bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation-Based Correlation for Saved Energy in Ground Source Heat Exchangers for Middle East Region
Authors: Ahmed Khaled I. , Almashhor Abobakr , Ahmed Mohamed H. 
Published: January 2022

Abstract
Shallow geothermal energy is a renewable energy source used to reduce electric demand to produce cooling and heating of buildings. The temperature at a specific ground level is constant year-round depends on the geographic region. It can be utilized by exchanging heat in the hot weather (cooling) or cold weather (heating) using Ground Source Heat Exchangers GSHE. Many attempts have been proposed to investigate the GSHE controlling factors with a lack of interconnection effects of mutual inclusive parameters.
The current work investigates the interconnection relation of seven factors; three geometrical factors, two thermophysical factors, and two operational and environmental factors. The studied geometrical factors are the wellbore diameter and length and the tube diameter. The thermal conductivities of the wellbore grout and soil are the studied two thermophysical properties. The two studied operational and environmental factors are the circulating fluid flow rate, circulating fluid input temperature difference with the soil temperature.
A 2D axisymmetric CFD model is built to investigate the effect of the controlling parameters on the targeted output saved energy per tube length. Third-order surface response of the main output is achieved using a hybrid Box-Behnken Central-Composite design of experiments methods DOE. The Box-Behnken method concerns the mid of extremes, and the Central-Composite method concerns the rotatable variable interconnections. Although both methods are designed for second-order response surfaces, the proposed hybrid method can accurately predict third-order correlation using the Stepwise regression method on 136 design points. The nonlinear correlation is verified using another 100 random verification points, showing a root mean squared error of less than 1.5 [W/m].
The significance of each parameter on the target normalized saved energy is presented and discussed. The pipe diameter, grout conductivity, soil conductivity, and temperature difference are the most significant parameters controlling the GSHE performance. The water mass flow rate is lesser significant, while the grout diameter is insignificant. The response surface study has shown high normalized saved energy of 100 [W/m] of the pipe length for the investigated domains.
Bifurcation Characteristic and Energy Transfer of Vehicle Shimmy System Considering the Coupling of Vertical and Lateral Dynamics
Authors: Wei Heng , Lu Jian-Wei , Lu Hang-Yu , Ye Sheng-Yong 
Published: January 2022

Abstract
Since the vehicle is a complex mechanical system with many subsystems, the influence of the dynamic coupling between the subsystems of the vehicle on shimmy should be taken seriously. Therefore, a 12 degrees-of-freedom dynamic model of vehicle shimmy system with consideration of the dynamic coupling between the vertical motion and the lateral motion of the vehicle is established. In particular, the influence of the vertical load of the tire on the nonlinear cornering force is also considered. Then, the dynamic stability of the shimmy system is discussed with the help of the system eigenvalues, and the influence of the damping of the front suspension on the dynamic stability is also examined from the viewpoint of the energy transfer. On this basis, the damping of the front suspension is selected as a bifurcation parameter, and the two-dimensional center manifold of the high dimensional shimmy system is obtained by means of the center manifold theory. Finally, the Hopf bifurcation characteristic of the shimmy system is analyzed, and the analytical solutions of the shimmy system are derived for different damping of the front suspension. The results show that the increase of the damping of the front suspension is beneficial to attenuate vehicle shimmy and improve the dynamic stability of the vehicle.
Supercritical Carbon Dioxide Power Cycle Integrated With Solar Power Tower and Oxy-Combustor
Authors: Sleiti Ahmad K. , Al-Ammari Wahib A. , Gamil Ahmed I. , Al-Khawaja Mohammed 
Published: January 2022

Abstract
Power cycle that integrates solar power tower (SPT) system with direct oxy-combustion (DOC) supercritical CO2 cycle is proposed and investigated. In the SPT/DOC-sCO2 cycle (Cyc 3), the SPT works as preheater for the DOC/sCO2 system. Two more basic cycles for comparison and validation purposes are investigated including stand-alone intercooled sCO2 power cycle driven by DOC system (Cyc 1) and stand-alone basic SPT system (Cyc 2). Energy, exergy, exergoeconomic, levelized cost of electricity (LCOE) and multi-objective optimization analyses are performed for each cycle over wide range of operating pressures, temperatures and direct normal irradiance. Compared to Cyc 1 and Cyc 2, Cyc 3 has higher thermal efficiency by 6% and 2%, respectively with higher exergy efficiency and is less sensitive to cycle minimum temperature. However, the LCOE of Cyc 3 is higher due to the large capital cost of its individual CSP and DOC systems. From the optimization analyses, it is found that the decision variables of the three cycles tend toward low Pmax, higher Pmin, lower Tmax, and lower Tmin. The multi-objective optimization shows that the thermal efficiency and LCOE are 41.06% at 6.35¢/kWh for Cyc 1, 45.56% at 7.86¢/kWh for Cyc 2, and 46.65% at 8.05¢/kWh for Cyc 3.
Regional Strain Response of an Anatomically Accurate Finite Element Head Model
Authors: Rooks Tyler F. , Humm John , Baisden Jamie L. , Chancey Valeta Carol , Yoganandan Narayan 
Published: January 2022

