bluuebunny/crossref_metadata_2025_split huggingface dataset:
Students Perceptions of a Hybrid and Flexible Teaching Model for Post-COVID19 Normality
Authors: Rodriguez-Paz Miguel X. , Gonzalez-Mendivil Jorge A. , Zamora-Hernandez Israel , Zarate-Garcia J. Asuncion 
Published: January 2022

Abstract
In this work we present a hybrid model that can be applied in theoretical Engineering courses, combining flipped learning, collaborative activities and online tutorials. A total of 200 students that participated in online courses with the authors responded a survey. The results include what in the students’ perception was the best implementations of online courses, what makes a course attractive and motivating for students and also, what should be avoided in future implementations of courses that need to be taught in an online format. Some of the results show that students did not enjoy courses where lecturing was the main element during most of the session. The recommendations included in this work deal not only with the type of contents an online course should have but also with certain details about some recommended courses professors could take in advance, that is, before they start teaching online and some other recommendations that can make a model like this one a successful model for online teaching in a post-covid world.
Towards a Model for the Melt and Flow of Aluminum Alloys in Fires
Authors: Brown Alexander L. , Tencer John , Kucala Alec , Pierce Flint , Noble David R. 
Published: January 2022

Abstract
Melting and flowing of aluminum alloys is a challenging problem for computational codes. Unlike most common substances, the surface of an aluminum melt exhibits rapid oxidation and elemental migration, and like a bag filled with water can remain 2-dimensionally unruptured while the metal inside is flowing. Much of the historical work in this area focuses on friction welding and neglects the surface behavior due to the high stress of the application. We are concerned with low-stress melting applications, in which the bag behavior is more relevant. Adapting models and measurements from the literature, we have developed a formulation for the viscous behavior of the melt based on an abstraction of historical measurement, and a construct for the bag behavior. These models are implemented and demonstrated in a 3D level-set multi-phase solver package, SIERRA/Aria. A series of increasingly complex simulation scenarios are illustrated that help verify implementation of the models in conjunction with other required model components like convection, radiation, gravity, and surface interactions.
Numerical Modeling of Air Cell Cushion and Estimation of Shear Force Distribution at Sitting Interface
Authors: Erel Veysel , Nuthi Pavan , Gu Yixin , Purandare Himanshu , Haldipurkar Nischita , Wijesundara Muthu B. J. 
Published: January 2022

Abstract
Shear forces at sitting interfaces are a major contributing factor in pressure injury formation. However, measuring shear forces throughout the sitting interface is not possible due to a lack of shear sensors for this application. This paper presents a finite element simulation model for an automated air cell smart seat cushion that can predict shear forces at the interface. The model was developed and validated by comparing static analyses to experimental data, with respect to interface pressure, internal air cell pressure, and interaction forces. The real-time experimental data in this study was generated from three different sources: 1) A commercial seating pressure mat yields an interface pressure map, 2) The smart seat cushion yields the internal pressure of air cells, and 3) The rigid cushion loading indenter yields the immersion into the cushion and the force applied on the cushion. The validated simulation model was used to evaluate shear force data at the sitting interface corresponding to different loading scenarios.
Effects of Combined Electromagnetic and Bottom-Plug Stirring in a Steel Refining Ladle
Authors: Godinez Joel , Walla Nicholas J. , Guo Xipeng , Zhou Chenn Q. 
Published: January 2022

