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Design and experimental verification of multi-layer waveguide using pin/hole structure
PublikacjaThis study presents a novel technique for minimizing RF leakage in metallic hollow waveguides fabricated using the multilayer split-block method. By integrating a pin/hole wall into the split-block multilayers, a substantial reduction of RF leakage can be achieved while reducing the circuit size and mitigating the performance variations. To validate the proposed approach, a slot antenna fed by single ridge waveguide has been prototyped...
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Aqueous Molybdate Provides Effective Corrosion Inhibition of WE43 Magnesium Alloy in Sodium Chloride Solutions
PublikacjaCorrosion and corrosion inhibition of WE43 magnesium alloy were investigated in NaCl solutions containing different amounts of sodium molybdate. Electrochemical, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. Electrochemical data showed that Na2MoO4 inhibitor provides reliable inhibition at concentrations at and above 100 mM. Raman and XPS spectroscopy demonstrated...
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Noise effect on parameters of quiet sonar with code modulation
PublikacjaEarlier publications of the paper authors have shown that the use of code keying mixed with the CW FM sound signal allows the significant reduction in the distance measurement error, compared to classic silent CW FM sonar. In addition to the code modulation parameters, the magnitude of this error is influenced by the received input acoustic noise. The article shows the dependence of the input signal-to-noise ratio and the sound...
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ANALIZA WPŁYWU NIEJEDNOCZESNOŚCI ZAMYKANIA BIEGUNÓW ŁĄCZNIKA NA PRĄDY ZAŁĄCZENIOWE TRANSFORMATORA W STANIE JAŁOWYM
PublikacjaW artykule przedstawiono wyniki obliczeń symulacyjnych prądów załączeniowych transformatora dla różnych sekwencji zamykania biegunów łącznika. Sekwencje różniły się kolejnością łączenia faz oraz czasami opóźnienia w zamykaniu biegunów. Rozważono także kilka wariantów stanu namagnesowania szczątkowego rdzenia. Na podstawie analizy wyników stwierdzono, że przy jednoczesnym zamykaniu biegunów łącznika, właściwy dobór chwili załączenia...
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Wpływ liczby mieszkańców na obliczenia ilości ścieków w projektowaniu kanalizacji sanitarnej
PublikacjaZmiana sposobu rozliczania zużycia wody, promocja wodooszczędnych technologii oraz uszczelnienie kanałów wyraźnie wpłynęły na ilość odprowadzanych do kanalizacji ścieków. Obecnie stwierdzić można, że opracowania z lat 70-tych XX wieku podają zawyżone wskaźniki odpływu ścieków, skutkiem czego są problemy eksploatacyjne. Bez wątpienia, prawidłowe zaprojektowanie kanalizacji sanitarnej to zadanie trudne, wymagające między innymi prawidłowego...
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On the Possibility of the Amphotericin B-Sterol Complex Formation in Cholesterol- and Ergosterol-Containing Lipid Bilayers: A Molecular Dynamics Study
PublikacjaAmphotericin B (AmB) is a well-known membrane-active antibiotic that has been used to treat systemicfungal infections for more than 45 years. Therapeutic application of AmB is based on the fact that it is moreactive against ergosterol-containing membranes of fungal cells than against mammalian membranes withcholesterol. In this paper, we examine the hypothesis according to which the selectivity of the AmB's membraneaction originates...
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Comparison of hydrochemistry and organic compound transport in two non-glaciated high Arctic catchments with a permafrost regime (Bellsund Fjord, Spitsbergen)
PublikacjaAn increase in air temperature related to climate change results in the retreat of glaciers, the degradation of permafrost, and the expansion of glacier-free areas in the polar regions. All these processes lead to changes in the Arctic landscape. They influence the hydrochemistry of streams and rivers fed by glaciers and thawing permafrost. In this study, we examine eighty two water samples from two non-glaciated catchments with...
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The managerial role in organizational culture as perceived by management students
PublikacjaThis paper aims at illustrating the multidimensional role of the manager and its mutual influence on organizational culture from amanagement students’ perspective. The main part of the text was based on own qualitative research – interviews, a questionnaire, and a narrative collage – which was conducted over a 10 year period among management students. Ninety-seven students from the Jagiellonian University and the Gdańsk University...
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Miniaturized uniplanar triple-band slot dipole antenna with folded radiator
PublikacjaA miniaturized uniplanar slot dipole for triple-frequency operation is presented. The antenna consists of a folded slot radiator with an increased number of degrees of freedom that allow for efficient size reduction. Rigorous electromagnetic (EM)-driven design optimization is applied in order to achieve the smallest possible size while maintaining acceptable levels of antenna reflection at the required operating frequencies. The...
