bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancing Fractional Flow Reserve Procedure in Stenosis Diagnosis
Authors: Abuouf Yasser , Ookawara Shinichi , Ahmed Mahmoud 
Published: January 2020

Abstract
Stenosis is abnormal narrowing of blood vessels that causes a shortage in blood supply and a blockage of an artery Diagnosis of its severity guides the physician to determine the most appropriate treatment plan. Fractional flow reserve (FFR) is currently the most accurate procedure in stenosis diagnosis. It is a guidewire based technique that uses a small sensor on the tip of the wire to measure proximal and distal pressure of the stenosis. The difficulty of using such method is placing the guidewire precisely in centerline of blood vessel. Therefore, the main objective of the current study is to investigate how the measured pressure varies with the guidewire position. Accordingly, three different positions from the blood vessel centerline along with three degrees of severity are considered. The governing equations for blood flow are obtained and numerically simulated. Numerical results are validated using the available experimental and numerical data. A good agreement between predicted and measured values are obtained. Based on the predicted results, pressure drop coefficient (CDP) and pressure recovery factor (η) are computed. The predicted results with and without the effect of existing guidewire at different location are analyzed and the certainty of fractional flow reserve is reported and discussed. The current method is very helpful to increase the accuracy of fractional flow reserve procedure in stenosis severity estimation.
Mechanical Behavior of Thermosetting Polymers Undergoing High Strain-Rate Impact
Authors: Sable Peter , Borg John P. 
Published: January 2020

Abstract
A series of uniaxial and oblique flyer-plate impact experiments were conducted on fully dense, high durometer, polyurethane and epoxy formulations to investigate the high strain-rate dynamic material response. Samples were impacted at velocities ranging from 50 to 1,200 m/s at strain-rates of 105 – 106 s−1. The Hugoniot constants, yield strengths, and friction coefficients were inferred from velocity measurements taken from the back surface of the targets. Polymer Hugoniots were found to closely approximate those previously found in literature, with nonlinear curvature at low impact speeds due to viscoelastic effects. Strength behavior demonstrated pressure dependence which fit into a Mohr-Coulomb or Drucker-Prager yield surface criterion. Coefficients of friction between both epoxy and polyurethane, alongside a 7075-T6 aluminum tribological partner were quantified and results were used in conjunction with yield observations to hypothesize on the role of adhesion in high strain-rate shear of polymer-metal interfaces.
Low-Cost Particulate Detection in Bleed Air
Authors: Waez Mir Seliman , Eckels Steven J. , Sorensen Christopher M. 
Published: January 2020

Abstract
Bleed air is brought into aircraft cabins in order to maintain the quality of the air for passenger and crew health and comfort. The bleed air can be contaminated by oil due to oil seal leaks in the compressor which have been reported randomly and generated significant public interest. Previous studies have measured the particulate size distribution in the bleed air entering the cabin, but never distinguished the type and material of the particulate matter (PM). The particulates could be potentially hazardous oil droplets from the oil seal leaks, water droplets due the presence of fog generated by the cooling system, and so on. In this study we propose a novel technique using light scattering technology to distinguish between contaminant types. This technique uses size and complex index of refraction as the measure. Since each material has a distinct index of refraction, by determining the index of refraction, our proposed low-cost detector could distinguish the compound in the aerosol as well as determine the particle size simultaneously.
Clustering of Human Motion Trajectory for Lower Limb Rehabilitation Robot Design Based on Machine Learning
Authors: Zhao Kangren , Teng Zhiqiang , Gong Ningtao , Chen Fangkang , Zhao Ping 
Published: January 2020

Abstract
Lower limb rehabilitation robots, which usually produce repeated rehabilitative motion, not only simulate general human walking to help patients practice, but also do benefits to the remodel central nervous system to learn and store correct motion model. However, patients with different body parameters usually have different lower limb motion trajectories, and sometimes even the same person’s multiple motion trajectories could differ, thus the task of designing a specific lower limb rehabilitation mechanism for the realization of every motion trajectory is not practical. In this paper, we propose an approach to the clustering of motion trajectories of human lower limb to obtain a limited number of rehabilitation task motion types. Firstly, Gaussian distribution is adopted for the fitting of multiple trajectories of the same person. Through comparison of various clustering algorithms according to separation and compactness, Hierarchical clustering algorithm is chosen to obtain the partitions of the clusters. Finally, the Gaussian process regression (GPR) model of each cluster is established. Results show that clusters generated by this approach can reflect motion trajectory of the subjects and predict human lower limb motion pattern. With a limited number of lower-limb motion patterns, the design task of rehabilitation robots could be greatly simplified.
Comparing Electrowettability and Surfactants As Tools for Wettability Enhancement on a Hydrophobic Surface
Authors: Lokanathan Manojkumar , Sharma Himanshu , Shabaka Mostafa , Bahadur Vaibhav , Mohanty Kishore 
Published: January 2020

