Mode Theory Research Articles

The influence of practice experiences on feelings of role proficiency in emergency nurse practitioners: A phenomenological study

IntroductionThis research explores how emergency nurse practitioners (ENPs) become role proficient given experience variation and lack of role standardisation. AimTo understand how ENPs experiences in practice influence their feelings of role proficiency. MethodsA hermeneutic phenomenological study was undertaken utilizing an interpretive standpoint. A two-phase approach was adopted with ten participants using a digital diary informing a semi-structured interview. A three-stage data analysis approach was applied. FindingsSix themes emerged: the meaning of role proficiency, relationships, confidence, learning and knowledge, exposure and experience, and care. Models of proficiency and its development are presented. DiscussionProficiency is defined where confidence in the components that proficiency consists of and their application to each clinical presentation is required. Proficiency is a continuum supported by regulatory mode theory. Inconsistency of role understanding gives rise to three ENP groups, resistors, maintainers, and innovators. ConclusionRole clarity is required to establish a consistent culture within organisations founded on the voice of the ENP as captured in this research. This model of proficiency be incorporated in ENP role development for current and future ENPs.

Broadband Acoustic Field in a Shallow-Water Waveguide with an Inhomogeneous Bottom

A broadband (35–1000 Hz) sound field formed by a point source in a shelf zone with inhomogeneous bottom sediment structure is studied using numerical modeling. The shelf depth is about 30 m and the maximum distance is 10 km. The transitional zone from the bottom with a sound speed of 1400 m/s to the bottom with a speed of 1600 m/s is chosen as the model inhomogeneity. The normal mode theory and wide-angle parabolic equations are used for sound field calculations. Numerical experiments show that the manifestation of horizontal refraction is noticeable at low frequencies (below 100 Hz). It leads to an increase in the amplitude of the low-frequency sound pulse propagating along the transitional zone by more than 10 dB in comparison with a similar waveguide with a homogeneous bottom. At frequencies above 100 Hz, the dominant effect is the mode coupling, causing the appearance of quasi-periodic oscillations of modal amplitude in the frequency domain. The conclusions from the simplified model are confirmed by calculations for the real structure of bottom sediments in the Kara Sea.

Singular Points Location Pattern Analysis based on Modes Interference

<p>Given the lack of research on the regularity of distribution of singular points, the singular points under different influence factors are analyzed. The location of singular points for adjacent modes group (AMG) generated by the interference modes is derived using normal modes theory in the far field of the ideal shallow waveguide. The singular points are verified by simulation, which compares the distribution of the acoustic field and singular points. Moreover, it is concluded that the number and distribution of singular points in the period of the interference structure of the field (PISF) has a relationship with order (lower order of AMG) and adjacent order (difference between two orders of AMG). The arrangement of upper-lower-two-points increases by 2 with each increase of order and is distributed at both ends of PISF. The arrangement of rhombic-four-points increases by 1 with each increase of adjacent order and increases alternately at both ends of PISF. Meanwhile, there is a periodic relationship between the depth of the source and the location of singular points.</p> <p> </p>

Quadruple Plasmon-Induced Transparency and Dynamic Tuning Based on Bilayer Graphene Terahertz Metamaterial.

This study proposes a terahertz metamaterial structure composed of a silicon-graphene-silicon sandwich, aiming to achieve quadruple plasmon-induced transparency (PIT). This phenomenon arises from the interaction coupling of bright-dark modes within the structure. The results obtained from the coupled mode theory (CMT) calculations align with the simulations ones using the finite difference time domain (FDTD) method. Based on the electric field distributions at the resonant frequencies of the five bright modes, it is found that the energy localizations of the original five bright modes undergo diffusion and transfer under the influence of the dark mode. Additionally, the impact of the Fermi level of graphene on the transmission spectrum is discussed. The results reveal that the modulation depths (MDs) of 94.0%, 92.48%, 93.54%, 96.54%, 97.51%, 92.86%, 94.82%, and 88.20%, with corresponding insertion losses (ILs) of 0.52 dB, 0.98 dB, 1.37 dB, 0.70 dB, 0.43 dB, 0.63 dB, 0.16 dB, and 0.17 dB at the specific frequencies, are obtained, achieving multiple switching effects. This model holds significant potential for applications in versatile modulators and optical switches in the terahertz range.

The Influence of Bottom Sediment on the Propagation of Caustic Beams in Oceanic Waveguides

Numerical modeling with the use of mode theory was used to investigate the regularities of the spatial (depth and horizontal distance) distribution of the acoustic field intensity formed by multiple interaction of a caustic beam with a layered bottom in a shallow oceanic waveguide with an underwater sound channel open to the bottom. It has been established that at the values of the sound velocity at the upper boundary in the sedimentary layer, less than the sound velocity at the bottom in the water layer, the formation of a multi-beam structure of the acoustic field is possible. It was found that, starting from certain distances, newly formed beams can play the main role in the spatial distribution of the acoustic field intensity.

