bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence of region‐specific right ventricular functional adaptation in endurance‐trained men in response to an acute volume infusion
Authors: Dawkins Tony G. , Curry Bryony A. , Drane Aimee L. , Lord Rachel N. , Richards Cory T. , Lodge Freya M. , Yousef Zaheer , Pugh Christopher J. A. , Shave Robert E. , Stembridge Mike 
Published: November 2021

New Findings
What is the central question of this study?
Endurance athletes demonstrate altered regional right ventricular (RV) wall mechanics, characterized by lower basal deformation, in comparison to non‐athletic control subjects at rest. We hypothesized that regional adaptations at the RV base reflect an enhanced functional reserve capacity in response to haemodynamic volume loading.
What is the main finding and its importance?
Free wall RV longitudinal strain is elevated in response to acute volume loading in both endurance athletes and control subjects. However, the RV basal segment longitudinal strain response to acute volume infusion is greater in endurance athletes. Our findings suggest that training‐induced cardiac remodelling might involve region‐specific adaptation in the RV functional response to volume manipulation.
AbstractEccentric remodelling of the right ventricle (RV) in response to increased blood volume and repetitive haemodynamic load during endurance exercise is well established. Structural remodelling is accompanied by decreased deformation at the base of the RV free wall, which might reflect an enhanced functional reserve capacity in response to haemodynamic perturbation. Therefore, in this study we examined the impact of acute blood volume expansion on RV wall mechanics in 16 young endurance‐trained men (aged 24 ± 3 years) and 13 non‐athletic male control subjects (aged 27 ± 5 years). Conventional echocardiographic parameters and the longitudinal strain and strain rate were quantified at the basal and apical levels of the RV free wall. Measurements were obtained at rest and after 7 ml/kg i.v. Gelofusine infusion, with and without a passive leg raise. After infusion, blood volume increased by 12 ± 4 and 14 ± 5% in endurance‐trained individuals versus control subjects, respectively (P = 0.264). Both endurance‐trained individuals (8 ± 10%) and control subjects (7 ± 9%) experienced an increase in free wall strain from baseline, which was also similar following leg raise (7 ± 10 and 6 ± 10%, respectively; P = 0.464). However, infusion evoked a greater increase in basal longitudinal strain in endurance‐trained versus control subjects (16 ± 14 vs. 6 ± 11%; P = 0.048), which persisted after leg raise (16 ± 18 vs. 3 ± 11%; P = 0.032). Apical longitudinal strain and RV free wall strain rates were not different between groups and remained unchanged after infusion across all segments. Endurance training results in a greater contribution of longitudinal myocardial deformation at the base of the RV in response to a haemodynamic volume challenge, which might reflect a greater region‐specific functional reserve capacity.
Degradation Mechanism of the Balsa Wood Core Composite Sandwich Beam From Heating From One Side
Authors: Dutta Piyush K. , Hui David , Argueso Marta 
Published: November 2021

Abstract
An experimental study of the behavior at different temperatures of Balsa Wood Core Composite Sandwich (BWCCS) panels proposed to be used in shipboard structures is presented. It characterizes the high temperature failure of the BWCCS under a flexural load. The study includes two different experiments. The first is the determination of temperature distribution along the thickness of BWCCS panels. In the second, the panels are studied in a three-point bending test at two different temperatures: room temperature (20°C) and high temperature (79°C).
The Role of Adhesive in the Load Response of Adhesively Bonded Aluminum Hat Sections Under Axial Compression
Authors: Lu Jianping , Newaz Golam M. , Gibson Ronald F. 
Published: November 2021

