bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost-Effective Soft Actuators Using Nafion™ and Carbon Nanotube Electrodes
Authors: Wechter Benjamin , Gushue Nicholas , Reilly Luke , Rutka Maxwell , Kennedy Ryan , Mahon Jacob , Xue Wei , Trkov Mitja
Published: February 2023

We present the fabrication and characterization of a cost-effective soft actuator capable of bidirectional cantilevered bending in ambient conditions when an electric potential of 4 V is applied. The fabrication procedure is straightforward, minimizes the use of toxic chemicals, and can be executed with common lab equipment. The resulting actuator has a tri-layer construction consisting of a strip of Nafion-117 membrane sandwiched between two multi-walled carbon nanotube (MWCNT) buckypaper electrodes. The buckypaper fabrication was optimized via investigating various combinations of solvents, surfactant, MWCNT concentrations, and layered filtrations, leading to highly conductive and strong buckypaper electrodes. The resulting buckypaper electrode had an electrical resistance of about 10 Ω, which is similar to an industrially synthesized buckypaper. After saturating the actuator in an ionic liquid BMIMBF4 (C8H15BF4N2) and applying a low voltage to its electrodes, the actuator responds by bending to ward the anode during a period of 20 seconds. The results showed that our 50 mm long actuator (mounted with a cantilevered length of 40 mm) achieved a maximum tip displacement of 28 mm (strain of 0.70) and a tip blocking force of 0.98 mN.
Vision-Based Autonomous Inspection of Vertical Structures Using Unmanned Aerial Vehicle (UAV)
Authors: Gupta Ayush , Shukla Amit , Kumar Amit , Shivratri Ashok Kumar
Published: February 2023

High-rise structures like a chimney, flare stacks, storage tanks, cooling towers, electric line poles, and communication towers become a vital part of any industry and are very common in day-to-day life. These vertical structures required a proper and frequent inspection to run the industries safely and stay profitable. The inspection of the industrial structure is done in several stages, and vision-based inspection is the very initial, oldest, and simplest method to detect and locate the surface defects and anomalies. The existing traditional methods of vision-based inspections are unsafe, time-consuming, and are an extra financial burden on a company and the existing robotics inspections methods are ineffective, slow, and exhausting due to complex dynamics, structure, and weights. In this research work, we are proposing a fully autonomous visual inspection approach to inspect the vertical structure using aquadcopter. The unmanned aerial vehicle (UAV) equipped with cameras and non-contact sensors is simulated with the help of robot operating systems (ROS) and a visualization tool gazebo. To examine the developed algorithms, a simple black-colored cylindrical vertical structure is prepared in the gazebo. Here, the UAV first detects and locates the vertical structure in the image frame using a classical computer vision algorithm and will extract some desired features. The feature information coming out from the image frame will be fed into the heuristically tuned control algorithms for navigating and positioning the UAV around the vertical structure. For this work, offset control and width/radius of rotation control algorithms have been developed for positioning and trajectory tracking. Due to the image frame localization and positioning, the GPS dependency is not there, and it can operate in GPS denied the environment also. The simulation results are quite satisfying, and the overall performance of the computer vision algorithms and control algorithms is satisfactory.
Development of an Affordable and Modular 3D Printed Quadruped Robot
Authors: Schoedel Samuel E. , Fuge Alexander J. , Kalita Bhaben , Leonessa Alexander
Published: February 2023

This work presents the design and development of a biologically inspired 12 degree of freedom (DoF) quadruped robot,“Squeaky,” to use as a learning platform for research and education and as a companion robot. The design of this robot is based on and derived from the behaviors and locomotion of one of the most common pets, dogs, which exhibit a unique interaction and connection with humans. The robot design is based on three main factors: minimizing production cost by using readily available components, simplifying the manufacturing process using 3D printed parts, and streamlining onboard electronics and software using simple communication and control schemes. The use of 3D printing technology makes the robot easy to manufacture, assemble, and make design modifications to if the user requires different functionality. The main controller of the robot is a Raspberry Pi 4, which receives data from a camera and an IMU to enable various levels of autonomy. Squeaky includes a default gait generator to allow trotting locomotion with various types of motion inputs from the main controller. The simplified software and multifunctional platform of Squeaky can be useful for researchers as well as developers working in the field of quadrupeds.
Material Behavior of Hydrophobic Yb2O3 and Photocatalytic TiO2 Coatings in HVAC Water Cooling Towers: A Case Study
Authors: Al-Athel Khaled Saleh , Aldossary Turky , Akhtar Syed Sohail
Published: February 2023

An HVAC water cooling tower utilizes water in the heat transfer process. Occupational Safety and Health Administration (OSHA) mandates that HVAC systems must be cleaned twice a year to prevent pneumatic diseases, which is a costly process. In this work, hydrophobic coatings of Yb2O3, and coatings of TiO2 and TiO2+Cu are tested as potential coatings for water cooling towers. The samples were placed in water splash zones to ensure exposure to sufficient water effects. The samples were placed for 6 months in. One sample of each set was placed in the shade, while another sample was placed in sunlight to examine the different effects. For the TiO2, all samples were placed in sun-exposed areas.

