Research Day | 2008 Awardees

Agriculture | Undergraduate

UG_AGRICULTURE_TIPTONEffects of Wastewater Discharge on Pigeon Roost Creek

Kara Tipton
Faculty Research Advisor: Dr. Janice Branson

Wastewater from approximately 24,000 residents of the city of Cookeville (1) is discharged into Pigeon Roost Creek following treatment at Cookeville Wastewater Treatment Plant. The objective of this study is to determine discharge effects on water quality. Four sites were sampled - one 300 ft. above discharge (PR4), at discharge point (PR3), 1000 ft. below discharge (PR2), and one mile downstream from discharge (PR1). Laboratory analyses included biological oxygen demand (BOD), pH, conductivity, turbidity, and total coliform/E. Coli. Significant changes occurred in pH, conductivity, turbidity, and BOD at PR3. Total coliform did not change at any site, however, E. Coli levels fluctuated slightly. At PR1 all measured parameters were either the same as PR4 or beginning to return to previous levels. Discharge of treated wastewater produced localized effects, but water quality at a distance downstream approaches original levels.

Reference

  1. http://www.city-data.com/city/Cookeville-Tennessee.html

Human Ecology | Undergraduate

UG_HEC_ROHLINGEffect of Fat Sources on Drop Biscuit Acceptability

Beth Rohling and Ryan Tomlinson
Faculty Research Advisor: Dr. Cathy Hix-Cunningham

UG_HEC_TOMLINSONThe purpose of this experiment was to determine the sensory, physical, cost, and nutritional differences of drop biscuits made with three versions of saturated and unsaturated fats. The biscuits made with three ratios of mayonnaise to shortening were compared: 100%:0%, 50%:50%, and 0%:100%. They were evaluated by twenty panelists for color, flavor, texture, and overall acceptability. The drop biscuits were also assessed for air cell distribution, height, cost, and nutritional analysis. After two replications, differences between treatments were minor, although the 100% mayonnaise was preferred slightly more in all categories. Panelists detected little difference in color, flavor, texture, and overall acceptability, which is signified by close replication averages. Nutrient analysis and research suggested 100% mayonnaise was the more healthy fat choice. Although vegetable shortening is a common source of biscuit fat, mayonnaise proved to be an acceptable substitute.

Chemistry | Graduate

GRAD_CHEM_HUXFORDSynthesis and Characterization of Potential Anti-Cancer Agents: Phenanthrenequinone Thiosemicarazone Palladium Complexes

Rachel C. Huxford
Faculty Research Advisor: Dr. Edward C. Lisic

This work presents the synthesis and characterization of a new series of phenanthrenequinone thiosemicarbazone palladium complexes. One of these complexes, derived from phenanthrenequinone thiosemicarbazone, has previously been described in literature. This complex displayed activity against MCF-7 human breast cancer cells, suggesting that the other complexes are potential anti-cancer agents [1]. The other complexes of this series are derived from phenanthrenequinone methylthiosemicarbazone, phenanthrenequinone ethylthiosemicarbazone, phenanthrenequinone phenylthiosemicarbazone, and phenanthrenequinone benzylthiosemicarbazone. Each tridentate thiosemicarbazone ligand (L), reacted with K2PdCl4, results in a square planar palladium complex in the form Pd(L)Cl. The complexes were characterized via 1H nuclear magnetic resonance spectrometry, infrared spectrometry, and UV-Visible spectroscopy, and their magnetic susceptibilities were obtained. The crystal structure of the phenanthrenequinone benzythiosemicarbaone complex in N,N-dimethylformamide is presented.

Reference

  1. Padhye, Subhash; Afrasiabi, Zahra; Sinn, Ekk; Fok, Jansina; Mehta, Kapil; Rath, Nigam. Inorganic Chemistry Communications. 2005, 44 1154-1156.

GRAD_CHEM_MADIREDDYChemical Fingerprinting on Clandestine Methamphetamine by LC/MS/MS

Sri Bharat Madireddy
Faculty Research Advisor: Dr. Jeff Boles

Over the years Methamphetamine (N-methyl-1-phenylpropan-2-amine), a potent psycho-stimulant, abuse has been a major cause of concern throughout the world, especially in the State of Tennessee.1 Illicit manufacture of methamphetamine in clandestine laboratories has been carried out with the use of minimal over-the-counter ingredients.1 The present research is on positive identification of the location of the manufacturing unit by designing a 'signature profile, 'impurity profile' or 'chemical fingerprint' by LC/MS/MS.2 This is carried out by establishing a database of selected set of impurities by obtaining pure standards of those impurities and later comparing the seized samples with the database for positive identification of the types and quantities of impurities present, the method of synthesis, the proportions, source and purity of starting materials, the reaction conditions, and the purification procedures, if any. The research focuses on developing a method for obtaining chemical profile for clandestine methamphetamine by LC/MS/MS and further supporting the obtained results by designing a qualitative and quantitative technique using GS/MS/MS.

