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  • MagMax: Leveraging Model Merging for Seamless Continual Learning
    • Daniel Marczak
    • Bartłomiej Twardowski
    • Tomasz Trzciński
    • Sebastian Cygert
    2024

    This paper introduces a continual learning approach named MagMax, which utilizes model merging to enable large pre-trained models to continuously learn from new data without forgetting previously acquired knowledge. Distinct from traditional continual learning methods that aim to reduce forgetting during task training, MagMax combines sequential fine-tuning with a maximum magnitude weight selection for effective knowledge integration across tasks. Our initial contribution is an extensive examination of model merging techniques, revealing that simple approaches like weight averaging and random weight selection surprisingly hold up well in various continual learning contexts. More importantly, we present MagMax, a novel model-merging strategy that enables continual learning of large pre-trained models for successive tasks. Our thorough evaluation demonstrates the superiority of MagMax in various scenarios, including class- and domain-incremental learning settings. The code is available on github.

  • Magnetic field mapping along a NV-rich nanodiamond-doped fiber
    • Adam Filipkowski
    • Mariusz Mrózek
    • Grzegorz Stępniewski
    • Mateusz Ficek
    • Dariusz Pysz
    • Wojciech Gawlik
    • Ryszard Buczyński
    • Adam M. Wojciechowski
    • Mariusz Klimczak
    2024 APPLIED PHYSICS LETTERS

    Integration of NV−-rich diamond with optical fibers enables guiding quantum information on the spin state of the NV− color center. Diamond-functionalized optical fiber sensors have been demonstrated with impressive sub-nanotesla magnetic field sensitivities over localized magnetic field sources, but their potential for distributed sensing remains unexplored. The volumetric incorporation of diamonds into the optical fiber core allows developing fibers sensitive to the magnetic field over their entire length. Theoretically, this makes distributed optical readout of small magnetic fields possible, but does not answer questions on the addressing of the spatial coordinate, i.e., the location of the field source, nor on the performance of a sensor where the NV− fluorescence is detected at one end, thereby integrating over color centers experiencing different field strength and microwave perturbation. Here, we demonstrate distributed magnetic field measurements using a step-index fiber with the optical core volumetrically functionalized with NV− diamonds. A microwave antenna on a translation stage is scanned along a 13 cm long section of a straight fiber. The NV− fluorescence is collected at the fiber's far end relative to the laser pump input end. Optically detected magnetic resonance spectra were recorded at the fiber output for every step of the antenna travel, revealing the magnetic field evolution along the fiber and indicating the magnetic field source location. The longitudinal distribution of the magnetic field along the fiber is detected with high accuracy. The simplicity of the demonstrated sensor would be useful for, e.g., magnetic-field mapping of photonics- and/or spintronics-based integrated circuits.

  • Magnetic hydrophobic deep eutectic solvents for orbital shaker-assisted dispersive liquid-liquid microextraction (MAGDES-OS-DLLME) - determination of nickel and copper in food and water samples by FAAS
    • Adil Elik
    • Hameed Haq
    • Grzegorz Boczkaj
    • Seçkin Fesliyan
    • Özlem Ablak
    • Nail Altunay
    2024 Pełny tekst JOURNAL OF FOOD COMPOSITION AND ANALYSIS

    In this work, a cheap and widely applicable dispersive liquid-liquid microextraction (DLLME) method was developed for the extraction of Ni(II) and Cu(II) from water and food samples and analysis using flame atomic absorption spectrometry. DLLME was assisted by orbital shaker, while ferrofluid as an extractant was based on deep eutectic solvent (DES). This ferrofluid was made of hydrophobic DES (hDES), composed of lauric acid and menthol (molar ratio 1:2), and toner powder@aliquat 336 magnetic particles. The extraction procedure does not require any heating or centrifugation. The method limits of detection value were 0.15 µg L−1 and 0.03 µg L−1 for Ni(II) and Cu(II) respectively along with wide linearity range (0.4–250 µg L−1). The validation of the method was performed using certified reference materials (CRMs). The studies revealed excellent accuracy between results obtained by the developed method and expected values for all CRMs. The relative recoveries of Ni(II) and Cu(II) ions ranged from 92.8% to 98.6%. The developed method was further used for the determination of Ni(II) and Cu(II) in real water and food samples and provided quantitative recoveries.

