Design Method Research Articles

Robust optimal design of UFLS schemes in island power systems

Since settings of conventional underfrequency load shedding (UFLS) schemes cannot be adjusted in real-time, this paper proposes a novel robust optimal design method of the UFLS scheme for an island power system (IPS) that once fixed, gives an adequate performance in all possible operating conditions in the IPS. The core of the novel robust optimal design method is the implementation of a synthetic data generation algorithm that covers all the feasible generator operating points, which are further classified into a set of large number (but computationally manageable) representative generation dispatches using clustering techniques. A real-world Spanish island will be used to illustrate the method, where the UFLS robust design will be tested and compared with non-robust UFLS designs tuned using generation dispatches of an actual day of operation provided by both standard and frequency-constrained unit commitment algorithms. Results will show that the proposed robust design avoids frequency constraints violations in contingencies and obtains better frequency metrics.

Novel approach to remote rural heating: Direct coupled photovoltaic electric heater underfloor heating system with phase change materials

Limited access to grids and the unavailability of traditional energy sources present significant challenges to effective heating in remote rural. This paper proposes a direct coupled photovoltaic electric heater underfloor heating system with phase change materials (direct coupled PVEH-UFHs), which eliminates the reliance on the power grid or conventional energy sources for heating in remote areas. The model of the direct coupled photovoltaic electric heating system (direct coupled PVEHs) and the building model with PCM floor were created and the accuracy of the direct coupled PVEHs model was verified experimentally. The study proposes using the total heating achievement rate (THAR) as the evaluation index and identifies the critical parameters affecting the system performance through sensitivity analysis. The results indicate that the photovoltaic capacity factor (PVCF), PCMs thickness and melting temperature are the key parameters affecting the heating performance of the system. The recommended 1.4 PVCF and PCM melting temperature of 294 K. The minimum payback time for system configuration that achieves 90 % THAR is 16.2 years. In summary, this paper proposes a design method and evaluation criteria for direct coupled PVEH-UFHs suitable for energy-efficient heating in remote areas.

Experimental study on the updated optimization method for particle size distribution of lost circulation materials

The use of laboratory methods to simulate the process of plugging slurry sealing the fracture is an efficient and convenient method for Lost Circulation Materials (LCMs) selection and formula design. However, commonly used plugging evaluation devices have defects such as small-scale fractures and low reproducibility. To address these shortcomings, we applied a wellbore-fracture coupling plugging experimental device to simulate the process of plugging slurry extrusion. We processed a large-scale visualized fracture using Plexiglas based on the geometric parameters of the formation fracture, reproduced the undulation characteristics of the fracture surface using laser etching technology, and characterized the three-dimensional morphology characteristics of commonly used calcite, walnut shells, and flake polybutyl ester at the wellsite to carry out experiments on the transportation of LCMs under wellbore-fracture coupling conditions. The results indicate that the discrepancy between laboratory evaluation outcomes and field application practices, as well as the low success rate of single-attempt on-site plugging, can be primarily attributed to mouth sealing. The migration behavior of the LCMs is dictated by its morphological characteristics. A larger disparity among the three-axis diameters leads to increased irregularity in the LCM. Characterization of irregularity yielded the following results: walnut shell exhibits the highest irregularity, followed by flaky polybutene and calcite. Increased irregularity in the LCM corresponds to a heightened risk of mouth sealing. Entry into the fracture can only be guaranteed when the D90/Wf ratios for calcite, flaky polybutene, and walnut shell are less than or equal to 0.56, 0.42, and 0.39, respectively. The methods and findings presented in this study provide a scientific basis for selecting LCMs in fractured formations and explain the reasons for poor loss control and significant repetitive loss in wellsite practice.

Comprehensive evaluation on deposition and heat transfer performance of the mixed tube bundle based on orthogonal experimental study

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 L16(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 Mdep = 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.

