Physical Sciences and Mathematics Commons^™

New York City’S Water Challenges: History, Politics, And Design, Jessica Crowley

Student Theses 2001-2013

New York City is one of the largest and busiest cities in the world. It is an old city that grew exponentially in size and population since founded and has since needed constant restructuring and construction. Like any large city, water was soon a resource that needed to be harnessed and brought in for health, hygiene, and many other reasons. Considering the geography of the small rocky island, water reservoirs from surrounding areas were an attractive option. Luckily this was a successful plan as the few and small reservoirs on Manhattan were not enough to maintain the enormous city that …

Saving The World’S Remaining Tigers: Panthera’S Work And The Role Of Non-Profits In Wildlife Conservation, John Byrne

Student Theses 2001-2013

This report will examine the conservation status of the tiger and measures that have been taken to protect wild populations. A discussion of its ecology and behavior is included to convey the variety of needs that are associated with establishing areas that can sustain viable populations. A look at the main threats that tigers face is crucial to understanding the conservation strategies that should be employed, and so these points will also be addressed. Focal to the report, however, will be the efforts of Panthera and its emergence onto the conservation scene as an organization that can be considered the …

Hyperbolicity Equations For Knot Complements, Christopher Martin Jacinto

Theses Digitization Project

This study analyzes Carlo Petronio's paper, An Algorithm Producing Hyperbolicity Equations for a Link Complement in S³. Using the figure eight knot as an example, we will explain how Petronio's algorithm was able to decompose the knot complement of an alternating knot into tetrahedra. Then, using the vertex invariants of these tetrahedra, we will explain how Petronio was able to create hyperbolicity equations.

Adsorption Of Tcnqh-Functionalized Quinonoid Zwitterions On Gold And Graphene: Evidence For Dominant Intermolecular Interactions+, Lingmei Kong, Lucie Routaboul, Pierre Braunstein, Hong-Gi Park, Jaewu Choi, John P. Colon Cordova, E Vega, Luis G. Rosa, Bernard Doudin, Peter A. Dowben

Peter Dowben Publications

We experimentally investigate the electronic structure of the strongly dipolar, quinonoid-type molecule obtained by TCNQH-functionalization (TCNQH = (NC)₂CC₆H₄CH(CN)₂) of (6Z)-4-(butylamino)-6-(butyliminio)- 3-oxocyclohexa-1,4-dien-1-olate C₆H₂(...NHR)₂(...O)₂ (where R = n-C₄H₉) to be very similar after deposition from solution on either graphene or gold substrates. These zwitterion adsorbate thin films form structures that are distinct from those formed by related quinonoid molecules previously studied. We argue that adsorbate–adsorbate interactions dominate and lead to a Stranski–Krastanov ‘island growth’ mechanism.

The Debye Temperature For Hydrothermally Grown Tho2 Single Crystals, Tony D. Kelly, James C. Petrosky, John W. Mcclory, Timothy Zens, David Turner, J Matthew Mann, Joseph W. Kolis, Juan A. Colon Santana, Peter A. Dowben

Peter Dowben Publications

The electronic properties of ThO₂ single crystals were studied using x-ray photoemission spectroscopy (XPS). The XPS results show that the Th 4f core level is in an oxidation state that is consistent with that expected for Th in ThO₂. The effective Debye temperature is estimated from the temperature dependent photoemission intensities of the Th 4f core level over the temperature range of 290 to 360 K. A Debye temperature of 468±32 K has been determined.

The View From Ventress - 2013, University Of Mississippi. College Of Liberal Arts

Liberal Arts Newsletters

Cover Story: College Commits to Service

Quantum Cryptography, Razvan Augustin Dinu

Theses Digitization Project

This study builds a case for using a quantum computer for solving cryptographic problems. It looks at the quantum turing machine concept, explores why use quantum computers and presents Deutsch's problem which allows one to select from amongst the parallel paths a quantum computer calculates.

Enumeration And Symmetric Presentations Of Groups, With Music Theory Applications, Jesse Graham Train

Theses Digitization Project

The purpose of this project is to construct groups as finite homomorphic images of infinite semi-direct products. In particular, we will construct certain classical groups and subgroups of sporadic groups, as well groups with applications to the field of music theory.

