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  • Paid work activity and entrepreneurial cognitions of students – evidence from European emerging economies
    • Liubov Halkiv
    • Paweł Ziemiański
    2024 Pełny tekst Journal of Entrepreneurship in Emerging Economies

    Purpose – This paper aims to investigate whether paid work activity (PWA) experience of students from five emerging economies is related to academic results and self-assessment of possessed entrepreneurial traits. Additionally, the authors verify the relationship between obtaining work experience and the willingness to start own business among students. Design/methodology/approach – Participants included 3,631 students of the first level of higher education at six universities in five countries (Bulgaria, Latvia, Lithuania, Poland and Ukraine). A survey questionnaire was used which included questions on the previous work experience, paid work during university studies, the assessment of competencies related to entrepreneurship and the assessment of the desirability of entrepreneurship as a career choice. Findings – Findings indicate that students who engaged in PWA before studies are more likely to do it during studies.PWAduring studies is related to perceiving oneself as a worse-performing student, but also to the perception of oneself as an entrepreneurial person. No such relationship was found for the PWA experience before entering the university. Itwas also found that students are likely to start their businesses after obtaining work experience. Practical implications – Practical implications pertain to the role of the contemporary academic institutions that should consider their approach to enabling students’ PWA and teaching them how to engage in it for the benefit of their own and the societies to which they belong. It is argued that it may be particularly essential in emerging economies. Originality/value – The correlates of PWA of students have been underexplored. This paper allows broadening the current understanding of this phenomenon. The authors investigated its relationship with feeling entrepreneurial and academic achievements among young people from five emerging economies, which provides valuable insights for policymakers and educational institutions. It is argued that such insights may be particularly essential in emerging economies. Additionally, the authors contribute to advancing two theories that have not been extensively used in the entrepreneurial context: expectancy theory and social learning theory of career development.

  • Palindromic carbazole derivatives: unveiling their antiproliferative effect via topoisomerase II catalytic inhibition and apoptosis induction
    • Mateusz Olszewski
    • Natalia Maciejewska
    • Anoop Kallingal
    • Agnieszka Chylewska
    • Aleksandra Dąbrowska
    • Małgorzata Biedulska
    • Mariusz Makowski
    • José M. Padrón
    • Maciej Bagiński
    2024 Pełny tekst JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY

    Human DNA topoisomerases are essential for crucial cellular processes, including DNA replication, transcription, chromatin condensation, and maintenance of its structure. One of the significant strategies employed in cancer treatment involves the inhibition of a specific type of topoisomerase, known as topoisomerase II (Topo II). Carbazole derivatives, recognised for their varied biological activities, have recently become a significant focus in oncological research. This study assesses the efficacy of three symmetrically substituted carbazole derivatives: 2,7-Di(2-furyl)-9H-carbazole (27a), 3,6-Di(2-furyl)-9H-carbazole (36a), and 3,6-Di(2-thienyl)-9H-carbazole (36b) – as anticancer agents. Among investigated carbazole derivatives, compound 3,6-di(2-furyl)-9H-carbazole bearing two furan moieties emerged as a novel catalytic inhibitor of Topo II. Notably, 3,6-di(2-furyl)-9H-carbazole effectively selectively inhibited the relaxation and decatenation activities of Topo IIα, with minimal effects on the IIβ isoform. These findings underscore the potential of compound 3,6-Di(2-furyl)-9H-carbazole as a promising lead candidate warranting further investigation in the realm of anticancer drug development.

  • Partially Isolated Multi-Active Bridge DC-DC Converter with Bidirectional EV Charging Ports
    • Mykola Lukianov
    • Enrique Romero Cadaval
    • Gabriele Arena
    • Ryszard Strzelecki
    2024

    There is a growing interest in multiport converters due to their ability to interconnect various energy sources and loads using reduced number of components. Regarding electric vehicle (EV) chargers connection, existing multiport solutions either lack scalability, featuring only one isolated charging port or the operation of ports depend on each other, complicating the converter control algorithm. This article proposes a partially isolated multi-active bridge (MAB) converter capable of connecting battery energy storage (BES) and an arbitrary number of EV chargers to the DC grid, aiming to resolve abovementioned problems. The proposed MAB converter requires 6N switches, whereas the conventional solution with independent 3-phase interleaved buck-boost and N DAB converters needs 8N+6 switches to connect BES and N EVs to the DC grid (N - odd number of EV charging ports). Simulation results have proven the ability of the converter ports to work independently in bidirectional operation modes for different BES and EV power levels.