Formulation & Evaluation of Anti Migrane Mouth Dissolving Tablet

The objective of this study is to improve the safety, efficacy, and rate of action of the existing molecule by utilising novel techniques to the administration of medication. This will be accomplished by the application of novel approaches. Orally disintegrating pills containing rizatriptan benzoate were made by the direct compression technique in order to provide migraine sufferers with a more expedient manner of gaining relief from their condition. For the purpose of this inquiry, a 32-factororial design method was utilised, and eight different formulations were examined for each of the super disintegrants that were explored. There were a number of tests that were performed on the batches of tablets that were manufactured. These tests included weight variation, hardness, friability, wetting time, invitro dispersion time, drug content, and invitro dissolution. A UV spectrophotometric approach that is easy, sensitive, rapid, accurate, cost-effective, and repeatable was created in order to identify the dose form of Rizatriptan Benzoate tablets. This method was designed in order to determine the dose form. It has been determined that rizatriptan benzoate has the maximum absorbance at a wavelength of 225 nm, and its molar absorption is measured to be 1.619 Ao. According to Beer's law, the application of the law was observed between 1 and 10 μg/ml. In order to validate the conclusions of the investigation, statistical analysis and recovery studies were carried out. In order to validate the method, a number of various criteria were utilised. These criteria included linearity, accuracy, limit of detection (LOD), limit of quantification (LOQ), Sandell's sensitivity, and specificity were among the criteria that were utilised. The practice of determining the regular dosage of Rizatriptan Benzoate in both tablet and bulk forms was found to be one that is accurate and precise via the utilisation of the preferred method. This was identified through the utilisation of the recommended method. A time period ranging from fifteen to thirty seconds was required for the optimised formulation to be distributed throughout the body. Furthermore, it demonstrated a greater water absorption ratio and released 99.60% of the medication over a period of two minutes and fifteen seconds. This was in addition to everything else that it shown.

Compact high attenuation wide rejection bandwidth 5-pole Butterworth LPF using transmission zeros in GaAs process

In this work, a systematic design method for a compact 5-pole Butterworth transverse resonance low pass filter (TR-LPF), in 0.15 μm Gallium Arsenide process, with wide rejection bandwidth (RBW), is presented. The circuit model of TR-LPF and closed-form expressions are provided to appreciate the design process. The fabricated TR-LPF has a cut-off frequency of 10.5 GHz, an insertion loss of 0.4 dB, and the return loss is better than 20 dB. The 20 dB, 30 dB, and 40 dB deep rejection bandwidths (RBWs), across 50 GHz, 45.5 GHz, and 17 GHz respectively, are obtained. The novel use of stubs and spur resonators, within stubs; provides the deep and wide RBW. The compactness of the TR-LPF is realized by the ‘C’-and ‘Z’-shaped folding of stubs. The dimension of the filter is approximately 0.11λg×0.079λg.

A multi-objective optimization design method for underwater composite sandwich structures with high acoustic transmission and low vibration performance

ABSTRACT To address the issue of reduced structural integrity and optimality resulting from the conventional serial design of sonar dome structures, this paper establishes a multi-objective optimal design model for composite sandwich structures, utilising the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The model's stability and reliability are subsequently validated. Upon this model, a structural optimization design technique is postulated for composite sandwich structures within the realm of Fluid-Structure Interaction (FSI) multi-physics coupling. This approach aims to optimize the lightweight, high-rigidity composite sandwich structure, enhancing its acoustic transmission and minimizing vibration performance under turbulent pressure pulsations. The suggested method notably enhances the efficiency of structural design while ensuring precision. The proposed method effectively addresses the deficiency of serially designed sonar domes by neglecting the synergistic effects among multiple disciplines. In summary, this approach offers technical support and new research perspectives for the design of sonar domes under the coupling of multiple physical fields.

Design method and seismic vulnerability of bridges using UHPC-NSC composite pier

The focus of this investigation is the application of ultra-high-performance concrete (UHPC) and normal strength concrete (NSC) in constructing composite piers. The UHPC-NSC composite pier, comprising the external UHPC jacket and internal NSC, demonstrates a marked enhancement in both load-bearing capacity and control of seismic damage. However, the lack of suitable seismic design methodologies presents a significant barrier to the practical application of the composite pier. Drawing on extensive experimental and theoretical research, this paper proposes an optimization formula that determines the diameter of the composite pier and the thickness of the UHPC jacket. This formula aims to maximize the use of UHPC material, manage the damage, and equalize sectional moment resistance with the original reinforced concrete section. Utilizing the proposed design approach, UHPC-NSC composite piers were implemented in a typical continuous beam bridge. Seismic vulnerability analyses were conducted to quantitatively substantiate the performance of the composite pier following the aforementioned design approach. The analysis affirmed that the composite pier effectively reduced the exceeding probability of all damage levels under small and moderate earthquakes, and extensive damage level under strong earthquakes.

