bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Pellet and Filament Form Integrated Multi-Material Additive Manufacturing Co-Extruder
Authors: Krishnanand  , Taufik Mohammad 
Published: January 2022

Abstract
There are two methods to 3D print a part using extrusion-based additive manufacturing technology namely filament-based and pellets/granules-based. Filament-based extrusion needed a wire form material called a filament, which is pushed by a motor and gear mechanism, into a heating zone. In the heating zone, it converts in semi-solid form and is extruded out of the nozzle to deposit in a layer-over-layer manner. This extrusion strategy needed a non-flexible filament, so it limits the variety of materials. Converting material into wire form also increases the cost of 3D printing. Pellet-based extrusion accepts the material in granules form. It is fed into the heating zone using an extrusion screw. This technology can accept a wide range of materials and eliminate the cost of producing filament. But pellet-based technology is still not being used on 3D printers, on the other hand, filament-based technology in the form of 3D printers is very popular in the market. So, in this study development of noble pellet and filament form integrated multi-material additive manufacturing co-extruder has been presented. The developed co-extruder is capable to accept material in filament form as well as pellet/granules form. This will help to 3D print a particular part with several materials. This hybrid form of the extruder is accommodating the features of both types of extrusion-based additive manufacturing. As per need, one can easily shift from filament extrusion to pellet/granules extrusion using this co-extruder.
Comparative Energy and Exergy Analysis of Large Capacity Ammonia-Water and Water-Lithium Bromide Vapor Absorption Refrigeration (VAR) Cycles
Authors: Khan Muhammad Saad , Kadam Sambhaji T. , Kyriakides Alexios-Spyridon , Hassan Ibrahim , Papadopoulos Athanasios I. , Rahman Mohammad Azizur , Seferlis Panos 
Published: January 2022

Abstract
District Cooling Plants (DCP) is the sustainable way of energy consumption, refrigeration, and supply of chilled water to end-users via chillers and distribution networks. Thermodynamic assessment of the vapor absorption refrigeration (VAR) in the open literature has been performed for cooling capacity well below the actual requirement (less than 300 kW) of DCP. Therefore, this work aims to investigate energy and exergy analysis of large-scale single effect VAR cycles operated on NH3-water and water-LiBr systems for a cooling capacity of 4000 kW and assess several operating parameters’ influence on cycle performance. Different parameters such as evaporator operating pressure (water-LiBR = 0.010–0.020 atm, NH3-water = 5.39–6.20 atm), chilled water outlet temperature (288–297 K), absorber temperature (300–305 K), condenser temperature (310–315 K), cooling output (2900–4000 kW) and heat input (4300–5500 kW) to the generator are varied during the parametric analysis. The exergy destruction analysis of the cycle’s components is also included in the study. Overall, the COP (0.89) and Exergy efficiency (89%) of water-LiBr were found to be higher than that of an equivalent NH3-water system which is 0.697 and 81%, respectively. The maximum exergy destruction was found at the absorber unit (24%), followed by the generator (23%). Furthermore, the NH3-water and water-LiBr simulations were optimized for different parametric conditions, and optimal operating conditions were identified for large-capacity district cooling systems. Therefore, the findings will provide the roadmap for designing and optimizing large-scale DCP operated on VAR cycles.
Strategic Management and Operational Energetic Education, Opportunity for Future Small Developers and Entrepreneurs
Authors: Radulescu Bogdan Alexandru , Radulescu Victorita 
Published: January 2022

Abstract
Romania, as part of the EU has adopted new legislation concerning international energetic exchanges, based on the rules of cooperation. This paper illustrates some new concepts and essential steps in engineering education and beyond. International rules and their implementation at national level need to be adapted to the new financial and economic realities, quite important, especially in the actual economic pandemic context. All rules and regulations are based on the market economy interconnected to the international grids, necessary in the development of business opportunities. The second part presents the analysis of the target market segmentation, based on possible new criteria. Given the objectives of analyzing attractiveness and competitiveness, the advantages of being an educated engineer based on the selection of the strategy choice are determined. Success depends on the ability to understand and generate customers. The analysis of the strategic role of small developer management to ensure competitiveness and economic efficiency is also mentioned. All new graduates, master or doctoral students specialists in power engineering will have to deal with the new strategic objectives of investments, new legislation and trends as solutions to minimize global warming, increase energy efficiency, utilization of renewable resources, and environmental protection.
Multibody Dynamic Adams Model of a Ball Screw Mechanism With Recirculation Channel
Authors: Bertolino Antonio C. , De Martin Andrea , Mauro Stefano , Sorli Massimo 
Published: January 2022

