Real-time Bacterial Detection by Single Cell Based Sensors UsingSynchrotron FTIR Spectromicroscopy (open access)

Real-time Bacterial Detection by Single Cell Based Sensors UsingSynchrotron FTIR Spectromicroscopy

Microarrays of single macrophage cell based sensors weredeveloped and demonstrated for real time bacterium detection bysynchrotron FTIR microscopy. The cells were patterned on gold-SiO2substrates via a surface engineering technique by which the goldelectrodes were immobilized with fibronectin to mediate cell adhesion andthe silicon oxide background were passivated with PEG to resist proteinadsorption and cell adhesion. Cellular morphology and IR spectra ofsingle, double, and triple cells on gold electrodes exposed tolipopolysaccharide (LPS) of different concentrations were compared toreveal the detection capabilities of these biosensors. The single-cellbased sensors were found to generate the most significant IR wave numbervariation and thus provide the highest detection sensitivity. Changes inmorphology and IR spectrum for single cells exposed to LPS were found tobe time- and concentration-dependent and correlated with each other verywell. FTIR spectra from single cell arrays of gold electrodes withsurface area of 25 mu-m2, 100 mu-m2, and 400 mu-m2 were acquired usingboth synchrotron and conventional FTIR spectromicroscopes to study thesensitivity of detection. The results indicated that the developedsingle-cell platform can be used with conventional FTIRspectromicroscopy. This technique provides real-time, label-free, andrapid bacterial detection, and may allow for statistic and highthroughput analyses, and portability.
Date: August 10, 2005
Creator: Veiseh, Mandana; Veiseh, Omid; Martin, Michael C.; Bertozzi, Carolyn & Zhang, Miqin
Object Type: Article
System: The UNT Digital Library
Cost-Reducing Methods for Thin Film Solid Oxide Fuel Cells (open access)

Cost-Reducing Methods for Thin Film Solid Oxide Fuel Cells

Lawrence Livermore National Laboratory (LLNL) has developed an improved method for fabrication of a thin film Solid Oxide Fuel Cell (SOFC) using a colloidal technique. Dense, crack-free, yttria-stabilized-zirconia (YSZ) films of up to 100 microns thick were deposited on nickel oxide/YSZ substrates and porous La{sub 0.85}Sr{sub 0.15}MnO{sub 3} (LSM) substrates. The new technique was also used to deposit a compositionally-graded film of YSZ and Ce{sub 0.8}Y{sub 0.2}O{sub 2} (CYO), which is useful for matching the thermal expansion coefficient to an adjacent layer. The SOFC is a solid-state electrochemical device that converts the chemical energy of fuel directly into electricity. Its efficiency and low emission positions SOFC on the short list of power generation technologies for the 21st century. However, commercialization efforts are hampered in part by the high cost of fabrication. One area of high cost is the fabrication of thin, defect free coatings. It is desirable to produce coatings that are in the range of 10-40 microns to minimize resistance yet maintain mechanical integrity. Deposition of films thicker than 10 microns in a single step using conventional techniques such as dip coating, spin coating, slurry painting or electrophoretic deposition generally results in cracking due to shrinkage when the solvent …
Date: August 10, 2005
Creator: Glass, R. S.
Object Type: Article
System: The UNT Digital Library
DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA (open access)

DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA

Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavement soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.
Date: August 10, 2005
Creator: Valentine, G.A. & Harrington, C.D.
Object Type: Report
System: The UNT Digital Library
Nuclear Level Densities for Modeling Nuclear Reactions: An Efficient Approach Using Statistical Spectroscopy (open access)

Nuclear Level Densities for Modeling Nuclear Reactions: An Efficient Approach Using Statistical Spectroscopy

The general goal of the project is to develop and implement computer codes and input files to compute nuclear densities of state. Such densities are important input into calculations of statistical neutron capture, and are difficult to access experimentally. In particular, we will focus on calculating densities for nuclides in the mass range A {approx} 50-100. We use statistical spectroscopy, a moments method based upon a microscopic framework, the interacting shell model. Second year goals and milestones: Develop two or three competing interactions (based upon surface-delta, Gogny, and NN-scattering) suitable for application to nuclei up to A = 100. Begin calculations for nuclides with A = 50-70.
Date: August 10, 2005
Creator: Johnson, Calvin W.
Object Type: Report
System: The UNT Digital Library
Balancing Cost and Risk: The Treatment of Renewable Energy in Western Utility Resource Plans (open access)

Balancing Cost and Risk: The Treatment of Renewable Energy in Western Utility Resource Plans

