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Sample records for highly resolving reonance-ionization

  1. Highly resolving computerized tomography

    International Nuclear Information System (INIS)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions. (BWU) [de

  2. Highly resolving computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, B.; Petersen, D.; Walter, E.

    1984-01-01

    With the development of highly-resolving devices for computerized tomography, CT diagnosis of the lumbar vertebral column has gained increasing importance. As an ambulatory, non-invasive method it has proved in comparative studies to be at least equivalent to myelography in the detection of dislocations of inter-vertebral disks (4,6,7,15). Because with modern devices not alone the bones, but especially the spinal soft part structures are clearly and precisely presented with a resolution of distinctly below 1 mm, a further improvement of the results is expected as experience will increase. The authors report on the diagnosis of the lumbar vertebral column with the aid of a modern device for computerized tomography and wish to draw particular attention to the possibility of doing this investigation as a routine, and to the diagnostic value of secondary reconstructions.

  3. Highly Resolved Paleoclimatic Aerosol Records

    DEFF Research Database (Denmark)

    Kettner, Ernesto

    soluble aerosols can be analysed for concentration changes only, insoluble aeolian dust can reveal additional information on its atmospheric residence time via changes in the mean grain sizes. Volumes of particulate matter in ice cores are most reliably determined with Coulter counters, but since...... a Coulter counter performs measurements on discrete samples, it cannot be connected to a CFA system. Attenuation sensors, on the other hand, can be integrated into a CFA set-up, but are known to yield poor dust size records. The dilemma between high quality sizing and high depth resolution was found...

  4. High resolving power spectrometer for beam analysis

    International Nuclear Information System (INIS)

    Moshammer, H.W.; Spencer, J.E.

    1992-03-01

    We describe a system designed to analyze the high energy, closely spaced bunches from individual RF pulses. Neither a large solid angle nor momentum range is required so this allows characteristics that appear useful for other applications such as ion beam lithography. The spectrometer is a compact, double-focusing QBQ design whose symmetry allows the Quads to range between F or D with a correspondingly large range of magnifications, dispersion and resolving power. This flexibility insures the possibility of spatially separating all of the bunches along the focal plane with minimal transverse kicks and bending angle for differing input conditions. The symmetry of the system allows a simple geometric interpretationof the resolving power in terms of thin lenses and ray optics. We discuss the optics and the hardware that is proposed to measure emittance, energy, energy spread and bunch length for each bunch in an RF pulse train for small bunch separations. We also discuss how to use such measurements for feedback and feedforward control of these bunch characteristics as well as maintain their stability. 2 refs

  5. Highly Resolved Studies of Vacuum Ultraviolet Photoionization Dynamics

    Science.gov (United States)

    Kakar, Sandeep

    We use measurements of dispersed fluorescence from electronically excited photoions to study fundamental aspects of intramolecular dynamics. Our experimental innovations make it possible to obtain highly resolved photoionization data that offer qualitative insights into molecular scattering. In particular, we obtain vibrationally resolved data to probe coupling between the electronic and nuclear degrees of freedom by studying the distribution of vibrational energy among photoions. Vibrationally resolved branching ratios are measured over a broad spectral range of excitation energy and their non-Franck-Condon behavior is used as a tool to investigate two diverse aspects of shape resonant photoionization. First, vibrational branching ratios are obtained for the SiF_4 5a _1^{-1} and CS_2 5sigma_{rm u} ^{-1} photoionization channels to help elucidate the microscopic aspects of shape resonant wavefunction for polyatomic molecules. It is shown that in such molecules the shape resonant wavefunction is not necessarily attributable to a specific bond in the molecule. Second, the multichannel aspect of shape resonant photoionization dynamics, reflected in continuum channel coupling, is investigated by obtaining vibrational branching ratios for the 2 sigma_{rm u}^{ -1} and 4sigma^{ -1} photoionization of the isoelectronic molecules N_2 and CO, respectively. These data indicate that effects of continuum coupling may be widespread. We also present the first set of rotationally resolved data over a wide energy range for the 2 sigma_{rm u}^{ -1} photoionization of N_2. These data probe the partitioning of the angular momentum between the photoelectron and photoion, and highlight the multicenter nature of the molecular potential. These case studies illustrate the utility of dispersed fluorescence measurements as a complement to photoelectron spectroscopy for obtaining highly resolved data for molecular photoionization. These measurements makes it possible to probe intrinsically

  6. Alignment of time-resolved data from high throughput experiments.

    Science.gov (United States)

    Abidi, Nada; Franke, Raimo; Findeisen, Peter; Klawonn, Frank

    2016-12-01

    To better understand the dynamics of the underlying processes in cells, it is necessary to take measurements over a time course. Modern high-throughput technologies are often used for this purpose to measure the behavior of cell products like metabolites, peptides, proteins, [Formula: see text]RNA or mRNA at different points in time. Compared to classical time series, the number of time points is usually very limited and the measurements are taken at irregular time intervals. The main reasons for this are the costs of the experiments and the fact that the dynamic behavior usually shows a strong reaction and fast changes shortly after a stimulus and then slowly converges to a certain stable state. Another reason might simply be missing values. It is common to repeat the experiments and to have replicates in order to carry out a more reliable analysis. The ideal assumptions that the initial stimulus really started exactly at the same time for all replicates and that the replicates are perfectly synchronized are seldom satisfied. Therefore, there is a need to first adjust or align the time-resolved data before further analysis is carried out. Dynamic time warping (DTW) is considered as one of the common alignment techniques for time series data with equidistant time points. In this paper, we modified the DTW algorithm so that it can align sequences with measurements at different, non-equidistant time points with large gaps in between. This type of data is usually known as time-resolved data characterized by irregular time intervals between measurements as well as non-identical time points for different replicates. This new algorithm can be easily used to align time-resolved data from high-throughput experiments and to come across existing problems such as time scarcity and existing noise in the measurements. We propose a modified method of DTW to adapt requirements imposed by time-resolved data by use of monotone cubic interpolation splines. Our presented approach

  7. Highly-resolving Rutherford-scattering spectroscopy with heavy ions

    International Nuclear Information System (INIS)

    Klein, C.

    2003-10-01

    in the present thesis for the first time the Browne-Buechner spectrometer for the highly resolving ion-beam analysis in the ion beam center Rossendorf is completely presented. A main topic of this theis lied in the apparative construction and the taking-into-operation of the spectrometer and the scattering chamber including the facilities for the sample treatment and characterization. In the framework of this thesis for the chosen measurement arrangement the experimental conditions were elaborated, which allow the routine-like application of the spectrometer for analyses of thin-film systems. for C and Li ions as incident particles especially the straggling was more precisely determined in a large range of materials. By means of the spectrometer also the interaction of the ion with the solid respectively single atoms on its surface could be studied. For the first time the mean charge-state after the single collision on a gold atom was determined for differently heavy ions in a wide energy range

  8. Size resolved airborne particulate polysaccharides in summer high Arctic

    Science.gov (United States)

    Leck, C.; Gao, Q.; Mashayekhy Rad, F.; Nilsson, U.

    2013-04-01

    Size-resolved aerosol samples for subsequent determination of polysaccharides (monosaccharides in combined form) were collected in air over the central Arctic Ocean during the biologically most active period between the late summer melt season and into the transition to autumn freeze-up. The analysis was carried out using liquid chromatography coupled with highly selective and sensitive tandem mass spectrometry. Polysaccharides were detected in all sizes ranging from 0.035 to 10 μm in diameter with distinct features of heteropolysaccharides, enriched in xylose, glucose + mannose as well as a substantial fraction of deoxysugars. Polysaccharides containing deoxysugars showed a bimodal structure with about 60% of their mass found in the Aitken mode over the pack ice area. Pentose (xylose) and hexose (glucose + mannose) showed a weaker bimodal character and were largely found in the coarse mode in addition to a minor fraction apportioned in the sub-micrometer size range. The concentration of total hydrolysable neutral sugars (THNS) in the samples collected varied over 3 orders of magnitude (1 to 692 pmol m-3) in the super-micrometer size fraction and to a lesser extent in sub-micrometer particles (4 to 88 pmol m-3). Lowest THNS concentrations were observed in air masses that had spent more than 5 days over the pack ice. Within the pack ice area, about 53% (by mass) of the total mass of polysaccharides were found in sub-micrometer particles. The relative abundance of sub-micrometer polysaccharides was closely related to the length of time that the air mass spent over pack ice, with highest fraction (> 90%) observed for > 7 days of advection. The ambient aerosol particles collected onboard ship showed similar monosaccharide composition, compared to particles generated experimentally in situ at the open lead site. This supports the existence of a primary source of particulate polysaccharides from open leads by bubble bursting at the air-sea interface. We speculate that

  9. Multiscale correlations in highly resolved Large Eddy Simulations

    Science.gov (United States)

    Biferale, Luca; Buzzicotti, Michele; Linkmann, Moritz

    2017-11-01

    Understanding multiscale turbulent statistics is one of the key challenges for many modern applied and fundamental problems in fluid dynamics. One of the main obstacles is the existence of anomalously strong non Gaussian fluctuations, which become more and more important with increasing Reynolds number. In order to assess the performance of LES models in reproducing these extreme events with reasonable accuracy, it is helpful to further understand the statistical properties of the coupling between the resolved and the subgrid scales. We present analytical and numerical results focussing on the multiscale correlations between the subgrid stress and the resolved velocity field obtained both from LES and filtered DNS data. Furthermore, a comparison is carried out between LES and DNS results concerning the scaling behaviour of higher-order structure functions using both Smagorinsky or self-similar Fourier sub-grid models. ERC AdG Grant No 339032 NewTURB.

  10. Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells

    Science.gov (United States)

    2016-07-01

    HIGHLY RESOLVED SUB-TERAHERTZ VIBRATIONAL SPECTROSCOPY OF BIOLOGICAL MACROMOLECULES AND BACTERIA CELLS ECBC...SUBTITLE Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells 5a. CONTRACT NUMBER W911SR-14-P...22 4.3 Bacteria THz Study

  11. Depth-resolved incoherent and coherent wide-field high-content imaging (Conference Presentation)

    Science.gov (United States)

    So, Peter T.

    2016-03-01

    Recent advances in depth-resolved wide-field imaging technique has enabled many high throughput applications in biology and medicine. Depth resolved imaging of incoherent signals can be readily accomplished with structured light illumination or nonlinear temporal focusing. The integration of these high throughput systems with novel spectroscopic resolving elements further enable high-content information extraction. We will introduce a novel near common-path interferometer and demonstrate its uses in toxicology and cancer biology applications. The extension of incoherent depth-resolved wide-field imaging to coherent modality is non-trivial. Here, we will cover recent advances in wide-field 3D resolved mapping of refractive index, absorbance, and vibronic components in biological specimens.

  12. Can positron 2D-ACAR resolve the electronic structure of high-Tc superconductors

    International Nuclear Information System (INIS)

    Chan, L.P.; Lynn, K.G.; Harshman, D.R.

    1992-01-01

    In this paper, the authors examine the ability of the positron Two-Dimensional Angular Correlation Annihilation Radiation (2D-ACAR) technique to resolve the electronic structures of high-T c cuprate superconductors. Following a short description of the technique, discussions of the theoretical assumptions, data analysis and experimental considerations, in relation to the high-T c superconductors, are given. The authors briefly review recent 2D-ACAR experiments on YBa 2 Cu 3 O 7-x , Bi 2 Sr 2 CaCuO 8+δ and La 2-x Sr x CuO 4 . The 2D-ACAR technique is useful in resolving the band crossings associated with the layers of the superconductors that are preferentially sampled by the positrons. Together with other Fermi surface measurements (namely angle-resolved photoemission), 2D-ACAR can resolve some of the electronic structures of high-T c cuprate superconductors

  13. Arbitrarily high super-resolving phase measurements at telecommunication wavelengths

    International Nuclear Information System (INIS)

    Kothe, Christian; Bjoerk, Gunnar; Bourennane, Mohamed

    2010-01-01

    We present two experiments that achieve phase super-resolution at telecommunication wavelengths. One of the experiments is realized in the space domain and the other is realized in the time domain. Both experiments show high visibility and are performed with standard lasers and single-photon detectors. The first experiment uses six-photon coincidences, whereas the latter experiment needs no coincidence measurements, is easy to perform, and achieves, in principle, arbitrarily high phase super-resolution. Here, we demonstrate a 30-fold increase of the resolution. We stress that neither entanglement nor joint detection is needed in these experiments, which demonstrates that neither is necessary to achieve phase super-resolution.

  14. Polarization-Resolved Study of High Harmonics from Bulk Semiconductors

    Science.gov (United States)

    Kaneshima, Keisuke; Shinohara, Yasushi; Takeuchi, Kengo; Ishii, Nobuhisa; Imasaka, Kotaro; Kaji, Tomohiro; Ashihara, Satoshi; Ishikawa, Kenichi L.; Itatani, Jiro

    2018-06-01

    The polarization property of high harmonics from gallium selenide is investigated using linearly polarized midinfrared laser pulses. With a high electric field, the perpendicular polarization component of the odd harmonics emerges, which is not present with a low electric field and cannot be explained by the perturbative nonlinear optics. A two-dimensional single-band model is developed to show that the anisotropic curvature of an energy band of solids, which is pronounced in an outer part of the Brillouin zone, induces the generation of the perpendicular odd harmonics. This model is validated by three-dimensional quantum mechanical simulations, which reproduce the orientation dependence of the odd-order harmonics. The quantum mechanical simulations also reveal that the odd- and even-order harmonics are produced predominantly by the intraband current and interband polarization, respectively. These experimental and theoretical demonstrations clearly show a strong link between the band structure of a solid and the polarization property of the odd-order harmonics.

  15. Time resolved Thomson scattering measurements on a high pressure mercury lamp

    NARCIS (Netherlands)

    Vries, de N.; Zhu, Xiao-Yan; Kieft, E.R.; Mullen, van der J.J.A.M.

    2005-01-01

    Time resolved Thomson scattering (TS) measurements have been performed on an ac driven high pressure mercury lamp. For this high intensity discharge (HID) lamp, TS is coherent and a coherent fitting routine, including rotational Raman calibration, was used to determine ne and Te from the measured

  16. Advances in high-order harmonic generation sources for time-resolved investigations

    Energy Technology Data Exchange (ETDEWEB)

    Reduzzi, Maurizio [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Carpeggiani, Paolo [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Kühn, Sergei [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Calegari, Francesca [Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Nisoli, Mauro; Stagira, Salvatore [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Vozzi, Caterina [Institute of Photonics and Nanotechnologies, CNR-IFN, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Dombi, Peter [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Wigner Research Center for Physics, 1121 Budapest (Hungary); Kahaly, Subhendu [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Tzallas, Paris; Charalambidis, Dimitris [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Foundation for Research and Technology – Hellas, Institute of Electronic Structure and Lasers, P.O. Box 1527, GR-711 10 Heraklion, Crete (Greece); Varju, Katalin [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); Department of Optics and Quantum Electronics, University of Szeged, Dóm tér 9, 6720 Szeged (Hungary); Osvay, Karoly [ELI-ALPS, ELI-Hu Kft., Dugonics ter 13, H-6720 Szeged (Hungary); and others

    2015-10-15

    We review the main research directions ongoing in the development of extreme ultraviolet sources based on high-harmonic generation for the synthesization and application of trains and isolated attosecond pulses to time-resolved spectroscopy. A few experimental and theoretical works will be discussed in connection to well-established attosecond techniques. In this context, we present the unique possibilities offered for time-resolved investigations on the attosecond timescale by the new Extreme Light Infrastructure Attosecond Light Pulse Source, which is currently under construction.

  17. Advances in high-order harmonic generation sources for time-resolved investigations

    International Nuclear Information System (INIS)

    Reduzzi, Maurizio; Carpeggiani, Paolo; Kühn, Sergei; Calegari, Francesca; Nisoli, Mauro; Stagira, Salvatore; Vozzi, Caterina; Dombi, Peter; Kahaly, Subhendu; Tzallas, Paris; Charalambidis, Dimitris; Varju, Katalin; Osvay, Karoly

    2015-01-01

    We review the main research directions ongoing in the development of extreme ultraviolet sources based on high-harmonic generation for the synthesization and application of trains and isolated attosecond pulses to time-resolved spectroscopy. A few experimental and theoretical works will be discussed in connection to well-established attosecond techniques. In this context, we present the unique possibilities offered for time-resolved investigations on the attosecond timescale by the new Extreme Light Infrastructure Attosecond Light Pulse Source, which is currently under construction.

  18. Radially resolved simulation of a high-gain free electron laser amplifier

    International Nuclear Information System (INIS)

    Fawley, W.M.; Prosnitz, D.; Doss, S.; Gelinas, R.

    1983-01-01

    The results of a two-dimensional simulation of a high-gain free electron laser (FEL) amplifier is presented. The simulation solves the inhomogeneous paraxial wave equation. The source term is radially resolved and is obtained by tracking the interaction of the laser field with localized macroparticles

  19. Developments in time-resolved high pressure x-ray diffraction using rapid compression and decompression

    International Nuclear Information System (INIS)

    Smith, Jesse S.; Sinogeikin, Stanislav V.; Lin, Chuanlong; Rod, Eric; Bai, Ligang; Shen, Guoyin

    2015-01-01

    Complementary advances in high pressure research apparatus and techniques make it possible to carry out time-resolved high pressure research using what would customarily be considered static high pressure apparatus. This work specifically explores time-resolved high pressure x-ray diffraction with rapid compression and/or decompression of a sample in a diamond anvil cell. Key aspects of the synchrotron beamline and ancillary equipment are presented, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell

  20. A framework for widespread replication of a highly spatially resolved childhood lead exposure risk model.

    Science.gov (United States)

    Kim, Dohyeong; Galeano, M Alicia Overstreet; Hull, Andrew; Miranda, Marie Lynn

    2008-12-01

    Preventive approaches to childhood lead poisoning are critical for addressing this longstanding environmental health concern. Moreover, increasing evidence of cognitive effects of blood lead levels system-based childhood lead exposure risk models, especially if executed at highly resolved spatial scales, can help identify children most at risk of lead exposure, as well as prioritize and direct housing and health-protective intervention programs. However, developing highly resolved spatial data requires labor-and time-intensive geocoding and analytical processes. In this study we evaluated the benefit of increased effort spent geocoding in terms of improved performance of lead exposure risk models. We constructed three childhood lead exposure risk models based on established methods but using different levels of geocoded data from blood lead surveillance, county tax assessors, and the 2000 U.S. Census for 18 counties in North Carolina. We used the results to predict lead exposure risk levels mapped at the individual tax parcel unit. The models performed well enough to identify high-risk areas for targeted intervention, even with a relatively low level of effort on geocoding. This study demonstrates the feasibility of widespread replication of highly spatially resolved childhood lead exposure risk models. The models guide resource-constrained local health and housing departments and community-based organizations on how best to expend their efforts in preventing and mitigating lead exposure risk in their communities.

  1. Time-resolved High Spectral Resolution Observation of 2MASSW J0746425+200032AB

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji; Mawet, Dimitri [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 E. California Boulevard, Pasadena, CA 91106 (United States); Prato, Lisa, E-mail: ji.wang@caltech.edu [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

    2017-03-20

    Many brown dwarfs (BDs) exhibit photometric variability at levels from tenths to tens of percents. The photometric variability is related to magnetic activity or patchy cloud coverage, characteristic of BDs near the L–T transition. Time-resolved spectral monitoring of BDs provides diagnostics of cloud distribution and condensate properties. However, current time-resolved spectral studies of BDs are limited to low spectral resolution ( R ∼ 100) with the exception of the study of Luhman 16 AB at a resolution of 100,000 using the VLT+CRIRES. This work yielded the first map of BD surface inhomogeneity, highlighting the importance and unique contribution of high spectral resolution observations. Here, we report on the time-resolved high spectral resolution observations of a nearby BD binary, 2MASSW J0746425+200032AB. We find no coherent spectral variability that is modulated with rotation. Based on simulations, we conclude that the coverage of a single spot on 2MASSW J0746425+200032AB is smaller than 1% or 6.25% if spot contrast is 50% or 80% of its surrounding flux, respectively. Future high spectral resolution observations aided by adaptive optics systems can put tighter constraints on the spectral variability of 2MASSW J0746425+200032AB and other nearby BDs.

  2. Angle resolved mass spectrometry of positive ions transmitted through high aspect ratio channels in a radio frequency discharge

    NARCIS (Netherlands)

    Stoffels - Adamowicz, E.; Stoffels, W.W.; Tachibana, K.; Imai, S.

    1997-01-01

    The behavior of positive ions in high aspect ratio structures, relevant to the reactive ion etching of deep trenches, has been studied by means of energy resolved mass spectrometry. High aspect ratio trenches are simulated by capillary plates with various aspect ratios. Angle resolved measurements

  3. Multi-Channel Amplifier-Discriminator for Highly Time-Resolved Detection

    CERN Document Server

    Despeisse, M; Lapington, J; Jarron, P

    2011-01-01

    A low-power multi-channel amplifier-discriminator was developed for application in highly time-resolved detection systems. The proposed circuit architecture, so-called Nino, is based on a time-over-threshold approach and shows a high potential for time-resolved readout of solid-state photo-detectors and of detectors based on vacuum technologies. The Irpics circuit was designed in a 250 nm CMOS technology, implementing 32 channels of a Nino version optimized to achieve high-time resolution on the output low-voltage differential signals (LVDS) while keeping a low power consumption of 10 mW per channel. Electrical characterizations of the circuit demonstrate a very low intrinsic time jitter on the output pulse leading edge, measured below 10 ps rms for each channel for high input signal charges (100 fC) and below 25 ps rms for low input signal charges (20-100 fC). The read-out architecture moreover permits to retrieve the input signal charge from the timing measurements, while a calibration procedure was develop...

  4. Angle-resolved photoemission in high Tc cuprates from theoretical viewpoints

    International Nuclear Information System (INIS)

    Tohyama, T.; Maekawa, S.

    2000-01-01

    The angle-resolved photoemission (ARPES) technique has been developed rapidly over the last decade, accompanied by the improvement of energy and momentum resolutions. This technique has been established as the most powerful tool to investigate the high T c cuprate superconductors. We review recent ARPES data on the cuprates from a theoretical point of view, with emphasis on the systematic evolution of the spectral weight near the momentum (π, 0) from insulator to overdoped systems. The effects of charge stripes on the ARPES spectra are also reviewed. Some recent experimental and theoretical efforts to understand the superconducting state and the pseudogap phenomenon are discussed. (author)

  5. A time resolving data acquisition system for multiple high-resolution position sensitive detectors

    International Nuclear Information System (INIS)

    Dimmler, D.G.

    1988-01-01

    An advanced time resolving data collection system for use in neutron and x-ray spectrometry has been implemented and put into routine operation. The system collects data from high-resolution position-sensitive area detectors with a maximum cumulative rate of 10/sup 6/ events per second. The events are sorted, in real-time, into many time-slice arrays. A programmable timing control unit allows for a wide choice of time sequences and time-slice array sizes. The shortest dwell time on a slice may be below 1 ms and the delay to switch between slices is zero

  6. Quantum state engineering, purification, and number-resolved photon detection with high-finesse optical cavities

    DEFF Research Database (Denmark)

    Nielsen, Anne E. B.; Muschik, Christine A.; Giedke, Geza

    2010-01-01

    We propose and analyze a multifunctional setup consisting of high-finesse optical cavities, beam splitters, and phase shifters. The basic scheme projects arbitrary photonic two-mode input states onto the subspace spanned by the product of Fock states |n>|n> with n=0,1,2,.... This protocol does no...... is especially attractive as a generalization to many modes allows for distribution and purification of entanglement in networks. In an alternative working mode, the setup allows for quantum nondemolition number resolved photodetection in the optical domain....

  7. Time-resolved x-ray spectra of laser irradiated high-Z targets

    International Nuclear Information System (INIS)

    Lee, P.H.Y.; Attwood, D.T.; Boyle, M.J.; Campbell, E.M.; Coleman, L.C.; Kornblum, H.N.

    1977-01-01

    Recent results obtained by using the Livermore 15 psec x-ray streak camera to record x-ray emission from laser-irradiated high-z targets in the 1-20 keV range are reported. Nine to eleven K-edge filter channels were used for the measurements. In the lower energy channels, a dynamic range of x-ray emission intensity of better than three orders of magnitude have been recorded. Data will be presented which describe temporally and spectrally resolved x-ray spectra of gold disk targets irradiated by laser pulses from the Argus facility, including the temporal evolution of the superthermal x-ray tail

  8. High temperature corrosion under conditions simulating biomass firing: depth-resolved phase identification

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2014-01-01

    ) were coated with KCl and is o-thermally exposed at 560 o C for 168 h under a flue gas corresponding to straw firing. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) characterization techniques were employed for comprehensive characterization......Both cross-sectional and plan view, ‘top-down’ characterization methods were employed , for a depth-resolved characterization of corrosion products resulting from high temperature corrosion under laboratory conditions simulating biomass firing. Samples of an austenitic stainless steel (TP 347H FG...... of the corrosion product. Results from this comprehensive characterization revealed more details on the morphology and composition of the corrosion product....

  9. A Virtual Study of Grid Resolution on Experiments of a Highly-Resolved Turbulent Plume

    Science.gov (United States)

    Maisto, Pietro M. F.; Marshall, Andre W.; Gollner, Michael J.; Fire Protection Engineering Department Collaboration

    2017-11-01

    An accurate representation of sub-grid scale turbulent mixing is critical for modeling fire plumes and smoke transport. In this study, PLIF and PIV diagnostics are used with the saltwater modeling technique to provide highly-resolved instantaneous field measurements in unconfined turbulent plumes useful for statistical analysis, physical insight, and model validation. The effect of resolution was investigated employing a virtual interrogation window (of varying size) applied to the high-resolution field measurements. Motivated by LES low-pass filtering concepts, the high-resolution experimental data in this study can be analyzed within the interrogation windows (i.e. statistics at the sub-grid scale) and on interrogation windows (i.e. statistics at the resolved scale). A dimensionless resolution threshold (L/D*) criterion was determined to achieve converged statistics on the filtered measurements. Such a criterion was then used to establish the relative importance between large and small-scale turbulence phenomena while investigating specific scales for the turbulent flow. First order data sets start to collapse at a resolution of 0.3D*, while for second and higher order statistical moments the interrogation window size drops down to 0.2D*.

  10. Time-resolved energy spectrum of a pseudospark-produced high-brightness electron beam

    International Nuclear Information System (INIS)

    Myers, T.J.; Ding, B.N.; Rhee, M.J.

    1992-01-01

    The pseudospark, a fast low-pressure gas discharge between a hollow cathode and a planar anode, is found to be an interesting high-brightness electron beam source. Typically, all electron beam produced in the pseudospark has the peak current of ∼1 kA, pulse duration of ∼50 ns, and effective emittance of ∼100 mm-mrad. The energy information of this electron beam, however, is least understood due to the difficulty of measuring a high-current-density beam that is partially space-charge neutralized by the background ions produced in the gas. In this paper, an experimental study of the time-resolved energy spectrum is presented. The pseudospark produced electron beam is injected into a vacuum through a small pinhole so that the electrons without background ions follow single particle motion; the beam is sent through a negative biased electrode and the only portion of beam whose energy is greater than the bias voltage can pass through the electrode and the current is measured by a Faraday cup. The Faraday cup signals with various bias voltage are recorded in a digital oscilloscope. The recorded waveforms are then numerically analyzed to construct a time-resolved energy spectrum. Preliminary results are presented

  11. Angle-resolved reflection spectroscopy of high-quality PMMA opal crystal

    Science.gov (United States)

    Nemtsev, Ivan V.; Tambasov, Igor A.; Ivanenko, Alexander A.; Zyryanov, Victor Ya.

    2018-02-01

    PMMA opal crystal was prepared by a simple hybrid method, which includes sedimentation, meniscus formation and evaporation. We investigated three surfaces of this crystal by angle-resolved reflective light spectroscopy and SEM study. The angle-resolved reflective measurements were carried out in the 400-1100 nm range. We have determined the high-quality ordered surface of the crystal region. Narrow particle size distribution of the surface has been revealed. The average particle diameter obtained with SEM was nearly 361 nm. The most interesting result was that reflectivity of the surface turned out up to 98% at normal light incidence. Using a fit of dependences of the maximum reflectivity wavelength from an angle based on the Bragg-Snell law, the wavelength of maximum 0° reflectivity, the particle diameter and the fill factor have been determined. For the best surface maximum reflectivity wavelength of a 0° angle was estimated to be 869 nm. The particle diameter and fill factor were calculated as 372 nm and 0.8715, respectively. The diameter obtained by fitting is in excellent agreement with the particle diameter obtained with SEM. The reflectivity maximum is assumed to increase significantly when increasing the fill factor. We believe that using our simple approach to manufacture PMMA opal crystals will significantly increase the fabrication of high-quality photonic crystal templates and thin films.

  12. An integrated approach using high time-resolved tools to study the origin of aerosols

    International Nuclear Information System (INIS)

    Di Gilio, A.; Gennaro, G. de; Dambruoso, P.; Ventrella, G.

    2015-01-01

    Long-range transport of natural and/or anthropogenic particles can contribute significantly to PM10 and PM2.5 concentrations and some European cities often fail to comply with PM daily limit values due to the additional impact of particles from remote sources. For this reason, reliable methodologies to identify long-range transport (LRT) events would be useful to better understand air pollution phenomena and support proper decision-making. This study explores the potential of an integrated and high time-resolved monitoring approach for the identification and characterization of local, regional and long-range transport events of high PM. In particular, the goal of this work was also the identification of time-limited event. For this purpose, a high time-resolved monitoring campaign was carried out at an urban background site in Bari (southern Italy) for about 20 days (1st–20th October 2011). The integration of collected data as the hourly measurements of inorganic ions in PM 2.5 and their gas precursors and of the natural radioactivity, in addition to the analyses of aerosol maps and hourly back trajectories (BT), provided useful information for the identification and chemical characterization of local sources and trans-boundary intrusions. Non-sea salt (nss) sulfate levels were found to increase when air masses came from northeastern Europe and higher dispersive conditions of the atmosphere were detected. Instead, higher nitrate and lower nss-sulfate concentrations were registered in correspondence with air mass stagnation and attributed to local traffic source. In some cases, combinations of local and trans-boundary sources were observed. Finally, statistical investigations such as the principal component analysis (PCA) applied on hourly ion concentrations and the cluster analyses, the Potential Source Contribution Function (PSCF) and the Concentration Weighted Trajectory (CWT) models computed on hourly back-trajectories enabled to complete a cognitive framework

  13. An integrated approach using high time-resolved tools to study the origin of aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Di Gilio, A. [Chemistry Department, University of Bari, via Orabona, 4, 70126 Bari (Italy); ARPA PUGLIA, Corso Trieste, 27, 70126 Bari (Italy); Gennaro, G. de, E-mail: gianluigi.degennaro@uniba.it [Chemistry Department, University of Bari, via Orabona, 4, 70126 Bari (Italy); ARPA PUGLIA, Corso Trieste, 27, 70126 Bari (Italy); Dambruoso, P. [Chemistry Department, University of Bari, via Orabona, 4, 70126 Bari (Italy); ARPA PUGLIA, Corso Trieste, 27, 70126 Bari (Italy); Ventrella, G. [Chemistry Department, University of Bari, via Orabona, 4, 70126 Bari (Italy)

    2015-10-15

    Long-range transport of natural and/or anthropogenic particles can contribute significantly to PM10 and PM2.5 concentrations and some European cities often fail to comply with PM daily limit values due to the additional impact of particles from remote sources. For this reason, reliable methodologies to identify long-range transport (LRT) events would be useful to better understand air pollution phenomena and support proper decision-making. This study explores the potential of an integrated and high time-resolved monitoring approach for the identification and characterization of local, regional and long-range transport events of high PM. In particular, the goal of this work was also the identification of time-limited event. For this purpose, a high time-resolved monitoring campaign was carried out at an urban background site in Bari (southern Italy) for about 20 days (1st–20th October 2011). The integration of collected data as the hourly measurements of inorganic ions in PM{sub 2.5} and their gas precursors and of the natural radioactivity, in addition to the analyses of aerosol maps and hourly back trajectories (BT), provided useful information for the identification and chemical characterization of local sources and trans-boundary intrusions. Non-sea salt (nss) sulfate levels were found to increase when air masses came from northeastern Europe and higher dispersive conditions of the atmosphere were detected. Instead, higher nitrate and lower nss-sulfate concentrations were registered in correspondence with air mass stagnation and attributed to local traffic source. In some cases, combinations of local and trans-boundary sources were observed. Finally, statistical investigations such as the principal component analysis (PCA) applied on hourly ion concentrations and the cluster analyses, the Potential Source Contribution Function (PSCF) and the Concentration Weighted Trajectory (CWT) models computed on hourly back-trajectories enabled to complete a cognitive

  14. Time-resolved diffusion tomographic 2D and 3D imaging in highly scattering turbid media

    Science.gov (United States)

    Alfano, Robert R. (Inventor); Cai, Wei (Inventor); Gayen, Swapan K. (Inventor)

    2000-01-01

    A method for imaging objects in highly scattering turbid media. According to one embodiment of the invention, the method involves using a plurality of intersecting source/detectors sets and time-resolving equipment to generate a plurality of time-resolved intensity curves for the diffusive component of light emergent from the medium. For each of the curves, the intensities at a plurality of times are then inputted into the following inverse reconstruction algorithm to form an image of the medium: wherein W is a matrix relating output at source and detector positions r.sub.s and r.sub.d, at time t, to position r, .LAMBDA. is a regularization matrix, chosen for convenience to be diagonal, but selected in a way related to the ratio of the noise, to fluctuations in the absorption (or diffusion) X.sub.j that we are trying to determine: .LAMBDA..sub.ij =.lambda..sub.j .delta..sub.ij with .lambda..sub.j =/ Y is the data collected at the detectors, and X.sup.k is the kth iterate toward the desired absorption information. An algorithm, which combines a two dimensional (2D) matrix inversion with a one-dimensional (1D) Fourier transform inversion is used to obtain images of three dimensional hidden objects in turbid scattering media.

  15. Time-resolved diffusion tomographic imaging in highly scattering turbid media

    Science.gov (United States)

    Alfano, Robert R. (Inventor); Cai, Wei (Inventor); Liu, Feng (Inventor); Lax, Melvin (Inventor); Das, Bidyut B. (Inventor)

    1998-01-01

    A method for imaging objects in highly scattering turbid media. According to one embodiment of the invention, the method involves using a plurality of intersecting source/detectors sets and time-resolving equipment to generate a plurality of time-resolved intensity curves for the diffusive component of light emergent from the medium. For each of the curves, the intensities at a plurality of times are then inputted into the following inverse reconstruction algorithm to form an image of the medium: X.sup.(k+1).spsp.T =?Y.sup.T W+X.sup.(k).spsp.T .LAMBDA.!?W.sup.T W+.LAMBDA.!.sup.-1 wherein W is a matrix relating output at detector position r.sub.d, at time t, to source at position r.sub.s, .LAMBDA. is a regularization matrix, chosen for convenience to be diagonal, but selected in a way related to the ratio of the noise, to fluctuations in the absorption (or diffusion) X.sub.j that we are trying to determine: .LAMBDA..sub.ij =.lambda..sub.j .delta..sub.ij with .lambda..sub.j =/ Here Y is the data collected at the detectors, and X.sup.k is the kth iterate toward the desired absoption information.

  16. Evaluation of a High Resolving Power Time-of-Flight Mass Spectrometer for Drug Analysis in Terms of Resolving Power and Acquisition Rate

    Science.gov (United States)

    Pelander, Anna; Decker, Petra; Baessmann, Carsten; Ojanperä, Ilkka

    2011-02-01

    Liquid chromatography time-of-flight mass spectrometry (LC-TOFMS) is applied increasingly to various fields of small molecule analysis. The moderate resolving power (RP) of standard TOFMS instruments poses a risk of false negative results when complex biological matrices are to be analyzed. In this study, the performance of a high resolving power TOFMS instrument (maXis by Bruker Daltonik, Bremen, Germany) was evaluated for drug analysis. By flow injection analysis of critical drug mixtures, including a total of 17 compounds with nominal masses of 212-415 Da and with mass differences of 8.8-23.5 mDa, RP varied from 34,400 to 51,900 (FWHM). The effect of acquisition rate on RP, mass accuracy, and isotopic pattern fit was studied by applying 1, 2, 5, 10, and 20 Hz acquisition rates in a 16 min gradient elution LC separation. All three variables were independent of the acquisition rate, with an average mass accuracy and isotopic pattern fit factor (mSigma) of 0.33 ppm and 5.9, respectively. The average relative standard deviation of RP was 1.8%, showing high repeatability. The performance was tested further with authentic urine extracts containing a co-eluting compound pair with a nominal mass of 296 Da and an 11.2 mDa mass difference. The authentic sample components were readily resolved and correctly identified by the automated data analysis. The average RP, mass accuracy, and isotopic pattern fit were 36,600, 0.9 ppm, and 7.3 mSigma, respectively.

  17. High Resolution Angle Resolved Photoemission Studies on Quasi-Particle Dynamics in Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Leem, C.S.

    2010-06-02

    We obtained the spectral function of the graphite H point using high resolution angle resolved photoelectron spectroscopy (ARPES). The extracted width of the spectral function (inverse of the photo-hole lifetime) near the H point is approximately proportional to the energy as expected from the linearly increasing density of states (DOS) near the Fermi energy. This is well accounted by our electron-phonon coupling theory considering the peculiar electronic DOS near the Fermi level. And we also investigated the temperature dependence of the peak widths both experimentally and theoretically. The upper bound for the electron-phonon coupling parameter is 0.23, nearly the same value as previously reported at the K point. Our analysis of temperature dependent ARPES data at K shows that the energy of phonon mode of graphite has much higher energy scale than 125K which is dominant in electron-phonon coupling.

  18. High-intensity power-resolved radiation imaging of an operational nuclear reactor.

    Science.gov (United States)

    Beaumont, Jonathan S; Mellor, Matthew P; Villa, Mario; Joyce, Malcolm J

    2015-10-09

    Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed to image radiation fields emitted during the operation of a TRIGA test reactor allowing a spatial visualization of the internal reactor conditions to be obtained. The imaged flux in each case is found to scale linearly with reactor power indicating that this method may be used for power-resolved reactor monitoring and for the assay of ongoing nuclear criticalities in damaged nuclear reactors.

  19. Resolving molecular vibronic structure using high-sensitivity two-dimensional electronic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bizimana, Laurie A.; Brazard, Johanna; Carbery, William P.; Gellen, Tobias; Turner, Daniel B., E-mail: dturner@nyu.edu [Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003 (United States)

    2015-10-28

    Coherent multidimensional optical spectroscopy is an emerging technique for resolving structure and ultrafast dynamics of molecules, proteins, semiconductors, and other materials. A current challenge is the quality of kinetics that are examined as a function of waiting time. Inspired by noise-suppression methods of transient absorption, here we incorporate shot-by-shot acquisitions and balanced detection into coherent multidimensional optical spectroscopy. We demonstrate that implementing noise-suppression methods in two-dimensional electronic spectroscopy not only improves the quality of features in individual spectra but also increases the sensitivity to ultrafast time-dependent changes in the spectral features. Measurements on cresyl violet perchlorate are consistent with the vibronic pattern predicted by theoretical models of a highly displaced harmonic oscillator. The noise-suppression methods should benefit research into coherent electronic dynamics, and they can be adapted to multidimensional spectroscopies across the infrared and ultraviolet frequency ranges.

  20. Noise-free high-efficiency photon-number-resolving detectors

    International Nuclear Information System (INIS)

    Rosenberg, Danna; Lita, Adriana E.; Miller, Aaron J.; Nam, Sae Woo

    2005-01-01

    High-efficiency optical detectors that can determine the number of photons in a pulse of monochromatic light have applications in a variety of physics studies, including post-selection-based entanglement protocols for linear optics quantum computing and experiments that simultaneously close the detection and communication loopholes of Bell's inequalities. Here we report on our demonstration of fiber-coupled, noise-free, photon-number-resolving transition-edge sensors with 88% efficiency at 1550 nm. The efficiency of these sensors could be made even higher at any wavelength in the visible and near-infrared spectrum without resulting in a higher dark-count rate or degraded photon-number resolution

  1. A tunable low-energy photon source for high-resolution angle-resolved photoemission spectroscopy

    International Nuclear Information System (INIS)

    Harter, John W.; Monkman, Eric J.; Shai, Daniel E.; Nie Yuefeng; Uchida, Masaki; Burganov, Bulat; Chatterjee, Shouvik; King, Philip D. C.; Shen, Kyle M.

    2012-01-01

    We describe a tunable low-energy photon source consisting of a laser-driven xenon plasma lamp coupled to a Czerny-Turner monochromator. The combined tunability, brightness, and narrow spectral bandwidth make this light source useful in laboratory-based high-resolution photoemission spectroscopy experiments. The source supplies photons with energies up to ∼7 eV, delivering under typical conditions >10 12 ph/s within a 10 meV spectral bandwidth, which is comparable to helium plasma lamps and many synchrotron beamlines. We first describe the lamp and monochromator system and then characterize its output, with attention to those parameters which are of interest for photoemission experiments. Finally, we present angle-resolved photoemission spectroscopy data using the light source and compare its performance to a conventional helium plasma lamp.

  2. Analysis of junior high school students' difficulty in resolving rectangular conceptual problems

    Science.gov (United States)

    Utami, Aliksia Kristiana Dwi; Mardiyana, Pramudya, Ikrar

    2017-08-01

    Geometry is one part of the mathematics that must be learned in school and it has important effects on the development of creative thinking skills of learners, but in fact, there are some difficulties experienced by the students. This research focuses on analysis difficulty in resolving rectangular conceptual problems among junior high school students in every creative thinking skills level. This research used a descriptive method aimed to identify the difficulties and cause of the difficulties experienced by five students. The difficulties are associated with rectangular shapes and related problems. Data collection was done based on students' work through test, interview, and observations. The result revealed that student' difficulties in understanding the rectangular concept can be found at every creative thinking skills level. The difficulties are identifying the objects rectangular in the daily life except for a rectangle and square, analyzing the properties of rectangular shapes, and seeing the interrelationships between figures.

  3. Time-resolved x-ray spectra from laser-generated high-density plasmas

    Science.gov (United States)

    Andiel, U.; Eidmann, Klaus; Witte, Klaus-Juergen

    2001-04-01

    We focused frequency doubled ultra short laser pulses on solid C, F, Na and Al targets, K-shell emission was systematically investigated by time resolved spectroscopy using a sub-ps streak camera. A large number of laser shots can be accumulated when triggering the camera with an Auston switch system at very high temporal precision. The system provides an outstanding time resolution of 1.7ps accumulating thousands of laser shots. The time duration of the He-(alpha) K-shell resonance lines was observed in the range of (2-4)ps and shows a decrease with the atomic number. The experimental results are well reproduced by hydro code simulations post processed with an atomic kinetics code.

  4. Time resolved measurements of cathode fall in high frequency fluorescent lamps

    International Nuclear Information System (INIS)

    Hadrath, S; Garner, R C; Lieder, G H; Ehlbeck, J

    2007-01-01

    Measurements are presented of the time resolved cathode and anode falls of high frequency fluorescent lamps for a range of discharge currents typically encountered in dimming mode. Measurements were performed with the movable anode technique. Supporting spectroscopic emission measurements were made of key transitions (argon 420.1 nm and mercury 435.8 nm), whose onset coincide with cathode fall equalling the value associated with the energy, relative to the ground state, of the upper level of the respective transition. The measurements are in general agreement with the well-known understanding of dimmed lamp operation: peak cathode fall decreases with increasing lamp current and with increasing auxiliary coil heating. However, the time dependence of the measurements offers additional insight

  5. Spatially resolved electronic structure inside and outside the vortex cores of a high-temperature superconductor

    Science.gov (United States)

    Mitrović, V. F.; Sigmund, E. E.; Eschrig, M.; Bachman, H. N.; Halperin, W. P.; Reyes, A. P.; Kuhns, P.; Moulton, W. G.

    2001-10-01

    Puzzling aspects of high-transition-temperature (high-Tc) superconductors include the prevalence of magnetism in the normal state and the persistence of superconductivity in high magnetic fields. Superconductivity and magnetism generally are thought to be incompatible, based on what is known about conventional superconductors. Recent results, however, indicate that antiferromagnetism can appear in the superconducting state of a high-Tc superconductor in the presence of an applied magnetic field. Magnetic fields penetrate a superconductor in the form of quantized flux lines, each of which represents a vortex of supercurrents. Superconductivity is suppressed in the core of the vortex and it has been suggested that antiferromagnetism might develop there. Here we report the results of a high-field nuclear-magnetic-resonance (NMR) imaging experiment in which we spatially resolve the electronic structure of near-optimally doped YBa2Cu3O7-δ inside and outside vortex cores. Outside the cores, we find strong antiferromagnetic fluctuations, whereas inside we detect electronic states that are rather different from those found in conventional superconductors.

  6. Time-Resolved Tandem Faraday Cup Development for High Energy TNSA Particles

    Science.gov (United States)

    Padalino, S.; Simone, A.; Turner, E.; Ginnane, M. K.; Glisic, M.; Kousar, B.; Smith, A.; Sangster, C.; Regan, S.

    2015-11-01

    MTW and OMEGA EP Lasers at LLE utilize ultra-intense laser light to produce high-energy ion pulses through Target Normal Sheath Acceleration (TNSA). A Time Resolved Tandem Faraday Cup (TRTF) was designed and built to collect and differentiate protons from heavy ions (HI) produced during TNSA. The TRTF includes a replaceable thickness absorber capable of stopping a range of user-selectable HI emitted from TNSA plasma. HI stop within the primary cup, while less massive particles continue through and deposit their remaining charge in the secondary cup, releasing secondary electrons in the process. The time-resolved beam current generated in each cup will be measured on a fast storage scope in multiple channels. A charge-exchange foil at the TRTF entrance modifies the charge state distribution of HI to a known distribution. Using this distribution and the time of flight of the HI, the total HI current can be determined. Initial tests of the TRTF have been made using a proton beam produced by SUNY Geneseo's 1.7 MV Pelletron accelerator. A substantial reduction in secondary electron production, from 70% of the proton beam current at 2MeV down to 0.7%, was achieved by installing a pair of dipole magnet deflectors which successfully returned the electrons to the cups in the TRTF. Ultimately the TRTF will be used to normalize a variety of nuclear physics cross sections and stopping power measurements. Based in part upon work supported by a DOE NNSA Award#DE-NA0001944.

  7. High-performance coupled poro-hydro-mechanical models to resolve fluid escape pipes

    Science.gov (United States)

    Räss, Ludovic; Makhnenko, Roman; Podladchikov, Yury

    2017-04-01

    Field observations and laboratory experiments exhibit inelastic deformation features arising in many coupled settings relevant to geo-applications. These irreversible deformations and their specific patterns suggest a rather ductile or brittle mechanism, such as viscous creep or micro cracks, taking place on both geological (long) and human (short) timescales. In order to understand the underlying mechanisms responsible for these deformation features, there is a current need to accurately resolve the non-linearities inherent to strongly coupled physical processes. Among the large variety of modelling tools and softwares available nowadays in the community, very few are capable to efficiently solve coupled systems with high accuracy in both space and time and run efficiently on modern hardware. Here, we propose a robust framework to solve coupled multi-physics hydro-mechanical processes on very high spatial and temporal resolution in both two and three dimensions. Our software relies on the Finite-Difference Method and a pseudo-transient scheme is used to converge to the implicit solution of the system of poro-visco-elasto-plastic equations at each physical time step. The rheology including viscosity estimates for major reservoir rock types is inferred from novel lab experiments and confirms the ease of flow of sedimentary rocks. Our results propose a physical mechanism responsible for the generation of high permeability pathways in fluid saturated porous media and predict their propagation in rates observable on operational timescales. Finally, our software scales linearly on more than 5000 GPUs.

  8. Time resolved Thomson scattering measurements on a high pressure mercury lamp

    International Nuclear Information System (INIS)

    Vries, N de; Zhu, X; Kieft, E R; Mullen, J van der

    2005-01-01

    Time resolved Thomson scattering (TS) measurements have been performed on an ac driven high pressure mercury lamp. For this high intensity discharge (HID) lamp, TS is coherent and a coherent fitting routine, including rotational Raman calibration, was used to determine n e and T e from the measured spectrum. The maximum electron density and electron temperature obtained in the centre of the discharge varied in a time period of 5 ms between 1 x 10 21 m -3 e 21 m -3 and 6500 K e < 7100 K. In order to test the non-intrusive character of TS, we have derived a general expression for the heating of the electrons. By applying this to our mercury lamp and laser settings, we have confirmed the non-intrusiveness of our method. This is supported by the experimental findings. Furthermore, because the TS results were obtained directly, thus, without the local thermodynamic equilibrium (LTE) assumptions, they enabled us to follow the deviations from LTE as a function of time. Contrary to the generally made assumption that HID lamps are in LTE, we have found deviations from both the thermal and chemical equilibrium inside the high pressure mercury lamp at different phases of the applied current

  9. A High-mass Protobinary System with Spatially Resolved Circumstellar Accretion Disks and Circumbinary Disk

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, S.; Kluska, J.; Kreplin, A.; Bate, M.; Harries, T. J.; Hone, E.; Anugu, A. [School of Physics, Astrophysics Group, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Hofmann, K.-H.; Weigelt, G. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Monnier, J. D. [Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Avenue, Ann Arbor, MI 48109 (United States); De Wit, W. J. [ESO, Alonso de Cordova 3107, Vitacura, Santiago 19 (Chile); Wittkowski, M., E-mail: skraus@astro.ex.ac.uk [ESO, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)

    2017-01-20

    High-mass multiples might form via fragmentation of self-gravitational disks or alternative scenarios such as disk-assisted capture. However, only a few observational constraints exist on the architecture and disk structure of high-mass protobinaries and their accretion properties. Here, we report the discovery of a close (57.9 ± 0.2 mas = 170 au) high-mass protobinary, IRAS17216-3801, where our VLTI/GRAVITY+AMBER near-infrared interferometry allows us to image the circumstellar disks around the individual components with ∼3 mas resolution. We estimate the component masses to ∼20 and ∼18 M {sub ⊙} and find that the radial intensity profiles can be reproduced with an irradiated disk model, where the inner regions are excavated of dust, likely tracing the dust sublimation region in these disks. The circumstellar disks are strongly misaligned with respect to the binary separation vector, which indicates that the tidal forces did not have time to realign the disks, pointing toward a young dynamical age of the system. We constrain the distribution of the Br γ and CO-emitting gas using VLTI/GRAVITY spectro-interferometry and VLT/CRIRES spectro-astrometry and find that the secondary is accreting at a higher rate than the primary. VLT/NACO imaging shows L ′-band emission on (3–4)× larger scales than the binary separation, matching the expected dynamical truncation radius for the circumbinary disk. The IRAS17216-3801 system is ∼3× more massive and ∼5× more compact than other high-mass multiplies imaged at infrared wavelength and the first high-mass protobinary system where circumstellar and circumbinary dust disks could be spatially resolved. This opens exciting new opportunities for studying star–disk interactions and the role of multiplicity in high-mass star formation.

  10. An integrated approach using high time-resolved tools to study the origin of aerosols.

    Science.gov (United States)

    Di Gilio, A; de Gennaro, G; Dambruoso, P; Ventrella, G

    2015-10-15

    Long-range transport of natural and/or anthropogenic particles can contribute significantly to PM10 and PM2.5 concentrations and some European cities often fail to comply with PM daily limit values due to the additional impact of particles from remote sources. For this reason, reliable methodologies to identify long-range transport (LRT) events would be useful to better understand air pollution phenomena and support proper decision-making. This study explores the potential of an integrated and high time-resolved monitoring approach for the identification and characterization of local, regional and long-range transport events of high PM. In particular, the goal of this work was also the identification of time-limited event. For this purpose, a high time-resolved monitoring campaign was carried out at an urban background site in Bari (southern Italy) for about 20 days (1st-20th October 2011). The integration of collected data as the hourly measurements of inorganic ions in PM2.5 and their gas precursors and of the natural radioactivity, in addition to the analyses of aerosol maps and hourly back trajectories (BT), provided useful information for the identification and chemical characterization of local sources and trans-boundary intrusions. Non-sea salt (nss) sulfate levels were found to increase when air masses came from northeastern Europe and higher dispersive conditions of the atmosphere were detected. Instead, higher nitrate and lower nss-sulfate concentrations were registered in correspondence with air mass stagnation and attributed to local traffic source. In some cases, combinations of local and trans-boundary sources were observed. Finally, statistical investigations such as the principal component analysis (PCA) applied on hourly ion concentrations and the cluster analyses, the Potential Source Contribution Function (PSCF) and the Concentration Weighted Trajectory (CWT) models computed on hourly back-trajectories enabled to complete a cognitive framework

  11. Rapid and highly resolving associative affective learning: convergent electro- and magnetoencephalographic evidence from vision and audition.

    Science.gov (United States)

    Steinberg, Christian; Bröckelmann, Ann-Kathrin; Rehbein, Maimu; Dobel, Christian; Junghöfer, Markus

    2013-03-01

    Various pathway models for emotional processing suggest early prefrontal contributions to affective stimulus evaluation. Yet, electrophysiological evidence for such rapid modulations is still sparse. In a series of four MEG/EEG studies which investigated associative learning in vision and audition using a novel MultiCS Conditioning paradigm, many different neutral stimuli (faces, tones) were paired with aversive and appetitive events in only two to three learning instances. Electrophysiological correlates of neural activity revealed highly significant amplified processing for conditioned stimuli within distributed prefrontal and sensory cortical networks. In both, vision and audition, affect-specific responses occurred in two successive waves of rapid (vision: 50-80 ms, audition: 25-65 ms) and mid-latency (vision: >130 ms, audition: >100 ms) processing. Interestingly, behavioral measures indicated that MultiCS Conditioning successfully prevented contingency awareness. We conclude that affective processing rapidly recruits highly elaborate and widely distributed networks with substantial capacity for fast learning and excellent resolving power. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Invited Article: High resolution angle resolved photoemission with tabletop 11 eV laser

    Energy Technology Data Exchange (ETDEWEB)

    He, Yu; Vishik, Inna M.; Yi, Ming; Yang, Shuolong; Lee, James J.; Chen, Sudi; Rebec, Slavko N.; Leuenberger, Dominik; Shen, Zhi-Xun [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Liu, Zhongkai [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); Zong, Alfred [Department of Physics, Stanford University, Stanford, California 94305 (United States); Jefferson, C. Michael; Merriam, Andrew J. [Lumeras LLC, 207 McPherson St, Santa Cruz, California 95060 (United States); Moore, Robert G.; Kirchmann, Patrick S. [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

    2016-01-15

    We developed a table-top vacuum ultraviolet (VUV) laser with 113.778 nm wavelength (10.897 eV) and demonstrated its viability as a photon source for high resolution angle-resolved photoemission spectroscopy (ARPES). This sub-nanosecond pulsed VUV laser operates at a repetition rate of 10 MHz, provides a flux of 2 × 10{sup 12} photons/s, and enables photoemission with energy and momentum resolutions better than 2 meV and 0.012 Å{sup −1}, respectively. Space-charge induced energy shifts and spectral broadenings can be reduced below 2 meV. The setup reaches electron momenta up to 1.2 Å{sup −1}, granting full access to the first Brillouin zone of most materials. Control over the linear polarization, repetition rate, and photon flux of the VUV source facilitates ARPES investigations of a broad range of quantum materials, bridging the application gap between contemporary low energy laser-based ARPES and synchrotron-based ARPES. We describe the principles and operational characteristics of this source and showcase its performance for rare earth metal tritellurides, high temperature cuprate superconductors, and iron-based superconductors.

  13. Highly efficient detection of paclobutrazol in environmental water and soil samples by time-resolved fluoroimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhenjiang, E-mail: lzj1984@ujs.edu.cn [School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); Wei, Xi [School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China); The Affiliated First People' s Hospital of Jiangsu University, Zhenjiang 212002 (China); Ren, Kewei; Zhu, Gangbing; Zhang, Zhen; Wang, Jiagao; Du, Daolin [School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2016-11-01

    A fast and ultrasensitive indirect competitive time-resolved fluoroimmunoassay (TRFIA) was developed for the analysis of paclobutrazol in environmental water and soil samples. Paclobutrazol hapten was synthesized and conjugated to bovine serum albumin (BSA) for producing polyclonal antibodies. Under optimal conditions, the 50% inhibitory concentration (IC{sub 50} value) and limit of detection (LOD, IC{sub 20} value) were 1.09 μg L{sup −} {sup 1} and 0.067 μg L{sup −} {sup 1}, respectively. The LOD of TRFIA was improved 30-fold compared to the already reported ELISA. There was almost no cross-reactivity of the antibody with the other structural analogues of triazole compounds, indicating that the antibody had high specificity. The average recoveries from spiked samples were in the range from 80.2% to 104.7% with a relative standard deviation of 1.0–9.5%. The TRFIA results for the real samples were in good agreement with that obtained by high-performance liquid chromatography analyses. The results indicate that the established TRFIA has potential application for screening paclobutrazol in environmental samples. - Highlights: • The approach to design and synthesize the PBZ hapten was more straightforward. • A rapid and ultrasensitive TRFIA was developed and applied to the screening of PBZ. • The TRFIA for real soil samples showed reliability and high correlation with HPLC. • The PBZ TRFIA showed high sensitivity, simple operation, a wide range of quantitative analyses and no radioactive hazards.

  14. A high-order time-accurate interrogation method for time-resolved PIV

    International Nuclear Information System (INIS)

    Lynch, Kyle; Scarano, Fulvio

    2013-01-01

    A novel method is introduced for increasing the accuracy and extending the dynamic range of time-resolved particle image velocimetry (PIV). The approach extends the concept of particle tracking velocimetry by multiple frames to the pattern tracking by cross-correlation analysis as employed in PIV. The working principle is based on tracking the patterned fluid element, within a chosen interrogation window, along its individual trajectory throughout an image sequence. In contrast to image-pair interrogation methods, the fluid trajectory correlation concept deals with variable velocity along curved trajectories and non-zero tangential acceleration during the observed time interval. As a result, the velocity magnitude and its direction are allowed to evolve in a nonlinear fashion along the fluid element trajectory. The continuum deformation (namely spatial derivatives of the velocity vector) is accounted for by adopting local image deformation. The principle offers important reductions of the measurement error based on three main points: by enlarging the temporal measurement interval, the relative error becomes reduced; secondly, the random and peak-locking errors are reduced by the use of least-squares polynomial fits to individual trajectories; finally, the introduction of high-order (nonlinear) fitting functions provides the basis for reducing the truncation error. Lastly, the instantaneous velocity is evaluated as the temporal derivative of the polynomial representation of the fluid parcel position in time. The principal features of this algorithm are compared with a single-pair iterative image deformation method. Synthetic image sequences are considered with steady flow (translation, shear and rotation) illustrating the increase of measurement precision. An experimental data set obtained by time-resolved PIV measurements of a circular jet is used to verify the robustness of the method on image sequences affected by camera noise and three-dimensional motions. In

  15. Evidence for intermittency and a truncated power law from highly resolved aphid movement data.

    Science.gov (United States)

    Mashanova, Alla; Oliver, Tom H; Jansen, Vincent A A

    2010-01-06

    Power laws are increasingly used to describe animal movement. Despite this, the use of power laws has been criticized on both empirical and theoretical grounds, and alternative models based on extensions of conventional random walk theory (Brownian motion) have been suggested. In this paper, we analyse a large volume of data of aphid walking behaviour (65,068 data points), which provides a highly resolved dataset to investigate the pattern of movement. We show that aphid movement is intermittent--with alternations of a slow movement with frequent change of direction and a fast, relatively directed movement--and that the fast movement consists of two phases--a strongly directed phase that gradually changes into an uncorrelated random walk. By measuring the mean-squared displacement and the duration of non-stop movement episodes we found that both spatial and temporal aspects of aphid movement are best described using a truncated power law approach. We suggest that the observed spatial pattern arises from the duration of non-stop movement phases rather than from correlations in turning angles. We discuss the implications of these findings for interpreting movement data, such as distinguishing between movement and non-movement, and the effect of the range of data used in the analysis on the conclusions.

  16. High-resolution angle-resolved photoemission investigation of potassium and phosphate tungsten bronzes

    International Nuclear Information System (INIS)

    Paul, Sanhita; Kumari, Spriha; Raj, Satyabrata

    2016-01-01

    Highlights: • Electronic structure of potassium and phosphate tungsten bronzes. • Origin of transport anomalies in bronzes. • Flat segments of Fermi surfaces are connected by a nesting vector, q. • Nesting driven charge-density wave is responsible for the anomalies. - Abstract: We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) and density functional ab initio theoretical calculation to study the electronic structure of potassium (K_0_._2_5WO_3) and phosphate (P_4W_1_2O_4_4) tungsten bronzes. We have experimentally determined the band dispersions and Fermi surface topology of these bronzes and compared with our theoretical calculations and a fair agreement has been seen between them. Our experimental as well as theoretical investigation elucidates the origin of transport anomalies in these bronzes. The Fermi surfaces of these bronzes consist of flat patches, which can be connected with each other by a constant nesting wave vector, q. The scattering wave vectors found from diffraction measurements match with these nesting vectors and the anomalies in the transport properties of these bronzes can be well explained by the evolution of charge-density wave with a partial nesting between the flat segments of the Fermi surfaces.

