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Multi-channel radio-over-fiber communication systems through modulation instability phenomenon
- Rasul Azizpour
- Hassan Zakeri
- Gholamreza Moradi
- Mohammad Alibakhshikenari
- Francisco Falcone
- Bo Liu
- Tayeb Dendini
- Imko Park
- Sławomir Kozieł
- Ernesto Limiti
2024 Pełny tekst IEEE Photonics Journal
Recent advancements in Radio-over-Fiber (RoF) technology have positioned it as a promising solution for highcapacity wireless communications. This paper explores novel applications of RoF systems in enhancing phased array antenna (PAA) performance for multi-channel wireless communication applications through the modulation instability (MI) phenomenon. Utilizing fibers experiencing MI with varying group velocity dispersions (β2) of -20, -11.3, -3.2, and -2 ps2/km, the RoF system achieves operational flexibility across distinct central frequencies of 12, 16, 30, and 38 GHz, respectively. This approach represents a significant advancement in wireless communication technology, leveraging MI gain and an MI-based control system architecture to enhance performance across diverse frequency bands. The study investigates the impact of MI on modulation efficiency, presenting experimental results validating the feasibility and effectiveness of the proposed approach. The maximum MI gain by employing a 30 km fiber under MI is 18 dB, experimentally. Further optimization, achieved by increasing the fiber length to 45 km and adjusting nonlinear parameters and input power, demonstrates a remarkable MI gain of 38.1 dB. MIbased true time delay (TTD) techniques also address beam squint challenges, enhancing beamforming capabilities. The findings suggest that integrating MI into RoF systems holds excellent potential for improving wireless communication capabilities with reduced costs and space requirements compared to conventional methods. This research contributes to the growing body of knowledge in the field of RoF systems and offers insights into their practical applications in modern wireless communication networks.
Multi-factor fuzzy sets decision system forecasting consumer insolvency risk
- Tomasz Korol
2024 Decision
The objective of this study is to develop a multi-factor decision system predicting insolvency risk for natural persons with the use of fuzzy sets. Considering that the financial situation of households is affected by various endogenous and exogenous factors, the main assumption of this study is that the system for predicting financial difficulties should not be limited to the use of only a few financial variables concerning consumers, but also include variables describing the environment. The author proposes a system consisting of three different forecasting models that connect the macroeconomic and microeconomic environments. It monitors the economic situation of households by also identifying those environmental variables, which may directly, or indirectly, endanger the consumer, such as unemployment rate (job market situation), inflation and interest rates, exchange rates, or economic situation in the country (GDP growth rate, the dynamics of retail sales, etc.). Moreover, the created multi-factor tool is in the form of a flexible application that can be easily adapted to changing economic conditions. Another unique feature of the study is the proposed use of newly developed ratios in household finance, similar to that in financial ratio analysis, which is commonly used in corporate finance. The proposed ratios demonstrated high predictive abilities. The paper also identifies the predictive capabilities of selected macroeconomic variables from the perspective of their impact on the risk of consumer insolvency. The research relies on four samples consisting of a total of 2,400 consumers from Taiwan and Poland. The author created three forecasting models separately for the South-East Asian and Central European regions, and two multi-factor systems, each consisting of 1260 decision rules. The findings clearly showed that a multi-factor system is a significantly more effective method compared to single forecasting models.
Multi-GPU UNRES for scalable coarse-grained simulations of very large protein systems
- Krzysztof Ocetkiewicz
- Cezary Czaplewski
- Henryk Krawczyk
- Agnieszka Lipska
- Adam Liwo
- Jerzy Proficz
- Adam K. Sieradzan
- Paweł Czarnul
2024 COMPUTER PHYSICS COMMUNICATIONS
Graphical Processor Units (GPUs) are nowadays widely used in all-atom molecular simulations because of the advantage of efficient partitioning of atom pairs between the kernels to compute the contributions to energy and forces, thus enabling the treatment of very large systems. Extension of time- and size-scale of computations is also sought through the development of coarse-grained (CG) models, in which atoms are merged into extended interaction sites. Implementation of CG codes on the GPUs, particularly the multiple-GPU platforms is, however, a challenge due to more complicated potentials and removing the explicit solvent, forcing developers to do interaction- rather than space-domain decomposition. In this paper, we propose a design of a multi-GPU coarse-grained simulator and report the implementation of the heavily coarse-grained physics-based UNited RESidue (UNRES) model of polypeptide chains. By moving all computations to GPUs and keeping the communication with CPUs to a minimum, we managed to achieve almost 5-fold speed-up with 8 A100 GPU accelerators for systems with over 200,000 amino-acid residues, this result making UNRES the best scalable coarse-grained software and enabling us to do laboratory-time millisecond-scale simulations of such cell components as tubulin within days of wall-clock time.
