Aluminum Plate Research Articles

Investigation of networked SSHI configurations for plate-based piezoelectric energy harvesters

Piezo-patch energy harvesters attached to plate-like structures can be used to extract multimodal vibrational energy. For each piezo-patch, SSHI circuits can boost the harvested power compared to standard rectifier circuits. However, the effect of using different configurations of the SSHI network for multiple piezo-patches on plate structures has not yet been understood. This study aims to assess the performance of the networked SSHI configurations compared to networked rectifier configurations and investigate the optimum configurations for energy harvesting purposes. For this, three piezo-patches are bonded to an aluminum plate and connected to single and/or multiple circuits. The equivalent circuit model (ECM) of the electromechanical system is developed from the experimentally validated analytical model and utilized in simulation software LTspice. The performances of considered configurations are evaluated regarding peak power outputs, and the optimal load resistances are obtained. Based on the experimental findings, the best configuration is determined and verified by simulations. The results show that by using respective SSHIs, the power output can be improved by preventing charge cancellation despite the cost of increased diode loss. This study contributes to our understanding of optimal energy harvesting techniques by investigating the effectiveness of networked SSHI configurations for multiple piezo-patches on plate structures.

On the fracture of aluminum plates perforated by rigid flat-nosed projectiles

We present a series of 2D numerical simulations for the perforation process of aluminum plates impacted by rigid steel cylinders. The simulations accounted for the residual velocities of these projectiles as a function of their impact velocities, as obtained recently by several workers. The aluminum plates in these works were made of the quasi-brittle 2024-T351 and 7075-T651 alloys, and the more ductile 6061-T651 alloy. The material properties of these alloys, for their strength and failure parameters, were taken from published works. We find that the ductility/brittleness property of these alloys is related to the different values of their corresponding strains to failure at shear states. Our simulations for the two quasi-brittle alloys resulted in good agreement with the measured data. On the other hand, the simulations for the 6061-T651 alloy agreed with the corresponding data only when we used a relatively low value of the Taylor-Quinney coefficient for this alloy. We also highlight various problems with the issue of mesh sensitivity in simulating the perforation of metallic plates by rigid cylinders. Particularly, we found that these simulations do not converge to definite values for the residual velocities even when the mesh size is reduced to 0.025 mm. Moreover, we found that the experimental data for the residual velocities can be accounted for by different failure curves, depending on the mesh size of the simulation. Thus, a given failure criterion cannot be validated by such simulations.

Research on broadband vibration reduction performance of high-damping stainless steel fiberboard

This study investigates the application of stainless steel fiberboards (SFBs) for effective vibration reduction in the head section of autonomous underwater vehicles (AUVs). SFBs offer a compelling combination of lightweight design, high static load capacity, and broad-band vibration reduction. To understand their effectiveness, we analyzed the mechanisms behind SFBs’ superior compressive strength and high-damping properties. Furthermore, a finite element model (FEM) of the AUV head section was created using COMSOL software. The model’s accuracy was validated by comparing simulation results with experimental data. This validated model was then employed to calculate the energy consumption of the bearing plate within the AUV’s head section, providing valuable insights for optimizing SFB design for specific vibration reduction applications. The results demonstrate that SFBs of various thicknesses exhibited higher energy consumption ratios compared to the aluminum plates. This finding reinforces the effectiveness of the SFB’s damping mechanism. Additionally, across the 0–6 kHz frequency range, SFBs significantly outperform the aluminum plates, achieving an average improvement of approximately 18 dB in vibration level difference (VLD). These results highlight the excellent vibration reduction performance of SFBs.

Modeling and Analysis of Dispersive Propagation of Structural Waves for Vibro-Localization.

