Engineering Commons^™

Photoionization And Electron-Impact Ionization Of Ar5+, Jing Cheng Wang, M. Lu, D. A. Esteves, M. Habibi, G. Alna’Washi, R. A. Phaneuf, A. L. D. Kilcoyne

United States Department of Energy: Publications

Absolute cross sections for photoionization and electron-impact ionization of Ar⁵⁺ have been measured using two different interacting-beams setups. The spectra consist of measurements of the yield of products due to single ionization as a function of electron or photon energy. In addition, absolute photoionization and electron-impact ionization cross sections were measured to normalize the measured Ar⁶⁺ product-ion yield spectra. In the energy range from 90 to 111 eV, both electron-impact ionization and photoionization of Ar⁵⁺ are dominated by indirect 3s subshell excitation-autoionization. In the energy range from 270 to 285 eV, resonances due to 2p …

2007 Government And Industry Pipeline R&D Forum Report

United States Department of Transportation: Publications

Eleven government and industry organizations working through a steering committee, organized, planned and executed this forum. The forum brought together over 240 representatives from State, Federal, and international government offices together with domestic and international natural gas and hazardous liquid pipeline operators, along with several research providers and technology vendors. The forum’s goals included identifying key challenges facing industry and government, sharing information on current research efforts, and identifying research that can help to meet the challenges. The organizing committee included presentations recognizing emerging technology success stories and federal government approaches to technology transfer of research during the forum.

Safe & Reliable Ethanol Transportation & Storage Technology Roadmapping Workshop Summary Results

United States Department of Transportation: Publications

Biofuels, especially ethanol, are gaining attention as partial replacements of imported fuels and to offset CO2 emissions from the burning of fossil fuels. Consequently, legislation is being proposed to mandate a significant increase in ethanol usage as a fuel over the next 20 years. The planned wide-spread usage of ethanol will require an efficient and reliable transportation and storage system that encompasses both the existing infrastructure and new construction. The fuels are currently being transported by rail, truck, and ship; however, in order to economically transport biofuels from producers to users on a large scale, safe and reliable transportation by …

Peer Review Report 2007

United States Department of Transportation: Publications

The purpose of this document is to report findings from the research peer reviews held March 27-29, 2007 for PHMSA’s Pipeline Safety Research and Development Program. The findings and recommendations in this report derive from the scoring and comments collected from the peer review panelists.

Department of Transportation (DOT) Operating Agencies (OA) are required to develop and execute a systematic process for peer review plan for all influential and highly influential information the OA plans to disseminate in the foreseeable future.

Through the Information Quality Act1, Congress directed Office of Management and Budget (OMB) to “provide policy and procedural guidance …

Rd&T Program Overview 2007

United States Department of Transportation: Publications

PHMSA Mission

PHMSA Supports DOT Goals

RD&T Overview

PHMSA RD&T Program Appropriations

Pipeline Safety RD&T

1. External Stakeholder Involvement In Developing Research Agendas

1. External Stakeholder Involvement “Elements of Implementation”

1. External Stakeholder Involvement “Indicators of Implementation”

2. Merit Review of Proposals “Elements of Implementation”

2. Merit Review of Proposals “Indicators of Implementation”

3. Independent Evaluation of Research “Elements & Indicators of Implementation”

4. Performance Measurement “Elements of Implementation"

4. Performance Measurement “Indicators of Implementation”

5. RD&T Coordination “Elements of Implementation”

5. RD&T Coordination “Indicators of Implementation”

Hazardous Materials Safety RD&T

Hazmat Elements & Possible Products

Field Demonstration Report Enhancing Direct Assessment By Inspection Through Coatings And Buried Regions Of Non-Piggable Pipelines, Emat Ultrasonics, Inc.