  • Magnetic Porous Material Derived from Ni-MOF for the Removal of Tetracycline from Aqueous Solution
    • Yuhui Xue
    • Jingjing Wang
    • Mengjie Wang
    • Jiang Li
    • Kefu Wang
    • Afaq Hassan
    • Changyan Guo
    • Jide Wang
    2024 ACS Applied Nano Materials

    The efficient removal of antibiotic residues from aqueous solution is very important for water security. Studies have found that adsorption is widely used for the removal of antibiotics due to its cost-effectiveness, low energy consumption, simplicity of operation, and environmental friendliness. In this study, a novel magnetic porous carbon adsorbent (Ni-MPC-400) with a high adsorption capacity and saturation magnetization was synthesized via direct carbonization of Ni-MOF at 400 °C pyrolysis temperature and used to efficiently remove tetracycline from an aqueous solution. Adsorption experiments showed that Ni-MPC-400 exhibited excellent tetracycline adsorption capacity (441.51 mg·g–1) from the aqueous solution. Possible adsorption mechanisms were proposed through characterization and analysis. The adsorption mechanisms mainly involved π–π interactions, hydrogen bonding, metal–organic complexation, and pore filling effects. In addition, Ni-MPC-400 showed rapid and sufficient adsorption at a low concentration of tetracycline (5 mg·L–1) and good adsorption performance over a wide pH range. In addition, the material has been tested to have good immunity to interference and regenerative capacity, demonstrating a potential application in the removal of tetracycline contaminants from aqueous solutions.

  • Magnetic superhydrophobic melamine sponges for crude oil removal from water
    • Patrycja Makoś-Chełstowska
    • Edyta Słupek
    • Aleksandra Mielewczyk-Gryń
    • Tomasz Klimczuk
    2024 CHEMOSPHERE

    This paper proposes the preparation of a new sorbent material based on melamine sponges (MS) with superhydrophobic, superoleophilic, and magnetic properties. This study involved impregnating the surface of commercially available MS with eco-friendly deep eutectic solvents (DES) and Fe3O4 nanoparticles. The DES selection was based on the screening of 105 eutectic mixtures using COSMO-RS modeling. Other parameters affecting the efficiency and selectivity of oil removal from water were optimized using the Box-Bhenken model. Menthol:Thymol (1:1)@Fe3O4-MS exhibited the highest sorption capacity for real crude oils (101.7–127.3 g/g). This new sponge demonstrated paramagnetic behavior (31.06 emu/g), superhydrophobicity (151°), superoleophobicity (0°), low density (15.6 mg/cm3), high porosity (99 %), and excellent mechanical stability. Furthermore, it allows multiple regeneration processes without losing its sorption capacity. Based on these benefits, Menthol:Thymol (1:1)@Fe3O4-MS shows promise as an efficient, cost-effective, and eco-friendly substitute for the existing sorbents.

  • Magnetyczne i elektromagnetyczne uchwyty obróbkowe - konstrukcja i rozwój
    • Adam Barylski
    2024 Kwartalnik Naukowo-Techniczny "Obróbka Metalu"

    Przedstawiono współczesne rozwiązania konstrukcyjne obróbkowych uchwytów magnetycznych i elektromagnetycznych. Podano przykłady zastosowania w operacjach obróbki wiórowej i ściernej oraz w różnorodnych procesach spawania. Omówiono ważniejsze zalecenia technologiczne oraz ograniczenia praktyczne.

