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Gdańsk University of Technology

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  • The use of a two-phase Monte Carlo material model to reflect the dispersion of asphalt concrete fracture parameters
    • Cezary Szydłowski
    • Łukasz Smakosz
    • Marcin Stienss
    • Jarosław Górski
    2022 Full text THEORETICAL AND APPLIED FRACTURE MECHANICS

    The work covers comprehensive laboratory tests of semi-circular bending (SCB) of asphalt concrete samples. The results of two test series, including four and 32 SCB specimens, indicate a substantial scatter of force–deflection (F-d) histories. The numerical analysis is aimed to reflect the maximum breaking load and fracture energy of the samples, pointing out their random character. The original simulation-based fictitious Monte Carlo material model was introduced. The authors’ algorithm randomly assigns asphalt mortar and coarse aggregate parameters to the finite elements of the numerical model. As a result, sets of random fields are generated to reflect the two-phase material distribution in the samples. The model parameters are numerically adjusted based on laboratory test results of the initial four SCB specimens. In the course of model verification, the 32-sample computations were compared with the laboratory data. The results of FEM simulations are consistent with laboratory test results, including dispersion of fracture parameters. The proposed computational algorithm with a two-phase material model is ready to be implemented in the analysis of actual road pavement constructions and may support the design process.

  • The Use of Direct Shear Test for Optimization of Interlayer Bonding Under a Poroelastic Layer
    • Piotr Jaskuła
    • Dawid Ryś
    • Marcin Stienss
    • Cezary Szydłowski
    2022

    Poroelastic Road Surfaces (PERS) are characterised by porous structure with air void content of 20% or higher and stiffness almost 10 times lower than that of a standard asphalt course. Such properties enable noise reduction by up to 12 dB in comparison to SMA 11 mixture. However, the disadvantage of a poroelastic pavement is its low durability, which partially results from delamination from the lower layer. The paper aims to investigate the effect of type and amount of tack coat used as well as the texture of the lower layer on interlayer bonding, to better recognise the issue of bonding under the poroelastic layer. For this purpose, direct shear test with monotonic and cyclic load was performed for 44 types of layer interfaces. The effect of type and amount of bituminous emulsion used for tack coat as well as the impact of lower layer surface were distinguished. The results of the analysis indicated that tack coats made from softer residual bitumen (70/100) exhibited better fatigue resistance, while polymer modification had minor effect. Moreover, milling of the lower layer resulted in a significant increase in shear strength. Finally, several types of layer interfaces were selected to be constructed in the full-scale test sections.

  • The use of GFRP tubes as load-bearing jackets in concrete-composite columns
    • Marcin Abramski
    • Błażej Chmielnicki
    2022 Full text Civil and Environmental Engineering Reports

    The paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions were formulated regarding the relationship between the load-bearing capacity of the test elements and their length, as well as the angle of glass fibres arrangement in the tube composite.

  • The use of machine learning for face regions detection in thermograms
    • Mariusz Kaczmarek
    • Julia Guzik
    2022

    The aim of this study is to analyse the methods of detecting characteristic points of the face in thermographic images. As part of the implementation an extensive analysis of scientific publications covering similar issues both for the analysis of images made in visible light and thermographic images was carried out. On the basis of this analysis, 3 models were selected and then they were implemented and tested on the basis of test images. Finally, two models were selected, the operation of which was documented on thermographic images - DAN and AAM, as well as one model that was tested for RGB images - the ERT model. Satisfactory detection parameters were achieved in the experiment.

  • The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries
    • M. Prześniak-Welenc
    • Małgorzata Nadolska-Dawidowska
    • Kacper Jurak
    • J. Li
    • K. Górnicka
    • A. Mielewczyk-Gryń
    • M. Rutkowska
    • A. P. Nowak
    2022 Full text Scientific Reports

    Potassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g−1, and long-term cyclic stability up to 100 cycles at 1 A g−1. The effect of the vanadium valence state and unusual construction of the nanobelts, composed of crystalline and amorphous domains arranged alternately were also discussed in this work. The ex-situ measurements of discharged electrode materials by XRD, MP-AES, XAS and XPS show that during the subsequent charge/discharge cycle the potassium in the K2V6O16·nH2O structure are replacing by lithium. The structural stability of the potassium hexavandate during cycling depends on the initial vanadium valence state on the sample surface and the presence of the “fringe free” domains in the K2V6O16·nH2O nanobelts.

  • The vibration-based assessment of the influence of elevated temperature on the condition of concrete beams with pultruded GFRP reinforcement
    • Beata Zima
    • Marcin Krajewski
    2022 Full text COMPOSITE STRUCTURES

    Concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars subjected to elevated temperature have been experimentally studied. The influence of high temperatures on GFRP-reinforced concrete beams condition has been check both, destructively and nondestructively. The nondestructive tests foresaw vibration-based tests to obtain the natural frequency values after exposure to varying temperatures. The vibration-based tests allowed for the indirect observation of beams stiffness reduction after exposure to elevated temperature. The approach based on frequency response function (FRF) turned out to be efficient even in the case of relatively low temperatures (120⁰C). The investigation involved also destructive tests which were conducted in various conditions: once the bending load and elevated temperature were applied at the same time and in the next case, the destructive tests were conducted after heating and cooling down the experimental objects. The study proved that the increase of the temperature causes the reduction of characteristic mechanical parameters, regardless the beams were cooled down or not. However, the simultaneous action of bending load and elevated temperature resulted in a greater reduction of the ultimate strength of tested objects.

  • The Way One Defines Specification Matters: On the Performance Criteria for Efficient Antenna Optimization in Aggregated Bi-Objective Setups
    • Adrian Bekasiewicz
    • Michał Czyż
    2022 Full text

    Design of antenna structures for real-world applications is a challenging task that often involves addressing multiple design requirements at a time. Popular solution approaches to this class of problems include utilization of composite objectives. Although configuration of such functions has a significant effect on the cost and performance of the optimization, their specific structure is normally determined based on engineering experience and does not involve auxiliary investigations oriented towards adjustment of process efficiency. In this work, the effects of used functions and their composition on performance and cost of the bi-objective optimization process are investigated. The balance between the requirements is tailored to the problem at hand based on visual inspection of functional landscapes. The analyses are performed on a case study basis using a planar, multi-parameter antenna optimized for minimization of footprint and reflection within the 3.1 GHz to 10.6 GHz range. The numerical results show significant differences between the performance of the obtained solutions, as well as the computational cost of the optimization. The best geometry found using one of the considered objective functions is characterized by an in-band reflection of –9.6 dB and the footprint of only 171 mm2.

  • Theoretical designing of selenium heterocyclic non-fullerene acceptors with enhanced power conversion efficiency for organic solar cells: a DFT/TD-DFT-based prediction and understanding
    • Muhammad Khan
    • Hameed Haq
    • Saira Abbasi
    • Shan E Zehra Syeda
    • Muhammad Arshad
    2022 JOURNAL OF MOLECULAR MODELING

    In this study, we have designed and explored a new series of non-fullerene acceptors for possible applications in organic solar cells. We have designed four molecules named as APH1 to APH4 after end-capped modification of recently synthesized Y6-Se-4Cl molecule. Density functional theory and time dependent-density functional theory have been employed for computing geometric and photovoltaic parameters of the designed molecules. Designed molecules have displayed high values of fill factor and FF%. Further, high mobility of electrons and holes between metal electrodes are also noted for designed molecules. Good values of open circuit voltage enhance the power conversion efficiency in the APH1–APH4. Frontier molecular orbitals analysis and excitation energy values suggested easy transportation of charges between molecular orbitals. Moreover, red-shifting in the absorption spectrum with high oscillating strength is also noted in APH1 to APH4 as compared to reference molecules. Results of different opto-electronic and photovoltaic parameters recommended that APH1 to APH4 are effective contributors for the development of high performance organic solar cells.

