2024 - Repozytorium publikacji - Politechnika Gdańska

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Transport Mechanism of Paracetamol (Acetaminophen) in Polyurethane Nanocomposite Hydrogel Patches—Cloisite® 30B Influence on the Drug Release and Swelling Processes
- Justyna Strankowska
- Małgorzata Grzywińska
- Ewelina Łęgowska
- Marek Józefowicz
- Michał Strankowski
2024 Pełny tekst Materials
This article describes the swelling and release mechanisms of paracetamol in polyurethane nanocomposite hydrogels containing Cloisite® 30B (organically modified montmorillonite). The transport mechanism, swelling and release processes of the active substance in nanocomposite matrix were studied using gravimetric and UV-Vis spectroscopic methods. Swelling and release processes depend on the amount of clay nanoparticles in these systems and the degree of crosslinking of PU/PEG/Cloisite® 30B hydrogel nanocomposites.
TR-Based Antenna Design with Forward FD: The Effects of Step Size on the Optimization Performance
- Adrian Bekasiewicz
- Sławomir Kozieł
- Tom Dhaene
- Marcin Narloch
2024
Numerical methods are important tools for design of modern antennas. Trust-region (TR) methods coupled with data-efficient surrogates based on finite differentiation (FD) represent a popular class of antenna design algorithms. However, TR performance is subject to FD setup, which is normally determined a priori based on rules-of-thumb. In this work, the effect of FD perturbations on the performance of TR-based design is evaluated on a case study basis concerning a total of 80 optimizations of a planar antenna structure. The obtained results demonstrate that, for the considered radiator, the performance of the final designs obtained using different FD setups may vary by as much as 18 dB (and by over 4 dB on average). At the same time, the a priori perturbations in a range between 1.5% and 3% (w.r.t. the initial design) seem to be suitable for maintaining (relatively) consistent and high-quality results.
Treatment of Odontogenic Maxillary Sinusitis with the Use of Growth Factors in Advanced Platelet-Rich Fibrin for Immediate Closure of Oro-Antral Communication: A Case Report
- Paulina Adamska
- Dorota Pylińska-Dąbrowska
- Marcin Stasiak
- Magdalena Kaczoruk-Wieremczuk
- Ewa Kozłowska
- Adam Zedler
- Michal Studniarek
2024 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Chronic odontogenic maxillary sinusitis (COMS), a prolonged inflammation of the maxillary sinus lasting over 12 weeks, is often a result of periapical lesions, marginal periodontitis, and complications like oro-antral communication (OAC) and fistula (OAF). OAC, commonly emerging post-teeth extraction in the lateral maxilla, lacks documented treatments using advanced platelet-rich fibrin (A-PRF). This study evaluates A-PRF’s efficacy in treating COMS and immediately sealing extensive OAC. A case of a 28-year-old male with COMS linked to a periapical lesion and supernumerary molars is presented. Treatment involved extracting specific teeth while preserving adjacent ones and using A-PRF for immediate OAC closure. A-PRF, enriched with growth factors, was pivotal in healing, showcasing enhanced tissue regeneration, pain reduction, and faster recovery. The findings suggest A-PRF as an effective adjunct in treating extensive OAC and COMS, proposing its inclusion in standard treatment protocols. This study underscores A-PRF’s potential in improving outcomes for patients with COMS and related complications.
Treatment of Oroantral Communication and Fistulas with the Use of Blood-Derived Platelet-Rich Preparations Rich in Growth Factors: A Systematic Review
- Paulina Adamska
- Magdalena Kaczoruk-Wieremczuk
- Dorota Pylińska-Dąbrowska
- Marcin Stasiak
- Michał Bartmański
- Adam Zedler
- Michal Studniarek
2024 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
The formation of an oroantral communication (OAC) or fistula (OAF) is a rare complication resulting from the presence of processes in the lateral parts of the maxilla or for iatrogenic reasons. The most common causes of OAC or OAF are tooth extraction with periapical lesions. The aims of this systematic review were to assess the use of platelet-derived preparations rich in growth factors in the treatment of OAC or OAF, to determine the success of treating the communication or fistula, as well as impact on postoperative complications and the course of healing. The study was performed following PRISMA guidelines (PROSPERO: CRD42024570758). The inclusion criteria were as follows: at least ten patients, the presence of oroantral communication or oroantral fistula, treatment with platelet-derived preparations rich in growth factors, and information regarding the response to treatment. In order to find relevant studies, international databases, including PubMed, Google Scholar, Web of Science Core Collection, MDPI, Wiley, and Cochrane Library were searched. The last search was performed on 31 August 2024. Seven articles were included in the systematic review. In total, platelet-derived preparations rich in growth factors were used in 164 patients. Only studies in which OAC was treated and with platelet-rich fibrin (PRF) met the inclusion criteria. Only PRF was used as the sole treatment method in three studies. When OAC is greater than 5 mm, platelet-derived preparations rich in growth factors should be considered adjuncts to treatment, not the sole treatment method. The success rate of OAC treatment was 90–100%. The use of blood products to close OAC may be an effective therapeutic alternative. Proper patient qualification and the use of an appropriate protocol are crucial. There is a need for future well-designed case-control or cohort studies as well as randomized controlled trials to provide the required level of evidence.