Abstract
Aluminum hat section, either adhesively bonded or unbonded, experiences buckling, post buckling and plastic collapse when axially compressed. However, there exist obvious differences in the load response between the bonded and unbonded hat sections. Finite element eigenvalue buckling analysis is carried out to predict the buckling load and mode. Experiments show that when adhesively bonded hat sections begin to buckle there is a transformation from the first buckling mode to the higher ones, while the unbonded hat sections develop the post buckling based on the lowest buckling mode. The different buckling modes result in not only different buckling loads but different peak loads of the hat sections as well. Finally, the ultimate compressive strength formulae are proposed for the hat sections.
Optimal Configuration of Ultrasonic Sensors in a 3D Position Estimation System Using Genetic Algorithms
Authors: Ray Probir Kumar , Unnikrishnan Nishant , Mahajan Ajay 
Published: November 2021

Abstract
This paper provides a genetic algorithm based approach to calculate the optimal placement of receivers in a 3D position estimation system that uses the difference in the time-of-arrivals (TOA) of an ultrasonic wave from a transmitter to the different receivers fixed in 3D space. This is a different approach to traditional systems that use the actual time-of-flights (TOF) from the transmitter to the different receivers and triangulate the position of the transmitter. The new approach makes the system more accurate, makes the transmitter independent of the receivers and does not require the need of calculating the time delay term that is inherent in traditional systems due to delays caused by the electronic circuitry. This paper presents a thorough analysis of receiver configurations in the 2D and 3D system that lead to singularities, i.e. locations of receivers that lead to formulations that can not be solved due to a shortage of information. It provides guidelines of where not to place receivers, and further, presents a detailed analysis of locations that are optimal, i.e. locations that lead to the most accurate estimation of the transmitter positions. The results presented in this paper are not only applicable to ultrasonic systems, but all systems that use wave theory, e.g. infrared, laser, etc. This work finds applications in virtual reality cells, robotics, guidance of indoor autonomous vehicles and vibration analysis.
Piezoelectric Structural Vibration Control Using Active Resonator Absorber
Authors: Knowles David W. , Jalili Nader , Ramadurai Sriram 
Published: November 2021

Abstract
A novel dynamic vibration absorber is presented while exploring its practical implementation using piezoelectric ceramic (PZT) inertial actuators. It is referred to as active resonator absorber (ARA). The ARA is a passive absorber with an additional dynamic feedback compensator within the PZT actuator. Without any controller, the PZT inertial actuator becomes a passive vibration absorber due to the internal damping and stiffness properties of piezoelectric materials. Hence, it is inherently fail-safe. For active operation, the compensator parameters are designed such that a resonance condition is intentionally created within the absorber to mimic the vibratory energy from the system of concern to which it is attached. The resonance condition can be created through the appropriate design of the compensator and implemented through adjusting the external electrical voltage applied to the absorber. Because the parameters of the PZT actuators (i.e. stiffness, damping, and effective mass) are estimates, compensator designs based on these parameters would result in partial vibration suppression, when utilized in real applications. An auto-tuning method is, therefore, introduced to effectively tune the compensator parameters to improve vibration suppression quality. The effectiveness and stability of the proposed absorber is demonstrated through simulations when appended on a SDOF primary system.
Acoustic Energy Extraction in the Presence of Duct Mean Flow
Authors: Madanshetty Sameer I. , Chu Boa-Teh 
Published: November 2021

Abstract
A method for controlling noise level in duct flows is described. The method is based on the principle of energy extraction by active source(s), rather than by wave cancellation as in “anti-sound”. As such the method of energy extraction is robust; it does not need the delicate signal processing, perfect phase and amplitude matching, crucial to sound cancellation. Analysis indicates that in the presence of through flow the control is effective in extracting energy from any waves traversing it. As the duct flow Mach number increases the control appears to be less effective for waves produced upstream of it but it is more effective for the waves produced downstream of the device. Further, this conclusion remains valid whether the detector is placed on the upstream or downstream side of the control device. A future paper will report the experimental validation of the analysis.
Active Noise Cancellation Using Feedforward and Hybrid Controls
Authors: Ohadi A. R. , Esmailzadeh E. , Alasty A. 
Published: November 2021