  • Theoretical examination of the fracture behavior of BC3 polycrystalline nanosheets: Effect of crack size and temperature
    • Ali Dadrasi
    • Alireza Albooyeh
    • Sasan Fooladpanjeh
    • Azam Salmankhani
    • Amin Hamed Mashhadzadeh
    • Mohammad Saeb
    2022 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

    2D carbon graphene nanostructures are elements of advanced materials and systems. This theoretical survey provides explanation to the mechanical and fracture behavior of mono- and polycrystalline BC3 nanosheets (denoted as MC- and PCBC3NS, respectively) as a function of temperature and the type of crack defects. The mechanical performance of PCBC3NS at elevated temperatures was monitored varying the number of grain boundaries (the main source of stress concentration) by considering structural defects forming during the crystal growth. Molecular dynamics (MD) simulation was applied as a cost-effective technique to model and test MC- and PCBC3NS by selecting the proper potential function and boundary conditions. The results demonstrated that the mechanical properties of the perfect crystalline PCBC3NS was decreased by increase of the number of grains, particularly when the grain numbers were equal to or more than 36. For defective PCBC3NS, the mechanical properties were decreased by the crack length and the temperature. The lowest values of the Young's modulus, failure stress, and failure strain were assigned to the PCBC3NS having the crack length of L/2 at 1000 K, respectively by 23%, 46%, and 33% lower than the corresponding defect-free PCBC3NS. The crack tip played a key role in failure behavior, even more that the number of grain boundaries. Eventually, the critical stress intensity was decreased gradually by increasing the temperature. The results of this work can be generalized to more complicated cases to deepen understanding and predict fracture fingerprint of the next generations of 2D nanostructures.

  • Thermal buckling of functionally graded piezomagnetic micro- and nanobeams presenting the flexomagnetic effect
    • Mohammad Malikan
    • Tomasz Wiczenbach
    • Victor Eremeev
    2022 Full text CONTINUUM MECHANICS AND THERMODYNAMICS

    Galerkin weighted residual method (GWRM) is applied and implemented to address the axial stability and bifurcation point of a functionally graded piezomagnetic structure containing flexomagneticity in a thermal environment. The continuum specimen involves an exponential mass distributed in a heterogeneous media with a constant square cross section. The physical neutral plane is investigated to postulate functionally graded material (FGM) close to reality. Mathematical formulations concern the Timoshenko shear deformation theory. Small scale and atomic interactions are shaped as maintained by the nonlocal strain gradient elasticity approach. Since there is no bifurcation point for FGMs, whenever both boundary conditions are rotational and the neutral surface does not match the mid-plane, the clamp configuration is examined only. The fourth-order ordinary differential stability equations will be converted into the sets of algebraic ones utilizing the GWRM whose accuracy was proved before. After that, by simply solving the achieved polynomial constitutive relation, the parametric study can be started due to various predominant and overriding factors. It was found that the flexomagneticity is further visible if the ferric nanobeam is constructed by FGM technology. In addition to this, shear deformations are also efficacious to make the FM detectable.

  • Thermal cooling process by nanofluid flowing near stagnating point of expanding surface under induced magnetism force: A computational case study
    • Faisal Shahzad
    • Wasim Jamshed
    • Amjad Ali Pasha
    • Rabia Safdar
    • Md. Mottahir Alam
    • Misbah Arshad
    • Syed M. Hussain
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    2022 Full text Case Studies in Thermal Engineering

    This paper is dedicated to the exam of entropy age and research of the effect of mixing nanosolid additives over an extending sheet. In this review, Newtonian nanofluid version turned into researched at the actuated appealing field, heat radiation and variable heat conductivity results. With becoming modifications, the proven PDEs are moved into popular differential situations and paintings mathematically making use of a specific mathematical plan called the Keller box method (KBM). The ranges of different dimensionless parameters used in our study are volume fraction of nanoparticles 0.01≤ϕ≤0.04, magnetic parameter 0.5≤Λ≤2, heat source/sink parameter 0.5≤Q0≤2, Prandtl number 5.7≤Pr≤6.2, Reynolds number 5≤Re≤15, which shows up during mathematical arrangement are shown as tables and charts. Positive modifications in heat radiation and heat conductivity affects increment the hotness pass coefficient of solar primarily based totally plane wings. Titanium alloy primarily based totally water (H2O) are taken into consideration for our research. We can see that because the Reynolds range and Brinkman range increment, the entropy increments. The thermodynamic exhibition of Titanium alloy-water (Ti6Al4V- H2O) nanofluid has been portrayed higher that of base nanofluid with comparable situations. Recorded hypothetical reproductions may be greater beneficial to similarly increase daylight primarily based totally nuclear strength frameworks

  • Thermal degradation of polylactic acid (PLA)/polyhydroxybutyrate (PHB) blends: A systematic review
    • Mael Kervran
    • Christelle Vagner
    • Marianne Cochez
    • Marc Ponçot
    • Mohammad Saeb
    • Henri Vahabi
    2022 POLYMER DEGRADATION AND STABILITY

    Polylactic acid (PLA) and polyhydroxybutyrate (PHB) are two biopolyesters obtained from renewable resources like corn or sugar under bacterial fermentation. PLA is the most widely used biopolymer in diverse applications. Addition of PHB to PLA can improves the crystallinity of PLA, and thereby its mechanical strength. However, both PLA and PHB suffer from poor thermal stability, which limits their potential industrial application. The purpose of this review is to explain thermal decomposition behavior and mechanism of these polymers and systematically categorize available reports on thermal degradation of the neat PLA and PHB, and also as-processed PLA/PHB blends along with PLA/PHB blends modified/reinforced with plasticizers, additives or crosslinkers. The characteristic temperatures (Tonset, and peak temperature or Tmax) of PLA and PHB are taken as the key parameters governing thermal degradation behavior of PLA/PHB blends and composites with variable composition. From this survey we can conclude that the thermal stability of PLA in PLA/PHB blend is lower than the neat PLA, contrary to the PHB with higher thermal stability in PLA/PHB blend. Therefore, thermal degradation mechanism of PLA/PHB blends must be taken as a complex physico-chemical phenomenon. Moreover, the selection of additive severely affects the thermal stability of PLA/PHB blends. Processing method and localization of additive in different phases or at the interface of the phases are factors determining the ultimate thermal stability of blend.

  • Thermal dewetting as a method of surface modification of the gold thin films for surface plasmon resonance based sensor applications
    • Marcin Łapiński
    • Robert Kozioł
    • Agnieszka Zawadzka
    • Wojciech Sadowski
    • Barbara Kościelska
    2022 Materials Today Communications

    Here, we report a quick and simple approach with low, optimized production costs to obtain surface plasmon resonance (SPR) based sensors fabricated through a time- and resource-effective method based on thermal dewetting of thin Au films. From the applicative point of view, the method of detection presented here should be easier to implement, since light transmission measurements seem to be much less challenging than light refractive index changes measurements conducted by many authors. Metallic films with nanometric thickness were deposited by magnetron sputtering method on a Corning 1737 glass substrates. Plasmonic nanostructures were formatted as a result of thermal annealing of the films. The detection repeatability, selectivity, and sensibility of manufactured devices were investigated. For this purpose, many verification tests were performed. The quality of the plasmonic nanostructures used for the detection was examined by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and ultraviolet-visible spectroscopy (UV–VIS). X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) spectra showed the absence of any signs of structure degradation after several cycles of detection in the liquid environment. The surface plasmon resonance position of the achieved sensors was linearly changeable in correlation with the ethanol concentration, which translates into their high robustness. Such a simply prepared sensing device showed key features desired in the detection in the liquids area, which opens up the possibility of large-scale commercial production

  • Thermal Energy Development in Magnetohydrodynamic Flow Utilizing Titanium Dioxide, Copper Oxide and Aluminum Oxide Nanoparticles: Thermal Dispersion and Heat Generating Formularization
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    • Wasim Jamshed
    2022 Full text Frontiers in Energy Research

    The main aim of this article heat transfer in thermal engineering deals with the production, use, transformation, and transfer of thermal energy. Engineering and industrial fields including food packaging, the production of food additives, electronic cooling, microturbines, etc. heavily rely on heat transmission. Due to its intriguing potential in industries like the production of polymers, paper, crystal glass, etc., scientists from all over the world have endeavored to investigate the effect of heat transmission on fluid flows past an expandable surface.

