Engineering Commons^™

Virtualization In High-Performance Computing: An Analysis Of Physical And Virtual Node Performance, Glendon M. Jungels

Purdue Polytechnic Masters Theses

The process of virtualizing computing resources allows an organization to make more efficient use of it's resources. In addtion, this process enables flexibility that deployment on raw hardware does not. Virtualization, however, comes with a performance penalty. This study examines the performance of utilizing virtualization technology for use in high performance computing to determine the suitibility of using this technology. It makes use of a small (4 node) virtual cluster as well as a 4 node physical cluster. The impacts on input/output operation are examined as well as performance of each cluster using two widely utilized tools, NAS Parallel Benchmarks …

Drive-Amplitude-Modulation Atomic Force Microscopy: From Vacuum To Liquids, Miriam Jaafar, David Martinez-Martin, Mariano Cuenca, John Melcher, Arvind Raman, Julio Gomez-Herrero

Birck and NCN Publications

We introduce drive-amplitude-modulation atomic force microscopy as a dynamic mode with outstanding performance in all environments from vacuum to liquids. As with frequency modulation, the new mode follows a feedback scheme with two nested loops: The first keeps the cantilever oscillation amplitude constant by regulating the driving force, and the second uses the driving force as the feedback variable for topography. Additionally, a phase-locked loop can be used as a parallel feedback allowing separation of the conservative and nonconservative interactions. We describe the basis of this mode and present some examples of its performance in three different environments. Drive-amplutide modulation …

Control Of Absorption With Hyperbolic Metamaterials, T.U. Tumkur, Lei Gu, J.K. Kitur, Evgenii E. Narimanov, M.A. Noginov

Birck and NCN Publications

We show that absorption of thin dye-doped polymeric films can be tuned and enhanced ( nearly threefold) by metallic and lamellar metal-dielectric hyperbolic metamaterial substrates. The effect can be controlled by a combination of the substrate's geometry and composition. As the enhancement of absorption is sustained over large range of incidence angles, the demonstrated phenomenon can lead to a variety of important applications, including solar cell technology. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4703931]

Tunable Thermal Rectification In Graphene Nanoribbons Through Defect Engineering: A Molecular Dynamics Study, Yan Wang, Siyu Chen, Xiulin Ruan

Birck and NCN Publications

Using non-equilibrium molecular dynamics, we show that asymmetrically defected graphene nanoribbons (GNR) are promising thermal rectifiers. The optimum conditions for thermal rectification (TR) include low temperature, high temperature bias, similar to 1% concentration of single-vacancy or substitutional silicon defects, and a moderate partition of the pristine and defected regions. TR ratio of similar to 80% is found in a 14-nm long and 4-nm wide GNR at a temperature of 200 K and bias of 90 K, where heat conduction is in the ballistic regime since the bulk effective phonon mean-free-path is around 775 nm. As the GNR length increases towards …

Non-Equilibrium Green's Function Calculation For Gan-Based Terahertz-Quantum Cascade Laser Structures, H. Yasuda, T. Kubis, I. Hosako, K. Hirakawa

Birck and NCN Publications

We theoretically investigated GaN-based resonant phonon terahertz-quantum cascade laser (QCL) structures for possible high-temperature operation by using the non-equilibrium Green's function method. It was found that the GaN-based THz-QCL structures do not necessarily have a gain sufficient for lasing, even though the thermal backfilling and the thermally activated phonon scattering are effectively suppressed. The main reason for this is the broadening of the subband levels caused by a very strong interaction between electrons and longitudinal optical (LO) phonons in GaN. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704389]

Tuning Entanglement And Ergodicity In Two-Dimensional Spin Systems Using Impurities And Anisotropy, Gehad Sadiek, Qing Xu, Sabre Kais

Birck and NCN Publications

We consider the entanglement in a two-dimensional XY model in an external magnetic field h. The model consists of a set of seven localized spin-1/2 particles in a two-dimensional triangular lattice coupled through nearest-neighbor exchange interaction J. We examine the effect of single and double impurities in the system as well as the degree of anisotropy on the nearest-neighbor entanglement and ergodicity of the system. We have found that the entanglement of the system at the different degrees of anisotropy mimics that of the one-dimensional spin systems at the extremely small and large values of the parameter lambda = h/J. …