During the test, the sample with the prime coating of YSZ and top coating of 50 μm Yb2O3 exhibited the best behavior compared with the rest of the samples coated with bond coating of Cr2O3. As expected, sunlight adversely affected all samples, with an increase in the number of locations with dark stains due to algae formation. In addition, the top coating of Yb2O3 improved the result. For the TiO2 coating, the addition of copper rendered better results, whereas low concentrations of several elements, such as slats, are observed in the samples with the added copper. The results are in a preliminary stage, and a complete antimicrobial analysis is needed.
Human Tolerance to Injury Under Complex Head-Neck Loading
Authors: Yoganadan Narayan , Humm John , Baisden Jamie , Varghese Vicky , Banerjee Anjishnu
Published: February 2023

Advancements in automated vehicles may position the occupant in postures different from the current, standard posture. It may affect human tolerance responses. The objective of this study was to determine the lateral bending tolerance of the head-cervical spine with initial head rotation posture using loads at the occipital condyles and lower neck and describe injuries. Using a custom loading device, head-cervical spine complexes from human cadavers were prepared with load cells at the ends. Lateral bending loads were applied to the pre-rotated specimens at 1.5 m/s. At the occipital condyles, peak axial and antero-posterior and medial-lateral shear forces were: 316–954 N, 176–254 N, and 327–508 N, and coronal, sagittal, and axial moments were:27.1–37.8 Nm, 20.9–38.4 Nm, and 9.7–19.8 Nm. At the lower neck, peak axial and shear forces were: 677–1004 N, 115–227 N, and 178–350 N, and coronal, sagittal, and axial moments were: 30–39.5 Nm, 7.6–21.3 Nm, and 5.7–13.4 Nm. Ipsilateral atlas lateral mass fractures occurred in four out of five specimens with varying joint diastasis and capsular ligament involvements. Acknowledging that the study used a small sample size, initial tolerances at the occipital condyles and lower neck were estimated using survival analysis. Injury patterns with posture variations are discussed.
Evaluation of Graded Recycled Glass/Epoxy Composite
Authors: Hegazy Ahmed H. , Abd El-Latief Mahmoud E. , Khalaf Omar , Shazly Mostafa
Published: February 2023

Composite materials, nowadays, are being used heavily in many industrial applications such as renewable energy, aerospace, and automotive. With the increased production rates, companies relying on the GFRP do not recycle it due to monetary issues using chemical or thermal methods which make it more expensive. Glass fiber recycling methods are mainly divided into mechanical, chemical, and thermal methods. Mechanical recycling involves the reduction in the size of the composite waste into different sizes and different forms such as large particles, small particles, and powder. In the present study, glass/epoxy composite wastes were mechanically recycled by shredding the bulk material. Small particles (< 1mm) and powder recyclates were used as a filler to improve the interlaminar fracture toughness of glass/epoxy composite while large particles (> 1mm) were used as a sandwich-like composite along with chopped strand fiberglass mats. For 25% concentration, samples with 4.75mm particles have improved flexural strength compared to samples with 1.25mm particles. For finer recyclates, it was found that for filler size 600μm and 5% concentration, GIIC was 85% higher than original coupons with higher flexural strength. For filler size 100μm, the performance was enhanced compared to original coupons by increasing the concentrations from 5% to 10%.
Analysis and Management of Thermal Energy Release During Quench in a Superconducting Magnet
Authors: Hasan Nusair , Ganni Venkatarao , Knudsen Peter
Published: February 2023

In low temperature superconducting (LTS) magnets built using (cryogenic) liquid cooled superconductors, such as those designed for particle accelerators and thermonuclear fusion reactors, the operating stability and quench (sudden transition from superconducting to normal state) is a complex phenomenon. In most cases, the quenched magnet is isolated from the rest of the cryogenic system and the cryogenic fluid (helium) is expelled from the cryostat via a pressure relief valve (PRV) to prevent over-pressurization. This loss of cryogenic coolant (release to atmosphere), as well as the associated stored refrigeration results in increased operational cost (to replenish the helium), and recovery time for the LTS magnet to be operational following a quench. A novel concept for energy and cryogenic inventory management during a LTS magnet quench using direct contact (fluid mixing) heat exchange in a cryogenic buffer volume has been proposed and demonstrated. Development of a semi-analytical, one-dimensional, transient model to predict the boil-off flow generated during a quench, and the subsequent energy absorption (and pressurization) in the cryogenic buffer volume is discussed. The developed model can be used as a simplified tool for process and mechanical design of such a system.
Applying Artificial Intelligence to Optimize Small-Scale Ocean Current Turbine Performance
Authors: Rouhi Shahab , Sadeqi Setare , Xiros Nikolaos , Birk Lothar , Aktosun Erdem , Ioup Juliette
Published: February 2023

