Suchergebnisse

In order to achieve a true democracy, this book explores different political and philosophical traditions that do not necessarily seem to speak in unison, notwithstanding their common goal: to propose an alternative to hard-line neo-liberalism, Western hegemony and coloniality.

Institute of Solid State Physics, University of Latvia (SJZ/2016/26); Ministry of Education and Science, Republic of Latvia (MultIfunctional Materials and composItes, photonicS and nanotechnology (IMIS2)). We acknowledge Dr. Anatolijs Sarakovskis at Institute of Solid State Physics for the XPS measurements. ; In this paper we describe the principles of operation as well as the fabrication and testing steps of an all-organic waveguide modulator. The modulator comprises an SU-8 core and an electro-optic host-guest polymer cladding. The polymer properties are tuned in order to achieve single mode operation. We used direct-write laser lithography in two steps for the preparation of the devices. The electro-optic coefficient of the polymer is estimated from observing the modulation of the device operated in push-pull mode. ; Latvijas Universitate, SJZ/2016/26; Ministry of Education and Science, Republic of Latvia IMIS2; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

In this paper, we present the results of the study of the statistics of pulse energy fluctuations in a Raman laser under optical pump by the multimode nanosecond pulses. A system of coupled differential equations for slowly varying envelopes of the pump field and first three Stokes lines was integrated numerically with taking into account spatial inhomogeneity of the pump beam, spontaneous noise, and optical feedback. Data of the numerical simulation revealed a sharp increase in the fluctuation amplitude in the nonlinear regime of Raman frequency conversion when the optical length of the Raman cavity was matched with the cavity length of the multimode pump laser. At a mean 1st Stokes conversion efficiency of 3.5–3.8 %, the calculations showed an increase in the coefficient of variation (CV) of a random value from 9 % to 118 %. In the linear regime of Raman frequency conversion, when the conversion efficiency was 0.2–0.03 %, a further increase in the CV value up to 270–500 % was predicted. It is also numerically shown that the fluctuation statistics under the conditions of the cavity length matching is essentially non-Gaussian and described by the L-type probability density distributions (PDDs) with long tails and maxima located near zero. The numerical data were quantitatively confirmed by an experiment for a Raman laser on a barium nitrate crystal operated near the Raman threshold, when the 1st Stokes conversion efficiency did not exceed 0.3 %. A Raman cavity was formed by two flat mirrors providing a double-pass pump configuration. The Raman laser was excited by the linearly polarized frequency-doubled radiation of a Q-switched Nd:YAG laser generating multimode pulses with a duration of 7–8 ns. A Raman laser operating regime characterized by the hyperexponential PDDs with CVs reaching 480 %, which is 2–2.5 times higher than those observed earlier for the single-pass conditions of stimulated Raman scattering, was realized.

This book begins with an examination of the numbers of women in physics in English-speaking countries, moving on to examine factors that affect girls and their decision to continue in science, right through to education and on into the problems that women in physics careers face. Looking at all of these topics with one eye on the progress that the field has made in the past few years, and another on those things that we have yet to address, the book surveys the most current research as it tries to identify strategies and topics that have significant impact on issues that women have in the field

I. P., A. K. and A. K. would like to thank the support of the Latvian Council of Science project No. lzp-2019/1-0071. I.P. acknowledges the L'OREAL Baltic "For Women In Science" Program with the support of the Latvian National Commission for UNESCO and the Latvian Academy of Sciences. The experiment at the PETRA III synchrotron was performed within project No. I-20190277 EC. The synchrotron experiments have been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. ; The influence of zinc ions on the thermochromic properties of polycrystalline CuZnMoO (=0.10, 0.50, 0.90) solid solutions was studied by X-ray absorption spectroscopy at the Cu, Zn and Mo K-edges. Detailed structural information on the local environment of metal ions was obtained from the simultaneous analysis of EXAFS spectra measured at three metal absorption edges using the reverse Monte Carlo method. Thermochromic phase transition with the hysteretic behaviour between and phases was observed in Cu0.90Zn0.10MoO solid solution. It was found that the local environment of molybdenum ions is most susceptible to the substitution of copper for zinc and, upon cooling, transforms from tetrahedral MoO to distorted octahedral MoO. --- / / / --- This is the preprint version of the following article:Inga Pudza, Andris Anspoks, Arturs Cintins, Aleksandr Kalinko, Edmund Welter, Alexei Kuzmin, The influence of Zn2+ ions on the local structure and thermochromic properties of Cu1-xZnxMoO4 solid solutions, Materials Today Communications, Volume 28 (2021), 102607, DOI https://doi.org/10.1016/j.mtcomm.2021.102607, which has been published in final form at https://www.sciencedirect.com/science/article/abs/pii/S2352492821005997. ; Latvian Council of Science project No. lzp-2019/1-0071; L'OREAL Baltic "For Women In Science" Program with the support of the Latvian National Commission for UNESCO and the Latvian Academy of Sciences; project No. I-20190277 EC; project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.

This volume comprises the select peer reviewed proceedings of the International Conference on Recent Evolutions in Energy, Drives and e-Vehicles (REED-EV 2022). It aims to provide a comprehensive and broad-spectrum picture of the state-of-the-art research and development in the area of power and energy systems, grid integration, convertor topology, electrification for transport industries, battery storage and energy management systems, system protection, filters and harmonics, among others. This volume will provide a valuable resource for those in academia and industry.

The field of paramagnetic NMR has expanded considerably in recent years, both in solution and the solid state. This review addresses both the theoretical description of paramagnetic NMR, and the way in which it is currently practised. We provide a review of the theory of the NMR parameters of systems in both solution and the solid state. Here we unify the different languages used by the NMR, EPR, quantum chemistry/DFT, and magnetism communities to provide a comprehensive and coherent theoretical description. We cover the theory of the paramagnetic shift and shift anisotropy in solution both in the traditional formalism in terms of the magnetic susceptibility tensor, and using a more modern formalism employing the relevant EPR parameters, such as are used in first-principles calculations. In addition we examine the theory first in the simple non-relativistic picture, and then in the presence of spin-orbit coupling. These ideas are then extended to a description of the paramagnetic shift in periodic solids, where it is necessary to include the bulk magnetic properties, such as magnetic ordering at low temperatures. The description of the paramagnetic shift is completed by describing the current understanding of such shifts due to lanthanide and actinide ions. We then examine the paramagnetic relaxation enhancement, using a simple model employing a phenomenological picture of the electronic relaxation, and again using a more complex state-of-the-art theory which incorporates electronic relaxation explicitly. An additional important consideration in the solid state is the impact of bulk magnetic susceptibility effects on the form of the spectrum, where we include some ideas from the field of classical electrodynamics. We then continue by describing in detail the solution and solid-state NMR methods that have been deployed in the study of paramagnetic systems in chemistry, biology, and the materials sciences. Finally we describe a number of case studies in paramagnetic NMR that have been specifically chosen to highlight how the theory in part one, and the methods in part two, can be used in practice. The systems chosen include small organometallic complexes in solution, solid battery electrode 3 materials, metalloproteins in both solution and the solid state, systems containing lanthanide ions, and multi-component materials used in pharmaceutical controlled-release formulations that have been doped with paramagnetic species to measure the component domain sizes. ; This work was supported by the People Programme (Marie Curie Actions Initial Training Networks (ITN)) of the European Union's Seventh Framework Programme FP7/2007-2013/ under REA grant agreement no. 317127, the "pNMR" project. AJP received funding from the Swedish Research Council (Vetenskapsrådet) (2016-03441).