WorldWideScience

Sample records for single particle detection

  1. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  2. Optical Detection and Sizing of Single Nano-Particles Using Continuous Wetting Films

    Science.gov (United States)

    Hennequin, Yves; McLeod, Euan; Mudanyali, Onur; Migliozzi, Daniel; Ozcan, Aydogan; Dinten, Jean-Marc

    2013-01-01

    The physical interaction between nano-scale objects and liquid interfaces can create unique optical properties, enhancing the signatures of the objects with sub-wavelength features. Here we show that the evaporation on a wetting substrate of a polymer solution containing sub-micrometer or nano-scale particles creates liquid micro-lenses that arise from the local deformations of the continuous wetting film. These micro-lenses have properties similar to axicon lenses that are known to create beams with a long depth of focus. This enhanced depth of focus allows detection of single nanoparticles using a low magnification microscope objective lens, achieving a relatively wide field-of-view, while also lifting the constraints on precise focusing onto the object plane. Hence, by creating these liquid axicon lenses through spatial deformations of a continuous thin wetting film, we transfer the challenge of imaging individual nano-particles to detecting the light focused by these lenses. As a proof of concept, we demonstrate the detection and sizing of single nano-particles (100 and 200 nm), CpGV granuloviruses as well as Staphylococcus epidermidis bacteria over a wide field of view of e.g., 5.10×3.75 mm2 using a ×5 objective lens with a numerical aperture of 0.15. In addition to conventional lens-based microscopy, this continuous wetting film based approach is also applicable to lensfree computational on-chip imaging, which can be used to detect single nano-particles over a large field-of-view of e.g., >20-30 mm2. These results could be especially useful for high-throughput field-analysis of nano-scale objects using compact and cost-effective microscope designs. PMID:23889001

  3. Technical Note: The single particle soot photometer fails to reliably detect PALAS soot nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Gysel

    2012-12-01

    Full Text Available The single particle soot photometer (SP2 uses laser-induced incandescence (LII for the measurement of atmospheric black carbon (BC particles. The BC mass concentration is obtained by combining quantitative detection of BC mass in single particles with a counting efficiency of 100% above its lower detection limit. It is commonly accepted that a particle must contain at least several tenths of a femtogram BC in order to be detected by the SP2.

    Here we show the result that most BC particles from a PALAS spark discharge soot generator remain undetected by the SP2, even if their BC mass, as independently determined with an aerosol particle mass analyser (APM, is clearly above the typical lower detection limit of the SP2. Comparison of counting efficiency and effective density data of PALAS soot with flame generated soot (combustion aerosol standard burner, CAST, fullerene soot and carbon black particles (Cabot Regal 400R reveals that particle morphology can affect the SP2's lower detection limit. PALAS soot particles are fractal-like agglomerates of very small primary particles with a low fractal dimension, resulting in a very low effective density. Such loosely packed particles behave like "the sum of individual primary particles" in the SP2's laser. Accordingly, most PALAS soot particles remain undetected as the SP2's laser intensity is insufficient to heat the primary particles to their vaporisation temperature because of their small size (Dpp ≈ 5–10 nm. Previous knowledge from pulsed laser-induced incandescence indicated that particle morphology might have an effect on the SP2's lower detection limit, however, an increase of the lower detection limit by a factor of ∼5–10, as reported here for PALAS soot, was not expected.

    In conclusion, the SP2's lower detection limit at a certain laser power depends primarily on the total BC mass per particle for compact particles with sufficiently high effective

  4. Detection of lead nanoparticles in game meat by single particle ICP-MS following use of lead-containing bullets.

    Science.gov (United States)

    Kollander, Barbro; Widemo, Fredrik; Ågren, Erik; Larsen, Erik H; Loeschner, Katrin

    2017-03-01

    This study investigated whether game meat may contain nanoparticles of lead from ammunition. Lead nanoparticles in the range 40 to 750 nm were detected by ICP-MS in single particle mode in game shot with lead-containing bullets. The median diameter of the detected nanoparticles was around 60 nm. The particle mass concentration ranged from 290 to 340 ng/g meat and the particle number concentrations from 27 to 50 million particles/g meat. The size limit of detection strongly depended on the level of dissolved lead and was in the range of 40 to 80 nm. In game meat sampled more than 10 cm away from the wound channel, no lead particles with a diameter larger than 40 nm were detected. In addition to dissolved lead in meat that originated from particulates, the presence of lead nano particles in game meat represents a hitherto unattended source of lead with a largely unknown toxicological impact to humans. Graphical Abstract Detection of lead nanoparticles in game meat by single particle ICP-MS following use of leadcontaining bullets.

  5. Mobility and height detection of particle labels in an optical evanescent wave biosensor with single-label resolution

    Energy Technology Data Exchange (ETDEWEB)

    Van Ommering, Kim; Koets, Marjo; Schleipen, Jean J H B; Prins, Menno W J [Philips Research Laboratories, 5656 AE Eindhoven (Netherlands); Somers, Philip A; Van IJzendoorn, Leo J, E-mail: menno.prins@philips.co [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

    2010-04-21

    Particle labels are used in biosensors to detect the presence and concentration of analyte molecules. In this paper we demonstrate an optical technique to measure the mobility and height of bound particle labels on a biosensor surface with single-label resolution. The technique is based on the detection of the particle-induced light scattering in an optical evanescent field. We show that the thermal particle motion in the optical evanescent field leads to intensity fluctuations that can accurately be detected. The technique is demonstrated using 290 bp (99 nm) DNA as an analyte and using polystyrene particles and magnetic particles with diameters between 500 and 1000 nm as labels. The particle intensity histograms show that quantitative height measurements are obtained for particles with uniform optical properties, and the intensity versus position plots reflect the analyte-antibody orientation and the analyte flexibility. The novel optical detection technique will lead to biosensors with very high sensitivity and specificity.

  6. Detection and characterisation of aluminium-containing nanoparticles in Chinese noodles by single particle ICP-MS.

    Science.gov (United States)

    Loeschner, Katrin; Correia, Manuel; López Chaves, Carlos; Rokkjær, Inge; Sloth, Jens J

    2018-01-01

    This study investigated Chinese noodles for the presence of aluminium-containing nanoparticles by using inductively coupled plasma mass spectrometry in single particle mode (spICP-MS) after enzymatic digestion by α-amylase. The aluminium concentrations in the noodle samples, determined by conventional ICP-MS without or with the use of hydrofluoric acid for digestion, were 5.4 ± 1.9 µg/g and 10.1 ± 2.2 µg/g (N = 21), respectively. Aluminium-containing nanoparticles were detected by spICP-MS in all 21 samples. Depending on the assumed particle composition, Al 2 O 3 or Al 2 O 3 ∙2SiO 2 ∙2H 2 O, the median particle diameters were either below or above 100 nm, respectively. The minimum detectable particle diameter by spICP-MS was between 54 and 83 nm. The mass recovery of aluminium in the form of particles was between 5% and 18%. The presented work reports for the first time the detection of Al-containing particles in food by spICP-MS.

  7. Detection of charged particles with a methylammonium lead tribromide perovskite single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiang [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Wei, Haotong; Wei, Wei [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Chuirazzi, William; DeSantis, Dylan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Huang, Jinsong, E-mail: jhuang2@unl.edu [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Cao, Lei, E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2017-03-11

    Methylammonium lead tribromide (MAPbBr{sub 3}) perovskite crystals have attracted significant attention due to their attractive performance in various optoelectronic applications such as solar cells, light-emitting devices, photodetectors, and recently in X-ray detectors. In this study, we demonstrate a possible use of perovskite-based devices for detection of charged particles (which can be applied in basic scientific research, health physics, and environmental analysis) and investigate the mechanism of fundamental charge transport inside perovskite crystals. It was found that inexpensive MAPbBr{sub 3} single crystals could be used for measuring the energy spectrum of charged particles through direct collection of the produced charge. After fitting the plot of the centroid peak position versus voltage with the Hecht equation for single-polarity charge transport, the obtained hole mobility-lifetime product was in the range of (0.4–1.6)×10{sup −3} cm{sup 2}/V.

  8. Detection of charged particles with a methylammonium lead tribromide perovskite single crystal

    International Nuclear Information System (INIS)

    Xu, Qiang; Wei, Haotong; Wei, Wei; Chuirazzi, William; DeSantis, Dylan; Huang, Jinsong; Cao, Lei

    2017-01-01

    Methylammonium lead tribromide (MAPbBr_3) perovskite crystals have attracted significant attention due to their attractive performance in various optoelectronic applications such as solar cells, light-emitting devices, photodetectors, and recently in X-ray detectors. In this study, we demonstrate a possible use of perovskite-based devices for detection of charged particles (which can be applied in basic scientific research, health physics, and environmental analysis) and investigate the mechanism of fundamental charge transport inside perovskite crystals. It was found that inexpensive MAPbBr_3 single crystals could be used for measuring the energy spectrum of charged particles through direct collection of the produced charge. After fitting the plot of the centroid peak position versus voltage with the Hecht equation for single-polarity charge transport, the obtained hole mobility-lifetime product was in the range of (0.4–1.6)×10"−"3 cm"2/V.

  9. Mobility and height detection of particle labels in an optical evanescent wave biosensor with single-label resolution

    NARCIS (Netherlands)

    van Ommering, K.; Somers, P.A.; Koets, M.; Schleipen, J.J.H.B.; IJzendoorn, van L.J.; Prins, M.W.J.

    2010-01-01

    Particle labels are used in biosensors to detect the presence and concentration of analyte molecules. In this paper we demonstrate an optical technique to measure the mobility and height of bound particle labels on a biosensor surface with single-label resolution. The technique is based on the

  10. Detection of lead nanoparticles in game meat by single particle ICP-MS following use of lead-containing bullets

    DEFF Research Database (Denmark)

    Kollander, Barbro; Widemo, Fredrik; Ågren, Erik

    2017-01-01

    This study investigated whether game meat may contain nanoparticles of lead from ammunition. Lead nanoparticles in the range 40 to 750 nm were detected by ICP-MS in single particle mode in game shot with lead-containing bullets. The median diameter of the detected nanoparticles was around 60 nm....... The particle mass concentration ranged from 290 to 340 ng/g meat and the particle number concentrations from 27 to 50 million particles/g meat. The size limit of detection strongly depended on the level of dissolved lead and was in the range of 40 to 80 nm. In game meat sampled more than 10 cm away from...... the wound channel, no lead particles with a diameter larger than 40 nm were detected. In addition to dissolved lead in meat that originated from particulates, the presence of lead nano particles in game meat represents a hitherto unattended source of lead with a largely unknown toxicological impact...

  11. Single-particle measurements of bouncing particles and in situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light-scattering detection

    Science.gov (United States)

    Liao, Jin; Brock, Charles A.; Murphy, Daniel M.; Sueper, Donna T.; Welti, André; Middlebrook, Ann M.

    2017-10-01

    A light-scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-AMS) to investigate collection efficiency (CE) while obtaining nonrefractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles scatter light from an internal laser beam and trigger saving individual particle mass spectra. Nearly all of the single-particle data with mass spectra that were triggered by scattered light signals were from particles larger than ˜ 280 nm in vacuum aerodynamic diameter. Over 33 000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the time and intensity of their total mass spectral signals. The particle mass from single-particle spectra is proportional to that derived from the light-scattering diameter (dva-LS) but not to that from the particle time-of-flight (PToF) diameter (dva-MS) from the time of the maximum mass spectral signal. The total mass spectral signal from delayed particles was about 80 % of that from prompt ones for the same dva-LS. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced off the vaporizer and vaporized later on another surface within the confines of the ionization source. Because delayed particles are detected by the mass spectrometer later than expected from their dva-LS size, they can affect the interpretation of particle size (PToF) mass distributions, especially at larger sizes. The CE, measured by the average number or mass fractions of particles optically detected that had measurable mass spectra, varied significantly (0.2-0.9) in different air masses. The measured CE agreed well with a previous parameterization when CE > 0.5 for acidic particles but was sometimes lower than the minimum parameterized CE of 0.5.

  12. Single particle tracking and single molecule energy transfer

    CERN Document Server

    Bräuchle, Christoph; Michaelis, Jens

    2009-01-01

    Closing a gap in the literature, this handbook gathers all the information on single particle tracking and single molecule energy transfer. It covers all aspects of this hot and modern topic, from detecting virus entry to membrane diffusion, and from protein folding using spFRET to coupled dye systems, as well recent achievements in the field. Throughout, the first-class editors and top international authors present content of the highest quality, making this a must-have for physical chemists, spectroscopists, molecular physicists and biochemists.

  13. On-Chip Magnetic Platform for Single-Particle Manipulation with Integrated Electrical Feedback.

    Science.gov (United States)

    Monticelli, Marco; Torti, Andrea; Cantoni, Matteo; Petti, Daniela; Albisetti, Edoardo; Manzin, Alessandra; Guerriero, Erica; Sordan, Roman; Gervasoni, Giacomo; Carminati, Marco; Ferrari, Giorgio; Sampietro, Marco; Bertacco, Riccardo

    2016-02-17

    Methods for the manipulation of single magnetic particles have become very interesting, in particular for in vitro biological studies. Most of these studies require an external microscope to provide the operator with feedback for controlling the particle motion, thus preventing the use of magnetic particles in high-throughput experiments. In this paper, a simple and compact system with integrated electrical feedback is presented, implementing in the very same device both the manipulation and detection of the transit of single particles. The proposed platform is based on zig-zag shaped magnetic nanostructures, where transverse magnetic domain walls are pinned at the corners and attract magnetic particles in suspension. By applying suitable external magnetic fields, the domain walls move to the nearest corner, thus causing the step by step displacement of the particles along the nanostructure. The very same structure is also employed for detecting the bead transit. Indeed, the presence of the magnetic particle in suspension over the domain wall affects the depinning field required for its displacement. This characteristic field can be monitored through anisotropic magnetoresistance measurements, thus implementing an integrated electrical feedback of the bead transit. In particular, the individual manipulation and detection of single 1-μm sized beads is demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Development of detection techniques for a single-particle of fissile material(II)

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y.; Kwack, E. H

    2001-06-01

    The Analytical methods and detection limit of signatures, and the particle discrimination techniques of unknown particles by microscope were investigated in this technical report. In connection with pre-treatment of swipe samples, sampling and treatment of particles, etching method, fission track observation and the preparation of sample for the neutron activation analysis were also described in this thchnical report.

  15. Development of detection techniques for a single-particle of fissile material(II)

    International Nuclear Information System (INIS)

    Sohn, S. C.; Kim, W. H.; Park, Y. J.; Song, B. C.; Jeon, Y. S.; Jee, K. Y.; Pyo, H. Y.; Kwack, E. H.

    2001-06-01

    The Analytical methods and detection limit of signatures, and the particle discrimination techniques of unknown particles by microscope were investigated in this technical report. In connection with pre-treatment of swipe samples, sampling and treatment of particles, etching method, fission track observation and the preparation of sample for the neutron activation analysis were also described in this thchnical report

  16. Fluorescent detection of single tracks of alpha particles using lithium fluoride crystals

    International Nuclear Information System (INIS)

    Bilski, P.; Marczewska, B.

    2017-01-01

    Lithium fluoride single crystals were successfully used for fluorescent imaging of single tracks of alpha particles. This was realized with a standard wide-field fluorescent microscope equipped with a 100× objective. Alpha particles create F_2 and F_3"+ color centers in LiF crystals. The subsequent illumination with the blue light (wavelength around 445 nm), excites these centers and produces fluorescence with a broad band peaked at 670 nm. The observed tracks of alpha particles have diameter of about 500 nm. Focusing of the microscope at different depths in a LiF crystal, enables imaging changes of shape and position of tracks, allowing for visualization of their paths. These encouraging results are the first step towards practical application of LiF as fluorescent nuclear track detectors.

  17. Single-particle characterization of the high-Arctic summertime aerosol

    Directory of Open Access Journals (Sweden)

    B. Sierau

    2014-07-01

    Full Text Available Single-particle mass-spectrometric measurements were carried out in the high Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS. The instrument deployed was an aerosol time-of-flight mass spectrometer (ATOFMS that provides information on the chemical composition of individual particles and their mixing state in real time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 and 3000 nm in diameter showed mass-spectrometric patterns, indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the high Arctic. To assess the importance of long-range particle sources for aerosol–cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest the presence of a particle type of

  18. Single-particle characterization of the high-Arctic summertime aerosol

    Science.gov (United States)

    Sierau, B.; Chang, R. Y.-W.; Leck, C.; Paatero, J.; Lohmann, U.

    2014-07-01

    Single-particle mass-spectrometric measurements were carried out in the high Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument deployed was an aerosol time-of-flight mass spectrometer (ATOFMS) that provides information on the chemical composition of individual particles and their mixing state in real time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 and 3000 nm in diameter showed mass-spectrometric patterns, indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the high Arctic. To assess the importance of long-range particle sources for aerosol-cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest the presence of a particle type of unknown composition

  19. Single-particle characterization of the High Arctic summertime aerosol

    Science.gov (United States)

    Sierau, B.; Chang, R. Y.-W.; Leck, C.; Paatero, J.; Lohmann, U.

    2014-01-01

    Single-particle mass spectrometric measurements were carried out in the High Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument deployed was an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) that provides information on the chemical composition of individual particles and their mixing state in real-time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 nm to 3000 nm in diameter showed mass spectrometric patterns indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the High Arctic. To assess the importance of long-range particle sources for aerosol-cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a~minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest a presence of a particle type of unknown composition

  20. Development and characterization of a single particle laser ablation mass spectrometer (SPLAM for organic aerosol studies

    Directory of Open Access Journals (Sweden)

    F. Gaie-Levrel

    2012-01-01

    Full Text Available A single particle instrument was developed for real-time analysis of organic aerosol. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM, samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized by using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL, sodium chloride (NaCl and dioctylphtalate (DOP particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL and detection efficiency (DE were determined using size-selected DOP particles. The DE ranges from 0.1 to 90% for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. During optical detection, particle scattered light from the two diode lasers, is detected by two photomultipliers and the detected signals are used to trigger UV excimer laser (λ = 248 nm used for one-step laser desorption ionization (LDI of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 × 10−15 kg (∼4 × 103 molecules. DOP particles were also used to test the overall operation of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first application of the instrument. Single particle mass spectra were obtained with an effective hit rate of 8%. Some of these mass spectra were found to be very different from one particle to another possibly reflecting chemical differences within the investigated indene SOA particles. Our study shows that an exhaustive statistical analysis, over hundreds of particles

  1. Single particle dynamics

    International Nuclear Information System (INIS)

    Siemens, P.J.; Jensen, A.S.

    1985-01-01

    It is shown that the opening of the 3-quasiparticle continuum at 3Δ sets the energy scale for the enhancement of the effective mass near the Fermi surface of nuclei. The authors argue that the spreading width of single-particle states due to coupling with low-lying collective modes is qualitatively different from the two-body collision mechanism, and contributes little to the single-particle lifetime in the sense of the optical model. (orig.)

  2. Electronic properties of single crystal CVD diamond and its suitability for particle detection in hadron physics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pomorski, Michal

    2008-08-07

    This work presents the study on the suitability of single-crystal CVD diamond for particle-detection systems in present and future hadron physics experiments. Different characterization methods of the electrical and the structural properties were applied to gain a deeper understanding of the crystal quality and the charge transport properties of this novel semiconductor material. First measurements regarding the radiation tolerance of diamond were performed with sensors heavily irradiated with protons and neutrons. Finally, detector prototypes were fabricated and successfully tested in various experiments as time detectors for minimum ionizing particles as well as for spectroscopy of heavy ions at the energy ranges available at the SIS and the UNILAC facilities of GSI. (orig.)

  3. Electronic properties of single crystal CVD diamond and its suitability for particle detection in hadron physics experiments

    International Nuclear Information System (INIS)

    Pomorski, Michal

    2008-01-01

    This work presents the study on the suitability of single-crystal CVD diamond for particle-detection systems in present and future hadron physics experiments. Different characterization methods of the electrical and the structural properties were applied to gain a deeper understanding of the crystal quality and the charge transport properties of this novel semiconductor material. First measurements regarding the radiation tolerance of diamond were performed with sensors heavily irradiated with protons and neutrons. Finally, detector prototypes were fabricated and successfully tested in various experiments as time detectors for minimum ionizing particles as well as for spectroscopy of heavy ions at the energy ranges available at the SIS and the UNILAC facilities of GSI. (orig.)

  4. Damping of unbound single-particle modes

    International Nuclear Information System (INIS)

    Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.

    1995-07-01

    The (α, 3 He-n) reaction has been investigated at 120 MeV incident energy on 64 Ni, 90 Zr and 120 Sn target nuclei. Neutrons in coincidence with 3 He particles emitted at 0 deg were detected, in order to get information about the decay of single-particle states embedded in the (α, 3 He) continuum. Neutron angular correlations, multiplicity values and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Direct branching ratios in 91 Zr deduced from this analysis are compared with the predictions of two nuclear structure models. (author)

  5. Multi-Color Single Particle Tracking with Quantum Dots

    DEFF Research Database (Denmark)

    Christensen, Eva Arnspang; Brewer, J. R.; Lagerholm, B. C.

    2012-01-01

    . multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations......Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g...... further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image...

  6. Single Particle Entropy in Heated Nuclei

    International Nuclear Information System (INIS)

    Guttormsen, M.; Chankova, R.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Syed, N. U. H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

    2006-01-01

    The thermal motion of single particles represents the largest contribution to level density (or entropy) in atomic nuclei. The concept of single particle entropy is presented and shown to be an approximate extensive (additive) quantity for mid-shell nuclei. A few applications of single particle entropy are demonstrated

  7. Charged-particle spectroscopy in organic semiconducting single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ciavatti, A.; Basiricò, L.; Fraboni, B. [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy); Sellin, P. J. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Fraleoni-Morgera, A. [ELETTRA-Sincrotrone Trieste, Strada Statale 14, Km 163.5, Basovizza, Trieste (Italy); Department of Engineering and Architecture, University of Trieste, V. Valerio 10, 34100 Trieste (Italy); CNR-Nano S3 Institute, Via Campi 213/A, 41125 Modena (Italy)

    2016-04-11

    The use of organic materials as radiation detectors has grown, due to the easy processability in liquid phase at room temperature and the possibility to cover large areas by means of low cost deposition techniques. Direct charged-particle detectors based on solution-grown Organic Semiconducting Single Crystals (OSSCs) are shown to be capable to detect charged particles in pulse mode, with very good peak discrimination. The direct charged-particle detection in OSSCs has been assessed both in the planar and in the vertical axes, and a digital pulse processing algorithm has been used to perform pulse height spectroscopy and to study the charge collection efficiency as a function of the applied bias voltage. Taking advantage of the charge spectroscopy and the good peak discrimination of pulse height spectra, an Hecht-like behavior of OSSCs radiation detectors is demonstrated. It has been possible to estimate the mobility-lifetime value in organic materials, a fundamental parameter for the characterization of radiation detectors, whose results are equal to μτ{sub coplanar} = (5 .5 ± 0.6 ) × 10{sup −6} cm{sup 2}/V and μτ{sub sandwich} = (1 .9 ± 0.2 ) × 10{sup −6} cm{sup 2}/V, values comparable to those of polycrystalline inorganic detectors. Moreover, alpha particles Time-of-Flight experiments have been carried out to estimate the drift mobility value. The results reported here indicate how charged-particle detectors based on OSSCs possess a great potential as low-cost, large area, solid-state direct detectors operating at room temperature. More interestingly, the good detection efficiency and peak discrimination observed for charged-particle detection in organic materials (hydrogen-rich molecules) are encouraging for their further exploitation in the detection of thermal and high-energy neutrons.

  8. F F1-ATPase as biosensor to detect single virus

    International Nuclear Information System (INIS)

    Liu, XiaoLong; Zhang, Yun; Yue, JiaChang; Jiang, PeiDong; Zhang, ZhenXi

    2006-01-01

    F F 1 -ATPase within chromatophore was constructed as a biosensor (immuno-rotary biosensor) for the purpose of capturing single virus. Capture of virus was based on antibody-antigen reaction. The detection of virus based on proton flux change driven by ATP-synthesis of F F 1 -ATPase, which was indicated by F1300, was directly observed by a fluorescence microscope. The results demonstrate that the biosensor loading of virus particles has remarkable signal-to-noise ratio (3.8:1) compared to its control at single molecular level, and will be convenient, quick, and even super-sensitive for detecting virus particles

  9. 3D Silicon Coincidence Avalanche Detector (3D-SiCAD) for charged particle detection

    Science.gov (United States)

    Vignetti, M. M.; Calmon, F.; Pittet, P.; Pares, G.; Cellier, R.; Quiquerez, L.; Chaves de Albuquerque, T.; Bechetoille, E.; Testa, E.; Lopez, J.-P.; Dauvergne, D.; Savoy-Navarro, A.

    2018-02-01

    Single-Photon Avalanche Diodes (SPADs) are p-n junctions operated in Geiger Mode by applying a reverse bias above the breakdown voltage. SPADs have the advantage of featuring single photon sensitivity with timing resolution in the picoseconds range. Nevertheless, their relatively high Dark Count Rate (DCR) is a major issue for charged particle detection, especially when it is much higher than the incoming particle rate. To tackle this issue, we have developed a 3D Silicon Coincidence Avalanche Detector (3D-SiCAD). This novel device implements two vertically aligned SPADs featuring on-chip electronics for the detection of coincident avalanche events occurring on both SPADs. Such a coincidence detection mode allows an efficient discrimination of events related to an incoming charged particle (producing a quasi-simultaneous activation of both SPADs) from dark counts occurring independently on each SPAD. A 3D-SiCAD detector prototype has been fabricated in CMOS technology adopting a 3D flip-chip integration technique, and the main results of its characterization are reported in this work. The particle detection efficiency and noise rejection capability for this novel device have been evaluated by means of a β- strontium-90 radioactive source. Moreover the impact of the main operating parameters (i.e. the hold-off time, the coincidence window duration, the SPAD excess bias voltage) over the particle detection efficiency has been studied. Measurements have been performed with different β- particles rates and show that a 3D-SiCAD device outperforms single SPAD detectors: the former is indeed capable to detect particle rates much lower than the individual DCR observed in a single SPAD-based detectors (i.e. 2 to 3 orders of magnitudes lower).

  10. Particle detection

    International Nuclear Information System (INIS)

    Charpak, G.

    2000-01-01

    In this article G.Charpak presents the principles on which particle detection is based. Particle accelerators are becoming more and more powerful and require new detectors able to track the right particle in a huge flux of particles. The gigantic size of detectors in high energy physics is often due to the necessity of getting a long enough trajectory in a magnetic field in order to deduce from the curvature an accurate account of impulses in the reaction. (A.C.)

  11. Single particle detection: Phase control in submicron Hall sensors

    International Nuclear Information System (INIS)

    Di Michele, Lorenzo; Shelly, Connor; Gallop, John; Kazakova, Olga

    2010-01-01

    We present a phase-sensitive ac-dc Hall magnetometry method which allows a clear and reliable separation of real and parasitic magnetic signals of a very small magnitude. High-sensitivity semiconductor-based Hall crosses are generally accepted as a preferential solution for non-invasive detection of superparamagnetic nanobeads used in molecular biology, nanomedicine, and nanochemistry. However, detection of such small beads is often hindered by inductive pick-up and other spurious signals. The present work demonstrates an unambiguous experimental route for detection of small magnetic moments and provides a simple theoretical background for it. The reliability of the method has been tested for a variety of InSb Hall sensors in the range 600 nm-5 μm. Complete characterization of empty devices, involving Hall coefficients and noise measurements, has been performed and detection of a single FePt bead with diameter of 140 nm and magnetic moment of μ≅10 8 μ B has been achieved with a 600 nm-wide sensor.

  12. Single-Particle States in $^{133}$Sn

    CERN Multimedia

    Huck, A

    2002-01-01

    % IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.

  13. Delivery of single accelerated particles

    International Nuclear Information System (INIS)

    McNulty, P.J.; Pease, V.P.; Bond, V.P.; Schimmerling, W.; Vosburgh, K.G.; Crebbin, K.; Everette, W.; Howard, J.

    1978-01-01

    It is desirable for certain experiments involving accelerators to have the capability of delivering just a single beam particle to the target area. The essential features of such a one-at-a-time facility are discussed. Two such facilities are described which were implemented at high-energy heavy ion accelerators without having to make major structural changes in the existing beam lines or substantially interfering with other accelerator uses. Two accelerator facilities are described which had the capability of delivering a single beam particle to the target area. This feature is necessary in certain experiments investigating visual phenomena induced by charged particles, other single particle interactions in biology, and other experiments in which the low intensities of cosmic rays need to be simulated. Both facilities were implemented without having to make structural changes in the existing beam lines or substantially interfering with other accelerator uses. (Auth.)

  14. Exploiting evanescent-wave amplification for subwavelength low-contrast particle detection

    Science.gov (United States)

    Roy, S.; Pereira, S. F.; Urbach, H. P.; Wei, Xukang; El Gawhary, O.

    2017-07-01

    The classical problem of subwavelength particle detection on a flat surface is especially challenging when the refractive index of the particle is close to that of the substrate. We demonstrate a method to improve the detection ability several times for such a situation, by enhancing the "forbidden" evanescent waves in the substrate using the principle of super-resolution with evanescent waves amplification. The working mechanism of the system and experimental validation from a design with a thin single dielectric layer is presented. The resulting system is a simple but complete example of evanescent-wave generation, amplification, and the consequent modulation of the far field. This principle can have far reaching impact in the field of particle detection in several applications ranging from contamination control to interferometric scattering microscopy for biological samples.

  15. Detection of minimum-ionizing particles in hydrogenated amorphous silicon

    International Nuclear Information System (INIS)

    Kaplan, S.N.; Fujieda, I.; Perez-Mendez, V.; Qureshi, S.; Ward, W.; Street, R.A.

    1987-09-01

    Based on previously-reported results of the successful detection of alpha particles and 1- and 2-MeV protons with hydrogenated amorphous silicon (a-Si : H) diodes, detection of a single minimum-ionizing particle will require a total sensitive thickness of approximately 100 to 150 μm, either in the form of a single thick diode, or as a stack of several thinner diodes. Signal saturation at high dE/dx makes it necessary to simulate minimum ionization in order to evaluate present detectors. Two techniques, using pulsed infrared light, and pulsed x-rays, give single-pulse signals large enough for direct measurements. A third, using beta rays, requires multiple-transit signal averaging to produce signals measurable above noise. Signal amplitudes from the a-Si : H limit at 60% of the signal size from Si crystals extrapolated to the same thickness. This is consistent with an a-Si : H radiation ionization energy, W = 6 eV/electron-hole pair. Beta-ray signals are observed at the expected amplitude

  16. Preliminary Understanding of Surface Plasmon-Enhanced Circular Dichroism Spectroscopy by Single Particle Imaging

    Science.gov (United States)

    Zhan, Kangshu

    Monitoring chiral optical signals of biomolecules as their conformation changes is an important means to study their structures, properties, and functions. Most measurements, however, are ensemble measurements because chiral optical signals from a single biomolecule is often too weak to be detected. In this dissertation, I present my early attempts to study conformational changes of adsorbed proteins by taking advantage of the enhanced electromagnetic (EM) field around a well-designed plasmonic nanofeature. In particular, I discuss the detection of protein adsorption and denaturation on metallic nanoparticles using single particle scattering and CD spectroscopic imaging. Particles of two distinctively different sizes were compared and two different sample protein molecules were studied. A combination of experimental and computational tools was used to simulate and interpret the collected scattering and CD results. The first chapter provides a brief overview of the state-of-art research in CD spectroscopic studies at the single particle level. Three different means to make particles capable of chiral detection are discussed. Various applications beyond single particle imaging are presented to showcase the potential of the described research project, beyond our immediate goals. The second chapter describes my initial characterization of large, metallic, anisotropic nanorods and the establishment of experimental procedures used later for spectrum reconstruction, data visualization and analysis. The physical shape and structure of the particles were imaged by scanning electron microscopy (SEM), the chemical composition by energy dispersive X-ray Spectroscopy (EDS), and the optical properties by darkfield microscopy. An experimental protocol was developed to connect information collected from separate techniques for the same particle, with the aims of discovering any possible structural-property correlation. The reproducibility of the single particle imaging method was

  17. Single-particle dispersion in compressible turbulence

    Science.gov (United States)

    Zhang, Qingqing; Xiao, Zuoli

    2018-04-01

    Single-particle dispersion statistics in compressible box turbulence are studied using direct numerical simulation. Focus is placed on the detailed discussion of effects of the particle Stokes number and turbulent Mach number, as well as the forcing type. When solenoidal forcing is adopted, it is found that the single-particle dispersion undergoes a transition from the ballistic regime at short times to the diffusive regime at long times, in agreement with Taylor's particle dispersion argument. The strongest dispersion of heavy particles is announced when the Stokes number is of order 1, which is similar to the scenario in incompressible turbulence. The dispersion tends to be suppressed as the Mach number increases. When hybrid solenoidal and compressive forcing at a ratio of 1/2 is employed, the flow field shows apparent anisotropic property, characterized by the appearance of large shock wave structures. Accordingly, the single-particle dispersion shows extremely different behavior from the solenoidal forcing case.

  18. Single-particle potential from resummed ladder diagrams

    International Nuclear Information System (INIS)

    Kaiser, N.

    2013-01-01

    A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by calculating the complex single-particle potential U(p, k f ) + i W(p, k f ) p > k f . The on-shell single-particle potential is constructed by means of a complex-valued in-medium loop that includes corrections from a test particle of momentum vector p added to the filled Fermi sea. The single-particle potential U(k f , k f ) at the Fermi surface as obtained from the resummation of the combined particle and hole ladder diagrams is shown to satisfy the Hugenholtz-Van-Hove theorem. The perturbative contributions at various orders a n in the scattering length are deduced and checked against the known analytical results at order a 1 and a 2 . The limit a → ∞ is studied as a special case and a strong momentum dependence of the real (and imaginary) single-particle potential is found. This feature indicates an instability against a phase transition to a state with an empty shell inside the Fermi sphere such that the density gets reduced by about 5%. The imaginary single-particle potential vanishes linearly at the Fermi surface. For comparison, the same analysis is performed for the resummed particle-particle ladder diagrams alone. In this truncation an instability for hole excitations near the Fermi surface is found at strong coupling. For the set of particle-hole ring diagrams the single-particle potential is calculated as well. Furthermore, the resummation of in-medium ladder diagrams to all orders is studied for a two-dimensional Fermi gas with a short-range two-body contact interaction. (orig.)

  19. Single particle distributions, ch.2

    International Nuclear Information System (INIS)

    Blokzijl, R.

    1977-01-01

    A survey of inclusive single particle distributions is given for various particles. A comparison of particle cross-sections measured in K - p experiments at different center of mass energies shows that some of these cross-sections remain almost constant over a wide range of incoming K - momenta

  20. Morphology of single inhalable particle inside public transit biodiesel fueled bus.

    Science.gov (United States)

    Shandilya, Kaushik K; Kumar, Ashok

    2010-01-01

    In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry (SEM/EDS). Particle size analysis found bimodal distribution at 0.2 and 0.5 microm. The particle morphology was characterized by 14 different shape clusters: square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick, and unknown, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or sticks are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.

  1. Damping of unbound single-particle modes

    International Nuclear Information System (INIS)

    Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A.

    1995-01-01

    The (α, 3 He-n) reaction has been investigated at 120 MeV incident energy on 64 Ni, 90 Zr, and 120 Sn target nuclei. Neutrons in coincidence with 3 He particles emitted at 0 degree were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the (α, 3 He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in 91 Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the (α, 3 He) continuum are shown to be mainly statistical

  2. Detection of Diffusion Heterogeneity in Single Particle Tracking Trajectories Using a Hidden Markov Model with Measurement Noise Propagation

    Science.gov (United States)

    Slator, Paddy J.; Cairo, Christopher W.; Burroughs, Nigel J.

    2015-01-01

    We develop a Bayesian analysis framework to detect heterogeneity in the diffusive behaviour of single particle trajectories on cells, implementing model selection to classify trajectories as either consistent with Brownian motion or with a two-state (diffusion coefficient) switching model. The incorporation of localisation accuracy is essential, as otherwise false detection of switching within a trajectory was observed and diffusion coefficient estimates were inflated. Since our analysis is on a single trajectory basis, we are able to examine heterogeneity between trajectories in a quantitative manner. Applying our method to the lymphocyte function-associated antigen 1 (LFA-1) receptor tagged with latex beads (4 s trajectories at 1000 frames s−1), both intra- and inter-trajectory heterogeneity were detected; 12–26% of trajectories display clear switching between diffusive states dependent on condition, whilst the inter-trajectory variability is highly structured with the diffusion coefficients being related by D 1 = 0.68D 0 − 1.5 × 104 nm2 s−1, suggestive that on these time scales we are detecting switching due to a single process. Further, the inter-trajectory variability of the diffusion coefficient estimates (1.6 × 102 − 2.6 × 105 nm2 s−1) is very much larger than the measurement uncertainty within trajectories, suggesting that LFA-1 aggregation and cytoskeletal interactions are significantly affecting mobility, whilst the timescales of these processes are distinctly different giving rise to inter- and intra-trajectory variability. There is also an ‘immobile’ state (defined as D models within membranes incorporating aggregation, binding to the cytoskeleton, or traversing membrane microdomains. PMID:26473352

  3. Single-particle electron microscopy in the study of membrane protein structure.

    Science.gov (United States)

    De Zorzi, Rita; Mi, Wei; Liao, Maofu; Walz, Thomas

    2016-02-01

    Single-particle electron microscopy (EM) provides the great advantage that protein structure can be studied without the need to grow crystals. However, due to technical limitations, this approach played only a minor role in the study of membrane protein structure. This situation has recently changed dramatically with the introduction of direct electron detection device cameras, which allow images of unprecedented quality to be recorded, also making software algorithms, such as three-dimensional classification and structure refinement, much more powerful. The enhanced potential of single-particle EM was impressively demonstrated by delivering the first long-sought atomic model of a member of the biomedically important transient receptor potential channel family. Structures of several more membrane proteins followed in short order. This review recounts the history of single-particle EM in the study of membrane proteins, describes the technical advances that now allow this approach to generate atomic models of membrane proteins and provides a brief overview of some of the membrane protein structures that have been studied by single-particle EM to date. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. A broad-application microchannel-plate detector system for advanced particle or photon detection tasks large area imaging, precise multi-hit timing information and high detection rate

    CERN Document Server

    Jagutzki, O; Mergel, V; Schmidt-Böcking, H; Spielberger, L; Spillmann, U; Ullmann-Pfleger, K

    2002-01-01

    New applications for single particle and photon detection in many fields require both large area imaging performance and precise time information on each detected particle. Moreover, a very high data acquisition rate is desirable for most applications and eventually the detection and imaging of more than one particle arriving within a microsecond is required. Commercial CCD systems lack the timing information whereas other electronic microchannel plate (MCP) read-out schemes usually suffer from a low acquisition rate and complicated and sometimes costly read-out electronics. We have designed and tested a complete imaging system consisting of an MCP position readout with helical wire delay-lines, single-unit amplifier box and PC-controlled time-to-digital converter (TDC) readout. The system is very flexible and can detect and analyse position and timing information at single particle rates beyond 1 MHz. Alternatively, multi-hit events can be collected and analysed at about 20 kHz rate. We discuss the advantage...

  5. Damping of unbound single-particle modes

    Energy Technology Data Exchange (ETDEWEB)

    Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A. [Institut de Physique Nucleaire, IN2P3-CNRS, 91406 Orsay Cedex (France)]|[Kernfysisch Versneller Instituut, 9747 AA Groningen (Netherlands)]|[Nuclear Research Institute, Debrecen P.O. Box 51, H-4001 (Hungary)]|[NSCL, Michigan State University, East Lansing, Michigan 48824 (United States)]|[Dep. Fisica, Fac. Cs. Exactas, UNLP, CC Nio 67, 1900 La Plata (Argentina)]|[Institut de Sciences Exactes,Universite de Tizi-Ouzou, 15000 Tizi-Ouzou (Algeria)

    1995-11-01

    The ({alpha},{sup 3}He-{ital n}) reaction has been investigated at 120 MeV incident energy on {sup 64}Ni, {sup 90}Zr, and {sup 120}Sn target nuclei. Neutrons in coincidence with {sup 3}He particles emitted at 0{degree} were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the ({alpha},{sup 3}He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in {sup 91}Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the ({alpha},{sup 3}He) continuum are shown to be mainly statistical.

  6. Particle detection systems and methods

    Science.gov (United States)

    Morris, Christopher L.; Makela, Mark F.

    2010-05-11

    Techniques, apparatus and systems for detecting particles such as muons and neutrons. In one implementation, a particle detection system employs a plurality of drift cells, which can be for example sealed gas-filled drift tubes, arranged on sides of a volume to be scanned to track incoming and outgoing charged particles, such as cosmic ray-produced muons. The drift cells can include a neutron sensitive medium to enable concurrent counting of neutrons. The system can selectively detect devices or materials, such as iron, lead, gold, uranium, plutonium, and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can concurrently detect any unshielded neutron sources occupying the volume from neutrons emitted therefrom. If necessary, the drift cells can be used to also detect gamma rays. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

  7. Single Molecule Raman Detection of Enkephalin on Silver Colloidal Particles

    DEFF Research Database (Denmark)

    Kneipp, Katrin; Kneipp, Holger; Abdali, Salim

    2004-01-01

    the Raman signal the enkephalin molecules have been attached to silver colloidal cluster structures. The experiments demonstrate that the SERS signal of the strongly enhanced ring breathing vibration of phenylalanine at 1000 cm-1 can be used as “intrinsic marker” for detecting a single enkephalin molecule...... and for monitoring its diffusion on the surface of the silver colloidal cluster without using a specific label molecule....

  8. Saha equation, single and two particle states

    International Nuclear Information System (INIS)

    Kraeft, W.D.; Girardeau, M.D.; Strege, B.

    1990-01-01

    Single and two particle porperties in dense plasma are discussed in connection with their role in the mass action law for a partially ionized plasma. The two particle bound states are nearly density independent, while the continuum is essentially shifted. The single particle states are damped, and their energy has a negative shift and a parabolic behaviour for small momenta. (orig.)

