Asymmetric Plane Research Articles

Amorphizing MnIn2S4 Atomic Layers Create an Asymmetrical InO1S5 Polarization Plane for Photocatalytic Ammonia Synthesis and CO2 Reduction.

Building a polarization center is an effective avenue to boost charge separation and molecular activation in photocatalysis. However, a limited number of polarization centers are usually created. Here, a polarization plane based on two-dimensional (2D) atomic layers is designed to maximize the surface polarization centers. The Mn in a 2D crystal lattice is etched from the MnIn2S4 atomic layers to build a consecutive symmetry-breaking structure of isolated InO1S5 sites. More charges aggregate around O, making the isolated InO1S5 sites highly polarized. Due to the formation of the InO1S5 polarization plane, an enormous polarized electric field is formed perpendicular to the 2D atomic layers and the carrier lifetime can be prolonged from 93.2 ps in MnIn2S4 to 1130 ps in amorphous MnxIn2Sy. Meantime, the formed large charge density gradient favors coupling and activation of small molecules. Benefiting from these features, a good NH3 photosynthesis performance (515.8 μmol g-1 h-1) can be realized over amorphous MnxIn2Sy, roughly 2.5 and 48.9 times higher than those of MnIn2S4 atomic layers and bulk MnIn2S4, respectively. The apparent quantum yields reach 5.4 and 3.3% at 380 and 400 nm, respectively. Meanwhile, a greatly improved CO2 reduction activity is also achieved over MnxIn2Sy. This strategy provides an accessible pathway for designing an asymmetrical polarization plane to motivate photocatalysis optimization.

Dual‐port circularly polarized wideband dielectric resonator antenna for S‐band application

SummaryThis article explains the design and implementation of a multiple input multiple output (two‐port) antenna, based on dielectric resonators. The antenna design not only demonstrates high isolation between its ports but also showcases robust diversity performance. The initial step introduces an asymmetrical ground plane radiating stub microstrip feed for circular polarization generation in a single‐port cylindrical dielectric resonator antenna (CDRA). This approach utilizes an asymmetrical ground plane and incorporates three radiating stubs connected to a microstrip feed line to generate HEM11δ modes in a cylindrical DRA. The proposed dual‐port CDRA offers high impedance bandwidth of 29.73% (2.95–3.98 GHz) and the axial ratio falls below 3 dB specifically from 3.01–3.35 GHz. The antenna demonstrates left‐handed circularly polarized fields with an average gain of 4.95 dBi and a radiation efficiency of 90.56%. All of these characteristics make the developed radiator appropriate for WiMAX (3.3–3.5 GHz) applications.

Development and characterization of a composite material with geopolymer matrix obtained by incorporation of microparticles from plastic bottles

The composite material with a geopolymer matrix of 7 M molarity, obtained by incorporating microparticles from plastic bottles is developed and characterized in the present paper. To do this, we made cylindrical specimens whose the diameters are the half of their heights and stored them at a temperature of (31±2°C). The compression test using a hydraulic press is carried out, as well as the thermal characterization test using a device respecting the experimental method of the asymmetric hot plane, which was used to determine the thermal conductivity, the volumetric heat capacity, the effusivity and the diffusivity. Then optical characterization tests on hardened samples were carried out, namely chemical analyses of the composition of the kaolin, and particle size characterization of the raw microscopic imaging of the specimens. The results found showed that as the amount of polyethylene terephthalate increases, the compressive strength decreases by 33.65 % for 10%polyethylene terephthalate and 67.77 % for 20 % polyethylene terephthalate. According to the thermal conductivity, it improves with the percentage of polyethylene terephthalate added as: at 10% it is 1.19Wm−1K−1 and at 20%, one has 0.595Wm−1K−1; similarly for effusivity where we obtained 1376.05 JK−1m−2s−1/2 and 560.81 JK−1m−2s−1/2 for 0 and 20% respectively. According to these results, the use of polyethylene terephthalate aggregates as a partial substitute of aluminosilicate raw material for the development of a composite can be a good alternative for recycling plastic bottle waste. The composite obtained could be used for the manufacture of ceiling lights and brick facings, and therefore would significantly reduce the amount of waste plastic produced every day in environment.

