bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Fabrication of an Upper Limb Exoskeleton for Shoulder and Elbow Assistance With Four Actuated DOFs
Authors: Truong Andrew , Sharifi Mojtaba 
Published: January 2025

Abstract
People who have physical deformities or suffer the long-term effects of a stroke or spinal injury depend on assistive devices to help with daily activities. Over the years, there have been adequate advancements in the overall design of upper limb exoskeletons, with current models having more degrees of freedom (DOF) than before. More DOF is beneficial as it allows the limb to move more naturally. Despite great advances, current models on the market are large, bulky, and heavy. They are difficult to move and are often stationary. This study aims to improve the design of an existing portable upper limb exoskeleton by adding more DOF and making it as light and simple as possible without compromising performance. There will be a total of four DOFs, three dedicated to the shoulder joint and one for the elbow joint. The three main assemblies that make up the composition of the exoskeleton are the main linkage for the forearm and upper arm, the gimbal mechanism, and a motor assembly arranged on a carbon fiber back plate. Using telescopic aluminum bars, the links can be adjusted to accommodate different body types. A combination of Bowden cables and pulleys was used to reduce the inertia and weight of moving parts. The structural integrity of the exoskeleton was validated by performing Finite Element Analysis (FEA) for applied loading and fatigue on what were deemed critical components: pulley housing, back plate cable housing, and the angled links. The results show that there was a minimum displacement of 0.0986 mm and 0.0431 mm in the pulley housing and the back plate cable housing, respectively. Fatigue analysis was performed on critical components. All critical components have a factor of safety (FOS) of greater than 1.5.
Economically Viable Plastic Recycling to Produce Additive Manufacturing Feedstock Using Waste Bottles for Circular Economy
Authors: Al Rashid Ans , Koç Muammer 
Published: January 2025

Abstract
The pursuit of sustainable practices in manufacturing has become increasingly imperative in addressing environmental concerns and resource scarcity. One promising avenue is using waste materials within a circular economy framework. This paper presents an economically viable 3D-printed setup for additive manufacturing feedstock using waste bottles. The process begins with collecting and preparing waste bottles, which are sorted, cleaned, and cut into uniform strips suitable for extrusion. The plastic strips are transformed into filaments using a hotend volcano nozzle suitable for use in 3D printers. This approach effectively demonstrates the principles of a circular economy, where waste is converted into a resource. Utilizing 3D printing technology allows for the fabrication of custom components at a relatively low cost, minimizing the initial investment required for implementation. By maximizing resource utilization and minimizing energy consumption, the setup reduces operational costs and enhances its overall sustainability. The proposed 3D-printed setup offers a practical and cost-effective solution for producing additive manufacturing feedstock from waste bottles within a circular economy framework. Repurposing waste materials into valuable resources addresses environmental and economic challenges, contributing to the transition towards a more sustainable future.
Vibration Transmission Characteristics of Multi-Materials With Hard and Soft Layers Utilizing Photo-Patterning Polymerization
Authors: Inoue Tatsuya , Fukuno Koichi , Fukunishi Haruka , Terashima Osamu , Hayashi Mikihiro , Yamada Shuho 
Published: January 2025

Abstract
This study investigated the vibration reduction effects of polymer materials with hard and soft layers, designed to mimic the surface shapes and characteristics of plants and animals. Initially, numerical analysis using the finite element method was conducted to determine the number of soft layers. The results revealed that having four or nine soft layers could provide a high vibration-reduction effect. Based on these findings, prototype polymer materials were created and tested for their vibration reduction effects by using a shaker. Polymer materials with either four or nine soft layers exhibited a significant vibration reduction, indicating that the effect depended on the number of soft layers. It was also found that this polymer material is effective in reducing the vibrations transmitted to the soles of passengers’ feet while they are inside a vehicle and that these vibrations are caused by road inputs during vehicle driving. It was found that designing hard and soft layers with appropriate values for the number of soft layers may be an effective method for reducing vibrations over a wide range of frequencies.
Exploring the Influence of Acetone Vapor Processing and Subsequent Drying Methods on the Fatigue Performance of 3D Printed ABS Parts
Authors: Bae Heechang , Rada Eric , Scheff Tyler , Michaelis Matthew , Hossain Awlad 
Published: January 2025