A comprehensive artificial intelligence-based motor drive was developed to control the performance of a permanent magnet direct current (PMDC) motor employed as a small-scale three-bladed horizontal axis ocean current turbine. Although the conventional controller performs reasonably in a lab environment where non-linear load is absented; however, for towing tank experiments with noisy and potentially non-linear input, it is crucial to run the small-scale turbine in a robust mode. A mathematical model of a PMDC motor dynamic system is derived incorporating a fuzzy logic controller. In addition, this drive control was validated experimentally. The experimental design is discussed in detail. The system performance was tested experimentally over a wide range of operating condition to validate the fuzzy logic control robustness and effectiveness. Also, it is shown that the speed of the PMDC motor was controlled by using this fuzzy logic controller. The speed tracking shows good agreement with the reference speed regardless of the load condition.
Did S.P. Timoshenko and P. Ehrenfest Overestimate the Importance of the Fourth-Order Time Derivative in Their Theory of Beams?
Authors: Elishakoff Isaac
Published: February 2023

In this study we investigate the importance of the fourth order time derivative that appears in the equations derived by Jacques Antoine Charles Bresse in 1859, as well as in equations that were derived by Stephen Prokofievich Timoshenko and Paul Ehrenfest during years 1912–1913 and reported by Timoshenko in the 1916 book on theory of elasticity in the Russian language and then in two papers dated 1920 and 1921, in English.
Continuous Dirac Cone Evolution in Modulated Phononic Crystal
Authors: Hathcock Megan , Popa Bogdan , Wang Kon-Well
Published: February 2023

Dirac cones in the band structures of highly symmetric phononic crystal lattices have been extensively studied to produce unique acoustic phenomena. Traditionally, these interesting phenomena produced by Dirac cones occur at fixed frequencies, which cannot be adapted unless significant lattice material or geometric changes occur. To create tunable phononic structures, researchers have successfully utilized Miura-origami to modulate phononic inclusions between discrete high symmetry Bravais lattice configurations. However, the origami transformation between Bravais lattices is a continuous process, meaning that between the high symmetry Bravais lattices, the structure will transform into low symmetry lattices, which are largely unexplored. In this work, we study the perturbation of a hexagonal phononic lattice away from high symmetry. Interestingly, we see the Dirac cone at the K point of the Brillouin zone for the hexagonal lattice persist through the lattice modulation, despite loss of symmetry. Using this insight, we propose an origami phononic structure capable of continuous adjustment and refinement of Dirac cone frequency. Ultimately, we demonstrate continuous Dirac cone modulation for beam forming with the proposed origami phononic structure.
Critical Heat Flux Enhancement on Cylindrical Tubes With Circumferential Micro-Channels During Saturated Pool Boiling of Water
Authors: Hernandez Rodriguez Omar , Rahman Md Mahamudur
Published: February 2023

This work presents the experimental characterization of pool boiling heat transfer enhancement on cylindrical tubes with circumferential micro-channels using saturated water at atmospheric pressure as the working fluid. Three engineered copper tubes with 300 μm, 600 μm and 900 μm fin width and a fixed 400 μm channel width with 410 μm channel depth were machined using CNC. To compare the boiling enhancement on engineered tubes, one plain copper tube was used as the reference heater. The active heating area on the cylindrical tubes had a dimension of 9.5 mm outer diameter and 10.5 mm length. A custom-built cylindrical heater was designed using a nichrome wire coil of 30 AWG with a resistance of 19.57 Ω/inch of coil to provide joule heating to the cylindrical tubes. The electrical wire was insulated from the copper heater using a thin layer of alumina paste. The saturated pool boiling tests up to critical heat flux (CHF) were conducted at atmospheric pressure. While an approximate CHF of ∼70 W/cm2 was achieved for the plain copper tube, the cylindrical tube with microchannel geometry showed a CHF range of 131–144 W/cm2 that corresponds to 87%–100% enhancement as compared to plain cylindrical tube.
Quantifying Multiphase Flow of Aqueous Acid and Gas CO2 in Deforming Porous Media Subject to Dissolution
Authors: Rahman Rafid Musabbir , Niemus Elliott , Li Yaofa
Published: February 2023

Mineral dissolution in porous media coupled with single- or multi-phase flows is pervasive in natural and engineering systems including carbon capture and sequestration (CCS) and acid stimulation in reservoir engineering. Dissolution of minerals occurs as chemicals in the solid phase is transformed into ions in the aqueous phase, effectively modifying the physical, hydrological and geochemical properties of the solid matrix, and thus leading to the strong coupling between local dissolution rate and pore-scale flow. However, our fundamental understanding of this coupling effect at the pore level is still limited. In this work, mineral dissolution is studied using novel calcite-based porous micromodels under single- and multiphase conditions, with a focus on the interactions of mineral dissolution with pore flow. The microfluidic devices used in the experiments were fabricated in calcite using photolithography and wet etching. These surrogate porous media offer precise control over the structures and chemical properties and facilitate unobstructed and unaberrated optical access to the pore flow with μPIV methods. The preliminary results provide a unique view of the flow dynamics during mineral dissolution. Based on these pore-scale measurements, correlations between pore-scale flow and dissolution rates can be developed for several representative conditions.
3D Printing Diffraction Gratings and Fresnel Axicons
Authors: Hua Junyu , Shan Yujie , Mao Huachao
Published: February 2023

