Parameterization of physical properties of layered body structure into equivalent circuit model

Background This study presents a novel technique to develop an equivalent circuit model (ECM) for analyzing the responses of the layered body structure to transcutaneous electrical nerve stimulation (TENS) by parameterizing electrical and geometrical properties.Many classical ECMs are non-parametric because of the difficulty in projecting intrapersonal variability in the physical properties into ECM. However, not considering the intrapersonal variability hampers patient-specifically analyzing the body response to TENS and personal optimization of TENS parameter design. To overcome this limitation, we propose a tissue property-based (TPB) approach for the direct parameterization of the physical properties in the layered body structure and thus enable to quantify the effects of intrapersonal variability. Results The proposed method was first validated through in vitro phantom studies and then was applied in-vivo to analyze the TENS on the forearm. The TPB-ECM calculated the impedance network in the forearm and corresponding responses to TENS. In addition, the modelled impedance was in good agreement with well-known impedance properties that have been achieved empirically. Conclusions The TPB approach uses the parameterized circuit components compared to non-parametric conventional ECMs, thus overcoming the intrapersonal variability problem of the conventional ECMs. Therefore, the TPB-ECM has a potential for widely-applicable TENS analysis and could provide impactful guidance in the TENS parameter design.

Uranium-Lead Geochronology of Two-Feldspar Granites of the Inhul Megablock (Ukrainian Shield) by Monazite

In the area of the Novooleksandrivka village, the valley of the Bokovenka river crosses a powerful strip of metamorphic rocks of the Inhulo-Inhulets series with numerous small granitoid bodies of the Kirovohrad complex. In the right bank of the river valley north of Novooleksandrivka there are almost continuous rock outcrops of porphyry-like, mostly coarse-grained garnet-biotite granites, which are cut by veins of aplite-pegmatoid and pegmatoid granites. Uranium-lead isotope systems of accessory monazites from porphyry-like granite, layered body of uneven-grained granite and from veined body of aplite-pegmatoid granite have been studied. The age of the first two, more coarse-grained granite varieties, is 2043.2 ± 2.6 and 2041 ± 2.3 million years, respectively. Significantly younger are the monocytes from the vein of aplite-pegmatoid granite - 2030 ± 0.3 million years. In granites in this sequence, in addition to structural and textural characteristics (in general, decrease in grain size), there is a decrease in the amount of SiO2 (from 73.14 to 70.93%) connected with a significant increase in K2O (from 3.96 to 7.58%), (their inverse correlation coefficient is 0.98), a significant decrease in the CaO content from 2.04 to 0.97%, and a slight decrease in the MgO content from 1.14% to 0.82%. These changes are probably caused by the crystallizational differentiation of the original granite melt.

Parameterization of physical properties of layered body structure into equivalent circuit model

BackgroundThis study presents a novel technique to develop an equivalent circuit model (ECM) for analyzing the responses of the layered body structure to transcutaneous electrical nerve stimulation (TENS) by parameterizing electrical and geometrical properties. Many classical ECMs use custom meta-parameters instead of the physically driven parameters because of the difficulty in projecting physical properties directly into ECM. However, the difference in what parameters are customized hampers general agreement in modeling the responses to TENS. To overcome this limitation, we propose a tissue property-based (TPB) approach for the direct parameterization of the layered body structure.ResultsThe proposed method was first validated through in vitro phantom studies and then was applied in-vivo to analyze the TENS on the forearm. The TPB-ECM calculated the impedance network in the forearm and corresponding the responses to TENS. In addition, the modeled impedance was in good agreement with well-known impedance properties that have been achieved empirically.ConclusionsThe TPB approach uses the physical parameters instead of meta-parameters, thus overcoming the disagreement problem of conventional ECMs. Therefore, the TPB-ECM has a potential for widely-applicable TENS analysis and could provide impactful guidance in the TENS parameter design.