Multi-GPU-powered UNRES package for physics-based coarse-grained simulations of structure, dynamics, and thermodynamics of protein systems at biological size- and timescales
- Cezary Czaplewski
- Paweł Czarnul
- Henryk Krawczyk
- Agnieszka Lipska
- Emilia Lubecka
- Krzysztof Ocetkiewicz
- Jerzy Proficz
- Adam Sieradzan
- Rafał Ślusarz
- Józef Liwo
2024 BIOPHYSICAL JOURNAL
Coarse-grained models are nowadays extensively used in biomolecular simulations owing to the tremendous extension of size- and time-scale of simulations. The physics-based UNRES (UNited RESidue) model of proteins developed in our laboratory has only two interaction sites per amino-acid residue (united peptide groups and united side chains) and implicit solvent. However, owing to rigorous physics-based derivation, which enabled us to embed atomic details in the energy function, it is able to model the structures, dynamics, and thermodynamics of protein systems at good accuracy without ancillary information from structural databases. The UNRES package is an implementation of the UNRES model and uses Langevin molecular dynamics and its extensions for conformational search. It can be applied in both unrestrained simulations and those with restraints from experimental data or bioinformatics models. The package has been heavily optimized for memory and parallel performance using the message passing interface (MPI) and OpenMP libraries. Further, a GPU (graphical processor unit) and a well-scalable multiple-GPU version have been developed, thus enabling us to reach about 1 ms laboratory time in 1 day of computations for a chunk of tubulin comprising 234,260 amino-acid residues. In this communication the recent developments of the UNRES package will be presented and illustrated with appropriate examples including the simulations of (i) the dynamics of human norovirus variants, (ii) the dynamics of kinesin binding to tubulin, (iii) the conversion of thermal energy into net rotational motion by selected molecular rotatory motors, (iv) prediction of the structures of proteins and protein assemblies in recent CASP/CAPRI experiments and (iv) determination of protein structures at coarse-grained level using ambiguous NMR data. The optimized UNRES package is available from www.unres.pl and https://projects.task.gda.pl/eurohpcpl-public/unres.
Multi-instrument analysis of L-band amplitude scintillation observed over the Eastern Arabian Peninsula
- Abdollah Masoud Darya
- Muhammad Mubasshir Shaikh
- Grzegorz Nykiel
- Essam Ghamry
- Ilias Fernini
2024 ADVANCES IN SPACE RESEARCH
The study of scintillation-causing ionospheric irregularities is important to mitigate their effects on satellite communications. It is also important due to the spatial and temporal variability of these irregularities, given that their characteristics differ from one region to another. This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern Arabian Peninsula during the ascending phase of solar cycle 25 (years 2020–2023). The temporal occurrences of weak and strong scintillation were separated by sunset, with weak scintillation observed predominantly pre-sunset during the winter solstice and strong scintillation observed mainly post-sunset during the autumnal equinox. Strong scintillation was much more pronounced in 2023 compared to the other three years, indicating a strong influence of solar activity. Spatially, weak-scintillation-causing irregularities exhibited a wide distribution in azimuth and elevation, while strong-scintillation-causing irregularities were concentrated southwards. The combined analysis of S4 and rate of total electron content index (ROTI) suggested that small-scale ionospheric irregularities were present in both pre- and post-sunset periods, while large-scale irregularities were only seen during the post-sunset period. Furthermore, the presence of southward traveling ionospheric disturbances (TIDs) during the 2023 autumnal equinox was confirmed with the total electron content anomaly (dTEC), while the Ionospheric Bubble Index (IBI) provided by the Swarm mission was unable to confirm the presence of equatorial plasma bubbles during the same period. Observations from the FORMOSAT-7/COSMIC-2 mission indicated that strong-scintillation-causing irregularities were more prevalent under the F2-layer peak, while the weak-scintillation-causing irregularities were mostly observed at the E-layer, F2-layer, and above the F2-layer. This study aims to contribute insights into the behavior of scintillation-causing ionospheric irregularities in the region, with implications for future research during the peak of the 25th solar cycle.
