http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Guillermo Rubio-Gómez,Sergio Juárez,David Rodríguez-Rosa,Enrique Bravo,Erika Ottaviano,Antonio Gonzalez-Rodriguez,Fernando J. Castillo-Garcia 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.2
Cable-driven robots are parallel manipulators in which rigid links are replaced by actuated cables. The end-effector is then supported by a set of cables commanded by motors that are usually placed in a fixed frame. By varying the cables length, it is possible to change the end-effector position and/or orientation. Among the advantages presented by cable robots are they light-weight structure, high energy efficiency and their ability to cover large workspaces since cables are easy to wind. When high-speed operation is not required, a safer solution is to design cable-driven suspended robots, where all vertical components of cables tension are against gravity direction. Cable-driven suspended robots present limited workspace due to the elevated torque requirements for the higher part of the workspace. In this paper, the addition of a passive carriage in the top of the frame is proposed, allowing to achieve a much greater feasible workspace than the conventional one, i.e., with the same size as the desired inspection area while maintaining the same motor requirements. In the opposite, this new scheme presents non-desired vibration during the end-effector maneuvers. These vibrations can be removed by means of a more complex control strategy. Kinematics and dynamics models are developed in this paper. An analysis of sensor system is carried out and a control scheme is proposed for controlling the end-effector pose. Simulation and experimental results show that the feasible workspace can be notoriously increased while end-effector pose is controlled. This new architecture of cable-driven robot can be easily applied for automated inspection and monitoring of very large vertical surfaces of civil infrastructures, such as facades or dams.
A novel hybrid carbon material
Nasibulin, Albert G.,Pikhitsa, Peter V.,Jiang, Hua,Brown, David P.,Krasheninnikov, Arkady V.,Anisimov, Anton S.,Queipo, Paula,Moisala, Anna,Gonzalez, David,Lientschnig, Gü,nther,Hassanien, Abdou,S Springer Science and Business Media LLC 2007 Nature nanotechnology Vol.2 No.3
<P>Both fullerenes and single-walled carbon nanotubes (SWNTs) exhibit many advantageous properties. Despite the similarities between these two forms of carbon, there have been very few attempts to physically merge them. We have discovered a novel hybrid material that combines fullerenes and SWNTs into a single structure in which the fullerenes are covalently bonded to the outer surface of the SWNTs. These fullerene-functionalized SWNTs, which we have termed NanoBuds, were selectively synthesized in two different one-step continuous methods, during which fullerenes were formed on iron-catalyst particles together with SWNTs during CO disproportionation. The field-emission characteristics of NanoBuds suggest that they may possess advantageous properties compared with single-walled nanotubes or fullerenes alone, or in their non-bonded configurations.</P>
CVD synthesis and radial deformations of large diameter single-walled CNTs
Paula Queipo,Albert G. Nasibulin,Sergey D. Shandakov,David Gonzalez,Hua Jiang,Esko I. Kauppinen 한국물리학회 2009 Current Applied Physics Vol.9 No.3
Single-walled carbon nanotubes (CNTs) were synthesized by a chemical vapor deposition (CVD) method on transmission electron microscopy (TEM) silica coated nickel grids using carbon monoxide as carbon source and iron nanoparticles as catalyst. The produced CNTs were as large as 11 nm in diameter. Investigations on the CNT deformations based on high-resolution TEM images showed that the deformation of CNTs due to their interaction with the substrate occurs at diameters larger than 2.7 nm. Small deformation of free standing tubes was found to occur at diameters above approximately 4.5 nm. Single-walled carbon nanotubes (CNTs) were synthesized by a chemical vapor deposition (CVD) method on transmission electron microscopy (TEM) silica coated nickel grids using carbon monoxide as carbon source and iron nanoparticles as catalyst. The produced CNTs were as large as 11 nm in diameter. Investigations on the CNT deformations based on high-resolution TEM images showed that the deformation of CNTs due to their interaction with the substrate occurs at diameters larger than 2.7 nm. Small deformation of free standing tubes was found to occur at diameters above approximately 4.5 nm.