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Synchronic digital stereophotography and photogrammetric analyses in monitoring the flow of liquids in open channels
PublikacjaThe authors present the results of their research into photogrammetric documents based on synchronic digital images. Examples presented in the paper indicate the value of synchronic stereophotography in registering phenomena connected with liquids. Combining synchronic stereophotography with photogrammetric methods has allowed the authors to develop an application useful for monitoring the flow of a liquid in an open channel.
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Difference functional inequalities and applications.
PublikacjaThe paper deals with the difference inequalities generated by initial boundary value problems for hyperbolic nonlinear differential functional systems. We apply this result to investigate the stability of constructed difference schemes. The proof of the convergence of the difference method is based on the comparison technique, and the result for difference functional inequalities is used. Numerical examples are presented.
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ESTIMATION OF THE WILLINGNESS-TO-PAY FOR PRESERVING THE FOOTBALL ARENA IN GDANSK
PublikacjaThe European Football Championship (Euro 2012) organized in Poland became the pretext for a number of infrastructural changes. A high level of expenditure makes the Polish event the most expensive among events of this magnitude. The fact that these changes were 100% financed by public funds raises the question of whether these funds were used in a substantiated way. Therefore, the aim of this study is...
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Overall color parameter as a parameter determining the level of oxidation of olive oil
PublikacjaEdible fats are an important part of a human daily diet. They have a significant effect on the proper functioning of the human body. During frying, the oil is chemically modified and the fats consumed should have the highest oxidation stability. The subject of the study were samples of olive oil bought at local markets in Gdansk. Samples were heated at 20 °C, 60 °C, 100 °C, 140 °C and 180 °C. The aim of the study was to determine...
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A Comparative Study on Methods of Distinction Between Near- and Far-Side Defects as Techniques Used Alongside with the Magnetic Flux Leakage Testing
PublikacjaResults of the finite element analysis show that a far-side defect in a steel plate, with the depth greater by 10% of the plate thickness than a near-side defect, can produce a very similar magnetic flux leakage (MFL) signal. Due to the fact that a measurement of MFL itself can lead to misclassification of a far-side defect as a near-side one, and thus to underestimation of its depth, a comparative study of three complementary...
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Design, synthesis and biological evaluation of novel N-phosphorylated and O-phosphorylated tacrine derivatives as potential drugs against Alzheimer’s disease
PublikacjaIn this work, we designed, synthesised and biologically investigated a novel series of 14N- and O-phosphorylated tacrine derivatives as potential anti-Alzheimer’s disease agents. In the reaction of 9-chlorotacrine and corresponding diamines/aminoalkylalcohol we obtained diamino and aminoalkylhydroxy tacrine derivatives. Next, the compounds were acid to give final products 6–13 and 16–21 that were characterised by 1H, 13 C, 31P...
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Bead-on-Plate Underwater Wet Welding on S700MC Steel
PublikacjaThe participation of high strength steels in marine and offshore structures is increasing, which makes it necessary to develop recommendations for underwater repair welding works. The article presents the results of bead-on-plate welded specimens made of S700MC high strength steel in underwater wet welding conditions by covered elec- trodes. Three specimens with heat input values in the range 0.91-1.05 kJ/mm were made. The specimens...
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Fault Loop Impedance Measurement in Circuits Fed by UPS and Principle of Safety Protection
PublikacjaThis paper indicates a significant problem of uncertainty of fault loop impedance (FLI) measurement in circuits powered from uninterruptible power supply (UPS) (double-conversion AC-DC-AC). The correctly determined value of this impedance, related to the short-circuit current disconnection time and to the reference value, is one of the most important elements that determines the approval of an electrical installation and its receivers...
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Influence of Properties of Hydraulic Fluid on Pressure Peaks in Axial Piston Pumps’ Chambers
PublikacjaThe article concentrates on the research of the pressure peaks in a working chamber of an axial piston pump. The main focus of the article is the influence of fluid properties on the pressure peaks value. Experimental and analytical methods were used to determine the impact of the fluid density, viscosity, compressibility and aeration. The article describes the pressure peak generation process and explains the theoretical basis...
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Influence of Different Biofuels on the Efficiency of Gas Turbine Cycles for Prosumer and Distributed Energy Power Plants
PublikacjaThe efficiency of a gas turbine can be affected by the use of different biofuels usually with a relatively Lower Heating Value (LHV). The paper evaluates the impact of calorific value of fuel on turbine performance and analyzes the possibilities of optimizing turbine construction from the point of view of maximum efficiency for a particular fuel. The several variants of design of small power microturbines dedicated to various biofuels...
