Experimental Analysis Research Articles

Tuning d-band center of Pt via Pt-Pt5La heterostructure interface as efficient and stable electrocatalyst for oxygen reduction and methanol oxidation reactions in DMFCs

Developing Pt-based electrocatalysts with superior activity and durability is essential for direct methanol fuel cells (DMFCs), and regulating the interfacial electronic interaction for Pt-based composites can significantly modulate the electrocatalytic performances. Herein, the Pt-Pt5La/C heterostructure catalyst was developed to enhance the catalytic property towards oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). Experimental analyses and theoretical calculations demonstrated the electron redistribution at the interface and reduction of the d-band center of Pt for this unique Pt-Pt5La/C heterostructure. As the results, Pt-Pt5La/C exhibited 5.0- and 6.4-times higher mass activity and specific activity towards alkaline ORR compared to Pt/C, and the excellent electrocatalytic MOR performance due to the interfacial interaction. These superior electrocatalytic property promoted Pt-Pt5La/C as the bifunctional catalyst for DMFC application with outstanding power density and durability. Consequently, this work proposed a novel interfacial regulation strategy for designing Pt-rare earth (RE) alloy heterostructures and their reliable operation of DMFCs.

Impact Behavior of Prestressed Concrete Piles with Glass FRP Spirals: Experimental and Finite-Element Analysis

Impact Behavior of Prestressed Concrete Piles with Glass FRP Spirals: Experimental and Finite-Element Analysis

Performance testing of an innovative integrated zenithal daylight guide with solar water heater under real-weather conditions

Zenithal Daylight Guides (ZDG) and Solar Water Heaters (SWH) are individual energy-saving solutions utilized across diverse building types. This study proposes an innovative integrated power-saving system, uniting ZDG and SWH into a single model. The integration concept is rooted in leveraging the available space surrounding the daylighting device's pipe to incorporate a solar heater via a serpentine collector. The primary aim of this amalgamation is to optimize solar energy savings, minimize spatial demands, and alleviate manufacturing expenses. Moreover, the impetus behind this study stems from the recent emergence of daytime power outages in Egypt, attributed to heightened consumption surpassing production capacities. The ZDG is still not well known in Egypt. This is the only study until the year 2022/2023 in Aswan, Egypt, that analyzes the performance of this device under extreme sunlight conditions (with maximum global illumination reaching approximately 118 Klux). Across various seasons, the lighting and thermal efficacy of the current model underwent experimental testing and analysis to assess its practical utility. The integrated system effectively elevated the water temperature and achieved adequate light transmission, as indicated by the obtained results. The average transmitted indoor illumination on the work surface reached approximately 2470 lux. The reliance on electrical lighting could be mitigated for up to 5 hours. On the other hand, the highest water temperature and maximum instantaneous efficiency reached are about 70°C and 37%, respectively. Throughout the experiments, the proposed solar heater achieved a maximum daily thermal efficiency of 31.5%. The findings are deemed satisfactory and promising.

CoNiOOH nanosheets array enables highly effective value-added chemicals production via nitrite and sulfide electrolysis

Here, we show that the CoNiOOH nanosheets array can be applied for catalyzing nitrite reduction and sulfide oxidation reactions (NO2RR and SOR) simultaneously, realizing NH3 production and synchronous desulfuration. As a result, the catalyst achieves a maximal Faradic efficiency of 93 % with the corresponding yield rate of 14.6mg h−1 cm−2 for NH3 production and high robustness over 4 consecutive cycles. Beyond that, it could trigger the SOR with a low potential of 0.65 V vs RHE to reach 100 mA cm−2, far lower than that needed for the water oxidation (1.62 V vs RHE). More importantly, the coupling system composed of NO2RR and SOR could realize value-added products on both sides. Theoretical and experimental analyses validate that Ni regulates the electronic structure of Co site, which optimizes the activation and adsorption of reactants and intermediates, and thus reduce the energy barriers, accounting for the performance enhancement.

