Search results for " Coating."
showing 8 items of 2558 documents
2-Methylresorcinarene: a very high packing coefficient in a mono-anion based dimeric capsule and the X-ray crystal structure of the tetra-anion
2016
Mono- and tetra-deprotonated 2-methylresorcinarene anions (1 and 2) as their trans-1,4-diammoniumcyclohexane (TDAC)2+ inclusion complexes are reported. The mono-anion forms a fully closed dimeric capsule [1·H2O·MeOH]22− with a cavity volume of 165 Å3 and (TDAC)2+ as the guest with an extremely high packing coefficient, PC = 84.2%, while the tetra-anion forms a close-packed structure with two structurally isomeric tetra-anions 2a and 2b with a 50 : 50 ratio in the crystal lattice. peerReviewed
Laser fluence, repetition rate and pulse duration effects on paint ablation
2006
Abstract The efficiency (mm3/(J pulse)) of laser ablation of paint was investigated with nanosecond pulsed Nd:YAG lasers (λ = 532 nm) as a function of the following laser beam parameters: pulse repetition rate (1–10,000 Hz), laser fluence (0.1–5 J/cm2) and pulse duration (5 ns and 100 ns). In our study, the best ablation efficiency (η ≅ 0.3 mm3/J) was obtained with the highest repetition rate (10 kHz) at the fluence F = 1.5 J/cm2. This ablation efficiency can be associated with heat accumulation at high repetition rate, which leads to the ablation threshold decrease. Despite the low thermal diffusivity and the low optical absorption of the paint (thermal confinement regime), the ablation th…
Atomic layer deposition of localised boron- and hydrogen-doped aluminium oxide using trimethyl borate as a dopant precursor
2020
Atomic layer deposition (ALD) of boron-containing films has been mainly studied for use in 2D materials and for B-doping of Si. Furthermore, lithium-containing borates show great promise as solid electrolyte coatings for enhanced energy storage. In this work, we examine trimethyl borate (TMB) and triethyl borate (TEB) in combination with O2 plasma as precursors for ALD of B-containing films, targeting the growth of B2O3. It is found that films grown from TEB contain no boron. Further work with TMB as a boron-containing precursor showed promising initial growth on a SiO2 or Al2O3 surface, but a rapid decrease of the growth rate during subsequent ALD cycles indicating surface inhibition durin…
Effect of the extensional flow on the properties of oriented nanocomposite films for twist wrapping
2011
In this study, we examined the mechanical behavior of nanocomposite films based on polyethylene (PE) and pristine PE films. The films were prepared by film blowing and were then cold-drawn at low temperature. The experimental results show that cold drawing significantly enhanced the orientation; with increasing draw ratio (DR), the elastic modulus and tensile strength of the PE films strongly increased, particularly in the presence of the organoclay. To obtain polymeric films suitable for twist wrapping, the films must be sufficiently stiff so that no shrinkage or elastic recovery occur during or after twisting. The elongation at break and the yield strain sharply decreased with orientation…
Conformational Dynamics of the Dengue Virus Protease Revealed by Fluorescence Correlation and Single-Molecule FRET Studies.
2021
The dengue virus protease (DENV-PR) represents an attractive target for counteracting DENV infections. It is generally assumed that DENV-PR can exist in an open and a closed conformation and that active site directed ligands stabilize the closed state. While crystal structures of both the open and the closed conformation were successfully resolved, information about the prevalence of these conformations in solution remains elusive. Herein, we address the question of whether there is an equilibrium between different conformations in solution which can be influenced by addition of a competitive inhibitor. To this end, DENV-PR was statistically labeled by two dye molecules constituting a FRET …
The Effect of Electrolytic Solution Composition on the Structure, Corrosion, and Wear Resistance of PEO Coatings on AZ31 Magnesium Alloy
2020
Plasma electrolytic oxidation coatings were prepared in aluminate, phosphate, and silicate-based electrolytic solutions using a soft-sparking regime in a multi-frequency stepped process to compare the structure, corrosion, and wear characteristics of the obtained coatings on AZ31 magnesium alloy. The XRD results indicated that all coatings consist of MgO and MgF2, while specific products such as Mg2SiO4, MgSiO3, Mg2P2O7, and MgAl2O4 were also present in specimens based on the selected solution. Surface morphology of the obtained coatings was strongly affected by the electrolyte composition. Aluminate-containing coating showed volcano-like, nodular particles and craters distributed over the …
Synergistic effect of W incorporation and pulsed current mode on wear and tribocorrosion resistance of coatings grown by plasma electrolytic oxidatio…
2019
Ceramic coatings were grown by plasma electrolytic oxidation on 7075 Al alloy using unipolar and bipolar pulsed current waveforms with 20 and 40% cathodic duty cycles, from a silicate-based bath without and with the addition of Na2WO4. Pancake-like morphology was dominant on the coatings grown by unipolar waveform, while the bipolar waveforms promoted volcano-like morphology, increased the roughness of the coating surface and the formation of more compact layers. The coatings produced using the bipolar waveforms provided higher resistances toward both tribocorrosion and dry sliding conditions, while further improvement was achieved by the presence of tungsten. The coatings produced in tungs…
Tribological and Mechanical Properties of the Nanostructured Superlattice Coatings with Respect to Surface Texture
2022
This research is funded by the Latvian Council of Science, project “Carbon-rich self-healing multifunctional nanostructured smart coatings (NSC) for high-tech applications using high-power confined plasma technology for their deposition”, project No. 2019/1-0385.