  • Thermal Instability of Choline Chloride-Based Deep Eutectic Solvents and Its Influence on Their Toxicity─Important Limitations of DESs as Sustainable Materials
    • Mateusz Marchel
    • Hubert Cieśliński
    • Grzegorz Boczkaj
    2022 Full text INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

    Deep eutectic solvents (DESs) have become a hot topic in many branches of science due to their remarkable properties. They have been studied in a wide variety of applications. In particular, choline chloride (ChCl)-based DESs are one of the most commonly used representatives of these fluids. Nevertheless, in order to apply DESs in some fields, it is essential to guarantee their stability, reusability, and biocompatibility. In this context, the long-term stability of three ChCl-based DESs formed using glucose, malonic acid, and urea as hydrogen bond donors was investigated. Furthermore, the possible formation of toxic byproducts during long-term heating was evaluated for the first time, and toxicological studies using three bacterial strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) were performed. ChCl:urea DES revealed a high long-term thermal stability and was also found to be less toxic to the bacteria and thus can be considered as green solvent. ChCl:glucose DES started to decompose as a result of possible caramelization at 100 °C, and decomposition was further promoted at more elevated temperatures. Degradation of this DES did not affect greatly the toxicity toward bacteria, and low antibacterial properties were observed. The applicability of ChCl:malonic DES is not recommended as this DES was shown to be thermally unstable due to esterification and decomposition of malonic acid into acetic acid and carbon dioxide. Moreover, high toxicity of this DES in comparison to other DESs assayed in this study was reported.

  • Thermal properties of a cement composite containing phase change materials (PCMs) with post-pyrolytic char obtained from spent tyres as a carrier
    • Michał Ryms
    • Katarzyna Januszewicz
    • Elżbieta Haustein
    • Paweł Kazimierski
    • Witold Lewandowski
    2022 ENERGY

    This work examines the possible use of post-pyrolysis char made from spent vehicle tyres as a carrier for phase change materials (PCM), which could be used as an additive to cement mortar. Because of the ability of PCM to accumulate heat, the cement composite obtained from it, apart from its structural and strength properties, will acquire an additional energy storage function, which can be very important for energy-saving construction. In the development of the new cement composite, Rubitherm RT22 was used as a PCM. Rubitherm's phase change temperature is within the range (ca 17–25 °C) of temperature fluctuations in buildings. Systematic comparative tests were carried out in order to evaluate the thermal properties of the new cement composite containing 0.67, 2.00, 3.33, 4.67 and 6.67% of char, which contains 32% PCM, i.e. the maximum amount that can be permanently absorbed without activation. These tests included calorimetric measurements of the influence of the composite's composition on the cumulative specific heat, and took phase change effects into consideration. The results of the experiments showed that the use of tyre char as a PCM carrier in cement mortars is not only possible, but also thermodynamically advantageous.

  • Thermal visualization of Ostwald-de Waele liquid in wavy trapezoidal cavity: Effect of undulation and amplitude
    • Ahmad Hijaz
    • Rashid Mahmood
    • Muhammad Bilal Hafeez
    • Afraz Hussain Majeed
    • Sameh Askar
    • Hasan Shahzad
    2022 Full text Case Studies in Thermal Engineering

    The present study is concerned with the numerical simulations of Ostwald-de Waele fluid flow in a wavy trapezoidal cavity in the presence of a heated cylinder situated at the center of the cavity. The work consists in characterizing the mixed convection as a function of the intensity of heat flow. The flow behaviour and temperature distribution in a cavity are the main focus of this study. The lower wall of the cavity is fixed and heated while the wavy surface is insulated and moves with a constant speed. The sloping walls are kept cold and are subject to zero no-slip conditions for velocity components. The whole setup is modeled as a set of coupled partial differential equations and is solved by the Finite Element Method. For pressure and velocity approximations, we use the stable finite element pair , while for temperature approximation we use the space of linear polynomial as The ranges of the parameters involved in the study are the Ostwald-de Wale index , Prandlt number Grashof number , the number of undulation , and the non-dimensional amplitude of the wavy surface . The major findings of the study are shown using velocity profile, streamlines, and isotherms. Moreover, the kinetic energy and average Nusselt number is determined for various values of the parameters involved.

  • Thermally activated persulfate-based Advanced Oxidation Processes — recent progress and challenges in mineralization of persistent organic chemicals: a review
    • Shirish H. Sonawane
    • Manoj P Rayaroth
    • Vividha K. Landge
    • Kirill Fedorov
    • Grzegorz Boczkaj
    2022 Full text Current Opinion in Chemical Engineering

    Thermally 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 degradation at a high temperature of 70°C with a first-order reaction kinetics. The influence of operating parameters such as temperature, persulfate concentration, initial pH, and degradation behavior in the presence of natural water constituents are also discussed. In addition, several processes to reduce the temperature of TAP are highlighted.

  • Thermodynamic study of binary mixtures of 2-propanol with ionic liquids, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate and triethylhexylammonium bis(trifluoromethylsulfonyl)imide
    • Dorota Warmińska
    • Iwona Cichowska-Kopczyńska
    2022 JOURNAL OF CHEMICAL THERMODYNAMICS

    In this work, densities, speeds of sound, refractive indices and viscosities of three binary mixtures containing the ionic liquids 1-hexyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate and triethylhexyl-ammonium bis(trifluoromethylsulfonyl)imide, mixed with 2-propanol at wide temperature and composition ranges at atmospheric pressure have been measured. From these experimental data, the excess molar volume, excess molar compressibility, deviation in refractive index and deviation in viscosity have been calculated. Excess properties have been correlated with the composition data using Redlich-Kister polynomial equation. The effects of temperature, cation and anion of ionic liquid on the physicochemical properties were analysed and discussed in terms of intermolecular interactions occurring in the studied systems. The Prigogine-Flory-Patterson theory was examined for suitability for the correlation of excess molar volumes with compositions.

  • Thermomechanical and Fire Properties of Polyethylene-Composite-Filled Ammonium Polyphosphate and Inorganic Fillers: An Evaluation of Their Modification Efficiency
    • Mateusz Barczewski
    • Aleksander Hejna
    • Kamila Sałasińska
    • Joanna Aniśko
    • Adam Piasecki
    • Katarzyna Skórczewska
    • Jacek Andrzejewski
    2022 Full text Polymers

    The development of new polymer compositions characterized by a reduced environmental impact while lowering the price for applications in large-scale production requires the search for solutions based on the reduction in the polymer content in composites’ structure, as well as the use of fillers from sustainable sources. The study aimed to comprehensively evaluate introducing low-cost inorganic fillers, such as copper slag (CS), basalt powder (BP), and expanded vermiculite (VM), into the flame-retarded ammonium polyphosphate polyethylene composition (PE/APP). The addition of fillers (5–20 wt%) increased the stiffness and hardness of PE/APP, both at room and at elevated temperatures, which may increase the applicability range of the flame retardant polyethylene. The deterioration of composites’ tensile strength and impact strength induced by the presence of inorganic fillers compared to the unmodified polymer is described in detail. The addition of BP, CS, and VM with the simultaneous participation of APP with a total share of 40 wt% caused only a 3.1, 4.6, and 3 MPa decrease in the tensile strength compared to the reference value of 23 MPa found for PE. In turn, the cone calorimeter measurements allowed for the observation of a synergistic effect between APP and VM, reducing the peak heat rate release (pHRR) by 60% compared to unmodified PE. Incorporating fillers with a similar thermal stability but differing particle size distribution and shape led to additional information on their effectiveness in changing the properties of polyethylene. Critical examinations of changes in the mechanical and thermomechanical properties related to the structure analysis enabled the definition of the potential application perspectives analyzed in terms of burning behavior in a cone calorimetry test. Adding inorganic fillers derived from waste significantly reduces the flammability of composites with a matrix of thermoplastic polymers while increasing their sustainability and lowering their price without considerably reducing their mechanical properties, which allows for assigning developed materials as a replacement for flame-retarded polyethylene in large-scale non-loaded parts.