Markets for renewable energy have historically been motivated primarily by policy efforts, but a less widely recognized driver is poised to also play a major role in the coming years: utility integrated resource planning (IRP). Resource planning has re-emerged in recent years as an important tool for utilities and regulators, particularly in regions where retail competition has failed to take root. In the western United States, the most recent resource plans contemplate a significant amount of renewable energy additions. These planned additions--primarily coming from wind power--are motivated by the improved economics of wind power, a growing acceptance of wind by electric utilities, and an increasing recognition of the inherent risks (e.g., natural gas price risk, environmental compliance risk) in fossil-based generation portfolios. This report examines how twelve western utilities treat renewable energy in their recent resource plans. In aggregate, these utilities supply approximately half of all electricity demand in the western United States. Our purpose is twofold: (1) to highlight the growing importance of utility IRP as a current and future driver of renewable energy, and (2) to identify methodological/modeling issues, and suggest possible improvements to methods used to evaluate renewable energy as a resource option. Here we summarize the …
Date: August 10, 2005
Creator: Bolinger, Mark & Wiser, Ryan
Object Type: Report
System: The UNT Digital Library
Bambino: A Silicon Position-Sensitive Detector System for TIGRESS (open access)

Bambino: A Silicon Position-Sensitive Detector System for TIGRESS

Bambino is a charge-particle detector system with the capability to provide a sufficient energy and position resolution for recoiling nuclei with Z {le} 20 for the Doppler-shift corrections necessary to maintain the {gamma}-ray resolution in TIGRESS. It consists of two annular silicon detectors having an active inner diameter of 22 mm and outer diameter of 70 mm and a thickness of 140 {micro}m. They will be placed 3 cm from the target and provide solid-angle coverage of 1.15{pi} sr. It has 24 sectors in {theta} each for the angle coverage between from 20.1{sup o} to 49.4{sup o} and from 130.6{sup o} to 159.9{sup o} and 16 sectors in {phi} for 360{sup o} coverage. Three of those detectors have been ordered from Micron Semiconductor Ltd. and two were received so far. A split spherical target chamber will be built in Rochester to accommodate this detector system. The detector signals will travel through the custom-designed vacuum feedthrough and conversion board before reaching the preamplifier. The custom-made preamplifier has 8 channels in each unit with a gain of 10 mV/MeV. Ten of these have been ordered from Swan Research. They will be mechanically mounted on both the entrance and exit beam pipes to …
Date: August 10, 2005
Creator: Wu, C.; Becker, J. A. & Cline, D.
Object Type: Report
System: The UNT Digital Library
The Dynamic Range of Ultra-High Resolution Cryogenic Gamma-ray Spectrometers (open access)

The Dynamic Range of Ultra-High Resolution Cryogenic Gamma-ray Spectrometers

We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to multilayer Mo/Cu transition-edge sensors (TES). The energy resolution achieved with a 1 x 1 x 0.25 mm{sup 3} Sn absorber is 50 -90eV for {gamma}-rays up to 100 keV and it decreases for large absorber sizes. We discuss the trade-offs between energy resolution and dynamic range, as well as development of TES arrays for higher count rates and better sensitivity.
Date: August 10, 2005
Creator: Ali, S.; Terracol, S. F.; Drury, O. B. & Friedrich, S.
Object Type: Article
System: The UNT Digital Library
Integrated Modeling of Building Energy Requirements IncorporatingSolar Assisted Cooling (open access)

Integrated Modeling of Building Energy Requirements IncorporatingSolar Assisted Cooling

This paper expands on prior Berkeley Lab work on integrated simulation of building energy systems by the addition of active solar thermal collecting devices, technology options not previously considered (Siddiqui et al 2005). Collectors can be used as an alternative or additional source of hot water to heat recovery from reciprocating engines or microturbines. An example study is presented that evaluates the operation of solar assisted cooling at a large mail sorting facility in southern California with negligible heat loads and year-round cooling loads. Under current conditions solar thermal energy collection proves an unattractive option, but is a viable carbon emission control strategy.
Date: August 10, 2005
Creator: Firestone, Ryan; Marnay, Chris & Wang, Juan
Object Type: Article
System: The UNT Digital Library
High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders (open access)

High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing …
Date: August 10, 2005
Creator: Tantawi, S. G.; Nantista, C. D.; Dolgashev, V. A.; Pearson, C.; Nelson, J.; Jobe, K. et al.
Object Type: Article
System: The UNT Digital Library
Reconstruction of a 4D Particle Distribution Using UnderdeterminedPhase-Space Data (open access)

Reconstruction of a 4D Particle Distribution Using UnderdeterminedPhase-Space Data

