48440 research outputs found
Sort by
Evaluating E-Bike Use on Carriage Roads: Patterns, Perceptions, and Policy Implications
No full textAcadia National Park’s carriage roads are a popular tourist attraction. Cycling is a common activity along the roads, with e-bikes especially gaining popularity in recent years. Our study aimed to gather information on this increase and understand cyclist behaviors. Using methods such as counting, GPS tracking, surveys and interviews, we collected data on rider tendencies, and awareness of rules and signage. Contrary to popular belief, we discovered that bikes and e-bikes largely use the carriage roads similarly. It is our recommendation that the park improve available cycling education, reevaluate the park speed limit, and work closely with Friends of Acadia and local entities to gather more information on usage patterns within the park
Building Bridges: Bicycle Associations and QPVs
No full textLyon, France has been heavily investing into its cycling infrastructure, but not in France’s low income neighborhoods, Quartiers Prioritaires de la Politique de la Ville (QPV). Organizations such as la Fédération française des Usagers de la Bicyclette (FUB), and Janus France are working to fix this. We aim to identify the barriers to cycling for QPV residents, and how to address them. To accomplish this we developed a survey, held semi-structured interviews, and did field work speaking with QPV residents to have an all encompassing scope. Our research shows the main barriers are the starting cost, security, safety, electric scooters (E-scooters), and knowledge of the programs. We propose better advertising, teaching, improved secure storage, and working with other organizations
Role of Coarse Aggregate Shape on Concrete Strength
No full textThis project aimed to measure the crack tortuosity of concrete cylinders to determine whether cubic or flat and elongated coarse aggregate was superior for concrete use. ASTM-compliant concrete cylinders consisting of one of these aggregate shapes were prepared and used in split tensile tests. Fractured surfaces were digitally reconstructed using photogrammetry and were analyzed in the 3D modeling software Blender. This project found that flat and elongated coarse aggregate samples had a 1.5% increase in crack tortuosity compared to cubic
Docks of Venice
No full textVenice faces unique challenges from aging infrastructure, rising delivery demand, and intensifying competition between watercraft. Using historical data and firsthand observations, this project evaluates and modernizes Venice’s dock infrastructure by conducting a thorough field study and tracking changes over time. Our goal was to inspect all the docks in Venice to determine its current state, evaluate its usability, and analyze our findings. To provide a basis for further advancements, our data collection and visual analysis include photographs of each dock surveyed, comparison between past and current data, and maps to represent the status of docks in the city. This project assists in recommendations that improve Venice’s delivery efficiency while maintaining its historical integrity
Vision-based Control for Soft Continuum Robots
No full textSoft continuum robots mark a revolutionary shift in robotics, thanks to their flexible mechanics and hyper-redundant degrees of freedom. They present great potential for applications including construction, industrial inspection, medical robotics, and assistive devices. However, accurately controlling these robots is challenging due to the difficulties in obtaining high-fidelity models and integrating proprioceptive sensors. To overcome these challenges, this dissertation presents novel model-free control algorithms that do not require proprioceptive sensor feedback from the robot. In place of proprioceptive feedback, the developed methods utilize purely visual information, observed on the robot’s body from an external camera, to control the robot. Moreover, these methods allow us to leverage the kinematic redundancy of continuum robots by enabling their whole-body control, unlike existing methods in the literature that focus on regulating only the end effector pose of robots. This is achieved by observing shape features along the robot’s body instead of exclusively observing features located at the robot’s end effector. Leveraging the kinematic redundancy of continuum robots enables their safe operation in cluttered and constrained environments. Additionally, a novel model-based whole-body shape control algorithm, which provides an improved transient response compared to the model-free algorithms, is presented. Detailed experimental studies are performed to characterize the control convergence, transient response, robustness, repeatability, and applicability of the proposed control algorithms
Optical fiber strain sensors and sensing systems for measuring large deformations in soft materials, demonstrated on food samples during drying
No full textThis study presents the development and advancement of an optical fiber strain sensor and sensing system tailored for real-time measurement of large strains in soft materials, demonstrated on food samples during drying processes. Recognizing the limitations of current methods, such as strain gauges for soft material strain measurement and, in particular, the inability of conventional tools like computer vision (CV) to capture subsurface strain, this research proposes a comprehensive solution comprising sensor design, readout system innovation, and a multi-strain measurement method. The work is structured around three major milestones: The first milestone involves the development of a novel optical fiber strain sensor, which was designed, fabricated, and tested on food samples as representatives of soft materials. These materials pose unique challenges due to their soft, heterogeneous, and deformable nature. The sensor integrates both intensity-based and interference-based