Width Of Layer Research Articles

Modeling the Electric Double Layer at the Liposome Vesicle via Classical Density Functional Theory: Solution of Poisson's Equations for Curved Membranes.

The electric double layer at the liposome vesicle membrane has been investigated by a modified fundamental-measure theory in the framework of the restricted primitive model. An analytical equation has been obtained for the mean electrostatic potential (MEP) by solving Poisson's equation for curved membranes. This study investigates the influence of vesicle size, membrane thickness, surface charges, and electrolyte concentration on the structure, composition, and width of electric double layers (EDLs) on the inner and outer membrane walls. Our findings indicate that a thin and denser layer of ions is formed at the concave wall of the membrane (inner wall) compared to that at the outer membrane. As expected, the width of the diffuse layer decreases with the concentration and surface charge. Also, when the surface charges on both concave and convex walls are the same, the absolute value of MEPs on the inner membrane, concave wall, is greater than that on the convex wall. We have also investigated the diffuse potential, which decreases with concentration, membrane thickness, and cavity size, whereas it increases with surface charges. As we expect, the contact density of counterions at the inner concave wall of the vesicle cavity is always greater than the corresponding value at the convex wall, whereas this trend reverses for co-ions. Also, the contact density of counterions (co-ions) at the inner wall decreases (increases) with cavity size, whereas it increases at the outer wall (decreases). Finally, depletion of co-ions occurs at the membrane walls with enhancement in surface charges.

Unveiling the potentiality of a self-powered CGT chalcopyrite-based photodetector: theoretical insights

The article demonstrates the design and modelling of CuGaTe2 direct bandgap (1.18 eV) chalcopyrite-based photodetector (PD), which has superb optical and electronic characteristics and shows remarkable performance on the photodetector. The photodetector has been investigated throughout the work by switching width, carrier and defect densities of particular layers and also the interface defect density of particular interfaces. The various layers have been optimized for the higher performance of the PD. Also, the impression of various device resistances has been analyzed. The JSC and VOC of the heterostructure photodetector is found to be 38.27 mA/cm2 and 0.94 V, in turn. The maximum responsivity, R and detectivity, D* are found to be 0.663A/W and 1.367 × 1016 Jones at a wavelength of 920 nm. The spectral response has a very high value in the range of 800 to 1000 nm light wavelength, which confirmed that this device is capable of detecting the near infrared (NIR) region of light. This work gives important guidance for the manufacture of CGT material-based photodetectors with higher performance.

Modeling heterogenous crowd evacuation on stairs in high-rise buildings using a fine discrete floor field cellular automaton model: Accounting for speed and boundary layer variations

The article investigates the impact of crowd heterogeneities on stair evacuation dynamics in high-rise building. Using a fine discrete floor field cellular automaton (FFCA) model, the study explores the often-overlooked influence of crowd variations in mobility and behaviors. The simulation, set in a 21-story staircase, incorporates variations in speeds and boundary layer widths to replicate the heterogenous crowd dynamics. Key findings reveal that the heterogenous group, considering speed variations, exhibit prolonged stair evacuation time, with children and elderly individuals finishing last. Interactions among individuals with different mobilities lead to a 24.1% blocking effect on young adults' evacuation, while young adults enhance the evacuation of children and elderly by 19.0% and 23.8%, respectively. Children on the inner side of stairs lag behind due to the boundary layer, and the entire heterogeneous crowd's evacuation time decreases by 7.0%, highlighting the efficiency boost from boundary layers. A robust linear correlation is identified between specific outflow and the average desired speed for the heterogeneous group, with a consistent density of 0.46ped/m2 near the exit. The proposed model's validity is supported by trajectories consistent with prior observations and empirical data from homogenous crowd evacuation. The study advances our understanding of evacuation behaviors in heterogenous crowds within high-rise buildings during emergencies.

Discrete ZnO p-n homojunction piezoelectric arrays for self-powered human motion monitoring

Zinc oxide (ZnO), as a typical piezoelectric semiconductor, has gained significant attention in the field of wearable electromechanical coupling. However, the presence of an intrinsic screening effect becomes a bottleneck in developing high-performance ZnO-based piezoelectric devices. To address this limitation, we propose the formation of p-n homojunction by La doping in ZnO nanorods (NRs) as well as discrete structural design to improve their electrical output and flexibility. The enhanced performance and the mechanism behind it are explored and revealed in terms of morphology, structure, built-in electric field, depletion layer width, and junction capacitance, respectively. Benefitting from the excellent electromechanical coupling performance of the developed devices, different human motions can be recognized and classified with the aid of machine learning. These findings provide a new insight into the impact of doping on the output performance of piezoelectric semiconductor devices, thus facilitating advancements in piezoelectric device design and application exploration.

