Publications by authors named "Robert Kovacs"

LEDs (Light-Emitting Diodes) are widely applied not only in decorative illumination but also in everyday lighting in buildings, flats, public areas, and automotive fields. These application areas often mean harsh environments, for example, regarding the humidity content of the surrounding air: besides outdoor and automotive illumination, even the household use cases (kitchen, bathroom, cellar) may represent extreme temperature and humidity variations (often reaching relative humidity levels close to 100%) for these devices; thus, their reliability behaviour in such circumstances should be better understood. Thermally activated processes were studied in several previous publications, but less information is available regarding high-humidity environmental tests.

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Hydraulic selection is a key feature of aerobic granular sludge (AGS) systems but existing aerobic granular sludge (AGS) models neglect those mechanisms: gradients over reactor height (H, selective removal of slow settling sludge, etc. This study aimed at evaluating to what extent integration of those additional processes into AGS models is needed, i.e.

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Nowadays, the disinfection of classrooms, shopping malls, and offices has become an important part of our lives. One of the most effective disinfection methods is ultraviolet (UV) radiation. To ensure the disinfection device has the required wavelength spectrum, we need to measure it with dedicated equipment.

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Background: Facebook can be a suitable platform for public health interventions. Facebook users can express their reaction to the given social media content in many ways using interaction buttons. The analysis of these interactions can be advantageous in increasing reach and engagement of public health interventions.

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Imatinib mesylate (IM) is an anticancer drug that belongs to tyrosine kinase inhibitors. We report the results of the first investigation of the chronic exposure of zebrafish (Danio rerio) to IM. The exposure to IM (0.

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The present Special Issue, 'Entropy and Non-Equilibrium Statistical Mechanics', consists of seven original research papers [...

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There has been much interest in semiconductor superlattices because of their low thermal conductivities. This makes them especially suitable for applications in a variety of devices for the thermoelectric generation of energy, heat control at the nanometric length scale, etc. Recent experiments have confirmed that the effective thermal conductivity of superlattices at room temperature have a minimum for very short periods (in the order of nanometers) as some kinetic calculations had anticipated previously.

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On the example of the Poynting-Thomson-Zener rheological model for solids, which exhibits both dissipation and wave propagation, with nonlinear dispersion relation, we introduce and investigate a finite difference numerical scheme. Our goal is to demonstrate its properties and to ease the computations in later applications for continuum thermodynamical problems. The key element is the positioning of the discretized quantities with shifts by half space and time steps with respect to each other.

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The recent results attained from a thermodynamically conceived numerical scheme applied on wave propagation in viscoelastic/rheological solids are generalized here, both in the sense that the scheme is extended to four spacetime dimensions and in the aspect of the virtues of a thermodynamical approach. Regarding the scheme, the arrangement of which quantity is represented where in discretized spacetime, including the question of appropriately realizing the boundary conditions, is nontrivial. In parallel, placing the problem in the thermodynamical framework proves to be beneficial in regards to monitoring and controlling numerical artefacts-instability, dissipation error, and dispersion error.

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Article Synopsis
  • * It contained an error that was not corrected in the first release.
  • * The updated version aims to address and rectify that mistake.
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We describe 2 cases in coronavirus disease patients in France involving presumed thrombotic stroke that occurred during ongoing anticoagulation treatment for atrial fibrillation stroke prophylaxis; 1 patient had positive antiphospholipid antibodies. These cases highlight the severe and unique consequences of coronavirus disease-associated stroke.

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Objectives: To establish national reference levels (RLs) in interventional procedures under CT guidance as required by the 2013/59/Euratom European Directive.

Methods: Seventeen categories of interventional procedures in thoracic, abdominopelvic, and osteoarticular specialties (percutaneous infiltration, vertebroplasty, biopsy, drainage, tumor destruction) were analyzed. Total dose length product (DLP), number of helical acquisitions (NH), and total DLP for helical, sequential, or fluoroscopic acquisitions were recorded for 10 to 20 patients per procedure at each center.

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There are limits of validity of classical constitutive laws such as Fourier and Navier-Stokes equations. Phenomena beyond those limits have been experimentally found many decades ago. However, it is still not clear what theory would be appropriate to model different non-classical phenomena under different conditions considering either the low-temperature or composite material structure.

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Introduction: The possibility of successful smoking cessation is increased by early initiation. Therefore, promoting smoking cessation at early age (especially among 14-35-year-olds) has a key role in reducing tobacco use prevalence. Facebook is one of the most popular websites among adolescents and young adults which can be used for age-specific smoking cessation support.

