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Articles 751 - 780 of 2813

Full-Text Articles in Physical Sciences and Mathematics

Using Stable Isotopes To Quantify Nitrogen Fates In Container Plants, Sam Raimann, Greg Michalski, Michael V. Mickelbart Aug 2014

Using Stable Isotopes To Quantify Nitrogen Fates In Container Plants, Sam Raimann, Greg Michalski, Michael V. Mickelbart

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, in the agriculture field, it is not yet known the accurate amount of Nitrogen in fertilizer that plants take up. This statistic, known as the Nitrogen Use Efficiency is currently known to be within the 30-50% range (Lea-Cox and Ross, 2001). This is very important figure to know and it is a figure that can be improved, and therefore much time, energy, and resources can be saved. This research project will use concepts involving stable isotopes to examine red maple plant material and the soilless media that the plants were grown in. Three different isotope-labelled fertilizer treatments will be …

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Cosmogenic Radionuclides In Ice Cores From West Antarctica, Zhijie Chen, Thomas Edward Woodruff, Marc W. Caffee Aug 2014

Cosmogenic Radionuclides In Ice Cores From West Antarctica, Zhijie Chen, Thomas Edward Woodruff, Marc W. Caffee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cosmogenic nuclides such as 10Be and 26Al are formed in the atmosphere by cosmic rays and come down to the ground through snow which became ice in Antarctica. The concentrations of 10Be and 26Al in ice cores can reveal important information about climate change, solar activity and geomagnetic change in the past. They can also be used to date very old ice. Since there is very little 26Al in the ice, its actual concentration is poorly known and the measured results don’t agree with each other. My research is focused on the measurement of the …

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Earth History Visualization System, Xinjie Lei, James G. Ogg Aug 2014

Earth History Visualization System, Xinjie Lei, James G. Ogg

The Summer Undergraduate Research Fellowship (SURF) Symposium

Time Scale Creator (TSCreator), a geological chart generator, displays any portion of Earth history including chemo- magneto-, and other aspects. TSCreator is used by many universities, petroleum companies, and international geological surveys. In order to improve the quality of Time Scale Creator, tools were developed to provide users with more friendly graphical user interfaces (GUIs), accurate scaling of specific isotope, internationalization of data input and output, and smart depth scaling in wells to age conversion. To implement such tools, research for algorithm and common methods was basically done by searching articles online and reading posts on forums for Java developers. …

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Bayesian Calibration Tool, Sveinn Palsson, Martin Hunt, Alejandro Strachan Aug 2014

Bayesian Calibration Tool, Sveinn Palsson, Martin Hunt, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Fitting a model to data is common practice in many fields of science. The models may contain unknown parameters and often, the goal is to obtain good estimates of them. A variety of methods have been developed for this purpose. They often differ in complexity, efficiency and accuracy and some may have very limited applications. Bayesian inference methods have recently become popular for the purpose of calibrating model's parameters. The way they treat unknown quantities is completely different from any classical methods. Even though the unknown quantity is a constant, it is treated as a random variable and the desired …

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Surgical Adhesive From Mussel Mimetic Polymer, Jenna Desousa, Cori Jenkins, Jonathan Wilker Aug 2014

Surgical Adhesive From Mussel Mimetic Polymer, Jenna Desousa, Cori Jenkins, Jonathan Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Injuries involving damaged tissues are currently repaired through an invasive technique involving the use of screws, plates and sutures as support, which can damage these tissues. The biomedical field currently lacks an adhesive that can replace harmful implants. A surgical adhesive can provide a quick and easy alternative, which will minimize the risk of damaging healthy tissue in surgery. Inspiration for such materials can be found by looking at marine mussels as they are able to stick to nearly any surface, even in wet environments. Marine mussels affix themselves to different surfaces using adhesive plaques consisting of various proteins. Polymer …

