14th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes; Extended Abstracts and Papers (open access)

14th Workshop on Crystalline Silicon Solar Cells & Modules: Materials and Processes; Extended Abstracts and Papers

The 14th Workshop will provide a forum for an informal exchange of technical and scientific information between international researchers in the photovoltaic and relevant non-photovoltaic fields. It will offer an excellent opportunity for researchers in private industry and at universities to prioritize mutual needs for future collaborative research. The workshop is intended to address the fundamental properties of PV silicon, new solar cell designs, advanced solar cell processing techniques, and cell-related module issues. A combination of oral presentations by invited speakers, poster sessions, and discussion sessions will review recent advances in crystal growth, new cell designs, new processes and process characterization techniques, cell fabrication approaches suitable for future manufacturing demands, and solar cell encapsulation. This year's theme, ''Crystalline Si Solar Cells: Leapfrogging the Barriers,'' reflects the continued success of crystalline Si PV in overcoming technological barriers to improve solar cell performance and lower the cost of Si PV. The workshop will consist of presentations by invited speakers, followed by discussion sessions. In addition, there will be two poster sessions presenting the latest research and development results. Some presentations will address recent technologies in the microelectronics field that may have a direct bearing on PV. The sessions will include: Advances in …
Date: August 1, 2004
Creator: Sopori, B. L.
System: The UNT Digital Library
Application of NMR Methods to Identify Detection Reagents for Use in the Development of Robust Nanosensors (open access)

Application of NMR Methods to Identify Detection Reagents for Use in the Development of Robust Nanosensors

Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful technique for studying bi-molecular interactions at the atomic scale. Our NMR lab is involved in the identification of small molecules, or ligands that bind to target protein receptors, such as tetanus (TeNT) and botulinum (BoNT) neurotoxins, anthrax proteins and HLA-DR10 receptors on non-Hodgkin's lymphoma cancer cells. Once low affinity binders are identified, they can be linked together to produce multidentate synthetic high affinity ligands (SHALs) that have very high specificity for their target protein receptors. An important nanotechnology application for SHALs is their use in the development of robust chemical sensors or biochips for the detection of pathogen proteins in environmental samples or body fluids. Here, we describe a recently developed NMR competition assay based on transferred nuclear Overhauser effect spectroscopy (trNOESY) that enables the identification of sets of ligands that bind to the same site, or a different site, on the surface of TeNT fragment C (TetC) than a known ''marker'' ligand, doxorubicin. Using this assay, we can identify the optimal pairs of ligands to be linked together for creating detection reagents, as well as estimate the relative binding constants for ligands competing for the same site.
Date: April 29, 2004
Creator: Cosman, M; Krishnan, V V & Balhorn, R
System: The UNT Digital Library
Archaeofaunal insights on pinniped-human interactions in the northeastern Pacific (open access)

Archaeofaunal insights on pinniped-human interactions in the northeastern Pacific

Human exploitation of pinnipeds has considerable antiquity but shows increasing impacts on population numbers in the Holocene. Pinnipeds are a rich source of fat as well as protein. A few well-documented cases of regional extirpation of seals and sea lions by non-industrial peoples exist. The northeastern Pacific region, from southern California to Alaska, has yielded archaeological evidence for distributions and abundances of eared seals that differs markedly from historically documented biogeography. This is especially true of the northern fur seal (Callorhinus ursinus), among the most common pinnipeds in many archaeological sites from the Santa Barbara Channel area through to Kodiak Islands. This chapter reviews contemporary eared seal biogeography, evidence for the earlier timing and extent, of occurrence of northern fur seals along the northeastern Pacific coast, zooarchaeological and isotopic evidence for their foraging and probable maintenance of rookeries in lower latitudes, and for their disappearance from the southernmost part of their ancient distribution well before European contact. It also reviews ongoing debates over the behavioral ecology of ancient fur seals and over humans role in contributing to their disappearance.
Date: February 7, 2004
Creator: Gifford-Gonzales, D; Newsome, S; Koch, P; Guilderson, T; Snodgrass, J & Burton, R
System: The UNT Digital Library
Become One In A Million: Partnership Updates -- Million Solar Roofs and Interstate Renewable Energy Council (open access)

Become One In A Million: Partnership Updates -- Million Solar Roofs and Interstate Renewable Energy Council

The Million Solar Roofs Partnership Update is an annual report from all the Partnership and Partners who participate in the Million Solar Roofs Initiative.
Date: June 1, 2004
Creator: unknown
System: The UNT Digital Library
Biomass Cofiring in Coal-Fired Boilers (open access)