Abstract
After being tapped from a basic oxygen furnace or electric arc furnace, the liquid steel must be refined at a ladle treatment station as part of alloying and quality improvement. In the ladle, the steel can be stirred using electromagnetic techniques, argon injection, or a combination of both methods. This work discusses the observed differences in stirring characteristics between these different approaches. Simulations of gas-stirring using a single plug, stirring using upwards electromagnetic stirring (EMS), downwards EMS, and the combination of electromagnetic stirring and single bottom plug with various plug positions in relation to the active EMS unit. The approach found in this work uses the CFD solver ANSYS Fluent to the simulate the isothermal multiphase flow field using a combined Eulerian and Lagrangian (E-L) approaches. The E-L approach with DPM uses a time-step (ts) of 1e−3s while the mixing study uses a ts of 0.1s.
To improve simulation stability and computational speed, the Lorentz forces of the magnetic field data are imported directly into the simulation via User Defined Function and applied as a momentum source term onto the liquid steel. The flow field is monitored for quasi-steady state, upon which the momentum calculation is disabled and the secondary mixing study begins. The mixing study uses a tracer species to determine how long is required until homogeneity is reached. It was found that under standard stirring conditions, EMS has a faster mixing time than EM-Gas and gas-only, though both EMS and EM-gas see greater wall shear stresses.
Attempting To Establish Design Margins for Glassy Polymers In Critical Structural Service
Authors: Kemper Bart , Williams Kaylie Kling 
Published: January 2022

Abstract
The existing code procedures for glassy polymers are in ASME Safety Standard for Pressure Vessels for Human Occupancy (PVHO-1). The current service spans hostile conditions in the North Sea to controlled medical environments. These procedures are based on an empirical method and do not use material properties. The system is locked into specific shapes and cannot be adjusted to account for yield strength, ultimate strength, and other material considerations. An ASME task group is developing a Design By Analysis (DBA) methodology in order to allow for optimization in current service and innovation in other service. This paper presents the attempt to develop design margins as part of an overall risk assessment process that considers material properties, service conditions, and other factors not currently incorporated in the existing design method. Historical work used to develop the current system are analyzed using modern methods to attempt to quantifiably determine the existing design margins. The challenge is the empirical method implicitly relies on polymer manufacturers to greatly exceed the code. This, coupled with different modes of failure, results in no direct manner to compare PVHOs to conventional ASME pressure vessels design margins.
Lateral-Directional Stability and Manual Control of Understeering and Oversteering Vehicles in Off-Road Conditions Based on a 2-DOF Cornering Compliance Vehicle Dynamics Model
Authors: Van Auken R. M. , Kebschull S. A. 
Published: January 2022

Abstract
The lateral-directional stability of four-wheeled ground vehicles with understeer and oversteer characteristics in off-road conditions were investigated using a locally linearized vehicle dynamics model with two degrees-of-freedom. Analytical results confirm the widely accepted understanding that the open-loop response for an understeering vehicle with the steered wheels fixed parallel to the vehicle centerline is stable for all vehicle speeds, while an oversteering vehicle is unstable above a certain ‘critical speed’ for the same fixed steering condition. However, results for both understeering and oversteering vehicles using a path-centered steer angle input, defined relative to the path tangent, were found to be stable for all forward speed conditions. These results also indicated that the path-centered steering can be used for lateral-directional control with suitable gain. Therefore these results indicate that a manual control strategy based on path-centered steer angle inputs can be used to stably control a vehicle for all forward speeds, in both understeering and oversteering conditions, provided the tire cornering force continues to increase with slip angle, which is generally the case for vehicle off-road or snow conditions. These results are also consistent with ground vehicle operator acceptance and preference of vehicles with oversteering characteristics in off-road conditions.
Design of Model-Based Linear and Nonlinear Controllers to Stabilize a Simple Experimental Setup for Controls Education
Authors: Ilhan Zeki Okan 
Published: January 2022

Abstract
This work aims to demonstrate the use of a simple experimental setup to study and benchmark different stabilizing control algorithms for introductory to elementary controls education. The experimental setup consists of a ping-pong ball rolling on a pivoted beam. The control task is to stabilize the ball at the center of the beam by systematically changing the angle of rotation of the beam through the servomotor. A control-oriented dynamic model is first obtained based on the standard Lagrangian approach. Two different model-based control design techniques are then outlined using the developed first-principles model. First, a state-space approach based on the linear-quadratic-regulator optimal control design is proposed using the linearized (approximate) model. An integrator is added to the standard LQR design to improve upon the closed-loop tracking performance. Next, a nonlinear robust design technique is outlined using the full (nonlinear) model in Sliding-Mode Control (SMC) strategy. Challenges for each control technique are discussed based on the initial results, and possible improvement areas are addressed.
Mars Drone Configurations And Approaches to Rotor Design: A Review
Authors: Saez Aleandro , Manzo Maurizio , Ciarcià Marco 
Published: January 2022

