Engineering Commons^™

Metal-Oxide-Semiconductor Field-Effect Transistors On Gaas (111)A Surface With Atomic-Layer-Deposited Al2o3 As Gate Dielectrics, Xu M, Y Q. Wu, O Koybasi, T Shen, P. D. Ye

Birck and NCN Publications

GaAs inversion-mode metal-oxide-semiconductor field-effect transistors (MOSFETs) with atomic-layer-deposited Al2O3 as gate dielectrics are fabricated on (111)A and (100) surfaces. With the same channel length of 0.75 mu m, the maximum drain current of 15 mA/mm on n-channel MOSFET is obtained on (111)A surface, in great contrast to only 1 mu A/mm on (100) surface. For p-channel MOSFETs, maximum drain currents of 0.17 mA/mm and 0.8 mA/mm are obtained on (111)A and (100) surfaces, respectively. An empirical model is proposed to correlate the experimental observation with the existing III-V MOS theories.

Device Considerations For Development Of Conductance-Based Biosensors, Kangho Lee, Pradeep R. Nair, Adina Scott, Muhammad A. Alam, David B. Janes

Birck and NCN Publications

Design and fabrication of electronic biosensors based on field-effect-transistor (FET) devices require understanding of interactions between semiconductor surfaces and organic biomolecules. From this perspective, we review practical considerations for electronic biosensors with emphasis on molecular passivation effects on FET device characteristics upon immobilization of organic molecules and an electrostatic model for FET-based biosensors.

High Efficiency Excitation Of Plasmonic Waveguides With Vertically Integrated Resonant Bowtie Apertures, Edward C. Kinzel, Xianfan Xu

Birck and NCN Publications

In recent years, many nanophotonic devices have been developed. Much attention has been given to the waveguides carrying surface plasmon polariton modes with subwavelength confinement and long propagation length. However, coupling far field light into a nano structure is a significant challenge. In this work, we present an architecture that enables high efficiency excitation of nanoscale waveguides in the direction normal to the waveguide. Our approach employs a bowtie aperture to provide both field confinement and high transmission efficiency. More than six times the power incident on the open area of the bowtie aperture can be coupled into the waveguide. …

Resonant Oscillation Of Misch-Metal Atoms In Filled Skutterudites, Yaguo Wang, Xianfan Xu, Jihui Yang

Birck and NCN Publications

We investigate vibrational behaviors in misch-metal filled antimony skutterudites in the time domain. At higher filling ratios of guest atoms, the vibration frequency approaches that of the cage structure and the amplitude becomes stronger. Furthermore, the reduction of lattice thermal conductivity over a wide temperature range can be explained using the measured resonant vibrational frequency. These findings reveal that the reduction of the lattice thermal conductivity is a result of scattering of acoustic phonons due to the resonant interaction between guest atoms and lattice phonons.

Real Space First-Principles Derived Semiempirical Pseudopotentials Applied To Tunneling Magnetoresistance, Kirk Huw Bevan, Tony Low, H Guo

Birck and NCN Publications

We present a real space density functional theory localized basis set semiempirical pseudopotential (SEP) approach. The method is applied to iron and magnesium oxide, where bulk SEP and local spin density approximation band structure calculations are shown to agree within approximately 0.1 eV. Subsequently we investigate the qualitative transferability of bulk derived SEPs to Fe/MgO/Fe tunnel junctions. We find that the SEP method is particularly well suited to address the tight binding transferability problem because the transferability error at the interface can be characterized not only in orbital space (via the interface local density of states) but also in real …

Rarefied Gas Flow In Microtubes At Different Inlet-Outlet Pressure Ratios, Z Yang, Suresh Garimella

Birck and NCN Publications

A model is developed for rarefied gas flow in long microtubes with different inlet-outlet pressure ratios at low Mach numbers. The model accounts for significant changes in Knudsen number along the length of the tube and is therefore applicable to gas flow in long tubes encountering different flow regimes along the flow length. Predictions from the model show good agreement with experimental measurements of mass flow rate, pressure drop, and inferred streamwise pressure distribution obtained under different flow conditions and offer a better match with experiments than do those from a conventional slip flow model.

