bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systematics of tardigrada: A reanalysis of tardigrade taxonomy with specific reference to Guil et al. (2019)
Authors: Fleming James F. , Arakawa Kazuharu 
Published: January 2021

AbstractThe Tardigrada are a clade with a disputed and complex taxonomy. The three traditional tardigrade classes are the Heterotardigrada, Eutardigrada and the dubious, monotypic Mesotardigrada. A recent molecular study by Guil et al (Zoologica Scripta, 48, 2019, 120) suggested that the Apochela, previously considered an order of Eutardigrada, should become a new class, Apotardigrada, with the Parachela becoming THE new Eutardigrada. This new diagnosis was presented alongside compelling morphological evidence. Here, we test the assumptions of the molecular evidence for Apotardigrada by analysing tardigrade 18S and 28S data under four separate conditions, along with new BUSCO data, across both Bayesian‐ and maximum‐likelihood phylogenetic approaches. We found variable conclusions regarding the status of Apotardigrada could be drawn by comparing the ribosomal RNA and BUSCO results, and caution against using branch length data to determine taxonomic hierarchy.
Bio-Inspired Vibration Isolation: Methodology and Design
Authors: Yan Ge , Zou Hong-Xiang , Wang Sen , Zhao Lin-Chuan , Wu Zhi-Yuan , Zhang Wen-Ming 
Published: January 2021

AbstractVarious bio-inspired vibration isolators have been emerged in recent decades and applied successfully in the protection of sensitive components, improvement of operating comfort, enhancement of control accuracy, etc. They are generally developed by exploiting favorable nonlinearities in biological structures. The main contribution of this work is to provide a comprehensive review of recent studies on the bio-inspired isolators. The methodology of bio-inspired vibration isolation is proposed from the perspective of mechanics based on the elemental theory and design principles. The key isolation mechanisms are classified into three categories according to different dominant forces: stiffness adjustment mechanism, auxiliary mass mechanism, and damping mechanism, respectively. Some representative designs, performance analyses, and practical applications of each type of bio-inspired isolators are also provided. In bio-inspired isolators with variable stiffness, the inherent structural performances can be adjusted to deal with variation in external load. The auxiliary mass mechanism utilizes nonlinear inertial effects to achieve ultralow frequency vibration isolation. Unique damping mechanism of bio-inspired structures is often studied to protect devices and equipment from impact loads. Bio-inspired vibration methods can also be applied in active/semi-active control systems with advantages of low energy consumption and high robustness. Finally, the review ends with conclusions, which highlight resolved and unresolved issues and provide a brief outlook on future perspectives. This review aims to give a comprehensive understanding of bio-inspired isolation mechanism. It also provides guidance on designing new bio-inspired isolators for improving their vibration isolation performance.
Origami-Based Bistable Metastructures for Low-Frequency Vibration Control
Authors: Zhang Mingkai , Yang Jinkyu , Zhu Rui 
Published: January 2021

Abstract
In this research, we aim to combine origami units with vibration-filtering metastructures. By employing the bistable origami structure as resonant unit cells, we propose metastructures with low-frequency vibration isolation ability. The geometrical nonlinearity of the origami building block is harnessed for the adjustable stiffness of the metastructure’s resonant unit. The quantitative relationship between the overall stiffness and geometric parameter of the origami unit is revealed through the potential energy analysis. Both static and dynamic experiments are conducted on the bistable origami cell and the constructed beam-like metastructure to verify the adjustable stiffness and the tunable vibration isolation zone, respectively. Finally, a two-dimensional (2D) plate-like metastructure is designed and numerically studied for the control of different vibration modes. The proposed origami-based metastructures can be potentially useful in various engineering applications where structures with vibration isolation abilities are appreciated.
Tuning the Mechanical and Geometric Properties of Electrochemically Aligned Collagen Threads Toward Applications in Biohybrid Robotics
Authors: Sun Wenhuan , Paulovich Jason , Webster-Wood Victoria 
Published: January 2021

