Engineering Commons^™

Simulation Of Phonon-Assisted Band-To Band Tunneling In Carbon Nanotube Field-Effect Transistors, Siyuranga O. Koswatta, Mark S. Lundstrom, M. P. Anantram, Dmitri E. Nikonov

Other Nanotechnology Publications

Electronic transport in a carbon nanotube metal-oxide-semiconductor field effect transistor (MOSFET) is simulated using the nonequilibrium Green’s functions method with the account of electron-phonon scattering. For MOSFETs, ambipolar conduction is explained via phonon-assisted band-to-band (Landau–Zener) tunneling. In comparison to the ballistic case, we show that the phonon scattering shifts the onset of ambipolar conduction to more positive gate voltage (thereby increasing the off current). It is found that the subthreshold swing in ambipolar conduction can be made as steep as 40 mV/decade despite the effect of phonon scattering.

Guidelines For Traffic Counts On Local Roads And Streets, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The purpose of this document is to provide a series of guidelines to assist in the creation of a system that will enable the collection of complete and accurate traffic data.

Included within these guidelines is a list of all appropriate counting devices. There have been several listed so that a wide range of needs and budgets could be satisfied. Also included is a guide for planning a traffic count program and data collection session. Once the data is collected, it then becomes necessary to evaluate and analyze the data so that accurate traffic volume predictions can be made. This …

In Vitro And In Vivo Two-Photon Luminescence Imaging Of Single Gold Nanorods, Haifeng Weng, Terry B. Huff, Daniel A. Zweifel, Wei He, Philip S. Low, Alexander Wei, Ji-Xin Cheng

Other Nanotechnology Publications

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a cos(4) dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels.

2005 Indiana County Highway Departments Bridge Replacement Cost Estimation Procedures, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This report is intended to provide county bridge officials a simple, straight forward method to estimate the costs of replacing county bridges. The report uses information from bridges constructed from 1997 through 2005, which was obtained through surveys completed by Indiana counties. Regressions were performed on the data and a spreadsheet prepared that allows users to input Average Daily Traffic (ADT) and the old bridge length to obtain an estimate for the cost of a replacement bridge.

Optimal Control Theory Applied To A Difference Equation Model Of Cardiopulmonary Resuscitation, Eunok Jung, Charles F. Babbs, Suzanne Lenhart, Vladimir A. Protopoescu

Weldon School of Biomedical Engineering Faculty Publications

Objective: To apply the mathematical techniques of optimal control theory (OCT) to a validated model of the human circulation during cardiopulmonary resuscitation (CPR), so as to discover improved waveforms for chest compression and decompression that maximize the systemic perfusion pressure (SPP). Methods: The human circulatory system is represented by seven difference equations, which describe the pressure changes in systemic vascular compartments caused by chest compression. The forcing term is the intrathoracic pressure generated by the external chest compression, which is taken as the “control” variable for the system. The optimum waveform of this forcing pressure as a function of time, …

2005 Indiana County Highway Department Wage And Salary Survey, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

Included in this publication are wage and salary figures for the major salaried and hourly county highway positions in Indiana. In addition, the numbers of employees working under each job title are tabulated, and the ratio of total number of employees per mile of county road is displayed. The following series of tables are divided into four categories: administration, maintenance and repair, general and undistributed, and cumulative bridge. The appendix presents the recommended methods for calculating the labor burden for both salaried and hourly employees. Also included are generalized worksheets, which may be copied and used to calculate labor burden …

2005 Summary Of Highway Revenues, Distributions, & Expenses For Indiana Counties, Cities, & Towns, Ken Smith

Indiana Local Technical Assistance Program (LTAP) Publications

This report provides information on revenues, distributions, and expenses of state and local governments for highway, road, and street work. Since the Motor Vehicle Highway (MVH) and Local Road and Street (LRS) Accounts are the principal source of funds for local road or street construction and maintenance operations, this summary may be used to see the trends in income sources and in the expenses charged to the funds prior to their being distributed to the highway, road, and street agencies.