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Doube-Pulse Laser-Induced Breakdown Spectroscopy Of Multi-Element Sample Containing Low- And High-Z Analytes, Patrick J. Skrodzki, Jason R. Becker, Prasoon K. Diwakar Ph. D., Sivanandan S. Harilal Ph. D., Ahmed Hassanein Ph. D. Aug 2014

Doube-Pulse Laser-Induced Breakdown Spectroscopy Of Multi-Element Sample Containing Low- And High-Z Analytes, Patrick J. Skrodzki, Jason R. Becker, Prasoon K. Diwakar Ph. D., Sivanandan S. Harilal Ph. D., Ahmed Hassanein Ph. D.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Laser-induced breakdown spectroscopy (LIBS) is a portable, remote, non-invasive analytical technique which effectively distinguishes neutral and ionic species for a range of low- to high-Z elements in a multi-element target. Subsequently, LIBS holds potential in special nuclear material (SNM) sensing and nuclear forensics requiring minimal sample preparation and detecting isotopic shifts which allows for differentiation in SNM (namely U) enrichment levels. Feasible applications include not only nonproliferation and homeland security but also nuclear fuel prospecting and industrial safeguard endorsement. Elements of higher mass with complex atomic structures, such as U, however, result in crowded emission spectra with LIBS, and characteristic …

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Three-Dimensional Deformable Pore Networks, Jack W. Conrad, Laura J Pyrak-Nolte Aug 2014

Three-Dimensional Deformable Pore Networks, Jack W. Conrad, Laura J Pyrak-Nolte

The Summer Undergraduate Research Fellowship (SURF) Symposium

Porous structures in materials play a part in many areas of research and development. A couple of examples of this are extraction of water through aquifers and oil through fracking processes. Current understanding of the small scale fluid-fluid interactions in the structure of these porous materials stops at data of the two dimensional interface between the two fluids. This experiment aimed to create three dimensional, transparent, deformable micro-models which are expected allow us to obtain three dimensional data sets of the capillary pressure–saturation–interfacial area per volume relationship. The micro-models were synthesized using a grain deposition technique. Grains were formed using …

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Evaluating Contaminants Of Emerging Concern In Commercial Biosolid-Based Fertilizers, John Hemmerling, Michael L. Mashtare, Linda S. Lee Aug 2014

Evaluating Contaminants Of Emerging Concern In Commercial Biosolid-Based Fertilizers, John Hemmerling, Michael L. Mashtare, Linda S. Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

The production and popularity of commercially available biosolid-based fertilizers are increasing because of their economic, environmental, and plant nutrition benefits, particularly in urban and suburban areas. Because biosolid-based fertilizers are derived from waste water treatment plant residuals, we hypothesized that there is the potential for micropollutants to persist in these products. Their presence would be of particular concern due to their potential impact on human and ecological health and risk of bioaccumulation. This study involves quantifying contaminants of emerging concern in three biosolid-based fertilizers, and 2 non-biosolid-based fertilizers, a composted animal manure and an organic compost. Our extraction method employed …

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Spatiotemporal Crime Analysis, James Q. Tay, Abish Malik, Sherry Towers, David Ebert Aug 2014

Spatiotemporal Crime Analysis, James Q. Tay, Abish Malik, Sherry Towers, David Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

There has been a rise in the use of visual analytic techniques to create interactive predictive environments in a range of different applications. These tools help the user sift through massive amounts of data, presenting most useful results in a visual context and enabling the person to rapidly form proactive strategies. In this paper, we present one such visual analytic environment that uses historical crime data to predict future occurrences of crimes, both geographically and temporally. Due to the complexity of this analysis, it is necessary to find an appropriate statistical method for correlative analysis of spatiotemporal data, as well …

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Building Predictive Chemistry Models, Christopher Browne, Nicolas Onofrio, Alejandro Strachan Aug 2014

