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2009

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Articles 4621 - 4650 of 7615

Full-Text Articles in Physical Sciences and Mathematics

Characterizing Lessons Learned From Federal Biomass Removal Projects, Dennia R. Becker, Dalia Abbas, Kathleen E. Halvorsen, Pamela J. Jakes, Sarah M. Mccaffrey, Cassandra Moseley Jan 2009

Characterizing Lessons Learned From Federal Biomass Removal Projects, Dennia R. Becker, Dalia Abbas, Kathleen E. Halvorsen, Pamela J. Jakes, Sarah M. Mccaffrey, Cassandra Moseley

JFSP Research Project Reports

The idea of offsetting the costs of wildfire hazardous fuels reduction treatments by selling the biomass removed is appealing. There are however challenges to biomass utilization that impedes progress. For instance, the lack of biomass processing capacity may impede progress in some regions, while in other regions an inconsistent supply of biomass available for wood products markets limits private investment. Despite efforts to increase biomass utilization, uncertainty exists of regarding the characteristics necessary to stimulate biomass utilization, effectiveness of agency and local efforts, and the role of partnerships in building the types of capacity necessary to expedite biomass removal. The …


Creating Stand-Level Prescriptions That Integrate Ecological And Fuel Management Objectives Across The Eastern Cascades – A Workshop, John F. Lehmkuhl, Sue Livingston, Karl Halupka, Eric Knapp, John Bailey, Bill Gaines Jan 2009

Creating Stand-Level Prescriptions That Integrate Ecological And Fuel Management Objectives Across The Eastern Cascades – A Workshop, John F. Lehmkuhl, Sue Livingston, Karl Halupka, Eric Knapp, John Bailey, Bill Gaines

JFSP Research Project Reports

The primary goal of this workshop was to develop a range of fuel reduction prescriptions that integrate fuel and ecological objectives specifically related to northern spotted owl (NSO) conservation in dry forests of the Cascade Range in eastern Washington and Oregon and northern California. The workshop was held at the Eagle Crest Resort, Redmond, Oregon, from October 13-15, 2009. Over 200 managers and scientists attended from California, Oregon, and Washington. Most (82%) of the 194 people who formally registered for the workshop worked for federal land management, research, or regulatory agencies. The rest were a mix of university faculty and …


Development And Delivery Of Version 2 Of The Fire And Fuels Extension To The Forest Vegetation Simulator, Nicholas Crookston, Stephanie Rebain, Elizabeth Reinhardt, Gary Dixon Jan 2009

Development And Delivery Of Version 2 Of The Fire And Fuels Extension To The Forest Vegetation Simulator, Nicholas Crookston, Stephanie Rebain, Elizabeth Reinhardt, Gary Dixon

JFSP Research Project Reports

This project provided for an improved version of the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS), a program whose original development was largely financed by the JFSP. The program is widely used by JFSP member agencies and several JFSP-sponsored research projects to support analysis at the stand to large landscape spatial scales. New research results rendered version 1 obsolete and experience with the model demonstrated that some parts of it needed to be improved. Equally important are issues regarding support, training, and system usability. We conducted 42 on-site training sessions over the last 4 years and also …


Does Prescribed Burning In Southern Forests Release Significant Amounts Of Mercury To The Atmosphere?, Thomas A. Waldrop, Mac A. Callahn, John A. Stanturf Jan 2009

Does Prescribed Burning In Southern Forests Release Significant Amounts Of Mercury To The Atmosphere?, Thomas A. Waldrop, Mac A. Callahn, John A. Stanturf

JFSP Research Project Reports

Mercury (Hg) emissions from prescribed fire present a potential impact on air quality that could motivate regulators to further restrict prescribed burning. Atmospheric deposition of Hg (originating from industrial sources) to forests is well documented, and the prescribed burning of two to four million acres per year in the South recycles an unknown (but potentially significant) amount of Hg into the atmosphere and surface waters by volatilization and post-fire runoff. This and other environmental concerns present a significant challenge to local land managers who use prescribed fire. Our objectives were (1) to estimate local and South-wide emission of Hg due …


Effect Of Mechanical Mastication Followed By Prescribed Fire On Mycorrhizas And Hypogeous Fungi In Mixed Hardwood Chaparral, Darlene Southworth, Jennifer Gibson, Jessica Donohue, Jonathan Frank, Kate Wagner, Jason Lambert, Acacia Baldner Jan 2009

