bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Virtual Lab in Assistance of a Fluid Mechanics Laboratory Instruction
Authors: Zhao Yitong , Flanagan Elbon , Abbasi Hamza , Black Kayla , Wang Xin , Cardona Andres 
Published: January 2020

Abstract
Physical laboratory experiments are built to provide students with hands-on opportunities and have long been crucial for engineering training. However, due to the rapid growth in number of enrollments, limited and shared space, undergraduate students have experienced an increasing difficulty gaining valuable hands on experience in the lab. While traditional lab should never be abandoned, adding virtual labs to assist with it could benefit students without the limitation of enrollment capacity or lab availability. In this paper, we discussed a pilot study of developing a virtual fluid mechanics laboratory to supplement existing physical lab exercises.
The virtual lab was designed to enrich students’ lab experience, stimulate interests, and bring more individual exercise time. It was developed to contain two components: a virtual lab tour and a virtual reality (VR) simulated pump experiment. The virtual tours served as a pre-lab instruction tool that provided students with an overview of the fluid mechanics lab. The VR pump experiment replicated the physical experience of performing the physical lab.
Preliminary feedbacks were positive for both components of the virtual lab. Students considered that the virtual tours were very informative and useful, while that the VR pump lab was intuitive and time-saving. This proved that with realistic lab simulations, the virtual lab had great potential to provide students more flexibility to perform hands-on experiment and to develop technical acumen outside of the physical classroom. Further improvement was discussed to implement in the next stage to create more immersive experience in assistance of the lab instruction.
Analysis of a Stokes Flow Past a Cube (Friction and Diffusion Coefficients for Brownian Dynamics Simulations)
Authors: Okada Kazuya , Satoh Akira 
Published: January 2020

Abstract
Magnetorheological properties significantly depend on the regime of aggregate structures. In the case of cubic particles, closely-packed clusters that are significantly different from those for the case of spherical or rod-like particles are formed in the system since magnetic cube-like particles prefer a face-to-face contact with the neighboring particles. Therefore, a cubic particle suspension is expected to exhibit a sufficiently strong magnetorheological effect, which may be investigated by means of Brownian dynamics simulations. However, the translational and rotational diffusion (or friction) coefficients of a cube are not known and indispensable in order to develop this simulation technique. From this background, in the present study, we have analyzed the flow field around a cube in a Stokes flow regime in order to estimate the diffusion (or friction) coefficients of cube-like particles that are required for performing Brownian dynamics simulations of a cubic particle suspension. In the situation of a uniform flow field with a Reynolds number sufficiently smaller than unity, the force acts on the cube only in the flow field direction, and the torque acting on the cube may be regarded as negligible. In the situation of a rotational flow field with a sufficiently low Reynolds number, the torque acts on the cube only in the direction of angular velocity of the rotational flow field, and the force negligibly act on the cube. These characteristics are in significantly similar to those for the case of spheres in a Stokes flow situation. From these results, we may conclude that the diffusion coefficients of cube-like particles can be expressed by introducing a correction factor to those of the spherical particles.
Simulation of MoS2 Nanolayer Membrane Performance for Water Desalination Using ReaxFF
Authors: Oviroh Peter Ozaveshe , Han Jitian , Jen Tien-Chien 
Published: January 2020

Abstract
The use of nanolayer membrane for desalination is an emerging new technology for water purification. Improvements in nanotechnology have led to the development of a variety of nanolayer membranes such as MoS2 and Graphene for water purification that could replace current materials used for reverse osmosis. The reaction of water on 2D monolayer of Molybdenum disulphide (MoS2) was studied using the ReaxFF. Different vacant sites were created such as Mo- and S-vacancy, MoS and S2-divacancy, MoS2 and MoS2-triple for the minimization. The H-O-H and O-H-H molecule demonstrated a stable negative adsorption energy on the different vacancies created, while both the Mo vacancy+H-O-H and the Mo+S2 triple vacancy+O-H-H produced positive binding energies which are unfavourable to adsorption. The molecular dynamics simulation was done to study the factors which could influence membrane performance thereby guide to physical tests. Pore chemistry play a significant role in modulating the water flux and this is explained through the energy barriers.
Monocular Visual Inertial Odometry (VIO) Dataset Collection With a Self-Calibrating Platform for Inertial Measurement Unit (IMU)
Authors: Tian Yuan , Compere Marc 
Published: January 2020