  • MAKSYMALIZACJA WYTRZYMAŁOŚCI NA OBCIĄŻENIE OSIOWE BUTELEK PET Z PUNKTU WIDZENIA ICH TRANSPORTU
    • Waldemar Karaszewski
    • Rafał Gawarkiewicz
    • Paweł Wawrzyniak
    2024 Przemysł Chemiczny

    Przewóz opakowań PET na paletach obarczony jest coraz większym ryzykiem ich odkształcania się pod wpływem obciążenia masą kolejnych warstw butelek. Doświadczenie pokazuje, że w transporcie opakowań PET o dużej objętości (5-6 litrów) decydującym elementem jest wytrzymałość osiowa górnej części opakowania. W artykule omówiono wybrane wyniki z szeroko przeprowadzonych analiz numerycznych wykonanych w celu określenia kształtu górnej części butelki PET o możliwie największej wytrzymałości osiowej w warunkach obciążeń podczas transportu. Przyjęty model numeryczny zweryfikowano doświadczalnie.

  • Management of Complex Root Fractures in Young Patients—Case Series and a Literature Review
    • Hanna Sobczak-Zagalska
    • Dorota Ogonowska-Paul
    • Michał Bartmański
    • Paulina Adamska
    2024 Journal of Clinical Medicine

    Root fractures are defined as injuries involving dentine, cementum, and the pulp. They are rare, and they account for 0.5–7% of the dental injuries in the permanent teeth. Root fractures may be the result of direct trauma to the teeth or indirect trauma to the oral cavity. Their incidence is highest in the group of adolescent patients aged 11 to 20 years. The purpose of the paper is to review the literature supported by a case series with three different types of root fractures with various healing patterns, though all with successful long-term treatment outcomes. Case series: All presented patients were boys aged 10 to 11 years. Root fractures occurred as a result of direct impact with the teeth by an object. Only one boy had his root-fractured teeth endodontically treated. However, one of the teeth was misdiagnosed with pulp necrosis, and the other became non-vital after additional trauma. Conclusions: Root fractures in young patients have good healing potential. Appropriate and early diagnostic and therapeutic procedures for treating root-fractured teeth are necessary to achieve favorable healing and a good long-term prognosis. Regardless of the pattern of healing of fractured roots and the treatment provided, patients require long-term follow-up and the need to plan a management strategy in case complications occur. Failure of the healing of fractured root is a worst-case scenario, especially in patients of developmental age. In such cases, the primary goal of treatment is to preserve the alveolar ridge until growth is complete.

  • Management of energy renovation for traditional rural residential houses
    • Magdalena Szarejko
    2024 Budownictwo i Architektura

    Renowacja energetyczna ma na celu zmniejszenie energii zużywanej przez budynek poprzez poprawę właściwości cieplnych przegród budowlanych oraz usprawnienie efektywności systemów instalacyjnych. Jest to istotny element w osiąganiu celów klimatycznych zdefiniowanych przez społeczność międzynarodową. Renowacja zabudowy o wartości kulturowej wiąże się z koniecznością zachowania cech architektonicz- nych, decydujących o jej rozpoznawalności, co istotnie komplikuje i ogranicza dobór metod i środków. W Polsce proces ten polega najczęściej na niepełnej termomodernizacji uwzględniającej wybrane elementy budynku wraz z wymianą źródła ciepła. Efektem jest jedynie niewielkie zmniejszenie strat energii oraz znacząca utrata walorów architektonicznych. Przedmiotem badania jest ocena możliwości zastosowania kompleksowego zarządza- nia renowacją energetyczną na poziomie lokalnym, w celu poprawy ochrony i zachowania cech tradycyjnej ceglanej zabudowy, stanowiącej wyróżnik architektoniczny wsi pomor- skiej. Zaproponowano model zintegrowanego systemu zarządzania renowacją energetyczną budynku. Sięgnięto po funkcjonujące w Europie wzory rozwiązań, które przeanalizowano pod kątem możliwości dostosowania do krajowej specyfiki. Wskazano na złożoność problemu. Artykuł rekomenduje uwzględnienie całego cyklu życiowego budynku w procesie zarządzania renowacją: od wniosków z badania zastosowanych rozwiązań planistycznych, projektowych i wykonawczych po kontrolę efektów energetycznych w trakcie eksploatacji

