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Medical staff monitoring in interventional cardiology: over apron dosemeter placement based on measurements and simulations
No full textInterventional cardiology is characterized by high radiation exposure for both the patient and the operator. Adequate shielding and monitoring of the operator are fundamental to comply with radiation protection principles. In a previous work, the effect on the dose of the dosemeter position on the chest was studied. In this paper, the investigation has been completed, employing an anthropomorphic thorax phantom, equipped with arms. Although there are differences between the Monte Carlo simulations and the measurements, similar trends are observed, showing that the reduction in dose, due to the arms, is between 20 and 60%, compared with the situation without arms. For that reason, considering a dosemeter placed on the chest, the upper position, which is the least affected by the arms, should be preferred while the extreme lateral position, near the armpit, should be avoided
Negative triangularity scenarios: from TCV and AUG experiments to DTT predictions
Get PDFExperiments, gyrokinetic simulations and transport predictions were performed to investigate if a negative triangularity (NT) L-mode option for the Divertor Tokamak Test (DTT) full-power scenario would perform similarly to the positive triangularity (PT) H-mode reference scenario, avoiding the harmful edge localized modes (ELMs). The simulations show that a beneficial effect of NT coming from the edge/scrape-off layer (SOL) region ρ tor > 0.9 is needed to allow the actual NT L-mode option to perform like the PT H-mode. Dedicated experiments at TCV and AUG, with DTT-like shapes, show an optimistic picture. In TCV, experiments indicate that even with the relatively small triangularity of the DTT NT scenario, a large beneficial effect of NT comes from the plasma edge and SOL, allowing NT L-modes to outperform PT L-modes with the same power input, reaching the same central pressures as PT H-modes with twice as much applied heating power. For AUG, NT plasmas go into H-mode more easily than for TCV, but always present much smaller pedestals compared with PT plasmas with the same input power, showing a much weaker or absent ELM activity. However, NT has a smaller beneficial effect for AUG than for TCV, with NT pulses outperforming PT pulses with the same input power only for an ECRH-only case with relatively low input power. For the considered AUG cases, PT pulses perform better than NT ones at higher ECRH power or with mixed NBI and ECRH power. Based on this analysis, the NT option is a viable alternative for the DTT full power scenario, providing high performance plasmas with reduced or absent ELMs
Corrosion resistance of HiPIMS tungsten and tungsten-aluminium coatings in contact with liquid Sn
Get PDFPure‐tungsten and tungsten-aluminium films deposited by high power impulse magnetron sputtering (HiPIMS) on copper‐chromium‐zirconium substrates were investigated as protective coatings against liquid tin corrosion, a critical issue for nuclear fusion applications. The growth of pure‐tungsten coatings was controlled by using a negative substrate bias synchronized to the HiPIMS pulse onset, resulting in columnar films with various degree of compactness and crystallinity according to the set bias amplitude (0, 400 and 800 V). Differently, the co-sputtering of W and Al favored the formation of an amorphous layer with a compact morphology. During liquid tin corrosion experiments at 400 °C for up to 600 min, all produced coatings were not dissolved, but different protective performances were observed after localized liquid tin interaction. Pure-W coated samples suffered from tin penetration after brittle failure of the protective layer. On the contrary, under the same experimental condition, W–Al coatings proved to be effective in limiting liquid tin attack
Nota su alcuni neurotteri raccolti con trappole attrattive aree in Sardegna (Raphidioptera, Raphidiidae; Neuroptera, Chrysopidae, Mantispidae, Myrmeleontidae, Nevrorthidae)
No full textFaunal data and some considerations relating to the Neuropterida collected during a sampling campaign conducted in Sardinia in various localities with attractive traps located in the arboreal canopy are reported. This study made it possible to confirm the presence on the island of species previously considered dubious like Cunctochrysa albolineata or rarely collected such as Neuroleon microstenus or N. nemausiensis
Gravure Printed Composites Based on Lithium Manganese Oxide: A Study Case for Li-Ion Batteries Manufacturing