A Dose-Response Curve For The Negative Bias Pressure Of An Intrathoracic Pressure Regulator During Cpr, Charles F. Babbs, Demetris Yannopoulos

Weldon School of Biomedical Engineering Faculty Publications

An intrathoracic pressure regulator (ITPR) is a device that can be added to the external end of an endotracheal tube to create controlled negative airway pressure between positive pressure ventilations. The resulting downward bias of the airway pressure baseline promotes increased venous return and enhanced circulation during CPR and also during hypovolemic shock. In the present study we exercised a mathematical model of the human cardiopulmonary system, including airways, lungs, a 4 chambered heart, great vessels, peripheral vascular beds, and the biomechanics of chest compression and recoil, to determine the relationship between systemic perfusion pressure during CPR and the value …

Intravenous Polyethylene Glycol Inhibits The Loss Of Cerebral Cells After Brain Injury, Andrew O. Koob, Bradley S. Duerstock, Charles F. Babbs, Yinlong Sun, Richard B. Borgens

Weldon School of Biomedical Engineering Faculty Publications

We have tested the effectiveness of polyethylene glycol (PEG) to restore the integrity of neuronal membranes after mechanical damage secondary to severe traumatic brain injury (TBI) produced by a standardized head injury model in rats. We provide additional detail on the standardization of this model, particularly the use and storage of foam bedding that serves to both support the animal during the impact procedure and to dampen the acceleration of the brass weight. Further, we employed a dye exclusion technique using ethidium bromide (EB; quantitative evaluation) and horseradish peroxidase (HRP; qualitative evaluation). Both have been successfully used previously to evaluate …

Biophysics Of Cardiopulmonary Resuscitation With Periodic Z-Axis Acceleration Of Abdominal Compression At Aortic Resonant Frequencies, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Periodic z-axis acceleration (pGz)-CPR involves oscillating motion of a whole patient in the head-to-foot dimension on a mechanized table. The method is able to sustain blood flow and long-term survival during and after prolonged cardiac arrest in anesthetized pigs. However, the exact mechanism by which circulation of blood is created has remained unknown. Objectives: To explain the hemodynamic mechanism of pGz-CPR and to suggest theoretically useful improvements. Method: Computer modeling using a hybrid analytical-numerical approach, based upon Newton’s second law of motion for fluid columns in the aorta and vena cavae, Ohm’s law for resistive flow through vascular beds, and …

Stabilization And Improvement Of Organic Soils, Joonho Hwang, Aaron Humphrey, Antonio Bobet, Maria Caterina Santagata

JTRP Technical Reports

Peats and organic soils in general pose significant problems to geotechnical engineers due to their low strength, high compressibility and elevated creep. The research performed addressed one soil improving technique, deep soil mixing, that has been widely used for treating soft clays, but that especially in the US has found limited use in presence of organic soils. The work performed made use primarily of one soil sampled on Lindberg Road (LR) in West Lafayette, IN characterized by LOI= 45-52%, LL= 327%, PL= 162%, LLoven dried/LLnon-dried = 0.31, Gs = 2.05-2.12, fiber content ~2.29%, clay fraction = 40.6%. In addition, a …

Distance Estimation Algorithm For Stereo Pair Images, Edwin Tjandranegara

Department of Electrical and Computer Engineering Technical Reports

Various algorithms have been proposed for estimating camera distance from objects in digital stereo pair videos and images. Existing algorithms assume that digital images were taken with pan and tilt cameras or assume that the angles between the cameras and the object are known. The algorithm that we are proposing has the ability to calculate distance from the camera plane to the object plane, where the cameras do not have the ability to pan and tilt nor the angles between the cameras and the object are known beforehand.

Modern Technologies For Design Data Collection, James Samuel Bethel, Steven D. Johnson, Monica Prezzi, Boudewijn H. W. Van Gelder, Bob G. Mccullouch, Ali Fuat Cetin, Seungwoo Han, Mosab Hawarey, Changno Lee, Aparajithan Sampath, Jie Shan

JTRP Technical Reports

Design data collection involving the use of Lidar instrument, in conjunction with GPS proves to be very effective. Data required to model two bridges over the I-70 was collected on a single day, involving five and six sessions with Lidar equipment. Even though the data was collected on two bridges, it did not cause any disruption of the traffic, either on the Interstate or on the bridges. A major cause of concern during survey activities, particularly along interstates is safety, both for the motorists as well as the people involved in data collection. Lidar data collection was found to be …

Theoretical Investigation Of Surface Roughness Scattering In Silicon Nanowire Transistors, Jing Wang, Eric Polizzi, Avik Ghosh, Supriyo Datta, Mark Lundstrom

Other Nanotechnology Publications

Using a full three-dimensional (3D), quantum transport simulator, we theoretically investigate the effects of surface roughness scattering (SRS) on the device characteristics of Si nanowire transistors (SNWTs). The microscopic structure of the Si/SiO2 interface roughness is directly treated by using a 3D finite element technique. The results show that (1) SRS reduces the electron density of states in the channel, which increases the SNWT threshold voltage, and (2) the SRS in SNWTs becomes less effective when fewer propagating modes are occupied, which implies that SRS is less important in small-diameter SNWTs with few modes conducting than in planar metal-oxide-semiconductor field-effect-transistors …

