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  • Synthesis, photophysical characterisation, quantum-chemical study and in vitro antiproliferative activity of cyclometalated Ir(iii) complexes based on 3,5-dimethyl-1-phenyl-1H-pyrazole and N,N-donor ligands
    • Joanna Masternak
    • Karol Okła
    • Adam Kubas
    • Jiří Voller
    • Karolína Kozlanská
    • Małgorzata Zienkiewicz-Machnik
    • Agnieszka Gilewska
    • Jerzy Sitkowski
    • Anna Kamecka
    • Katarzyna Kazimierczuk
    • Barbara Barszcz
    2024 DALTON TRANSACTIONS

    In this paper, we present the synthesis of four new complexes: the dimeric precursor [Ir(dmppz)2(μ-Cl)]2 (1) (Hdmppz – 3,5-dimethyl-1-phenyl-1H-pyrazole) and heteroleptic bis-cyclometalated complexes: [Ir (dmppz)2 (Py2CO)]PF6 · 1 2 CH2 Cl2 (2), [Ir(dmppz)2 (H2biim)]PF6·H 2 O (3), and [Ir(dmppz)2 (PyBIm)]PF 6 (4), with auxiliary N,N-donor ligands: 2-di(pyridyl)ketone (Py2CO), 2,2’-biimidazole (H 2biim) and 2-(2’-pyridyl)ben- zimidazole (PyBIm). In the obtained complexes, SC-X-ray analysis revealed that Ir( III) has an octahedral coordination sphere with chromophores of the type {IrN2 C2Cl2 } (1) or {IrN 4C 2} (2–4). The complexes obtained, which have been fully characterised by physicochemical methods (CHN, TG, FTIR, UV-Vis, PL and 1 H, 13 C, 15 N NMR), were used to continue our studies on the factors influencing the cytotoxic pro- perties of potential chemotherapeutic agents (in vitro). To this end, the following studies are presented: (i) comparative analysis of the effects on the biological properties of N,N-donor ligands and C,N-donor ligands in the studied complexes, (ii) studies of the interactions of the compounds with the selected molecular target: DNA and BSA (UV-Vis, CD and PL methods), (iii) and the reactivity towards redox mole- cules: GSH, NADH (UV-Vis and/or ESI-MS methods), (iv) cytotoxic activity (IC50) of potential chemothera- peutics against MCF-7, K-562 and CCRF-CEM cell lines.

  • Synthesis, structure and luminescence properties of borate-bismuth glasses and glass-ceramics doped with rare earth ions
    • Karolina Milewska
    2024 Pełny tekst

    In a doctoral dissertation, new borate-bismuth glasses and glass-ceramics containing AlF3 and SrF2 were examined as potential hosts for RE3+ ions. Experimental studies were conducted to determine optimal conditions for synthesizing transparent borate-bismuth glasses and glass ceramics, with a focus on analyzing their structure and luminescence properties. The introduction of AlF3 into the glass matrix led to an increase in the luminescence intensity of RE3+ ions in glasses containing 10 mol% AlF3. It was observed that the emitted color could be adjusted by varying the ratios of RE3+ ions. In the study of glass-ceramic systems doped with SrF2, successful crystallization of SrF2 nanocrystals was achieved. Structural modifications of the parental glass, leading to SrF2 nanostructure crystallization, were found to depend strongly on the initial amount of strontium fluoride. An increase in luminescence intensity was observed after annealing in samples containing 20 mol% SrF2. Luminescence lifetimes indicated that some of the Eu3+ ions were located in SrF2 nanocrystals, which was further supported by analysis of Judd–Ofelt parameters and luminescence intensity ratio. The presented results suggest that the proposed glasses and glass ceramics could serve as suitable matrices for optically active RE3+ ions.

  • System oceny efektywności użytkowania aparatów słuchowych
    • Piotr Szymański
    2024 Pełny tekst

