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Search results for: moderate%20temperature
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Thermoelectric properties of bismuth-antimony-telluride alloys obtained by reduction of oxide reagents
PublicationThe BieSbeTe alloys with different Bi/Sb/Te ratio were fabricated by an innovative method. For that purpose the oxide reagents were melted at high temperature, then quenched to form pellets, milled to a powder and finally reduced in hydrogen at various temperatures. Complex structures consisting of connected thin layers forming a continuous path between nano- and micrometer size grains have been obtained. The electrical conductivity,...
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Three phase transient model of wet coal pyrolysis
PublicationA one-dimensional transient mathematical model was developed to describe the thermal and flow phenomena during coal pyrolysis in a coke oven. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. It was successfully validated with industrial-scale measurements of temperature change in the middle-plane of the coke oven chamber. The evolution of temperature and pressure, distributions...
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Highly stable CsFAPbIBr perovskite solar cells with dominant bulk recombination at real operating temperatures
PublicationMixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from −20 °C up to 50 °C) and the time evolution of the device efficiency has been assessed using different degradation protocols (indoors and outdoors). The completely planar p–i–n structure is ITO/CuNiOx/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current–voltage characteristics barely show hysteresis, at any temperature. Open circuit...
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Beeswax And Palmitic Acid Utilization With Heat Pipes For Electronics Cooling
PublicationThis paper presents an experimental study of heat pipes supported by phase change materials (PCMs) coated at their adiabatic sections in application for electronics cooling. The PCMs investigated in this research were palmitic acid and beeswax, the latter being considered as a more cost-effective alternative. The study focused on three powers: 20W, 25W, and 30W. The experimental results revealed that the incorporation of palmitic...
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Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test
PublicationThermal stresses are leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when the temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature...
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Mechanical Strength of MV Ship-switchgear During Fault Arc
PublicationIn the paper the analysis of pressure stressed in enclosure during fault arc inside switchgear is pre-sented as well. There is introduced the method based on determining stresses which are sum of tensile stresses (membrane) and deflection stresses. For tensile stresses nalysis the energy method, for unrestrainedly supported rectangular plate, was used. In the further part of the paper, the calculations and measurements results...
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Molecular Dynamics simulations of thermal conductivity of penta-graphene
PublicationThe thermal conductivity of penta-graphene (PG), a new two dimensional carbon allotrope and its dependence on temperature, strain, and direction are studied in this paper. The thermal conductivity of PG is investigated using a non-equilibrium molecular dynamics simulation (NEMD) with the Two Region Method by applying the optimized Tersoff interatomic potential. Our study shows that the thermal conductivity of PG (determined for...
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Woda jako źródło, nośnik, akumulator oraz transformator energii
PublicationWoda, posiadająca specyficzne właściwości fizyczne, może być jednocześnie stosowana do wielu celów (np. moderator, chłodziwo i czynnik roboczy). Każda dziedzina nauki, techniki i przemysłu stosuje wodę w inny sposób, wykorzystując różne właściwości wody. Powszechność wody w życiu codziennym powoduje, że często człowiek nie zdaje sobie sprawy z wyjątkowych, a czasem bardzo zaawansowanych zastosowań "zwykłej" wody. Niniejszy rozdział...
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Warunki hydrogeochemiczne i podatność na zanieczyszczenie wód podziemnych w zlewni górnej Raduni
PublicationThe paper presents results of long-term studies in the Kashubian Lake district that have been completed with data gathered over the last five years. The purpose of this research was to assess a temporal variability of groundwater chemical composition and to analyze risk of pollutant migration to subsurface water. Investigation indicates local, however, significant anthropogenic influence on a shallow aquifers.The assessment of...
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SORPTION OF SELECTED CHLORINATED SOLVENTS ON PLANT DEBRIS COLLECTED IN A CITY PARK
PublicationDebris from deciduous trees in the form of park green waste was investigated as a potential biosorbent for the removal of chlorinated solvents from water. The sorption properties of beech leaves and cupules, oak leaves and acorns, birch leaves and lime leaves (all tree species common for a moderate climate) in a non-modified form were investigated with regard to the removal of perchloroethylene, 1,1,2-trichloroethane and 1,1,1,2-tetrachlorothane....
