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• Extended reality fosters artists, curators to frame and contextualize exhibitions. • Extended reality allow new conceptualizations of exhibiting art. • Ways of presenting art through extended reality can form a continuum with exhibits. • Extended reality exhibitions interrelate media design, aims/scope and content. This manuscript addresses the increasing importance of Extended Reality (XR) in art exhibitions. It elaborates on the technologies employed, design issues, pertinent aims, and evaluation metrics. The main research questions concern the types of technologies currently used, the primary design considerations, and the ways user experience can be enhanced in accordance with the artists' and curators' vision, as well as visitors' needs. Moreover, the paper also examines relevant evaluation criteria. The manuscript reviews the types of technologies used for virtual art exhibitions and examines their design characteristics and pertinent issues on interfaces, resources, and affordances. Furthermore, an analysis of the use of virtual humans as a model for increased engagement follows a discussion of a comparison between virtual versus physical exhibitions. Moreover, the parameters that affect user experience are discussed thoroughly, given their pivotal importance in such exhibitions. Finally, the paper concludes with a discussion of the above-mentioned aspects of XR exhibitions with an emphasis on optimizing design for art-related content and offering informed suggestions for future directions. The overall scope of this paper is to examine ways to exploit XR as a creative medium rather than merely replicate physical exhibitions. In this context, the papers' discussion includes the Metaverse. [ABSTRACT FROM AUTHOR]

This investigation analyses the 3D performance of two optimal front wing designs according to the Federation Internationale de l'Automobile 2021 regulations. These regulations imply a 3D five-element front wing, with ground effect and more than 30 design parameters and geometry constrains in practice, which has not been studied before in the literature. The two optimal front wing designs were obtained by parametric optimisation with sampled Kriging interpolation surrogates and a posteriori adjoint-based design refinement. The optimal front wings have been tested on 3D Computational Fluid Dynamic simulations to analyse the generated downforce and flow interaction with the front wheels and brake ducts, as well as the reproduction of influential vortices. Although the parametric design achieved a slightly better downforce-to-drag ratio, the adjoint-based design exhibited a greater ground suction effect, lower pressure distribution on the tire treads, and some deviation of the Y250 vortices to the wheel, which affected the flow over the wheel&brake ducts. This work demonstrated that quick improvements can be achieved starting from 2D analysis and running 3D simulations of relevant parts of the car, which is unaffordable to date for direct 3D simulation in a design space reduced to 17 dimensions and constrained by regulations. [ABSTRACT FROM AUTHOR]

This paper proposed a dynamic current-enhancement technique based on AC coupling network and feedforward compensation capacitor for current-feedback low-dropout regulators (LDOs). Compared with traditional reported current-feedback LDOs, this design exhibits wider input voltage range, greater load capacity and fast transient response, yet no extra power consumption is introduced. Moreover, a complete stability analysis under full load range is given in this paper. The proposed LDO is fabricated in SMIC 0. 18 μ m CMOS process. The input voltage range is 0.8–2.2 V and the maximum load current is 50 mA. The experiment results indicate that the overshoot and undershoot are 76 mV and 141 mV respectively when the load current is varied from 0 to 50 mA within 300 ns under the load of 100 pF load capacitor. • This paper proposed a dynamic current-enhancement technique for current-feedback lowdropout regulators. It significantly reduces the overshoot and undershoot and improves large signal transient response. More importantly, it is not implemented at the expense of more quiescent current. [ABSTRACT FROM AUTHOR]

• Hybrid models struggle for prediction of dimensional-interaction, a problem rarely tackled in the literature so far. • Sampling strategies for the exploration of anisotropic design-space with very few evaluations. • A fast derivatives computation approach through the sensitivity method, largely reducing computational cost. • A second-order derivative enhanced Taylor-Cokriging unified model proposed for anisotropic design-space exploration. Anisotropy occurs naturally when modelling engineering design spaces and sometimes becomes significant, such as in robust and reliability-based design optimization, where the "noise factor" is often modeled in a different way with the design variables. Hybrid models are often used to handle the anisotropy by using different methods for different types of variables. However, since different models are used, the dimensional interactions cannot be accurately approximated, and the intensive computational cost remains high due to the number of samples needed. This work presents a novel method to tackle this anisotropic design space with a proposed Hessian-enhanced Taylor–cokriging unified model. First, the sampling strategies for the exploration of anisotropic design spaces is presented. Second, the difficulty of modelling with anisotropic design spaces is analyzed. Third, a solution is proposed by introducing additional assumptions of the probability distribution into the modelling process. Furthermore, to reduce the computational cost, the sensitivity method is integrated into the methodology to obtain low-cost derivatives. Finally, the proposed method is assessed for the specific case where only a single sample value exists in certain dimensions. The elementary effect is adopted to quantify the dimensional properties. Three test cases, including two theoretical ones and an industrial one, are used to assess the validity of this method. The first theoretical test case calls for a massive number of multimodal two-dimensional test functions whose spatial properties in each dimension are distinctive. The second theoretical test case uses a ten-dimensional test function. Design optimization is performed for an automotive engine cooling fan whose design space exhibits anisotropic properties. The model built with the proposed Taylor–cokriging method attains a good accuracy. This study is meaningful for the large-scale robust design and reliability-based design optimizations whose design spaces are likely to show anisotropic properties. [ABSTRACT FROM AUTHOR]

Traditional asphalt mix design methods primarily rely on experience, consuming immense time and resources. Currently, advanced machine learning (ML) method can accelerate the asphalt mix design procedure. However, historical data on asphalt mix design exhibit high variability, and the outputs of ML models are often challenging to interpret. To address these issues, this study selectively utilized outlier detection algorithms for data preprocessing and employed interpretable ML to predict and explain the volumetric properties of the mixtures, achieving an automated and rapid mix design method. A database (1525 sets of data) of volumetric properties was established based on experimental data of the engineering site. Z -score, KDE (kernel density estimation) and LOF (local outlier factor) methods were employed to detect outliers of the database. Three ML models were trained to predict the volumetric properties of mixture (air void and voids in mineral aggregate), based on material proportion, gradation morphological and material performance features. The SHAP method was used to interpret the extreme gradient boosting (XGB) model, quantifying feature importance, and aiding in decision-making. Finally, an asphalt mix design framework was proposed. The results indicate that the combination of KDE and LOF methods for outlier detection enabled the machine learning model to achieve optimal performance. The XGB model had the best prediction effect on volumetric properties. According to the SHAP method results, the influence of the critical features on the results was explained by the physical laws. The method proposed effectively reducing the design time and costs. The feasibility of the proposed design method was proved by the case study. [Display omitted] • Combining kernel density estimation and local outlier factor for outlier detection. • SHAP method was used to explain the XGB model. • The influence of critical features on the volumetric properties was determined. • The proposed asphalt mix design method can reduce the design procedure by 70%. [ABSTRACT FROM AUTHOR]

• A 'directional damping' concept is proposed for viscoelastic composite design. • A topology optimization model is developed for directional damping composites. • Optimized directional damping designs notably outperform the isotropic designs. • Optimized microstructures show similarities with bio-inspired wavy design. • Potential application of directional damping is shown by an airless tire design. Design of architected functional materials that possess desired damping performance is a topic of great interest in both academic research and industrial applications. This study investigates the concept of 'directional damping' for viscoelastic composites and develops a topology optimization framework to achieve directional damping design. Microstructures with both load-bearing capacity and dominant damping in the prescribed direction are obtained by maximizing the loss factor while imposing stiffness constraints. An optimized directional damping microstructure design exhibits a loss factor 1.8 times higher than the isotropic design in the prescribed direction. It is found that the optimized configurations with curved viscoelastic strips are similar to wavy 'suture' lines in the beaks of woodpeckers, which possess outstanding energy absorption performance. We have also verified the superiority of the directional damping design through numerical simulations and experiments of the microstructured composites. The experiment results show significant reduction of peak response for the directional damping design compared to the isotropic counterpart. To demonstrate the application potential of the optimized unit cell microstructures, a novel conceptual airless tire that exhibits improved stiffness and shock absorption performance is designed and validated through both numerical simulations and experiments. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the influence of the corrosion performance of weathering high-strength bolt connections was investigated based on the periodic immersion accelerated corrosion tests. Weathering steel high-strength bolt connections were performed by periodic immersion accelerated corrosion tests and tensile tests. The macromorphology, micromorphology, corrosion products and mechanical properties were analysed and compared with ordinary carbon steel high-strength bolt connections under the same corrosion conditions. The results showed that the weathering steel exhibited slightly stronger corrosion resistance, and a conversion relationship between atmospheric corrosion time and periodic immersion-accelerated corrosion time was proposed. The slippage load of the weathering steel high-strength bolt connections fist decreased, then increased, and finally stablilized under corrosion damage conditions, in which the change trend was different from that of the carbon steel. The maximum reduction in the corroded weathering steel high-strength bolt connection with corroded and new bolts reached 16.9% and 12.3%, respectively, which no longer met the design requirements and exhibited certain safety hazards. However, when spraying zinc on the friction surfaces of the weathering steel high-strength bolt connections, the slippage load variation ranges of the connections remained within 10% throughout the corrosion period, with a stable trend and high reliability. The antislippage coefficient of the weathering steel high-strength bolt connection surface with spraying zinc was more stable than the sand-blasting treatment, and the zinc spraying treatment method exhibited excellent anticorrosion ability. Based on the variation laws, a formula was proposed for the change in the antislippage coefficient with corrosion time. • The study investigates the corrosion resistance of weathering steel, and the conversion relationship between atmospheric corrosion time and immersion corrosion time of weathering steel is given. • The study investigates that the weathering sand-blasting friction surface exhibits higher density and stability than the rust layer formed in the later stage of ordinary carbon steel. • The study investigates that the slippage load of weathering steel friction surface sand-blasting connectors decreased significantly with the slippage load variation of the connectors sprayed with inorganic zinc rich within 10%. • The study proposes a formula for the relationship between antislippage coefficient and corrosion time is proposed. [ABSTRACT FROM AUTHOR]

