bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pipeline Model Fidelity for Wave Energy System Models
Authors: Simmons Jeremy W. , Van de Ven James D. 
Published: December 2021

Abstract
Ocean wave energy conversion plants that use hydraulic power take-offs (PTOs) have been configured so that the working fluid must travel a significant distance (of several hundred to a few thousand meters) from the wave energy converter (WEC) located offshore to equipment onshore. With the pulsatile flow generated by the WEC having a peak period in the range of 3 to 12 seconds, the wavelengths of the excited pressure waves approach the length of the pipelines themselves. By the standards for modeling pipelines presented in popular fluid power and related textbooks, the system models for these plants should include distributed parameter models of the pipeline dynamics that capture the pressure wave delay effects. This work tests the importance of pipeline model fidelity for wave energy conversion plants. Simulations have been conducted of a simple but representative hydraulic PTO for wave energy conversion and incorporate several common lumped and distributed parameter pipeline models for comparison. These results are used to show the degree to which model fidelity effects several design metrics that are especially useful in the preliminary design phase of system development. The pipeline models used include: 1) a short line model that includes lumped resistive effects only, 2) a medium line model that also includes lumped inertial and capacitive effects for a single pipeline segment, 3) a long line model that uses repeated, lumped parameter line segments to approximate the distributed parameters of a real pipeline, 4) a simple method of characteristics solution to the one-dimensional momentum and continuity equations assuming a fixed wave speed, and 5) a discrete free-gas cavity model augmenting the simple method of characteristic pipeline model. The results suggest a relaxed standard for modeling pipelines in the case of this type of system, in which case, the recommended model is easily implemented in variable time step solvers and CAD software such as Simscape Fluids and can be used within the WEC-Sim modeling framework developed by the National Renewable Energy Lab.
Experimental Validation of Subsystem Models for a Novel Variable Displacement Hydraulic Motor
Authors: Larson Jacob , Pozo-Palacios Jonatan , Boyce-Erickson Grey , Fulbright Nathaniel , Dai Jaichen , Voth John , Gajghate Ninaad , Saikia Jordan , Michael Paul , Chase Thomas , Van de Ven James 
Published: December 2021

Abstract
A novel, variable displacement, low-speed high-torque hydraulic motor is being developed that is expected to be highly efficient across a broad operating range. To ensure the final hardware achieves the expected performance, the models used in the development of the motor must be experimentally validated and revised. The focus of this work is on mechanical energy loss models that were used to guide the design of a single-cylinder motor prototype and then experimental tests used for validation.
Losses were modeled and organized into five primary groups: main shaft bearings, main shaft seal, case windage, valve actuation, and linkage losses. The single-cylinder prototype was fabricated, and test parameters were defined. Two test rigs were designed and built to capture losses of the motor experimentally; one was used to collect low torque, zero/low-pressure differential results, and the other used to collect high torque, high-pressure differential results. A staged assembly procedure was developed to capture the independent contributions of each loss.
By reviewing the quality of correlation between test observations and model predictions and revising the model when necessary, the models were validated. The correlation was improved by reviewing and modifying model inputs. This allows future solutions to be more accurately predicted in the design phase to drive the design of better machines. The validated model package was able to predict the motor performance within an acceptable range of error.
AI-Based Condition Monitoring of Hydraulic Valves in Zonal Hydraulics Using Simulated Electric Motor Signals
Authors: Abdul Azeez Abid , Han Xu , Zakharov Viacheslav , Minav Tatiana 
Published: December 2021

Abstract
Zonal hydraulics, in particular Direct Driven Hydraulics (DDH), is an emerging transmission and actuation technique that is proposed to be used for electrification of heavy-duty mobile machinery. In addition to the already demonstrated advantages of DDH, which include high efficiency, compactness, and ease of maintenance, it is also capable of condition monitoring. The condition monitoring features can be obtained through indirect analysis of the existing electric motor signals (voltage and current) using artificial intelligence-based algorithms rather than by adding extra sensors, which are normally required for conventional realization. In this paper, the valve condition monitoring method of the DDH through electrical motor signals is explored at an early development stage. Firstly, the hydraulic valve models, which involve the valve fault behaviors, are added to the basic DDH model. Secondly, healthy and faulty scenarios for the valves are simulated, and the data are generated. Thirdly, the preliminary artificial intelligence-based condition monitoring classifier is developed using the simulation data, including feature extraction, algorithm training, testing, and comparison of accuracy. The effects of modeling error on developing the condition monitoring function are analyzed. In conclusion, the preliminary outcomes for the valve condition monitoring of the DDH are achieved by taking advantage of modeling and simulation and by utilizing the existing electric motor signals.
Comparative Analysis of Actuator Dimensioning Methods in Pneumatics
Authors: Boyko Vladimir , Hülsmann Steffen , Weber Jürgen 
Published: December 2021