Enhanced Circularly Polarized Antenna for Body Centric Communication

Abstract: This study introduces a miniaturized circularly polarized ultra-wideband (UWB) antenna designed specifically for body-centric communication applications, with a focus on its performance across different frequencies. Fabricated on jean fabric, the antenna offers exceptional flexibility and seamless integration into clothing, making it ideal for wearable devices. The design achieves circular polarization through the utilization of an asymmetric stepped L-shaped ground plane and a crossshaped stub integrated into the radiator structure.Operating across the UWB frequency spectrum ranging from 3 GHz to 9.5 GHz, the antenna exhibits consistent and reliable performance in terms of gain, radiation pattern, and current distribution. ensuring effective signal transmission and reception. Importantly, the antenna complies with FCC specific absorption rate (SAR) limits, ensuring safety in wearable applications.Throughout the frequency range, the antenna maintains an omnidirectional radiation pattern, facilitating reliable on-body communication regardless of orientation. This characteristic is crucial for maintaining connectivity and signal quality in body-centric communication systems.Analysis of the current distribution confirms the antenna's effectiveness across different frequency bands, further validating its performance and suitability for body-centric communication applications.

A Kirigami Multi‐Stable Flexible Gripper with Energy‐Free Configurations Switching

Inspired by the kirigami and recombination mechanism, a kirigami flexible gripper is presented. The configuration variation behaviors are realized by recombinant kirigami segments, and thus, with only head segment actuation, the gripper slickly deforms among different configurations. Revolutionizing the conventional deployable systems, the proposed design methodology can realize configuration variation‐locking integration, and reusing of multi‐stability property. To realize rapid configuration switching with the lowest energy input, a nested origami actuation, called trigger structure, is given. Furthermore, advanced design for the trigger structure is carried out, broadening the bistable state to four‐stable geometric configurations for enhanced reachable space of the flexible gripper. By combining the design of the advanced trigger structure, the flexible gripper enables an energy‐free switching behavior between deployed and curled configurations in symmetrical and asymmetrical planes. The asymmetrical configurations, induced by the multi‐stability property of the advanced trigger structure, make the flexible gripper appropriate for various moving velocities capture. The proposed kirigami multi‐stable flexible gripper has significant capture capability for moving targets with different types and motion attitudes. Summarily, the proposed kirigami multi‐stable flexible gripper opens a new avenue for flexible robots, with potential applications in space exploration, grippers, and beyond.

A wideband X‐band circularly polarized printed monopole antenna backed by AMC reflector for 5G/IoT CubeSat applications

AbstractThis letter presents a coplanar waveguide‐fed printed monopole antenna backed by an artificial magnetic conductor (AMC) reflector. The proposed monopole antenna achieves circular polarization by loading the monopole with a printed coil and using an asymmetric ground plane. In addition, the AMC increases the antenna gain while maintaining a wide axial ratio (AR) bandwidth. The unit cell of the AMC is based on a Minkowski‐like prefractal geometry. The antenna is fabricated and measured with a total size of 1.07 λ0 × 1.07 λ0 × 0.25 λ0 at the operating frequency of 8.5 GHz. The measured results show a wide −10 dB impedance bandwidth of 26.9% (7.12–9.38 GHz), a wide 3 dB AR bandwidth of 22.23% (8–9.89 GHz) as well as a peak gain of 8.3 dBi at 8.5 GHz. This is significantly better than comparable antennas in addition to this design being the smallest in size.

Dual band circularly polarized CPW monopole antenna inspired by metasurface reflector

A high gain, dual-band circular polarized coplanar waveguide (CPW) patch antenna with a metasurface reflector was proposed and demonstrated in this paper. Using a FR4 substrate with a 0.8 mm thickness, an asymmetrical ground plane was made for a CPW patch antenna. The proposed antenna exhibited dual-band characteristics having reflection coefficient (S11) below − 10 dB from 1.70 GHZ to 3.02 GHz with a bandwidth of 52.38% and 4.59–6.69 GHz with a bandwidth of 42.16%. The average gain was 3.2 dBi in the lower band & 2.5 dBi in the upper band with 3 dB axial ratio of 27.1% bandwidth in a lower band. A metasurface reflector was placed along the proposed antenna with foam as a dielectric between them to increase the gain and bandwidth. The antenna, when combined with the metasurface reflector, achieved an impedance bandwidth of 37.8% in the 1st band, 63% in the 2nd band and both the bands exhibits circular polarization with a 3 dB axial ratio of 57% in the 1st band and 33.02% in the 2nd band. The average gain was 7dBi, with a maximum gain of 7.9dBi at 2.4 GHz. A prototype of an antenna & metasurface reflector was fabricated and measured results were found to be good in comparison with simulated results.

Numerical and Experimental Analysis of the Mode I Interlaminar Fracture Toughness in Multidirectional 3D-Printed Thermoplastic Composites Reinforced with Continuous Carbon Fiber.