Effect Of Mechanical Mastication Followed By Prescribed Fire On Mycorrhizas And Hypogeous Fungi In Mixed Hardwood Chaparral, Darlene Southworth, Jennifer Gibson, Jessica Donohue, Jonathan Frank, Kate Wagner, Jason Lambert, Acacia Baldner

JFSP Research Project Reports

The purpose of this study was to examine the effects of mechanical mastication followed by prescribed fire on mycorrhizal fungi and hypogeous sporocarps. A dense fire-prone mixed hardwood-conifer chaparral comprises a significant component of vegetation at Whiskeytown National Recreation Area. Prescribed burns, as fuel reduction treatments, are limited by air quality restrictions and narrow climatic conditions appropriate for burnings. Brush mastication is a fast and inexpensive tool commonly used by land managers to reduce ladder fuels. However, a dense layer of chipped debris remains, which, when burned, heats the soil more than ladder fuels. The upper layers of mineral soil …


Effects Of Prescribed Fire On Biological Soil Crusts And Their Subsequent Recovery In A Great Basin Juniper Woodland, Steven D. Warren, Larry L. St.Clair, Jeffrey R. Johansen, Paul Kugrens Jan 2009

Effects Of Prescribed Fire On Biological Soil Crusts And Their Subsequent Recovery In A Great Basin Juniper Woodland, Steven D. Warren, Larry L. St.Clair, Jeffrey R. Johansen, Paul Kugrens

JFSP Research Project Reports

A prescribed burn was conducted in a juniper woodland approximately 40 km south of Tooele, Utah on 05 October 2006. Conditions were sub-optimal, and the fire did not encroach into mid- or late-successional areas; only the early-successional area burned successfully. This study evaluated the effects of the prescribed burn on biological soil crusts that occupy the soil surface and are important for soil stability, soil nutrient cycling, and the germination and survival of vascular plants. Biological soil crusts are composed primarily of cyanobacteria, green algae, lichens and mosses. Mosses were rare under juniper trees, so the effects of the fire …


Effects Of Fuels/Fire Risk Reduction Treatments Using Hydro-Mow Or Thinning On Pinyon-Juniper Ecosystem Components Within The Wildland-Urbaninterface., Gerard J. Gottfried, Steven T. Overby, Philip A. Kemp, Cara Macmillan Jan 2009

Effects Of Fuels/Fire Risk Reduction Treatments Using Hydro-Mow Or Thinning On Pinyon-Juniper Ecosystem Components Within The Wildland-Urbaninterface., Gerard J. Gottfried, Steven T. Overby, Philip A. Kemp, Cara Macmillan

JFSP Research Project Reports

Pinyon-juniper woodlands are a dominant vegetation type throughout the Interior West on lands managed by the U.S. Forest Service and the USDI Bureau of Land Management. The woodlands have traditionally been viewed as having a low risk of wildfires because of the lack of a continuous and dense ground cover and low tree stand densities. However, stand densities are often high and are increasing in many areas and wildfires, often resulting in loss of lives and property, will occur under conditions of low humidity, high temperatures and wind speeds, and an ignition source. Woodlands commonly surround or are adjacent to …


Synthesis Of Knowledge On The Effects Of Fire And Fire Surrogates On Wildlife In U.S. Dry Forests, Patricia L. Kennedy, Joseph B. Fontaine Jan 2009

Synthesis Of Knowledge On The Effects Of Fire And Fire Surrogates On Wildlife In U.S. Dry Forests, Patricia L. Kennedy, Joseph B. Fontaine

JFSP Research Project Reports

Dry forests throughout the United States are fire-dependent ecosystems, and much attention has been given to restoring their ecological function. As such, land managers often are tasked with reintroducing fire via prescribed fire, wildland fire use, and fire-surrogate treatments such as thinning and mastication. During planning, managers frequently are expected to anticipate effects of management actions on wildlife species. This document represents a synthesis of existing knowledge on wildlife responses to fire and fire-surrogate treatments, presented in a useful, management-relevant format. Based on scoping meetings and dialogue with public lands managers from throughout the United States, we provide detailed, species-level, …


Synthesis Of Knowledge On The Effects Of Fire And Thinning Treatments On Understory Vegetation In U.S. Dry Forests, Anne M. Bartuszevige, Patricia L. Kennedy Jan 2009