Abstract
The presence of the recirculation channel of ball screws is often ignored in literature mathematical models since steady state analyses are usually performed. However, high-fidelity dynamic models of these components should include it to correctly represent the motion of the spheres. This would allow to enhance the model realism and to use it as a virtual test bench, also for PHM purposes. This paper presents a detailed three-dimensional multibody model developed in the MSC ADAMS environment in order to exploit its capabilities to represent a contact between generic arbitrary shaped bodies, such as the recirculating channel and deflector. Consequently, no ideal constraints are arbitrarily imposed and the full dynamics of every component is fully described. A first model validation is performed extracting the ball passing frequency from the nut axial acceleration signal. Furthermore, the dependence of the load distribution on geometric errors and external force application point eccentricity is investigated.
Evaluation of Dimensional Accuracy of Additively Manufactured Metal Parts in Fused Filament Fabrication Process
Authors: Alyammahi Mozah Saeed , Atatreh Saleh , Susantyoko Rahmat Agung , Alkindi Tawaddod 
Published: January 2022

Abstract
Additive Manufacturing (AM) technologies have been recently adopted to produce functional spare parts in advanced applications. High dimensional accuracy is essential in these applications, where it is expected for the dimensions of manufactured parts to meet the design specifications and tolerances. Different additive manufacturing processes exhibit different dimensional accuracies. This paper investigated the dimensional accuracy of additively manufactured metal parts produced by Fused Filament Fabrication (FFF). We designed a new testing structure (Test-Part) incorporating multiple features in a single build. Two different metal materials, 17-4 PH stainless steel, and copper were used to manufacture the test parts. We also compared the dimensional accuracy of metal parts against a composite polymeric material, Onyx, fabricated using the FFF process. The manufactured Test-Parts were scanned using an advanced laser scanning technology to precisely measure the dimensions and capture the geometry’s details. A detailed three-dimensional analysis was conducted to evaluate the extent of resemblance between the manufactured parts and the CAD model. Results showed that the copper Test-Part exhibited the highest dimensional accuracy (lowest dimensional deviation compared to the CAD model) among the three materials. Overall, metal 3D printed parts exhibited better dimensional accuracy compared to composite polymeric parts.
A Systematic Study of Pedestrian Contrast and Detection From Vehicle Headlights
Authors: Bayan Fawzi P. , Timbario Thomas A. , Nelson Jonathan D. , Sheldon Stuart , Wahba Ronny E. , Keys Brandon 
Published: January 2022

Abstract
An important factor in evaluating the visibility of pedestrians at night is the contrast they offer an observer. This paper investigates and quantifies the influence of various parameters on contrast. An experiment was conducted using pedestrians and surrogate human models positioned along a grid in relation to the illuminated headlights of vehicles positioned on a dry asphalt roadway with no additional overhead lighting. As part of this experiment, headlight illuminance was mapped, and pedestrian luminance data were comprehensively collected to provide parametric data necessary to evaluate patterns affecting contrast. Luminance and illuminance data are presented in the form of three-dimensional plots and further related to visibility levels using the Adrian model. The results of this study highlight and quantify important factors present in night visibility of pedestrians. These include position of the pedestrian both longitudinally and laterally, reflectivity of the clothing, vertical variations in luminance and illuminance, the background, and headlamp characteristics. They emphasize that three-dimensional modeling of headlight illuminance and pedestrian luminance enhances the understanding of pedestrian contrast and visibility.
Effect of Leg Topologies on Thermal Reliability of Thermoelectric Generators Systems
Authors: Aljaghtham Mutabe , Celik Emrah 
Published: January 2022

