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Articles 140731 - 140760 of 303043

Full-Text Articles in Physical Sciences and Mathematics

57th Annual Rocky Mountain Conference On Magnetic Resonance Jul 2015

57th Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 57th annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Snowbird, Utah, July 26-31, 2015.


Open Source Electronics For Laboratory Physics, Zengqiang John Liu Jul 2015

Open Source Electronics For Laboratory Physics, Zengqiang John Liu

Physics and Astronomy Faculty Presentations

Open-source electronic devices are transforming laboratory physics education in unprecedented ways. More and more physics instructors have found that open-source electronics, such as Arduino, can provide them with wonderful teaching and learning opportunities. They can develop new laboratory activities and demonstrations, as well as exploratory and advanced projects, often involving their students. The cost is usually low. Participants of this workshop will dive right into interfacing sensors with Arduino compatible platforms. They will acquire first-hand experience constructing circuits and interfacing with sonic rangers, photogates, temperature probes, force gauges, accelerometers, magnetometers, SD cards, displays, user interfaces, and other common sensors, devices, …


Modular Classes Of Lie Groupoid Representations Up To Homotopy, Rajan Amit Mehta Jul 2015

Modular Classes Of Lie Groupoid Representations Up To Homotopy, Rajan Amit Mehta

Mathematics Sciences: Faculty Publications

We describe a construction of the modular class associated to a representation up to homotopy of a Lie groupoid. In the case of the adjoint representation up to homotopy, this class is the obstruction to the existence of a volume form, in the sense of Weinstein’s “The volume of a differentiable stack”.


Using Gis And Remote Sensing To Analyze Lake Level Rise Of Étang Saumâtre, Haiti, Helenmary M. Hotz, Alan D. Christian Jul 2015

Using Gis And Remote Sensing To Analyze Lake Level Rise Of Étang Saumâtre, Haiti, Helenmary M. Hotz, Alan D. Christian

International Journal of Geospatial and Environmental Research

Haiti is the poorest country in the western hemisphere and is beset by catastrophic events of natural and anthropogenic origins. Therefore, Haiti is vulnerable to and ill-equipped to manage these events. Since 2004, the incidence and intensity of tropical storms over the island of Hispaniola has resulted in loss of life and been the catalyst for forced migration of the population, resulting in contamination of water and health issues, i.e. cholera. Our research uses GIS and Remote Sensing to address the potential flooding hazard to population and agriculture abutting the closed basin lake Étang Saumâtre. Our analysis of Landsat imagery …


Preparing A Small Town For A Hazardous Materials Incident: An Examination Of Evacuation Routing Algorithms And Plume Models, Joseph B. Harris, Chris Gregg, T Andrew Joyner, Ingrid Luffman Jul 2015

Preparing A Small Town For A Hazardous Materials Incident: An Examination Of Evacuation Routing Algorithms And Plume Models, Joseph B. Harris, Chris Gregg, T Andrew Joyner, Ingrid Luffman

International Journal of Geospatial and Environmental Research

Evacuation and shelter in place are two common protective action measures during hazardous events that involve the release of hazardous materials. These responses are complex and require advanced planning to determine their appropriateness to reduce human exposure to hazardous materials and minimize related health risks. Evacuation and shelter in place responses were assessed for people in the town of Erwin, Tennessee, USA, a small, rural town in the mountains of Northeast Tennessee, using a release of uranium hexafluoride (UF6). The population at risk was identified using historical meteorological data and the Radiological Assessment System for Consequence Analysis tool …


Identifying Geographical Interdependency In Critical Infrastructure Systems Using Open Source Geospatial Data In Order To Model Restoration Strategies In The Aftermath Of A Large-Scale Disaster, Varun Ramachandran, Tom Shoberg, Suzanna Long, Steven Corns, Hector Carlo Jul 2015

Identifying Geographical Interdependency In Critical Infrastructure Systems Using Open Source Geospatial Data In Order To Model Restoration Strategies In The Aftermath Of A Large-Scale Disaster, Varun Ramachandran, Tom Shoberg, Suzanna Long, Steven Corns, Hector Carlo

International Journal of Geospatial and Environmental Research

In the wake of a large-scale disaster, strategies for emergency search and rescue, short-term recovery and medium- to long-term restoration are needed. While considerable effort is geared to developing strategies for the former two options, little comprehensive guidance exists on the latter. However, medium- to long-term restoration has a significant effect on local, regional and national economies and is essential to community vitality. In part, the deficit of robust strategies can be linked to the complexity in the data acquisition and limited methodologies to understand the interconnectedness of the relevant systems elements. This research utilizes infrastructure data for Supply Chain …


