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EN
The article presents a new type of APS (openwork masonry unit) and WAPS (filled openwork masonry unit) concrete masonry units with a frame made of concrete modified with recycled materials. The technical data of the developed masonry unit and the composition of concrete modified with a mixture of SBR (styrene butadiene rubber) and PET (polyethylene terephthalate) recycling additives, as well as the composition of the composite damping mixture based on these two materials, are given. In order to demonstrate the effectiveness of the developed solution in reducing mechanical vibrations, the influence of the impact of different mechanical wave frequencies on the developed APS and WAPS concrete masonry units was assessed. The test results were presented graphically and showed that filling the holes of a new type of concrete masonry unit with a recycled composite mixture improves its effectiveness in limiting the propagation of mechanical waves in the analyzed range from 8 to 5000 Hz, simultaneously allowing the effective management of recycled materials.
PL
W artykule przedstawiono nowego typu betonowe murowe elementy ścienne APS (ażurowy pustak ścienny) i WAPS (wypełniony ażurowy pustak ścienny) o szkielecie wykonanym z betonu modyfikowanego materiałami recyklingowymi. Podano dane techniczne opracowanego elementu ściennego i skład betonu modyfikowanego mieszanką dodatków recyklingowych SBR (styrene butadiene rubber) i PET (politereftalan etylenu) oraz skład kompozytowej mieszanki tłumiącej powstałej na bazie tych dwóch materiałów. W celu wykazania efektywności opracowanego rozwiązania w redukcji drgań mechanicznych dokonano oceny wpływu oddziaływania różnych częstotliwości fali mechanicznej na opracowane betonowe murowe elementy ścienne APS i WAPS. Wyniki badań przedstawiono graficznie i wykazano, że wypełnienie otworów nowego typu betonowego murowego elementu ściennego recyklingową mieszanką kompozytową poprawia jego efektywność w ograniczeniu propagacji fal mechanicznych w analizowanym zakresie od 8 do 5000 Hz, pozwalając jednocześnie skutecznie zagospodarowywać materiały pochodzące z recyklingu.
2
Content available remote First PET Studies of a FLASH Proton Beam: Summary and Future Prospects
EN
Objectives: Proton therapy, while highly effective and successful, still lacks a key feature: the ability to assess, in-vivo, the dose and end-point location of irradiations. Known as proton range verification, this capability can be realized by incorporating positron emission tomography (PET) systems in both conventional and emerging modalities, such as FLASH proton therapy. FLASH itself may revolutionize radiation oncology with its purported ability to better spare healthy tissues, but only if the underlying mechanisms can be understood. We summarize our work towards establishing in-beam PET modalities and elucidating the mystery of the FLASH effect. Materials: We've developed a PET scanner designed for live, in-beam imaging during therapeutic proton irradiations that can use short-lived positron emitting species (PES) activated by the beam to validate the range and dose of proton depositions. This scanner is made up of PET modules consisting of arrays of LYSO (lutetium-yttrium oxyorthosilicate) scintillating crystals coupled one-to-one to silicon photomultiplier (SiPM) arrays. These modules are readout by electronics based on the TOFPET2 ASIC platform from PETsys Electronics. Methods: Our collaboration with MD Anderson Cancer Center has given us opportunities to take real in-beam data using a non-clinical beamline capable of delivering FLASH proton irradiations into target phantoms made of polymethyl methacrylate (PMMA), high density polyethylene (HDPE), and water. Data collected both during and afterirradiations were used to perform novel analyses and to reconstruct images of PES activity due to the beam. Results: Exploratory studies, using a subset of our PET scanner, have demonstrated successful data acquisition during and after FLASH beam spills including quantitative imaging and dosimetry of activated phantoms. The full results, explored in this work, are highly promising and prove that in-beam PET can deliver on its goals. Upcoming experiments conducted using both FLASH and conventional beams will employ the full PET scanner and involve a rich experimental program with novel ideas for irradiation targets, beam characterization, and in-depth comparisons of the two irradiation modalities. Conclusions: This work demonstrates the unprecedented proof-of-principle for the capabilities of an in-beam PET scanner for imaging and dosimetry of both conventional and FLASH proton beams. These results open a new PET modality with proton beams which is particularly attractive for FLASH therapy but can serve effectively all proton irradiations, leading to improved treatment monitoring and image-guided therapy.
