bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perspectives on utilization of macrophytes as feed ingredient for fish in future aquaculture
Authors: Naseem Shahida , Bhat Sami Ullah , Gani Adil , Bhat Farooz Ahmad 
Published: August 2020

AbstractAquaculture activity supplies high‐quality protein at affordable cost. A global call for foods of aquatic origin has heightened not only due to the zooming population growth, but also because of a choice of healthier foods for human beings. As the industry expands, it is facing the high cost of feeding because the key ingredients, that is fishmeal and fish oil, of aquadiet are very expensive. Identification of alternate foodstuffs that will remarkably minimize the expense of productivity of animal protein becomes a priority with due regard to environmental footprint. Alternative feed components are vital in partially or completely substituting unsustainable but high‐value components or constituents that will otherwise have direct competition with human use. Utilization of aquatic plants as a substitute for fish meal has the potential to revolutionize aquaculture in meeting global protein demand. A lot of money is spent on aquatic weed management, so this research idea tries to integrate both economic aspects and the environmental concerns. Macrophyte‐based feed ingredients have promising nutrient profile: crude protein ranges between 11% and 32%; lipid, 2.90% and 16.81%; and ash, 8% and 31%, a good array of amino acids; and a good amount of micro‐ and macronutrients that make them prosperous substituents for fish feed.
Fail‐safe aspects of oxygen supply
Authors: Duffin James 
Published: August 2020

Key points
A fall in oxygen supply releases a remedial response that is otherwise prevented when the oxygen supply is sufficient; for example, the remedial function of HIF‐1α is released when oxygen levels fall.
Concept: the physiological responses initiated when oxygen supply is compromised operate in a fail‐safe manner. This concept is applied to two cases: the control of cerebral blood flow, and the detection of hypoxia by the carotid body.
The fail‐safe oxygen supply concept was tested with simple computer simulations to demonstrate its function and verify the ability to reproduce measured data.
The computer model reproduced published observations, suggesting that the fail‐safe concept can be considered as a principle that provides novel insight into the physiology of oxygen supply in these cases.
AbstractAn engineered fail‐safe system automatically prevents or mitigates the consequences of a system failure. This operational concept can be applied both to the delivery of oxygen to the brain during hypoxia and anaemia, and to the carotid body response to hypoxia and hypercapnia. I aimed to develop simple mathematical models of these fail‐safe processes and examine their ability to replicate experimental observations. The intent is to demonstrate the validity of applying the fail‐safe concept, not to reveal the details of the physiology involved. The model calculations are based on a single compartment of the relevant tissue in each case that is challenged with a decrease in oxygen supply. The model equation parameters were adjusted to reproduce experimental observations. The fail‐safe model of cerebral blood flow control yielded results similar in form to published experimental observations of the cerebral blood flow responses to hypoxia and anaemia. The fail‐safe model of carotid body glomus cell control of intracellular hydrogen ion concentration also yielded results similar in form to observations of carotid sinus nerve responses to hypoxia and hypercapnia. The ability of these simple models to simulate experimental observations demonstrates the applicability of the fail‐safe concept to oxygen delivery. I suggest that a fail‐safe view of oxygen delivery provides novel physiological insight.
Apparent Flexoelectricity Due to Heterogeneous Piezoelectricity
Authors: Yvonnet J. , Chen X. , Sharma P. 
Published: August 2020

Abstract
Recent work has highlighted how the phenomenon of flexoelectricity can masquerade as piezoelectricity. This notion can not only be exploited to create artificial piezoelectric-like materials without using piezoelectric materials but may also explain measurement artifacts in dielectrics. In this article, we show that the reverse is also possible and potentially advantageous in certain situations (such as energy harvesting). By constructing a computational homogenization approach predicated on the finite element method, we argue that composites made of piezoelectric phases can conspire to endow the material with a distinct overall flexoelectric-like response even though the native flexoelectricity of the constituent materials is negligible. Full finite element procedures for numerical evaluation of the different effective tensors, including the flexoelectric tensor, are provided. Numerical investigations are conducted, showing variation of the effective flexoelectric properties with respect to local geometry and properties of the composite in piezoelectric–piezoelectric and polymer–piezoelectric composites. We find that the flexoelectric response can be tuned to nearly five times higher than the constituents.
Analysis of Flangeability by Single-Stage SPIF and Press-Working in AA7075-O Sheet
Authors: Borrego Marcos , Morales-Palma Domingo , Vallellano Carpóforo 
Published: August 2020