Diffractive optical elements (DOEs) are important flat optics for light phase modulation and are widely used in sensors, spectrometers, and optical designs. DOEs are fabricated mainly by nanofabrication, such as lithography, in clean rooms. This paper reports a novel 3D printing method to fabricate DOEs in minutes using low-cost 3D printers. The as-printed gratings were cleaned and drop coated to achieve a flat surface. A collimated 520nm laser beam passed through the printed samples successfully generated the designed diffraction patterns. The results validated the functionality of the gratings. The printed DOE did not degrade by UV curing, which indicates the stability of the gratings fabricated by the proposed method. Besides, another kind of DOE, Fresnel axicon, was 3D printed with different printing strategy and reasonable diffraction pattern was observed.
2D Simulation of the Placement of a Pin-Through-Hole Component and Solder Paste Melting
Authors: Rodrigues Nelson , Teixeira Inês , Carvalho Violeta , Santos Duarte , Velosa Joao , Ferreira Ana , Soares Delfim , Teixeira José , Teixeira Senhorinha
Published: February 2023

In the present work, a numerical model was developed to simulate the placement of a pin through-hole (PTH) component in an aperture containing solder paste by using Ansys Fluent® software. The work uses numerical tools to understand the physical process and the solder paste behaviour for future manufacturing improvements. The component movement was simulated with the dynamic mesh model through a user-defined function (UDF). Due to software limitations, the pin of the component is already contacting the solder paste at the start of the movement. additionally, the contact detection feature was activated to prevent the pin and PCB contact during the solder paste melting. Nevertheless, the component can still move in the domain if other forces act upon it, except in the direction where the contact would occur.

The second point to address is the meniscus formation process. This begins with the evaporation of the solder paste flux, causing a volume reduction followed by the melting of the metallic beads. The simulation allowed us to see that the melted solder surrounded the pin through capillarity and reproduced the phenomena of this solder printing process. This work allowed to follow the behaviour of both the component and the solder paste.
Design and Operational Analysis of a Photovoltaic Irrigation System
Authors: Moura Juseny , Ferreira Ana Cristina , Fernandes Costa Carlos , Barreiros Martins Luís
Published: February 2023

In the context of the worldwide high fossil fuels consumption and their environmental and geopolitical consequences, the intensive investment in renewable energy technologies such as solar-thermal, solar PV, wind and hydroelectric has emerged as unavoidable for the next decades energy transition goals. This study objective is the design and analysis of a 3 kWp solar PV system for the irrigation of a one-hectare blueberry plantation in the North of Portugal. To maximize the self-consumption energy, the best match must be achieved between the PV system production profile and the irrigation pumps consumption profile, without the use of a battery.

The PVsyst software was used to model the case study, considering the location Typical Meteorological Year data obtained by the commercial program, Meteonorm.

The simulation allowed the annual estimation of the electricity available at the inverter outlet, the exported into the National grid and the required from the grid in periods of low production. Finally, the economic feasibility of the project was evaluated, taking into account three operating scenarios.

The electricity consumption estimation is 3582 kWh/year from which 71% is expected to be provided by the PV system with an annual production of 4514 kWh. The excess energy that will be injected into the grid corresponds to 1973 kWh/year with 58% corresponding to the winter months when the irrigation system is turned off. The economic analysis concluded that the PV system viability is conditioned by the high investment costs and the adequate dynamic management of the irrigation system.
Multi-Tiered Safety for Dynamic Autonomous Warehouse Robots
Authors: Rabb Ethan , Hagberg Isaac , Murphy Alex , Butts Steven , Guizani Skander , Rogers John , Heyman Joseph L. , Crews Steven
Published: February 2023

The purpose of this project is to safely integrate robots and humans into industrial processes. The most prevalent current solution to the problem of safe integration of robots and humans is to place the robots in cages to separate the workspaces of humans and robots. The cages prevent humans from entering the robot’s workspace and prevent any contact between the two entities. However, cages present an inefficiency in the industrial process as they require additional space and do not allow a seamless integration of robots and humans. This paper proposes a multi-tiered safety system that combines vision and torque feedback safety measures that can stop robot movement. The vision safety system proposed detects foreign movement in the camera frame and stops the robot’s motion. The torque system proposed detects unexpected torques in the robot’s motors and stops the robot’s motion. The results show that both safety systems can effectively stop robot motion if an unsafe condition is detected. For the industrial process of interest, the multi-tiered safety system is expected to lay the foundation for future integration of humans and robots on the industrial process. Contributions to the academic community for this paper are a multi-tiered safety system for robots in industrial processes, a machine learning circle detection algorithm, and a novel end-of-arm-tooling (EOAT) for the industrial process of interest.
Experimental Model Development Using an Animal Brain Phantom to Study Neural Damage From Traumatic Brain Injury
Authors: Khandaker Morshed , Giri Amir , Nayak Pramod , Jarshaw Catherine , Kalay Onur Can , Karpat Fatih , Wolf Roman F.
Published: February 2023