Earthquake Resistance Of Integral Abutment Bridges, Robert J. Frosch, Michael E. Kreger, Aaron M. Talbott

JTRP Technical Reports

intermediate length bridges. Integral abutment construction eliminates joints and bearings which reduce long-term maintenance costs. However, in the absence of joints and bearings, the bridge abutments and foundations must be able to accommodate lateral movements from thermal expansion and contraction of the superstructure and from seismic events. Previous research has focused on the response to thermal expansion and contraction. The current research examines the response of integral abutment bridges to seismic loading. A field investigation was conducted to examine the response of an integral abutment to lateral loading from thermal expansion and contraction. The results were used to calibrate analytical …

The I-70 Greenfield Rest Area Wetland Projects, Shih-Chieh Kao, Ting Pong Chang, Rebeka Sultana, Thomas Konopka, Rao S. Govindaraju, Barry Partridge

JTRP Technical Reports

On-site treatment of wastewater at highway rest areas poses some unique and difficult challenges because of the rural locale, high variability in wastewater flow rate and strength, and lack of knowledgeable personnel on-site. As a potential alternative, a constructed subsurface wetland system was built at the I-70 rest stop nearby Greenfield, Indiana, in 2003. This wetland system, mainly composed of three wetland cells, also includes draw-and-fill and recirculation mechanisms to increase oxygen transfer to the wastewater and improve the overall treatment performance. Special considerations for highway rest areas have been emphasized. A dynamic hydraulic model was developed to help characterize …

Practices For Seamless Transmission Of Design Data From Design Phase To Construction Equipment Operation: A Synthesis Study, Philip S. Dunston, James Monty

JTRP Technical Reports

The Indiana Department of Transportation (INDOT), in response to requests from the construction contracting community, has chosen to examine how to facilitate their contractors’ use of three-dimensional machine control (3D-MC) systems, especially GPS-based systems. INDOT recognizes that the prerequisite 3D project model, if available in its intelligent electronic form, may be leveraged by both INDOT and its project partners to automate the performance of tasks other than construction. Therefore, INDOT was compelled to initiate this study to investigate the state of technology and the experiences of other state transportation agencies (STAs) and to synthesize that information to formulate recommendations for …

Efficient Unidirectional Ridge Excitation Of Surface Plasmons, I P. Radko, S I. Bozhevolnyi, G Brucoli, L Mart´In-Moreno, F J. Garc´Ia-Vidal, A Boltasseva

Birck and NCN Publications

Using leakage-radiation microscopy, we characterize the efficiency of unidirectional surface-plasmon excitation with periodic (800 nm) arrays of 130-nm-high and 330-nm-wide gold ridges on a thin gold film illuminated with a focused (5-mu m-wide) laser beam. We demonstrate that, at the resonant wavelength of 816 nm, the excitation efficiency of > 0.4 can be obtained with >= 5 ridges by adjusting the beam position. Conducting numerical simulations, we account for the experimental results and calculate the electric-field enhancement achieved near the gold surface.

Unified Theory Of Gas Damping Of Flexible Microcantilevers At Low Ambient Pressures, Rahul Bidkar, Ryan Tung, Alina Alexeenko, Sumali Hartono, Arvind Raman

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

Predicting the gas damping of microcantilevers oscillating in different vibration modes in unbounded gas at low pressures is relevant for increasing the sensitivity of microcantilever-based sensors. While existing free-molecular theories are valid only at very high Knudsen numbers, continuum models are valid only at very low Knudsen numbers. We solve the quasisteady Boltzmann equation and compute a closed-form fit for gas damping of rectangular microcantilevers that is valid over four orders of magnitude of Knudsen numbers spanning the free-molecular, the transition, and the low pressure slip flow regimes. Experiments are performed using silicon microcantilevers under controlled pressures to validate the …

Characterization Of Electrochemically Grafted Molecular Layers On Silicon For Electronic Device Applications, Adina Scott, David B. Janes

Birck and NCN Publications

Recently, there has been considerable interest in developing organically functionalized silicon surfaces for a variety of applications including sensing and nanoelectronics. In this study, a series of as-deposited, para-substituted aryl-diazonium molecular layers covalently grafted to < 111 >-orientation silicon are characterized using a variety of surface analysis techniques. Collectively, these measurements suggest that relatively ideal molecular layers can be achieved with a variety of headgroups. Submonolayer amounts of silicon oxide are detected on all modified surfaces and the extent of silicon oxidation depends on the molecular substituent. For electronic device applications, it is necessary to apply contacts to molecular layers while maintaining …