Abstract
Increasing the temperature gradient across thermoelectric (TE) devices improves the TE power output significantly. However, enhanced thermal gradients lead to high thermal stresses and these stresses must be taken into consideration in the design process to develop TE systems with enhanced thermal reliability. The shape of TE leg plays a major role on the performance of these systems. Conventional prismatic TE leg structure has been the preferred leg topology commonly utilized in TE devices due to its simplicity and high thermoelectric performance. Other leg topologies have also been considered in the literature to quantify their effects on TE performance. This current study investigates the thermal reliability of a several TE leg topologies such as trapezoidal leg, butterfly leg, vertical and horizontal cross-shaped leg, X-leg, Y-leg, I-leg according to the construction of each shape. 3D numerical model is presented to quantify the Von Mises stresses of these configurations and compared to conventional rectangular TE leg shape. The vertical cross-shaped and butterfly configurations generate 36% and 27% TE power higher than the conventional rectangular TE leg, respectively. On the other hand, the conventional TE leg has the lowest thermal stress compared to other TE leg topologies.
Prediction of a Blast Induced Peak Particle Velocity in Mining Operations: A Fuzzy Mamdani and ANFIS-Based Evaluating Methodology
Authors: Machesa Mosa , Tartibu Lagouge K. , Okwu Modestus O. 
Published: January 2022

Abstract
Activities in the mining industries as a result of rock blasting is the cause of extreme rock vibration which is considered a serious environmental hazard. In most cases, explosives are often used for the disintegration of rocks in opencast mine. One of the major challenges often experienced in mining industries is the case of ineffective use of explosive energy while performing such opencast operation, this could lead to disproportionate ground vibration, often measured by peak particle velocity (PPV). To reduce such ground vibration and environmental impediments, it is important to adopt creative models for the effective prediction of PPV. Considering the inevitable impact on rock mass, neighbouring structures and sometimes on human beings, an accurate prediction of ground vibrations and the evaluation of the aftereffects must be carried out prior to the actual blasting event. This research is an exposition of the prediction performance of a blast-induced PPV using a creative model -Fuzzy Mamdani Model (FMM) and a hybrid algorithm -Adaptive Neuro-Fuzzy Inference System (ANFIS), in mining operation. These models are employed to predict the blast-induced PPV, which is a measurement of the movement or vibration of a single earth particle as the shock waves from a particular location or blasting event moves through the system. Experimental dataset used in this research consists of three (3) input variables (change weight per delay, distance and scaled distance) and forty-four (44) record samples; the peak particle velocity represents the experimental result. The dataset is fed into MATLAB 2020 platform as input parameters. Results obtained using the creative and hybrid algorithms were compared based on root mean squared error (RMSE) and correlation coefficient between the experimental and predicted values of the PPV. The regression values obtained are 0.8487 and 0.97729 for the Fuzzy Mamdani model and ANFIS model respectively. From the result obtained, the best vibration prediction was achieved using the ANFIS model. It can be concluded that the ANFIS model gave a better prediction in terms of speed of computation and prediction accuracy. It is recommended that other hybrid algorithms and metaheuristic techniques be introduced and compared with the existing solution models for effective prediction of PPV in mining operations.
Detection of Jamming and Filament Breakage in FDM Using Vibration of Feeder Stepper
Authors: Rooney Sean P. , Pitz Emil , Pochiraju Kishore 
Published: January 2022