Comparative experimental analysis of monocrystalline and polycrystalline photovoltaic panel through hybrid phase change material

Photovoltaics thermal management is utmost necessary as continuous heating of the module decreases the performance. This paper presents a comparative study in terms of performance of two photovoltaic modules namely monocrystalline and polycrystalline using hybrid phase change materials (PCMs). The hybrid PCMs of RT31 and RT 44HC were prepared by method of stirring. The final prepared hybrid PCMs were poured at the back of panel and panel was covered. The purpose of these experiments is to improve the efficiency of polycrystalline and monocrystalline photovoltaic modules and comparing which technology is more efficient having hybrid PCM. The experiments were performed under the room conditions in Taxila, Pakistan. The output parameters of the photovoltaic module appeared to be strongly dependent upon the solar irradiance. The power output and efficiency of monocrystalline and polycrystalline photovoltaic module were measured. The monocrystalline panel maximum temperature was 36.59 °C as compared to polycrystalline panel which was 40.23 °C. As the radiation intensity increased till noon, electrical power was improved, and it was 6.52 W in monocrystalline panel as compared to polycrystalline panel which was 6.32 W. Electrical conversion efficiency was also observed, and it was maximum up to 11.84 % in monocrystalline panel. The higher performance was observed in case of monocrystalline panel having hybrid in terms of performance as compared to polycrystalline panel.

Comparative investigation, analysis, and optimisation of weld reinforcement during powder-fed gas metal arc welding of AISI 1023

ABSTRACT The main aim of the present study is to perform a comparative investigation, experimental analysis, and optimisation of weld reinforcement in the specific domain of powder-fed gas metal arc welding in relation to AISI 1023 steel. The study conducted a comprehensive analysis of several parameters, encompassing statistical methodologies (i.e. Genetic Algorithm and artificial neural networks) and response surface methodology (RSM). The study shows that the advance gas metal arc welding provides maximum of 95% more reinforcement and current and powder feed rate has emerged as the most influential parameter for bead reinforcement. Based on the results obtained, it can be concluded that the Levenberg-Marquardt (5-14-1) model demonstrates the highest level of suitability as an ANN model for the purpose of forecasting output data. As per R value positive correlation of 0.9674 between the empirical data and the forecasts produced by the LM (5-14-1) model. Genetic algorithm suggested that the optimal point is situated within the predetermined range of process variables. According to validation experimentation the ANN model exhibited superior performance compared to the RSM model and then come GA. ANN has shown the maximum error of 0.06 when compared to experimental results.

Accuracy of kinetic equilibrium reconstruction of NSTX and NSTX-U plasmas and its impact on the transport and stability analysis

Abstract An accurate magnetohydrodynamic (MHD) equilibrium reconstruction is an essential starting point for stability and transport plasma analysis. This work describes an approach for obtaining kinetic equilibrium reconstructions using the OMFIT framework, which has been applied for the first time to spherical tokamak data from NSTX and NSTX-U. The EFIT equilibrium solver is integrated with experimental data analysis procedures and subsequent TRANSP transport simulations to enhance the accuracy of the reconstruction, in particular at the edge region, by adding constraints on the total pressure and current density profiles, based on the transport code solution. The accuracy of the equilibrium depends on the uncertainty and number of constraints, as well as the choice of basis functions to represent the pressure and current density profiles. An improved fidelity of the equilibrium reconstruction is demonstrated by reducing the variability of the magnetic axis and boundary locations from several centimeters for reconstructions based on magnetic and experimental pressure constraints to only several millimeters for kinetic reconstructions based on transport code constraints, when different representations for basis functions were tested. Variability of the safety factor on-axis was reduced ten times in the same sensitivity study. The accuracy of the equilibrium reconstruction and subsequent mapping of experimental kinetic profile data have a significant impact on TGLF and linear CGYRO turbulence simulations, which predict different spectra of unstable modes and turbulent fluxes for cases with different numbers of constraints in the equilibrium reconstruction. Conversely, the stability analysis performed with the GATO code shows plasmas stable to n = 1 MHD modes in both equilibria using magnetic and experimental pressure constraints as well as the transport code constrained equilibrium. However, a scan of parameters away from these conditions shows considerable deviation in the threshold of unstable modes between these reconstructions. Therefore, for reliable plasma analysis and use in turbulence and stability calculations, a high fidelity equilibrium reconstruction with accurate kinetic constraints based on transport code solutions is necessary.

Impact of Soybean Biodiesel Blends with Mixed Graphene Nanoparticles on Compression Ignition Engine Performance and Emission: An Experimental and ANN Analysis

Impact of Soybean Biodiesel Blends with Mixed Graphene Nanoparticles on Compression Ignition Engine Performance and Emission: An Experimental and ANN Analysis

Nonplanar Nanographene: A Hydrocarbon Hole-Transporting Material That Competes with Triarylamines.