Abstract
The exact closed-form solution of a one-dimensional wave equation including the viscous damping effect has been obtained from the Green’s function. Accurate models for the error sensor and secondary loudspeaker, which includes the electro-mechanical and mechano-acoustical couplings, have been used and the transfer function of the primary, secondary and acoustic feedback paths of the active noise control system have been obtained. The generalized form of the classical FXLMS algorithm, referred to G-FXLMS algorithm, has been developed. In contrast to the FXLMS algorithm, G-FXLMS algorithm does not neglect the time shift of the filter coefficients and employs a more general recursive adaptive weight update equation, which can improve the performance of FXLMS algorithm. Simulation results presented to compare the performance of the feedforward and hybrid ANC systems and to study the effect of acoustical feedbacks and boundary conditions on the overall performance of ANC systems.
On the Design of Adaptive Robust Repetitive Controllers
Authors: Yao Bin , Xu Li 
Published: November 2021

Abstract
A new perspective on dealing with the noise sensitive problem of repetitive control algorithms is given in the paper. It is firstly shown that, in continuous-time domain, what the conventional repetitive learning algorithm does is equivalent to adapting all the values of the periodic uncertainties over one period. Such an endeavor means very high bandwidth of the learning algorithm as an infinite number of parameters need to be adapted, which puts a great demand on microprocessor memory in implementing the algorithms. At the same time, such a formulation also makes the algorithm very sensitive to noise as it treats the values of the periodic uncertainties over the same period totally independent from each other, just like a random noise. Based on this new perspective on the noise sensitive problem of repetitive algorithm, a simple remedy is provided for the recently proposed adaptive robust repetitive control (ARRC) design by recognizing the physical dependence of the values of the periodic uncertainties over the same period and using certain known basis functions to capture these physical dependence. By doing so, only the amplitudes of these known basis functions need to be adapted on-line. The net results are that, not only the number of the parameters to be adapted is reduced drastically, but also the noise sensitive problem of the conventional learning algorithm is overcome. The precision motion control of a linear motor drive system is used as an application example. The comparative experimental results demonstrate that, with the new adaptive robust repetitive control design, not only the noise sensitive problem of repetitive learning is completely eliminated, but also a much improved tracking performance is achieved due to the built-in extrapolation capability of the basis functions used.
Fuzzy Modeling on the Basis of FCM Technique: A Case Study Aiming at Process Supervision
Authors: Guerra Rodolfo E. Haber , Haber Rodolfo Haber , Alique Angel , Peres Clodeinir R. , Ros Salvador 
Published: November 2021

Abstract
The nonlinear behavior and complexity of machining processes have motivated researchers to use fuzzy model to effect process supervision. The main idea of this paper concerns the application of fuzzy logic and clustering techniques to develop a fuzzy model of the milling process aiming at the optimization of machine-tool performance and the overall machining process. A brief description of the algorithm employed is given, focused on the fuzzy c-mean technique (FCM). The results indicate that the FCM criterion is suitable for modeling complex processes such as the milling process. The fuzzy model obtained serves as foundation to develop complex supervisory systems.
Intelligent Modeling of Complex Manufacturing Processes Using Hierarchical Fuzzy Basis Function Networks
Authors: Lee Cheol W. , Choi Taejoon , Shin Yung C. 
Published: November 2021

Abstract
This paper presents a generalized modeling approach to modeling of complex manufacturing processes. Fuzzy basis function networks with a novel training algorithm are used to capture the cause-effect relationships of complex manufacturing processes. The modeling scheme allows for utilization of the existing knowledge in the form of analytical models, experimental data and heuristic rules in developing a suitable model. The method is implemented for the surface grinding processes based on the hierarchical structure of fuzzy basis function networks proposed by Lee and Shin [21]. Process models for surface roughness and residual stress are developed based on the available grinding model structures with a small number of experimental data to demonstrate the concept. The accuracy of developed models is validated through independent sets of grinding experiments.
Robust Output Feedback Force Control of Cantilever Beam Using Piezoelectric Actuator
Authors: Yim Woosoon , Singh Sahjendra N. 
Published: November 2021

