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The purpose of this paper is to propose an approach, which is easy to implement, for estimating the thickness of the air layer that may separate metallic parts in some aeronautical assemblies, by using the eddy current method.

Based on an experimental study of the coupling of a magnetic cup core coil sensor with a metallic layered structure (consisting of first metal layer/air layer/second metal layer), which is confirmed by finite element modelling simulations, an inversion technique relying on a polynomial forward model of the coupling is proposed to estimate the air layer thickness. The least squares and the nonnegative least squares algorithms are applied and analysed to obtain the estimation results.

The choice of an appropriate inversion technique to optimize the estimation results is dependent on the signal-to-noise ratio of measured data. The obtained estimation error is smaller than a few percent, for both simulated and experimental data. The proposed approach can be used to estimate both the air layer thickness and the second metal layer thickness simultaneously/separately.

This model-based approach is easy to implement and available to all types of eddy current sensors.

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

The paper aims to present the advanced mathematical and numerical models of conjugated heat and mass transfer in a multi-layer protective clothing, human skin and muscle subjected to incident external radiative heat flux.

The garment was made of three layers of porous fabric separated by the air gaps, whereas in the tissue, four skin sublayers and muscle layer were distinguished. The mathematical model accounted for the coupled heat transfer by conduction and thermal radiation with the associated phase transition of the bound water in the fabric fibres and diffusion of the water vapour in the clothing layers and air gaps. The skin and muscle were modelled with two equation model which accounted for heat transfer in the tissue and arterial blood. Complex thermal and mass transfer conditions at the internal or external boundaries between the fabric layers, air gaps and skin were assumed. Special attention was paid to modelling of thermal radiation emitted by external heat source, for example, a fire, penetrating through the protective clothing and being absorbed by the skin and muscle.

Temporal and spatial variations of temperature in the protective garment, skin and muscle, as well as volume fractions of the water vapour and bound water in the clothing, were calculated for various intensity of incident radiative heat flux. The results of numerical simulation were used to estimate the risk of the first-, second- and third-degree burns.

Because of the small thickness of the considered system in comparison to its lateral dimensions, the presented model was limited to 1D heat and moisture transfer. The convective heat transfer through the clothing was neglected.

The model may be applied for design of the new protective clothing and for assessment of thermal performance of the various types of protective garments. Additionally, the proposed approach may be used in the medicine for estimation of degree of thermal destruction of the tissue during treatment of burns.

The novel advanced thermal model of the multi-layer protective garment, skin and muscle layer was developed. For the first time, non-grey optical properties and various optical phenomena at the internal or external boundaries between the fabric layers, air gaps and skin were accounted for during simulation of thermal interactions between the external heat source (e.g. a fire), protective clothing and human skin.

The purpose of this paper is to develop a system for estimating the position of the active magnetic bearing (AMB) shaft. A new approach using the static and dynamic inductances and complex analytic signal to simplify the estimation procedure. Finite element (FE) simulations are introduced as a part of the system synthesis.

The paper presents an AMB displacement estimation system. The system is created with three inductive sensors. The position is computed from refined static and dynamic inductance obtained from complex analytic signals of flux and current. FE simulation is used to relate refined inductances to the displacement and to verify the model.

This paper shows the applicability of complex analytic signal transformation on estimation systems. The use of new refined inductance is presented in contrast to the classical approach of static and dynamic inductances. The paper shows that classical approach of static and dynamic inductance is not usable for the presented estimation system.

For the practical implementation of the presented system, it is necessary to know the exact dimensions of the AMB stator and the voltage and frequency used to supply the inductance estimation system.

The paper presents a system for estimating the displacement of AMB. The paper introduces the application of complex analytic signal to the estimation of AMB displacement. The mentioned signal is used to compute the new refined inductances. The comparison to the classical approach of static and dynamic inductances is given in this paper. The paper introduces FE simulations to the estimation system synthesis.

The purpose of this paper is to report on a study which has been carried out on a timber floor construction above a ground‐supported concrete slab, which was used in small detached houses built in Sweden during the period 1960‐1990. This method of building has turned out to be a risky construction nowadays, but there are 800,000 houses built this way in Sweden.

By using the patented Air Gap Method inside building constructions, harmful water can be dried out. The method ventilates air gaps inside walls and floors with an air flow driven by thermal buoyancy caused by a heating cable in the vertical air gaps. The drying out process has been studied both by measuring the moisture level in the slab and also by measuring the humidity transport and comparing this with air flow measurements.

The paper shows that the Air Gap Method manages to dry out water from both the slab and the overlaying wooden construction. The study shows also that the relative humidity (RH) levels in the air space below the floor are reduced in a significant way, thus minimizing mould growth. It is also shown that a thin layer of concrete upon floor beams prevents mould to grow even in a humid situation.

The research reported in this paper is only concerned with timber‐framed small detached houses. Similar studies of apartment buildings are ongoing.

The Air Gap Method can thus be useful in the context of renovating a water damaged house of this type built during this 30‐year period. The method provides a possibility of drying out such damage without a separate drying period. The inhabitants could therefore be able to use a renovated water‐damaged kitchen six/eight weeks earlier compared to ordinary building methods.

The paper is useful because it provides better understanding of the mechanism of RH inside a building construction and how this parameter could be lowered. The paper is also useful in the context of renovating water‐damaged small detached houses built by the risky method of construction used in the last decades of the twentieth century.