Abstract
In the modern automation technology, there are often two ways to complete a drive task: pneumatically or electrically. In order to remain competitive with the electromechanics and to contribute to the achievement of climate protection goals, manufacturers and users of pneumatic systems are required to increase the energy efficiency of pneumatics. One of the primal and simplest methods to reduce the energy consumption of existing and to-be-developed pneumatic systems is the correct sizing of actuators. However, even in the most modern machines drives are often overdimensioned thus creating a higher energy consumption than necessary.
To counteract this, different dimensioning methods have been developed in the last few years, which could contribute to a significant reduction of energy consumption. Design tools based on dynamic simulations are highly reliable, but their calculation methods can be complex and non-transparent. Therefore, more pragmatic and simple dimensioning methods have been developed, based on algebraic approaches like force equilibrium, exergy equilibrium and pneumatic frequency ratio. In this paper these methods are evaluated using mathematical analysis and practical drive examples. Their possible application fields and limitations are shown and compared.
Dynamic Modeling and Design of a Radial Hydrostatic Piston Pump for Integrated Pump-Motor
Authors: Nahin Md Minal , Bohach Garrett R. , Nishanth F. N. U. , Severson Eric L. , Van de Ven James D. 
Published: December 2021

Abstract
There is a current trend towards the electrification of high force/torque density machines that have traditionally been dominated by diesel engine driven hydraulics. Power dense electric machines tend to favor high operating speeds whereas a hydraulic pump is more efficient at low speed and high torque conditions. The power density of a pump can be increased by decreasing the displacement and increasing the operating speed to provide the flow demand. This miniaturization of the pump allows it to be directly integrated into an electric motor inside a single casing. This integrated pump-motor is free of shaft seals and eliminates a set of bearings otherwise required when coupling an electric motor and pump with a shaft. Additionally, the leakage from the hydraulic pump can be used as coolant for the electrical machine, thereby improving the power density. In this paper, a hydrostatic radial piston pump has been evaluated for integration with an axial flux PM machine. The proposed hydrostatic piston pump uses a spherical head piston that can tilt while reciprocating inside the cylinder, eliminating the need for a joint at the slipper. To reduce the frictional loss between the slipper pad and the cam at high operating speeds, the cam freely rotates. A detailed model of the pump, with focus on the hydrostatic piston slipper, has been developed and a grid search approach has been utilized to select the critical parameters of the pump. Finally, an efficiency map has been presented for this pump at different operating conditions which shows around 86% efficiency at the 12500 rpm speed for 7 MPa pressure differentials.
Double-Input Multi-Output Pressure Control System Based on Addressable Pressure Component
Authors: Wei Qiandiao , Xu He , Chen Siqing , Fan Weiwang 
Published: December 2021

Abstract
Soft robots driven by pressurized fluid have recently been attracted more attention and achieved a variety of innovative applications in bionics, medical surgery, rehabilitation, search, and rescue system. And they have been demonstrated to be able to perform many different tasks, especially in some conditions of demand a high degree of compliance. Generally, they consisted of multiple actuate channels that require independent works. Consequently, a mass of pressure regulators and input pipelines are demanded, which will increase the complexity of the control system. To solve this problem, we propose a new pressure control method inspired by the control bus of electronic interface technology in this paper. An addressable pressure control bus system based on band-pass valve (BPV) and square wave of pressure (control signal) was designed. It consisted of a pressure supply source and an addressing signal, they are controled by two regulators, respectively. One of the pressure pipelines serves as the control bus to transmit the control pressure signal, which plays an addressing signal role in the system. The other serves as the pressure supply source of the multi-channel actuators. The BPV can be set to different opening pressure bands to realize the setting of diverse outputs address codes on the bus. This method discovered the work mode of double-input multi-output, which will get rids of the traditional control method of single-input single-output. In this paper, we designed the BPV and tested its function. To demonstrate the feasibility of this method proposed, a control system with two output ports was established. The result has shown that the output port can be selected by the pressure square wave signal, which realizes the function of single input multiple outputs. It reduces the complexity of the control strategy of the fluid control system.
Nonlinear Cutterhead Pose Control of Large-Diameter Slurry Shields in Complicated Stratum
Authors: Zhang Hangjun , Wei Jianhua , Fang Jinhui , Yang Yuzhu 
Published: December 2021

