National Library of Energy BETA

Sample records for fluorescent compact fluorescent

  1. High lumen compact fluorescents boost light output in new fixtures

    SciTech Connect (OSTI)

    1992-12-31

    Some compact fluorescent lamps aren`t so compact. General Electric (GE), OSRAM, and Philips have been expanding offerings in longer, more powerful, hard wired CFLs that generate enough light to serve applications once limited to conventional fluorescents and metal halide systems. All three of these manufacturers have for some time offered 18- to 40-watt high-output CFLs, which use a fluorescent tube doubled back on itself to produce a lot of light in a compact source. Now GE has introduced an even larger, more powerful 50-watt unit, and OSRAM is soon to follow suit with a 55-watt lamp. These new entries to the field of turbocharged CFLs can provide general lighting at ceiling heights of 12 feet or more as well as indirect lighting, floodlighting, and wall washing. They are such a concentrated source of light that they can provide the desired illumination using fewer lamps and fixtures than would be needed with competing sources.

  2. Convection venting lensed reflector-type compact fluorescent lamp system

    DOE Patents [OSTI]

    Pelton, B.A.; Siminovitch, M.

    1997-07-29

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures. 12 figs.

  3. Conservation potential of compact fluorescent lamps in India and Brazil

    SciTech Connect (OSTI)

    Gadgil, A.; Martino Jannuzzi, G. de (Lawrence Berkeley Lab., CA (USA); Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia)

    1989-07-01

    We evaluate the conservation potential of compact fluorescent lamps (CFLs) for managing the rapidly increasing electrical energy and peak demand in India and Brazil. Using very conservative assumptions, we find that the cost of conserved energy using 16 W CFLs is 4 and 6 times less than the long range marginal cost of electricity for the two countries. The cost of avoided peak installed capacity is 6 and 9.5 times less than the cost of new installed capacity for India and Brazil. The analysis is undertaken from the three separate perspectives of the national economies, the consumers, and the utilities. We find that because residential electricity is subsidized, the consumers have little or no incentive to purchase and install the CFLs, unless they too are subsidized. However, the benefits of CFL installation to the utility are so large that subsidizing them is a paying proposition for the utility are so large that subsidizing them is a paying proposition for the utility in almost all cases. As an illustration of a gradual introduction strategy for CFLs, we calculate a scenario where national savings of the order of US $1.2 million per day for India and US $2.5 million per day for Brazil are reached in 10 years by a small and gradual transfer of subsidy from residential electricity to CFLs. We then explore the barriers to immediate large scale introduction of these lamps in the two countries. Specific technical and marketing problems are identified and discussed, which would require solution before such an introduction can be attempted. Lastly, we discuss the range of policy instruments, in addition to a subsidy scheme, that can be used for promoting the diffusion of these lamps in the domestic and commercial sector. 47 refs., 15 figs., 2 tabs.

  4. Compact Fluorescent Plug-In Ballast-in-a-Socket

    SciTech Connect (OSTI)

    Rebecca Voelker

    2001-12-21

    The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated that they would pay as much as an additional $10 for a lamp containing such a ballast. The ballast has been optimized to run with a 26 W amalgam triple biax lamp in the base-down position, yet can accept non-amalgam versions of the lamp. With a few part alterations, the ballast can be produced to support 32 W lamps as well. The ballast uses GE's existing L-Comp[1] power topology in the circuit so that the integrated circuit design would be a design that could possibly be used by other CFL and EFL products with minor modifications. This gives added value by reducing cost and size of not only the BIAS, but also possibly other integral CFL and future dimmable integral and plug-in versions of the EFL products.

  5. Compact fluorescent lamp using horizontal and vertical insulating septums and convective venting geometry

    DOE Patents [OSTI]

    Siminovitch, M.

    1998-02-10

    A novel design is described for a compact fluorescent lamp, including a lamp geometry which will increase light output and efficacy of the lamp in a base down operating position by providing horizontal and vertical insulating septums positioned in the ballast compartment of the lamp to provide a cooler coldspot. Selective convective venting provides additional cooling of the ballast compartment. 9 figs.

  6. Fluorescent refrigeration

    DOE Patents [OSTI]

    Epstein, Richard I. (Santa Fe, NM); Edwards, Bradley C. (Los Alamos, NM); Buchwald, Melvin I. (Santa Fe, NM); Gosnell, Timothy R. (Santa Fe, NM)

    1995-01-01

    Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement.

  7. Fluorescent refrigeration

    DOE Patents [OSTI]

    Epstein, R.I.; Edwards, B.C.; Buchwald, M.I.; Gosnell, T.R.

    1995-09-05

    Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement. 6 figs.

  8. Potential Environmental Impacts from the Metals in Incandescent, Compact Fluorescent Lamp (CFL), and Light-Emitting Diode (LED)

    E-Print Network [OSTI]

    Short, Daniel

    Potential Environmental Impacts from the Metals in Incandescent, Compact Fluorescent Lamp (CFL, previous studies have investigated various environmental impacts from incandescent, CFL, and LED bulbs. There is uncertainty about the potential environmental impacts of these components and whether special provisions must

  9. Engineering novel fluorescent proteins

    E-Print Network [OSTI]

    Shaner, Nathan Christopher

    2006-01-01

    to Choosing Fluorescent Proteins. Nat. Methods. 2 (12): 905-Dynamics of Z-band based proteins in developing skeletaland yellow fluorescent proteins derived from Discosoma sp.

  10. A Review of the Reflector Compact Fluorescent Lights Technology Procurement Program: Conclusions and Results

    SciTech Connect (OSTI)

    Sandahl, Linda J.; Gilbride, Theresa L.; Ledbetter, Marc R.; McCullough, Jeffrey J.

    2008-05-19

    This report describes a project sponsored by the U.S. Department of Energy (DOE) and implemented by the Pacific Northwest National Laboratory (PNNL), from 2000 to 2007 to improve the performance of reflector type (R-lamp) compact fluorescent lamps (CFLs) and increase their availability throughout the United States by means of a technology development and procurement strategy. In 2000, at the request of the U.S. Department of Energy’s Emerging Technologies Program and its predecessors, the Pacific Northwest National Laboratory undertook a technology procurement seeking R-CFLs that were specifically designed for use in ICAT recessed can fixtures and that met other minimum performance criteria including minimum light output and size restrictions (to ensure they fit in standard residential recessed cans). The technology procurement included two phases. In Phase I, requests for proposals (RFPs) were issued in October 2002 and five manufacturers responded with 12 lamp models. Eight of these models met the minimum requirements and passed the 6-hour short-term test in a simulated ICAT environment. These eight models were subjected to long-term tests of 6,000 or more hours in a simulated ICAT environment. Three of these models passed the short- and long-term tests and were promoted through the program website (www.pnl.gov/rlamps), press releases, and fliers. To increase the number of qualifying models, a second RFP was issued in June 2005. In April 2007, DOE announced that 16 reflector CFL (R-CFL) models by four manufacturers had met all the minimum requirements of Phase 2 of the R-CFL Technology Innovation Competition. PNNL developed both the criteria and the test apparatus design for Elevated Temperature Life Testing (ETLT), which has been included by DOE in its draft ENERGY STAR specifications for the reflector category of CFLs. PNNL promoted the winning lamps through a program website, press releases, and fliers as well as through program partners. PNNL also helped engage distributors including Costco, the Home Depot, Bonneville Power Administration, and utility organizations.

  11. Fluorescent optical position sensor

    DOE Patents [OSTI]

    Weiss, Jonathan D.

    2005-11-15

    A fluorescent optical position sensor and method of operation. A small excitation source side-pumps a localized region of fluorescence at an unknown position along a fluorescent waveguide. As the fluorescent light travels down the waveguide, the intensity of fluorescent light decreases due to absorption. By measuring with one (or two) photodetectors the attenuated intensity of fluorescent light emitted from one (or both) ends of the waveguide, the position of the excitation source relative to the waveguide can be determined by comparing the measured light intensity to a calibrated response curve or mathematical model. Alternatively, excitation light can be pumped into an end of the waveguide, which generates an exponentially-decaying continuous source of fluorescent light along the length of the waveguide. The position of a photodetector oriented to view the side of the waveguide can be uniquely determined by measuring the intensity of the fluorescent light emitted radially at that location.

  12. Safe biodegradable fluorescent particles

    DOE Patents [OSTI]

    Martin, Sue I. (Berkeley, CA); Fergenson, David P. (Alamo, CA); Srivastava, Abneesh (Santa Clara, CA); Bogan, Michael J. (Dublin, CA); Riot, Vincent J. (Oakland, CA); Frank, Matthias (Oakland, CA)

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  13. Concentration dependence of fluorescence signal in a microfluidic fluorescence detector

    E-Print Network [OSTI]

    Klotzkin, David

    ] demonstrated a compact device using an OLED as light source and an integrated p-i-n photodiode as detector Available online 6 February 2010 Keywords: Lab-on-a-chip On-chip fluorescence Cross-polarization OLED OPD et al. [3] have recently demonstrated the use of a polyfluorene based pLED (polymer LED) as light

  14. Fluorescent Tube Lamps

    Broader source: Energy.gov [DOE]

    FEMP temporarily suspended its energy efficiency requirements for fluorescent tube lamps as it evaluates the market impact of the pending 2012 minimum efficiency standards for fluorescent lamps. The program will issue updated energy efficiency requirements when the market distribution of this product category stabilizes and when doing so has the potential to result in significant Federal energy savings.

  15. Highly thermostable fluorescent proteins

    DOE Patents [OSTI]

    Bradbury, Andrew M. (Santa Fe, NM); Waldo, Geoffrey S. (Santa Fe, NM); Kiss, Csaba (Los Alamos, NM)

    2011-03-22

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  16. Highly thermostable fluorescent proteins

    DOE Patents [OSTI]

    Bradbury, Andrew M. (Santa Fe, NM); Waldo, Geoffrey S. (Santa Fe, NM); Kiss, Csaba (Los Alamos, NM)

    2011-11-29

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  17. Highly thermostable fluorescent proteins

    DOE Patents [OSTI]

    Bradbury, Andrew M. (Santa Fe, NM); Waldo, Geoffrey S. (Santa Fe, NM); Kiss, Csaba (Los Alamos, NM)

    2012-05-01

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  18. Fluorescent filtered electrophosphorescence

    DOE Patents [OSTI]

    Forrest, Stephen R. (Princeton, NJ); Sun, Yiru (Princeton, NJ); Giebink, Noel (Princeton, NJ); Thompson, Mark E. (Anaheim Hills, CA)

    2009-01-06

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.

  19. Fluorescent filtered electrophosphorescence

    DOE Patents [OSTI]

    Forrest, Stephen (Ann Arbor, MI); Sun, Yiru (Princeton, NJ); Giebink, Noel (Ann Arbor, MI); Thompson, Mark E. (Anaheim Hills, CA)

    2010-08-03

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.

  20. Fluorescent image tracking velocimeter

    DOE Patents [OSTI]

    Shaffer, Franklin D. (Library, PA)

    1994-01-01

    A multiple-exposure fluorescent image tracking velocimeter (FITV) detects and measures the motion (trajectory, direction and velocity) of small particles close to light scattering surfaces. The small particles may follow the motion of a carrier medium such as a liquid, gas or multi-phase mixture, allowing the motion of the carrier medium to be observed, measured and recorded. The main components of the FITV include: (1) fluorescent particles; (2) a pulsed fluorescent excitation laser source; (3) an imaging camera; and (4) an image analyzer. FITV uses fluorescing particles excited by visible laser light to enhance particle image detectability near light scattering surfaces. The excitation laser light is filtered out before reaching the imaging camera allowing the fluoresced wavelengths emitted by the particles to be detected and recorded by the camera. FITV employs multiple exposures of a single camera image by pulsing the excitation laser light for producing a series of images of each particle along its trajectory. The time-lapsed image may be used to determine trajectory and velocity and the exposures may be coded to derive directional information.

  1. Replacing Fluorescent Lightbulbs | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fluorescent Lightbulbs Replacing Fluorescent Lightbulbs July 29, 2012 - 6:37pm Addthis Although fluorescent lightbulbs are generally energy efficient, you can replace them with...

  2. Fluorescent Protein Applications in Microscopy

    E-Print Network [OSTI]

    Straight, Aaron

    . The Identification of Green Fluorescent Protein III. Formation of the GFP Chromophore IV. The Structure of GFP V environment. II. The Identification of Green Fluorescent Protein The isolation of green fluorescent protein of Aequorea, Shimomura et al. noted that the lumines- cence from aequorin was blue rather than the green

  3. The Air-Fluorescence Yield

    E-Print Network [OSTI]

    F. Arqueros; F. Blanco; D. Garcia-Pinto; M. Ortiz; J. Rosado

    2008-07-30

    Detection of the air-fluorescence radiation induced by the charged particles of extensive air showers is a well-established technique for the study of ultra-high energy cosmic rays. Fluorescence telescopes provide a nearly calorimetric measure of the primary energy. Presently the main source of systematic uncertainties comes from our limited accuracy in the fluorescence yield, that is, the number of fluorescence photons emitted per unit of energy deposited in the atmosphere by the shower particles. In this paper the current status of our knowledge on the fluorescence yield both experimental an theoretical will be discussed.

  4. Magnetic fluorescent lamp

    DOE Patents [OSTI]

    Berman, S.M.; Richardson R.W.

    1983-12-29

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  5. Fluorescence analyzer for lignin

    DOE Patents [OSTI]

    Berthold, John W. (Salem, OH); Malito, Michael L. (Hubbard, OH); Jeffers, Larry (Alliance, OH)

    1993-01-01

    A method and apparatus for measuring lignin concentration in a sample of wood pulp or black liquor comprises a light emitting arrangement for emitting an excitation light through optical fiber bundles into a probe which has an undiluted sensing end facing the sample. The excitation light causes the lignin concentration to produce fluorescent emission light which is then conveyed through the probe to analyzing equipment which measures the intensity of the emission light. Measures a This invention was made with Government support under Contract Number DOE: DE-FC05-90CE40905 awarded by the Department of Energy (DOE). The Government has certain rights in this invention.

  6. Fluorescent temperature sensor

    DOE Patents [OSTI]

    Baker, Gary A [Los Alamos, NM; Baker, Sheila N [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

    2009-03-03

    The present invention is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

  7. Fluorescent Lighting | Department of Energy

    Office of Environmental Management (EM)

    - by far the most common form of fluorescent lighting but rarely found in residential buildings -- are much more energy efficient than incandescent lamps and are ideally suited...

  8. Laser-Stimulated Fluorescence in Paleontology

    E-Print Network [OSTI]

    Kaye, Thomas G.; Falk, Amanda Renee; Pittman, Michael; Sereno, Paul C.; Martin, Larry D.; Burnham, David A.; Gong, Enpu; Xu, Xing; Wang, Yinan

    2015-05-27

    Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens...

  9. Design strategies for fluorescent biodegradable polymeric biomaterials

    E-Print Network [OSTI]

    Yang, Jian

    Design strategies for fluorescent biodegradable polymeric biomaterials Yi Zhangab and Jian Yang biomaterials: biodegradable fluorescent polymers. Researchers have made significant efforts in developing versatile fluorescent biomaterials due to their promising applications in biological/biomedical labeling

  10. Nuclear Resonance Fluorescence for Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian

    2010-01-01

    clandestine material with nuclear resonance fluorescence”.E. Norman, UC Berkeley Dept. of Nuclear Engineering, privatepp. 349. G. Warren et al. “Nuclear Resonance Fluorescence of

  11. Nuclear Resonance Fluorescence for Nuclear Materials Assay

    E-Print Network [OSTI]

    Quiter, Brian Joseph

    2010-01-01

    Potential of Nuclear Resonance Fluorescence . . . . . . . .2.9.1 Nuclear ThomsonSections . . . . . . . . . . . . . . . Nuclear Resonance

  12. Integrated ultrasonic particle positioning and low excitation light fluorescence imaging

    SciTech Connect (OSTI)

    Bernassau, A. L.; Al-Rawhani, M.; Beeley, J.; Cumming, D. R. S. [School of Engineering, University of Glasgow, Glasgow, G12 8LT (United Kingdom)] [School of Engineering, University of Glasgow, Glasgow, G12 8LT (United Kingdom)

    2013-12-09

    A compact hybrid system has been developed to position and detect fluorescent micro-particles by combining a Single Photon Avalanche Diode (SPAD) imager with an acoustic manipulator. The detector comprises a SPAD array, light-emitting diode (LED), lenses, and optical filters. The acoustic device is formed of multiple transducers surrounding an octagonal cavity. By stimulating pairs of transducers simultaneously, an acoustic landscape is created causing fluorescent micro-particles to agglomerate into lines. The fluorescent pattern is excited by a low power LED and detected by the SPAD imager. Our technique combines particle manipulation and visualization in a compact, low power, portable setup.

  13. Capacitive sensing with a fluorescent lamp

    E-Print Network [OSTI]

    Cooley, John Jacob

    2007-01-01

    This work presents a modified fluorescent lamp that can be used as a capacitive sensing system. The lamp sensor measures changes in the electric fields emitted from the fluorescent bulbs in order to deduce the presence and ...

  14. Covered Product Category: Fluorescent Luminaires

    Broader source: Energy.gov [DOE]

    FEMP provides acquisition guidance and Federal efficiency requirements across a variety of product categories, including fluorescent luminaires. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

  15. Covered Product Category: Fluorescent Ballasts

    Broader source: Energy.gov [DOE]

    FEMP provides acquisition guidance and federal efficiency requirements across a variety of product categories, including fluorescent ballasts, which is a FEMP designated product category. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

  16. Chemistry & Biology Conversion of Red Fluorescent Protein

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    resonance energy transfer applications. INTRODUCTION Green fluorescent protein (GFP) from Aequoria victoria for multicolor and lifetime imaging, as well as the outstanding donor for green fluorescent proteins in Fo¨ rster green fluorescent probes, such as TagGFP or EGFP (Shaner et al., 2005). The improvement

  17. Fluorescence based chemical sensors for corrosion detection

    SciTech Connect (OSTI)

    Johnson, R.E.; Agarwala, V.S.

    1997-12-01

    Several fluorescent materials have been identified as possible corrosion sensing coatings. These are either redox or metal ion complex materials. The redox materials are nonfluorescent in the reduced state and become fluorescent upon oxidation. Incorporated into paint coatings, they provide an early warning of corrosive conditions at the metal or alloy surface. The metal ion complex materials only fluoresce when the organic compound complexes with metal ions such as those generated in corrosion reactions. Fluorescent materials have been incorporated into paint coatings and on metal surfaces for the detection of corrosion. Oxine reacts with aluminum oxide on corroded aluminum to give a fluorescence that can be photographed in UV light. Several other materials were found to have good fluorescence but cannot be reversibly oxidized or reduced at the present time. More work will be done with these compounds as well as with Schiff bases to develop new fluorescent chemical sensing materials for smart coating on alloy surfaces.

  18. Three-dimensional fluorescence lifetime tomography

    SciTech Connect (OSTI)

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J. [327 Votey Building, Department of Computer Science, University of Vermont, Burlington, Vermont 05405 (United States); 1011 Richardson Building, Photon Migration Laboratories, Texas A and M University, College Station, Texas 77843 (United States); 327 Votey Building, Department of Computer Science, University of Vermont, Burlington, Vermont 05405 (United States)

    2005-04-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores.

  19. Scanning fluorescent microthermal imaging apparatus and method

    DOE Patents [OSTI]

    Barton, Daniel L. (Albuquerque, NM); Tangyunyong, Paiboon (Albuquerque, NM)

    1998-01-01

    A scanning fluorescent microthermal imaging (FMI) apparatus and method is disclosed, useful for integrated circuit (IC) failure analysis, that uses a scanned and focused beam from a laser to excite a thin fluorescent film disposed over the surface of the IC. By collecting fluorescent radiation from the film, and performing point-by-point data collection with a single-point photodetector, a thermal map of the IC is formed to measure any localized heating associated with defects in the IC.

  20. Scanning fluorescent microthermal imaging apparatus and method

    DOE Patents [OSTI]

    Barton, D.L.; Tangyunyong, P.

    1998-01-06

    A scanning fluorescent microthermal imaging (FMI) apparatus and method is disclosed, useful for integrated circuit (IC) failure analysis, that uses a scanned and focused beam from a laser to excite a thin fluorescent film disposed over the surface of the IC. By collecting fluorescent radiation from the film, and performing point-by-point data collection with a single-point photodetector, a thermal map of the IC is formed to measure any localized heating associated with defects in the IC. 1 fig.

  1. Portable spotter for fluorescent contaminants on surfaces

    DOE Patents [OSTI]

    Schuresko, Daniel D. (Oak Ridge, TN)

    1980-01-01

    A portable fluorescence-based spotter for polynuclear aromatic hydrocarbon contamination on personnel and work area surfaces under ambient lighting conditions is provided. This instrument employs beam modulation and phase sensitive detection for discriminating between fluorescence from organic materials from reflected background light and inorganic fluorescent material. The device uses excitation and emission filters to provide differentiation between classes of aromatic organic compounds. Certain inorganic fluorescent materials, including heavy metal compounds, may also be distinguished from the organic compounds, despite both having similar optical properties.

  2. LED Replacements for Linear Fluorescent Lamps Webcast

    Broader source: Energy.gov [DOE]

    In this June 20, 2011 webcast on LED products marketed as replacements for linear fluorescent lamps, Jason Tuenge of the Pacific Northwest National Laboratory (PNNL) discussed current Lighting...

  3. Mutations that suppress the thermosensitivity of green fluorescent protein

    E-Print Network [OSTI]

    Haseloff, Jim

    Mutations that suppress the thermosensitivity of green fluorescent protein Kirby R. Siemering*, Ralph Golbik, Richard Sever* and Jim Haseloff* Background: The green fluorescent protein (GFP temperatures. Background The green fluorescent protein (GFP) from the bio- luminescent jellyfish Aequorea

  4. Fiber optical assembly for fluorescence spectrometry

    DOE Patents [OSTI]

    Carpenter, II, Robert W. (Pagosa Springs, CO); Rubenstein, Richard (Staten Island, NY); Piltch, Martin (Los Alamos, NM); Gray, Perry (Los Alamos, NM)

    2010-12-07

    A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

  5. Applications of Nuclear Resonance Fluorescence

    SciTech Connect (OSTI)

    Warren, Glen A.; Detwiler, Rebecca S.; Peplowski, Patrick N.

    2010-11-11

    Nuclear Resonance Fluorescence (NRF) has the potential of addressing a wide variety of applications, which require isotopic and/or elemental information about a sample. We have investigated a variety of non-proliferation applications that may be addressed by NRF. From these applications, we have selected two, measuring uranium enrichment in UF6 cylinders and material verification in dismantlement, to investigate in more detail. Analytical models have been developed to evaluate these applications, and test measurements have been conducted to validate those models. We found that it is unlikely with current technology to address the requirements for UF6 cylinder enrichment measurements. In contrast, NRF is a very promising approach for material verification for dismantlement.

  6. Using Nuclear Resonance Fluorescence for Nondestructive Isotopic Analysis

    E-Print Network [OSTI]

    Ludewigt, Bernhard A.

    2010-01-01

    7, (1959) pp. 54. [12] B.J. Quiter, ``Nuclear ResonanceFluorescence for Nuclear Materials Assay,'' University ofclandestine material with nuclear resonance fluorescence,"

  7. End-to-end absolute energy calibration of atmospheric fluorescence telescopes by an electron linear accelerator

    E-Print Network [OSTI]

    End-to-end absolute energy calibration of atmospheric fluorescence telescopes by an electron linear of fluorescence telescopes by using air showers induced by electron beams from a linear accelerator, which and constructing a compact linear accelerator with a maximum electron energy of 40 MeV and an intensity of 6.4 m

  8. Glucose sensing molecules having selected fluorescent properties

    DOE Patents [OSTI]

    Satcher, Jr., Joe H.; Lane, Stephen M.; Darrow, Christopher B.; Cary, Douglas R.; Tran, Joe Anh

    2004-01-27

    An analyte sensing fluorescent molecule that employs intramolecular electron transfer is designed to exhibit selected fluorescent properties in the presence of analytes such as saccharides. The selected fluorescent properties include excitation wavelength, emission wavelength, fluorescence lifetime, quantum yield, photostability, solubility, and temperature or pH sensitivity. The compound comprises an aryl or a substituted phenyl boronic acid that acts as a substrate recognition component, a fluorescence switch component, and a fluorophore. The fluorophore and switch component are selected such that the value of the free energy for electron transfer is less than about 3.0 kcal mol.sup.-1. Fluorescent compounds are described that are excited at wavelengths greater than 400 nm and emit at wavelengths greater than 450 nm, which is advantageous for optical transmission through skin. The fluorophore is typically selected from transition metal-ligand complexes and thiazine, oxazine, oxazone, or oxazine-one as well as anthracene compounds. The fluorescent compound can be immobilized in a glucose permeable biocompatible polymer matrix that is implantable below the skin.

  9. Doppler-free intermodulated fluorescence spectroscopy of $^4He$ $2^3P-3^{1,3}D$ transitions at 588 nm with a one-watt compact laser system

    E-Print Network [OSTI]

    Luo, Pei-Ling; Feng, Yan; Wang, Li-Bang; Shy, Jow-Tsong

    2015-01-01

    We have demonstrated Doppler-free intermodulated fluorescence spectroscopy of helium $2^3P-3^{1,3}D$ transitions in an rf discharged sealed-off cell using a compact laser system at 588 nm. An external cavity diode laser at 1176 nm was constructed to seed a Raman fiber amplifier. Laser power of more than one watt at 588 nm was produced by frequency doubling of the fiber amplifier output using a MgO:PPLN crystal. A doubling efficiency of 23 % was achieved. The power-dependent spectra of the $2^3P-3^3D$ transitions were investigated. Furthermore, the Doppler-free spectrum of the spin-forbidden $2^3P-3^1D$ transitions was observed for the first time. Our results are crucial towards precision test of QED atomic calculations, especially for improving the determination of the helium $3^1D-3^3D$ separation.

  10. Multiplexed fluorescence detector system for capillary electrophoresis

    DOE Patents [OSTI]

    Yeung, E.S.; Taylor, J.A.

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figs.

  11. Multiplexed fluorescence detector system for capillary electrophoresis

    DOE Patents [OSTI]

    Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)

    1996-03-12

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  12. Multiplexed fluorescence detector system for capillary electrophoresis

    DOE Patents [OSTI]

    Yeung, Edward S. (Ames, IA); Taylor, John A. (Nevada, IA)

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

  13. Multiplexed fluorescence detector system for capillary electrophoresis

    DOE Patents [OSTI]

    Yeung, E.S.; Taylor, J.A.

    1994-06-28

    A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis. 14 figures.

  14. Fluorescent Lamp Ballasts | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12, 2015ExecutiveFluorescent Lamp Ballasts Fluorescent Lamp Ballasts The

  15. Laser excited confocal microscope fluorescence scanner and method

    DOE Patents [OSTI]

    Mathies, R.A.; Peck, K.

    1992-02-25

    A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

  16. Air fluorescence relevant for cosmic-ray detection--Summary of the 5th fluorescence workshop, El Escorial 2007

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    Air fluorescence relevant for cosmic-ray detection--Summary of the 5th fluorescence workshop, El August 2008 Keywords: Fluorescence yield Air showers a b s t r a c t High-energy cosmic rays with energies exceeding 1017 eV are frequently observed by measurements of the fluorescence light induced by air

  17. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOE Patents [OSTI]

    Miller, S.M.

    1983-10-31

    Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

  18. Ultrabright fluorescent OLEDS using triplet sinks

    DOE Patents [OSTI]

    Zhang, Yifan; Forrest, Stephen R; Thompson, Mark

    2013-06-04

    A first device is provided. The first device further comprises an organic light emitting device. The organic light emitting device further comprises an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further comprises an organic host compound, an organic emitting compound capable of fluorescent emission at room temperature, and an organic dopant compound. The triplet energy of the dopant compound is lower than the triplet energy of the host compound. The dopant compound does not strongly absorb the fluorescent emission of the emitting compound.

  19. Deep tissue fluorescence imaging and in vivo biological applications

    E-Print Network [OSTI]

    2012-01-01

    17(11) Crosignani et al. : Deep tissue fluorescence imaging16. D. Kobat et al. , “Deep tissue multiphoton microscopyV. Crosignani et al. , “ In vivo deep tissue fluorescence

  20. Imaging chromophores with undetectable fluorescence by stimulated emission microscopy

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    LETTERS Imaging chromophores with undetectable fluorescence by stimulated emission microscopy Wei, that is, spontaneous emission, is generally more sensitive than absorption measurement, and is widely used undetectable fluorescence because the spontaneous emission is dominated by theirfastnon-radiative decay3

  1. Probing the denatured state ensemble with fluorescence 

    E-Print Network [OSTI]

    Alston, Roy Willis

    2004-09-30

    of these five proteins were studied and compared to the fluorescent properties of eight model compounds: N-acetyl-tryptophan-amide (NATA), N-acetyl-Ala-Trp-Ala-amide (AWA), N-acetyl-Ala-Ala-Trp-Ala-Ala-amide (AAWAA), and five pentapeptides based on the sequence...

  2. Chlorophyll Fluorescence Monitoring at Selected LTER

    E-Print Network [OSTI]

    Boyce, Richard L.

    no energy can go to photosynthesis · Thermal dissipation processes are usually minimal in the dark · So most of plant stress on photosynthesis in the field Fate of Light absorbed by Chlorophyll · Energy channeled to reaction center of PSII, used for photosynthesis ­ P · Thermal dissipation ­ D · Fluorescent emission ­ F

  3. Chemistry & Biology Red Fluorescent Protein with Reversibly

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    to the photoswitchable absor- bance, rsTagRFP can be used as an acceptor for a photochromic Fo¨ rster resonance energy-OFF photoswitching of the rsTagRFP acceptor. INTRODUCTION Green fluorescent protein (GFP) from Aequorea victoriaTFP0.7 (Henderson et al., 2007), green Dronpa (Ando et al., 2004) and its derivatives (Ando et al

  4. Atomic and Molecular Fluorescence Excited by Photodissociation

    E-Print Network [OSTI]

    electron impact processes are compared with photodissociation. A bibliography of photo dissociation the strength a n d shape of fluorescence lines that arise from excited fragments produced in molecular photo more critical. T h e D o p p l e r width of the emission is important, however, since a larger width

  5. DNA sequencing using fluorescence background electroblotting membrane

    DOE Patents [OSTI]

    Caldwell, K.D.; Chu, T.J.; Pitt, W.G.

    1992-05-12

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings

  6. Imaging properties of supercritical angle fluorescence optics

    E-Print Network [OSTI]

    Enderlein, Jörg

    Imaging properties of supercritical angle fluorescence optics J¨org Enderlein,1,4, Ingo Gregor,1.ruckstuhl@pci.uzh.ch 4http://www.joerg-enderlein.de enderlein@physik3.gwdg.de Abstract: In recent years, new optical the detection volume within one wavelength to an interface. For conventional optical systems with high numerical

  7. Bayesian fluorescence in situ hybridisation signal classification

    E-Print Network [OSTI]

    Lerner, Boaz

    hybridisation (FISH) signals for the detection of genetic abnormalities. Based on well-discriminating features hybridisation (FISH); Gaussian mixture model; Naive Bayesian classifier; Signal classification Artificial.artmed.2003.11.005 #12;1. Introduction Fluorescence in situ hybridisation (FISH) allows selective staining

  8. Oil Classification with Fluorescence Spectroscopy Engineering Physics

    E-Print Network [OSTI]

    Oldenburg, Carl von Ossietzky Universität

    detected by these channels. The investigation used three methods to examine crude oil, heavy oil, sludge1 Oil Classification with Fluorescence Spectroscopy Engineering Physics Master of Engineering and classification of oil spills on water surfaces. It is an overview of the laser remote sensor technique

  9. Purchasing Energy-Efficient Suspended Fluorescent Luminaires

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for suspended fluorescent luminaires, a product category covered by FEMP efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

  10. Optimization and Applications of Fluorescence anisotropy assays and Fluorescence Resonance Energy Transfer Measurements

    E-Print Network [OSTI]

    Liyanage, Mangala Roshan

    2009-01-01

    Calmodulin (CaM) is a calcium signaling protein that activates over hundred of targets including PMCA. This dissertation mainly focuses on optimizing and applications of fluorescence anisotropy (FA) and FRET experiments for CaM-target interactions...

  11. Apparatus for eliminating background interference in fluorescence measurements

    DOE Patents [OSTI]

    Martin, J.C.; Jett, J.H.

    1986-03-04

    The disclosure is directed to an apparatus for eliminating background interference during fluorescence measurements in a multiple laser flow cytometer. A biological particle stained with fluorescent dyes is excited by a laser. A fluorescence detector detects the fluorescence. The particle scatters light and a gate signal is generated and delayed until the biological particle reaches the next laser. The delayed signal turns on this next laser, which excites a different stained component of the same biological particle. 8 figs.

  12. Text-Alternative Version: LED Replacements for Linear Fluorescent Lamps

    Broader source: Energy.gov [DOE]

    Below is the text-alternative version of the "LED Replacements for Linear Fluorescent Lamps" webcast, held June 20, 2011.

  13. Size-dependent fluorescence of bioaerosols: Mathematical model using fluorescing and absorbing molecules in bacteria

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hill, Steven C.; Williamson, Chatt C.; Doughty, David C.; Pan, Yong-Le; Santarpia, Joshua L.; Hill, Hanna H.

    2015-02-02

    This paper uses a mathematical model of fluorescent biological particles composed of bacteria and/or proteins (mostly as in Hill et al., 2013 [23]) to investigate the size-dependence of the total fluorescence emitted in all directions. The model applies to particles which have negligible reabsorption of fluorescence within the particle. The specific particles modeled here are composed of ovalbumin and of a generic Bacillus. The particles need not be spherical, and in some cases need not be homogeneous. However, the results calculated in this paper are for spherical homogeneous particles. Light absorbing and fluorescing molecules included in the model are aminomore »acids, nucleic acids, and several coenzymes. Here the excitation wavelength is 266 nm. The emission range, 300 to 370 nm, encompasses the fluorescence of tryptophan. The fluorescence cross section (CF) is calculated and compared with one set of published measured values. We investigate power law (Ady) approximations to CF, where d is diameter, and A and y are parameters adjusted to fit the data, and examine how y varies with d and composition, including the fraction as water. The particle's fluorescence efficiency (QF=CF/geometric-cross-section) can be written for homogeneous particles as QabsRF, where Qabs is the absorption efficiency, and RF, the fraction of the absorbed light emitted as fluorescence, is independent of size and shape. When QF is plotted vs. mid or mi(mr-1)d, where m=mr+imi is the complex refractive index, the plots for different fractions of water in the particle tend to overlap.« less

  14. Size-dependent fluorescence of bioaerosols: Mathematical model using fluorescing and absorbing molecules in bacteria

    SciTech Connect (OSTI)

    Hill, Steven C.; Williamson, Chatt C.; Doughty, David C.; Pan, Yong-Le; Santarpia, Joshua L.; Hill, Hanna H.

    2015-02-02

    This paper uses a mathematical model of fluorescent biological particles composed of bacteria and/or proteins (mostly as in Hill et al., 2013 [23]) to investigate the size-dependence of the total fluorescence emitted in all directions. The model applies to particles which have negligible reabsorption of fluorescence within the particle. The specific particles modeled here are composed of ovalbumin and of a generic Bacillus. The particles need not be spherical, and in some cases need not be homogeneous. However, the results calculated in this paper are for spherical homogeneous particles. Light absorbing and fluorescing molecules included in the model are amino acids, nucleic acids, and several coenzymes. Here the excitation wavelength is 266 nm. The emission range, 300 to 370 nm, encompasses the fluorescence of tryptophan. The fluorescence cross section (CF) is calculated and compared with one set of published measured values. We investigate power law (Ady) approximations to CF, where d is diameter, and A and y are parameters adjusted to fit the data, and examine how y varies with d and composition, including the fraction as water. The particle's fluorescence efficiency (QF=CF/geometric-cross-section) can be written for homogeneous particles as QabsRF, where Qabs is the absorption efficiency, and RF, the fraction of the absorbed light emitted as fluorescence, is independent of size and shape. When QF is plotted vs. mid or mi(mr-1)d, where m=mr+imi is the complex refractive index, the plots for different fractions of water in the particle tend to overlap.

  15. Imaging green fluorescent protein in transgenic plants. Jim Haseloff

    E-Print Network [OSTI]

    Haseloff, Jim

    light, and an accessory green fluorescent protein (GFP), which accepts energy from aequorin and reImaging green fluorescent protein in transgenic plants. Jim Haseloff MRC Laboratory of Molecular of seedlings. The green fluorescent protein (GFP) from the cnidarian jellyfish Aequorea victoria shares none

  16. 10081 How snakes slither 10086 Biodegradable fluorescent polymers

    E-Print Network [OSTI]

    Yang, Jian

    10081 How snakes slither 10086 Biodegradable fluorescent polymers 10097 Studying forces within, and Michael J. Shelley (see pages 10081­10085) CHEMISTRY Biodegradable fluorescent polymers Although fluorescent polymers that can be crosslinked into membranes. The polymers may serve as scaffolds in tissue

  17. Invisible-fluorescent identification tags for materials

    SciTech Connect (OSTI)

    Lewis, Linda A.; Allgood, Glenn O.; Smithwick, III, Robert W.

    2013-03-26

    A taggant composition including a taggant material that is invisible in light of the visible spectrum and fluoresces under a non-visible excitation energy, a binder, and a solvent in which the taggant material and the binder are dissolved. The taggant composition can be printed or otherwise applied to a material such as fabric to provide a detectable and identifiable indicium. A method and apparatus for detecting and decoding the taggant indicium are also provided.

  18. Fluorescence Rise Time Measurements for High Temperature Fluorescence-Based Thermometry

    SciTech Connect (OSTI)

    Allison, S.W.

    2005-03-24

    Certain ceramic-like phosphor materials exhibit bright fluorescence with a pronounced temperature dependence over a range which spans the cryogenic to 1700 C, depending on the specific phosphor. To measure temperature, a surface, for instance a turbine blade, is coated with the material. An optical system, sometimes including optical fibers, conveys stimulating light and collects the emission for analysis. Either emission intensity or decay time may indicate temperature. Previously fielded tests have involved surfaces such as blades, vanes, pistons, in-take valves, sheets of galvanneal steel, etc. The fluorescent coatings may be applied to small parts via sputtering methods or to large areas by mixture with inorganic binders. Presented here are results characterizing fluorescence rise times as a means of determining temperature from ambient to 700 C for Y{sub 2}O{sub 3}:Eu.

  19. Solid state laser media driven by remote nuclear powered fluorescence

    DOE Patents [OSTI]

    Prelas, Mark A. (Columbia, MO)

    1992-01-01

    An apparatus is provided for driving a solid state laser by a nuclear powered fluorescence source which is located remote from the fluorescence source. A nuclear reaction produced in a reaction chamber generates fluorescence or photons. The photons are collected from the chamber into a waveguide, such as a fiber optic waveguide. The waveguide transports the photons to the remote laser for exciting the laser.

  20. Fluorescent dyes for probing cellular functions associated with...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fluorescence dyes suitable for visualization of specific cellular functions associated with electron beam damage and carry out electron microscopy imaging of labelled cells....

  1. Time-resolved fluorescence decay measurements for flowing particles

    DOE Patents [OSTI]

    Deka, C.; Steinkamp, J.A.

    1999-06-01

    Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.

  2. Fluorescent protein marker lines in maize: generation and applications

    E-Print Network [OSTI]

    Jackson, David

    : fluorescent protein, FRET, maize, pOp, LhG4 Introduction Maize, one of the most important crops worldwide, has

  3. Fluorescent Pigments for High-Performance Cool Roofing and Facades...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    to develop a new class of dark-colored pigments for cool metal roof and faade coatings that incorporate near-infrared fluorescence and reflectance to improve energy...

  4. Organimetallic Fluorescent Complex Polymers For Light Emitting Applications

    DOE Patents [OSTI]

    Shi, Song Q. (Phoenix, AZ); So, Franky (Tempe, AZ)

    1997-10-28

    A fluorescent complex polymer with fluorescent organometallic complexes connected by organic chain spacers is utilized in the fabrication of light emitting devices on a substantially transparent planar substrate by depositing a first conductive layer having p-type conductivity on the planar surface of the substrate, depositing a layer of a hole transporting and electron blocking material on the first conductive layer, depositing a layer of the fluorescent complex polymer on the layer of hole transporting and electron blocking material as an electron transporting emissive layer and depositing a second conductive layer having n-type conductivity on the layer of fluorescent complex polymer.

  5. Quantitative planar laser-induced fluorescence imaging of multi...

    Office of Scientific and Technical Information (OSTI)

    Article: Quantitative planar laser-induced fluorescence imaging of multi-component fuelair mixing in a firing gasoline-direct-injection engine: Effects of residual exhaust...

  6. Guide to Red Fluorescent Proteins and Biosensors for Flow Cytometry

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    CHAPTER 17 Guide to Red Fluorescent Proteins and Biosensors for Flow Cytometry Kiryl D. Piatkevich. Simultaneous Detection of Multiple FPs V. Fluorescent Timers VI. FRET-Based Genetically Encoded Biosensors A. Conventional FRET Pairs B. Novel Advanced FRET Pairs C. FRET Biosensors in Multicolor Flow Cytometry D

  7. REVIEW ARTICLE Planar laser induced fluorescence in aqueous flows

    E-Print Network [OSTI]

    Crimaldi, John P.

    REVIEW ARTICLE Planar laser induced fluorescence in aqueous flows J. P. Crimaldi Received: 14 for measuring scalar concentra- tions in fluid flows. A fluorescent dye is used as a scalar proxy, and local Osbourne Reynolds performed his famous experiments on laminar and turbulent flow in round pipes (Reynolds

  8. Fluorescence Probe Studies of Gelatin-Sodium Dodecyl Sulfate Interactions

    E-Print Network [OSTI]

    Bales, Barney

    Fluorescence Probe Studies of Gelatin-Sodium Dodecyl Sulfate Interactions P. C. Griffiths* and J. A dodecyl sulfate (SDS) micelles bound to gelatin have been studied by fluorescence using 8-anilino-1-naphththalene sulfonic acid (ANS) as probe. Like gelatin, ANS binds in the region of the micelle occupied

  9. Teal fluorescent proteins: Characterization of a reversibly photoswitchable variant

    E-Print Network [OSTI]

    Campbell, Robert E.