TRF1 and TRF2: pioneering targets in telomere-based cancer therapy
- Anoop Kallingal
- Radosław Krzemieniecki
- Natalia Maciejewska
- Wioletta Brankiewicz-Kopcinska
- Maciej Bagiński
2024 JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY
This article presents an in-depth exploration of the roles of Telomere Repeat-binding Factors 1 and 2 (TRF1 and TRF2), and the shelterin complex, in the context of cancer biology. It emphasizes their emerging significance as potential biomarkers and targets for therapeutic intervention. Central to the shelterin complex, TRF1 and TRF2 are crucial in maintaining telomere integrity and genomic stability, their dysregulation often being a hallmark of cancerous cells. The article delves into the diagnostic and prognostic capabilities of TRF1 and TRF2 across various cancer types, highlighting their sensitivity and specificity. Furthermore, it reviews current strides in drug discovery targeting the shelterin complex, detailing specific compounds and their modes of action. The review candidly addresses the challenges in developing therapies aimed at the shelterin complex, including drug resistance, off-target effects, and issues in drug delivery. By synthesizing recent research findings, the article sheds light on the intricate relationship between telomere biology and cancer development. It underscores the urgency for continued research to navigate the existing challenges and fully leverage the therapeutic potential of TRF1, TRF2, and the shelterin complex in the realm of cancer treatment.
Triaxial compression and shear strength characteristics of twostage concrete: an experimental study
- Farzam Omidi Moaf
- Ali M. Rajabi
- Hakmi S. Abdelgader
- Marzena Kurpińska
- G. Murali
- Mikołaj Miśkiewicz
2024 Scientific Reports
The research necessity stems from the need to understand and evaluate the performance of Two- Stage Concrete (TSC) under triaxial compression conditions, as prior studies have predominantly focused on uniaxial and biaxial testing of conventional concrete (CC). This study represents the first comprehensive investigation into the triaxial compressive strength and related mechanical properties of TSC, addressing a critical gap in the existing body of literature. Three different mixtures were prepared, including one CC and two TSC variants with varying cement content. The results and behavior of these mixtures were compared to assess their performance. Findings reveal that TSC, particularly those types with finer aggregates, demonstrates superior shear strength, achieving up to 52.4 MPa under dry conditions, in contrast to the 48.38 MPa observed in CC. Furthermore, TSC exhibits remarkable stress tolerance, withstanding up to 82.04 MPa, significantly outperforming CC, which withstands only 69.61 MPa under similar conditions. This behavior can be attributed to the higher coarse aggregate content, the increased interaction and contact points between coarse aggregates, the improved bonding between them, and the inherent properties of the grout. TSC also maintains a higher modulus of elasticity and internal friction angles, indicating superior deformation behavior and shear resistance. Additionally, TSC shows greater resilience to moisture, suggesting its potential suitability for use in variable moisture environments. These properties highlight the strength of TSC for high-load applications and its suitability for infrastructure prone to environmental fluctuations.
Triple correlation states between in-situ tested soil parameters
- Eligiusz Mieloszyk
- Mariusz Wyroślak
2024 Archives of Civil Engineering
When testing soil parameters, the measured parameter values are only approximations of the true values. The measurand is determined based on metrological uncertainties or using statistical models for analysing data. Some parameters of the soil state present strong correlations, but others do not always provide simple correspondences. Multiple correlations between geotechnical parameters can provide a new perspective regarding the mutual relations between these parameters and may improve the ﬁt of diﬀerent soil parameters in geotechnical design procedures. Statistical modelling based on observed data generally involves a comparison between theoretical expectancies and practical surveys. Multidimensional regression models are useful for revealing the inﬂuences of several independent variables on one dependent variable. Statistical parameters and a quantitative approach can be used to deﬁne the relationships between several factors. Presented results claim that triple depended correlations may bring some corrects in relationships of soil parameters as against to double depended correlations. The diﬀerences in coeﬃcients of determination are signiﬁcant. Three variables involved stronger correlations.