Abstract
To replace cutterhead worn tools conveniently or get rid of shield’s jamming effectively in complicated stratum, a new nonlinear cutterhead pose control system of large-diameter slurry shields is especially designed. High precision cutterhead pose control of large-diameter slurry shields is hardly achieved due to the uncertain load force and mass. A nonlinear controller constructed by adaptive robust control based on sliding mode is designed for this parallel mechanism, which includes a special adaptation law to compensate for the uncertainties. The stability of the whole closed loop system is verified based on Lyapunov theory. And the validity of the proposed strategy is proved by Simulink and AMESim co-simulation. The simulation results show that not only in control accuracy but also in parameter uncertainty, the designed nonlinear cutterhead pose control is effective.
A Simulation Survey on the Effects of Progressing Faults Within the SCAS of a Flight Control Actuator for Helicopters
Authors: De Martin Andrea , Jacazio Giovanni , Sorli Massimo , Vitrani Giuseppe 
Published: December 2021

Abstract
Stability Control Augmentation Systems (SCAS) are widely adopted to enhance the flight stability of rotary-wing aircraft operating in difficult aerodynamic conditions, such as low altitude missions, stationary flight nearby vertical walls or in presence of heavy gusts. Such systems are based upon small electro-hydraulic servosystems controlled in position through a dedicated servovalve. The SCAS operates with limited authority over the main control linkage translating the pilot input in the movement of the main flight control actuator. Being critical for the operability of the helicopter, the definition of a Prognostics and Health Management (PHM) framework for the SCAS systems would provide significant advantages, such as better risk mitigation, improved availability, and a reduction in the occurrences of unpredicted failures which still represent one of the most known downsides of helicopters. This paper provides the results of a preliminary analysis on the effects of the inception and progression of several degradation types within a simulated SCAS system. Signals usually available within such devices are hence combined with measurements provided by additional sensors to check the feasibility of a PHM system with and without dedicated sensors. The resulting features selection process shows that although the dedicated measurements are required to design a complete PHM system, it appears nonetheless possible to obtain valuable information on the health status of the SCAS system without resorting to additional sensors.
Hydraulic Test Stand to Model Circulatory System Dynamics for Artificial Heart Evaluation
Authors: Howard Joseph T. , Thomas Seth , Gallentine James C. , Barth Eric J. 
Published: December 2021

Abstract
This work proposes the theory and design of an experimental setup to mimic the dynamic impedance of the human circulatory system for testing the dynamic characteristics of an artificial heart. This platform has the same resistance, compliance, and inertance elements as the well-studied 4-element Windkessel model. As opposed to a circuit analogy model commonly seen in the literature, our platform remains within the same energy domain as the circulatory system. This allows an artificial heart designer to test pump performance and dynamic pressure characteristics under realistic loading. A test platform is designed using a non-hazardous working fluid with the same density and viscosity as blood. The system uses as few custom components as possible and interchangeable parts allow for system tuning.
Biomarker testing strategies in non-small cell lung cancer in the real-world setting: analysis of methods in the Prospective Central Lung Cancer Biomarker Registry (LungPath) from the Spanish Society of Pathology (SEAP)
Authors: Martín-López Javier , Rojo Federico , Martínez-Pozo Antonio , Hernández-Iglesias Teresa , Carcedo David , de Alda Lucía Ruiz , García J Francisco , Salas Clara 
Published: December 2021

AimsThe aim of this study is to extend the analysis of the Lung Cancer Biomarker Testing Registry (LungPath), by analysing the techniques used in the determination of epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1) and programmed death ligand-1 (PD-L1) for the diagnostic of patients with advanced non-small-cell lung cancer (NSCLC).MethodsInformation of the technique used for the determination of EGFR, ALK, ROS1 and PD-L1 was recorded from March 2018 to January 2019 from 44 centres, but only 34 centres matched with the 38 centres previously analysed, allowing to analyse the techniques used in 8970 matched determinations of EGFR, ALK, ROS1 and PD-L1. Therefore, a by-centre analysis studied the level of implementation of the techniques in the 44 centres, while a by-determination analysis made it possible to assess the overall frequency of the techniques used on the 9134 matched samples.ResultsBy-centre analysis showed that only 46.5% and 25.6% of the centres used reflex strategies for ALK and ROS1 determination, respectively. By-determination analysis showed that 94.4% of EGFR determinations were performed by PCR, 80.7% of ALK determinations were performed by IHC with clone D5F3, while 55.7% of ROS1 determinations were performed by IHC with clone D4D6. 22C3 were the PD-L1 clone more used (43.5%) followed by SP263 clone (31.1%).ConclusionsThe real-world evidence obtained from LungPath shows the effort of Spanish hospitals in performing biomarker determination in NSCLC with different methodologies despite that next-generation sequencing (NGS) utilisation in the year of the analysis was low. Biomarker determination results could be optimised with the incorporation of sequencing methods such as NGS in pathology departments.
Improving the clinical interpretation of missense variants in X linked genes using structural analysis
Authors: Sallah Shalaw Rassul , Ellingford Jamie M , Sergouniotis Panagiotis I , Ramsden Simon C , Lench Nicholas , Lovell Simon C , Black Graeme C 
Published: December 2021