  17. Highly-resolved modeling of personal transportation energy consumption in the United States

    International Nuclear Information System (INIS)

    Muratori, Matteo; Moran, Michael J.; Serra, Emmanuele; Rizzoni, Giorgio

    2013-01-01

    This paper centers on the estimation of the total primary energy consumption for personal transportation in the United States, to include gasoline and/or electricity consumption, depending on vehicle type. The bottom-up sector-based estimation method introduced here contributes to a computational tool under development at The Ohio State University for assisting decision making in energy policy, pricing, and investment. In order to simulate highly-resolved consumption profiles three main modeling steps are needed: modeling the behavior of drivers, generating realistic driving profiles, and simulating energy consumption of different kinds of vehicles. The modeling proposed allows for evaluating the impact of plug-in electric vehicles on the electric grid – especially at the distribution level. It can serve as a tool to compare different vehicle types and assist policy-makers in estimating their impact on primary energy consumption and the role transportation can play to reduce oil dependency. - Highlights: • Modeling primary energy consumption for personal transportation in the United States. • Behavior of drivers has been simulated in order to establish when driving events occur and the length of each event. • Realistic driving profiles for each driving event are generated using a stochastic model. • The model allows for comparing the initial cost of different vehicles and their expected energy-use operating cost. • Evaluation of the impact of PEVs on the electric grid – especially at the distribution level – can be performed

  18. Highly resolved measurements of atmospheric turbulence with the new 2d-Atmospheric Laser Cantilever Anemometer

    International Nuclear Information System (INIS)

    Jeromin, A; Schaffarczyk, A P; Puczylowski, J; Peinke, J; Hölling, M

    2014-01-01

    For the investigation of atmospheric turbulent flows on small scales a new anemometer was developed, the so-called 2d-Atmospheric Laser Cantilever Anemometer (2d-ALCA). It performs highly resolved measurements with a spatial resolution in millimeter range and temporal resolution in kHz range, thus detecting very small turbulent structures. The anemometer is a redesign of the successfully operating 2d-LCA for laboratory application. The new device was designed to withstand hostile operating environments (rain and saline, humid air). In February 2012, the 2d-ALCA was used for the first time in a test field. The device was mounted in about 53 m above ground level on a lattice tower near the German North Sea coast. Wind speed was measured by the 2d-ALCA at 10 kHz sampling rate and by cup anemometers at 1 Hz. The instantaneous wind speed ranged from 8 m/s to 19 m/s at an average turbulence level of about 7 %. Wind field characteristics were analyzed based on cup anemometer as well as 2d-ALCA. The combination of both devices allowed the study of atmospheric turbulence over several magnitudes in turbulent scales

  19. Spatially resolving the very high energy emission from MGRO J2019+37 with VERITAS

    International Nuclear Information System (INIS)

    Aliu, E.; Errando, M.; Aune, T.; Behera, B.; Chen, X.; Federici, S.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Berger, K.; Bird, R.; Bouvier, A.; Ciupik, L.; Connolly, M. P.; Cui, W.; Dumm, J.; Dwarkadas, V. V.; Falcone, A.

    2014-01-01

    We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (∼2°) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 ± 0.4. VER J2019+378 is a bright extended (∼1°) source that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2–104. Its spectrum in the range 1-30 TeV is well fit with a power-law model of photon index 1.75 ± 0.3, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.

  20. Study of combustion properties of a solid propellant by highly time-resolved passive FTIR

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liming; Zhang, Lin; Li, Yan; Liu, Bingping; Wang, Junde [Laboratory of Advanced Spectroscopy, Nanjing University of Science and Technology, Nanjing 210014 (China)

    2006-10-15

    With a time resolution of 0.125 s and a spectral resolution of 4 cm{sup -1}, emission spectra of the combustion process of a solid propellant were recorded by highly time-resolved passive FTIR. Some gaseous combustion products, such as H{sub 2}O, CO, CO{sub 2}, NO and HCl, were distinguished by the characteristic emission band of each molecule. The equation for flame temperature calculation based on the diatomic molecule emission fine structure theory was improved through judicious utilization of the spectral running number 'm' which makes the temperature measurement simpler and faster. Some combustion information of the solid propellant had been given including the characteristic spectral profile, the distribution of the absolute spectral energy, the distribution of the combustion flame temperature, and the concentration distributions of HCl and NO versus burning time. The results will provide theoretical and experimental bases for improving the formula and raising combustion efficiency of solid propellant, and developing the design of rocket motor, infrared guidance and antiguidance systems. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  1. Time-resolved measurements of highly-polymerised negative ions in rf silane plasma deposition experiments

    International Nuclear Information System (INIS)

    Howling, A.A.; Sansonnens, L.; Dorier, J.L.; Hollenstein, C.

    1993-07-01

    The time-resolved fluxes of negative polysilicon hydride ions from a power-modulated rf silane plasma have been measured by quadrupole mass spectrometry and modeled using a simple polymerisation scheme. Experiments were performed with plasma parameters suitable for high-quality amorphous silicon deposition. Polysilicon hydride anions diffuse from the plasma with low energy (approximately 0.5 eV) during the afterglow after the electron density has decayed and the sheath fields have collapsed. The mass-dependence of the temporal behavior of the anion loss flux demonstrates that the plasma composition is influenced by the modulation frequency. The negative species attain much higher masses than the positive or neutral species, and anions containing as many as sixteen silicon atoms have been observed, corresponding to the 500 amu limit of the mass spectrometer. This suggests that negative ions could be the precursors to particle formation. Ion-molecule and ion-ion reactions are discussed and a simple negative ion polymerisation scheme is proposed which qualitatively reproduces the experimental results. The model shows that the densities of high mass negative ions in the plasma are strongly reduced by modulation frequencies near 1 kHz. Each plasma period is then too short for the polymerisation chain to propagate to high masses before the elementary anions are lost in each subsequent afterglow period. This explains why modulation of the rf power can reduce particle contamination. We conclude that, for the case of silane rf plasmas, the initiation steps which ultimately lead to particle contamination proceed by negative ion polymerisation. (author) 15 figs., 72 refs

  2. The ReactorSTM: Atomically resolved scanning tunneling microscopy under high-pressure, high-temperature catalytic reaction conditions

    Energy Technology Data Exchange (ETDEWEB)

    Herbschleb, C. T.; Tuijn, P. C. van der; Roobol, S. B.; Navarro, V.; Bakker, J. W.; Liu, Q.; Stoltz, D.; Cañas-Ventura, M. E.; Verdoes, G.; Spronsen, M. A. van; Bergman, M.; Crama, L.; Taminiau, I.; Frenken, J. W. M., E-mail: frenken@physics.leidenuniv.nl [Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. box 9504, 2300 RA Leiden (Netherlands); Ofitserov, A.; Baarle, G. J. C. van [Leiden Probe Microscopy B.V., J.H. Oortweg 21, 2333 CH Leiden (Netherlands)

    2014-08-15

    To enable atomic-scale observations of model catalysts under conditions approaching those used by the chemical industry, we have developed a second generation, high-pressure, high-temperature scanning tunneling microscope (STM): the ReactorSTM. It consists of a compact STM scanner, of which the tip extends into a 0.5 ml reactor flow-cell, that is housed in a ultra-high vacuum (UHV) system. The STM can be operated from UHV to 6 bars and from room temperature up to 600 K. A gas mixing and analysis system optimized for fast response times allows us to directly correlate the surface structure observed by STM with reactivity measurements from a mass spectrometer. The in situ STM experiments can be combined with ex situ UHV sample preparation and analysis techniques, including ion bombardment, thin film deposition, low-energy electron diffraction and x-ray photoelectron spectroscopy. The performance of the instrument is demonstrated by atomically resolved images of Au(111) and atom-row resolution on Pt(110), both under high-pressure and high-temperature conditions.

  3. Highly resolved global distribution of tropospheric NO2 using GOME narrow swath mode data

    Directory of Open Access Journals (Sweden)

    S. Beirle

    2004-01-01

    Full Text Available The Global Ozone Monitoring Experiment (GOME allows the retrieval of tropospheric vertical column densities (VCDs of NO2 on a global scale. Regions with enhanced industrial activity can clearly be detected, but the standard spatial resolution of the GOME ground pixels (320x40km2 is insufficient to resolve regional trace gas distributions or individual cities. Every 10 days within the nominal GOME operation, measurements are executed in the so called narrow swath mode with a much better spatial resolution (80x40km2. We use this data (1997-2001 to construct a detailed picture of the mean global tropospheric NO2 distribution. Since - due to the narrow swath - the global coverage of the high resolution observations is rather poor, it has proved to be essential to deseasonalize the single narrow swath mode observations to retrieve adequate mean maps. This is done by using the GOME backscan information. The retrieved high resolution map illustrates the shortcomings of the standard size GOME pixels and reveals an unprecedented wealth of details in the global distribution of tropospheric NO2. Localised spots of enhanced NO2 VCD can be directly associated to cities, heavy industry centers and even large power plants. Thus our result helps to check emission inventories. The small spatial extent of NO2 'hot spots' allows us to estimate an upper limit of the mean lifetime of boundary layer NOx of 17h on a global scale. The long time series of GOME data allows a quantitative comparison of the narrow swath mode data to the nominal resolution. Thus we can analyse the dependency of NO2 VCDs on pixel size. This is important for comparing GOME data to results of new satellite instruments like SCIAMACHY (launched March 2002 on ENVISAT, OMI (launched July 2004 on AURA or GOME II (to be launched 2005 with an improved spatial resolution.

  4. Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland

    DEFF Research Database (Denmark)

    Rathmann, N. M.; Hvidberg, C. S.; Solgaard, A. M.

    2017-01-01

    The seasonal response to surface melting of the Northeast Greenland Ice Stream outlets, Zachariae and 79N, is investigated using new highly temporally resolved surface velocity maps for 2016 combined with numerical modelling. The seasonal speed-up at 79N of 0.15km/yr is suggested to be driven by ...

  5. Velocity-Resolved LES (VR-LES) technique for simulating turbulent transport of high Schmidt number passive scalars

    Science.gov (United States)

    Verma, Siddhartha; Blanquart, Guillaume; P. K. Yeung Collaboration

    2011-11-01

    Accurate simulation of high Schmidt number scalar transport in turbulent flows is essential to studying pollutant dispersion, weather, and several oceanic phenomena. Batchelor's theory governs scalar transport in such flows, but requires further validation at high Schmidt and high Reynolds numbers. To this end, we use a new approach with the velocity field fully resolved, but the scalar field only partially resolved. The grid used is fine enough to resolve scales up to the viscous-convective subrange where the decaying slope of the scalar spectrum becomes constant. This places the cutoff wavenumber between the Kolmogorov scale and the Batchelor scale. The subgrid scale terms, which affect transport at the supergrid scales, are modeled under the assumption that velocity fluctuations are negligible beyond this cutoff wavenumber. To ascertain the validity of this technique, we performed a-priori testing on existing DNS data. This Velocity-Resolved LES (VR-LES) technique significantly reduces the computational cost of turbulent simulations of high Schmidt number scalars, and yet provides valuable information of the scalar spectrum in the viscous-convective subrange.

  6. Space-resolved characterization of high frequency atmospheric-pressure plasma in nitrogen, applying optical emission spectroscopy and numerical simulation

    International Nuclear Information System (INIS)

    Rajasekaran, Priyadarshini; Ruhrmann, Cornelia; Bibinov, Nikita; Awakowicz, Peter

    2011-01-01

    Averaged plasma parameters such as electron distribution function and electron density are determined by characterization of high frequency (2.4 GHz) nitrogen plasma using both experimental methods, namely optical emission spectroscopy (OES) and microphotography, and numerical simulation. Both direct and step-wise electron-impact excitation of nitrogen emissions are considered. The determination of space-resolved electron distribution function, electron density, rate constant for electron-impact dissociation of nitrogen molecule and the production of nitrogen atoms, applying the same methods, is discussed. Spatial distribution of intensities of neutral nitrogen molecule and nitrogen molecular ion from the microplasma is imaged by a CCD camera. The CCD images are calibrated using the corresponding emissions measured by absolutely calibrated OES, and are then subjected to inverse Abel transformation to determine space-resolved intensities and other parameters. The space-resolved parameters are compared, respectively, with the averaged parameters, and an agreement between them is established. (paper)

  7. Time-resolved PIV technique for high temporal resolution measurement of mechanical prosthetic aortic valve fluid dynamics.

    Science.gov (United States)

    Kaminsky, R; Morbiducci, U; Rossi, M; Scalise, L; Verdonck, P; Grigioni, M

    2007-02-01

    Prosthetic heart valves (PHVs) have been used to replace diseased native valves for more than five decades. Among these, mechanical PHVs are the most frequently implanted. Unfortunately, these devices still do not achieve ideal behavior and lead to many complications, many of which are related to fluid mechanics. The fluid dynamics of mechanical PHVs are particularly complex and the fine-scale characteristics of such flows call for very accurate experimental techniques. Adequate temporal resolution can be reached by applying time-resolved PIV, a high-resolution dynamic technique which is able to capture detailed chronological changes in the velocity field. The aim of this experimental study is to investigate the evolution of the flow field in a detailed time domain of a commercial bileaflet PHV in a mock-loop mimicking unsteady conditions, by means of time-resolved 2D Particle Image Velocimetry (PIV). The investigated flow field corresponded to the region immediately downstream of the valve plane. Spatial resolution as in "standard" PIV analysis of prosthetic valve fluid dynamics was used. The combination of a Nd:YLF high-repetition-rate double-cavity laser with a high frame rate CMOS camera allowed a detailed, highly temporally resolved acquisition (up to 10000 fps depending on the resolution) of the flow downstream of the PHV. Features that were observed include the non-homogeneity and unsteadiness of the phenomenon and the presence of large-scale vortices within the field, especially in the wake of the valve leaflets. Furthermore, we observed that highly temporally cycle-resolved analysis allowed the different behaviors exhibited by the bileaflet valve at closure to be captured in different acquired cardiac cycles. By accurately capturing hemodynamically relevant time scales of motion, time-resolved PIV characterization can realistically be expected to help designers in improving PHV performance and in furnishing comprehensive validation with experimental data

  8. Study of resolved high-psub(T) neutral pions at the CERN ISR

    International Nuclear Information System (INIS)

    Kourkoumelis, C.; Resvanis, L.K.; Voulgaris, G.; Filippas, T.A.; Fokitis, E.; Fabjan, C.W.; Fields, T.; Lissauer, D.; Mannelli, I.; Mouzourakis, P.; Nakamura, K.; Nappi, A.; Willis, W.J.; Goldberg, M.; Lankford, A.J.

    1979-01-01

    The inclusive production of π 0 at large values of psub(T) in pp collisions at the ISR has been studied. In this experiment the two photons are resolved and separately measured for psub(T) values of up to 6 GeV/c, giving confidence that the desired signal has been separated from various backgrounds. (Auth.)

  9. Size-Resolved Penetration Through High-Efficiency Filter Media Typically Used for Aerosol Sampling

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Ondráček, Jakub; Ždímal, Vladimír

    2015-01-01

    Roč. 49, č. 4 (2015), s. 239-249 ISSN 0278-6826 R&D Projects: GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 Keywords : filters * size-resolved penetration * atmospheric aerosol sampling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.953, year: 2015

  10. Size-resolved atmospheric particulate polysaccharides in the high summer Arctic

    Science.gov (United States)

    Leck, C.; Gao, Q.; Mashayekhy Rad, F.; Nilsson, U.

    2013-12-01

    Size-resolved aerosol samples for subsequent quantitative determination of polymer sugars (polysaccharides) after hydrolysis to their subunit monomers (monosaccharides) were collected in surface air over the central Arctic Ocean during the biologically most active summer period. The analysis was carried out by novel use of liquid chromatography coupled with highly selective and sensitive tandem mass spectrometry. Polysaccharides were detected in particle sizes ranging from 0.035 to 10 μm in diameter with distinct features of heteropolysaccharides, enriched in xylose, glucose + mannose as well as a substantial fraction of deoxysugars. Polysaccharides, containing deoxysugar monomers, showed a bimodal size structure with about 70% of their mass found in the Aitken mode over the pack ice area. Pentose (xylose) and hexose (glucose + mannose) had a weaker bimodal character and were largely found with super-micrometer sizes and in addition with a minor sub-micrometer fraction. The concentration of total hydrolysable neutral sugars (THNS) in the samples collected varied over two orders of magnitude (1 to 160 pmol m-3) in the super-micrometer size fraction and to a somewhat lesser extent in sub-micrometer particles (4 to 140 pmol m-3). Lowest THNS concentrations were observed in air masses that had spent more than five days over the pack ice. Within the pack ice area, about 53% of the mass of hydrolyzed polysaccharides was detected in sub-micrometer particles. The relative abundance of sub-micrometer hydrolyzed polysaccharides could be related to the length of time that the air mass spent over pack ice, with the highest fraction (> 90%) observed for > 7 days of advection. The aerosol samples collected onboard ship showed similar monosaccharide composition, compared to particles generated experimentally in situ at the expedition's open lead site. This supports the existence of a primary particle source of polysaccharide containing polymer gels from open leads by bubble

  11. Development of a software system for spatial resolved trace analysis of high performance materials with SIMS

    International Nuclear Information System (INIS)

    Brunner, Ch. H.

    1997-09-01

    The following work is separated into two distinctly different parts. The first one is dealing with the SIMSScan software project, an application system for secondary ion mass spectrometry. This application system primarily lays down the foundation, for the research activity introduced in the second part of this work. SIMSScan is an application system designed to provide data acquisition routines for different requirements in the field of secondary ion mass spectroscopy. The whole application package is divided into three major sections, each one dealing with specific measurement tasks. Various supporting clients and wizards, providing extended functionality to the main application, build the core of the software. The MassScan as well as the DepthScan module incorporate the SIMS in the direct imaging or stigmatic mode and are featuring the capabilities for mass spectra recording or depth profile analysis. In combination with an image recording facility the DepthScan module features the capability of spatial resolved material analysis - 3D SIMS. The RasterScan module incorporates the SIMS in scanning mode and supports an fiber optical link for optimized data transfer. The primary goal of this work is to introduce the basic ideas behind the implementation of the main application modules and the supporting clients. Furthermore, it is the intention to lay down the foundation for further developments. At the beginning a short introduction into the paradigm of object oriented programming as well as Windows TM programming is given. Besides explaining the basic ideas behind the Doc/View application architecture the focus is mainly shifted to the routines controlling the SIMS hardware and the basic concepts of multithreaded programming. The elementary structures of the view and document objects is discussed in detail only for the MassScan module, because the ideas behind data abstraction and encapsulation are quite similar. The second part introduces the research activities

  12. Time-resolved x-ray diffraction measurement of C60 under high pressure and temperature using synchrotron radiation

    International Nuclear Information System (INIS)

    Horikawa, T; Suito, K; Kobayashi, M; Onodera, A

    2002-01-01

    C 60 has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C 60 structure are presented and the relevance to the hardness of materials derived from C 60 is discussed

  13. Highly resolved early Eocene food webs show development of modern trophic structure after the end-Cretaceous extinction

    OpenAIRE

    Dunne, Jennifer A.; Labandeira, Conrad C.; Williams, Richard J.

    2014-01-01

    Generalities of food web structure have been identified for extant ecosystems. However, the trophic organization of ancient ecosystems is unresolved, as prior studies of fossil webs have been limited by low-resolution, high-uncertainty data. We compiled highly resolved, well-documented feeding interaction data for 700 taxa from the 48 million-year-old latest early Eocene Messel Shale, which contains a species assemblage that developed after an interval of protracted environmental and biotal c...

  14. Note: Retrofitting an analog spectrometer for high resolving power in NUV-NIR

    Science.gov (United States)

    Taylor, Andrew S.; Batishchev, Oleg V.

    2017-11-01

    We demonstrate how an older spectrometer designed for photographic films can be efficiently retrofitted with a narrow laser-cut slit and a modern μm-pixel-size imaging CMOS camera, yielding sub-pm resolution in the broad near ultraviolet to near infrared (NUV-NIR) spectral range. Resolving power approaching 106 is achieved. Such digital retrofitting of an analog instrument is practical for research and teaching laboratories.

  15. Time-resolved studies of ultrarapid solidification of highly undercooled molten silicon formed by pulsed laser irradiation

    International Nuclear Information System (INIS)

    Lowndes, D.H.; Jellison, G.E. Jr.; Wood, R.F.; Carpenter, R.

    1984-01-01

    This paper reports new results of nanosecond-resolution time-resolved optical reflectivity measurements, during pulsed excimer (KrF, 248 nm) laser irradiation of Si-implanted amorphous (a) silicon layers, which, together with model calculations and post-irradiation TEM measurements, have allowed us to study both the transformation of a-Si to a highly undercooled liquid (l) phase and the subsequent ultrarapid solidification process

  16. A high-efficiency spin-resolved photoemission spectrometer combining time-of-flight spectroscopy with exchange-scattering polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Jozwiak, Chris M.; Graff, Jeff; Lebedev, Gennadi; Andresen, Nord; Schmid, Andreas; Fedorov, Alexei; El Gabaly, Farid; Wan, Weishi; Lanzara, Alessandra; Hussain, Zahid

    2010-04-13

    We describe a spin-resolved electron spectrometer capable of uniquely efficient and high energy resolution measurements. Spin analysis is obtained through polarimetry based on low-energy exchange scattering from a ferromagnetic thin-film target. This approach can achieve a similar analyzing power (Sherman function) as state-of-the-art Mott scattering polarimeters, but with as much as 100 times improved efficiency due to increased reflectivity. Performance is further enhanced by integrating the polarimeter into a time-of-flight (TOF) based energy analysis scheme with a precise and flexible electrostatic lens system. The parallel acquisition of a range of electron kinetic energies afforded by the TOF approach results in an order of magnitude (or more) increase in efficiency compared to hemispherical analyzers. The lens system additionally features a 90 degrees bandpass filter, which by removing unwanted parts of the photoelectron distribution allows the TOF technique to be performed at low electron drift energy and high energy resolution within a wide range of experimental parameters. The spectrometer is ideally suited for high-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES), and initial results are shown. The TOF approach makes the spectrometer especially ideal for time-resolved spin-ARPES experiments.

  17. High-accuracy resolver-to-digital conversion via phase locked loop based on PID controller

    Science.gov (United States)

    Li, Yaoling; Wu, Zhong

    2018-03-01

    The problem of resolver-to-digital conversion (RDC) is transformed into the problem of angle tracking control, and a phase locked loop (PLL) method based on PID controller is proposed in this paper. This controller comprises a typical PI controller plus an incomplete differential which can avoid the amplification of higher-frequency noise components by filtering the phase detection error with a low-pass filter. Compared with conventional ones, the proposed PLL method makes the converter a system of type III and thus the conversion accuracy can be improved. Experimental results demonstrate the effectiveness of the proposed method.

  18. Time-resolved spectroscopy of plasma resonances in highly excited silicon and germanium

    International Nuclear Information System (INIS)

    Huang, C.Y.; Malvezzi, A.M.; Bloembergen, N.; Kurz, H.

    1985-01-01

    The dynamics of the electron-hole plasma in silicon and germanium samples irradiated by 20 ps. 532 nm laser pulses has been investigated in the near infrared by the time-resolved picosecond optical spectroscopy. The experimental reflectivities and transmission are compared with the predictions of the thermal model for degenerate carrier distributions through the Drude formalism. Above a certain fluence, a significant deviation between measured and calculated values indicates a strong increase of the recombination rate as soon as the plasma resonances become comparable with the band gaps. These new plasmon-aided recombination channels are particularly pronounced in germanium. 15 refs., 8 figs

  19. Time resolved high frequency spectrum of Br2 molecules using pulsed photoacoustic technique.

    Science.gov (United States)

    Yehya, Fahem; Chaudhary, A K

    2013-11-01

    The paper reports the time resolved spectral distribution of higher order acoustic modes generated in Br2 molecules using pulsed Photoacoustic (PA) technique. New time resolved vibrational spectrum of Br2 molecules are recorded using a single 532nm, pulses of 7ns duration at 10Hz repetition rate obtained from Q-switched Nd:YAG laser. Frank-Condon principle based assignments confirms the presence of 12 numbers of (ν″-ν') vibrational transitions covered by a single 532+2nm pulse profile. Inclusions of higher order zeroth modes in Bassel's function expansion series shows the probability of overlapping of different types of acoustic modes in the designed PA cells. These modes appear in the form of clusters which occupies higher frequency range. The study of decay behavior of PA signal with respect to time confirms the photolysis of Br2 at 532nm wavelength. In addition, the shifting and clustering effect of cavity eigen modes in Br2 molecules have been studied between 1 and 10ms time scale. The estimated Q-factor of PA cell (l=16cm, R=1.4cm) is 145±4 at 27kHz frequency. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Spin-resolved photoelectron spectroscopy using femtosecond extreme ultraviolet light pulses from high-order harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Plötzing, M.; Adam, R., E-mail: r.adam@fz-juelich.de; Weier, C.; Plucinski, L.; Schneider, C. M. [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-6), 52425 Jülich (Germany); Eich, S.; Emmerich, S.; Rollinger, M.; Aeschlimann, M. [University of Kaiserslautern and Research Center OPTIMAS, 67663 Kaiserslautern (Germany); Mathias, S. [Georg-August-Universität Göttingen, I. Physikalisches Institut, 37077 Göttingen (Germany)

    2016-04-15

    The fundamental mechanism responsible for optically induced magnetization dynamics in ferromagnetic thin films has been under intense debate since almost two decades. Currently, numerous competing theoretical models are in strong need for a decisive experimental confirmation such as monitoring the triggered changes in the spin-dependent band structure on ultrashort time scales. Our approach explores the possibility of observing femtosecond band structure dynamics by giving access to extended parts of the Brillouin zone in a simultaneously time-, energy- and spin-resolved photoemission experiment. For this purpose, our setup uses a state-of-the-art, highly efficient spin detector and ultrashort, extreme ultraviolet light pulses created by laser-based high-order harmonic generation. In this paper, we present the setup and first spin-resolved spectra obtained with our experiment within an acquisition time short enough to allow pump-probe studies. Further, we characterize the influence of the excitation with femtosecond extreme ultraviolet pulses by comparing the results with data acquired using a continuous wave light source with similar photon energy. In addition, changes in the spectra induced by vacuum space-charge effects due to both the extreme ultraviolet probe- and near-infrared pump-pulses are studied by analyzing the resulting spectral distortions. The combination of energy resolution and electron count rate achieved in our setup confirms its suitability for spin-resolved studies of the band structure on ultrashort time scales.

  1. Time-resolved studies at PETRA III with a highly repetitive synchronized laser system

    Energy Technology Data Exchange (ETDEWEB)

    Schlie, Mortiz

    2013-09-15

    Atomic and molecular processes can nowadays be directly followed in the time domain. This is a core technique for a better understanding of the involved fundamental physics, thus auguring new applications in the future as well. Usually the so-called pump-probe technique making use of two synchronized ultrashort light pulses is utilized to obtain this time-resolved data. In this work, the development and characterization of a synchronization system enabling such pump-probe studies at the storage ring PETRA III in combination with an external, then synchronized fs-laser system is described. The synchronization is based on an extended PLL approach with three interconnected feedback loops allowing to monitor short-time losses of the lock and thus prevent them. This way, the jitter between the laser PHAROS and the PETRA III reference signal is reduced to {sigma} <5 ps. Thus the system allows to conduct experiments at a repetition rate of 130 kHz with a temporal resolution limited only by the X-ray pulse length. A major emphasis in the fundamental introductory chapters is an intuitive explanation of the basic principles of phase locked loops and the different aspects of phase noise to allow a deeper understanding of the synchronization. Furthermore, first pump-probe experiments conducted at different beamlines at PETRA III are presented, demonstrating the usability of the laser system in a scientific environment as well. In first characterizing experiments the pulse duration of PETRA III X-ray pulses has been measured to be 90 ps FWHM. In particular, there have been time resolved X-ray absorption spectroscopy experiments on Gaq3 and Znq2 conducted at beamline P11. First results show dynamics of the electronic excitation on the timescale of a few hundred pico seconds up to a few nano seconds and provide a basic understanding for further research on those molecules. For Gaq3 this data is analyzed in detail and compared with visible fluorescence measurements suggesting at

  2. Time-resolved studies at PETRA III with a highly repetitive synchronized laser system

    International Nuclear Information System (INIS)

    Schlie, Mortiz

    2013-09-01

    Atomic and molecular processes can nowadays be directly followed in the time domain. This is a core technique for a better understanding of the involved fundamental physics, thus auguring new applications in the future as well. Usually the so-called pump-probe technique making use of two synchronized ultrashort light pulses is utilized to obtain this time-resolved data. In this work, the development and characterization of a synchronization system enabling such pump-probe studies at the storage ring PETRA III in combination with an external, then synchronized fs-laser system is described. The synchronization is based on an extended PLL approach with three interconnected feedback loops allowing to monitor short-time losses of the lock and thus prevent them. This way, the jitter between the laser PHAROS and the PETRA III reference signal is reduced to σ <5 ps. Thus the system allows to conduct experiments at a repetition rate of 130 kHz with a temporal resolution limited only by the X-ray pulse length. A major emphasis in the fundamental introductory chapters is an intuitive explanation of the basic principles of phase locked loops and the different aspects of phase noise to allow a deeper understanding of the synchronization. Furthermore, first pump-probe experiments conducted at different beamlines at PETRA III are presented, demonstrating the usability of the laser system in a scientific environment as well. In first characterizing experiments the pulse duration of PETRA III X-ray pulses has been measured to be 90 ps FWHM. In particular, there have been time resolved X-ray absorption spectroscopy experiments on Gaq3 and Znq2 conducted at beamline P11. First results show dynamics of the electronic excitation on the timescale of a few hundred pico seconds up to a few nano seconds and provide a basic understanding for further research on those molecules. For Gaq3 this data is analyzed in detail and compared with visible fluorescence measurements suggesting at least

  3. High resolution coherence domain depth-resolved nailfold capillaroscopy based on correlation mapping optical coherence tomography

    Science.gov (United States)

    Subhash, Hrebesh M.; O'Gorman, Sean; Neuhaus, Kai; Leahy, Martin

    2014-03-01

    In this paper we demonstrate a novel application of correlation mapping optical coherence tomography (cm-OCT) for volumetric nailfold capillaroscopy (NFC). NFC is a widely used non-invasive diagnostic method to analyze capillary morphology and microvascular abnormalities of nailfold area for a range of disease conditions. However, the conventional NFC is incapable of providing volumetric imaging, when volumetric quantitative microangiopathic parameters such as plexus morphology, capillary density, and morphologic anomalies of the end row loops most critical. cm-OCT is a recently developed well established coherence domain magnitude based angiographic modality, which takes advantage of the time-varying speckle effect, which is normally dominant in the vicinity of vascular regions compared to static tissue region. It utilizes the correlation coefficient as a direct measurement of decorrelation between two adjacent B-frames to enhance the visibility of depth-resolved microcirculation.

  4. Time-resolved Chemical Imaging of Molecules by High-order Harmonics and Ultrashort Rescattering Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chii Dong [Kansas State Univ., Manhattan, KS (United States)

    2016-03-21

    Directly monitoring atomic motion during a molecular transformation with atomic-scale spatio-temporal resolution is a frontier of ultrafast optical science and physical chemistry. Here we provide the foundation for a new imaging method, fixed-angle broadband laser-induced electron scattering, based on structural retrieval by direct one-dimensional Fourier transform of a photoelectron energy distribution observed along the polarization direction of an intense ultrafast light pulse. The approach exploits the scattering of a broadband wave packet created by strong-field tunnel ionization to self-interrogate the molecular structure with picometre spatial resolution and bond specificity. With its inherent femtosecond resolution, combining our technique with molecular alignment can, in principle, provide the basis for time-resolved tomography for multi-dimensional transient structural determination.

  5. Surface investigations using monolayer-resolvable high-resolution Rutherford backscattering spectroscopy

    International Nuclear Information System (INIS)

    Kimura, Kenji; Ohtsuka, Hisashi; Ohshima, Kazuomi; Mannami, Michi-hiko

    1994-01-01

    Energy spectra of scattered 0.5 MeV He ions from a clean (001) surface of SnTe are measured with a 90 sector magnetic spectrometer (ΔE/E ∼ 0.1%). The ions scattered from successive atomic layers can be resolved in the energy spectra. Inelastic energy losses and charge state distributions of 0.5 MeV He ions scattered from the topmost atomic layer of the SnTe(001) are measured. A position-dependent stopping power at the surface is proposed from the observed energy losses. The observed charge state distribution shows the importance of the charge-exchange processes with valence electrons in the tail of the electron distribution at the surface. (orig.)

  6. Turbulence modification in bubbly upward pipe flow. Extraction of time resolved turbulent microscopic structure by high speed PIV

    International Nuclear Information System (INIS)

    Yoshimura, Koki; Minato, Daiju; Sato, Yohei; Hishida, Koichi

    2004-01-01

    The objective of the present study is to obtain detailed information on the effects of bubbles on modification of turbulent structure by time-series measurements using a high speed time-resolved PIV. The experiments were carried out in a fully-developed vertical pipe with upflow of water at the Reynolds number of 9700 and the void fraction of 0.5%. It is observed that turbulence production was decreased and the dissipation rate was enhanced in the whole domain. We analyzed the effects of bubbles on modification of the energy cascade process from power spectra of velocity fluctuation of the continuous phase. (author)

  7. Time-resolved x-ray diffraction analysis of the experimental dehydration of serpentine at high pressure

    International Nuclear Information System (INIS)

    Inoue, Toru; Yoshimi, Isamu; Yamada, Akihiro; Kikegawa, Takumi

    2009-01-01

    Time-resolved, in situ X-ray diffraction analysis was used to determine the dehydration rate and kinetics of serpentine during experimental dehydration at high pressures. The capsule used comprises a diamond sleeve fitted with Au or Pt lids in order to provide high-quality, time-resolved X-ray diffraction data. Antigorite quickly dehydrated to enstatite + forsterite + fluid within 2 h at 650degC below ∼6 GPa. Avrami modeling of the results and SEM observations of the partially dehydrated sample revealed that the nucleation rate was quite high for enstatite but low for forsterite, showing incubation periods of ∼10 min before appearing. The crystallization of these minerals is controlled largely by the composition of the fluid generated from serpentine dehydration. The dehydration boundary determined below 6 GPa in the present study is consistent with the results of previous phase equilibrium studies. This study indicates that serpentine in a subducting slab dehydrates rapidly below 6 GPa when the slab intersects the dehydration boundary conditions. (author)

  8. Development of time-resolved optical measurement and diagnostic system for parameters of high current and pulsed electron beam

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Wang Yuan; Yang Guojun; Xia Liansheng; Li Hong; Zhang Zhuo; Liao Shuqing; Shi Jinshui

    2013-01-01

    The beam parameters measurement is the most important work for the study of linear induction accelerator(LIA). The beam parameters are important to evaluate the character of the beam. The demands of beam parameters measurement are improving while the development of accelerator is improving. The measurement difficulty feature higher time-resolved ability, higher spatial resolution, larger dynamic range and higher intuitionistic view data. The measurement technology of beam spot, beam emittance, beam energy have been developed for the past several years. Some high performance equipment such as high speed framing camera are developed recently. Under this condition, the relative integrated optical measurement and diagnostic system for the beam parameters is developed based on several principles. The system features time-resolved ability of up to 2 ns, high sensitivity and large dynamic range. The processing program is compiled for the data process and the local real-time process is reached. The measurement and diagnostic system has provided full and accurate data for the debug work and has been put into applications. (authors)

  9. The FAQUIRE Approach: FAst, QUantitative, hIghly Resolved and sEnsitivity Enhanced 1H, 13C Data.

    Science.gov (United States)

    Farjon, Jonathan; Milande, Clément; Martineau, Estelle; Akoka, Serge; Giraudeau, Patrick

    2018-02-06

    The targeted analysis of metabolites in complex mixtures is a challenging issue. NMR is one of the major tools in this field, but there is a strong need for more sensitive, better-resolved, and faster quantitative methods. In this framework, we introduce the concept of FAst, QUantitative, hIghly Resolved and sEnsitivity enhanced (FAQUIRE) NMR to push forward the limits of metabolite NMR analysis. 2D 1 H, 13 C 2D quantitative maps are promising alternatives for enhancing the spectral resolution but are highly time-consuming because of (i) the intrinsic nature of 2D, (ii) the longer recycling times required for quantitative conditions, and (iii) the higher number of scans needed to reduce the level of detection/quantification to access low concentrated metabolites. To reach this aim, speeding up the recently developed QUantItative Perfected and pUre shifted HSQC (QUIPU HSQC) is an interesting attempt to develop the FAQUIRE concept. Thanks to the combination of spectral aliasing, nonuniform sampling, and variable repetition time, the acquisition time of 2D quantitative maps is reduced by a factor 6 to 9, while conserving a high spectral resolution thanks to a pure shift approach. The analytical potential of the new Quick QUIPU HSQC (Q QUIPU HSQC) is evaluated on a model metabolite sample, and its potential is shown on breast-cell extracts embedding metabolites at millimolar to submillimolar concentrations.

  10. Fingerprinting ancient gold by measuring Pt with spatially resolved high energy Sy-XRF

    International Nuclear Information System (INIS)

    Guerra, M.F.; Calligaro, T.; Radtke, M.; Reiche, I.; Riesemeier, H.

    2005-01-01

    Trace elements of ancient gold such as Pt, give fundamental information on the circulation of the metal in the past. In the case of objects from the cultural heritage, the determination of trace elements requires non-destructive point analysis in general. These conditions and the need of good detection limits restrain the number of applicable analytical techniques. After the development of a PIXE set-up with a selective Cu or Zn filter of 75 μm and of a PIXE-XRF set-up using a primary target of As, we tested the possibilities of spatially resolved Sy-XRF to determine Pt in gold alloys. With a Zn filter, PIXE showed a detection limit of 1000 ppm in gold while PIXE-XRF lowers this detection limit down to 80 ppm. This last value being constrained by the resonant Raman effect produced on gold. In order to improve the detection limit of Pt keeping the non-destructiveness and access to point analysis, we developed an analytical protocol for XRF with synchrotron radiation at BESSY II, using the BAMline set-up. The L-lines of Pt were excited by a beam of energy above and below 11.564 keV and measured using a Si(Li) detector with a 50 μm Cu filter. A μ-beam of 100-250 μm 2 was used according to the size of the sample. The determination of the Pt content in the samples was carried out by Monte-Carlo simulation and subtraction of Au and Pt spectra obtained on pure standards. The limit of detection for Pt of 20 ppm was determined by using certified standards. The detection limits of a small set of other characteristic elements of gold were also measured using an incident energy of 33 keV

  11. Investigation of an IC Engine Intake Flow Based on Highly Resolved LES and PIV

    Directory of Open Access Journals (Sweden)

    Buhl Stefan

    2017-05-01

    Full Text Available To reduce emissions and fuel consumption, the current generation of gasoline engines uses technologies such as direct injection, downsizing and supercharging. All of them require a strong vortical in-cylinder charge motion, usually described as “tumble”, to improve fuel-air mixing and enhance flame propagation. The tumble development strongly depends on the flow field during the intake stroke. This flow field is dominated by the intake jet, which has to be captured well in the simulation. This work investigates the intake jet on a steady-state flow bench, especially in the vicinity of the intake valve. At first, the general flow dynamics of the intake jet for three different valve lifts and three different mass flows were investigated experimentally. For the smallest valve lift (3 mm, flow-field measurements using Particle Image Velocimetry (PIV show that the orientation of the intake jet significantly depends on the air flow rate, attaching to the pent roof for low flow rates. This phenomenon is less pronounced for higher valve lifts. An intermediate valve lift and flow rate were chosen for further investigations by scale-resolving simulations. Three different meshes (coarse, medium and fine and two turbulence models (Sigma and Detached Eddy Simulation-Shear Stress Transport (DES-SST are applied to consider their effect on the numerical results. An ad-hoc post-processing methodology based on the ensemble-averaged velocity field is presented capturing the jet centerline’s mean velocity and velocity fluctuations as well as its orientation, curvature and penetration depth. The simulation results are compared to each other as well as to measurements by PIV.

  12. DCS - A high flux beamline for time resolved dynamic compression science – Design highlights

    Energy Technology Data Exchange (ETDEWEB)

    Capatina, D., E-mail: capatina@aps.anl.gov; D’Amico, K., E-mail: kdamico@aps.anl.gov; Nudell, J., E-mail: jnudell@aps.anl.gov; Collins, J., E-mail: collins@aps.anl.gov; Schmidt, O., E-mail: oschmidt@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439 (United States)

    2016-07-27

    The Dynamic Compression Sector (DCS) beamline, a national user facility for time resolved dynamic compression science supported by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), has recently completed construction and is being commissioned at Sector 35 of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The beamline consists of a First Optics Enclosure (FOE) and four experimental enclosures. A Kirkpatrick–Baez focusing mirror system with 2.2 mrad incident angles in the FOE delivers pink beam to the experimental stations. A refocusing Kirkpatrick–Baez mirror system is situated in each of the two most downstream enclosures. Experiments can be conducted in either white, monochromatic, pink or monochromatic-reflected beam mode in any of the experimental stations by changing the position of two interlocked components in the FOE. The beamline Radiation Safety System (RSS) components have been designed to handle the continuous beam provided by two in-line revolver undulators with periods of 27 and 30 mm, at closed gap, 150 mA beam current, and passing through a power limiting aperture of 1.5 x 1.0 mm{sup 2}. A novel pink beam end station stop [1] is used to stop the continuous and focused pink beam which can achieve a peak heat flux of 105 kW/mm{sup 2}. A new millisecond shutter design [2] is used to deliver a quick pulse of beam to the sample, synchronized with the dynamic event, the microsecond shutter, and the storage ring clock.

  13. An Immersed Boundary - Adaptive Mesh Refinement solver (IB-AMR) for high fidelity fully resolved wind turbine simulations

    Science.gov (United States)

    Angelidis, Dionysios; Sotiropoulos, Fotis

    2015-11-01

    The geometrical details of wind turbines determine the structure of the turbulence in the near and far wake and should be taken in account when performing high fidelity calculations. Multi-resolution simulations coupled with an immersed boundary method constitutes a powerful framework for high-fidelity calculations past wind farms located over complex terrains. We develop a 3D Immersed-Boundary Adaptive Mesh Refinement flow solver (IB-AMR) which enables turbine-resolving LES of wind turbines. The idea of using a hybrid staggered/non-staggered grid layout adopted in the Curvilinear Immersed Boundary Method (CURVIB) has been successfully incorporated on unstructured meshes and the fractional step method has been employed. The overall performance and robustness of the second order accurate, parallel, unstructured solver is evaluated by comparing the numerical simulations against conforming grid calculations and experimental measurements of laminar and turbulent flows over complex geometries. We also present turbine-resolving multi-scale LES considering all the details affecting the induced flow field; including the geometry of the tower, the nacelle and especially the rotor blades of a wind tunnel scale turbine. This material is based upon work supported by the Department of Energy under Award Number DE-EE0005482 and the Sandia National Laboratories.

  14. High-resolution nuclear magnetic resonance measurements in inhomogeneous magnetic fields: A fast two-dimensional J-resolved experiment

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuqing; Cai, Shuhui; Yang, Yu; Sun, Huijun; Lin, Yanqin, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn; Chen, Zhong, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn [Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005 (China); Lin, Yung-Ya [Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095 (United States)

    2016-03-14

    High spectral resolution in nuclear magnetic resonance (NMR) is a prerequisite for achieving accurate information relevant to molecular structures and composition assignments. The continuous development of superconducting magnets guarantees strong and homogeneous static magnetic fields for satisfactory spectral resolution. However, there exist circumstances, such as measurements on biological tissues and heterogeneous chemical samples, where the field homogeneity is degraded and spectral line broadening seems inevitable. Here we propose an NMR method, named intermolecular zero-quantum coherence J-resolved spectroscopy (iZQC-JRES), to face the challenge of field inhomogeneity and obtain desired high-resolution two-dimensional J-resolved spectra with fast acquisition. Theoretical analyses for this method are given according to the intermolecular multiple-quantum coherence treatment. Experiments on (a) a simple chemical solution and (b) an aqueous solution of mixed metabolites under externally deshimmed fields, and on (c) a table grape sample with intrinsic field inhomogeneity from magnetic susceptibility variations demonstrate the feasibility and applicability of the iZQC-JRES method. The application of this method to inhomogeneous chemical and biological samples, maybe in vivo samples, appears promising.

  15. Measurements of spatially resolved high resolution spectra of laser-produced plasmas. FY 83 annual report

    International Nuclear Information System (INIS)

    Feldman, U.

    1984-01-01

    A high resolution grazing incidence spectrograph, provided by the Naval Research Laboratory and the Goddard Space Flight Center, has been installed on the Omega laser facility of the Laboratory for Laser Energetics (LLE) at the University of Rochester. This 3 meter instrument, with a 1200 lines/mm grating blazed at 2 0 35', has produced extremely high quality spectra in the wavelength region 10 A to 100 A. Spectra have been obtained from glass microballoon targets that are coated with a variety of high-Z materials. Transitions from the Na-like and Ne-like ionization stages of Fe, Ni, Cu, and Kr have been identified

  16. Carbon Condensation during High Explosive Detonation with Time Resolved Small Angle X-ray Scattering

    Science.gov (United States)

    Hammons, Joshua; Bagge-Hansen, Michael; Nielsen, Michael; Lauderbach, Lisa; Hodgin, Ralph; Bastea, Sorin; Fried, Larry; May, Chadd; Sinclair, Nicholas; Jensen, Brian; Gustavsen, Rick; Dattelbaum, Dana; Watkins, Erik; Firestone, Millicent; Ilavsky, Jan; van Buuren, Tony; Willey, Trevor; Lawrence Livermore National Lab Collaboration; Los Alamos National Laboratory Collaboration; Washington State University/Advanced Photon Source Team

    Carbon condensation during high-energy detonations occurs under extreme conditions and on very short time scales. Understanding and manipulating soot formation, particularly detonation nanodiamond, has attracted the attention of military, academic and industrial research. An in-situ characterization of these nanoscale phases, during detonation, is highly sought after and presents a formidable challenge even with today's instruments. Using the high flux available with synchrotron X-rays, pink beam small angle X-ray scattering is able to observe the carbon phases during detonation. This experimental approach, though powerful, requires careful consideration and support from other techniques, such as post-mortem TEM, EELS and USAXS. We present a comparative survey of carbon condensation from different CHNO high explosives. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

  17. Tunable All Reflective Spatial Heterodyne Spectroscopy, A Technique For High Resolving Power Observation OI Defused Emission Line Sources

    Science.gov (United States)

    Hosseini, Seyedeh Sona

    The solar system presents a challenge to spectroscopic observers, because it is an astrophysically low energy environment populated with often angularly extended targets (e.g, interplanetary medium, comets, planetary upper atmospheres, and planet and satellite near space environments). Spectroscopy is a proven tool for determining compositional and other properties of remote objects. Narrow band imaging and low resolving spectroscopic measurements provide information about composition, photochemical evolution, energy distribution and density. The extension to high resolving power provides further access to temperature, velocity, isotopic ratios, separation of blended sources, and opacity effects. The drawback of high-resolution spectroscopy comes from the instrumental limitations of lower throughput, the necessity of small entrance apertures, sensitivity, field of view, and large physical instrumental size. These limitations quickly become definitive for faint and/or extended targets and for spacecraft encounters. An emerging technique with promise for the study of faint, extended sources at high resolving power is the all-reflective form of the Spatial Heterodyne Spectrometer (SHS). SHS instruments are compact and naturally possess both high etendue and high resolving power. To achieve similar spectral grasp, grating spectrometers require big telescopes. SHS is a common-path beam Fourier transform interferometer that produces Fizeau fringe pattern for all other wavelengths except the tuned wavelength. Compared to similar Fourier transform Spectrometers (FTS), SHS has considerably relaxed optical tolerances that make it easier to use in the visible and UV spectral ranges. The large etendue of SHS instruments makes them ideal for observations of extended, low surface brightness, isolated emission line sources, while their intrinsically high spectral resolution enables the study of the dynamical and spectral characteristics described above. SHS also combines very

  18. Diffuse back-illumination setup for high temporally resolved extinction imaging

    DEFF Research Database (Denmark)

    Westlye, Fredrik Ree; Penney, Keith; Ivarsson, Anders

    2017-01-01

    -steering suppression. Methods for complete characterization of the optical system are detailed. Measurements of the liquid-vapor boundary and the soot volume fraction in an automotive spray are presented to demonstrate the resulting improved contrast and reduced uncertainty. The current optical setup reduces......This work presents the development of an optical setup for quantitative, high-temporal resolution line-of-sight extinction imaging in harsh optical environments. The application specifically targets measurements of automotive fuel sprays at high ambient temperature and pressure conditions where...

  19. Let's Resolve Conflicts Together: High School Classroom Activities. Conflict Management Week, May 1-7, 2000.

    Science.gov (United States)

    Ohio Commission on Dispute Resolution and Conflict Management, Columbus.

    The week of May 1-7, 2000 has been designated by the Governor of Ohio to be Conflict Management Week With heightened awareness to issues of school safety, it is important for high schools to take an active role in promoting constructive responses to conflict. Conflict is a natural and inevitable part of living, but managing conflict is difficult…

  20. High-intensity power-resolved radiation imaging of an operational nuclear reactor

    OpenAIRE

    Beaumont, Jonathan; Villa, Mario; Mellor, Matthew; Joyce, Malcolm John

    2015-01-01

    Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has bee...

  1. Advances in high repetition rate, ultra-short, gigawatt laser systems for time-resolved spectroscopy

    International Nuclear Information System (INIS)

    DiMauro, L.F.

    1991-01-01

    The objective of this article is to emphasize the current advances in the development of high-repetition rate amplifier pumps. Although this review highlights amplifier pump development, any recent data from achieved outputs via the tunable amplifier section is also discussed. The first section describes desirable parameters attributable to the pump amplifier while the rest of the article deals with specific examples for various options. The pump amplifiers can be characterized into two distinct classes; those achieving operation in the hundred hertz regime and those performing at repetition rates ≥1kHz. 23 refs., 4 figs

  2. High speed systems for time-resolved experiments with synchrotron radiation

    Science.gov (United States)

    Koziol, Anna; Maj, Piotr

    2018-02-01

    The UFXC32k is a single photon counting hybrid pixel detector with 75 μm pixel pitch. It was designed to cope with high X-ray intensities and therefore it is a very good candiate for synchrotron applications. In order to use this detector in an application, a dedicated setup must be designed and built allowing proper operation of the detector within the experiment. The paper presents two setups built for the purpose of Pump-Probe-Probe experiments at the Synchrotron SOLEIL and XPCS experiments at the APS.

  3. Comparative study of rare earth hexaborides using high resolution angle-resolved photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Ramankutty, S.V., E-mail: s.v.ramankutty@uva.nl [Van der Waals-Zeeman Institute, Institute of Physics (IoP), University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Jong, N. de; Huang, Y.K.; Zwartsenberg, B. [Van der Waals-Zeeman Institute, Institute of Physics (IoP), University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Massee, F. [Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Bay, T.V. [Van der Waals-Zeeman Institute, Institute of Physics (IoP), University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Golden, M.S., E-mail: m.s.golden@uva.nl [Van der Waals-Zeeman Institute, Institute of Physics (IoP), University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Frantzeskakis, E., E-mail: e.frantzeskakis@uva.nl [Van der Waals-Zeeman Institute, Institute of Physics (IoP), University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands)

    2016-04-15

    Highlights: • ARPES electronic structure study of rare-earth (RE) hexaborides SmB{sub 6}, CeB{sub 6} and YbB{sub 6}. • Increasing RE valence Yb[II], Sm[II/III], Ce[III] increases d-band occupancy. • YbB{sub 6} and SmB{sub 6} posses 2D states at E{sub F}, whereas the Fermi surface of CeB{sub 6} is 3D. • ARPES, LEED and STM data prove structural relaxation of the SmB{sub 6}(001) surface. - Abstract: Strong electron correlations in rare earth hexaborides can give rise to a variety of interesting phenomena like ferromagnetism, Kondo hybridization, mixed valence, superconductivity and possibly topological characteristics. The theoretical prediction of topological properties in SmB{sub 6} and YbB{sub 6} has rekindled the scientific interest in the rare earth hexaborides, and high-resolution ARPES has been playing a major role in the debate. The electronic band structure of the hexaborides contains the key to understand the origin of the different phenomena observed, and much can be learned by comparing the experimental data from different rare earth hexaborides. We have performed high-resolution ARPES on the (001) surfaces of YbB{sub 6}, CeB{sub 6} and SmB{sub 6}. On the most basic level, the data show that the differences in the valence of the rare earth element are reflected in the experimental electronic band structure primarily as a rigid shift of the energy position of the metal 5d states with respect to the Fermi level. Although the overall shape of the d-derived Fermi surface contours remains the same, we report differences in the dimensionality of these states between the compounds studied. Moreover, the spectroscopic fingerprint of the 4f states also reveals considerable differences that are related to their coherence and the strength of the d–f hybridization. For the SmB{sub 6} case, we use ARPES in combination with STM imaging and electron diffraction to reveal time dependent changes in the structural symmetry of the highly debated SmB{sub 6

  4. High Resolution Depth-Resolved Imaging From Multi-Focal Images for Medical Ultrasound

    DEFF Research Database (Denmark)

    Diamantis, Konstantinos; Dalgarno, Paul A.; Greenaway, Alan H.

    2015-01-01

    An ultrasound imaging technique providing subdiffraction limit axial resolution for point sources is proposed. It is based on simultaneously acquired multi-focal images of the same object, and on the image metric of sharpness. The sharpness is extracted by image data and presents higher values...... calibration curves combined with the use of a maximum-likelihood algorithm is then able to estimate, with high precision, the depth location of any emitter fron each single image. Estimated values are compared with the ground truth demonstrating that an accuracy of 28.6 µm (0.13λ) is achieved for a 4 mm depth...

  5. Resolving mass flux at high spatial and temporal resolution using GRACE intersatellite measurements

    DEFF Research Database (Denmark)

    Rowlands, D. D.; Luthcke, S. B.; Klosko, S. M.

    2005-01-01

    resolution. Using 4° × 4° blocks at 10-day intervals, we estimate the mass of surplus or deficit water over a 52° × 60° grid centered on the Amazon basin for July 2003. We demonstrate that the recovered signals are coherent and correlate well with the expected hydrological signal....... the estimation of static monthly parameters. Through an analysis of the GRACE data residuals, we show that the fundamental temporal and spatial resolution of the GRACE data is 10 days and 400 km. We present an approach similar in concept to altimetric methods that recovers submonthly mass flux at a high spatial...

  6. Highly efficient angularly resolving x-ray spectrometer optimized for absorption measurements with collimated sources

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Michal; Gonzalez, I.G.; Ekerfelt, H.; Svensson, J.B.; Hansson, M.; Wood, I. C.; Persson, A.; Mangles, S.P.D.; Lundh, O.; Falk, Kateřina

    2017-01-01

    Roč. 88, č. 6 (2017), s. 1-8, č. článku 063102. ISSN 0034-6748 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : acceleration * measurments * x ray * high energy Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.515, year: 2016

  7. Lifetime measurements of odd-parity high-excitation levels of Sn I by time-resolved laser spectroscopy

    International Nuclear Information System (INIS)

    Zhang, Wei; Feng, Yanyan; Xu, Jiaxin; Dai, Zhenwen; Palmeri, Patrick; Quinet, Pascal; Biemont, Emile

    2010-01-01

    Natural radiative lifetimes of 38 odd-parity highly excited levels in neutral tin in the energy range from 43 682.737 to 56 838.68 cm -1 have been measured by a time-resolved laser-induced fluorescence technique in an atomic beam produced by laser ablation on a solid tin sample. All the levels were excited from the metastable 3 P 1, 2 and 1 D 2 levels in the ground configuration. The second and third harmonics of a dye laser were adopted as the tunable exciting source (207-250 nm). The lifetime results obtained in this paper are in the range from 4.6 to 292 ns and will be useful in extending the set of oscillator strengths available in Sn I.

  8. Lifetime measurements of odd-parity high-excitation levels of Sn I by time-resolved laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei; Feng, Yanyan; Xu, Jiaxin; Dai, Zhenwen [College of Physics, Jilin University and Key Lab of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, Changchun 130021 (China); Palmeri, Patrick; Quinet, Pascal; Biemont, Emile, E-mail: dai@jlu.edu.c [Astrophysique et Spectroscopie, Universite de Mons-UMONS, B-7000 Mons (Belgium)

    2010-10-28

    Natural radiative lifetimes of 38 odd-parity highly excited levels in neutral tin in the energy range from 43 682.737 to 56 838.68 cm{sup -1} have been measured by a time-resolved laser-induced fluorescence technique in an atomic beam produced by laser ablation on a solid tin sample. All the levels were excited from the metastable {sup 3}P{sub 1,} {sub 2} and {sup 1}D{sub 2} levels in the ground configuration. The second and third harmonics of a dye laser were adopted as the tunable exciting source (207-250 nm). The lifetime results obtained in this paper are in the range from 4.6 to 292 ns and will be useful in extending the set of oscillator strengths available in Sn I.

  9. Application of a high-repetition-rate laser diagnostic system for single-cycle-resolved imaging in internal combustion engines.

    Science.gov (United States)

    Hult, Johan; Richter, Mattias; Nygren, Jenny; Aldén, Marcus; Hultqvist, Anders; Christensen, Magnus; Johansson, Bengt

    2002-08-20

    High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ignition, direct-injection stratified-charge, and homogeneous-charge compression-ignition engines. The recorded data reveal unique information on cycle-to-cycle variations in fuel transport and combustion. Moreover, the imaging system in combination with a scanning mirror is used to perform instantaneous three-dimensional fuel-concentration measurements.

  10. Time-resolved Thomson scattering on high-intensity laser-produced hot dense helium plasmas

    International Nuclear Information System (INIS)

    Sperling, P; Liseykina, T; Bauer, D; Redmer, R

    2013-01-01

    The introduction of brilliant free-electron lasers enables new pump–probe experiments to characterize warm and hot dense matter states, i.e. systems at solid-like densities and temperatures of one to several hundred eV. Such extreme conditions are relevant for high-energy density studies such as, e.g., in planetary physics and inertial confinement fusion. We consider here a liquid helium jet pumped with a high-intensity optical short-pulse laser that is subsequently probed with brilliant soft x-ray radiation. The optical short-pulse laser generates a strongly inhomogeneous helium plasma which is characterized with particle-in-cell simulations. We derive the respective Thomson scattering spectrum based on the Born–Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We observe plasmon modes that are generated in the interior of the target and study their temporal evolution. Such pump–probe experiments are promising tools to measure the important plasma parameters density and temperature. The method described here can be applied to various pump–probe scenarios by combining optical lasers, soft x-rays and hard x-ray sources. (paper)

  11. Electronic structure of ion arsenic high temperature superconductors studied by angle resolved photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The main purpose of the present thesis is to present our ARPES results on the iron arsenic superconductors. As revealed by a series of ARPES measurements on both the AEFe2As2 and the RFeAs(O,F) families (parent compound and carrier-doped systems), the electronic structures of the pnictides are complicated, three dimensional, and closely linked to their superconducting behavior (13; 14; 15; 16; 17; 18; 19). Parent compounds of these materials exhibit the basic hole-electron pocket dual plus an apparent Fermi surface reconstruction caused by long range antiferromagnetism (13; 15). When carriers are introduced, the chemical potential shifts in accordance with the Luttinger theorem and the rigid band shifting picture (13). Importantly, both the appearance and disappearance of the superconducting dome at low and high doping levels have intimate relation with topological changes at the Fermi surfaces, resulting in a specific Fermi topology being favored by superconductivity (15; 16). On the low doping side, superconductivity emerges in the phase diagram once the antiferromagnetic reconstruction disappears below the Fermi level, returning the Fermi surface to its paramagnetic-like appearance. On the high doping side, superconductivity disappears around a doping level at which the central hole pocket vanishes due to increasing electron concentration. Such phenomena are evidence for the governing role the electronic structure plays in their superconducting behavior.

  12. High temperature corrosion during biomass firing: improved understanding by depth resolved characterisation of corrosion products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2015-01-01

    changes within the near surface region (covering both the deposit and the steel surface). Such cross-section analysis was further complemented by plan view investigations (additionally involving X-ray diffraction) combined with removal of the corrosion products. Improved insights into the nature......The high temperature corrosion of an austenitic stainless steel (TP 347H FG), widely utilised as a superheater tube material in Danish power stations, was investigated to verify the corrosion mechanisms related to biomass firing. KCl coated samples were exposed isothermally to 560 degrees C...... of the corrosion products as a function of distance from the deposit surface were revealed through this comprehensive characterisation. Corrosion attack during simulated straw-firing conditions was observed to occur through both active oxidation and sulphidation mechanisms....

  13. Tunable optical setup with high flexibility for spectrally resolved coherent anti-Stokes Raman scattering microscopy

    International Nuclear Information System (INIS)

    Bergner, G; Akimov, D; Bartelt, H; Dietzek, B; Popp, J; Schlücker, S

    2011-01-01

    A simplified setup for coherent anti-Stokes Raman scattering (CARS) microscopy is introduced, which allows for recording CARS images with 30 cm -1 excitation bandwidth for probing Raman bands between 500 and 900 cm -1 with minimal requirements for alignment. The experimental arrangement is based on electronic switching between CARS images recorded at different Raman resonances by combining a photonic crystal fiber (PCF) as broadband light source and an acousto-optical programmable dispersive filter (AOPDF) as tunable wavelength filter. Such spatial light modulator enables selection of a narrow-band spectrum to yield high vibrational contrast and hence chemical contrast in the resultant CARS images. Furthermore, an experimental approach to reconstruct spectral information from CARS image contrast is introduced

  14. Highly sensitive time resolved singlet oxygen luminescence detection using LEDs as the excitation source

    International Nuclear Information System (INIS)

    Hackbarth, S; Schlothauer, J; Preuss, A; Röder, B

    2013-01-01

    For the first time singlet oxygen luminescence kinetics in living cells were detected at high precision using LED light for excitation. As LED technology evolves, the light intensity emitted by standard LEDs allows photosensitized singlet oxygen luminescence detection in solution and cell suspensions. We present measurements superior to those of most actual laser powered setups regarding precision of singlet oxygen kinetics in solutions and cell suspensions. Data presented here show that LED based setups allow the determination of the photosensitizer triplet and singlet oxygen decay times in vitro with an accuracy of 0.1 μs. This enables monitoring of the photosensitizer efficiency and interaction with the cellular components using illumination doses small enough not to cause cell death. (letter)

  15. Chandra Phase-resolved Spectroscopy of the High Magnetic Field Pulsar B1509−58

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chin-Ping; Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Takata, J. [School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei (China); Shannon, R. M. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Johnston, S., E-mail: cphu@hku.hk, E-mail: ncy@bohr.physics.hku.hk [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Box 76, Epping, NSW 1710 (Australia)

    2017-04-01

    We report on a timing and spectral analysis of the young, high magnetic field rotation-powered pulsar (RPP) B1509−58 using Chandra continuous-clocking mode observation. The pulsar’s X-ray light curve can be fit by the two Gaussian components and the pulsed fraction shows moderate energy dependence over the Chandra band. The pulsed X-ray spectrum is well described by a power law with a photon index 1.16(4), which is harder than the values measured with RXTE /PCA and NuSTAR . This result supports the log-parabolic model for the broadband X-ray spectrum. With the unprecedented angular resolution of Chandra , we clearly identified off-pulse X-ray emission from the pulsar, and its spectrum is best fit by a power law plus blackbody model. The latter component has a temperature of ∼0.14 keV with a bolometric luminosity comparable to the luminosities of other young and high magnetic field RPPs, and it lies between the temperature of magnetars and typical RPPs. In addition, we found that the nonthermal X-ray emission of PSR B1509−58 is significantly softer in the off-pulse phase than in the pulsed phase, with the photon index varying between 1.0 and 1.8 and anticorrelated with the flux. This is similar to the behavior of three other young pulsars. We interpreted it as different contributions of pair-creation processes at different altitudes from the neutron star surface according to the outer-gap model.

  16. Bulk electronic state of high-Tc cuprate La2-xSrxCuO4 observed by high-energy angle integrated and resolved photoemission spectroscopy

    International Nuclear Information System (INIS)

    Kasai, S.; Sekiyama, A.; Tsunekawa, M.; Ernst, P.T.; Shigemoto, A.; Yamasaki, A.; Irizawa, A.; Imada, S.; Sing, M.; Muro, T.; Sasagawa, T.; Takagi, H.; Suga, S.

