bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Mass Distribution on Falling Cylindrical Particles at Intermediate Reynolds Numbers
Authors: Angle Brandon R. , Rau Matthew J. , Byron Margaret L. 
Published: November 2019

Abstract
In natural sedimentation, many particles of interest are both large and nonspherical. Some common particle types (e.g. naturally occurring aggregates) do not have a uniform mass distribution. As a result, the centers of mass and buoyancy are not co-located, leading to more complex settling dynamics. Here we investigated the orientation and terminal velocity of freely falling cylinders, in which the mass distribution was either constant (uniform-density, UD) or bipartite, undergoing a step function halfway along the length (compound-density, CD). Cylinders had relatively low aspect ratios (1 &lt; AR &lt; 4), and fell at intermediate Reynolds numbers (of order 100). The cylinders, initially horizontal, were released at the top of a tall hexagonal still-water tank, and imaged by a high-speed camera. Two low-speed cameras simultaneously captured 1) full cylinder trajectory and 2) landing position. We recorded the terminal velocity, fall orientation, and landing site of each cylinder. Results showed significant differences in the settling characteristics of uniform- vs. compound-density cylinders. UD cylinders of AR = 1 fell broadside initially, whereas AR = 1 CD cylinders fell vertically. However, both cases showed oscillation in cylinder orientation upon descent. UD cylinders with AR = 2 and AR = 4 consistently fell broadside, with minimal cylinder axis oscillation. CD cylinders with AR = 2 fell with two different modes. In mode 1, cylinders rotated 90° from their initial orientation before beginning to oscillate about the vertical axis. In mode 2, cylinder orientation remained constant at a slight angle from the horizontal. This mode was also observed in the CD AR = 4 cylinders, which fell at a constant (tilted) orientation angle and moved horizontally as they fell. The landing sites for all CD cylinders were biased toward the side of the target where the denser end of the cylinder was initially oriented, whereas UD cylinders landed in a uniform distribution around the tank center. In general, cylinders with the smallest vertical projected area fell with the greatest terminal velocity; however, the mechanisms controlling orientation remain unclear. Our results have important implications for predicting the settling behavior of naturally-occurring particles, and lay the groundwork for further study of particles settling in complex flows such as turbulence. Given our results in still water, the interplay between the buoyant torques created by the offset between the center of mass and center of volume are likely to strongly impact particle motion in turbulence.
Hydrodynamics and Flow Characterization of Tuna-Inspired Propulsion in Forward Swimming
Authors: Wang Junshi , Tran Huy , Christino Martha , White Carl , Zhu Joseph , Lauder George , Bart-Smith Hilary , Dong Haibo 
Published: November 2019

Abstract
A combined experimental and numerical approach is employed to study the hydrodynamic performance and characterize the flow features of thunniform swimming by using a tuna-inspired underwater vehicle in forward swimming. The three-dimensional, time-dependent kinematics of the body-fin system of the underwater vehicle is obtained via a stereo-videographic technique. A high-fidelity computational model is then directly reconstructed based on the experimental data. A sharp-interface immersed-boundary-method (IBM) based incompressible flow solver is employed to compute the flow. The primary objective of the computational effort is to quantify the thrust performance of the model. The body kinematics and hydrodynamic performances are quantified and the dynamics of the vortex wake are analyzed. Results have shown significant leading-edge vortex at the caudal fin and unique vortex ring structures in the wake. The results from this work help to bring insight into understanding the thrust producing mechanism of thunniform swimming and to provide potential suggestions in improving the hydrodynamic performance of swimming underwater vehicles.
Characterization of Aggregate Disruption Using Organic Marine Particles and Particle Tracking Measurements in Rotating/Oscillating Aggregation Tanks
Authors: Song Yixuan , Rau Matthew J. 
Published: November 2019