A Design Method of an Ultra-Wideband and Easy-to-Array Magic-T: A 6-14 GHz Scaled Model for a mm/submm Camera

AbstractWe established a design method for a Magic-T with a single-layer dielectric/metal structure suitable for both wideband and multi-element applications for millimeter and submillimeter wave imaging observations. The design method was applied to a Magic-T with a coupled-line, stubs, and single-stage impedance transformers in a frequency-scaled model (6–14 GHz) that is relatively easy to demonstrate through manufacturing and evaluation. The major problem is that using the conventional perfect matching condition for a coupled-line alone produces an impractically large width coplanar coupled-line (CPCL) to satisfy the desired bandwidth ratio. In our study, by removing this constraint and optimizing impedances utilizing a circuit simulator with high computation speed, we found a solution with a $$\sim$$ ∼ 180 μm wide CPCL, which is approximately an order of magnitude smaller than the conventional analytical solution. Furthermore, considering the effect of transition discontinuities in the transmission lines, we optimized the line length and obtained a design solution with return loss < − 20 dB, amplitude imbalance < 0.1 dB, and phase imbalance < 0.5$$^{\circ }$$ ∘ from 6.1 to 14.1 GHz.

Tornado-induced instability assessment of super large hyperbolic reinforced concrete cooling towers

Cooling towers are typical high-rise thin-walled structures which are of hyperbolic rotating shell structure type and significantly sensitive to wind loads. Wind-related local instability is the key control factor in the design of structural geometric shape and tower shell thickness optimization. In fact, this kind of stability analysis has only conducted aiming at normal climate (such as monsoon, etc.) under the guideline of series of national Codes. In order to deal with the issues under disaster climate, physical and numerical investigation to evaluate local stability performance of a super large cooling tower (SLCT) under tornado environments based on Buckling Stress State (BSS) method is implemented. Besides, whole process elastic–plastic collapse simulation of the SLCT exposed to the tornados was also carried out to study the failure mechanism and re-evaluated the reasonability of the well-accepted BSS method for structural wind-resistant design. The results revealed that the tornados would have obvious adverse effects on the structural local stability when the SLCT is located at the tornado vortex core radius compared with those under traditional synoptic winds. The swirl ratios and the central distances between the SLCT and the tornado vortex core have significant effects on the local instability of the SLCT. The extended elastic–plastic collapse simulation discovered that the position of the first crack during SLCT collapse process is basically consistent with the critical position from the elastic local stability analysis of the SLCT, indicating that strengthening measures can be carried out in advance at the critical position for structural local stability improvement under tornado conditions. Besides, the extended elastic–plastic collapse numerical simulation of the SLCT could be as the effective supplement to the structural elastic stability assessment (such as BSS method) in the wind-resistant design of the SLCT.

Games With Safety Training Purposes in the Industry: Game Design Method and Its Demonstration

Work accidents are a concern for the industry as they can generate human, material, and economic losses. One way to mitigate them is to conduct efficient safety training, but they cannot always arouse the necessary interest and engagement of those trained. Games with a purpose are tools widely used for training in different contexts. They are identified as innovative, immersive, and attractive approaches, but they are complex to develop. This article presents SafetyPlay Game Design (SpGD), a structured method for designing safety training games with well-defined steps that support translating training elements into an immersive and playful game environment. Since we seek to build an artifact as an intervention to a problem in a real context, we based the research methodology on Action Research to conduct the investigations. Therefore, the intervention in the context of security training continued with creating and demonstrating the SpGD method based on the construction of a digital game for training. In this way, the evaluation undertaken in this research considered two moments: i) the ability of SpGD to develop the game, considering when we evaluated it by volunteers regarding game experience and perception of safety training, and ii) the validated method through interviews with game designers, experts in designing training games. The results point to evidence that the SpGD method supported the design of a game that allowed a positive gaming experience considered by game designers to be viable and useful for this purpose, in addition to allowing people to learn training concepts and risks. Therefore, this research contributes to the game design field and the industry, providing opportunities for creating interactive training that can complement traditional security training.