Synthesis Of Knowledge On The Effects Of Fire And Thinning Treatments On Understory Vegetation In U.S. Dry Forests, Anne M. Bartuszevige, Patricia L. Kennedy

JFSP Research Project Reports

A century of fire exclusion in dry forests across the United States has resulted in high fuel loads and increasing dominance by fire-intolerant vegetation. Federal, state, and private agencies have adopted a goal of managing forests to reduce the risk of high-severity wildfire. Forest managers use a variety of tools to create desired conditions within forests; the most common are prescribed fire and mechanical thinning. These two treatments may be used separately or in combination, depending on restoration goals for the forest stand. Before these treatments can be applied, managers must justify their choice by documenting the effects of the …


Enhancing Western Managers’ Knowledge And Use Of Available Economic And Financial Biomass Information And Tools, Todd A. Morgan, Kenneth Skog, Greg Jones, Woodam Chung, Henry Spelter, John Baldridge, Jason Brandt, Dan Loeffler, Jon Songster Jan 2009

Enhancing Western Managers’ Knowledge And Use Of Available Economic And Financial Biomass Information And Tools, Todd A. Morgan, Kenneth Skog, Greg Jones, Woodam Chung, Henry Spelter, John Baldridge, Jason Brandt, Dan Loeffler, Jon Songster

JFSP Research Project Reports

The Joint Fire Science Program (JFSP) sponsored this study to enhance the ability of federal land managers to understand and deal with the economic and financial aspects of woody biomass removal as a component of fire hazard reduction treatments. The study objectives were to synthesize the body of economic and financial information and tools currently available to federal land managers in the West, identify managers’ information needs and disconnects from available information, and fill the gaps between existing information and tools versus managers’ awareness of available information and access to tools. The methods used for this study included 1) preparing …


Epidemic Southern Pine Beetle Attacks: A Problem Of Fuel-Loading Or An Opportunity For Management?, Thomas A. Waldrop, G. Geoffrey Wang, Knight Cox Jan 2009

Epidemic Southern Pine Beetle Attacks: A Problem Of Fuel-Loading Or An Opportunity For Management?, Thomas A. Waldrop, G. Geoffrey Wang, Knight Cox

JFSP Research Project Reports

The Piedmont Region of South Carolina experienced one of the heaviest attacks of southern pine beetle (Dendroctonus frontalis Zimm.) in history during the early part of this decade. Managers with both commercial objectives and restoration objectives needed information on how prescribed burning or mechanical treatments can be used to reduce the heavy fuels resulting from these attacks, without neglecting their primary management objectives. Prescribed burning is of concern because intensities are expected to be high and fires may damage soils, neighboring trees, or target vegetation. Methods of predicting fire behavior and fuel consumption are unavailable. Mechanical treatments will reduce fuels …


Estimating The Biomass Of Hand-Piled Fuels For Smoke Management Planning, Clinton S. Wright, Robert E. Vilnanek, James Russell, Mark Middy, Jim Bailey, Steve Davis, Robert Sanders, Cameron Balog, Paige Eagle Jan 2009

Estimating The Biomass Of Hand-Piled Fuels For Smoke Management Planning, Clinton S. Wright, Robert E. Vilnanek, James Russell, Mark Middy, Jim Bailey, Steve Davis, Robert Sanders, Cameron Balog, Paige Eagle

JFSP Research Project Reports

Dimensions, volume, and biomass were measured for 121 hand-constructed piles composed primarily of coniferous (n=61) and shrub/hardwood (n=60) material at sites in Washington and California. Equations using pile dimensions, shape, and type allow users to accurately estimate the biomass of hand piles. Equations for estimating true pile volume from simple geometric shapes and measurements of pile dimensions were also developed to allow users who require estimates of pile volume for regulatory reporting. Biomass and volume estimation equations are being programmed into a web-based calculator to allow users to estimate either value from pile dimensions.