  • Path integrals formulations leading to propagator evaluation for coupled linear physics in large geometric models
    • L. Penazzi
    • S. Blanco
    • C. Caliot
    • C. Coustet
    • M. El Hafi
    • R. Fournier
    • J. Gautrais
    • Anna Golijanek-Jędrzejczyk
    • M. Sans
    2024 COMPUTER PHYSICS COMMUNICATIONS

    Reformulating linear physics using second kind Fredholm equations is very standard practice. One of the straightforward consequences is that the resulting integrals can be expanded (when the Neumann expansion converges) and probabilized, leading to path statistics and Monte Carlo estimations. An essential feature of these algorithms is that they also allow to estimate propagators for all types of sources, including initial conditions. The resulting practice is a single Monte Carlo run, for one given set of sources, producing propagators that can later be used with any other set of sources for fast simulations, typically as parts of optimization, inversion, sensitivity analysis and command control algorithms. The present paper illustrates how this practice can be extended to problems involving several interacting physics, provided that their coupling is only at the boundary of the system or at interfaces between sub-parts, and may itself be given the form of a second kind Fredholm equation. A full practical implementation is described as part of the Stardis code, with the example of transfering heat via the coupling of radiation, reaction-diusion and convection as typically expected in the multidisciplinary context of urban climate modeling. Besides, we show how recent advances in computer graphics indicate that these algorithms can be made numerically extremely ecient when facing large CAD geometries: computing the propagator becomes strictly independent of the geometry refinement, i.e. is identical whatever the number of triangles and tetraedra used to numerize the surface and volume descriptions. To the best of our knowledge this is the first report of propagator computations that remains practical for coupled physics in large CAD geometries.

  • Pendant Proton-Relays Systematically Tune the Rate and Selectivity of Electrocatalytic Ammonia Generation in a Fe-Porphyrin Based Metal-Organic Framework
    • Arnab Ghatak
    • Shiva Shanker Golla
    • Subrahmanyam Sappati
    • Liberman Itamar
    • Ran Shimoni
    • Idan Hod
    2024 ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

    Electrocatalytic nitrite reduction (eNO2RR) is a promising alternative route to produce ammonia (NH3). Until now, several molecular catalysts have shown capability to homogeneously reduce nitrite to NH3, while taking advantage of added secondary-sphere functionalities to direct catalytic performance. Yet, realizing such control over heterogeneous electrocatalytic surfaces remains a challenge. Herein, we demonstrate that heterogenization of a Fe-porphyrin molecular catalyst within a 2D Metal-Organic Framework (MOF), allows efficient eNO2RR to NH3. On top of that, installation of pendant proton relaying moieties proximal to the catalytic site, resulted in significant improvement in catalytic activity and selectivity. Notably, systematic manipulation of NH3 faradaic efficiency (up to 90%) and partial current (5-fold increase) was achieved by varying the proton relay-to-catalyst molar ratio. Electrochemical and spectroscopic analysis show that the proton relays simultaneously aid in generating and stabilizing of reactive Fe-bound NO intermediate. Thus, this concept offers new molecular tools to tune heterogeneous electrocatalytic systems.

  • Performance and emission characteristics of diesel engines running on gaseous fuels in dual-fuel mode
    • Nhanh Van Nguyen
    • Swarup Kumar Nayak
    • Huu Son Le
    • Jerzy Kowalski
    • Balakrishnan Deepanraj
    • Xuan Quang Duong
    • Thanh Hai Truong
    • Dung Viet Tran
    • Nam Dao Cao
    • Phuoc Quy Phong Nguyen
    2024 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    Conventional fossil fuels are being substituted with alternative green fuels because of their greenhouse gas emissions and pollution problems, which pose a severe threat to the environment. Several studies have reported the usage of biodiesel and gaseous fuels in both single and dual-fuel modes. Gaseous fuels such as producer gas, biogas, syngas, and hydrogen produced from renewable biomass could potentially be used along with biodiesel in dual-fuel engines. Still, these are the least investigated in terms of their use as potential energy carriers. This review article encapsulates the viability as well as the impact of various gaseous fuels, including producer gas, biogas, compressed natural gas, liquefied petroleum gas, syngas, and hydrogen, in dual-fuel mode diesel engines with the aim of evaluating the performance, emission, and combustion behavior at various induction as well as operational parameters. Considering emission behaviors of diesel engines fueled with producer gas, biogas, compressed natural gas, and hydrogen, it is found that hydrocarbon and carbon monoxide emissions increase in the range 17.5e31.4% and 11.73e23.6%, respectively. On the contrary, oxide of nitrogen and smoke opacity tend to reduce from14.3 to 18.2% and 21.4%36.5e63.7%, respectively. Moreover, there is a slight deterioration in performance characteristics for diesel engines fueled with producer gas, biogas, compressed natural gas, and hydrogen in the range of 2.1e8.84% for brake thermal efficiency, and 3.1e7.3% for brake-specific energy consumption. In addition, the combustion characteristics of gaseous fuels is also discussed in detail. Moreover, a SWOT analysis has been carried out with an emphasis on possibilities for usage of gaseous fuels in dual-fuel diesel engines. Finally, the limitations and perspectives of using gaseous fuels are also critically presented.