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Exploring the preferences of Polish EFL teachers towards the accents of English
PublikacjaThis language attitudes study investigates the preferences of EFL (English as a foreign language) teachers from Poland towards the accents of English they speak and teach. Despite the substantial amount of research on EFL learners, little has been done to investigate the impact of preferences of Polish teachers for different variations of English language on their...
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Selecting a transport and forwarding company for meeting a customer’s needs when organizing international road cargo transportation
PublikacjaThe object of this study is the process of planning the work of a manufacturing enterprise that needs transport and forwarding services when exporting goods to counterparties in different countries of the world. The problem being solved is predetermined by the need to devise recommendations for choosing a transport and forwarding company when serving an individual customer, based on its individual needs and conditions of cooperation. A...
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Europe, between Mandatory and Voluntary Approach to CSR: Some New Evidence from the Polish Listed Companies
PublikacjaThis paper aims to explore the relationship between corporate governance rules and application of CSR practices into operations of the top 30 companies listed on the Warsaw Stock Exchange. Since in Poland, so far, there is no obligation to follow any specific CSR standards or to make disclosures of non-financial, social and environmental information, this is still a fully voluntary approach. At the moment, only some of the companies...
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PSYCHOLOGICAL CAPITAL AND CHALLENGE APPRAISAL FOSTER THRIVING IN THE GLOBALIZED MULTICULTURAL WORKPLACE
PublikacjaThe purpose of the study was to examine the psychological resources which foster thriving in multicultural work settings of multinational corporations (MNCs) - the companies that are evident manifestation of globalization. Although globalized multicultural workplace creates specific job demands that pose unique occupational stress to individuals, some personal resources enable them to deal with these demands and to thrive. Thriving...
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Instructor Presence in Video Lectures: Preliminary Findings From an Online Experiment
PublikacjaMotivation. Despite the widespread use of video lectures in online and blended learning environments, there is still debate whether the presence of an instructor in the video helps or hinders learning. According to social agency theory, seeing the instructor makes learners believe that s/he is personally teaching them, which leads to deeper cognitive processing and, in turn, better learning outcomes. Conversely, according to cognitive...
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Conservation aspects of cast-iron platform shelters on the example of Vistula Pomerania railway stations
PublikacjaCast-iron shelters were used in the 19th century as cheaper alternatives to large platform halls. Nevertheless, they were aesthetically distinguishable from later riveted solutions. Because of their durability and continuous utility, they were not the subject of disassembly, as numerous transport infrastructure objects have been in recent decades. This article aims to indicate proper conservation practices during construction works...
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Consequences of russia’s military invasion of Ukraine for Polish-Ukrainian trade relations
PublikacjaAn accurate forecast of interstate trade volume allows for short-term and long-term planning, particularly deciding on state budget revenues, foreign exchange earnings, border arrangement, other infrastructure, migration and social policies. Hostilities are destructive so the russian military aggression against Ukraine in 2022 needs to be assessed in terms of its effects on key economic aspects of Polish-Ukrainian relations, as...
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The noise macromodel of an optocoupler including 1/(f^alfa) noise source
PublikacjaThe course of design of an optocoupler's PSpice macromodel including noise sources is described. The PSpice macromodel is proposed for the low frequency range. The PSpice model of a MOSFET transistor was applied as the noise source type 1/(f^alfa) in an optocoupler PSpice macromodel. In the enhanced macromodel the value of an exponent α can be changed in the range of 0.8 - 1.25.
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Influence of the thermal modernization of window on transmission heat losses
PublikacjaThe article presents the results of calculations of the heat transfer coefficient for the state before and after renovation for the historic windows. The aim of the analysis was to obtain the values of thermal insulation parameters demanded by the regulations, while not losing the historical value of the window. The described example of the renovation of the existing window consisted in installing an additional window panel from...
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Verification of baffle factor for straight pipe flow
PublikacjaDuring the water disinfection devices designing, it is often assumed that the baffle factor for a straight pipe reactors is equal to one. It would be possible only for the plug flow, which is a simplified model of the flow and does not appear in real situations. The paper contains an equation which enables calculation of the real value of the baffle factor for the pipe flow.
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Nonadaptive estimation of the rotor speed in an adaptive full order observer of induction machine
PublikacjaThe article proposes a new method of reproducing the angular speed of the rotor of a cage induction machine designed for speed observers based on the adaptive method. In the proposed solution, the value of the angular speed of the rotor is not determined by the classical law of adaptation using the integrator only by an algebraic relationship. Theoretical considerations were confirmed by simulation and experimental tests.