Abstract
This paper briefly reviews the literature inherent of the design of airfoil and rotorcrafts for atmospheric flight on Mars. The interest toward the red planet exploration has considerably increased as result of the successful deployment of the Perseverance Rover and the continuous tests developed by SpaceX’s launch vehicle, Starship. While the Mars 2020 Mission is currently in progress, the first controlled flight on another planet have been proven in April 2021 with the Vertical Take-off and Landing of the Ingenuity rotorcraft in Mars. In addition, the rotorcraft Dragonfly is expected to achieve the same endeavor in Titan, the largest moon of Saturn, by 2036. Continuous efforts have been oriented to the development of new technologies and aircraft configurations to improve the current designs and performance. In this paper we summarize the different Mars drone design and configuration approaches carried out by several research groups in the last two decades. We also briefly layout the main challenges related to the lift generation problem for a Mas rotorcraft.
Fabrication of Bioinspired Micro/Nano Textured Rough Surfaces Through the Scalable Roll Coating Process
Authors: Chockalingam Sekkappan , Ryu Jong Eun , Islam Md Didarul , Harbinson Myers 
Published: January 2022

Abstract
Bioinspired Micro/Nano textured rough topography of a surface has many applications in super-hydrophobicity, self-cleaning surface, anti-icing coatings, anti-biofouling, and drag reduction surfaces. The role of hierarchical and complex surface topography in nature is to amplify the hydrophobicity and maximize the fouling resistance. Thus, a similar micro- and nano-scale 3-D topographic surfaces inspired from the nature were fabricated using a simple and scalable two roll coating process. This process was based on the ribbing instabilities associated with the shearing of non-Newtonian fluids between two rollers. The polymer composite retains the deformed shape due to the recovery of high-viscosity after removing the shear stress. The relationship between the process conditions and the textured structure were studied with the shear rate, capillary number and the surface roughness parameters (e.g., Wenzel factor and density of peaks). The results showed that the samples’ Wenzel roughness factor increased with the increase in shear rate up to a particular value and then decreased. Similarly, the density of peaks in the sample increased with an increase in capillary number up to a particular value and then decreased. These bioinspired surfaces with hierarchical textured patterns produced using two roll coating process show a tremendous potentiality to be used in super-hydrophobic, anti-biofouling, and drag reduction applications.
Design and Test of Thermal Insulation Performance of Rail Vehicles
Authors: Cao Yanhua , Wang Jianran , Wang Lei , Jia Na 
Published: January 2022

Abstract
This paper discusses how to improve thermal insulation performance through one or several effective methods when designing rail vehicles. These methods are all validated by simulation analysis and testing. The EMU (Electric Multiple Unit) train is selected as a basic model for thermal analysis. The vehicle is divided into several modules based on thermal insulation characteristics and different thermal insulation materials and applications are compared and analyzed. A design solution which could improve the overall thermal insulation performance of the vehicle is proposed. The vehicle structure is divided into modules on different levels, and the thermal insulation performance of each module is analyzed preliminarily. Based on the proportion of each module in the vehicle, its influence on the overall thermal insulation performance is evaluated. Typical modules include carbody underframe, side wall and roof. Based on the preliminary thermal analysis results of modules above, the typical models of each component are established for study, calculation, and testing. The thermal insulation coefficients of different areas are compared to determine which one has the most potential of thermal insulation improvement. Technical cost, material cost and manufacturability are comprehensively analyzed to figure out the most reasonable insulation solutions for each module. Then, the proportion of each module in the vehicle and overall costs of thermal insulation proposal are analyzed to identify the correlation between the structure of each module and improvement of vehicle level thermal insulation performance. The solution to effectively improve the thermal insulation is proposed from a decision matrix, which consists of importance of proportion, difficulty of realization and comprehensive cost. At last, the simulation analysis and test data of the overall vehicle heat insulation performance are compared to validate the consistency between theoretical analysis and practice, which could further prove that the design solution proposed in this paper is feasible and effective.
Computation of Three-Dimensional Mixed Convection in a Horizontal Rectangular Duct
Authors: Oluwade Abimbola , Glakpe Emmanuel 
Published: January 2022