Abstract
In the field of additive manufacturing (AM), mid-print failure is exceedingly common due to user error, bad design, or environmental factors that cannot be readily prepared for. This holds for most if not all types of AM, but perhaps none more so than the popular Filament Deposition Modeling (FDM) method machines. Absent total power failure, the bulk of the common modes of failure in FDM can be expressed as having an immediate impact on the mechanical system, whether that be a head collision due to warping, increased pressure on the stepper as it tries to push jammed filament, etc. The open loop nature of FDM machines does nothing to help the high rate of failure that FDM printers are known for compared to traditional methods of manufacturing. In this paper, a method for predicting failure due to mechanical malfunction of an FDM 3D printer is presented. The method proposed seeks to close the loop on FDM machines by characterizing the vibrations of the stepper motors which comprise an FDM machine. Using the acoustic emissions, a classifier is trained in order to assess the state of a print based off of supervised learning of known modes of failure. The resulting model is able to successfully predict jamming or air printing during a print with 90% training accuracy.
Effect of Stenosis Location on the Flow Distribution in Coronary Branches: Experimental and Numerical Study
Authors: Abuouf Yasser , Albadawi Muhamed , Ahmed Mahmoud 
Published: January 2022

Abstract
Coronary artery disease is the abnormal contraction of heart supply blood vessel. This contraction in the blood vessels limits the flow of oxygenated blood to the heart. Thus, diagnosing its severity helps physicians to select the appropriate treatment plan. fractional flow reserve is the most accurate diagnostic method because it estimates the reduction in blood flow. The flow is distributed between coronary branches. However, the stenosis could change the blood distribution percentage. Accordingly, some branches could have further reduction in blood flow. The aim of this study is measuring the blood distribution percentage and reduction in each branch in patient-specific right coronary artery experimentally and numerically. Moderate stenoses with 60% area ratio are added in three locations. The flow in each branch is measured. On the other hand, A comprehensive three-dimensional computational flow model is developed. The model is validated using the experimental results. The validated model is used to predict the results in case of non-Newtonian blood flow. Based on the predicted results, when the stenosis is far from the bifurcation, the reduction in the inlet and the branches is between 38.5% and 41% for all flowrates. However, the closer the stenosis to the bifurcation, the larger the reduction in the side branch compared to the inlet. It shows 100% reduction when the stenosis is 10mm away from the bifurcation and 66.5% when it is 25mm from the bifurcation compared to 64.3% and 55.5% in the main branch, respectively. Accordingly, the physician should not rely only on the reduction of flow in the stenosed artery and investigate further into the branches.
Influence of Arterial Wall Elasticity on Blood Flow Dynamic Factors of Stenotic Carotid Artery
Authors: Albadawi Muhamed , Abuouf Yasser , Ahmed Mahmoud 
Published: January 2022

Abstract
Carotid artery is the major blood vessel which carries oxygenated blood to the brain and the face. Atherosclerosis is a major arterial disease characterized by a progressive contraction of the blood vessel. It occurs due to the deposition of cholesterol and lipids beneath the internal layer of the artery which is called stenosis. Carotid artery stenosis causes serious implications which considered one of the leading causes of morbidity and mortality in most countries. The existence of stenosis had a significant effect on the blood flow dynamic factors. Adding the arterial wall response through the wall elasticity will achieve more accurate and realistic flow characteristics. In this study, the arterial wall elasticity through two-way Fluid-Structure Interaction (FSI) was considered to the developed model to calculate the blood flow dynamics. Moreover, blood dynamic factors will be used to investigate the flow characteristics with rigid and elastic arterial wall and temporal blood responses. To estimate the blood dynamic factors, a three-dimensional reconstructed patient-specific carotid artery geometry with realistic boundary conditions is considered. Hence, a three-dimensional comprehensive model including the non-Newtonian Carreau blood flow viscosity model under pulsatile flow conditions is developed. The two-way FSI procedure was performed by applying an arbitrary Lagrangian-Eulerian (ALE) formulation to calculate the arterial response. Results indicated that using FSI has a crucial role in investigating the blood flow dynamic factors which resulted in low shear stress, pressure gradient, and velocity distribution comparing to the rigid arterial wall response. The efficient use of Computational Fluid Dynamics (CFD) has the potential to shed light on the assessment of the stenosis severity by adding the arterial wall and temporal blood response to the developed model.
A Parametric Study of Piezoelectric Energy Harvesting by Vortex Induced Vibration of a Pair of Cylinders
Authors: Cornett Thomas , Chattopadhyay Arka P. , Esmaeilpour Mehdi 
Published: January 2022