AbstractElectrochemically aligned collagen (ELAC) threads fabricated by the isoelectric focusing (IF) of collagen have previously shown potential in tissue engineering and more recently in the fabrication of biohybrid robot structures. For applications in biohybrid robotics, ELAC structures are needed that are both robust and compliant enough to facilitate muscle actuation. However, studies on the effects of IF parameters, and the interactions of such fabrication parameters, on the mechanical and geometric properties of resulting ELAC threads have not been previously found in literature. Understanding the impact of these manufacturing parameters on the material properties is critical to facilitate biohybrid robot design. In this study, the effects of IF duration, IF voltage, and collagen solution concentration were investigated and showed statistically significant effects on adjusting ELAC properties via single-factor experiments. The interactions between parameters exhibited significant joint effects on ELAC property tuning through two-factor experiments. Scanning electron microscopy and 2,4,6-trinitrobenzenesulfonic (TNBS) assays revealed the correlation between high mechanical properties and a combination of low porosity and high degree of crosslinking. By simply tuning IF parameters without changing other fabrication steps, such as crosslinker concentration, ELAC threads with a wide range of mechanical and geometric properties were fabricated. The average tensile modulus of the resulting ELAC threads ranged from 198 ± 90 to 758 ± 138 MPa. The average cross-sectional area ranged from 7756 ± 1000 to 1775 ± 457 μm2. The resultant mapping between IF parameters and ELAC thread properties enabled the production of strong and flexible threads with customizable properties.
Thermal Simulations of Cancerous Breast Tumors and Cysts on a Realistic Female Torso
Authors: González Francisco Javier 
Published: January 2021

Abstract
Medical thermography has been around for several decades however due to its low specificity it has not become a popular medical diagnostic technique. The development of computational models of heat transfer in biological tissue can provide a deeper knowledge of healthy and nonhealthy thermal patterns which could increase the specificity of this technique increasing its usefulness in clinical diagnosis. In this work, the thermal pattern of cancerous tumors and cysts are calculated through finite element computer simulations using a real human female torso. The simulation results show a thermal pattern that agrees with infrared thermal images taken from female subjects, the simulated thermal patterns show real thermal features that do not appear in simulations performed using other approximate geometries of the breast. Results show that the temperature on the region of the skin closest to the tumor decreases for cysts while it increases for malignant tumors. The temperature patterns show a 20% deviation from thermal simulations using a hemispherical model of the breast, these results reinforce the notion that the geometry used for thermal simulation plays an important role in the accuracy of the simulations. These results are a first step in understanding benign and malignant thermal processes of the breast which might help increase the usefulness of infrared imaging in breast clinical diagnosis.
A Computational Fluid Dynamics Investigation of Pneumatic Atomization, Aerosol Transport, and Deposition in Aerosol Jet Printing Process
Authors: Salary Roozbeh (Ross) , Lombardi Jack P. , Weerawarne Darshana L. , Rao Prahalada , Poliks Mark D. 
Published: January 2021