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The role of slowly biodegradable substrate in a full-scale biological nutrient removal activated sludge systems
PublikacjaThis paper contains futher results obtained at ''Wschod'' WWTP in Gdańsk under transient conditions (spring season) and comparation of similar experiments carried out at a recently upgraded ''Debogorze'' WWTP in Gdynia. The removal of colloidal and particulate fractions resulted in similar effects (reduced process rates) at both plants. For example, the initial denitrification rates (NUR1) were up to 30% lower during the ''conventional''...
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HYBRID REDUCED MODEL OF ROTOR
PublikacjaIn the paper, the authors describe the method of model reduction of a rotor system. The proposed approach enables to obtain a low order model including e.g. nonproportional damping or the gyroscopic effect. This method is illustrated using the example of a rotor system. First, a model of the system was built without gyroscopic and damping effects by using the rigid finite element method. Next, this model was reduced. Finally, two...
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Geotechnical Aspects of Dike Construction Using Soil-Ash Composites
PublikacjaAn analysis of using of anthropogenic materials, mainly ashes from Coal Combustion Products (CCP), for dike construction is shown. Perspectives of anthropogenic materials application in geotechnical engineering and their advantages in sense of the carbon dioxide reduction are discussed. According to regulations of Kioto Protocol 2005 and EU agreement “Energy Roadmap 2050” recycled materials have higher usage priority than natural...
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Subcritical bifurcation of free elastic shell of biological cluster
PublikacjaIn this paper we will investigate symmetry-breaking bifurcation of equilibrium forms of biological cluster. A biological cluster is a two-dimensional analogue of a gas balloon. The cluster boundary is connected with its kernel by elastic links. The inside part is filled with compressed gas or fluid. Equilibrium forms of biological cluster can be found as solutions of a certain second order ordinary functional-differential equation...
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Public spaces connecting cities. Green and Blue Infrastructures potential.
PublikacjaA city fragmentation causes a lot of negative effects in urban environment such as: disconnecting the environmental, functional and compositional relations, a loss of urban compactness, chaotic development, visual chaos, a domination of technical landscape, reduction of security. This is why one of main challenges for urban planners is to connect the fragmented structures by creating friendly, attractive and safe public space....
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Automatic road traffic safety management system in urban areas
PublikacjaTraffic incidents and accidents contribute to decreasing levels of transport system reliability and safety. Traffic management and emergency systems on the road, using, among others, automatic detection, video surveillance, communication technologies and institutional solutions improve the organization of the work of various departments involved in traffic and safety management. Automation of incident management helps to reduce...
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Shape Optimisation of Kaplan Turbine Blades Using Genetic Algorithms
PublikacjaThis monograph is a comprehensive guide to a method of blade profile optimisation for Kaplan-type turbines. This method is based on modelling the interaction between rotor and stator blades. Additionally, the shape of the draft tube is investigated. The influence of the periodic boundary condition vs. full geometry is also discussed. Evolutionary algorithms (EA) are used as an optimisation method together with artificial neural...
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Fe local structure in Pt-free nitrogen-modified carbon based electrocatalysts: XAFS study
PublikacjaThe paper presents a new results on the bonding environment (coordination number and geometry) and on oxidation states of Fe in nitrogen-modified Fe/C composites used as Pt-free catalysts for oxygen reduction in Direct Hydrogen Fuel Cells. Starting from glucose or fructose, two catalysts displaying different electrochemical performance were prepared and studied in the form of pristine powder and thin catalytic layer of electrode...
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A recent developments in polyurethane foams containing a low-cost and pro-ecological modifiers
PublikacjaDiversity of the polyurethane (PU) foams applications cause that investigation of the relationships between their structure and properties is currently very popular topic among the many research institutions and companies. At the turn of the last years many scientific papers about PU foams and their composites were published. The one of the main research trends in this field is related to the reduction of production costs of...
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Oxygen biosensor based on carbon nanotubes directly grown on graphitic substrate
PublikacjaFilms of carbon nanotubes were synthesized on the graphitic substrates by CVD method in the presence of catalyst. Two different catalysts were used, that is nickel and iron, supported on graphitic substrates. The as-obtained nanotubes were analyzed by SEM imaging with EDX and Raman spectroscopy. The results revealed their multi-walled morphology. Free radical reaction was carried out in order to chemically functionalize synthesized...