Abstract
The fate of particulate matter in the ocean is determined in large part by its size and settling rate. Disaggregation, caused by turbulence-induced shear, acts to fracture or erode large particles into slower-settling sub-aggregates and primary particles. The strength and breakup response of organic marine aggregates (i.e. marine snow particles consisting of phytoplankton) is poorly understood, limiting our ability to accurately predict marine particle transport effects on the global carbon cycle. A study was conducted to enable the investigation of disaggregation effects on these organic marine particle aggregates. Due to the fragile nature of the Phytoplankton cells and their resulting aggregates, test facilities that do not rely on external sampling or pumps are required. A novel rolling aggregation tank was developed that can both aggregate phytoplankton cells under varying hydrodynamic conditions and then expose them to calibrated shear forces using laminar oscillating flow. The theory behind the operation of this tank is presented along with the necessary operating conditions to create stable regions within the tank where particle settling effects are minimal but shear is still representative of values expected in the open ocean. Phytoplankton was cultured in the laboratory to create simulated marine snow particles in the open ocean for disaggregation experiments. The procedure to calculate and track the shear-history of each aggregate is described and how the data generated from this facility will be used to quantify disaggregation parameters relevant for population balance modeling is discussed.
An Analytical and Modular Software Workbench for Solving Kinematics and Dynamics of Series-Parallel Hybrid Robots
Authors: Kumar Shivesh , Mueller Andreas 
Published: November 2019

Abstract
Parallel mechanisms are increasingly being used as modular subsystem units in various robots and man-machine interfaces for their superior stiffness, payload-to-weight ratio and dynamic properties. This leads to series-parallel hybrid robotic systems which are difficult to model and control due to the presence of various closed loops. Most model based kinematic and dynamic modeling tools resolve loop closure constraints numerically and hence suffer from inefficiency and accuracy issues. Also, they do not exploit the modularity in robot design. In this paper, we present a modular and analytical approach towards kinematic and dynamic modeling of series-parallel hybrid robots. This approach has been implemented in a software framework called Hybrid Robot Dynamics (HyRoDyn) and its application is demonstrated with the help of a series-parallel hybrid humanoid robot recently developed at DFKI-RIC.
Direct Label Free Detection of Orchid Virus Using a Micro/Nano Hybrid Structured Biosensor
Authors: Wang Wei-Jhen , Lee Chia-Hwa , Li Chin-Wen , Liao Stephen , Jan Fuh-Jyh , Wang Gou-Jen 
Published: November 2019

Abstract
In this study, a label-free detection approach for effective detection of the odontoglossum ringspot virus (ORSV) infected orchids has been developed. We used semiconductor fabrication process to fabricate 1,810 micro/nano hybrid structured sensing electrodes on a 8 inch reclaimed wafer. The self-assembled monolayer (SAM) process was then employed to sequentially modify the electrode surface with 11-mercaptoundecanoic acid (11-MUA), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/ N-hydroxysuccinimide (NHS), anti-ORSV, and ORSV. EIS was conducted for the ORSV concentration detection. Experimental results demonstrated that the ORSV concentration in a virus infected orchid leaf could be effectively detected. When compared with the ELISA kit, our device possesses a wider linear detection range (0.5–50,000 ng/mL) and a higher sensitivity. The specificity of our device on ORSV detection was also confirmed. Our sensing device retains advantages, such as label-free, lower amounts of the antibody and target sample required, low detection time, and a wider linear detection range. Those results imply the feasibility of our sensing device in field applications.
The Sketch Quality Bias: Evaluating Descriptions of Product Ideas With and Without Visuals
Authors: Kwon Jieun , Kudrowitz Barry 
Published: November 2019

