Physical Sciences and Mathematics Commons^™

Development Of A Scalable Synthesis Of Hp-Β-Cd Pluronic Polyrotaxanes, Joseph L. Skulsky, Elizabeth A. Slepko, Bradley P. Loren, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

Polyrotaxanes are polymers that have macrocycles threaded onto them, analogous to beads threaded onto a string. These materials are used for a variety of different biomedical applications.^1-3 The Thompson group has been developing 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) polyrotaxanes as therapeutics for the treatment of Niemann-Pick Type C (NPC) disease. NPC is a debilitating genetic disorder where cholesterol accumulates in the lysosomes of cells.⁴ Developing a scalable process is crucial for the advancement of these materials as NPC therapeutics. The goal of this project is to optimize the only protocol for the synthesis of HP-β-CD/Pluronic polyrotaxanes in order to develop a …

Using Dissipative Particle Dynamics For Modeling Surfactants, Yuchen Zhang, Arezoo M. Ardekani

The Summer Undergraduate Research Fellowship (SURF) Symposium

Oil recovery is an industrial process that injects aqueous solutions into an oil reservoir to pump out crude oil and promote the oil production. The aqueous solution contains surfactants for reducing the interfacial tension (IFT) between aqueous phase and oil. The critical micelle concentration (CMC) is the concentration of surfactant above which micelles form and the interfacial tension reaches a plateau. Our research seeks to measure IFT and CMC for surfactants using dissipative particle dynamics (DPD) technique, which is a coarse-grained method based on the molecular dynamics. We first study how IFT is influenced by the surfactant concentration. Furthermore, another …

Optical Emission Spectroscopy Diagnostics Of Cold Plasmas For Food Sterilization, Abhijit Jassem, Michael Lauria, Russell Brayfield Ii, Kevin M. Keener, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

There is a growing need for economical, effective, and safe methods of sterilizing fresh produce. The most common method is a chlorine wash, which is expensive and may introduce carcinogens. High voltage cold atmospheric pressure plasmas are a promising solution that has demonstrated a germicidal effect; however, the responsible chemical mechanisms and reaction pathways are not fully understood. To elucidate this chemistry, we used optical emission spectroscopy to measure the species produced in the plasma generated by a 60 Hz pulsed dielectric barrier discharge in a plastic box containing various fill gases (He, N₂, CO₂, dry …

Web-Based Fragment Library, Junjie Wang, Lyudmila Slipchenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

A new polarized force field BioEFP for modeling process in biology is far superior in accuracy to the common classical force fields. One of the main shortcomings of BioEFP is that the parameters are not readily available, thus it will take a lot of time to be calculated.

Developing an online repository of pre-computed fragment parameters and a similarity algorithm will allow ascribing each fragment of a biological macromolecule to a pre-defined fragment.

This study incorporates three parts to create the online repository. First, the visual design for the website using the Hypertext Markup Language and the Cascading Style Sheets …

Classification And Visualization Of Crime-Related Tweets, Ransen Niu, Jiawei Zhang, David S. Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

Millions of Twitter posts per day can provide an insight to law enforcement officials for improved situational awareness. In this paper, we propose a natural-language-processing (NLP) pipeline towards classification and visualization of crime-related tweets. The work is divided into two parts. First, we collect crime-related tweets by classification. Unlike written text, social media like Twitter includes substantial non-standard tokens or semantics. So we focus on exploring the underlying semantic features of crime-related tweets, including parts-of-speech properties and intention verbs. Then we use these features to train a classification model via Support Vector Machine. The second part is to utilize visual …

Gpu/Cpu Performance Of Image Processing Tasks For Use In The Cam 2 System, Jonathan Cottom, Yung-Hsiang Lu, Young-Sol Koh