Abstract
Fused Deposition Modeling (FDM), a method in additive manufacturing and 3D printing, is extensively utilized where materials are melted, extruded, and layered to fabricate a desired object. Recently applications of FDM technologies have surged extending not only to rapid prototyping but also to the mass production of finalized products. Components in 3D printing are often formed in distinct layers which inherently introduces structural unpredictability due to discontinuities, voids and insufficient inter-layer adhesion. In earlier research we effectively explored the discrepancies in ultimate strength and fatigue life among 3D printed Acrylonitrile Butadiene Styrene (ABS) components crafted with various build/layer orientations. That research successfully underscored the ultimate strengths and fatigue life including SN Curves. Nonetheless there is a pressing necessity for additional research aimed at enhancing the fatigue life of the 3D printed ABS components. This study explores the impact of surface treatment on the fatigue life of 3D printed ABS components across various layup orientations. Herein the Acetone Vapor Smoothing (AVS) method was employed as the surface treatment for the components. Our findings indicate that the AVS method can mitigate stress concentrations on the surface and structural uncertainty in the 3D printed ABS components thereby amplifying fatigue strength. These findings, however, were attained after manipulating Acetone vapor exposure and optimizing drying procedures since Acetone compromised the layer bonding of the ABS diminishing its tensile strength and fatigue life. This research outlines the optimal conditions for Acetone Vapor exposure time and drying procedure.
Modelling and Simulation of Solenoid Driven Electro-Pneumatic Actuator
Authors: Ercis O. Fatih 
Published: January 2025

Abstract
This paper presents the modelling and simulation of a servo electro-pneumatic actuator utilizing solenoids. Many control actuation systems employ electro-hydraulic or electro-mechanical servo actuators. However, electro-pneumatic servo actuators using solenoids are becoming more popular due to their lower cost and simpler structure. Pneumatic actuators are preferred due to their low cost, simple structure, fast response, low electromagnetic interference, high force/weight ratio. In this study, poppet type on-off solenoid valves, driven by pulse width modulation (PWM), are used to achieve servo control of the pneumatic actuator. A feedback sensor is attached to the output shaft of the actuation mechanism. The actuator is powered by a pressurized gas tank, with gas pressure regulated by a pneumatic pressure regulator. Both non-linear and linear mathematical models of the pneumatic actuator are developed and compared at a specific operating point using MATLAB/Simulink software. Furthermore, a closed loop servo system is established in Amesim simulation environment. The detailed models of the solenoid valve, friction, and pneumatic pressure regulator are implemented in the Amesim model. The simulation results reveal the non-linear behavior of the compressed gas. Additionally, the 3dB bandwidth is calculated to be 23 Hz. Beyond this frequency, unpredictable harmonic motions are observed.
Characterization of Energy Dissipation and Material Failure Mechanisms In High-Velocity Impact of Magnesium Alloys
Authors: Jin Rong , Sun Xingsheng 
Published: January 2025

Abstract
High-velocity impact analysis is crucial in defense, aerospace, and materials science, involving scenarios ranging from projectiles hitting land vehicles to supersonic aircraft traveling in dusty environments. This work presents a detailed computational analysis of high-velocity impacts using the Smoothed Particle Hydrodynamics (SPH) method. Impact events include a stainless steel projectile against a magnesium alloy target plate, with impact velocities ranging from 1.2 km/s to 2.4 km/s. We employ carefully calibrated plasticity, fracture, and equation of state models to characterize the behaviors of both projectile and target over a wide range of strain rates and temperatures. Our simulation results include the evolution of the von-Mises effective stress and temperature fields at different impact velocities. Several key material failure mechanisms are observed, such as spalling and adiabatic shearing. We partition and quantify the dissipation of the impact kinetic energy into the kinetic and internal energies of both the projectile and the target. Finally, we analyze the time histories of the corresponding proportions during the impact events and the distributions of energies across all material points at key time points. We find that at all impact velocities, the target’s kinetic energy peaks when the shock wave reaches the back face and stabilizes after complete penetration. As the impact velocity increases, the kinetic energy of the target and the internal energy of the projectile contribute more significantly to the dissipation of the impact energy, while the contribution of the target internal energy decreases.
Heat Transfer of High-Temperature in Rotating Aerocraft Jet Engine Turbine Blades
Authors: Amano Ryoichi S. 
Published: January 2025

