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Search results for: wavelet transforms
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ASPEKTY BEZPIECZEŃSTWA W OCENIE WYNIKÓW POMIARÓW UZIEMIEŃ ODGROMOWYCH
PublicationOcena rozległego systemu za pomocą metod wykorzystujących przebiegi wolnozmienne prowadzi do zbyt optymistycznych wniosków odnośnie ich właściwości podczas odprowadzania prądów wyładowań atmosferycznych. Bardziej bezpieczne wnioski powstają w wyniku pomiarów z zastosowaniem metody wykorzystującej przebiegi impulsowe, ponieważ wtedy jest uwzględniana tylko ta część nawet bardzo rozległego systemu uziemień, która bierze udział w...
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Passing from requirements specification to class model using application domain ontology
PublicationThe quality of a classic software engineering process depends on the completeness of project documents and on the inter-phase consistency. In this paper, a method for passing from the requirement specification to the class model is proposed. First, a developer browses the text of the requirements, extracts the word sequences, and places them as terms into the glossary. Next, the internal ontology logic for the glossary needs to...
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Pipelined division of signed numbers with the use of residue arithmetic in FPGA
PublicationAn architecture of a pipelined signed residue divider for small number ranges is presented. The divider makes use of the multiplicative division algorithm where initially the reciprocal of the divisor is calculated and subsequently multiplied by the dividend. The divisor represented in the signed binary form is used to compute the approximated reciprocal in the residue form by the table look-up. In order to reduce the needed length...
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Application of sliding switching functions in backstepping based speed observer of induction machine
PublicationThe paper presents an analysis of the speed observer which is based on the backstepping and sliding mode approach. The speed observer structure is based on the extended mathematical model of an induction machine. The observer structure is based on the measured phase stator currents and transformed to ( αβ ) coordinate system. The stator voltage vector components are treated as known values. Additionally, such an observer structure...
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Feedback Control of Multiphase Induction Machines with Backstepping Technique
PublicationThe paper presents the control possibility of five phase induction machines. In the proposed solution the machine model vector form is not transformed to the (dq)-coordinate system, that is connected to rotor flux vector, but utilizes the stationary system ( αβ ). Moreover, the nonlinear model linearization is based on demonstrated nonlinear variables transformation for i-orthogonal ( αβ )(n) planes. By introducing the backstepping...
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Global Optimization for Recovery of Clipped Signals Corrupted With Poisson-Gaussian Noise
PublicationWe study a variational formulation for reconstructing nonlinearly distorted signals corrupted with a Poisson-Gaussian noise. In this situation, the data fidelity term consists of a sum of a weighted least squares term and a logarithmic one. Both of them are precomposed by a nonlinearity, modelling a clipping effect, which is assumed to be rational. A regularization term, being a piecewise rational approximation of the ℓ0 function...
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Performance evaluation of parallel background subtraction on GPU platforms
PublicationImplementation of the background subtraction algorithm on parallel GPUs is presented. The algorithm processes video streams and extracts foreground pixels. The work focuses on optimizing parallel algorithm implementation by taking into account specific features of the GPU architecture, such as memory access, data transfers and work group organization. The algorithm is implemented in both OpenCL and CUDA. Various optimizations of...
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Parameters optimization in medicine supporting image recognition algorithms
PublicationIn this paper, a procedure of automatic set up of image recognition algorithms' parameters is proposed, for the purpose of reducing the time needed for algorithms' development. The procedure is presented on two medicine supporting algorithms, performing bleeding detection in endoscopic images. Since the algorithms contain multiple parameters which must be specified, empirical testing is usually required to optimise the algorithm's...
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Establishment of the Right of Electricity Transmission Easement Through Court Proceedings
PublicationIncluding the amendment of the Civil Code Act on May 30, 2008, issues related to the right of easement of transmission were introduced to it. Such a regulation was necessary in view of the need to define the legal status of transmission facilities, existing and designed on real estate property. The purpose of the study is to analyze issues related to the definition of the spatial extent of the law of transmission easement for power...
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Prosthetic Elements Made of the Ti-13Zr-13Nb Alloy by Selective Laser Melting
PublicationThe fabrication of the prosthetic foundations and bridges from the Ti-13Zr-13Nb alloy is described. The process was started from CAD/CAM design of 3D models of the foundations based on scanning of patient`s mouth. Next, 3D models were transformed into *.stl files for the manufacturing stage and then the manufacturing process by means of the selective laser melting with the SLM Realizer 100 equipment was made. The intrinsic structure...