AbstractAerosol jet printing (AJP) is a direct-write additive manufacturing technique, which has emerged as a high-resolution method for the fabrication of a broad spectrum of electronic devices. Despite the advantages and critical applications of AJP in the printed-electronics industry, AJP process is intrinsically unstable, complex, and prone to unexpected gradual drifts, which adversely affect the morphology and consequently the functional performance of a printed electronic device. Therefore, in situ process monitoring and control in AJP is an inevitable need. In this respect, in addition to experimental characterization of the AJP process, physical models would be required to explain the underlying aerodynamic phenomena in AJP. The goal of this research work is to establish a physics-based computational platform for prediction of aerosol flow regimes and ultimately, physics-driven control of the AJP process. In pursuit of this goal, the objective is to forward a three-dimensional (3D) compressible, turbulent, multiphase computational fluid dynamics (CFD) model to investigate the aerodynamics behind: (i) aerosol generation, (ii) aerosol transport, and (iii) aerosol deposition on a moving free surface in the AJP process. The complex geometries of the deposition head as well as the pneumatic atomizer were modeled in the ansys-fluent environment, based on patented designs in addition to accurate measurements, obtained from 3D X-ray micro-computed tomography (μ-CT) imaging. The entire volume of the constructed geometries was subsequently meshed using a mixture of smooth and soft quadrilateral elements, with consideration of layers of inflation to obtain an accurate solution near the walls. A combined approach, based on the density-based and pressure-based Navier–Stokes formation, was adopted to obtain steady-state solutions and to bring the conservation imbalances below a specified linearization tolerance (i.e., 10−6). Turbulence was modeled using the realizable k-ε viscous model with scalable wall functions. A coupled two-phase flow model was, in addition, set up to track a large number of injected particles. The boundary conditions of the CFD model were defined based on experimental sensor data, recorded from the AJP control system. The accuracy of the model was validated using a factorial experiment, composed of AJ-deposition of a silver nanoparticle ink on a polyimide substrate. The outcomes of this study pave the way for the implementation of physics-driven in situ monitoring and control of AJP.
Integrated Remanufacturing and Opportunistic Maintenance Decision-Making for Leased Batch Production Lines
Authors: Xia Tangbin , Zhang Kaigan , Sun Bowen , Fang Xiaolei , Xi Lifeng 
Published: January 2021

Abstract
With the development of the product-service paradigm, many original equipment manufacturers (OEMs) have begun to provide remanufacturing services besides maintenance services as the lessors. An integrated contract including remanufacturing and maintenance service brings extra leasing profits and complex scheduling challenges as well. The use of machine remanufacturing in conjunction with system-level opportunistic maintenance (OM) has not been previously studied. This paper tries to integrate remanufacturing planning into maintenance optimizations for improved system performance in terms of saved leasing profits. An integrated remanufacturing and opportunistic maintenance (R&OM) policy is developed and applied to a leased manufacturing line in batch production. The system-level saved profit achieved via the R&OM policy is estimated and maximized through a sequential decision-making programming. Performing this integrated policy, it is possible to utilize the sequential R&OM opportunities raised from the random batch orders. In addition, preventive maintenance (PM) and preventive remanufacturing (PR) can be dynamically optimized to form profit-effective schemes. Numerical examples based on the collected information from a leased batch production line of engine crankshaft demonstrate that this proposed R&OM policy could efficiently achieve saved leasing profit maximization, reduce joint decision complexity, and expand OM theory.
Walking Speed Estimation From a Wearable Insole Pressure System Embedded With an Accelerometer Using Bayesian Neural Network
Authors: Wei Wang , Kaiming Yang , Yu Zhu , Yuyang Qian , Chenhui Wan , Min Li 
Published: January 2021

Abstract
In this study, we introduced a machine learning method for estimating human walking speed using plantar pressure and acceleration data. A pressure-derivative method using pretest feature selection was proposed to extract speed-related features from plantar pressure sensors. The maximum, minimum, and standard deviation of acceleration data were also selected as neural network inputs. To improve the generalization ability of the neural network, Bayesian regularization method was adopted. Experiments were conducted under seven different walking speeds to validate the performance of the proposed method. The results show that a strong linear correlation (R = 0.995) exists between the estimated and actual walking speed. The average error of the proposed method is 0.003 ± 0.043 m/s (mean ± root-mean-square error), which is better than previous works. It is suggested that including the speed-related information of both stance and swing phase would give a new insight for achieving a high accuracy of walking speed estimation.
A Comparative Analysis of Information Gathering Meetings Conducted by Novice Design Teams Across Multiple Design Project Stages
Authors: Loweth Robert P. , Daly Shanna R. , Hortop Amy , Strehl Elizabeth A. , Sienko Kathleen H. 
Published: January 2021