Abstract
This paper treats the question of force control and stabilization of a flexible beam using a piezoceramic actuator using only output feedback. It is assumed that there exists unstructured model uncertainties including beam parameters, contact surface stiffness, and the number of vibration modes in the model, and only force measurement is used for the contact force control. The controller has the structure of an inverse (a feedback linearizing) control system. For compensating the unknown function in the inverse control law arising from the uncertainties in the model, its estimate is constructed by a high-gain observer. Simulation results are presented which show robust force trajectory control and stabilization in the closed-loop system in the presence of unstructured uncertainties.
Design and Integration of a Torque Sensor Beam Based Masterarm
Authors: Lee Sooyong , Kim Yoon Sang , Cho Changhyun , Kim Munsang 
Published: November 2021

Abstract
A new concept of the exoskeleton-type masterarm, composed of serial links, is introduced in this paper. To provide maximum range of human motion, several redundant joints are added to the serial links. In order to reduce the number of joints to be measured, kinematics of serial links was taken into consideration in design. Three measurable, controllable joints and three redundant free joints are used for the upper arm (shoulder), similarly to the forearm (wrist) while one measurable, controllable joint is used for the elbow. In particular, a torque sensor beam is designed for fine force reflection using the strain gauge. It detects the torque as well as its direction applied by the human operator, which allows the electric brake to be used as an actuator for force reflection. The electric brake constrains the joint movement so that the operator can feel the force. This electric brake outperforms the motor in terms of torque/weight ratio and makes the device light and compact. This masterarm measures the movement of the operator’s arm precisely, and it can be used for teleoperation with a slave robot, or as a motion planner for an industrial robot.
Robot Control Based on Coriolis and Centrifugal Terms Fuzzification
Authors: Politis Panos N. , Moulianitis Vassilis C. , Aspragathos Nikos A. 
Published: November 2021

Abstract
A new method for on-line tuning the gains of a decentralized PD controller with gravity compensation using fuzzy logic is proposed. The design of the controller is based on the fuzzy description of the robot configuration. The fuzzy inference system keeps track and takes decisions based on the robot configuration and joint velocities to adjust the derivative and proportional gains. The rules governing the controller are derived by studying the effects of the Coriolis and centrifugal terms on the robot dynamic behavior. The gravitational terms are computed using a fuzzy inference system for each joint. This FIS is trained with data taken from the simulated robot. The designed fuzzy-PD controller is compared with a centralized PD control law with gravity compensation and it is found that the fuzzy-PD controller is more robust in facing dynamic uncertainties. A two DOF robotic arm is used to demonstrate the performance of the proposed method for designing a robot controller.
A Mixed Thermal Convection Criteria for a Printed Circuit Board
Authors: Kehoe E. , Grimes R. , Davies M. 
Published: November 2021

Abstract
Mixed convection is a fundamentally significant heat transfer problem that occurs in a wide range of industrial and technological applications. For example, it is of great interest to thermal designers in the field of electronic cooling. Given that its occurrence is frequent, there is a necessity to understand its physics. This investigation is focused on a horizontal cylinder in cross-flow, at low Reynolds numbers of order 100–102 and high Grashof numbers of order 104 and at the Prandtl number for air. Particle image velocimetry and interferometric measurements for these cases clearly show the range of Gr/Re2 for which mixed convection occurs. Infra red temperature measurements from a printed circuit board mounted in a test electronic system at similar values of Grashof and Reynolds number are then presented which exhibit similar mixed convection phenomena.
The novelty lies in using the detailed measurements from the cylinder experiments to explain the temperature distribution across the printed circuit board. To do this requires finding the correct and characteristic lengths in the similarity condition. This should therefore allow the designers of electronic systems to estimate the values of Reynolds and Grashof number for which buoyancy effects need to be considered. This in turn will enable the designer to better predict the circuit board temperature distribution and component reliability.
An Investigation of Wavy Flow Passages on the Performance of Oil-Water Separators
Authors: Langerman Michael A. , Jensen Chenoa J. 
Published: November 2021