BackgroundImproving the clinical interpretation of missense variants can increase the diagnostic yield of genomic testing and lead to personalised management strategies. Currently, due to the imprecision of bioinformatic tools that aim to predict variant pathogenicity, their role in clinical guidelines remains limited. There is a clear need for more accurate prediction algorithms and this study aims to improve performance by harnessing structural biology insights. The focus of this work is missense variants in a subset of genes associated with X linked disorders.MethodsWe have developed aprotein-specific variant interpreter(ProSper) that combines genetic and protein structural data. This algorithm predicts missense variant pathogenicity by applying machine learning approaches to the sequence and structural characteristics of variants.ResultsProSper outperformed seven previously described tools, including meta-predictors, in correctly evaluating whether or not variants are pathogenic; this was the case for 11 of the 21 genes associated with X linked disorders that met the inclusion criteria for this study. We also determined gene-specific pathogenicity thresholds that improved the performance of VEST4, REVEL and ClinPred, the three best-performing tools out of the seven that were evaluated; this was the case in 11, 11 and 12 different genes, respectively.ConclusionProSper can form the basis of a molecule-specific prediction tool that can be implemented into diagnostic strategies. It can allow the accurate prioritisation of missense variants associated with X linked disorders, aiding precise and timely diagnosis. In addition, we demonstrate that gene-specific pathogenicity thresholds for a range of missense prioritisation tools can lead to an increase in prediction accuracy.
Investigation on the performance dependence of proton radiated SiGe HBTs with emitter area and temperature
Authors: Wei Yinlong , Lan Kuibo , Wang Zhi , Wei Junqing , Ma Zhenqiang , Qin Guoxuan 
Published: December 2021

The DC and AC performances of proton radiated Silicon-Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) with different emitter areas at liquid nitrogen temperature (77 K), room temperature and heating hotplate (393 K) were presented in this work. Performance dependence on the emitter area and temperature was investigated. Results showed that SiGe HBTs with a large emitter area had more damage by proton radiation. Furthermore, the SiGe HBTs showed better tolerance to proton radiation at extreme temperatures than at room temperature. To reveal the underlying mechanism, the radiated SiGe HBTs were modeled based on the device structure and parameters. The electron density, Shockley–Read–Hall (SRH) recombination and carrier mobility were extracted from the device model and demonstrated to have major impacts on the performance dependence of the radiated SiGe HBTs. The results provide useful guidance for the application of SiGe HBTs at extreme environments.
Folded Electronic Textiles: Weaving, Knitting, Pleating and Coating Three-Dimensional Sensor Structures
Authors: Greinke Berit , Wood Emma , Skach Sophie , Vilas Arantza , Vierne Pauline 
Published: December 2021

AbstractThis article reports findings from a one-month design research project in which four textile and fashion designers engaged in collaborative exploration of technical and artistic knowledge inherent in folds and folding. They experimented with textile technologies and construction methods to design, fabricate and analyze three-dimensional dynamic materiality in electronic textiles (e-textiles). The focus was on sensor structures achieved by knitting, weaving, pleating and coating techniques. The analysis of measurements of electrical resistance between one and 36 sensing areas per sample demonstrate the added value of folds integrated into textile sensor structures. The authors discuss types of folding and their aesthetic, textural and sensorial advantages. Detailed information on design, fabrication and experimental results is provided in supplemental materials to the article.
Rapid spin up and spin down of flow along slopes
Authors: Peterson Henry G. , Callies Jörn 
Published: December 2021

Abstract
The near-bottom mixing that allows abyssal waters to upwell tilts isopycnals and spins up flow over the flanks of mid-ocean ridges. Meso- and large-scale currents along sloping topography are subjected to a delicate balance of Ekman arrest and spin down. These two seemingly disparate oceanographic phenomena share a common theory, which is based on a one-dimensional model of rotating, stratified flow over a sloping, insulated boundary. This commonly used model, however, lacks rapid adjustment of interior flows, limiting its ability to capture the full physics of spin up and spin down of along-slope flow. Motivated by two-dimensional dynamics, the present work extends the one-dimensional model by constraining the vertically integrated cross-slope transport and allowing for a barotropic cross-slope pressure gradient. This produces a closed secondary circulation by forcing Ekman transport in the bottom boundary layer to return in the interior. The extended model can thus capture Ekman spin up and spin down physics: the interior return flow is turned by the Coriolis acceleration, leading to rapid rather than slow diffusive adjustment of the along-slope flow. This transport-constrained one-dimensional model accurately describes twodimensional mixing-generated spin up over an idealized ridge and provides a unified framework for understanding the relative importance of Ekman arrest and spin down of flow along a slope.