Electromagnetically induced transparency (EIT) enables an otherwise opaque medium to become transparent and can dramatically slow or even temporarily store light pulses within the medium. It provides a robust platform for manipulating and preserving quantum optical signals, making it a powerful tool for quantum information processing and precision sensing. In this work, we demonstrate EIT on a fully integrated, chip-scale platform based on nanoscale atomic suspended waveguides (NASWAGs) surrounded by hot rubidium vapor. These structures provide submillimeter-scale interaction lengths and feature a tapered geometry that extends the optical mode into the surrounding vapor, increasing the atom-light interaction volume and reducing transit-time broadening. Combined with the strong spatial confinement of both probe and control beams, this enables efficient EIT with only a few microwatts of control power. This represents a significant advance over standard nanophotonic platforms, where weak evanescent fields and short interaction times have previously prevented the observation of EIT.

This study investigates the flexural behavior of RC beams strengthened with Basalt Textile Reinforced Mortar (BTRM), focusing on the influence of the number of textile layers, mesh size, and anchorage techniques. Six full-scale RC beams were tested under four-point bending, comprising one unstrengthened control specimen and five beams strengthened using different BTRM configurations. The experimental results demonstrated that increasing the number of BTRM layers from three to five enhanced the ultimate load capacity by up to 18% compared to the control beam. Nevertheless, debonding was identified as the predominant failure mode across most strengthened specimens. The influence of mesh size was examined by comparing an eight-layer specimen using 5mm mesh size with a three-layer specimen using 34mm mesh size; both configurations exhibited comparable flexural performance. Variations in mesh size (34 versus 5mm) had a negligible effect on load capacity. The incorporation of basalt bars resulted in a marginal improvement in flexural strength, whereas mechanical anchorage provided limited enhancement in overall performance. These findings highlight the critical need to improve bond behavior and anchorage efficiency in order to fully benefit from the strengthening potential of BTRM systems. In addition, an analytical study was conducted to assess the accuracy of existing predictive models, including those proposed in current design guidelines and previously published analytical approaches, against the experimental results. A modified predictive equation derived from an existing analytical model demonstrated good agreement with both the experimental data and results reported in the literature.

In this research, thirteen T-shaped hybrid concrete beams were designed to investigate their flexural behavior. Flanges of all beams were cast by 106 N/mm2 fcu of self-compacting high-strength concrete (SC-HSC), while the webs were made by 45 N/mm2 fcu of normal-strength concrete (NSC). One beam was loaded up to failure as a control beam (CB), and the other beams were divided into two groups; the first group consisted of six beams preloaded by 45% of CB's ultimate load (Pu), and the other group of beams subjected to 85% of CB's Pu. Beams were retrofitted along the entire clear span using various numbers and placements of glass fiber-reinforced polymer (GFRP) bars mounted near the bottoms and side(s) surfaces. However, tests resulted in a notable enhancement ranging from 35% to 101% of retrofitted beams. At the same time, the maximum deflections of both groups witnessed a range from 21.9 mm to 34.9 mm beside CB's ultimate deflection (33.8 mm); in addition, ductility ratio, toughness, and stiffness values varied between (55.89% and 73.8% reduction), (15.95% decrement and 31.96% increment), and (2.36% and 47.83% reduction), respectively. Furthermore, the failure mode was mainly GFRP-Epoxy debonding

This study investigates the flexural behavior and practical application of Reinforced Concrete (RC) beams strengthened with Ultra-High Performance Concrete (UHPC). Flexural tests were conducted on ten beam specimens to systematically analyze the effects of steel fiber dosage, reinforcement ratio, and beam height on the failure modes, load-bearing capacity, and deformation characteristics of the strengthened beams. The results were compared with those of unstrengthened control beams (CB). Experimental observations indicated excellent interfacial bonding between the UHPC layer and the RC beam, with no debonding failure occurred. All specimens exhibited typical under-reinforced flexural failure characteristics, and their load–deformation curves displayed three distinct stages. Compared to the control beams, the ultimate load-bearing capacities of the strengthened beams increased by 9.5–15.7% with varying steel fiber dosages, 16.4–110.2% with varying reinforcement ratios, and 6.2–518.8% with varying beam heights. Furthermore, the UHPC layer significantly enhanced the flexural stiffness of the beams. Although ductility was slightly reduced, all strengthened beams demonstrated clear yield characteristics prior to failure, avoiding brittle fracture. Additionally, nonlinear numerical simulations performed using MATLAB R2020a showed high agreement with the experimental results, verifying the accuracy of the analytical procedure. Based on the validated model, a parametric study was conducted to further investigate the influence of beam height, reinforcement ratio, and interface coefficients on flexural performance. The findings confirm the reliability and effectiveness of the UHPC strengthening technique.