Hole-transporting materials (HTMs) are essential for optoelectronic devices, such as organic light-emitting diodes (OLEDs), dye-sensitized solar cells, and perovskite solar cells. Triarylamines have been employed as HTMs since they were introduced in 1987. However, heteroatoms or side chains embedded in the core skeleton of triarylamines can cause thermal and chemical stability problems. Herein, we report that hexabenzo[a,c,fg,j,l,op]tetracene (HBT), a small nonplanar nanographene, functions as a hydrocarbon HTM with hole transport properties that match those of triarylamine-based HTMs. X-ray structural analysis and theoretical calculations revealed effective multidirectional orbital interactions and transfer integrals for HBT. In-depth experimental and theoretical analyses revealed that the nonplanarity-inducing annulative π-extension can achieve not only a stable amorphous state in bulk films, but also a higher increase in the highest occupied molecular orbital level than conventional linear or cyclic π-extension. Furthermore, an in-house manufactured HBT-based OLED exhibited excellent performance, featuring superior curves for current density-voltage, external quantum efficiency-luminance, and lifetime compared to those of representative triarylamine-based OLEDs. A notable improvement in device lifetime was observed for the HBT-based OLED, highlighting the advantages of the hydrocarbon HTM. This study demonstrates the immense potential of small nonplanar nanographenes for optoelectronic device applications.

Feline eye-inspired artificial vision for enhanced camouflage breaking under diverse light conditions.

Biologically inspired artificial vision research has led to innovative robotic vision systems with low optical aberration, wide field of view, and compact form factor. However, challenges persist in object detection and recognition against complex backgrounds and varied lighting. Inspired by the feline eye, which features a vertically elongated pupil and tapetum lucidum, this study introduces an artificial vision system designed for superior object detection and recognition in a monocular framework. Using a slit-like elliptical aperture and a patterned metal reflector beneath a hemispherical silicon photodiode array, the system reduces excessive light and enhances photosensitivity. This design achieves clear focus under bright light and enhanced sensitivity in dim conditions. Theoretical and experimental analyses demonstrate the system's ability to filter redundant information and detect camouflaged objects in diverse lighting, representing a substantial advancement in monocular camera technology and the potential of biomimicry in optical innovations.

Decorated Bone Tube Manufacture in Early Bronze Age Israel: Experimental Analysis of Bone Preparation and Incising

ABSTRACT Experimental replication of decorated bone tubes was carried out to determine possible methods of defleshing and to define the nature of linear cut-marks on the bones made by different cutting implements. These studies were carried out to interpret more precisely the production techniques for incised bone tubes recovered from Early Bronze Age (EB) contexts at the site of Tell el-Hesi dating to 2800–2700 bce (EBIIIA). Previous studies had assumed that the bones were incised using metal chisels found on-site, but the new experiments demonstrate that the incised lines were most likely made using denticulated metal (copper/bronze) saws. Modern cow metapodials were defleshed and then cut and sawn with different types of tools. Impressions were made of the experimental and archaeological incised lines and the impressions were studied using Scanning Electron Microscopy. The incised lines made using denticulated metal saws most closely match the incised lines of the ancient incised bone tubes.

Experimental Analysis of Noise Characteristics on Different Types of Pavements inside and outside Highway Tunnels

Aiming to reduce noise pollution and optimize the acoustic quality in highway tunnels, the noise characteristics on different types of pavements were analyzed and compared in this research, based on the on-site noise measurement in two tunnels with the free fields as a control group. Specifically, the noise characteristics include two aspects: various noise and noise time attenuation performance. Various noise includes on-board sound intensity (OBSI) noise and cabin noise. The noise time attenuation performance uses the indicator of reverberation time. Three types of pavements were measured, including dense-graded asphalt concrete (DAC) and single-layered and double-layered porous asphalt (PA) pavement. The results showed that, for the same type of pavement, compared with the free fields, the difference in OBSI noise in tunnels was within a range of less than 1 dBA; the cabin noise increased by 3.4 dBA~6.6 dBA. The noise level in tunnels was greater than that outside tunnels, and the longer tunnel exhibited higher traffic noise and worse noise time attenuation performances. For the same tunnel, PA pavement could reduce the cabin noise by 3.8 dBA~6.7 dBA. PA pavement also exhibited shorter reverberation time. The application of PA pavement could effectively improve the acoustic quality in the tunnel. This research contributes to noise pollution abatement and the improvement of the comfort and safety of drivers in tunnels.