    2005-01-01

    The high-energy core-level photoemission spectroscopy (PES) and angle-resolved photoemission spectroscopy (ARPES) measurements have been performed for La 2-x Sr x CuO 4 (LSCO). Polar-angle dependence of the Cu 2p core-level PES has revealed a discrepancy between bulk and surface. We have observed by the high-energy ARPES that the Fermi surface of LSCO with x=0.16 is electron-like, in contrast to previous low-energy ARPES results

  17. Application of spatially resolved high resolution crystal spectrometry to inertial confinement fusion plasmas.

    Science.gov (United States)

    Hill, K W; Bitter, M; Delgado-Aparacio, L; Pablant, N A; Beiersdorfer, P; Schneider, M; Widmann, K; Sanchez del Rio, M; Zhang, L

    2012-10-01

    High resolution (λ∕Δλ ∼ 10 000) 1D imaging x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as inertial confinement fusion plasmas and targets on x-ray light source beam lines, with spatial resolution of micrometers, as demonstrated by laboratory experiments using a 250-μm (55)Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10(-8)-10(-6) times source x-rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to the National Ignition Facility (NIF), and predictions of performance on NIF will be presented.

  18. Spatially resolved analysis and minimization of resistive losses in high-efficiency Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Altermatt, P.P.; Wang, A.; Zhao, J.; Robinson, S.J.; Bowden, S.; Green, M.A. [New South Wales Univ., Kensington, NSW (Australia). Centre for Photovoltaic Devices and Systems; Heiser, G. [New South Wales Univ., Sydney, NSW (Australia). School of Computer Science and Engineering; Aberle, A.G. [Institut fuer Solarenergieforschung (ISFH), Emmerthal (Germany)

    1996-11-01

    This paper presents an improved method for measuring the total lumped series resistance (R{sub s}) of high-efficiency solar cells. Since this method greatly minimizes the influence of non-linear recombination processes on the measured R{sub s} values, it is possible to determine R{sub s} as a function of external current density over a wide range of illumination levels with a significantly improved level of accuracy. This paper furthermore explains how resistive losses in the emitter, the base, the metal/silicon contacts and the front metal grid can be separately determined by combining measurements and multi-dimensional numerical simulations. A novel combination of device simulation and circuit simulation is introduced in order to simulate complete 2 x 2 cm s sq. P:ERL (`passivated emitter and rear locally-diffused`) silicon solar cells. These computer simulations provide improved insight into the dynamics of resistive losses, and thus allow new strategies for the optimization of resistive losses to be developed. The predictions have been experimentally verified with PERL cells, whose resistive losses were reduced to approximately half of their previous values, contributing to a new efficiency world record (24.0%) for silicon solar cells under terrestrial illumination. The measurement techniques and optimization strategies presented here can be applied to most other types of solar cells, and to materials other than silicon. (Author)

  19. Excess glycogen does not resolve high ultimate pH of oxidative muscle.

    Science.gov (United States)

    England, Eric M; Matarneh, Sulaiman K; Oliver, Emily M; Apaoblaza, Ariel; Scheffler, Tracy L; Shi, Hao; Gerrard, David E

    2016-04-01

    Skeletal muscle glycogen content can impact the extent of postmortem pH decline. Compared to glycolytic muscles, oxidative muscles contain lower glycogen levels antemortem which may contribute to the higher ultimate pH. In an effort to explore further the participation of glycogen in postmortem metabolism, we postulated that increasing the availability of glycogen would drive additional pH decline in oxidative muscles to equivalent pH values similar to the ultimate pH of glycolytic muscles. Glycolysis and pH declines were compared in porcine longissimus lumborum (glycolytic) and masseter (oxidative) muscles using an in vitro system in the presence of excess glycogen. The ultimate pH of the system containing longissimus lumborum reached a value similar to that observed in intact muscle. The pH decline of the system containing masseter samples stopped prematurely resulting in a higher ultimate pH which was similar to that of intact masseter muscle. To investigate further, we titrated powdered longissimus lumborum and masseter samples in the reaction buffer. As the percentage of glycolytic sample increased, the ultimate pH decreased. These data show that oxidative muscle produces meat with a high ultimate pH regardless of glycogen content and suggest that inherent muscle factors associated with glycolytic muscle control the extent of pH decline in pig muscles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. HIRS-AMTS satellite sounding system test - Theoretical and empirical vertical resolving power. [High resolution Infrared Radiation Sounder - Advanced Moisture and Temperature Sounder

    Science.gov (United States)

    Thompson, O. E.

    1982-01-01

    The present investigation is concerned with the vertical resolving power of satellite-borne temperature sounding instruments. Information is presented on the capabilities of the High Resolution Infrared Radiation Sounder (HIRS) and a proposed sounding instrument called the Advanced Moisture and Temperature Sounder (AMTS). Two quite different methods for assessing the vertical resolving power of satellite sounders are discussed. The first is the theoretical method of Conrath (1972) which was patterned after the work of Backus and Gilbert (1968) The Backus-Gilbert-Conrath (BGC) approach includes a formalism for deriving a retrieval algorithm for optimizing the vertical resolving power. However, a retrieval algorithm constructed in the BGC optimal fashion is not necessarily optimal as far as actual temperature retrievals are concerned. Thus, an independent criterion for vertical resolving power is discussed. The criterion is based on actual retrievals of signal structure in the temperature field.

  1. Highly resolved early Eocene food webs show development of modern trophic structure after the end-Cretaceous extinction.

    Science.gov (United States)

    Dunne, Jennifer A; Labandeira, Conrad C; Williams, Richard J

    2014-05-07

    Generalities of food web structure have been identified for extant ecosystems. However, the trophic organization of ancient ecosystems is unresolved, as prior studies of fossil webs have been limited by low-resolution, high-uncertainty data. We compiled highly resolved, well-documented feeding interaction data for 700 taxa from the 48 million-year-old latest early Eocene Messel Shale, which contains a species assemblage that developed after an interval of protracted environmental and biotal change during and following the end-Cretaceous extinction. We compared the network structure of Messel lake and forest food webs to extant webs using analyses that account for scale dependence of structure with diversity and complexity. The Messel lake web, with 94 taxa, displays unambiguous similarities in structure to extant webs. While the Messel forest web, with 630 taxa, displays differences compared to extant webs, they appear to result from high diversity and resolution of insect-plant interactions, rather than substantive differences in structure. The evidence presented here suggests that modern trophic organization developed along with the modern Messel biota during an 18 Myr interval of dramatic post-extinction change. Our study also has methodological implications, as the Messel forest web analysis highlights limitations of current food web data and models.

  2. An ultra-high vacuum scanning tunneling microscope operating at sub-Kelvin temperatures and high magnetic fields for spin-resolved measurements

    Science.gov (United States)

    Salazar, C.; Baumann, D.; Hänke, T.; Scheffler, M.; Kühne, T.; Kaiser, M.; Voigtländer, R.; Lindackers, D.; Büchner, B.; Hess, C.

    2018-06-01

    We present the construction and performance of an ultra-low-temperature scanning tunneling microscope (STM), working in ultra-high vacuum (UHV) conditions and in high magnetic fields up to 9 T. The cryogenic environment of the STM is generated by a single-shot 3He magnet cryostat in combination with a 4He dewar system. At a base temperature (300 mK), the cryostat has an operation time of approximately 80 h. The special design of the microscope allows the transfer of the STM head from the cryostat to a UHV chamber system, where samples and STM tips can be easily exchanged. The UHV chambers are equipped with specific surface science treatment tools for the functionalization of samples and tips, including high-temperature treatments and thin film deposition. This, in particular, enables spin-resolved tunneling measurements. We present test measurements using well-known samples and tips based on superconductors and metallic materials such as LiFeAs, Nb, Fe, and W. The measurements demonstrate the outstanding performance of the STM with high spatial and energy resolution as well as the spin-resolved capability.

  3. Time and space resolved spectroscopic investigation during anode plume formation in a high-current vacuum arc

    Science.gov (United States)

    Khakpour, A.; Methling, R.; Uhrlandt, D.; Franke, St.; Gortschakow, S.; Popov, S.; Batrakov, A.; Weltmann, K. D.

    2017-05-01

    This paper presents time and space resolved results of spectroscopic measurements during the formation of an anode plume in the late current pulse phase of a high-current vacuum arc. The formation of the anode plume is investigated systematically based on the occurrence of high-current anode spots, depending on gap distance and current for AC 100 Hz and CuCr7525 butt contacts with a diameter of 10 mm. The anode plume is observed after the extinction of anode spot type 2 in which both the anode and cathode are active. It is concluded from the spatial profiles of the atomic and ionic radiation, parallel and perpendicular to anode surface, that the inner part of the plume is dominated by Cu I radiation, whereas a halo of light emitted by Cu II covers the plume. The radiation intensity of Cu III lines is quite low across the whole anode plume. Upper level excited state densities corresponding to Cu I lines at 510.55, 515.32, 521.82, 578.21 nm are determined. The temporal evolution of the resulting excitation temperature in the centre of the plume varies from 8500 K to 6000 K at 500 µs to 100 µs before current zero, respectively. The density calculated for Cu I at position in the plume is in the range of 1-5  ×  1019 m-3.

  4. Instruments and techniques for analysing the time-resolved transverse phase space distribution of high-brightness electron beams

    International Nuclear Information System (INIS)

    Rudolph, Jeniffa

    2012-01-01

    This thesis deals with the instruments and techniques used to characterise the transverse phase space distribution of high-brightness electron beams. In particular, methods are considered allowing to measure the emittance as a function of the longitudinal coordinate within the bunch (slice emittance) with a resolution in the ps to sub-ps range. The main objective of this work is the analysis of techniques applicable for the time-resolved phase space characterisation for future high-brightness electron beam sources and single-pass accelerators based on these. The competence built up by understanding and comparing different techniques is to be used for the design and operation of slice diagnostic systems for the Berlin Energy Recovery Linac Project (BERLinPro). In the framework of the thesis, two methods applicable for slice emittance measurements are considered, namely the zero-phasing technique and the use of a transverse deflector. These methods combine the conventional quadrupole scan technique with a transfer of the longitudinal distribution into a transverse distribution. Measurements were performed within different collaborative projects. The experimental setup, the measurement itself and the data analysis are discussed as well as measurement results and simulations. In addition, the phase space tomography technique is introduced. In contrast to quadrupole scan-based techniques, tomography is model-independent and can reconstruct the phase space distribution from simple projected measurements. The developed image reconstruction routine based on the Maximum Entropy algorithm is introduced. The quality of the reconstruction is tested using different model distributions, simulated data and measurement data. The results of the tests are presented. The adequacy of the investigated techniques, the experimental procedures as well as the developed data analysis tools could be verified. The experimental and practical experience gathered during this work, the

  5. Small Sub-micron-Particle Position-Resolving Laser-Doppler Velocimeter for High-Speed Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The technical objectives of this proposed work are to develop and prove the use of LDV and CompLDV for particle-position-resolving and flow velocity profile...

  6. High-resolution time-resolved Experiments on mixing and entrainment of buoyant jets in stratified environments

    Energy Technology Data Exchange (ETDEWEB)

    Manera, Annalisa; Bardet, Philippe; Petrov, Victor

    2018-03-29

    scales, which leads to anisotropy. This important physical phenomenon is highly three dimensional and is challenging to capture even with high-fidelity CFD simulations, due in part to lack of sufficiently resolved validation data. Furthermore, the experimental data available in the open literature do not feature the level of fidelity needed for an extensive validation of turbulence models in lower order CFD. To shed new lights into the crucial phenomena object of the present research project, it was proposed to conduct coordinated experiments and simulations at the University of Michigan and the George Washington University. The project has resulted in an experimental database of high-resolution time-resolved measurements of jets in uniform and stratified environments. The novel experimental data will be used to validate computational fluid dynamic (CFD) codes, including both Large Eddy Simulations (LES) and unsteady Reynolds-averaged Navier-Stokes equations (URANS) methodologies. In the Experimental and Multiphase flow (ECMF) laboratory at Univerisity of Michigan, we built two experimental facilities to investigate also the effect of scaling. The first facility, DESTROJER (DEnsity Stratified Turbulent ROund free Jet ExpeRiment), featuring a contoured jet nozzle with a diameter of D=12.7mm and a 1m×1m×1m cubic tank, which is made of acrylic glass for optical access. The ratio between the tank width and the nozzle diameter is equal to 78, which ensures that there is no direct interaction between the jet and the side walls. A second, modular experimental facility, features three different tank sizes of size 10×10×30, 20×20×30, 30×30×30 cm3 respectively (all tanks have the same height of 30 cm), and a jet diameter of 2mm. For the modular facility, tank-to-nozzle ratio of 50, 100, and 150 are obtained respectively. Experiments with different-density jet impactions and sharp interface with a density difference of 3.16% In the Laboratory at George Washington University

  7. High resolution time- and 2-dimensional space-resolved x-ray imaging of plasmas at NOVA

    International Nuclear Information System (INIS)

    Landen, O.L.

    1992-01-01

    A streaked multiple pinhole camera technique, first used by P. Choi et al. to record time- and 2-D space-resolved soft X-ray images of plasma pinches, has been implemented on laser plasmas at NOVA. The instrument is particularly useful for time-resolved imaging of small sources ( 2.5 key imaging, complementing the existing 1--3 key streaked X-ray microscope capabilities at NOVA

  8. Time-resolved optical spectrometer based on a monolithic array of high-precision TDCs and SPADs

    Science.gov (United States)

    Tamborini, Davide; Markovic, Bojan; Di Sieno, Laura; Contini, Davide; Bassi, Andrea; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2013-12-01

    We present a compact time-resolved spectrometer suitable for optical spectroscopy from 400 nm to 1 μm wavelengths. The detector consists of a monolithic array of 16 high-precision Time-to-Digital Converters (TDC) and Single-Photon Avalanche Diodes (SPAD). The instrument has 10 ps resolution and reaches 70 ps (FWHM) timing precision over a 160 ns full-scale range with a Differential Non-Linearity (DNL) better than 1.5 % LSB. The core of the spectrometer is the application-specific integrated chip composed of 16 pixels with 250 μm pitch, containing a 20 μm diameter SPAD and an independent TDC each, fabricated in a 0.35 μm CMOS technology. In front of this array a monochromator is used to focus different wavelengths into different pixels. The spectrometer has been used for fluorescence lifetime spectroscopy: 5 nm spectral resolution over an 80 nm bandwidth is achieved. Lifetime spectroscopy of Nile blue is demonstrated.

  9. Fully digital routing logic for single-photon avalanche diode arrays in highly efficient time-resolved imaging

    Science.gov (United States)

    Cominelli, Alessandro; Acconcia, Giulia; Ghioni, Massimo; Rech, Ivan

    2018-03-01

    Time-correlated single-photon counting (TCSPC) is a powerful optical technique, which permits recording fast luminous signals with picosecond precision. Unfortunately, given its repetitive nature, TCSPC is recognized as a relatively slow technique, especially when a large time-resolved image has to be recorded. In recent years, there has been a fast trend toward the development of TCPSC imagers. Unfortunately, present systems still suffer from a trade-off between number of channels and performance. Even worse, the overall measurement speed is still limited well below the saturation of the transfer bandwidth toward the external processor. We present a routing algorithm that enables a smart connection between a 32×32 detector array and five shared high-performance converters able to provide an overall conversion rate up to 10 Gbit/s. The proposed solution exploits a fully digital logic circuit distributed in a tree structure to limit the number and length of interconnections, which is a major issue in densely integrated circuits. The behavior of the logic has been validated by means of a field-programmable gate array, while a fully integrated prototype has been designed in 180-nm technology and analyzed by means of postlayout simulations.

  10. Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer

    Science.gov (United States)

    Gotlieb, K.; Hussain, Z.; Bostwick, A.; Lanzara, A.; Jozwiak, C.

    2013-09-01

    A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-EF spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

  11. An Angle Resolved Photoemission Study of a Mott Insulator and Its Evolution to a High Temperature Superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Ronning, Filip

    2002-03-19

    One of the most remarkable facts about the high temperature superconductors is their close proximity to an antiferromagnetically ordered Mott insulating phase. This fact suggests that to understand superconductivity in the cuprates we must first understand the insulating regime. Due to material properties the technique of angle resolved photoemission is ideally suited to study the electronic structure in the cuprates. Thus, a natural starting place to unlocking the secrets of high Tc would appears to be with a photoemission investigation of insulating cuprates. This dissertation presents the results of precisely such a study. In particular, we have focused on the compound Ca{sub 2-x}Na{sub x}CuO{sub 2}Cl{sub 2}. With increasing Na content this system goes from an antiferromagnetic Mott insulator with a Neel transition of 256K to a superconductor with an optimal transition temperature of 28K. At half filling we have found an asymmetry in the integrated spectral weight, which can be related to the occupation probability, n(k). This has led us to identify a d-wave-like dispersion in the insulator, which in turn implies that the high energy pseudogap as seen by photoemission is a remnant property of the insulator. These results are robust features of the insulator which we found in many different compounds and experimental conditions. By adding Na we were able to study the evolution of the electronic structure across the insulator to metal transition. We found that the chemical potential shifts as holes are doped into the system. This picture is in sharp contrast to the case of La{sub 2-x}Sr{sub x}CuO{sub 4} where the chemical potential remains fixed and states are created inside the gap. Furthermore, the low energy excitations (ie the Fermi surface) in metallic Ca{sub 1.9}Na{sub 0.1}CuO{sub 2}Cl{sub 2} is most well described as a Fermi arc, although the high binding energy features reveal the presence of shadow bands. Thus, the results in this dissertation provide a

  12. Full genotyping of a highly polymorphic human gene trait by time-resolved fluorescence resonance energy transfer.

    Directory of Open Access Journals (Sweden)

    Edoardo Totè

    Full Text Available The ability of detecting the subtle variations occurring, among different individuals, within specific DNA sequences encompassed in highly polymorphic genes discloses new applications in genomics and diagnostics. DQB1 is a gene of the HLA-II DQ locus of the Human Leukocyte Antigens (HLA system. The polymorphisms of the trait of the DQB1 gene including codons 52-57 modulate the susceptibility to a number of severe pathologies. Moreover, the donor-receiver tissue compatibility in bone marrow transplantations is routinely assessed through crossed genotyping of DQB and DQA. For the above reasons, the development of rapid, reliable and cost-effective typing technologies of DQB1 in general, and more specifically of the codons 52-57, is a relevant although challenging task. Quantitative assessment of the fluorescence resonance energy transfer (FRET efficiency between chromophores labelling the opposite ends of gene-specific oligonucleotide probes has proven to be a powerful tool to type DNA polymorphisms with single-nucleotide resolution. The FRET efficiency can be most conveniently quantified by applying a time-resolved fluorescence analysis methodology, i.e. time-correlated single-photon counting, which allows working on very diluted template specimens and in the presence of fluorescent contaminants. Here we present a full in-vitro characterization of the fluorescence responses of two probes when hybridized to oligonucleotide mixtures mimicking all the possible genotypes of the codons 52-57 trait of DQB1 (8 homozygous and 28 heterozygous. We show that each genotype can be effectively tagged by the combination of the fluorescence decay constants extrapolated from the data obtained with such probes.

  13. A universal high energy anomaly in angle resolved photoemission spectra of high temperature superconductors -- possible evidence of spinon and holon branches

    International Nuclear Information System (INIS)

    Graf, J.; Gweon, G.-H.; McElroy, K.; Zhou, S.Y.; Jozwiak, C.; Rotenberg, E.; Bill, A.; Sasagawa, T.; Eisaki, H.; Uchida, S.; Takagi, H.; Lee, D.-H.; Lanzara, A.

    2006-01-01

    A universal high energy anomaly in the single particle spectral function is reported in three different families of high temperature superconductors by using angle-resolved photoemission spectroscopy. As we follow the dispersing peak of the spectral function from the Fermi energy to the valence band complex, we find dispersion anomalies marked by two distinctive high energy scales, E 1 approx 0.38eV and E 2 approx 0.8 eV. E 1 marks the energy above which the dispersion splits into two branches. One is a continuation of the near parabolic dispersion, albeit with reduced spectral weight, and reaches the bottom of the band at the Gamma point at approx 0.5 eV. The other is given by a peak in the momentum space, nearly independent of energy between E 1 and E 2 . Above E 2 , a band-like dispersion re-emerges. We conjecture that these two energies mark the disintegration of the low energy quasiparticles into a spinon and holon branch in the high T c cuprates

  14. Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

    Science.gov (United States)

    Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

    2015-02-03

    The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions.

  15. Development and application of methods and models for the calculation of spatially and temporally highly resolved emissions in Europe

    International Nuclear Information System (INIS)

    Thiruchittampalam, Balendra

    2014-01-01

    High spatial and temporal resolution models are essential for answering many questions of air quality management and climate modeling. High-resolution emission models are required to determine the concentration of pollutants using chemical transport models, and to quantify the impacts on health and environment and in particular to develop adequate countermeasures. The aim of this work is to develop methods for the calculation of spatially and temporally high-resolved emissions and to apply these exemplarily on a 1 km x 1 km and hourly resolution for the year 2008 in the EU-27 and EFTA countries. The derivation of methods for the spatial and temporal resolution of emissions with corresponding detailed equations is one of the major improvements that have been carried out in the course of this work. The improvement of the spatial distribution of emissions from the point source relevant sectors like energy supply, industry and waste management is achieved by considering sector specific diffuse emission shares. The progress of the spatial distribution of emissions from households is in particular the development of a fuel type weighted distribution over Europe. Another main focus is the development of the spatial distribution of road transport emissions. Due to the restricted access to traffic count data at the European level, methods have been established to provide reliable emissions on grid level for Europe. The progress in the spatial distribution of agricultural emissions is achieved by the consideration of diffuse shares similar to the other point source relevant sectors like energy supply or industry. In addition to the spatial distribution of the emissions the temporal resolution is a main focus of this work, since the state of knowledge of the temporal resolution of emissions in Europe is still rudimentary. Therefore, it was necessary to develop in particular time curves for the hourly resolution of emissions for the main sectors, namely electricity and heat

  16. System for time-resolved laser absorption spectroscopy and its application to high-power impulse magnetron sputtering

    Czech Academy of Sciences Publication Activity Database

    Adámek, Petr; Olejníček, Jiří; Hubička, Zdeněk; Čada, Martin; Kment, Štěpán; Kohout, Michal; Do, H.T.

    2017-01-01

    Roč. 88, č. 2 (2017), 1-8, č. článku 023105. ISSN 0034-6748 R&D Projects: GA TA ČR(CZ) TF01000084; GA ČR(CZ) GA15-00863S Institutional support: RVO:68378271 Keywords : plasma diagnostics * HiPIMS * time resolved measurement * laser absorption spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.515, year: 2016

  17. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Directory of Open Access Journals (Sweden)

    W. Hu

    2017-08-01

    . It was indicated by the good correlations (r = 0.53–0.75, p < 0.01 between LO-OOA and odd oxygen (Ox =  O3 + NO2, and between MO-OOA and liquid water content in aerosols. BBOA was resolved in spring and autumn, influenced by agricultural biomass burning (e.g., field preparation burnings, straw burning after the harvest. CCOA was only identified in winter due to domestic heating. These results signified that the comprehensive management for biomass burning and coal combustion emissions is needed. High concentrations of chemical components in PM1 in Beijing, especially in winter or in adverse meteorological conditions, suggest that further strengthening the regional emission control of primary particulate and precursors of secondary species is expected.

  18. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Science.gov (United States)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Zheng, Jing; Chen, Chen; Wu, Yusheng; Guo, Song

    2017-08-01

    (r = 0.53-0.75, p < 0.01) between LO-OOA and odd oxygen (Ox = O3 + NO2), and between MO-OOA and liquid water content in aerosols. BBOA was resolved in spring and autumn, influenced by agricultural biomass burning (e.g., field preparation burnings, straw burning after the harvest). CCOA was only identified in winter due to domestic heating. These results signified that the comprehensive management for biomass burning and coal combustion emissions is needed. High concentrations of chemical components in PM1 in Beijing, especially in winter or in adverse meteorological conditions, suggest that further strengthening the regional emission control of primary particulate and precursors of secondary species is expected.

  19. Tunable Reflective Spatial Heterodyne Spectrometer: A Technique for High Resolving Power, Wide Field Of View Observation Of Diffuse Emission Line Sources

    Science.gov (United States)

    Hosseini, Seyedeh Sona

    The purpose of this dissertation is to discuss the need for new technology in broadband high-resolution spectroscopy based on the emerging technique of Spatial Heterodyne Spectroscopy (SHS) and to propose new solutions that should enhance and generalize this technology to other fields. Spectroscopy is a proven tool for determining compositional and other properties of remote objects. Narrow band imaging and low resolving spectroscopic measurements provide information about composition, photochemical evolution, energy distribution and density. The extension to high resolving power provides further access to temperature, velocity, isotopic ratios, separation of blended sources, and opacity effects. In current high resolving power devices, the drawback of high-resolution spectroscopy is bound to the instrumental limitations of lower throughput, the necessity of small entrance apertures, sensitivity, field of view, and large physical instrumental size. These limitations quickly become handicapping for observation of faint and/or extended targets and for spacecraft encounters. A technique with promise for the study of faint and extended sources at high resolving power is the reflective format of the Spatial Heterodyne Spectrometer (SHS). SHS instruments are compact and naturally tailored for both high etendue (defined in section 2.2.5) and high resolving power. In contrast, to achieve similar spectral grasp, grating spectrometers require large telescopes. For reference, SHS is a cyclical interferometer that produces Fizeau fringe pattern for all other wavelengths except the tuned wavelength. The large etendue obtained by SHS instruments makes them ideal for observations of extended, low surface brightness, isolated emission line sources, while their intrinsically high spectral resolution enables one to study the dynamical and physical properties described above. This document contains four chapters. Chapter 1, introduces a class of scientific targets that formerly have

  20. A high-temperature furnace and a heating/drawing device designed for time-resolved X-ray diffraction measurements of polymer solids using imaging plates

    International Nuclear Information System (INIS)

    Murakami, Syozo; Tanno, Kiyomitsu; Tsuji, Masaki; Kohjiya, Shinzo

    1995-01-01

    For time-resolved X-ray diffraction measurements using the imaging plate system in the drawing and/or heating process of polymer solids, a high-temperature furnace for heat treatment and a heating/drawing device were newly designed and constructed. Then, to demonstrate their performance, some experimental results obtained in the drawing process of an extruded/blown film of high-density polyethylene at room temperature and in the crystallization process of an oriented amorphous film of poly(ethylene naphthalene-2,6-dicarboxylate) by heating were presented. Other experimental results obtained using them were also briefly cited. (author)

  1. Time-resolved x-ray diffraction measurement of C{sub 60} under high pressure and temperature using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Horikawa, T [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Suito, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Kobayashi, M [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Onodera, A [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

    2002-11-11

    C{sub 60} has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C{sub 60} structure are presented and the relevance to the hardness of materials derived from C{sub 60} is discussed.

  2. Investigating mechanically induced phase response of the tissue by using high-speed phase-resolved optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Ling, Yuye; Hendon, Christine P.

    2017-02-01

    Phase-resolved optical coherence tomography (OCT), a functional extension of OCT, provides depth-resolved phase information with extra contrast. In cardiology, changes in the mechanical properties have been associated with tissue remodeling and disease progression. Here we present the capability of profiling structural deformation of the sample in vivo by using a highly stable swept source OCT system The system, operating at 1300 nm, has an A-line acquisition rate of 200 kHz. We measured the phase noise floor to be 6.5 pm±3.2 pm by placing a cover slip in the sample arm, while blocking the reference arm. We then conducted a vibrational frequency test by measuring the phase response from a polymer membrane stimulated by a pure tone acoustic wave from 10 kHz to 80 kHz. The measured frequency response agreed with the known stimulation frequency with an error < 0.005%. We further measured the phase response of 7 fresh swine hearts obtained from Green Village Packing Company through a mechanical stretching test, within 24 hours of sacrifice. The heart tissue was cut into a 1 mm slices and fixed on two motorized stages. We acquired 100,000 consecutive M-scans, while the sample is stretched at a constant velocity of 10 um/s. The depth-resolved phase image presents linear phase response over time at each depth, but the slope varies among tissue types. Our future work includes refining our experiment protocol to quantitatively measured the elastic modulus of the tissue in vivo and building a tissue classifier based on depth-resolved phase information.

  3. Visualization investigation of acoustic and flow-induced vibration in main stream lines using a high-time-resolved PIV technique

    International Nuclear Information System (INIS)

    Li, Yanrong; Someya, Satoshi; Okamoto, Koji

    2009-01-01

    Systems with closed side-branches are liable to an excitation of sound, as called cavity tone. It may occur in pipe branches leading to safety valves or to boiler relief valves. The outbreak mechanism of the cavity tone has been known by phase-averaged measurement in previous researches, while the relation between sound propagation and flow field is still unclear due to the difficulty of detecting instantaneous velocity field. High-time-resolved PIV has a possibility to analyze the velocity field and the relation mentioned above. In this study, flow-induced acoustic resonance of piping system containing closed side-branches was investigated experimentally. A high-time-resolved PIV technique was applied to measure a gas-flow in a cavity. Air flow containing oil mist as tracer particles was measured using a high frequency pulse laser and a high speed camera. The present investigation on the coaxial closed side-branches is the first rudimentary study to visualize the fluid flow two-dimensionally in the cross-section by using PIV and to measure the pressure at the downstream side opening of the cavity by microphone. The fluid flows at different points in the cavity interact with some phase differences and the relation was clarified. (author)

  4. High-resolution, time-resolved MRA provides superior definition of lower-extremity arterial segments compared to 2D time-of-flight imaging.

    Science.gov (United States)

    Thornton, F J; Du, J; Suleiman, S A; Dieter, R; Tefera, G; Pillai, K R; Korosec, F R; Mistretta, C A; Grist, T M

    2006-08-01

    To evaluate a novel time-resolved contrast-enhanced (CE) projection reconstruction (PR) magnetic resonance angiography (MRA) method for identifying potential bypass graft target vessels in patients with Class II-IV peripheral vascular disease. Twenty patients (M:F = 15:5, mean age = 58 years, range = 48-83 years), were recruited from routine MRA referrals. All imaging was performed on a 1.5 T MRI system with fast gradients (Signa LX; GE Healthcare, Waukesha, WI). Images were acquired with a novel technique that combined undersampled PR with a time-resolved acquisition to yield an MRA method with high temporal and spatial resolution. The method is called PR hyper time-resolved imaging of contrast kinetics (PR-hyperTRICKS). Quantitative and qualitative analyses were used to compare two-dimensional (2D) time-of-flight (TOF) and PR-hyperTRICKS in 13 arterial segments per lower extremity. Statistical analysis was performed with the Wilcoxon signed-rank test. Fifteen percent (77/517) of the vessels were scored as missing or nondiagnostic with 2D TOF, but were scored as diagnostic with PR-hyperTRICKS. Image quality was superior with PR-hyperTRICKS vs. 2D TOF (on a four-point scale, mean rank = 3.3 +/- 1.2 vs. 2.9 +/- 1.2, P < 0.0001). PR-hyperTRICKS produced images with high contrast-to-noise ratios (CNR) and high spatial and temporal resolution. 2D TOF images were of inferior quality due to moderate spatial resolution, inferior CNR, greater flow-related artifacts, and absence of temporal resolution. PR-hyperTRICKS provides superior preoperative assessment of lower limb ischemia compared to 2D TOF.

  5. Highly spatially resolved structural and optical investigation of Bi nanoparticles in Y-Er disilicate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Scarangella, A. [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Amiard, G.; Boninelli, S., E-mail: simona.boninelli@ct.infn.it; Miritello, M. [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Reitano, R. [Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Priolo, F. [CNR IMM-MATIS, Via S. Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Università di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

    2016-08-08

    Er-containing silicon compatible materials have been widely used as infrared emitters for microphotonics application. In this field, the additional introduction of a proper sensitizer permits to increase the Er excitation cross sections, thus increasing its optical efficiency. This work aims to investigate the influence of a post-transition metal, bismuth, on the optical properties of erbium-yttrium disilicate thin films synthesized by magnetron co-sputtering. After thermal treatments at 1000 °C in O{sub 2} or N{sub 2} environment, the presence of small precipitates, about 6 nm in diameter, was evidenced by transmission electron microscopy analyses. The spatially resolved chemical nature of the nanoparticles was discerned in the Si and O rich environments by means of scanning transmission electron microscopy–energy dispersive X-ray and scanning transmission electron microscopy–electron energy loss spectroscopy analyses performed with nanometric resolution. In particular, metallic Bi nanoparticles were stabilized in the N{sub 2} environment, being strongly detrimental for the Er emission. A different scenario was instead observed in O{sub 2}, where the formation of Bi silicate nanoparticles was demonstrated with the support of photoluminescence excitation spectroscopy. In particular, a broad band peaked at 255 nm, correlated to the excitation band of Bi silicate nanoparticles, was identified in Er excitation spectrum. Thus Bi silicate clusters act as sensitizer for Er ions, permitting to improve Er emission up to 250 times with respect to the resonant condition. Moreover, the Er decay time increases in the presence of the Bi silicate nanoparticles that act as cages for Er ions. These last results permit to further increase Er optical efficiency in the infrared range, suggesting (Bi + Er)-Y disilicate as a good candidate for applications in microphotonics.

  6. Eddy covariance measurements with high-resolution time-of-flight aerosol mass spectrometry: a new approach to chemically resolved aerosol fluxes

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2011-06-01

    Full Text Available Although laboratory studies show that biogenic volatile organic compounds (VOCs yield substantial secondary organic aerosol (SOA, production of biogenic SOA as indicated by upward fluxes has not been conclusively observed over forests. Further, while aerosols are known to deposit to surfaces, few techniques exist to provide chemically-resolved particle deposition fluxes. To better constrain aerosol sources and sinks, we have developed a new technique to directly measure fluxes of chemically-resolved submicron aerosols using the high-resolution time-of-flight aerosol mass spectrometer (HR-AMS in a new, fast eddy covariance mode. This approach takes advantage of the instrument's ability to quantitatively identify both organic and inorganic components, including ammonium, sulphate and nitrate, at a temporal resolution of several Hz. The new approach has been successfully deployed over a temperate ponderosa pine plantation in California during the BEARPEX-2007 campaign, providing both total and chemically resolved non-refractory (NR PM1 fluxes. Average deposition velocities for total NR-PM1 aerosol at noon were 2.05 ± 0.04 mm s−1. Using a high resolution measurement of the NH2+ and NH3+ fragments, we demonstrate the first eddy covariance flux measurements of particulate ammonium, which show a noon-time deposition velocity of 1.9 ± 0.7 mm s−1 and are dominated by deposition of ammonium sulphate.

  7. Spatially and spectrally resolved photoluminescence of InGaN MQWs grown on highly Si doped a-plane GaN buffer

    Energy Technology Data Exchange (ETDEWEB)

    Thunert, Martin; Wieneke, Matthias; Dempewolf, Anja; Bertram, Frank; Dadgar, Armin; Krost, Alois; Christen, Juergen [Institute of Experimental Physics, Otto-von-Guericke-University Magdeburg (Germany)

    2011-07-01

    A set of InGaN multi quantum well (MQW) samples grown by MOVPE on highly Si doped a-plane GaN on r-plane sapphire templates has been investigated using spatially resolved photoluminescence spectroscopy ({mu}-PL). The Si doping level of nominal about 10{sup 20} cm{sup -3} leads to three dimensionally grown crystallites mostly terminated by m-facets. The MQW thickness has been systematically varied from nominally 2.1 to 4.2 nm, as well as the InGaN growth temperature, which was varied from 760 C to 700 C. The growth of a-plane GaN based devices leads to a non-polar growth direction avoiding the polarization field affected Quantum-Confined-Stark-Effect. Spatially resolved PL studies show for all samples low near band edge (NBE) GaN emission intensity over the whole area under investigation accompanied by highly intense InGaN MQW emission for single crystallites. The MQW luminescence shows a systematic blueshift with increasing InGaN growth temperature due to lower In incorporation as well as a systematic redshift with increasing MQW thickness. Excitation power dependent spectra at 4 K as well as temperature dependent PL spectra will be presented.

  8. Investigations of lateral and vertical compositional gradients in Cu(In,Ga)Se{sub 2} by highly spatially, spectrally and time resolved cathodoluminescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Mathias; Ribbe, Stefan; Hempel, Thomas; Bertram, Frank; Christen, Juergen [Institute for Experimental Physics, Otto-von-Guericke-University, Magdeburg (Germany); Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

    2011-07-01

    Luminescence properties of Cu(In,Ga)Se{sub 2} (CIGS) layers with different thicknesses were investigated by means of highly spatially, spectrally and time resolved cathodoluminescence (CL) spectroscopy at low temperature (T=5 K). A polycrystalline CIGS thin film with a thickness of 2.4 {mu}m was grown using an in-line co-evaporation process with a final Cu-poor composition on top of a sputtered Mo layer on a soda lime glass substrate. The layer thickness was then reduced by highly controlled bromine methanol etching. The typical grainy (d{sub average}=3 {mu}m) structure of the untouched sample develops thin longish structures under the influence of the etchant. Integral CL spectra of the samples are dominated by donor-acceptor pair (DAP) luminescence. The peak energies of these spectra are ranging from 1.13 eV to 1.22 eV with decreasing layer thickness. The lateral distribution of the luminescence is inhomogeneous regarding the intensity as well as the peak energy. Time resolved CL shows a strong dependence of the initial lifetime from the emission energy.

  9. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

    International Nuclear Information System (INIS)

    Mayr, Lukas; Klötzer, Bernhard; Penner, Simon; Rameshan, Raffael; Rameshan, Christoph

    2014-01-01

    An ultra-high vacuum (UHV) setup for “real” and “inverse” model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, “magic angle”) and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown

  10. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

    Science.gov (United States)

    Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

    2014-05-01

    An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

  11. Recombination dynamics in coalesced a-plane GaN ELO structures investigated by high spatially and ps-time-resolved cathodoluminescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bastek, B.; Bertram, F.; Christen, J. [Institute of Experimental Physics, Otto-von-Guericke-University Magdeburg (Germany); Wernicke, T.; Weyers, M. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Berlin (Germany); Kneissl, M. [Institute of Solid State Physics, Technical University, Berlin (Germany)

    2008-07-01

    The characteristic epitaxial lateral overgrowth (ELO) domains of fully coalesced a-plane GaN layers were directly imaged by highly spatially and spectrally resolved cathodoluminescence microscopy (CL) at 5 K. The patterned layers were grown by MOVPE on r-plane sapphire substrate and stripe masks oriented in the [01 anti 10] direction. In the area of coherent growth (I) the broad basal plane stacking fault (BSF) emission centered at 3.41 eV dominates the spectra. Also in the region (II) of coalescence the BSF luminescence dominates, however, the intensity increases by one order of magnitude compared to area (I). In complete contrast, in the stripes associated with the laterally grown domains (III) in [0001] direction, exclusively an intense and sharp (D{sup 0},X) emission at 3.475 eV is observed. ps-time-resolved CL of the free excitons (FX) recorded from this domains (III) decays bi-exponentially. The initial lifetime of 180 ps is primarily given by the capture of FX by impurities to form bound excitons (BE). With rising temperature this capture time constant decreases as T{sup -1/4} and reaches a minimum of 104 ps at T=60 K. Above 60 K, i.e. when FX starts to dominate the BEs, the lifetime increases rapidly to a value of 240 ps for 300 K.

  12. Time-resolved investigation of dual high power impulse magnetron sputtering with closed magnetic field during deposition of Ti-Cu thin films

    International Nuclear Information System (INIS)

    Stranak, Vitezslav; Hippler, Rainer; Cada, Martin; Hubicka, Zdenek; Tichy, Milan

    2010-01-01

    Time-resolved comparative study of dual magnetron sputtering (dual-MS) and dual high power impulse magnetron sputtering (dual-HiPIMS) systems arranged with closed magnetic field is presented. The dual-MS system was operated with a repetition frequency 4.65 kHz (duty cycle ≅50%). The frequency during dual-HiPIMS is lower as well as its duty cycle (f=100 Hz, duty 1%). Different metallic targets (Ti, Cu) and different cathode voltages were applied to get required stoichiometry of Ti-Cu thin films. The plasma parameters of the interspace between magnetrons in the substrate position were investigated by time-resolved optical emission spectroscopy, Langmuir probe technique, and measurement of ion fluxes to the substrate. It is shown that plasma density as well as ion flux is higher about two orders of magnitude in dual-HiPIMS system. This fact is partially caused by low diffusion of ionized sputtered particles (Ti + ,Cu + ) which creates a preionized medium.

  13. A Q-switched Ho:YAG laser assisted nanosecond time-resolved T-jump transient mid-IR absorbance spectroscopy with high sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Deyong; Li, Yunliang; Li, Hao; Weng, Yuxiang, E-mail: yxweng@iphy.ac.cn [Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Xianyou [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China); Yu, Qingxu [School of Physics and Optoelectronic Technology, Dalian University of Technology, No. 2, Linggong Road, Dalian 116023 (China)

    2015-05-15

    Knowledge of dynamical structure of protein is an important clue to understand its biological function in vivo. Temperature-jump (T-jump) time-resolved transient mid-IR absorbance spectroscopy is a powerful tool in elucidating the protein dynamical structures and the folding/unfolding kinetics of proteins in solution. A home-built setup of T-jump time-resolved transient mid-IR absorbance spectroscopy with high sensitivity is developed, which is composed of a Q-switched Cr, Tm, Ho:YAG laser with an output wavelength at 2.09 μm as the T-jump heating source, and a continuous working CO laser tunable from 1580 to 1980 cm{sup −1} as the IR probe. The results demonstrate that this system has a sensitivity of 1 × 10{sup −4} ΔOD for a single wavelength detection, and 2 × 10{sup −4} ΔOD for spectral detection in amide I′ region, as well as a temporal resolution of 20 ns. Moreover, the data quality coming from the CO laser is comparable to the one using the commercial quantum cascade laser.

  14. Investigating the capability to resolve complex white matter structures with high b-value diffusion magnetic resonance imaging on the MGH-USC Connectom scanner.

    Science.gov (United States)

    Fan, Qiuyun; Nummenmaa, Aapo; Witzel, Thomas; Zanzonico, Roberta; Keil, Boris; Cauley, Stephen; Polimeni, Jonathan R; Tisdall, Dylan; Van Dijk, Koene R A; Buckner, Randy L; Wedeen, Van J; Rosen, Bruce R; Wald, Lawrence L

    2014-11-01

    One of the major goals of the NIH Blueprint Human Connectome Project was to map and quantify the white matter connections in the brain using diffusion tractography. Given the prevalence of complex white matter structures, the capability of resolving local white matter geometries with multiple crossings in the diffusion magnetic resonance imaging (dMRI) data is critical. Increasing b-value has been suggested for delineation of the finer details of the orientation distribution function (ODF). Although increased gradient strength and duration increase sensitivity to highly restricted intra-axonal water, gradient strength limitations require longer echo times (TE) to accommodate the increased diffusion encoding times needed to achieve a higher b-value, exponentially lowering the signal-to-noise ratio of the acquisition. To mitigate this effect, the MGH-USC Connectom scanner was built with 300 mT/m gradients, which can significantly reduce the TE of high b-value diffusion imaging. Here we report comparisons performed across b-values based on q-ball ODF metrics to investigate whether high b-value diffusion imaging on the Connectom scanner can improve resolving complex white matter structures. The q-ball ODF features became sharper as the b-value increased, with increased power fraction in higher order spherical harmonic series of the ODF and increased peak heights relative to the overall size of the ODF. Crossing structures were detected in an increasingly larger fraction of white matter voxels and the spatial distribution of two-way and three-way crossing structures was largely consistent with known anatomy. Results indicate that dMRI with high diffusion encoding on the Connectom system is a promising tool to better characterize, and ultimately understand, the underlying structural organization and motifs in the human brain.

  15. Time- and angle-resolved photoemission spectroscopy with optimized high-harmonic pulses using frequency-doubled Ti:Sapphire lasers

    International Nuclear Information System (INIS)

    Eich, S.; Stange, A.; Carr, A.V.; Urbancic, J.; Popmintchev, T.; Wiesenmayer, M.; Jansen, K.; Ruffing, A.; Jakobs, S.; Rohwer, T.; Hellmann, S.; Chen, C.; Matyba, P.; Kipp, L.; Rossnagel, K.; Bauer, M.; Murnane, M.M.; Kapteyn, H.C.; Mathias, S.; Aeschlimann, M.

    2014-01-01

    Highlights: • We present a scheme to generate high intensity XUV pulses from HHG with variable time-bandwidth product. • Shorter-wavelength driven high-harmonic XUV trARPES provides higher photon flux and increased energy resolution. • High-quality high-harmonic XUV trARPES data with sub 150 meV energy and sub 30 fs time resolution is presented. - Abstract: Time- and angle-resolved photoemission spectroscopy (trARPES) using femtosecond extreme ultraviolet high harmonics has recently emerged as a powerful tool for investigating ultrafast quasiparticle dynamics in correlated-electron materials. However, the full potential of this approach has not yet been achieved because, to date, high harmonics generated by 800 nm wavelength Ti:Sapphire lasers required a trade-off between photon flux, energy and time resolution. Photoemission spectroscopy requires a quasi-monochromatic output, but dispersive optical elements that select a single harmonic can significantly reduce the photon flux and time resolution. Here we show that 400 nm driven high harmonic extreme-ultraviolet trARPES is superior to using 800 nm laser drivers since it eliminates the need for any spectral selection, thereby increasing photon flux and energy resolution to <150 meV while preserving excellent time resolution of about 30 fs

  16. A new automated assign and analysing method for high-resolution rotationally resolved spectra using genetic algorithms

    NARCIS (Netherlands)

    Meerts, W.L.; Schmitt, M.

    2006-01-01

    This paper describes a numerical technique that has recently been developed to automatically assign and fit high-resolution spectra. The method makes use of genetic algorithms (GA). The current algorithm is compared with previously used analysing methods. The general features of the GA and its

  17. Perceptions of International Female Students toward E-Learning in Resolving High Education and Family Role Strain

    Science.gov (United States)

    Kibelloh, Mboni; Bao, Yukun

    2014-01-01

    It is a common phenomenon for many mature female international students enrolled in high education overseas to experience strain from managing conflicting roles of student and family, and difficulties of cross-cultural adjustment. The purpose of this study is to examine perceptions and behavioral intentions of international female students toward…

  18. Time-resolved electron thermal conduction by probing of plasma formation in transparent solids with high power subpicosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Vu, Brian -Tinh Van [Univ. of California, Davis, CA (United States)

    1994-02-01

    This dissertation work includes a series of experimental measurements in a search for better understanding of high temperature (104-106K) and high density plasmas (1022-1024cm-3) produced by irradiating a transparent solid target with high intensity (1013 - 1015W/cm2) and subpicosecond (10-12-10-13s) laser pulses. Experimentally, pump and probe schemes with both frontside (vacuum-plasma side) and backside (plasma-bulk material side) probes are used to excite and interrogate or probe the plasma evolution, thereby providing useful insights into the plasma formation mechanisms. A series of different experiments has been carried out so as to characterize plasma parameters and the importance of various nonlinear processes. Experimental evidence shows that electron thermal conduction is supersonic in a time scale of the first picosecond after laser irradiation, so fast that it was often left unresolved in the past. The experimental results from frontside probing demonstrate that upon irradiation with a strong (pump) laser pulse, a thin high temperature (~40eV) super-critical density (~1023/cm3) plasma layer is quickly formed at the target surface which in turn becomes strongly reflective and prevents further transmission of the remainder of the laser pulse. In the bulk region behind the surface, it is also found that a large sub-critical (~1018/cm3) plasma is produced by inverse Bremsstrahlung absorption and collisional ionization. The bulk underdense plasma is evidenced by large absorption of the backside probe light. A simple and analytical model, modified from the avalanche model, for plasma evolution in transparent materials is proposed to explain the experimental results. Elimination of the bulk plasma is then experimentally illustrated by using targets overcoated with highly absorptive films.

  19. Time-resolved electron thermal conduction by probing of plasma formation in transparent solids with high power subpicosecond laser pulses

    International Nuclear Information System (INIS)

    Vu, B.T.V.

    1994-02-01

    This dissertation work includes a series of experimental measurements in a search for better understanding of high temperature (10 4 -10 6 K) and high density plasmas (10 22 -10 24 cm -3 ) produced by irradiating a transparent solid target with high intensity (10 13 - 10 15 W/cm 2 ) and subpicosecond (10 -12 -10 -13 s) laser pulses. Experimentally, pump and probe schemes with both frontside (vacuum-plasma side) and backside (plasma-bulk material side) probes are used to excite and interrogate or probe the plasma evolution, thereby providing useful insights into the plasma formation mechanisms. A series of different experiments has been carried out so as to characterize plasma parameters and the importance of various nonlinear processes. Experimental evidence shows that electron thermal conduction is supersonic in a time scale of the first picosecond after laser irradiation, so fast that it was often left unresolved in the past. The experimental results from frontside probing demonstrate that upon irradiation with a strong (pump) laser pulse, a thin high temperature (∼40eV) super-critical density (∼10 23 /cm 3 ) plasma layer is quickly formed at the target surface which in turn becomes strongly reflective and prevents further transmission of the remainder of the laser pulse. In the bulk region behind the surface, it is also found that a large sub-critical (∼10 18 /cm 3 ) plasma is produced by inverse Bremsstrahlung absorption and collisional ionization. The bulk underdense plasma is evidenced by large absorption of the backside probe light. A simple and analytical model, modified from the avalanche model, for plasma evolution in transparent materials is proposed to explain the experimental results. Elimination of the bulk plasma is then experimentally illustrated by using targets overcoated with highly absorptive films

  20. High-Resolution Metallic Magnetic Calorimeters for beta-Spectroscopy on 187-Rhenium and Position Resolved X-Ray Spectroscopy

    OpenAIRE

    Porst, Jan-Patrick

    2010-01-01

    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass mea...

  1. Predicting the heat of vaporization of iron at high temperatures using time-resolved laser-induced incandescence and Bayesian model selection

    Science.gov (United States)

    Sipkens, Timothy A.; Hadwin, Paul J.; Grauer, Samuel J.; Daun, Kyle J.

    2018-03-01

    Competing theories have been proposed to account for how the latent heat of vaporization of liquid iron varies with temperature, but experimental confirmation remains elusive, particularly at high temperatures. We propose time-resolved laser-induced incandescence measurements on iron nanoparticles combined with Bayesian model plausibility, as a novel method for evaluating these relationships. Our approach scores the explanatory power of candidate models, accounting for parameter uncertainty, model complexity, measurement noise, and goodness-of-fit. The approach is first validated with simulated data and then applied to experimental data for iron nanoparticles in argon. Our results justify the use of Román's equation to account for the temperature dependence of the latent heat of vaporization of liquid iron.

  2. Properties of laser-produced GaAs plasmas measured from highly resolved X-ray line shapes and ratios

    Science.gov (United States)

    Seely, J. F.; Fein, J.; Manuel, M.; Keiter, P.; Drake, P.; Kuranz, C.; Belancourt, Patrick; Ralchenko, Yu.; Hudson, L.; Feldman, U.

    2018-03-01

    The properties of hot, dense plasmas generated by the irradiation of GaAs targets by the Titan laser at Lawrence Livermore National Laboratory were determined by the analysis of high resolution K shell spectra in the 9 keV to 11 keV range. The laser parameters, such as relatively long pulse duration and large focal spot, were chosen to produce a steady-state plasma with minimal edge gradients, and the time-integrated spectra were compared to non-LTE steady state spectrum simulations using the FLYCHK and NOMAD codes. The bulk plasma streaming velocity was measured from the energy shifts of the Ga He-like transitions and Li-like dielectronic satellites. The electron density and the electron energy distribution, both the thermal and the hot non-thermal components, were determined from the spectral line ratios. After accounting for the spectral line broadening contributions, the plasma turbulent motion was measured from the residual line widths. The ionization balance was determined from the ratios of the He-like through F-like spectral features. The detailed comparison of the experimental Ga spectrum and the spectrum simulated by the FLYCHK code indicates two significant discrepancies, the transition energy of a Li-like dielectronic satellite (designated t) and the calculated intensity of a He-like line (x), that should lead to improvements in the kinetics codes used to simulate the X-ray spectra from highly-charged ions.

  3. Resolving the age of Wilson Creek Formation tephras and the Mono Lake excursion using high-resolution SIMS dating of allanite and zircon rims

    Science.gov (United States)

    Vazquez, J. A.; Lidzbarski, M. I.

    2012-12-01

    Sediments of the Wilson Creek Formation surrounding Mono Lake preserve a high-resolution archive of glacial and pluvial responses along the eastern Sierra Nevada due to late Pleistocene climate change. An absolute chronology for the Wilson Creek stratigraphy is critical for correlating the paleoclimate record to other archives in the western U.S. and the North Atlantic region. However, multiple attempts to date the Wilson Creek stratigraphy using carbonates and interbedded rhyolitic tephras yield discordant 14C and 40Ar/39Ar results due to open-system effects, carbon reservoir uncertainties, as well as abundant xenocrysts entrained during eruption. Ion microprobe (SIMS) 238U-230Th dating of the final increments of crystallization recorded by allanite and zircon autocrysts from juvenile pyroclasts yields ages that effectively date eruption of key tephra beds and resolve age uncertainties about the Wilson Creek stratigraphy. To date the final several micrometers of crystal growth, individual allanite and zircon crystals were embedded in soft indium to allow sampling of unpolished rims. Isochron ages derived from rims on coexisting allanite and zircon (± glass) from hand-selected pumiceous pyroclasts delimit the timing of Wilson Creek sedimentation between Ashes 7 and 19 (numbering of Lajoie, 1968) to the interval between ca. 27 to ca. 62 ka. The interiors of individual allanite and zircon crystals sectioned in standard SIMS mounts yield model 238U-230Th ages that are mostly hydrologic responses in the Sierra Nevada and Mono Basin to climate change, with intervals of lake filling and glacial-snowpack melting that are in phase with peaks in spring insolation. Moreover, the results demonstrate that high-spatial resolution SIMS dating of accessory mineral rims is an alternative and promising approach for resolving the depositional ages of silicic tephras containing minerals that crystallized over protracted intervals or that are plagued by incorporation of xenocrysts

  4. High time-resolved chemical compositions, sources and evolution for atmospheric submicron aerosols in the winter of Beijing

    Science.gov (United States)

    Min, H.; Hu, W.; Zheng, J.; Guo, S.; Wu, Y.; Zeng, L.; Lu, S.; Xie, S.; Zhang, Y.

    2017-12-01

    Severe regional haze problem in the megacity Beijing and surrounding areas has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, intensive campaigns were conducted in the winter of 2010 and 2013 at an urban site in Beijing. An Aerodyne high resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure chemical components of PM1, coupled with multiple state of the art online instruments. In the winter of 2010, PM1 mass concentrations changed dramatically along with meteorological conditions. The high average fraction (58%) of primary species in PM1 indicated that primary emissions usually played a more important role. Based on the source apportionment results, 45% POA are from non-fossil sources, contributed by cooking OA and biomass burning OA (BBOA). Cooking OA, accounting for 13-24% of OA, is an important non-fossil carbon source in all years of Beijing and should not be neglected. The fossil sources of POA include hydrocarbon-like OA from vehicle emissions and coal combustion OA (CCOA). The CCOA and BBOA were the two main contributors (57% of OA) for the highest OA concentrations (>100 μg m-3). In the winter of 2013, OOA (MO-OOA and LO-OOA), accounted for 50% of PM1, while (OOA+SNA) contributed 60-80%, suggesting that secondary formation played an important role in the PM pollution. In the winter of 2010 higher OOA/Ox (= NO2 + O3) ratio (0.49 μg m-3 ppb-1) than these ratios from western cities (0.03-0.16 μg m-3 ppb-1) was observed, which may be due to the aqueous reaction or extra SOA formation contributed by semi-VOCs from various primary sources (e.g., BBOA or CCOA). However, aqueous chemistry resulting in efficient secondary formation during occasional periods with high relative humidity may also contribute substantially to haze in winter. CCOA was only identified in winter due to domestic heating. These results signified that the comprehensive

  5. High definition for systems biology of microbial communities: metagenomics gets genome-centric and strain-resolved.

    Science.gov (United States)

    Turaev, Dmitrij; Rattei, Thomas

    2016-06-01

    The systems biology of microbial communities, organismal communities inhabiting all ecological niches on earth, has in recent years been strongly facilitated by the rapid development of experimental, sequencing and data analysis methods. Novel experimental approaches and binning methods in metagenomics render the semi-automatic reconstructions of near-complete genomes of uncultivable bacteria possible, while advances in high-resolution amplicon analysis allow for efficient and less biased taxonomic community characterization. This will also facilitate predictive modeling approaches, hitherto limited by the low resolution of metagenomic data. In this review, we pinpoint the most promising current developments in metagenomics. They facilitate microbial systems biology towards a systemic understanding of mechanisms in microbial communities with scopes of application in many areas of our daily life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A highly spatially resolved GIS-based model to assess the isoprenoid emissions from key Italian ecosystems

    Science.gov (United States)

    Pacheco, Claudia Kemper; Fares, Silvano; Ciccioli, Paolo

    2014-10-01

    The amount of Biogenic Volatile Organic Compounds (BVOC) emitted from terrestrial vegetation is of great importance in atmospheric reactivity, particularly for ozone-forming reactions and as condensation nuclei in aerosol formation and growth. This work presents a detailed inventory of isoprenoid emissions from vegetation in Italy using an original approach which combines state of the art models to estimate the species-specific isoprenoid emissions and a Geographic Information System (GIS) where emissions are spatially represented. Isoprenoid species and basal emission factors were obtained by combining results from laboratory experiments with those published in literature. For the first time, our investigation was not only restricted to isoprene and total monoterpenes, but our goal was to provide maps of isoprene and individual monoterpenes at a high-spatial (∼1 km2) and temporal resolution (daily runs, monthly trends in emissions are discussed in the text). Another novelty in our research was the inclusion of the effects of phenology on plant emissions. Our results show that: a) isoprene, a-pinene, sabinene and b-pinene are the most important compounds emitted from vegetation in Italy; b) annual biogenic isoprene and monoterpene fluxes for the year 2006 were ∼31.30 Gg and ∼37.70 Gg, respectively; and c) Quercus pubescens + Quercus petrea + Quercus robur, Quercus ilex, Quercus suber and Fagus sylvatica are the principal isoprenoid emitting species in the country. The high spatial and temporal resolution, combined with the species-specific emission output, makes the model particularly suitable for assessing local budgets, and for modeling photochemical pollution in Italy.

  7. High-time resolved measurements of biogenic and anthropogenic secondary organic aerosol precursors and products in urban air

    Science.gov (United States)

    Flores, Rosa M.; Doskey, Paul V.

    2016-04-01

    Volatile organic compounds (VOCs), which are present in the atmosphere entirely in the gas phase are directly emitted by biogenic (~1089 Tg yr-1) and anthropogenic sources (~185 Tg yr-1). However, the sources and molecular speciation of intermediate VOCs (IVOCs), which are for the most part also present almost entirely in the gas phase, are not well characterized. The VOCs and IVOCs participate in reactions that form ozone and semivolatile OC (SVOC) that partition into the aerosol phase. Formation and evolution of secondary organic aerosol (SOA) are part of a complex dynamic process that depends on the molecular speciation and concentration of VOCs, IVOCs, primary organic aerosol (POA), and the level of oxidants (NO3, OH, O3). The current lack of understanding of OA properties and their impact on radiative forcing, ecosystems, and human health is partly due to limitations of models to predict SOA production on local, regional, and global scales. More accurate forecasting of SOA production requires high-temporal resolution measurement and molecular characterization of SOA precursors and products. For the subject study, the IVOCs and aerosol-phase organic matter were collected using the high-volume sampling technique and were analyzed by multidimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-ToFMS). The IVOCs included terpenes, terpenoids, n-alkanes, branched alkanes, isoprenoids, alkylbenzenes, cycloalkylbenzenes, PAH, alkyl PAH, and an unresolved complex mixture (UCM). Diurnal variations of OA species containing multiple oxygenated functionalities and selected SOA tracers of isorprene, α-pinene, toluene, cyclohexene, and n-dodecane oxidation were also quantified. The data for SOA precursor and oxidation products presented here will be useful for evaluating the ability of molecular-specific SOA models to forecast SOA production in and downwind of urban areas.

