bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deconvolution of Atomic Force Microscopy Data From the Effects of Destructive Indentation in Soft Material Systems
Authors: Westby Maximillian , Yekani Fard Masoud , Norkus Tyler , Boutin William 
Published: January 2025

Abstract
Atomic force microscopy (AFM) is a crucial tool for nanoscale material characterization of soft materials. However, AFM data is easily convoluted by many real, non-ideal artifacts. Researchers have identified some of them and developed techniques to deconvolute AFM data. Yet, several effects remain poorly understood. One of these effects has been identified as destructive AFM indentation. In particle-matrix composites, hard particle inclusions are responsible for varying degrees of stiffness across the sample, making nondestructive AFM indentation challenging. This paper utilizes finite element analysis (FEA) and AFM to study the impact of polymer matrix damage caused by destructive indentation on AFM data. AFM indentation is simulated on a polymer matrix FE model at varying depths. The Derjaguin-Muller-Toporov (DMT) contact model is validated for the FE geometry and applied to probe-matrix interactions for small indentation depths. Experimental data from AFM performed on PNCs reinforced with 0.5 wt.% multi-walled carbon nanotube (MWCNT) and CNT buckypaper (BP) is used to supplement FEA. Force-displacement data obtained through FEA is used to determine the indentation force and yield strength at the nanoscale following Hertzian contact theory and Tresca’s yield criterion. Subsequent destructive indentations are simulated to study their effect on force-displacement data.
Assessment of Refrigerant Management Practices in Automotive Air Conditioning Service Centers: Compliance, Challenges, and Environmental Implications
Authors: Galindo Ronald M. 
Published: January 2025

Abstract
The unintentional or intentional venting of refrigerants into the atmosphere by automotive air conditioning service centers instead of utilizing refrigerant recovery equipment poses a significant threat to the ozone layer, in accordance with the Montreal Protocol, Environmental Protection Agency (EPA) regulations, and Republic Act 8749 (R.A. 8749), also known as the “Philippine Clean Air Act.” This study assesses the refrigerant management practices within accredited automotive air conditioning service centers in Metro Cebu, Philippines, focusing on operations, awareness, and compliance with environmental regulations. Using a descriptive survey technique, the assessment covers various areas of refrigerant management, including sourcing, handling, storage, inventory, recovery, recycling, reclamation, equipment, and parts disposal. The findings indicate that while accredited automotive air conditioning service centers in Metro Cebu demonstrate partial compliance with operational standards such as quality, process efficiency, capacity management, inventory control, and workforce competence, there exist significant gaps in compliance with EPA and R.A. 8749 guidelines. Specifically, refrigerant management practices related to sourcing, handling, storage, inventory control, recovery, recycling, reclamation, and equipment and parts disposal are not fully implemented in accordance with regulatory standards.
Vibrational Analysis of Additively Manufactured 3D Printed Metal Beams With Multiple Void Defects
Authors: Shaheen Samaher , Lloyd-Harry Sam , O’Connor Dennis M. 
Published: January 2025

Abstract
Additive manufacturing (AM), also known as 3D printing, has transformed aerospace, automotive, and energy industries, enabling the production of specialized components that with traditional methods, would not be possible. In the oil and gas industry, AM provides transformative benefits, including designing unique parts with complex geometries, such as advanced turbines or valves, that increase efficiency and resilience, while reducing lead times and costs. Internal defects in 3D metal printing can compromise structural integrity, leading to equipment failure and operational disruptions. Therefore, it is crucial to identify internal defects in 3D metal printed parts. While these methods exist, there remain quality assurance challenges regarding the detection of internal defects.
This Study focuses on analyzing the vibrational response of 3D printed metal beams with multiple internal defects modeled as voids, using analytical and Finite Element Methods (FEM). The study aims to locate and characterize these internal voids and understand their impact on the structural integrity of beams. A key aspect of this analysis is using the Relative Frequency Shift (RFS) method, which examines the natural frequency changes in beams with voids to identify and understand the impact of the voids on the composition, structure, and mechanical properties of the beam. ANSYS software confirms the results of this method, simulating real-world conditions. This paper offers a comprehensive approach to detecting internal voids, ensuring structural integrity, and enhancing quality assurance of 3D printed metal parts.
Numerical Investigation of Wear Characteristics of Rollers in Hot Metal Spinning Process
Authors: Demirtunç Mehmet , Özaslan Emre , Yetgin Ali , Acar Bülent 
Published: January 2025