Insights into the efficient water treatment over N-doped carbon nanosheets with layered minerals as template: The role of interfacial electron tunneling and transfer

Peroxymonosulfate (PMS) oxidation reactions have been extensively studied recently. Due to the high material cost and low catalytic capability, PMS oxidation technology cannot be effectively applied in an industrial water treatment process. In this work, we developed a modification strategy based on enhancing the neglected electron tunneling effect to optimize the intrinsic electron transport process of the catalyst. The 2D nitrogen-doped carbon-based nanosheets with small interlayer spacing were prepared by self-polymerization of dopamine hydrochloride inserted into the natural layered bentonite template. Systematic characterizations confirmed that the smaller layer spacing in the 2D nitride-doped carbon-based nanosheets reduces the depletion layer width. The weak electronic shielding effect derived by the small layer spacing on the material subsurface enhanced the bulk electron tunneling effect. More bulk electrons could be migrated to the catalyst surface to activate PMS molecules. The PMS activation system showed ultrafast oxidation capability to degrade organic pollutants and strong ability to resist interference from environmental matrixes due to the optimized electron transfer process. Furthermore, the developed membrane reactor exhibited strong catalytic stability during the continuous degradation of P-Chlorophenol (CP).

The collapse of a sonoluminescent cavitation bubble imaged with X-ray free-electron laser pulses

Single bubble sonoluminescence (SBSL) is the phenomenon of synchronous light emission due to the violent collapse of a single spherical bubble in a liquid, driven by an ultrasonic field. During the bubble collapse, matter inside the bubble reaches extreme conditions of several gigapascals and temperatures on the order of 10000 K, leading to picosecond flashes of visible light. To this day, details regarding the energy focusing mechanism rely on simulations due to the fast dynamics of the bubble collapse and spatial scales below the optical resolution limit. In this work we present phase-contrast holographic imaging with single x-ray free-electron laser (XFEL) pulses of a SBSL cavitation bubble in water. X-rays probe the electron density structure and by that provide a uniquely new view on the bubble interior and its collapse dynamics. The involved fast time-scales are accessed by sub-100 fs XFEL pulses and a custom synchronization scheme for the bubble oscillator. We find that during the whole oscillation cycle the bubble’s density profile can be well described by a simple step-like structure, with the radius R following the dynamics of the Gilmore model. The quantitatively measured internal density and width of the boundary layer exhibit a large variance. Smallest reconstructed bubble sizes reach down to R≃0.8μm , and are consistent with spherical symmetry. While we here achieved a spatial resolution of a few 100 nm, the visibility of the bubble and its internal structure is limited by the total x-ray phase shift which can be scaled with experimental parameters.

Longitudinal Rates of Change in Structural Parameters of Optical Coherence Tomography in Primary Angle Closure Glaucoma following Laser Iridotomy along with Peripheral Iridoplasty.

This study aimed to investigate longitudinal rates of change (LRCs) of structural parameters from optical coherence tomography (OCT) in patients with primary angle closure glaucoma (PACG) after laser iridotomy (LI) along with laser peripheral iridoplasty (PI). Among 146 patients diagnosed with PACG, thirty-two subjects (32 eyes) who underwent LI plus PI and accomplished more than five times of reliable OCT tests were included in the current retrospective study. Retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured by spectral-domain OCT with three month interval. LRCs of global and six Garway-Heath sectors were investigated using the linear mixed-effects model which adjusted BMO area, sex, and age. Imaging of dual Scheimpflug analyzer was performed before and at 1 week after LI with PI and yearly thereafter. The mean follow-up period was 32.28 ± 13.34 months with a mean number of 10.18 ± 3.33 OCT images. Baseline characteristics are as follows: age, 63 ± 7.9 years; female, 62.5%; intraocular pressure(IOP), 15.48 ± 4.79 mmHg; anterior chamber depth, 2.09 ± 0.18 mm; and mean deviation, -7.97 ± 8.48 dB. Global LRC of BMO-MRW was 0.86 ± 1.34 μm/yr and RNFL was -0.64 ± 0.22 μm/yr. IOP decreased significantly to 13.06 ± 2.21 mmHg (p=0.001) while anterior chamber volume (p=0.011) and mean anterior chamber angle (p=0.022) increased significantly after LI along with PI compared to the baseline at the final visit. LRC of a new parameter, BMO-MRW, and LRC of RNFL were relatively low in patients with PACG, following LI along with PI. After widening of the anterior chamber angle and decrease of IOP due to LI plus PI, PACG might show stable structural prognosis assessed by OCT.