References

  1. United Nations, New York, Recommended methods for the identification and analysis of amphetamine, methamphetamine and their ring-substituted analogues in seized materials. ST/NAR/34 (2006)
  2. C.J. Koester, B.D. Andresen, P.M. Grant, Optimum methamphetamine profiling with sample preparation by Solid-Phase Micro extraction. J. Forensic Sci. 47 (2002) 1002-1007

Chemistry | Undergraduate

Investigation of Cofactor Reaction(s) in the PLP βCA Kinetic Assay

Taylor King
Faculty Research Advisor: Dr. Jeff Boles

Tryptophan Synthase (TS) is a bifunctional, tetrameric, and Pyridoxal-5’-Phosphate (PLP) dependent enzyme which catalyzes the last two steps in the biosynthesis of L-Tryptophan. TS is just one of the numerous enzymes broadly used in biochemical studies. The enzyme plays a critical role in synthetic organic chemistry and has received increased attention in the past decade. TS is widely used as a model in substrate channeling and protein-protein interaction studies, and in the production of novel L-Tryptophan analogs (Miles, 1995). Recently, a problem with the TS spectrophotometric assay was discovered (Henderson, 2001). The formation of Tryptophan by TS is monitored as an increase in absorbance at 290nm. Previous research discovered that in the absence of enzyme, a considerable increase in the absorbance at 290nm is noted. The non-enzymatic reaction occurs in various buffers, pH values, and varying concentrations. This poster seeks confirm that the increase in absorbance at 290nm is due to a reaction between β-Chloro-Alanine and PLP as was first suggested by previous researchers (Henderson, 2001 & Fortenberry, 2005). The use of liquid chromatography mass spectrometry mass spectrometry has revealed insight into the products formed by the reaction of these compounds. The proposed mechanisms explain how pyruvate is formed during the course of this reaction (Fortenberry, 2005), and this has been confirmed through experimentation. These non-enzymatic reactions that occur concurrently with enzymatic assays have far reaching implications in the biochemical community. Researchers have noted problems throughout the years but they were never able to explain what was seen in the laboratory (Gregerman, 1956). The aim of this research is to make light of the problems associated with PLP-dependant enzymes such as TS and potentially minimize their detriment to future research.

Comparison of a Series of Phenanthrolinequinone Thiosemicarbazone Compounds

Keith Steelman
Faculty Research Advisor: Dr. Edward C. Lisic

Condensations of ketones and semicarbazides to form semicarbazones is a common organic synthesis has been studied for many years. Thiosemicarbazones have fewer limitations due to their ability to complex with both soft and hard acids, including many of the later transition metals. Thiosemicarbazones attached to polycyclic compounds are additionally useful because of the visible color change that they undergo in the presence of metal ions in solution. Phenanthrolinequinone thiosemicarbazones are interesting since they are bifunctional because of the presence of the pair of nitrogens at the back of the ring system. These provide an additional bidentate binding site beyond the multidentate binding of the thiosemicarbazone “arm”. This presentation describes the synthesis and characterization of some new phenanthrolinedione-thiosemicarbazone compounds.

Synthesis and Characterization of New Chromone Thiosemicarbazone Compounds

Erica L. Stoner and Rachel C. Huxford
Faculty Research Advisor: Dr. Edward C. Lisic

Thiosemicarbazone compounds are potent biological agents [1-2], and also act as ligands to a whole host of transition metal ions such as palladium and nickel [3-5]. A series of eight new thiosemicarbazone and semicarbazone compounds synthesized from a formyl chromone backbone in our laboratory will be presented. The synthesis of this new series of compounds is straightforward, and characterization by 1H NMR and IR supports the proposed structures. Research efforts to synthesize the palladium complexes will also be discussed.

References

  1. Padhye, S. Coordination Chemistry Reviews. 1985, 63, 127 -160.
  2. West, Douglas X.; El-Sawaf, Ayman K.; Bain, Gordon A. Transition Metal Chemistry (1998), 23(1), 1-6.
  3. Afrasiabi, Zahra; Sinn, Ekkehard; Chen, Junnan; Ma, Yinfa; Rheingold, Arnold L.; Zakharov, Lev N.; Rath, Nigam; Padhye, Subhash. Inorganica Chimica Acta. 2004, 357, 271-278.
  4. Afrasiabi, Zahra; Sinn, Ekk; Lin, Weisheng; Ma, Yinfa; Campana, Charles; Padhye, Subhash. Journal of Inorganic Biochemistry. 2005, 99, 1526-1531.
  5. Padhye, Subhash; Afrasiabi, Zahra; Sinn, Ekk; Fok, Jansina; Mehta, Kapil; Rath, Nigam. Inorganic Chemistry Communications. 2005, 44, 1154-1156.