This study aims to conduct shock tube experiments to determine neural damage from realistic non-impact blast loading using an in vitro animal test model (ellipsoid filled with simulated tissue). Traumatic Brain Injury (TBI) is caused by a sudden impact on the head that leads to the disruption of the brain’s normal function. Specific to war-related traumatic brain injuries include those which are blast-induced. Microbubbles measured in microns can form in the Cerebral Spinal Fluid (CSF) inside the skull during the blast. The “formation and dramatic collapse” of these microbubbles, a process known as cavitation, could be responsible for neural tissue damage. As a pressure wave comes into contact with a head, a shock wave is transmitted through the skull, cerebrospinal fluid, and brain tissue and causes a negative difference in pressure observed at the opposite side of impact. An event that causes a quick difference in pressure within the CSF, and comes with a directional force, may result in gas bubbles forming opposite the site of impact along with the brain-skull interface and accusing damage to the surrounding tissues. Using a rabbit brain phantom model, this research measured the impact of different ranges of shock on brain tissue. Our simplified surrogate model of the head consisted of a transparent and shatterproof spherical dummy, and a simplified phantom model of the head consists of a transparent ellipsoid with dimensions of a rabbit skull. This study made a custom design 3D printed multi-directional shock device for the blast on the brain. The first test group conducted on a simplified surrogate filled with degassed water to simulate CSF and tissue altogether. A second test group included the rabbit phantom model that was filled with degassed water. In the third blast tests, the phantom contained Sylgard gel, surrounded by a layer of degassed water, to represent brain tissue and the CSF, respectively. Blast pressure in the shock-wave tests conducted at 10–20 pounds per square inch (psi; 69–138 kPa). Pressure in the modeled CSF was determined by a pressure sensors placed at 5, 10, 15 and 20 cm distances from the shock tube film. In all tests, the pressure difference at the countercoup before and after the blast was measured using an impact sensor. This study successfully found microbubbles from the first group of test. In addition, we found decreasing pressure, impact and strain on the model in relation to distance from the blast source. The results of this study will be used in our finite element model to predict the occurrence of acute subdural hematoma due to the blast inside along the interface between various brain tissue in future study.
Fabrication of Photonic Microlasers via Microfluidic Double Emulsion
Authors: Pandit Jayanth , Kunam Bhanuprakash , Cavazos Omar , Manzo Maurizio
Published: February 2023

Fluid control at a micro-level features unique properties that can be utilized to develop devices capable of biosensing. Microfluidics is a branch of technology that deals with microfluidic channels and the fluids confined within those channels. Singular droplets can be produced when perpendicular streams of immiscible fluids intersect with the main fluid stream. This intersecting stream must be different than the main fluid stream. One fundamental way of fabricating the spheres includes using a stream of water and oil. As oil and water do not mix, the stream of oil will separate the water stream and release a singular droplet. Photonic spherical microlasers manufactured by microfluidic systems exhibit a more consistent size control and are mass-produced easily; by controlling the pressure or flow rate of both dispersed phase and continuous phase, the size of the microlaser can be precisely controlled. The use of microlasers can open several paths toward susceptible sensing systems in a variety of biomedical applications, such as cancer detection and nerve cell electric potential detection via voltage-sensitive dyes. In the past, such sensing systems have been created using different UV curable biocompatible polymers doped with laser dyes. In this work, we consider testing various configurations of immiscible fluids for the disperse and continuous phases. Not only that, but the use of double emulsion microlasers will be advantageous over single emulsion types due to a promising increase of versatility in terms of multiplexed sensing and broad applications. This new solution involves microfluidic pumps and a flow-focusing droplet generator chip with microfluidic channels fabricated with polydimethylsiloxane (PDMS) and polycarbonate. Factors like the flow rate (Q) and pressure (P) of both continuous and dispersed phases determine the size of both the core and shell of these double emulsion droplets, which are made solid-state via the UV curing process. These sensors involve the whispering-gallery-mode phenomenon, where laser light is coupled to the microlaser generating optical resonances; the incoming photons resonate because light waves propagate throughout the inner walls of the sphere. This resonance can be shifted due to external conditions that change the traveling light’s optical path. The changes in the optical spectrum are monitored by using an optical spectrometer. Such sensors have the potential to be implemented as point-of-care (POC) devices and have the prospect of growing and becoming an impactful technology in biomedical research and industry.
Requirements Elicitation: Impacts of Gamification on Variety, Novelty, and Completeness
Authors: Khade Vinayak , Masoudi Nafiseh , Acena Dane , Freeman Guo , Rai Rahul , Gorsich David , Rizzo Denise , Castanier Matt
Published: February 2023