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Examining the Impact of Distance Between VSL Road Signs on Vehicle Speed Variance
PublikacjaVariable speed limit (VSL) is an intelligent transportation system (ITS) solution for traffic management. The speed limits can be changed dynamically to adapt to traffic conditions such as visibility and traffic volume, curvature, and grip coefficient of the road surface. The VSL traffic sign location problem and attempts to solve it using computer simulation are presented in this paper. Experiments on a selected road segment,...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublikacjaPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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Dynamic Charging of Electric Buses as a Way to Reduce Investment Risks of Urban Transport System Electrification
PublikacjaNight charging and fast charging are currently the two most common systems for charging electric buses. Despite the fact that numerous trial installations were started, neither of these two systems has obtained unqualified approval of the users. The alternative is to charge vehicles in motion - dynamic charging which combines the advantages of trolleybus transport and of electric buses. One of the advantages is the reduction of...
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Regularized Local Basis Function Approach to Identification of Nonstationary Processes
PublikacjaThe problem of identification of nonstationary stochastic processes (systems or signals) is considered and a new class of identification algorithms, combining the basis functions approach with local estimation technique, is described. Unlike the classical basis function estimation schemes, the proposed regularized local basis function estimators are not used to obtain interval approximations of the parameter trajectory, but provide...
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Zarządzanie programami badawczymi z uwzględnieniem filozofii nauki
PublikacjaZarządzanie projektami i programami badawczymi powinno być realizowane z zastosowaniem specyficznych metod zarządzania ze względu na specyfikę badań naukowych. W tym rozdziale zaprezentowano wyniki analiz mających na celu lepsze zrozumienie roli zarządzania programem badawczym z następujących perspektyw: analizy rzeczywistości projektów badawczych, zarządzania projektem i programem oraz filozofii nauki. Praktycznym zastosowaniem...
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Optimization-Based High-Frequency Circuit Miniaturization through Implicit and Explicit Constraint Handling: Recent Advances
PublikacjaMiniaturization trends in high-frequency electronics have led to accommodation challenges in the integration of the corresponding components. Size reduction thereof has become a practical necessity. At the same time, the increasing performance demands imposed on electronic systems remain in conflict with component miniaturization. On the practical side, the challenges related to handling design constraints are aggravated by the...
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Cavitation-based technologies for pretreatment and processing of food wastes: Major applications and mechanisms – A review
PublikacjaConversion of food wastes to valuable products is an important topic for sustainable development. Feedstock hydrolysis is a stage strongly affecting the anaerobic digestion process, and resistance of food waste towards hydrolysis causes a decrease in product yield. Such as biomethane, biohydrogen, biohythane, VFAs, and lactic acids. Moreover, mass transfer is a serious limitation of transesterification for the production of biodiesel....
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Experimental investigation of thermal energy storage in shell-and-multi-tube unit with nano-enhanced phase change material
PublikacjaThis paper deals with thermal energy storage with use of nanoparticle enhanced phase change material in shell-and-multitube unit. The experiments are conducted under atmospheric pressure. Paraffin wax and two different fatty acids are used as base phase change material. Graphite and multi-walled carbon nanotubes serve as nanoparticles. Graphite nanoparticles are tested at the concentrations of 0.1%, 1% and 5% by weight, while multi-walled...
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Forced vibrations in a dynamic system that is damped by a mechanism that trans-pass through its singular position
PublikacjaIn the paper, vibrations of a hybrid multibody-continuous system are investigated. For all the mechanical devices, effective damping methods are crucial in the design process. To obtain it, installation of viscous dampers or elasto-viscous elements is dominant. In the paper, an alternative method is investigated. It is based on modal disparity. To describe the method briefly, when structural damping is present in continuous systems,...
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Exsolution of Ni nanoparticles on the surface of cerium and nickel co-doped lanthanum strontium titanate as a new anodic layer for DIR-SOFC. Anti-coking potential and H2S poisoning resistance of the prepared material
PublikacjaThe aim of this study was to evaluate a new catalytic material for biogas fueled DIR-SOFC. This material was a perovskite-type SrTiO3 doped with La, Ce and Ni of a general formula La0.27Sr0.54Ce0.09Ni0.1Ti0.9O3-σ (LSCNT). Additional preparation steps were undertaken to promote a nickel exsolution process. Heat post-treatment of powders in a humidified H2 resulted in an intensive growth of nickel nanoparticles (NPs) while the temperature...