Estimating Canopy Fuels And Their Impact On Potential Fire Behavior For Ponderosa Pine In The Black Hills, South Dakota., Frederick W. Smith, Tara Keyser, Wayne Shepperd Jan 2009

Estimating Canopy Fuels And Their Impact On Potential Fire Behavior For Ponderosa Pine In The Black Hills, South Dakota., Frederick W. Smith, Tara Keyser, Wayne Shepperd

JFSP Research Project Reports

We evaluate whether current procedures used in fire behavior prediction models such as FVS-FFE provide predictions of CBD and CBH suitable for evaluating fire behavior in response to fuel treatments. Currently, FFE-FVS uses a geographic non-specific set of tree allometries and assumes a uniform distribution of crown mass when estimating CBH and CBD. We develop allometric equations to predict crown mass specific to ponderosa pine in the Black Hills (Pinus ponderosa Dougl. ex Laws.) from a sample of 80 felled trees in 16 forest stands spanning a wide range in tree size and stand. We develop a non-uniform description of …


Ecological Effects Of Prescribed Fire Season: A Literature Review And Synthesis For Managers, Eric Knapp, Becky Estes, Carl N. Skinner Jan 2009

Ecological Effects Of Prescribed Fire Season: A Literature Review And Synthesis For Managers, Eric Knapp, Becky Estes, Carl N. Skinner

JFSP Research Project Reports

Prescribed burning may be conducted at times of the year when fires were infrequent historically, leading to concerns about potential adverse effects on vegetation and wildlife. Historical and prescribed fire regimes for different regions in the continental United States were compared and literature on season of prescribed burning synthesized. In regions and vegetation types where considerable differences in fuel consumption exist among burning seasons, the effects of prescribed fire season appears, for many ecological variables, to be driven more by fire-intensity differences among seasons than by phenology or growth stage of organisms at the time of fire. Where fuel consumption …


Reducing Fine Fuel Loads, Controlling Invasive Annual Grasses, And Manipulating Vegetation Composition In Zion Canyon, Utah, J. R. Matchett, Aviva O'Neill, Matt Brooks, Cheryl Decker, Jennifer Vollmer, Curt Deuser Jan 2009

Reducing Fine Fuel Loads, Controlling Invasive Annual Grasses, And Manipulating Vegetation Composition In Zion Canyon, Utah, J. R. Matchett, Aviva O'Neill, Matt Brooks, Cheryl Decker, Jennifer Vollmer, Curt Deuser

JFSP Research Project Reports

Fine fuels created by non-native annual grasses are a land management problem throughout the United States and beyond. These fuels facilitate the ignition of wildfires and promote their spread, creating hazardous fuel conditions in wildland urban interface areas. For example, fine fuel accumulations from non-native annual grasses in the riparian corridor at Zion National Park threaten the few egress routes from Zion Canyon, creating a threat to human life should a large wildfire occur there. In addition, when these non-native plants create novel fuel characteristics and fire behavior, they can lead to altered fire regimes that can significantly degrade natural …


A Regional Assessment Of The Ecological Effects Of Chipping And Mastication Fuels Reduction And Forest Restoration Treatments., Mike Battaglia, Charles Rhoades, Monique E. Rocca, Michael G. Ryan Jan 2009

A Regional Assessment Of The Ecological Effects Of Chipping And Mastication Fuels Reduction And Forest Restoration Treatments., Mike Battaglia, Charles Rhoades, Monique E. Rocca, Michael G. Ryan

JFSP Research Project Reports

Over the past several years, fire managers have increased their use of mastication treatments, the on-site disposal of shrubs and small-diameter trees through chipping and shredding. Mastication is a relatively untested management practice that alters the chemical and physical conditions of the forest floor and may influence vegetation regrowth and fuel development for years or decades. Eighteen sites were established across four ecosystems of the southern Rocky Mountains and the Colorado Plateau: lodgepole pine (Pinus contorta), mixed conifer (Pinus ponderosa, Pseudotsuga menziesii, Pinus flexilis, and Pinus contorta), ponderosa pine (Pinus ponderosa), and pinyon pine/juniper …


Conversion Of The Bluesky Framework Into Collaborative Web Service Architecture And Creation Of A Smoke Modeling Application, Narasimhan K. Larkin, Sean Raffuse, Daniel Pryden, Alan Healy, Kevin Unger, Tara Strand, Robert Solomon Jan 2009

Conversion Of The Bluesky Framework Into Collaborative Web Service Architecture And Creation Of A Smoke Modeling Application, Narasimhan K. Larkin, Sean Raffuse, Daniel Pryden, Alan Healy, Kevin Unger, Tara Strand, Robert Solomon