United States Department of Transportation: Publications

Sonic Sensors of EMAT Ultrasonics Inc, with support from Pacific Gas and Electric as well as Southern California Gas has an R&D Contract with the DOT, PHMSA, OPS No. DTPH56-06-T-0009. The goal of this contract was to develop a method to inspect the full body of a pipe without having to remove the coating or completely excavate the pipe as shown in Figure 1. External Corrosion Direct Assessment, ECDA, depends on exploratory digging to evaluate the condition of suspect coatings detected by cathodic protection CIS. Minimizing the extent of excavation required to perform an ECDA evaluation has obvious cost savings …

Identification Of Chicken-Specific Fecal Microbial Sequences Using A Metagenomic Approach, Jingrang Lu, Jorge Santo Domingo, Orin Shanks

United States Environmental Protection Agency: Publications

In this study, we applied a genome fragment enrichment (GFE) method to select for genomic regions that differ among different fecal metagenomes. Competitive DNA hybridizations were performed between chicken fecal DNA and pig fecal DNA (CP) and between chicken fecal DNA and an avian DNA composite consisting of turkey, goose, and seagull fecal DNA extracts (CB) to enrich for chicken-specific DNA fragments. A total of 471 non-redundant chicken metagenomic sequences were retrieved and analyzed. All of the clone sequences were similar to prokaryotic genes, of which more than 60% could not be assigned to previously characterized functional roles. In general …

Florida Seagrass Habitat Evaluation: A Comparative Survey For Chemical Quality, Michael A. Lewis, Darrin D. Dantin, Cynthia A. Chancy, Kathryn Abel, Christopher G. Lewis

United States Environmental Protection Agency: Publications

Contaminant concentrations were determined for media associated with 13 Florida seagrass beds. Concentrations of 10 trace metals were more commonly detected in surface water, sediment and two seagrass species than PAHs, pesticides and PCBs. Concentrations of copper and arsenic in surface water exceeded Florida aquatic life criteria more frequently than other trace elements. Total organic carbon, mercury, chromium, zinc, total chlordane, total PAHs, total PCBs, DDD and DDE were significantly greater in seagrass-rooted sediments than adjacent non-vegetated sediments. Total DDT, DDD, DDE, total chlordane, arsenic, copper and nickel exceeded proposed sediment quality guidelines at six of 13 grass beds. Pesticides, …

Convergence Of Peridynamics To Classical Elasticity Theory, S. A. Silling, R. B. Lehoucq

United States Department of Energy: Publications

The peridynamic model of solid mechanics is a nonlocal theory containing a length scale. It is based on direct interactions between points in a continuum separated from each other by a finite distance. The maximum interaction distance provides a length scale for the material model. This paper addresses the question of whether the peridynamic model for an elastic material reproduces the classical local model as this length scale goes to zero. We show that if the motion, constitutive model, and any nonhomogeneities are sufficiently smooth, then the peridynamic stress tensor converges in this limit to a Piola-Kirchhoff stress tensor that …

Uranium(Vi) Release From Contaminated Vadose Zone Sediments: Estimation Of Potential Contributions From Dissolution And Desorption, Deborah L. Bond, James A. Davis, John M. Zachara

United States Department of Energy: Publications

A key difficulty in developing accurate, science-based conceptual models for remediation of contaminated field sites is the proper accounting of multiple coupled geochemical and hydrologic processes. An example of such a difficulty is the separation of desorption and dissolution processes in releasing contaminants from sediments to groundwaters; very few studies are found in the literature that attempt to quantify contaminant release by these two processes. In this study, the results from several extraction techniques, isotopic exchange experiments, and published spectroscopic studies were combined to estimate the contributions of desorption and dissolution to U(VI) release from contaminated sediments collected from the …

Kinetics Of Reductive Dissolution Of Hematite By Bioreduced Anthraquinone-2,6-Disulfonate, Chongxuan Liu, John M. Zachara, Nancy Foster, Janae Strickland

United States Department of Energy: Publications

The reductive dissolution of hematite (α-Fe₂O₃) was investigated in a flow-through system using AH2DS, a reduced form of anthraquinone-2,6-disulfonate (AQDS), which is often used as a model electron shuttling compound in studies of dissimilatory microbial reduction of iron oxides. Influent flow rate, pH, and Fe(II) and phosphate concentrations were varied to investigate the redox kinetics in a flow-through reactor. The hematite reduction rates decreased with increasing pH from 4.5 to 7.6 and decreased with decreasing flow rate. The rates also decreased with increasing influent concentration of Fe(II) or phosphate that formed surface complexes at the experimental …

