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  • Matrix Strengthening the Identification of Observations with Split Functional Models in the Squared Msplit(q) Estimation Process
    • Marek Zienkiewicz
    • Pawel S. Dąbrowski
    2023 MEASUREMENT

    This article addresses the issue of raising the level of identification of observations with either single or more split functional models in the squared Msplit(q) estimation process. The theoretical part of the study presents the theoretical grounds for the classical method for estimating parameters in a split functional model and proposes a modification of the computational algorithm to increase the quality of the determinations obtained. Theoretical considerations were verified through numerical tests concerning, e.g. issues of geodetic surveying practice and civil engineering.

  • Maximum transportation growth in energy and solute particles in Prandtl martial across a vertical 3D-heated surface: Simulations achieved using by finite element approach
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    • Wasim Jamshed
    2023 Pełny tekst COMPUTERS & MATHEMATICS WITH APPLICATIONS

    The goal of this study is to determine the maximum energy and solute particles' transportation growth in a 3D-heated region of Prandtl martial through a dynamic magnetic field. The effects of this field on the properties of solvent molecules and heat conduction are studied. A correctly stated functional method and a finite element approach are comparable to a certain type of differential equations. In order demonstrate the effects of various factors such as mass diffusion, heat generation, and thermal diffusivity on the investigation of the diffusion coefficient and thermal mass in a three-dimensional Newtonian flow, the study of viscous and heat conduction rates is presented. The results show that the comparisons of hybrid nanofluid and with base fluid and w.r.t Local skin friction coefficient, Nusselt number and Sherwood number.

  • M-BDC (M = Co and/ or Fe) MOFs as effective catalysts for hydrogen generation via hydrolysis of sodium borohydride
    • Maria Alaide de Oliveira
    • Elibe Silva Souza
    • Jildimara de Jesus Santana
    • Natalia Łukasik
    • Bárbara Stefany Lima da Silva
    • Bráulio Silva Barros
    • Joanna Kulesza
    2023 APPLIED SURFACE SCIENCE

    Mono- (Co-BDC, Fe-BDC) and bimetallic FeCo-BDC Metal-Organic Frameworks are successfully synthesized by the solvothermal method in DMF at 150 °C within 15 h and tested as catalysts for sodium borohydride hydrolysis. The materials are characterized by FTIR, PXRD, TGA, ICP-OES, H2-TPR, BET model, and SEM-EDS. The catalytic activity of these materials is studied for dehydrogenation of sodium borohydride in water at various temperatures under basic conditions. Among tested catalysts, the most promising is Co-BDC, which provides hydrogen generation with a good rate of 1886.8 mL min−1 gcat−1 at 319 K and high efficiency (77.7 %) in the presence of a base. The activation energy determined as 25.4 kJ mol−1 is lower than most cobalt-bearing catalysts for NaBH4 hydrolysis described in the literature. The catalyst can be reused at least ten times, keeping a good overall hydrogen generation yield, and thus can be considered a promising candidate for portable hydrogen fuel systems.

  • Measuring the effectiveness of digital communication - social media performance: an example of the role played by AI-assisted tools at a university
    • Edyta Gołąb-Andrzejak
    2023 Pełny tekst

    The aim of the article is to show the role played by AI-powered tools in measuring the effectiveness of digital communication in social media using a university case study. Therefore, a research problem was formulated to identify the metrics (KPIs) used to measure the effectiveness – non-financial outcomes – of digital social media communication at the university using AI tools. The literature review on the role of AI in digital marketing in social media showed that it is used, inter alia, to measure the effectiveness of digital communication – social performance. The importance of KPIs in digital marketing – indicators for measuring non-financial performance – and the presentation of tools used to analyse the effectiveness of social media campaigns were based on a case study of a higher education institution in Poland. With the application of AI tools (such as ContentStudio, HelloWoofy or Sotrender etc.), it is possible to automate analytical processes for KPIs such as reach, engagement, content or customer service, among others, as well as systematic reporting. This, in turn, provides opportunities to systematically monitor and make improvements to the implemented social media marketing communication strategy – to create a kind of Decision Support System (DSS) to support the aforementioned process. The study is introductory and exploratory in nature. It indicates the importance of tools using AI in business practice – using the case study of a university as an example.

  • Mechanical and structural behavior of high-strength low-alloy steel pad welded by underwater wet welding conditions
    • Rassim Younes
    • Jacek Tomków
    • Idir Abdelhak
    • Mohand Amokrane Bradai
    2023 Pełny tekst INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    The aim of the paper was to determine the metallurgical and mechanical behaviors of a high-strength low-alloy (HSLA) steel pad-welded specimen used in the structures of industrial and naval parts. Then to predict the metallurgical consequences (nature of the phases present) and the mechanical properties (hardness and impact strength) of the pad-welded steel obtained by underwater wet welding with different heat input values. The XRD patterns clearly reveal a ferritic alpha steel S460N for both parameters. The ferritic quantification is above 70 wt% for low-alloy steel. The welded specimens are characterized by the presence of different phases. In a specimen performed with higher heat input, the complex oxide Mn2TiO4 was found to be around 7 wt%. Moreover, the solid solution formed with iron and manganese was observed. The hardness results obtained by indentation showed that the higher heat input resulted in higher hardness values (54 HRC) than for specimen performed with lower parameters (45 HRC). The impact test showed that the toughness of both pad-welded layers is greater than the toughness of the base material (40 kV for S2 and 34 kV for S1 about 27 kV for low-alloy steel). Moreover, it was observed that higher heat input results in increasing the impact strength of pad welds.

  • Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
    • Magdalena Jażdżewska
    • Beata Majkowska-Marzec
    • Andrzej Zieliński
    • Roman Ostrowski
    • Aleksandra Frączek
    • Gabriela Karwowska
    • Jean-marc Olive
    2023 Pełny tekst Materials

    Laser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr alloy surface, with the distance between adjacent laser paths ranging between 20 and 50 µm. The obtained periodic structures were tested to examine the effects of the scan distance on the microstructure using SEM, the roughness and chemical and phase composition using EDS and XRD, and the mechanical properties using the nanoindentation technique. After direct laser writing, the thickness of the melted layers was between 547 and 123 µm, and the surface roughness varied between 1.74 and 0.69 µm. An increase in hardness was observed after laser treatment. The highest hardness, 5.44 GPa, was obtained for the sample modified with a laser beam spacing of 50 µm. The value of the distance has been shown to be important for several properties and related to a complex microstructure of the thin surface layer close to and far from the laser path.

  • Mechanical Properties of Twisted Carbon Nanotube Bundles with Carbon Linkers from Molecular Dynamics Simulations
    • Andrea Pedrielli
    • Maurizio Dapor
    • Konstantinos Gkagkas
    • Simone Taioli
    • Nicola Maria Pugno
    2023 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The manufacturing of high-modulus, high-strength fibers is of paramount importance for real-world, high-end applications. In this respect, carbon nanotubes represent the ideal candidates for realizing such fibers. However, their remarkable mechanical performance is difficult to bring up to the macroscale, due to the low load transfer within the fiber. A strategy to increase such load transfer is the introduction of chemical linkers connecting the units, which can be obtained, for example, using carbon ion-beam irradiation. In this work, we investigate, via molecular dynamics simulations, the mechanical properties of twisted nanotube bundles in which the linkers are composed of interstitial single carbon atoms. We find a significant interplay between the twist and the percentage of linkers. Finally, we evaluate the suitability of two different force fields for the description of these systems: the dihedral-angle-corrected registry-dependent potential, which we couple for non-bonded interaction with either the AIREBO potential or the screened potential ReboScr2. We show that both of these potentials show some shortcomings in the investigation of the mechanical properties of bundles with carbon linkers.