Computer Science | Graduate

GRAD_CSC_MALONEIncorporating Visualization in an Interpreted Language for Educational Benefit

Brandon Malone
Faculty Research Advisor: Dr. Frank Hadlock

While the notion of employing animation and visualization to intuitively explain algorithm behavior dates back to the 80s (1), the educational benefit of these visualizations remains largely untapped. Recent research into the utility of algorithm visualizations cites four key paradigms in educationally effective visualizations: responding, in which students answer questions about upcoming and past behavior; changing, in which students provide input to cause desired algorithm behavior; constructing, in which students create their own visualization; and presenting, in which students explain the algorithm with the visualization as an aid (2). This research investigates an interpreted programming language which espouses these paradigms by providing primitive constructs to simplify the creation and presentation of educationally effective visualizations.

References

  1. Marc H. Brown. Algorithm Animation. MIT Press, Cambridge, MA.,1988.
  2. Naps, Thomas L., JHAVE – Addressing the Need to Support Algorithm Visualization with Tools for Active Engagement. IEEE Computer Graphics and Applications. 2005.

Computer Science | Undergraduate

UG_CSC_ECKARTDynamically Maximizing the Performance of Large Data Transfer Over Dedicated Network Links

Ben Eckart
Faculty Research Advisor: Dr. Xubin He (Electrical and Computer Engineering)

New networks are emerging for the purpose of transmitting large amounts of scientific data among research institutions quickly and reliably [1]. These networks only marginally resemble the characteristics of the Internet, rendering the established Internet protocols ineffective. Recent methods have been developed to circumvent these problems, including new protocols which implement both reliable (TCP) and unreliable (UDP) data transfer algorithms [2]–[6]. Building faster networks and better protocols, however, does not necessarily result in better performance when the end-systems involved are unable to support such speeds. It is therefore necessary to build a protocol adaptive the performance of each system. This research develops such a protocol, Performance Adaptive UDP (PA-UDP), which aims to dynamically maximize performance under many system environments. A mathematical model and related algorithms are proposed that describe the theoretical basis behind effective buffer and CPU management. A prototype based on the PA-UDP architecture is implemented by monitoring the hosts during the data reception period and adjusting to the theoretically optimal rate. Experiments show that PA-UDP outperforms other high-speed protocols.

References

  1. N. S. V. Rao, W. R. Wing, S. M. Carter, and Q. Wu, “Ultrascience net: network testbed for large-scale science applications,” Communications Magazine, IEEE, vol. 43, no. 11, pp. S12–S17, 2005. [Online]. Available: http://ieeexplore.ieee.org/xpls/abs all.jsp?arnumber=1541694
  2. M. Goutelle, Y. Gu, and E. He, “A survey of transport protocols other than standard tcp,” 2004. [Online]. Available: citeseer.ist.psu.edu/he05survey.html
  3. R. L. Grossman, M. Mazzucco, H. Sivakumar, Y. Pan, and Q. Zhang, “Simple available bandwidth utilization library for high-speed wide area networks,” J. Supercomput., vol. 34, no. 3, pp. 231–242, 2005.
  4. Y. Gu and R. L. Grossman, “Udt: Udp-based data transfer for high-speed wide area networks,” Comput. Networks, vol. 51, no. 7, pp. 1777–1799, 2007.
  5. E. He, J. Leigh, O. T. Yu, and T. A. DeFanti, “Reliable blast UDP: Predictable high performance bulk data transfer,” in CLUSTER. IEEE Computer Society, 2002, pp. 317–324. [Online]. Available: http://csdl.computer.org/
  6. M. Meiss. Tsunami: A high-speed rate-controlled protocol for file transfer. [Online]. Available: www.evl.uic.edu/eric/ atp/TSUNAMI.pdf/

Earth Sciences | Undergraduate

UG_ES_KIMBRELLComparison of Fluid Characteristics from a Fault Zone and Marginal Foreland Basin

Phillip Derryberry and James Kimbrell
Faculty Research Advisor: Dr. Michael Harrison

UG_ES_DERRYBERRYCalcite veins from the Sequatchie Valley Thrust zone in middle Tennessee were collected to characterize the geochemistry and temperature of fluids associated with Alleghanian deformation. Specifically, fluid inclusions within the calcite veins were analyzed with a USGS-style heating and cooling stage to assess the temperature of homogenization (TH) and the last-ice melting temperature (TM). For veins collected from the Bangor Limestone next to the fault zone, the TH ranges from 55°-205° C and shows a bimodal distribution with modes of 60° C and 120° C. Veins collected from Gordonsville, TN ~110 km to the northwest also show a bimodal distribution of TH, but with modes of 105° C and 120° C. For the TM, the Bangor samples show a mode of 1.5° C whereas the Gordonsville samples show a mode of -18° C, suggesting different fluid sources. Hydrocarbons were detected in the inclusions from both sample sites.

Mathematics (Graduate)

GRAD_MATH_NGUFORNumerical Simulation of Groundwater Flow

Che Ngufor
Faculty Research Advisor: Dr. Sabine Le Borne

The goal of this research is to develop effective and efficient iterative solvers for linear problems arising from the discretization of equations governing the flow of groundwater in porous media. We approximate the actual groundwater system by a mathematical model and a computer model numerically solves the mathematical equations. The simulation is performed by sequential decoupling of the flow equation through the Darcy equation producing a dual mixed system. An efficient implementation of a discretization based on the lowest order Raviart-Thomas mixed finite elements technique leads to a saddle point system. Two methods are implemented for solving the saddle point system to yield the unknown velocities and pressures: (1) Using direct linear solvers like MATLAB, (2) using a new and efficient iterative solver we have developed based on the so-called hierarchical matrices. We then visualize the flow field and distribution of heads for both simple and complex geological formations.