  • Management of ground tire rubber waste by incorporation into polyurethane-based composite foams
    • Aleksander Hejna
    • Paulina Kosmela
    • Adam Olszewski
    • Łukasz Zedler
    • Krzysztof Formela
    • Katarzyna Skórczewska
    • Adam Piasecki
    • Mariusz Marć
    • Roman Barczewski
    • Mateusz Barczewski
    2024 Pełny tekst ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    Rapid economic growth implicated the developing multiple industry sectors, including the automotive branch, increasing waste generation since recycling and utilization methods have not been established simultaneously. A very severe threat is the generation of enormous amounts of post-consumer tires considered burdensome waste, e.g., due to the substantial emissions of volatile organic compounds (VOCs). Therefore, it is essential to develop novel, environmentally friendly methods for their utilization, which would hinder their environmental impacts. One of the most promising approaches is shredding, resulting in the generation of ground tire rubber (GTR), which can be introduced into polymeric materials as filler. The presented work is related to the thermomechanical treatment of GTR in a twin-screw extruder with zinc borate, whose incorporation is aimed to enhance shear forces within the extruder barrel. Modified GTR was introduced into flexible polyurethane (PU) foams, and the impact of modification parameters on the cellular structure, static and dynamic mechanical performance, thermal stability, as well as thermal insulation, and acoustic properties were investigated. Emissions of VOCs from applied fillers and prepared composites were monitored and evaluated. Depending on the treatment parameters, beneficial changes in foams’ cellular structure were noted, which enhanced their thermal insulation performance, mechanical strength, and thermal stability. It was proven that the proposed method of GTR thermomechanical treatment assisted by zinc borate particles might benefit the performance of flexible PU foamed composites and hinder VOCs emissions, which could broaden the application range of GTR and provide novel ways for its efficient utilization

  • Managing and funding the innovative path: a close look at the SimLE scientific club at Gdańsk University of Technology, Poland
    • Wiktor Sieklicki
    • Maciej Zawadzki
    2024 Global Journal of Engineering Education

    This article presents a case study of the simply learn experience (SimLE) scientific club at Gdańsk University of Technology (Gdańsk Tech), Gdańsk, Poland, showcasing an effective model for blending theoretical knowledge with practical engineering applications. This student-led organisation aims to develop soft skills and handson experience through project work, participation in international contests and conferences. This study examines the funding mechanisms, educational impacts and management strategies of competitive achievements within SimLE. The results show that the level of financial support moderately affects the output of academic publications. However, this support is crucial for enhancing international visibility and facilitating participation in academic conferences. Also, it directly correlates with students’ engagement. Importantly, the research reveals that variations in scientific output are more closely associated with the composition of teams and management approaches rather than the extent of financial backing

  • Managing knowledge in a tourism crisis: case study from Poland
    • Ewa Stolarek-Muszyńska
    • Małgorzata Zięba
    • Ettore Bolisani
    • Enrico Scarso
    2024 Pełny tekst

    Purpose: This study deals with a tourism organisation from Poland, which experienced not only the COVID-19 pandemic, but also the close war situation in Ukraine which caused a significant decrease in tourist traffic and revenues. Since, based on the literature, knowledge management can be useful for crisis management, this study aims to explore the role and usefulness of KM during crisis situations in tourism. Methodology: Qualitative in-depth analysis was conducted by using data collected via semi-structured interview with the CEO of a local tourism organisation in Poland. The research output is presented in the form of a single case study with that organisation as the unit of analysis. Findings: The case highlighted that: a) a crisis may not be the most appropriate time for the implementation of KM from the scratch in an organisation; b) having some minimal KM experience can be essential for a more structured and complex KM approach; c) organisations may benefit from lessons learned during the crisis to get insights for developing KM. These findings suggest that practitioners and policymakers facilitate KM awareness among tourism organisations to enhance resilience in coping with future crises. Research limitations: This is a single case study and thus it cannot be easily generalised or provide a comprehensive overview of the whole sector. It is also a case study from a single country, affected by two serious crises which limits the applicability of the results to other countries. Practical implications: The study provides useful insights for practitioners in tourism organisations aspiring to improve internal processes of knowledge management and thus mitigating the future tourism crises. Originality/value: This paper contributes to the body of knowledge in terms of the role and relevance of KM during the tourism crisis. It provides food for thought for researchers investigating the knowledge and crisis management processes within the tourism industry.