  8. Are low and high number magnitudes processed differently while resolving the conflict evoked by the SNARC effect?

    Science.gov (United States)

    Gut, Małgorzata; Szumska, Izabela; Wasilewska, Marzena; Jaśkowski, Piotr

    2012-07-01

    In the brain, numbers are thought to be represented in a spatially organised fashion on what is known as the Mental Number Line (MNL). The SNARC (Spatial-Numerical Association of Response Codes) effect refers to the faster responses to digits when the reaction side is congruent with the digit position on the MNL (e.g. a left-handed response to a small magnitude) and the slowing down of responses (inhibition) in the case of incongruity. We examined the electrophysiological correlates of conflict, which are linked to that of inhibition, to shed light on the relationship between the SNARC effect and executive attention. Event-related potentials (ERPs) were recorded from twenty-nine participants during a parity-judgment task. The participants responded more quickly on congruent than on incongruent trials. The congruency effect was reflected in early sensory (N1, N2) components above parieto-occipital and frontal regions, as well as in the later P3 component above centro-parietal areas. Moreover, both the N1 amplitude and N2 latency were greater with high than low magnitude digit targets. P3 amplitude modulation implies that the SNARC effect is the result of first evoking the parallel processing of digit magnitude categorisation (in the occipital and central areas) and numeric conflict detection (in the parieto-occipital and frontal areas) and secondly conflict monitoring and resolution localised in the centro-parietal and frontal sites. These results also suggest that the left hemisphere specialises in conflict processing of high magnitude digit targets, while the right hemisphere of low digit magnitudes. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Highly resolving Rutherford-scattering spectrometry for the study of ZrO2 layer growth in the beginning stage

    International Nuclear Information System (INIS)

    Vieluf, Maik

    2010-06-01

    By means of High Resolution Rutherford Backscattering Spectrometry (HR-RBS) the diffusion behaviour and layer growth of ZrO 2 on SiO 2 and TiN in the initial regime were investigated. The analysis of concentration profiles in ultrathin layers and interfaces was the focus of this work, made possible by the excellent depth resolution of less than 0.3 nm near the surface. For the first time a two-dimensional position sensitive semiconductor detector was implemented and characterized in the setup of the HR-RBS for the improvement of the quality of the measurement results. Furthermore, a measurement procedure was put into operation that allowed the reduction of ion induced damage. Through the optimization of the experimental conditions and the development of a program package for the support of the analyst, an efficient measurement procedure could be routinely ensured. At the time of a binary collision between the incident ion and the target element with a small impact factor, the charge state changes frequently, especially due to the abruptly decreasing ion velocity of the projectile and the overlapping of the electron clouds. For HR-RBS with an energy-separating dipole magnet, the charge state distribution of the scattered ions must be known for the interpretation of the measured spectra. For the first time a significant dependence of the charge state distribution of the scattered C ions on the layer thickness as well as atomic number of the detected target elements, here from the fourth subgroup, was demonstrated. This new knowledge allowed systematic investigations of the ZrO 2 layer growth in the initial regime. The ZrO 2 layers were produced by means of the atomic layer deposition (ALD). Based on the evidence for agglomeration of ZrO 2 on SiO 2 a method was introduced, which takes local thickness variations into account during the simulation of the HR-RBS spectra. An accurate statement about the ZrO 2 /SiO 2 interface was possible due to the extraction of the

  10. Time-resolved QXAFS studies on the formation and dynamic behavior of the highly active Pd catalyst

    International Nuclear Information System (INIS)

    Okumura, Kazu

    2009-01-01

    The stepwise growth of Pd in USY zeolite was followed by in situ scanning quick X-ray absorption fine structure (QXAFS) spectroscopy involving repeated alternating exposures to H 2 and O 2 flows at room temperature. During the first reduction of 0.4 wt%-Pd/USY with 8% H 2 , Pd clusters of 13 atoms with a coordination number (CN) of 5.1 formed within 20 min in the supercage of USY. The growth followed first-order kinetics with respect to the concentration of Pd 2+ and the CN of Pd-Pd. The clusters were stable up to 443 K. The clusters were partially oxidized in less than 2 min on exposure to 8% O 2 , and then quickly reduced with 8% H 2 (second reduction) to afford larger Pd clusters of 26 atoms. The clusters continued to increase in size in a stepwise fashion on further alternate exposures to O 2 and H 2 . The finely dispersed Pd 0 species exhibited extremely high activity in the Suzuki-Miyaura coupling reactions when the o-xylene solution was activated with H 2 -bubbling. (author)

  11. High Time-Resolved Kinetic Temperatures of Solar Wind Minor Ions Measured with SOHO/CELIAS/CTOF

    Science.gov (United States)

    Janitzek, N. P.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Solar wind heavy ions with an atomic number Z > 2 are referred to as minor ions since they represent a fraction of less than one percent of all solar wind ions. They can be therefore regarded as test particles, only reacting to but not driving the dynamics of the solar wind plasma, which makes them a unique diagnostic tool for plasma wave phenomena both in the solar atmosphere and the extended heliosphere. In the past, several studies have investigated the kinetic temperatures of minor ions, but due to low counting statistics these studies are based on ion velocity distribution functions (VDFs) recorded over time periods of several hours. The Charge Time-Of-Flight (CTOF) mass spectrometer as part of the Charge, ELement and Isotope Analysis System (CELIAS) onboard the SOlar and Heliospheric Observatory (SOHO) provides solar wind heavy ion 1D radial VDFs with excellent charge state separation, an unprecedented cadence of 5 minutes and very high counting statistics, exceeding similar state-of-the-art instruments by a factor of ten. In our study, based on CTOF measurements at Langrangian point L1 between DOY 150 and DOY 220 in 1996, we investigate systematically the influence of the VDF time resolution on the derived kinetic temperatures for solar wind silicon and iron ions. The selected ion set spans a wide range of mass-per-charge from 3 amu/e heavy ions with ion-cyclotron waves.

  12. A high-resolved record of the Asian Summer Monsoon from Dongge Cave, China for the past 1200 years

    Science.gov (United States)

    Zhao, Kan; Wang, Yongjin; Edwards, R. Lawrence; Cheng, Hai; Liu, Dianbing; Kong, Xinggong

    2015-08-01

    Two annually-laminated and 230Th-dated stalagmite oxygen isotope (δ18O) records from Dongge Cave, China, provided a high-resolution Asian Summer Monsoon (ASM) history for the past 1200 years. A close similarity between annual band thickness and stable isotope analyses (δ13C and δ18O) suggests the calcite δ18O is most likely a proxy associated with ASM precipitation. The two duplicated stalagmite δ18O records show that the ASM varies at a periodicity of ∼220 years, concordant with a dominant cycle of solar activity. A period of strong ASM activity occurred during the Spörer Minimum (1450-1550 A.D.), followed by a striking drop circa 1580 A.D., potentially consistent with the social unrest in the final decades of China's Ming Dynasty (1368-1644 A.D.). Centennial-scale changes in ASM precipitation over the last millennium match well with changes in tropical Atlantic sea surface temperatures (SSTs) and South American summer monsoon precipitation. Our findings suggest that variations in low-latitude monsoon precipitation are probably driven by shifts in the mean position of the intertropical convergence zone (ITCZ), which is further mediated by solar activity and tropical SSTs.

  13. Angularly-resolved elastic scatter from single particles collected over a large solid angle and with high resolution

    International Nuclear Information System (INIS)

    Aptowicz, Kevin B; Chang, Richard K

    2005-01-01

    Elastic light scattering from a single non-spherical particle of various morphologies has been measured simultaneously with a large angular range (90 deg. < θ < 165 deg. and 0 deg. < φ < 360 deg.) and with high angular resolution (1024 pixels in θ and 512 pixels in φ). Because the single-shot laser pulse is short (pulse duration of 70 ns), the tumbling and flowing particle can be treated as frozen in space. The large angle two-dimensional angular optical scattering (hereafter referred to as LA TAOS) intensity pattern, I(θ,φ), has been measured for a variety of particle morphology, such as the following: (1) single polystyrene latex (PSL) sphere; (2) cluster of PSL spheres; (3) single Bacillus subtilis (BG) spore; (4) cluster of BG spores; (5) dried aggregates of bio-aerosols as well as background clutter aerosols. All these measurements were made using the second harmonic of a Nd:YAG laser (0.532 μm). Islands structures in the LA TAOS patterns seem to be the prominent feature. Efforts are being made to extract metrics from these islands and compare them to theoretical results based on the T-matrix method

  14. Sinking towards destiny: High throughput measurement of phytoplankton sinking rates through time-resolved fluorescence plate spectroscopy.

    Science.gov (United States)

    Bannon, Catherine C; Campbell, Douglas A

    2017-01-01

    Diatoms are marine primary producers that sink in part due to the density of their silica frustules. Sinking of these phytoplankters is crucial for both the biological pump that sequesters carbon to the deep ocean and for the life strategy of the organism. Sinking rates have been previously measured through settling columns, or with fluorimeters or video microscopy arranged perpendicularly to the direction of sinking. These side-view techniques require large volumes of culture, specialized equipment and are difficult to scale up to multiple simultaneous measures for screening. We established a method for parallel, large scale analysis of multiple phytoplankton sinking rates through top-view monitoring of chlorophyll a fluorescence in microtitre well plates. We verified the method through experimental analysis of known factors that influence sinking rates, including exponential versus stationary growth phase in species of different cell sizes; Thalassiosira pseudonana CCMP1335, chain-forming Skeletonema marinoi RO5A and Coscinodiscus radiatus CCMP312. We fit decay curves to an algebraic transform of the decrease in fluorescence signal as cells sank away from the fluorometer detector, and then used minimal mechanistic assumptions to extract a sinking rate (m d-1) using an RStudio script, SinkWORX. We thereby detected significant differences in sinking rates as larger diatom cells sank faster than smaller cells, and cultures in stationary phase sank faster than those in exponential phase. Our sinking rate estimates accord well with literature values from previously established methods. This well plate-based method can operate as a high throughput integrative phenotypic screen for factors that influence sinking rates including macromolecular allocations, nutrient availability or uptake rates, chain-length or cell size, degree of silification and progression through growth stages. Alternately the approach can be used to phenomically screen libraries of mutants.

  15. High-resolution metallic magnetic calorimeters for β-spectroscopy on 187rhenium and position resolved X-ray spectroscopy

    International Nuclear Information System (INIS)

    Porst, Jan-Patrick

    2011-01-01

    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for β-endpoint spectroscopy on 187 rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 μs could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than ΔE FWHM <5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

  16. Effect of Cleaving Temperature on the Surface and Bulk Fermi Surface of Sr2RuO4 Investigated by High Resolution Angle-Resolved Photoemission

    International Nuclear Information System (INIS)

    Liu Shan-Yu; Zhang Wen-Tao; Weng Hong-Ming; Zhao Lin; Liu Hai-Yun; Jia Xiao-Wen; Liu Guo-Dong; Dong Xiao-Li; Zhang Jun; Dai Xi; Fang Zhong; Zhou Xing-Jiang; Mao Zhi-Qiang; Chen Chuang-Tian; Xu Zu-Yan

    2012-01-01

    High resolution angle-resolved photoemission measurements are carried out to systematically investigate the effect of cleaving temperature on the electronic structures and Fermi surfaces of Sr 2 RuO 4 . Unlike previous reports, which found that a high cleaving temperature can suppress the surface Fermi surface, we find that the surface Fermi surface remains obvious and strong in Sr 2 RuO 4 cleaved at high temperature, even at room temperature. This indicates that cleaving temperature is not a key effective factor in suppressing surface bands. On the other hand, the bulk bands can be enhanced in an aged surface of Sr 2 RuO 4 that has been cleaved and held for a long time. We have also carried out laser ARPES measurements on Sr 2 RuO 4 by using a vacuum ultra-violet laser (photon energy at 6.994 eV) and found an obvious enhancement of bulk bands even for samples cleaved at low temperature. This information is important for realizing an effective approach to manipulating and detecting the surface and bulk electronic structure of Sr 2 RuO 4 . In particular, the enhancement of bulk sensitivity, along with the super-high instrumental resolution of VUV laser ARPES, will be advantageous in investigating fine electronic structure and superconducting properties of Sr 2 RuO 4 in the future. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  17. Resolving high-frequency internal waves generated at an isolated coral atoll using an unstructured grid ocean model

    Science.gov (United States)

    Rayson, Matthew D.; Ivey, Gregory N.; Jones, Nicole L.; Fringer, Oliver B.

    2018-02-01

    supported by the mooring observations that reveal high frequency lee waves breaking on the turning phase of the tide.

  18. A case study of the highly time-resolved evolution of aerosol chemical and optical properties in urban Shanghai, China

    Directory of Open Access Journals (Sweden)

    Y. Huang

    2013-04-01

    Full Text Available Characteristics of the chemical and optical properties of aerosols in urban Shanghai and their relationship were studied over a three-day period in October 2011. A suite of real-time instruments, including an Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS, a Monitor for AeRosols and GAses (MARGA, a Cavity Ring Down Spectrometer (CRDS, a nephelometer and a Scanning Mobility Particle Sizer (SMPS, was employed to follow the quick changes of the aerosol properties within the 72 h sampling period. The origin of the air mass arriving in Shanghai during this period shifted from the East China Sea to the northwest area of China, offering a unique opportunity to observe the evolution of aerosols influenced by regional transport from the most polluted areas in China. According to the meteorological conditions and temporal characterizations of the chemical and optical properties, the sampling period was divided into three periods. During Period 1 (00:00–23:00 LT, 13 October, the aerosols in urban Shanghai were mainly fresh and the single scattering albedo varied negatively with the emission of elemental carbon, indicating that local sources dominated. Period 2 (23:00 LT on 13 October to 10:00 LT on 15 October was impacted by regionally transported pollutants and had the highest particulate matter (PM mass loading and the lowest particle acidity, characterized by large fractions of aged particles and high secondary ion (nitrate, sulfate and ammonium mass concentrations. Comparison between ATOFMS particle acidity and quantitative particle acidity by MARGA indicated the significance of semi-quantitative calculation in ATOFMS. Two sub-periods were identified in Period 2 based on the scattering efficiency of PM1 mass. Period 3 (from 10:00 LT on 15 October to 00:00 LT on 16 October had a low PM1/PM10 ratio and a new particle formation event. The comparison of these sub-periods highlights the influence of particle mixing state on aerosol optical properties

  19. Four years of highly time resolved measurements of elemental and organic carbon at a rural background site in Central Europe

    Science.gov (United States)

    Mbengue, Saliou; Fusek, Michal; Schwarz, Jaroslav; Vodička, Petr; Šmejkalová, Adéla Holubová; Holoubek, Ivan

    2018-06-01

    Elemental carbon (EC) and organic carbon (OC) in fine atmospheric aerosols (PM2.5: aerodynamic diameter smaller than 2.5 μm) have been measured with a semi-automatic instrument during a 4-year survey at the National Atmospheric Observatory Košetice (NAOK), Czech Republic. Ground based measurements were performed from March 2013 to December 2016 with a field Semi-Continuous OCEC Aerosol Analyzer (Sunset Laboratory Inc., USA). The variation of EC and OC concentrations and the OC/EC ratio was characterized for different seasons and days of the week. During our survey, higher concentrations of EC and OC were observed in winter (0.83 ± 0.67 and 3.33 ± 2.28 μg m-3, respectively), and lower concentrations were recorded in summer (0.34 ± 0.18 and 2.30 ± 1.15 μg m-3, respectively). Inversely, the OC/EC ratio with mean value (5.1 ± 2.6) characteristic to rural background area was higher in summer (7.33 ± 3.23) in comparison to the other seasons. Since the data contain values below detection and quantification limits of the measuring device (i.e., censored values), statistical methods for censored data have been used in order to compare mean EC and OC concentrations between various seasons. It was found out that there is a significant difference between summer and the other seasons with the exception of mean OC concentrations at noon. In most cases, there was also a significant difference between winter and the other seasons. Moreover, it was found out that when dealing with OC concentrations, it is possible to replace censored values by a constant and still obtain reasonable results. In case of EC concentrations, the method based on censored distributions should be preferred when the sample size is small and the proportion of censored values is high. The diurnal variation of EC and OC is less pronounced in summer. During working days, the EC diurnal pattern displays a morning (between 6:00 and 10:00) and an afternoon/evening (between 18:00 and 22:00) peaks, while

  20. Time resolved techniques: An overview

    International Nuclear Information System (INIS)

    Larson, B.C.; Tischler, J.Z.

    1990-06-01

    Synchrotron sources provide exceptional opportunities for carrying out time-resolved x-ray diffraction investigations. The high intensity, high angular resolution, and continuously tunable energy spectrum of synchrotron x-ray beams lend themselves directly to carrying out sophisticated time-resolved x-ray scattering measurements on a wide range of materials and phenomena. When these attributes are coupled with the pulsed time-structure of synchrotron sources, entirely new time-resolved scattering possibilities are opened. Synchrotron beams typically consist of sub-nanosecond pulses of x-rays separated in time by a few tens of nanoseconds to a few hundred nanoseconds so that these beams appear as continuous x-ray sources for investigations of phenomena on time scales ranging from hours down to microseconds. Studies requiring time-resolution ranging from microseconds to fractions of a nanosecond can be carried out in a triggering mode by stimulating the phenomena under investigation in coincidence with the x-ray pulses. Time resolution on the picosecond scale can, in principle, be achieved through the use of streak camera techniques in which the time structure of the individual x-ray pulses are viewed as quasi-continuous sources with ∼100--200 picoseconds duration. Techniques for carrying out time-resolved scattering measurements on time scales varying from picoseconds to kiloseconds at present and proposed synchrotron sources are discussed and examples of time-resolved studies are cited. 17 refs., 8 figs

  1. High-resolution angle-resolved photoemission studies of high Tc superconductor Bi2Sr2CaCu2O8

    International Nuclear Information System (INIS)

    Liu, Rong.

    1990-01-01

    An angle-resolved photoemission study of the normal and superconducting states in Bi 2 Sr 2 CaCu 2 O 8 was performed. Measurements in the normal state show bands dispersing through the Fermi level from at least 350 meV below E F . The Fermi level crossings are consistant with local-density band calculation, including a point calculated to be of Bi-O character. Additional measurements were made where bands crossed the Fermi level between 100 and 250K, along with measurements on an adjacent Pt foil. The Fermi edges of both materials agree to within the noise. Below the Fermi level, the spectra show correlation effects on the form of an increased effective mass. The shape of the spectra can be explained by a lifetime-broadened photohole and secondary electrons. The effective inverse photohole lifetime is linear in energy. A superconducting gap has been measured at a number of points where there is density at the Fermi level in the normal state. By proper modeling, a gap of 24 meV was obtained for all these points, including points of Cu-O and Bi-O character respectively, according to band calculation. The lack of gap anisotropy in the basal plane suggests that pinning in this material is not d-wave pairing

  2. High-Energy Anomaly in the Angle-Resolved Photoemission Spectra of Nd2-xCexCuO4: Evidence for a Matrix Element Effect

    Science.gov (United States)

    Rienks, E. D. L.; ńrrälä, M.; Lindroos, M.; Roth, F.; Tabis, W.; Yu, G.; Greven, M.; Fink, J.

    2014-09-01

    We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd2-xCexCuO4, x =0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.

  3. High-energy anomaly in the angle-resolved photoemission spectra of Nd(2-x)Ce(x)CuO₄: evidence for a matrix element effect.

    Science.gov (United States)

    Rienks, E D L; Ärrälä, M; Lindroos, M; Roth, F; Tabis, W; Yu, G; Greven, M; Fink, J

    2014-09-26

    We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd(2-x)Ce(x)CuO₄, x=0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.

  4. Application of high-resolution photoelectron spectroscopy: Vibrational resolved C 1s and O 1s spectra of CO adsorbed on Ni(100)

    Energy Technology Data Exchange (ETDEWEB)

    Foehlisch, A.; Nilsson, A.; Martensson, N. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    There are various effects which determine the line shape of a core-level electron spectrum. These are due to the finite life-time of the core hole, inelastic scattering of the outgoing photoelectron, electronic shake-up and shake-off processes and vibrational excitations. For free atoms and molecules the different contributions to the observed line shapes can often be well separated. For solids, surfaces and adsorbates the line shapes are in general much broader and it has in the past been assumed that no separation of the various contributions can be made. In the present report the authors will show that this is indeed not the case. Surprisingly, the vibrational fine structure of CO adsorbed on Ni(100) can be resolved in the C 1s and O 1s electron spectra. This was achieved by the combination of highly monochromatized soft X-rays from B18.0 with a high resolution Scienta 200 mm photoelectron spectrometer. X-ray photoelectron spectroscopy (XPS) with tunable excitation energy yields as a core level spectroscopy atomic and site-specific information. The presented measurements allow for a determination of internuclear distances and potential energy curves in corehole ionized adsorbed molecules. The authors analysis of the c(2x2) phase CO/Ni(100) on {open_quotes}top{close_quotes} yielded a vibrational splitting of 217 +/- 2 meV for C 1s ionization. For O 1s ionization a splitting of 173 +/- 8 meV was found.

  5. Policy applications of a highly resolved spatial and temporal onroad carbon dioxide emissions data product for the U.S.: Analyses and their implications for mitigation

    Science.gov (United States)

    Mendoza Lebrun, Daniel

    of CO2 emissions at a highly resolved level. Such a study would improve fossil fuel flux products by enhancing measurement accuracy and prompt location-specific mitigation policy. The carbon cycle science and policymaking communities are both poised to benefit greatly from the development of a highly resolved spatiotemporal emissions product.

  6. Validation of a high-power, time-resolved, near-infrared spectroscopy system for measurement of superficial and deep muscle deoxygenation during exercise.

    Science.gov (United States)

    Koga, Shunsaku; Barstow, Thomas J; Okushima, Dai; Rossiter, Harry B; Kondo, Narihiko; Ohmae, Etsuko; Poole, David C

    2015-06-01

    Near-infrared assessment of skeletal muscle is restricted to superficial tissues due to power limitations of spectroscopic systems. We reasoned that understanding of muscle deoxygenation may be improved by simultaneously interrogating deeper tissues. To achieve this, we modified a high-power (∼8 mW), time-resolved, near-infrared spectroscopy system to increase depth penetration. Precision was first validated using a homogenous optical phantom over a range of inter-optode spacings (OS). Coefficients of variation from 10 measurements were minimal (0.5-1.9%) for absorption (μa), reduced scattering, simulated total hemoglobin, and simulated O2 saturation. Second, a dual-layer phantom was constructed to assess depth sensitivity, and the thickness of the superficial layer was varied. With a superficial layer thickness of 1, 2, 3, and 4 cm (μa = 0.149 cm(-1)), the proportional contribution of the deep layer (μa = 0.250 cm(-1)) to total μa was 80.1, 26.9, 3.7, and 0.0%, respectively (at 6-cm OS), validating penetration to ∼3 cm. Implementation of an additional superficial phantom to simulate adipose tissue further reduced depth sensitivity. Finally, superficial and deep muscle spectroscopy was performed in six participants during heavy-intensity cycle exercise. Compared with the superficial rectus femoris, peak deoxygenation of the deep rectus femoris (including the superficial intermedius in some) was not significantly different (deoxyhemoglobin and deoxymyoglobin concentration: 81.3 ± 20.8 vs. 78.3 ± 13.6 μM, P > 0.05), but deoxygenation kinetics were significantly slower (mean response time: 37 ± 10 vs. 65 ± 9 s, P ≤ 0.05). These data validate a high-power, time-resolved, near-infrared spectroscopy system with large OS for measuring the deoxygenation of deep tissues and reveal temporal and spatial disparities in muscle deoxygenation responses to exercise. Copyright © 2015 the American Physiological Society.

  7. Investigations of vertical chemical gradients in Cu(In,Ga)S{sub 2}-thin films prepared by sulfurization of sputtered precursor layers using highly spatially resolved cathodoluminescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ribbe, Stefan; Mueller, Mathias; Bertram, Frank; Hempel, Thomas; Christen, Juergen [Institute for Experimental Physics, Otto-von-Guericke-University Magdeburg (Germany); Rodriguez-Alvarez, Humberto; Lauche, Jakob; Schock, Hans-Werner [Helmholtz Center Berlin for Materials and Energy (Germany)

    2012-07-01

    The luminescence properties of Cu(In,Ga)S{sub 2}(CIGS)-absorber layers for thin film solar cells have been studied by highly spatially resolved cathodoluminescence (CL) at low temperature (T=5 K). In/Cu-Ga-precursors were annealed with elementary sulfur pellets in a rapid thermal process at different annealing times to represent different growth steps of the CIGS absorber layer. Spatially integral CL spectra show a dominant peak at 825 nm accompanied by a low-energy shoulder at 890 nm. Only a slight blue shift of the main peak is observed by variation of the excitation density. Investigations of cross-sections show for all samples a similar luminescence distribution. Near the molybdenum back contact distinct areas show luminescence emitting at 680-750 nm. In contrast, in upper regions of the layer a homogeneous low-energy luminescence at around 820 nm is observed which exhibits the most intensive spots on the cross-section. In local spectra we observe a change of the dominant recombination channel at the interface of these two regions.

  8. High-repetition-rate setup for pump-probe time-resolved XUV-IR experiments employing ion and electron momentum imaging

    Science.gov (United States)

    Pathak, Shashank; Robatjazi, Seyyed Javad; Wright Lee, Pearson; Raju Pandiri, Kanaka; Rolles, Daniel; Rudenko, Artem

    2017-04-01

    J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan KS, USA We report on the development of a versatile experimental setup for XUV-IR pump-probe experiments using a 10 kHz high-harmonic generation (HHG) source and two different charged-particle momentum imaging spectrometers. The HHG source, based on a commercial KM Labs eXtreme Ultraviolet Ultrafast Source, is capable of delivering XUV radiation of less than 30 fs pulse duration in the photon energy range of 17 eV to 100 eV. It can be coupled either to a conventional velocity map imaging (VMI) setup with an atomic, molecular, or nanoparticle target; or to a novel double-sided VMI spectrometer equipped with two delay-line detectors for coincidence studies. An overview of the setup and results of first pump-probe experiments including studies of two-color double ionization of Xe and time-resolved dynamics of photoionized CO2 molecule will be presented. This project is supported in part by National Science Foundation (NSF-EPSCOR) Award No. IIA-1430493 and in part by the Chemical science, Geosciences, and Bio-Science division, Office of Basic Energy Science, Office of science, U.S. Department of Energy. K.

  9. Smart design to resolve spectral overlapping of phosphor-in-glass for high-powered remote-type white light-emitting devices.

    Science.gov (United States)

    Lee, Jin Seok; Arunkumar, P; Kim, Sunghoon; Lee, In Jae; Lee, Hyungeui; Im, Won Bin

    2014-02-15

    The white light-emitting diode (WLED) is a state-of-the-art solid state technology, which has replaced conventional lighting systems due to its reduced energy consumption, its reliability, and long life. However, the WLED presents acute challenges in device engineering, due to its lack of color purity, efficacy, and thermal stability of the lighting devices. The prime cause for inadequacies in color purity and luminous efficiency is the spectral overlapping of red components with yellow/green emissions when generating white light by pumping a blue InGaN chip with yellow YAG:Ce³⁺ phosphor, where red phosphor is included, to compensate for deficiencies in the red region. An innovative strategy was formulated to resolve this spectral overlapping by alternatively arranging phosphor-in-glass (PiG) through cutting and reassembling the commercial red CaAlSiN₃:Eu²⁺ and green Lu₃Al₅O₁₂:Ce³⁺ PiG. PiGs were fabricated using glass frits with a low softening temperature of 600°C, which exhibited excellent thermal stability and high transparency, improving life time even at an operating temperature of 200°C. This strategy overcomes the spectral overlapping issue more efficiently than the randomly mixed and patented stacking design of multiple phosphors for a remote-type WLED. The protocol for the current design of PiG possesses excellent thermal and chemical stability with high luminous efficiency and color purity is an attempt to make smarter solid state lighting for high-powered remote-type white light-emitting devices.

  10. Feasibility of performing high resolution cloud-resolving simulations of historic extreme events: The San Fruttuoso (Liguria, italy) case of 1915.

    Science.gov (United States)

    Parodi, Antonio; Boni, Giorgio; Ferraris, Luca; Gallus, William; Maugeri, Maurizio; Molini, Luca; Siccardi, Franco

    2017-04-01

    Recent studies show that highly localized and persistent back-building mesoscale convective systems represent one of the most dangerous flash-flood producing storms in the north-western Mediterranean area. Substantial warming of the Mediterranean Sea in recent decades raises concerns over possible increases in frequency or intensity of these types of events as increased atmospheric temperatures generally support increases in water vapor content. Analyses of available historical records do not provide a univocal answer, since these may be likely affected by a lack of detailed observations for older events. In the present study, 20th Century Reanalysis Project initial and boundary condition data in ensemble mode are used to address the feasibility of performing cloud-resolving simulations with 1 km horizontal grid spacing of a historic extreme event that occurred over Liguria (Italy): The San Fruttuoso case of 1915. The proposed approach focuses on the ensemble Weather Research and Forecasting (WRF) model runs, as they are the ones most likely to best simulate the event. It is found that these WRF runs generally do show wind and precipitation fields that are consistent with the occurrence of highly localized and persistent back-building mesoscale convective systems, although precipitation peak amounts are underestimated. Systematic small north-westward position errors with regard to the heaviest rain and strongest convergence areas imply that the Reanalysis members may not be adequately representing the amount of cool air over the Po Plain outflowing into the Liguria Sea through the Apennines gap. Regarding the role of historical data sources, this study shows that in addition to Reanalysis products, unconventional data, such as historical meteorological bulletins, newspapers and even photographs can be very valuable sources of knowledge in the reconstruction of past extreme events.

  11. High time-resolved elemental components in fine and coarse particles in the Pearl River Delta region of Southern China: Dynamic variations and effects of meteorology.

    Science.gov (United States)

    Zhou, Shengzhen; Davy, Perry K; Wang, Xuemei; Cohen, Jason Blake; Liang, Jiaquan; Huang, Minjuan; Fan, Qi; Chen, Weihua; Chang, Ming; Ancelet, Travis; Trompetter, William J

    2016-12-01

    Hourly-resolved PM 2.5 and PM 10-2.5 samples were collected in the industrial city Foshan in the Pearl River Delta region, China. The samples were subsequently analyzed for elemental components and black carbon (BC). A key purpose of the study was to understand the composition of particulate matter (PM) at high-time resolution in a polluted urban atmosphere to identify key components contributing to extreme PM concentration events and examine the diurnal chemical concentration patterns for air quality management purposes. It was found that BC and S concentrations dominated in the fine mode, while elements with mostly crustal and oceanic origins such as Si, Ca, Al and Cl were found in the coarse size fraction. Most of the elements showed strong diurnal variations. S did not show clear diurnal variations, suggesting regional rather than local origin. Based on empirical orthogonal functions (EOF) method, 3 forcing factors were identified contributing to the extreme events of PM 2.5 and selected elements, i.e., urban direct emissions, wet deposition and a combination of coarse mode sources. Conditional probability functions (CPF) were performed using wind profiles and elemental concentrations. The CPF results showed that BC and elemental Cl, K, Fe, Cu and Zn in the fine mode were mostly from the northwest, indicating that industrial emissions and combustion were the main sources. For elements in the coarse mode, Si, Al, K, Ca, Fe and Ti showed similar patterns, suggesting same sources such as local soil dust/construction activities. Coarse elemental Cl was mostly from the south and southeast, implying the influence of marine aerosol sources. For other trace elements, we found vanadium (V) in fine PM was mainly from the sources located to the southeast of the measuring site. Combined with CPF results of S and V in fine PM, we concluded shipping emissions were likely an important elemental emission source. Copyright © 2016. Published by Elsevier B.V.

  12. High spatial resolution and temporally resolved T2* mapping of normal human myocardium at 7.0 Tesla: an ultrahigh field magnetic resonance feasibility study.

    Directory of Open Access Journals (Sweden)

    Fabian Hezel

    Full Text Available Myocardial tissue characterization using T(2(* relaxation mapping techniques is an emerging application of (preclinical cardiovascular magnetic resonance imaging. The increase in microscopic susceptibility at higher magnetic field strengths renders myocardial T(2(* mapping at ultrahigh magnetic fields conceptually appealing. This work demonstrates the feasibility of myocardial T(2(* imaging at 7.0 T and examines the applicability of temporally-resolved and high spatial resolution myocardial T(2(* mapping. In phantom experiments single cardiac phase and dynamic (CINE gradient echo imaging techniques provided similar T(2(* maps. In vivo studies showed that the peak-to-peak B(0 difference following volume selective shimming was reduced to approximately 80 Hz for the four chamber view and mid-ventricular short axis view of the heart and to 65 Hz for the left ventricle. No severe susceptibility artifacts were detected in the septum and in the lateral wall for T(2(* weighting ranging from TE = 2.04 ms to TE = 10.2 ms. For TE >7 ms, a susceptibility weighting induced signal void was observed within the anterior and inferior myocardial segments. The longest T(2(* values were found for anterior (T(2(* = 14.0 ms, anteroseptal (T(2(* = 17.2 ms and inferoseptal (T(2(* = 16.5 ms myocardial segments. Shorter T(2(* values were observed for inferior (T(2(* = 10.6 ms and inferolateral (T(2(* = 11.4 ms segments. A significant difference (p = 0.002 in T(2(* values was observed between end-diastole and end-systole with T(2(* changes of up to approximately 27% over the cardiac cycle which were pronounced in the septum. To conclude, these results underscore the challenges of myocardial T(2(* mapping at 7.0 T but demonstrate that these issues can be offset by using tailored shimming techniques and dedicated acquisition schemes.

  13. Novel Insight for Organic Matter Sourcing: Interest of Time Resolved Fluorescence to Qualify and Quantify PAH Content of Solid Matrix at High Resolution

    Science.gov (United States)

    Quiers, M.; Perrette, Y.; Jacq, K.; Pousset, E.; Plassart, G.

    2017-12-01

    OM fluorescence is today a well-developed tool used to characterize and quantify organic matter (OM), but also to evaluate and discriminate OM fate and changes related to climate and environmental modifications. While fluorescence measurements on water and soils extracts provide information about organic fluxes today, solid phase fluorescence using natural archives allows to obtain high resolution records of OM evolution during time. These evolutions can be discussed in regards of climate and environmental perturbations detected in archives using different proxies, and thus provide keys for understanding factors driving carbon fluxes mechanisms. Among fluorescent organic species, Polycyclic Aromatic Hydrocarbons (PAH) have been used as probe molecules for organic contamination tracking. Moreover, monitoring studies have shown that PAH could also be used as markers to discriminates atmospheric and erosion factors leading to PAH and organic matter fluxes to the aquifer. PAH records in soils and natural archives appear as a promising proxy to follow both past atmospheric contamination and soil erosion. But, PAH fluorescence is difficult to discriminate from bulk OM fluorescence using steady-state fluorescence (SSF) technics as their fluorescence domains recover. Time resolved emission spectroscopy (TRES) increases the information provided by SSF technic, adding a time dimension to measurements and allowing to discriminate PAH fluorescence. We report here a first application of this technic on natural archives. The challenge is to obtain TRES signature along the sample, including for low PAH concentrations. This study aims to evaluate the reliability of high resolution TRES measurement as PAH carbon fluxes sources. Method is based on LIF instrument for solid phase fluorescence measurement. An instrument coupling an excitation system constituting by 2 pulsed lasers (266 and 355 nm) and a detection system was developed. This measurement provides high resolution record of

  14. Direct determination of highly size-resolved turbulent particle fluxes with the disjunct eddy covariance method and a 12 – stage electrical low pressure impactor

    Directory of Open Access Journals (Sweden)

    A. Schmidt

    2008-12-01

    Full Text Available During summer 2007, turbulent vertical particle mass and number fluxes were measured for a period of 98 days near the city centre of Münster in north-west Germany. For this purpose, a valve controlled disjunct eddy covariance system was mounted at 65 m a.g.l. on a military radio tower. The concentration values for 11 size bins with aerodynamic diameters (D50 from 0.03 to 10 μm were measured with an electrical low pressure impactor. After comparison with other fluxes obtained from 10 Hz measurements with the classical eddy covariance method, the loss of information concerning high frequent parts of the flux could be stated as negligible. The results offer an extended insight in the turbulent atmospheric exchange of aerosol particles by highly size-resolved particle fluxes covering 11 size bins and show that the city of Münster acts as a relevant source for aerosol particles.

    Significant differences occur between the fluxes of the various particle size classes. While the total particle number flux shows a pattern which is strictly correlated to the diurnal course of the turbulence regime and the traffic intensity, the total mass flux exhibits a single minimum in the evening hours when coarse particles start to deposit.

    As a result, a mean mass deposition of about 10 mg m−2 per day was found above the urban test site, covering the aerosol size range from 40 nm to 2.0 μm. By contrast, the half-hourly total number fluxes accumulated over the lower ELPI stages range from −4.29×107 to +1.44×108 particles m−2 s−1 and are clearly dominated by the sub-micron particle fraction of the impactor stages with diameters between 40 nm and 320 nm. The averaged number fluxes of particles with diameters between 2.0 and 6.4 μm show lower turbulent dynamics during daytime and partially remarkably high negative fluxes with mean deposition velocities of 2×10−3 m

  15. Seasonal Variations of High Time-Resolved Chemical Compositions, Sources and Evolution for Atmospheric Submicron Aerosols in the Megacity of Beijing

    Science.gov (United States)

    Hu, Min; Hu, Wei; Hu, Weiwei; Zheng, Jing; Guo, Song; Wu, Yusheng; Lu, Sihua; Zeng, Limin

    2016-04-01

    This study aims to investigate aerosol secondary formation and aging process in the megacity of Beijing. Seasonal intensive campaigns were conducted from March 2012 to March 2013 at an urban site located at the campus of Peking University (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and other relevant instrumentations for gaseous and particulate pollutants were deployed. The average submicron aerosol (PM1) mass concentrations were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7 and 81.7 ± 72.4 μg m-3 in spring, summer, autumn and winter, respectively. Organic matter was the most abundant component, accounting for 31%, 33%, 44% and 36% in PM1 correspondingly, followed by sulfate and nitrate. Distinct seasonal and diurnal patterns of the components of PM1 tracking primary sources (e.g., BC and HOA) and secondary formation (e.g., sulfate, nitrate, ammonium, LV-OOA and SV-OOA) were significantly influenced by primary emissions and mesoscale meteorology. Combining positive matrix factorization (PMF) analysis with the mass spectrometry of organics measured by AMS, the contributions of primary and secondary sources to submicron organic aerosols (OA) were apportioned. In spring and summer, the primary sources were hydrocarbon-like OA (HOA) and cooking OA (COA), and the secondary components were low volatility (LV-OOA) and semi-volatile oxygenated OA (SV-OOA). In winter biomass burning OA (BBOA) was also resolved. In autumn, four factors were resolved, that is, OOA, HOA, COA and BBOA. In general, OOA (sum of LV-OOA and SV-OOA) was important in OA in four seasons, accounting for about 63%, 70%, 47% and 50%, respectively. SV-OOA dominated OA in summer (44%) due to the fresh secondary formation from strong photochemical oxidations; whereas, LV-OOA was dominant in OA in winter (33%), maybe because the transported air masses were more aged in heavily polluted days. The POA (sum of HOA, COA and BBOA) in OA was dominant in

  16. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-09-01

    Full Text Available As part of Campaigns of Air Quality Research in Beijing and Surrounding Region-2008 (CAREBeijing-2008, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralympic Games (24 July to 20 September 2008. The campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m−3; the mean composition consisted of organics (37.9%, sulfate (26.7%, ammonium (15.9%, nitrate (15.8%, black carbon (3.1%, and chloride (0.87%. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA, cooking-related (COA, and two oxygenated organic aerosols (OOA-1 and OOA-2, which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum and diurnal pattern showed similar characteristics to that measured for cooking emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. Aerosol particles in southern airmasses were especially rich in inorganic and oxidized organic species. Aerosol particles in northern airmasses

  17. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Science.gov (United States)

    Huang, X.-F.; He, L.-Y.; Hu, M.; Canagaratna, M. R.; Sun, Y.; Zhang, Q.; Zhu, T.; Xue, L.; Zeng, L.-W.; Liu, X.-G.; Zhang, Y.-H.; Jayne, J. T.; Ng, N. L.; Worsnop, D. R.

    2010-09-01

    As part of Campaigns of Air Quality Research in Beijing and Surrounding Region-2008 (CAREBeijing-2008), an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralympic Games (24 July to 20 September 2008). The campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m-3; the mean composition consisted of organics (37.9%), sulfate (26.7%), ammonium (15.9%), nitrate (15.8%), black carbon (3.1%), and chloride (0.87%). The average size distributions of the species (except BC) were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF) analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA), cooking-related (COA), and two oxygenated organic aerosols (OOA-1 and OOA-2), which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum and diurnal pattern showed similar characteristics to that measured for cooking emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C) compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. Aerosol particles in southern airmasses were especially rich in inorganic and oxidized organic species. Aerosol particles in northern airmasses contained a large fraction of primary HOA

  18. Highly time-resolved urban aerosol characteristics during springtime in Yangtze River Delta, China: insights from soot particle aerosol mass spectrometry

    Science.gov (United States)

    Wang, Junfeng; Ge, Xinlei; Chen, Yanfang; Shen, Yafei; Zhang, Qi; Sun, Yele; Xu, Jianzhong; Ge, Shun; Yu, Huan; Chen, Mindong

    2016-07-01

    In this work, the Aerodyne soot particle - aerosol mass spectrometer (SP-AMS) was deployed for the first time during the spring of 2015 in urban Nanjing, a megacity in the Yangtze River Delta (YRD) of China, for online characterization of the submicron aerosols (PM1). The SP-AMS enables real-time and fast quantification of refractory black carbon (rBC) simultaneously with other non-refractory species (ammonium, sulfate, nitrate, chloride, and organics). The average PM1 concentration was found to be 28.2 µg m-3, with organics (45 %) as the most abundant component, following by sulfate (19.3 %), nitrate (13.6 %), ammonium (11.1 %), rBC (9.7 %), and chloride (1.3 %). These PM1 species together can reconstruct ˜ 44 % of the light extinction during this campaign based on the IMPROVE method. Chemically resolved mass-based size distributions revealed that small particles especially ultrafine ones (cooking-related OA (COA), semi-volatile oxygenated OA (SV-OOA), and low-volatility oxygenated OA (LV-OOA). Overall, secondary organic aerosol (SOA, equal to the sum of SV-OOA and LV-OOA) dominated the total OA mass (55.5 %), but primary organic aerosol (POA, equal to the sum of HOA and COA) can outweigh SOA in the early morning and evening due to enhanced human activities. High OA concentrations were often associated with high mass fractions of POA and rBC, indicating the important role of anthropogenic emissions during heavy pollution events. The diurnal cycles of nitrate, chloride, and SV-OOA both showed good anti-correlations with air temperatures, suggesting their variations were likely driven by thermodynamic equilibria and gas-to-particle partitioning. On the other hand, in contrast to other species, sulfate, and LV-OOA concentrations increased in the afternoon, and showed no positive correlations with relative humidity (RH), likely indicating the contribution from photochemical oxidation is dominant over that of aqueous-phase processing for their formations. The

  19. Simultaneous characterization of elemental segregation and cementite networks in high carbon steel products by spatially-resolved laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Boué-Bigne, Fabienne, E-mail: fabienne.boue-bigne@tatasteel.com

    2014-06-01

    The reliable characterization of the level of elemental segregation and of the extent of grain-boundary cementite networks in high carbon steel products is a prerequisite for checking product quality, for the purpose of product release to customers, and to investigate the presence of defects that may have led to mechanical property failure of the product. Current methods for the characterization of segregation and cementite networks rely on two different methods of sample etching followed by visual observation, where quality scores are given based on human perception and judgment. With the continuous demand on increasing quality, some of the conventional characterization methods and their associated scoring boards have lost relevance for the precision of characterization that is required today to distinguish between a product that will perform well and one that will not. In order to move away from a qualitative, human perception based situation for the scoring of the severity of segregation and cementite networks, a new method of data evaluation based on spatially-resolved LIBS measurements was developed to provide quantitative and simultaneous characterization of both types of defects. The quantitative assessment of segregation and cementite networks is based on the acquisition of carbon concentration maps. The ability to produce rapid scanning measurements of micro and macro-scale features with adequate spatial resolution makes LIBS the measurement method of preference for this purpose. The characterization of both different defects is extracted simultaneously and from the same carbon concentration map following a series of statistical treatment and data extraction rules. LIBS results were validated against recognized methods and were applied to a significant number of routine samples. The new LIBS method offers a step change improvement in reliability for the characterization of segregation and cementite networks in steel products over the conventional methods

  20. ChromAIX2: A large area, high count-rate energy-resolving photon counting ASIC for a Spectral CT Prototype

    Science.gov (United States)

    Steadman, Roger; Herrmann, Christoph; Livne, Amir

    2017-08-01

    Spectral CT based on energy-resolving photon counting detectors is expected to deliver additional diagnostic value at a lower dose than current state-of-the-art CT [1]. The capability of simultaneously providing a number of spectrally distinct measurements not only allows distinguishing between photo-electric and Compton interactions but also discriminating contrast agents that exhibit a K-edge discontinuity in the absorption spectrum, referred to as K-edge Imaging [2]. Such detectors are based on direct converting sensors (e.g. CdTe or CdZnTe) and high-rate photon counting electronics. To support the development of Spectral CT and show the feasibility of obtaining rates exceeding 10 Mcps/pixel (Poissonian observed count-rate), the ChromAIX ASIC has been previously reported showing 13.5 Mcps/pixel (150 Mcps/mm2 incident) [3]. The ChromAIX has been improved to offer the possibility of a large area coverage detector, and increased overall performance. The new ASIC is called ChromAIX2, and delivers count-rates exceeding 15 Mcps/pixel with an rms-noise performance of approximately 260 e-. It has an isotropic pixel pitch of 500 μm in an array of 22×32 pixels and is tile-able on three of its sides. The pixel topology consists of a two stage amplifier (CSA and Shaper) and a number of test features allowing to thoroughly characterize the ASIC without a sensor. A total of 5 independent thresholds are also available within each pixel, allowing to acquire 5 spectrally distinct measurements simultaneously. The ASIC also incorporates a baseline restorer to eliminate excess currents induced by the sensor (e.g. dark current and low frequency drifts) which would otherwise cause an energy estimation error. In this paper we report on the inherent electrical performance of the ChromAXI2 as well as measurements obtained with CZT (CdZnTe)/CdTe sensors and X-rays and radioactive sources.

  1. Transient analysis for resolving safety issues

    International Nuclear Information System (INIS)

    Chao, J.; Layman, W.

    1987-01-01

    The Nuclear Safety Analysis Center (NSAC) has a Generic Safety Analysis Program to help resolve high priority generic safety issues. This paper describes several high priority safety issues considered at NSAC and how they were resolved by transient analysis using thermal hydraulics and neutronics codes. These issues are pressurized thermal shock (PTS), anticipated transients without scram (ATWS), steam generator tube rupture (SGTR), and reactivity transients in light of the Chernobyl accident

  2. Operation: Inherent Resolve

    DEFF Research Database (Denmark)

    Cramer-Larsen, Lars

    2015-01-01

    Kapitlet giver læseren indsigt i den internationale koalitions engagement mod IS igennem Operaton Inherent Resolve; herunder koalitionens strategi i forhold til IS strategi, ligesom det belyser kampagnens legalitet og folkeretlige grundlag, ligesom det giver et bud på overvejelser om kampagnens...

  3. Novel Super-Resolution Approach to Time-Resolved Volumetric 4-Dimensional Magnetic Resonance Imaging With High Spatiotemporal Resolution for Multi-Breathing Cycle Motion Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guang, E-mail: lig2@mskcc.org [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Wei, Jie [Department of Computer Science, City College of New York, New York, New York (United States); Kadbi, Mo [Philips Healthcare, MR Therapy Cleveland, Ohio (United States); Moody, Jason; Sun, August; Zhang, Shirong; Markova, Svetlana; Zakian, Kristen; Hunt, Margie; Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2017-06-01

    Purpose: To develop and evaluate a super-resolution approach to reconstruct time-resolved 4-dimensional magnetic resonance imaging (TR-4DMRI) with a high spatiotemporal resolution for multi-breathing cycle motion assessment. Methods and Materials: A super-resolution approach was developed to combine fast 3-dimensional (3D) cine MRI with low resolution during free breathing (FB) and high-resolution 3D static MRI during breath hold (BH) using deformable image registration. A T1-weighted, turbo field echo sequence, coronal 3D cine acquisition, partial Fourier approximation, and SENSitivity Encoding parallel acceleration were used. The same MRI pulse sequence, field of view, and acceleration techniques were applied in both FB and BH acquisitions; the intensity-based Demons deformable image registration method was used. Under an institutional review board–approved protocol, 7 volunteers were studied with 3D cine FB scan (voxel size: 5 × 5 × 5 mm{sup 3}) at 2 Hz for 40 seconds and a 3D static BH scan (2 × 2 × 2 mm{sup 3}). To examine the image fidelity of 3D cine and super-resolution TR-4DMRI, a mobile gel phantom with multi-internal targets was scanned at 3 speeds and compared with the 3D static image. Image similarity among 3D cine, 4DMRI, and 3D static was evaluated visually using difference image and quantitatively using voxel intensity correlation and Dice index (phantom only). Multi-breathing-cycle waveforms were extracted and compared in both phantom and volunteer images using the 3D cine as the references. Results: Mild imaging artifacts were found in the 3D cine and TR-4DMRI of the mobile gel phantom with a Dice index of >0.95. Among 7 volunteers, the super-resolution TR-4DMRI yielded high voxel-intensity correlation (0.92 ± 0.05) and low voxel-intensity difference (<0.05). The detected motion differences between TR-4DMRI and 3D cine were −0.2 ± 0.5 mm (phantom) and −0.2 ± 1.9 mm (diaphragms). Conclusion: Super-resolution TR-4

  4. Novel Super-Resolution Approach to Time-Resolved Volumetric 4-Dimensional Magnetic Resonance Imaging With High Spatiotemporal Resolution for Multi-Breathing Cycle Motion Assessment

    International Nuclear Information System (INIS)

    Li, Guang; Wei, Jie; Kadbi, Mo; Moody, Jason; Sun, August; Zhang, Shirong; Markova, Svetlana; Zakian, Kristen; Hunt, Margie; Deasy, Joseph O.

    2017-01-01

    Purpose: To develop and evaluate a super-resolution approach to reconstruct time-resolved 4-dimensional magnetic resonance imaging (TR-4DMRI) with a high spatiotemporal resolution for multi-breathing cycle motion assessment. Methods and Materials: A super-resolution approach was developed to combine fast 3-dimensional (3D) cine MRI with low resolution during free breathing (FB) and high-resolution 3D static MRI during breath hold (BH) using deformable image registration. A T1-weighted, turbo field echo sequence, coronal 3D cine acquisition, partial Fourier approximation, and SENSitivity Encoding parallel acceleration were used. The same MRI pulse sequence, field of view, and acceleration techniques were applied in both FB and BH acquisitions; the intensity-based Demons deformable image registration method was used. Under an institutional review board–approved protocol, 7 volunteers were studied with 3D cine FB scan (voxel size: 5 × 5 × 5 mm"3) at 2 Hz for 40 seconds and a 3D static BH scan (2 × 2 × 2 mm"3). To examine the image fidelity of 3D cine and super-resolution TR-4DMRI, a mobile gel phantom with multi-internal targets was scanned at 3 speeds and compared with the 3D static image. Image similarity among 3D cine, 4DMRI, and 3D static was evaluated visually using difference image and quantitatively using voxel intensity correlation and Dice index (phantom only). Multi-breathing-cycle waveforms were extracted and compared in both phantom and volunteer images using the 3D cine as the references. Results: Mild imaging artifacts were found in the 3D cine and TR-4DMRI of the mobile gel phantom with a Dice index of >0.95. Among 7 volunteers, the super-resolution TR-4DMRI yielded high voxel-intensity correlation (0.92 ± 0.05) and low voxel-intensity difference (<0.05). The detected motion differences between TR-4DMRI and 3D cine were −0.2 ± 0.5 mm (phantom) and −0.2 ± 1.9 mm (diaphragms). Conclusion: Super-resolution TR-4DMRI has been

  5. Determining the nature of excitonic dephasing in high-quality GaN/AlGaN quantum wells through time-resolved and spectrally resolved four-wave mixing spectroscopy

    Science.gov (United States)

    Gallart, M.; Ziegler, M.; Crégut, O.; Feltin, E.; Carlin, J.-F.; Butté, R.; Grandjean, N.; Hönerlage, B.; Gilliot, P.

    2017-07-01

    Applying four-wave mixing spectroscopy to a high-quality GaN/AlGaN single quantum well, we report on the experimental determination of excitonic dephasing times at different temperatures and exciton densities in III-nitride heterostructures. By comparing the evolution with the temperature of the dephasing and the spin-relaxation rate, we conclude that both processes are related to the rate of excitonic collisions. When spin relaxation occurs in the motional-narrowing regime, it remains constant over a large temperature range as the spin-precession frequency increases linearly with temperature, hence compensating for the observed decrease in the dephasing time. From those measurements, a value of the electron-hole exchange interaction strength of 0.45 meV at T =10 K is inferred.

  6. Highly time-resolved urban aerosol characteristics during springtime in Yangtze River Delta, China: insights from soot particle aerosol mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Wang

    2016-07-01

    Full Text Available In this work, the Aerodyne soot particle – aerosol mass spectrometer (SP-AMS was deployed for the first time during the spring of 2015 in urban Nanjing, a megacity in the Yangtze River Delta (YRD of China, for online characterization of the submicron aerosols (PM1. The SP-AMS enables real-time and fast quantification of refractory black carbon (rBC simultaneously with other non-refractory species (ammonium, sulfate, nitrate, chloride, and organics. The average PM1 concentration was found to be 28.2 µg m−3, with organics (45 % as the most abundant component, following by sulfate (19.3 %, nitrate (13.6 %, ammonium (11.1 %, rBC (9.7 %, and chloride (1.3 %. These PM1 species together can reconstruct ∼ 44 % of the light extinction during this campaign based on the IMPROVE method. Chemically resolved mass-based size distributions revealed that small particles especially ultrafine ones (< 100 nm vacuum aerodynamic diameter were dominated by organics and rBC, while large particles had significant contributions from secondary inorganic species. Source apportionment of organic aerosols (OA yielded four OA subcomponents, including hydrocarbon-like OA (HOA, cooking-related OA (COA, semi-volatile oxygenated OA (SV-OOA, and low-volatility oxygenated OA (LV-OOA. Overall, secondary organic aerosol (SOA, equal to the sum of SV-OOA and LV-OOA dominated the total OA mass (55.5 %, but primary organic aerosol (POA, equal to the sum of HOA and COA can outweigh SOA in the early morning and evening due to enhanced human activities. High OA concentrations were often associated with high mass fractions of POA and rBC, indicating the important role of anthropogenic emissions during heavy pollution events. The diurnal cycles of nitrate, chloride, and SV-OOA both showed good anti-correlations with air temperatures, suggesting their variations were likely driven by thermodynamic equilibria and gas-to-particle partitioning. On the other hand

  7. Identification of the high pt jet events produced by a resolved photon at HERA and reconstruction of the initial state parton kinematics

    International Nuclear Information System (INIS)

    D'Agostini, G.; Monaldi, D.

    1992-01-01

    We have studied the possibility offered by the HERA detectors to identify the events where a proton interacts with a parton of the (quasi) real photon. We find that the presence of hadronic fragments of the photon outside of the beam pipe allows the identification of the two jet events produced by a resolved photon, with good efficiency and low background from the direct photon events. We show that it is also possible to reconstruct the fractional momenta of the two incoming partons. (orig.)

  8. When combined X-ray and polarized neutron diffraction data challenge high-level calculations: spin-resolved electron density of an organic radical.

    Science.gov (United States)

    Voufack, Ariste Bolivard; Claiser, Nicolas; Lecomte, Claude; Pillet, Sébastien; Pontillon, Yves; Gillon, Béatrice; Yan, Zeyin; Gillet, Jean Michel; Marazzi, Marco; Genoni, Alessandro; Souhassou, Mohamed

    2017-08-01

    Joint refinement of X-ray and polarized neutron diffraction data has been carried out in order to determine charge and spin density distributions simultaneously in the nitronyl nitroxide (NN) free radical Nit(SMe)Ph. For comparison purposes, density functional theory (DFT) and complete active-space self-consistent field (CASSCF) theoretical calculations were also performed. Experimentally derived charge and spin densities show significant differences between the two NO groups of the NN function that are not observed from DFT theoretical calculations. On the contrary, CASSCF calculations exhibit the same fine details as observed in spin-resolved joint refinement and a clear asymmetry between the two NO groups.

  9. Time-Resolved Analysis of a Highly Sensitive Förster Resonance Energy Transfer Immunoassay Using Terbium Complexes as Donors and Quantum Dots as Acceptors

    Directory of Open Access Journals (Sweden)

    Niko Hildebrandt

    2007-01-01

    Full Text Available CdSe/ZnS core/shell quantum dots (QDs are used as efficient Förster Resonance Energy Transfer (FRET acceptors in a time-resolved immunoassays with Tb complexes as donors providing a long-lived luminescence decay. A detailed decay time analysis of the FRET process is presented. QD FRET sensitization is evidenced by a more than 1000-fold increase of the QD luminescence decay time reaching ca. 0.5 milliseconds, the same value to which the Tb donor decay time is quenched due to FRET to the QD acceptors. The FRET system has an extremely large Förster radius of approx. 100 Å and more than 70% FRET efficiency with a mean donor-acceptor distance of ca. 84 Å, confirming the applied biotin-streptavidin binding system. Time-resolved measurement allows for suppression of short-lived emission due to background fluorescence and directly excited QDs. By this means a detection limit of 18 attomol QDs within the immunoassay is accomplished, an improvement of more than two orders of magnitude compared to commercial systems.

  10. Time-resolved absorption measurements on OMEGA

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; DaSilva, L.; Delettrez, J.; Gregory, G.G.; Richardson, M.C.

    1986-01-01

    Time-resolved measurements of the incident laser light that is scattered and/or refracted from targets irradiated by the 24 uv-beam OMEGA laser at LLE, have provided some interesting features related to time-resolved absorption. The decrease in laser absorption characteristic of irradiating a target that implodes during the laser pulse has been observed. The increase in absorption expected as the critical density surface moves from a low to a high Z material in the target has also been noted. The detailed interpretation of these results is made through comparisons with simulation using the code LILAC, as well as with streak data from time-resolved x-ray imaging and spectroscopy. In addition, time and space-resolved imaging of the scattered light yields information on laser irradiation uniformity conditions on the target. The report consists of viewgraphs

  11. Bulk electronic structures of n-type superconductor Nd1.85Ce0.15CuO4 probed by high energy angle-resolved photoemission spectroscopy

    International Nuclear Information System (INIS)

    Tsunekawa, M.; Sekiyama, A.; Kasai, S.; Yamasaki, A.; Fujiwara, H.; Sing, M.; Shigemoto, A.; Imada, S.; Onose, Y.; Tokura, Y.; Muro, T.; Suga, S.

    2005-01-01

    We report on a high-energy angle-resolved photoemission (ARPES) study of the n-type high-T C cuprate, Nd 1.85 Ce 0.15 CuO 4 (NCCO). Our bulk sensitive results suggest a hole-like Fermi surface as seen by the so far reported low-energy ARPES studies. The soft X-ray Cu 2p core-level photoemission spectra show clear polar-angle dependence, suggesting the difference in electron states between the bulk and surface

  12. Analysis of co-eluted isomers of high-molecular weight polycyclic aromatic hydrocarbons in high performance liquid chromatography fractions via solid-phase nanoextraction and time-resolved Shpol'skii spectroscopy.

    Science.gov (United States)

    Wilson, Walter B; Campiglia, Andres D

    2011-09-28

    We present an accurate method for the determination of isomers of high-molecular weight polycyclic aromatic hydrocarbons co-eluted in HPLC fractions. The feasibility of this approach is demonstrated with two isomers of molecular weight 302 with identical mass fragmentation patterns, namely dibenzo[a,i]pyrene and naphtho[2,3-a]pyrene. Qualitative and quantitative analysis is carried out via laser-excited time-resolved Shpol'skii spectroscopy at liquid helium temperature. Unambiguous identification of co-eluted isomers is based on their characteristic 4.2 K line-narrowed spectra in n-octane as well as their fluorescence lifetimes. Pre-concentration of HPLC fractions prior to spectroscopic analysis is performed with the aid of gold nanoparticles via an environmentally friendly procedure. In addition to the two co-eluted isomers, the analytical figures of merit of the entire procedure were evaluated with dibenzo[a,l]pyrene, dibenzo[a,h]pyrene and dibenzo[a,e]pyrene. The analytical recoveries from drinking water samples varied between 98.2±5.5 (dibenzo[a,l]pyrene) and 102.7±3.2% (dibenzo[a,i]pyrene). The limits of detection ranged from 51.1 ng L(-1) (naphtho[2,3-a]pyrene) to 154 ng L(-1) (dibenzo[a,e]pyrene). The excellent analytical figures of merit associated to its HPLC compatibility makes this approach an attractive alternative for the analysis of co-eluted isomers with identical mass spectra. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Statistics of strain rates and surface density function in a flame-resolved high-fidelity simulation of a turbulent premixed bluff body burner

    Science.gov (United States)

    Sandeep, Anurag; Proch, Fabian; Kempf, Andreas M.; Chakraborty, Nilanjan

    2018-06-01

    The statistical behavior of the surface density function (SDF, the magnitude of the reaction progress variable gradient) and the strain rates, which govern the evolution of the SDF, have been analyzed using a three-dimensional flame-resolved simulation database of a turbulent lean premixed methane-air flame in a bluff-body configuration. It has been found that the turbulence intensity increases with the distance from the burner, changing the flame curvature distribution and increasing the probability of the negative curvature in the downstream direction. The curvature dependences of dilatation rate ∇ṡu → and displacement speed Sd give rise to variations of these quantities in the axial direction. These variations affect the nature of the alignment between the progress variable gradient and the local principal strain rates, which in turn affects the mean flame normal strain rate, which assumes positive values close to the burner but increasingly becomes negative as the effect of turbulence increases with the axial distance from the burner exit. The axial distance dependences of the curvature and displacement speed also induce a considerable variation in the mean value of the curvature stretch. The axial distance dependences of the dilatation rate and flame normal strain rate govern the behavior of the flame tangential strain rate, and its mean value increases in the downstream direction. The current analysis indicates that the statistical behaviors of different strain rates and displacement speed and their curvature dependences need to be included in the modeling of flame surface density and scalar dissipation rate in order to accurately capture their local behaviors.

  14. Resolving inventory differences

    International Nuclear Information System (INIS)

    Weber, J.H.; Clark, J.P.

    1991-01-01

    Determining the cause of an inventory difference (ID) that exceeds warning or alarm limits should not only involve investigation into measurement methods and reexamination of the model assumptions used in the calculation of the limits, but also result in corrective actions that improve the quality of the accountability measurements. An example illustrating methods used by Savannah River Site (SRS) personnel to resolve an ID is presented that may be useful to other facilities faced with a similar problem. After first determining that no theft or diversion of material occurred and correcting any accountability calculation errors, investigation into the IDs focused on volume and analytical measurements, limit of error of inventory difference (LEID) modeling assumptions, and changes in the measurement procedures and methods prior to the alarm. There had been a gradual gain trend in IDs prior to the alarm which was reversed by the alarm inventory. The majority of the NM in the facility was stored in four large tanks which helped identify causes for the alarm. The investigation, while indicating no diversion or theft, resulted in changes in the analytical method and in improvements in the measurement and accountability that produced a 67% improvement in the LEID

  15. Time resolved investigations on flow field and quasi wall shear stress of an impingement configuration with pulsating jets by means of high speed PIV and a surface hot wire array

    International Nuclear Information System (INIS)

    Janetzke, Timm; Nitsche, Wolfgang

    2009-01-01

    The effects of jet pulsation on flow field and quasi wall shear stress of an impingement configuration were investigated experimentally. The excitation Strouhal number and amplitude were varied as the most influential parameters. A line-array with three submerged air jets, and a confining plate were used. The flow field analysis by means of time resolved particle image velocimetry shows that the controlled excitation can considerably affect the near-field flow of an impinging jet array. These effects are visualized as organization of the coherent flow structures. Augmentation of the Kelvin-Helmholtz vortices in the jet shear layer depends on the Strouhal number and pulsation magnitude and can be associated with pairing of small scale vortices in the jet. A total maximum of vortex strength was observed when exciting with Sr = 0.82 and coincident high amplitudes. Time resolved interaction between impinging vortices and impingement plate boundary layer due to jet excitation was verified by using an array of 5 μm surface hot wires. Corresponding to the global flow field modification due to periodic jet pulsation, the impact of the vortex rings on the wall boundary layer is highly influenced by the above mentioned excitation parameters and reaches a maximum at Sr = 0.82.