Abstract
Wettability alteration has significant applications in microfluidics, energy production and process engineering. Surfactants have been widely used for wettability alteration on surfaces. More recently, electrowetting (EW) has emerged as a powerful microfluidic technique to dynamically alter wettability. EW relies on the application of an electrical potential difference across a dielectric layer on which the fluid rests.
This work analyzes the extent of wettability enhancement of water droplets on a hydrophobic surface (in air) via the use of surfactants and EW. Nine surfactants were chosen from the categories of anionic, cationic and zwitterionic surfactants. The critical micelle concentration (CMC) of these surfactants, and the wettability of surfactant-infused water droplets was measured at post and pre-CMC concentrations. Next, experiments were conducted to quantify the wettability enhancement of water droplets (with surfactants) via EW.
Many interesting insights on the interplay between surfactants and electric fields are uncovered in this work. As expected, adding surfactants enhances wettability up to the CMC. EW can further enhance wettability of surfactant solutions and further reduce the contact angle by as much as 30°. Interestingly, it is seen that the influence of EW in enabling CA reduction is reduced by the addition of surfactants at pre-CMC levels. Conversely, surfactants strengthen the influence of EW at higher concentrations. It is noted that the extent of wettability alteration via EW is limited by the phenomena of contact angle saturation, wherein the contact angle saturates beyond a certain voltage. Interestingly, it is seen that at post CMC concentrations, the saturation contact angles are independent of surfactant concentrations.
Gait Analysis in the Assessment of Patients Undergoing a Total Hip Replacement
Authors: Regazzoni Daniele , Vitali Andrea , Colombo Zefinetti Filippo , Rizzi Caterina 
Published: January 2020

Abstract
Nowadays, healthcare centers are not familiar with quantitative approaches for patients’ gait evaluation. There is a clear need for methods to obtain objective figures characterizing patients’ performance. Actually, there are no diffused methods for comparing the pre- and post-operative conditions of the same patient, integrating clinical information and representing a measure of the efficiency of functional recovery, especially in the short-term distance of the surgical intervention.
To this aim, human motion tracking for medical analysis is creating new frontiers for potential clinical and home applications. Motion Capture (Mocap) systems are used to allow detecting and tracking human body movements, such as gait or any other gesture or posture in a specific context. In particular, low-cost portable systems can be adopted for the tracking of patients’ movements. The pipeline going from tracking the scene to the creation of performance scores and indicators has its main challenge in the data elaboration, which depends on the specific context and to the detailed performance to be evaluated.
The main objective of this research is to investigate whether the evaluation of the patient’s gait through markerless optical motion capture technology can be added to clinical evaluations scores and if it is able to provide a quantitative measure of recovery in the short postoperative period.
A system has been conceived, including commercial sensors and a way to elaborate data captured according to caregivers’ requirements. This allows transforming the real gait of a patient right before and/or after the surgical procedure into a set of scores of medical relevance for his/her evaluation.
The technical solution developed in this research will be the base for a large acquisition and data elaboration campaign performed in collaboration with an orthopedic team of surgeons specialized in hip arthroplasty. This will also allow assessing and comparing the short run results obtained by adopting different state-of-the-art surgical approach for the hip replacement.
Optimizing Pulse Combustion Parameters in Carbon Anode Baking Furnaces for Aluminum Production
Authors: Tajik Abdul Raouf , Shamim Tariq , Ghoniem Ahmed F. , Abu Al-Rub Rashid K. 
Published: January 2020

Abstract
Pulsating flame jets have been widely used in open-top carbon anode baking furnaces for aluminum electrolysis. Reducing energy consumption and pollutant emissions are still major challenges in baking (heat-treatment) carbon anode blocks. It is also of immense significance to bake all the anodes uniformly irrespective of their position in the furnace. Baking homogeneity can be enhanced noticeably by optimizing anode baking operational, geometrical, and physical parameters. In the present study, CFD simulations are combined with a response surface methodology to investigate and optimize the effects of pulse pressure, pulse frequency, and mainstream inlet oxygen concentration and mainstream inlet temperature. Two-levels half fractional factorial design with a center point is employed. It is perceived that pulse combustion with short pulse time and high momentum results in significant enhancement of the anode baking furnace energy efficiency. The temperature homogeneity is also significantly improved. It is found that the oxygen concentration is statistically the most significant parameter on NOx and soot formations, followed by the fuel flow rate. For NOx formation, air inlet oxygen concentration has a strong interaction with pulse duration. Coupling CFD models with the response surface methodologies demonstrated great potential in multi-objective optimization of the anode baking process with enhanced energy efficiency and baking uniformity.
Investigating Effects of Different Flue-Wall Deformation Modes on the Performance of Anode Baking Furnaces for Aluminum Electrolysis
Authors: Tajik Abdul Raouf , Zaidani Mouna , Shamim Tariq , Abu Al-Rub Rashid K. 
Published: January 2020

