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This paper aims to introduce an alternative for modeling levitation forces between NdFeB magnets and bulks of high-temperature superconductors (HTS). The presented approach should be evaluated through two different formulations and compared with experimental results.

The T-A and H-ϕ formulations are among the most efficient approaches for modeling superconducting materials. COMSOL Multiphysics was used to apply them to magnetic levitation models and predict the forces involved.The permanent magnet movement is modeled by combining moving meshes and magnetic field identity pairs in both 2D and 3D studies.

It is shown that it is possible to use the homogenization technique for the T-A formulation in 3D models combined with mixed formulation boundaries and moving meshes to simulate the whole device’s geometry.

The case studies are limited to the formulations’ implementation and a brief assessment regarding degrees of freedom. The intent is to make the simulation straightforward rather than establish a benchmark.

The H-ϕ formulation considers the HTS bulk domain as isotropic, whereas the T-A formulation homogenization approach treats it as anisotropic. The originality of the paper lies in contrasting these different modeling approaches while incorporating the external magnetic field movement by means of the Lagrangian–Eulerian method.

We test the pertinence of the unemployment invariance hypothesis (UIH) for a set of Organisation for Economic Co-operation and Development countries.

We empirically investigate the nexus between unemployment and labour force participation employing structural vector autoregressive methods for panel data.

We find that shocks in unemployment produce long-lasting, negative effects on participation, testifying to a discouraged worker effect.

Our results do not support the validity of the UIH in high-income economies. This has relevant implications for policy making and macroeconomic models.

This study aims to evaluate the failure behavior of glass fiber-reinforced epoxy (GFRE) laminate subjected to cyclic loading conditions. It involves experimental investigation and statistical analysis using Weibull distribution to characterize the failure behavior of the GFRE composite laminate.

Fatigue tests were conducted using a tension–tension loading scheme at a frequency of 2 Hz and a loading ratio (R) of 0.1. The tests were performed at five different stress levels, corresponding to 50%–90% of the ultimate tensile strength (UTS). Failure behavior was assessed through cyclic stress-strain hysteresis plots, dynamic modulus behavior and scanning electron microscopy (SEM) analysis of fracture surfaces.

The study identified common modes of failure, including fiber pullouts, fiber breakage and matrix cracking. At low stress levels, fiber breakage, matrix cracking and fiber pullouts occurred due to high shear stresses at the fiber–matrix interface. Conversely, at high stress levels, fiber breakage and matrix cracking predominated. Higher stress levels led to larger stress-strain hysteresis loops, indicating increased energy dissipation during cyclic loading. High stress levels were associated with a more significant decrease in stiffness over time, implying a shorter fatigue life, while lower stress levels resulted in a gradual decline in stiffness, leading to extended fatigue life.

This study makes a valuable contribution to understanding fatigue behavior under tension–tension loading conditions, coupled with an in-depth analysis of the failure mechanism in GFRE composite laminate at different stress levels. The fatigue behavior is scrutinized through stress-strain hysteresis plots and dynamic modulus versus normalized cycles plots. Furthermore, the characterization of the failure mechanism is enhanced by using SEM imaging of fractured specimens. The Weibull distribution approach is used to obtain a reliable estimate of fatigue life.

The consolidation process and morphology evolution in ceramics-based additive manufacturing (AM) are still not well-understood. As a way to better understand the ceramic selective laser sintering (SLS), a dynamic three-dimensional computational model was developed to forecast thermal behavior of hydroxyapatite (HA) bioceramic.

AM has revolutionized automotive, biomedical and aerospace industries, among many others. AM provides design and geometric freedom, rapid product customization and manufacturing flexibility through its layer-by-layer technique. However, a very limited number of materials are printable because of rapid melting and solidification hysteresis. Melting-solidification dynamics in powder bed fusion are usually correlated with welding, often ignoring the intrinsic properties of the laser irradiation; unsurprisingly, the printable materials are mostly the well-known weldable materials.

The consolidation mechanism of HA was identified during its processing in a ceramic SLS device, then the effect of the laser energy density was studied to see how it affects the processing window. Premature sintering and sintering regimes were revealed and elaborated in detail. The full consolidation beyond sintering was also revealed along with its interaction to baseplate.

These findings provide important insight into the consolidation mechanism of HA ceramics, which will be the cornerstone for extending the range of materials in laser powder bed fusion of ceramics.

This paper aims to investigate the problem of estimating the angle of attack (AoA) and relative velocity for vertical axis wind turbine (VAWT) blades from computational fluid dynamics data.

Two methods are implemented as function objects within the OpenFOAM framework for estimating the blade’s AoA and relative velocity. For the numerical analysis of the flow around and through the VAWT, 2 D unsteady Reynolds-averaged Navier–Stokes (URANS) simulations are carried out and validated against experimental data.

To gain a better understanding of the complex flow features encountered by VAWT blades, the determination of the AoA is crucial. Relying on the geometrically-derived AoA may lead to wrong conclusions about blade aerodynamics.

This study can lead to the development of more robust optimization techniques for enhancing the variable-pitch control mechanism of VAWT blades and improving low-order models based on the blade element momentum theory.

Assessment of the reliability of AoA and relative velocity estimation methods for VAWT’ blades at low-Reynolds numbers using URANS turbulence models in the context of dynamic stall and blade–vortex interactions.

The purpose of this paper is to evaluate if, given personal, supply-related features, and labour demand-related variables, there is a difference in the share of women finding more stable jobs with respect to men, in an eight-year time span.

