To compare the velocity characteristics of wheelchair propulsion with and without the use of a tennis racquet, eight male wheelchair tennis players performed a series of 20m sprints from a stationary start. The maximum velocities reached on average 4.39 ± 0.74 m/s; however, they were reduced by 0.18 ± 0.06 m/s during the racquet condition. Furthermore, when wheeling under the racquet condition,...

In this article, we develop a set of partial differential equations describing the flow of a dusty fluid in variable porosity media. The developed equations take into account the effect of the porous microstructure on the flowing phases. We presented and overview of the equations governing the flow of a dusty gas in various type media, including that in naturally occurring porous media. Numeric...

PAF-16 which is based on tetrahedral units (TCPSi) and triangular building units, shows both high thermal stability and high chemical stability. The surface area of PAF-16 can be tuned by changing the reaction temperature and ratio of monomer and catalyst. PAF-16 also shows considerable adsorption capacity of CO(2).

The whole class of minimally coupled and massive scalar fields which may be responsible for flattening of galactic rotation curves is found. An interesting relation with a class of scalar-tensor theories able to isotropise anisotropic models of Universe is shown. The resulting metric is found and its stability and scalar field properties are tested with respect to the presence of a second scala...

As an important two-dimensional material which shows exceptional mechanical and chemical stability, superior electronic properties, along with broad applications, the hexagonal-BN (h-BN) has drawn great attention recently. Here we report a systematic study on the structural stability, electronic and magnetic properties of various h-BN edges, including both bare and hydrogen-terminated ones. It ...

We introduce a model for the classical synchronised multiple access system with a single transmission channel and a randomised transmission protocol (ALOHA). We assume in addition that there is an energy harvesting mechanism, and any message transmission requires a unit of energy. Units of energy arrive randomly and independently of anything else. We analyse stability and instability conditions...

The application of convolution potential voh.ammetry to questions of metal complexation is described. Theoretical relations are derived to show that the stability constants may be directly related to the shift in the peak potential of the semiderivative wave, provided the complexes are labile. Equations are also given for inert and quasilabile complexes. Stability constants for the PbCI, and Cd...

Contraction theory provides an elegant way of analyzing the behaviors of systems subject to external inputs. Under sometimes easy to check hypotheses, systems can be shown to have the incremental stability property that all trajectories converge to a unique solution. This property is especially interesting when forcing functions are periodic (a globally attracting limit cycle results), as well ...

Time integration schemes with a fixed time step, much smaller than the dominant slow time scales of the dynamics of the system, arise in the context of stiff ordinary differential equations or in multiscale computations, where a microscopic time stepper is used to compute macroscopic behaviour. We discuss a method to accelerate such a time integrator by using extrapolation. This method extends ...

This paper presents an extension of the Motivated Learning model that includes environment masking, and opportunistic behavior of the motivated learning agent. Environment masking improves an agent’s ability to learn by helping to filter out distractions, and the addition of a more complex environment increases the simulation’s realism. If conditions call for it opportunistic behavior allows an...