Elicitation of requirements is a critical step in any product development process. An effective elicitation process can lead to capturing more requirements with higher degrees of novelty, variety, and completeness. Current elicitation techniques such as questionnaires, interviews, focus groups, prototyping, and brainstorming often fail to keep the stakeholders and designers engaged and may face issues, such as lack of stakeholder involvement and poor communication and collaboration. Thus, these techniques become prone to capturing ambiguous or incomplete requirements or even missing some requirements. In recent years, the application of gamification (e.g., leveraging gaming features in non-gaming contexts to create engaging and interactive user experiences) has shown promising effects in improving the motivation and participation of users in different design activities. In this paper, we present the results of a preliminary study on the impacts of gamification features on requirements elicitation activity. An experiment was conducted using two versions of a survey to elicit requirements: (1) a gamified questionnaire and (2) a non-gamified, conventional questionnaire. In both surveys, the participants were asked to generate a list of requirements. The gathered sets of requirements were then analyzed using statistical methods and compared based on three metrics: completeness, variety, and novelty. Our findings suggest that gamification positively impacts participants’ engagement, leading to a greater number of requirements. The preliminary results indicate differences in all three metrics considered here. However, there is no statistical significance in these differences to have confidence in the made observations due to the small sample size. As an initial attempt to investigate the impacts of gamification and how they could be evaluated, our study develops a preliminary understanding of the effects of gamification on requirements elicitation.
Electro-Mechanical Design of a Vacuum Chamber With Vibration and Noise Damping Capabilities on an Autonomous Undersea Vehicle
Authors: Cunha Matthew , Martel Richard , Chagnon Philip , Jackson Benjamin , McCusker James , Ma Gloria
Published: February 2023

This paper presents the development of an Autonomous Undersea Vehicle (AUV) that is capable of an acoustically stealth delivery of a payload. The payload is composed of a black box noise maker and the goal of this “stealth mission” is to minimize the amplitude of the acoustic signal emitting from the noise maker.

Various approaches are utilized to reduce the transmission of sound produced by the payload. The design incorporates a vacuum chamber to minimize the noise transmitted through air molecules surrounding the noise maker by removing the air. In addition to a vacuum chamber, both active and passive vibration damping techniques are considered as viable methods of vibration damping, further reducing the sound output. The applied passive damping system has the advantage of using simple mechanical devices, which provides significant advantages in the application to an undersea vehicle with power and space constraints. To complete the mission, a vacuum chamber with a passive vibration damping system was developed and tested by sending the payload through a sound measuring choke point which validated the efficiency of the proposed design.
CARDYNET: Deep Learning Based Navigation for Car-Like Robots in Dynamic Environments
Authors: Herr Gurtajbir , Weerakoon Lasitha , Yu Miao , Chopra Nikhil
Published: February 2023

Recently, there has been an increased interest in learning based navigation solutions for robots operating in dynamic environments. Navigation in such environments is particularly challenging due to several reasons. The decisions made by other agents may only be partially observable to the robot, and they may have conflicting objectives. The robot may have imperfect or no knowledge of other agents’ goals and planned routes. Several of the recent studies focus on differential drive robots. However, unlike the differential drive, car-like robots are subjected to additional motion constraints that make the problem harder. In this work, we first utilize an optimization based planner, namely TEB local planner, as the expert to generate high quality motion commands for a car-like robot operating in a simulated dynamic environment. We utilize these labels to train a deep neural network that learns to navigate. The deep learning based planner is further augmented with safety margins to enhance its effectiveness in collision avoidance. Finally, we experimentally evaluated the performance of our proposed method by comparing it with deployable TEB planner based local planners in the stage_ros simulator as well as real world experiments. Our method demonstrated superior performance in terms of obstacle avoidance as well as successful mission completion.
Summer Grants ‘Verão Com Ciência’, From Foundation for Science and Technology, in Portugal: Experience and Achievements
Authors: Rodrigues Nelson , Teixeira Inês , Carvalho Violeta , Abreu Inês , Gonçalves Inês , Graçoeiro Diogo , Amaral Rita , Marques João , Silva João , Ferreira Ana , Teixeira José , Alvelos Filipe , Rodrigues Cristina , Teixeira Senhorinha
Published: February 2023

Following up the call for research projects launched by the Foundation for Science and Technology (FCT) after the first pandemic event in Portugal, and bearing in mind the positive results obtained, during the summer of 2021, a new call was launched with a shorter duration.

During one month just before starting the university academic year, undergraduate students could join a research team in a research lab, and by applying a “learning by doing” approach, students experienced a research atmosphere and got involved with the main activities being developed by the research group. For engineering students, this is an opportunity to bring theory to practice, get experience, and ingress into research teamwork.