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Proposition of the steam turbine governor structure modification
PublikacjaThere is considered the steam turbine governor operation during defense and restoration of the power system. It points out weaknesses of currently used governor structures. The new controller is proposed, that takes advantages of those curently used. The new controller allows for more effective control of the turbine in emergency situations, at frequencies much different from the nominal value.
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Positive solutions to advanced fractional differential equations with nonlocal boundary conditions
PublikacjaWe study the existence of positive solutions for a class of higher order fractional differential equations with advanced arguments and boundary value problems involving Stieltjes integral conditions. The fixed point theorem due to Avery-Peterson is used to obtain sufficient conditions for the existence of multiple positive solutions. Certain of our results improve on recent work in the literature.
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Deep slot effect in the squirrel-cage induction motors with scalar (V/F) control
PublikacjaQualitative characteristics of the electrical drive considerably depend on identification accuracy of math model parameters. In particular, it is depend on detection accuracy of stator active resistance r1 that is used in calculation of flux linkages, rotary speed in sensorless control systems. Paper provides analysis of influence of stator deep slot effect to stator active resistance value
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Strong ellipticity within the Toupin–Mindlin first strain gradient elasticity theory
PublikacjaWe discuss the strong ellipticity (SE) condition within the Toupin–Mindlin first strain gradient elasticity theory. SE condition is closely related to certain material instabilities and describes mathematical properties of corresponding boundary-value problems. For isotropic solids, SE condition transforms into two inequalities in terms of five gradient-elastic moduli.
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Revitalized Mill Island in Bydgoszcz - the identity of the place created by the Brda River and its tributary named Młynowka
PublikacjaMill Island in Bydgoszcz, Poland is an example of downtown public space where a meander of the Młynówka creates the identity of the area.Before 2005, the only outstanding local feature was the fact that its south and west ends resembled the Venetian canals. The way the other parts of Mill Island were managed was inappropriate for a downtown.A comprehensive revitalization programme is returning Mill Island public space to residents,...
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Low-coherence method of hematocrit measurement
PublikacjaDuring the last thirty years low-coherence measurement methods have gained popularity because of their unique advantages. Low-coherence interferometry, low-coherence reflectometry and low-coherence optical tomography offer resolution and dynamic range of measurement at the range of classical optical techniques. Moreover, they enable measurements of the absolute value of the optical path differences, which is still an unsolved problem...
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Evaluation of Thermal Stresses in Asphalt Layers in Comparison with TSRST Test Results
PublikacjaThe paper presents the results of calculations and laboratory determination of thermal stresses at low temperatures. The modified Hills and Brien's method was used to calculate the thermal stresses in asphalt layers of pavements and the results were compared against the values obtained at a laboratory with the Thermal Stress Restrained Specimen Test (TSRST) method. The laboratory investigations were conducted using plain grade...
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Synthesis of bicoumarin thiophosphate derivatives as steroid sulfatase inhibitors
PublikacjaBased on the frameworks of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c] chromen-6-one, a series of bicoumarin thiophosphate analogs have been synthesized and biologically evaluated. Additionally, their binding modes have been modeled using docking techniques. The inhibitory properties of the synthesized compounds...
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Glosa aprobująca do wyroku Izby Karnej Sądu Najwyższego z 29 maja 2018 r. o sygn. akt II KK 99/18. A comment of approval on the verdict of 29 May 2018 issued by the Criminal Law Chamber of the Polish Supreme Court (II KK 99/18).
Publikacja"Glosowany wyrok Sądu Najwyższego dotyczy problematyki orzekania o czynach przeciwko mieniu, w stosunku do których od 9 listopada 2013 r. kryterium uznania danego czynu za przestępstwo albo za wykroczenie stanowi określony w kodeksie wykroczeń wskaźnik minimalnego wynagrodzenia za pracę. We wskazanym zakresie należy mieć na uwadze minimalne wynagrodzenie z daty orzekania w przedmiocie odpowiedzialności za taki czyn, a nie z...
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How to evaluate methods used in chemical laboratories in terms of the total chemical risk? – a ChlorTox Scale
PublikacjaReliable assessment of the health and environmental risk associated with the use of chemicals is critical to ob- jectively evaluate the greenness and whiteness of an analytical method. An objective and useful way of risk assessment should take into account all the relevant properties of used substances, their actual amounts needed for application of the method, and quantify the assessment result using a standardized unit. This...