Abstract
Recently, the research interest of hole-flanging has turned from conventional press-working to single-point incremental forming (SPIF) as a viable process for small- and medium-sized batches. Both technologies have been studied separately using different approaches and, therefore, most studies cannot be easily compared. Besides, some studies that measured the formability in SPIF using the classical limiting forming ratio (LFR) showed conflicting results that still need to be clarified. Under these circumstances, the aim of this work is to provide a better understanding of the deformation process and the material formability in hole-flanging by critically comparing both forming processes. To this end, a series of experimental tests on AA7075-O sheet of 1.6-mm thickness by press-working and single-stage SPIF, using forming tools with different profile radii, are analyzed. The material formability and flange geometry are compared and discussed in detail. The process limits are analyzed by using both the Forming Limit Diagram (FLD) and the LFR. The failure modes by necking and fracture are clearly identified and assessed on both processes along with the influence of the bending induced by the tools during the flange forming. Results conclude that the LFR is not an adequate parameter to compare formability between processes other than press-working and, accordingly, two additional variables based on either the flange height or the average thickness reduction are proposed to successfully analyze flangeability.
Effect of Tip Clearance on the Aeroelastic Stability of a Wide-Chord Fan Rotor
Authors: Dong Xu , Zhang Yingjie , Zhang Ziqing , Lu Xingen , Zhang Yanfeng 
Published: August 2020

Abstract
This research presents a series of simulations that investigate the effects of tip clearance on the aeroelastic stability of a wide-chord high-speed transonic fan rotor. The results show that the stall margin and the total pressure ratio decreases as the tip clearance increases. The effect of tip clearance on the blade loading can extend to 30% span. The phase of the influence coefficient without tip clearance is different from that with clearance, which causes the most unstable aerodynamic damping to shift in the nodal diameter. As the clearance increases from 0.25 mm to 2 mm, the damping decreases. The nonmonotonic behavior found by other researchers was not observed in this study. We conclude that the tip clearance affects the aeroelastic stability in two ways. The first is to change the blade loading so that the amplitude of the unsteady pressure increases or decreases, while the phase hardly changes, resulting in changes in aerodynamic damping. The second is to change the local flow so that the unsteady pressure amplitude and the phase change locally.
On the Positioning of a Piezoelectric Material in the Energy Harvesting From a Nonideally Excited Portal Frame
Authors: Rocha Rodrigo T. , Tusset Angelo M. , Ribeiro Mauricio A. , Lenz Wagner B. , Haura Junior Remei , Jarzebowska Elzbieta , Balthazar Jose M. 
Published: August 2020

Abstract
In this paper, we consider the application of the piezoelectric energy harvesting using a portal frame structure of two-degrees-of-freedom. The piezoelectric material is considered as a linear device using a capacitive mathematical model. The portal structure is of two-degrees-of-freedom considering with quadratic coupling between the first and second modes of vibration. 2:1 internal resonance between the first and second modes is set, which is a particular condition of this type of system due to the appearance of a saturation phenomenon. As this phenomenon causes the system to start vibrating from the second mode and, at steady-state, vibrates at the first mode, the objective of this work is to verify the energy uptake, considering the different positioning of a piezoelectric material, which is coupled to the supported beam and/or to the column. In addition, the structure is excited by a nonideal DC motor with a limited power supply. The results show a considerably nonlinear behavior due to the nonideal motor, and, with the saturation phenomenon, it is more efficient to collect energy by coupling the PZT to the column. The investigation of the stability of the system due to the piezoelectric coefficient Θ is also taken into account, which is carried out by numerical tools as phase planes, Poincare maps, bifurcation diagrams, and 0–1 test.
Numerical Modeling of Vascular Stresses During Lead Extraction: Subclavian vs. Femoral
Authors: Toloui Mostafa , Marshall Mark , Vatterott Pierce , Zhang Peter , Lahm Ryan , Lulic Thomas , Harris Megan 
Published: August 2020