Respiration Of Metal (Hydr)Oxides By Shewanella And Geobacter: A Key Role For Multihaem C-Type Cytochromes, Liang Shi, Thomas C. Squier, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal …

Diversifying Biological Fuel Cell Designs By Use Of Nanoporous Filters, Justin C. Biffinger, Ricky Ray, Brenda Little, Bradley R. Ringeisen

United States Navy: Publications

The use of proton exchange membranes (PEMs) in biological fuel cells limits the diversity of novel designs for increasing output power or enabling autonomous function in unique environments. Here we show that selected nanoporous polymer filters (nylon, cellulose, or polycarbonate) can be used effectively in place of PEMs in a miniature microbial fuel cell (mini-MFC, device cross-section 2 cm²), generating a power density of 16 W/m³ with an uncoated graphite felt oxygen reduction reaction (ORR) cathode. The incorporation of polycarbonate or nylon membranes into biological fuel cell designs produced comparable power and durability to Nafion-117 membranes. Also, …

U.S. Army Corps Of Engineers Omaha District Monthly Drought Report, January 2007

United States Army Corps of Engineers, Omaha District

Current Conditions

Drought Outlook

Missouri River Region Mountain Snowpack Report

Ft. Peck, Montana

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Garrison, North Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Boat Ramp Information

Noxious Weeds Overview

Cultural Resources Overview

Other Areas of Interest/Concern

Oahe, South Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Mainstem Reservoir Information, Weekly Elevation Comparison 6 NOV 2006 through 27 NOV 2006

Mainstem Reservoir Storage Comparison Water Years 2004, 2005, 2006

Ft. Peck, MT

Garrison, ND

Oahe, SD

U.S. Army Corps Of Engineers Omaha District Monthly Drought Report, May 2007

United States Army Corps of Engineers, Omaha District

Current Conditions

Drought Outlook

Missouri River Region Mountain Snowpack Report

Ft. Peck, Montana

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Garrison, North Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Boat Ramp Information

Noxious Weeds Overview

Cultural Resources Overview

Other Areas of Interest/Concern

Oahe, South Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Mainstem Reservoir Information, Weekly Elevation Comparison 5 MAR 2007 through 26 MAR 2007

Mainstem Reservoir Storage Comparison Water Years 2004, 2005, 2006

Ft. Peck, MT

Garrison, ND

Oahe, SD

Genetically Attenuated Plasmodium Berghei Liver Stages Induce Sterile Protracted Protection That Is Mediated By Major Histocompatibility Complex Class I–Dependent Interferon-Y–Producing Cd8+ T Cells, Ousman Jobe, Joanne Lumsden, Ann-Kristin Mueller, Jackie Williams, Hilda Silva-Rivera, Stefan H. I. Kappe, Robert J. Schwenk, Kai Matuschewski, Urszula Krzych

United States Army: Publications

At present, radiation-attenuated plasmodia sporozoites (y-spz) is the only vaccine that induces sterile and lasting protection in malaria-naive humans and laboratory rodents. However, g-spz are not without risks. For example, the heterogeneity of the y-spz could explain occasional breakthrough infections. To avoid this possibility, we constructed a double-knockout P. berghei parasite by removing 2 genes, UIS3 and UIS4, that are up-regulated in infective spz.We evaluated the double-knockout Pbuis3(-)/4(-) parasites for protective efficacy and the contribution of CD8+ T cells to protection. Pbuis3(-)/4(-) spz induced sterile and protracted protection in C57BL/6 mice. Protection was linked to CD8+ …

A New Mass Sensor Based On Thickness-Twist Edge Modes In A Piezoelectric Plate, J.S. Yang, A. K. Soh

Department of Engineering Mechanics: Faculty Publications

We propose a new mass sensor based on thickness-twist edge modes in a piezoelectric plate of 6mm crystals. By performing a theoretical analysis, a simple expression of sensitivity is obtained. The proposed sensor has an important advantage in the sense that it can be mounted away from the edge of the plate where the motion is insignificant and, thus, the operation of the device is unaffected.

