Physical Sciences and Mathematics Commons^™

Education In The Environment: A Strategy For Continued Interagency Outdoor Education Programming: Fourth Quarter Progress Report With Annual Report: Period Ending May 31, 2010, Margaret N. Rees

Reports (PLI Education)

Highlights of the university’s focused efforts during the past three months include the following:

• An Evaluation Report was produced for the Families in Nature program.
• The report “Reaching SNAP Audiences: Documenting the number of people reached through environmental education and interpretation programs and activities has been produced.
• Two Families in Nature field trips benefitted 85 people.
• Exhibit IQ, an exhibit design company, has been retained to develop an exhibit design plan, prepare the RV, and fabricate and install exhibits.
• Forever Earth was scheduled on 49 days involving 1639 individuals.
• Discover Mojave Outdoor World conducted 16 events for 333 participants.

Chemical Investigation Of The Antarctic Marine Invertebrates Synoicum Adareanum And Artemisina Plumosa, Jaime Heimbegner Noguez

USF Tampa Graduate Theses and Dissertations

Of the small percentage of organisms chemically investigated over the years as potential sources of natural products, much less is known about those from the marine realm. Despite the lack of attention they have received in comparison to terrestrial organisms, marine life have recently been found to represent a valuable source for novel bioactive compounds. Cold water marine habitats are home to a plethora of organisms that have the ability to produce secondary metabolites that exhibit a great deal of diversity in both their chemical structures and biological activities. The chemical investigation of these unique and relatively unstudied ecosystems is …

A Multistage Incidence Estimation Model For Diseases With Differential Mortality, Alyssa W. Dray

HMC Senior Theses

According to theWorld Health Organization, surgically removable cataract remains the leading cause of blindness worldwide. In sub-Saharan Africa, cataract surgical rate targets should ideally be set based on cataract incidence (the number of new cataracts developed each year). Unfortunately, the longitudinal studies necessary to measure incidence have not yet been feasible in these areas. Our research instead proposes a method for estimating incidence based on available cataract prevalence data. We extend a method proposed by Podgor and Leske (1986) to estimate age-specific incidence from age-specific prevalence in single diseases with differential mortality. A two-stage disease extension is created in order …

Computational Feasibility Of Increasing The Visibility Of Vertices In Covert Networks, Yaniv J. Ovadia

HMC Senior Theses

Disrupting terrorist and other covert networks requires identifying and capturing key leaders. Previous research by Martonosi et al. (2009) defines a load metric on vertices of a covert network representing the amount of communication in which a vertex is expected to participate. They suggest that the visibility of a target vertex can be increased by removing other, more accessible members of the network. This report evaluates the feasibility of efficiently calculating the optimal subset of vertices to remove. We begin by proving that the general problem of identifying the optimally load maximizing vertex set removal is NP-complete. We then consider …

Combinatorial Proofs Using Complex Weights, Bo Chen

HMC Senior Theses

In 1961, Kasteleyn, Fisher, and Temperley gave a result for the number of possible tilings of a 2m 2n checkerboard with dominoes. Their proof involves the evaluation of a complicated Pfaffian. In this thesis we investigate combinatorial strategies to evaluate the sum of evenly spaced binomial coefficients, and present steps towards a purely combinatorial proof of the 1961 result.

Arithmetic On Specializable Continued Fractions, Ross C. Merriam

HMC Senior Theses

No abstract provided.

Minimal Circuits For Very Incompletely Specified Boolean Functions, Richard Strong Bowen

HMC Senior Theses

In this report, asymptotic upper and lower bounds are given for the minimum number of gates required to compute a function which is only partially specified and for which we allow a certain amount of error. The upper and lower bounds match. Hence, the behavior of these minimum circuit sizes is completely (asymptotically) determined.

Group Frames And Partially Ranked Data, Kwang B. Ketcham

HMC Senior Theses

We give an overview of finite group frames and their applications to calculating summary statistics from partially ranked data, drawing upon the work of Rachel Cranfill (2009). We also provide a summary of the representation theory of compact Lie groups. We introduce both of these concepts as possible avenues beyond finite group representations, and also to suggest exploration into calculating summary statistics on Hilbert spaces using representations of Lie groups acting upon those spaces.