Designing surface-enhanced Raman scattering (SERS) substrates that combine multiple advanced features in synergy is highly desirable for the SERS technique, however, it has been a long-standing challenge due to inherent trade-offs in feature selection. For instance, while nanoplasmonic surface functionalization bolsters attraction to target analytes, it simultaneously introduces barriers to direct contact. Similarly, the intrinsic hydrophilic or hydrophobic nature of substrates often limits their sensing effectiveness across a wide range of analyte types. Here, we demonstrate a smart 3D Ag-decorated TiO 2 nanostructure, an advanced synergistic SERS substrate, created by controlling the formation of Ag nanoparticles on functionalized TiO 2 nanomaterials, which integrates four unique features: uniform hotspot distribution, efficient analyte trapping, accessible plasmonic surfaces, and dual-phase detection. This design brings unachieved sensor efficiency across a diverse array of analytes with varying sizes and hydrophobicity. Moreover, our design exhibits a novel dual-phase detection capability within mixtures of hydrophilic and hydrophobic analytes. As a proof-of-concept, our results highlight the potential of designing SERS substrates with multiple advanced features that work synergistically, enabling trace detection of a broader range of analyte types in various environments. More broadly, we anticipate that this work paves the way for the development of other nanomaterials that are capable of attracting diverse molecules while retaining key features such as accessible plasmonic surfaces and wide-area ordered hotspot distribution. Such nanomaterials could be powerful for advanced applications in hotspot engineering, surface analysis, catalysis, and plasmon-mediated reactions. [Display omitted] • Smart 3D Ag-decorated TiO 2 nanostructure, an advanced synergistic SERS substrate, has been successfully fabricated. • Integrating multiple unique features, this structure overcomes inherent trade-offs in feature selection during fabrication. • This substrate demonstrates exceptional detection efficiency for diverse analytes with varying natural properties. • The SERS substrate exhibits a novel dual-phase detection capability within mixtures of hydrophilic and hydrophobic analytes. [ABSTRACT FROM AUTHOR]

To increase cooling effectiveness, film-hole designs with serrated trenches have been widely reported in the gas turbine industry. However, the unsteadiness level of the film coverage and the inevitable environmental pulsation are always neglected, which may lead to an unexpected failure of hot components by the instantaneous exposure to a high-temperature environment. In this work, a series of large eddy simulations are conducted to comprehensively evaluate the transient film cooling performance with serrated trench designs, and the effect of pulsed cooling air injection is discussed. Time-averaged results reveal that: 1) under steady condition, serrated trench design exhibits a higher film effectiveness in most regions compared to the traditional transverse trench, which supports the previously reported advantage. 2) Pulsed cooling air injection would cause a significant reduction of film effectiveness for the serrated trenches. Under the pulsed condition, film effectiveness with a serrated angle of 100° can be over 20% lower than that with a traditional transverse trench. Moreover, transient results indicate that under both steady and pulsed conditions, the serrated trenches always exhibit a lower steadiness level of film cooling, relative to the traditional transverse trench. Therefore, it should be prudent to suggest film cooling with serrated trenches in practical designs. • LES is performed to study the transient film cooling behaviors with serrated trench. • The serrated trench design can increase film effectiveness under steady condition. • Film effectiveness of serrated trench is seriously decreased under pulsed condition. • The serrated trench design also causes a higher unsteadiness level of film cooling. [ABSTRACT FROM AUTHOR]

Deposition on heat exchange surfaces is an urgent problem to be solved to achieve efficient utilization of energy in thermal equipment. To mitigate deposition and the resultant heat attenuation, this work proposes a mixed tube bundle strategy of inserting attached cylinders behind the tube bundle, which can effectively meet the design requirements of high anti-deposition performance, high heat transfer efficiency, and low flow resistance. An integrated dynamic model for deposition is developed to elucidate the effect of ash particles on deposition, flow, and heat transfer characteristics. Based on the inverse distance weighting interpolation, a dynamic mesh smoothing technique is employed to simulate the evolving deposition layer on the heat transfer surface. In addition, the L 16 (43) orthogonal experimental design method is adopted to study the influence of the arrangement angle, diameter, and distance to the primary bundle of the attached cylinder on the overall performance, and determine the optimal scheme. The results show that deposition in the cases using the mixed tube bundle strategy has significantly decreased. The weakening effects of the attached cylinder on the deposition of small-medium particles and large-sized particles are due to the inhibition of vortex development in the gap of tube bundle and the deviation of the motion trajectory, respectively. The novel design exhibits the lowest deposition mass M dep = 1.12 g and the best comprehensive performance PEC = 1.14 under the condition of the arrangement angle of 50°, the diameter of 10 mm, and the distance between the primary bundle of 5 mm. The obtained results can provide reference schemes and guidance for the optimization of the design of heat exchange equipment and accessory devices. [Display omitted] • A mixed tube bundle strategy is proposed to improve anti-deposition. • An integrated dynamic deposition model is developed. • Orthogonal experimental design method is adopted to determine the optimization scheme. • Influencing factors of multiple optimization indicators are analyzed. [ABSTRACT FROM AUTHOR]

This study introduces a novel multi-band, polarization-insensitive metamaterial absorber, designed by combining a dual-band and a triple-band resonator structures. Through the amalgamation of discrete absorption responses from these structures, the resulting design exhibits five absorption peaks at frequencies: 1.5 GHz (80%), 3.6 GHz (88%), 5.46 GHz (95%), 7.17 GHz (95%), and 9.17 GHz (95%). One of the standout features of the proposed design lies in its four-fold symmetry, endowing it with polarization insensitivity. This ensures robust performance regardless of the incident polarization, enhancing the versatility and applicability of the absorber in various scenarios. The design's compact nature is noteworthy, with a unit cell dimension of only 0. 125 λ. This compactness not only contributes to space-efficient deployment but also underscores the efficiency of the metamaterial in achieving multiple absorption peaks within a limited spatial footprint. In addition to its compactness, the absorber is ultra-thin, with a dielectric thickness of merely 0. 008 λ. This characteristic is particularly advantageous for applications where a low-profile and lightweight solution is essential, such as in the development of inconspicuous communication devices or electromagnetic shielding. [ABSTRACT FROM AUTHOR]

• An efficient strategy to produce high-concentration H 2 O 2 is developed. • Photocatalytic activity of CTFs is tuned with thiourea groups and carbon dots. • H 2 O 2 concentration reaches 105.2 mM for per gram photocatalyst in 1 h. • Our presented strategy exhibits more superior activities in pollutant degradation. We here report an energy-saving and cost-effective strategy to produce high-concentration H 2 O 2 in commercial sponge with aqueous storage functions. Thereinto, the rationally designed hybrid consisting of thiourea-group-grafted covalent triazine frameworks (CTFs) and carbon dots (CDs) uniformly wraps the skeletons of the porous sponge to serve as photocatalytic system. This system allows solar radiation to be localized at the surface of photocatalyst and meantime suppresses the tremendous energy consumption of evaporation significantly by a simple seal way, thus giving rise to the required reaction temperature. With it, not only solar-converted heat as by-product in photocatalysis is fully utilized in H 2 O 2 production, but also high-concentration H 2 O 2 solution (105.2 mM for per gram photocatalyst in 1 h) is gained due to catalysis confinement effect. For application, our presented design exhibits more superior activities in degrading different organic pollutants (such as Rhodamine B, phenols and tetracycline) than conventional particulate photocatalysis thanks to in situ formation of concentrated H 2 O 2 in sponge. [ABSTRACT FROM AUTHOR]