Triplet–Triplet Annihilation Upconverting Liposomes: Mechanistic Insights into the Role of Membranes in Two-Dimensional TTA-UC
- Amrutha Prabhakaran
- Keshav Kumar Jha
- Rengel Cane Sia
- Ruben Arturo Arellano-Reyes
- Nirod Kumar Sarangi
- Mateusz Kogut
- Julien Guthmuller
- Jacek Czub
- Benjamin Dietzek-Ivanšić
- Tia E. Keyes
2024 Pełny tekst ACS Applied Materials & Interfaces
Triplet−triplet annihilation upconversion (TTA-UC) implemented in nanoparticle assemblies is of emerging interest in biomedical applications, including in drug delivery and imaging. As it is a bimolecular process, ensuring sufficient mobility of the sensitizer and annihilator to facilitate effective collision in the nanoparticle is key. Liposomes can provide the benefits of two-dimensional confinement and condensed concentration of the sensitizer and annihilator along with superior fluidity compared to other nanoparticle assemblies. They are also biocompatible and widely applied across drug delivery modalities. However, there are relatively few liposomal TTA-UC systems reported to date, so systematic studies of the influence of the liposomal environment onTTA-UC are currently lacking. Here, we report the first example of a BODIPY-based sensitizer TTA-UC system within liposomes and use this system to study TTA-UC generation and compare the relative intensity of the anti-Stokes signal for this system as a function of liposome composition and membrane fluidity. We report for the first time on time-resolved spectroscopic studies of TTA-UC in membranes. Nanosecond transient absorption data reveal the BODIPY-perylene dyad sensitizer has a long triplet lifetime in liposome with contributions from three triplet excited states, whose lifetimes are reduced upon coinclusion of the annihilator due to triplet−triplet energy transfer, to a greater extent than in solution.This indicates triplet energy transfer between the sensitizer and the annihilator is enhanced in the membrane system. Molecular dynamics simulations of the sensitizer and annihilator TTA collision complex in the membrane confirm the co-orientation of the pair within the membrane structure and that the persistence time of the bound complex exceeds the TTA kinetics. The relative intensity of the TTA-UC output across nine liposomal systems of different lipid compositions was explored to examine the influence of membrane viscosity on upconversion (UC). UC showed the highest relative intensity for the most fluidic membranes and the weakest intensity for highly viscous membranes. Overall, our study reveals that the co-orientation of the UC pair within the membrane is crucial for effective TTA-UC and that the intensity of the TTA-UC output can be tuned in liposomes by modifying their phase and fluidity. These new insights will aid in the design of liposomal TTA-UC systems for biomedicalapplications
Trwałość łączeniowa i udarowa źródeł oświetlenia LED w środowiskach z występującymi zaburzeniami harmonicznymi
- Stanisław Galla
- Mirosław Włas
2024 Pełny tekst Przegląd Elektrotechniczny
W artykule przedstawiono wyniki badań trwałości łączeniowej i udarowej źródeł światła LED w przypadku występowania zaburzeń harmonicznymi w napięciu zasilania. Przeprowadzone badania wskazują na znaczący wpływ odkształceń napięcia zasilania zarówno na trwałość łączeniową jak i na badania wytrzymałości udarowej przeprowadzane wg zaleceń zawartych w EN 61000-4-5.