Whitney's 2-Isomorphism Theorem For Hypergraphs, Eric Anthony Taylor

Theses Digitization Project

This study will examine a fundamental theorem from graph theory: Whitney's 2-Isomorphism Theorem. Whitney's 2-Isomorphism theorem characterizes when two graphs have isomorphic cycle matroids.

Gradeboard: A Cloud-Based Solution For A Student Grading System, Manoj Kulkarni

Theses Digitization Project

The purpose of the GradeBoard application is to develop a mobile application as a front end to interact with data stored in a cloud-based system. It leverages cloud computing features such as auto-scaling, load-balancing and NoSQL data stores. The GradeBoard application helps instructors keep track of student activities and gives students an opportunity to know how they are performing by comparing their grades with other students through a game-like leader board interface, thus creating a competitive environment in the class. Contains source code.

Queuepay.Com: Building A System For Cardholders' Transaction Security, Jose Ramon Gonzalez

Theses Digitization Project

The purpose of this project was to apply the skills learned in the MBA program to help develop a solution to a problem that costs billions of dollars every year in fraudulent related losses arising from the use of payment cards such as debit cards, credit cards, charge cards or prepaid cards. The project analyzes the industry of payment cards, the emergence of the problem, and builds a prototype that addresses the problem. Queuepay.com is designed to provide services to its cardholders that will significantly reduce the risk of fraud.

California State University, San Bernardino Managing Cloud Computing Resources With Cloudstack Using Kvm Hypervisor, Ian Buckner Jacobs

Theses Digitization Project

The purpose of this project is to present a detailed description of the Enterprise Cloud Computing implementation of CloudStack using KVM. It will explain the purpose and features of the system, the interfaces of the system, what the system will do, and the constraints or limitations implementing CloudStack with the hardware available for this study.

Gradebadge: Development Of A Cloud-Based Reward Application, Erwin Toni Soekianto

Theses Digitization Project

The purpose of this project is to investigate the use of cloud-based services to deliver cutting edge applications. For this purpose, a prototype of a reward application using badges, called Gradebadge, was developed to illustrate and explore this emerging paradigm.

The Complexity Of Linear Algebra, Leann Kay Christensen

Theses Digitization Project

This study examines the complexity of linear algebra. Complexity means how much work, or the number of calculations or time it takes to perform a task. As linear algebra is used more and more in different fields, it becomes useful to study ways of reducing the amount of work required to complete basic procedures.

A Study Of Finite Symmetrical Groups, Patrick Kevin Martinez

Theses Digitization Project

This study discovered several important groups that involve the classical and sporadic groups. These groups appeared as finite homomorphic images of the progenitors 3*8 : PGL₂(7), 2*¹⁴ : L₃ (2), 5*³ : S₃ and 7*2 : m S₃.

Behavior Of Solutions For Bernoulli Initial-Value Problems, Carlos Marcelo Sardan

Theses Digitization Project

The purpose of this project is to investigate blow-up properties of solutions for specific initial-value problems that involve Bernoulli Ordinary Differential Equations (ODE's). The objective is to find conditions on the coefficients and on the initial-values that lead to unbounded growth of solutions in finite time.

Fiducial-Free Alignment Verification Techniques For Intracranial Radiosurgery, Kenneth Matthew Williams

Theses Digitization Project

This thesis serves as the basis for a method using image registration to automate patient alignment in an effort to eliminate the dependency on the fiducial markers as well as improve the accuracy efficiency of the alignment process. Proton beams are an external beam modality of radiation therapy that can be used effectively for radiosurgical applications due to the dosimetry advantage of the Bragg peak. The Bragg peak is a phenomenon exploited by proton beam therapy to concentrate the effect of the beams on the tumor while minimizing damage to critical structures and other health tissues within the patient.

Alternative Hull Detection Techniques For Preprocessing In Proton Computed Tomography Reconstruction, Blake Edward Schultze

Theses Digitization Project

The purpose of this study was to develop computationally efficient hull detection techniques appropriate for image reconstruction using sparse matrices. The hull detection techniques investigated were space carving (SC), modified space carving (MSC), and space modeling (SM) and these were compared to the cone-beam version of filtered back projection (FBP) algorithm in terms of their computation time and the quality of the object hull they produced.