• A very simple but versatile design motif, i.e., bq-structure, can provide sufficient flexibility in achieving various nonlinear properties. • The design motif has sufficient reliability in nonlinear manipulation with desired controllable & guided nonlinearities instead of "trail-and-error attempts" existing in most existing ones. • The design motif exhibits rich nonlinear properties including 200% lager and designable ranges of quasi-zero stiffness, negative stiffness, and multi-stable stiffness, etc. • The design motif based vibration isolation unit can achieve around 0.7 Hz resonant frequency easily, not achievable with many other literature ones. • The method also offers significant easiness in implementation, manufacturing and in-situ adjustability with very lost cost using additive manufacturing. Structure design motifs take an essential role in creating materials or metamaterials with superior mechanics or special functions. However, a fundamental question naturally arising and remaining unknown is related to how to effectively design an engineered material structure with "adjustable and predictable" nonlinear mechanic properties conveniently. Here we propose a very simple but versatile design motif, named as bq-structure, which can provide superior flexibility in achieving various nonlinear properties, including 200 % larger and designable ranges of quasi-zero stiffness, negative stiffness, and multi-stable stiffness, etc, that original material or traditional beam-based design motifs cannot provide. The proposed design motif has sufficient reliability in nonlinear manipulation with a "guided & controllable" manner instead of "trail-and-error attempts" existing in most existing ones. A prototyped vibration isolation unit can achieve a resonant frequency less than 1 Hz easily which cannot be done with many other methods of similar size and payload. Given the large elastic deforming capacity and ductility in structural scale, the superb nonlinearity regime is generally designable with various structure parameters, uniquely providing a superior optimization tool with this novel design motif considering various real application requirements for advanced materials design, energy storage or conversion, mechanical vibration mitigation, and robotic systems etc. [ABSTRACT FROM AUTHOR]

Helium turbines are widely used in the Closed Brayton Cycle for power generation and aerospace applications. The primary concerns of designing highly loaded helium turbines include choosing between conventional and contra-rotating designs and the guidelines for selecting design parameters. A loss model serving as an evaluation means is the key to addressing this issue. Because of the property disparities between helium and air, turbines utilizing as working fluid experience distinct loss mechanisms. Consequently, directly applying gas turbine experience to the design of helium turbines leads to inherent inaccuracies. A helium turbine loss model is developed by combining knowledge transfer and the Neural Network method to accurately predict performance at design and off-design points. By utilizing the loss model, design parameter selection guidelines for helium turbines are obtained. A comparative analysis is conducted of conventional and contra-rotating helium turbine designs. Results show that the prediction errors of the loss model are below 0.5 % at over 90 % of test samples, surpassing the accuracy achieved by the gas turbine loss model. Design parameter selection guidelines for helium turbines differ significantly from those based on gas turbine experience. The contra-rotating helium turbine design exhibits advantages in size, weight, and aerodynamic performance. • A helium turbine loss model is built using knowledge transfer and Neural Network. • The error of the loss model is below 0.5 % at over 90 % of test samples. • Design parameter selection guidelines for helium turbines are proposed. • Conventional and contra-rotating helium turbine comparison is performed. [ABSTRACT FROM AUTHOR]

This paper presents a novel framework for topology optimization (TO) of structures subjected to uncertain transient loading. Random transient uncertain but bounded loading is modeled in the form of an ellipsoid convex model. A transformation matrix is defined with uncertainty in input parameters based on orientation and lengths of semi-major and semi-minor axes of the ellipsoid. Latin hypercube sampling is utilized to generate samples inside the normalized space. These samples are then converted to a physical space using a transformation matrix. The generalized- α method is employed to compute the dynamic response of the system subjected to time-dependent loading. A density-based TO formulation is used to minimize dynamic response. The robust topology optimization problem is defined as bi-criteria optimization to minimize both the mean and variance across all deterministic cases within the ellipsoidal bounds. The solid isotropic material with penalization method is employed for the interpolation of material stiffness. Helmholtz filter is used to stabilize the problem numerically. The optimality criteria method is used to update the design variables. The proposed scheme's effectiveness and the efficiency of the optimized designs are checked using a set of numerical examples. For most of the cases, robust design exhibits a substantial reduction of approximately 70%–75% in standard deviation when compared with deterministic design. The results demonstrate the proposed framework's ability to reduce structure transient response under uncertain but bounded regions. • A RTO framework for structures under uncertain transient loading is proposed. • Random uncertain-but-bounded loads are modeled using an ellipsoid convex model. • LHS is utilized to generate samples within the bounded uncertain region. • RTO problem is formulated to minimize both mean and variance across uncertain bounds. • The generalized- α method is used to compute the transient response of the system. [ABSTRACT FROM AUTHOR]

• A novel 3D tetra-missing rib auxetic meta-structure is proposed based on tension/compression-twisting coupling principle. • Theoretical formulas for the effective elastic constants of the proposed meta-structure are developed, providing valuable guidance for its optimizations and applications. • The proposed 3D auxetic meta-structure exhibits tunable mechanical properties over broad ranges. Three-dimensional (3D) tunable auxetic meta-structures find widespread applications across various domains. Nevertheless, the existing meta-structures have constrained tunability in their elastic constants, preventing the simultaneous attainment of high stiffness and a prominent auxetic effect. Based on a previously designed 2D tetra-missing rib (TMR) auxetic meta-structure, a novel 3D TMR honeycomb meta-structure was proposed with a tension/compression-twisting coupling effect in this work. To investigate the underlying deformation mechanism of the proposed design, a mechanics model of the elastic constants is formulated by adopting an energy-based approach. The accuracy of the theoretical formulations was then validated both experimentally and numerically. The results indicate the proposed design concurrently exhibits high stiffness and a noticeable auxetic effect. Moreover, tunable Poisson's ratios and elastic modulus within a relative wide range can be obtained by adjusting the geometrical parameters, enabling it adoptable for precise requirements in practical applications. [ABSTRACT FROM AUTHOR]

Industrial heating applications required renewable energy-based solutions to meet his high demands. The recent design exhibition is a three-layer type solar absorber with an effective graphene compilation; Gallium Arsenide (GaAs) in the top (resonator), Aluminium (Al) in the middle (substrate), and Zirconium (Zr) in the ground (based) layer respectively. To show the extinct variation analysis for the used parameters of the design, the perfect six points are selected (micrometers) such as λ 1 = 0.35, λ 2 = 0.6, λ 3 = 0.7, λ 4 = 2.3, λ 5 = 2.65, and λ 6 = 2.85 respectively. In this case of absorption, the whole design absorption rate is 94.36% with the overall wavelength description of 2800 nm, 98.2% is achieved in 700 nm bandwidth, and 96.1% in 1000 nm respectively in this structure absorption area. According to the perfect development of the recent structure, the absorption situation can be expressed in the ultraviolet area, visible spectrum, and near and middle (NIR and MIR) regions. To increase the study of the absorber, the various sections; designs and parameter demonstration, construction design and lithography, absorption ranges and Air Mass (AM) exploration, parameter analysis and color results, Electric and Magnetic field intensities, incident angle changes (0–60°), are presented in the manuscript. The displayed solar design can apply the applications of thermal energy systems usually in the particular area of heating and cooling processes. With the recent solar absorber as a renewable thermal system, the services of heating and cooling, geothermal, and biogenics are also can be performed. Moreover, thermal energy systems of agricultural processes and heat provide applications for industries and buildings that can be also used. [ABSTRACT FROM AUTHOR]

Provably secure keyless hash function uses Random Oracle (RO) or Sponge principles for the design and construction of security-centric hash algorithms. It capitalizes the aforesaid principles to produce outcomes like MD2, MD5, SHA-160, SHA-224/256, SHA-256, SHA-224/512, SHA-256/512, SHA-384/512, SHA-512, and SHA-3. These functions use bitwise AND, OR, XOR, and MOD operators to foresee randomness in their hash outputs. However, the partial breaking of SHA2 and SHA3 families and the breaking of MD5 and SHA-160 algorithms raise concerns on the use of bitwise operators at the block level. The proposed design tries to address this structural flaw through a polynomial function. A polynomial function of degree 128 demands arduous effort to be decoded in the opposing direction. The application of a polynomial on the blocks produces an unpredictable random response. It is a fact that the new design exhibits the merits of the polynomial function on subsets to achieve the avalanche response to a significant level. The output from experiments with more than 24 Million hash searches proves the proposed system is a provably secure hash function. The experiments on avalanche response and confusion and diffusion analysis prove it is an apt choice for security-centric cryptographic applications. [ABSTRACT FROM AUTHOR]

