Simple Design Approach Research Articles

Estimation and Control of Positive Complex Networks Using Linear Programming

This paper focuses on event-triggered state estimation and control of positive complex networks. An event-triggered condition is provided for discrete-time complex networks by which an event-based state estimator and an estimator-based controller are designed through matrix decomposition technology. Thus, the system is converted to an interval uncertain system. The positivity and the L1-gain stability of complex networks are ensured by resorting to a co-positive Lyapunov function. All conditions are solvable in terms of linear programming. Finally, the effectiveness of the proposed state estimator and controller are verified by a numerical example. The main contributions of this paper are as follows: (i) A positive complex network framework is constructed based on an event-triggered strategy, (ii) a new state estimator and an estimator-based controller are proposed, and (iii) a simple analysis and design approach consisting of a co-positive Lyapunov function and linear programming is presented for positive complex networks.

Implementasi Sistem Pemerintahan Berbasis Elektronik (SPBE) di Dinas Komunikasi dan Informatika Kabupaten Sijunjung

Abstract: This research reveals how the Electronic-Based Government System is implemented in the Sijunjung Regency Communication and Information Service. In accordance with Sijunjung Regent Regulation Number 29 of 2019, the Sijunjung Regency Communication and Information Service was appointed as the agency responsible for the application of information and communication technology in the implementation of SPBE in Sijunjung Regency. Based on the results of monitoring and evaluation carried out by the Ministry of State Apparatus Empowerment, Reform and Bureaucracy (Kemen PAN RB) in 2022, Sijunjung Regency achieved the lowest SPBE index number 2 in West Sumatra Province with an index value of 2.18% (fair). Researchers used a quasi-qualitative research method (Quasi Qualitative) with a simple research design (SRD) approach. The informants in this research consisted of 9 people consisting of the regional secretary, three employees of the Communication and Information Department and 5 employees from each OPD who the author chose for research using purposive sampling. The data collection techniques applied in this research are observation, interviews and documentation. Meanwhile, the data analysis applied in this research uses triangulation techniques. Based on the results of the analysis using e-Government implementation theory according to Indrajit, the results obtained were that in application development not all OPDs coordinated with the Communication and Information Department in developing applications. Then training and competency development has been carried out by the Sijunjung district communications and information services office for all operators in agencies implementing SPBE. Regarding the availability of network infrastructure, there are still many network flashing spots in Sijunjung Regency. Regional regulations related to SPBE management have been prepared by the regional government of Sijunjung Regency. Human resource procurement is focused on adding employees who understand programming, and the capital used in implementing SPBE uses APBD with a limited budget.

Axially Chiral Multiple Resonance Thermally Activated Delayed Fluorescence Enantiomers for Efficient Circularly Polarized Electroluminescence

AbstractThe chiral materials and circularly polarized organic light‐emitting diodes (CP‐OLEDs) have potential applications in 3D display due to the generation of circularly polarized luminescence (CPL). However, achieving a combination of chirality, high efficiency, and narrowband emission for thermally activated delayed fluorescence (TADF) materials has proven to be a challenging endeavor, often involving complicated synthesis and chiral separation processes. In this study, a simple design approach is introduced by direct connection of the multiple resonance (MR) skeleton and chiral (R/S)‐1,1′‐binaphthyl units, obtaining two pairs of chiral MR‐TADF enantiomers (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN without chiral resolution. These enantiomers exhibit blue‐green emissions with photoluminescence quantum efficiencies of up to 98% in doped films and full‐width at half‐maximum of 22 nm both in toluene and in the device. Furthermore, (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN display symmetric CPL spectra with dissymmetry factors (gPL) of + 3.86( ± 0.317) × 10−4/‐3.37( ± 0.317) × 10−4 and + 7.09( ± 0.233) × 10−4/‐7.74(± 0.233) × 10−4, respectively. The CP‐OLEDs based on (R/S)‐DtCzB‐OBN and (R/S)‐DtCzB‐BN exhibit impressive maximum external quantum efficiencies of 30.0% and 33.9%, as well as gEL factors of +3.40( ± 0.362) × 10−4/‐3.11( ± 0.362) × 10−4 and + 7.99( ± 0.391) × 10−4/‐8.19( ± 0.391) × 10−4, respectively. This research proposes a strategy for directly constructing chiral MR‐TADF materials for high‐performance CP‐OLEDs, avoiding complicated chiral separation.