Propagation Of Interval And Probabilistic Uncertainty In Cyberinfrastructure-Related Data Processing And Data Fusion, Christian Servin

Open Access Theses & Dissertations

Data uncertainty affects the results of data processing. So, it is necessary to find out how the data uncertainty propagates into the uncertainty of the results of data processing. This problem is especially important when cyberinfrastructure enables us to process large amounts of heterogeneous data. In the ideal world, we should have an accurate description of data uncertainty, and well-justified efficient algorithms to propagate this uncertainty. In practice, we are often not yet in this ideal situation: the description of uncertainty is often only approximate, and the algorithms for uncertainty propagation are often not well-justified and not very computationally efficient. …

An Evaluation Of The Cerro Process As An Efficient Ro Concentrate Management System, Guillermo Guadalupe Delgado

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) Process is a new method to treat RO concentrate and brackish water with high concentrations of silica and calcium sulfate. Prior investigations have shown that the CERRO process can treat this kind of water without fouling or scaling the membranes, but the main factors that allow the system to operate in such conditions were not studied. The research presented here is an evaluation of the CERRO process as an efficient RO concentrate management system. The parameters of operation of the system were evaluated and improved. The precipitation of calcium sulfate was identified as …

Virtual Machine Workloads: The Case For New Nas Benchmarks, Vasily Tarasov, Dean Hildebrand, Geoffrey H. Kuenning, Erez Zadok

All HMC Faculty Publications and Research

Network Attached Storage (NAS) and Virtual Machines (VMs) are widely used in data centers thanks to their manageability, scalability, and ability to consolidate resources. But the shift from physical to virtual clients drastically changes the I/O workloads to seen on NAS servers, due to guest file system encapsulation in virtual disk images and the multiplexing of request streams from different VMs. Unfortunately, current NAS workload generators and benchmarks produce workloads typical to physical machines.

This paper makes two contributions. First, we studied the extent to which virtualization is changing existing NAS workloads. We observed significant changes, including the disappearance of …

Impact Of Varied Low Resolution Phantoms On Intensity Modulated Proton Therapy Dose Distributions, Aarohi Shyam Padhye

Theses Digitization Project

The primary purpose of this thesis is to discuss the usefulness of image segmentation techniques in creating accurate proton dose distribution plans. The calculation of the proton dose distribution has to take into account the material (tissue, bone, brain) in the treatment area of the patients body.

Social Aggregation In Pea Aphids: Experiment And Random Walk Modeling, Christa Nilsen, John Paige, Olivia Warner, Benjamin Mayhew, Ryan Sutley, Matthew Lam '15, Andrew J. Bernoff, Chad M. Topaz

All HMC Faculty Publications and Research

From bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. An ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. We model aggregation of the pea aphid, Acyrthosiphon pisum. Specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to deduce individual-level rules. We observe that each aphid transitions stochastically between a moving and a stationary state. Moving aphids follow a correlated random walk. …

Search For Spin-Polarized Photoemission From Gaas Using Light With Orbital Angular Momentum, Nathan B. Clayburn, J. L. Mccarter, J. M. Dreiling, M. Poelker, D. M. Ryan, Timothy J. Gay

Timothy J. Gay Publications

Laser light with photon energy near the band gap of GaAs and in Laguerre-Gaussian modes with different amounts of orbital angular momentum was used to produce photoemission from unstrained GaAs. The degree of electron spin polarization was measured using a micro-Mott polarimeter and found to be consistent with zero with an upper limit of ∼3% for light with up to ±5h of orbital angular momentum. In contrast, the degree of spin polarization of 32.3 ± 1.4% using circularly polarized laser light at the as the same wavelength, which is typical for bulk GaAs photocathodes.