Effect Of Interface Modification On The Mechanical Behavior Of Carbon Nanotube Reinforced Composites Using Parallelmolecular Dynamics Simulations, S. Namilae, U. Chandra, A. Srinivasan, Namas Chandra

Department of Engineering Mechanics: Faculty Publications

Molecular dynamics (MD) simulations play an important predictive role in understanding the behavior of nanoscale systems. In this paper, parallel MD simulations are used to understand the mechanical behavior of interfaces in CNT based composites. We present an algorithm for parallel implementation of MD simulations of carbon nanotube (CNT) based systems using reactive bond order potentials. We then use that algorithm to model the CNT-polymer interfaces with various levels of interaction as (a) described only by long range Van Der Waals interactions (b) chemically bonded with fixed matrix and (c) chemically bonded with matrix explicitly modeled. It is shown that …

Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.

Department of Engineering Mechanics: Faculty Publications

The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …

Using Adaptive Management To Meet Conservation Goals, Thomas M. Franklin Franklin, Ronald Helinski Helinski, Andrew Manale Manale

United States Environmental Protection Agency: Publications

Natural resource professionals should know whether or not they are doing an effective job of managing natural resources. Their decision-making process should produce the kind of results desired by the public, elected officials, and their agencies’ leadership. With billions of dollars spent each year on managing natural resources, accountability is more important than ever. Producing results is the key to success. Managers must have the necessary data to make enlightened decisions during program implementation—not just at the conclusion of a program. Adaptive management is described as an adapt-and-learn methodology as it pertains to implementing Farm Bill conservation practices. Four regional …

Mlds: A Flexible Location Directory Service For Tiered Sensor Networks, Sangeeta Bhattacharya, Chien-Liang Fok, Chenyang Lu, Gruia-Catalin Roman

All Computer Science and Engineering Research

Many emergent distributed sensing applications need to keep track of mobile entities across multiple sensor networks connected via an IP network. To simplify the realization of such applications, we present MLDS, a Multi-resolution Location Directory Service for tiered sensor networks. MLDS provides a rich set of spatial query services ranging from simple queries about entity location, to complex nearest neighbor queries. Furthermore, MLDS supports multiple query granularities which allow an application to achieve the desired tradeoff between query accuracy and communication cost. We implemented MLDS on Agimone, a unified middleware for sensor and IP networks. We then deployed and evaluated …

Real-Time Query Scheduling For Wireless Sensor Networks, Octav Chipara, Chenyang Lu, Gruia-Catalin Roman

All Computer Science and Engineering Research

Recent years have seen the emergence of wireless sensor network (WSN) systems that require high data rate real-time communication. This paper proposes Real-Time Query Scheduling (RTQS), a novel approach to conflict-free transmission scheduling for real-time queries in WSNs. We show that there is an inherent trade-off between prioritization and throughput in conflict-free query scheduling. RTQS provides three new real-time scheduling algorithms. The non-preemptive query scheduling algorithm achieves high throughput while introducing priority inversions. The preemptive query scheduling algorithm eliminates priority inversion at the cost of reduced throughput. The slack stealing query scheduling algorithm combines the benefits of preemptive and non-preemptive …

A Duality Theory With Zero Duality Gap For Nonlinear Programming, Yixin Chen

All Computer Science and Engineering Research

Duality is an important notion for constrained optimization which provides a theoretical foundation for a number of constraint decomposition schemes such as separable programming and for deriving lower bounds in space decomposition algorithms such as branch and bound. However, the conventional duality theory has the fundamental limit that it leads to duality gaps for nonconvex optimization problems, especially discrete and mixed-integer problems where the feasible sets are nonconvex. In this paper, we propose a novel extended duality theory for nonlinear optimization that overcomes some limitations of previous dual methods. Based on a new dual function, the extended duality theory leads …

Hexa: Compact Data Structures For Faster Packet Processing, Sailesh Kumar, Jonathan Turner, Patrick Crowley, Michael Mitzenmacher

All Computer Science and Engineering Research

Directed graphs with edge labels are used in packet processing algorithms for a variety of network applications. In this paper we present a novel representation for such graph that significantly reduces the memory required for such graphs. This approach called History-based Encoding, eXecution and Addressing (HEXA) challenges the conventional assumption that graph data structures must store pointers of log2n bits to identify successor nodes. HEXA takes advantage of implict information to reduce the information that must be stored explicitly. We demonstrate that the binary tries used for IP route lookup can be implemented using just two bytes per stored prefix …