A well defined 4D distribution that describes the transverse spatial coordinates (x,y) and momenta (x',y') of the particles that make up an intense ion beam is of great value to theorists in the field of particle beam physics. If such a distribution truthfully captures the characteristic of the actual beam, it can be used to initialize an extensive simulation, and can yield insight into the processes that affect beam quality. Creating a proper representative distribution of particles is a challenge because the problem is, in general, quite underdetermined. Data is collected through a pair of ''optical slit'' diagnostics which provide two 3D distributions, f(x,y,x') and f(x,y,y'); the challenge is to coalesce these into a full 4D distribution f(x,y,x',y'). Further difficulties are introduced because the data is collected at different longitudinal planes and must be ''remapped'' to a common plane, taking into account the convergence or divergence of the beam as well as any off-centering. This challenge was met by developing a suitable algorithm and implementing it as a ''plug-in'' for the popular scientific image analysis program ImageJ, written entirely in the Java programming language. The algorithm accomplishes the desired remapping and synthesizes a 4D particle distribution, using Monte-Carlo techniques. Preliminary …
Date: August 10, 2005
Creator: Rostamizadeh, Afshin
Object Type: Report
System: The UNT Digital Library
Membrane Inlet Mass Spectrometry for measuring dissolved gases (open access)

Membrane Inlet Mass Spectrometry for measuring dissolved gases

A Membrane Inlet Mass Spectrometer (MIMS) is used to measure dissolved gas concentrations in environmental water samples. Gases are exsolved out of water by passing the sample through a silicone gas permeable membrane that is under vacuum. A quadrupole mass spectrometer attached to the vacuum system is capable of measuring a variety of gases over a wide range of concentration. The MIMS is a versatile and field portable instrument.
Date: August 10, 2005
Creator: Singleton, M & Hudson, G
Object Type: Report
System: The UNT Digital Library
Structure, Function and Reconstitution of Antenna Complexes from Green Photosynthetic Bacteria (open access)

Structure, Function and Reconstitution of Antenna Complexes from Green Photosynthetic Bacteria

This project is concerned with the structure and function of the chlorosome antennas found in green photosynthetic bacteria. Chlorosomes are ellipsoidal structures attached to the cytoplasmic side of the inner cell membrane. These antenna complexes provide a very large absorption cross section for light capture. Evidence is overwhelming that the chlorosome represents a very different type of antenna from that found in any other photosynthetic system yet studied. It is now clear that chlorosomes do not contain traditional pigment-proteins, in which the pigments bind to specific sites on proteins. Instead, the chlorosome pigments are organized in vivo into pigment oligomers in which direct pigment-pigment interactions are of dominant importance. Our group has used a multidisciplinary approach to investigate this unique system, as well as the complexes that they directly interact with. Our work has included using model systems, numerous types of both steady-state and ultrafast spectroscopy, molecular biology, protein chemistry and X-ray crystallography. Details of our recent results using these approaches are given below and in the references. Numbers cited in the sections refer to DOE-sponsored publications that are listed below. Only publications dated 2001-2004 or later are included in this report. In addition to the primary literature reports, a …
Date: August 10, 2005
Creator: Blankenship, Robert E.
Object Type: Report
System: The UNT Digital Library
Development of Defoamers for Confinenment Foam (open access)

Development of Defoamers for Confinenment Foam

Aqueous foam concentrate (AFC) 380 foam was developed by Sandia National Laboratory as a blast mitigation foam for unexploded ordnance (UXO) and its ''engineered foam structure'' is reported to be able to ''envelop chemical or biological aerosols'' [1]. It is similar to commercial fire-fighting foams, consisting mostly of water with small amounts of two alcohols, an ether and surfactant. It also contains xanthan gum, probably, to strengthen the foam film and delay drainage. The concentrate is normally diluted in a 6:94 ratio with water for foaming applications. The diluted solution is normally foamed with air to an expansion factor of about 100 (density 0.01 g/cc), which is called ''dry'' foam. Higher density foam (0.18 > {rho} > 0.03 g/cc) was discovered which had quite different characteristics from ''dry'' foam and was called ''wet'' foam. Some characterization of these foams has also been carried out, but the major effort described in this document is the evaluation, at the small and medium scale, of chemical, mechanical and thermal approaches to defoaming AFC 380 foam. Several chemical approaches to defoaming were evaluated including oxidation and precipitation of the xanthan, use of commercial oil-emulsion or suspension defoamers, pH modification, and cation exchange with the …
Date: August 10, 2005
Creator: Hoffman, D. M. & Mitchell, A. R.
Object Type: Article
System: The UNT Digital Library