Abstract
Transvenous lead extraction is a critical and growing technique used to treat patients with chronically implanted pacemakers and defibrillators. This procedure is commonly executed via the subclavian vein or the femoral vein. Some physicians’ experiences indicate that the femoral approach results in fewer vascular tears. This study is aimed to present a physics-based comparative assessment of intravenous mechanical stresses for chronic lead management between the two approaches. Finite Element (FE) modeling is employed to quantify the vascular stress distributions. A full 3-D model including veins, heart, fibrotic scar regions and the lead was created to simulate the different lead extraction methods. Results: (1) highest stresses are generally in the vicinity of SVC lead attachments; (2) femoral approach results in a ∼uniform distribution of stress over the scar while the subclavian approach leads to patches of concentrated high stress; (3) 2–3 times higher maximum vascular stress during subclavian; (4) insignificant maximum stress at the apex for both; (5) inverse variation of stress levels with: (i) branch-to-scar distance for SVC method; and (ii)vein wall thickness in both methods. (6) lower stress levels for scars with longer attachment lengths. The importance and effectiveness of mechanical stress analysis in risk analysis for chronic lead management is illustrated. Overall, the localized intravascular wall stress is meaningfully higher for subclavian vs. femoral extraction with same SVC shear force. This may help explain the higher rate of SVC tears when extracting from the left subclavian approach. The individual anatomy (e.g. vascular angles) is a key factor in the resulting stress and this understanding may be critical when choosing an extraction approach and future lead design.
Stakeholder Engagement With Prototypes During Front-End Medical Device Design: Who Is Engaged With What Prototype?
Authors: Coulentianos Marianna J. , Rodriguez-Calero Ilka , Daly Shanna R. , Sienko Kathleen H. 
Published: August 2020

Abstract
Stakeholder engagement with prototypes during the front-end phases of medical device design can support problem identification, problem definition, and early concept generation. This study examined what prototypes were leveraged to engage specific types of stakeholders during front-end medical device design. Analysis of semi-structured interviews with 22 design practitioners in the medical device industry revealed some common associations of prototype choice for particular stakeholders. A few associations are highlighted: designers engaged users with physical three-dimensional (3D) prototypes, financial decision-makers with physical 3D and two-dimensional (2D) prototypes, government and regulatory stakeholders with 2D prototypes, and expert advisors with digital 3D prototypes. The rationale provided by practitioners revealed the intentional selection of prototype form for specific stakeholder engagements.
Magnetic Particle Spectroscopy-Based Handheld Device for Wash-Free, Easy-to-Use, and Solution-Phase Immunoassay Applications
Authors: Chugh Vinit Kumar , Wu Kai , Nair Abilash , di Girolamo Arturo , Schealler James , Vuong Hoang , Davies Will , Wall Adam , Whitely Emmet , Saha Renata , Su Diqing , Wang Jian-Ping 
Published: August 2020

Abstract
In recent years, magnetic particle spectroscopy (MPS) has emerged as a new technology for immunoassay applications. In MPS, alternating magnetic fields are applied to magnetic nanoparticles (MNPs). The magnetic responses of these nanoparticles are collected and recorded by a pair of specially designed pick-up coils. These magnetic responses contain higher harmonics that are specific to the physical changes of the nanoparticles such as the binding events of target analytes to nanoparticles. This volumetric-based bioassay method analyses the response signal from the whole nanoparticle suspension, thus, allows one step and wash-free immunoassay with minimum technical requirements. In this work, we developed a handheld MPS system as a future highly sensitive, cheap, in vitro, and easy-to-use point-of-care (POC) detection kit.
A System for the Objective Assessment of Hand Proprioceptive Function in Pediatric and Adult Populations
Authors: Oh Jinseok , Mahnan Arash , Xu Jiapeng , Holst-Wolf Jessica , Block Hannah , Konczak Jürgen 
Published: August 2020