Sensing Characteristic Analysis of All-Dielectric Metasurfaces Based on Fano Resonance in Near-Infrared Regime

A novel, all-dielectric metasurface, featuring a missing wedge-shaped nanodisk, is proposed to investigate optical characteristics. By introducing symmetry-breaking to induce Fano resonance, the metasurface achieves an impressive Q-factor of 1202 in the near-infrared spectrum, with a remarkably narrow full width at half maximum (FWHM) of less than 1 nm. The ability to adjust the wavelength resonance by manipulating the structure of the wedge-shaped nanodisk offers a simple and efficient approach for metasurface design. This breakthrough holds great potential for various applications in sensing and optical filtering, marking a significant advancement in the field of nanophotonics.

Analytical Review of Numerical Analysis in Hydrodynamic Performance of the Ship: Effect to Hull-Form Modifications

<span lang="EN-GB">This review paper provides an overview of simulation-based hydrodynamic design optimization for ship hull forms. It also includes a numerical analysis aimed at accomplish early-stage simulation-based design in terms of hydrodynamic performance. A hydrodynamic module, a hull surface modeling module, and an optimization module are the primary components of this numerical analysis. The hydrodynamic module includes both simple design approaches and high-fidelity numeric tools; these integrated tools are used to evaluate hydrodynamic performances at different design stages. The hull surface modeling module offers a variety of techniques for ship hull surface representation and modification. It is also used to automatically create hull forms or change existing hull forms based on hydrodynamic performance and design constraints. The optimization module includes several optimization algorithms and surrogate models used to determine optimal designs in terms of hydrodynamic performance. Numerical findings indicate that the current tool is well suited for hull form design optimization at the early design stage because it can produce effective optimal designs within a short time.</span>

Enhancing the Luminescence Efficiency of Blue Phosphorescent Organic Light‐Emitting Diodes: Constructing Platinum(II) Complexes with a Functionalized Tetradentate Ligand

AbstractEfficient, electrochemically stable blue phosphors are essential for advancing the organic light‐emitting diode (OLED) industry. Specifically, the characteristics of these phosphors must be further refined to realize commercially viable OLED devices with high stability, efficiency, and color purity. To that end, a new simple molecular design approach is devised in this study for synthesizing tetradentate‐ligand‐based Pt(II) complexes exhibiting intense blue emission. Essentially, novel Pt(II) complexes Pt3 and Pt4 are prepared by introducing the tert‐butyl and cyano groups to the ligand of previously reported highly stable, efficient Pt(II) complexes for preventing molecular aggregation and regulating the frontier levels, respectively, and then fully characterized. Both complexes display a blue emission band in solution and solid states with remarkably low full‐width‐at‐half‐maximum values. Additionally, multilayer phosphorescent OLEDs are fabricated using Pt3 or Pt4 as emitters and SiCzCz/SiTrzCz2 as a mixed‐host system. The devices demonstrate outstanding performance parameters, such as higher efficiencies than those of the devices containing the previously reported Pt(II) complexes and good color purity (CIEy ≈ 0.18). These findings suggest that the molecular design approach employed in this study for creating tetradentate‐ligand‐based Pt(II) blue phosphors is effective and can potentially expedite the commercialization of blue phosphorescent emitters in the OLED industry.

(Invited) Limitation of Molecular Twisting: Upgrading a Donor-Acceptor Dye to Drive H2 Evolution

Dye-sensitized photoelectrochemical cells (DSPECs) have attracted wide attention to convert solar energy into high-energy chemicals. A DSPEC consists of a photoanode performing the oxidation half reaction and aphotocathode performing the reduction half reaction. In this presentation I will demonstrate how the performance of a dye-sensitized photocathode can be manipulated to enhance performance and even produce hydrogen! We have used a state- of-the-art dye (D-A P1 dye) on the surface of optimized NiO, and co-adsorbed myristic acid (Tetradecanoic Acid), which has a carboxyl anchoring group and a long apolar alkyl chain. Time-resolved photoluminescence and Density Functional Theory studies show that twisting lowers the energy levels of the photoexcited D-A dye, while twisting is inhibited in case myristic acid is co-adsorbed on the NiO surface. The presence of myristic acid also favors light-induced charge separation, as apparent from femtosecond transient absorption, and increases the apparent photocurrent. Very interestingly, only in the presence of myristic acid, light-induced H2 evolution is observed in aqueous media, despite the absence of a H2 evolution catalyst. We assign the H2 generation to a synergetic effect of inhibited twisting of the D-A dye radical anion increasing its electrochemical potential, combined with charge transfer and conversion of H+ on the hydroxylated NiO surface. Our work illustrates the importance of understanding effects of photoinduced intramolecular twisting and demonstrates that control thereof offers a simple design approach for efficient solar fuel devices.