A Nonlinear Ode Model Of Tumor Growth And Effect Of Immunotherapy And Chemotherapy Treatment In Colorectal Cancer, Hannah P. Savage

HMC Senior Theses

Colorectal cancer will kill approximately 50,000 people in the United States this year. Current treatment options, including surgery, chemotherapy, and radiation, are often able to force the cancer into remission, but better treatments are needed to help those who don't respond to current treatments. A new and promising treatment option, monoclonal-antibody therapy, has the potential to help reduce the deaths caused by colorectal cancer, but most monoclonal-antibody drugs are currently still in trial phases, and the variations in the dosing schedule of those currently approved for use have not been heavily explored. We have modified a nonlinear ODE tumor/treatment model …

Optimizing Restaurant Reservation Scheduling, Jacob Feldman

HMC Senior Theses

We consider a yield-management approach to determine whether a restaurant should accept or reject a pending reservation request. This approach was examined by Bossert (2009), where the decision for each request is evaluated by an approximate dynamic program (ADP) that bases its decision on a realization of future demand. This model only considers assigning requests to their desired time slot. We expand Bossert's ADP model to incorporate an element of flexibility that allows requests to be assigned to a time slot that differs from the customer's initially requested time. To estimate the future seat utilization given a particular decision, a …

Understanding Voting For Committees Using Wreath Products, Stephen C. Lee

HMC Senior Theses

In this thesis, we construct an algebraic framework for analyzing committee elections. In this framework, module homomorphisms are used to model positional voting procedures. Using the action of the wreath product group S2[Sn] on these modules, we obtain module decompositions which help us to gain an understanding of the module homomorphism. We use these decompositions to construct some interesting voting paradoxes.

Branching Fractions For Chi_Cj -> P P-Bar Pi^0, P P-Bar Eta, And P P-Bar Omega, Raymond Mountain, Marina Artuso, S. Blusk, R. Mountain

Physics - All Scholarship

Using a sample of 25.9 million psi(2S) decays acquired with the CLEO-c detector at the CESR e^+e^- collider, we report branching fractions for the decays chi_cJ -> p p-bar pi^0, p p-bar eta, and p p-bar omega, with J=0,1,2. Our results for B(chi_cJ-> p p-bar pi^0) and B(chi_cJ-> p p-bar eta) are consistent with, but more precise than, previous measurements. Furthermore, we include the first measurement of B(chi_cJ-> p p-bar omega).

Branching Fractions For Χcj → Ppπ0, Ppη, And Ppω, Raymond Mountain, Marina Artuso, S. Blusk, T. Skwarnicki

Physics - All Scholarship

Using a sample of 25.9 million psi(2S) decays acquired with the CLEO-c detector at the CESR e^+e^- collider, we report branching fractions for the decays chi_cJ -> p p-bar pi^0, p p-bar eta, and p p-bar omega, with J=0,1,2. Our results for B(chi_cJ-> p p-bar pi^0) and B(chi_cJ-> p p-bar eta) are consistent with, but more precise than, previous measurements. Furthermore, we include the first measurement of B(chi_cJ-> p p-bar omega).

Upper Ocean Response To The Atmospheric Cold Pools Associated With The Madden-Julian Oscillation, Suyang Pei, Toshiaki Shinoda, Alexander Soloviev, Ren-Chieh Lien

Marine & Environmental Sciences Faculty Articles

Atmospheric cold pools are frequently observed during the Madden‐Julian Oscillation events and play an important role in the development and organization of large‐scale convection. They are generally associated with heavy precipitation and strong winds, inducing large air‐sea fluxes and significant sea surface temperature (SST) fluctuations. This study provides a first detailed investigation of the upper ocean response to the strong cold pools associated with the Madden‐Julian Oscillation, based on the analysis of in situ data collected during the Dynamics of the Madden‐Julian Oscillation (DYNAMO) field campaign and one‐dimensional ocean model simulations validated by the data. During strong cold pools, SST …

Surface Roughness Effect On Ultracold Neutron Interaction With A Wall And Implications For Computer Simulations, Albert Steyerl, Surendra S. Malik, A. M. Desai, Charles Kaufman

Physics Faculty Publications

We review the diffuse scattering and the loss coefficient in ultracold neutron reflection from slightly rough surfaces, report a surprising reduction in loss coefficient due to roughness, and discuss the possibility of transition from quantum treatment to ray optics. The results are used in a computer simulation of neutron storage in a recent neutron lifetime experiment that reported a large discrepancy of neutron lifetime with the current particle data value. Our partial reanalysis suggests the possibility of systematic effects that were not included in this publication.