Fragmentation leads to a lower probability of transitioning into more certain, full-time work positions. The authors analyse a rich cohort of dependent workers in Emilia-Romagna to investigate whether part-time jobs lead to full-time jobs in a “stepping-stone” fashion and whether this happens with the same probability for men and women. The focus is on the cost of part-time jobs rather than the contrast between permanent and temporary jobs, as often observed in the literature. The authors also evaluate the transition between part-time job formulae and open-ended work arrangements to determine whether women's transition to full-fledged, stable work positions is slightly rarer than their male counterparts. Even if the authors allow for the fact that part-time contracts can be a choice and not an obligation, these contracts generate more flexibility in managing the equilibrium between private and work life and create more uncertainty than full-time contracts because of the fragmentation associated with these arrangements.

The authors find that women have a more fragmented working career than men, in that they hold more contracts than men in the same time span; moreover, the authors find that part-time jobs act more as bottlenecks for women than for men.

The authors use a large administrative dataset with over 600,000 workers observed in the 2008–2015 time span, in Emilia Romagna, Italy. The authors can disentangle the number of contracts per worker and observe individual, anonymise personal features, that the authors consider in the authors' propensity score estimate. The authors ran a robustness check of the PSM estimates through coarsened exact matching (CEM).

The purpose of this paper is to introduce a novel cross (+) type yoke with hybrid electromagnets and new reluctance modeling to precisely calculate attraction force is given.

The comparison of attraction force and torque analyses between the proposed formulation and the existing formulation in the literature is comparatively presented. For the correctness of the force and torque values calculated in the model created, the system was created in ANSYS Maxwell and its accuracy was proved by making analyses. The maglev carrier system is inherently unstable from the point of view of control engineering. For that, it needs an active controller to eliminate this instability. For the levitation of the carrier system, it is necessary to design a controller in three axes (z, α and β). I-PD controller was designed for the air gap control of the carrier system in three axes and the controller parameters were determined by the canonical method.

While the new formulation proposed in the modeling of the carrier system has a maximum error of 1.03%, the existing formula in the literature has an error of 16.83% in the levitation distance point.

A novel cross-type hybrid carrier system has been proposed in the literature. With the double integral used in modeling the system, it takes a long time to solve symbolically, and it is difficult to simulate dynamic behavior in control validation. To solve this problem, attraction force and inclination torque values are easily characterized by new formulation and besides the simulations are conducted easily. The experimental setup was manufactured and assembled, and the carrier system was successfully levitated, and reference tracking was performed without overshoot.

Crime increased in Spain during the period of 2017–2019 after a decade of decline. This coincides with severe housing deprivation multiplying by three in just four years, affecting 3.4% of the population in 2020. However, no research has been found that analyzes whether this deterioration of the physical conditions of housing and its environmental elements has impacted the level of crime in Spain. This study aims to analyze how housing deprivation affects crime in the Spanish context.

For this purpose, different items that are considered by Eurostat as elements of housing deprivation are used. The difference generalized method of moments estimator is used for 16 Spanish regions that comprises the period from 2013 to 2019.

The results suggest that certain structural and environmental elements of housing are positively associated with crime: space (0.5% and 0.4%) and high housing expenditure (0.4% and 0.5%) are positively correlated with the two dependent variables; the lack of light and overcrowding stand out as they establish a positive and statistically significant association with four out of the six analyzed crime categories; the absence of lighting effect reaches up to 1.8% and 1.7% in the case of violent robberies and vehicle theft, respectively. Finally, pollution is negatively associated with robbery with violence (−1.9%), theft (−0.7%) and robbery with force (−0.5%).

To the best of the author’s knowledge, this is the first study that examines whether this deterioration of the physical conditions of housing has impacted the level of crime in Spain. It is also pioneering at the European level by using nonmonetary dimensions of inequality such as housing.

There are few reports that evolutional topology optimization methods are applied to the conductor geometry design problems. This paper aims to propose an evolutional topology optimization method is applied to the conductor design problems of an on-chip inductor model.

This paper presents a topology optimization method for conductor shape designs. This method is based on the normalized Gaussian network-based evolutional on/off topology optimization method and the covariance matrix adaptation evolution strategy. As a target device, an on-chip planer inductor is used, and single- and multi-objective optimization problems are defined. These optimization problems are solved by the proposed method.

Through the single- and multi-objective optimizations of the on-chip inductor, it is shown that the conductor shapes of the inductor can be optimized based on the proposed methods.

The proposed topology optimization method is applicable to the conductor design problems in that the connectivity of the shapes is strongly required.

The main objective of this research is to exploratorily analyse different factors that influence the decision of the senior population (+50 years) to engage in entrepreneurship activities in a group of Latin American countries. This study considers the motivations for entrepreneurship (opportunity and necessity) and the level of development of the countries.

The authors used data from the Global Entrepreneurship Monitor (GEM) with a sample of 22,139 observations of senior individuals in seven Latin American countries surveyed between 2013 and 2017. The authors also used the Human Development Index to capture the relevance of the level of development. The authors employed a multilevel logistic regression model to test the study hypotheses.

The study results show that individual factors such as personal income, education and occupation have a significant influence on the probability of entrepreneurship of senior individuals. Related to contextual factors, the level of human development of a country has a negative influence mainly on opportunity-based entrepreneurs.

Because of the rapidly ageing population in Latin America, understanding senior entrepreneurs and their motivations is very relevant not only in terms of theoretical development but also for policy and practical implications, primarily those related to labour markets and social protection.