It is well known that the use of continuous reinforcing fibers can largely improve the typical low in-plane mechanical properties of 3D-printed parts. However, there is very limited research on the characterization of the interlaminar fracture toughness of 3D-printed composites. In this study, we investigated the feasibility of determining the mode I interlaminar fracture toughness of 3D-printed cFRP composites with multidirectional interfaces. First, elastic calculations and different FE simulations of Double Cantilever Beam (DCB) specimens (using cohesive elements for the delamination, in addition to an intralaminar ply failure criterion) were carried out to choose the best interface orientations and laminate configurations. The objective was to ensure a smooth and stable propagation of the interlaminar crack, while preventing asymmetrical delamination growth and plane migration, also known as crack jumping. Then, the best three specimen configurations were manufactured and tested experimentally to validate the simulation methodology. The experimental results confirmed that, with the appropriate stacking sequence for the specimen arms, it is possible to characterize the interlaminar fracture toughness in multidirectional 3D-printed composites under mode I. The experimental results also show that both initiation and propagation values of the mode I fracture toughness depend on the interface angles, although a clear tendency could not be established.

Influence on the lateral response of offshore pile foundations of an asymmetric heart-shaped scour hole

The presence of local scour seriously jeopardizes the safe operation of offshore wind power systems, as local scour leads to the formation of scour holes, which will decrease the bearing capacity of the foundations of these structures. Due to the directionality of waves and currents, scour holes typically have an asymmetric plane shape that creates unequal soil pressure on each side of the pile, and this pressure difference will have a more unfavorable impact on the pile lateral response than that of a scour hole with a symmetric geometry. In this study, an asymmetric heart-shaped scour hole is defined, and parametric analyses are performed to determine the pile lateral response using a three-dimensional (3D) finite element (FE) method in which the scour hole dimensions and the loading directions were varied. As the scour depth increased from 1.0D to 5.0D, the difference in the reduction ratio between the pile lateral capacities for the two scour hole shapes increased from 0.2% to 7.0%, while the gap in the pile bending moments decreased. Moreover, the results indicated that a heart-shaped scour hole was not sensitive to changes in the side slope angle. The pile lateral capacity was found to be lowest when the lateral load was applied negatively along the y axis; the gap in the pile maximum bending moments for the three loading directions was 90 kN·m, and the gap reduced as the scour depth increased.

Numerical analysis of scattering fields by a multiple plane grating using shadow theory.

In the shadow theory, a new description of electromagnetic fields using scattering factors has been employed. This paper presents a new numerical method based on scattering factors for the scattering problem of a composite dielectric grating embedded with conducting strips. The scattering factors for the primary fields, which are based on the assumption of conducting strips being removed completely and those for the secondary fields generated by the surface electric currents on conducting strips, are introduced. The presented method is formulated to obtain scattering factors for the total fields and Joule losses for propagating wave and evanescent wave incidences from the currents determined by using the Galerkin procedure. Numerical examples are given for an asymmetric multiple plane grating consisting of conducting strips. The scattering properties and the normalized Joule losses are calculated for propagating wave and evanescent wave incidences. It is shown that the diffraction efficiencies and scattering factors hold the symmetries on the reciprocity in the case of resistive plane gratings.

Improvement of the energy efficiency of buildings: Thermal characterization of an ecological building material based on industrial cotton waste

The aim of this work is to study the thermal characteristics of a concrete reinforced with cotton waste fiber for building construction. The concrete used was formulated with the Dreux-Gorisse method and has a compressive strength of 14.13 MPa. The fiber-reinforced concrete contains 0.1% to 0.8% of fibers by mass. The thermal properties were determined by the asymmetric hot plane method used with a DesProTherm device. Other properties were also computed. The results show that the density of the concretes decreases with the percentage of fibers, from 2.205 t/m3 for the concrete without fiber to 2.001 t/m3 for the concrete containing 0.8% of fibers. The thermal conductivity and thermal diffusivity also decrease with the percentage of fibers, they range respectively from 1.021 W/m.K to 0.448 W/m.K and from 5.64 10-7 m²/s to 2.19 10-7 m²/s. As for the thermal capacity, it is almost constant with 0.1% of fibers (1810 to 1800 kJ/m3.K) then increases progressively up to 2046 kJ/m3.K for 0.8% of fiber. These results show that the incorporation of fibres improves the thermal characteristics of concrete. The use of this material would provide better thermal conditions inside the buildings, and consequently the reduction of energy consumption.

Developmental genomics of limb malformations: Allelic series in association with gene dosage effects contribute to the clinical variability.

