bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation and Experimental Validation of a Microfluidic Device
Authors: Carvalho Violeta , Gonçalves Inês M. , Rodrigues Nelson , Sousa Paulo , Pinto Vânia , Minas Graça , Rodrigues Raquel O. , Teixeira Senhorinha , Lima Rui A. 
Published: February 2024

Abstract
The combination of microfluidic devices with cell culture methods has risen over the years due to their ability to replicate several diseases and test different therapeutic techniques. Unlike in vivo models, in vitro systems avoid ethical issues and allow researchers to control several physiological variables and mimic the physiological microenvironment at reduced costs. Along with the experiments, computational tools have also played an important role in assessing fluid flow and related phenomena. Nonetheless, to assure that the numerical outcomes provide a good approximation of reality, its validation is needed. Despite this step being usually disregarded, it is of great importance to accomplish it. Herein, a microfluidic device was developed by combining additive manufacturing with a silicone polymer for flow visualization experiments, and its numerical model was established by using Ansys Fluent software. The results were compared both qualitatively and quantitatively. A good agreement was obtained, which indicates the potential use of the numerical model in further studies.
Design Optimization of Hexacopter Frame Using Generative Design and Additive Manufacturing
Authors: Azhagan M. Thirumal , Shanmugam Ragavanantham , Khan Saquib , Lata Surabhi 
Published: February 2024

Abstract
This research paper presents an investigation into the use of generative design for the optimization of hexacopter chassis. Hexacopters, which are six-rotor aircraft, have a wide range of applications in areas such as aerial photography, search and rescue, and package delivery. The use of generative design in this study aims to improve the performance of the hexacopter chassis while reducing material usage and cost. The optimization process involved comparing various properties such as weight, factor of safety, von Mises stress, and material used. A static simulation was also conducted to evaluate the performance of the optimized chassis. The results of the study demonstrate that generative design can effectively optimize the hexacopter chassis for improved weight-to-strength ratio, an increased factor of safety, and reduced von Mises stress. Additionally, the study shows that the use of generative design can lead to a significant reduction in material usage, resulting in cost savings. The benefits of using generative design in this study include the ability to explore a large number of design options, optimize for multiple objectives simultaneously, and generate designs that are not feasible to create manually. Overall, this research provides valuable insights into the use of generative design for the optimization of hexacopter chassis and highlights the potential of this design approach for other aerospace and mechanical engineering applications.
Control of Corkscrew Swimming Locomotion of Soft-Millirobots in a Different Frequency
Authors: Scurry Jordan , Trinh Jessica , Bulang Christophe , Park Jungkyu , Kim Dal Hyung 
Published: February 2024

Abstract
Soft millirobots have been researched and studied extensively in recent years. In this paper, we investigate the locomotion of a small soft millirobot using a rotating magnetic field on the movement at various frequencies. To fabricate the soft millirobots, a combination of clear polymer and ferromagnetic particles is mixed together, and the head of the robot is magnetized using a permanent magnet. The fabricated soft millirobots are then placed in a chamber partially filled with water, where they are suspended by the water tension and float on the water’s surface. To validate the locomotion of the millirobots, the experimental setup involves placing the chamber with the millirobot into an enclosure surrounded by Helmholtz coils, which generate a rotating magnetic field. The soft millirobots are then subjected to a range of different frequencies, and their movements are observed and recorded. The findings indicate that the soft millirobots exhibit a variety of different types of locomotion in response to the rotating magnetic field. Also, we have demonstrated the feedback control experiment to validate its controllability.
Numerical Study of the Friction Coefficient of an Incompressible Laminar Flow With Solid Particles Over a Flat Plate
Authors: González Eliezer J. , Navarrete Luis E. , Ayala Orlando M. , Ayala Orlando F. , Ayala Manuel 
Published: February 2024

Abstract
This article presents a two-dimensional numerical study of the coefficient of friction of an incompressible laminar flow with particles over a flat plate. Various cases are presented varying parameters such as volumetric fraction (αp), relative particle size (Rsp) and Stokes number (Stk). The friction coefficients of particle-laden flows are compared to the friction coefficient of a particle-free flow. The results show that, during the initial development of the boundary layer, the presence of particles generates a higher friction coefficient. As the boundary layer further develops, the increment of the friction coefficient reduces. We found a linear relationship of the friction coefficient increment with respect to the volumetric fraction and the relative particle size. The peak of the friction coefficient increment occurs at the critical local Stokes number (Stkx) of one. For cases with low particle concentration, the effects of the particle presence can be disregarded and considered the flow as particle-free flow.
Toward Better Formability of Polymeric Materials in Single Point Incremental Forming: Effect of Process Parameters
Authors: Upcraft Clayton , Diefenderfer Rachel , Vanderwiel Chad , Ragai Ihab 
Published: February 2024