No full textAimed by the increasing interest in the field of printed batteries, the study recently has demonstrated the possibility to successfully gravure print composites working as electrodes for Li-ion batteries. Gravure is one of the most appealing printing technique for the mass production of functional layers due to its unique ability to couple high speed and high resolution. The ink formulation is challenging because of the low viscosity ink requirement which makes difficult to obtain the proper functionality of the layer, especially in case of composite materials like electrodes, and a mass loading suitable for practical applications. Changing a material of the composite implies the study of a new gravure ink in terms of formulation and preparation process. Ruling the ink preparation can strongly decrease the process time promoting the industrial use of the gravure printing. For this reason, the study proposes a methodology, mainly based on the capillary number, able to suggest the best receipt for each specific ink. Here, a study case is reported, using lithium manganese oxide (LMO) as active material for the gravure printed cathode manufacturing. Such work gives the possibility to show the proposed methodology for ruling the ink preparation
PARP1 inactivation increases regulatory T / Th17 cell proportion in intestinal inflammation. Role of HMGB1
Get PDFInflammatory bowel diseases (IBD) are chronic relapsing disorders with increasing prevalence. Knowledge gaps still limit the possibility to develop more specific and effective therapies. Using a dextran sodium sulfate colitis mouse model, we found that inflammation increased the total number and altered the frequencies of leukocytes within colon mesenteric lymph nodes (cMLNs). Although the inflammation reduced the frequency of regulatory T (Treg) cells, their absolute numbers were increased. Increased frequency of colitogenic Th17 cells was also observed. Noteworthy, untreated mice lacking Poly(ADP-ribose)-Polimerase-1 functional gene (PARP-1KO) displayed higher frequency of Treg cells and lower percentage of Th17 cells in cMLNs. In colitic PARP-1KO mice the inflammation driven expansion of the Foxp3 Treg population was more pronounced than in WT mice. Conversely, colitis increased Th17 cells to a lower extent in PARP-1KO mice compared with WT mice, resulting in a more protective Treg/Th17 cell ratio. Consequently PARP-1KO mice developed less severe colitis with reduced expression of inflammatory cytokines. In ex vivo experiments PARP-1KO and WT CD11c dendritic cells (DCs) promoted naïve CD4 T cell differentiation differently, the former sustaining more efficiently the generation of Treg cells, the latter that of Th17 cells. Addition of HMGB1 B box or of dipotassium glycyrrhizate, which sequesters extracellular HMGB1, revealed a role for this alarmin in the regulation exerted by PARP-1 on the stimulating vs. tolerogenic function of DCs during colitis. Moreover, a higher percentage of CD11c DC from PARP-1KO mice expressed CD103, a marker associated with the ability of DC to induce Treg cells, compared with WT DC. Conversely, PARP-1KO DC were including a reduced percentage of CX3CR1+ DC, described to induce Th17 cells. These findings were observed in both splenic and colon lamina propria DC
Structural integrity evaluation of the DTT plasma facing unit using detailed CFD and thermo-mechanical analyses
Get PDFA new Divertor Tokamak Test (DTT) facility is currently being built in Italy to investigate different divertor configurations under different plasma scenarios. The divertor and in particular its target, consisting of Plasma Facing Units (PFUs), is exposed to high heat loads due to plasma fluence. In this paper, the structural integrity of the PFU is evaluated for a reference Single Null (SN) divertor configuration under three different plasma scenarios. A comprehensive structural integrity analysis has been carried out in three stages. In the first stage, computational fluid dynamic (CFD) analyses of the divertor's PFU with a cooling channel were performed at three different heat loads corresponding to three plasma scenarios. The temperature fields calculated by the CFD analyses were then used as input for the second stage, in which thermo-mechanical simulations were performed to predict the stresses and displacements in the PFU. Due to the high local heat loads, high stresses or even yielding are expected in the PFU's structural components. Therefore, in the third stage, the structural integrity of critical cross-sections has been verified using the Structural Design Criteria for In-vessel Components (SDC-IC). It has been demonstrated that structural components of the PFU are able to withstand the expected loads, although some non-structural components experienced yielding while not exceeding the critical values
Diagnostica energetica di fasci di protoni da fotoluminescenza di centri di colore in cristalli di fluoruro di litio: correzione del disallineamento angolare tra fascio e cristallo
