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To study the magnetic shielding of buried high‐voltage (HV) cables by adding conductive metal plates on the ground surface above the cables.

The field is calculated with eight rectangular conductive plates above the cables, positioned with their long edge either parallel to the cables or transversal to the cables. Here, the circuit method is used. In this method, the shield is replaced by a grid of straight filaments in which the unknown currents are searched by solving an electrical circuit.

It is observed from the calculation results that it is important to have a perfect electrical connection between adjacent plates. In the area above the shield, an “infinite” contact resistance between neighbouring plates results roughly in double field amplitude compared to the situation with contact resistance zero. The positioning of the rectangular plates (parallel or transversal to the cables) has not much influence on the shielding. The shielding efficiency as a function of the shield size is studied as well. The circuit method is validated by measurements on an experimental setup at reduced scale.

The circuit method is applied to conductive objects and not to ferromagnetic objects.

As the circuit method is rather fast also for 3D geometries with thin plates, the shielding of HV cables can be evaluated in a computationally more efficient way than by using, e.g. finite elements.

The circuit method is already described in the literature. The originality of this paper is the study – by this circuit method – of the effect of several parameters (size of the shield, contact resistance, orientation of the plates) on the shielding efficiency.

Shielding of electromagnetic low frequency field can be performed by means of conductive sheets. These sheets have a thickness which is usually two or three orders of magnitude lower than their other dimensions, thus their effects must be modeled by means of special numerical techniques. In this paper, two integral formulations for the analysis of conductive shields are presented: one is two‐dimensional and is based on a multiconductor system, while the other, three‐dimensional, is based on a finite formulation of electromagnetic fields. Once these analysis tools have been introduced, this paper presents the study of different shielding systems and a problem of optimal exploitation of conductive material.

This paper describes a boundary element analysis of magnetic shieldings for electron microscopes. Since the thickness of the shielding layer is considerably small compared with its overall size, numerical analysis of electromagnetic fields inside the layer leads to an ill‐conditioned matrix. This problem can be overcome by analytical evaluation of the interior electromagnetic field, which yields the impedance boundary condition (IBC) valid for static and eddy current fields, which expresses the relationship between the electromagnetic fields on both surfaces of the layer. In this paper the magnetic fields around a shielding layer are analyzed by the boundary element method under the IBC on the shielding layer. Two‐dimensional and axisymmetric magnetic fields are analyzed to evaluate the shielding efficiency of shielding immersed in an ac magnetic field. It is shown that magnetic disturbances can be reduced to less than one‐hundredth inside a shielding consisting of double shielding layers.

This study aims to design and validate a theoretical model for capacitive imaging (CI) sensors that incorporates the interelectrode shielding and surrounding shielding electrodes. Through experimental verification, the effectiveness of the theoretical model in evaluating CI sensors equipped with shielding electrodes has been demonstrated.

The study begins by incorporating the interelectrode shielding and surrounding shielding electrodes of CI sensors into the theoretical model. A method for deriving the semianalytical model is proposed, using the renormalization group method and physical model. Based on random geometric parameters of CI sensors, capacitance values are calculated using both simulation models and theoretical models. Three different types of CI sensors with varying geometric parameters are designed and manufactured for experimental testing.

The study’s results indicate that the errors of the semianalytical model for the CI sensor are predominantly below 5%, with all errors falling below 10%. This suggests that the semianalytical model, derived using the renormalization group method, effectively evaluates CI sensors equipped with shielding electrodes. The experimental results demonstrate the efficacy of the theoretical model in accurately predicting the capacitance values of the CI sensors.

The theoretical model of CI sensors is described by incorporating the interelectrode shielding and surrounding shielding electrodes into the model. This comprehensive approach allows for a more accurate evaluation of the detecting capability of CI sensors, as well as optimization of their performance.

The shield tunnels closely constructed near the foundations have an inevitable influence on the structures, even results in the large settlement or uplift of the structures.

The comparison of structural deformation of three different foundations is presented based on the field monitoring data.

Shield tunnelling parameters vary for the different types of foundations. For the long pile foundations, the recommended speed is 3 to 4 cm/min, the grouting pressure is about 0.3 MPa and the grouting rate ranges from 150 to 180.

The study based on the field monitoring data is rarely reported, especially the topic about the structural deformation of different types of the foundations.

The purpose of this paper is to investigate the way in which CEOs are shielded or rewarded for incurring R&D expenses. Strategic expenses such as R&D yield returns over a long period of time even though GAAP requires them to be written off in the period they are incurred. Going beyond the existing shielding paradigm, the paper investigates whether compensation committees actively reward CEOs for incurring strategic expenses.