  • Performance and Energy Aware Training of a Deep Neural Network in a Multi-GPU Environment with Power Capping
    • Grzegorz Koszczał
    • Jan Dobrosolski
    • Mariusz Matuszek
    • Paweł Czarnul
    2024

    In this paper we demonstrate that it is possible to obtain considerable improvement of performance and energy aware metrics for training of deep neural networks using a modern parallel multi-GPU system, by enforcing selected, non-default power caps on the GPUs. We measure the power and energy consumption of the whole node using a professional, certified hardware power meter. For a high performance workstation with 8 GPUs, we were able to find non-default GPU power cap settings within the range of 160–200 W to improve the difference between percentage energy gain and performance loss by over 15.0%, EDP (Abbreviations and terms used are described in main text.) by over 17.3%, EDS with k = 1.5 by over 2.2%, EDS with k = 2.0 by over 7.5% and pure energy by over 25%, compared to the default power cap setting of 260 W per GPU. These findings demonstrate the potential of today’s CPU+GPU systems for configuration improvement in the context of performance-energy consumption metrics.

  • Performance Comparison of Automatically Generated Topologically Agnostic Patch Antennas
    • Adrian Bekasiewicz
    • Khadijeh Askaripour
    2024 Pełny tekst

    Real-world antenna design typically relies on empirical methods, where the development starts with structure synthesis followed by its iterative adjustments to achieve the desired performance. Although the outlined approach proved to be successful, it is also dependent on engineering experience. Alternatively, development can be performed automatically based on the specifications. In this work, an unsupervised design of topologically agnostic patch antennas is considered. The method involves a random generation of feasible topologies, followed by classification of the designs and their cost-efficient numerical optimization. The outlined framework has been used to determine two sets of geometrically distinct radiators dedicated to work for the frequency ranges of 5.3-5.9 GHz and 7-8 GHz, respectively. The generated antennas have been compared in terms of the electrical and radiation performances. The results indicate that the use of free-form topologies has a notable effect on the performance of antennas developed to operate in the given frequency spectrum.

  • Performance of the Direct Sequence Spread Spectrum Underwater Acoustic Communication System with Differential Detection in Strong Multipath Propagation Conditions
    • Jan Schmidt
    • Iwona Kochańska
    • Aleksander Schmidt
    2024 Pełny tekst Archives of Acoustics

    The underwater acoustic communication (UAC) operating in very shallow-water should ensure reliable transmission in conditions of strong multipath propagation, significantly disturbing the received signal. One of the techniques to achieve this goal is the direct sequence spread spectrum (DSSS) technique, which consists in binary phase shift keying (BPSK) according to a pseudo-random spreading sequence. This paper describes the DSSS data transmission tests in the simulation and experimental environment, using different types of pseudo-noise sequences: m-sequences and Kasami codes of the order 6 and 8. The transmitted signals are of different bandwidth and the detection at the receiver side was performed using two detection methods: non-differential and differential. The performed experiments allowed to draw important conclusions for the designing of a physical layer of the shallow-water UAC system. Both, m-sequences and Kasami codes allow to achieve a similar bit error rate, which at best was less than 10−3. At the same time, the 6th order sequences are not long enough to achieve an acceptable BER under strong multipath conditions. In the case of transmission of wideband signals the differential detection algorithm allows to achieve a significantly better BER (less than 10−2) than nondifferential one (BER not less than 10−1). In the case of narrowband signals the simulation tests have shown that the non-differential algorithm gives a better BER, but experimental tests under conditions of strong multipath propagation did not confirm it. The differential algorithm allowed to achieve a BER less than 10−2 in experimental tests, while the second algorithm allowed to obtain, at best, a BER less than 10−1. In addition, two indicators have been proposed for a rough assessment which of the detection algorithms under current propagation conditions in the channel will allow to obtain a better BER.

