Простая теория многокомпонентной диффузии и моделирование горения стехиометрической смеси H-=SUB=-2-=/SUB=-/O-=SUB=-2-=/SUB=-

A theory of multicomponent diffusion based on Fick's law is proposed, where, when writing the Maxwell-Stephen equations, a multicomponent mixture is represented as consisting of two components: the isolated substance and all the others with average characteristics. The number of diffusion coefficients is significantly reduced, the method for their calculation is indicated, and they strongly depend on the concentration of the mixture components. Based on the results of this theory, the combustion of an H2/O2 mixture with an equivalence ratio equal to unity was simulated. For each component, great chemical work is carried out with alternating signs, but in total they partially destroy each other. Also, in the chemical reaction zone, there is a strong change in the stoichiometric ratio of the H2 and O2 components.

Numerical Study of the Unsteady Aerodynamic Performance of Two Maglev Trains Passing Each Other in Open Air Using Different Turbulence Models

The strong change in the flow fields around two maglev trains (MTs) passing each other in open air may affect their manoeuvrability and passengers’ comfort. In this study, we evaluated the aerodynamic performance of two MTs passing each other via shear stress transport (SST) k–ω model and improved delayed detached eddy simulations based on the Spalart–Allmaras model (SA−IDDES) and the SST k–ω model (SST−IDDES). The accuracy of the numerical simulation method was verified using experimental data acquired from a moving model test. The results showed that the difference in the amplitude of the transient pressure obtained with the different turbulence models was less than 5%. The wake vortex structures on the intersection side were found to interact, and their intensity consequently decreased. The SST−IDDES model produced smaller-scale vortices than the SA−IDDES model, particularly in the near-wake region. There were large differences in the drag and lift forces obtained using the different turbulence models. Among them, the lift force of the tail car was more sensitive to the turbulence model, and its maximum value obtained with the SST−IDDES model was 11% larger than that obtained with the SA−IDDES model.

Phase transition in the bipartite z-matching

We study numerically the maximum z-matching problems on ensembles of bipartite random graphs. The z-matching problems describes the matching between two types of nodes, users and servers, where each server may serve up to z users at the same time. Using a mapping to standard maximum-cardinality matching, and because for the latter there exists a polynomial-time exact algorithm, we can study large system sizes of up to $$10^6$$ 10 6 nodes. We measure the capacity and the energy of the resulting optimum matchings. First, we confirm previous analytical results for bipartite regular graphs. Next, we study the finite-size behaviour of the matching capacity and find the same scaling behaviour as before for standard matching, which indicates the universality of the problem. Finally, we investigate for bipartite Erdős–Rényi random graphs the saturability as a function of the average degree, i.e. whether the network allows as many customers as possible to be served, i.e. exploiting the servers in an optimal way. We find phase transitions between unsaturable and saturable phases. These coincide with a strong change of the running time of the exact matching algorithm, as well with the point where a minimum-degree heuristic algorithm starts to fail. Graphical Abstract

Multiple Criteria Decision-Making as an Operational Conceptualization of Energy Sustainability

There is a broad international consensus about the urgency of promoting a strong change towards energy models that are less dependent on non-renewable energy sources, more equitable, and truly environmentally friendly. In order to achieve this goal, we need to define the problem so that it can be operationally and comprehensively addressed. This paper presents a proposal of a framework for the analysis of the sustainability of energy models based on multiple criteria theory, which we consider comprehensive and operational enough. Its application to a real energy model, the Spanish one, shows that the framework is able to address most of the elements both of weak and strong sustainability and find a reasonable compromise within the limits of the problem.

Goldilocks Effect of Base Strength on Site Selectivity in Acylation of Amphiphilic Diols

Two series of competitive acylation experiments with a polar and an apolar alcohol substrates, imitating two parts of amphiphilic diols, examined the influence of bases of varying strength on the substrate selectivity. While weakly basic 2,4,6-collidine only mildly accelerates the acylation of the polar substrate without affecting that of the apolar one, the acylation of both substrates is drastically hastened by strongly basic DBU. In both cases there is a notable, though not overwhelming, shift of the substrate selectivity towards the polar substrate, compared to the base-free acylation, which strongly favors that of the apolar one. The extraordinarily strong change in the substrate selectivity in favor of the polar substrate was induced, however, by aliphatic tertiary amine bases, DIPEA and TEA, of “Goldilocks” moderate base strength, which strongly accelerate the acylation of the polar substrate, while almost not affecting that of the apolar one. These effects of the bases on the substrate selectivity are reflected in the site selectivity trends observed in the acylation of a model diol amphiphile.