A Novel Hybrid Heat Sink Using Phase Change Materials For Transient Thermal Management Of Electronics, Shankar Krishnan, S V. Garimella, S. S. Kang

CTRC Research Publications

A hybrid heat sink concept which combines passive and active cooling approaches is proposed. The hybrid heat sink is essentially a plate fin heat sink with the tip immersed in a phase change material (PCM). The exposed area of the fins dissipates heat during periods when high convective cooling is available. When the air cooling is reduced, the heat is absorbed by the PCM. The governing conservation equations are solved using a finite-volume method on orthogonal, rectangular grids. An enthalpy method is used for modeling the melting/re-solidification phenomena. Results from the analysis elucidate the thermal performance of these hybrid heat …

Role Of Phonon Scattering In Carbon Nanotube Field-Effect Transistors, Jing Guo, Mark Lundstrom

Other Nanotechnology Publications

The role of phonon scattering in carbon nanotube field-effect transistors 􏰏CNTFETs􏰀 is explored by solving the Boltzmann transport equation using the Monte Carlo method. The results show that elastic scattering in a short-channel CNTFET has a small effect on the source-drain current due to the long elastic mean-free path (mfp)(~ 1µm). If elastic scattering with a short mfp were to exist in a CNTFET, the on current would be severely degraded due to the one-dimensional channel geometry. At high drain bias, optical phonon scattering, which has a much shorter mfp (-10 nm), is expected to dominate, even in a short-channel …

2004 Statewide Wheel Tax Rates, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This publication is a compilation of wheel tax rates using data provided by the Indiana Bureau of Motor Vehicles.

2005 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.

Effects Of An Impedance Threshold Valve Upon Hemodynamics In Standard Cpr: Studies In A Refined Computational Model, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

An impedance threshold valve (ITV) is a new airway adjunct for resuscitation that permits generation of a small vacuum in the chest during the recoil phase of chest compression. Objectives: To explore in detail the expected magnitude and the hemodynamic mechanisms of circulatory augmentation by an ITV in standard CPR. Method: A 14-compartment mathematical model of the human cardiopulmonary system—upgraded to include applied chest compression force, elastic recoil of the chest wall, anatomic details of the heart and lungs, and the biomechanics of mediastinal compression—is exercised to explore the conditions required for circulatory augmentation by an ITV during various modes …

Analysis And Modeling Of Information Flow And Distributed Expertise In Space-Related Operations, Barrett S. Caldwell

School of Industrial Engineering Faculty Publications

Evolving space operations requirements and mission planning for long-duration expeditions require detailed examinationsand evaluations of information flow dynamics, knowledge-sharing processes, and information technology use in distributedexpert networks. This paper describes the work conducted with flight controllers in the Mission Control Center (MCC) ofNASA’s Johnson Space Center. This MCC work describes the behavior of experts in a distributed supervisory coordinationframework, which extends supervisory control/command and control models of human task performance. Findings from thiswork are helping to develop analysis techniques, information architectures, and system simulation capabilities for knowledgesharing in an expert community. These findings are being applied to improve knowledge-sharing processes …

International Partnership Using Remotely Accessed Labs, William J. Hutzel, Rudolf Furter

School of Engineering Technology Faculty Publications

An international project between the Mechanical Engineering Technology Department at Purdue University and the HVAC Engineering Department at HTA Lucerne (Switzerland) is testing the limits of the remote access concept by creating a laboratory network that is separated by thousands of miles. Using web-enabled HVAC equipment, U.S. students are determining the performance and return on investment for a heat recovery system that is physically located in Switzerland. The converse is also true, Swiss students have access to a variety of equipment located in the U.S. This remote access project is a good example of a sustainable partnership that adds an …

Shaping The Self Efficacy Beliefs Of First Year Engineering Students: What Is The Role We Play?, Mica A Hutchison, George Bodner, Deborah Follman

School of Engineering Education Graduate Student Series

No abstract provided.

On The Role Of Phonon Scattering In Carbon Nanotube Field-Effect Transistors, Jing Guo, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The role of phonon scattering in carbon nanotube field-effect transistors (CNTFETs) is explored by solving the Boltzmann transport equation using the Monte Carlo method. The results show that elastic scattering in a short-channel CNTFET has a small effect on the source-drain current due to the long elastic mean-free path (mfp) (~1μm)(~1μm). If elastic scattering with a short mfp were to exist in a CNTFET, the on current would be severely degraded due to the one-dimensional channel geometry. At high drain bias, optical phonon scattering, which has a much shorter mfp (~10nm)(~10nm), is expected to dominate, even in a short-channel CNTFET. …