Building Predictive Chemistry Models, Christopher Browne, Nicolas Onofrio, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Density Functional Theory (DFT) simulations allow for sophisticated modeling of chemical interactions, but the extreme computational cost makes it inviable for large scale applications. Molecular dynamics models, specifically ReaxFF, can model much larger simulations with greater speed, but with lesser accuracy. The accuracy of ReaxFF can be improved by comparing predictions of both methods and tuning ReaxFF’s parameters. Molecular capabilities of ReaxFF were gauged by simulating copper complexes in water over a 200 ps range, and comparing energy predictions against ReaxFF. To gauge solid state capabilities, volumetric strain was applied to simulated copper bulk and the strain response functions used …

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Reconstructing A Large-Scale Attribute-Based Social Network, Weijia Luo, Mario Ventresca Aug 2014

Reconstructing A Large-Scale Attribute-Based Social Network, Weijia Luo, Mario Ventresca

The Summer Undergraduate Research Fellowship (SURF) Symposium

An epidemic occurs when a disease rapidly infects substantially more people than expected compared to past experience of similar diseases. If an epidemic is not contained, it could turn into a pandemic, which will cause a worldwide crisis. Therefore, it is critical to determine and implement epidemic policies that are promising and effective within a short period of time. In this paper, we will develop tools that will allow us to recreate large-scale real-world social networks. Using such networks will enable us to simulate disease spread and determine critical personal and social factors that will be the key to containing …

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Identifying Candidate Genes That Affect Epidermal Development, Christina J. Smith, Longfei Wang, Michael V. Mickelbart Aug 2014

Identifying Candidate Genes That Affect Epidermal Development, Christina J. Smith, Longfei Wang, Michael V. Mickelbart

The Summer Undergraduate Research Fellowship (SURF) Symposium

The regulation of stomata, pores on the epidermis of leaves that allow for gas exchange, is an ideal target for creating a plant capable of acclimating to environmental stresses such as drought. Changes in stomatal density (SD) are correlated with different environments, but the identity of genes that act as modulators of SD are mostly unknown. To identify transcription factors that may act as modulators of SD, T-DNA mutants of candidate transcription factors identified in a genome-wide association study were characterized, and one candidate mutant displaying a phenotype was further characterized for anatomical and physiological traits. Expression of Arabidopsis thaliana …

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Improved Microrobotic Control Through Image Processing And Automated Hardware Interfacing, Archit R. Aggarwal, Wuming Jing, David J. Cappelleri Aug 2014

Improved Microrobotic Control Through Image Processing And Automated Hardware Interfacing, Archit R. Aggarwal, Wuming Jing, David J. Cappelleri

The Summer Undergraduate Research Fellowship (SURF) Symposium

Untethered submilliliter-sized robots (microrobots) are showing potential use in different industrial, manufacturing and medical applications. A particular type of these microrobots, magnetic robots, have shown improved performance in power and control capabilities compared to the other thermal and electrostatic based robots. However, the magnetic robot designs have not been assessed in a robust manner to understand the degree of control in different environments and their application feasibility. This research project seeks to develop a custom control software interface to provide a holistic tool for researchers to evaluate the microrobotic performance through advance control features. The software deliverable involved two main …

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Granular Matter: Microstructural Evolution And Mechanical Response, Aashish Ghimire, Ishan Srivastava, Timothy S. Fisher Aug 2014

Granular Matter: Microstructural Evolution And Mechanical Response, Aashish Ghimire, Ishan Srivastava, Timothy S. Fisher

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous (nano) composites, manufactured by the densification of variously sized grains, represent an important and ubiquitous class of technologically relevant materials. Typical grain sizes in such materials range from macroscopic to a few nanometers. The morphology exhibited by such disordered materials is complex and intricately connected with its thermal and electrical transport properties. It is important to quantify the geometric features of these materials and simulate the fabrication process. Additionally, granular materials exhibit complex structural and mechanical properties that crucially govern their reliability during industrial use. In this work, we simulate the densification of soft deformable grains from a low-density …