Revealing The Vulnerability Of Urban Communities To Flood Hazard In Tanzania: A Case Of The Dar Es Salaam City Ecosystem, Herbert Hambati, Greg Gaston Jul 2015

Revealing The Vulnerability Of Urban Communities To Flood Hazard In Tanzania: A Case Of The Dar Es Salaam City Ecosystem, Herbert Hambati, Greg Gaston

International Journal of Geospatial and Environmental Research

Losses from environmental flood hazards have escalated in recent decades, prompting a reorientation of emergency management systems away from simple post event response. There is a noticeable change in policy, with more emphasis on loss reduction through mitigation, preparedness, and recovery projects and programs. Effective mitigation of losses from flood hazards requires hazard identification, an assessment of all the hazards likely to affect a given place and people, and risk-reduction measures that are compatible across a multitude of hazards. The degree to which populations are vulnerable to flood hazards, however, is not solely dependent upon proximity to the source of …


Predicting Changes Of Rainfall Erosivity And Hillslope Erosion Risk Across Greater Sydney Region, Australia, Xihua Yang, Bofu Yu, Xiaojin Xie Jul 2015

Predicting Changes Of Rainfall Erosivity And Hillslope Erosion Risk Across Greater Sydney Region, Australia, Xihua Yang, Bofu Yu, Xiaojin Xie

International Journal of Geospatial and Environmental Research

Rainfall changes have significant effect on rainfall erosivity and hillslope erosion, but the magnitude of the impact is not well quantified because of the lack of high resolution rainfall data. Recently, the 2-km rainfall projections from regional climate models have become available for the Greater Sydney Region (GSR) at daily time step for the current (1990-2009) and future (2040-2059) periods. These climate projections allow predicting of rainfall erosivity changes and the associated hillslope erosion risk for climate change assessment and mitigation.

In this study, we developed a daily rainfall erosivity model for GSR to predict rainfall erosivity from the current …


Estimating Medically Fragile Population Exposures To Tropical Storm Surges, James L. Wilson, Eileen Neuffer Jul 2015

Estimating Medically Fragile Population Exposures To Tropical Storm Surges, James L. Wilson, Eileen Neuffer

International Journal of Geospatial and Environmental Research

Background. A particularly vulnerable sub-population is the medically fragile. The medically fragile (MF) are defined as those who have at least one chronic condition and are electrically and pharmaceutically dependent, including the need for oxygen, and require care within 48 hours. Estimates of MF populations at risk from environmental hazards are important for emergency management planning and mitigation.

Materials and Methods. The MF population is comprised of 8% of the total population under 75 years plus all those 75+ years. Zonal estimates of MF populations are obtained by clipping block level US Census populations with SLOSH basin data (SLOSH Display …


Analyzing The Relationship Of Soil Moisture And Biophysical Variables In Wet And Dry Seasons At A Rainfed And Irrigated Field In Eastern Nebraska, Eric Hunt Jul 2015

Analyzing The Relationship Of Soil Moisture And Biophysical Variables In Wet And Dry Seasons At A Rainfed And Irrigated Field In Eastern Nebraska, Eric Hunt

School of Natural Resources: Dissertations, Theses, and Student Research

Agriculture production, particularly of maize and soybeans, is a major component of Nebraska’s economy and identity. However, agricultural production in Nebraska faces increasing challenges. One of the challenges is the potential for excessive groundwater depletion due to increased demand for food and fuel from irrigated Nebraska crops and increasing risks of water stress due to climate change. Therefore, it is has become essential for a deeper understanding of the soil-plant-atmosphere continuum to help producers make more informed management decisions. One of the most important variables is soil moisture. Soil moisture is an integral part of the hydrologic cycle and an …


Urban Foraging Social Meetups In Philadelphia, Pa, Kristin G. Mcgillis Jul 2015

Urban Foraging Social Meetups In Philadelphia, Pa, Kristin G. Mcgillis

Environment and Sustainability Summer Fellows

Urban foraging is the practice in which city residents gather plants and plant parts from green spaces—such as parks, sidewalks, or yards—to use for a variety of reasons. Research on the practice is in its early stages, with key questions in need of further research, including who participates, why they participate, and how they initially engage the practice. Existing research suggests most foragers consume what they gather for food, however, many also use materials for medicinal or craft-related purposes. Foraging meet-up tours appear to be a popular way for urban dwellers to learn about and engage in this practice. This …