Coupling-Assisted Quasi-Bound States in the Continuum in Heterogeneous Metasurfaces

In this paper, we present a Bound states in the continuum (BIC) metamaterial in heterogeneous structures based on the coupled mode theory. We find the more general physical parameters to represent BIC, which are the resonant frequencies and corresponding phases of metamaterial structures. Therefore, BIC metamaterial comes from the equal value of the resonant frequencies and phases of metamaterial structures which are not only for homogeneous structures. Meanwhile, if one of the metamaterial structure's resonant frequency and phase vary by varying geometry, we can obtain the quasi-BIC instead of the broken symmetry of homogeneous structures. In this paper, we provide the BIC and quasi-BIC with one example of two heterogeneous structures which are cut wire (CW) and Split-Ring Resonator (SRR) and it widely extends the metamaterial BIC beyond common sense. Furthermore, we demonstrate the simulation results and experimental results to proof our idea.

Modalities of Daughters in Patriarchal Traditions in the Batak Tribe Society

Batak society is a traditional society that adheres to a patriarchal system that places men as power holders and dominates roles in the group system. In Batak culture, the highest decision is in the hands of men, so there are differences in values between girls and boys. Child modality can be defined as the way of parents in modality, namely supporting, sustaining and being the basis for a child to develop in his life. The purpose of this research is to find out how the modality of girls in Batak society is. The subjects of this study were 6 people who were members of the United Batak Youth PAC Bathin Solapan. The method used is qualitative with the technique of determining informants using a purposive sampling technique. The theory used is the modality theory of Pierre Bourdieu with data collection techniques using interview and observation techniques. Based on the results of the research, the modality for girls is implemented well, even though the presence of patriarchal traditions in Batak society does not prevent the informants from giving the best for their daughters.

A shared aperture antenna with reconfigurable pattern by common and differential modes

AbstractIn this letter, a compact pattern‐reconfigurable (PR) antenna for indoor communication is proposed, which can provide one conical, one broadside, and two tilted patterns. The proposed antenna comprises a shared radiation patch with two highly isolated ports and a reconfigurable feeding network. By activating each port independently, a dipole mode with broadside pattern and a monopole mode with conical pattern are acquired, respectively. Meanwhile, inspired by the theory of common and differential modes, two tilted patterns toward and are realized by combining dipole and monopole modes. As a result, four‐type reconfigurable patterns can be obtained. To realize reconfigurability, a functional reconfigurable feeding network is designed with innovation. The proposed antenna is fabricated and measured. The measured overlapped −10 dB impedance bandwidth is 3.28–3.71 GHz (12.3%), and the peak radiation efficiency is superior to 82.7%. The experimental results indicate that the proposed PR antenna has a wide bandwidth and stable radiation patterns, which exhibits attractive potential for fifth‐generation indoor communication in sub‐6 GHz.

Analytical investigation of unidirectional reflectionless phenomenon near the exceptional points in graphene plasmonic system.

We propose a two-dimensional array made of a double-layer of vertically separated graphene nanoribbons. The transfer matrix method and coupled mode theory are utilized to quantitatively depict the transfer properties of the system. We present a way to calculate the radiative and the intrinsic loss factors, combined with finite-difference time-domain simulation, conducting the complete analytical analysis of the unidirectional reflectionless phenomenon. By adjusting the Fermi energy and the vertical distance between two graphene nanoribbons, the plasmonic resonances are successfully excited, and the unique phenomena can be realized at the exceptional points. Our research presents the potential in the field of optics and innovative technologies to create advanced optical devices that operate in the mid-infrared range, such as terahertz antennas and reflectors.

Cascade nonlinear observer design for large amplitude of slosh variables in spacecraft maneuver with liquid propellant tank

Slosh dynamics in a liquid propellant tank during a spacecraft maneuver can have an effect on the system stability and potentially lead to critical problems for the mission operation. In particular, the fuel sloshing problem has drawn significant attention in aerospace applications where a large portion of the gross weight is comprised of liquid fuel. Recently, many active control methods have been introduced as alternatives to passive approaches. However, the majority of these methods basically require the full-state condition. To guarantee the availability of the full-state condition, this paper proposes a cascade nonlinear state observer based on the sliding mode theory for estimating the unmeasurable slosh variables in a planar model. Additionally, for large amplitude estimation, a complete nonlinear mathematical model with a pendulum analogy is formulated without a linearization process. The stability analysis is theoretically proven by Lyapunov method. The effectiveness is demonstrated through simulations, and the performance comparison with a different observer method is also presented in the results.