SummaryGenetic heterogeneity, reduced penetrance, and variable expressivity, the latter including asymmetric body axis plane presentations, have all been described in families with congenital limb malformations (CLMs). Interfamilial and intrafamilial heterogeneity highlight the complexity of the underlying genetic pathogenesis of these developmental anomalies. Family-based genomics by exome sequencing (ES) and rare variant analyses combined with whole-genome array-based comparative genomic hybridization were implemented to investigate 18 families with limb birth defects. Eleven of 18 (61%) families revealed explanatory variants, including 7 single-nucleotide variant alleles and 3 copy number variants (CNVs), at previously reported “disease trait associated loci”: BHLHA9, GLI3, HOXD cluster, HOXD13, NPR2, and WNT10B. Breakpoint junction analyses for all three CNV alleles revealed mutational signatures consistent with microhomology-mediated break-induced replication, a mechanism facilitated by Alu/Alu-mediated rearrangement. Homozygous duplication of BHLHA9 was observed in one Turkish kindred and represents a novel contributory genetic mechanism to Gollop-Wolfgang Complex (MIM: 228250), where triplication of the locus has been reported in one family from Japan (i.e., 4n = 2n + 2n versus 4n = 3n + 1n allelic configurations). Genes acting on limb patterning are sensitive to a gene dosage effect and are often associated with an allelic series. We extend an allele-specific gene dosage model to potentially assist, in an adjuvant way, interpretations of interconnections among an allelic series, clinical severity, and reduced penetrance of the BHLHA9-related CLM spectrum.

A wideband monopole antenna with diplexer and rectifier for simultaneous energy harvesting and data communication

A wideband coplanar waveguide fed monopole antenna with diplexer and rectifier for microwave wireless power transmission and communication is proposed. The antenna is comprised of an asymmetric ground plane with an open stub, a rectangular monopole, and a square loop with a gap at the bottom. A microstrip line diplexer is implemented by using stepped impedance resonator slots to split the signal without extra matching circuits. A microwave rectifier based on the voltage doubler topology is designed for wireless power transmission. The prototypes are fabricated, measured, and compared with the simulated results. Measured results demonstrate that the −10 dB impedance bandwidth (1.42 GHz) of the antenna reaches 69.6% (1.33–2.75 GHz), the diplexer minimum insertion losses ( S 21 $$ \left|{S}_{21}\right| $$ , S 31 $$ \left|{S}_{31}\right| $$ ) are 2.13 dB, 3.27 dB at pass band frequencies, the output isolation ( S 23 $$ \left|{S}_{23}\right| $$ ) better than 20 dB from 1 to 3 GHz, and the peak RF to DC conversion efficiency of a rectifier is 56%. The integration of the proposed antenna, diplexer, and rectifier novel configuration is suitable for simultaneous wireless power transmission and communication applications.

Circularly Polarized Waveguide Aperture Array Antenna With a Wide Axial Ratio Bandwidth

In this letter, we design a circularly polarized (CP) waveguide aperture antenna with a wide axial ratio bandwidth. The unit is composed of three waveguides with different rotation angles and width. The reflected and transmitted orthogonal electric fields are superimposed on the asymmetric plane of the rotating structure in each layer, which not only reduces energy reflection but also promotes the decomposition of the electric field with the same amplitude and the phase difference 90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> in different rotating waveguides. Finally, a CP electric field is formed on the antenna’s surface. The phase difference and amplitude difference of orthogonal electric field are approximately 90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> and less than 1.2 dB, respectively. In addition, the different width of the waveguide plays a role in impedance matching. A 2 × 2 array is fabricated and measured to verify the validity of the design. The measured results show good agreement with the simulation. Measured impedance bandwidth of 37.9% (27.5–40.4 GHz), axial ratio bandwidth of 41.2% (27–41 GHz), and a gain of 15.7 dBi at center frequency have been obtained.

Miniaturized Circularly Polarized UWB Antenna for Body Centric Communication

A compact body-worn circular polarized textile monopole antenna for wearable applications is reported. The proposed antenna is fabricated on a jean fabric providing flexibility, lightweight, and easy integration into human clothes. The overall size of the proposed antenna is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$25\times 30\times1.4$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . Circular polarization (CP) is advantageous for on-body communication as it provides features, such as multipath immunity, suppressing interferences, and enables better link connectivity between the sensor nodes. The proposed antenna achieves the CP using an asymmetric stepped L-shaped ground plane and through the incorporation of a cross-shaped stub in the radiator. The single-fed octagonal strip monopole antenna provides good impedance matching over the entire ultrawide frequency range from 3.09 to 11 GHz. Simulation results are in good correlation with the measured results. The axial ratio bandwidth <3 dB is achieved in the frequency range of 3.4–10 GHz. Gain and efficiency obtained are about 2.3-4.4 dBi and 65%–82% at the said frequency range, respectively. Structural deformation is performed to analyze the flexibility of the proposed antenna. The simulated SAR values follow the FCC limit making it most suitable for wearable applications.