Abstract
In this study, we built a monocular visual inertial odometry (VIO) dataset with a proposed self-calibrating platform for an inertial measurement unit (IMU). For a learning-based method, lack of database is the biggest limitation. One goal of this study is to generate a high-quality VIO database. Meanwhile, a properly calibrated inertial measurement unit (IMU) is critical for improving VIO system accuracy and precision. However, a professional IMU calibration tool is usually expensive and large. The proposed self-calibrating platform shows its benefits in eliminating the manual work in calibration and reducing the cost of the expensive platform, which brings more opportunities to students and researchers. This self-calibrating system was useful for collecting monocular visual inertial odometry datasets while driving. . The calibrated IMU generates 14 numbers at 100Hz: time, 3-axis accelerometer measurements, 3-axis gyroscope measurements, 3 Euler angles, and 4 quaternions. This VIO system is composed of a monocular camera, GoPro Hero 3, an IMU, BNO055, and a GPS, ANT-555. The sensors are mounted on a John Deere Gator™ Full-Size Crossover Utility Vehicle and are operated on an Intel NUC, a mini-size computer. The final dataset contains monocular images, IMU measurements, and GPS outputs.
Design of a Turbopiston Pump Guided by Computational Analysis
Authors: Wang Ting , Rousset Patrick W. 
Published: January 2020

Abstract
An innovative pump, TurboPiston Pump (TPP), has been invented to incorporate the merits of centrifugal, axial, and positive displacement pumps. The TPP is designed to deliver large flow rates with a potential at high pressure of up to 1000 psia with one stage. To improve the original design, an understanding of the flow behavior inside the pump is needed. The objective of this study is to simulate the flow field inside the pump and study its performance to guide the design process. This study includes modeling the pump with the transient sliding mesh scheme using a commercial computational fluid dynamics solver, ANSYS/FLUENT. The flow pattern, static pressure distribution, and total pressure losses are calculated and analyzed. The regions of high total pressure losses and potential creation of cavitation are identified. A plastic demonstration model and a metal prototype have been fabricated based on the result of the CFD analyis.
A Hypothesized Mechanistic Model of Longitudinal Wall Motion at the Common Carotid Artery
Authors: Hao Zhili , Reynolds Leryn , Herre John M. 
Published: January 2020

Abstract
In light of recently recognized independent clinical values of longitudinal wall motion ux(t) at the common carotid artery (CCA) and the struggle on appropriate arterial indices for interpreting ux(t), this paper hypothesizes a mechanistic model of ux(t) and explores clear implications of the antegrade amplitude ux0-ante and retrograde amplitude ux0-retro of ux(t) in systole to the cardiovascular (CV) system. By examining findings on ux(t) and other relevant findings through the lens of the engineering essence of ux(t), a mechanistic model of ux(t) is hypothesized: the left ventricle (LV) base rotation is the excitation source for initiating the longitudinal elastic wave propagating along the arterial tree; wall shear stress at an artery serves as a local external source for supplying energy to the longitudinal elastic wave; and longitudinal elasticity at the arterial wall dictates the wave propagation velocity. Integrating the mechanistic model with findings on ux(t) gives rise to interpretation of ux0-ante and ux0-retro for their clear implications: longitudinal elasticity Exx at the common carotid artery (CCA) is estimated from ux0-ante, and ux0-retro is an inverse indicator of the maximum base rotation of the LV and a positive indicator of longitudinal elasticity at the ascending aorta (AA). For the first time, this model reveals the mechanisms underlying those statistical-based findings on ux(t).
Finite Element Analysis of the Effect of Porosity on the Plasticity and Damage Behavior of Mg AZ31 and Al 6061 T651 Alloys
Authors: Perkins Allen , Yang Wenhua , Liu Yucheng , Chen Lei , Yenusah Caleb 
Published: January 2020