Carbon fibre reinforced polymer (CFRP) sheets have a high strength to weight ratio and corrosion resistance, and consequently they have attracted much attention for flexurally strengthening deteriorated reinforced concrete (RC) beams. The study experimentally evaluated the flexural performance of RC beams strengthened with two types of CFRP materials carbon fibre fabric (CFF) and silicone coated carbon fibre laminates (SCCFL), under static cyclic loading (load-controlled). Three series of beam specimens were static cyclically loaded until significant damage including unstrengthened control beams and beams strengthened with single and double layers of CFF and SCCFL. As key parameters ultimate load capacity, the load deflection behaviour, the energy dissipation, crack propagation and stiffness degradation were evaluated. Results indicated that strengthening of the beam with CFRP increased the nominal flexural strength, and its fatigue resistance. The two materials used for strengthening exhibited different performance behaviour, among which the SCCFL strengthened beams exhibited higher load capacity and energy dissipation, less crack width and retained stiffness under static cyclic loading (load-controlled). SCCFL is proved to be more effective in retrofitting RC structure to dynamic or fatigue loadings.

ABSTRACT A broadband dual‐beam dual‐polarized antenna array having low sidelobe and controllable beam pointing is proposed. A crossed‐dipole antenna element with link lines is introduced to achieve excellent impedance matching, symmetrical and stable radiation pattern, low cross‐polarization level, as well as very steady gain at 1.7–2.7 GHz. Based on the element, a new staggered 2 × 2 subarray is proposed to achieve excellent sidelobe suppression over the wide operating band. Then a dual‐beam subarray, which consists of two staggered 2 × 2 subarrays and controllable metal fixtures, is designed to introduce dual‐beam performance with low sidelobe. The dual‐beam pointing can be easily controlled by tuning the metal fixtures. Finally, a dual‐beam dual‐polarized array is proposed to obtain high gain for practical application. It obtains a wide bandwidth of 45.5% (1.7–2.7 GHz) for reflection coefficient < −14 dB, and good isolation between all the ports larger than 21 dB. The array also has good dual‐beam performance, with sidelobe levels below −20 dB and beam‐pointing angles that can be varied to ±18°, ±28°, and ±38°.

Near-surface-mounted strengthening with polymer-based carbon fiber-reinforced polymer (CFRP) bars has been proved as one of the efficient techniques in enhancing the shear capacity of reinforced concrete RC deep beams. This paper presents an experimental investigation on the shear behavior of RC deep beams strengthened with NSM CFRP bars. Five identical RC deep beam specimens with the same geometry and internal steel reinforcement were tested under two-point loading. One specimen was left un-strengthened as a control beam; while four specimens have been strengthened by CFRP bars embedded in the shear zone with two orientations, 0°/90° and 45°/135°, and two spacing configurations, 100 and 150 mm. Response parameters of prime interest included first shear cracking load, ultimate shear capacity, crack pattern, and mid-span deflection. The findings of the experiment demonstrated that NSM CFRP strengthening improved the shear performance of deep beams; depending on the orientation and spacing of the CFRP bars, shear capacity augmentation ranged from about 14% to 47% in comparison to the control specimen. Additionally, at similar load levels, strengthened beams demonstrated a 10% to 40% decrease in mid-span deflections and fracture widths. The test results demonstrate how well polymer-based CFRP bars inserted using the NSM technology improve the stiffness and shear strength of RC deep beams.

Abstract Among smart materials, Liquid Crystalline Elastomers (LCEs) combine programmable well‐defined deformations with wireless control. To date, the successful fabrication of LCEs through 3D printing techniques, such as direct ink writing (DIW), requires precise control over the ink formulation, mesogen alignment, and curing processes, to get devices with uniform molecular orientations, and with optimized actuation performance. Here, we present a simple synthetic approach leading to a ten‐of‐gram‐scale ink production suitable for low‐cost DIW 3D printing of LCEs. The novel ink, containing a push‐pull azobenzene directly linked to the polymer backbone, enabled 4D printing of fast responsive photo‐mechanical actuators with programmable and reversible deformation. Our centimeter‐scale LCE structures present active tensions twitches comparable to those of cardiac muscles, both in terms of magnitude (kPa range) and timescale (tens to hundreds of milliseconds). An all‐round actuation characterization is also developed and reported. As a proof‐of‐concept demonstrator, an optical beam steerer was developed demonstrating a high control of the beam diffraction angle as a function of the control beam light power.