    . Cyan FPs (CFPs), widely used in multicolor imaging or as a fluorescence resonance energy transfer (FRET green fluorescent protein (GFP) in 1961 when he was isolating aequorin, a calcium cell imaging due to drawbacks such as dual excitation peaks and poor folding efficiency. Fortunately

  10. Improved ``Optical Highlighter'' Probes Derived from Discosoma Red Fluorescent Protein

    E-Print Network [OSTI]

    Marchant, Jonathan

    , Minneapolis, Minnesota ABSTRACT The tetrameric red fluorescent protein, DsRed, undergoes a rapid red to green-emitting species of DsRed and an enhancement of emission from the ``immature'' green species, likely caused by dequenching of fluorescence resonance energy transfer occurring within the protein tetramer. Here, we have

  11. Radioiodine detector based on laser induced fluorescence

    DOE Patents [OSTI]

    McDonald, Jimmie R. (Upper Marlboro, MD); Baronavski, Andrew P. (Alexandria, VA)

    1980-01-01

    The invention involves the measurement of the concentration of the radioisotope .sup.129 I.sub.2 in the presence of a gas. The invention uses a laser to excite a sample of the .sup.129 I.sub.2 in a sample gas chamber and a reference sample of a known concentration of .sup.129 I.sub.2 in a reference gas chamber. The .sup.129 I.sub.2 in the sample and reference gas chamber each gives off fluorescence emissions which are received by photomultipliers which provide signals to a detector. The detector uses a ratioing technique to determine the concentration of .sup.129 I.sub.2 in the sample gas chamber.

  12. Interdomain Fluorescence Resonance Energy Transfer in SERCA Probed by Cyan-Fluorescent Protein Fused to the Actuator Domain

    E-Print Network [OSTI]

    Thomas, David D.

    ), the measured FRET efficiency between CFP (donor in A domain) and FITC (acceptor in N domain) was 0.34 ( 0Interdomain Fluorescence Resonance Energy Transfer in SERCA Probed by Cyan-Fluorescent Protein transport by the sarcoendoplasmic reticulum Ca-ATPase (SERCA) from rabbit fast- twitch skeletal muscle. X

  13. Air Fluorescence Relevant for Cosmic-Ray Detection - Summary of the 5th Fluorescence Workshop, El Escorial 2007

    E-Print Network [OSTI]

    Fernando Arqueros; Joerg R. Hoerandel; Bianca Keilhauer

    2008-07-24

    High-energy cosmic rays with energies exceeding $10^{17}$ eV are frequently observed by measurements of the fluorescence light induced by air showers. A major contribution to the systematic uncertainties of the absolute energy scale of such experiments is the insufficient knowledge of the fluorescence light yield of electrons in air. The aim of the 5th Fluorescence Workshop was to bring together experimental and theoretical expertise to discuss the latest progress on the investigations of the fluorescence light yield. The results of the workshop will be reviewed as well as the present status of knowledge in this field. Emphasis is given to the fluorescence light yield important for air shower observations and its dependence on atmospheric parameters, like pressure, temperature, and humidity. The effects of the latest results on the light observed from air showers will be discussed.

  14. Improved fluorescence-enhanced optical imaging and tomography by enhanced excitation light rejection 

    E-Print Network [OSTI]

    Hwang, Kil Dong

    2009-05-15

    Fluorescence enhanced optical imaging and tomography studies involve the detection of weak fluorescent signals emanating from nano- to picomolar concentrations of exogenous or endogenously produced fluorophore concurrent ...

  15. Fluorescent lamp unit with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, M.W.; George, W.A.

    1989-08-08

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

  16. Sustainable LED Fluorescent Light Replacement Technology

    SciTech Connect (OSTI)

    2011-06-30

    Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: • Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life. • Environmental Impact Review – Designs are comparable across lifecycle phases, subsystems, and environmental impact category, and can be normalized to a userdefined functional unit. • Drill-down Review – These provide an indepth look at individual lamp designs with the ability to review across subsystem or lifecycle phase.

  17. Large core polymer optical backplanes for fluorescence detection

    E-Print Network [OSTI]

    Lee, Kevin Shao-Kwan

    2006-01-01

    Fluorescence based sensors are used for determining environmental parameters such as dissolved oxygen or pH in biological systems without disturbing a biological system's equilibrium. Recently, there has been a drive to ...

  18. THE HISTORY AND TECHNICAL EVOLUTION OF HIGH FREQUENCY FLUORESCENT LIGHTING

    E-Print Network [OSTI]

    Campbell, John H.

    2011-01-01

    Dec. 1953. "Hi-Volt-Cycle Lighting ~ Launched i n a Hi-Wide2, F e b r u a r y , 19 53. "Lighting Your Plant with Highg h Frequency Fluorescent Lighting John H. Campbell December

  19. Enlightening Medicago truncatula transformation and shading GFP fluorescence 

    E-Print Network [OSTI]

    Zhou, Xin

    2005-11-01

    cotyledons of most transgenic M. truncatula lines, silencing of the GUS expression from the phas promoter was observed in several lines, indicating the occurrence of novel epigenetic events. The diminution of GFP fluorescence in transgenic M. truncatula...

  20. Protein subcellular localization assays using split fluorescent proteins

    DOE Patents [OSTI]

    Waldo, Geoffrey S. (Santa Fe, NM); Cabantous, Stephanie (Los Alamos, NM)

    2009-09-08

    The invention provides protein subcellular localization assays using split fluorescent protein systems. The assays are conducted in living cells, do not require fixation and washing steps inherent in existing immunostaining and related techniques, and permit rapid, non-invasive, direct visualization of protein localization in living cells. The split fluorescent protein systems used in the practice of the invention generally comprise two or more self-complementing fragments of a fluorescent protein, such as GFP, wherein one or more of the fragments correspond to one or more beta-strand microdomains and are used to "tag" proteins of interest, and a complementary "assay" fragment of the fluorescent protein. Either or both of the fragments may be functionalized with a subcellular targeting sequence enabling it to be expressed in or directed to a particular subcellular compartment (i.e., the nucleus).

  1. Phase-sensitive fluorescent imaging with coherent reconstruction

    E-Print Network [OSTI]

    Field, Jeffrey J; Bartels, Randy A

    2015-01-01

    Optical imaging plays a critical role in advancing our understanding of three dimensional dynamics of biological systems. Coherent imaging (CI) methods exploit spatial phase information, encoded through propagation of coherent signal light emerging from a specimen, to extract a three-dimensional representation of the object from a single high-speed measurement. Until now, CI methods could not be applied to incoherent light, severely limiting their ability to image the most powerful biological probes available - fluorescent molecules - with sufficient speed and volume to observe important processes, such as neural processing in live specimens. We introduce a new imaging technique that transfers the spatial propagation phase of coherent illumination light to incoherent fluorescent light emission. The transfer of propagation phase allows CI techniques to be applied to fluorescent light imaging, and leads to large increases in imaging speed and depth of field. With this advance, biological imaging of fluorescent ...

  2. Dynamic fluorescence imaging with molecular agents for cancer detection 

    E-Print Network [OSTI]

    Kwon, Sun Kuk

    2009-05-15

    -wavelength fluorescence imaging was accomplished using a liquid crystal tunable filter (LCTF). Excitation light was used for reflectance images with a LCTF transmitting a shorter wavelength than the peak in the excitation light spectrum. Therefore, images can...

  3. Exploring the mechanome with optical tweezers and single molecule fluorescence

    E-Print Network [OSTI]

    Brau, Ricardo R. (Ricardo Rafael), 1979-

    2008-01-01

    The combination of optical tweezers and single molecule fluorescence into an instrument capable of making combined, coincident measurements adds an observable dimension that allows for the examination of the localized ...

  4. Calibration of fluorescence resonance energy transfer in microscopy

    DOE Patents [OSTI]

    Youvan, Dougalas C.; Silva, Christopher M.; Bylina, Edward J.; Coleman, William J.; Dilworth, Michael R.; Yang, Mary M.

    2003-12-09

    Imaging hardware, software, calibrants, and methods are provided to visualize and quantitate the amount of Fluorescence Resonance Energy Transfer (FRET) occurring between donor and acceptor molecules in epifluorescence microscopy. The MicroFRET system compensates for overlap among donor, acceptor, and FRET spectra using well characterized fluorescent beads as standards in conjunction with radiometrically calibrated image processing techniques. The MicroFRET system also provides precisely machined epifluorescence cubes to maintain proper image registration as the sample is illuminated at the donor and acceptor excitation wavelengths. Algorithms are described that pseudocolor the image to display pixels exhibiting radiometrically-corrected fluorescence emission from the donor (blue), the acceptor (green) and FRET (red). The method is demonstrated on samples exhibiting FRET between genetically engineered derivatives of the Green Fluorescent Protein (GFP) bound to the surface of Ni chelating beads by histidine-tags.

  5. Calibration of fluorescence resonance energy transfer in microscopy

    DOE Patents [OSTI]

    Youvan, Douglas C. (San Jose, CA); Silva, Christopher M. (Sunnyvale, CA); Bylina, Edward J. (San Jose, CA); Coleman, William J. (Moutain View, CA); Dilworth, Michael R. (Santa Cruz, CA); Yang, Mary M. (San Jose, CA)

    2002-09-24

    Imaging hardware, software, calibrants, and methods are provided to visualize and quantitate the amount of Fluorescence Resonance Energy Transfer (FRET) occurring between donor and acceptor molecules in epifluorescence microscopy. The MicroFRET system compensates for overlap among donor, acceptor, and FRET spectra using well characterized fluorescent beads as standards in conjunction with radiometrically calibrated image processing techniques. The MicroFRET system also provides precisely machined epifluorescence cubes to maintain proper image registration as the sample is illuminated at the donor and acceptor excitation wavelengths. Algorithms are described that pseudocolor the image to display pixels exhibiting radiometrically-corrected fluorescence emission from the donor (blue), the acceptor (green) and FRET (red). The method is demonstrated on samples exhibiting FRET between genetically engineered derivatives of the Green Fluorescent Protein (GFP) bound to the surface of Ni chelating beads by histidine-tags.

  6. SHORT COMMUNICATION The Chlorophyll Fluorescence Ratio F735/F700

    E-Print Network [OSTI]

    Gitelson, Anatoly

    sylvatica L.), elm (Ulmus minor 1988; Dahn et al., 1992). In green leaves, about 90% of Miller), and wild of reabsorption of the Chl fluorescence was quan- titatively estimated (Dahn et al., 1992; Gunther et al

  7. FY08 Annual Report for Nuclear Resonance Fluorescence Imaging

    SciTech Connect (OSTI)

    Warren, Glen A.; Caggiano, Joseph A.

    2009-01-06

    FY08 annual report for project the "Nuclear Resonance Fluorescence Imaging" project. Reviews accomplishments of last 3 years, including U-235 signature search, comparison of different photon sources, and examination of NRF measurements using monochromatic photon source.

  8. Narrowband fluorescent nanodiamonds produced from chemical vapor deposition films

    E-Print Network [OSTI]

    Neu, Elke; Gross, Elke; Hepp, Christian; Steinmetz, David; Zscherpel, Elisabeth; Ghodbane, Slimane; Sternschulte, Hadwig; Steinmueller-Nethl, Doris; Liang, Yuejiang; Krueger, Anke; Becher, Christoph

    2011-01-01

    We report on the production of nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition (CVD) film. The NDs display high crystalline quality as well as intense narrowband (7 nm) room temperature luminescence at 738 nm due to in situ incorporated silicon vacancy (SiV) centers. The fluorescence properties at room and cryogenic temperatures indicate that the NDs are, depending on preparation, applicable as single photon sources or as fluorescence labels.

  9. Narrowband fluorescent nanodiamonds produced from chemical vapor deposition films

    E-Print Network [OSTI]

    Elke Neu; Carsten Arend; Felix Guldner; Elke Gross; Christian Hepp; David Steinmetz; Elisabeth Zscherpel; Slimane Ghodbane; Hadwig Sternschulte; Doris Steinmueller-Nethl; Yuejiang Liang; Anke Krueger; Christoph Becher

    2011-05-24

    We report on the production of nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition (CVD) film. The NDs display high crystalline quality as well as intense narrowband (7 nm) room temperature luminescence at 738 nm due to in situ incorporated silicon vacancy (SiV) centers. The fluorescence properties at room and cryogenic temperatures indicate that the NDs are, depending on preparation, applicable as single photon sources or as fluorescence labels.

  10. Fluorescent Labeling Reagents Optimized for Capillary Electrophoretic Separations 

    E-Print Network [OSTI]

    Estrada, Roy Tonacao, III

    2012-02-14

    molecules fluoresce, background noise from the separation matrix and other extraneous compounds is usually a problem. Moreover, UV lasers tend to be more expensive than those used in the visible region [8]. To go around the background noise problem..., excitation can be done in the visible or higher wavelengths. However, only a very small number of proteins have native fluorescence above the UV region. To effectively use LIF as a detection method, proteins have to be labeled with fluorophores that can...

  11. Method and apparatus for detection of fluorescently labeled materials

    DOE Patents [OSTI]

    Stern, David (Mt. View, CA); Fiekowsky, Peter (Los Altos, CA)

    1997-01-01

    Fluorescently marked targets bind to a substrate 230 synthesized with polymer sequences at known locations. The targets are detected by exposing selected regions of the substrate 230 to light from a light source 100 and detecting the photons from the light fluoresced therefrom, and repeating the steps of exposure and detection until the substrate 230 is completely examined. The resulting data can be used to determine binding affinity of the targets to specific polymer sequences.

  12. Method and apparatus for detection of fluorescently labeled materials

    DOE Patents [OSTI]

    Stern, David; Fiekowsky, Peter

    2004-05-25

    Fluorescently marked targets bind to a substrate 230 synthesized with polymer sequences at known locations. The targets are detected by exposing selected regions of the substrate 230 to light from a light source 100 and detecting the photons from the light fluoresced therefrom, and repeating the steps of exposure and detection until the substrate 230 is completely examined. The resulting data can be used to determine binding affinity of the targets to specific polymer sequences.

  13. Measurement of Flow Velocity and Inference of Liquid Viscosity in a Microfluidic Channel by Fluorescence Photobleaching

    E-Print Network [OSTI]

    and determine their contributions to fluorescence recovery in an infused liquid medium.12 The fundamental

  14. LucY: A versatile new fluorescent reporter protein

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Auldridge, Michele E.; Cao, Hongnan; Sen, Saurabh; Franz, Laura P.; Bingman, Craig A.; Yennamalli, Ragothaman M.; Phillips, Jr., George N.; Mead, David; Steinmetz, Eric J.; Michnick, Stephen W.

    2015-04-23

    We report on the discovery, isolation, and use of a novel yellow fluorescent protein. Lucigen Yellow (LucY) binds one FAD molecule within its core, thus shielding it from water and maintaining its structure so that fluorescence is 10-fold higher than freely soluble FAD. LucY displays excitation and emission spectra characteristic of FAD, with 3 excitation peaks at 276nm, 377nm, and 460nm and a single emission peak at 530nm. These excitation and emission maxima provide the large Stokes shift beneficial to fluorescence experimentation. LucY belongs to the MurB family of UDP-N-acetylenolpyruvylglucosamine reductases. The high resolution crystal structure shows that in contrastmore »to other structurally resolved MurB enzymes, LucY does not contain a potentially quenching aromatic residue near the FAD isoalloxazine ring, which may explain its increased fluorescence over related proteins. Using E. coli as a system in which to develop LucY as a reporter, we show that it is amenable to circular permutation and use as a reporter of protein-protein interaction. Fragmentation between its distinct domains renders LucY non-fluorescent, but fluorescence can be partially restored by fusion of the fragments to interacting protein domains. Thus, LucY may find application in Protein-fragment Complementation Assays for evaluating protein-protein interactions.« less

  15. Rigidifying Fluorescent Linkers by Metal-Organic Framework Formation for Fluorescence Blue Shift and Quantum Yield Enhancement

    SciTech Connect (OSTI)

    Wei, ZW; Gu, ZY; Arvapally, RK; Chen, YP; McDougald, RN; Ivy, JF; Yakovenko, AA; Feng, DW; Omary, MA; Zhou, HC

    2014-06-11

    We demonstrate that rigidifying the structure of fluorescent linkers by structurally constraining them in metal-organic frameworks (MOFs) to control their conformation effectively tunes the fluorescence energy and enhances the quantum yield. Thus, a new tetraphenylethylene-based zirconium MOF exhibits a deep-blue fluorescent emission at 470 nm with a unity quantum yield (99.9 +/- 0.5%) under Ar, representing ca. 3600 cm(-1) blue shift and doubled radiative decay efficiency vs the linker precursor. An anomalous increase in the fluorescence lifetime and relative intensity takes place upon heating the solid MOF from cryogenic to ambient temperatures. The origin of these unusual photoluminescence properties is attributed to twisted linker conformation, intramolecular hindrance, and framework rigidity.

  16. Rigidifying Fluorescent Linkers by Metal–Organic Framework Formation for Fluorescence Blue Shift and Quantum Yield Enhancement

    SciTech Connect (OSTI)

    Wei, Zhangwen; Gu, Zhi-Yuan; Arvapally, Ravi K.; Chen, Ying-Pin; Ivy, Joshua F.; Yakovenko, Andrey A.; Feng, Dawei; Omary, Mohammad A.; Zhou, Hong-Cai

    2014-06-11

    We demonstrate that rigidifying the structure of fluorescent linkers by structurally constraining them in metal–organic frameworks (MOFs) to control their conformation effectively tunes the fluorescence energy and enhances the quantum yield. Thus, a new tetraphenylethylene-based zirconium MOF exhibits a deep-blue fluorescent emission at 470 nm with a unity quantum yield (99.9 ± 0.5%) under Ar, representing ca. 3600 cm?¹ blue shift and doubled radiative decay efficiency vs the linker precursor. An anomalous increase in the fluorescence lifetime and relative intensity takes place upon heating the solid MOF from cryogenic to ambient temperatures. The origin of these unusual photoluminescence properties is attributed to twisted linker conformation, intramolecular hindrance, and framework rigidity.

  17. Cyanine-based probe\\tag-peptide pair fluorescence protein imaging and fluorescence protein imaging methods

    SciTech Connect (OSTI)

    Mayer-Cumblidge, M. Uljana; Cao, Haishi

    2013-01-15

    A molecular probe comprises two arsenic atoms and at least one cyanine based moiety. A method of producing a molecular probe includes providing a molecule having a first formula, treating the molecule with HgOAc, and subsequently transmetallizing with AsCl.sub.3. The As is liganded to ethanedithiol to produce a probe having a second formula. A method of labeling a peptide includes providing a peptide comprising a tag sequence and contacting the peptide with a biarsenical molecular probe. A complex is formed comprising the tag sequence and the molecular probe. A method of studying a peptide includes providing a mixture containing a peptide comprising a peptide tag sequence, adding a biarsenical probe to the mixture, and monitoring the fluorescence of the mixture.

  18. Three-dimensional x-ray fluorescence mapping of a gold nanoparticle-loaded phantom

    SciTech Connect (OSTI)

    Ren, Liqiang; Wu, Di; Li, Yuhua; Liu, Hong, E-mail: liu@ou.edu [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)] [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Wang, Ge [Biomedical Imaging Cluster and Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Biomedical Imaging Cluster and Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Wu, Xizeng [Department of Radiology, University of Alabama, Birmingham, Alabama 35233 (United States)] [Department of Radiology, University of Alabama, Birmingham, Alabama 35233 (United States)

    2014-03-15

    Purpose : X-ray fluorescence (XRF) is a promising technique with sufficient specificity and sensitivity for identifying and quantifying features in small samples containing high atomic number (Z) materials such as iodine, gadolinium, and gold. In this study, the feasibility of applying XRF to early breast cancer diagnosis and treatment is studied using a novel approach for three-dimensional (3D) x-ray fluorescence mapping (XFM) of gold nanoparticle (GNP)-loaded objects in a physical phantom at the technical level. Methods : All the theoretical analysis and experiments are conducted under the condition of using x-ray pencil beam and a compactly integrated x-ray spectrometer. The penetrability of the fluorescence x-rays from GNPs is first investigated by adopting a combination of BR12 with 70 mm/50 mm in thickness on the excitation/emission path to mimic the possible position of tumor goldin vivo. Then, a physical phantom made of BR12 is designed to translate in 3D space with three precise linear stages and subsequently the step by step XFM scanning is performed. The experimental technique named as background subtraction is applied to isolate the gold fluorescence from each spectrum obtained by the spectrometer. Afterwards, the attenuations of both the incident primary x-ray beam with energies beyond the gold K-edge energy (80.725 keV) and the isolated gold K{sub ?} fluorescence x-rays (65.99 –69.80 keV) acquired after background subtraction are well calibrated, and finally the unattenuated K{sub ?} fluorescence counts are used to realize mapping reconstruction and to describe the linear relationship between gold fluorescence counts and corresponding concentration of gold solutions. Results : The penetration results show that the goldK{sub ?} fluorescence x-rays have sufficient penetrability for this phantom study, and the reconstructed mapping results indicate that both the spatial distribution and relative concentration of GNPs within the designed BR12 phantom can be well identified and quantified. Conclusions : Although the XFM method in this investigation is still studied at the technical level and is not yet practical for routinein vivo mapping tasks with GNPs, the current penetrability measurements and phantom study strongly suggest the feasibility to establish and develop a 3D XFM system.

  19. Fluorescent single walled nanotube/silica composite materials

    DOE Patents [OSTI]

    Dattelbaum, Andrew M.; Gupta, Gautam; Duque, Juan G.; Doorn, Stephen K.; Hamilton, Christopher E.; DeFriend Obrey, Kimberly A.

    2013-03-12

    Fluorescent composites of surfactant-wrapped single-walled carbon nanotubes (SWNTs) were prepared by exposing suspensions of surfactant-wrapped carbon nanotubes to tetramethylorthosilicate (TMOS) vapor. Sodium deoxycholate (DOC) and sodium dodecylsulphate (SDS) were the surfactants. No loss in emission intensity was observed when the suspension of DOC-wrapped SWNTs were exposed to the TMOS vapors, but about a 50% decrease in the emission signal was observed from the SDS-wrapped SWNTs nanotubes. The decrease in emission was minimal by buffering the SDS/SWNT suspension prior to forming the composite. Fluorescent xerogels were prepared by adding glycerol to the SWNT suspensions prior to TMOS vapor exposure, followed by drying the gels. Fluorescent aerogels were prepared by replacing water in the gels with methanol and then exposing them to supercritical fluid drying conditions. The aerogels can be used for gas sensing.

  20. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOE Patents [OSTI]

    Vo-Dinh, T.; Panjehpour, M.; Overholt, B.F.

    1996-12-03

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample. 5 figs.

  1. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOE Patents [OSTI]

    Vo-Dinh, Tuan (Knoxville, TN); Panjehpour, Masoud (Knoxville, TN); Overholt, Bergein F. (Knoxville, TN)

    1996-01-01

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample.

  2. Engineering and Characterization of a Superfolder Green Fluorescent Protein

    SciTech Connect (OSTI)

    Pedelacq,J.; Cabantous, S.; Tran, T.; Terwilliger, T.; Waldo, G.

    2006-01-01

    Existing variants of green fluorescent protein (GFP) often misfold when expressed as fusions with other proteins. We have generated a robustly folded version of GFP, called 'superfolder' GFP, that folds well even when fused to poorly folded polypeptides. Compared to 'folding reporter' GFP, a folding-enhanced GFP containing the 'cycle-3' mutations and the 'enhanced GFP' mutations F64L and S65T, superfolder GFP shows improved tolerance of circular permutation, greater resistance to chemical denaturants and improved folding kinetics. The fluorescence of Escherichia coli cells expressing each of eighteen proteins from Pyrobaculum aerophilum as fusions with superfolder GFP was proportional to total protein expression. In contrast, fluorescence of folding reporter GFP fusion proteins was strongly correlated with the productive folding yield of the passenger protein. X-ray crystallographic structural analyses helped explain the enhanced folding of superfolder GFP relative to folding reporter GFP.

  3. Nuclear Resonance Fluorescence for Safeguards Applications

    SciTech Connect (OSTI)

    Ludewigt, Bernhard A; Quiter, Brian J; Ambers, Scott D

    2011-02-04

    In nuclear resonance fluorescence (NRF) measurements, resonances are excited by an external photon beam leading to the emission of {gamma} rays with specific energies that are characteristic of the emitting isotope. The promise of NRF as a non-destructive analysis technique (NDA) in safeguards applications lies in its potential to directly quantify a specific isotope in an assay target without the need for unfolding the combined responses of several fissile isotopes as often required by other NDA methods. The use of NRF for detection of sensitive nuclear materials and other contraband has been researched in the past. In the safeguards applications considered here one has to go beyond mere detection and precisely quantify the isotopic content, a challenge that is discussed throughout this report. Basic NRF measurement methods, instrumentation, and the analytical calculation of NRF signal strengths are described in Section 2. Well understood modeling and simulation tools are needed for assessing the potential of NRF for safeguards and for designing measurement systems. All our simulations were performed with the radiation transport code MCNPX, a code that is widely used in the safeguards community. Our initial studies showed that MCNPX grossly underestimated the elastically scattered background at backwards angles due to an incorrect treatment of Rayleigh scattering. While new, corrected calculations based on ENDF form factors showed much better agreement with experimental data for the elastic scattering of photons on an uranium target, the elastic backscatter is still not rigorously treated. Photonuclear scattering processes (nuclear Thomson, Delbruck and Giant Dipole Resonance scattering), which are expected to play an important role at higher energies, are not yet included. These missing elastic scattering contributions were studied and their importance evaluated evaluated against data found in the literature as discussed in Section 3. A transmission experiment was performed in September 2009 to test and demonstrate the applicability of the method to the quantitative measurement of an isotope of interest embedded in a thick target. The experiment, data analysis, and results are described in Section 4. The broad goal of our NRF studies is to assess the potential of the technique in safeguards applications. Three examples are analyzed in Section 5: the isotopic assay of spent nuclear fuel (SNF), the measurement of {sup 235}U enrichment in UF{sub 6} cylinders, and the determination of {sup 239}Pu in mixed oxide (MOX) fuel. The study of NRF for the assay of SNF assemblies was supported by the Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy as part of a large multi-lab/university effort to quantify the plutonium (Pu) mass in spent nuclear fuel assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. NRF is one of 14 NDA techniques being researched. The methodology for performing and analyzing quantitative NRF measurements was developed for determining Pu mass in SNF and is extensively discussed in this report. The same methodology was applied to the assessment of NRF for the measurement of {sup 235}U enrichment and the determination of {sup 239}Pu in MOX fuel. The analysis centers on determining suitable NRF measurement methods, measurement capabilities that could be realized with currently available instrumentation, and photon source and detector requirements for achieving useful NDA capabilities.

  4. Heat transfer assembly for a fluorescent lamp and fixture

    DOE Patents [OSTI]

    Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

    1992-12-29

    In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

  5. Heat transfer assembly for a fluorescent lamp and fixture

    DOE Patents [OSTI]

    Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)

    1992-01-01

    In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.

  6. Design and evaluation of a device for fast multispectral time-resolved fluorescence spectroscopy and imaging

    SciTech Connect (OSTI)

    Yankelevich, Diego R.; Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California 95616 ; Ma, Dinglong; Liu, Jing; Sun, Yang; Sun, Yinghua; Bec, Julien; Marcu, Laura; Elson, Daniel S.

    2014-03-15

    The application of time-resolved fluorescence spectroscopy (TRFS) to in vivo tissue diagnosis requires a method for fast acquisition of fluorescence decay profiles in multiple spectral bands. This study focusses on development of a clinically compatible fiber-optic based multispectral TRFS (ms-TRFS) system together with validation of its accuracy and precision for fluorescence lifetime measurements. It also presents the expansion of this technique into an imaging spectroscopy method. A tandem array of dichroic beamsplitters and filters was used to record TRFS decay profiles at four distinct spectral bands where biological tissue typically presents fluorescence emission maxima, namely, 390, 452, 542, and 629 nm. Each emission channel was temporally separated by using transmission delays through 200 ?m diameter multimode optical fibers of 1, 10, 19, and 28 m lengths. A Laguerre-expansion deconvolution algorithm was used to compensate for modal dispersion inherent to large diameter optical fibers and the finite bandwidth of detectors and digitizers. The system was found to be highly efficient and fast requiring a few nano-Joule of laser pulse energy and <1 ms per point measurement, respectively, for the detection of tissue autofluorescent components. Organic and biological chromophores with lifetimes that spanned a 0.8–7 ns range were used for system validation, and the measured lifetimes from the organic fluorophores deviated by less than 10% from values reported in the literature. Multi-spectral lifetime images of organic dye solutions contained in glass capillary tubes were recorded by raster scanning the single fiber probe in a 2D plane to validate the system as an imaging tool. The lifetime measurement variability was measured indicating that the system provides reproducible results with a standard deviation smaller than 50 ps. The ms-TRFS is a compact apparatus that makes possible the fast, accurate, and precise multispectral time-resolved fluorescence lifetime measurements of low quantum efficiency sub-nanosecond fluorophores.

  7. Extending the utility of enzymes for site-specific targeting of fluorescent probes

    E-Print Network [OSTI]

    Liu, Daniel S. (Daniel Shao-Chen)

    2014-01-01

    Genetically encodable fluorescence reporters such as the green fluorescent protein (GFP) are useful for studying protein expression, localization, and dynamics in a variety of biological systems. GFP and its related variants, ...

  8. Detection of Ethylene Gas by Fluorescence Turn-On of a Conjugated Polymer

    E-Print Network [OSTI]

    Swager, Timothy Manning

    Ripe fruits: The fluorescence of a conjugated polymer is quenched by the presence of copper(I) moieties. Upon exposure to ethylene gas the copper complexes bind to ethylene and no longer quench the polymer fluorescence ...

  9. Cancer diagnostics using dynamic near-infrared optical imaging and fluorescent contrast agents 

    E-Print Network [OSTI]

    Gurfinkel, Mikhail

    2006-04-12

    A new optical imaging modality has been developed for small animal in vivo imaging of near-infrared fluorescence resulting from fluorescent contrast agents specifically targeted to molecular markers of cancer. The imaging ...

  10. Understanding Zinc Quantification with Existing and Advanced Ditopic Fluorescent Zinpyr Sensors

    E-Print Network [OSTI]

    Buccella, Daniela

    Treatment of aqueous zinc solutions with incremental additions of a ditopic fluorescent sensor of the Zinpyr family, based on pyridine/pyrazine-containing metal recognition units, affords a fluorescence titration curve ...

  11. Fluorescent Amino Acids: Modular Building Blocks for the Assembly of New Tools for Chemical Biology

    E-Print Network [OSTI]

    Krueger, Andrew T.

    Fluorescence spectroscopy is a powerful tool for probing complex biological processes. The ubiquity of peptide–protein and protein–protein interactions in these processes has made them important targets for fluorescence ...

  12. Microwave-Assisted Synthesis of Fluorescent Carbon Nanoparticles 

    E-Print Network [OSTI]

    Chen, Bonnie

    2014-08-19

    , such as buckminsterfullerene (C60)[5], carbon nanotubes (CNTs)[5], and nanodiamonds[5]. Their special chemical and physical properties point to a high potential in applications in industry and medicine. 1.3.2 Fluorescent carbon nano-particles discovered by accident...

  13. Identication of Major Water-Soluble Fluorescent Components of Some

    E-Print Network [OSTI]

    Myrick, Michael Lenn

    Polyaromatic hydrocarbons (PAHs) and other dissolved hydrocarbons are ubiquitous contaminants of seawater the pattern of ¯uorescent contaminants in water to be used as ®ngerprints of speci®c types of contaminationIdenti®cation of Major Water-Soluble Fluorescent Components of Some Petrochemicals M. GRONER, A. R

  14. Multicolor Fluorescent Biosensor for Multiplexed Detection of DNA Rong Hu,,,

    E-Print Network [OSTI]

    Tan, Weihong

    Engineering, College of Biology, Collaborative Innovation Center of Molecular Engineering for Theranostics 50-fold lower than that of traditional unamplified homogeneous fluorescent assay methods differences in drug metabo- lism.4,5 On the basis of their simplicity, low-cost, high sensitivity, rapid

  15. Fluorescence of silicon nanoparticles prepared by nanosecond pulsed laser

    SciTech Connect (OSTI)

    Liu, Chunyang, E-mail: chunyangliu@126.com; Sui, Xin; Yang, Fang; Ma, Wei; Li, Jishun; Xue, Yujun [Henan University of Science and Technology, Luoyang, 471003 (China)] [Henan University of Science and Technology, Luoyang, 471003 (China); Fu, Xing [Tianjin University, Tianjin, 300072 (China)] [Tianjin University, Tianjin, 300072 (China)

    2014-03-15

    A pulsed laser fabrication method is used to prepare fluorescent microstructures on silicon substrates in this paper. A 355 nm nanosecond pulsed laser micromachining system was designed, and the performance was verified and optimized. Fluorescence microscopy was used to analyze the photoluminescence of the microstructures which were formed using the pulsed laser processing technique. Photoluminescence spectra of the microstructure reveal a peak emission around 500 nm, from 370 nm laser irradiation. The light intensity also shows an exponential decay with irradiation time, which is similar to attenuation processes seen in porous silicon. The surface morphology and chemical composition of the microstructure in the fabricated region was also analyzed with multifunction scanning electron microscopy. Spherical particles are produced with diameters around 100 nm. The structure is compared with porous silicon. It is likely that these nanoparticles act as luminescence recombination centers on the silicon surface. The small diameter of the particles modifies the band gap of silicon by quantum confinement effects. Electron-hole pairs recombine and the fluorescence emission shifts into the visible range. The chemical elements of the processed region are also changed during the interaction between laser and silicon. Oxidation and carbonization play an important role in the enhancement of fluorescence emission.

  16. Optical gating of perylene bisimide fluorescence using dithienylcyclopentene photochromic switches

    SciTech Connect (OSTI)

    Pärs, Martti; Köhler, Jürgen, E-mail: juergen.koehler@uni-bayreuth.de [Experimental Physics IV, University of Bayreuth, 95440 Bayreuth (Germany)] [Experimental Physics IV, University of Bayreuth, 95440 Bayreuth (Germany); Gräf, Katja; Bauer, Peter; Thelakkat, Mukundan [Applied Functional Polymers, University of Bayreuth, 95440 Bayreuth (Germany)] [Applied Functional Polymers, University of Bayreuth, 95440 Bayreuth (Germany)

    2013-11-25

    The emission of millions of fluorescence photons from a chromophore is controlled by the absorption of a few tens of photons in a photochromic molecule. The parameters that determine the efficiency of this process are investigated, providing insights for the development of an all-optical gate.

  17. Plane-wave fluorescence tomography with adaptive finite elements

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    Plane-wave fluorescence tomography with adaptive finite elements Amit Joshi Photon Migration reflectance imaging setup. The method employs planar illumination with modulated light and frequency domain fluo- rescence measurements made on the illumination plane. An adaptive finite-element algorithm

  18. Enhanced Archaerhodopsin Fluorescent Protein Voltage Yiyang Gong1,2*

    E-Print Network [OSTI]

    Ferrari, Silvia

    Enhanced Archaerhodopsin Fluorescent Protein Voltage Indicators Yiyang Gong1,2* , Jin Zhong Li1 by nearly three-fold in comparison to Arch-D95N. Citation: Gong Y, Li JZ, Schnitzer MJ (2013) Enhanced; Published June 19, 2013 Copyright: © 2013 Gong et al. This is an open-access article distributed under

  19. Experiment 4 Operation and Limitations of a Fluorescence Spectrometer

    E-Print Network [OSTI]

    Nazarenko, Alexander

    quinine concentration. Background: The principles of molecular fluorescence are covered in your text In this experiment, you will determine the exact amount of quinine in various liquids (tonic water and colas). The approximate concentration is 100 ppm. Preparation of solutions: 1.00 mM quinine in 0.05 M sulfuric acid

  20. EMERGING TECHNOLOGIES Two-photon excitation chlorophyll fluorescence lifetime imaging

    E-Print Network [OSTI]

    Qu, Jianan

    at higher Cd concentration was clearly identified. The decay of chlorophyll fluorescence extracted from) toxicity Abbreviations Cd Cadmium PS Photosystem LHCII Light-harvesting complex II PAM Pulse and Computer Engineering, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon

  1. Fluorescent lamp with static magnetic field generating means

    DOE Patents [OSTI]

    Moskowitz, Philip E. (Peabody, MA); Maya, Jakob (Brookline, MA)

    1987-01-01

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed.

  2. Fluorescent lamp with static magnetic field generating means

    DOE Patents [OSTI]

    Moskowitz, P.E.; Maya, J.

    1987-09-08

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed. 2 figs.

  3. Amplifying Fluorescent Polymers Direct Synthesis of an OligonucleotidePoly-

    E-Print Network [OSTI]

    Tan, Weihong

    Amplifying Fluorescent Polymers Direct Synthesis of an Oligonucleotide­Poly- (phenylene ethynylene bioprobes can be constructed with these polymers for selective target recog- nition. To achieve this objective, the polymer must be conjugated with a biomolecule such as a DNA strand, a peptide, or a protein

  4. Automated hybridization/imaging device for fluorescent multiplex DNA sequencing

    DOE Patents [OSTI]

    Weiss, Robert B. (Salt Lake City, UT); Kimball, Alvin W. (Salt Lake City, UT); Gesteland, Raymond F. (Salt Lake City, UT); Ferguson, F. Mark (Salt Lake City, UT); Dunn, Diane M. (West Valley City, UT); Di Sera, Leonard J. (Salt Lake City, UT); Cherry, Joshua L. (Salt Lake City, UT)

    1995-01-01

    A method is disclosed for automated multiplex sequencing of DNA with an integrated automated imaging hybridization chamber system. This system comprises an hybridization chamber device for mounting a membrane containing size-fractionated multiplex sequencing reaction products, apparatus for fluid delivery to the chamber device, imaging apparatus for light delivery to the membrane and image recording of fluorescence emanating from the membrane while in the chamber device, and programmable controller apparatus for controlling operation of the system. The multiplex reaction products are hybridized with a probe, then an enzyme (such as alkaline phosphatase) is bound to a binding moiety on the probe, and a fluorogenic substrate (such as a benzothiazole derivative) is introduced into the chamber device by the fluid delivery apparatus. The enzyme converts the fluorogenic substrate into a fluorescent product which, when illuminated in the chamber device with a beam of light from the imaging apparatus, excites fluorescence of the fluorescent product to produce a pattern of hybridization. The pattern of hybridization is imaged by a CCD camera component of the imaging apparatus to obtain a series of digital signals. These signals are converted by the controller apparatus into a string of nucleotides corresponding to the nucleotide sequence an automated sequence reader. The method and apparatus are also applicable to other membrane-based applications such as colony and plaque hybridization and Southern, Northern, and Western blots.

  5. Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy

    E-Print Network [OSTI]

    Rosen, Joseph

    Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy Gary, Israel 4 rosen@ee.bgu.ac.il *gbrooker@jhu.edu Abstract: Fresnel Incoherent Correlation Holography (FINCH. Rosen and G. Brooker, "Digital spatially incoherent Fresnel holography," Opt. Lett. 32(8), 912­914 (2007

  6. Purchasing Energy-Efficient Ceiling-Mounted Fluorescent Luminaires

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance for ceiling-mounted fluorescent luminaires, a product category covered by FEMP efficiency requirements. Federal laws and requirements mandate that agencies purchase ENERGY STAR-qualified or FEMP-designated products in all product categories covered by these programs and in any acquisition actions that are not specifically exempted by law.

  7. Fluorescence photon migration by the boundary element method

    SciTech Connect (OSTI)

    Fedele, Francesco; Eppstein, Margaret J. . E-mail: maggie.eppstein@uvm.edu; Laible, Jeffrey P.; Godavarty, Anuradha; Sevick-Muraca, Eva M.

    2005-11-20

    The use of the boundary element method (BEM) is explored as an alternative to the finite element method (FEM) solution methodology for the elliptic equations used to model the generation and transport of fluorescent light in highly scattering media, without the need for an internal volume mesh. The method is appropriate for domains where it is reasonable to assume the fluorescent properties are regionally homogeneous, such as when using highly specific molecularly targeted fluorescent contrast agents in biological tissues. In comparison to analytical results on a homogeneous sphere, BEM predictions of complex emission fluence are shown to be more accurate and stable than those of the FEM. Emission fluence predictions made with the BEM using a 708-node mesh, with roughly double the inter-node spacing of boundary nodes as in a 6956-node FEM mesh, match experimental frequency-domain fluorescence emission measurements acquired on a 1087 cm{sup 3} breast-mimicking phantom at least as well as those of the FEM, but require only 1/8 to 1/2 the computation time.

  8. Throwing a wrench in the translational machinery : discovery of RNA ligands by fluorescence techniques

    E-Print Network [OSTI]

    Parsons, Jerod Russell

    2010-01-01

    1493 position had UV absorption measurements made at everyHX-HX5, Fluorescence measurements, UV melting experiments,

  9. Steady-state directional diffuse reflectance and fluorescence of human skin

    E-Print Network [OSTI]

    Pilon, Laurent

    .3660, 170.7050, 290.7050, 300.2530. 1. Introduction Fluorescence is the physical phenomenon in which light

  10. SO2 fluorescence from vacuum ultraviolet dissociative excitation of SO3

    SciTech Connect (OSTI)

    Suto, M.; Ye, C.; Ram, R.S.; Lee, L.C.

    1987-06-04

    The absorption and fluorescence excitation spectra of SO3 were measured in the 145-160-nm region with synchrotron radiation as a light source. The fluorescence spectra produced by excitation of SO3 at 147 and 157 nm were dispersed and compared with the laser-induced fluorescence spectrum of SO2, from which the emitter is identified to be the excited SO2*. The photodissociation process of SO3 is discussed in accord with the fluorescence observed.

  11. 428 BIOCHIMICAET BIOPHYSICAACTA pH CONTROL OF THE CHLOROPHYLL a FLUORESCENCE IN ALGAE

    E-Print Network [OSTI]

    Govindjee

    428 BIOCHIMICAET BIOPHYSICAACTA BBA 46126 pH CONTROL OF THE CHLOROPHYLL a FLUORESCENCE IN ALGAE on the "slow" (min) time course of Chlorophyll a fluorescence yield in the green alga Chlorella pyrenoidosa and in the blue-green alga Anacystis nidulans. In Chlorella, the decay of fluorescence yield, in the I- to 5-rain

  12. Air fluorescence relevant for cosmic-ray detection--Review of pioneering measurements

    E-Print Network [OSTI]

    Hörandel, Jörg R.

    Air fluorescence relevant for cosmic-ray detection--Review of pioneering measurements Fernando Keywords: Fluorescence yield Air showers a b s t r a c t Cosmic rays with energies exceeding 1017 eV are frequently registered by measurements of the fluorescence light emitted by extensive air showers. The main

  13. Caged Molecular Fluorescence Velocimetry to measure meso-to micro-scale thermal flow fields 

    E-Print Network [OSTI]

    Park, Jaesung

    2000-01-01

    (CPL). The system utilizes a microscope objective lens, caged molecular fluorescence probes, Nd:YAG laser for UV light source, Ar-ion laser for 488 nm fluorescence pumping, and a color CCD camera to record a series of fluorescent images. Caged...

  14. Exploration of New Chromophore Structures Leads to the Identification of Improved Blue Fluorescent Proteins

    E-Print Network [OSTI]

    Campbell, Robert E.

    Proteins Hui-wang Ai, Nathan C. Shaner,§,| Zihao Cheng, Roger Y. Tsien,§ and Robert E. Campbell*, Uni: The variant of Aequorea green fluorescent protein (GFP) known as blue fluorescent protein (BFP) was originally improved versions of BFP along with a variety of engineered fluorescent protein variants with novel

  15. Development of rapid microbial methods for lysine quantification in feed ingredients based on green fluorescent protein fluorescence 

    E-Print Network [OSTI]

    Chalova-Zhekova, Vesela I.

