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Stochastic electromagnetic fields coupling to printed circuit board (PCB) traces are important to the understanding of electromagnetic compatibility at high frequencies when the circuits or systems are electrically large. In this article, it is studied both numerically and analytically, and the factors affecting the absorbed power are investigated. We present new methods to determine the level of coupling on PCB traces or other transmission lines on a dielectric substrate. A Monte Carlo method is applied to generate random uniform fields, and the quasi-TEM transmission line model is employed to compute the response of the trace for each plane wave numerically. In the analytical method, the closed-form expressions of the zero-order and the first-order approximations are established for the PCB trace. Based on the first-order approximation method and the numerical results, a computationally efficient empirical method is developed to estimate the power received. The absorbed power increases with frequency in the electrically short case after which multiple resonances can be seen. The absorbed power in the matched case is neither the largest nor the smallest among all the cases. It increases with the square of the substrate height but decreases with the permittivity of the substrate.

The human body absorption cross section (ACS) is important in nonionizing radiation dosimetry, but it is always hard to accurately evaluate the ACS of an individual from his or her morphological parameters, such as height and weight. To obtain an empirical formula that can evaluate the ACS from morphological parameters, 48 subjects with different morphological parameters were measured from 1 to 16 GHz in a reverberation chamber. The ACS was extracted from the power delay profile. This has the advantage of not requiring antenna radiation efficiency, and it has not been previously used in a wideband group study like this. The accuracy of the ACS measurement is demonstrated by comparison with the ACS of a spherical model with known structure and material, and the mean absolute percentage error of the sphere measurement is just 3.4%. Statistical analysis shows that the body surface area (BSA) has the strongest correlation with the ACS among all the morphological parameters; therefore, we present a new empirical ACS formula as a function of BSA and frequency. This will be of interest to those considering dosimetry, and in computing the effect of human body absorption on radio propagation in vehicles and other structures.

In this work, we consider the nonlinear Schrödinger equation (NLSE) in $2+1$ dimensions with arbitrary nonlinearity exponent $κ$ in the presence of an external confining potential. Exact solutions to the system are constructed, and their stability over their "mass" (i.e., the $L^2$ norm) and the parameter $κ$ is explored. We observe both theoretically and numerically that the presence of the confining potential leads to wider domains of stability over the parameter space compared to the unconfined case. Our analysis suggests the existence of a stable regime of solutions for all $κ$ as long as their mass is less than a critical value $M^{\ast}(κ)$. Furthermore, we find that there are two different critical masses, one corresponding to width perturbations and the other one to translational perturbations. The results of Derrick's theorem are also obtained by studying the small amplitude regime of a four-parameter collective coordinate (4CC) approximation. A numerical stability analysis of the NLSE shows that the instability curve $M^{\ast}(κ)$ vs. $κ$ lies below the two curves found by Derrick's theorem and the 4CC approximation. In the absence of the external potential, $κ=1$ demarcates the separation between the blowup regime and the stable regime. In this 4CC approximation, for $κ, 24 pages, 8 figures

This paper describes a detailed test setup and procedure to characterize the robustness of Wi-Fi3 and Bluetooth 4.2 against continuous wave electromagnetic disturbances inside a reverberation chamber. Bluetooth 4.2 robustness was also characterized by continuous broadband noise. These experiments aim to reveal the susceptibility of commonly used wireless communication protocols against continuous wave noise. Results show that Wi-Fi3 has an abrupt rise in the packet error rate (up to ≈ 100%) when the continuous wave noise overlaps with the Wi-Fi3 working frequency. Bluetooth 4.2 is robust against continuous wave noise, thanks to the frequency hopping technique, but fails against broadband noise. ispartof: pages:1031-1038 ispartof: The 2021 IEEE International Joint EMC/SI/PI and EMC Europe Symposium proceedings pages:1031-1038 ispartof: 2021 JOINT IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, SIGNAL & POWER INTEGRITY, EMC EUROPE location:Glasgow, the UK date:26 Jul - 20 Aug 2021 status: published

A resonant dipole antenna for testing immunity of equipment to intentional electromagnetic interference (IEMI) is described, along with simulated and measured test results which are in good agreement and demonstrate the high voltage operation.