Electromagnetically induced transparency (EIT) provides an effective platform for coherent control of optical responses in atomic media. Here, we investigate a microwave-assisted closed-loop three-level system driven by a Laguerre-Gaussian (LG) control beam and a Gaussian probe field. Unlike previous work such as O. N. Verma and N. Kant, All-optical generation of structured light beams via microwave-field-controlled electromagnetically induced transparency, Phys. Rev. A, 2024, 110(1), 013701, which focused on overall optical gain in open-loop configurations, our study examines how structured light modulates the spatial distribution of Raman gain. Using a density-matrix approach, we numerically obtain two-dimensional maps and cross-sectional profiles of Raman gain. The results show that three parameters-the orbital angular momentum (OAM) of the LG beam, the single-photon detuning, and the relative phase of the control fields-collectively determine the spatial morphology of the gain. OAM controls the transition between single-lobe and multi-lobe structures, modulates the gain magnitude and spatial complexity, and the relative phase induces rotational or mirror-symmetric transformations. This work provides the first systematic analysis of spatial Raman-gain modulation in a closed-loop three-level system, demonstrating the strong capability of structured light to tailor nonlinear gain processes. The findings extend the theoretical framework beyond PRA 2024 and offer insights for spatially selective amplification and structured-light-based photonic device design.

Glued laminated timber (glulam) is increasingly adopted as a sustainable structural material; however, its performance under bending can be limited by brittle tensile failures and variability caused by natural defects. This study examines the flexural behavior of glulam beams strengthened with externally bonded carbon fiber reinforced polymer (CFRP) sheets. A four-point bending experimental program was carried out on glulam beams with varying CFRP bonded lengths, including unreinforced control beams. The results demonstrate that CFRP reinforcement enhanced load–carrying capacity by up to 48%, increased stiffness, and shifted failure modes from brittle tension–side ruptures to more favorable compression–controlled mechanisms. A nonlinear finite element (FE) model was developed using DIANA software 10.5 to simulate the structural response of both unreinforced and CFRP–strengthened beams. The numerical model accurately reproduced the experimental load–deflection behavior, stress redistribution, and failure trends, with deviations in ultimate load prediction generally within ±16% across all reinforcement configurations. The simulations further revealed the critical influence of CFRP bonded length on stress transfer efficiency and failure mode transition, mimicking experimental observations. By integrating experimental findings with numerical simulations and simplified analytical predictions, the study demonstrates that reinforcement length and bond activation govern the effectiveness of CFRP strengthening. The proposed combined methodology provides a reliable framework for evaluating and designing CFRP strengthened glulam beams.

ABSTRACT Terahertz (THz) waves hold great promise for next‐generation wireless communication, radar imaging, and biomedical diagnostics. However, conventional metasurface‐based THz modulators are typically static and single‐functional, limiting their adaptability to diverse operational scenarios. Here, we present a modular design strategy based on spin‐decoupled metasurfaces to achieve switchable and multifunctional THz wave manipulation. This approach integrates spin‐selective phase control with mechanically reconfigurable module layouts—either planar arrangement or directional cascading—to flexibly switch and combine multiple functionalities without the need for active materials or complex redesign procedures. As a proof of concept, two identical metasurface modules are fabricated using low‐cost, high‐throughput 3D printing and experimentally validated to demonstrate versatile beam control, including dual‐focus and nondiffracting beam generation, power‐tunable dual‐focus scanning, and near‐field focal scanning to far‐field beam steering. Functional switching is readily achieved by either adjusting the incident spin state or reconfiguring the module arrangement. Moreover, the modular strategy is inherently scalable to higher frequencies or more modules, enabling further expansion of functionality and tunability. This work establishes a general, fabrication‐friendly platform for compact, multifunctional THz photonic systems, offering broad prospects for 6G communication, intelligent sensing, and integrated THz architectures.