3
Content available remote Development of correction techniques for the J-PET scanner
EN
Objective: Positron emission tomography (PET) is a widely used medical imaging technique that allows for non-invasive imaging of metabolic processes. However, traditional PET scanners rely on costly inorganic scintillators that limit their accessibility, especially in light of emerging long axial field-of-view devices. The modular J-PET scanner, an innovative alternative, uses 50-cm-long plastic scintillator strips, offering a cost-effective and modular solution. In this study we develop and assess the PET data correction techniques required for quantitative image reconstruction. Methods: We present methods for attenuation correction, random coincidence correction using the delayed time window (DTW) technique and scatter correction based on Monte Carlo simulations. Phantom studies using the NEMA IQ phantom were performed to qualitatively evaluate these corrections. Results: The results demonstrate that our implemented corrections for attenuation and random and scattered coincidences successfully improve the uniformity of tracer distribution in homogenous volumes and significantly reduce undesired activity in cold regions. Despite limitations in sensitivity and axial resolution, the applied correction techniques effectively enhance image quality, providing promising results for future applications. Conclusions: These findings highlight the potential of the modular J-PET system to offer affordable PET imaging and to pave the way for a total-body PET scanner based on plastic scintillators. Future work will focus on quantitative validation and the implementation of these corrections for human subject imaging.
EN
Objectives: This paper presents the prospects for increasing the availability of PET diagnostics by combining low-cost, lightweight and easily portable modular J-PET with the 44Ti/44Sc generator. Methods: J-PET is constructed based on the low-cost axially arranged plastic scintillators that may enable the construction of PET scanners 5 to 10 times less expensive compared to current PET systems, which are based on crystal scintillators. Development of the radionuclide 44Ti/44Sc generator with the 60-year half-lifetime would enable long-term onsite production of 44Sc labelled radiopharmaceuticals, eliminating the need for extensive and costly infrastructure typically associated with nuclear medicine. Presently applied 68Ge/68Ga generators with the 270 days half- -lifetime require renewal every year. The 44Ti/44Sc generator could, in principle, be purchased once every half century. Results: The lightweight and portable J-PET scanner, combined with the 44Ti/44Sc generator, can be deployed in remote and underserved regions, thus democratising access to advanced medical-imaging techniques. Conclusions: This novel concept shows the transformative potential of combining innovative J-PET technology with the 44Ti/44Sc generator to make advanced diagnostics more accessible and affordable worldwide, especially benefiting millions of patients in low- and medium-income countries, and driving further innovations in medical imaging.
EN
A concept of producing reinforcing bars for concrete elements from waste polyethylene terephthalate (PET) bottles is presented in the paper. The proposed technology of production harnesses strips of PET cut from bottles and thermal treatment. Finally, a sand-resin coating is applied to the composite bars. Produced bars can be differentiated by utilising different numbers of strips influencing the diameter of a bar. The key mechanical properties of the bars containing 3 to 8 strips were tested during the research program. Maximum loadings and displacements were established. Problems regarding the future application of the bars in question were discussed. Areas of need for further research were pointed out.
6
Content available remote The influence of the electrode material on the dielectric properties of PET films
EN
This paper presents the influence of the measuring electrode material on the dielectric properties of polyethylene terephthalate. We show that volume resistivity, surface resistivity, relative permittivity and the dielectric loss factor of PET films are a function of the electrode material used. We also evaluate the effect of thermal aging on the tested material parameters.
PL
Przedstawiono wpływ materiału elektrod pomiarowych na właściwości dielektryczne politereftalanu etylenu. Stwierdzono, że rezystywność skrośna, rezystywność powierzchniowa, względna przenikalność elektryczna oraz współczynnik strat dielektrycznych folii PET są funkcją zastosowanego materiału elektrod. Oceniono wpływ starzenia termicznego na badane parametry materiałowe.