Earthquake design loads for retaining walls

Free-standing retaining walls are usually designed for earthquake loads assuming cohesionless backfill soil and using the Mononobe-Okabe method. This simple design approach has led to satisfactory performance and is supported by laboratory testing and analytical studies. For major wall structures there are a number of refinements to the method that should be considered. In the paper methods of assessing the influence on the earthquake loads of the flexibility of the wall, soil cohesion and ground water in the backfill are presented. Equations for predicting failure plane angles to allow a better assessment of the soil properties within the failure wedge are included. Procedures for estimating the outward displacement and the influence of passive resistance and wall geometry on the sliding resistance are discussed. Design charts are presented which allow the magnitude of these refinements to be rapidly assessed.

Natural logarithm sliding mode control for vibration control application

This paper presents the control synthesis of a nonlinear sliding mode control, known as the “natural logarithm sliding mode control” (lnSMC), for a general n-th order system. The lnSMC offers a simple and straightforward design approach because it only requires tuning two design parameters. The first parameter has a physical meaning corresponding to the bounds of the state variables, which can be easily determined without a trial-and-error process. The second parameter is related to the controller’s feedback gains, which ensure that the system dynamics converged to the sliding surface. Lyapunov stability theory is used to analyze the closed-loop system and finite-time convergence stability. As a case study, the natural logarithm sliding mode controller is designed to suppress the vibration in a simple spring-mass system and an active suspension system. The simulation study shows that the proposed controllers have significant vibration suppression performance. Furthermore, the simulation study indicates that the sliding mode controller designed by using the natural logarithm sliding manifold outperforms the standard linear sliding manifold counterpart. In addition, due to the nature of the nonlinear switching function that creates boundary states, lnSMC has a huge potential to be applied in a wider area of vibration control.

A Simple Design Approach of Two-Phase Ejectors for CO2 Transcritical Heat Pumps

Integrating a two-phase ejector in mechanical vapor compression heat pumps is a practical and low-cost solution for improving performance and reducing energy consumption. Typically, using an ejector to recover part of the important pressure expansion losses in CO2 systems may improve the operating conditions of the compressor. One of the prerequisites for the success of such an application is the proper design of the ejector. This study is mainly dedicated to developing a simple approach for CO2 ejector design. The advantage of using the ejector as an expander in a transcritical CO2 heat pump is first introduced. Compressor operation is particularly improved. The development of an ejector design model for CO2 expanding from transcritical to two-phase conditions is presented. Validation of the thermodynamic model with experimental results from the literature shows the predictions to be within an acceptable range of discrepancy. The primary nozzle throat diameter calculations do not exceed ±8% of error for transcritical conditions. The error of the predicted pressure at the outlet of the ejector is in the limit of -15% to +3%. A practical design example for estimating the transcritical CO2 ejectors geometry integrated in a heat pump is presented. The results show the important decrease of primary nozzle diameters with the drop of Tevap, especially for the throat. A decrease of Dmix also occurs with Tevap and an optimal diameter is obtained for each condition considered. The design of the diffuser is based on a compromise between the outlet velocity and the length of the diffuser. The detailed design procedure with the proposed model, complemented with data from the literature, is a valuable tool for rapidly generating useful results and obtaining preliminary designs transcritical CO2 ejector.

Hg(II)/Fe(III) Turn‐On Fluorescence Response of Rhodamine‐Anthracene Derivatives with Variable Diamine Chain Length

AbstractTwo rhodamine‐anthracene derivative probes (RA1 and RA2) were designed and synthesized to incorporate different lengths of diamine chains between the rhodamine and anthracene moieties. Among the 16 different metal ions tested, RA1 exhibited the highest fluorescence enhancement in response to Hg2+ with a limit of detection (LOD) of 3.76×10−7 M, while RA2 showed the greatest fluorescence enhancement in the presence of Fe3+ with the LOD of 2.41×10−7 M. Notably, RA1 effectively eliminated the interference caused by Fe3+ during Hg2+ detection, whereas RA2 successfully eliminated the interference of Hg2+ during Fe3+ determination. This response difference between the two ions holds particular importance in scenarios where both heavy metal ions coexist. Additionally, fluorescence microscopy imaging of mouse mammary cancer cells (4T1) under the influence of Fe3+ demonstrated the potential applications of the probe. This study highlights the significance of a simple molecular design approach in tailoring probe selectivity by modifying the intramolecular flexible chain length.