Abstract
In carbon anode baking furnaces, temperature and quality of carbon anodes are significantly affected by the deformation of the flue-walls, where the flue-gases flow and combustion occur. Flue-walls aging gives rise to non-homogeneous baking of the carbon anodes and results in deterioration of the anode quality, which eventually causes instabilities in aluminum reduction cells and overconsumption of anodes and energy. It is imperative to develop a fully coupled 3D multi-physics computational model which takes into account a large number of physical phenomena that play vital roles in the baking process and are affected by the flue-wall deformation mode. In the present study, the effects of flue-wall deformation modes on flue-wall cavity gas flow and anode temperature distribution are investigated. The pressure and flow distributions for different levels of flue-wall deformation are demonstrated. It is perceived that a 100 mm convex mode of flue-wall deformation leads to under-baking of anodes by almost 20 degC. For the concave mode of deformation, since the packing coke thickness reduces, overbaking of anode occurs. The methodology and results presented in the present research can be employed effectively by the aluminum industry in modifying the furnace geometrical and operational parameters to enhance baking uniformity after flue-wall is deformed.
Novel Electro-FSI Model of Trabecular Network in the Brain Sub Arachnoid Space
Authors: Teimoori Khashayar , Sadegh Ali M. , Paneri Bhaskar 
Published: January 2020

Abstract
The brain is encased in the skull and suspended and supported by a series of three fibrous tissue layers: Dura mater, Arachnoid and Pia matter, known as the Meninges. Arachnoid trabeculae are strands of collagen tissues located in a space between the arachnoid and the pia matter known as the subarachnoid space (SAS). The SAS trabeculae play an important role in damping and reducing the relative movement of the brain with respect to the skull. The SAS is filled with cerebrospinal fluid (CSF), which is a colorless fluid that surrounds all over the brain inside the subarachnoid spaces. This fluid stabilizes the shape and position of the brain during head movements.
To address normal and pathological SAS functions, under conditions where an electrical stimulation is applied, this study proposes a novel fully-coupled electro-Fluid-Structure Interaction (eFSI) modeling approach to investigate the response of the system of SAS-CSF under the applied electric current, which is provided by the transcranial Direct Current Stimulation (tDCS) technique according to the following steps. First, a two-dimensional channel model of the brain SAS with several trabecular morphologies is numerically simulated using the finite element (FE) method. The channel model is then subjected to a specific electric field intensity by applying a 1∼2mA direct current. COMSOL Multiphysics v. 5.3a software is used to perform the coupled eFSI numerical simulation in order to investigate the effects of the applied electric field on the flow of the CSF, thereby showing the deflection of the trabeculae inside the channel model.
The results of this study demonstrate that the induced electric field causes less deflection of the trabeculae by exacerbating the velocity profile of the cerebrospinal fluid flow and decreasing the flow pressure applied on each trabecula inside the trabecular SAS channel. This electro-mechanostructural modeling approach is significant because of the applied current on the channel walls that can directly affect the CSF flow. In fact, the results of this study can open up a new horizon for future research on disorders like hydrocephalus, which involves an unusual production rate of the CSF inside the brain. This disorder may be controlled by applying an electric current in the brain, using one of the available brain stimulation techniques, i.e. tDCS. By using an electrical stimulation technique, one might control the dynamics of brain function and, therefore, regulate dysfunctionality through the first eFSI multiphysics modeling approach proposed in this study. Briefly, the brain SAS may be considered as a novel region for electrotherapeutic and electromechanical neuromodulation.
Deck Lid Surround Fit Correlation Study Between Dimensional Variation Simulation and Physical Vehicle
Authors: Zhongwu Han , Min Hu , Zhenhai Ma , Xiaoxu Niu , Ni Cao 
Published: January 2020

Abstract
During vehicle development process, dimensional variation simulation has been applied to evaluate fit performance of build variation widely, including front end area, rear end area, interior and chassis. Both product and process variation are simulated based on rigid assumptions in traditional variation simulation model, but many components are not rigid and deformed after assembled on physical vehicle, which make the variation simulation model result not correlate with physical build well. Deck lid is kinetic and easy to be elastic deformed that is caused by torque rod and seal force, which would affect deck lid surround fit, especially for deck lid to body side outer flush, but these situations are not considered in traditional variation simulation model. In order to improve the correlation between dimensional variation simulation and physical vehicle variation, in this paper, deck lid deformation is considered in new variation simulation model.
Compared with traditional method, the correlation between new variation simulation model and build variation on physical vehicle improved by 17%. This calculation method and result are closer to physical build than traditional variation simulation, limit of this study is seal margin variation, striker and bumper adjustment are not considered in FEA model. In future study, need to improve the correlation by considering all these factors. This study could be applied to identify actual vehicle fit risk in product development phase, it could also save tooling change cost in build period.
Enabler Study for Plan View Cutline Styling of Front End Based on Variation Simulation
Authors: Siyuan Jin , Min Hu , Yabin Chen 
Published: January 2020