  • Mechanika kontaktu w charakteryzowaniu materiałów inżynierskich
    • Alicja Stanisławska
    2023

    W pierwszej części pracy przedstawiono teoretyczne podstawy mechaniki kontaktu. Omówiono model kontaktu Hertza opisujący zależność pomiędzy obciążeniem przyłożonym do kulistego wgłębnika i jego przemieszczeniem. W dalszej części scharakteryzowano modele niehertzowskie, w których pod uwagę bierze się siły adhezji. Przedstawiono dwa modele uwzględniające adhezyjne przyciąganie sferycznego wgłębnika i podłoża, tj. model Johnsona, Kendalla i Robertsa (JKR), wykorzystujący równowagę pomiędzy zmagazynowaną energią sprężystą a utratą energii powierzchniowej pomiędzy kulistym wgłębnikiem i powierzchnią płaską, oraz model sprężystego kontaktu Derjaguina–Mullera–Toporowa (DMT). Model JKR uwzględnia wpływ nacisku kontaktowego i adhezji tylko wewnątrz obszaru kontaktu, natomiast model DMT uwzględnia dodatkowo siły przyciągania występujące pomiędzy ciałami, które oddziałują także poza strefą kontaktu. W dalszej części monografii zaprezentowano modele dla płaskich powierzchni biorące pod uwagę ich chropowatość. Opisano teorię Greenwooda i Williamsona (GW), która zakłada, że wysokości nierówności mają rozkład gaussowski, a odkształcenie nierówności jest opisane modelem Hertza, oraz teorie Greenwooda i Trippa. Następnie przedstawiono matematyczny opis odkształcania materiału przy jego kontakcie z wgłębnikiem w kształcie stożka, zaprezentowany przez Sneddona. W kolejnym rozdziale omówiono różne metody pomiaru twardości materiałów: Brinella, Meyera, Vickersa, Knoopa, Martensa i Rockwella. Następny rozdział opisuje metodę indentacji. Scharakteryzowano w nim naprężenia i odkształcenia w materiale podczas penetracji przez kulisty i ostry wgłębnik, sposoby określania twardości i sztywności materiału, opisano efekt skali występujący dla małych przemieszczeń wgłębnika, a także sposób wyznaczania gęstości dyslokacji występujących w materiale i ich mobilności. Rozdział ten zawiera też omówienie sposobu wyznaczania współczynnika umocnienia odkształceniowego, krytycznego współczynnika intensywności naprężeń oraz naprężeń własnych przy wykorzystaniu testu indentacji. Znajdują się tu również informacje na temat testu zarysowania. Ostatni rozdział przedstawia wyniki prac naukowych, których autorka jest współautorem, i wyniki badań własnych jeszcze nieopublikowanych, które zostały uzyskane za pomocą indentera.

  • Mechanism of antifreeze protein functioning and the “anchored clathrate water” concept
    • Jan Zielkiewicz
    2023 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    In liquid water, there is a natural tendency to form aggregates that consist of water molecules linked by hydrogen bonds. Such spontaneously formed aggregates are surrounded by a "sea" of disordered water molecules, with both forms remaining in equilibrium. The process of creating water aggregates also takes place in the solvation water of proteins, but in this case the interactions of water molecules with the protein surface shift the equilibrium of the process. In this paper, we analyze the structural properties of the solvation water in antifreeze proteins (AFPs). The results of molecular dynamics analysis with the use of various parameters related to the structure of solvation water on the protein surface are presented. We found that in the vicinity of the active region responsible for the binding of AFPs to ice, the equilibrium is clearly shifted towards the formation of "ice-like aggregates", and the solvation water has a more ordered ice-like structure. We have demonstrated that a reduction in the tendency to create "ice-like aggregates" results in a significant reduction in the antifreeze activity of the protein. We conclude that shifting the equilibrium in favor of the formation of "ice-like aggregates" in the solvation water in the active region is a prerequisite for the biological functionality of AFPs, at least for AFPs having a well-defined ice binding area. Also, our results fully confirm the validity of the "anchored clathrate water" concept, formulated by Garnham et al. (PNAS, (2011), 108, 7363).

  • Mechanochemically synthesized Mn3O4@β-cyclodextrin mediates efficient electron transfer process for peroxymonosulfate activation
    • Huan Liu
    • Xiaohui Dai
    • Lingshuai Kong
    • Meng Xie
    • Chengji Sui
    • Qianyi Zhang
    • Grzegorz Boczkaj
    • Przemysław Kowal
    • Bin Cai
    • Jinhua Zhan
    2023 SEPARATION AND PURIFICATION TECHNOLOGY

    The rational surface engineering of heterogeneous catalysts is of great significance in advanced oxidation processes (AOPs) for eliminating refractory contaminants but remains challenging. In this study, β-cyclodextrin modified Mn3O4 (Mn3O4@β-CD) was prepared through a mechanochemical approach for peroxymonosulfate (PMS) activation, which achieved efficient bisphenol A (BPA) removal via electron transfer process (ETP). The reactive PMS* complex with elevated potential was identified to dominate the ETP by withdrawing electrons from BPA with Mn3O4@β-CD working as electron shuttle, as evidenced by spectroscopy and electrochemical techniques. Experimental results and density functional theory (DFT) calculations showed that the β-CD modification enhanced the interfacial accumulation of pollutants and shortened the migration distance between pollutants (electron donor) and catalysts (electron shuttle) to mediate electron transfer more effectively. Benefitting from the improved ETP, the Mn3O4@β-CD/PMS system showed efficient PMS utilization and practical adaptability in actual waterbodies. This study provides a rational approach for modulating the surface structure of heterogeneous catalysts in PMS-based AOPs for environmental remediation.

  • Membrane distillation assisting food production processes of thermally sensitive food liquid items: a review
    • Emilia Gontarek-Castro
    • Roberto Castro Muñoz
    2023 Pełny tekst CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION

    Physical separation technologies have become important tool for processing in the current food manufacturing industries, especially for the products containing bioactive compounds thanks to their health benefits in costumers. As for the processing of bioactive food ingredients implies the implementation of integrated systems oriented to their separation, fractionation, and recovery. In this field, membrane distillation (MD), which is a thermally driven membrane process, has been proposed as an alternative for the separation and concentration of liquid food items. In principle, MD can separate water and volatile compounds from aqueous feed solutions through a permeate that passes across microporous hydrophobic membranes. The separation via MD is thanks to the vapor pressure difference on both membrane sides. In this review, we analyzed the ongoing experimental efforts aimed to recover and purify food bioactive compounds from the concentration of fruit juices and extracts using MD. Also, the processing of dairy products, concentration of food by-products, and ethanol production and its removal from beverages using MD have been reviewed. Additionally, a feedback on the distinct membrane module configurations and membrane requirements for successful operation is addressed.

  • Merging Proline:Xylitol Eutectic Solvent in Crosslinked Chitosan Pervaporation Membranes for Enhanced Water Permeation in Dehydrating Ethanol
    • Roberto Castro Munoz
    • Maksymilian Plata-Gryl
    • Grzegorz Boczkaj
    2023 Pełny tekst Membranes

    The scope of this research aims at merging a new deep eutectic mixture (DES) into a biopolymer-based membrane for a pervaporation application in dehydrating ethanol. Herein, an L-proline:xylitol (at 5:1) eutectic mixture was successfully synthesized and blended with chitosan (CS). A complete characterization of the hybrid membranes, in terms of morphology, solvent uptake, and hydrophilicity, has been conducted. As part of their applicability, the blended membranes were assayed for their ability to separate water from ethanolic solutions by means of pervaporation. At the highest temperature (50 °C), a water permeation of ca. 0.46 kg m−2 h−1 was acquired, representing a higher permeation than the pristine CS membranes (ca. 0.37 kg m−2 h−1). Therefore, CS membranes demonstrated an enhanced water permeation thanks to their blending with the hydrophilic L-proline:xylitol agent, making these membranes a good candidate for other separations containing polar solvents.

  • Metaliczne nanostruktury i nanostopy na bazie Au i Ag
    • Robert Kozioł
    2023 Pełny tekst

    W niniejszej rozprawie doktorskiej opisano kontrolowane otrzymywanie metalicznych nanostruktur ze złota i srebra, o pożądanych właściwościach optycznych, w wyniku odwilżania termicznego ultracienkich warstw metalicznych. Pokazano w niej wpływ poszczególnych parametrów wytwarzania na końcowo uzyskiwane właściwości nanostruktur plazmonicznych. Dodatkowo, zaprezentowano skuteczność stosowanej preparatyki w otrzymywaniu jednorodnych nanostruktur stopowych, których właściwości optyczne, w konsekwencji kontroli nad zachodzącymi efektami synergistycznymi, były modulowane w zakresie 100 nm wewnątrz widma światła widzialnego. Co więcej, zaprezentowano również potencjalne zastosowanie otrzymywanych w ten sposób nanostruktur jako czujników w środowiskach ciekłych, demonstrując tym samym ich stabilność. Dodatkowo, zaimplementowano techniki z obszaru technologii informatycznej: symulacje metodą różnic skończonych w dziedzinie czasu do wyznaczenia rozkładu pól elektromagnetycznych w płaszczyźnie wytworzonych nanostruktur; oraz uczenia maszynowego celem predykcji wymaganych parametrów syntezy nanostruktur o żądanych właściwościach optycznych.

