bluuebunny/crossref_metadata_2025_split huggingface dataset:
How Does Physical Activity Affect Residual Limb Volume Change, Comfort and Gait Symmetry on Traumatic Transfemoral Amputees?
Authors: Salazar-Salgado Sara , Valencia Fanny , Uribe Alejandro , Rendón-Vélez Elizabeth 
Published: February 2021

Abstract
There is a considerable amount of young adults who become amputees due to war and violence. For this population, a successful adaptation to their prosthesis depends on the socket fit, which in turn is caused by the volume change of the residual limb during the day. The literature reports several investigations on this topic, most of which use subjects walking on a treadmill to simulate their daily activity. However, this studies are focused on transtibial amputees and do not mention the relationship between this physical activity and other variables such as comfort, volume changes and gait. Therefore, the objective of this paper is to determine the effect of physical activity on the volume of the residual limb, the comfort and the symmetry of gait in traumatic transfemoral amputees.
Plaster positive molds of the residual limb, the comfort perception and the gait data of five individuals were obtained at the first time of the day and after three sessions of treadmill walking of 15, 30 and 45 minutes. The positive molds of each individual were scanned and then, the volume was calculated. The gait data was acquired using a marker-based motion capture system and processed to obtain spatio-temporal, kinematic and kinetic parameters, including the Gait Deviation Index (GDI). Based on the literature, specific points of the gait data were selected and the symmetry index was obtain for each of them. A short comfort test was used after each session of treadmill walking. Data was analyzed throughout the tests within each subject. Statistical analysis was performed for the volume and the gait variables to check for statistical significance.
After physical activity, a tendency towards residual limb volume decrease was found on almost all subjects, although it was not significant. The percentage of volume change obtained on almost all subjects are within the range considered “good socket fit” according to previous authors. Our results suggest that transfemoral amputees may have smaller volume changes than transtibial after treadmill walking. Significant difference was found on the symmetry index of “Swing phase” between the baseline and the 45-minute test. The values of gait symmetry on the gait parameters were consistent with previous findings regarding transfemoral amputees. The difference that arise may be due to the sample difference (cause of amputation, difference in prosthetic elements and use of walking aids). The lowest symmetry was noticed on the ankle kinematics. The comfort did not significantly change with the selected amount of physical activity.
In subsequent research, it is recommended to increase the intensity or time of physical activity and/or increase the number of participants. This results can help the understanding of how the socket/residual limb interface behaves which can improve the design and prescription of prosthetic components.
Experimental Investigation of Proton Exchange Membrane Fuel Cell With Platinum and Nafion Along the In-Plane Direction
Authors: Cheng Peng , Tongsh Chasen , Liang Jinqiao , Liu Zhi , Du Qing , Jiao Kui 
Published: February 2021

Abstract
In this study, an experimental study has been performed to investigate the effect of in-plane distribution of Pt and Nafion in membrane electrode assembly (MEA) on proton exchange membrane (PEM) fuel cell. Two types of MEAs, such as the gradient and uniform distributions of Pt catalyst and Nafion, are compared under various operating conditions including cathode flow rate, MEA preparation method, Pt loading and relative humidity (RH).
The catalyst ink is sprayed onto Nafion membrane or gas diffusion layer (GDL) through a pneumatic automatic spraying device manufactured by ourselves. MEA is prepared by hot pressing. The results show that as flow rate decreases, the MEA with gradient distribution will show a higher voltage at a high current density for catalyst coated membrane (CCM) method. For CCM method, gradient distribution can optimize cell performance under low cathode flow rate, but the optimization effect is weakened when flow rate is too low. Compared with CCM method, the gas diffusion electrode (GDE) method makes the difference value of Ohmic resistance between gradient and uniform distribution very larger, resulting in poor performance improvement. For GDE method, gradient distribution shows no optimization for cell performance under different Pt loadings and RH, but a smaller average Pt loading and fully-humidified reactants can reduce the performance distinction between uniform and gradient distribution. The gradient design of Pt and Nafion along the in-plane direction is a promising strategy to improve the performance of PEM fuel cell. Reasonably controlling the gradient distribution of Pt in the plane direction of cathode can reduce the amount of Pt catalysts and improve efficiency.
Knowledge-Driven Based Performance Analysis of Robotic Manufacturing Cell for Design Improvement
Authors: Kangru Tavo , Mahmood Kashif , Otto Tauno , Moor Madis , Riives Jüri 
Published: February 2021

