Effect Of Geometry Research Articles

Plasmonic Geometry-Induced Viscoelastic Biocomplex Formation with Optical Concealment, Liquid Slips, and Soundscapes in Bioassays.

Plasmonic nanoparticles (NPs), typically made up of gold or silver, are widely used in point-of-care bio- and chemical sensing due to their role in enhancing detection sensitivity. Key NP properties influencing sensing performance include the material type, NP size, and geometry. While much research has focused on material and size optimization, less attention has been given to understand NP geometry effects and interactions with biomolecules involved in the bioassay. In this context, we investigate the interfacial properties of the biocomplex formed by spherical-shaped gold nanoparticles (AuNPs) and gold nanostars (AuNSts) during a sandwich assay using localized surface plasmon resonance (LSPR) and quartz crystal microbalance with dissipation (QCM-D). The chosen model to study the biocomplex specifically detects interleukin-6 (IL-6). Our results show that AuNSts, with their anisotropic shape and higher surface area, form antibody-antigen complexes more effectively than AuNPs. AuNSts also create a softer, more hydrated layer due to their complex geometry, which leads to larger liquid slips. Lastly, we showed that AuNSts avoid optical concealment at high IL-6 concentrations, unlike AuNPs, making them more reliable for detecting a wider range of concentrations. These findings highlight the importance of optimizing NP geometry for improved bio/chemical sensor performance.

The Effect of Fusion Zone Oxygen Content and Weld Geometry on Hardness and Porosity of Laser-Welded CP Titanium Sheets

The Effect of Fusion Zone Oxygen Content and Weld Geometry on Hardness and Porosity of Laser-Welded CP Titanium Sheets

A high-frequency nanoscale positioner driven by an external electric field: a molecular dynamics study.

The precise localization at the nanoscale plays a crucial role in mass transfer, nanostructure reconstructions, and nanofabrication processes. This study presents a model for a nano-positioner via strain engineering that can be precisely controlled by an external electric field (EF). The model consists of three major components: a graphene kirigami (GK) nanospring for achieving large elastic deformation, a charged carbon nanotube (CNT) connecting the GK, and a graphene substrate for controlling the movement path of the CNT. Upon activation of the EF, the charged CNT moves along the substrate, stretches the GK, and eventually settles at a desired position after undergoing damped oscillations. When turning off the EF, the CNT returns to its initial position. Molecular dynamics simulations are employed to evaluate the safety, stability, precision, and response speed of this system in a pulsed EFs while taking account of GK geometry and EF mode effects. Within a certain range of EF intensity, this nano-positioner operates safely with tunable positioning capability while maintaining high precision and response speed. Furthermore, this nanosystem can work smoothly at gigahertz in a pulsed EF.

Effect of contact geometry, loading, material properties and relative slip on the fretting fatigue behaviour of metallic components

Effect of contact geometry, loading, material properties and relative slip on the fretting fatigue behaviour of metallic components

Effect of Nozzle Geometry on Erosion Characteristics in Abrasive Water Jet: Experimental and Numerical Analysis

Effect of Nozzle Geometry on Erosion Characteristics in Abrasive Water Jet: Experimental and Numerical Analysis

An Experimental Study of the Pull-In Voltage in RF MEMS Switches Fabricated by Au Electroplating and Standard Wet Release: Considering the Bridge Geometry

Radio Frequency Micro Electro Mechanical Systems (RF MEMS) are devices showing exceptional potential to satisfy the demands of emerging RF electronic technologies, including those considered for high-power applications, such as for long distance communication systems. Operation in this regime requires an alternative way of thinking for these devices and, for example, a more accurate control of the pull-in voltage is of major importance due to the self-actuation effect. Therefore, the studies focusing on the features of the moving bridges are of great importance. This work presents the fabrication of a full family of RF MEMS switches suitable for high-power implementations having bridges deposited by Au electroplating and released using purely standard wet processes, as well as a carefully designed experimental study of their pull-in voltage. Depositing the bridge of the high-power RF MEMS by using only a single electroplating step makes the device fabrication easier, whilst the utilization of a purely wet release process is an asset. This method relies on low temperature processes, applicable simultaneously in bridges with various geometrical and perforation details without the need of any specialised infrastructure. The experimentally obtained results suggest that for this technology the bridge thickness is a critical factor for controlling the pull-in characteristics between devices fabricated in the same run. Moreover, it is revealed that for thicker bridges, geometry and hole perforation effects are more pronounced. This technology is therefore suitable for developing RF MEMS where the bridge thickness could be potentially utilized for enabling optimization engineering between devices that should be fabricated in the same run but need to satisfy diverse specifications during their operation.