    2007-04-25

    ) was inserted in the genome of E. coli lysine auxotroph as a part of a mini-Tn5- transposon by conjugation. Bacterial growth response to external lysine and small peptides was monitored and recorded by measuring the fluorescence emitted by GFP. The second type...

  16. HIgh Rate X-ray Fluorescence Detector

    SciTech Connect (OSTI)

    Grudberg, Peter Matthew [XIA LLC

    2013-04-30

    The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the need for liquid nitrogen. In addition, by integrating the processing electronics inside the detector housing, the detector performance will be much less affected by the typically noisy electrical environment of a synchrotron hutch, and will also be much more compact than current systems, which can include a detector involving a large LN2 dewar and multiple racks of electronics. The combined detector/processor system is designed to match or exceed the performance and features of currently available detector systems, at a lower cost and with more ease of use due to the small size of the detector. In addition, the detector system is designed to be modular, so a small system might just have one detector module, while a larger system can have many â?? you can start with one detector module, and add more as needs grow and budget allows. The modular nature also serves to simplify repair. In large part, we were successful in achieving our goals. We did develop a very high performance, large area multi-channel SDD detector, packaged with all associated electronics, which is easy to use and requires minimal external support (a simple power supply module and a closed-loop water cooling system). However, we did fall short of some of our stated goals. We had intended to base the detector on modular, large-area detectors from Ketek GmbH in Munich, Germany; however, these were not available in a suitable time frame for this project, so we worked instead with pnDetector GmbH (also located in Munich). They were able to provide a front-end detector module with six 100 m^2 SDD detectors (two monolithic arrays of three elements each) along with associated preamplifiers; these detectors surpassed the performance we expected to get from the Ketek detectors, however they are housed in a sealed module, which does not offer the ease of repair and expandability weâ??d hoped to achieve with the Ketek SDDâ??s. Our packaging efforts were quite successful, as we came up with a very compact way to mount the detector and to house the associated electronics, as well as a very effective way to reliably take out the heat (from the electronics as well as the detectorâ??s Peltier coolers) without risk of condensation and without external airflow or vibration, which could create problems for the target applications. While we were able to design compact processing electronics that fit into the detector assembly, they are still at the prototype stage, and would require a significant redesign to achieve product status. We have not yet tested this detector at a synchrotron facility; we do still plan on working with some close contacts at the nearby Stanford Synchrotron Radiation Laboratory (SSRL) to get some testing with the beam (using existing commercial electronics for readout, as the integrated processor is not ready for use).

  17. The use of fluorescent compounds and complexes of metals as early warning detectors for corrosion

    SciTech Connect (OSTI)

    Johnson, R.E.; Agarwala, V.S.

    1994-12-31

    Several compounds have been identified which change their fluorescent behavior upon oxidation or reduction. These compounds have been investigated to determine the effects of temperature, pH, reduction conditions and re-oxidation behavior on their fluorescence. They have been incorporated into primer paint coatings for aluminum alloys and were found to fluoresce if the coating was scratched and exposed to air and moisture. Another compound was found to fluoresce with aluminum ions and its fluorescence behavior with varying conditions was also investigated. This compound, if added to a primer coating on an aluminum alloy, should fluoresce when aluminum ions begin to form as the alloy corrodes. Both of these methods appear to have potential to be early warning sensors for corrosion. Large surface areas of alloy material, such as are used in aircraft, could be scanned with UV light to detect the fluorescence of these materials indicating possible corrosion sites.

  18. Archaeometrical studies using X-ray fluorescence methods

    SciTech Connect (OSTI)

    Pauna, Catalina; Constantinescu, B.; Constantin, F.; Bugoi, R.; Stan, D.; Vasilescu, A. [National Institute of Nuclear Physics and Engineering, POB MG-6, 077125, Bucharest (Romania)

    2010-04-26

    Elemental analysis contributes to authentication (knowing the elemental composition and considering the information about the usual composition of the objects in different historical periods it can be established if the item is original or fake), provenance studies (minor and trace elements indicates ores origin and 'consequently' mines location), (relative) dating of archaeological objects (e.g. for painted items--the chemical recipes for pigments can offer information about the age of objects). The paper gives a general layout for the NIPNE Archaeometry Laboratory's applications using X-Ray Fluorescence (XRF), micro--Proton Induced X-Ray Emission (micro-PIXE), micro-Synchrotron Radiation Induced X-Ray Fluorescence (micro--SR-XRF) methods.

  19. Rotational order–disorder structure of fluorescent protein FP480

    SciTech Connect (OSTI)

    Pletnev, Sergei, E-mail: svp@ncifcrf.gov [SAIC-Frederick Inc., Basic Research Program, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Morozova, Kateryna S.; Verkhusha, Vladislav V. [Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Dauter, Zbigniew, E-mail: svp@ncifcrf.gov [Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); SAIC-Frederick Inc., Basic Research Program, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2009-09-01

    An analysis of the rotational order–disorder structure of fluorescent protein FP480 is presented. In the last decade, advances in instrumentation and software development have made crystallography a powerful tool in structural biology. Using this method, structural information can now be acquired from pathological crystals that would have been abandoned in earlier times. In this paper, the order–disorder (OD) structure of fluorescent protein FP480 is discussed. The structure is composed of tetramers with 222 symmetry incorporated into the lattice in two different ways, namely rotated 90° with respect to each other around the crystal c axis, with tetramer axes coincident with crystallographic twofold axes. The random distribution of alternatively oriented tetramers in the crystal creates a rotational OD structure with statistically averaged I422 symmetry, although the presence of very weak and diffuse additional reflections suggests that the randomness is only approximate.

  20. Fluorescence quenching of CdSe quantum dots on graphene

    SciTech Connect (OSTI)

    Guo, Xi Tao; Hua Ni, Zhen, E-mail: zhni@seu.edu.cn; Yan Nan, Hai; Hui Wang, Wen [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China)] [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China); Yan Liao, Chun [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China)] [Physics Department, National Photoelectric Technology and Functional Materials and Application of Science and Technology International Cooperation Base, Northwest University, Xi'an 710069 (China); Zhang, Yan; Wei Zhao, Wei [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)] [Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211189 (China)

    2013-11-11

    We studied systematically the fluorescence quenching of CdSe quantum dots (QDs) on graphene and its multilayers, as well as graphene oxide (GO) and reduced graphene oxide (rGO). Raman intensity of QDs was used as a quantitatively measurement of its concentration in order to achieve a reliable quenching factor (QF). It was found that the QF of graphene (?13.1) and its multilayers is much larger than rGO (?4.4), while GO (?1.5) has the lowest quenching efficiency, which suggests that the graphitic structure is an important factor for quenching the fluorescence of QDs. It was also revealed that the QF of graphene is not strongly dependent on its thicknesses.

  1. Blue fluorescent organic light emitting diodes with multilayered graphene anode

    SciTech Connect (OSTI)

    Hwang, Joohyun [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Hong Kyw [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Moon, Jaehyun; Shin, Jin-Wook; Joo, Chul Woong; Han, Jun-Han; Cho, Doo-Hee; Huh, Jin Woo [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Sung-Yool [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Lee, Jeong-Ik, E-mail: jiklee@etri.re.kr [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Chu, Hye Yong [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)

    2012-10-15

    As an innovative anode for organic light emitting devices (OLEDs), we have investigated graphene films. Graphene has importance due to its huge potential in flexible OLED applications. In this work, graphene films have been catalytically grown and transferred to the glass substrate for OLED fabrications. We have successfully fabricated 2 mm × 2 mm device area blue fluorescent OLEDs with graphene anodes which showed 2.1% of external quantum efficiency at 1000 cd/m{sup 2}. This is the highest value reported among fluorescent OLEDs using graphene anodes. Oxygen plasma treatment on graphene has been found to improve hole injections in low voltage regime, which has been interpreted as oxygen plasma induced work function modification. However, plasma treatment also increases the sheet resistance of graphene, limiting the maximum luminance. In summary, our works demonstrate the practical possibility of graphene as an anode material for OLEDs and suggest a processing route which can be applied to various graphene related devices.

  2. X-Ray Fluorescence (XRF) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEtGeorgia:Illinois:Wizard PowerWyandanch, New1991) | Open EnergyFluorescence

  3. Analysis and design of an electronic ballast for fluorescent tube 

    E-Print Network [OSTI]

    Kuchimanchi, Krishna V.

    1992-01-01

    Chair of Advisory Committee: Dr. Enjeti Prasad In this thesis, the analysis, design and implementation of an electronic ballast circuit with power factor correction to replace the conventional ballast for fluorescent lighting systems is presented... layout for the PCB Voltage across the tube Current through the tube 44 45 25 Gate voltages across the mosfets 27 Conventional diode rectifier Rectifier with inductor 47 48 28 Series resonant filter 49 29 Parallel resonant power factor...

  4. Contraband Detection with Nuclear Resonance Fluorescence: Feasibility and Impact

    SciTech Connect (OSTI)

    Pruet, J; Lange, D

    2007-01-03

    In this report they show that cargo interrogation systems developed to thwart trafficking of illicit nuclear materials could also be powerful tools in the larger fight against contraband smuggling. In particular, in addition to detecting special nuclear materials, cargo scanning systems that exploit nuclear resonance fluorescence to detect specific isotopes can be used to help find: chemical weapons; some drugs as well as some chemicals regulated under the controlled substances act; precious metals; materials regulated under export control laws; and commonly trafficked fluorocarbons.

  5. Fluorescent spectra of chromatographic fractions of crude oils 

    E-Print Network [OSTI]

    Dixon, William Samuel

    1952-01-01

    of Results, ~ ~ ~ ~ ~ ~ i ~ ~ ~ ~ 25 XI. Bibliography. ~ . "" o" . . ". .. . . . ~ 26 XII. Appendix PURPOSE This invest1gation ?as undertaken in an effort to develop a means of the chromatographic separation of a crude oil~ and to examine... these fractions by spectro;ra hic means to determines (l) v'hether there are differences in the fluorescent spectra of the various chromatographic fractions oi a given crude oil, and (2) whether there are differ- ences between similar chromatographic fractions...

  6. Enhanced detection of fluorescence quenching in labeled cells

    DOE Patents [OSTI]

    Crissman, H.A.; Steinkamp, J.A.

    1987-11-30

    A method is provided for quantifying BrdU labeled DNA in cells. The BrdU is substituted onto the DNA and the DNA is stained with a first fluorochrome having a fluorescence which is quenchable by BrdU. The first fluorochrome is preferably a thymidine base halogen analogue, such as a Hoechst fluorochrome. The DNA is then stained with a second fluorochrome having a fluorescence which is substantially uneffected by BrdU. The second fluorochrome may be selected from the group consisting of mithramycin, chromomycin A3, olivomycin, propidium iodide and ethidium bromine. The fluorescence from the first and second fluorochromes is then measured to obtain first and second output signals, respectively. The first output signal is subtracted from the second output signal to obtain a difference signal which is functionally related to the quantity of BrdU incorporated into DNA. The technique is particularly useful for quantifying the synthesis of DNA during the S-phase of the cell cycle. 2 figs.

  7. ISSUANCE 2014-12-29: Energy Conservation Program: Clarification for Energy Conservation Standards and Test Procedures for Fluorescent Lamp Ballasts

    Broader source: Energy.gov [DOE]

    Energy Conservation Program: Clarification for Energy Conservation Standards and Test Procedures for Fluorescent Lamp Ballasts

  8. Calculation of K-shell fluorescence yields for low-Z elements

    SciTech Connect (OSTI)

    Nekkab, M.; Kahoul, A.; Deghfel, B.; Aylikci, N. Küp; Aylikçi, V.

    2015-03-30

    The analytical methods based on X-ray fluorescence are advantageous for practical applications in a variety of fields including atomic physics, X-ray fluorescence surface chemical analysis and medical research and so the accurate fluorescence yields (?{sub K}) are required for these applications. In this contribution we report a new parameters for calculation of K-shell fluorescence yields (?{sub K}) of elements in the range of 11?Z?30. The experimental data are interpolated by using the famous analytical function (?{sub k}/(1??{sub k})){sup 1/q} (were q=3, 3.5 and 4) vs Z to deduce the empirical K-shell fluorescence yields. A comparison is made between the results of the procedures followed here and those theoretical and other semi-empirical fluorescence yield values. Reasonable agreement was typically obtained between our result and other works.

  9. A light diet for a giant appetite: An assessment of China's proposed fluorescent lamp standard

    SciTech Connect (OSTI)

    Lin, Jiang

    2002-04-11

    Lighting has been one of the fastest growing electric end-uses in China over the last twenty years, with an average annual growth rate of 14%. Fluorescent lighting provides a significant portion of China's lighting need. In 1998, China produced 680 million fluorescent lamps, of which 420 million were linear fluorescent lamps of various diameters (T8 to T12). There are substantial variations both in energy efficiency and lighting performance among locally produced fluorescent lamps. Such variations present a perfect opportunity for policy intervention through efficiency standards to promote the adoption of more efficient fluorescent lamps in China. This paper analyzes China's proposed minimum efficiency standard for fluorescent lamps and presents an assessment of its likely impacts on China's lighting energy consumption and GHG emissions.

  10. Evaluating the variability of ceramics with x-ray fluorescence

    SciTech Connect (OSTI)

    Crown, P.L.; Schwalbe, L.A.; London, J.R.

    1984-01-01

    Our assessment of prehistoric trade in ceramics depends on our ability to identify and distinguish different sources of manufacture. For the American Southwest, archaeologists have proposed various models of ceramic manufacture and exchange. Until recently, conflicting hypotheses were tested mainly on the basis of petrographic analysis of nonplastic tempering materials. We have extended these analyses to include x-ray fluorescence (XRF). XRF provides a fast and inexpensive means of analyzing large numbers of samples. Since 1982, approximately 500 prehistoric sherds and 40 prepared clay and mineral samples have been examined with XRF. Multivariate statistical techniques have been applied to help identify groupings of samples with possible archaeological significance.

  11. Blue-green phosphor for fluorescent lighting applications

    DOE Patents [OSTI]

    Srivastava, Alok; Comanzo, Holly; Manivannan, Venkatesan; Setlur, Anant Achyut

    2005-03-15

    A fluorescent lamp including a phosphor layer including Sr.sub.4 Al.sub.14 O.sub.25 :Eu.sup.2+ (SAE) and at least one of each of a red, green and blue emitting phosphor. The phosphor layer can optionally include an additional, deep red phosphor and a yellow emitting phosphor. The resulting lamp will exhibit a white light having a color rendering index of 90 or higher with a correlated color temperature of from 2500 to 10000 Kelvin. The use of SAE in phosphor blends of lamps results in high CRI light sources with increased stability and acceptable lumen maintenance over, the course of the lamp life.

  12. Rapid identification of bacteria using an umbelliferone fluorescent assay 

    E-Print Network [OSTI]

    Chamblin, Richard Thomas

    1983-01-01

    . Corgnebacterium seudotuberculosis KF which formed hard, dry colonies; or sr 1 11 ~11' LM h1*h f 4 * pt' lly " t"c colonies), 2 loopfulls of' bacteria per ml were estimated. Estimating 2 loopfulls proved to be an acceptable variation in the technique. Wet.... Quarles ( Co-Chairman of Committee) Charles F. Hall ( ember) L. C. Grumbles ( Member) B. G. Foster Head of Depar t) Ian R. Tiz r August 1983 ABSTRACT Rapid Identification of Bacteria Using an Umbelliferone Fluorescent Assay, (August 1983) Richard...

  13. A Fluorescent Approach for Identifying P2X1 Ligands

    E-Print Network [OSTI]

    Ruepp, Marc-David; Brozik, James A.; de Esch, Iwan J. P.; Farndale, Richard W.; Murrell-Lagnado, Ruth D.; Thompson, Andrew J.

    2015-05-28

    by Richard Evans (Leicester University, UK). Plasmids: A FLAG-tagged human P2X1 subunit expression construct was created by fusion PCR. The fragment was cloned together with an IRES-IFP1.4 (Shu et al., Science 2009; 324 no.5928) fusion PCR product... 4 ligands, supporting our notion that fluorescence-based methods provide a valuable research tool (Hernandez-Olmos et al., 2012). Other methods such as surface 19 plasmon resonance (SPR), nuclear magnetic resonance (NMR), X-ray structure...

  14. Rigidifying Fluorescent Linkers by Metal-Organic Framework Formation for

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid youOxygen Generation |Publications|RetireeTechnologiesFluorescence Blue

  15. Better Fluorescent Lighting Through Physics | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuels DataEnergy Webinar:I DueBETO Quiz -Technologies for HybridBetterFluorescent

  16. Air Fluorescence Relevant for Cosmic-Ray Detection - Review of Pioneering Measurements

    E-Print Network [OSTI]

    Fernando Arqueros; Joerg R. Hoerandel; Bianca Keilhauer

    2008-07-24

    Cosmic rays with energies exceeding $10^{17}$ eV are frequently registered by measurements of the fluorescence light emitted by extensive air showers. The main uncertainty for the absolute energy scale of the measured air showers is coming from the fluorescence light yield of electrons in air. The fluorescence light yield has been studied in laboratory experiments. Pioneering measurements between 1954 and 2000 are reviewed.

  17. Microcavity effects on the generation,fluorescence, and diffusion of excitons in organic solar cells

    E-Print Network [OSTI]

    Kozyreff, G; Vuong, L T; Silleras, O Nieto; Martorell, J

    2013-01-01

    We compute the short-circuit diffusion current of excitons in an organic solar cell, with special emphasis on fluorescence losses. The exciton diffusion length is not uniform but varies with its position within the device, even with moderate fluorescence quantum efficiency. With large quantum efficiencies, the rate of fluorescence can be strongly reduced with proper choices of the geometrical and dielectric parameters. In this way, the diffusion length can be increased and the device performance significantly improved.

  18. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, Ryszard J. (Ames, IA); Small, Gerald J. (Ames, IA); Shields, Peter A. (Reading, MA)

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes.

  19. Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection of Small Molecules

    E-Print Network [OSTI]

    Tan, Weihong

    Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection graphene oxide (GO) as the signal amplifier. Because of the extraordinarily larger volume of GO

  20. Transmission Nuclear Resonance Fluorescence Measurements of 238U in Thick Targets

    E-Print Network [OSTI]

    Quiter, Brian J.

    2011-01-01

    G. Rusev, and A.P. Tonchev, Transmission-based detection ofas it traverses the transmission detection sheet. The secondTransmission Nuclear Resonance Fluorescence Measurements of

  1. Excitation-emission spectra and fluorescence quantum yields for fresh and aged biogenic secondary organic aerosols

    SciTech Connect (OSTI)

    Lee, Hyun Ji; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey A.

    2013-05-10

    Certain biogenic secondary organic aerosols (SOA) become absorbent and fluorescent when exposed to reduced nitrogen compounds such as ammonia, amines and their salts. Fluorescent SOA may potentially be mistaken for biological particles by detection methods relying on fluorescence. This work quantifies the spectral distribution and effective quantum yields of fluorescence of SOA generated from two monoterpenes, limonene and a-pinene, and two different oxidants, ozone (O3) and hydroxyl radical (OH). The SOA was generated in a smog chamber, collected on substrates, and aged by exposure to ~100 ppb ammonia vapor in air saturated with water vapor. Absorption and excitation-emission matrix (EEM) spectra of aqueous extracts of aged and control SOA samples were measured, and the effective absorption coefficients and fluorescence quantum yields (~0.005 for 349 nm excitation) were determined from the data. The strongest fluorescence for the limonene-derived SOA was observed for excitation = 420+- 50 nm and emission = 475 +- 38 nm. The window of the strongest fluorescence shifted to excitation = 320 +- 25 nm and emission = 425 +- 38 nm for the a-pinene-derived SOA. Both regions overlap with the excitation-emission matrix (EEM) spectra of some of the fluorophores found in primary biological aerosols. Our study suggests that, despite the low quantum yield, the aged SOA particles should have sufficient fluorescence intensities to interfere with the fluorescence detection of common bioaerosols.

  2. High power light emitting diode based setup for photobleaching fluorescent impurities

    E-Print Network [OSTI]

    Kaufman, Laura

    High power light emitting diode based setup for photobleaching fluorescent impurities Tobias K be photobleached before final sample preparation. The instrument consists of high power light emitting diodes

  3. Fluorescence-based detection methodologies for nitric oxide using transition metal scaffolds

    E-Print Network [OSTI]

    Hilderbrand, Scott A. (Scott Alan), 1976-

    2004-01-01

    Chapter 1. Fluorescence-Based Detection Methodologies for Nitric Oxide: A Review. Chapter 2. Cobalt Chemistry with Mixed Aminotroponimine Salicylaldimine Ligands: Synthesis, Characterization, and Nitric Oxide Reactivity. ...

  4. Lung Cancer (2005) 47, 41--47 Improving the specificity of fluorescence

    E-Print Network [OSTI]

    Duin, Robert P.W.

    2005-01-01

    Lung Cancer (2005) 47, 41--47 Improving the specificity of fluorescence bronchoscopy spectroscopy; Lung cancer; Bronchoscopy Summary Detection of malignancies of the bronchial tree in an early

  5. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, R.J.; Small, G.J.; Shields, P.A.

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes. 21 figs.

  6. Nuclear Resonance Fluorescence at MIT | U.S. DOE Office of Science...

    Office of Science (SC) Website

    Resonance Fluorescence at MIT Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear...

  7. Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

    E-Print Network [OSTI]

    Ludewigt, Bernhard A

    2011-01-01

    and Nuclear Recoil . . . . . . . . . . . . . . . . . . . . .2 Quantitative Measurements using NRF 2.1 Nuclear ResonanceFuture Work A Transmission Nuclear Resonance Fluorescence

  8. EA-1881: Energy Conservation Program: Energy Conservation Standards for Fluorescent Lamp Ballasts

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts of a proposal to amend energy conservation standards for various consumer products and certain commercial and industrial equipment, including fluorescent lamp ballasts.

  9. Anatomy-Based Algorithms for Detecting Oral Cancer Using Reflectance and Fluorescence Spectroscopy

    E-Print Network [OSTI]

    McGee, Sasha

    OBJECTIVES: We used reflectance and fluorescence spectroscopy to noninvasively and quantitatively distinguish benign from dysplastic/malignant oral lesions. We designed diagnostic algorithms to account for differences in ...

  10. Fluorescence spectrum analysis using Fourier series modeling for Fluorescein solution in Ethanol

    E-Print Network [OSTI]

    Hadi, Mahasin F

    2011-01-01

    We have measured the fluorescence spectrum for fluorescein solution in ethanol with concentration 1 {\\times} 10-3 mol/liter at different temperatures from room temperature to freezing point of solvent, (T = 153, 183, 223, 253, and 303 K) using liquid nitrogen. Table curve 2D version 5.01 program has been used to determine the fitting curve and fitting equation for each fluorescence spectrum. Fourier series (3 {\\times} 2) was the most suitable fitting equation for all spectra. Theoretical fluorescence spectrum of fluorescein in ethanol at T = 183K was calculated and compared with experimental fluorescence spectrum at the same temperature. There is a good similarity between them.

  11. Diagnosing breast cancer using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy

    E-Print Network [OSTI]

    Fitzmaurice, Maryann

    Using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy, we have developed an algorithm that successfully classifies normal breast tissue, fibrocystic change, fibroadenoma, and infiltrating ductal ...

  12. Cerenkov emission induced by external beam radiation stimulates molecular fluorescence

    SciTech Connect (OSTI)

    Axelsson, Johan; Davis, Scott C.; Gladstone, David J.; Pogue, Brian W.

    2011-07-15

    Purpose: Cerenkov emission is induced when a charged particle moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons in everyday radiation therapy of tissue; yet, this phenomenon has never been fully documented. This study quantifies the emissions and also demonstrates that the Cerenkov emission can excite a fluorophore, protoporphyrin IX (PpIX), embedded in biological phantoms. Methods: In this study, Cerenkov emission induced by radiation from a clinical linear accelerator is investigated. Biological mimicking phantoms were irradiated with x-ray photons, with energies of 6 or 18 MV, or electrons at energies 6, 9, 12, 15, or 18 MeV. The Cerenkov emission and the induced molecular fluorescence were detected by a camera or a spectrometer equipped with a fiber optic cable. Results: It is shown that both x-ray photons and electrons, at MeV energies, produce optical Cerenkov photons in tissue mimicking media. Furthermore, we demonstrate that the Cerenkov emission can excite a fluorophore, protoporphyrin IX (PpIX), embedded in biological phantoms. Conclusions: The results here indicate that molecular fluorescence monitoring during external beam radiotherapy is possible.

  13. Protein- protein interaction detection system using fluorescent protein microdomains

    DOE Patents [OSTI]

    Waldo, Geoffrey S. (Santa Fe, NM); Cabantous, Stephanie (Los Alamos, NM)

    2010-02-23

    The invention provides a protein labeling and interaction detection system based on engineered fragments of fluorescent and chromophoric proteins that require fused interacting polypeptides to drive the association of the fragments, and further are soluble and stable, and do not change the solubility of polypeptides to which they are fused. In one embodiment, a test protein X is fused to a sixteen amino acid fragment of GFP (.beta.-strand 10, amino acids 198-214), engineered to not perturb fusion protein solubility. A second test protein Y is fused to a sixteen amino acid fragment of GFP (.beta.-strand 11, amino acids 215-230), engineered to not perturb fusion protein solubility. When X and Y interact, they bring the GFP strands into proximity, and are detected by complementation with a third GFP fragment consisting of GFP amino acids 1-198 (strands 1-9). When GFP strands 10 and 11 are held together by interaction of protein X and Y, they spontaneous association with GFP strands 1-9, resulting in structural complementation, folding, and concomitant GFP fluorescence.

  14. Red phosphors for use in high CRI fluorescent lamps

    DOE Patents [OSTI]

    Srivastava, Alok; Comanzo, Holly; Manivannan, Vankatesan; Setlur, Anant Achyut

    2005-11-15

    Novel red emitting phosphors for use in fluorescent lamps resulting in superior color rendering index values compared to conventional red phosphors. Also disclosed is a fluorescent lamp including a phosphor layer comprising blends of one or more of a blue phosphor, a blue-green phosphor, a green phosphor and a red a phosphor selected from the group consisting of SrY.sub.2 O.sub.4 :Eu.sup.3+, (Y,Gd)Al.sub.3 B.sub.4 O.sub.12 :Eu.sup.3+, and [(Y.sub.1-x-y-m La.sub.y)Gd.sub.x ]BO.sub.3 :Eu.sub.m wherein y<0.50 and m=0.001-0.3. The phosphor layer can optionally include an additional deep red phosphor and a yellow emitting phosphor. The resulting lamp will exhibit a white light having a color rendering index of 90 or higher with a correlated color temperature of from 2500 to 10000 Kelvin. The use of the disclosed red phosphors in phosphor blends of lamps results in high CRI light sources with increased stability and acceptable lumen maintenance over the course of the lamp life.

  15. Status of the Silicon Photomultiplier Telescope FAMOUS for the Fluorescence Detection of UHECRs

    E-Print Network [OSTI]

    Niggemann, Tim; Brogueira, Pedro; Bueno, Antonio; Eichler, Hans Michael; Ferreira, Miguel; Hebbeker, Thomas; Lauscher, Markus; Mendes, Luís; Middendorf, Lukas; Navas, Sergio; Peters, Christine; Pimenta, Mário; Ruiz, Angel; Schumacher, Johannes; Stephan, Maurice

    2015-01-01

    An established technique for the measurement of ultra-high-energy-cosmic-rays is the detection of the fluorescence light induced in the atmosphere of the Earth, by means of telescopes equipped with photomultiplier tubes. Silicon photomultipliers (SiPMs) promise an increase in the photon detection efficiency which outperforms conventional photomultiplier tubes. In combination with their compact package, a moderate bias voltage of several ten volt and single photon resolution, the use of SiPMs can improve the energy and spatial resolution of air fluorescence measurements, and lead to a gain in information on the primary particle. Though, drawbacks like a high dark-noise-rate and a strong temperature dependency have to be managed. FAMOUS is a refracting telescope prototype instrumented with 64 SiPMs of which the main optical element is a Fresnel lens of 549.7 mm diameter and 502.1 mm focal length. The sensitive area of the SiPMs is increased by a special light collection system consisting of Winston cones. The t...

  16. Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background Behavior

    E-Print Network [OSTI]

    ARTICLE Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella while acquiring Raman signals from the algae. The time dependence of fluorescence background is char

  17. Studies of the laser-induced fluorescence of explosives and explosive compositions.

    SciTech Connect (OSTI)

    Hargis, Philip Joseph, Jr.; Thorne, Lawrence R.; Phifer, Carol Celeste; Parmeter, John Ethan; Schmitt, Randal L.

    2006-10-01

    Continuing use of explosives by terrorists throughout the world has led to great interest in explosives detection technology, especially in technologies that have potential for standoff detection. This LDRD was undertaken in order to investigate the possible detection of explosive particulates at safe standoff distances in an attempt to identify vehicles that might contain large vehicle bombs (LVBs). The explosives investigated have included the common homogeneous or molecular explosives, 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclonite or hexogen (RDX), octogen (HMX), and the heterogeneous explosive, ammonium nitrate/fuel oil (ANFO), and its components. We have investigated standard excited/dispersed fluorescence, laser-excited prompt and delayed dispersed fluorescence using excitation wavelengths of 266 and 355 nm, the effects of polarization of the laser excitation light, and fluorescence imaging microscopy using 365- and 470-nm excitation. The four nitro-based, homogeneous explosives (TNT, PETN, RDX, and HMX) exhibit virtually no native fluorescence, but do exhibit quenching effects of varying magnitude when adsorbed on fluorescing surfaces. Ammonium nitrate and fuel oil mixtures fluoresce primarily due to the fuel oil, and, in some cases, due to the presence of hydrophobic coatings on ammonium nitrate prill or impurities in the ammonium nitrate itself. Pure ammonium nitrate shows no detectable fluorescence. These results are of scientific interest, but they provide little hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability.

  18. Transition in the Temperature-Dependence of GFP Fluorescence: From Proton Wires to Proton Exit

    E-Print Network [OSTI]

    Agmon, Noam

    Transition in the Temperature-Dependence of GFP Fluorescence: From Proton Wires to Proton Exit protein, photo-excitation leads to excited-state proton transfer from its chromophore, leaving behind a strongly fluorescing anion, while the proton is commonly thought to migrate internally to Glu-222. X

  19. Fluorescent-Protein-Based Biosensors: Modulation of Energy Transfer as a Design Principle

    E-Print Network [OSTI]

    Campbell, Robert E.

    Fluorescent-Protein-Based Biosensors: Modulation of Energy Transfer as a Design Principle Robert E. Campbell University of Alberta Genetically-encoded biosensors based on FRET between fluorescent proteins.acs.org/journal/ancham.) The definition of a "biosensor"sthat is, a detection system that relies on a biomolecule for molecular

  20. Optical imaging of non-fluorescent nanodiamonds in live cells using transient absorption microscopy

    E-Print Network [OSTI]

    Huang, Yanyi

    Optical imaging of non-fluorescent nanodiamonds in live cells using transient absorption microscopy non-fluorescent nanodiamonds in living cells using transient absorption microscopy. This label of nanodiamonds under various conditions, confirming the endocytosis mechanism. Optical probes for live cell

  1. Nucleic acid encoding a self-assembling split-fluorescent protein system

    DOE Patents [OSTI]

    Waldo, Geoffrey S; Cabantous, Stephanie

    2014-04-01

    The invention provides a protein labeling and detection system based on self-complementing fragments of fluorescent and chromophoric proteins. The system of the invention is exemplified with various combinations of self-complementing fragments derived from Aequorea victoria Green Fluorescent Protein (GFP), which are used to detect and quantify protein solubility in multiple assay formats, both in vitro and in vivo.

  2. Ultrafast Proton Shuttling in Psammocora Cyan Fluorescent Protein John T. M. Kennis,*,

    E-Print Network [OSTI]

    van Stokkum, Ivo

    States *S Supporting Information ABSTRACT: Cyan, green, yellow, and red fluorescent proteins (FPs) homologous to green fluorescent protein (GFP) are used extensively as model systems to study fundamental processes in photobiology, such as the capture of light energy by protein-embedded chromophores, color

  3. Carbon dioxide UV laser-induced fluorescence in high-pressure flames

    E-Print Network [OSTI]

    Lee, Tonghun

    Carbon dioxide UV laser-induced fluorescence in high-pressure flames W.G. Bessler a , C. Schulz a; in final form 16 May 2003 Published online 10 June 2003 Abstract Laser-induced fluorescence (LIF) of carbon dioxide is investigated with excitation between 215 and 255 nm with spectrally resolved detection in 5

  4. Tuning the Fluorescence Emission Spectra of a Single Molecule with a Variable Optical Subwavelength Metal Microcavity

    E-Print Network [OSTI]

    Enderlein, Jörg

    Tuning the Fluorescence Emission Spectra of a Single Molecule with a Variable Optical Subwavelength on changing the fluorescence emission spectrum of a single molecule by embedding it within a tunable planar and coupling are both frequency dependent, this leads to a renormalization of the emission spectrum

  5. Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: Variable responses

    E-Print Network [OSTI]

    Berges, John A.

    among freshwater microalgae Chang Jae Choi 1 , John. A. Berges, Erica. B. Young* Department a fluorescence of microalgae is a compelling indicator of toxicity of dissolved water contaminants, because on chlorophyll a fluorescence: Variable responses among freshwater microalgae, Water Research (2012), doi:10

  6. A FRET-Facilitated Photoswitching Using an Orange Fluorescent Protein with the Fast Photoconversion Kinetics

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    resonance energy transfer (FRET) from green fluorescent donors. We have termed the latter effect a FRET available photoconvertible green- to-red probes are in high demand. We have developed a monomericEos2,4 Kaede,5 mKikGR,6 mClavGR27 and their derivatives, change their fluorescent color from green

  7. Fully adaptive FEM based fluorescence optical tomography from time-dependent measurements with area illumination

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    Fully adaptive FEM based fluorescence optical tomography from time-dependent measurements with area fluorescence absorption map with an adaptive finite element based scheme. The tissue phantom consisted 785 nm diode laser light and a gain modulated image intensified charge coupled device camera

  8. Spectroscopic Properties of a Self-Assembled Zinc Porphyrin Tetramer II. Time-Resolved Fluorescence Spectroscopy

    E-Print Network [OSTI]

    van Stokkum, Ivo

    Spectroscopic Properties of a Self-Assembled Zinc Porphyrin Tetramer II. Time-Resolved Fluorescence tetramer [Part I], with a 1 ns rotational correlation time at 10 °C. The initial fluorescence anisotropy of the monomer is found to be 0.1. In the tetramer an additional depolarization process occurs with a correlation

  9. Plasmon-controlled fluorescence: A new detection technology Joseph R. Lakowicz*a

    E-Print Network [OSTI]

    Turro, Nicholas J.

    Plasmon-controlled fluorescence: A new detection technology Joseph R. Lakowicz*a , Mustafa H fundamentally change and increase the capabilities of fluorescence technology. This change will be based to control the decay rates, location and direction of fluorophore emission. We refer to this technology

  10. Directed evolution methods for improving polypeptide folding and solubility and superfolder fluorescent proteins generated thereby

    DOE Patents [OSTI]

    Waldo, Geoffrey S. (Santa Fe, NM)

    2007-09-18

    The current invention provides methods of improving folding of polypeptides using a poorly folding domain as a component of a fusion protein comprising the poorly folding domain and a polypeptide of interest to be improved. The invention also provides novel green fluorescent proteins (GFPs) and red fluorescent proteins that have enhanced folding properties.

  11. In Vitro Transport of a Fluorescent Nuclear Protein and Exclusion of Non-Nuclear Proteins

    E-Print Network [OSTI]

    Forbes, Douglass

    In Vitro Transport of a Fluorescent Nuclear Protein and Exclusion of Non-Nuclear Proteins Donald D microscopic assay for nuclear transport. The assay uses an extract of Xenopus eggs, normal or synthetic nuclei, and a fluorescently labeled nuclear protein, nucleoplasmin. This in vitro system accurately mimics in vivo nuclear

  12. Classification with Artificial Neural Networks and Support Vector Machines: application to oil fluorescence spectra

    E-Print Network [OSTI]

    Oldenburg, Carl von Ossietzky Universität

    be applied to predict the profit, market movements, and price level based on the market's historical datasetClassification with Artificial Neural Networks and Support Vector Machines: application to oil, and Oil fluorescence ABSTRACT: This paper reports on oil classification with fluorescence spectroscopy

  13. Reverse engineering the ancient ceramic technology based on X-ray fluorescence spectromicroscopy

    E-Print Network [OSTI]

    Reverse engineering the ancient ceramic technology based on X-ray fluorescence spectromicroscopy-ray fluorescence (XRF) microprobe analyses of ancient ceramic cross-sections aiming at deciphering the different and Fe K-edge X-ray absorption near edge structure spectroscopy were performed on pre-sigillata ceramics

  14. Nucleic acid encoding a self-assembling split-fluorescent protein system

    DOE Patents [OSTI]

    Waldo, Geoffrey S. (Santa Fe, NM); Cabantous, Stephanie (Los Alamos, NM)

    2011-06-07

    The invention provides a protein labeling and detection system based on self-complementing fragments of fluorescent and chromophoric proteins. The system of the invention is exemplified with various combinations of self-complementing fragments derived from Aequorea victoria Green Fluorescent Protein (GFP), which are used to detect and quantify protein solubility in multiple assay formats, both in vitro and in vivo.

  15. Long wave fluorophore sensor compounds and other fluorescent sensor compounds in polymers

    DOE Patents [OSTI]

    Walsh, Joseph C.; Heiss, Aaron M.; Noronha, Glenn; Vachon, David J.; Lane, Stephen M.; Satcher, Jr., Joe H.; Peyser, Thomas A.; Van Antwerp, William Peter; Mastrototaro, John Joseph

    2004-07-20

    Fluorescent biosensor molecules, fluorescent biosensors and systems, as well as methods of making and using these biosensor molecules and systems are described. Embodiments of these biosensor molecules exhibit fluorescence emission at wavelengths greater than about 650 nm. Typical biosensor molecules include a fluorophore that includes an iminium ion, a linker moiety that includes a group that is an anilinic type of relationship to the fluorophore and a boronate substrate recognition/binding moiety, which binds glucose. The fluorescence molecules modulated by the presence or absence of polyhydroxylated analytes such as glucose. This property of these molecules of the invention, as well as their ability to emit fluorescent light at greater than about 650 nm, renders these biosensor molecules particularly well-suited for detecting and measuring in-vivo glucose concentrations.

  16. Hyperspectral image reconstruction for x-ray fluorescence tomography

    SciTech Connect (OSTI)

    Gürsoy, Do?a; Biçer, Tekin; Lanzirotti, Antonio; Newville, Matthew G.; De Carlo, Francesco

    2015-01-01

    A penalized maximum-likelihood estimation is proposed to perform hyperspectral (spatio-spectral) image reconstruction for X-ray fluorescence tomography. The approach minimizes a Poisson-based negative log-likelihood of the observed photon counts, and uses a penalty term that has the effect of encouraging local continuity of model parameter estimates in both spatial and spectral dimensions simultaneously. The performance of the reconstruction method is demonstrated with experimental data acquired from a seed of arabidopsis thaliana collected at the 13-ID-E microprobe beamline at the Advanced Photon Source. The resulting element distribution estimates with the proposed approach show significantly better reconstruction quality than the conventional analytical inversion approaches, and allows for a high data compression factor which can reduce data acquisition times remarkably. In particular, this technique provides the capability to tomographically reconstruct full energy dispersive spectra without compromising reconstruction artifacts that impact the interpretation of results.

  17. Semiconductor Quantum Rods as Single Molecule FluorescentBiological Labels

    SciTech Connect (OSTI)

    Fu, Aihua; Gu, Weiwei; Boussert, Benjamine; Koski, Kristie; Gerion, Daniele; Manna, Liberato; Le Gros, Mark; Larabell, Carolyn; Alivisatos, A. Paul

    2006-05-29

    In recent years, semiconductor quantum dots have beenapplied with great advantage in a wide range of biological imagingapplications. The continuing developments in the synthesis of nanoscalematerials and specifically in the area of colloidal semiconductornanocrystals have created an opportunity to generate a next generation ofbiological labels with complementary or in some cases enhanced propertiescompared to colloidal quantum dots. In this paper, we report thedevelopment of rod shaped semiconductor nanocrystals (quantum rods) asnew fluorescent biological labels. We have engineered biocompatiblequantum rods by surface silanization and have applied them fornon-specific cell tracking as well as specific cellular targeting. Theproperties of quantum rods as demonstrated here are enhanced sensitivityand greater resistance for degradation as compared to quantum dots.Quantum rods have many potential applications as biological labels insituations where their properties offer advantages over quantumdots.

  18. Hyperspectral image reconstruction for x-ray fluorescence tomography

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gürsoy, Do?a; Biçer, Tekin; Lanzirotti, Antonio; Newville, Matthew G.; De Carlo, Francesco

    2015-01-01

    A penalized maximum-likelihood estimation is proposed to perform hyperspectral (spatio-spectral) image reconstruction for X-ray fluorescence tomography. The approach minimizes a Poisson-based negative log-likelihood of the observed photon counts, and uses a penalty term that has the effect of encouraging local continuity of model parameter estimates in both spatial and spectral dimensions simultaneously. The performance of the reconstruction method is demonstrated with experimental data acquired from a seed of arabidopsis thaliana collected at the 13-ID-E microprobe beamline at the Advanced Photon Source. The resulting element distribution estimates with the proposed approach show significantly better reconstruction quality than the conventional analytical inversionmore »approaches, and allows for a high data compression factor which can reduce data acquisition times remarkably. In particular, this technique provides the capability to tomographically reconstruct full energy dispersive spectra without compromising reconstruction artifacts that impact the interpretation of results.« less

  19. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 ?M with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase themore »concentration range of FCS are not necessary, and further increases above 38 ?M may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.« less

  20. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

    SciTech Connect (OSTI)

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 ?M with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase the concentration range of FCS are not necessary, and further increases above 38 ?M may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.

  1. A Study of the Fluorescence Response of Tetraphenyl-butadiene

    E-Print Network [OSTI]

    Jerry, R; Bugel, L; Conrad, J M

    2010-01-01

    Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultiplier tubes. This paper presents studies on the stability of TPB with time under exposure to light. We also examine batch-to-batch variations. We compare scintillation-grade TPB to 99% pure TPB response. In the 99% pure samples, we report a yellowing effect, and full degradation of the TPB emission-peak, upon extended exposure to light.

  2. Zero energy-storage ballast for compact fluorescent lamps

    DOE Patents [OSTI]

    Schultz, W.N.; Thomas, R.J.