Sketching 3d Animation, Innfarn Yoo

Department of Computer Graphics Technology Degree Theses

This thesis presents a method for creating natural 3D animation based on sketches. Our method provides novice and professional sketchers an easy, fast, and intuitive way to create three dimensional animations by drawing sketches, enhanced by strokes, and joint trajectory or rotation curves. It also allows searching massive databases of 3D animation as an application for motion capture system and major animation software. We extract 2D skeletons from strokes and find similar motion sequences by comparing all the important pre-generated key poses in database. To give the system more hints, users can draw joint trajectory and rotations curves that are …

Room Temperature Deposition Of Alumina-Doped Zinc Oxide On Flexible Substrates By Direct Pulsed Laser Recrystallization, Martin Y. Zhang, Qiong Nian, Gary J. Cheng

Birck and NCN Publications

In this study, a method combining room temperature pulsed laser deposition (PLD) and direct pulsed laser recrystallization (DPLR) is introduced to deposit transparent conductive oxide (TCO) layer on low melting point flexible substrates. Alumina-doped zinc oxide (AZO), as one of the most promising TCO candidates, has now been widely used in solar cells. However, to achieve optimal, electrical, and optical properties of AZO on low melting point, flexible substrate is challenging. DPLR technique is a scalable, economic, and fast process to remove crystal defects and generate recrystallization at room temperature. It features selective processing by only heating up the TCO …

The Integration Of High-K Dielectric On Two-Dimensional Crystals By Atomic Layer Deposition, Han Liu, Kun Xu, Xujie Zhang, Peide Ye

Birck and NCN Publications

We investigate the integration of Al2O3 high-k dielectric on two-dimensional (2D) crystals of boron nitride (BN) and molybdenum disulfide (MoS2) by atomic layer deposition (ALD). We demonstrate the feasibility of direct ALD growth with trimethylaluminum and water as precursors on both 2D crystals. Through theoretical and experimental studies, we found that the initial ALD cycles play the critical role, during which physical adsorption dominates precursor adsorption at the crystal surface. We model the initial ALD growth stages at the 2D surface by analyzing Lennard-Jones potentials, which could guide future optimization of the ALD process on 2D crystals. (C) 2012 American …

Acoustic Emission Detection Of Metals And Alloys During Machining Operations, Jameson K. Nelson

Purdue Polytechnic Masters Theses

Nelson, Jameson K. M.S., Purdue University, May 2012. Acoustic Emission Detection of Metals and Alloys During Machining Operations. Major Professor: Rodney G. Handy.

Practical correlation between material deformation attributes and theoretical concepts of machining has proven difficult to attain. The purpose of this study was to further explore trends and relationships using acoustic emission detection of materials undergoing single-point lathe turning machine processes. The majority of machining experiments that incorporate acoustic emissions focuses on tool degradation for the purposes of optimizing consumables required to manufacture mechanical devices. Experiments were implemented varying recording location, mechanical barrier condition, and machine parameters. The …

Exploration Of The Limits To Mobility In Two-Dimensional Hole Systems In Gaas/Algaas Quantum Wells, J.D. Watson, S. Mondal, G. Gardner, Gabor A. Csathy, Michael J. Manfra

Birck and NCN Publications

We report on the growth and electrical characterization of a series of two-dimensional hole systems (2DHSs) used to study the density dependence of low temperature mobility in 20-nm GaAs/AlGaAs quantum wells. The hole density was controlled by changing the Al mole fraction and the setback of the delta-doping layer. We varied the density over a range from 1.8 x 10(10) cm(-2) to 1.9 x 10(11) cm(-2) finding a nonmonotonic dependence of mobility on density at T = 0.3 K. Surprisingly, a peak mobility of 2.3 x 10(6) cm(2)/Vs was measured at a density of 6.5 x 10(10) cm(-2), with further …

Interface Barriers At The Interfaces Of Polar Gaas(111) Faces With Al2o3, H.Y. Chou, E. O'Connor, P.K. Hurley, V.V. Afanas'ev, M. Houssa, A. Stesmans, Peide Ye, S.B. Newcomb

Birck and NCN Publications

Internal photoemission measurements of barriers for electrons at interfaces between GaAs(111) and atomic-layer deposited Al2O3 indicate that changing the GaAs polar crystal face orientation from the Ga-terminated (111)A to the As-terminated (111)B has no effect on the barrier height and remains the same as at the non-polar GaAs(100)/Al2O3 interface. Moreover, the presence of native oxide on GaAs(111) or passivation of this surface with sulphur also have no measurable influence on the GaAs(111)/Al2O3 barrier. These results suggest that the orientation and composition-sensitive surface dipoles conventionally observed at GaAs surfaces are effectively compensated at GaAs/oxide interfaces. (C) 2012 American Institute of Physics. …

