Spring 2015 STEMinar Schedule
ٲٱ:1/22/15
:Fnu Shikhar
ٱ貹ٳԳ:Mechanical Engineering
վٱ:Ceramic responses under electric fields
ٰ:Materials have been broadly divided in 3 major categories: Metal, polymer and ceramics. Some common examples of ceramic are serving plates, bricks, tiles, etc. But do you know Ceramics are the core features in sensors, semiconductors, superconductors, electrical insulation, rocket body, bioengineering, heat insulations? This presentation will try to draw attention towards Ceramics, such as, how is a ceramic different from metal or polymer and why should we care about them? How are they made and how my research would help to improve some fairly old ceramic synthesis problems. We use electric field on ceramics to lower down the temperature and time required for their synthesis. Followed by this, I shall present how this new technique, named as “Flash Sintering”, has altered some of the basic properties of ceramic, what are their potential applications and the science behind them.
ٲٱ:2/5/15
Speaker:Ulyana Horodyskyj
ٱ貹ٳԳ:Geology
վٱ:Tracking supraglacial lake changes on Ngozumpa glacier, Nepal
ٰ:The formation of supraglacial (surface) lakes appears to be a catalyst for ice mass loss on debris-covered glaciers in the Himalaya. Once formed, these lakes can grow through expansion, by melting and collapsing of surrounding ice walls, and through deepening of their ice floors. As lake water volume increases, so too does the risk for glacial lake outburst floods (GLOFs). Spillway Lake, a large supraglacial base-level lake on Ngozumpa, one of Nepal’s largest and longest glaciers, has been growing since the 1980s. This research utilized time-lapse cameras, weather stations, temperature buoys, and sonar to track these changes in real time.
Oblique-view time-lapse imagery of lakes reveals that multiple drain and refill events, on the meter scale, can occur during a melt season. Less frequent overhead satellite imagery cannot account for this volume loss, stressing the importance for continued “boots on the ground” observations. Vertical temperature distribution in the subbasins of Spillway Lake reveal mostly isothermal conditions in the summer, indicating the lake is well mixed due to constant inputs of meltwater both from above ground (ice walls) and at depth, from englacial and/or subglacial channels. Lake floor melting rate is highest in the fall season, after surface melting ceases and the lake bodies have had sufficient time to accumulate heat. However, the presence of thick debris (mud and rock) on lake floors can insulate the ice from melting. Sonar imaging and 3D model construction of lake floors reveal areas prone to future deepening, which should continue to be monitored in the future.
ٲٱ:2/12/15
:Katharine Adamyk
ٱ貹ٳԳ:Mathematics
վٱ:Decryption of micronuclear precursors of somatic genes in certain ciliate species
ٰ:It has been postulated that the decryption of micronuclear precursors of somatic genes in certain ciliate species occurs by constrained reversals and block interchanges. Not all permutations are sortable by these constrained sorting operations. We find a linear time criterion for determining which permutations are sortable by constrained block interchanges. For permutations not sortable by constrained block interchanges, we find a linear time criterion for determining which permutations are the final results of attempted sorting by constrained block interchanges. The corresponding theory for constrained reversals appears more complicated and we present partial results for this operation. The constrained sorting operations suggest natural two player games. By a classical theorem of Zermelo, these games are determined that is, some player has a winning strategy. We consider the decision problem of determining which player has a winning strategy in a specific instance of a game.
ٲٱ:3/5/15
:Jordan Holquist
ٱ貹ٳԳ:Aerospace Engineering
Title:Direct generation of oxygen from electrocatalytic carbon dioxide reduction
ٰ:What is the current direction of NASA? Are they going to an asteroid? The Moon? Mars? I can’t actually answer any of these questions, but one thing is certain: no matter the destination, technology development to enable upcoming exploration is a critical need. In my presentation, I’ll briefly discuss technology development needs to advance human spaceflight and how you can get involved (read: funding sources and research opportunities that apply to all STEM disciplines).
After that, I’ll talk about my particular research: the direct generation of oxygen from electrocatalytic carbon dioxide reduction using room temperature ionic liquid catalysts. This will include an overview of the state of the art of oxygen generation/carbon dioxide reduction on board the International Space Station, a brief introduction to electrochemistry, and ionic liquid chemistry. This technology is not only critical for closing the consumables loop on board spacecraft, but also has implications for carbon neutral fuel sources, greenhouse gas emissions, and solvent chemistry.
