1,427 results match your criteria: "Technical University of Ostrava[Affiliation]"

Novel continuous in situ measurement of photocatalyst efficiency in liquid dispersions by laser absorption method.

Sci Rep

December 2024

Centre for Advanced Innovation Technologies, Faculty of Materials Science and Technology, VSB - Technical University of Ostrava, 17. listopadu 2172/15, 708 00, Ostrava- Poruba, Czech Republic.

Article Synopsis
  • This work introduces a new method and reactor design for assessing photocatalytic activity that enables ongoing monitoring of pollutant levels in liquid dispersions with photocatalysts.
  • The traditional Beer-Lambert law can't be directly applied here due to issues with light scattering from the photocatalyst, so a modified absorption law has been developed to account for both absorption and scattering effects.
  • The innovative method shows a high level of accuracy, with an average deviation of just 1.04% over 500 measurements, and is positioned as a quicker and more reliable alternative to existing photocatalytic measurement techniques.
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This abstract presents a dataset for the detection of fault types in XLPE-covered conductors utilized in 22 kV medium voltage power distribution systems. We employed an antenna-based approach for detecting partial discharges. The dataset encompasses 12 distinct fault categories, ranging from ground phase faults to inter-phase faults, and no-fault case with steel or covered conductor as fault.

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Electrochemical Drilling (ECD) is an unconventional method aimed at creating holes in metallic workpieces characterized by high hardness and complex structures. This study analyzes the influence of process variables, including machining voltage, electrolyte concentration, electrode rotational speed, electrolyte flushing pressure, and workpiece material, on the novel hole performance index (HPI) in electrical discharge machining (ECD). The HPI was identified as a suitable metric for simultaneously evaluating hole geometry and drilling time across various machining parameters and workpiece materials.

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The stochastic rupture risk assessment of an abdominal aortic aneurysm (AAA) critically depends on sufficient data set size that would allow for the proper distribution estimate. However, in most published cases, the data sets comprise no more than 100 samples, which is deemed insufficient to describe the tails of AAA wall thickness distribution correctly. In this study, we propose a stochastic Bayesian model to merge thickness data from various groups.

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The imbalance between generated power and load demand often causes unwanted fluctuations in the frequency and tie-line power changes within a power system. To address this issue, a control process known as load frequency control (LFC) is essential. This study aims to optimize the parameters of the LFC controller for a two-area power system that includes a reheat thermal generator and a photovoltaic (PV) power plant.

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Effects of proline substitution/inclusion on the nanostructure of a self-assembling β-sheet-forming peptide.

RSC Adv

November 2024

Division of Pharmacy and Optometry, Manchester Institute of Biotechnology, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester UK

Self-assembling peptides remain persistently interesting objects for building nanostructures and further assemble into macroscopic structures, hydrogels, at sufficiently high concentrations. The modulation of self-assembling β-sheet-forming peptide sequences, with a selection from the full library of amino acids, offers unique possibility for rational tuning of the resulting nanostructured morphology and topology of the formed hydrogel networks. In the present work, we explored how a known β-sheet-disassembling amino acid, proline (P), affects the self-assembly and gelation properties of amphipathic peptides.

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Purpose: High-dose intravenous glucocorticoids are the standard first-line treatment in active, moderate to severe and severe thyroid eye disease (TED). We evaluate the usefulness of clinical activity score (CAS) and thyroid-stimulating immunoglobulin (TSI) as predictors and/or post-treatment markers of corticoresistance in patients with TED and the effect of rituximab in second-line treatment.

Methods: We enrolled 236 patients with an active TED into this retrospective single-tertiary-center cohort study.

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The effect of a varying pyridine ligand on the anticancer activity of Diiron(I) bis-cyclopentadienyl complexes.