  16. Time-resolved studies

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

    When new or more powerful probes become available that offer both shorter data-collection times and the opportunity to apply innovative approaches to established techniques, it is natural that investigators consider the feasibility of exploring the kinetics of time-evolving systems. This stimulating area of research not only can lead to insights into the metastable or excited states that a system may populate on its way to a ground state, but can also lead to a better understanding of that final state. Synchrotron radiation, with its unique properties, offers just such a tool to extend X-ray measurements from the static to the time-resolved regime. The most straight-forward application of synchrotron radiation to the study of transient phenomena is directly through the possibility of decreased data-collection times via the enormous increase in flux over that of a laboratory X-ray system. Even further increases in intensity can be obtained through the use of novel X-ray optical devices. Widebandpass monochromators, e.g., that utilize the continuous spectral distribution of synchrotron radiation, can increase flux on the sample several orders of magnitude over conventional X-ray optical systems thereby allowing a further shortening of the data-collection time. Another approach that uses the continuous spectral nature of synchrotron radiation to decrease data-collection times is the open-quote parallel data collectionclose quotes method. Using this technique, intensities as a function of X-ray energy are recorded simultaneously for all energies rather than sequentially recording data at each energy, allowing for a dramatic decrease in the data-collection time

  17. Direct angle resolved photoemission spectroscopy and ...

    Indian Academy of Sciences (India)

    Since 1997 we systematically perform direct angle resolved photoemission spectroscopy (ARPES) on in-situ grown thin (< 30 nm) cuprate films. Specifically, we probe low-energy electronic structure and properties of high-c superconductors (HTSC) under different degrees of epitaxial (compressive vs. tensile) strain.

  18. A randomised comparison of Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion: rationale and design of the CIT-RESOLVE trial.

    Science.gov (United States)

    Zhang, Dong; Yin, Dong; Song, Chenxi; Zhu, Chengang; Kirtane, Ajay J; Xu, Bo; Dou, Kefei

    2017-06-12

    The intentional strategy (aggressive side branch (SB) protection strategy: elective two-stent strategy or jailed balloon technique) is thought to be associated with lower SB occlusion rate than conventional strategy (provisional two-stent strategy or jailed wire technique). However, most previous studies showed comparable outcomes between the two strategies, probably due to no risk classification of SB occlusion when enrolling patients. There is still no randomised trial compared the intentional and conventional strategy when treating bifurcation lesions with high risk of SB occlusion. We aim to investigate if intentional strategy is associated with significant reduction of SB occlusion rate compared with conventional strategy in high-risk patients. The Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion (CIT-RESOLVE) is a prospective, randomised, single-blind, multicentre clinical trial comparing the rate of SB occlusion between the intentional strategy group and the conventional strategy group (positive control group) in a consecutive cohort of patients with high risk of side branch occlusion defined by V-RESOLVE score, which is a validated angiographic scoring system to evaluate the risk of SB occlusion in bifurcation intervention and used as one of the inclusion criteria to select patients with high SB occlusion risk (V-RESOLVE score ≥12). A total of 21 hospitals from 10 provinces in China participated in the present study. 566 patients meeting all inclusion/exclusion criteria are randomised to either intentional strategy group or conventional strategy group. The primary endpoint is SB occlusion (defined as any decrease in thrombolysis in myocardial infarction flow grade or absence of flow in SB after main vessel stenting). All patients are followed up for 12-month postdischarge. The protocol has been approved by all local ethics committee. The ethics committee have

  19. Femtosecond time-resolved optical and Raman spectroscopy of photoinduced spin crossover: temporal resolution of low-to-high spin optical switching.

    Science.gov (United States)

    Smeigh, Amanda L; Creelman, Mark; Mathies, Richard A; McCusker, James K

    2008-10-29

    A combination of femtosecond electronic absorption and stimulated Raman spectroscopies has been employed to determine the kinetics associated with low-spin to high-spin conversion following charge-transfer excitation of a FeII spin-crossover system in solution. A time constant of tau = 190 +/- 50 fs for the formation of the 5T2 ligand-field state was assigned based on the establishment of two isosbestic points in the ultraviolet in conjunction with changes in ligand stretching frequencies and Raman scattering amplitudes; additional dynamics observed in both the electronic and vibrational spectra further indicate that vibrational relaxation in the high-spin state occurs with a time constant of ca. 10 ps. The results set an important precedent for extremely rapid, formally forbidden (DeltaS = 2) nonradiative relaxation as well as defining the time scale for intramolecular optical switching between two electronic states possessing vastly different spectroscopic, geometric, and magnetic properties.

  20. Monitoring of implanted stem cell migration in vivo: A highly resolved in vivo magnetic resonance imaging investigation of experimental stroke in rat

    Science.gov (United States)

    Hoehn, Mathias; Küstermann, Ekkehard; Blunk, James; Wiedermann, Dirk; Trapp, Thorsten; Wecker, Stefan; Föcking, Melanie; Arnold, Heinz; Hescheler, Jürgen; Fleischmann, Bernd K.; Schwindt, Wolfram; Bührle, Christian

    2002-01-01

    In vivo monitoring of stem cells after grafting is essential for a better understanding of their migrational dynamics and differentiation processes and of their regeneration potential. Migration of endogenous or grafted stem cells and neurons has been described in vertebrate brain, both under normal conditions from the subventricular zone along the rostral migratory stream and under pathophysiological conditions, such as degeneration or focal cerebral ischemia. Those studies, however, relied on invasive analysis of brain sections in combination with appropriate staining techniques. Here, we demonstrate the observation of cell migration under in vivo conditions, allowing the monitoring of the cell dynamics within individual animals, and for a prolonged time. Embryonic stem (ES) cells, constitutively expressing the GFP, were labeled by a lipofection procedure with a MRI contrast agent and implanted into rat brains. Focal cerebral ischemia had been induced 2 weeks before implantation of ES cells into the healthy, contralateral hemisphere. MRI at 78-μm isotropic spatial resolution permitted the observation of the implanted cells with high contrast against the host tissue, and was confirmed by GFP registration. During 3 weeks, cells migrated along the corpus callosum to the ventricular walls, and massively populated the borderzone of the damaged brain tissue on the hemisphere opposite to the implantation sites. Our results indicate that ES cells have high migrational dynamics, targeted to the cerebral lesion area. The imaging approach is ideally suited for the noninvasive observation of cell migration, engraftment, and morphological differentiation at high spatial and temporal resolution. PMID:12444255

  1. Echelle observations of the spatially resolved kinematics of a region with high-speed motions in M17 (NGC 6618)-II

    International Nuclear Information System (INIS)

    Meaburn, J.; Clayton, C.A.

    1987-01-01

    In a previous paper the authors reported the discovery of a 'jet' of ionized gas ≅ 2 arcsec across emerging from a dark area of M17 with approaching speeds up to 115 km s -1 . The vicinity of this jet has now been observed in detail in the light of [O III] 5007 A with the Manchester echelle, with a five-element multi-slit, on the Isaac Newton Telescope. A variety of new high-speed phenomena has been discovered in the ionized gas. (author)

  2. Resolved: Change Happens.

    Science.gov (United States)

    Hoover, Eric

    2003-01-01

    Describes the increasing interest in high school debate teams among minority group students. Participation in debate, no longer the province of white students alone, can result in increased college admissions, thanks in part to the Urban Debate League. (SLD)

  3. HIGH ANGULAR RESOLUTION RADIO OBSERVATIONS OF THE HL/XZ TAU REGION: MAPPING THE 50 AU PROTOPLANETARY DISK AROUND HL TAU AND RESOLVING XZ TAU S INTO A 13 AU BINARY

    International Nuclear Information System (INIS)

    Carrasco-Gonzalez, Carlos; Anglada, Guillem; RodrIguez, Luis F.; Curiel, Salvador

    2009-01-01

    We present new 7 mm and archive 1.3 cm high angular resolution observations of the HL/XZ Tau region made with the Very Large Array. At 7 mm, the emission from HL Tau seems to arise in a clumpy disk with radius of the order of 25 AU. The 1.3 cm emission from XZ Tau shows the emission from a binary system with 0.''3 (42 AU) separation, known from previous optical/IR observations. However, at 7 mm, the southern radio component resolves into a binary with 0.''09 (13 AU) separation, suggesting that XZ Tau is actually a triple star system. We suggest that the remarkable ejection of gas from the XZ Tau system observed with the Hubble Space Telescope may be related to a periastron passage of this newly discovered close binary system.

  4. Variability of O2, H2S, and pH in intertidal sediments measured on a highly resolved spatial and temporal scale

    Science.gov (United States)

    Walpersdorf, E.; Werner, U.; Bird, P.; de Beer, D.

    2003-04-01

    We investigated the variability of O_2, pH, and H_2S in intertidal sediments to assess the time- and spatial scales of changes in environmental conditions and their effects on bacterial activities. Measurements were performed over the tidal cycle and at different seasons by the use of microsensors attached to an autonomous in-situ measuring device. This study was carried out at a sand- and a mixed flat in the backbarrier area of Spiekeroog (Germany) within the frame of the DFG research group "Biogeochemistry of the Wadden Sea". Results showed that O_2 variability was not pronounced in the coastal mixed flat, where only extreme weather conditions could increase O_2 penetration. In contrast, strong dynamics in O_2 availability, pH and maximum penetration depths of several cm were found at the sandflat. In these highly permeable sediments, we directly observed tidal pumping: at high tide O_2-rich water was forced into the plate and at low tide anoxic porewater drained off the sediment. From the lower part of the plate where organic rich clayey layers were embedded in the sediment anoxic water containing H_2S leaked out during low tide. Thus advective processes, driven by the tidal pump, waves and currents, control O_2 penetration and depth distribution of H_2S and pH. The effects of the resulting porewater exchange on mineralization rates and microbial activities will be discussed.

  5. Solar Variability Controls on Rainfall in the Last Millennia: Evidence from a Highly Resolved Stalagmite Record from DeSoto Caverns (USA)

    Science.gov (United States)

    Aharon, P.; Lambert, W.; Hellstrom, J.

    2009-12-01

    Moisture transport from the Gulf of Mexico (GOM) inland has a considerable influence on both regional and continental rainfall patterns. Recent episodes of drought in the Southeastern USA exposed the vulnerability of the regional infrastructure to climate changes and gave rise to inter-state “water wars”. In order to better understand the cause of these periodic droughts and their controlling climate factors we have initiated a study of stalagmites from the DeSoto Caverns (Alabama, USA) that intersect the moisture flow from GOM. Combination of unusually high growth rates (up to 2 mm/decade), prominent dark and light seasonal layers, pristine aragonite mineralogy, precise U/Th dates acquired from mg-size samples and tight sampling (n=195) afforded generation of biannual (δ18O and δ13C of exceptional clarity spanning the last 700 yrs. The stalagmite (DSSG1) top yields isotope values (δ18O=-5.5 per-mill VPDB; δ13C=-10.1 per-mill VPDB) that are in good agreement with the predicted equilibrium isotope values. The oxygen and carbon isotope records exhibit a number of alternating negative and positive phase changes of correspond exactly with the Sun quiescence periods known as Dalton, Maunder, Spörer and Wolf Minima, and are corroborated by agreement with the positive shifts in atmospheric radiocarbon levels. Using a forward model we interpret the positive and negative δ18O and δ13C shifts during solar maxima and minima, respectively, as being primarily an expression of rapid shifts in rainfall sourced from GOM moisture and alternating between low and high rainfall intervals. The low and high rainfall intervals discerned in the stalagmite correspond to contemporaneous SST rise and fall in GOM and the Caribbean of about 1 oC amplitude. We suggest that small but measurable SST changes in the Western Hemisphere Warm Pool (WHWP), controlled by solar radiation changes between maxima and minima cycles, have a pronounced effect on the continental rainfall pattern. The

  6. Development of an optical time-resolved measurement system under high-pressure and low-temperature with a piston-cylinder pressure cell

    Science.gov (United States)

    Tsuchiya, Satoshi; Kino, Yohei; Nakagawa, Koichi; Nakagawa, Daisuke; Yamada, Jun-ichi; Toda, Yasunori

    2016-04-01

    To perform the femtosecond pump-probe spectroscopy under high pressure and low temperature, we constructed a measurement system with a piston cylinder type pressure cell installing an optical fiber bundle. The applied pressure was achieved to 6 kbar and the cell was cooled down to 15 K. Several demonstrations revealed that broadening and change of polarization of pulse (duration of ˜120 fs) owing to the dispersions in the fiber bundle are much small indicating that those have little influence on the measurement of carrier relaxation dynamics. In the measurements of κ-(BEDT-TTF)2Cu(NCS)2 under 1.3 kbar at 43 K, we have successfully detected the polarization anisotropy of the carrier relaxation dynamics and estimated the decay time in the same way as the normal measurement.

  7. Deepest Depth of Seismogenic Layer Within the Crust Beneath Japanese Islands on the Japan Sea Side Using High Resolved Earthquake Catalog and Heat Flux Data

    Science.gov (United States)

    Matsubara, M.; Yano, T. E.

    2017-12-01

    Understanding the deepest depth of seismogenic layer is important parameter for the earthquake hazard assessment because this relates to the size of earthquakes caused by the active fault. Using the indexes D90 and D95, defined as the depth above which 90% and 95 % of the whole crustal earthquakes occurred from the surface, as the lower limits of the seismogenic layer. We verified the seismogenic depth for particular earthquakes on the Japan Sea side occurred after the year of 2001. We compared with the actual main shock hypocenter depth, their aftershocks, main slip region on the fault, and depth where the temperature estimated to be 250, 300, and 450 degrees. For D90 and D95, we used two different earthquake catalogs. First, the catalog in which we relocated hypocenters for 12 years between 2001 and 2012 from the NIED Hi-net catalog (JUICE catalog, Yano et al. 2017) for high resolution hypocenter locations (Depth 0.0). This catalog is used to get D95 values. Second, the earthquake catalog redetermined with the 3D velocity structure (Matsubara and Obara, 2011) particularly for getting the D90 value around the costal region. In order to satisfy Gutenberg-Richter magnitude-frequency relation, we chose events M>1.5. We then calculated the D90 and D95 using the same method as Matsubara and Sato (2015). For depths where the temperatures are 250, 300, and 450 degrees are estimated from heat flux measured at Hi-net boreholes (Matsumoto, 2007) and other additional data Sakagawa et al. (2005). Depths are calculated using the steady-state, one-dimensional, heat conduction equation with an exponential decrease in the radioactivity heat generation introduced in Tanaka (2004). The general pattern of our results is consistent with previous studies of D90 as very deep D95 beneath the northern Hokkaido and northern Honshu and very shallow D95 along the volcanic front. We found that our D90/D95 showed the deepest boundary of hypocenter of mainshock, majority of aftershocks, main

  8. Angle-resolved photoelectron spectroscopy studies of the many-body effects in the electronic structure of high-T{sub c} cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Inosov, Dmytro S.

    2008-06-18

    In the present work some steps are done towards understanding the anomalous effects observed in the single-particle excitation spectra of cuprates. First, the electronic properties of BSCCO are considered. The main result of this part of the work is a model of the Green's function that is later used for calculating the two-particle excitation spectrum. Then, the matrix element effects in the photoemission spectra of cuprates are discussed. After a general introduction to the problem, the thesis focuses on the recently discovered anomalous behavior of the ARPES spectra that partially originates from the momentum-dependent photoemission matrix element. The momentum- and excitation energy dependence of the anomalous high-energy dispersion, termed ''waterfalls'', is covered in full detail. Understanding the role of the matrix element effects in this phenomenon proves crucial, as they obstruct the view of the underlying excitation spectrum that is of indisputable interest. For the optimally doped bilayer Bi-based cuprate, the renormalized two-particle correlation function in the superconducting state is calculated from ARPES data within an itinerant model based on the random phase approximation (RPA). (orig.)

  9. High-speed x-ray imaging with the Keck pixel array detector (Keck PAD) for time-resolved experiments at synchrotron sources

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Hugh T., E-mail: htp2@cornell.edu; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Chamberlain, Darol; Gruner, Sol M. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY (United States)

    2016-07-27

    Modern storage rings are readily capable of providing intense x-ray pulses, tens of picoseconds in duration, millions of times per second. Exploiting the temporal structure of these x-ray sources opens avenues for studying rapid structural changes in materials. Many processes (e.g. crack propagation, deformation on impact, turbulence, etc.) differ in detail from one sample trial to the next and would benefit from the ability to record successive x-ray images with single x-ray sensitivity while framing at 5 to 10 MHz rates. To this end, we have pursued the development of fast x-ray imaging detectors capable of collecting bursts of images that enable the isolation of single synchrotron bunches and/or bunch trains. The detector technology used is the hybrid pixel array detector (PAD) with a charge integrating front-end, and high-speed, in-pixel signal storage elements. A 384×256 pixel version, the Keck-PAD, with 150 µm × 150 µm pixels and 8 dedicated in-pixel storage elements is operational, has been tested at CHESS, and has collected data for compression wave studies. An updated version with 27 dedicated storage capacitors and identical pixel size has been fabricated.

  10. Dynamic behaviour of the local layer structure of antiferroelectric liquid crystals under a high electric field measured by time-resolved synchrotron x-ray microbeam diffraction

    International Nuclear Information System (INIS)

    Takahashi, Yumiko; Iida, Atsuo; Takanishi, Yoichi; Ogasawara, Toyokazu; Ishikawa, Ken; Takezoe, Hideo

    2001-01-01

    The local layer structure response to a triangular electric field in an antiferroelectric liquid crystal cell has been measured using synchrotron X-ray diffraction with 3 ms time resolution and a few μm spatial resolution. The initially coexisting vertical and horizontal chevron structures are irreversibly transformed to the layer structure with a rearranged molecular orientation at the surface (so-called vertical bookshelf structure). After the irreversible transformation, the rearranged layer structure shows a reversible transition between the horizontal chevron (high field, ferroelectric state) and the combination of the modified vertical and horizontal chevron (low field, antiferroelectric state) associated with the field-induced antiferroelectric-ferroelectric transition. The reversible layer structure has a smaller horizontal chevron angle (a few degrees) than that in the initial state (about 17deg). The detailed microbeam diffraction revealed that the layer structure at a low electric field consists of a broad vertical chevron with a small chevron angle and a bent bookshelf in combination with a horizontal chevron, depending on the analyzing position. The stripe texture is related to the modified horizontal chevron structure. (author)

  11. Dynamic behaviour of the local layer structure of antiferroelectric liquid crystals under a high electric field measured by time-resolved synchrotron x-ray microbeam diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yumiko [Graduate University for Advanced Studies, Tsukuba, Ibaraki (Japan); Iida, Atsuo [Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Takanishi, Yoichi; Ogasawara, Toyokazu; Ishikawa, Ken; Takezoe, Hideo [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Tokyo (Japan)

    2001-05-01

    The local layer structure response to a triangular electric field in an antiferroelectric liquid crystal cell has been measured using synchrotron X-ray diffraction with 3 ms time resolution and a few {mu}m spatial resolution. The initially coexisting vertical and horizontal chevron structures are irreversibly transformed to the layer structure with a rearranged molecular orientation at the surface (so-called vertical bookshelf structure). After the irreversible transformation, the rearranged layer structure shows a reversible transition between the horizontal chevron (high field, ferroelectric state) and the combination of the modified vertical and horizontal chevron (low field, antiferroelectric state) associated with the field-induced antiferroelectric-ferroelectric transition. The reversible layer structure has a smaller horizontal chevron angle (a few degrees) than that in the initial state (about 17deg). The detailed microbeam diffraction revealed that the layer structure at a low electric field consists of a broad vertical chevron with a small chevron angle and a bent bookshelf in combination with a horizontal chevron, depending on the analyzing position. The stripe texture is related to the modified horizontal chevron structure. (author)

  12. High-Speed Multiplexed Spatiotemporally Resolved Measurements of Exhaust Gas Recirculation Dynamics in a Multi-Cylinder Engine Using Laser Absorption Spectroscopy.

    Science.gov (United States)

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2016-04-01

    The need for more environmentally friendly and efficient energy conversion is of paramount importance in developing and designing next-generation internal combustion (IC) engines for transportation applications. One effective solution to reducing emissions of mono-nitrogen oxides (NOx) is exhaust gas recirculation (EGR), which has been widely implemented in modern vehicles. However, cylinder-to-cylinder and cycle-to-cycle variations in the charge-gas uniformity can be a major barrier to optimum EGR implementation on multi-cylinder engines, and can limit performance, stability, and efficiency. Precise knowledge and fine control over the EGR system is therefore crucial, particularly for optimizing advanced engine concepts such as reactivity controlled compression ignition (RCCI). An absorption-based laser diagnostic was developed to study spatiotemporal charge-gas distributions in an IC engine intake manifold in real-time. The laser was tuned to an absorption band of carbon dioxide (CO2), a standard exhaust-gas marker, near 2.7 µm. The sensor was capable of probing four separate measurement locations simultaneously, and independently analyzing EGR fraction at speeds of 5 kHz (1.2 crank-angle degree (CAD) at 1 k RPM) or faster with high accuracy. The probes were used to study spatiotemporal EGR non-uniformities in the intake manifold and ultimately promote the development of more efficient and higher performance engines. © The Author(s) 2016.

  13. Maximally resolved anharmonic OH vibrational spectrum of the water/ZnO(101 \\xAF 0) interface from a high-dimensional neural network potential

    Science.gov (United States)

    Quaranta, Vanessa; Hellström, Matti; Behler, Jörg; Kullgren, Jolla; Mitev, Pavlin D.; Hermansson, Kersti

    2018-06-01

    Unraveling the atomistic details of solid/liquid interfaces, e.g., by means of vibrational spectroscopy, is of vital importance in numerous applications, from electrochemistry to heterogeneous catalysis. Water-oxide interfaces represent a formidable challenge because a large variety of molecular and dissociated water species are present at the surface. Here, we present a comprehensive theoretical analysis of the anharmonic OH stretching vibrations at the water/ZnO(101 ¯ 0) interface as a prototypical case. Molecular dynamics simulations employing a reactive high-dimensional neural network potential based on density functional theory calculations have been used to sample the interfacial structures. In the second step, one-dimensional potential energy curves have been generated for a large number of configurations to solve the nuclear Schrödinger equation. We find that (i) the ZnO surface gives rise to OH frequency shifts up to a distance of about 4 Å from the surface; (ii) the spectrum contains a number of overlapping signals arising from different chemical species, with the frequencies decreasing in the order ν(adsorbed hydroxide) > ν(non-adsorbed water) > ν(surface hydroxide) > ν(adsorbed water); (iii) stretching frequencies are strongly influenced by the hydrogen bond pattern of these interfacial species. Finally, we have been able to identify substantial correlations between the stretching frequencies and hydrogen bond lengths for all species.

  14. Angle-resolved photoelectron spectroscopy studies of the many-body effects in the electronic structure of high-Tc cuprates

    International Nuclear Information System (INIS)

    Inosov, Dmytro S.

    2008-01-01

    In the present work some steps are done towards understanding the anomalous effects observed in the single-particle excitation spectra of cuprates. First, the electronic properties of BSCCO are considered. The main result of this part of the work is a model of the Green's function that is later used for calculating the two-particle excitation spectrum. Then, the matrix element effects in the photoemission spectra of cuprates are discussed. After a general introduction to the problem, the thesis focuses on the recently discovered anomalous behavior of the ARPES spectra that partially originates from the momentum-dependent photoemission matrix element. The momentum- and excitation energy dependence of the anomalous high-energy dispersion, termed ''waterfalls'', is covered in full detail. Understanding the role of the matrix element effects in this phenomenon proves crucial, as they obstruct the view of the underlying excitation spectrum that is of indisputable interest. For the optimally doped bilayer Bi-based cuprate, the renormalized two-particle correlation function in the superconducting state is calculated from ARPES data within an itinerant model based on the random phase approximation (RPA). (orig.)

  15. MSiReader: an open-source interface to view and analyze high resolving power MS imaging files on Matlab platform.

    Science.gov (United States)

    Robichaud, Guillaume; Garrard, Kenneth P; Barry, Jeremy A; Muddiman, David C

    2013-05-01

    During the past decade, the field of mass spectrometry imaging (MSI) has greatly evolved, to a point where it has now been fully integrated by most vendors as an optional or dedicated platform that can be purchased with their instruments. However, the technology is not mature and multiple research groups in both academia and industry are still very actively studying the fundamentals of imaging techniques, adapting the technology to new ionization sources, and developing new applications. As a result, there important varieties of data file formats used to store mass spectrometry imaging data and, concurrent to the development of MSi, collaborative efforts have been undertaken to introduce common imaging data file formats. However, few free software packages to read and analyze files of these different formats are readily available. We introduce here MSiReader, a free open source application to read and analyze high resolution MSI data from the most common MSi data formats. The application is built on the Matlab platform (Mathworks, Natick, MA, USA) and includes a large selection of data analysis tools and features. People who are unfamiliar with the Matlab language will have little difficult navigating the user-friendly interface, and users with Matlab programming experience can adapt and customize MSiReader for their own needs.

  16. U.S. regional greenhouse gas emissions analysis comparing highly resolved vehicle miles traveled and CO2 emissions: mitigation implications and their effect on atmospheric measurements

    Science.gov (United States)

    Mendoza, D. L.; Gurney, K. R.

    2010-12-01

    Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas and projections of fossil fuel energy demand show CO2 concentrations increasing indefinitely into the future. After electricity production, the transportation sector is the second largest CO2 emitting economic sector in the United States, accounting for 32.3% of the total U.S. emissions in 2002. Over 80% of the transport sector is composed of onroad emissions, with the remainder shared by the nonroad, aircraft, railroad, and commercial marine vessel transportation. In order to construct effective mitigation policy for the onroad transportation sector and more accurately predict CO2 emissions for use in transport models and atmospheric measurements, analysis must incorporate the three components that determine the CO2 onroad transport emissions: vehicle fleet composition, average speed of travel, and emissions regulation strategies. Studies to date, however, have either focused on one of these three components, have been only completed at the national scale, or have not explicitly represented CO2 emissions instead relying on the use of vehicle miles traveled (VMT) as an emissions proxy. National-level projections of VMT growth is not sufficient to highlight regional differences in CO2 emissions growth due to the heterogeneity of vehicle fleet and each state’s road network which determines the speed of travel of vehicles. We examine how an analysis based on direct CO2 emissions and an analysis based on VMT differ in terms of their emissions and mitigation implications highlighting potential biases introduced by the VMT-based approach. This analysis is performed at the US state level and results are disaggregated by road and vehicle classification. We utilize the results of the Vulcan fossil fuel CO2 emissions inventory which quantified emissions for the year 2002 across all economic sectors in the US at high resolution. We perform this comparison by fuel type,12 road types, and 12 vehicle types

  17. A case study of highly time-resolved evolution of aerosol chemical composition and optical properties during severe haze pollution in Shanghai, China

    Science.gov (United States)

    Zhu, W.; Cheng, Z.; Lou, S.

    2017-12-01

    Despite of extensive efforts into characterization of the sources in severe haze pollution periods in the megacity of Shanghai, the study of aerosol composition, mass-size distribution and optical properties to PM1 in the pollution periods remain poorly understood. Here we conducted a 47days real-time measurement of submicron aerosol (PM1) composition and size distribution by a High-Resolution Time-of-Flight Aerosol Mass spectrometer (HR-TOF-AMS), particle light scattering by a Cavity Attenuated Phase Shift ALBedo monitor (CAPS-ALB) and Photoacoustic Extinctionmeter (PAX) in Shanghai, China, from November 28, 2016 to January 12, 2017. The average PM1 concentration was 85.9(±14.7) μg/m3 during the pollution period, which was nearly 4 times higher than that of clean period. Increased scattering coefficient during EP was associated with higher secondary inorganic aerosols and organics. We also observed organics mass size distribution for different pollution extents showing different distribution characteristics. There were no obvious differences for ammonium nitrate and ammonium sulfate among the pollution periods, which represented single peak distributions, and peaks ranged at 650-700nm and 700nm, respectively. A strong relationship can be expected between PM1 compounds mass concentration size distribution and scattering coefficient, suggesting that chemical composition, size distribution of the particles and their variations could also contribute to the extinction coefficients. Organics and secondary inorganic species to particle light scattering were quantified. The results showed that organics and ammonium nitrate were the largest contribution to scattering coefficients of PM1. The contribution of (NH4)2SO4 to the light scattering exceeded that of NH4NO3 during clean period due to the enhanced sulfate concentrations. Our results elucidate substantial changes of aerosol composition, formation mechanisms, size distribution and optical properties due to local

  18. Highly Resolved Mg/Ca Depth Profiles of Planktic Foraminifer test Walls Using Single shot Measurements of fs-LA-ICPMS

    Science.gov (United States)

    Jochum, K. P.; Schiebel, R.; Stoll, B.; Weis, U.; Haug, G. H.

    2017-12-01

    Foraminifers are sensitive archives of changes in climate and marine environment. It has been shown that the Mg/Ca signal is a suitable proxy of seawater temperature, because the incorporation of Mg depends on ambient water temperature. In contrast to most former studies, where this ratio is determined by solution-based bulk analysis of 20 - 30 specimens, we have investigated Mg/Ca in single specimens and single chambers at high resolution. A new fs-200 nm-LA-ICPMS technique was developed for the µm-sized layered calcite shells. To generate depth profiles with a resolution of about 50 nm/shot, we chose a low fluence of about 0.3 Jcm-2 and performed single shot measurements of the double charged 44Ca++ and the single charged 25Mg+ ions together. Precision (RSD) of the Mg/Ca data is about 5 %. Calibration was performed with the carbonate reference material MACS-3 from the USGS. Our results for different species from the Arabian Sea and Caribbean Sea demonstrate that Mg/Ca of different chambers vary and indicate that the foraminifer individuals built their chambers in different water depths and/or experienced seasonal changes in seawater temperature caused, for example, by upwelling (cold) versus stratified (warm) conditions. Typically, the Mg/Ca ratios of the final two chambers of the planktic foraminifer Globorotalia menardii from a sediment core of the Arabian Sea differ by about 5 mmol/mol from earlier chambers (2 mmol/mol) corresponding to seawater temperatures of 28 °C and 18 °C, respectively. In addition, mass fractions of other elements like Sr, Mn, Fe, Ba, and U have been determined with fs-LA-ICPMS using fast line scans, and thus provide further insights in the ecology of foraminifers.

  19. Hard alpha-keratin degradation inside a tissue under high flux X-ray synchrotron micro-beam: a multi-scale time-resolved study.

    Science.gov (United States)

    Leccia, Emilie; Gourrier, Aurélien; Doucet, Jean; Briki, Fatma

    2010-04-01

    X-rays interact strongly with biological organisms. Synchrotron radiation sources deliver very intense X-ray photon fluxes within micro- or submicro cross-section beams, resulting in doses larger than the MGy. The relevance of synchrotron radiation analyses of biological materials is therefore questionable since such doses, million times higher than the ones used in radiotherapy, can cause huge damages in tissues, with regard to not only DNA, but also proteic and lipid organizations. Very few data concerning the effect of very high X-ray doses in tissues are available in the literature. We present here an analysis of the structural phenomena which occur when the model tissue of human hair is irradiated by a synchrotron X-ray micro-beam. The choice of hair is supported by its hierarchical and partially ordered keratin structure which can be analysed inside the tissue by X-ray diffraction. To assess the damages caused by hard X-ray micro-beams (1 microm(2) cross-section), short exposure time scattering SAXS/WAXS patterns have been recorded at beamline ID13 (ESRF) after various irradiation times. Various modifications of the scattering patterns are observed, they provide fine insight of the radiation damages at various hierarchical levels and also unexpectedly provide information about the stability of the various hierarchical structural levels. It appears that the molecular level, i.e. the alpha helices which are stabilized by hydrogen bonds and the alpha-helical coiled coils which are stabilized by hydrophobic interactions, is more sensitive to radiation than the supramolecular architecture of the keratin filament and the filament packing within the keratin associated proteins matrix, which is stabilized by disulphide bonds. (c) 2009 Elsevier Inc. All rights reserved.

  20. High-resolution metallic magnetic calorimeters for {beta}-spectroscopy on {sup 187}rhenium and position resolved X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Porst, Jan-Patrick

    2011-02-01

    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for {beta}-endpoint spectroscopy on {sup 187}rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 {mu}s could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than {delta}E{sub FWHM}<5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

  1. Continuous-flow liquid microjunction surface sampling probe connected on-line with high-performance liquid chromatography/mass spectrometry for spatially resolved analysis of small molecules and proteins.

    Science.gov (United States)

    Van Berkel, Gary J; Kertesz, Vilmos

    2013-06-30

    A continuous-flow liquid microjunction surface sampling probe extracts soluble material from surfaces for direct ionization and detection by mass spectrometry. Demonstrated here is the on-line coupling of such a probe with high-performance liquid chromatography/mass spectrometry (HPLC/MS) enabling extraction, separation and detection of small molecules and proteins from surfaces in a spatially resolved (~0.5 mm diameter spots) manner. A continuous-flow liquid microjunction surface sampling probe was connected to a six-port, two-position valve for extract collection and injection to an HPLC column. A QTRAP® 5500 hybrid triple quadrupole linear ion trap equipped with a Turbo V™ ion source operated in positive electrospray ionization (ESI) mode was used for all experiments. The system operation was tested with the extraction, separation and detection of propranolol and associated metabolites from drug dosed tissues, caffeine from a coffee bean, cocaine from paper currency, and proteins from dried sheep blood spots on paper. Confirmed in the tissue were the parent drug and two different hydroxypropranolol glucuronides. The mass spectrometric response for these compounds from different locations in the liver showed an increase with increasing extraction time (5, 20 and 40 s). For on-line separation and detection/identification of extracted proteins from dried sheep blood spots, two major protein peaks dominated the chromatogram and could be correlated with the expected masses for the hemoglobin α and β chains. Spatially resolved sampling, separation, and detection of small molecules and proteins from surfaces can be accomplished using a continuous-flow liquid microjunction surface sampling probe coupled on-line with HPLC/MS detection. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

  2. Resolving Turbine Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kruizenga, Alan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Withey, Elizabeth Ann [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The supercritical carbon dioxide (S-CO2) Brayton Cycle has gained significant attention in the last decade as an advanced power cycle capable of achieving high efficiency power conversion. Sandia National Laboratories, with support from the U.S. Department of Energy Office of Nuclear Energy (US DOE-NE), has been conducting research and development in order to deliver a technology that is ready for commercialization. Root cause analysis has been performed on the Recompression Loop at Sandia National Laboratories. It was found that particles throughout the loop are stainless steel, likely alloy 316 based upon the elemental composition. Deployment of a filter scheme is underway to both protect the turbomachinery and also for purposes of determining the specific cause for the particulate. Shake down tests of electric resistance (ER) as a potential in-situ monitoring scheme shows promise in high temperature systems. A modified instrument was purchased and held at 650°C for more than 1.5 months to date without issue. Quantitative measurements of this instrument will be benchmarked against witness samples in the future, but all qualitative trends to date are as to be expected. ER is a robust method for corrosion monitoring, but very slow at responding and can take several weeks under conditions to see obvious changes in behavior. Electrochemical noise was identified as an advanced technique that should be pursued for the ability to identify transients that would lead to poor material performance.

  3. Resolving Marital Conflicts

    Directory of Open Access Journals (Sweden)

    Islami Hatixhe

    2017-06-01

    Full Text Available Couple relations are characterized as relations of an intimate nature dominated by constant interaction or strong interdependence and mutual influence of intense feelings between spouses. In marriages where there is conflict, there are typical examples of interaction, which result in high proportion of negative communicative acts that affect the quality of marital relationships such as: loss of confidence, the emergence of frustration, feelings of anxiety, discomfort, leading to escalation of marital conflicts. Communication as a variable has a large impact on the resolution of marital conflicts. The obtained results of our research indicate that the choice of different strategies of behavior in conflict situations among our respondents primarily depend on: the degree of persistence in the pursuit of its own interests and level of cooperation in addressing the interests of others.

  4. Resolving conflicting safety cultures

    International Nuclear Information System (INIS)

    Slider, J.E.; Patterson, M.

    1993-01-01

    Several nuclear power plant sites have been wounded in the crossfire between two distinct corporate cultures. The traditional utility culture lies on one side and that of the nuclear navy on the other. The two corporate cultures lead to different perceptions of open-quotes safety culture.close quotes This clash of safety cultures obscures a very important point about nuclear plant operations: Safety depends on organizational learning. Organizational learning provides the foundation for a perception of safety culture that transcends the conflict between utility and nuclear navy cultures. Corporate culture may be defined as the knowledge, attitudes, and beliefs shared by employees of a given company. Safety culture is the part of corporate culture concerning shared attitudes and beliefs affecting individual or public safety. If the safety culture promotes behaviors that lead to greater safety, employees will tend to open-quotes do the right thingclose quotes even when circumstances and formal guidance alone do not ensure that actions will be correct. Safety culture has become particularly important to nuclear plant owners and regulators as they have sought to establish and maintain a high level of safety in today's plants

  5. Time-resolved x-ray diffraction measurements of high-density InAs quantum dots on Sb/GaAs layers and the suppression of coalescence by Sb-irradiated growth interruption

    International Nuclear Information System (INIS)

    Kakuda, Naoki; Yamaguchi, Koichi; Kaizu, Toshiyuki; Takahasi, Masamitu; Fujikawa, Seiji

    2010-01-01

    Self-assembly of high-density InAs quantum dots (QDs) on Sb-irradiated GaAs buffer layers was observed in-situ by a time-resolved X-ray diffraction (XRD) technique using a combination of XRD and molecular beam epitaxy. Evolution of dot height and lattice constant was analyzed during InAs QD growth and subsequent growth interruption (GI), and as a result, dislocated giant dots due to coalescence and coherent dots were separately evaluated. An Sb-irradiated GI (Sb-GI) method to be applied after InAs growth was attempted for the suppression of coalescence. Using this method, the XRD intensity of giant dots decreased, and the photoluminescence intensity of InAs QDs was enhanced. High-density InAs QDs without giant dots were produced by using the combination of the QD growth on the Sb-irradiated GaAs buffer layers and the Sb-GI. (author)

  6. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  7. Time-resolved ESR spectroscopy

    International Nuclear Information System (INIS)

    Beckert, D.

    1986-06-01

    The time-resolved ESR spectroscopy is one of the modern methods in radiospectroscopy and plays an important role in solving various problems in chemistry and biology. Proceeding from the basic ideas of time-resolved ESR spectroscopy the experimental equipment is described generally including the equipment developed at the Central Institute of Isotope and Radiation Research. The experimental methods applied to the investigation of effects of chemically induced magnetic polarization of electrons and to kinetic studies of free radicals in polymer systems are presented. The theory of radical pair mechanism is discussed and theoretical expressions are summarized in a computer code to compute the theoretical polarization for each pair of the radicals

  8. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. Also included are a number of enforcement actions that had been previously resolved but not published in this NUREG. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  9. Time-resolved quantitative phosphoproteomics

    DEFF Research Database (Denmark)

    Verano-Braga, Thiago; Schwämmle, Veit; Sylvester, Marc

    2012-01-01

    proteins involved in the Ang-(1-7) signaling, we performed a mass spectrometry-based time-resolved quantitative phosphoproteome study of human aortic endothelial cells (HAEC) treated with Ang-(1-7). We identified 1288 unique phosphosites on 699 different proteins with 99% certainty of correct peptide...

  10. Time-resolved vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tokmakoff, Andrei [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Champion, Paul [Northeastern Univ., Boston, MA (United States); Heilweil, Edwin J. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Nelson, Keith A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ziegler, Larry [Boston Univ., MA (United States)

    2009-05-14

    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE's Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all fiveof DOE's grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  11. Resolving Ethical Issues at School

    Science.gov (United States)

    Benninga, Jacques S.

    2013-01-01

    Although ethical dilemmas are a constant in teachers' lives, the profession has offered little in the way of training to help teachers address such issues. This paper presents a framework, based on developmental theory, for resolving professional ethical dilemmas. The Four-Component Model of Moral Maturity, when used in conjunction with a…

  12. Depth-resolved ultra-violet spectroscopic photo current-voltage measurements for the analysis of AlGaN/GaN high electron mobility transistor epilayer deposited on Si

    International Nuclear Information System (INIS)

    Ozden, Burcu; Yang, Chungman; Tong, Fei; Khanal, Min P.; Mirkhani, Vahid; Sk, Mobbassar Hassan; Ahyi, Ayayi Claude; Park, Minseo

    2014-01-01

    We have demonstrated that the depth-dependent defect distribution of the deep level traps in the AlGaN/GaN high electron mobility transistor (HEMT) epi-structures can be analyzed by using the depth-resolved ultra-violet (UV) spectroscopic photo current-voltage (IV) (DR-UV-SPIV). It is of great importance to analyze deep level defects in the AlGaN/GaN HEMT structure, since it is recognized that deep level defects are the main source for causing current collapse phenomena leading to reduced device reliability. The AlGaN/GaN HEMT epi-layers were grown on a 6 in. Si wafer by metal-organic chemical vapor deposition. The DR-UV-SPIV measurement was performed using a monochromatized UV light illumination from a Xe lamp. The key strength of the DR-UV-SPIV is its ability to provide information on the depth-dependent electrically active defect distribution along the epi-layer growth direction. The DR-UV-SPIV data showed variations in the depth-dependent defect distribution across the wafer. As a result, rapid feedback on the depth-dependent electrical homogeneity of the electrically active defect distribution in the AlGaN/GaN HEMT epi-structure grown on a Si wafer with minimal sample preparation can be elucidated from the DR-UV-SPIV in combination with our previously demonstrated spectroscopic photo-IV measurement with the sub-bandgap excitation.

  13. Depth-resolved ultra-violet spectroscopic photo current-voltage measurements for the analysis of AlGaN/GaN high electron mobility transistor epilayer deposited on Si

    Energy Technology Data Exchange (ETDEWEB)

    Ozden, Burcu; Yang, Chungman; Tong, Fei; Khanal, Min P.; Mirkhani, Vahid; Sk, Mobbassar Hassan; Ahyi, Ayayi Claude; Park, Minseo, E-mail: park@physics.auburn.edu [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

    2014-10-27

    We have demonstrated that the depth-dependent defect distribution of the deep level traps in the AlGaN/GaN high electron mobility transistor (HEMT) epi-structures can be analyzed by using the depth-resolved ultra-violet (UV) spectroscopic photo current-voltage (IV) (DR-UV-SPIV). It is of great importance to analyze deep level defects in the AlGaN/GaN HEMT structure, since it is recognized that deep level defects are the main source for causing current collapse phenomena leading to reduced device reliability. The AlGaN/GaN HEMT epi-layers were grown on a 6 in. Si wafer by metal-organic chemical vapor deposition. The DR-UV-SPIV measurement was performed using a monochromatized UV light illumination from a Xe lamp. The key strength of the DR-UV-SPIV is its ability to provide information on the depth-dependent electrically active defect distribution along the epi-layer growth direction. The DR-UV-SPIV data showed variations in the depth-dependent defect distribution across the wafer. As a result, rapid feedback on the depth-dependent electrical homogeneity of the electrically active defect distribution in the AlGaN/GaN HEMT epi-structure grown on a Si wafer with minimal sample preparation can be elucidated from the DR-UV-SPIV in combination with our previously demonstrated spectroscopic photo-IV measurement with the sub-bandgap excitation.

  14. WFIRST: Resolving the Milky Way Galaxy

    Science.gov (United States)

    Kalirai, Jason; Conroy, Charlie; Dressler, Alan; Geha, Marla; Levesque, Emily; Lu, Jessica; Tumlinson, Jason

    2018-01-01

    WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. In this poster, we describe the activities of the WFIRST Science Investigation Team (SIT), "Resolving the Milky Way with WFIRST". Notional programs guiding our analysis include targeting sightlines to establish the first well-resolved large scale maps of the Galactic bulge aand central region, pockets of star formation in the disk, benchmark star clusters, and halo substructure and ultra faint dwarf satellites. As an output of this study, our team is building optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of Milky Way environments including new astrometric studies; and strategies and automated algorithms to find substructure and dwarf galaxies in the Milky Way through the WFIRST High Latitude Survey.

  15. Indoor Measurement of Angle Resolved Light Absorption by Black Silicon

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Iandolo, Beniamino; Davidsen, Rasmus Schmidt

    2017-01-01

    Angle resolved optical spectroscopy of photovoltaic (PV) samples gives crucial information on PV panels under realistic working conditions. Here, we introduce measurements of angle resolved light absorption by PV cells, performed indoors using a collimated high radiance broadband light source. Our...... indoor method offers a significant simplification as compared to measurements by solar trackers. As a proof-of-concept demonstration, we show characterization of black silicon solar cells. The experimental results showed stable and reliable optical responses that makes our setup suitable for indoor......, angle resolved characterization of solar cells....

  16. Minimum resolvable power contrast model

    Science.gov (United States)

    Qian, Shuai; Wang, Xia; Zhou, Jingjing

    2018-01-01

    Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

  17. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1994-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October - December 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  18. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July - September 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  19. Supra-aortic low-dose contrast-enhanced time-resolved magnetic resonance (MR) angiography at 3 T: comparison with time-of-flight MR angiography and high-resolution contrast-enhanced MR angiography.

    Science.gov (United States)

    Lee, Youn-Joo; Kim, Bum-soo; Koo, Ja-Sung; Kim, Bom-Yi; Jang, Jinhee; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin

    2015-06-01

    Low-dose, time-resolved, contrast-enhanced, magnetic resonance angiography (TR-CEMRA) has been described previously; however, a comparative study between low dose TR-CEMRA and time-of-flight MRA (TOF-MRA) in the diagnosis of supra-aortic arterial stenosis has not yet been published. To demonstrate the feasibility and effectiveness of low-dose TR-CEMRA compared with TOF-MRA, using high-resolution contrast-enhanced MRA (HR-CEMRA) as the reference standard. This prospective study consisted of 30 consecutive patients. All patients underwent TOF-MRA of the neck and circle of Willis and supra-aortic HR-CEMRA, followed by supra-aortic low-dose TR-CEMRA. Gadoterate meglumine (Gd-DOTA, Dotarem(®), Guerbet, Roissy CdG Cedex, France) was injected at a dose of 0.1 mmol/kg for HR-CEMRA, followed by a 0.03 mmol/kg bolus for low-dose TR-CEMRA. Three readers evaluated the assessibility and image quality, and then two readers classified each stenosis into the following categories: normal (0-30%), mild stenosis (31-50%), moderate (51-70%), severe (71-99%), and occlusion. TR-CEMRA and HR-CEMRA showed a greater number of assessable arterial segments than TOF-MRA (P supra-aortic arterial stenosis, and could be more useful option than TOF-MRA. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Time-resolved x-ray diagnostics

    International Nuclear Information System (INIS)

    Lyons, P.B.

    1981-01-01

    Techniques for time-resolved x-ray diagnostics will be reviewed with emphasis on systems utilizing x-ray diodes or scintillators. System design concerns for high-bandwidth (> 1 GHz) diagnostics will be emphasized. The limitations of a coaxial cable system and a technique for equalizing to improve bandwidth of such a system will be reviewed. Characteristics of new multi-GHz amplifiers will be presented. An example of a complete operational system on the Los Alamos Helios laser will be presented which has a bandwidth near 3 GHz over 38 m of coax. The system includes the cable, an amplifier, an oscilloscope, and a digital camera readout

  1. Spatially Resolved Circumnuclear Dust in Centaurus A

    OpenAIRE

    Karovska, Margarita; Marengo, Massimo; Elvis, Martin; Fazio, Giovanni; Hora, Joseph; Hinz, Philip; Hoffmann, William; Meyer, Michael; Mamajek, Eric

    2003-01-01

    In this paper we present results from our exploratory mid-IR study of Centaurus A circumnuclear environment using high-angular resolution imaging at the Magellan 6.5m telescope with the MIRAC/BLINC camera. We detected emission from a compact region surrounding the nuclear source, and obtained photometry at 8.8 microns and in the N band. Our analysis suggests that the nuclear region is resolved with a size of approximately 3 pc. The mid-IR emission from this region is likely associated with co...

  2. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-09-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  3. Mediation for resolving family disputes

    Directory of Open Access Journals (Sweden)

    Kamenecka-Usova M.

    2016-01-01

    Full Text Available Nowadays the understanding of the institute of marriage and its importance in the society has changed. Marriage is no longer assumed to be a commitment for a lifetime. As the principle of equality has replaced hierarchy as the guiding principle of family law it gave more grounds for family disputes and it became socially acceptable to leave marriages that are intolerable or merely unfulfilling. The aim of this article is to suggest an alternative dispute resolution method-mediation as a worthy option for resolving family conflicts.

  4. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  5. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-02-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1990) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  6. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  7. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1990) and includes copies of letters, notices, and orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  8. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-08-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  9. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1990-09-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1990) and includes copies of letters, notices, and orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  10. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-06-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  11. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-05-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  12. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1993) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  13. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1993-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1992) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  14. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-07-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April-June 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  15. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1991-11-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  16. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1992-03-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1991) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  17. Enforcement actions: Significant actions resolved

    International Nuclear Information System (INIS)

    1989-12-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1989) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  18. Development and application of methods and models for the calculation of spatially and temporally highly resolved emissions in Europe; Entwicklung und Anwendung von Methoden und Modellen zur Berechnung von raeumlich und zeitlich hochaufgeloesten Emissionen in Europa

    Energy Technology Data Exchange (ETDEWEB)

    Thiruchittampalam, Balendra

    2014-04-08

    High spatial and temporal resolution models are essential for answering many questions of air quality management and climate modeling. High-resolution emission models are required to determine the concentration of pollutants using chemical transport models, and to quantify the impacts on health and environment and in particular to develop adequate countermeasures. The aim of this work is to develop methods for the calculation of spatially and temporally high-resolved emissions and to apply these exemplarily on a 1 km x 1 km and hourly resolution for the year 2008 in the EU-27 and EFTA countries. The derivation of methods for the spatial and temporal resolution of emissions with corresponding detailed equations is one of the major improvements that have been carried out in the course of this work. The improvement of the spatial distribution of emissions from the point source relevant sectors like energy supply, industry and waste management is achieved by considering sector specific diffuse emission shares. The progress of the spatial distribution of emissions from households is in particular the development of a fuel type weighted distribution over Europe. Another main focus is the development of the spatial distribution of road transport emissions. Due to the restricted access to traffic count data at the European level, methods have been established to provide reliable emissions on grid level for Europe. The progress in the spatial distribution of agricultural emissions is achieved by the consideration of diffuse shares similar to the other point source relevant sectors like energy supply or industry. In addition to the spatial distribution of the emissions the temporal resolution is a main focus of this work, since the state of knowledge of the temporal resolution of emissions in Europe is still rudimentary. Therefore, it was necessary to develop in particular time curves for the hourly resolution of emissions for the main sectors, namely electricity and heat

  19. Development of a high-resolution soft x-ray (30--1500 eV) beamline at the Advanced Light Source and its use for the study of angle-resolved photoemission extended fine structure

    International Nuclear Information System (INIS)

    Huff, W.R.A.

    1996-02-01

    ALS Bending magnet beamline 9.3.2 is for high resolution spectroscopy, with circularly polarized light. Fixed included-angle SGM uses three gratings for 30--1500 eV photons; circular polarization is produced by an aperture for selecting the beam above or below the horizontal plane. Photocurrent from upper and lower jaws of entrance slit sets a piezoelectric drive feedback loop on the vertically deflecting mirror for stable beam. End station has a movable platform. With photomeission data from Stanford, structure of c(2x2)P/Fe(100) was determined using angle-resolved photoemission extended fine structure (ARPEFS). Multiple-scattering spherical-wave (MSSW) calculations indicate that P atoms adsorb in fourfold hollow sites 1.02A above the first Fe layer. Self-consistent-field Xα scattered wave calculation confirm that the Fe 1 -Fe 2 space is contracted for S/Fe but not for P/Fe; comparison is made to atomic N and O on Fe(100). Final-state effects on ARPEFS curves used literature data from the S 1s and 2p core levels of c(2x2)S/Ni(001); a generalized Ramsauer-Townsend splitting is present in the 1s but not 2p data. An approximate method for analyzing ARPEFS data from a non-s initial state using only the higher-ell partial wave was tested successfully. ARPEFS data from clean surfaces were collected normal to Ni(111) (3p core levels) and 5 degree off-normal from Cu(111)(3s, 3p). Fourier transforms (FT) resemble adsorbate systems, showing backscattering signals from atoms up to 4 layers below emitters. 3p FTs show scattering from 6 nearest neighbors in the same crystal layer as the emitters. MSSW calulation indicate that Cu 3p photoemission is mostly d-wave. FTs also indicate double-scattering and single-scattering from laterally distant atoms; calculations indicate that the signal is dominated by photoemission from the first 2 crystal layers

  20. Femtosecond Time-resolved Optical Polarigraphy (FTOP)

    International Nuclear Information System (INIS)

    Aoshima, S.; Fujimoto, M.; Hosoda, M.; Tsuchiya, Y.

    2000-01-01

    A novel time-resolved imaging technique named FTOP (Femtosecond Time-resolved Optical Polarigraphy) for visualizing the ultrafast propagation dynamics of intense light pulses in a medium has been proposed and demonstrated. Femtosecond snapshot images can be created with a high spatial resolution by imaging only the polarization components of the probe pulse; these polarization components change due to the instantaneous birefringence induced by the pump pulse in the medium. Ultrafast temporal changes in the two-dimensional spatial distribution of the optical pulse intensity were clearly visualized in consecutive images by changing the delay between the pump and probe. We observe that several filaments appear and then come together before the vacuum focus due to nonlinear effects in air. We also prove that filamentation dynamics such as the formation position and the propagation behavior are complex and are strongly affected by the pump energy. The results collected clearly show that this method FTOP succeeds for the first time in directly visualizing the ultrafast dynamics of the self-modulated nonlinear propagation of light. (author)

  1. Techniques used to increase the resolving power of magnetic ...

    African Journals Online (AJOL)

    Magnetic resonance imaging is a method which can be used to obtain highly detailed and clear images of organs inside the body. The objective of this article is evaluation of techniques used to increase the resolving power of magnetic resonance images. The use of gradient techniques with high functionality will increase ...

  2. Time-resolved fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gustavsson, Thomas; Mialocq, Jean-Claude

    2007-01-01

    This article addresses the evolution in time of light emitted by a molecular system after a brief photo-excitation. The authors first describe fluorescence from a photo-physical point of view and discuss the characterization of the excited state. Then, they explain some basic notions related to fluorescence characterization (lifetime and decays, quantum efficiency, so on). They present the different experimental methods and techniques currently used to study time-resolved fluorescence. They discuss basic notions of time resolution and spectral reconstruction. They briefly present some conventional methods: intensified Ccd cameras, photo-multipliers and photodiodes associated with a fast oscilloscope, and phase modulation. Other methods and techniques are more precisely presented: time-correlated single photon counting (principle, examples, and fluorescence lifetime imagery), streak camera (principle, examples), and optical methods like the Kerr optical effect (principle and examples) and fluorescence up-conversion (principle and theoretical considerations, examples of application)

  3. A time-resolved image sensor for tubeless streak cameras

    Science.gov (United States)

    Yasutomi, Keita; Han, SangMan; Seo, Min-Woong; Takasawa, Taishi; Kagawa, Keiichiro; Kawahito, Shoji

    2014-03-01

    This paper presents a time-resolved CMOS image sensor with draining-only modulation (DOM) pixels for tube-less streak cameras. Although the conventional streak camera has high time resolution, the device requires high voltage and bulky system due to the structure with a vacuum tube. The proposed time-resolved imager with a simple optics realize a streak camera without any vacuum tubes. The proposed image sensor has DOM pixels, a delay-based pulse generator, and a readout circuitry. The delay-based pulse generator in combination with an in-pixel logic allows us to create and to provide a short gating clock to the pixel array. A prototype time-resolved CMOS image sensor with the proposed pixel is designed and implemented using 0.11um CMOS image sensor technology. The image array has 30(Vertical) x 128(Memory length) pixels with the pixel pitch of 22.4um. .

  4. Time - resolved thermography at Tokamak T-10

    International Nuclear Information System (INIS)

    Grunow, C.; Guenther, K.; Lingertat, J.; Chicherov, V.M.; Evstigneev, S.A.; Zvonkov, S.N.

    1987-01-01

    Thermographic experiments were performed at T-10 tokamak to investigate the thermic coupling of plasma and the limiter. The limiter is an internal equipment of the vacuum vessel of tokamak-type fusion devices and the interaction of plasma with limiter results a high thermal load of limiter for short time. In according to improve the limiter design the temperature distribution on the limiter surface was measured by a time-resolved thermographic method. Typical isotherms and temperature increment curves are presented. This measurement can be used as a systematic plasma diagnostic method because the limiter is installed in the tokamak whereas special additional probes often disturb the plasma discharge. (D.Gy.) 3 refs.; 7 figs

  5. Angle-resolved photoemission extended fine structure

    International Nuclear Information System (INIS)

    Barton, J.J.

    1985-03-01

    Measurements of the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) from the S(1s) core level of a c(2 x 2)S/Ni(001) are analyzed to determine the spacing between the S overlayer and the first and second Ni layers. ARPEFS is a type of photoelectron diffraction measurement in which the photoelectron kinetic energy is swept typically from 100 to 600 eV. By using this wide range of intermediate energies we add high precision and theoretical simplification to the advantages of the photoelectron diffraction technique for determining surface structures. We report developments in the theory of photoelectron scattering in the intermediate energy range, measurement of the experimental photoemission spectra, their reduction to ARPEFS, and the surface structure determination from the ARPEFS by combined Fourier and multiple-scattering analyses. 202 refs., 67 figs., 2 tabs

  6. Resolvability of regional density structure

    Science.gov (United States)

    Plonka, A.; Fichtner, A.

    2016-12-01

    Lateral density variations are the source of mass transport in the Earth at all scales, acting as drivers of convectivemotion. However, the density structure of the Earth remains largely unknown since classic seismic observables and gravityprovide only weak constraints with strong trade-offs. Current density models are therefore often based on velocity scaling,making strong assumptions on the origin of structural heterogeneities, which may not necessarily be correct. Our goal is to assessif 3D density structure may be resolvable with emerging full-waveform inversion techniques. We have previously quantified the impact of regional-scale crustal density structure on seismic waveforms with the conclusion that reasonably sized density variations within thecrust can leave a strong imprint on both travel times and amplitudes, and, while this can produce significant biases in velocity and Q estimates, the seismic waveform inversion for density may become feasible. In this study we performprincipal component analyses of sensitivity kernels for P velocity, S velocity, and density. This is intended to establish theextent to which these kernels are linearly independent, i.e. the extent to which the different parameters may be constrainedindependently. Since the density imprint we observe is not exclusively linked to travel times and amplitudes of specific phases,we consider waveform differences between complete seismograms. We test the method using a known smooth model of the crust and seismograms with clear Love and Rayleigh waves, showing that - as expected - the first principal kernel maximizes sensitivity to SH and SV velocity structure, respectively, and that the leakage between S velocity, P velocity and density parameter spaces is minimal in the chosen setup. Next, we apply the method to data from 81 events around the Iberian Penninsula, registered in total by 492 stations. The objective is to find a principal kernel which would maximize the sensitivity to density

  7. Time resolved spectroscopy of GRB 030501 using INTEGRAL

    DEFF Research Database (Denmark)

    Beckmann, V.; Borkowski, J.; Courvoisier, T.J.L.

    2003-01-01

    The gamma-ray instruments on-board INTEGRAL offer an unique opportunity to perform time resolved analysis on GRBs. The imager IBIS allows accurate positioning of GRBs and broad band spectral analysis, while SPI provides high resolution spectroscopy. GRB 030501 was discovered by the INTEGRAL Burst...... the Ulysses and RHESSI experiments....

  8. Imposing resolved turbulence in CFD simulations

    DEFF Research Database (Denmark)

    Gilling, L.; Sørensen, Niels N.

    2011-01-01

    In large‐eddy simulations, the inflow velocity field should contain resolved turbulence. This paper describes and analyzes two methods for imposing resolved turbulence in the interior of the domain in Computational Fluid Dynamics simulations. The intended application of the methods is to impose...

  9. Chromatographic background drift correction coupled with parallel factor analysis to resolve coelution problems in three-dimensional chromatographic data: quantification of eleven antibiotics in tap water samples by high-performance liquid chromatography coupled with a diode array detector.

    Science.gov (United States)

    Yu, Yong-Jie; Wu, Hai-Long; Fu, Hai-Yan; Zhao, Juan; Li, Yuan-Na; Li, Shu-Fang; Kang, Chao; Yu, Ru-Qin

    2013-08-09

    Chromatographic background drift correction has been an important field of research in chromatographic analysis. In the present work, orthogonal spectral space projection for background drift correction of three-dimensional chromatographic data was described in detail and combined with parallel factor analysis (PARAFAC) to resolve overlapped chromatographic peaks and obtain the second-order advantage. This strategy was verified by simulated chromatographic data and afforded significant improvement in quantitative results. Finally, this strategy was successfully utilized to quantify eleven antibiotics in tap water samples. Compared with the traditional methodology of introducing excessive factors for the PARAFAC model to eliminate the effect of background drift, clear improvement in the quantitative performance of PARAFAC was observed after background drift correction by orthogonal spectral space projection. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. The Resolved Stellar Populations Early Release Science Program

    Science.gov (United States)

    Weisz, Daniel; Anderson, J.; Boyer, M.; Cole, A.; Dolphin, A.; Geha, M.; Kalirai, J.; Kallivayalil, N.; McQuinn, K.; Sandstrom, K.; Williams, B.

    2017-11-01

    We propose to obtain deep multi-band NIRCam and NIRISS imaging of three resolved stellar systems within 1 Mpc (NOI 104). We will use this broad science program to optimize observational setups and to develop data reduction techniques that will be common to JWST studies of resolved stellar populations. We will combine our expertise in HST resolved star studies with these observations to design, test, and release point spread function (PSF) fitting software specific to JWST. PSF photometry is at the heart of resolved stellar populations studies, but is not part of the standard JWST reduction pipeline. Our program will establish JWST-optimized methodologies in six scientific areas: star formation histories, measurement of the sub-Solar mass stellar IMF, extinction maps, evolved stars, proper motions, and globular clusters, all of which will be common pursuits for JWST in the local Universe. Our observations of globular cluster M92, ultra-faint dwarf Draco II, and star-forming dwarf WLM, will be of high archival value for other science such as calibrating stellar evolution models, measuring properties of variable stars, and searching for metal-poor stars. We will release the results of our program, including PSF fitting software, matched HST and JWST catalogs, clear documentation, and step-by-step tutorials (e.g., Jupyter notebooks) for data reduction and science application, to the community prior to the Cycle 2 Call for Proposals. We will host a workshop to help community members plan their Cycle 2 observations of resolved stars. Our program will provide blueprints for the community to efficiently reduce and analyze JWST observations of resolved stellar populations.

  11. Time resolved ion beam induced charge collection

    International Nuclear Information System (INIS)

    Sexton W, Frederick; Walsh S, David; Doyle L, Barney; Dodd E, Paul

    2000-01-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a -.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients

  12. Time resolved ion beam induced charge collection

    Energy Technology Data Exchange (ETDEWEB)

    SEXTON,FREDERICK W.; WALSH,DAVID S.; DOYLE,BARNEY L.; DODD,PAUL E.

