Thionation of N-Methyl- and N-Unsubstituted Thiazolidine Enaminones

The potential of the directional non-bonded 1,5-type S···O interactions to initiate an incipient stage of an in situ rearrangement of N-unsubstituted thiazolidine enaminones to the functionalized 1,2-dithioles has been demonstrated. Spectral characteristics, as well as an X-ray structural analysis of the selected rearranged product, indicate that a dynamic interconversion occurs in a solution between the 1,2-dithiole and 3,3aλ⁴,4-trithia-1-azapentalene bicylic form. The lack of the rearrangement in the case of the N-methyl substituted enaminone precursor is attributed to an unfavorable methyl migration in the last reaction step

Zeolite-based photocatalysts immobilized on aluminum support by plasma electrolytic oxidation

The preparation and properties of zeolite-containing oxide coatings obtained by plasma electrolytic oxidation are investigated and discussed. Pure and Ce-exchanged natural (clinoptilolite) and synthetic (13X) zeolites are immobilized on aluminum support from silicate-based electrolyte. Obtained coatings are characterized with respect to their morphology, phase and chemical composition, photocatalytic activity and anti-corrosion properties. It is observed that all mentioned properties of obtained coatings are dependent on processing time and type of immobilized zeolite. Coatings with Ce-exchanged zeolite show higher photocatalytic activity and more effective corrosion protection than those with pure zeolite. The highest photocatalytic activity is observed for coatings processed in pulsed a DC regime for 30 minutes containing Ce-exchanged 13X zeolite, followed by those containing Ce-exchanged clinoptilolite. Pronounced anti-corrosion properties feature almost all samples containing Ce-exchanged 13X zeolite

Spectroscopic Study of An Icon Painted on Wooden Panel

Russian icon painted on wooden panel analyzed in this work is interesting for art historians because there is no precise information in which workshops it was made or who the author was. Similar icons are often found in churches and monasteries in our region. In order to obtain information about materials used for creation of investigated icon two micro-analytical techniques were used: Energy-Dispersive X-Ray Fluorescence spectroscopy (EDXRF) and micro-Raman spectroscopy. Obtained results confirmed presence of following materials: lead-white, vermilion, minium, ultramarine, brown and green earth pigments and silver in combination with yellow organic varnish, which served to an iconographer for gilding. Ground layer was made of calcite. Blue pigment ultramarine was probably used for blue colour as well as for obtaining particulars hues in several parts of the paint layer. This can be important information for further research concerning particular workshop in which the icon was made. Identified materials are typical for Russian iconography of the 19th century

A review of recent perspectives on biomechanical risk factors associated with anterior cruciate ligament injury

There is considerable evidence to support a number of biomechanical risk factors associated with non-contact anterior cruciate ligament (ACL) injury. This paper aimed to review these biomechanical risk factors and highlight future directions relating to them. Current perspectives investigating trunk position and relationships between strength, muscle activity and biomechanics during landing/cutting highlight the importance of increasing hamstring muscle force during dynamic movements through altering strength, muscle activity, muscle length and contraction velocity. In particular, increased trunk flexion during landing/cutting and greater hamstring strength are likely to increase hamstring muscle force during landing and cutting which have been associated with reduced ACL injury risk. Decision making has also been shown to influence landing biomechanics and should be considered when designing tasks to assess landing/cutting biomechanics. Coaches should therefore promote hamstring strength training and active trunk flexion during landing and cutting in an attempt to reduce ACL injury risk.Peer reviewe

Clar Sextet Analysis of Triangular, Rectangular and Honeycomb Graphene Antidot Lattices

Pristine graphene is a semimetal and thus does not have a band gap. By making a nanometer scale periodic array of holes in the graphene sheet a band gap may form; the size of the gap is controllable by adjusting the parameters of the lattice. The hole diameter, hole geometry, lattice geometry and the separation of the holes are parameters that all play an important role in determining the size of the band gap, which, for technological applications, should be at least of the order of tenths of an eV. We investigate four different hole configurations: the rectangular, the triangular, the rotated triangular and the honeycomb lattice. It is found that the lattice geometry plays a crucial role for size of the band gap: the triangular arrangement displays always a sizable gap, while for the other types only particular hole separations lead to a large gap. This observation is explained using Clar sextet theory, and we find that a sufficient condition for a large gap is that the number of sextets exceeds one third of the total number of hexagons in the unit cell. Furthermore, we investigate non-isosceles triangular structures to probe the sensitivity of the gap in triangular lattices to small changes in geometry