Magnetoplasmon Resonance In A Two-Dimensional Electron System Driven Into A Zero-Resistance State, A. T. Hatke, M. A. Zudov, J. D. Watson, Michael J. Manfra

Birck and NCN Publications

We report on a very strong, and a rather sharp, photoresistance peak originating from a dimensional magnetoplasmon resonance (MPR) in a high-mobility GaAs/AlGaAs quantum well driven by microwave radiation into a zero-resistance state (ZRS). The analysis of the MPR signal reveals a negative background, providing experimental evidence for the concept of absolute negative resistance associated with the ZRS. When the system is further subject to a dc field, the maxima of microwave-induced resistance oscillations decay away and the system reveals a state with close-to-zero differential resistance. The MPR peak, on the other hand, remains essentially unchanged, indicating robust Ohmic behavior …

Whole-Genome Resequencing Of Two Elite Sires For The Detection Of Haplotypes Under Selection In Dairy Cattle Supporting Information, Denis M. Larkin, Hans D. Daetwyler, Alvaro G. Hernandez, Chris L. Wright, Lorie A. Hetrick, Lisa Boucek, Sharon Bachman, Jyothi Thimmapuram

Cyber Center Publications

Using a combination of whole-genome resequencing and high-density genotyping arrays, genome-wide haplotypes were reconstructed for two of the most important bulls in the history of the dairy cattle industry, Pawnee Farm Arlinda Chief (“Chief”) and his son Walkway Chief Mark (“Mark”), each accounting for ∼7% of all current genomes. We aligned 20.5 Gbp (∼7.3× coverage) and 37.9 Gbp (∼13.5× coverage) of the Chief and Mark genomic sequences, respectively. More than 1.3 million high-quality SNPs were detected in Chief and Mark sequences. The genome-wide haplotypes inherited by Mark from Chief were reconstructed using ∼1 million informative SNPs. Comparison of a set …

Design Of Three-Well Indirect Pumping Terahertz Quantum Cascade Lasers For High Optical Gain Based On Nonequilibrium Green's Function Analysis, Tao Liu, Tillmann Kubis, Qi Jie Wang, Gerhard Klimeck

Birck and NCN Publications

The nonequilibrium Green's function approach is applied to the design of three-well indirect pumping terahertz (THz) quantum cascade lasers (QCLs) based on a resonant phonon depopulation scheme. The effects of the anticrossing of the injector states and the dipole matrix element of the laser levels on the optical gain of THz QCLs are studied. The results show that a design that results in a more pronounced anticrossing of the injector states will achieve a higher optical gain in the indirect pumping scheme compared to the traditional resonant-tunneling injection scheme. This offers in general a more efficient coherent resonant-tunneling transport of …

Enhanced Optical Nonlinearity In Beta-Agvo3 Nanobelts On Decoration With Ag Nanoparticles, Manas R. Parida, C. Vijayan, Chandra Sekhar Rout, C.S. Suchand Sandeep, Reji Philip

Birck and NCN Publications

This paper reports on the optical nonlinearity of beta-AgVO3 nanobelts and the modification in the physical mechanisms of nonlinear response on decorating with silver nanoparticles. The nanobelts are synthesized by a hydrothermal technique and characterized using SEM, TEM, and XRD etc. The nanobelts are found to exhibit large nonlinear optical absorption as revealed by open Z-scan measurements using 5 ns laser pulses at 532 nm. Nonlinearity appears to be arising from a combination of mechanisms of two photon absorption and saturable absorption (SA). Decoration with Ag nanoparticles is found to enhance the saturable absorption and alter the coefficient of nonlinear …

Incorporating Reverse Engineering Methodology Into Engineering Curricula, Trevor Wanamaker

Purdue Polytechnic Masters Theses

Wanamaker, Trevor W., M.S., Purdue University, May 2012. Incorporating Reverse Engineering Methodology into Engineering Curricula. Major Professor: Craig L. Miller.