JFSP Research Project Reports

This project addresses the need for a collaborative architecture for scientific modeling that allows various scientific models to easily interact. The need for such a system has been documented by recent studies such as the JFSP Smoke Roundtables and the JFSP review of tools done by the Software Engineering Institute. This project addresses these needs by modifying the BlueSky Modeling Framework so that it can better serve as a collaborative architecture, and then utilizing this architecture to create an advanced application that could not otherwise be created. The BlueSky framework was modified for this purpose, and all changes integrated into …


Community Wildfire Protection Plans: Enhancing Collaboration And Building Social Capacity, Daniel R. Williams, Pamela J. Jakes, Sam Burns, Antony Cheng, Kristen Nelson, Victoria Sturtevant, Alex Bujak, Rachel Brummel, Stephanie Grayzeck Souter, Emily Saeli Staychock Jan 2009

Community Wildfire Protection Plans: Enhancing Collaboration And Building Social Capacity, Daniel R. Williams, Pamela J. Jakes, Sam Burns, Antony Cheng, Kristen Nelson, Victoria Sturtevant, Alex Bujak, Rachel Brummel, Stephanie Grayzeck Souter, Emily Saeli Staychock

JFSP Research Project Reports

The Healthy Forest Restoration Act of 2003 (HFRA) was enacted to reduce wildfire risk to communities and other at-risk lands through a collaborative process of planning, prioritizing and implementing hazardous fuel reduction projects. One of the key features of HFRA is the development of community wildfire protection plans (CWPPs). We studied the development of CWPPs in order to identify those factors and processes that consistently lead to effective collaborative fire and fuels management as defined by HFRA, and enhance local social capacity to sustain wildfire protection activities into the future. Findings from this research highlight the importance of: (1) drawing …


Characterizing Particulate Matter Emissions By Wildland Fires Relevant To Visibility Impairment And Pm Non-Attainment, William Malm, Douglas Fox, Hans Moosmüller, Sonia Kreidenweis, Jeffrey Collett Jr., Wei Min Hao Jan 2009

Characterizing Particulate Matter Emissions By Wildland Fires Relevant To Visibility Impairment And Pm Non-Attainment, William Malm, Douglas Fox, Hans Moosmüller, Sonia Kreidenweis, Jeffrey Collett Jr., Wei Min Hao

JFSP Research Project Reports

Carbonaceous aerosols, which include contributions from industrial and mobile source emissions and biomass combustion, exert a significant impact on regional air quality. Some preliminary semi-quantitative analyses suggest that smoke from fire-related activity may contribute significantly to observed organic mass concentrations. Further, these emissions have resulted in increased conflicts with the need to attain air quality standards, especially for particulate matter (PM) and visibility, as mandated by the Clean Air Act. However, federal land managers and policy makers currently lack several important tools needed for air quality assessments: composition profiles and analytical techniques necessary to differentiate carbonaceous aerosols originating from industrial …


Extending The Reach Of The Fire Effects Planning Framework By Taking A Critical Approach To Science Delivery And Application, Anne E. Black, Carol Miller, Vita Wright, Kate Walker, Carolyn Ballard, Paula Nasiatka, Brett Fay, Linda Chappell, Dave Calkin Jan 2009

Extending The Reach Of The Fire Effects Planning Framework By Taking A Critical Approach To Science Delivery And Application, Anne E. Black, Carol Miller, Vita Wright, Kate Walker, Carolyn Ballard, Paula Nasiatka, Brett Fay, Linda Chappell, Dave Calkin

JFSP Research Project Reports

The Fire Effects Planning Framework (FEPF), developed under JFSP project (99-1-3-16) “Wildland fuels management: evaluating and planning risks and benefits,” was formally completed in June 2004. FEPF is a logical framework that uses available data (e.g., local, LANDFIRE data) and existing software (e.g., GIS, Farsite, FlamMap, expert knowledge) to produce maps of probable fire effects during the pre-season or in advance of a fire front. The initial project included significant technology transfer activities. As that project concluded, however, we continued to receive requests for assistance from field managers (District, Forest and Regional Forest Service offices), international organizations (Interior West Fire …


A Chronosequence Feasibility Assessment Of Emergency Fire Rehabilitation Records Within The Intermountain Western United States, Kevin C. Knutson, David A. Pyke, Troy A. Wirth, David S. Pilliod, Matthew L. Brooks, Jeanne C. Chambers Jan 2009