    Celem rozprawy jest opracowanie metody oceny efektywności protezowania słuchu przy użyciu aparatów słuchowych, która pozwoli w łatwy sposób poddawać ocenie korzyść z użytkowania protez słuchowych w najbardziej typowych sytuacjach akustycznych. Przedstawiono genezę podjętych badań i na tej podstawie zaproponowano cele i tezy rozprawy doktorskiej. W pracy w pierwszej kolejności zawarto przegląd dotyczący rodzajów ubytku słuchu i jego wpływu na jakość życia, rozwiązania wspomagające osoby z ubytkiem słuchu oraz stosowane metody oceny efektywności użytkowania aparatów słuchowych. Wybrane metody omówiono zgodnie ze stanem wiedzy, ze szczególnym uwzględnieniem kwestionariusza APHAB (Abbreviated Profile of Hearing Aid Benefit), który jest jedną z najważniejszych i najczęściej aktualnie stosowanych metod dopasowania aparatów słuchowych. W celu realizacji badań i zebrania danych przygotowano aplikację internetową, która została wdrożona w około 200 punktach protetycznych. Uzyskane dane poddano analizie statystycznej. Analiza wykorzystująca test MUSHRA (MUltiple Stimuli with Hidden Reference and Anchor) oraz wnioskowanie regułowe oparte na logice rozmytej stała się podstawą modyfikacji zaproponowanego systemu. We wnioskach odniesiono się do tez badawczych, wdrożenia zaproponowanej metody, jak również podano kierunki rozwoju prowadzonych badań.

  • System wizyjny dla robota łapiącego piłki
    • Bartosz Czaja
    • Marek Tatara
    • Jan M. Kelner
    2024 Elektronika : konstrukcje, technologie, zastosowania

    W niniejszej pracy zaproponowano i przetestowano system wizyjny służący śledzeniu lecącej piłki w celu wypracowania sterowania dla robota wieloosiowego mającego za zadanie złapanie jej. Do detekcji i lokalizacji piłki na obrazie z dwóch, prostopadle ustawionych, kamer zastosowano laplasjan filtru gaussowskiego (LoG) oraz autorski podsystem filtracji rozmytej. Estymację trajektorii lecącej piłki w przestrzeni wykonano w oparciu o metodę najmniejszych kwadratów z wykorzystaniem funkcji liniowej i kwadratowej. Zamieszczono szczegółowy opis proponowanego rozwiązania oraz wyniki przeprowadzonych testów.

  • Szlifowanie na docierarkach sposobem zmniejszenia skażenia powierzchni ziarnami ściernymi w obróbce wykończeniowej
    • Adam Barylski
    2024 Dozór Techniczny

    W artykule przedstawiono szkodliwość skażenia powierzchni mikroziarnami ściernymi w procesach docierania luźnym ścierniwem żeliwa szarego oraz sferoidalnego. Omówiono technologie szlifowania powierzchni płasko-równoległych z kinematyką docierania obiegowego, jako sposób zmniejszenia skażenia powierzchni ścierniwem po obróbce wykończeniowej.

  • Szlifowanie powierzchni płasko-równoległych z kinematyką docierania
    • Adam Barylski
    2024 Projektowanie i Konstrukcje Inżynierskie

    Przedstawiono charakterystykę szlifowania powierzchni płasko-równoległych z kinematyką docierania obiegowego. Analizowano obróbkę materiałów konstrukcyjnych na docierarkach dwutarczowych. Porównano warunki i wyniki szlifowania z tradycyjnym docieraniem luźnym ścierniwem. Scharakteryzowano sposób wyrównywania powierzchni roboczych narzędzi oraz omówiono główne zalety szlifowania na docierarkach.

  • Tailoring Defects in B, N-Codoped Carbon Nanowalls for Direct Electrochemical Oxidation of Glyphosate and its Metabolites
    • Mattia Pierpaoli
    • Paweł Jakóbczyk
    • Mateusz Ficek
    • Bartłomiej Dec
    • Jacek Ryl
    • Bogdan Rutkowski
    • Aneta Lewkowicz
    • Robert Bogdanowicz
    2024 Pełny tekst ACS Applied Materials & Interfaces

    Tailoring the defects in graphene and its related carbon allotropes has great potential to exploit their enhanced electrochemical properties for energy applications, environmental remediation, and sensing. Vertical graphene, also known as carbon nanowalls (CNWs), exhibits a large surface area, enhanced charge transfer capability, and high defect density, making it suitable for a wide range of emerging applications. However, precise control and tuning of the defect size, position, and density remain challenging; moreover, due to their characteristic labyrinthine morphology, conventional characterization techniques and widely accepted quality indicators fail or need to be reformulated. This study primarily focuses on examining the impact of boron heterodoping and argon plasma treatment on CNW structures, uncovering complex interplays between specific defect-induced three-dimensional nanostructures and electrochemical performance. Moreover, the study introduces the use of defect-rich CNWs as a label-free electrode for directly oxidizing glyphosate (GLY), a common herbicide, and its metabolites (sarcosine and aminomethylphosphonic acid) for the first time. Crucially, we discovered that the presence of specific boron bonds (BC and BN), coupled with the absence of Lewis-base functional groups such as pyridinic-N, is essential for the oxidation of these analytes. Notably, the D+D* second-order combinational Raman modes at ≈2570 cm–1 emerged as a reliable indicator of the analytes’ affinity. Contrary to expectations, the electrochemically active surface area and the presence of oxygen-containing functional groups played a secondary role. Argon-plasma post-treatment was found to adversely affect both the morphology and surface chemistry of CNWs, leading to an increase in sp3-hybridized carbon, the introduction of oxygen, and alterations in the types of nitrogen functional groups. Simulations support that certain defects are functional for GLY rather than AMPA. Sarcosine oxidation is the least affected by defect type.