    1999-08-31

    A CFL ballast includes complementary-type switching devices connected in series with their gates connected together at a control node. The switching devices supply a resonant tank circuit which is tuned to a frequency near, but slightly lower than, the resonant frequency of a resonant control circuit. As a result, the tank circuit restarts oscillations immediately following each zero crossing of the bus voltage. Such rapid restarts avoid undesirable flickering while maintaining the operational advantages and high efficacy of the CFL ballast. 4 figs.

  3. Compact Fluorescent Lighting in America: Lessons Learned on the...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Consumer Light Bulb Changes: Briefing and Resources for Media and Retailers Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Evaluation...

  4. Conservation Potential of Compact Fluorescent Lamps in India and Brazil

    E-Print Network [OSTI]

    Gadgil, A.J.

    2008-01-01

    coal-fired) thermal power stations in its expansion ofcapacity. Its thermal power stations now contribute aboutlead time for thermal power stations, and less legal and

  5. Conservation Potential of Compact Fluorescent Lamps in India and Brazil

    E-Print Network [OSTI]

    Gadgil, A.J.

    2008-01-01

    1988. The private sector in Brazil owned (in 1986) 40% ofElectricity Conservation in Brazil: Potential and Pro-electricity consumption in Brazil's residential sector was

  6. Conservation Potential of Compact Fluorescent Lamps in India and Brazil

    E-Print Network [OSTI]

    Gadgil, A.J.

    2008-01-01

    Ministry of Energy, Government of India, Annual Report 1087-of the Solar Energy Society of India, SESI-J, Vol. 1,without decreasing energy services in India and Brazil. The

  7. Conservation Potential of Compact Fluorescent Lamps in India and Brazil

    E-Print Network [OSTI]

    Gadgil, A.J.

    2008-01-01

    1.7% of in- stalled hydroelectric capacity. Op. cit. ref [in Ig86) based on hydroelectric generation, and most of thethe still abundant hydroelectric potential of the country.

  8. Conservation Potential of Compact Fluorescent Lamps in India and Brazil

    E-Print Network [OSTI]

    Gadgil, A.J.

    2008-01-01

    Residential Energy Demand in Brazil and Income Classes:in Brazil: Potential and Pro- gress", ENERGY, vol. 13, no.decreasing energy services in India and Brazil. The initial

  9. Energy Cost Calculator for Compact Fluorescent Lamps | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n cEnergy (AZ,LocalEfficiency |< Back Eligibility<tool calculates

  10. Medium Base Compact Fluorescent Lamps | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE Safetyof Energy ThisSitesStoragePlanningEnergy UseMedium Base

  11. Lighting the Way with Compact Fluorescent Lighting | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested Parties - WAPA PublicLED ADOPTIONtoLighting System Optimization:Lighting the

  12. Cyanine-based probe\\tag-peptide pair for fluorescence protein imaging and fluorescence protein imaging methods

    DOE Patents [OSTI]

    Mayer-Cumblidge, M. Uljana (Richland, WA); Cao, Haishi (Richland, WA)

    2010-08-17

    A molecular probe comprises two arsenic atoms and at least one cyanine based moiety. A method of producing a molecular probe includes providing a molecule having a first formula, treating the molecule with HgOAc, and subsequently transmetallizing with AsCl.sub.3. The As is liganded to ethanedithiol to produce a probe having a second formula. A method of labeling a peptide includes providing a peptide comprising a tag sequence and contacting the peptide with a biarsenical molecular probe. A complex is formed comprising the tag sequence and the molecular probe. A method of studying a peptide includes providing a mixture containing a peptide comprising a peptide tag sequence, adding a biarsenical probe to the mixture, and monitoring the fluorescence of the mixture.

  13. Using co-cultures expressing fluorescence resonance energy transfer based protein biosensors to simultaneously image caspase-3 and Ca2+

    E-Print Network [OSTI]

    Using co-cultures expressing fluorescence resonance energy transfer based protein biosensors received: 8 June 2005; Accepted 11 June 2005 Key words: biosensor, fluorescence imaging, fluorescence)-based protein biosensors allow the spatial and temporal imaging of signaling events in living cells. However

  14. Improved model for the analysis of air fluorescence induced by electrons

    E-Print Network [OSTI]

    F. Arqueros; F. Blanco; J. Rosado

    2008-07-24

    A model recently proposed for the calculation of air-fluorescence yield excited by electrons is revisited. Improved energy distributions of secondary electrons and a more realistic Monte Carlo simulation including some additional processes have allowed us to obtain more accurate results. The model is used to study in detail the relationship between fluorescence intensity and deposited energy in a wide range of primary energy (keVs - GeVs). In addition, predictions on the absolute value of the fluorescence efficiency in the absence of collisional quenching will be presented and compared with available experimental data.

  15. Continuous Flow Cryostat for X-Ray Fluorescence

    SciTech Connect (OSTI)

    Weng, T.-C.; Linden, Peter J. E. M. van der; Glatzel, Pieter; Lapras, Christophe; Krzyzowski, Michael

    2010-06-23

    A continuous Helium flow cryostat was designed and built by Cryovac GMbH to specifications given by ESRF beamline ID26. The beamline has constructed a high energy resolution X-ray emission spectrometer using multiple spherically bent analyser crystals, together with the sample and detector on a vertical Rowland circle. The double shrouded cryostat has a low profile designed to fit into the spectrometer setup, the lowest detector position allows for a Bragg angle of 85 degrees with a 1 meter diameter Rowland circle. The cryostat has a temperature range of 5 to 300 Kelvin on the sample holder which is cooled by static Helium exchange gas. The cryostat has triple windows for beam entrance, transmission and fluorescence; the latter offers an opening angle of 80 degrees horizontally and 50 degrees vertically. The cryostat can be configured to work in two different operation modes: translation or rotation. The translation mode offers a displacement of 50 mm to accommodate multiple samples on the sample holder. The rotation mode is used for polarisation studies on single crystals.We show recent results obtained on Chromium containing molecular complexes; data collection was done at a temperature of 10 Kelvin to avoid radiation damage.

  16. Magnetic fluorescent ballasts: Market data, market imperfections, and policy success

    SciTech Connect (OSTI)

    Koomey, J.G.; Sanstad, A.H.; Shown, L.J.

    1995-12-01

    Many economists have strongly questioned engineering-economic studies aimed at demonstrating anomalously slow diffusion of energy-efficient technology and the benefits of regulations to promote such technology. One argument against such studies is that standard techniques of engineering-economics are either inappropriate for or are routinely misapplied in assessing the performance of the market for energy efficiency. This paper presents engineering-economic evidence on the diffusion of energy efficiency improvements that takes account of such critiques. The authors examine the engineering and economic characteristics of standard and energy-efficient magnetic ballasts for fluorescent lighting. Efficient magnetic ballasts represented an excellent investment for 99% of the commercial building floor stock, and a moderately good investment for 0.7% of the commercial floor stock. Still, these ballasts were only being adopted in the 1980s at a rate commensurate with the enactment of appliance efficiency standards in various states. In this case, there is solid empirical evidence for skepticism about the effectiveness of the market mechanism in promoting cost-effective energy efficiency improvements as well as evidence of the benefits of regulation to counteract this shortcoming.

  17. Fluorescence from a quantum dot and metallic nanosphere hybrid system

    SciTech Connect (OSTI)

    Schindel, Daniel G. [Department of Mathematics and Statistics, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB, R3B 2E9 (Canada); Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON, N6A 3K7 (Canada)

    2014-03-31

    We present energy absorption and interference in a quantum dot-metallic nanosphere system embedded on a dielectric substrate. A control field is applied to induce dipole moments in the nanosphere and the quantum dot, and a probe field is applied to monitor absorption. Dipole moments in the quantum dot or the metal nanosphere are induced, both by the external fields and by each other's dipole fields. Thus, in addition to direct polarization, the metal nanosphere and the quantum dot will sense one another via the dipole-dipole interaction. The density matrix method was used to show that the absorption spectrum can be split from one peak to two peaks by the control field, and this can also be done by placing the metal sphere close to the quantum dot. When the two are extremely close together, a self-interaction in the quantum dot produces an asymmetry in the absorption peaks. In addition, the fluorescence efficiency can be quenched by the addition of a metal nanosphere. This hybrid system could be used to create ultra-fast switching and sensing nanodevices.

  18. LED-Induced Fluorescence System for Tea Classification and Quality Assessment

    E-Print Network [OSTI]

    Dong, Yongjiang; Mei, Liang; Feng, Chao; Yan, Chunsheng; He, Sailing

    2013-01-01

    A fluorescence system is developed by using several light emitting diodes (LEDs) with different wavelengths as excitation light sources. The fluorescence detection head consists of multi LED light sources and a multimode fiber for fluorescence collection, where the LEDs and the corresponding filters can be easily chosen to get appropriate excitation wavelengths for different applications. By analyzing fluorescence spectra with the principal component analysis method, the system is utilized in the classification of four types of green tea beverages and two types of black tea beverages. Qualities of the Xihu Longjing tea leaves of different grades, as well as the corresponding liquid tea samples, are studied to further investigate the ability and application of the system in the evaluation of classification/quality of tea and other foods.

  19. Antibody-Antigen assay design for combined optical tweezers and fluorescence

    E-Print Network [OSTI]

    Ta, Jenny, 1982-

    2004-01-01

    The recent development in combined optical trapping and fluorescence technology promises to enable unbindinig force studies of receptor-ligand interactions, whose specificity play a crucial role in the function of many ...

  20. A detection instrument for enhanced-fluorescence and label-free imaging on photonic

    E-Print Network [OSTI]

    Cunningham, Brian

    A detection instrument for enhanced- fluorescence and label-free imaging on photonic crystal detection of dye-tagged hybridized DNA yields 3x more genes to be detected versus commercially available

  1. Genetically encoded biosensors based on engineered fluorescent proteins Wolf B. Frommer, Michael W. Davidson, Robert Campbell

    E-Print Network [OSTI]

    Campbell, Robert E.

    Genetically encoded biosensors based on engineered fluorescent proteins Wolf B. Frommer, Michael W. Davidson, Robert Campbell Supplementary Table I. List of biosensors based on single polypeptide chains Biosensor specificity Representative biosensor(s) Reference(s) Translocation-based biosensors

  2. Metal-based turn-on fluorescent probes for nitric oxide sensing

    E-Print Network [OSTI]

    Lim, Mi Hee

    2006-01-01

    Chapter 1. Metal-Based Turn-On Fluorescent Probes for Sensing Nitric Oxide. Nitric oxide, a reactive free radical, regulates a variety of biological processes. The absence of tools to detect NO directly, rapidly, specifically ...

  3. Turn-on fluorescent probes for detecting nitric oxide in biology

    E-Print Network [OSTI]

    McQuade, Lindsey Elizabeth, 1981-

    2010-01-01

    Chapter 1. Investigating the Biological Roles of Nitric Oxide and Other Reactive Nitrogen Species Using Fluorescent Probes: This chapter presents an overview of recent progress in the field of reactive nitrogen species ...

  4. Organelle-selective energy transfer: A fluorescent indicator of intracellular environment

    E-Print Network [OSTI]

    Burgess, Kevin

    Organelle-selective energy transfer: A fluorescent indicator of intracellular environment Aurore emission wavelength of a dye changes significantly with its intra- cellular environment. Probes monitoring dynamic organelle specific functions. Our group has an ongoing interest in `energy transfer

  5. Examining 239Pu and 240Pu Nuclear Resonance Fluorescence Measurements on Spent Fuel for Nuclear Safeguards

    E-Print Network [OSTI]

    Quiter, Brian

    2013-01-01

    10- 01096) Journal of Nuclear Technology, p. 150, Vol. 175,linac and laser technologies for nuclear photonics gamma-rayNuclear resonance fluorescence (NRF) has been identified as a technology

  6. Fast Flow Microfluidics and Single-Molecule Fluorescence for the Rapid Characterization of ?-Synuclein Oligomers

    E-Print Network [OSTI]

    Horrocks, Mathew H.; Tosatto, Laura; Dear, Alexander J.; Garcia, Gonzalo A.; Iljina, Marija; Cremades, Nunilo; Serra, Mauro Dalla; Knowles, Tuomas P. J.; Dobson, Christopher M.; Klenerman, David

    2015-08-10

    traditional biochemical techniques. By combining fast-flow microfluidics with single-molecule fluorescence, we are able to rapidly follow the process by which oligomers of ?S are formed and to characterize the species themselves. We have used the technique...

  7. Time resolved fluorescence of CdSe nanocrystals using single molecule spectroscopy

    E-Print Network [OSTI]

    Fisher, Brent R

    2005-01-01

    A wide variety of spectroscopic studies of CdSe nanocrystals (NCs) are presented in this thesis, all studying some aspect of the temporal evolution of NC fluorescence tinder different conditions. In particular the methods ...

  8. Experimental Fluorescence Optical Tomography using Adaptive Finite Elements and Planar Illumination with

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    Experimental Fluorescence Optical Tomography using Adaptive Finite Elements and Planar Illumination with Modulated Excitation Light Amit Joshia , Wolfgang Bangerthb , Alan B. Thompsona , and Eva M. Sevick adaptive discretization strategies. To date, the efficacy of adaptive mesh refinement techniques has yet

  9. Measurement and model assessment of fluorescence lifetime sensing in multiply scattering media 

    E-Print Network [OSTI]

    Kuwana, Eddy

    2005-08-29

    implant, the fluorescent decay kinetics can be sensitive to the tissue??s biochemical environment, providing quantitative in vivo information of the confined tissue site. The impact of light propagation and decay kinetics upon the measured signals...

  10. Simulations of time-dependent fluorescence in nano-confined solvents

    E-Print Network [OSTI]

    Thompson, Ward H.

    2004-04-13

    The time-dependent fluorescence of a model diatomic molecule with a charge-transfer electronic transition in confined solvents has been simulated. The effect of confining the solvent is examined by comparing results for solutions contained within...

  11. Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

    E-Print Network [OSTI]

    Ludewigt, Bernhard A

    2011-01-01

    and S.J. Thompson,“Determining Plutonium in Spent Fuel withTobin, “Determination of Plutonium Content in Spent FuelFluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

  12. An improved understanding of fluorescent Zn(II) sensors and their uses in biological settings

    E-Print Network [OSTI]

    Wong, Brian Alexander

    2009-01-01

    Chapter 1. An Introduction to Fluorescent Zn(II) Sensors and Their Applications in Biological Systems This chapter opens with an overview of the numerous roles of zinc in biology, with an emphasis on labile Zn(II), that ...

  13. The Application of Fluorescence Lifetime Imaging Microscopy to Quantitatively Map Mixing and Temperature in Microfluidic Systems 

    E-Print Network [OSTI]

    Graham, Emmelyn M

    2008-01-01

    The technique of Fluorescence Lifetime Imaging Microscopy (FLIM) has been employed to quantitatively and spatially map the fluid composition and temperature within microfluidic systems. A molecular probe with a ...

  14. Generation of embryonic stem cells and transgenic mice expressing green fluorescence protein in midbrain dopaminergic neurons 

    E-Print Network [OSTI]

    Zhao, Suling; Maxwell, Sarah L; Jimenez-Beristain, Antonio; Vives, Joaquim; Kuehner, Eva; Zhao, Jiexin; O'Brian, Carmel; de Felipe, Carmen; Semina, Elena

    2004-01-01

    We have generated embryonic stem cells and transgenic mice with green fluorescent protein (GFP) inserted into the Pitx3 locus via homologous recombination. In the central nervous system, Pitx3 directed GFP was visualised ...

  15. Development and analysis of recombinant fluorescent probes for use in live cell imaging of filamentous fungi 

    E-Print Network [OSTI]

    Altenbach, Kirsten

    2010-01-01

    The molecular cloning and subsequent engineering of the green fluorescent protein (GFP) of the jellyfish Aequoria victoria allowed a novel approach to the investigation of cell signalling. GFP and its mutants can now not ...

  16. Automation of the Laguerre Expansion Technique for Analysis of Time-resolved Fluorescence Spectroscopy Data 

    E-Print Network [OSTI]

    Dabir, Aditi Sandeep

    2010-07-14

    Time-resolved fluorescence spectroscopy (TRFS) is a powerful analytical tool for quantifying the biochemical composition of organic and inorganic materials. The potentials of TRFS as nondestructive clinical tool for tissue diagnosis have been...

  17. Development of a Time Resolved Fluorescence Spectroscopy System for Near Real-Time Clinical Diagnostic Applications 

    E-Print Network [OSTI]

    Trivedi, Chintan A.

    2010-07-14

    The design and development of a versatile time resolved fluorescence spectroscopy (TRFS) system capable of near real time data acquisition and processing for potential clinical diagnostic applications is reported. The TRFS apparatus is portable...

  18. On-line measurement of lignin in wood pulp by color shift of fluorescence

    DOE Patents [OSTI]

    Jeffers, L.A.; Malito, M.L.

    1996-01-23

    Lignin concentrations from wood pulp samples are measured by applying an excitation light at a selected wavelength to the samples in order to cause the lignin to emit fluorescence. A spectral distribution of the fluorescence emission is then determined. The lignin concentration is then calculated based on the spectral distribution signal. The spectral distribution is quantified by either a wavelength centroid method or a band ratio method. 6 figs.

  19. On-line measurement of lignin in wood pulp by color shift of fluorescence

    DOE Patents [OSTI]

    Jeffers, Larry A. (Washington Township, Stark County, OH); Malito, Michael L. (Liberty Township, Trumbull County, OH)

    1996-01-01

    Lignin concentrations from wood pulp samples are measured by applying an excitation light at a selected wavelength to the samples in order to cause the lignin to emit fluorescence. A spectral distribution of the fluorescence emission is then determined. The lignin concentration is then calculated based on the spectral distribution signal. The spectral distribution is quantified by either a wavelength centroid method or a band ratio method.

  20. Quantitative Modeling and Estimation in Systems Biology using Fluorescent Reporter Systems 

    E-Print Network [OSTI]

    Bansal, Loveleena

    2013-12-10

    FIM Fischer Information Matrix FP Fluorescent Protein GFP Green Fluorescent Protein GLS Generalized Least Squares IBVP Intital Boundary Value Problem IL-6 Interleukin-6 IPDE Integro Partial Differential Equation LHS Latin Hypercube... Sampling MSE Mean Squared Error nM Nano Molar O.D. Optical Density ODE Ordinary Differential Equation PBE Population Balance Equation PBM Population Balance Model RE Relative Error S.D. Standard Deviation STAT3 Signal transducer...

  1. Organic light-emitting device with a phosphor-sensitized fluorescent emission layer

    DOE Patents [OSTI]

    Forrest, Stephen (Ann Arbor, MI); Kanno, Hiroshi (Osaka, JP)

    2009-08-25

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters. The emissive region of the devices of the present invention comprise at least one phosphor-sensitized layer which has a combined emission from a phosphorescent emitter and a fluorescent emitter. In preferred embodiments, the invention relates to white-emitting OLEDS (WOLEDs).

  2. Stardust Interstellar Preliminary Examination VI: Quantitative elemental analysis by synchrotron X-ray fluorescence nanoimaging of eight impact features in aerogel

    E-Print Network [OSTI]

    Nittler, Larry R.

    -ray fluorescence nanoimaging of eight impact features in aerogel Alexandre S. SIMIONOVICI1* , Laurence LEMELLE2

  3. Photonic Calibration for Fluorescence Microscopy Ian T. Young

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    ABSTRACT Based upon a collection of compact LEDs (light-emitting diodes) and a compact photodiode, we have is also turned on but for illustration purposes only. 1.1 The emission path Low-power light-emitting diodes (LEDs) are available in a number of colors. An LED color mimics the emission spectrum

  4. Optimized scalable stack of fluorescent solar concentrator systems with bifacial silicon solar cells

    SciTech Connect (OSTI)

    Martínez Díez, Ana Luisa, E-mail: a.martinez@itma.es [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain); Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Gutmann, Johannes; Posdziech, Janina; Rist, Tim; Goldschmidt, Jan Christoph [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Plaza, David Gómez [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain)

    2014-10-21

    In this paper, we present a concentrator system based on a stack of fluorescent concentrators (FCs) and a bifacial solar cell. Coupling bifacial solar cells to a stack of FCs increases the performance of the system and preserves its efficiency when scaled. We used an approach to optimize a fluorescent solar concentrator system design based on a stack of multiple fluorescent concentrators (FC). Seven individual fluorescent collectors (20 mm×20 mm×2 mm) were realized by in-situ polymerization and optically characterized in regard to their ability to guide light to the edges. Then, an optimization procedure based on the experimental data of the individual FCs was carried out to determine the stack configuration that maximizes the total number of photons leaving edges. Finally, two fluorescent concentrator systems were realized by attaching bifacial silicon solar cells to the optimized FC stacks: a conventional system, where FC were attached to one side of the solar cell as a reference, and the proposed bifacial configuration. It was found that for the same overall FC area, the bifacial configuration increases the short-circuit current by a factor of 2.2, which is also in agreement with theoretical considerations.

  5. A fluorescence-based method for rapid and direct determination of polybrominated diphenyl ethers in water

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shan, Huimei; Liu, Chongxuan; Wang, Zheming; Ma, Teng; Shang, Jianying; Pan, Duoqiang

    2015-01-01

    A new method was developed for rapid and direct measurement of polybrominated diphenyl ethers (PBDEs) in aqueous samples using fluorescence spectroscopy. The fluorescence spectra of tri- to deca-BDE (BDE 28, 47, 99, 153, 190, and 209) commonly found in environment were measured at variable emission and excitation wavelengths. The results revealed that the PBDEs have distinct fluorescence spectral profiles and peak positions that can be exploited to identify these species and determine their concentrations in aqueous solutions. The detection limits as determined in deionized water spiked with PBDEs are 1.71-5.82 ng/L for BDE 28, BDE 47, BDE 190, and BDEmore »209 and 45.55–69.95 ng/L for BDE 99 and BDE 153. The effects of environmental variables including pH, humic substance, and groundwater chemical composition on PBDEs measurements were also investigated. These environmental variables affected fluorescence intensity, but their effect can be corrected through linear additivity and separation of spectral signal contribution. Compared with conventional GC-based analytical methods, the fluorescence spectroscopy method is more efficient as it only uses a small amount of samples (2-4 mL), avoids lengthy complicated concentration and extraction steps, and has a low detection limit of a few ng/L.« less

  6. A fluorescence-based method for rapid and direct determination of polybrominated diphenyl ethers in water

    SciTech Connect (OSTI)

    Shan, Huimei; Liu, Chongxuan; Wang, Zheming; Ma, Teng; Shang, Jianying; Pan, Duoqiang

    2015-01-01

    A new method was developed for rapid and direct measurement of polybrominated diphenyl ethers (PBDEs) in aqueous samples using fluorescence spectroscopy. The fluorescence spectra of tri- to deca-BDE (BDE 28, 47, 99, 153, 190, and 209) commonly found in environment were measured at variable emission and excitation wavelengths. The results revealed that the PBDEs have distinct fluorescence spectral profiles and peak positions that can be exploited to identify these species and determine their concentrations in aqueous solutions. The detection limits as determined in deionized water spiked with PBDEs are 1.71-5.82 ng/L for BDE 28, BDE 47, BDE 190, and BDE 209 and 45.55–69.95 ng/L for BDE 99 and BDE 153. The effects of environmental variables including pH, humic substance, and groundwater chemical composition on PBDEs measurements were also investigated. These environmental variables affected fluorescence intensity, but their effect can be corrected through linear additivity and separation of spectral signal contribution. Compared with conventional GC-based analytical methods, the fluorescence spectroscopy method is more efficient as it only uses a small amount of samples (2-4 mL), avoids lengthy complicated concentration and extraction steps, and has a low detection limit of a few ng/L.

  7. A Fluorescence-Based Method for Rapid and Direct Determination of Polybrominated Diphenyl Ethers in Water

    SciTech Connect (OSTI)

    Shan, Huimei [China Univ. of Geosciences, Wuhan (China). Lab of Basin and Wetland Eco-Restoration; Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Chongxuan [China Univ. of Geosciences, Wuhan (China). Lab of Basin and Wetland Eco-Restoration; Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Zheming [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ma, Teng [China Univ. of Geosciences, Wuhan (China). Lab of Basin and Wetland Eco-Restoration and State Key Lab. of Biogeology and Environmental Geology; Shang, Jianying [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pan, Duoqiang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-01-01

    A new method was developed for rapid and direct measurement of polybrominated diphenyl ethers (PBDEs) in aqueous samples using fluorescence spectroscopy. The fluorescence spectra of tri- to deca-BDE (BDE 28, 47, 99, 153, 190, and 209) commonly found in environment were measured at variable emission and excitation wavelengths. The results revealed that the PBDEs have distinct fluorescence spectral profiles and peak positions that can be exploited to identify these species and determine their concentrations in aqueous solutions. The detection limits as determined in deionized water spiked with PBDEs are 1.71-5.82 ng/L for BDE 28, BDE 47, BDE 190, and BDE 209 and 45.55–69.95 ng/L for BDE 99 and BDE 153. The effects of environmental variables including pH, humic substance, and groundwater chemical composition on PBDEs measurements were also investigated. These environmental variables affected fluorescence intensity, but their effect can be corrected through linear additivity and separation of spectral signal contribution. Compared with conventional GC-based analytical methods, the fluorescence spectroscopy method is more efficient as it only uses a small amount of samples (2-4 mL), avoids lengthy complicated concentration and extraction steps, and has a low detection limit of a few ng/L.

  8. Average M shell fluorescence yields for elements with 70?Z?92

    SciTech Connect (OSTI)

    Kahoul, A.; Deghfel, B.; Aylikci, V.; Aylikci, N. K.; Nekkab, M.

    2015-03-30

    The theoretical, experimental and analytical methods for the calculation of average M-shell fluorescence yield (?{sup ¯}{sub M}) of different elements are very important because of the large number of their applications in various areas of physical chemistry and medical research. In this paper, the bulk of the average M-shell fluorescence yield measurements reported in the literature, covering the period 1955 to 2005 are interpolated by using an analytical function to deduce the empirical average M-shell fluorescence yield in the atomic range of 70?Z?92. The results were compared with the theoretical and fitted values reported by other authors. Reasonable agreement was typically obtained between our result and other works.

  9. Intense Internal and External Fluorescence as Solar Cells Approach the Shockley-Queisser Efficiency Limit

    E-Print Network [OSTI]

    Miller, Owen D; Kurtz, Sarah R

    2012-01-01

    Absorbed sunlight in a solar cell produces electrons and holes. But, at the open circuit condition, the carriers have no place to go. They build up in density and, ideally, they emit external fluorescence that exactly balances the incoming sunlight. Any additional non-radiative recombination impairs the carrier density buildup, limiting the open-circuit voltage. At open-circuit, efficient external fluorescence is an indicator of low internal optical losses. Thus efficient external fluorescence is, counter-intuitively, a necessity for approaching the Shockley-Queisser efficiency limit. A great Solar Cell also needs to be a great Light Emitting Diode. Owing to the narrow escape cone for light, efficient external emission requires repeated attempts, and demands an internal luminescence efficiency >>90%.

  10. Fluorescence measurements for evaluating the application of multivariate analysis techniques to optically thick environments.

    SciTech Connect (OSTI)

    Reichardt, Thomas A.; Timlin, Jerilyn Ann; Jones, Howland D. T.; Sickafoose, Shane M.; Schmitt, Randal L.

    2010-09-01

    Laser-induced fluorescence measurements of cuvette-contained laser dye mixtures are made for evaluation of multivariate analysis techniques to optically thick environments. Nine mixtures of Coumarin 500 and Rhodamine 610 are analyzed, as well as the pure dyes. For each sample, the cuvette is positioned on a two-axis translation stage to allow the interrogation at different spatial locations, allowing the examination of both primary (absorption of the laser light) and secondary (absorption of the fluorescence) inner filter effects. In addition to these expected inner filter effects, we find evidence that a portion of the absorbed fluorescence is re-emitted. A total of 688 spectra are acquired for the evaluation of multivariate analysis approaches to account for nonlinear effects.

  11. Demonstration of x-ray fluorescence imaging of a high-energy-density plasma

    SciTech Connect (OSTI)

    MacDonald, M. J., E-mail: macdonm@umich.edu; Gamboa, E. J. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Keiter, P. A.; Fein, J. R.; Klein, S. R.; Kuranz, C. C.; LeFevre, H. J.; Manuel, M. J.-E.; Wan, W. C.; Drake, R. P. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Montgomery, D. S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Biener, M. M.; Fournier, K. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Streit, J. [Schafer Corporation, Livermore, California 94551 (United States)

    2014-11-15

    Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-? x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

  12. Quantitative measurement of binary liquid distributions using multiple-tracer x-ray fluorescence and radiography

    SciTech Connect (OSTI)

    Halls, Benjamin R.; Meyer, Terrence R.; Kastengren, Alan L.

    2015-01-01

    The complex geometry and large index-of-refraction gradients that occur near the point of impingement of binary liquid jets present a challenging environment for optical interrogation. A simultaneous quadruple-tracer x-ray fluorescence and line-of-sight radiography technique is proposed as a means of distinguishing and quantifying individual liquid component distributions prior to, during, and after jet impact. Two different pairs of fluorescence tracers are seeded into each liquid stream to maximize their attenuation ratio for reabsorption correction and differentiation of the two fluids during mixing. This approach for instantaneous correction of x-ray fluorescence reabsorption is compared with a more time-intensive approach of using stereographic reconstruction of x-ray attenuation along multiple lines of sight. The proposed methodology addresses the need for a quantitative measurement technique capable of interrogating optically complex, near-field liquid distributions in many mixing systems of practical interest involving two or more liquid streams.

  13. Quantitative measurement of binary liquid distributions using multiple-tracer x-ray fluorescence and radiography

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Halls, Benjamin R.; Meyer, Terrence R.; Kastengren, Alan L.

    2015-01-23

    The complex geometry and large index-of-refraction gradients that occur near the point of impingement of binary liquid jets present a challenging environment for optical interrogation. A simultaneous quadruple-tracer x-ray fluorescence and line-of-sight radiography technique is proposed as a means of distinguishing and quantifying individual liquid component distributions prior to, during, and after jet impact. Two different pairs of fluorescence tracers are seeded into each liquid stream to maximize their attenuation ratio for reabsorption correction and differentiation of the two fluids during mixing. This approach for instantaneous correction of x-ray fluorescence reabsorption is compared with a more time-intensive approach of usingmore »stereographic reconstruction of x-ray attenuation along multiple lines of sight. The proposed methodology addresses the need for a quantitative measurement technique capable of interrogating optically complex, near-field liquid distributions in many mixing systems of practical interest involving two or more liquid streams.« less

  14. Charge Transfer Fluorescence and 34 nm Exciton Diffusion Length in Polymers with Electron Acceptor End Traps

    SciTech Connect (OSTI)

    Zaikowski, L.; Mauro, G.; Bird, M.; Karten, B.; Asaoka, S.; Wu, Q.; Cook, A. R.; Miller, J.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are as large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. The efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.

  15. A portable time-domain LED fluorimeter for nanosecond fluorescence lifetime measurements

    SciTech Connect (OSTI)

    Wang, Hongtao; Salthouse, Christopher D., E-mail: salthouse@ecs.umass.edu [Electrical and Computer Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Qi, Ying; Mountziaris, T. J. [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States) [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Chemical Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

    2014-05-15

    Fluorescence lifetime measurements are becoming increasingly important in chemical and biological research. Time-domain lifetime measurements offer fluorescence multiplexing and improved handling of interferers compared with the frequency-domain technique. In this paper, an all solid-state, filterless, and highly portable light-emitting-diode based time-domain fluorimeter (LED TDF) is reported for the measurement of nanosecond fluorescence lifetimes. LED based excitation provides more wavelengths options compared to laser diode based excitation, but the excitation is less effective due to the uncollimated beam, less optical power, and longer latency in state transition. Pulse triggering and pre-bias techniques were implemented in our LED TDF to improve the peak optical power to over 100 mW. The proposed pulsing circuit achieved an excitation light fall time of less than 2 ns. Electrical resetting technique realized a time-gated photo-detector to remove the interference of the excitation light with fluorescence. These techniques allow the LED fluorimeter to accurately measure the fluorescence lifetime of fluorescein down to concentration of 0.5 ?M. In addition, all filters required in traditional instruments are eliminated for the non-attenuated excitation/emission light power. These achievements make the reported device attractive to biochemical laboratories seeking for highly portable lifetime detection devices for developing sensors based on fluorescence lifetime changes. The device was initially validated by measuring the lifetimes of three commercial fluorophores and comparing them with reported lifetime data. It was subsequently used to characterize a ZnSe quantum dot based DNA sensor.

  16. Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zaikowski, Lori; Mauro, Gina; Bird, Matthew; Karten, Brianne; Asaoka, Sadayuki; Wu, Qin; Cook, Andrew R.; Miller, John R.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are asmore »large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.« less

  17. Method for detecting binding events using micro-X-ray fluorescence spectrometry

    DOE Patents [OSTI]

    Warner, Benjamin P. (Los Alamos, NM); Havrilla, George J. (Los Alamos, NM); Mann, Grace (Hong Kong, HK)

    2010-12-28

    Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

  18. Nanodiamonds with silicon vacancy defects for non-toxic photostable fluorescent labeling of neural precursor cells

    E-Print Network [OSTI]

    Merson, Tobias D; Aharonovich, Igor; Turbic, Alisa; Kilpatrick, Trevor J; Turnley, Ann M

    2013-01-01

    Nanodiamonds (NDs) containing silicon vacancy (SiV) defects were evaluated as a potential biomarker for the labeling and fluorescent imaging of neural precursor cells (NPCs). SiV-containing NDs were synthesized using chemical vapor deposition and silicon ion implantation. Spectrally, SiV-containing NDs exhibited extremely stable fluorescence and narrow bandwidth emission with an excellent signal to noise ratio exceeding that of NDs containing nitrogen-vacancy (NV) centers. NPCs labeled with NDs exhibited normal cell viability and proliferative properties consistent with biocompatibility. We conclude that SiVcontaining NDs are a promising biomedical research tool for cellular labeling and optical imaging in stem cell research.

  19. Fast repetition rate (FRR) fluorometer and method for measuring fluorescence and photosynthetic parameters

    DOE Patents [OSTI]

    Kolber, Z.; Falkowski, P.

    1995-06-20

    A fast repetition rate fluorometer device and method for measuring in vivo fluorescence of phytoplankton or higher plants chlorophyll and photosynthetic parameters of phytoplankton or higher plants is revealed. The phytoplankton or higher plants are illuminated with a series of fast repetition rate excitation flashes effective to bring about and measure resultant changes in fluorescence yield of their Photosystem II. The series of fast repetition rate excitation flashes has a predetermined energy per flash and a rate greater than 10,000 Hz. Also, disclosed is a flasher circuit for producing the series of fast repetition rate flashes. 14 figs.

  20. High efficiency and brightness fluorescent organic light emitting diode by triplet-triplet fusion

    DOE Patents [OSTI]

    Forrest, Stephen; Zhang, Yifan

    2015-02-10

    A first device is provided. The first device further comprises an organic light emitting device. The organic light emitting device further comprises an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer may include an organic host compound and at least one organic emitting compound capable of fluorescent emission at room temperature. Various configurations are described for providing a range of current densities in which T-T fusion dominates over S-T annihilation, leading to very high efficiency fluorescent OLEDs.

  1. Measurement of Pressure Dependent Fluorescence Yield of Air: Calibration Factor for UHECR Detectors

    SciTech Connect (OSTI)

    Belz, J.W.; Burt, G.W.; Cao, Z.; Chang, F.Y.; Chen, C.C.; Chen, C.W.; Chen, P.; Field, C.; Findlay, J.; Huntemeyer, Petra; Huang, M.A.; Hwang, W.-Y.P.; Iverson, R.; Jones, B.F.; Jui, C.C.H.; Kirn, M.; Lin, G.-L.; Loh, E.C.; Maestas, M.M.; Manago, N.; Martens, K.; /Montana U. /Utah U. /Taiwan, Natl. Taiwan U. /SLAC /Rutgers U., Piscataway

    2005-07-06

    In a test experiment at the Final Focus Test Beam of the Stanford Linear Accelerator Center, the fluorescence yield of 28.5 GeV electrons in air and nitrogen was measured. The measured photon yields between 300 and 400 nm at 1 atm and 29 C are Y(760 Torr){sup air} = 4.42 {+-} 0.73 and Y(760 Torr){sup N{sub 2}} = 29.2 {+-} 4.8 photons per electron per meter. Assuming that the fluorescence yield is proportional to the energy deposition of a charged particle traveling through air, good agreement with measurements at lower particle energies is observed.

  2. Flooding and Phytophthora cinnamomi: Effects on photosynthesis and chlorophyll fluorescence in shoots of non-grafted Persea americana

    E-Print Network [OSTI]

    Flooding and Phytophthora cinnamomi: Effects on photosynthesis and chlorophyll fluorescence: Phytophthora Avocado Fluorescence Gas exchange Flooding Losses in the production of avocado (Persea americana in tree-dieback and eventual tree death. Avocado is also a flood-sensitive species and flooding

  3. Proton Pathways in Green Fluorescence Protein Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel

    E-Print Network [OSTI]

    Agmon, Noam

    Proton Pathways in Green Fluorescence Protein Noam Agmon Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel ABSTRACT Proton pathways in green fluorescent protein pathway exists from the active site to the protein surface, controlled by a threonine switch. A proton

  4. Three-Dimensional Fluorescence Spectra of Thermally Stressed Commercial Jet A-1 Aviation Fuel in the Autoxidative Regime

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Three-Dimensional Fluorescence Spectra of Thermally Stressed Commercial Jet A-1 Aviation Fuel: In this study, the thermal oxidative stability of a kerosene-type Jet A-1 commercial aviation fuel has been investigated using a three-dimensional (3D) excitation/emission matrix fluorescence (EEMF) method. The fuel

  5. Inferred influence of nutrient availability on the relationship between Sun-induced chlorophyll fluorescence and incident irradiance in the

    E-Print Network [OSTI]

    Kelley, Dan

    fluorescence and incident irradiance in the Bering Sea Christina Schallenberg,1 Marlon R. Lewis,1 Dan E. Kelley fluorescence and incident solar irradiance as a potential diagnostic of the nutritional status of phytoplankton normalized to the absorption of light by pigments were analyzed as a function of irradiance to describe

  6. Single-Molecule Fluorescence Studies of Protein Folding and Conformational Xavier Michalet,* Shimon Weiss, and Marcus Jager*

    E-Print Network [OSTI]

    Michalet, Xavier

    Single-Molecule Fluorescence Studies of Protein Folding and Conformational Dynamics Xavier Michalet. Single-Molecule Fluorescence Studies of Protein Folding and Conformations at Equilibrium 1796 4-Molecule Protein Folding under Nonequilibrium Conditions 1808 6. Conclusion 1809 7. Acknowledgments 1810 8

  7. A Highly Selective Turn-On Colorimetric, Red Fluorescent Sensor for Detecting Mobile Zinc in Living Cells

    E-Print Network [OSTI]

    Du, Pingwu

    We describe ZRL1, a turn-on colorimetric and red fluorescent zinc ion sensor. The Zn2+-promoted ring opening of the rhodamine spirolactam ring in ZRL1 evokes a 220-fold fluorescence turn-on response. In aqueous media, ZRL1 ...

  8. Modeling green fluorescent protein transcription, translation and modification as a method to obtain NF-kappaB activation profiles 

    E-Print Network [OSTI]

    Laible, Allyson Marie

    2009-05-15

    that fluorescence increases up to 24 hours after an initial delay of approximately four hours. The fluorescence data was also used to develop a model describing significant events leading to NF-?B activation and GFP expression. In addition, a model describing...

  9. Comparison of Air Fluorescence and Ionization Measurements of E.M. Shower Depth Profiles: Test of a UHECR Detector Technique

    SciTech Connect (OSTI)

    Belz, J.; Cao, Z.; Huentemeyer, P.; Jui, C.C.H.; Martens, K.; Matthews, J.; Maestas, M.; Smith, J.; Sokolsky, P.; Springer, R.W.; Thomas, J.; Thomas, S.; /Utah U.; Chen,P.; Field, Clive; Hast, C.; Iverson, R.; Ng, J.S.T.; Odian, A.; Reil, K.; Vincke, H.; Walz, D.; /SLAC /Montana U. /Rutgers U., Piscataway /Taiwan, Natl. Taiwan U.; ,

    2005-10-07

    Measurements are reported on the fluorescence of air as a function of depth in electromagnetic showers initiated by bunches of 28.5 GeV electrons. The light yield is compared with the expected and observed depth profiles of ionization in the showers. It validates the use of atmospheric fluorescence profiles in measuring ultra high energy cosmic rays.

  10. Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 20692076 PLANAR LASER-INDUCED FLUORESCENCE IMAGING OF CREVICE

    E-Print Network [OSTI]

    Long, Marshall B.

    with lower octane ratings were shown to enhance flame penetration due to their increased reactivity-induced fluorescence (PLIF) from iso-octane/n-heptane fuel blends doped with 3-pentanone. The fluorescence was imaged

  11. Low-noise CMOS Fluorescence Sensor David Sander, Marc Dandin, Honghao Ji, Nicole Nelson, Pamela Abshire

    E-Print Network [OSTI]

    Maryland at College Park, University of

    Low-noise CMOS Fluorescence Sensor David Sander, Marc Dandin, Honghao Ji, Nicole Nelson, Pamela a differential read- out architecture in order to reduce the overall noise figure. The circuit has been fabricated in a commercially available 0.5 µm CMOS technology. Preliminary results show that the reset noise

  12. Fluorescence Stopped-flow Studies of Single Turnover Kinetics of E. coli RecBCD Helicase-

    E-Print Network [OSTI]

    Lohman, Timothy M.

    reserved. Keywords: FRET; helicase; motor; recombination; fluorescence*Corresponding author Introduction DNA helicases are motor proteins that use nucleoside triphosphate (NTP) binding and hydrolysis; NLLS, non-linear least squares; b-ME, b-mercapto- ethanol. doi:10.1016/j.jmb.2004.04.009 J. Mol. Biol

  13. Measurement of air and nitrogen fluorescence light yields induced by electron beam for UHECR experiments

    E-Print Network [OSTI]

    P. Colin; A. Chukanov; V. Grebenyuk; D. Naumov; P. Nedelec; Y. Nefedov; A. Onofre; S. Porokhovoi; B. Sabirov; L. Tkatchev

    2006-12-04

    Most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, EUSO, TUS,...) use air fluorescence to detect and measure extensive air showers (EAS). The precise knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the reconstruction of UHECR. The MACFLY - Measurement of Air Cherenkov and Fluorescence Light Yield - experiment has been designed to perform such FLY measurements. In this paper we will present the results of FLY in the 290-440 nm wavelength range for dry air and pure nitrogen, both excited by electrons with energy of 1.5 MeV, 20 GeV and 50 GeV. The experiment uses a 90Sr radioactive source for low energy measurement and a CERN SPS electron beam for high energy. We find that the FLY is proportional to the deposited energy (E_d) in the gas and we show that the air fluorescence properties remain constant independently of the electron energy. At the reference point: atmospheric dry air at 1013 hPa and 23C, the ratio FLY/E_d=17.6 photon/MeV with a systematic error of 13.2%.