Abstract
In current automobile market, plan view outline styling between hood and front fascia is very popular and customers are sensitive to this styling. How to assure high aesthetic quality with low cost is very important for automotive engineers. In this paper, the variation simulation model of the usual and a new method is established and compared by 3DCS software. The development method with a new locating strategy and installation process for fascia center bracket is presented to optimize product development and process enablers. Finally, the validity of the proposed method is verified on physical model.
Finite-Element Analysis of the Load Factor and Design for Bolted Circular Flange Joints Consisting of Dissimilar Clamped Parts Under Tensile Loadings
Authors: Sawa Shunichiro , Sekiguchi Yasuhisa , Sawa Toshiyuki 
Published: January 2020

Abstract
The load factor for bolted circular flange joints where two dissimilar material (steel-aluminum) of circular flanges are clamped by a lot of bolts and nuts under external tensile loadings is examined newly using Finite Element analysis. Furthermore, the effects of the bolt pitch circle diameter D and number of tightened bolts N on the load factor and a load when the interfaces start to separate are examined. The value of the load factor for steel-aluminum circular flange joint is a little bit larger than that for steel-steel circular flange joints and it increases as the value of D decreases. In addition, it decreases as the value of N increases. A maximum bending stress is also found newly about 5% larger than the bolt stress due to the load factor. The experiments to measure the load factor, the maximum bending bolt stress and a load when the interfaces start to separate were carried out. The FEM results are fairly coincided with the experimental results. Finally, based on the obtained load factor, a design method for bolted joints with dissimilar circular flanges is demonstrated for determining the nominal bolt diameter and the bolt strength grade and the effect of bolt number N is examined. It is found that the contact stress at the bearing surfaces of aluminum circular flange is critical and it is shown that washers are needed in some cases.
Developing a Cost-Effective and Functional Prosthetic Foot for Below Knee Amputees Using Topology Optimization and 3D Printing
Authors: Kamel Hisham , Harraz Omar , Attia Tamer 
Published: January 2020

Abstract
This paper presents the results of an investigative study on the development of an affordable and functional prosthetic foot for below knee amputees. A prototype was successfully manufactured using 3D printing technology. This continuously evolving technology enables the rapid production of prosthetics that are individually customized for each patient. Our prototype was developed after conducting a topology optimization study that interestingly converged to the shape of the biological human foot. Afterwards, a design was envisioned where a simple energy storage and release mechanism was implemented to replace the Achilles tendon, which minimizes the metabolic energy cost of walking. Our mechanism can successfully manage 70% of the energy compared to a normal person during each walking step. A finite element (FE) model of the prosthetic was developed and validated using experimental tests. Then, this FE model was used to confirm the safe operation of the prosthetic through simulating different loading scenarios according to the ISO standard. Our study clearly showed that customizable prosthetics could be produced at a fraction 1/60 of the cost of the commercially sold ones.
Deformation Mechanics of Tube in Variation of Process Sequence During Low Pressure Tube Hydroforming
Authors: Nikhare Chetan P. 
Published: January 2020

Abstract
Tube hydroforming is the successful manufacturing process to create a variety of shapes using fluid pressure. In this process, the tube was filled with the fluid and further pressurized to deform to various shapes. Tube hydroforming is categorized into three types: higher pressure, pressure sequencing and low-pressure tube hydroforming. Ferrous and non-ferrous metals are formed using these processes. Due to uniform thinning in the formed part, the parts can be lower weight and thus proven to be the technology to create lightweight parts for automotive and aerospace industries. This process has gained popularity due to its many advantages such as part consolidation, quality of the formed part and the possibility of unique shapes with indents or angles. This paper focuses on low-pressure tube hydroforming. In low-pressure tube hydroforming, during the closing of the die the tube is marginally pressurized to a fixed volume. The focus of this paper is to investigate the deformation mechanics of the tube due to variation in the process sequence during low-pressure tube hydroforming. The circular tube was formed in a square shape. The four sides of die edges were considered as individual edges and the motion of these edges will be varied to achieve the final shape. The deformation mechanics in each condition was presented and analyzed. The thickness and strain distribution were studied. The change of tube profile pattern from the start to the end of the process were presented and compared.