  • Tailoring Physicochemical Properties of V2O5 Nanostructures: Influence of Solvent Type in Sol-Gel Synthesis
    • Klaudia Prusik
    • Daniel Jaworski
    • Justyna Gumieniak
    • Agnieszka Kramek
    • Kamila Sadowska
    • Marta Prześniak-Welenc
    2024 Materials

    The influence of different solvents, including aqueous and nonaqueous types, on the physicochemical properties of V2O5 nanostructures was thoroughly investigated. Various characterization techniques, such as XRD, XPS, FTIR, Raman spectroscopy, UV-vis DRS, SEM, TEM, and BET, were employed to analyze the obtained materials. Additionally, the adsorption properties of the synthesized V2O5 nanostructures for methylene blue were examined, and kinetic parameters of adsorption were calculated. The results demonstrate that the morphology of the obtained crystals can be finely controlled by manipulating water concentration in the solution, showcasing its profound impact on both the structural characteristics and adsorption properties of the nanostructures. Furthermore, the structural changes of the resulting V2O5 material induced by solvents show strong impacts on its photocatalytic properties, making it a promising photocatalyst.

  • Tailoring the Transport Layer Interface for Relative Indoor and Outdoor Photovoltaic Performance
    • Chia-Feng Li
    • Shih-Han Cheng
    • Hou-Chin Cha
    • Ssu-Yung Chung
    • Damian Głowienka
    • Chih-Min Chuang
    • Yu-Ching Huang
    2024 ACS Applied Energy Materials

    The ability to achieve notable indoor power conversion efficiency (PCE) makes organic photovoltaics (OPV) a potential technology for indoor applications. Currently, ongoing research in indoor OPVs focuses on improving both their indoor PCE and their stability. However, little attention has been given to investigating the fabrication yield of indoor OPVs, a pivotal determinant of their potential commercial viability. In this study, we discovered that despite assessing the PCE of OPVs under indoor and solar illumination conditions using the same devices, the fabrication yields under these distinct light sources vary significantly. Employing diverse analytical measurements, we elucidated the underlying mechanisms contributing to this variance. Our findings suggest that disparities in fabrication yield resulted from the interfacial interactions between the hole transport layer (HTL) and the active layer. Particularly, the interfacial behavior between these layers plays a decisive role in achieving elevated fabrication yields in indoor OPVs. Furthermore, we demonstrate the function of a combination of two HTLs (TAPC/MoO3), which not only enhances the indoor PCE of OPVs but also substantially improves the fabrication yield of indoor OPVs. Our study offers insights and critical guidance for the advancement of indoor OPVs with high fabrication yields.

  • Tailor-Made Polysaccharides for Biomedical Applications
    • Mohsen Khodadadiyazdi
    • Farzad Seidi
    • Aleksander Hejna
    • Payam Zarrintaj
    • Navid Rabiee
    • Justyna Kucińska-Lipka
    • Mohammad Saeb
    • Sidi A. Bencherif
    2024 ACS Applied Bio Materials

    Polysaccharides (PSAs) are carbohydrate-based macromolecules widely used in the biomedical field, either in their pure form or in blends/nanocomposites with other materials. The relationship between structure, properties, and functions has inspired scientists to design multifunctional PSAs for various biomedical applications by incorporating unique molecular structures and targeted bulk properties. Multiple strategies, such as conjugation, grafting, cross-linking, and functionalization, have been explored to control their mechanical properties, electrical conductivity, hydrophilicity, degradability, rheological features, and stimuli-responsiveness. For instance, custom-made PSAs are known for their worldwide biomedical applications in tissue engineering, drug/gene delivery, and regenerative medicine. Furthermore, the remarkable advancements in supramolecular engineering and chemistry have paved the way for mission-oriented biomaterial synthesis and the fabrication of customized biomaterials. These materials can synergistically combine the benefits of biology and chemistry to tackle important biomedical questions. Herein, we categorize and summarize PSAs based on their synthesis methods, and explore the main strategies used to customize their chemical structures. We then highlight various properties of PSAs using practical examples. Lastly, we thoroughly describe the biomedical applications of tailor-made PSAs, along with their current existing challenges and potential future directions.