  • Metallurgical characterization and high-temperature tensile failure of Inconel 617 alloy welded by GTAW and SMAW—a comparative study
    • Sachin Sirohi
    • Naveen Kumar
    • Amit Kumar
    • Shailesh M. Pandey
    • Balamurugan Adhithan
    • Dariusz Fydrych
    • Chandan Pandey
    2023 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART L-JOURNAL OF MATERIALS-DESIGN AND APPLICATIONS

    Two types of the weld joint of Inconel 617 alloy were produced using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes with ERNiCrCoMo-1 filler metal and ENiCrCoMo-1 electrode, respectively. The weld metal showed the segregation of the principle alloying elements like Mo and Cr along the inter-dendritic spaces, triggering the formation of secondary phases. The microstructure characterization of the interface ensured the high dilution, which could be attributed to the closeness in melting point and chemistry of base and filler metal. Microhardness variation, tensile testing at room and high temperature, and Charpy impact test were conducted to investigate the effect of the Mo segregation in the weld zone and heterogeneity in the microstructure of weldments on the mechanical behavior of both the welded joints. The cross-weld tensile tests were conducted at room temperature and 550°C. The tensile test samples failed from the weld zone for each condition with a tensile strength value close to the base metal, which ensured the applicability of the joint for end service. The tensile strength of GTAW-RT, GTAW-HT, SMAW-RT, and SMAW-HT were measured as 766 ± 22 MPa, 570 ± 5 MPa, 760 ± 7 MPa, and 600 ± 8 MPa, respectively. A non-uniform hardness plot was witnessed with the hardness of the GTAW-weld and SMAW-weld zone of 257 ± 8 HV and 285 ± 5 HV, respectively, in the transverse direction. The impact toughness of the weld zone was 84 ± 2 J and 48 ± 4 J for GTAW and SMAW weld zone. The average impact toughness of the GTAW-weld zone was approximately 42% higher than the value of the SMAW-weld zone. In a nutshell, it can be concluded that the welded joint of Inconel 617 produced using the GTAW process with ERNiCrCoMo-1 filler had the best metallurgical and mechanical properties.

  • Metal-Organic Frameworks in Green Analytical Chemistry
    • Justyna Płotka-Wasylka
    • Małgorzata Rutkowska
    • Natalia Jatkowska
    • Zeraati Malihe
    • Sargaze Ghasem
    • Massoud Kaykhaii
    2023 Pełny tekst

    Taking into consideration the rapid expansion of MOFs applications in the analytical chemistry area, it is important to evaluate the existing and future analytical MOF-based methods according to GAC principles. From this point of view, eco-friendly MOFs-based methods should include features such as: green design and synthesis of MOF, evaluation of toxicity issues of MOFs, and incorporation of MOFs in GAC methods. This Chapter will put particular emphasis on the efforts made on greener synthesis of MOFs and the various routes and methods explored in this regard. In addition, their incorporation into less-harmful analytical chemistry methods is discussed.

  • Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
    • Bashar A. F. Esmail
    • Sławomir Kozieł
    • Dustin Isleifson
    2023 Pełny tekst Electronics

    This paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying lengths and spacing. The di-poles are connected in series on both sides, running in parallel through a microstrip line. Effec-tively combining the resonances of the series-fed dipoles and the SIW results in a broad imped-ance bandwidth, ranging from 26.9 GHz to 34.75 GHz. The design offers a gain extending from 9 to 10.5 dBi within the operating bandwidth. To improve gain performance without a substantial increase in antenna size, 11 × 6 MM unit cells have been positioned in front of the antenna. As a result, the proposed antenna achieves a maximum gain of 14.1 dBi at 30.5 GHz while maintaining an operational bandwidth of 7.85 GHz. Additionally, due to the arrangement of the MM-based two series-fed dipoles, the antenna exhibits symmetrical dual-beam E-plane radiation at ±20° at 28 GHz in the end-fire direction. The developed system was experimentally validated and demon-strated excellent agreement between the simulated and measured data.

  • Method for determining of shallow water depths based on data recorded by UAV/USV vehicles and processed using the SVR algorithm
    • Mariusz Specht
    • Bartosz Szostak
    • Oktawia Lewicka
    • Andrzej Stateczny
    • Cezary Specht
    2023 MEASUREMENT

    Bathymetric measurements in waters shallower than 1 m are necessary to monitor seafloor relief changes in the coastal zone. This is especially important for ensuring the safety of navigation, navigation efficiency, as well as during the design and monitoring of hydrotechnical structures. Therefore, the aim of this article is to present a method for determining of shallow water depths based on data recorded by Unmanned Aerial Vehicle (UAV) and Unmanned Surface Vehicle (USV), as well as processed using the Support Vector Regression (SVR) algorithm. Validation studies of this method was carried out on two selected waterbodies (inland and sea) using the DJI Phantom 4 Real Time Kinematic (RTK) UAV and the AutoDron USV. Then, the geospatial data recorded by a drone was applied to determine depths of shallow waterbodies using the SfM algorithm. Subsequently, the determined depths were compared with the depths measured by a Global Navigation Satellite System (GNSS) RTK receiver or a Single Beam Echo Sounder (SBES), in order to assess the accuracy of the proposed method. The research showed that it is able to determine shallow waterbody depths with the accuracy requirements specified for the International Hydrographic Organization (IHO) S-44 special order (depth error ≤ 0.25 m (p = 0.95)), but only to depths not exceeding 1 m. In the inland waterbody, the depth accuracy was 0.22–0.24 m (p = 0.95), while in the sea waterbody the measurement accuracy was higher, amounting to 0.16 m (p = 0.95). However, for the depth range up to 2 m, the results are radically different, because the vertical position error with a 95% confidence level exceeds the value of 0.3 m in the analysed waterbodies.

  • Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
    • Bartosz Szostak
    • Mariusz Specht
    • Paweł Burdziakowski
    • Andrzej Stateczny
    • Cezary Specht
    • Oktawia Lewicka
    2023 MEASUREMENT

    State-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements of shallow waterbodies with the use of UAV-Structure from Motion (SfM) and Support Vector Regression (SVR) algorithms. Proposed model is explained and verified on the basis of measurement campaign on Raduńskie Górne Lake located in Poland. The campaign included GNSS Real Time Kinematic (RTK) bathymetric measurements for robust training dataset and photogrammetric flight pass for SfM point cloud. The presented methodology will allow to perform bathymetric measurements with the accuracy provided for the International Hydrographic Organization (IHO) Special Order (horizontal position error ≤ 2 m (p=0.95), vertical position error ≤ 0.25 m (p=0.95)).

  • Methodology of experimental research on efficiency of hydro-mechanical automatic gearbox
    • Piotr Patrosz
    • Paweł Załuski
    • Marcin Bąk
    • Paweł Śliwiński
    • Mykola Karpenko
    2023 Pełny tekst

    The article shortly describes the design and principle of operation of the hydromechanical gearbox and presents the methodology and design of test stands used for testing hydromechanical proto-type gearbox developed at Technical University of Gdansk. The article presents an approach according to which, in order to obtain reliable measurement data, it is necessary to separate the tests of the hydraulic and mechanical parts of the gearbox. For this reason, the tests of the pump and the hydraulic motor are also presented. To validate this approach sample test results are in-cluded and discussed.

  • Methods of Cyclist Training in Europe
    • Joanna Wachnicka
    • Alicja Jarczewska
    • Giuseppina Pappalardo
    2023 Pełny tekst Sustainability

    The following study aims to address the issue of cyclist training methodologies. Recent European bicycle accident statistics reveal a troubling upward trend. A potential solution to mitigate such incidents involves providing cyclists with comprehensive training encompassing traffic regulations and interactions with fellow road users. We conducted a comparative analysis of the cycling education approaches and cyclist training systems in several countries, including the Netherlands, Germany, Austria, England, Slovenia, Poland, and Italy. This analysis underscored the importance of standardizing training protocols and criteria across Europe. The training model should draw inspiration from countries with well-established cycling cultures and serve as a foundation for harmonizing training practices.