  9. Chemical characterization of freshly emitted particulate matter from aircraft exhaust using single particle mass spectrometry

    Science.gov (United States)

    Abegglen, Manuel; Brem, B. T.; Ellenrieder, M.; Durdina, L.; Rindlisbacher, T.; Wang, J.; Lohmann, U.; Sierau, B.

    2016-06-01

    Non-volatile aircraft engine emissions are an important anthropogenic source of soot particles in the upper troposphere and in the vicinity of airports. They influence climate and contribute to global warming. In addition, they impact air quality and thus human health and the environment. The chemical composition of non-volatile particulate matter emission from aircraft engines was investigated using single particle time-of-flight mass spectrometry. The exhaust from three different aircraft engines was sampled and analyzed. The soot particulate matter was sampled directly behind the turbine in a test cell at Zurich Airport. Single particle analyses will focus on metallic compounds. The particles analyzed herein represent a subset of the emissions composed of the largest particles with a mobility diameter >100 nm due to instrumental restrictions. A vast majority of the analyzed particles was shown to contain elemental carbon, and depending on the engine and the applied thrust the elemental carbon to total carbon ratio ranged from 83% to 99%. The detected metallic compounds were all internally mixed with the soot particles. The most abundant metals in the exhaust were Cr, Fe, Mo, Na, Ca and Al; V, Ba, Co, Cu, Ni, Pb, Mg, Mn, Si, Ti and Zr were also detected. We further investigated potential sources of the ATOFMS-detected metallic compounds using Inductively Coupled Plasma Mass Spectrometry. The potential sources considered were kerosene, engine lubrication oil and abrasion from engine wearing components. An unambiguous source apportionment was not possible because most metallic compounds were detected in several of the analyzed sources.

  10. Single-particle Glauber matrix elements

    International Nuclear Information System (INIS)

    Oset, E.; Strottman, D.

    1983-01-01

    The single-particle matrix elements of the Glauber profile function are tabulated for harmonic oscillator single-particle wave functions. The tables are presented in such a manner as to be applicable if the hadron--nucleon elementary scattering amplitude is specified by either a partial wave expansion or a Gaussian in momentum transfer squared. The table is complete through the 1 g/sub 9/2/ orbital and contains entries for the 3s/sub 1/2/ orbital for use if realistic wave functions are expanded in terms of harmonic oscillator functions

  11. Experimental study of single-particle inclusive hadron scattering and associated multiplicities

    International Nuclear Information System (INIS)

    Brenner, A.E.; Carey, D.C.; Elias, J.E.; Garbincius, P.H.; Mikenberg, G.; Polychronakos, V.A.; Aitkenhead, W.; Barton, D.S.; Brandenburg, G.W.; Busza, W.; Dobrowolski, T.; Friedman, J.I.; Kendall, H.W.; Lyons, T.; Nelson, B.; Rosenson, L.; Toy, W.; Verdier, R.; Votta, L.; Chiaradia, M.T.; DeMarzo, C.; Favuzzi, C.; Germinario, G.; Guerriero, L.; LaVopa, P.; Maggi, G.; Posa, F.; Selvaggi, G.; Spinelli, P.; Waldner, F.; Meunier, R.; Cutts, D.; Dulude, R.S.; Lanou, R.E. Jr.; Massimo, J.T.

    1982-01-01

    An experiment using the Fermilab single arm spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied the reactions a+p→c+X where a and c were π +- , K +- , p, or p-bar. Extensive measurements were made at 100 and 175 GeV/c beam momenta with the outgoing hadrons detected in the SAS covering a kinematic range 0.12< x<1.0 and p/sub T/<1.25 GeV/c. Additional data covering a more restricted range in x were also gathered at 70 GeV/c incident momentum. In this high-statistics experiment, the identification of both the incoming and outgoing charged hadrons were made with a total of eight Cerenkov counters. New and extensive single-particle inclusive data for charged-particle production in low-p/sub T/ hadronic fragmentation are presented. The average associated charged-particle multiplicity and pseudorapidity distributions are also given

  12. Cantilever-based micro-particle filter with simultaneous single particle detection

    DEFF Research Database (Denmark)

    Noeth, Nadine-Nicole; Keller, Stephan Sylvest; Boisen, Anja

    2011-01-01

    Currently, separation of whole blood samples on lab-on-a-chip systems is achieved via filters followed by analysis of the filtered matter such as counting of blood cells. Here, a micro-chip based on cantilever technology is developed, which enables simultaneous filtration and counting of micro-particles...... from a liquid. A hole-array is integrated into a micro-cantilever, which is inserted into a microfluidic channel perpendicular to the flow. A metal pad at the apex of the cantilever enables an optical read-out of the deflection of the cantilever. When a micro-particle is too large to pass a hole...

  13. Transistor-based particle detection systems and methods

    Science.gov (United States)

    Jain, Ankit; Nair, Pradeep R.; Alam, Muhammad Ashraful

    2015-06-09

    Transistor-based particle detection systems and methods may be configured to detect charged and non-charged particles. Such systems may include a supporting structure contacting a gate of a transistor and separating the gate from a dielectric of the transistor, and the transistor may have a near pull-in bias and a sub-threshold region bias to facilitate particle detection. The transistor may be configured to change current flow through the transistor in response to a change in stiffness of the gate caused by securing of a particle to the gate, and the transistor-based particle detection system may configured to detect the non-charged particle at least from the change in current flow.

  14. Single-particle Schroedinger fluid. I. Formulation

    International Nuclear Information System (INIS)

    Kan, K.K.; Griffin, J.J.

    1976-01-01

    The problem of a single quantal particle moving in a time-dependent external potential well is formulated specifically to emphasize and develop the fluid dynamical aspects of the matter flow. This idealized problem, the single-particle Schroedinger fluid, is shown to exhibit already a remarkably rich variety of fluid dynamical features, including compressible flow and line vortices. It provides also a sufficient framework to encompass simultaneously various simplified fluidic models for nuclei which have earlier been postulated on an ad hoc basis, and to illuminate their underlying restrictions. Explicit solutions of the single-particle Schroedinger fluid problem are studied in the adiabatic limit for their mathematical and physical implications (especially regarding the collective kinetic energy). The basic generalizations for extension of the treatment to the many-body Schroedinger fluid are set forth

  15. Methods for forming particles from single source precursors

    Science.gov (United States)

    Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

    2011-08-23

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  16. Thermal pulse detection of photons and charged particles

    International Nuclear Information System (INIS)

    Riisager, K.; Hansen, P.G.

    1986-01-01

    During the last few years the technique of thermal detection has been developed so that high resolution spectroscopy of single particles is possible. This method seems to yield improvements in energy resolution of about a factor 100 and could thus be of decisive importance for neutrino experiments. The theoretical limits for the resolution and the experimental works performed to data are reviewed and the Goeteborg detector is briefly described. 18 refs

  17. Single-particle motion in large-amplitude quadrupole shape transition

    International Nuclear Information System (INIS)

    Yamada, Kazuya

    1991-01-01

    The microscopic structure of the single-particle motion for the spherical-deformed transitional nuclei is analysed by using the self-consistent collective-coordinate method (SCC method). The single-particle motion in the moving-frame of reference called the collective vibrating coordinate frame is introduced by the generalized Bogoliubov transformation depending on the collective coordinate. The numerical calculations of the single-particle (quasi-particle) energy level diagrams and their occupation probabilities for the static deformation are carried out for the Sm isotopes. A clear change of the single-particle distribution structure appears in the course of deformation. (author)

  18. Single particle dynamics in circular accelerators

    International Nuclear Information System (INIS)

    Ruth, R.D.

    1986-10-01

    The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

  19. Fundamental study of single biomass particle combustion

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M.

    2013-06-01

    This thesis is a comprehensive study of single biomass particle combustion. The effect of particle shape and size and operating conditions on biomass conversion characteristics were investigated experimentally and theoretically. The experimental samples were divided in two groups: particles with regular shapes (spheres and cylinders) and particles with irregular shapes (almost flake-like). A CAMSIZER analyser (Retsch Technology GMBH) was used to determine the size and shape of the particles via Dynamical Digital Image Processing. The experiments were performed in a single particle reactor under well-defined conditions, and the complete combustion processes were recorded as video sequences by a CCD camera installed in the set-up. One of the project objectives is to simulate conditions reasonably close to the conditions in a power plant boiler, i.e., reasonably high temperatures (up to 1600 deg. C) and varying oxygen concentrations in the 5 to 20% range. A one-dimensional mathematical model was used to simulate all the intraparticle conversion processes (drying, recondensation, devolatilisation, char gasification/oxidation and heat/mass/momentum transfer) within single particles of different shapes and size under various conditions. The model also predicts the flame layer domain of a single particle. The model was validated by experimental results under different conditions; good agreement between the model predictions and the experimental data was observed. Both the experimental and modelling results showed that cylindrical particles lose mass faster than spherical particles of a similar volume (mass) and that the burnout time is reduced by increasing the particle aspect ratio (surface area to volume ratio). Very similar conversion times were observed for cylindrical particles with nearly identical surface area to volume ratios. Similar conversion times were also observed for two size classes of pulverised particles (with irregular shapes) made from the same type of

  20. Distribution of lead in single atmospheric particles

    Science.gov (United States)

    Murphy, D. M.; Hudson, P. K.; Cziczo, D. J.; Gallavardin, S.; Froyd, K. D.; Johnston, M. V.; Middlebrook, A. M.; Reinard, M. S.; Thomson, D. S.; Thornberry, T.; Wexler, A. S.

    2007-06-01

    Three independent single particle mass spectrometers measured Pb in individual aerosol particles. These data provide unprecedented sensitivity and statistical significance for the measurement of Pb in single particles. This paper explores the reasons for the frequency of Pb in fine particles now that most gasoline is unleaded. Trace amounts of Pb were found in 5 to 25% of 250 to 3000 nm diameter particles sampled by both aircraft and surface instruments in the eastern and western United States. Over 5% of particles at a mountain site in Switzerland contained Pb. Particles smaller than 100 nm with high Pb content were also observed by an instrument that was only operated in urban areas. Lead was found on all types of particles, including Pb present on biomass burning particles from remote fires. Less common particles with high Pb contents contributed a majority of the total amount of Pb. Single particles with high Pb content often also contained alkali metals, Zn, Cu, Sn, As, and Sb. The association of Pb with Zn and other metals is also found in IMPROVE network filter data from surface sites. Sources of airborne Pb in the United States are reviewed for consistency with these data. The frequent appearance of trace Pb is consistent with widespread emissions of fine Pb particles from combustion sources followed by coagulation with larger particles during long-range transport. Industrial sources that directly emit Pb-rich particles also contribute to the observations. Clean regions of the western United States show some transport of Pb from Asia but most Pb over the United States comes from North American sources. Resuspension of Pb from soil contaminated by the years of leaded gasoline was not directly apparent.

  1. Distribution of lead in single atmospheric particles

    Directory of Open Access Journals (Sweden)

    D. M. Murphy

    2007-06-01

    Full Text Available Three independent single particle mass spectrometers measured Pb in individual aerosol particles. These data provide unprecedented sensitivity and statistical significance for the measurement of Pb in single particles. This paper explores the reasons for the frequency of Pb in fine particles now that most gasoline is unleaded. Trace amounts of Pb were found in 5 to 25% of 250 to 3000 nm diameter particles sampled by both aircraft and surface instruments in the eastern and western United States. Over 5% of particles at a mountain site in Switzerland contained Pb. Particles smaller than 100 nm with high Pb content were also observed by an instrument that was only operated in urban areas. Lead was found on all types of particles, including Pb present on biomass burning particles from remote fires. Less common particles with high Pb contents contributed a majority of the total amount of Pb. Single particles with high Pb content often also contained alkali metals, Zn, Cu, Sn, As, and Sb. The association of Pb with Zn and other metals is also found in IMPROVE network filter data from surface sites. Sources of airborne Pb in the United States are reviewed for consistency with these data. The frequent appearance of trace Pb is consistent with widespread emissions of fine Pb particles from combustion sources followed by coagulation with larger particles during long-range transport. Industrial sources that directly emit Pb-rich particles also contribute to the observations. Clean regions of the western United States show some transport of Pb from Asia but most Pb over the United States comes from North American sources. Resuspension of Pb from soil contaminated by the years of leaded gasoline was not directly apparent.

  2. Design of a confocal microfluidic particle sorter using fluorescent photon burst detection

    NARCIS (Netherlands)

    Kunst, B.H.; Schots, A.; Visser, A.J.W.G.

    2004-01-01

    An instrumental system is described for detecting and sorting single fluorescent particles such as microspheres, bacteria, viruses, or even smaller macromolecules in a flowing liquid. The system consists of microfluidic chips (biochips), computer controlled high voltage power supplies, and a

  3. Single particle measurements and two particle interferometry results from CERN experiment NA44

    International Nuclear Information System (INIS)

    Simon-Gillo, J.

    1994-01-01

    CERN experiment NA44 is optimized for the study of identified single and multiple particle distributions to p T = 0 near mid-rapidity. We measure π +- , K +- , p, bar p, d and bar d, in p + A and A + A collisions at 450 and 20OGeV/u, respectively. Two-particle intensity interferometry results from π + π + , K + K + , and K - K - measurements and single particle distributions are presented

  4. A radioactive particle detection system for the Maralinga rehabilitation project

    International Nuclear Information System (INIS)

    Martin, L.J.; Baylis, S.H.

    1998-01-01

    Following the cessation of British nuclear testing at Maralinga, several sites were left contaminated with plutonium in various forms over areas of many square kilometres. The contamination included 239 Pu and 241 Am together with other isotopes of plutonium, and was in the form of fine dust, discrete particles and contaminated fragments of metals, plastics and ceramics. Following a government decision to rehabilitate the area to a standard suitable for re-occupation by the traditional owners, the Maralinga Tjarutja, an expert committee, MARTAC, was convened to advise the Department of Primary Industries and Energy about suitable methods and standards for the cleanup. Criteria set by MARTAC required the removal of all discrete particles of contamination exceeding 100 kBq of 241 Am and imposed limits on the numbers of particles exceeding 20 kBq. A detection system was required which could detect any radioactive particles exceeding criteria and, following rehabilitation, verify that none remained. The most useful indicator of contamination was the 60 keV gamma-ray from 241 Am. The system was fitted to a four wheel drive utility vehicle, and was based on four thin-crystal, sodium iodide detectors of 12.5 cm diameter held 30 cm above ground level. Electronic components from off-the-shelf hand-held ratemeters were used to provide the high voltage supply, amplifier and single channel analyser in a ruggedised form of proven reliability. The combined use of thin crystal detectors and single channel analyser allowed a significant reduction in background count rates while maintaining the efficiency for detection of the 60 keV gamma-ray. To allow efficient and reliable coverage, the vehicle was fitted with a high-resolution speedometer to allow the proper speed to be maintained, and a mapping display, based on the GPS system, which showed the previous path of the vehicle and boundary of the area to be scanned. Whenever a radioactive particle was detected, its coordinates were

  5. Multi-color single particle tracking with quantum dots.

    Directory of Open Access Journals (Sweden)

    Eva C Arnspang

    Full Text Available Quantum dots (QDs have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT. In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a lipid, biotin-cap-DPPE, in the cellular plasma membrane of live cells using four different colors of QDs; QD565, QD605, QD655, and QD705 as labels.

  6. Single particle aerosol mass spectrometry of coal combustion particles associated with high lung cancer rates in Xuanwei and Fuyuan, China.

    Science.gov (United States)

    Lu, Senlin; Tan, Zhengying; Liu, Pinwei; Zhao, Hui; Liu, Dingyu; Yu, Shang; Cheng, Ping; Win, Myat Sandar; Hu, Jiwen; Tian, Linwei; Wu, Minghong; Yonemochi, Shinich; Wang, Qingyue

    2017-11-01

    Coal combustion particles (CCPs) are linked to the high incidence of lung cancer in Xuanwei and in Fuyuan, China, but studies on the chemical composition of the CCPs are still limited. Single particle aerosol mass spectrometry (SPAMS) was recently developed to measure the chemical composition and size of single particles in real-time. In this study, SPAMS was used to measure individual combustion particles emitted from Xuanwei and Fuyuan coal samples and the results were compared with those by ICP-MS and transmission electron microscopy (TEM). The total of 38,372 particles mass-analyzed by SPAMS can be divided into 9 groups based on their chemical composition and their number percentages: carbonaceous, Na-rich, K-rich, Al-rich, Fe-rich, Si-rich, Ca-rich, heavy metal-bearing, and PAH-bearing particles. The carbonaceous and PAH-bearing particles are enriched in the size range below 0.56 μm, Fe-bearing particles range from 0.56 to 1.0 μm in size, and heavy metals such as Ti, V, Cr, Cu, Zn, and Pb have diameters below 1 μm. The TEM results show that the particles from Xuanwei and Fuyuan coal combustion can be classified into soot aggregates, Fe-rich particles, heavy metal containing particles, and mineral particles. Non-volatile particles detected by SPAMS could also be observed with TEM. The number percentages by SPAMS also correlate with the mass concentrations measured by ICP-MS. Our results could provide valuable insight for understanding high lung cancer incidence in the area. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 m. Particle concentrations not exceeding 3.5 106 particles/m3 (100 000/ft 3) are covered for all particles equal to and larger than the minimum size measured. 1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size. Note 1The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling...

  8. Apparatus and method for detection and characterization of particles using light scattered therefrom

    Science.gov (United States)

    Johnston, R.G.

    1987-03-23

    Apparatus and method for detection and characterization of particles using light scattered therefrom. Differential phase measurements on scattered light from particles are possible using the two-frequency Zeeman effect laser which emits two frequencies of radiation 250 kHz apart. Excellent discrimination and reproducibility for various pure pollen and bacterial samples in suspension have been observed with a single polarization element. Additionally, a 250 kHz beat frequency was recorded from an individual particle traversing the focused output from the laser in a flow cytometer. 13 figs.

  9. New apparatus of single particle trap system for aerosol visualization

    Science.gov (United States)

    Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio

    2014-08-01

    Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.

  10. Particle detection with superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Jany, P.

    1990-08-01

    At the Institute of Experimental Nuclear Physics of the University of Karlsruhe (TH) and at the Institute for Nuclear Physics of the Kernforschungszentrum Karlsruhe we started to produce superconducting tunnel junctions and to investigate them for their suitability as particle detectors. The required facilities for the production of tunnel junctions and the experimental equipments to carry out experiments with them were erected. Experiments are presented in which radiations of different kinds of particles could successfully be measured with the tunnel junctions produced. At first we succeeded in detectioning light pulses of a laser. In experiments with alpha-particles of an energy of 4,6 MeV the alpha-particles were detected with an energy resolution of 1,1%, and it was shown in specific experiments that the phonons originating from the deposition of energy by an alpha-particle in the substrate can be detected with superconducting tunnel junctions at the surface. On that occasion it turned out that the signals could be separated with respect to their point of origin (tunnel junction, contact leads, substrate). Finally X-rays with an energy of 6 keV were detected with an energy resolution of 8% in a test arrangement that makes use of the so-called trapping effect to read out a larger absorber volume. (orig.) [de

  11. Single-particle density matrix of liquid 4He

    International Nuclear Information System (INIS)

    Vakarchuk, I.A.

    2008-01-01

    The density single-particle matrix in the coordinate notation was calculated based on the expression for the interacting Bose-particle N system density matrix. Under the low temperatures the mentioned matrix in the first approximation enables to reproduce the Bogoliubov theory results. In the classical terms the mentioned theory enables to reproduce the results of the theory of the classical fluids in the approximation of the chaotic phases. On the basis of the density single-particle matrix one managed to obtain the function of the pulse distribution of the particles, the Bose-liquid average kinetic energy, and to study the Bose-Einstein condensation phenomenon [ru

  12. Electro-optical detection of charged particles

    International Nuclear Information System (INIS)

    Semertzidis, Y.K.; Castillo, V.; Kowalski, L.; Kraus, D.E.; Larsen, R.; Lazarus, D.M.; Magurno, B.; Nikas, D.; Ozben, C.; Srinivasan-Rao, T.; Tsang, T.

    2000-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO 3 crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams

  13. Electro-optical detection of charged particles

    CERN Document Server

    Semertzidis, Y K; Kowalski, L A; Kraus, D E; Larsen, R; Lazarus, D M; Magurno, B; Nikas, D; Ozben, C; Srinivasan-Rao, T; Tsang, Thomas

    2000-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO sub 3 crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams.

  14. Electro-optical detection of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Semertzidis, Y.K.; Castillo, V.; Kowalski, L.; Kraus, D.E.; Larsen, R.; Lazarus, D.M. E-mail: lazarus@sun2.bnl.gov; Magurno, B.; Nikas, D.; Ozben, C.; Srinivasan-Rao, T.; Tsang, T

    2000-10-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO{sub 3} crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams.

  15. Automated data collection in single particle electron microscopy

    Science.gov (United States)

    Tan, Yong Zi; Cheng, Anchi; Potter, Clinton S.; Carragher, Bridget

    2016-01-01

    Automated data collection is an integral part of modern workflows in single particle electron microscopy (EM) research. This review surveys the software packages available for automated single particle EM data collection. The degree of automation at each stage of data collection is evaluated, and the capabilities of the software packages are described. Finally, future trends in automation are discussed. PMID:26671944

  16. Single particle irradiation effect of digital signal processor

    International Nuclear Information System (INIS)

    Fan Si'an; Chen Kenan

    2010-01-01

    The single particle irradiation effect of high energy neutron on digital signal processor TMS320P25 in dynamic working condition has been studied. The influence of the single particle on the device has been explored through the acquired waveform and working current of TMS320P25. Analysis results, test data and test methods have also been presented. (authors)

  17. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Sancho-Parramon, J. [Rudjer Boskovic Institute, Bijenicka c. 54, Zagreb 10002 (Croatia); Jover, E.; Bertran, E. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Canillas, A., E-mail: acanillas@ub.ed [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain)

    2011-02-28

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 {mu}m and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  18. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    International Nuclear Information System (INIS)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O.; Sancho-Parramon, J.; Jover, E.; Bertran, E.; Canillas, A.

    2011-01-01

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 μm and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  19. Single-particle states vs. collective modes: friends or enemies ?

    Science.gov (United States)

    Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

    2018-05-01

    The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The collective mode arises as the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger spacings between relevant single particle states. Thus, the single-particle state and the collective mode are "enemies" against each other. However, the nuclear forces are rich enough so as to enhance relevant collective mode by reducing the resistance power by changing single-particle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, the quantum self-organization occurs: single-particle energies can be self-organized by (i) two quantum liquids, e.g., protons and neutrons, (ii) monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger.

  20. Highly sensitive immunoassay of protein molecules based on single nanoparticle fluorescence detection in a nanowell

    Science.gov (United States)

    Han, Jin-Hee; Kim, Hee-Joo; Lakshmana, Sudheendra; Gee, Shirley J.; Hammock, Bruce D.; Kennedy, Ian M.

    2011-03-01

    A nanoarray based-single molecule detection system was developed for detecting proteins with extremely high sensitivity. The nanoarray was able to effectively trap nanoparticles conjugated with biological sample into nanowells by integrating with an electrophoretic particle entrapment system (EPES). The nanoarray/EPES is superior to other biosensor using immunoassays in terms of saving the amounts of biological solution and enhancing kinetics of antibody binding due to reduced steric hindrance from the neighboring biological molecules. The nanoarray patterned onto a layer of PMMA and LOL on conductive and transparent indium tin oxide (ITO)-glass slide by using e-beam lithography. The suspension of 500 nm-fluorescent (green emission)-carboxylated polystyrene (PS) particles coated with protein-A followed by BDE 47 polyclonal antibody was added to the chip that was connected to the positive voltage. The droplet was covered by another ITO-coated-glass slide and connected to a ground terminal. After trapping the particles into the nanowells, the solution of different concentrations of anti-rabbit- IgG labeled with Alexa 532 was added for an immunoassay. A single molecule detection system could quantify the anti-rabbit IgG down to atto-mole level by counting photons emitted from the fluorescent dye bound to a single nanoparticle in a nanowell.

  1. Dual color single particle tracking via nanobodies

    International Nuclear Information System (INIS)

    Albrecht, David; Winterflood, Christian M; Ewers, Helge

    2015-01-01

    Single particle tracking is a powerful tool to investigate the function of biological molecules by following their motion in space. However, the simultaneous tracking of two different species of molecules is still difficult to realize without compromising the length or density of trajectories, the localization accuracy or the simplicity of the assay. Here, we demonstrate a simple dual color single particle tracking assay using small, bright, high-affinity labeling via nanobodies of accessible targets with widely available instrumentation. We furthermore apply a ratiometric step-size analysis method to visualize differences in apparent membrane viscosity. (paper)

  2. Study on the fragmentation of granite due to the impact of single particle and double particles

    Directory of Open Access Journals (Sweden)

    Yuchun Kuang

    2016-09-01

    Full Text Available Particle Impact Drilling (PID is a novel method to improve the rate of penetration (ROP. In order to further improve the performance of PID, an investigation into the effect of single and double particles: (1 diameter; (2 initial velocity; (3 distance; and (4 angle of incidence was undertaken to investigate their effects on broken volume and penetration depth into hard brittle rock. For this purpose, the laboratory experiment of single particle impact rock was employed. Meanwhile, based on the LS-DYNA, a new finite element (FE simulation of the PID, including single and double particles impact rock, has been presented. The 3-dimensional (3D, aix-symmetric, dynamic-explicit, Lagrangian model has been considered in this simulation. And the Elastic and Holmquist Johnson Cook (HJC material behaviors have been used for particles and rocks, respectively. The FE simulation results of single particle impacting rock are good agreement with experimental data. Furthermore, in this article the optimal impact parameters, including diameter, initial velocity, distance and the angle of incidence, are obtained in PID.

  3. Irradiation of single cells with individual high-LET particles

    International Nuclear Information System (INIS)

    Nelson, J.M.; Braby, L.A.

    1993-01-01

    The dose-limiting normal tissue of concern when irradiating head and neck lesions is often the vascular endothelium within the treatment field. Consequently, the response of capillary endothelial cells exposed to moderate doses of high LET particles is essential for establishing exposure limits for neutron-capture therapy. In an effort to characterize the high-LET radiation biology of cultured endothelial cells, the authors are attempting to measure cellular response to single particles. The single-particle irradiation apparatus, described below, allows them to expose individual cells to known numbers of high-LET particles and follow these cells for extended periods, in order to assess the impact of individual particles on cell growth kinetics. Preliminary cell irradiation experiments have revealed complications related to the smooth and efficient operation of the equipment; these are being resolved. Therefore, the following paragraphs deal primarily with the manner by which high LET particles deposit energy, the requirements for single-cell irradiation, construction and assembly of such apparatus, and testing of experimental procedures, rather than with the radiation biology of endothelial cells

  4. Dual-Channel Particle Filter Based Track-Before-Detect for Monopulse Radar

    Directory of Open Access Journals (Sweden)

    Fei Cai

    2014-01-01

    Full Text Available A particle filter based track-before-detect (PF-TBD algorithm is proposed for the monopulse high pulse repetition frequency (PRF pulse Doppler radar. The actual measurement model is adopted, in which the range is highly ambiguous and the sum and difference channels exist in parallel. A quantization method is used to approximate the point spread function to reduce the computation load. The detection decisions of the PF-TBD are fed to a binary integrator to further improve the detection performance. Simulation results show that the proposed algorithm can detect and track the low SNR target efficiently. The detection performance is improved significantly for both the single frame and the multiframe detection compared with the classical detector. A performance comparison with the PF-TBD using sum channel only is also supplied.

  5. Considerations of particle vaporization and analyte diffusion in single-particle inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Ho, Koon-Sing; Lui, Kwok-On; Lee, Kin-Ho; Chan, Wing-Tat

    2013-01-01

    The intensity of individual gold nanoparticles with nominal diameters of 80, 100, 150, and 200 nm was measured using single-particle inductively coupled plasma-mass spectrometry (ICP-MS). Since the particles are not perfectly monodisperse, a distribution of ICP-MS intensity was obtained for each nominal diameter. The distribution of particle mass was determined from the transmission electron microscopy (TEM) image of the particles. The distribution of ICP-MS intensity and the distribution of particle mass for each nominal diameter were correlated to give a calibration curve. The calibration curves are linear, but the slope decreases as the nominal diameter increases. The reduced slope is probably due to a smaller degree of vaporization of the large particles. In addition to the degree of particle vaporization, the rate of analyte diffusion in the ICP is an important factor that determines the measured ICP-MS intensity. Simulated ICP-MS intensity versus particle size was calculated using a simple computer program that accounts for the vaporization rate of the gold nanoparticles and the diffusion rate and degree of ionization of the gold atoms. The curvature of the simulated calibration curves changes with sampling depth because the effects of particle vaporization and analyte diffusion on the ICP-MS intensity are dependent on the residence time of the particle in the ICP. Calibration curves of four hypothetical particles representing the four combinations of high and low boiling points (2000 and 4000 K) and high and low analyte diffusion rates (atomic masses of 10 and 200 Da) were calculated to further illustrate the relative effects of particle vaporization and analyte diffusion. The simulated calibration curves show that the sensitivity of single-particle ICP-MS is smaller than that of the ICP-MS measurement of continuous flow of standard solutions by a factor of 2 or more. Calibration using continuous flow of standard solution is semi-quantitative at best. An

  6. Report of the working group on single-particle nonlinear dynamics

    International Nuclear Information System (INIS)

    Bazzani, A.; Bongini, L.; Corbett, J.; Dome, G.; Fedorova, A.; Freguglia, P.; Ng, K.; Ohmi, K.; Owen, H.; Papaphilippou, Y.; Robin, D.; Safranek, J.; Scandale, W.; Terebilo, A.; Turchetti, G.; Todesco, E.; Warnock, R.; Zeitlin, M.

    1999-01-01

    The Working Group on single-particle nonlinear dynamics has developed a set of tools to study nonlinear dynamics in a particle accelerator. The design of rings with large dynamic apertures is still far from automatic. The Working Group has concluded that nonlinear single-particle dynamics limits the performance of accelerators. (AIP) copyright 1999 American Institute of Physics

  7. Quantitative determination of carbonaceous particle mixing state in Paris using single particle mass spectrometer and aerosol mass spectrometer measurements

    Science.gov (United States)

    Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.

    2013-04-01

    Single particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been estimated using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulphate and potassium were compared with concurrent measurements from an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal/optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and ten discrete mixing states for carbonaceous particles were identified and quantified. Potassium content was used to identify particles associated with biomass combustion. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorization, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulphate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA/EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidized OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the heterogeneity of primary and

  8. Mass Spectrometry of Single Particles Levitated in an Electrodynamic Balance: Applications to Laboratory Atmospheric Chemistry Research

    Science.gov (United States)

    Birdsall, A.; Krieger, U. K.; Keutsch, F. N.

    2017-12-01

    Dynamic changes to atmospheric aerosol particle composition (e.g., originating from evaporation/condensation, oxidative aging, or aqueous-phase chemical reactions) impact particle properties with importance for understanding particle effects on climate and human health. These changes can take place over the entire lifetime of an atmospheric particle, which can extend over multiple days. Previous laboratory studies of such processes have included analyzing single particles suspended in a levitation device, such as an electrodynamic balance (EDB), an optical levitator, or an acoustic trap, using optical detection techniques. However, studying chemically complex systems can require an analytical method, such as mass spectrometry, that provides more molecular specificity. Existing work coupling particle levitation with mass spectrometry is more limited and largely has consisted of acoustic levitation of millimeter-sized droplets.In this work an EDB has been coupled with a custom-built ionization source and commercial time-of-flight mass spectrometer (MS) as a platform for laboratory atmospheric chemistry research. Single charged particles (radius 10 μm) have been injected into an EDB, levitated for an arbitrarily long period of time, and then transferred to a vaporization-corona discharge ionization region for MS analysis. By analyzing a series of particles of identical composition, residing in the controlled environment of the EDB for varying times, we can trace the chemical evolution of a particle over hours or days, appropriate timescales for understanding transformations of atmospheric particles.To prove the concept of our EDB-MS system, we have studied the evaporation of particles consisting of polyethylene glycol (PEG) molecules of mixed chain lengths, used as a benchmark system. Our system can quantify the composition of single particles (see Figure for sample spectrum of a single PEG-200 particle: PEG parent ions labeled with m/z, known PEG fragment ions

  9. Single particle analysis of TiO2 in candy products using triple quadrupole ICP-MS.

    Science.gov (United States)

    Candás-Zapico, S; Kutscher, D J; Montes-Bayón, M; Bettmer, J

    2018-04-01

    Titanium dioxide (TiO 2 ) belongs to the materials that have gained great importance in many applications. In its particulate form (micro- or nanoparticles), it has entered a huge number of consumer products and food-grade TiO 2 , better known as E171 within the European Union, represents an important food additive. Thus, there is an increasing need for analytical methods able to detect and quantify such particles. In this regard, inductively coupled-mass spectrometry (ICP-MS), in particular single particle ICP-MS (spICP-MS), has gained importance due to its simplicity and ease of use. Nevertheless, the number of applications for Ti nanoparticles is rather limited. In this study, we have applied the spICP-MS strategy by comparing different measuring modes available in triple quadrupole ICP-MS. First, single quadrupole mode using the collision/reaction cell system was selected for monitoring the isotope 47 Ti. Different cell gases like He, O 2 and NH 3 were tested under optimised conditions for its applicability in spICP-MS of standard suspensions of TiO 2 . The determined analytical figures of merit were compared to those obtained by triple quadrupole mode using the 47 Ti or 48 Ti reaction products using O 2 and NH 3 as reaction gases. This comparison demonstrated that the triple quadrupole mode (TQ mode) was superior in terms of sensitivity due to the more efficient removal of spectral interferences. Particle size detection limits down to 26nm were obtained using the best instrumental conditions for TiO 2 particles at a dwell time of 10ms. Finally, the different measuring modes were applied to the analysis of chewing gum samples after a simple extraction procedure using an ultrasonic bath. The obtained results showed a good agreement for the detected particle size range using the different TQ modes. The size range of TiO 2 particles was determined to be between approximately 30 and 200nm, whereas roughly 40% of the particles were smaller than 100nm. For the

  10. Single particle characterization using a light scattering module coupled to a time-of-flight aerosol mass spectrometer

    Science.gov (United States)

    Cross, E. S.; Onasch, T. B.; Canagaratna, M.; Jayne, J. T.; Kimmel, J.; Yu, X.-Y.; Alexander, M. L.; Worsnop, D. R.; Davidovits, P.

    2008-12-01

    We present the first single particle results obtained using an Aerodyne time-of-flight aerosol mass spectrometer coupled with a light scattering module (LS-ToF-AMS). The instrument was deployed at the T1 ground site approximately 40 km northeast of the Mexico City Metropolitan Area (MCMA) as part of the MILAGRO field study in March of 2006. The instrument was operated as a standard AMS from 12-30 March, acquiring average chemical composition and size distributions for the ambient aerosol, and in single particle mode from 27-30 March. Over a 75-h sampling period, 12 853 single particle mass spectra were optically triggered, saved, and analyzed. The correlated optical and chemical detection allowed detailed examination of single particle collection and quantification within the LS-ToF-AMS. The single particle data enabled the mixing states of the ambient aerosol to be characterized within the context of the size-resolved ensemble chemical information. The particulate mixing states were examined as a function of sampling time and most of the particles were found to be internal mixtures containing many of the organic and inorganic species identified in the ensemble analysis. The single particle mass spectra were deconvolved, using techniques developed for ensemble AMS data analysis, into HOA, OOA, NH4NO3, (NH4)2SO4, and NH4Cl fractions. Average single particle mass and chemistry measurements are shown to be in agreement with ensemble MS and PTOF measurements. While a significant fraction of ambient particles were internal mixtures of varying degrees, single particle measurements of chemical composition allowed the identification of time periods during which the ambient ensemble was externally mixed. In some cases the chemical composition of the particles suggested a likely source. Throughout the full sampling period, the ambient ensemble was an external mixture of combustion-generated HOA particles from local sources (e.g. traffic), with number concentrations peaking

  11. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    International Nuclear Information System (INIS)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun

    2012-01-01

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/√Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 μm with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 μm, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  12. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun, E-mail: sxu7@uh.edu [University of Houston, Department of Chemistry (United States)

    2012-09-15

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/{radical}Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 {mu}m with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 {mu}m, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  13. Entanglement of identical particles and the detection process

    DEFF Research Database (Denmark)

    Tichy, Malte C.; de Melo, Fernando; Kus, Marek

    2013-01-01

    We introduce detector-level entanglement, a unified entanglement concept for identical particles that takes into account the possible deletion of many-particle which-way information through the detection process. The concept implies a measure for the effective indistinguishability of the particles...... statistical behavior depends on their initial entanglement. Our results show that entanglement cannot be attributed to a state of identical particles alone, but that the detection process has to be incorporated in the analysis....

  14. Multiplexed detection of metabolites of narcotic drugs from a single latent fingermark.

    Science.gov (United States)

    Hazarika, Pompi; Jickells, Sue M; Wolff, Kim; Russell, David A

    2010-11-15

    An immunoassay based technique is used for the detection of psychoactive substances in the sweat deposited within fingermarks of a narcotic drug user. Magnetic particles functionalized with antimorphine and antibenzoylecgonine antibodies were used for the detection of a metabolite of heroin (morphine) and a metabolite of cocaine (benzoylecgonine), respectively. The drug metabolites were detected individually as well as simultaneously from a single fingermark. The images of the fingermarks obtained using brightfield and fluorescence microscopy were of high evidential quality with resolution to enable identification of an individual in addition to providing information on drug usage.

  15. Evolution of single-particle structure of silicon isotopes

    Science.gov (United States)

    Bespalova, O. V.; Fedorov, N. A.; Klimochkina, A. A.; Markova, M. L.; Spasskaya, T. I.; Tretyakova, T. Yu.

    2018-01-01

    New data on proton and neutron single-particle energies E_{nlj} of Si isotopes with neutron number N from 12 to 28 as well as occupation probabilities N_{nlj} of single-particle states of stable isotopes 28, 30Si near the Fermi energy were obtained by the joint evaluation of the stripping and pick-up reaction data and excited state decay schemes of neighboring nuclei. The evaluated data indicate the following features of single-particle structure evolution: persistence of Z = 14 subshell closure with N increase, the new magicity of the number N = 16, and the conservation of the magic properties of the number N = 20 in Si isotopic chain. The features were described by the dispersive optical model. The calculation also predicts the weakening of N = 28 shell closure and demonstrates evolution of a bubble-like structure of the proton density distributions in neutron-rich Si isotopes.

  16. Ghost hunting—an assessment of ghost particle detection and removal methods for tomographic-PIV

    International Nuclear Information System (INIS)

    Elsinga, G E; Tokgoz, S

    2014-01-01

    This paper discusses and compares several methods, which aim to remove spurious peaks, i.e. ghost particles, from the volume intensity reconstruction in tomographic-PIV. The assessment is based on numerical simulations of time-resolved tomographic-PIV experiments in linear shear flows. Within the reconstructed volumes, intensity peaks are detected and tracked over time. These peaks are associated with particles (either ghosts or actual particles) and are characterized by their peak intensity, size and track length. Peak intensity and track length are found to be effective in discriminating between most ghosts and the actual particles, although not all ghosts can be detected using only a single threshold. The size of the reconstructed particles does not reveal an important difference between ghosts and actual particles. The joint distribution of peak intensity and track length however does, under certain conditions, allow a complete separation of ghosts and actual particles. The ghosts can have either a high intensity or a long track length, but not both combined, like all the actual particles. Removing the detected ghosts from the reconstructed volume and performing additional MART iterations can decrease the particle position error at low to moderate seeding densities, but increases the position error, velocity error and tracking errors at higher densities. The observed trends in the joint distribution of peak intensity and track length are confirmed by results from a real experiment in laminar Taylor–Couette flow. This diagnostic plot allows an estimate of the number of ghosts that are indistinguishable from the actual particles. (paper)

  17. Probing correlated quantum many-body systems at the single-particle level

    Energy Technology Data Exchange (ETDEWEB)

    Endres, Manuel

    2013-02-27

    The detection of correlation and response functions plays a crucial role in the experimental characterization of quantum many-body systems. In this thesis, we present novel techniques for the measurement of such functions at the single-particle level. Specifically, we show the single-atom- and single-site-resolved detection of an ultracold quantum gas in an optical lattice. The quantum gas is described by the Bose-Hubbard model, which features a zero temperature phase transition from a superfluid to a Mott-insulating state, a paradigm example of a quantum phase transition. We used the aforementioned detection techniques to study correlation and response properties across the superfluid-Mott-insulator transition. The single-atom sensitivity of our method is achieved by fluorescence detection of individual atoms with a high signal-to-noise ratio. A high-resolution objective collects the fluorescence light and yields in situ 'snapshots' of the quantum gas that allow for a single-site-resolved reconstruction of the atomic distribution. This allowed us to measure two-site and non-local correlation-functions across the superfluid-Mott-insulator transition. Non-local correlation functions are based on the information of an extended region of the system and play an important role for the characterization of low-dimensional quantum phases. While non-local correlation functions were so far only theoretical tools, our results show that they are actually experimentally accessible. Furthermore, we used a new thermometry scheme, based on the counting of individual thermal excitations, to measure the response of the system to lattice modulation. Using this method, we studied the excitation spectrum of the system across the two-dimensional superfluid-Mott-insulator transition. In particular, we detected a 'Higgs' amplitude mode in the strongly-interacting superfluid close to the transition point where the system is described by an effectively Lorentz

  18. Probing correlated quantum many-body systems at the single-particle level

    International Nuclear Information System (INIS)

    Endres, Manuel

    2013-01-01

    The detection of correlation and response functions plays a crucial role in the experimental characterization of quantum many-body systems. In this thesis, we present novel techniques for the measurement of such functions at the single-particle level. Specifically, we show the single-atom- and single-site-resolved detection of an ultracold quantum gas in an optical lattice. The quantum gas is described by the Bose-Hubbard model, which features a zero temperature phase transition from a superfluid to a Mott-insulating state, a paradigm example of a quantum phase transition. We used the aforementioned detection techniques to study correlation and response properties across the superfluid-Mott-insulator transition. The single-atom sensitivity of our method is achieved by fluorescence detection of individual atoms with a high signal-to-noise ratio. A high-resolution objective collects the fluorescence light and yields in situ 'snapshots' of the quantum gas that allow for a single-site-resolved reconstruction of the atomic distribution. This allowed us to measure two-site and non-local correlation-functions across the superfluid-Mott-insulator transition. Non-local correlation functions are based on the information of an extended region of the system and play an important role for the characterization of low-dimensional quantum phases. While non-local correlation functions were so far only theoretical tools, our results show that they are actually experimentally accessible. Furthermore, we used a new thermometry scheme, based on the counting of individual thermal excitations, to measure the response of the system to lattice modulation. Using this method, we studied the excitation spectrum of the system across the two-dimensional superfluid-Mott-insulator transition. In particular, we detected a 'Higgs' amplitude mode in the strongly-interacting superfluid close to the transition point where the system is described by an effectively Lorentz-invariant low-energy theory

  19. Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2013-09-01

    Full Text Available Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC, organic aerosol (OA, ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a thermal–optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC. ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78, and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the

  20. Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

    Science.gov (United States)

    Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.

