States

A 3-D model of superfluid helium suitable for numerical analysis (open access)

A 3-D model of superfluid helium suitable for numerical analysis

The two-fluid description is a very successful phenomenological representation of the properties of Helium II. A 3-D model suitable for numerical analysis based on the Landau-Khalatnikov description of Helium II is proposed. In this paper we introduce a system of partial differential equations that is both complete and consistent as well as practical, to be used for a 3-D solution of the flow of Helium II. The development of a 3-D numerical model for Helium II is motivated by the need to validate experimental results obtained by observing the normal component velocity distribution in a Helium II thermal counter-flow using the Particle Image Velocimetry (PIV) technique.
Date: January 1, 2008
Creator: Darve, C.; U., /Fermilab /Northwestern; Patankar, N.A.; U., /Northwestern; Van Sciver, S.W. & Lab., /Natl. High Mag. Field
Object Type: Article
System: The UNT Digital Library
20% Wind Energy by 2030 (open access)

20% Wind Energy by 2030

This analysis explores one clearly defined scenario for providing 20% of our nations electricity demand with wind energy by 2030 and contrasts it to a scenario of no new wind power capacity.
Date: July 1, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply; Executive Summary (Revised) (open access)

20% Wind Energy by 2030: Increasing Wind Energy's Contribution to U.S. Electricity Supply; Executive Summary (Revised)

This document is a 21-page summary of the 200+ page analysis that explores one clearly defined scenario for providing 20% of our nation's electricity demand with wind energy by 2030 and contrasts it to a scenario of no new U.S. wind power capacity.
Date: December 1, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
20% Wind Energy - Diversifying Our Energy Portfolio and Addressing Climate Change (Brochure) (open access)

20% Wind Energy - Diversifying Our Energy Portfolio and Addressing Climate Change (Brochure)

This brochure describes the R&D efforts needed for wind energy to meet 20% of the U.S. electrical demand by 2030. In May 2008, DOE published its report, 20% Wind Energy by 2030, which presents an in-depth analysis of the potential for wind energy in the United States and outlines a potential scenario to boost wind electric generation from its current production of 16.8 gigawatts (GW) to 304 GW by 2030. According to the report, achieving 20% wind energy by 2030 could help address climate change by reducing electric sector carbon dioxide (CO2) emissions by 825 million metric tons (20% of the electric utility sector CO2 emissions if no new wind is installed by 2030), and it will enhance our nation's energy security by diversifying our electricity portfolio as wind energy is an indigenous energy source with stable prices not subject to fuel volatility. According to the report, increasing our nation's wind generation could also boost local rural economies and contribute to significant growth in manufacturing and the industry supply chain. Rural economies will benefit from a substantial increase in land use payments, tax benefits and the number of well-paying jobs created by the wind energy manufacturing, construction, and maintenance industries. …
Date: May 1, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
200-BP-1 Prototype Hanford Barrier Annual Monitoring Report for Fiscal Years 2005 Through 2007 (open access)

200-BP-1 Prototype Hanford Barrier Annual Monitoring Report for Fiscal Years 2005 Through 2007

A prototype Hanford barrier was deployed over the 216-B-57 Crib at the Hanford Site in 1994 to prevent percolation through the underlying waste and to minimize spreading of buried contaminants. This barrier is being monitored to evaluate physical and hydrologic performance at the field scale. This report summarizes data collected during the period FY 2005 through FY 2007. In FY 2007, monitoring of the prototype Hanford barrier focused on barrier stability, vegetative cover, evidence of plant and animal intrusion, and the main components of the water balance, including precipitation, runoff, storage, drainage, and deep percolation. Owing to a hiatus in funding in FY 2005 through 2006, data collected were limited to automated measurements of the water-balance components. For the reporting period (October 2004 through September 2007) precipitation amount and distribution were close to normal. The cumulative amount of water received from October 1994 through September 2007 was 3043.45 mm on the northern half of the barrier, which is the formerly irrigated treatment, and 2370.58 mm on the southern, non-irrigated treatments. Water storage continued to show a cyclic pattern, increasing in the winter and declining in the spring and summer to a lower limit of around 100 mm in response to …
Date: February 1, 2008
Creator: Ward, Andy L.; Link, Steven O.; Strickland, Christopher E.; Draper, Kathryn E. & Clayton, Ray E.
Object Type: Report
System: The UNT Digital Library
219-S CORROSION STUDY (open access)