Abstract
Single-Point Incremental Forming (SPIF) is a process for low quantity production or prototyping of sheet products. It involves a sheet secured in a fixture, formed by the downward forces of a hemispherical endmill tool in a CNC mill. Multiple passes of the endmill tool deform the material until the desired geometry is attained. This study examines several combinations of SPIF process parameters, namely initial wall angle, feed rate, and step-down size, and their effect on the formability of the formability. Three materials were examined, polycarbonate (PC), polypropylene (PP) and polyvinylchloride (PVC). The following are the ranges in which the forming parameters were varied: feed rate from 1000 to 2000 rpm, wall angle from 10° to 30°, and step-down from 0.1 to 1.0 mm. The parameters that are held constant are the sheet material, tool material and diameter, and spindle speed. Sheets are formed by a 12.5 mm diameter copper 110 tool that is fixed in the spindle with no applied rotational speed, i.e., the spindle can rotate freely. It was found that the increase in wall angle results in local decrease of the thickness along the sides of the formed shape. Also, the results showed that feed rate has no significant effect on formability; however, an anomaly was observed that suggests there could be a threshold value after which thinning would be more pronounced. In all cases, the results showed heavy dependance on materials thermoplastic properties, particularly each material’s glass transition temperature.
Design and Development of a Low-Cost Prosthetic Leg for Below-Knee Amputations
Authors: Karibeeran Shanmuga Sundaram , Murugesan Pradeep Kumar , Jayakumar Jebin 
Published: February 2024

Abstract
Prosthetics are made with solid, biocompatible materials. Though the materials have a very good strength-to-weight ratio, they are not aesthetic or customized. Most of the time, it is made standard and is not lightweight for the user. Presently Metal 3D printing develops lightweight structures with the highest strength-to-weight ratio. In countries like India, the people have limited access to a good prostheses, as the prostheses is not affordable. The prosthetic limbs, to a certain degree, help amputees get back to their basic functional movement systems and help amputees develop better mobility and operate freely without depending on others. The design and fabrication of an improved and affordable prosthetic leg for people with below-knee amputation which will mimic the function of the natural leg using additive manufacturing technology. The additive manufacturing allows design freedom and customisation advantage. Autodesk Fusion 360 and Solid Works software was used for solid modelling and simulation and topology optimization was done using Autodesk Fusion 360. After measurement of the leg parameters, the measured data are fed into editable 3D software. The best design is chosen from the available designs based on ESAR foot (Energy storage and return foot). The present work based on topologically optimized design and ESAR foot was able to withstand the given loads and can be easily moved and thus chosen for further manufacturing and testing. This pave the way to develop a customer-oriented design and use 3D printing to make prosthetic legs that would look more personal and aesthetic.
A Numerical Study on Performance Enhancement of Locally Produced Axial-Flow Fans for Grain Drying
Authors: Estaquio Ren Paulo , Danao Louis Angelo , Lustro Julius Rhoan 
Published: February 2024

Abstract
Utilization of a flatbed dryer (FBD) as a postharvest technology particularly in grain drying is continuously thriving in the Philippines. Throughout the years, its drying chamber component has been upgraded continually to improve overall dryer efficiency. However, its mechanical component, the fan, which drives the heated air into the chamber was found to perform poorly compared to international commercial fans. For instance, locally produced tube-axial fans perform at most 30% in efficiency compared to commercial ones that run at least 67%. The design of one of the tested locally produced fans is investigated through numerical methods, specifically using computational fluid dynamics (CFD), for potential development to achieve higher efficiency. In this way, parametric investigations can be performed at a much less cost compared to the cost of conducting physical testing. A general CFD model is developed to replicate the local standard procedure of testing agricultural fans and blowers. Furthermore, the present study uses the model to examine the effects of varying three (3) blade parameters on the aerodynamic performance of a reference fan. These parameters are the blade count, the tip clearance, and the pitch angle. FBD requires a specific static pressure and volume flow rate (PS-Q) depending on its drying chamber’s capacity and type. A methodology is introduced to capture the optimal rotational speed that applies for both individual PS-Q and a range of static pressures.
The investigation yields the following results: the current design (CD) with 12 blades appears to be optimal near the static pressure of 250 Pa. The static efficiency of the fan is proportional to the no. of blades until CD where the performance metric started to plateau. Decreasing the tip clearance drastically enhances the performance of the axial fan, with tip clearance ratio, TR, of 2.13% providing the highest improvement. The increase reached as high as 37% change to the CD with a TR of 4.80%. An axial fan with a blade pitch angle of 33° shows to be the superior option for an FBD with 250 Pa static pressure requirement. For FBD with higher PS-Q requirements such as 375 Pa and 500 Pa, the CD with 27° blade pitch angle is appropriate to use. The current study shows a numerical method like CFD can be applied to perform a cost- and time-effective design optimization to turbomachines such as fans attached to the FBD. More importantly, the developed CFD model can be extended to be used to investigate other parameters of the axial fan or to develop the design of centrifugal fans utilized in Philippine agricultural technologies.
Recent Development and Limitations of Laser Patterned Riblet-Structures
Authors: Hartung Konrad M. , Löschner Udo , Mauersberger Stefan , Oehlert Karsten 
Published: February 2024