  • Periodic Solutions of Generalized Lagrangian Systems with Small Perturbations
    • Joanna Janczewska
    2024 Pełny tekst Qualitative Theory of Dynamical Systems

    In this paper we study the generalized Lagrangian system with a small perturbation. We assume the main term in the system to have a maximum, but do not suppose any condition for perturbation term. Then we prove the existence of a periodic solution via Ekeland’s principle. Moreover, we prove a convergence theorem for periodic solutions of perturbed systems.

  • Pharmaceuticals wastewater treatment via different advanced oxidation processes: Reaction mechanism, operational factors, toxicities, and cost evaluation – A review
    • Jibran Iqbal
    • Noor S. Shah
    • Javed Ali
    • Mu. Naushad
    • Grzegorz Boczkaj
    • Farrukh Jamil
    • Shamshad Khan
    • Long Li
    • Behzad Murtaza
    • Changseok Han
    2024 SEPARATION AND PURIFICATION TECHNOLOGY

    Pharmaceuticals comprises different drugs used for treating different infections in human being and animals. The huge quantities of pharmaceuticals used are found to discharge into different water resources and cause different health and environmental problems. The continuous and large-scale discharge of pharmaceuticals increases their persistency which can consequently make them more toxic. The different advanced oxidation processes (AOPs) were found to effectively treat pharmaceuticals contaminated water. The AOPs showed high efficiency in the treatment of acetaminophen, sulfamethoxazole, metronidazole. ciprofloxacin. sulfadiazine, sulfamethazine, amoxicillin, ibuprofen, carbamazepine, and tetracycline. The pharmaceuticals, amitrole, norfloxacin, atenolol, chloramphenicol, berberine, diclofenac, and sulfadiazine showed persistency to some AOPs. The AOPs yield different reactive radicals with predominantly hydroxyl radical (•OH)- and sulfate radical (SO4•−) which showed fast reactivity with pharmaceuticals. Different mechanistic approaches were systematically reviewed which verify the yield, reactivities, and degradation pathways of •OH and SO4•−. Different factors, such as pH, dose of peroxides and activators, level of pharmaceuticals contamination, and common inorganic anions were found to influence the effectiveness of AOPs. The effectiveness of the AOPs in term of cost and detoxification of target pharmaceuticals suggested to select preferably AOPs which are economical and form non-toxic and/or less toxic products. The different challenges, such as treatment of mixture of pharmaceuticals and treatment in real wastewater which can further increase potential of treatment are discussed.

  • Phospholipid-functionalized gold electrode for cellular membrane interface studies - interactions between DMPC bilayer and human cystatin C
    • Paweł Niedziałkowski
    • Przemysław Jurczak
    • Marta Orlikowska
    • Anna Wcisło
    • Jacek Ryl
    • Tadeusz Ossowski
    • Paulina Czaplewska
    2024 BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

    This work describes the electrochemical studies on the interactions between V57G mutant of human cystatin C (hCC V57G) and membrane bilayer immobilized on the surface of a gold electrode. The electrode was modified with 6-mercaptohexan-1-ol (MCH) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). DMPC was used as a membrane mimetic for monitoring electrochemical changes resulting from the interactions between the functionalized electrode surface and human cystatin C. The interactions between the modified electrode and hCC V57G were investigated by cyclic voltammetry and electrochemical impedance spectroscopy in a phosphate buffered saline (PBS) containing Fe(CN)63−/4- as a redox probe. The electrochemical measurements confirm that fabricated electrode is sensitive to hCC V57G at the concentration of 1 × 10−14 M. The incubation studies carried out at higher concentrations resulted in insignificant changes observed in cyclic voltammetry and electrochemical impedance spectroscopy measurements. The calculated values of surface coverage θR confirm that the electrode is equally covered at higher concentrations of hCC V57G. Measurements of wettability and surface free energy made it possible to determine the influence of individual structural elements of the modified gold electrode on its properties, and thus allowed to understand the nature of the interactions. Contact angle values confirmed the results obtained during electrochemical measurements, indicating the sensitivity of the electrode towards hCC V57G at the concentration of 1 × 10−14 M. In addition, the XPS spectra confirmed the successful anchoring of hCC V57G to the DMPC-functionalized surface.

