22 research outputs found

    Reprint of: Time Domain Impedance Modelling and Applications

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    AbstractToday, there is a high, often not fully evolved potential of noise attenuation by passive acoustic treatments. Current numerical methods are able to help developing optimal treatments. Thus, the simulation of acoustic lining in aeroengines is one of the core objectives for the development of modern CAA solvers. Here, the opportunities of the Extended Helmholtz Resonator (EHR) model of Rienstra in the time domain in this design and optimisation process are demonstrated. The optimization of a lining for a specific application as the obvious objective is still out of reach for many cases with current numerical resources. However, the model allows the optimisation towards the dissipation characteristics in an impedance flow tube measurement with a physical liner sample, which provides the numerical parameters of the liner for high fidelity CAA simulations. Moreover, the model parameters are related to the cell geometry and face sheet of the liner panel. An example is provided for the purely numerical prediction of the attenuation in the complex flow of an aeroengine duct. This is demonstrated by considering the resulting parameters in modal axisymmetric and three dimensional simulations of the rearward sound radiation from a lined bypass duct. The example demonstrates, that the optimisation of the liner properties is not achievable in a justifiable time, even if simplified two dimensional conditions are considered. A possible solution to this problem is to use the computational power of a graphics processing unit (GPU). The development of pixel shaders which implement a large number of parallel processors into the GPU, shows a much more agile growth than any CPU based system does. As an outlook, a platform independent implementation of a GPU based CAA solver with impedance boundary condition and the capability to handle axisymmetric duct geometries is presented. It demonstrates a speed up by a factor>100

    Time domain impedance modelling and applications

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    AbstractToday, there is a high, often not fully evolved potential of noise attenuation by passive acoustic treatments. Current numerical methods are able to help developing optimal treatments. Thus, the simulation of acoustic lining in aeroengines is one of the core objectives for the development of modern CAA solvers. Here, the opportunities of the Extended Helmholtz Resonator (EHR) model of Rienstra in the time domain in this design and optimisation process are demonstrated. The optimization of a lining for a specific application as the obvious objective is still out of reach for many cases with current numerical resources. However, the model allows the optimisation towards the dissipation characteristics in an impedance flow tube measurement with a physical liner sample, which provides the numerical parameters of the liner for high fidelity CAA simulations. Moreover, the model parameters are related to the cell geometry and face sheet of the liner panel. An example is provided for the purely numerical prediction of the attenuation in the complex flow of an aeroengine duct. This is demonstrated by considering the resulting parameters in modal axisymmetric and three dimensional simulations of the rearward sound radiation from a lined bypass duct. The example demonstrates, that the optimisation of the liner properties is not achievable in a justifiable time, even if simplified two dimensional conditions are considered. A possible solution to this problem is to use the computational power of a graphics processing unit (GPU). The development of pixel shaders which implement a large number of parallel processors into the GPU, shows a much more agile growth than any CPU based system does. As an outlook, a platform independent implementation of a GPU based CAA solver with impedance boundary condition and the capability to handle axisymmetric duct geometries is presented. It demonstrates a speed up by a factor > 100

    From tests of discrete symmetries to medical imaging with J-PET detector

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    We present results on CPT symmetry tests in decays of positronium performed with the precision at the level of 104^{-4}, and positronium images determined with the prototype of the J-PET tomograph. The first full-scale prototype apparatus consists of 192 plastic scintillator strips readout from both ends with vacuum tube photomultipliers. Signals produced by photomultipliers are probed in the amplitude domain and are digitized by FPGA-based readout boards in triggerless mode. In this contribution we report on the first two- and three-photon positronium images and tests of CPT symmetry in positronium decays

    ProTheRaMon : a GATE simulation framework for proton therapy range monitoring using PET imaging

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    Objective. This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland. Approach. The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user’s needs and specific settings of a given proton therapy facility and PET scanner design. Main results. ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized. Significance. We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github (Borys et al 2022)

    Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

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    Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

    The Jewish Elements in the Catholic Liturgy

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    Autor zajmuje się analizowaniem związków liturgicznych między katolicyzmem a judaizmem, a konkretnie żydowskich korzeni katolickiej Mszy Novus Ordo (posoborowej). Za ramę pracy przyjęty został Mszał Rzymski dla Diecezji Polskich.The author analizes liturgical connections between Catholicism and Judaism, specifically Jewish roots of the Catholic Novus Ordo Mass (post-Vaticanum II). Roman Missal for Polish Dioeceses was established as the thesis' framework