Abstract
Pin-fin is an excellent structure to insert in the narrow trailing edge of a gas turbine blade to achieve effective cooling. The optimization of the pin-fin design is important to finding the optimal pressure drop. The present study considers two different pin-fin designs, i.e., partial spherical and dome shapes with different pin-fin arrays. The experimental and simulation studies were performed with different rotation numbers. The experimental study with different Reynolds numbers was completed. A computational study was conducted with a simulation. The investigation was completed based on the cooling channel’s heat transfer coefficient, friction factor, and thermal performance. The cooling channel with dome-shaped pin-fins showed better thermal performance than other cooling channels.
Mechano-Bactericidal Surfaces Fabricated by Inverted Glancing Angle Deposition (I-GLAD)
Authors: Qu Chuang , Walsh Kevin 
Published: January 2025

Abstract
This paper explores the nanofabrication of mechano-bactericidal antimicrobial surfaces using inverted glancing angle deposition (I-GLAD). Inspired by natural mechanisms, needle-like structures are employed to eliminate microbes by rupturing them upon contact, thereby preventing the development of antimicrobial resistance. However, creating artificial mechano-bactericidal antimicrobial surfaces presents challenges due to the intricate three-dimensional nanofeatures involved. Leveraging the capabilities of Inverted-Glancing Angle Deposition (I-GLAD), an advanced physical vapor deposition technique, this work aims to produce large-area surfaces featuring sub-10 nm tip-sized nanoneedles for mechano-bactericidal purposes. Compared to conventional nanofabrication techniques, the I-GLAD process offers a cost-effective and time-efficient approach to creating such antimicrobial surfaces. The manuscript discusses the inverting ability of the process, highlighting the necessity of a maximum incident angle of over 79 degrees for successful inversion, as demonstrated by tape testing results. Furthermore, by incorporating transparent materials (such as SiO2) in the I-GLAD process, the nanoneedle structures act as a transitional medium between air and the parylene substrate, effectively reducing surface reflection and rendering the antimicrobial surfaces transparent. Experimental tests confirm the transparent nature of these surfaces. Both opaque and transparent I-GLAD films hold promise for diverse applications across various fields in our daily lives.
The Study of Hyperparameters in the Prediction of Remaining Useful Life
Authors: Gandur Nazir Laureano , Ekwaro-Osire Stephen 
Published: January 2025

Abstract
Despite the extensive body of literature on RUL prediction techniques, there is still a need to understand how hyperparameters affect these predictions’ error and aleatoric and epistemic uncertainty. Motivated by this need, the research question was: Does applying machine learning architecture enhance uncertainty quantification in RUL prognostics? Two objectives are pursued to address this question: first, to analyze the impact of hyperparameters on modeling the data, and second, to explore the temporal propagation of the hyperparameters’ influence on RUL.
To achieve these objectives, this research leverages vibration data obtained from experiments conducted on bearings. Employing a neural network framework, the study quantifies uncertainty in RUL prediction. Different hyperparameters were studied to determine how they affect uncertainty and error. Furthermore, the paper goes to the temporal analysis of hyperparameter impact by delving into the dynamics of these influences over time and examining how the hyperparameter effect propagates, as represented by a probability density function of RUL. The hyperparameter analysis reveals how different settings influence the model’s uncertainties and error metrics. Finally, it was determined that the selection of an optimizer is critical when developing RUL prediction models for predictive maintenance tasks.
Digital Shadow-Based Detection of Blockage Formation in Water-Cooled Power Electronics
Authors: Hainey Richard , Priddy Braden , Sado Kerry , Downey Austin R. J. , Khan Jamil , Fought Haskell , Booth Kristen 
Published: January 2025