Simulation Of Phonon-Assisted Band-To-Band Tunneling In Carbon Nanotube Field-Effect Transistors, Siyuranga O. Koswatta, Mark S. Lundstrom, M. P. Anantram, Dmitri E. Nikonov

Department of Electrical and Computer Engineering Faculty Publications

Electronic transport in a carbon nanotube metal-oxide-semiconductor field effect transistor MOSFET is simulated using the nonequilibrium Green’s functions method with the account of electron-phonon scattering. For MOSFETs, ambipolar conduction is explained via phonon-assisted band-to-band Landau-Zener tunneling. In comparison to the ballistic case, we show that the phonon scattering shifts the onset of ambipolar conduction to more positive gate voltage thereby increasing the off current. It is found that the subthreshold swing in ambipolar conduction can be made as steep as 40 mV/decade despite the effect of phonon scattering

A Theoretical Investigation Of Surface Roughness Scattering In Silicon Nanowire Transistors, Jing Wang, Eric Polizzi, Avik Ghosh, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The role of phonon scattering in carbon nanotube field-effect transistors sCNTFETsd is explored by solving the Boltzmann transport equation using the Monte Carlo method. The results show that elastic scattering in a short-channel CNTFET has a small effect on the source-drain current due to the long elastic mean-free path smfpd s,1 mmd. If elastic scattering with a short mfp were to exist in a CNTFET, the on current would be severely degraded due to the one-dimensional channel geometry. At high drain bias, optical phonon scattering, which has a much shorter mfp s,10 nmd, is expected to dominate, even in a …

Guideline Specifications For Construction And Maintenance Equipment For Street And Highway Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This document is intended to help the purchasing agent of a local public agency to prepare, issue, revise, maintain and monitor use of specifications. It will also serve as a guide to the purchasing agency in maintaining an indexed file of specifications prepared by or under the authority of its purchasing agents. More importantly, however, it is hoped that this document will be a useful tool for county engineers and supervisors and city and town street commissioners in purchasing their equipment. Good equipment specifications are necessary to ensure that the owner gets the piece of equipment that they need, and …

Relative Effectiveness Of Interposed Abdominal Compression Cpr: Sensitivity Analysis And Recommended Compression Rates, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Interposed abdominal compression (IAC)-CPR incorporates alternating chest and abdominal compressions to generate enhanced artificial circulation during cardiac arrest. The technique has been generally successful in improving blood flow and survival compared to standard CPR; however some questions remain. Objective: To determine "why does IAC-CPR produce more apparent benefit in some subjects than in others? and "what is the proper compression rate, given that there are actually two compressions (chest and abdomen) in each cycle?" Method: Computer models provide a means to search for subtle effects in complex systems. The present study employs a validated 12-compartment mathematical model of the human …

Remediation And Stabilization Of Soils Contaminated By Lead Resulting From The Removal Of Paint From Bridges, M. K. Banks, A. Paul Schwab

JTRP Technical Reports

Lead-based paints are commonly used for painting steel bridge structures. Soils in the immediate vicinity of older bridges have been contaminated with Pb as a result of normal weathering and peeling of the paint coupled with removal prior to repainting. The objectives of this project were to assess the extent of lead contamination near highway bridges and to evaluate phytoremediation and immobilization as means of remediation. We examined soils in the vicinity of approximately 20 bridges in Indiana that had been repainted recently and were know to have been painted originally with Pb-based paint. We found only three bridges in …

Family Of Compaction Curves For Chemically Modified Soils, Radha Krishna Daita, Vincent P. Drnevich, Daehyeon Kim

JTRP Technical Reports

Lime and Lime Kiln Dust (LKD) are widely used for modifying/stabilizing pavement subgrades. The addition of lime or LKD involves chemical processes that are dependent on many parameters. For natural subgrades, quality control is based on moisture and unit weight requirements using manual interpolations of one-point test data on a family of curves. For modified soils, moisture and unit weight measurements are insufficient for quality control and other tests must be considered. Various possible quality control methods for LKD-modified subgrades were evaluated. This research produced an Excel-based program to automate the generation of a family of curves and one-point data …

Shear Reinforcement Requirements For High-Strength Concrete Bridge Girders, J. A. Ramirez, Gerardo Aguilar

JTRP Technical Reports

A research program was conducted on the shear strength of high-strength concrete members. The objective was to evaluate the shear behavior and strength of concrete bridge members with compressive strengths in the range of 10 000 to 15 000 psi. The goal was to determine if the current minimum amount of shear reinforcement together with maximum spacing limits in the 2004 AASHTO LRFD Specifications, and the upper limit on the nominal shear strength were applicable to concrete compressive strengths up to 15 000 psi.

A total of twenty I-shaped specimens were tested monotonically to failure. Sixteen specimens were reinforced concrete …