Abstract
Designers often gather information, for instance through stakeholder or domain expert meetings, to understand their design problems and develop effective solutions. However, few previous studies have provided in-depth descriptions of novice engineering designers’ approaches to conducting information gathering meetings. In this preliminary study, we analyzed data from six capstone mechanical engineering design teams to identify the types of individuals from whom teams gathered information, when these meetings occurred, and how teams solicited information during meetings. Teams in our study exhibited a range of information gathering behaviors that aligned with recommended practices, particularly in their early meetings. We also observed relatively few instances of teams exhibiting behaviors that were less similar to recommended practices during their meetings. However, our findings revealed two key trends across teams that represented specific opportunities for improvement and that may reflect characteristic novice approaches to conducting information gathering meetings. First, teams explored domain experts’ perspectives in depth during meetings and met with additional domain experts to inform their projects. Teams' meetings with project partners contained few instances of deep exploratory information gathering behaviors in comparison. In addition, teams seemed to finalize design decisions during early design meetings and were less likely to conduct information gathering meetings during later design phases. The comprehensive descriptions of novice mechanical engineering designers’ approaches provided in our preliminary study provide an entry point for further investigations that can inform engineering training, tools, and pedagogy for conducting effective meetings.
Design, Kinematics, and Application of Axially and Radially Expandable Modular Soft Pneumatic Actuators
Authors: Wang Nianfeng , Chen Bicheng , Ge XianDong , Zhang Xianmin , Chen Wei 
Published: January 2021

Abstract
Recently, soft pneumatic actuators (SPAs) have drawn increasing attention due to their ease of fabrication, high customizability, and intrinsic softness. Inspired by modular design, two kinds of SPAs, including an axial elongation soft pneumatic actuator (aeSPA) and a radial expansion soft pneumatic actuator (reSPA), are proposed in this paper, followed by their modeling, fabrication, and application in locomotion robots. The relationships between pressure and displacement of these SPAs are deduced based on the Yeoh model and the principle of virtual work, which has a good agreement with experimental results. Five modular worm-like crawling robots are fabricated by assembling the aeSPAs and reSPAs in different morphologies, and crawling tests are performed under different conditions to show the adaptivity of robots.
Connectivity Calculation-Based Automatic Synthesis of Planar Multi-Loop Mechanisms
Authors: Huang Peng , Ding Huafeng , Yang Wenjian , Xu Gongyue 
Published: January 2021

AbstractThe creative design of kinematic structures with excellent performance remains an open issue in the quest for developing novel multi-loop mechanisms. This study presents an automatic method to synthesize all nonisomorphic planar multi-loop mechanisms satisfying the required connectivity between the base and the end-effector. First, based on the connectivity matrix calculation, all multi-loop mechanisms are generated from synthesized kinematic chains. Second, the concepts of perimeter, canonical, and characteristic graphs of multi-color topological graphs are addressed to acquire the simplified characteristic hybrid code (SCHC) in order to eliminate isomorphic multi-loop mechanisms. Then, an automatic method to synthesize all nonisomorphic planar multi-loop mechanisms with the required connectivity between the base and the end-effector is provided. Finally, a practical application of this synthesis method is illustrated by taking the mechanical arm of a face-shovel hydraulic excavator as an example to demonstrate the effectiveness of the method.
Generic Implant Positioning Technology Based on Hole Projections in X-Ray Images
Authors: Windolf Markus , Richards Robert Geoff 
Published: January 2021