Multilayer coatings based on cerium oxide and manganese cobaltite spinel for Crofer22APU SOC interconnects
- Elisa Zanchi
- Justyna Ignaczak
- Grzegorz Cempura
- Sebastian Molin
- Aldo R. Boccaccini
- Federico Smeacetto
2024 MATERIALS LETTERS
The current state of the art steel interconnect coating materials are based on critical raw material - Co-oxide spinels. Replacing Co-oxide spinels with alternative, abundant materials can reduce the dependence on the critical raw materials. Cobalt-free coatings with the general formula Mn2-xCuFexO4, where x = 0, 0.1, 0.3, were electrophoretically deposited on a ferritic stainless-steel support and evaluated. Prior to deposition, the powders were prepared by a soft chemistry process and studied in terms of crystallographic phase analysis, electrical conductivity, thermal expansion, and sinterability behaviour. Coated steel samples were oxidised in an air atmosphere at 750 °C for 3000 h. In parallel, a state-of-the-art MnCo2O4 spinel oxide was tested as a reference. The coatings and oxide scale microstructures of the surfaces and cross-sections were examined by XRD, and SEM-EDX. TEM-EDX, XRF, and micro-XRD were also performed on the cross-section lamellae. The electrical properties of the steel-coating system were evaluated by Area Specific Resistance measurement. The results confirm that Mn–Cu–Fe oxides exhibit higher conductivity and lower TEC than Mn–Co oxide. Based on the obtained results, it might be concluded that the proposed coatings are a promising alternative to coatings that contain cobalt.
Multimodal analysis of traction forces and the temperature dynamics of living cells with a diamond-embedded substrate
- Tomasz Kołodziej
- Mariusz Mrózek
- Saravanan Sengottuvel
- Maciej Głowacki
- Mateusz Ficek
- Wojciech Gawlik
- Zenon Rajfur
- Adam M. Wojciechowski
2024 Pełny tekst Biomedical Optics Express
Cells and tissues are constantly exposed to chemical and physical signals that regulate physiological and pathological processes. This study explores the integration of two biophysical methods: traction force microscopy (TFM) and optically detected magnetic resonance (ODMR) to concurrently assess cellular traction forces and the local relative temperature. We present a novel elastic substrate with embedded nitrogen-vacancy microdiamonds that facilitate ODMR-TFM measurements. Optimization efforts focused on minimizing sample illumination and experiment duration to mitigate biological perturbations. Our hybrid ODMR-TFM technique yields TFM maps and achieves approximately 1 K precision in relative temperature measurements. Our setup employs a simple wide-field fluorescence microscope with standard components, demonstrating the feasibility of the proposed technique in life science laboratories. By elucidating the physical aspects of cellular behavior beyond the existing methods, this approach opens avenues for a deeper understanding of cellular processes and may inspire the development of diverse biomedical applications.
Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
- Tadele Ayana
- Marcin Morawiec
- Lelisa Wogi
2024 Pełny tekst IEEE Access
Based on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed controller. The machine state variables are involved in flux generation and speed control rules. The performance of the proposed control strategy is formally studied by simulation and demonstrated through experiments. The technique exhibits fast convergence to the optimal flux level, reduces computational resource requirements, and enhances torque production and loss minimization accuracy. It eliminates the excessive flux demands compared to open-loop steady-state values, which will necessitate greater current levels without justification, resulting in an increased power dissipated. This optimum flux level minimizes induction motor losses for efficiency increments.
Multi-Taper-Based Automatic Correction of Non-Anechoic Antenna Measurements
- Mariusz Dzwonkowski
- Vorya Waladi
- Adrian Bekasiewicz
2024 Pełny tekst METROLOGIA
Prototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed in non-anechoic conditions and then refined using appropriate correction algorithms. Unfortunately, the existing post-processing methods suffer from multiple challenges that include manual setup of parameters as well as validation of performance in idealized conditions. In this communication, a multi-taper-based framework for correction of antenna characteristics obtained in non-anechoic environments has been proposed. The algorithm augments one-shot measurements of the structure under test in order to extract the line-of-sight responses while attenuating the interferences pertinent to multi-path propagation and noise from external sources of radiation. The performance of the proposed correction routine has been demonstrated in two test sites using a geometrically small Vivaldi radiator and validated against state-of-the-art techniques from the literature. The uncertainty budget for the measurements performed using the approach amounts to 0.26 dB, which is low given challenging propagation conditions considered for experiments.