Creating A Habitat Suitability Index Model For Argali Sheep (Ovis Ammon), And Siberian Ibex (Capra Sibirica) In Ikh Nartin Reserve, Mongolia, Nanette Bragin

Geography and the Environment: Graduate Student Capstones

Mongolia is a country with a park system of protected areas, preserving native flora and fauna. In order to inform decision makers about the status of endangered species and park land health, two species of concern, the Argali sheep (Ovis ammon) and Siberian ibex Capra siberica) in the Ikh Nart Reserve in Mongolia were studied. A Habitat Suitability Index Model was developed to study the Argali and ibex habitat preference and discern if the reserve and core zone offer optimal habitat. A total of 57 animals were examined, creating 95% and 50% home range kernels, and minimum convex polygons. The …

A Case Study Of Network Design For Middle East Water Distribution, Rachel Bullene

Theses and Dissertations

The Middle Eastern region encompassing Israel, Jordan, and the Palestinian Territories (West Bank and Gaza) is an arid region with fast growing populations. Adequate and equitable access to water for all the people of the region is crucial to the future of Middle East peace. However, the current water distribution system not only fails to provide an adequate and equitable allocation of water, but also results adverse impacts on the environment. This project involves building a mathematical model to aid decision-makers in designing an optimal water distribution network. A new method for incorporating uncertainty in optimization that is based on …

A High Performance Sulfur/Carbon Xerogel Composite In Lithium Sulfur Battery Application, Chong Wang, Jia-Jia Chen, Qiu-Jie She, Qian Zhang, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Sulfur/carbon composite was synthesized by the thermal method with the carbon xerogel as the conductive framework. The property of composite was characterd by XRD and SEM. It shown that the composite with the particle size below 10 μm had the same morphology as the carbon xerogel and the sulfur was absorbed in the pores in non-crystalline. The discharge capacity of the composites were 1311 mAh/g and 1107. 1 mAh/g at 0. 1C and 0. 2 C rates,respetively. And a retention capacity was about 800 mAh/g after 30 cylcyes.

Nano/Micro-Structured Electrode Materials For Lithium-Ion Batteries, Yu-Guo Guo, Zhong-Li Wang, Xing-Long Wu, Wei-Ming Zhang, Li-Jun Wan

Journal of Electrochemistry

Nanostructured materials are currently of interest as high performance anodes and cathodes for rechargeable lithium-ion batteries because of their novel nano-size effects and significantly enhanced kinetics. This review paper describes some recent developments in this field,addressing the size effects,morphology effects,as well as the functions of carbon coating layers toward lithium storage. Several"kinetically stabilized"nano/microstructured electrode materials and high-rate electrode materials with mixed-conducting networks based on the work of the authors are highlighted for illustration.

Failure Reaction Mechanism Of Internal Short-Circuit For Lithium-Ion Batteries, He Li, Shen-Jun Yu, Zhi-Kui Chen, Guang-Chuan Liang

Journal of Electrochemistry

In this work,the battery impact testing machine has been used to study the failure progress of internal short-circuit ( ISC) for lithium ion batteries. The reaction mechanisms between cathode/anode and electrolyte in the battery at different temperatures were characterized by differential scanning calorimetry ( DSC) ,gas chromatography/mass spectrometry ( GC/MS) and X-ray diffraction ( XRD) . The experimental results show that the ISC failure of the battery was mainly due to the reaction between cathode Li0.5CoO2 and electrolyte. The decomposition and oxygen evolution reactions of cathode occurred when the temperature reached a certain value. At the same time a fierce …

Hydrogen Evolution Reaction Activtity Of Ni-Ru-Ir Oxide Cathode Coating, Yin-Hui Fu, Xue-Ming Li, Wu-Lin Li, Jun Zhang