mechanisms, making it versatile under different measurement conditions. Its soft structure, small size, and ability to capture large strain values make it suitable for embedding in soft matrices. Laboratory and in situ experiments demonstrated that the sensor can effectively measure strain up to 20% and beneath the surface, overcoming a critical limitation of surface-only techniques like computer vision. This enables detailed tracking of internal deformation dynamics, where significant strain gradients are commonly observed. The second milestone focuses on addressing the complexity and bulkiness of traditional interferometric readout systems by developing a simplified readout method based on fiber optic low coherence interferometry (FOLCI). A mathematical model was formulated to describe the sensing mechanism, and a compact readout unit was constructed using low-coherence light sources. This system eliminates the need for high-coherence lasers or bulky spectrometers and proved to be both portable and robust during experimental validation. The resulting precision of less than 0.2 µm, paired with a wide dynamic range of approximately 4 mm, makes the system ideal for in situ monitoring of large strains, where both sensitivity and compactness are critical. The third milestone explores the use of photonic inverse design to extend the sensor’s functionality for simultaneous measurement of two orthogonal strains. In soft materials like food, deformation is often anisotropic and non-uniform. Measuring orthogonal strain components at the same location is particularly challenging due to high strain gradients. To overcome this, the study introduces wavelength-dependent behavior into the sensor using a custom-designed beam splitter developed through photonic inverse design techniques. The splitter enables the sensor to resolve two orthogonal normal strains simultaneously using one sensing unit and a single readout system. Simulations confirmed the effectiveness of this approach, offering a compact and efficient alternative to using multiple, closely spaced sensors. The key contributions of this study are as follows: Contribution 1: The intensity-based and interference-based optical fiber strain sensors developed by this work enable, for the first time, to the best of our knowledge, real-time measurements of large below-the-surface strains, up to 20%, in foods during drying. The contribution of this work can be seen through the unique capabilities of the optical fiber strain sensor that not only make it applicable to food samples but also soft material samples with similar characteristics. The capabilities that make the sensor applicable as such are being able to measure large strains, having a soft structure (being appliable to soft materials), being of a small size, and so on. Furthermore, this sensor can measure the strain inside foods below the surface. Computer vision is the conventional method for food strain measurements, which only measures strain on surface. This is even more significant when we consider the large strain gradients in foods during drying which causes a considerable difference between strains on surface and inside. Contribution 2: This study is the first to experimentally report, to the best of our knowledge, the development of strain below the surface of food samples during the drying process, providing new insights into food deformation and its correlation with other drying parameters. This study involves monitoring multiple samples over time. By analyzing the strain measurements, we observed the evolution of strain behavior both spatially and temporally within the samples. Furthermore, we provide a comprehensive analysis of how variations in strain correlate with other critical drying parameters, including temperature, humidity, and their respective gradients. Contribution 3: This study presents the first implementation of a Fiber Optic Low Coherence Interferometry system for strain measurements in Food materials. The system achieves high precision (<0.2 µm) and a large dynamic range (~4 mm), making it well-suited for soft materials. Its compact, portable design and lack of sensitive components make it ideal for in situ measurements. Furthermore, this method makes the interferometry readout system of the sensor simpler and more portable. For certain testing scenarios such as food drying, in situ measurements are desired, which is not practical having a heavy, bulky, and sensitive interferometry readout system. Therefore, simplifying the readout systems through FOLCI comes as a great benefit. Additionally, FOLCI does not include any optically and electronically very sensitive devices which are preferable for in situ measurements. Contribution 4: This work is the first to apply photonic inverse design for the simultaneous measurement of two orthogonal normal strains using a single sensor. This approach can be extended to enable multiphysical measurements of various parameters This contribution can address challenges such as non-isotropic and non-uniform deformation that are among the characteristics of soft materials such foods. Placing two sensors close to each other to measure strains in different directions is not an effective solution, as significant strain gradients may exist between the two points. Moreover, this method allows us to use one readout system and one sensor to measure two strains. Contribution 5: This study introduces a comprehensive and novel platform for strain measurement, integrating multiple optimized features including a custom-designed sensor, an efficient readout system, and multidirectional measurement capability. Moreover, the platform is readily adaptable for the measurement of other physical parameters such as pressure and temperature. Since interferometric techniques, commonly used for such measurements in optical systems, are already employed within this platform, adapting it for additional sensing modalities can be achieved with minimal modification. Taken as a whole, these contributions mark significant progress in the field of strain measurement for soft materials. The sensor offers an effective, minimally invasive solution for capturing complex internal deformations, and the system’s portability and dual-strain measurement capabilities open new opportunities for real-time monitoring in various applications beyond food processing, including biological tissues and industrial soft materials