Multitaper-Based Post-processing of Compact Antenna Responses Obtained in Non-anechoic Conditions
- Mariusz Dzwonkowski
- Adrian Bekasiewicz
- Sławomir Kozieł
2024
The process of developing antenna structures typically involves prototype measurements. While accurate validation of far-field performance can be performed in dedicated facilities like anechoic chambers, high cost of construction and maintenance might not justify their use for teaching, or low-budget research scenarios. Non-anechoic experiments provide a cost-effective alternative, however the performance metrics obtained in such conditions require appropriate correction. In this paper, we consider a multitaper approach for post-processing antenna far-field characteristics measured in challenging, non-anechoic environments. The discussed algorithm enhances one-shot measurements to enable extraction of line-of-sight responses while attenuating interferences from multi-path propagation and the noise from external sources of electromagnetic radiation. The performance of the considered method has been demonstrated in uncontrolled conditions using a compact spline-based monopole. Furthermore, the approach has been favorably validated against the state-of-the-art techniques from the literature.
MXene-based composites for capacitive deionization – The advantages, progress, and their role in desalination - A review
- Bakhtiar Ali Samejo
- Kainat Naseer
- Suraya Samejo
- Farooque Janjhi
- Najma Memon
- Roberto Castro Munoz
- Grzegorz Boczkaj
2024 Pełny tekst Water Resources and Industry
MXenes, a novel large family of 2D transition metal carbides, carbonitrides and nitrides are currently a “hot topic” in science due to their several fascinating physical and chemical properties. It follows from a rich diversity of their elemental compositions and chemical functionalities. MXenes can form composites with many substances, including polymers or metal oxides, which allows to effective “tune” MXene characteristics to a fit-to-the-purpose applications. Capacitive deionization (CDI) is currently widely studied as advanced desalination technique due to the advantages of cost-effectiveness, eco-friendly, and high salt removal capacity. One of key fields for CDI development relates to the ion's intercalation materials as concept taken from the sodium ion batteries, which is used in CDI because of their excellent desalination capacity. These materials provide effective sodium ions removal from the brine based on intercalation mechanism as well as redox reactions. In this review, we timely review an up-to-date accomplishment in the advancement of distinct MXene-based composite materials used as CDI electrodes, along with discussion of fundamental electrochemical energy storage mechanisms. The most relevant outcomes are highlighted together with the phenomena observed when applied in desalination applications. Finally, potential solutions as well as challenges in this field are summarized.
Nadmiarowe zgony podczas pandemii COVID-19 w Polsce i ocena skuteczności szczepień
- Błażej Kochański
- Jakub Sochacki
2024 Pełny tekst Wiadomości Statystyczne
Z powodu pandemii COVID-19 zmarły miliony ludzi na całym świecie. Jak wynika z wielu badań, szczepienia przeciw chorobie wywołanej wirusem SARS-CoV-2 okazały się środ-kiem ograniczającym skalę zachorowań i liczbę zgonów. Celem badania omawianego w artyku-le jest pomiar skali pandemii w Polsce za pomocą liczby nadmiarowych zgonów w podregio-nach według klasyfikacji NUTS 3 i w grupach wieku, a następnie określenie zależności pomiędzy zróżnicowaniem regionalnym względnej nadwyżki zgonów podczas czwartej fali pandemii a stopniem zaszczepienia populacji. Nadmiarowe zgony są rozumiane jako nadwyżka zgonów zarejestrowanych w stosunku do przewidywanego poziomu. Badaniem objęto okres od marca 2020 r. do lutego 2022 r. Korzystano z zasobów Eurostatu i Głównego Urzędu Statystycznego oraz danych pobranych z rządowego portalu Otwarte Dane. Analiza liczby nadmiarowych zgonów w podziale na grupy wieku wskazuje, że niemal 90% to zgony osób starszych (w wieku 60 lat i więcej). Z kolei pomiar w podziale na podregiony pozwala stwierdzić, że korelacja nadmiarowych zgonów i udziału zaszczepionych jest ujemna i dość silna. Przy założeniu występowania prostej regresji liniowej okazuje się, że dodatkowy 1% osób zaszczepionych w starszych grupach wieku przełożyłby się średnio na spadek liczby zgonów podczas czwartej fali pandemii o blisko 2000 w skali kraju. Ten wynik świadczy o tym, że szczepienia przeciw COVID-19 były skuteczne w zapobieganiu zgonom z powodu tej choro-by wśród osób starszych.