    2013-09-01

    Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal-optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the temporal

  1. Single-particle characterization of 'Asian Dust' certified reference materials using low-Z particle electron probe X-ray microanalysis

    International Nuclear Information System (INIS)

    Hwang, Hee Jin; Ro, Chul-Un

    2006-01-01

    In order to clearly elucidate whether Asian Dust particles experience chemical modification during long-range transport, it is necessary to characterize soil particles where Asian Dust particles originate. If chemical compositions of source soil particles are well characterized, then chemical compositions of Asian Dust particles collected outside source regions can be compared with those of source soil particles in order to find out the occurrence of chemical modification. Asian Dust particles are chemically and morphologically heterogeneous, and thus the average composition and the average aerodynamic diameter (obtainable by bulk analysis) are not much relevant if the chemical modifications of the particles must be followed. The major elemental composition and abundance of the particle types that are potential subjects of chemical modification can only be obtained using single-particle analysis. A single particle analytical technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize two certified reference materials (CRMs) for Asian Dust particles, which were collected from a loess plateau area and a desert of China. The CRMs were defined by bulk analyses to provide certified concentrations for 13 chemical elements. Using the low-Z particle EPMA technique, the concentrations of major chemical species such as aluminosilicates, SiO 2 , CaCO 3 , and carbonaceous species were obtained. Elemental concentrations obtained by the low-Z particle EPMA are close to the certified values, with considering that the single particle and bulk analyses employ very different approaches. There are still some discrepancies between those concentration values, resulting from analyses of particles with different sizes, different sample amounts analyzed, and uncertainties involved in the single particle analysis

  2. Evolution of single-particle structure of silicon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bespalova, O.V.; Klimochkina, A.A.; Spasskaya, T.I.; Tretyakova, T.Yu. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Fedorov, N.A.; Markova, M.L. [Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation)

    2018-01-15

    New data on proton and neutron single-particle energies E{sub nlj} of Si isotopes with neutron number N from 12 to 28 as well as occupation probabilities N{sub nlj} of single-particle states of stable isotopes {sup 28,30}Si near the Fermi energy were obtained by the joint evaluation of the stripping and pick-up reaction data and excited state decay schemes of neighboring nuclei. The evaluated data indicate the following features of single-particle structure evolution: persistence of Z = 14 subshell closure with N increase, the new magicity of the number N = 16, and the conservation of the magic properties of the number N = 20 in Si isotopic chain. The features were described by the dispersive optical model. The calculation also predicts the weakening of N = 28 shell closure and demonstrates evolution of a bubble-like structure of the proton density distributions in neutron-rich Si isotopes. (orig.)

  3. Fragmentation of single-particle states in deformed nuclei

    International Nuclear Information System (INIS)

    Malov, L.A.; Soloviev, V.G.

    1975-01-01

    Fragmentation of single-particle states on levels of deformed nuclei is studied on the example of 239 U and 169 Er nuclei in the framework of the model taking into consideration the interaction of quasiparticles with phonons. The dependence of fragmentation on the Fermi surface is considered from the viewpoint of single-particle levels. It is shown that in the distribution of single-particle strength functions a second maximum appears together with the large asymmetry maximum at high-energy excitation, and the distribution has a long ''tail''. A semimicroscopic approach is proposed for calculating the neutron strength functions. The following values of the strength functions are obtained: for sub(239)U-Ssub(0)sup(cal)=1.2x10sup(-4), Ssub(1)sup(cal)=2.7x10sub(-4) and for sub(169)Er-Ssub(0)sup(cal)=1.10sup(-4), Ssub(1)sup(cal)=1.2x10sup(-4)

  4. Microfluidic CODES: a scalable multiplexed electronic sensor for orthogonal detection of particles in microfluidic channels.

    Science.gov (United States)

    Liu, Ruxiu; Wang, Ningquan; Kamili, Farhan; Sarioglu, A Fatih

    2016-04-21

    Numerous biophysical and biochemical assays rely on spatial manipulation of particles/cells as they are processed on lab-on-a-chip devices. Analysis of spatially distributed particles on these devices typically requires microscopy negating the cost and size advantages of microfluidic assays. In this paper, we introduce a scalable electronic sensor technology, called microfluidic CODES, that utilizes resistive pulse sensing to orthogonally detect particles in multiple microfluidic channels from a single electrical output. Combining the techniques from telecommunications and microfluidics, we route three coplanar electrodes on a glass substrate to create multiple Coulter counters producing distinct orthogonal digital codes when they detect particles. We specifically design a digital code set using the mathematical principles of Code Division Multiple Access (CDMA) telecommunication networks and can decode signals from different microfluidic channels with >90% accuracy through computation even if these signals overlap. As a proof of principle, we use this technology to detect human ovarian cancer cells in four different microfluidic channels fabricated using soft lithography. Microfluidic CODES offers a simple, all-electronic interface that is well suited to create integrated, low-cost lab-on-a-chip devices for cell- or particle-based assays in resource-limited settings.

  5. Modeling of calcination of single kaolinitic clay particle

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    The present work aims at modeling of the calcination (dehydroxylation) process of clay particles, specifically kaolinite, and its thermal transformation. For such purpose, 1D single particle calcination model was developed based on the concept of shrinking core model to assess the dehydroxylation...

  6. Semiempirical formulas for single-particle energies of neutrons and protons

    International Nuclear Information System (INIS)

    Lodhi, M.A.K.; Waak, B.T.

    1978-01-01

    The stepwise multiple linear regression technique has been used to analyze the single-particle energies of neutrons and protons in nuclei along the line of beta stability. Their regular and systematic trends lead to semiempirical model-independent formulas for single-particle energies of neutrons and protons in the bound nuclei as functions of nuclear parameters A and Z for given states specified by nl/sub j/. These formulas are almost as convenient as the harmonic oscillator energy formulas to use. The single-particle energies computed from these formulas have been compared with the experimental data and are found in reasonable agreement

  7. Experiments and modeling of single plastic particle conversion in suspension

    DEFF Research Database (Denmark)

    Nakhaei, Mohammadhadi; Wu, Hao; Grévain, Damien

    2018-01-01

    Conversion of single high density polyethylene (PE) particles has been studied by experiments and modeling. The experiments were carried out in a single particle combustor for five different shapes and masses of particles at temperature conditions of 900 and 1100°C. Each experiment was recorded...... against the experiments as well as literature data. Furthermore, a simplified isothermal model appropriate for CFD applications was developed, in order to model the combustion of plastic particles in cement calciners. By comparing predictions with the isothermal and the non–isothermal models under typical...

  8. Characterizing uranium oxide reference particles for isotopic abundances and uranium mass by single particle isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Kraiem, M.; Richter, S.; Erdmann, N.; Kühn, H.; Hedberg, M.; Aregbe, Y.

    2012-01-01

    Highlights: ► A method to quantify the U mass in single micron particles by ID-TIMS was developed. ► Well-characterized monodisperse U-oxide particles produced by an aerosol generator were used. ► A linear correlation between the mass of U and the volume of particle(s) was found. ► The method developed is suitable for determining the amount of U in a particulate reference material. - Abstract: Uranium and plutonium particulate test materials are becoming increasingly important as the reliability of measurement results has to be demonstrated to regulatory bodies responsible for maintaining effective nuclear safeguards. In order to address this issue, the Institute for Reference Materials and Measurements (IRMM) in collaboration with the Institute for Transuranium Elements (ITU) has initiated a study to investigate the feasibility of preparing and characterizing a uranium particle reference material for nuclear safeguards, which is finally certified for isotopic abundances and for the uranium mass per particle. Such control particles are specifically required to evaluate responses of instruments based on mass spectrometric detection (e.g. SIMS, TIMS, LA-ICPMS) and to help ensuring the reliability and comparability of measurement results worldwide. In this paper, a methodology is described which allows quantifying the uranium mass in single micron particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS). This methodology is characterized by substantial improvements recently achieved at IRMM in terms of sensitivity and measurement accuracy in the field of uranium particle analysis by TIMS. The use of monodisperse uranium oxide particles prepared using an aerosol generation technique developed at ITU, which is capable of producing particles of well-characterized size and isotopic composition was exploited. The evidence of a straightforward correlation between the particle volume and the mass of uranium was demonstrated in this study

  9. Single particle composition measurements of artificial Calcium Carbonate aerosols

    Science.gov (United States)

    Zorn, S. R.; Mentel, T. F.; Schwinger, T.; Croteau, P. L.; Jayne, J.; Worsnop, D. R.; Trimborn, A.

    2012-12-01

    Mineral dust, with an estimated total source from natural and anthropogenic emissions of up to 2800 Tg/yr, is one of the two largest contributors to total aerosol mass, with only Sea salt having a similar source strength (up to 2600 Tg/yr). The composition of dust particles varies strongly depending on the production process and, most importantly, the source location. Therefore, the composition of single dust particles can be used both to trace source regions of air masses as well as to identify chemical aging processes. Here we present results of laboratory studies on generating artificial calcium carbonate (CaCO3) particles, a model compound for carbonaceous mineral dust particles. Particles were generated by atomizing an aqueous hydrogen carbonate solution. Water was removed using a silica diffusion dryer., then the particles were processed in an oven at temperatures up to 900°C, converting the hydrogen carbonate to its anhydrous form. The resulting aerosol was analyzed using an on-line single particle laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF). The results confirm the conversion to calcium carbonate, and validate that the produced particles indeed can be used as a model compound for carbonaceous dust aerosols.

  10. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  11. Fundamental Study of Single Biomass Particle Combustion

    DEFF Research Database (Denmark)

    Momenikouchaksaraei, Maryam

    This thesis is a comprehensive study of single biomass particle combustion. The effect of particle shape and size and operating conditions on biomass conversion characteristics were investigated experimentally and theoretically. The experimental samples were divided in two groups: particles...... well-defined conditions, and the complete combustion processes were recorded as video sequences by a CCD camera installed in the set-up. One of the project objectives is to simulate conditions reasonably close to the conditions in a power plant boiler, i.e., reasonably high temperatures (up to 1600°C...

  12. Burnout of pulverized biomass particles in large scale boiler - Single particle model approach

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero [VTT Technical Research Centre of Finland, Box 1603, 40101 Jyvaeskylae (Finland); Soerensen, Lasse Holst [ReaTech/ReAddit, Frederiksborgsveij 399, Niels Bohr, DK-4000 Roskilde (Denmark); Clausen, Soennik [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Berg, Mogens [ENERGI E2 A/S, A.C. Meyers Vaenge 9, DK-2450 Copenhagen SV (Denmark)

    2010-05-15

    Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. (author)

  13. Method to detect biological particles

    International Nuclear Information System (INIS)

    Giaever, I.

    1976-01-01

    A medical-diagnostic method to detect immunological as well as other specific reactions is described. According to the invention, first reactive particles (e.g. antibodies) are adsorbed on the surface of a solid, non-reactive substrate. The coated substrate is subjected to a solution which one assumes to contain the second biological particles (e.g. antigens) which are specific to the first and form complexes with these. A preferential radioactive labelling (e.g. with iodine 125) of the second biological particle is then directly or indirectly carried out. Clearage follows labelling in order to separate the second biological particles from the first ones. A specific splitting agent can selectively break the bond of both types of particle. The splitting agent solution is finally separated off and its content is investigated for the presence of labelling. (VJ) [de

  14. Acoustic Particle Detection with the ANTARES Detector

    Directory of Open Access Journals (Sweden)

    M. Neff

    2010-01-01

    Full Text Available The (Antares Modules for Acoustic Detection Under the Sea AMADEUS system within the (Astronomy with a Neutrino Telescope and Abyss environmental RESsearch ANTARES neutrino telescope is designed to investigate detection techniques for acoustic signals produced by particle cascades. While passing through a liquid a cascade deposits energy and produces a measurable pressure pulse. This can be used for the detection of neutrinos with energies exceeding 1018 eV. The AMADEUS setup consists of 36 hydrophones grouped in six local clusters measuring about one cubic meter each. This article focuses on acoustic particle detection, the hardware of the AMADEUS detector and techniques used for acoustic signal processing.

  15. Acoustic Particle Detection with the ANTARES Detector

    Directory of Open Access Journals (Sweden)

    Richardt C

    2010-01-01

    Full Text Available The (Antares Modules for Acoustic Detection Under the Sea AMADEUS system within the (Astronomy with a Neutrino Telescope and Abyss environmental RESsearch ANTARES neutrino telescope is designed to investigate detection techniques for acoustic signals produced by particle cascades. While passing through a liquid a cascade deposits energy and produces a measurable pressure pulse. This can be used for the detection of neutrinos with energies exceeding  eV. The AMADEUS setup consists of 36 hydrophones grouped in six local clusters measuring about one cubic meter each. This article focuses on acoustic particle detection, the hardware of the AMADEUS detector and techniques used for acoustic signal processing.

  16. Quadrupole moments of highly deformed structures in the A ∼ 135 region: Probing the single-particle motion in a rotating potential

    International Nuclear Information System (INIS)

    Laird, R.W.; Riley, M.A.; Brown, T.B.; Pfohl, J.; Sheline, R.K.; Kondev, F.G.; Archer, D.E.; Clark, R.M.; Fallon, P.; Devlin, M.; LaFosse, D.R.; Sarantites, D.G.; Hartley, D.J.; Hibbert, I.M.; O'Brien, N.J.; Wadsworth, R.; Joss, D.T.; Nolan, P.J.; Paul, E.S.; Shepherd, S.L.

    2002-01-01

    The latest generation γ-ray detection system, GAMMASPHERE, coupled with the Microball charged-particle detector, has made possible a new class of nuclear lifetime measurement. For the first time differential lifetime measurements free from common systematic errors for over 15 different nuclei (>30 rotational bands in various isotopes of Ce, Pr, Nd, Pm, and Sm) have been extracted at high spin within a single experiment. This comprehensive study establishes the effective single-particle transition quadrupole moments in the A∼135 light rare-earth region. Detailed comparisons are made with theoretical calculations using the self-consistent cranked mean-field theory which convincingly demonstrates the validity of the additivity of single-particle quadrupole moments in this mass region

  17. Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet.

    Science.gov (United States)

    Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

    2015-07-01

    Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

  18. Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

    Science.gov (United States)

    Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

    2015-01-01

    Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles. PMID:26221197

  19. Rationale for single molecule detection by means of Raman spectroscopy

    International Nuclear Information System (INIS)

    Gaponenko, S.V.; Guzatov, D.V.

    2009-01-01

    A consistent quantum electrodynamical description is proposed of Raman scattering of light by a molecule in a medium with a modified photon density of states. Enhanced local density of states near a metal nanobody is shown to increase a scattering rate by several orders of magnitude, thus providing a rationale for experimental detection of single molecules by means of Raman spectroscopy. For an ellipsoidal particle 10 14 -fold enhancement of the Raman scattering cross-section is obtained. (authors)

  20. Visualizing Ebolavirus Particles Using Single-Particle Interferometric Reflectance Imaging Sensor (SP-IRIS).

    Science.gov (United States)

    Carter, Erik P; Seymour, Elif Ç; Scherr, Steven M; Daaboul, George G; Freedman, David S; Selim Ünlü, M; Connor, John H

    2017-01-01

    This chapter describes an approach for the label-free imaging and quantification of intact Ebola virus (EBOV) and EBOV viruslike particles (VLPs) using a light microscopy technique. In this technique, individual virus particles are captured onto a silicon chip that has been printed with spots of virus-specific capture antibodies. These captured virions are then detected using an optical approach called interference reflectance imaging. This approach allows for the detection of each virus particle that is captured on an antibody spot and can resolve the filamentous structure of EBOV VLPs without the need for electron microscopy. Capture of VLPs and virions can be done from a variety of sample types ranging from tissue culture medium to blood. The technique also allows automated quantitative analysis of the number of virions captured. This can be used to identify the virus concentration in an unknown sample. In addition, this technique offers the opportunity to easily image virions captured from native solutions without the need for additional labeling approaches while offering a means of assessing the range of particle sizes and morphologies in a quantitative manner.

  1. Two-Step Single Particle Mass Spectrometry for On-Line Monitoring of Polycyclic Aromatic Hydrocarbons Bound to Ambient Fine Particulate Matter

    Science.gov (United States)

    Zimmermann, R.; Bente, M.; Sklorz, M.

    2007-12-01

    Polycyclic aromatic hydrocarbons (PAH) are formed as trace products in combustion processes and are emitted to the atmosphere. Larger PAH have low vapour pressure and are predominantly bound to the ambient fine particulate matter (PM). Upon inhalation, PAH show both, chronic human toxicity (i.e. many PAH are potent carcinogens) as well as acute human toxicity (i.e. inflammatory effects due to oxi-dative stress) and are discussed to be relevant for the observed health effect of ambient PM. Therefore a better understanding of the occurrence, dynamics and particle size dependence of particle bound-PAH is of great interest. On-line aerosol mass spectrometry in principle is the method of choice to investigate the size resolved changes in the chemical speciation of particles as well the status of internal vs. external mixing of chemical constituents. However the present available aerosol mass spectrometers (ATOFMS and AMS) do not allow detection of PAH from ambient air PM. In order to allow a single particle based monitoring of PAH from ambient PM a new single particle laser ionisation mass spectrometer was built and applied. The system is based on ATOFMS principle but uses a two- step photo-ionization. A tracked and sized particle firstly is laser desorbed (LD) by a IR-laser pulse (CO2-laser, λ=10.2 μm) and subsequently the released PAH are selectively ionized by an intense UV-laser pulse (ArF excimer, λ=248 nm) in a resonance enhanced multiphoton ionisation process (REMPI). The PAH-ions are detected in a time of flight mass spectrometer (TOFMS). A virtual impactor enrichment unit is used to increase the detection frequency of the ambient particles. With the current inlet system particles from about 400 nm to 10 μm are accessible. Single particle based temporal profiles of PAH containing particles ion (size distribution and PAH speciation) have been recorded in Oberschleissheim, Germany from ambient air. Furthermore profiles of relevant emission sources (e

  2. Laboratory Measurements of Single-Particle Polarimetric Spectrum

    Science.gov (United States)

    Gritsevich, M.; Penttila, A.; Maconi, G.; Kassamakov, I.; Helander, P.; Puranen, T.; Salmi, A.; Hæggström, E.; Muinonen, K.

    2017-12-01

    Measuring scattering properties of different targets is important for material characterization, remote sensing applications, and for verifying theoretical results. Furthermore, there are usually simplifications made when we model targets and compute the scattering properties, e.g., ideal shape or constant optical parameters throughout the target material. Experimental studies help in understanding the link between the observed properties and computed results. Experimentally derived Mueller matrices of studied particles can be used as input for larger-scale scattering simulations, e.g., radiative transfer computations. This method allows to bypass the problem of using an idealized model for single-particle optical properties. While existing approaches offer ensemble- and orientation-averaged particle properties, our aim is to measure individual particles with controlled or known orientation. With the newly developed scatterometer, we aim to offer novel possibility to measure single, small (down to μm-scale) targets and their polarimetric spectra. This work presents an experimental setup that measures light scattered by a fixed small particle with dimensions ranging between micrometer and millimeter sizes. The goal of our setup is nondestructive characterization of such particles by measuring light of multiple wavelengths scattered in 360° in a horizontal plane by an ultrasonically levitating sample, whilst simultaneously controlling its 3D position and orientation. We describe the principles and design of our instrument and its calibration. We also present example measurements of real samples. This study was conducted under the support from the European Research Council, in the frame of the Advanced Grant project No. 320773 `Scattering and Absorption of Electromagnetic Waves in Particulate Media' (SAEMPL).

  3. A Novel On-Chip Impedance Sensor for the Detection of Particle Contamination in Hydraulic Oil

    Directory of Open Access Journals (Sweden)

    Hongpeng Zhang

    2017-08-01

    Full Text Available A novel impedance sensor based on a microfluidic chip is presented. The sensor consists of two single-layer coils and a straight micro-channel, and can detect, not only ferromagnetic and non-ferromagnetic particles in oil as an inductive sensor, but also, water droplets and air bubbles in oil as a capacitive sensor. The experiments are carried out at different excitation frequencies, number of coil turns and particle sizes. For the inductance detection, the inductance signals are found to increase with the excitation frequency and the noise is constant; both the inductance signals and the noise increase with the number of coil turns, but because the noise increases at a faster rate than the signal, the signal-to-noise ratio decreases with the number of coil turns. We demonstrate the successful detection of 40 μm iron particles and 110 μm copper particles using the coil with 20 turns at the excitation frequency of 2 MHz. For the capacitance detection, capacitance signals decrease with the excitation frequency and the noise is constant; the capacitance signals decrease with the number of coil turns, while the noise increases, thus, the signal-to-noise ratio decreases with the number of coil turns. We can detect 100 μm water droplets and 180 μm bubbles successfully using the coil with 20 turns at the excitation frequency of 0.3 MHz.

  4. Single particle analysis with a 3600 light scattering photometer

    International Nuclear Information System (INIS)

    Bartholdi, M.F.

    1979-06-01

    Light scattering by single spherical homogeneous particles in the diameter range 1 to 20 μm and relative refractive index 1.20 is measured. Particle size of narrowly dispersed populations is determined and a multi-modal dispersion of five components is completely analyzed. A 360 0 light scattering photometer for analysis of single particles has been designed and developed. A fluid stream containing single particles intersects a focused laser beam at the primary focal point of an ellipsoidal reflector ring. The light scattered at angles theta = 2.5 0 to 177.5 0 at phi = 0 0 and 180 0 is reflected onto a circular array of photodiodes. The ellipsoidal reflector is situated in a chamber filled with fluid matching that of the stream to minimize refracting and reflecting interfaces. The detector array consists of 60 photodiodes each subtending 3 0 in scattering angle on 6 0 centers around 360 0 . 32 measurements on individual particles can be acquired at rates of 500 particles per second. The intensity and angular distribution of light scattered by spherical particles are indicative of size and relative refractive index. Calculations, using Lorenz--Mie theory, of differential scattering patterns integrated over angle corresponding to the detector geometry determined the instrument response to particle size. From this the expected resolution and experimental procedures are determined.Ultimately, the photometer will be utilized for identification and discrimination of biological cells based on the sensitivity of light scattering to size, shape, refractive index differences, internal granularity, and other internal morphology. This study has demonstrated the utility of the photometer and indicates potential for application to light scattering studies of biological cells

  5. Single-particle basis and translational invariance in microscopic nuclear calculations

    International Nuclear Information System (INIS)

    Ehfros, V.D.

    1977-01-01

    The approach to the few-body problem is considered which allows to use the simple single-particle basis without violation of the translation invariance. A method is proposed to solve the nuclear reaction problems in the single-particle basis. The method satisfies the Pauli principle and the translation invariance. Calculation of the matrix elements of operators is treated

  6. Handbook of particle detection and imaging

    CERN Document Server

    Buvat, Irène

    2012-01-01

    The handbook centers on detection techniques in the field of particle physics, medical imaging and related subjects. It is structured into three parts. The first one is dealing with basic ideas of particle detectors, followed by applications of these devices in high energy physics and other fields. In the last part the large field of medical imaging using similar detection techniques is described. The different chapters of the book are written by world experts in their field. Clear instructions on the detection techniques and principles in terms of relevant operation parameters for scientists and graduate students are given.Detailed tables and diagrams will make this a very useful handbook for the application of these techniques in many different fields like physics, medicine, biology and other areas of natural science.

  7. Handbook of particle detection and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Grupen, Claus [Siegen Univ. (Germany). Fachbereich 7 - Physik; Buvat, Irene (eds.) [Paris 7 et 11 Univ., Orsay (France). IMNC-UMR 8165 CNRS

    2012-07-01

    The handbook centers on detection techniques in the field of particle physics, medical imaging and related subjects. It is structured into three parts. The first one is dealing with basic ideas of particle detectors, followed by applications of these devices in high energy physics and other fields. In the last part the large field of medical imaging using similar detection techniques is described. The different chapters of the book are written by world experts in their field. Clear instructions on the detection techniques and principles in terms of relevant operation parameters for scientists and graduate students are given. Detailed tables and diagrams will make this a very useful handbook for the application of these techniques in many different fields like physics, medicine, biology and other areas of natural science. (orig.)

  8. Factors Influencing the Ignition and Burnout of a Single Biomass Particle

    DEFF Research Database (Denmark)

    Momenikouchaksaraei, Maryam; Kær, Søren Knudsen; Yin, Chungen

    2011-01-01

    Ignition and burnout of a single biomass particle were studied numerically. A one-dimensional particle combustion model was developed which is capable to simulate all the intraparticle conversion processes (drying, recondensation, devolatilization, char gasification/oxidation and heat/mass/moment......Ignition and burnout of a single biomass particle were studied numerically. A one-dimensional particle combustion model was developed which is capable to simulate all the intraparticle conversion processes (drying, recondensation, devolatilization, char gasification/oxidation and heat...... concentration were not very significant. The influences of these factors on particle burnout were much more remarkable than ignition behaviour....

  9. Two-Way Communication with a Single Quantum Particle

    Science.gov (United States)

    Del Santo, Flavio; Dakić, Borivoje

    2018-02-01

    In this Letter we show that communication when restricted to a single information carrier (i.e., single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass this limitation. We show that communication bounded to the exchange of a single quantum particle (in superposition of different spatial locations) can result in "two-way signaling," which is impossible in classical physics. We quantify the discrepancy between classical and quantum scenarios by the probability of winning a game played by distant players. We generalize our result to an arbitrary number of parties and we show that the probability of success is asymptotically decreasing to zero as the number of parties grows, for all classical strategies. In contrast, quantum strategy allows players to win the game with certainty.

  10. Snow particles extracted from X-ray computed microtomography imagery and their single-scattering properties

    Science.gov (United States)

    Ishimoto, Hiroshi; Adachi, Satoru; Yamaguchi, Satoru; Tanikawa, Tomonori; Aoki, Teruo; Masuda, Kazuhiko

    2018-04-01

    Sizes and shapes of snow particles were determined from X-ray computed microtomography (micro-CT) images, and their single-scattering properties were calculated at visible and near-infrared wavelengths using a Geometrical Optics Method (GOM). We analyzed seven snow samples including fresh and aged artificial snow and natural snow obtained from field samples. Individual snow particles were numerically extracted, and the shape of each snow particle was defined by applying a rendering method. The size distribution and specific surface area distribution were estimated from the geometrical properties of the snow particles, and an effective particle radius was derived for each snow sample. The GOM calculations at wavelengths of 0.532 and 1.242 μm revealed that the realistic snow particles had similar scattering phase functions as those of previously modeled irregular shaped particles. Furthermore, distinct dendritic particles had a characteristic scattering phase function and asymmetry factor. The single-scattering properties of particles of effective radius reff were compared with the size-averaged single-scattering properties. We found that the particles of reff could be used as representative particles for calculating the average single-scattering properties of the snow. Furthermore, the single-scattering properties of the micro-CT particles were compared to those of particle shape models using our current snow retrieval algorithm. For the single-scattering phase function, the results of the micro-CT particles were consistent with those of a conceptual two-shape model. However, the particle size dependence differed for the single-scattering albedo and asymmetry factor.

  11. On the simultaneous deployment of two single-particle mass spectrometers at an urban background and a roadside site during SAPUSS

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2016-08-01

    Full Text Available The aerosol time-of-flight mass spectrometer (ATOFMS provides size-resolved information on the chemical composition of single particles with high time resolution. Within SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, continuous ATOFMS measurements of ambient particles were made simultaneously at two urban locations: urban background (UB site and roadside (RS site in the city of Barcelona (Spain from 17 September to 18 October 2010. Two different instrumental configurations were used: ATOFMS (TSI 3800 with a converging nozzle inlet (high efficiency at about 800–2000 nm at the UB site and ATOFMS (TSI 3800-100 with an aerodynamic lens inlet (high efficiency at about 300–700 nm at the RS site. This is the first time, to our knowledge, that two ATOFMS instruments have been deployed in the same field study. The different instrument configurations had an impact on the observed particle types at the two sites. Nevertheless, 10 particle types were detected at both locations, including local and regional elemental carbon (22.7–58.9 % of total particles, fresh and aged sea salt (1.0–14.6 %, local and regional nitrate-containing aerosols (3–11.6 %, local lead-containing metallic particles (0.1–0.2 %, and transported Fe-nitrate particles (0.8–2.5 %. The ATOFMS at the UB also characterized four particle types: calcium-containing dust (0.9 %, Saharan dust (1.3 %, vanadium-containing particles (0.9 %, and vegetative debris (1.7 %. By contrast, the high statistical counts of fine particles detected at the RS allowed identification of eight particle types. Four of these contained organic nitrogen of primary and secondary origin, which highlights the complex nature of the sources and processes that contribute to this aerosol chemical component. Aminium salts were found related to coarse sulfate-rich particle types, suggesting heterogeneous reaction mechanisms for their formation. The other four particle

  12. Mass spectra features of biomass burning boiler and coal burning boiler emitted particles by single particle aerosol mass spectrometer.

    Science.gov (United States)

    Xu, Jiao; Li, Mei; Shi, Guoliang; Wang, Haiting; Ma, Xian; Wu, Jianhui; Shi, Xurong; Feng, Yinchang

    2017-11-15

    In this study, single particle mass spectra signatures of both coal burning boiler and biomass burning boiler emitted particles were studied. Particle samples were suspended in clean Resuspension Chamber, and analyzed by ELPI and SPAMS simultaneously. The size distribution of BBB (biomass burning boiler sample) and CBB (coal burning boiler sample) are different, as BBB peaks at smaller size, and CBB peaks at larger size. Mass spectra signatures of two samples were studied by analyzing the average mass spectrum of each particle cluster extracted by ART-2a in different size ranges. In conclusion, BBB sample mostly consists of OC and EC containing particles, and a small fraction of K-rich particles in the size range of 0.2-0.5μm. In 0.5-1.0μm, BBB sample consists of EC, OC, K-rich and Al_Silicate containing particles; CBB sample consists of EC, ECOC containing particles, while Al_Silicate (including Al_Ca_Ti_Silicate, Al_Ti_Silicate, Al_Silicate) containing particles got higher fractions as size increase. The similarity of single particle mass spectrum signatures between two samples were studied by analyzing the dot product, results indicated that part of the single particle mass spectra of two samples in the same size range are similar, which bring challenge to the future source apportionment activity by using single particle aerosol mass spectrometer. Results of this study will provide physicochemical information of important sources which contribute to particle pollution, and will support source apportionment activities. Copyright © 2017. Published by Elsevier B.V.

  13. Investigation of the single Particle Structure of the neutron-rich Sodium Isotopes $^{27-31}\\!$Na

    CERN Document Server

    2002-01-01

    We propose to study the single particle structure of the neutron-rich isotopes $^{27-31}\\!$Na. These isotopes will be investigated via neutron pickup reactions in inverse kinematics on a deuterium and a beryllium target. Scattered beam particles and transfer products are detected in a position sensitive detector located around 0$^\\circ$. De-excitation $\\gamma$-rays emitted after an excited state has been populated will be registered by the MINIBALL Germanium array. The results will shed new light on the structure of the neutron-rich sodium isotopes and especially on the region of strong deformation around the N=20 nucleus $^{31}\\!$Na.

  14. A multi-parametric particle-pairing algorithm for particle tracking in single and multiphase flows

    International Nuclear Information System (INIS)

    Cardwell, Nicholas D; Vlachos, Pavlos P; Thole, Karen A

    2011-01-01

    Multiphase flows (MPFs) offer a rich area of fundamental study with many practical applications. Examples of such flows range from the ingestion of foreign particulates in gas turbines to transport of particles within the human body. Experimental investigation of MPFs, however, is challenging, and requires techniques that simultaneously resolve both the carrier and discrete phases present in the flowfield. This paper presents a new multi-parametric particle-pairing algorithm for particle tracking velocimetry (MP3-PTV) in MPFs. MP3-PTV improves upon previous particle tracking algorithms by employing a novel variable pair-matching algorithm which utilizes displacement preconditioning in combination with estimated particle size and intensity to more effectively and accurately match particle pairs between successive images. To improve the method's efficiency, a new particle identification and segmentation routine was also developed. Validation of the new method was initially performed on two artificial data sets: a traditional single-phase flow published by the Visualization Society of Japan (VSJ) and an in-house generated MPF data set having a bi-modal distribution of particles diameters. Metrics of the measurement yield, reliability and overall tracking efficiency were used for method comparison. On the VSJ data set, the newly presented segmentation routine delivered a twofold improvement in identifying particles when compared to other published methods. For the simulated MPF data set, measurement efficiency of the carrier phases improved from 9% to 41% for MP3-PTV as compared to a traditional hybrid PTV. When employed on experimental data of a gas–solid flow, the MP3-PTV effectively identified the two particle populations and reported a vector efficiency and velocity measurement error comparable to measurements for the single-phase flow images. Simultaneous measurement of the dispersed particle and the carrier flowfield velocities allowed for the calculation of

  15. Deposition and detection of particles during integrated circuit manufacturing

    NARCIS (Netherlands)

    Wali, F.; Knotter, D. Martin; Kelly, John J.; Kuper, F.G.

    2006-01-01

    Abstract—Deposition mechanism of silica particles on silicon wafers was investigated by depositing specially prepared mono-dispersed particles (mean diameter = 330 nm). To measure particles of the size below the detection limit of our particle measurement tools, silica particles with luminance core

  16. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and

  17. The measurement of single particle temperature in plasma sprays

    International Nuclear Information System (INIS)

    Fincke, J.R.; Swank, W.D.; Bolsaitis, P.P.; Elliott, J.F.

    1990-01-01

    A measurement technique for simultaneously obtaining the size, velocity, temperature, and relative number density of particles entrained in high temperature flow fields is described. In determining the particle temperature from a two-color pyrometery technique, assumptions about the relative spectral emissivity of the particle are required. For situations in which the particle surface undergoes chemical reactions the assumption of grey body behavior is shown to introduce large Temperature measurement uncertainties. Results from isolated, laser heated, single particle measurements and in-flight data from the plasma spraying of WC-Co are presented. 10 refs., 5 figs

  18. Isolation of Single-Domain Antibody Fragments That Preferentially Detect Intact (146S Particles of Foot-and-Mouth Disease Virus for Use in Vaccine Quality Control

    Directory of Open Access Journals (Sweden)

    Michiel M. Harmsen

    2017-08-01

    Full Text Available Intact (146S foot-and-mouth disease virus (FMDVs can dissociate into specific (12S viral capsid degradation products. FMD vaccines normally consist of inactivated virions. Vaccine quality is dependent on 146S virus particles rather than 12S particles. We earlier isolated two llama single-domain antibody fragments (VHHs that specifically recognize 146S particles of FMDV strain O1 Manisa and shown their potential use in quality control of FMD vaccines during manufacturing. These 146S-specific VHHs were specific for particular O serotype strains and did not bind strains from other FMDV serotypes. Here, we describe the isolation of 146S-specific VHHs against FMDV SAT2 and Asia 1 strains by phage display selection from llama immune libraries. VHHs that bind both 12S and 146S particles were readily isolated but VHHs that bind specifically to 146S particles could only be isolated by phage display selection using prior depletion for 12S particles. We obtained one 146S-specific VHH—M332F—that binds to strain Asia 1 Shamir and several VHHs that preferentially bind 146S particles of SAT2 strain SAU/2/00, from which we selected VHH M379F for further characterization. Both M332F and M379F did not bind FMDV strains from other serotypes. In a sandwich enzyme-linked immunosorbent assay (ELISA employing unlabeled and biotinylated versions of the same VHH M332F showed high specificity for 146S particles but M379F showed lower 146S-specificity with some cross-reaction with 12S particles. These ELISAs could detect 146S particle concentrations as low as 2.3–4.6 µg/l. They can be used for FMD vaccine quality control and research and development, for example, to identify virion stabilizing excipients.

  19. Intracellular formation of α-synuclein oligomers and the effect of heat shock protein 70 characterized by confocal single particle spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Johannes [Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); German Center for Neurodegenerative Diseases – DZNE, Site Munich, Feodor-Lynen-Str. 17, 81377 Munich (Germany); Hillmer, Andreas S. [Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Feodor-Lynen-Str. 23, 81377 Munich (Germany); Högen, Tobias [Department of Neurology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); McLean, Pamela J. [Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 (United States); Giese, Armin, E-mail: armin.giese@med.uni-muenchen.de [Center for Neuropathology and Prion Research, Ludwig-Maximilians-University, Feodor-Lynen-Str. 23, 81377 Munich (Germany)

    2016-08-12

    Synucleinopathies such as dementia with Lewy bodies or Parkinson’s disease are characterized by intracellular deposition of pathologically aggregated α-synuclein. The details of the molecular pathogenesis of PD and especially the conditions that lead to intracellular aggregation of α-synuclein and the role of these aggregates in cell death remain unknown. In cell free in vitro systems considerable knowledge about the aggregation processes has been gathered. In comparison, the knowledge about these aggregation processes in cells is far behind. In cells α-synuclein aggregates can be toxic. However, the crucial particle species responsible for decisive steps in pathogenesis such as seeding a continuing aggregation process and triggering cell death remain to be identified. In order to understand the complex nature of intracellular α-synuclein aggregate formation, we analyzed fluorescent particles formed by venus and α-synuclein-venus fusion proteins and α-synuclein-hemi-venus fusion proteins derived from gently lyzed cells. With these techniques we were able to identify and characterize α-synuclein oligomers formed in cells. Especially the use of α-synuclein-hemi-venus fusion proteins enabled us to identify very small α-synuclein oligomers with high sensitivity. Furthermore, we were able to study the molecular effect of heat shock protein 70, which is known to inhibit α-synuclein aggregation in cells. Heat shock protein 70 does not only influence the size of α-synuclein oligomers, but also their quantity. In summary, this approach based on fluorescence single particle spectroscopy, that is suited for high throughput measurements, can be used to detect and characterize intracellularly formed α-synuclein aggregates and characterize the effect of molecules that interfere with α-synuclein aggregate formation. - Highlights: • Single particle spectroscopy detects intracellular formed α-synuclein aggregates. • Fusion proteins allow detection of protein

  20. Tagged particle in single-file diffusion with arbitrary initial conditions

    Science.gov (United States)

    Cividini, J.; Kundu, A.

    2017-08-01

    We compute the full probability distribution of the positions of a tagged particle exactly for the given arbitrary initial positions of the particles, and for general single-particle propagators. We consider the thermodynamic limit of our exact expressions in quenched and annealed settings. For a particular class of single-particle propagators, the exact formula is expressed in a simple integral form in the quenched case whereas in the annealed case, it is expressed as a simple combination of Bessel functions. In particular, we focus on the step and the power-law initial configurations. In the former case, a drift is induced even when the one-particle propagators are symmetric. On the other hand, in the later case the scaling of the cumulants of the position of the tracer differs from the uniform case. We provide numerical verifications of our results.

  1. Tomograms and the quest for single particle nonlocality

    International Nuclear Information System (INIS)

    Anisimov, M A; Caponigro, M; Mancini, S; Man'ko, V I

    2007-01-01

    By using a tomographic approach to quantum states, we rise the problem of nonlocality within a single particle (single degree of freedom). We propose a possible way to look for such effects on a qubit. Although a conclusive answer is far from being reached, we provide some reflections on the foundational ground

  2. Meta-material for nuclear particle detection

    Science.gov (United States)

    Merlo, V.; Salvato, M.; Lucci, M.; Ottaviani, I.; Cirillo, M.; Scherillo, A.; Schooneveld, E. M.; Vannozzi, A.; Celentano, G.; Pietropaolo, A.

    2017-02-01

    Superconducting strips coated with boron were engineered with a view to subnuclear particle detection. Combining the characteristics of boron as a generator of α-particles (as a consequence of neutron absorption) and the ability of superconducting strips to act as resistive switches, it is shown that fabricated Nb-boron and NbN-boron strips represent a promising basis for implementing neutron detection devices. In particular, the superconducting transition of boron-coated NbN strips generates voltage outputs of the order of a few volts thanks to the relatively higher normal state resitivity of NbN with respect to Nb. This result, combined with the relatively high transition temperature of NbN (of the order of 16 K for the bulk material), is an appealing prospect for future developments. The coated strips are meta-devices since their constituting material does not exist in nature and it is engineered to accomplish a specific task, i.e. generate an output voltage signal upon α-particle irradiation.

  3. Single-particle motion in rapidly rotating nuclei

    International Nuclear Information System (INIS)

    Bengtsson, R.; Frisk, H.

    1985-01-01

    The motion of particles belonging to a single-j shell is described in terms of classical orbitals. The effects of rapid rotation and pairing correlations are discussed and the results are compared with the quantum mechanical orbitals. (orig.)

  4. Strong reduction of spectral heterogeneity in gold bipyramids for single-particle and single-molecule plasmon sensing.