  14. Fluorescent porous silicon biological probes with high quantum efficiency and stability

    E-Print Network [OSTI]

    Lin, Lih Y.

    -toxic alternative to organic dyes or cadmium-containing quantum dots for imaging and sensing applications. Ellenbogen, and J. M. Olson, "Tumor paint: a chlorotoxin:Cy5.5 bioconjugate for intraoperative visualization-Jaricot, R. Nitschke, and T. Nann, "Quantum dots versus organic dyes as fluorescent labels," Nat. Methods 5

  15. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Woehl, Taylor J.; Kashyap, Sanjay; Firlar, Emre; Perez-Gonzalez, Teresa; Faivre, Damien; Trubitsyn, Denis; Bazylinski, Dennis A.; Prozorov, Tanya

    2014-10-31

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment. Here we present a correlative scanning TEM (STEM) and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid using an in situ fluid cell TEM holder. Fluorescently labeled cells were immobilized on microchip windowmore »surfaces and visualized in a fluid cell with STEM, followed by correlative fluorescence imaging to verify their membrane integrity. Notably, the post-STEM fluorescence imaging indicated that the bacterial cell wall membrane did not sustain radiation damage during STEM imaging at low electron dose conditions. We investigated the effects of radiation damage and sample preparation on the bacteria viability and found that approximately 50% of the bacterial membranes remained intact after an hour in the fluid cell, decreasing to ~30% after two hours. These results represent a first step toward in vivo studies of magnetite biomineralization in magnetotactic bacteria.« less

  16. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

    SciTech Connect (OSTI)

    Woehl, Taylor J.; Kashyap, Sanjay; Firlar, Emre; Perez-Gonzalez, Teresa; Faivre, Damien; Trubitsyn, Denis; Bazylinski, Dennis A.; Prozorov, Tanya

    2014-10-31

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment. Here we present a correlative scanning TEM (STEM) and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid using an in situ fluid cell TEM holder. Fluorescently labeled cells were immobilized on microchip window surfaces and visualized in a fluid cell with STEM, followed by correlative fluorescence imaging to verify their membrane integrity. Notably, the post-STEM fluorescence imaging indicated that the bacterial cell wall membrane did not sustain radiation damage during STEM imaging at low electron dose conditions. We investigated the effects of radiation damage and sample preparation on the bacteria viability and found that approximately 50% of the bacterial membranes remained intact after an hour in the fluid cell, decreasing to ~30% after two hours. These results represent a first step toward in vivo studies of magnetite biomineralization in magnetotactic bacteria.

  17. Laser-excited atomic fluorescence spectrometry in a graphite furnace with an

    E-Print Network [OSTI]

    Michel, Robert G.

    Laser-excited atomic fluorescence spectrometry in a graphite furnace with an optical parametric oscillator laser for sequential multi-element determination of cadmium, cobalt, lead, manganese and thallium, for the ® rst time, that solid-state lasers required for analysis (ml or mg) and the technique has direct based

  18. Characterizing point spread functions of two-photon fluorescence microscopy in turbid medium

    E-Print Network [OSTI]

    So, Peter

    - medical imaging. Among its advantages is the enhanced depth pen- etration permitted by fluorescence environment often found in tissue. A full characterization of the two-photon PSFs of a water and oil immersion to depths of about 100 (oil) and 200 m (water), the presence of scatterers (up to 2% Liposyn III) does

  19. X-ray fluorescent lines from the Compton-thick AGN in M5

    E-Print Network [OSTI]

    Xu, Weiwei; Gou, Lijun; Liu, Jiren

    2015-01-01

    The cold disk/torus gas surrounding AGN emits fluorescent lines when irradiated by hard X-ray photons. The fluorescent lines of elements other than Fe and Ni are rarely detected due to their relative faintness. We report the detection of K$\\alpha$ lines of neutral Si, S, Ar, Ca, Cr, and Mn, along with the prominent Fe K$\\alpha$, Fe K$\\beta$, and Ni K$\\alpha$ lines, from the deep Chandra observation of the low-luminosity Compton-thick AGN in M51. The Si K$\\alpha$ line at 1.74 keV is detected at $\\sim3\\sigma$, the other fluorescent lines have a significance between 2 and 2.5 $\\sigma$, while the Cr line has a significance of $\\sim1.5\\sigma$. These faint fluorescent lines are made observable due to the heavy obscuration of the intrinsic spectrum of M51, which is revealed by Nustar observation above 10 keV. The hard X-ray continuum of M51 from Chandra and Nustar can be fitted with a power-law spectrum with an index of 1.8, reprocessed by a torus with an equatorial column density of $N_{\\rm H}\\sim7\\times10^{24}$ cm...

  20. Fluorescence from a gelatin-based film containing isolated and orientated single-walled carbon nanotubes

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Fluorescence from a gelatin-based film containing isolated and orientated single-walled carbon a technique to fabricate a gelatin thin film that contains orientated and individually dispersed single with gelatin, and the gelatin-SWNTs solution was spread over a SiO2 substrate by sliding a wire-bar uniformly

  1. Use of handheld X-ray fluorescence spectrometry units for identification of arsenic in treated wood

    E-Print Network [OSTI]

    Florida, University of

    Use of handheld X-ray fluorescence spectrometry units for identification of arsenic in treated wood within preservative-treated wood. Abstract The objective of this study was to evaluate the performance of handheld XRF analyzers on wood that has been treated with a preservative containing arsenic. Experiments

  2. A Fast and Selective Near-Infrared Fluorescent Sensor for Multicolor Imaging of Biological Nitroxyl (HNO)

    E-Print Network [OSTI]

    Wrobel, Alexandra T.

    The first near-infrared fluorescent turn-on sensor for the detection of nitroxyl (HNO), the one-electron reduced form of nitric oxide (NO), is reported. The new copper-based probe, CuDHX1, contains a dihydroxanthene (DHX) ...

  3. Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice Surfaces

    E-Print Network [OSTI]

    Wettlaufer, John S.

    Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice ABSTRACT Many organisms are protected from freezing by the presence of extracellular antifreeze proteins (AFPs), which bind to ice, modify its morphology, and prevent its further growth. These proteins have

  4. Intercellular trafficking of a KNOTTED1 green fluorescent protein fusion in the leaf and

    E-Print Network [OSTI]

    Jackson, David

    Intercellular trafficking of a KNOTTED1 green fluorescent protein fusion in the leaf and shoot Jackson¶ Cold Spring Harbor Laboratory, Watson School of Biological Sciences, 1 Bungtown Road, Cold Spring between epidermal cells of Arabidopsis and onion. When expressed in vivo, the GFP KN1 fusion trafficked

  5. Filter-fluorescer measurement of low-voltage simulator x-ray energy spectra

    SciTech Connect (OSTI)

    Baldwin, G.T.; Craven, R.E.

    1986-01-01

    X-ray energy spectra of the Maxwell Laboratories MBS and Physics International Pulserad 737 were measured using an eight-channel filter-fluorescer array. The PHOSCAT computer code was used to calculate channel response functions, and the UFO code to unfold spectrum.

  6. Laser induced fluorescence of the ferroelectric plasma source assisted hollow anode discharge

    E-Print Network [OSTI]

    the plasma sources described in Refs. 4 and 11­13, where either thermionic cathode or magnetron or arc plasmaLaser induced fluorescence of the ferroelectric plasma source assisted hollow anode discharge V online 20 November 2009 Parameters of the plasma produced by a ferroelectric plasma source FPS assisted

  7. Highly efficient non-doped fluorescent OLEDs based on aggregation-induced emission emitters

    E-Print Network [OSTI]

    26 Highly efficient non-doped fluorescent OLEDs based on aggregation-induced emission emitters quenches light emission due to strong intermolecular - interaction, a notorious effect known as aggregation as emitters will be present. The TPE derivatives show aggregation-induced emission (AIE) characteristics, i

  8. Fast-scanning two-photon fluorescence imaging based on a microelectromechanical systems two-

    E-Print Network [OSTI]

    Schnitzer, Mark

    on microelectromechanical systems (MEMS) scanners. Single crystalline silicon scanning mirrors that are 0.75 mm 0.75 mm miniaturized. We report the use of microelectromechanical sys- tems (MEMS) scanners for filling this nicheFast-scanning two-photon fluorescence imaging based on a microelectromechanical systems two

  9. Single-molecule protein folding: Diffusion fluorescence resonance energy transfer studies

    E-Print Network [OSTI]

    Croquette, Vincent

    Single-molecule protein folding: Diffusion fluorescence resonance energy transfer studies for protein folding studies and has been extensively stud- ied, both experimentally (at the ensemble level concentration. It is shown that new infor- mation about different aspects of the protein folding reaction can

  10. Fluorescence technique for on-line monitoring of state of hydrogen-producing microorganisms

    DOE Patents [OSTI]

    Seibert, Michael (Lakewood, CO); Makarova, Valeriya (Golden, CO); Tsygankov, Anatoly A. (Pushchino, RU); Rubin, Andrew B. (Moscow, RU)

    2007-06-12

    In situ fluorescence method to monitor state of sulfur-deprived algal culture's ability to produce H.sub.2 under sulfur depletion, comprising: a) providing sulfur-deprived algal culture; b) illuminating culture; c) measuring onset of H.sub.2 percentage in produced gas phase at multiple times to ascertain point immediately after anerobiosis to obtain H.sub.2 data as function of time; and d) determining any abrupt change in three in situ fluorescence parameters; i) increase in F.sub.t (steady-state level of chlorophyll fluorescence in light adapted cells); ii) decrease in F.sub.m', (maximal saturating light induced fluorescence level in light adapted cells); and iii) decrease in .DELTA.F/F.sub.m'=(F.sub.m'-F.sub.t)/F.sub.m' (calculated photochemical activity of photosystem II (PSII) signaling full reduction of plastoquinone pool between PSII and PSI, which indicates start of anaerobic conditions that induces synthesis of hydrogenase enzyme for subsequent H.sub.2 production that signal oxidation of plastoquinone pool asmain factor to regulate H.sub.2 under sulfur depletion.

  11. Methods in Molecular Biology: Protocols in Confocal microscopy Chapter 17. Live imaging of green fluorescent protein

    E-Print Network [OSTI]

    Haseloff, Jim

    , an accessory protein that accepts energy from aequorin and re-emits it as green light [8] . GFP is an extremelyMethods in Molecular Biology: Protocols in Confocal microscopy Chapter 17. Live imaging of green biologists won the lottery when it was demonstrated that green fluorescent protein (GFP), a kind gift from

  12. Adaptive finite element methods for forward modeling in fluorescence enhanced frequency domain optical

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    Adaptive finite element methods for forward modeling in fluorescence enhanced frequency domain for Subsurface Modeling, ICES, University of Texas, Austin, TX Abstract: An adaptive finite element scheme the boundary measurements of photon energy resulting from the tissue stimulation via infrared light sources

  13. ADAPTIVE FINITE ELEMENT METHODS FOR FLUORESCENCE ENHANCED FREQUENCY DOMAIN OPTICAL TOMOGRAPHY: FORWARD IMAGING PROBLEM

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    error estimates for adaptive mesh refinement to optimally model the strongly graded light distributionADAPTIVE FINITE ELEMENT METHODS FOR FLUORESCENCE ENHANCED FREQUENCY DOMAIN OPTICAL TOMOGRAPHY Modeling, ICES, University of Texas at Austin, TX ABSTRACT In this contribution we introduce adaptive

  14. Simultaneous cryo X-ray ptychographic and fluorescence microscopy of green algae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Deng, Junjing; Vine, David J.; Chen, Si; Nashed, Youssef S. G.; Jin, Qiaoling; Phillips, Nicholas W.; Peterka, Tom; Ross, Rob; Vogt, Stefan; Jacobsen, Chris J.

    2015-02-24

    Trace metals play important roles in normal and in disease-causing biological functions. X-ray fluorescence microscopy reveals trace elements with no dependence on binding affinities (unlike with visible light fluorophores) and with improved sensitivity relative to electron probes. However, X-ray fluorescence is not very sensitive for showing the light elements that comprise the majority of cellular material. Here we show that X-ray ptychography can be combined with fluorescence to image both cellular structure and trace element distribution in frozen-hydrated cells at cryogenic temperatures, with high structural and chemical fidelity. Ptychographic reconstruction algorithms deliver phase and absorption contrast images at a resolutionmore »beyond that of the illuminating lens or beam size. Using 5.2-keV X-rays, we have obtained sub–30-nm resolution structural images and ~90-nm–resolution fluorescence images of several elements in frozen-hydrated green algae. This combined approach offers a way to study the role of trace elements in their structural context.« less

  15. HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage

    E-Print Network [OSTI]

    HF Multiresonant Electronic Ballast for Fluorescent Lamps with Constant Filament Preheat Voltage resonance arrangement that acts as a current source. During warm up the filaments are driven by a secondary the filament and shorts out the voltage across the lamp. Simulation and experimental results suggest

  16. Development of an ion drift chamber for Laser Induced Fluorescence studies 

    E-Print Network [OSTI]

    Cain, Benjamin J

    1998-01-01

    The use of Laser Induced Fluorescence to image ions in a gas has been proposed for a possible new type of subatomic particle detector.1 As a means to investigate this idea, an ion drift chamber has been developed that produces a collimated beam...

  17. Estimation of membrane lateral pressure in living cells by means of multidimensional confocal fluorescence microscopy

    E-Print Network [OSTI]

    Rosso, Lula

    -labeled phospholipids. We report an alternative strategy based on the intramolecular fluorescence energy transfer Kensington Campus, London SW7 2AZ, UK Considerable pressures (many tens of atmospheres) are generated within between the energy necessary to keep the hydrocarbon chains away from water and the energy generated

  18. A Microfluidic Device for Temporally Controlled Gene Expression and Long-Term Fluorescent Imaging in

    E-Print Network [OSTI]

    Siggia, Eric

    A Microfluidic Device for Temporally Controlled Gene Expression and Long-Term Fluorescent Imaging of the cell cycle. Over the past ten years, microfluidic techniques in cell biology have emerged that allow a microfluidic flow cell to grow Saccharomyces Cerevisiae for more than 8 generations (

  19. Spectral properties of a fluorescing molecule within a spherical metallic nanocavityy

    E-Print Network [OSTI]

    Enderlein, Jörg

    ¨lich, Germany. E-mail: j.enderlein@fz-juelich.de Received 15th January 2002, Accepted 14th February 2002 First-field interaction between dye and cavity. Both effects can largely outweigh the fluorescence losses caused by energy of the excitation light; (ii) energy transfer of the molecule's excited state energy to the metal; (iii) energy

  20. Fluorescence Lifetime of Emitters with Broad Homogeneous Linewidths Modified in Opal Photonic Crystals

    E-Print Network [OSTI]

    Vos, Willem L.

    Fluorescence Lifetime of Emitters with Broad Homogeneous Linewidths Modified in Opal Photonic, 2008 We have investigated the dynamics of spontaneous emission from dye molecules embedded in opal optical frequency and crystal lattice parameter of the polystyrene opals. Due to the broad homogeneous

  1. Understanding Blue-to-Red Conversion in Monomeric Fluorescent Timers and Hydrolytic Degradation of Their

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    Understanding Blue-to-Red Conversion in Monomeric Fluorescent Timers and Hydrolytic Degradation phenolate oxygen and the side chain hydroxyl of Ser146. In Blue102, a bulky side chain of Ile146 precludes-FT and Blue102 structures revealed hydrolytic degradation of the chromophores. In Fast-FT, chromophore

  2. Iron Fluorescent Line Emission from Young Stellar Objects in the Orion Nebula

    E-Print Network [OSTI]

    M. Tsujimoto; E. D. Feigelson; N. Grosso; G. Micela; Y. Tsuboi; F. Favata; H. Shang; J. H. Kastner

    2004-12-25

    We present the result of a systematic search for the iron Kalpha fluorescent line at 6.4 keV among 1616 X-ray sources detected by ultra-deep Chandra observations of the Orion Nebula Cluster and the obscured Orion Molecular Cloud 1 population as part of the Chandra Orion Ultra-deep Project (COUP). Seven sources are identified to have an excess emission at 6.4 keV among 127 control sample sources with significant counts in the 6.0-9.0 keV band. These seven sources are young stellar objects (YSOs) characterized by intense flare-like flux variations, thermal spectra, and near-infrared (NIR) counterparts. The observed equivalent widths of the line cannot be attributed to the fluorescence by interstellar or circumstellar matter along the line of sight. The X-ray spectral fits and NIR colors of the 6.4 keV sources show that these sources have X-ray absorption of > 1x10^22 cm^(-2) and NIR excess emission, which is not expected when the fluorescence occurs at the stellar photosphere. We therefore conclude that the iron fluorescent line of YSOs arises from reflection off of circumstellar disks, which are irradiated by the hard X-ray continuum emission of magnetic reconnection flares.

  3. "Weighing" Photon Energies with Mass Spectrometry: Effects of Water on Ion Fluorescence

    E-Print Network [OSTI]

    Neumark, Daniel M.

    "Weighing" Photon Energies with Mass Spectrometry: Effects of Water on Ion Fluorescence William A to internal energy can occur rapidly. The resulting energy is released by evaporating water molecules from results in a large number of water molecules lost from the reduced precursors.2 The energy deposited

  4. ISSUANCE 2015-06-17: Energy Conservation Standards for Fluorescent Lamp Ballasts, Notice of Public Meeting and Availability of the Framework Document

    Office of Energy Efficiency and Renewable Energy (EERE)

    Energy Conservation Standards for Fluorescent Lamp Ballasts, Notice of Public Meeting and Availability of the Framework Document

  5. ISSUANCE 2015-08-14: Energy Efficiency Program for Consumer Products: Energy Conservation Standards for Fluorescent Lamp Ballasts, Reopening of the Comment Period

    Broader source: Energy.gov [DOE]

    Energy Efficiency Program for Consumer Products: Energy Conservation Standards for Fluorescent Lamp Ballasts, Reopening of the Comment Period

  6. The use of fluorescent intrabodies to detect endogenous gankyrin in living cancer cells

    SciTech Connect (OSTI)

    Rinaldi, Anne-Sophie; Freund, Guillaume; Desplancq, Dominique; Sibler, Annie-Paule; Baltzinger, Mireille [Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch (France); Rochel, Natacha [Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, CNRS/INSERM/Université de Strasbourg, rue Laurent Fries, 67404 Illkirch (France); Mély, Yves; Didier, Pascal [Faculté de Pharmacie, UMR 7213, CNRS/Université de Strasbourg, route du Rhin, 67401 Illkirch (France); Weiss, Etienne, E-mail: eweiss@unistra.fr [Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch (France)

    2013-04-01

    Expression of antibody fragments in mammalian cells (intrabodies) is used to probe the target protein or interfere with its biological function. We previously described the in vitro characterisation of a single-chain Fv (scFv) antibody fragment (F5) isolated from an intrabody library that binds to the oncoprotein gankyrin (GK) in solution. Here, we have isolated several other scFvs that interact with GK in the presence of F5 and tested whether they allow, when fused to fluorescent proteins, to detect by FRET endogenous GK in living cells. The binding of pairs of scFvs to GK was analysed by gel filtration and the ability of each scFv to mediate nuclear import/export of GK was determined. Binding between scFv-EGFP and RFP-labelled GK in living cells was detected by fluorescence lifetime imaging microscopy (FLIM). After co-transfection of two scFvs fused to EGFP and RFP, respectively, which form a tri-molecular complex with GK in vitro, FRET signal was measured. This system allowed us to observe that GK is monomeric and distributed throughout the cytoplasm and nucleus of several cancer cell lines. Our results show that pairs of fluorescently labelled intrabodies can be monitored by FLIM–FRET microscopy and that this technique allows the detection of lowly expressed endogenous proteins in single living cells. Highlights: ? Endogenous GK in living cells was targeted with pairs of fluorescently-tagged scFvs. ? Tri-molecular complexes containing two scFvs and one molecule GK were formed. ? GK was detected using fluorescence lifetime-based FRET imaging. ? GK is monomeric and homogeneously distributed in several cancer cell lines. ? This technique may have many applications in live-cell imaging of endogenous proteins.

  7. Comparative Studies on the Structure and Stability of Fluorescent Proteins EGFP, zFP506, mRFP1, "dimer2", and DsRed1

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    -like fluorescent proteins, we have undertaken a systematic analysis of series of green and red fluorescent proteins with different association states. The list of studied proteins includes EGFP (green monomer), zFP506 (green). Cloning of green fluorescent protein (GFP)1 from the jellyfish Aequorea Victoria (class Hydrozoa) (2

  8. Fluorescence modulation in single CdSe quantum dots by moderate applied electric fields

    SciTech Connect (OSTI)

    LeBlanc, Sharonda J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Department of Mechanical Engineering and Engineering Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); McClanahan, Mason R.; Moyer, Tully; Moyer, Patrick J. [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States); Jones, Marcus [Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States)

    2014-01-21

    Single molecule time-resolved fluorescence spectroscopy of CdSe/ZnS core-shell quantum dots (QDs) under the influence of moderate applied electric fields reveals distributed emission from states which are neither fully on nor off and pronounced changes in the excited state decay. The data suggest that a 54?kV/cm applied electric field causes small perturbations to the QD surface charge distribution, effectively increasing the surface trapping probability and resulting in the appearance of gray states. We present simultaneous blinking and fluorescence decay results for two sets of QDs, with and without an applied electric field. Further kinetic modeling analysis suggests that a single trapped charged cannot be responsible for a blinking off event.

  9. The use of fluorescence spectroscopy to monitor operation in petroleum hydrocracking units

    SciTech Connect (OSTI)

    Fetzer, J.C.

    1994-12-31

    The catalytic hydrocracking is used in refineries to convert petroleum-derived feedstocks into motor fuels and lubricating oils. Polycyclic aromatic hydrocarbons (PAHs) are produced as by-products in the process. The PAHs lead to a variety of process and product problems. The specific PAHs produced have been identified through the use of HPLC-DAD and fluorescence and mass spectroscopies. A set of production reactions have been determined that explain the observed PAHs. A synchronous-scanning fluorescence (SSF) method has been used to determine the levels of several kerge PAHs, including dicoronylene. This fifteen-ring PAH is the main cause of plugging in process piping, which necessitates expensive shutdown and cleaning of the process. This PAH is too large to be amenable to chromatographic methods. Its extremely low solubility, in a mixture of other PAHs show the advantages of SSF.

  10. Enhanced-locality fiber-optic two-photon-fluorescence live-brain interrogation

    SciTech Connect (OSTI)

    Fedotov, I. V.; Doronina-Amitonova, L. V.; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Anokhin, K. V.; Kilin, S. Ya.; Sakoda, K.; Zheltikov, A. M.

    2014-02-24

    Two-photon excitation is shown to substantially enhance the locality of fiber-based optical interrogation of strongly scattering biotissues. In our experiments, a high-numerical-aperture, large-core-are fiber probe is used to deliver the 200-fs output of a 100-MHz mode-locked ytterbium fiber laser to samples of live mouse brain, induce two-photon fluorescence of nitrogen–vacancy centers in diamond markers in brain sample. Fiber probes with a high numerical aperture and a large core area are shown to enable locality enhancement in fiber-laser–fiber-probe two-photon brain excitation and interrogation without sacrificing the efficiency of fluorescence response collection.

  11. Observation of Fluorescence Emissions from Single-Bubble Sonoluminescence in Water doped with Quinine

    E-Print Network [OSTI]

    Lu, J Q; Lin, F K; Liu, Y H

    2005-01-01

    Sonoluminescence is a phenomenon involving the transduction of sound into light. The detailed mechanism as well as the energy-focusing potentials are not yet fully explored and understood. So far only optical photons are observed, while emissions in the ultra-violet range are only inferred. By doping the fluorescent dye quinine into water with dilute sulphuric acid, the high energy photons can be converted into the optical photons with slower decay constants. These sonoluminescence and fluorescent emissions were observed in coincidence, and the emitted energy of the two modes can be differentiated by their respective timing profiles. Plans for using this technique as a diagnostic tool to quantitatively study ultra-violet and other high energy emissions in sonoluminescence are discussed.

  12. Characterization of microenvironment polarity and solvent accessibility of polysilsesquioxane xerogels by the fluorescent probe technique

    SciTech Connect (OSTI)

    Shea, K.J.; Zhu, H.D. [Univ., of California, Irvine, CA (United States). Dept. of Chemistry; Loy, D.A. [Sandia National Labs., Albuquerque, NM (United States)

    1995-05-01

    Poly (1, 4 bis(triethoxysilyl)benzene) (PTESB), a representative of a new type of organic-inorganic hybrid polysilsesquioxane material, was characterized by fluorescence spectroscopy for both microenvironmental polarity and solvent accessibility. A dansyl fluorescent molecule was incorporated into the bulk as well as onto the surface of both PTESB and silica materials. Information about the microenvironment polarity and accessibility of PTESB to various organic solvents was determined and compared to that of silica gel. This study found that both the bulk and surface of PTESB are less polar than that of the silica material. The silica material is accessible to polar solvents and water, while YMB is accessible to polar solvents but not to water. The hydrophobicity of PTESB differentiates these new materials from silica gel.

  13. The daily cycle of fluorescence in vivo in the Central Equatorial Pacific 

    E-Print Network [OSTI]

    Setser, Patrick James

    1980-01-01

    be larger due to more than one investigator collecting samples. [& 0 0 0 0 a 0 0 (& 0 DO 0 D 0 l& 0 o Q Q 0 E3 QD o boa 0 0 Q Cl l& D 0 Q Cl 0 . OO Q Dp 0 0 Q DOCI Q OD 0 CI I& Q 0 0 W 0 t& Cl 0 Ol DQ GO a D CL o C3 o (~m 5m) s~uam5.../V GYRE Continuous surface in vivo fluorescence (relative units) at survey "Site A" from Aug. 21 - Aug. 25. A break in data collection occurs from midnight of Aug. 23 to 0400L on Aug. 25. Hourly surface in vivo fluorescence (relative units...

  14. Flow Cell Assays with Microtubules: Motility/Dynamics in Fluorescence and VE-DIC

    E-Print Network [OSTI]

    Mitchison, Tim

    Flow Cell Assays with Microtubules: Motility/Dynamics in Fluorescence and VE-DIC Flow cell assays procedures for flow cell assays. I. Solutions & Supplies BRB80 (1X): 80 mM PIPES, 1 mM MgCl2, 1 mM EGTA, pH 6 below) Flow Cells: Flow cells can be constructed in many different ways. The most common way is to place

  15. A Fluorescent Aerogel for Capture and Identification of Interplanetary and Interstellar Dust

    E-Print Network [OSTI]

    Gerardo Dominguez; Andrew J. Westphal; Mark L. F. Phillips; Steven M. Jones

    2003-03-27

    Contemporary interstellar dust has never been analyzed in the laboratory, despite its obvious astronomical importance and its potential as a probe of stellar nucleosynthesis and galactic chemical evolution. Here we report the discovery of a novel fluorescent aerogel which is capable of capturing hypervelocity dust grains and passively recording their kinetic energies. An array of these "calorimetric" aerogel collectors in low earth orbit would lead to the capture and identification of large numbers of interstellar dust grains.

  16. Luminescent studies of fluorescent chromophore-doped silica aerogels for flat panel display applications

    SciTech Connect (OSTI)

    Glauser, S.A.C. [California Univ., Davis, CA (United States). Dept. of Applied Science; Lee, H.W.H. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The remarkable optical and electronic properties of doped and undoped silica aerogels establish their utility as unique, mulitfunctional host materials for fluorescent dyes and other luminescent materials for display and imaging applications. We present results on the photoluminescence, absorption, and photoluminescence excitation spectra of undoped silica aerogels and aerogels doped with Er{sup 3+}, rhodamine 6G (R6G), and fluorescein. 4 refs., 12 figs.

  17. 2015-01-28 Issuance: Test Procedure for Fluorescent Lamp Ballasts; Final Rule Correction

    Broader source: Energy.gov [DOE]

    This document is a pre-publication Federal Register final rule correction regarding test procedures for fluorescent lamp ballasts, as issued by the Deputy Assistant Secretary for Energy Efficiency on January 28, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

  18. Simulation of air shower image in fluorescence light based on energy deposits derived from CORSIKA

    E-Print Network [OSTI]

    D. Gora; D. Heck; P. Homola; H. Klages; J. Pekala; M. Risse; B. Wilczynska; H. Wilczynski

    2004-03-01

    Spatial distributions of energy deposited by an extensive air shower in the atmosphere through ionization, as obtained from the CORSIKA simulation program, are used to find the fluorescence light distribution in the optical image of the shower. The shower image derived in this way is somewhat smaller than that obtained from the NKG lateral distribution of particles in the shower. The size of the image shows a small dependence on the primary particle type.

  19. Evaluation of Portable X-Ray Fluorescence (XRF) Analyzer for Zirconium-Thickness Measurements

    SciTech Connect (OSTI)

    Glenn Moore

    2013-09-01

    This Technical Evaluation Report provides details of preliminary testing/experiments performed using a handheld X-ray fluorescence analyzer. The analyzer will be utilized in upcoming fuel-foil-rolling optimization studies at the INL. The studies are being performed in support of DOE’s Office of Global Threat Reduction -- Reactor Conversion Subprogram. Details of the equipment used, operating parameters, and measurement results are provided in this report.

  20. Multispectral UV Fluorescence Detection of a Dilute Constituent in an Optically Dense Matrix

    SciTech Connect (OSTI)

    Chan, O.H.; Gray, P.C., Wehlburg, C.M.; Rubenstein, R.; Tisone, G.C.; Wagner, J.S.

    1998-10-15

    Multispectral UV fluorescence measurements were made of an optically dense medium (fetal bovine serum, FBS) spiked with sodium salicylate at concentrate ions from 0.2 to 500 pg/ml . Analysis of the spectra show that, depending on experimental conditions, reasonably good estimates of concentration can be obtained across the entire range of concentrate ions. Experimental conditions required for recovering these estimates are demonstrated.

  1. Relative fluorescent efficiency of sodium salicylate between 90 and 800 eV

    SciTech Connect (OSTI)

    Angel, G.C.; Samson, J.A.R.; Williams, G.

    1986-01-01

    The relative fluorescent quantum efficiency of sodium salicylate was measured between 90 and 800 eV (138 -15 A) by the use of synchrotron radiation. A general increase in efficiency was observed in this spectral range except for abrupt decreases in efficiency at the carbon and oxygen K-edges. Beyond the oxygen K-edge (532 eV) the efficiency increased linearly with the incident photon energy to the limit of the present observations.

  2. Investigation and technique in the fluorescent spectra examination of crude oil 

    E-Print Network [OSTI]

    Chambers, Gilbert Vester

    1958-01-01

    INVESTIGATION AND TECHNIQUE IN THE FLUORESCENT SPECTRA EXAMINATION OF CRUDE OIL A THESIS by Gilbert V. Chambers Approved as to style and content by: ha man o zt 1 ead o Department or Stu ent Adv sor January 1958 AGKNOWLEDGEhlENT... 40 IX. BIBLIOGRAPHY . . ~ . . ~ ~ ~ ~ . ~ . ~ ~ . 42 X. APPEND IX ~ A. Development of Technique: Run Number 1. Run Number 2. Run Number 5. B. Results: g5 52 ~ ~ ~ ~ ~ ~ ~ 60 West Texas Sour Crude Oil . . . . . . 69 East Texas Crud. e Oil...

  3. TESTING OF ENERGY CONSERVATION OF ELECTRONIC BALLASTS FOR FLUORESCENT LIGHTING REVIEW OF RECENT RESULTS AND RECOMMENDATIONS FOR DESIGN GOALS

    E-Print Network [OSTI]

    Verderber, R.R.

    2011-01-01

    Ur:.V(. ,(lh. Fluorescent Lighting Review of Recent Resultsfrom 30 0 C to 50°C. The lighting system.with core ballastswas conducted to measure the lighting system performance for

  4. IEEE TRANSACTIONS ON NANOBIOSCIENCE, VOL. 5, NO. 1, MARCH 2006 41 Computational Modeling of a New Fluorescent

    E-Print Network [OSTI]

    IEEE TRANSACTIONS ON NANOBIOSCIENCE, VOL. 5, NO. 1, MARCH 2006 41 Computational Modeling of a New Truong, Member, IEEE Abstract--The class of fluorescence resonance energy transfer (FRET) protein

  5. Selective turn-on fluorescence detection of cyanide in water using hydrophobic CdSe quantum dots 

    E-Print Network [OSTI]

    Dryden D.T.F.; Mareque-Rivas J.C.; Galve-Gasion J.A.; Stevenson E.I.; Touceda-Varela A.

    2008-05-01

    The ability of 2,2'-bipyridine-bound copper(II) ions to quench the photoluminescence of hydrophobic CdSe quantum dots is used to create a novel, selective turn-on fluorescence cyanide sensor.

  6. Use of 2-Aminopurine Fluorescence as a probe of DNA and computational studies of a new class of base analogues 

    E-Print Network [OSTI]

    Wu, Xiaohua

    2012-06-22

    The steady-state and time-resolved fluorescence of 2-aminopurine (2AP) have been used to monitor base dynamics and base stacking interactions in DNA single strands and dinucleotides, and to investigate the interactions ...

  7. Turn-on fluorescence in tetraphenylethylene-based metal-organic frameworks: An alternative to aggregation-induced emission

    E-Print Network [OSTI]

    Shustova, Natalia B.

    Coordinative immobilization of functionalized tetraphenylethylene within rigid porous metal–organic frameworks (MOFs) turns on fluorescence in the typically non-emissive tetraphenylethylene core. The matrix coordination-induced ...

  8. Fluorescence enhanced optical tomography on breast phantoms with measurements using a gain modulated intensified CCD imaging system 

    E-Print Network [OSTI]

    Godavarty, Anuradha

    2005-08-29

    Fluorescence-enhanced optical imaging using near-infrared (NIR) light developed for in-vivo molecular targeting and reporting of cancer provides promising opportunities for diagnostic imaging. However, prior to the ...

  9. Micromolding of a Highly Fluorescent Reticular Coordination Polymer: Solvent-Mediated Reconfigurable Polymerization in a Soft Lithographic Mold

    SciTech Connect (OSTI)

    Y You; H Yang; J Chung; J Kim; Y Jung; S Park

    2011-12-31

    Coordination polymerization of pyridine-based ligands and zinc or silver ions was controlled by soft lithographic micromolding in capillaries. The polymer patterns that are produced are highly fluorescent and supramolecularly structured.

  10. Increasing proliferation resistance of sodium fast reactor fuel cycle through use of a nuclear resonance fluorescence detector

    E-Print Network [OSTI]

    Smith, David Ballin

    2010-01-01

    The proliferation resistance of a reprocessing facility can be improved by using a novel detection system that utilizes the nuclear resonance fluorescence (NRF) phenomenon to determine the isotopic composition of materials ...

  11. Split green fluorescent protein as a modular binding partner for protein crystallization

    SciTech Connect (OSTI)

    Nguyen, Hau B. [Los Alamos National Laboratory, MS M888, Los Alamos, NM 87545 (United States); Hung, Li-Wei [Los Alamos National Laboratory, MS D454, Los Alamos, NM 87545 (United States); Yeates, Todd O. [University of California, PO Box 951569, Los Angeles, CA 90095 (United States); Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov; Waldo, Geoffrey S., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, MS M888, Los Alamos, NM 87545 (United States)

    2013-12-01

    A strategy using a new split green fluorescent protein (GFP) as a modular binding partner to form stable protein complexes with a target protein is presented. The modular split GFP may open the way to rapidly creating crystallization variants. A modular strategy for protein crystallization using split green fluorescent protein (GFP) as a crystallization partner is demonstrated. Insertion of a hairpin containing GFP ?-strands 10 and 11 into a surface loop of a target protein provides two chain crossings between the target and the reconstituted GFP compared with the single connection afforded by terminal GFP fusions. This strategy was tested by inserting this hairpin into a loop of another fluorescent protein, sfCherry. The crystal structure of the sfCherry-GFP(10–11) hairpin in complex with GFP(1–9) was determined at a resolution of 2.6 Å. Analysis of the complex shows that the reconstituted GFP is attached to the target protein (sfCherry) in a structurally ordered way. This work opens the way to rapidly creating crystallization variants by reconstituting a target protein bearing the GFP(10–11) hairpin with a variety of GFP(1–9) mutants engineered for favorable crystallization.

  12. Acceptance of fluorescence detectors and its implication in energy spectrum inference at the highest energies

    E-Print Network [OSTI]

    Vitor de Souza; Gustavo Medina-Tanco; Jeferson A. Ortiz

    2005-09-20

    Along the years HiRes and AGASA experiments have explored the fluorescence and the ground array experimental techniques to measure extensive air showers, being both essential to investigate the ultra-high energy cosmic rays. However, such Collaborations have published contradictory energy spectra for energies above the GZK cut-off. In this article, we investigate the acceptance of fluorescence telescopes to different primary particles at the highest energies. Using CORSIKA and CONEX shower simulations without and with the new pre-showering scheme, which allows photons to interact in the Earth magnetic field, we estimate the aperture of the HiRes-I telescope for gammas, iron nuclei and protons primaries as a function of the number of simulated events and primary energy. We also investigate the possibility that systematic differences in shower development for hadrons and gammas could mask or distort vital features of the cosmic ray energy spectrum at energies above the photo-pion production threshold. The impact of these effects on the true acceptance of a fluorescence detector is analyzed in the context of top-down production models.

  13. H_2 Absorption and Fluorescence for Gamma Ray Bursts in Molecular Clouds

    E-Print Network [OSTI]

    B. T. Draine

    1999-07-16

    If a gamma ray burst with strong UV emission occurs in a molecular cloud, there will be observable consequences resulting from excitation of the surrounding H2. The UV pulse from the GRB will pump H2 into vibrationally-excited levels which produce strong absorption at wavelengths < 1650 A. As a result, both the prompt flash and later afterglow will exhibit strong absorption shortward of 1650 A, with specific spectroscopic features. Such a cutoff in the emission from GRB 980329 may already have been observed by Fruchter et al.; if so, GRB 980329 was at redshift 3.0 < z < 4.4 . BVRI photometry of GRB 990510 could also be explained by H2 absorption if GRB 990510 is at redshift 1.6 < z < 2.3. The fluorescence accompanying the UV pumping of the H2 will result in UV emission from the GRB which can extend over days or months, depending on parameters of the ambient medium and beaming of the GRB flash. The 7.5-13.6 eV fluorescent luminosity is \\sim 10^{41.7} erg/s for standard estimates of the parameters of the GRB and the ambient medium. Spectroscopy can distinguish this fluorescent emission from other possible sources of transient optical emission, such as a supernova.

  14. Yellow fluorescent protein phiYFPv (Phialidium): structure and structure-based mutagenesis

    SciTech Connect (OSTI)

    Pletneva, Nadya V.; Pletnev, Vladimir Z., E-mail: vzpletnev@gmail.com; Souslova, Ekaterina; Chudakov, Dmitry M. [Russian Academy of Sciences, Moscow (Russian Federation); Lukyanov, Sergey [Russian Academy of Sciences, Moscow (Russian Federation); Nizhny Novgorod State Medical Academy, Nizhny Novgorod (Russian Federation); Martynov, Vladimir I.; Arhipova, Svetlena; Artemyev, Igor [Russian Academy of Sciences, Moscow (Russian Federation); Wlodawer, Alexander [National Cancer Institute, Frederick, MD 21702 (United States); Dauter, Zbigniew [National Cancer Institute, Argonne, IL 60439 (United States); Pletnev, Sergei [National Cancer Institute, Argonne, IL 60439 (United States); SAIC-Frederick, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Russian Academy of Sciences, Moscow (Russian Federation)

    2013-06-01

    The yellow fluorescent protein phiYFPv with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The yellow fluorescent protein phiYFPv (?{sub em}{sup max} ? 537 nm) with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The latter fluorescent protein is one of only two known cases of naturally occurring proteins that exhibit emission spectra in the yellow–orange range (535–555 nm). Here, the crystal structure of phiYFPv has been determined at 2.05 Å resolution. The ‘yellow’ chromophore formed from the sequence triad Thr65-Tyr66-Gly67 adopts the bicyclic structure typical of fluorophores emitting in the green spectral range. It was demonstrated that perfect antiparallel ?-stacking of chromophore Tyr66 and the proximal Tyr203, as well as Val205, facing the chromophore phenolic ring are chiefly responsible for the observed yellow emission of phiYFPv at 537 nm. Structure-based site-directed mutagenesis has been used to identify the key functional residues in the chromophore environment. The obtained results have been utilized to improve the properties of phiYFPv and its homologous monomeric biomarker tagYFP.

  15. A method of measuring gold nanoparticle concentrations by x-ray fluorescence for biomedical applications

    SciTech Connect (OSTI)

    Wu Di; Li Yuhua; Wong, Molly D.; Liu Hong [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2013-05-15

    Purpose: This paper reports a technique that enables the quantitative determination of the concentration of gold nanoparticles (GNPs) through the accurate detection of their fluorescence radiation in the diagnostic x-ray spectrum. Methods: Experimentally, x-ray fluorescence spectra of 1.9 and 15 nm GNP solutions are measured using an x-ray spectrometer, individually and within chicken breast tissue samples. An optimal combination of excitation and emission filters is determined to segregate the fluorescence spectra at 66.99 and 68.80 keV from the background scattering. A roadmap method is developed that subtracts the scattered radiation (acquired before the insertion of GNP solutions) from the signal radiation acquired after the GNP solutions are inserted. Results: The methods effectively minimize the background scattering in the spectrum measurements, showing linear relationships between GNP solutions from 0.1% to 10% weight concentration and from 0.1% to 1.0% weight concentration inside a chicken breast tissue sample. Conclusions: The investigation demonstrated the potential of imaging gold nanoparticles quantitatively in vivo for in-tissue studies, but future studies will be needed to investigate the ability to apply this method to clinical applications.

  16. Iron Fluorescent Line Emission from Young Stellar Objects in the Orion Nebula

    E-Print Network [OSTI]

    Tsujimoto, M; Grosso, N; Micela, G; Tsuboi, Y; Favata, F; Shang, H; Kästner, J H

    2004-01-01

    We present the result of a systematic search for the iron Kalpha fluorescent line at 6.4 keV among 1616 X-ray sources detected by ultra-deep Chandra observations of the Orion Nebula Cluster and the obscured Orion Molecular Cloud 1 population as part of the Chandra Orion Ultra-deep Project (COUP). Seven sources are identified to have an excess emission at 6.4 keV among 127 control sample sources with significant counts in the 6.0-9.0 keV band. These seven sources are young stellar objects (YSOs) characterized by intense flare-like flux variations, thermal spectra, and near-infrared (NIR) counterparts. The observed equivalent widths of the line cannot be attributed to the fluorescence by interstellar or circumstellar matter along the line of sight. The X-ray spectral fits and NIR colors of the 6.4 keV sources show that these sources have X-ray absorption of > 1x10^22 cm^(-2) and NIR excess emission, which is not expected when the fluorescence occurs at the stellar photosphere. We therefore conclude that the iro...