Impurity-driven simultaneous size and crystallinity control of metal nanoparticles

Both the size and crystallinity should be optimized for practical applications utilizing metallic nanoparticles because they strongly influence the nanoparticles property. Herein a liquid phase chemical reduction method controls the defects (crystallinity) in metallic Cu nanoparticles simply and easily. Although the addition of an impurity substance, which cannot be thermodynamically alloyed with Cu, reduces the crystallinity of synthesized Cu nanoparticles, it also affects the deposition behavior, and consequently, the nanoparticle size changes unexpectedly. Therefore, a precise control of the synthesis condition is required to synthesize the nanoparticles having optimal size and crystallinity. To clarify the nanoparticle formation mechanism in an impurity-containing solution, the catalytic activity of the reductant and the redox potential change due to the metastable product are electrochemically evaluated to reveal the correlation between nanoparticle formation behavior and synthesis condition. Finally, the synthesis of two types of Cu nanoparticles, which have similar sizes but different crystallinities is demonstrated. This simple nanomaterial design approach to control the crystallinity and the interpretation of the deposition process in an impurity-containing condition should be widely applicable to metallic nanoparticle syntheses.

Reliability analysis of flexible pavements based on the quantile-value method

ABSTRACT This paper presents a simple yet efficient approach for the reliability-based design of flexible pavements, based on the concept of quantile-values. The reliability-based approaches currently adopted in the pavement design guides are simplified techniques, based on an overall reliability factor. On the other hand, simulation-based probabilistic techniques, widely discussed in literature, can be computationally expensive and tedious to implement. The ‘Simplified Effective Random Dimension Quantile Value Method’ (Simplified ERD-QVM), adopted in this study, presents an elegant technique to bridge the gap between the precision of simulation-based probabilistic techniques and the efficiency of design guide approaches. The accuracy of this technique is verified through Monte Carlo Simulations for different pavement design scenarios. The main advantages of the method are (i) the significant savings in computational times for reliability-based design of flexible pavements without the use of surrogate models (ii) the use of simple techniques already familiar to practitioners who adopt the Mechanistic-Empirical Pavement Design Guide and (iii) it is a comprehensive reliability analysis approach that addresses the drawbacks of the currently used approaches, while capturing the effect of both design parameter and model uncertainty. The methodology for integrating the Simplified ERD-QVM with the existing flexible pavement design codes is also presented.

Correction to: SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

Correction to: SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

A simple Monte Carlo simulation method for geotechnical reliability-based design

ABSTRACT This paper proposes a simple reliability-based design approach from a quantile value perspective. The proposed approach allows the design variable to be efficiently determined without implementing repetitive “trial and error” procedures for a given target reliability index. Only a single run of Monte Carlo simulation is needed to calculate the threshold values of the design variable after the design variable function (DVF) is derived from the limit state function. The threshold values are then sorted in ascending order, and a quantile value is chosen as the desired design variable such that MCS samples with threshold values larger, or smaller than this value are undesired samples. Three illustrative examples are presented following the development of the proposed method and its implementation procedure. Results are validated by calculating the failure probabilities of desired designs using direct MCS, and they are also favorably comparable with those reported in literature. This method can play a complementary role to existing RBD methods due to its advantages of simplicity, efficiency, and robustness.

SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

Impact of the load level on the creep behaviour of adhesively bonded fastener in tension: experimental investigations, analytical and numerical modelling

The use of structural adhesive bonding is increasing in structural assembly. It has indeed several advantages compared to other assembly techniques such as welding and riveting: uniform stress distribution, assembly of materials with different natures, no heat production. This last aspect is particularly interesting for the offshore activities. The firm Cold Pad has developed adhesively bonded fastener solutions, whose aim is to replace welding by structural bonding for the reinforcement of steel structures. Yet, some issues remain about the appraisal of the durability for such assembly and particularly creep. To address this issue, experimental creep investigations were carried out at real scale for one geometry of a fastener bonded with a methacrylate adhesive, and at different tension load levels. An inverse identification method has been developed in a previous study to identify the material creep properties from these investigations, independently of the fastener geometry. Considering the industrial applications of this fastener, the aim of this modelling approach is to describe correctly the primary and secondary creep stages. In this article, this identification method was applied to all the experimental results, using the Burger creep model. The dependency of the parameters with the load level is highlighted, which led to a nonlinear model. These results were then compared to finite element investigations to verify the consistency of the method and its ability to correctly identify the adhesive creep behaviour. This offers good perspectives in the transposition of the study to alternative fastener geometries using simple analytical design approaches. Highlights Bonded fastener’s creep behaviour experimentally investigated under different load levels. Creep modelling using a nonlinear and analytical approach with Burger model Identification of the material creep properties from experimental investigations at real scale on the bonded assembly. Numerical model developed to assess the consistency of the analytical approach.