Biomass Cofiring in Coal-Fired Boilers

Cofiring biomass-for example, forestry residues such as wood chips-with coal in existing boilers is one of the easiest biomass technologies to implement in a federal facility. The current practice is to substitute biomass for up to 20% of the coal in the boiler. Cofiring has many benefits: it helps to reduce fuel costs as well as the use of landfills, and it curbs emissions of sulfur oxide, nitrogen oxide, and the greenhouse gases associated with burning fossil fuels. This Federal Technology Alert was prepared by the Department of Energy's Federal Energy Management Program to give federal facility managers the information they need to decide whether they should pursue biomass cofiring at their facilities.
Date: June 1, 2004
Creator: unknown
System: The UNT Digital Library
Bridging the Gap between Quantum Mechanics and Large-Scale Atomistic Simulation (open access)

Bridging the Gap between Quantum Mechanics and Large-Scale Atomistic Simulation

The prospect of modeling across disparate length and time scales to achieve a predictive multiscale description of real materials properties has attracted widespread research interest in the last decade. To be sure, the challenges in such multiscale modeling are many, and in demanding cases, such as mechanical properties or dynamic phase transitions, multiple bridges extending from the atomic level all the way to the continuum level must be built. Although often overlooked in this process, one of the most fundamental and important problems in multiscale modeling is that of bridging the gap between first-principles quantum mechanics, from which true predictive power for real materials emanates, and the large-scale atomistic simulation of thousands or millions of atoms, which is usually essential to describe the complex atomic processes that link to higher length and time scales. For example, to model single-crystal plasticity at micron length scales via dislocation-dynamics simulations that evolve the detailed dislocation microstructure requires accurate large-scale atomistic information on the mobility and interaction of individual dislocations. Similarly, modeling the kinetics of structural phase transitions requires linking accurate large-scale atomistic information on nucleation processes with higher length and time scale growth processes.
Date: August 16, 2004
Creator: Moriarty, J. A.
System: The UNT Digital Library
CFD Simulation of Airflow in Ventilated Wall System Report #9 (open access)

CFD Simulation of Airflow in Ventilated Wall System Report #9

The objective of this report was to examine air movements in vinyl and brick ventilation cavities in detail, using a state of the art CFD commercial modeling tool. The CFD activity was planned to proceed the other activities in order to develop insight on the important magnitudes of scales occurring during ventilation air flow. This information generated by the CFD model was to be used to modify (if necessary) and to validate the air flow dynamics already imbedded in the hygrothermal model for the computer-based air flow simulation procedures. A comprehensive program of advanced, state-of-the-art hygrothermal modeling was then envisaged mainly to extend the knowledge to other wall systems and at least six representative climatic areas. These data were then to be used to provide the basis for the development of design guidelines. CFD results provided timely and much needed answers to many of the concerns and questions related to ventilation flows due to thermal buoyancy and wind-driven flow scenarios. The relative strength between these two mechanisms. Simple correlations were developed and are presented in the report providing the overall pressure drop, and flow through various cavities under different exterior solar and temperature scenarios. Brick Rainscreen Wall: It was initially …
Date: January 1, 2004
Creator: Stovall, Therese K & Karagiozis, Achilles N
System: The UNT Digital Library
Correlation Profiles and Motifs in Complex Networks. (open access)

Correlation Profiles and Motifs in Complex Networks.

Networks have recently emerged as a unifying theme in complex systems research [1]. It is in fact no coincidence that networks and complexity are so heavily intertwined. Any future definition of a complex system should reflect the fact that such systems consist of many mutually interacting components. These components are far from being identical as say electrons in systems studied by condensed matter physics. In a truly complex system each of them has a unique identity allowing one to separate it from the others. The very first question one may ask about such a system is which other components a given component interacts with? This information system wide can be visualized as a graph, whose nodes correspond to individual components of the complex system in question and edges to their mutual interactions. Such a network can be thought of as a backbone of the complex system. Of course, system's dynamics depends not only on the topology of an underlying network but also on the exact form of interaction of components with each other, which can be very different in various complex systems. However, the underlying network may contain clues about the basic design principles and/or evolutionary history of the complex …
Date: January 16, 2004
Creator: Maslov, S.; Sneppen, K. & Alon, U.
System: The UNT Digital Library
Corrosion Behavior of Nickel Alloys in Wet Hydrofluoric Acid (open access)