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Characterizing New Calibration Sources In Liquid Xenon Dark Matter Searches, Evan P. Bray, Rafael Lang, Sean Macmullin Aug 2014

Characterizing New Calibration Sources In Liquid Xenon Dark Matter Searches, Evan P. Bray, Rafael Lang, Sean Macmullin

The Summer Undergraduate Research Fellowship (SURF) Symposium

In order to use the XENON1T liquid xenon detector as a means for detecting dark matter, the response to nuclear and electronic recoils must be well calibrated. Electronic-recoil calibration of XENON1T will be done by using the noble gas radon-220 that emanates from a custom thorium-228 source to observe the electron recoils that its daughter elements induce in liquid xenon. A silicon PIN diode was constructed to ensure that the Th228 source does not contaminate the system with the long-lived isotopes Th228 (T1/2 of 1.9 y) or Radium-224 (T1/2 of 3.6 d). The PIN diode was fixed in a custom …

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Reliable Data Processing Enabled By Program Analysis, Tao Bao Jul 2014

Reliable Data Processing Enabled By Program Analysis, Tao Bao

Open Access Dissertations

Errors pose a serious threat to the output validity of modern data processing, which is often performed by computer programs. In scientific computation, data are collected through instruments or sensors that may be exposed to rough environmental conditions, leading to errors. Furthermore, during the computation process data may not be precisely represented due to the limited precision of the underlying machine, leading to representation errors. Computational processing of these data may hence produce unreliable output results or even faulty conclusions. We call them reliability problems. ^ We consider the reliability problems that are caused by two kinds of errors. The …

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Metal-Protein Interactions For Proteomics Applications, Keerthi B Jayasundera Jul 2014

Metal-Protein Interactions For Proteomics Applications, Keerthi B Jayasundera

Open Access Dissertations

In the quest of deciphering biological mechanisms, the understanding of proteins and their functions is a vital component. However the complexity of the proteome poses an immense challenge for analytical chemists to explore it comprehensively. Currently mass spectrometry is at the forefront of proteome analysis, providing great capabilities to couple with modern separation techniques for wide applications. One major objective of current proteomic technologies is to identify proteins of interest among high background, in particular from complex biological samples. A variety of techniques have been developed over the years to simplify protein samples, which are broadly classified as enrichment, high …

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Automated Performance Attack Discovery In Distributed System Implementations, Hyojeong Lee Jul 2014

Automated Performance Attack Discovery In Distributed System Implementations, Hyojeong Lee

Open Access Dissertations

Security and performance are critical goals for distributed systems. The increased complexity in design, incomplete expertise of developers, and limited functionality of existing testing tools often result in implementations with vulnerabilities and make the debugging process difficult and costly. The deployed vulnerabilities are often exploited by adversaries preventing the system from achieving its design goals. We refer to attacks that slow down the performance of a system as performance attacks. In the past, finding performance attacks has been a painstaking manual process that involved an expert of the target implementation. Given the cost associated with each vulnerability that occurs in …

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Paxos Based Directory Updates For Geo-Replicated Cloud Storage, Srivathsava Rangarajan Jul 2014

Paxos Based Directory Updates For Geo-Replicated Cloud Storage, Srivathsava Rangarajan

Open Access Theses

Modern cloud data stores (e.g., Spanner, Cassandra) replicate data across geographically distributed data centers for availability, redundancy and optimized latencies.^ An important class of cloud data stores involves the use of directories to track the location of individual data objects. Directory-based datastores allow flexible data placement, and the ability to adapt placement in response to changing workload dynamics. However, a key challenge is maintaining and updating the directory state when replica placement changes.^ In this thesis, we present the design and implementation of a system to address the problem of correctly updating these directories. Our system is built around JPaxos, …

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Student's Objectives And Achievement Strategies For Laborataory Work, Taylor M. Owings Jul 2014

Student's Objectives And Achievement Strategies For Laborataory Work, Taylor M. Owings