Abstract
The extensive research over the last decades on riblet structures has proven their potential for vicious drag reduction in turbulent boundary layers. For an efficient application for technical use, however, riblet foils or riblets manufactured by grinding lack adaptability. In contrary laser processing technologies nowadays enable the production of riblet structures, whose dimensions can be adapted to the local flow conditions. As experiential laser structures differ process-related from ideal design specifications, however, a reliable prediction tool is necessary. Within this study, riblet structures were manufactured using a novel high-rate laser structuring technology. The viscous drag reduction is model based predicted solving the Navier-Stokes-Equations for a Coeutte flow over characteristic surface structures. Comparing own samples with samples manufactured by the national leading institutions in the fields, the achievable drag reduction shows an ongoing improvement with a currently achieved maximum wall shear stress reduction in the range of Δτ/τ0 ≈ –5,6%. This corresponds to about 70% of the viscous drag reduction achieved by geometric ideal structures. The authors will point out that further improvements are hardly feasible as manufacturable riblet dimensions, especially the riblet tip width, are limited by laser-physical and process-related restrictions.
A Statistical Machine Learning Approach to Predict Residential HVAC Usage With Lagged Environmental Predictors
Authors: Baath Jashanjeet , Little Madelyn , Bhattacharya Anirban , Bandyopadhyay Arkasama 
Published: February 2024

Abstract
Wasteful energy uses, such as heating and cooling of unoccupied homes and rooms, inefficient appliances, and thermostat oversetting, contribute to at least 43% of total energy use in the residential sector. Accurate knowledge of domestic appliance-level electricity usage patterns can help energy modelers at electric utilities make informed decisions about residential load control and dynamic rate design. This study enhances an existing statistical machine learning approach to predict domestic appliance usage trends from overall energy consumption data obtained from Pecan Street Inc, by adding lagged environmental predictors. Five time-series on time-series regression models are explored, each with different combinations of lagged/current ambient temperature and relative humidity. The relative performances of the models are evaluated using the Akaike Information Criterion (AIC) value — a widely used model selection metric that determines the quality of a model by considering the data fit as well as model simplicity. Fifteen-minute interval data from two single-family detached homes in Austin, TX are used to demonstrate the methodology developed. Results indicate that while including lagged temperature and humidity as predictors enhances the quality of the energy consumption projections, there is not any significant difference among the models with various combinations of lagged/current environmental predictors.
Investigation of the Structural Behavior of Countersunk Bolts Under Multi-Directional Loading
Authors: Aksoy Tuğrul , Altıntaş Başar , Dilber Ahker Güneş 
Published: February 2024

Abstract
Tensile tests were performed by using the Tension/Shear Combined Loading (TSCL) test set-up at five different loading angles to understand the effects of combined loading on the countersunk bolts and compare the shear/tension interaction results with the failure envelopes from different references. Then the double shear tests were carried out so as to measure the bending effect on the failure of bolts and loading capacities were found as similar with the ones obtained from pure shear (90°) results of TSCL tests indicating that the bending moment effect on the loading capacities is unclear. Finally, a single countersunk bolt was tested on a special single lap shear joint by monitoring the bending load with two strain gauges attached on the bolt shank and a numerical simulation were performed on a finite element analysis model to verify the experiment. As a result, it is observed that the bending moment increases with the increasing load up to a certain point, and then gradually decreases as the load increases. Finite element analysis results were found as compatible with the results of this experiment. Both of the experiment and finite element analysis results demonstrated that the bolt bending affects the deformation process but does not have a significant effect on the load capacity of the bolt.
Computational Analysis for Effects on Hemodynamic Parameters Based on the Location of Cerebral Aneurysms
Authors: Reddy Garigapuram Prithvinath , Katore Srushti , Flamini Vittoria , Sahin Iskender 
Published: February 2024