The paper uses empirical analysis by using regression analysis with CEO compensation (both cash and equity) as the dependent variable and firm size, firm performance, earnings risk, market‐to‐book ratio, R&D expenses, advertising expenses and governance variables as control, independent and test variables.

The paper shows that CEOs are not only shielded but are actively rewarded for incurring R&D expenses. The paper also shows that the shield/reward effects are stronger in manufacturing firms. Finally, the paper shows that independent compensation committees increase rewards for R&D expenses.

Given the small sample of firms with advertising expense data, a larger sample, possibly using hand‐collected data will be required to arrive at definitive conclusions regarding shielding/rewarding for advertising. Furthermore, the shielding of both R&D and advertising expenses should be looked at in conjunction with the duration of the persistence of benefits of such strategic expenses.

This paper shows how compensation committees can use compensation to induce executives to undertake strategic expenses on behalf of the firm.

With the popularization of electronic products, the electromagnetic radiation pollution has been the fourth largest pollution after water, air and noise pollution. Therefore, electromagnetic shielding property of textiles is attracting more attention. In this paper, the properties of electromagnetic shielding yarns and fabrics were studied.

Ten kinds of yarn, stainless steel short fiber and polyester blend yarn with three different blending ratios T/S 90/10, T/S 80/20 and T/S 70/30, stainless steel short fiber, polyester and cotton blend yarn with blending ratio C/T/S 35/35/30, core-spun yarn with one 30 um stainless steel filament C/T28tex/S(30 um), core-spun yarn with two 15 um stainless steel filaments (C/T28tex/S(15 um)/S(15 um)), twin-core-spun yarn with one 30 um stainless steel filament and one 50D spandex filament C/T28tex/S(30 um)/SP(50D), sirofil wrapped yarn with one 30 um stainless steel filament feeding from left S(30 um)+C/T28tex, sirofil wrapped yarn with one 30 um stainless steel filament feeding from right C/T28tex+S(30 um), sirofil wrapped yarn with two 15 um stainless steel filaments feeding from two sides S(15 um)+C/T28tex+ S(15 um), were spun. The qualities of spun yarns were measured. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven.

The tested results show that comparing to the T/S 80/20 blend yarn, the resistivity of composite yarns with the same ratio of the stainless steel filament is smaller. The possible reason is that comparing to the stainless steel short fiber, the conductivity of stainless steel filament is better because of the continuous distribution of stainless steel in the filament. Comparing with the core-spun yarn, the conductivity of the sirofil wrapped yarn is a little better. Comparing to the fabric woven by the blend yarn, the electromagnetic shielding of the fabric woven by the composite yarn is better, and comparing to the fabric woven by the core-spun yarn, the electromagnetic shielding of the fabric woven by the sirofil yarn is a little better. The possible reason is that the conduction network can be produced by the stainless steel filament wrapped on the staple fiber yarn surface in the fabric, and the electromagnetic wave can be transmitted in the network.

In this paper, the properties of electromagnetic shielding yarns and fabrics were studied. Ten kinds of yarn, including three stainless steel short fiber and polyester blend yarns, one stainless steel short fiber, polyester and cotton blend yarn, two core-spun yarns, one twin-core-spun yarn, three sirofil wrapped yarn, were spun. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven. The effects of fabric warp and weft densities, fabric structures, yarn kinds, yarn distributions in the fabric on electromagnetic shielding were analyzed.

The purpose of this paper is to show that distinguishing between gross and net tax shields arising from interest deductions is important to firm valuation. The distinction affects the interpretation but not valuation of tax shields for the famous Miller’s (1977) model with corporate and personal taxes. However, for the well-known Miles and Ezzell’s (1985) model, the authors show that the valuation of tax shields can be materially affected. Implications to the cost of equity and optimal capital structure are discussed.

This paper proposed a simple tax shield clarification that distinguishes between gross and net tax shields. Net tax shields equal gross tax shields minus personal taxes on debt. When an after-tax riskless rate is used to discount shareholders’ tax shields, this distinction affects the interpretation but not valuation results of the Miller’s model. However, when the after-tax unlevered equity rate is used to discount tax shields under the well-known Miles and Ezzell’s (1985) model, the difference between gross and net tax shields can materially affect valuation results. According to the traditional ME model, both gross tax shields and debt interest tax payments (i.e. net tax shields) are discounted at the after-tax unlevered equity rate. By contrast, the proposed revised ME model discounts gross tax shields at the unlevered equity rate but personal taxes on debt income at the riskless rate (like debt payments). Because personal taxes on debt are nontrivial, traditional ME valuation results can noticeably differ from the revised ME model to the extent that after-tax unlevered equity and debt rates differ from one another.