Open Access Theses

In this study, we look at students' objectives and strategies for completing their objectives for undergraduate labs. Students across two universities and three levels of chemistry were surveyed at the beginning of the semester in the fall of 2012 using an open ended survey to identify the goals students had for the course. The students responses were coded and used to create a survey that went out to the same courses at the end of the fall semester. Using data from the fall of 2012, the survey was modified and data was collected in the fall of 2013 at one …

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A Study To Estimate And Compare The Total Particulate Matter Emission Indices (Ein) Between Traditional Jet Fuel And Two Blends Of Jet A/Camelina Biofuel Used In A High By-Pass Turbofan Engine: A Case Study Of Honeywell Tfe-109 Engine, Jacob Joshua Howard Shila Jul 2014

A Study To Estimate And Compare The Total Particulate Matter Emission Indices (Ein) Between Traditional Jet Fuel And Two Blends Of Jet A/Camelina Biofuel Used In A High By-Pass Turbofan Engine: A Case Study Of Honeywell Tfe-109 Engine, Jacob Joshua Howard Shila

Open Access Theses

The aviation industry is expected to grow at an annual rate of 5% until the year 2031 according to Boeing Outlook Report of 2012. Although the aerospace manufacturers have introduced new aircraft and engines technologies to reduce the emissions generated by aircraft engines, about 15% of all aircraft in 2032 will be using the older technologies. Therefore, agencies such as the National Aeronautics and Astronautics Administration (NASA), Federal Aviation Administration (FAA), the Environmental Protection Agency (EPA) among others together with some academic institutions have been working to characterize both physical and chemical characteristics of the aircraft particulate matter emissions to …

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The Effects Of Radar On Avian Behavior: Implications For Wildlife Management At Airports, Eleanor R. Sheridan Jul 2014

The Effects Of Radar On Avian Behavior: Implications For Wildlife Management At Airports, Eleanor R. Sheridan

Open Access Theses

Airports are areas with a high availability of resources for wildlife to forage, breed, and roost. Airports also have different types of radars to assist with air traffic control as well as tracking of wildlife that could become a risk for aircraft. The effect of radar electromagnetic radiation on wildlife behavior is not well understood. The goal of this study was to determine if bird behavior is affected by radar in two contexts: static radar (e.g., surveillance radar) and approaching radar (e.g., aircraft weather radar). We used brown-headed cowbirds as a model species. In the static radar context, we performed …

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A Fesability Analysis Of A Novel Constructed Wetland Design Tool For Arusha, Tanzania, Michael R. Sheehan Jul 2014

A Fesability Analysis Of A Novel Constructed Wetland Design Tool For Arusha, Tanzania, Michael R. Sheehan

Open Access Theses

While water is a resource necessary for all life, in Tanzania alone over 20 million people who live in rural areas have no access to improved water sources. Water stress is a major concern in rural Tanzania, where annual potential evaporation can outpace precipitation by hundreds of mm per year. There is a significant need for improved access to water sources for Tanzanians living in rural regions of Arusha. To improve access to water, both water quantity and quality need to be addressed in a treatment system. Various water collection and treatment systems were compared and contrasted through the lens …

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Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer Jul 2014

Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer

Open Access Theses

Auxin transport is essential for the architecture and development of erect plants. In a network of transporters directing auxin flows, ATP-Binding Cassette (ABC) transporters are a ubiquitous family of proteins that actively transport important substrates, including auxins, across the plasma membrane. ABCB1 and ABCB19 have been shown to account for the majority of rootward auxin transport, but residual fluxes to the root tip in Arabidopsis b1b19 double mutants implies the involvement of at least one additional auxin transporter in this process. Of specific interest, the severe dwarfism seen in abcb1abcb19 is strikingly reminiscent of that seen in mutants defective in …

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Search For New Physical Phenomena Via Displaced Muon Signatures With The Cms Detector At The Lhc, Melih Solmaz Jul 2014