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Exploring COVID-19 Conspiracy Theories: Education, Religiosity, Trust in Scientists, and Political Orientation in 26 European countries
PublicationThe COVID-19 virus disseminated globally at an accelerated pace, culminating in a worldwide pandemic; it engendered a proliferation of spurious information and a plethora of misinformation and conspiracy theories (CTs). While many factors contributing to the propensity for embracing conspiracy ideation have been delineated, the foremost determinant influencing individuals’ proclivity towards CT endorsement appears to be their...
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Mercury concentration in the sediments as a function of changing climate in coastal zone of Southern Baltic Sea – preliminary results
PublicationMercury, despite of its many uses in industry, is also highly toxic. It is highly neurotoxic, and because of the ability of mercury to penetrate placental barrier, in some countries ban on predatory fish consumption (the main route of mercury into human organism) by pregnant women was introduced. There are very little publications describing the consequences of weather anomalies on contaminants cycles. No research was published...
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Fabrication of Gold and Silver Nanoparticles Supported on Zinc Imidazolate Metal–Organic Frameworks as Active Catalysts for Hydrogen Release from Ammonia Borane
PublicationWell-dispersed Au and Ag nanoparticles (NPs) have been immobilized on a zinc imidazolate metal−organic framework, Zn(mim), using the “one-pot” method and tested as catalysts in ammonia borane hydrolysis. The AuNPs@Zn(mim) and AgNPs@Zn(mim) materials were characterized by FTIR, XRD, ICP-OES, TGA, BET, SEM, and TEM. The AgNPs@Zn(mim) catalyst showed a high yield (98.5%) and high hydrogen generation rate (3352.71 mL min−1 gAg−1) in...
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Can Inflation Forecast and Monetary Policy Path be Really Useful? The Case of the Czech Republic
PublicationProducing and revealing inflation forecast is belie ved to be the best way of implementing a forward-looking monetary policy. The article focuses on inflation forecast targeting (IFT) at the Czech National Bank (CNB) in terms of its efficiency in shaping consumers’ inflation expectations. The goal of the study is to verify the accuracy of the inflation forecasts, and their influence on inflation...
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Paenibacillus alvei MP1 as a Producer of the Proteinaceous Compound with Activity against Important Human Pathogens, Including Staphylococcus aureus and Listeria monocytogenes
PublicationAn emerging need for new classes of antibiotics is, on the one hand, evident as antimicrobial resistance continues to rise. On the other hand, the awareness of the pros and cons of chemically synthesized compounds’ extensive use leads to a search for new metabolites in already known reservoirs. Previous research showed that Paenibacillus strain (P. alvei MP1) recovered from a buckwheat honey sample presented a wide spectrum of...
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Performance-driven yield optimization of high-frequency structures by kriging surrogates
PublicationUncertainty quantification is an important aspect of engineering design, as manufacturing toler-ances may affect the characteristics of the structure. Therefore, quantification of these effects is in-dispensable for adequate assessment of the design quality. Toward this end, statistical analysis is performed, for reliability reasons, using full-wave electromagnetic (EM) simulations. Still, the computational expenditures associated...
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The Quantum Efficiency Roll-Off Effect in Near-Infrared Organic Electroluminescent Devices with Iridium Complexes Emitters
PublicationThe electroluminescence quantum efficiency roll-off in iridium(III)-based complexes, namely Ir(iqbt)2(dpm) and Ir(iqbt)3(iqbt=1 (benzo[b]thiophen-2-yl)-isoquinolinate, dpm=2,2,6,6-tetramethyl-3,5-heptanedionate) utilized as near-infrared emitters in organic light emitting diodes with remarkable external quantum efficiencies, up to circa 3%, 1.5% and 1%, are measured and analyzed. With a 5–6 weight % of emitters embedded...
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Probiotic potential of Bacillus Isolates from Polish Bee Pollen and Bee Bread
PublicationThe main goal of this study was the evaluation of the probiotic potential of 10 Bacillus spp. strains isolated from 5 bee bread and 3 bee pollen samples. The antagonistic interaction with Staphylococcus aureus and Escherichia coli was a primary criterion for the preliminary selection of the isolates. Three out of ten strains—PY2.3 (isolated from pollen), BP20.15 and BB10.1 (both isolated from bee bread)—were found to be possible...
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Novel monovalent and multivalent recombinant proteins of Borrelia burgdorferi sensu lato with potential diagnostic value – construction and biotechnological production
PublicationThe diverse antigenic structure of Borrelia burgdorferi sensu lato (s.l.) and the low degree of protein sequence conservation between genospecies causes many limitations in serodiagnosis of Lyme disease (LD). Using expression systems based on Escherichia coli, five monovalent B. burgdorferi s.l. recombinant proteins were produced. i.e., BB0108, BB0126, BB0298, BB0323, BB0689 (each in three variants derived from Borrelia afzelii,...
