Linearisations of triangulated categories with respect to finite group actions

Given an action of a finite group on a triangulated category, we investigate under which conditions one can construct a linearised triangulated category using DG-enhancements. In particular, if the group is a finite group of automorphisms of a smooth projective variety and the category is the bounded derived category of coherent sheaves, then our construction produces the bounded derived category of coherent sheaves on the smooth quotient variety resp. stack. We also consider the action given by the tensor product with a torsion canonical bundle and the action of a finite group on the category generated by a spherical object.Comment: 14 pages; comments welcom

Derived equivalent conjugate K3 surfaces

We show that there exist a complex projective K3 surface $X$ and an automorphism of the complex numbers $\sigma$ such that the conjugate K3 surface $X^\sigma$ is a non-isomorphic Fourier-Mukai partner of $X$.Comment: 12 pages; v2: minor changes, mostly correction of typos; v3: added application to Hilbert scheme

Testing iPad in the field: use of a relational database in garbological research

Recording thousands of entries during field research poses a challenge to any field researcher. Contemporary handheld computers offer affordable solutions, which can resolve this challenge. In this paper, we test the iPad tablet computer and FileMaker Go database to conduct garbological research carried out in West Bohemia (Czech Republic). Garbological research based on the collection of data about human waste requires not only efficient tools for recording a vast number of individual garbage items on the spot but also integration of multiple analytical levels in a database. Our research was aimed at household waste to illuminate consumption patterns and mobility of humans and things in contemporary Central European settings. The iPad was used to collect textual and visual data and integrate these in a relational database. We describe our methodology and experience with this kind of technology. The iPad and FileMaker Go proved to be well suited to challenging field conditions in the landfill, data collection was efficient and reliable, the database was flexible because its basic features could be modified in the field, and one could even examine preliminary trends in the data using charts in FileMaker Go. The proposed hardware and software is less efficient for the collection of precise spatial data, preparation of accurate drawings, and for projects in remote areas without good access to an electrical grid

Synthesis of drug nanoparticles using supercritical fluid

Import 05/08/2014Bakalářská práce je zaměřena na přípravu nanočástic léčiv, zejména nanočástic léčiv pomocí superkritických tekutin (SCFs). Cílem této práce je příprava nanočástic kofeinu, aspirinu, nifedipinu a cimetidinu pomocí superkritických tekutin. K přípravě bylo využito komerčně dodávaného přístroje Spe-ed SFE-4 (firma Applied separations). Příprava byla uskutečněna metodou rychlé expanze superkritickou směsí (RESS). Bylo zjištěno, že nanočástice kofeinu lze pomocí tohoto postupu připravit. Dále byly touto metodou připraveny částice aspirinu. Vznik částic nifedipinu a cimetidinu nebyl pozorován. Zároveň bylo zjištěno, že s rostoucí teplotou klesá velikost nanočástic kofeinu a vlivem teploty lze ovlivnit i tvar výsledných částic. Přístroj Spe-ed SFE-4 je využitelný k výrobě částic a nanočástic léčiv metodou RESS.The bachelor thesis is focused on preparation of drugs nanoparticles, especially using supercritical fluids (SCFs). The aim of this thesis is preparation of nanoparticles of caffeine, aspirin, nifeldipine and cimetidine using supercritical fluids. For preparation was used an Applied Separations Spe-ed SFE-4 device. As a preparation method was used rapid expansion of supercritical solution (RESS). It was found that using this procedure, nanoparticles of caffeine and particles of aspirin can be prepared. No signs of nifedipine and cimetidine nanoparticles formation were observed. Also was discovered that with rising temperature, the size of caffeine and aspirin nanoparticles is decreasing, thus, it is possible to affect the size of nanoparticles by controlling the temperature. The Spe-ed SFE-4 is capable of preparation of drugs nanoparticles using RESS method.9360 - Centrum nanotechnologiívýborn

Development of Parameters for Numerical Modeling of Geomechanical Systems "Excavation - rock mass - support"

The airway drift of “Trudovskaya” mine of “DTEK” company was chosen as an object of research because of strong effect of rock pressure and water influence in the excavation. The main forms of rock pressure in the excavation are rock falling from the side and the roof, and intense swelling. The main purpose of numerical simulation is to justify the parameters of the support systems of the excavations, which are exploited in the “Trudovskaya” mine. As a test model was accepted a model which reflects a real situation in the vicinity of excavation

Measuring the Effect of Negative Political Advertising on Voter Turnout

Many scholars have explored the effects of negative political advertising on voter turnout, some arguing that it suppresses turnout, others that it stimulates it. These two views represent the demobilization and stimulation hypotheses, respectively. A third school argues no meaningful relationship exists between the two variables. Despite extensive coverage in the literature, a newer contribution is needed to accurately assess the issue within a more modern context. I utilize data from the 2020 ANES Time Series Study to determine the extent to which exposure to negative political advertising affects voter turnout. I find the effect is slightly depressive, although minimal and less extreme than past contributions to the literature have suggested. These findings cast doubt on the strength of the relationship between negative political advertising and voter turnout

Fourier-Mukai partners of canonical covers of bielliptic and Enriques surfaces

We prove that the canonical cover of an Enriques surface does not admit non-trivial Fourier-Mukai partners. We also show that the canonical cover of a bielliptic surface has at most one non-isomorphic Fourier-Mukai partner. The first result is then applied to birational Hilbert schemes of points and the second to birational generalised Kummer varieties. An appendix establishes that there are no exceptional or spherical objects in the derived category of a bielliptic surface.Comment: 10 pages; v2: corrected a reference and some typo