This chapter investigates the effects of economic development, FDI, trade barriers, product characteristics, and air transport network connectivity on both air trade and air cargo demand. The analysis applies gravity model and estimates the air trade and air cargo demand models using seemingly unrelated regressions based on data for the air cargo markets between the United States and its top 61 trading partner countries during the 2004–2019 period. By developing and incorporating “investment distance” as a determining factor in the estimation of air trade, our study fills the gap in literature and sheds light on the importance of air cargo transport in enabling and facilitating the rapid growth of global value chains in recent decades. The results suggest that higher level of FDI between the US and its trading partner countries helps stimulate air trade. Moreover, we also develop several network centrality metrics and examine their relationship with regional air connectivity, which in turn has a positive impact on air cargo traffic. Further analysis using Granger causality tests provides strong evidence supporting the importance of air cargo services as an engine for economic growth and international trade in a dynamic global economic landscape.

The thermal design of high‐speed electrical machines is a greater challenge in comparison with conventional electrical machines. When designing the machine, the calculated temperatures in all parts should be lower than their critical temperatures. This paper aims to perform thermal analysis for different rotor types according to the level of shield from eddy currents in order to achieve a safe thermal design of the machine.

The machine under study in the paper is a high‐speed permanent magnet (PM) motor designed for speed n=31,500 rpm and power P=130 kW. A thermal‐network method was used for thermal analysis of the machine.

The minimum value of the coolant flow in the air gap that provides an effective cooling of the machine was estimated. The coolant itself is not able to provide an effective cooling of the magnets if they are not shielded from eddy currents.

The results are obtained only by the thermal‐network method. Numerical techniques and practical measurements for comparison and validation of the existing results should be implemented in future.

The paper offers useful practical information when a safe thermal design of a high‐speed PM electrical machine should be performed.

The paper demonstrates how three different design types of a high‐speed PM electrical machine are thermally analysed in order to find out which type fulfils the rigorous thermal criteria. The practical significance of the paper is beneficial for the designers of high‐speed PM electrical machines.

The purpose of this paper is to provide a new computational method based on the polynomial chaos (PC) expansion to identify the uncertain parameters of load sensing proportional valve (LSPV), which is commonly used to improve the efficiency of brake system in heavy truck.

For this investigation, the mathematic model of LSPV is constructed in the form of state space equation. Then the estimation process is implemented relying on the experimental measurements. With the coefficients of the PC expansion obtained by the numerical implementation, the output observation function can be transformed into a linear and time-invariant form. The uncertain parameter recursively update functions based on Newton method can therefore be derived fit for computer calculation. To improve the estimation accuracy and stability, the Newton method is modified by employing the acceptance probability to escape from the local minima during the estimation process.

The accuracy and effectiveness of the proposed parameter estimation method are confirmed by model validation compared with other estimation methods. Meanwhile, the influence of measurement noise on the robustness of the estimation methods is taken into consideration, and it is shown that the estimation approach developed in this paper could achieve impressive stability without compromising the convergence speed and accuracy too much.

The model of LSPV is originally developed in this paper, and then the authors propose a novel effective strategy for recursively estimating uncertain parameters of complicate pneumatic system based on the PC theory.

This study aims to calculate eddy current losses in permanent magnets of BLDC machine in the generator mode of operation with no‐load.

Stator slot openings and special design of the stator poles cause changes in the magnetic flux density changes in permanent magnets. The stator windings are not connected to an outer source and no currents flow in them. The induced eddy currents in permanent magnets are dependent solely on the stator geometry. Analytical approach to calculate the eddy current density distribution in permanent magnets is based on known distribution of magnetic flux density in the air‐gap of BLDC. The magnetic flux density distribution is obtained from magneto‐static finite element model of BLDC. For verification of analytical approach the eddy current density distribution in permanent magnets is also calculated by magneto‐transient finite element model of BLDC.

The eddy current losses in PM obtained with the FEM indicate additional heating of the BLDC machine at high rotational speeds even when it operates at no load. When some special stator designs (the side of the air gap) are needed, the losses in PMs and their heating increase.

To get more precise results, the proposed analytical method for eddy current losses calculation in PM should be further analyzed. More geometric parameters of the BLDC design should be introduced to analytical formulations, especially those which affect variations in reluctance.

When some special stator designs (the side of the air gap) are needed, the losses in PMs should be observed. This is particularly recommended at higher rotation velocities. Any kind of magnetic flux density change induces eddy currents and together with them also power losses. These losses give rise to additional heating of PM. With this, the temperature‐dependent working characteristic of PM (second quadrant of the B‐H curve) moves toward the coordinate origin point. The overall machine performance is reduced. The presented work gives the view about happenings in permanent magnets regarding induced eddy current losses. It is a useful tool for fast estimation and reduction of eddy current losses in PM due to stator geometry.

The value of the paper is the closed view about happenings in permanent magnets regarding induced eddy currents and the calculation of eddy current losses in rotor permanent magnets of BLDC due to stator design. The originality is in the analytical approach to calculate the eddy current losses based only on known magneto‐static flux density distribution in air‐gap of BLDC.

The aim of this paper is to introduce an accurate asymmetric fault index for the diagnosis of the faulty linear permanent magnet Vernier machine (LPMVM).

Three-dimensional finite element method is applied to model the LPMVM. The geometrical and physical properties of the machine, the effect of stator and translator teeth, magnetic saturation of core and nonuniform air gap due to asymmetric fault are taken into account in the simulation. The air gap asymmetric fault is proposed. This analytical method estimates the air gap flux density of an LPMVM.

This paper presents an analytical method to predict the performance of a healthy and faulty LPMVM. The introduced index is based on the frequency patterns of the stator current. Besides, the robustness of the index in different loads and fault severity is addressed.

Introducing index for air gap asymmetry fault diagnosis of LPMVM.