Abstract
The need for an objective measure of injury in an area of the body that is difficult to study through experimental research methods combined with recent advancements in computational capabilities has led to a focus on development of detailed finite element models. Model development, anatomical detail, and injury metrics, however, varies widely. The purpose of this study was to benchmark the response of a newly developed anatomically accurate human brain model against the SIMon and GHBMC models and describe the predicted regional responses of the brain. The MCW-USAARL Head Injury Model (MUHIM) anatomy was developed using a neuroimaging atlas and neurosurgeon review. Material properties were obtained from literature. All three models were exercised using data from in-house laboratory tests that consisted of a helmeted head and neck mounted on a mini-sled device. Cumulative strain damage measure (CSDM) was calculated for each model using a strain threshold of 15, used in previous studies as a brain injury threshold. SIMon and GHBMC whole brain CSDM was 0.25 and 0.3 for the frontal and 0.40 and 0.3 for the lateral impact tests. Comparatively, whole brain CSDM from the MUHIM model was 0.27 for frontal tests and 0.45 for lateral tests. It is known that cognitive functions are region specific, and damage to one region may have specific neural sequela. Such regional or local metrics may explain different types of brain injuries.
Aligning Research Objectives With Student Learning Outcomes and Sustainability Objectives in Student Engineering Development Project
Authors: Al-Rawi Mohammad , Chand Praneel , Khanna Jai 
Published: January 2022

Abstract
To generate student projects that effectively inform tasks on a main project (MP), and enable students to participate in the development of a solution to a problem that affects user satisfaction with renewable energy solutions. This research contains a reflection on the mapping of project’s requirements to learning outcomes of the engineering development project (EDP) paper. Alignment to the goals and learning outcomes of the course will be discussed as well as broader implications for service learning and the potential for the project to be adapted to meet broader institutional objectives such as sustainability will be presented.
In conclusion, this paper describes the mapping of the graduate attributes and the learning outcomes in student projects to objectives of the MP, reflects on the achievement of these learning outcomes in the context of a project that fully explores all of them, and describes the service-learning potential for this type of student project.
Mathematical Modeling for Carbon Dioxide Level Within Confined Spaces
Authors: Yan Lincan , Yantek Dave S. , DeGennaro Cory R. , Fernando Rohan D. 
Published: January 2022

Abstract
Federal regulations require refuge alternatives (RAs) in underground coal mines to provide a life-sustaining environment for miners trapped underground when escape is impossible. A breathable air supply is among those requirements. For built-in-place (BIP) RAs, a borehole air supply (BAS) is commonly used to supply fresh air from the surface. It is assumed that the fresh air has an oxygen concentration of 20.9%. Federal regulations require that such a BAS must supply fresh air at 12.5 cfm or more per person to maintain the oxygen concentration between 18.5% to 23% and carbon dioxide level below the 1% limit specified. However, it is unclear whether 12.5 cfm is indeed needed to maintain this carbon dioxide level. The minimal fresh air flow (FAF) rate needed to maintain the 1% CO2 level will depend on multiple factors, including the number of people and the volume of the BIP RA. In the past, to predict the interior CO2 concentration in an occupied RA, 96-hour tests were performed using a physical human breathing simulator. However, given the infinite possibility of the combinations (number of people, size of the BIP RA), it would be impractical to fully investigate the range of parameters that can affect the CO2 concentration using physical tests.
In this paper, researchers at the National Institute for Occupational Safety and Health (NIOSH) developed a model that can predict how the %CO2 in an occupied confined space changes with time given the number of occupants and the fresh air flow (FAF) rate. The model was then compared to and validated with test data. The benchmarked model can be used to predict the %CO2 for any number of people and FAF rate without conducting a 96-hour test. The methodology used in this model can also be used to estimate other gas levels within a confined space.
Graphene Confined Polymer Thin Films Subjected to Supersonic Impact
Authors: Bowman Andrew , Roth Michael , Lawrimore William , Newman John 
Published: January 2022