Interactions of nitrogen and phosphorus in plant nutrition - Analysis of a 60-years old field experiment

Abstract Background and aims The aims are to determine to which extent different plant species increase nitrogen (N) acquisition in response to phosphorus (P) addition and P acquisition in response to N addition as well as to analyze resulting nutrient limitations. Methods The field experiment is replicated at ten sites in Sweden and comprises three fertilization regimes (low, medium, and high) each consisting of a control and a N, P, and NP treatment. Yields as well as N and P contents of the yields of four species (winter wheat, spring barley, oat, and sugar beet) were analyzed over 60 years. Results The relative increase in yield P in response to N fertilization was larger than the relative increase in yield N in response to P fertilization for three species. Synergistic NP co-limitation was observed for all species at some sites. The synergistic growth effect in response to NP addition occurred at more sites at high than at low fertilization. At one nutrient-poor site, all species in all fertilization regimes were (synergistically) NP co-limited. Sugar beet was (synergistically) NP co-limited at all sites in all fertilization regimes. Conclusion Species differed in nutrient acquisition, but most species used added N more effectively to acquire P than they used added P to acquire N. Synergistic NP co-limitation was observed for all plant species at some sites, and it increased with fertilization rate, which is likely due to the limits to which plants can use N to acquire P and P to acquire N.

Optimizing Optoelectronics Performance: Theoretical and Experimental study on ZnO Thin Film for Al/ZnO/p-Si Photodiode

Abstract In this study investigates the optimization of ZnO thin film photoelectric devices, specifically focusing on ZnO/p-Si heterojunction photosensitive devices and photodiodes (PDs) using Al contacts. Through an experimental and theoretical analysis approach aims to evaluate the effects of important parameters, including ZnO layer thickness, defect density, and contact materials, on PD’s efficiency. Numerical analysis simulations comparatively examine the experimentally fabricated device performance at a 5 nm ZnO layer thickness by balancing photon absorption and carrier formation while minimizing carrier transport limitations. Experimentally process, an Atomic Layer Deposition (ALD) system was used to grow ZnO interlayers on one side of the polished Si wafer. Then, Al metallic contacts were created on the ZnO layers using a hole array mask. The PDs were then subjected to electrical characterization using I-V and I-t measurements under various illumination densities. Al/ZnO/p-Si PD's device with active performance has been produced and analyzed with electrical parameters such as barrier height, photocurrent, spectral response, ideality factor and EQE were derived, analyzed and studied. In conclusion, this work provides a comprehensive understanding of the performance of Al/ZnO/p-Si PD at varying illumination intensities and offering a detailed analysis of key parameters influencing device efficiency for future optoelectronics applications.

Understanding Residual Stress Evolution in Directed Energy Deposition With Interlayer Deformation

Abstract Control of residual stresses (RS), inherent to fusion-based additive manufacturing (AM), process is important for the satisfactory mechanical performance of components. Recent work has attempted to control the RS profiles in AM components by applying mechanical peening between built layers. During laser powder bed fusion (LPBF), it has been shown that subsequent layer building does not relieve all the peening-induced compressive stresses. In this work, a similar study has been performed on a directed energy deposition (DED) process. It is shown that owing to the vastly different thermal profile in DED compared to LPBF, the compressive RS induced by peening, is completely alleviated during subsequent layer deposition for 316L stainless steel. Irrespective of the magnitude and depth, the peening-induced compressive stresses were not present in the final part. Experimental and numerical analyses revealed that stress relief due to intrinsic heating was insufficient to explain stress relaxation. Rather, the localized heating and constrained expansion from surrounding cold material was the mechanism responsible for strain redistribution and hence stress relaxation.

A low-swelling alginate hydrogel with antibacterial hemostatic and radical scavenging properties for open wound healing