Abstract
Idea visualization is a critical tool in a product development process. From early idea sketches to 3D prototyping, designers often visualize ideas for themselves and others in the process of feedback and refinement. The viewers of these ideas (clients, investors, collaborators, and consumers) rely on these visual presentations to evaluate the potential of a designer’s idea. Although sketching ideas is common practice in the product design industry, little is known about the extent to which presentation quality influences viewers’ evaluations of ideas. This paper examines the power of product sketch quality on perceived idea evaluation. In the present study, a total of 400 participants were asked to evaluate a set of product ideas presented with and without a sketch. The results show that when product sketches were presented, the participants were heavily influenced by the sketch quality when evaluating the value of the idea, and the concept ratings were somewhat different when sketches were not present. The results imply that viewers’ perceptions of idea worthiness are possibly dependent on how an idea is visually presented.
Dynamic Analysis and Parametric Resonance of a Fast Projection System
Authors: Gao Hao , Yang Bingen 
Published: November 2019

Abstract
Fast projection systems are seen in various engineering applications, including weaponry systems. This work is concerned with the vibration of coupled gun barrel-bullet systems. The vibration of the muzzle end of a gun barrel (launching structure) is critical to shooting accuracy and launching safety. Under a rapid and repeated launching process, the launching structure may experience parametric resonance that is induced by accelerating projectiles. In this paper, a mathematical model of the coupled gun barrel-bullet is developed. In the development, the gun barrel is modeled by a cantilever beam; the projectiles are modeled as moving rigid bodies with time-varying velocities; and the dynamic coupling between the gun barrel and projectiles are described by pairs of springs and dampers. With this model, the dynamic response of the coupled system is determined through use of an extended solution domain (ESD) technique, which facilitates systematic solution of the dynamic response of the coupled beam-rigid body system. Numerical results show that parametric resonance can be induced in the launching structure, which is highly dependent on system parameters and projectile launching rate.
On Period-1 and Period-2 Motions of a Jeffcott Rotor System
Authors: Xu Yeyin , Luo Albert C. J. 
Published: November 2019

Abstract
In this paper, the semi-analytical solutions of period-1 and period-2 motions in a nonlinear Jeffcott rotor system are presented through the discrete mapping method. The periodic motions in the nonlinear Jeffcott rotor system are obtained through specific mapping structures with a certain accuracy. A bifurcation tree of period-1 to period-2 motion is achieved, and the corresponding stability and bifurcations of periodic motions are analyzed. For verification of semi-analytical solutions, numerical simulations are carried out by the mid-point scheme.
Design and Simulation Analysis of Vibration Energy Harvesting System Based on ADAMS
Authors: Zhu Ziheng , Xu Lin , Abdelkareem Mohamed A. A. , Zou Junyi , Mi Jia 
Published: November 2019

Abstract
With the recent energy crisis, the new energy harvesting technologies have become one of the hot spots in engineering academic research and industrial applications. By its wide range of application fields, vibration energy harvesting technologies have been gradually developed and utilized in which an efficient and stable harvester technology is one of the recent key problems. In order to improve energy harvesting efficiency and reduce energy loss caused by motor inertial commutation, many mechanical structures or hydraulic structures that convert reciprocating vibration energy into single direction rotation of motor are proposed. Although these methods can improve energy harvesting efficiency, they can have negative effects in some cases, especially in the case of vibration energy harvesting from human beings. This paper proposes a vibration harvesting mechanism with mechanical rectification filter function applied to backpack. The prototype model of the system was established in SolidWorks and imported into ADAMS. Thereafter, dynamic analyses of mechanical rectification filtering characteristics and meshing characteristics of one-way clutch were simulated in ADAMS. Based on ADAMS, parametric design analysis and its influence on the mechanical rectification characteristics were investigated. The simulation results were validated by bench test results. Simulation results is done by ADAMS and the results match well with bench test results.
Precision Evaluation for Cycloidal Gears
Authors: Shih Yi-Pei , Lo Shih-Hung , Sheen Bor-Tyng , Tsai Yi-Hung 
Published: November 2019