Investigating Mechanical Behavior and Manufacturing Pathways of High Entropy Alloys: A Multiscale and Multifunctional Approach
No full textHigh Entropy Alloys (HEAs), composed of multiple principal elements in near-equiatomic ratios, have emerged as a transformative class of materials due to their exceptional mechanical properties, thermal stability, and structural versatility. This thesis provides a comprehensive investigation into the multiscale strengthening mechanisms, bulk processing techniques, and small-scale deposition approaches for HEAs, contributing both foundational understanding and technological relevance. The first segment of this work explores the intrinsic sources of strength in HEAs. Through analytical modeling and experimental validation, the role of short-range order (SRO) is quantified using chemical potential relationships and Warren-Cowley parameters. The indentation size effect (ISE) is examined via nanoindentation, highlighting scale-dependent hardness trends influenced by lattice distortion and compositional complexity. Furthermore, micropillar compression studies elucidate the microscale plastic deformation mechanisms and stress-strain responses inherent to HEA systems. The second segment addresses bulk synthesis methodologies. Arc melting and mechanical alloying are investigated in detail, with processing parameters correlated to resulting microstructures and mechanical performance. These findings form a baseline for future work in additive manufacturing, where Directed Metal Laser Sintering (DMLS) and Selective Laser Melting (SLM) are proposed as emerging pathways for geometrically complex HEA components. The final segment shifts focus to small-scale and surface applications using cold spray technology. After establishing the fundamentals of cold spray mechanics, two peer-reviewed case studies on Al-6061 and Ti/Ti6Al4V coatings are embedded to benchmark process behavior. Building upon these, a proposed framework for cold spraying HEAs is outlined, emphasizing deposition challenges, feedstock design, and future characterization efforts. This integrated study advances the fundamental understanding of HEA strengthening and processing across scales, while laying groundwork for future functional applications in coatings and additively manufactured components. The thesis contributes to bridging the gap between theoretical insight and scalable materials engineering in the field of high entropy alloys
Development of a Continuous Process for the Molten Salt Pyrolysis of Polystyrene
No full textPolystyrene is a common plastic that is difficult to degrade and recycle because typical mechanical recycling techniques are ineffective. However, pyrolysis, which is a process involving the thermal degradation of carbon-based compounds using high temperatures in oxygen-free environments, can be used to depolymerize polystyrene into its monomer, styrene, which can then be recycled. The goal of this project was to design, build, and test a system that can depolymerize a continuous input of polystyrene via pyrolysis in a reactor with a molten salt reaction medium and a continuous nitrogen gas stream. A single-screw heated extruder feeding into a fluidized bed reactor with condensers for product collection was designed and constructed and determined to be an effective system based on the presence of styrene in the liquid product. The polystyrene flow rate, nitrogen gas flow rate, and reactor temperature that resulted in the highest monomer recovery were also identified
SPI-Glass: Story-Focused Augmented Reality Mobile Game
No full textSPI-Glass is an augmented reality, or AR, game designed for mobile devices, compatible with both Android and iOS. The game follows the story of the player, a member of the Student Paranormal Investigators, or SPI, as they encounter various ghosts in their quest to uncover the source of the ghosts’ unrest. Central to SPI-Glass’s gameplay are minigames, in which the player must interact with objects placed in the real world using AR, and ghost fights, which pit the player against powerful ghosts. As players progress through the story, they will encounter various ghosts, both friend and foe, each contributing to the game’s overarching narrative. Developed over nine months at Worcester Polytechnic Institute, SPI-Glass provides a novel, story-centric approach to mobile AR gaming
Thermal Homogenization of a Non-isothermal Liquid with Electrohydrodynamic Conduction Pumping Mechanism
No full textCryogenic liquids play a critical role in cooling systems for space-based electronics, including satellites, future AI-driven data centers, liquid rocket fuel management, and more. The boil off that occurs in cryogenic tanks results in a loss of valuable liquids due to localized heat gained from the surroundings. This MQP analyzed, designed, and fabricated a thermal storage tank with flexible electrohydrodynamic (EHD) conduction pumping electrodes embedded on its inner surfaces. Under a low electric field, conduction is mostly due to ions that are generated by dissociated molecules. However, under a larger electric field, dissociation exceeds the rate of recombination, producing a directional net flow. These smart, flexible EHD pumps are lightweight, low-volume, vibrationless, maintenance-free, and scalable from the macro to the microscale. The purpose of the EHD conduction pump electrodes was to effectively mix the liquid to homogenize the liquid to prove that they could avoid local boil offs