The repair and rehabilitation of deteriorating reinforced concrete (RC) structures have become increasingly important due to factors such as environmental degradation, aging, poor construction materials and workmanship, increased service loads, and the need for seismic retrofitting. Among various strengthening techniques, Fibre Reinforced Polymers (FRP) have emerged as an effective solution because of their high strength-to-weight ratio, corrosion resistance, and ease of installation.Previous studies on torsional strengthening have primarily concentrated on solid rectangular RC beams with different fibre types and wrapping configurations. Several analytical models have been developed and validated experimentally for predicting the torsional behavior of such beams. However, limited research has focused on the torsional strengthening of flanged RC T-beams, where the contribution of the flange to torsional resistance is often neglected in design codes. The present study aims to experimentally investigate the torsional behavior of solid RC flanged (T-section) beams strengthened using externally bonded Glass Fibre Reinforced Polymer (GFRP) fabrics. The influence of flange width, strengthening configurations, and fibre orientations on the torsional performance of beams was examined. Control beams without FRP were tested to compare their performance with GFRP-strengthened specimens

Abstract We describe a monolithic interferometer for spatial coherence measurements of both classical and quantum light sources. The design enables measurements on both a PDC-based quantum source and a classical thermal source, using two identical calcite crystals to control beam alignment via birefringence. The monolithic structure ensures inherent stability. Spatial coherence is measured through temporal interferograms and spectral analysis, with both methods showing close agreement with theoretical predictions. The system is robust and performs reliably for both quantum and classical light. Its design enables automated, rapid coherence measurements across different source types.

This paper presents the results of a study that aimed to analyze the flexural behavior of self-compacting rubberized steel-reinforced concrete. A four-point bending test was performed on three reinforced beams made with conventional concrete and three similar beams made using the same concrete mixture with a 10% volumetric substitution of natural aggregates with rubber particles. The results showed a statistically significant decrease (about 24%) in the cracking load for the rubberized concrete beams, which is attributed to the reduced indirect tensile strength and modulus of the rubberized concrete. However, no statistically significant difference was observed between the control and rubberized concrete beams in terms of ultimate load and maximum deflection Additionally, the estimated adhesion strength, based on the average measured crack spacing, was also statistically similar between the tested beams. Existing equations derived from reinforced concrete beam theory were deemed suitable for rubberized concrete, since the estimation trends for these equations were similar for both types of concrete. Therefore, the main conclusion of this study is that the presence of rubber particles, at a 10% volumetric substitution, did not affect the flexural behavior particularly the quality of adhesion between the reinforcing bars and the surrounding concrete of steel-reinforced beams.

The phase shift of an optical beam in free space due to the formation of a crystal structure in controlled elementary cells based on thin films of phase-change materials Ge 2 Sb 2 Se 4 Te, Sb 2 Se 3 , and Bi 2 Se 3 under the control effect of pulsed laser radiation has been experimentally studied. The change in the phase of the studied optical beam passing through a controlled cell of phase-changing material relative to the control beam in a Jamin interferometer has been demonstrated. The phase shift has been estimated using analytical expressions.

Reinforced concrete (RC) structures often need shear retrofit due to factors like design deficiencies, aging, or increased loads. This study explores an innovative hybrid retrofit system for RC beams with shear defects, using an external jacket composed of strain-hardening cementitious composites (SHCC) and welded steel mesh (WSM). An experimental program including nine RC beams, involving control, defected, and strengthened specimens, was prepared to assess the effectiveness of many jacket arrangements (one-sided, two-sided, U-wrapped, and fully wrapped) and the influence of mechanical anchorage. In addition, the experimental work was simulated using Abaqus program to replicate the beams’ behavior. Experimental findings showed that the shear defect significantly reduced load capacity, stiffness, and energy absorption. All strengthening configurations improved performance, with effectiveness generally increasing from one-sided to full wrapping. Anchorage bolts enhanced load capacity and energy absorption, particularly for partial jackets and U-wraps. Particularly, the fully wrapped configuration restored the beam’s ultimate load capacity nearly to the level of the control beam, even without anchorage, and significantly enlarged absorbed energy. The FE model accurately simulated the experimental failure modes, crack patterns, and load-displacement responses, validating its reliability. Full jacketing with anchorage improved the ultimate load capacity by up to 75% compared to unstrengthened beams. Crack propagation was considerably delayed, and average crack widths were reduced by 30–35%. Moreover, the retrofitted beams exhibited a remarkable increase in energy absorption capacity, achieving up to 3.8 times the energy dissipation of the control specimens. These findings clearly demonstrate the necessity and effectiveness of the proposed retrofit system for extending the service life and resilience of RC beams.