Architecture For Document Clustering In Reconfigurable Hardware, Master's Thesis, December 2006, Adam G. Covington

All Computer Science and Engineering Research

High-performance document clustering systems enable similar documents to automatically self-organize into groups. In the past, the large amount of computational time needed to cluster documents prevented practical use of such systems with a large number of documents. A full hardware implementation of K-means clustering has been designed and implemented in reconfigurable hardware that rapidly clusters a half million documents. Documents and concepts are represented as vectors with 4000 dimensions. The circuit was implemented in Field Programmable Gate Array (FPGA) logic and uses four parallel cosine distance metrics to cluster document vectors together. An exploration of the effect of the integer …

Single Cell Expression Profiling Reveals Major Disruption Of Dna Repair Capacity In Incipient Alzheimer's Disease, Monika Ray, Weixiong Zhang

All Computer Science and Engineering Research

Understanding the pathogenesis in the early stages of late-onset Alzheimer's disease (LOAD) can help in gaining important mechanistic insights into this devastating neurodegenerative disorder. Alzheimer's disease (AD) is characterised by extensive cell death with disease progression. In this paper laser capture microdissection (LCM) based gene expression profiling, which is able to profile gene expression in a single cell type, is employed to analyse the gene expression regulation of incipient AD. Our analysis shows that LCM based gene expression profiling of neurons has a critical advantage over the conventional gene expression profiling method which uses samples of mixed cell types and …

Price Of Asynchrony: Queuing Under Ideally Smooth Congestion Control, Maxim Podlesny, Sergey Gorinsky

All Computer Science and Engineering Research

The ability of TCP (Transmission Control Protocol) or alternative congestion control algorithms to operate successfully in networks with small link buffers has recently become a subject of intensive research. In this paper, we investigate fundamental limitations on minimum buffer requirements for any congestion control. We present an idealized protocol where all flows always transmit at their fair rates. The ideally smooth congestion control causes link queuing only due to asynchrony of flow arrivals, which is intrinsic to computer networks. Our analysis and simulations for different distributions of flow interarrival times agree that the buffer size needed for a fixed loss …

Distributed Allocation Of Workflow Tasks In Manets, Rohan Sen, Gruia-Catalin Roman, Christopher Gill

All Computer Science and Engineering Research

When multiple participants work on a workflow that represents a large, collaborative activity, it is important to have a well defined process to determine the portions of the workflow that each participant is responsible for executing. In this paper, we describe a process and related algorithms required to assign tasks in a workflow, to hosts that are willing to carry out the execution of these tasks, and thereby contributing to the completion of the activity. This problem is a stylized form of the multi-processor scheduling algorithm which has been shown to be NP-Hard. Further complicating the issue is that we …

Implementing Legba: Fine-Grained Memory Protection, Sheffield, Sowell, Wilson

All Computer Science and Engineering Research

Fine-grained hardware protection could provide a powerful and effective means for isolating untrusted code. However, previous techniques for providing fine-grained protection in hardware have lead to poor performance. Legba has been proposed as a new caching architecture, designed to reduce the granularity of protection, without slowing down the processor. Unfortunately, the designers of Legba have not attempted an implementation. Instead, all of their analysis is based purely on simulations. We present an implementation of the Legba design on a MIPS Core Processor, along with an analysis of our observations and results.

Customizing Component Middleware For Distributed Real-Time Systems With Aperiodic And Periodic Tasks, Yuanfang Zhang, Christopher Gill, Chenyang Lu

All Computer Science and Engineering Research

Many distributed real-time applications must handle mixed aperiodic and periodic tasks with diverse requirements. However, existing middleware lacks flexible configuration mechanisms needed to manage end-to-end timing easily for a wide range of different applications with both aperiodic and periodic tasks. The primary contribution of this work is the design, implementation and performance evaluation of the first configurable component middleware services for admission control and load balancing of aperiodic and periodic tasks in distributed real-time systems. Empirical results demonstrate the need for, and the effectiveness of, our configurable component middleware approach in supporting different applications with aperiodic and periodic tasks.