Compact Model Of Squeeze-Film Damping Based On Rarefied Flow Simulations, Xiaohui Guo, Alina Alexeenko

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

A new compact model of squeeze-film damping is developed based on the numerical solution of the Boltzmann kinetic equation. It provides a simple expression for the damping coefficient and the quality factor valid through the slip, transitional and free-molecular regimes. In this work, we have applied statistical analysis to the current model using the chi-squared test. The damping predictions are compared with both Reynolds equation-based models and experimental data. At high Knudsen numbers, the structural damping dominates the gas squeeze-film damping. When the structural damping is subtracted from the measured total damping force, good agreement is found between the model …

Gold Nanorod-Mediated Photothermolysis Induces Apoptosis Of Macrophages Via Damage Of Mitochondria, Ling Tong, Ji-Xin Cheng

Other Nanotechnology Publications

Aims: Induction of apoptosis or necrosis in activated macrophages by gold nanorod-mediated photothermolysis is demonstrated and the mechanisms underlying the processes are investigated. Materials & methods: Gold nanorods were functionalized with cysteine-octaarginine peptides (R8-NRs). Uptake of R8-NRs by activated macrophages was monitored by two-photon luminescence imaging. The laser irradiation conditions were controlled to induce apoptosis or necrosis to R8-NR-internalized macrophages. Mitochondrial damage and reactive oxygen species overproduction during photothermolysis was investigated by confocal fluorescence microscopy and transmission-electron microscopy. Results: Activated macrophages efficiently uptake R8-NRs both in vitro and in live animals. Laser irradiation of internalized nanorods with controlled power density …

Guidelines For Indot-Mpo Coordination, Myron Matlock, Jon D. Fricker

JTRP Technical Reports

Federal legislation, such as the Safe Accountable Flexible Efficient Transportation Equity Act – A Legacy for Users (SAFETEA-LU), mandates that each state’s Department of Transportation (DOT) coordinate with the Metropolitan Planning Organizations (MPO) within the state in the development and implementation of their Long-Range Transportation Plans. However, federal legislation does not indicate how the DOT and MPOs should work together, resulting in varying collaborative strategies from case to case. Developing a set of collaborative strategies that MPOs in the state of Indiana and the DOT could use during the transportation planning process could result in faster information processing and improved …

Multi-Jurisdictional Issues Related To Congestion Management, Myron Matlock, Jon D. Fricker

JTRP Technical Reports

When a project intended to solve transportation problems such as congestion and access management involves multiple cities, counties, and/or state agencies, disputes can occur due to incompatible interests, resulting in project delays. Creating a mechanism that allows the agencies to communicate and work together during the planning stages can improve the effectiveness of the final plan for the project.

The purpose of this study was to develop and provide transportation agencies with coordination and collaborative strategies that could be used to help the various agencies work together on multiple projects. This study was based on a study of the literature …

Safety Impacts Of Design Exceptions, Nataliya V. Malyshkina, Fred L. Mannering, Jose E. Thomaz

JTRP Technical Reports

Compliance to the Indiana Department of Transportation's (INDOT) highway design criteria is considered essential to ensure the roadway safety. However, for a variety of reasons, situations arise where exceptions to standard-design criteria are requested and accepted after review. This research explores the impact that design exceptions have on the accident severity and accident frequency in Indiana. Data on accidents at 36 roadway sites with design exceptions and 71 without design exceptions are used in this research, and appropriate statistical models are estimated for the severity and frequency of these accidents. The results of the detailed statistical modeling show that presence …

Economic Development Performance Measures And Rural Economic Development In Indiana, Jennifer L. Sharkey, Jon D. Fricker

JTRP Technical Reports

An important consideration when identifying and implementing transportation investments is the prospect of economic development. Government agencies are faced with the challenging task of efficiently allocating scarce resources in order to satisfy the physical needs of the state and its communities. The Indiana Department of Transportation has the difficult task of prioritizing projects involving urban and rural transportation investments while attempting to satisfy both local and state needs. Typically, urban settings provide the greatest opportunity for economic development, due to population density, public infrastructure, and ready markets. Consequently, rural areas may get left behind, becoming more isolated and unattractive from …