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Straightened characteristics of McKendrick-von Foerster equation
PublicationWe study the McKendrick-von Foerster equation with renewal (that is the age-structured model, with total population dependent coefficient and nonlinearity). By using a change of variables, the model is then transformed to a standard age-structured model in which the total population dependent coefficient of the transport term reduces to a constant 1. We use this transformation to get existence, uniqueness of solutions of the problem...
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Isogeometric Shell FE Analysis of the Human Abdominal Wall
PublicationIn this paper a nonlinear isogeometric Kirchhoff-Love shell model of the human abdominal wall is proposed. Its geometry is based on in vivo measurements obtained from a polygon mesh that is transformed into a NURBS surface, and then used directly for the finite element analysis. The passive response of the abdominal wall model under uniform pressure is considered. A hyperelastic membrane model based on the Gasser-Ogden-Holzapfel...
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Jeffreys heat conduction in coupled semispaces subjected to interfacial heating
PublicationA Jeffreys heat conduction problem for coupled semispaces subjected to the action of an interfacial heat source was defined. An analytical solution of the problem was derived for a polynomial specific power of the heat source using the Laplace transform approach. The asymptotic and parametric analysis was performed for different ratios of thermal conductivities , thermal diffusivities , thermal relaxation times and coefficients...
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Chemical composition, antioxidant and anticancer effects of the seeds and leaves and indigo (polygonum tinctorium Ait.) Plant
PublicationSeeds and leaves of indigo (Polygonum tinctorium Ait.) plant were investigated and compared with another medicinal plant named prolipid for their properties such as chemical composition, antioxidant, and anticancer effects by Fourier transform infrared, three-dimensional fluorescence spectroscopy, and electrospray ionization-MS in negative mode. It was found that polyphenols, flavonoids, and flavanols were significantly higher...
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Roughness evaluation of turned composite surfaces by analysis of the shape of Autocorrelation Function
PublicationIn this paper, the application of an Autocorrelation Function for the characterisation of surface topography was validated. The roughness evaluation of turned composite surfaces was supported by sophisticated studies of the Autocorrelation Function properties, considering especially the shape of the function. Details were measured with the optical method. The selection of the surface roughness evaluation procedures was carried...
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Structural and luminescence properties of B2O3-Bi2O3-AlF3 glass doped with Eu3+, Tb3+ and Tm3+ ions
PublicationThe B2O3-Bi2O3-AlF3 glass system doped with Eu3+, Tb3+, Tm3+ and triply doped with Eu3+/Tm3+/Tb3+ ions in different molar ratios were successfully synthesized. Glass transition and crystallization temperatures were examined by Differential Scanning Calorimetry (DSC) measurements. X-ray Diffraction (XRD) confirmed the amorphous character of the samples. Fourier Transform Infrared Spectroscopy (FTIR) revealed that the glass matrix...
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A Comprehensive Analysis of Impedance of the Electrochemical Cell
PublicationA comprehensive impedance characteristics of two electrodes electrochemical cell has been pre sented. In this method a multisinusoidal current excitation signal is used. The change of potential of both the electrodes are all registered as a function of time. The proposed method gives the possibility of determining the impedance of both electrodes individually as well as the impedance of a twoelectrode system. Additional application...
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Determination of modifier contents in polymer-modified bitumens and in samples collected from the roads using high performance gel permeation/size exclusion chromatography
PublicationThis paper describes application of high performance gel permeation/size exclusion chromatography (HP-GPC/SEC) for the determination of content of polymer modifiers in modified road bitumens. The obtained results were compared with the measurements based on the procedure recommended by the American Association of State Highway and Transportation Officials, which employs Fourier transform mid-infrared spectroscopy (mid-IR FTIR)....
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Fast High-Impedance Spectroscopy Method Using SINC Signal Excitation
PublicationIn this paper the method of fast impedance spectroscopy of technical objects with high impedance (|Zx| > 1 Gohm) is evaluated by means of simulation and practical experiment. The method is based on excitation of an object with a sinc signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance spectrum is obtained with use of continuous Fourier transform...