    Science.gov (United States)

    Peters, S M E; Verheijen, M A; Prins, M W J; Zijlstra, P

    2016-01-15

    Single metal nanoparticles are attractive biomolecular sensors. Binding of analyte to a functional particle results in a plasmon shift that can be conveniently monitored in a far-field optical microscope. Heterogeneities in spectral properties of individual particles in an ensemble affect the reliability of a single-particle plasmon sensor, especially when plasmon shifts are monitored in real-time using a fixed irradiation wavelength. We compare the spectral heterogeneity of different plasmon sensor geometries (gold nanospheres, nanorods, and bipyramids) and correlate this to their size and aspect-ratio dispersion. We show that gold bipyramids exhibit a strongly reduced heterogeneity in aspect ratio and plasmon wavelength compared to commonly used gold nanorods. We show that this translates into a significantly improved homogeneity of the response to molecular binding without compromising single-molecule sensitivity.

  5. Picosecond optical shutter for particle detection

    International Nuclear Information System (INIS)

    Fan, B.; Gee, C.M.; Shapiro, G.

    1975-04-01

    Characteristics of an optical shutter utilizing Kerr effect induced by picosecond laser pulses in carbon disulfide are studied experimentally. The shutter has a gate time of 4.5 to 5 ps full width at half-maximum and a transmission of approximately 15 percent at a wavelength 0.53 μm. Such an ultrafast shutter can be used as an optical signal gate in a sampling detection scheme that has picosecond time-resolution. The picosecond optical detection scheme is envisioned to have applications in experimental high-energy physics such as to time-resolve ultrashort Cherenkov or synchrotron radiation emitted by relativistic particles. Methods of synchronizing a laser-activated Kerr shutter with a particle accelerator or synchrotron are discussed

  6. Biosensing Using Magnetic Particle Detection Techniques

    Directory of Open Access Journals (Sweden)

    Yi-Ting Chen

    2017-10-01

    Full Text Available Magnetic particles are widely used as signal labels in a variety of biological sensing applications, such as molecular detection and related strategies that rely on ligand-receptor binding. In this review, we explore the fundamental concepts involved in designing magnetic particles for biosensing applications and the techniques used to detect them. First, we briefly describe the magnetic properties that are important for bio-sensing applications and highlight the associated key parameters (such as the starting materials, size, functionalization methods, and bio-conjugation strategies. Subsequently, we focus on magnetic sensing applications that utilize several types of magnetic detection techniques: spintronic sensors, nuclear magnetic resonance (NMR sensors, superconducting quantum interference devices (SQUIDs, sensors based on the atomic magnetometer (AM, and others. From the studies reported, we note that the size of the MPs is one of the most important factors in choosing a sensing technique.

  7. Physical and chemical study of single aerosol particles using optical trapping cavity ringdown spectroscopy

    Science.gov (United States)

    2016-08-30

    scope that views the trapped particle walking through the ringdown beam step by step. (b) An image that shows the traces of the particle (MWCNT... walking through the RD beam . 5 a b c Fig.3 The OT-CRDS single particle scope views oscillations of a trapped particle. (a) Image of a trapped...and walking single carbon- nanotube particles of ?50 µm in size and viewing those properties via changes of ringdown time. This single- aerosol

  8. New instrument for tribocharge measurement due to single particle impacts

    International Nuclear Information System (INIS)

    Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Ding Yulong; Pitt, Kendal G.

    2007-01-01

    During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10 fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as ∼100 μm impacting on the target at different incident angles with a velocity up to about 80 m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact

  9. Influence of Torrefaction on Single Particle Combustion of Wood

    DEFF Research Database (Denmark)

    Lu, Zhimin; Jian, Jie; Jensen, Peter Arendt

    2016-01-01

    This study focuses on the influence of torrefaction on the char reactivity, char yield, and combustion time of 3-5 mm spherical wood particles in a single particle combustion reactor (SPC) operating at a nominal temperature of 1231 °C. The devolatilization times were reduced and the char burnout...

  10. Pairing fluctuation effects on the single-particle spectra for the superconducting state

    International Nuclear Information System (INIS)

    Pieri, P.; Pisani, L.; Strinati, G.C.

    2004-01-01

    Single-particle spectra are calculated in the superconducting state for a fermionic system with an attractive interaction, as functions of temperature and coupling strength from weak to strong. The fermionic system is described by a single-particle self-energy that includes pairing-fluctuation effects in the superconducting state. The theory reduces to the ordinary BCS approximation in weak coupling and to the Bogoliubov approximation for the composite bosons in strong coupling. Several features of the single-particle spectral function are shown to compare favorably with experimental data for cuprate superconductors

  11. A transient single particle model under FCI conditions

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Yan; SHANG Zhi; XU Ji-Jun

    2005-01-01

    The paper is focused on the coupling effect between film boiling heat transfer and evaporation drag around a hot-particle in cold liquid. Based on the continuity, momentum and energy equations of the vapor film, a transient two-dimensional single particle model has been established. This paper contains a detailed description of HPMC (High-temperature Particle Moving in Coolant) model for studying some aspects of the premixing stage of fuel-coolant interactions (FCIs). The transient process of high-temperature particles moving in coolant can be simulated. Comparisons between the experiment results and the calculations using HPMC model demonstrate that HPMC model achieves a good agreement in predicting the time-varying characteristic of high-temperature spheres moving in coolant.

  12. A superconducting microcalorimeter for low-flux detection of near-infrared single photons

    International Nuclear Information System (INIS)

    Dreyling-Eschweiler, Jan

    2014-07-01

    This thesis covers the development and the characterization of a single photon detector based on a superconducting microcalorimeter. The detector development is motivated by the Any Light Particle Search II (ALPS II) experiment at DESY in Hamburg, which searches for weakly interacting sub-eV particles (WISPs). Therefore, a detection of low-fluxes of 1064 nm light is required. The work is divided in three analyses: the characterization of a milli-kelvin (mK) cryostat, the characterization of superconducting sensors for single photon detection, and the determination of dark count rates concerning 1064 nm signals. Firstly, an adiabatic demagnetization refrigerator (ADR) is characterized, which allows to reach mK-temperatures. During commissioning, the ADR cryostat is optimized and prepared to stably cool superconducting sensors at 80 mK±25 μK. It is found that sensors can be continuously operated for ∝20 h before recharging the system in -4 s -1 . By operating a fiber-coupled TES, it is found that the dark count rate for 1064 nm signals is dominated by pile-up events of near-infrared thermal photons coming through the fiber from the warm environment. Considering a detection efficiency of ∝18 %, a dark count rate of 8.6 . 10 -3 s -1 is determined for 1064 nm ALPS photons.Concerning ALPS II, this results in a sensitivity gain compared to the ALPS I detector. Furthermore, this thesis is the starting point of TES detector development in Hamburg, Germany.

  13. Optimization of magnetic switches for single particle and cell transport

    Energy Technology Data Exchange (ETDEWEB)

    Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, North Carolina 27708 (United States); Joint Institute, University of Michigan—Shanghai Jiao Tong University, Shanghai Jiao Tong University, Shanghai 200240 (China); Murdoch, David M. [Department of Medicine, Duke University, Durham, North Carolina 27708 (United States); Kim, CheolGi [Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of)

    2014-06-28

    The ability to manipulate an ensemble of single particles and cells is a key aim of lab-on-a-chip research; however, the control mechanisms must be optimized for minimal power consumption to enable future large-scale implementation. Recently, we demonstrated a matter transport platform, which uses overlaid patterns of magnetic films and metallic current lines to control magnetic particles and magnetic-nanoparticle-labeled cells; however, we have made no prior attempts to optimize the device geometry and power consumption. Here, we provide an optimization analysis of particle-switching devices based on stochastic variation in the particle's size and magnetic content. These results are immediately applicable to the design of robust, multiplexed platforms capable of transporting, sorting, and storing single cells in large arrays with low power and high efficiency.

  14. Emissions from Ethanol-Gasoline Blends: A Single Particle Perspective

    Directory of Open Access Journals (Sweden)

    Peter H. McMurry

    2011-06-01

    Full Text Available Due to its agricultural origin and function as a fuel oxygenate, ethanol is being promoted as an alternative biomass-based fuel for use in spark ignition engines, with mandates for its use at state and regional levels. While it has been established that the addition of ethanol to a fuel reduces the particulate mass concentration in the exhaust, little attention has been paid to changes in the physicochemical properties of the emitted particles. In this work, a dynamometer-mounted GM Quad-4 spark ignition engine run without aftertreatment at 1,500 RPM and 100% load was used with four different fuel blends, containing 0, 20, 40 and 85 percent ethanol in gasoline. This allowed the effects of the fuel composition to be isolated from other effects. Instrumentation employed included two Aerosol Time-of-Flight Mass Spectrometers covering different size ranges for analysis of single particle composition, an Aethalometer for black carbon, a Scanning Mobility Particle Sizer for particle size distributions, a Photoelectric Aerosol Sensor for particle-bound polycyclic aromatic hydrocarbon (PAH species and gravimetric filter measurements for particulate mass concentrations. It was found that, under the conditions investigated here, additional ethanol content in the fuel changes the particle size distribution, especially in the accumulation mode, and decreases the black carbon and total particulate mass concentrations. The molecular weight distribution of the PAHs was found to decrease with added ethanol. However, PAHs produced from higher ethanol-content fuels are associated with NO2− (m/z—46 in the single-particle mass spectra, indicating the presence of nitro-PAHs. Compounds associated with the gasoline (e.g., sulfur-containing species are diminished due to dilution as ethanol is added to the fuel relative to those associated with the lubricating oil (e.g., calcium, zinc, phosphate in the single particle spectra. These changes have potential

  15. Studies of the neutron single-particle structure of exotic nuclei at the HRIBF

    International Nuclear Information System (INIS)

    Thomas, J.S.; Bardayan, D.W.; Blackmon, J.C.; Cizewski, J.A.; Greife, U.; Gross, C.J.; Johnson, M.S.; Jones, K.L.; Kozub, R.L.; Liang, J.F.; Livesay, R.J.; Ma, Z.; Moazen, B.H.; Nesaraja, C.D.; Shapira, D.; Smith, M.S.

    2004-01-01

    The study of neutron single-particle strengths in neutron-rich nuclei is of interest for nuclear structure and nuclear astrophysics. The distribution of single-particle strengths constrains the effective Hamiltonian and pairing interactions and determines neutron interaction rates that are crucial for understanding the synthesis of heavy nuclei in supernovae via the rapid neutron capture process. Particularly important are the neutron single-particle levels in nuclei near closed neutron shells. Radioactive ion beams from the Holifield Radioactive Ion Beam Facility have been used to study (d,p) reactions in inverse kinematics in order to probe neutron single-particle states in exotic nuclei. The results of a measurement with a 82 Ge beam will be presented

  16. Detection of charged particles through a photodiode: design and analysis

    International Nuclear Information System (INIS)

    Angoli, A.; Quirino, L.L.; Hernandez, V.M.; Lopez del R, H.; Mireles, F.; Davila, J.I.; Rios, C.; Pinedo, J.L.

    2006-01-01

    This project develops and construct an charge particle detector mean a pin photodiode array, design and analysis using a silicon pin Fotodiodo that generally is used to detect visible light, its good efficiency, size compact and reduced cost specifically allows to its use in the radiation monitoring and alpha particle detection. Here, so much, appears the design of the system of detection like its characterization for alpha particles where one is reported as alpha energy resolution and detection efficiency. The equipment used in the development of work consists of alpha particle a triple source composed of Am-241, Pu-239 and Cm-244 with 5,55 KBq as total activity, Maestro 32 software made by ORTEC, a multi-channel card Triumph from ORTEC and one low activity electroplated uranium sample. (Author)

  17. Ultrafast detection in particle physics and positron emission tomography using SiPMs

    Science.gov (United States)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2017-12-01

    Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

  18. Single-particle behaviour in circulating fluidized beds

    DEFF Research Database (Denmark)

    Erik Weinell, Claus; Dam-Johansen, Kim; Johnsson, Jan Erik

    1997-01-01

    This paper describes an experimental investigation of single-particle behaviour in a cold pilot-scale model of a circulating fluidized bed combustor (CFBC). In the system, sand is recirculated by means of air. Pressure measurements along the riser are used to determine the suspension density...

  19. DAMPING OF UNBOUND SINGLE-PARTICLE MODES

    NARCIS (Netherlands)

    FORTIER, S; BEAUMEL, D; GALES, S; GUILLOT, J; LANGEVINJOLIOT, H; LAURENT, H; MAISON, JM; BORDEWIJK, J; BRANDENBURG, S; KRASZNAHORKAY, A; CRAWLEY, GM; MASSOLO, CP; RENTERIA, M; KHENDRICHE, A

    1995-01-01

    The (alpha, He-3-n) reaction has been investigated at 120 MeV incident energy on Ni-64, Zr-90, and Sn-120 target nuclei. Neutrons in coincidence with He-3 particles emitted at 0 degrees were detected using the multidetector array EDEN, in order to get information about the decay of the

  20. Electrostatic deposition of a micro solder particle using a single probe by applying a single rectangular pulse

    International Nuclear Information System (INIS)

    Nakabayashi, Daizo; Sawai, Kenji; Saito, Shigeki; Takahashi, Kunio

    2012-01-01

    Recently, micromanipulation techniques have been in high demand. A technique to deposit a metal microparticle onto a metal substrate by using a single metal probe has been proposed as one of the techniques. A solder particle with a diameter of 20–30 µm, initially adhering to the probe tip, is detached and deposited onto a substrate. The success rate of the particle deposition was 44% in the previous research, and is insufficient for industrial applications. In this paper, a technique of particle deposition by applying a single rectangular pulse is proposed, and the mechanism of the deposition is described. In the mechanism, an electric discharge between the probe and the particle when the particle reaches the substrate plays an important role in the particle deposition. Moreover, the mechanism of the proposed technique is verified by experiments of particle deposition, which are observed using a high-speed camera, a scanning electron microscope (SEM) and an oscilloscope. The success rate of the particle deposition has increased to 93% by the proposed technique. Furthermore, the damage to the particle by the electric discharge is evaluated using an RC circuit model, and the applicability of the proposed technique is discussed. (paper)

  1. Advances in associated-particle sealed-tube neutron probe diagnostics for substance detection

    International Nuclear Information System (INIS)

    Rhodes, E.; Dickerman, C.E.; Frey, M.

    1995-01-01

    The development and investigation of a small associated-particle sealed-tube neutron generator (APSTNG) shows potential to allow the associated-particle diagnostic method to be moved out of the laboratory into field applications. The APSTNG interrogates the inspected object with 14-MeV neutrons generated from the deuterium-tritium reaction and detects the alpha-particle associated with each neutron inside a cone encompassing the region of interest. Gamma-ray spectra of resulting neutron reactions identify many nuclides. Flight-times determined from detection times of the gamma-rays and alpha-particles can yield a separate coarse tomographic image of each identified nuclide, from a single orientation. Chemical substances are identified by comparing relative spectral line intensities with ratios of elements in reference compounds. The high-energy neutrons and gamma-rays penetrate large objects and dense materials. Generally no collimators or radiation shielding are needed. Proof-of-concept laboratory experiments have been successfully performed for simulated nuclear, chemical warfare, and conventional munitions. Most recently, inspection applications have been investigated for radioactive waste characterization, presence of cocaine in propane tanks, and uranium and plutonium smuggling. Based on lessons learned with the present APSTNG system, an advanced APSTNG tube (along with improved high voltage supply and control units) is being designed and fabricated that will be transportable and rugged, yield a substantial neutron output increase, and provide sufficiently improved lifetime to allow operation at more than an order of magnitude increase in neutron flux

  2. Single particle train ordering in microchannel based on inertial and vortex effects

    Science.gov (United States)

    Fan, Liang-Liang; Yan, Qing; Zhe, Jiang; Zhao, Liang

    2018-06-01

    A new microfluidic device for microparticle focusing and ordering in a single particle train is reported. The particle focusing and ordering are based on inertial and vortex effects in a microchannel with a series of suddenly contracted and widely expanded structures on one side. In the suddenly contracted regions, particles located near the contracted structures are subjected to a strong wall-effect lift force and momentum-change-induced inertial force due to the highly curved trajectory, migrating to the straight wall. A horizontal vortex is generated downstream of the contracted structure, which prevents the particle from getting close to the wall. In the widely expanded regions, the streamline is curved and no vortex is generated. The shear-gradient lift force and the momentum-change-induced inertial force are dominant for particle lateral migration, driving particles towards the wall of the expanded structures. Eventually, particles are focused and ordered in a single particle train by the combination effects of the inertial forces and the vortex. In comparison with other single-stream particle focusing methods, this device requires no sheath flow, is easy for fabrication and operation, and can work over a wide range of Reynolds numbers from 19.1–142.9. The highly ordered particle chain could be potentially utilized in a variety of lab-chip applications, including micro-flow cytometer, imaging and droplet-based cell entrapment.

  3. Single-particle energies and density of states in density functional theory

    Science.gov (United States)

    van Aggelen, H.; Chan, G. K.-L.

    2015-07-01

    Time-dependent density functional theory (TD-DFT) is commonly used as the foundation to obtain neutral excited states and transition weights in DFT, but does not allow direct access to density of states and single-particle energies, i.e. ionisation energies and electron affinities. Here we show that by extending TD-DFT to a superfluid formulation, which involves operators that break particle-number symmetry, we can obtain the density of states and single-particle energies from the poles of an appropriate superfluid response function. The standard Kohn- Sham eigenvalues emerge as the adiabatic limit of the superfluid response under the assumption that the exchange- correlation functional has no dependence on the superfluid density. The Kohn- Sham eigenvalues can thus be interpreted as approximations to the ionisation energies and electron affinities. Beyond this approximation, the formalism provides an incentive for creating a new class of density functionals specifically targeted at accurate single-particle eigenvalues and bandgaps.

  4. A versatile optical microscope for time-dependent single-molecule and single-particle spectroscopy

    Science.gov (United States)

    Li, Hao; Yang, Haw

    2018-03-01

    This work reports the design and implementation of a multi-function optical microscope for time-dependent spectroscopy on single molecules and single nanoparticles. It integrates the now-routine single-object measurements into one standalone platform so that no reconfiguration is needed when switching between different types of sample or spectroscopy modes. The illumination modes include evanescent field through total internal reflection, dark-field illumination, and epi-excitation onto a diffraction-limited spot suitable for confocal detection. The detection modes include spectrally resolved line imaging, wide-field imaging with dual-color capability, and two-color single-element photon-counting detection. The switch between different spectroscopy and data acquisition modes is fully automated and executed through computer programming. The capability of this microscope is demonstrated through selected proof-of-principle experiments.

  5. A versatile optical microscope for time-dependent single-molecule and single-particle spectroscopy.

    Science.gov (United States)

    Li, Hao; Yang, Haw

    2018-03-28

    This work reports the design and implementation of a multi-function optical microscope for time-dependent spectroscopy on single molecules and single nanoparticles. It integrates the now-routine single-object measurements into one standalone platform so that no reconfiguration is needed when switching between different types of sample or spectroscopy modes. The illumination modes include evanescent field through total internal reflection, dark-field illumination, and epi-excitation onto a diffraction-limited spot suitable for confocal detection. The detection modes include spectrally resolved line imaging, wide-field imaging with dual-color capability, and two-color single-element photon-counting detection. The switch between different spectroscopy and data acquisition modes is fully automated and executed through computer programming. The capability of this microscope is demonstrated through selected proof-of-principle experiments.

  6. X-ray analysis of a single aerosol particle with combination of scanning electron microscope and synchrotron radiation X-ray microscope

    International Nuclear Information System (INIS)

    Toyoda, Masatoshi; Kaibuchi, Kazuki; Nagasono, Mitsuru; Terada, Yasuko; Tanabe, Teruo; Hayakawa, Shinjiro; Kawai, Jun

    2004-01-01

    We developed a microscope by a combination of synchrotron radiation X-ray fluorescence (SR-XRF) microscope and scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDX). SR-XRF is appropriate to detect trace and micro amount of elements and sensitive to heavy elements in an analyte but it cannot observe the real time image. SEM-EDX can observe the secondary electron image of a single particle in real time and is appropriate to detect lighter elements. This combination microscope can ensure the identification of the XRF spectrum to the SEM image without transferring the sample. For aerosol analysis, it is important to analyze each particle. The present method makes feasible to analyze not only the average elemental composition as the total particles but also elemental composition of each particle, which is dependent on the particle shape and size. The microscope was applied to an individual aerosol particle study. The X-ray spectra were different among the particles, but also different between SR-XRF and SEM-EDX for the same particle, due to the difference in fluorescence yields between X-ray excitation and electron excitation

  7. Statistical Methods for Single-Particle Electron Cryomicroscopy

    DEFF Research Database (Denmark)

    Jensen, Katrine Hommelhoff

    Electron cryomicroscopy (cryo-EM) is a form of transmission electron microscopy, aimed at reconstructing the 3D structure of a macromolecular complex from a large set of 2D projection images, as they exhibit a very low signal-to-noise ratio (SNR). In the single-particle reconstruction (SPR) probl...

  8. Expanding Single Particle Mass Spectrometer Analyses for the Identification of Microbe Signatures in Sea Spray Aerosol.

    Science.gov (United States)

    Sultana, Camille M; Al-Mashat, Hashim; Prather, Kimberly A

    2017-10-03

    Ocean-derived microbes in sea spray aersosol (SSA) have the potential to influence climate and weather by acting as ice nucleating particles in clouds. Single particle mass spectrometers (SPMSs), which generate in situ single particle composition data, are excellent tools for characterizing aerosols under changing environmental conditions as they can provide high temporal resolution and require no sample preparation. While SPMSs have proven capable of detecting microbes, these instruments have never been utilized to definitively identify aerosolized microbes in ambient sea spray aersosol. In this study, an aerosol time-of-flight mass spectrometer was used to analyze laboratory generated SSA produced from natural seawater in a marine aerosol reference tank. We present the first description of a population of biological SSA mass spectra (BioSS), which closely match the ion signatures observed in previous terrestrial microbe studies. The fraction of BioSS dramatically increased in the largest supermicron particles, consistent with field and laboratory measurements of microbes ejected by bubble bursting, further supporting the assignment of BioSS mass spectra as microbes. Finally, as supported by analysis of inorganic ion signals, we propose that dry BioSS particles have heterogeneous structures, with microbes adhered to sodium chloride nodules surrounded by magnesium-enriched coatings. Consistent with this structure, chlorine-containing ion markers were ubiquitous in BioSS spectra and identified as possible tracers for distinguishing recently aerosolized marine from terrestrial microbes.

  9. Detection of tire tread particles using laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prochazka, David, E-mail: prochazka.d@fme.vutbr.cz [Brno University of Technology, Institute of Physical Engineering, Technická 2, 616 00 Brno (Czech Republic); Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Bilík, Martin [Brno University of Technology, Institute of Forensic Engineering, Údolní 244/53, 602 00 Brno (Czech Republic); Prochazková, Petra [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Klus, Jakub; Pořízka, Pavel; Novotný, Jan [Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Novotný, Karel [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Ticová, Barbora [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Bradáč, Albert; Semela, Marek [Brno University of Technology, Institute of Forensic Engineering, Údolní 244/53, 602 00 Brno (Czech Republic); and others

    2015-06-01

    The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire. - Highlights: • LIBS experimental measurement parameters for tire tread particles were optimize. • Calibration curve was prepared. • Limit of detection was determined.

  10. Detection of tire tread particles using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek

    2015-01-01

    The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire. - Highlights: • LIBS experimental measurement parameters for tire tread particles were optimize. • Calibration curve was prepared. • Limit of detection was determined

  11. Heterogeneous reactivity of sea spray particles during the CalNex field campaign: Insight from single particle measurements and correlations with gas phase measurements

    Science.gov (United States)

    Gaston, C. J.; Riedel, T. P.; Thornton, J. A.; Wagner, N.; Brown, S. S.; Quinn, P.; Bates, T. S.; Prather, K. A.

    2011-12-01

    Sea spray particles are ubiquitous in marine environments. Heterogeneous reactions between sea spray particles and gas phase pollutants, such as HNO3(g), and N2O5(g), alter particle composition by displacing particulate phase halogens in sea spray and releasing these halogen species into the gas phase; these halogen-containing gas phase species play a significant role in tropospheric ozone production. Measurements of both gas phase and particle phase species on board the R/V Atlantis during the CalNEX 2010 field campaign provided an opportunity to examine the impact of heterogeneous reactivity of marine aerosols along the California coast. During the cruise, coastal measurements were made near the Santa Monica and Port of Los Angeles regions to monitor the chemical processing of marine aerosols. Sea spray particles were analyzed since these particles were the major chloride-containing particles detected. Real-time single particle measurements made using an aerosol time-of-flight mass spectrometer (ATOFMS) revealed the nocturnal processing of sea spray particles through the loss of particulate chloride and a simultaneous gain in particulate nitrate. Gas phase measurements are consistent with the particle phase observations: As N2O5(g) levels rose overnight, the production of ClNO2(g) coincided with the decrease in particulate chloride. These observations provide unique insight into heterogeneous reactivity from both a gas and particle phase perspective. Results from these measurements can be used to better constrain the rate of heterogeneous reactions on sea spray particles.

  12. Centroids of effective interactions from measured single-particle energies: An application

    International Nuclear Information System (INIS)

    Cole, B.J.

    1990-01-01

    Centroids of the effective nucleon-nucleon interaction for the mass region A=28--64 are extracted directly from experimental single-particle spectra, by comparing single-particle energies relative to different cores. Uncertainties in the centroids are estimated at approximately 100 keV, except in cases of exceptional fragmentation of the single-particle strength. The use of a large number of inert cores allows the dependence of the interaction on mass or model space to be investigated. The method permits accurate empirical modifications to be made to realistic interactions calculated from bare nucleon-nucleon potentials, which are known to possess defective centroids in many cases. In addition, the centroids can be used as input to the more sophisticated fitting procedures that are employed to produce matrix elements of the effective interaction

  13. A single use electrochemical sensor based on biomimetic nanoceria for the detection of wine antioxidants.

    Science.gov (United States)

    Andrei, Veronica; Sharpe, Erica; Vasilescu, Alina; Andreescu, Silvana

    2016-08-15

    We report the development and characterization of a disposable single use electrochemical sensor based on the oxidase-like activity of nanoceria particles for the detection of phenolic antioxidants. The use of nanoceria in the sensor design enables oxidation of phenolic compounds, particularly those with ortho-dihydroxybenzene functionality, to their corresponding quinones at the surface of a screen printed carbon electrode. Detection is carried out by electrochemical reduction of the resulting quinone at a low applied potential of -0.1V vs the Ag/AgCl electrode. The sensor was optimized and characterized with respect to particle loading, applied potential, response time, detection limit, linear concentration range and sensitivity. The method enabled rapid detection of common phenolic antioxidants including caffeic acid, gallic acid and quercetin in the µM concentration range, and demonstrated good functionality for the analysis of antioxidant content in several wine samples. The intrinsic oxidase-like activity of nanoceria shows promise as a robust tool for sensitive and cost effective analysis of antioxidants using electrochemical detection. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Improved identification of primary biological aerosol particles using single-particle mass spectrometry

    Directory of Open Access Journals (Sweden)

    M. A. Zawadowicz

    2017-06-01

    Full Text Available Measurements of primary biological aerosol particles (PBAP, especially at altitudes relevant to cloud formation, are scarce. Single-particle mass spectrometry (SPMS has been used to probe aerosol chemical composition from ground and aircraft for over 20 years. Here we develop a method for identifying bioaerosols (PBAP and particles containing fragments of PBAP as part of an internal mixture using SPMS. We show that identification of bioaerosol using SPMS is complicated because phosphorus-bearing mineral dust and phosphorus-rich combustion by-products such as fly ash produce mass spectra with peaks similar to those typically used as markers for bioaerosol. We have developed a methodology to differentiate and identify bioaerosol using machine learning statistical techniques applied to mass spectra of known particle types. This improved method provides far fewer false positives compared to approaches reported in the literature. The new method was then applied to two sets of ambient data collected at Storm Peak Laboratory and a forested site in Central Valley, California to show that 0.04–2 % of particles in the 200–3000 nm aerodynamic diameter range were identified as bioaerosol. In addition, 36–56 % of particles identified as biological also contained spectral features consistent with mineral dust, suggesting internal dust–biological mixtures.

  15. Study of single particle properties of nuclei in the region of the "island of inversion" by means of neutron-transfer reactions

    CERN Multimedia

    Kruecken, R; Voulot, D

    2007-01-01

    We are aiming at the investigation of single particle properties of neutron-rich nuclei in the region of the "island of inversion" where intruder states from the $\\{fp}$-shell favour deformed ground states instead of the normal spherical $\\textit{sd}$-shell states. As first experiment, we propose to study single particle states in the neutron-rich isotope $^{31}$Mg. The nucleus will be populated by a one-neutron transfer reaction with a $^{30}$Mg beam at 3 MeV/u obtained from REX-ISOLDE impinging on a CD$_{2}$ target. The $\\gamma$-rays will be detected by the MINIBALL array and the particles by a newly built set-up of segmented Si detectors with a angular coverage of nearly 4$\\pi$. Relative spectroscopic factors extracted from the cross sections will enable us to pin down the configurations of the populated states. These will be compared to recent shell model calculations involving new residual interactions. This will shed new light on the evolution of single particle structure leading to the breaking of the ...

  16. Remote detection of single emitters via optical waveguides

    Science.gov (United States)

    Then, Patrick; Razinskas, Gary; Feichtner, Thorsten; Haas, Philippe; Wild, Andreas; Bellini, Nicola; Osellame, Roberto; Cerullo, Giulio; Hecht, Bert

    2014-05-01

    The integration of lab-on-a-chip technologies with single-molecule detection techniques may enable new applications in analytical chemistry, biotechnology, and medicine. We describe a method based on the reciprocity theorem of electromagnetic theory to determine and optimize the detection efficiency of photons emitted by single quantum emitters through truncated dielectric waveguides of arbitrary shape positioned in their proximity. We demonstrate experimentally that detection of single quantum emitters via such waveguides is possible, confirming the predicted behavior of the detection efficiency. Our findings blaze the trail towards efficient lensless single-emitter detection compatible with large-scale optofluidic integration.

  17. Astrophysical dark matter: candidates from particle physics and detection possibilities

    International Nuclear Information System (INIS)

    Freese, K.

    1989-01-01

    In this talk, I will discuss the arguments that 50% to 90% of the matter in galaxies, including our own, is made of an unknown type of dark matter. I will review the reason why cosmologists believe Ω = 1 and illustrate the contrast with the limits on the amount of baryonic matter from element abundances in Big Bang Nucleosynthesis. Other arguments for nonbaryonic dark matter will also be discussed. Candidates for the dark matter from particle physics will be presented. I will focus on cold dark matter candidates known as WIMPs, weakly interacting massive (O(GeV)) particles. I will try to illustrate why these particles are interesting for astrophysics and outline ideas for cornering them. Detection possibilities for these particles include indirect detection, which takes advantage of the annihilation products of these particles in the galactic halo, the sun, or the earth. Direct detection via newly proposed cryogenic detectors must be sensitive to <∼ keV energy deposits. Annual modulation of the dark matter signal can be used as a signature for these halo particles. I hope to motivate the interest in these particles and discuss ideas for finding them

  18. Two-particle versus three-particle interactions in single ionization of helium by ion impact

    International Nuclear Information System (INIS)

    Schulz, M; Moshammer, R; Fischer, D; Ullrich, J

    2004-01-01

    We have performed kinematically complete experiments on single ionization of He by 100 MeV amu -1 C 6+ and 3.6 MeV amu -1 Au 24,53+ impact. By analysing doubly differential cross sections (DDCS) as a function of the momenta of all two-particle sub-systems we studied the importance of two-particle interactions. Furthermore, presenting the squared momenta of all three collision fragments simultaneously in a Dalitz plot, we evaluated the role of three-particle interactions. Finally, both for the DDCS and the Dalitz plots the corresponding correlation function was analysed. While the absolute cross sections confirm that ionization predominantly leads to a momentum exchange between the electron and the recoil-ion, the correlation function reveals strong correlations between the particles of any two-particle sub-system. Three-particle correlations, which are not accounted for by perturbative calculations, are quite significant as well, at least for certain kinematic conditions

  19. Localization and force analysis at the single virus particle level using atomic force microscopy

    International Nuclear Information System (INIS)

    Liu, Chih-Hao; Horng, Jim-Tong; Chang, Jeng-Shian; Hsieh, Chung-Fan; Tseng, You-Chen; Lin, Shiming

    2012-01-01

    Highlights: ► Localization of single virus particle. ► Force measurements. ► Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  20. The associated particle method explosives detection technology

    International Nuclear Information System (INIS)

    An Li; Chen Yuan; Guo Haiping; Zheng Pu; Wang Xinhua; He Tie; Mu Yunfeng; Yang Xiaofei; Zhu Chuanxin

    2009-01-01

    This article introduces the basic principle of associated alpha particles technique for explosives' inspection and the measurement system. The characteristic prompt gamma-rays come from water, graphite, liquid nitrogen, ammonium nitrate, melamine and simulated samples induced by D-T neutron from generator were gained by single alpha particles detector and gamma-ray detector. The complex gamma-ray spectra were deconvolved. The element ratio between the experiment and chemics molecular formula is agreement in 10%. (authors)

  1. Single particle behaviour in circulating fluidized bed combustors

    DEFF Research Database (Denmark)

    Erik Weinell, Claus

    1994-01-01

    An investigation of single particle behaviour in a circulating fluidized bed combustor is described, relating to sulphur capture reactions by limestone under alternate oxidizing and reducing conditions present in a circulating fluidized bed combustor, and to the devolatilization and burn out...

  2. A deep convolutional neural network approach to single-particle recognition in cryo-electron microscopy.

    Science.gov (United States)

    Zhu, Yanan; Ouyang, Qi; Mao, Youdong

    2017-07-21

    Single-particle cryo-electron microscopy (cryo-EM) has become a mainstream tool for the structural determination of biological macromolecular complexes. However, high-resolution cryo-EM reconstruction often requires hundreds of thousands of single-particle images. Particle extraction from experimental micrographs thus can be laborious and presents a major practical bottleneck in cryo-EM structural determination. Existing computational methods for particle picking often use low-resolution templates for particle matching, making them susceptible to reference-dependent bias. It is critical to develop a highly efficient template-free method for the automatic recognition of particle images from cryo-EM micrographs. We developed a deep learning-based algorithmic framework, DeepEM, for single-particle recognition from noisy cryo-EM micrographs, enabling automated particle picking, selection and verification in an integrated fashion. The kernel of DeepEM is built upon a convolutional neural network (CNN) composed of eight layers, which can be recursively trained to be highly "knowledgeable". Our approach exhibits an improved performance and accuracy when tested on the standard KLH dataset. Application of DeepEM to several challenging experimental cryo-EM datasets demonstrated its ability to avoid the selection of un-wanted particles and non-particles even when true particles contain fewer features. The DeepEM methodology, derived from a deep CNN, allows automated particle extraction from raw cryo-EM micrographs in the absence of a template. It demonstrates an improved performance, objectivity and accuracy. Application of this novel method is expected to free the labor involved in single-particle verification, significantly improving the efficiency of cryo-EM data processing.

  3. Projection operator treatment of single particle resonances

    International Nuclear Information System (INIS)

    Lev, A.; Beres, W.P.

    1976-01-01

    A projection operator method is used to obtain the energy and width of a single particle resonance. The resonance energy is found without scanning. An example of the first g/sub 9/2/ neutron resonance in 40 Ca is given and compared with the traditional phase shift method. The results of both approaches are quite similar. 4 figures

  4. Visualization of Content Release from Cell Surface-Attached Single HIV-1 Particles Carrying an Extra-Viral Fluorescent pH-Sensor.

    Science.gov (United States)

    Sood, Chetan; Marin, Mariana; Mason, Caleb S; Melikyan, Gregory B

    2016-01-01

    HIV-1 fusion leading to productive entry has long been thought to occur at the plasma membrane. However, our previous single virus imaging data imply that, after Env engagement of CD4 and coreceptors at the cell surface, the virus enters into and fuses with intracellular compartments. We were unable to reliably detect viral fusion at the plasma membrane. Here, we implement a novel virus labeling strategy that biases towards detection of virus fusion that occurs in a pH-neutral environment-at the plasma membrane or, possibly, in early pH-neutral vesicles. Virus particles are co-labeled with an intra-viral content marker, which is released upon fusion, and an extra-viral pH sensor consisting of ecliptic pHluorin fused to the transmembrane domain of ICAM-1. This sensor fully quenches upon virus trafficking to a mildly acidic compartment, thus precluding subsequent detection of viral content release. As an interesting secondary observation, the incorporation of the pH-sensor revealed that HIV-1 particles occasionally shuttle between neutral and acidic compartments in target cells expressing CD4, suggesting a small fraction of viral particles is recycled to the plasma membrane and re-internalized. By imaging viruses bound to living cells, we found that HIV-1 content release in neutral-pH environment was a rare event (~0.4% particles). Surprisingly, viral content release was not significantly reduced by fusion inhibitors, implying that content release was due to spontaneous formation of viral membrane defects occurring at the cell surface. We did not measure a significant occurrence of HIV-1 fusion at neutral pH above this defect-mediated background loss of content, suggesting that the pH sensor may destabilize the membrane of the HIV-1 pseudovirus and, thus, preclude reliable detection of single virus fusion events at neutral pH.

  5. Visualization of Content Release from Cell Surface-Attached Single HIV-1 Particles Carrying an Extra-Viral Fluorescent pH-Sensor.

    Directory of Open Access Journals (Sweden)

    Chetan Sood

    Full Text Available HIV-1 fusion leading to productive entry has long been thought to occur at the plasma membrane. However, our previous single virus imaging data imply that, after Env engagement of CD4 and coreceptors at the cell surface, the virus enters into and fuses with intracellular compartments. We were unable to reliably detect viral fusion at the plasma membrane. Here, we implement a novel virus labeling strategy that biases towards detection of virus fusion that occurs in a pH-neutral environment-at the plasma membrane or, possibly, in early pH-neutral vesicles. Virus particles are co-labeled with an intra-viral content marker, which is released upon fusion, and an extra-viral pH sensor consisting of ecliptic pHluorin fused to the transmembrane domain of ICAM-1. This sensor fully quenches upon virus trafficking to a mildly acidic compartment, thus precluding subsequent detection of viral content release. As an interesting secondary observation, the incorporation of the pH-sensor revealed that HIV-1 particles occasionally shuttle between neutral and acidic compartments in target cells expressing CD4, suggesting a small fraction of viral particles is recycled to the plasma membrane and re-internalized. By imaging viruses bound to living cells, we found that HIV-1 content release in neutral-pH environment was a rare event (~0.4% particles. Surprisingly, viral content release was not significantly reduced by fusion inhibitors, implying that content release was due to spontaneous formation of viral membrane defects occurring at the cell surface. We did not measure a significant occurrence of HIV-1 fusion at neutral pH above this defect-mediated background loss of content, suggesting that the pH sensor may destabilize the membrane of the HIV-1 pseudovirus and, thus, preclude reliable detection of single virus fusion events at neutral pH.

  6. Determination of particle-release conditions in microfiltration: A simple single-particle model tested on a model membrane

    NARCIS (Netherlands)

    Kuiper, S.; van Rijn, C.J.M.; Nijdam, W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2000-01-01

    A simple single-particle model was developed for cross-flow microfiltration with microsieves. The model describes the cross-flow conditions required to release a trapped spherical particle from a circular pore. All equations are derived in a fully analytical way without any fitting parameters. For

  7. Localization and force analysis at the single virus particle level using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chih-Hao [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Horng, Jim-Tong [Department of Biochemistry, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan (China); Chang, Jeng-Shian [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Hsieh, Chung-Fan [Graduate Institute of Biomedical Sciences, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China); Tseng, You-Chen [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Lin, Shiming, E-mail: til@ntu.edu.tw [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Optoelectronic Biomedicine, College of Medicine, Nation Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan (China)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Localization of single virus particle. Black-Right-Pointing-Pointer Force measurements. Black-Right-Pointing-Pointer Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  8. Raman mapping of mannitol/lysozyme particles produced via spray drying and single droplet drying.

    Science.gov (United States)

    Pajander, Jari Pekka; Matero, Sanni; Sloth, Jakob; Wan, Feng; Rantanen, Jukka; Yang, Mingshi

    2015-06-01

    This study aimed to investigate the effect of a model protein on the solid state of a commonly used bulk agent in spray-dried formulations. A series of lysozyme/mannitol formulations were spray-dried using a lab-scale spray dryer. Further, the surface temperature of drying droplet/particles was monitored using the DRYING KINETICS ANALYZER™ (DKA) with controllable drying conditions mimicking the spray-drying process to estimate the drying kinetics of the lysozyme/mannitol formulations. The mannitol polymorphism and the spatial distribution of lysozyme in the particles were examined using X-ray powder diffractometry (XRPD) and Raman microscopy. Partial Least Squares Discriminant Analysis was used for analyzing the Raman microscopy data. XRPD results indicated that a mixture of β-mannitol and α-mannitol was produced in the spray-drying process which was supported by the Raman analysis, whereas Raman analysis indicated that a mixture of α-mannitol and δ-mannitol was detected in the single particles from DKA. In addition Raman mapping indicated that the presence of lysozyme seemed to favor the appearance of α-mannitol in the particles from DKA evidenced by close proximity of lysozyme and mannitol in the particles. It suggested that the presence of lysozyme tend to induce metastable solid state forms upon the drying process.

  9. Quantitative single-particle digital autoradiography with α-particle emitters for targeted radionuclide therapy using the iQID camera.