The dispersion of structural waves, where wave speed varies with frequency, introduces significant challenges in accurately localizing occupants in a building based on vibrations caused by their movements. This study presents a novel multi-sensor vibro-localization technique that accounts for dispersion effects, enhancing the accuracy and robustness of occupant localization. The proposed method utilizes a model-based approach to parameterize key propagation phenomena, including wave dispersion and attenuation, which are fitted to observed waveforms. The localization is achieved by maximizing the joint likelihood of the occupant's location based on sensor measurements. The effectiveness of the proposed technique is validated using two experimental datasets: one from a controlled environment involving an aluminum plate and the other from a building-scale experiment conducted at Goodwin Hall, Virginia Tech. Results for the proposed algorithm demonstrates a significant improvement in localization accuracy compared to benchmark algorithms. Specifically, in the aluminum plate experiments, the proposed technique reduced the average localization precision from 7.77 cm to 1.97 cm, representing a ∼74% improvement. Similarly, in the Goodwin Hall experiments, the average localization error decreased from 0.67 m to 0.3 m, with a ∼55% enhancement in accuracy. These findings indicate that the proposed approach outperforms existing methods in accurately determining occupant locations, even in the presence of dispersive wave propagation.

Impact of a Prototype 29:1 Ratio Grid on Image Quality and Radiation Dose in Abdominal Angiography

Objectives The aim of this study was to evaluate the impact of a prototype grid with a 29:1 ratio (r29) and a 15:1 (r15) grid on the image quality (IQ) and radiation dose in abdominal angiography. Materials and Methods Six typical abdominal angiographic image scenarios were created in 4 pigs. Polymethylmethacrylate and aluminum plates were used to add 10 cm of patient equivalent thickness to simulate different body types. Fluoroscopic images were acquired with a source-to-image receptor distance of 120 cm. Tantalum- and iron-specific acquisition protocols at different IQ levels were acquired. IQ of radiation dose equivalent image pairs, created with the r29 and r15 grids, respectively, was quantitatively evaluated using contrast-to-noise ratio (CNR) measurements. Differences in radiation dose were estimated using the dose-weighted CNR. Two blinded readers compared IQ of these images using a Likert scale. In a second step, the readers selected pairs of the r29 and r15 images with subjectively equivalent IQ. Radiation doses were then compared. Results Compared with the r15 grid, the r29 grid images achieved similar CNR at an average of 26% (±12%) lower radiation dose at a mean patient equivalent thickness of 26 cm and 36 cm. Both readers noted a significant increase in IQ (P < 0.001) for dose equivalent images, whereas the interobserver agreement was 0.59. For the selected IQ equivalent images, a radiation dose reduction of 38% (±17%; P < 0.001, interobserver agreement 0.92) was noted when using the r29 grid. Conclusions The use of an r29 grid at a large source-to-image receptor distance can significantly improve the IQ compared with the r15 grid at the same radiation dose in abdominal angiography or can reduce radiation dose while preserving IQ.

Effect of adding ionic liquid into polydimethylsiloxane on the output performance of triboelectric nanogenerator

Abstract Adding 1-butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide (BMIM-TFSI), an ionic liquid, to polydimethylsiloxane (PDMS) films significantly enhances the output of triboelectric nanogenerators (TENGs). In a TENG using contact and separation between the composite film and an aluminum (Al) plate, incorporating 0.1 vol% of BMIM-TFSI more than doubled the output voltage achieved compared to a pure PDMS film. To understand the cause of this improvement, composition analysis around the surface of the composite polymer film was conducted before and after tapping. We found that BMIM-TFSI molecules segregated around the surface after tapping. It is considered that the polarization of the BMIM-TFSI molecules enhances the output performance of TENGs by superimposing on the surface charges generated at the PDMS/Al interface.

Damage Identification Using Meta-Lens and Dual-Enhanced Backscattered Waves: Numerical and Experimental Design

This paper introduces a Meta-lens designed for the detection of minute damage in Structural Health Monitoring (SHM) by amplifying backscattered waves originating from anomalous areas. Our approach starts with the development of an easily installed Meta-lens, optimizing wave focusing on an aluminium plate through strategic planning of the A0 wave trajectory, resembling a hyperbolic secant. Subsequently, we detail the configuration of the actuator, lens, and sensor in both healthy and damaged scenarios, the latter involving a through-hole defect in the plate. A comparative analysis of signals, accounting for damage size and location variations, is conducted against a baseline. The results demonstrate that the Meta-lens induces a unique wave behaviour, resulting in double intensification of backscattered signals, significantly increasing sensitivity to damage features compared to systems without the lens. The focusing effect of the Meta-lens is further validated experimentally, which shows good agreement with the simulation results. The findings underscore the significant potential of employing the Meta-lens for damage detection, thereby eliminating the reliance on intricate sensor networks and complex signal post-processing.