Effect of Tooth Geometry on Multi-cycle Meshing Temperature of POM Worm Gears: Parametric Study via an Adaptive Iteration Algorithm

Meshing temperature analyses of polymer gears reported in the literature mainly concern the effects of various material combinations and loading conditions, as their impacts could be seen in the first few meshing cycles. However, the effects of tooth geometry parameters could manifest as the meshing cycles increase. This study investigated the effects of tooth geometry parameters on the multi-cycle meshing temperature of polyoxymethylene (POM) worm gears, aiming to control the meshing temperature elevation by tuning the tooth geometry. Firstly, a finite element (FE) model capable of separately calculating the heat generation and simulating the heat propagation was established. Moreover, an adaptive iteration algorithm was proposed within the FE framework to capture the influence of the heat generation variation from cycle to cycle. This algorithm proved to be feasible and highly efficient compared with experimental results from the literature and simulated results via the full-iteration algorithm. Multi-cycle meshing temperature analyses were conducted on a series of POM worm gears with different tooth geometry parameters. The results reveal that, within the range of 14.5° to 25°, a pressure angle of 25° is favorable for reducing the peak surface temperature and overall body temperature of POM worm gears, which influence flank wear and load-carrying capability, respectively. However, addendum modification should be weighed because it helps with load bearing but increases the risk of severe flank wear. This paper proposes an efficient iteration algorithm for multi-cycle meshing temperature analysis of polymer gears and proves the feasibility of controlling the meshing temperature elevation during multiple cycles by tuning tooth geometry.

Investigating the Effect of Morphology on Nanoparticle Catalyst Reactivity: Example of Anthraquinone Hydrogenation

AbstractNowadays, nanomaterials are central in modern technology, finding applications in a huge variety of scientific fields, such as catalysis. Besides their chemical nature, their morphology also appears to play a key role in catalytic processes. Although this effect has been extensively observed in literature, no fundamental explanation has been provided yet. In this work, taking anthraquinone hydrogenation on Pd as a model process, we used density functional theory (DFT) computation to address the particle shape effect. Based on previously published experimental results, we compared the catalytic properties of cubic and octahedral nanoparticles, considering different facet orientations and edge defects to simulate geometry and the size influence. We were able to correlate the morphological impact on the surface activity and selectivity with electronic charges of various intensities, induced at the material topmost layer by the cubic shaped‐design, especially close to edges. Such an inequal charge distribution, differently affects the stability of the reaction intermediates according to their polarizability. Besides offering for the very first‐time theoretical insights to understand the surface geometry effect on reactivity, this work is expected to have practical implications for experimentalists in the rational design of efficient solid catalysts in many areas of the chemical industry.

Fabrication and Characterization of Metallic Glass Nanowire-Anchored Microfluidic Channels

Abstract Nanowire-based microfluidic devices combine the strengths of microfluidics and nanostructures for applications in cell biology and chemical sensing. However, their use has been limited by the complexity of the fabrication methods. In this study, we present a simple approach for fabricating and integrating metallic glass nanowires into microfluidic channels. Metallic glass nanowires were formed by thermoplastic drawing on a silicon substrate. The silicon-anchored nanowire array was sealed with a polydimethylsiloxane (PDMS) channel to create a nanowire-integrated microfluidic device. The effect of nanowire geometry on the flowrate was characterized. The experimental results were compared with computational fluid dynamics (CFD) simulations to understand the fluid–nanowire interaction. The potential of surface modification to functionalize the metallic glass nanowires was evaluated.

Solute Delivery Through a Porous-Walled Microtube With Sinusoidal Roughness by Electroosmotic Pumping.

This study investigates the delivery of a neutral solute through a porous-walled microtube with sinusoidal roughness under mixed electroosmotic flow pumping, using an external direct current electric field. The effects of various operating conditions, geometries, and properties of the wall, solute, and solvent are investigated. The novelty of this work lies in exploring the impact of sinusoidal roughness on the solute mass flux delivery. It is found that a higher relative roughness amplitude (𝛿=0.1) and roughness wavenumber (𝜆=12) decrease the average cross-sectional velocity by up to 31% by judiciously tuning the parameters for better solute delivery. The effects of roughness parameters (𝛿, 𝜆), tube length ( , mean tube diameter ( pump flow rate electric field strength ( wall permeability ( , trans-wall pressure drop ( ), real retention ( , solute diffusivity , and osmotic pressure coefficient on the solute permeation mass flux are quantified. Among these parameters, the effect of is the most dominant in increasing the solute permeation flux of the rough-walled microtube, compared to the smooth wall. For example, by changing from 5 to 20kPa, the enhancement is about 16% in assisting flow and 19% in opposing flow. It is anticipated that the results of this study will provide valuable design perspectives for customized drug delivery systems using microfluidic channels, as well as enhance the understanding of nutrient transport in biological systems.