    Science.gov (United States)

    Miller, Brian W; Frost, Sofia H L; Frayo, Shani L; Kenoyer, Aimee L; Santos, Erlinda; Jones, Jon C; Green, Damian J; Hamlin, Donald K; Wilbur, D Scott; Fisher, Darrell R; Orozco, Johnnie J; Press, Oliver W; Pagel, John M; Sandmaier, Brenda M

    2015-07-01

    Alpha-emitting radionuclides exhibit a potential advantage for cancer treatments because they release large amounts of ionizing energy over a few cell diameters (50-80 μm), causing localized, irreparable double-strand DNA breaks that lead to cell death. Radioimmunotherapy (RIT) approaches using monoclonal antibodies labeled with α emitters may thus inactivate targeted cells with minimal radiation damage to surrounding tissues. Tools are needed to visualize and quantify the radioactivity distribution and absorbed doses to targeted and nontargeted cells for accurate dosimetry of all treatment regimens utilizing α particles, including RIT and others (e.g., Ra-223), especially for organs and tumors with heterogeneous radionuclide distributions. The aim of this study was to evaluate and characterize a novel single-particle digital autoradiography imager, the ionizing-radiation quantum imaging detector (iQID) camera, for use in α-RIT experiments. The iQID camera is a scintillator-based radiation detection system that images and identifies charged-particle and gamma-ray/x-ray emissions spatially and temporally on an event-by-event basis. It employs CCD-CMOS cameras and high-performance computing hardware for real-time imaging and activity quantification of tissue sections, approaching cellular resolutions. In this work, the authors evaluated its characteristics for α-particle imaging, including measurements of intrinsic detector spatial resolutions and background count rates at various detector configurations and quantification of activity distributions. The technique was assessed for quantitative imaging of astatine-211 ((211)At) activity distributions in cryosections of murine and canine tissue samples. The highest spatial resolution was measured at ∼20 μm full width at half maximum and the α-particle background was measured at a rate as low as (2.6 ± 0.5) × 10(-4) cpm/cm(2) (40 mm diameter detector area). Simultaneous imaging of multiple tissue sections was

  10. Collective and single-particle states at high excitation energy

    International Nuclear Information System (INIS)

    Van den Berg, A.M.; Van der Molen, H.K.T.; Harakeh, M.N.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Ihara, F.; Inomata, T.

    2000-01-01

    Complete text of publication follows. Damping of high-lying single-particle states was investigated by the study of proton decay from high-lying states in 91 Nb, populated by the 90 Zr(α,t) reaction with E α = 180 MeV. In addition to decay to the ground state of 90 Zr, semi-direct decay was observed to the low-lying (2 + and 3 - ) phonon states, confirming the conclusion from other experiments that these phonon states play an important role in the damping process of the single-particle states. Furthermore, the population and decay of Isobaric Analogue States of 91 Zr, which are located at an excitation energy of about 10 - 12 MeV in 91 Nb, has been studied in the same reaction. (author)

  11. Virus Particle Detection by Convolutional Neural Network in Transmission Electron Microscopy Images.

    Science.gov (United States)

    Ito, Eisuke; Sato, Takaaki; Sano, Daisuke; Utagawa, Etsuko; Kato, Tsuyoshi

    2018-06-01

    A new computational method for the detection of virus particles in transmission electron microscopy (TEM) images is presented. Our approach is to use a convolutional neural network that transforms a TEM image to a probabilistic map that indicates where virus particles exist in the image. Our proposed approach automatically and simultaneously learns both discriminative features and classifier for virus particle detection by machine learning, in contrast to existing methods that are based on handcrafted features that yield many false positives and require several postprocessing steps. The detection performance of the proposed method was assessed against a dataset of TEM images containing feline calicivirus particles and compared with several existing detection methods, and the state-of-the-art performance of the developed method for detecting virus was demonstrated. Since our method is based on supervised learning that requires both the input images and their corresponding annotations, it is basically used for detection of already-known viruses. However, the method is highly flexible, and the convolutional networks can adapt themselves to any virus particles by learning automatically from an annotated dataset.

  12. Massively parallel unsupervised single-particle cryo-EM data clustering via statistical manifold learning.

    Directory of Open Access Journals (Sweden)

    Jiayi Wu

    Full Text Available Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM. We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.

  13. Massively parallel unsupervised single-particle cryo-EM data clustering via statistical manifold learning.

    Science.gov (United States)

    Wu, Jiayi; Ma, Yong-Bei; Congdon, Charles; Brett, Bevin; Chen, Shuobing; Xu, Yaofang; Ouyang, Qi; Mao, Youdong

    2017-01-01

    Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM) data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR) in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM). We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC) environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.

  14. Fractal and Morphological Characteristics of Single Marble Particle Crushing in Uniaxial Compression Tests

    Directory of Open Access Journals (Sweden)

    Yidong Wang

    2015-01-01

    Full Text Available Crushing of rock particles is a phenomenon commonly encountered in geotechnical engineering practice. It is however difficult to study the crushing of rock particles using classical theory because the physical structure of the particles is complex and irregular. This paper aims at evaluating fractal and morphological characteristics of single rock particle. A large number of particle crushing tests are conducted on single rock particle. The force-displacement curves and the particle size distributions (PSD of crushed particles are analysed based on particle crushing tests. Particle shape plays an important role in both the micro- and macroscale responses of a granular assembly. The PSD of an assortment of rocks are analysed by fractal methods, and the fractal dimension is obtained. A theoretical formula for particle crushing strength is derived, utilising the fractal model, and a simple method is proposed for predicting the probability of particle survival based on the Weibull statistics. Based on a few physical assumptions, simple equations are derived for determining particle crushing energy. The results of applying these equations are tested against the actual experimental data and prove to be very consistent. Fractal theory is therefore applicable for analysis of particle crushing.

  15. Real-time analysis of insoluble particles in glacial ice using single-particle mass spectrometry

    Science.gov (United States)

    Osman, Matthew; Zawadowicz, Maria A.; Das, Sarah B.; Cziczo, Daniel J.

    2017-11-01

    Insoluble aerosol particles trapped in glacial ice provide insight into past climates, but analysis requires information on climatically relevant particle properties, such as size, abundance, and internal mixing. We present a new analytical method using a time-of-flight single-particle mass spectrometer (SPMS) to determine the composition and size of insoluble particles in glacial ice over an aerodynamic size range of ˜ 0.2-3.0 µm diameter. Using samples from two Greenland ice cores, we developed a procedure to nebulize insoluble particles suspended in melted ice, evaporate condensed liquid from those particles, and transport them to the SPMS for analysis. We further determined size-dependent extraction and instrument transmission efficiencies to investigate the feasibility of determining particle-class-specific mass concentrations. We find SPMS can be used to provide constraints on the aerodynamic size, composition, and relative abundance of most insoluble particulate classes in ice core samples. We describe the importance of post-aqueous processing to particles, a process which occurs due to nebulization of aerosols from an aqueous suspension of originally soluble and insoluble aerosol components. This study represents an initial attempt to use SPMS as an emerging technique for the study of insoluble particulates in ice cores.

  16. Acoustic detection of melt particles

    International Nuclear Information System (INIS)

    Costley, R.D. Jr.

    1988-01-01

    The Reactor Safety Research Department at Sandia National Laboratories is investigating a type of Loss of Coolant Accident (LOCA). In this particular type of accident, core meltdown occurs while the pressure within the reactor pressure vessel (RPV) is high. If one of the instrument tube penetrations in the lower head fails, melt particles stream through the cavity and into the containment vessel. This experiment, which simulates this type accident, was performed in the Surtsev Direct Heating Test Facility which is approximately a 1:10 linear scaling of a large dry containment volume. A 1:10 linear scale model of the reactor cavity was placed near the bottom of the Surtsey vessel so that the exit of the cavity was at the vertical centerline of the vessel. A pressure vessel used to create the simulated molten core debris was located at the scaled height of the RPV. In order to better understand how the melt leaves the cavity and streams into the containment an array of five acoustic sensors was placed directly in the path of the melt particles about 30 feet from the exit of the sealed cavity. Highly damped, broadband sensors were chosen to minimize ringing so that individual particle hits could be detected. The goal was to count the signals produced by the individual particle hits to get some idea of how the melt particles left the cavity. This document presents some of the results of the experiment. 9 figs

  17. Single-particle spectral density of the Hubbard model

    NARCIS (Netherlands)

    Mehlig, B.; Eskes, H.; Hayn, R.; Meinders, M.B.J.

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  18. SINGLE-PARTICLE SPECTRAL DENSITY OF THE HUBBARD-MODEL

    NARCIS (Netherlands)

    MEHLIG, B; ESKES, H; HAYN, R; MEINDERS, MBJ

    1995-01-01

    We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,

  19. Use of the diamond to the detection of particles

    International Nuclear Information System (INIS)

    Mer, C.; Tromson, D.; Brambilla, A.; Foulon, F.; Guizard, B.; Bergonzo

    2001-01-01

    Diamond synthesized by chemical vapor deposition (CVD) is a valuable material for the detection of particles: broad forbidden energy band, high mobility of electron-hole pairs, and a short life-time of charge carriers. Diamond layers have been used in alpha detectors or gamma dose ratemeters designed to be used in hostile environment. Diamond presents a high resistance to radiation and corrosion. The properties of diamond concerning the detection of particles are spoilt by the existence of crystal defects even in high quality natural or synthesized diamond. This article presents recent works that have been performed in CEA laboratories in order to optimize the use of CVD diamond in particle detectors. (A.C.)

  20. Single particle dynamics of many-body systems described by Vlasov-Fokker-Planck equations

    International Nuclear Information System (INIS)

    Frank, T.D.

    2003-01-01

    Using Langevin equations we describe the random walk of single particles that belong to particle systems satisfying Vlasov-Fokker-Planck equations. In doing so, we show that Haissinski distributions of bunched particles in electron storage rings can be derived from a particle dynamics model

  1. SQUID sensor application for small metallic particle detection

    International Nuclear Information System (INIS)

    Tanaka, Saburo; Hatsukade, Yoshimi; Ohtani, Takeyoshi; Suzuki, Shuichi

    2009-01-01

    High-Tc superconducting quantum interference device (SQUID) is an ultra-sensitive magnetic sensor. Since the performance of the SQUID is improved and stabilized, now it is ready for application. One strong candidate for application is a detection system of magnetic foreign matters in industrial products or beverages. There is a possibility that ultra-small metallic foreign matter has been accidentally mixed with industrial products such as lithium ion batteries. If this happens, the manufacturer of the product suffers a great loss recalling products. The outer dimension of metallic particles less than 100 μm cannot be detected by an X-ray imaging, which is commonly used for the inspection. Ionization of the material is also a big issue for beverages in the case of the X-ray imaging. Therefore a highly sensitive and safety detection system for small foreign matters is required. We developed detection systems based on high-Tc SQUID with a high-performance magnetic shield. We could successfully measure small iron particles of 100 μm on a belt conveyer and stainless steel balls of 300 μm in water. These detection levels were hard to be achieved by a conventional X-ray detection or other methods

  2. Development of a high throughput single-particle screening for inorganic semiconductor nanorods as neural voltage sensor

    Science.gov (United States)

    Kuo, Yung; Park, Kyoungwon; Li, Jack; Ingargiola, Antonino; Park, Joonhyuck; Shvadchak, Volodymyr; Weiss, Shimon

    2017-08-01

    Monitoring membrane potential in neurons requires sensors with minimal invasiveness, high spatial and temporal (sub-ms) resolution, and large sensitivity for enabling detection of sub-threshold activities. While organic dyes and fluorescent proteins have been developed to possess voltage-sensing properties, photobleaching, cytotoxicity, low sensitivity, and low spatial resolution have obstructed further studies. Semiconductor nanoparticles (NPs), as prospective voltage sensors, have shown excellent sensitivity based on Quantum confined Stark effect (QCSE) at room temperature and at single particle level. Both theory and experiment have shown their voltage sensitivity can be increased significantly via material, bandgap, and structural engineering. Based on theoretical calculations, we synthesized one of the optimal candidates for voltage sensors: 12 nm type-II ZnSe/CdS nanorods (NRs), with an asymmetrically located seed. The voltage sensitivity and spectral shift were characterized in vitro using spectrally-resolved microscopy using electrodes grown by thin film deposition, which "sandwich" the NRs. We characterized multiple batches of such NRs and iteratively modified the synthesis to achieve higher voltage sensitivity (ΔF/F> 10%), larger spectral shift (>5 nm), better homogeneity, and better colloidal stability. Using a high throughput screening method, we were able to compare the voltage sensitivity of our NRs with commercial spherical quantum dots (QDs) with single particle statistics. Our method of high throughput screening with spectrally-resolved microscope also provides a versatile tool for studying single particles spectroscopy under field modulation.

  3. Reconstructing an icosahedral virus from single-particle diffraction experiments

    Science.gov (United States)

    Saldin, D. K.; Poon, H.-C.; Schwander, P.; Uddin, M.; Schmidt, M.

    2011-08-01

    The first experimental data from single-particle scattering experiments from free electron lasers (FELs) are now becoming available. The first such experiments are being performed on relatively large objects such as viruses, which produce relatively low-resolution, low-noise diffraction patterns in so-called ``diffract-and-destroy'' experiments. We describe a very simple test on the angular correlations of measured diffraction data to determine if the scattering is from an icosahedral particle. If this is confirmed, the efficient algorithm proposed can then combine diffraction data from multiple shots of particles in random unknown orientations to generate a full 3D image of the icosahedral particle. We demonstrate this with a simulation for the satellite tobacco necrosis virus (STNV), the atomic coordinates of whose asymmetric unit is given in Protein Data Bank entry 2BUK.

  4. Non-identical particle femtoscopy in models with single freeze-out

    International Nuclear Information System (INIS)

    Kisiel, Adam

    2007-01-01

    We present femtoscopic results from hydrodynamics-inspired thermal models with single freeze-out. Non-identical particle femtoscopy is studied and compared to results of identical particle correlations. Special emphasis is put on shifts between average space-time emission points of non-identical particles of different masses. They are found to be sensitive to both the spatial shift coming from radial flow, as well as average emission time difference coming from the resonance decays. The Terminator Monte-Carlo program was chosen for this study because it realistically models both of these effects. In order to analyze the results we present and test the methodology of non-identical particle correlations. (author)

  5. Single-particle stochastic heat engine

    Science.gov (United States)

    Rana, Shubhashis; Pal, P. S.; Saha, Arnab; Jayannavar, A. M.

    2014-10-01

    We have performed an extensive analysis of a single-particle stochastic heat engine constructed by manipulating a Brownian particle in a time-dependent harmonic potential. The cycle consists of two isothermal steps at different temperatures and two adiabatic steps similar to that of a Carnot engine. The engine shows qualitative differences in inertial and overdamped regimes. All the thermodynamic quantities, including efficiency, exhibit strong fluctuations in a time periodic steady state. The fluctuations of stochastic efficiency dominate over the mean values even in the quasistatic regime. Interestingly, our system acts as an engine provided the temperature difference between the two reservoirs is greater than a finite critical value which in turn depends on the cycle time and other system parameters. This is supported by our analytical results carried out in the quasistatic regime. Our system works more reliably as an engine for large cycle times. By studying various model systems, we observe that the operational characteristics are model dependent. Our results clearly rule out any universal relation between efficiency at maximum power and temperature of the baths. We have also verified fluctuation relations for heat engines in time periodic steady state.

  6. Temperature dependence of single-particle properties in nuclear matter

    International Nuclear Information System (INIS)

    Zuo, W.; Lu, G.C.; Li, Z.H.; Lombardo, U.; Schulze, H.-J.

    2006-01-01

    The single-nucleon potential in hot nuclear matter is investigated in the framework of the Brueckner theory by adopting the realistic Argonne V 18 or Nijmegen 93 two-body nucleon-nucleon interaction supplemented by a microscopic three-body force. The rearrangement contribution to the single-particle potential induced by the ground state correlations is calculated in terms of the hole-line expansion of the mass operator and provides a significant repulsive contribution in the low-momentum region around and below the Fermi surface. Increasing temperature leads to a reduction of the effect, while increasing density makes it become stronger. The three-body force suppresses somewhat the ground state correlations due to its strong short-range repulsion, increasing with density. Inclusion of the three-body force contribution results in a quite different temperature dependence of the single-particle potential at high enough densities as compared to that adopting the pure two-body force. The effects of three-body force and ground state correlations on the nucleon effective mass are also discussed

  7. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.

    Science.gov (United States)

    Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas

    2015-07-01

    In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

  8. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics

    Science.gov (United States)

    Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T.; Bohr, Tomas

    2015-07-01

    In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006), 10.1103/PhysRevLett.97.154101] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

  9. Chemical compositions of subway particles in Seoul, Korea determined by a quantitative single particle analysis.

    Science.gov (United States)

    Kang, Sunni; Hwang, HeeJin; Park, YooMyung; Kim, HyeKyoung; Ro, Chul-Un

    2008-12-15

    A novel single particle analytical technique, low-Z particle electron probe X-ray microanalysis, was applied to characterize seasonal subway samples collected at a subway station in Seoul, Korea. For all 8 samples collected twice in each season, 4 major types of subway particles, based on their chemical compositions, are significantly encountered: Fe-containing; soil-derived; carbonaceous; and secondary nitrate and/or sulfate particles. Fe-containing particles are generated indoors from wear processes at rail-wheel-brake interfaces while the others may be introduced mostly from the outdoor urban atmosphere. Fe-containing particles are the most frequently encountered with relative abundances in the range of 61-79%. In this study, it is shown that Fe-containing subway particles almost always exist either as partially or fully oxidized forms in underground subway microenvironments. Their relative abundances of Fe-containing particles increase as particle sizes decrease. Relative abundances of Fe-containing particles are higher in morning samples than in afternoon samples because of heavier train traffic in the morning. In the summertime samples, Fe-containing particles are the most abundantly encountered, whereas soil-derived and nitrate/sulfate particles are the least encountered, indicating the air-exchange between indoor and outdoor environments is limited in the summer, owing to the air-conditioning in the subway system. In our work, it was observed that the relative abundances of the particles of outdoor origin vary somewhat among seasonal samples to a lesser degree, reflecting that indoor emission sources predominate.

  10. Surface crack detection by magnetic particle inspection

    International Nuclear Information System (INIS)

    Goebbels, K.

    1988-01-01

    For ferromagnetic materials magnetic particle inspection is without doubt the most sensitive method to detect surface cracks and the least sensitive method referring to disturbing boundary conditions. Up to now the technique is based on experiments, experience, on empirical facts and on a subjective evaluation. This contribution for the first time presents a concept which allows the objective, reproducible as well as reliable magnetic particle inspection: Modelling of testing based on Maxwell's equations by finite element calculation; objective setting of test-parameters and their surveillance, handling systems, illumination and sensors, image processing and fully automated evaluation. Economy and safety of magnetic particle inspection are strongly improved by this procedure. (orig./HP) [de

  11. Acoustic Detection Of Loose Particles In Pressure Sensors

    Science.gov (United States)

    Kwok, Lloyd C.

    1995-01-01

    Particle-impact-noise-detector (PIND) apparatus used in conjunction with computer program analyzing output of apparatus to detect extraneous particles trapped in pressure sensors. PIND tester essentially shaker equipped with microphone measuring noise in pressure sensor or other object being shaken. Shaker applies controlled vibration. Output of microphone recorded and expressed in terms of voltage, yielding history of noise subsequently processed by computer program. Data taken at sampling rate sufficiently high to enable identification of all impacts of particles on sensor diaphragm and on inner surfaces of sensor cavities.

  12. MAPPIX: A software package for off-line micro-pixe single particle aerosol analysis

    International Nuclear Information System (INIS)

    Ceccato, D.

    2009-01-01

    In the framework of a multiannual experiment performed at Baia Terra Nova, Antarctica, size-segregated aerosol samples were collected by using a 12-stage SDI impactor (Hillamo design). Approximately 2800 particles, belonging to the first four supermicrometric SDI stages - 8.39, 4.08, 2.68, 1.66 μm dynamic aerosol diameter cuts - were analyzed at the INFN-LNL micro-PIXE facility, a three lens Oxford Microprobe (OM) product, installed in the early nineties. Four regions on each of the 12 sub-samples were measured; 60 aerosol particles were detected on average in each of the analyzed regions. The off-line single aerosol particle (SAP) analysis of such big amount of data required software that is able to rapidly handle the acquired data, with a simple and fast area selection procedure; the subsequent automated PIXE spectra analysis with a specialized code was also needed. The MAPPIX 2.0 software was designed to make easier and faster the user jobs during the SAP analysis. The package is composed of two separate routines: the first one is devoted to data format conversion (OM-LMF file format to MAPPIX format), while the second one is devoted to micro-PIXE maps graphical presentation and aerosol particle selection procedure. The MAPPIX data format and software features will be discussed; a short report of the speed performances will be presented.

  13. Decay properties of high-lying single-particles modes

    NARCIS (Netherlands)

    Beaumel, D; Fortier, S; Gales, S; Guillot, J; LangevinJoliot, H; Laurent, H; Maison, JM; Vernotte, J; Bordewijck, J; Brandenburg, S; Krasznahorkay, A; Crawley, GM; Massolo, CP; Renteria, M; Khendriche, A

    1996-01-01

    The neutron decay of high-lying single-particle states in Ni-64, Zr-90, Sn-120 and (208)pb excited by means of the (alpha,He-3) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular

  14. Determining Complex Structures using Docking Method with Single Particle Scattering Data

    Directory of Open Access Journals (Sweden)

    Haiguang Liu

    2017-04-01

    Full Text Available Protein complexes are critical for many molecular functions. Due to intrinsic flexibility and dynamics of complexes, their structures are more difficult to determine using conventional experimental methods, in contrast to individual subunits. One of the major challenges is the crystallization of protein complexes. Using X-ray free electron lasers (XFELs, it is possible to collect scattering signals from non-crystalline protein complexes, but data interpretation is more difficult because of unknown orientations. Here, we propose a hybrid approach to determine protein complex structures by combining XFEL single particle scattering data with computational docking methods. Using simulations data, we demonstrate that a small set of single particle scattering data collected at random orientations can be used to distinguish the native complex structure from the decoys generated using docking algorithms. The results also indicate that a small set of single particle scattering data is superior to spherically averaged intensity profile in distinguishing complex structures. Given the fact that XFEL experimental data are difficult to acquire and at low abundance, this hybrid approach should find wide applications in data interpretations.

  15. Single particle and molecular assembly analysis of polyribosomes by single- and double-tilt cryo electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Myasnikov, Alexander G. [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Department of Integrative Structural Biology, Centre National de la Recherche Scientifique (CNRS) UMR 7104/ Institut National de la Santé de la Recherche Médicale INSERM U964/ Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch (France); Afonina, Zhanna A. [Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region (Russian Federation); Klaholz, Bruno P., E-mail: klaholz@igbmc.fr [IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Department of Integrative Structural Biology, Centre National de la Recherche Scientifique (CNRS) UMR 7104/ Institut National de la Santé de la Recherche Médicale INSERM U964/ Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch (France)

    2013-03-15

    Cryo electron tomography (cryo-ET) can provide cellular and molecular structural information on various biological samples. However, the detailed interpretation of tomograms reconstructed from single-tilt data tends to suffer from low signal-to-noise ratio and artefacts caused by some systematically missing angular views. While these can be overcome by sub-tomogram averaging, they remain limiting for the analysis of unique structures. Double-tilt ET can improve the tomogram quality by acquiring a second tilt series after an in-plane rotation, but its usage is not widespread yet because it is considered technically demanding and it is rarely used under cryo conditions. Here we show that double-tilt cryo-ET improves the quality of 3D reconstructions so significantly that even single particle analysis can be envisaged despite of the intrinsically low image contrast obtained from frozen-hydrated specimens. This is illustrated by the analysis of eukaryotic polyribosomes in which individual ribosomes were reconstructed using single-tilt, partial and full double-tilt geometries. The improved tomograms favour the faster convergence of iterative sub-tomogram averaging and allow a better 3D classification using multivariate statistical analysis. Our study of single particles and molecular assemblies within polysomes illustrates that the dual-axis approach is particularly useful for cryo applications of ET, both for unique objects and for structures that can be classified and averaged. - Highlights: ► Double-tilt cryo-ET improves 3D reconstructions thus making single particle analysis possible. ► Dual-axis cryo-ET data favour a faster convergence of iterative sub-tomogram averaging. ► Individual ribosomes were reconstructed from single-tilt, partial/ full double-tilt geometries. ► Double-tilt cryo-ET facilitates analysis of larger molecular assemblies such as in cell sections. ► Dual-axis cryo-ET is applicable to unique objects and to structures that can be

  16. A new seniority scheme for non-degenerate single particle orbits

    International Nuclear Information System (INIS)

    Otsuka, T.; Arima, A.

    1978-01-01

    A new method is proposed in the treatment of the seniority scheme. The method enables one to evaluate analytically the contribution from J = 0 Cooper pairs in non-degenerate single-particle orbits to many-body matrix elements. It includes the SU(2) quasi-spin and the BCS approximation as two extreme limits. The effect of particle number conservation is properly taken into account. (Auth.)

  17. Single molecule detection, thermal fluctuation and life

    Science.gov (United States)

    YANAGIDA, Toshio; ISHII, Yoshiharu

    2017-01-01

    Single molecule detection has contributed to our understanding of the unique mechanisms of life. Unlike artificial man-made machines, biological molecular machines integrate thermal noises rather than avoid them. For example, single molecule detection has demonstrated that myosin motors undergo biased Brownian motion for stepwise movement and that single protein molecules spontaneously change their conformation, for switching to interactions with other proteins, in response to thermal fluctuation. Thus, molecular machines have flexibility and efficiency not seen in artificial machines. PMID:28190869

  18. Single particle ICP-MS combined with a data evaluastion tool as a routine techique for the analysis of nanoparticles in complex matrices

    NARCIS (Netherlands)

    Peters, R.J.B.; Herrera-Rivera, Z.; Undas, A.K.; Lee, van der M.K.; Marvin, H.J.P.; Bouwmeester, H.; Weigel, S.

    2015-01-01

    Detection and characterization of nanoparticles (NPs) in complex media as consumer products, food and toxicological test media is an essential part of understanding the potential benefits and risks of the application of nanoparticles. Single particle ICP-MS (spICP-MS) was studied as a screening tool

  19. Single-particle characterization of urban aerosol particles collected in three Korean cites using low-Z electron probe X-ray microanalysis.

    Science.gov (United States)

    Ro, Chul-Un; Kim, HyeKyeong; Oh, Keun-Young; Yea, Sun Kyung; Lee, Chong Bum; Jang, Meongdo; Van Grieken, René

    2002-11-15

    A recently developed single-particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA), was applied to characterize urban aerosol particles collected in three cities of Korea (Seoul, CheongJu, and ChunCheon) on single days in the winter of 1999. In this study, it is clearly demonstrated that the low-Z EPMA technique can provide detailed and quantitative information on the chemical composition of particles in the urban atmosphere. The collected aerosol particles were analyzed and classified on the basis of their chemical species. Various types of particles were identified, such as soil-derived, carbonaceous, marine-originated, and anthropogenic particles. In the sample collected in Seoul, carbonaceous, aluminosilicates, silicon dioxide, and calcium carbonate aerosol particles were abundantly encountered. In the CheongJu and ChunCheon samples, carbonaceous, aluminosilicates, reacted sea salts, and ammonium sulfate aerosol particles were often seen. However, in the CheongJu sample, ammonium sulfate particles were the most abundant in the fine fraction. Also, calcium sulfate and nitrate particles were significantly observed. In the ChunCheon sample, organic particles were the most abundant in the fine fraction. Also, sodium nitrate particles were seen at high levels. The ChunCheon sample seemed to be strongly influenced by sea-salt aerosols originating from the Yellow Sea, which is located about 115 km away from the city.

  20. Experimental Study on Effects of Particle Shape and Operating Conditions on Combustion Characteristics of Single Biomass Particles

    DEFF Research Database (Denmark)

    Momeni, M.; Yin, Chungen; Kær, Søren Knudsen

    2013-01-01

    An experimental study is performed to investigate the ignition, devolatilization, and burnout of single biomass particles of various shapes and sizes under process conditions that are similar to those in an industrial combustor. A chargecoupled device (CCD) camera is used to record the whole...... combustion process. For the particles with similar volume (mass), cylindrical particles are found to lose mass faster than spherical particles and the burnout time is shortened by increasing the particle aspect ratio (surface area). The conversion times of cylindrical particles with almost the same surface...... area/volume ratio are very close to each other. The ignition, devolatilization, and burnout times of cylindrical particles are also affected by the oxidizer temperature and oxygen concentration, in which the oxygen concentration is found to have a more pronounced effect on the conversion times at lower...

  1. Quantitative single-particle digital autoradiography with α-particle emitters for targeted radionuclide therapy using the iQID camera

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Brian W., E-mail: brian.miller@pnnl.gov [Pacific Northwest National Laboratory, Richland, Washington 99354 and College of Optical Sciences, The University of Arizona, Tucson, Arizona 85719 (United States); Frost, Sofia H. L.; Frayo, Shani L.; Kenoyer, Aimee L.; Santos, Erlinda; Jones, Jon C.; Orozco, Johnnie J. [Fred Hutchinson Cancer Research Center, Seattle, Washington 98109 (United States); Green, Damian J.; Press, Oliver W.; Pagel, John M.; Sandmaier, Brenda M. [Fred Hutchinson Cancer Research Center, Seattle, Washington 98109 and Department of Medicine, University of Washington, Seattle, Washington 98195 (United States); Hamlin, Donald K.; Wilbur, D. Scott [Department of Radiation Oncology, University of Washington, Seattle, Washington 98195 (United States); Fisher, Darrell R. [Dade Moeller Health Group, Richland, Washington 99354 (United States)

    2015-07-15

    Purpose: Alpha-emitting radionuclides exhibit a potential advantage for cancer treatments because they release large amounts of ionizing energy over a few cell diameters (50–80 μm), causing localized, irreparable double-strand DNA breaks that lead to cell death. Radioimmunotherapy (RIT) approaches using monoclonal antibodies labeled with α emitters may thus inactivate targeted cells with minimal radiation damage to surrounding tissues. Tools are needed to visualize and quantify the radioactivity distribution and absorbed doses to targeted and nontargeted cells for accurate dosimetry of all treatment regimens utilizing α particles, including RIT and others (e.g., Ra-223), especially for organs and tumors with heterogeneous radionuclide distributions. The aim of this study was to evaluate and characterize a novel single-particle digital autoradiography imager, the ionizing-radiation quantum imaging detector (iQID) camera, for use in α-RIT experiments. Methods: The iQID camera is a scintillator-based radiation detection system that images and identifies charged-particle and gamma-ray/x-ray emissions spatially and temporally on an event-by-event basis. It employs CCD-CMOS cameras and high-performance computing hardware for real-time imaging and activity quantification of tissue sections, approaching cellular resolutions. In this work, the authors evaluated its characteristics for α-particle imaging, including measurements of intrinsic detector spatial resolutions and background count rates at various detector configurations and quantification of activity distributions. The technique was assessed for quantitative imaging of astatine-211 ({sup 211}At) activity distributions in cryosections of murine and canine tissue samples. Results: The highest spatial resolution was measured at ∼20 μm full width at half maximum and the α-particle background was measured at a rate as low as (2.6 ± 0.5) × 10{sup −4} cpm/cm{sup 2} (40 mm diameter detector area

  2. The single scattering properties of the aerosol particles as aggregated spheres

    International Nuclear Information System (INIS)

    Wu, Y.; Gu, X.; Cheng, T.; Xie, D.; Yu, T.; Chen, H.; Guo, J.

    2012-01-01

    The light scattering and absorption properties of anthropogenic aerosol particles such as soot aggregates are complicated in the temporal and spatial distribution, which introduce uncertainty of radiative forcing on global climate change. In order to study the single scattering properties of anthorpogenic aerosol particles, the structures of these aerosols such as soot paticles and soot-containing mixtures with the sulfate or organic matter, are simulated using the parallel diffusion limited aggregation algorithm (DLA) based on the transmission electron microscope images (TEM). Then, the single scattering properties of randomly oriented aerosols, such as scattering matrix, single scattering albedo (SSA), and asymmetry parameter (AP), are computed using the superposition T-matrix method. The comparisons of the single scattering properties of these specific types of clusters with different morphological and chemical factors such as fractal parameters, aspect ratio, monomer radius, mixture mode and refractive index, indicate that these different impact factors can respectively generate the significant influences on the single scattering properties of these aerosols. The results show that aspect ratio of circumscribed shape has relatively small effect on single scattering properties, for both differences of SSA and AP are less than 0.1. However, mixture modes of soot clusters with larger sulfate particles have remarkably important effects on the scattering and absorption properties of aggregated spheres, and SSA of those soot-containing mixtures are increased in proportion to the ratio of larger weakly absorbing attachments. Therefore, these complex aerosols come from man made pollution cannot be neglected in the aerosol retrievals. The study of the single scattering properties on these kinds of aggregated spheres is important and helpful in remote sensing observations and atmospheric radiation balance computations.

  3. Approaches to single photon detection

    International Nuclear Information System (INIS)

    Thew, R.T.; Curtz, N.; Eraerds, P.; Walenta, N.; Gautier, J.-D.; Koller, E.; Zhang, J.; Gisin, N.; Zbinden, H.

    2009-01-01

    We present recent results on our development of single photon detectors, including: gated and free-running InGaAs/InP avalanche photodiodes (APDs); hybrid detection systems based on sum-frequency generation (SFG) and Si APDs-SFG-Si APDs; and SSPDs (superconducting single photon detectors), for telecom wavelengths; as well as SiPM (Silicon photomultiplier) detectors operating in the visible regime.

  4. Digital atom interferometer with single particle control on a discretized space-time geometry.

    Science.gov (United States)

    Steffen, Andreas; Alberti, Andrea; Alt, Wolfgang; Belmechri, Noomen; Hild, Sebastian; Karski, Michał; Widera, Artur; Meschede, Dieter

    2012-06-19

    Engineering quantum particle systems, such as quantum simulators and quantum cellular automata, relies on full coherent control of quantum paths at the single particle level. Here we present an atom interferometer operating with single trapped atoms, where single particle wave packets are controlled through spin-dependent potentials. The interferometer is constructed from a sequence of discrete operations based on a set of elementary building blocks, which permit composing arbitrary interferometer geometries in a digital manner. We use this modularity to devise a space-time analogue of the well-known spin echo technique, yielding insight into decoherence mechanisms. We also demonstrate mesoscopic delocalization of single atoms with a separation-to-localization ratio exceeding 500; this result suggests their utilization beyond quantum logic applications as nano-resolution quantum probes in precision measurements, being able to measure potential gradients with precision 5 x 10(-4) in units of gravitational acceleration g.

  5. On the efficiency of rocket-borne particle detection in the mesosphere

    Directory of Open Access Journals (Sweden)

    J. Hedin

    2007-07-01

    Full Text Available Meteoric smoke particles have been proposed as a key player in the formation and evolution of mesospheric phenomena. Despite their apparent importance still very little is known about these particles. Important questions concern the smoke number density and size distribution as a function of altitude as well as the fraction of charged particles. Sounding rockets are used to measure smoke in situ, but aerodynamics has remained a major challenge. Basically, the small smoke particles tend to follow the gas flow around the payload rather than reaching the detector if aerodynamics is not considered carefully in the detector design. So far only indirect evidence for the existence of meteoric smoke has been available from measurements of heavy charge carriers. Quantitative ways are needed that relate these measured particle population to the atmospheric particle population. This requires in particular knowledge about the size-dependent, altitude-dependent and charge-dependent detection efficiency for a given instrument. In this paper, we investigate the aerodynamics for a typical electrostatic detector design. We first quantify the flow field of the background gas, then introduce particles in the flow field and determine their trajectories around the payload structure. We use two different models to trace particles in the flow field, a Continuous motion model and a Brownian motion model. Brownian motion is shown to be of basic importance for the smallest particles. Detection efficiencies are determined for three detector designs, including two with ventilation holes to allow airflow through the detector. Results from this investigation show that rocket-borne smoke detection with conventional detectors is largely limited to altitudes above 75 km. The flow through a ventilated detector has to be relatively large in order to significantly improve the detection efficiency.

  6. Plasmonics and single-molecule detection in evaporated silver-island films

    Energy Technology Data Exchange (ETDEWEB)

    Moula, G.; Aroca, R.F. [Materials and Surface Science Group, University of Windsor, Ontario (Canada); Rodriguez-Oliveros, R.; Sanchez-Gil, J.A. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain); Albella, P. [Centro de Fisica de Materiales (CSIC-UPV/EHU) and Donostia International Physics Center (DIPC), 20018 Donostia, San Sebastian (Spain)

    2012-11-15

    The plasmonic origin of surface-enhanced Raman scattering (SERS) leads to the concept of hotspots and plasmon coupling that can be realized in the interstitial regions, or on specially engineered, silver and gold nanostructures. It is also possible to achieve spatial locations of high local field or hotspots on silver-island films (SIF) allowing single-molecule detection (SMD). When a single monomolecular layer coating the SIFs contains dye molecules dispersed in it, single-molecule impurities, (with an average of one hundred dye molecules in 1 {mu}m{sup 2}, which is the field of view of the micro-Raman system), SMD is observed as a rare statistical event. Here, the SMD results for silver-island films are presented, with the same nominal mass thickness, but differing in the localized surface plasmon resonance that is a function of the temperature of substrate during deposition. A blue-shifted plasmon can be seen as a decrease in plasmon coupling for deposition at higher temperature. A simple two-particle model for localized plasmon resonance coupling calculations, including the shape and substrate effects seems to explain the trend of observations. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Development of detection method for individual environmental particles containing alpha radioactive nuclides

    International Nuclear Information System (INIS)

    Esaka, Konomi; Yasuda, Kenichiro; Esaka, Fumitaka; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Nakayama, Shinichi

    2006-01-01

    Artificial radioactive nuclides have been emitted from various sources and have fallen on the surface of the earth as fine particles. Although the characterization of the individual fallout particles is very important, their analysis is difficult. The purpose of this study is to develop a new detection method for individual objective particles containing radioactive nuclides in the environment. The soil or sediment sample was confined in a plastic film and the locations of objective particles were identified with alpha tracks created in a solid-state detectors (BARYOTRAK, Fukuvi Chemical, Ltd) stuck to the both sides of the plastic film. A piece of the film containing the objective particle was cut with a nitrogen laser for following individual particle analysis. This procedure allowed us to detect the objective particle from innumerable number of particles in the environment and characterize the individual particles. (author)

  8. Single-particle properties from Kohn-Sham Green's functions

    International Nuclear Information System (INIS)

    Bhattacharyya, Anirban; Furnstahl, R.J.

    2005-01-01

    An effective action approach to Kohn-Sham density functional theory is used to illustrate how the exact Green's function can be calculated in terms of the Kohn-Sham Green's function. An example based on Skyrme energy functionals shows that single-particle Kohn-Sham spectra can be improved by adding sources used to construct the energy functional

  9. Single-particle characterization of ice-nucleating particles and ice particles residuals sampled by three different techniques

    Science.gov (United States)

    Kandler, Konrad; Worringen, Annette; Benker, Nathalie; Dirsch, Thomas; Mertes, Stephan; Schenk, Ludwig; Kästner, Udo; Frank, Fabian; Nillius, Björn; Bundke, Ulrich; Rose, Diana; Curtius, Joachim; Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Schneider, Johannes; Schmidt, Susan; Weinbruch, Stephan; Ebert, Martin

    2015-04-01

    During January/February 2013, at the High Alpine Research Station Jungfraujoch a measurement campaign was carried out, which was centered on atmospheric ice-nucleating particles (INP) and ice particle residuals (IPR). Three different techniques for separation of INP and IPR from the non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed phase clouds and allow for the analysis of the residuals. The combination of the Fast Ice Nucleus Chamber (FINCH) and the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated INP for analysis. Collected particles were analyzed by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine size, chemical composition and mixing state. All INP/IPR-separating techniques had considerable abundances (median 20 - 70 %) of instrumental contamination artifacts (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH+IN-PCVI: steel particles). Also, potential sampling artifacts (e.g., pure soluble material) occurred with a median abundance of separated by all three techniques. Soot was a minor contributor. Lead was detected in less than 10 % of the particles, of which the majority were internal mixtures with other particle types. Sea-salt and sulfates were identified by all three methods as INP/IPR. Most samples showed a maximum of the INP/IPR size distribution at 400 nm geometric diameter. In a few cases, a second super-micron maximum was identified. Soot/carbonaceous material and metal oxides were present mainly in the submicron range. ISI and FINCH yielded silicates and Ca-rich particles mainly with diameters above 1 µm, while the Ice-CVI also separated many submicron IPR. As strictly parallel sampling could not be performed, a part of the discrepancies between the different techniques may result from

  10. Amperometric detection of morphine based on poly(3,4-ethylenedioxythiophene) immobilized molecularly imprinted polymer particles prepared by precipitation polymerization

    International Nuclear Information System (INIS)

    Ho, K.-C.; Yeh, W.-M.; Tung, T.-S.; Liao, J.-Y.

    2005-01-01

    Molecular imprinting is a novel technique used for chiral separation, artificial antibodies, sensors, and assays. Typically, molecular imprinted polymers (MIPs) are monoliths with irregular shapes. However, microspherical shapes with more uniform size can be obtained by the method of precipitation polymerization, which offers a higher active surface area by manipulating its compositions. In this study, MIP particles for the target molecule, morphine, were synthesized using a precipitation polymerization method that is more facile than the previous one that produced a thermally polymerized bulk. The conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was utilized to immobilize the MIP particles onto the indium tin oxide (ITO) glass as a MIP/PEDOT-modified electrode. The sensitivity for the MIP/PEDOT-modified electrode with MIP particles was 41.63 μA/cm 2 mM, which is more sensitive than that with non-MIP particles or that of a single PEDOT film with no incorporated particles in detecting morphine ranging from 0.1 to 2 mM. The detection limit was 0.3 mM (S/N = 3). In addition, we presented that the modified electrode can discriminate codeine that plays an interfering species

  11. Development of automatic flaw detection systems for magnetic particle examination

    International Nuclear Information System (INIS)

    Shirai, T.; Kimura, J.; Amako, T.