  • Metoda diagnostyki cieplno-przepływowej turbin parowych wykorzystująca elementy algorytmów genetycznych
    • Marta Drosińska-Komor
    2023 Pełny tekst

    Rozprawa doktorska poświęcona jest opisowi budowania metody diagnostyki cieplno-przepływowej z wykorzystaniem elementów algorytmów genetycznych. Do tworzenia założeń i algorytmów metody posłużono się przykładem funkcjonowania bloku elektrowni kondensacyjnej ze szczególnym uwzględnieniem układu łopatkowego turbiny parowej. Celem pracy jest zbudowanie metody diagnostyki cieplno-przepływowej. Zadaniem metody jest przeprowadzenie procesu diagnozy dla pogorszonych parametrów eksploatacyjnych procesu przemian energetycznych bloku energetycznego (np. sprawności) polegająca na detekcji, lokalizacji i identyfikacji przyczyn degradacji urządzeń składowych bloku energetycznego. Motywacją do podjęcia badań jest coraz ważniejsza rola procedur diagnostycznych w eksploatacji obiektów energetycznych Zbudowana w trakcie pracy kwalifikacyjnej metoda diagnostyczna poszukiwania niesprawności i uszkodzeń jest przewidziana do użycia tylko w procedowaniu off-line. Badania nad zastosowaniem metod algorytmów genetycznych dla celów diagnostyki cieplno-przepływowej pokazały, że nie można użyć klasycznego algorytmu genetycznego do wykrywania degradacji wielokrotnych. Intensywne badania wykorzystujące symulacje degradacji eksploatacyjnej turbin doprowadziły do modyfikacji jednego z elementów algorytmu genetycznego – procesu selekcji. Wyniki badań umożliwiły zbudowanie nowej metody diagnostycznej pozwalającej na przeprowadzenie z dobrą dokładnością procesu lokalizacji i identyfikacji przyczyn degradacji wielokrotnych występujących potencjalnie w turbinach parowych.

  • Metoda obliczania skutków wdrożenia strategii zarządzania popytem na energię elektryczną (DSM/DSR) w systemach elektroenergetycznych
    • Wiktoria Stahl
    2023 Pełny tekst

    W niniejszej rozprawie poruszono zagadnienie strategii zarządzania popytem na energię elektryczną (DSM/DSR) i sposobów obliczania efektów ich wdrożenia. W związku z tym opisano oczekiwane efekty wdrożenia tych rozwiązań oraz ich zalety i wady. Zaprezentowano i przeanalizowano istniejące już metody obliczania skutków wdrożenia DSM/DSR. Zaproponowano nową metodę, która poprzez formę algorytmu uporządkowuje proces obliczania i oceny efektów realizacji tych rozwiązań. W ramach metody zaproponowano także zestaw wskaźników opisujących efekty wdrożenia DSM/DSR. Ponadto, metoda pozwala na symulowanie i prognozowanie spodziewanych rezultatów poprzez wykorzystanie symulacji Monte Carlo i modelów ekonometrycznych. Przy pomocy modeli, przedstawiono także czynniki mogące mieć wpływ na powodzenie realizacji strategii zarządzania popytem. W rozprawie przedstawiono również przykład obliczeniowy z wykorzystaniem zaproponowanej metody. Przykład oparty jest na zgromadzonych danych dotyczących preferencji odbiorców w sprawie realizacji strategii zarządzania popytem na energię elektryczną. W ramach obliczeń symulacyjnych przedstawiono potencjał realizacji rozwiązań DSM/DSR w Polsce.

  • Metodologia i metodyka odtworzenia stolarki okiennej w zabytkowych obiektach na przykładzie Muzeum Bursztynu w Wielkim Młynie w Gdańsku
    • Ksenia Piątkowska
    • Elżbieta Ratajczyk-Piątkowska
    • Katarzyna Darecka
    2023 Pełny tekst Wiadomości Konserwatorskie

    W artykule przedstawiono metodologię i metodykę odtworzenia stolarki okiennej w obiekcie zabytkowym, o zachowanej średniowiecznej formie, przy realizacji Muzeum Bursztynu w Wielkim Młynie w Gdańsku. Omówiono wyniki wykonanych badań w tym zakresie i decyzje projektowe odtworzenia okien. Opisano wpływ współczesnych wymagań dotyczących stolarki w obiektach muzealnych na jej kształt i formę. Wykonane dla Muzeum Bursztynu okna są autorską syntezą historii Wielkiego Młyna przedstawiającą współcześnie elewacje ze stolarką okienną w konfiguracji, w której prawdopodobnie nigdy nie istniała, ale która w pełni ilustruje jego przeszłość zgodnie z obecnym stanem wiedzy na temat faz rozwoju obiektu oraz obowiązujących wymagań techniczno-użytkowych.

  • Metody generowania energii
    • Ewa Klugmann-Radziemska
    • Katarzyna Januszewicz
    2023

    Generowanie energii stanowi podstawę funkcjonowania społeczeństw i rozwoju gospodarki światowej. W różnych krajach kluczowe technologie, na których opiera się energetyka, są inne, co zależy zarówno od historycznych podstaw rozwoju tego sektora, postępu technicznego, jak i uwarunkowań politycznych, a co za tym idzie – legislacyjnych. W krajach Unii Europejskiej od wielu lat dominuje trend rozwoju energetyki opartej na źródłach odnawialnych. Jest to często trudne do pogodzenia z istniejącymi rozwiązaniami, gdy – tak jak w naszym kraju – przeważa energetyka oparta na węglu. W krajach wysoko rozwiniętych świadoma polityka państw zaowocowała rozwojem energetyki wiatrowej, słonecznej czy jądrowej. W bilansie niektórych krajów zagospodarowanie energetyczne odpadów stanowi nie tylko uzupełnienie niedoborów paliwowych, lecz także skuteczny sposób pozbycia się tego niewygodnego problemu. Wszystkie omówione w rozdziale technologie pozyskiwania energii elektrycznej i ciepła należy rozważać w ścisłym powiązaniu z polityką zrównoważonego rozwoju i ochroną środowiska, stanowi on więc niejako wprowadzenie do kolejnych rozdziałów.

  • Metody wzmacniania krótkich wsporników słupa w świetle badań eksperymentalnych
    • Krystyna Nagrodzka-Godycka
    2023 Inżynieria i Budownictwo

    W artykule podano metody wzmacniania wsporników słupów, których skuteczność została zweryfikowana badaniami eksperymentalnymi. Niezależnie od zastosowanej metody efektywność wzmocnienia wspornika jest głównie uzależniona od smukłości ścinania wspornika, ilości zbrojenia wewnętrznego i jego wytężenia przed wzmocnieniem.

  • Miasto w działaniu. Nowe pola aktywności społecznej
    • Małgorzata Dymnicka
    • Jarosław Załęcki
    2023

    Miasto od wieków jest areną sporów, przestrzenią konfliktów i miejscem uzgadniania interesów. Już sama relacja mieszkańców z miastem polega na konstytuowaniu przestrzeni, organizacji i reorganizacji współistnienia. Oznacza to, że od socjologicznie rozumianej przestrzeni należy oczekiwać, że uchwyci ona społeczny proces stanowienia. Przestrzeń miasta, w obrębie której żyje dana społeczność, jest jednym z najważniejszych obszarów oddziaływania ze względu na niedostatki, ograniczenia i bariery w dostępie do zasobów. Politycy miast i wielokulturowych metropolii coraz częściej zdają sobie sprawę, że ich zadaniem jest minimalizowanie napięć pomiędzy wyobrażoną wspólnotą podzielanych (lokalnych) tożsamości a konstruującymi ją regułami prawnymi. Można przywołać wiele przykładów, które obrazują skuteczne działania na rzecz zmiany rzeczywistości, jako dowód na aktywność zwyczajnych i niekoniecznie najbardziej zaawansowanych w sztuce życia obywatelskiego i społecznego obywateli, którzy korzystają z prawa i wolności do określonych działań na rzecz szeroko pojętego środowiska zbudowanego.

  • Micro‑ and nano‑ bentonite to improve the strength of clayey sand as a nano soil‑improvement technique
    • Mohadeseh Cheraghalikhani
    • Hamed Niroumand,
    • Lech Bałachowski
    2023 Pełny tekst Scientific Reports

    Nano-additives results in the formation of nano-cementation (NC). This process is recently used to improve the durability of various building materials. NC used to improve the strength of untreated soil materials, also known as nano soil-improvement (NSI). In few years, the role of nano-additives in various types of soils were developed. In this research, the role of micro- and nano- size of bentonite as soil stabilizer was evaluated as first few research to improve geotechnical properties of soils. Nanoadditives prepared by micro- and nano- sizes of bentonite were blend with four formulations. These formulations of micro- and nano- additives at concentrations of 0, 1, 2, and 3%, namely 0% Micro- Bentonite, 1% Micro-Bentonite, 2% Micro-Bentonite, 3% Micro-Bentonite, 0% Nano-Bentonite, 1% Nano-Bentonite, 2% Nano-Bentonite, and 3% Nano-Bentonite, respectively. These formulations of micro- and nano- additives were separately added to soil. Specimens with 3% nano-bentonite showed significant improvement in unconfined compressive strength (UCS) of soil that was more than 2.3-times higher than control specimen in 7-d curing time. Also the performance of micro-bentonite resulted in improvement in UCS of soil that was more than 1.1-times higher than control specimen at 7-d curing time. The secant modulus at 50% of peak stress (E50) of the samples treated with microand nano- additives increased in comparison to untreated specimens. Further, X-ray fluorescence (XRF), scanning electron microscopy, and X-ray diffraction analyses characterized micro- and nanostructures of soil specimens, and showed the performance of nano-additives in improving strength of soils. Results show that nano-bentonite as a type of nano-additives is an effective means of increasing the strength of soils. This research shows the significant of nano-bentonite in soil improvement, as a NSI technique.