Development of a low-cost and biocompatible hydrogel dressing with antimicrobial, antioxidant, and low swelling properties is important for accelerating wound healing. Here, a multifunctional alginate hydrogel dressing was fabricated using the D-(+)-gluconic acidδ-lactone/CaCO3system. The addition of hyaluronic acid and tannic acid (TA) provides the alginate hydrogel with anti-reactive oxygen species (ROS), hemostatic, and pro-wound healing properties. Notably, soaking the alginate hydrogel in a poly-ϵ-lysine (EPL) aqueous solution enables the alginate hydrogel to be di-crosslinked with EPL through electrostatic interactions, forming a dense network resembling 'armor' on the surface. This simple one-step soaking strategy provides the alginate hydrogel with antibacterial and anti-swelling properties. Swelling tests demonstrated that the cross-sectional area of the fully swollen multifunctional alginate hydrogel was only 1.3 times its initial size, thus preventing excessive wound expansion caused by excessive swelling. After 5 h ofin vitrorelease, only 7% of TA was cumulatively released, indicating a distinctly slow-release behavior. Furthermore, as evidenced by the removal of 2,2-diphenyl-1-picrylhydrazyl free radicals, this integrated alginate hydrogel systems demonstrate a notable capacity to eliminate ROS. Full-thickness skin wound repair experiment and histological analysis of the healing site in mice demonstrate that the developed multifunctional alginate hydrogels have a prominent effect on extracellular matrix formation and promotion of wound closure. Overall, this study introduces a cost-effective and convenient multifunctional hydrogel dressing with high potential for clinical application in treating open wounds.

A modal momentum method for the identification of structural weak links

In order to meet the demands of weak-link identification of mechanical structures in high-precision equipment, this paper introduces the concepts and equations of modal momentum and modal momentum difference ratio (MMDR), as well as an identification method of weak links based on modal momentum. In this method, the modal data of the mechanical structure is acquired first through experimental modal analysis or finite element analysis. The modal momentum of each measured point is calculated based on the modal data and transformed to the global coordinate system. Then, the MMDRs between the measured point with the largest magnitude of modal momentum and its adjacent measured points are calculated. Weak links are judged if the MMDR exceeds a predefined threshold. Twelve different multi-degrees-of-freedom systems incorporating weak links were designed and then identified using the proposed method. The accuracy of identification is up to 100% for these systems. The method was applied to a double pendulum angle milling head of a five-axis numerically controlled machine tool, and the result reveals that the side plate lacks bending stiffness.

The role of schedules of reinforcement in the experimental analysis of social behavior

The role of schedules of reinforcement in the experimental analysis of social behavior

Optimization of optical properties of nanocomposite films incorporating CWO and ITO nanoparticles for energy-saving window applications

Cesium tungsten oxide (CWO) and indium tin oxide (ITO) nanoparticles are potential candidates for application in energy-saving windows. However, most optical studies on these nanocomposite films lack systematic evaluation and design methods. In this work, the optical properties of spherical and cylindrical CWO and ITO nanoparticles under different geometric parameters based on the Lorenz–Mie and T-matrix theories are investigated, and spectral responses of CWO-PDMS and ITO-PDMS windows are calculated by solving the radiative transfer equation (RTE) using the Monte Carlo method. By evaluating and optimizing the geometric parameters of the nanocomposite films, energy-saving windows exhibit excellent optical performance, with a visible light transmittance that meets the indoor needs of the human eye (Tlum is about 0.6), and can shield most near-infrared light, especially CWO-PDMS windows (TNIR=0.04). Finally, a building energy consumption simulation analysis based on Energy Plus is conducted in three different cities: Jinan, Hong Kong, and Singapore. The results indicate that by adjusting the geometric parameters of nanoparticles, energy-saving windows can effectively reduce energy consumption in tropical and subtropical regions. This work provides guidance for the subsequent commercialization and experimental analysis of spectral selective composite films.

Regional Load Forecasting Scheme for Security Outsourcing Computation

Smart grids generate an immense volume of load data. When analyzed using intelligent technologies, these data can significantly improve power load management, optimize energy distribution, and support green energy conservation and emissions reduction goals. However, in the process of data utilization, a pertinent issue arises regarding potential privacy leakage concerning both regional and individual user power load data. This paper addresses the scenario of outsourcing computational tasks for regional power load forecasting in smart grids, proposing a regional-level load forecasting solution based on secure outsourcing computation. Initially, the scheme designs a secure outsourcing training protocol to carry out model training tasks while ensuring data security. This protocol guarantees that sensitive information, including but not limited to individual power consumption data, remains comprehensively safeguarded throughout the entirety of the training process, effectively mitigating any potential risks of privacy infringements. Subsequently, a secure outsourcing online prediction protocol is devised, enabling efficient execution of prediction tasks while safeguarding data privacy. This protocol ensures that predictions can be made without compromising the privacy of individual or regional power load data. Ultimately, experimental analysis demonstrates that the proposed scheme meets the requirements of privacy, accuracy, and timeliness for outsourcing computational tasks of load forecasting in smart grids.