Nadzór i monitorowanie dostępności ZIntegrowanych Węzłów Przesiadkowych
- Marcin Budzyński
- Tomasz Mackun
- Jacek Szmagliński
- Romanika Okraszewska
- Kazimierz Jamroz
- Lech Michalski
- Joanna Wachnicka
2024
Audyt dostępności dla planowanych, projektowanych i istniejących węzłów przesiadkowych musi być przeprowadzony w kontekście społecznym i prawnym, w którym re- alizowany jest projekt. W Polsce prawa osób z niepełnosprawnościami reguluje m.in. ustawa z dnia 19 sierpnia 1997 r. o rehabilitacji zawodowej i społecznej oraz zatrudnianiu osób niepełnosprawnych oraz ustawa z dnia 27 sierpnia 1997 r. o rehabilitacji społecznej i zawodowej oraz zatrudnianiu osób niepełnosprawnych. Obie ustawy określają prawa osób z niepełnosprawnościami, m.in. w zakresie dostępności do budynków i urządzeń użyteczności publicznej. Ponadto w Polsce obowiązuje ustawa z dnia 19 lipca 2019 r. o zapewnieniu dostępności osobom ze szczególnymi potrzebami. Ustawa ta nakłada na podmioty publiczne i prywatne obowiązek zapewnienia dostępności swoich usług, w tym węzłów przesiadkowych, dla osób o szczególnych potrzebach. W kontekście społecznym należy zwrócić uwagę na fakt, że osoby z niepełnosprawnościami stanowią znaczącą część społeczeństwa. Z danych Głównego Urzędu Statystycznego wynika, że w Polsce mieszka około 4,5 mln osób z niepełnosprawnościami. Dlatego projektowanie węzłów przesiadkowych musi uwzględniać potrzeby tej grupy osób. Warto również zwrócić uwagę na fakt, że projektowanie węzłów przesiadkowych i ich przekształcanie z myślą o dostępności dla osób o szczególnych potrzebach może wpłynąć pozytywnie na poprawę jakości życia całego społeczeństwa. Dostępność do transportu publicznego dla osób z niepełnosprawnościami może przyczynić się do zwiększenia ich aktywności i integracji ze społeczeństwem. W kontekście społecznym i prawnym audyt dostępności dla węzłów przesiadkowych jest nie tylko konieczny, ale również pozytywnie wpłynie na poprawę jakości życia osób z niepełnosprawnościami oraz całego społeczeństwa.
Nanofiltration-Assisted Concentration Processes of Phenolic Fractions and Carotenoids from Natural Food Matrices
- Roberto Castro Munoz
2024 Pełny tekst Separations
In new food formulations, carotenoids and phenolic compounds are likely to be the most sought after food ingredients according to their bioactivity, nutraceutical, nutritional value, and compatibility properties once incorporated into food formulations. Such solutes are naturally present in many plant-based sources, and some portions are directly consumed when enriching food products and formulations; however, some portions, which are contained in the parts of the plant sources not considered edible, including the leaves, peel, and seeds, among other by-products, are commonly wasted. Related to this, scientists have found a new window for obtaining these bioactive molecules, but their recovery remains a challenge. To some extent, the final purification and polishing requires highly selective performance to guarantee the desired properties and concentration. In this regard, membrane technologies, such as nanofiltration (NF), represent an alternative, owing to their highly selective properties when separating low-molecular-weight compounds. NF becomes immediately suitable when the pretreated extracts are subjected to further efficient concentration, fractionation, and polishing of phenolic fractions and carotenoids. The separation efficiency (usually higher than 97%) of NF technology is high according to the low pore size of NF membranes, but the low temperature in process separation also contributes to the separation of thermolabile compounds. Therefore, this paper reviews the ongoing cases of studies reporting the successful separation and polishing of phenolic fractions and carotenoids from distinct sources. In particular, we have focused our attention on the main interactions during the separation process and the drawbacks and advantages of using membranes for such a case study.
