Numerical investigation of composite materials reinforced with carbon nanotubes wav

Regarding thermal, mechanical and electrical properties, substantial prospective advances have been offered by Nanotube-reinforced polymers in comparison with pure polymers. This project studies the extent to which the effective stiffness of these materials can be influenced by the characteristic waviness of nanotubes embedded in polymers. In order to numerically determine how the mechanical properties of composite materials which are reinforced with carbon nanotube, are affected by nanotube waviness, a 3D element model of sinusoidal is applied. According to the obtained results, nanotube waviness causes a decrease in the effective modulus of the composite compared to the straight nanotube reinforcement. The degree to which this decrease happens depends on the ratio of the sinusoidal wavelength to the nanotube diameter. It is indicated from these results that nanotube waviness can be another mechanism which limits the modulus improvement of nanotube-reinforced polymers. Several different meshes have been applied on the model in order to predict its effect on the mechanical properties of composite. The results show that finding a proper mesh has significant role in evaluating the model

Factors and Connected Factors in Tough Graphs with High Isolated Toughness

In this paper, we show that every $1$-tough graph with order and isolated toughness at least $r+1$ has a factor whose degrees are $r$, except for at most one vertex with degree $r+1$. Using this result, we conclude that every $3$-tough graph with order and isolated toughness at least $r+1$ has a connected factor whose degrees lie in the set $\{r,r+1\}$, where $r\ge 3$. Also, we show that this factor can be found $m$-tree-connected, when $G$ is a $(2m+\epsilon)$-tough graph with order and isolated toughness at least $r+1$, where $r\ge (2m-1)(2m/\epsilon+1)$ and $\epsilon > 0$. Next, we prove that every $(m+\epsilon)$-tough graph of order at least $2m$ with high enough isolated toughness admits an $m$-tree-connected factor with maximum degree at most $2m+1$. From this result, we derive that every $(2+\epsilon)$-tough graph of order at least three with high enough isolated toughness has a spanning Eulerian subgraph whose degrees lie in the set $\{2,4\}$. In addition, we provide a family of $5/3$-tough graphs with high enough isolated toughness having no connected even factors with bounded maximum degree

Measurement enhances long-distance Entanglement generation in spin chains with dissipative processes

In this paper, effects of the regular measurements on a noisy channel has been investigated. The strategy introduced by A. Bayat, and Y. Omar [New J. Phys. 17, 103041 (2015)] is followed to suppress dephasing and dissipation effects in a noisy spin channel and generate long distance entanglement by global measurement on the channel. A regular global measurements performed on spin channel weakly coupled to the sender and receiver qubits via $XX$ interaction. This scheme is applied for the dephasing and dissipation in non-zero temperature processes separately and the results show that amounts of achieved entanglement enhanced rather than the no-measurement approach.Comment: 6 pages, 6 figures, Comments welcom