Dynamic stabilization of ablative Rayleigh-Taylor instability in the presence of a temporally modulated laser pulse.

This paper presents a numeric study of the dynamic stabilization of the ablative Rayleigh-Taylor instability (ARTI) in the presence of a temporally modulated laser pulse. The results show that the specially modulated laser produces a dynamically stabilized configuration near the ablation front. The physical features of the relevant laser-driven parameters in the unperturbed ablative flows have been analyzed to reveal the inherent stability mechanism underlying the dynamically stabilized configuration. A single-mode ARTI for the modulated laser pulse is first compared with that of the unmodulated laser pulse. The results show that the modulated laser stabilizes the surface perturbations and reduces the linear growth rate and enhancement of the cutoff wavelength. For multimode perturbations, the dynamic stabilization effect of the modulated laser pulse contributes to suppress the small-scale structure and reduce the width of the mixing layer. Moreover, the results show that the stabilization effect of the modulated laser pulse decreases as the maximum wavelength increases.

Optimization of process parameters for laser cladding Stellite6 cobalt-based alloy

As a new remanufacturing technology, laser cladding can repair damaged parts in large valves in nuclear power plants. The objective is to enhance the surface morphology quality of parts post-remodeling, the paper optimizes the key process parameters in the laser cladding process. Numerical simulation was used to analyze the influence of each process parameter ( laser power, scanning speed, powder feeding speed) on the morphology of the cladding layer. The laser power and powder feeding rate were positively correlated with the width of the cladding layer, and the scanning speed was negatively correlated with the width of the cladding layer. The orthogonal experiments are designed based on the Taguchi method, and the Stellite6 single cobalt-based alloy cladding layer was prepared on the WCB low-carbon steel substrate. Analysis of variance and RSM was used to analyze the experimental results. The influence order of process parameters on the morphology of the cladding layer was determined. The regression prediction model was established to analyze the relationship between the process parameters and the morphology quality (width and height) of the cladding layer. The errors of the model are 5% and 3.5%, respectively. The optimal combination of process parameters is determined as follows: P = 1700 W, Vs = 8 mm/s, Vf = 26 g/min. The cladding layer prepared by the optimal process parameters has fine structure and good bonding. The accuracy of the predictions was validated using this model, which offered valuable theoretical guidance for predicting and controlling the geometric characteristics of the laser cladding of Stellite6 alloy.

Intelligent multi-objective optimization of 3D printing low-carbon concrete for multi-scenario requirements

This study presents, for the first time, a universal theoretical framework based on machine learning (ML) algorithms for the multi-objective optimization (MOO) design of 3D printing low-carbon concrete to meet the sustainability requirements of the construction industry. The study focuses on the simultaneous reduction of carbon emissions and costs during the design process. Specifically, the applicable scenarios are primarily classified into two categories: meet aesthetics requirements (printing layer height error-HE and printing layer width error-WE approaching 0) and strengths requirements (compressive strength-CS approaching 60 MPa and interlayer bonding strength-IBS as high as possible). Through a comparison with the traditional design method, 3D printing concrete based on the intelligent design method achieves a 44% reduction in costs and a 19% reduction in carbon emissions while meeting aesthetics requirements. Under strengths requirements, there is a 57% reduction in costs and a 22% reduction in carbon emissions. This demonstrates the indispensable and crucial role of the MOO method employed in this study in achieving the lowest costs and carbon emissions. Additionally, the results of experimental verification demonstrate that the models developed in this study have successfully achieved a close alignment between design values and experimental values within the allowable error range (The errors are 3.46%–9.83%). This not only holds the potential to drive the widespread application of 3D printing technology in the construction industry but also presents new possibilities for cleaner production, contributing to the achievement of sustainable development goals.