EN
The photonic crystal fibers (PCFs) are designed based on optical material by periodic changes in its dielectric constant, in which a wide platform of applications in numerous domains has been provided. Many optical communication devices that are designed on the PCFs have reported high throughput in their showing, by making a significant contribution in compactness, miniature sizes and fast switching, which compose of alternate high and low refractive index materials. In this study, the PCF and the effects of translational symmetry on their properties are introduced. Two dimensional photonic crystals (2D-PC) are studied in detail, and a new method for scattering photons off finite and infinite PCFs is developed. In this regard, the conventional fabrication methods of PCFs have been studied and a new technique for vertical etching of Polyethylene Terephthalate (PET) by ultraviolet radiation has been introduced as a powerful and economical method to implement these structures. Also, the potential of the method for fabricating higher precision and smaller dimensions has been examined. To ensure the accuracy of the proposed method, simulation was carried out using Matlab software, in which the magnitude of the light source and then the angular impact of the UV irradiation beams are investigated. In this study, the finite difference time domain (FDTD) method is accomplished for analysis of photonic-band gap (PBG) -based polarization.
PL
Światłowody fotoniczne (PCF) są projektowane w oparciu o materiał optyczny poprzez okresowe zmiany jego stałej dielektrycznej, co zapewnia szeroką platformę zastosowań w wielu dziedzinach. Wiele optycznych urządzeń komunikacyjnych zaprojektowanych na PCF odnotowało wysoką przepustowość podczas ich wyświetlania, wnosząc znaczący wkład w zwartość, miniaturowe rozmiary i szybkie przełączanie, które składają się z naprzemiennych materiałów o wysokim i niskim współczynniku załamania światła. W tym badaniu przedstawiono PCF i wpływ symetrii translacyjnej na ich właściwości. Szczegółowo badane są dwuwymiarowe kryształy fotoniczne (2D-PC) i opracowywana jest nowa metoda rozpraszania fotonów na skończonych i nieskończonych PCF. W związku z tym zbadano konwencjonalne metody wytwarzania PCF i wprowadzono nową technikę pionowego trawienia politereftalanu etylenu (PET) za pomocą promieniowania ultrafioletowego jako wydajną i ekonomiczną metodę wdrażania tych struktur. Zbadano również potencjał metody do wytwarzania wyrobów o większej precyzji i mniejszych gabarytach. Aby zapewnić dokładność proponowanej metody, przeprowadzono symulację z wykorzystaniem oprogramowania Matlab, w którym bada się wielkość źródła światła, a następnie kątowe oddziaływanie wiązek promieniowania UV. W tym badaniu metoda domeny różnic skończonych w dziedzinie czasu (FDTD) została wykorzystana do analizy polaryzacji opartej na fotonicznej przerwie wzbronionej (PBG).
EN
This research explores the viability of converting discarded Polyethylene Terephthalate (PET) plastic waste into a valuable resource through the implementation of pyrolysis and refuse-derived fuel (RDF) technologies. The objective is to assess the potential of PET charcoal waste as an efficient source for RDF generation, surpassing the energy recovery and recycling potential of PET waste. The study introduces three RDF variants: RDF PET100, RDF PET50, and RDF PET0. RDF PET100 is comprised entirely of PET charcoal, RDF PET50 combines 50% PET charcoal with 50% wood debris, and RDF PET0 consists entirely of wood debris. Comprehensive assessments of water content, ash content, and calorific value were conducted to evaluate the quality of these RDF formulations. Results indicate that RDF PET100 exhibits a water content of 2.63%, ash content of 0.73%, and calorific value of 5,976 MJ/kg. Similarly, RDF PET50 showcases a water content of 3.6%, ash content of 1.05%, and calorific value of 5,587 MJ/kg. RDF PET0 presents a water content of 7.51%, ash content of 1.36%, and calorific value of 4,198 MJ/kg. The outcomes underline the potential of PET plastic waste repurposing through RDF and pyrolysis techniques. Particularly, RDF PET100 emerges as a high-caliber fuel option characterized by its minimal water and ash content, coupled with a substantial calorific value. This innovation holds promise in mitigating plastic waste challenges, particularly pertinent in the context of Indonesia.