  17. Application of a ratiometric laser induced fluorescence (LIF) thermometry for micro-scale temperature measurement for natural convection flows 

    E-Print Network [OSTI]

    Lee, Heon Ju

    2004-11-15

    ????????????????????????. x CHAPTER I INTRODUCTION??????????????????? 1 1.1 Literature Review??????????..???????. 1 1.2 Summary of Present Study??????????.....??? 2 II BACKGROUND???????????????????? 4 2.1 Principle of Fluorescence & Ratiometric LIF... Process: The White Arrows Represent That Water Circulates the Thermo-baths to Maintain Isothermal Conditions.. 10 3.2 Temperature Dependence of Fluorescence Images of Rh-B (column (a)), Rh-110 (column (b)) and Their Ratiometric Images (column (c...

  18. Recovery of yttrium from fluorescent powder of cathode ray tube, CRT: Zn removal by sulphide precipitation

    SciTech Connect (OSTI)

    Innocenzi, Valentina, E-mail: valentina.innocenzi1@univaq.it [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); De Michelis, Ida; Ferella, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy); Beolchini, Francesca [Department of Marine Sciences, Polytechnic Institute of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Kopacek, Bernd [SAT, Austrian Society for Systems Engineering and Automation, Gurkasse 43/2, A-1140 Vienna (Austria); Vegliò, Francesco [Department of Industrial Engineering and Information and Economy, University of L’Aquila, Via Giovanni Gronchi n.18, Nucleo Ind.le di Pile, 67100 L’Aquila (Italy)

    2013-11-15

    Highlights: • Treatment of fluorescent powder of CRT waste. • Factorial experimental designs to study acid leaching of fluorescent powder and the purification of leach liquors. • Recover of yttrium by precipitation using oxalic acid. • Suitable flowsheet to recover yttrium from fluorescent powder. - Abstract: This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2{sup 2} full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H{sub 2}O{sub 2} concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction. Two series of precipitation tests for zinc are carried out: a 2{sup 2} full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na{sub 2}S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%.

  19. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    SciTech Connect (OSTI)

    Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  20. Characterization of supernumerary ring marker chromosomes by fluorescence in situ hybridization (FISH)

    SciTech Connect (OSTI)

    Blennow, E.; Nordenskjoeld, M. ); Asadi, E. ); Anneren, G.; Berggren, E.; Nordenskjoeld, M.

    1993-08-01

    Five cases with small supernumerary ring chromosomes are characterized at the molecular level. Routine chromosome banding analysis was insufficient for identification of the ring chromosomes, and none of them was DA/DAPI positive. Fluorescence in situ hybridization utilizing repetitive centromeric probes for all chromosomes has determined that one of these five ring chromosomes originates in each of chromosomes 4, 7, 8, 9, and 20. Chromosome painting with chromosome-specific libraries has confirmed this and excluded the involvement of additional chromosomes in the rearrangements. 30 refs., 3 figs., 2 tabs.

  1. Quantitative characterization of a nonreacting, supersonic combustor flowfield using unified, laser-induced iodine fluorescence

    SciTech Connect (OSTI)

    Fletcher, D.G.; McDaniel, J.C.

    1989-01-01

    A calibrated, nonintrusive optical technique, laser-induced iodine fluorescence (LIIF) was used to quantify the steady, compressible flowfield of a nonreacting, supersonic combustor. The combustor was configured with single and staged, transverse-air injection into a supersonic-air freestream behind a rearward-facing step. Pressure, temperature, two-velocity components, and injectant mole fraction were measured with high spatial resolution in the three-dimensional flowfields. These experimental results provide a benchmark set of data for validation of computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields. 8 refs.

  2. High-efficiency white organic light-emitting diodes using thermally activated delayed fluorescence

    SciTech Connect (OSTI)

    Nishide, Jun-ichi; Hiraga, Yasuhide; Nakanotani, Hajime; Adachi, Chihaya

    2014-06-09

    White organic light-emitting diodes (WOLEDs) have attracted much attention recently, aimed for next-generation lighting sources because of their high potential to realize high electroluminescence efficiency, flexibility, and low-cost manufacture. Here, we demonstrate high-efficiency WOLED using red, green, and blue thermally activated delayed fluorescence materials as emissive dopants to generate white electroluminescence. The WOLED has a maximum external quantum efficiency of over 17% with Commission Internationale de l'Eclairage coordinates of (0.30, 0.38).

  3. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    DOE Patents [OSTI]

    Smith, Robert E. [557 Escondido Cir., Livermore, CA 94550; Dolbeare, Frank A. [5178 Diane La., Livermore, CA 94550

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

  4. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    DOE Patents [OSTI]

    Smith, R.E.; Dolbeare, F.A.

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

  5. Trace Detection of Metastable Helium Molecules in Superfluid Helium by Laser-Induced Fluorescence

    E-Print Network [OSTI]

    D. N. McKinsey; W. H. Lippincott; J. Nikkel; W. Rellergert

    2005-03-11

    We describe an approach to detecting ionizing radiation that combines the special properties of superfluid helium with the sensitivity of quantum optics techniques. Ionization in liquid helium results in the copious production of metastable helium molecules, which can be detected by laser-induced fluorescence. Each molecule can be probed many times using a cycling transition, resulting in the detection of individual molecules with high signal to noise. This technique could be used to detect neutrinos, weakly interacting massive particles, and ultracold neutrons, and to image superfluid flow in liquid He-4.

  6. Single molecule detection and underwater fluorescence imaging with cantilevered near-field fiber optic probes

    E-Print Network [OSTI]

    Talley, Chad E.; Lee, M. Annie; Dunn, Robert C.

    1998-04-03

    ! ~sigma!, doped with 131026 mol % fluo- rescent 1, 18-dioctadecyl-3,3,38,38-tetramethylindocarbo- cyanine perchlorate (diIC18) ~Molecular Probes!, were de- posited onto a mica surface at a surface pressure of 15 mN/m utilizing the Langmuir... s demonstrate both the subdiffraction limit the cantilevered probe design. Images taken al a degradation in the resolution as the ied, however, a minimum plateau region in reased, indicating that the tapping mode of of fluorescently doped lipid films illustrate...

  7. Metal enhanced fluorescence in rare earth doped plasmonic core-shell nanoparticles

    E-Print Network [OSTI]

    Derom, S; Pillonnet, A; Benamara, O; Jurdyc, A M; Girard, C; Francs, G Colas des

    2013-01-01

    We theoretically and numerically investigate metal enhanced fluorescence of plasmonic core-shell nanoparticles doped with rare earth (RE) ions. Particle shape and size are engineered to maximize the average enhancement factor (AEF) of the overall doped shell. We show that the highest enhancement (11 in the visible and 7 in the near-infrared) are achieved by tuning either the dipolar or quadrupolar particle resonance to the rare earth ions excitation wavelength. Additionally, the calculated AEFs are compared to experimental data reported in the literature, obtained in similar conditions (plasmon mediated enhancement) or when a metal-RE energy transfer mechanism is involved.

  8. Cross Sections for the Electron Activation of Gamma-Ray Fluorescence

    E-Print Network [OSTI]

    Silviu Olariu; Agata Olariu; Yoshiaki Ito; Takeshi Mukoyama

    2000-06-26

    We report cross sections for the direct excitation of gamma-ray transitions up to 200 keV by the transient electromagnetic fields of electrons from a beam, for incident kinetic energies of 500 keV and 5 MeV. The cross sections for the electron activation of gamma-ray fluorescence are of the order of 300 nanobarns for an electron incident kinetic energy of 500 keV, and are of the order of 10 microbarns for an electron incident kinetic energy of 5 MeV. The electron excitation of nuclear transitions may lead to the development of pulsed sources of gamma radiation of narrowly defined energy.

  9. Nuclear Resonance Fluorescence at MIT | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe23-24, 2011 HighMay AdvancedMuonNovemberResonance Fluorescence at

  10. Max Tech and Beyond: Fluorescent Lamps (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(JournalspectroscopyReport) | SciTech Connect Mathematical andFluorescent Lamps

  11. Max Tech and Beyond: Fluorescent Lamps (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(JournalspectroscopyReport) | SciTech Connect Mathematical andFluorescent

  12. Method and apparatus for enhanced evanescent fluorescence and color filtering using a high refractive index thin film coating

    DOE Patents [OSTI]

    Kao, Hung Pin (2124 Promontory Cir., San Ramon, CA 94583); Schoeniger, Joseph (126 Echo Ave., Oakland, CA 94611); Yang, Nancy (72 Bacon Ct., Lafayette, CA 94549)

    2001-01-01

    A technique for increasing the excitation and collection of evanescent fluorescence radiation emanating from a fiber optic sensor having a high refractive index (n.sub.r), dielectric thin film coating has been disclosed and described. The invention comprises a clad optical fiber core whose cladding is removed on a distal end, the distal end coated with a thin, non-porous, titanium dioxide sol-gel coating. It has been shown that such a fiber will exhibit increased fluorescence coupling due in part by 1) increasing the intensity of the evanescent field at the fiber core surface by a constructive interference effect on the propagating light, and 2) increasing the depth of penetration of the field in the sample. The interference effect created by the thin film imposes a wavelength dependence on the collection of the fluorescence and also suggests a novel application of thin films for color filtering as well as increasing collected fluorescence in fiber sensors. Collected fluorescence radiation increased by up to 6-fold over that of a bare fused silica fiber having a numerical aperture (N.A.) of O.6.

  13. Standard test method for determination of uranium or gadolinium (or both) in gadolinium oxide-uranium oxide pellets or by X-ray fluorescence (XRF)

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    Standard test method for determination of uranium or gadolinium (or both) in gadolinium oxide-uranium oxide pellets or by X-ray fluorescence (XRF)

  14. Nonflame, source-induced sulfur fluorescence detector for sulfur-containing compounds

    SciTech Connect (OSTI)

    Gage, D.R.; Farwell, S.O.

    1980-12-01

    Results of some preliminary investigations of the fluorescence spectra of S/sub 2/ and the non-flame production of S/sub 2/ from sulfur-containing molecules are reported. Passage of the gas to be analyzed through a catalyst-oven containing a plug of NiO/sub 2//Al/sub 2/O/sub 3/ catalyst containing 10 wt% NiO/sub 2/ and heated to 400/sup 0/C resulted in conversion of H/sub 2/S to S/sub 2/ and elemental sulfur. The S/sub 2/ was detected by measurement of its fluorescence bands at 260 and 310nm, and elemental sulfur condensed on the cool parts of the apparatus. However, determination of sulfur-content of gas mixtures with the apparatus described herein were not as repeatable as desired, and the work is being continued on various facets of the non-flame system with work being directed toward the evaluation of different catalysts, catalyst temperature, design of a smaller detector geometry utilizing a pulsed-light excitation source, a windowless cell, and optical filters instead of monochromators to select the S/sub 2/ excitation and emission wavelengths. (BLM)

  15. Synchrotron Radiation {mu}-X Ray Fluorescence on Multicellular Tumor Spheroids

    SciTech Connect (OSTI)

    Burattini, E.; Cinque, G.; Bellisola, G.; Fracasso, G.; Colombatti, M.; Monti, F.

    2003-01-24

    Synchrotron Radiation micro X-Ray Fluorescence (SR {mu}-XRF) was applied for the first time to map the trace element content on Multicellular Tumor Spheroids (MTS), i.e. human cell clusters used as an in vitro model for testing micrometastases responses to antitumoral drugs. In particular, immunotoxin molecules composed of a carrier protein (Transferrin) bound to a powerful cytotoxin (Ricin A), were here considered as representatives of a class of therapheutic macromolecules used in cancer theraphy. Spheroids included in polyacrylamide gel and placed inside quartz capillaries were studied at the ESRF ID22 beamline using a 15 keV monochromatic photon microbeam. Elemental maps (of Fe, Cu, Zn and Pb) on four groups of spheroids grown under different conditions were studied: untreated, treated only with the carrier molecule or with the toxin alone, and with the complete immunotoxin molecule (carrier+toxin). The results indicate that the distribution of Zn and, to some extent, Cu in the spheroid cells is homogeneous and independent of the treatment type. Total Reflection X-Ray Fluorescence (TR-XRF) was also applied to quantify the average trace element content in the spheroids. Future developments of the technique are finally outlined on the basis of these preliminary results.

  16. OH-Planar Fluorescence Measurements of Pressurized, Hydrogen Premixed Flames in the SimVal Combustor

    SciTech Connect (OSTI)

    Strakey, P.A.; Woodruff, S.D.; Williams, T.C.; Schefer, R.W.

    2008-07-01

    Planar laser-induced fluorescence measurements of the hydroxyl radical in lean, premixed natural gas flames augmented with hydrogen are presented. The experiments were conducted in the Simulation Validation combustor at the National Energy Technology Laboratory at operating pressures from 1 to 8 atmospheres. The data, which were collected in a combustor with well-controlled boundary conditions, are intended to be used for validating computational fluid dynamics models under conditions directly relevant to land-based gas turbine engines. The images, which show significant effects of hydrogen on local flame quenching, are discussed in terms of a turbulent premixed combustion regime and nondimensional parameters such as Karlovitz number. Pressure was found to thin the OH region, but only had a secondary effect on overall flame shape compared with the effects of hydrogen addition, which was found to decrease local quenching and shorten the turbulent flame brush. A method to process the individual images based on local gradients of fluorescence intensity is proposed, and results are presented. Finally, the results of several large eddy simulations are presented and compared with the experimental data in an effort to understand the issues related to model validation, especially for simulations that do not include OH as an intermediate species.

  17. Measurement of plutonium in spent nuclear fuel by self-induced x-ray fluorescence

    SciTech Connect (OSTI)

    Hoover, Andrew S; Rudy, Cliff R; Tobin, Steve J; Charlton, William S; Stafford, A; Strohmeyer, D; Saavadra, S

    2009-01-01

    Direct measurement of the plutonium content in spent nuclear fuel is a challenging problem in non-destructive assay. The very high gamma-ray flux from fission product isotopes overwhelms the weaker gamma-ray emissions from plutonium and uranium, making passive gamma-ray measurements impossible. However, the intense fission product radiation is effective at exciting plutonium and uranium atoms, resulting in subsequent fluorescence X-ray emission. K-shell X-rays in the 100 keV energy range can escape the fuel and cladding, providing a direct signal from uranium and plutonium that can be measured with a standard germanium detector. The measured plutonium to uranium elemental ratio can be used to compute the plutonium content of the fuel. The technique can potentially provide a passive, non-destructive assay tool for determining plutonium content in spent fuel. In this paper, we discuss recent non-destructive measurements of plutonium X-ray fluorescence (XRF) signatures from pressurized water reactor spent fuel rods. We also discuss how emerging new technologies, like very high energy resolution microcalorimeter detectors, might be applied to XRF measurements.

  18. Two-photon induced fluorescence and other optical effects in irradiated and doped fused silica

    SciTech Connect (OSTI)

    Kramer, S.D.

    1986-07-01

    The objective of this program was to assess and identify irradiation techniques which could be used to modify the optical charactistics of doped fused silica. Primary emphasis was placed on determining if gamma ray or neutron bombardment of the glass would enhance certain Raman and nonlinear optical effects. In particular, the effect of irradiation on optical two photon induced fluorescence was studied in detail. The maximum radiation exposures used were 10/sup 6/ rads (Si) of gamma rays and neutron fluences of 1 x 10/sup 14/ neutrons/cm/sup 2/. The optical measurements were made at room temperature between one and four months after irradiation. The maximum input light intensity was 10/sup 9/ watts/cm/sup 2/ at a near infrared (1.06 ..mu..) input wavelength which was chosen to lie in a transparent spectral region of the glass. Under these experimental conditions a careful search revealed no detectable two-photon induced fluorescence in the region from 550 to 900 nm. The upper limit for the photon efficiency of this process was determined to be less than 1 x 10/sup -10/%. 89 refs., 12 figs.

  19. Isotopic imaging via nuclear resonance fluorescence with laser-based Thomson radiation

    DOE Patents [OSTI]

    Barty, Christopher P. J. (Hayward, CA); Hartemann, Frederic V. (San Ramon, CA); McNabb, Dennis P. (Alameda, CA); Pruet, Jason A. (Brentwood, CA)

    2009-07-21

    The present invention utilizes novel laser-based, high-brightness, high-spatial-resolution, pencil-beam sources of spectrally pure hard x-ray and gamma-ray radiation to induce resonant scattering in specific nuclei, i.e., nuclear resonance fluorescence. By monitoring such fluorescence as a function of beam position, it is possible to image in either two dimensions or three dimensions, the position and concentration of individual isotopes in a specific material configuration. Such methods of the present invention material identification, spatial resolution of material location and ability to locate and identify materials shielded by other materials, such as, for example, behind a lead wall. The foundation of the present invention is the generation of quasimonochromatic high-energy x-ray (100's of keV) and gamma-ray (greater than about 1 MeV) radiation via the collision of intense laser pulses from relativistic electrons. Such a process as utilized herein, i.e., Thomson scattering or inverse-Compton scattering, produces beams having diameters from about 1 micron to about 100 microns of high-energy photons with a bandwidth of .DELTA.E/E of approximately 10E.sup.-3.

  20. Dual x-ray fluorescence spectrometer and method for fluid analysis

    DOE Patents [OSTI]

    Wilson, Bary W.; Shepard, Chester L.

    2005-02-22

    Disclosed are an X-ray fluorescence (SRF) spectrometer and method for on-site and in-line determination of contaminant elements in lubricating oils and in fuel oils on board a marine vessel. An XRF source block 13 contains two radionuclide sources 16, 17 (e.g. Cd 109 and Fe 55), each oriented 180 degrees from the other to excite separate targets. The Cd 109 source 16 excites sample lube oil flowing through a low molecular weight sample line 18. The Fe 55 source 17 excites fuel oil manually presented to the source beam inside a low molecular weight vial 26 or other container. Two separate detectors A and B are arranged to detect the fluorescent x-rays from the targets, photons from the analyte atoms in the lube oil for example, and sulfur identifying x-rays from bunker fuel oil for example. The system allows both automated in-line and manual on-site analysis using one set of signal processing and multi-channel analyzer electronics 34, 37 as well as one computer 39 and user interface 43.

  1. Centimeter-deep tissue fluorescence microscopic imaging with high signal-to-noise ratio and picomole sensitivity

    E-Print Network [OSTI]

    Cheng, Bingbing; Wei, Ming-Yuan; Pei, Yanbo; DSouza, Francis; Nguyen, Kytai T; Hong, Yi; Tang, Liping; Yuan, Baohong

    2015-01-01

    Fluorescence microscopic imaging in centimeter-deep tissue has been highly sought-after for many years because much interesting in vivo micro-information, such as microcirculation, tumor angiogenesis, and metastasis, may deeply locate in tissue. In this study, for the first time this goal has been achieved in 3-centimeter deep tissue with high signal-to-noise ratio (SNR) and picomole sensitivity under radiation safety thresholds. These results are demonstrated not only in tissue-mimic phantoms but also in actual tissues, such as porcine muscle, ex vivo mouse liver, ex vivo spleen, and in vivo mouse tissue. These results are achieved based on three unique technologies: excellent near infrared ultrasound-switchable fluorescence (USF) contrast agents, a sensitive USF imaging system, and an effective correlation method. Multiplex USF fluorescence imaging is also achieved. It is useful to simultaneously image multiple targets and observe their interactions. This work opens the door for future studies of centimeter...

  2. Near-infrared fluorescence glucose sensing based on glucose/galactose-binding protein coupled to 651-Blue Oxazine

    SciTech Connect (OSTI)

    Khan, Faaizah; Pickup, John C.

    2013-08-30

    Highlights: •We showed that the NIR fluorophore, 651-Blue Oxazine, is solvatochromic (polarity sensitive). •Blue Oxazine was covalently attached to mutants of glucose/galactose-binding protein (GBP). •Fluorescence intensity of GBP-Blue Oxazine increased with addition of glucose. •Fluorescence from bead-immobilised GBP-Blue Oxazine was detectable through skin in vitro. •This shows proof-of-concept for non-invasive glucose sensing using GBP-Blue Oxazine. -- Abstract: Near-infrared (NIR) fluorescent dyes that are environmentally sensitive or solvatochromic are useful tools for protein labelling in in vivo biosensor applications such as glucose monitoring in diabetes since their spectral properties are mostly independent of tissue autofluorescence and light scattering, and they offer potential for non-invasive analyte sensing. We showed that the fluorophore 651-Blue Oxazine is polarity-sensitive, with a marked reduction in NIR fluorescence on increasing solvent polarity. Mutants of glucose/galactose-binding protein (GBP) used as the glucose receptor were site-specifically and covalently labelled with Blue Oxazine using click chemistry. Mutants H152C/A213R and H152C/A213R/L238S showed fluorescence increases of 15% and 21% on addition of saturating glucose concentrations and binding constants of 6 and 25 mM respectively. Fluorescence responses to glucose were preserved when GBP-Blue Oxazine was immobilised to agarose beads, and the beads were excited by NIR light through a mouse skin preparation studied in vitro. We conclude GBP-Blue Oxazine shows proof-of-concept as a non-invasive continuous glucose sensing system.

  3. Alignment-dependent fluorescence emission induced by tunnel ionization of carbon dioxide from lower-lying orbitals

    E-Print Network [OSTI]

    Yao, Jinping; Jia, Xinyan; Hao, Xiaolei; Zeng, Bin; Jing, Chenrui; Chu, Wei; Ni, Jielei; Zhang, Haisu; Xie, Hongqiang; Zhang, Chaojin; Zhao, Zengxiu; Chen, Jing; Liu, Xiaojun; Cheng, Ya; Xu, Zhizhan

    2013-01-01

    We show that fluorescence emission induced by strong field tunnel ionization of carbon dioxide from its lower-lying orbitals exhibits a peculiar molecular alignment dependence. The experimentally measured alignment-dependence of the fluorescence agrees with the alignment-dependence of the ionization probability calculated in the framework of the strong field approximation. Our results demonstrate the feasibility of an all-optical approach for shedding more light on the ionization mechanisms of molecules from their lower-lying orbitals in tunnel ionization regime.

  4. Dynamic characterization of hydrophobic and hydrophilic solutes in oleic-acid enhanced transdermal delivery using two-photon fluorescence microscopy

    SciTech Connect (OSTI)

    Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Tsung-Hua [Department of Dermatology, Far Eastern Memorial Hospital, New Taipei City, Taiwan (China); Dong, Chen-Yuan, E-mail: cydong@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Center for Optoelectronic Biomedicine, National Taiwan University, Taipei, Taiwan (China)

    2014-10-20

    In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.

  5. The fluorescence action spectra of some saturated hydrocarbon liquids for excitation energies above and below their ionization thresholds

    SciTech Connect (OSTI)

    Ostafin, A.E.; Lipsky, S. )

    1993-04-01

    Fluorescence action spectra have been obtained for the neat liquids, [ital cis]-decalin, [ital trans]-decalin, bicyclohexyl, cyclohexane, methylcyclohexane, isobutylcyclohexane, 2,3,4-trimethylpentane, 2,3-dimethylbutane, 3-methylhexane, 3-methylpentane, [ital n]-decane, [ital n]-dodecane, and [ital n]-pentadecane at excitation energies, [epsilon], ranging from their absorption onsets (at ca. 7 eV) to 10.3 eV. For all compounds, with the exception of [ital cis]-decalin, the fluorescence quantum yield is observed to monotonically decline with increasing [epsilon], reaching a minimum value at an energy, [epsilon][sub [ital m

  6. PhotochemisfvondPhofobiology. 1971 . Vol. 14,pp. 667-682. PergamonPress. Printed in Great Britain FLUORESCENCE INDUCTION IN THE RED ALGA

    E-Print Network [OSTI]

    Govindjee

    FLUORESCENCE INDUCTION IN THE RED ALGA PORPHYRIDIUM CRUENTUM P. MOHANTY, G. PAPAGEORGIOU* and GOVINDJEE in the red alga Porphyridium cruentum. Both the fast and the slow fluorescence yield changes are affected algae both in the fast (sec) and in the slow (min) region (see Refs. [l-31). Characteristic points

  7. Fabrication of fluorescent composite with ultrafast aqueous synthesized high luminescent CdTe quantum dots

    SciTech Connect (OSTI)

    Zhang, Lei, E-mail: mejswu@ust.hk; Chen, Haibin, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk; Wu, Jingshen, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk [Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong and Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong); Bi, Xianghong, E-mail: takubatch@gmail.com [Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong)

    2014-05-15

    Without precursor preparation, inert gas protection and enormous amount of additives and reductants, CdTe quantum dots (QDs) can be rapidly synthesized with high quality. A 600 nm photoluminescence peak wavelength could be obtained within 1 hour's refluxing through minimal addition of 1,2-diaminoethane (DAE). The theoretical design for the experiments are illustrated and further proved by the characterization results with different concentrations and reagents. On the other hand, generation of CdTe QDs was found even under room temperature by applying droplet quantity of DAE. This indicates that QDs can be synthesized with simply a bottle and no enormous additives required. The QDs were mixed into the epoxy matrix through solution casting method with cetyltrimethylammonium (CTA) capping for phase transfer. The acquired epoxy based nanocomposite exhibits good transparency, compatibility and fluorescence.

  8. Discovery of Variable Iron Fluorescence from Reflection Nebulae in the Galactic Center

    E-Print Network [OSTI]

    M. P. Muno; F. K. Baganoff; W. N. Brandt; S. Park; M. R. Morris

    2006-11-21

    Based on three years of deep observations of the Galactic center with the Chandra X-ray Observatory, we report the discovery of changes in the intensities and morphologies of two hard X-ray nebulosities. The nebulosities are dominated by fluorescent iron emission, and are coincident with molecular clouds. The morphological changes are manifest on parsec scales, which requires that these iron features are scattered X-rays from a 2 or 3-year-long outburst of a point source (either Sgr A* or an X-ray binary) with a luminosity of at least 1e37 erg/s. The variability precludes the hypotheses that these nebulae either are produced by keV electrons bombarding molecular clouds, or are iron-rich ejecta from supernovae. Moreover, the morphologies of the reflection nebulae implies that the dense regions of the clouds are filamentary, with widths of ~0.3 pc and lengths of ~2 pc.

  9. 100-OL-1 Operable Unit Field Portable X-Ray Fluorescence (XRF) Analyzer Pilot Study Plans

    SciTech Connect (OSTI)

    Bunn, Amoret L.; Fritz, Brad G.; Wellman, Dawn M.

    2014-07-15

    A pilot study is being conducted to support the approval of the Remedial Investigation/Feasibility Study (RI/FS) Work Plan to evaluate the 100-OL-1 Operable Unit (OU) pre-Hanford orchard lands. Based on comments received by the U.S. Environmental Protection Agency (EPA) and Washington State Department of Ecology, the pilot study will evaluate the use of field portable X-ray fluorescence (XRF) spectrometry measurements for evaluating lead and arsenic concentrations on the soil surface as an indicator of past use of lead arsenate pesticide residue in the OU. The work will be performed in the field during the summer of 2014, and assist in the planning for the characterization activities in the RI/FS.

  10. Fluorescence and polarization spectroscopy of single silicon vacancy centers in heteroepitaxial nanodiamonds on iridium

    E-Print Network [OSTI]

    Elke Neu; Martin Fischer; Stefan Gsell; Matthias Schreck; Christoph Becher

    2011-10-24

    We introduce an advanced material system for the production and spectroscopy of single silicon vacancy (SiV) color centers in diamond. We use microwave plasma chemical vapor deposition to synthesize heteroepitaxial nanodiamonds of approx. 160 nm in lateral size with a thickness of approx. 75 nm. These oriented 'nanoislands' combine the enhanced fluorescence extraction from subwavelength sized nanodiamonds with defined crystal orientation. The investigated SiV centers display narrow zero-phonon-lines down to 0.7 nm in the wavelength range 730-750 nm. We investigate in detail the phonon-coupling and vibronic sidebands of single SiV centers, revealing significant inhomogeneous effects. Polarization measurements reveal polarized luminescence and preferential absorption of linearly polarized light.

  11. Fluorescence and polarization spectroscopy of single silicon vacancy centers in heteroepitaxial nanodiamonds on iridium

    E-Print Network [OSTI]

    Neu, Elke; Gsell, Stefan; Schreck, Matthias; Becher, Christoph

    2011-01-01

    We introduce an advanced material system for the production and spectroscopy of single silicon vacancy (SiV) color centers in diamond. We use microwave plasma chemical vapor deposition to synthesize heteroepitaxial nanodiamonds of approx. 160 nm in lateral size with a thickness of approx. 75 nm. These oriented 'nanoislands' combine the enhanced fluorescence extraction from subwavelength sized nanodiamonds with defined crystal orientation. The investigated SiV centers display narrow zero-phonon-lines down to 0.7 nm in the wavelength range 730-750 nm. We investigate in detail the phonon-coupling and vibronic sidebands of single SiV centers, revealing significant inhomogeneous effects. Polarization measurements reveal polarized luminescence and preferential absorption of linearly polarized light.

  12. Temperature dependence of photoluminescence properties in a thermally activated delayed fluorescence emitter

    SciTech Connect (OSTI)

    Niwa, Akitsugu; Kobayashi, Takashi Nagase, Takashi; Naito, Hiroyoshi; Goushi, Kenichi; Adachi, Chihaya

    2014-05-26

    Using steady-state and time-resolved photoluminescence (PL) spectroscopy, we have investigated the temperature dependence of PL properties of 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyano-benzene (4CzIPN), which have a small energy gap between its singlet and triplet excited states and thus exhibits efficient thermally activated delayed fluorescence [H. Uoyama et al., Nature 492, 235 (2012)]. Below around 100?K, PL quantum efficiency of 4CzIPN thin films is largely suppressed and strong photoexcitation intensity dependence appears. These features can be explained by using rate equations for the densities of singlet and triplet excited states considering a triplet-triplet annihilation process.

  13. Real-time method and apparatus for measuring the temperature of a fluorescing phosphor

    DOE Patents [OSTI]

    Britton, Jr., Charles L. (Alcoa, TN); Beshears, David L. (Knoxville, TN); Simpson, Marc L. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Allison, Steve W. (Knoxville, TN)

    1999-01-01

    A method for determining the temperature of a fluorescing phosphor is provided, together with an apparatus for performing the method. The apparatus includes a photodetector for detecting light emitted by a phosphor irradiated with an excitation pulse and for converting the detected light into an electrical signal. The apparatus further includes a differentiator for differentiating the electrical signal and a zero-crossing discrimination circuit that outputs a pulse signal having a pulse width corresponding to the time period between the start of the excitation pulse and the time when the differentiated electrical signal reaches zero. The width of the output pulse signal is proportional to the decay-time constant of the phosphor.

  14. Assessment of the Fluorescence and Auger Data Base used in Plasma Modeling

    E-Print Network [OSTI]

    T. W. Gorczyca; C. N. Kodituwakku; K. T. Korista; O. Zatsarinny; N. R. Badnell; E. Behar; M. H. Chen; D. W. Savin

    2003-04-10

    We have investigated the accuracy of the 1s-vacancy fluorescence data base of Kaastra & Mewe (1993, A&AS, 97, 443) resulting from the initial atomic physics calculations and the subsequent scaling along isoelectronic sequences. In particular, we have focused on the relatively simple Be-like and F-like 1s-vacancy sequences. We find that the earlier atomic physics calculations for the oscillator strengths and autoionization rates of singly-charged B II and Ne II are in sufficient agreement with our present calculations. However, the substantial charge dependence of these quantities along each isoelectronic sequence, the incorrect configuration averaging used for B II, and the neglect of spin-orbit effects (which become important at high-Z) all cast doubt on the reliability of the Kaastra & Mewe data for application to plasma modeling.

  15. Emission spectra of atoms with non-Markovian interaction: Fluorescence in a photonic crystal

    E-Print Network [OSTI]

    Ines de Vega; Daniel Alonso

    2007-11-09

    We present a formula to evaluate the spontaneous emission spectra of an atom in contact with a radiation field with non-Markovian effects. This formula is written in terms of a two-time correlation of system observables and the environmental correlation function, and depends on the distance between the emitting atom and the detector. As an example, we use it to analyze the fluorescence spectra of a two level atom placed as an impurity in a photonic crystal. The radiation field within those materials has a gap or discontinuity where electromagnetic modes cannot propagate in the stationary limit. In that situation, the atomic emission occurs in the form of evanescent waves which are detected with less efficiency the farther we place the detector. The methodology presented in this paper may be useful to study the non-Markovian dynamics of any quantum open system in linear interaction with a harmonic oscillator reservoir and within the weak coupling approximation.

  16. Integrated starting and running amalgam assembly for an electrodeless fluorescent lamp

    DOE Patents [OSTI]

    Borowiec, Joseph Christopher (Schenectady, NY); Cocoma, John Paul (Clifton Park, NY); Roberts, Victor David (Burnt Hills, NY)

    1998-01-01

    An integrated starting and running amalgam assembly for an electrodeless SEF fluorescent lamp includes a wire mesh amalgam support constructed to jointly optimize positions of a starting amalgam and a running amalgam in the lamp, thereby optimizing mercury vapor pressure in the lamp during both starting and steady-state operation in order to rapidly achieve and maintain high light output. The wire mesh amalgam support is constructed to support the starting amalgam toward one end thereof and the running amalgam toward the other end thereof, and the wire mesh is rolled for friction-fitting within the exhaust tube of the lamp. The positions of the starting and running amalgams on the wire mesh are jointly optimized such that high light output is achieved quickly and maintained, while avoiding any significant reduction in light output between starting and running operation.

  17. Probing the photoluminescence properties of gold nanoclusters by fluorescence lifetime correlation spectroscopy

    SciTech Connect (OSTI)

    Yuan, C. T., E-mail: ctyuan@cycu.edu.tw; Lin, T. N.; Shen, J. L. [Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan (China) [Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan (China); Center for Biomedical Technology, Chung Yuan Christian University, Taiwan (China); Lin, C. A.; Chang, W. H. [Center for Biomedical Technology, Chung Yuan Christian University, Taiwan (China) [Center for Biomedical Technology, Chung Yuan Christian University, Taiwan (China); Department of Biomedical Engineering, Chung Yuan Christian University, Taiwan (China); Cheng, H. W. [Department of Engineering and system science, National Tsing Hua University, Taiwan (China)] [Department of Engineering and system science, National Tsing Hua University, Taiwan (China); Tang, J., E-mail: jautang@gate.sinica.edu.tw [Research Center for Applied Sciences, Academia Sinica, Taiwan (China)

    2013-12-21

    Gold nanoclusters (Au NCs) have attracted much attention for promising applications in biological imaging owing to their tiny sizes and biocompatibility. So far, most efforts have been focused on the strategies for fabricating high-quality Au NCs and then characterized by conventional ensemble measurement. Here, a fusion single-molecule technique combining fluorescence correlation spectroscopy and time-correlated single-photon counting can be successfully applied to probe the photoluminescence (PL) properties for sparse Au NCs. In this case, the triplet-state dynamics and diffusion process can be observed simultaneously and the relevant time constants can be derived. This work provides a complementary insight into the PL mechanism at the molecular levels for Au NCs in solution.

  18. Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

    E-Print Network [OSTI]

    Fujii, T; Bertaina, M; Casolino, M; Dawson, B; Horvath, P; Hrabovsky, M; Jiang, J; Mandat, D; Matalon, A; Matthews, J N; Motloch, P; Palatka, M; Pech, M; Privitera, P; Schovanek, P; Takizawa, Y; Thomas, S B; Travnicek, P; Yamazaki, K

    2015-01-01

    We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Tele- scopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometres as well as 16 highly significant UHECR shower candidates.

  19. Dimeric fluorescent energy transfer dyes comprising asymmetric cyanine azole-indolenine chromophores

    DOE Patents [OSTI]

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Oakland, CA)

    1998-01-01

    Novel fluorescent heterodimeric DNA-staining energy transfer dyes are provided combining asymmetric cyanine azole-indolenine dyes, which provide for strong DNA affinity, large Stokes shifts and emission in the red region of the spectrum. The dyes find particular application in gel electrophoresis and for labels which may be bound to a variety of compositions in a variety of contexts. Kits and individual compounds are provided, where the kits find use for simultaneous detection of a variety of moieties, particularly using a single narrow wavelength irradiation source. The individual compounds are characterized by high donor quenching and high affinity to dsDNA as a result of optimizing the length of the linking group separating the two chromophores.

  20. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    E-Print Network [OSTI]

    Gehman, V M; Rielage, K; Hime, A; Sun, Y; Mei, D -M; Maassen, J; Moore, D

    2011-01-01

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  1. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    E-Print Network [OSTI]

    V. M. Gehman; S. R. Seibert; K. Rielage; A. Hime; Y. Sun; D. -M. Mei; J. Maassen; D. Moore

    2011-09-22

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  2. COMPARISON OF LEAD CONCENTRATION IN SURFACE SOIL BY INDUCTED COUPLED PLASMA/OPTICAL EMISSION SPECTROMETRY AND X-RAY FLUORESCENCE

    E-Print Network [OSTI]

    Boyer, Edmond

    COMPARISON OF LEAD CONCENTRATION IN SURFACE SOIL BY INDUCTED COUPLED PLASMA/OPTICAL EMISSION-en-Halatte, France roseline.bonnard@ineris.fr) Keywords : soil lead concentration, soil samples, in situ measurements, X-ray fluorescence, ICP/OES ABSTRACT The lead concentration in the surface soil of a French village

  3. Influence of the water content on X-ray fluorescence core-scanning measurements in soft marine sediments

    E-Print Network [OSTI]

    Tjallingii, Rik

    Influence of the water content on X-ray fluorescence core- scanning measurements in soft marine properties such as density and water content on XRF core scanner data. Comparison of XRF scanner measurements for the radiation absorption of the water content in sediment core GeoB7920 off Cape Blanc, NW Africa. Components

  4. Insight into the Common Mechanism of the Chromophore Formation in the Red Fluorescent Proteins: The Elusive Blue

    E-Print Network [OSTI]

    Verkhusha, Vladislav V.

    : The Elusive Blue Intermediate Revealed Ksenia B. Bravaya, Oksana M. Subach, Nadezhda Korovina, Vladislav V calculations identifying the nature of a blue intermediate, a key species in the process of the red chromophore formation in DsRed, TagRFP, fluorescent timers, and PAmCherry. The chromophore of the blue intermediate has

  5. Fluorescence energy transfer efficiency in labeled yeast cytochrome c: a rapid screen for ion biocompatibility in aqueous ionic liquids

    SciTech Connect (OSTI)

    Baker, Sheila N; Zhao, Hua; Pandey, Siddharth; Heller, William T; Bright, Frank; Baker, Gary A

    2011-01-01

    A fluorescence energy transfer de-quenching assay was implemented to follow the equilibrium unfolding behaviour of site-specific tetramethylrhodamine-labelled yeast cytochrome c in aqueous ionic liquid solutions; additionally, this approach offers the prospect of naked eye screening for biocompatible ion combinations in hydrated ionic liquids.

  6. Proceedings of ICRC 2001: 769 c Copernicus Gesellschaft 2001 First measurements with the AUGER fluorescence detector data

    E-Print Network [OSTI]

    2000 the collaboration has started to in- stall an engineering array consisting of 40 tanks and 2 tele experimental results by measur- ing the energy spectrum, the arrival direction and the iso- Correspondence to distributed water tanks and the Fluorescence Detector (FD) with 30 tele- scopes which watch the night sky

  7. Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J. Hagen

    E-Print Network [OSTI]

    Hagen, Stephen J.

    Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J i.d.) at a speed 20 cm/s, under laminar flow conditions (Re 14). Construction from a fused silica studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial

  8. Transposing Molecular Fluorescent Switches into the Near-IR: Development of Luminogenic Reporter Substrates for Redox Metabolism

    E-Print Network [OSTI]

    Turro, Nicholas J.

    Transposing Molecular Fluorescent Switches into the Near-IR: Development of Luminogenic Reporter communicate the development of a NIR luminescent redox switch, based on a Nd(III) complex, that serves to afford a good luminescent switch.9 Since the sensitization of lanthanide metals is assumed to occur via

  9. Two-photon excited fluorescence in the LYB:Eu monoclinic crystal: towards a new scheme of

    E-Print Network [OSTI]

    Boyer, Edmond

    . Graener, "Femtosecond laser assisted production of dichroitic 3D structures in composite glass containing processes. ©2013 Optical Society of America OCIS codes: (160.1190) Anisotropic optical materials; (260 focuses, leading to a single-beam dual-voxel nonlinear excitation of fluorescence below material

  10. Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design

    E-Print Network [OSTI]

    Boyer, Edmond

    Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes Light Emitting Diode (OLED), intermolecular p­p interactions should be usually suppressed to avoid any Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted Di

  11. Red-shifted fluorescent proteins mPlum and mRaspberry and polynucleotides encoding the same

    DOE Patents [OSTI]

    Tsien, Roger Y. (La Jolla, CA); Wang, Lei (San Diego, CA)

    2008-07-01

    Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

  12. Summary Spectral reflectance and chlorophyll fluores-cence are rapid non-invasive methods that can be used to quan-

    E-Print Network [OSTI]

    Richardson, Andrew D.

    hypothesized that keeping broadleaf samples cool and moist would delay the onset of reflectance, paper birch that had been kept cool and moist after cutting showed only slight changes in fluorescence and continually following branch cutting, because con- tinued transpiration caused a draw down of leaf water poten

  13. PHYSICAL REVIEW E 87, 012403 (2013) Layer with reduced viscosity at water-oil interfaces probed by fluorescence correlation spectroscopy

    E-Print Network [OSTI]

    Chan, Derek Y C

    2013-01-01

    PHYSICAL REVIEW E 87, 012403 (2013) Layer with reduced viscosity at water-oil interfaces probed-dimensional diffusion of isolated molecular tracers at the water­n-alkane interface was studied with fluorescence. INTRODUCTION Water is the most common liquid on Earth and con- stitutes a major part of living organisms

  14. Fluorescence Lifetimes and Emission Patterns Probe the 3D Orientation of the Emitting Chromophore in a Multichromophoric System

    E-Print Network [OSTI]

    Enderlein, Jörg

    Fluorescence Lifetimes and Emission Patterns Probe the 3D Orientation of the Emitting Chromophore the orientation of the absorption transition dipole)15,16 and wide-field defocusing (probing the emission. It was suggested that, at any moment in time, the emission of a single dendrimer originates from the chromophore

  15. An HPLC-Fluorescence Method for Identifying a Toxic Fraction Extracted from the Marine Dinoflagellate Gambierdiscus toxicus

    E-Print Network [OSTI]

    An HPLC-Fluorescence Method for Identifying a Toxic Fraction Extracted from the Marine, no analytical method, having high analytical preci- sion and a low detection limit, present- ly exists. A radioimmunoassay method (Hokama et aI., lfJ77) was reported using immunoglobulin isolated from sheep that had been

  16. Laser fluorescence study of AIO formed in the reaction AI + O2: Product state distribution, dissociation energy, and radiative

    E-Print Network [OSTI]

    Laser fluorescence study of AIO formed in the reaction AI + O2: Product state distribution, dissociation energy, and radiative lifetime P. J. Dagdigian*, H. W. Cruset, and R. N. Zare Department distributions are found to differ significantly, with v = 0 having more rotational excitation than v = I

  17. Laser-Induced Fluorescence Measurement of the Ion-Energy-Distribution Function in a Collisionless Reconnection Experiment

    E-Print Network [OSTI]

    Egedal, Jan

    Laser-Induced Fluorescence Measurement of the Ion-Energy-Distribution Function in a Collisionless for Plasma Physics, EURATOM Association, Greifswald 17491, Germany 2 Massachusetts Institute of Technology], which makes the reconnection drive independent from plasma production. For the present study

  18. Cancer optical imaging using fluorescent nanoparticles Developing imaging technologies and molecular probes that allow cancer detection at its

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Cancer optical imaging using fluorescent nanoparticles Developing imaging technologies in the drug development process very early in the laboratory, during the translation phase from in vitro to the acquisition of molecular information including Positron Emission Tomography (PET), Single photon emission

  19. Characterization of the influence of 1-butyl-3-methylimidazolium chloride on the structure and thermal stability of green fluorescent protein

    SciTech Connect (OSTI)

    Heller, William T [ORNL; O'Neill, Hugh Michael [ORNL; Zhang, Qiu [ORNL; Baker, Gary A [ORNL

    2010-01-01

    Ionic liquids (ILs) are finding a vast array of applications as novel solvents for a wide variety of processes that include enzymatic chemistry, particularly as more biocompatible ILs are designed and discovered. While it is assumed that a native or near-native structure is required for enzymatic activity, there is some evidence that ILs alter protein structure and oligomerization states in a manner than can negatively impact function. The IL 1-butyl-3-methylimidazolium chloride, [bmim]Cl, is a well-studied, water-miscible member of the popular 1-alkyl-3-methylimidazolium IL family. To improve our understanding of the impact of water-miscible ILs on proteins, we have characterized the structure and oligomerization state of green fluorescent protein (GFP) in aqueous solutions containing 25 and 50 vol % [bmim]Cl using a combination of optical spectroscopy and small-angle neutron scattering (SANS). Measurements were also performed as a function of temperature to provide insight into the effect of the IL on the thermal stability of GFP. While GFP exists as a dimer in water, the presence of 25 vol % [bmim]Cl causes GFP to transition to a monomeric state. The SANS data indicate that GFP is a great deal less compact in 50 vol % [bmim]Cl than in neat water, indicative of unfolding from the native structure. The oligomerization state of the protein in IL-containing aqueous solution changes from a dimer to a monomer in response to the IL, but does not change as a function of temperature in the IL-containing solution. The SANS and spectroscopic results also demonstrate that the addition of [bmim]Cl to the solution decreases the thermal stability of GFP, allowing the protein to unfold at lower temperatures than in aqueous solution.