219-S CORROSION STUDY

A minor leak was detected in a drain line for Hood 2B located in the 222-S Laboratory. The line transfers radioactive waste, spent analytical standards, and chemicals used in various analytical procedures. Details are in the report provided by David Comstock, 2B NDE June 2008, work package LAB-WO-07-2012. Including the noted leak, the 222-S Laboratory has experienced two drain line leaks in approximately the last two years of operation. As a consequence, CH2M HILL Hanford Group, Inc. (CH2M HILL) requested the support of ChemMet, Ltd., PC (ChemMet) at the Hanford Site 222-S Laboratory. The corrosion expertise from ChemMet was required prior to preparation of a compatibility assessment for the 222-S Laboratory waste transfer system to assure the expected life of the piping system is extended as much as practicable. The system includes piping within the 222-S Laboratory and the 219-S Waste Storage and Transfer Facility and Operations Process. The ChemMet support was required for an assessment by 222-S staff to analyze what improvements to operational activities may be implemented to extend the tank/piping system life. This assessment will include a summary of the various material types, age, and locations throughout the facility. The assessment will also include a discussion of …
Date: December 1, 2008
Creator: Divine, James R. & Parsons, G. L.
Object Type: Report
System: The UNT Digital Library
300 Area VOC Program Slug Test Characterization Results for Selected Test/Depth Intervals for Wells 399-2-5, 399-3-22, and 399-4-14 (open access)

300 Area VOC Program Slug Test Characterization Results for Selected Test/Depth Intervals for Wells 399-2-5, 399-3-22, and 399-4-14

Multiple, stress-level slug tests were performed at selected test/depth intervals within wells 399-2-5, 399-3-22, and 399-4-14 as part of the 300 Area volatile organic compound characterization program at the Hanford Site in Washington State. The temporary test screen lengths were characterized as the boreholes were advanced to their final drill depths and before their completion as monitor-well facilities. Following well completion, slug tests were performed in the final, completed well-screen sections. The objectives of the slug tests were to provide the vertical distribution of hydraulic conductivity with depth at these locations and to support selection of the final well screen-depth interval for each of these monitor-well facilities.
Date: March 1, 2008
Creator: Newcomer, Darrell R.
Object Type: Report
System: The UNT Digital Library
2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material (open access)

2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material

Most recent improvements in building envelope technologies suggest that in the near future, residences will be routinely constructed to operate with very low heating and cooling loads. In that light, the application of novel building materials containing active thermal components (e.g., phase change materials [PCMs,] sub-venting, radiant barriers, and integrated hydronic systems) is like a final step in achieving relatively significant heating and cooling energy savings from technological improvements in the building envelope. It is expected that optimized building envelope designs using PCMs for energy storage can effectively bring notable savings in energy consumption and reductions in peak hour power loads. During 2006/07, a research team at Oak Ridge National Laboratory (ORNL) performed a series of laboratory and field tests of several wall and roof assemblies using PCM-enhanced cellulose insulation. This report summarizes the test results from the perspective of energy performance. The ORNL team is working on both inorganic and organic PCMs; this report discusses only paraffinic PCMs. A limited economical analysis also is presented. PCMs have been tested as a thermal mass component in buildings for at least 40 years. Most of the research studies found that PCMs enhanced building energy performance. In the case of the application …
Date: December 1, 2008
Creator: Kosny, Jan; Yarbrough, David W; Miller, William A; Petrie, Thomas; Childs, Phillip W & Syed, Azam M
Object Type: Report
System: The UNT Digital Library
2007 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada (open access)

