Behavior of polyethylene-based nanocomposites containing multi-layer graphene filler

open4siIn this research, the results regarding the characterization of electrical and mechanical properties of a low-density polyethylene (LDPE) - graphene-like (G) nanocomposite are presented. The processing technique used to fabricate the material was high-energy ball milling. This method was utilized to fabricate samples with a filler loading ranging from 1 wt% up to 7wt%. Low voltage broadband dielectric spectroscopy (BDS), erosion tests and breakdown tests (BD) were the measurements carried out in order to characterize the electrical behavior of the fabricated composites. Then, some of the mechanical properties of the LDPE-G nanocomposites were determined with dynamic mechanical analysis (DMA) and, finally, the crystalline structure of the material was investigated with differential scanning calorimetry (DSC).embargoed_20200114Rosi, G.F.; Frechette, M.; David, E.; Fabiani, D.Rosi, G.F.; Frechette, M.; David, E.; Fabiani, D

Strategies for Controlled Placement of Nanoscale Building Blocks

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others

Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I = 12 mag, and it was covered in great detail with almost 25 000 data points gathered by a network of telescopes. We present the photometric and spectroscopic follow-up covering 500 days of the event evolution. We employed a full Keplerian binary orbit microlensing model combined with the motion of Earth and Gaia around the Sun to reproduce the complex light curve. The photometric data allowed us to solve the microlensing event entirely and to derive the complete and unique set of orbital parameters of the binary lensing system. We also report on the detection of the first-ever microlensing space-parallax between the Earth and Gaia located at L2. The properties of the binary system were derived from microlensing parameters, and we found that the system is composed of two main-sequence stars with masses 0.57 ± 0.05 M⊙ and 0.36 ± 0.03 M⊙ at 780 pc, with an orbital period of 2.88 years and an eccentricity of 0.30. We also predict the astrometric microlensing signal for this binary lens as it will be seen by Gaia as well as the radial velocity curve for the binary system. Events such as Gaia16aye indicate the potential for the microlensing method of probing the mass function of dark objects, including black holes, in directions other than that of the Galactic bulge. This case also emphasises the importance of long-term time-domain coordinated observations that can be made with a network of heterogeneous telescopes