Towards the Standard Model spectrum from elliptic Calabi-Yau

We show that it is possible to construct supersymmetric three-generation models of Standard Model gauge group in the framework of non-simply-connected elliptically fibered Calabi-Yau, without section but with a bi-section. The fibrations on a cover Calabi-Yau, where the model has 6 generations of SU(5) and the bundle is given via the spectral cover description, use a different description of the elliptic fibre which leads to more than one global section. We present two examples of a possible cover Calabi-Yau with a free involution: one is a fibre product of rational elliptic surfaces $dP_9$; another example is an elliptic fibration over a Hirzebruch surface. There we give the necessary amount of chiral matter by turning on in the bundles a further parameter, related to singularities of the fibration and the branching of the spectral cover.Comment: 31 pages, 1 eps-figure, reference added, bundle parameters for dP9 model change

Anomalous interaction between vortices and nanomagnets

We study a thin film system consisting of a superconducting and a magnetic film, where the superconductor contains a vortex and the magnetic film a nanomagnet. We find that if the magnetic film has planar anisotropy, the vortex induces a magnetization distribution, and its interaction with the nanomagnet crosses over from attractive to repulsive at short distances.Comment: 5 page

Quantum geometry of elliptic Calabi-Yau manifolds

We study the quantum geometry of the class of Calabi-Yau threefolds, which are elliptic fibrations over a two-dimensional toric base. A holomorphic anomaly equation for the topological string free energy is proposed, which is iterative in the genus expansion as well as in the curve classes in the base. T-duality on the fibre implies that the topological string free energy also captures the BPS-invariants of D4-branes wrapping the elliptic fibre and a class in the base. We verify this proposal by explicit computation of the BPS invariants of 3 D4-branes on the rational elliptic surface.Comment: 63 pages, 4 figure

Single-photon emission from Ni-related color centers in CVD diamond

Color centers in diamond are very promising candidates among the possible realizations for practical single-photon sources because of their long-time stable emission at room temperature. The popular nitrogen-vacancy center shows single-photon emission, but within a large, phonon-broadened spectrum (~100nm), which strongly limits its applicability for quantum communication. By contrast, Ni-related centers exhibit narrow emission lines at room temperature. We present investigations on single color centers consisting of Ni and Si created by ion implantation into single crystalline IIa diamond. We use systematic variations of ion doses between 10^8/cm^2 and 10^14/cm^2 and energies between 30keV and 1.8MeV. The Ni-related centers show emission in the near infrared spectral range (~770nm to 787nm) with a small line-width (~3nm FWHM). A measurement of the intensity correlation function proves single-photon emission. Saturation measurements yield a rather high saturation count rate of 77.9 kcounts/s. Polarization dependent measurements indicate the presence of two orthogonal dipoles.Comment: 8 pages, published in conference proceedings of SPIE Photonics Europe 201

A radio air shower surface detector as an extension for IceCube and IceTop

The IceCube neutrino detector is built into the Antarctic ice sheet at the South Pole to measure high energy neutrinos. For this, 4800 photomultiplier tubes (PMTs) are being deployed at depths between 1450 and 2450 meters into the ice to measure neutrino induced charged particles like muons. IceTop is a surface air shower detector consisting of 160 Cherenkov ice tanks located on top of IceCube. To extend IceTop, a radio air shower detector could be built to significantly increase the sensitivity at higher shower energies and for inclined showers. As air showers induced by cosmic rays are a major part of the muonic background in IceCube, IceTop is not only an air shower detector, but also a veto to reduce the background in IceCube. Air showers are detectable by radio signals with a radio surface detector. The major emission process is the coherent synchrotron radiation emitted by e+ e- shower particles in the Earths magnetic field (geosynchrotron effect). Simulations of the expected radio signals of air showers are shown. The sensitivity and the energy threshold of different antenna field configurations are estimated.Comment: 4 pages, 6 figures, to be published in Proceedings of the 30th International Cosmic Ray Conferenc

High-speed Steam Turbine

Předkládaná diplomová práce je zaměřena na konstrukci rychloběžné parní turbíny pro parametry spalovny komunálního odpadu v Brně. V úvodní části diplomové práce je krátce shrnut historický vývoj, transformační proces a pracovní princip parní turbíny. V návaznosti na úvodní kapitoly je detailně rozebráno řešení akčního a reakčního lopatkování, včetně popisu průběhu expanze v i-s diagramu a vyjádření základních vzorců pro výpočet účinnosti. Ve stěžejní části diplomové práce jsou nejprve rozebrány možné koncepční varianty turbosoustrojí pro zadané parametry. Na základě zvolené koncepce je sestaven algoritmus termodynamického výpočtu pro jednotlivá tělesa turbíny. V závěru výpočetní části je uveden zjednodušený výpočet převodovky. Na základě výpočetní části jsou sestaveny konstrukční výkresy převodovek a podélných řezů všech částí turbosoustrojí.Main aim of presented master thesis is focused on construction of high speed steam turbine. Steam turbine is designed based on parameters of waste incineration plant in Brno. First chapters shortly summarized historical development, transformation process and work principal of steam turbine. Consequently on first captures is in depth described impulse and reaction blading including expansion in i-s diagram and basic equations for efficiency calculations. In major part of master thesis is firstly discussed conceptual possibilities of turbine application for given parameters. Based on chosen concept is compiled algorithm for thermodynamic calculation for each turbine module. Simplify calculation of gearbox is included as well. Based on calculations are compiled construction drawings of all parts of steam turbine.

Understanding the Uncertainty Loop of Human-Robot Interaction

Recently the field of Human-Robot Interaction gained popularity, due to the wide range of possibilities of how robots can support humans during daily tasks. One form of supportive robots are socially assistive robots which are specifically built for communicating with humans, e.g., as service robots or personal companions. As they understand humans through artificial intelligence, these robots will at some point make wrong assumptions about the humans' current state and give an unexpected response. In human-human conversations, unexpected responses happen frequently. However, it is currently unclear how such robots should act if they understand that the human did not expect their response, or even showing the uncertainty of their response in the first place. For this, we explore the different forms of potential uncertainties during human-robot conversations and how humanoids can, through verbal and non-verbal cues, communicate these uncertainties