Mathematics (Undergraduate)

UG_MATH_WESTRICHDomain Triangulation to Approximate a 2-Dimensional Disk

Quinton Westrich
Faculty Research Advisor: Dr. Sabine Le Borne

In order to run computer simulations which model the dynamics of fluids inside a shape, called a domain, the first step is to program the domain. In practice, we approximate the boundary of the domain with a polygon and then divide the interior of the polygon up into simpler shapes, such as triangles in 2D and tetrahedra in 3D---a process is called triangulation. Many objects we use daily, such as water pipes, engine pistons, and hoses, are nearly circular in two of their dimensions. My project is the triangulation of a 2D disk. Written in the C language, our code arranges triangles so that symmetries simplify and speed up storage and access of the grid points. Numerical data are presented which illustrate this. The next step will be the incorporation of this 2D disk into 3D codes for a wider range of applications.

Exceptional Learning (Ph.D.)

GRAD_ED_CHITIYOPeer Influences, Athletics, and Factors of Freshmen College Choice

George Chitiyo
Faculty Research Advisor: Dr. David Larimore

This study was conducted at a four year public university in the south eastern United States during the spring 2007 semester. Data were collected from a sample of 216 freshmen, 78 of whom were athletes. The overall response rate for the survey was 76%. A survey instrument was administered to investigate factors that influenced the freshmen students’ college choice, especially peer influences and athletics. A factor analysis was conducted in addition to descriptive statistics. Overall, the most important variables influencing the college choice of high school graduates were those associated with the factor named institutional image. The other factors are: peer influences, high school counselors and teachers, athletic factors, family influence, and spiritual guidance at the university. These factors collectively accounted for 77.3% of the variance in college choice.

GRAD_ED_ZHANGEfficacy of Peer-Mediation for Promoting Social Interactions Among Young Children with Autism

Jie Zhang
Faculty Research Advisor: Dr. John J. Wheeler

The purpose of this research was to investigate the efficacy of peer-mediations for promoting social interactions among young children under 8 years of age diagnosed with autism. A meta-analysis using single-subject studies was conducted with 45 studies from 19 journals between 1977 and 2006. The efficacy of the interventions was analyzed according to the variables that may affect the interventions, including the target children’s characteristics, interventionists’ characteristics, and intervention features. Inter-rater reliability was determined through double-coding the variables by the researcher’s doctoral advisor. Allison and Gorman’s (1993) method was used to calculate the effect sizes in order to take trend into account. One-sample t test was used to determine whether the overall effect sizes were significantly different from zero. One-way ANOVA, independent-samples t test, or Tukey’s post hoc test were used to compare each effect size within every variable to see whether there was any significant difference.

References

  1. Allison, D. B., & Gorman, B. S. (1993). Calculating effect sizes for meta-analysis: The case of the single case. Behavioral Research Theory. 31 (6), 621-631.

Chemical Engineering | Graduate

A Novel Monte-Carlo Strategy for Evaluating Cathode Materials for Lithium Ion Batteries

Vinten D. Diwakar
Faculty Research Advisor: Dr. Venkat Subramanian
Collaborator: Dr. Harinipriya Seshadri (Chemical Engineering)

A novel simulation strategy is formulated to study the performance of cathode materials in Li-ion batteries. The methodology1 takes into account both micro scale properties and macro scale properties. For example, diffusion of spherical electrode particle within the cathode and solvation effects, diffusion coefficients, concentration gradient to determine the diffusion of Li+ within the separator. The electrode particles move in each step to its nearest neighbor distance, employing the random number condition ir(j)>=exp(-dLi1/ds), where ‘ir’ represents the random number, dLi1 is the nearest neighbor distance for Li+ in the absence of solvent and ds being the thickness of the solid phase. The second random number criterion is ir(j)>=exp(-dLi1/ds2), dLi1 being the nearest neighbor distance Li+ can move in the presence of solvent and ds2 being the thickness of the separator. The discharge behavior for LiCoO2 and LiFePO4 as cathode materials is in quantitative agreement with existing literature2,3.

References

  1. 1. Performance characteristics of cathode materials for Lithium Ion batteries – A novel Monte Carlo strategy, H. Seshadri, V. D. Diwakar, and V. Subramanian, Submitted to Journal of the Electrochemical Society
  2. 2. Efficient macro-micro scale coupled modeling of batteries, V. Subramanian, V. D. Diwakar and D. Tapriyal, J. Electrochem. Soc., 152, A2002 (2005)
  3. 3. Discharge Model for the Lithium Iron-Phosphate Electrode, V. Srinivasan, and J. Newman, J. Electrochem. Soc., 151, A1517 (2004)

GRAD_CHEME_KANNANKinetics of Thermal Decompostion of Expanded Polystyrene (EPS)

Pravin Kannan
Faculty Research Advisors: Dr. Joseph J. Biernacki and Dr. Donald P. Visco, Jr.