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Influence of dispersed phase content on the mechanical properties of electroless nanocomposite Ni-P/Si3N4 and hybrid Ni-P/Si3N4/graphite layers deposited on the AW-7075 alloy.
PublikacjaThe article presents the results of mechanical testing of Ni-P/Si3N4 nanocomposite and hybrid Ni-P/Si3N4/graphite coatings deposited on AW-7075 aluminum alloy using the chemical reduction method. In terms of mechanical testing, microhardness was measured, and surface roughness and adhesion of the coatings to the aluminum substrate were determined using the “scratch test” method. The surface morphology of the deposited layers was...
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Eco-friendly Route for Thermoplastic Polyurethane Elastomers with Bio-based Hard Segments Composed of Bio-glycol and Mixtures of Aromatic–Aliphatic and Aliphatic–Aliphatic Diisocyanate
PublikacjaApplication of bio-based diisocyanates with low volatility instead petrochemical diisocyanates has positive impact on environment by reduction of hazardous effects on living organisms and lead to bio-based polyurethanes (bio-PUs) with good usage properties. This work was focused on the synthesis and chosen properties examination of partially bio-based thermoplastic polyurethane elastomers (bio-PUs) obtained using diisocyanate mixtures,...
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Surface Treatment of Rubber Waste
PublikacjaThis chapter deals with the study of different approaches to improve the compatibility of waste rubber with polymeric matrixes of high density polyethylene (HDPE) by using surface treatments to increase adhesion. Different surface treatments such as etching with sulphuric and nitric acids, the use of a silane as a coupling agent and chlorination with trichloroisocyanuric acid (TCI) have been applied. The modification of waste rubber...
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Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
PublikacjaEngineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have...
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The influence of frequency separation on imaging properties in DFEIT
PublikacjaW artykule przedstawiono wpływ wyboru składowych częstotliwościowych dla różnicowej tomografii impedancyjnej na wynik i własności obrazowania w dwuczęstotliwościowej różnicowej tomografii impedancyjnej.A Dual Frequency EIT is an extension of a traditional EIT that uses two sinusoidal signals for imaging. Appropriate selection of signals' frequency allows to achieve reasonable contrast of imaged structure. It has already been shown...
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Optimization of Chemical Functionalities of Indole-2-carboxamides To Improve Allosteric Parameters for the Cannabinoid Receptor 1 (CB1)
Publikacja5-Chloro-3-ethyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (1; ORG27569) is a prototypical allosteric modulator for the cannabinoid type 1 receptor (CB1). Here, we reveal key structural requirements of indole-2-carboxamides for allosteric modulation of CB1: a critical chain length at the C3-position, an electron withdrawing group at the C5-position, the length of the linker between the amide bond and the phenyl ring...
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Hydration of amino acids: FTIR spectra and molecular dynamics studies
PublikacjaThe hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results,...
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Accelerated design optimization of miniaturized microwave passives by design reusing and Kriging interpolation surrogates
PublikacjaElectromagnetic (EM) analysis has become ubiquitous in the design of microwave components and systems. One of the reasons is the increasing topological complexity of the circuits. Their reliable evaluation—at least at the design closure stage—can no longer be carried out using analytical or equivalent network representations. This is especially pertinent to miniaturized structures, where considerable EM cross-coupling effects occurring...
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Accelerated multi-objective design of miniaturized microwave components by means of nested kriging surrogates
PublikacjaDesign of microwave components is an inherently multiobjective task. Often, the objectives are at least partially conflicting and the designer has to work out a suitable compromise. In practice, generating the best possible trade‐off designs requires multiobjective optimization, which is a computationally demanding task. If the structure of interest is evaluated through full‐wave electromagnetic (EM) analysis, the employment of...
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Reliable Surrogate Modeling of Antenna Input Characteristics by Means of Domain Confinement and Principal Components
PublikacjaA reliable design of contemporary antenna structures necessarily involves full-wave electromagnetic (EM) analysis which is the only tool capable of accounting, for example, for element coupling or the effects of connectors. As EM simulations tend to be CPU-intensive, surrogate modeling allows for relieving the computational overhead of design tasks that require numerous analyses, for example, parametric optimization or uncertainty...
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Enhanced interfacial and mechanical performance of styrene-butadiene rubber/silica composites compatibilized by soybean oil derived silanized plasticization
PublikacjaSilanized plasticizer (SP) was chemically derived and synthesized from soybean oil (SBO) co-vulcanized with bis-(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT) by using the sulfur-accelerated curing system. SP extended styrene-butadiene rubber (SBR)/silica composites have been studied for their improved filler dispersion through coupling interaction at the SBR/silica interface. The effect of SP on cross-link density, thermal,...