    1988-01-01

    Utilizing a video camera and an image processor, development was carried out on automatic flaw detection and discrimination techniques for the purpose of achieving automated magnetic particle examination. Following this, fluorescent wet magnetic particle examination systems for blade roots and rotor grooves of turbine rotors and the non-fluorescent dry magnetic particle examination system for butt welds, were developed. This paper describes these automatic magnetic particle examination (MT) systems and the functional test results

  12. Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber

    International Nuclear Information System (INIS)

    Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan

    2008-01-01

    Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or 'interstitial' aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation

  13. Controlled and tunable polymer particles' production using a single microfluidic device

    Science.gov (United States)

    Amoyav, Benzion; Benny, Ofra

    2018-04-01

    Microfluidics technology offers a new platform to control liquids under flow in small volumes. The advantage of using small-scale reactions for droplet generation along with the capacity to control the preparation parameters, making microfluidic chips an attractive technology for optimizing encapsulation formulations. However, one of the drawback in this methodology is the ability to obtain a wide range of droplet sizes, from sub-micron to microns using a single chip design. In fact, typically, droplet chips are used for micron-dimension particles, while nanoparticles' synthesis requires complex chips design (i.e., microreactors and staggered herringbone micromixer). Here, we introduce the development of a highly tunable and controlled encapsulation technique, using two polymer compositions, for generating particles ranging from microns to nano-size using the same simple single microfluidic chip design. Poly(lactic-co-glycolic acid) (PLGA 50:50) or PLGA/polyethylene glycol polymeric particles were prepared with focused-flow chip, yielding monodisperse particle batches. We show that by varying flow rate, solvent, surfactant and polymer composition, we were able to optimize particles' size and decrease polydispersity index, using simple chip designs with no further related adjustments or costs. Utilizing this platform, which offers tight tuning of particle properties, could offer an important tool for formulation development and can potentially pave the way towards a better precision nanomedicine.

  14. Nanotip analysis for dielectrophoretic concentration of nanosized viral particles.

    Science.gov (United States)

    Yeo, Woon-Hong; Lee, Hyun-Boo; Kim, Jong-Hoon; Lee, Kyong-Hoon; Chung, Jae-Hyun

    2013-05-10

    Rapid and sensitive detection of low-abundance viral particles is strongly demanded in health care, environmental control, military defense, and homeland security. Current detection methods, however, lack either assay speed or sensitivity, mainly due to the nanosized viral particles. In this paper, we compare a dendritic, multi-terminal nanotip ('dendritic nanotip') with a single terminal nanotip ('single nanotip') for dielectrophoretic (DEP) concentration of viral particles. The numerical computation studies the concentration efficiency of viral particles ranging from 25 to 100 nm in radius for both nanotips. With DEP and Brownian motion considered, when the particle radius decreases by two times, the concentration time for both nanotips increases by 4-5 times. In the computational study, a dendritic nanotip shows about 1.5 times faster concentration than a single nanotip for the viral particles because the dendritic structure increases the DEP-effective area to overcome the Brownian motion. For the qualitative support of the numerical results, the comparison experiment of a dendritic nanotip and a single nanotip is conducted. Under 1 min of concentration time, a dendritic nanotip shows a higher sensitivity than a single nanotip. When the concentration time is 5 min, the sensitivity of a dendritic nanotip for T7 phage is 10(4) particles ml(-1). The dendritic nanotip-based concentrator has the potential for rapid identification of viral particles.

  15. Nanotip analysis for dielectrophoretic concentration of nanosized viral particles

    International Nuclear Information System (INIS)

    Yeo, Woon-Hong; Lee, Hyun-Boo; Kim, Jong-Hoon; Chung, Jae-Hyun; Lee, Kyong-Hoon

    2013-01-01

    Rapid and sensitive detection of low-abundance viral particles is strongly demanded in health care, environmental control, military defense, and homeland security. Current detection methods, however, lack either assay speed or sensitivity, mainly due to the nanosized viral particles. In this paper, we compare a dendritic, multi-terminal nanotip (‘dendritic nanotip’) with a single terminal nanotip (‘single nanotip’) for dielectrophoretic (DEP) concentration of viral particles. The numerical computation studies the concentration efficiency of viral particles ranging from 25 to 100 nm in radius for both nanotips. With DEP and Brownian motion considered, when the particle radius decreases by two times, the concentration time for both nanotips increases by 4–5 times. In the computational study, a dendritic nanotip shows about 1.5 times faster concentration than a single nanotip for the viral particles because the dendritic structure increases the DEP-effective area to overcome the Brownian motion. For the qualitative support of the numerical results, the comparison experiment of a dendritic nanotip and a single nanotip is conducted. Under 1 min of concentration time, a dendritic nanotip shows a higher sensitivity than a single nanotip. When the concentration time is 5 min, the sensitivity of a dendritic nanotip for T7 phage is 10 4 particles ml −1 . The dendritic nanotip-based concentrator has the potential for rapid identification of viral particles. (paper)

  16. Simulating Biomass Fast Pyrolysis at the Single Particle Scale

    Energy Technology Data Exchange (ETDEWEB)

    Ciesielski, Peter [National Renewable Energy Laboratory (NREL); Wiggins, Gavin [ORNL; Daw, C Stuart [ORNL; Jakes, Joseph E. [U.S. Forest Service, Forest Products Laboratory, Madison, Wisconsin, USA

    2017-07-01

    Simulating fast pyrolysis at the scale of single particles allows for the investigation of the impacts of feedstock-specific parameters such as particle size, shape, and species of origin. For this reason particle-scale modeling has emerged as an important tool for understanding how variations in feedstock properties affect the outcomes of pyrolysis processes. The origins of feedstock properties are largely dictated by the composition and hierarchical structure of biomass, from the microstructural porosity to the external morphology of milled particles. These properties may be accounted for in simulations of fast pyrolysis by several different computational approaches depending on the level of structural and chemical complexity included in the model. The predictive utility of particle-scale simulations of fast pyrolysis can still be enhanced substantially by advancements in several areas. Most notably, considerable progress would be facilitated by the development of pyrolysis kinetic schemes that are decoupled from transport phenomena, predict product evolution from whole-biomass with increased chemical speciation, and are still tractable with present-day computational resources.

  17. Detection of dark matter particles with low temperature phonon sensors

    International Nuclear Information System (INIS)

    Sadoulet, B.

    1988-03-01

    Taking as an example the development effort in Berkeley, the author discusses for nonspecialists (Astronomers and Particle Physicists) the promises of phonon sensing at low temperature for the detection of dark matter particles and the difficulties faced. 31 refs

  18. Detecting single-electron events in TEM using low-cost electronics and a silicon strip sensor.

    Science.gov (United States)

    Gontard, Lionel C; Moldovan, Grigore; Carmona-Galán, Ricardo; Lin, Chao; Kirkland, Angus I

    2014-04-01

    There is great interest in developing novel position-sensitive direct detectors for transmission electron microscopy (TEM) that do not rely in the conversion of electrons into photons. Direct imaging improves contrast and efficiency and allows the operation of the microscope at lower energies and at lower doses without loss in resolution, which is especially important for studying soft materials and biological samples. We investigate the feasibility of employing a silicon strip detector as an imaging detector for TEM. This device, routinely used in high-energy particle physics, can detect small variations in electric current associated with the impact of a single charged particle. The main advantages of using this type of sensor for direct imaging in TEM are its intrinsic radiation hardness and large detection area. Here, we detail design, simulation, fabrication and tests in a TEM of the front-end electronics developed using low-cost discrete components and discuss the limitations and applications of this technology for TEM.

  19. Dual-frequency magnetic particle imaging of the Brownian particle contribution

    Energy Technology Data Exchange (ETDEWEB)

    Viereck, Thilo, E-mail: t.viereck@tu-bs.de; Kuhlmann, Christian; Draack, Sebastian; Schilling, Meinhard; Ludwig, Frank

    2017-04-01

    Magnetic particle imaging (MPI) is an emerging medical imaging modality based on the non-linear response of magnetic nanoparticles to an exciting magnetic field. MPI has been recognized as a fast imaging technique with high spatial resolution in the mm range. For some applications of MPI, especially in the field of functional imaging, the determination of the particle mobility (Brownian rotation) is of great interest, as it enables binding detection in MPI. It also enables quantitative imaging in the presence of Brownian-dominated particles, which is otherwise implausible. Discrimination of different particle responses in MPI is possible via the joint reconstruction approach. In this contribution, we propose a dual-frequency acquisition scheme to enhance sensitivity and contrast in the detection of different particle mobilities compared to a standard single-frequency MPI protocol. The method takes advantage of the fact, that the magnetization response of the tracer is strongly frequency-dependent, i.e. for low excitation frequencies a stronger Brownian contribution is observed.

  20. Source characterization of urban particles from meat smoking activities in Chongqing, China using single particle aerosol mass spectrometry.

    Science.gov (United States)

    Chen, Yang; Wenger, John C; Yang, Fumo; Cao, Junji; Huang, Rujin; Shi, Guangming; Zhang, Shumin; Tian, Mi; Wang, Huanbo

    2017-09-01

    A Single Particle Aerosol Mass Spectrometer (SPAMS) was deployed in the urban area of Chongqing to characterize the particles present during a severe particulate pollution event that occurred in winter 2014-2015. The measurements were made at a time when residents engaged in traditional outdoor meat smoking activities to preserve meat before the Chinese Spring Festival. The measurement period was predominantly characterized by stagnant weather conditions, highly elevated levels of PM 2.5 , and low visibility. Eleven major single particle types were identified, with over 92.5% of the particles attributed to biomass burning emissions. Most of the particle types showed appreciable signs of aging in the stagnant air conditions. To simulate the meat smoking activities, a series of controlled smoldering experiments was conducted using freshly cut pine and cypress branches, both with and without wood logs. SPAMS data obtained from these experiments revealed a number of biomass burning particle types, including an elemental and organic carbon (ECOC) type that proved to be the most suitable marker for meat smoking activities. The traditional activity of making preserved meat in southwestern China is shown here to be a major source of particulate pollution. Improved measures to reduce emissions from the smoking of meat should be introduced to improve air quality in regions where smoking meat activity prevails. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Development of a Charged Particle Microbeam for Single-Particle Subcellular Irradiations at the MIT Laboratory for Accelerator Beam Application

    International Nuclear Information System (INIS)

    Yanch, Jacquelyn C.

    2004-01-01

    The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube

  2. Online single particle analysis of ice particle residuals from mountain-top mixed-phase clouds using laboratory derived particle type assignment

    Science.gov (United States)

    Schmidt, Susan; Schneider, Johannes; Klimach, Thomas; Mertes, Stephan; Schenk, Ludwig Paul; Kupiszewski, Piotr; Curtius, Joachim; Borrmann, Stephan

    2017-01-01

    In situ single particle analysis of ice particle residuals (IPRs) and out-of-cloud aerosol particles was conducted by means of laser ablation mass spectrometry during the intensive INUIT-JFJ/CLACE campaign at the high alpine research station Jungfraujoch (3580 m a.s.l.) in January-February 2013. During the 4-week campaign more than 70 000 out-of-cloud aerosol particles and 595 IPRs were analyzed covering a particle size diameter range from 100 nm to 3 µm. The IPRs were sampled during 273 h while the station was covered by mixed-phase clouds at ambient temperatures between -27 and -6 °C. The identification of particle types is based on laboratory studies of different types of biological, mineral and anthropogenic aerosol particles. The outcome of these laboratory studies was characteristic marker peaks for each investigated particle type. These marker peaks were applied to the field data. In the sampled IPRs we identified a larger number fraction of primary aerosol particles, like soil dust (13 ± 5 %) and minerals (11 ± 5 %), in comparison to out-of-cloud aerosol particles (2.4 ± 0.4 and 0.4 ± 0.1 %, respectively). Additionally, anthropogenic aerosol particles, such as particles from industrial emissions and lead-containing particles, were found to be more abundant in the IPRs than in the out-of-cloud aerosol. In the out-of-cloud aerosol we identified a large fraction of aged particles (31 ± 5 %), including organic material and secondary inorganics, whereas this particle type was much less abundant (2.7 ± 1.3 %) in the IPRs. In a selected subset of the data where a direct comparison between out-of-cloud aerosol particles and IPRs in air masses with similar origin was possible, a pronounced enhancement of biological particles was found in the IPRs.

  3. Single molecule experiments challenge the strict wave-particle dualism of light.

    Science.gov (United States)

    Greulich, Karl Otto

    2010-01-21

    Single molecule techniques improve our understanding of the photon and light. If the single photon double slit experiment is performed at the "single photon limit" of a multi-atom light source, faint light pulses with more than one photon hamper the interpretation. Single molecules, quantum dots or defect centres in crystals should be used as light source. "Single photon detectors" do not meet their promise-only "photon number resolving single photon detectors" do so. Particularly, the accumulation time argument, the only safe basis for the postulate of a strictly particle like photon, has so far not yet been verified.

  4. Single-crystalline spherical β-Ga2O3 particles: Synthesis, N-doping and photoluminescence properties

    International Nuclear Information System (INIS)

    Zhang, Tingting; Lin, Jing; Zhang, Xinghua; Huang, Yang; Xu, Xuewen; Xue, Yanming; Zou, Jin; Tang, Chengchun

    2013-01-01

    We report on the synthesis of single-crystalline spherical β-Ga 2 O 3 particles by a simple method in ambient atmosphere. No pre-treatment, catalyst, substrate, or gas flow was required during the synthesis process. The well-dispersed Ga 2 O 3 particles display uniform spherical morphology with an average diameter of ∼200 nm. Photoluminescence studies indicate that the Ga 2 O 3 particles exhibit a broad blue-green light emission and an interesting red light emission at room temperature. The red light emission can be further tuned by post-annealing of the particles in ammonia atmosphere. The present single-crystalline β-Ga 2 O 3 particles with spherical morphology, uniform sub-micrometer sizes and tunable light emission are envisaged to be of high promise for applications in white-LED phosphors and optoelectronic devices. -- Highlights: ► We prepared single-crystalline spherical β-Ga 2 O 3 particles in ambient atmosphere. ► The particles display uniform spherical morphology with an average diameter of ∼200 nm. ► The Ga 2 O 3 particles exhibit a broad blue-green light and an interesting red light emission. ► The red light emission can be further tuned by post-annealing of the particles

  5. An integrated micro-chip for rapid detection of magnetic particles

    KAUST Repository

    Gooneratne, Chinthaka P.; Liang, Cai; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    This paper proposes an integrated micro-chip for the manipulation and detection of magnetic particles (MPs). A conducting ring structure is used to manipulate MPs toward giant magnetoresistance(GMR) sensing elements for rapid detection

  6. Ionoluminescence analysis of glass scintillators and application to single-ion-hit real-time detection

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Akihito, E-mail: yokoyama.akihito@jaea.go.jp [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Kada, Wataru [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Satoh, Takahiro; Koka, Masashi [Takasaki Advanced Radiation Research Institute (TARRI), Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Shimada, Keisuke; Yokoata, Yuya; Miura, Kenta; Hanaizumi, Osamu [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)

    2016-03-15

    In this paper, we propose and test a real-time detection system for single-ion hits using mega-electronvolt (MeV)-heavy ions. The system was constructed using G2000 and G9 glass scintillators, as well as an electron-multiplying charge-coupled device (EMCCD) camera combined with an inverted microscope with a 10× objective lens. Commercially available G2000 and G9 glass scintillators, which have been reported to exhibit strong photoluminescence at 489, 543, 585, and 622 nm as a result of the Tb{sup 3+} f–f transition, were employed for highly accurate ionized particle detection. The EMCCD camera had a resolution of 512 × 512 pixels, each with a size of 16 μm × 16 μm, and a maximum linear gain of 8 × 10{sup 5} electrons. For 260-MeV Ne, 3 ion hits/s were detected by our system. The intensity of the ionoluminescence (IL) peak induced by the heavy ions was 140 times the noise intensity. In contrast, the luminous diameter at the full width at half maximum (FWHM) in both the horizontal and vertical directions was calculated to be approximately 4.5 μm. These results suggest that our detection system can accurately detect single-ion hits with a diameter of the order of 1 μm.

  7. Characterizing physical properties and heterogeneous chemistry of single particles in air using optical trapping-Raman spectroscopy

    Science.gov (United States)

    Gong, Z.; Wang, C.; Pan, Y. L.; Videen, G.

    2017-12-01

    Heterogeneous reactions of solid particles in a gaseous environment are of increasing interest; however, most of the heterogeneous chemistry studies of airborne solids were conducted on particle ensembles. A close examination on the heterogeneous chemistry between single particles and gaseous-environment species is the key to elucidate the fundamental mechanisms of hydroscopic growth, cloud nuclei condensation, secondary aerosol formation, etc., and reduce the uncertainty of models in radiative forcing, climate change, and atmospheric chemistry. We demonstrate an optical trapping-Raman spectroscopy (OT-RS) system to study the heterogeneous chemistry of the solid particles in air at single-particle level. Compared to other single-particle techniques, optical trapping offers a non-invasive, flexible, and stable method to isolate single solid particle from substrates. Benefited from two counter-propagating hollow beams, the optical trapping configuration is adaptive to trap a variety of particles with different materials from inorganic substitution (carbon nanotubes, silica, etc.) to organic, dye-doped polymers and bioaerosols (spores, pollen, etc.), with different optical properties from transparent to strongly absorbing, with different sizes from sub-micrometers to tens of microns, or with distinct morphologies from loosely packed nanotubes to microspheres and irregular pollen grains. The particles in the optical trap may stay unchanged, surface degraded, or optically fragmented according to different laser intensity, and their physical and chemical properties are characterized by the Raman spectra and imaging system simultaneously. The Raman spectra is able to distinguish the chemical compositions of different particles, while the synchronized imaging system can resolve their physical properties (sizes, shapes, morphologies, etc.). The temporal behavior of the trapped particles also can be monitored by the OT-RS system at an indefinite time with a resolution from

  8. Ionization particle detector

    International Nuclear Information System (INIS)

    Ried, L.

    1982-01-01

    A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source

  9. Particles Produced in Association with High Transverse Momentum Single Photons and $\\pi^0$s in Hadronic Collision

    Energy Technology Data Exchange (ETDEWEB)

    Sinanidis, Alexandros Pericles [Northeastern U.

    1989-01-01

    The charged and neutral particles produced in association with high transverse momentum ($Pr_{\\tau}$ > 5.0 GeV /c) photons ($\\gamma$) and neutral pions ($\\pi^0$) in p(Cu+Be) and $\\pi^-$(cu+Be) collisions at vs = 31.5 GeV are studied in this thesis. It was observed that 1) The relative rapidity of the two highest Pr recoiling particles in the events have a jet - like structure. 2) The relative rapidity of the single $\\gamma$ (or $\\pi^0$ ) and the highest $P_{\\tau}$ charged particle accompanying the single $\\gamma$ (or $\\pi^0$ ) show that the high $P_{\\tau} \\pi^0$ events have a jet - like structure in the trigger hemisphere whereas the high $P_{\\tau}$ single $\\gamma$ events do not. 3) The angular distributions of the particles produced in the reactions show that high $P_{\\tau} \\pi^0$s are accompanied by other particles, whereas high $P_{\\tau}$ single photons are relatively isolated. 4) The fragmentation distributions of the recoiling particles from the high $P_{\\tau}$ single photons and $\\pi^0$s are consistent with the measurements of other experiments. 5) The recoiling particles are consistent with the fragmentation of either a quark or a gluon according to the QCD (Quantum Chromodynamics). In summary, particles produced in association with high transverse momentum single photons and $\\pi^0$s in hadronic collisions have been measured and their properties are in good agreement with the predictions of the parton model and those of QCD

  10. A database of microwave and sub-millimetre ice particle single scattering properties

    Science.gov (United States)

    Ekelund, Robin; Eriksson, Patrick

    2016-04-01

    Ice crystal particles are today a large contributing factor as to why cold-type clouds such as cirrus remain a large uncertainty in global climate models and measurements. The reason for this is the complex and varied morphology in which ice particles appear, as compared to liquid droplets with an in general spheroidal shape, thus making the description of electromagnetic properties of ice particles more complicated. Single scattering properties of frozen hydrometers have traditionally been approximated by representing the particles as spheres using Mie theory. While such practices may work well in radio applications, where the size parameter of the particles is generally low, comparisons with measurements and simulations show that this assumption is insufficient when observing tropospheric cloud ice in the microwave or sub-millimetre regions. In order to assist the radiative transfer and remote sensing communities, a database of single scattering properties of semi-realistic particles is being produced. The data is being produced using DDA (Discrete Dipole Approximation) code which can treat arbitrarily shaped particles, and Tmatrix code for simpler shapes when found sufficiently accurate. The aim has been to mainly cover frequencies used by the upcoming ICI (Ice Cloud Imager) mission with launch in 2022. Examples of particles to be included are columns, plates, bullet rosettes, sector snowflakes and aggregates. The idea is to treat particles with good average optical properties with respect to the multitude of particles and aggregate types appearing in nature. The database will initially only cover macroscopically isotropic orientation, but will eventually also include horizontally aligned particles. Databases of DDA particles do already exist with varying accessibility. The goal of this database is to complement existing data. Regarding the distribution of the data, the plan is that the database shall be available in conjunction with the ARTS (Atmospheric

  11. Single charging events on colloidal particles in a nonpolar liquid with surfactant

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Brans, Toon; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-01-01

    Electrical charging of colloidal particles in nonpolar liquids due to surfactant additives is investigated intensively, motivated by its importance in a variety of applications. Most methods rely on average electrophoretic mobility measurements of many particles, which provide only indirect information on the charging mechanism. In the present work, we present a method that allows us to obtain direct information on the charging mechanism, by measuring the charge fluctuations on individual particles with a precision higher than the elementary charge using optical trapping electrophoresis. We demonstrate the capabilities of the method by studying the influence of added surfactant OLOA 11000 on the charging of single colloidal PMMA particles in dodecane. The particle charge and the frequency of charging events are investigated both below and above the critical micelle concentration (CMC) and with or without applying a DC offset voltage. It is found that at least two separate charging mechanisms are present below the critical micelle concentration. One mechanism is a process where the particle is stripped from negatively charged ionic molecules. An increase in the charging frequency with increased surfactant concentration suggests a second mechanism that involves single surfactant molecules. Above the CMC, neutral inverse micelles can also be involved in the charging process.

  12. Probing Single Nanometer-scale Particles with Scanning Tunneling Microscopy and Spectroscopies

    International Nuclear Information System (INIS)

    McCarty, G.S.; Love, J.C.; Kushmerick, J.G.; Charles, L.F.; Keating, C.D.; Toleno, B.J.; Lyn, M.E.; Castleman, A.W.; Natan, M.J.; Weiss, P.S.

    1999-01-01

    Scanning tunneling microscopy can be used to isolate single particles on surfaces for further study. Local optical and electronic properties coupled with topographic information collected by the scanning tunneling microscope (STM) give insight into the intrinsic properties of the species under study. Since each spectroscopic measurement is done on a single particle, each sample is 'monodisperse', regardless of the degree of heterogeneity of the original preparation. We illustrate this with three example systems - a metal cluster of known atomic structure, metal nanoparticles dispersed from colloid suspensions, and metallocarbohedrenes (Met-Cars) deposited with other reaction products. Au and Ag nanoparticles were imaged using a photon emission STM. The threshold voltage, the lowest bias voltage at which photons are produced, was determined for Au nanoparticles. Electronic spectra of small clusters of Ni atoms on MoS 2 were recorded. Preliminary images of Zr-based Met-Car-containing soot were obtained on Au and MoS 2 substrates and partial electronic spectra were recorded of these possible Met-Car particles

  13. Building the Nanoplasmonics Toolbox Through Shape Modeling and Single Particle Optical Studies

    Science.gov (United States)

    Ringe, Emilie

    Interest in nanotechnology is driven by unprecedented properties tailorability, achievable by controlling particle structure and composition. Unlike bulk components, minute changes in size and shape affect the optical and electronic properties of nanoparticles. Characterization of such structure-function relationships and better understanding of structure control mechanisms is crucial to the development of applications such as plasmonic sensors and devices. The objective of the current research is thus twofold: to theoretically predict and understand how shape is controlled by synthesis conditions, and to experimentally unravel, through single particle studies, how shape, composition, size, and surrounding environment affect plasmonic properties in noble metal particles. Quantitative, predictive rules and fundamental knowledge obtained from this research contributes to the "nanoplasmonics toolbox", a library designed to provide scientists and engineers the tools to create and optimize novel nanotechnology applications. In this dissertation, single particle approaches are developed and used to unravel the effects of size, shape, substrate, aggregation state and surrounding environment on the optical response of metallic nanoparticles. Ag and Au nanocubes on different substrates are first presented, followed by the discussion of the concept of plasmon length, a universal parameter to describe plasmon energy for a variety of particle shapes and plasmon modes. Plasmonic sensing (both refractive index sensing and surface-enhanced Raman spectroscopy) and polarization effects are then studied at the single particle level. In the last two Chapters, analytical shape models based on the Wulff construction provide unique modeling tools for alloy and kinetically grown nanoparticles. The former reveals a size-dependence of the shape of small alloy particles (such as those used in catalysis) because of surface segregation, while the latter uniquely models the shape of many

  14. The role of nanotechnology in single-cell detection: a review.

    Science.gov (United States)

    Wang, Changling; Zhang, Yuxiang; Xia, Mingdian; Zhu, Xingxi; Qi, Shitao; Shen, Huaqiang; Liu, Tiebing; Tang, Liming

    2014-10-01

    Biological processes in single cells, such as signal transduction, DNA duplication, and protein synthesis and trafficking, occur in subcellular compartments at nanoscale level. Achieving high spatial-temporal resolution, high sensitivity, and high specificity in single-cell detection poses a great challenge. Nanotechnology, which has been widely applied in the fields of medicine, electronics, biomaterials, and energy production, has the potential to provide solutions for single-cell detection. Here we present a review of the use of nanotechnology in single-cell detection over the past two decades. First, we review the main areas of scientific interest, including morphology, ion concentration, DNA, RNA, protein, intracellular temperature, elements, and mechanical properties. Second, four categories of application of nanotechnology to single-cell detection are described: nanomanipulation, nanodevices, nanomaterials as labels, and nano Secondary ion mass spectrometry. Finally, the prospects and future trends in single-cell detection and analysis are discussed.

  15. Magnetization Reversal Process of Single Crystal α-Fe Containing a Nonmagnetic Particle

    International Nuclear Information System (INIS)

    Li Yi; Xu Ben; Li Qiu-Lin; Liu Wei; Hu Shen-Yang; Li Yu-Lan

    2015-01-01

    The magnetization reversal process and hysteresis loops in a single crystal α-iron with nonmagnetic particles are simulated in this work based on the Landau—Lifshitz—Gilbert equation. The evolutions of the magnetic domain morphology are studied, and our analyses show that the magnetization reversal process is affected by the interaction between the moving domain wall and the existing nonmagnetic particles. This interaction strongly depends on the size of the particles, and it is found that particles with a particular size contribute the most to magnetic hardening. (paper)

  16. Single Molecule Experiments Challenge the Strict Wave-Particle Dualism of Light

    Directory of Open Access Journals (Sweden)

    Karl Otto Greulich

    2010-01-01

    Full Text Available Single molecule techniques improve our understanding of the photon and light. If the single photon double slit experiment is performed at the “single photon limit” of a multi-atom light source, faint light pulses with more than one photon hamper the interpretation. Single molecules, quantum dots or defect centres in crystals should be used as light source. “Single photon detectors” do not meet their promise―only “photon number resolving single photon detectors” do so. Particularly, the accumulation time argument, the only safe basis for the postulate of a strictly particle like photon, has so far not yet been verified.

  17. Single-particle Analyses of Compositions, Morphology, and Viscosity of Aerosol Particles Collected During GoAmazon2014

    Science.gov (United States)

    Adachi, K.; Gong, Z.; Bateman, A. P.; Martin, S. T.; Cirino, G. G.; Artaxo, P.; Sedlacek, A. J., III; Buseck, P. R.

    2014-12-01

    Single-particle analysis using transmission electron microscopy (TEM) shows composition and morphology of individual aerosol particles collected during the GoAmazon2014 campaign. These TEM results indicate aerosol types and mixing states, both of which are important for evaluating particle optical properties and cloud condensation nuclei activity. The samples were collected at the T3 site, which is located in the Amazon forest with influences from the urban pollution plume from Manaus. Samples were also collected from the T0 site, which is in the middle of the jungle with minimal to no influences of anthropogenic sources. The aerosol particles mainly originated from 1) anthropogenic pollution (e.g., nanosphere soot, sulfate), 2) biogenic emissions (e.g., primary biogenic particles, organic aerosols), and 3) long-range transport (e.g., sea salts). We found that the biogenic organic aerosol particles contain homogeneously distributed potassium. Particle viscosity is important for evaluating gas-particle interactions and atmospheric chemistry for the particles. Viscosity can be estimated from the rebounding behavior at controlled relative humidities, i.e., highly viscous particles display less rebound on a plate than low-viscosity particles. We collected 1) aerosol particles from a plate (non-rebounded), 2) those that had rebounded from the plate and were then captured onto an adjacent sampling plate, and 3) particles from ambient air using a separate impactor sampler. Preliminary results show that more than 90% of non-rebounded particles consisted of nanosphere soot with or without coatings. The coatings mostly consisted of organic matter. Although rebounded particles also contain nanosphere soot (number fraction 64-69%), they were mostly internally mixed with sulfate, organic matter, or their mixtures. TEM tilted images suggested that the rebounded particles were less deformed on the substrate, whereas the non-rebounded particles were more deformed, which could

  18. Basic Evidence and Properties of Single-Particle States in Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cindro, N. [Institute ' ' Rudjer Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1970-07-15

    1. Introduction: the shell-model orbitals; 2. Information about single-particle orbitals: a critical evaluation; 3. Experimental evidence: 3.1. The lead region; 3.2. The calcium region; 3.3. Nuclei far from closed shells; 4. Conclusion. (author)

  19. Phase-coexistence simulations of fluid mixtures by the Markov Chain Monte Carlo method using single-particle models

    KAUST Repository

    Li, Jun

    2013-09-01

    We present a single-particle Lennard-Jones (L-J) model for CO2 and N2. Simplified L-J models for other small polyatomic molecules can be obtained following the methodology described herein. The phase-coexistence diagrams of single-component systems computed using the proposed single-particle models for CO2 and N2 agree well with experimental data over a wide range of temperatures. These diagrams are computed using the Markov Chain Monte Carlo method based on the Gibbs-NVT ensemble. This good agreement validates the proposed simplified models. That is, with properly selected parameters, the single-particle models have similar accuracy in predicting gas-phase properties as more complex, state-of-the-art molecular models. To further test these single-particle models, three binary mixtures of CH4, CO2 and N2 are studied using a Gibbs-NPT ensemble. These results are compared against experimental data over a wide range of pressures. The single-particle model has similar accuracy in the gas phase as traditional models although its deviation in the liquid phase is greater. Since the single-particle model reduces the particle number and avoids the time-consuming Ewald summation used to evaluate Coulomb interactions, the proposed model improves the computational efficiency significantly, particularly in the case of high liquid density where the acceptance rate of the particle-swap trial move increases. We compare, at constant temperature and pressure, the Gibbs-NPT and Gibbs-NVT ensembles to analyze their performance differences and results consistency. As theoretically predicted, the agreement between the simulations implies that Gibbs-NVT can be used to validate Gibbs-NPT predictions when experimental data is not available. © 2013 Elsevier Inc.

  20. Single Particle Soot Photometer intercomparison at the AIDA chamber

    Directory of Open Access Journals (Sweden)

    M. Laborde

    2012-12-01

    Full Text Available Soot particles, consisting of black carbon (BC, organic carbon (OC, inorganic salts, and trace elements, are emitted into the atmosphere during incomplete combustion. Accurate measurements of atmospheric BC are important as BC particles cause adverse health effects and impact the climate.

    Unfortunately, the accurate measurement of the properties and mass concentrations of BC particles remains difficult. The Single Particle Soot Photometer (SP2 can contribute to improving this situation by measuring the mass of refractory BC in individual particles as well as its mixing state.

    Here, the results of the first detailed SP2 intercomparison, involving 6 SP2s from 6 different research groups, are presented, including the most evolved data products that can presently be calculated from SP2 measurements.

    It was shown that a detection efficiency of almost 100% down to 1 fg BC per particle can readily be achieved, and that this limit can be pushed down to ∼0.2 fg BC with optimal SP2 setup. Number and mass size distributions of BC cores agreed within ±5% and ±10%, respectively, in between the SP2s, with larger deviations in the range below 1 fg BC.

    The accuracy of the SP2's mass concentration measurement depends on the calibration material chosen. The SP2 has previously been shown to be equally sensitive to fullerene soot and ambient BC from sources where fossil fuel was dominant and less sensitive to fullerene soot than to Aquadag. Fullerene soot was therefore chosen as the standard calibration material by the SP2 user community; however, many data sets rely solely on Aquadag calibration measurements. The difference in SP2 sensitivity was found to be almost equal (fullerene soot to Aquadag response ratio of ∼0.75 at 8.9 fg BC for all SP2s. This allows the calculation of a fullerene soot equivalent calibration curve from a measured Aquadag calibration, when no fullerene soot calibration is available. It could be

  1. Ergodicity of a single particle confined in a nanopore

    DEFF Research Database (Denmark)

    Bernardi, S.; Hansen, Jesper Schmidt; Frascolli, F.

    2012-01-01

    -ergodic component of the phase space for energy levels typical of experiments, is surprisingly small, i.e. we conclude that the ergodic hypothesis is a reasonable approximation even for a single particle trapped in a nanopore. Due to the numerical scope of this work, our focus will be the onset of ergodic behavior...

  2. Tuneable graphene nanopores for single biomolecule detection.

    Science.gov (United States)

    Al-Dirini, Feras; Mohammed, Mahmood A; Hossain, Md Sharafat; Hossain, Faruque M; Nirmalathas, Ampalavanapillai; Skafidas, Efstratios

    2016-05-21

    Solid-state nanopores are promising candidates for next generation DNA and protein sequencing. However, once fabricated, such devices lack tuneability, which greatly restricts their biosensing capabilities. Here we propose a new class of solid-state graphene-based nanopore devices that exhibit a unique capability of self-tuneability, which is used to control their conductance, tuning it to levels comparable to the changes caused by the translocation of a single biomolecule, and hence, enabling high detection sensitivities. Our presented quantum simulation results suggest that the smallest amino acid, glycine, when present in water and in an aqueous saline solution can be detected with high sensitivity, up to a 90% change in conductance. Our results also suggest that passivating the device with nitrogen, making it an n-type device, greatly enhances its sensitivity, and makes it highly sensitive to not only the translocation of a single biomolecule, but more interestingly to intramolecular electrostatics within the biomolecule. Sensitive detection of the carboxyl group within the glycine molecule, which carries a charge equivalent to a single electron, is achieved with a conductance change that reaches as high as 99% when present in an aqueous saline solution. The presented findings suggest that tuneable graphene nanopores, with their capability of probing intramolecular electrostatics, could pave the way towards a new generation of single biomolecule detection devices.

  3. Single Particle Differentiation through 2D Optical Fiber Trapping and Back-Scattered Signal Statistical Analysis: An Exploratory Approach.

    Science.gov (United States)

    Paiva, Joana S; Ribeiro, Rita S R; Cunha, João P S; Rosa, Carla C; Jorge, Pedro A S

    2018-02-27

    Recent trends on microbiology point out the urge to develop optical micro-tools with multifunctionalities such as simultaneous manipulation and sensing. Considering that miniaturization has been recognized as one of the most important paradigms of emerging sensing biotechnologies, optical fiber tools, including Optical Fiber Tweezers (OFTs), are suitable candidates for developing multifunctional small sensors for Medicine and Biology. OFTs are flexible and versatile optotools based on fibers with one extremity patterned to form a micro-lens. These are able to focus laser beams and exert forces onto microparticles strong enough (piconewtons) to trap and manipulate them. In this paper, through an exploratory analysis of a 45 features set, including time and frequency-domain parameters of the back-scattered signal of particles trapped by a polymeric lens, we created a novel single feature able to differentiate synthetic particles (PMMA and Polystyrene) from living yeasts cells. This single statistical feature can be useful for the development of label-free hybrid optical fiber sensors with applications in infectious diseases detection or cells sorting. It can also contribute, by revealing the most significant information that can be extracted from the scattered signal, to the development of a simpler method for particles characterization (in terms of composition, heterogeneity degree) than existent technologies.

  4. Discrimination capability of avalanche counters detecting different ionizing particles

    International Nuclear Information System (INIS)

    Prete, G.; Viesti, G.; Padua Univ.

    1985-01-01

    The discrimination capability of avalanche counters to detect different ionizing particles has been studied using a 252 Cf source. Pulse height, pulse-height resolution and timing properties have been measured as a function of the reduced applied voltage for parallel-plate and parallel-grid avalanche counters. At the highest applied voltages, space charge effects shift the pulse-height signal of the avalanche counter away from being linearly proportional to the stopping power of the detected particles and cause the pulse-height resolution to deteriorate. To optimize the avalanche counter capability, without loss of time resolution, it appears better to operate the detector at voltages well below the breakdown threshold. Measurements with 32 S ions are also reported. (orig.)

  5. Single particle inclusive spectra resulting from the collision of relativistic protons, deuterons, alpha particles, and carbon ions with nuclei

    International Nuclear Information System (INIS)

    Papp, J.

    1975-05-01

    The yields of positive and negative particles resulting from the collision of 1.05 GeV/nucleon and 2.1 GeV/nucleon protons, deuterons, alpha particles, and 1.05 GeV/nucleon carbon nuclei with various targets have been measured. Single particle inclusive cross sections for production of π + , π - , p, d, 3 H, 3 He, and 4 He at 2.5 0 (lab) were obtained. How the results bear on the concepts of limiting fragmentation and scaling, the structure of the alpha particle and deuteron, and the possibility of ''coherent'' production of pions by heavy ions are discussed. (U.S.)

  6. Geometric effects in alpha particle detection from distributed air sources

    International Nuclear Information System (INIS)

    Gil, L.R.; Leitao, R.M.S.; Marques, A.; Rivera, A.

    1994-08-01

    Geometric effects associated to detection of alpha particles from distributed air sources, as it happens in Radon and Thoron measurements, are revisited. The volume outside which no alpha particle may reach the entrance window of the detector is defined and determined analytically for rectangular and cylindrical symmetry geometries. (author). 3 figs

  7. Understanding particle size and distance driven competition of interparticle interactions and effective single-particle anisotropy

    Czech Academy of Sciences Publication Activity Database

    Pacáková, Barbara; Mantlíková, Alice; Nižňanský, D.; Kubíčková, Simona; Vejpravová, Jana

    2016-01-01

    Roč. 28, č. 20 (2016), 1-11, č. článku 206004. ISSN 0953-8984 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:68378271 Keywords : magnetic nanoparticles * single-particle anisotropy * dipolar energy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.649, year: 2016

  8. Optimal noise reduction in 3D reconstructions of single particles using a volume-normalized filter

    Science.gov (United States)

    Sindelar, Charles V.; Grigorieff, Nikolaus

    2012-01-01

    The high noise level found in single-particle electron cryo-microscopy (cryo-EM) image data presents a special challenge for three-dimensional (3D) reconstruction of the imaged molecules. The spectral signal-to-noise ratio (SSNR) and related Fourier shell correlation (FSC) functions are commonly used to assess and mitigate the noise-generated error in the reconstruction. Calculation of the SSNR and FSC usually includes the noise in the solvent region surrounding the particle and therefore does not accurately reflect the signal in the particle density itself. Here we show that the SSNR in a reconstructed 3D particle map is linearly proportional to the fractional volume occupied by the particle. Using this relationship, we devise a novel filter (the “single-particle Wiener filter”) to minimize the error in a reconstructed particle map, if the particle volume is known. Moreover, we show how to approximate this filter even when the volume of the particle is not known, by optimizing the signal within a representative interior region of the particle. We show that the new filter improves on previously proposed error-reduction schemes, including the conventional Wiener filter as well as figure-of-merit weighting, and quantify the relationship between all of these methods by theoretical analysis as well as numeric evaluation of both simulated and experimentally collected data. The single-particle Wiener filter is applicable across a broad range of existing 3D reconstruction techniques, but is particularly well suited to the Fourier inversion method, leading to an efficient and accurate implementation. PMID:22613568

  9. Inequivalence of single-particle and population lifetimes in a cuprate superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuolong [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Sobota, J. A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leuenberger, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); He, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Hashimoto, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lu, D. H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Eisaki, H. [National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan); Kirchmann, P. S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)

    2015-06-15

    We study optimally doped Bi-2212 (Tc=96 K) using femtosecond time- and angle-resolved photoelectron spectroscopy. Energy-resolved population lifetimes are extracted and compared with single-particle lifetimes measured by equilibrium photoemission. The population lifetimes deviate from the single-particle lifetimes in the low excitation limit by 1–2 orders of magnitude. Fundamental considerations of electron scattering unveil that these two lifetimes are in general distinct, yet for systems with only electron-phonon scattering they should converge in the low-temperature, low-fluence limit. As a result, the qualitative disparity in our data, even in this limit, suggests that scattering channels beyond electron-phonon interactions play a significant role in the electron dynamics of cuprate superconductors.

  10. Single-particle model of a strongly driven, dense, nanoscale quantum ensemble

    Science.gov (United States)

    DiLoreto, C. S.; Rangan, C.

    2018-01-01

    We study the effects of interatomic interactions on the quantum dynamics of a dense, nanoscale, atomic ensemble driven by a strong electromagnetic field. We use a self-consistent, mean-field technique based on the pseudospectral time-domain method and a full, three-directional basis to solve the coupled Maxwell-Liouville equations. We find that interatomic interactions generate a decoherence in the state of an ensemble on a much faster time scale than the excited-state lifetime of individual atoms. We present a single-particle model of the driven, dense ensemble by incorporating interactions into a dephasing rate. This single-particle model reproduces the essential physics of the full simulation and is an efficient way of rapidly estimating the collective dynamics of a dense ensemble.

  11. Single-Particle Spin-Orbit Splittings in Nuclei

    OpenAIRE

    Kazuhiko, ANDO; Hiroharu, BANDO; Department of Physics, Kyoto University; Division of Mathematical Physics, Fukui University

    1981-01-01

    Single-particle spin-orbit splittings (Δ^) in ^O and ^Ca nuclei are evaluated within the framework of the effective interaction theory by employing the Reid soft-core potential and meson-exchange three-body forces (TBF). Among the two-body force contributions, the Pauli-rearrangement effect on Δ^ is studied with special care. The TBF contribution to Δ^ is found to be significant. The G-matrix, the second-order pauli-rearrangement and the TBF contribute to Δ^ by the amount of ~1/2, ~1/5 and ~1...