PL
W artykule przedstawiono wyniki prac projektowych i badawczych, których celem było wytworzenie lekkiego kruszywa ultrakompozytowego (UCLA - ultracomposite lightweight aggregate) w rezultacie połączenia odpadów pochodzących z różnych strumieni. W wyniku procesu odpowiednio przeprowadzonej obróbki termicznej w specjalnie zaprojektowanych warunkach, wytworzono kompozyt w postaci granulek odpowiadających frakcji kruszywowej 2-8 mm. Uzyskano różne rodzaje kruszyw lekkich wykonanych przy użyciu różnych drobnoziarnistych wypełniaczy mineralnych, których podstawowe właściwości zostały zbadane i zaprezentowane. Dodatkowo zostały wykonane wstępne badania aplikacyjne tych kruszyw w funkcji składnika kompozytu betonowego. Badania przeprowadzono na zmodyfikowanych zaprawach normowych powszechnie wykonanych według zaleceń normy PN-EN 196-1, gdzie 25% objętości piasku normowego zostało zastąpione sztucznym kruszywem ultrakompozytowym.
EN
In this article authors presented research and project results which target was production of lightweight aggregates as a result of connect waste from different sources. During works about process and technology production new ecological aggregate was used physical properties of polymers and their high viscosity in phase of melting. As a result of thermal treatment in special production conditions was created composite in the granules shape. Obtained coarse aggregates 2/8 mm based on different waste mineral filler. All aggregates was tested in basic properties scope and presented. Additionally preliminary application tests those aggregates was made like function of concrete’s ingredient. The research were carried out on modified standard mortars commonly made according to the recommendations of the PN-EN 196-1 standard, where 25% of the volume of standard sand was replaced with artificial ultra-composite aggregate.
EN
The modular J-PET scanner, comprising 24 compact and versatile modules, each consisting of 13 plastic strips with four SiPM detectors at the ends, represents a powerful tool for clinical applications in nuclear medical imaging. This study presents preliminary results from the exploration of simultaneous dual-isotope imaging using the modular J-PET system. Our approach involved two isotopes: 68Ge, characterized by a ringlike shape, and 22Na, exhibiting a point-like shape. The imaging was based on double-coincidence and triple-coincidence events. In the double coincidence case, both isotopes contributed comparably, whereas in the triple coincidence case 22Na dominated due to the prompt gamma being emitted with 100% of positron emissions, unlike 68Ga, where the prompt gamma was emitted in only 1.3% of cases after positron emission. In this work we present direct 2γ images determined for two-signal events and images for three-signal events, with two signals from annihilation photons and one from a prompt gamma. These results showcase the preliminary findings from simultaneous dual-isotope imaging of 68Ga and 22Na isotopes using the modular J-PET scanner, which will be presented and discussed.
EN
The positronium imaging technique represents a potential enhancement of the PET imaging method. Its core principle involves employing a β+ radiation source that emits additional gamma (γ) quanta referred to as prompt gamma. Our aim is to evaluate the capability to differentiate between annihilation and prompt gamma emissions, a vital aspect of positronium imaging. For this purpose, the selected isotopes should enable high efficiency and purity in detecting both prompt gamma and annihilation gamma. The assessment of the efficiency in identifying prompt and annihilation photons for various isotopes, which are potentially superior candidates for β++ γ emitters, is conducted through toy Monte-Carlo simulation utilizing the cross-section formula for photon-electron scattering. In this article, we have performed calculations for efficiency and purity values across different isotopes under ideal conditions and examined how these values evolve as we incorporate the fractional energy resolution into the analysis. Ultimately, the primary goal is to determine the energy threshold that optimizes both efficiency and purity, striking a balance between accurately identifying and recording events of interest while minimizing contamination from undesired events.