The characteristics of thermal decomposition of expanded polystyrene (EPS) foams was studied in various gaseous environments, both oxidizing and non-oxidizing, over a narrow range of heating rates between 1 and 30 K/min using non-isothermal thermo gravimetric analysis (TGA). A modified integral-optimization technique was developed for multiple rate-controlling decomposition reactions, and results from kinetic data analysis shows that the activation energy of EPS foam decomposition in air is much less than any non-oxidizing environment, including nitrogen, helium and argon. Furthermore, qualitative mass spectrometric studies of EPS pyrolysis gases revealed the differences in EPS foam decomposition mechanism between various gaseous environments.

Mathematical Modeling of Discharge Behavior of Cathode Materials in Li-Ion Batteries

Uday S. Kasavajjula
Faculty Research Advisors: Dr. Pedro E. Arce and Dr. Chunsheng Wang (now at U of Maryland)

Improving the rate capability of LiFePO4 is a critical issue for commercialization of Li-ion batteries in hybrid electric vehicles and battery electric vehicles. In this study, the discharge kinetics of LiFePO4 electrodes for Li-ion batteries were investigated by developing a novel mathematical model. The model is based on the theory of mixed mode phase transformation and it assumes that the phase transformation is controlled by both Li chemical diffusion and interface mobility. The discharge model was validated by comparing the model discharge curves with the experimental discharge curves of various LiFePO4 samples from industry at different current densities. By using the validated model as a tool, effects of phase transformation, chemical diffusion, solid solution range, volume change and particle size on rate capability were determined and analyzed. The model developed here is applicable for any ion insertion electrode with a phase transformation (such as Li4Ti5O12 in Li-ion battery and metal-hydride electrodes in Ni/MH batteries).

GRAD_CHEME_PUTTAGUNTACharacterization of Volatile Organic Compounds (VOCs) in Comerical Kitchen Exhaust Emissions

Rupesh K Puttagunta
Faculty Research Advisor: Dr. Pedro E. Arce
Collaborators: Dr. Dennis B. George and Dr. Martha J. M. Wells (Center for the Management, Utilization, and Protection of Water Resources)

Commercial cooking operations are major source of particulate matter and volatile organic compound concentrations in urban areas. Particulate matter (

References

  1. EPA Compendium Method TO-17.
  2. Hildemann, L.M, Cass, G. R., and Markowski, G. R., 1989. “A Dilution Stack Sampler for Collection of Organic Aerosol Emissions: Design, Characterization and Field Tests” Aerosol. Sci. Technol. 10,193-204.
  3. Hildemann, L.M, Markowski, G. R., and Cass, G. R., 1991. “Chemical Composition of Emissions from Urban Sources of Fine Organic Aerosol.” Environ. Sci. Technol. 25, 744-759.

GRAD_CHEME_XIEThe Effect of Fine Inert Particles on Portland Cement Hydration Kinetics

Tiantian Xie
Faculty Research Advisor: Dr. Joseph J. Biernacki

The chemical reactions that occur during the early stages of portland cement hydration are complicated and the basic mechanisms yet debated. Furthering the complexity, modern cement systems incorporate fine admixtures such as slag, fly ash and silica fume. These also actively participate in the reaction process. To study the early stage hydration kinetics and the effect of additive particles, model systems containing inert particles (silicon carbide) were used. Samples containing particles in the amount of 30% inert material and 70% portland cement with a 0.35 water-to-cementitious ratio were investigated. The resulting specific heat of hydration was determined using isothermal calorimetry. Surprisingly fine “inert particles” accelerate the early stage hydration likely by providing surface areas for the nucleation and growth of products.

Chemical Engineering | Undergraduate

Novel Corticosteroid Development Via I-QSAR with Signature

Joshua D. Jackson
Faculty Research Advisor: Dr. Donald P. Visco

The research discussed here involves the development of a class of preventative asthma medications named corticosteroids. Corticosteroids such as hydrocortisone have commonly been the therapy of choice where an anti-inflammatory or immunosuppressive treatment is required. The focus of this research is to develop novel corticosteroids that are highly selective toward the lungs and are promptly removed from the body when exposed to the main circulation. We look to use the Inverse-Quantitative Structure-Activity Relationship (I-QSAR) algorithm with Signature to generate new drugs based upon the structures and corresponding activities of previously studied corticosteroids. I-QSAR explores possible combinations of atom connectivity, and structural filters are used to predict and collect the best candidates for further study. Our work currently focuses upon filtering the solutions generated from the inverse problem, leaving a database possessing only characteristics such as high receptor binding affinity, high systemic clearance, high plasma protein binding, and low oral bioavailability.

