• 제목/요약/키워드: Radial Head

검색결과 163건 처리시간 0.026초

도정수율과 성능향상을 위한 연구(I) -벼의 도정성능에 영향을 주는 작동요인- (Study on the Improvement of Milling Recovery and Performance(I) -Operational Factors Affecting Rice Milling Performance-)

  • 정창주;류관희;박예린;이성범
    • Journal of Biosystems Engineering
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    • 제5권2호
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    • pp.1-14
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    • 1980
  • This study was carried out to investigate the effects of the counter-pressure setting and the roller speed of a rice whitening machine on the head rice recovery. milling capacity and milling efficiency, and also to find out the optimum operational conditions of the machine. The radial pressure inside the whitening chamber and the outlet axial pressure were measured to study their relationships with the head rice recovery, milling capacity and milling efficiency. The results of the study are summarized as follows. (1) The most important factor in rice whitening was the counter-pressure setting. It significantly affected the head rice recovery. (2) The roller speed significant affected the milling capacity and milling efficiency , but it did not affected the head rice recovery. (3) Both the radial pressure and the outlet axial pressure were affected by the counter-pressure setting but not by the roller speed. Both of them increased almost linearly with the counter-pressure setting. There was a significant correlation between the radial pressure and the outlet axial pressure. (4) The flow rate through the whitening chamber when the feed gate was fully opened increased with the roller speed, but it was not affected by the counter-pressure setting. (5) The head rice recovery decreased as the counter-pressure setting increased , but it was not affected by the roller speed. The reason could be explained by the fact that the radical pressure increased only with the counter-pressure setting. (6) The milling capacity increased with the counter-pressure setting and linearly with the roller speed. The milling efficiency generally increased with both the counter-pressure setting and the roller speed. However, the effect of roller speed was negligible at the higher counter-pressure setting. The temperature rise inside the whitening chamber was moderate with the mean of 11.3℃ (range 5.6-18.3℃) even though it increased slightly with the roller speed. Considering the head rice recovery and milling efficiency, the optimum operational conditions of the machine appeared to be the counter-pressure setting of 67g/㎠ and the roller speed of 1,050rpm. Neglecting the small difference in the head rice recovery , the greater milling capacity could be obtained at the counter-pressure setting of 85g/㎠ with the roller speed of 850-1050rpm.

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Anterior Dislocation of the Radial Head Combined with Plastic Deformity of the Ulnar Shaft in an Adult: A Case Report

  • Moon, Sang Won;Kim, Youngbok;Kim, Young-Chang;Kim, Ji-Wan;Yoon, Taiyeon;Kim, Seung-Chul
    • Clinics in Shoulder and Elbow
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    • 제21권1호
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    • pp.42-47
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    • 2018
  • A 25-year-old woman presented to the emergency room with a painful and swollen right forearm. She had just sustained an injury from an accident during which her arm was tightly wound by a rope as she was lowering a net from a fishing boat. Before being released, her arm was rigidly trapped in the rope for approximately ten minutes. Radiographs revealed anterior dislocation of the radial head that was accompanied by plastic deformation of the proximal ulna, manifested as a reversal of the proximal dorsal angulation of the ulna (PUDA); suggested a Monteggia equivalent fracture. With the patient under general anesthesia, we reduced the radial head by posterior compression at $90^{\circ}$ of elbow flexion and at neutral rotation of the forearm. However, the reduction was easily lost and the elbow re-dislocated with even slight supination or extension of the arm. After the osteotomy of the ulnar deformity to restore the PUDA to normal, the reduction remained stable even with manipulation of the arm. We found that the patient could exercise a full range of motion without pain at the 3-month follow-up, and neither residual instability nor degenerative changes were observed at the final 3-year follow-up.

비접촉식 웨이퍼 그리퍼용 공압 파지식 헤드 설계 (Design of the Air Pressure Pick-up Head for Non-Contact Wafer Gripper)

  • 김준현
    • 한국생산제조학회지
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    • 제21권3호
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    • pp.401-407
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    • 2012
  • The recent manufacturing process in the thin wafers and flat panel necessitate new approaches to reduce handling fragile and surface-sensitive damage of components. This paper presents a new pneumatic levitation for non-contact handling of parts and substrates. This levitation can achieve non-contact handling by blowing air into an air pressure pick-up head with radial passages to generate a negative pressure region. Negative pressure is caused by the radial air flow by nozzle throat and through holes connecting to the bottom region. The numerical analysis deals with the levitational motion with different design factors. The dynamic motion is examined in terms of force balance(dynamic equilibrium) occurring to the flow field between two objects. The stable equilibrium position and the safe separation distance are determined by analyzing the local pressure distribution in the fluid motion. They make considerable design factors consisting the air pressure pick-up head. As a result, in case that the safe separation distance is beyond 0.7mm, the proposed pick-up head can levitate stably at the equilibrium position. Furthermore, it can provide little effect of torque, and obtain more wide picking region according to the head size.