Corrosion Behavior of Nickel Alloys in Wet Hydrofluoric Acid

Hydrofluoric acid is a water solution of hydrogen fluoride (HF). Hydrofluoric acid is used widely in diverse types of industrial applications; traditionally, it is used in pickling solutions in the metal industry, in the fabrication of chlorofluorocarbon compounds, as an alkylation agent for gasoline and as an etching agent in the industry of glass. In recent years, hydrofluoric acid has extensively been used in the manufacture of semiconductors and microelectronics during the wet chemical cleaning of silicon wafers. Hydrofluoric acid can be considered a reducing acid and although it is chemically classified as weaker than, for example, sulfuric or hydrochloric acids, it is extremely corrosive. This acid is also particularly toxic and poses greater health hazard than most other acids. The corrosion behavior of metals in hydrofluoric acid has not been as systematic studied in the laboratory as for other common inorganic acids. This is largely because tests using hydrofluoric acid cannot be run in standard equipment and because of the toxic nature of this acid. Moreover, short-term weight loss laboratory corrosion tests in hydrofluoric acid can be frustrating since the results are not as highly reproducible as in the case of other acids such as sulfuric or hydrochloric. One …
Date: February 6, 2004
Creator: Rebak, R. B.
System: The UNT Digital Library
DNA Damage Quantitation by Alkaline Gel Electrophoresis. (open access)

DNA Damage Quantitation by Alkaline Gel Electrophoresis.

Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by …
Date: March 24, 2004
Creator: Sutherland, B. M.; Bennett, P. V. & Sutherland, J. C.
System: The UNT Digital Library
Energy Design Guidelines for High Performance Schools: Arctic and Subarctic Climates (open access)

Energy Design Guidelines for High Performance Schools: Arctic and Subarctic Climates

The Energy Design Guidelines for High Performance Schools--Arctic and Subarctic Climates provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school in arctic and subarctic climates. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs.
Date: November 1, 2004
Creator: unknown
System: The UNT Digital Library
Energy Design Guidelines for High Performance Schools: Tropical Island Climates (open access)

Energy Design Guidelines for High Performance Schools: Tropical Island Climates

The Energy Design Guidelines for High Performance Schools--Tropical Island Climates provides school boards, administrators, and design staff with guidance to help them make informed decisions about energy and environmental issues important to school systems and communities. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school in tropical island climates. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs.
Date: November 1, 2004
Creator: unknown
System: The UNT Digital Library
Environmentally Assisted Cracking of Nickel Alloys (open access)

Environmentally Assisted Cracking of Nickel Alloys

Environmentally Assisted Cracking (EAC) is a general term that includes phenomena such as stress corrosion cracking (SCC), hydrogen embrittlement (HE), sulfide stress cracking (SSC), liquid metal embrittlement (LME), etc. EAC refers to a phenomenon by which a normally ductile metal looses its toughness (e.g. elongation to rupture) when it is subjected to mechanical stresses in presence of a specific corroding environment. For EAC to occur, three affecting factors must be present simultaneously. These include: (1) Mechanical tensile stresses, (2) A susceptible metal microstructure and (3) A specific aggressive environment. If any of these three factors is removed, EAC will not occur. That is, to mitigate the occurrence of EAC, engineers may for example eliminate residual stresses in a component or limit its application to certain chemicals (environment). The term environment not only includes chemical composition of the solution in contact with the component but also other variables such as temperature and applied potential. Nickel alloys are in general more resistant than stainless steels to EAC. For example, austenitic stainless steels (such as S30400) suffer SCC in presence of hot aqueous solutions containing chloride ions. Since chloride ions are ubiquitous in most industrial applications, the use of stressed stainless steels parts …
Date: February 6, 2004
Creator: Rebak, R. B.
System: The UNT Digital Library
Evaluation of the Compressed Air Challenge(R) Training Program (Executive Summary) (open access)

Evaluation of the Compressed Air Challenge(R) Training Program (Executive Summary)

The final report of the evaluation of the Compressed Air Challenge (CAC) Training Program. The training program is designed to provide plant personnel and compressed air system vendors with knowledge and tools required to effect improvements to the energy efficiency and overall performance of plant compressed air systems. As of May 2001, 3,029 individuals had attended the CAC Fundamentals of Compressed Air Training Systems and 925 individuals had attended ''Advanced Management of Compressed Air Systems''. These individuals represented 1,400-1,500 separate business establishments. The evaluation is based on three main research tasks: analysis of the CAC registration database, interviews with 100 end-user personnel who attended the CAC training, and interviews with 100 compressed air system vendors and consulting engineers who attended the training sessions.
Date: March 1, 2004
Creator: unknown
System: The UNT Digital Library
Extended Community: An Oral History of the Community Environmental Monitoring Program (CEMP), 1989 - 2003 (open access)