    2000-04-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a {minus}.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients.

  13. Spatially Resolved Isotopic Source Signatures of Wetland Methane Emissions

    Science.gov (United States)

    Ganesan, A. L.; Stell, A. C.; Gedney, N.; Comyn-Platt, E.; Hayman, G.; Rigby, M.; Poulter, B.; Hornibrook, E. R. C.

    2018-04-01

    We present the first spatially resolved wetland δ13C(CH4) source signature map based on data characterizing wetland ecosystems and demonstrate good agreement with wetland signatures derived from atmospheric observations. The source signature map resolves a latitudinal difference of 10‰ between northern high-latitude (mean -67.8‰) and tropical (mean -56.7‰) wetlands and shows significant regional variations on top of the latitudinal gradient. We assess the errors in inverse modeling studies aiming to separate CH4 sources and sinks by comparing atmospheric δ13C(CH4) derived using our spatially resolved map against the common assumption of globally uniform wetland δ13C(CH4) signature. We find a larger interhemispheric gradient, a larger high-latitude seasonal cycle, and smaller trend over the period 2000-2012. The implication is that erroneous CH4 fluxes would be derived to compensate for the biases imposed by not utilizing spatially resolved signatures for the largest source of CH4 emissions. These biases are significant when compared to the size of observed signals.

  14. Knowledge Extraction from Atomically Resolved Images.

    Science.gov (United States)

    Vlcek, Lukas; Maksov, Artem; Pan, Minghu; Vasudevan, Rama K; Kalinin, Sergei V

    2017-10-24

    Tremendous strides in experimental capabilities of scanning transmission electron microscopy and scanning tunneling microscopy (STM) over the past 30 years made atomically resolved imaging routine. However, consistent integration and use of atomically resolved data with generative models is unavailable, so information on local thermodynamics and other microscopic driving forces encoded in the observed atomic configurations remains hidden. Here, we present a framework based on statistical distance minimization to consistently utilize the information available from atomic configurations obtained from an atomically resolved image and extract meaningful physical interaction parameters. We illustrate the applicability of the framework on an STM image of a FeSe x Te 1-x superconductor, with the segregation of the chalcogen atoms investigated using a nonideal interacting solid solution model. This universal method makes full use of the microscopic degrees of freedom sampled in an atomically resolved image and can be extended via Bayesian inference toward unbiased model selection with uncertainty quantification.

  15. Resolving Environmental Effects of Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Karin C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DeGeorge, Elise M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Copping, Andrea E. [Pacific Northwest National Laboratory; May, Roel [Norwegian Institute for Nature Research; Bennet, Finlay [Marine Scotland Science; Warnas, Marijke [Rijkswaterstaat; Perron, Muriel [nateco AG; Elmqvist, Asa [Swedish Environmental Protection Agency

    2018-04-25

    Concerns for potential wildlife impacts resulting from land-based and offshore wind energy have created challenges for wind project development. Research is not always adequately supported, results are neither always readily accessible nor are they satisfactorily disseminated, and so decisions are often made based on the best available information, which may be missing key findings. The potential for high impacts to avian and bat species and marine mammals have been used by wind project opponents to stop, downsize, or severely delay project development. The global nature of the wind industry - combined with the understanding that many affected species cross-national boundaries, and in many cases migrate between continents - also points to the need to collaborate on an international level. The International Energy Agency (IEA) Wind Technology Collaborative Programs facilitates coordination on key research issues. IEA Wind Task 34 - WREN: Working Together to Resolve Environmental Effects of Wind Energy-is a collaborative forum to share lessons gained from field research and modeling, including management methods, wildlife monitoring methods, best practices, study results, and successful approaches to mitigating impacts and addressing the cumulative effects of wind energy on wildlife.

  16. Enzyme reactions and their time resolved measurements

    International Nuclear Information System (INIS)

    Hajdu, Janos

    1990-01-01

    This paper discusses experimental strategies in data collection with the Laue method and summarises recent results using synchrotron radiation. Then, an assessment is made of the progress towards time resolved studies with protein crystals and the problems that remain. The paper consists of three parts which respectively describe some aspects of Laue diffraction, recent examples of structural results from Laue diffraction, and kinetic Laue crystallography. In the first part, characteristics of Laue diffraction is discussed first, focusing on the harmonics problems, spatials problem, wavelength normalization, low resolution hole, data completeness, and uneven coverage of reciprocal space. Then, capture of the symmetry unique reflection set is discussed focusing on the effect of wavelength range on the number of reciprocal lattice points occupying diffracting positions, effect of crystal to film distance and the film area and shape on the number of reflections captured, and effect of crystal symmetry on the number of unique reflections within the number of reflections captured. The second part addresses the determination of the structure of turkey egg white lysozyme, and calcium binding in tomato bushy stunt virus. The third part describes the initiation of reactions in enzyme crystals, picosecond Laue diffraction at high energy storage rings, and detectors. (N.K.)

  17. Time-resolved spectroscopy in synchrotron radiation

    International Nuclear Information System (INIS)

    Rehn, V.; Stanford Univ., CA

    1980-01-01

    Synchrotron radiation (SR) from large-diameter storage rings has intrinsic time structure which facilitates time-resolved measurements form milliseconds to picoseconds and possibly below. The scientific importance of time-resolved measurements is steadily increasing as more and better techniques are discovered and applied to a wider variety of scientific problems. This paper presents a discussion of the importance of various parameters of the SR facility in providing for time-resolved spectroscopy experiments, including the role of beam-line optical design parameters. Special emphasis is placed on the requirements of extremely fast time-resolved experiments with which the effects of atomic vibrational or relaxation motion may be studied. Before discussing the state-of-the-art timing experiments, we review several types of time-resolved measurements which have now become routine: nanosecond-range fluorescence decay times, time-resolved emission and excitation spectroscopies, and various time-of-flight applications. These techniques all depend on a short SR pulse length and a long interpulse period, such as is provided by a large-diameter ring operating in a single-bunch mode. In most cases, the pulse shape and even the stability of the pulse shape is relatively unimportant as long as the pulse length is smaller than the risetime of the detection apparatus, typically 1 to 2 ns. For time resolution smaller than 1 ns, the requirements on the pulse shape become more stringent. (orig./FKS)

  18. The Resolved Stellar Populations Early Release Science Program

    Science.gov (United States)

    Gilbert, Karoline; Weisz, Daniel; Resolved Stellar Populations ERS Program Team

    2018-06-01

    The Resolved Stellar Populations Early Release Science Program (PI D. Weisz) will observe Local Group targets covering a range of stellar density and star formation histories, including a globular cluster, and ultra-faint dwarf galaxy, and a star-forming dwarf galaxy. Using observations of these diverse targets we will explore a broad science program: we will measure star formation histories, the sub-solar stellar initial mass function, and proper motions, perform studies of evolved stars, and map extinction in the target fields. Our observations will be of high archival value for other science such as calibrating stellar evolution models, studying variable stars, and searching for metal-poor stars. We will determine optimal observational setups and develop data reduction techniques that will be common to JWST studies of resolved stellar populations. We will also design, test, and release point spread function (PSF) fitting software specific to NIRCam and NIRISS, required for the crowded stellar regime. Prior to the Cycle 2 Call for Proposals, we will release PSF fitting software, matched HST and JWST catalogs, and clear documentation and step-by-step tutorials (such as Jupyter notebooks) for reducing crowded stellar field data and producing resolved stellar photometry catalogs, as well as for specific resolved stellar photometry science applications.

  19. An x-ray detector for time-resolved studies

    International Nuclear Information System (INIS)

    Rodricks, B.; Brizard, C.; Clarke, R.; Lowe, W.

    1992-01-01

    The development of ultrahigh-brightness x-ray sources makes time-resolved x-ray studies more and more feasible. Improvements in x-ray optics components are also critical for obtaining the appropriate beam for a particular type of experiment. Moreover, fast parallel detectors will be essential in order to exploit the combination of high intensity x-ray sources and novel optics for time-resolved experiments. A CCD detector with a time resolution of microseconds has been developed at the Advanced Photon Source (APS). This detector is fully programmable using CAMAC electronics and a Micro Vax computer. The techniques of time-resolved x-ray studies, which include scattering, microradiography, microtomography, stroboscopy, etc., can be applied to a range of phenomena (including rapid thermal annealing, surface ordering, crystallization, and the kinetics of phase transition) in order to understand these time-dependent microscopic processes. Some of these applications will be illustrated by recent results performed at synchrotrons. New powerful x-ray sources now under construction offer the opportunity to apply innovative approaches in time-resolved work

  20. Resolving Gas-Phase Metallicity In Galaxies

    Science.gov (United States)

    Carton, David

    2017-06-01

    Chapter 2: As part of the Bluedisk survey we analyse the radial gas-phase metallicity profiles of 50 late-type galaxies. We compare the metallicity profiles of a sample of HI-rich galaxies against a control sample of HI-'normal' galaxies. We find the metallicity gradient of a galaxy to be strongly correlated with its HI mass fraction {M}{HI}) / {M}_{\\ast}). We note that some galaxies exhibit a steeper metallicity profile in the outer disc than in the inner disc. These galaxies are found in both the HI-rich and control samples. This contradicts a previous indication that these outer drops are exclusive to HI-rich galaxies. These effects are not driven by bars, although we do find some indication that barred galaxies have flatter metallicity profiles. By applying a simple analytical model we are able to account for the variety of metallicity profiles that the two samples present. The success of this model implies that the metallicity in these isolated galaxies may be in a local equilibrium, regulated by star formation. This insight could provide an explanation of the observed local mass-metallicity relation. Chapter 3 We present a method to recover the gas-phase metallicity gradients from integral field spectroscopic (IFS) observations of barely resolved galaxies. We take a forward modelling approach and compare our models to the observed spatial distribution of emission line fluxes, accounting for the degrading effects of seeing and spatial binning. The method is flexible and is not limited to particular emission lines or instruments. We test the model through comparison to synthetic observations and use downgraded observations of nearby galaxies to validate this work. As a proof of concept we also apply the model to real IFS observations of high-redshift galaxies. From our testing we show that the inferred metallicity gradients and central metallicities are fairly insensitive to the assumptions made in the model and that they are reliably recovered for galaxies

  1. Recent trends in spin-resolved photoelectron spectroscopy

    Science.gov (United States)

    Okuda, Taichi

    2017-12-01

    Since the discovery of the Rashba effect on crystal surfaces and also the discovery of topological insulators, spin- and angle-resolved photoelectron spectroscopy (SARPES) has become more and more important, as the technique can measure directly the electronic band structure of materials with spin resolution. In the same way that the discovery of high-Tc superconductors promoted the development of high-resolution angle-resolved photoelectron spectroscopy, the discovery of this new class of materials has stimulated the development of new SARPES apparatus with new functions and higher resolution, such as spin vector analysis, ten times higher energy and angular resolution than conventional SARPES, multichannel spin detection, and so on. In addition, the utilization of vacuum ultra violet lasers also opens a pathway to the realization of novel SARPES measurements. In this review, such recent trends in SARPES techniques and measurements will be overviewed.

  2. Parameterized and resolved Southern Ocean eddy compensation

    Science.gov (United States)

    Poulsen, Mads B.; Jochum, Markus; Nuterman, Roman

    2018-04-01

    The ability to parameterize Southern Ocean eddy effects in a forced coarse resolution ocean general circulation model is assessed. The transient model response to a suite of different Southern Ocean wind stress forcing perturbations is presented and compared to identical experiments performed with the same model in 0.1° eddy-resolving resolution. With forcing of present-day wind stress magnitude and a thickness diffusivity formulated in terms of the local stratification, it is shown that the Southern Ocean residual meridional overturning circulation in the two models is different in structure and magnitude. It is found that the difference in the upper overturning cell is primarily explained by an overly strong subsurface flow in the parameterized eddy-induced circulation while the difference in the lower cell is mainly ascribed to the mean-flow overturning. With a zonally constant decrease of the zonal wind stress by 50% we show that the absolute decrease in the overturning circulation is insensitive to model resolution, and that the meridional isopycnal slope is relaxed in both models. The agreement between the models is not reproduced by a 50% wind stress increase, where the high resolution overturning decreases by 20%, but increases by 100% in the coarse resolution model. It is demonstrated that this difference is explained by changes in surface buoyancy forcing due to a reduced Antarctic sea ice cover, which strongly modulate the overturning response and ocean stratification. We conclude that the parameterized eddies are able to mimic the transient response to altered wind stress in the high resolution model, but partly misrepresent the unperturbed Southern Ocean meridional overturning circulation and associated heat transports.

  3. The conforming brain and deontological resolve.

    Science.gov (United States)

    Pincus, Melanie; LaViers, Lisa; Prietula, Michael J; Berns, Gregory

    2014-01-01

    Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC) during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules.

  4. The conforming brain and deontological resolve.

    Directory of Open Access Journals (Sweden)

    Melanie Pincus

    Full Text Available Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules.

  5. Resolving Ethical Dilemmas in Financial Audit

    OpenAIRE

    Professor PhD Turlea Eugeniu; PhD Student Mocanu Mihaela

    2010-01-01

    Resolving ethical dilemmas is a difficult endeavor in any field and financial auditing makes no exception. Ethical dilemmas are complex situations which derive from a conflict and in which a decision among several alternatives is needed. Ethical dilemmas are common in the work of the financial auditor, whose mission is to serve the interests of the public at large, not those of the auditee’s managers who mandate him/her. The objective of the present paper is to offer support in resolving ethi...

  6. Resolve Instrument on X-ray Astronomy Recovery Mission (XARM)

    Science.gov (United States)

    Ishisaki, Y.; Ezoe, Y.; Yamada, S.; Ichinohe, Y.; Fujimoto, R.; Takei, Y.; Yasuda, S.; Ishida, M.; Yamasaki, N. Y.; Maeda, Y.; Tsujimoto, M.; Iizuka, R.; Koyama, S.; Noda, H.; Tamagawa, T.; Sawada, M.; Sato, K.; Kitamoto, S.; Hoshino, A.; Brown, G. V.; Eckart, M. E.; Hayashi, T.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; Mori, H.; Okajima, T.; Porter, F. S.; Soong, Y.; McCammon, D.; Szymkowiak, A. E.

    2018-04-01

    The X-ray Astronomy Recovery Mission (XARM) is a recovery mission of ASTRO-H/Hitomi, which is expected to be launched in Japanese Fiscal Year of 2020 at the earliest. The Resolve instrument on XARM consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput X-ray mirror assembly with the focal length of 5.6 m. Hitomi was launched into orbit in February 2016 and observed several celestial objects, although the operation of Hitomi was terminated in April 2016. The soft X-ray spectrometer (SXS) on Hitomi demonstrated high-resolution X-ray spectroscopy of 5 eV FWHM in orbit for most of the pixels. The Resolve instrument is planned to mostly be a copy of the Hitomi SXS and soft X-ray telescope designs, though several changes are planned based on the lessons learned from Hitomi. We report a brief summary of the SXS performance and the status of the Resolve instrument.

  7. Determination of quenching coefficients by time resolved emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gans, T.; Schulz-von der Gathen, V.; Doebele, H.F. [Essen Univ. (Gesamthochschule) (Germany). Inst. fuer Laser- und Plasmaphysik

    2001-07-01

    Capacitively coupled RF discharges (CCRF discharges) at 13.56 MHz in hydrogen exhibit a field reversal phase of about 10 ns during which an intense electron current provides collisional excitation, within the sheath region. After this strongly dominant short pulsed electron impact excitation, it is possible to determine quenching coefficients from the lifetime of the fluorescence at various pressures by time resolved OES even for high energy levels and without any restrictions of optical selection rules. This novel technique allows the measurement of quenching coefficients for atomic and molecular emission lines of hydrogen itself, as well as for emission lines of small admixtures (e.g. noble gases) to the hydrogen discharge, since with a fast gate-able ICCD camera operating at 13.56 MHz it is possible to measure even faint emission lines temporally resolved.

  8. Determination of quenching coefficients by time resolved emission spectroscopy

    International Nuclear Information System (INIS)

    Gans, T.; Schulz-von der Gathen, V.; Doebele, H.F.

    2001-01-01

    Capacitively coupled RF discharges (CCRF discharges) at 13.56 MHz in hydrogen exhibit a field reversal phase of about 10 ns during which an intense electron current provides collisional excitation, within the sheath region. After this strongly dominant short pulsed electron impact excitation, it is possible to determine quenching coefficients from the lifetime of the fluorescence at various pressures by time resolved OES even for high energy levels and without any restrictions of optical selection rules. This novel technique allows the measurement of quenching coefficients for atomic and molecular emission lines of hydrogen itself, as well as for emission lines of small admixtures (e.g. noble gases) to the hydrogen discharge, since with a fast gate-able ICCD camera operating at 13.56 MHz it is possible to measure even faint emission lines temporally resolved

  9. Resolving Rapid Variation in Energy for Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    Haut, Terry Scot [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Ahrens, Cory Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Jonko, Alexandra [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Till, Andrew Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Lowrie, Robert Byron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division

    2016-08-23

    Resolving the rapid variation in energy in neutron and thermal radiation transport is needed for the predictive simulation capability in high-energy density physics applications. Energy variation is difficult to resolve due to rapid variations in cross sections and opacities caused by quantized energy levels in the nuclei and electron clouds. In recent work, we have developed a new technique to simultaneously capture slow and rapid variations in the opacities and the solution using homogenization theory, which is similar to multiband (MB) and to the finite-element with discontiguous support (FEDS) method, but does not require closure information. We demonstrated the accuracy and efficiency of the method for a variety of problems. We are researching how to extend the method to problems with multiple materials and the same material but with different temperatures and densities. In this highlight, we briefly describe homogenization theory and some results.

  10. Spatially resolved remote measurement of temperature by neutron resonance absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu [Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Kockelmann, W.; Pooley, D.E. [STFC, Rutherford Appleton Laboratory, ISIS Facility, Didcot OX11 0QX (United Kingdom); Feller, W.B. [NOVA Scientific, Inc., 10 Picker Road, Sturbridge, MA 01566 (United States)

    2015-12-11

    Deep penetration of neutrons into most engineering materials enables non-destructive studies of their bulk properties. The existence of sharp resonances in neutron absorption spectra enables isotopically-resolved imaging of elements present in a sample, as demonstrated by previous studies. At the same time the Doppler broadening of resonance peaks provides a method of remote measurement of temperature distributions within the same sample. This technique can be implemented at a pulsed neutron source with a short initial pulse allowing for the measurement of the energy of each registered neutron by the time of flight technique. A neutron counting detector with relatively high timing and spatial resolution is used to demonstrate the possibility to obtain temperature distributions across a 100 µm Ta foil with ~millimeter spatial resolution. Moreover, a neutron transmission measurement over a wide energy range can provide spatially resolved sample information such as temperature, elemental composition and microstructure properties simultaneously.

  11. Space- and time-resolved raman and breakdown spectroscopy: advanced lidar techniques

    Science.gov (United States)

    Silviu, Gurlui; Marius Mihai, Cazacu; Adrian, Timofte; Oana, Rusu; Georgiana, Bulai; Dimitriu, Dan

    2018-04-01

    DARLIOES - the advanced LIDAR is based on space- and time-resolved RAMAN and breakdown spectroscopy, to investigate chemical and toxic compounds, their kinetics and physical properties at high temporal (2 ns) and spatial (1 cm) resolution. The high spatial and temporal resolution are needed to resolve a large variety of chemical troposphere compounds, emissions from aircraft, the self-organization space charges induced light phenomena, temperature and humidity profiles, ice nucleation, etc.

  12. Time-resolved photoelectron spectroscopy and ab initio multiple spawning studies of hexamethylcyclopentadiene

    DEFF Research Database (Denmark)

    Wolf, T. J. A.; Kuhlman, Thomas Scheby; Schalk, O.

    2014-01-01

    Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom.......Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom....

  13. Interrogating the vibrational relaxation of highly excited polyatomics with time-resolved diode laser spectroscopy: C6H6, C6D6, and C6F6+CO2

    International Nuclear Information System (INIS)

    Sedlacek, A.J.; Weston, R.E. Jr.; Flynn, G.W.

    1991-01-01

    The vibrational relaxation of highly excited ground state benzene, benzene d 6 , and hexafluorobenzene by CO 2 has been investigated with high resolution diode laser spectroscopy. The vibrationally hot polyatomics are formed by single photon 248 nm excitation to the S 1 state followed by rapid radiationless transitions. It has been found that in all cases less than 1% of the energy initially present in the polyatomics is deposited into the high frequency mode of CO 2 (ν 3 ). An investigation of the CO 2 (00 0 1) nascent rotational distribution under single collision conditions reveals that very little rotational excitation accompanies vibrational energy transfer to the ν 3 mode. The CO 2 (ν 3 ) rotational states can be described by temperatures, T rot , as follows: C 6 H 6 , T rot =360±30 K; C 6 D 6 , T rot =350±35 K and C 6 F 6 , T rot =340±23 K. An estimate of left-angle ΔE right-angle ν3 , the mean energy transferred to the CO 2 ν 3 mode per collision, suggests that as the availability of low frequency modes in the excited molecule increases, less energy is deposited into the high frequency mode of CO 2 . Finally, evidence is presented suggesting that even at moderate laser fluences, the two-photon ionization of benzene can lead to substantial CO 2 ν 3 excitation via electron+CO 2 inelastic collisions

  14. Resolved resonance parameters for 236Np

    International Nuclear Information System (INIS)

    Morogovskij, G.B.; Bakhanovich, L.A.

    2002-01-01

    Multilevel Breit-Wigner parameters were obtained for fission cross-section representation in the 0.01-33 eV energy region from evaluation of a 236 Np experimental fission cross-section in the resolved resonance region. (author)

  15. Decomposition of time-resolved tomographic PIV

    NARCIS (Netherlands)

    Schmid, P.J.; Violato, D.; Scarano, F.

    2012-01-01

    An experimental study has been conducted on a transitional water jet at a Reynolds number of Re = 5,000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry capturing all relevant spatial and temporal scales. The measured threedimensional flow fields have

  16. Resolving deconvolution ambiguity in gene alternative splicing

    Directory of Open Access Journals (Sweden)

    Hubbell Earl

    2009-08-01

    Full Text Available Abstract Background For many gene structures it is impossible to resolve intensity data uniquely to establish abundances of splice variants. This was empirically noted by Wang et al. in which it was called a "degeneracy problem". The ambiguity results from an ill-posed problem where additional information is needed in order to obtain an unique answer in splice variant deconvolution. Results In this paper, we analyze the situations under which the problem occurs and perform a rigorous mathematical study which gives necessary and sufficient conditions on how many and what type of constraints are needed to resolve all ambiguity. This analysis is generally applicable to matrix models of splice variants. We explore the proposal that probe sequence information may provide sufficient additional constraints to resolve real-world instances. However, probe behavior cannot be predicted with sufficient accuracy by any existing probe sequence model, and so we present a Bayesian framework for estimating variant abundances by incorporating the prediction uncertainty from the micro-model of probe responsiveness into the macro-model of probe intensities. Conclusion The matrix analysis of constraints provides a tool for detecting real-world instances in which additional constraints may be necessary to resolve splice variants. While purely mathematical constraints can be stated without error, real-world constraints may themselves be poorly resolved. Our Bayesian framework provides a generic solution to the problem of uniquely estimating transcript abundances given additional constraints that themselves may be uncertain, such as regression fit to probe sequence models. We demonstrate the efficacy of it by extensive simulations as well as various biological data.

  17. BENCHMARKING THE OPTICAL RESOLVING POWER OF UAV BASED CAMERA SYSTEMS

    Directory of Open Access Journals (Sweden)

    H. Meißner

    2017-08-01

    Full Text Available UAV based imaging and 3D object point generation is an established technology. Some of the UAV users try to address (very highaccuracy applications, i.e. inspection or monitoring scenarios. In order to guarantee such level of detail and accuracy high resolving imaging systems are mandatory. Furthermore, image quality considerably impacts photogrammetric processing, as the tie point transfer, mandatory for forming the block geometry, fully relies on the radiometric quality of images. Thus, empirical testing of radiometric camera performance is an important issue, in addition to standard (geometric calibration, which normally is covered primarily. Within this paper the resolving power of ten different camera/lens installations has been investigated. Selected systems represent different camera classes, like DSLRs, system cameras, larger format cameras and proprietary systems. As the systems have been tested in wellcontrolled laboratory conditions and objective quality measures have been derived, individual performance can be compared directly, thus representing a first benchmark on radiometric performance of UAV cameras. The results have shown, that not only the selection of appropriate lens and camera body has an impact, in addition the image pre-processing, i.e. the use of a specific debayering method, significantly influences the final resolving power.

  18. Angle-resolved diffraction grating biosensor based on porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Changwu; Li, Peng [School of Physical Science and Technology, Xinjiang University, Urumqi 830046 (China); Jia, Zhenhong, E-mail: jzhh@xju.edu.cn; Liu, Yajun; Mo, Jiaqing; Lv, Xiaoyi [College of Information Science and Engineering, Xinjiang University, Urumqi 830046 (China)

    2016-03-07

    In this study, an optical biosensor based on a porous silicon composite structure was fabricated using a simple method. This structure consists of a thin, porous silicon surface diffraction grating and a one-dimensional porous silicon photonic crystal. An angle-resolved diffraction efficiency spectrum was obtained by measuring the diffraction efficiency at a range of incident angles. The angle-resolved diffraction efficiency of the 2nd and 3rd orders was studied experimentally and theoretically. The device was sensitive to the change of refractive index in the presence of a biomolecule indicated by the shift of the diffraction efficiency spectrum. The sensitivity of this sensor was investigated through use of an 8 base pair antifreeze protein DNA hybridization. The shifts of the angle-resolved diffraction efficiency spectrum showed a relationship with the change of the refractive index, and the detection limit of the biosensor reached 41.7 nM. This optical device is highly sensitive, inexpensive, and simple to fabricate. Using shifts in diffraction efficiency spectrum to detect biological molecules has not yet been explored, so this study establishes a foundation for future work.

  19. Resolving the Circumgalactic Medium in the NEPHTHYS Simulations

    Science.gov (United States)

    Richardson, Mark Lawrence Albert; Devriendt, Julien; Slyz, Adrianne; Rosdahl, Karl Joakim; Kimm, Taysun

    2018-01-01

    NEPHTHYS is a RAMSES Cosmological-zoom galaxy simulation suite investigating the impact of stellar feedback (winds, radiation, and type Ia and II SNe) on z > 1 ~L* galaxies and their environments. NEPHTHYS has ~10 pc resolution in the galaxy, where the scales driving star formation and the interaction of stellar feedback with the ISM can begin to be resolved. As outflows, winds, and radiation permeate through the circumgalactic medium (CGM) they can heat or cool gas, and deposit metals throughout the CGM. Such material in the CGM is seen by spectroscopic studies of distant quasars, where CGM gas of foreground galaxies is observed in absorption. It is still unclear what the origin and evolution of this gas is. To help answer this, NEPHTHYS includes additional refinement in the CGM, refining it to an unrivaled 80 pc resolution. I will discuss how this extra resolution is crucial for resolving the complex structure of outflows and accretion in the CGM. Specifically, the metal mass and covering fraction of metals and high energy ions is increased, while the better resolved outflows leads to a decrease in the overall baryon content of galaxy halos, and individual outflow events can have larger velocities. Our results suggest that absorption observations of CGM are tracing a clumpy column of gas with multiple kinematic components.

  20. Highly resolving Rutherford-scattering spectrometry for the study of ZrO{sub 2} layer growth in the beginning stage; Hochaufloesende Rutherford-Streuspektrometrie zur Untersuchung von ZrO{sub 2}-Schichtwachstum im Anfangsstadium

    Energy Technology Data Exchange (ETDEWEB)

    Vieluf, Maik

    2010-06-15

    By means of High Resolution Rutherford Backscattering Spectrometry (HR-RBS) the diffusion behaviour and layer growth of ZrO{sub 2} on SiO{sub 2} and TiN in the initial regime were investigated. The analysis of concentration profiles in ultrathin layers and interfaces was the focus of this work, made possible by the excellent depth resolution of less than 0.3 nm near the surface. For the first time a two-dimensional position sensitive semiconductor detector was implemented and characterized in the setup of the HR-RBS for the improvement of the quality of the measurement results. Furthermore, a measurement procedure was put into operation that allowed the reduction of ion induced damage. Through the optimization of the experimental conditions and the development of a program package for the support of the analyst, an efficient measurement procedure could be routinely ensured. At the time of a binary collision between the incident ion and the target element with a small impact factor, the charge state changes frequently, especially due to the abruptly decreasing ion velocity of the projectile and the overlapping of the electron clouds. For HR-RBS with an energy-separating dipole magnet, the charge state distribution of the scattered ions must be known for the interpretation of the measured spectra. For the first time a significant dependence of the charge state distribution of the scattered C ions on the layer thickness as well as atomic number of the detected target elements, here from the fourth subgroup, was demonstrated. This new knowledge allowed systematic investigations of the ZrO{sub 2} layer growth in the initial regime. The ZrO{sub 2} layers were produced by means of the atomic layer deposition (ALD). Based on the evidence for agglomeration of ZrO{sub 2} on SiO{sub 2} a method was introduced, which takes local thickness variations into account during the simulation of the HR-RBS spectra. An accurate statement about the ZrO{sub 2}/SiO{sub 2} interface was

  1. Easy and unambiguous sequential assignments of intrinsically disordered proteins by correlating the backbone 15N or 13C′ chemical shifts of multiple contiguous residues in highly resolved 3D spectra

    International Nuclear Information System (INIS)

    Yoshimura, Yuichi; Kulminskaya, Natalia V.; Mulder, Frans A. A.

    2015-01-01

    Sequential resonance assignment strategies are typically based on matching one or two chemical shifts of adjacent residues. However, resonance overlap often leads to ambiguity in resonance assignments in particular for intrinsically disordered proteins. We investigated the potential of establishing connectivity through the three-bond couplings between sequentially adjoining backbone carbonyl carbon nuclei, combined with semi-constant time chemical shift evolution, for resonance assignments of small folded and larger unfolded proteins. Extended sequential connectivity strongly lifts chemical shift degeneracy of the backbone nuclei in disordered proteins. We show here that 3D (H)N(COCO)NH and (HN)CO(CO)NH experiments with relaxation-optimized multiple pulse mixing correlate up to seven adjacent backbone amide nitrogen or carbonyl carbon nuclei, respectively, and connections across proline residues are also obtained straightforwardly. Multiple, recurrent long-range correlations with ultra-high resolution allow backbone 1 H N , 15 N H , and 13 C′ resonance assignments to be completed from a single pair of 3D experiments

  2. Capacity Fading Mechanism of the Commercial 18650 LiFePO4-Based Lithium-Ion Batteries: An in Situ Time-Resolved High-Energy Synchrotron XRD Study.

    Science.gov (United States)

    Liu, Qi; Liu, Yadong; Yang, Fan; He, Hao; Xiao, Xianghui; Ren, Yang; Lu, Wenquan; Stach, Eric; Xie, Jian

    2018-02-07

    In situ high-energy synchrotron XRD studies were carried out on commercial 18650 LiFePO 4 cells at different cycles to track and investigate the dynamic, chemical, and structural changes in the course of long-term cycling to elucidate the capacity fading mechanism. The results indicate that the crystalline structural deterioration of the LiFePO 4 cathode and the graphite anode is unlikely to happen before capacity fades below 80% of the initial capacity. Rather, the loss of the active lithium source is the primary cause for the capacity fade, which leads to the appearance of inactive FePO 4 that is proportional to the absence of the lithium source. Our in situ HESXRD studies further show that the lithium-ion insertion and deinsertion behavior of LiFePO 4 continuously changed with cycling. For a fresh cell, the LiFePO 4 experienced a dual-phase solid-solution behavior, whereas with increasing cycle numbers, the dynamic change, which is characteristic of the continuous decay of solid solution behavior, is obvious. The unpredicted dynamic change may result from the morphology evolution of LiFePO 4 particles and the loss of the lithium source, which may be the cause of the decreased rate capability of LiFePO 4 cells after long-term cycling.

  3. Time-resolved brightness measurements by streaking

    Science.gov (United States)

    Torrance, Joshua S.; Speirs, Rory W.; McCulloch, Andrew J.; Scholten, Robert E.

    2018-03-01

    Brightness is a key figure of merit for charged particle beams, and time-resolved brightness measurements can elucidate the processes involved in beam creation and manipulation. Here we report on a simple, robust, and widely applicable method for the measurement of beam brightness with temporal resolution by streaking one-dimensional pepperpots, and demonstrate the technique to characterize electron bunches produced from a cold-atom electron source. We demonstrate brightness measurements with 145 ps temporal resolution and a minimum resolvable emittance of 40 nm rad. This technique provides an efficient method of exploring source parameters and will prove useful for examining the efficacy of techniques to counter space-charge expansion, a critical hurdle to achieving single-shot imaging of atomic scale targets.

  4. Deflection evaluation using time-resolved radiography

    International Nuclear Information System (INIS)

    Fry, D.A.; Lucero, J.P.

    1990-01-01

    Time-resolved radiography is the creation of an x-ray image for which both the start-exposure and stop-exposure times are known with respect to the event under study. The combination of image and timing are used to derive information about the event. The authors have applied time-resolved radiography to evaluate motions of explosive-driven events. In the particular application discussed in this paper, the author's intent is to measure maximum deflections of the components involved. Exposures are made during the time just before to just after the event of interest occurs. A smear or blur of motion out to its furthest extent is recorded on the image. Comparison of the dynamic images with static images allows deflection measurements to be made

  5. Reverse Universal Resolving Algorithm and inverse driving

    DEFF Research Database (Denmark)

    Pécseli, Thomas

    2012-01-01

    Inverse interpretation is a semantics based, non-standard interpretation of programs. Given a program and a value, an inverse interpreter finds all or one of the inputs, that would yield the given value as output with normal forward evaluation. The Reverse Universal Resolving Algorithm is a new...... variant of the Universal Resolving Algorithm for inverse interpretation. The new variant outperforms the original algorithm in several cases, e.g., when unpacking a list using inverse interpretation of a pack program. It uses inverse driving as its main technique, which has not been described in detail...... before. Inverse driving may find application with, e.g., supercompilation, thus suggesting a new kind of program inverter....

  6. 238U + n resolved resonance energies

    International Nuclear Information System (INIS)

    Olsen, D.K.; de Saussure, G.; Perez, R.B.; Difilippo, F.C.; Ingle, R.W.

    1978-01-01

    Neutron transmission measurements from 100 eV to 170 keV at 150 m through four 238 U samples are reported. The energy calibration is described, and the resultant 233 U resolved resonance energies are found to be intermediate between those from other workers. In addition, some energies for sharp resonances in 23 Na, 27 Al, 32 S, and 206 Pb are given

  7. Generalized Darcy–Oseen resolvent problem

    Czech Academy of Sciences Publication Activity Database

    Medková, Dagmar; Ptashnyk, M.; Varnhorn, W.

    2016-01-01

    Roč. 39, č. 6 (2016), s. 1621-1630 ISSN 0170-4214 Institutional support: RVO:67985840 Keywords : Darcy-Oseen resolvent problem * semipermeable membrane * Brinkman-Darcy equations * fluid flow between free-fluid domains and porous media Subject RIV: BA - General Mathematics Impact factor: 1.017, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/mma.3872/abstract

  8. On marginally resolved objects in optical interferometry

    Science.gov (United States)

    Lachaume, R.

    2003-03-01

    With the present and soon-to-be breakthrough of optical interferometry, countless objects shall be within reach of interferometers; yet, most of them are expected to remain only marginally resolved with hectometric baselines. In this paper, we tackle the problem of deriving the properties of a marginally resolved object from its optical visibilities. We show that they depend on the moments of flux distribution of the object: centre, mean angular size, asymmetry, and curtosis. We also point out that the visibility amplitude is a second-order phenomenon, whereas the phase is a combination of a first-order term, giving the location of the photocentre, and a third-order term, more difficult to detect than the visibility amplitude, giving an asymmetry coefficient of the object. We then demonstrate that optical visibilities are not a good model constraint while the object stays marginally resolved, unless observations are carried out at different wavelengths. Finally, we show an application of this formalism to circumstellar discs.

  9. State resolved vibrational relaxation modeling for strongly nonequilibrium flows

    Science.gov (United States)

    Boyd, Iain D.; Josyula, Eswar

    2011-05-01

    Vibrational relaxation is an important physical process in hypersonic flows. Activation of the vibrational mode affects the fundamental thermodynamic properties and finite rate relaxation can reduce the degree of dissociation of a gas. Low fidelity models of vibrational activation employ a relaxation time to capture the process at a macroscopic level. High fidelity, state-resolved models have been developed for use in continuum gas dynamics simulations based on computational fluid dynamics (CFD). By comparison, such models are not as common for use with the direct simulation Monte Carlo (DSMC) method. In this study, a high fidelity, state-resolved vibrational relaxation model is developed for the DSMC technique. The model is based on the forced harmonic oscillator approach in which multi-quantum transitions may become dominant at high temperature. Results obtained for integrated rate coefficients from the DSMC model are consistent with the corresponding CFD model. Comparison of relaxation results obtained with the high-fidelity DSMC model shows significantly less excitation of upper vibrational levels in comparison to the standard, lower fidelity DSMC vibrational relaxation model. Application of the new DSMC model to a Mach 7 normal shock wave in carbon monoxide provides better agreement with experimental measurements than the standard DSMC relaxation model.

  10. A minimally-resolved immersed boundary model for reaction-diffusion problems

    OpenAIRE

    Pal Singh Bhalla, A; Griffith, BE; Patankar, NA; Donev, A

    2013-01-01

    We develop an immersed boundary approach to modeling reaction-diffusion processes in dispersions of reactive spherical particles, from the diffusion-limited to the reaction-limited setting. We represent each reactive particle with a minimally-resolved "blob" using many fewer degrees of freedom per particle than standard discretization approaches. More complicated or more highly resolved particle shapes can be built out of a collection of reactive blobs. We demonstrate numerically that the blo...

  11. Ultrafast time-resolved spectroscopy of lead halide perovskite films

    Science.gov (United States)

    Idowu, Mopelola A.; Yau, Sung H.; Varnavski, Oleg; Goodson, Theodore

    2015-09-01

    Recently, lead halide perovskites which are organic-inorganic hybrid structures, have been discovered to be highly efficient as light absorbers. Herein, we show the investigation of the excited state dynamics and emission properties of non-stoichiometric precursor formed lead halide perovskites grown by interdiffusion method using steady-state and time-resolved spectroscopic measurements. The influence of the different ratios of the non-stoichiometric precursor solution was examined. The observed photoluminescence properties were correlated with the femtosecond transient absorption measurements.

  12. Time-Resolved Hard X-Ray Spectrometer

    International Nuclear Information System (INIS)

    Kenneth Moya; Ian McKennaa; Thomas Keenana; Michael Cuneob

    2007-01-01

    Wired array studies are being conducted at the SNL Z accelerator to maximize the x-ray generation for inertial confinement fusion targets and high energy density physics experiments. An integral component of these studies is the characterization of the time-resolved spectral content of the x-rays. Due to potential spatial anisotropy in the emitted radiation, it is also critical to diagnose the time-evolved spectral content in a space-resolved manner. To accomplish these two measurement goals, we developed an x-ray spectrometer using a set of high-speed detectors (silicon PIN diodes) with a collimated field-of-view that converged on a 1-cm-diameter spot at the pinch axis. Spectral discrimination is achieved by placing high Z absorbers in front of these detectors. We built two spectrometers to permit simultaneous different angular views of the emitted radiation. Spectral data have been acquired from recent Z shots for the radial and polar views. UNSPEC1 has been adapted to analyze and unfold the measured data to reconstruct the x-ray spectrum. The unfold operator code, UFO2, is being adapted for a more comprehensive spectral unfolding treatment

  13. Time-resolved materials science opportunities using synchrotron x-ray sources

    International Nuclear Information System (INIS)

    Larson, B.C.; Tischler, J.Z.

    1995-06-01

    The high brightness, high intensity, and pulsed time-structure of synchrotron sources provide new opportunities for time-resolved x-ray diffraction investigations. With third generation synchrotron sources coming on line, high brilliance and high brightness are now available in x-ray beams with the highest flux. In addition to the high average flux, the instantaneous flux available in synchrotron beams is greatly enhanced by the pulsed time structure, which consists of short bursts of x-rays that are separated by ∼tens to hundreds of nanoseconds. Time-resolved one- and two-dimensional position sensitive detection techniques that take advantage of synchrotron radiation for materials science x-ray diffraction investigations are presented, and time resolved materials science applications are discussed in terms of recent diffraction and spectroscopy results and materials research opportunities

  14. Photoelectron spectrometer for high-resolution angular resolved studies

    International Nuclear Information System (INIS)

    Parr, A.C.; Southworth, S.H.; Dehmer, J.L.; Holland, D.M.P.

    1982-01-01

    We report on a new electron spectrometer system designed for use on storage-ring light sources. The system features a large (76 cm dia. x 92 cm long) triply magnetically shielded vacuum chamber and two 10.2 cm mean radius hemispherical electron-energy analyzers. One of the analyzers is fixed and the other is rotatable through about 150 0 . The chamber is pumped by a cryopump and a turbomolecular pump combination so as to enable experiments with a variety of gases under different conditions. The light detection includes both a direct beam monitor and polarization analyzer. The electron detection is accomplished with either a continuous-channel electron multiplier or with multichannel arrays used as area detectors

  15. Resolving controversy of unusually high refractive index of a tubulin

    Czech Academy of Sciences Publication Activity Database

    Krivosudský, Ondřej; Dráber, Petr; Cifra, Michal

    2017-01-01

    Roč. 117, č. 3 (2017), č. článku 38003. ISSN 0295-5075 R&D Projects: GA ČR(CZ) GA15-17102S; GA ČR GA16-25159S Grant - others:AV ČR(CZ) SAV-15-22 Program:Bilaterální spolupráce Institutional support: RVO:67985882 ; RVO:68378050 Keywords : protein * resonance * microtubules Subject RIV: BH - Optics, Masers, Lasers; EB - Genetics ; Molecular Biology (UMG-J) OBOR OECD: Optics (including laser optics and quantum optics); Developmental biology (UMG-J) Impact factor: 1.957, year: 2016

  16. Highly Resolved Measurements of a Developing Strong Collisional Plasma Shock

    Science.gov (United States)

    Rinderknecht, Hans G.; Park, H.-S.; Ross, J. S.; Amendt, P. A.; Higginson, D. P.; Wilks, S. C.; Haberberger, D.; Katz, J.; Froula, D. H.; Hoffman, N. M.; Kagan, G.; Keenan, B. D.; Vold, E. L.

    2018-03-01

    The structure of a strong collisional shock front forming in a plasma is directly probed for the first time in laser-driven gas-jet experiments. Thomson scattering of a 526.5 nm probe beam was used to diagnose temperature and ion velocity distribution in a strong shock (M ˜11 ) propagating through a low-density (ρ ˜0.01 mg /cc ) plasma composed of hydrogen. A forward-streaming population of ions traveling in excess of the shock velocity was observed to heat and slow down on an unmoving, unshocked population of cold protons, until ultimately the populations merge and begin to thermalize. Instabilities are observed during the merging, indicating a uniquely plasma-phase process in shock front formation.

  17. Time-resolved studies. Ch. 9

    International Nuclear Information System (INIS)

    Mills, Dennis M.; Argonne National Lab., IL

    1991-01-01

    Synchrotron radiation, with its unique properties, offers a tool to extend X-ray measurements from the static to the time-resolved regime. The most straight-forward application of synchrotron radiation to the study of transient phenomena is directly through the possibility of decreased data-collection times via the enormous increase in flux over that of a laboratory X-ray system. Even further increases in intensity can be obtained through the use of novel X-ray optical devices. Wide-bandpass monochromators, e.g., that utilize the continuous spectral distribution of synchrotron radiation, can increase flux on the sample several orders of magnitude over conventional X-ray optical systems thereby allowing a further shortening of the data-collection time. Another approach that uses the continuous spectral nature of synchrotron radiation to decrease data-collection times is the 'parallel data collection' method. Using this technique, intensities as a function of X-ray energy are recorded simultaneously for all energies rather than sequentially recording data at each energy, allowing for a dramatic decrease in data-collection time. Perhaps the most exciting advances in time-resolved X-ray studies will be made by those methods that exploit the pulsed nature of the radiation emitted from storage rings. Pulsed techniques have had an enormous impact in the study of the temporal evolution of transient phenomena. The extension from continuous to modulated sources for use in time-resolved work has been carried over in a host of fields that use both pulsed particle and pulsed electro-magnetic beams. In this chapter the new experimental techniques are reviewed and illustrated with some experiments. (author). 98 refs.; 20 figs.; 5 tabs

  18. Achieving patient satisfaction: resolving patient complaints.

    Science.gov (United States)

    Oxler, K F

    1997-07-01

    Patients demand to be active participants on and partners with the health care team to design their care regimen. Patients bring unique perceptions and expectations and use these to evaluate service quality and satisfaction. If customer satisfaction is not achieved and a patient complaint results, staff must have the skills to respond and launch a service recovery program. Service recovery, when done with style and panache, can retain loyal customers. Achieving patient satisfaction and resolving patient complaints require commitment from top leadership and commitment from providers to dedicate the time to understand their patients' needs.

  19. Spatially Resolved Analysis of Bragg Selectivity

    Directory of Open Access Journals (Sweden)

    Tina Sabel

    2015-11-01

    Full Text Available This paper targets an inherent control of optical shrinkage in photosensitive polymers, contributing by means of spatially resolved analysis of volume holographic phase gratings. Point by point scanning of the local material response to the Gaussian intensity distribution of the recording beams is accomplished. Derived information on the local grating period and grating slant is evaluated by mapping of optical shrinkage in the lateral plane as well as through the depth of the layer. The influence of recording intensity, exposure duration and the material viscosity on the Bragg selectivity is investigated.

  20. Periodicity in Age-Resolved Populations

    Science.gov (United States)

    Esipov, Sergei

    We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

  1. Annually resolved atmospheric radiocarbon records reconstructed from tree-rings

    Science.gov (United States)

    Wacker, Lukas; Bleicher, Niels; Büntgen, Ulf; Friedrich, Michael; Friedrich, Ronny; Diego Galván, Juan; Hajdas, Irka; Jull, Anthony John; Kromer, Bernd; Miyake, Fusa; Nievergelt, Daniel; Reinig, Frederick; Sookdeo, Adam; Synal, Hans-Arno; Tegel, Willy; Wesphal, Torsten

    2017-04-01

    The IntCal13 calibration curve is mainly based on data measured by decay counting with a resolution of 10 years. Thus high frequency changes like the 11-year solar cycles or cosmic ray events [1] are not visible, or at least not to their full extent. New accelerator mass spectrometry (AMS) systems today are capable of measuring at least as precisely as decay counters [2], with the advantage of using 1000 times less material. The low amount of material required enables more efficient sample preparation. Thus, an annually resolved re-measurement of the tree-ring based calibration curve can now be envisioned. We will demonstrate with several examples the multitude of benefits resulting from annually resolved radiocarbon records from tree-rings. They will not only allow for more precise radiocarbon dating but also contain valuable new astrophysical information. The examples shown will additionally indicate that it can be critical to compare AMS measurements with a calibration curve that is mainly based on decay counting. We often see small offsets between the two measurement techniques, while the reason is yet unknown. [1] Miyake F, Nagaya K, Masuda K, Nakamura T. 2012. A signature of cosmic-ray increase in AD 774-775 from tree rings in Japan. Nature 486(7402):240-2. [2] Wacker L, Bonani G, Friedrich M, Hajdas I, Kromer B, Nemec M, Ruff M, Suter M, Synal H-A, Vockenhuber C. 2010. MICADAS: Routine and high-precision radiocarbon dating. Radiocarbon 52(2):252-62.

  2. Rapid Spontaneously Resolving Acute Subdural Hematoma

    Science.gov (United States)

    Gan, Qi; Zhao, Hexiang; Zhang, Hanmei; You, Chao

    2017-01-01

    Introduction: This study reports a rare patient of a rapid spontaneously resolving acute subdural hematoma. In addition, an analysis of potential clues for the phenomenon is presented with a review of the literature. Patient Presentation: A 1-year-and-2-month-old boy fell from a height of approximately 2 m. The patient was in a superficial coma with a Glasgow Coma Scale of 8 when he was transferred to the authors’ hospital. Computed tomography revealed the presence of an acute subdural hematoma with a midline shift beyond 1 cm. His guardians refused invasive interventions and chose conservative treatment. Repeat imaging after 15 hours showed the evident resolution of the hematoma and midline reversion. Progressive magnetic resonance imaging demonstrated the complete resolution of the hematoma, without redistribution to a remote site. Conclusions: Even though this phenomenon has a low incidence, the probability of a rapid spontaneously resolving acute subdural hematoma should be considered when patients present with the following characteristics: children or elderly individuals suffering from mild to moderate head trauma; stable or rapidly recovered consciousness; and simple acute subdural hematoma with a moderate thickness and a particularly low-density band in computed tomography scans. PMID:28468224

  3. Healthcare Teams Neurodynamically Reorganize When Resolving Uncertainty

    Directory of Open Access Journals (Sweden)

    Ronald Stevens

    2016-11-01

    Full Text Available Research on the microscale neural dynamics of social interactions has yet to be translated into improvements in the assembly, training and evaluation of teams. This is partially due to the scale of neural involvements in team activities, spanning the millisecond oscillations in individual brains to the minutes/hours performance behaviors of the team. We have used intermediate neurodynamic representations to show that healthcare teams enter persistent (50–100 s neurodynamic states when they encounter and resolve uncertainty while managing simulated patients. Each of the second symbols was developed situating the electroencephalogram (EEG power of each team member in the contexts of those of other team members and the task. These representations were acquired from EEG headsets with 19 recording electrodes for each of the 1–40 Hz frequencies. Estimates of the information in each symbol stream were calculated from a 60 s moving window of Shannon entropy that was updated each second, providing a quantitative neurodynamic history of the team’s performance. Neurodynamic organizations fluctuated with the task demands with increased organization (i.e., lower entropy occurring when the team needed to resolve uncertainty. These results show that intermediate neurodynamic representations can provide a quantitative bridge between the micro and macro scales of teamwork.

  4. Time Resolved Deposition Measurements in NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Roquemore, A.L.; Hogan, J.; Wampler, W.R.

    2004-01-01

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm 2 of deposition, however surprisingly, 15.9 (micro)g/cm 2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm 2 matched the mass of 13.5 (micro)g/cm 2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

  5. RESOLVE: Bridge between early lunar ISRU and science objectives

    Science.gov (United States)

    Taylor, G.; Sanders, G.; Larson, W.; Johnson, K.

    2007-08-01

    interstellar volatiles from cold molecular clouds. These sources leave distinctive signatures, many detectable by RESOLVE. Comet impacts are likely to produce coherent layers of ice (probably reduced to pebbles and boulders by subsequent small impacts, and buried); these would be detected by imaging and Raman spectroscopy, the high water (H2O) signal measured by the GC, and possibly by changes in the drilling rate or torque. More continuous delivery mechanism theories would not produce layers or boulders of ice, but might bond regolith grains together. Continuous sources might be distinguished by H/H2O ratios and the abundances of other volatiles. Hydrogen isotopic composition would provide additional important information because these sources have distinctive D/H ratios, so one enhancement to RESOLVE would be an incorporation of a mass spectrometer with the existing GC. Reactions in the Polar Regolith: Billions of years of micrometeorite bombardment, irradiation by cosmic rays and interstellar Lyman-alpha ultraviolet, and the presence of carbon-, hydrogen-, oxygen-, and nitrogen-bearing volatiles might have led to the production of organic compounds, a process that has been demonstrated experimentally. Heating by micrometeorite impacts might drive reactions involving water to produce phyllosilicates (clay minerals). If abundant enough, these reaction products could be observable by Raman spectroscopy and GC analysis. Thus, the polar cold traps are natural laboratories for the study of processes operating in interstellar space, and the RESOLVE suite of instruments can shed light on those processes.

  6. An IPSN research programme to resolve pending LOCA issues

    International Nuclear Information System (INIS)

    Mailliat, A.; Grandjean, C.; Clement, B.

    2001-01-01

    Studies performed in IPSN and elsewhere pointed out that high burnup may induce specific effects under LOCA conditions, especially those related with fuel relocation. Uncertainties exist regarding how much these effects might affect the late evolution of the accident transient and the associated safety issues. IPSN estimates that a better knowledge of specific phenomena is required in order to resolve the pending uncertainties related to LOCA criteria. IPSN is preparing the so called APRP-Irradie (High Burnup fuel LOCA) programme. One of the important aspect of this programme is in-pile experiments involving bundle geometries in the PHEBUS facility located at Cadarache, France. A feasibility study for such an experimental programme is underway and should provide soon, a finalized project including cost and schedule aspects. (authors)

  7. Atomic column resolved electron energy-loss spectroscopy

    International Nuclear Information System (INIS)

    Duscher, G.; Pennycook, S.J.; Browning, N.D.

    1998-01-01

    Spatially resolved electron energy-loss spectroscopy (EELS) is rapidly developing into a unique and powerful tool to characterize internal interfaces. Because atomic column resolved Z-contrast imaging can be performed simultaneously with EELS in the scanning transmission electron microscope, this combination allows the atomic structure to be correlated with the electronic structure, and thus the local properties of interfaces or defects can be determined directly. However, the ability to characterize interfaces and defects at that level requires not only high spatial resolution but also the exact knowledge of the beam location, from where the spectrum is obtained. Here we discuss several examples progressing from cases where the limitation in spatial resolution is given by the microscopes or the nature of the sample, to one example of impurity atoms at a grain boundary, which show intensity and fine structure changes from atomic column to atomic column. Such data can be interpreted as changes in valence of the impurity, depending on its exact site in the boundary plane. Analysis ofthis nature is a valuable first step in understanding the microscopic structural, optical and electronic properties of materials. (orig.)

  8. A novel multiplex absorption spectrometer for time-resolved studies

    Science.gov (United States)

    Lewis, Thomas; Heard, Dwayne E.; Blitz, Mark A.

    2018-02-01

    A Time-Resolved Ultraviolet/Visible (UV/Vis) Absorption Spectrometer (TRUVAS) has been developed that can simultaneously monitor absorption at all wavelengths between 200 and 800 nm with millisecond time resolution. A pulsed photolysis laser (KrF 248 nm) is used to initiate chemical reactions that create the target species. The absorption signals from these species evolve as the composition of the gas in the photolysis region changes over time. The instrument can operate at pressures over the range ˜10-800 Torr and can measure time-resolved absorbances systems (in particular the Herriott cell), there are fundamental differences, most notably the ability to adjust each mirror to maximise the overlap between the probe beam and the photolysis laser. Another feature which aids the sensitivity and versatility of the system is the use of 2 high-throughput spectrographs coupled with sensitive line-array CCDs, which can measure absorbance from ˜200 to 800 nm simultaneously. The capability of the instrument is demonstrated via measurements of the absorption spectrum of the peroxy radical, HOCH2CH2O2, and its self-reaction kinetics.

  9. Time-resolved Laue diffraction from protein crystals: Instrumental considerations

    International Nuclear Information System (INIS)

    Bilderback, D.H.; Cornell Univ., Ithaca, NY; Moffat, K.; Szebenyi, D.M.E.

    1984-01-01

    A serious limitation of macromolecular crystallography has been its inability to determine changes in structure on a biochemical time scale of milliseconds or less. Recently, we have shown that X-ray exposures on single crystals of macromolecules may be obtained in the millisecond time range through the use of intense, polychromatic radiation with Δlambda/lambda approx.= 0.2 derived from the Cornell High Energy Synchrotron Source, CHESS. Such radiation falling on a stationary crystal yields a Laue diffraction pattern, in which almost all Laue reflections arise from a unique set of Miller indices and where their intensities are automatically integrated over wavelength. This Laue technique requires wide band pass optics, which may be obtained by a combination of reflection and transmission mirrors, filters or layered synthetic microstructures. Time-resolved macromolecular crystallography may be achieved by several data collection schemes: 'one-shot' recording coupled to a simple streak camera, repetitive sample perturbation coupled to a detector with temporal resolution and repetitive perturbation which uses the synchrotron pulses for stroboscopic triggering and detection. These schemes are appropriate for different time scales, roughly the milli-, micro- and nanosecond regimes. It appears that time-resolved crystallography is entirely feasible, with an ultimate time resolution limited only by the length of a synchrotron light pulse, some 150 ps at CHESS. (orig.)

  10. Recent advances in component resolved diagnosis in food allergy

    Directory of Open Access Journals (Sweden)

    Magnus P. Borres

    2016-10-01

    Full Text Available Due to the high prevalence of food allergic diseases globally there are increasing demands in clinical practice for managing IgE-mediated conditions. During the last decade, component resolved diagnostics has been introduced into the field of clinical allergology, providing information that cannot be obtained from extract-based tests. Component resolved data facilitate more precise diagnosis of allergic diseases and identify sensitizations attributable to cross-reactivity. Furthermore it assists risk assessment in clinical practice as sensitization to some allergenic molecules is related to persistence of clinical symptoms and systemic rather than local reactions. The information may also aid the clinician in prescription of oral immunotherapy (OIT in patients with severe symptoms, and in giving advice on food allergen avoidance or on the need to perform food challenges. The use of allergen components is rapidly evolving and increases our possibility to treat food allergic patients with a more individual approach. Using molecular allergology, we can already now better diagnose, prognose and grade the food allergy. In summary, daily routine molecular allergy diagnostics offers a number of benefits that give us a higher diagnostic precision and allow for better management of the patient.

  11. Femtosecond time-resolved transient absorption spectroscopy of xanthophylls.

    Science.gov (United States)

    Niedzwiedzki, Dariusz M; Sullivan, James O; Polívka, Tomás; Birge, Robert R; Frank, Harry A

    2006-11-16

    Xanthophylls are a major class of photosynthetic pigments that participate in an adaptation mechanism by which higher plants protect themselves from high light stress. In the present work, an ultrafast time-resolved spectroscopic investigation of all the major xanthophyll pigments from spinach has been performed. The molecules are zeaxanthin, lutein, violaxanthin, and neoxanthin. beta-Carotene was also studied. The experimental data reveal the inherent spectral properties and ultrafast dynamics including the S(1) state lifetimes of each of the pigments. In conjunction with quantum mechanical computations the results address the molecular features of xanthophylls that control the formation and decay of the S* state in solution. The findings provide compelling evidence that S* is an excited state with a conformational geometry twisted relative to the ground state. The data indicate that S* is formed via a branched pathway from higher excited singlet states and that its yield depends critically on the presence of beta-ionylidene rings in the polyene system of pi-electron conjugated double bonds. The data are expected to be beneficial to researchers employing ultrafast time-resolved spectroscopic methods to investigate the mechanisms of both energy transfer and nonphotochemical quenching in higher plant preparations.

  12. Time-resolved suprathermal x-rays

    International Nuclear Information System (INIS)

    Lee, P.H.Y.; Rosen, M.D.

    1978-01-01

    Temporally resolved x-ray spectra in the range of 1 to 20 keV have been obtained from gold disk targets irradiated by 1.06 μm laser pulses from the Argus facility. The x-ray streak camera used for the measurement has been calibrated for streak speed and dynamic range by using an air-gap Fabry-Perot etalon, and the instrument response has been calibrated using a multi-range monoenergetic x-ray source. The experimental results indicate that we are able to observe the ''hot'' x-ray temperature evolve in time and that the experimentally observed values can be qualitatively predicted by LASNEX code computations when the inhibited transport model is used

  13. Time-resolved measurements of luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Collier, Bradley B. [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); McShane, Michael J., E-mail: mcshane@tamu.edu [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); Materials Science and Engineering Program, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States)

    2013-12-15

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described.

  14. Time-resolved measurements of luminescence

    International Nuclear Information System (INIS)

    Collier, Bradley B.; McShane, Michael J.

    2013-01-01

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described

  15. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  16. Resolvent-Techniques for Multiple Exercise Problems

    International Nuclear Information System (INIS)

    Christensen, Sören; Lempa, Jukka

    2015-01-01

    We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples

  17. Resolvent-Techniques for Multiple Exercise Problems

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Sören, E-mail: christensen@math.uni-kiel.de [Christian–Albrechts-University in Kiel, Mathematical Institute (Germany); Lempa, Jukka, E-mail: jukka.lempa@hioa.no [Oslo and Akershus University College, School of business, Faculty of Social Sciences (Norway)

    2015-02-15

    We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples.

  18. Spatially resolved spectroscopy on semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Roessler, Johanna

    2009-02-20

    Cleared edge overgrowth (CEO) nanostructures are identified and studied by 1D und 2D {mu}PL mapping scans and by time-resolved and power-dependent measurements. Distinct excitonic ground states of 2fold CEO QDs with large localization energies are achieved. The deeper localization reached as compared to the only other report on 2fold CEO QDs in literature is attributed to a new strain-free fabrication process and changed QW thickness in [001] growth. In order to achieve controlled manipulation of 2fold CEO QDs the concept of a CEO structure with three top gates and one back gate is presented. Due to the complexity of this device, a simpler test structure is realized. Measurements on this test structure confirm the necessity to either grow significantly thicker overgrowth layers or to provide separate top gates in all three spatial direction to controllably manipulate 2fold CEO QDs with an external electric field. (orig.)