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Physico‐Mechanical Properties and Flammability of PUR/PIR Foams Containing Expandable Graphite Core‐Shell Composite Particles
PublicationIn this work, polyurethane/polyisocyanurate (PUR/PIR) foams were modified by two types of expandable graphite (EG) core-shell composite particles. The pulverized EG core-shell composite particles were prepared during emulsion polymerization using methyl methacrylate or glycidyl methacrylate for the synthesis of the polymeric shells (poly(methyl methacrylate) (PMMA) and poly (glycidyl methacrylate) (PGMA)), and then the obtained EG_PMMA...
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Analyzing energy/performance trade-offs with power capping for parallel applications on modern multi and many core processors
PublicationIn the paper we present extensive results from analyzing energy/performance trade-offs with power capping observed on four different modern CPUs, for three different parallel applications such as 2D heat distribution, numerical integration and Fast Fourier Transform. The CPU tested represent both multi-core type CPUs such as Intel⃝R Xeon⃝R E5, desktop and mobile i7 as well as many-core Intel⃝R Xeon PhiTM x200 but also server, desktop...
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Chemical modifications of graphene and their influence on properties of polyurethane composites: a review
PublicationPolyurethane composites are materials of great interest nowadays due to their wide range of available forms and applications in industry. Controlling and achieving unique properties via matrix modifications and addition of various specific nanofillers seems be one of the key elements to success. The purpose of this work is to briefly present some examples of graphene nanoderivatives, their syntheses, properties and influence on...
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Improvement of opipramol base solubility by complexation with β-cyclodextrin
PublicationOpipramol (OPI), a tricyclic antidepressant and anxiolytic compound, is administered orally in the form of a dihydrochloride. Salt form of the drug has a higher solubility in water and hence bioavailability and stability. A similar effect can be achieved by closing the hydrophobic part of the drug molecule in the cyclodextrin cavity. The paper presents opipramol inclusion complexes with beta-cyclodextrin (β-CD) in 1:1 molar ratio....
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Reclaimed Rubber/Poly(ε‐caprolactone) Blends: Structure, Mechanical, and Thermal Properties
PublicationThe amount of elastomeric waste, especially from tires is constantly increasing on a global scale. The recycling of these residua should be considered a priority. Compounding the waste rubbers with other polymers can be an excellent alternative to reuse waste materials. This procedure requires solving the issue of the lack of compatibility between the waste rubber particles and other polymers. Simultaneously, there is a claim for...
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HISTORY OF INITIAL ENERGY AND WATER NETWORK DEVELOPMENT IN QATAR
PublicationQatar: A country which had to be associated with neighboring countries like UAE or Saudi Arabia for people to know about it, stands proud today due to the ample production and exporting of Black Gold. A country with almost no vegetation or suitable weather to harvest crops, turned from being heavily dependent on trading Pearls to exporting natural oil and gas to all over the globe. The paper outlines in details the history of the...
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Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction
PublicationThe instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction...
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Structure-rheology relationship of fully bio-based linear polyester polyols for polyurethanes - Synthesis and investigation
PublicationThe synthesis of polyols from renewable substances as an alternative for petrochemical-based polyols play important matter in the polyurethane industry. In this work, the fully bio-based linear polyester polyols with different catalyst amounts were synthesized via two-step polycondensation method. The effect of various catalyst content on the structure and rheological behavior were established. Fourier Transform Infrared Spectroscopy,...
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Insights into Compatibilization of Poly(ε-caprolactone)-based Biocomposites with Diisocyanates as Modifiers of Cellulose Fillers
PublicationThis study aimed to analyze the impact of cellulose fillers’ modification with diisocyanates on the performance of composites based on the poly(ε-caprolactone) (PCL) matrix. Four most commonly used diisocyantes (isophorone, hexamethylene, toluene, and methylene diphenyl) were applied as modifiers of cellulose fillers (5 and 15 wt% per mass of filler). Modified fillers were introduced in the amount of 30 wt% into the PCL matrix....
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Investigating Feature Spaces for Isolated Word Recognition
PublicationMuch attention is given by researchers to the speech processing task in automatic speech recognition (ASR) over the past decades. The study addresses the issue related to the investigation of the appropriateness of a two-dimensional representation of speech feature spaces for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and timefrequency signal representation...
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Cost-Effective Piggyback Forward dc-dc Converter
PublicationThe novel piggyback dc-dc converter as a cost-effective solution is presented in this work. It provides a wide input voltage range of regulation with a low component count. The novel solution is an advanced forward dc-dc converter with an additional clamp output capacitor. The idea of such a type of converter is to transfer magnetizing energy of transformer to the output side, instead of using input clamp circuit. The design guidelines...