UG_CHEME_THOMPSONThermally Responsive Microparticle Gel Electrophoresis

Jeff Thompson
Faculty Research Advisors: Dr. Holly Stretz and Dr. Pedro E. Arce

Nanocomposite gels for drug delivery and bioseparations of proteins or DNA hold great potential. These materials feature, for example, nano or microparticles embedded in the gel structure that creates a thermo-sensitive and composite polymer with different and unique transport properties. The synthesis and characterization of poly(N-isopropyl acrylamide) thermally responsive particles as well as formation of the gel composites are described. The particles are synthesized with a precipitation polymerization crosslinking reaction and subsequently inserted into polyacrylamide gels[1]. In addition, electrophoresis runs are used to test the transport of proteins through the composite. Both UV and visual characterization are used to determine and compare the transport (i.e. mobility and dispersion) characteristics of the new gels with standard gels in the electrophoresis runs. A composite of one percent by mass PNIPAM and four percent acrylamide offers separations which are not available for five percent acrylamide concentration using albumin markers.

  1. St. John, Ashlee, Victor Breedveld, L. Andrew Lyon “Phase Behavior in Highly Concentrated Assemblies of Microgels with Soft Repulsive Interaction Potentials” Journal of Physical Chemistry. April 30, 2007.

Civil and Environmental Engineering (Graduate)

GRAD_CEE_TANGModeling the Hydrologically-Relevant Features of Uncertainty of NASA's High Resolution Precipitation Products for Advancing Global Applications Over Ungauged Regions

Ling Tang
Faculty Research Advisor: Dr. Faisal Hossain

In the post 2013 era of the NASA’s Global Precipitation Measurement (GPM) mission, high resolution precipitation products (HRPP) from satellites will become increasingly common for various global hydrologic applications overland (such as flood detection using distributed models). For advancing the application of these datasets, the associated uncertainty information will therefore be critical for users to understand the realistic limits to which these HRPPs can be applied over an ungauged region. However, this represents a paradox. Satellite rainfall uncertainty estimation requires ground validation (GV) precipitation data. On the other hand, satellite data will be most useful over ungauged regions in the developing world that are lacking in GV data. The primary objective of this project is therefore to reconcile this paradox with the motivation to further unleash the potential of NASA’s HRPPs for the developing world. Two important science questions are hoped to be answered through this project as follows. 1. How much climatologic classification of error regime is possible for characterizing uncertainty of NASA’s HRPPs? 2. If “error” is defined on the basis of ground validation (GV) data, then how can uncertainty be estimated for NASA’s global rainfall data products without the need for extensive GV data?

Civil and Environmental Engineering | Undergraduate

UG_CEE_SMITHExpansion of Cementitious Mortars Due to Delayed Ettringite Formation

Lindsay Smith
Faculty Research Advisor: Dr. Benjamin Mohr

This research is aimed at investigating the mechanisms of delayed ettringite formation causing expansion in portland cement mortars. The formation of ettringite is a normally benign product of cement hydration that occurs at early ages. However, ettringite is increasingly observed in concretes that have been in service for many years. Often associated with the ettringite observation is cracking of concrete. It is well known that ettringite formation is an expansive reaction that may cause cracking. However, little is known about the mechanisms of late age ettringite formation, specifically how different processes can ultimately lead to the same result. The objectives of this research are: (1) to identify those cement composition and mix design factors that lead to macro-scale expansion; and (2) to evaluate the micro-scale chemical changes that occur in the microstructure during heat curing and subsequent storage.

Electrical and Computer Engineering | Graduate

GRAD_ECE_JAGANATHANBattery Charging Control Technique for Hybrid Electric Vehicle

Sharanya Jaganathan
Faculty Research Advisor: Dr. Wenzhong Gao

Environmental protection place restrictions on the emission of waste gases from the motor vehicle and motorcycle thus accelerating the development of electric vehicles and hybrid electric vehicles driven by electricity. At present there are a lot of technical problems for the batteries of EV and HEV such as life cycle of battery, convenience of charging, fast charging, promotion of energy density, performance and low cost. The objective here is to develop a novel control strategy and a low cost high performance power electronic device for charging the battery. The work will also include comparing different charging methods to study their effects on the overall energy efficiency. The charging technique will be implemented in Simulink/Matlab or equivalent software. Also the simulation results will be validated with the experimental set up to check the effectiveness of the technique.

SAG Monitoring Using Global Positioning System

Shalini Sushmitha Komaragiri
Faculty Research Advisor: Dr. Satish Mahajan

A new method to measure the physical sag of an overhead conductor line involves differential global positioning technique [1], [3]. The method relies on the information received from the GPS satellites and is capable of measuring sag to an accuracy of approximately 2 cm using a commercially available LEICA GPS System [2]. However, the overall cost of the system (~ $ 50 K) is somewhat high [2]. Proposed method of using three or more cheaper GARMIN GPS devices to measure sag, could be a cost effective alternative to the expensive LEICA GPS System. The GARMIN GPS devices when placed on the same horizontal plane gave an accuracy of about ±8 meters with reference to LEICA GPS System. Therefore, various factors affecting the accuracy of cheaper GARMIN GPS devices and various mathematical algorithms for error correction are being investigated in this research.