    Analiza środowiskowa nowatorskich sorbentów do sorpcji rtęci

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    The reduction of mercury emissions in currently existing coal-based power plant solutions by each method i.e. preliminary, primary and secondary (consisting of introducing coal into the combustion chamber and then removing mercury from the combustion gases arising from the combustion process) does not solve the problem of achieving the required limits by power plants. Therefore, the need has arisen to look for new, effective solutions. The results presented in the work concern the analysis of environmental benefits for the use of zeolites obtained from by-products of coal combustion such as fly ash (from hard coal and lignite) in technologies for removing gaseous forms of mercury. The tested zeolites were silver-modified X-type structures. The reference material in the considerations was active carbon impregnated with bromine – a commercially available sorbent on the market. The article considers environmental benefits resulting from the use of tested zeolites taking the product life cycle, sorbent efficiency and the possibility of its regeneration compared to activated carbon (AC/Br) into account. The LCA analysis was performed taking the estimated material and energy balances of the manufacturing processes into account. When comparing the production process of type X zeolite materials on the processing line and activated carbons in the amount necessary to capture 375 g Hg from exhaust gases, the LCA analysis showed that zeolites contribute to a lower potential impact on the environment. The advantage is that 5 times less zeolite sorbent than activated carbons is needed to capture the same amount of mercury. In addition, zeolite materials can be regenerated, which extends their life time.Redukcja emisji rtęci w obecnie istniejących rozwiązaniach elektrowni bazujących na węglu zarówno metodami wstępnymi, jak i metodami pierwotnymi oraz metodami wtórnymi polegającymi na wprowadzeniu węgla do komory paleniskowej, a następnie usuwaniu rtęci z gazów wylotowych powstałych w procesie spalania, nie rozwiązuje problemu osiągnięcia wymaganych limitów przez elektrownie, w związku z czym istnieje potrzeba poszukiwania nowych, efektywnych rozwiązań. Przedstawione w pracy wyniki dotyczą analizy korzyści środowiskowych dla zastosowania zeolitów otrzymywanych z ubocznych produktów spalania, jakimi są popioły lotne (z węgla kamiennego i brunatnego) w technologiach usuwania gazowych form rtęci. Badane zeolity stanowiły struktury typu X modyfikowane srebrem. Materiałem referencyjnym w rozważaniach był węgiel aktywny impregnowany bromem – komercyjnie dostępny na rynku sorbent. W artykule rozważono korzyści środowiskowe wynikające z zastosowania badanych zeolitów uwzględniając cykl życia produktu, wydajność sorbentu oraz możliwość jego regeneracji w porównaniu do węgla aktywnego (AC/Br). Analizę LCA dokonano, uwzględniając oszacowane bilanse materiałowe i energetyczne procesów wytwarzania. Przy porównaniu procesu produkcji materiałów zeolitowych typu X na linii technologicznej oraz węgli aktywnych w ilości niezbędnej do wychwycenia z gazów odlotowych 375 g Hg, analiza LCA wykazała, iż zeolity przyczyniają się do mniejszego potencjalnego wpływu na środowisko. Zaletą jest fakt, iż do wychwycenia tej samej ilości rtęci niezbędne jest 5 razy mniej sorbentu zeolitowego niż węgli aktywnych. Ponadto materiały zeolitowe dodatkowo można regenerować, co wydłuża ich czas życia

    Influence of Conditioning Temperature on Defects in the Double Al<sub>2</sub>O<sub>3</sub>/ZnO Layer Deposited by the ALD Method

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    In this work, we present the results of defects analysis concerning ZnO and Al2O3 layers deposited by atomic layer deposition (ALD) technique. The analysis was performed by the X-band electron paramagnetic resonance (EPR) spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) methods. The layers were either tested as-deposited or after 30 min heating at 300 °C and 450 °C in Ar atmosphere. TEM and XPS investigations revealed amorphous nature and non-stoichiometry of aluminum oxide even after additional high-temperature treatment. EPR confirmed high number of defect states in Al2O3. For ZnO, we found the as-deposited layer shows ultrafine grains that start to grow when high temperature is applied and that their crystallinity is also improved, resulting in good agreement with XPS results which indicated lower number of defects on the layer surface

    Variation in Tocochromanols Level and Mycotoxins Content in Sweet Maize Cultivars after Inoculation with Fusarium verticillioides and F. proliferatum

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    A major problem in maize production is the contamination of the grain with Fusarium spp., mainly F. proliferatum and F. verticillioides and their secondary metabolites—mycotoxins. Under biotic stress conditions, caused by a fungal pathogen, plants initiate a series of defense mechanisms that may cause quantitative and qualitative changes in the composition of phenolic compounds. We analyzed the resistance of four sweet maize cultivars (Syngenta Group: Overland, Sweetstar, GSS 8529, Shinerock) to the infection with Fusarium verticillioides and F. proliferatum isolates, along with fumonisins B1, B2, and B3 grain contamination and the levels of tocopherols and tocotrienols accumulated. Differences in ear rot levels were found between the cultivars and isolates used. The phenotypic evaluation positively correlated with the concentrations of fumonisins. The results obtained also indicate a significant dependence on tocochromanols content in sweet maize cultivars tested on the infection of plants with Fusarium isolates and fumonisin biosynthesis. Further studies are needed to investigate the mechanisms of the plant reaction and the effect of different levels of tocopherols and tocotrienols on Fusarium resistance and grain contamination with mycotoxins
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