  • Microbiota-derived metabolites in colorectal cancer patients in preoperative period
    • Karolina Każmierczak-Siedlecka
    • K. Skonieczna-Żydecka
    • J. Palma
    • Bartosz Kamil Sobocki
    • M. Świerblewski
    • K. Siedlecka-Kroplewska
    • Leszek Kalinowski
    • K. Połom
    2023 Pełny tekst European Review for Medical and Pharmacological Sciences

    Short-chain fat-ty acids (SCFAs) are microbial derived metabo-lites, which have multiple beneficial properties. The amount of SCFAs depends on several fac-tors, such as age, diet (mainly intake of dietary fiber), and overall health condition. The normal proportion between SCFAs is 3:1:1 for acetate, proprionate and butyrate, respectively. In col-orectal cancer (CRC) patients, microbiota alter-ations have been shown. Consequently, metab-olome within the gut might change to a large ex-tent. Therefore, the aim of this study was to anal-yse the content of SCFAs and the proportion be-tween SCFAs in the stool obtained from CRC pa-tients in preoperative period. PATIENTS AND METHODS: This study in-cluded 15 patients with CRC in preoperative pe-riod. The stool samples were taken and stored at -80°C in the Fahrenheit Biobank BBMRI.pl, Med-ical University of Gdansk, Poland. The analysis of SCFAs from stool samples was conducted by means of gas chromatography. RESULTS: This study included mainly males (66.67%, n=10). In all patients, there was abnor-mal proportion between SCFAs. The extreme-ly higher concentration of butyrate was noted in 2 samples (13.33%) compared to the rest of pa-tients. However, based on normal proportion be-tween SCFAs, the results <1 for butyrate were noted in 93.33% of patients. CONCLUSIONS: SCFAs pool is altered in CRC patients, among others characterized by low level of butyrate. It should be considered to administer butyrate supplementation to CRC pa-tients especially prior to surgery to support an appropriate preparation to this treatment.

  • Microcrack monitoring and fracture evolution of polyolefin and steel fibre concrete beams using integrated acoustic emission and digital image correlation techniques
    • Shahzad Ashraf
    • Magdalena Rucka
    2023 Pełny tekst CONSTRUCTION AND BUILDING MATERIALS

    The use of polymer and steel fibres in plain concrete appears to be an excellent solution for limiting crack propagation and improving the post-ductility performance of concrete structures. Based on this premise, this study investigated the fracture evolution of polyolefin fibre-reinforced concrete (PFRC) and steel fibre-reinforced concrete (SFRC) specimens through the integrated application of two diagnostic techniques, acoustic emission (AE) and digital image correlation (DIC), under three-point bending tests. Based on the processing of AE signals, different AE statistical parameters such as the cumulative number of hits, amplitude distribution, and some representative analysis methods including the b-value method, Ib-value method, and AE intensity analysis methods were selected to analyse the early detection of cracking and post-cracking behaviour in PFRC vs SFRC specimens during mechanical degradation. Simultaneously, the DIC technique was used to validate the fracture evolution of the AE results. Furthermore, to verify the reliability of the AE and DIC results, the damage localisation and fracture evolution of the PFRC versus SFRC specimens were confirmed by integrating the AE fracture energies and DIC outcomes. The tests and analysed results showed that the addition of steel fibres to plain concrete significantly improved the ability to restrict crack propagation and provided higher post-cracking resistance compared to PFRC specimens owing to their stronger fibre-matrix bonding, effective fibre bridging, and crack-arresting mechanism. The present study indicates that the combined AE and DIC techniques are highly effective for the early detection of damage and ductility performance in fibre-reinforced concrete structures.

  • Microcracking monitoring and damage detection of graphene nanoplatelets-cement composites based on acoustic emission technology
    • Shahzad Ashraf
    • Suliman Khan
    • Vipin Kumar Oad
    2023 Pełny tekst Case Studies in Construction Materials

    This study aims to identify the micro-cracking pattern and structural applications of cement composites replaced with 0 wt%, 0.04 wt%, and 0.08 wt% contents of graphene nanoplatelets (GNPs) over cement weight through acoustic emission (AE) monitoring under mechanical degradation. The ultraviolet-visible spectroscopy (UV–vis) results showed that at 60 min sonication period, GNP-4 showed maximum absorbance rate of 16.15% compared to the GNP-8. The microstructural characteristics revealed that during hydration of cement there was no apparent cracks appeared in GNPs-cement composites compared to the reference specimen (GNP-0) which was 1.44 mm. The cracking mode and damaged detection of the tested specimens resulted in three distinct stages i.e., (I) pre-peak, (II) peak, and (III) post-peak under mechanical degradation. GNP-4 achieved 780 N flexural capacity which was increased by 30% and 21.87% compared to the GNP-0 and GNP-8. Similarly, a compressive strength of 63.12 MPa, 57.5 MPa, and 56 MPa at 28 days was obtained by GNP-4, GNP-8, and GNP-0, respectively. Based on AE hits and amplitude analysis, the resistance to fracture, damping capacity, and ductility of GNP-4 was improved by 25.30%, 25.1%, and 22.47% respectively, to that of GNP-0. Shear failure (>35 kHz) was observed in GNP-0, while GNPs cement composites recorded tensile failure (<35 kHz) through RA-AF parameters. The cracking pattern through Ib value with a warning sign of 1.5 between micro and macro-cracks and severity of damages through historical index (HI) and severity index (Sr) of GNPs cement composites was determined. Lastly, it was concluded that GNPs contents can significantly improve bending strength and delay the cracks initiation in cement composites.

  • Microemulsion Delivery Systems with Low Surfactant Concentrations: Optimization of Structure and Properties by Glycol Cosurfactants
    • Patrycja Szumała
    • Szymon Mania
    • Balbina Makurat-Kasprolewicz
    • Jolanta Kaplińska
    2023 Pełny tekst MOLECULAR PHARMACEUTICS

    Extensive use of microemulsions as delivery systems raises interest in the safe ingredients that can form such systems. Here, we assessed the use of two glycols, i.e., propylene glycol and pentylene glycol, and their mixtures to manipulate the properties and structure of microemulsions. Obtained systems with glycols were extensively characterized in terms of capacity to incorporate water phase, droplet size, polydispersity, structure type, and rheological and thermal properties. The results of these studies indicate that the composition, structure, and viscosity of the microemulsions can be changed by appropriate quantification of glycols. It has been shown that the type of glycol used and its amount may favor or worsen the formation of microemulsions with the selected oils. In addition, a properly selected composition of oils and glycols resulted in the formation of microemulsions with a reduced content of surfactants and consequently improved the safety of using microemulsions as delivery systems.

  • Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications
    • Nrusingha Pradhan
    • Goutham Reddy
    • Karthikeyan Subramanian
    • Rusan Kumar Barik
    • Sławomir Kozieł
    • Qingsha Cheng
    2023 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    This work introduces a novel frequency tunable self-diplexing antenna (SDA) design based on substrate integrated waveguide (SIW) technology. A modified A-shaped slot is employed on the cavity’s top plane, which is excited by two independent 50 Ω microstrip feed lines to operate at each resonant frequency. The frequency flexibility of the proposed antenna allows for fine-tuning at each resonance frequency. The frequency flexibility has been achieved by employing the substrate’s air- and liquid-filled pockets. The proposed antenna can be configured to operate in the 3.5-3.8 GHz and 5.53-6.2 GHz bands, as demonstrated by the simulation results. With distilled water-filled pockets, the proposed antenna offers peak gains of 5.04 dBi and 5.26 dBi. The proposed SDA exhibits competitive features such as a highly compact size of 0.22λg2 and high isolation (>27dB), which makes it suitable for handheld communication devices. The simulated and measured circuit responses are in good agreement.

