44 research outputs found
Non-minimally Coupled Quintom Model Inspired by String Theory
In this paper we consider a quintom model of dark energy with a single scalar
field given by a Lagrangian which inspired by tachyonic Lagrangian in
string theory. We consider non-minimal coupling of tachyon field to the scalar
curvature, then we obtain the equation of state (EoS), and the condition
required for the model parameters when crosses over -1.Comment: 8 pages, 2 figure
Three-dimensionally printed polycaprolactone/multicomponent bioactive glass scaffolds for potential application in bone tissue engineering
Over the last years, three-dimensional (3D) printing has been successfully applied to produce suitable substitutes for treating bone defects. In this work, 3D printed composite scaffolds of polycaprolactone (PCL) and strontium (Sr)- and cobalt (Co)-doped multi-component melt-derived bioactive glasses (BGs) were prepared for bone tissue engineering strategies. For this purpose, 30 of as-prepared BG particles (size <38 μm) were incorporated into PCL, and then the obtained composite mix was introduced into a 3D printing machine to fabricate layer-by-layer porous structures with the size of 12 � 12 � 2 mm3. The scaffolds were fully characterized through a series of physico-chemical and biological assays. Adding the BGs to PCL led to an improvement in the compressive strength of the fabricated scaffolds and increased their hydrophilicity. Furthermore, the PCL/BG scaffolds showed apatite-forming ability (i.e., bioactivity behavior) after being immersed in simulated body fluid (SBF). The in vitro cellular examinations revealed the cytocompatibility of the scaffolds and confirmed them as suitable substrates for the adhesion and proliferation of MG-63 osteosarcoma cells. In conclusion, 3D printed composite scaffolds made of PCL and Sr- and Co-doped BGs might be potentially-beneficial bone replacements, and the achieved results motivate further research on these materials. © 2020 Amirhosein Fathi et al., published by De Gruyter 2020
Gravity and Electromagnetism with -type Coupling and Magnetic Monopole Solutions
We investigate -type coupling of electromagnetic fields to
gravity. After we derive field equations by a first order variational principle
from the Lagrangian formulation of the non-minimally coupled theory, we look
for static, spherically symmetric, magnetic monopole solutions. We point out
that the solutions can provide possible geometries which may explain the
flatness of the observed rotation curves of galaxies.Comment: 10 page
Phantom Behavior Bounce with Tachyon and Non-minimal Derivative Coupling
The bouncing cosmology provides a successful solution of the cosmological
singularity problem. In this paper, we study the bouncing behavior of a single
scalar field model with tachyon field non-minimally coupled to itself, its
derivative and to the curvature. By utilizing the numerical calculations we
will show that the bouncing solution can appear in the universe dominated by
such a quintom matter with equation of state crossing the phantom divide line.
We also investigate the classical stability of our model using the phase
velocity of the homogeneous perturbations of the tachyon scalar field.Comment: 15 pages, 8 figures, Accepted for publication in JCAP. arXiv admin
note: substantial text overlap with arXiv:1105.496
Heterogeneous 2.5D integration on through silicon interposer
© 2015 AIP Publishing LLC. Driven by the need to reduce the power consumption of mobile devices, and servers/data centers, and yet continue to deliver improved performance and experience by the end consumer of digital data, the semiconductor industry is looking for new technologies for manufacturing integrated circuits (ICs). In this quest, power consumed in transferring data over copper interconnects is a sizeable portion that needs to be addressed now and continuing over the next few decades. 2.5D Through-Si-Interposer (TSI) is a strong candidate to deliver improved performance while consuming lower power than in previous generations of servers/data centers and mobile devices. These low-power/high-performance advantages are realized through achievement of high interconnect densities on the TSI (higher than ever seen on Printed Circuit Boards (PCBs) or organic substrates), and enabling heterogeneous integration on the TSI platform where individual ICs are assembled at close proximity
Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications
This work was supported by a restricted research grant of Bayer AG