  19. Time-resolved and position-resolved X-ray spectrometry with a pixelated detector

    Energy Technology Data Exchange (ETDEWEB)

    Sievers, Peter

    2012-12-07

    show a good agreement. Up to now the measurements of impinging spectra with a Timepix detector have been performed in radiation fields with a relatively high fluence. To cope with the requirement of measuring in radiation fields with a low fluence, there had to be changes in the method of analysis compared to those performed formerly. An important improvement in this context was the employment of the Bayesian deconvolution method. The spectra reconstructed with this method were then compared to the results of two different and established detection systems. Firstly, the shape of the deconvolved spectrum was compared to the one measured with a hpGe detector. Secondly, the calculated value of the kerma rate was compared to the one measured with an ionization chamber. This gave an estimate on the correctness of the absolute number of photons. Both comparisons have shown a good agreement and thus I was able to validate that the method delivers precise results. Compared to the formerly used spectrum-stripping method the Bayesian deconvolution turned out to be very stable and reliable. This robustness of the deconvolution method and the development of a pixel-by-pixel energy calibration were the keys towards position-resolved spectrometry. With such a precise energy calibration the energy resolution was enhanced by up to 45%. This improved accuracy in the measurement has been very demanding on the improvements of the simulation of the response matrix needed for deconvolution. Both this enhanced simulation and a pixel-by-pixel calibrated detector opened the possibility of measuring the anode heel effect. Not only the relative angular dependency of the spectrum emitted but also the change in the absolute photon fluence were measured. Furthermore, it is possible to even use small ROIs down to 4x4 pixels to evaluate a spectrum. This was then applied for the spectrometry of small focal spots of a miniature X-ray source used in therapeutics. Furthermore, the robustness and the

  20. Time-resolved and position-resolved X-ray spectrometry with a pixelated detector

    International Nuclear Information System (INIS)

    Sievers, Peter

    2012-01-01

    show a good agreement. Up to now the measurements of impinging spectra with a Timepix detector have been performed in radiation fields with a relatively high fluence. To cope with the requirement of measuring in radiation fields with a low fluence, there had to be changes in the method of analysis compared to those performed formerly. An important improvement in this context was the employment of the Bayesian deconvolution method. The spectra reconstructed with this method were then compared to the results of two different and established detection systems. Firstly, the shape of the deconvolved spectrum was compared to the one measured with a hpGe detector. Secondly, the calculated value of the kerma rate was compared to the one measured with an ionization chamber. This gave an estimate on the correctness of the absolute number of photons. Both comparisons have shown a good agreement and thus I was able to validate that the method delivers precise results. Compared to the formerly used spectrum-stripping method the Bayesian deconvolution turned out to be very stable and reliable. This robustness of the deconvolution method and the development of a pixel-by-pixel energy calibration were the keys towards position-resolved spectrometry. With such a precise energy calibration the energy resolution was enhanced by up to 45%. This improved accuracy in the measurement has been very demanding on the improvements of the simulation of the response matrix needed for deconvolution. Both this enhanced simulation and a pixel-by-pixel calibrated detector opened the possibility of measuring the anode heel effect. Not only the relative angular dependency of the spectrum emitted but also the change in the absolute photon fluence were measured. Furthermore, it is possible to even use small ROIs down to 4x4 pixels to evaluate a spectrum. This was then applied for the spectrometry of small focal spots of a miniature X-ray source used in therapeutics. Furthermore, the robustness and the

  1. Femtosecond Time-Resolved Resonance-Enhanced CARS of Gaseous Iodine at Room Temperature

    International Nuclear Information System (INIS)

    He Ping; Fan Rong-Wei; Xia Yuan-Qin; Yu Xin; Chen De-Ying; Yao Yong

    2011-01-01

    Time-resolved resonance-enhanced coherent anti-Stokes Raman scattering (CARS) is applied to investigate molecular dynamics in gaseous iodine. 40 fs laser pulses are applied to create and monitor the high vibrational states of iodine at room temperature (corresponding to a vapor pressure as low as about 35 Pa) by femtosecond time-resolved CARS. Depending on the time delay between the probe pulse and the pump/Stokes pulse pairs, the high vibrational states both on the electronically ground states and the excited states can be detected as oscillations in the CARS transient signal. It is proved that the femtosecond time-resolved CARS technique is a promising candidate for investigating the molecular dynamics of a low concentration system and can be applied to environmental and atmospheric monitoring measurements. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Angle-resolved photoemission spectroscopy on iron-chalcogenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Maletz, Janek; Zabolotnyy, Volodymyr; Evtushinsky, Daniil; Thirupathaiah, Setti; Wolter-Giraud, Anja; Harnagea, Luminita; Kordyuk, Alexander; Borisenko, Sergey [IFW Dresden (Germany); Yaresko, Alexander [MPI-FKF, Stuttgart (Germany); Vasiliev, Alexander [Moscow State University (Russian Federation); Chareev, Dimitri [RAS, Chernogolovka (Russian Federation); Rienks, Emile [Helmholtz-Zentrum Berlin (Germany); Buechner, Bernd [IFW Dresden (Germany); TU Dresden (Germany); Shermadini, Zurab; Luetkens, Hubertus; Sedlak, Kamil; Khasanov, Rustem; Amato, Alex; Krzton-Maziopa, Anna; Conder, Kazimierz; Pomjakushina, Ekaterina [Paul Scherrer Institute (Switzerland); Klauss, Hans-Henning [TU Dresden (Germany)

    2014-07-01

    The electronic structure of the iron chalcogenide superconductors FeSe{sub 1-x} and Rb{sub 0.77}Fe{sub 1.61}Se{sub 2} was investigated by high-resolution angle-resolved photoemission spectroscopy (ARPES). The results were compared to DFT calculations and μSR measurements. Both compounds share ''cigar-shaped'' Fermi surface sheets in their electronic structure, that can be found in almost all iron-pnictide superconductors. These features originate from a strong interplay of two hole- and electron-like bands in the Brillouin zone center, leading to a pronounced singularity in the density of states just below the Fermi level. This facilitates the coupling to a bosonic mode responsible for superconductivity.

  3. Resolving ultrafast exciton migration in organic solids at the nanoscale

    Science.gov (United States)

    Ginsberg, Naomi

    The migration of Frenkel excitons, tightly-bound electron-hole pairs, in photosynthesis and in organic semiconducting films is critical to the efficiency of natural and artificial light harvesting. While these materials exhibit a high degree of structural heterogeneity on the nanoscale, traditional measurements of exciton migration lengths are performed on bulk samples. Since both the characteristic length scales of structural heterogeneity and the reported bulk diffusion lengths are smaller than the optical diffraction limit, we adapt far-field super-resolution fluorescence imaging to uncover the correlations between the structural and energetic landscapes that the excitons explore. By combining the ultrafast super-resolved measurements with exciton hopping simulations we furthermore specify the nature (in addition to the extent) of exciton migration as a function of the intrinsic and ensemble chromophore energy scales that determine a spatio-energetic landscape for migration. In collaboration with: Samuel Penwell, Lucas Ginsberg, University of California, Berkeley and Rodrigo Noriega University of Utah.

  4. Compton polarimetry with position-resolving X-ray detectors

    International Nuclear Information System (INIS)

    Hess, Sebastian

    2010-02-01

    In the present thesis the prototype of a novel position-resolving and multi-hit able 2D Si(Li) strip detector is characterized, the planar detector crystal of which is simultaneously applied both as scatterer and as absorber. In the framework of this thesis the Si(Li) polarimeter could be applied in different experiments on the radiative electron capture and on the characteristic radiation at the experimental storage ring of the GSI. The characterization of the detector pursued by means of the highly polarized radiation of the electron capture into the K shell of naked xenon. In the following in two further experiments new values on the polarization of the electron capture into the K shell both of the naked and of the hydrogen-like uranium were performed.

  5. Local crystallography analysis for atomically resolved scanning tunneling microscopy images

    International Nuclear Information System (INIS)

    Lin, Wenzhi; Li, Qing; Belianinov, Alexei; Gai, Zheng; Baddorf, Arthur P; Pan, Minghu; Jesse, Stephen; Kalinin, Sergei V; Sales, Brian C; Sefat, Athena

    2013-01-01

    Scanning probe microscopy has emerged as a powerful and flexible tool for atomically resolved imaging of surface structures. However, due to the amount of information extracted, in many cases the interpretation of such data is limited to being qualitative and semi-quantitative in nature. At the same time, much can be learned from local atom parameters, such as distances and angles, that can be analyzed and interpreted as variations of local chemical bonding, or order parameter fields. Here, we demonstrate an iterative algorithm for indexing and determining atomic positions that allows the analysis of inhomogeneous surfaces. This approach is further illustrated by local crystallographic analysis of several real surfaces, including highly ordered pyrolytic graphite and an Fe-based superconductor FeTe 0.55 Se 0.45 . This study provides a new pathway to extract and quantify local properties for scanning probe microscopy images. (paper)

  6. Time-resolved tomographic images of a relativistic electron beam

    International Nuclear Information System (INIS)

    Koehler, H.A.; Jacoby, B.A.; Nelson, M.

    1984-07-01

    We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0 0 , 61 0 , and 117 0 . The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse

  7. Resolving a central ICF issue for ignition: Implosion symmertry

    International Nuclear Information System (INIS)

    Cray, M.; Delamater, N.D.; Fernandez, J.C.

    1994-01-01

    The Los Alamos National Laboratory Inertial Confinement Fusion (ICF) Program focuses on resolving key target-physics issues and developing technology needed for the National Ignition Facility (NIF). This work is being performed in collaboration with Lawrence Livermore National Laboratory (LLNL). A major requirement for the indirect-drive NIF ignition target is to achieve the irradiation uniformity on the capsule surface needed for a symmetrical high-convergence implosion. Los Alamos employed an integrated modeling technique using the Lasnex radiation-hydrodynamics code to design two different targets that achieve ignition and moderate gain. Los Alamos is performing experiments on the Nova Laser at LLNL in order to validate our NIF ignition calculations

  8. Resolving amorphous solid-liquid interfaces by atomic force microscopy

    International Nuclear Information System (INIS)

    Burson, Kristen M.; Gura, Leonard; Kell, Burkhard; Büchner, Christin; Lewandowski, Adrian L.; Heyde, Markus; Freund, Hans-Joachim

    2016-01-01

    Recent advancements in liquid atomic force microscopy make it an ideal technique for probing the structure of solid-liquid interfaces. Here, we present a structural study of a two-dimensional amorphous silica bilayer immersed in an aqueous solution utilizing liquid atomic force microscopy with sub-nanometer resolution. Structures show good agreement with atomically resolved ultra-high vacuum scanning tunneling microscopy images obtained on the same sample system, owing to the structural stability of the silica bilayer and the imaging clarity from the two-dimensional sample system. Pair distance histograms of ring center positions are utilized to develop quantitative metrics for structural comparison, and the physical origin of pair distance histogram peaks is addressed by direct assessment of real space structures.

  9. Fully Resolved Simulations of 3D Printing

    Science.gov (United States)

    Tryggvason, Gretar; Xia, Huanxiong; Lu, Jiacai

    2017-11-01

    Numerical simulations of Fused Deposition Modeling (FDM) (or Fused Filament Fabrication) where a filament of hot, viscous polymer is deposited to ``print'' a three-dimensional object, layer by layer, are presented. A finite volume/front tracking method is used to follow the injection, cooling, solidification and shrinking of the filament. The injection of the hot melt is modeled using a volume source, combined with a nozzle, modeled as an immersed boundary, that follows a prescribed trajectory. The viscosity of the melt depends on the temperature and the shear rate and the polymer becomes immobile as its viscosity increases. As the polymer solidifies, the stress is found by assuming a hyperelastic constitutive equation. The method is described and its accuracy and convergence properties are tested by grid refinement studies for a simple setup involving two short filaments, one on top of the other. The effect of the various injection parameters, such as nozzle velocity and injection velocity are briefly examined and the applicability of the approach to simulate the construction of simple multilayer objects is shown. The role of fully resolved simulations for additive manufacturing and their use for novel processes and as the ``ground truth'' for reduced order models is discussed.

  10. The Resolved Stellar Population of Leo A

    Science.gov (United States)

    Tolstoy, Eline

    1996-05-01

    New observations of the resolved stellar population of the extremely metal-poor Magellanic dwarf irregular galaxy Leo A in Thuan-Gunn r, g, i, and narrowband Hα filters are presented. Using the recent Cepheid variable star distance determination to Leo A by Hoessel et al., we are able to create an accurate color-magnitude diagram (CMD). We have used the Bavesian inference method described by Tolstoy & Saha to calculate the likelihood of a Monte Carlo simulation of the stellar population of Leo A being a good match to the data within the well understood errors in the data. The magnitude limits on our data are sensitive enough to look back at ~1 Gyr of star formation history at the distance of Leo A. To explain the observed ratio of red to blue stars in the observed CMD, it is necessary to invoke either a steadily decreasing star formation rate toward the present time or gaps in the star formation history. We also compare the properties of the observed stellar population with the known spatial distribution of the H I gas and H II regions to support the conclusions from CMD modeling. We consider the possibility that currently there is a period of diminished star formation in Leo A, as evidenced by the lack of very young stars in the CMD and the faint H II regions. How the chaotic H I distribution, with no observable rotation, fits into our picture of the evolution of Leo A is as yet unclear.

  11. Component-resolved diagnostics in vernal conjunctivitis.

    Science.gov (United States)

    Armentia, Alicia; Sanchís, Eugenia; Montero, Javier A

    2016-10-01

    Conventional diagnostic tests in allergy are insufficient to clarify the cause of vernal conjunctivitis. Component-resolved diagnostic (CRD) by microarray allergen assay may be useful in detecting allergens that might be involved in the inflammatory process. In a recent trial in patients suffered from eosinophilic esophagitis, after 2 years of the CRD-guided exclusion diet and specific immunotherapy, significant clinical improvement was observed, and 68% of patients were discharged (cure based on negative biopsy, no symptoms, and no medication intake). Our new objective was to evaluate IgE-mediated hypersensitivity by CRD in tears and serum from patients with vernal conjunctivitis and treat patients with identified triggering allergens by specific immunotherapy. Twenty-five patients with vernal conjunctivitis were evaluated. The identified triggering allergens were n Lol p 1 (11 cases), n Cyn d 1 (eight cases), group 4 and 6 grasses (six cases) and group 5 of grasses (five cases). Prick test and pollen IgE were positive in one case. Clinical improvement was observed in 13/25 vernal conjunctivitis patients after 1-year specific immunotherapy. CRD seems to be a more sensitive diagnostic tool compared with prick test and IgE detection. Specific CRD-led immunotherapy may achieve clinical improvements in vernal conjunctivitis patients.

  12. Component Resolved Diagnosis in Hymenoptera Anaphylaxis.

    Science.gov (United States)

    Tomsitz, D; Brockow, K

    2017-06-01

    Hymenoptera anaphylaxis is one of the leading causes of severe allergic reactions and can be fatal. Venom-specific immunotherapy (VIT) can prevent a life-threatening reaction; however, confirmation of an allergy to a Hymenoptera venom is a prerequisite before starting such a treatment. Component resolved diagnostics (CRD) have helped to better identify the responsible allergen. Many new insect venom allergens have been identified within the last few years. Commercially available recombinant allergens offer new diagnostic tools for detecting sensitivity to insect venoms. Additional added sensitivity to nearly 95% was introduced by spiking yellow jacket venom (YJV) extract with Ves v 5. The further value of CRD for sensitivity in YJV and honey bee venom (HBV) allergy is more controversially discussed. Recombinant allergens devoid of cross-reactive carbohydrate determinants often help to identify the culprit venom in patients with double sensitivity to YJV and HBV. CRD identified a group of patients with predominant Api m 10 sensitization, which may be less well protected by VIT, as some treatment extracts are lacking this allergen. The diagnostic gap of previously undetected Hymenoptera allergy has been decreased via production of recombinant allergens. Knowledge of analogies in interspecies proteins and cross-reactive carbohydrate determinants is necessary to distinguish relevant from irrelevant sensitizations.

  13. Resolved Parental Infertility and Children's Educational Achievement.

    Science.gov (United States)

    Branigan, Amelia R; Helgertz, Jonas

    2017-06-01

    Although difficulty conceiving a child has long been a major medical and social preoccupation, it has not been considered as a predictor of long-term outcomes in children ultimately conceived. This is consistent with a broader gap in knowledge regarding the consequences of parental health for educational performance in offspring. Here we address that omission, asking how resolved parental infertility relates to children's academic achievement. In a sample of all Swedish births between 1988 and 1995, we find that involuntary childlessness prior to either a first or a second birth is associated with lower academic achievement (both test scores and GPA) in children at age 16, even if the period of infertility was prior to a sibling's birth rather than the child's own. Our results support a conceptualization of infertility as a cumulative physical and social experience with effects extending well beyond the point at which a child is born, and emphasize the need to better understand how specific parental health conditions constrain children's educational outcomes.

  14. Photon number projection using non-number-resolving detectors

    International Nuclear Information System (INIS)

    Rohde, Peter P; Webb, James G; Huntington, Elanor H; Ralph, Timothy C

    2007-01-01

    Number-resolving photo-detection is necessary for many quantum optics experiments, especially in the application of entangled state preparation. Several schemes have been proposed for approximating number-resolving photo-detection using non-number-resolving detectors. Such techniques include multi-port detection and time-division multiplexing. We provide a detailed analysis and comparison of different number-resolving detection schemes, with a view to creating a useful reference for experimentalists. We show that the ideal architecture for projective measurements is a function of the detector's dark count and efficiency parameters. We also describe a process for selecting an appropriate topology given actual experimental component parameters

  15. Optimized respiratory-resolved motion-compensated 3D Cartesian coronary MR angiography.

    Science.gov (United States)

    Correia, Teresa; Ginami, Giulia; Cruz, Gastão; Neji, Radhouene; Rashid, Imran; Botnar, René M; Prieto, Claudia

    2018-04-22

    To develop a robust and efficient reconstruction framework that provides high-quality motion-compensated respiratory-resolved images from free-breathing 3D whole-heart Cartesian coronary magnetic resonance angiography (CMRA) acquisitions. Recently, XD-GRASP (eXtra-Dimensional Golden-angle RAdial Sparse Parallel MRI) was proposed to achieve 100% scan efficiency and provide respiratory-resolved 3D radial CMRA images by exploiting sparsity in the respiratory dimension. Here, a reconstruction framework for Cartesian CMRA imaging is proposed, which provides respiratory-resolved motion-compensated images by incorporating 2D beat-to-beat translational motion information to increase sparsity in the respiratory dimension. The motion information is extracted from interleaved image navigators and is also used to compensate for 2D translational motion within each respiratory phase. The proposed Optimized Respiratory-resolved Cartesian Coronary MR Angiography (XD-ORCCA) method was tested on 10 healthy subjects and 2 patients with cardiovascular disease, and compared against XD-GRASP. The proposed XD-ORCCA provides high-quality respiratory-resolved images, allowing clear visualization of the right and left coronary arteries, even for irregular breathing patterns. Compared with XD-GRASP, the proposed method improves the visibility and sharpness of both coronaries. Significant differences (p respiratory phases with larger motion amplitudes and subjects with irregular breathing patterns. A robust respiratory-resolved motion-compensated framework for Cartesian CMRA has been proposed and tested in healthy subjects and patients. The proposed XD-ORCCA provides high-quality images for all respiratory phases, independently of the regularity of the breathing pattern. © 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  16. Computed tomography with energy-resolved detection: a feasibility study

    Science.gov (United States)

    Shikhaliev, Polad M.

    2008-03-01

    The feasibility of computed tomography (CT) with energy-resolved x-ray detection has been investigated. A breast CT design with multi slit multi slice (MSMS) data acquisition was used for this study. The MSMS CT includes linear arrays of photon counting detectors separated by gaps. This CT configuration allows for efficient scatter rejection and 3D data acquisition. The energy-resolved CT images were simulated using a digital breast phantom and the design parameters of the proposed MSMS CT. The phantom had 14 cm diameter and 50/50 adipose/glandular composition, and included carcinoma, adipose, blood, iodine and CaCO3 as contrast elements. The x-ray technique was 90 kVp tube voltage with 660 mR skin exposure. Photon counting, charge (energy) integrating and photon energy weighting CT images were generated. The contrast-to-noise (CNR) improvement with photon energy weighting was quantified. The dual energy subtracted images of CaCO3 and iodine were generated using a single CT scan at a fixed x-ray tube voltage. The x-ray spectrum was electronically split into low- and high-energy parts by a photon counting detector. The CNR of the energy weighting CT images of carcinoma, blood, adipose, iodine, and CaCO3 was higher by a factor of 1.16, 1.20, 1.21, 1.36 and 1.35, respectively, as compared to CT with a conventional charge (energy) integrating detector. Photon energy weighting was applied to CT projections prior to dual energy subtraction and reconstruction. Photon energy weighting improved the CNR in dual energy subtracted CT images of CaCO3 and iodine by a factor of 1.35 and 1.33, respectively. The combination of CNR improvements due to scatter rejection and energy weighting was in the range of 1.71-2 depending on the type of the contrast element. The tilted angle CZT detector was considered as the detector of choice. Experiments were performed to test the effect of the tilting angle on the energy spectrum. Using the CZT detector with 20° tilting angle decreased the

  17. Energy and angle resolved ion scattering spectroscopy: new possibilities for surface analysis

    International Nuclear Information System (INIS)

    Hellings, G.J.A.

    1986-01-01

    In this thesis the design and development of a novel, very sensitive and high-resolving spectrometer for surface analysis is described. This spectrometer is designed for Energy and Angle Resolved Ion Scattering Spectroscopy (EARISS). There are only a few techniques that are sensitive enough to study the outermost atomic layer of surfaces. One of these techniques, Low-Energy Ion Scattering (LEIS), is discussed in chapter 2. Since LEIS is destructive, it is important to make a very efficient use of the scattered ions. This makes it attractive to simultaneously carry out energy and angle dependent measurements (EARISS). (Auth.)

  18. Rapid and economical data acquisition in ultrafast frequency-resolved spectroscopy using choppers and a microcontroller.

    Science.gov (United States)

    Guo, Liang; Monahan, Daniele M; Fleming, Graham

    2016-08-08

    Spectrometers and cameras are used in ultrafast spectroscopy to achieve high resolution in both time and frequency domains. Frequency-resolved signals from the camera pixels cannot be processed by common lock-in amplifiers, which have only a limited number of input channels. Here we demonstrate a rapid and economical method that achieves the function of a lock-in amplifier using mechanical choppers and a programmable microcontroller. We demonstrate the method's effectiveness by performing a frequency-resolved pump-probe measurement on the dye Nile Blue in solution.

  19. Using resolvent analysis for the design of separation control on a NACA 0012 airfoil

    Science.gov (United States)

    Yeh, Chi-An; Taira, Kunihiko

    2017-11-01

    A combined effort based on large-eddy simulation and resolvent analysis on the separated flow over a NACA 0012 airfoil is conducted to design active flow control for suppression of separation. This study considers the the airfoil at 6 deg. angle-of-attack and Reynolds number of 23000. The response mode obtained from the resolvent analysis about the baseline turbulent mean flow reveals modal structures that can be categorized into three families when sweeping through the resonant frequency: (1) von Karman wake structure for low frequency; (2) Kelvin-Helmholtz structure in the separation bubble for high frequency; (3) blended structure of (1) and (2) for the intermediate frequency. Leveraging the insights from resolvent analysis, unsteady thermal actuation is introduced to the flow near the leading-edge to examine the use of the frequencies from three families for separation control in LES. As indicated by the resolvent response modes, we find that the use of intermediate frequencies are most effective in suppressing the flow separation, since the shear layer over the separation bubble and the wake are both receptive to the perturbation at the these frequencies. The resolvent-analysis-based control strategy achieves 35% drag reduction and 9% lift increase with effective frequency. This work was supported by Office of Naval Research (N00014-15-R-FO13) and Army Research Office (W911NF-14-1-0224).

  20. Panchromatic SED modelling of spatially resolved galaxies

    Science.gov (United States)

    Smith, Daniel J. B.; Hayward, Christopher C.

    2018-05-01

    We test the efficacy of the energy-balance spectral energy distribution (SED) fitting code MAGPHYS for recovering the spatially resolved properties of a simulated isolated disc galaxy, for which it was not designed. We perform 226 950 MAGPHYS SED fits to regions between 0.2 and 25 kpc in size across the galaxy's disc, viewed from three different sight-lines, to probe how well MAGPHYS can recover key galaxy properties based on 21 bands of UV-far-infrared model photometry. MAGPHYS yields statistically acceptable fits to >99 per cent of the pixels within the r-band effective radius and between 59 and 77 percent of pixels within 20 kpc of the nucleus. MAGPHYS is able to recover the distribution of stellar mass, star formation rate (SFR), specific SFR, dust luminosity, dust mass, and V-band attenuation reasonably well, especially when the pixel size is ≳ 1 kpc, whereas non-standard outputs (stellar metallicity and mass-weighted age) are recovered less well. Accurate recovery is more challenging in the smallest sub-regions of the disc (pixel scale ≲ 1 kpc), where the energy balance criterion becomes increasingly incorrect. Estimating integrated galaxy properties by summing the recovered pixel values, the true integrated values of all parameters considered except metallicity and age are well recovered at all spatial resolutions, ranging from 0.2 kpc to integrating across the disc, albeit with some evidence for resolution-dependent biases. These results must be considered when attempting to analyse the structure of real galaxies with actual observational data, for which the `ground truth' is unknown.

  1. Resolved Hapke parameter maps of the Moon

    Science.gov (United States)

    Sato, H.; Robinson, M. S.; Hapke, B.; Denevi, B. W.; Boyd, A. K.

    2014-08-01

    We derived spatially resolved near-global Hapke photometric parameter maps of the Moon from 21 months of Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) multispectral observations using a novel "tile-by-tile method" (1° latitude by 1° longitude bins). The derived six parameters (w,b,c,BS0,hS, andθ¯p) for each tile were used to normalize the observed reflectance (standard angles i = g = 60°, e = 0° instead of the traditional angles i = g = 30°, e = 0°) within each tile, resulting in accurate normalization optimized for the local photometric response. Each pixel in the seven-color near-global mosaic (70°S to 70°N and 0°E to 360°E) was computed by the median of normalized reflectance from large numbers of repeated observations (UV: ˜50 and visible: ˜126 on average). The derived mosaic exhibits no significant artifacts with latitude or along the tile boundaries, demonstrating the quality of the normalization procedure. The derived Hapke parameter maps reveal regional photometric response variations across the lunar surface. The b, c (Henyey-Greenstein double-lobed phase function parameters) maps demonstrate decreased backscattering in the maria relative to the highlands (except 321 nm band), probably due to the higher content of both SMFe (submicron iron) and ilmenite in the interiors of back scattering agglutinates in the maria. The hS (angular width of shadow hiding opposition effect) map exhibits relatively lower values in the maria than the highlands and slightly higher values for immature highland crater ejecta, possibly related to the variation in a grain size distribution of regolith.

  2. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, A. L.; Steenbergen, W.; van Leeuwen, T. G.; de Mul, F. F. M.

    2002-01-01

    A low coherence Mach-Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scattered photons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  3. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, Anna; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.

    2002-01-01

    A low coherence Mach–Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scatteredphotons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  4. Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures

    NARCIS (Netherlands)

    Rizo, P. J.; Pugzlys, A.; Liu, J.; Reuter, D.; Wieck, A. D.; van der Wal, C. H.; van Loosdrecht, P. H. M.; Pugžlys, A.

    2008-01-01

    A compact cryogenic Kerr microscope for operation in the small volume of high-field magnets is described. It is suited for measurements both in Voigt and Faraday configurations. Coupled with a pulsed laser source, the microscope is used to measure the time-resolved Kerr rotation response of

  5. Angle-resolved photoemission study of NiO and CoO

    International Nuclear Information System (INIS)

    Shen, Z.X.; Lindberg, P.A.P.; Shih, C.K.; Spicer, W.E.; Lindau, I.

    1989-01-01

    The authors report an angle-resolved photoemission investigation of the electronic structures of NiO and CoO. The lattice effects on the photoemission spectra of these highly correlated materials are important. The magnitudes of dispersions of the oxygen bands agree with band calculations, but the experimental data of the localized 3d bands do not agree with the band calculations

  6. Timepix3 as X-ray detector for time resolved synchrotron experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yousef, Hazem, E-mail: hazem.yousef@diamond.ac.uk; Crevatin, Giulio; Gimenez, Eva N.; Horswell, Ian; Omar, David; Tartoni, Nicola

    2017-02-11

    The Timepix3 ASIC can be used very effectively for time resolved experiments at synchrotron facilities. We have carried out characterizations with the synchrotron beam in order to determine the time resolution and other characteristics such as the energy resolution, charge sharing and signals overlapping. The best time resolution achieved is 19 ns FWHM for 12 keV photons and 350 V bias voltage. The time resolution shows dependency on the photon energy as well as on the chip and acquisition parameters. - Highlights: • An estimate time resolution of the Timepix3 is produced based on the arrival time. • At high resolution, the time structure of the DLS synchrotron beam is resolved. • The arrival time information improves combining the charge split events. • The results enable performing a wide range of time resolved experiments.

  7. Time-resolved PHERMEX image restorations constrained with an additional multiply-exposed image

    International Nuclear Information System (INIS)

    Kruger, R.P.; Breedlove, J.R. Jr.; Trussell, H.J.

    1978-06-01

    There are a number of possible industrial and scientific applications of nanosecond cineradiographs. Although the technology exists to produce closely spaced pulses of x rays for this application, the quality of the time-resolved radiographs is severely limited. The limitations arise from the necessity of using a fluorescent screen to convert the transmitted x rays to light and then using electro-optical imaging systems to gate and to record the images with conventional high-speed cameras. It has been proposed that, in addition to the time-resolved images, a conventional multiply exposed radiograph be obtained. This report uses both PHERMEX and conventional photographic simulations to demonstrate that the additional information supplied by the multiply exposed radiograph can be used to improve the quality of digital image restorations of the time-resolved pictures over what could be achieved with the degraded images alone

  8. Characterizing the Resolved M6 Dwarf Twin LP 318-218AB

    Science.gov (United States)

    Moreno Hilario, Elizabeth; Burgasser, Adam J.; Bardalez Gagliuffi, Daniella; Tamiya, Tomoki

    2017-01-01

    The lowest-mass stars and brown dwarfs are among the most common objects in the Milky Way Galaxy, but theories of their formation and evolution remain poorly constrained. Binary systems are important for understanding the formation of these objects and for making direct orbit and mass measurements to validate evolutionary theories. We report the discovery of LP 318-218, a high proper motion late M dwarf, as a near equal-brightness binary system with a separation of 0.72 arcseconds. Resolved near-infrared spectroscopy confirms the components as nearly identical M6 twins. We using our resolved photometry and spectroscopy to estimate the distance, projected separation and tangential velocity of the system, and confirm common proper motion. We also perform atmosphere model fits to the resolved spectra to assess their physical properties. We place LP 318-218 in context with other widely-separated late M dwarf binaries.

  9. Time-resolved imaging of purely valence-electron dynamics during a chemical reaction

    DEFF Research Database (Denmark)

    Hockett, Paul; Bisgaard, Christer Z.; Clarkin, Owen J.

    2011-01-01

    Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems(1-6). By contrast, time-resolved structural-dynamics methods...... such as electron(7-10) or X-ray diffraction(11) and X-ray absorption(12) yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy(13-15) and high-harmonic generation(16......,17): in both cases, this sensitivity derives from the ionization-matrix element(18,19). Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during...

  10. Timepix3 as X-ray detector for time resolved synchrotron experiments

    International Nuclear Information System (INIS)

    Yousef, Hazem; Crevatin, Giulio; Gimenez, Eva N.; Horswell, Ian; Omar, David; Tartoni, Nicola

    2017-01-01

    The Timepix3 ASIC can be used very effectively for time resolved experiments at synchrotron facilities. We have carried out characterizations with the synchrotron beam in order to determine the time resolution and other characteristics such as the energy resolution, charge sharing and signals overlapping. The best time resolution achieved is 19 ns FWHM for 12 keV photons and 350 V bias voltage. The time resolution shows dependency on the photon energy as well as on the chip and acquisition parameters. - Highlights: • An estimate time resolution of the Timepix3 is produced based on the arrival time. • At high resolution, the time structure of the DLS synchrotron beam is resolved. • The arrival time information improves combining the charge split events. • The results enable performing a wide range of time resolved experiments.

  11. EVIDENCE FOR DUST CLEARING THROUGH RESOLVED SUBMILLIMETER IMAGING

    International Nuclear Information System (INIS)

    Brown, J. M.; Blake, G. A.; Qi, C.; Wilner, D. J.; Dullemond, C. P.; Williams, J. P.

    2009-01-01

    Mid-infrared spectrophotometric observations have revealed a small subclass of circumstellar disks with spectral energy distributions (SEDs) suggestive of large inner gaps with low dust content. However, such data provide only an indirect and model-dependent method of finding central holes. Imaging of protoplanetry disks provides an independent check of SED modeling. We present here the direct characterization of three 33-47 AU radii inner gaps, in the disks around LkHα 330, SR 21N, and HD 135344B, via 340 GHz (880 μm) dust continuum aperture synthesis observations obtained with the Submillimeter Array (SMA). The large gaps are fully resolved at ∼0.''3 by the SMA data and mostly empty of dust, with less than (1-7.5) x 10 -6 M sun of fine grained solids inside the holes. Gas (as traced by atomic accretion markers and CO 4.7 μm rovibrational emission) is still present in the inner regions of all three disks. For each, the inner hole exhibits a relatively steep rise in dust emission to the outer disk, a feature more likely to originate from the gravitational influence of a companion body than from a process expected to show a more shallow gradient like grain growth. Importantly, the good agreement between the spatially resolved data and spectrophotometry-based models lends confidence to current interpretations of SEDs, wherein the significant dust emission deficits arise from disks with inner gaps or holes. Further SED-based searches can therefore be expected to yield numerous additional candidates that can be examined at high spatial resolution.

  12. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    Directory of Open Access Journals (Sweden)

    Heubl Günther

    2010-11-01

    Full Text Available Abstract Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results Our analysis of the rapidly evolving trnK/matK, trnL-F and rps16 chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position. Conclusions Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a

  13. Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

    Science.gov (United States)

    2010-01-01

    Background In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past. Results Our analysis of the rapidly evolving trnK/matK, trnL-F and rps16 chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae) and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position. Conclusions Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a fully resolved plastid tree of

  14. Size-resolved particle emission factors for individual ships

    Science.gov (United States)

    Jonsson, Åsa M.; Westerlund, Jonathan; Hallquist, Mattias

    2011-07-01

    In these experiments size-resolved emission factors for particle number (EFPN) and mass (EFPM) have been determined for 734 individual ship passages for real-world dilution. The method used is an extractive sampling method of the passing ship plumes where particle number/mass and CO2 were measured with high time resolution (1 Hz). The measurements were conducted on a small island located in the entrance to the port of Gothenburg (N57.6849, E11.838), the largest harbor in Scandinavia. This is an emission control area (ECA) and in close vicinity to populated areas. The average EFPN and EFPM were 2.55 ± 0.11 × 1016 (kg fuel)-1 and 2050 ± 110 mg (kg fuel)-1, respectively. The determined EF for ships with multiple passages showed a great reproducibility. Size-resolved EFPN were peaking at small particle sizes ˜35 nm. Smaller particle sizes and hence less mass were observed by a gas turbine equipped ship compared to diesel engine equipped ships. On average 36 to 46% of the emitted particles by number were non-volatile and 24% by mass (EFPN 1.16 ± 0.19 × 1016 [kg fuel]-1 and EFPM 488 ± 73 mg [kg fuel]-1, respectively). This study shows a great potential to gain large data-sets regarding ship emission determining parameters that can improve current dispersion modeling for health assessments on local and regional scales. The global contributions of total and non-volatile particle mass from shipping using this extensive data-set from an ECA were estimated to be at least 0.80 Tgy-1 and 0.19 Tgy-1.

  15. Time-resolved Femtosecond Photon Echo Probes Bimodal Solvent Dynamics

    NARCIS (Netherlands)

    Pshenichnikov, M.S; Duppen, K.; Wiersma, D. A.

    1995-01-01

    We report on time-resolved femtosecond photon echo experiments of a dye molecule in a polar solution. The photon echo is time resolved by mixing the echo with a femtosecond gate pulse in a nonlinear crystal. It is shown that the temporal profile of the photon echo allows separation of the

  16. 48 CFR 29.101 - Resolving tax problems.

    Science.gov (United States)

    2010-10-01

    .... (d) Before purchasing goods or services from a foreign source, the contracting officer should consult... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Resolving tax problems. 29... CONTRACTING REQUIREMENTS TAXES General 29.101 Resolving tax problems. (a) Contract tax problems are...

  17. 48 CFR 30.606 - Resolving cost impacts.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Resolving cost impacts. 30... impacts. (a) General. (1) The CFAO shall coordinate with the affected contracting officers before negotiating and resolving the cost impact when the estimated cost impact on any of their contracts is at least...

  18. Relevance of the law of international organisations in resolving ...

    African Journals Online (AJOL)

    structures to resolve disputes between states. Uncertainty remains, however, on the availability of effective structures within the system to resolve disputes between international organisations. It is important to note that international organisations were, prior to 1945, not considered subjects of international law so as to be ...

  19. Theoretical resolving power of a radiofrequency mass spectrometer

    International Nuclear Information System (INIS)

    Coc, A.; Le Gac, R.; Saint Simon, M. de; Thibault, C.; Touchard, F.

    1988-01-01

    Radiofrequency mass spectrometers of L.G. Smith's type can reach a resolving power of 10 6 -10 7 and a precision of 10 -9 -10 -10 . The resolving power, shape of peaks and limitations are described. As an example, the spectrometer to be used in an experiment aimed at measuring the anti p/p mass ratio is considered. (orig.)

  20. Study on sociological approach to resolve maintenance related social problems

    International Nuclear Information System (INIS)

    Aoki, Takayuki

    2007-01-01

    This study proposes a sociological approach to resolve maintenance related social problems. As a result of consideration, the followings were found. (1) In general, solutions to some kinds of questions can be deduced from basic laws using some theories or methodologies in the field of the natural science or engineering. The approach to resolve maintenance related social problems is similar to the approach in the natural science or engineering. (2) The points of view based on fundamental human rights, market principles and community principles, and so on, are very important in resolving maintenance related social problems and can be placed as theories or tools for resolution. (3) If such theories or tools for resolving maintenance related social problems as described above are systematically prepared, it is estimated that it becomes very much easier to resolve maintenance related social problems. (author)

  1. Spatially-resolved measurement of optically stimulated luminescence and time-resolved luminescence

    International Nuclear Information System (INIS)

    Bailiff, I.K.; Mikhailik, V.B.

    2003-01-01

    Spatially-resolved measurements of optically stimulated luminescence (OSL) were performed using a two-dimensional scanning system designed for use with planar samples. The scanning system employs a focused laser beam to stimulate a selected area of the sample, which is moved under the beam by a motorised stage. Exposure of the sample is controlled by an electronic shutter. Mapping of the distribution of OSL using a continuous wave laser source was obtained with sub-millimeter resolution for samples of sliced brick, synthetic single crystal quartz, concrete and dental ceramic. These revealed sporadic emission in the case of brick or concrete and significant spatial variation of emission for quartz and dental ceramic slices. Determinations of absorbed dose were performed for quartz grains within a slice of modern brick. Reconfiguration of the scanner with a pulsed laser source enabled quartz and feldspathic minerals within a ceramic sample to be thinner region. about 6 nm from the extrapolation of themeasuring the time-resolved luminescence spectrum

  2. Approach to resolving mechanism of epilepsy in autism spectrum disorders

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Toshiaki; Tsuda, Yoshimi [Naruto Univ. of Education, Naruto, Tokushima (Japan); Mori, Kenji; Fujii, Emiko; Fukumoto, Rei; Miyazaki, Masahito; Harada, Masashi [Tokushima Univ., Faculty of Medicine, Tokushima, Tokushima (Japan)

    2007-12-15

    Electroencephalography (EEG) abnormality is highly frequent in the autism spectrum disorders (ASD), where epilepsy is also highly complicated relative to general population. Authors have found that the abnormal EEG is evoked mainly from the forehead area. For the purpose to resolve the mechanism of epilepsy, the present study was performed on single photon emission computed tomography (SPECT) and {sup 1}H- MR spectroscopy (MRS) images in ASD patients. In the former, 167 MBq of {sup 123}I-iomazenil was intravenously injected to 24 patients (5-21 years old, M/F 21/3) and SPECT was done 3 hrs later, of which findings suggested the lowered activity of gamma aminobutyric acid (GABA) receptors in the frontal lobe. The latter {sup 1}H-MRS was performed in 44 patients (2-17 years old, M/F 36/8) and 10 controls of the same generation with GE Signa Vhi 3T with the region of interest (ROI) of the left frontal lobe. MEGA-PRESS and stimulated-echo acquisition mode (STEAM) methods were applied for GABA and N-acetylaspartate (NAA) measurements, respectively, with LC Model for their levels. The GABA level was found lower in the lobe than control. Results above suggested the presence of a certain functional abnormality in GABA system in ASD. (R.T.)

  3. Time resolved EUV spectra from Zpinching capillary discharge plasma

    Science.gov (United States)

    Jancarek, Alexandr; Nevrkla, Michal; Nawaz, Fahad

    2015-09-01

    We developed symmetrically charged driver to obtain high voltage, high current Z-pinching capillary discharge. Plasma is created by up to 70 kA, 29 ns risetime current pulse passing through a 5 mm inner diameter, 224 mm long capillary filled with gas to initial pressure in the range of 1 kPa. Due to the low inductance design of the driver, the pinch is observable directly from the measured current curve. Time-integrated and time-resolved spectra of discharge plasma radiation are recorded together with the capillary current and analyzed. The most encouraging spectra were captured in the wavelength range 8.3 ÷ 14 nm. This spectral region contains nitrogen Balmer series lines including potentially lasing NVII 2 - 3 transition. Spectral lines are identified in the NIST database using the FLY kinetic code. The line of 13.38 nm wavelength, transition NVII 2 - 3, was observed in gated, and also in time-integrated spectra for currents >60 kA. This work has been supported by the Ministry of Education, Youth and Sports of the Czech Republic grants LG13029.

  4. Approach to resolving mechanism of epilepsy in autism spectrum disorders

    International Nuclear Information System (INIS)

    Hashimoto, Toshiaki; Tsuda, Yoshimi; Mori, Kenji; Fujii, Emiko; Fukumoto, Rei; Miyazaki, Masahito; Harada, Masashi

    2007-01-01

    Electroencephalography (EEG) abnormality is highly frequent in the autism spectrum disorders (ASD), where epilepsy is also highly complicated relative to general population. Authors have found that the abnormal EEG is evoked mainly from the forehead area. For the purpose to resolve the mechanism of epilepsy, the present study was performed on single photon emission computed tomography (SPECT) and 1 H- MR spectroscopy (MRS) images in ASD patients. In the former, 167 MBq of 123 I-iomazenil was intravenously injected to 24 patients (5-21 years old, M/F 21/3) and SPECT was done 3 hrs later, of which findings suggested the lowered activity of gamma aminobutyric acid (GABA) receptors in the frontal lobe. The latter 1 H-MRS was performed in 44 patients (2-17 years old, M/F 36/8) and 10 controls of the same generation with GE Signa Vhi 3T with the region of interest (ROI) of the left frontal lobe. MEGA-PRESS and stimulated-echo acquisition mode (STEAM) methods were applied for GABA and N-acetylaspartate (NAA) measurements, respectively, with LC Model for their levels. The GABA level was found lower in the lobe than control. Results above suggested the presence of a certain functional abnormality in GABA system in ASD. (R.T.)

  5. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    International Nuclear Information System (INIS)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G.; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E.

    2016-01-01

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  6. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G. [Imperial College London, London (United Kingdom); Drakopoulos, Michael [Diamond Light Source, I12 Joint Engineering, Environmental, Processing (JEEP) Beamline, Didcot, Oxfordshire (United Kingdom); Rack, Alexander [European Synchrotron Radiation Facility, Grenoble (France); Eakins, Daniel E., E-mail: d.eakins@imperial.ac.uk [Imperial College London, London (United Kingdom)

    2016-03-24

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  7. Diffusion and dispersion characteristics of hybridized discontinuous Galerkin methods for under-resolved turbulence simulations

    Science.gov (United States)

    Moura, Rodrigo; Fernandez, Pablo; Mengaldo, Gianmarco

    2017-11-01

    We investigate the dispersion and diffusion characteristics of hybridized discontinuous Galerkin (DG) methods. This provides us with insights to develop robust and accurate high-order DG discretizations for under-resolved flow simulations. Using the eigenanalysis technique introduced in (Moura et al., JCP, 2015 and Mengaldo et al., Computers & Fluids, 2017), we present a dispersion-diffusion analysis for the linear advection-diffusion equation. The effect of the accuracy order, the Riemann flux and the viscous stabilization are investigated. Next, we examine the diffusion characteristics of hybridized DG methods for under-resolved turbulent flows. The implicit large-eddy simulation (iLES) of the inviscid and viscous Taylor-Green vortex (TGV) problems are considered to this end. The inviscid case is relevant in the limit of high Reynolds numbers Re , i.e. negligible molecular viscosity, while the viscous case explores the effect of Re on the accuracy and robustness of the simulations. The TGV cases considered here are particularly crucial to under-resolved turbulent free flows away from walls. We conclude the talk with a discussion on the connections between hybridized and standard DG methods for under-resolved flow simulations.

  8. An analytic approach to resolving problems in medical ethics.

    Science.gov (United States)

    Candee, D; Puka, B

    1984-06-01

    Education in ethics among practising professionals should provide a systematic procedure for resolving moral problems. A method for such decision-making is outlined using the two classical orientations in moral philosophy, teleology and deontology. Teleological views such as utilitarianism resolve moral dilemmas by calculating the excess of good over harm expected to be produced by each feasible alternative for action. The deontological view focuses on rights, duties, and principles of justice. Both methods are used to resolve the 1971 Johns Hopkins case of a baby born with Down's syndrome and duodenal atresia.

  9. An analytic approach to resolving problems in medical ethics.

    Science.gov (United States)

    Candee, D; Puka, B

    1984-01-01

    Education in ethics among practising professionals should provide a systematic procedure for resolving moral problems. A method for such decision-making is outlined using the two classical orientations in moral philosophy, teleology and deontology. Teleological views such as utilitarianism resolve moral dilemmas by calculating the excess of good over harm expected to be produced by each feasible alternative for action. The deontological view focuses on rights, duties, and principles of justice. Both methods are used to resolve the 1971 Johns Hopkins case of a baby born with Down's syndrome and duodenal atresia. PMID:6234395

  10. A simultaneous multi-slice selective J-resolved experiment for fully resolved scalar coupling information

    Science.gov (United States)

    Zeng, Qing; Lin, Liangjie; Chen, Jinyong; Lin, Yanqin; Barker, Peter B.; Chen, Zhong

    2017-09-01

    Proton-proton scalar coupling plays an important role in molecular structure elucidation. Many methods have been proposed for revealing scalar coupling networks involving chosen protons. However, determining all JHH values within a fully coupled network remains as a tedious process. Here, we propose a method termed as simultaneous multi-slice selective J-resolved spectroscopy (SMS-SEJRES) for simultaneously measuring JHH values out of all coupling networks in a sample within one experiment. In this work, gradient-encoded selective refocusing, PSYCHE decoupling and echo planar spectroscopic imaging (EPSI) detection module are adopted, resulting in different selective J-edited spectra extracted from different spatial positions. The proposed pulse sequence can facilitate the analysis of molecular structures. Therefore, it will interest scientists who would like to efficiently address the structural analysis of molecules.

  11. Time-resolved spectroscopy of the probe fluorescence in the study of human blood protein dynamic structure on SR beam

    International Nuclear Information System (INIS)

    Dobretsov, G.E.; Kurek, N.K.; Syrejshchikova, T.I.; Yakimenko, M.N.; Clarke, D.T.; Jones, G.R.; Munro, I.H.

    2000-01-01

    Time-resolved spectroscopy on the SRS of the Daresbury Laboratory was used for the study of the human serum lipoproteins and human blood albumins with fluorescent probes K-37 and K-35, developed in Russia. The probe K-37 was found sensitive to the difference in dynamic properties of the lipid objects. Two sets of the parameters were used for the description of lipid dynamic structure: (1) time-resolved fluorescence spectra and (2) time-resolved fluorescence depolarization as a function of rotational mobility of lipid molecules. Each measured dynamic parameter reflected the monotonous changes of dynamic properties in the range: lipid spheres-very low density lipoproteins-low density lipoproteins-high density lipoproteins-phospholipid liposomes. The range is characterized by the increase of the ratio polar/ nonpolar lipids. Thus, time-resolved fluorescence could be used to detect some structural modifications in lipoproteins related to atherosclerosis and subsequent cardiovascular diseases development

  12. Dual time-resolved temperature-jump fluorescence and infrared spectroscopy for the study of fast protein dynamics.

    Science.gov (United States)

    Davis, Caitlin M; Reddish, Michael J; Dyer, R Brian

    2017-05-05

    Time-resolved temperature-jump (T-jump) coupled with fluorescence and infrared (IR) spectroscopy is a powerful technique for monitoring protein dynamics. Although IR spectroscopy of the polypeptide amide I mode is more technically challenging, it offers complementary information because it directly probes changes in the protein backbone, whereas, fluorescence spectroscopy is sensitive to the environment of specific side chains. With the advent of widely tunable quantum cascade lasers (QCL) it is possible to efficiently probe multiple IR frequencies with high sensitivity and reproducibility. Here we describe a dual time-resolved T-jump fluorescence and IR spectrometer and its application to study protein folding dynamics. A Q-switched Ho:YAG laser provides the T-jump source for both time-resolved IR and fluorescence spectroscopy, which are probed by a QCL and Ti:Sapphire laser, respectively. The Ho:YAG laser simultaneously pumps the time-resolved IR and fluorescence spectrometers. The instrument has high sensitivity, with an IR absorbance detection limit of jump induced difference spectrum from 50ns to 0.5ms. This study demonstrates the power of the dual time-resolved T-jump fluorescence and IR spectroscopy to resolve complex folding mechanisms by complementary IR absorbance and fluorescence measurements of protein dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Time-resolved X-ray studies using third generation synchrotron radiation sources

    International Nuclear Information System (INIS)

    Mills, D.M.

    1991-10-01

    The third generation, high-brilliance, hard x-ray, synchrotron radiation (SR) sources currently under construction (ESRF at Grenoble, France; APS at Argonne, Illinois; and SPring-8 at Harima, Japan) will usher in a new era of x-ray experimentation for both physical and biological sciences. One of the most exciting areas of experimentation will be the extension of x-ray scattering and diffraction techniques to the study of transient or time-evolving systems. The high repetition rate, short-pulse duration, high brilliance, and variable spectral bandwidth of these sources make them ideal for x-ray time-resolved studies. The temporal properties (bunch length, interpulse period, etc.) of these new sources will be summarized. Finally, the scientific potential and the technological challenges of time-resolved x-ray scattering from these new sources will be described. 13 refs., 4 figs

  14. Time-resolved wave profile measurements in copper to Megabar pressures

    Energy Technology Data Exchange (ETDEWEB)

    Chhabildas, L C; Asay, J R

    1981-01-01

    Many time-resolved techniques have been developed which have greatly aided in the understanding of dynamic material behavior such as the high pressure-dynamic strength of materials. In the paper, time-resolved measurements of copper (at shock-induced high pressures and temperatures) are used to illustrate the capability of using such techniques to investigate high pressure strength. Continuous shock loading and release wave profiles have been made in copper to 93 GPa using velocity interferometric techniques. Fine structure in the release wave profiles from the shocked state indicates an increase in shear strength of copper to 1.5 GPa at 93 GPa from its ambient value of 0.08 GPa.

  15. Orbital Evolution and Orbital Phase Resolved Spectroscopy of the ...

    Indian Academy of Sciences (India)

    binary. We have carried out orbital phase resolved spectroscopy to mea- ... agreement with a simple model of a spherically symmetric stellar wind from the .... has a set of Narrow Field Instruments (NFI) comprising one Low Energy Concen-.

  16. Using a referee to resolve shipper-receiver differences

    International Nuclear Information System (INIS)

    Tietjen, G.L.

    1981-01-01

    Within the nuclear community, shipper-receiver differences generate considerable concern. Current methods of resolving these differences are discussed, prticularly the use of an umpire or referee. Numerous statistical problems connected with the present procedures are also considered

  17. Existence Results for a Family of Equations of Fractional Resolvent

    International Nuclear Information System (INIS)

    Ibrahim, R.W.; Qasem, S.A.; Zailan Siri

    2015-01-01

    This study deals with the presence and distinction of bounded m-solutions (type mild) for a family of generalized integral and differential equations of spot order with fractional resolvent and indefinite delay. (author)

  18. Motivations to Resolve Communication Dilemmas in Database-Mediated Collaboration

    National Research Council Canada - National Science Library

    Kalman, Michael E; Monge, Peter; Fulk, Janet; Heino, Rebecca

    2002-01-01

    ... it. This article develops and tests an expectancy model that predicts specific conditions under which collective benefits can be made to converge with private ones, thus resolving communication dilemmas...

  19. How Do We Resolve Holiday Problems?

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Chinese Ministry of Railways statistics show that from September 28 to October 7,the National Day Holiday period,China’s railway networks were used for 67 million trips,an all-time high.On October 1 alone,8.9 million trips

  20. On the resolvents methods in quantum perturbation calculations

    International Nuclear Information System (INIS)

    Burzynski, A.

    1979-01-01

    This paper gives a systematic review of resolvent methods in quantum perturbation calculations. The case of discrete spectrum of hamiltonian is considered specially (in the literature this is the fewest considered case). The topics of calculations of quantum transitions by using of the resolvent formalism, quantum transitions between states from particular subspaces, the shifts of energy levels, are shown. The main ideas of stationary perturbation theory developed by Lippmann and Schwinger are considered too. (author)

  1. An analytic approach to resolving problems in medical ethics.

    OpenAIRE

    Candee, D; Puka, B

    1984-01-01

    Education in ethics among practising professionals should provide a systematic procedure for resolving moral problems. A method for such decision-making is outlined using the two classical orientations in moral philosophy, teleology and deontology. Teleological views such as utilitarianism resolve moral dilemmas by calculating the excess of good over harm expected to be produced by each feasible alternative for action. The deontological view focuses on rights, duties, and principles of justic...

  2. Extended resolvent and inverse scattering with an application to KPI

    Science.gov (United States)

    Boiti, M.; Pempinelli, F.; Pogrebkov, A. K.; Prinari, B.

    2003-08-01

    We present in detail an extended resolvent approach for investigating linear problems associated to 2+1 dimensional integrable equations. Our presentation is based as an example on the nonstationary Schrödinger equation with potential being a perturbation of the one-soliton potential by means of a decaying two-dimensional function. Modification of the inverse scattering theory as well as properties of the Jost solutions and spectral data as follows from the resolvent approach are given.

  3. Extended resolvent and inverse scattering with an application to KPI

    International Nuclear Information System (INIS)

    Boiti, M.; Pempinelli, F.; Pogrebkov, A.K.; Prinari, B.

    2003-01-01

    We present in detail an extended resolvent approach for investigating linear problems associated to 2+1 dimensional integrable equations. Our presentation is based as an example on the nonstationary Schroedinger equation with potential being a perturbation of the one-soliton potential by means of a decaying two-dimensional function. Modification of the inverse scattering theory as well as properties of the Jost solutions and spectral data as follows from the resolvent approach are given

  4. Resolving the role of actoymyosin contractility in cell microrheology.

    Directory of Open Access Journals (Sweden)

    Christopher M Hale

    2009-09-01

    Full Text Available Einstein's original description of Brownian motion established a direct relationship between thermally-excited random forces and the transport properties of a submicron particle in a viscous liquid. Recent work based on reconstituted actin filament networks suggests that nonthermal forces driven by the motor protein myosin II can induce large non-equilibrium fluctuations that dominate the motion of particles in cytoskeletal networks. Here, using high-resolution particle tracking, we find that thermal forces, not myosin-induced fluctuating forces, drive the motion of submicron particles embedded in the cytoskeleton of living cells. These results resolve the roles of myosin II and contractile actomyosin structures in the motion of nanoparticles lodged in the cytoplasm, reveal the biphasic mechanical architecture of adherent cells-stiff contractile stress fibers interdigitating in a network at the cell cortex and a soft actin meshwork in the body of the cell, validate the method of particle tracking-microrheology, and reconcile seemingly disparate atomic force microscopy (AFM and particle-tracking microrheology measurements of living cells.

  5. Toward GEOS-6, A Global Cloud System Resolving Atmospheric Model

    Science.gov (United States)

    Putman, William M.

    2010-01-01

    NASA is committed to observing and understanding the weather and climate of our home planet through the use of multi-scale modeling systems and space-based observations. Global climate models have evolved to take advantage of the influx of multi- and many-core computing technologies and the availability of large clusters of multi-core microprocessors. GEOS-6 is a next-generation cloud system resolving atmospheric model that will place NASA at the forefront of scientific exploration of our atmosphere and climate. Model simulations with GEOS-6 will produce a realistic representation of our atmosphere on the scale of typical satellite observations, bringing a visual comprehension of model results to a new level among the climate enthusiasts. In preparation for GEOS-6, the agency's flagship Earth System Modeling Framework [JDl] has been enhanced to support cutting-edge high-resolution global climate and weather simulations. Improvements include a cubed-sphere grid that exposes parallelism; a non-hydrostatic finite volume dynamical core, and algorithm designed for co-processor technologies, among others. GEOS-6 represents a fundamental advancement in the capability of global Earth system models. The ability to directly compare global simulations at the resolution of spaceborne satellite images will lead to algorithm improvements and better utilization of space-based observations within the GOES data assimilation system

  6. Near-Infrared Spatially Resolved Spectroscopy for Tablet Quality Determination.

    Science.gov (United States)

    Igne, Benoît; Talwar, Sameer; Feng, Hanzhou; Drennen, James K; Anderson, Carl A

    2015-12-01

    Near-infrared (NIR) spectroscopy has become a well-established tool for the characterization of solid oral dosage forms manufacturing processes and finished products. In this work, the utility of a traditional single-point NIR measurement was compared with that of a spatially resolved spectroscopic (SRS) measurement for the determination of tablet assay. Experimental designs were used to create samples that allowed for calibration models to be developed and tested on both instruments. Samples possessing a poor distribution of ingredients (highly heterogeneous) were prepared by under-blending constituents prior to compaction to compare the analytical capabilities of the two NIR methods. The results indicate that SRS can provide spatial information that is usually obtainable only through imaging experiments for the determination of local heterogeneity and detection of abnormal tablets that would not be detected with single-point spectroscopy, thus complementing traditional NIR measurement systems for in-line, and in real-time tablet analysis. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Spatially resolved NEXAFS spectroscopy of siderophores in biological matrices

    International Nuclear Information System (INIS)

    Thieme, J; Kilcoyne, D; Tyliszczak, T; Haselwandter, K

    2013-01-01

    Iron is an essential nutrient for almost all forms of life. In the presence of oxygen iron is present in its ferric form which precipitates under formation of rather insoluble oxide-hydroxide polymers. Hence the bioavailability of iron is extremely low ( −17 M at pH 7 for Fe 3+ ). Under such conditions almost all microorganisms synthesize siderophores as iron chelating agents, thus solubilizing ferric iron from rather insoluble iron sources. Siderophores form soluble complexes with Fe 3+ . The present study aims at developing a methodology that would allow for the specific detection and localization of such iron chelators in their natural environment. The applicability of spatially resolved NEXAFS spectroscopy in the soft X-ray energy (E < 1 keV) range was evaluated for localization of typical fungal hydroxamate siderophores like ferrichrome or coprogen, which can be present in various biological materials. Results obtained with the scanning transmission X-ray microscopes at beamlines 11.0.2 and 5.3.2 of the ALS have shown characteristic signatures for siderophores. Thus NEXAFS spectroscopy at the carbon K-edge, nitrogen K-edge and iron L-edge with high spatial resolution has proven to be extremely useful for their identification in their natural environment. Spectra of different siderophores as well as spectra and images of biological material containing siderophores are presented

  8. Management potential of organizational culture in resolving business conflicts

    Directory of Open Access Journals (Sweden)

    Iryna Kopytova

    2018-03-01

    Full Text Available The purpose of the article is to determine peculiarities, essence, content, dialectic nature of correlation of business conflicts and organizational culture in developing countries (in the case of Ukraine. A special attention draws to preconditioned application of management potential of organization culture for maintaining management potential of organization culture for ensuring conflict management in business companies. The research showed that the internal reason for any business conflict cores in frameworks of interpersonal relations in the staff, which are conditioned under the impact of organization culture. This justifies its management significance in preventing and constructively resolving business conflicts in companies. The analysis of practice of management certifies that ignoring high management potential of organization culture and its inactivity in enterprises of Ukraine is a source of conflict-relatedness of social relations. The author suggests the principles to be followed in the formation of organizational culture. It will help to reduce the level of conflict in Ukrainian business organizations and will increase their efficiency and competitiveness.

  9. On the resolving power of 2-D interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Padula, Sandra S. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)

    1996-12-31

    A resonance gas model previously proposed is here briefly reviewed in order to illustrate some of the geometrical and dynamical effects that could distort the behavior of the two pion correlation function. The main of these effects - the resonance decaying into pions - has earlier been conceived as a possible means to probe resonance abundances at different energy ranges. However, reinforcing previous studies, we show here that the conventional 1-D projection of the correlation function does not allow for clear conclusions. Instead, we propose to use the 2-D projection associated to a 2-D {sub X}{sup 2} analysis, which substantially enhances the resolving power of interferometry to differentiate decoupling geometries of distinct dynamical models. This result is achieved by studying the variation of the mean {sub X}{sup 2} per degrees of freedom with respect to the range of the analysis in the ({sub qT}, {sub qL}) plane. The preliminary E802 data on Si + Au at 14.6 A GeV/c, used here for illustrating the method, seem to rule out dynamical models with high {omega}, {eta} resonance formation yields. (author) 24 refs., 5 figs.

  10. On the resolving power of 2-D interferometry

    International Nuclear Information System (INIS)

    Padula, Sandra S.

    1996-01-01

    A resonance gas model previously proposed is here briefly reviewed in order to illustrate some of the geometrical and dynamical effects that could distort the behavior of the two pion correlation function. The main of these effects - the resonance decaying into pions - has earlier been conceived as a possible means to probe resonance abundances at different energy ranges. However, reinforcing previous studies, we show here that the conventional 1-D projection of the correlation function does not allow for clear conclusions. Instead, we propose to use the 2-D projection associated to a 2-D X 2 analysis, which substantially enhances the resolving power of interferometry to differentiate decoupling geometries of distinct dynamical models. This result is achieved by studying the variation of the mean X 2 per degrees of freedom with respect to the range of the analysis in the ( qT , qL ) plane. The preliminary E802 data on Si + Au at 14.6 A GeV/c, used here for illustrating the method, seem to rule out dynamical models with high ω, η resonance formation yields. (author)

  11. Spatially and temporally resolved diagnostics for microsecond, intense electron beams

    International Nuclear Information System (INIS)

    Gilgenbach, R.M.; Brake, M.; Horton, L.D.; Bidwell, S.; Lucey, R.F.; Smutek, L.; Tucker, J.E.