Tunable emission and energy transfer of B2O3–Bi2O3–AlF3 glass system doped with Eu3+/Dy3+
- Karolina Milewska
- Michał Edmund Maciejewski
- Michal Žitňan
- José Joaquín Velázquez
- Dušan Galusek
- Wojciech Sadowski
- Barbara Kościelska
2024 JOURNAL OF LUMINESCENCE
The structure and luminescent properties of the B2O3–Bi2O–AlF3 glass system doped with Eu3+/Dy3+ ions in different molar ratios were studied. A series of glasses were synthesized by the conventional melt quenching technique. Glass transition and crystallization temperatures were examined by Differential Thermal Analysis (DTA) measurements. The amorphous character of the prepared samples was confirmed by the X-ray diffraction (XRD) method. Raman and FTIR spectra were collected and deconvoluted to investigate the glass microstructure. Luminescence spectra revealed that the added rare-earth ions can be excited by a single wavelength. The emitted color can be tuned by changing the ratios of the Eu3+/Dy3+ ions and the excitation wavelength. Furthermore, the influence of the addition of AlF3 on the luminescence and decay times was investigated. In the glasses with 10 mol% AlF3 an enhancement of the emission and excitation spectra was detected. The energy transfer analysis confirms the energy transfer between Eu3+ and Dy3+ ions in the glass matrix. Additionally, the results of this study indicate that the B2O3–Bi2O–AlF3 glasses doped with Eu3+ and Dy3+ can be used as a color tunable phosphor.
Tuning of food wastes bioavailability as feedstock for bio-conversion processes by acoustic cavitation and SPC, SPS, or H2O2 as external oxidants
- Zahra Askarniya
- Lingshuai Kong
- Chongqing Wang
- Shirish H. Sonawane
- Jacek Mąkinia
- Grzegorz Boczkaj
2024 Pełny tekst CHEMICAL ENGINEERING AND PROCESSING
The growing amount of food wastes makes them a suitable source for the generation of bioproducts through anaerobic digestion. Appropriate hydrolysis of the feedstock can enhance the efficiency of production of desired products. In this work, acoustic cavitation (AC) was employed as a pretreatment method to enhance hydrolysis stage by the modification of model (potato-based) food waste for increase in soluble chemical oxygen demand (CODs) and dissolved carbohydrate. For the first time high and low frequency AC was compared for this purpose. The application of sole AC at a frequency of 20 kHz for feedstock loading of 3 % has led to 125 % and 124 % increase in CODs and dissolved carbohydrates, respectively. The combination of AC with external oxidants hydrogen peroxide (H2O2), sodium persulfate (SPS), and sodium percarbonate (SPC) was also studied. This part of the studies revealed that SPS has superior properties for increasing CODs by 258 % and dissolved carbohydrates by 240 %. On the other hand, addition of sodium hydroxide (NaOH) as alternative reagent, leads to a 173 % increase in CODs and 155 % increase in dissolved carbohydrates. Making both ways of processing highly effective to increase the bioavailability of food wastes for further biologic processing.
Tuning the work function of graphite nanoparticles via edge termination
- Michael P. Mercer
- Arihant Bhandari
- Chao Peng
- Jacek Dziedzic
- Chris-Kriton Skylaris
- Denis Kramer
2024 Pełny tekst PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Graphite nanoparticles are important in energy materials applications such as lithium-ion batteries (LIBs), supercapacitors and as catalyst supports. Tuning the work function of the nanoparticles allows local control of lithiation behaviour in LIBs, and the potential of zero charge of electrocatalysts and supercapacitors. Using large scale density functional theory (DFT) calculations, we find that the surface termination of multilayer graphene nanoparticles can substantially modify the work function. Calculations in vacuum and in electrolyte show that manipulating the edge termination substantially modifies the potential not only around the edge, but also on the basal plane. Termination with hydrogen or oxygen completely reverses the potential distribution surrounding the basal plane and edges. The trends can be explained based on the work function differences of the edges dependent on termination, and that of the basal plane. Electronic equilibration between different surfaces at the nanoscale allows manipulation of the work function. We demonstrate a link between the area of the graphite basal plane via changing the nanoparticle size, and the work function. We expect that these insights can be utilised for local control of electrochemical functions of graphite nanoparticles prepared under oxidising or reducing conditions.
Tutoring rówieśniczy jako skuteczna metoda wspierania procesu uczenia się
- Agnieszka Bartłomiejczyk
- Brygida Mielewska
2024 Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
W artykule przedstawione zostały zarówno teoretyczne podstawy, jak i praktyczne zastosowania efektywnej formy wsparcia dydaktycznego jaką jest tutoring rówieśniczy. Analizie poddane zostały zajęcia realizowane w ramach tutoringu rówieśniczego na Wydziale Fizyki Technicznej i Matematyki Stosowanej Politechniki Gdańskiej. Analiza obejmuje ocenę efektywności tych zajęć, zaangażowanie studentów oraz ich satysfakcję z procesu nauki. Omówione zostały również wnioski i rekomendacje dotyczące dalszego rozwijania programów tutoringowych, które mogą przyczynić się do poprawy jakości kształcenia na poziomie akademickim.