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Nested Space Mapping Technology for Expedite EM-driven Design of Compact RF/microwave Components
PublicationA robust simulation-driven methodology for rapid and reliable design of RF/microwave circuits comprising compact microstrip resonant cells (CMRCs) is presented. We introduce a nested space mapping (NSM) technology, in which the inner space mapping layer is utilized to improve the generalization capabilities of the equivalent circuit model corresponding to a constitutive element of the circuit under consideration. The outer layer...
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THE INFLUENCE OF THE EVOLUTION OF DAYLIGHTING SYSTEMS OF EXHIBITION SPACE ON THE ARCHITECTURE OF THE MUSEUM'S BUILDING
PublicationThe paper deals with the architecture of museums as dependent on the ways of lighting the exhibition space. The work focuses on the analysis of the influence of daylighting systems on shaping the museum's architecture in the period from the Renaissance to modern times. The method of work includes studying literature and the case study of the objects characteristic of the presented concepts and lighting systems. The results of the...
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Dyskretno-ciągła metoda modelowania układów dynamicznych
PublicationW artykule przedstawiono oryginalną metodę modelowania układów dyskretno-ciągłych. Metoda polega na dyskretyzowaniu układu trójwymiarowego jedynie w dwóch wybranych kierunkach. W trzecim z kierunków układ pozostaje ciągły. Otrzymany w ten sposób model jest modelem dyskretno-ciągłym. Opisany jest za pomocą równań różniczkowych cząstkowych. Ogólne równania różnicowe układu dyskretnego otrzymano, wykorzystując metodę sztywnych elementów...
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Dc Leakage Current in Isolated Grid-Connected dc Nanogrid - Origins and Elimination Methods
PublicationThe LV dc system is a relatively new trend in the distribution sector, which seems to grow widely in the near future due to its promising advantages. In this context, LV dc protection and grounding are challenging issues. Although the galvanically isolated connection mode of dc nanogrid to the ac grid has high reliability, the leakage current can still be injected into the ac grid through the interwinding capacitors and the insulation...
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Financial aspects of supporting Ukrainian refugees
PublicationWarfare in Ukraine meant that in 2022 many countries, including Poland and other European, focused mainly on helping refugees from Ukraine and humanitarian transports. The assistance took on various forms - from basic humanitarian support, through in-kind help, financial and military assistance. Poland launched its humanitarian aid in the first days of the conflict. The aid provided by each country varies. It should be noted, however,...
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Instance segmentation of stack composed of unknown objects
PublicationThe article reviews neural network architectures designed for the segmentation task. It focuses mainly on instance segmentation of stacked objects. The main assumption is that segmentation is based on a color image with an additional depth layer. The paper also introduces the Stacked Bricks Dataset based on three cameras: RealSense L515, ZED2, and a synthetic one. Selected architectures: DeepLab, Mask RCNN, DEtection TRansformer,...
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Potrzeby osób z niepełnosprawnością a budżet obywatelski. Wyniki ankiety opinii wśród społeczności warszawskiego Muranowa
PublicationThe participatory budget in Warsaw is a form of citizen involvement in city planning. The projects submitted in the budget concern, among other things, the physical transformation of space, organizing events integrating the community, and educational programs. Each of the above categories may determine the inclusion of people with disabilities in society. Social inclusion in the perspective of city change is an interesting and...
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Maszyny elektryczne wokół nas. Poszukiwanie dróg do nauczania na kierunku Elektrotechnika Politechniki Gdańskiej = Electrical machines around us. searching for teaching ways at electrical engineering of the Gdansk University of Technology
PublicationStreszczenie angielskie: This paper provides a summary of the didactic assumptions, goals and approach concerning the syllabus and description/modelling of electrical machines (EM) for teaching in the field of power electrical engineering at the Gdansk University of Technology. They have been used to write e-text book entitled "Electrical machines around us" that covered the lectures on electrical machines given for the second...
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Urban Freight Transport Demand Modelling and Data Availability Constraints
PublicationThe paper provides a review of urban freight transport demand modelling approaches confronted with constrains regarding adequate data provision from a perspective of the local authorities. Demand estimation models has been selected as a reference because they are the most representative in terms of inclusion of urban freight indicators which can be transformed into a decision-support tool for evaluation of freight measures. The...