Design of Wideband Decoupling Antenna Array for 5G Smartphones at N77/N78/N79/WLAN 5 GHz Bands

We propose a broadband decoupled antenna pair for 5G mobile terminals. The broadband decoupled design of this antenna pair is based on the characteristic mode theory (CMA) and defective ground structure. First, CMA is applied to obtain the characteristic current distribution of the antenna, then the characteristic current sensitive regions are optimized to make the antenna introduce new modes and obtain a wide bandwidth. After that, an antenna pair is added with defective ground structure to obtain a wideband decoupled antenna pair that has small size and high isolation. Next, an eight-element MIMO antenna system is constructed with the obtained broadband decoupled antenna pair, and a composite decoupling technique consisting of defective ground structure (DGS) and decoupling strip is applied to the two antenna pairs on the same side of the bezel to improve the isolation. The simulation and prototype test results show that the eight-element MIMO antenna with −10 dB bandwidth of 3.28~5.85 GHz mainly covers the N77/N78/N79/WLAN 5 GHz band, and the antenna pair are only 1.6 mm apart with good isolation (−16.7 dB), the ECC is less than 0.01, and it has a good total efficiency at the main operating frequency. Finally, the effect of a user’s hand on the antenna is briefly analyzed to verify the robustness of the proposed MIMO antenna system.

Design of a Dual-Band WiFi Antenna Using the Theory of Characteristic Modes and Nested Chinese Characters

In this paper, a dual-band WiFi antenna and its Multiple Input Multiple Output (MIMO) system application is designed, fabricated, and measured based on the Chinese characters “Men” and “Wei”. The antenna uses a 40 × 40 × 1.6 mm3 FR4 substrate to analyze the combinatorial structure of Chinese characters using the theory of characteristic modes, to optimize the antenna dimensions by analyzing the mode current distribution, and to broaden the antenna bandwidth by etching rectangular slots on the ground. The measured and simulated results show that the four-element MIMO antenna covers 5.68–8.01 GHz, the isolation between the antennas is higher than 20 dB in the working band, the envelope correlation coefficient and the channel capacity losses of the simulation are lower than 0.001 and 0.18 bits/s/HZ, respectively. The efficiency of the antenna is higher than 90%, and it can be used for WiFi communication bands (5.8 GHz and 6 GHz).

Advances in imaging techniques of the blood-brain barrier and clinical application.

The blood-brain barrier (BBB) is an important structure that maintains the normal function of the central nervous system (CNS). The functional structure of BBB is closely related to diseases of CNS, including degenerative diseases, brain tumours, traumatic brain injury, stroke, etc. Imaging methods were commonly used to monitor the integrity of BBB, such as DCE-MRI, DSC-MRI, and PET, this contributes to understand the process of related diseases and develop appropriate treatment options. In recent years, many studies had shown that the MRI methods (ASL, IVIM, CEST, etc.) could evaluate blood-brain barrier function, which use endogenous contrast agents and become an increasingly great concern. Another image methods (FUS, uWB-eMPs) can open up the normal BBB, allowing macromolecular drugs across the locally opening BBB, which could be beneficial to the treatment of some brain diseases. In this review, we briefly introduce the theory of BBB imaging modalities and its clinical application.

Modal Reliabilism as A Modal Normativism Approach

Amie Thomasson points out that the rationalist approaches to modal epistemology usually face the challenges of integration problem and reliability problem,due to their descriptive and realistic assumptions about modal facts and modal properties.Thomasson instead defends a modal normativism position. George Bealer's theory of modal reliabilism can be seen as a more complete approach to modal normativsim. It can further explain the conundrum of integration problem and reliability problem. Therefore, the modal reliabilism theory as a modal normativism approach is worth defending.

Integrated Bragg grating filters based on silicon-Sb2Se3 with non-volatile bandgap engineering capability.

Integrated optical filters show outstanding capability in integrated reconfigurable photonic applications, including wavelength division multiplexing (WDM), programmable photonic processors, and on-chip quantum photonic networks. Present schemes for reconfigurable filters either have a large footprint or suffer from high static power consumption, hindering the development of reconfigurable photonic integrated systems. Here, a reconfigurable hybrid Bragg grating filter is elaborately designed through a precise, modified coupling mode theory. It is also experimentally presented by integrating non-volatile phase change material (PCM) Sb2Se3 on silicon to realize compact, low-loss, and broadband engineering operations. The fabricated filter holds a compact footprint of 0.5 µm × 43.5 µm and maintains a low insertion loss of < 0.5 dB after multiple levels of engineering to achieve crystallization. The filter is able to switch from a low-loss transmission state to the Bragg reflection state, making it a favorable solution for large-scale reconfigurable photonic circuits. With a switching extinction ratio over 30 dB at 1504.85 nm, this hybrid filter breaks the tradeoff between insertion loss and tuning range. These results reveal its potential as a new candidate for a basic element in large-scale non-volatile reconfigurable systems.