Chem Biol Interact

January 2025

University of Pisa, Department of Chemistry and Industrial Chemistry, Via Giuseppe Moruzzi 13, I-56124, Pisa, Italy. Electronic address:

The new diiron complexes [FeCp(CO)(L)(μ-CO){μ-CN(Me)(Cy)}]CFSO (L = pyridine, 3a; 4-aminopyridine, 3b; 4-dimethylaminopyridine, 3c; 4-trifluoromethylpyridine, 3d; nicotinic acid, 4; Cp = η-CH, Cy = CH = cyclohexyl) were synthesized in moderate to high yields using two distinct synthetic routes from the precursors 1 (L = CO, for 4) and 2 (L = NCMe, for 3a-d), respectively. All products were characterized by IR and multinuclear NMR spectroscopy, and the structures of 3b and 3d were ascertained by X-ray diffraction studies. The behavior of the complexes in aqueous solutions (solubility, Log P, stability) was assessed using NMR and UV-Vis methods.

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Cellulose acetate (CA) mixed-matrix membranes incorporating polyvinylpyrrolidone (PVP), bentonite (B or Ben), graphene oxide (GO), and titanium dioxide (TiO) were prepared by the phase inversion separation technique for oil/water separation. An investigation was performed where the mixed-matrix membrane was tested for the separation performance of hydrophilic and hydrophobic surface properties. An ultrafiltration experiment at the laboratory scale was used to test dead-end ultrafiltration models developed for the treatment performances of oily wastewater under dynamic full-scale operating conditions.

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Development of a Mathematical Model of the Self-Shielded Flux-Cored Arc Surfacing Process for the Determination of Deposition Rate.

Materials (Basel)

November 2024

Department of Mechanical Technology, Faculty of Mechanical Engineering, VSB-Ostrava Technical University of Ostrava, 17. listopadu 2172/15, 708 00 Ostrava-Poruba, Czech Republic.

The article presents a method of developing a mathematical model of the arc surfacing process performed using the self-shielded flux-cored filler metal wire with the chromium cast iron (Fe15) weld deposit. A three-level design (static, determined, and complete) was used to determine the function of the test object, thus enabling the simulation of deposition rate in relation to wire feed speed and electrode extension. The deposition rate for the specified set of surfacing parameters amounted to between 4.

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Wire Electrical Discharge Machining (WEDM) technology represents an unconventional but vital manufacturing technology in many different industrial branches. The automotive industry and its many significant requirements bring the need to manufacture inserts and mould segments for plastic injections from Albromet W130 material, with a required roughness, Ra, from 4.5 to 5 µm so that subsequent profile etching can be eliminated.

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This study explores the Ivancevic Option Pricing Model, a nonlinear wave-based alternative to the Black-Scholes model, using adaptive nonlinear Schrödingerr equations to describe the option-pricing wave function influenced by stock price and time. Our focus is on a comprehensive analysis of this equation from multiple perspectives, including the study of soliton dynamics, chaotic patterns, wave structures, Poincaré maps, bifurcation diagrams, multistability, Lyapunov exponents, and an in-depth evaluation of the model's sensitivity. To begin, a wave transformation is applied to convert the partial differential equation into an ordinary differential equation, from which soliton solutions are derived using the [Formula: see text] method.

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A paradigm shift in the detection of bloodborne pathogens: conventional approaches to recent detection techniques.

EXCLI J

October 2024

Center for Global Health Research, Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, India.

Article Synopsis
  • Bloodborne pathogens (BBPs) are a serious global health threat affecting both humans and animals, with notable risks for healthcare workers who face potential exposure.
  • The paper critiques traditional detection methods like PCR and ELISA, pushing for new detection technologies enhanced by advances in sensor tech.
  • It aims to educate on bloodborne infections, detailing their transmission patterns and emphasizing the need for improved management and detection strategies.
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Heavy metals: toxicity and human health effects.

Arch Toxicol

November 2024

Faculty of Chemical and Food Technology, Slovak University of Technology, 812 37, Bratislava, Slovakia.

Heavy metals are naturally occurring components of the Earth's crust and persistent environmental pollutants. Human exposure to heavy metals occurs via various pathways, including inhalation of air/dust particles, ingesting contaminated water or soil, or through the food chain. Their bioaccumulation may lead to diverse toxic effects affecting different body tissues and organ systems.

