Engineering topics

Makarov, Vladimir

Publications and source records attributed to Makarov, Vladimir.

7 records

NASA NTRS2018

Antibacterial Activity of Silver-Graphene Quantum Dots Nanocomposites Against Gram-Positive and Gram-Negative Bacteria

The invention provides a composite of silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) using pulsed laser synthesis. The nanocomposites were functionalized with polyethylene glycol (PEG). A concentration of 150 .mu.g/mL of Ag-GQDs, a non-toxic level for human cells, exhibits strong antibacterial activity against both Gram-Positive and Gram-Negative Bacteria.

Habiba, Khaled↗

NASA NTRS2017

Diamond-Like Carbon Nanorods and Fabrication Thereof

Novel sp. (sup 3) rich diamond-like carbon (DLC) nanorod films were fabricated by hot filament chemical vapor deposition technique. The results are indicative of a bottom-up self-assembly synthesis process, which results in a hierarchical structure that consists of microscale papillae comprising numerous nanorods. The papillae have diameters ranging from 2 to 4 microns and the nanorods have diameters in the 35-45 nanometer range. A growth mechanism based on the vapor liquid-solid mechanism is proposed that accounts for the morphological aspects in the micro- and nano-scales.

Varshney, Deepak↗

DOE OSTI2016

Superemission of Cr nanolayers

Highlights: • Development of novel nanodevices for superemission generation. • Development of nanolasers based on metal nanofilms. • Development of theory of nanolasers based on metal nanofilms. - Abstract: We continue our studies of metal nanolayers started earlier [1]. Presently, we investigate absorption, emission and superemission in Cr nanolayers. We provide experimental estimates of the energy density and power density of superemission of Cr nanolayers, along with estimates of the diffraction-limited light divergence. We report that the divergence of the superemission along the direction normal to the nanolayer corresponds to that of a point source, with the divergence angle of ca. 0.2 rad. Additionally, we report surprising long-range transfer of the excitation energy in Cr metal films, at macroscopic distances of 1 cm.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Synthesis micro-scale boron nitride nanotubes at low substrate temperature

High temperature synthesis methods produce defects in 1D nanomaterials, which ultimately limit their applications. We report here the synthesis of micro-scale boron nitride nanotubes (BNNT) at low substrate temperature (300 {sup o}C) using a pulsed CO{sub 2} laser deposition technique in the presence of catalyst. The electron microscopic analyses have shown the nanotubes distributed randomly on the surface of the substrate. The average diameter (∼0.25 μm) of a nanotube, which is the highest reported value to date, is estimated by SEM data and confirmed by TEM measurements. These nanotubes are promising for high response deep-UV photo-luminescent devices. A detailed synthesis mechanism is presented and correlated with the experimental results.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

NASA NTRS2013

Low-Energy, Hydrogen-Free Method of Diamond Synthesis

Diamond thin films were deposited on copper substrate by the Vapor Solid (VS) deposition method using a mixture of fullerene C(sub 60) and graphite as the source material. The deposition took place only when the substrate was kept in a narrow temperature range of approximately 550-650 C. Temperatures below and above this range results in the deposition of fullerenes and other carbon compounds, respectively.

Varshney, Deepak↗

NASA NTRS2013

Diamond Nucleation Using Polyethene

The invention presents a simple, non-destructive and non-abrasive method of diamond nucleation using polyethene. It particularly describes the nucleation of diamond on an electrically viable substrate surface using polyethene via chemical vapor deposition (CVD) technique in a gaseous environment.

Morell, Gerardo↗

DOE OSTI2013

Diamond nucleation using polyethene

36 MATERIALS SCIENCE↗