Engineering Commons^™

Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright

Faculty Journal Articles

Recent experiments show that the deformation properties of a wide range of solid materials are surprisingly similar. When slowly pushed, they deform via intermittent slips, similar to earthquakes. The statistics of these slips agree across vastly different structures and scales. A simple analytical model explains why this is the case. The model also predicts which statistical quantities are independent of the microscopic details (i.e., they are "universal"), and which ones are not. The model provides physical intuition for the deformation mechanism and new ways to organize experimental data. It also shows how to transfer results from one scale to another. …

From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen

Faculty Journal Articles

The flow of granular materials and metallic glasses is governed by strongly correlated, avalanche-like deformation. Recent comparisons focused on the scaling regimes of the small avalanches, where strong similarities were found in the two systems. Here, we investigate the regime of large avalanches by computing the temporal profile or “shape” of each one, i.e., the time derivative of the stress-time series during each avalanche. We then compare the experimental statistics and dynamics of these shapes in granular media and bulk metallic glasses. We complement the experiments with a mean-field model that predicts a critical size beyond which avalanches turn into …

Textual Comparison Of Role Model And Mentor Profiles Developed To Increase Participation Of Underrepresented Minorities In Stem, Kyle F. Trenshaw, Elif Miskioglu, Philip Asare, Nir Aish

Faculty Conference Papers and Presentations

No abstract provided.

Force Oscillations Distort Avalanche Shapes, Louis W. Mcfaul, Wendelin J. Wright, Jordan Sickle, Karin A. Dahmen

Faculty Journal Articles

Contradictory scaling behavior in experiments testing the principle of universality may be due to external oscillations. Thus, the effect of damped oscillatory external forces on slip avalanches in slowly deformed solids is simulated using a mean-field model. Akin to a resonance effect, oscillatory driving forces change the dynamics of avalanches with durations close to the oscillation period. This problem can be avoided by tuning mechanical resonance frequencies away from the range of the inverse avalanche durations. The results provide critical guidance for experimental tests for universality and a quantitative understanding of avalanche dynamics under a wide range of driving conditions.

Soil-Bentonite Slurry Trench Cutoff Wall Bore Logs, Jeffrey C. Evans

NSF Soil-Bentonite Slurry Trench Cutoff Wall Documents

Bore logs for the soil-bentonite slurry trench cutoff wall constructed in Montandon Pennsylvania.

Data Sheet For Cone Penetration Test In Soil-Bentonite Cutoff Wall, Jeffrey C. Evans

NSF Soil-Bentonite Slurry Trench Cutoff Wall Datasets

This data sheet shows the measurements taken using a cone penetration test in a soil-bentonite slurry trench cutoff wall. The testing was done following ASTM D 3441.

Stress Corrosion Cracking Resistance Of Cold-Sprayed Al 6061 Deposits Using A Newly Developed Test Fixture, Mala M. Sharma, Jeremy Schreiber, Timothy Eden, Victor Champagne

Faculty Journal Articles

The stress corrosion cracking (SCC) response of Al 6061 bulk deposits produced by high-pressure cold spray (HPCS) was investigated and compared to commercial wrought Al 6061-T6 material. Representative tensile coupons were stressed to 25%, 65% and 85% of their respective yield strength and exposed to ASTM B117 salt fog for 90 days. After exposure, the samples were mechanically tested to failure, and subsequently investigated for stress corrosion cracking via optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS). The results were compared to the wrought Al 6061-T6 properties and correlated with the observed microstructures. Wrought samples showed the initiation …

Data Sheet For Vane Shear Testing In Soil-Bentonite Cutoff Wall, Jeffrey C. Evans

NSF Soil-Bentonite Slurry Trench Cutoff Wall Datasets

This data sheet shows the measurements taken from vane shear tests in a soil-bentonite slurry trench cutoff wall. The vane obtained for the test was built in accordance to the ASTM standards of designation 2573. Due to the softness of the clay, to ensure the feasibility of acceptable torque resolution, the vane’s diameter, shaft diameter, and vane height at 100 mm, 16.5 mm, and 250 mm respectively were the largest acceptable sizes to use from the abovementioned standards.

Data Sheet For Marchetti Dilatometer In Soil-Bentonite Cutoff Wall, Jeffrey C. Evans

NSF Soil-Bentonite Slurry Trench Cutoff Wall Datasets

This data sheet shows the measurements taken using a Marchetti dilatometer in a soil-bentonite slurry trench cutoff wall for the purpose of finding the in situ lateral stresses. There are several data sets within the data sheet. Each set is labelled with the time, date, and location along the cutoff wall. The transverse orientation is perpendicular to the wall alignment and the longitudinal orientation is parallel to the wall alignment.