Lähijohtajien muutosvalmius kuntasektorilla

Recent studies have highlighted the importance of managers’ role in change. Managers are a lynchpin in the success of a change as they stand closest to employees and they are both implementing change but also being affected by change. In this study, we explore managers´ readiness of change. Readiness of change refers to what employees perceive as the balance between costs and benefits of maintaining a behavior. In practice, it is about psychological willingness to cooperate in bringing the change to fruition. We interviewed 19 managers in public sector organizations. The findings indicate that strong change readiness of managers requires organizational support, time resources for people management and participative organizational culture. Study highlights the individual experience and interpretation of meaningfulness of change. This can be achieved by communicating the consequences and benefits of change clearly and by engaging managers in change already in the early phase.

Smile through the Mask: Emotion Measurement for Stationary Retail

The global pandemic caused by the coronavirus disease (COVID-19) changes the lives of many people all over the world. In the context of stationary retail, a strong change of customer behavior occurs as mandatory safety measures like wearing facemasks and distance regulations have come into place. The sales personnel’s ability to understand and react to customers’ emotions is critical for service interactions and the customers’ overall satisfaction. Unfortunately, facemasks make it difficult to recognize other’s emotions and may lead to misinterpretation and confusion. To address this problem, this paper proposes the design of self-assessment interfaces that offer the customer an easy way to enter their emotions. As part of a Design Science Research (DSR) project, we designed three interfaces and evaluated them over the course of a design cycle. The results indicate that it is possible to use self-assessment technology in stationary retail to measure customer emotions.

EFFECT OF THE USE OF STROBILURINE-BASED FUNGICIDES ON THE QUALITY OF SPRING SOFT WHEAT GRAIN

The effect of fungicide class strobilurine on "effect gardening" plants is undeniable. Most research on this class of drugs focuses on their effects on plant growth and physiology. There is little information about the effect of strobilurine on the rheological properties of the dough when applied to wheat. In our work, we tried to identify their role. The objects of the study were 5 varieties of spring soft wheat, with different grain and flour quality. To study the effect strobilurins was selected fungicide containing pyraclostrobin + epoxiconazole. The use of a preparation based on pyraclostrobin does not lead to a strong change in the grain quality and rheological properties of the dough in rust-resistant varieties, this indicates that strobilurins almost do not affect the grain quality. In varieties that are highly and medium susceptible to leaf-stem diseases, not only the yield increases significantly, but also the grain quality and rheological properties of the test improve when using a fungicide based on pyraclostrobin 62.5 g/l + epoxiconazole 62.5 g/l at a dose of 1.5 l/ha.

Sensitivity of Altimeter Wave Height Assessment to Data Selection

This paper addresses the issue of how the selection of buoys and the calculation of altimeter averages affect the metrics characterising the errors of altimetric wave height estimates. The use of a 51-point median reduces the sensitivity to occasional outliers, but the quality of this measure can be improved by demanding that there is a minimum number of valid measurements. This had a marked impact in both the open ocean and the coastal zone. It also affected the relative ordering of algorithms’ performances, as some fared poorly when a representative value was gleaned from a single waveform inversion, but had a much better ranking when a minimum of 20 values were used. Validation procedures could also be improved by choosing altimeter-buoy pairings that showed a good consistency. This paper demonstrated an innovative procedure using the median of the different retrackers analysed, which can be easily extended to other data validation exercises. This led to improved comparison statistics for all algorithms in the open ocean, with many showing errors less than 0.2 m, but there was only one strong change in the relative performance of the 11 Jason-3 retrackers. For Sentinel-3A, removing the inconsistent coastal buoys showed that all of the new algorithms had similar errors of just over 0.2 m. Thus, although improvements were found in the procedure used for the Sea State Round Robin exercise, the relative rankings for the buoy calibrations are mostly unaffected.

Using Optical Activation to Create Hydrogen and Hydrogen-Containing Gas Sensors

It was found that at room temperature the value of the photoinduced current of Schottky diodes based on heterostructures InP/GaInAs/Pd at a hydrogen concentration of 0.03% is reduced by two orders of magnitude compared to the value without hydrogen. The value of the photoinduced current depends on the thickness of the depleted region on the surface of the semiconductor. A small change in the charged layer of H+ can cause a significant change in the thickness of this region and as a result, a strong change in the photoinduced current. This effect on current is much stronger than the influence of hydrogen concentration or capacitance without optical activation. As a result, it becomes possible to create hydrogen and hydrogen-containing gas sensors with much better sensitivity at room temperature. The original design of a miniature H2 sensor including an IR LED, a Schottky diode with a Pd contact, a Peltier cooler and a thermosensor is demonstrated.