2007 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada

This report summarizes the results of an annual review of conditions affecting the operation of the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) and a determination of the continuing adequacy of the performance assessments (PAs) and composite analyses (CAs). The Area 5 RWMS PA documentation consists of the original PA (Shott et al., 1998), referred to as the 1998 Area 5 RWMS PA and supporting addenda (Bechtel Nevada [BN], 2001b; 2006a). The Area 5 RWMS CA was issued as a single document (BN, 2001a) and has a single addendum (BN, 2001c). The Area 3 PA and CA were issued in a single document (Shott et al., 2000). The Maintenance Plan for the PAs and CAs (National Security Technologies, LLC [NSTec], 2006) and the Disposal Authorization Statements (DASs) for the Area 3 and 5 RWMSs (U.S. Department of Energy [DOE], 2000; 2002) require preparation of an annual summary and a determination of the continuing adequacy of the PAs and CAs. The annual summary report is submitted to DOE Headquarters. Following the annual report format in the DOE PA/CA Maintenance Guide (DOE, 1999), this report presents the annual summary for the PAs in Section 2.0 and the CAs in …
Date: January 1, 2008
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
2007 Inorganic Reaction Mechanisms Gordon Research Conference-February 18-23 (open access)

2007 Inorganic Reaction Mechanisms Gordon Research Conference-February 18-23

This conference focuses on kinetic, mechanistic, and thermodynamic studies of reactions that play a role in fields as diverse as catalysis, energy, bioinorganic chemistry, green chemistry, organometallics, and activation of small molecules (oxygen, nitrogen, carbon monoxide, carbon dioxide, alkanes). Participants from universities, industry, and national laboratories present results and engage in discussions of pathways, intermediates, and outcome of various reactions of inorganic, organic, coordination, organometallic, and biological species. This knowledge is essential for rational development and design of novel reactions, compounds, and catalysts.
Date: January 1, 2008
Creator: Gray, Andreja Bakac Nancy Ryan
Object Type: Article
System: The UNT Digital Library
2007 Microbial Population Biology (July 22-26, 2007) (open access)

2007 Microbial Population Biology (July 22-26, 2007)

Microbial Population Biology covers a diverse range of cutting edge issues in the microbial sciences and beyond. Firmly founded in evolutionary biology and with a strongly integrative approach, past meetings have covered topics ranging from the dynamics and genetics of adaptation to the evolution of mutation rate, community ecology, evolutionary genomics, altruism, and epidemiology. This meeting is never dull: some of the most significant and contentious issues in biology have been thrashed out here. We anticipate the 2007 meeting being no exception. The final form of the 2007 meeting is yet to be decided, but the following topics are likely to be included: evolutionary emergence of infectious disease and antibiotic resistance, genetic architecture and implications for the evolution of microbial populations, ageing in bacteria, biogeography, evolution of symbioses, the role of microbes in ecosystem function, and ecological genomics.
Date: April 1, 2008
Creator: Dean, Anthony M. & Gray, Nancy Ryan
Object Type: Article
System: The UNT Digital Library
2007 Radiation & Climate GRC ( July 29-August 3, 2007) (open access)

2007 Radiation & Climate GRC ( July 29-August 3, 2007)

The theme of the fifth Gordon Research Conference on Radiation and Climate is 'Integrating multiscale measurements and models for key climate questions'. The meeting will feature lectures, posters, and discussion regarding these issues. The meeting will focus on insights from new types of satellite and in situ data and from new approaches to modeling processes in the climate system. The program on measurements will highlight syntheses of new satellite data on cloud, aerosols, and chemistry and syntheses of satellite and sub-orbital observations from field programs. The program on modeling will address both the evaluation of cloud-resolving and regional aerosol models using new types of measurements and the evidence for processes and physics missing from global models. The Conference will focus on two key climate questions. First, what factors govern the radiative interactions of clouds and aerosols with regional and global climate? Second, how well do we understand the interaction of radiation with land surfaces and with the cryosphere?
Date: June 1, 2008
Creator: Gray, William Collins Nancy Ryan
Object Type: Article
System: The UNT Digital Library
2007 Renewable Energy: Solar Fuels Gordon Research Conference - January 21-26 (open access)