Mitigating The Expansive Behavior Of Chemically Treated Soils, Sochan Jung, Maria Caterina Santagata

JTRP Technical Reports

Sulfate-induced heave, resulting from the chemical treatment of sulfate rich soils, has been known to cause significant damage to pavements and other structures particularly in the south-western United States. This research addressed the problem of sulfate-induced heave in coal mine spoils, formed as a result of shallow strip coal mining, after treatment with calcium-based stabilizers. These spoils occur in areas of Indiana in which substantial infrastructure development is taking place and will continue to occur in the next 10-15 years. Samples of coal mine spoils were obtained from different sites in Indiana. While the majority of the samples exhibited sulfate …

Needs Assessment For Local Roads And Streets 2009, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This report presents the results of a study whose objective was to use the condition of local transportation infrastructure to identify the funding level required to maintain the infrastructure and then compare this with existing funding to determine the adequacy of the current funding. The basic finding of the study is evidence that there is a severe shortage of funds to adequately maintain local transportation facilities.

How To Keep Your Head Above Water While Detecting Errors, Saurabh Bagchi, Ignacio Laguna, Fahad Arshad, David M. Grothe

Department of Electrical and Computer Engineering Technical Reports

Abstract. Today’s distributed systems need runtime error detection to catch errors arising from software bugs, hardware errors, or unexpected operating conditions. A prominent class of error detection techniques operates in a stateful manner, i.e., it keeps track of the state of the application being monitored and then matches state-based rules. Large-scale distributed applications generate a high volume of messages that can overwhelm the capacity of a stateful detection system. An existing approach to handle this is to randomly sample the messages and process the subset. However, this approach, leads to non-determinism with respect to the detection system’s view of what …

Toward Surround Gates On Vertical Single-Walled Carbon Nanotube Devices, Aaron D. Franklin, Robert A. Sayer, Timothy D. Sands, Timothy Fisher, David B. Janes

Birck and NCN Publications

The one-dimensional, cylindrical nature of single-walled carbon nanotubes (SWCNTs) suggests that the ideal gating geometry for nanotube field-effect transistors (FETs) is a surround gate (SG). Using vertical SWCNTs templated in porous anodic alumina, SGs are formed using top-down processes for the dielectric/metal depositions and definition of the channel length. Surround gates allow aggressive scaling of the channel to 25% of the length attainable with a bottom-gate geometry without incurring short-channel effects. The process demonstrated here for forming SGs on vertical SWCNTs is amenable for large-scale fabrication of multinanotube FETs.

2009 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 agency officials and employees responsible for Indiana’s local road infrastructure.

Interfacial Energy Between Carbon Nanotubes And Polymers Measured From Nanoscale Peel Tests In The Atomic Force Microscope, Mark C. Strus, Camilo I. Cano, R. Byron Pipes, Cattien V. Nguyen, Arvind Raman

Other Nanotechnology Publications

The future development of polymer composite materials with nanotubes or nanoscale fibers requires the ability to understand and improve the interfacial bonding at the nanotube-polymer matrix interface. In recent work [Strus MC, Zalamea L, Raman A, Pipes RB, Nguyen CV, Stach EA. Peeling force spectroscopy: exposing the adhesive nanomechanics of one-dimensional nanostructures. Nano Lett 2008;8(2):544–50], it has been shown that a new mode in the Atomic Force Microscope (AFM), peeling force spectroscopy, can be used to understand the adhesive mechanics of carbon nanotubes peeled from a surface. In the present work, we demonstrate how AFM peeling force spectroscopy can be …

Insights Into Few-Layer Epitaxial Graphene Growth On 4h-Sic(000(1)Over-Bar Substrates From Stm Studies, Laura B. Biedermann, Michael L. Bolen, Michael A. Capano, Dmitry Zemlyanov, R. Reifenberger