Impact of Channel Geometry and Operating Temperature on the Performance of Solid Oxide Electrolyzer Cells: A Study of Uniform and Non-Uniform Temperature Effects

This study investigates the effects of channel geometry and operating temperature on the performance of Solid Oxide Electrolyzer Cells (SOECs), a promising technology for efficient hydrogen production. Through computational simulations and experimental analysis, we explore the impact of different channel designs—rectangular, triangular, and semicircular—on system efficiency. Among the geometries, rectangular channels deliver the highest performance, with a 10% efficiency improvement over the others. Additionally, increasing the operating temperature from 1073 K to 1273 K accelerates reaction kinetics, yielding a 15% efficiency gain. The study identifies the optimization of both channel design and temperature as crucial for maximizing hydrogen production. Furthermore, the research finds that non-uniform temperature distribution has minimal impact on performance for the small-scale fuel cell configuration used. These findings emphasize the importance of understanding the interplay between geometry and operating conditions in SOEC design and contribute to the advancement of sustainable hydrogen production technologies.

A meshless method for thermal vibration analysis of curved-edge trapezoidal plates made of laminated materials

Abstract This paper reports a meshless method for stochastic vibration analysis of trapezoidal composite laminates with curvilinear bound. The basis functions used in this meshless method are Chebyshev polynomials, which are adapted to the defining domain of the Chebyshev polynomials by transforming the curved-edge plate into a square plate using a coordinate mapping technique. The developed vibration analysis model combines the first-order shear deformation theory (FSDT) and thermos-elasticity theory using the Hamiltonian variational principle. The displacement tolerance function of the square plate is approximated by a two-dimensional meshless Chebyshev-radial basis point interpolation method. Gaussian Lobato sampling points are used to discretize the square domain. The correctness and efficiency of the model is verified by comparison with finite element results and published literature. The effects of temperature, geometry, and stochastic loading on the vibration characteristics of curved edge trapezoidal plates are also carried out. The results show that the existing Chebyshev-radial basis point interpolation method can accurately and efficiently calculate the vibration characteristics of curved-edge trapezoidal plates under different boundary conditions.

Metallic Metamaterials for Reducing the Magnetic Signatures of Ships

In this study, the magnetic signatures of ship structures were investigated. The magnetic signature impacts both navigation safety and the health of the marine ecosystem. Reducing this signature is essential for minimising risks associated with navigation and protecting marine biodiversity. A finite element model was developed to assess the magnetic signature of honeycomb sandwich panels for ship structures. A theoretical approach was proposed, and the predicted results were compared with the values obtained by the finite element analyses. Different types of structures were compared to evaluate the combined effect of materials and geometry on the magnetic signature. The finite element results and the theoretical predictions indicate that the use of metamaterial structures, consisting of honeycomb sandwich panels with a steel core and aluminium skins, produces a significant reduction of the ship magnetic signature compared to the one arising from a steel panel with the same bending stiffness.

Effects of break geometry and orientation on helium-air mixing in simulated reactor cavities of high temperature gas reactors

Effects of break geometry and orientation on helium-air mixing in simulated reactor cavities of high temperature gas reactors

Study on the effects of nozzle orifice geometry and pulsed injection frequency on transverse jet atomization and total pressure loss in a supersonic crossflow

Study on the effects of nozzle orifice geometry and pulsed injection frequency on transverse jet atomization and total pressure loss in a supersonic crossflow

The effects of ventricle geometries and boundary conditions on computational modeling of ventriculoperitoneal catheters.

The effects of ventricle geometries and boundary conditions on computational modeling of ventriculoperitoneal catheters.

Characterization of 3D printed micro-blades for cutting tissue-embedding material.

Characterization of 3D printed micro-blades for cutting tissue-embedding material.

The effects of optimized rim seal geometry on the end wall flow of a high-lift low-pressure turbine

To reduce the secondary flow losses of a high-lift low-pressure turbine, a new contour method for the rim seal geometry is proposed in this paper. The numerical simulation and experiment are used to investigate the effects of different rim seal geometries on secondary flow losses at the end wall. The total pressure loss coefficient at the cascade outlet serves as the optimization objective, and the rim seal geometry coupled with the hub of the cascade leading edge is optimized using the radial basis function–genetic algorithm method. The results indicate that compared with the straight rim seal geometry, the optimized rim seal geometry reduces the strength of passage vortex (PV) and corner vortex, and the additional secondary flow losses caused by sealed flow are reduced as well. At three different seal mass flow ratios, the optimized geometry changes the structure of the secondary flow vortices at the end wall. The optimized geometry splits the shear-induced vortex (SIV) into SIV1 and SIV2. The formation and development of SIV1 are suppressed, resulting in the horseshoe vortex pressure-side leg merging with SIV1 to reach the suction surface position further downstream. Meanwhile, SIV2 counteracts the horseshoe vortex suction-side leg in the cascade passage, inhibiting the formation and development of PV. The optimized geometry changes the development of the vortex structure at the leading edge of the cascade by changing the characteristics of the purge flow, thus reducing the strength of PV and improving the aerodynamic performance at the end wall.

The effects of pore shape and geometry on the storage of CO2 in mesoporous media

The effects of pore shape and geometry on the storage of CO2 in mesoporous media

Combined effect of chamber geometry and compression ratio on the combustion process in a methanol-enriched rotary engine

Combined effect of chamber geometry and compression ratio on the combustion process in a methanol-enriched rotary engine