Typology, current state and non-destructive testing of timber roof trusses of historic churches in the West Vistula Delta, Poland
- Tomasz Zybała
- Monika Zielińska
- Magdalena Rucka
- Jarosław Przewłócki
- Karol Grębowski
2024 Pełny tekst Heritage Science
This paper presents the current state of conservation of historic roof churches located in the Żuławy of Gdańsk (Poland). It also describes the architecture of these temples, the region itself and old carpentry techniques for constructing roof trusses. Interdisciplinary tests were carried out in six churches. The geometry of the load bearing structures, the moisture content and the carpentry technique were specified. The field survey also included visual inspections and non-destructive testing of timber structural elements of the roof constructions. The ground penetrating radar and ultrasonic testing methods were used to assess the structure and extent of the damage to the timber elements. The interdisciplinary research presented in this article is important in the planning of historic buildings conservation works and it might be applied to other timber structures.
UAV measurements and AI-driven algorithms fusion for real estate good governance principles support
- Paweł Tysiąc
- Artur Janowski
- Marek Walacik
2024 International Journal of Applied Earth Observation and Geoinformation
The paper introduces an original method for effective spatial data processing, particularly important for land administration and real estate governance. This approach integrates Unmanned Aerial Vehicle (UAV) data acquisition and processing with Artificial Intelligence (AI) and Geometric Transformation algorithms. The results reveal that: (1) while the separate applications of YOLO and Hough Transform algorithms achieve building detection rates up to 77% and 83%, respectively, (2) a novel methodology is proposed to combine spatial data and assess their quality of the detected buildings by comparing the generated building polygons with existing cadastral maps. The evaluation uses a polygon-based comparison approach, which computes metrics such as Precision, Recall, F1-Score, and Accuracy based on the spatial relationships between predicted and reference building contours, (3) the weighted model showed about 7 % improvement in accuracy compared to cadastral data. This innovative approach substantially improves spatial data processing, aiding in implementing principles for real estate good governance and offering a valuable asset for various land administration applications.
UAV-Based Hyperspectral Ultraviolet-Visible Interpolated Reflectance Images for Remote Sensing of Leaf Area Index
- Tomasz Berezowski
- Marcin Kulawiak
- Marek Kulawiak
2024 IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Despite its relation to a number of environmental parameters, ultraviolet (UV) reflectance is rarely used in remote sensing. In this study, we investigate the applicability of UV-vis reflectance for vegetation monitoring with unmanned aerial vehicles (UAV). We measure point reflectance over the study area using a UAV-borne spectrometer, project the points onto the Earth's surface, and interpolate them to obtain continuous reflectance images. We use the leaf area index (LAI) to demonstrate the applicability of UV reflectance for vegetation monitoring. Our results show that the UAV reflectance images match the Sentinel-2 reflectance. Our validation shows that the inclusion of UV reflectance to the visible reflectance in LAI models leads to the r2 increase of up to 29.2% and RMSE decrease of up to 18.9% in comparison to the LAI models using visible reflectance only. We have shown that measurement of UV reflectance is feasible in the 320–400 nm range using UAV remote sensing and that hyperspectral UV-vis reflectance imaging is useful for vegetation monitoring. Moreover, the obtained results lead us to believe that improvement of our measurement system, or conducting the experiments in a different location should make it possible to measure the reflectance at a wavelength of 290 nm. Finally, we discuss other potential applications of UV in remote sensing.
UE ETS: an in-depth descriptive analysis.
- Helena Anacka
- Claudia Nardone
2024
The European Emission Trading System (EU ETS) plays a pivotal role in the EU’s strategy to address climate change, serving as a fundamental instrument for cost-effective reduction of greenhouse gas emissions. Notably, it inaugurated the word’s first major carbon market and it continues to the largest one. Chapter 1 provides an in-depth examination of the EU ETS, spanning from its inception in 2005 to 2020. After providing a descriptive analysis of emission from stationary installation by year, country, and sector, market dynamics is analyzed. This analysis encompasses transaction frequency and volumes traded annually, as well as a breakdown by type of account and month. The study places special emphasis on Italian firms, comparing trading and non-trading entities, firms engaged solely in buying or purchasing, and those involved in both buying and purchasing activities. Additionally, the analysis distinguishes between inter-firm and intra-firm trades within the market.