Yielding And Microstructure In A 2d Jammed Material Under Shear Deformation, Nathan C, Keim, Paulo E. Arratia Jul 2015

Yielding And Microstructure In A 2d Jammed Material Under Shear Deformation, Nathan C, Keim, Paulo E. Arratia

Physics

The question of how a disordered material's microstructure translates into macroscopic mechanical response is central to understanding and designing materials like pastes, foams and metallic glasses. Here, we examine a 2D soft jammed material under cyclic shear, imaging the structure of ∼5 × 104 particles. Below a certain strain amplitude, the structure becomes conserved at long times, while above, it continually rearranges. We identify the boundary between these regimes as a yield strain, defined without rheological measurement. Its value is consistent with a simultaneous but independent measurement of yielding by stress-controlled bulk rheometry. While there are virtually no irreversible …


Characterization, Dna Binding And Cleavage Activities Of New Prodigiosin And Tambjamine Analogues And Their Cu²⁺ And Zn²⁺ Complexes, Karen Chichetu Jul 2015

Characterization, Dna Binding And Cleavage Activities Of New Prodigiosin And Tambjamine Analogues And Their Cu²⁺ And Zn²⁺ Complexes, Karen Chichetu

Dissertations and Theses

Prodigiosins and tambjamines are natural compounds from bacterial and marine sources belonging to a family containing a common 4-methoxy-2,2'-bipyrrole core. These compounds have received a lot of interest due to their promising biological activities. Studies have suggested DNA as a potential therapeutic target for the natural prodigiosin and tambjamine due to their ability to facilitate oxidative DNA cleavage in the presence of Cu2+. Based on this we sought to study the metal binding activity of new prodigiosin and tambjamine analogues. A new prodigiosin analogue was synthesized and complexed with Cu2+. This revealed 1:1 complex formation between …


Classifying Political Similarity Of Twitter Users, William K. Paustian Jul 2015

Classifying Political Similarity Of Twitter Users, William K. Paustian

Computer Science Summer Fellows

The emergence of large scale social networks has led to research in approaches to classify similar users on a network. While many such approaches use data mining techniques, recent efforts have focused on measuring the similarity of users using structural properties of the underlying graph representing the network. In this paper, we identify the Twitter followers of the 2016 presidential candidates and classify them as Democrat, Republican or Bipartisan. We did this by designing a new approach to measuring structural similarity, PolRANK. PolRANK computes the similarity of a pair of users by accounting for both the number of candidates they …


Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Jacob T. Paul, Matan Peleg Jul 2015

Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Jacob T. Paul, Matan Peleg

Physics and Astronomy Summer Fellows

In our project we ran computations on a supercomputer to simulate experiments performed on highly excited atoms at μK temperatures. At μK temperatures the atoms are moving slowly so there are essentially no collisions of the atoms on the time scales at which we perform our experiments. In the absence of collisions the atoms exchange energy through long range dipole-dipole interactions. This exchange depends on the distances between and relative orientation of the atoms. The angular dependence between two atoms has recently been studied experimentally1 . We simulate experimentally accessible spatial arrangements to see if the effect of the …


Flooding In The Media, Jeremy Wheeler Jul 2015

Flooding In The Media, Jeremy Wheeler

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Communicating Flood Risks, Meg Pittenger Jul 2015

Communicating Flood Risks, Meg Pittenger

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Communicating Coastal Flood Risk & Impacts, Jeff Orrock Jul 2015

Communicating Coastal Flood Risk & Impacts, Jeff Orrock

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Flood Risk Communications - An Emergency Management Perspective, Robb Braidwood Jul 2015

Flood Risk Communications - An Emergency Management Perspective, Robb Braidwood

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Agenda, Hr Adaptation Forum Jul 2015

Agenda, Hr Adaptation Forum

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Communicating Nuisance Flooding In Hampton Roads, Burton St. John Iii, Carol Considine, Michelle Covi, Wie Yusuf, Stephanie Joannou Jul 2015

Communicating Nuisance Flooding In Hampton Roads, Burton St. John Iii, Carol Considine, Michelle Covi, Wie Yusuf, Stephanie Joannou

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


From Tidewatch To "Flood Watch", Molly Mitchell Jul 2015

From Tidewatch To "Flood Watch", Molly Mitchell

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


We Developed A Smart Phone App On Flooding And Then The Hard Work Began, Skip Stiles Jul 2015

We Developed A Smart Phone App On Flooding And Then The Hard Work Began, Skip Stiles

July 24, 2015: Communicating Frequent Flooding

No abstract provided.