Type IV Monteggia-equivalent fracture in an adult: a case report

  • Yousef Fallah;Behnam Baghianimoghadam;Salar Baghbani;Amirhosein Karim
    • Clinics in Shoulder and Elbow
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    • 제26권2호
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    • pp.205-207
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    • 2023
  • A Monteggia fracture is a proximal ulnar fracture with proximal radioulnar ligamentous instability. While there is no precise definition, Monteggia-equivalent fractures are generally considered Monteggia fractures accompanied by radial head fractures. These are rare. In this study, we report a rare variation of a Bado type IV Monteggia-equivalent lesion (fracture of proximal ulnar shaft, proximal radial shaft, and radial head) and its management.

홀 센서의 양극 바이어스 수직모드를 이용한 맥파측정시스템 구현 (Implementation of the Pulse Wave Measurement System Using Bipolar Biased Head on Mode of the Hall Sensor)

  • 진상곤;김명남
    • 센서학회지
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    • 제20권5호
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    • pp.322-328
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    • 2011
  • There are many ways to detect the heart rate non-invasively such as ECG, PPG, strain gauge, and pressure sensor. In this paper, the pulse wave measurement system using bipolar biased head on mode of the Hall sensor is proposed for measuring the radial artery pulse. TMS320F2812 was used to implement the proposed system and a portable wireless network(zig-bee) was used to show the experimental result. It was confirmed from experiment that the performance of the implemented system was more stable and faster than PPG sensor or piezoelectric film pressure sensor.

요골 간부 골절 치료 후 지연 발견된 원위 척골의 전방 탈구 (Delayed Diagnosis of Volar Dislocation of the Distal Ulna after Treatment of the Radial Shaft Fracture)

  • 전숙하;이상림
    • 대한정형외과학회지
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    • 제56권5호
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    • pp.427-432
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    • 2021
  • 원위 요척 관절의 전방 탈구 치료가 지연된 경우에는 수근부 통증과 전완의 회전 운동의 제한이 동반되어 결국 구제술이 필요한 퇴행성 관절염이 발생할 수 있다. 24세 남자가 요골 간부 골절 수술 후 통증과 회전 운동 제한으로 내원하였다. 금속판으로 고정된 요골의 간부에서 7도의 전방 각형성이 관찰되었으며 척골 두가 전방으로 탈구되어 회외전에서 결손부가 요골의 S자 절흔 전방 경계에 걸려 탈구가 지속되는 소견이 관찰되었다. 부정 유합된 요골의 교정의 절골술과 척골 두 골결손 근위부의 골을 원위 결손 부위로 이동시키는 절골술을 시행하여 원위 요척 관절이 전완의 회전에 안정적으로 정복이 유지되도록 하였다. 수술 후 19개월에 전완 회전 운동 범위와 통증이 개선된 것을 확인하였다.

원위 요골 악성 종양의 광범위 절제술 후 혈행성 유리 비골 두 이식을 이용한 수근관절 재건술 (Reconstruction of Wrist Joint Using Vascularized Free Fibular Head Graft After the Wide Tumor Excision of Distal Radius)

  • 송석환;이윤민
    • Archives of Reconstructive Microsurgery
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    • 제20권1호
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    • pp.82-88
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    • 2011
  • Vascularized free fibula head transfer is an established method for reconstruction of long bone defects of the upper limb involving the distal radius or the proximal humerus. For the wrist following tumor resection, in cases of resection of the radial articular surface, three reconstructive options are possible: 1. fibular head transfer to replace the radial joint surface, 2. fixation of the fibula to the scaphoid and lunate, 3. complete wrist fusion. The decision on the type of the operation depends on the amount of the resection and the remained normal anatomical structures, and also the necessity of function of the wrist in the future. The authors believe that the vascularized free fibula head graft is a safe and reliable method for reconstructing the upper limb, especially for patients with a defect of the distal radius, and report the operative methods, donor vascular consideration, complications, and functional result after this operation.

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Silicone radial head prostheses revisited: do they have a role in today's practice? A systematic review of literature on clinical outcomes

  • Erik M van Bussel;Anneluuk L. Lindenhovius;Bertram The;Denise Eygendaal
    • Clinics in Shoulder and Elbow
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    • 제26권3호
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    • pp.312-322
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    • 2023
  • Background: Silicone radial head prostheses (SRHP) are considered obsolete due to reports of frequent failure and destructive silicone-induced synovitis. Considering the good outcomes of modern non-radial silicone joint implants, the extent of scientific evidence for this negative view is unclear. The aim of this research was to systematically analyze the clinical evidence on complications and outcomes of SRHP and how SRHP compare to both non-SRHP and silicone prostheses of other joints. Methods: A systematic literature review was conducted through the Cochrane, PubMed, and Embase databases. Results: Eight cohort studies were included, consisting of 142 patients and follow-up periods ranging from 23 months to 8 years. Average patient satisfaction was 86%, range of 71%-100%, and 58 complications were seen, but no cases of synovitis. These outcomes were in line with non-SRHP. Four case series with 11 cases of synovitis were found, all due to implant fractures years to decades after implantation. Six systematic reviews of currently used non-radial silicone joint implants showed excellent outcomes with low complication rates. Conclusions: Since SRHP have satisfactory clinical results and an acceptable complication rate when selecting a patient group in suitable condition for surgical indications, it is considered that SRHP can still be chosen as a potential surgical treatment method in current clinical practice.