Abstract
Numerical investigation of mixed convection heat transfer in a three-dimensional, horizontal, rectangular duct has been carried out using COMSOL Multiphysics® simulation software. The bottom wall of the duct is subjected to a uniform heat flux condition, while the top and sidewalls are adiabatic. Uniform flow of water at 23°C (Pr = 6.5) is assumed to enter the duct of aspect ratio in the range of 1 ≤ A ≤ 10. Numerical computations are carried out for Re = 500 and modified Grashof number (Gr*) in the range of 2.5 × 105 ≤ Gr* ≤ 6.5 × 106. Results of the flow structure, local averaged friction factor (f), and local averaged Nusselt number (Nu) at the bottom of the duct for Re = 500, A = 2, and Gr* = 2.5 × 106 are compared with those from Incropera et al. [11]. Additionally, Nu values are also obtained for increased values of A and Gr* and compared with results from Incropera et al. [11]. Alongside incompressible flow with Boussinesq approximation, results are obtained for the weakly compressible form of the body force terms available in COMSOL Multiphysics®. Results show good agreement with published results in the literature, and the two results from the two approaches to approximating the body force terms are largely similar except at high Gr*. Additionally, a maximum heat transfer enhancement by buoyancy of ≈ 310% was found.
Droplet Dynamics in PEM Fuel Cell Flow Channels
Authors: Mortazavi Mehdi , Chauhan Vedang , Pedley Taylor , Whinery Brian M. 
Published: January 2022

Abstract
During the operation of proton exchange membrane (PEM) fuel cells, water is produced in the cathode side. The produced water passes through the porous structure of the electrode and emerges from the surface of the gas diffusion layer (GDL) within the flow channel. The emerged droplet is constantly fed through liquid columns which are formed underneath the droplet within the GDL. This study focuses on dynamics of growing droplets on the surface of the GDL which are exposed to shear gas flow. High-speed imaging was implemented to visualize droplet dynamics from emergence to detachment as the pressure drop across the droplet was measured simultaneously. Images were processed with MATLAB code which was developed in-house to obtain droplet lateral area and the location of the droplet centroid. Results clearly demonstrated that droplets underwent an oscillatory mode for both superficial gas velocities tested in this study. While the oscillatory motion was observed both in horizontal (i.e. stream-wise direction) and vertical directions, the amplitude of the oscillation was greater in the horizontal direction. In addition, the oscillation amplitude was observed to increase with droplet size and reached the maximum value upon droplet detachment. For a superficial gas velocity of 10.76 m/s, the oscillation amplitude upon detachment was as high as around 0.16 mm in x direction while the corresponding oscillation in y direction was around 0.06 mm. Study of contact angles revealed that while the advancing and receding contact angles for the superficial gas velocity of 4.17 m/s are higher than angles for the superficial gas velocity of 10.76 m/s, the contact angle hysteresis for both velocities were almost identical upon detachment.
Modeling and Simulation of Achilles Tendon in OpenSim for Verification
Authors: Salman Muhammad , Tanveer M. Hassan 
Published: January 2022