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Influence of Surface Laser Treatment on Mechanical Properties and Residual Stresses of Titanium and its Alloys
PublikacjaSurface modification of the titanium and its alloys used in implantology with a long-pulse laser can change the surface topography, but it also leads to changes in the stress sign and magnitude in the resulting subsurface layer. The presented research was aimed at evaluating the state of stress after laser remelting with the Nd:YAG laser of pre-etched titanium alloys Ti6Al4V and Ti13Nb13Zr and pure titanium. The obtained surface...
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EMPIRICAL ASSESMENT OF THE MAIN DRIVING SYSTEM OF THE CIRCULAR SAWING MACHINE
PublikacjaThe producers of panel saws tend to improve sawing accuracy and minimise a level of vibrations, to increase their competitiveness at the market. Mechanical vibrations in the main saw driving system, which level depend on a plethora independent factors, may really affect sawing accuracy and general machine tool vibrations. The objective of the research was to explore vibrations signals of the main spindle system, and to extract...
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Information Retrieval in Wikipedia with Conceptual Directions
PublikacjaThe paper describes our algorithm used for retrieval of textual information from Wikipedia. The experiments show that the algorithm allows to improve typical evaluation measures of retrieval quality. The improvement of the retrieval results was achieved by two phase usage approach. In first the algorithm extends the set of content that has been indexed by the specified keywords and thus increases the Recall value. Then, using the...
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The influence of IT-competency dimensions on job satisfaction, knowledge sharing and performance across industries
PublikacjaPurpose – Technology makes knowledge management easier. Knowledge sharing is essential for organizational development. Job satisfaction fosters knowledge sharing. Hence, this study aims to develop an understanding of the mutual relationship between knowledge sharing and job satisfaction when both are predicted by information technology (IT)-competency dimensions such as IT-operations, IT-knowledge and IT-infrastructure in the context...
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Synthesis, thermal, structural and electrical properties of vanadium-doped lithium-manganese-borate glass and nanocomposites
PublikacjaA glassy sample with a nominal formula LiMn1−3x/2VxBO3 (where x = 0.05) was synthesised using the melt-quenching method. Material was characterised by differential thermal analysis (DTA), X-ray diffactometry (XRD) at room temperature and as a function of temperature (HT-XRD), X-ray photoelectron spectroscopy (XPS), impedance spectroscopy (IS) and scanning electron microscopy (SEM). Dependences of glass transition and crystallisation...
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Agile Requirements Prioritization in Practice: Results of an Industrial Survey
PublikacjaAgile software development stresses the importance of providing the customer with a product of a maximized business value. To achieve that, requirements prioritization is used. Agile development methods like Scrum define guidelines for prioritization, however practitioners do not necessarily have to follow them. Our goal was to investigate the industry practice related to requirements prioritization process, including its timing,...
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NON-LINE ANALYSIS OF STIFFNESS IN COMPRESSION CONDITIONS
PublikacjaThe analyzes were aimed at demonstrating the influence of parameters describing the deformation of the structure on the uncertainty of critical force, and the impact of technological imperfections on stress uncertainty in compression conditions. In a linear buckling analysis, the problem is considered only for the initial, permanent state of the stiffness matrix. In the case of demonstrating the influence of initial deformations...
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Modyfikacja cementu kostnego w celu uzyskania długotrwałej ochrony antybakteryjnej
PublikacjaNiniejsza rozprawa doktorska stanowi przewodnik po jednotematycznym cyklu publikacji, dotyczącym modyfikacji akrylowego cementu kostnego celem uzyskania długotrwałej i efektywnej ochrony antybakteryjnej. W ramach niego przeprowadzono badania eksperymentalne polegające na opracowaniu technologii wytwarzania modyfikowanego cementu kostnego oraz procedury medycznej jego stosowania. Cement kostny był modyfikowany przez zastosowanie...
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Automatic detection and correction of detuned singing system for use with query-by-humming applications
PublikacjaThe aim of the paper is to present an idea of using the automatic detection and correction of detuned singing as a subsystem in query-by-humming (QBH) applications. The common approach to searching for a requested song basing on the melody retrieved from hummed pattern usually employs the so-called Parsons code or melody contour. In such a case information about sound pitch is discarded. It was thought out that an additional module...
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Study of the effect of thermally reduced graphene oxide on the physical and mechanical properties of flexible polyurethane foams
PublikacjaFlexible polyurethane foams were obtained from a two-component system via the one-step method. The foams were modified with thermally reduced graphene oxide added in the amount equal to 0.25, 0.5 and 0.75 wt%. The morphology, static and dynamic properties, and thermal stability of modified foams were determined. The application of carbon filler resulted in the visible increase in the cell size, apparent density and rigidity of...