A mechanically robust and facile shape morphing using tensile-induced buckling.

Inspired by the adaptive mechanisms observed in biological organisms, shape-morphing soft structures have emerged as promising platforms for many applications. In this study, we present a shape-morphing strategy to overcome existing limitations of the intricate fabrication process and the lack of mechanical robustness against mechanical perturbations. Our method uses tensile-induced buckling, achieved by attaching restraining strips to a stretchable substrate. When the substrate is stretched, the stiffness mismatch between the restraining strips and the substrate, and the Poisson's effect on the substrate cause the restraining strips to buckle, thereby transforming initially flat shapes into intricate three-dimensional (3D) configurations. Guided by an inverse design method, we demonstrate the capability to achieve complicated and diverse 3D shapes. Leveraging shape morphing, we further develop soft grippers exhibiting outstanding universality, high grasping efficiencies, and exceptional durability. Our proposed shape-morphing strategy is scalable and material-independent, holding notable potential for applications in soft robotics, haptics, and biomedical devices.

A novel design algorithm for low complexity sparse 2‐D FIR filters

SummaryThe hardware implementation complexity of traditional two‐dimensional (2‐D) finite impulse response (FIR) filters with high order is very high. In this paper, a novel sparse 2‐D FIR filter design algorithm has been proposed by combining the common subexpression elimination technique and sparse filter design algorithms to reduce hardware implementation complexity. First, an initial 2‐D FIR filter with sparse coefficients that meets frequency‐domain specifications is obtained by the sparse filter design algorithm. Then, each filter coefficient is quantized in canonical signed digit, and the sensitivities of all weight‐two subexpressions and isolated non‐zero bits are calculated. Finally, the filter coefficients with low implementation cost are reconstructed via iteratively choosing subexpressions and isolated non‐zero bits in terms of their sensitivities. Simulation results show that the proposed algorithm saves about of adders compared with other low complexity filter design method, which reduces effectively the implementation cost.

Characteristics and analysis of static strain response on typical asphalt pavement using fiber Bragg grating sensing technology

To study the real internal strain response of asphalt pavement and provide crucial data for optimizing pavement design. By burying the fiber grating sensors on site, the strain tests of four asphalt pavement structures under different working conditions were carried out, and the results showed that the static strain time curve is viscoelastic and conforms well to the Bugers model, and the fitting coefficient of determination is 0.98. The strain response of the asphalt surface courses of the four pavement structures under static load shows a double hump variation with the transverse position, with peaks occurring directly beneath the wheel load center. The transverse strain fluctuated between tension and compression, mirroring changes in the lateral position. While longitudinal strains, always tensile, were symmetrically aligned with the centerline of the longitudinal sensors, this pattern differed notably from that of the transverse sensors. In the base layers, the strain profile typically presented a single peak, located at the wheel gap, underscoring a critical area of stress concentration. Numerically, the peak strain of asphalt surface course is larger than that of base course. The most unfavorable loading position of the base course occurs at the wheel gap of the lower base course. The most adverse loading position of the surface course appears at the wheel load at the bottom of the upper or middle course. The research results can provide data support for improving the design method of asphalt pavement.

A stacking machine‐learning based method for accelerating magnetic coupler design with ferrite cores in inductive power transfer applications

AbstractThis paper presents a magnetic coupler design method for WPT systems based on stacking machine‐learning algorithms. A synthetic dataset generated by ANSYS Maxwell is used for training and evaluating machine‐learning models. Stacking technology effectively combines the results from multiple models and make best predictions. The designed model allows us to obtain the optimal values of the coil inner radius and number of turns , when other coil design parameters such as the coil outer radius , the wire diameter , and the coil inductance , are given based on the application environment. The proposed method provides practical solutions meeting design requirements quickly, easily accommodating magnetic couplers with ferrite cores, and showing advantages in designing magnetic couplers with optimal power transfer efficiency.