Abstract
Cycloidal gear drives have advantages of compact sizes, large reduction ratios, and low backlash. They are particularly suitable for applications in precise positioning and large output torque, such as industrial robots and machine tools. Up to now, the effective precision evaluation of cycloidal gears is lacked in commercial measuring devices. The main goal of this paper is to propose precision evaluation for cycloidal gears. The research focuses on (1) establishing a mathematical model of cycloidal gear and (2) developing a method for precision evaluation of cycloidal gear. The evaluation items cover the following areas of tooth profile and thickness errors, pitch errors, accumulation pitch errors and runout. The profile points measured by a coordinate measuring machine are divided into tooth groups and then formulated as curves using a B-spline curve fitting technique. The precision of cycloidal gear can be further evaluated. A case study on Nabtesco RV-25N is displayed to verified the correctness of the proposed method.
Modeling, Simulation and Assessment of a Hybrid Electric Ferry: Case Study for Mid-Size Ferry
Authors: Feng Yanbiao , Chen Li , Dong Zuomin 
Published: November 2019

Abstract
The hybrid electric propulsion system presents a feasible and attractive fuel cost and emission reduction solution for heavy-duty transportation applications, particularly for large marine vessels. The model of a specially designed hybrid electric powertrain system has been introduced. The work uses the acquired operation and power load patterns of the BC Ferries Skeena Queen as a case study to demonstrate the fuel cost and emission reduction potentials of the electrified technology by comparing results from three powertrain alternatives: traditional diesel engine, diesel-electric, and series hybrid electric. The results showed that the electrification and hybridization could significantly reduce both fuel cost and harmful emissions. The series hybrid electric powertrain system has been targeted in this work due to its relatively small powertrain architecture difference from the traditional diesel-electric powertrain, and the ease of control development.
Addressing Information Gaps in Household Waste Sorting Using a Mobile Application
Authors: Pagels Kelvin Østergaard , Rasmussen Mikkel Bayard , Ramanujan Devarajan 
Published: November 2019

Abstract
The Danish government has outlined a target of recycling 50% of total household waste by the year 2022. Improving household waste sorting is an important consideration towards achieving this goal. This paper focuses on understanding existing waste sorting practices among Danish residents and exploring whether a mobile application can help address any existing information gaps. We conducted a preliminary survey (N = 180) that assessed preference for sorting strategies and the types of waste sorted. Following this a more detailed survey was conducted (N = 357) that assessed residents’ motivation to sort household waste, knowledge of local sorting requirements, information gaps that prevent effective sorting, and need for specific features in a mobile application. Results show over one-third of respondents felt they needed additional waste sorting information. Respondents had fewer inaccuracies disposing items within a single waste stream (e.g., electronics waste) compared to items with mixed waste streams (e.g., milk carton with a plastic cap). Based on these findings we propose the design of a mobile application that can potentially improve household waste sorting.
Topology Optimization of Compliant Mechanisms Based on Interpolation Meshless Method and Geometric Nonlinearity
Authors: Zhang Yonghong , Zhao Zhenfei , Zhang Yaqing , Ge Wenjie 
Published: November 2019

Abstract
In order to prevent mesh distortion problem arising in topology optimization of compliant mechanism with massive displacement, a meshless Galerkin method was proposed and studied in this paper. The element-free Galerkin method (EFG) is more accurate than the finite element method, and it does not need grids. However, it is difficult to impose complex boundaries. This paper presents a topology optimization method based on interpolation meshless method, which retains the advantages of the finite element method (FEM) that is easy to impose boundary conditions and high accuracy of the meshless method. At the same time, a method of gradually reducing step is proposed to solve the problem of non-linear convergence caused by low-density points in topology optimization. Numerical example shows that these techniques are valid in topology optimization of compliant mechanism considering the geometric nonlinearity, and simultaneously these techniques can also improve the convergence of nonlinearity.
Feasibility Study of a Capacitive MEMS Filter Using Electrostatic Levitation
Authors: Pallay Mark , Towfighian Shahrzad 
Published: November 2019