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Environmental estrogens are a serious concern worldwide due to their ubiquity and adverse ecotoxicological and health effects. Chemical structure of these substances is highly diverse, therefore estrogenicity cannot be predicted on the basis of molecular structure. Furthermore, estimation of estrogenicity of environmental samples based on chemical analytics of suspects is difficult given the complex interaction of chemicals and the impact on estrogenicity.

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The non-Fourier heat conduction phenomenon on room temperature is analyzed from various aspects. The first one shows its experimental side, in what form it occurs, and how we treated it. It is demonstrated that the Guyer-Krumhansl equation can be the next appropriate extension of Fourier's law for room-temperature phenomena in modeling of heterogeneous materials.

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The accuracy of a biofilm reactor model depends on the extent to which physical system conditions (particularly bulk-liquid hydrodynamics and their influence on biofilm dynamics) deviate from the ideal conditions upon which the model is based. It follows that an improved capacity to model a biofilm reactor does not necessarily rely on an improved biofilm model, but does rely on an improved mathematical description of the biofilm reactor and its components. Existing biofilm reactor models typically include a one-dimensional biofilm model, a process (biokinetic and stoichiometric) model, and a continuous flow stirred tank reactor (CFSTR) mass balance that [when organizing CFSTRs in series] creates a pseudo two-dimensional (2-D) model of bulk-liquid hydrodynamics approaching plug flow.

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This work establishes the zebrafish embryo model for ionizing radiation (IR) modifier research and also evaluates the protective effect of l-alpha glycerylphosphorylcholine (GPC). Embryos were exposed to a single-fraction whole-body gamma irradiation (5, 10, 15, and 20 Gy) at different postfertilization time points and were serially assessed for viability and macro- and micromorphologic abnormalities. After toxicity evaluation, 194 μM of GPC was added for certain groups with 3-h incubation before the radiation.

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Ultraviolet (UV) filters are commonly used compounds in personal care products and polymer based materials, as they can absorb solar energy in the UVA and UVB spectrum. However, they are able to bind to hormone receptors and have several and different types of hormonal activities determined by in vitro assays. One of the aims of this work was to measure the hormonal and cytotoxic activities of four frequently used UV filters using bioluminescence based yeast test organisms.

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The acute and sub-chronic effects of four cytostatic drugs-5-fluorouracil (5-FU), cisplatin (CisPt), etoposide (ET) and imatinib mesylate (IM)-on zebrafish (Danio rerio) were investigated. Acute tests were carried out in a static system in accordance with the OECD guideline 203 for adult fish and the draft guideline for fish embryos (FET test) in order to find the LC50 values of the four cytostatic drugs. Early-life stage toxicity test on zebrafish was conducted according the OECD guideline 210 using the cytostatic drugs 5-FU and IM in a semistatic system with the objective of investigating the sub-chronic effects of the cytostatic drugs on fish.

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Residues of anti-neoplastic drugs represent new and emerging pollutants in aquatic environments. Many of these drugs are genotoxic, and it has been postulated that they can cause adverse effects in aquatic ecosystems. 5-Fluorouracil (5-FU) is one of the most extensively used anti-neoplastic drugs in cancer therapy, and this article describes the results of the first investigation using a two-generation toxicity study design with zebrafish (Danio rerio).

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Zearalenone (ZEA, F2) is one of the most common mycotoxins and the only known mycoestrogen. It enters the food and feed chain from contaminated cereals and infiltrates into sewage or natural waters posing potential threat to exposed livestock, wildlife and humans. Therefore evaluation of its biological effects is of international importance.

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Disinfection of raw water is essential to the production of drinking water. However, by-products of disinfection may exert toxic effects. The potential toxic effects of two of these compounds, 4-ethylbenzaldehyde (EBA) and 2,4-difluoroaniline (DFA) were investigated using the zebrafish (Danio rerio) model.

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Maternal gene products drive early embryogenesis almost exclusively until the mid blastula transition (MBT) in many animal models including fish. However, the maternal contribution to embryogenesis does not stop at MBT, but continues to be an essential regulator of key developmental processes. The extent to which maternal effects contribute to embryonic and larval development is hard to estimate due to the technical difficulty of interfering with maternal gene products by conventional forward and reverse genetic tools.

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The primary aim of our research was to investigate the applicability of activated sludge models (ASM) for aerobic thermophilic processes, especially autothermal thermophilic aerobic digestion (ATAD). The ASM3 model (Gujer et al., 1999) theoretically seems to be the most suitable, because storage plays an important role in a batch-feed cycle system like ATAD.

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