Abstract
Proprioceptive signals from mechanoreceptors embedded in ligaments, tendons, and muscles are essential for the control of muscle tone and voluntary movement. Numerous neurological and orthopedic disorders are associated with proprioceptive dysfunction that impairs the control of balance and/or fine motor function. However, obtaining objective measures of proprioceptive function is difficult in most clinical settings, because available assessment methods rely on specialized equipment, expertise, or are too time-consuming. This paper presents a new tablet-based system that objectively measures finger position sense by implementing a psychophysical threshold search method. We here provide initial data that demonstrate the ease-of-use and efficacy of the system.
Effect of Coal Fouling on Railroad Ballast Under Direct Shear Loading Conditions
Authors: Dinesh Gundavaram , Hussaini Syed Khaja Karimullah 
Published: August 2020

Abstract
Contamination of ballast generally occurs due to particle breakage, infiltration of other undesired materials from the surface or base of the ballast is one of the primary reason for track deterioration. In this context, large scale direct shear tests were conducted to examine the shear behavior of unstabilized and geogrid-stabilized fresh and coal fouled ballast. Fresh granite ballast with an average particle size (D50) of 42 mm and triaxial geogrid having 69 × 69 mm aperture were used in this study. Tests were conducted at different Void Contamination Index (VCI) values ranging from 0 to 60% at a constant shearing rate (Sr) of 3 mm/min and normal stress (σn) of 90 kPa. The test results revealed that the shear strength of ballast is highly influenced by the coal fouling. The friction (φ) and dilation angles (ψ) of unstabilized ballast is found to decrease from 63.06° to 55.55° and 17.7° to 11.22°, respectively as the VCI increases from 0 to 60%. It is further observed that the breakage of ballast (Bg, computed in terms of Marsal’s breakage) decreases from 9.37 to 3.98% with the presence of coal fines. However, the presence of geogrid was found to increase the friction angle and reduce the particle breakage and dilation of fresh and coal fouled ballast. These test results show the effectiveness of triaxial geogrid in stabilizing the fresh and coal fouled ballast.
Wheel-Rail Interface Condition Estimation via Acoustic Sensors
Authors: Shrestha Sundar , Koirala Anand , Spiryagin Maksym , Wu Qing 
Published: August 2020

Abstract
The surface roughness between the wheel and rail has a huge influence on the rolling noise level. The presence of the third body such as frost or grease at the wheel-rail interface contributes towards change in adhesion coefficient resulting in the generation of acoustic noise at various levels. Therefore, it is possible to estimate adhesion conditions between the wheel and rail from the analysis of audio patterns originating from wheel-rail interaction. In this study, a new approach to estimate adhesion condition is proposed which takes rolling noise as input.
Acoustic sensors (Behringer B-5 condenser microphone) for audio data acquisition were installed on a scaled bogie test rig. The cardioid configuration of the sensor was chosen for picking up the source signal while avoiding the surround sound. The test rig was operated at the speed of 40 and 60 rpm multiple times in both dry and wet friction conditions. The proposition behind running the setup several times was to get a large set of acoustic signals under different adhesion conditions because there exists no such dataset in the public repositories. 30 seconds interval of rolling noise data from the continuous audio signal was extracted as samples for the training W-RICE model. Each sample was pre-processed using the Librosa python package to extract seven basic features/signatures: zero-crossing rate, spectral centroid, spectral bandwidth, spectral roll-off, MFCCs (Mel-frequency cepstral coefficients), RMS (root-mean-square) energy and Chroma frequencies. These features were used as input to an MLP (Multi-Layered Perceptron) neural network and trained for four different classes (dry and wet conditions with speed of 40 rpm and 60 rpm each). MLP model training and testing were implemented in Keras deep learning library. MLPs can automatically learn useful and meaningful relationships among the input features for classifying the input audio sample to one of the output classes/categories. For four output categories considered, 100% classification accuracy was achieved on the test set while accuracies of 99.56%, 73.24%, and 63.59% were achieved for three validation sets consisting of audio samples of varying noise levels.
Discrete Element Modeling of Railway Ballast for Studying Railroad Tamping Operation
Authors: Dama Nilesh , Ahmadian Mehdi 
Published: August 2020