Extended Community: An Oral History of the Community Environmental Monitoring Program (CEMP), 1989 - 2003

Studying the Community Environmental Monitoring Program (CEMP) provides a unique opportunity to trace a concept created by two nuclear industry originators from inception, as it transitioned through several stewardship agencies, to management by a non-profit organization. This transition is informed not only by changes over two decades in the views of the general populace toward nuclear testing but also by changing political climates and public policies. Several parallel histories accompanied the development of the CEMP: an administrative history, an environmental history, and a history of changing public perception of not only nuclear testing, but other activities involving radiation such as waste transportation, as well. Although vital, those histories will be provided only as background to the subject of this study, the oral histories gathered in this project. The oral histories collected open a window into the nuclear testing history of Nevada and Utah that has not heretofore been opened. The nuclear industry has generated a great deal of positive and negative reaction since its inception. The CEMP emerged with specific objectives. It was designed to provide information to potential downwind communities and counter negative perceptions by creating more community involvement and education about the testing. The current objectives of the …
Date: July 1, 2004
Creator: DeSilva, Susan
System: The UNT Digital Library
Geothermal Today: 2003 Geothermal Technologies Program Highlights (Revised) (open access)

Geothermal Today: 2003 Geothermal Technologies Program Highlights (Revised)

This outreach publication highlights milestones and accomplishments of the DOE Geothermal Technologies Program for 2003. Included in this publication are discussions of geothermal fundamentals, enhanced geothermal systems, direct-use applications, geothermal potential in Idaho, coating technology, energy conversion R&D, and the GeoPowering the West initiative.
Date: May 1, 2004
Creator: unknown
System: The UNT Digital Library
Gold Cluster Labels and Related Technologies in Molecular Morphology. (open access)

Gold Cluster Labels and Related Technologies in Molecular Morphology.

Although intensely colored, even the largest colloidal gold particles are not, on their own, sufficiently colored for routine use as a light microscopy stain: only with very abundant antigens or with specialized illumination methods can bound gold be seen. Colloidal gold probes were developed primarily as markers for electron microscopy, for which their very high electron density and selectivity for narrow size distributions when prepared in different ways rendered them highly suited. The widespread use of gold labeling for light microscopy was made possible by the introduction of autometallographic enhancement methods. In these processes, the bound gold particles are exposed to a solution containing metal ions and a reducing agent; they catalyze the reduction of the ions, resulting in the deposition of additional metal selectively onto the particles. On the molecular level, the gold particles are enlarged up to 30-100 nm in diameter; on the macroscale level, this results in the formation of a dark stain in regions containing bound gold particles, greatly increasing visibility and contrast. The applications of colloidal gold have been described elsewhere in this chapter, we will focus on the use of covalently linked cluster complexes of gold and other metals. A gold cluster complex is …
Date: February 4, 2004
Creator: Hainfeld, J. F. & Powell, R. D.
System: The UNT Digital Library
High Pressure Materials Research: Novel Extended Phases of Molecular Triatomics (open access)

High Pressure Materials Research: Novel Extended Phases of Molecular Triatomics

Application of high pressure significantly alters the interatomic distance and thus the nature of intermolecular interaction, chemical bonding, molecular configuration, crystal structure, and stability of solid [1]. With modern advances in high-pressure technologies [2], it is feasible to achieve a large (often up to a several-fold) compression of lattice, at which condition material can be easily forced into a new physical and chemical configuration [3]. The high-pressure thus offers enhanced opportunities to discover new phases, both stable and metastable ones, and to tune exotic properties in a wide-range of atomistic length scale, substantially greater than (often being several orders of) those achieved by other thermal (varying temperatures) and chemical (varying composition or making alloys) means. Simple molecular solids like H{sub 2}, C, CO{sub 2}, N{sub 2}, O{sub 2}, H{sub 2}O, CO, NH{sub 3}, and CH{sub 4} are bounded by strong covalent intramolecular bonds, yet relatively weak intermolecular bonds of van der Waals and/or hydrogen bonds. The weak intermolecular bonds make these solids highly compressible (i.e., low bulk moduli typically less than 10 GPa), while the strong covalent bonds make them chemically inert at least initially at low pressures. Carbon-carbon single bonds, carbon-oxygen double bonds and nitrogen-nitrogen triple bonds, for example, …
Date: May 26, 2004
Creator: Yoo, C.
System: The UNT Digital Library
Hyperspectral Geobotanical Remote Sensing for CO2 Storage Monitoring (open access)