Enhanced Photoelectrochemical Activity Realized from WS2 Thin Films Prepared by RF‐Magnetron Sputtering for Water Splitting

AbstractWe report the synthesis of tungsten sulfide (WS2) films using RF‐magnetron sputtering at different RF powers. X‐ray diffraction (XRD) data confirm the hexagonal crystal structure of WS2 with an average crystallite size of ∼44.54 Å. With increased RF power, the preferred orientation of WS2 crystallites shifts from (002) to (100). Linear sweep voltammetry (LSV) was used to assess the Photoelectrochemical (PEC) activity of WS2 films. The film deposited at 150 W demonstrated the highest photocurrent density of 5.44 mA/cm2. The 150 W film also showed a lower Tafel slope of ∼0.374 V/decade, indicating superior PEC activity. Mott Schottky's (MS) analysis revealed a notable shift in the flat band potential towards the negative side, suggesting a shifting of the Fermi level towards the conduction band. WS2 film grown at 150 W demonstrated a majority charge carrier density of 6.2×1021 cm−3 and a depletion layer width of 1.54 nm. The observed low charge transfer resistance of 155 Ω contributed to the enhanced PEC activity with a relaxation time constant of 37 ms. These properties suggest that WS2 can be suitable for PEC water splitting.

Shape Morphing of 4D-Printed Polylactic Acid Structures under Thermal Stimuli: An Experimental and Finite Element Analysis

This study explores the shape-morphing behavior of 4D-printed structures made from Polylactic Acid (PLA), a prominent bio-sourced shape-memory polymer. Focusing on the response of these structures to thermal stimuli, this research investigates how various printing parameters influence their morphing capabilities. The experimental approach integrates design and slicing, printing using fused deposition modeling (FDM), and a post-printing activation phase in a controlled laboratory environment. This process aims to replicate the external stimuli that induce shape morphing, highlighting the dynamic potential of 4D printing. Utilizing Taguchi’s Design of Experiments (DoE), this study examines the effects of printing speed, layer height, layer width, nozzle temperature, bed temperature, and activation temperature on the morphing behavior. The analysis includes precise measurements of deformation parameters, providing a comprehensive understanding of the morphing process. Regression models demonstrate strong correlations with observed data, suggesting their effectiveness in predicting responses based on control parameters. Additionally, finite element analysis (FEA) modeling successfully predicts the performance of these structures, validating its application as a design tool in 4D printing. This research contributes to the understanding of 4D printing dynamics and offers insights for optimizing printing processes to harness the full potential of shape-morphing materials. It sets a foundation for future research, particularly in exploring the relationship between printing parameters and the functional capabilities of 4D-printed structures.

Experimental study and numerical analysis on the axial compression performance of CFRP strip reinforced round-end aluminum alloy tube concrete column

Round-end aluminum alloy tube concrete columns had good durability and were very economical, but the low strength and elastic modulus of aluminum alloy led to the need for improvement in performance. This paper proposes carbon fiber reinforced plastic (CFRP) strip reinforced round-end aluminum alloy tube concrete (CREAC) columns and investigates their mechanical properties under axial compression loads. A total of eight specimens were tested, including seven CFRP reinforced specimens and one control specimen. The effects of the width, spacing, and number of layers of CFRP strips on the axial compression performance of CREAC under the same amount of CFRP were studied. The experimental results indicate that the main failure modes of the specimen are the buckling of round-end aluminum alloy tubes and the fracture of CFRP strips. The CFRP strip can significantly improve the ultimate bearing capacity of the specimen, with a maximum increase of 15.3% in the test range. When the amount of CFRP is the same, as the number of CFRP strips decreases, the bearing capacity and ductility deteriorate. Increasing the width and thickness of CFRP strips significantly improves ductility. On the basis of the validated finite element model, parameter analysis was conducted, and the calculation method for stability coefficients was fitted. A calculation method for axial compression bearing capacity suitable for CREAC was proposed, with a maximum error of less than 1% between the predicted results and experimental results.

The impact of nozzle diameter and printing speed on geopolymer-based 3D-Printed concrete structures: Numerical modeling and experimental validation

3D Concrete Printing (3DCP) is a promising technology with significant advantages for the construction industry, encompassing reduced labor costs, diminished carbon dioxide emissions, enhanced time efficiency, improved user convenience, and design flexibility. To ensure optimal structural outcomes and resource efficiency, integrating numerical modeling and simulation is imperative for predicting structural behavior and identifying potential premature failures in 3DCP. Despite the recognized importance of this integration, the impact of different printing parameters on numerical models, particularly with variations in printing speed and printing layer, remains an unexplored area. This research delves into the influence of crucial printing parameters, specifically printing speed and nozzle diameter, on the buildability of 3D-printed structures within the built environment. A comprehensive experimental analysis is conducted on geopolymer-based 3D-printed structures, encompassing diverse process parameters associated with 3D printing (3DP) technology. A numerical model is deployed to predict the buildability of these structures, and its results are compared with experimental findings, assessing the efficacy of numerical modeling under varying printing parameter conditions. Rigorous characterization of input material properties is undertaken to ensure the accuracy of numerical simulations. Experimental results showcase favorable processability and buildability of geopolymer materials derived from novel Construction and Demolition Waste (CDW). Findings indicate that an increased nozzle size, reflected in greater layer height and width, positively influences buildability, whereas higher printing speeds correlate with reduced buildability. The numerical model successfully captures these buildability trends, though with an error ranging from 32 % to 45 % in predicting failure in 3D-printed structures. Nevertheless, the overall performance of the numerical model remains reliable in predicting the influence of printing parameters on buildability.