Abstract
Porosity has been known to have a profound effect on a material’s mechanical properties, often weakening the material. Highly porous metallic materials prove troublesome for supporting a load-based structure due to the voids that are present throughout the microstructure of the material. In this study, the previously developed ISV damage plasticity model is used to investigate the effect of the porosity on aluminum alloy 6061-T651 and magnesium alloy AZ31 through finite element analysis (FEA). It is determined that porosity has a profound impact on the strength of the aluminum alloy and much lesser effect on the magnesium alloy. Porosity is also shown to affect other properties of the materials, such as the hardness and pore growth.
Designing a Better Virtual Reality (VR) Experience
Authors: Asencio Armand J. , Graham Ian C. , Korsen Ryan , Ma Guohua , McCusker James 
Published: January 2020

Abstract
Virtual reality (VR) is a great new technology which has extensive applications, and it is imperative that there is a way to use VR comfortably. This will allow VR to become an everyday tool, creating a more interactive world. With more VR integration new technologies can be created and allow VR to expand further into fields like therapy or military training. However, VR comes with some unfortunate side effects. The cybersickness that many people experience when using a VR system has been shown to trigger a thermoregulatory response that causes sweating, the sensation of being excessively hot, as well as nausea. These symptoms of cybersickness make it uncomfortable to use a VR system for any long period of time. In order to combat this, the authors present a device which can effectively cool the user to extend the time duration a user can comfortably use a VR system.
Estimating Pacejka (PAC2002) Tire Coefficients for Pneumatic Tires on Soft Soils With Application to BAJA SAE Vehicles
Authors: Saunders Amanda , White Darris , Compere Marc 
Published: January 2020

Abstract
BAJA SAE is an engineering competition that challenges teams to design single-seat all-terrain vehicles that participate in a vast number of events, predominately on soft soils. Efficient performance in the events depends on the traction forces, which are dependent on the mechanical properties of the soil. To accurately model vehicle performance for each event, a model of the tire traction performance is required, and the tire model must be incorporated with a vehicle dynamics simulation. The traction forces at the soil-tire interface can be estimated using the Bekker-Wong stress integration method. However, commercially available vehicle dynamics simulation software, with a focus on on-road vehicles, does not utilize Bekker-Wong parameters. The Pacejka Magic Tire (MT) Formula is a common method for characterizing tire behavior for on-road vehicles. The parameters for the Pacejka MT Formula are usually produced by curve fitting measured tire data. The lack of available measured off-road tire data, as well as the additional variables for off-road tire performance (e.g. soil mechanics), make it difficult for BAJA SAE teams to simulate vehicle performance using commercial vehicle simulation tools. This paper discusses the process and results for estimating traction performance using the Bekker-Wong stress integration method for soft soils and then deriving the Pacejka coefficients based on the Bekker-Wong method. The process will enable teams to use the Pacejka Magic Tire Formula coefficients for simulating vehicle performance for BAJA SAE events, such as the hill climb, (off-road) land maneuverability, tractor pull, etc.
A First Principle Study on the Adhesion and Stability of Al203 (0001)/Pt (111) Film Interface
Authors: Mohlala Lesego M. , Coetzee Rigardt A. M. , Jen Tien-Chien , Olubambi Peter A. 
Published: January 2020