Hyperspectral Geobotanical Remote Sensing for CO2 Storage Monitoring

This project's goal is to develop remote sensing methods for early detection and spatial mapping, over whole regions simultaneously, of any surface areas under which there are significant CO2 leaks from deep underground storage formations. If large amounts of CO2 gas percolated up from a storage formation below to within plant root depth of the surface, the CO2 soil concentrations near the surface would become elevated and would affect individual plants and their local plant ecologies. Excessive soil CO2 concentrations are observed to significantly affect local plant and animal ecologies in our geothermal exploration, remote sensing research program at Mammoth Mountain CA USA. We also know from our geothermal exploration remote sensing programs, that we can map subtle hidden faults by spatial signatures of altered minerals and of plant species and health distributions. Mapping hidden faults is important because in our experience these highly localized (one to several centimeters) spatial pathways are good candidates for potentially significant CO2 leaks from deep underground formations. The detection and discrimination method we are developing uses primarily airborne hyperspectral, high spatial (3 meter) with 128 band wavelength resolution, visible and near infrared reflected light imagery. We also are using the newly available ''Quickbird'' satellite …
Date: May 14, 2004
Creator: Pickles, W & Cover, W
System: The UNT Digital Library
Improving Process Heating System Performance: A Sourcebook for Industry (open access)

Improving Process Heating System Performance: A Sourcebook for Industry

A sourcebook designed to provide process heating system users with a reference outlining opportunities to improve system performance and optimize energy efficiency in industrial energy systems.
Date: September 1, 2004
Creator: unknown
System: The UNT Digital Library
Improving Steam System Performance: A Sourcebook for Industry (open access)

Improving Steam System Performance: A Sourcebook for Industry

A sourcebook designed to provide steam system users with a reference outlining opportunities to improve system performance and optimize energy efficiency in industrial energy systems.
Date: October 1, 2004
Creator: unknown
System: The UNT Digital Library
Laser Fusion: The First Ten Years 1962-1972 (open access)

Laser Fusion: The First Ten Years 1962-1972

This account of the beginning of the program on laser fusion at Livermore in 1962, and its subsequent development during the decade ending in 1972, was originally prepared as a contribution to the January 1991 symposium 'Achievements in Physics' honoring Professor Keith Brueckner upon his retirement from the University of San Diego at La Jolla. It is a personal recollection of work at Livermore from my vantage point as its scientific leader, and of events elsewhere that I thought significant. This period was one of rapid growth in which the technology of high-power short-pulse lasers needed to drive the implosion of thermonuclear fuel to the temperature and density needed for ignition was developed, and in which the physics of the interaction of intense light with plasmas was explored both theoretically and experimentally.
Date: June 25, 2004
Creator: Kidder, R. E.
System: The UNT Digital Library
Magnetic Neutron Scattering (open access)

Magnetic Neutron Scattering

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron …
Date: July 30, 2004
Creator: Zaliznyak ,I. A. & Lee, S. H.
System: The UNT Digital Library
Modelling the Madden Julian Oscillation (open access)

Modelling the Madden Julian Oscillation

The MJO has long been an aspect of the global climate that has provided a tough test for the climate modelling community. Since the 1980s there have been numerous studies of the simulation of the MJO in atmospheric general circulation models (GCMs), ranging from Hayashi and Golder (1986, 1988) and Lau and Lau (1986), through to more recent studies such as Wang and Schlesinger (1999) and Wu et al. (2002). Of course, attempts to reproduce the MJO in climate models have proceeded in parallel with developments in our understanding of what the MJO is and what drives it. In fact, many advances in understanding the MJO have come through modeling studies. In particular, failure of climate models to simulate various aspects of the MJO has prompted investigations into the mechanisms that are important to its initiation and maintenance, leading to improvements both in our understanding of, and ability to simulate, the MJO. The initial focus of this chapter will be on modeling the MJO during northern winter, when it is characterized as a predominantly eastward propagating mode and is most readily seen in observations. Aspects of the simulation of the MJO will be discussed in the context of its sensitivity …
Date: May 21, 2004
Creator: Slingo, J. M.; Inness, P. M. & Sperber, K. R.
System: The UNT Digital Library