Abstract
In maintaining the quality of coolant within water-cooled electronic systems, attention must be given to potential blockage formations. These blockages typically occur when suspended particulates form deposits within component chambers, leading to restricted flow, which can result in overheating issues, decreased performance, and cooling failure. To address this, a thermal digital shadow has been designed and validated to accurately simulate and detect blockage formation within the cooling system of a real-world physical twin. During operation, the digital shadow characterizes system parameters — flow rate, initial temperatures, individual components, and waste heat production — from the physical twin to more accurately replicate system characteristics. For validation, simulated blockages are created in the physical twin and digital shadow, and the results are compared. At 50% blockage, a significant temperature surge is observed, with subsequent surges increasing as the blockage develops, the largest occurring at 87.5% blockage formation. The data gathered shows how a digital shadow can support real-time monitoring and predictive maintenance, enabling proactive interventions to prevent thermal accumulation from damaging the affected components. Serving as the groundwork for future development, this digital shadow system can assist in creating a robust digital twin system for blockage detection and decision-making within water/liquid-cooled electronic systems.
A Study of Optimal Mesh for Computational Fluid Dynamics in Cerebral Aneurysms
Authors: Garigapuram Prithvinath Reddy , Katore Srushti 
Published: January 2025

Abstract
A cerebral aneurysm is a cerebrovascular condition affecting about 3 to 5 percent of the population, posing significant health risks. Rupture can result in death, with aneurysms greater than 7mm considered high risk and those less than 3mm low risk. However, size alone doesn’t determine rupture risk; location, shape, and individual health also play crucial roles. Computational fluid dynamics (CFD) analysis has advanced preventative medicine by providing valuable insights into aneurysm growth, rupture risk, and behavior, aiding early diagnosis and treatment. The accuracy of CFD depends on mesh quality in capturing flow properties. Improper meshing introduces challenges like lack of mesh independence and artificial flow disturbances, impacting accurate hemodynamic assessment. Computational costs increase with mesh size without necessarily improving accuracy due to numerical instability. Thus, meticulous meshing is crucial for reliable CFD simulations. This study investigates meshing effects on CFD results using ANSYS 2023 R2 Fluent with polyhedral meshes. A comparative study of five patient models assesses the impact of varying mesh quality on simulation accuracy. Uniform boundary conditions (blood pressure 120/80 mm Hg, healthy velocity inputs) are used to evaluate flow dynamics, wall shear stress (WSS), and pressure distribution, establishing an efficient and accurate simulation approach for aneurysm modeling.
Transient Evolution of Interface and Temperature in Twin Roll Casting Process Using Coupled Phase Field and Thermo-Fluid Model
Authors: Soni Akshay , Bag Swarup , Robi P. S. , Amin M. Ruhul 
Published: January 2025

Abstract
A The production of thin strips by utilizing twin roll casting process requires proper control over process parameters. Excellent quality of the strip is only visible when process is operated under steady state condition. However, defects such as porosity, irregularities in strip surface, and frequent breakage in strip are observed during the process. These defects arise prominently due to unstable liquid metal-air interface during initial transient stage of the process. The stability of the interface can be tailored by selecting process parameter that consequently mitigates the possibilities of defects. The current study focuses on the transient evolution of liquid metal-air interface during the initial stage of the process. A two-dimensional transient coupled thermo-fluid model using phase field is devised for investigating free surface profile of the liquid melt and possibility of air entrapment within the liquid metal. In addition, growth of solidified shell, time required to stabilize the exit surface temperature, and thermal profile are also incorporated in the study. The investigation of the process indicates that higher casting and inlet melt velocity creates unstable interface. Hence to obtain stable and gradual formation of interface, optimum casting speeds with low inlet melt velocity is proposed.
Morphokinematic Impacts on Hydrodynamics and Performance of Tuna-Inspired Robots
Authors: Kelly John , Zhu Joe , Bart-Smith Hilary , Dong Haibo 
Published: January 2025