Experimental study on flame spreading over locally wetted thin combustibles

This study proposed a better fire-extinguishing strategy by investigating the effectiveness of wetting operations. It also serves as a first step toward developing physical-based discrete fuel flame spread models using a newly developed small-scale test device. This study examined downward flame spread through a dry narrow path sandwiched by wetted zones formed with thin paper, with different levels of wetting and dried layer width. The dynamic flame behavior and the effect of the presence of adjacent wetting zones were studied both experimentally and numerically. The experimental observations revealed three burning patterns, namely unburned, partially burned, and burned-out regions, depending on various locally wetting fuel arrangements. Additionally, the accelerating flame spread of the wetting case was experimentally reported for the first time. One-dimensional computational simulations suggest that this accelerating phenomenon could be attributed to the chemical reaction triggered by the introduction of water. The reaction rates of OH + CO ↔ H + CO2 and H + O2 + H2O ↔ HO2 + H2O increased due to the water vapor, thereby increasing the heat production rate to further promote the preheating of the downward unburned region and flame spread rate. These findings and conclusions shed more light on the physical and chemical effects of water on flame spreading, highlighting another possibility of water accelerating flame propagation.

On mechanical characterization and damage analysis of additively manufactured continuous fiber/poly‐lactic acid bio‐composite using in‐nozzle technique

AbstractThe use of three‐dimensional (3D) printing technology for producing continuous fiber‐reinforced composites has given us the freedom to fabricate individual designs and lightweight composite structures with improved specific strength, modulus, and fatigue resistance. In this direction, utilizing in‐nozzle impregnation, 3D‐printed continuous cotton fiber (CCoF) reinforced poly lactic acid (PLA) bio‐composites have been fabricated, and the influence of varying layer widths (i.e., 0.5, 0.6, 0.7, and 0.8 mm) on the mechanical performance of the CCoF‐PLA composites was investigated. Results revealed that 3D printing of PLA/CCoF at 0.5 mm layer width enhanced the tensile and flexural strength by 1.2 times and 3.1 times compared with 3D printed neat PLA specimens. The relationships between layering width—microstructural characteristics—mechanical properties of PLA/CCoF composite were quantitatively analyzed based on experimental results.Highlights CCoF‐reinforced PLA composites fabricated through a 3D printing routine. CCoF/PLA samples were fabricated at different layer widths (0.5, 0.6, 0.7, and 0.8 mm). Better mechanical performance is achieved at 0.5 mm layer width. σy and UTS of composites enhanced by 1.19 times and 1.87 times, respectively. Ef of composites printed at 0.5 mm layer width enhanced by two times.

Experimental and theoretical study on seismic behavior of a new UHPFRC sandwich wall and wall-wall joint

A new type of precast ultra-high performance concrete (UHPFRC) sandwich wall is proposed in this study. The proposed UHPFRC sandwich wall is composed of the UHPFRC layers, extruded polystyrene foam (XPS) board layer, and short UHPFRC columns connecting the UHPFRC layers. Compared with the traditional reinforced concrete wall, the UHPFRC sandwich wall possesses lower self-weight, less reinforcement, and higher strength. In addition, two types of wall-wall vertical joint connection methods, flexible cable connection and embedded steel plate welding connection, are proposed. The pseudo-static tests on five UHPFRC sandwich wall specimens were conducted to study the effects of UHPFRC layer thickness, reinforcement ratio, and width of edge solid area on the seismic behavior of the wall. Then, the seismic performance of different connection methods was studied by pseudo-static tests on two T-shaped UHPFRC sandwich wall-wall joint specimens. Test results demonstrate that the unreinforced UHPFRC sandwich wall, with 20–30 mm UHPFRC thickness and 150 mm edge solid area, showed excellent cracking resistance and seismic behavior. The cracking loads are more than 50% of the peak loads, and the bottom shear capacity to self-weight ratios are generally more than 35. The seismic behavior of the wall-wall joints connected by the flexible cable and embedded steel plate welding are both reliable. Finally, formulas for cracking and peak load of the UHPFRC sandwich wall are proposed and the fiber model is developed for analysis of the wall-wall joint, which is verified by the test results to be accurate and reasonable.

