نتایج جستجو برای: nano ptfe

تعداد نتایج: 52545  

Journal: :Brazilian dental journal 2010
Fabiana Gouveia Straioto Antonio Pedro Ricomini Filho Alfredo Júlio Fernandes Neto Altair Antoninha Del Bel Cury

The addition of different polymers, such as polytetrafluorethylene (PTFE), to denture base resins could be an option to modify acrylic resin mechanical properties. This study evaluated the surface hardness, impact and flexural strength, flexural modulus and peak load of 2 acrylic resins, one subjected to a long and another subjected to a short polymerization cycle, which were prepared with or w...

2004
L. Y. L. Wu

PTFE-based coatings have been widely used, for example, on aluminium moulds for moulding of polyolefin packaging materials for its non-stick property. However, these coatings do not meet the users’ scratch resistance and durability requirements. This paper describes a preliminary study on the synthesis and characterization of a PTFE/sol-gel composite coating material which combines the required...

2017
Anton Panda Kostiantyn Dyadyura Jan Valíček Marta Harničárová Jozef Zajac Vladimír Modrák Iveta Pandová Peter Vrábel Ema Nováková-Marcinčínová Zdeněk Pavelek

The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE) filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The ...

2011
A. Tamayol

Effects of mechanical compression and PTFE content on the through-plane gas permeability of gas diffusion layers (GDLs) of PEM fuel cells are investigated both experimentally and theoretically. A new test bed is designed and built which allows pressure drop and air flow rate measurement for various fibrous samples. The measured values are used to calculate the through-plane permeability. Variou...

2007
David L. Burris Scott S. Perry Gregory Sawyer

Under macroscopic pin-on-disk testing the sliding friction coefficient of Polytetrafluoroethylene (PTFE) was investigated over a temperature range of approximately 200–400 K. This study examines the nature of the temperature dependence by testing PTFE pins at varying temperature and humidity on a linear reciprocating pin-on-disk tribometer. The friction coefficient increased monotonically with ...

2018
Simon Vergnaud Valéry-Pierre Riche Philippe Tessier Nicolas Mauduit Adrien Kaladji Yann Gouëffic

OBJECTIVES To evaluate the budget impact of progressive replacement of standard polytetrafluoroethylene (PTFE) grafts by heparin-bound PTFE (Propaten) for below-the-knee (BTK) bypass in patients with critical limb ischaemia (CLI). DESIGN From a review of the scientific literature, we calculated a theoretical BTK primary patency for Propaten grafts. Using the French hospital expenditure databa...

Journal: :Circulation 2003
Goran Stankovic Antonio Colombo Patrizia Presbitero Frank van den Branden Luigi Inglese Carmelo Cernigliaro Luigi Niccoli Antonio L Bartorelli Paolo Rubartelli Nicholaus Reifart Guy R Heyndrickx Kari Saunamäki Marie Claude Morice Fabio A Sgura Carlo Di Mario

BACKGROUND Treatment of lesions located in saphenous vein grafts (SVGs) is associated with increased procedural risk and a high rate of restenosis. METHODS AND RESULTS We conducted a randomized, multicenter trial to evaluate the usefulness of a polytetrafluoroethylene (PTFE)-covered stent compared with a bare stainless steel (SS) stent for prevention of restenosis and major adverse cardiac ev...

2015
Seon-Hee Heo Yang-Jin Park Shin-Young Woo Dong-Ik Kim Young-Wook Kim

PURPOSE To analyze the long-term results of above-the-knee femoro-popliteal bypass (ATKFPB) with vein grafts compared with polytetrafluoroethylene (PTFE) grafts. METHODS A database of patients with chronic atherosclerotic occlusive disease who underwent ATKFPB was retrospectively reviewed. Characteristics of patient and arterial lesion, and follow-up results were compared between vein grafts ...

2013
QINGHUA WU JIANWEI JIANG YUJIE HE TIANPENG JIANG SHI ZHOU

The aim of this study was to evaluate the feasibility of transjugular intrahepatic portosystemic shunts using FLUENCY expanded polytetraf luoroethylene (PTFE)-covered stents and the effect on the patency rate. A total of 114 cirrhotic patients who were treated by transjugular intrahepatic portosystemic stent shunt (TIPS) placement using a FLUENCY expanded, PTFE-covered stent were enrolled in th...

2006
David L. Burris W. Gregory Sawyer

Past studies with PTFE nanocomposites showed up to 600× improvements in wear resistance over unfilled PTFE with the addition of Al2O3 nanoparticles. Irregular shaped nanoparticles are used in this study to increase the mechanical entanglement of PTFE fibrils with the filler. The tribological properties of 1, 2, 5 and 10 wt.% filled samples are evaluated under a normal pressure and sliding speed...

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