  • Microplastics removal from aqueous environment by metal organic frameworks
    • Zhila Honarmandrad
    • Massoud Kaykhaii
    • Jacek Gębicki
    2023 Pełny tekst BMC Chemistry

    This paper provides an overview of recent research performed on the applications of metal–organic frameworks (MOFs) for microplastics (MPs) removal from aqueous environments. MPs pollution has become a major environmental concern due to its negative impacts on aquatic ecosystems and human health. Therefore, developing effective and sustainable methods for removing them from aqueous environments is crucial. In recent years, MOFs have emerged as a promising solution for this purpose due to their unique properties such as high surface area, renewability, chemical stability, and versatility. Moreover, their specific properties such as their pore size and chemical composition can be tailored to enhance their efficiency in removing MPs. It has been shown that MOFs can effectively adsorb MPs from aqueous media in the range of 70–99.9%. Besides some high price concerns, the main drawback of using MOFs is their powder form which can pose challenges due to their instability. This can be addressed by supporting MOFs on other substrates such as aerogels or foams. Meanwhile, there is a need for more research to investigate the long-term stability of MOFs in aqueous environments and developing efficient regeneration methods for their repeated use.

  • Microscopic Imaging to Visualize the Distribution of Dietary Nucleic Acids in Food Products of Various Origins
    • Anna Kościelak
    • Zuzanna Koziara
    • Ana Pons Maria
    • Rafał Płatek
    • Agnieszka Bartoszek-Pączkowska
    2023 Pełny tekst Foods

    Dietary nucleic acids (dietNAs) are being increasingly recognized as important food components with nutritional value. However, the precise dietary recommendations for dietNAs are limited, because established methods for determining the quantity and nutritional role of dietNAs are still lacking. One of the tools to narrow this gap could be microscopic imaging, as a convenient approach to visualize the abundance and distribution of dietNAs in food products. With the aid of appropriate bioinformatic elaboration, such images may in future enable the direct semiquantitative estimation of these macromolecules in food products. In the presented study, two methods of preparing microscopic sections and staining them with DNA-specific fluorochromes were used for microscopic imaging of dietNAs in food products of plant and animal origin. Procedures for preparing formalin-fixed paraffin-embedded sections and cryosections were compared in terms of their usefulness for routine food analysis. Both methods turned out equally suitable for visualizing dietNA distribution in animal and plant products. However, the use of cryosections allowed a significantly shorter analysis time and reduced the consumption of organic solvents. Both of these advantages make the cryosection method preferable while establishing a dedicated methodology for routine assessment of dietNAs in the food industry.

  • Microstructure and Mechanical Properties of Combined GTAW and SMAW Dissimilar Welded Joints between Inconel 718 and 304L Austenitic Stainless Steel
    • Sachin Sirohi
    • Shailesh M. Pandey
    • Aleksandra Świerczyńska
    • Grzegorz Rogalski
    • Naveen Kumar
    • Michał Landowski
    • Dariusz Fydrych
    • Chandan Pandey
    2023 Pełny tekst Metals

    A dissimilar welded joint of Inconel 718 and 304L austenitic stainless steel was prepared using a combined procedure with the gas tungsten arc welding and shielded metal arc welding processes by employing the Ni-based fillers: ERNiCr-3 and ENiCrFe-3. The welded joints were investigated for metallographic testing and mechanical properties, and a relationship was established between the microstructure and the resultant mechanical properties. Microstructural observation revealed the formation of the unmixed zone on the 304L SS side. The weld metal showed that the fully austenitic microstructure consisted of the Nb- and Ti-rich carbide phases along the inter-dendritic spaces. The tensile test results at room temperature showed the failure from the weld metal which might be due to alloying element segregation along the inter-dendritic spaces. However, a tensile test at 600 ◦C showed the failure from the 304L SS base metal with a tensile strength and % elongation value of 377 MPa and 24%, respectively. The hardness plot showed the average hardness value of the weld metal of 236 ± 5 HV, which was higher than the 304L SS BM (204 ± 4 HV) but lower than the IN718 BM (243 ± 5 HV). The impact toughness of the weld metal was 109 J, which was significantly lower than the base metals. The poor impact strength of the weld metal might be due to the evolution of the NbC phase along inter-dendritic spaces

  • Mind the framing: Match purpose and context
    • Monica Fiore, Di
    • Marta Kuc-Czarnecka
    • Samuele Lo Piano
    • Arnald Puy,
    • Andrea Saltelli,
    2023

    In several ways, the following chapters will allude to the concept of frames. The assumptions of a mathematical model tell us what it can explain and what it cannot (see chapter 5). The trade-off between the usefulness of a mathemati- cal model and the scale of complexity it seeks to capture further conditions the narrative, highlighting or downsizing cognitive elements relevant to responsible modelling (see ‘Mathematics and tales’ in chapter 4). Yet, what determines the choice of a model, its assumptions, and its level of complexity? Answering these questions requires a more general perspective that involves frames—that is, the complex of cognitive schemes through which we reason and which we use to make sense of the world. The notion of the frame owes much to the tradition of social studies. Several disciplines have underlined the importance of worldviews and their causal rela- tionships in giving us the coordinates to classify the situations in which we find ourselves. Since public policies are constructs of considerable complexity, policy inquiry has paid great attention to the frames we use to organize information, ideas, and beliefs. For example, Campbell (2002), analysing the effects of ideas, worldviews, and cognitive paradigms on policy-making, defines frames as ‘nor- mative and sometimes cognitive ideas that are located in the foreground of policy debates’.

  • Miniatura, mały format, duże możliwości
    • Joanna Golińska-Pilarek
    • Renata Mazurkiewicz
    • Anna Strzebońska
    • Joanna Wolszczak-Derlacz
    2023 Pełny tekst Forum Akademickie

    MINIATURA to program Narodowego Centrum Nauki przeznaczony do realizacji pojedynczego działania naukowego z zakresu badań podstawowych. Zrównoważona dystrybucja środków w MINIATURZE, zarówno pod względem typów jednostek naukowych, jak i województw, pokazuje, że MINIATURA jest ważną formą wsparcia finansowego w ofercie grantowej NCN, która dobrze odpowiada na zapotrzebowanie mniejszych ośrodków na tzw małe granty

  • Miniaturized Dual-Band SIW-Based Bandpass Filters Using Open-Loop Ring Resonators
    • Nrusingha Pradhan
    • Sławomir Kozieł
    • Rusan Kumar Barik
    • Anna Pietrenko-Dąbrowska
    • Karthikeyan Subramanian
    2023 Pełny tekst Electronics

    This article presents two novel architectures of dual-band substrate integrated waveguide (SIW) bandpass filters (BPFs). Initially, two identical open-loop ring resonators (OLRRs) are coupled face-to-face on the top of the SIW cavity to realize a dual-band single-pole BPF. To obtain two-pole dual-band characteristics, two OLRRs resonant units are assembled horizontally within the top metal layer of the SIW, which is a technique used for the first time in the literature. For demonstration purposes, two types of SIW filters loaded with OLRRs are designed and fabricated. The proposed filters feature an extremely compact size, a low insertion loss, and good selectivity. The single- and two-pole filters have an overall size of 0.012λg2 and 0.041λg2, respectively. The simulated and measured circuit responses are in good agreement.

  • Miniaturized Inline Bandpass Filters Based on Triple-Mode Integrated Coaxial-Waveguide Resonators
    • Muhammad Yameen Sandhu
    • Sharjeel Afridi
    • Adam Lamęcki
    • Roberto Gómez-García
    • Michał Mrozowski
    2023 Pełny tekst IEEE Access

    This work presents a design technique to implement miniaturized cross-coupled bandpass filters in inline physical configurations based on triple-mode resonators. Triple-mode resonances are obtained by using integrated coaxial-waveguide cavity resonators. They consist of two coaxial conducting posts placed in the sidewalls of a rectangular waveguide cavity. In the proposed triplet, a transmission zero (TZ) can be positioned at any of the two sides of the passband by simply locating the coaxial posts either on the same wall or on opposite walls of the rectangular waveguide cavity. Coaxial-to-waveguide mode coupling is implemented by means of coupling screws, which adds flexibility in terms of tuning easiness. Three 9.9-GHz proof-of-concept prototypes corresponding to third- and sixth-order integrated coaxial-waveguide bandpass filters are designed at the electromagnetic-simulation level. Furthermore, the triplet with a TZ below the passband is manufactured and characterized to experimentally validate the engineered 3-D RF filter principle and its underlying design theory.