The Summer Undergraduate Research Fellowship (SURF) Symposium

Over the past several years, graphics processing units (GPU) have increasingly been viewed as the future of image processing engines. Currently, the Continuous Analysis of Many CAMeras (CAM²) project performs its processing on CPUs, which will potentially be more costly as the system scales to service more users. This study seeks to analyze the performance gains of GPU processing and evaluate the advantage of supporting GPU-accelerated analysis for CAM² users. The platform for comparing the CPU and GPU performance has been the NVIDIA Jetson TK1. The target hardware implementation is an Amazon cloud instance, where final cost …

Kinetic Modeling Of Roll To Roll Rfcvd Plasma, Kudzo S. Ahegbebu, Siva Sashank Tholeti, Alina A. Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

Roll-to-roll radio frequency plasma enhanced chemical vapor deposition (R2R RFCVD) is a technique for large-scale synthesis of high quality graphitic nanopetals. Graphitic nanopetals are petal-like graphene structures with remarkable electrical and mechanical properties with major industrial applications such as microsupercapacitors. RFCVD uses a non-equilibrium plasma with high energy electrons to catalyze chemical reactions, induce the creation of free radicals, and promote otherwise high temperature chemistry in a low temperature environment. Understanding how bulk plasma characteristics (particularly, power and number densities) vary with changing reactor parameters is an important step towards optimizing synthesis techniques. In our present work we use the …

Dsmc Simulation Of Microstructure Actuation By Knudsen Thermal Force, Aaron Pikus, Israel Sebastiao, Andrew Strongrich, Alina Alexeenko

The Summer Undergraduate Research Fellowship (SURF) Symposium

In many industrial and research applications there is a need for vacuum sensors with higher accuracy and spatial resolution than what is currently available. Examples of target applications include high-altitude platforms, satellites and in-vacuum manufacturing processes such as freeze-drying of food and pharmaceuticals. In this connection, a novel pressure sensor, named Microelectromechanical In-plane Knudsen Radiometric Actuator (MIKRA), has been developed by at Purdue University. MIKRA is based on Knudsen thermal forces generated by rarefied flow driven by thermal gradients within the microstructure Thus, the goal of this work is to model the rarefied gas flow in the MIKRA sensor under …

Bio-Inspired Composite Hydrogels For Osteochondral Regenerative Engineering, Grant N. Gellert, Liangju Kuang, Chunhui Jiang, Nur P. Damayanti, Joseph Irudayaraj, Meng Deng

The Summer Undergraduate Research Fellowship (SURF) Symposium

Treatment of osteochondral defects encompassing injury or degeneration to both the articular cartilage as well as the underlying subchondral bone presents a significant medical challenge. Current treatment options including autografts and allografts suffer from limited availability and risk of immunogenicity, respectively. The long term goal of this work is to develop an integrated scaffold system for treatment of osteochondral defects via in situ regeneration of bone, cartilage and the bone-cartilage interface. Hydrogels composed of polymer networks swollen in water provide an attractive biomaterial platform for regeneration of cartilage. In the present study, we have developed a novel composite hydrogel consisting …

Synthesis, Characterization, And Thermoelectric Properties Of Radical Siloxanes, Arnold J. Eng, Bryan Boudouris, Edward P. Tomlinson, Martha Emily Hay

The Summer Undergraduate Research Fellowship (SURF) Symposium

More than half of the annual energy consumption in the United States is lost as waste heat. Polymer-based thermoelectric devices have the potential to utilize this waste heat both sustainably and cost-effectively. Although conjugated polymers currently dominate research in organic thermoelectrics, the potential of using polymers with radical pendant groups have yet to be realized. These polymers have been found to be as conductive as pristine (i.e., not doped) poly(3-hexylthiophene) (P3HT), a commonly-used charge-transporting conjugated polymer. This could yield promising avenues for thermoelectric material design as radical polymers are more synthetically tunable and are hypothesized to have a high Seebeck …

Deconstructing Cation-Pi Interactions: Understanding The Binding Energies Involved With Metal And Aromatic Amino Acid Residues, Jen E. Werner, Lyudmila V. Slipchenko, Yen Bui