This paper presents and discusses the main achievements of this initiative, in particular, the research experience of three undergraduate students and their host research teams, from the Algoritmi center, from the School of Engineering of the University of Minho, Portugal. The students’ opinions on the developed projects were quite satisfactory and they recognized that joining this type of scholarship opens horizons, promotes an inquiring spirit, teaches research strategies and, above all, students can see their knowledge applied to engineering research and on the advancement of science.
Design of a Low-Cost Autonomous Mobile Robot for Outdoor Applications
Authors: Morris Cameron , Chauhan Vedang
Published: February 2023

In today’s world, many companies are looking for low-cost automated alternatives to industrial processes that can save time and money. Autonomous Mobile Robots (AMR’s) are an appealing new alternative to complete tasks with base chassis and interchangeable tops that allow for standardization along with multifunctionality. With improvements in motors, motor controllers, location technology, vision, and IR sensors and a variety of other sensors, many complex tasks are attainable and simpler to complete. AMR’s can also be adapted to the operating environment whether it is on a manufacturing floor or in the field exposed to different elements. Using this equipment and implementing an odometry positioning method, an AMR can be designed to travel to pre-planned coordinates and perform desired tasks at each target point. Calculations to select hardware that satisfies requirements for this application are discussed. Strategies for motion control and positioning are also shown along with their advantages and disadvantages. Other subsystems are designed and attached to the robot to allow the robot to operate with awareness of its environment. To test the AMR’s abilities, a series of experiments are designed to analyze the robot’s strengths and identify sources of error. With these tests, data is collected to compare the position calculation accuracy and analyze the speed and orientation of the robot. Based on these results, there will be suggested adjustments for future work of AMRs in this field.
Investigation of the Effect of Multiple Aging Temperature Profiles on the Constitutive Behavior of Neoprene Rubber Stored in Thermo-Oxidative Environment
Authors: Alazhary Sharif , Shaafaey Mamoon , Bahrololoumi Amir , Dargazany Roozbeh
Published: February 2023

Cross-linked polymers are widely used in various industries in the modern era. Their usage could range from medical devices to electronic components. According to their usage in harsh environments, makes them susceptible to the so-called aging phenomena. Aging is a multi-physics phenomenon that induces microstructural changes to the polymer matrix morphology. In this respect, aging can be categorized into different clusters due to the active environmental elements which cause aging. These environmental factors could be present solo or concurrently in the aging domain. Thermo-oxidative and hydrolysis mainly refer to the single aging phenomenon due to the single available environmental element which is oxygen and water respectively. On the other hand, hygrothermal and photo-oxidative aging results from the presence of oxygen plus either water or UV radiation which could be classified as a dual aging mechanism. As oxygen is one of the main environmental elements in nature, and understanding the behavior of the material during thermo-oxidative aging is very important. Accordingly, in this paper, the effects of temperature on the constitutive response of Neoprene rubber material are investigated. In fact, Neoprene is a synthetic rubber that is in high demand and widely used in many applications. Accordingly, Neoprene rubber specimens were exposed to the various thermo-oxidative aging environments in controlled laboratory conditions to study the post-aging variations in the behavior of the material. To this end, the effect of different temperature profiles on Neoprene rubber material were considered. Here, the aging temperature (T) was considered as a function of the aging time (t). In this respect, the material was subjected to different aging temperature (T) profiles which were constructed from a summation of two different step functions. The study was conducted on samples that were aged in two different temperature levels T1 and T2 for different aging durations t1, tT in three cases as follows: i) T1 = T2, ii) T1 > T2, and iii) T1 < T2. It should be noted that this approach was utilized to investigate the path dependency of thermal aging phenomena. To this end, uniaxial tensile failure, Differential Scanning Calorimetry (DSC), and cross-linking density analysis (swelling tests) were carried out on the aged and unaged samples. Both mechanical and chemical tests results were in agreement which shows that the aging of Neoprene is a non-conservative phenomenon which means that the thermo-oxidative aging of Neoprene is mainly a function of the total energy that the material had absorbed during the storage process.
Lifecycle Analysis to Improve the Sustainability of the United States Army’s Non-Tactical Vehicle Fleet
Authors: Faust Madison , Ortman Zachary , Chambers Austin , Fitzpatrick Mark , Gibson Jamir , Norris Forde , Williams Matthias , Johantges Adam D. , Kim Jae , Riser Brian , McCoy Brad , Davidson F. Todd
Published: February 2023