References

  1. Chris Mensah – Bonsu; Ubaldo Fernandez Krekeler, Gerald Thomas Heidi, Yuri Hoverson; John Schilleci; Baj. A. Agarwal, “Application of the Global Positioning System to the Measurement of Overhead Power Transmission Conductor Sag”, IEEE Transactions on Power Delivery, Vol. 17, No. 1. January 2002, pp 273 – 278
  2. Mahesh Singareddy, “Sag Measurement using Differential Global Positioning System” Tennessee Tech University, August 2007.
  3. Chris Mensah – Bonsu, “Instrumentation and measurement of overhead conductor sag using the differential global positioning satellite system“, PhD Dissertation; Arizona State University, August 2000.

Enhanced Verdet Constant Via Quantum Dot Doped Glass Samples

Ganapathy Kumar
Faculty Research Advisor: Dr.Satish M. Mahajan

The Faraday Effect or rotation of plane polarized light in glass samples under the influence of an external magnetic field and the Faraday rotation angles is reported for SF¬-57, BK-7 and borosilicate type glasses. Doping the glass with quantum dots increases the electron confinement energies upon excitement and magnifies the phase difference between the right and left circularly polarized light thus enhancing the Faraday rotation angle and hence the Verdet constant for that material, which is dependent on wavelength and temperature, resulting in high magneto-optic effect. The measured Verdet constant values were 11.25 deg/T-cm, 2.67 deg/T-cm and 0.1295 deg/T-cm for undoped SF-57, BK-7 and borosilicate rods respectively and conform to literature [1][2][3][4]. The application of these types of glasses can be done to Magneto-Optic Current transformers (MOCTs), Optic fiber current sensors and highly sensitive current detectors [5][6].

References

  1. P.A.Williams, A.H.Rose, G.W.Day, T. E. Milner, and M. N. Deeter, “Temperature dependence of verdet constant in several diamagnetic glasses”, Applied Optics, vol. 30,no. 10,April 1991
  2. G.Li, M.G.Kong, G.R.Jones and J.W.Spencer,”Sensitivity Improvement of an Optical Current Sensor with Enhanced Faraday Rotation,” J.Lightw.Technol., vol. 15,no. 12, pp. 2246-2252, Dec.1997.
  3. A.Jain, J.Kumar, L.Li, F.Zhou and S.Tripathy,”A simple experiment for determining Verdet constants using alternating current magnetic fields”, Am.J.Physics. 67(8). pp. 714-717,1998
  4. J.H. Kratzer and J.Schroeder, “Magnetooptic properties of semiconductor quantum dots in glass composites”, Journal of Non-crystalline solids, vol.349,pp¬299-308,2004
  5. Sascha Liehr,”Optical Measurement of Current in Power Converters”, M.S.thesis, Dept.Elect.Eng., Royal Inst., Stockholm, Sweden,2006.

GRAD_ECE_GUDIPELLYDesign Optimization of a 35nm Independently-Double-Gated Flexfet SOI Transistor

Rama Satyanarayana Chintala, Himaja Reddy Moolamalla, Ken Modzelewski, and Nishanth Gudipelly (Pictured)
Faculty Research Advisor: Dr. Stephen A. Parke

Planar independently-double-gated Flexfet CMOS transistors have been developed, which exhibit strong dynamic threshold voltage control of 0.3-1.0 V\V. The Flexfet device incorporates a mid-gap MOSFET top gate self-aligned to an implanted silicon JFET bottom gate. Each transistor in a circuit may be connected in either single-gate (SG), double-gate (DG), or independent-double-gate (IDG) mode as needed to achieve ultra-low-power CMOS ICs.

A simple analytical dynamic threshold voltage model was developed and verified by using SILVACO ATLAS device simulation software. Design optimization of a 35nm independently-double-gated Flexfet Silicon-On-Insulator transistor with an ideal 1.0V\V dynamic threshold control of this device was achieved. The device used for simulation and the analytical threshold model developed are in 2D but a 3D complex model will also be developed. Since the threshold voltage of the device varies due to short channel effects at 35nm, optimization was done to overcome these effects.

References

  1. H.K Lim and J.G. Fossum, “Threshold Voltage of Thin-Film Silicon-On-Insulator (SOI) MOSFETS”, IEEE Trans. Electron Devices, 30, 1244-1251, 1983.
  2. Yuan Taur, “An Analytical Solution to a Double-gate MOSFET with Undoped Body”, IEEE Trans. Electron Devices, Vol.21, No. 5, 245-247, May 2000.
  3. Keunwoo Kim, J.G. Fossum, “Double-gate CMOS: Symmetrical-Versus Asymmetrical-Gate Devices”, IEEE trans. Electron Devices, Vol 48, No. 2, Feb 2001.
  4. Mark Lundstrom, Jing Guo, “Nanoscale Transistors: Device Physics, Modeling and Simulation”, Springer, New York, 2005.