  • Three-Dimensional Fractography for Conventional and Additive Manufactured Steels After Bending-Torsion Fatigue
    • Wojciech Macek
    • Ricardo Branco
    • Jarosław Trembacz
    • José Domingos Costa
    • J. A. M. Ferreira
    • Carlos Capela
    2022 Structural Integrity

    In this study, fracture surface topography parameters were measured to investigate the effects of multiaxial loading. In order to assess the metrological aspects of fracture for notched specimens made of high-strength steels processed by both conventional and additively manufacturing (AM) techniques, an optical surface profilometer was used. Three bending moment to torsion moment ratios (B/T) were studied, i.e. 2, 1 and 2/3. The geometries were solid round bars with lateral notches made of conventional steel and hollow round bars with transversal holes for AM specimens. The investigations indicate that arithmetical mean height, Sa, decreased and fractal dimension, Df, increased with higher B/T ratios and higher fatigue lives.

  • Three-dimensional Weyl topology in one-dimensional photonic structures
    • Kosmas L. Tsakmakidis
    • Tomasz Stefański
    2022 Full text Light-Science & Applications

    Topological features, in particular distinct band intersections known as nodal rings, usually requiring three-dimensional structures, have now been demonstrated experimentally in an elegantly simple one-dimensional photonic crystal.

  • Time reversal invariant single-gap superconductivity with upper critical field larger than the Pauli limit in NbIr2B2
    • Debarchan Das
    • Karolina Górnicka
    • Zurab Guguchia
    • Jan Jaroszynski
    • Robert J. Cava
    • Weiwei Xie
    • Hubertus Luetkens
    • Tomasz Klimczuk
    2022 PHYSICAL REVIEW B

    Recently, compounds with noncentrosymmetric crystal structure have attracted much attention for providing a rich playground in search for unconventional superconductivity. NbIr2B2 is a new member to this class of materials harboring superconductivity below Tc = 7.3(2) K and a very high upper critical field that exceeds Pauli limit. Here we report on muon spin rotation (μSR) experiments probing the temperature and field dependence of effective magnetic penetration depth in this compound. Our transverse-field-μSR results suggest a fully gapped s-wave superconductivity. Furthermore, the estimated high value of the upper critical field is also supplemented by high-field transport measurements. Remarkably, the ratio Tc/λ−2 (0) obtained for NbIr2B2 (∼2) is comparable to those of unconventional superconductors. Zero-field μSR data reveal no significant change in the muon spin relaxation rate above and below Tc, evincing that time-reversal symmetry is preserved in the superconducting state. The presented results will stimulate theoretical investigations to obtain a microscopic understanding of the origin of superconductivity with preserved time-reversal symmetry in this unique noncentrosymmetric system.

  • Titanium lanthanum three oxides decorated magnetic graphene oxide for adsorption of lead ions from aqueous media
    • Mosleh Nazanin
    • Parham Joolaei Ahranjani
    • Parandi Ehsan
    • Hamid Rashidi Nodeh
    • Nicole Nawrot
    • Shahabaldin Rezania
    • Sathishkumar Palanivel
    2022 ENVIRONMENTAL RESEARCH

    The current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate the physical and chemical properties of the produced nanocomposites. The FeGO-TiLa was used to enhance the removal of lead ions from aqueous solution. The FeGO-TiLa nanocomposite exhibited a much higher removal efficiency (93%) for lead ions than pure TiLa nanoparticles (81%) and magnetic graphene oxide (74%). The influence of FeGO-TiLa dosage, contact time, solution pH, solution temperature, and starting quantity on the lead ions was evaluated and adjusted. The investigations demonstrated that a pH 6 with 40 mg adsorbent resulted in >91% removal of lead ions at ambient temperature after 120 min. Isotherm models were used to analyze experimental results, and Langmuir model fitted the data well as compared Freundlich model with a maximum adsorption capacity of 109.89 mg g−1. Kinetic and studies are performed the lead adsorption over FeGO-TiLa follow pseudo-second-order rate. Langmuir and Free energy suggested the lead ions uptake with FeGO-TiLa was monolayer and physical adsorption mechnaism, respectively. Finally, the FeGO-TiLa nanocompoiste can be used as an alternative adsorbent for water remediation.

  • Ti/TiO2 nanotubes sensitized PbS quantum dots as photoelectrodes applied for decomposition of anticancer drugs under simulated solar energy
    • Paweł Mazierski
    • Patrycja Wilczewska
    • Wojciech Lisowski
    • Tomasz Klimczuk
    • Anna Białk-Bielińska
    • Adriana Zaleska-Medyska
    • Ewa Siedlecka
    • Aleksandra Pieczyńska
    2022 Full text JOURNAL OF HAZARDOUS MATERIALS

    One of the challenges in research into photoelectrocatalytic (PEC) degradation of pollutants is finding the appropriate photoanode material, which has a significant impact on the process efficiency. Among all others, photoelectrodes based on an ordered TiO2 nanotube arrays are a promising material due to well-developed surface area and efficient charge separation. To increase the PEC activity of this material, the SILAR method was used to decorate Ti/TiO2 nanotubes by PbS quantum dots (QD). The ifosfamide (IF) degradation rate constants was twice as higher for PbS-Ti/TiO2 (0.0148 min 1) than for Ti/TiO2 (0.0072 min 1). Our research showed the highest efficiency of PEC degradation of drugs using IIIPbS-Ti/TiO2 made with 3 SILAR cycles (PbS QD size mainly 2–4 nm). The 4 and 6 of SILAR cycles resulted in the aggregation of PbS nanoparticles on the Ti/ TiO2 surface and decreased IF PEC degradation rate to 0.0043 and 0.0033 min 1, respectively. Research on PEC mechanism has shown that the drugs are degraded mainly by the activity of photogenerated holes and hydroxyl radicals. In addition, the identified drug intermediates made possible to propose a degradation pathways of anticancer drugs and the ecotoxicity test show no inhibition of Lemna minor growth of treated solutions.

  • Tolerance Optimization of Antenna Structures by Means of Response Feature Surrogates
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Fabrication tolerances and other types of uncertainties, e.g., the lack of precise knowledge of material parameters, have detrimental effects on electrical and field performance of antenna systems. In the case of input characteristics these are particularly noticeable for narrow- and multi-band antennas where deviations of geometry parameters from their nominal values lead to frequency shifts of the operating frequency bands. Improving design robustness is therefore important yet challenging. On the one hand, it is numerically demanding as it involves uncertainty quantification (UQ), in particular, estimation and improvement of appropriately defined statistical performance metrics. On the other hand, it has to be carried out at the level of full-wave electromagnetic (EM) simulation models, which incurs considerable computational expenses. Executing UQ tasks at practically acceptable costs can be realized using surrogate modeling methods; however, construction of reliable metamodels is hindered by the curse of dimensionality. This paper proposes a novel approach to robust design of antenna structures, where the task is formulated to increase the maximum values of parameter deviations for which 100-percent fabrication yield is ensured. Low cost of the optimization process is enabled by incorporating feature-based regression models for rapid yield estimation, as well as the employment of the trust-region framework for adaptive adjustment of design relocation but also as a convergence safeguard. Our methodology is validated using three microstrip antennas, including two dual-band and a triple-band structure.