Ulgi podatkowe w sektorze MŚP - wyniki badań
- Piotr Kasprzak
2024
Niniejsza książka powstała na podstawie rozprawy doktorskiej autora, której podstawowe cele obejmowały zbadanie i określenie, czy i w jakim stopniu preferencje podatkowe w postaci ulg i zwolnień są wykorzystywane przez przedsiębiorców należących do sektora MŚP. Celem poznawczym niniejszej pracy jest uporządkowanie wiedzy na temat stymulacyjnej funkcji podatków realizowanej poprzez system ulg i zwolnień. Badanie składało się z czterech etapów – badania pilotażowego w postaci sondażu ankietowego i wywiadów uzupełniających, zasadniczego badania ankietowego oraz drugiej tury wywiadów. Metoda sondażu diagnostycznego została wykorzystana przy zbieraniu danych pierwotnych wśród przedsiębiorstw sektora MŚP. Instrumentem pomiaru był opracowany przez autora kwestionariusz ankiety. Celem było przebadanie przedsiębiorstw spełniających definicję UE w zakresie mikro-, małych i średnich podmiotów, posiadających siedzibę na terytorium RP, podatników podatku dochodowego (CIT lub PIT), z różnych branż i sektorów Analiza wyników przeprowadzonych badań pozwoliła dokonać oceny wykorzystania ulg i zwolnień przez mikro-, małe i średnie przedsiębiorstwa. Wyniki badań pokazują, że system obowiązujących w Polsce preferencji podatkowych nie jest idealny. Ponadto, ze względu na wielokierunkowy zakres oddziaływania instrumentów podatkowych, ocena poszczególnych wdrożonych do systemu podatkowego rozwiązań jest zagadnieniem wielce skomplikowanym, a jednoznaczna ocena skuteczności oddziaływania – niejednokrotnie niemożliwa.
Ultra-Compact Self-Quadruplexing Microfluidically Frequency Reconfigurable Slot Antenna Using Half-Mode SIW
- Rusan Kumar Barik
- Sławomir Kozieł
2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
In this brief, the design of an ultra-compact self-quadruplexing frequency reconfigurable antenna (SQFRA) utilizing a half-mode substrate-integrated waveguide (HMSIW) and microfluidic channels is discussed. Four HMSIW cavities fed by four microstrip lines and slots are used to construct a highly compact antenna. The microstrip feedings to the HMSIW cavities are applied in such a way that the proposed antenna exhibits self-quadruplexing properties with good isolation. The working principle is explained by employing surface current densities, and an equivalent circuit model. In order to achieve frequency tunability, two or three empty sockets associated with each HMSIW cavity are drilled from the bottom plane and filled with dielectric fluids. The effect of height and locations of fluidic channels are discussed in detail. To validate the proposed tunability, a prototype of SQFTA is fabricated and demonstrated. The fabricated antenna provides frequency ranges of 16.46%, 17.84%, 11.99%, and 14.94% at the first, second, third, and fourth frequency bands, respectively. The SQFTA exhibits a small footprint of 0.084λg2, which makes it the most compact self-quadruplexing tunable antenna in the open literature. Furthermore, the fabricated antenna features high isolation greater than 24.7dB, and realized gain greater than 3.55 dBi at all the operating frequencies.
Ultrafast high-temperature sintering (UHS) of cerium oxide-based compound
- Ahsanul Kabir
- Bartłomiej Lemieszek
- Jakub Karczewski
- Emanuele De Bona
- Maxim Varenik
- Sebastian Molin
- Mattia Biesuz
2024 Pełny tekst Open Ceramics
Ultrafast high-temperature sintering (UHS) is an innovative sintering technique that can densify ceramics in a few seconds, dramatically reducing the carbon footprint and firing costs. In this work, the feasibility of applying UHS in Gd-doped ceria (GDC) and GDC-Er-stabilized bismuth oxide (ESB) composite powders was investigated. At high UHS currents (22-24 A), a fully dense GDC sample with a large grain size was obtained. Nonetheless, most of the GDC pellets exhibited micro/macro cracks, which were reduced by lowering the sample thickness. Moreover, the GDC-ESB composite sample exhibits no cracks or fragmentation at all, thanks to ESB as a sintering aid. This type of sample was further characterized from an electrochemical and electromechanical point of view. The GDC-ESB material displays an ionic conductivity value of ~1.5 x 10−2 S/cm at 600 °C and frequency-stable (0.1-350 Hz) room temperature electrostriction strain coefficient of ~10−18 (m/V)2.