  • Targeting Candida albicans O-acetyl-L-homoserine sulfhydrylase (Met15p) in antifungal treatment
    • Aleksandra Kuplińska
    • Kamila Rząd
    • Joanna Stefaniak-Skorupa
    • Katarzyna Kozłowska-Tylingo
    • Marek Wojciechowski
    • Sławomir Milewski
    • Iwona Gabriel
    2024 Pełny tekst Scientific Reports

    Fungal infections are a serious threat to public health as they are becoming increasingly frequent. A major problem stems also from a rising fungal resistance to currently available antifungal therapies, therefore novel molecular targets are highly desirable. Exploration of enzymes participating in the biosynthesis pathways of essential amino acids such as L-methionine (L-Met) may provide new insights into pharmaceutical development. The MET15 gene from Candida albicans, encoding O- acetyl-L-homoserine sulfhydrylase (Met15p), an enzyme catalyzing the second step in that pathway, was cloned and expressed in two versions: as N and C-terminal oligo-His-tagged fusion proteins. The recombinant enzymes revealed appropriate activity, and catalyzed conversion of O-acetyl-L-homoserine and a sulfide ion to produce L-homocysteine. A new RP-HPLC-DAD method, using the enzymatic reaction product pre-column derivatization with 5,5’-dithio-bis-(2-nitrobenzoic acid) was developed and used by us to determine Met15p activity. Newly synthesized compounds as well as two commercially available exhibited a Met15p inhibitory effect which was related to antifungal activity. Fungal cells’ sensitivity to inhibitors depending on the presence or absence of L-Met in the medium clearly indicated Met15p targeting. Moreover, the synergistic effect of the first methionine biosynthetic enzyme affecting inhibitor and Met15p inhibitors indicate that methionine biosynthesis pathway enzymes are promising molecular targets.

  • Targeting shelterin proteins for cancer therapy.
    • Wioletta Brankiewicz-Kopcinska
    • Anoop Kallingal
    • Radosław Krzemieniecki
    • Maciej Bagiński
    2024 DRUG DISCOVERY TODAY

    As a global health challenge, cancer prompts continuous exploration for innovative therapies that are also based on new targets. One promising avenue is targeting the shelterin protein complex, a safeguard for telomeres crucial in preventing DNA damage. The role of shelterin in modulating ataxia- telangiectasia mutated (ATM) and ataxia-telangiectasia and Rad3-related (ATR) kinases, key players in the DNA damage response (DDR), establishes its significance in cancer cells. Disrupting these defence mechanisms of shelterins, especially in cancer cells, renders telomeres vulnerable, potentially leading to genomic instability and hindering cancer cell survival. In this review, we outline recent approaches exploring shelterins as potential anticancer targets, highlighting the prospect of developing selective molecules to exploit telomere vulnerabilities toward new innovative cancer treatments.

  • Targeting yeast topoisomerase II by imidazo and triazoloacridinone derivatives resulting in their antifungal activity
    • Kamila Rząd
    • Iwona Gabriel
    • Ewa Paluszkiewicz
    • Aleksandra Kuplińska
    • Mateusz Olszewski
    • Agnieszka Chylewska
    • Aleksandra M. Dąbrowska
    • Katarzyna Kozłowska-Tylingo
    2024 Pełny tekst Scientific Reports

    Fungal pathogens are considered as serious factors for deadly diseases and are a case of medical concern. Invasive fungal infections also complicate the clinical course of COVID-19, leading to a significant increase in mortality. Furthermore, fungal strains' multidrug resistance has increased the demand for antifungals with a different mechanism of action. The present study aimed to identify antifungal compounds targeting yeast topoisomerase II (yTOPOII) derived from well-known human topoisomerase II (hTOPOII) poisons C-1305 and C-1311. Two sets of derivatives: triazoloacridinones (IKE1-8) and imidazoacridinones (IKE9-14) were synthetized and evaluated with a specific emphasis on the molecular mechanism of action. Our results indicated that their effectiveness as enzyme inhibitors was not solely due to intercalation ability but also as a result of influence on catalytic activity by the formation of covalent complexes between plasmid DNA and yTOPOII. Lysine conjunction increased the strength of the compound's interaction with DNA and improved penetration into the fungal cells. Triazoloacridinone derivatives in contrast to starting compound C-1305 exhibited moderate antifungal activity and at least twice lower cytotoxicity. Importantly, compounds (IKE5-8) were not substrates for multidrug ABC transporters whereas a derivative conjugated with lysine (IKE7), showed the ability to overcome C. glabrata fluconazole-resistance (MIC 32–64 µg mL−1).