Measurement And Prediction Of Discharge Coefficients In Highly Compressible Pulsating Flows To Improve Egr Flow Estimation And Modeling Of Engine Flows, Indranil Brahma

Faculty Journal Articles

An assumption of constant discharge coefficient (Cd) is often made when modeling highly compressible pulsating engine flows through valves or other restrictions. Similarly, orifices and flow-nozzles used for real-time EGR flow estimation are often calibrated at a few steady-state points with one single constant Cd that minimizes the error over the selected points. This quasi-steady assumption is based on asymptotically constant Cd observed at high Reynolds number for steady (non-pulsating) flow. It has been shown in this work that this assumption is not accurate for pulsating flow, particularly at large amplitudes and low flow rates. …

Leaders Like Me, Kyle F. Trenshaw, Nir Aish, Elif Miskioglu, Philip Asare

Faculty Conference Papers and Presentations

The Workshop Program at the University of Rochester infuses collaborative learning into a variety of introductory STEM and non-STEM courses through small, weekly, peer-led problem solving sessions called "Workshops." Decades of data from these Workshops indicate that 1) African American, Black, Hispanic, and Latinx students are less likely to attend them than White and Asian students and 2) that every additional Workshop students attend improves their final course grades, even if they only miss a single Workshop out of the 13 or 14 that are offered each semester. To address this situation, the UR Workshop Program has partnered with the …

Solar Thermoelectricity Via Advanced Latent Heat Storage, Michele L. Olsen, Eric S. Toberer, David S. Ginley, Philip A. Parilla, Emily L. Warren, Aaron D. Martinez, Jonathan E. Rea, Corey Lee Hardin, Christopher J. Oshman, Nathan P. Siegel

Other Faculty Research and Publications

An aspect of the present disclosure is a system that includes a thermal valve having a first position and a second position, a heat transfer fluid, and an energy converter where, when in the first position, the thermal valve prevents the transfer of heat from the heat transfer fluid to the energy converter, and when in the second position, the thermal valve allows the transfer of heat from the heat transfer fluid to the energy converter, such that at least a portion of the heat transferred is converted to electricity by the energy converter.

Design And Evaluation Of Iot-Enabled Instrumentation For A Soil-Bentonite Slurry Trench Cutoff Wall, Jeffrey C. Evans, Alan Marchiori, Yadong Li

Faculty Journal Articles

In this work, we describe our approach and experiences bringing an instrumented soil-bentonite slurry trench cutoff wall into a modern IoT data collection and visualization pipeline. Soil-bentonite slurry trench cutoff walls have long been used to control ground water flow and contaminant transport. A Raspberry Pi computer on site periodically downloads the sensor data over a serial interface from an industrial datalogger and transmits the data wirelessly to a gateway computer located 1.3 km away using a reliable transmission protocol. The resulting time-series data is stored in a MongoDB database and data is visualized in real-time by a custom web …

Development Of Physics Based Machine Learning Algorithms, Rob Jennings

Master’s Theses

In this study, a baseball pitch was examined to try to understand its behavior, and make a predictive model of it. A baseball pitch was tested experimentally with a wind tunnel and modeled computationally with COMSOL CFD software. Five input variables (spin rate, sting angle, seam orientation: Y axis, seam orientation: Z axis, and air velocity) were controlled, with force in three axes recorded as outputs. The experimental and computational results were examined and seen to be interdependent for all input variables. Experimental and computational data were both insufficient for predicting system behavior. Experimental data collection would have required an …

Solar Powered Atmospheric Water Generation, Ben Conser

Master’s Theses

Several atmospheric water generation (AWG) system configurations were analyzed to determine the feasibility of AWG as a method to combat water stress. In order to best combat water stress, AWG must be implemented in such a way which minimizes the energetic and monetary cost of water production. Thermodynamic and economic analyses were used to compare the performance of several AWG system configurations. Metrics such as specific energy consumption (SEC) and levelized cost of water (LCOW), which measure the energetic and monetary cost of water production respectively, were used to compare each system. Using this approach, the optimal system configuration was …

Analysis And Control Of Fiber-Reinforced Elastomeric Enclosures (Frees), Soheil Habibian

Master’s Theses

While rigid robots are extensively used in various applications, they are limited in the tasks they can perform and can be unsafe in close human-robot interactions. Soft robots on the other hand surpass the capabilities of rigid robots in several ways, such as compatibility with the work environments, degrees of freedom, manufacturing costs, and safe interactions with the environment. This thesis studies the behavior of Fiber-Reinforced Elastomeric Enclosures (FREEs) as a particular type of soft pneumatic actuator that can be used in soft manipulators. A dynamic lumped-parameter model is created to simulate the motion of a single FREE under various …

Testing And Validation Framework For Closed-Loop Physiology Management Systems For Critical And Perioperative Care, Farooq M. Gessa

Master’s Theses

The research aims at developing a framework for testing systems such as closed-loop physiology management systems to ensure that they are safe and effective for use with patients. Building medical devices that are both robust and safe is a challenge. There has been a tremendous increase in modernization and innovation of various medical systems but many of these systems either fail trials or are recalled due to safety issues.

Medical operation rooms require care teams responsible for monitoring the patients and other technical surgical devices. The care process requires a balancing administration that takes care of the drugs and fluids …

Optical And Electrical Analysis Of Zno/Znte Micropillar Solar Cells, Sadia Binte Sohid

Master’s Theses

The prime focus of the energy-research community in recent times has been replacing fossil fuels with renewable energy. Therefore, photovoltaic research areas are rapidly expanding in this era. The purpose of this work is to compare three different structural ZnO/ZnTe solar cell types (planar, axial micropillar and radial micropillar). The best optical and electrical performance has been obtained by the radial junction (core-shell) ZnO/ZnTe micropillar solar cell due to its pillar structure and radial junction. The unique advantage of the radial junction micropillar is that the angle of the incident light and the carrier collection is orthogonal. Therefore, the pillar …