  20. Performance of T12 and T8 Fluorescent Lamps and Troffers and LED Linear Replacement Lamps CALiPER Benchmark Report

    SciTech Connect (OSTI)

    Myer, Michael; Paget, Maria L.; Lingard, Robert D.

    2009-01-16

    The Department of Energy (DOE) Commercially Available LED Product Evaluation and Reporting (CALiPER) Program was established in 2006 to investigate the performance of light-emitting diode (LED) based luminaires and replacement lamps. To help users better compare LED products with conventional lighting technologies, CALiPER has also performed benchmark research and testing of traditional (i.e., non-LED) lamps and fixtures. This benchmark report addresses standard 4-foot fluorescent lamps (i.e., T12 and T8) and the 2-foot by 4-foot recessed troffers in which they are commonly used. This report also examines available LED replacements for T12 and T8 fluorescent lamps, and their application in fluorescent troffers. The construction and operation of linear fluorescent lamps and troffers are discussed, as well as fluorescent lamp and fixture performance, based on manufacturer data and CALiPER benchmark testing. In addition, the report describes LED replacements for linear fluorescent lamps, and compares their bare lamp and in situ performance with fluorescent benchmarks on a range of standard lighting measures, including power usage, light output and distribution, efficacy, correlated color temperature, and the color rendering index. Potential performance and application issues indicated by CALiPER testing results are also examined.

  1. Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

    SciTech Connect (OSTI)

    Ludewigt, Bernhard A; Quiter, Brian J.; Ambers, Scott D.

    2011-01-14

    The Next Generation Safeguard Initiative (NGSI) of the U.S Department of Energy is supporting a multi-lab/university collaboration to quantify the plutonium (Pu) mass in spent nuclear fuel (SNF) assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. The following 14 NDA techniques are being studied: Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Lead Slowing Down Spectrometer, Neutron Multiplicity, Passive Neutron Albedo Reactivity, Total Neutron (Gross Neutron), X-Ray Fluorescence, {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Gamma, Nuclear Resonance Fluorescence, Passive Prompt Gamma, Self-integration Neutron Resonance Densitometry, and Neutron Resonance Transmission Analysis. Understanding and maturity of the techniques vary greatly, ranging from decades old, well-understood methods to new approaches. Nuclear Resonance Fluorescence (NRF) is a technique that had not previously been studied for SNF assay or similar applications. Since NRF generates isotope-specific signals, the promise and appeal of the technique lies in its potential to directly measure the amount of a specific isotope in an SNF assay target. The objectives of this study were to design and model suitable NRF measurement methods, to quantify capabilities and corresponding instrumentation requirements, and to evaluate prospects and the potential of NRF for SNF assay. The main challenge of the technique is to achieve the sensitivity and precision, i.e., to accumulate sufficient counting statistics, required for quantifying the mass of Pu isotopes in SNF assemblies. Systematic errors, considered a lesser problem for a direct measurement and only briefly discussed in this report, need to be evaluated for specific instrument designs in the future. Also, since the technical capability of using NRF to measure Pu in SNF has not been established, this report does not directly address issues such as cost, size, development time, nor concerns related to the use of Pu in measurement systems. This report discusses basic NRF measurement concepts, i.e., backscatter and transmission methods, and photon source and {gamma}-ray detector options in Section 2. An analytical model for calculating NRF signal strengths is presented in Section 3 together with enhancements to the MCNPX code and descriptions of modeling techniques that were drawn upon in the following sections. Making extensive use of the model and MCNPX simulations, the capabilities of the backscatter and transmission methods based on bremsstrahlung or quasi-monoenergetic photon sources were analyzed as described in Sections 4 and 5. A recent transmission experiment is reported on in Appendix A. While this experiment was not directly part of this project, its results provide an important reference point for our analytical estimates and MCNPX simulations. Used fuel radioactivity calculations, the enhancements to the MCNPX code, and details of the MCNPX simulations are documented in the other appendices.

  2. The rotational order–disorder structure of the reversibly photoswitchable red fluorescent protein rsTagRFP

    SciTech Connect (OSTI)

    Pletnev, Sergei, E-mail: pletnevs@mail.nih.gov [Argonne National Laboratory, Argonne, IL 60439 (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); Subach, Fedor V.; Verkhusha, Vladislav V. [Albert Einstein College of Medicine, Bronx, NY 10461 (United States); Dauter, Zbigniew, E-mail: pletnevs@mail.nih.gov [Argonne National Laboratory, Argonne, IL 60439 (United States)

    2014-01-01

    An analysis of the rotational order–disorder structure of the reversibly photoswitchable red fluorescent protein rsTagRFP is presented. The rotational order–disorder (OD) structure of the reversibly photoswitchable fluorescent protein rsTagRFP is discussed in detail. The structure is composed of tetramers of 222 symmetry incorporated into the lattice in two different orientations rotated 90° with respect to each other around the crystal c axis and with tetramer axes coinciding with the crystallographic twofold axes. The random distribution of alternatively oriented tetramers in the crystal creates the rotational OD structure with statistically averaged I422 symmetry. Despite order–disorder pathology, the structure of rsTagRFP has electron-density maps of good quality for both non-overlapping and overlapping parts of the model. The crystal contacts, crystal internal architecture and a possible mechanism of rotational OD crystal formation are discussed.

  3. Quantum-jumps and photon-statistic in fluorescent systems coupled to classically fluctuating reservoirs

    E-Print Network [OSTI]

    Adrian A. Budini

    2010-05-20

    In this paper, we develop a quantum-jump approach for describing the photon-emission process of single fluorophore systems coupled to complex classically fluctuating reservoirs. The formalism relies on an open quantum system approach where the dynamic of the system and the reservoir fluctuations are described through a density matrix whose evolution is defined by a Lindblad rate equation. For each realization of the photon measurement processes it is possible to define a conditional system state (stochastic density matrix) whose evolution depends on both the photon detection events and the fluctuations between the configurational states of the reservoir. In contrast to standard fluorescent systems the photon-to-photon emission process is not a renewal one, being defined by a (stochastic) waiting time distribution that in each recording event parametrically depends on the conditional state. The formalism allows calculating experimental observables such as the full hierarchy of joint probabilities associated to the time intervals between consecutive photon recording events. These results provide a powerful basis for characterizing different situations arising in single-molecule spectroscopy, such as spectral fluctuations, lifetime fluctuations, and light assisted processes.

  4. Analysis of Diffusion of Ras2 in Saccharomyces cerevisiae Using Fluorescence Recovery after Photobleaching

    E-Print Network [OSTI]

    Kalyan C. Vinnakota; David A. Mitchell; Robert J. Deschenes; Tetsuro Wakatsuki; Daniel A. Beard

    2010-05-10

    Binding, lateral diffusion and exchange are fundamental dynamic processes involved in protein association with cellular membranes. In this study, we developed numerical simulations of lateral diffusion and exchange of fluorophores in membranes with arbitrary bleach geometry and exchange of the membrane localized fluorophore with the cytosol during Fluorescence Recovery after Photobleaching (FRAP) experiments. The model simulations were used to design FRAP experiments with varying bleach region sizes on plasma-membrane localized wild type GFP-Ras2 with a dual lipid anchor and mutant GFP-Ras2C318S with a single lipid anchor in live yeast cells to investigate diffusional mobility and the presence of any exchange processes operating in the time scale of our experiments. Model parameters estimated using data from FRAP experiments with a 1 micron x 1 micron bleach region-of-interest (ROI) and a 0.5 micron x 0.5 micron bleach ROI showed that GFP-Ras2, single or dual lipid modified, diffuses as single species with no evidence of exchange with a cytoplasmic pool. This is the first report of Ras2 mobility in yeast plasma membrane. The methods developed in this study are generally applicable for studying diffusion and exchange of membrane associated fluorophores using FRAP on commercial confocal laser scanning microscopes.

  5. Highly Fluorescent Group 13 Metal Complexes with Cyclic, Aromatic Hydroxamic Acid Ligands

    SciTech Connect (OSTI)

    Seitz, Michael; Moore, Evan G.; Raymond, Kenneth N.

    2008-02-11

    The neutral complexes of two ligands based on the 1-oxo-2-hydroxy-isoquinoline (1,2-HOIQO) motif with group 13 metals (Al, Ga, In) show bright blue-violet luminescence in organic solvents. The corresponding transition can be attributed to ligand-centered singlet emission, characterized by a small Stokes shifts of only a few nm combined with lifetimes in the range between 1-3 ns. The fluorescence efficiency is high, with quantum yields of up to 37% in benzene solution. The crystal structure of one of the indium(III) complexes (trigonal space group R-3, a = b = 13.0384(15) {angstrom}, c = 32.870(8) {angstrom}, ? = {beta} = 90{sup o}, {gamma} = 120{sup o}, V = 4839.3(14) {angstrom}{sup 3}, Z = 6) shows a six-coordinate geometry around the indium center which is close to trigonal-prismatic, with a twist angle between the two trigonal faces of 20.7{sup o}. Time-dependent density functional theory (TD-DFT) calculations (Al and Ga: B3LYP/6-31G(d)); In: B3LYP/LANL2DZ of the fac and mer isomers with one of the two ligands indicate that there is no clear preference for either one of the isomeric forms of the metal complexes. In addition, the metal centers do not have a significant influence on the electronic structure, and as a consequence, on the predominant intraligand optical transitions.

  6. Synchrotron-based X-ray fluorescence imaging and elemental mapping from biological samples

    SciTech Connect (OSTI)

    D Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G Gigante

    2011-12-31

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of {approx}10 {mu}m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  7. Subwavenumber charge-coupled device spectrometer calibration using molecular iodine laser-induced fluorescence

    SciTech Connect (OSTI)

    Lambert, Joseph G. [Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Hernandez-Diaz, Carlos; Williamson, J. Charles [Department of Chemistry, Willamette University, Salem, Oregon 97301 (United States)

    2010-01-15

    Spectrometers configured with charge-coupled devices (CCD) or other array-based detectors require calibration to convert from the pixel coordinate to a spectral coordinate. A CCD calibration method well suited for Raman spectroscopy has been developed based on the 514.5 nm Ar{sup +} laser-induced fluorescence (LIF) spectrum of room-temperature molecular iodine vapor. Over 360 primary and secondary I{sub 2} LIF calibration lines spanning 510-645 nm were identified as calibrant peaks using an instrumental resolution of 1 cm{sup -1}. Two instrument calibration functions were evaluated with these peaks: a second-order polynomial and a function derived from simple optomechanical considerations. The latter function provided better fitting characteristics. Calibration using I{sub 2} LIF was tested with measurements of both laser light scattering and Raman spectra. The I{sub 2} LIF reference spectra and the signal spectra were recorded simultaneously, with no cross talk, by separating the two signals spatially along the vertical axis of the CCD imager. In this way, every CCD image could be independently calibrated. An accuracy and a precision of {+-}0.05 cm{sup -1} were achieved with this calibration technique.

  8. Note: A portable, light-emitting diode-based ruby fluorescence spectrometer for high-pressure calibration

    SciTech Connect (OSTI)

    Feng Yejun [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2011-04-15

    Ruby (Al{sub 2}O{sub 3}, with {approx}0.5 wt. % Cr doping) is one of the most widely used manometers at the giga-Pascal scale. Traditionally, its fluorescence is excited with intense laser sources. Here, I present a simple, robust, and portable design that employs light-emitting diodes (LEDs) instead. This LED-based system is safer in comparison with laser-based ones.

  9. Visualization of nitric oxide production in the mouse main olfactory bulb by a cell-trappable copper(II) fluorescent probe

    E-Print Network [OSTI]

    McQuade, Lindsey E.

    We report the visualization of NO production using fluorescence in tissue slices of the mouse main olfactory bulb. This discovery was possible through the use of a novel, cell-trappable probe for intracellular nitric oxide ...

  10. J. Phys. Chem. 1995, 99, 15153-15162 15153 Fluorescence Quenching of Pyrene by Copper(I1) in Sodium Dodecyl Sulfate Micelles.

    E-Print Network [OSTI]

    Bales, Barney

    J. Phys. Chem. 1995, 99, 15153-15162 15153 Fluorescence Quenching of Pyrene by Copper(I1) in Sodium, University of Uppsala, $75121 Uppsala, Sweden Received: March 27, 1995; In Final Form: June 23, 1995

  11. Relationships of Light Transmission, Stratification and Fluorescence in the Hypoxic Region of the Texas-Louisiana Shelf in Spring/Summer 2009 

    E-Print Network [OSTI]

    Towns, Jenny L

    2012-07-11

    , the relationship between transmissivity, photosynthetically available radiation (PAR), stratification, and fluorescence are analyzed. PAR is measured using a silicon photovoltaic detector and is measured in the 400 to 700 nm range. A fluorometer is used to measure...

  12. M13 Phage-Functionalized Single-Walled Carbon Nanotubes As Nanoprobes for Second Near-Infrared Window Fluorescence Imaging of Targeted Tumors

    E-Print Network [OSTI]

    Yi, Hyunjung

    Second near-infrared (NIR) window light (950–1400 nm) is attractive for in vivo fluorescence imaging due to its deep penetration depth in tissues and low tissue autofluorescence. Here we show genetically engineered ...

  13. Development of Fluorescent Reporters for Monitoring Fe-S Cluster Transfer Reactions and Discerning the Role of Glutaredoxin Proteins in Fe-S Cluster Assembly 

    E-Print Network [OSTI]

    Vranish, James Nicholas

    2015-04-27

    and persulfides to form clusters). The in vitro study of cluster transfer has been hampered by the lack of sufficient methods to investigate the kinetics of these processes. We have developed fluorescently labeled iron-sulfur cluster binding proteins...

  14. Robust and economical multi-sample, multi-wavelength UV/vis absorption and fluorescence detector for biological and chemical contamination

    E-Print Network [OSTI]

    Lu, Peter J.

    We present a portable multi-channel, multi-sample UV/vis absorption and fluorescence detection device, which has no moving parts, can operate wirelessly and on batteries, interfaces with smart mobile phones or tablets, and ...

  15. Investigation of measuring hazardous substances in printed circuit boards using the micro-focus X-ray fluorescence screening

    E-Print Network [OSTI]

    Fu, M L; Fakhrtdinov, R; Grigoriev, M; Quan, B S; Le, Z C; Roshchupkin, D

    2014-01-01

    Printed circuit boards (PCBs) are widely used in most electrical and electronic equipments or products. Hazardous substances such as Pb, Hg, Cd, etc, can be present in high concentrations in PCBs and the degradation and release of these substances poses a huge threat to humans and the environment. To investigation the chemical composition of PCBs in domestic market of China, a practical micro-focus X-ray fluorescence system is setup to make the elements analysis, especially for detecting hazardous substances. Collimator is adopted to focus the X-ray emitted from X-ray tube. BRUKER X-ray detector with proportional counter is used to detect the emitted fluorescence from the PCB samples. Both single layer PCB samples and double layers PCB samples made of epoxy glass fiber are purchased from the domestic market of China. Besides, a MC55 wireless communication module made by SIEMENS in Germany is used as the reference material. Experimental results from the fluorescence spectrums of the testing points of PCB sampl...

  16. X-ray crystal structure and properties of Phanta, a weakly fluorescent photochromic GFP-like protein

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Paul, Craig Don; Traore, Daouda A. K.; Olsen, Seth; Devenish, Rodney J.; Close, Devin W.; Bell, Toby D. M.; Bradbury, Andrew; Wilce, Matthew C. J.; Prescott, Mark

    2015-04-29

    Phanta is a reversibly photoswitching chromoprotein (?F, 0.003), useful for pcFRET, that was isolated from a mutagenesis screen of the bright green fluorescent eCGP123 (?F, 0.8). We have investigated the contribution of substitutions at positions His193, Thr69 and Gln62, individually and in combination, to the optical properties of Phanta. Single amino acid substitutions at position 193 resulted in proteins with very low ?F, indicating the importance of this position in controlling the fluorescence efficiency of the variant proteins. The substitution Thr69Val in Phanta was important for supressing the formation of a protonated chromophore species observed in some His193 substituted variants,more »whereas the substitution Gln62Met did not significantly contribute to the useful optical properties of Phanta. X-ray crystal structures for Phanta (2.3 Å), eCGP123T69V (2.0 Å) and eCGP123H193Q (2.2 Å) in their non-photoswitched state were determined, revealing the presence of a cis-coplanar chromophore. We conclude that changes in the hydrogen-bonding network supporting the cis-chromophore, and its contacts with the surrounding protein matrix, are responsible for the low fluorescence emission of eCGP123 variants containing a His193 substitution.« less

  17. Structural and dynamic changes associated with beneficial engineered single-amino-acid deletion mutations in enhanced green fluorescent protein

    SciTech Connect (OSTI)

    Arpino, James A. J. [Cardiff University, Park Place, Cardiff CF10 3AT Wales (United Kingdom); Rizkallah, Pierre J., E-mail: rizkallahp@cardiff.ac.uk [Cardiff University, Heath Park, Cardiff CF14 4XN Wales (United Kingdom); Jones, D. Dafydd, E-mail: rizkallahp@cardiff.ac.uk [Cardiff University, Park Place, Cardiff CF10 3AT Wales (United Kingdom)

    2014-08-01

    The beneficial engineered single-amino-acid deletion variants EGFP{sup D190?} and EGFP{sup A227?} have been studied. Single-amino-acid deletions are a common part of the natural evolutionary landscape but are rarely sampled during protein engineering owing to limited and prejudiced molecular understanding of mutations that shorten the protein backbone. Single-amino-acid deletion variants of enhanced green fluorescent protein (EGFP) have been identified by directed evolution with the beneficial effect of imparting increased cellular fluorescence. Biophysical characterization revealed that increased functional protein production and not changes to the fluorescence parameters was the mechanism that was likely to be responsible. The structure EGFP{sup D190?} containing a deletion within a loop revealed propagated changes only after the deleted residue. The structure of EGFP{sup A227?} revealed that a ‘flipping’ mechanism was used to adjust for residue deletion at the end of a ?-strand, with amino acids C-terminal to the deletion site repositioning to take the place of the deleted amino acid. In both variants new networks of short-range and long-range interactions are generated while maintaining the integrity of the hydrophobic core. Both deletion variants also displayed significant local and long-range changes in dynamics, as evident by changes in B factors compared with EGFP. Rather than being detrimental, deletion mutations can introduce beneficial structural effects through altering core protein properties, folding and dynamics, as well as function.

  18. Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury

    E-Print Network [OSTI]

    Jia, Songtao

    home's electric bill. ENERGY STAR qualified CFLs use up to 75 percent less energy than incandescent, in one year it would save enough energy to light more than 3 million homes and prevent greenhouse gas, accessible change every American can make right now to reduce energy use at home and prevent greenhouse gas

  19. Have You Switched to Compact Fluorescent Lights? Why or Why Not? |

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nA Guide to TappingWORK BREAKDOWN STRUCTUREDepartmentWalkersharedEnergy

  20. DOE Withdraws the Energy Star Label from 34 Compact Fluorescent Light Bulbs

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department8, 2015 GATEWAY Takes 9. TechnologyDOE Web| Department of

  1. Crystallographic study of red fluorescent protein eqFP578 and its far-red variant Katushka reveals opposite pH-induced isomerization of chromophore

    SciTech Connect (OSTI)

    Pletneva, Nadya V.; Pletnev, Vladimir Z.; Shemiakina, Irina I.; Chudakov, Dmitriy M.; Artemyev, Igor; Wlodawer, Alexander; Dauter, Zbigniew; Pletnev, Sergei (Russ. Acad. Sci.); (SAIC); (NCI)

    2012-08-10

    The wild type red fluorescent protein eqFP578 (from sea anemone Entacmaea quadricolor, {lambda}{sub ex} = 552 nm, {lambda}{sub em} = 578 nm) and its bright far-red fluorescent variant Katushka ({lambda}{sub ex} = 588 nm, {lambda}{sub em} = 635 nm) are characterized by the pronounced pH dependence of their fluorescence. The crystal structures of eqFP578f (eqFP578 with two point mutations improving the protein folding) and Katushka have been determined at the resolution ranging from 1.15 to 1.85 {angstrom} at two pH values, corresponding to low and high level of fluorescence. The observed extinguishing of fluorescence upon reducing pH in eqFP578f and Katushka has been shown to be accompanied by the opposite trans-cis and cis-trans chromophore isomerization, respectively. Asn143, Ser158, His197 and Ser143, Leu174, and Arg197 have been shown to stabilize the respective trans and cis fluorescent states of the chromophores in eqFP578f and Katushka at higher pH. The cis state has been suggested as being primarily responsible for the observed far-red shift of the emission maximum of Katushka relative to that of eqFP578f.

  2. New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.

    SciTech Connect (OSTI)

    Butterworth, A.L.; Becker, N.; Gainsforth, Z.; Lanzirotti, A.; Newville, M.; Proslier, T.; Stodolna, J.; Sutton, S.; Tyliszczak, T.; Westphal, A.J.; Zasadzinski, J. (UCB)

    2012-03-13

    Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and 5.3.2.1 and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution better than 25 nm. Limiting factors for Stardust STXM analyses were self-imposed limits of photon dose due to radiation damage concerns, and significant attenuation of <1500 eV X-rays by {approx}80{micro}m thick, {approx}25 mg/cm{sup 3} density silica aerogel capture medium. In practice, the ISPE team characterized the major, light elements using STXM (O, Mg, Al, Si) and the heavier minor and trace elements using SXRF. The two data sets overlapped only with minor Fe and Ni ({approx}1% mass abundance), providing few quantitative cross-checks. New improved standards for cross calibration are essential for consortium-based analyses of Stardust interstellar and cometary particles, IDPs. Indeed, they have far reaching application across the whole synchrotron-based analytical community. We have synthesized three ALD multilayers simultaneously on silicon nitride membranes and silicon and characterized them using RBS (on Si), XRF (on Si{sub 3}N{sub 4}) and STXM/XAS (holey Si{sub 3}N{sub 4}). The systems we have started to work with are Al-Zn-Fe and Y-Mg-Er. We have found these ALD multi-layers to be uniform at {micro}m- to nm scales, and have found excellent consistency between four analytical techniques so far. The ALD films can also be used as a standard for e-beam instruments, eg., TEM EELS or EDX. After some early issues with the consistency of coatings to the back-side of the membrane windows, we are confident to be able to show multi-analytical agreement to within 10%. As the precision improves, we can use the new standards to verify or improve the tabulated cross-sections.

  3. Project Title: Radiochemical Analysis by High Sensitivity Dual-Optic Micro X-ray Fluorescence

    SciTech Connect (OSTI)

    Havrilla, George J.; Gao, Ning

    2002-06-01

    A novel dual-optic micro X-ray fluorescence instrument will be developed to do radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford. This concept incorporates new X-ray optical elements such as monolithic polycapillaries and double bent crystals, which focus X-rays. The polycapillary optic can be used to focus X-rays emitted by the X-ray tube thereby increasing the X-ray flux on the sample over 1000 times. Polycapillaries will also be used to collect the X-rays from the excitation site and screen the radiation background from the radioactive species in the specimen. This dual-optic approach significantly reduces the background and increases the analyte signal thereby increasing the sensitivity of the analysis. A doubly bent crystal used as the focusing optic produces focused monochromatic X-ray excitation, which eliminates the bremsstrahlung background from the X-ray source. The coupling of the doubly bent crystal for monochromatic excitation with a polycapillary for signal collection can effectively eliminate the noise background and radiation background from the specimen. The integration of these X-ray optics increases the signal-to-noise and thereby increases the sensitivity of the analysis for low-level analytes. This work will address a key need for radiochemical analysis of high-level waste using a non-destructive, multi-element, and rapid method in a radiation environment. There is significant potential that this instrumentation could be capable of on-line analysis for process waste stream characterization at DOE sites.

  4. Monochromatic wavelength dispersive x-ray fluorescence providing sensitive and selective detection of uranium

    SciTech Connect (OSTI)

    Havrilla, George J [Los Alamos National Laboratory; Collins, Michael L [Los Alamos National Laboratory; Montoya, Velma M [Los Alamos National Laboratory; Chen, Zewu [XOS; Wei, Fuzhong [XOS

    2010-01-01

    Monochromatic wavelength dispersive X-ray fluorescence (MWDXRF) is a sensitive and selective method for elemental compositional analyses. The basis for this instrumental advance is the doubly curved crystal (DCC) optic. Previous work has demonstrated the feasibility of sensitive trace element detection for yttrium as a surrogate for curium in aqueous solutions. Additional measurements have demonstrated similar sensitivity in several different matrix environments which attests to the selectivity of the DCC optic as well as the capabilities of the MWDXRF concept. The objective of this effort is to develop an improved Pu characterization method for nuclear fuel reprocessing plants. The MWDXRF prototype instrument is the second step in a multi-year effort to achieve an improved Pu assay. This work will describe a prototype MWDXRF instrument designed for uranium detection and characterization. The prototype consists of an X-ray tube with a rhodium anode and a DCC excitation optic incorporated into the source. The DCC optic passes the RhK{alpha} line at 20.214 keV for monochromatic excitation of the sample. The source is capable of 50 W power at 50 kV and 1.0 mA operation. The x-ray emission from the sample is collected by a DCC optic set at the UL{alpha} line of 13.613 keV. The collection optic transmits the UL{alpha} x-rays to the silicon drift detector. The x-ray source, sample, collection optic and detector are all mounted on motion controlled stages for the critical alignment of these components. The sensitivity and selectivity of the instrument is obtained through the monochromatic excitation and the monochromatic detection. The prototype instrument performance has a demonstrated for sensitivity for uranium detection of around 2 ppm at the current state of development. Further improvement in sensitivity is expected with more detailed alignment.

  5. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    SciTech Connect (OSTI)

    Degueldre, Claude Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

    2013-06-01

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O? lattice in an irradiated (60 MW d kg?¹) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (~0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am³? species within an [AmO?]¹³? coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix. - Graphical abstract: Americium LIII XAFS spectra recorded for the irradiated MOX sub-sample in the rim zone for a 300 ?m×300 ?m beam size area investigated over six scans of 4 h. The records remain constant during multi-scan. The analysis of the XAFS signal shows that Am is found as trivalent in the UO? matrix. This analytical work shall open the door of very challenging analysis (speciation of fission product and actinides) in irradiated nuclear fuels. - Highlights: • Americium was characterized by microX-ray absorption spectroscopy in irradiated MOX fuel. • The americium redox state as determined from XAS data of irradiated fuel material was Am(III). • In the sample, the Am³? face an AmO?¹³?coordination environment in the (Pu,U)O? matrix. • The americium dioxide is reduced by the uranium dioxide matrix.

  6. THE SAP3 COMPUTER PROGRAM FOR QUANTITATIVE MULTIELEMENT ANALYSIS BY ENERGY DISPERSIVE X-RAY FLUORESCENCE

    SciTech Connect (OSTI)

    Nielson, K. K.; Sanders, R. W.

    1982-04-01

    SAP3 is a dual-function FORTRAN computer program which performs peak analysis of energy-dispersive x-ray fluorescence spectra and then quantitatively interprets the results of the multielement analysis. It was written for mono- or bi-chromatic excitation as from an isotopic or secondary excitation source, and uses the separate incoherent and coherent backscatter intensities to define the bulk sample matrix composition. This composition is used in performing fundamental-parameter matrix corrections for self-absorption, enhancement, and particle-size effects, obviating the need for specific calibrations for a given sample matrix. The generalized calibration is based on a set of thin-film sensitivities, which are stored in a library disk file and used for all sample matrices and thicknesses. Peak overlap factors are also determined from the thin-film standards, and are stored in the library for calculating peak overlap corrections. A detailed description is given of the algorithms and program logic, and the program listing and flow charts are also provided. An auxiliary program, SPCAL, is also given for use in calibrating the backscatter intensities. SAP3 provides numerous analysis options via seventeen control switches which give flexibility in performing the calculations best suited to the sample and the user needs. User input may be limited to the name of the library, the analysis livetime, and the spectrum filename and location. Output includes all peak analysis information, matrix correction factors, and element concentrations, uncertainties and detection limits. Twenty-four elements are typically determined from a 1024-channel spectrum in one-to-two minutes using a PDP-11/34 computer operating under RSX-11M.

  7. Compact

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the following comments responseScienceCommunity RelationsCompact soft x-ray

  8. Fluorescence spectra and biological activity of aerosolized bacillus spores and MS2 bacteriophage exposed to ozone at different relative humidities in a rotating drum

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ratnesar-Shumate, Shanna; Pan, Yong-Le; Hill, Steven C.; Kinahan, Sean; Corson, Elizabeth; Eshbaugh, Jonathan; Santarpia, Joshua L.

    2015-10-14

    Biological aerosols (bioaerosols) released into the environment may undergo physical and chemical transformations when exposed to atmospheric constituents such as solar irradiation, reactive oxygenated species, ozone, free radicals, water vapor and pollutants. Aging experiments were performed in a rotating drum chamber subjecting bioaerosols, Bacillus thuringiensis Al Hakam (BtAH) spores and MS2 bacteriophages to ozone at 0 and 150 ppb, and relative humidities (RH) at 10%, 50%, and 80+%. Fluorescence spectra and intensities of the aerosols as a function of time in the reaction chamber were measured with a single particle fluorescence spectrometer (SPFS) and an Ultra-Violet Aerodynamic Particle Sizer® Spectrometermore »(UV-APS). Losses in biological activity were measured by culture and quantitative polymerase chain reaction (q-PCR) assay. For both types of aerosols the largest change in fluorescence emission was between 280 and 400 nm when excited at 263 nm followed by fluorescence emission between 380 and 700 nm when excited at 351 nm. The fluorescence for both BtAH and MS2 were observed to decrease significantly at high ozone concentration and high RH when excited at 263 nm excitation. The decreases in 263 nm excited fluorescence are indicative of hydrolysis and oxidation of tryptophan in the aerosols. Fluorescence measured with the UV-APS (355-nm excitation) increased with time for both BtAH and MS2 aerosols. A two log loss of MS2 bacteriophage infectivity was observed in the presence of ozone at ~50% and 80% RH when measured by culture and normalized for physical losses by q-PCR. Viability of BtAH spores after exposure could not be measured due to the loss of genomic material during experiments, suggesting degradation of extracelluar DNA attributable to oxidation. The results of these studies indicate that the physical and biological properties of bioaerosols change significantly after exposure to ozone and water vapor.« less

  9. Detection limits for actinides in a monochromatic, wavelength-dispersive x-ray fluorescence instrument

    SciTech Connect (OSTI)

    Collins, Michael L [Los Alamos National Laboratory; Havrilla, George J [Los Alamos National Laboratory

    2009-01-01

    Recent developments in x-ray optics have made it possible to examine the L x-rays of actinides using doubly-curved crystals in a bench-top device. A doubly-curved crystal (DCC) acts as a focusing monochromatic filter for polychromatic x-rays. A Monochromatic, Wavelength-Dispersive X-Ray Fluorescence (MWDXRF) instrument that uses DCCs to measure Cm and Pu in reprocessing plant liquors was proposed in 2007 by the authors at Los Alamos National Laboratory. A prototype design of this MWDXRF instrument was developed in collaboration with X-ray Optical Systems Inc. (XOS), of East Greenbush, New York. In the MWDXRF instrument, x-rays from a Rhodium-anode x-ray tube are passed through a primary DCC to produce a monochromatic beam of 20.2-keV photons. This beam is focused on a specimen that may contain actinides. The 20.2-keV interrogating beam is just above the L3 edge of Californium; each actinide (with Z = 90 to 98) present in the specimen emits characteristic L x-rays as the result of L3-shell vacancies. In the LANL-XOS prototype MWDXRf, these x-rays enter a secondary DCC optic that preferentially passes 14.961-keV photons, corresponding to the L-alpha-1 x-ray peak of Curium. In the present stage of experimentation, Curium-bearing specimens have not been analyzed with the prototype MWDXRF instrument. Surrogate materials for Curium include Rubidium, which has a K-beta-l x-ray at 14.961 keV, and Yttrium, which has a K-alpha-1 x-ray at 14.958 keV. In this paper, the lower limit of detection for Curium in the LANL-XOS prototype MWDXRF instrument is estimated. The basis for this estimate is described, including a description of computational models and benchmarking techniques used. Detection limits for other actinides are considered, as well as future safeguards applications for MWDXRF instrumentation.

  10. In-situ stoichiometry determination using x-ray fluorescence generated by reflection-high-energy-electron-diffraction

    SciTech Connect (OSTI)

    Keenan, Cameron; Chandril, Sandeep; Lederman, David [Department of Physics and Multifunctional Materials Laboratory, West Virginia University, Morgantown, West Virginia 26506 (United States); Myers, T. H. [Department of Physics and Multifunctional Materials Laboratory, West Virginia University, Morgantown, West Virginia 26506 (United States); Materials Science, Engineering, and Commercialization Program, Texas State University-San Marcos, San Marcos, Texas 78666 (United States)

    2011-06-01

    A major challenge in the stoichiometric growth of complex oxide compounds is the control of the relative compositions of the constituent materials. A potential avenue for compositional analysis during growth is the use of x-ray fluorescence generated during reflection high energy electron diffraction measurements. Using this technique, relative compositions of Y and Mn in molecular beam epitaxy grown YMnO{sub 3} samples were studied. Comparing the results with Rutherford back scattering spectroscopy suggests that the technique has the potential for real-time analysis of elemental fluxes and stoichiometry control during sample growth.

  11. A survey for Fe 6.4 keV emission in young stellar objects in rho Oph: the strong fluorescence from Elias 29

    E-Print Network [OSTI]

    Favata, F; Silva, B; Sciortino, S; Tsujimoto, M

    2004-01-01

    We report the results of a search for 6.4 keV Fe fluorescent emission in Young Stellar Objects (YSOs) with measured accretion luminosities in the rho Oph cloud, using all existing chandra and XMM-Newton observations of the region. A total of nine such YSOs have X-ray data with sufficiently high S/N for the 6.4 keV line to be potentially detected if present. A positive detection of the Fe 6.4 keV line is reported for one object, Elias 29, in both the XMM-Newton and the chandra data. The 6.4 keV line is detected in Elias 29 both during quiescent and flaring emission, unlikely all previously reported detections of 6.4 keV Fe fluorescence in YSOs which were made during intense flaring. The observed equivalent width of the fluorescent line is large, at W_alpha approx 140 eV, ruling out fluorescence from diffuse circumstellar material. It is also larger than expected for simple reflection from a solar-composition photosphere or circumstellar disk, but it is compatible with being due to fluorescence from a centrally...

  12. A survey for Fe 6.4 keV emission in young stellar objects in rho Oph: the strong fluorescence from Elias 29

    E-Print Network [OSTI]

    F. Favata; G. Micela; B. Silva; S. Sciortino; M. Tsujimoto

    2004-12-20

    We report the results of a search for 6.4 keV Fe fluorescent emission in Young Stellar Objects (YSOs) with measured accretion luminosities in the rho Oph cloud, using all existing chandra and XMM-Newton observations of the region. A total of nine such YSOs have X-ray data with sufficiently high S/N for the 6.4 keV line to be potentially detected if present. A positive detection of the Fe 6.4 keV line is reported for one object, Elias 29, in both the XMM-Newton and the chandra data. The 6.4 keV line is detected in Elias 29 both during quiescent and flaring emission, unlikely all previously reported detections of 6.4 keV Fe fluorescence in YSOs which were made during intense flaring. The observed equivalent width of the fluorescent line is large, at W_alpha approx 140 eV, ruling out fluorescence from diffuse circumstellar material. It is also larger than expected for simple reflection from a solar-composition photosphere or circumstellar disk, but it is compatible with being due to fluorescence from a centrally illuminated circumstellar disk. The X-ray spectrum of Elias 29 is also peculiar in terms of its high (ionized) Fe abundance, as evident from the very intense Fe xxv 6.7 keV line emission; we speculate on the possible mechanism leading to the observed high abundance.

  13. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; et al

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologicallymore »important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.« less

  14. Phase-resolved nanosecond spectrofluorometry: theory, instrumentation, and new applications of multicomponent analysis by subnanosecond fluorescence lifetimes

    SciTech Connect (OSTI)

    Mattheis, J.R.; Mitchell, G.W.; Spencer, R.D.

    1982-03-01

    We describe a new method, phase-resolved subnanosecond spectroscopy (PRS), for the spectral differentiation of fluorophores in a mixture. The technique required adding a phase-variable rectifying detector to the SLM 4800S phasespectrofluorometer. The theory of PRS is based on the sinusoidal fluorescence emission of a population of molecules in response to sinusodially modulated exicitation light. The total a-c fluorescence signal is passed through the phase-variable detector which nulls the emission signal of any component in quadrature with the reference angle. The emission characteristics of the remaining component, or components, are more readily and accurately revealed. We investigated the sensitivity and selectivity of PRS. The sensitivity of PRS was demonstrated by nulling the contribution of the Raman scatter band of a nanomolar solution of quinine bisulfate to the real-time emission spectrum resolved at 8-nm bandpass. We demonstrated the selectivity of PRS by resolving the emission spectrum of anthracene and perylene from a 1 : 1 mixture with a lifetime differential of only 600 ps. The emission spectra of 2.2-phenylene bis-(5-phenyloxazole) and dimethyl 2.2-phenylene bis-(5-phenyloxazole) were also resolved from a 1 : 1 mixture in ethanol. The lifetime differential here was only 200 ps.

  15. Super-resolution of fluorescence-free plasmonic nanoparticles using enhanced dark-field illumination based on wavelength-modulation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Peng; Lee, Seungah; Yu, Hyunung; Fang, Ning; Ho Kang, Seong

    2015-06-15

    Super-resolution imaging of fluorescence-free plasmonic nanoparticles (NPs) was achieved using enhanced dark-field (EDF) illumination based on wavelength-modulation. Indistinguishable adjacent EDF images of 103-nm gold nanoparticles (GNPs), 40-nm gold nanorods (GNRs), and 80-nm silver nanoparticles (SNPs) were modulated at their wavelengths of specific localized surface plasmon scattering. The coordinates (x, y) of each NP were resolved by fitting their point spread functions with a two-dimensional Gaussian. The measured localization precisions of GNPs, GNRs, and SNPs were 2.5 nm, 5.0 nm, and 2.9 nm, respectively. From the resolved coordinates of NPs and the corresponding localization precisions, super-resolution images were reconstructed. Depending onmore »the spontaneous polarization of GNR scattering, the orientation angle of GNRs in two-dimensions was resolved and provided more elaborate localization information. This novel fluorescence-free super-resolution method was applied to live HeLa cells to resolve NPs and provided remarkable subdiffraction limit images.« less

  16. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

    SciTech Connect (OSTI)

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; Jacobsen, Chris; Brody, James P.

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologically important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.

  17. Nanoparticle-Based Immunochromatographic Test Strip with Fluorescent Detector for Quantification of Phosphorylated Acetycholinesterase: An Exposure Biomarker of Organophosphorous Agents

    SciTech Connect (OSTI)

    Zhang, Weiying; Ge, Xiaoxiao; Tang, Yong; Du, Dan; Liu, Deli; Lin, Yuehe

    2013-09-21

    A nanoparticle-based fluorescence immunochromatographic test strip (FITS) coupled with a hand-held detector for highly selective and sensitive detection of phosphorylated acetylcholinesterase (AChE), an exposure biomarker of organophosphate (OP) pesticides and nerve agents, is reported. In this approach, OP-AChE adducts were selectively captured by quantum dot-tagged anti-AChE antibodies (Qdot-anti-AChE) and zirconia nanoparticles (ZrO2 NPs). The sandwich-like immunoreactions were performed among the Qdot-anti-AChE, OP-AChE and ZrO2 NPs to form Qdot-anti-AChE/OP-AChE/ZrO2 complex, which was detected by recording the fluorescence intensity of Qdot captured on the test line. Paraoxon was used as the model OP pesticides. Under optimal conditions, this portable FITS immunosensor demonstrates a highly linear absorption response over the range of 0.01 nM to 10 nM OP-AChE, with a detection limit of 4 pM, coupled with a good reproducibility. Moreover, the FITS immunosensor has been validated with OP-AChE spiked human plasma samples. This is the first report on the development of ZrO2 NPs-based FITS for detection of OP-AChE adduct. The FITS immunosensor provides a sensitive and low-cost sensing platform for on-site screening/evaluating OP pesticides and nerve agents poisoning.

  18. The Energy Spectrum of Cosmic Rays above 10$^{17.2}$ eV Measured by the Fluorescence Detectors of the Telescope Array Experiment in Seven Years

    E-Print Network [OSTI]

    ,

    2015-01-01

    The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at southern two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 10$^{17.2}$ eV measured by the fluorescence detectors and a comparison with previously published results.