Abstract
Manufacturing companies must ensure high productivity and low production cost in rapidly changing market conditions. At the same time products and services are evolving permanently. In order to cope with those circumstances, manufacturers should apply the principles of smart manufacturing together with continuous processes improvement. Smart manufacturing is a concept where production is no longer highly labor-intensive and based only on flexible manufacturing systems, but production as a whole process should be monitored and controlled with sophisticated information technology, integrated on all stages of the product life cycle. Process improvements in Smart Manufacturing are heavily reliance on decisions, which can be achieved by using modeling and simulation of systems with different analyzing tools based on Big Data processing and Artificial Intelligence (AI) technologies.
This study was performed to automate an estimation process and improve the accuracy for production cell’s performance evaluation. Although there have been researches performed in the same field, the substantial estimation process outcome and accuracy still need to be elaborated further.
In this article a robot integrated production cell simulation framework is developed. A developed system is used to simulate production cell parametric models in the real-life situations. A set of rules and constraints are created and inserted into the simulation model. Data for the constraints were acquired by investigating industries’ best production cells performance parameters. Information was gathered in four main fields: company profile and strategy, cell layout and equipment, manufactured products process data and shortcomings of goal achievements or improvement necessary to perform. From those parametric case model, a 3D virtual manufacturing simulation model is built and simulated for achieving accurate results.
The integration of manufacturing data into decision making process through advanced prescriptive analytics models is a one of the future tasks of this study. The integration makes it possible to use “best practice” data and obtained Key Performance Indicators (KPIs) results to find the optimal solutions in real manufacturing conditions. The objective is to find the best solution of robot integrated cell for a certain industry using AI enabled simulation model. It also helps to improve situation assessment and deliberated decision-making mechanism.
Study on Natural Vibration Characteristics Based on the Coupled Wave Theory of Spring Supported Elastic Pipes and Fluids
Authors: Tokunaga Takeshi , Mori Koji , Kadowaki Hiroko , Saito Takashi 
Published: February 2021

Abstract
A gradient of a blood flow velocity on the surface of a blood vessel is one of the clinical medicine concerns from the view point of prevention of the arteriosclerosis.
In previous study, we formulated a relationship between the pressure and a flow velocity based on the coupled wave theory of elastic pipes and Newtonian fluids [1]. In addition, a flow velocity distribution and a wall shear stress are estimated by using the blood pressure data, which are non-invasively obtained by the tonometry method. This method is quasi-analytical method to apply the coupled wave theory for industrial flow field inside steel pipes proposed by Urata [4] to blood vessel, and has the advantage of systematic estimator compared with the numerical calculation. However, the coupled wave theory has applied to the elastic pipes that were assumed to be infinitely long. In addition, a single wave was assumed to be dominant within the elastic pipes and the Newtonian fluids. Therefore, in order to apply various length vessels in clinical field, the boundary of the blood vessels that varies from site to site, and the natural vibration characteristics that depend on the boundary conditions, could not be reflected in the wall shear stress estimation. In general, in order to solve the forced vibration with the boundary condition, it is necessary to clarify natural frequency and natural mode as natural vibration characteristics of structure.
In this study, we introduce the spring supported elastic pipes to the coupled wave theory and formulated a relationship between the natural vibration characteristics and the boundary conditions. In this proposed method, the spring-supported elastic pipe has a feature that can be treated as an arbitrary boundary condition of an artery by giving an appropriate spring coefficients. Therefore, it is easy to apply to various types of blood vessels clinically. By investigating the natural vibration characteristics of blood vessels that varies from site to site, it may be possible to clarify fluctuations of blood flow in response to blood pressure with some frequency-bands. In addition, natural angular frequencies and natural modes of the spring supported elastic pipes and the Newtonian fluids were estimated for general blood vessel based on the coupled wave theory. In the result, the natural angular frequencies and the natural modes that reflect the clinical vibration characteristics to some extent can be estimated. On the other hand, particular modes may not reflect boundary condition, and further examination of the relationship between natural vibration characteristics and boundary condition is needed.
Beam Hardening Artifact Reduction in X-Ray CT Reconstruction of 3D Printed Metal Parts Leveraging Deep Learning and CAD Models
Authors: Ziabari Amirkoushyar , Venkatakrishnan Singanallur , Kirka Michael , Brackman Paul , Dehoff Ryan , Bingham Philip , Paquit Vincent 
Published: February 2021