Search For New Physical Phenomena Via Displaced Muon Signatures With The Cms Detector At The Lhc, Melih Solmaz

Open Access Theses

The first search at the LHC for long-lived neutral particles decaying to pairs of muons by using only the muon chambers is presented. Events were collected by the CMS detector during pp collisions at √s = 8 TeV and selected from data samples corresponding to 20.5 fb-1 of integrated luminosity. No background events are expected after the full analysis selection. Expected upper limits are derived for a model which predicts a heavy scalar decaying to two long-lived particles, each of which can decay to muon pairs. Combined expected upper limits with an analysis utilizing the CMS silicon tracker …

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The Prediction Of Airborne And Structure-Borne Noise Potential For A Tire, Nicholas Sakamoto Jul 2014

The Prediction Of Airborne And Structure-Borne Noise Potential For A Tire, Nicholas Sakamoto

Open Access Theses

Tire/pavement interaction noise is a major component of both exterior pass-by noise and vehicle interior noise. The current testing methods for ranking tires from loud to quiet require expensive equipment, multiple tires, and/or long experimental set-up and run times. If a laboratory based off-vehicle test could be used to identify the airborne and structure-borne potential of a tire from its dynamic characteristics, a relative ranking of a large group of tires could be performed at relatively modest expense. This would provide a smaller sample set of tires for follow-up testing and thus save expense for automobile OEMs. The focus of …

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Effective Geoscience Pedagogy At The Undergraduate Level, Kelsey Warden Jul 2014

Effective Geoscience Pedagogy At The Undergraduate Level, Kelsey Warden

Open Access Theses

This investigation used constructivist pedagogical methods within the framework of an introductory level undergraduate geoscience course to gauge both the changes in attitude and cognition of students. Pedagogy was modified in the laboratory setting, but maintained in the lecture setting and homework. Curriculum was also maintained in the lecture, but was changed in the laboratory to emphasize the large concepts and systems stressed in Earth Science Literacy Principles. Student understanding of these concepts and systems was strengthened by factual knowledge, but recall and memorization were not the goal of the laboratory instruction. The overall goal of the study was to …

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Upscale Feedbacks Observed And Modeled During The Mesoscale Predictability Experiment, Joseph M. Woznicki Jul 2014

Upscale Feedbacks Observed And Modeled During The Mesoscale Predictability Experiment, Joseph M. Woznicki

Open Access Theses

All modes of deep convective storms perturb their local environment on temporal and spatial scales that are larger than the storm itself. Such upscale feedbacks associated with the mesoscale convective systems (MCSs) are well known; much less is known about the feedbacks associated with supercell thunderstorms that, like MCSs, represent a highly organized convective mode. Data from the Mesoscale Predictability Experiment (MPEX), in addition to CM1 model simulations, provide the means to quantify these upscale feedbacks and determine their relative influence on the subsequent predictability of the atmosphere. The 700-500 mb lapse rate (MLR), mean-layer CAPE up to 475 mb …

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Tracking Dynamic Construction Objects ---A Key Node Modeling Approach Using Color-Depth Cameras, Chenxi Yuan Jul 2014

Tracking Dynamic Construction Objects ---A Key Node Modeling Approach Using Color-Depth Cameras, Chenxi Yuan

Open Access Theses

A construction site presents a dynamic scenario. Locations of multiple objects are continuously changing and a lot of objects enter and exit the site in high frequencies. Meanwhile a construction activity consists of a large amount of stochastic operations, many uncertainties occur when making decisions. Believing that detecting, locating and tracking dynamic construction objects in real time improve construction productivity and enhance construction safety, a large number of studies have applied a variety of sensing technologies to construction sites. Hybrid image-point cloud sensing technologies, such as color-depth cameras, have a great potential in achieving real time object recognition and tracking …

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Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan Jul 2014

Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan

Open Access Theses

There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical properties.^ To …

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