Experimental study on the ignition mechanism of fuel tanks impacted by reactive material fragment

Abstract Fuel tanks are vital components in military assets, such as aircraft and vehicles, where they play a crucial role in operational safety and functionality. High-velocity impacts from fragments pose significant risks, potentially causing ignition and catastrophic damage. To understand the ignition mechanisms under such extreme conditions, a series of ballistic impact experiments were conducted using tungsten-zirconium (W/Zr) alloy fragments. These experiments simulated impacts on the ullage of a fuel tank made of a 2 mm thick aluminium plate. The experiments revealed that W/Zr alloy fragments create distinct perforations in the fuel tank plates. On the front plate, the fragments produced circular holes matching their diameters. However, on the rear plate, the fragments generated much larger, petal-shaped perforations, approximately three times their diameters. Additionally, the study identified a critical ignition velocity for these impacts. When W/Zr alloy fragments impacted the fuel tank at velocities exceeding 866.9 m/s, consistent ignition was observed. As the impact velocity increased further, the intensity of ignition within the fuel tank intensified. Moreover, the location of the ignition shifted progressively from the rear plate towards the front plate, indicating a complex interaction between fragment velocity and fuel tank response.

Stability Assessment through HPTLC for Concurrent Assessment of Azelnidipine and Telmisartan in Mass and Integrated Tablet Drug Formulation

This study aims to estimate the stability assessment through HPTLC for the concurrent assessment of (±)3-(1-diphenylmethylazetidin-3-yl)5-isopropyl-2-amino-1,4-dihydro-6-methyl-4-(3-nitrophenyl)-3,5-pyridine dicarboxylate (Azelnidipine) and 2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl] phenyl]benzoic acid (Telmisartan) in combined tablet formulation, a new HPTLC approach devised and validated that is simple, quick, precise, selective, and accurate stability suggesting. The adsorbent phase used is previously coated with a silica pack on TLC aluminum plates with 60F-254 using Chloroform: Ethyl acetate (5:5 v/v) of a total of 10 ml as the mobile phase. Both Azelnidipine (Rf 0.70) and Telmisartan (Rf 0.17), at 254 nm, densitometric scanning was performed in the reflectance absorptivity mode. In the linearity range of 1-6 μg/ml for Azelnidipine and 5-30 μg/ml for Telmisartan, the calibration graph demonstrated satisfactory linearity with r2 = 0.9967 and 0.9966, respectively. Azelnidipine and Telmisartan percentage assays were discovered to be 98.87 and 100.17. The percent RSD for intraday AZL and TLM experiments was 0.0184 and 0.0068. The percent RSD for AZL and TLM interday trials was discovered as 0.0126 and 0.0068. The LOD for AZL and TLM was discovered as 910 ng/mark and 4570 ng/mark. AZL and TLM were discovered to have LOQs of 2763 ng/mark and 13850 ng/mark, respectively. According to the ICH guidelines, drugs were exposed to acidic, basic, oxidative, photo, and heat-activated degradation. The medication degrades in acidic, basic, oxidative and heat environments but not in light or neutral environments (water). This procedure can be used to efficiently isolate the drug substance from its degradation products and this is used to indicate strength and stability.. KEYWORDS :Azelnidipine, Telmisartan, HPTLC, UV-visible spectroscopy, Validation, Stability studies.

Study on the self-sealing properties of POZD coated aluminium composite structure penetrated by projectiles

Abstract The protective technology of fuel tanks has attracted the attention of scholars at home and abroad, and higher requirements have been placed on the protective coatings of fuel tanks. They must not only meet the requirements of impact resistance but also achieve the function of self-healing of perforation. In order to explore the self-healing effect of fuel tank coatings on perforation by projectiles, a POZD-coated aluminium composite structure was designed. The self-healing mechanism of the POZD-coated aluminium composite structure was analysed using a test research method to explore the effects of coating thickness and aluminium thickness on self-healing performance. The results show that the POZD-coated aluminium composite structure exhibits strong self-healing properties when penetrated by projectiles. The self-healing characteristics are significantly influenced by the application technique and thickness of the POZD coating, whereas the thickness of the aluminum plate exerts a relatively minor effect. Through structural design, the POZD-coated aluminium composite structure can achieve complete self-sealing of perforations by 7.62 mm projectiles, providing a technical reference for the design of lightweight self-healing fuel tanks in the future.