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Targeting yeast topoisomerase II by imidazo and triazoloacridinone derivatives resulting in their antifungal activity
PublicationFungal pathogens are considered as serious factors for deadly diseases and are a case of medical concern. Invasive fungal infections also complicate the clinical course of COVID-19, leading to a significant increase in mortality. Furthermore, fungal strains' multidrug resistance has increased the demand for antifungals with a different mechanism of action. The present study aimed to identify antifungal compounds targeting yeast...
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Isothermal Calorimetry and Compressive Strength Tests of Mortar Specimens for Determination of Apparent Activation Energy
PublicationThe hydration process of cementitious materials involves a thermally activated reaction that depends on the composition of the mixture and the curing temperature. The main parameter affecting the temperature variation of cast-in-place concrete is the apparent activation energy, which can be used for the efficient prediction of the temperature evolution and maturity index of hardening concrete. This paper discusses two methods to...
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Fabrication and Study of BiNbO4 Ceramics
PublicationAim of the present research was to fabricate and study crystalline structure as well as dielectric properties of BiNbO4 ceramics. In the present study BiNbO4 ceramics was fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, and Nb2O5. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements proved conservation of the chemical...
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Empirical Relationship Describing Total Convective and Radiative Heat Loss in Buildings
PublicationOn the basis of theoretical considerations of convective-radiative heat transfer, a relationship was developed enabling the total convective and radiative heat flux QC+R emitted from any object at tw and its surroundings at t∞ to be calculated from known values of the surface temperature of such an object, i.e., the known temperature difference Δt=tw - t∞ and average air temperature Tav. This relationship is applied to thermal...
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Exergy analysis of a negative CO2 emission gas power plant based on water oxy-combustion of syngas from sewage sludge gasification and CCS
PublicationA power cycle with water-injected oxy-combustion (water cycle) is investigated by exergy analysis. It is fueled with syngas (aka. producer gas) from gasification of sewage sludge. The cycle is equipped with a spray-ejector condenser (SEC). CO2 is separated and compressed for transportation and storage. The net delivered electric power is 31% of the fuel exergy. The task efficiency is 39% when the flue gas bleed to gasification...
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Wykorzystanie słabych sygnałów, foresightu i ciągu zarządzania strategicznego w konfiguracji biznesu przyszłości
PublicationBurzliwość współczesnego otoczenia wyostrza zagadnienie przystosowania prowadzonej działalności gospodarczej do funkcjonowania w przyszłości. Do osiągnięcia sukcesu w biznesie przyszłości przyczynić się może wykorzystanie dostępnej już obecnie wiedzy. Na szczególną uwagę zasługuje teoria słabych sygnałów, metoda foresight oraz ciąg zarządzania strategicznego, które w połączeniu umożliwiają wypracowanie stanowiska w sprawie kształtu...
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Five-phase squirrel-cage motor. Construction and drive properties
PublicationThis paper presents the simulation and experimental results of a five-phase squirrel-cage induction motor. The new machine has been designed to operate in a drive system with third harmonic rotor flux injection in order to improve the motor torque utilization. The motor structure, the mathematical model as well as the laboratory prototype have been described. The motor speed-torque characteristics and transients are elaborated...
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A method of earth fault loop impedance measurement without unwanted tripping of RCDs
PublicationIn low-voltage networks, earth fault loop impedance (EFLI) measurement is the basis for assessing the effectiveness of automatic disconnection of supply. Such a measurement is performed during initial and periodical verification, especially in a TN low-voltage network. Nowadays, due to widespread application of residual current devices (RCDs), such test is difficult in many circuits because RCDs operate during the test. In this...
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Augmenting digital documents with negotiation capability
PublicationActive digital documents are not only capable of performing various operations using their internal functionality and external services, accessible in the environment in which they operate, but can also migrate on their own over a network of mobile devices that provide dynamically changing execution contexts. They may imply conflicts between preferences of the active document and the device the former wishes to execute on. In the...
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Data Partitioning and Task Management in the Clustered Server Layer of the Volunteer-based Computation System
PublicationWhile the typical volunteer-based distributed computing system focus on the computing performance, the Comcute system was designed especially to keep alive in the emergency situations. This means that designers had to take into account not only performance, but the safety of calculations as well. Quadruple-layered architecture was proposed to separate the untrusted components from the core of the system. The main layer (W) consists...