  19. ,,,"Incandescent","Standard Fluorescent","Compact Fluorescent","High-Intensity Discharge","Halogen"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: AlternativeMonthly","10/2015"Monthly","10/2015" ,"Release7 Relative Standard Errors for Table 5.7;" " Unit:8977.8.38.

  20. ,,,"Incandescent","Standard Fluorescent","Compact Fluorescent","High-Intensity Discharge","Halogen"

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: AlternativeMonthly","10/2015"Monthly","10/2015" ,"Release7 Relative Standard Errors for Table 5.7;" "

  1. A divergent route to core- and peripherally functionalized diazacoronenes that act as colorimetric and fluorescence proton sensors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Bo; Dai, Jing; Zherebetskyy, Danylo; Chen, Teresa L.; Zhang, Benjamin A.; Teat, Simon J.; Zhang, Qichun; Wang, Linwang; Liu, Yi

    2015-03-31

    Combining core annulation and peripheral group modification, we have demonstrated a divergent synthesis of a family of highly functionalized coronene derivatives from a readily accessible dichlorodiazaperylene intermediate. Various reactions, such as aromatic nucleophilic substitution, Kumada coupling and Suzuki coupling proceed effectively on ?-positions of the pyridine sites, giving rise to alkoxy, thioalkyl, alkyl or aryl substituted polycyclic aromatic hydrocarbons. In addition to peripheral group modulation, the aromatic core structures can be altered by annulation with thiophene or benzene ring systems. Corresponding single crystal X-ray diffraction and optical studies indicate that the heteroatom linkages not only impact the solid state packing,more »but also significantly influence the optoelectronic properties. Moreover, these azacoronene derivatives display significant acid-induced spectroscopic changes, suggesting their great potential as colorimetric and fluorescence proton sensors.« less

  2. X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gu, B.; Mishra, B.; Miller, C.; Wang, W.; Lai, B.; Brooks, S. C.; Kemner, K. M.; Liang, L.

    2014-05-23

    Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied X-ray fluorescence (XRF) microprobes to directly visualize and quantify the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg contaminated freshwater system. Up to 175 ?g g–1 Hg is found on suspended particles. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM), possibly as Hg-NOM-iron oxide ternary complexes. The diatom-bound Hg is mostly found on outer surfaces of themore »cells, suggesting passive sorption of inorganic Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, is an important sink for Hg in natural aquatic environments.« less

  3. Quantifying the number of color centers in single fluorescent nanodiamonds by photon correlation spectroscopy and Monte Carlo simulation

    SciTech Connect (OSTI)

    Hui, Y.Y.; Chang, Y.-R.; Lee, H.-Y.; Chang, H.-C.; Lim, T.-S.; Fann Wunshain

    2009-01-05

    The number of negatively charged nitrogen-vacancy centers (N-V){sup -} in fluorescent nanodiamond (FND) has been determined by photon correlation spectroscopy and Monte Carlo simulations at the single particle level. By taking account of the random dipole orientation of the multiple (N-V){sup -} fluorophores and simulating the probability distribution of their effective numbers (N{sub e}), we found that the actual number (N{sub a}) of the fluorophores is in linear correlation with N{sub e}, with correction factors of 1.8 and 1.2 in measurements using linearly and circularly polarized lights, respectively. We determined N{sub a}=8{+-}1 for 28 nm FND particles prepared by 3 MeV proton irradiation.

  4. Real-time method and apparatus for measuring the decay-time constant of a fluorescing phosphor

    DOE Patents [OSTI]

    Britton, Jr., Charles L. (Alcoa, TN); Beshears, David L. (Knoxville, TN); Simpson, Marc L. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Allison, Steve W. (Knoxville, TN)

    1999-01-01

    A method for determining the decay-time constant of a fluorescing phosphor is provided, together with an apparatus for performing the method. The apparatus includes a photodetector for detecting light emitted by a phosphor irradiated with an excitation pulse and for converting the detected light into an electrical signal. The apparatus further includes a differentiator for differentiating the electrical signal and a zero-crossing discrimination circuit that outputs a pulse signal having a pulse width corresponding to the time period between the start of the excitation pulse and the time when the differentiated electrical signal reaches zero. The width of the output pulse signal is proportional to the decay-time constant of the phosphor.

  5. A divergent route to core- and peripherally functionalized diazacoronenes that act as colorimetric and fluorescence proton sensors

    SciTech Connect (OSTI)

    He, Bo; Dai, Jing; Zherebetskyy, Danylo; Chen, Teresa L.; Zhang, Benjamin A.; Teat, Simon J.; Zhang, Qichun; Wang, Linwang; Liu, Yi

    2015-03-31

    Combining core annulation and peripheral group modification, we have demonstrated a divergent synthesis of a family of highly functionalized coronene derivatives from a readily accessible dichlorodiazaperylene intermediate. Various reactions, such as aromatic nucleophilic substitution, Kumada coupling and Suzuki coupling proceed effectively on ?-positions of the pyridine sites, giving rise to alkoxy, thioalkyl, alkyl or aryl substituted polycyclic aromatic hydrocarbons. In addition to peripheral group modulation, the aromatic core structures can be altered by annulation with thiophene or benzene ring systems. Corresponding single crystal X-ray diffraction and optical studies indicate that the heteroatom linkages not only impact the solid state packing, but also significantly influence the optoelectronic properties. Moreover, these azacoronene derivatives display significant acid-induced spectroscopic changes, suggesting their great potential as colorimetric and fluorescence proton sensors.

  6. Development of a Silicon Drift Detector Array: An X-ray Fluorescence Spectrometer for Remote Surface Mapping

    SciTech Connect (OSTI)

    Gaskin, J.A.; De Geronimo, G.; Carini, G.A.; Chen, W.; Elsner, R.F.; Kramer, G.; Keister, J.W.; Li, Z.; Ramsey, B.D.; Rehak, P.; Siddons, D.P.

    2009-09-11

    Over the past three years NASA Marshall Space Flight Center has been collaborating with Brookhaven National Laboratory to develop a modular Silicon Drift Detector (SDD) X-Ray Spectrometer (XRS) intended for fine surface mapping of the light elements of the moon. The value of fluorescence spectrometry for surface element mapping is underlined by the fact that the technique has recently been employed by three lunar orbiter missions; Kaguya, Chandrayaan-1, and Chang'e. The SDD-XRS instrument we have been developing can operate at a low energy threshold (i.e. is capable of detecting Carbon), comparable energy resolution to Kaguya (<150 eV at 5.9 keV) and an order of magnitude lower power requirement, making much higher sensitivities possible. Furthermore, the intrinsic radiation resistance of the SDD makes it useful even in radiation-harsh environments such as that of Jupiter and its surrounding moons.

  7. Time-Resolved Emission Study of a Thiophene-Modified Fluorescent Nucleoside in Solution and within Multiply-Modified Oligodeoxynucleotides

    E-Print Network [OSTI]

    Mary Noe; Yuval Erez; Itay Presiado; Yitzhak Tor; Dan Huppert

    2014-12-15

    Steady-state and time-resolved emission techniques were employed to study the photophysical properties of 5-(thien-2-yl)-2'-deoxyuridine (dUTh), an isomorphic fluorescent nucleoside analog. We found that the emission lifetime of dUTh is dependent upon the solvent viscosity and obeys the F\\"orster-Hoffman relation over a wide range of temperatures in 1-propanol, a glass-forming liquid. Upon incorporation into oligodeoxynucleotides, the average emission lifetime significantly increases, and the decay is non-exponential. We use a non-radiative decay model that takes into account the twist angle of the thiophene ring to fit the time-resolved emission decay curves.

  8. Feasibility of VHE gamma ray detection by an array of imaging atmospheric Cherenkov telescopes using the fluorescence technique

    E-Print Network [OSTI]

    Contreras, J L; Arqueros, F; López, M; Barrio, J A; Nievas, M

    2015-01-01

    The last 20 years have seen the development of new techniques in Astroparticle Physics providing access to the highest end of the electromagnetic spectrum. It has been shown that some sources emit photons up to energies close to 100 TeV. Yet the fluxes of these photons are incredibly low and new detection techniques are needed to go higher in energy. A new technique that would use the new generation of Cherenkov Telescopes, i.e., the Cherenkov Telescope Array (CTA), is proposed to push further the energy frontier. It is based on the detection of the fluorescence radiation emitted in extensive air showers, a successful method used in ultra-high-energy cosmic ray experiments, like the Pierre Auger Observatory. It would complement the standard imaging atmospheric Cherenkov technique with only minor modifications of the hardware currently being developed for the CTA and would not imply significant extra costs during its planned operation.

  9. Investigation of molecular mechanisms of action of chelating drugs on protein-lipid model membranes by X-ray fluorescence

    SciTech Connect (OSTI)

    Novikova, N. N., E-mail: nn_novikova@ns.crys.ras.ru [Kurchatov Institute, Russian Research Center (Russian Federation); Zheludeva, S. I.; Koval'chuk, M. V.; Stepina, N. D. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Erko, A. I. [Berlin Electron Storage Ring Company for Synchrotron Radiation (Germany); Yur'eva, E. A. [Ministry of Health of the Russian Federation, Moscow Research Institute of Pediatrics and Pediatric Surgery (Russian Federation)

    2009-12-15

    Protein-lipid films based on the enzyme alkaline phosphatase were subjected to the action of chelating drugs, which are used for accelerating the removal of heavy metals from the human body, and the elemental composition of the resulting films was investigated. Total-reflection X-ray fluorescence measurements were performed at the Berlin Electron Storage Ring Company for Synchrotron Radiation (BESSY) in Germany. A comparative estimation of the protective effect of four drugs (EDTA, succimer, xydiphone, and mediphon) on membrane-bound enzymes damaged by lead ions was made. The changes in the elemental composition of the protein-lipid films caused by high doses of chelating drugs were investigated. It was shown that state-of-the-art X-ray techniques can, in principle, be used to develop new methods for the in vitro evaluation of the efficiency of drugs, providing differential data on their actions.

  10. Detailed modeling and laser-induced fluorescence imaging of nitric oxide in a NH3-seeded non-premixed methane/air flame

    E-Print Network [OSTI]

    Bell, John B.

    non-premixed methane/air flame John B. Bell, Marcus S. Day, Joseph F. Grcar Computing Sciences-induced fluorescence imaging of nitric oxide in a NH3-seeded non-premixed methane/air flame Abstract In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded

  11. Conclusion: We described an efficient non-invasive benign Methods: We use fluorescent silica colloidal particles of method to quantify dynamics and to perform mapping of

    E-Print Network [OSTI]

    Sokolov, Igor

    products, we use two base materials: either glycerin or vaseline. A mixture of each Key words: skin care products product with fluorescent particles is applied on human skin. spectroscopy The amount the outside environment. It protects protective oil layer from the skin. This results in the body from

  12. A detailed pore characterization in 2D and 3D by means of optical and fluorescence microscopy combined with high-resolution X-ray CT.

    E-Print Network [OSTI]

    Gent, Universiteit

    A detailed pore characterization in 2D and 3D by means of optical and fluorescence microscopy structure. However, the evolution of techniques like X-ray CT has enabled us to make non-destructive 3D images of materials and thus of rocks. 3D image analysis software enables us to characterize the pore

  13. Bayesian analysis of fluorescence lifetime imaging data Mark I Rowleya, Paul R Barbera,b, Anthony CC Coolena and Borivoj Vojnovica,b

    E-Print Network [OSTI]

    Coolen, ACC "Ton"

    Biophysics, Guy's Campus, London, SE1 1UL, UK; bUniversity of Oxford, Gray Institute for Radiation Oncology count data, obtained by imaging human epithelial carcinoma cells expressing cdc42-GFP, Bayesian analysis acquisition in experiments that use Fluorescence Lifetime Imaging Microscopy (FLIM), permitting the accurate

  14. 2014-04-11 Issuance: Energy Conservation Standards for General Service Fluorescent Lamps and Incandescent Reflector Lamps; Notice of Proposed Rulemaking

    Broader source: Energy.gov [DOE]

    This document is a pre-publication Federal Register notice of proposed rulemaking regarding energy conservation standards for general service fluorescent lamps and incandescent reflectors lamps, as issued by the Assistant Secretary for Energy Efficiency and Renewable Energy on April 11, 2014.

  15. Research and Development of a New Field Enhanced Low Temperature Thermionic Cathode that Enables Fluorescent Dimming and Loan Shedding without Auxiliary Cathode Heating

    SciTech Connect (OSTI)

    Feng Jin

    2009-01-07

    This is the final report for project entitled 'Research and development of a new field enhanced low temperature thermionic cathode that enables fluorescent dimming and load shedding without auxiliary cathode heating', under Agreement Number: DE-FC26-04NT-42329. Under this project, a highly efficient CNT based thermionic cathode was demonstrated. This cathode is capable of emitting electron at a current density two order of magnitude stronger then a typical fluorescent cathode at same temperatures, or capable of emitting at same current density but at temperature about 300 C lower than that of a fluorescent cathode. Detailed fabrication techniques were developed including CVD growth of CNTs and sputter deposition of oxide thin films on CNTs. These are mature technologies that have been widely used in industry for large scale materials processing and device fabrications, thus, with further development work, the techniques developed in this project can be scaled-up in manufacturing environment. The prototype cathodes developed in this project were tested in lighting plasma discharge environment. In many cases, they not only lit and sustain the plasma, but also out perform the fluorescent cathodes in key parameters such like cathode fall voltages. More work will be needed to further evaluate more detailed and longer term performance of the prototype cathode in lighting plasma.

  16. Directional Fluorescence Spectra of Laser Dye in Opal and Inverse Opal Photonic Crystals Lydia Bechger,* Peter Lodahl, and Willem L. Vos

    E-Print Network [OSTI]

    Vos, Willem L.

    Directional Fluorescence Spectra of Laser Dye in Opal and Inverse Opal Photonic Crystals Lydia polystyrene opals and alumina inverse opals are studied, allowing us to compare direct and inverted structures emission was first reported in refs 6 and 7: titania inverse opals doped with laser dye showed a broadband

  17. Significance of Cytochrome P450 System Responses and Levels of Bile Fluorescent Aromatic Compounds in Marine Wildlife Following Oil Spills

    SciTech Connect (OSTI)

    Lee, Richard F.; Anderson, Jack W.

    2005-07-01

    The relationships among cytochrome P450 induction in marine wildlife species, levels of fluorescent aromatic compounds (FAC) in their bile, the chemical composition of the inducing compounds, the significance of the exposure pathway, and any resulting injury, as a consequence of exposure to crude oil following a spill, are reviewed. Fish collected after oil spills often show increases in cytochrome P450 system activity, cytochrome P4501A (CYP1A) and bile fluorescent aromatic compounds (FAC), that are correlated with exposure to polycyclic aromatic hydrocarbons (PAH) in the oil. There is also some evidence for increases in bile FAC and induction of cytochrome P450 in marine birds and mammals after oil spills. However, when observed, increases in these exposure indicators are transitory and generally decrease to background levels within one year after the exposure. Laboratory studies have shown induction of cytochrome P450 systems occurs after exposure of fish to crude oil in water, sediment or food. Most of the PAH found in crude oil (dominantly 2- and 3-ring PAH) are not strong inducers of cytochrome P450. Exposure to the 4-ring chrysenes or the photooxidized products of the PAH may account for the cytochrome P450 responses in fish collected from oil-spill sites. The contribution of non-spill background PAH, particularly combustion-derived (pyrogenic) PAH, to bile FAC and cytochrome P450 system responses can be confounding and needs to be considered when evaluating oil spill effects. The ubiquity of pyrogenic PAH makes it important to fully characterize all sources of PAH, including PAH from natural resources, e.g. retene, in oil spill studies. In addition, such parameters as species, sex, age, ambient temperature and season need to be taken into account. While increases in fish bile FAC and cytochrome P450 system responses, can together, be sensitive general indicators of PAH exposure after an oil spill, there is little unequivocal evidence to suggest a linkage to higher order biological effects, e.g. toxicity, lesions, reproductive failure.

  18. Spectroscopy of the D1-transition of cesium by dressed-state resonance fluorescence from a single (In,Ga)As/GaAs quantum dot

    E-Print Network [OSTI]

    Ulrich, S M; Oster, M; Jetter, M; Urvoy, A; Löw, R; Michler, P

    2014-01-01

    We use a laser-driven single (In,Ga)As quantum dot (QD) in the dressed state regime of resonance fluorescence ($T = 4$ K) to observe the four $D_1$-transition lines of alkali atomic cesium ($Cs$) vapor at room temperature. We tune the frequency of the dressing continuous-wave laser in the vicinity of the bare QD resonance $\\sim 335.116$ THz ($\\sim 894.592$ nm) at constant excitation power and thereby controllably tune the center and side channel frequencies of the probe light, i.e. the Mollow triplet. Resonances between individual QD Mollow triplet lines and the atomic hyperfine-split transitions are clearly identified in the $Cs$ absorption spectrum. Our results show that narrow-band (In,Ga)As QD resonance fluorescence (RF) is suitable to optically address individual transitions of the $D_1$ quadruplet without applying magnetic field or electric field tuning.

  19. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    SciTech Connect (OSTI)

    Kayser, Y.; B?achucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-15

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.

  20. CHARACTERIZATION OF SALT PARTICLE INDUCED CORROSION PROCESSES BY SYNCHROTRON GENERATED X-RAY FLUORESCENCE AND COMPLEMENTARY SURFACE ANALYSIS TOOLS.

    SciTech Connect (OSTI)

    NEUFELD, A.K.; COLE, I.S.; BOND, A.M.; ISAACS, H.S.; FURMAN, S.A.

    2001-03-25

    The benefits of using synchrotron-generated X-rays and X-ray fluorescence analysis in combination with other surface analysis techniques have been demonstrated. In studies of salt-induced corrosion, for example, the detection of Rb ions in the area of secondary spreading when salt-containing micro-droplets are placed on zinc surfaces, further supports a mechanism involving cation transport during the corrosion and spreading of corrosive salt on exposed metal surfaces. Specifically, the new analytical data shows that: (a) cations are transported radially from a primary drop formed from a salt deposit in a thin film of secondary spreading around the drop; (b) subsequently, micro-pools are formed in the area of secondary spreading, and it is likely that cations transported within the thin film accumulate in these micro-pools until the area is dehydrated; (c) the mechanism of cation transport into the area of secondary spreading does not include transport of the anions; and (d) hydroxide is the counter ion formed from oxygen reduction at the metal surface within the spreading layer. Data relevant to iron corrosion is also presented and the distinct differences relative to the zinc situation are discussed.

  1. X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gu, B.; Mishra, B.; Miller, C.; Wang, W.; Lai, B.; Brooks, S. C.; Kemner, K. M.; Liang, L.

    2014-09-30

    Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied a synchrotron-based X-ray fluorescence (XRF) microprobe to visualize and quantify directly the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg-contaminated freshwater system. Up to 175 ?g g?1 Hg is found on suspended particles, but less than 0.01% is in the form of methylmercury. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM). The diatom-bound Hg is mostly foundmore »on outer surfaces of the cells, suggesting passive sorption of Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, may play an important role in affecting the partitioning, reactivity, and biogeochemical cycling of Hg in natural aquatic environments.« less

  2. Analysis of the methods for the derivation of binary kinetic equations in the theory of fluorescence concentration quenching

    SciTech Connect (OSTI)

    Doktorov, A. B. [Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia and Physics Department Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2014-09-14

    In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.

  3. Fluorescence Efficiency and Stability of Radio-Pure Tetraphenyl-butadiene Based Coatings for VUV Light Detection in Cryogenic Environments

    E-Print Network [OSTI]

    Baudis, Laura; Dressler, Rugard; Piastra, Francesco; Usoltsev, Ilya; Walter, Manuel

    2015-01-01

    The detection of VUV scintillation light, e.g. in (liquid) argon detectors, commonly includes a reflector with a fluorescent coating, converting UV photons to visible light. The light yield of these detectors depends directly on the conversion efficiency. Several coating/reflector combinations were produced using VM2000, a specular reflecting multi layer polymer, and Tetratex, a diffuse reflecting PTFE fabric, as reflector foils. The efficiency of these coatings was optimised and has been measured in a dedicated liquid argon setup built at the University of Zurich. It employs a small, 1.3 kg LAr cell viewed by a 3-inch, low radioactivity PMT of type R11065-10 from Hamamatsu. The cryogenic stability of these coatings was additionally studied. The optimum reflector/coating combination was found to be Tetratex dip coated with Tetraphenyl-butadiene with a thickness of 0.9 mg/cm$^2$ resulting in a 3.6 times higher light yield compared to uncoated VM2000. Its performance was stable in long term measurements, ran up...

  4. Versatile plug flow catalytic cell for in situ transmission/fluorescence x-ray absorption fine structure measurements

    SciTech Connect (OSTI)

    Centomo, P.; Zecca, M. [Dipartimento di Scienze Chimiche, via Marzolo 1, Universita degli Studi di Padova, 35131 Padova (Italy); Meneghini, C. [Dipartimento di Scienze, via della Vasca Navale 84, Universita di Roma TRE, 00146 Roma (Italy)

    2013-05-15

    A novel flow-through catalytic cell has been developed for in situ x-ray absorption spectroscopy (XAS) experiments on heterogeneous catalysts under working conditions and in the presence of a liquid and a gas phase. The apparatus allows to carry out XAS measurements in both the transmission and fluorescence modes, at moderate temperature (from RT to 50-80 Degree-Sign C) and low-medium gas pressure (up to 7-8 bars). The materials employed are compatible with several chemicals such as those involved in the direct synthesis of hydrogen peroxide (O{sub 2}, H{sub 2}, H{sub 2}O{sub 2}, methanol). The versatile design of the cell allows to fit it to different experimental setups in synchrotron radiation beamlines. It was used successfully for the first time to test nanostructured Pd catalysts during the direct synthesis of hydrogen peroxide (H{sub 2}O{sub 2}) in methanol solution from dihydrogen and dioxygen.

  5. Air fluorescence measurements in the spectral range 300-420 nm using a 28.5 GeV electron beam

    E-Print Network [OSTI]

    R. Abbasi; T. Abu-Zayyad; K. Belov; J. Belz; Z. Cao; M. Dalton; Y. Fedorova; P. Huentemeyer; B. F. Jones; C. C. H. Jui; E. C. Loh; N. Manago; K. Martens; J. N. Matthews; M. Maestas; J. Smith; P. Sokolsky; R. W. Springer; J. Thomas; S. Thomas; P. Chen; C. Field; C. Hast; R. Iverson; J. S. T. Ng; A. Odian; K. Reil; D. Walz; D. R. Bergman; G. Thomson; A. Zech; F-Y. Chang; C-C. Chen; C-W. Chen; M. A. Huang; W-Y. P. Hwang; G-L. Lin

    2007-08-23

    Measurements are reported of the yield and spectrum of fluorescence, excited by a 28.5 GeV electron beam, in air at a range of pressures of interest to ultra-high energy cosmic ray detectors. The wavelength range was 300 - 420 nm. System calibration has been performed using Rayleigh scattering of a nitrogen laser beam. In atmospheric pressure dry air at 304 K the yield is 20.8 +/- 1.6 photons per MeV.

  6. Reduced Fluorescence Quenching of Cyclodextrin-Acetylene Dye Rotaxanes Jong S. Park, James N. Wilson, Kenneth I. Hardcastle, Uwe H. F. Bunz,*, and

    E-Print Network [OSTI]

    Srinivasarao, Mohan

    are observed from the aromatic protons d and c of the dumbbell to protons H3 and H4 of the R-CD, and from b; the R-CD hovers over one end of the dye molecule, leaving the other end uncovered. Aromatic protons from, 3 exhibits higher relative fluorescence quantum yields (for FD and 3, 0.55 and 0.67 in methanol; 0

  7. Excited state carrier dynamics in CdS{sub x}Se{sub 1-x} semisconductor alloys as studied by ultrafast fluorescence spectroscopy

    SciTech Connect (OSTI)

    Gadd, S.E.

    1995-08-01

    This dissertation discusses studies of the electron-hole pair dynamics of CdS{sub x}Se{sub 1-x} semiconductor alloys for the entire compositional range from x = 1 to x = 0 as examined by the ultrafast fluorescence techniques of time correlated single photon counting and fluorescence upconversion. Specifically, samples with x = 1, .75, .5, .25, and 0 were studied each at a spread of wavelengths about its respective emission maximum which varies according to {lambda} = 718nm - 210x nm. The decays of these samples were found to obey a Kohlrausch distribution, exp [(t/{tau}){sup {beta}}], with the exponent 3 in the range .5-.7 for the alloys. These results are in agreement with those expected for localization due to local potential variations resulting from the random distribution of sulfur and selenium atoms on the element VI A sub-lattice. This localization can be understood in terms of Anderson localization of the holes in states whose energy distribution tails into the forbidden energy band-gap. Because these states have energy dependent lifetimes, the carriers can decay via many parallel channels. This distribution of channels is the ultimate source of the Kohlrausch form of the fluorescence decays.

  8. Fast methods for analysis of neurotransmitters from single cell and monitoring their releases in central nervous system by capillary electrophoresis, fluorescence microscopy and luminescence imaging

    SciTech Connect (OSTI)

    Wang, Ziqiang

    1999-12-10

    Fast methods for separation and detection of important neurotransmitters and the releases in central nervous system (CNS) were developed. Enzyme based immunoassay combined with capillary electrophoresis was used to analyze the contents of amino acid neurotransmitters from single neuron cells. The release of amino acid neurotransmitters from neuron cultures was monitored by laser induced fluorescence imaging method. The release and signal transduction of adenosine triphosphate (ATP) in CNS was studied with sensitive luminescence imaging method. A new dual-enzyme on-column reaction method combined with capillary electrophoresis has been developed for determining the glutamate content in single cells. Detection was based on monitoring the laser-induced fluorescence of the reaction product NADH, and the measured fluorescence intensity was related to the concentration of glutamate in each cell. The detection limit of glutamate is down to 10{sup {minus}8} M level, which is 1 order of magnitude lower than the previously reported detection limit based on similar detection methods. The mass detection limit of a few attomoles is far superior to that of any other reports. Selectivity for glutamate is excellent over most of amino acids. The glutamate content in single human erythrocyte and baby rat brain neurons were determined with this method and results agreed well with literature values.

  9. A QUANTUM BAND MODEL OF THE {nu}{sub 3} FUNDAMENTAL OF METHANOL (CH{sub 3}OH) AND ITS APPLICATION TO FLUORESCENCE SPECTRA OF COMETS

    SciTech Connect (OSTI)

    Villanueva, G. L.; DiSanti, M. A.; Mumma, M. J. [Solar System Exploration Division, Mailstop 690.3, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Xu, L.-H., E-mail: Geronimo.Villanueva@nasa.gov [Department of Physics and Centre for Laser, Atomic, and Molecular Sciences, University of New Brunswick, Saint John, New Brunswick E2L 4L5 (Canada)

    2012-03-01

    Methanol (CH{sub 3}OH) radiates efficiently at infrared wavelengths, dominating the C-H stretching region in comets, yet inadequate quantum-mechanical models have imposed limits on the practical use of its emission spectra. Accordingly, we constructed a new line-by-line model for the {nu}{sub 3} fundamental band of methanol at 2844 cm{sup -1} (3.52 {mu}m) and applied it to interpret cometary fluorescence spectra. The new model permits accurate synthesis of line-by-line spectra for a wide range of rotational temperatures, ranging from 10 K to more than 400 K. We validated the model by comparing simulations of CH{sub 3}OH fluorescent emission with measured spectra of three comets (C/2001 A2 LINEAR, C/2004 Q2 Machholz and 8P/Tuttle) acquired with high-resolution infrared spectrometers at high-altitude sites. The new model accurately describes the complex emission spectrum of the {nu}{sub 3} band, providing distinct rotational temperatures and production rates at greatly improved confidence levels compared with results derived from earlier fluorescence models. The new model reconciles production rates measured at infrared and radio wavelengths in C/2001 A2 (LINEAR). Methanol can now be quantified with unprecedented precision and accuracy in astrophysical sources through high-dispersion spectroscopy at infrared wavelengths.

  10. The surface structure of ?-uranophane and its interaction with Eu(III) – An integrated computational and fluorescence spectroscopy study

    SciTech Connect (OSTI)

    Kuta, Jadwiga; Wang, Zheming; Wisuri, Katy; Wander, Matthew C F.; Wall, Nathalie; Clark, Aurora E.

    2013-02-15

    Uranophane is a rare U(VI) secondary silicate mineral formed in nature by the oxidation of the primary mineral uraninite. It is also relevant to the long-term geochemistry of nuclear waste repositories, where it can be formed under oxidizing conditions and has the potential to act as a secondary barrier to the migration of radionuclides through mineral sorption reactions. A combination of classical molecular dynamics and ab-initio density functional theory (DFT) has been employed to investigate the uranophane|water interface as well as the interfacial reactivity of the U(VI) silicate toward acidic conditions and radionuclide ion sorption. The sorption simulations have been complemented by experimental sorption studies and laser induced fluorescence spectroscopy to help identify the molecular structure of the surface sorbed species. Experimental distances and essential coordination numbers are properly captured by the simulation results within bulk uranophane, while interfacial water is found to orient primarily with the hydrogen-atoms directed towards the negatively charged surface. Sorption sites for water are observed to belong to 3 different groups: (1) those involving uranyl oxygen, (2) involving uranyl and silica hydroxyl oxygen atoms, and (3) involving hydroxyl hydrogen. The pKa of the surface -OH groups have been calculated using a variety of models, including a bond valence approach and utilization of the energetics of deprotonation within DFT. Under basic conditions, deprotonation of the Si-OH groups is likely responsible for uranophane dissolution. Finally, the stability and structure of surface sorbed Eu3+ has been examined, with a stable inner-sphere species being observed.

  11. Effect of enhanced Renilla luciferase and fluorescent protein variants on the Foerster distance of Bioluminescence resonance energy transfer (BRET)

    SciTech Connect (OSTI)

    Dacres, Helen, E-mail: helen.dacres@csiro.au [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia)] [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia); Michie, Michelle; Wang, Jian [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia)] [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia); Pfleger, Kevin D.G. [Laboratory for Molecular Endocrinology-GPCRs, Western Australian Institute for Medical Research (WAIMR) and Centre for Medical Research, The University of Western Australia, Perth (Australia)] [Laboratory for Molecular Endocrinology-GPCRs, Western Australian Institute for Medical Research (WAIMR) and Centre for Medical Research, The University of Western Australia, Perth (Australia); Trowell, Stephen C. [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia)] [CSIRO Food Futures Flagship and Ecosystem Sciences, Canberra (Australia)

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer First experimental determination of Foerster distance (R{sub 0}) for enhanced BRET systems. Black-Right-Pointing-Pointer Effect of brighter BRET components RLuc2, RLuc8 and Venus was assessed. Black-Right-Pointing-Pointer Using brighter BRET components substantially increased (25%) R{sub 0} of the BRET{sup 1} system. Black-Right-Pointing-Pointer Using brighter BRET components marginally increased (2-9%) R{sub 0} of the BRET{sup 2} system. Black-Right-Pointing-Pointer Brighter BRET components improve the different weaknesses of BRET{sup 1} and BRET{sup 2} systems. -- Abstract: Bioluminescence resonance energy transfer (BRET) is an important tool for monitoring macromolecular interactions and is useful as a transduction technique for biosensor development. Foerster distance (R{sub 0}), the intermolecular separation characterized by 50% of the maximum possible energy transfer, is a critical BRET parameter. R{sub 0} provides a means of linking measured changes in BRET ratio to a physical dimension scale and allows estimation of the range of distances that can be measured by any donor-acceptor pair. The sensitivity of BRET assays has recently been improved by introduction of new BRET components, RLuc2, RLuc8 and Venus with improved quantum yields, stability and brightness. We determined R{sub 0} for BRET{sup 1} systems incorporating novel RLuc variants RLuc2 or RLuc8, in combination with Venus, as 5.68 or 5.55 nm respectively. These values were approximately 25% higher than the R{sub 0} of the original BRET{sup 1} system. R{sub 0} for BRET{sup 2} systems combining green fluorescent proteins (GFP{sup 2}) with RLuc2 or RLuc8 variants was 7.67 or 8.15 nm, i.e. only 2-9% greater than the original BRET{sup 2} system despite being {approx}30-fold brighter.

  12. SU-E-T-20: A Novel Hybrid CBCT, Bioluminescence and Fluorescence Tomography System for Preclinical Radiation Research

    SciTech Connect (OSTI)

    Zhang, B; Eslami, S; Iordachita, I; Yang, Y; Patterson, M; Wong, J; Wang, K

    2014-06-01

    Purpose: A novel standalone bioluminescence and fluorescence tomography (BLT and FT) system equipped with high resolution CBCT has been built in our group. In this work, we present the system calibration method and validate our system in both phantom and in vivo environment. Methods: The CBCT is acquired by rotating the animal stage while keeping the x-ray source and detector panel static. The optical signal is reflected by the 3-mirror system to a multispectral filter set and then delivered to the CCD camera with f/1.4 lens mounted. Nine fibers passing through the stage and in contact with the mouse skin serve as the light sources for diffuse optical tomography (DOT) and FT. The anatomical information and optical properties acquired from the CBCT and DOT, respectively, are used as the priori information to improve the BLT/FT reconstruction accuracy. Flat field correction for the optical system was acquired at multiple wavelengths. A home-built phantom is used to register the optical and CBCT coordinates. An absolute calibration relating the CCD photon counts rate to the light fluence rate emitted at animal surface was developed to quantify the bioluminescence power or fluorophore concentration. Results: An optical inhomogeneous phantom with 2 light sources (3mm separation) imbedded is used to test the system. The optical signal is mapped onto the mesh generated from CBCT for optical reconstruction. Our preliminary results show that the center of mass can be reconstructed within 2.8mm accuracy. A live mouse with the light source imbedded is also used to validate our system. Liver or lung metastatic luminescence tumor model will be used for further testing. Conclusion: This hybrid system transforms preclinical research to a level that even sub-palpable volume of cells can be imaged rapidly and non-invasively, which largely extends the scope of radiobiological research. The research is supported by the NCI grant R01CA158100-01.

  13. Multiphoton Add fluorescent dye

    E-Print Network [OSTI]

    Braun, Paul

    of aperiodic defect structures within 3D PBG materials. While this has been accomplished, for example, via at Urbana-Champaign, Urbana, IL 61801 INTRODUCTION Three-dimensional (3D) photonic bandgap (PBG) materials postulated as the basis of a number of optical devices. 1-3 A prime advantage of 3D PBG devices

  14. Fluorescence based biosensor

    DOE Patents [OSTI]

    Lu,Yi (Champaign, IL); Liu, uewen (Urbana, IL)

    2011-10-25

    A novel biosensor comprises at least one fluorophore and at least two quenchers, and is capable of selectively and specifically detecting the presence of an ion in the presence of other ions.

  15. Coherence in parametric fluorescence

    E-Print Network [OSTI]

    T. Onodera; Marco Liscidini; J. E. Sipe; L. G. Helt

    2015-09-10

    We investigate spontaneous four wave mixing (SFWM) in a single-channel side-coupled integrated spaced sequence of resonators (SCISSOR). Analytic expressions for the number of photon pairs generated, as well as the biphoton wave function (joint spectral amplitude) describing the pairs, are derived and numerically computed for different pump pulse durations and numbers of ring resonators. In the limit of a long input pump pulse, we show a strong analogy between super-linear scaling of generation efficiency with respect to the number of rings in the structure and Dicke superradiance. More generally, we discuss in detail the factors that influence the shape of the biphoton wave function, as well as the conditions for observing super-SFWM.

  16. Fluorescent CdSe/ZnS nanocrystal-peptide conjugates for long-term, nontoxic imaging and nuclear targeting in living cells

    SciTech Connect (OSTI)

    Chen, Fanqing; Gerion, Daniele

    2004-06-14

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. However, most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells ha s not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of commonly used cell transfection techniques for qdots, we were able to introduce and retain the NLS-qdots conjugate in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS nanocrystal-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for cell nuclear processes.

  17. Structure of the red fluorescent protein from a lancelet (Branchiostoma lanceolatum): a novel GYG chromophore covalently bound to a nearby tyrosine

    SciTech Connect (OSTI)

    Pletnev, Vladimir Z., E-mail: vzpletnev@gmail.com; Pletneva, Nadya V.; Lukyanov, Konstantin A.; Souslova, Ekaterina A.; Fradkov, Arkady F.; Chudakov, Dmitry M.; Chepurnykh, Tatyana; Yampolsky, Ilia V. [Russian Academy of Sciences, Moscow (Russian Federation); Wlodawer, Alexander [National Cancer Institute, Frederick, MD 21702 (United States); Dauter, Zbigniew [National Cancer Institute, Argonne, IL 60439 (United States); Pletnev, Sergei, E-mail: vzpletnev@gmail.com [National Cancer Institute, Argonne, IL 60439 (United States); SAIC-Frederick, Argonne, IL 60439 (United States); Russian Academy of Sciences, Moscow (Russian Federation)

    2013-09-01

    The crystal structure of the novel red emitting fluorescent protein from lancelet Branchiostoma lanceolatum (Chordata) revealed an unusual five residues cyclic unit comprising Gly58-Tyr59-Gly60 chromophore, the following Phe61 and Tyr62 covalently bound to chromophore Tyr59. A key property of proteins of the green fluorescent protein (GFP) family is their ability to form a chromophore group by post-translational modifications of internal amino acids, e.g. Ser65-Tyr66-Gly67 in GFP from the jellyfish Aequorea victoria (Cnidaria). Numerous structural studies have demonstrated that the green GFP-like chromophore represents the ‘core’ structure, which can be extended in red-shifted proteins owing to modifications of the protein backbone at the first chromophore-forming position. Here, the three-dimensional structures of green laGFP (?{sub ex}/?{sub em} = 502/511 nm) and red laRFP (?{sub ex}/?{sub em} ? 521/592 nm), which are fluorescent proteins (FPs) from the lancelet Branchiostoma lanceolatum (Chordata), were determined together with the structure of a red variant laRFP-?S83 (deletion of Ser83) with improved folding. Lancelet FPs are evolutionarily distant and share only ?20% sequence identity with cnidarian FPs, which have been extensively characterized and widely used as genetically encoded probes. The structure of red-emitting laRFP revealed three exceptional features that have not been observed in wild-type fluorescent proteins from Cnidaria reported to date: (i) an unusual chromophore-forming sequence Gly58-Tyr59-Gly60, (ii) the presence of Gln211 at the position of the conserved catalytic Glu (Glu222 in Aequorea GFP), which proved to be crucial for chromophore formation, and (iii) the absence of modifications typical of known red chromophores and the presence of an extremely unusual covalent bond between the Tyr59 C{sup ?} atom and the hydroxyl of the proximal Tyr62. The impact of this covalent bond on the red emission and the large Stokes shift (?70 nm) of laRFP was verified by extensive structure-based site-directed mutagenesis.

  18. High energy resolution five-crystal spectrometer for high quality fluorescence and absorption measurements on an x-ray absorption spectroscopy beamline

    SciTech Connect (OSTI)

    Llorens, Isabelle; Lahera, Eric; Delnet, William; Proux, Olivier; Dermigny, Quentin; Gelebart, Frederic; Morand, Marc; Shukla, Abhay; Bardou, Nathalie; Ulrich, Olivier; and others

    2012-06-15

    Fluorescence detection is classically achieved with a solid state detector (SSD) on x-ray absorption spectroscopy (XAS) beamlines. This kind of detection however presents some limitations related to the limited energy resolution and saturation. Crystal analyzer spectrometers (CAS) based on a Johann-type geometry have been developed to overcome these limitations. We have tested and installed such a system on the BM30B/CRG-FAME XAS beamline at the ESRF dedicated to the structural investigation of very dilute systems in environmental, material and biological sciences. The spectrometer has been designed to be a mobile device for easy integration in multi-purpose hard x-ray synchrotron beamlines or even with a laboratory x-ray source. The CAS allows to collect x-ray photons from a large solid angle with five spherically bent crystals. It will cover a large energy range allowing to probe fluorescence lines characteristic of all the elements from Ca (Z = 20) to U (Z = 92). It provides an energy resolution of 1-2 eV. XAS spectroscopy is the main application of this device even if other spectroscopic techniques (RIXS, XES, XRS, etc.) can be also achieved with it. The performances of the CAS are illustrated by two experiments that are difficult or impossible to perform with SSD and the complementarity of the CAS vs SSD detectors is discussed.

  19. Measurement of XeI and XeII velocity in the near exit plane of a low-power Hall effect thruster by light induced fluorescence spectroscopy

    SciTech Connect (OSTI)

    Dancheva, Y.; Biancalana, V.; Pagano, D.; Scortecci, F.

    2013-06-15

    Near exit plane non-resonant light induced fluorescence spectroscopy is performed in a Hall effect low-power Xenon thruster at discharge voltage of 250 V and anode flow rate of 0.7 mg/s. Measurements of the axial and radial velocity components are performed, exciting the 6s{sup 2}[3/2]{sub 2}{sup o}{yields}6p{sup 2}[3/2]{sub 2} transition at 823.16 nm in XeI and the 5d[4]{sub 7/2}{yields}6p[3]{sub 5/2}{sup o} transition at 834.724 nm in XeII. No significant deviation from the thermal velocity is observed for XeI. Two most probable ion velocities are registered at a given position with respect to the thruster axis, which are mainly attributed to different areas of creation of ions inside the acceleration channel. The spatial resolution of the set-up is limited by the laser beam size (radius of the order of 0.5 mm) and the fluorescence collection optics, which have a view spot diameter of 8 mm.

  20. Quantum dot immunoassays in renewable surface column and 96-well plate formats for the fluorescence detection of Botulinum neurotoxin using high-affinity antibodies

    SciTech Connect (OSTI)

    Warner, Marvin G.; Grate, Jay W.; Tyler, Abby J.; Ozanich, Richard M.; Miller, Keith D.; Lou, Jianlong; Marks, James D.; Bruckner-Lea, Cindy J.

    2009-09-01

    A fluorescence sandwich immunoassay using high affinity antibodies and quantum dot (QD) reporters has been developed for detection of botulinum toxin serotype A (BoNT/A). For the development of the assay, a nontoxic recombinant fragment of the holotoxin (BoNT/A-HC-fragment) has been used as a structurally valid simulant for the full toxin molecule. The antibodies used, AR4 and RAZ1, bind to nonoverlapping epitopes present on both the full toxin and on the recombinant fragment. In one format, the immunoassay is carried out in a 96-well plate with detection in a standard plate reader. Detection down to 31 pM of the BoNT/Hc-fragment was demonstrated with a total incubation time of 3 hours, using AR4 as the capture antibody and QD-coupled RAZ1 as the reporter. In a second format, the AR4 capture antibody was coupled to Sepharose beads, and the immunochemical reactions were carried out in microcentrifuge tubes with an incubation time of 1 hour. These beads were subsequently captured and concentrated in a rotating rod “renewable surface” flow cell as part of a sequential injection fluidic system. This flow cell was equipped with a fiber optic system for fluorescence measurements. In PBS buffer solution matrix, the BoNT/A-HC-fragment was detected to concentrations as low as 5 pM using the fluidic measurement approach.