Design of a co‐planar waveguide‐fed flexible ultra‐wideband ‐ multiple‐input multiple‐output antenna with dual band‐notched characteristics for wireless body area network

In this article, a co-planar waveguide-fed ultra-wideband (UWB) multiple-input multiple-output flexible antenna with dual band-notched characteristics on liquid crystal polymer substrate with high isolation for wireless body area network application is designed and fabricated. Two fan-shaped monopole UWB antenna elements are designed and placed vertically, with tampered feeder, asymmetrical ground plane and two C-shaped slots on the radiation patch. The measured working bandwidth can reach 2.63–11.6 GHz and the rejection bands are 3.25–4.36 and 5.41–6 GHz. The port isolation (S21) is better than −22 dB. When the bending radius is 35 and 45 mm, the antenna is measured for flexibility. In addition, the antenna is placed on human tissue to test its performance. All the results show that it has good radiation, high isolation and flexibility, and has broad application prospects in the wearable field.

Novel Broadband Circularly Polarized Monopole Antenna for Multi-communication Systems

This paper proposes a novel coplanar waveguide (CPW) fed broadband circularly polarized (CP) monopole antenna, which applies to C-band and various wireless communication systems. The antenna consists of the double circular-shaped patch (DCSP) with square and L-shaped slots, and an improved asymmetric ground plane. The prototype of the designed antenna has been fabricated. The results of the measurement show that the 10-dB impedance bandwidth (ZBW) is 117.8% (2.2–8.5 GHz), the 3-dB axial ratio bandwidth (ARBW) is 62% (4.45–8.45 GHz).

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

Anion-Responsive Manganese Porphyrin Facilitates Chloride Transport and Induces Immunogenic Cell Death

N-polar ScAlN and HEMTs grown by molecular beam epitaxy

Molecular beam epitaxy of single-phase wurtzite N-polar ScxAl1−xN (x ∼ 0.11–0.38) has been demonstrated on sapphire substrates by locking its lattice-polarity to the underlying N-polar GaN buffer. Coherent growth of lattice-matched Sc0.18Al0.82N on GaN has been confirmed by x-ray diffraction reciprocal space mapping of the asymmetric (105) plane, whereas lattice-mismatched, fully relaxed Sc0.11Al0.89N and Sc0.30Al0.70N epilayers exhibit a crack-free surface. The on-axis N-polar crystallographic orientation is unambiguously confirmed by wet chemical etching. High electron mobility transistors using N-polar Sc0.18Al0.82N as a barrier have been grown on sapphire substrates, which present the existence of well confined two-dimensional electron gas. A Hall mobility of ∼564 cm2/V s is measured for a 15-nm-thick Sc0.18Al0.82N barrier sample with a sheet electron concentration of 4.1 × 1013 cm−2, and the corresponding sheet resistance is as low as 271 Ω/sq. The polarity-controlled epitaxy of ScxAl1−xN provides promising opportunities for applications in high-frequency and high-power electronic and ferroelectric devices.

Optimization of Passive Transmission Lines for Single Flux Quantum Circuits

Passive transmission lines (PTLs) provide an energy-efficient means of transporting pulsed single flux quantum (SFQ) signals between logic gates and blocks on a chip, or even between chips through a multi-chip module carrier. Although functional up to 70 GHz, our previous designs manifested sharp, length-dependent resonances resulting in diminished operating margins. These are particularly inconvenient since the resonant length is about 1 mm at 40–50 GHz, where most SFQ circuits currently function. To avoid the need to keep the PTLs < 1 mm in length, we have optimized the PTL driver-receiver pairs to sufficiently suppress these resonances; this helps facilitate the use of automated routing tools. We present experimental results, in the 10-70 GHz frequency range, for different driver-receiver pairs designed for PTLs in our dual RSFQ-ERSFQ cell library. This cell library, targeting MIT Lincoln Laboratory's SFQ5ee fabrication process, uses PTLs with two types of ground plane configuration. The first variant has signal in M1 and/or M3 with symmetrical ground planes in M0, M2 and/or M2, M4 respectively. The second variant has signal in M2 and/or M3 with asymmetrical ground planes in M1 and M4. We also present a comparison with wider, 4 Ω, PTLs that are more suitable for transport between distant logic blocks. Next, we present experimental results of PTL lengths ranging from 1.2-12 mm over the same 10-70 GHz frequency range. Finally, we report on the design of circuits for investigating crosstalk between two PTLs and their measurement results.