Nd3+-Ion-Sensitized PZT:Er3+/Yb3+ Gradient Luminescent Layers Using Pulsed Laser Deposition as Alternative to Microlens Array Arrangement for Improving Efficiency of Si Solar Photovoltaic

Using the pulsed laser deposition (PLD) technique via Nd:YAG laser ablation, a transparent luminescent phosphor thin film of homogeneous thickness was created that could effectively absorb both near-infrared (NIR) and ultraviolet (UV) light while simultaneously upconverting and downconverting it to visible light. In single-junction microcrystalline silicon solar photovoltaics (SPV), the use of the gradient luminous phosphor Nd3+-sensitized Er3+/Yb3+ codoped zirconate titanate (PZT) layer was examined. The addition of an Nd3+/Er3+/Yb3+ doped PZT luminescent layer to the back of the solar cell could dramatically extend the lifetime of the device when compared to that of a reference Si solar cell. The proposed model’s light motion was also examined using a theoretical simulation (COMSOL). An attempt was made to find an alternative to existing luminescent solar cell concentrators, i.e., microlens array (MLA) configuration, that functions as spatial light modulators in solar cells in this work. The reported gradient phosphor three-layer design is unique and works as an efficient light-trapping design following the phenomena of total internal reflection in multimode optical fibers. The proposed solar photovoltaics was also created with a nanomirror configuration employing semiconductor nanoparticles for effective light absorption in the back reflector layer. When compared to Si-SPV without the luminescent layer, the frequency upconverted visible emissions can be reabsorbed by the SPV and boost the photocurrent, which increases the overall fill factor from 5.30 to 5.99%. The current methodology offers a simple approach for a high-performance luminescent SPV design.

DNA-modulated single-atom nanozymes with enhanced enzyme-like activity for ultrasensitive detection of dopamine.

Despite the current progress in optimizing and tailoring the performance of nanozymes through structural and synthetic adaptation, there is still a lack of dynamic modulation approaches to alter their catalytic activity. Here, we demonstrate that DNA can act as an auxiliary regulator via a straightforward incubation method with Fe-N-C single-atom nanozymes (SAzymes), causing a leap in the enzyme-like activity of Fe-N-C from moderate to a higher level. The DNA-assisted enhancement is attributed to the increased substrate affinity of Fe-N-C nanozymes through electrostatic attraction between the substrate and DNA. Based on the prepared DNA/Fe-N-C system, colorimetric sensors for dopamine (DA) detection were constructed. Surprisingly, the incorporation of DNA not only enabled the detection of DA in a low concentration range, but also greatly improved the sensitivity with a 436-fold decrease in detection limit. The quantitative determination of DA was achieved in two-segment linear ranges of 0.01-4 μM and 5-100 μM with an ultralow detection limit of 9.56 nM. The DNA/Fe-N-C system shows superior performance compared to the original Fe-N-C system, making it an ideal choice for nanozyme-based biosensors. This simple design approach has paved the way for enhancing nanozyme activity and is expected to serve as a general strategy for optimizing biosensor performance.

Identifying an Interfacial Stabilizer for Regeneration-Free 300 h Electrochemical CO2 Reduction to C2 Products.

The electrochemical CO2 reduction reaction (CO2RR) to produce high value-added hydrocarbons and oxygenates presents a sustainable and compelling approach toward a carbon-neutral society. However, uncontrollable migration of active sites during the electrochemical CO2RR limits its catalytic ability to simultaneously achieve high C2 selectivity and ultradurability. Here, we demonstrate that the generated interfacial CuAlO2 species can efficiently stabilize the highly active sites over the Cu-CuAlO2-Al2O3 catalyst under harsh electrochemical conditions without active sites regeneration for a long-term test. We show that this unique Cu-CuAlO2-Al2O3 catalyst exhibits ultradurable electrochemical CO2RR performance with an 85% C2 Faradaic efficiency for a 300 h test. Such a simple interfacial engineering design approach unveiled in this work would be adaptable to develop various ultradurable catalysts for industrial-scale electrochemical CO2RR.