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Analysis of soundscape recordings in close proximity to the road in changeable wather conditions
PublicationThe acoustic vehicle sensing is the least invasive type of traffic detection. Also, acoustic-based vehicle detection technology is insensitive to precipitation and can operate in low light level. Therefore, this kind of method may be used for automatic detection of the vehicle passage events. It can also be employed for measurements of a vehicle speed and the vehicle assignment to the particular category. In this paper the results...
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A New, Reconfigurable Circuit Offering Functionality of AND and OR Logic Gates for Use in Algorithms Implemented in Hardware
PublicationThe paper presents a programmable (using a 1-bit signal) digital gate that can operate in one of two OR or AND modes. A circuit of this type can also be implemented using conventional logic gates. However, in the case of the proposed circuit, compared to conventional solutions, the advantage is a much smaller number of transistors necessary for its implementation. Circuit is also much faster than its conventional counterpart. The...
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Effect of polymer fibres reinforcement on selected properties of asphalt mixtures
PublicationThe paper presents selected results of the research program concerning fibre reinforced asphalt concrete. Aramid-polyalphaolefin fibres was used in this study. Selected properties responsible for low temperature cracking and resistance to permanent deformation are presented in this paper. Low temperature cracking susceptibility was evaluated with the results obtained from bending test of rectangular beams with constant rate of...
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Accurate electrothermal modelling of high frequency DC-DC converters with discrete IGBTs in PLECS software
PublicationIn the paper, a novel, improved method of the IGBT junction temperature computations in the PLECS simulation software is presented. The developed method aims at accuracy of the junction temperature computations in PLECS by utilising a more sophisticated model of transistor losses, and by taking into account variability of transistor thermal resistance as a function of its temperature. A detailed description of the proposed method,...
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Thermally activated persulfate-based Advanced Oxidation Processes — recent progress and challenges in mineralization of persistent organic chemicals: a review
PublicationThermally activated persulfate (TAP) finds application in Advanced Oxidation Processes for the removal of pollutants from contaminated water and soil. This paper reviewed the various cases of TAP in the environmental remediation. The pollutants such as individual pharmaceuticals, biocides, cyclic organic compounds, and dyes are considered in this review. It is interesting to note that most of the organic compounds undergo complete...
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RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
PublicationStarting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of increase of resistance of cold oil flow in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump...
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Conditions for increasing the recognition of degradation in thermal-flow diagnostics, taking into account environmental legal aspects
PublicationThe ever-increasing demand for electricity and the need for conventional sources to cooperate with renewable ones generates the need to increase the efficiency and safety of the generation sources. Therefore, it is necessary to find a way to operate existing facilities more efficiently with full detection of emerging faults. These are the requirements of Polish, European and International law, which demands that energy facilities...
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Ground tire rubber thermo-mechanically devulcanized in the presence of waste engine oil as asphalt modifier
PublicationCross-linked elastomers network is main limitation for industrial usage of ground tire rubber (GTR) as asphalts’ and road pavements modifier. GTR was thermo-mechanically devulcanized via extrusion in the presence of waste engine oil (WEO) at temperature ranges from 150 to 280 °C. Combined impact of WEO content and extruder barrel temperature on the change of cross-linked structure of degraded GTR (DTGR) was investigated through...
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Tailoring structural properties of lanthanum orthoniobates through an isovalent substitution on the Nb-site
PublicationTetragonal polymorph of lanthanum orthoniobate can be stabilized to room temperature by the substitution of Nb with an isovalent element. LaNb1-xAsxO4 (0 < x ≤ 0.3), where As is an element stabilizing tetragonal structure, were successfully synthesized with combined co-precipitation and solid-state reaction method. The phase transition temperature, above which the material has tetragonal structure, decreases linearly with increasing...
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Thermal and technological aspects of double face grinding of Al2O3 ceramic materials
PublicationDouble face grinding with planetary kinematics is a process to manufacture workpieces with plan parallel functional surfaces, such as bearing rings or sealing shims. In order to increase the economic efficiency of this process, it has to be advanced permanently. The temperature in the contact zone of most grinding processes has a huge influence on the process efficiency and the workpiece qualities. In contrast to most grinding...
