and Utilization

  • Kim, Myoung Ho
    • Journal of Biosystems Engineering
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    • 제38권2호
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    • pp.103-112
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    • 2013
  • Background: The Korean government launched a project in 2008, where the amount of rice used as raw ingredient in rice-based foods in 2012 was planned to increase up to 10% (470,000 ton) of the total rice production through developing various new rice-based processed foods and their commercial manufacturing technology. Among the four major rice-based processed foods, rice cakes and noodles need rice flour as their main raw ingredient. Technology in rice flour utilization and manufacturing is far behind than the technology pertinent to wheat flour in many subject areas. Purpose: This review aims to provide information on rice flour utilization and manufacturing with some fundamental subjects in the area of size reduction. Results: A variety of food items including bread, noodle, cake, cookie, muffin, pre-mix, beverage, vinegar, surimi, and artificial meat have found rice flour as their raw ingredient. Rice bread made out of 100% rice flour has been developed and is now sold in retail stores. Various noodle products made from rice flour are also on the market. Issues on product definition and labeling regulation about rice flour content of the products were explored. Generalized grinding equations available in the literature were seldom used in practice; instead, it has been a general practice to develop empirical equations from test milling data. Introductory remarks on three popular particle size measurement methods (sieving, Coulter counter, light diffraction) were explained. Mathematical expressions frequently used to describe particle size distribution and to correlate cumulative quantity of particles with particle size were represented. Milling methods used in producing rice flour were described along with their advantages and disadvantages. Because of their profound effect on functional properties of the rice flour, four rice flour milling equipments used at both laboratory experiments and commercial manufacturing plants were discussed.

전완골 분절의 전위 이식술 (Segmented Ulnar Transposition to Defect of Ipsilateral Radius in the Forearm)

  • 정덕환;한수홍;이재훈;권부경
    • Archives of Reconstructive Microsurgery
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    • 제16권2호
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    • pp.125-132
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    • 2007
  • Introduction: Ulna is nearly equal to radius in function and bony architecture and strength in forearm. But in lower extremity, fibula is 1/5 of tibia in anatomic and functional point so we can find fibula transposition is commonly used in defect of tibia. We cannot find other article about segmental forearm bone transposition in man. The purpose of this study was to report our clinical and functional result of undergoing segmented transposition of ipsilateral ulna with its own vascular supply in defect of radius in 6 cases. Material and method: From June 1994 to October 2007, 7 segmented bone transpositional grafts in forearm were performed in Kyung Hee Medical Center. The distribution of age was from 20 years old to 73 years old. There was male in 6 cases and female in 1 case. The causes of operation were giant cell tumor in 1 case and traumatic origin in 6 cases; it was nonunion in 2 cases and fracture with severe comminution in 4 cases. Ipsilaterally segmented ulna keeping its own vascular supply was transported to defect of radius in severe traumatic patients and one patient whose tumor in radius had been excised. Transported ulna was fixed to proximal and distal radius remnants by plate and screw. In one case with giant cell tumor, transported ulna was connected to radius across wrist joint as wrist joint fusion. Joint preserving procedures were performed in 6 cases with crushing injury of radius. Results: We could obtain solid bony union in all cases and good functional results. The disadvantage was relative shortening of forearm, but we could overcome this problem. Conclusion: We think that ipsilateral segmented ulna transposition keeping its own vascular supply to radius can be perfomed with one of procedures in cases with wide defect in radius.

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Ovadia와 Beals 제2형 또는 3형 경골 천정 골절의 제한적 내고정술을 이용한 치료 (Limited internal fixation for the treatment of the Ovadia and Beals type II or III Pilon fracture)

  • 김형천;김광열;임문섭;김진형;권준형
    • 대한족부족관절학회지
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    • 제7권2호
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    • pp.250-257
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    • 2003
  • Purpose: Pilon fracture is caused by high energy and axial compression forces, and it is often associated with severe comminution and soft tissue injury. Recently, limited internal fixation of this fracture may avoid the soft tissue complications associated with formal open reduction and internal fixation and avoid incongruity of joint margin associated with conservative treatment. We have treated Ovadia and Beals type II or III pilon fracture with limited internal fixation and the results were satisfactory. Materials and Methods: We analyzed 15 cases of Ovadia and Beals type II or III fractures who were treated by limited internal fixation(K-wire or screw fixation) from January 1995 to December 2000. The average follow up period was 20 months(range, 12 to 38 months). According to the Ovadia and Beals classification, seven cases were type II, and eight cases were type III. Radiographic results were assessed by Ovadia and Beals criteria. We also assessed the functional results by Mast and Teipner criteria. Results: Radiographic results showed good in 67% and fair in 33% of cases. Clinical results showed good in 73% and fair in 27% of cases. There were no complications such as wound infection and skin necrosis, but traumatic arthritis were 2 cases. Conclusion: Pilon fractures are high energy injuries with significantly associated soft tissue damage and traumatic arthritis. Limited internal fixation offers good solution to Ovadia and Beals type II or III fracture.