  • Tolerance-Aware Multi-Objective Optimization of Antennas by Means of Feature-Based Regression Surrogates
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 Full text IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Assessing the immunity of antenna design to fabrication tolerances is an important consideration, especially when the manufacturing process has not been predetermined. At the same time, the antenna parameter tuning should be oriented toward improving the performance figures pertinent to both electrical (e.g., input matching) and field properties (e.g., axial ratio bandwidth) as much as possible. Identification of available trade-offs between the robustness and nominal performance can be realized through multi-objective optimization (MO), which is an intricate and computationally expensive task. This paper proposes a novel technique for fast tolerance-aware MO of antenna structures. The key component of the presented methodology is a feature-based regression surrogate, established based on the characteristic points of antenna responses extracted from its electromagnetic (EM)-simulation data, and employed for a rapid estimation of the maximum allowed input tolerance levels for given values of performance parameters of interest. Subsequent trade-off designs are generated by tuning the antenna parameters for various assumed values of relevant figures of interest (e.g., the operating bandwidth). As demonstrated using three microstrip antennas, a rendition of performance-robustness trade-off designs can be accomplished at the cost of just about forty (for six-parameter antenna) to about eighty (for fourteen-parameter antenna) per design EM analyses of the respective structure. Reliability of the approach is validated through direct EM-driven Monte Carlo analysis at the selected designs.

  • Tolerance-Aware Optimization of Microwave Circuits by Means of Principal Directions and Domain-Restricted Metamodels
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Ullah Ubaid
    2022 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    Practical microwave design is most often carried out in the nominal sense. Yet, in some cases, performance degradation due to uncertainties may lead to the system failing to meet the prescribed specifications. Reliable uncertainty quantification (UQ) is therefore important yet intricate from numerical standpoint, especially when the circuit at hand is to be evaluated using electromagnetic (EM) simulation tools. Tolerance-aware design (e.g., yield improvement) is even more challenging. This paper introduces a methodology for low-cost surrogate-based yield optimization of passive microwave components. The novelty of the proposed approach, and, at the same time, its major acceleration factor is to span the metamodel model domain with the selected principal vectors, characterized by significant response variability within operating frequency bands of the component under design. This results in a volume-wise constriction of the domain (thereby lower cost of the surrogate model setup) without restricting its size along the relevant directions of the parameter space. Consequently, our technique is a one-shot approach for yield optimization that does not require neither domain relocation nor surrogate re-construction. Our methodology is demonstrated using two microstrip components, and favorably compared to benchmark metamodeling techniques in terms of the computational cost of the yield maximization procedure. The average cost is only 130 EM simulations of the respective circuit, versus the average of 800 and over 360 analyses for the benchmark procedures. At the same time, its reliability is verified by means of EM-based Monte Carlo simulation.

  • Tool Wear Monitoring Using Improved Dragonfly Optimization Algorithm and Deep Belief Network
    • Leo Gertrude David
    • Raj Kumar Patra
    • Przemysław Falkowski-Gilski
    • Parameshachari Bidare Divakarachari
    • Lourdusamy Jegan Antony Marcilin
    2022 Full text Applied Sciences-Basel

    In recent decades, tool wear monitoring has played a crucial role in the improvement of industrial production quality and efficiency. In the machining process, it is important to predict both tool cost and life, and to reduce the equipment downtime. The conventional methods need enormous quantities of human resources and expert skills to achieve precise tool wear information. To automatically identify the tool wear types, deep learning models are extensively used in the existing studies. In this manuscript, a new model is proposed for the effective classification of both serviceable and worn cutting edges. Initially, a dataset is chosen for experimental analysis that includes 254 images of edge profile cutting heads; then, circular Hough transform, canny edge detector, and standard Hough transform are used to segment 577 cutting edge images, where 276 images are disposable and 301 are functional. Furthermore, feature extraction is carried out on the segmented images utilizing Local Binary Pattern (LBPs) and Speeded up Robust Features (SURF), Harris Corner Detection (HCD), Histogram of Oriented Gradients (HOG), and Grey-Level Co-occurrence Matrix (GLCM) feature descriptors for extracting the texture feature vectors. Next, the dimension of the extracted features is reduced by an Improved Dragonfly Optimization Algorithm (IDOA) that lowers the computational complexity and running time of the Deep Belief Network (DBN), while classifying the serviceable and worn cutting edges. The experimental evaluations showed that the IDOA-DBN model attained 98.83% accuracy on the patch configuration of full edge division, which is superior to the existing deep learning models.

  • Topical delivery of pharmaceutical and cosmetic macromolecules using microemulsion systems
    • Patrycja Szumała
    • Adam Macierzanka
    2022 INTERNATIONAL JOURNAL OF PHARMACEUTICS

    Microemulsions are transparent, thermodynamically stable colloidal systems. Over the recent years, they have been increasingly investigated due to their potential as skin delivery vehicles for a wide range of drug molecules. The nanoscale particle size and the specificity of microemulsion components are the main features determining the skin permeation process. However, in order to effectively cross the skin barrier, the active substance itself should also meet a number of requirements, such as relatively small molecular weight, high lipophilicity with certain polarity as well as a specific partition coefficient. This review focuses on recent advancements in topical microemulsion systems related to the transport of active ingredients into the skin, including those with high molecular weight and high polarity. Selected studies have shown that permeation of therapeutic macromolecules can be increased by the correct (i.e. tailored to a specific drug) design of the microemulsion. The degree of skin penetration as well as the kinetics and the site of drug release can be controlled by appropriate qualitative and quantitative selections of penetration promoters (microemulsion components), the structure of microemulsion and its viscosity. The drug-carrier interactions can also affect the effectiveness of microemulsion formulation. These relations have been described and evaluated in this review article.

  • Topochemical, Single‐Crystal‐to‐Single‐Crystal [2+2] Photocycloadditions Driven by Chalcogen‐Bonding Interactions
    • Jan Alfuth
    • Olivier Jeannin
    • Marc Fourmigué
    2022 Full text ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

    The face-to-face association of (E)-1,2-di(4-pyridyl)ethylene (bpen) molecules into rectangular motifs stabilized for the first time by chalcogen bonding (ChB) interactions is shown to provide photoreactive systems leading to cyclobutane formation through single-crystal-to-single-crystal [2+2] photodimerizations. The chelating chalcogen bond donors are based on original aromatic, ortho-substituted bis(selenocyanato)benzene derivatives 1–3, prepared from ortho-diboronic acid bis(pinacol) ester precursors and SeO2 and malononitrile in 75–90% yield. The very short intramolecular Se···Se distance in 1–3 (3.22–3.24 Å), a consequence of a strong intramolecular ChB interaction, expands to 3.52–3.54 Å in the chalcogen-bonded adducts with bpen, a distance (< 4 Å) well adapted to the face-to-face association of the bpen molecules into reactive position toward photochemical dimerization.

  • Topological extraordinary optical transmission
    • Konstantinos Baskourelos
    • O. Tsilipakos
    • Tomasz Stefański
    • S. F. Galata
    • E. N. Economou
    • M. Kafesaki
    • Kosmas L. Tsakmakidis
    2022 Full text Physical Review Research

    Τhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 10^4-10^5 or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at its end. Specifically, for a slit width of just λeff/72 (λ0/138) the attained normalized transmission coefficient reaches a value of 1.52, while for a unidirectional-only (nontopological) device the normalized transmission through a λeff/21 (∼λ0/107) slit reaches 1.14; both limited only by inherent material losses, and with zero reflection from the slit. The associated, under ideal (ultralow-loss) conditions, near-perfect optical extraordinary transmission has implications, among diverse areas in wave physics and engineering, for high-efficiency, maximum-throughput nanoscopes and heat-assisted magnetic recording devices.