Abstract
In the hot metal forming industry, the estimation of roller lifespan is crucial as it directly impacts costs. When rollers are commercialized in the industry, it is necessary to specify the roller lifespan. One of the factors directly influencing roller lifespan is wear. Rollers are prone to wear due to repeated mechanical loads over long periods of time under high temperature.
In dry metal spinning processes with high rotation and advancement velocities, the wear of the rollers needs to be calculated. Therefore, the proposed framework delves into the assessment of wear quantities, a pivotal metric for estimating roller lifetime. Wear exhibits different behaviors based on temperature. In processes where rollers are exposed to high temperatures exceeding 400°C, adhesive wear predominates, resulting in the adherence of roller particles. Conversely, the focus shifts to abrasive wear in processes where roller temperature ranges between 27°C and 400°C, as is in this study. In spinning processes where the temperature of the workpiece attains 900°C, the temperature of the hot tool steel rollers does not exceed 400 degrees. Accordingly, warm wear equations are utilized in the examination of roller wear within processes up to 900°C. In this situation, the wear calculation utilizes the Archard wear model. Time-dependent contact pressure and sliding velocity values for rollers with high rotation and advancement velocities are calculated using the finite element model. However, the wear constant and hardness of the roller vary with temperature. Therefore, the model takes into account the variation of wear constant and hardness based on temperature. A coupled temperature-displacement model is established to capture the heat transfer between the roller and the workpiece. Subsequently, relationships between wear constant – temperature and hardness – temperature are established, enabling the execution of wear calculations. The workpiece and roller are modeled using solid elements, and wear is calculated based on points on a cross-sectional surface of the roller. The wear on the cross-section is generalized to the entire cylindrical solid model, and the wear profile on the cylindrical roller surface during the hot dry metal spinning process is examined. In this study, a novel method developed for wear prediction of cylindrical rollers in hot dry metal spinning processes is proposed. The developed method can be generalized for all calculation of wear for dry metal spinning and forging processes regardless of temperature. The future work includes experimental validation of the wear performances and profile of the Roller for Hot Dry Metal Spinning Process.
Numerical Simulation of a Supersonic Flow Over a Flat Plate
Authors: Banos Lemus Diego , Law Deify 
Published: January 2025

Abstract
Studying supersonic flow simulations over a flat plate serves as a foundation in understanding the complexity of several aerodynamic problems. This paper investigates such problems using Fluent to gain insights of the properties and characteristics of the fluid behaves when a flat plate is set under such flow. These insights are then applicable to the development, study and analysis of other simple aerodynamic shapes that later, help with the development and the design of high-speed vehicles, such as rockets, missiles, airfoils, and aircraft. The two-dimensional laminar flow simulation employs the complete Navier-Stokes equations alongside the Second Order Upwind scheme to achieve a steady-state solution using the density-based solver. The air is modeled as a perfect gas with a constant Prandtl number, and the viscosity being evaluated by Sutherland’s Law at Low Reynold Numbers. The obtained results are compared against analytical solutions and literature values to assess deeper understanding of how shock waves interact with the boundary layer in supersonic flows, with a specific focus on analyzing the velocity, pressure, and temperature fields in the created domain and at the trailing edge of the selected geometry. The structured mesh is employed in the first case, developing later a more refined mesh as a second case to optimize the cell numbers stacked on the flow domain for a better analysis and capturing of shockwaves. This initial approach provides a good defined foundation for future investigations with turbulence models and the study of different geometries found on high-speed vehicles Future work will involve extending the simulation with the turbulent flow models at different Mach numbers, investigating different variations in the flow field with a longer flat plate when there is a transition between laminar and turbulent flow.
Magnetorheological Finishing of 3D Printed Free-Form Aerofoiled Surface
Authors: Khatri Shubham , Singh Surya Pratap , Singh Anant Kumar 
Published: January 2025

Abstract
Polylactic acid (PLA) is popular in 3D printing due to its affordability, biodegradability, and user-friendly properties. Industries such as automotive, aerospace, and medical are increasingly integrating PLA-printed parts. In the present study, a 3D-printed aerofoil is taken as a 3D workpiece. The surface finish of aerofoil plays a crucial role in aviation and fluid dynamics. In aviation, it enhances efficiency in generating lift and stability. In fluid dynamics, it minimizes drag and reduces turbulence. The use of magnetorheological finishing (MRF) enhances the surface quality of aerofoils. MRF has controlled finishing forces to obtain the desired surface finish, coupled with tool rotation and swirling motion, which remove roughness peaks. MRF employs MR polishing (MRP) fluid containing abrasive and electrolyte iron particles suspended in a base fluid. Finite element analysis (FEA) determines the magnetic flux intensity for MRF. The parameters, like current, working gap, and tool rotation speed, are set at 2A, 0.6 mm, and 300 rpm. Initial surface roughness (Ra) of the 3D-printed aerofoil is measured as 9.13 μm, reduced to 0.21 μm through 15 minutes of grinding. MRF of 25 minutes reduced Ra to 0.03 μm. Scanning electron microscopy (SEM) is used to analyze the surface characteristics of aerofoil before and after MRF. The reduced Ra of the aerofoil can enhance the aerodynamic performance by reducing drag and increasing lift. Also, it promotes laminar flow and reduces turbulence. The MRF process on aerofoil proves the six-axis MRF setup is capable of removing the stair-stepping effect from the 3D printed workpiece and provides fine finishing for its better performance.
Experimental Testing of Hydrodynamic Tapered Land Fixed Geometry Thrust Bearing Under Dynamic Load
Authors: Ali Muhammad , Lutfullaeva Anbara , Yasko Isaiah 
Published: January 2025