Possibility of Fluid Flow Characterization via a Geophysical Signal: Experimental Study on the Krauklis Wave Under Fluid Flow

AbstractKrauklis waves are generated by pressure disturbances in fluid‐filled cavities and travel along the solid‐fluid interface. Their far‐field radiation, observed in seismic data from volcanoes or hydraulic fracturing, is known as long‐period events. Characterized by low velocity and resonance, Krauklis waves help estimate fracture size and discern fluids in saturated fractures. Despite numerous theoretical models analyzing Krauklis waves, the existing paradigms are founded on static flow conditions. However, in geological contexts, the assumption of static flow may not be valid. We developed an experimental apparatus using a tri‐layer model consisting of a pair of aluminum plates to examine the effect of fluid flow on Krauklis waves. We employed an infusion syringe pump to inject fluids into the fracture under different flow rates. We used water, oil, and an aqueous solution of Polyethylene glycol as fracture fluids. We calculated resonant frequency, phase velocity, and quality factor to characterize the Krauklis waves. Our findings reveal that an increase in flow rate leads to a higher phase velocity, higher quality factor, and a shift to higher resonant frequency when the flow is in the direction of initial wave propagation while decreasing amplitude. Additionally, when the flow is in the opposite direction of initial wave propagation, we note higher wave absorption and distortion of the Krauklis waves. Our observations unequivocally affirm that fluid flow leaves strong signatures on the Krauklis waves, providing a robust basis for characterizing fluid dynamics within geological settings through the analysis of Krauklis wave.

Steel‑aluminum clinched joints mechanical properties and strength prediction under different geometric parameters

With the evolution of modularization and prefabrication in construction, there is a growing adoption of prefabricated thin-wall steel and aluminum structures for lightweight buildings and interior decoration. Clinching emerges as a proficient method for achieving heterogeneous metal connections, offering benefits such as streamlined processes, reduced material usage, environmental friendliness, and potential for automation. This study focuses on high-strength steel DP590 and aluminum alloy AW5754-H22, exploring various process parameters (including punch diameter, punch fillet radius, extensible die diameter, and extensible die depth) tailored for clinching experiments on thin steel and aluminum plates. The research analyzes how these process parameters affect the geometric characteristics of the joints and investigates their mechanical properties through static shear tests. Findings indicate that interlocks exceeding 0.29 mm lead to neck cracks during the clinching process. Additionally, the energy absorption of the specimens in button separation exceeds that in neck fracture by 44 % under comparable maximum failure loads in static shear. Optimal process parameters identified are SR5605-SR60310, achieving a maximum failure load of 4.14kN and an energy absorption value of 12.37 J in static shear tests. Finally, a method is proposed to calculate the shear strength of steel‑aluminum clinched joints based on the transmission dynamics of infectious diseases model (SIR model), accounting for the influence of geometric parameters on the static performance of the joints. This approach accurately describes the load-displacement curve trend and predicts the static shear strength of steel‑aluminum clinched joints effectively.

Design and Analysis of a Solar-Powered Water Heating System

Water heaters consume a large amount of electricity for heating water. Traditional heaters require heating coils to heat up water using a minimum of 2000 Watts for the process. Well, when we use solar energy for water heating it requires around 30 to 50 Watts of power thus saving more a lot of energy. We here developed a more efficient solar water heater to heat up water at a faster rate using efficient coiling along with heat trapping and reflecting mirrors. The water heater can more efficiently heat up water at a faster pace than traditional solar water heaters. The system makes use of steel pipes coiled together for passing water through them. The pipes are heated by solar rays directly falling on them. We additionally use an aluminium plate behind the pipes to absorb the rays passing through in between pipes. Over this we use 2 additional reflective sheets to gather and reflect additional solar rays over the pipes. This system heats up the pipes thus heating up the water passing

Online fatigue crack detection and growth modelling through higher harmonic analysis: A baseline-free approach