  • TOTAL CROSS SECTION MEASUREMENTS FOR ELECTRON SCATTERING ON METHYL FORMATE (HCOOCH3) MOLECULE: METHYLATION EFFECT
    • Natalia Tańska
    • Kuba Wójcik
    • Sylwia Dylnicka
    • Elżbieta Ptasińska-Denga
    • Czesław Szmytkowski
    • Paweł Możejko
    2022 Full text PUBLICATIONS OF THE ASTRONOMICAL OBSERVATORY OF BELGRADE

    We present the absolute total cross section (TCS) for electron scattering from the methyl formate (HCOOCH3) molecule measured in the 10-300 eV energy range, with electrostatic electron spectrometer working in the linear transmission mode. Comparison of TCS for the HCOOCH3 molecule with that measured earlier for the formic acid (HCOOH) compound manifests the methylation effect i.e. the response of the electron scattering dynamics on replacing of the hydrogen atom in the hydroxy group in HCOOH with the methyl group (-CH3). It is also shown that the TCS for methyl formate can be estimated with simple additivity rule, using TCSs for the formic acid, ethane and hydrogen molecules. The energy dependence of determined this way TCS for HCOOCH3 and the measured values are in very good agreement above 20 eV.

  • Total mercury and methylmercury (MeHg) in braised and crude Boletus edulis carpophores during various developmental stages
    • Jerzy Falandysz
    • Martyna Saba
    • Małgorzata Rutkowska
    • Piotr Konieczka
    2022 Full text ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    We collected and processed Boletus edulis (King Bolete) carpophores grouped in four batches based on their developmental stage (button stage, young—white, large—white, and large—yellow). The study aimed, for the first time, to examine the B. edulis content and effect of braising and to estimate the intake of total mercury (THg) and methylmercury (MeHg) from a single meal based on whole (wet) weight (ww) and dry weight (dw). In braised carpophores, THg concentrations ranged from 0.2668 ± 0.0090 to 0.5434 ± 0.0071 mg kg−1 ww at different developmental stages, whereas crude products concentrations ranged from 0.1880 ± 0.0247 to 0.2929 ± 0.0030 mg kg−1 ww. The button stage crude carpophores were more highly contaminated with THg than at later stages of maturity, but MeHg levels were lower (p < 0.0001). On the other hand, braised button stage carpophores showed more MeHg than at later maturity stages. MeHg contributed at 1.9 ± 0.7% in THg in crude mushrooms and at 1.4 ± 0.3% in braised meals. The effect of braising was to increase the average THg and MeHg contents in fresh mushroom meals by 52 ± 31% and 53 ± 122% respectively, but a reduction of 40 ±14% and 40 ± 49% respectively was seen on a dw basis. The potential intakes of THg and MeHg from braised meals of B. edulis studied were small and considered safe.

  • Toward a unified model of mobile Business Intelligence (m-BI) acceptance and use
    • Paweł Weichbroth
    • Jolanta Kowal
    • Mateusz Kalinowski
    2022 Full text

    Factors affecting mobile business intelligence (m-BI) acceptance and use have become an increasingly important topic in practice due to the growing complexity of organizations, and their underlying information systems (IS). Since, one can notice considerable interest in m-BI, however, to the best of our knowledge few studies (if any) aim to synthesize the existing body of knowledge with regards to the factors affecting m-BI acceptance and use. To fill this gap, we conducted a systematic literature review and summarized the current state of the art. By addressing research questions, we identified a set of five factors, namely: Perceived Value, Perceived Ease of Use, Managerial Attitudes, Facilitating Conditions and Quality of Information, and specified their inter-relationships. Moreover, we introduce an acceptance model (m-BIAM) on behavioral intention and use mobile Business Intelligence solutions. The contribution of this study lies in these evidence-based findings, which lay a solid foundation for further studies in the extent of testing and evaluating the m-BIAM model, targeted at delivering more evidence to confirm its validity and predictive power.

  • Towards an Understanding of the Stability Assessment of Floating Buildings
    • Artur Karczewski
    2022

    One of the most important aspects of the design of floating facilities such as ships, floating offshore structures or floating houses is stability. Its impact on both general safety and operational aspects renders it a fundamental consideration already in preliminary design stages. Usually, the concept of sufficient stability of floating buildings is associated with the ability to keep an allowed heel angle and residual freeboard, despite the action of the heeling moment. Once in the water, a floating object has to withstand different environmental conditions. It is always acted upon by forces from various factors. The main sources of load are wind, waves and the shift of inhabitants. However, the challenges in the assessment of stability are also connected to how a floating structure responds to these sources of load and also to the method of performing a stability analysis. This paper focuses on wind load and revisits several challenges encountered in the stability calculations and in the prediction of the behavior of floating buildings. A review of the current regulations was also performed in this respect. The obtained results indicate the necessity and also direction of further considerations related to the safety of stationary floating objects.

  • Towards application of uncertainty quantification procedure combined with experimental procedure for assessment of the accuracy of the DEM approach dedicated for granular flow modeling
    • Agata Widuch
    • Marcin Nowak
    • Dawid Sukiennik
    • Kari Myöhänen
    • Markku Nikku
    • Srujal Shah
    • Alessandro Parente
    • Wojciech Adamczyk
    2022 POWDER TECHNOLOGY

    There is a high demand for accurate and fast numerical models for dense granular flows found in many industrial applications. Nevertheless, before numerical model can be used its need to be always validated against experimental data. During the validation, it is important to consider how the measurement data sets, as well as the numerical models, are affected by errors and uncertainties. In this study, the uncertainty quantification for the Discrete Element Method (DEM) model was performed based on selected quantities of interest (QOI), which were measured at a test rig. The uncertainty quantification was performed with open-source Dakota code, and the Latin hypercube sampling technique was used to determine test points. Various correlations between the input and output data were investigated to assess the impact of the possible input data errors on the output values determined by the solver. The results were validated against the measurement data from a novel in-house experimental test rig. The novel character of this work is developed procedure for study the impact of the uncertainties related with the input data on numerical results delivered by DEM model. In-house algorithm written using OpenCV libraries for determining particle motion characteristics from image dataset was used for results determination and postprocessing.

  • Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
    • Roberto Castro-Muñoz
    • Asma Msahel
    • Francesco Galiano
    • Marcin Serocki
    • Jacek Ryl
    • Sofiane Ben Hamouda
    • Amor Hafiane
    • Grzegorz Boczkaj
    • Alberto Figoli
    2022 Full text SEPARATION AND PURIFICATION TECHNOLOGY

    Deep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes using chitosan (CS) as a polymer phase. The compatibility among both phases (polymer and DESs) and their ability to form homogenous membranes was preliminary studied. In this regard, scanning electron and confocal microscopies were used to completely map the structure of the resulting membranes evidencing a complete homogenous structure. The membranes were also characterized in terms of contact angle (CA), Fourier transformed infrared spectroscopy (FTIR), mechanical resistance and swelling degree (uptake). Preliminary pervaporation tests for the separation of a methanol (MeOH)- methyl tert-butyl ether (MTBE) azeotropic mixture were, thus, performed. In this regard, the addition of DESs provided an enhanced separation efficiency in comparison to pristine CS membranes. Thanks to the morphology and properties exhibited, the newly developed membranes can be considered as excellent bio-based candidates to be explored in other gas selective and solvent oriented membrane operations.

  • Towards Carbon Neutral Settlements. The Importance of Early-Stage Urban and Energetic Optimizations
    • Justyna Martyniuk-Pęczek
    • Julia Kurek
    • Justyna Borucka
    2022 Full text ACE-Architecture City and Environment

    The aim of the research was to verify the essence of interdisciplinary energy optimizations in earlystage urban design process. A further aim was to the find most optimal design variant and scenario in terms of urban energy efficiency for the future development in Nowy Port, located in Gdansk, Poland - a place requiring complex revitalization. The research combined qualitative and quantitative approaches; an urban design layer (architectural analysis of spatial systems and planning) and an energy layer (simulations). For energy and environmental simulations, the ELAS calculator was used in an innovative way, that enabled comparison of results of several projects in terms of energy demand, carbon dioxide lifecycle emissions and ecological footprint for different urban layouts. The innovative method including the application of ELAS tool in early-stage design phase proved to be relevant and allowed for an appropriate pre-assessment and comparison of urban energy efficiency parameters and life cycle analysis at an initial stage of the project. One of the key conclusions is that the design variant with the highest building density was not the most advantageous in terms of low environmental impact and energy demand. In addition, the research demonstrated that the individual behavior of residents, their mobility patterns and the energy systems are more important than the improvements focused only on building energy performance.