  12. Detecting chaos in particle accelerators through the frequency map analysis method.

    Science.gov (United States)

    Papaphilippou, Yannis

    2014-06-01

    The motion of beams in particle accelerators is dominated by a plethora of non-linear effects, which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data.

  13. SU-F-J-197: A Novel Intra-Beam Range Detection and Adaptation Strategy for Particle Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, M; Jiang, S; Shao, Y; Lu, W [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: In-vivo range detection/verification is crucial in particle therapy for effective and safe delivery. The state-of-art techniques are not sufficient for in-vivo on-line range verification due to conflicts among patient dose, signal statistics and imaging time. We propose a novel intra-beam range detection and adaptation strategy for particle therapy. Methods: This strategy uses the planned mid-range spots as probing beams without adding extra radiation to patients. Such choice of probing beams ensures the Bragg peaks to remain inside the tumor even with significant range variation from the plan. It offers sufficient signal statistics for in-beam positron emission tomography (PET) due to high positron activity of therapeutic dose. The probing beam signal can be acquired and reconstructed using in-beam PET that allows for delineation of the Bragg peaks and detection of range shift with ease of detection enabled by single-layered spots. If the detected range shift is within a pre-defined tolerance, the remaining spots will be delivered as the original plan. Otherwise, a fast re-optimization using range-shifted beamlets and accounting for the probing beam dose is applied to consider the tradeoffs posed by the online anatomy. Simulated planning and delivery studies were used to demonstrate the effectiveness of the proposed techniques. Results: Simulations with online range variations due to shifts of various foreign objects into the beam path showed successful delineation of the Bragg peaks as a result of delivering probing beams. Without on-line delivery adaptation, dose distribution was significantly distorted. In contrast, delivery adaptation incorporating detected range shift recovered well the planned dose. Conclusion: The proposed intra-beam range detection and adaptation utilizing the planned mid-range spots as probing beams, which illuminate the beam range with strong and accurate PET signals, is a safe, practical, yet effective approach to address range

  14. Atomic Particle Detection

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1970-01-01

    This booklet tells how scientists observe the particles and electromagnetic radiation that emerges from an atomic nucleus. The equipment used falls into two general categories: counters which count each particle as it passes by, and track detectors, which make a photographic record of the particle's track.

  15. Portable instrument for selectively detecting alpha-particles derived from radon

    International Nuclear Information System (INIS)

    Chapuis, A.M.; DaJlevic, D.

    1975-01-01

    A portable instrument of the pocket type designed primarily for monitoring atmospheric contamination in uranium mines by selectively detecting the α-particles emitted simultaneously by the daughter products of radon, namely radium A and radium C' is described. The instrument comprises in combination a tube containing a suction fan for drawing external air through a filter which retains the α-emitting aerosols, a detector in which the α-particles corresponding to the respective energies of the α-emissions of radium A and of radium C' are detected separately, and two collimators placed between the filter and the detector

  16. The use of Nanotrap particles in the enhanced detection of Rift Valley fever virus nucleoprotein.

    Directory of Open Access Journals (Sweden)

    Nazly Shafagati

    Full Text Available Rift Valley fever virus (RVFV is a highly pathogenic arthropod-borne virus that has a detrimental effect on both livestock and human populations. While there are several diagnostic methodologies available for RVFV detection, many are not sensitive enough to diagnose early infections. Furthermore, detection may be hindered by high abundant proteins such as albumin. Previous findings have shown that Nanotrap particles can be used to significantly enhance detection of various small analytes of low abundance. We have expanded upon this repertoire to show that this simple and efficient sample preparation technology can drastically improve the detection of the RVFV nucleoprotein (NP, the most abundant and widely used viral protein for RVFV diagnostics.After screening multiple Nanotrap particle architectures, we found that one particle, NT45, was optimal for RVFV NP capture, as demonstrated by western blotting. NT45 significantly enhanced detection of the NP at levels undetectable without the technology. Importantly, we demonstrated that Nanotrap particles are capable of concentrating NP in a number of matrices, including infected cell lysates, viral supernatants, and animal sera. Specifically, NT45 enhanced detection of NP at various viral titers, multiplicity of infections, and time points. Our most dramatic results were observed in spiked serum samples, where high abundance serum proteins hindered detection of NP without Nanotrap particles. Nanotrap particles allowed for sample cleanup and subsequent detection of RVFV NP. Finally, we demonstrated that incubation of our samples with Nanotrap particles protects the NP from degradation over extended periods of time (up to 120 hours and at elevated temperatures (at 37ºC.This study demonstrates that Nanotrap particles are capable of drastically lowering the limit of detection for RVFV NP by capturing, concentrating, and preserving RVFV NP in clinically relevant matrices. These studies can be extended to

  17. Sensitive Detection of Small Particles in Fluids Using Optical Fiber Tip with Dielectrophoresis

    Directory of Open Access Journals (Sweden)

    Yi-Hsin Tai

    2016-02-01

    Full Text Available This work presents using a tapered fiber tip coated with thin metallic film to detect small particles in water with high sensitivity. When an AC voltage applied to the Ti/Al coated fiber tip and indium tin oxide (ITO substrate, a gradient electric field at the fiber tip induced attractive/repulsive force to suspended small particles due to the frequency-dependent dielectrophoresis (DEP effect. Such DEP force greatly enhanced the concentration of the small particles near the tip. The increase of the local concentration also increased the scattering of surface plasmon wave near the fiber tip. Combined both DEP effect and scattering optical near-field, we show the detection limit of the concentration for 1.36 μm polystyrene beads can be down to 1 particle/mL. The detection limit of the Escherichia coli (E. coli bacteria was 20 CFU/mL. The fiber tip sensor takes advantages of ultrasmall volume, label-free and simple detection system.

  18. Detection of neutrinos, antineutrinos, and neutrino-like particles

    Energy Technology Data Exchange (ETDEWEB)

    Fischbach, Ephraim

    2018-04-24

    An apparatus for detecting the presence of a nuclear reactor by the detection of antineutrinos from the reactor can include a radioactive sample having a measurable nuclear activity level and a decay rate capable of changing in response to the presence of antineutrinos, and a detector associated with the radioactive sample. The detector is responsive to at least one of a particle or radiation formed by decay of the radioactive sample. A processor associated with the detector can correlate rate of decay of the radioactive sample to a flux of the antineutrinos to detect the reactor.

  19. Mixing state of particles with secondary species by single particle aerosol mass spectrometer in an atmospheric pollution event

    Science.gov (United States)

    Xu, Lingling; Chen, Jinsheng

    2016-04-01

    Single particle aerosol mass spectrometer (SPAMS) was used to characterize size distribution, chemical composition, and mixing state of particles in an atmospheric pollution event during 20 Oct. - 5 Nov., 2015 in Xiamen, Southeast China. A total of 533,012 particle mass spectra were obtained and clustered into six groups, comprising of industry metal (4.5%), dust particles (2.6%), carbonaceous species (70.7%), K-Rich particles (20.7%), seasalt (0.6%) and other particles (0.9%). Carbonaceous species were further divided into EC (70.6%), OC (28.5%), and mixed ECOC (0.9%). There were 61.7%, 58.3%, 4.0%, and 14.6% of particles internally mixed with sulfate, nitrate, ammonium and C2H3O, respectively, indicating that these particles had undergone significant aging processing. Sulfate was preferentially mixed with carbonaceous particles, while nitrate tended to mix with metal-containing and dust particles. Compared to clear days, the fractions of EC-, metal- and dust particles remarkably increased, while the fraction of OC-containing particles decreased in pollution days. The mixing state of particles, excepted for OC-containing particles with secondary species was much stronger in pollution days than that in clear days, which revealed the significant influence of secondary particles in atmospheric pollution. The different activity of OC-containing particles might be related to their much smaller aerodynamic diameter. These results could improve our understanding of aerosol characteristics and could be helpful to further investigate the atmospheric process of particles.

  20. Detection of glass particles on bone lesions using SEM-EDS.

    Science.gov (United States)

    Montoriol, Romain; Guilbeau-Frugier, Céline; Chantalat, Elodie; Roumiguié, Mathieu; Delisle, Marie-Bernadette; Payré, Bruno; Telmon, Norbert; Savall, Frédéric

    2017-09-01

    The problem of identifying the wounding agent in forensic cases is recurrent. Moreover, when several tools are involved, distinguishing the origin of lesions can be difficult. Scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDS) equipment is increasingly available to the scientific and medical community, and some studies have reported its use in forensic anthropology. However, at our knowledge, no study has reported the use of SEM-EDS in forensic cases involving glass tools, whether in case reports or experiments. We performed an experimental study on human rib fragments, on which we manually created wounds using fragments of window and mirror glass. SEM-EDS was executed on samples without any further preparation on low vacuum mode, then on the same samples after defleshing them completely by boiling them. Window and mirror glass particles were detected on experimental wounds. Both had silica in their spectra, and the opaque side of the mirror contained titanium, allowing for their identification. Boiling and defleshing the bone samples involved a loss of information in terms of the number of wounds detected as positive for glass particles and in the number of glass particles detected, for both window and mirror glass. We suggest the analysis of wounds with suspected glass particles using low vacuum mode and with no defleshment by boiling.

  1. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Madsen, Jacob; Reichelt, Christian Günther

    2015-01-01

    even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes...... place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our...... results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schro...

  2. Interplay of single particle and collective response in molecular dynamics simulation of dusty plasma system

    Science.gov (United States)

    Maity, Srimanta; Das, Amita; Kumar, Sandeep; Tiwari, Sanat Kumar

    2018-04-01

    The collective response of the plasma medium is well known and has been explored extensively in the context of dusty plasma medium. On the other hand, the individual particle response associated with the collisional character giving rise to the dissipative phenomena has not been explored adequately. In this paper, two-dimensional molecular dynamics simulation of dust particles interacting via Yukawa potential has been considered. It has been shown that disturbances induced in a dust crystal elicit both collective and single particle responses. Generation of a few particles moving at speeds considerably higher than acoustic and/or shock speed (excited by the external disturbance) is observed. This is an indication of a single particle response. Furthermore, as these individual energetic particles propagate, the dust crystal is observed to crack along their path. Initially when the energy is high, these particles generate secondary energetic particles by the collisional scattering process. However, ultimately as these particles slow down they excite a collective response in the dust medium at secondary locations in a region which is undisturbed by the primary external disturbance. The condition when the cracking of the crystal stops and collective excitations get initiated has been identified quantitatively. The trailing collective primary disturbances would thus often encounter a disturbed medium with secondary and tertiary collective perturbations, thereby suffering significant modification in its propagation. It is thus clear that there is an interesting interplay (other than mere dissipation) between the single particle and collective response which governs the dynamics of any disturbance introduced in the medium.

  3. Quantum chaos in nuclear single-particle motion and damping of giant resonances

    International Nuclear Information System (INIS)

    Pal, Santanu; Mukhopadhyay, Tapan

    1995-01-01

    The spectral statistics of single particle motion in deformed cavities with axial symmetry are presented. The single particle motion in the cavities considered are non-integrable and the systematics of the fluctuation measures of the spectra reveal a transition from regular to chaotic regime in the corresponding classical systems. Quantitative estimate of the degree of chaos enables us to introduce a correction factor to the one-body wall formula for the damping widths of isoscalar giant resonances. The damping widths calculated with this correction factor give much better agreement with experimental values than earlier calculations of one-body damping widths. (author). 21 refs., 5 figs

  4. Characterization of a detector chain using a FPGA-based time-to-digital converter to reconstruct the three-dimensional coordinates of single particles at high flux

    Science.gov (United States)

    Nogrette, F.; Heurteau, D.; Chang, R.; Bouton, Q.; Westbrook, C. I.; Sellem, R.; Clément, D.

    2015-11-01

    We report on the development of a novel FPGA-based time-to-digital converter and its implementation in a detection chain that records the coordinates of single particles along three dimensions. The detector is composed of micro-channel plates mounted on top of a cross delay line and connected to fast electronics. We demonstrate continuous recording of the timing signals from the cross delay line at rates up to 4.1 × 106 s-1 and three-dimensional reconstruction of the coordinates up to 3.2 × 106 particles per second. From the imaging of a calibrated structure we measure the in-plane resolution of the detector to be 140(20) μm at a flux of 3 × 105 particles per second. In addition, we analyze a method to estimate the resolution without placing any structure under vacuum, a significant practical improvement. While we use UV photons here, the results of this work apply to the detection of other kinds of particles.

  5. White-light Detection for Nanoparticle Sizing with the TSI Ultrafine Condensation Particle Counter

    International Nuclear Information System (INIS)

    Dick, William D.; McMurry, Peter H.; Weber, Rodney J.; Quant, Frederick R.

    2000-01-01

    Several of the most common methods for measuring nanoparticle size distributions employ the ultrafine condensation particle counter (UCPC) for detection purposes. Among these methods, the pulse height analysis (PHA) technique, in which the optical response of the UCPC detector is related to initial particle diameter in the 3-10 nm range, prevails in applications where fast sampling is required or for which concentrations of nanoparticles are frequently very low. With the PHA technique, white light is required for particle illumination in order to obtain a monotonic relationship between initial particle diameter and optical response (pulse height). However, the popular, commercially available TSI Model 3025A UCPC employs a laser for particle detection. Here, we report on a novel white-light detection system developed for the 3025A UCPC that involves minimal alteration to the instrument and preserves normal counting operation. Performance is illustrated with pulse height spectra produced by differential mobility analyzer (DMA) - generated calibration aerosols in the 3-50 nm range

  6. Automated detection and analysis of particle beams in laser-plasma accelerator simulations

    International Nuclear Information System (INIS)

    Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat; Ruebel, O.; Weber, G.; Hamann, B.

    2010-01-01

    scientific data mining is increasingly considered. In plasma simulations, Bagherjeiran et al. presented a comprehensive report on applying graph-based techniques for orbit classification. They used the KAM classifier to label points and components in single and multiple orbits. Love et al. conducted an image space analysis of coherent structures in plasma simulations. They used a number of segmentation and region-growing techniques to isolate regions of interest in orbit plots. Both approaches analyzed particle accelerator data, targeting the system dynamics in terms of particle orbits. However, they did not address particle dynamics as a function of time or inspected the behavior of bunches of particles. Ruebel et al. addressed the visual analysis of massive laser wakefield acceleration (LWFA) simulation data using interactive procedures to query the data. Sophisticated visualization tools were provided to inspect the data manually. Ruebel et al. have integrated these tools to the visualization and analysis system VisIt, in addition to utilizing efficient data management based on HDF5, H5Part, and the index/query tool FastBit. In Ruebel et al. proposed automatic beam path analysis using a suite of methods to classify particles in simulation data and to analyze their temporal evolution. To enable researchers to accurately define particle beams, the method computes a set of measures based on the path of particles relative to the distance of the particles to a beam. To achieve good performance, this framework uses an analysis pipeline designed to quickly reduce the amount of data that needs to be considered in the actual path distance computation. As part of this process, region-growing methods are utilized to detect particle bunches at single time steps. Efficient data reduction is essential to enable automated analysis of large data sets as described in the next section, where data reduction methods are steered to the particular requirements of our clustering analysis

  7. Electrochemical detection of commercial silver nanoparticles: identification, sizing and detection in environmental media

    International Nuclear Information System (INIS)

    Stuart, E J E; Tschulik, K; Compton, R G; Omanović, D; Cullen, J T; Jurkschat, K; Crossley, A

    2013-01-01

    The electrochemistry of silver nanoparticles contained in a consumer product has been studied. The redox properties of silver particles in a commercially available disinfectant cleaning spray were investigated via cyclic voltammetry before particle-impact voltammetry was used to detect single particles in both a typical aqueous electrolyte and authentic seawater media. We show that particle-impact voltammetry is a promising method for the detection of nanoparticles that have leached into the environment from consumer products, which is an important development for the determination of risks associated with the incorporation of nanotechnology into everyday products. (paper)

  8. Detection and characterization of silver nanoparticles in chicken meat by asymmetric flow field flow fractionation with detection by conventional or single particle ICP-MS

    DEFF Research Database (Denmark)

    Löschner, Katrin; Navratilova, Jana; Købler, Carsten

    2013-01-01

    of the AgNPs took place during the sample preparation stage. The digestate was injected into the asymmetric flow field flow fractionation (AF(4)) -ICP-MS system, which enabled fractionation of nanoparticles from the remaining meat matrix, and resulted in one large peak in the fractograms as well as two...... smaller peaks eluting close to the void volume. The recovery of silver contained in the large AgNP peak was around 80 %. Size determination of AgNPs in the meat matrix, based on external size calibration of the AF(4) channel, was hampered by non-ideal (early elution) behavior of the AgNPs. Single particle...

  9. Authenticated multi-user quantum key distribution with single particles

    Science.gov (United States)

    Lin, Song; Wang, Hui; Guo, Gong-De; Ye, Guo-Hua; Du, Hong-Zhen; Liu, Xiao-Fen

    2016-03-01

    Quantum key distribution (QKD) has been growing rapidly in recent years and becomes one of the hottest issues in quantum information science. During the implementation of QKD on a network, identity authentication has been one main problem. In this paper, an efficient authenticated multi-user quantum key distribution (MQKD) protocol with single particles is proposed. In this protocol, any two users on a quantum network can perform mutual authentication and share a secure session key with the assistance of a semi-honest center. Meanwhile, the particles, which are used as quantum information carriers, are not required to be stored, therefore the proposed protocol is feasible with current technology. Finally, security analysis shows that this protocol is secure in theory.

  10. Summary report of the group on single-particle nonlinear dynamics

    International Nuclear Information System (INIS)

    Axinescu, S.; Bartolini, R.; Bazzani, A.

    1996-10-01

    This report summarizes the research on single-particle nonlinear beam dynamics. It discusses the following topics: analytical and semi-analytical tools; early prediction of the dynamic aperture; how the results are commonly presented; Is the mechanism of the dynamic aperture understand; ripple effects; and beam-beam effects

  11. Single particle level density in a finite depth potential well

    International Nuclear Information System (INIS)

    Shlomo, S.; Kolomietz, V.M.; Dejbakhsh, H.

    1997-01-01

    We consider the single particle level density g(ε) of a realistic finite depth potential well, concentrating on the continuum (ε>0) region. We carry out quantum-mechanical calculations of the partial level density g l (ε), associated with a well-defined orbital angular momentum l≤40, using the phase-shift derivative method and the Greens-function method and compare the results with those obtained using the Thomas-Fermi approximation. We also numerically calculate g(ε) as a l sum of g l (ε) up to a certain value of scr(l) max ≤40 and determine the corresponding smooth level densities using the Strutinsky smoothing procedure. We demonstrate, in accordance with Levinson close-quote s theorem, that the partial contribution g l (ε) to the single particle level density from continuum states has positive and negative values. However, g(ε) is nonnegative. We also point out that this is not the case for an energy-dependent potential well. copyright 1997 The American Physical Society

  12. Note: Electrostatic detection of stainless steel dust particles for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Landy, P. [Mechanical and Aerospace Engineering Department, Cornell University, Ithaca, New York 14853 (United States); Skinner, C. H.; Schneider, H. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-03-15

    Dust accumulation inside next-step fusion devices poses a significant safety concern and dust diagnostics will be needed to assure safe operations. An electrostatic dust detection device has been successfully demonstrated in the National Spherical Torus Experiment, Tore Supra, and the Large Helical Device, and the detector's response to carbon particles was previously characterized in laboratory experiments. This paper presents laboratory results showing that detection of stainless steel particles at levels as low as several μg/cm{sup 2} is also possible.

  13. Neuronal synchrony detection on single-electron neural networks

    International Nuclear Information System (INIS)

    Oya, Takahide; Asai, Tetsuya; Kagaya, Ryo; Hirose, Tetsuya; Amemiya, Yoshihito

    2006-01-01

    Synchrony detection between burst and non-burst spikes is known to be one functional example of depressing synapses. Kanazawa et al. demonstrated synchrony detection with MOS depressing synapse circuits. They found that the performance of a network with depressing synapses that discriminates between burst and random input spikes increases non-monotonically as the static device mismatch is increased. We designed a single-electron depressing synapse and constructed the same network as in Kanazawa's study to develop noise-tolerant single-electron circuits. We examined the temperature characteristics and explored possible architecture that enables single-electron circuits to operate at T > 0 K

  14. Detecting particle dark matter signatures by cross-correlating γ-ray anisotropies with weak lensing

    Science.gov (United States)

    Camera, S.; Fornasa, M.; Fornengo, N.; Regis, M.

    2016-05-01

    The underlying nature of dark matter still represents one of the fundamental questions in contemporary cosmology. Although observations well agree with its description in terms of a new fundamental particle, neither direct nor indirect signatures of its particle nature have been detected so far, despite a strong experimental effort. Similarly, particle accelerators have hitherto failed at producing dark matter particles in collider physics experiments. Here, we illustrate how the cross-correlation between anisotropies in the diffuse γ-ray background and weak gravitational lensing effects represents a novel promising way in the quest of detecting particle dark matter signatures.

  15. Aperture and counting rate of rectangular telescopes for single and multiple parallel particles. [Spark chamber telescopes

    Energy Technology Data Exchange (ETDEWEB)

    D' Ettorre Piazzoli, B; Mannocchi, G [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Melone, S [Istituto di Fisica dell' Universita, Ancona, Italy; Picchi, P; Visentin, R [Comitato Nazionale per l' Energia Nucleare, Frascati (Italy). Laboratori Nazionali di Frascati

    1976-06-01

    Expressions for the counting rate of rectangular telescopes in the case of single as well as multiple particles are given. The aperture for single particles is obtained in the form of a double integral and analytical solutions are given for some cases. The intensity for different multiplicities of parallel particles is related to the geometry of the detectors and to the features of the radiation. This allows an absolute comparison between the data recorded by different devices.

  16. Generating high-quality single droplets for optical particle characterization with an easy setup

    Science.gov (United States)

    Xu, Jie; Ge, Baozhen; Meng, Rui

    2018-06-01

    The high-performance and micro-sized single droplet is significant for optical particle characterization. We develop a single-droplet generator (SDG) based on a piezoelectric inkjet technique with advantages of low cost and easy setup. By optimizing the pulse parameters, we achieve various size single droplets. Further investigations reveal that SDG generates single droplets of high quality, demonstrating good sphericity, monodispersity and a stable length of several millimeters.

  17. Deflection of high energy channeled charged particles by elastically bent silicon single crystals

    International Nuclear Information System (INIS)

    Gibson, W.M.; Kim, I.J.; Pisharodoy, M.; Salman, S.M.; Sun, C.R.; Wang, G.H.; Wijayawardana, R.; Forster, J.S.; Mitchell, I.V.; Baker, S.I.; Carrigan, R.A. Jr.; Toohig, T.E.; Avdeichikov, V.V.; Ellison, J.A.; Siffert, P.

    1984-01-01

    An experiment has been carried out to observe the deflection of charged particles by planar channeling in bent single crystals of silicon for protons with energy up to 180 GeV. Anomolous loss of particles from the center point of a three point bending apparatus was observed at high incident particle energy. This effect has been exploited to fashion a 'dechanneling spectrometer' to study dechanneling effects due to centripital displacement of channeled particle trajectories in a bent crystal. The bending losses generally conform to the predictions of calculations based on a classical model. (orig.)

  18. Statistical and direct decay of high-lying single-particle excitations

    International Nuclear Information System (INIS)

    Gales, S.

    1993-01-01

    Transfer reactions induced by hadronic probes at intermediate energies have revealed a rich spectrum of high-lying excitations embedded in the nuclear continuum. The investigation of their decay properties is believed to be a severe test of their microscopic structure as predicted by microscopic nuclear models. In addition the degree of damping of these simple modes in the nuclear continuum can be obtained by means of the measured particle (n,p) decay branching ratios. The neutron and proton decay studies of high-lying single-particle states in heavy nuclei are presented. (author). 13 refs., 9 figs

  19. Pyrolysis and Gasification Kinetics of Large Biomass Particles

    Energy Technology Data Exchange (ETDEWEB)

    Svenson, Jenny; Hagstroem, Magnus; Andersson, Patrik U.; Loenn, Benny; Pettersson, Jan B.C. [Goteborg Univ. (Sweden). Dep. of Chemistry, Atmospheric Science; Davidsson, Kent O. [Chalmers Univ. of Technology, Goeteborg (Sweden). Energy Conversion

    2004-05-01

    The aim of the project is to provide experimental data on single biomass particle pyrolysis that have an applied as well as a fundamental bearing. Transport phenomena and kinetics on the single particle level are characterized, including heat and mass transport processes. New experimental techniques and methods are applied and developed within the project. A single-particle reactor has been developed for the investigations, and several detection techniques including fast thermogravimetric analysis, molecular beam mass spectrometry, laser spectroscopy, video recording and pyrometry are applied. The experimental data are used to develop robust models for pyrolysis and gasification, which are essential components in the design of gasification and combustion reactors.

  20. A detection method of negative pionlike particles from a H2 gas discharge plasma

    International Nuclear Information System (INIS)

    Uramoto, Joshin.

    1996-02-01

    The negative pionlike particles π - penetrate a metal (or insulator) plate if positive ions produced secondarily by H - ions, diffuse to the back of the plate. Thus, the π - particles are not detected by a usual beam collector of mass analyzer using a metal plate. In order to detect the π - particles, we must interrupt the diffusion of the positive ions to the back of the beam collector while the π - particles are confined inside the beam collector and changed into a multiplied electron current. (author)

  1. Photoionisation detection of single 87Rb-atoms using channel electron multipliers

    International Nuclear Information System (INIS)

    Henkel, Florian Alexander

    2011-01-01

    Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p ion =0.991 within an ionisation time of t ion =386 ns is achieved for a single 87 Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of η atom =0.991 within a detection time of t det =415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral 87 Rb-atoms via photoionisation detection with an estimated detection efficiency η=0.982 and a detection time of t tot = 802 ns. Although initially developed for single 87 Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any atomic or molecular species. As efficient

  2. The nature of (sub-)micrometre cometary dust particles detected with MIDAS

    Science.gov (United States)

    Mannel, T.; Bentley, M. S.; Torkar, K.; Jeszenszky, H.; Romstedt, J.; Schmied, R.

    2015-10-01

    The MIDAS Atomic Force Microscope (AFM) onboard Rosetta collects dust particles and produces three-dimensional images with nano- to micrometre resolution. To date, several tens of particles have been detected, allowing determination of their properties at the smallest scale. The key features will be presented, including the particle size, their fragile character, and their morphology. These findings will be compared with the results of other Rosetta dust experiments.

  3. Distributed Sensor Particles for Remote Fluorescence Detection of Trace Analytes: UXO/CW; TOPICAL

    International Nuclear Information System (INIS)

    SINGH, ANUP K.; GUPTA, ALOK; MULCHANDANI, ASHOK; CHEN, WILFRED; BHATIA, RIMPLE B.; SCHOENIGER, JOSEPH S.; ASHLEY, CAROL S.; BRINKER, C. JEFFREY; HANCE, BRADLEY G.; SCHMITT, RANDAL L.; JOHNSON, MARK S.; HARGIS JR. PHILIP J.; SIMONSON, ROBERT J.

    2001-01-01

    This report summarizes the development of sensor particles for remote detection of trace chemical analytes over broad areas, e.g residual trinitrotoluene from buried landmines or other unexploded ordnance (UXO). We also describe the potential of the sensor particle approach for the detection of chemical warfare (CW) agents. The primary goal of this work has been the development of sensor particles that incorporate sample preconcentration, analyte molecular recognition, chemical signal amplification, and fluorescence signal transduction within a ''grain of sand''. Two approaches for particle-based chemical-to-fluorescence signal transduction are described: (1) enzyme-amplified immunoassays using biocompatible inorganic encapsulants, and (2) oxidative quenching of a unique fluorescent polymer by TNT

  4. Single-nanoparticle detection with slot-mode photonic crystal cavities

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cheng; Kita, Shota; Lončar, Marko, E-mail: loncar@seas.harvard.edu [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Quan, Qimin [Rowland Institute at Harvard University, Cambridge, Massachusetts 02142 (United States); Li, Yihang [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Department of Electronic Engineering, Tsinghua University, Beijing 100084 (China)

    2015-06-29

    Optical cavities that are capable for detecting single nanoparticles could lead to great progress in early stage disease diagnostics and the study of biological interactions on the single-molecule level. In particular, photonic crystal (PhC) cavities are excellent platforms for label-free single-nanoparticle detection, owing to their high quality (Q) factors and wavelength-scale modal volumes. Here, we demonstrate the design and fabrication of a high-Q (>10{sup 4}) slot-mode PhC nanobeam cavity, which is able to strongly confine light in the slotted regions. The enhanced light-matter interaction results in an order of magnitude improvement in both refractive index sensitivity (439 nm/RIU) and single-nanoparticle sensitivity compared with conventional dielectric-mode PhC cavities. Detection of single polystyrene nanoparticles with radii of 20 nm and 30 nm is demonstrated in aqueous environments (D{sub 2}O), without additional laser and temperature stabilization techniques.

  5. Evolution of Single-Particle Energies for N=9 Nuclei at Large N/Z

    Directory of Open Access Journals (Sweden)

    Wuosmaa A. H.

    2014-03-01

    Full Text Available We have studied the nucleus 14B using the 13B(d,p14B and 15C(d,3He14B reactions. The two reactions provide complementary information about the negative-parity 1s1/2 and 0d5/2 neutron single-particle states in 14B. The data from the (d,p reaction give neutron-spectroscopic strengths for these levels, and the (d,3He results confirm the existence of a broad 2- excited state suggested in the literature. Together these results provide estimates of the sd-shell neutron effective single-particle energies in 14B.

  6. Plasmon excitation in single wall carbon nanotubes by penetrating charged particles

    International Nuclear Information System (INIS)

    Segui, Silvina; Gervasoni, Juana L; Arista, Néstor R; Mowbray, Duncan J; Mišković, Zoran L

    2012-01-01

    In this work we study the excitation of plasmons due to the incidence of a charged particle passing through a single wall carbon nanotube. We use a quantized hydrodynamic, in which the σ and π electrons characteristic of these carbonaceous structures are depicted as two interacting 2-dimensional fluids, to calculate the average number of plasmons excited. We analyze the contribution of the different plasmon modes in a variety of configurations, and study the energy lost by the incident particle.

  7. Quantum private comparison with d-level single-particle states

    International Nuclear Information System (INIS)

    Yu, Chao-Hua; Guo, Gong-De; Lin, Song

    2013-01-01

    In this paper, a quantum private comparison protocol with d-level single-particle states is proposed. In the protocol, a semi-honest third party is introduced to help two participants compare the size relationship of their secrets without revealing them to any other people. It is shown that the protocol is secure in theory. Moreover, the security of the protocol in real circumstance is also discussed. (paper)

  8. Radiative capture of nucleons at astrophysical energies with single-particle states

    International Nuclear Information System (INIS)

    Huang, J.T.; Bertulani, C.A.; Guimaraes, V.

    2010-01-01

    Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.

  9. New generation of monolithic active pixel sensors for charged particle detection

    International Nuclear Information System (INIS)

    Deptuch, G.

    2002-09-01

    Vertex detectors are of great importance in particle physics experiments, as the knowledge of the event flavour is becoming an issue for the physics programme at Future Linear Colliders. Monolithic Active Pixel Sensors (MAPS) based on a novel detector structure have been proposed. Their fabrication is compatible with a standard CMOS process. The sensor is inseparable from the readout electronics, since both of them are integrated on the same, low-resistivity silicon wafer. The basic pixel configuration comprises only three MOS transistors and a diode collecting the charge through thermal diffusion. The charge is generated in the thin non-depleted epitaxial layer underneath the readout electronics. This approach provides, at low cost, a high resolution and thin device with the whole area sensitive to radiation. Device simulations using the ISE-TCAD package have been carried out to study the charge collection mechanism. In order to demonstrate the viability of the technique, four prototype chips have been fabricated using different submicrometer CMOS processes. The pixel gain has been calibrated using a 55 Fe source and the Poisson sequence method. The prototypes have been exposed to high-energy particle beams at CERN. The tests proved excellent detection performances expressed in a single-track spatial resolution of 1.5 μm and detection efficiency close to 100%, resulting from a SNR ratio of more than 30. Irradiation tests showed immunity of MAPS to a level of a few times 10 12 n/cm 2 and a few hundred kRad of ionising radiation. The ideas for future work, including on-pixel signal amplification, double sampling operation and current mode pixel design are present as well. (author)

  10. Single-particle properties of N = 12 to N = 20 silicon isotopes within the dispersive optical model

    Science.gov (United States)

    Bespalova, O. V.; Ermakova, T. A.; Klimochkina, A. A.; Spasskaya, T. I.

    2017-09-01

    Experimental neutron and proton single-particle energies in N = 12 to N = 20 silicon isotopes and data on neutron and proton scattering by nuclei of the isotope 28Si are analyzed on the basis of the dispersive optical model. Good agreement with available experimental data was attained. The occupation probabilities calculated for the single-particle states in question suggest a parallel-type filling of the 1 d and 2 s 1/2 neutron states in the isotopes 26,28,30,32,34Si. The single-particle spectra being considered are indicative of the closure of the Z = 14 proton subshell in the isotopes 30,32,34Si and the N = 20 neutron shell.

  11. Study of a charge-coupled device for high-energy-particle detection

    International Nuclear Information System (INIS)

    Bhuiya, A.H.

    1983-05-01

    This presentation is based on measurements made to evaluate the application of charge-coupled devices as detectors of high-energy particles. The experiment was performed with a Fairchild Linear 256-Cell CCD111 array (size 8μm x 17 μm/cell), utilizing a light source instead of a particle beam. It was observed that the minimum detectable signal was limited to approx. 488 electrons at -50 0 C, where the readout and exposure times were about 260 ms and 400 ms respectively. The transfer inefficiency of the CCD111 was determined to be approx. 10 -4 . It has been concluded that at a lower temperature (approx. -100 0 C) or with faster readout (approx. 10 ms), the CCD111 would be able to detect the total deposited energy of minimum-ionizing charged particles

  12. Lens-free imaging of magnetic particles in DNA assays.

    Science.gov (United States)

    Colle, Frederik; Vercruysse, Dries; Peeters, Sara; Liu, Chengxun; Stakenborg, Tim; Lagae, Liesbet; Del-Favero, Jurgen

    2013-11-07

    We present a novel opto-magnetic system for the fast and sensitive detection of nucleic acids. The system is based on a lens-free imaging approach resulting in a compact and cheap optical readout of surface hybridized DNA fragments. In our system magnetic particles are attracted towards the detection surface thereby completing the labeling step in less than 1 min. An optimized surface functionalization combined with magnetic manipulation was used to remove all nonspecifically bound magnetic particles from the detection surface. A lens-free image of the specifically bound magnetic particles on the detection surface was recorded by a CMOS imager. This recorded interference pattern was reconstructed in software, to represent the particle image at the focal distance, using little computational power. As a result we were able to detect DNA concentrations down to 10 pM with single particle sensitivity. The possibility of integrated sample preparation by manipulation of magnetic particles, combined with the cheap and highly compact lens-free detection makes our system an ideal candidate for point-of-care diagnostic applications.

  13. Characterization of biomass combustion at high temperatures based on an upgraded single particle model

    International Nuclear Information System (INIS)

    Li, Jun; Paul, Manosh C.; Younger, Paul L.; Watson, Ian; Hossain, Mamdud; Welch, Stephen

    2015-01-01

    Highlights: • High temperature rapid biomass combustion is studied based on single particle model. • Particle size changes in devolatilization and char oxidation models are addressed. • Time scales of various thermal sub-processes are compared and discussed. • Potential solutions are suggested to achieve better biomass co-firing performances. - Abstract: Biomass co-firing is becoming a promising solution to reduce CO 2 emissions, due to its renewability and carbon neutrality. Biomass normally has high moisture and volatile contents, complicating its combustion behavior, which is significantly different from that of coal. A computational fluid dynamics (CFD) combustion model of a single biomass particle is employed to study high-temperature rapid biomass combustion. The two-competing-rate model and kinetics/diffusion model are used to model biomass devolatilization reaction and char burnout process, respectively, in which the apparent kinetics used for those two models were from high temperatures and high heating rates tests. The particle size changes during the devolatilization and char burnout are also considered. The mass loss properties and temperature profile during the biomass devolatilization and combustion processes are predicted; and the timescales of particle heating up, drying, devolatilization, and char burnout are compared and discussed. Finally, the results shed light on the effects of particle size on the combustion behavior of biomass particle

  14. Particle imaging velocimetry experiments and lattice-Boltzmann simulations on a single sphere settling under gravity

    NARCIS (Netherlands)

    Ten Cate, A.; Nieuwstad, C.H.; Derksen, J.J.; Van den Akker, H.E.A.

    2002-01-01

    A comparison is made between experiments and simulations on a single sphere settling in silicon oil in a box. Cross-correlation particle imaging velocimetry measurements were carried out at particle Reynolds numbers ranging from 1.5 to 31.9. The particle Stokes number varied from 0.2 to 4 and at

  15. Direct uranium isotope ratio analysis of single micrometer-sized glass particles

    OpenAIRE

    Kappel, Stefanie; Boulyga, Sergei F.; Prohaska, Thomas

    2012-01-01

    We present the application of nanosecond laser ablation (LA) coupled to a ‘Nu Plasma HR’ multi collector inductively coupled plasma mass spectrometer (MC-ICP-MS) for the direct analysis of U isotope ratios in single, 10–20 μm-sized, U-doped glass particles. Method development included studies with respect to (1) external correction of the measured U isotope ratios in glass particles, (2) the applied laser ablation carrier gas (i.e. Ar versus He) and (3) the accurate determination of lower abu...

  16. Single-Molecule Plasmon Sensing: Current Status and Future Prospects.

    Science.gov (United States)

    Taylor, Adam B; Zijlstra, Peter

    2017-08-25

    Single-molecule detection has long relied on fluorescent labeling with high quantum-yield fluorophores. Plasmon-enhanced detection circumvents the need for labeling by allowing direct optical detection of weakly emitting and completely nonfluorescent species. This review focuses on recent advances in single molecule detection using plasmonic metal nanostructures as a sensing platform, particularly using a single particle-single molecule approach. In the past decade two mechanisms for plasmon-enhanced single-molecule detection have been demonstrated: (1) by plasmonically enhancing the emission of weakly fluorescent biomolecules, or (2) by monitoring shifts of the plasmon resonance induced by single-molecule interactions. We begin with a motivation regarding the importance of single molecule detection, and advantages plasmonic detection offers. We describe both detection mechanisms and discuss challenges and potential solutions. We finalize by highlighting the exciting possibilities in analytical chemistry and medical diagnostics.

  17. An approach to calculating metal particle detection in lubrication oil based on a micro inductive sensor

    Science.gov (United States)

    Wu, Yu; Zhang, Hongpeng

    2017-12-01

    A new microfluidic chip is presented to enhance the sensitivity of a micro inductive sensor, and an approach to coil inductance change calculation is introduced for metal particle detection in lubrication oil. Electromagnetic knowledge is used to establish a mathematical model of an inductive sensor for metal particle detection, and the analytic expression of coil inductance change is obtained by a magnetic vector potential. Experimental verification is carried out. The results show that copper particles 50-52 µm in diameter have been detected; the relative errors between the theoretical and experimental values are 7.68% and 10.02% at particle diameters of 108-110 µm and 50-52 µm, respectively. The approach presented here can provide a theoretical basis for an inductive sensor in metal particle detection in oil and other areas of application.

  18. Real stabilization method for nuclear single-particle resonances

    International Nuclear Information System (INIS)

    Zhang Li; Zhou Shangui; Meng Jie; Zhao Enguang

    2008-01-01

    We develop the real stabilization method within the framework of the relativistic mean-field (RMF) model. With the self-consistent nuclear potentials from the RMF model, the real stabilization method is used to study single-particle resonant states in spherical nuclei. As examples, the energies, widths, and wave functions of low-lying neutron resonant states in 120 Sn are obtained. These results are compared with those from the scattering phase-shift method and the analytic continuation in the coupling constant approach and satisfactory agreements are found

  19. Single twistor description of massless, massive, AdS, and other interacting particles

    International Nuclear Information System (INIS)

    Bars, Itzhak; Picon, Moises

    2006-01-01

    The Penrose transform between twistors and the phase space of massless particles is generalized from the massless case to an assortment of other particle dynamical systems, including special examples of massless or massive particles, relativistic or nonrelativistic, interacting or noninteracting, in flat space or curved spaces. Our unified construction involves always the same twistor Z A with only four complex degrees of freedom and subject to the same helicity constraint. Only the twistor to phase space transform differs from one case to another. Hence, a unification of diverse particle dynamical systems is displayed by the fact that they all share the same twistor description. Our single twistor approach seems to be rather different and a strikingly economical construction of twistors compared to other past approaches that introduced multiple twistors to represent some similar but far more limited set of particle phase space systems

  20. Detection of fine magnetic particles coated on a thread using an HTS-SQUID

    International Nuclear Information System (INIS)

    Kawagishi, K.; Itozaki, H.; Kondo, T.; Komori, K.; Koetitz, R.