Abstract
The dynamic behavior of ballast particles during track tamping is studied by developing a computer simulation model using the Discrete Element Model (DEM) method. The simulation model is developed in a commercially available DEM software called PFC3D (Particle Flow Code 3D). The study primarily evaluates a complete tamping cycle as defined by insertion, squeeze, hold, and withdrawal. Using a Taguchi approach, the effect of Tine motion’s frequency and amplitude, insertion velocity, and squeeze velocity are evaluated on tamping effectiveness. The compactness of the ballast particles, as defined by the average number of contacts per particle (referred to “Coordination Number”) is used as a measure of the effectiveness of tamping. Setting up the DEM model and important elements such as selection and calibration of particle shapes, ballast mechanical properties, contact model, and parameters governing the contact force models are described in detail. The tamping process is evaluated using a half-track layout with a highly modular code that enables a high degree of adjustability to allow control of all parameters for improved simulation flexibility. A parametric study is performed to find the best values of tine motion parameters for improving tamping efficiency. A performance comparison is made between linear and elliptical tamping. The results indicate that smaller squeeze and release velocities of the tines yield better compaction. Of course, reducing the velocities would result in increased tamping time. Additionally, the results indicate that the linear motion of the tines potentially result in better compaction than elliptical motion, although the latter may require less insertion force (power) and cause less ballast damage.
Estimating the Inner Ring Defect Size and Residual Service Life of Freight Railcar Bearings Using Vibration Signatures
Authors: Lima Jennifer , Tarawneh Constantine , Aguilera Jesse , Cuanang Jonas 
Published: August 2020

Abstract
There are currently two primary wayside detection systems for monitoring the health of freight railcar bearings in the railroad industry: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the train operator of high-risk defects. However, many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans about 90% of a bearing’s raceway, and there are less than 30 systems in operation throughout the United States and Canada. HBDs sit on the side of the rail-tracks and use non-contact infrared sensors to acquire temperatures of bearings as they roll over the detector. These wayside bearing detection systems are reactive in nature and often require emergency stops in order to replace the wheelset containing the identified defective bearing. Train stoppages are inefficient and can be very costly. Unnecessary train stoppages can be avoided if a proper maintenance schedule can be developed at the onset of a defect initiating within the bearing. Using a proactive approach, railcars with defective bearings could be allowed to remain in service operation safely until reaching scheduled maintenance.
The University Transportation Center for Railway Safety (UTCRS) research group at the University of Texas Rio Grande Valley (UTRGV) has been working on developing a proactive bearing condition monitoring system which can reliably detect the onset of bearing failure. Unlike wayside detection systems, the onboard condition monitoring system can continuously assess the railcar bearing health and can provide accurate temperature and vibration profiles to alert of defect initiation. This system has been validated through rigorous laboratory testing at UTRGV and field testing at the Transportation Technology Center, Inc. (TTCI) in Pueblo, CO. The work presented here builds on previously published work that demonstrates the use of the onboard condition monitoring system to identify defective bearings as well as the correlations developed for spall growth rates of defective bearing outer rings (cups). The system first uses the root-mean-square (RMS) value of the bearing’s acceleration to assess its health. Then, an analysis of the frequency domain of the acquired vibration signature determines if the bearing has a defective inner ring (cone) and the RMS value is used to estimate the defect size. This estimated size is then used to predict the residual life of the bearing. The methodology proposed in this paper can assist railroads and railcar owners in the development of a proactive and cost-efficient maintenance cycle for their rolling stock.