Interference analysis and prediction in integrated circuits (ICs) is of significant interest to the Electromagnetic Compatibility (EMC) community. In this paper, an easy method is introduced to estimate the level of RF interference coupled into ICs through the package. Although IC packages are in different forms with large number of pins, the presented analysis method provides a general solution and greatly shortens the computation time by creating a simplified model with consideration of the cross coupling between pins. The expected voltage range at the outer ends and inner ends of the pins are also investigated for resistive loads. The levels of energy coupled into PCB traces and packages are also compared for immunity analysis.

A robust lightweight antenna for testing immunity of equipment to intentional electromagnetic interference (IEMI), based on a planar Vivaldi design, is described, along with simulated and measured test results.

This paper shows that the Shielding Effectiveness of a printed circuit board shield (PCBS) varies depending on the shield’s external environment when the circuit board level shield is installed within a larger external enclosure. A reverberation chamber based technique is demonstrated that allows the underlying Shielding Effectiveness of the circuit board level shield to be evaluated along with an estimate of its expected variability due to the external enclosure.

Hypertrophic cardiomyopathy is a commonly occurring cardiovascular disease resulting primarily from changes in proteins participating in muscle contraction in the heart, including the cardiac actin protein. Changes in cardiac actin located exclusively in the myosin binding site are called M-class variants and include the H88Y, R95C, and E99K substitutions and F90Δ deletion. The prevailing hypothesis for these mutations is that hypertrophic cardiomyopathy is the result of increased calcium sensitivity of contraction in the myocardium. To test this hypothesis, we studied the activity of myosin at varying calcium concentrations in the presence of regulated thin filaments containing M-class cardiac actin variants. We found that all M-class cardiac actin variants exhibit increased calcium sensitivity, with the R95C variant also displaying significant decreases in maximal myosin activity. This work represents the first characterization of all M-class variant proteins and suggests that drugs targeting contraction specifically to treat hypertrophic cardiomyopathy must consider the impact on both calcium sensitivity and maximal myosin activity on overall heart health.

The power balance technique for the prediction of shielding effectiveness of reverberant enclosures is fast and simple to use. However, it assumes a uniform field in the enclosure, which has been shown to be incorrect in the presence of dissipative contents. The diffusion model is a generalization of the power balance method that can account for the field inhomogeneity due to the presence of losses with much lower computational effort than a full-wave solver. Evaluation of a two-dimensional diffusion model produced promising results compared to physical measurements. Here, we present a three-dimensional (3-D) diffusion model applied to an enclosure with an aperture and dissipative contents. Comparisons between the 3-D diffusion model, measurements, and a full-wave solver suggest that it is able to account for the variation of the electromagnetic field due to dissipative contents with far less computational effort than full-wave solvers. The diffusion model allows rapid solution of the shielding effectiveness of enclosures with dissipative contents and arbitrary geometries and reduces the time to model equipment enclosures from hours to minutes, while still determining the variation of field strength due to contents. In addition, the method may help predict field inhomogeneity in reverberation chambers.

A purified F-actin-derived actin trimer that interacts with end-binding proteins did not activate or bind the side-binding protein myosin under rigor conditions. Remodeling of the actin trimer by the binding of gelsolin did not rescue myosin binding, nor did the use of different means of inhibiting the polymerization of the trimer. Our results demonstrate that ADP-ribosylation on all actin subunits of an F-actin-derived trimer inhibits myosin binding and that the binding of DNase-I to the pointed end subunits of a crosslinked trimer also remodels the myosin binding site. Taken together, this work highlights the need for a careful balance between modification of actin subunits and maintaining protein–protein interactions to produce a physiologically relevant short F-actin complex.