  • Miniaturized Solid Phase Extraction techniques for different kind of pollutants analysis: State of the art and future perspectives – PART 1
    • Justyna Płotka-Wasylka
    • Natalia Jatkowska
    • Monika Paszkiewicz
    • Magda Caban
    • Michel Y. Fares
    • Aysegul Dogan
    • Salvador Garrigues
    • Natalia Manousi
    • Natasa Kalogiouri
    • Paweł Mateusz Nowak
    • Victoria F. Samanidou
    • Miguel de la Guardia
    2023 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Solid Phase Extraction (SPE) has been practiced in a modern form for more than half a century. It was constantly developing, driven by the analysts needs. These needs are coming from the importance to select an appropriate analytical method, which should have satisfactory accuracy, precision and sensitivity. In the case of sorbent-based microextraction techniques, the choice of miniaturized variants that meet these requirements as well as the requirements of GAC is extremely wide. The increasing popularity of the technique has spurred the influx of many manufacturers into the commercial side of the technology, and many columns, cartridges and discs are comercially available. SPE-type techniques which can be connected with quantification techniques, are perfect to be applied for pollution analysis. The purpose of this article is to provide the reader with an updated, comprehensive overview of modern SPE techniques for different kind of pollutants analysis.

  • Miniaturized solid phase extraction techniques for different kind of pollutants analysis: State of the art and future perspectives – PART 2
    • Justyna Płotka-Wasylka
    • Natalia Jatkowska
    • Monika Paszkiewicz
    • Magda Caban
    • Michel Y. Fares
    • Aysegul Dogan
    • Salvador Garrigues
    • Natalia Manousi
    • Natasa Kalogiouri
    • Paweł Mateusz Nowak
    • Victoria F. Samanidou
    • Miguel De la Guardia
    2023 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Determination of pollutants present in environmental samples at a low concentration level very often requires the analytical protocol that includes analytes isolation and/or enrichment prior to the final quantification. Miniaturized SPE offers an interesting alternative to LLE. Nowadays, many types of sorbents are available and can be used as selective materials for extraction of varied analytes in different kinds of samples. The characteristic of sorbent plays a crucial role because determines the resulting extraction mechanism of particular technique. SPE techniques have numerous positive features. This review provides an updated, comprehensive overview of new types of sorbents used in SPE-based techniques. In addition, miniaturized SPE techniques applied to environmental problems are described, based on the most recent, relevant, and representative examples of successful application. The perspective of the most promising directions for the development of the SPE technology in the near future, and the greatest challenges that will have to be faced, are also outlined.

  • Mitigating metal-organic framework (MOF) toxicity for biomedical applications
    • Paulina Wiśniewska
    • Józef Haponiuk
    • Mohammad Saeb
    • Navid Rabiee
    • Sidi A. Bencherif
    2023 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Metal-organic frameworks (MOFs) are a novel class of crystalline porous materials, consisting of metal ions and organic linkers. These hybrid materials are highly porous and have a large specific surface area, making them of great interest for applications in gas separation, energy storage, biomedical imaging, and drug delivery. As MOFs are being explored for biomedical applications, it is essential to comprehensively assess their toxicity. Although nearly ninety thousand MOFs have been investigated, evaluating and optimizing their physico-chemical properties in relevant biological systems remain critical for their clinical translation. In this review article, we first provide a brief classification of MOFs based on their chemical structures. We then conduct a comprehensive evaluation of in vitro and in vivo studies that assess the biocompatibility of MOFs. Additionally, we discuss various approaches to mitigate the critical factors associated with MOF toxicity. To this end, the effects of chemistry, particle size, morphology, and particle aggregation are examined. To better understand MOFs' potential toxicity to living organisms, we also delve into the toxicity mechanisms of nanoparticles (NPs). Furthermore, we introduce and evaluate strategies such as surface modification to reduce the inherent toxicity of MOFs. Finally, we discuss current challenges, the path to clinical trials, and new research directions.

  • Mobile Networks' Analysis in Terms of QoS Performance Assessment
    • Dariusz Zmysłowski
    • Jan M. Kelner
    • Przemysław Falkowski-Gilski
    2023

    Quality of service (QoS) assessment is one of the basic processes carried out by mobile network operators (MNOs) and regulators of the telecommunications market. Usually, professional companies carry out measurements for various country areas and use cases (scenarios). In this paper, we show exemplary measurement results carried out in drive tests in the vicinity of the Polish capital by a professional company. The measurement campaign included two MNOs and three use cases, i.e., voice calls, video live streaming from YouTube, and web browsing. Various parameters of the received signals and QoS metrics were recorded during the measurements, e.g., reference signal received power, signal-to-interference-plus-noise ratio, mean opinion score (MOS), video MOS, and throughput. One of the MNOs provides services using Universal Mobile Telecommunications Service (UMTS) and Long-Term Evolution (LTE) technologies, while another is based only on LTE technology. The presented results show that higher QoS metrics were obtained for the LTE network than one using UMTS/LTE technologies.

  • Modal Adjustment of Rayleigh Based Structural Damping and Coordinate-Partitioning Algorithm Dedicated to Frictionless Contact Constraints between Multibody System and Structure Modelled with Finite Elements
    • Krzysztof Lipiński
    2023 SSRN Electronic Journal

    The paper presents a dedicated numerical algorithm. The algorithm is advantageous during investigations of the dynamics of a hybrid multibody / finite-elements system. We focus our attention on interactions resulting from mechanical contact. Pointwise contact connects a vertex of the multibody structure and a surface of the elastic reference body. Instead of a positive value of the relative penetration factor, constraint equations model the contact, and Lagrange multipliers model the constraint-associated reactions used in the dynamics equations. In the subsequent steps, the investigated procedure recalls a case-dedicated version of the classic coordinate-portioning algorithm. The dedicated numerical algorithm evaluates the algebraic unknown of the system, i.e., for each set of investigated accelerations, it calculates values of the Lagrange multipliers and values of the selected dependent accelerations resulting from the consistency of the constraint equations. When calculated, the algorithm eliminates them from the remaining equations. Consistently with purely numerical reasons, obtained differential equations are challenging for numerical integration. The paper presents one of the reasons. To solve the misadventure, it proposes an alternative numerically-rational model of the disturbing phenomena. The proposed solution recalls modal adjustment of the damping properties of the elastic subcomponent. We test the efficiency of the paper-proposed methodology with the use of a numerical example. We limit the tests to an example of a purely academic planar structure. Also, we restrict the tested elastic subcomponent to a case of a planar deformable beam. We model it with the use of two-node beam elements. Pin contacts, as well as frictionless pointwise slider-pin contacts, connect the elastic beam and the multibody. The paper presents the case-dedicated constraint equations and their associated Lagrange multipliers. Our initial tests investigate the main consequences of the presence of the uniform Rayleigh model of structural damping. In the subsequent numerical tests, we modify the main parameters of the structural damping. Indicated modification recalls the paper-proposed principles of the abovementioned modal adjustment. Paper-presented figures compare the obtained behaviours with those calculated previously for the Rayleigh model. Even if verified with a purely academic numerical model, the paper-proposed methodology is general.

  • Model studies to identify input parameters of an algorithm controlling electric supply/consumption process by underground iron ore enterprises
    • Oleh Sinchuk
    • Ryszard Strzelecki
    • Tetiana Beridze
    • Ihor Peresunko
    • Vladyslav Baranovskyi
    • Danyil Kobeliatskyi
    • Volodymyr Zapalskyi
    2023 Pełny tekst Mining of Mineral Deposits

    Purpose is the development of the research format of a mathematical model to select and assess input parameters of an algorithm controlling distribution of electric energy flows in the monitoring structure of electricity supply/ consumption by using equipment of mining enterprises engaged in underground iron ore raw materials extraction. Methods. The analytical research involved a theory of random processes adapted to the real conditions. For the purpose, results of experimental measurements have been applied obtained under the conditions of active iron ore enterprises using underground procedures of the raw materials mining. Methods of random functions (i.e. elements of correlation theory) have helped identify the basic input and output parameters characterizing rather completely electric supply consumption as a stochastic process to develop a control algorithm for the process. Originality. The procedure of electric supply/consumption by underground iron ore enterprises has been analyzed in the format of process of a stochastic process of their operation. For the first time, the synthesized mathematical model has been built; both average and disperse stochastic characteristics of electric consumption capacity have been identified; average period of electric energy consumption as a stationary random function during the specified time has been determined; and average number of electric consumption peaks for the interval has been defined as well as average duration of their surges. Analysis of the electric supply/consumption process as a stochastic process has helped solve a problem of the peak influence on the modes of electric energy consumption by receivers of the enterprises. Practical implications. According to the available computing formats, a calculation procedure of the operation parameters of electric supply/consumption is of insufficient accuracy since average values are applied and stochastic nature of the process is ignored, which is typical for the analyzed mining enterprises. The abovementioned restricts the possibility to develop adequate system to control the electric power process in terms of the types of mining enterprises and specificity of their operational technology. The developed methods of electric supply/consumption functioning dynamics as a stochastic process help expand its use while forming and making efficient managerial decisions in the context of the analyzed process.