  • Task-recency bias strikes back: Adapting covariances in Exemplar-Free Class Incremental Learning
    • Grzegorz Rypeść
    • Sebastian Cygert
    • Tomasz Trzciński
    • Bartłomiej Twardowski
    2024 Pełny tekst

    Exemplar-Free Class Incremental Learning (EFCIL) tackles the problem of training a model on a sequence of tasks without access to past data. Existing state-of-the-art methods represent classes as Gaussian distributions in the feature extractor's latent space, enabling Bayes classification or training the classifier by replaying pseudo features. However, we identify two critical issues that compromise their efficacy when the feature extractor is updated on incremental tasks. First, they do not consider that classes' covariance matrices change and must be adapted after each task. Second, they are susceptible to a task-recency bias caused by dimensionality collapse occurring during training. In this work, we propose AdaGauss - a novel method that adapts covariance matrices from task to task and mitigates the task-recency bias owing to the additional anti-collapse loss function. AdaGauss yields state-of-the-art results on popular EFCIL benchmarks and datasets when training from scratch or starting from a pre-trained backbone.

  • Teaching High–performance Computing Systems – A Case Study with Parallel Programming APIs: MPI, OpenMP and CUDA
    • Paweł Czarnul
    • Mariusz Matuszek
    • Adam Krzywaniak
    2024

    High performance computing (HPC) education has become essential in recent years, especially that parallel computing on high performance computing systems enables modern machine learning models to grow in scale. This significant increase in the computational power of modern supercomputers relies on a large number of cores in modern CPUs and GPUs. As a consequence, parallel program development based on parallel thinking has become a necessity to fully utilize modern HPC systems' computational power. Therefore, teaching HPC has become essential in developing skills required by the industry. In this paper we share our experience of conducting a dedicated HPC course, provide a brief description of the course content, and propose a way to conduct HPC laboratory classes, in which a single task is implemented using several APIs, i.e., MPI, OpenMP, CUDA, hybrid MPI+Pthreads, and MPI+OpenMP. Based on the actual task of verifying Goldbach's conjecture for a given range of numbers, we present and analyze the performance evaluation of students' solutions and code speed-ups for MPI and OpenMP. Additionally, we evaluate students' subjective assessment of ease of use of particular APIs along with the lengths of codes, and students' performance over recent years.

  • Teaching of Robot Arm Programming - Tasks with Increasing Difficulty
    • Marek Chodnicki
    • Alina Guzik
    • Marek Galewski
    • Wiktor Sieklicki
    • Michał Mazur
    2024

    The article describes education techniques using robotics. For example, educational exercises on programming the Nachi MZ04 robotic arm are presented. The exercises use a wooden railroad toy model and elements printed in additive manufacturing technology. The exercises have increasing difficulty and can be used to educate young people in high school and specialized higher engineering studies (both bachelor's and master's).

  • Techno-economic analysis of a hybrid energy system for electrification using an off-grid solar/biogas/battery system employing HOMER: A case study in Vietnam
    • Van Bac Nguyen
    • Prabhakar Sharma
    • Bhaskor Jyoti Bora
    • Thi Minh Tu Bui
    • Cristina Efremov
    • Minh Ho Tran
    • Jerzy Kowalski
    • Sameh M. Osman
    • Dao Nam Cao
    • Van Huong Dong
    2024 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION

