Waves produced by a source on the moving and expanding circular frame

Author(s):  
V.V. Borisov
Keyword(s):  
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Caroline B. Hing ◽  
Elizabeth Tutton ◽  
Toby O. Smith ◽  
Molly Glaze ◽  
Jamie R. Stokes ◽  
...  

Abstract Background Segmental tibial fractures are fractures in two or more areas of the tibial diaphysis resulting in a separate intercalary segment of the bone. Surgical fixation is recommended for patients with segmental tibial fractures as non-operative treatment outcomes are poor. The most common surgical interventions are intramedullary nailing (IMN) and circular frame external fixation (CFEF), but evidence about which is better is of poor quality. An adequately powered randomised controlled trial (RCT) to determine optimum treatment is required. STIFF-F aimed to assess the feasibility of a multicentre RCT comparing IMN with CFEF for segmental tibial fracture. Methods STIFF-F was a mixed-methods feasibility study comprising a pilot RCT conducted at six UK Major Trauma Centres, qualitative interviews drawing on Phenomenology and an online survey of rehabilitation. The primary outcome was recruitment rate. Patients, 16 years and over, with a segmental tibial fracture (open or closed) deemed suitable for IMN or CFEF were eligible to participate. Randomisation was stratified by site using random permuted blocks of varying sizes. Participant or assessor blinding was not possible. Interviews were undertaken with patients about their experience of injury, treatment, recovery and participation. Staff were interviewed to identify contextual factors affecting trial processes, their experience of recruitment and the treatment pathway. An online survey was developed to understand the rehabilitation context of the treatments. Results Eleven patients were screened and three recruited to the pilot RCT. Nineteen staff and four patients participated in interviews, and 11 physiotherapists responded to the survey. This study found the following: (i) segmental tibial fractures were rarer than anticipated, (ii) the complexity of the injury, study setup times and surgeon treatment preferences impeded recruitment, (iii) recovery from a segmental tibial fracture is challenging, and rehabilitation protocols are inconsistent and (iv) despite the difficulty recruiting, staff valued this research question and strived to find a way forward. Conclusion The proposed multicentre RCT comparing IMN with CFEF is not feasible. This study highlighted the difficulty of recruiting patients to an RCT of a complex rare injury over a short time period. Trial registration The study was registered with the International Standard Randomised Controlled Trials Number Registry: ISRCTN11229660


2010 ◽  
Vol 66 (3) ◽  
pp. 420-427 ◽  
Author(s):  
Alexander Y. Tuan ◽  
Christopher Y. Tuan ◽  
Q.S. Li

2018 ◽  
Vol 28 (2) ◽  
pp. 249-269 ◽  
Author(s):  
Enock Bonyi ◽  
Christopher S Meyer ◽  
Bridgit Kioko ◽  
Oreoluwa Adesina ◽  
Carisse Lansiquot ◽  
...  

A methodology is developed to visually analyze and quantify macroscale and mesoscale impact damage on a single layer of S-2 glass/SC15 toughened epoxy plain weave composite. Specimens were clamped in a 203 mm diameter circular frame and impacted by a 5.5 mm (0.22 caliber) right circular cylindrical steel projectile at impact velocities ranging from 104 to 472 m/s. High-resolution images were obtained at the point of impact and up to the edge of the circular frame using an 80 MP camera. Three types of mesoscale damage were identified: (i) transverse tow cracks, (ii) tow–tow delamination, and (iii) 45° matrix cracks. A MATLAB program was developed to translate the image data into a digital damage map whereby the output of color intensity correlated with the quantity and type of material damage. Digital maps generated for select specimens revealed that characteristic damage patterns arise for woven fabric composites including a diamond pattern in matrix cracking and a cross pattern in tow–tow delamination. The greatest extent of matrix cracks and tow–tow delamination over any specimen was observed for the projectile impact with initial velocity of 174 m/s, which is very close to the calculated ballistic limit velocity of 175 m/s.


2006 ◽  
Vol 45 (5) ◽  
pp. 295-299 ◽  
Author(s):  
Konstantinos N. Malizos ◽  
Konstantinos Bargiotas ◽  
Loucia Papatheodorou ◽  
Apostolos Dimitroulias ◽  
Theofilos Karachalios

SLEEP ◽  
1994 ◽  
Vol 17 (3) ◽  
pp. 208-219 ◽  
Author(s):  
Ennio A. Vivaldi ◽  
Ursula Wyneken ◽  
Manuel Roncagliolo ◽  
Adrián Ocampo ◽  
Ana M. Zapata
Keyword(s):  

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