Abstract
The first-principles calculation with density functional theory (DFT) is a powerful tool for studying solid-solid interfacial behaviour at the atomic scale. In this study, the interfacial properties of Al2O3 (0001)/Pt (111) atomic layer deposited film, such as adhesion strength, fracture toughness; interfacial energy and stability are investigated using the Cambridge Serial Total Energy Package (CASTEP) code in Material Studio. Two interface models with different Pt (111) configurations are investigated to elucidate their influence on the adhesion strength and interfacial stability. Moreover, the density of states plots (PDCS) is presented to further comprehend the electronic structures and bonding nature of interface. The work of adhesion obtained from the calculations is 2.836 J/m2 and 2.694 J/m2 for model 1 and 2 respectively. In addition, the interfacial energy for model 1 (−6.429J/m2) is smaller than that of model 2 (−5.881J/m2). The calculated results indicate that model 1 possesses high interface strength and thermodynamic stability. The lattice mismatch was calculated to be 10.46%, suggesting the formation of semi-coherent interface formation with coherent structural interface structures and misfit dislocation networks (MDN). The results obtained from the density functional theory simulations were compared and correlated with available literature.
Research on the Diagnosis Method of Reciprocating Compressor Valve Leakage Fault With Vibration Signal
Authors: Zhang Zetian , Hou Chenggang , Li Xueying , Zhang Zhaoning 
Published: January 2020

Abstract
Reciprocating compressor is one of the key machines in chemical and petrochemical industries. The most common failure mode in the compressor is valve leakage. Generally, leakage fault is considered to be of little harm to machines. However, it was found that the serious leakage of the valve would cause abnormal bending vibration of the piston rod and accelerate the formation of fatigue cracks. Most researchers utilized the signal of cylinder dynamic pressure, valve temperature or acoustic emission to diagnose valve leakage fault. However, each of these methods has disadvantages.
In this paper, a new method is proposed to diagnose valve leakage fault using vibration signal. The main idea is that the severity of valve leakage can be assessed by analyzing energy of the main frequency band during compression process and the delay of discharge valve opening. Firstly, the vibration signal in the time domain is segmented into several angle-domain signals according to the keyphasor signal. Each of the angle-domain signals corresponds to one cylinder working cycle. Then, the time-frequency analysis is conducted with the Gaussian window, and the main energy frequency band and the compression process are determined. Filtering the signal with a bandpass filter based on the main energy frequency band, and the root-mean-square (RMS) of the filtered signal during compression process is calculated in a crank revolution. Besides, the angle of discharge valve opening is detected. Based on the two indicators, the severity of valve leakage can be estimated.
To verify the effectiveness of the method, keyphasor of the flywheel, cylinder dynamic pressure and vibration acceleration of valve are acquired on a double-acting oil-free air compressor under different degrees of suction valve leakage. The experimental results and analysis show that the proposed method can well identify the valve leakage fault, even in the case of weak leakage, and is very effective in quantifying the severity of leakage.
Robust Design of a Test Bench for PHM Study of Ball Screw Drives
Authors: Bertolino A. C. , De Martin A. , Jacazio G. , Mauro S. , Sorli M. 
Published: January 2020

Abstract
Over the last two decades, one of the most prominent research themes in the aerospace community involved the definition of “more electric aircrafts”. For flight control systems the trend is to replace the traditional electro-hydraulic solution with electro-mechanical actuators. However, safety issues severely hinder the diffusion of this technology. A possible breakthrough in this field can be the development of robust PHM techniques to anticipate the occurrence of failures.
Ball screws feature one of the highest failure rate within EMAs’ mechanical components. Since their accurate modeling is fairly complex, experimental results are needed to support simulation outcomes to help in the definition of reliable health monitoring schemes.
This paper presents the model-based design of a novel test bench intended for PHM analyses of ball screw drives. At first the test bench layout is introduced and compared to the state of the art. A high-fidelity model of the test bench is presented and exploited to perform a Monte Carlo simulation campaign with the goal to characterize its behavior versus measure and process noise in presence of varying size backlash. Finally, a test procedure for backlash identification is defined.
Cure Monitoring of Adhesive for Composite/Metal Bonded Structure Based on Highly Nonlinear Solitary Waves
Authors: Bin Wu , Mingzhi Li , Xiucheng Liu , Heying Wang , Cunfu He , Zongfa Liu 
Published: January 2020