  • Mangiferin: A comprehensive review on its extraction, purification and uses in food systems
    • Roberto Castro Munoz
    • René Cabezas
    • Maksymilian Plata Gryl
    2024 ADVANCES IN COLLOID AND INTERFACE SCIENCE

    With the target of fabricating healthier products, food manufacturing companies look for natural-based nutraceuticals that can potentially improve the physicochemical properties of food systems while being nutritive to the consumer and providing additional health benefits (biological activities). In this regard, Mangiferin joins all these requirements as a potential nutraceutical, which is typically contained in Mangifera indica products and its by-products. Unfortunately, knowing the complex chemical composition of Mango and its by-products, the extraction and purification of Mangiferin remains a challenge. Therefore, this comprehensive review revises the main strategies proposed by scientists for the extraction and purification of Mangiferin. Importantly, this review identifies that there is no report reviewing and criticizing the literature in this field so far. Our attention has been targeted on the timely findings on the primary extraction techniques and the relevant insights into isolation and purification. Our discussion has emphasized the advantages and limitations of the proposed strategies, including solvents, extracting conditions and key interactions with the target xanthone. Additionally, we report the current research gaps in the field after analyzing the literature, as well as some examples of functional food products containing Mangiferin.

  • Marine polymers in tissue bioprinting: Current achievements and challenges
    • Adrianna Banach-Kopeć
    • Szymon Mania
    • Robert Tylingo
    2024 Pełny tekst REVIEWS ON ADVANCED MATERIALS SCIENCE

    Bioprinting has a critical role in tissue engineering, allowing the creation of sophisticated cellular scaffolds with high resolution, shape fidelity, and cell viability. Achieving these parameters remains a challenge, necessitating bioinks that are biocompatible, printable, and biodegradable. This review highlights the potential of marine-derived polymers and crosslinking techniques including mammalian collagen and gelatin along with their marine equivalents. While denaturation temperatures vary based on origin, warm-water fish collagen and gelatin emerge as promising solutions. Building on the applications of mammalian collagen and gelatin, this study investigates their marine counterparts. Diverse research groups present different perspectives on printability and cell survival. Despite advances, current scaffolds are limited in size and layers, making applications such as extensive skin burn treatment or tissue regeneration difficult. The authors argue for the development of bioprinting, which includes spherical and adaptive printing. In adaptive printing, layers differentiate and propagate sequentially to overcome the challenges of multilayer printing and provide optimal conditions for the growth of deeply embedded cells. Moving the boundaries of bioprinting, future prospects include transformative applications in regenerative medicine.

  • Maritime traffic situation awareness analysis via high-fidelity ship imaging trajectory
    • Xinqiang Chen
    • Jinbiao Zheng
    • Chaofeng Li
    • Bing Wu
    • Huafeng Wu
    • Jakub Montewka
    2024 MULTIMEDIA TOOLS AND APPLICATIONS

    Situation awareness provides crucial yet instant information to maritime traffic participants, and significant attentions are paid to implement traffic situation awareness task via various maritime data source (e.g., automatic identification system, maritime surveillance video, radar, etc.). The study aims to analyze traffic situation with the support of ship imaging trajectory. First, we employ the dark channel prior model to remove fog in maritime videos to obtain high-resolution ship images (i.e., fog-free maritime images). Second, we track ships in each maritime image with the scale adaptive kernel correlation filter (SAMF), and thus obtain raw ship imaging trajectories. Third, we cleanse abnormal ship trajectory samples via curve-fitting and down sampling method, and thus further maritime traffic situation analysis is implemented. We analyze maritime traffic situation in three typical videos (i.e., three typical maritime traffic scenarios), and experimental results suggested that the proposed framework can extract high-resolution ship imaging trajectory for fulfilling the task of accurate maritime traffic situation awareness.