    1985-01-01

    Experiments are underway to investigate new diagnostics for electron beams in vacuum and in a plasma background. Measured parameters include temporally resolved beam current profile and beam emittance. These characterizations are being performed during electron beam diode closure experiments (1) and beam-plasma interaction experiments with either of two long-pulse accelerators: MELBA (Michigan Electron Long Beam Accelerator): Voltage = -1 MV, Current = 10 kA, at Pulselength = 0.1 to 1μs (1.4μs) for voltage flat to within +.7% (+.10%). The second accelerator is a long-pulse Febetron with parameters: Voltage = -0.5 MV, Current = 1 kA, and Pulselength = 0.3 s. Two different configurations have been developed which use Cerenkov radiation to detect electron beam current profiles as a function of time. The first uses Cerenkov emission by electrons which impinge axially on a single fiberoptic lightguide enclosed in a lucite tube. Plasma light is blocked by graphite spray or thin foil covering the end of the optical fiber. This diagnostic has the following advantages: 1) The threshold energy for Cerenkov emission effectively discriminates between high energy beam electrons and low energy (3-5 eV) plasma electrons, 2) The small, nonconducting probe introduces a minimal perturbation into the beam-plasma system, 3) Excellent signal to noise ratio is obtained because the fiberoptic signal is directly transmitted to a photomultiplier tube in the Faraday cage, 4) Quantitative data is obtained directly

  12. Resolving the Milky Way and Nearby Galaxies with WFIRST

    Science.gov (United States)

    Kalirai, Jasonjot

    High-resolution studies of nearby stellar populations have served as a foundation for our quest to understand the nature of galaxies. Today, studies of resolved stellar populations constrain fundamental relations -- such as the initial mass function of stars, the time scales of stellar evolution, the timing of mass loss and amount of energetic feedback, the color-magnitude relation and its dependency on age and metallicity, the stellar-dark matter connection in galaxy halos, and the build up of stellar populations over cosmic time -- that represent key ingredients in our prescription to interpret light from the Universe and to measure the physical state of galaxies. More than in any other area of astrophysics, WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way and nearby galaxies. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. Our WFIRST GO Science Investigation Team (F) will develop three WFIRST (notional) GO programs related to resolved stellar populations to fully stress WFIRST's Wide Field Instrument. The programs will include a Survey of the Milky Way, a Survey of Nearby Galaxy Halos, and a Survey of Star-Forming Galaxies. Specific science goals for each program will be validated through a wide range of observational data sets, simulations, and new algorithms. As an output of this study, our team will deliver optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of MW environments and galaxy halos; cosmological simulations

  13. Seventh international conference on time-resolved vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, R.B.; Martinez, M.A.D.; Shreve, A.; Woodruff, W.H. [comps.

    1997-04-01

    The International Conference on Time-Resolved Vibrational Spectroscopy (TRVS) is widely recognized as the major international forum for the discussion of advances in this rapidly growing field. The 1995 conference was the seventh in a series that began at Lake Placid, New York, 1982. Santa Fe, New Mexico, was the site of the Seventh International Conference on Time-Resolved Vibrational Spectroscopy, held from June 11 to 16, 1995. TRVS-7 was attended by 157 participants from 16 countries and 85 institutions, and research ranging across the full breadth of the field of time-resolved vibrational spectroscopy was presented. Advances in both experimental capabilities for time-resolved vibrational measurements and in theoretical descriptions of time-resolved vibrational methods continue to occur, and several sessions of the conference were devoted to discussion of these advances and the associated new directions in TRVS. Continuing the interdisciplinary tradition of the TRVS meetings, applications of time-resolved vibrational methods to problems in physics, biology, materials science, and chemistry comprised a large portion of the papers presented at the conference.

  14. SPECTRALLY RESOLVED PURE ROTATIONAL LINES OF WATER IN PROTOPLANETARY DISKS

    International Nuclear Information System (INIS)

    Pontoppidan, Klaus M.; Salyk, Colette; Blake, Geoffrey A.; Kaeufl, Hans Ulrich

    2010-01-01

    We present ground-based high-resolution N-band spectra (Δv = 15 km s -1 ) of pure rotational lines of water vapor in two protoplanetary disks surrounding the pre-main-sequence stars AS 205N and RNO 90, selected based on detections of rotational water lines by the Spitzer InfraRed Spectrograph. Using VISIR on the Very Large Telescope, we spectrally resolve individual lines and show that they have widths of 30-60 km s -1 , consistent with an origin in Keplerian disks at radii of ∼1 AU. The water lines have similar widths to those of the CO at 4.67 μm, indicating that the mid-infrared water lines trace similar radii. The rotational temperatures of the water are 540 and 600 K in the two disks, respectively. However, the line ratios show evidence of non-LTE excitation, with low-excitation line fluxes being overpredicted by two-dimensional disk LTE models. Due to the limited number of observed lines and the non-LTE line ratios, an accurate measure of the water ortho/para (O/P) ratio is not available, but a best estimate for AS 205N is O/P =4.5 ± 1.0, apparently ruling out a low-temperature origin of the water. The spectra demonstrate that high-resolution spectroscopy of rotational water lines is feasible from the ground, and further that ground-based high-resolution spectroscopy is likely to significantly improve our understanding of the inner disk chemistry revealed by recent Spitzer observations.

  15. Exploring the limits to spatially resolved NMR

    Energy Technology Data Exchange (ETDEWEB)

    Gaedke, Achim; Nestle, Nikolaus [TU Darmstadt, Institute of Condensed Matter Physics (Germany)

    2010-07-01

    Recent advances in MRI have demonstrated resolutions down to 1 {mu}m. Magnetic resonance force microscopy has the potential to reach sensitivity for single nuclear spins. Given these numbers, in vivo imaging of single cells or even biomacromolecules may seem possible. However, for in vivo applications, there are fundamental differences in the contrast mechanisms compared to MRI at macroscopic scales as the length scale of of molecular self-diffusion exceeds that of the spatial resolution on the NMR time scale. Those effects - which are fundamentally different from the echo attenuation in field gradient NMR - even may lead to general limitations on the spatial resolution achievable in aqueous systems with high water content. In our contribution, we explore those effects on a model system in a high-resolution stray-field imaging setup. In addition to experimental results, simulations based on the Bloch-Torrey equation are presented.

  16. Ultrasensitive time-resolved immunofluorometric assay of pepsinogen I

    International Nuclear Information System (INIS)

    Huang Biao; Xiao Hualong; Zhang Xiangrui; Zhu Lan; Jiang Menjun

    2004-01-01

    Purpose: To construct a two-site sandwich-type assay for pepsinogen I with time-resolved fluoroimmunoassay (TRFIA) as a detection technique. Methods: On the noncompetitive assay, one monoclonal antibody (McAb) coating on wells directed against a specific antigenic site on the pepsinogen I, the europium-labelled McAb which was prepared by with helpful of the europium-chelate of N-(p-isothiocyanatobenzyl)- diethylenetriamine-N, N, N, N-tetraacetic acid directed against a different antigenic site on the pepsinogen I molecule we called labelling McAb. The luminescent enhancement system was enhancement solution which contained mainly 2-naphthoyltrifluoroacetone. 25μl of Calibrators or samples and 200 μl of the assay buffer were pipetted into coated microtiter wells. The plates were incubated with mechanical shaking for 1 h at 25 degree C, washed two times, then added 100 μl Eu3+- McAb solution diluted 50-fold in assay buffer. The plates were incubated again with mechanical shaking for 1 h at 25 degree C,After six washings, 200 μl of enhancement solution were dispense into each well. The plates were shaken for 5 min and fluorescence readings. All the proceeding were done by auto DELFIA1235, software was designed by our lab. The calibration curve and calculation of the concentrations in the unknown samples were performed automatically by using Multicalc software program, where a spline algorithm on logarithmically transformed data was employed. Results: The average labelling yield is 8.6 Eu3+/McAb giving high sensitivity with low background(<1000 cps). The measurement range was 3.5-328 μ g /L with ED25, ED50, ED80 of 11.34 ±0.2 μ g/L, 38.73±0.8 μ g /L and 132,3±2.9 μ g/L. The detection limit, defined as the concentration of PGI corresponding to the fluorescence of the zero calibrators plus two SDs, is 0..05μg/L. Within-run and between-run precision was l.9% and 4.7% which assessed at various PGI concentrations between 5 and 300 μg/L. We checked for cross

  17. Depth-Resolved Cathodoluminescence of Thorium Dioxide

    Science.gov (United States)

    2013-03-01

    plutonium-239 (239Pu)-based nuclear weapons. Thorium also results in less highly radioactive waste in comparison to the uranium fuels. Thorium is four...diameters (1/4 – 3/8”) (Mann & Thompson, 2010). The 99.99% ThO2 powder was placed into the ampoule with a basic mineralizer such as cesium fluoride...conversion ranging from 1 pA/V to 1 mA/V. The electrical noise is further reduced by cooling the PMT housing unit with liquid nitrogen as seen in

  18. Whole-genome analyses resolve early branches in the tree of life of modern birds

    DEFF Research Database (Denmark)

    Sicheritz-Pontén, Thomas; Li, Cai; Li, Bo

    2014-01-01

    To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister...... or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator...... and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high...

  19. Time-resolved X-ray scattering program at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Rodricks, B.

    1994-01-01

    The Time-Resolved Scattering Program's goal is the development of instruments and techniques for time-resolved studies. This entails the development of wide bandpass and focusing optics, high-speed detectors, mechanical choppers, and components for the measurement and creation of changes in samples. Techniques being developed are pump-probe experiments, single-bunch scattering experiments, high-speed white and pink beam Laue scattering, and nanosecond to microsecond synchronization of instruments. This program will be carried out primarily from a white-beam, bend-magnet source, experimental station, 1-BM-B, that immediately follows the first optics enclosure (1-BM-A). This paper will describe the experimental station and instruments under development to carry out the program

  20. Imaging by Electrochemical Scanning Tunneling Microscopy and Deconvolution Resolving More Details of Surfaces Nanomorphology

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    observed in high-resolution images of metallic nanocrystallites may be effectively deconvoluted, as to resolve more details of the crystalline morphology (see figure). Images of surface-crystalline metals indicate that more than a single atomic layer is involved in mediating the tunneling current......Upon imaging, electrochemical scanning tunneling microscopy (ESTM), scanning electrochemical micro-scopy (SECM) and in situ STM resolve information on electronic structures and on surface topography. At very high resolution, imaging processing is required, as to obtain information that relates...... to crystallographic-surface structures. Within the wide range of new technologies, those images surface features, the electrochemical scanning tunneling microscope (ESTM) provides means of atomic resolution where the tip participates actively in the process of imaging. Two metallic surfaces influence ions trapped...

  1. Time-resolved Neutron Powder Diffraction

    International Nuclear Information System (INIS)

    Pannetier, J.

    1986-01-01

    The use of a high-flux neutron source together with a large position sensitive detector (PSD) allows a powder diffraction pattern to be recorded at a time-scale of a few minutes so that crystalline systems under non-equilibrium conditions may now conveniently be investigated. This introduces a new dimension into powder diffraction (the time and transient phenomena like heterogeneous chemical reactions can now be easily studied. The instrumental parameters relevant for the design of such time-dependent experiments are briefly surveyed and the current limits of the method are discussed. The applications are illustrated by two kinds of experiment in the field of inorganic solid state chemistry: true kinetic studies of heterogeneous chemical reactions and thermodiffractometry experiments

  2. Resolving electrical conductivities from collisionally damped plasmons in isochorically heated warm dense aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fletcher, L. B. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Chung, H. -K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gamboa, E. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lee, H. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Omarbakiyeva, Y. [International IT Univ., Almaty (Kazakhstan); Univ. Rostock (Germany); Reinholz, H. [Univ. Rostock (Germany); ; Univ. of Western Australia, Crawley, WA (Australia); Ropke, G. [Univ. Rostock (Germany); Rosmej, S. [Univ. Rostock (Germany); Zastrau, U. [European XFEL, Hamburg (Germany); Glenzer, S. H. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-03-29

    We measure the highly-resolved inelastic x-ray scattering spectrum of isochorically ultrafast heated aluminum. In the x-ray forward scattering spectra the electron temperature could be measured from the down- and upshifted plasmon, where the electron density of ne = 1:8 1023 cm3 is known a priori. We have studied the plasmon damping by applying electron-particle collision models beyond the Born approximation determining the electrical conductivity of warm dense aluminum.

  3. Development of Field Angle Resolved Specific Heat Measurement System for Unconventional Superconductors

    International Nuclear Information System (INIS)

    Kitamura, Yasuhiro; Matsubara, Takeshi; Machida, Yo; Izawa, Koichi; Onuki, Yoshichika; Salce, Bernard; Flouquet, Jacques

    2015-01-01

    We developed a measurement system for field angle resolved specific heat under multiple extreme conditions at low temperature down to 50 mK, in magnetic field up to 7 T, and under high pressure up to 10 GPa. We demonstrated the performance of our developed system by measuring field angle dependence of specific heat of pressure induced unconventional superconductor CeIrSi 3

  4. Stimulated emission depletion microscopy resolves individual nitrogen vacancy centers in diamond nanocrystals.

    OpenAIRE

    Arroyo Camejo, S.; Adam, M.; Besbes, M.; Hugonin, J.; Jaques, V.; Greffet, J.; Roch, J.; Hell, S.; Treussart, F.

    2013-01-01

    Nitrogen-vacancy (NV) color centers in nanodiamonds are highly promising for bioimaging and sensing. However, resolving individual NV centers within nanodiamond particles and the controlled addressing and readout of their spin state has remained a major challenge. Spatially stochastic super-resolution techniques cannot provide this capability in principle, whereas coordinate-controlled super-resolution imaging methods, like stimulated emission depletion (STED) microscopy, have been predicted ...

  5. The impact of spatial resolution on resolving spatial precipitation patterns in the Himalayas

    OpenAIRE

    Bonekamp, P.N.J.; Collier, S.E.; Immerzeel, W.W.

    2017-01-01

    Frequently used gridded meteorological datasets poorly represent precipitation in the Himalaya due to their relatively low spatial resolution and the associated coarse representation of the complex topography. Dynamical downscaling using high-resolution atmospheric models may improve the accuracy and quality of the precipitation fields, as simulations at higher spatial resolution are more capable of resolving the interaction between the topography and the atmosphere. However, most physics par...

  6. Ionic classification of Xe laser lines: A new approach through time resolved spectroscopy

    International Nuclear Information System (INIS)

    Schinca, D.; Duchowicz, R.; Gallardo, M.

    1992-01-01

    Visible and UV laser emission from a highly ionized pulsed Xe plasma was studied in relation to the ionic assignment of the laser lines. Time-resolved spectroscopy was used to determine the ionic origin of the studied lines. The results are in agreement with an intensity versus pressure analysis performed over the same wavelength range. From the temporal behaviour of the spontaneous emission, a probable classification can be obtained. (author). 7 refs, 7 figs, 1 tab

  7. Electronic structure of Sr2RuO4 studied by angle-resolved photoemission spectroscopy

    International Nuclear Information System (INIS)

    Iwasawa, H.; Aiura, Y.; Saitoh, T.; Yoshida, Y.; Hase, I.; Ikeda, S.I.; Bando, H.; Kubota, M.; Ono, K.

    2007-01-01

    Electronic structure of the monolayer strontium ruthenate Sr 2 RuO 4 was investigated by high-resolution angle-resolved photoemission spectroscopy. We present photon-energy (hν) dependence of the electronic structure near the Fermi level along the ΓM line. The hν dependence has shown a strong spectral weight modulation of the Ru 4d xy and 4d zx bands

  8. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    Science.gov (United States)

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Time-resolved measurements of supersonic fuel sprays using synchrotron x-rays

    International Nuclear Information System (INIS)

    Powell, C.F.; Yue, Y.; Poola, R.; Wang, J.

    2000-11-01

    A time-resolved radiographic technique has been developed for probing the fuel distribution close to the nozzle of a high-pressure single-hole diesel injector. The measurement was made using X-ray absorption of monochromatic synchrotron-generated radiation, allowing quantitative determination of the fuel distribution in this optically impenetrable region with a time resolution of better than 1 μs. These quantitative measurements constitute the most detailed near-nozzle study of a fuel spray to date

  10. Time-resolved measurements of supersonic fuel sprays using synchrotron X-rays.

    Science.gov (United States)

    Powell, C F; Yue, Y; Poola, R; Wang, J

    2000-11-01

    A time-resolved radiographic technique has been developed for probing the fuel distribution close to the nozzle of a high-pressure single-hole diesel injector. The measurement was made using X-ray absorption of monochromatic synchrotron-generated radiation, allowing quantitative determination of the fuel distribution in this optically impenetrable region with a time resolution of better than 1 micros. These quantitative measurements constitute the most detailed near-nozzle study of a fuel spray to date.

  11. Resolving uncertainty in chemical speciation determinations

    Science.gov (United States)

    Smith, D. Scott; Adams, Nicholas W. H.; Kramer, James R.

    1999-10-01

    Speciation determinations involve uncertainty in system definition and experimentation. Identification of appropriate metals and ligands from basic chemical principles, analytical window considerations, types of species and checking for consistency in equilibrium calculations are considered in system definition uncertainty. A systematic approach to system definition limits uncertainty in speciation investigations. Experimental uncertainty is discussed with an example of proton interactions with Suwannee River fulvic acid (SRFA). A Monte Carlo approach was used to estimate uncertainty in experimental data, resulting from the propagation of uncertainties in electrode calibration parameters and experimental data points. Monte Carlo simulations revealed large uncertainties present at high (>9-10) and low (monoprotic ligands. Least-squares fit the data with 21 sites, whereas linear programming fit the data equally well with 9 sites. Multiresponse fitting, involving simultaneous fluorescence and pH measurements, improved model discrimination. Deconvolution of the excitation versus emission fluorescence surface for SRFA establishes a minimum of five sites. Diprotic sites are also required for the five fluorescent sites, and one non-fluorescent monoprotic site was added to accommodate the pH data. Consistent with greater complexity, the multiresponse method had broader confidence limits than the uniresponse methods, but corresponded better with the accepted total carboxylic content for SRFA. Overall there was a 40% standard deviation in total carboxylic content for the multiresponse fitting, versus 10% and 1% for least-squares and linear programming, respectively.

  12. Coarsely resolved topography along protein folding pathways

    Science.gov (United States)

    Fernández, Ariel; Kostov, Konstantin S.; Berry, R. Stephen

    2000-03-01

    The kinetic data from the coarse representation of polypeptide torsional dynamics described in the preceding paper [Fernandez and Berry, J. Chem. Phys. 112, 5212 (2000), preceding paper] is inverted by using detailed balance to obtain a topographic description of the potential-energy surface (PES) along the dominant folding pathway of the bovine pancreatic trypsin inhibitor (BPTI). The topography is represented as a sequence of minima and effective saddle points. The dominant folding pathway displays an overall monotonic decrease in energy with a large number of staircaselike steps, a clear signature of a good structure-seeker. The diversity and availability of alternative folding pathways is analyzed in terms of the Shannon entropy σ(t) associated with the time-dependent probability distribution over the kinetic ensemble of contact patterns. Several stages in the folding process are evident. Initially misfolded states form and dismantle revealing no definite pattern in the topography and exhibiting high Shannon entropy. Passage down a sequence of staircase steps then leads to the formation of a nativelike intermediate, for which σ(t) is much lower and fairly constant. Finally, the structure of the intermediate is refined to produce the native state of BPTI. We also examine how different levels of tolerance to mismatches of side chain contacts influence the folding kinetics, the topography of the dominant folding pathway, and the Shannon entropy. This analysis yields upper and lower bounds of the frustration tolerance required for the expeditious and robust folding of BPTI.

  13. Single Hit Energy-resolved Laue Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Shamim; Suggit, Matthew J.; Stubley, Paul G.; Ciricosta, Orlando; Wark, Justin S.; Higginbotham, Andrew [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Hawreliak, James A.; Collins, Gilbert W.; Eggert, Jon H. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Comley, Andrew J.; Foster, John M. [Atomic Weapons Establishment, Aldermaston, Reading RG7 4PR (United Kingdom)

    2015-05-15

    In situ white light Laue diffraction has been successfully used to interrogate the structure of single crystal materials undergoing rapid (nanosecond) dynamic compression up to megabar pressures. However, information on strain state accessible via this technique is limited, reducing its applicability for a range of applications. We present an extension to the existing Laue diffraction platform in which we record the photon energy of a subset of diffraction peaks. This allows for a measurement of the longitudinal and transverse strains in situ during compression. Consequently, we demonstrate measurement of volumetric compression of the unit cell, in addition to the limited aspect ratio information accessible in conventional white light Laue. We present preliminary results for silicon, where only an elastic strain is observed. VISAR measurements show the presence of a two wave structure and measurements show that material downstream of the second wave does not contribute to the observed diffraction peaks, supporting the idea that this material may be highly disordered, or has undergone large scale rotation.

  14. Single Hit Energy-resolved Laue Diffraction

    International Nuclear Information System (INIS)

    Patel, Shamim; Suggit, Matthew J.; Stubley, Paul G.; Ciricosta, Orlando; Wark, Justin S.; Higginbotham, Andrew; Hawreliak, James A.; Collins, Gilbert W.; Eggert, Jon H.; Comley, Andrew J.; Foster, John M.

    2015-01-01

    In situ white light Laue diffraction has been successfully used to interrogate the structure of single crystal materials undergoing rapid (nanosecond) dynamic compression up to megabar pressures. However, information on strain state accessible via this technique is limited, reducing its applicability for a range of applications. We present an extension to the existing Laue diffraction platform in which we record the photon energy of a subset of diffraction peaks. This allows for a measurement of the longitudinal and transverse strains in situ during compression. Consequently, we demonstrate measurement of volumetric compression of the unit cell, in addition to the limited aspect ratio information accessible in conventional white light Laue. We present preliminary results for silicon, where only an elastic strain is observed. VISAR measurements show the presence of a two wave structure and measurements show that material downstream of the second wave does not contribute to the observed diffraction peaks, supporting the idea that this material may be highly disordered, or has undergone large scale rotation

  15. Understanding healthcare professionals' self-efficacy to resolve interprofessional conflict.

    Science.gov (United States)

    Sexton, Martha; Orchard, Carole

    2016-05-01

    Conflict within interprofessional healthcare teams, when not effectively resolved, has been linked to detrimental consequences; however, effective conflict resolution has been shown to enhance team performance, increase patient safety, and improve patient outcomes. Alarmingly, knowledge of healthcare professionals' ability to resolve conflict has been limited, largely due to the challenges that arise when researchers attempt to observe a conflict occurring in real time. Research literature has identified three central components that seem to influence healthcare professional's perceived ability to resolve conflict: communication competence, problem-solving ability, and conflict resolution education and training. The purpose of this study was to investigate the impact of communication competence, problem-solving ability, and conflict resolution education and training on healthcare professionals' perceived ability to resolve conflicts. This study employed a cross-sectional survey design. Multiple regression analyses demonstrated that two of the three central components-conflict resolution education and training and communication competence-were found to be statistically significant predictors of healthcare professionals' perceived ability to resolve conflict. Implications include a call to action for clinicians and academicians to recognize the importance of communication competence and conflict resolution education and training as a vital area in interprofessional pre- and post-licensure education and collaborative practice.

  16. [A new measurement method of time-resolved spectrum].

    Science.gov (United States)

    Shi, Zhi-gang; Huang, Shi-hua; Liang, Chun-jun; Lei, Quan-sheng

    2007-02-01

    A new method for measuring time-resolved spectrum (TRS) is brought forward. Programming with assemble language controlled the micro-control-processor (AT89C51), and a kind of peripheral circuit constituted the drive circuit, which drived the stepping motor to run the monochromator. So the light of different kinds of expected wavelength could be obtained. The optical signal was transformed to electrical signal by optical-to-electrical transform with the help of photomultiplier tube (Hamamatsu 1P28). The electrical signal of spectrum data was transmitted to the oscillograph. Connecting the two serial interfaces of RS232 between the oscillograph and computer, the electrical signal of spectrum data could be transmitted to computer for programming to draw the attenuation curve and time-resolved spectrum (TRS) of the swatch. The method for measuring time-resolved spectrum (TRS) features parallel measurement in time scale but serial measurement in wavelength scale. Time-resolved spectrum (TRS) and integrated emission spectrum of Tb3+ in swatch Tb(o-BBA)3 phen were measured using this method. Compared with the real time-resolved spectrum (TRS). It was validated to be feasible, credible and convenient. The 3D spectra of fluorescence intensity-wavelength-time, and the integrated spectrum of the swatch Tb(o-BBA)3 phen are given.

  17. The Resolved Outflow from 3C 48

    Science.gov (United States)

    Shih, Hsin-Yi; Stockton, Alan

    2014-10-01

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 103-104 cm-3, the mass is ~6 × 106 M ⊙, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-11574. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Some of the

  18. Energy-resolved computed tomography: first experimental results

    International Nuclear Information System (INIS)

    Shikhaliev, Polad M

    2008-01-01

    First experimental results with energy-resolved computed tomography (CT) are reported. The contrast-to-noise ratio (CNR) in CT has been improved with x-ray energy weighting for the first time. Further, x-ray energy weighting improved the CNR in material decomposition CT when applied to CT projections prior to dual-energy subtraction. The existing CT systems use an energy (charge) integrating x-ray detector that provides a signal proportional to the energy of the x-ray photon. Thus, the x-ray photons with lower energies are scored less than those with higher energies. This underestimates contribution of lower energy photons that would provide higher contrast. The highest CNR can be achieved if the x-ray photons are scored by a factor that would increase as the x-ray energy decreases. This could be performed by detecting each x-ray photon separately and measuring its energy. The energy selective CT data could then be saved, and any weighting factor could be applied digitally to a detected x-ray photon. The CT system includes a photon counting detector with linear arrays of pixels made from cadmium zinc telluride (CZT) semiconductor. A cylindrical phantom with 10.2 cm diameter made from tissue-equivalent material was used for CT imaging. The phantom included contrast elements representing calcifications, iodine, adipose and glandular tissue. The x-ray tube voltage was 120 kVp. The energy selective CT data were acquired, and used to generate energy-weighted and material-selective CT images. The energy-weighted and material decomposition CT images were generated using a single CT scan at a fixed x-ray tube voltage. For material decomposition the x-ray spectrum was digitally spilt into low- and high-energy parts and dual-energy subtraction was applied. The x-ray energy weighting resulted in CNR improvement of calcifications and iodine by a factor of 1.40 and 1.63, respectively, as compared to conventional charge integrating CT. The x-ray energy weighting was also applied

  19. CMOS Time-Resolved, Contact, and Multispectral Fluorescence Imaging for DNA Molecular Diagnostics

    Directory of Open Access Journals (Sweden)

    Nan Guo

    2014-10-01

    Full Text Available Instrumental limitations such as bulkiness and high cost prevent the fluorescence technique from becoming ubiquitous for point-of-care deoxyribonucleic acid (DNA detection and other in-field molecular diagnostics applications. The complimentary metal-oxide-semiconductor (CMOS technology, as benefited from process scaling, provides several advanced capabilities such as high integration density, high-resolution signal processing, and low power consumption, enabling sensitive, integrated, and low-cost fluorescence analytical platforms. In this paper, CMOS time-resolved, contact, and multispectral imaging are reviewed. Recently reported CMOS fluorescence analysis microsystem prototypes are surveyed to highlight the present state of the art.

  20. An approach to spin-resolved molecular gas microscopy

    Science.gov (United States)

    Covey, Jacob P.; De Marco, Luigi; Acevedo, Óscar L.; Rey, Ana Maria; Ye, Jun

    2018-04-01

    Ultracold polar molecules are an ideal platform for studying many-body physics with long-range dipolar interactions. Experiments in this field have progressed enormously, and several groups are pursuing advanced apparatus for manipulation of molecules with electric fields as well as single-atom-resolved in situ detection. Such detection has become ubiquitous for atoms in optical lattices and tweezer arrays, but has yet to be demonstrated for ultracold polar molecules. Here we present a proposal for the implementation of site-resolved microscopy for polar molecules, and specifically discuss a technique for spin-resolved molecular detection. We use numerical simulation of spin dynamics of lattice-confined polar molecules to show how such a scheme would be of utility in a spin-diffusion experiment.

  1. Emerging biomedical applications of time-resolved fluorescence spectroscopy

    Science.gov (United States)

    Lakowicz, Joseph R.; Szmacinski, Henryk; Koen, Peter A.

    1994-07-01

    Time-resolved fluorescence spectroscopy is presently regarded as a research tool in biochemistry, biophysics, and chemical physics. Advances in laser technology, the development of long-wavelength probes, and the use of lifetime-based methods are resulting in the rapid migration of time-resolved fluorescence to the clinical chemistry lab, to the patient's bedside, to flow cytometers, to the doctor's office, and even to home health care. Additionally, time-resolved imaging is now a reality in fluorescence microscopy, and will provide chemical imaging of a variety of intracellular analytes and/or cellular phenomena. In this overview paper we attempt to describe some of the opportunities available using chemical sensing based on fluorescence lifetimes, and to predict those applications of lifetime-based sensing which are most likely in the near future.

  2. Resolved Companions of Cepheids as Seen by HST and XMM

    Science.gov (United States)

    Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio; Wolk, Scott J.; Guinan, Edward F.; Engle, Scott G.

    2016-01-01

    We have conducted a survey of 70 classical Cepheids with the Hubble Wide Field Camera3 (WFC3) to identify possible resolved companions. Data cover the range of 0.3" to 20" which typically corresponds to 200 AU to 0.1 pc. At present only possible companions greater than 5" from the Cepheid are discussed, since closer companions require a sophisticated point spread correction for the light of the much brighter Cepheid. We have followed up a subset of the possible resolved companions with XMM observations to determine whether they are young (X-ray active) enough to be physical companions of the Cepheids. We estimate that 4% of the Cepheids have a physical resolved companion, with the widest having a separation of 4000 AU. The one wider young star is in the field of S Nor, but since it is a cluster member, the companion is not assumed to be gravitationally bound to the Cepheid.

  3. Contrast in atomically resolved EF-SCEM imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng [National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); D’Alfonso, Adrian J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Hashimoto, Ayako [Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047 (Japan); Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan); Morgan, Andrew J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Takeguchi, Masaki [Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan); Mitsuishi, Kazutaka [Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Global Research Center for Environment and Energy based on Nanomaterials Science, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047 (Japan); Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan); Shimojo, Masayuki [Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5, Toyosu, Koto-ku, Tokyo, 135-8548 (Japan); Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Allen, Leslie J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Nellist, Peter D., E-mail: peter.nellist@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2013-11-15

    Energy-filtered scanning confocal electron microscopy (EF-SCEM) is a technique that uses the reduced depth of field of an aberration-corrected transmission electron microscope to provide three-dimensional (3D) compositional information. Using a silicon sample in the <110> orientation, we show that EF-SCEM image data can be recorded that shows lattice resolution in the plane perpendicular to the incident beam direction. The confocal effect is demonstrated through the reduction of the mean intensity as the confocal plane is displaced from the sample mid-plane, unlike optical sectioning in high-angle annular dark-field scanning transmission electron microscopy (STEM). Simulations of the EF-SCEM data show agreement with the experimental data, and allow the interpretability of the data to be explored. The effects of channelling, absorption and delocalisation complicate the quantitative and qualitative interpretation of the data, highlighting the need for matching to simulations. Finally the effects of the finite detector pin-hole aperture size are explored, and we show that the EF-SCEM contrast in the plane perpendicular to the beam direction starts to resemble that of a STEM spectrum imaging experiment as the aperture size increases. - Highlights: • Atomically resolved energy-filtered scanning confocal electron microscopy (EF-SCEM) is demonstrated. • The confocal effect is demonstrated through the reduction of the mean intensity as the confocal plane is displaced from the sample mid-plane. • Simulations show agreement with the experimental data. • The effects of channelling, absorption and delocalisation complicate the quantitative and qualitative interpretation of the data. • The effects of the finite detector pin-hole aperture size are explored.

  4. Contrast in atomically resolved EF-SCEM imaging

    International Nuclear Information System (INIS)

    Wang, Peng; D’Alfonso, Adrian J.; Hashimoto, Ayako; Morgan, Andrew J.; Takeguchi, Masaki; Mitsuishi, Kazutaka; Shimojo, Masayuki; Kirkland, Angus I.; Allen, Leslie J.; Nellist, Peter D.

    2013-01-01

    Energy-filtered scanning confocal electron microscopy (EF-SCEM) is a technique that uses the reduced depth of field of an aberration-corrected transmission electron microscope to provide three-dimensional (3D) compositional information. Using a silicon sample in the orientation, we show that EF-SCEM image data can be recorded that shows lattice resolution in the plane perpendicular to the incident beam direction. The confocal effect is demonstrated through the reduction of the mean intensity as the confocal plane is displaced from the sample mid-plane, unlike optical sectioning in high-angle annular dark-field scanning transmission electron microscopy (STEM). Simulations of the EF-SCEM data show agreement with the experimental data, and allow the interpretability of the data to be explored. The effects of channelling, absorption and delocalisation complicate the quantitative and qualitative interpretation of the data, highlighting the need for matching to simulations. Finally the effects of the finite detector pin-hole aperture size are explored, and we show that the EF-SCEM contrast in the plane perpendicular to the beam direction starts to resemble that of a STEM spectrum imaging experiment as the aperture size increases. - Highlights: • Atomically resolved energy-filtered scanning confocal electron microscopy (EF-SCEM) is demonstrated. • The confocal effect is demonstrated through the reduction of the mean intensity as the confocal plane is displaced from the sample mid-plane. • Simulations show agreement with the experimental data. • The effects of channelling, absorption and delocalisation complicate the quantitative and qualitative interpretation of the data. • The effects of the finite detector pin-hole aperture size are explored

  5. Time-resolved biophysical approaches to nucleocytoplasmic transport

    Directory of Open Access Journals (Sweden)

    Francesco Cardarelli

    Full Text Available Molecules are continuously shuttling across the nuclear envelope barrier that separates the nucleus from the cytoplasm. Instead of being just a barrier to diffusion, the nuclear envelope is rather a complex filter that provides eukaryotes with an elaborate spatiotemporal regulation of fundamental molecular processes, such as gene expression and protein translation. Given the highly dynamic nature of nucleocytoplasmic transport, during the past few decades large efforts were devoted to the development and application of time resolved, fluorescence-based, biophysical methods to capture the details of molecular motion across the nuclear envelope. These methods are here divided into three major classes, according to the differences in the way they report on the molecular process of nucleocytoplasmic transport. In detail, the first class encompasses those methods based on the perturbation of the fluorescence signal, also known as ensemble-averaging methods, which average the behavior of many molecules (across many pores. The second class comprises those methods based on the localization of single fluorescently-labelled molecules and tracking of their position in space and time, potentially across single pores. Finally, the third class encompasses methods based on the statistical analysis of spontaneous fluorescence fluctuations out of the equilibrium or stationary state of the system. In this case, the behavior of single molecules is probed in presence of many similarly-labelled molecules, without dwelling on any of them. Here these three classes, with their respective pros and cons as well as their main applications to nucleocytoplasmic shuttling will be briefly reviewed and discussed. Keywords: Fluorescence recovery after photobleaching, Single particle tracking, Fluorescence correlation spectroscopy, Diffusion, Transport, GFP, Nuclear pore complex, Live cell, Confocal microscopy

  6. RAiSE II: resolved spectral evolution in radio AGN

    Science.gov (United States)

    Turner, Ross J.; Rogers, Jonathan G.; Shabala, Stanislav S.; Krause, Martin G. H.

    2018-01-01

    The active galactic nuclei (AGN) lobe radio luminosities modelled in hydrodynamical simulations and most analytical models do not address the redistribution of the electron energies due to adiabatic expansion, synchrotron radiation and inverse-Compton scattering of cosmic microwave background photons. We present a synchrotron emissivity model for resolved sources that includes a full treatment of the loss mechanisms spatially across the lobe, and apply it to a dynamical radio source model with known pressure and volume expansion rates. The bulk flow and dispersion of discrete electron packets is represented by tracer fields in hydrodynamical simulations; we show that the mixing of different aged electrons strongly affects the spectrum at each point of the radio map in high-powered Fanaroff & Riley type II (FR-II) sources. The inclusion of this mixing leads to a factor of a few discrepancy between the spectral age measured using impulsive injection models (e.g. JP model) and the dynamical age. The observable properties of radio sources are predicted to be strongly frequency dependent: FR-II lobes are expected to appear more elongated at higher frequencies, while jetted FR-I sources appear less extended. The emerging FR0 class of radio sources, comprising gigahertz peaked and compact steep spectrum sources, can potentially be explained by a population of low-powered FR-Is. The extended emission from such sources is shown to be undetectable for objects within a few orders of magnitude of the survey detection limit and to not contribute to the curvature of the radio spectral energy distribution.

  7. RESOLVED IMAGES OF LARGE CAVITIES IN PROTOPLANETARY TRANSITION DISKS

    International Nuclear Information System (INIS)

    Andrews, Sean M.; Wilner, David J.; Espaillat, Catherine; Qi Chunhua; Brown, J. M.; Hughes, A. M.; Dullemond, C. P.; McClure, M. K.

    2011-01-01

    Circumstellar disks are thought to experience a rapid 'transition' phase in their evolution that can have a considerable impact on the formation and early development of planetary systems. We present new and archival high angular resolution (0.''3 ∼ 40-75 AU) Submillimeter Array (SMA) observations of the 880 μm (340 GHz) dust continuum emission from 12 such transition disks in nearby star-forming regions. In each case, we directly resolve a dust-depleted disk cavity around the central star. Using two-dimensional Monte Carlo radiative transfer calculations, we interpret these dust disk structures in a homogeneous, parametric model framework by reproducing their SMA continuum visibilities and spectral energy distributions. The cavities in these disks are large (R cav = 15-73 AU) and substantially depleted of small (∼μm-sized) dust grains, although their mass contents are still uncertain. The structures of the remnant material at larger radii are comparable to normal disks. We demonstrate that these large cavities are relatively common among the millimeter-bright disk population, comprising at least 1 in 5 (20%) of the disks in the bright half (and ≥26% of the upper quartile) of the millimeter luminosity (disk mass) distribution. Utilizing these results, we assess some of the physical mechanisms proposed to account for transition disk structures. As has been shown before, photoevaporation models do not produce the large cavity sizes, accretion rates, and disk masses representative of this sample. A sufficient decrease of the dust optical depths in these cavities by particle growth would be difficult to achieve: substantial growth (to meter sizes or beyond) must occur in large (tens of AU) regions of low turbulence without also producing an abundance of small particles. Given those challenges, we suggest instead that the observations are most commensurate with dynamical clearing due to tidal interactions with low-mass companions-very young (∼1 Myr) brown

  8. RESOLVE's Field Demonstration on Mauna Kea, Hawaii 2010

    Science.gov (United States)

    Captain, Janine; Quinn, Jacqueline; Moss, Thomas; Weis, Kyle

    2010-01-01

    In cooperation with the Canadian Space Agency, and the Northern Centre for Advanced Technology, Inc., NASA has undertaken the In-Situ Resource Utilization (ISRU) project called RESOLVE (Regolith and Environment Science & Oxygen and Lunar Volatile Extraction). This project is an Earth-based lunar precursor demonstration of a system that could be sent to explore permanently shadowed polar lunar craters, where it would drill into regolith, quantify the volatiles that are present, and extract oxygen by hydrogen reduction of iron oxides. The resulting water could be electrolyzed into oxygen to support exploration and hydrogen, which would be recycled through the process. The RESOLVE chemical processing system was mounted on a Canadian Space Agency mobility chasis and successfully demonstrated on Hawaii's Mauna Kea volcano in February 2010. The RESOLVE unit is the initial prototype of a robotic prospecting mission to the Moon. RESOLVE is designed to go to the poles of the Moon to "ground truth" the form and concentration of the hydrogen/water/hydroxyl that has been seen from orbit (M3, Lunar Prospector and LRO) and to test technologies to extract oxygen from the lunar regolith. RESOLVE has the ability to capture a one-meter core sample of lunar regolith and heat it to determine the volatiles that may be released and then demonstrate the production of oxygen from minerals found in the regolith. The RESOLVE project, which is led by KSC, is a multi-center and multi-organizational effort that includes representatives from KSC, JSC, GRC, the Canadian Space Agency, and the Northern Center for Advanced Technology (NORCAT). This paper details the results obtained from four days of lunar analog testing that included gas chromatograph analysis for volatile components, remote control of chemistry and drilling operations via satalite communications, and real-time water quantification using a novel capacitance measurement technique.

  9. The role of mediation in resolving workplace relationship conflict.

    Science.gov (United States)

    McKenzie, Donna Margaret

    2015-01-01

    Stress triggered by workplace-based interpersonal conflict can result in damaged relationships, loss of productivity, diminished job satisfaction and increasingly, workers' compensation claims for psychological injury. This paper examined the literature on the role and effectiveness of mediation, as the most common method of Alternative Dispute Resolution, in resolving workplace relationship conflict. Available evidence suggests that mediation is most effective when supported by organisational commitment to ADR strategies, policies and processes, and conducted by independent, experienced and qualified mediators. The United States Postal Service program REDRESS™ is described as an illustration of the successful use of mediation to resolve conflict in the workplace. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Spectrally resolved digital holography using a white light LED

    Science.gov (United States)

    Claus, D.; Pedrini, G.; Buchta, D.; Osten, W.

    2017-06-01

    This paper introduces the concept of spectrally resolved digital holography. The measurement principle and the analysis of the data will be discussed in detail. The usefulness of spectrally resolved digital holography is demonstrated for colour imaging and optical metrology with regards to the recovery of modulus information and phase information, respectively. The phase information will be used to measure the shape of an object via the application of the dual wavelength method. Based on the large degree of data available, multiple speckle de-correlated dual wavelength phase maps can be obtained, which when averaged result in a signal to noise ratio improvement.

  11. Atom-resolved AFM imaging of calcite nanoparticles in water

    Energy Technology Data Exchange (ETDEWEB)

    Imada, Hirotake; Kimura, Kenjiro [Department of Chemistry, School of Science, Kobe University, Rokko-dai, Nada, Kobe 657-8501 (Japan); Onishi, Hiroshi, E-mail: oni@kobe-u.ac.jp [Department of Chemistry, School of Science, Kobe University, Rokko-dai, Nada, Kobe 657-8501 (Japan)

    2013-06-20

    Highlights: ► An advanced frequency-modulation AFM (FM-AFM) was applied for imaging particles. ► Atom-resolved topography of nano-sized particles of calcite was observed in water. ► Locally ordered structures were found and assigned to a (104) facet of calcite. ► A promising ability of FM-AFM was demonstrated in imaging nano-sized particles. - Abstract: The atom-resolved topography of calcite nanoparticles was observed in water using a frequency-modulation atomic force microscope. Locally ordered structures were found and assigned to a (104) facet of crystalline calcite.

  12. Atom-resolved AFM imaging of calcite nanoparticles in water

    International Nuclear Information System (INIS)

    Imada, Hirotake; Kimura, Kenjiro; Onishi, Hiroshi

    2013-01-01

    Highlights: ► An advanced frequency-modulation AFM (FM-AFM) was applied for imaging particles. ► Atom-resolved topography of nano-sized particles of calcite was observed in water. ► Locally ordered structures were found and assigned to a (104) facet of calcite. ► A promising ability of FM-AFM was demonstrated in imaging nano-sized particles. - Abstract: The atom-resolved topography of calcite nanoparticles was observed in water using a frequency-modulation atomic force microscope. Locally ordered structures were found and assigned to a (104) facet of crystalline calcite

  13. Time-resolved emission from laser-ablated uranium

    International Nuclear Information System (INIS)

    Stoffels, E.; Mullen, J. van der; Weijer, P. van de

    1991-01-01

    Time-resolved emission spectra from the plasma, induced by laser ablation of uranium samples have been studied. The dependence of the emission intensity on time is strongly affected by the nature and pressure of the buffer gas. Air and argon have been used in the pressure range 0.002 to 5 mbar. The emission intensity as a function of time displays three maxima, indicating that three different processes within the expanding plasma plume are involved. On basis of the time-resolved spectra we propose a model that explains qualitatively the phenomena that are responsible for this time behaviour. (author)

  14. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources.

    Science.gov (United States)

    Rutherford, Michael E; Chapman, David J; White, Thomas G; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E

    2016-05-01

    The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits).

  15. Particle tracking during Ostwald ripening using time-resolved laboratory X-ray microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Werz, T., E-mail: thomas.werz@uni-ulm.de [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany); Baumann, M. [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany); Wolfram, U. [Ulm University, Institute of Orthopaedic Research and Biomechanics, Helmholtzstrasse 14, 89081 (Germany); Krill, C.E. [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany)

    2014-04-01

    Laboratory X-ray microtomography is investigated as a method for obtaining time-resolved images of microstructural coarsening of the semisolid state of Al–5 wt.% Cu samples during Ostwald ripening. Owing to the 3D imaging capability of tomography, this technique uniquely provides access to the growth rates of individual particles, thereby not only allowing a statistical characterization of coarsening—as has long been possible by conventional metallography—but also enabling quantification of the influence of local environment on particle boundary migration. The latter information is crucial to understanding growth kinetics during Ostwald ripening at high volume fractions of the coarsening phase. Automated image processing and segmentation routines were developed to close gaps in the network of particle boundaries and to track individual particles from one annealing step to the next. The particle tracking success rate places an upper bound of only a few percent on the likelihood of segmentation errors for any given particle. The accuracy of particle size trajectories extracted from the time-resolved tomographic reconstructions is correspondingly high. Statistically averaged coarsening data and individual particle growth rates are in excellent agreement with the results of prior experimental studies and with computer simulations of Ostwald ripening. - Highlights: • Ostwald ripening in Al–5 wt.% Cu measured by laboratory X-ray microtomography • Time-resolved measurement of individual particle growth • Automated segmentation routines developed to close gaps in particle boundary network • Particle growth/shrinkage rates deviate from LSW model prediction.

  16. Validation of an hourly resolved global aerosol model in answer to solar electricity generation information needs

    Directory of Open Access Journals (Sweden)

    M. Schroedter-Homscheidt

    2013-04-01

    Full Text Available Solar energy applications need global aerosol optical depth (AOD information to derive historic surface solar irradiance databases from geostationary meteorological satellites reaching back to the 1980's. This paper validates the MATCH/DLR model originating in the climate community against AERONET ground measurements. Hourly or daily mean AOD model output is evaluated individually for all stations in Europe, Africa and the Middle East – an area highly interesting for solar energy applications being partly dominated by high aerosol loads. Overall, a bias of 0.02 and a root-mean-square error (RMSE of 0.23 are found for daily mean AOD values, while the RMSE increases to 0.28 for hourly mean AOD values. Large differences between various regions and stations are found providing a feedback loop for the aerosol modelling community. The difference in using daily means versus hourly resolved modelling with respect to hourly resolved observations is evaluated. Nowadays state-of-the-art in solar resource assessment relies on monthly turbidity or AOD climatologies while at least hourly resolved irradiance time series are needed by the solar sector. Therefore, the contribution of higher temporally modelled AOD is evaluated.

  17. Method for enhancing the resolving power of ion mobility separations over a limited mobility range

    Science.gov (United States)

    Shvartsburg, Alexandre A; Tang, Keqi; Smith, Richard D

    2014-09-23

    A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

  18. Time-resolved measurements with intense ultrashort laser pulses: a 'molecular movie' in real time

    International Nuclear Information System (INIS)

    Rudenko, A; Ergler, Th; Feuerstein, B; Zrost, K; Schroeter, C D; Moshammer, R; Ullrich, J

    2007-01-01

    We report on the high-resolution multidimensional real-time mapping of H 2 + and D 2 + nuclear wave packets performed employing time-resolved three-dimensional Coulomb explosion imaging with intense laser pulses. Exploiting a combination of a 'reaction microscope' spectrometer and a pump-probe setup with two intense 6-7 fs laser pulses, we simultaneously visualize both vibrational and rotational motion of the molecule, and obtain a sequence of snapshots of the squared ro-vibrational wave function with time-step resolution of ∼ 0.3 fs, allowing us to reconstruct a real-time movie of the ultrafast molecular motion. We observe fast dephasing, or 'collapse' of the vibrational wave packet and its subsequent revival, as well as signatures of rotational excitation. For D 2 + we resolve also the fractional revivals resulting from the interference between the counter-propagating parts of the wave packet

  19. Creating diversified response profiles from a single quenchometric sensor element by using phase-resolved luminescence.

    Science.gov (United States)

    Tehan, Elizabeth C; Bukowski, Rachel M; Chodavarapu, Vamsy P; Titus, Albert H; Cartwright, Alexander N; Bright, Frank V

    2015-01-05

    We report a new strategy for generating a continuum of response profiles from a single luminescence-based sensor element by using phase-resolved detection. This strategy yields reliable responses that depend in a predictable manner on changes in the luminescent reporter lifetime in the presence of the target analyte, the excitation modulation frequency, and the detector (lock-in amplifier) phase angle. In the traditional steady-state mode, the sensor that we evaluate exhibits a linear, positive going response to changes in the target analyte concentration. Under phase-resolved conditions the analyte-dependent response profiles: (i) can become highly non-linear; (ii) yield negative going responses; (iii) can be biphasic; and (iv) can exhibit super sensitivity (e.g., sensitivities up to 300 fold greater in comparison to steady-state conditions).

  20. Time-resolved UV-excited microarray reader for fluorescence energy transfer (FRET) measurements

    Science.gov (United States)

    Orellana, Adelina; Hokkanen, Ari P.; Pastinen, Tomi; Takkinen, Kristina; Soderlund, Hans

    2001-05-01

    Analytical systems based on immunochemistry are largely used in medical diagnostics and in biotechnology. There is a significant pressure to develop the present assay formats to become easier to use, faster, and less reagent consuming. Further developments towards high density array--like multianalyte measurement systems would be valuable. To this aim we have studied the applicability of fluorescence resonance energy transfer and time-resolved fluorescence resonance energy transfer in immunoassays on microspots and in microwells. We have used engineered recombinant antibodies detecting the pentameric protein CRP as a model analyte system, and tested different assay formats. We describe also the construction of a time-resolved scanning epifluorometer with which we could measure the FRET interaction between the slow fluorescence decay from europium chelates and its energy transfer to the rapidly decaying fluorophore Cy5.

  1. Time-resolved x-ray line diagnostics of laser-produced plasmas

    International Nuclear Information System (INIS)

    Kauffman, R.L.; Matthews, D.L.; Kilkenny, J.D.; Lee, R.W.

    1982-11-01

    We have examined the underdense plasma conditions of laser irradiated disks using K x-rays from highly ionized ions. A 900 ps laser pulse of 0.532 μm light is used to irradiate various Z disks which have been doped with low concentrations of tracer materials. The tracers, whose Z's range from 13 to 22, are chosen so that their K x-ray spectrum is sensitive to typical underdense plasma temperatures and densities. Spectra are measured using a time-resolved crystal spectrograph recording the time history of the x-ray spectrum. A spatially-resolved, time-integrated crystal spectrograph also monitors the x-ray lines. Large differences in Al spectra are observed when the host plasms is changed from SiO 2 to PbO or In. Spectra will be presented along with preliminary analysis of the data

  2. Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

    Science.gov (United States)

    Rudge, J; Xu, H; Kolthammer, J; Hong, Y K; Choi, B C

    2015-02-01

    We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

  3. Broad-band time-resolved near infrared spectroscopy in the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.C.; Pastor, I.; Cal, E. de la; McCarthy, K.J. [Laboratorio Nacional de Fusion, CIEMAT, Madrid (Spain); Diaz, D. [Universidad Autonoma de Madrid, Dept Quimica Fisica Aplicada, Madrid (Spain)

    2014-11-15

    First experimental results on broad-band, time-resolved Near Infrared (NIR;here loosely defined as covering from 750 to 1650 nm) passive spectroscopy using a high sensitivity InGaAs detector are reported for the TJ-II Stellarator. Experimental set-up is described together with its main characteristics, the most remarkable ones being its enhanced NIR response, broadband spectrum acquisition in a single shot, and time-resolved measurements with up to 1.8 kHz spectral rate. Prospects for future work and more extended physics studies in this newly open spectral region in TJ-II are discussed. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. On-chip, photon-number-resolving, telecommunication-band detectors for scalable photonic information processing

    Energy Technology Data Exchange (ETDEWEB)

    Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice; Tomlin, Nathan A.; Fox, Anna E.; Linares, Antia Lamas; Mirin, Richard P.; Nam, Sae Woo [National Institute of Standards and Technology, Boulder, Colorado, 80305 (United States); Thomas-Peter, Nicholas; Metcalf, Benjamin J.; Spring, Justin B.; Langford, Nathan K.; Walmsley, Ian A. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Gates, James C.; Smith, Peter G. R. [Optoelectronics Research Centre, University of Southampton, Highfield SO17 1BJ (United Kingdom)

    2011-12-15

    Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.

  5. Angle-resolved photoemission investigation of SmB{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Hlawenka, Peter; Rader, Oliver; Siemensmeyer, Konrad; Weschke, Eugen; Varykhalov, Andrei; Rienks, Emile [Helmholtz-Zentrum Berlin (Germany); Shitsevalova, Natalya [Institute for Problems of Material Science, Kiev (Ukraine); Gabani, Slavomir; Flachbart, Karol [IEP, Slovak Academy of Science, Kosice (Slovakia)

    2015-07-01

    Recently the mixed valence compound SmB{sub 6} has drawn great attention. Theoretically predicted surface states, which should result from a hybridisation of localised f-bands with conduction electrons and a band inversion, would make SmB{sub 6} the first realisation of a so called topological Kondo insulator. Conductivity and transport measurements, as well as spin-resolved photoemission spectroscopy seem to fortify the scenario of a topological nature of the conductive surface. We investigate the surface electronic structure of SmB{sub 6} by means of high resolution angle-resolved photoemission spectroscopy measurements below 1 K. We will present new insights into the surface states that determine the low temperature conductivity of this material.

  6. Time-resolved x-ray line diagnostics of laser-produced plasmas

    International Nuclear Information System (INIS)

    Kauffman, R.L.; Matthews, D.L.; Kilkenny, J.D.; Lee, R.W.

    1982-01-01

    We have examined the underdense plasma conditions of laser irradiated disks using K x-rays from highly ionized ions. A 900 ps laser pulse of 0.532 μm light is used to irradiate various Z disks which have been doped with low concentrations of tracer materials. The tracers whose Z's range from 13 to 22 are chosen so that their K x-ray spectrum is sensitive to typical underdense plasma temperatures and densities. Spectra are measured using a time-resolved crystal spectrograph recording the time history of the x-ray spectrum. A spatially-resolved, time-integrated crystal spectrograph also monitors the x-ray lines. Large differences in Al spectra are observed when the host plasma is changed from SiO 2 to PbO or In. Spectra will be presented along with preliminary analysis of the data

  7. Spatially Resolving Ocean Color and Sediment Dispersion in River Plumes, Coastal Systems, and Continental Shelf Waters

    Science.gov (United States)

    Aurin, Dirk Alexander; Mannino, Antonio; Franz, Bryan

    2013-01-01

    Satellite remote sensing of ocean color in dynamic coastal, inland, and nearshorewaters is impeded by high variability in optical constituents, demands specialized atmospheric correction, and is limited by instrument sensitivity. To accurately detect dispersion of bio-optical properties, remote sensors require ample signal-to-noise ratio (SNR) to sense small variations in ocean color without saturating over bright pixels, an atmospheric correction that can accommodate significantwater-leaving radiance in the near infrared (NIR), and spatial and temporal resolution that coincides with the scales of variability in the environment. Several current and historic space-borne sensors have met these requirements with success in the open ocean, but are not optimized for highly red-reflective and heterogeneous waters such as those found near river outflows or in the presence of sediment resuspension. Here we apply analytical approaches for determining optimal spatial resolution, dominant spatial scales of variability ("patches"), and proportions of patch variability that can be resolved from four river plumes around the world between 2008 and 2011. An offshore region in the Sargasso Sea is analyzed for comparison. A method is presented for processing Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua and Terra imagery including cloud detection, stray lightmasking, faulty detector avoidance, and dynamic aerosol correction using short-wave- and near-infrared wavebands in extremely turbid regions which pose distinct optical and technical challenges. Results showthat a pixel size of approx. 520 mor smaller is generally required to resolve spatial heterogeneity in ocean color and total suspended materials in river plumes. Optimal pixel size increases with distance from shore to approx. 630 m in nearshore regions, approx 750 m on the continental shelf, and approx. 1350 m in the open ocean. Greater than 90% of the optical variability within plume regions is resolvable with

  8. Spatially resolved D-T(2) correlation NMR of porous media.

    Science.gov (United States)

    Zhang, Yan; Blümich, Bernhard

    2014-05-01

    Within the past decade, 2D Laplace nuclear magnetic resonance (NMR) has been developed to analyze pore geometry and diffusion of fluids in porous media on the micrometer scale. Many objects like rocks and concrete are heterogeneous on the macroscopic scale, and an integral analysis of microscopic properties provides volume-averaged information. Magnetic resonance imaging (MRI) resolves this spatial average on the contrast scale set by the particular MRI technique. Desirable contrast parameters for studies of fluid transport in porous media derive from the pore-size distribution and the pore connectivity. These microscopic parameters are accessed by 1D and 2D Laplace NMR techniques. It is therefore desirable to combine MRI and 2D Laplace NMR to image functional information on fluid transport in porous media. Because 2D Laplace resolved MRI demands excessive measuring time, this study investigates the possibility to restrict the 2D Laplace analysis to the sum signals from low-resolution pixels, which correspond to pixels of similar amplitude in high-resolution images. In this exploratory study spatially resolved D-T2 correlation maps from glass beads and mortar are analyzed. Regions of similar contrast are first identified in high-resolution images to locate corresponding pixels in low-resolution images generated with D-T2 resolved MRI for subsequent pixel summation to improve the signal-to-noise ratio of contrast-specific D-T2 maps. This method is expected to contribute valuable information on correlated sample heterogeneity from the macroscopic and the microscopic scales in various types of porous materials including building materials and rock. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Resolving Semantic Interference during Word Production Requires Central Attention

    Science.gov (United States)

    Kleinman, Daniel

    2013-01-01

    The semantic picture-word interference task has been used to diagnose how speakers resolve competition while selecting words for production. The attentional demands of this resolution process were assessed in 2 dual-task experiments (tone classification followed by picture naming). In Experiment 1, when pictures and distractor words were presented…

  10. Resolving ambiguities in reconstructed grain maps using discrete tomography

    DEFF Research Database (Denmark)

    Alpers, A.; Knudsen, E.; Poulsen, H.F.

    2005-01-01

    reconstruct the image from diffraction data, but they are often unable to assign unambiguous values to all pixels. We present an approach that resolves these ambiguous pixels by using a Monte Carlo technique that exploits the discrete nature of the problem and utilizes proven methods of discrete tomography...

  11. Energy- and angled-resolved photoelectron spectroscopy of negative ions

    International Nuclear Information System (INIS)

    Pegg, D.J.; Thompson, J.S.; Compton, R.N.; Alton, G.D.

    1988-01-01

    Energy- and angle-resolved photoelectron detachment spectroscopy is currently being used to investigate the structure of negative ions and their interaction with radiation. Measurements of the electron affinity of the Ca atom and the partial cross sections for photodetachment of the metastable negative ion, He - (1s2s2p 4 P), are reported. 5 refs., 5 figs

  12. Time resolved two- and three-dimensional plasma diagnostics

    International Nuclear Information System (INIS)

    1991-03-01

    This collection of papers on diagnostics in fusion plasmas contains work on the data analysis of inverse problems and on the experimental arrangements presently used to obtain spatially and temporally resolved plasma radial profiles, including electron and ion temperature, plasma density and plasma current profiles. Refs, figs and tabs

  13. Multi-frame pyramid correlation for time-resolved PIV

    NARCIS (Netherlands)

    Sciacchitano, A.; Scarano, F.; Wieneke, B.

    2012-01-01

    A novel technique is introduced to increase the precision and robustness of time-resolved particle image velocimetry (TR-PIV) measurements. The innovative element of the technique is the linear combination of the correlation signal computed at different separation time intervals. The domain of the

  14. 48 CFR 2052.242-70 - Resolving differing professional views.

    Science.gov (United States)

    2010-10-01

    ... resolution of differing professional views (DPVs) of health and safety related concerns associated with the... professional views. 2052.242-70 Section 2052.242-70 Federal Acquisition Regulations System NUCLEAR REGULATORY....242-70 Resolving differing professional views. As prescribed in 2042.570-1, the contracting officer...

  15. Magnetic Resonance Microscopy Spatially Resolved NMR Techniques and Applications

    CERN Document Server

    Codd, Sarah

    2008-01-01

    This handbook and ready reference covers materials science applications as well as microfluidic, biomedical and dental applications and the monitoring of physicochemical processes. It includes the latest in hardware, methodology and applications of spatially resolved magnetic resonance, such as portable imaging and single-sided spectroscopy. For materials scientists, spectroscopists, chemists, physicists, and medicinal chemists.

  16. Resolving a protracted refugee situation through a regional process

    Directory of Open Access Journals (Sweden)

    Olga Mitrovic

    2015-09-01

    Full Text Available Protracted refugee situations are usually a result of political deadlock, and their resolution demands the involvement of a range of actors and a multifaceted approach focused on leveraging political will. Despite its shortcomings, the Regional Process in the Western Balkans offers a number of lessons for resolving such situations.

  17. Time Resolved Broadband Terahertz Relaxation Dynamics of Electron in Water

    DEFF Research Database (Denmark)

    Wang, Tianwu; Iwaszczuk, Krzysztof; Cooke, David G.

    We investigated the transient response of the solvated electron in water ejected by photodetachment from potassium ferrocyanide using time resolved terahertz spectroscopy (TSTS). Ultrabroadband THz transients are generated and detected by a two-color femtosecond-induced air plasma and air biased...

  18. Children's Use of Gesture to Resolve Lexical Ambiguity

    Science.gov (United States)

    Kidd, Evan; Holler, Judith

    2009-01-01

    We report on a study investigating 3-5-year-old children's use of gesture to resolve lexical ambiguity. Children were told three short stories that contained two homonym senses; for example, "bat" (flying mammal) and "bat" (sports equipment). They were then asked to re-tell these stories to a second experimenter. The data were coded for the means…

  19. Resolving runaway electron distributions in space, time, and energy

    Science.gov (United States)

    Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P.; Eidietis, N. W.; Lvovskiy, A.; Pace, D. C.; Brennan, D. P.; Hollmann, E. M.; Liu, C.; Moyer, R. A.; Shiraki, D.

    2018-05-01

    Areas of agreement and disagreement with present-day models of runaway electron (RE) evolution are revealed by measuring MeV-level bremsstrahlung radiation from runaway electrons (REs) with a pinhole camera. Spatially resolved measurements localize the RE beam, reveal energy-dependent RE transport, and can be used to perform full two-dimensional (energy and pitch-angle) inversions of the RE phase-space distribution. Energy-resolved measurements find qualitative agreement with modeling on the role of collisional and synchrotron damping in modifying the RE distribution shape. Measurements are consistent with predictions of phase-space attractors that accumulate REs, with non-monotonic features observed in the distribution. Temporally resolved measurements find qualitative agreement with modeling on the impact of collisional and synchrotron damping in varying the RE growth and decay rate. Anomalous RE loss is observed and found to be largest at low energy. Possible roles for kinetic instability or spatial transport to resolve these anomalies are discussed.

  20. Time-resolved fluorescence analysis of the mobile flavin cofactor

    Indian Academy of Sciences (India)

    Conformational heterogeneity of the FAD cofactor in -hydroxybenzoate hydroxylase (PHBH) was investigated with time-resolved polarized flavin fluorescence. For binary enzyme/substrate (analogue) complexes of wild-type PHBH and Tyr222 mutants, crystallographic studies have revealed two distinct flavin conformations ...