Nanokrystaliczne tlenki metali jako katalizatory reakcji wydzielania tlenu w środowisku zasadowym
- Krystian Lankauf
2024 Pełny tekst
W pracy poruszona została tematyka opracowania oraz zastosowania nanokrystalicznych tlenków metali jako katalizatorów reakcji wydzielania tlenu w elektrolicie zasadowym, tj. jednej z reakcji zachodzących podczas elektrolizy wody. Szczególną uwagę poświęcono tlenkom o strukturze spinelu i perowskitu, które znane są z wyjątkowych właściwości elektrycznych, magnetycznych, optycznych oraz katalitycznych. Materiały zostały przygotowane za pomocą metody zol żel lub wysokotemperaturowej syntezy w fazie stałej. Podjęte zostały próby modyfikacji materiałów poprzez wprowadzenie nowych pierwiastków do struktury krystalicznej czy zastosowanie dodatkowej obróbki cieplnej (wyżarzanie) lub mechanicznej (mielenie) w celu poprawy parametrów pracy katalizatora. Przeprowadzone zostały badania strukturalne za pomocą technik mikroskopowych i spektroskopowych, natomiast aktywność elektrokatalityczna była analizowana korzystając z pomiarów elektrochemicznych takich jak woltamperometria cykliczna czy elektrochemiczna spektroskopia i
Nanomateriały o właściwościach magnetycznych, fotokatalitycznych, biobójczych
- Izabela Malinowska
2024 Pełny tekst
Tematyka badawcza pracy doktorskiej obejmuje preparatykę i charakterystykę nanomateriałów o właściwościach magnetycznych, fotokatalitycznych, biobójczych. Celem pracy była preparatyka nanomateriałów na bazie TiO2 oraz ZnFe2O4 oraz zastosowanie nanokompozytów w fotokatalizie heterogenicznej do degradacji ksenobiotyków niepodatnych na rozkład biologiczny i otrzymywania funkcjonalnych materiałów budowlanych. Otrzymane nanokompozyty scharakteryzowano za pomocą analizy powierzchni właściwej BET wraz z objętością porów, analizy rentgenograficznej XRD, analizy pętli histerezy magnetycznej oraz analizy mikroskopii elektronowej STEM. Otrzymane nanomateriały charakteryzują się właściwościami magnetycznymi, fotokatalitycznymi, biobójczymi. Taka hybrydowość właściwości pozwala na zastosowanie opisywanych materiałów jako fotokatalizatorów oraz dodatków do powszechnie znanych powłok ochronno-dekoracyjnych w celu nadania im nowych hybrydowych właściwości.
Nanoparticle-assisted biohydrogen production from pretreated food industry wastewater sludge: Microbial community shifts in batch and continuous processes
- Mohamed Saad Hellal
- Filip Gamoń
- Grzegorz Cema
- Gamal K. Hassan
- Ginedy Mohamed Gehad
- Aleksandra Ziembińska-Buczyńska
2024 ENERGY CONVERSION AND MANAGEMENT
Biohydrogen production from industrial waste has gained a significant attention as a sustainable energy source. In this study, the enrichment of biohydrogen production from pretreated dissolved air flotation (DAF) sludge, generated from food industry wastewater treatment plants, was investigated using SiO2@Cu-Ag dendrites cor- e–shell nanostructure (NS). The effect of NS on the changes of the microbial community and biohydrogen yield was evaluated through batch and continuous tests. In batch mode, various nanomaterial doses were investigated with several concentrations ranging from 20 to 50 mg/L for hydrogen production using glucose as a substrate. The optimum core–shell NS amount was 40 mg/L, achieving a maximum H2 yield of 163 mL/g volatile solids (VS) compared to the control’s 79 mL/g VS. However, 50 mg/L NS inhibited most bacteria in the sludge. The continuous experiment used a continuous stirring tank reactor (CSTR) with 40 mg/L SiO2@Cu-Ag core–shell NS and pretreated industrial sludge as substrate. The H2 yield increased to 115 L/kg VS compared to the control reactor’s 89 L/kg VS. The gas analysis showed compositional proportions of 83 % H2, 7 % CO2, and 4.5 % methane, while the microbial community analysis indicated the development of hydrogen-producing species such as Clostridium. In conclusion, SiO2@Cu-Ag core–shell NS addition enhanced anaerobic degradation of organic matter and its conversion to biohydrogen. The selected nanomaterial can be used for an effective continuous treatment system for industrial sludge while promoting dark fermentation.