For comparative purposes, the authors provide numerical examples of the traditional and revised ME models. The following constant tax rates and market discount rates are assumed: T_c=0.30, T_pb=0.20, T_ps=0.10, r=0.06, and ρ=0.10. Table I compares these two models’ valuation results. Maximum firm value for the traditional ME model is 7.89 compared to 7.00 for the revised ME model. At a 50 percent leverage ratio, equity value is reduced from 3.71 to 3.49, respectively. Importantly, the traditional ME model suggests that firm value linearly increases with leverage and implies an all-debt capital structure, whereas firm value stays relatively constant as leverage increases in the revised ME model. These capital structure differences arise due to discounting debt tax payments with the unlevered equity rate (riskless rate) in the traditional ME (revised ME) model. Figure 1 graphically summarizes these results by comparing the traditional ME model (thin lines) to the revised ME model (bold lines).

Textbook treatments of leverage gains to firms or projects with corporate and personal taxes should be amended to take into account this previously unrecognized tradeoff. Also, empirical analyses of capital structure are recommended on the sensitivity of leverage ratios to the gross-tax-gain/debt-personal taxes tradeoff.

Financial managers need to understand how to value interest tax shields on debt in making capital structure decisions, computing the cost of capital, and valuing the firm.

The valuation of interest tax shields in finance is a long-standing controversy. Nobel prize winners Modigliani and Miller (MM) wrote numerous papers on this subject and gained fame from their ideas in this area. However, application of their ideas has changed over time due to the Miles and Ezzell’s (ME) model of firm valuation. The present paper adapts the pathbreaking ideas of MM to the valuation framework of ME. Students and practitioners in finance can benefit by the valuation results in the paper.

No previous studies have recognized the valuation issues resolved in the paper on the application of the popular and contemporary ME model of firm valuation to the MM valuation concepts. The new arguments in the paper are easy to understand and readily applied to firm valuation.

This paper aims to deal with the problem of vibration in an aircraft engine turbine shaft shield. The physical model of the system under study is inspired by the PZL-10W aviation jet engine shaft shield and is a structure of the profile circular arc. The main goal of the presented research is to develop a modal model of the discussed object. Another task is to determine the impact of the shaft shield damage on the change of dynamic parameters (the values of the natural frequencies and changing of the shape of the corresponding natural forms) of the discussed object. Finally, the task is connected with the calculation of the excitation speeds of the discussed shaft shield’s respective natural frequencies.

To realize the main goal finite element method simulation and experimental investigation were conducted. The quality of the achieved models is determined based on the relative error of natural frequencies and the similarity to normal modes established on the basis of the modal assurance criterion (MAC) indicator. The Campbell diagram was used to calculate the excitation speeds of the discussed shaft shield’s respective natural frequencies.

The obtained results indicate the changes in the dynamic properties of the shaft shield as a result of its cracking. On the basis of the adopted measurement (MAC indicator), the level of similarity was established between the numerical simulation results and the measurement results for the undamaged shield. Verification of the different mode shapes using the CrossMAC tool is an effective method, which allows comparing of the shape of the natural form and may be helpful in the process of adjusting modal models to the results of experimental tests.

It is important to note that as a result of using commercial software (ANSYS program) and a commercial measuring system (Bruel and Kjaer), the presented analysis can be attractive for design engineers dealing with the dynamics of aviation systems.

The paper presents the authors’ original approach to the dynamic analysis of the aviation engine turbine shaft shield, which can be useful for engineers dealing with the issue of vibration in shaft shield systems.

The purpose of this paper is to propose an efficient numerical simulation tool based on FEM, by which the EMC shielding effect characteristics of power cables can be predicted in the 30-1,000 MHz frequency range, as if it would be measured by the absorbing clamp method.

The simulation method is based on decomposition: a 2D axisymmetric RF FE model is used for describing the whole measurement set-up, while a 3D quasi-static FE model is used for the symmetry cell of the shielding layer in order to capture the effect of its fine geometric details.

Comparison with real measurements shows that the shielding characteristics can be reliably predicted this way, with some deviation in the low end of the frequency range though.

This simulation tool can be applied in the design and optimization of braided cable shields to be used in the automotive industry.

Two numerical models are coupled by the novel concept of “equivalent shielding layer”, which is obtained by homogenization.