Abstract
Cerebral aneurysms can affect about 1.5 to 5 percent of the general population. A ruptured aneurysm in the brain can result in severe consequences. The majority of brain aneurysms are seen in the anterior circulation near the bifurcation of an artery. Computational Fluid Dynamics is commonly used for conducting various analyses on the segmented images obtained from Magnetic Resonance Imaging, Magnetic Resonance Angiography, or Computed Tomography scans. This paper aims to analyze the different effects on hemodynamic parameters based on the locations of aneurysms. The most common locations for aneurysms in cerebral arteries are the Anterior Communicating artery, Middle Cerebral artery, and Internal carotid artery. In this study, four models were chosen for each corresponding location to determine and compare the hemodynamic parameters obtained from the analysis. To maintain homogeneity among the models, all of them had the same rupture status. The models were segmented and then processed in the ANSYS™ SpaceClaim software to produce idealized geometry for further analysis. They were further processed in ANSYS™ Fluent Mesh and Solver to create an idealized pulsatile blood flow. The hemodynamic parameters studied for this paper are Flow Velocity, Pressure Distribution, and Wall Shear Stress. The parameters are then compared to analyze how each location is affected.
Acceleration of Creep-Fatigue Damage of Ni-Base Alloy by Viscoelasticity at Elevated Temperature
Authors: Miura Hideo , Yasumura Ayane , Yamawaki Takuma , Kudo Takuto , Matsuda Hayato , Xu Le 
Published: February 2024

Abstract
The basic mechanism of the wide fluctuation of the creep-fatigue damage at elevated temperatures was clarified from the viewpoint of the loading strain rate. In this study, intermittent creep-fatigue tests were applied to a Ni-based superalloy, Alloy 617, and the degradation process of its crystallinity was monitored using an EBSD method. Creep-fatigue tests were performed intermittently at 800°C in inert Ar gas using small dumbbell-shaped specimens, and the degradation process of micro texture and local crystallinity of the alloy under the creep-fatigue loading was continuously observed in the same area in each specimen. IQ and KAM values and Schmid factor were applied to the crystallinity analysis. The main reason for the acceleration was found to be the accumulation of the residual strain during the unloading cycle and this accumulation occurred due to the activation of viscoelasticity of the alloy at elevated temperature. In particular, when the unloading time was shorter than the relaxation time of the material at that temperature, a next loading cycle started before the full relaxation of strain under stress control conditions. As a result, under this condition, therefore, the magnitude of the applied load and thus, creep-fatigue damage increased continuously cycle by cycle as a strong function of the period of the creep-fatigue load.
Improvement of Sensitivity and Selectivity of Graphene-Based Gas Sensor by Strain
Authors: Qiao Xiangyu , Yin Meng , Suzuki Ken , Miura Hideo 
Published: February 2024

Abstract
Graphene has been considered to be the most promising next-generation gas sensing material because of its large surface-to-volume ratio, excellent gas adsorption properties, and high carrier mobility. Application of strain to graphene was found to modulate its Fermi level, and thus, it is expected that the gas adsorption behavior of graphene is changed by strain, leading to enhanced sensitivities and selectivity of graphene-based gas sensors.
In this study, the effect of strain on the gas adsorption behavior of graphene was experimentally investigated. Monolayer graphene with high quality was synthesized by low-pressure chemical vapor deposition, and a graphene-based flexible gas sensor was fabricated on a polyimide substrate. The performance of the sensor was evaluated in situ in a homemade gas testing system. The good stability of the sensor under compressive strain was confirmed. A good sensitivity to NO2 and NH3 was observed in the fabricated sensor. Under compressive strain, the sensitivity of the sensor to 1-ppm NO2 was found to be increased by about 0.07%/%ε, and to 10-ppm NH3 was increased by about 0.11%/%ε, indicating the possibility of improving the performance of graphene-based gas sensors by strain.
Machine Learning-Based Fatigue Life Evaluation of the Pump Spindle Assembly With Parametrized Geometry
Authors: Wang Lizhe , Zhang Zhichao , Chen Min , Xie Junyi , Liu Fuyuan , Yuan Hang , Xiang Zhouyi , Yu Lingyun 
Published: February 2024

Abstract
Artificial intelligence-based fatigue analysis methods have gained considerable attention in recent years, but little research has been conducted on the fatigue behaviors of assembled structures, which involve numerous factors that impact structural fatigue life and complicated assembling associations in parameter selection. This paper presents a hybrid machine learning (ML) model-based evaluation platform for data-driven fatigue life analyses of a parameterized industrial pump spindle that considers the impacts of variable loads and characteristic design parameters. Firstly, the numerical fatigue evaluation is validated by comparing experimental and simulation results of spindle samples with a specific dimension. Secondly, datasets for training and testing are constructed to assess high cycle and low cycle fatigue lives of parameterized pump spindle assemblies under two real working conditions of cyclic start-stop and continuous running. The proposed hybrid ML method exhibits excellent overall performance for both running conditions, validating its accuracy and reliability. Additionally, the superiority of the hybrid method for fatigue evaluation of the assembly is confirmed through performance comparisons between single forward models. Finally, sensitivity-based parametric analysis is performed to interpret the model, revealing that pre-tightening load and diameter of the shaft seal have the most significant impacts on the fatigue properties under both cyclic working conditions. This work provides an efficient tool for quantifying the fatigue lives of parametrized spindles and contributes to the safety assessment in structural design and optimization.