Research on the use of blogs in higher education suggests that students who blog as part of a course requirement demonstrate increased reflection, heightened feelings of connection, and increased course-related knowledge. Blogging provides a promising medium for students to engage in reflection on their participation in a cooperative education work term. Blogging can help guide a project by providing an encouraging place for team members to communicate clearly, document their work and other resources, and brainstorm ideas. In this paper, we describe a qualitative analysis of blog posts written by three students during a co-op placement. The students used the blog extensively and with multiple purposes: to reflect, to communicate, to brainstorm ideas, to evaluate literature, and to document team creations. We discuss the characteristics of the project and blog that may have contributed to its extensive use and provide recommendations for individuals interested in implementing a blog in similar projects., Selon la recherche, les étudiants en enseignement supérieur utilisant un blogue pour satisfaire aux exigences des cours montrent un niveau élevé de réflexion, de sentiment d’appartenance et de connaissances liées au cours. Le blogage fournit aux étudiants un médium prometteur pour s’engager dans la réflexion durant un stage coopératif. Le blogue peut guider un groupe en encourageant une communication claire, une documentation des ressources et un libre partage des idées. Dans ce document, nous décrivons une analyse qualitative des articles de blogue de trois étudiants en stage. Les étudiants ont largement utilisé le blogue : pour communiquer, pour faire des « remue-méninges, » pour évaluer la littérature et pour documenter des créations communes. Nous discutons les caractéristiques du projet qui pourraient avoir eu un impact sur l’utilisation répandue du blogue, avant de proposer des conseils à ceux qui s’intéressent à la mise en œuvre du blogage dans de tels projets.

The primary contribution of this paper lies in evaluating the throughput performance of a wireless sensor network (WSN) with realistic directional antennas. A simple medium access control (MAC) protocol is proposed, based on the Slotted Aloha protocol but designed to support multiple directional antennas at the hub. A brief review of the throughput analysis for the traditional Aloha protocols is given, followed by an analytical model for the throughput performance for directional hub Aloha protocols. Detailed descriptions of the throughput analysis for a practical WSN with a limited number of users is given. The analytical model is verified using the Riverbed Modeler. The simulation results for throughput show a discrepancy between models for a finite node system and the current analytical model. As the spatial reuse of the network is limited by the antenna pattern, a discussion on the selection of the number of hub antennas is then given, based on achieving the highest possible throughput performance with realistic directional antennas. The analysis and simulation results show a 186% increase in throughput.

Introducing desired mutations into the genome of model organisms is a priority for all research focusing on protein function and disease modeling. The need to create stable mutant lines has resulted in the rapid advancement of genetic techniques over the last few decades from chemical mutagenesis and zinc finger nucleases to clustered regularly interspaced short palindromic repeats (CRISPR) and homology-directed repair (HDR). However, achieving consistently high success rates for direct mutagenesis in zebrafish remains one of the most sought-after techniques in the field. Several genes have been modified using HDR in zebrafish, but published success rates range widely, suggesting that an optimal protocol is required. In this review, we compare target genes, techniques, and protocols from 50 genes that were successfully modified in zebrafish using HDR to find the statistically best variables for efficient HDR rates.

The paper examines the variability of the Shielding Effectiveness of board level shields measured in a reverberation chamber at frequencies from 200 MHz to 20 GHz. Results show that at any particular frequency the Shielding Effectiveness exhibits a typical variability of +20 dB about the mean value.

Heart failure is the number one cause of mortality in the world, contributed to by cardiovascular disease. Many diseases of the heart muscle are caused by mutations in genes encoding contractile proteins, including cardiac actin mutations. Zebrafish are an advantageous system for modeling cardiac disease since embryos can develop without a functional heart. However, genome duplication in the teleost lineage creates a unique obstacle by increasing the number of genes involved in heart development. Four actin genes are expressed in the zebrafish heart:acta1b; actc1c;and duplicates ofactc1aon chromosome 19 and 20. Here, we characterize the actin genes involved in early zebrafish heart development usingin situhybridization and CRISPR targeting to determine which gene is best to model changes seen in human patients with heart disease. Theactc1aandacta1bgenes are predominant during embryonic heart development, resulting in severe cardiac phenotypes when targeted with CRISPRs. Targeting these two cardiac genes with CRISPRs simultaneously results in a more severe phenotype than their individual counterparts, with the results suggesting compensation for lost actin genes by other actin paralogues. Given the duplication of theactc1agene, we recommendacta1bas the best gene for targeted cardiac actin research.

Mutations in the α-cardiac actin ACTC1 gene cause dilated or hypertrophic cardiomyopathy. These diseases are the result of changes in protein interactions between ACTC protein and force-generating β-myosin or the calcium-dependent cardiac-tropomyosin (cTm) and cardiac troponin (cTn) regulatory complex, altering the overall contractile force. The T126I and S271F ACTC variants possess amino acid substitutions on the other side of actin relative to the myosin or regulatory protein binding sites on what we call the "dark side" of actin. The T126I change results in hyposensitivity to calcium, in accordance with the calcium sensitivity pathway of cardiomyopathy development while the S271F change alters the maximum in vitro motility sliding speed, reflecting a change in maximum force. These results demonstrate the role of actin allostery in the cardiac disease development.