12
Content available remote Estimating influence of positron range in proton-therapy-beam monitoring with PET
EN
The application of PET scanners to proton-beam-therapy monitoring is a promising solution to obtain the range of the beam and hence the positions of a Bragg peak - maximum dose deposition point. A proton beam induces nuclear reactions in the tissue, leading to the production of isotopes that emit β+ radiation. This enables the imaging of the density distribution of β+ isotopes produced in the body, allowing the reconstruction of the proton beam range. Moreover, PET detectors may open the possibility for in-beam monitoring, which would offer an opportunity to verify the range during irradiation. PET detectors may also allow positronium imaging, which would be the indicator of the tissue conditions. However, the image of annihilation points does not represent the range of the proton beam. There are several factors influencing the translation from annihilation points to obtain the Bragg peak position. One of them is the kinetic energy of the positron. This energy corresponds to some range of the positron within the tissue. In this manuscript we estimate positron energy and its range and discuss its influence on proton therapy monitoring.
13
EN
In this article, we present the modern state of development of boron neutron capture therapy (BNCT) for cancer treatment using compact neutron generators. In the introduction we consider the main advantages and problems of the BNCT method, the main approaches and directions for building neutron sources, the development of chemical materials - boron-containing delivery agents and the control of irradiation of malignant tumours and healthy tissues. In the main part of the article we consider the main structures of neutron generators that can be effective for applying in BNCT. The development and building of a prototype of a compact neutron generator is also described.
EN
Dose delivery in proton beam therapy requires significant effort for in vivo verification. PET is considered as one of the most precise methods for such verification using short- -lived radionuclides. One of the newer approaches in proton therapy is based on FLASH therapy, when a 40-60 Gy absorbed dose could be delivered in millisecond time intervals. For this very promising type of therapy a very important task is to reliably identify the beam stopping position within the corresponding organ with a tumor in the patient’s body. This could be done if the beam proton energy in the body is still above the threshold of the corresponding nuclear reaction, in the outgoing channel of which will be produced positron-emitting nuclei. In this work we consider the production of oxygen radionuclides emitting positrons 14O (the half-life 70.6 s) and 15O (the half-life 122.2 s). Using the TALYS code, we calculated cross sections of proton-induced nuclear reactions on 14N and 16O, leading to the formation of 14,15O with the application of a well- -working optical model. In addition, we calculated total gamma-production and average gamma-emission energy for incident proton energy 150 MeV.
EN
A great deal of packaging made of PET is observed in logistics supply chains, and the article is mainly concerned with food – bottles. Implementing the EU’s “zero-waste” guidelines implies action on the part of producers of packaging and food for B2C distribution to find new solutions to enable the above-mentioned stakeholders in the logistics supply chain to balance the business mentioned above parties – taking into account environmental protection. The article discusses the tasks and possibilities under the above conditions of a new type of “RECYCLER” companies, which, at the end of the life of PET packaging, i.e. after the foodstuffs in PET bottles have been consumed, produce a recyclate and return it to reproduction. In several journals, including, e.g. (Połednik et al. 2016, Topiarzová et al. 2011), respecting good recycling practices – there is an ongoing discussion on the sense of introducing reusable packaging, deposits, etc. This article discusses the barriers to recovery in a multi-level plastics recovery system, with specific reference to the operation of a PET bottle recycling line, and presents a pre-verified concept for a method to increase the efficiency of separating PET bottles from the plastics fraction in a multi-level waste separation system.
PL
W artykule przedstawiono wyniki prac projektowych i badawczych, których celem było wytworzenie lekkiego kruszywa ultrakompozytowego (UCLA - ultracomposite lightweight aggregate) w wyniku połączenia odpadów pochodzących z różnych źródeł. Opracowana technologia wytwarzania pozwoliła na wykorzystanie odpadów pochodzących z termoplastycznych polimerów (PET) oraz mineralnych odpadów z procesów spalania, i pozyskanie kruszywa lekkiego mogącego znaleźć powszechne zastosowanie w budownictwie. W trakcie prac nad technologią wytwarzania nowego, ekologicznego kruszywa wykorzystano właściwości fizyczne termoplastycznych tworzyw sztucznych, w tym ich dużą lepkość w stanie stopionym. W wyniku odpowiednio przeprowadzonej obróbki termicznej w specjalnie zaprojektowanych warunkach wytworzono kompozyt w postaci granulek odpowiadających frakcji kruszywowej 2 - 8 mm. Uzyskano różne rodzaje kruszyw lekkich wykonanych przy użyciu różnych drobnoziarnistych wypełniaczy mineralnych - ubocznych produktów spalania, których podstawowe właściwości zostały zbadane i zaprezentowane.