In this paper, a new adiabatic logic family named as adiabatic differential cascode voltage-switch logic (A-DCVSL) for low power applications is presented. The family operates on a two-phase split level sinusoidal power clock instead of four-phase trapezoidal power clock. The proposed A-DCVSL circuits reduce the power dissipation by charge recovery and minimizing the peak current flow. The behavior of the inverter is analysed and the power dissipation of A-DCVSL circuit is mathematically modeled. The performance of A-DCVSL inverters is compared with other existing differential adiabatic logic families. A full subtractor is also designed to exhibit the benefits at the application level. The results confirm that the proposed A-DCVSL circuit outperforms in terms of power dissipation and can be adapted to the design of lower power applications. The simulations were performed on Tanner EDA tool using 32 nm PTM technology parameters. [ABSTRACT FROM AUTHOR]

Ammonia is a carbon-free energy carrier and is anticipated to play a significant role in the global energy system of the future. This work is the first of a two-part paper that uses a multi-scale modeling approach to analyze a hybrid solid oxide fuel cell-gas turbine system concept that operates on NH 3 fuel. The solid oxide fuel cell power module is based on a high-power density Ni-GDC/GDC/SSC cell architecture that is calibrated to experimental button cell data for the intermediate operating temperature range of 500-675 °C. Ammonia decomposition on the surface of the catalytically active Ni-particles in the anode is modeled by an elementary kinetic mechanism whereas a physically based, distributed charge transfer model accounts for the mixed-conducting behavior of the ceria-based electrolyte. Cell performance reduction when scaling from button-cells to full-scale stacks is accounted for in the modeling approach which encompasses pressurized 3-D stack simulations. The simulations disclose that the GDC-based cell design exhibits a significant performance gap between H 2 - and direct NH 3 -operation; in particular, at operating temperatures below 600 °C, which can be attributed to sluggish decomposition kinetics and mass transport resistances specific to NH 3 -operation. However, the simulations suggest that pressurization offers the prospective to significantly boost the cell power density by more than 55% at 0.7 V when switching from 1 to 10 atm, and the need for an external ammonia cracker can be eliminated. Operating the GDC-based cells with ammonia fuel at low temperatures also minimizes the leakage current across the electrolyte. As a prerequisite for mobile applications, the model highlights the principal feasibility of the stack design to simultaneously reach high power densities and efficiencies, yet at the same time, the simulations disclose the need for precisely controlling stack parameters on an integrated system level due to the high sensitivity of stack performance to varying operating conditions. • Multi-scale simulation platform to study GDC-based NH 3 -fueled cells and stacks. • Distributed charge-transfer model shows excellent agreement with experimental data. • Lower performance under direct- NH 3 operation due to kinetic and transport limitations. • Pressurization drastically boosts power density for the GDC-based cell architecture. • Low operation temperatures and NH 3 operation minimize electronic leakage current. [ABSTRACT FROM AUTHOR]

• The mechanical behaviors of LDCB were numerically simulated and verified. • A data-driven computational optimization framework was proposed. • DCQGA-GPR model with higher stability and prediction accuracy was proposed. • DCQGA-GPR-NSGA-III coupling technology proposed was determined as an excellent optimization strategy by benchmarking five algorithms. • The optimized LDCB design exhibits a significant performance improvement. The thin-walled lenticular deployable composite boom (LDCB) is promising for aerospace engineering applications due to its lightweight and compact nature, but its mechanical behaviors are the main challenges limiting its practical application. Here, the axial compression and folding behaviors of LDCB were numerically simulated and the simulation results were verified according to the experimental data in the literature. Then, a new double chains quantum genetic algorithm (DCQGA)-gaussian process regression (GPR) model and data-driven computational optimization framework were proposed and the new model was trained using a database with 400 simulation results, the superiority of which was demonstrated by prediction accuracy evaluation. Additionally, benchmarking five state-of-the-art algorithms found that the coupling technology of DCQGA-GPR-non-dominated sorting genetic algorithm III (NSGA-III) is an excellent optimization strategy to obtain a well-designed structure of LDCB that maximizes the effectiveness of the material while satisfying the lightweight. The optimized LDCB design exhibits a significant performance improvement, with a 26.3 % reduction in the folding moment, a 34.2 % reduction in the maximum Tsai-Hill failure index, a 43.6 % increase in the critical load, and an 11 % reduction in linear density of mass compared to the initial design. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations into the post-fire local buckling behavior and residual resistances of S890 ultra-high strength steel (UHSS) circular hollow section (CHS) under combined compression and bending. The physical testing was firstly conducted and encompassed heating, soaking and cooling of specimens, as well as post-fire tensile coupon tests, measurements of initial local geometric imperfections and eccentrically loaded stub column tests. Then, finite element models were developed and validated with reference to the experimental observations and then adopted for parametric analyses to derive additional numerical data, considering various cross-section dimensions and loading combinations. As a result of the lack of design provisions for ultra-high strength steel structures after exposure to elevated temperatures, the applicability of the relevant ambient temperature design interactive curves given in the current European, American and Australian standards to post-fire S890 UHSS CHS under combined compression and bending was assessed, with post-fire material properties used. The assessment results showed that all design standards exhibited conservative and scattered predictions of residual resistances for S890 UHSS CHS under combined compression and bending at ambient temperature and after exposure to elevated temperatures. The American specification provided more precise predictions of residual failure loads for non-compact and slender (Class 3 and 4) sections than the Eurocode and Australian standard, due to the accurate compression and bending endpoints. In comparison to the American and Australian specifications, the Eurocode resulted in more precise results in predicting residual failure loads of compact (Class 1 and 2) sections, owing to the accurate compression and bending endpoints as well as the nonlinear design interaction curve. • Post-fire behavior of S890 UHSS CHS under combined compression and bending was investigated. • Eighteen post-fire eccentric compression tests were conducted. • FE models were developed and validated against test results and then used to perform parametric studies. • Design rules were assessed for their applicability to S890 UHSS CHS under combined compression and bending. [ABSTRACT FROM AUTHOR]

The manifold microchannel heat sink shows great potential for cooling high-heat-flux electronic equipment owing to its exceptional thermal and flow performance. A new manifold ring-shaped channel design is introduced to improve the temperature uniformity for circular heat sources. A comparative analysis of the manifold straight channel, radial expansion channel and manifold ring-shaped channel designs is conducted based on the same heating area under equal mass flow conditions by numerical investigation using single-phase de-ionized water. The findings indicate that the newly proposed manifold ring-shaped channel design exhibits a lower maximum temperature, a lower average temperature, a better temperature uniformity and a smaller pressure drop in comparison to the straight channel and radial channel designs. Specifically, at a mass flow rate of 2.5 g/s, the ring-shaped channel design demonstrates a 71.4 % and 45.4 % reduction in the temperature difference between the maximum temperature and the minimum temperature of the heating surface, and the coefficient of performance is enhanced by 458.2 % and 169.7 % when compared to the straight channel and radial channel designs, respectively. Additionally, three improved designs based on the original manifold ring-shaped channel design are proposed to further enhance fluid flow distribution in the ring-shaped channel design. The results reveal that all three manifold ring-shaped channel optimizations further lower the maximum temperature, the average temperature and the temperature difference. Notably, the improved case3 exhibits the best thermal and hydraulic performances among all structures. When compared to straight channel and radial channel designs, the improved case3 demonstrates an 86.9 % and 75.0 % reduction in the temperature difference, and an increase of 201.2 % and 523.4 % in coefficient of performance under the equal mass flow comparison basis. A heat flux of 1200 W/cm2 can be dissipated at 6 g/s when the maximum temperature rise is kept below 60 K, with a pressure drop of 38 kPa. • Propose a new manifold ring-shaped channel (MRC) design for electronics cooling of circular heat source. • The MRC design improves temperature uniformity by 71.4% and decreases pressure drop by 71.7%. • The improved MRC design can further improve temperature uniformity by 86.9%, and increase COP by 500%. • 1200 W/cm2 is dissipated for single-phase water cooling with a maximum temperature rise less than 60 K. [ABSTRACT FROM AUTHOR]