Application of multi-objective optimization genetic algorithm to design terahertz metamaterials with fano resonances

In the prosperous development of terahertz (THz) metamaterials, Fano resonances have gained attention due to their potential applications in ultrasensitive systems. The performance of Fano resonance is directly influenced by the geometrical parameters of the element structure. However, the traditional design rules for Fano resonances in metamaterials rely on an empirical trial-and-error strategy, necessitating significant effort to achieve optimal results. To address this issue, we propose a design method in this study that utilizes the finite integration technique in time domain (FITD) along with a multi-objective optimization genetic algorithm for the intelligent design of metamaterial structures exhibiting the Fano resonance phenomenon. The FITD method is primarily used to calculate the Fano resonance with different metamaterial geometric structure parameters, while the genetic algorithm efficiently selects the optimal solution. Our method, characterized by high efficiency and complete independence from prior knowledge, could offer a new design technique for metamaterials with specific functions, thereby contributing to the development of THz applications.

Physical design and recent experimental results of the new ICRF antenna on EAST

Two new ICRF antennas operating in the ion cyclotron radio frequency (ICRF) range have been developed for EAST to overcome the low coupling problem of the original antennas. The original ICRF antennas were limited in their power capacity due to insufficient coupling. The new antenna design takes into account both wave coupling and absorption processes through comprehensive wave coupling and absorption codes, with the dominant parallel wave number of 7.5 m−1 at dipole phasing. Through the use of these new ICRF antennas, we are able to achieve 3.8 MW output power and 360 s operation, respectively. The initial experimental results demonstrate the reliability of the antenna design method.

Design method for lens desensitization adapted to refractive index error

The design of optical systems not only considers the imaging performance but also the manufacturing difficulty and feasibility of the system. In practice, errors in the manufacturing process of glass materials and deviations in glass material parameters introduced in complex environments can both lead to degradation in the imaging quality of optical systems. Optical systems that are sensitive to glass material errors face increased manufacturing difficulty and reduced stability. This paper, based on geometrical optics theory, establishes an evaluation function for refractive index error sensitivity and analyzes its relationship with optical parameters and glass materials. It proposes a design method to reduce the refractive index sensitivity of optical systems. Through simulation verification and analysis using examples, the validity of the desensitization design method is confirmed.

A top-down lashing bridge collaborative design method

ABSTRACT The short detailed design cycle of lashing bridges on container ships needs to ensure that various designs have different requirements at multiple locations on the ship, making the design methodology for complex products challenging. Currently, research on the design methodology of lashing bridges lacks in-depth investigation into detailed design aspects. This work addressed research gaps through a top-down collaborative design approach and analysed the principles of propagating design changes in computer-aided design (CAD), as well as proposed a design methodology consisting of four core steps, namely, skeleton decomposition, feature aggregation, detailed design and product structure (PS) expansion. The effectiveness of this methodology was validated through practical design examples and specific variant design instances of a certain type of container ship. The validation demonstrated that the proposed design methodology, in contrast to traditional three-dimensional design methods, supported design process reuse and significantly improved design efficiency in complex product designs.

Efficient Life-Cycle Management: Recyclable self-support MnCuOxS1-x wastewater treatment catalyst for electrosynthesis of benzoic acid to accelerate hydrogen production

Integrating recyclability and reusability into catalyst design can effectively mitigate environmental impact. In this investigation, a three-dimensional Mn-doped Cu2OxS1-x catalyst was incorporated into Cu foam. Following its application in wastewater treatment, the reclaimed catalyst demonstrates robust electrocatalytic prowess in benzyl alcohol oxidation. It efficiently degrades 93.5 % of tetracycline within a 30-minute timeframe in neutral wastewater conditions. Notably, alterations in its morphology and valence state have bolstered its electrocatalytic performance. During the electrosynthesis of benzoic acid, it showcases a diminished starting voltage (1.27 V) while retaining an impressive Faraday efficiency of 97.4 % even at a high voltage of 1.70 V. Density Functional Theory (DFT) analyses shed light on the integration of the catalyst onto Cu foam, facilitating electron transfer from the Cu substrate to the surface catalyst. Furthermore, it is readily recoverable and enhances the adsorption of electrophilic H2O2, thereby augmenting wastewater treatment efficacy. In the context of benzoic acid electrosynthesis, DFT investigations demonstrate that Mn doping significantly enhances the adsorption of OH* and benzyl alcohol in electrocatalysis, thereby enhancing their conversion to benzoic acid. This method of catalyst design, integrating recycling and reuse strategies, has reduced material and energy consumption during catalyst preparation and provided a pathway for the development of advanced catalysts with a focus on sustainability.