This paper presents a novel baseline-free online method for fatigue crack detection and growth modelling of aluminium plates based on the relative second harmonic parameter β′ˆ, which is defined as the ratio of the amplitude of the fundamental frequency A1 over the square of the second harmonic frequency A2, obtained from the response under cyclic fatigue loading. Results reveal that β′ˆ is an effective parameter for online detecting the crack length less than 2 mm and estimating the remaining life, without requiring a baseline signal obtained from the pristine condition. Subsequently, the quantitative relationship between Fatigue crack growth (FCG) and the parameter β′ˆ is developed based on the quadratic polynomial fitting. The reliability of the method is assessed with the Root Mean Square Error (RMSE) and 95% confidence interval. Finally, the robustness of the proposed approach is evaluated by testing specimens with different sensor locations, thereby mitigating the potential sources of uncertainty arising from sensor locations. Results from this research provide a new strategy for online crack detection and growth modelling under fluctuations in loading and boundary conditions.

Full-field measurements of high-frequency micro-vibration under operational conditions using sub-Nyquist-rate 3D-DIC and compressed sensing with order analysis

High-speed imaging is essential for high-frequency vibration measurement techniques that utilize images, such as digital image correlation (DIC). However, it poses challenges, including reduced displacement resolution due to decreased image resolution, increased measurement and calculation costs, and greater data volume. A previous method used compressed sensing to reconstruct time information from images captured with a high-resolution, low-speed camera, allowing high-frequency vibration measurements. However, this method was limited to steady vibrations since waveforms were reconstructed using the Fourier basis. In this study, order analysis is introduced into compressed sensing to measure operational vibrations, including rotation speed fluctuations, such as those in automobile engines. An out-of-plane vibration experiment on an aluminum plate confirmed the method’s accuracy in identifying mode shapes and displacement spectra of operational vibrations. The proposed method reconstructed vibrations (amplitude: several μm to several hundred μm, frequency: 33.3–133.2 Hz) using images captured at 10 fps. The modal assurance criterion (MAC) indicated 0.98 accuracy compared with finite element analysis. The mean squared error below 1 % compared to the frequency spectrum obtained with a laser Doppler vibrometer. Applied to automobile engine vibrations (amplitudes of a few μm), the method achieved errors under 2 % over a 1225 mm × 960 mm field of view. However, error increased for vibrations below the DIC displacement resolution. This method shows promise for analyzing vibrations in rotational machinery, such as engines and motors, through the full-field measurement of high-speed operational vibrations. In addition, the developed compressed sensing with order basis is expected to contribute to the advancement of the recovering missing signals and data compression.

Field shaper-based solutions to the bulging problem in magnetic pulse spot welding of dissimilar metal plates

Magnetic pulse spot welding based on a field shaper can effectively achieve spot welding of dissimilar metal plates by using the multi-turn flat coil and magnetic gathering through the field shaper. Through existing experimental research, it has been found that when using this method for welding, there will be a serious bulging problem in the center of the welding area, which will affect the flatness and aesthetics of the welding area, thereby affecting its application range. To solve this problem, this work proposes two different welding methods for welding dissimilar AA1060 aluminum and SS304 steel plates with a thickness of 1 mm: one based on the center opening of the flying plate and the other based on the pre-deformation of the flying plate. The causes of bulging and the effects of discharge voltage, welding gap, and inner hole radius of the field shaper on bulging size were studied. The cross-sectional morphology and mechanical properties of welded joints obtained by two welding methods were studied through numerical simulation, cross-sectional analysis, and tensile testing. The results indicated that both welding methods can successfully eliminate the bulging problem, and the point welding method based on the center opening of the aluminum plate can also reduce the minimum welding energy required for effective welding and improve welding efficiency. In addition, microscopic analysis results showed that a waveform composite interface was formed at the welding interface of the joint, and the connection performance of the welded joint was good. These two welding methods can also be extended to the welding of other dissimilar metal plates, which is of great significance for the industrial application of magnetic pulse spot welding technology based on field shaper.

