Abstract The confinement of energetic particles (EPs) generated by fusion reactions and external heating methods is crucial for the performance of future fusion devices. However, EP transport can ...occur due to their interaction with electromagnetic perturbations, affecting heating efficiency and overall performance. Robust reduced models are needed to analyze stability and transport. This paper presents an automated IMAS-based workflow for analyzing the time-dependent stability of EP-driven modes, focusing on the linear properties of Toroidal Alfvén Eigenmodes (TAEs) in general tokamak geometry. The workflow utilizes efficient computational methods and reduced models to deliver fast and reproducible results. A demonstration of the workflow’s effectiveness was performed, identifying key linear properties of TAEs in various simulated ITER scenarios. This approach represents a critical step toward developing tools for analyzing EP transport and optimizing the performance of future fusion reactors.
Abstract In this paper we report on the implementation and verification of a phase-space resolved energetic particle (EP) transport model. It is based on a first-principle theoretical framework, i.e. ...the system of non-linear gyrokinetic equations and the related transport equations. Its focus is primarily directed toward understanding the meso-scale character of EPs and its consequences. Compared to the conventional description of thermal radial transport via a one-dimensional radial diffusion equation, the newly developed model is three-dimensional using canonical constants-of-motion (CoM) variables. The model does not assume diffusive processes to be dominant a priori , instead the EP fluxes are self-consistently calculated and directly evolved in CoM space. We use the EP-Stability workflow and the HAGIS code to determine the phase space fluxes explicitly either in the limit of constant mode amplitudes or an energy-conserving quasi-linear model. As an application of the model the transport of neutral-beam-generated EPs due to a toroidal Alfvén eigenmode in an ITER plasma is investigated. As there are no sources and collisions taken into account so far (for an extension of the model see the companion paper (Meng et al 2024 Nucl. Fusion accepted)), the results cannot be considered as an exhaustive study, but rather as a practical demonstration of the conceptual framework on the way to a comprehensive reduced description of burning plasmas.
Oleandrin, the main component of
L. extracts, is a cardiotoxic glycoside with multiple pharmacological implications, having potential anti-tumoral and antiviral characteristics. Although it is ...accepted that the main mechanism of oleandrin action is the inhibition of Na
/K
-ATPases and subsequent increase in cell calcium, many aspects which determine oleandrin cytotoxicity remain elusive. In this study, we used the model
to unravel new elements accounting for oleandrin toxicity. Using cells expressing the Ca
-sensitive photoprotein aequorin, we found that oleandrin exposure resulted in Ca
influx into the cytosol and that failing to pump Ca
from the cytosol to the vacuole increased oleandrin toxicity. We also found that oleandrin exposure induced Mn
accumulation by yeast cells via the plasma membrane Smf1 and that mutants with defects in Mn
homeostasis are oleandrin-hypersensitive. Our data suggest that combining oleandrin with agents which alter Ca
or Mn
uptake may be a way of controlling oleandrin toxicity.
Technical installations can account for up to half of the building costs and it is crucial to have detailed projects for the assembly and maintenance of these systems. This means that workflow can be ...improved more efficiently and faster. With the help of the installation engineer, the beneficiary can track and control the correct execution of the works. The installation engineer is the link between the beneficiary and the contractor or those who deliver the materials and equipment, people who generally follow works and additional sales. As regards the design of technical installations, the development of versatile low-response software interfaces becomes necessary and appropriate. The article is focused on the interface that has been developed as a software instrument to increase design process productivity and optimization of technical installations by reducing the required work time and the number of clicks made. Inside the application, the Revit design software was used and the number of clicks needed to access the element linking and node troubleshooting of the technical installations was reduced. Two new functionalities have been created within the software application: "connect and copy" and "connect and rotate".
One of the most important aspects of the detection of antioxidant compounds is developing a fast screening method. The screening of the overall relative antioxidant capacity (RAC) of several Romanian ...hydrosoluble plant extracts is the focus of this work. This is important because of the presence of increasing levels of reactive oxygen species (such as H₂O₂) generates oxidative stress in the human body. The consequences are a large number of medical conditions that can be helped by a larger consumption of plant extracts as food supplements, which do not necessarily contain the specified antioxidant contents. By exploiting the catalytic properties of gold nanoparticles, a specific and sensitive nanoparticle-based label-free electrochemical sensor was developed, where the working parameters were optimized for RAC screening of hydrosoluble plant extracts. First, electrochemical measurements (cyclic voltammetry and amperometry) were used to characterize different nanoparticle-based sensors, revealing the best performance of gold nanoparticle-based sensors, obtaining a RAC of 98% for lavender extracts. The sensing principle is based on the quenching effect of antioxidants for H₂O₂ amperometric detection, where the decrease in electrical signal suggests an increasing antioxidant capacity. The obtained results were expressed in terms of ascorbic acid and Trolox equivalents in order to be able to correlate our results with classical methods like chemiluminescence and UV-Vis spectrophotometry, where a correlation coefficient of 0.907 was achieved, suggesting a good correlation between electrochemistry and spectrophotometry. Considering these results, the optimized gold nanoparticle-based label-free sensor can be used as a simple, rapid alternative towards classical methods for relative antioxidant capacity detection of hydrosoluble plant extracts.
