Metal-free C-H functionalisation methods

Previously held under moratorium from 1 December 2016 until 6 December 2021This thesis describes the development of two metal-free C–H functionalisation methods which encompass oxidations of sp³- and sp²-hybridised C–H bonds.Chapter 1 provides a brief introduction to the rapidly growing area of C–H functionalisation and outlines selected metal-catalysed and metal-free C–H functionalisation methods. Chapter 2 describes the development of a novel metal-free C–H functionalisation method of alkanes, from concept, through initial investigations, optimisation and substrate scope to mechanistic studies. Chapter 3 gives a detailed account of the development and mechanistic investigations of peroxide-mediated C–H functionalisation method exclusive to aromatic C–H bonds. Chapter 4 presents the experimental data obtained in the process of developing the new methodologies described herein. Chapter 5 contains an appendix. Chapter 6 contains a bibliography.This thesis describes the development of two metal-free C–H functionalisation methods which encompass oxidations of sp³- and sp²-hybridised C–H bonds.Chapter 1 provides a brief introduction to the rapidly growing area of C–H functionalisation and outlines selected metal-catalysed and metal-free C–H functionalisation methods. Chapter 2 describes the development of a novel metal-free C–H functionalisation method of alkanes, from concept, through initial investigations, optimisation and substrate scope to mechanistic studies. Chapter 3 gives a detailed account of the development and mechanistic investigations of peroxide-mediated C–H functionalisation method exclusive to aromatic C–H bonds. Chapter 4 presents the experimental data obtained in the process of developing the new methodologies described herein. Chapter 5 contains an appendix. Chapter 6 contains a bibliography

Solitons and vortices in ultracold fermionic gases

We investigate the possibilities of generation of solitons and vortices in a degenerate gas of neutral fermionic atoms. In analogy with, already experimentally demonstrated, technique applied to gaseous Bose-Einstein condensate we propose the phase engineering of a Fermi gas as a practical route to excited states with solitons and vortices. We stress that solitons and vortices appear even in a noninteracting fermionic gas. For solitons, in a system with sufficiently large number of fermions and appropriate trap configuration, the Pauli blocking acts as the interaction between particles.Comment: 4 pages, 5 figures many new result

Post-outburst spectra of a stellar-merger remnant of V1309 Scorpii: from a twin of V838 Monocerotis to a clone of V4332 Sagittarii

We present optical and infrared spectroscopy of V1309 Sco, an object that erupted in 2008 in a stellar-merger event. During the outburst, V1309 Sco displayed characteristics typical of red transients, a class of objects similar to V838 Mon. Our observations were obtained in 2009 and 2012, i.e. months and years after the eruption of V1309 Sco, and illustrate severe changes in the remnant, mainly in its circumstellar surroundings. In addition to atomic gas observed in earlier epochs, we identified molecular bands of TiO, VO, H$_2$O, ScO, AlO, and CrO. The infrared bands of CrO we analyse are the first astronomical identification of the features. Over the whole period covered by our data, the remnant was associated with a cool ($\lesssim$1000 K) outflow with a terminal velocity of about 200 km/s. Signatures of warmer atomic gas, likely to be still dissipating the energy of the 2008 outburst, dramatically decreased their brightness between 2009 and 2012. In addition, the source of optical continuum disappeared sometime before 2012, likely owing to the formation of new dust. The final stage of V1309 Sco's evolution captured by our spectra is an object remarkably similar to an older red transient, V4332 Sgr. In addition to providing a detailed view on the settling of the eruptive object, the observations presented here reinforce the conclusion that all the Galactic red transients are a manifestation of the same phenomenon, i.e. a stellar merger. The late spectra of V1309 Sco also suggest peculiarities in the chemical composition of the remnant, which still need to be explored.Comment: to appear in A&

ACCURACY ANALYSIS OF THE CURVED PROFILE MEASUREMENT WITH CMM: A CASE STUDY

In the paper, analysis of the curved profile measurement accuracy is described. Since there was no CAD model or other reference profile for the measured detail, the first step was to generate the reference contour of the cam using the technical drawing and tolerance requirements. The test campaign consisted of three experiments aimed at determining the effect of scanning velocity on the results of form deviation δ measurement, evaluation of deviation δ measurement uncertainty and the measurement repeatability. The scanning time was checked, too. The obtained results demonstrated feasibility of the chosen CMM and measurement strategy. It was found also that the measurement uncertainty did not depend on the scanning sampling step from 0.05 to 0.2 mm, and the true measurement time was for 30-40% longer than that expected from the nominal scanning velocity

DESIGN AND CALIBRATION OF THE SYSTEM SUPERVISING BELT TENSION AND WEAR IN AN INDUSTRIAL FEEDER

In the paper, the issue of the supervision of belt tension and wear in industrial feeder is addressed. The designed system is based on strain gauges that are built into the roller and are subject to the belt pressure at each revolution. In order to assess the effectiveness of this system, calibration and uncertainty analysis was performed. As a result, it was demonstrated that the main source of uncertainty was the function of approximation, while the others were orders of magnitude smaller. The final function provided results with accuracy of ca. 10% of actually measured value, which was assumed to be a good result for this particular industrial application

Analysis of the planar point identification accuracy in CMM measurements

The paper presents the results of the investigations on the direction-dependent accuracy of the point identification during contact probe measurements with a coordinate measuring machine (CMM). Considering the contact point identified by an orthogonal to the surface probe movement, the transformation of coordinates was made in order to calculate the displacement of the measured point. As a result, the positioning accuracy was estimated in three axes. The experiments demonstrated a strong dependence of the displacement on the declination angle. Moreover, it was found that the directional surface texture which provided different roughness in perpendicular directions, had an impact on the positioning accuracy.Web of Science2218art. no. 700