Napęd z silnikiem indukcyjnym i 4-gałęziowym falownikiem SiC do turbosprężarek powietrza ogniw paliwowych dużej mocy
- Marek Adamowicz
- Sebastian Giziewski
2024 Pełny tekst Przegląd Elektrotechniczny
Wysoka cena ogniw paliwowych utrudnia ich szerokie zastosowanie w transporcie i przemyśle. Należy szukać możliwości obniżenia ich kosztu również poprzez obniżenie kosztu i zwiększenie wydajności urządzeń pomocniczych ogniwa paliwowego (Balance of the Plant). Autorzy proponują aby w napędzie sprężarki powietrza, zastosować wysokoobrotowy silnik indukcyjny, który jest tańszy od stosowanych obecnie silników PMSM. W referacie zaproponowano napęd z czterogałęziowym falownikiem SiC i wysokoobrotowym silnikiem indukcyjnym o mocy 6,3 kW, prędkości obrotowej 79 800 obr/min i częstotliwości zasilania 2667 Hz, który może być zastosowany do turbosprężarki powietrza ogniwa paliwowego o mocy 100 kW.
Natural/bio-based sorbents as greener extractive materials for endocrine disrupting compounds in samples of different matrix composition
- Justyna Płotka-Wasylka
- Aneta Chabowska
- Suwijak Pantanit
- Opas Bunkoed
- Michel Y. Fares
- Muhammad Sajid
- Dimitra Lambropoulou
- Aleksandra Kurowska-Susdorf
- Natalia Jatkowska
2024 Pełny tekst TRAC-TRENDS IN ANALYTICAL CHEMISTRY
Endocrine-disrupting compounds (EDCs) are a group of chemicals that interfere with the endocrine system, leading to adverse effects on human health and the environment. Increasing concerns over the EDCs presence in various environmental compartments has driven the search for greener extraction materials. Recently, the use of polymers of natural origin (biopolymers) has been demonstrated to be an effective and promising research direction due to their undeniable advantages over synthetic polymers. In this review, strategies for cellulose, chitin, and chitosan functionalization and their applicability for numerous microextraction techniques have been widely discussed. Following the trend related to the reuse of waste, various agricultural wastes that were employed for the isolation and enrichment of EDCs are described. The benefits and limitations of using natural sorbents have been highlighted.
Nature-Inspired Driven Deep-AI Algorithms for Wind Speed Prediction
- Muhammad Dilshad Sabir
- Laiq Khan
- Kamran Hafeez
- Zahid Ullah
- Stanisław Czapp
2024 Pełny tekst IEEE Access
Predicting wind energy production accurately is crucial for enhancing grid management and dispatching capacity. However, the inherent unpredictability of wind speed poses significant challenges to achieving high prediction accuracy. To address this challenge, this study introduces a novel pre-processing framework that leverages thirteen nature-inspired optimization algorithms to extract and combine Intrinsic Mode Functions (IMFs) of atmospheric and wind speed variables. The objective function ensures that the selected IMF combinations exhibit high correlation, enhancing their predictive relevance. The outputs of these algorithms are further refined using the proposed Optimal Search IMF (OAIMF) algorithm, which reduces redundancy and selects a minimal yet highly relevant set of IMF combinations for wind speed prediction. The methodology was validated through a case study conducted at the Climate, Energy, and Water Research Institute (CEWRI), NARC, Islamabad, Pakistan, leveraging real-world atmospheric data. Experimental results demonstrate that the proposed framework significantly outperforms direct prediction methods and state-of-the-art pre-processing techniques. For instance, the framework achieved an RMSE of 2.73 on an LSTM network and 3.86 on a GRU network, compared to RMSE values of 19.78 and 18.89, respectively, for direct prediction. Superior performance was also observed across MAE, MAPE, and R2 metrics. This study highlights the critical role of robust pre-processing in enhancing deep learning-based wind speed prediction. By integrating nature-inspired optimization with a novel IMF selection strategy, the proposed approach advances the state-of-the-art in renewable energy forecasting.