Abstract
Hydrodynamic thrust bearings in rotary machines are affected by varying environmental conditions, necessitating a clear understanding of operating parameters like oil film pressure, thickness, and temperature. Measuring oil film pressure, especially under dynamic conditions, is challenging but crucial for proper design. This study presents experimental investigation of tapered land hydrodynamic thrust bearings under dynamic loading, filling a gap in published research. A custom dynamic loading system was designed and installed into a previously established static loading tapered land hydrodynamic thrust bearing testing apparatus. Here, the new dynamic loading system is used to measure film pressures under dynamic loads (2–10 Hz, 150 lbs, 350 lbs peak loads, and 1500 RPM) to a thrust bearing with 0.002” taper depth. Results are compared to static load tests with similar peak loads and show significant pressure reductions (up to 59.4%) with increasing load frequency. These findings offer insights into hydrodynamic thrust bearing performance under dynamic loads, aiding in design considerations.
A New Morphology Evaluation Method for 3d Printed Surfaces Based on GLCM
Authors: Chen Hua , Chen Shijie , Yang Can 
Published: January 2025

Abstract
3D printing is the primary processing technology of additive manufacturing, widely utilized in industries such as healthcare, aerospace, and automotive. Due to technical limitations, its surface exhibits quality defects, including laminar texture, warpage deformation, bubble holes, and cracks. Its unique processing principles result in a surface appearance distinct from subtractive manufacturing. Evaluating 3D printed surfaces using traditional subtractive manufacturing methods neglects local features, has limitations in quantification, lacks comprehensiveness, exhibits strong subjectivity, and has low evaluation efficiency. In this paper, a new method for quantitative analysis and evaluation of 3D printed surfaces had been proposed based on Gray Level Co-occurrence Matrix (GLCM). The method provides a more comprehensive evaluation of the surface quality in terms of four dimensions: contrast, energy, correlation and entropy by acquiring image data from the surface of different 3D printed samples and applying the GLCM to accurately analyze the surface texture. Firstly, the effects of step size, gray level, and orientation on the GLCM were investigated, and the surface topography of 3D printed workpieces was measured by using the GLCM with appropriate parameters. Subsequently, four feature parameters, i.e., contrast, energy, correlation, and entropy, were used to comprehensively evaluate the surface of the workpiece. This method provides a new idea for the evaluation and quality control of 3D printed complex surfaces.
Energy Absorbing Analysis and Deformation Mode Comparison of Traditional and Additively Manufactured Crush Tubes
Authors: Jenson Sean , Switzer Ian , Ali Muhammad , Wisner Brian 
Published: January 2025

Abstract
Thin-walled axial crushing members (or “crush tubes”) are often utilized for energy absorption due to their high strength-to-weight ratios. They are created by filling a homogenous outer “tube” with a filler “core” material. The addition of the core has been shown to provide multiple benefits, including an increased structural stability during deformation or collapse and an increase to the energy absorbed by the structure. The total energy that can be absorbed by these structures is dependent on the deformation modes present during compression as well as the material properties used for the tube and core. Common core geometries include graded honeycomb structures or similar support members. Additive manufacturing (AM), however, has created an opportunity for complex energy absorbing structures to be used instead. Specifically, laser powder bed fusion (LPBF) can be used to manufacture complex geometries from aluminum powder with material properties comparable to an extruded state. The present study aimed to compare AM and traditional axial crushing member cores with a graded cellular structure through a numerical approach using ABAQUS/Explicit dynamic modeling environment. Material properties were assigned to a traditional tube (A36 steel) with a standard cellular core (6061 Al) and to a traditional tube with an AM cellular core (AM Al), both with frictional loss penalties and general contact property definitions. Analysis was performed until densification of the structure was observed and numerical results were recorded for the crushing force, deformation mode(s), plateau stress, and total energy absorbed for each tube variation and the results compared. The results of this study found that the AM core had comparable performance to the extruded version, with the AM core presenting a 3.1% increase in total energy absorption over the extruded core.
Modeling of Nanoscale Characteristics of Carbon Nanotube Nanocomposites Through Experimental and Statistical Methods
Authors: Norkus Tyler , Yekani Fard Masoud 
Published: January 2025