Get PDFLa fotoluminescenza da centri di colore nei cristalli di fluoruro di litio (LiF) è sfruttata per caratterizzare lo spettro energetico di fasci di protoni accelerati nell’intervallo di energie da qualche MeV a diverse decine di MeV. L’approccio, applicato negli ultimi anni con successo all’acceleratore lineare TOP-IMPLART, è stato sviluppato dal nostro laboratorio e consiste di diverse fasi: (a) irraggiamento a incidenza radente del cristallo di LiF con il fascio di protoni; (b) visualizzazione in un microscopio a fluorescenza della map-pa di fotoluminescenza emessa dai centri di colore formatisi nel cristallo per l’interazione ionizzante con i protoni; (c) elaborazione di tale mappa per ricavare una stima dello spettro energetico del fascio di pro-toni. In quest’ultima fase, il ricorso a un modello analitico per il calcolo di curve di Bragg di protoni acce-lerati in cristalli di LiF, opportunamente corretto per includere la fuoriuscita di protoni dal cristallo dovuta alla diffusione multipla di Coulomb, permette l’esecuzione di un algoritmo per determinare lo spettro energetico del fascio. In questo Rapporto Tecnico si propone un aggiornamento di tale algoritmo, me-diante elaborazione esterna con il software Monte Carlo FLUKA, per correggere l’effetto di un eventuale disallineamento angolare, nella prima fase, tra fascio di protoni e cristallo di LiF.Photoluminescence emitted by color centers within lithium fluoride (LiF) crystals is utilized to characterize the energy spectrum of accelerated proton beams ranging from a few MeV to several tens of MeV. This method, successfully employed at the TOP-IMPLART linear accelerator, was developed by our laborato-ry and involves several stages: (a) exposing the LiF crystal to the proton beam at grazing incidence; (b) visualizing the photoluminescence map emitted by the color centers formed in the crystal due to ionizing interactions with protons using a fluorescence microscope; (c) processing this map to estimate the ener-gy spectrum of the proton beam. In this final phase, the use of an analytical model for the calculation of Bragg curves of protons accelerated in LiF crystals, appropriately corrected to include the exit of protons from the crystal due to multiple Coulomb scattering, allows the execution of an algorithm to determine the energy spectrum of the beam. This Technical Report proposes an update of this algorithm, through external processing with the Monte Carlo FLUKA software, to correct the effect of a possible angular misalignment, in the first phase, between the proton beam and the LiF crystal
Recent Advances in Graphene Adaptive Thermal Camouflage Devices
Get PDFThermal camouflage is a highly coveted technology aimed at enhancing the survivability of military equipment against infrared (IR) detectors. Recently, two-dimensional (2D) nanomaterials have shown low IR emissivity, widely tunable opto-electronic properties, and compatibility with stealth applications. Among these, graphene and graphene-like materials are the most appealing 2D materials for thermal camouflage applications. In multilayer graphene (MLG), charge density can be effectively tuned through sufficiently intense electric fields or through electrolytic gating. Therefore, MLG’s optical properties, like infrared emissivity and absorbance, can be controlled in a wide range by voltage bias. The large emissivity modulation achievable with this material makes it suitable in the design of thermal dynamic camouflage devices. Generally, the emissivity modulation in the multilayered graphene medium is governed by an intercalation process of non-volatile ionic liquids under a voltage bias. The electrically driven reduction of emissivity lowers the apparent temperature of a surface, aligning it with the background temperature to achieve thermal camouflage. This characteristic is shared by other graphene-based materials. In this review, we focus on recent advancements in the thermal camouflage properties of graphene in composite films and aerogel structures. We provide a summary of the current understanding of how thermal camouflage materials work, their present limitations, and future opportunities for development
Assessing genotoxic effects of plastic leachates in Drosophila melanogaster
Get PDFPlastic polymers were largely added with chemical substances to be utilized in the items and product manufacturing. The leachability of these substances is a matter of concern given the wide amount of plastic waste, particularly in terrestrial environments, where soil represents a sink for these novel contaminants and a possible pathway of human health risk. In this study, we integrated genetic, molecular, and behavioral approaches to comparatively evaluate toxicological effects of plastic leachates, virgin and oxodegradable polypropylene (PP) and polyethylene (PE), in Drosophila melanogaster, a novel in vivo model organism for environmental monitoring studies and (eco)toxicological research. The results of this study revealed that while conventional toxicological endpoints such as developmental times and longevity remain largely unaffected, exposure to plastic leachates induces chromosomal abnormalities and transposable element (TE) activation in neural tissues. The combined effects of DNA damage and TE mobilization contribute to genome instability and increase the likelihood of LOH events, thus potentiating tumor growth and metastatic behavior ofRasV12 clones. Collectively, these findings indicate that plastic leachates exert genotoxic effects in Drosophila thus highlighting potential risks associated with leachate-related plastic pollution and their implications for ecosystems and human health