A Chronosequence Feasibility Assessment Of Emergency Fire Rehabilitation Records Within The Intermountain Western United States, Kevin C. Knutson, David A. Pyke, Troy A. Wirth, David S. Pilliod, Matthew L. Brooks, Jeanne C. Chambers

JFSP Research Project Reports

Department of the Interior (DOI) bureaus have invested heavily (for example, the U.S. Bureau of Land Management (BLM) spent more than $60 million in fiscal year 2007) in seeding vegetation for emergency stabilization and burned area rehabilitation of non-forested arid lands over the past 10 years. The primary objectives of these seedings commonly are to (1) reduce the post-fire dominance of non-native annual grasses, such as cheatgrass (Bromus tectorum) and red brome (Bromus rubens); (2) minimize the probability of recurrent fire; and (3) ultimately produce desirable vegetation characteristics (for example, ability to recover following disturbance [resilience], resistance to invasive species, …


Fire And Fuels Management In Coast Redwood Forests, Steven P. Norman, J. Morgan Varner, Leonel Arguello, Stephen Underwood, Bradley Graham, Greg Jennings, Yana Valachovic, Christopher Lee Jan 2009

Fire And Fuels Management In Coast Redwood Forests, Steven P. Norman, J. Morgan Varner, Leonel Arguello, Stephen Underwood, Bradley Graham, Greg Jennings, Yana Valachovic, Christopher Lee

JFSP Research Project Reports

Coast redwood forests rank among the most significant natural features of North America, yet our understanding of how they came to be and how we might sustain them has been beset by scientific and management uncertainty for decades. A key part of this controversy has been the historical importance of fire given the mild coastal climate and small number of lightning ignitions. In the northern part of the coast redwood range, past research found that fire was uncommon, but results conflicted with others that found fire to be as frequent as in any dry forest of western North America. We …


Experimental Study Of Local Fire Conditions And Effects On Surface Or Near-Surface Archeological Resources At National Park Service Units – Midwest Region., Jay T. Sturdevant, Rod Skalsky, Cody L. Wienk, Brennan Dolan, Dustin Gonzalez, David Amrine Jan 2009

Experimental Study Of Local Fire Conditions And Effects On Surface Or Near-Surface Archeological Resources At National Park Service Units – Midwest Region., Jay T. Sturdevant, Rod Skalsky, Cody L. Wienk, Brennan Dolan, Dustin Gonzalez, David Amrine

JFSP Research Project Reports

Today, park managers must routinely balance the restoration needs of natural resources with the preservation of cultural resources. This project was designed to provide park managers with scientific data on the impacts from wildland fire to archeological resources at National Park Service units in the Midwest Region. Experimental research was conducted at six parks to record data on fire conditions (i.e., fuels, fire temperature, and burn duration) and the impacts on multiple classes of archeological materials routinely observed at sites within the region. The experimental study of fire conditions in different regional environments addresses questions regarding the threats or non-threats …


The Coming Transformation: Values To Sustain Human And Natural Communities, Stephen R. Kellert, James Gustave Speth Jan 2009

The Coming Transformation: Values To Sustain Human And Natural Communities, Stephen R. Kellert, James Gustave Speth

Yale School of the Environment Publications Series

No abstract provided.


The Dixmier-Douady Invariant For Dummies, Claude Schochet Jan 2009

The Dixmier-Douady Invariant For Dummies, Claude Schochet

Mathematics Faculty Research Publications

The Dixmier-Douady invariant is the primary tool in the classification of continuous trace C*-algebras. These algebras have come to the fore in recent years because of their relationship to twisted K-theory and via twisted K-theory to branes, gerbes, and string theory.

This note sets forth the basic properties of the Dixmier-Douady invariant using only classical homotopy and bundle theory. Algebraic topology enters the scene at once since the algebras in question are algebras of sections of certain fibre bundles.