Abstract
In this paper, a nondestructive evaluation technique based on highly nonlinear solitary waves (HNSWs) is proposed to monitor the curing process of adhesive for composite/metal bonded structure. HNSWs are mechanical waves with high energy intensity and non-distortive nature which can form and propagate in a nonlinear system, such as a one-dimensional granular chain. In the present study, a finite element model of the one-dimensional granular chain is established with the commercial software Abaqus, to study the reflection behavior of HNSWs at the interface between the particle at the end of chain and the sample. The simulation results show that the time of flight (TOF) of the primary reflected solitary wave decreases with the stiffness of the sample increases, and the amplitude ratio (AR) between the primary reflected solitary wave and the incident solitary wave increases. An HNSWs transducer based on the one-dimensional granular chain is designed and fabricated. The relationship between the characteristic parameters of the primary reflected solitary wave (TOF and AR) and the curing time of adhesive for a composite/metal bonded structure is experimentally investigated. The experiment results suggest that the TOF decreases and the AR increases as the epoxy cures. The experimental results are in good agreement with the simulation results. This study provides a new characterization method for monitoring the curing process of adhesive for composite/metal bonded structure.
Structural and Mechanical Analysis of Silane Compounds Coatings on AISI 304
Authors: Baruwa Akinsanya Damilare , Akinlabi Esther Titilayo , Oladijo O. P. , Mwema Frederick 
Published: January 2020

Abstract
The structures and mechanical strength existing in three different hydrophobic silane compounds, Henicosyl-1,1,2,2-tetrahydrododecyltrichlorosilane (FDDTS), Tridecafloro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) and [Tris(trimethylsiloxy)silyethyl]dimethylchlorosilane (Alkyl) under same deposition conditions were studied and presented in this paper. The effect of the chemical composition on the mechanical strength and the structural evolutions as related to chlorosilane was inquired. The structures were investigated by using field emission scanning electron microscope (FESEM), atomic force microscope (AFM) and surface profiler while the nature of the mechanical strength was determined from nanoindentation and nano scratch. From the data obtained, the FDDTS showed to be denser in structures than both Alkyl and FOTS. The root-mean-square (RMS) roughness exhibited by FDDTS was larger when compared to the other two silanes. The mechanical ability shows that the FDDTS has the largest maximum penetration load as well as highest scratch resistance. Overall, the FDDTS would perform excellently in the applications where combine hard and wear resistance organic coating is required.
Conversion of a Heavy-Duty Diesel Engine to Natural-Gas Spark-Ignition Operation: Test Bench Development
Authors: Liu Jinlong , Dumitrescu Cosmin E. , Bommisetty Hemanth , Ulishney Christopher 
Published: January 2020

Abstract
Partial conversion of the large inventory of diesel engines to natural gas (NG) spark-ignition (SI) will reduce U.S. dependence on imported petroleum and enhance national energy security. This paper describes the methodology used to retrofit such an engine as well as the experimental setup used to investigate and optimize the conversion, including engine modifications, coupled dynamometer, engine control, and data acquisition system. Low-pressure gas injectors placed upstream of the intake valve produced a homogeneous combustible mixture inside the cylinder. The final setup was verified via experiments that changed the equivalence ratio from 0.7 to 1.0 at 900 rpm, using methane as a natural gas surrogate. The results showed that despite the higher compression ratio (which increased in-cylinder pressure and temperature at spark timing compared to conventional SI engines), a high-energy spark plug was necessary to produce robust and repeatable ignition. In addition, the moderate compression ratio of the converted engine (13.3) resulted in knock-free operation at all equivalence ratios. Finally, the reliable and stable operation at the investigated conditions (COVIMEP &lt; 1.5%) and low rate of pressure rise (&lt; 3 bar/deg CA) support this solution for converting diesel engines to NG SI operation, at least for the conditions investigated here. The trend of engine-out emissions agreed well with existing studies, which also validated the design of the test cell for optimizing engine efficiency and sampling emissions.