Birck and NCN Publications

Epitaxial carbon was grown by heating (000 (1) over bar) silicon carbide (SiC) to high temperatures (1450-1600 degrees C) in vacuum. A continuous graphene surface layer was formed at temperatures above 1475 degrees C. X-ray photo-electron spectroscopy (XPS) and scanning tunneling microscopy (STM) were extensively used to characterize the quality of the few-layer graphene (FLG) surface. The XPS studies were useful in confirming the graphitic composition and measuring the thickness of the FLG samples. STM studies revealed a wide variety of nanometer-scale features that include sharp carbon-rich ridges, moire superlattices, one-dimensional line defects, and grain boundaries. By imaging these features …

Toward Surround Gates On Vertical Single-Walled Carbon Nanotube Devices, Aaron D. Franklin, Robert A. Sayer, Timothy D. Sands, Timothy S. Fisher, David B. Janes

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

The one-dimensional, cylindrical nature of single-walled carbon nanotubes (SWCNTs) suggests that the ideal gating geometry for nanotube field-effect transistors (FETs) is a surround gate (SG). Using vertical SWCNTs templated in porous anodic alumina, SGs are formed using top-down processes for the dielectric/metal depositions and definition of the channel length. Surround gates allow aggressive scaling of the channel to 25% of the length attainable with a bottom-gate geometry without incurring short-channel effects. The process demonstrated here for forming SGs on vertical SWCNTs is amenable for large-scale fabrication of multinanotube FETs.

Theoretical Basis Of Parametric-Resonance-Based Atomic Force Microscopy, G Prakash, S Hu, Arvind Raman, R. Reifenberger

Birck and NCN Publications

Parametric resonance underpins the physics of swings, resonant surface waves, and particle traps. There is increasing interest in its potential applications in atomic force microscopy (AFM). In this paper, the dynamics of parametrically resonant microcantilevers for high sensitivity imaging and force spectroscopy applications is investigated theoretically. Detailed numerical parametric-resonance simulations are performed to understand how the microcantilever amplitude varies with tip-sample separation, the tip-sample interaction, and the scanning dynamics of a microcantilever probe. We find three key advantages of a parametrically resonant microcantilever for AFM applications: (a) the reduction in ringing effects near feature edges that occur for high-Q microcantilevers; …

Performance-Based Contracting For Roadway Maintenance Operations In Indiana, Bob G. Mccullouch, Kumares C. Sinha, Panagiotis Ch Anastasopoulos

JTRP Technical Reports

INDOT initiated a study to investigate Performance Based Contracting of maintenance operations. One of the main impetus for the study is that INDOT started a ten year road building program called Major Moves that will add over a 1900 lane miles to the current network. With this addition and coupled with a trend of reduction in maintenance personnel, INDOT is planning how maintenance will be performed. One viable option is the use of performance based contracting (PBC). This study has evaluated many aspects of PBC and the current INDOT maintenance program. Study specifics included:

* Investigated foreign agencies PBC programs. …

A Study Of The Discrete-Time Switched Lqr Problem, Wei Zhang, Jianghai Hu, Alessandro Abate

Department of Electrical and Computer Engineering Technical Reports

This paper studies the discrete-time switched LQR (DSLQR) problem based on a dynamic programming approach. One contribution of this paper is the analytical characterization of both the value function and the optimal hybridcontrol strategy of the DSLQR problem. Their connections to the Riccati equation and the Kalman gain of the classical LQR problem are also discussed. Several interesting properties of the value functions are derived. In particular, we show that under some mild conditions, the family of finite-horizon value functions of the DSLQR problem is homogeneous (of degree 2), uniformly bounded over the unit ball, and converges exponentially fast to …

A Ph-Tunable Hydrogel Microlens Array With Temperature-Actuated Light-Switching Capability, Zhenwen Deng, Babak Ziaie

Birck and NCN Publications

In this letter, we demonstrate a two step casting process to fabricate a bifunctional hydrogel-based microlens array, which responds to both temperature (becomes opaque above certain temperature) and pH (changes its focal length at different pH levels), and can be operated in air for an extended period of time. Each lens in the array is 1 mm in diameter and its focal length changes from 4.5 to 55 mm when the environmental pH is varied between 2.0 and 5.0. The light-switching capability is measured to be similar to 92% when temperature increases from 25 to 35 degrees C.