  • Towards classification of patients based on surface EMG data of temporomandibular joint muscles using self-organising maps
    • Mateusz Troka
    • Wiktoria Wojnicz
    • Katarzyna Szepietowska
    • Marek Podlasiński
    • Sebastian Walerzak
    • Konrad Walerzak
    • Izabela Lubowiecka
    2022 Full text Biomedical Signal Processing and Control

    The study considers the need for an effective method of classification of patients with a temporomandibular joint disorder (TMD). The self-organising map method (SOM) was applied to group patients and used together with the cross-correlation approach to interpret the processed (rectified and smoothed by using root mean square (RMS) algorithm) surface electromyography signal (sEMG) obtained from testing the muscles (two temporal muscles and two masseters) of the temporomandibular joint (TMJ) during selected jaw movements. SOM’s Unified distance matrix (U-matrix) maps consist of formed clusters that correspond to similarities in input datasets. The results showed that SOM was able to encode muscular responses and create clusters. Information about the level of similarity between the activity of right, left, ipsilateral, and contralateral pairs of muscles was provided by intra cross-correlation coefficient (CC). A low intra CC value may indicate instability of the TMJ function. Information about the level of similarity between the sEMG signals of the same muscles tested in two different patients was provided by inter CC. SOM analysis can be used to interpret the activation of muscular systems, and by comparing the results of different individuals also to identify their TMJ health. Using the cross-correlation approach, one can find similarities in the sEMG data of different patients that can be used to provide clinically useful information. Such findings could be used to improve the clinical diagnosis of TMD and assess muscle activity during treatment.

  • Towards Designing an Innovative Industrial Fan: Developing Regression and Neural Models Based on Remote Mass Measurements
    • Jacek Czyżewicz
    • Piotr Jaskólski
    • Paweł Ziemiański
    • Marian Piwowarski
    • Mateusz Bortkiewicz
    • Krzysztof Laszuk
    • Ireneusz Galara
    • Marta Pawłowska
    • Karol Cybulski
    2022 Full text ENERGIES

    This article presents the process of the construction and testing a remote, fully autonomous system for measuring the operational parameters of fans. The measurement results obtained made it possible to create and verify mathematical models using linear regression and neural networks. The process was implemented as part of the first stage of an innovative project. The article presents detailed steps of constructing a system to collect and process measurement data from fans installed in actual operating conditions and the results of analysis of this data. In particular, a measurement infrastructure was developed, defined, and implemented. Measuring equipment was mounted on selected ventilation systems with relevant fans. Systems were implemented that allowed continuous measurement of ventilation system parameters and remote transmission of data to a server where it was regularly analysed and selected for use in the process of modelling and diagnostics. Pearson’s correlation analysis for p < 0.05 indicated that all seven parameters (suction temperature, discharge temperature, suction pressure, current consumption, rotational speed, humidity, and flow) were significantly correlated with efficiency (p < 0.001). A satisfactory level of correlation between the selected parameters measured in actual conditions and the characteristics of the fan and the ventilation system was experimentally verified. This was determined by finding 4 statistically significant parameters at a confidence level of 95%. This allowed the creation of two mathematical models of the fan system and the ventilation system using linear regression and neural networks. The linear regression model showed that the suction temperature, discharge temperature, and air humidity did not affect the fan efficiency (they are statistically insignificant, p > 0.05). The neural model, which considered all measured parameters, achieved the same accuracy as the model based on four significant parameters: suction pressure, current consumption, rotational speed, and flow.

  • Towards evaluation of the Second Generation Intact Stability Criteria - examination of a fishing vessel vulnerability to surf-riding, based on historical capsizing
    • Zbigniew Szozda
    • Przemysław Krata
    2022 OCEAN ENGINEERING

    The Second Generation Intact Stability Criteria (SGISC) are the latest achievements in the field of intact ship stability assessment. The criteria are the result of massive international cooperative efforts and extensive research that lasted more than 15 years. Even though they are based on a solid scientific foundation, the trial period has commenced to collect user experience and further validation. One of possible approaches to evaluation of the credibility of the criteria is to demonstrate that ships which capsized in the past due to a stability failure are identified by the criteria as being vulnerable to that specific stability failure mode. The approach combines a critical analysis of the actual accident and calculations that follow procedures provided by the SGISC framework on Level 1 and Level 2. Such approach was applied to a historical catastrophe of a ship regarding the surf-riding stability failure mode. Polish flag fishing vessel m/t Cyranka, which capsized in the North Sea, has been examined for her vulnerability to the surf-riding/broaching-to phenomenon. The analysis shows that the vulnerability criteria related to surf-riding phenomenon can identify the observed vulnerability of the ship. This study contributes to the recognition of the new criteria as being reliable regarding the surf-riding. The proposed approach can be adopted for the evaluation of any stability failure mode covered by the SGISC.

  • Towards Knowledge Sharing Oriented Adaptive Control
    • Guixian Li
    • Yufeng Xu
    • Haoxi Zhang
    • Edward Szczerbicki
    2022 Full text CYBERNETICS AND SYSTEMS

    In this paper, we propose a knowledge sharing oriented approach to enable a robot to reuse other robots' knowledge by adapting itself to the inverse dynamics model of the knowledge-sharing robot. The purpose of this work is to remove the heavy fine-tuning procedure required before using a new robot for a task via reusing other robots' knowledge. We use the Neural Knowledge DNA (NK-DNA) to help robots gain empirical knowledge and introduce a Knowledge Adaption Module (KAM) utilizing the deep neural networks (DNN) for knowledge reuse. The initial experiment shows that the target robot can adapt to the inverse dynamic model of the source robot via our KAM and reuse the knowledge shared by the source robot.

  • Towards Open Research Data in the Economics Discipline
    • Piotr Kasprzak
    • Magdalena Szuflita-Żurawska
    2022 Full text

    Nowadays, Open Research Data, as one of the three pillars of Open Science (along with Open Access and Open Scholarly Communication), is gaining enormous attention from different academic and commercial environments. A wide range of scientific disciplines represent and produce different types of data and at the same time, gather different issues and problems in terms of sharing and dissemination research output. This chapter aims to briefly describe the current state of the scientific data for the business and economics disciplines. It presents the opportunities and concerns in those particular scientific fields where very often conducting research is supported not only by public funds but also by business and industry providers. Specific data types (such as financial data) need a particular approach to maintain them, especially in terms of the licensing, preservation and sharing openly. Their proper management can have a significant impact on the knowledge-based economy.

  • Towards spectral sensitivity curve for two-photon vision mechanism
    • Marcin Marzejon
    • Zielińska Agnieszka
    • Dorota Stachowiak
    • Grzegorz Soboń
    • Maciej Wojtkowski
    • Komar Katarzyna
    2022