In the article titled “A new conformal FDTD for lossy thin1panels” by M. R. Cabelloet al., the appearance of spiky antiresonances2in the simulation of the shielding properties of lossy thin-shell spherical3cavities by FDTD was categorized as spurious solutions. In this article,4we briefly clarify this topic and show that these solutions are not5really spurious in the common interpretation of the term. Actually, they6correspond to physical solutions appearing due to lack of symmetry,7inherent to the staggered colocation nature of field components in FDTD., Spanish MINECO and EU FEDER (MINECO, Spain) under Project TEC2016-79214-C3-3-R, COST Action under Grant IC1407 (ACCREDIT), EPSRC Studentship under Grant 1642594

Biomechanical stress and cytoskeletal remodeling are key determinants of cellular homeostasis and tissue responses to mechanical stimuli and injury. Here we document the increased activity of gelsolin, an actin filament severing and capping protein, in failing human hearts. Deletion of gelsolin prevents biomechanical stress-induced adverse cytoskeletal remodeling and heart failure in mice. We show that phosphatidylinositol (3,4,5)-triphosphate (PIP3) lipid suppresses gelsolin actin-severing and capping activities. Accordingly, loss of PI3Kα, the key PIP3-producing enzyme in the heart, increases gelsolin-mediated actin-severing activities in the myocardium in vivo, resulting in dilated cardiomyopathy in response to pressure-overload. Mechanical stretching of adult PI3Kα-deficient cardiomyocytes disrupts the actin cytoskeleton, which is prevented by reconstituting cells with PIP3. The actin severing and capping activities of recombinant gelsolin are effectively suppressed by PIP3. Our data identify the role of gelsolin-driven cytoskeletal remodeling in heart failure in which PI3Kα/PIP3 act as negative regulators of gelsolin activity., Gelsolin is an actin severing and capping protein that regulates cytoskeletal remodeling. Here the authors show that gelsolin is negatively regulated in the heart by PI3Kα‐ generated PIP3, and that loss of gelsolin activity prevents adverse cytoskeletal remodeling and heart failure.

This work focuses on the study of the stability of trapped soliton-like solutions of a (1 + 1)-dimensional nonlinear Schrödinger equation (NLSE) in a nonlocal, nonlinear, self-interaction potential of the form [ | ψ ( x , t ) | 2 + | ψ ( − x , t ) | 2 ] κ where κ is an arbitrary nonlinearity parameter. Although the system with κ = 1 (i.e. fully integrable case) was first reported by Yang (2018 Phys. Rev. E 98 042202), in the present work, we extend this model to the one in which κ is arbitrary. This allows us to compare the stability properties of the now trapped solutions to previously found solutions of the more usual NLSE with κ ≠ 1 which are moving soliton solutions. We show that there is a simple, one-component, nonlocal Lagrangian and corresponding action governing the dynamics of the system. Using a collective coordinate method derived from the action as well as assuming the validity of Derrick’s theorem, we find that these trapped solutions are stable for 0 < κ < 2 and unstable when κ > 2. At the critical value of κ, i.e. κ = 2, the solution can either collapse or blowup linearly in time when q 0 = 0, where q 0 is the center of the initial density ρ(x, t = 0) = ψ ⋆ ψ of the solution. For q 0 ≠ 0 the displaced solution collapses. When κ > 2 initial small displacements from the origin also lead to collapse of the wave function. This phenomenon is not seen in the usual NLSE.

The present study examined how the expression of enhanced green fluorescent protein (eGFP) and human cardiac actin (ACTC) in zebrafish Danio rerio influences embryonic heart rate (RH ) and the swim performance and metabolic rate of adult fish. Experiments with the adults involved determining the critical swimming speed (Ucrit , the highest speed sustainable and measure of aerobic capacity) while measuring oxygen consumption. Two different transgenic D. rerio lines were examined: one expressed eGFP in the heart (tg(cmlc:egfp)), while the second expressed ACTC in the heart and eGFP throughout the body (tg(cmlc:actc,ba:egfp)). It was found that RH was significantly lower in the tg(cmlc:actc,ba:egfp) embryos 4 days post-fertilization compared to wild-type (WT) and tg(cmlc:egfp). The swim experiments demonstrated that there was no significant difference in Ucrit between the transgenic lines and the wild-type fish, but metabolic rate and cost of transport (oxygen used to travel a set distance) was nearly two-fold higher in the tg(cmlc:actc,ba:egfp) fish compared to WT at their respective Ucrit . These results suggest that the expression of ACTC in the D. rerio heart and the expression of eGFP throughout the animal, alters cardiac function in the embryo and reduces the aerobic efficiency of the animal at high levels of activity.