Banach Algebras And Rational Homotopy Theory, Gregory Lupton, N. Christopher Phillips, Claude Schochet, Samuel B. Smith Jan 2009

Banach Algebras And Rational Homotopy Theory, Gregory Lupton, N. Christopher Phillips, Claude Schochet, Samuel B. Smith

Mathematics Faculty Research Publications

Let A be a unital commutative Banach algebra with maximal ideal space Max(A). We determine the rational H-type of GLn(A), the group of invertible n x n matrices with coefficients in A, in terms of the rational cohomology of Max(A). We also address an old problem of J. L. Taylor. Let Lcn(A) denote the space of "last columns" of GLn(A). We construct a natural isomorphism

Ȟs(Max(A);ℚ) ≅ π2n-1-s(Lcn(A)) ⊗ ℚ …


Barriers Encountered During Enrollment In An Internet-Mediated Randomized Controlled Trial, Lorraine R. Buis, Adrienne W. Janney, Michael L. Hess, Silas A. Culver, Caroline R. Richardson Jan 2009

Barriers Encountered During Enrollment In An Internet-Mediated Randomized Controlled Trial, Lorraine R. Buis, Adrienne W. Janney, Michael L. Hess, Silas A. Culver, Caroline R. Richardson

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Online technology is a promising resource for conducting clinical research. While the internet may improve a study's reach, as well as the efficiency of data collection, it may also introduce a number of challenges for participants and investigators. The objective of this research was to determine the challenges that potential participants faced during the enrollment phase of a randomized controlled intervention trial of Stepping Up to Health, an internet-mediated walking program that utilized a multi-step online enrollment process.

Methods

We conducted a quantitative content analysis of 623 help tickets logged in a participant management database during the enrollment …


A Search For Iron Emission Lines In The Chandra X-Ray Spectra Of Neutron Star Low-Mass X-Ray Binaries, E. M. Cackett, J. M. Miller, J. Homan, M. Van Der Klis, W. H. G. Lewin, M. Méndez, J. Raymond, D. Steeghs, R. Wijnands Jan 2009

A Search For Iron Emission Lines In The Chandra X-Ray Spectra Of Neutron Star Low-Mass X-Ray Binaries, E. M. Cackett, J. M. Miller, J. Homan, M. Van Der Klis, W. H. G. Lewin, M. Méndez, J. Raymond, D. Steeghs, R. Wijnands

Physics and Astronomy Faculty Research Publications

While iron emission lines are well studied in black hole systems, both in X-ray binaries and active galactic nuclei, there has been less of a focus on these lines in neutron star low-mass X-ray binaries (LMXBs). However, recent observations with Suzaku and XMM-Newton have revealed broad, asymmetric iron line profiles in three neutron star LMXBs, confirming an inner disk origin for these lines in neutron star systems. Here, we present a search for iron lines in six neutron star LMXBs. For each object we have simultaneous Chandra and RXTE observations at two separate epochs, allowing for both a high-resolution spectrum …


Hybrid Approximate Proximal Method With Auxiliary Variational Inequality For Vector Optimization, L C. Ceng, Boris S. Mordukhovich, Jen-Chih Yao Jan 2009

Hybrid Approximate Proximal Method With Auxiliary Variational Inequality For Vector Optimization, L C. Ceng, Boris S. Mordukhovich, Jen-Chih Yao

Mathematics Research Reports

This paper studies the general vector optimization problem of finding weakly efficient points for mappings in a Banach space Y, with respect to the partial order induced by a closed, convex, and pointed cone C C Y with nonempty interior. In order to find a solution of this problem, we introduce an auxiliary variational inequality problem for monotone, Lipschitz-continuous mapping. The approximate proximal method in vector optimization is extended to develop a hybrid approximate proximal method for the general vector optimization problem by the combination of extragradient method for finding a solution to the variational inequality problem and approximate proximal …


Nanofiltration Membrane Pilot Studies For Disinfection By-Product Control, Eric J. Lynne Jan 2009

Nanofiltration Membrane Pilot Studies For Disinfection By-Product Control, Eric J. Lynne

Electronic Theses and Dissertations

Watertown, South Dakota currently uses conventional softening to treat ground water to remove hardness, iron and manganese, and natural organic matter. The distribution system has experienced elevated concentrations of disinfection by-products, which will require additional treatment to comply with future limits set by the Stage 2 Disinfectant/Disinfection By-Products Rule. A nanofiltration membrane system has been proposed to remove additional natural organic matter from the softened water. Removing the natural organic material disinfection by-product precursors should reduce the concentration of disinfection by-products. The use of nanofiltration membranes has been previously documented to reject total organic carbon, while allowing desirable levels of …