Using a qualitative research approach, this study investigated the thoughts and feelings of students regarding the question, “what factors need to be considered when Reverse Engineering (RE) methodology is incorporated into engineering curricula?” The participants in the study were from the Introduction to Graphics for Manufacturing course at the West Lafayette campus of Purdue University. An RE survey was given to the all students enrolled in the course and 10 select students were given the opportunity to use a 3D …

Theory Of Charging And Charge Transport In “Intermediate” Thickness Dielectrics And Its Implications For Characterization And Reliability, Sambit Palit, Muhammad A. Alam

Birck and NCN Publications

Thin film dielectrics have broad applications, and the performance degradation due to charge trapping in these thin films is an important and pervasive reliability concern. It has been presumed since the 1960s that current transport in intermediate-thickness (IT) oxides (∼10–100 nm) can be described by Frenkel-Poole (FP) conduction (originally developed for ∼mm-thick films) and algorithms based on the FP theory can be used to extract defect energy levels and charging-limited lifetime. In this paper, we review the published results to show that the presumption of FP-dominated current in IT oxides is incorrect, and therefore, the methods to extract trap-depths to …

Dynamics Of Surface-Coupled Microcantilevers In Force Modulation Atomic Force Microscopy - Magnetic Vs. Dither Piezo Excitation, Xin Xu, Marisol Koslowski, Arvind Raman

Birck and NCN Publications

Force modulation atomic force microscopy is widely used for mapping the nanoscale mechanical properties of heterogeneous or composite materials using low frequency excitation of a microcantilever scanning the surface. Here we show that the excitation mode - magnetic or dither piezo, has a major influence on the surface-coupled microcantilever dynamics. Not only is the observed material property contrast inverted between these excitation modes but also the frequency response of the surface-coupled cantilever in the magnetic mode is near-ideal with a clear resonance peak and little phase distortion thus enabling quantitative mapping of the local mechanical properties. (C) 2012 American Institute …

2012 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for local agency officials and employees responsible for Indiana’s local road infrastructure.

Level Of Effort Of Indiana Counties, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This report shows the level of effort of Indiana counties for which an operations report was available. It is based on 2010 calendar year information retrieved from the Indiana Tax Handbook, Comprehensive Annual Financial Report, County Operations Reports and information provided from the Indiana State Auditor’s office regarding County Distributions.

2010 Statewide Bridge Sufficiency Rating Report, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The main purpose of this report is to provide bridge sufficiency rating information for the bridges in each county. This information results from the data generated by the National Bridge Inspection Standards (NBIS) program authorized by the 1968 Federal Aid Highway Act.

Collective Nature Of The Reentrant Integer Quantum Hall States In The Second Landau Level, N. Deng, A. Kumar, Michael J. Manfra, L. N. Pfeiffer, K. W. West, Gabor A. Csathy

Birck and NCN Publications

We report an unexpected sharp peak in the temperature dependence of the magnetoresistance of the reentrant integer quantum Hall states in the second Landau level. This peak defines the onset temperature of these states. We find that in different spin branches the onset temperatures of the reentrant states scale with the Coulomb energy. This scaling provides direct evidence that Coulomb interactions play an important role in the formation of these reentrant states evincing their collective nature.

Direct Measurements And Numerical Simulations Of Gas Charging In Microelectromechanical System Capacitive Switches, A. Venkattraman, A. Garg, Dimitrios Peroulis, Alina A. Alexeenko

Birck and NCN Publications

Gas breakdown in microelectromechanical system capacitive switches is demonstrated using high resolution current measurements and by particle-in-cell/Monte Carlo collision (PIC/MCC) simulations. Measurements show an electric current through a 3 mu m air gap increasing exponentially with voltage, starting at 60 V. PIC/MCC simulations with Fowler-Nordheim [Proc. R. Soc. London, Ser. A 119, 173 (1928)] field emission reveal self-sustained discharges with significant ion enhancement and a positive space charge. The effective ion-enhanced field emission coefficient increases with voltage up to about 0.3 with an electron avalanche occurring at 159 V. The measurements and simulations demonstrate a charging mechanism for microswitches consistent …

Photonically Enhanced Flow Boiling In A Channel Coated With Carbon Nanotubes, Arun S. Kousalya, Chad N. Hunter, Shawn A. Putnam, Timothy Miller, Timothy S. Fisher

