1,036 research outputs found
Carbon nanotube and graphene fiber artificial muscles
Actuator materials capable of producing a rotational or tensile motion are rare and, yet, rotary systems are extensively utilized in mechanical systems like electric motors, pumps, turbines and compressors. Rotating elements of such machines can be rather complex and, therefore, difficult to miniaturize. Rotating action at the microscale, or even nanoscale, would benefit from the direct generation of torsion from an actuator material. Herein we discuss the advantages of using carbon nanotube (CNT) yarns and/or graphene (G) fibers as novel artificial muscles that have the ability to be driven by the electrochemical charging of helically wound multiwall carbon nanotubes or graphene fibers as well as elements in the ambient environment such as moisture to generate such rotational action. The torsional strain, torque, speed and lifetime have been evaluated under various electrochemical conditions to provide insight into the actuation mechanism and performance. Here the most recent advances in artificial muscles based on sheath-run artificial muscles (SRAMs) are reviewed. Finally, the rotating motion of the CNT yarn actuator and the humidity-responsive twisted graphene fibers have been coupled to a mixer for use in a prototype microfluidic system, moisture management and a humidity switch respectively
Ions in solution: Density Corrected Density Functional Theory (DC-DFT)
Standard density functional approximations often give questionable results
for odd-electron radical complexes, with the error typically attributed to
self-interaction. In density corrected density functional theory (DC-DFT),
certain classes of density functional theory calculations are significantly
improved by using densities more accurate than the self-consistent densities.
We discuss how to identify such cases, and how DC-DFT applies more generally.
To illustrate, we calculate potential energy surfaces of HOCl and
HOHO complexes using various common approximate functionals, with
and without this density correction. Commonly used approximations yield wrongly
shaped surfaces and/or incorrect minima when calculated self consistently,
while yielding almost identical shapes and minima when density corrected. This
improvement is retained even in the presence of implicit solvent
Characterization of organic matter in the Torridonian using Raman spectroscopy
We gratefully acknowledge two anonymous reviewers for their constructive comments on an earlier version of this manuscript. Earth System Evolution and Early Life: a Celebration of the Work of Martin Brasier. ed. / A. T. Brasier; D. McIlroy; N. McLoughlin. 978-1-78620-279-6Peer reviewedPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprin
Opportunities for group self-management programs to reduce the burden of arthritis in Australia
Reducing the SPS Machine Impedance
The SPS as LHC Injector project has been working for some time to prepare the SPS for its role as final injector for the LHC. This included major work related to injection, acceleration, extraction and beam instrumentation for the LHC beams [1]. Measurements carried out with the high brightness LHC beam showed that a major improvement of the machine impedance would also be necessary [2]. In addition to removing all lepton related components (once LEP operation ended in 2000), the decision was made to shield the vacuum system pumping port cavities. These accidental cavities had been identified as having characteristic frequencies in the 1-1.5GHz range. Since the SPS vacuum system contains roughly 1000 of these cavities, they constitute a major fraction of the machine impedance. As removal of the ports and associated bellows is not possible, transition shields (PPS) had to be designed to insert within the pumping port cavities
Economic evaluation strategies in telehealth: obtaining a more holistic valuation of telehealth interventions
Telehealth is an emerging area of medical research. Its translation from conception, to research and into practice requires tailored research and economic evaluation methods. Due to their nature telehealth interventions exhibit a number of extra-clinical benefits that are relevant when valuing their costs and outcomes. By incorporating methods to measure societal values such as patient preference and willingness-to-pay, a more holistic value can be placed on the extra-clinical outcomes associated with telehealth and evaluations can represent new interventions more effectively. Cost-benefit analysis is a method by which relevant costs and outcomes in telehealth can be succinctly valued and compared. When health economic methods are conducted using holistic approaches such as cost-benefit analysis they can facilitate the translation of telehealth research into policy and practice
- âŠ