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Tunable emission and energy transfer of B2O3–Bi2O3–AlF3 glass system doped with Eu3+/Dy3+
PublikacjaThe structure and luminescent properties of the B2O3–Bi2O–AlF3 glass system doped with Eu3+/Dy3+ ions in different molar ratios were studied. A series of glasses were synthesized by the conventional melt quenching technique. Glass transition and crystallization temperatures were examined by Differential Thermal Analysis (DTA) measurements. The amorphous character of the prepared samples was confirmed by the X-ray diffraction (XRD)...
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Voltage Control of a Stand-Alone Multiphase Doubly Fed Induction Generator
PublikacjaThis article presents a multiphase doubly fed induction generator (MDFIG) with a dedicated and unique control algorithm in a stand-alone wind energy conversion system. The algorithm has been developed and elaborated in the case of different emergency modes. Compared with the traditional double-fed induction generator, the MDFIG has increased reliability, reduced current level per phase, and low rotor harmonic currents. The control...
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Low-frequency noise in Au-decorated graphene–Si Schottky barrier diode at selected ambient gases
PublikacjaWe report results of the current–voltage characteristics and low-frequency noise in Au nanoparticle (AuNP)-decorated graphene–Si Schottky barrier diodes. Measurements were conducted in ambient air with addition of either of two organic vapors, tetrahydrofuran [(CH2)4O; THF] and chloroform (CHCl3), as also during yellow light illumination (592nm), close to the measured particle plasmon polariton frequency of the Au nanoparticle...
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Synthesis and thermal studies of flexible polyurethane nanocomposite foams obtained using nanoclay modified with flame retardant compound
PublikacjaThis work presents thermal studies of nanocomposites based on the flexible polyurethane (PU) matrix and filled using montmorillonite organically modified with organophosphorus flame retardant compound. Flexible PU nanocomposite foams were prepared in the reaction carried out between reactive alcoholic hydroxyl and isocyanate groups with the ratio of NCO to OH groups equal to 1.05. The amount of an organoclay ranging from 3 to 9...
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Effect of modified soybeen oil amount on rheological characteriza-tion of polyurethane pre-polymers
PublikacjaPolyurethanes (Pu’s) are the polymeric materials which have got urethane groups in the structure. The properties of Pu’s depend both on the method of preparation and monomers used. Polyurethanes are produced by two methods known as one step or two step method called as “pre-polymers method”, especially for the case of segmented polyurethanes (SPU’s). These materials are thermoplastic block copolymers of the (AB)n type consisting...
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Polish experience with cold in-place recycling
PublikacjaDeep cold in-place recycling using cement and asphalt emulsion has been used for reconstruction of existing roads since the beginning of the 1990s. This paper describes the first Polish requirements for mineral-cement-emulsion mixtures. As requirements stated for the strength of the mineral-cement-emulsion mixtures were quite high, most of the mixtures were designed using high amount of cement and aggregate added for the improvement...
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A general isogeometric finite element formulation for rotation‐free shells with in‐plane bending of embedded fibers
PublikacjaThis article presents a general, nonlinear isogeometric finite element formulation for rotation-free shells with embedded fibers that captures anisotropy in stretching, shearing, twisting, and bending - both in-plane and out-of-plane. These capabilities allow for the simulation of large sheets of heterogeneous and fibrous materials either with or without matrix, such as textiles, composites, and pantographic structures. The work...
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Effect of ionic liquids on surface and photocatalytic properties of selected semiconducttors
PublikacjaThe main aim of this doctoral dissertation was to explain the role of ionic liquids in shaping the morphology of selected semiconductors, thereby enhancing the photocatalytic activity. In order to achieve this goal, the following research steps were taken: (i) developing synthesis methods of selected semiconductors, with particular emphasis on the electrochemical oxidation method; (ii) understanding the influence of the selected...
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Impact of selected drugs and their binary mixtures on the germination of Sorghum bicolor (sorgo) seeds
PublikacjaThe aim of this study was to assess the toxicological potential of binary drug mixtures and individual drugs under different pH conditions with different inorganic ion additions on the germination of Sorghum bicolor (sorgo) seeds. To assess whether the given drug mixtures were more phytotoxic than the individual compounds, concentration addition (CA) and independent action (IA) approaches were applied to estimate the predicted...