  • MARS - BAZA. warsztaty pozaziemskiej architektury ekstremalnej. Warsztaty w ramach Bałtyckiego Festiwalu Nauki
    • Aleksandra Karpińska
    • Agnieszka Kurkowska
    • Marta Koperska-Kośmicka
    • Marcin Kulesza
    2024

    Jak przetrwać w różnych warunkach? Czego potrzebujemy, by przeżyć, a czego, by żyć wygodnie? Poszukamy odpowiedzi na te pytania, by stanąć przed nie lada misją: wspólnie podejmiemy się największego wyzwania przyszłości - zbudujemy bazę na Marsie! Budowa schronienia, bazy, domu - troska o zaspokojenie podstawowych potrzeb towarzyszy nam od zawsze, a budowanie jest jednym z pierwszych trwałych działań ludzi, pomagającym spełnić nasze potrzeby bytowe. Z innymi wyzwaniami stykamy się jednak, kiedy planujemy budować dom, a innymi, kiedy spotykamy się z warunkami ekstremalnymi, kiedy standardowe rozwiązania nie mają zastosowania. Lekcja myślenia o projektowaniu w warunkach ekstremalnych to wstęp do zadania praktycznego w nurcie dizajnu spekulatywnego: uczestnicy będą projektować i budować w skali 1:1 model własnej bazy na Marsie.

  • Materiałowe aspekty budowy narzędzi docierarek tarczowych do płaszczyzn
    • Adam Barylski
    2024 Inżynieria Materiałowa

    Przedstawiono problematykę doboru materiałów na narzędzia w operacjach docierania i szlifowania powierzchni na obrabiarkach tarczowych. Scharakteryzowano stosowane materiały na tego typu narzędzia oraz wybrane konstrukcje tarcz do obróbki elementów płaskich i płasko-równoległych. Wskazano na korzystne zastosowanie żeliw sferoidalnych w aspekcie aktywizacji powierzchni czynnej docieraków ścierniwem. Przedstawiono analizę modelową aktywizacji docieraków z niestopowego żeliwa sferoidalnego. Omówiono opracowane konstrukcje narzędzi ścierno-metalowych oraz porównano docieranie luźnym ścierniwem i szlifowanie ściernicami segmentowymi na docierarkach tarczowych.

  • MATRYCA. NANO – qual-IA.
    • Krzysztof Wróblewski
    2024

    Wystawa podejmie problem konstytuowania i określania stopnia „zrozumiałości” wypowiedzi artystycznych (w jej różnych formach). Punktem odniesienia dla powstałych prac są pojęcia matrycy społecznej oraz treści percepcyjnej. >>Jaka może być najmniejsza porcja informacji? Jaka może być najmniejsza porcja doświadczenia? << Nikt nie wie do czego funkcjonalnie służy świadomość. Super inteligencja umożliwia szybkie przetwarzanie danych (jak w AI), które jednak potrafi odbywać się bez udziału świadomości. Matryca (łac. mater– matka, ang - matrix) jest to ogólne określenie formy do wykonywania kopii. W biologii molekularnej „matryca” to fragment DNA, na którym odbywa się amplifikacja - proces, podczas którego dochodzi do zwielokrotniania liczby lub zwiększania ilości. Najczęściej termin ten jest stosowany w odniesieniu do powielania (namnażania) DNA w genomie. Zachodzi pod wpływem różnych hormonów, które regulują funkcjonowanie narządów organizmu. Można obserwować zwrotne oddziaływanie pomiędzy wydzielaniem hormonów a stanami psychicznymi wywołanymi w związku z doświadczaniem silnych emocji i uczuć. Odbiorczość (receptywność) i intencjonalność (ukierunkowane działanie) są ważnym elementem fenomenu qualiów - jednostek percepcyjnych właściwych człowiekowi. Rozważa się nawet możliwość, że ludzki umysł może łamać funkcję falową, tworzyć kolaps kwantowy i tym samym wpływać na „matrycę” podłoża świadomości (tego nie potrafi obliczeniowa sztuczna inteligencja). Brać jednak trzeba też pod uwagę ograniczone zdolności poznawcze człowieka - błędy poznawcze, przekonania fałszywe, idealizacje, uproszczenia, luki pamięciowe i w postrzeganiu. Jak owe braki miałyby wpływać na proces łamania funkcji kwantowej? Jak bardzo kreowana w umyśle utopia wpływać może na treści przeżycia a tym samym kształtować „ukierunkowaną” postawę i określać kontekst sensu? Qualia są dla percepcji niczym układ hormonalny w organizmie. Działaniowy i performatywny status przeżyć może w konsekwencji wpływać na charakter zaangażowania jednostki w społeczną matrycę wspólnotowego uczestnictwa. Czy owo uczestnictwo jest jednak wystarczające jako warunek zrozumiałości prezentowanej treści, choćby w wypowiedzi artystycznej? Koncepcja: Marek Rogulski TNS / ICS