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Effective Fragment Potential (EFP) method is a computationally efficient technique for describing non-covalent interactions, such as hydrogen bonding and van der Waals forces. Cation-pi interactions are a type of non-covalent interactions and are thought to be important in biological processes, such as permittivity of ion channels. The goal of our work is to establish that the EFP method reliably describes the strength, directionality, and composition of cation-pi interactions. Optimal geometries were found for a series of biologically relevant cations (K⁺, Li⁺, Na⁺, Ca²⁺, and Mg²⁺) and aryl moieties appearing …

Experimental Design And Construction For Critical Velocity Measurement In Spin-Orbit Coupled Bose-Einstein Condensates, Ting-Wei Hsu, Yong P. Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Quantum simulation using ultra-cold atoms, such as Bose-Einstein Condensates (BECs), offers a very flexible and well controlled environment to simulate physics in different systems. For example, to simulate the effects of spin orbit coupling (SOC) on electrons in solid state systems, we can make a SOC BEC which mimics the behavior of SOC electrons. The goal of this project is to see how the superfluid property of BECs change in the presence of SOC. In particular, we plan to measure the critical velocity of an 87Rb BEC with and without SOC by stirring it with a laser. This laser needs …

Quantifying Groundwater/Surface-Water Interactions In Tributaries To The Wabash River Using Radon‐222 And Other Environmental Isotopes, Philine Bogeholz, Marty Frisbee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Groundwater/surface-water interactions have not been extensively studied in tile-drained watersheds where natural recharge processes are “short circuited” by routing water out of the soil-zone and into nearby drainage ditches. This practice likely impacts baseflow generation in the Wabash River of Indiana. If true, then how is baseflow affected in small tributaries to the Wabash? To answer this question, we investigated groundwater/surface-water interactions in four small tributary drainages to the Wabash River and Sugar Creek. These drainages share common geologic characteristics and are deeply incised providing a window into groundwater flow processes. We sampled these drainages for general geochemistry, radon-222 ( …

Model Selection For Gaussian Mixture Models For Uncertainty Qualification, Yiyi Chen, Guang Lin, Xuan Liu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Clustering is task of assigning the objects into different groups so that the objects are more similar to each other than in other groups. Gaussian Mixture model with Expectation Maximization method is the one of the most general ways to do clustering on large data set. However, this method needs the number of Gaussian mode as input(a cluster) so it could approximate the original data set. Developing a method to automatically determine the number of single distribution model will help to apply this method to more larger context. In the original algorithm, there is a variable represent the weight of …

Determination Of Total Peroxide Content In Secondary Organic Aerosol Particles, Matthew E. Wise

Matthew E. Wise

Secondary organic aerosol particles (SOA) formed from the oxidation of monoterpenes can impact the Earth’s radiation balance, act as cloud condensation nuclei and negatively affect human health. In the initial Visiting Faculty Program application, we proposed the use of an ultraviolet-visible spectrometer equipped with a liquid waveguide capillary flow cell to determine the extent to which SOA absorb visible light. The inclusion of Concordia University in the Secondary Organic Aerosol From Forest Emissions Experiment (SOAFFEE) laboratory campaign at PNNL necessitated a change in the proposed experiments. An iodometric-spectrophotometric (IS) technique was developed to quantify the total peroxide content in SOA. …

Physical, Thermal And Spectroscopic Characterization Of M-Toluic Acid: An Impact Of Biofield Treatment, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Ragini Singh, Snehasis Jana

Mahendra Kumar Trivedi

Biogenic Synthesis Of A Ag–Graphene Nanocomposite With Efficient Photocatalytic Degradation, Electrical Conductivity And Photoelectrochemical Performance, Mohammad Mansoob Khan Dr, Mohammad Ehtisham Khan, M. H. Cho Prof

