Acoustic measures of glottalization in Czech

Hlasivkový ráz na začátku slova před vokálem je v češtině užívaný jako hraniční signál. Zatímco jeho kontextuální výskyt je predikovatelný, není vždy realizován. Navíc není vždy realizován jako kanonická hlasivková explozíva. Akustické parametry, které by kvanitifkovaly a identifikovaly rozličné typy rázů, byly vybrány na základě průzkumu literatury a exploratorní datové analýzy. Tyto akustické parametry jsou následně použity v kategorizačním modelu strojového učení. Výsledky ukazují, že i s menším počtem parametrů je možné získat uspokojivé výsledky, a tím pádem jsou tyto parametry považovány za vhodné pro charakterizaci rázů. akustika parametry kategorizace ráz hlasivková explozívaWord-initial vowel glottalization is used in Czech as a boundary signal. While its contextual occurrence is predictable, it is not always realized. In addition, it is not always realized as a canonical glottal stop. Acoustic parameters which would quantify and identify the various types of glottalizations are selected based on literature research and exploratory data analysis. These acoustic parameters are then used in a machine learning categorization model. Results show that with a small number of parameters, satisfactory results can be obtained, and thus these parameters are deemed suitable in characterizing these glottalizations. acoustics parameters categorization glottalization glottal stopFonetický ústavInstitute of PhoneticsFilozofická fakultaFaculty of Art

Vanadium redox flow battery - membrane selection and characterization

The increasing share of renewable energy sources in the total energy production emphasizes the need for a reliable and cheap stationary energy storage. Such a tool allows to baffle hardly predictable non-stabilities in output power of photovoltaics or wind turbines on the power transmission level. Vanadium redox flow battery (VRFB) appears as a promising solution for the stationary energy storage as it offers high efficiency (80% DC-DC), foolproof arrangement of decoupled power (kW) to capacity (kWh), extended durability and fast demand response. However, the broader commercialization of the technology is still obstructed by relatively high investment costs. In redox flow batteries, electrolytes are not stored in the battery construction but in an external tank and are continuously pumped through the battery stack where electrical energy is transformed on inert electrodes into chemical during charging and conversely during discharging. Battery stack is composed of several serially connected cells. Each cell consists of positive and negative half-cells which are mutually separated typically by ion-exchange membrane. In VRFB, both electrolytes comprises vanadium salts dissolved in diluted sulfuric acid (i.e., (VO2)2SO4 and VOSO4 in positive electrolyte and VSO4 and V2(SO4)3 in negative electrolyte). Price of the ion-exchange membrane, one of the key components of the battery stack, represents 5 - 15 % of the overall costs typically. Long term durability of membrane in acidic electrolytes is vitally necessary for VRFB function. Please click Additional Files below to see the full abstract

Regulatory Approaches to Facebook and Other Social Media Platforms: Towards Platforms Design Accountability

The paper represents a contribution to the ongoing discussion on regulating social media platforms (SMP) and especially Facebook, mostly fueled by a recent series of scandals such as Cambridge Analytica, which highlighted the recognized problem of Facebook’s lack of accountability. In response to the scandal, which coincided with long-expected wide-scale implementation of the EU’s GDPR, Facebook introduced a series of measures on its platform, such as improved traceability of advertisers, or greater power over one’s own data. Besides, Facebook was put under scrutiny of competition law authorities, mainly the German Bundeskartellamt. Taking into consideration all the regulatory approaches, the question remains whether sufficiently effective design for holding the SMPs accountable has been established or not. In the paper, we first outline the accountability issues SMPs currently face, namely the data handling and privacy issue, the platforms’ impact on political processes, or related monopolistic positioning. We ascertain that common denominator of these issues is the platforms’ design, which is created to achieve business objectives, while imposing substantial negative externalities on the society. Alongside, we review the platforms’ reactions, i.e. the self-regulatory measures adopted by the platforms in 2017–2018. We also specifically focus on the evaluation of the competition law as one instrument of regulating certain aspects of the platforms, especially in light of the recent German Bundeskartellamt decision on Facebook. We claim that most of the measures and current instruments, although improving the lack of accountability, fall short of addressing the core issue of Facebook’s status – absence of scrutiny over the platform’s design

Tribute to Professor James Moliterno

A tribute to Professor James Moliterno, who served on the faculty of the Washington and Lee University School of Law from 2009 to 2022. An internationally active scholar of legal and judicial ethics, Moliterno was most recently the Vincent Bradford Professor of Law. For 21 years prior to joining W&L, he was a member of the faculty of the William & Mary Law School

Enhanced performance of polybenzimidazole-based high temperature proton exchange membrane fuel cell with gas diffusion electrodes prepared by automatic catalyst spraying under irradiation technique

Gas diffusion electrodes (GDEs) prepared by a novel automatic catalyst spraying under irradiation (ACSUI) technique are investigated for improving the performance of phosphoric acid (PA)-doped polybenzimidazole (PBI) high temperature proton exchange membrane fuel cell (PEMFC). The physical properties of the GDEs are characterized by pore size distribution and scanning electron microscopy (SEM). The electrochemical properties of the membrane electrode assembly (MEA) with the GDEs are evaluated and analyzed by polarization curve, cyclic voltammetry (CV) and electrochemistry impedance spectroscopy (EIS). Effects of PTFE binder content, PA impregnation and heat treatment on the GDEs are investigated to determine the optimum performance of the single cell. At ambient pressure and 160 o C, the maximum power density can reach 0.61 W cm-2, and the current density at 0.6 V is up to 0.38 A cm-2, with H /air and a platinum loading of 0.5 mg cm-2 on both electrodes. The MEA with the GDEs shows good stability for fuel cell operating in a short term durability test.Web of Scienc

Proceedings of the 12th International Conference on Kinanthropology

Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students

Graphitic Carbon Nitride as a Catalyst Support in Fuel Cells and Electrolyzers

Electrochemical power sources such as polymer electrolyte membrane fuel cells (PEMFCs) require the use of precious metal catalysts, which are deposited as nanoparticles onto supports in order to minimize their mass loading and therefore cost. State-of-the-art/commercial supports are based on forms of carbon black. However, carbon supports present disadvantages including corrosion in the operating fuel cell environment and loss of catalyst activity. Here we review recent work examining the potential of different varieties of graphitic carbon nitride (gCN) as catalyst supports, highlighting their likely benefits, as well as the challenges associated with their implementation. The performance of gCN and hybrid gCN-carbon materials as PEMFC electrodes is discussed, as well as their potential for use in alkaline systems and water electrolyzers. We illustrate the discussion with examples taken from our own recent studies.This project has received funding from the European Union’s Graphene Flagship under Horizon 2020 research and innovation programme grant agreement No. 696656 – GrapheneCore1 and from the EPSRCEP/L017091/1. C.M. acknowledges the award of a Royal Society University Research Fellowship by the UK Royal Society