  • Physicochemical and Volatile Compounds Analysis of Fruit Wines Fermented with Saccharomyces cerevisiae: FTIR and Microscopy Study with Focus on Anti-Inflammatory Potential
    • Paweł Paśko
    • Agnieszka Galanty
    • Tomasz Dymerski
    • Mo Young Kim
    • Yong-Seo Park
    • Patricia Cabrales-Arellano
    • Victor Velazquez Martinez
    • Efren Delgado
    • Mikolaj Gralak
    • Joseph Deutsch
    • Dinorah Barasch
    • Alina Nemirovski
    • Shela Gorinstein
    2024 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The growing trend in fruit wine production reflects consumers’ interest in novel, diverse drinking experiences and the increasing demand for healthier beverage options. Fruit wines made from kiwi, pomegranates, and persimmons fermented using S. bayanus Lalvin strain EC1118 demonstrate the versatility of winemaking techniques. Kiwifruit, persimmon, and pomegranate wines were analyzed using HPLC and GC-TOFMS analyses to determine their concentrations of phenolic acids and volatile compounds. These results were supported by Fourier transform infrared (FTIR) spectroscopy to characterize and compare chemical shifts in the polyphenol regions of these wines. The wines’ characterization included an anti-inflammatory assay based on NO, TNF-alpha, and IL-6 production in the RAW 264.7 macrophage model. FTIR spectroscopy predicted the antioxidant and phenolic contents in the wines. In terms of polyphenols, predominantly represented by chlorogenic, caffeic, and gallic acids, pomegranate and kiwifruit wines showed greater benefits. However, kiwifruit wines exhibited a highly diverse profile of volatile compounds. Further analysis is necessary, particularly regarding the use of other microorganisms in the fermentation process and non-Saccharomyces strains methods. These wines exhibit high biological antioxidant potential and health properties, providing valuable insights for future endeavors focused on designing healthy functional food products.

  • Planetary roller extruders in the sustainable development of polymer blends and composites – Past, present and future
    • Krzysztof Formela
    • Barış Eyigöz
    2024 Express Polymer Letters

    Screw extruders as continuous flow reactors allow the synthesis of new polymers, preparation of polymer blends and composites, and modification or functionalization of commercially available polymers. Literature data shows that the twin screw extrusion is the most popular solution used for this purpose. In contrast, the number of scientific papers on alternative methods, such as multi-screw extruders, is somewhat limited. This paper is the first review of the application of planetary roller extruders in the compounding and reactive processing of polymer blends and composites. To fill current knowledge gaps, we discuss the advantages and disadvantages of planetary roller extruders compared to other screw extruders. Moreover, we summarize recent advances in planetary roller extrusion in producing thermal sensitive and biodegradable polymeric materials, rubber compounds, materials for 3D printing, or plastics and rubber recycling. This work also proposes the possible scenarios for further sustainable development of polymer blends and composites using planetary roller extruders.

  • Plant-based meat substitute analysis using microextraction with deep eutectic solvent followed by LC-MS/MS to determine acrylamide, 5-hydroxymethylfurfural and furaneol
    • Dominika Osiecka
    • Christina Vakh
    • Patrycja Makoś-Chełstowska
    • Paweł Kubica
    2024 Pełny tekst ANALYTICAL AND BIOANALYTICAL CHEMISTRY