Abstract
Nondestructive evaluation (NDE) of additively manufactured (AM) parts is important for understanding the impacts of various process parameters and qualifying the built part. X-ray computed tomography (XCT) has played a critical role in rapid NDE and characterization of AM parts. However, XCT of metal AM parts can be challenging because of artifacts produced by standard reconstruction algorithms as a result of a confounding effect called “beam hardening.” Beam hardening artifacts complicate the analysis of XCT images and adversely impact the process of detecting defects, such as pores and cracks, which is key to ensuring the quality of the parts being printed. In this work, we propose a novel framework based on using available computer-aided design (CAD) models for parts to be manufactured, accurate XCT simulations, and a deep-neural network to produce high-quality XCT reconstructions from data that are affected by noise and beam hardening. Using extensive experiments with simulated data sets, we demonstrate that our method can significantly improve the reconstruction quality, thereby enabling better detection of defects compared with the state of the art. We also present promising preliminary results of applying the deep networks trained using CAD models to experimental data obtained from XCT of an AM jet-engine turbine blade.
An Innovative Approach to CTCs’ Liquid Surgery
Authors: Fontanili Luca , Milani Massimo , Montorsi Luca , Scurani Letizia , Venturelli Matteo , Fabbri Francesco 
Published: February 2021

Abstract
Circulating Tumor Cells (CTCs) can be defined as cancerous cells, which detach from a tumor and flow through the vascular or lymphatic systems. The blood flow can carry the tumor cells in another region of human body where they can become the starting point for the growth of additional metastases. Because of this behavior, in the CTCs study it is paramount to acquire new data and knowledge to understand the mechanisms that lead to the separation of the cell from the tumor as well as the major characteristics of these cells. The aim of this work is the development of an innovative therapeutic and diagnostic approach able to lead to a new medical device for removing CTCs from the peripheral blood of a patient. The main target of the approach is to detect the CTCs and separate them during a conventional extracorporeal circulation procedure, similar to that used for renal failure. In this work, the CTCs physical properties are investigated in order to explore the possible characteristics that can be exploited in an ad-hoc developed medical device to remove them from the blood flow. The CTCs physical properties are analyzed numerically, and their behavior is studied by means of CFD simulations. The preliminary numerical tests have been carried out on simple geometries in order to assess the influence of magnetic and electric fields on tumor cells’ trajectory. These results are the baseline information to develop more complicated geometries and prototypes for real operations.
Human Thoracolumbar Spine Tolerance to Injury and Mechanisms From Caudo-Cephalad Impacts
Authors: Yoganandan Narayan , Khandelwal Prashant , Porwal Vaibhav , Humm John 
Published: February 2021

Abstract
The human thoracolumbar spinal column sustains axial loading under physiological and traumatic loading situations. Clinical studies have focused on the former scenario, and the investigation of low back pain issues and spinal stabilization using artificial devices such as arthroplasty are examples. Investigative studies have largely used quasi-static and vibration loading on the spine segment(s) and spinal columns. The traumatic loading scenario is relatively less researched, and it is a dynamic event. Injuries under this scenario occur in sports, automotive, and combat environments. Impact vectors include flexion-extension modes in automotive crash events. Vertical or caudal to cephalad oriented impacts have been identified in both automotive and military scenarios. Frontal impacts to restrained occupants in the automotive and underbody blast impacts from improvised explosive device in combat situations are examples of the vertical loading vector. Although some studies have been conducted using whole body human cadavers and isolated spinal columns, determinations have not been made of the injury risks and stress and strain responses for a variety of accelerative pulses. The aims of the present investigation were to delineate the internal biomechanics of the spinal column under this impact vector and assess the probability of injury. Male and female whole-body human finite element models were used in the study. The occupants were restrained and positioned on the seat, and caudo-cephalad impacts were applied to the base. Different acceleration-time profiles (pulse durations ranging from 50 to 200 ms and peak accelerations varying from 11 g to 46 g) were used as inputs in both male and female models. The resulting stress-strain profiles in the cortical and cancellous bones were evaluated at different vertebral levels. Using the peak transmitted forces at the thoracolumbar disc level as the response variable, the probability of injury for the male spine was obtained from experimental risk curves for the various accelerative pulses. Results showed that the shorter pulse durations and rise times impart greater loading on the thoracolumbar spine. The analysis of von Mises stress and strain distributions showed that the compression-related fractures of vertebrae are multifaceted with contributions from both the cortical and cancellous bony components of the body. Profiles are provided in the body of the paper for different spinal levels. The intervertebral disc may be involved in the fracture mechanism, because it acts as a medium of load transfer between adjacent vertebrae. Injury risks for the shortest pulse was sixty-three percent, and for the widest pulse it was close to zero, and injury probabilities for other pulses are given. The present computational modeling study provides insights into the mechanisms of the internal load transfer and describe the injury risk levels from caudal to cephalad impacts.
Evaluating the Effect of a Student-Centered Pedagogical Approach on Students’ Skills and Knowledge in Computer-Aided Design (CAD) Course
Authors: Peng Xiaobo , Jackson Malcolm , Duan Chang , Han Mingli , Yalvac Bugrahan , Hing Ebony Lai , Ketsetzi Antonia , Eseryel Deniz 
Published: February 2021