Abstract
Many recent developments have been made in the performance of bioinspired underwater vehicles, however, there is still a significant performance gap between the high-performing fish in nature and their engineered counterparts. A multitude of parameters govern performance in biological fish swimming, including the morphology of the fish and the kinematics of the swimming motion. In this research, we utilize computational fluid dynamics to study the effect of morphological and kinematic parameters on the performance and hydrodynamics of Tunabot Flex, a high-performance tuna-inspired robotic platform. A reconstructed virtual model is used for fluid simulations, completed with an in-house immersed boundary method-based direct numerical flow solver. Results characterize the flow of the Tunabot flex platform, including thrust generation and vortex wake analysis. The effects of the body thickness on the performance are studied, revealing a critical flow separation mechanism that accelerates the detriment resulting from a wider body. Finally, the kinematics are varied by adjusting the virtual joint angles corresponding to the real Tunabot flex joints. These results allow for a better understanding of body flexibility, morphological, and kinematic parameters and their role in Tuna-like locomotion, allowing for better-informed engineering design.
Time-Dependent Solution of Unsteady Compressible Flow Equations for Nanoscale Heat and Mass Transfer in Wide-Ranging Diverse Applications
Authors: Sinha Ramlala P. 
Published: January 2025

Abstract
A new innovative stable time-dependent compressible flow solution over the order of nanoseconds is provided here for wide-ranging critically important challenging applications. Specifically, a solution of the highly complex unsteady high speed oscillating compressible flow field inside a cylindrical tube, closed at one end with a piston oscillating at very high resonant frequency at the other end, has been obtained numerically, assuming one dimensional, viscous, and heat-conducting flow, by solving the appropriate fluid dynamic and energy equations. An iterative implicit finite difference scheme is employed to obtain the solution. The scheme permits arbitrary boundary conditions at the piston and the end wall and allows assumptions for transport properties. In successfully predicting the time-dependent results/data, an innovative simple but stable solution of unsteady fluid dynamic and energy equations is provided here for wide ranging research, design, development, analysis, and industrial applications in solving a variety of complex fluid flow heat transfer problems. The method is directly applicable to pulsed or pulsating flow and wave motion thermal energy transport, fluid-structure interaction heat transfer enhancement, nanoscale heat and mass transfer, diverse range of advanced fluidics, biofluidics / bioengineering, and fluidic pyrotechnic initiation devices. It can further be easily extended to cover muzzle blasts and high energy nuclear explosion blast wave propagations in one dimensional and/or radial spherical coordinates with or without including energy generation / addition terms. No other solution exists for such applications.
The Fabrication Process of Surface Acoustic Wave (SAW) Devices Using Maskless Photolithography With a Validation of Traditional Masked Photolithography for Microfluidic Applications
Authors: Parvez Mohammad Salman , Hussain Shadhin , Young Chadwin , Lee Jeong-Bong 
Published: January 2025

Abstract
IDT (Interdigitated Electrodes or Transducers) fabricated Surface Acoustic Wave (SAW)-based devices have been popularly used in microfluidic applications. The mask-based photolithography system is commonly used for fabricating IDTs on SAW devices. But the process does not provide much freedom for changing the design, once the mask is made. On a different note, Lithium Niobate (LiNbO3)is very fragile and brittle which can be broken or can induce stress that may impact the piezoelectric properties due to hard contact of the Chromium mask during UV exposure. A novel maskless photolithography process is introduced for such devices to mitigate these limitations. In terms of cost, this maskless approach is cheaper than creating a new mask each time for a change in design parameters. This process is also suitable for the “lift-off” and “etching” techniques regardless of “Bright-field” or “Dark-field” masks with the same computer-aided drawing (CAD). In this study, the dosage rate has been estimated for the maskless process by converting the dosage parameters from the masked photolithography process. Finally, the devices made by the maskless photolithography process have been characterized with a Vector Network Analyzer (VNA), and the results are validated through comparison with the conventional mask-based photolithography process.