2007 Renewable Energy: Solar Fuels Gordon Research Conference - January 21-26

This Gordon Research Conference seeks to brings together chemists, physicists, materials scientists and biologists to address perhaps the outstanding technical problem of the 21st Century - the efficient, and ultimately economical, storage of energy from carbon-neutral sources. Such an advance would deliver a renewable, environmentally benign energy source for the future. A great technological challenge facing our global future is energy. The generation of energy, the security of its supply, and the environmental consequences of its use are among the world's foremost geopolitical concerns. Fossil fuels - coal, natural gas, and petroleum - supply approximately 90% of the energy consumed today by industrialized nations. An increase in energy supply is vitally needed to bring electric power to the 25% of the world's population that lacks it, to support the industrialization of developing nations, and to sustain economic growth in developed countries. On the geopolitical front, insuring an adequate energy supply is a major security issue for the world, and its importance will grow in proportion to the singular dependence on oil as a primary energy source. Yet, the current approach to energy supply, that of increased fossil fuel exploration coupled with energy conservation, is not scaleable to meet future demands. …
Date: February 1, 2008
Creator: Nocera, Daniel G.
Object Type: Article
System: The UNT Digital Library
2007 Site Environmental Report (open access)

2007 Site Environmental Report

Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in this volume in Chapter 7, Groundwater Protection. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc …
Date: October 1, 2008
Creator: Ratel,K.
Object Type: Report
System: The UNT Digital Library
2007 Status of Manufacturing: Polymer Electrolyte Membrane (PEM) Fuel Cells (open access)

2007 Status of Manufacturing: Polymer Electrolyte Membrane (PEM) Fuel Cells

In this document we assess the North American industry's current ability to manufacture polymer electrolyte membrane (PEM) fuel cells.
Date: March 1, 2008
Creator: Wheeler, D. & Sverdrup, G.
Object Type: Report
System: The UNT Digital Library

2008 Solar Annual Review Meeting, Session: Parabolic Troughs

The project description is R and D activities at NREL and Sandia aimed at lowering the delivered energy cost of parabolic trough collector systems and FOA awards to support industry in trought development. The primary objectives are: (1) support development of near-term parabolic trought technology for central station power generation; (2) support development of next-generation trought fields; and (3) support expansion of US trough industry. The major FY08 activities were: (1) improving reflector optics; (2) reducing receiver heat loss (including improved receiver coating and mitigating hydrogen accumulation); (3) measuring collector optical efficiency; (4) optimizing plant performance and reducing cost; (5) reducing plant water consumption; and (6) directly supporting industry needs, including FOA support.
Date: April 1, 2008
Creator: Kutscher, Chuck
Object Type: Presentation
System: The UNT Digital Library
2008 Summer Research Institute Interfacial and Condensed Phase Chemical Physics Annual Report (open access)