Birck and NCN Publications

High heat dissipation rates are enabled by multi-phase cooling schemes owing to latent heat uptake. We demonstrate enhanced flow boiling from a carbon nanotube (CNT)-coated copper surface exposed to low-intensity ultraviolet (UV)-visible excitation. Compared to non-illuminated results, the average boiling incipience temperature decreased by 4.6 degrees C and heat transfer coefficients improved by 41.5% with light exposure. These improved results are attributed to augmented hydrophilicity upon exposure to UV light and possible nanoscale opto-thermal effects, and suggest opportunities for active temperature control of temperature-sensitive devices. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681594]

Threshold Of Hierarchical Percolating Systems, Jiantong Li, Biswajit Ray, Muhammad Alam, Mikael Ostling

Birck and NCN Publications

Many modern nanostructured materials and doped polymers are morphologically too complex to be interpreted by classical percolation theory. Here, we develop the concept of a hierarchical percolating (percolation-within-percolation) system to describe such complex materials and illustrate how to generalize the conventional percolation to double-level percolation. Based on Monte Carlo simulations, we find that the double-level percolation threshold is close to, but definitely larger than, the product of the local percolation thresholds for the two enclosed single-level systems. The deviation may offer alternative insights into physics concerning infinite clusters and open up new research directions for percolation theory

Power Handling Of Electrostatic Mems Evanescent-Mode (Eva) Tunable Bandpass Filters, Xiaoguang Liu, Linda P.B. Katehi, William J. Chappell, Dimitrios Peroulis

Birck and NCN Publications

This paper presents the first theoretical and experimental study on the power handling capabilities of electrostatically tunable MEMS cavity filters. The theoretical analysis indicates that the frequency-dependent RF voltage inside a narrow-band filter may play an important role in the generation of electromechanical nonlinearities such as frequency response distortion, frequency shift, and bifurcation instability. This analysis also reveals that the filter's power handling capability is dependent on several critical factors, including the capacitive gap, stiffness of the diaphragm actuator, and the overall quality factor (Q) of the evanescent-mode (EVA) resonators. A nonlinear computer-aided design (CAD) model is proposed as a …

An All-Silicon Passive Optical Diode, Li Fan, Jian Wang, Leo T. Varghese, Hao Shen, Ben Niu, Yi Xuan, Andrew M. Weiner, Minghao Qi

Birck and NCN Publications

A passive optical diode effect would be useful for on-chip optical information processing but has been difficult to achieve. Using a method based on optical nonlinearity, we demonstrate a forward-backward transmission ratio of up to 28 decibels within telecommunication wavelengths. Our device, which uses two silicon rings 5 micrometers in radius, is passive yet maintains optical nonreciprocity for a broad range of input power levels, and it performs equally well even if the backward input power is higher than the forward input. The silicon optical diode is ultracompact and is compatible with current complementary metal-oxide semiconductor processing.

Size Effects In Niti From Density Functional Theory Calculations, Karthik Guda Vishnu, Alejandro Strachan

Birck and NCN Publications

We use density functional theory to characterize how size affects the relative stability of thin NiTi slabs of different crystal structures and its implication on the martensitic phase transition that governs shape memory. We calculate the surface energies of B2' phase (austenite), B19 (orthorhombic), B19' (martensite), and a body-centered orthorhombic phase, the theoretically predicted ground state. We find that (110)(B2) surfaces with in-plane atomic displacements stabilize the austenite phase with respect to B19' and BCO; thus, slabs with such orientations are predicted to exhibit a decrease in martensite transition temperature with decreasing thickness. Our calculations predict a critical thickness of …

Resolving Structure And Mechanical Properties At The Nanoscale Of Viruses With Frequency Modulation Atomic Force Microscopy, David Martinez-Martin, Carolina Carrasco, Mercedes Hernando-Perez, Pedro J. De Pablo, Julio Gomez-Herrero, Rebeca Perez, Mauricio G. Mateu, Jose L. Carrascosa, Daniel Kiracofe, John Melcher, Arvind Raman

Birck and NCN Publications

Structural Biology (SB) techniques are particularly successful in solving virus structures. Taking advantage of the symmetries, a heavy averaging on the data of a large number of specimens, results in an accurate determination of the structure of the sample. However, these techniques do not provide true single molecule information of viruses in physiological conditions. To answer many fundamental questions about the quickly expanding physical virology it is important to develop techniques with the capability to reach nanometer scale resolution on both structure and physical properties of individual molecules in physiological conditions. Atomic force microscopy (AFM) fulfills these requirements providing images …