Threshold Alignment Reversal And Circularly Polarized Fluorescence In Rotationally Resolved H2, Jack W. Maseberg, Klaus Bartschat, Timothy J. Gay

Timothy J. Gay Publications

Using H₂ and D₂ targets, we have measured the polarization of Fulcher-band fluorescence resulting from spin-polarized electron-impact excitation of vibrationally and rotationally resolved d ³Π_u→ a ³ ∑_g⁺ transitions for incident electron energies from 14.3 to 28.5 eV. Near threshold, the linear polarization P₁ descends from positive values through zero to negative values, indicating a dynamic production of M_N = 0 states. The circular polarization P₃ is measured to be nonzero, indicating the orientation of rotationally resolved molecular states. For Q-branch transitions, P₃ is consistent with theory based …

Compact Inline Optical Electron Polarimeter, Munir Pirbhai, D. M. Ryan, G. Richards, Timothy J. Gay

Timothy J. Gay Publications

A compact optical electron polarimeter using a helium target is described. It offers a maximum fluorescence detection efficiency of ∼20 Hz/nA, which is an order of magnitude higher than that of earlier designs. With an argon target, this device is expected to have a polarimetric figure-of-merit of 270 Hz/nA. By relying on a magnetic field to guide a longitudinally spin-polarized electron beam, the present instrument employs fewer electrodes. It also uses a commercially available integrated photon counting module. These features allow it to occupy a smaller volume and make it easier to operate.

Two Novel Approaches For Electron Beam Polarization From Unstrained Gaas, James L. Mccarter, Nathan B. Clayburn, J. M. Dreiling, Timothy J. Gay, Dominic M. Ryan, John Hansknecht, Matt Poelker, Andrei Afanasev, Ara Kechiantz

Timothy J. Gay Publications

Two novel approaches to producing highly-polarized electron beams from unstrained GaAs were tested using a micro-Mott polarimeter. Based on a suggestion by Nakanishi [1]], twophoton photoemission with 1560 nm light was used with photocathodes of varying thickness: 625m, 0.32m, and 0.18m. For each of these photocathodes, the degree of spin polarization of the photoemitted beam was less than 50%. Polarization via two-photon absorption was highest from the thinnest photocathode sample and close to that obtained from one-photon absorption (using 778 nm light), with values 40.3±1.0% and 42.6±1.0%, respectively. The second attempt to produce highly-polarized electrons used one-photon emission with 778 …

The Machete Number, David Freund

Senior Independent Study Theses

Knot theory is a branch of topology that deals with the structure and properties of links. Employing a variety of tools, including surfaces, graph theory, and polynomials, we develop and explore classical link invariants. From this foundation, we de fine two novel link invariants, braid height and machete number, and investigate their properties and connection to classical invariants.

Changing Molecular Band Offsets In Polymer Blends Of (P3ht/P(Vdf–Trfe)) Poly(3-Hexylthiophene) And Poly(Vinylidene Fluoride With Trifluoroethylene) Due To Ferroelectric Poling, Freddy Wong, Godohaldo Perez, Manuel Bonilla, Juan A. Colon-Santana, Xin Zhang, Pankaj Sharma, Alexei Gruverman, Peter A. Dowben, Luis G. Rosa

Peter Dowben Publications

Photoelectron emission and inverse photoemission spectroscopy studies of polymer blends of poly(vinylidene fluoride (70%) – trifluoroethylene (30%)) P(VDF–TrFE 70 : 30) and regio-regular poly(3- hexylthiophene) (P3HT) provide evidence of changes in the molecular band offsets as a result of changes in the ferroelectric polarization in P(VDF–TrFE). Investigation of the blends with higher concentrations of the semiconducting P3HT component revealed that the organic semiconductor component of the blend dominates the electronic structure in the vicinity of the chemical potential. Specifically, the states of P3HT at the conduction band minimum and valence band maximum fall within the HOMO–LUMO gap of the dielectric …

Induced Magneto-Electric Coupling In Ferroelectric/Ferromagnetic Heterostructures, Jeffery Carvell, Ruihua Cheng, Peter A. Dowben, Q Yang

Peter Dowben Publications

Using an external magnetic field, we have demonstrated room temperature control of the electric polarization of a ferroelectric polymer, polyvinylidene fluoride (PVDF), in an artificial multiferroic structure. For ferroelectric PVDF polymer thin films in an iron-PVDF-iron heterostructure, both the ferroelectric coercivity and polarization display a hysteresis dependence on the external magnetic field. We also find that the thickness of the PVDF layer has an effect on the magnetoelectric coupling in our samples. We observe a giant magnetoelectric coupling with values as large as 3700 V/cm Oe to 41700 V/cm Oe.