Reinforced concrete (RC) joist slabs are common in Middle Eastern buildings, where architectural needs often necessitate planting columns on shallow beams. Although such beams typically satisfy flexural and shear design requirements, their serviceability is frequently compromised by excessive deflections. This study experimentally investigated the effectiveness of polymer-bonded/bolted steel plates versus an Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) overlay, applied to the compression face, in controlling the deflection of shallow beams with planted columns. Four half-scale beams were tested under single-point loading, including two unstrengthened specimens to be used as reference beams. The first control beam reflected typical design practice—adequate in strength but exceeding code deflection limits—while the second specimen was designed to achieve similar flexural capacity with serviceable deflection. The remaining two beams were externally strengthened using either steel plates or UHPFRC overlay. Experimental results were analyzed in terms of failure mode, peak load, and deflection response. Both strengthening methods improved bending performance, stiffness, and load capacity, with UHPFRC showing superior effectiveness. Simplified analytical equations provided reasonable predictions of deflection and ultimate load. The findings highlight the potential of compression-side strengthening, particularly using UHPFRC, to enhance the serviceability of shallow RC beams supporting planted columns.

The distinctive characteristics of light, such as high-speed and low-loss propagation, low crosstalk and low power consumption, along with the unique quantum properties of photons, make it most suitable for various applications in communications, high-resolution imaging, optical computing and quantum information technologies. One limiting factor, however, is the weak optical nonlinearity of conventional media, which poses challenges for controlling light at ultralow intensities. Here we demonstrate all-optical modulation of the refractive index enabled by the electron avalanche process in silicon using a control beam with single-photon light intensities. The observed process corresponds to an extremely high nonlinear refractive index of , which is several orders of magnitude higher than those of the best-known nonlinear optical materials. Using single photons for light modulation opens the possibility of gigahertz-frequency-and potentially even faster-optical switching for on-chip photonic and quantum devices operating at room temperature.

Abstract Field‐cast ultra‐high performance concrete (UHPC) overlays reinforced with fiber reinforced polymer (FRP) bars have been evaluated for retrofitting reinforced concrete (RC) structures, but limitations exist such as the complexity of UHPC mixing and the need for specialized equipment. To mitigate these limitations, prefabricated overlays can be used as an alternative, bonded to the member soffit by mechanical or adhesive means. In this study, experimental, numerical, and analytical investigations were carried out to evaluate the effectiveness of prefabricated FRP‐reinforced UHPC overlays for strengthening RC members in flexure. Eight beams were tested under monotonic load, including two control and six strengthened samples. The studied parameters were the (a) overlay casting type (prefabricated vs. field‐cast), (b) reinforcing the overlay with glass‐FRP (GFRP) bars, and (c) attachment of the prefabricated overlays, using either adhesive bond only or in combination with mechanical anchorage. The increase in the ultimate load ( P u ) in strengthened specimens over the control beam was 30%–265%. Reinforcing the overlay with GFRP bars was highly effective, leading to a 67%–200% increase in P u over plain layers, good ductility, and minimizing localized cracking in the overlay. Prefabricated overlays behaved in a similar fashion compared to the cast‐in‐place peers and were in some cases superior in terms of P u and ductility. While adhesively bonded overlays showed good bond, mechanically anchored counterparts were prone to drilling damage. A validated three‐dimensional finite element model was used in a parametric study on the effects of GFRP reinforcement ratio, overlay reinforcing bar type (steel, GFRP, carbon‐FRP (CFRP)), and compressive strength of the RC beam. An analytical model is also presented to estimate the load capacity of the strengthened beams.

Abstract The purpose of this study is to experimentally investigate the impact of alternative shear reinforcement systems on the shear performance of deep beams. Additionally, the research aims to determine the optimal distribution of concrete types in hybrid deep beams to minimize cost and weight while maintaining structural capacity without significant loss. Five beam specimens were cast and divided into two groups. The first group, serving as the control, consisted of two beams: one made of normal-strength concrete and the other of high-strength concrete, both with identical reinforcement details. The second group included three hybrid beams composed of normal- and high-strength concrete, arranged in an arch-shaped hybrid configuration. Angle steel sections (40×40×4 mm) were employed as an alternative to conventional strut reinforcement. All beams shared the same dimensions: 1200 mm in length, 500 mm in depth, and 150 mm in width. The tests were conducted using a single-point loading setup with a constant shear span-to-effective depth ratio (a/d = 1). Compared to the first control beam (normal-strength concrete), the hybrid specimens in the second group exhibited improvements in load-carrying capacity by 40%, 23.3%, and 80%, respectively. Stiffness increased by 54.08%, −15.52%, and 69.76%, while toughness improved by 83.3%, 103.68%, and 215.6%, respectively. In comparison with the second control beam (high-strength concrete), the same hybrid specimens showed increases in load capacity of 7.7%, −5.13%, and 38.46%, respectively. Stiffness improved by 16%, −36.4%, and 27.8%, while toughness increased by 7.3%, 19.93%, and 85.84%, respectively.