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Thermal and technological aspects of double face grinding of C45 carbon steel
PublicationIn grinding, the contact zone temperature is a decisive factor influencing the achievable surface quality and the grinding tool wear. In contrast to other grinding processes, only few information regarding double face grinding with planetary kinematics when processing steel is known up to date. Since the successive substitution of in-dustrial double-sided lapping processes by double-sided grinding, it has become necessary to the...
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Graphene field-effect transistor application for flow sensing
PublicationMicroflow sensors offer great potential for applications in microfluidics and lab-on-a-chip systems. However, thermal-based sensors, which are commonly used in modern flow sensing technology, are mainly made of materials with positive temperature coefficients (PTC) and suffer from a self-heating effect and slow response time. Therefore, the design of novel devices and careful selection of materials are required to improve the overall...
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Concrete Compressive Strength Under Changing Environmental Conditions During Placement Processes
PublicationThe technological process of concrete production consists of several parts, including concrete mix design, concrete mix production, transportation of fresh concrete mix to a construction site, placement in concrete framework, and curing. Proper execution of these steps provides good quality concrete. Some factors can disturb the technological process, mainly temperature and excessive precipitation. Changing daily temperature and...
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Badania mieszanek mineralno-asfaltowych w niskiej temperaturze
PublicationW artykule przedstawiono metody badań w niskiej temperaturze betonu asfaltowego przeznaczonego do warstwy ścieralnej. Przedstawione zostały wyniki badań dla 4 różnych metod badawczych: zginania, pełzania, pośredniego rozciągania oraz rozciągania termicznego przy ograniczonym odkształceniu (test TSRST). Próbki betonu asfaltowego były przygotowywane w laboratorium z wykorzystaniem 3 rodzajów asfaltów: asfaltu zwykłego, asfaltu modyfikowanego...
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Psychological capital and happiness at work: The mediating role of employee thriving in multinational corporations
PublicationWorking in multicultural work environments of multinational corporations (MNCs) creates challenges whose expected impact on happiness is equivocal. In the following paper, we examine the relationship between psychological capital and happiness at work in the specific MNCs’ context. We assume that thriving (eudemonic well-being) at work fosters individuals’ development and enhances their happiness composed of both the affective...
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation...
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Fatigue and Professional Burnout in Police Officers and Firefighters
PublicationExcessive demands, work overload and the working time arrangements are an important cause of burnout and fatigue in employees. Specific working time arrangements are characteristic of the internal security services, such as police officers and firefighters. This applies to both the ordering of day and night shifts and the length of shifts. Depletion of personal resources is a common component for acute fatigue and burnout. However,...
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Expression of a GDSL esterase from Pseudomonas sp. S9 in Pichiapastoris
PublicationCold active lipolytic enzymes are promising to replace the conventional enzymes processes of biotechnological industries. One of the most important feature of the cold-active lipases and esterases is that they offer economic benefits through energy saving. In general, they exhibit high activity at low temperatures and low thermostability at moderate temperatures. Lipolytic enzyme EstS9 was isolated from Pseudomonas sp. S9. A multiple...
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Antifungal Activity of Capridine β as a Consequence of Its Biotransformation into Metabolite Affecting Yeast Topoisomerase II Activity
PublicationIn the last few years,increasing importance is attached to problems caused by fungal pathogens. Current methods of preventing fungal infections remain unsatisfactory. There are several antifungal compounds whichare highly effective in some cases, however, they have limitations in usage: Nephrotoxicity and other adverse effects. In addition, the frequent use of available fungistatic drugs promotes drug resistance....
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Structural evaluation of percolating, self-healing polyurethane–polycaprolactone blends doped with metallic, ferromagnetic, and modified graphene fillers
PublicationComposites with differently shaped micro- and nanofillers show various, unique thermal, and physicochemical properties when mixed with carefully chosen polymer matrix. Selected composition holds strategic value in achieving desired properties that is biodegradability, thermoelectric conductivity, and shape memory for organic coating. The main aim of this work is to briefly examine structural changes after reaching percolation threshold...
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Nanosilver-loaded PMMA bone cement doped with different bioactive glasses – evaluation of cytocompatibility, antibacterial activity, and mechanical properties
PublicationNanosilver-loaded PMMA bone cement (BC-AgNp) is a novel cement developed as a replacement for conventional cements. Despite favorable properties and antibacterial activity, BC-AgNp still lacks biodegradability and bioactivity. Hence, we investigated the doping with bioactive glasses (BGs) to create a new bioactive BC characterized by time-varying porosity and gradual release of nanosilver. The BC Cemex was used as the base material...