Abstract
The purpose of this research is to analyze flow fields within channels bounded by wavy plates and assess the effects of these flow passages on the efficiency of oil-water separators. Results from this study are used to analytically assess an industry accepted result that wavy plate channel surfaces promote a more effective oil-water separation process. For this investigation, an uncoupled, two-dimensional, dispersed-phase, simulation is implemented using a commercially available computational fluid dynamics code. First, the continuous phase (water) velocity field is calculated. For comparison purposes, both fiat and wavy passages are simulated. Next, buoyant oil particles (specific gravity of 0.70 and 0.95) are superimposed as the dispersed phase at the inlet to the channel. Oil droplet diameters of 100, 200, and 300 μm, which are typical droplet diameters encountered in industrial applications, are simulated. The particle trajectories are then determined and observations made of the particle behavior near the channel walls for both channel geometries.
Results show that a percentage of the particles are captured in vortices generated in the fluid within the wavy plate corrugations. As more particles are captured within these vortices, the spatial density of oil particles increases thus promoting coalescence. The coalescence results in larger oil particle diameters that, in turn, enhance separation through increased buoyancy. These results appear to substantiate industry observations regarding an increased oil-water separation efficiency using wavy channel passages. Nevertheless, more research is needed to optimize the design of the passages and better understand the coalescence phenomena.
Large Eddy Simulation and Experimental Measurements of a Methane-Air Fire Plume
Authors: DesJardin P. E. , Tieszen S. R. , O’Hern T. J. 
Published: November 2021

Abstract
Measurements of a large, 1-m in diameter, turbulent buoyant methane-air fire plume are taken and compared to results from numerical simulation using Large Eddy Simulation (LES). The experiments are carried out in Sandia’s FLAME (Fire Laboratory for Accreditation of Models and Experiments) facility and consist of a low velocity (0.12 m/sec) methane plume emitting upwards into ambient air. Numerical results show evidence of strong entrainment velocities resulting in flame pinch off near the base of the plume. Preliminary comparisons of the LES results to experimental measurements show good qualitative agreement to mean stream-wise and cross-stream velocities.
Heat Flux From Process Burners
Authors: Hayes Robert , Singh Prem , Baukal Charles E. , Foote Darin 
Published: November 2021

Abstract
This paper shows the effects of firing rate, excess air, and fuel composition on the heat flux profile from process burners as measured in large pilot-scale test furnaces. Firing rate and excess air had a significant effect on the heat flux profiles while the fuel gas blends studied here had a negligible impact.
Exact Closure Procedures of Hierarchical VAT Capillary Thermo-Convective Problem for Turbulent and Laminar Regimes
Authors: Travkin V. S. , Hu K. , Catton I. 
Published: November 2021

Abstract
Volume Averaging Theory (VAT), an effective and rigorous approach for study of transport (laminar and turbulent) phenomena, is used to model flow and heat transfer in porous media. The modeling is based on a simple pore level network. The primary difficulties in applying VAT to straight capillary networks, the many unknown integral and differential terms that are needed for closure, are overcome. VAT based modeling of pore level transport in straight capillaries results in two sets of scale governing equations. One scale is the upper scale VAT equations which describe ensemble properties for flow and heat transfer in porous media. The other scale is the lower scale laminar and turbulent transport equations that represent flow and heat transport in each straight pore capillary. It is how the unknown VAT terms in the upper scale equations can be estimated using the relationships between upper scale properties and lower scale properties. Exact closures and mathematical procedures are developed for the turbulent regime, extending the previous laminar regime work. Numerical results for turbulent and laminar transport in straight capillary porous media are shown in this paper.