Abstract
The versatility of polymer matrix fiber-reinforced composites enables a wide range of applications in industry. Carbon nanotubes (CNTs) can be used to reinforce polymer nanocomposites (PNCs), but as with other laminated composites, delamination remains a concern and influences the integrity of the composite system. This paper examines the ratio between CNT bundle size and interphase thickness through atomic force microscopy (AFM) and statistical analysis of nanoscale data in an effort to introduce a new parameter for the fracture toughness of CNT PNCs. Specifically, the authors characterized buckypaper, a composite made up of CNT networks in epoxy. AFM was used to collect 500 data sets for low-weight percentage CNT PNC and almost 190 sets for high-weight CNT PNC. The data sets included the distribution of CNT bundle size and interphase thickness; several Weibull models were used to analyze the stochastic data distribution and simulate the properties of CNT PNCs. Two-, three-, and four-parameter Weibull models were used, with initial results showing that the four-parameter model was most effective.
Rapid Prototyping of Protective Structures for Micro-Unmanned Aerial Systems Through Additive Manufacturing
Authors: Emerick Ludvig , Mcghee Evan , Murphy Nolan , Harkin Darragh , Aliperti Chris , Hoyer Brodie 
Published: January 2025

Abstract
Micro Unmanned Aerial Systems (mUAS) continue to gain prominence on the modern battlefield, providing an expedient and portable platform for conducting Intelligence, Surveillance, and Reconnaissance (ISR) to small, isolated combat units. The objective of this study is to develop a rapidly-deployable, intuitive, and low-cost means of preventing damage to mUAS rotor blades, enabling increased training hours at decreased potential cost and thereby increasing overall operator proficiency on the system. To that end, we concurrently pursued two possible solutions: (1) use of additive manufacturing to design and produce a low-cost, easily replaceable airfoil that could be used during training exercises in lieu of the high performance airfoil and (2) the use of additive manufacturing to create a protective structure around the existing rotor that could be easily affixed to the mUAS for training operations while reliably sheltering the rotors from potentially damaging impacts. While the replacement rotor blade revealed shortcomings in current additive manufacturing processes for this application, the protective barrier accomplished the goal of increasing survivability of the mUAS performance during training while not significantly impairing its performance. Through this design study, we succeeded in creating an adaptable, open source, easily distributed “press print” solution that will allow units across the Army to print, on an as-needed basis, rotor protection structures, easily and effectively increasing user proficiency on a key enabling technology.
Modeling and Simulation of Wellhead Installation Digital Position Sensing Measurement
Authors: Wang Yaou , Lim Haw Keat , Lee Yong Wee , Zhang Haitao , Battentier Amandine 
Published: January 2025

Abstract
Correct installation of the wellhead is crucial to drilling operations for the oil and gas industry. Installation is conventionally examined manually and visually with high potential risk of errors. A digital position sensing solution for wellhead installation was recently developed through combining ultrasonic nondestructive testing and machine learning methods. Training the machine learning model required extensive data through a large number of laboratory tests. This work applies the finite element method to simulate the ultrasonic nondestructive laboratory testing process. Simulation prediction showed identical echo waves and sensor signals as test measurements. The simulation method developed in this work generated physical mode-based predictions, which would help understand the sensing solution system and potentially provide it with supplemental training data. This would further the reliability of the sensing solution system.
Parylene Capping Layer for Embedded Liquid Mass for MEMS Packaging
Authors: Adhikari Rahul , Jackson Nathan 
Published: January 2025

Abstract
Microelectromechanical Systems (MEMS) packaging is over 80% of the cost of a typical MEMS device because there are no standard packaging methods, and each device requires unique packaging. Recently several MEMS devices have illustrated the desire to have a liquid filled cavity within the MEMS device for applications such as biomedical sensors, tunable energy harvesters, or liquid cooling microelectronics. However, embedded liquids in silicon pose a challenge when it comes to packaging. This paper illustrates a novel concept of using a conformal parylene coating to cap or encapsulate the liquid. The concept is validated using various liquids such as various viscosity silicone oils as well as Galinstan a Ga-based liquid metal. The study investigates the packaging reliability through a series of systematic accelerated life-time testing, elevated temperature testing, accelerated soak testing, and mechanical testing (shock and resonant frequency testing). Mass changes were monitored and compared to control (no capping), glass epoxy bonded packaging, and silicone spray coating encapsulation. The results demonstrate the superior mean-time-to-failure of the parylene capping method compared to the other methods. The results confirm that parylene can be used to package embedded liquids in silicon or 3D printed structures.