Pseudocapacitors For Energy Storage, Anuradha Venkataraman Jul 2015

Pseudocapacitors For Energy Storage, Anuradha Venkataraman

Dissertations and Theses

Fluctuation in the demand for electrical power and the intermittent nature of the supply of energy from renewable sources like solar and wind have made the need for energy storage a dire necessity. Current storage technologies like batteries and supercapacitors fall short either in terms of power output or in their ability to store sufficient energy. Pseudocapacitors combine features of both and offer an alternative to stabilize the power supply. They possess high rates of charge and discharge and are capable of storing much more energy in comparison to a supercapacitor. In the quest for solutions that are economical and …


Novel Cryptographic Primitives And Protocols For Censorship Resistance, Kevin Patrick Dyer Jul 2015

Novel Cryptographic Primitives And Protocols For Censorship Resistance, Kevin Patrick Dyer

Dissertations and Theses

Internet users rely on the availability of websites and digital services to engage in political discussions, report on newsworthy events in real-time, watch videos, etc. However, sometimes those who control networks, such as governments, censor certain websites, block specific applications or throttle encrypted traffic. Understandably, when users are faced with egregious censorship, where certain websites or applications are banned, they seek reliable and efficient means to circumvent such blocks. This tension is evident in countries such as a Iran and China, where the Internet censorship infrastructure is pervasive and continues to increase in scope and effectiveness.

An arms race is …


Enabling Distributed Scientific Computing On The Campus, Derek J. Weitzel Jul 2015

Enabling Distributed Scientific Computing On The Campus, Derek J. Weitzel

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Campus research computing has evolved from many small decentralized resources, such as individual desktops, to fewer, larger centralized resources, such as clusters. This change has been necessitated by the increasing size of researcher's workloads, but this change has harmed the researcher's user experience. We propose to improve the user experience on the computational resources by creating an overlay cluster they are able to control. This overlay should transparently scale to national cyberinfrastructure as the user's demands increase.

We explore methods for improving the user experience when submitting jobs on a campus grid. To this end, we created a remote submission …


Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Matan Peleg, Jacob T. Paul Jul 2015

Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction, Matan Peleg, Jacob T. Paul

Physics and Astronomy Summer Fellows

We conducted simulations of Rydberg atoms in a magneto-optical trap using the supercomputer available on campus and the COMET supercomputer provided by the NSF. Our research focused on the angular dependence of the long range interaction between Rydberg atoms. We simulated randomly distributed atoms alligned with a magnetic and electric field. We compared the simulated interaction rates for different electric field directions.


Toward Analog Quantum Computing: Simulating Designer Atomic Systems, Jacob L. Bigelow, Veronica L. Sanford Jul 2015

Toward Analog Quantum Computing: Simulating Designer Atomic Systems, Jacob L. Bigelow, Veronica L. Sanford

Physics and Astronomy Summer Fellows

We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer …


Toward Quantum Analog Computing: Simulating Designer Atomic Systems, Veronica L. Sanford, Jacob L. Bigelow Jul 2015

Toward Quantum Analog Computing: Simulating Designer Atomic Systems, Veronica L. Sanford, Jacob L. Bigelow

Physics and Astronomy Summer Fellows

We use a magneto-optical trap to cool rubidium atoms to temperatures in the µK range. On the µs timescales of our experiment, the atoms are moving slowly enough that they appear stationary. We then excite them to a Rydberg state, where the outer electron is loosely bound. In these high energy states, the atoms can exchange energy with each other. Since the energy exchange depends on the separation and the relative orientation of the atoms, we can potentially control their interactions by controlling the spatial arrangements of the atoms. We model this system using simulations on a supercomputer …


Discrete Morse Functions, Vector Fields, And Homological Sequences On Trees, Ian B. Rand Jul 2015

Discrete Morse Functions, Vector Fields, And Homological Sequences On Trees, Ian B. Rand

Mathematics Summer Fellows

The goal of this project is to construct a discrete Morse function which induces both a unique gradient vector field and homological sequence on a given tree. After reviewing the basics of discrete Morse theory, we will show that the two standard notions of equivalence of discrete Morse functions, Forman and homological equivalence, are independent of one another. We then show through a constructive algorithm the existence of a discrete Morse function on a tree inducing a desired gradient vector field and homological sequence. After proving that our algorithm is correct, we give an example to illustrate its use.