  • Maximizing Bio-Hydrogen and Energy Yields Obtained in a Self-Fermented Anaerobic Bioreactor by Screening of Different Sewage Sludge Pretreatment Methods
    • Alaa A. El-kebeer
    • Usama F. Mahmoud
    • Sayed Ismail
    • Abu Abbas E. Jalal
    • Przemysław Kowal
    • Hussein Al-Hazmi
    • Gamal K. Hassan
    2024 Pełny tekst Processes

    Egypt faces significant challenges in managing its sewage sludge generated in large quantities from wastewater treatment plants. This study investigates the feasibility of utilizing sewage sludge as a renewable resource for hydrogen production through anaerobic digestion at the 100 L bioreactor level. Hydrogen is considered a promising alternative energy source due to its high energy content and environmental benefits. To optimize the microbial degradation process and maximize hydrogen production from sewage sludge, a specialized pretreatment is necessary. Various pretreatment methods have been applied to the sewage sludge, individually and in combination, to study the bio-hydrogen production from sewage sludge. The four methods of treatment were studied in batch assays as a pilot scale. Thermal pretreatment of sewage sludge significantly increases bio-hydrogen production yield compared to other sewage sludge pretreatment methods, producing the highest H2 yield (6.48 LH2/g VS). In general, the hydrogen yield of any type of pretreated inoculum was significantly higher than the untreated inoculum. At the same time, alkaline pretreatment improved the hydrogen yield (1.04 LH2/g VS) more than acid pretreatment (0.74 LH2/g VS), while the hydrogen yield for the combination of pretreatments (shock alkali pretreatment) was higher than both (1.73 LH2/g VS), On the other hand, untreated sewage sludge (control) had almost no hydrogen yield (0.03 LH2/g VS). The self-fermented anaerobic bioreactor improved sewage sludge utilization, increased bioenergy yields, and seems to be promising for treating complex wastes at this scale.

  • Maximizing SDN resilience to node‐targeted attacks through joint optimization of the primary and backup controllers placements
    • Michał Pióro
    • Mariusz Mycek
    • Artur Tomaszewski
    • Amaro de Sousa
    2024 Pełny tekst NETWORKS

    In Software Defined Networks (SDN) packet data switches are configured by a limited number of SDN controllers, which respond to queries for packet forwarding decisions from the switches. To enable optimal control of switches in real time the placement of controllers at network nodes must guarantee that the controller-to-controller and switch-to-controller communications delays are bounded. Apart from the primary controllers that control the switches in the nominal state, separate backup controllers can be introduced that take over when the primary controllers are unavailable, and whose delay bounds are relaxed. In this paper we present optimization models to jointly optimize the placement of primary and backup controllers in long-distance SDN networks, aimed at maximizing the network's resilience to node-targeted attacks. Applying the models to two well-known network topologies and running a broad numerical study we show that, when compared with the standard approach of using only primary controllers, the use of backup controllers provides significant resilience gains, in particular in case of strict delay bounds.