The self-organizing properties of nematic liquid crystals can be used to align carbon nanotubes dispersed in them. Because the nanotubes are so much thinner than the elastic penetration length, the ...alignment is caused by the coupling of the unperturbed director field to the anisotropic interfacial tension of the nanotubes in the nematic host fluid. In order to relate the degree of alignment of the nanotubes to the properties of the nematic liquid crystal, we treat the two components on the same footing and combine Landau−de Gennes free energies for the thermotropic ordering of the liquid crystal and for the lyotropic nematic ordering of carbon nanotubes caused by their mutually excluded volumes. The phase ordering of the binary mixture is analyzed as a function of the volume fraction of the carbon nanotubes, the strength of the coupling and the temperature. We find that the degree of ordering of the nanorods is enslaved by the properties of the host liquid and that it can be tuned by raising or lowering the temperature or by increasing or decreasing their concentration. By comparing the theory to recent experiments, we find the anchoring energy of multiwalled carbon nanotubes to be in the range from 10-10 to 10-7 N m-1.
We consider the flow of marine-terminating outlet glaciers that are laterally confined in a channel of prescribed width. In that case, the drag exerted by the channel side walls on a floating ice ...shelf can reduce extensional stress at the grounding line. If ice flux through the grounding line increases with both ice thickness and extensional stress, then a longer shelf can reduce ice flux by decreasing extensional stress. Consequently, calving has an effect on flux through the grounding line by regulating the length of the shelf. In the absence of a shelf, it plays a similar role by controlling the above-flotation height of the calving cliff. Using two calving laws, one due to Nick et al. (2010) based on a model for crevasse propagation due to hydrofracture and the other simply asserting that calving occurs where the glacier ice becomes afloat, we pose and analyse a flowline model for a marine-terminating glacier by two methods: direct numerical solution and matched asymptotic expansions. The latter leads to a boundary layer formulation that predicts flux through the grounding line as a function of depth to bedrock, channel width, basal drag coefficient, and a calving parameter. By contrast with unbuttressed marine ice sheets, we find that flux can decrease with increasing depth to bedrock at the grounding line, reversing the usual stability criterion for steady grounding line location. Stable steady states can then have grounding lines located on retrograde slopes. We show how this anomalous behaviour relates to the strength of lateral versus basal drag on the grounded portion of the glacier and to the specifics of the calving law used.
This paper presents an intelligent methodology for diagnosing incipient defects of rotating machines and is focused on monitoring the vibrations of an asynchronous motor. Monitoring of industrial ...plant operation parameters requires the acquisition of many electrical and non-electric parameters, parameters that can be monitored with powerful software. The technical state of operation of an industrial machine can be judged based on the symptoms it exhibits during operation, in our case the vibrations. Vibration analysis that occurs during engine operation may indicate electrical defects, such as broken rotor blades, unbalanced stator circuits, eccentric rotors and stators, loose power connections. There are mechanical defects and electrical faults in the vibration spectrum. A web application has been created to facilitate the interpretation of the linear spectrum resulting from the vibration monitoring of an asynchronous motor and to be accessible to any user. There was developed an application with Microsoft Silverlight, a software platform that allows us to display advanced multimedia content from a web browser. The spectrum reproduced by the application is simple, precisely to be accessible to everyone and to know very easily whether the machine is working correctly or not.
The article addresses the design of an automation system for the lamination process of the cars, which has as inputs different types of transducers, and as outputs the command of a linear pneumatic ...motor. The layered and self-supporting laminated structures of motor vehicles are manufactured from a thermoplastic substrate and a flexible sheet material in one direction rolling and cutting operation. The installation for producing these laminates is a casting press having two casting plates, each of which comprises a component of a pair of cutting means. It is used a CPU 315-2 PN / DP, which is a medium-sized program memory processor and it is often used in automation structures. This processor can also be used as distributed intelligence (master or slave). The implementation of the code sequence to work on this processor is done in one of the specific languages to the programmable machines. The software used in programming is STEP 7. The stored information is not erased when the processor is disconnected. The usefulness of programmable machines has simplified the approach of an automated system.
An experimental investigation was performed to study the heat transfer performance of a 36 nm-Al2O3-particle-water nanofluid in a confined and submerged impinging jet on a flat, horizontal and ...circular heated surface. The tests were realized for the following ranges of the governing parameters: the nozzle diameter is 3 mm and the distance nozzle-to-heated-surface was set to 2, 5 and 10 mm; the flow Reynolds number varies from 3800 to 88 000, the Prandtl number from 5 to 10, and the particle volume fraction is ranging from 0 to 6%. Experimental data, obtained for both laminar and turbulent flow regimes, have clearly shown that, depending upon the combination of nozzle-to-heated surface distance and particle volume fraction, the use of a nanofluid can provide a heat transfer enhancement in some cases; conversely, for other combinations, an adverse effect on the convective heat transfer coefficient may occur. Within the experimental parameters used, it has been observed that highest surface heat transfer coefficients can be achieved using an intermediate nozzle-to-surface distance of 5 mm and a 2.8% particle volume fraction nanofluid. Nanofluids with high particle volume fractions, say 6% or higher, have been found not appropriate for the heat transfer enhancement purpose under the confined impinging jet configuration. On the other hand, for a very small and a large distance of nozzle-to-heated-surface, it has been observed that the nanofluid use does not provide a perceptible heat transfer enhancement and has, for some particular cases, produced a clear decrease of the convective heat transfer coefficient while compared to that obtained using distilled water.
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