2008 Summer Research Institute Interfacial and Condensed Phase Chemical Physics Annual Report

For the fifth year, the Pacific Northwest National Laboratory in Richland, Washington, invited graduate students, postdoctoral fellows, university faculty, and students entering graduate students from around the world to participate in the Summer Research Institute in Interfacial and Condensed Phase Chemical Physics. The institute offers participants the opportunity to gain hands-on experience in top-notch research laboratories while working along internationally respected mentors. Of the 38 applicants, 20 were accepted for the 8- to 10-week program. The participants came from universities as close as Seattle and Portland and as far away as Germany and Singapore. At Pacific Northwest National Laboratory, the 20 participants were mentored by 13 scientists. These mentors help tailor the participant’s experience to the needs of that person. Further, the mentors provide guidance on experimental and theoretical techniques, research design and completion, and other aspects of scientific careers in interfacial and condensed phase chemical physics. The research conducted at the institute can result in tangible benefits for the participants. For example, many have co-authored papers that have been published in peer-reviewed journals, including top-rated journals such as Science. Also, they have presented their research at conferences, such as the Gordon Research Conference on Dynamics at Surfaces and the …
Date: November 1, 2008
Creator: Garrett, Bruce C.; Tonkyn, Russell G. & Avery, Nachael B.
Object Type: Report
System: The UNT Digital Library
20th International Training Course (ITC-20) on the physical protection of nuclear facilities and materials evaluation report. (open access)

20th International Training Course (ITC-20) on the physical protection of nuclear facilities and materials evaluation report.

The goal of this evaluation report is to provide the information necessary to improve the effectiveness of the ITC provided to the International Atomic Energy Agency Member States. This report examines ITC-20 training content, delivery methods, scheduling, and logistics. Ultimately, this report evaluates whether the course provides the knowledge and skills necessary to meet the participants needs in the protection of nuclear materials and facilities.
Date: September 1, 2008
Creator: Ramirez, Amanda Ann
Object Type: Report
System: The UNT Digital Library
A 2D Benchmark for the Verification of the PEBBED Code (open access)

A 2D Benchmark for the Verification of the PEBBED Code

A new benchmarking concept is presented for verifying the PEBBED 3D multigroup finite difference/nodal diffusion code with application to pebble bed modular reactors (PBMRs). The key idea is to perform convergence acceleration, also called extrapolation to zero discretization, of a basic finite difference numerical algorithm to give extremely high accuracy. The method is first demonstrated on a 1D cylindrical shell and then on an r,8 wedge where the order of the second order finite difference scheme is confirmed to four places.
Date: September 1, 2008
Creator: Ganapol, Barry D.; Gougar, Hans A. & Ougouag, A. O.
Object Type: Article
System: The UNT Digital Library
3D CFD Electrochemical and Heat Transfer Model of an Integrated-Planar Solid Oxide Electrolysis Cells (open access)

3D CFD Electrochemical and Heat Transfer Model of an Integrated-Planar Solid Oxide Electrolysis Cells

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in a new novel integrated planar porous-tube supported solid oxide electrolysis cell (SOEC). The model is of several integrated planar cells attached to a ceramic support tube. This design is being evaluated with modeling at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plots …
Date: October 1, 2008
Creator: Hawkes, Grant & O'Brien, James E.
Object Type: Article
System: The UNT Digital Library
4th Generation ECR Ion Sources (open access)

4th Generation ECR Ion Sources

The concepts and technical challenges related to developing a 4th generation ECR ion source with an RF frequency greater than 40 GHz and magnetic confinement fields greater than twice Becr will be explored in this paper. Based on the semi-empirical frequency scaling of ECR plasma density with the square of operating frequency, there should be significant gains in performance over current 3rd generation ECR ion sources, which operate at RF frequencies between 20 and 30 GHz. While the 3rd generation ECR ion sources use NbTi superconducting solenoid and sextupole coils, the new sources will need to use different superconducting materials such as Nb3Sn to reach the required magnetic confinement, which scales linearly with RF frequency. Additional technical challenges include increased bremsstrahlung production, which may increase faster than the plasma density, bremsstrahlung heating of the cold mass and the availability of high power continuous wave microwave sources at these frequencies. With each generation of ECR ion sources, there are new challenges to be mastered, but the potential for higher performance and reduced cost of the associated accelerator continue to make this a promising avenue for development.
Date: December 1, 2008
Creator: Lyneis, Claude M.; Leitner, D.; Todd, D.S.; Sabbi, G.; Prestemon, S.; Caspi, S. et al.
Object Type: Article
System: The UNT Digital Library
7th Annual Systems Biology Symposium: Systems Biology and Engineering (open access)