Properties of ZnO/ZnAl2_2O4_4 composite PEO coatings on zinc

Recently the successful formation of PEO coatings on zinc in a phosphate aluminate electrolyte was shown. The produced composite coatings contain various mixtures of ZnO and ZnAl$_2$O$_4$. In frame of the current study, the properties of the formed coatings including adhesion/cohesion, wear, corrosion and photocatalytic activity were analysed to identify possible applications. However, the coatings show internal porosity and a sponge-like structure. Thus the cohesion within the coating is quite low. Pull-off tests have demonstrated clear rupture within the PEO layer at strength values as low as 1 MPa. The photocatalytic activity is limited, in spite of the formation of a higher amount of ZnO at shorter treatment times. Interestingly, the composite coatings of ZnO and higher amounts of ZnAl$_2$O$_4$ spinel showed a higher activity, but not sufficient for fast and effective catalytic cleaning applications

Cellular automaton supercolliders

Gliders in one-dimensional cellular automata are compact groups of non-quiescent and non-ether patterns (ether represents a periodic background) translating along automaton lattice. They are cellular-automaton analogous of localizations or quasi-local collective excitations travelling in a spatially extended non-linear medium. They can be considered as binary strings or symbols travelling along a one-dimensional ring, interacting with each other and changing their states, or symbolic values, as a result of interactions. We analyse what types of interaction occur between gliders travelling on a cellular automaton `cyclotron' and build a catalog of the most common reactions. We demonstrate that collisions between gliders emulate the basic types of interaction that occur between localizations in non-linear media: fusion, elastic collision, and soliton-like collision. Computational outcomes of a swarm of gliders circling on a one-dimensional torus are analysed via implementation of cyclic tag systems

Comparison of three techniques for genetic estimation ofeffective population size in a critically endangered parrot

Understanding the current population size of small, spatially aggregating populations of species is essential for their conservation. Reliable estimates of the effective population size (Ne) can be used to provide an early warning for conservation managers of the risks to genetic viability of small populations. Critically endangered, migratory swift parrots Lathamus discolor exist in a single panmictic population in Australia. In their Tasmanian breeding range, they are at severe risk of predation by introduced sugar gliders, exacerbated by deforestation. We used three genetic approaches to estimate Ne using DNA samples genotyped by microsatellite markers and existing life-history data of swift parrots. Based on all samples, we revealed small contemporary Ne estimates across methods (range: 44-140), supporting the need to urgently address threatening processes. Using the 0.5 Ne/N ratio calculated from demographic data suggests that the minimum potential contemporary population size is below 300 individual swift parrots. This is considerably lower than the published estimates derived from expert elicitation, and accords with modeled estimates of extinction risk in this species. Our study has important implications for other threatened species with unknown population sizes and demonstrates that by utilizing available genetic data, reasonable estimates of Ne can be derived.This work was funded by the Loro Parque Fundaci on, theAustralian Research Council (DP140104202), and a crowd-funding campaign“The parrot, the possum and the parda-lote”. This research also received support from theAustralian Government’s National Environmental ScienceProgram through the Threatened Species Recovery Hub, andfrom Australia Awards through the Endeavour Scholarshipsand Fellowships (ERF-PDR-6086-2017

In-situ observation of the formation of laser-induced periodic surface structures with extreme spatial and temporal resolution

Irradiation of solid surfaces with intense ultrashort laser pulses represents a unique way of depositing energy into materials. It allows to realize states of extreme electronic excitation and/or very high temperature and pressure, and to drive materials close to and beyond fundamental stability limits. As a consequence, structural changes and phase transitions often occur along unusual pathways and under strongly non-equilibrium conditions. Due to the inherent multiscale nature - both temporally and spatially - of these irreversible processes their direct experimental observation requires techniques that combine high temporal resolution with the appropriate spatial resolution and the capability to obtain good quality data on a single pulse/event basis. In this respect fourth generation light sources, namely short wavelength, short pulse free electron lasers (FELs) are offering new and fascinating possibilities. As an example, this chapter will discuss the results of scattering experiments carried at the FLASH free electron laser at DESY (Hamburg, Germany), which allowed us to resolve laser-induced structure formation at surfaces on the nanometer to sub-micron length scale and in temporal regimes ranging from picoseconds to several nanoseconds with sub-picosecond resolution