Abstract
Implant placement plays a key role in trauma and orthopedics. In this paper, a generic technological concept for implant positioning assistance is outlined. The system utilizes conventional radiographic devices for imaging and tracking and embeds into surgical workflows without the need for complex navigation equipment. It is based on feature extraction from cylindrical hole-projections in X-ray images for determining spatial alignment of implant and anatomy. Basic performance of a prototype system was experimentally verified in terms of tracking accuracy and robustness under varying conditions. In a second step, the system was developed into a set of application modules, each serving a pressing clinical need: Plating of the proximal humerus, cephalic nail and dynamic hip-screw placement, general anatomic plating, distal nail interlocking with adjustment of femoral anteversion and corrective osteotomies. Module prototypes were tested according to their degree of maturity from feasibility assessment in wet-labs to clinical handling tests. Orientation tracking of reference objects yielded an accuracy and precision of 0.1±0.71 deg (mean±standard deviation) with a maximum error of 4.68 deg at unfavorable conditions. This base-performance translated, e.g., into a precision of ±1.2 mm (standard deviation) screw-tip to joint distance at proximal humerus plating, or into a precision of lag screw positioning in the femoral head of ±0.6 mm in craniocaudal and ±1.6 mm in anterioposterior direction. The concept revealed strong potential to improve surgical outcomes in a broad range of orthopedic applications due to its generic and simplistic nature. Comprehensive validation activities must follow for clinical introduction.
Modeling and Model Validation of Thermal Behavior of Railway Disc During Single Braking
Authors: Zewang Yuan , Chun Tian , Mengling Wu , Jiajun Zhou , Chao Chen 
Published: January 2021

Abstract
The current thermal model of railway disc braking is rather coarse as the heat source is treated to be uniformly distributed. By using a Gaussian mixture function, the thermal behavior of railway disc braking was modeled. Simulations and full-scale rig tests of emergency braking about metro train at 40–100 km/h were conducted. The differences between the maximum temperatures calculated by the Gaussian mixture heat source method (GMHS method) and measurements are 2.56–4.71 °C. The relative errors between the maximum temperatures calculated by the GMHS method and thermal mechanical coupling method (TMC method) are no more than 2.53%. The temperature curves obtained by the GMHS method oscillate about their centerline with the same oscillating period to the TMC method. The time cost by the GMHS method is only 0.91–3.05% of the TMC method at the same conditions. The results indicate that the proposed GMHS method is accurate and efficient, which is more suitable for engineering application.
Neural Network Prediction of Boundary Layer Flashback
Authors: Leask Scott B. , McDonell Vincent G. , Samuelsen Scott 
Published: January 2021

Abstract
Flashback is a major concern for engine operation and safety, particularly with progress toward renewably producible and cleaner-burning fuels, such as hydrogen fuel blends. This work extends prior progress in developing models for predicting the onset of boundary layer flashback. While prior attempts have developed models based on analytical theory or through phenomenological considerations, problem complexity has inhibited flashback understanding and, hence, model performance. The goal of this work is to address current model performance limitations by leveraging the representational flexibility offered by neural networks (NNs) in predicting boundary layer flashback. This is demonstrated through two applications. The first demonstrates the utility of training an NN on only a subproblem, thereby preserving model intuition. The second presents a predictive boundary layer flashback model using only a NN. Focus is placed on developing NN models which are practical; the input and output variables are easily measurable and controllable prior to experimentation.
Experimental Investigation of a Small-Scale Organic Rankine Cycle Turbo-Generator Supported on Gas-Lubricated Bearings
Authors: Rosset Kévin , Pajot Olivier , Schiffmann Jürg 
Published: January 2021

Abstract
Waste heat recovery (WHR) is expected to contribute to reducing CO2 emissions from trucks. Organic Rankine cycle (ORC) systems show the highest potential for this application, but still lack efficient small-scale expansion devices, in practice. A novel turbogenerator (TG) supported on gas-lubricated bearings is presented in this paper. The device combines a single-stage radial-inflow turbine and a permanent-magnet machine in a single rotating part supported on aerodynamic bearings, lubricated with the working fluid (R245fa). The oil-free expander was tested within a dedicated ORC test setup. It was driven up to its nominal speed of 100 krpm, generated up to 2.3 kW of electrical power, and reached a peak overall efficiency of 67%. Although the prototype was not actively cooled, the mechanical losses of the rotor shaft and the iron loss of the electrical machine reached their nominal levels. Only the copper loss was at a part-load level. The electromechanical efficiency of the TG reached 91% and is expected to increase while testing the device at higher load. This proof of concept confirms the high-speed and low-loss potential of gas-lubricated bearings for small-scale dynamic expanders.