Abstract
We introduce a capacitive MEMS filter that uses electrostatic levitation for actuation and sensing. The advantage of this electrode configuration is that it does not suffer from the pull-in instability and therefore tremendously high voltages can be applied to this system. A large sensing voltage will produce a large output signal, which boosts the signal to noise ratio. The filter outputs about a 110mV peak-to-peak signal when operated at 175V, and can be boosted to 175mV by increasing the voltage to 250V. Because pull-in is eliminated, voltages much higher than 250V can be applied. An outline of the filter design and operating principle is discussed. A model of the filter is derived and analyzed to show the mechanical response and approximate peak-to-peak signal output. This study shows the feasibility of a capacitive sensor that is based on electrostatic levitation, and outlines the advantages it has over traditional parallel-plate electrode configurations. This design is promising for signal signal processing applications where large strokes are important.
Eliminating Peak Impact Forces by Customizing the Passive Foot Dynamics of Legged Robots
Authors: Rond Jesse J. , Cardani Michael C. , Campbell Matthew I. , Hurst Jonathan W. 
Published: November 2019

Abstract
Impact forces are a destructive, yet common occurrence in legged locomotion. Every step produces a collision when the leg’s inertia immediately stops upon ground contact. This results in peak impact forces and high frequency vibrations that resonate through the system, damage components, and complicate control algorithms. Rubber or other damping material is the assumed solution for mitigating these impacts. However, we show the benefit of using foot springs where both stiffness and maximum compression are customized to the leg. Such springs eliminate peak impact forces by gradually bringing the leg’s inertia to rest. The maximum compression point (i.e. a hard stop) then provides a rigid surface during stance. We provide a methodology for designing this passive dynamic foot that is validated through simulation and physical testing. Our results show this methodology reduces rigid body impacts and foot vibrations in a way traditional methods, reliant upon rubber or damping, are yet to achieve.
The Trajectory of Psychological Safety in Engineering Teams: A Longitudinal Exploration in Engineering Design Education
Authors: Miller Scarlett , Marhefka Jacqueline , Heininger Katie , Jablokow Kathryn , Mohammed Susan , Ritter Sarah 
Published: November 2019

Abstract
Although teamwork is being integrated throughout engineering education because of the perceived benefits of teams, the construct of psychological safety has been largely ignored in engineering research. This omission is unfortunate, because psychological safety reflects collective perceptions about how comfortable team members feel in sharing their perspectives and it has been found to positively impact team performance in samples outside of engineering [20]. Engineering team research has also been crippled by “snap-shot” methodologies and the resulting lack of investigation into the dynamic changes that happen within a team over course projects. This is problematic, because we do not know when, how, or what type of interventions are needed to effectively improve “t-shaped” engineering skills like teamwork, communication, and engaging successfully in a diverse team. In light of these issues, the goal of the current study was to understand how psychological safety might be measured practically and reliably in engineering student teams over time. In addition, we sought to identify the trajectory of psychological safety for engineering design student teams and identify the potential factors that impact the building and waning of psychological safety in these teams. This was accomplished through a 4-week study with 12 engineering design teams where data was captured at six time points. The results of this study present some of the first evidence on the reliability of psychological safety in engineering student populations. The results also help begin to answer some difficult fundamental questions on supporting team performance in engineering education.
A General Purpose Formulation for Nonsmooth Dynamics Including Large Rotations: Application to the Woodpecker Toy
Authors: Galvez Javier , Cosimo Alejandro , Cavalieri Federico J. , Cardona Alberto , Brüls Olivier 
Published: November 2019

Abstract
The aim of this work is to extend the finite element multibody dynamics approach to problems involving frictional contacts and impacts. Since rigid bodies and joints involve bilateral constraints, it is important to avoid any drift phenomenon. Therefore, the nonsmooth generalized-α method is used, which imposes the constraints both at position and at velocity levels. Its low intrusiveness allows one to reuse an existing library of elements without major modifications. The study of the woodpecker toy dynamics sets up a good example to show the capabilities of the nonsmooth generalized-α within the context of a general finite element framework. This example has already been studied by many authors who generally adopt a model with a minimal set of coordinates and small rotations. We show that using a finite element approach, the equations of motion can be assembled automatically, and large rotations can be easily considered.