Determination of the distribution of electromagnetic energy inside electrically large enclosed spaces is important in many electromagnetic compatibility applications, such as certification of aircraft and equipment shielding enclosures. The field inside such enclosed environments contains a dominant diffuse component due to multiple randomizing reflections from the enclosing surfaces. The power balance technique has been widely applied to the analysis of such problems; however, it is unable to account for the inhomogeneities in the field that arise when the absorption in the walls and contents of the enclosure is significant. In this paper, we show how a diffusion equation approach can be applied to modeling diffuse electromagnetic fields and evaluate its potential for use in electromagnetic compatibility applications. Two canonical examples were investigated: a loaded cavity and two cavities coupled by a large aperture. The predictions of the diffusion model were compared to measurement data and found to be in good agreement. The diffusion model has a very low computational cost compared to other applicable techniques, such as full-wave simulation and ray-tracing, offering the potential for a radical increase in the efficiency of the solution high frequency electromagnetic shielding problems with complex topologies.

Nonwoven carbon-fiber sheets are often used to form a conductive layer in composite materials for electromagnetic shielding and other purposes. While a large amount of research has considered the properties of similar idealized materials near the percolation threshold, little has been done to provide validated analytic models suitable for materials of practical use for electromagnetic shielding. Since numerical models consume considerable computer resource and do not provide the insight which enables improved material design, an analytic model is of great utility for materials development. This paper introduces a new theoretical model for the sheet conductance of nonwoven carbon-fiber sheets built on the theory of percolation for 2-D conducting stick networks. The model accounts for the effects of sample thickness, fiber angle distribution, and contact conductance on the sheet conductance. The theory shows good agreement with Monte Carlo simulations and measurements of real materials in the supercritical percolation regime where the dimensionless areal concentration of fibers exceeds about 50. The theoretical model allows the rapid prediction of material shielding performance from a limited number of manufacturing parameters.

This paper presents an experimental study and reports the monitored changes in the switching parameters (quoted in datasheets) of Insulated Gate Bipolar Transistors (IGBTs) when subjected to accelerated ageing through thermo-electrical overstress. The study describes how the accelerated ageing strategy was implemented. Tested IGBTs were characterized before and after accelerated ageing. Details are presented of the IGBT switching parameters characterization setup and the employed Double Pulse technique. Furthermore, the corresponding monitored changes in the turn-off delay time, fall time, energy loss during fall time, turn-off rate of change of collector voltage, turn-on delay time, rise time, energy loss during rise time, turn-on rate of change of collector current, reverse recovery time, peak reverse recovery current and energy loss during reverse recovery are presented and discussed.

The primary contribution of this paper lies in e valuating the potential be nefits of using directional antennas in wireless sensor networks to reduce node power consumption and improve fairness and throughput. The protocol helps improve throughput and reduce energy consumption by maximising spatial reuse and with a strategy to deal with overlap between antenna patterns without any additional complexity at the sensor nodes themselves. The protocol uses packets from the hub to estimate the transmission power re quire d by nodes, to avoid excess energy usage. The protocol is verified using RiverBed Modeler. Simulation results for fairness, throughput and node transmission energy requirement are presented, showing a reduction in av e rage transmission power by a factor of two with respect to the protocol without power control. Good fairness is demonstrated and throughput for a 4-antenna system is 2.17 times that of a single antenna system. The antenna pattern overlap, which is often assumed negligible, is shown to have a significant effect on throughput.

This paper presents calculated and measured Shielding Effectiveness data for shielded enclosures operated in the frequency range where the enclosure is reverberant. The calculated data are obtained from component measurements and are calculated using the Power Balance technique. The Shielding Effectiveness of the different cavities of an enclosure partitioned by stacked circuit cards is obtained.