    Abstract Purpose: The perceived brightness of different visible light sources can be compared with photometric units based on the standardized luminosity curves (300-780nm range). As reported previously (PNAS 111(50), pp. E5445-E5454 (2014)), near-infrared (NIR) radiation can cause isomerization of visual pigments by one- or two-photon absorption. The perceived color of the stimulus is red in the case of one-photon vision (1PV) or corresponds to half of the short-pulsed laser wavelength for the two-photon vision (2PV) mechanism. Since no luminosity curves for NIR range, comparison of such sources with photometric units is impossible. This study aims to provide an initial data for the 2PV spectral sensitivity curve (SSC). Methods: We measured the scotopic visibility thresholds at fovea for 4 healthy dark-adapted subjects (2 males, 2 females; 27-43 y/o) between 750-1075nm. Up to 930nm, the total visibility threshold corresponds only to 1PV mechanism. For the 810-930nm, subjects distinguished 2 thresholds: the loss of half of the wavelength hue (2PV threshold) and total visibility (1PV) threshold. Starting from 950nm, only 2PV mechanism caused the visual sensation. The stimulus was a 0.5 deg diameter flickering circle projected in the retina by scanners. Two tunable pulsed light sources: OPO (750-990nm, Frep=76MHz, τp=204fs) and fiber laser (872-1075nm, Frep=51.5MHz, τp=205±9fs) were employed for psychophysical tests. The study complied with the Declaration of Helsinki and was approved by the Ethics Committee of the Collegium Medicum, NCU. Results: The 1PV thresholds agreed with the previous works (JOSA 37(7), pp. 546-554 (1947)). Within the 810-930nm range, a relatively high standard deviation of the 2PV thresholds was observed, as finding the disappearance of half of the wavelength hue is a relatively difficult task. 2PV thresholds slightly differ for OPO and fiber laser, which is explainable by differences in pulse durations and repetition rates. For ~1040nm, the 2PV threshold values agreed to the previous authors’ results. Conclusions: The 2PV sensitivity increased with wavelength of about 1 order of magnitude (810-1075nm range). Starting from 1010 nm, the shape of the obtained 2PV SSC differs from the wavelength-doubled scotopic luminosity curve for 1PV, corrected by the eye media transmittance. The maximum of 2PV SSC was not found. The results allowed us to obtain the first approximation of the 2PV SCC shape up to 1075nm.

  • Towards spectroscopic monitoring of photoelectrodes: In-situ Raman photoelectrochemistry of a TiO2/prussian blue photoanode
    • Konrad Trzciński
    • Mariusz Szkoda
    • Zuzanna Zarach
    • Mirosław Sawczak
    • Andrzej Nowak
    2022 ELECTROCHIMICA ACTA

    Here, novel in-situ Raman photoelectrochemical measurements are performed. The obtained results have proved that it is possible to track the progress of a photoelectrochemical reaction that takes place on a semiconducting electrode using the spectroscopic method. As an exemplary system, the Ti/TiO2/Prussian blue electrode is investigated. Since TiO2 is an n-type semiconductor, it cannot act as an efficient anode in dark conditions. Thus, once electrochemically reduced Prussian blue deposited on TiO2 is not reoxi- dized during anodic polarization. However, Everitt’s salt oxidation may be possible when photoexcitation of TiO2 with UV LED radiation takes place at a potential which is more anodic than the flat band poten- tial of the semiconductor. This process is successfully monitored in-situ using Raman spectroscopy. The measurements performed at different conditions allow to distinguish between processes induced by po- larization and illumination (or both). The proposed method of photoelectrode characterization through a real-time monitoring approach can be further developed and utilized for other photoelectrochemical systems.

  • Training of Deep Learning Models Using Synthetic Datasets
    • Zdzisław Kowalczuk
    • Jan Glinko
    2022

    In order to solve increasingly complex problems, the complexity of Deep Neural Networks also needs to be constantly increased, and therefore training such networks requires more and more data. Unfortunately, obtaining such massive real world training data to optimize neural networks parameters is a challenging and time-consuming task. To solve this problem, we propose an easy-touse and general approach to training deep learning models for object detection and instance segmentation without being involved in the generation of real world datasets. In principle, we generate and annotate images with open-source software and 3D models that mimic real life objects. This approach allows us significantly reduce the effort required to gather pictures as well as automatize data tagging. It is worth noting that such synthetic datasets can be easily manipulated, e.g. to reduce the texture bias that often occurs in the resulting trained convolutional networks. Using the Mask R-CNN instance segmentation model as an example, we demonstrate that a network trained on the synthetic dataset of kitchen facilities shows remarkable performance on the validation dataset of real-world human-annotated photos. We show that our approach helps to bridge the domain gap between pre-trained models and their specific applications. In summary, such synthetic datasets help overcome the problem of acquiring and tagging thousands of images, while reducing the time and labor costs associated with the preparation of an appropriate real dataset

  • Transformation of Energy Markets: Description, Modeling of Functioning Mechanisms and Determining Development Trends
    • Michał Pietrzak
    • Marta Kuc-Czarnecka
    2022 Full text ENERGIES

    One of the key contemporary economic and social issues today is the global energy transition. Energy transition processes are having a significant impact on the development of world economies, increasing their TFP and leading to an increase in their level of innovation through the transfer of myriad new technologies. These processes also contribute to an increase in foreign direct investment and, consequently, an increase in the level of business investment, the competitiveness of economies and changes in the labor market. Additionally, contributing to the systematic and dynamic development of the energy transition are the significant increase in the wealth of the population, the change in the degree of social and income inequality, the change in consumption patterns and the significantly increased consumption of energy by households, which until re-cently relied exclusively on the use of energy from conventional sources. It should be noted that the ongoing energy transition processes most strongly affect the development of energy markets, the largest of which are the electricity primary fuel markets. Currently, energy markets represent an increasingly significant aspect of modern economies in terms of business investment, the share of the sector’s output in GDP, as well as research and development. In recent years, the renewable energy sector has also been gaining importance as a natural complement to the two aforementioned markets. All the above-mentioned aspects of the development of modern economies point to the need to take a fresh look at the development and functioning of energy markets. Of particular importance seems to be the analysis of changes in the prices of electricity and primary fuels and the relationship between these markets and the renewable energy mar-ket. Equally important are analyses to identify development trends already occurring in the energy markets and to make predictions about the formation of these trends in the fu-ture. Such identified studies should provide valuable guidance for the purposes of con-ducting current energy policy and creating institutional and legal conditions for the development of energy markets. Conclusions from research on energy markets also provide substantive arguments for the assumptions of global energy strategies, as well as the energy strategy of individual countries.

  • Transformational Leadership and Acceptance of Mistakes as a Source of Learning: Poland-USA Cross-Country Study
    • Wioleta Kucharska
    • Maciej Kucharski
    • Hafeez Ur Rehman
    2022 Full text

    This study explores the influence of transformational leadership on internal innovativeness mediated by mistakes acceptance, including country and industry as factors to be considered and gender and risk-taking attitude as moderators. General findings, primarily based on the US samples (healthcare, construction, and IT industry), confirmed that transformational leadership and internal innovativeness are mediated by mistakes acceptance and strengthened by employees' risk-taking attitude. It is reflected in the Polish healthcare sample. On the other hand, IT and construction industry samples revealed that a low mistakes acceptance level among risk-taking managers under transformational leadership might be their hidden form of change resistance. Regarding gender issue, this study showed that male employees driven by transformational leaders accept mistakes as a source of learning better than women, but the exceptions are healthcare and IT industries in Poland. The developed empirical model is based on a sample composed of 2,160 Polish and American knowledge workers applying OLS regression using SPSS PROCESS macro software.

  • Transformational leadership for researcher’s innovativeness in the context of tacit knowledge and change adaptability
    • Wioleta Kucharska
    • Teresa Rebelo
    2022 Full text International Journal of Leadership in Education

    This study explores how a learning culture supported by transformational leadership influences tacit knowledge sharing and change adaptability in higher education and how these relations impact this sector’s internal and external innovativeness. The empirical model was tested on a sample of 368 Polish scientific staff using the structural equation modeling (SEM) method. Then results were expanded by applying OLS regression using SPSS PROCESS macro. Findings revealed that tacit knowledge sharing and change adaptability driven by learning culture are vital links connecting transformational leadership with innovativeness. Moreover, change adaptability was revealed to be a critical factor mediating between tacit knowledge sharing and innovativeness (external and internal). Tacit knowledge sharing and transformational leadership are seen as fully mediated by the mistake acceptance factor in learning culture. Besides, this study provided empirical evidence that higher education institutions must adapt to change constantly and evaluate their internal processes to deliver a higher level of innovative work visible externally. It also shows that leaders supporting a smooth flow of tacit knowledge sharing are central to scientific development because they foster adaptability and innovativeness (external and internal). Furthermore, the influence of the mistakes acceptance component on tacit knowledge sharing is revealed to be moderated by gender.