In recent years, the United States Army has increasingly pushed to reduce carbon dioxide emissions across all installations and operations. This push is part of a broader effort to increase the sustainability and resilience of critical defense assets, by allowing them to operate for longer periods of time, with lower environmental impacts, lower costs, and increased mission readiness. One proposed solution to help reduce the emissions of Army installations is to replace conventional internal combustion engine vehicles with fully electrified vehicles. In particular, the non-tactical vehicle fleet is of primary interest to be rapidly converted to electrified drivetrains. The primary purpose of this work is to assess whether fully electrified vehicles have the lowest life-cycle emissions when considering the specific mission requirements and infrastructure present at Army installations. This work uses lifecycle analysis methods to compare the carbon emissions for vehicles with different drivetrains, located in different electric grid regions across the United States, while driving different distances to achieve the necessary missions of their operators. These variations in how the vehicles are designed, charged, and used showcases that, while electric vehicles are the best for many scenarios, they are not always the correct choice to maximize the total reduction in carbon emissions associated with transportation services at Army installations.
Feasibility Study and Design of a Seawater Air-Conditioning System for a University Building in Fiji
Authors: Ali Muzammil , Prasad Reemal D. , Ahmed Mohammed Rafiuddin
Published: February 2023

The demand for space cooling in Fiji is increasing rapidly due to a high infrastructure development rate in the country. Seawater air conditioning is a solution to the problem of space cooling using renewable energy. In this work, a feasibility study and design of a SWAC system for a university building is carried out. The feasibility study included the cooling load calculations, the availability of seawater and the location of the building. The cooling load was estimated using CAMEL software which came to be about 509 kW. Local bathymetry charts were studied to determine the depth of ocean to be 1000 m closest to the shore at which water temperatures about 6°C can be obtained. The distance from shore at which the cold water was available was approximately 12 km. A 1:15 scaled down model of the building was constructed to find the ideal chilled water supply rate and temperature. Optimal design parameters were found to be a chilled water temperature of 7°C and a cold-water flow rate of 100L/min. A temperature of 23°C was achieved inside the building after about 15 mins. The design phase of the system included the entire buildings supply and return duct system divided among 5 AHUs. The length of the seawater suction pipeline was estimated using the depth and the distance to be around 12 km. The diameter of the seawater suction pipe was optimized using cost of pipe installation and pumping power to be 0.4m, corresponding to a pumping power of 5 kW. A heat exchanger with a capacity of 500 kW, like the total cooling load of the project was selected to transfer heat between the seawater loop and the chilled water loop. The chilled water pumping power was calculated after the design of the full chilled water supply pipeline to be 4 kW. The total cost for the implementation of the SWAC system for the Marine Sciences building was estimated to be $1.04M and the payback period was estimated to be 13.8 years compared to a conventional split-type system.
Optical Full-Field Strain Visualization on Bone
Authors: Haji Nahel , Fernandez Ryan , Haji LaRance , Jawad Badih , Vejdani Hamid , Fernandez Vernon
Published: February 2023

In this paper, we compare the response of a bone to a three-point bending load configuration. The response of the bone was analyzed using full-field digital image correlation (DIC) to measure the strains on the surface of the bone and using dial gauges to experimentally measure the deflection under loading conditions. The strain distribution and deflections at various locations along the length of the bone were used to make a comparison with standard Finite Element Analysis (FEA) to mark the differences between the two methods. The Young’s modulus was reduced in the FEA to match the deflections obtained from the three-point bending test. The full-field DIC image was then compared with the strain map obtained from FEA. Understanding the properties of bone and visualizing how bone reacts under stress can help clinicians to broaden their knowledge of fracture patterns. The knowledge gained from this study can also be used to introduce correction factors into the FEA methodology to numerically obtain comparative results.
Thin Steel Plate Surface Rust Recognition Using Processing Light Measurement for Reduction of Laser Cutting Defect False Recognition
Authors: Ishiguro Mizuki , Warisawa Shin'ichi , Narita Naoyasu , Miyoshi Hironobu , Fukui Rui
Published: February 2023

Recently, laser cutting is an essential technology for high-speed flexible sheet-metal processing. The problem of defective cutting has occurred even with appropriate cutting parameter settings. The authors have constructed a defect recognizer that uses data of light generated during thin plate cutting, and have achieved a high recognition rate. On the other hand, some misrecognition occurred, and all of the misrecognized data were found to be workpieces with rust on the surface. Therefore, as a method to reduce misrecognition, rust information should be acquired and used for defect recognition before cutting. This study aims to acquire rust information on the workpiece surface by sensing and to recognize the existence of rust in order to reduce the false recognition in thin plate cutting defect recognition. The proposed method consists of three steps. In the first step, the surface of the workpiece is irradiated by a low-power laser, and the light generated is measured using a spectrometer installed in the laser head. In the second step, the acquired spectral data is converted into a spectrogram, and the image is binarized using Otsu’s binarization method to obtain features. In the final step, a one-class support vector machine recognizes the existence of rust on a workpiece surface from the extracted features. Verification tests using a normal and two kinds of rusted surface plates data confirmed that the proposed method accurately detected the existence of rust. (Precision = 0.89, Recall = 1.0.) It was also confirmed that the low-power laser irradiation trace did not affect the spectral data of the cutting for defect recognition.