7th Annual Systems Biology Symposium: Systems Biology and Engineering

Systems biology recognizes the complex multi-scale organization of biological systems, from molecules to ecosystems. The International Symposium on Systems Biology has been hosted by the Institute for Systems Biology in Seattle, Washington, since 2002. The annual two-day event gathers the most influential researchers transforming biology into an integrative discipline investingating complex systems. Engineering and application of new technology is a central element of systems biology. Genome-scale, or very small-scale, biological questions drive the enigneering of new technologies, which enable new modes of experimentation and computational analysis, leading to new biological insights and questions. Concepts and analytical methods in engineering are now finding direct applications in biology. Therefore, the 2008 Symposium, funded in partnership with the Department of Energy, featured global leaders in "Systems Biology and Engineering."
Date: April 1, 2008
Creator: Galitski, Timothy P.
Object Type: Article
System: The UNT Digital Library
Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory (open access)

Aberration-Coreected Electron Microscopy at Brookhaven National Laboratory

The last decade witnessed the rapid development and implementation of aberration correction in electron optics, realizing a more-than-70-year-old dream of aberration-free electron microscopy with a spatial resolution below one angstrom [1-9]. With sophisticated aberration correctors, modern electron microscopes now can reveal local structural information unavailable with neutrons and x-rays, such as the local arrangement of atoms, order/disorder, electronic inhomogeneity, bonding states, spin configuration, quantum confinement, and symmetry breaking [10-17]. Aberration correction through multipole-based correctors, as well as the associated improved stability in accelerating voltage, lens supplies, and goniometers in electron microscopes now enables medium-voltage (200-300kV) microscopes to achieve image resolution at or below 0.1nm. Aberration correction not only improves the instrument's spatial resolution but, equally importantly, allows larger objective lens pole-piece gaps to be employed thus realizing the potential of the instrument as a nanoscale property-measurement tool. That is, while retaining high spatial resolution, we can use various sample stages to observe the materials response under various temperature, electric- and magnetic- fields, and atmospheric environments. Such capabilities afford tremendous opportunities to tackle challenging science and technology issues in physics, chemistry, materials science, and biology. The research goal of the electron microscopy group at the Dept. of Condensed Matter Physics and …
Date: April 1, 2008
Creator: Zhu, Y. & Wall, J.
Object Type: Book
System: The UNT Digital Library
Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization. (open access)

Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization.

Abstract: Increased forest productivity has been obtained by improving resource availability through water and nutrient amendments. However, more stress-tolerant species that have robust site requirements do not respond consistently to irrigation. An important factor contributing to robust site requirements may be the distribution of biomass belowground, yet available information is limited. We examined the accumulation and distribution of above- and below-ground biomass in sweetgum (Liqrridambar sfyrac$lua L.) and loblolly pine (Pinus taeda L.) stands receiving irrigation and fertilization. Mean annual aboveground production after 4 years ranged from 2.4 to 5.1 ~g.ha-'.year' for sweetgum and from 5.0 to 6.9 ~g.ha-l.year-l for pine. Sweetgum responded positively to irrigation and fertilization with an additive response to irrigation + fertilization. Pine only responded to fertilization. Sweetgum root mass fraction (RME)in creased with fertilization at 2 years and decreased with fertilization at 4 years. There were no detectable treatment differences in loblolly pine RMF. Development explained from 67% to 98% of variation in shoot versus root allometry for ephemeral and perennial tissues, fertilization explained no more than 5% of the variation in for either species, and irrigation did not explain any. We conclude that shifts in allocation from roots to shoots do not explain nutrient-induced …
Date: April 1, 2008
Creator: Coyle, David, R.; Coleman, Mark, D. & Aubrey, Doug, P.
Object Type: Article
System: The UNT Digital Library