Abstract
Due to their high specific penetration energy and high-strain-rate dependence, polymers are good candidates for lightweight protection against high-velocity impacts. Recent micro-impact experiments have shown enhanced abilities of polymer thin films to absorb remarkable amounts of energy during ballistic impacts. However, in situ observation of the molecular energy dissipation mechanisms is difficult or impossible, resulting in a gap in understanding. During confinement, the critically connected relationship between chain mobility, temperature, and pressure becomes more enigmatic as shock waves travel through the material. In this work, we use large-scale Molecular Dynamics (MD) simulations with reactive bond-breaking capabilities to gather insights into the nanoscale energy dissipation mechanisms of unconfined and confined polymers. Multi-layered graphene (MLG) sheets are used to create various MLG-polyethylene (PE) configurations, such as a PE with an MLG backing layer, and confined PE sandwiched between graphene. By varying the number and configurations of PE and MLG layers, the level of confinement on the PE can be increased. The resulting PE thin films, graphene films, and confined PE composites are subjected to a range of high-velocity impacts (500–7,500 m/s) to determine the amount of energy dissipation for the given material system. Unconfined PE experiences large void formation and chain pullout due to high entanglement density and low internal chain friction (small monomeric friction coefficient). With increasing levels of confinement, the energy dissipation mechanism transitions from chain disentanglement to chain scission, subsequently dissipating higher amounts of energy.
Analysis and Optimization of the Recoil-Compensated Absolute Gravimeter
Authors: Chen Yicong , Wu Kang , Wen Yi , Wang Lijun 
Published: January 2022

Abstract
The free-fall absolute gravimeter is commonly used for precise gravitational acceleration measurement. The g value is obtained through quadratic fitting of the position-time data pairs of the freely falling test mass. However, recoil vibrations are generated during the release of the test mass resulting from the movement of the center of mass of the chamber, and errors may arise from these vibrations in the measurement process. To solve the recoil vibration problem, previous researchers have developed the recoil compensation structure to achieve a basically stationary center of mass during the drop. In this paper, counterweights of a variety of masses are tested on our recoil compensated gravimeter, while recoil vibrations are recorded and analyzed accordingly. The multibody simulation indicates that compensated counterweights can significantly reduce the recoil vibration amplitude, making a more precise measurement attainable. In the experiments, accelerometers and seismometers are employed respectively in the simultaneous measurement of recoil vibrations of dropping chamber and reflector. Then all the vibration signals are analyzed and compared, and the outcome confirms the effectiveness of the gravimeter in performing high precision measurement as what is observed in the previous simulations. With a proper design of the counterweight mass, the recoil effect can be significantly reduced during the test procedure, which indicates a potential for high precision measurement.
A Meso-Scale Fretting Fatigue Simulation Method Based on Submodelling Technique
Authors: Wang Jian , Zhou Caizhi 
Published: January 2022

Abstract
This work developed a macro-microscopic coupled simulation method for fretting fatigue simulations. The crystal plasticity finite element (CPFE) mode was used to predict the hotspot of crack nucleation in fretting fatigue loading. Our model has considered the microstructure features of metals, such as the grain size, grain orientations and dislocation slips, in the fretting fatigue simulations, most of which have been ignored in previous work. And the submodel approach has been adopted in our work to overcome the size limitation and minimize the effect of boundary constrains. After calibration of material parameters, the model has been validated by the Hertz’s analytic solution based on the contact mechanics. From the results of CPFE simulations, we can accurately identify the hotspot of crack nucleation in fretting fatigue loading based on the local the equivalent plastic strain. The global model-submodel coupling method proposed in this work provides a solution for prediction of crack initiation and the crack initiation life of fretting fatigue in metals.
Learning While Playing or Playing While Learning?
Authors: Soares Filomena , Alves Anabela C. 
Published: January 2022

Abstract
This paper presents how two teachers of different courses of the third year of the Integrated Master of Industrial Engineering and Management from the University of Minho engaged students in a learning experience. By doing this, teachers considered that it is easier for the students to learn the course contents. The goal of this experience was to challenge students to acquire competencies in Process Control and Automation and Production Systems Organization I courses, in a friendly and cooperative way. Attending that students are digitally natives, curious, and easily think “out of the box”, the question is to shoot the trigger and motivate them. Achieving this, they respond with a dedicated and professional attitude, applying the acquired competencies to develop creative products and production systems. Some results of this learning experience are presented in the paper and include the concepts and outputs they produced. The student’s qualitative feedback was very positive and enthusiastic which allowed the authors to conclude that this type of challenge is worth investing in future editions of the courses. A limitation of this learning experience is the high number of students in each team.
Molecular Dynamics Simulation of Thermal Conductivity of Uranium Mononitride
Authors: Moussa Hassane Ayouba , Qingyu Wang , Ado Mohammed , Enivweru Doctor 
Published: January 2022