    The electrification of off-grid /island villages is a critical step towards improving the techno-economic circumstances of rural regions and the overall general growth of the country. However, consistent supply from a single source is not possible in these areas. Thus, a hybrid renewable energy system performs better in these conditions. The research challenge now is to identify the optimal combinations of HRES from the available resources in a specific village site that can supply the power demand sustainably and to determine whether this is a cost-effective option. The present work is an endeavour to develop a sustainable and dynamic energy demandsupply model using HOMER Pro energy software in a specified off-grid rural site in Vietnam. The research presents four unique configurations of a combined energy system for Vietnam’s island settlements, incorporating biomass-based biogas facilities, photovoltaic panels, lithium-ion batteries, and converters. Homer Pro was used for optimization and design, focusing on key performance measures such as cost of energy, net present cost, initial cost, operating cost, renewable fraction, and carbon emissions. The best HES system layout includes a 100- kW biomass-based generator, 2.62 kW photovoltaic installation, 10 lithium-ion batteries, and a 6.31 kW converter, producing 100 % renewable energy. The system’s low cost of energy ($0.48), and net present cost ($25,730.89) make it an economically viable alternative, while its low CO2 emissions demonstrate its commitment to reducing greenhouse gas emissions.

  • Technological solutions to landfill management: Towards recovery of biomethane and carbon neutrality
    • Hussein Al-Hazmi
    • Gamal K. Hassan
    • Tonni Agustiono Kurniawan
    • Bogna Śniatała
    • Tomy M. Joseph
    • Joanna Majtacz
    • Grzegorz Piechota
    • Xiang Li
    • Fatma A. El-Gohary
    • Mohammad Saeb
    • Jacek Mąkinia
    2024 JOURNAL OF ENVIRONMENTAL MANAGEMENT

    Inadequate landfill management poses risks to the environment and human health, necessitating action. Poorly designed and operated landfills release harmful gases, contaminate water, and deplete resources. Aligning landfill management with the Sustainable Development Goals (SDGs) reveals its crucial role in achieving various targets. Urgent transformation of landfill practices is necessary to address challenges like climate change, carbon neutrality, food security, and resource recovery. The scientific community recognizes landfill management's impact on climate change, evidenced by in over 191 published articles (1998–2023). This article presents emerging solutions for sustainable landfill management, including physico-chemical, oxidation, and biological treatments. Each technology is evaluated for practical applications. The article emphasizes landfill management's global significance in pursuing carbon neutrality, prioritizing resource recovery over end-of-pipe treatments. It is important to note that minimizing water, chemical, and energy inputs in nutrient recovery is crucial for achieving carbon neutrality by 2050. Water reuse, energy recovery, and material selection during manufacturing are vital. The potential of water technologies for recovering macro-nutrients from landfill leachate is explored, considering feasibility factors. Integrated waste management approaches, such as recycling and composting, reduce waste and minimize environmental impact. It is conclusively evident that the water technologies not only facilitate the purification of leachate but also enable the recovery of valuable substances such as ammonium, heavy metals, nutrients, and salts. This recovery process holds economic benefits, while the conversion of CH4 and hydrogen into bioenergy and power generation through microbial fuel cells further enhances its potential. Future research should focus on sustainable and cost-effective treatment technologies for landfill leachate. Improving landfill management can mitigate the adverse environmental and health effects of inadequate waste disposal.

  • Temperature Measurements at Tyre Tread Rubber on Sandpaper Oscillatory Sliding Contacts Using Acicular Grindable Thermocouples
    • Oleksii Nosko
    • Yurii Tsybrii
    • Pablo Guillermo Torrelio Arias
    • Adolfo Senatore
    2024 Pełny tekst TRIBOLOGY LETTERS

    The tribological performance of tyre–road contacts depends crucially on the contact temperature. This study investigates the reliability and accuracy of acicular grindable thermocouples possessing an original needle-shaped wearable part as applied to measuring temperature at the oscillatory sliding contact between a rubber tyre tread sample and a sandpaper. A linear oscillatory tribometer is used to imitate the sliding phase of tyre–road contact under mild friction conditions. It is shown that the acicular grindable thermocouple measurements are generally test–retest repeatable. Moreover, the thermocouple signal becomes more stable with increasing contact pressure. Compared to the conventional thermocouple technique, the acicular grindable thermocouple overestimates temperature at the rubber friction surface by about 23% due to involvements of its wearable part in friction with the sandpaper. The findings suggest an expansion of the acicular grindable thermocouple technique to full-scale experiments with tyres on the road.

  • Teoria grafów wczoraj i dziś
    • Marek Kubale
    2024

    W pracy naszkicowano kamienie milowe teorii grafów poczynając od pierwszego artykułu Eulera na temat mostów w Królewcu z połowy 18. wieku. Następnie opisano słynny problem 4 barw i jego wariacje. Pracę kończy charakterystyka najnowszych wyzwań teorii grafów.