Human Cytochrome P450 2J2 (CYP 2J2) is closely associated with various physiological diseases. However, bioluminescence (BL) tools for monitoring CYP 2J2 activity have not yet been reported. Herein, we rationally designed a BL probe, PJ-Luc , capable of real-time imaging of CYP 2J2. In vitro studies demonstrated that PJ-Luc can effectively respond to exogenous CYP 2J2 with high selectivity and a low detection limit (LOD = 0.11 nM). Further, living cell experiments indicated that PJ-Luc can accurately quantify the ratio of endogenous CYP 2J2 amounts in HepG-2-Luc and A549-Luc cells. Moreover, an ultrahigh BL signal-to-noise ratio (S/N = 2.3×105) was achieved in tumor-bearing mouse models. These results suggest that PJ-Luc has great potential in the diagnosis of tumors and other CYP-2J2-related diseases. [Display omitted] • PJ-Luc was designed to exhibit high selectivity and an excellent signal-to-noise ratio specifically towards CYP 2J2. • PJ-Luc enabled an ultrahigh BL signal-to-noise ratio in vitro and in vivo. • PJ-Luc was suitable for distinguishing solid tumors with superior tumor-to-normal tissue ratios. [ABSTRACT FROM AUTHOR]

This study successfully demonstrates the detection of formaldehyde concentration using a fiber bundle with a concave mirror as a reflector. The setup employs an Optical Stimulated Luminescence (OSL) light source connected to the fiber bundle. Light transmitted through the fiber interacts with the formaldehyde solution sample, reflects off the concave mirror, and is received by the collecting fiber before being analyzed by a spectrometer. The experimental results indicate that the detected light intensity decreases linearly with increasing formaldehyde concentration, without any wavelength shift. This suggests that while the absorption properties of formaldehyde remain constant, the quantity of absorbed light increases proportionally with concentration. The sensor design exhibits excellent sensitivity, linearity, and stability, achieving a sensitivity range of 0%–6% at 5004.62 counts/% with a linearity of 97% and a resolution of 0.037%. [ABSTRACT FROM AUTHOR]

As the public puts higher and higher demands on wearing comfort, wearable gas sensors rapidly advance toward intrinsic flexibility and stretchability. However, many challenges arise during the development of intrinsically stretchable sensors. The deformation of the sensor following the movement of the wearer and uncertain changes in environmental humidity can cause additional interference signals. In addition, severe electrode corrosion also challenges the long-term continuous monitoring of sensors. Here, a stretchable strain- and humidity-insensitive O 2 sensor is proposed by adopting a serpentine hydrogel fiber structure and hydrophobic elastomer encapsulation strategy. Besides, the introduction of the Pt/C electrode and salt immersion strategy effectively eliminate electrode corrosion and electrolyte consumption, significantly prolonging hydrogel sensor's lifespan. Importantly, we propose, for the first time, an oxygen pump mechanism to elucidate positive current transferring and electrode corrosion-free in hydrogel oxygen sensors, which is further validated through well-designed experiments. Optimized sensor exhibits a wide detection range (30 ppm-100%), linear sensitivity (0.03%/ppm), exceptional repeatability and remarkable tolerance towards environmental variations. Integrating oxygen sensor with Bluetooth circuit further enables wireless monitoring of oxygen while confirming its practicality. This research provides insights into improving the interference immunity and longevity of flexible oxygen sensors while showcasing their potential in wearable applications. [Display omitted] ● Oxygen pump-based sensing mechanism is introduced to design hydrogel-based oxygen sensors with high stability. ● Hydrogel fiber and elastomer film encapsulation layer are designed to exhibit strain- and humidity-insensitivity. ● Wireless oxygen monitoring system is developed for the practical and comfortable oxygen detection. [ABSTRACT FROM AUTHOR]

Cooling methods for multiple hotspots with high heat flux pose a reliability threat to electronic devices. This study investigates the microchannel-based heat sink performance under various non-uniform heat load conditions for different geometry with three different flow configurations (I, U and Z). An in-house designed Heater Array Unit (HAU) facilitates the generation of both uniform and non-uniform heat loads using a heater power supply. Two different microchannel geometries were employed, namely, microchannel-1 (MC-1) with channel and fin widths of 0.6 mm and 0.33 mm, respectively, and MC-2 with dimensions of 0.64 mm and 0.572 mm. Each microchannel incorporates three manifold configurations (I, U, and Z). Each flow configuration is regulated by flow control valves. Various non-uniform heat load patterns were considered, including streamline, non-streamline, and across-streamline conditions. To assess the thermal performance of the heat sinks the parameters used are thermal resistance (R th), Nusselt number (Nu), and temperature non-uniformity (Ѱ). Experimental findings indicate that the MC-2 design with an I flow configuration is more suitable for uniform heat load conditions. On the contrary, for some non-uniform heat load cases MC-1 also showed up as a suitable design over MC-2. • Experiments were conducted on two microchannel designs (MC-1, MC-2) with three different flow configurations (I, U and Z). • Uniform heat load case, MC-2 design exhibited a 17.8% lower thermal resistance compared to MC-1 with an I-type flow. • In hotspot case #167, the MC-2 design has a 16% higher Nusselt number than the MC-1 design. • Temperature non-uniformity is significantly varies with respect to the non-uniform heat load. [ABSTRACT FROM AUTHOR]

A Negative Capacitance Field effet transistor (NCFET) based Dual split control (DSC) 6T-SRAM cell has been designed and explored with Computing-in memory (CiM) architecture for energy efficient demonstration of Deep neural networks (DNN) basic operation such as Input-Weight (Dot) Product. The impact of ferro electric layer thickness (T fe) on the SRAM cell perfomance metrics such as read noise margin (RNM), write noise margin (WNM) and energy efficiency for read and write operations have been analyzed at supply voltages of 0.3 V and 0.5 V. It has been observed that due to the steep slope characteristics, the NCFET based DSC 6T-SRAM cell design exhibits better RM, WM, and energy efficiency as compared to the baseline CMOS DSC SRAM cell design at V DD = 0.3 V and 0.5 V respectively (with T fe range of 1 nm to 3 nm). Further, NCFET dual split control scheme for 6T-SRAM cell demonstrate improved read stability and write ability when compared with NCFET 6 T-SRAM cell design along with improved energy efficiency. NCFET based DSC 6T-SRAM CiM cell design has ∼22.77× and 12.41× lower energy consumption compared to the équivalent baseline 40 nm CMOS/baseline SRAM CiM design and ∼ 25.80× and 22.76× lower energy consumption compared to the NCFET based SRAM CiM at V DD = 0.3 V and 0.5 V respectively. NCFETs have improved steep subthreshold slope characteristics at an optimal T fe value and NCFET SRAM based CiM circuits are expected to have higher noise margins and lower energy consumption compared to the baseline CMOS designs and are effective for NCFET based computing in-memory architectures with reduced read disturb issues in combination with DSC concept. [ABSTRACT FROM AUTHOR]

Phased array communication and radar systems employ vector modulators (VM) to simultaneously control both phase and amplitude. This paper presents an innovative technique to alternate the RF signal into four quadrants using switchable balun based bi-phase modulators. This switchable balun topology offers a compact Printed Circuit Board (PCB) based VM design as an alternative solution to high-dimensional hybrid couplers or reflection-type pin diodes. Thanks to the balun, the VM circuit dimensions are only 12.7 mm × 25.4 mm with wide frequency bandwidth coverage. Additionally, the total power consumption is only 3 mW due to its entirely passive topology. The developed VM consists of a 90° power divider, switchable balun based bi-phase modulators, digitally controlled attenuators (DCA), and an in-phase power combiner. The proposed VM achieves a 360° phase shift without any dead zones and 31.5 dB attenuation in 9:1 operation bandwidth with lower rms phase and amplitude errors than the other previously reported state of the arts. Also, this design exhibits a calculated better than −31 dB rms error vector magnitude (EVM). Detailed characterization results show that the proposed VM can be used in transmit or receive beamforming networks that operate from 2 GHz to 18 GHz. [ABSTRACT FROM AUTHOR]

The composite tape-spring hinge (CTSH) is a lightweight structural connector widely employed in space structures, including spacecraft and satellites, due to its high specific strength and stiffness. Introducing cutouts enables CTSH to possess folding and deployment capability, while optimizing the cutouts finely to optimize the performance of CTSH. However, the interaction between cutout size and the dynamic deployment of CTSH is a novel topic. To address this, a multi-objective optimization problem is formulated, aiming to minimize both the maximum overshoot angle and deployment time while considering mass constraints. An accelerated size optimization is achieved by integrating data-driven surrogate modeling and size optimization. The optimized CTSH design exhibits a significant improvement in performance, with a 26.3% reduction in the maximum overshoot angle and a 12.6% reduction in the deployment time compared to the initial design. The proposed optimization strategy is highly adaptable and can be applied to various optimization problems, offering valuable insights for future designing space deployable structures with desirable performance. [Display omitted] • Employed a combination of dynamic testing and high-fidelity finite element modeling for accurate characterization of dynamic unfolding behavior of CTSH. • Highlighted the potential of cutouts size optimization in enhancing the dynamic behavior of composite tape spring hinges. • Proposed an accelerated size optimization strategy using data-driven surrogate modeling. • Optimized CTSH design reduces overshoot angle and deployment time by 12.6% and 26.3% respectively, while saving 97% in computational costs. [ABSTRACT FROM AUTHOR]