Abstract
This paper presents a quasi-experimental pre and post test design to explore the effects of a student-centered pedagogical approach in Computer-Aided Design (CAD) education. In this study, students in experimental group generated CAD screencast tutorials, recorded the supporting audio, shared the videos with their peers, and provided feedback to each other’s screencast. A life-long learning survey, an engineering attitude survey, and a CAD modeling exam were used as the study instruments. Students’ learning outcomes were evaluated by analyzing data collected over five years from 17 classrooms. Findings indicated that first generation college students or female students were more receptive to the student centered instructional approaches and they improved their life-long learning skills and engineering attitudes. We observed a strong evidence that when students designed screencast exercises, their CAD exam performance improved. This study also contributes to our knowledge on how to effectively assess engineering attitudes and life-long learning skills.
Experimental Study of Multiple Air Jets Impinging a Moving Flat Plate
Authors: Barbosa Flavia , Teixeira Senhorinha , Costa Carlos , Marques Filipe , Teixeira José Carlos 
Published: February 2021

Abstract
The motion of the target plate is important in some industrial applications which apply multiple jet impingement, such as reflow soldering, drying and food processing. Multiple jet impingement is widely used due to its ability to generate high heat transfer rates over large and complex areas. This convective process is characterized by several flow interactions essentially due to adjacent jets mixing prior the impingement, wall jets collision after the impingement, as well as crossflow interactions induced by the motion of the wall jets that flow through the exits of the domain. These interactions lead to strong flow recirculation, pressure gradients and boundary layer development. However, the complexity of the flow interactions is increased with the surface motion in confined space, due to the generation of strong shear regions. These interactions can induce problems and product defects due to complicated thermal behavior and non-uniform heating or cooling, being important to fully understand the process in order to reduce time and costs. This work addresses the experimental analysis of multiple air jets impinging on a moving flat plate. The experiments are conducted on a purpose-built test facility which has been commissioned, using a 2D-PIV system. Through this technique, the flow structure and velocity profiles will be analyzed in detail. The effects of the impinging plate motion on the resulting global and local velocity profile is compared with a static flat plate. The multiple jet configuration consists on air flowing through 14 circular nozzles, at a Reynolds number of 690 and 1,380. The experiments are conducted for a nozzle-to-plate distance of 8 and a jet-to-jet spacing of 2. The target plate motion remains constant throughout the experiments and equal to 0.03 m/s. The results are compared for both stationary and moving flat plates cases and express the increased complexity of the flow due to strong interaction between jets and the target surface, which affects the heat transfer performance. The results obtained experimentally are important to clearly define this complex flow and these data can be used in future works for numerical model validation.
Ontologies As a Tool for Design and Material Engineers
Authors: Pigazzi Riccardo , Confalonieri Chiara , Rossoni Marco , Gariboldi Elisabetta , Colombo Giorgio 
Published: February 2021

Abstract
Functionally Graded Materials (FGMs), initially conceptualized in the ’80, have recently attracted a great research interest thanks to the advent of additive manufacturing (AM) technologies. AM permits to gradationally varying the spatial composition or porosity inside an object resulting in a corresponding spatial change in material properties. The data about this new class of materials are radically different from the traditional engineering materials and require information about the object geometry. Moreover, traditional methods for product design are not sufficient to represent heterogeneous objects. The full exploitation of these technologies requires the synergy of material science, product modeling and manufacturing domain. Ontologies can play a crucial role for the integration, making the information accessible and understandable to both experts from different domains and machines. In this paper, a prototypical ontology for the characterization of FGM objects is proposed. Firstly, an already existing FGM ontology is analyzed, highlighting shortcomings and possible improvements. Then, the new ontology is proposed, focusing on the classes and relationships for accommodating material knowledge and geometrical information. The core idea, retrieved from the literature on heterogeneous object representation and transposed in an ontological fashion, is based on the mapping between the geometrical 3D space and the n-dimensional material space. After presenting the new ontology, a benchmark case study is described to test the effectiveness of this approach along with some competency questions an engineer might be interested in. The proposed ontology represents a first, crucial building block for a more complex system aiming to support the communication and knowledge sharing among different actors in engineering.