GRAD_ECE_VANEGASHigh Voltage & High Current Laboratory - Implementation at Tennessee Technological University

Diego M. Robalino Vanegas
Faculty Research Advisor: Dr. Satish M. Mahajan

Electrical equipment suffers degradation due to long-term operation and eventual failures of the electrical system. The aim of this project is to provide an educational/research facility where High Voltage/High Power equipment were tested under conditions similar to those during real operation and emergency situations. Following the guidelines of highly recognized standards [1], [2], [3], [4], [5] & [6], the High Voltage (HV) & High Current (HC) Laboratory has been sequentially developed. The laboratory is capable of carrying out the condition assessment of electrical apparatus by means of DC (Direct Current) HV testing, Hot Spot Temperature (HST) measurement (via Fiber Optics and Thermocouples), HC Loading Set-up, Measurement and Protection Current Transformers Analysis, Tan , permittivity, capacitance & Power Factor measurement via Insulation Diagnostic Equipment, Dielectric Breakdown Test and On-line Dissolved Gas Analysis monitoring. This project greatly contributes to the development of research and academic opportunities for the TTU Electrical Engineering Department.

References

  1. IEEE Std 4-1995. IEEE Standard Techniques for High-Voltage Testing
  2. IEEE Std 1538-2000. IEEE Guide for Determination of Maximum Winding Temperature Rise in Liquid-Filled Transformers.
  3. IEEE Std C57.91-1995. IEEE Guide for Loading Mineral-Oil-Immersed Transformers
  4. IEEE Std C57.13-1993. IEEE Standard Requirements for Instrument Transformers
  5. ANSI/IEEE C57.104. IEEE Guide for the detection and Determination of Generated Gases in Oil-Immersed transformers and their relation to the serviceability of the equipment
  6. IEEE Std 510. IEEE Recommended Practices for Safety in High-Voltage and High-Power Testing.

Mechanical Engineering | Graduate

GRAD_ME_ANANTHARAJUPhase Field Modeling of Contact Angle Hysteresis in Sessile Drops

Neeharika Anantharaju
Faculty Research Advisor: Dr. Mahesh Panchagnula
Collaborator: Srikanth Vedantam (National University of Singapore)

Wetting on non-ideal surfaces is of great practical interest. Contact line behavior is an important parameter that attributes to understanding wettability. The presence of heterogeneities on a surface causes the pinning of the three-phase contact line in one of the many possible metastable states, resulting in contact angle hysteresis (CAH). CAH depends on the surface inhomogeneities, which are often random in size and position. The other factors like thermodynamic variables involved and the path followed makes quantifying the CAH challenging. Wetting of surfaces by sessile drops can thus be described as an interface phenomenon involving very steep changes at the contact line and is studied using a phase field model. The theory [1] uses a two dimensional non-conserved phase field variable to distinguish between wetted and non-wetted regions. The three-phase contact line tension is characterized by the gradient energy and CAH from the kinetic coefficient. A significant departure from the classical Cassie theory, arising due to the contact line pinning, is observed.

Reference

  1. Vedantam, S., and Panchagnula, M.V., Phase Field Modeling of Hysteresis in Sessile Drops. Physical Review Letters, 2007. 99(17).

GRAD_ME_NADKARNINumerical Analysis of Transient Temperature Distribution in a Current Transformer

Mahesh Nadkarni
Faculty Research Advisors: Dr. Jie Cui

Current Transformer (CT) is a device that transfers the electrical energy from one circuit to another through a shared magnetic field. In a CT, heat is generated because of the energy losses in the core, tank wall, primary and secondary windings. The performance of the current transformer is well indicated by the temperature distribution inside a CT. In this study, numerical analysis is performed to predict the temperature distribution inside a CT at every instant under different load conditions. It is found that the numerical results obtained were in good agreement with the experimental measurements. Thus, it is concluded that the numerical method can be a useful tool in a CT design and performance monitoring.

Mechanical Engineering | Undergraduate

UG_ME_GAHANDyamics of Liquid Marbles

Kenneth C. Gahan (Pictured) and Prasad S. Bhosale
Faculty Research Advisor: Dr. Mahesh Panchagnula (Mechanical Engineering) and Dr. Holly A. Stretz (Chemical Engineering)

Liquid marbles, which are water based liquids coated with a hydrophobic nanoparticulate substance resulting in small "marbles", are of interest to both chemical and mechanical engineers (1). This study is motivated by the proposition that liquid marbles can provide for a rapid, contamination-free transport mechanism of bio-fluids. The current research seeks to understand the unique manner in which liquid marbles behave under dynamical conditions. Under rolling motion, liquid marbles are observed to behave differently from solid spheres in that they accelerate quickly before settling to a terminal velocity, due to the damping effects of the liquid core (2).

References

  1. Properties of Liquid Marbles – Aussillous, P. and Quere, D. Proc. R. Sec. A 462, 973-999 (2006).
  2. Non-stick Water – Mahadevan, L. Nature 411, 895-896 (2001).

 

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