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A wind turbine system (WTS) is a highly coupled and nonlinear system where the output power depends upon highly uncertain wind speed. Therefore, the quality of produced power becomes a challenging problem for researchers. Direct Vector Control (DVC) is a powerful and widely utilized power control strategy to deal with winds that vary rapidly and randomly.

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Very low carbohydrate high fat (VLCHF) diet and high-intensity interval training (HIIT) are widely utilized for weight reduction and cardiorespiratory fitness improvement, respectively. To assess the acceptability of these approaches, it is essential to examine mental health-related indicators. This secondary analysis of a randomized controlled trial investigated the isolated and synergistic effects of VLCHF and HIIT on mental health-related indicators in individuals with excessive weight or obesity.

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Aerospace and marine industries are constantly in search of materials that can provide good strength and durability while also being lightweight. Aluminium composites with adequate reinforcements have been proven to be effective in achieving incredible mechanical properties while also maintaining a good strength to weight ratio. Numerous studies have been done to study the various possibilities of matrix reinforcement combinations in aluminium composites.

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Discovery of Lipoxygenase-Like Materials for Inducing Ferroptosis.

ACS Nano

November 2024

State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, Jiangsu 215123, China.

Recent research has highlighted the pivotal role of lipoxygenases in modulating ferroptosis and immune responses by catalyzing the generation of lipid peroxides. However, the limitations associated with protein enzymes, such as poor stability, low bioavailability, and high production costs, have motivated researchers to explore biomimetic materials with lipoxygenase-like activity. Here, we report the discovery of lipoxygenase-like two-dimensional (2D) MoSnanosheets capable of catalyzing lipid peroxidation and inducing ferroptosis.

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Highlighting the essential role of chitosan (CS), known for its biocompatibility, biodegradability, and ability to promote cell adhesion and proliferation, this study explores its utility in modulating the biomimetic mineralization of calcium phosphate (CaP). This approach holds promise for developing biomaterials suitable for bone regeneration. However, the interactions between the CS surface and in situ precipitated CaP still require further exploration.

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Magnetically Propelled Microrobots toward Photosynthesis of Green Ammonia from Nitrates.

Small

November 2024

Advanced Nanorobots & Multiscale Robotics Laboratory, Faculty of Electrical Engineering and Computer Science, VSB - Technical University of Ostrava, 17. listopadu 2172/15, Ostrava, 708 00, Czech Republic.

Ammonia (NH₃) production is a critical industrial process, as ammonia is a key component in fertilizers, essential for global agriculture and food production. However, the current method of synthesizing ammonia, the Haber-Bosch process, is highly energy-intensive, and relies on fossil fuels, contributing substantially to greenhouse gas emissions. Moreover, the centralized nature of the Haber-Bosch process limits its accessibility in remote or resource-limited areas.

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In recent years, plastic and metal 3D printing has experienced massive development in the professional and hobby spheres, especially for rapid prototyping, reverse engineering, maintenance and quick repairs. However, this technology is limited by a number of factors, with the most common being the cost and availability of the technology but also the lack of information on material properties. This study focuses on investigating the material properties of PLA, PETG, HIPS, PA, ABS and ASA in order to elucidate their behavior in terms of wear and thermal resistance.

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Previously studied complexes with protonic and hydridic hydrogen bonds exhibit significant similarities. The present study provides a detailed investigation of the structure, stabilization, electronic properties, and spectral characteristics of protonic and hydridic hydrogen bonds using low-temperature infrared (IR) spectroscopy and computational methods. Complexes of pentafluorobenzene with ammonia (C₆F₅H⋯NH₃) and triethylgermane with trifluoroiodomethane (Et₃GeH⋯ICF₃) were analyzed using both experimental and computational tools.

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2D Nitrogen-Doped Graphene Materials for Noble Gas Separation.

Small

November 2024

Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Šlechtitelů 27, Olomouc, 783 71, Czech Republic.

Noble gases, notably xenon, play a pivotal role in diverse high-tech applications. However, manufacturing xenon is an inherently challenging task, due to its unique properties and trace abundance in the Earth's atmosphere. Consequently, there is a pressing need for the development of efficient methods for the separation of noble gases.

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