We discuss the response of both moving and trapped solitary wave solutions of a nonlinear two-component nonlinear Schr\"odinger system in 1+1 dimensions to an anti-$\mathcal{PT}$ external periodic complex potential. The dynamical behavior of perturbed solitary waves is explored by conducting numerical simulations of the nonlinear system and using a collective coordinate variational approximation. We present case examples corresponding to choices of the parameters and initial conditions involved therein. The results of the collective coordinate approximation are compared against numerical simulations where we observe qualitatively good agreement between the two. Unlike the case for a single-component solitary wave in a complex periodic $\mathcal{PT}$-symmetric potential, the collective coordinate equations do not have a small oscillation regime, and initially the height of the two components changes in opposite directions often causing instability. We find that the dynamic stability criteria we have used in the one-component case is proven to be a good indicator for the onset of dynamic instabilities in the present setup., Comment: 28 pages, 7 figures

The finite-difference time-domain (FDTD) method is a numerical technique that is widely used to solve Maxwell's differential equations in the time domain [1]. Both space and time are discretized. Space is discretized into rectangular-shaped elements in two-dimensional (2-D) or cuboid elements in three-dimensional (3-D). Cuboid elements, where the electric fields are located on the edges of the cuboid and the magnetic fields are normal to the faces, are called Yee cells and are the fundamental elements of most FDTD methods [2]. By filling up the problem space with these cells, we obtain a 3-D mesh, where neighboring cells share edges and faces. Each cell has three associated electric and magnetic field components, while the other field components belong to adjacent cells. The properties of each cell are adjusted to represent materials such as dielectrics or conductors by adjusting the constitutive parameters used in the field equations in the corresponding cells, hence forming the geometrical structure of the problem to be solved. For example, Figure 1 shows a sphere and a version of the sphere discretized using cubic elements.

Absorption by the contents of an equipment enclosure, particularly printed circuit boards (PCBs), affect the enclosure's shielding performance. At high frequencies, this absorption can be quantified using the angle of arrival and polarization averaged absorption cross-section (ACS). However, there is no available data on the high-frequency absorption characteristics of modern PCBs. In this study, we apply a reverberation chamber to the determination of the average ACS of a large number of PCBs taken from contemporary information and communication technology (ICT) equipment to provide a unique and comprehensive dataset. The ACS was found to range from 4 × 10−4–10−2 m2 from 2–20 GHz and different classes of PCB could be identified according to their surface characteristics. The “shadowing effect” of densely packed PCBs was also quantified for a subset of the PCBs. It was found that the ACS of a PCB in the stack was reduced by 20%–40% compared to its value when isolated. By way of a review of the general power balance analysis of an electrically large populated equipment enclosure in an external environment, we show how the acquired data will be useful for future qualification methodologies for ICT enclosures and PCBs.

We present an alternative to the perturbative (in coupling constant) diagrammatic approach for studying stochastic dynamics of a class of reaction diffusion systems. Our approach is based on an auxiliary field loop expansion for the path integral representation for the generating functional of the noise induced correlation functions of the fields describing these systems. The systems we consider include Langevin systems describable by the set of self interacting classical fields ϕ i ( x , t ) in the presence of external noise η i ( x , t ) , namely ( ∂ t − ν ∇ 2 ) ϕ − F [ ϕ ] = η , as well as chemical reaction annihilation processes obtained by applying the many-body approach of Doi–Peliti to the Master Equation formulation of these problems. We consider two different effective actions, one based on the Onsager–Machlup (OM) approach, and the other due to Janssen–deGenneris based on the Martin–Siggia–Rose (MSR) response function approach. For the simple models we consider, we determine an analytic expression for the Energy landscape (effective potential) in both formalisms and show how to obtain the more physical effective potential of the Onsager–Machlup approach from the MSR effective potential in leading order in the auxiliary field loop expansion. For the KPZ equation we find that our approximation, which is non-perturbative and obeys broken symmetry Ward identities, does not lead to the appearance of a fluctuation induced symmetry breakdown. This contradicts the results of earlier studies.