Journal of Electrochemistry

The Ni-Ru-Ir electrode coating was fabricated by thermal decomposition and oxidation. Electrochemical properties of Ni-Ru-Ir electrode coating and pure nickel cathode in the 30% NaOH solutions at 90 ℃( conditions of the industrial electrolysis) ,have been investigated by cyclic voltammetry,Tafel curves and chronoamperometry. The results show that the Ni-Ru-Ir oxide electrode coating exhibited high catalytic activity. At the current density of 0. 3 A·cm-2,the lowest hydrogen evolution overpotential of Ni-Ru-Ir oxide electrode coating was about 300 mV lower than Ni. The roughness and excharge current density of Ni-Ru-Ir electrode coating were 32 and 4 times,respectively,larger than those of pure nickel …

Inhomogeneity-Induced Spin Current In Atomic And Condensed Matter Systems, Bailey Hsu

Theses and Dissertations

I derive and apply quantum propagator techniques to atomic and condensed matter systems. I observe many interesting features by following the evolution of a wavepacket. In atomic systems, I revisit the Stern-Gerlach effect and study the spin dynamics inside an inhomogeneous magnetic field. The results I obtained are not exactly the same as the textbook description of the effect which is usually a manifestation of a perfect space and spin entanglement. This discovery can provide insight on more reliable quantum computation device designs. In condensed matter systems, the doping concentration inhomogeneity leads to the Rashba spin-orbit interaction. This makes it …

Preparation And Electrochemical Performance Of Three-Dimensional Porous Snco Alloy Electrode, Lian-Jie Xue, Ling Huang, Fu-Sheng Ke, Guo-Zhen Wei, Xiao-Mei Zheng, Jun-Tao Li, Xiao-Yong Fan, Shi-Gang Sun

Journal of Electrochemistry

Three-dimensional porous Cu film was prepared by electroless plating,and used as a current collector for preparation of three-dimensional structured SnCo alloy electrode,which was mainly prepared by an electrodeposition method,and composed of pure Sn and CoSn2 phases. Electrochemical experimental results show that three-dimensional structured SnCo alloy electrode exhibits much better cycleability than planar SnCo alloy electrode,with first discharge capacity and charge capacity of 636. 3 and 528. 7 mAh·g-1,respectively. After 70th cycling,capacity retention is 83. 1% with 529. 5 mAh·g-1. The lithiation process during first discharge was investigated by electrochemical impedance spectroscopy

Electrocatalytic Oxidation Of Hcooh At Au_(Core)-Pd_(Shell)-Pt_(Cluster) Nanocubes, Qing-Ning Jiang, Huan Li, Ning Yang, Ping-Ping Fang, Feng-Ru Fan, Zhong-Qun Tian

Journal of Electrochemistry

Gold nanocubes were synthesized by a two-step seed-mediated growth method. The Aucore-Pdshell and Aucore-Pdshell-Ptcluster nanocubes with controllable shell thickness of Pd and cluster coverage of Pt were synthesized by simply changing the amount ratio of H2PdCl4 or H2PtCl6. The samples were characterized by scanning electron microscope ( SEM) 、transmission electron microscopc ( TEM) and cyclic voltammetry ( CV) . CV was then used to make a systematic study on the dependence of the electrocatalytic properties on the shell thickness of Aucore-Pdshell and Pt coverage of Aucore-Pdshell-Ptcluster,respectively. The results indicated that the Au nanocube core coated by three atomic layers of …

Measurement And Wavelet Analysis Of The Electrochemical Noise Of Rebar Steel In Simulated Concrete Pore Solution, Rong-Gang Hu, Chen-Qing Ye, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

Electrochemical noise ( ECN) measurement can provide information about both corrosion rate and corrosion type while inflicting no perturbation on the studied system. The ECN data of steel rebar in SPS with different amount of Cl-were collected and treated by discrete wavelet transformation to evaluate the contribution from transients in different frequency in the overall signals. Energy distribution plot( EDP) indicated in SPS with 0. 0001 mol/L NaCl,the transients with time constant between 16 ～ 32 s were found to be predominant over other processes; while in SPS with higher Cl-concentration,the trend toward active corrosion became the main process. It …