A source depth discrimination method based on wavenumber measured by bottom-mounted HLA

In research into underwater acoustics, the ability to differentiate submerged sources from surface sources could meet multiple applications. By using a bottom-mounted Horizontal Line Array (HLA), a solution to the problem of acoustic source depth discrimination in a downward-refracting underwater environment is presented. The testing problem is considered by beamforming in the modal domain. According to wavenumber offsets in the wavenumber spectra, a source depth feature is detected. The phenomenon is explained in terms of mode theory, using the concept of mode trapping. The decision metric is built based on the Accumulated Relative Wavenumber Offset (ARWO) derived by subarrays and broadband processing, then the simulation result reveals that the source can be correctly discriminated. Without mode matching or mode filtering, the method has high computational efficiency. In addition, the applicability for bottom-mounted HLA and the sediment independence of this method is proved. Finally, a moving surface source and a dipping submerged source during an experiment conducted in the South China Sea are taken into consideration. The source-depth characteristic is magnified by the ARWO. Over test trials, the classifier provides a satisfactory effect, with which the depth discrimination method is well explained.

Clinamen, necessity and modern receptions of epicureanism:

Early modern readings of Epicureanism carried various prejudices and the term epicurean often designated an impious and potentially dangerous thinker. This was the case for Dutch philosopher Baruch Spinoza whose contemporaries compared his doctrine to Epicureanism on several occasions. However, how accurate would it be to affirm that Spinoza’s philosophy belongs to the neo-epicurean tradition? We find such a comparison in many 17th and 18th century texts, especially in works written by critics of his thought, such as François Fénelon or Jean La Placette. Epicurean doctrine on chance was compared to Spinoza’s theory on necessity, but despite the prejudices of the comparison, both Epicurus’s and Spinoza’s philosophies had an important influence on the Enlightenment, namely on French materialists. In our paper, we proceed to an analysis of this comparison and shed light on one of the most influential receptions of Epicurus’s philosophy in modernity. In this perspective, we show their inherent relation and focus more particularly on their modal theories; we thus examine the reasons why- contrary to other cases- the comparison was based less on ethical and mostly on metaphysical matters and we show at what extent it is legitimate.

Ballooning theory for micro-tearing mode in tokamak

This paper aims to investigate the impact of magnetic drift on the linear micro-tearing mode by using a kinetic approach to derive a reduced two-field eigen system in real space. Since the magnetic drift in real space has derivatives, it is more efficient to solve the mode equations in a Fourier-ballooning representation using the two-dimensional (2D) ballooning transform. The lowest-order eigen system in the Fourier-ballooning representation consists of two integral equations, which are numerically solved using the finite difference method for both eigenvalues and wave functions. The main results will be presented through graphical eigenvalue scans for each parameter. Furthermore, we present a graphical comparison between the predictions of the ballooning theory and GENE gyrokinetic code simulation in the pedestal region.

Acoustic scattering in lined panel cavities with membrane interfaces.

Noise control strategies are extremely important in industry. Acoustic liners and elastic membranes, which absorb or attenuate sound waves, are key components in ducting systems for active and passive noise reduction. In this article, we design and examine a reactive liner panel cavity with flexible interfaces. The lined panel cavity system is comprised of elastic membranes at the interfaces. The aim is to couple the incoming duct modes with the flexible components and then with the localized modes in the lined region. The governing equations for the lined panel cavity system are solved using a mode-matching technique that assures continuity of the normal velocities at the interfaces and can handle a range of strong coupling and higher-order edge conditions in contrast to the coupled mode theory. The aim is to investigate the effects of reactive liners and elastic membrane interfaces on wave scattering through the proposed acoustic enclosure design. The scattering performance of the proposed lined panel cavity is evaluated in terms of the reflected and transmitted energy flux as well as transmission loss. Analysis shows that the resonances at the membrane interfaces coupled to the linear cavities have a direct impact on power variations and the maximum transmission loss.

Thickness insensitive nanocavities for 2D heterostructures using photonic molecules

Abstract Two-dimensional (2D) heterostructures integrated into nanophotonic cavities have emerged as a promising approach towards novel photonic and opto-electronic devices. However, the thickness of the 2D heterostructure has a strong influence on the resonance frequency of the nanocavity. For a single cavity, the resonance frequency shifts approximately linearly with the thickness. Here, we propose to use the inherent non-linearity of the mode coupling to render the cavity mode insensitive to the thickness of the 2D heterostructure. Based on the coupled mode theory, we reveal that this goal can be achieved using either a homoatomic molecule with a filtered coupling or heteroatomic molecules. We perform numerical simulations to further demonstrate the robustness of the eigenfrequency in the proposed photonic molecules. Our results render nanophotonic structures insensitive to the thickness of 2D materials, thus owing appealing potential in energy- or detuning-sensitive applications such as cavity quantum electrodynamics.