12 research outputs found
Generalized Flows around Neutron Stars
In this chapter, we present a brief and non-exhaustive review of the
developments of theoretical models for accretion flows around neutron stars. A
somewhat chronological summary of crucial observations and modelling of timing
and spectral properties are given in sections 2 and 3. In section 4, we argue
why and how the Two-Component Advective Flow (TCAF) solution can be applied to
the cases of neutron stars when suitable modifications are made for the NSs. We
showcase some of our findings from Monte Carlo and Smoothed Particle
Hydrodynamic simulations which further strengthens the points raised in section
4. In summary, we remark on the possibility of future works using TCAF for both
weakly magnetic and magnetic Neutron Stars.Comment: 15 pages, 7 figures. arXiv admin note: text overlap with
arXiv:1901.0084
Wearable high-performance pressure sensors based on three-dimensional electrospun conductive nanofibers
Polymer-based pressure sensors play a key role in realizing lightweight and inexpensive wearable devices for healthcare and environmental monitoring systems. Here, conductive core/shell polymer nanofibers composed of poly (vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP)/poly(3,4-ethylenedioxythiophene) (PEDOT) are fabricated using three-dimensional (3D) electrospinning and vapor deposition polymerization methods, and the resulting sponge-like 3D membranes are used to create piezoresistive-type pressure sensors. Interestingly, the PEDOT shell consists of well-dispersed spherical bumps, leading to the formation of a hierarchical conductive surface that enhances the sensitivity to external pressure. The sponge-like 3D mats exhibit a much higher pressure sensitivity than the conventional electrospun 2D mats due to their enhanced porosity and pressure-tunable contact area. Furthermore, large-area, wireless, 16 x 10 multiarray pressure sensors for the spatiotemporal mapping of multiple pressure points and wearable bands for monitoring blood pressure have been fabricated from these 3D mats. To the best of our knowledge, this is the first report of the fabrication of electrospun 3D membranes with nanoscopically engineered fibers that can detect changes in external pressure with high sensitivity. The developed method opens a new route to the mass production of polymer-based pressure sensors with high mechanical durability, which creates additional possibilities for the development of human-machine interfaces.11Ysciescopu
Cerium(III) Complex Modified Gold Electrode: An Efficient Electrocatalyst for the Oxygen Evolution Reaction
Exploring efficient
and inexpensive electrocatalysts for the oxidation of water is of
great importance for various electrochemical energy storage and conversion
technologies. In the present study, a new water-soluble [Ce<sup>III</sup>(DMF) (HSO<sub>4</sub>)<sub>3</sub>] complex was synthesized and
characterized by UV–vis, photoluminescence, and high-resolution
X-ray photoelectron spectroscopy techniques. Owing to classic 5d →
4f transitions, an intense photoluminescence in the UV region was
observed from the water-soluble [Ce<sup>III</sup>(DMF) (HSO<sub>4</sub>)<sub>3</sub>] complex. A stacking electrode was designed where self-assembled l-cysteine monolayer modified gold was immobilized with the
synthesized cerium complex and was characterized by scanning electron
microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry.
The resulting electrode, i.e., [Ce<sup>III</sup>(DMF) (HSO<sub>4</sub>)<sub>3</sub>]–l-cysteine-Au stacks shows high electrocatalytic
water oxidation behavior at an overpotential of η ≈ 0.34
V under neutral pH conditions. We also demonstrated a way where the
overpotential is possible to decrease upon irradiation of UV light