Practical application of natural convective heat exchange of electrical equipment with air

This paper provides the physical and mathematical model of the air flow in a volume, containing electrical equipment with the heat-generating and heat-absorbing surfaces. The model predicts the temperature fields and air flow velocities across the volume. Using the developed model, we calculate the values of heat fluxes in the vicinity of the thermostated electrical equipment for three different cases: natural convective, forced and mixed modes of the airflow. The possibility of beneficial use of natural convective air flows for the transfer of thermal energy is analyzed. The results are applied in an industrial enterprise. Energy consumption for ventilation is significantly reduced.

Mixed Modes and Asteroseismic Surface Effects. II. Subgiant Systematics

Models of solar-like oscillators yield acoustic modes at different frequencies than would be seen in actual stars possessing identical interior structure, due to modeling error near the surface. This asteroseismic “surface term” must be corrected when mode frequencies are used to infer stellar structure. Subgiants exhibit oscillations of mixed acoustic (p-mode) and gravity (g-mode) character, which defy description by the traditional p-mode asymptotic relation. Since nonparametric diagnostics of the surface term rely on this description, they cannot be applied to subgiants directly. In Paper I, we generalized such nonparametric methods to mixed modes, and showed that traditional surface-term corrections only account for mixed-mode coupling to, at best, first order in a perturbative expansion. Here, we apply those results, modeling subgiants using asteroseismic data. We demonstrate that, for grid-based inference of subgiant properties using individual mode frequencies, neglecting higher-order effects of mode coupling in the surface term results in significant systematic differences in the inferred stellar masses, and measurable systematics in other fundamental properties. While these systematics are smaller than those resulting from other choices of model construction, they persist for both parametric and nonparametric formulations of the surface term. This suggests that mode coupling should be fully accounted for when correcting for the surface term in seismic modeling with mixed modes, irrespective of the choice of correction used. The inferred properties of subgiants, in particular masses and ages, also depend on the choice of surface-term correction, in a different manner from those of both main-sequence and red giant stars.

ВЛИЯНИЕ МИРОВЫХ ПАНДЕМИЙ НА ФОРМИРОВАНИЕ МЕТОДОВ ТРУДОВОЙ АДАПТАЦИИ В РАМКАХ КАДРОВОГО МЕНЕДЖМЕНТА

The article discusses topical issues of the implementation of adaptation measures within the constraints associated with modern global trends. Epidemics and a massive transition to a remote mode of operation, as well as the introduction of mixed modes in view of the continuing danger, served as a reason for analyzing existing adaptation measures and checking them for compliance with modern trends in personnel management. The article discusses a number of popular methods of including an employee in a new social and labor environment. The possibility of finalizing and improving the existing measures for their more correct application under modern conditions is considered.

Studies of Radial and Thickness Acoustic Resonance Modes of a Piezoceramic with Mixed Polarization Geometry

In this study, the Pb(Zr0.65Ti0.35)O3 (PZT) structure was produced by the solid state reaction method, and a new polarization geometry was used to obtain the radial and thickness modes in cylindrical samples with more efficiency. The polarization procedure was investigated by varying the temperature from 30°C to 80°C. The experimental excitation of radial and thickness modes was observed, and a comparative study was performed with numerical simulations. The comparative analysis of the acoustic response of the cylindrical PZT samples under theoretical and experimental conditions was validated by COMSOL Multiphysics® software. The new polarization geometry technique was used to generate radial thickness and acoustic mixed modes with more efficiency. The results show that the resonance frequency and antiresonance, as well as the impedance mode and phase angle are well adjusted, showing the validation of the technique presented between the theoretical and experimental measurements.

Probing core overshooting using subgiant asteroseismology: The case of KIC10273246

Context. The size of convective cores remains uncertain, despite their substantial influence on stellar evolution, and thus on stellar ages. The seismic modeling of young subgiants can be used to obtain indirect constraints on the core structure during main sequence, thanks to the high probing potential of mixed modes. Aims. We selected the young subgiant KIC10273246, observed by Kepler, based on its mixed-mode properties. We thoroughly modeled this star, with the aim of placing constraints on the size of its main-sequence convective core. A corollary goal of this study is to elaborate a modeling technique that is suitable for subgiants and can later be applied to a larger number of targets. Methods. We first extracted the parameters of the oscillation modes of the star using the full Kepler data set. To overcome the challenges posed by the seismic modeling of subgiants, we propose a method that is specifically tailored to subgiants with mixed modes and uses nested optimization. We then applied this method to perform a detailed seismic modeling of KIC10273246. Results. We obtain models that show good statistical agreements with the observations, both seismic and non-seismic. We show that including core overshooting in the models significantly improves the quality of the seismic fit, optimal models being found for αov = 0.15. Higher amounts of core overshooting strongly worsen the agreement with the observations and are thus firmly ruled out. We also find that having access to two g-dominated mixed modes in young subgiants allows us to place stronger constraints on the gradient of molecular weight in the core and on the central density. Conclusions. This study confirms the high potential of young subgiants with mixed modes to investigate the size of main-sequence convective cores. It paves the way for a more general study including the subgiants observed with Kepler, TESS, and eventually PLATO.

No magic bullet: estimating anti-immigrant sentiment and social desirability bias with the item-count technique

Extant scholarship on attitudes toward immigration and immigrants relies mostly on direct survey items. Thus, little is known about the scope of social desirability bias, and even less about its covariates. In this paper, we use probability-based mixed-modes panel data collected in the Southern Spanish region of Andalusia to estimate anti-immigrant sentiment with both the item-count technique, also known as list experiment, and a direct question. Based on these measures, we gauge the size of social desirability bias, compute predictor models for both estimators of anti-immigrant sentiment, and pinpoint covariates of bias. For most respondent profiles, the item-count technique produces higher estimates of anti-immigrant sentiment than the direct question, suggesting that self-presentational concerns are far more ubiquitous than previously assumed. However, we also find evidence that among people keen to position themselves as all-out xenophiles, social desirability pressures persist in the list-experiment: the full scope of anti-immigrant sentiment remains elusive even in non-obtrusive measurement.