Abstract
The Achilles tendon is a very important tendon that is vital to an individual’s movement. Once these tendons are torn, they become very difficult to heal. In order to avoid this situation, it is crucial to understand the limitations of the Achilles tendon on the average person. To study the properties of an Achilles tendon, research can be done in many ways, such as data collection of in-vivo specimens. Although this can be done, using an online simulation can result in quicker and more accurate data. One program that can be used to create a simulation of an Achilles tendon is OpenSim. In this study 5 different subjects, both male and female with ages 22+/−5 years are studied. The subject will stand on one foot which is the maximum amount of weight on one leg and that Achilles Tendon. The forces will be calculated on that foot using sensors such as laser displacement sensors. The weight of the subject will cause the ground reaction and the magnitude of the tensile force which will be exerted by the gastrocnemius and soleus muscles on the calcaneus through the Achilles tendon will be calculated. The magnitude of the reaction force of the subject will be exerted at the ankle joint and it is applied by the tibia on the talus dome. The Achilles tendon is attached to the calcaneus bone and for this position of the foot, it is estimated that the line of action of the tensile force in the Achilles tendon makes an angle q (theta) with the horizontal, and the line of action of the ankle joint reaction force makes an angle b (beta) with the horizontal. We will use the force vectors to draw the concurrent diagram in order to find the unknown forces of the Achilles tendon and the tibia reactive force on the joint. By studying the properties of the Achilles tendon, while it is at 2 different dorsiflexed angles. These angles will vary from 0 degrees to 90 degrees. These concurrent force vector diagrams method will be applied to both configurations to find the unknown forces of the Achilles tendon and the tibia reaction on the dome of the talus. OpenSim is mainly used for biomechanical modeling and analysis of those models. The purpose of this research paper is to provide a comparison of data collected from real individuals and the simulation data from an OpenSim model.
Fundamental Scan Matching Approach to LIDAR Based Localization
Authors: Larson Joel , Mo Changki , Hudson Scott , Carter Emily 
Published: January 2022

Abstract
We are addressing a major problem in autonomous robotics, which is simultaneous localization and mapping (SLAM). Currently there are many methods available which to varying degrees solve the localization problem of SLAM. The majority use probabilistic concepts. However, these solutions often bring with them a high level of algorithmic complexity. This can raise the cost of implementation and make fundamental concepts difficult to comprehend. Furthermore, because high complexity may not be necessary when the constraints of time and accuracy are not as severe, some applications do not require the rigor of a full probabilistic SLAM method. A solution to the localization problem which focuses on clarity and first principles can be beneficial to the engineering/education community and for applications where low cost is favored over high performance. Therefore, we present a straightforward approach to the localization portion of the SLAM problem using scan matching techniques. By reducing complex scan matching from a multidimensional to a one-dimensional problem, localization can be solved in an easily understandable way while minimizing cost and computational requirements. The solution presented here provides estimates of the robot pose and orientation within the confines of a static and simple environment. The techniques utilized are, cross correlation calculations for pure rotation movements around the robot’s center axis combined with simple root mean squared error calculations for translation movements.
Effect of Source Tank Configuration on the Performance of a Hydraulic Ram Pump
Authors: Sharma Ashokkumar M. , Jackson Jacob H. , Centeno Pablo J. , Pidugu Srikanth B. 
Published: January 2022

Abstract
Water scarcity is one of the growing concerns in today’s world. Communities that reside in remote areas or at higher altitudes may encounter water scarcity due to lack of water transport infrastructure affecting drinking, sanitation, farming, and other water-based needs. These issues can be effectively solved by employing a hydraulic ram pump, which does not require electricity to function. Hydraulic ram pumps are powered by the water-head available between the source and the pump unit resulting in a negligible operational cost. The goal of the present study was to modify the source tank configuration of an existing ram pump system to improve its overall performance. A ram pump setup was built using various components viz. valves, PVC pipe and connectors, and digital pressure gauges. The source tank configuration was modified and experimented with using the existing ram pump unit. The study revealed a promising improvement in the overall performance of the hydraulic ram pump. Performance tests using the modified setup showed a better volumetric pump efficiency of nearly 8%. Overall, an approximately 41% increase in the pump efficiency was accomplished with the modified source tank as compared to that observed using the original source tank configuration.