Overexpression of ameloblastin in secretory ameloblasts results in demarcated, hypomineralized opacities in enamel.

Introduction: Developmental defects of the enamel manifest before tooth eruption and include amelogenesis imperfecta, a rare disease of underlying gene mutations, and molar-incisor hypomineralization (MIH), a prevalent disease in children originating from environmental and epigenetic factors. MIH enamel presents as the abnormal enamel marked by loss of translucency, demarcation between the healthy and affected enamel, and reduced mineral content. The pathophysiology of opaque, demarcated enamel lesions is not understood; however, the retention of enamel proteins in the matrix has been suggested. Ameloblastin (Ambn) is an enamel protein of the secreted calcium-binding phosphoproteins (SCPPs) critical for enamel formation. When the Ambn gene is mutated or deleted, teeth are affected by hypoplastic amelogenesis imperfecta. Methods: In this study, enamel formation in mice was analyzed when transgenic Ambn was overexpressed from the amelogenin promoter encoding full-length Ambn. Ambn was under- and overexpressed at six increasing concentrations in separate mouse lines. Results: Mice overexpressing Ambn displayed opaque enamel at low concentrations and demarcated lesions at high concentrations. The severity of enamel lesions increased starting from the inner enamel close to the dentino-enamel junction (DEJ) to span the entire width of the enamel layer in demarcated areas. Associated with the opaque enamel were 17-kDa Ambn cleavage products, a prolonged secretory stage, and a thin basement membrane in the maturation stage. Ambn accumulations found in the innermost enamel close to the DEJ and the mineralization front correlated with reduced mineral content. Demarcated enamel lesions were associated with Ambn species of 17kDa and higher, prolonged secretory and transition stages, a thin basement membrane, and shortened maturation stages. Hypomineralized opacities were delineated against the surrounding mineralized enamel and adjacent to ameloblasts detached from the enamel surface. Inefficient Ambn cleavage, loss of contact between ameloblasts, and the altered basement membrane curtailed the endocytic activity; thus, enamel proteins remained unresorbed in the matrix. Ameloblasts have the ability to distinguish between Ambn concentration and Ambn cleavage products through finely tuned feedback mechanisms. The under- or overexpression of Ambn in murine secretory ameloblasts results in either hypoplastic amelogenesis imperfecta or hypomineralization with opaque or sharply demarcated boundaries of lesions, similar to MIH.

Effects of welding parameters on Inconel 625 coating synthesised by tungsten inert gas cladding

Inconel 625 coatings were synthesised on AISI 4130 steel substrates by tungsten inert gas welding. Optimisation of process parameters was conducted through a combination of numerical simulations and technological experiments. The welding speed has a significant effect on the width and height of the cladding layer and the welding current mainly affected the penetration. A proper decrease of welding speed with raising heat input was conductive to the decrease of coating residual stress levels and dilution rates, which promoted the solid solution of corrosion resistant elements (Mo and Nb) and favoured the improvement of coating corrosion resistance. The cladding quality and efficiency could be improved by parameter optimisations through the combination of numerical and technological methods.

Practical robust fixed-time containment control for multi-agent systems under actuator faults

This article considers a containment control problem for nonlinear multi-agent systems with nonautonomous leaders under directed topology, where each follower may experience various actuator faults and unknown external disturbances. A practical robust fixed-time fault-tolerant controller is proposed that eliminates the adverse effects of disturbances and actuator faults while achieving the containment control objective within a fixed-time. Independent of initial states, a sufficient condition of practical robust fixed-time stabilization is derived, further relaxing the constraint of robust fixed-time stabilization. The combination of sliding-mode control and event-triggered mechanism in this approach provides better control performance. One advantage of this method is that the sliding-mode band size is no longer dependent on the sampling interval but rather on the triggering function. Another advantage is that the resource costs for handling faults are effectively reduced. Additionally, an adaptive boundary layer technique is designed to avoid chattering phenomenon of the discontinuous controller, which utilizes adaptive parameters to autonomously adjust the width of boundary layer. Zeno behavior analysis and a simulated example are also presented.