Dr. Mohammad Mansoob Khan

This paper reports the environmentally benign, simple, cost efficient, one-step, surfactant free, and biogenic synthesis of silver-graphene (Ag-Graphene) nanocomposite using an electrochemically active biofilm (EAB). The EAB was used for the reduction of Ag+ to Ag0 onto the graphene sheets. The morphology, structure, composition, and optical properties and contact angle of the Ag-Graphene were obtained using a range of techniques which confirmed the anchoring/presence of silver nanoparticles (AgNPs) onto the graphene sheets. The photocatalytic activity of the Ag-Graphene was evaluated by the degradation of methylene blue and Congo red dye in aqueous solution at an ambient temperature in dark and …

Chaotic Behavior In Monetary Systems: Comparison Among Different Types Of Taylor Rule, Reza Moosavi Mohseni Dr., Wenjun Zhang Dr., Jiling Cao Prof.

Reza Moosavi Mohseni

The aim of the present study is to detect the chaotic behavior in the monetary economic relevant dynamical system. The study employs three different forms of Taylor rules: current, forward and backward looking. The result suggests the existence of the chaotic behavior in all three systems. In addition, the results strongly represent that using expectations in policy rule especially rational expectation hypothesis can increase the complexity of the system and leads to more chaotic behavior.

Generalizations And Algebraic Structures Of The Grøstl-Based Primitives, Dmitriy Khripkov, Nicholas Lacasse, Bai Lin, Michelle Mastrianni, Liljana Babinkostova (Mentor)

Idaho Conference on Undergraduate Research

With the large scale proliferation of networked devices ranging from medical implants like pacemakers and insulin pumps, to corporate information assets, secure authentication, data integrity and confidentiality have become some of the central goals for cybersecurity. Cryptographic hash functions have many applications in information security and are commonly used to verify data authenticity. Our research focuses on the study of the properties that dictate the security of a cryptographic hash functions that use Even-Mansour type of ciphers in their underlying structure. In particular, we investigate the algebraic design requirements of the Grøstl hash function and its generalizations. Grøstl is an …

Nanostructured Polymer Lithography For Photovoltaic Applications, Allison J. Christy, Nicholas L. Mckibben, Jerry D. Harris (Mentor), David Estrada (Mentor)

Idaho Conference on Undergraduate Research

The self-assembly of diblock copolymers into ordered domains holds great potential to furthering the efficiency of photovoltaic devices. Solutions containing polystyrene-block-poly(ethylene oxide) (PS-b-PEO) and poly(methyl methacrylate) (PMMA) were applied to silicon wafers from toluene solutions. Hexagonally ordered domains, with pore sizes ranging from 10-30 nm, were obtained by annealing films in solvent vapor, with the best results produced from a humidified benzene environment. Exposing the films to UV light cross-linked the polystyrene matrix and degraded the PMMA. Removal of the PMMA and PEO produced an ordered polystyrene template, which can be used for nanolithography for the …

Foliations And Global Inversion, Eduardo C. Balreira

Eduardo Cabral Balreira

We consider topological conditions under which a locally invertible map admits a global inverse. Our main theorem states that a local diffeomorphism f : M → Rn is bijective if and only if Hn−1(M) = 0 and the pre-image of every affine hyperplane is non-empty and acyclic. The proof is based on some geometric constructions involving foliations and tools from intersection theory. This topological result generalizes in finite dimensions the classical analytic theorem of Hadamard-Plastock, including its recent improvement by Nollet-Xavier. The main theorem also relates to a conjecture of the aforementioned authors, involving the well known Jacobian Conjecture in …

Skew-Product Dynamical Dystems: Applications To Difference Equations, Saber Elaydi, Robert Sacker

Saber Elaydi

No abstract provided.