Numerical Analysis of Elastic Contact between Coated Bodies

Substrate protection by means of a hard coating is an efficient way of extending the service life of various mechanical, electrical, or biomedical elements. The assessment of stresses induced in a layered body under contact load may advance the understanding of the mechanisms underlying coating performance and improve the design of coated systems. The iterative derivation of contact area and contact tractions requires repeated displacement evaluation; therefore the robustness of a contact solver relies on the efficiency of the algorithm for displacement calculation. The fast Fourier transform coupled with the discrete convolution theorem has been widely used in the contact modelling of homogenous bodies, as an efficient computational tool for the rapid evaluation of convolution products that appear in displacements and stresses calculation. The extension of this technique to layered solids is tantalizing given that the closed-form analytical functions describing the response of layered solids to load are only available in the frequency domain. Whereas the false problem periodization can be treated as in the case of homogenous solids, the aliasing phenomenon and the handling of the frequency response function in origin require adapted techniques. The proposed algorithm for displacement calculation is coupled with a state-of-the-art contact solver based on the conjugate gradient method. The predictions of the newly advanced computer program are validated against existing results derived by a different method. Multiple contact cases are simulated aiming to assess the influence of coating thickness and of its elastic properties on the contact parameters and the strass state. The performed simulations prove that the advanced algorithm is an efficient tool for the contact analysis of coated bodies, which can be used to further understand the mechanical behavior of the coated system and to optimize its design.

Indentation of rigid rough surface into polymer coating layer

An analysis of engineering approaches to determining the value of the introduction of spherical asperity and a rough surface into the polymer layer is given. It is shown that engineering methods of solving contact problems on the basis of simplifying hypotheses are more practical, for example, the representation of a layered body as a construction with special mechanical properties that depend on the mechanical properties of base and coating materials and the thickness of the coating. Analysis of the use of the proposed engineering solutions in calculating the value of the indentation of the sphere showed the advantages of the method based on the rigid model of a layered body. In this case, the effective modulus of elasticity and the Poisson's ratio are determined for any values of the coating thickness for an axisymmetric loading of a layered half-space. To determine the value of the indentation of a rough surface into the polymer layer, a discrete model of a rough surface is used. When contacting a rough surface through a polymer layer, it was taken into account that each asperity corresponds to a certain modulus of elasticity, which is determined by the level of the peak and the value of approach.

“Sun in the Belly”: Film Practice at Films Division of India 1965–1975

This article looks at one decade (1965–1975) in the history of Films Division of India (FD), the first state film production and distribution unit in the country. It tracks the changing political environment and several administrative, infrastructural, and policy changes of the time, along with the emerging “experimental” film and interview format films. Under the dynamic supervision of Jean Bhownagary, a constellation of film makers and artists like Pramod Pati, S.N.S. Sastry, S. Sukhdev, among others came to the fore, experiment with film form was encouraged, and dissonant voices rose against the state itself. I suggest that it is possible to study certain experiments and formal practices emerging at a particular time and space not as mere aberrations, but as something that emerges from complex shifts in institutional practice. I locate these as part of a layered body of film uses, a palimpsest, in which the filmmaker’s creative engagement needs to be situated in a bureaucratic order that could be arbitrary and inflexible but also provide for a regime of the permissible.

Determination of the Elastic Characteristics of Bodies with Thin Coatings

We Consider a Layered Elastic Body, Consisting of Base Material with Young's Modulus E0 and Poisson's Ratio ν0 and Coating Thickness δ, Respectively, with E1 и ν1. the Thickness of the Base Is much Greater than the Thickness of the Coating. A Stiffness Model of the Layered Body with Loading His Axisymmetric Load, which Allows to Determine its Elastic Characteristics Is Proposed. the Quantitative Effect of the Relative Thickness of the Coating, the Ratio of the Elastic Properties of the Materials and Forms of the Applied Load Is Shown. an Expression for Determining the Elastic Modulus of the Coating when the Effective Modulus of Elasticity of the Layered Body Indentation Determined by the Method of Oliver-Farr Is Got. the Thickness of a Covering and Elastic Constants of the Main Material and Intentor Are Thus Considered.

Gravitational field of the homogeneous rotational ellipsoidal body: a simple derivation and applications

Gravitational field of the homogeneous rotational ellipsoidal body: a simple derivation and applications We calculate the gravitational intensity and potential of a homogeneous body with the shape of the rotational ellipsoid. The calculation is performed in ellipsoidal coordinates and uses the properties of harmonic functions expressed as ellipsoidal harmonics. The resulting formulae for the internal and external fields are expressed in ellipsoidal coordinates and (in the case of external field) also in spherical coordinates. The results are used in the calculation of the gravitational field of a layered body whose layer boundaries are rotational ellipsoids with common centre and rotational axis; the density in each layer is constant. The equilibrium of such a layered rotating body is examined: it is found that there is no equilibrium for such a body except the case that the body is homogeneous (thus proving once more the important, but rarely mentioned, fact).