Addendum to High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant (open access)

Addendum to High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

As part of a small follow-on study, the burn rate of the ammonium perchlorate (AP) based material TAL-1503 was studied at a relatively mild pressure. The goal of this final experiment was to burn TAL-1503 at the lowest pressures possible using the LLNL High Pressure Strand Burner (LLNL-HPSB). The following is a description of the experiment and the results with a brief discussion of data and a comparison to the higher pressure data. This is not meant to be a stand-alone report and readers should refer to the main report for experimental details and discussion. High pressure deflagration rate measurements of a unique AP/HTPB based material (TAL-1503) were performed using the LLNL high pressure strand burner apparatus. The material burns in a well behaved, laminar fashion between 20 and 300 MPa with a burn law of B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} that was calculated based on the best data available from the experiments. In the pressure range of 2 and 10 MPa the material burned laminarly with a burn law of B = (2.0 {+-} 0.2) x P{sup (0.66{+-}0.05)}. In these results, B is the burn rate in mm/s and P is the pressure in units of …
Date: November 8, 2010
Creator: Glascoe, E A & Tan, N
Object Type: Report
System: The UNT Digital Library
CO2 Capture with Enzyme Synthetic Analogue (open access)

CO2 Capture with Enzyme Synthetic Analogue

Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.
Date: November 8, 2010
Creator: Cordatos, Harry
Object Type: Article
System: The UNT Digital Library
Comparison of leading parallel NAS file systems on commodity hardware (open access)

Comparison of leading parallel NAS file systems on commodity hardware

High performance computing has experienced tremendous gains in system performance over the past 20 years. Unfortunately other system capabilities, such as file I/O, have not grown commensurately. In this activity, we present the results of our tests of two leading file systems (GPFS and Lustre) on the same physical hardware. This hardware is the standard commodity storage solution in use at LLNL and, while much smaller in size, is intended to enable us to learn about differences between the two systems in terms of performance, ease of use and resilience. This work represents the first hardware consistent study of the two leading file systems that the authors are aware of.
Date: November 8, 2010
Creator: Hedges, R; Fitzgerald, K; Gary, M & Stearman, D M
Object Type: Report
System: The UNT Digital Library

Entering a New Stage of Learning from the U.S. Fuel Cell Electric Vehicle Demonstration Project

This presentation summarizes Entering a New Stage of Learning from the U.S. Fuel Cell Electric Vehicle Demonstration Project.
Date: November 8, 2010
Creator: Wipke, K.; Sprik, S.; Kurtz, J.; Ramsden, T. & Garbak, J.
Object Type: Presentation
System: The UNT Digital Library
Final Scientific Report, New Proton Conductive Composite Materials for PEM Fuel Cells (open access)

Final Scientific Report, New Proton Conductive Composite Materials for PEM Fuel Cells

This project covered one of the main challenges in present-day PEM fuel cell technology: to design a membrane capable of maintaining high conductivity and mechanical integrity when temperature is elevated and water vapor pressure is severely reduced. The DOE conductivity milestone of 0.1 S cm-1 at 120 degrees C and 50 % relative humidity (RH) for designed membranes addressed the target for the project. Our approach presumed to develop a composite membrane with hydrophilic proton-conductive inorganic material and the proton conductive polymeric matrix that is able to “bridge” the conduction paths in the membrane. The unique aspect of our approach was the use of highly functionalized inorganic additives to benefit from their water retention properties and high conductivity as well. A promising result turns out that highly hydrophilic phosphorsilicate gels added in Nafion matrix improved PEM fuel cell performance by over 50% compared with bare Nafion membrane at 120 degrees C and 50 % RH. This achievement realizes that the fuel cell operating pressure can be kept low, which would make the PEM fuel cell much more cost efficient and adaptable to practical operating conditions and facilitate its faster commercialization particularly in automotive and stationary applications.
Date: November 8, 2010
Creator: Lvov, Serguei
Object Type: Report
System: The UNT Digital Library
GLYCOLIC - FORMIC ACID FLOWSHEET DEVELOPMENT (open access)

GLYCOLIC - FORMIC ACID FLOWSHEET DEVELOPMENT

Flowsheet testing was performed to further develop the nitric/glycolic/formic acid flowsheet as an alternative to the nitric/formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be removed in the Sludge Receipt and Adjustment Tank (SRAT) with minimal hydrogen generation. All other processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Eight runs were performed in total, including the baseline run. The baseline nitric/formic flowsheet run was extremely difficult to process under existing DWPF acceptance criteria with this simulant at the HM levels of noble metals. While nitrite was destroyed and mercury was removed to near the DWPF limit, the rheology of the SRAT and SME products were well above design basis and hydrogen generation far exceeded the DWPF limit. In addition, mixing during the SME cycle was very poor. In this sense, the nitric/glycolic/formic acid flowsheet represents a significant upgrade over the current flowsheet. In the nitric/glycolic/formic flowsheet runs, mercury was successfully removed with almost no hydrogen generation and the SRAT and SME products yield stresses were within process limits or previously processed ranges. It is recommended that DWPF …
Date: November 8, 2010
Creator: Pickenheim, B.; Stone, M. & Newell, J.
Object Type: Report
System: The UNT Digital Library
Trends in U.S. Venture Capital Investments Related to Energy: 1980 through the Third Quarter of 2010 (open access)

Trends in U.S. Venture Capital Investments Related to Energy: 1980 through the Third Quarter of 2010

This report documents trends in U.S. venture capital investments over the period 1980 through the third quarter of calendar year 2010 (2010 Q1+Q2+Q3). Particular attention is given to U.S. venture capital investments in the energy/industrial sector over the period 1980-2010 Q1+Q2+Q3 as well as in the more recently created cross-cutting category of CleanTech over the period 1995-2010 Q1+Q2+Q3. During the early 1980s, U.S. venture capital investments in the energy/industrial sector accounted for more than 20% of all venture capital investments. However subsequent periods of low energy prices, the deregulation of large aspects of the energy industry, and the emergence of fast growing new industries like computers (both hardware and software), biotechnology and the Internet quickly reduced the priority accorded to energy/industrial investments. To wit, venture capital investments related to the energy/industrial sector accounted for only 1% of the $132 billion (in real 2010 US$) invested in 2000 by the U.S. venture capital community. The significant increase in the real price of oil that began in 2003-2004 correlates with renewed interest and increased investment by the venture capital community in energy/industrial investment opportunities. Venture capital investments for 2009 for the energy/industrial sector accounted for $2.4 billion or slightly more than 13% …
Date: November 8, 2010
Creator: Dooley, James J.
Object Type: Report
System: The UNT Digital Library