Research On Electrochemical Performance Of Lithium-Ion Battery Cathode Material Lini_(1/3)Co_(1/3)Mn_(1/3)O_2 In Aqueous Lino_3 Solution, Jun Zheng, Xin Jia, Chong Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode material of LiNi1/3Co1/3Mn1/3O2 synthesized by sol-gel method shows excellent high rate performance,and high output power density during discharge process. A well-ordered layered α-NaFeO2 structure was confirmed by XRD and a primary particle size of about 500 nm was indicated by SEM. Galvanostatic charge-discharge test indicates that LiNi1/3Co1/3Mn1/3O2 in 2 mol·L-1 LiNO3 aqueous solution with pH 12 reached a ca-pacity of 147 mAh/g while charged and discharged at 2C. The capacities were 64、33、16 mAh/g with 80C ( 14. 4 A/g) 、150C( 27 A/g) and 220C ( 39. 6 A/g) charge/discharge rates,while the power densities of the battery were 2574 …

Fabrication Of Electrochemically Activated Glassy Carbon/Bismuth Film Electrodes For Sensitive Analysis Of Pb～(2+) And Cd～(2+), Kang Shi, Wen-Jing Wang, Kun Hu

Journal of Electrochemistry

The application of electrochemically activated glassy carbon ( GC) in the in-situ preparing of bismuth film electrodes ( BiFEs) to analyze Pb2 + and Cd2 + was investigated. The glassy carbon electrodes were electrochemically activated by either potentiostic or cyclic polarization in 1 mol·L-1 NaOH solution. Experimental results show that employment of HCl solution as the analytical solution not only can reproducibly renew the electrochemically activated GC electrode surface with an electrochemical clear procedure,but also can greatly enhance the sensitivity of BiFes method for analysis of Pb2 + and Cd2 + . The test range thus was extended to the …

Preparation And Application Of Ti/Ceo_2-F-Pbo_2 Electrode In Electrochemical Degradation Of Organics, Xun-Hua Wang, Tie-Ming Zhang, Shao-Ping Tong, Chun-An Ma

Journal of Electrochemistry

The CeO2-modified PbO2 on Ti plate ( Ti/CeO2-F-PbO2) was prepared by electrodeposition. The SEM and XRD analyses indicated that the CeO2 particle could be beuniformly co-deposited in the film of PbO2. The results of electrochemical test showed that the Ti/CeO2-F-PbO2 anode had higher potential ( 1. 83 V. vs. SCE) for oxygen evolution ( OE) than the Ti/F-PbO2 anode ( 1. 78 V,vs. SCE) . The degradation of 4-chlorophenol was carried out to test electrocatalytic performance of this novel electrode,which indicated that Ti/CeO2-F-PbO2 anode had high COD removal rate and instantaneous current efficiencies ( ICE) .

Synthesis Of Cosalen Composite In Apo-5 And Its Electrocatalytic Behaviour For Reaction Of Dioxygen Reduction, Rong Zhang, Li-Hua Tang, Bin-Bin Fan, Jing-Hong Ma, Rui-Feng Li

Journal of Electrochemistry

CoAPO-5 molecular sieve was hydrothermally synthesized. The Cobalt ions in CoAPO-5 were coordinated with the SALEN ligend diffusing into the channels of the molecular sieve to form CoSALEN complexes. The electrochemical behaviors and electrocatalysis for dioxygen reduction of the CoSALEN complex immobilized in APO-5 modified glassy carbon electrodes ( GCEs) have been investigated by cyclic voltammetry( CV) and chronoamperometry ( CA) in differrent pH aqueous solutions. The results showed that the PS/CoSALEN/APO-5 /GC modified electrode is of the high electrocatalytic activity towards dioxygen reduction in pH 6. 86 buffer solution with a reduced overpotential of 447 mV lower than bare …

Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling

Journal of Electrochemistry

Micro-crystallite carbon ( CC) was synthesized by KOH activation of carbonized petroleum coke precursors. The porous properties structure and crystallite structure were characterized by N2 adsorption-desorption, X-ray diffraction ( XRD) measurements. The capacitive behavior of CC was investigated in the electrolyte of Et4NBF4 /PC,Et4NBF4 /AN,Bu4NBF4 /PC and Bu4NBF4 /AN,respectively. Results showed that the lower potential of electric field activation ( EFA) was obtained in the solvent of AN than in PC,which was ascribed to the fact that smaller solvated ions dimension in AN facilitating the intercalation of the solvated ions into micro-crystallite interlayer. The extent of EFA was more remarkable …