EN
The paper presents the results of design and research work aimed at producing ultracomposite lightweight aggregate (UCLA) as a result of combining waste from different sources. The developed production technology allowed to utilize waste from thermoplastic polymers (PET) with mineral waste from combustion processes, and to produce a lightweight aggregate that can be widely used in construction. During the development of the technology to produce a new, ecological aggregate, the physical properties of thermoplastics and their high viscosity in the molten state were used. As a result of a properly conducted thermal treatment in specially designed conditions, a composite in the form of granules corresponding to an aggregate fraction of 2 - 8 mm was produced. Different types of lightweight aggregates made with various fine-grained mineral fillers - by-products of combustion - were obtained, the basic properties of which were studied and presented.
EN
Plastics play an important role in our lives due to their versatility, lightness and low production cost. They can be found in almost every industry such as automotive, construction, packaging, medical, and engineering applications among others. Polyethylene terephthalate (PET) is one of the most consumed plastics worldwide in the packaging sector, which is why its useful life is usually very short, causing serious problems due to high disposal in the environment and urban landfills. The thermochemical degradation of PET has been studied by some researchers and it has been found that its degradation products are of high added value, which is why this work focuses on presenting the results obtained in the literature.
EN
Nowadays, Medical imaging modalities like Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Single Photon Emission Tomography (SPECT), and Computed Tomography (CT) play a crucial role in clinical diagnosis and treatment planning. The images obtained from each of these modalities contain complementary information of the organ imaged. Image fusion algorithms are employed to bring all of this disparate information together into a single image, allowing doctors to diagnose disorders quickly. This paper proposes a novel technique for the fusion of MRI and PET images based on YUV color space and wavelet transform. Quality assessment based on entropy showed that the method can achieve promising results for medical image fusion. The paper has done a comparative analysis of the fusion of MRI and PET images using different wavelet families at various decomposition levels for the detection of brain tumors as well as Alzheimer’s disease. The quality assessment and visual analysis showed that the Dmey wavelet at decomposition level 3 is optimum for the fusion of MRI and PET images. This paper also compared the results of several fusion rules such as average, maximum, and minimum, finding that the maximum fusion rule outperformed the other two.
EN
The interfacial structure and binding forces of polytrimethylene terephthalate/polyethylene terephthalate filament were investigated through the methods of Carbon-13 nuclear magnetic resonance (13C-NMR), differential scanning calorimeter (DSC), scanning electron microscopy (SEM) and optical microscopy. When two molten polymers met during the spinning process, an interface layer between the PTT and PET components formed and played an important role in binding the two components together. When the blending time was sufficient, an ester-interchange reaction took place with the generation of the copolymer. The PET recrystallisation was observed in the DSC curve under the influence of entangled PTT molecular chains. The morphology of the cross-section and side view proved that the linear boundary line was short and weaker in binding without a chemical bond and molecular diffusion. Side-by-side bi-component fiber and split-type fiber was able to be controllably spun by adjusting the spinning parameters.
EN
Positron-electron annihilation in living organisms occurs in about 30% via the formation of a metastable ortho-positronium atom that annihilates into two 511 keV photons in tissues because of the pick-off and conversion processes. Positronium (Ps) annihilation lifetime and intensities can be used to determine the size and quantity of defects in a material's microstructure, such as voids or pores in the range of nanometers. This is particularly true for blood clots. Here we present pilot investigations of positronium properties in fibrin clots. The studies are complemented by the use of SEM Edax and micro-computed tomography (µCT) to evaluate the extracted thrombotic material's properties. µCT is a versatile characterization method offering in situ and in operando possibilities and is a qualitative diagnostic tool. With µCT the presence of pores, cracks, and structural errors can be verified, and hence the 3D inner structure of samples can be investigated.
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