Analysis of the Influence of Adhesive, Geometry, and Manufacturing Processes on Mixed Mode Stress Ratio in Single Lap Shear Adhesive Joint Structures of Aluminum and Composite Plates

In aircraft structures, composite plate joints often present significant challenges. Mechanical fastenings such as pins, bolts, or rivets require holes to be drilled in the plates, which reduces the strength of the laminate due to stress concentrations around the hole edges. These joints frequently become sources of structural failure in aircraft. Therefore, the design of composite plate joints is crucial to maintain structural integrity. Adhesive joints offer several advantages over mechanical joints, including the ability to join two different materials, more uniform stress distribution along the joint, and reduced weight since no bolts or rivets are needed. The most common adhesive joint design is the Single Lap Joint (SLJ), which is popular due to its simple geometry and high structural efficiency. However, the main drawback of the SLJ is load eccentricity, which leads to secondary bending and undesirable normal stresses along the adhesive edges. The hypothesis of this study is that SLJ conditions with optimal shear strength can be achieved through the right combination of adhesive type, bond surface preparation, and joint configuration. This study analyzes the influence of various adhesive materials, joint designs, and manufacturing methods using numerical modeling methods, validated with analytical approaches and ASTM standard testing. Numerical modeling is conducted using the finite element method with a cohesive zone model (CZM) approach to examine stress distribution in various cases, such as the impact of geometry, adhesive thickness, and joint length. The normal and shear stress distribution along the joint is found to significantly affect the strength of the SLJ, highlighting the importance of careful design and material selection in these applications.

Role of Glycine in the Electroless Fe-Ni-B Alloy Process for Power Semiconductor Devices

Pyrometallurgically produced Invar Fe-Ni alloys possessing an Fe content of 55–70 mass% exhibit a low coefficient of thermal expansion (CTE). Therefore, one can expect electroless deposited Invar Fe-Ni alloy films to also exhibit a low CTE comparable to those of semiconductor chips and insulating substrates used in semiconductor devices. However, a process for producing an Invar Fe-Ni alloy film by electroless plating has not been established and the thermal expansion properties of the obtained film have not been sufficiently investigated.We prepared electroless Fe-Ni-B alloy thin films using a citrate-pyrophosphate bath as a complexing agent and dimethylamine borane (DMAB) as a reducing agent, whereupon the thermal stress behavior of the thin films was evaluated [1]. In a previously reported plating process [1], the deposition rate of the Invar alloy plated film was 0.6 µm·h−1, which is too slow for practical applications. This deterioration in reaction rate of the electroless plating is caused by the high concentration of Fe2+, known as a stabilizer [2], in the plating bath. It is therefore necessary to improve the process to obtain the ~5–10 μm thickness required for high-density semiconductor packaging.In general, an increase in bath temperature and pH value improves the deposition rate, but this process limits the optimization of these operation conditions owing to the promotion of Fe2+ oxidation and the absence of stable complexes. Therefore, control of the deposition rate was attempted in this study by selecting a complexing agent in the plating bath. Here, we chose glycine [2], which is known to form a complex with Ni2+ in an electroless Ni plating bath and improve the deposition rate of electroless Ni. The glycine was added to the electroless Fe-Ni-B alloy plating bath, and the effect on the deposition of the Fe-Ni-B alloy film was investigated.Table 1 shows the electroless plating bath and plating conditions. The total metal-ion concentration was 50 mmol·L−1. A pure copper plate was used for the substrate, and a contact plating method was used where an aluminum plate was brought into contact with the substrate to initiate the deposition reaction. A 1 h plating time was used in each case.Fig. 1 shows Fe content and deposition rate of the electroless Fe-Ni-B alloy film obtained from the plating bath without or with addition of 1 to 100 mmol·L− 1 glycine, where ratios of Fe2+ / (Fe2+ + Ni2+) were 0.3 and 0.8. In both ratios of Fe2+ / (Fe2+ + Ni2+), Fe content was significantly reduced by adding of glycine of 10 mmol·L-1 or more. The deposition rate increased when glycine was added to the plating bath compared to that in the bath without glycine. When 100 mmol·L-1 of glycine was added, the deposition rate decreased compared to that when 10 mmol·L-1 was added.Using the stability constants of the complexes formed in the bath, it is estimated that when the glycine concentration is up to 10 mmol·L-1, it predominantly coordinates with Ni2+, whereas upon the addition of 100 mmol·L-1, it also forms complexes with Fe2+. As previously mentioned, the electroless plating process utilizing Ni2+ complex ions with glycine as a ligand exhibits a faster rate compared to deposition reactions involving other stable complex ions [2]. It is assumed that the Ni-glycine complex ion species with a high reduction rate becomes dominant in the plating bath containing 10 mmol·L-1 of glycine, so that the reduction rate of the Fe and Ni alloy is accelerated accompanied by acceleration of Ni2+ reduction and reached the maximum value.It turns out that by using glycine as a second complexing agent and optimizing its addition amount in an electroless Fe-Ni-B alloy plating bath, complex ions with a high reduction rate are formed, resulting in the improving of the deposition rate. Acknowledgement This work was supported by JSPS KAKENHI Grant Number JP24K08121.