Abstract
The underline challenge of low thermal conductivity which is responsible for high centerline temperature in Uranium-dioxide (UO2) nuclear plant fuel type associated with the current generation of commercial reactors remains a huge concern to the nuclear power industry. Although, researchers in the nuclear industry have proposed uranium mononitride (UN) as a promising candidate for accident tolerant fuel and Generation-IV nuclear reactor fuels, unfortunately, there is still a lack of clear understanding of the point defects influence on the thermal conductivity of UN. This paper applies the reverse-NEMD method to study the effect of point defects on phonon thermal conductivity in UN perfect crystal. Experimental and simulation relevant literatures were reviewed to analyze the influence of defects on the phonon thermal conductivity of UN. The thermal conductivity of uranium mononitride increases quickly with the temperature and the phonon contribution decreases with an increase in vacancies concentration. Uranium vacancy has a detrimental effect on the phonon thermal conductivity of UN at lower vacancy concentration. Results from this research would help with the understanding and application of UN in nuclear engineering.
Mobile Solar Powered Instructional Technology Equipment for Online Teaching and Learning During COVID-19 Pandemic for Remote Community
Authors: Galindo Ronald M. , Obiso Jun-Jun A. 
Published: January 2022

Abstract
As the COVID-19 pandemic continues globally, the disruption of the traditional face-to-face classes in educational institutions is evident. In the Philippines, these educational institutions have shifted to Flexible Learning System (FLS). However, in the implementation of FLS, the teachers and the learners in the remote communities experience internet connectivity problems. This problem is minimized using mobile solar-powered instructional technology equipment for online teaching and learning activities. This equipment is designed to carry all the necessary accessories in the online delivery of FLS like television, solar panel, WiFi routers, inverters, and other power accessories. It is made of Polypropylene Random Copolymer (PPR) pipe material and is mounted on a four-wheel bicycle. Several tests were conducted to evaluate the performance of the equipment. These were the following: stress analysis, solar energy utilization test, portability assessment, connectivity speed test, and quality assessment. Results suggest that the developed equipment is ready for actual deployment in a remote community in the Philippines. With such deployment, internet connectivity problems can be minimized. As a result, the less fortunate learners can have free and reliable internet access. Moreover, a possible related future work is designing bigger mounting equipment that can carry more accessories due to its portability and mobility aspects.
Drone Assisted Targeting for Direct Fire Engagements
Authors: Batta Nathan , Williams Grant , Murphy Shane , Quantz Andrew , Pegues John , Manjunath Pratheek , Bluman James 
Published: January 2022

Abstract
The goal of the project is to develop a drone and recovery station system capable of tracking a target and round fired from a tank. Key aspects of the project include maintaining a level platform through the shot, performing accurate localization, and reacting to movements in the tank turret. The goal is for the design to be able to operate in GPS-denied and light-denied environments. After significant testing and research, the drone will be placed 10 meters behind and 20 meters above the tank muzzle and the recovery station will be placed on the rear of the tank. The drone will perform localization using visual-inertial odometry (VIO) and will react to movements in the tank turret by using a filtered IMU to send up the tank’s azimuth. All communication will be transmitted over WiFi and the video from the camera will be livestreamed on the recovery station laptop. In this semester, key areas of focus will be validating the VIO algorithm, developing a method for aligning the drone with the tank turret, establishing communication over WiFi, and then conducting final testing.
Ultimate Lightweight Design Based on Shakedown Strength and Its Application on Designing a Manned Airtight Module
Authors: Huang Songhua , Xu Yugong , Zhang Lele , Chen Geng , Zeng Fuming , Liu Feng 
Published: January 2022

Abstract
Structural lightweight optimization design is classically performed according to the elastic limit rule, which leads to an unacceptable structure weight or strength redundant to an extent. Shakedown theory is implemented in the present study to assess the load-bearing capacity of the structure. Within the shakedown load limit, failure forms of ratcheting, incremental collapse and alternate plasticity will be avoided. Moreover, the full potential of a material can be utilized by following the shakedown limit framework. Therefore, under this framework, by sacrificing some abundant loading bearing capacity, an extremely lightweight design of the structure can be reached. The current research presents a mathematical and algorithmic framework for producing extreme lightweight designs of structures that exhibit constrained shakedown loading capacity, which is an innovative means to the lightweight design and makes the optimal structure design in a relatively practical way. The hybrid genetic algorithm is introduced to obtain a more accurate global solution. The accuracy and effectiveness of the proposed numerical optimization method are validated and demonstrated by a classical problem and subsequently adopted in optimal parameter design of the connecting structure to be used in a manned airtight module. In the end, the research suggests an optimal result for both load capacity and lightweight design for the manned airtight module. And an ultimate lightweight design is given by sacrificing redundant load capacity. This study confirmed that the hybrid genetic algorithm is an effective means for determining the optimal parameter in accordance with the shakedown constraints. In addition, the results of this study support the idea that shakedown analysis should be used in the optimization design of airtight modules instead of using the traditional elastic limit rule. As the load capacity evaluates by shakedown analysis would be more factual. Moreover, this study highlights the design performance enhancements attributed to allowing redundant shakedown load capacity to exchange an ultimate reduction of material.