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Oil Palm Frond의 반탄화를 통한 연료화 연구 (The Fuelization Study on the Oil Palm Frond Through Torrefaction)

  • 이명석;정광식;정상진;이관영
    • Korean Chemical Engineering Research
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    • 제51권4호
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    • pp.465-469
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    • 2013
  • 본 연구는 반탄화된 OPF(oil palm fronds)의 연료로써 이용가능성을 알아보았다. OPF는 200, 250, 300, $350^{\circ}C$에서 각각 1시간과 2시간 동안 반탄화를 진행하였다. 반탄화된 OPF는 온도가 높아짐에 따라 그리고 반탄화 시간이 증가됨에 따라 발열량이 증가하였다. 또한, 반탄화 시간보다는 반탄화 온도가 더 중요한 요소였다. 하지만 반탄화 온도가 높아질수록 반탄의 수득률이 감소함으로 적절한 반탄화 온도가 요구되었다. $250^{\circ}C$에서의 반탄화로는 헤미셀룰로오스의 분해가 상당히 진행되고 $300^{\circ}C$에서는 셀룰로오스의 분해까지도 거의 진행됨을 OPF의 열분해 거동으로부터 알 수 있었다. 또한, 반탄화된 OPF는 바이오매스의 grindability를 향상시킴으로 분쇄에 소모되는 에너지를 감소시킴을 예측할 수 있었다.

파쇄 메카니즘과 파쇄회로에 따른 입도분포 (Particle-Size Distribution Dependent upon Crushing Mechanism and Crushing Circuit)

  • 최도영;김완태;김상배
    • 한국광물학회지
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    • 제23권4호
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    • pp.297-303
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    • 2010
  • 본 연구에서는 파쇄 메커니즘이 상이한 파쇄기(함마 크럿셔와 롤 크럿셔)와 파쇄회로(개회로 및 폐회로)를 사용하여 각각의 파쇄기 종류에 따른 백운석 파쇄산물의 입도분포와 파쇄특성에 대해 알아보았다. 함마 크럿셔로 파쇄한 경우, 100 mesh 이하의 미분이 약 34 wt.%로 롤 크럿셔로 파쇄한 경우보다 약 3 배 이상 높았다. 또한 14~25 mesh 산물은 롤 크럿셔로 파쇄할 경우, 함마 크럿셔로 파쇄한 경우에 비하여 약 20 wt.% 이상 많이 생성되었다. 35 mesh 이하의 산물은 함마 크럿셔로 파쇄 시 전체의 약 80 wt.% 정도였다. 두 파쇄기 모두 개회로에 비해 폐회로 파쇄 시 미분의 발생률이 감소하였다. 광석에 따른 적절한 파쇄기 및 파쇄회로의 선택에 따라 목적하는 입도의 산물을 효율적으로 얻을 수 있다.

광범위 외측 도달법을 이용한 종골 골절의 경피적 및 최소 내고정술 (Combined Percutaneous and Minimal on Internal Fixation of Calcaneal Fractures Using Extensile Lateral Approach)

  • 유선오;김주성;김종진
    • 대한족부족관절학회지
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    • 제6권2호
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    • pp.201-207
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    • 2002
  • Purpose: To present the clinical analysis of the results obtained in 38 cases of displaced intraarticular calcaneal fractures undergone combined percutaneous axial pin fixation of calcaneal body and minimal internal fixation using extensile lateral approach. Materials and Methods: From March 2000 to February 2002, thirty-eight displaced intraarticular fractures of the calcaneus in 35 patients were fixed with 3.5mm cannulated screws and percutaneous 2.5mm K-wires. The extensile lateral approach was used in all cases. The average follow-up period was 16 months. Clinical evaluation was assessed according to the Ankle-Hind Foot Scale of American Orthopedic Foot and Ankle Society. Results: The clinical results were graded as excellent in 8 cases(21%), good in 22 cases(58%), fair in 6 cases(16%), and poor in 2 cases(5%). Two cases of poor result were type IV of Sanders classification. The postoperative reduction status of the articular surface was analyzed by computed tomography in all cases and was found to be less 2mm of step off in 30 cases and between 2 and 4mm in 8 cases. Unsatisfactory results were correlated with severity of articular comminution and failure to obtain accurate reduction of the articular surface. Using early functional postoperative care, all fractures healed without secondary displacement except 1 case on an average of ten weeks. Two cases had superficial necrosis of the wound margins, however, secondary wound healing was uneventful and skin grafting was not needed. Conclusion: Combined minimal internal fixation and percutaneous pin fixation using extensile lateral approach is useful operative method of intraarticular calcaneal fractures because providing enough stability to permit functional aftercare and allowing excellent anatomical reduction. In addition, this method diminishes the risk of lateral soft tissue problems.

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