Asymptotic Solutions Of A Discrete Schrödinger Equation Arising From A Dirac Equation With Random Mass, Bernd Aulbach, Saber Elaydi, Klaus Ziegler

Saber Elaydi

For a Dirac particle in one dimension with random mass, the time evolution for the average wavefunction is considered. Using the supersymmetric representation of the average Green’s function, we derive a fourth order linear difference equation for the low-energy asymptotics of the average wavefunction. This equation is of Poincar´e type, though highly critical and therefore not amenable to standard methods. In this paper we show that, nevertheless, asymptotic expansions of its solutions can be obtained.

Difference Equations Versus Differential Equations, A Possible Equivalence For The Rössler System?, Christophe Letellier, Saber Elaydi, Luis Aguirre, Aziz Alaoui

Saber Elaydi

When a set of non linear differential equations is investigated, most of the time there is no analytical solution and only numerial integration techniques can provide accurate numerical solutions. In a general way the process of numerical integration is the replacement of a set of differential equations with a continuous dependence on the time by a model for which these time variable is discrete. When only a numerical solution is researched, a fourth-order Runge-Kutta integration scheme is usually sufficient. Nevertheless, sometimes a set of differential equations may be required and, in this case, standard schemes like the forward Euler, backward …

Is The World Evolving Discretely?, Saber Elaydi

Saber Elaydi

No abstract provided.

Global Stability Of Periodic Orbits Of Non-Autonomous Difference Equations And Population Biology, Saber Elaydi, Robert Sacker

Saber Elaydi

Elaydi and Yakubu showed that a globally asymptotically stable(GAS) periodic orbit in an autonomous difference equation must in fact be a fixed point whenever the phase space is connected. In this paper we extend this result to periodic nonautonomous difference equations via the concept of skew-product dynamical systems. We show that for a k-periodic difference equation, if a periodic orbit of period r is GAS, then r must be a divisor of k. In particular sub-harmonic, or long periodic, oscillations cannot occur. Moreover, if r divides k we construct a non-autonomous dynamical system having minimum period k and which has …

Periodic Difference Equations, Population Biology And The Cushing-Henson Conjectures, Saber Elaydi, Robert Sacker

Saber Elaydi

We show that for a k-periodic difference equation, if a periodic orbit of period r is globally asymptotically stable (GAS), then r must be a divisor of k. In particular sub-harmonic, or long periodic, oscillations cannot occur. Moreover, if r divides k we construct a non-autonomous dynamical system having minimum period k and which has a GAS periodic orbit with minimum period r. Our method uses the technique of skew-product dynamical systems. Our methods are then applied to prove two conjectures of J. Cushing and S. Henson concerning a non-autonomous Beverton-Holt equation which arises in the study of the response …

Stability Of Hyperbolic And Nonhyperbolic Fixed Points Of One-Dimensional Maps, Fozi M. Dannan, Saber Elaydi, Vadim Ponomarenko

Saber Elaydi

We present a complete theory for the stability of non-hyperbolic fixed points of one-dimensional continuous maps. As well as we give simple criteria for the global stability of general maps without using derivatives.

Nonautonomous Beverton-Holt Equations And The Cushing-Henson Conjectures, Saber Elaydi, Robert Sacker

Saber Elaydi

In [3] Jim Cushing and Shandelle Henson published two conjectures (see Section 3) related to the Beverton-Holt difference equation (with growth parameter exceeding one), which said that the B-H equation with periodically varying coefficients (a) will have a globally asymptotically stable periodic solution and (b) the average of the state variable along the periodic orbit will be strictly less than the average of the carrying capacities of the individual maps. They had previously [2] proved both statements for period 2.

Global Stability Of Cycles: Lotka-Volterra Competition Model With Stocking, Saber Elaydi, Abdul-Aziz Yakubu

Saber Elaydi

In this article, we prove that in connected metric spaces k - cycles are not globally attracting (where k>2). We apply this result to a two species discrete-time Lotka-Volterra competion model with stocking. In particular, we show that an k-cycle cannot be the ultimate life-history of evolution of all population sizes. This solves Yakubu's conjecture but the question on the structure of the boundary of the basins of attraction of the locally stable n-cycles is still open.