• Thermal seizure mechanism of three bump foil models are investigated. • Optimization for foil structure to reduce the thermal failure risk. • Thin bump foil helps mitigate the risk of thermal failure. • Integrated bump foil optimizes the load capacity and thermal failure risk. The problems of wear and failure seriously endangers the operational quality and life of foil bearings. This work establishes a thermo-elastic-hydrodynamic foil thrust bearing model to investigate thermal failure performance and compare it with an elastic-hydrodynamic model. The study analysis the thermo-elastic mechanism and thermal seizure behavior of three different bump foil models. Alterations in foil parameters and structure to optimize the risk of bearing thermal failure. Findings indicate that the bump foil design has a significant impact on the risk of thermal failure, and the bump foil's fixed position determines the characteristic of the thermal seizure risk. The integrated bump foil design exhibits superior load performance and risk resistance compared to the separated type. The inner radius of the bump foil is greater than 13.5 mm and the thickness is less than 125 μm, which helps reduce the risk of thermal failure. Consequently, the proposed optimization is beneficial for the design and operation of foil bearings resist thermal failure. [Display omitted] [ABSTRACT FROM AUTHOR]

As silicon field-effect transistors encounter increasing scaling challenges, digital system designers are shifting their attention towards multi-valued logic (MVL), specifically ternary logic. The graphene nanoribbon field-effect transistor (GNRFET) emerges as a compelling alternative among post-MOSFET technologies for the implementation of ternary logic. This paper delves into the computational intricacies of ternary logic, underscores the outstanding features of GNRFET technology, and introduces a novel GNRFET-based 1-trit ternary multiplier (TMUL) requiring only 26 transistors. The performance of the design is assessed using the Synopsis HSPICE simulator with a 32-nm GNRFET model file operating at V DD = 0.9 V. The proposed TMUL surpasses existing designs due to its efficient paths with a minimal number of transistors for each output transition, a singular power supply voltage, and an extended voltage division scheme. In comparison to other contemporary TMUL designs, the proposed design exhibits a notable enhancement, showcasing a 21.42 % reduction in delay, a 33.11 % decrease in power-delay-product (PDP), and a 58.17 % decrease in energy-delay-product (EDP). Additionally, the design is subjected to thorough testing under diverse conditions including process, voltage, temperature (PVT) fluctuations, and load variations, validating its reliability and robustness. [ABSTRACT FROM AUTHOR]

In this paper, a multifunctional metasurface antenna is proposed that can both generate orbital angular momentum (OAM) vortex waves with two different modes and reduce the radar cross section (RCS) in a broad band. By utilizing the generalized Snell's law, a phase-gradient matesurface is proposed as the coating of the antenna to realize a broadband RCS reduction in the range of 11.8 GHz–29 GHz. The two feeding networks for the slot array are designed to independently generate OAM waves with mode −1 and +1 in the range of 9.68 GHz–10.35 GHz. Based on the OAM spectral analysis, the purity of the generated OAM modes is also discussed. This proposed antenna is fabricated and measured, and the experimental results achieve a good agreement with those got from the simulation. It is also shown that our design exhibits superior performance over other existing antennas in terms of impedance bandwidth and RCS reduction bandwidth, which provides a sufficient approach for the OAM antenna with broadband low-RCS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thin PEI and PVDF interlayers (IL) arrest mode-I crack in epoxy materials. • Finite element models predict crack tip shielding by these toughened interlayers. • Initial toughness & stiffness are influenced by epoxy-IL compatibility. • Crack-reinitiation load is increased up to 2.5 times. • Energy absorption is enhanced up to 43 times. This work examines the crack-arresting capability of PEI and PVDF thermoplastic interlayers in short-glass fiber modified and core–shell rubber toughened epoxy materials under mode-I fracture loading. Experimental results show that the initial crack can be effectively arrested by the thermoplastic-epoxy interface and reinitiation of this crack at the thermoplastic layer requires up to 2.5 times higher load than the crack initiation load of the pristine epoxies. The interlayered designs also exhibit a significant increase in energy absorption by up to 43 times more than their pristine counterparts. Competing damage mechanisms and failure events are captured by microscopy images, digital image correlation and high-speed photography observations. Additionally, elasto-plastic fracture mechanics models based on configurational material forces theory are developed for a preliminary crack-arresting material selection and to elucidate the material inhomogeneity effects. [ABSTRACT FROM AUTHOR]

This paper addresses deficiencies in the separating efficiency of conventional spiral-roof cyclone separators compared to flat-roof cyclone separators. A novel design is proposed, adding spiral guide vanes into the spiral-roof cyclone separator's annular space. The performance of the new spiral-roof cyclone separator is evaluated through cold-model experiments and numerical simulations and compared with conventional flat-roof and spiral-roof counterparts. The results demonstrate a more than 20% reduction in pressure drop compared to the flat-roof cyclone. The new design exhibits 3%–5% higher efficiency than the conventional spiral-roof cyclone and surpasses the flat-roof cyclone by 2%–3%. The numerical simulations investigate tangential velocity distribution, airflow residence time, short-circuit flow air volume, particles carried away by short-circuit flow, and vortex core stability. The findings confirm the new spiral-roof cyclone as a low-pressure and highly efficient separator with promising practical applications in diverse gas-solid separation operations. This study designed a new spiral-roof cyclone separator with spiral guide vanes in annular space. It was found that the efficiency of the new spiral-roof cyclone could be substantially improved. The goal of "improving efficiency and reducing resistance" was achieved. Furthermore, the mechanism for improving the performance of the new spiral roof cyclone was revealed from the perspectives of short-circuit flow and vortex core stability. [Display omitted] • Designing a new spiral-roof cyclone separator with spiral guide vanes. • Improving the efficiency of conventional spiral-roof separators. • Enhancing the efficiency by 2% ∼ 3% and reducing the pressure drop by 20%. • Revealing the mechanism for the performance enhancement. [ABSTRACT FROM AUTHOR]

Generation IV high-temperature gas-cooled reactors (HTGR) are designed to exhibit passive safety under all off-normal circumstances. One such scenario, known as depressurized loss of forced circulation (DLOFC), occurs after a break in the inlet/outlet header, allowing helium to leak from the reactor. Upon depressurization, the onset of natural circulation (ONC) can occur causing bulk air ingress leading to the oxidation and degradation of core components. The Transformational Challenge Reactor (TCR) has similar features to those of an HTGR, but the primary difference is the use of a more complex, additively manufactured (AM) fuel geometry. The more compact, additively manufactured, ceramic fuel elements can be conveniently produced with optimally configured channels that suppress the air ingress progress and improve thermofluidic performance. DLOFC and air ingress are experimentally studied in a scaled HTGR flow test setup. The experiments use an AM test element embedded with a distributed temperature sensor as well as a test geometry comprised of spherical pebble bed elements. With the test geometries aligned within a lowercase h-shaped tube flow setup, further data was obtained to improve the understanding of DLOFC. The thermal transient and air ingress data gathered for both test geometries are compared. The results show that the AM part delayed ONC as compared to the pebble bed test piece at higher temperatures. The distributed temperature sensor shows intra-leg circulation at higher temperature tests. [ABSTRACT FROM AUTHOR]

The rotational energy harvester (REH) has been widely investigated as a potential method to power electronic devices in the Internet of Things. Despite the advances in the REH, there remains a challenge to sufficiently harvest energy from low frequency rotations. To address this issue, a plucking REH with tapered thickness and auxetic structures (TAPREH) is proposed in this paper. By incorporating a tapered thickness beam, auxetic structures, and frequency up-conversion method, the proposed design can improve the generated energy under low frequency excitations. The performance of the proposed design is analyzed using finite element simulation, which shows a good agreement with the corresponding experimental results. Experimental validation of the proposed design revealed a peak power output of 0.489 mW at 1.5 Hz, representing an increase of 898% compared to the conventional plucking REH without auxetic structures (PREH). Moreover, the proposed design exhibits a more uniform stress distribution compared with the existing plucking REH with uniform thickness and auxetic structures (UAPREH). Consequently, the peak power output of the proposed design is increased by 186% compared with that of UAPREH while having lower maximum stress. • Propose a plucking rotational energy harvester with tapered thickness and auxetic structures. • Improve the power output of rotational energy harvester under low-rotational-frequency excitations. • Perform finite element analysis to analyze the performance of the harvester. • Experimentally validate the proposed designand conduct parametric study. [ABSTRACT FROM AUTHOR]