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Subjective Quality Evaluation of Underground BPL-PLC Voice Communication System
PublikacjaDesigning a reliable voice transmission system is not a trivial task. Wired media, thanks to their resistance to mechanical damage, seem an ideal solution. The BPL-PLC (Broadband over Power Line – Power Line Communication) cable is resilient to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency situation, including paramedic rescue operations. These features...
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Axial-Flux Permanent-Magnet Dual-Rotor Generator for a Counter-Rotating Wind Turbine
PublikacjaCoaxial counter-rotating propellers have been widely applied in ships and helicopters for improving the propulsion efficiency and offsetting system reactive torques. Lately, the counter-rotating concept has been introduced into the wind turbine design. Distributed wind power generation systems often require a novel approach in generator design. In this paper, prototype development of axial-flux generator with a counter-rotating...
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Editorial for the special issue on advances in forward and inverse surrogate modeling for high-frequency design
PublikacjaThe design of modern‐day high‐frequency devices and circuits, including microwave/RF, antenna and photonic components, historically has relied on full‐wave electromagnetic (EM) simulation tools. Initially used for design verification, EM simulations are nowadays used in the design process itself, for example, for finding optimum values of geometry and/or material parameters of the structures of interest. In a growing number of...
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Quality Evaluation of Speech Transmission via Two-way BPL-PLC Voice Communication System in an Underground Mine
PublikacjaIn order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability...
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Engineering TADF, Mechanochromism, and Second Harmonic Up- conversion Properties in Regioisomeric Substitution Space
PublikacjaThis research article explores the distinct TADF efficiency of three donor-acceptor based regio-isomers: DPAOCN (ortho- isomer), DPAMCN (meta-isomer), and DPAPCN (para-isomer). DPAPCN exhibits maximum TADF efficiency in both solution and solid-state with an impressive reverse inter-system crossing (RISC) rate of ~ 106 s-1; the underlying cause being the minimum singlet-triplet splitting energy or ∆EST and maximum SOC (spin-orbit...
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Compact, Order Extensible and Wide-Stopband Bandpass Filter Based on SIW Cavity with Rectangular Ring Slot
PublikacjaThis article introduces novel architectures of bandpass filters (BPFs) using a substrate integrated waveguide (SIW) cavity with a rectangular ring slot (RRS) for compact size, extensible order, and broad stopband responses. Two bandpass filters, which demonstrate a second-and a fourth-order Chebyshev response, respectively, are realized by employing identical cavities with RRS, without increasing the physical size of the circuit....
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Fast Design Closure of Compact Microwave Components by Means of Feature-Based Metamodels
PublikacjaPrecise tuning of geometry parameters is an important consideration in the design of modern microwave passive components. It is mandatory due to limitations of theoretical design methods unable to quantify certain phenomena that are important for the operation and performance of the devices (e.g., strong cross-coupling effects in miniaturized layouts). Consequently, the initial designs obtained using analytical or equivalent network...
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Influence of Wood Moisture on Strength and Elastic Modulus for Pine and Fir Wood Subjected to 4-point Bending Tests
PublikacjaThe main purpose of this research paper was to determine the influence of the wood moisture on the strength and elastic modulus of pine and fir wood specimens subjected to the 4-point bending tests. Six bending tests for each wood species and for two different moisture level have been performed. Then, the advanced statistical analysis of the results has been carried out. On the basis of the obtained results, it has been noted that...
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Controling w zarządzaniu bezpieczeństwem pracy
PublikacjaW artykule przedstawiono możliwość wykorzystania controllingu do badania zagrożeń w procesie pracy. Dla oceny rozwiązań usprawniających wprowadzono pojęcie oszczędności zasobu typu praca i typu materiał, zużywanych w procesie realizacji zadań wytwórczych. Artykuł podkreśla możliwość osiągania efektów ekonomicznych (ograniczenia kosztów) w wyniku poprawy warunków pracy.CONTROLLING IN WORK SAFETY MANAGEMENTThe article presents the...
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Automatic sound recognition for security purposes
PublikacjaIn the paper an automatic sound recognition system is presented. It forms a part of a bigger security system developed in order to monitor outdoor places for non-typical audio-visual events. The analyzed audio signal is being recorded from a microphone mounted in an outdoor place thus a non stationary noise of a significant energy is present in it. In the paper an especially designed algorithm for outdoor noise reduction is presented,...