Abstract
The design of a piezoelectric based device that uses interference bluff body to harvest wind energy is presented. Different prototypes including cantilever beam, cylinder as oscillating body, and cylinder as interference body were used and tested to investigate the effects of interference bluff body’s properties such as the size and distance from fix oscillating body on the performance of energy harvesting system. To compare the frequency of oscillating beam and its natural frequency, a numerical simulation based on Finite Element Method was performed to obtain the natural frequency of cantilever beam. It was found that the energy harvester can be greatly improved by placing a fixed bluff body as interference bluff body in upstream of the oscillating bluff body. Through experimental tests, this study reveals that both diameter of interference cylinder and the distance between oscillating and interference cylinder play a key role in the energy harvester’s performance. Moreover, two different modes of oscillation were observed, depending on diameter of interference cylinder and its distance from bluff body. For all cases, the Fast Fourier Transform (FFT) analysis was used to monitor the frequency of oscillating cylinder and these values were compared with the natural frequencies obtained by Finite Element Method’s analysis. The results showed that the shorter beams oscillate with a frequency of about 5 Hz, close to the natural frequency of 6Hz, while the longer beams oscillate with a frequency of about 2.2 Hz, close to the natural frequency of 2.17Hz.
Velocity and Heat Transfer Studies of an Impinging Jet Using Magnetic Resonance Velocimetry and Infrared Thermometry
Authors: Humbert Nathan , Galante Jack , Davidson F. Todd , Helmer David B. , Elkins Christopher J. , Tamm Gunnar O. , Benson Michael J. 
Published: January 2022

Abstract
Heat transfer performance of a single cylindrical orthogonal jet impinging on a flat plate was obtained through steady-state infrared (IR) thermometry. One Reynolds (Re) number of 23,000 based on pipe exit diameter was considered. The distance of the jet exit plane from the shim varied from two to ten times the impingement jet diameter in increments of two diameters. The observed temperature and constant heat flux boundary condition allowed for the calculation of a Nusselt (Nu) number distribution to estimate the heat transfer performance of the impingement jet. At the smallest separation distance of two diameters, the relative maximum heat transfer performance is found at the stagnation point followed by a second peak occurring at a radial distance of approximately two diameters from the stagnation point. Compared to all jet exit separation distances studied, the distance of six diameters exhibited the greatest magnitude Nusselt number at the stagnation point. A paired fluids experiment using Magnetic Resonance Velocimetry (MRV) techniques collected hydrodynamic data of a single impinging jet at a matching Re number of 23,000 and jet exit plane distances. This work provides relevant data for correlation of impingement cooling design through unique analysis of the fluid mechanics and heat transfer characteristics of a single impinging jet. Measurement uncertainty was assessed to range from +/−1% to +/−10% for Nusselt number and +/−7% for velocity.
Generalized Study on Time-Dependent Creep Analysis of Functionally Graded Thick-Walled Cylinders Under Thermal and Mechanical Boundary Conditions
Authors: Ahmed Jasem A. , Wahab M. A. 
Published: January 2022

Abstract
A multiscale model has been developed to investigate the creep behavior of functionally graded thick-walled cylinders. Finite element (FE) simulations are employed to evaluate the position-dependent parameters associated with creep constitutive law at the microscale. A macroscopic FE model solves the non-linear boundary value problem to determine the time-varying creep stresses and strains. The framework proposed can predict the creep response of functionally graded pressure vessels based on the constitutive behavior of the creeping matrix, and volume fraction profile. Effective creep properties have been computed using three different micromechanical models and the homogenized creep response and its effect on the macroscopic behavior are compared. Considering the computational expenses associated with the large 3D-finite element models, investigations show that simple 2D-axisymmetric model can “closely capture” the creep behavior in such multiscale methods. Radial variations of constituent volume fractions have significant effects on stress distributions and creep strains histories. The models are beneficial to investigate the choice of material combinations and heterogeneity profiles, thereby reducing cost of materials, fabrication, and testing associated with experimental trials.