• The absorber design exhibits a peak absorption at 3.31 GHz. The proposed structure is remarkably thin, with a total absorber thickness of 0.0184 λ with double-negative properties. • The fractional bandwidth is measured at 5.4 %, centered at 3.31 GHz.Structure is insensitivity to polarization angles up to 90°, and a wide incidence angle range of up to 50°. The current work offers an electromagnetic metamaterial absorber that uses the double-a1Qnegative property and is designed for operation in the 1 to 4 GHz frequency range, with a peak absorption at 3.31 GHz, emphasizing S-band applications. The suggested structure is very thin, having a total absorber thickness of 0.0184 λ. It was constructed using CST software and simulated with a frequency domain solver. The unit cell's performance is studied at different polarization angles (φ) and incidence angles (θ). The results show good design, insensitivity to polarization angles up to 90°, and a wide incidence angle range of up to 50°. The investigation comprises an analysis of the electric field (E field) and surface current to supplement the absorption analysis. The suggested design is developed by parameter studies, which include changes to the split gap, loss tangent, and testing alternative substrate materials and thicknesses. The resonance frequencies vary somewhat according to array arrangements, resulting in double-negative characteristics. The fractional bandwidth is 5.4 %, with a central frequency of 3.31 GHz. The suggested design is validated using advanced design system (ADS) software, and the comparable circuit is shown to correspond very well with the CST simulation findings. The absorber is constructed on a FR-4 substrate in a 10 x 10 array format. Comparative analysis with existing literature indicates acceptable results, highlighting the potential utility of this metamaterial absorber design in S-band applications. [ABSTRACT FROM AUTHOR]

• This study seeks to enhance the bending, radial, and axial compression properties of 3D printed tubular metamaterials. • The sponge-inspired design exhibits bending stiffness twofold greater than conventional designs. Notably, strength and toughness surge to approximately three and four times higher, respectively, compared to conventional counterparts. • The sponge-inspired design's reinforcement system showcases a remarkable 1.3 times increase in radial compression stiffness compared to unreinforced designs. • The interconnected channels and struts play a pivotal role by uniformly distributing stress. Strengthened tubular structures have had a significant impact on various industries. Advancements in aircraft, construction, medical implants, robotics, and renewable energy have improved safety, efficiency, and durability in multiple sectors. This work explores the practical applications of medical health, using nasal swabs as an example, under different loading scenarios. The study focuses on incorporating bioinspired structural elements, drawing inspiration from the skeletal lattice of sea sponges. By utilizing the sea sponge's process of trial and error in evolution, this bioinspired approach provides a promising perspective on enhancing the mechanical performance of tubular structures. To evaluate the mechanical advantages of the bioinspired design approach, we conducted 3-point bending, radial, and axial compression tests on 3D printed tubular lattice structures. The tests showed that the tubular structure, inspired by sponges, displayed improved bending properties and was approximately twice as stiff as traditional tubular designs. Furthermore, the sponge-inspired design exhibits significantly higher strength and toughness compared to traditional designs, with approximate improvements of 3 and 4 times, respectively. Numerical simulations revealed that these enhancements are attributed to the strengthening effect of diagonally double diagonal struts, which distribute stress evenly and allow for bending without excessive stress concentration. The bio-inspired design shows improved resistance to radial and axial loading, with approximately 1.3 and 3 times greater radial/axial compression stiffness compared to unreinforced designs. These improved mechanical properties of sea sponge-inspired tubular metamaterials make them suitable for a wide range of applications. [ABSTRACT FROM AUTHOR]

This paper proposed a novel type of self-centering (SC) steel beam-to-column connection using superelastic shape memory alloy (SMA) angles and steel angles. Unlike conventional post-tensioned SC connections, the proposed SC connection utilized SMA angles to provide SC ability and moderate energy dissipation, enabling easy installation and replacement. Experimental and numerical studies were conducted to investigate the cyclic behavior of the connection. Two types of steel connections with different configurations were tested: one equipped with SMA angles only and the other with a combination of SMA and steel angles. The cyclic behavior of the SC steel beam-to-column connections was investigated through a series of experiments. A numerical study was also conducted to provide more insight into the mechanical behavior of the connections and the local strain condition of SMA angles. Numerical results were validated with experimental results. Comparative results demonstrated that both connections exhibited desirable flag-shaped hysteresis behavior with SC and energy dissipation. No obvious damage and residual deformation were observed in SMA angles after cyclic loads in both the experiments and numerical simulations, indicating that the SC connection using SMA angles can be reused for successive mainshocks and aftershocks without replacement. Therefore, the proposed SC connection can help achieve the goal of earthquake resilience in structural design. • A novel self-centering (SC) steel beam-to-column connection using SMA angles is proposed. • A series of cyclic loading tests were conducted on the proposed SC connection. • A numerical study of the SC connection was conducted and validated with experiments. • The SC connection with a simple design exhibited desirable cyclic behavior. • The SC connection with SMA angles can be reused for aftershocks without replacement. [ABSTRACT FROM AUTHOR]

An experimental and computational fluid dynamics (CFD) study is carried out to investigate the impact of secondary flow strengthening the thermo-hydraulic performance of discrete multiple inclined baffles in a flat plate solar air heater (SAH) with semi-cylindrical sidewalls. Initially, for a fixed relative baffle height (R h = 0.1), the relative baffle pitch (R p) for continuous baffles is varied in the range of 0.6–1 to obtain the optimum baffle pitch for 6000 < Re < 14000. The impact of gaps at leading, trailing, and both leading and trailing apices are studied as three different configurations with the optimum R p. A maximum thermo-hydraulic performance of 2.69 is obtained for the gap at the trailing apex. The proposed design has a higher collector efficiency, 55–70%, compared to the ribbed rectangular SAH design exhibiting 30–55%. With lower exergy losses, the present SAH design has higher exergetic efficiency (1.5%–2.2%)than ribbed rectangular SAH (0.9%–1.7%) for the range of Re studied. Further, at low Re , the present SAH design has a higher coefficient of performance, indicating that it is cost-effective than ribbed rectangular SAH designs. • Experimental and computational study of the cost-effective solar air heater. • The impact of secondary flow strength on energy and exergetic efficiency is studied. • A maximum overall performance of 2.69 is obtained with gap at the trailing apex. • The present design exhibits higher collector and exergetic efficiency. [ABSTRACT FROM AUTHOR]

• A rigorous optical/electrical model for bifacial perovskite/PERT-silicon tandem solar cells has been developed. • This modeling provides significant insights into the working principles of perovskite/silicon tandem solar cells. • The bifacial design shows an efficiency enhancement of about 30% at the real-world spectral albedo. • The bifacial design exhibits a high perovskite thickness tolerance for cell manufacturing. • The direction of optimization of bifacial perovskite/PERT-silicon tandem cell efficiency was pointed out based on simulation. In this paper, we physically modeled a bifacial perovskite/PERT-silicon tandem solar cells for the first time using Silvaco technology computer-aided design simulator (TCAD). The cell model was calibrated with the reported experimental data of perovskite solar cell (PSC) and PERT-silicon solar cell. The effects of perovskite thickness (t pvk) and perovskite bandgap were investigated on the performance of bifacial tandem solar cells under different albedo. The simulation results predict that the optimum t pvk increases with albedo intensities because a thicker perovskite layer is needed to facilitate current matching for high albedos. Moreover, the t pvk tolerance for a high-efficiency bifacial tandem solar cell increases with albedo. The simulation results reveal an efficiency over 31.9% for 0.45–1 μm of t pvk with 1.65–1.75 eV perovskite bandgap for a bifacial tandem cell under 30% albedo. Additionally, compared to the monofacial cell, the tandem design shows an enhancement of about 30% at the spectral albedo level of common grounds like concrete. The simulation and analysis presented in this work can help optimize perovskite/silicon tandem cell manufacturing to achieve higher power conversion efficiencies. [ABSTRACT FROM AUTHOR]

