The proposed research is focused on characterizing, modeling, and fabricating granular and particulate materials across length scales. Granular and particulate materials span several length scales, from bulky solids such as ores and rocks to nano-particles and ultra-fine powders. The need for understanding the behavior of granular materials and powders cannot be overemphasized in virtue of theirscientific and technological relevance, as well as their impact on society. At one end of the scale, the large-size particles play important roles in natural disasters of great destructive potential such as landslides, debris flows, soil liquefaction, soil erosion, and earthquakes. Enhanced oil recovery is also greatly influenced by the interaction of soil or rock particles and fluid flow. At the other end of the scale, nano-particles present great potential for radically changing a large number of fields and applications and eventually, our everyday lives.
Researchers in various engineering disciplines and geology are involved in this project:
- RAJAGOPAL The focus of this research is continuum mechanics and its application to non-linear materials. A rigorous thermodynamic framework was developed to study the problem of liquefaction of soils a phenomenon in which soils lose their solid-like response and develop fluid-like behavior, with catastrophic consequences for structures built on or of such soils.
- BISCONTIN Characterization and modeling of marine clays Increasing attention is focused on the offshore environment. The global economy requires a better, wider reaching infrastructure, able to quickly distribute resources, such as oil and gas, from the point of production to the points of use. This expansion into the offshore environments requires better understanding of submarine soils behavior and soil-structure interaction to ensure the safety and performance of these new structures, often pushing the envelope of the state-of-the-art in terms of design and construction. An expanding network of telecommunication cables is also crossing the oceans floors and breakages caused by slope failures would interrupt or delay the flow of information around the world. Large submarine slides can cause tsunamis, which can be devastating for the coastal communities on the wave's path.
This project will develop an extensive database of soil behavior, specifically targeting offshore clays from the Gulf of Mexico and off the coast of West Africa. The experimental results will be obtained using a new advanced device and will characterize the response of the soils when subjected to different initial conditions, and a variety of loading paths, replicating more closely the effects of earthquakes and storm wave loading. The test results will be used for the refinement and validation of constitutive models to replicate the response of the marine clays and, ultimately, devise new, innovative and safe designs.
- SANCHEZ Unsaturated flow in deformable porous media
The unsaturated zone is the portion of the subsurface above the groundwater table. Most geotechnical and geo-environmental problems deal with the soil in unsaturated conditions. Undergraduate courses in Civil Engineering generally deal with saturated soils. However, behavior and properties of unsaturated soils are quite different from saturated ones. The aim of this project is to train researcher students in unsaturated soil mechanics and also to advance current knowledge in related problems. Some practical applications of unsaturated soils mechanics are as follows: desiccation cracks in soils; collapse compression behavior of unsaturated soils, performance of levees and dams; design of safe repositories for highly pollutant waste; behavior of swelling clays and study of remedial solutions for foundations in expansive clays.
- CHESTER This effort involves characterizing microstructures in natural and experimentally produced earthquake slip surfaces that are composed of incohesive to cohesive thin (10 mm to less than 1 mm wide) layers of comminuted rock particles that are nanometers to microns in diameter.
- MOREIRA This multidisciplinary project combines the mathematical modeling and simulation of engineering with the understanding of chemical and biological aspects of foods as affected by process parameters.
- BARRUFET Experimental work seeks to quantify the effect of chemical treatment and polymer concentration on wettability and relative permeability of sandstone and carbonate rocks.
- ARSON Permeability in Cracked Porous Rocks
The aim of this project is to model permeability in such cracked porous materials. The following questions will be raised:
- What is the influence of cracking on the pore size distribution?
- How does the geometry of the porous network control permeability?
- How is this possible to account for flow orientation and channeling in the permeability model?
- What are the assumptions needed to develop the permeability model?
- What are the relevant parameters in the permeability model?
Group B: Nano-particles and nano-fabrication—experimental investigations [top]
- UGAZ: Using Microfluidics to Study Mass Transport in Nanoparticle Suspensions Colloidal nanomaterials play a critical role in a wide variety of applications including drug delivery and biosensing, photonics, paints and coatings, and advanced heat transfer fluids. In each of these applications it is essential to understand the interparticle interactions that govern bulk properties, but the available data are often inconsistent and make it difficult to draw definitive conclusions about the origin and magnitude of these effects. The goal of this project is to overcome these difficulties by employing a microfluidic approach that allows us to intentionally destabilize colloidal suspensions so that we can directly visualize the localized aggregation phenomena. The studies performed in this REU project will help us gain a deeper understanding of the nature of these interactions so that we can harness them in ways that may enable new capabilities, such as performing controlled deposition of nanoparticle aggregates.
Localized deposition of nanoparticle aggregates inside a microchannel. Stream A: Aqueous tracer dye solution, Stream B: aqueous 1% Al2O3 solution. (a) Inlet to microchannel. (b) 2 mm downstream from inlet.
- BANERJEE Heat flux can be enhanced by theformation of nano-fins formed from nano-particles that were shown to precipitate on the heaters. This nano-fin effect was subsequently explored using transient thermal models by Molecular Dynamics (MD) techniques. The MD simulations show that in addition to thermo-physical properties. The chemical properties of the coolants are also significant. Hence, our goal is to develop a comprehensive theory of nano-scale boiling phenomena.
- For additional information: 2012 Abstract
Group C: Metals fabrication—experimental and numerical investigations [top]
- KARAMAN Shape memory alloys (SMAs) are an important class of smart materials that can produce large recoverable shape changes as a result of reversible phase transformations and are utilized in biomedical, defense, transportation and aerospace industries as actuators and superelastic materials.
- SRINIVASA Recently, we have arrived at a process of creating very hard, ductile metals by green compaction of nanopowders of metal using a process called equal channel angular extrusion. The REU student would be involved in the simulation of the process using software tools such as ABAQUS with the aim of finding optimal parameters.
Student Qualifications [top]
- US citizens or permanent residents majoring in chemistry, engineering, geology, or mathematics with an expressed interest in engineering graduate school.
- Have a 3.0 GPA or greater and have rising sophomore, junior or senior status with at least 30 semester hours, or equivalent quarter hours completed. Coursework should be applicable toward the specified study area, and not including courses that will not apply toward the degree being pursued by the applicant. GPA requirement matches current minimum requirement for graduate school admission.