ٲٱ:3/19/15
:Janet Tsai
ٱ貹ٳԳ:Mechanical Engineering
վٱ:The brutalist engineering center: 1965 - 2015
ٰ:As the E in STEM, Engineering is typically grouped with its related disciplines science and mathematics. Yet unlike these "pure" disciplines, engineering as we know it is relatively new, having only developed its white collar image in the early days of the Cold War, space race, and founding of NASA.
Here at CU, we have a physical reminder of this 1960s makeover of engineering our Engineering Center Building. Tracing back the conditions which led to this unique building's design and construction, we debunk some contemporary rumors and see how this concrete behemoth still affects how we teach and learn today. While it's no longer the stateoftheart beacon of space age engineering it was once intended to be, the building has successfully contained our activities for the better part of five decades. Janet will present some fascinating research on the Engineering Center, including a glimpse into the era in which it was built, and what the building means for us as researchers and educators today.
ٲٱ:4/2/15
:Daniel Feucht
ٱ貹ٳԳ:Geology
վٱ:Geophysical imaging of the Rocky Mountain Front Range: Implications for support of high topography in babyֱapp
ٰ:Have you ever wondered why Denver is the mile high city? Or why the Rocky Mountains are there at all? You probably can guess that it has something to do with plate tectonics, but as it turns out, the Rockies and the adjacent High Plains appear to be something of a special case. The origin of the southern Rocky Mountains, along with their persistence as a mountain range for more than 40 million years, is a hot topic in geology these days and several researchers at CU Boulder are leading the charge to explain this enigmatic landscape of babyֱapp that we all too often take for granted.
In my STEMinar talk I’ll present an overview of how mountains are built and maintained over geologic time, discuss how these processes relate to the mountains in our own backyard, and then present my own contribution to the Rocky Mountains puzzle in the form of a large scale magnetotelluric survey of the Rocky Mountain Front Range in babyֱapp. Magnetotellurics is a passive electromagnetic geophysical imaging technique that provides a measure of the electrical properties of the Earth at depth. By interpreting electrical properties of the crust and upper mantle in a geologic context we can estimate the distribution of temperature, melt, fluids, and altered mineral composition at depth and in turn say something about which of these mechanisms contributes to the high topography that we see today.
ٲٱ:4/9/15
:Chelsea Heveran
ٱ貹ٳԳ:Mechanical Engineering
վٱ:Bone quality is impaired in chronic kidney disease
ٰ:What makes a bone strong and tough? What about bone changes to become fragile in aging or disease? In this talk, we will take a tour from the macro to nano scales to explore what makes (and what breaks) this hierarchical and dynamic composite tissue. We will also consider how bone microstructure and material properties contribute to an overall "bone quality." Lastly, we will discuss my progress in understanding how Chronic Kidney Disease, common among the elderly, compromises bone quality to increase skeletal fragility in a large and growing clinical population.
ٲٱ:4/16/15
:Sarah Grover
ٱ貹ٳԳ:Psychology
վٱ:Building bridges: Moving towards a scientific understanding of positive cross-sex interactions in STEM and why we should care
ٰ:This talk presents social psychological theory and research to understand environmental factors that increase women's belonging in STEM. The talk will be given in 3 parts:
1. On the emergent properties of groups: How group interactions shape our self concept.
2. Present research: Two studies examining the consequences of gender composition in a small group math task for women's performance, the social cohesion they experience with their group members, and self and others' perceptions of their math ability.
3. Future directions: What are the barriers to positive crosssex contact and how can they be overcome? What are the verbal and nonverbal cues of group inclusion, and how can they be measured?
ٲٱ:4/23/15
:Navid Shervani-Tabar
ٱ貹ٳԳ:Mechanical Engineering
վٱ:Complex geometry flows: An approach to simulate the flow over obstacles which has been developed in "Multiscale modeling laboratory"
ٲٱ:4/30/15
:Graham Lau
ٱ貹ٳԳ:Geology
վٱ:Something's eating the yellow snow
ٰ:Sulfur is one of the most abundant elements in the universe and is essential for life as we know it. Characterizing the role of biology in the geochemical cycling of sulfur from regional to global scales is important for the future exploration of other worlds in our solar system and beyond. For this STEMinar, I will present my research on microbial sulfur cycling within a supraglacial sulfur spring system in the Canadian High Arctic. I'll talk about what we know and have yet to learn about the biological and abiotic processes that are responsible for cycling sulfur at this field site (and I'll also show lots of pretty pictures from my field work).