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Copper and cobalt co-doped ceria as an anode catalyst for DIR-SOFCs fueled by biogas
PublicationThe nanocrystalline compounds of Co and Cu co-doped ceria (with up to 20 mol.% of dopants) were fabricated by the reverse microemulsion synthesis method. They were deposited in a form of layers on the surface of SOFC anode in an aim to act as electrochemically active materials for biogas reforming process. Fourier Transformed Infrared Spectroscopy was used to analyze a composition of outlet gases simultaneously with the tests of...
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HYDROGEN PRODUCTION PERFORMANCE IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF NI3AL
PublicationThe main aim of the following paper is mathematical modelling for momentum, heat and mass transfer, which is accompanied by chemical surface reactions of the flow of the mixture helium and methanol. The thermocatalytic devices used for decomposition of hydrocarbons incorporate vertical microchannels coupling at the ends and heated to 500 oC at the walls. The results of the experiment were compared with CFD calculations to calibrate...
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A sense of security and freedom in a residential environment
PublicationThe article is based on the results of a survey carried out among students of architecture faculties in several countries, which examined the students’ knowledge of shaping the housing environment in such a way as to enable them to fulfil two basic and, at the same time, seemingly mutually exclusive psychological needs of a person: a sense of security and a sense of freedom. In examining these issues, particular emphasis was placed...
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A Conformal Circularly Polarized Series-Fed Microstrip Antenna Array Design
PublicationA conformal circularly polarized series-fed microstrip array design for broadside radiation is presented. The array aperture under design is conformal to a cylindrical surface of a given radius. The approach we present primarily addresses focusing of the circularly polarized major lobe of the conformal array by proper dimensioning of the aperture spacings. The proposed analytical models yield the values of the element spacings...
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Challenges for universities in the face of the knowledge-based economy - Directions for higher education institutions in the Baltic Sea Region
PublicationThe aim of this paper is to present new challenges that are faced by universities in the knowledge-based economy. There are several phenomena that can presently be observed like the need for life-long learning or interdisciplinary approach, and universities should prepare their graduates for those challenges. One of the crucial questions that universities need to ask is how to teach and what to teach. Knowledge becomes obsolete...
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Challenges for universities in the face of knowledge-based economy - directions for higher education institutions in the Baltic Sea Region
PublicationThe aim of this paper is to present new challenges that are faced by universities in the knowledge-based economy. There are several phenomena that can presently be observed like the need for life-long learning or interdisciplinary approach, and universities should prepare their graduates for those challenges. One of the crucial questions that universities need to ask is how to teach and what to teach. Knowledge becomes obsolete...
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Isolation and structure of a covalent cross-link adduct between mitomycin C and DNA
PublicationA DNA cross-link adduct of the antitumor agent mitomycin C (MC) to DNA has been isolated and characterized; the results provide direct proof for bifunctional alkylation of DNA by MC. Exposure of MC to Micrococcus luteus DNA under reductive conditions and subsequent nuclease digestion yielded adducts formed between MC and deoxyguanosine residues. In addition to the two known monoadducts, a bisadduct was obtained. Reductive MC activation...
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Copper Slag as a Potential Waste Filler for Polyethylene-Based Composites Manufacturing
PublicationThe present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile...
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Properties of Different Varieties of Durian
PublicationDurian (Durio zibethinus Murr.), like many other exotic, tropical, and conventional fruits, is important in the prevention of different diseases. In this study, the characterization of the main bioactive compounds of the most popular cultivars of durian and their properties are described. The changes in the quality indices of the antioxidant status were determined by CUPRAC, ABTS, FRAP, DPPH, and ORAC assays. The profiling of phytochemicals...
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Nonlocalized thermal behavior of rotating micromachined beams under dynamic and thermodynamic loads
PublicationRotating micromachined beams are one of the most practical devices with several applications from power generation to aerospace industries. Moreover, recent advances in micromachining technology have led to huge interests in fabricating miniature turbines, gyroscopes and microsensors thanks to their high quality/reliability performances. To this end, this article is organized to examine the axial dynamic reaction of a rotating...
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Artificial intelligence in architectural education - green campus development research
PublicationThe rapid advancement of artificial intelligence (AI) technologies has introduced new possibilities and challenges in design education. This article explores the need for changes and adaptations in the teaching process of design as AI-related technologies, based on image generation, transform the creative process and offer novel opportunities. In a research-by-design studio in an architectural faculty in Poland, students who utilised...