Optimum Conditions for the Fabrication of Ordered Porous Alumina Via Anodizing in Etidronic Acid at Higher Voltages

Anodizing aluminum in an etidronic acid solution leads to the higher applied voltages of up to approximately 260 V without oxide burning and subsequent formation of porous alumina with a larger interpore distance measuring 650 nm. Typically, the interpore distance increases linearly with the applied voltage during anodizing. However, excess voltage more than 270 V during anodizing in etidronic acid causes oxide burning and the formation of non-uniform porous alumina film. In the present investigation, we describe the optimum operating conditions for the fabrication of ordered porous alumina with larger interpore distance via anodizing in etidronic acid at higher voltages more than 270 V.Commercially available 4N aluminum plates were ultrasonically degreased and electrochemically polished. The pretreated aluminum specimen was placed parallel to a platinum plate as the cathode in a 0.3 M etidronic acid solution (volume: 150-555 mL) at 293 K using an electrochemical cell (inner diameter: 55-105 mm), then anodized under a linear voltage sweep at 0.1 Vs-1and constant voltage of 260-280 V for up to 6 h. The effect of a) the surface area of the platinum cathode (6.28-624 mm2), b) distance between two electrodes (50-90 mm), and c) stirring rate (300-900 rpm) on the anodizing behavior was investigated. The anodized specimens were examined by scanning electron microscopy (SEM).The oxide burning voltages were measured by anodizing in etidronic acid under various operating conditions by the linear voltage sweep method. The burning voltage was unchanged with the surface area of the platinum cathode increased, whereas increased with the stirring rate of the etidronic acid solution due to the efficient Joule heat removal. In addition, the burning voltage increased with decreasing distance between two electrodes at the same stirring rate, because of the higher flow velocity of the solution. As a result, steady-state anodizing can be achieved in etidronic acid at the higher voltage of 270-280 V. Figure 1 shows SEM images of the dimple array formed on the aluminum surface via anodizing at 270 V and 280 V for 6 h. A larger porous alumina measuring 665-726 nm in interpore distance was successfully fabricated via anodizing under the optimum operating condition. Figure 1

Effect of Relative Density on the Lateral Response of Piled Raft Foundation: An Experimental Study

The population surge has led to a corresponding increase in the demand for high-rise buildings, bridges, and other heavy structures. In addition to gravity loads, these structures must withstand lateral loads from earthquakes, wind, ships, vehicles, etc. A piled raft foundation (PRF) has emerged as the most favored system for high-rise buildings due to its ability to resist lateral loads. An experimental study was conducted on three different piled raft model configurations with three different relative densities (Dr) to determine the effect of Dr on the lateral response of a PRF. A model raft was constructed using a 25 mm thick aluminum plate with dimensions of 304.8 mm × 304.8 mm, and galvanized iron (GI) pipes, each 457.2 mm in length, were used to represent the piles. The lateral and vertical load cells were connected to measure the applied loads. It was found that an increase in Dr increased the soil stiffness and led to a decrease in the lateral displacement for all three PRF models. Additionally, the contribution of the piles in resisting the lateral load decreased, whereas the contribution of the raft portion in resisting the lateral load increased. With an increase in Dr from 30% to 90%, the percentage contribution of the raft increased from 42% to 66% for 2PRF, 38% to 61% for 4PRF, and 46% to 70% for 6PRF.