Electrochemical lateral flow platforms are applied for many applications due to their advantages of higher sensitivity in electrochemical detection than in conventional test strips. However, these devices have low reproducibility since the interface between the test strips and the electrode is difficult to replicate. Herein, for the first time, dual-working electrodes on a lateral flow immunoassay (dWE-LFIA) were used as an internal current on a single device, in which the current of both working electrodes was calculated as a normalized current to increase the device-to-device reproducibility. In this work, the detection of β-lactoglobulin, an allergen found in milk, was used as a model for evaluating the efficacy of dWE-LFIA. A study of reproducibility using this device showed a surprising 15-fold %RSD improvement compared to a single electrode on LFIA. Moreover, the analytical performance of this sensor for detecting β-lactoglobulin exhibited a wide linearity range of 1–1000 ng/mL and a detection resolution of 0.31 ng/mL. Therefore, our design of dWE-LFIA exhibited outstanding performance of high reproducibility, had high sensitivity detection, and could be applied and further developed for commercial biosensors in the future. [Display omitted] • An electrochemical lateral flow immunosensor with high reproducibility was developed. • The dWE-LFIA showed a 15-fold %RSD improvement compared to a single electrode on LFIA. • This device is proposed for the highly sensitive detection of β-lactoglobulin allergen. • The device was effective for the detection β-lactoglobulin in real milk samples. [ABSTRACT FROM AUTHOR]

Existing auxetic honeycomb meta-structures are generally integrated structures with complicated microstructural geometry which hence should be fabricated by costly additive manufacturing (AM) technology. The high cost and low production efficiency of AM technology is still the main bottleneck restricting the engineering applications of such kind of structures. In this work, a prefabricated auxetic honeycomb meta-structure with modularized components was proposed based on mortise and tenon (M&R) principle originated in ancient China. The modularized components of the prefabricated auxetic honeycomb are all tubular structures which can be easily fabricated by traditional manufacturing with low cost and high technical maturity. The mechanical properties of the proposed meta-structure were then detailed investigated numerically under quasi-static and dynamic loading conditions. The referenced integrated auxetic honeycomb meta-structure was also considered as a benchmark for comparison. Results show that the proposed prefabricated design exhibits lower strength and stiffness compared with its integrated counterpart, owing to the introduction of more flexibility. Consequently, the proposed design processes a much more stable stress plateau stage with a larger deformation range and effectively reduces the reactive force of the protected structure. The present work paves a novel avenue to design protective meta-structures with low-cost and high performance. [ABSTRACT FROM AUTHOR]

A bifunctional device is designed to provide flexible control of broadband absorption and polarization conversion based on the insulator-to-metal phase transition material vanadium dioxide (VO 2). When VO 2 is metallic, the switchable metamaterial serves as a broadband absorber consisting of a VO 2 square, the dielectric spacer, and VO 2 film. According to the simulated results, the designed system can obtain more than 90% absorption from 2.62 THz to 6.65 THz with a relative bandwidth of 86.95%. The broadband absorption is unaffected by polarization attributed to the symmetry structure, and it still performs effectively up to incidence angle of 60°. When VO 2 is insulating, a simple anisotropic metamaterial is used to construct a terahertz polarization converter. The numerical calculation shows a linear polarization conversion rate over 90% from 2.2 THz to 6.9 THz, with a corresponding relative bandwidth of 103.2%. The above structure features high efficiency, wide-angle and broad bandwidth advantages. In addition, the design exhibits dual function that can yield broadband absorption and polarization conversion in the same operating band, which opens up new avenues for the development of switchable devices for potential applications in stealth and communications. • A bifunctional device to provide flexible control of broadband absorption and polarization conversion was proposed. • The design exhibits dual function in the same operating band. • The presented metamaterial has a larger relative bandwidth, better stability with the increase of incident angle. [ABSTRACT FROM AUTHOR]

Overlimiting ionic transfer attainable at ion-exchange membranes is a potential way to intensify electromembrane separation processes, such as electrodialysis. The primary mechanisms responsible for overlimiting current are electroconvection, natural convection, and water splitting. For the first time, the present study experimentally investigates all three mechanisms on heterogeneous anion- and cation-exchange membranes, using direct membrane observation and indirect measurement of pH changes in 0.01 M KCl solution. Although the anion- and cation-exchange systems are designed to exhibit the same behavior with different counterions, our results indicate significant differences in the overlimiting ionic transfer. The strong polarization of cation-exchange membranes produced an intensive electroconvective vortex with characteristic velocities in hundreds of μm/s superimposed by an upward electrolyte motion caused by natural convection. No pH changes associated with the water-splitting reaction were observed. The same conditions applied to the anion-exchange membrane resulted in profound pH changes, weaker electroconvection, and natural convection, reaching similar characteristic velocities to the other studied system. Generally, anion-exchange systems were characterized by more significant fluctuations in measured characteristics and were susceptible to fouling by one of the negatively charged markers. The obtained data provide a unified description of phenomena that may occur in the electrodialysis of low-concentrated ionic solutions. [Display omitted] • Overlimiting mechanisms at heterogeneous ion-exchange membranes. • AEMs exhibit more complex and less predictable behavior. • Water splitting is pertinent to AEMs only. • Natural convection and convection at both membrane types. [ABSTRACT FROM AUTHOR]

This paper proposes a new strategy for extending centrifugal compressor stall margin through shroud passive flow control placed at the impeller radial bend. Relative to the usual leading-edge location, the radial bend presents fewer geometrical constraints for flow control devices and allows them to have potentially more impact on low-momentum flow structures that lead to stall. Two centrifugal compressors with fishtail pipe diffusers are chosen for study: a high-speed transonic design exhibiting diffuser stall and a low-subsonic design with exducer stall. Four passive flow control techniques placed on the impeller shroud at the radial bend are evaluated for each compressor, in terms of stall margin improvement and efficiency penalty at design mass flow, using unsteady RANS CFD simulations. These are circumferential groove, slots, impeller recirculation pipe and diffuser-impeller recirculation pipe. The results indicate that passive flow control at the impeller shroud radial bend can be significantly more effective than at the impeller leading edge. For each compressor, the flow mechanisms associated with stall initiation and its delay by the most effective studied flow control technique as well as the associated efficiency penalty are elucidated. The findings indicate that techniques having flow injection with high spanwise penetration and low relative streamwise momentum are most effective for delaying diffuser stall, while the opposite applies to exducer stall. The design point efficiency penalty is due to mixing/shear losses from the jet-in-cross flow phenomenon in the impeller and shear losses from flow redistribution in the diffuser. [ABSTRACT FROM AUTHOR]

In this paper, a hierarchical design framework is proposed for distributed control of multi-agent systems. Different from the traditional distributed design philosophy that directly couples the agents' cooperation and individual regulations, the proposed framework decouples these regulations and separates the distributed control design into two layers, i.e., the layer of reference signal generator design and the layer of tracking controllers design. Specifically, the nodes of the generator play the roles of some virtual agents that achieve the distributed control goal and the agents' tracking controllers are used to track the reference signals produced by the generator. The novel design framework makes the agents reach the distributed control goal well and it has better design flexibility/practicality and stronger versatility/scalability. To demonstrate these advantages, two types of representative examples on hierarchical design are exhibited for multi-agent systems with mismatched disturbances and those with communication/input delays, respectively. All examples confirm that the proposed design framework is a natural choice in the presence of some complex factors, which provides not only simpler design but also more autonomy to the agents. [ABSTRACT FROM AUTHOR]

Cost-effective fishery-independent surveys are critical for obtaining high-quality data to support stock assessment and fisheries management. Classical probability-based sampling designs may exhibit limitations in spatial coverage and flexibility. Spatially balanced sampling (SBS) designs offer the ability to efficiently distribute sampling stations across a survey area. This study evaluates the performance of SBS designs in multispecies fishery-independent surveys through simulation studies, involving two widely used classical sampling designs (Simple Random Sampling and Stratified Random Sampling) and two SBS designs (Generalized Random Tessellation Stratified Model and Balanced Acceptance Sampling). The aim of the simulation study was to assess the performance of different sampling designs in estimating the abundance index for four target fish species across different seasons. The results showed that SBS designs had relatively high accuracy and precision in terms of relative estimation error, relative bias, and coefficient of variation. Among the four sampling designs, the Generalized Random Tessellation Stratified Model performed optimally at the same sample size. In conclusion, this study suggests that SBS designs can enhance the precision of abundance index estimation for different fish species. Given its ability to effectively distribute sampling stations and its flexibility, a better understanding and application of SBS designs in fishery-independent surveys are warranted. • SBS designs showed higher accuracy and precision than classical sampling designs. • The GRTS model was optimal among four sampling designs with same sample sizes. • SBS designs can enhance the precision of abundance index estimation for different fish species. • Further understanding and application of SBS designs are needed in fishery-independent surveys. [ABSTRACT FROM AUTHOR]