    For the analysis of plant-based meat substitutes and the determination of Maillard reaction products such as acrylamide, 5-hydroxymethylfurfural and furaneol, a novel and effective procedure based on hydrophobic natural deep eutectic solvent and liquid chromatography coupled with tandem mass spectrometry was developed for the first time. The 49 compositions of the deep eutectic solvents were designed and screened to select the most suitable option. The terpenoids eugenol and thymol in a molar ratio of 2:1 were selected as precursors for solvent formation, allowing effective extraction of the target analytes. The developed procedure comprised two main steps: extraction — in which the analytes are isolated from the solid sample due to the salting-out effect and pre-concentrated in the deep eutectic solvent, and back-extraction — in which the analytes are re-extracted into the formic acid solution for subsequent mass spectrometric detection. As the density of the aqueous phases changed during the extraction and back-extraction steps, the phenomenon of inversion of the coalesced organic phase was observed, which simplified the withdrawing of the phases. The linear range was 1–50 ng/mL for acrylamide, 10–1000 ng/mL for 5-hydroxymethylfurfural and 200–1000 ng/mL for furaneol with coefficients of determination above 0.9952. The developed method was fully validated and found recoveries were in the range 83–120%, with CVs not exceeding 4.9%. The method was applied to real sample analysis of pea-based meat substitutes.

  • Plastic Debris in the Stomach of the Invasive Signal Crayfish Pacifastacus leniusculus from a Baltic Coastal River
    • A. Dobrzycka‐Krahel
    • Michał Skóra
    • Agnieszka Pladzyk
    2024 Pełny tekst Water

    Pollution by plastic debris, widely recognized as a growing global problem [1-3] is caused by the production of synthetic polymers. Over recent years, the production of plastics has increased, while in Europe, fossil-based plastics production has decreased, and recycled plastics production has increased [4]. There are different types of plastics. Some types of plastic ingredients, applied in a wide variety of cosmetics and personal care products (PCCP), occur as particulate microplastics < 5 mm [5]. Larger plastics, under environmental conditions, may fragment to microplastics [6]. Plastics are widely used by humans, and, as waste, they become a pollutant in the environment. Plastics may pose risks for aquatic ecosystems [7]. Plastics are water-insoluble, have low degradation rates [8], may be ingested by various organisms ranging from zooplankton to fish and mammals, and accumulate in the intestines through the aquatic food web [9]. Moreover, plastic can adsorb organic contaminants from the surrounding media, which can be transferred to organisms upon ingestion [10]. Most studies on plastic debris are limited to the marine environment [7,10,11]. However, rivers are significant sources of plastic pollution for coastal and offshore areas [12,13]. The bioaccumulation of plastics was previously confirmed in many aquatic species, e.g., Gammarus setosus [14], Carcinus maenas [15], Palaemonetes pugio [16], Amphibalanus amphitrite [17], and Mytilus edulis Linnaeus, 1758 [18]. However, to our knowledge, their presence in the signal crayfish Pacifastacus leniusculus (Dana, 1852) has not been confirmed. The signal crayfish is one of the most widespread non-indigenous crayfish in Europe [19]. They are large, euryhaline, attractive for consumption and for this reason were introduced for aquaculture into many countries [20,21]. In the 1990s, this species was introduced into the Wieprza River drainage area [22,23]. Once they escaped into the wild, they became exploited by local inhabitants. The aim of this study was to determine the level of contamination by plastics in the invasive signal crayfish from the Baltic coastal tributary that is considered as a potential local food source. The specific objectives were: determination of plastic contamination in different river sections, assess microplastic amount and type, verification if there are any differences between sexes, sizes and condition of organisms resulting from distinct traits of individuals.

  • PLC-based Implementation of Stochastic Optimization Method in the Form of Evolutionary Strategies for PID, LQR, and MPC Control
    • Kajetan Zielonacki
    • Jarosław Tarnawski
    2024 INTERNATIONAL JOURNAL OF CONTROL AUTOMATION AND SYSTEMS

    Programmable logic controllers (PLCs) are usually equipped with only basic direct control algorithms like proportional-integral-derivative (PID). Modules included in engineering software running on a personal computer (PC) are usually used to tune controllers. In this article, an alternative approach is considered, i.e. the development of a stochastic optimizer based on the (μ,λ) evolution strategy (ES) in a PLC. For this purpose, a pseudorandom number generator (pRNG) was implemented, which is not normally available in most PLCs. The properties of popular random number generation methods were analyzed in terms of distribution uniformity and possibility of implementation in a PLC. The Wichmann-Hill (WH) algorithm was chosen for implementation. The developed generator with a uniform distribution was the basis for the implementation of a generator with a normal distribution. Both generators are the engines of the stochastic optimization algorithm in the form of the (μ, λ) strategy. For verification purposes, a modular servomechanism laboratory set was used as a test object for PID and linear-quadratic regulator (LQR) control. Moreover, the possibility of using the developed optimizer was shown in an application of model predictive control (MPC). Comprehensive tests confirmed the correctness of the implementation and high functionality of the developed software. Calculation time issues are also investigated.