Average absorption cross section can be measured in a reverberation chamber with an uncertainty estimated from the number of independent samples of the chamber transfer function taken during the measurement. However, the current uncertainty model does not account the loading effect of the object being measured or the presence of nonstochastic energy in the chamber, as characterized by the Rician K -factor. Here, the uncertainty model for the absorption cross-section measurements has been extended to include both of these effects for the case of stepped mechanical tuning with a paddle and frequency tuning. The extended uncertainty formula has been applied to predict the range over which absorption cross-section measurements can be made with a defined relative uncertainty in a chamber of given geometry, using both simple models for the reverberation chamber and the measured quality-factor and K -factor. The model has been validated using measurements on a set of absorbing cubes of different sizes compared to Mie Series calculation on sphere of equivalent surface area. The extended error model is particularly utile for the design of reverberation chambers and experiments for absorption cross-section measurements across a wide range of application areas.

We present trapped solitary wave solutions of a coupled nonlinear Schr\"odinger system in $1$+$1$ dimensions in the presence of an external, supersymmetric and complex $\mathcal{PT}$-symmetric potential. The Schr\"odinger system this work focuses on possesses exact solutions whose existence, stability, and spatio-temporal dynamics are investigated by means of analytical and numerical methods. Two different variational approximations are considered where the stability and dynamics of the solitary waves are explored in terms of eight and twelve time-dependent collective coordinates. We find regions of stability for specific potential choices as well as analytic expressions for the small oscillation frequencies in the collective coordinate approximation. Our findings are further supported by performing systematic numerical simulations of the nonlinear Schr\"odinger system., Comment: 30 pages, 8 figures

Medium access control (MAC) protocols play a vital role in making effective use of a multiple access channel as it governs the achievable performance such as channel utilization and corresponding quality of service of wireless sensor networks (WSNs). In this paper, a virtual carrier sensing directional hub (VSDH) MAC protocol incorporating realistic directional antenna patterns is proposed for directional single hub centralized WSNs. While in most instances, MAC protocols assume idealized directional antenna patterns, the proposed VSDH-MAC protocol incorporates realistic directional antenna patterns to deliver enhanced link performance. We demonstrate that the use of directional antennas with a suitable MAC protocol can provide enhanced communication range and increased throughput with reduced energy consumption at each node, compared to the case when only omnidirectional antennas are used. For the scenarios considered in this study, results show that the average transmit power of the sensor nodes can be reduced by a factor of two, and at the same time offer significantly extended lifetime.

Sarcomere assembly and maintenance are essential physiological processes required for cardiac and skeletal muscle function and organism mobility. Over decades of research, components of the sarcomere and factors involved in the formation and maintenance of this contractile unit have been identified. Although we have a general understanding of sarcomere assembly and maintenance, much less is known about the development of the thin filaments and associated factors within the sarcomere. In the last decade, advancements in medical intervention and genome sequencing have uncovered patients with novel mutations in sarcomere thin filaments. Pairing this sequencing with reverse genetics and the ability to generate patient avatars in model organisms has begun to deepen our understanding of sarcomere thin filament development. In this review, we provide a summary of recent findings regarding sarcomere assembly, maintenance, and disease with respect to thin filaments, building on the previous knowledge in the field. We highlight debated and unknown areas within these processes to clearly define open research questions.

During their lifetime, power semiconductor devices such as Insulated Gate Bipolar Transistors (IGBTs) can suffer from different failure mechanisms. This paper reports the monitored changes in the electrical parameters of tested IGBTs when subjected to accelerated ageing through thermo-electrical overstress. The changes are indicative that the device is at the onset of failure and hence can be utilized within prognostic techniques so as to determine the health state of the device. The study describes how the accelerated ageing strategy was implemented providing details of the implemented hardware and software. Tested IGBTs were characterized before, durina and after accelerated ageing. Details of the IGBT characterization setup are provided. Furthermore, the corresponding monitored changes in the die-attach X-Ray imagery, gate threshold voltage, collector leakage current, transfer characteristics, transconductance, output characteristics and internal freewheeling diode forward characteristics are presented and discussed.

This paper presents some thoughts on the meaning of shielding effectiveness (SE) for a real enclosure. It is demonstrated that the conventional measurement of SE is a value specific to the particular measurement and is not necessarily representative of the enclosure in any practical situation, including a different measurement. The SE of an enclosure depends both on the enclosure contents, including the measurement antenna and the effective transmission cross-section of the energy coupling mechanisms such as apertures, penetrations, seams and diffusion through walls.