  • Model zarządzania projektami informatycznymi w jednostkach sądownictwa powszechnego w Polsce
    • Monika Kuźmicz
    2023 Pełny tekst

    Projekty mają istotny wpływ na funkcjonowanie sądów powszechnych. Przyjrzenie się projektom informatycznym realizowanym w sądach wraz z raportem Najwyższej Izby Kontroli dot. sprawności realizowanych projektów informatycznych wymiaru sprawiedliwości doprowadziło do zidentyfikowania głównych problemów podczas realizacji inicjatyw informatycznych. Ponadto przegląd literatury dotyczący zarządzania projektami dla wymiaru sprawiedliwości doprowadził do wskazania luki w tym obszarze. Złożoność i specyfika organizacji publicznych, w szczególności sądów jako ich podzbioru, utrudnia możliwość wykorzystania dostępnych metodyk czy narzędzi wspierających zarządzanie projektami. To doprowadziło do sformułowania procesu badawczego rozprawy, w tym m.in. głównego celu pracy, tj. dostarczenia modelu zarządzania projektami informatycznymi w sądownictwie powszechnym obejmującego przypadki i dobre praktyki, uwzględniającego specyfikę sądów, który w konsekwencji pozwoli na usprawnienie realizacji projektów informatycznych w sądownictwie powszechnym. Do budowy tego modelu wybraną metodę wnioskowania w oparciu o przypadku CBR (ang. Case-Based Reasoning), która zakłada wykorzystywanie doświadczeń dla nowych problemów. W odniesieniu do modelu, CBR pozwala na wykorzystanie dobrych praktyk i przypadków obejmujących procesy, role i artefakty dla nowych projektów. Co więcej metoda ta pozwala na uczenie się i ciągłą rozbudowę modelu, co w przypadku organizacji wrażliwych na ciągłe zmiany otoczenia (np. regulacji prawnych) jakim są sądy jest szczególnie istotne.

  • Modele i algorytmy dla grafowych struktur defensywnych
    • Robert Lewoń
    2023 Pełny tekst

    W niniejszej pracy przeprowadzono analizę złożoności istnienia struktur defensywnych oraz równowag strategicznych w grafach. W przypadku struktur defensywnych badano modele koalicji defensywnych, zbiorów defensywnych i koalicji krawędziowych – każdy z nich w wersji globalnej, tj. z wymogiem dominacji całego grafu. W przypadku modeli równowagi strategicznej badano równowagę strategiczną koalicji defensywnych, równowagę strategiczną zbiorów defensywnych i równowagę strategiczną koalicji krawędziowych. Przedstawiono wielomianowe algorytmy konstruujące najmniejsze struktury defensywne oraz weryfikujące ich istnienie i konstruujące równowagi strategiczne w przypadku drzew. Dodatkowo zweryfikowano trudność obliczeniową badanych problemów poprzez wykazanie ich NP–zupełności dla możliwie wąskich klas grafów. W ten sposób określono zakres stosowalności modeli w przypadku dużych grafów, a dalsze badania skierowano w kierunku podejść aproksymacyjnych, które poszerzą zakres zastosowań dyskutowanych modeli w praktyce. Przebadano również własności teoretyczne modeli, takie jak oszacowania rozmiaru badanych struktur i związki między nimi. Zaproponowano także ogólną koncepcję stanowiącą wspólny trzon dla dyskutowanych modeli, otwierając tym samym kierunki badań w obrębie tego zagadnienia.

  • Modeling and optimization of chemical-treated torrefaction of wheat straw to improve energy density by response surface methodology
    • Samuel Latebo Majamo
    • Temesgen Amibo
    2023 Pełny tekst Biomass Conversion and Biorefinery

    Today, torrefaction is important technique for extending the potential of biomass for improvement of energy density. The independent variables investigated for torrefaction study were temperature, retention time, acid concentration, and particle size. The experiment was designed by central composite design (CCD) method using design expert (version 11). The three dependent variables were higher heating value (HHV), energy enhancement factor (EEF), and mass yield (MY) were carried out. Numerical optimization using response surface method (RSM) to maximize the HHV and EEF with lowest MY was carried out. The maximum HHV of 25.05MJ/kg, lowest MY of 60.15%wt and highest EEF of 1.593 were obtained at 299.99°C, 31.89min of retention time, 0.75g/l of acid concentration and 0.20mm of particle size. Proximate analysis, bulk density, hydrophobicity, energy density, and ultimate analysis of raw and torrefed biomass were determined to analyze the physiochemical properties of the fuel. In addition, thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray difractometer (XRD) were done to distinguish the behavior of raw and torrefed wheat straw. The results implied that energy density of torrefed biomass was well improved when compared with raw biomass. All in all, energy density of torrefed biomass was improved, which can be used as an alternative energy.

  • Modeling and simulation of blood flow under the influence of radioactive materials having slip with MHD and nonlinear mixed convection
    • Sidra Afzal
    • Mubashir Qayyum
    • Muhammad Riaz
    • Adam Wojciechowski
    2023 Pełny tekst Alexandria Engineering Journal

    Radioactive materials are widely in industry, nuclear plants and medical treatments. Scientists and workers in these fields are mostly exposed to such materials, and adverse effects on blood and temperature profiles are observed. In this regard, objective of the current study is to model and simulate blood based nanofluid with three very important radioactive materials, named as Uranium dioxide (UO2), Thorium dioxide (ThO2) and Radium (Rd). In this modeling blood based nanofluid is considered under the influence of magneto hydrodynamic effect, non-linear mixed convection and thermal radiation, Joule heating, along with velocity and temperature slip. A three-dimensional fluid model is considered in bounded domain to justify flow geometry in arteries. System of partial differential equations are converted to highly nonlinear coupled ordinary differential equations by using suitable transformations. The obtained system is solved numerically using Fehlberg Runge–Kutta algorithm. Validity and convergence of the obtained solutions are confirmed through residual errors, numerical uncertainties and comparison with experimental data. Moreover, effect of pertinent fluid parameters on the velocity (radial, axial, tangential) and temperature profiles of blood flow are analyzed graphically. Furthermore, Skin friction and Nusselt number are also analyzed graphically against volume fraction of involved radioactive materials for the case of UO2;ThO2 and Rd comparatively. Analysis reveals that increase in volume fraction of radioactive elements results in increased blood flow through walls in both radial and tangential directions. In case of slip at fluid solid-interface, the highest skin fraction is observed in case of Radium nanoparticles.

  • Modeling of entrained flow steam gasification of sewage sludge
    • Jakub Mularski
    • Kamil Stasiak
    • Michał Ostrycharczyk
    • Michał Czerep
    • Mateusz Wnukowski
    • Krystian Krochmalny
    • Marcin Baranowski
    • Paweł Ziółkowski
    • Mateusz Kowal
    • Łukasz Niedźwiecki
    • Halina Pawlak-kruczek
    • Dariusz Mikielewicz
    2023

    Proper management of sewage sludge becomes increasingly problematic due to legal requirements aiming at diminishing environmental impact, as well as rationalizing the utilization from the point of view of logistics. Steam gasification of sewage sludge can result in very good quality of the producer gas. So far, the works have been focused on the gasification in fixed bed gasifiers. However, this does not allow to take full advantage of the effect of scale, as the scalability of fixed ed gasifiers is limited. Entrained flow gasifiers are scalable up to the order of magnitude of hundreds of megawatts, which was proven for the gasification of coal. Therefore, it seems plausible to suspect that such scalability would allow building gasifiers big enough, to work as a part of bioenergy with carbon capture and storage plants, operating in an economically feasible manner, fully utilizing the effect of scale. However, the optimized design of such units would require robust modeling. This work focuses on different models for sewage sludge steam gasification, allowing accurate predictions of the producer’s gas quality. The core part of this work is a comparison between the results obtained using advanced CFD models in Fluent, as well as two different equilibrium models. Results from all the models are experimentally validated, by entrained flow steam gasification in a 3 m long reactor, with an addition of CO2.