  • Politechnika Gdańska z prywatną siecią 5G i zespołem specjalizowanych laboratoriów badawczych
    • Józef Woźniak
    • Krzysztof Gierłowski
    • Michał Hoeft
    • Wojciech Gumiński
    • Krzysztof Nowicki
    • Jacek Rak
    • Jarosław Sadowski
    • Piotr Rajchowski
    • Sławomir Gajewski
    2024 Pełny tekst Pismo PG

    W artykule przedstawiono pierwszą część opisu laboratorium (a właściwie zespołu laboratoriów) sieci 5G, otwartego w ostatnim okresie na Wydziale ETI Politechniki Gdańskiej. W części tej zawarto wybrane cechy technologii 5G, a także podstawowe założenia i możliwości oferowane przez nowoutworzone laboratorium. Laboratorium jest efektem kilkuletnich prac związanych z realizacją projektu PL-5G: „Krajowe laboratorium sieci i usług 5G wraz z otoczeniem”. Intensywne prace projektowe oraz wdrożeniowe realizowane były przez konsorcjum 6. jednostek naukowo-badawczych, w skład którego wchodziły, poza Politechniką Gdańską, Politechnika Warszawska (lider projektu), Akademia Górnicza-Hutnicza w Krakowie, Politechnika Wrocławska, Instytut Łączności – Państwowy Instytut Badawczy oraz Instytut Chemii Bioorganicznej PAN – Poznańskie Centrum Superkomputerowo-Sieciowe (PCSS). Na początku 2020 roku projekt PL-5G został oficjalnie wpisany na tzw. Polską Mapę Infrastruktury Badawczej. Unikatowość naszego przedsięwzięcia, bez wątpienia nawet w skali światowej, związana jest zarówno ze stworzeniem sieci międzyregionalnej na rzadko spotykaną skalę (sieć łączy główne ośrodki akademickie w Polsce), jak też ogromną różnorodnością specjalizowanych instalacji lokalnych, z wręcz tysiącami urządzeń do badań nad sieciami i usługami związanymi zarówno z technologią 5G, jak i kolejną generacją 6G. Połączenie wspomnianych ośrodków superszybką siecią operacyjną, ze światłowodami, udostępnianymi przez PCSS i sieć akademicką PIONIER oraz wspieraną przez Centra Danych w każdej lokalizacji zapewni bez mała pełny dostęp do praktycznie wszystkich zasobów, także tych lokalnych, u poszczególnych konsorcjantów. Dodajmy też, że w naszej, gdańskiej lokalizacji.. Po stronie Politechniki Gdańskiej w realizację projektu zaangażowane były zespoły z dwóch katedr Wydziału ETI PG – Katedry Teleinformatyki oraz Katedry Systemów i Sieci Radiokomunikacyjnych. Dokładniejszy opis wyposażenia oraz oferty badawczej laboratorium zostanie zaprezentowany w części drugiej artykułu.

  • Polskie górnictwo i hutnictwo miedzi w sztuce medalierskiej
    • Dariusz Świsulski
    2024 Pełny tekst Hutnik - Wiadomości Hutnicze

    Polska jest jednym z największych producentów miedzi na świecie. W artykule przypomniano historię górnictwa miedzi od najdawniejszych lat przez odkrycie złóż miedzi przez Jana Wyżykowskiego do czasów współczesnych. Obecnie górnictwem i hutnictwem miedzi zajmuje się wiele przedsiębiorstw w ramach KGHM Polska Miedź. Ich opis zilustrowano zdjęciami: medali, plakiet i statuetek, które znajdują się w zbiorach autora.

  • Polskie szkolnictwo wyższe w drobnej sztuce użytkowej: monety, medale, znaczki
    • Dariusz Świsulski
    2024

    W książce przedstawiono pamiątki związane z 76 uczelniami. Większość z nich znajduje się w wykazie Ministerstwa Nauki i Szkolnictwa Wyższego. Uczelnie te wielokrotnie podlegały reorganizacji, zmieniały nazwy i struktury, podlegały łączeniu. Są wśród nich również takie, które z różnych przyczyn zlikwidowano lub które po 945 roku znalazły się poza granicami Polski i zostały przekształcone w uczelnie radzieckie, a później ukraińskie lub litewskie.