    2004-01-01

    Polymer-coated magnetic particles, which contain superparamagnetic ferrite nanoparticles, were attached to a nylon thread of 0.35 mm in diameter and were detected by an HTS-SQUID. The length of the sample attached into the thread was within 3 mm and its interval was 30 mm. The particles were magnetized by a coil applied dc field or by a magnet of 1.4 T. The thread ran 2 mm under the SQUID with 20-100 mm/s of the rate. Signals of magnetic beads were detected and the peak-to-peak amplitude of the signals was directly proportional to the applied field and the weight of the magnetic particles. Obtained peak-to-peak amplitude for 20 ng of magnetite particles was 350 pT at 0.25 mT of applied dc field with noise of 18 pT, and estimated detection limit was 10 ng. S/N ratio was improved by the remanence measurement using the magnet and 5.8 ng of detection limit was obtained. This measurement has been proved to be promising for the continuous analysis of ultra dilute DNA solution

  1. 3D dual-virtual-pinhole assisted single particle tracking microscopy

    International Nuclear Information System (INIS)

    Ma, Ye; Wang, Yifan; Zhou, Xin; Kuang, Cuifang; Liu, Xu

    2014-01-01

    We propose a novel approach for high-speed, three-dimensional single particle tracking (SPT), which we refer to as dual-virtual-pinhole assisted single particle tracking microscopy (DVPaSPTM). DVPaSPTM system can obtain axial information of the sample without optical or mechanical depth scanning, so as to offer numbers of advantages including faster imaging, improved efficiency and a great reduction of photobleaching and phototoxicity. In addition, by the use of the dual-virtual-pinhole, the effect that the quantum yield exerts to the fluorescent signal can be eliminated, which makes the measurement independent of the surroundings and increases the accuracy of the result. DVPaSPTM system measures the intensity within different virtual pinholes of which the radii are given by the host computer. Axial information of fluorophores can be measured by the axial response curve through the ratio of intensity signals. We demonstrated the feasibility of the proposed method by a series of experiments. Results showed that the standard deviation of the axial measurement was 19.2 nm over a 2.5 μm range with 30 ms temporal resolution. (papers)

  2. Single-photon light detection with transition-edge sensors

    International Nuclear Information System (INIS)

    Rajteri, M.; Taralli, E.; Portesi, C.; Monticone, E.

    2008-01-01

    Transition-Edge Sensors (TESs) are micro calorimeters that measure the energy of incident single-photons by the resistance increase of a superconducting film biased within the superconducting-to-normal transition. TES are able to detect single photons from x-ray to IR with an intrinsic energy resolution and photon-number discrimination capability. Metrological, astronomical and quantum communication applications are the fields where these properties can be particularly important. In this work, we report about characterization of different TESs based on Ti films. Single-photons have been detected from 200 nm to 800 nm working at T c ∼ 100 m K. Using a pulsed laser at 690 nm we have demonstrated the capability to resolve up to five photons.

  3. Magnetic particle detection in unshielded environment using orthogonal fluxgate gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    Elrefai, Ahmed L., E-mail: a.lotfyelrefai@gmail.com; Sasada, Ichiro [Applied Science for Electronics and Materials, Kyushu University, Kasuga (Japan)

    2015-05-07

    A new detection system for magnetic particles, which can operate in an unshielded environment, is developed using a fundamental mode orthogonal fluxgate gradiometer. The proposed detection system offers the advantages of cost, size, and weight reduction as compared to contamination detection systems using superconducting quantum interference device sensor. The detection system can be used to detect metallic contamination in foods or lithium ion battery production lines. The system has been investigated numerically to optimize various design parameters of the system. Experimental setup has been developed to evaluate some of the numerically predicted results. Steel balls were successfully detected down to the diameter of 50 μm.

  4. Relative and single particle diffusion estimates determined from smoke plume photographs

    International Nuclear Information System (INIS)

    Nappo, C.J. Jr.

    1978-01-01

    The formula given by Gifford (1959) for obtaining space-varying values of particle dispersion parameters from photographs of smoke puffs and plumes has been applied to high-altitude U-2 photographs of a long smoke plume generated at the Idaho National Engineering Laboratory near Idaho Falls. The turbulence time scale derived from the photographs was found to be in good agreement with estimates obtained within the framework of single- and two-particle diffusion theory applied to wind speed and direction data from a tower near the smoke source

  5. Single particle analysis based on Zernike phase contrast transmission electron microscopy.

    Science.gov (United States)

    Danev, Radostin; Nagayama, Kuniaki

    2008-02-01

    We present the first application of Zernike phase-contrast transmission electron microscopy to single-particle 3D reconstruction of a protein, using GroEL chaperonin as the test specimen. We evaluated the performance of the technique by comparing 3D models derived from Zernike phase contrast imaging, with models from conventional underfocus phase contrast imaging. The same resolution, about 12A, was achieved by both imaging methods. The reconstruction based on Zernike phase contrast data required about 30% fewer particles. The advantages and prospects of each technique are discussed.

  6. CVD diamond sensors for charged particle detection

    CERN Document Server

    Krammer, Manfred; Berdermann, E; Bergonzo, P; Bertuccio, G; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; D'Angelo, P; Dabrowski, W; Delpierre, P A; Dencuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Hallewell, G D; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Kass, R; Koeth, T W; Lo Giudice, A; Lü, R; MacLynne, L; Manfredotti, C; Meier, D; Mishina, M; Moroni, L; Oh, A; Pan, L S; Pernicka, Manfred; Peitz, A; Perera, L P; Pirollo, S; Procario, M; Riester, J L; Roe, S; Rousseau, L; Rudge, A; Russ, J; Sala, S; Sampietro, M; Schnetzer, S; Sciortino, S; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R; Trischuk, W; Tromson, D; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Wetstein, M; White, C; Zeuner, W; Zöller, M

    2001-01-01

    CVD diamond material was used to build position-sensitive detectors for single-charged particles to be employed in high-intensity physics experiments. To obtain position information, metal contacts shaped as strips or pixels are applied to the detector surface for one- or two- dimensional coordinate measurement. Strip detectors 2*4 cm/sup 2/ in size with a strip distance of 50 mu m were tested. Pixel detectors of various pixel sizes were bump bonded to electronics chips and investigated. A key issue for the use of these sensors in high intensity experiments is the radiation hardness. Several irradiation experiments were carried out with pions, protons and neutrons exceeding a fluence of 10/sup 15/ particles/cm/sup 2/. The paper presents an overview of the results obtained with strip and pixel detectors in high-energy test beams and summarises the irradiation studies. (8 refs).

  7. Single mimivirus particles intercepted and imaged with an X-ray laser

    Science.gov (United States)

    Seibert, M. Marvin; Ekeberg, Tomas; Maia, Filipe R. N. C.; Svenda, Martin; Andreasson, Jakob; Jönsson, Olof; Odić, Duško; Iwan, Bianca; Rocker, Andrea; Westphal, Daniel; Hantke, Max; DePonte, Daniel P.; Barty, Anton; Schulz, Joachim; Gumprecht, Lars; Coppola, Nicola; Aquila, Andrew; Liang, Mengning; White, Thomas A.; Martin, Andrew; Caleman, Carl; Stern, Stephan; Abergel, Chantal; Seltzer, Virginie; Claverie, Jean-Michel; Bostedt, Christoph; Bozek, John D.; Boutet, Sébastien; Miahnahri, A. Alan; Messerschmidt, Marc; Krzywinski, Jacek; Williams, Garth; Hodgson, Keith O.; Bogan, Michael J.; Hampton, Christina Y.; Sierra, Raymond G.; Starodub, Dmitri; Andersson, Inger; Bajt, Saša; Barthelmess, Miriam; Spence, John C. H.; Fromme, Petra; Weierstall, Uwe; Kirian, Richard; Hunter, Mark; Doak, R. Bruce; Marchesini, Stefano; Hau-Riege, Stefan P.; Frank, Matthias; Shoeman, Robert L.; Lomb, Lukas; Epp, Sascha W.; Hartmann, Robert; Rolles, Daniel; Rudenko, Artem; Schmidt, Carlo; Foucar, Lutz; Kimmel, Nils; Holl, Peter; Rudek, Benedikt; Erk, Benjamin; Hömke, André; Reich, Christian; Pietschner, Daniel; Weidenspointner, Georg; Strüder, Lothar; Hauser, Günter; Gorke, Hubert; Ullrich, Joachim; Schlichting, Ilme; Herrmann, Sven; Schaller, Gerhard; Schopper, Florian; Soltau, Heike; Kühnel, Kai-Uwe; Andritschke, Robert; Schröter, Claus-Dieter; Krasniqi, Faton; Bott, Mario; Schorb, Sebastian; Rupp, Daniela; Adolph, Marcus; Gorkhover, Tais; Hirsemann, Helmut; Potdevin, Guillaume; Graafsma, Heinz; Nilsson, Björn; Chapman, Henry N.; Hajdu, Janos

    2014-01-01

    X-ray lasers offer new capabilities in understanding the structure of biological systems, complex materials and matter under extreme conditions1–4. Very short and extremely bright, coherent X-ray pulses can be used to outrun key damage processes and obtain a single diffraction pattern from a large macromolecule, a virus or a cell before the sample explodes and turns into plasma1. The continuous diffraction pattern of non-crystalline objects permits oversampling and direct phase retrieval2. Here we show that high-quality diffraction data can be obtained with a single X-ray pulse from a non-crystalline biological sample, a single mimivirus particle, which was injected into the pulsed beam of a hard-X-ray free-electron laser, the Linac Coherent Light Source5. Calculations indicate that the energy deposited into the virus by the pulse heated the particle to over 100,000 K after the pulse had left the sample. The reconstructed exit wavefront (image) yielded 32-nm full-period resolution in a single exposure and showed no measurable damage. The reconstruction indicates inhomogeneous arrangement of dense material inside the virion. We expect that significantly higher resolutions will be achieved in such experiments with shorter and brighter photon pulses focused to a smaller area. The resolution in such experiments can be further extended for samples available in multiple identical copies. PMID:21293374

  8. Single-particle and collective excitations in Ni-63

    OpenAIRE

    Albers, M.; Zhu, S.; Janssens, R. V. F.; Gellanki, Jnaneswari; Ragnarsson, Ingemar; Alcorta, M.; Baugher, T.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Deacon, A. N.; Gade, A.; DiGiovine, B.; Hoffman, C. R.

    2013-01-01

    A study of excited states in Ni-63 up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg-26(Ca-48,2 alpha 3n gamma)Ni-63 reaction at beam energies between 275 and 320 MeV. Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith quantifying the deformation at high spin. The results have been compared with shell-model and cranked Nilsson-...

  9. Micromanipulation and pick-up system for X-Ray diffraction characterization of micrometer-sized single particles

    International Nuclear Information System (INIS)

    Takeichi, Y; Inami, N; Saito, K; Otori, H; Sagayama, R; Kumai, R; Ono, K; Ueno, T

    2014-01-01

    We describe a micromanipulation and pick-up system for preparing a micrometer-sized single particle for X-ray diffraction characterization. Combining a microgripper based on microelectromechanical systems, piezo-motor-driven linear stages, and a gamepad, the system provides precise and intuitive handling of the object. Single-crystal X-ray diffraction measurements of Sm-Fe-N permanent magnet were performed using this system. We also describe a method to distinguish crystallographically homogeneous particles found in powder-form samples.

  10. Detection of special nuclear materials with the associate particle technique

    International Nuclear Information System (INIS)

    Carasco, Cédric; Deyglun, Clément; Pérot, Bertrand; Eléon, Cyrille; Normand, Stéphane; Sannié, Guillaume; Boudergui, Karim; Corre, Gwenolé; Konzdrasovs, Vladimir; Pras, Philippe

    2013-01-01

    In the frame of the French trans-governmental R and D program against chemical, biological, radiological, nuclear and explosives (CBRN-E) threats, CEA is studying the detection of Special Nuclear Materials (SNM) by neutron interrogation with fast neutrons produced by an associated particle sealed tube neutron generator. The deuterium-tritium fusion reaction produces an alpha particle and a 14 MeV neutron almost back to back, allowing tagging neutron emission both in time and direction with an alpha particle position-sensitive sensor embedded in the generator. Fission prompt neutrons and gamma rays induced by tagged neutrons which are tagged by an alpha particle are detected in coincidence with plastic scintillators. This paper presents numerical simulations performed with the MCNP-PoliMi Monte Carlo computer code and with post processing software developed with the ROOT data analysis package. False coincidences due to neutron and photon scattering between adjacent detectors (cross talk) are filtered out to increase the selectivity between nuclear and benign materials. Accidental coincidences, which are not correlated to an alpha particle, are also taken into account in the numerical model, as well as counting statistics, and the time-energy resolution of the data acquisition system. Such realistic calculations show that relevant quantities of SNM (few kg) can be distinguished from cargo and shielding materials in 10 min acquisitions. First laboratory tests of the system under development in CEA laboratories are also presented.

  11. The single- and double-particle properties and the current reversal of coupled Brownian motors

    International Nuclear Information System (INIS)

    Li, Chen-Pu; Chen, Hong-Bin; Zheng, Zhi-Gang; Fan, Hong; Shen, Wen-Mei

    2017-01-01

    In this paper, we investigate the directed transport of coupled Brownian motors composed of two identical particles which is individually subject to a time-symmetric rocking force in spatially-symmetric periodic potentials. We find that both the coupling free length and the coupling strength can induce the reversed motion of the coupled Brownian motors, the essence of which is the coupled Brownian motors can exhibit completely different single- or double-particle properties under certain conditions. Namely, the current reversal is the result of the mutual conversion between the single- and double-particle properties of the coupled Brownian motors. Moreover, the directed current of coupled Brownian motors can be optimized and manipulated by adjusting the strength, the period, the phase difference of the rocking forces, and the noise intensity. (paper)

  12. Two quasi-particle excitations with particle-hole core polarization in even-even single closed shell nuclei

    International Nuclear Information System (INIS)

    Gillet, V.; Giraud, B.; Rho, M.

    1976-01-01

    The energy levels and transition properties of the even-even N=28, 50 isotones and Z=28, 50, 82 isotopes are calculated in the framework of the Tamm-Dancoff and Random Phase Approximation, with an effective central interaction in an extended space consisting of two quasi-particle configurations for the open shell and particle-hole configurations for the closed core. Using the results of the Inverse Gap Equation Method, practically all the necessary input data (single quasi-particle energies, force strength) are extracted from the odd-mass nuclei. The ratios of the force components are kept at fixed values for all studied nuclei and no effective charge is used. An overall excellent agreement is obtained for the energies of the vibrational states. On the other hand, while the transition properties of the 3 - states are always well reproduced, those of the 2 + and 4 + states are often too small by about one order of magnitude [fr

  13. Efficiencies of dynamic Monte Carlo algorithms for off-lattice particle systems with a single impurity

    KAUST Repository

    Novotny, M.A.; Watanabe, Hiroshi; Ito, Nobuyasu

    2010-01-01

    The efficiency of dynamic Monte Carlo algorithms for off-lattice systems composed of particles is studied for the case of a single impurity particle. The theoretical efficiencies of the rejection-free method and of the Monte Carlo with Absorbing

  14. Single particle transfer for quantitative analysis with total-reflection X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Esaka, Fumitaka; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo

    2006-01-01

    The technique of single particle transfer was applied to quantitative analysis with total-reflection X-ray fluorescence (TXRF) spectrometry. The technique was evaluated by performing quantitative analysis of individual Cu particles with diameters between 3.9 and 13.2 μm. The direct quantitative analysis of the Cu particle transferred onto a Si carrier gave a discrepancy between measured and calculated Cu amounts due to the absorption effects of incident and fluorescent X-rays within the particle. By the correction for the absorption effects, the Cu amounts in individual particles could be determined with the deviation within 10.5%. When the Cu particles were dissolved with HNO 3 solution prior to the TXRF analysis, the deviation was improved to be within 3.8%. In this case, no correction for the absorption effects was needed for quantification

  15. Preparation of rod-like β-Si3N4 single crystal particles

    International Nuclear Information System (INIS)

    Hirao, K.; Tsuge, A.; Brito, M.E.; Kanzaki, S.

    1994-01-01

    The use of β-Si 3 N 4 particles as a seed material has been demonstrated to be effective for development of a self-reinforcing microstructure in sintered silicon nitride ceramics. We have confirmed the seeding effect and arrived at a concept that seed particles should consist of rod-like single crystals free from defects and with a large diameter. The present work describes our attempts to produce such particles with a controlled morphology and in high amount. β-Si 3 N 4 particles with a diameter of 1μm and length of 5μm were obtained by heating a mixture of α-Si 3 N 4 , SiO 2 and Y 2 O 3 , followed by acid rinse treatments to remove residual glassy phase. (orig.)

  16. Single-particle properties of the Hubbard model in a novel three-pole approximation

    Science.gov (United States)

    Di Ciolo, Andrea; Avella, Adolfo

    2018-05-01

    We study the 2D Hubbard model using the Composite Operator Method within a novel three-pole approximation. Motivated by the long-standing experimental puzzle of the single-particle properties of the underdoped cuprates, we include in the operatorial basis, together with the usual Hubbard operators, a field describing the electronic transitions dressed by the nearest-neighbor spin fluctuations, which play a crucial role in the unconventional behavior of the Fermi surface and of the electronic dispersion. Then, we adopt this approximation to study the single-particle properties in the strong coupling regime and find an unexpected behavior of the van Hove singularity that can be seen as a precursor of a pseudogap regime.

  17. Photoionisation detection of single {sup 87}Rb-atoms using channel electron multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Henkel, Florian Alexander

    2011-09-02

    Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p{sub ion}=0.991 within an ionisation time of t{sub ion}=386 ns is achieved for a single {sup 87}Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of {eta}{sub atom}=0.991 within a detection time of t{sub det}=415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral {sup 87}Rb-atoms via photoionisation detection with an estimated detection efficiency {eta}=0.982 and a detection time of t{sub tot} = 802 ns. Although initially developed for single {sup 87}Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any

  18. Acquiring Structural Information on Virus Particles with Charge Detection Mass Spectrometry

    Science.gov (United States)

    Keifer, David Z.; Motwani, Tina; Teschke, Carolyn M.; Jarrold, Martin F.

    2016-06-01

    Charge detection mass spectrometry (CDMS) is a single-molecule technique particularly well-suited to measuring the mass and charge distributions of heterogeneous, MDa-sized ions. In this work, CDMS has been used to analyze the assembly products of two coat protein variants of bacteriophage P22. The assembly products show broad mass distributions extending from 5 to 15 MDa for A285Y and 5 to 25 MDa for A285T coat protein variants. Because the charge of large ions generated by electrospray ionization depends on their size, the charge can be used to distinguish hollow shells from more compact structures. A285T was found to form T = 4 and T = 7 procapsids, and A285Y makes a small number of T = 3 and T = 4 procapsids. Owing to the decreased stability of the A285Y and A285T particles, chemical cross-linking was required to stabilize them for electrospray CDMS. Graphical Abstract[Figure not available: see fulltext.

  19. Prospects of real-time single-particle biological aerosol analysis: A comparison between laser-induced breakdown spectroscopy and aerosol time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Beddows, D.C.S.; Telle, H.H.

    2005-01-01

    In this paper we discuss the prospects of real-time, in situ laser-induced breakdown spectroscopy applied for the identification and classification of bio-aerosols (including species of potential bio-hazard) within common urban aerosol mixtures. In particular, we address the issues associated with the picking out of bio-aerosols against common background aerosol particles, comparing laser-induced breakdown spectroscopy measurements with data from a mobile single-particle aerosol mass spectrometer (ATOFMS). The data from the latter provide statistical data over an extended period of time, highlighting the variation of the background composition. While single-particle bio-aerosols are detectable in principle, potential problems with small (∼ 1 μm size) bio-aerosols have been identified; constituents of the air mass other than background aerosols, e.g. gaseous CO 2 in conjunction with common background aerosols, may prevent unique recognition of the bio-particles. We discuss whether it is likely that laser-induced breakdown spectroscopy on its own can provide reliable, real-time identification of bio-aerosol in an urban environment, and it is suggested that more than one technique should be or would have to be used. A case for using a combination of laser-induced breakdown spectroscopy and Raman (and/or) laser-induced fluorescence spectroscopy is made

  20. Detection of single quantum dots in model organisms with sheet illumination microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Mike; Nozadze, Revaz; Gan, Qiang; Zelman-Femiak, Monika; Ermolayev, Vladimir [Molecular Microscopy Group, Rudolf Virchow Center, University of Wuerzburg, Versbacher Str. 9, D-97078 Wuerzburg (Germany); Wagner, Toni U. [Institute of Physiological Chemistry I, Biocenter, University of Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany); Harms, Gregory S., E-mail: gregory.harms@virchow.uni-wuerzburg.de [Molecular Microscopy Group, Rudolf Virchow Center, University of Wuerzburg, Versbacher Str. 9, D-97078 Wuerzburg (Germany)

    2009-12-18

    Single-molecule detection and tracking is important for observing biomolecule interactions in the microenvironment. Here we report selective plane illumination microscopy (SPIM) with single-molecule detection in living organisms, which enables fast imaging and single-molecule tracking and optical penetration beyond 300 {mu}m. We detected single nanocrystals in Drosophila larvae and zebrafish embryo. We also report our first tracking of single quantum dots during zebrafish development, which displays a transition from flow to confined motion prior to the blastula stage. The new SPIM setup represents a new technique, which enables fast single-molecule imaging and tracking in living systems.

  1. Detection of single quantum dots in model organisms with sheet illumination microscopy

    International Nuclear Information System (INIS)

    Friedrich, Mike; Nozadze, Revaz; Gan, Qiang; Zelman-Femiak, Monika; Ermolayev, Vladimir; Wagner, Toni U.; Harms, Gregory S.

    2009-01-01

    Single-molecule detection and tracking is important for observing biomolecule interactions in the microenvironment. Here we report selective plane illumination microscopy (SPIM) with single-molecule detection in living organisms, which enables fast imaging and single-molecule tracking and optical penetration beyond 300 μm. We detected single nanocrystals in Drosophila larvae and zebrafish embryo. We also report our first tracking of single quantum dots during zebrafish development, which displays a transition from flow to confined motion prior to the blastula stage. The new SPIM setup represents a new technique, which enables fast single-molecule imaging and tracking in living systems.

  2. Control of cancer growth using single input autonomous fuzzy Nano-particles

    Directory of Open Access Journals (Sweden)

    Fahimeh Razmi

    2015-04-01

    Full Text Available In this paper a single input fuzzy controller is applied on autonomous drug-encapsulated nanoparticles (ADENPs to restrict the cancer growth. The proposed ADENPs, swarmly release the drug in local cancerous tissue and effectively decreases the destruction of normal tissue. The amount of released drug is defined considering to feed backed values of tumor growth rate and the used drug. Some significant characteristics of Nano particles compared to Nano-robots is their ability to recognize the cancerous tissue from the normal one and their simple structure. Nano particles became an attractive topic in Nano science and many efforts have been done to manufacture these particles. Simulation results show that the proposed controlling method not only decreases the cancerous tissue effectively but also reduces the side effects of drug impressively.

  3. Single particle nonlocality, geometric phases and time-dependent boundary conditions

    Science.gov (United States)

    Matzkin, A.

    2018-03-01

    We investigate the issue of single particle nonlocality in a quantum system subjected to time-dependent boundary conditions. We discuss earlier claims according to which the quantum state of a particle remaining localized at the center of an infinite well with moving walls would be specifically modified by the change in boundary conditions due to the wall’s motion. We first prove that the evolution of an initially localized Gaussian state is not affected nonlocally by a linearly moving wall: as long as the quantum state has negligible amplitude near the wall, the boundary motion has no effect. This result is further extended to related confined time-dependent oscillators in which the boundary’s motion is known to give rise to geometric phases: for a Gaussian state remaining localized far from the boundaries, the effect of the geometric phases is washed out and the particle dynamics shows no traces of a nonlocal influence that would be induced by the moving boundaries.

  4. A single particle energies

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1993-01-01

    We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei

  5. Single-shot LIBS spectral quality for waste particles in open air

    NARCIS (Netherlands)

    Xia, H.; Bakker, M.C.M.

    2015-01-01

    This work investigates the ability of LIBS to produce quality spectra from small particles of concrete demolition waste using single-shot spectra collected in open air. The 2–8?mm materials are rounded river gravel, green glass shards, and plastic flakes. Considered are focal length, air, moisture,

  6. Suitability of magnetic single- and multi-core nanoparticles to detect protein binding with dynamic magnetic measurement techniques

    International Nuclear Information System (INIS)

    Remmer, Hilke; Dieckhoff, Jan; Schilling, Meinhard; Ludwig, Frank

    2015-01-01

    We investigated the binding of biotinylated proteins to various streptavidin functionalized magnetic nanoparticles with different dynamic magnetic measurement techniques to examine their potential for homogeneous bioassays. As particle systems, single-core nanoparticles with a nominal core diameter of 30 nm as well as multi-core nanoparticles with hydrodynamic sizes varying between nominally 60 nm and 100 nm were chosen. As experimental techniques, fluxgate magnetorelaxometry (MRX), complex ac susceptibility (ACS) and measurements of the phase lag between rotating field and sample magnetization are applied. MRX measurements are only suited for the detection of small analytes if the multivalency of functionalized nanoparticles and analytes causes cross-linking, thus forming larger aggregates. ACS measurements showed for all nanoparticle systems a shift of the imaginary part's maximum towards small frequencies. In rotating field measurements only the single-core nanoparticle systems with dominating Brownian mechanism exhibit an increase of the phase lag upon binding in the investigated frequency range. The coexistence of Brownian and Néel relaxation processes can cause a more complex phase lag change behavior, as demonstrated for multi-core nanoparticle systems. - Highlights: • Cealization of homogeneous magnetic bioassays using different magnetic techniques. • Comparison of single- and multi-core nanoparticle systems. • ac Susceptibility favorable for detection of small analytes. • Magnetorelaxometry favorable for detection of large analytes or cross-linking assays

  7. Study of single particle properties of neutron-rich Na isotopes on the "shore of the island of inversion" by means of neutron-transfer reactions

    CERN Multimedia

    Reiter, P; Blazhev, A A; Riisager, K; Bastin, B; Tengborn, E A; Kruecken, R; Voulot, D; Jeppesen, H B; Hadinia, B; Gernhaeuser, R A; Fynbo, H O U; Georgiev, G P; Habs, D; Fraile prieto, L M; Chapman, R; Nilsson, T; Diriken, J V J; Jenkins, D G; Kroell, T; Leske, J; Huyse, M L; Patronis, N

    We aim at the investigation of single particle properties of neutron-rich Na isotopes around the "shore of the island of inversion". As first experiment of this programme, we propose to study excited states in the isotope $^{29}$Na by a one-neutron transfer reaction with a $^{28}$Na beam at 3 MeV/u obtained from REX-ISOLDE impinging on a CD$_{2}$-target. The $\\gamma$-rays will be detected by the MINIBALL array and the particles by the T-REX array of segmented Si detectors. The main physics aims are to extract from the relative spectroscopic factors information on the configurations contributing to the wave functions of the populated states and, secondly, to identify and characterize negative parity states whose excitation energies reflect directly the N= 28 gap in this region. The results will be compared to recent shell model calculations involving new residual interactions. This will shed new light on the evolution of single particle structure and help to understand the underlying physics relevant for the f...

  8. Detection of Bioaerosols Using Single Particle Thermal Emission Spectroscopy (First-year Report)

    Science.gov (United States)

    2012-02-01

    radiance is focused into 190-mm Horiba spectrometer where the radiance is dispersed onto an ultrafast, time-gated, liquid nitrogen (LN2) cooled 32...techniques were examined, i.e., methods that rely on acoustic levitation , radiative pressure, and suspension of small particles using the photophoretic...field of view HeNe helium-neon LN2 liquid nitrogen MCT mercury cadmium telluride NA numeric aperture Nd:YAG neodymium-doped yttrium aluminum

  9. Definition of a magnetic susceptibility of conglomerates with magnetite particles. Particularities of defining single particle susceptibility

    Science.gov (United States)

    Sandulyak, A. A.; Sandulyak, A. V.; Ershova, V.; Pamme, N.; Ngmasom, B.; Iles, A.

    2017-11-01

    Data of a magnetic susceptibility of ferro-and the ferrimagnetic particles of many technogenic, natural, special media are especially demanded for the solution of various tasks connected with purposeful magnetic impact on these particles. One of productive approaches to definition of a magnetic susceptibility χ of these particles consists in receiving experimental data of a susceptibility of disperse samples 〈 χ 〉 with a disperse phase of these particles. The paper expounds and analyses the results of experiments on defining (by Faraday method in a magnetic field with intensity H = 90-730 kA/m) the magnetic susceptibility 〈 χ 〉 of disperse samples (conglomerates) with a given volume ratio γ of magnetite particles (γ = 0.0065-0.25). The corresponding families of concentration and field dependences are provided alongside with discussing the applicability of linear and exponential functions to describe these dependences. We consider the possibility of defining single particles susceptibility χ (with simultaneous obtaining field dependence of this susceptibility) by the commonly used relation χ = 〈 χ 〉 /γ both at relatively small (preferable for accuracy reasons) values γ - to γ = 0.02…0.025, as well as at increased values γ - up to γ = 0.25. The data χ are provided depending on H and correlating with known data at H matter magnetic susceptibility χm (for the case when the particles are traditionally likened to balls with the characteristic for them demagnetising factor equalling 1/3) complies with the anticipated inverse function χm ∼ 1/H in the studied area H (where magnetization M expressed as M = χH reaches saturation M = Const).

  10. Putting prions into focus: application of single molecule detection to the diagnosis of prion diseases.

    Science.gov (United States)

    Giese, A; Bieschke, J; Eigen, M; Kretzschmar, H A

    2000-01-01

    Prion diseases are characterized by the cerebral deposition of an aggregated pathological isoform of the prion protein (PrP(Sc)) which constitutes the principal component of the transmissible agent termed prion. In order to develop a highly sensitive method for the detection of PrP(Sc) aggregates in biological samples such as cerebrospinal fluid (CSF), we used a method based on Fluorescence Correlation Spectroscopy (FCS), a technique which allows detection of single fluorescently labeled molecules in solution. Within the FCS setup, fluorescent photons emitted by molecules passing an open volume element defined by the beam of an excitation laser focussed into a diffraction-limited spot are imaged confocally onto a single photon counting detector. Aggregates of PrP(Sc) could be labeled by co-aggregation of probe molecules such as monomeric recombinant PrP or PrP-specific antibodies tagged with a fluorescent dye. In addition to slow diffusion, labeled aggregates are characterized by high fluorescence intensity, which allows detection and quantification by analysis of fluorescence intensity distribution. To improve detection of rare target particles, the accessible volume element was increased by scanning for intensely fluorescent targets (SIFT). To further improve sensitivity and specificity, two different probes were used simultaneously in a two-color setup. In a diagnostic model system of CSF spiked with purified prion rods, dual-color SIFT was more sensitive than Western blot analysis. In addition, a PrP(Sc)-specific signal was also detected in a number of CSF samples derived from CJD patients but not in controls.

  11. Role of bumpy fields on single particle orbit in near quasihelically symmetric stellarators

    International Nuclear Information System (INIS)

    Seol, JaeChun; Hegna, C.C.

    2004-01-01

    The role of symmetry breaking on single particle orbits in near helically symmetric stellarators is investigated. In particular, the effect of a symmetry-breaking bumpy term is included in the analysis of trapped particle orbits. It is found that all trapped particle drift orbits are determined by surfaces on which vertical bar B vertical bar min is constant. Trapped particle orbits reside on these surfaces regardless of pitch angle and are determined solely by the initial position and the shape of the vertical bar B vertical bar min contour. Since vertical bar B vertical bar min contours do not depend on the direction of the banana center motion, superbanana orbits do not appear

  12. ORBXYZ: a 3D single-particle orbit code for following charged-particle trajectories in equilibrium magnetic fields

    International Nuclear Information System (INIS)

    Anderson, D.V.; Cohen, R.H.; Ferguson, J.R.; Johnston, B.M.; Sharp, C.B.; Willmann, P.A.

    1981-01-01

    The single particle orbit code, TIBRO, has been modified extensively to improve the interpolation methods used and to allow use of vector potential fields in the simulation of charged particle orbits on a 3D domain. A 3D cubic B-spline algorithm is used to generate spline coefficients used in the interpolation. Smooth and accurate field representations are obtained. When vector potential fields are used, the 3D cubic spline interpolation formula analytically generates the magnetic field used to push the particles. This field has del.BETA = 0 to computer roundoff. When magnetic induction is used the interpolation allows del.BETA does not equal 0, which can lead to significant nonphysical results. Presently the code assumes quadrupole symmetry, but this is not an essential feature of the code and could be easily removed for other applications. Many details pertaining to this code are given on microfiche accompanying this report

  13. DECAY MODES OF HIGH-LYING SINGLE-PARTICLE STATES IN PB-209

    NARCIS (Netherlands)

    BEAUMEL, D; FORTIER, S; GALES, S; GUILLOT, J; LANGEVINJOLIOT, H; LAURENT, H; MAISON, JM; VERNOTTE, J; BORDEWIJK, JA; BRANDENBURG, S; KRASZNAHORKAY, A; CRAWLEY, GM; MASSOLO, CP; RENTERIA, M

    The neutron decay of high-lying single-particle states in Pb-209 excited by means of the (alpha, He-3) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high-spin values of these states, inferred from previous inclusive experiments, are confirmed by the

  14. Resonant pickups for non-destructive single-particle detection in heavy-ion storage rings and first experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Sanjari, Mohammad Shahab

    2013-04-26

    Nuclear astrophysics studies on highly charged radionuclides benefit from accelerator facilities with storage rings, where exotic nuclides produced with small yields can be efficiently investigated. Currently there are two accelerator facilities capable of storing highly charged heavy ions, GSI in Darmstadt and IMP in Lanzhou. Non-destructive detection methods are often used for in-flight measurements based on frequency analysis. The sensitivity of such detection systems are of primary importance specially when number of stored ions is small. Furthermore, since the exotic nuclides of interest are as a rule short-lived, the detectors must be fast. One common form of such detectors are parallel plate SCHOTTKY monitors, on which particles induce a mirror charge at each passage. This method has been successfully used at ESR experimental storage ring of GSI since 1991. In this work we describe a new resonant SCHOTTKY pickup operating as a high sensitive cavity current monitor which was mounted and commissioned in the ESR early 2010. It was successfully used in several storage ring experiments. A very similar pickup was mounted in CSRe at IMP Lanzhou in 2011. First in-ring tests have been performed and new experimental results are pending. The spectral analysis of acquired signals by the new detector has enabled a broad range of new physics experiments. The theory of operation and first experimental results and future perspectives are presented in this thesis.

  15. Resonant pickups for non-destructive single-particle detection in heavy-ion storage rings and first experimental results

    International Nuclear Information System (INIS)

    Sanjari, Mohammad Shahab

    2013-01-01

    Nuclear astrophysics studies on highly charged radionuclides benefit from accelerator facilities with storage rings, where exotic nuclides produced with small yields can be efficiently investigated. Currently there are two accelerator facilities capable of storing highly charged heavy ions, GSI in Darmstadt and IMP in Lanzhou. Non-destructive detection methods are often used for in-flight measurements based on frequency analysis. The sensitivity of such detection systems are of primary importance specially when number of stored ions is small. Furthermore, since the exotic nuclides of interest are as a rule short-lived, the detectors must be fast. One common form of such detectors are parallel plate SCHOTTKY monitors, on which particles induce a mirror charge at each passage. This method has been successfully used at ESR experimental storage ring of GSI since 1991. In this work we describe a new resonant SCHOTTKY pickup operating as a high sensitive cavity current monitor which was mounted and commissioned in the ESR early 2010. It was successfully used in several storage ring experiments. A very similar pickup was mounted in CSRe at IMP Lanzhou in 2011. First in-ring tests have been performed and new experimental results are pending. The spectral analysis of acquired signals by the new detector has enabled a broad range of new physics experiments. The theory of operation and first experimental results and future perspectives are presented in this thesis.

  16. Decay properties of high-lying single-particles modes

    Science.gov (United States)

    Beaumel, D.; Fortier, S.; Galès, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J. M.; Vernotte, J.; Bordewijck, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G. M.; Massolo, C. P.; Renteria, M.; Khendriche, A.

    1996-02-01

    The neutron decay of high-lying single-particle states in 64Ni, 90Zr, 120Sn and 208Pb excited by means of the (α, 3He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in 91Zr, and between 8 and 12 MeV excitation energy in 209Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations.

  17. Thermodynamics of phase-separating nanoalloys: Single particles and particle assemblies

    Science.gov (United States)

    Fèvre, Mathieu; Le Bouar, Yann; Finel, Alphonse

    2018-05-01

    The aim of this paper is to investigate the consequences of finite-size effects on the thermodynamics of nanoparticle assemblies and isolated particles. We consider a binary phase-separating alloy with a negligible atomic size mismatch, and equilibrium states are computed using off-lattice Monte Carlo simulations in several thermodynamic ensembles. First, a semi-grand-canonical ensemble is used to describe infinite assemblies of particles with the same size. When decreasing the particle size, we obtain a significant decrease of the solid/liquid transition temperatures as well as a growing asymmetry of the solid-state miscibility gap related to surface segregation effects. Second, a canonical ensemble is used to analyze the thermodynamic equilibrium of finite monodisperse particle assemblies. Using a general thermodynamic formulation, we show that a particle assembly may split into two subassemblies of identical particles. Moreover, if the overall average canonical concentration belongs to a discrete spectrum, the subassembly concentrations are equal to the semi-grand-canonical equilibrium ones. We also show that the equilibrium of a particle assembly with a prescribed size distribution combines a size effect and the fact that a given particle size assembly can adopt two configurations. Finally, we have considered the thermodynamics of an isolated particle to analyze whether a phase separation can be defined within a particle. When studying rather large nanoparticles, we found that the region in which a two-phase domain can be identified inside a particle is well below the bulk phase diagram, but the concentration of the homogeneous core remains very close to the bulk solubility limit.

  18. Inside versus Outside: Ion Redistribution in Nitric Acid Reacted Sea Spray Aerosol Particles as Determined by Single Particle Analysis (Invited)

    Science.gov (United States)

    Ault, A. P.; Guasco, T.; Ryder, O. S.; Baltrusaitis, J.; Cuadra-Rodriguez, L. A.; Collins, D. B.; Ruppel, M. J.; Bertram, T. H.; Prather, K. A.; Grassian, V. H.

    2013-12-01

    Sea spray aerosol (SSA) particles were generated under real-world conditions using natural seawater and a unique ocean-atmosphere facility equipped with actual breaking waves or a marine aerosol reference tank (MART) that replicates those conditions. The SSA particles were exposed to nitric acid in situ in a flow tube and the well-known chloride displacement and nitrate formation reaction was observed. However, as discussed here, little is known about how this anion displacement reaction affects the distribution of cations and other chemical constituents within and phase state of individual SSA particles. Single particle analysis of individual SSA particles shows that cations (Na+, K+, Mg2+ and Ca2+) within individual particles undergo a spatial redistribution after heterogeneous reaction with nitric acid, along with a more concentrated layer of organic matter at the surface of the particle. These data suggest that specific ion and aerosol pH effects play an important role in aerosol particle structure in ways that have not been previously recognized. The ordering of organic coatings can impact trace gas uptake, and subsequently impact trace gas budgets of O3 and NOx.

  19. Single-particle spectra and magnetic field effects within precursor superconductivity

    International Nuclear Information System (INIS)

    Pieri, P.; Pisani, L.; Strinati, G.C.; Perali, A.

    2004-01-01

    We study the single-particle spectra below the superconducting critical temperature from weak to strong coupling within a precursor superconductivity scenario. The spectral-weight function is obtained from a self-energy that includes pairing-fluctuations within a continuum model representing the hot spots of the Brillouin zone. The effects of strong magnetic fields on the pseudogap temperature are also discussed within the same scenario

  20. A superconducting microcalorimeter for low-flux detection of near-infrared single photons

    Energy Technology Data Exchange (ETDEWEB)

    Dreyling-Eschweiler, Jan

    2014-07-15

    This thesis covers the development and the characterization of a single photon detector based on a superconducting microcalorimeter. The detector development is motivated by the Any Light Particle Search II (ALPS II) experiment at DESY in Hamburg, which searches for weakly interacting sub-eV particles (WISPs). Therefore, a detection of low-fluxes of 1064 nm light is required. The work is divided in three analyses: the characterization of a milli-kelvin (mK) cryostat, the characterization of superconducting sensors for single photon detection, and the determination of dark count rates concerning 1064 nm signals. Firstly, an adiabatic demagnetization refrigerator (ADR) is characterized, which allows to reach mK-temperatures. During commissioning, the ADR cryostat is optimized and prepared to stably cool superconducting sensors at 80 mK±25 μK. It is found that sensors can be continuously operated for ∝20 h before recharging the system in <2 h. Furthermore, the adiabatic system reaches a chance of success of ∝80 % for a recharge without technical problems. Secondly, superconducting sensors are analyzed. The focus is on microcalorimetric transition-edge sensors (TESs) based on 20 nm Tungsten (W) films fabricated by the U.S. National Institute of Standards and Technology (NIST). NIST TESs have a near unity detection efficiency for 1064 nm light (literature value). The energy resolution for 1064 nm signals is measured to be <8 %. The exponential falling time of a photon pulse is 1.5 μs. Furthermore, by determining TES parameters, it is found that the linear TES theory describes measured photon pulses well. The TES response is read out by a superconducting quantum interference device (SQUID) fabricated by Physikalisch-Technische Bundesanstalt (PTB). The system bandwidth is measured to be 0.9 MHz. Finally, the operation in the ADR cryostat as well as the ALPS II laboratory is optimized. This setup forms the ALPS TES detector. Thirdly, the background is measured to

  1. Single particle level scheme for alpha decay

    International Nuclear Information System (INIS)

    Mirea, M.

    1998-01-01

    The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)

  2. Multiple sample, radioactive particle counting apparatus

    International Nuclear Information System (INIS)

    Reddy, R.R.V.; Kelso, D.M.

    1978-01-01

    An apparatus is described for determining the respective radioactive particle sample count being emitted from radioactive particle containing samples. It includes means for modulating the information on the radioactive particles being emitted from the samples, coded detecting means for sequentially detecting different respective coded combinations of the radioactive particles emitted from more than one but less than all of the samples, and processing the modulated information to derive the sample count for each sample. It includes a single light emitting crystal next to a number of samples, an encoder belt sequentially movable between the crystal and the samples. The encoder belt has a coded array of apertures to provide corresponding modulated light pulses from the crystal, and a photomultiplier tube to convert the modulated light pulses to decodable electrical signals for deriving the respective sample count

  3. Towards single particle imaging of human chromosomes at SACLA

    International Nuclear Information System (INIS)

    Robinson, Ian; Schwenke, Joerg; Yusuf, Mohammed; Estandarte, Ana; Zhang, Fucai; Chen, Bo; Clark, Jesse; Song, Changyong; Nam, Daewoong; Joti, Yasumasa; Tono, Kensuke; Yabashi, Makina; Ratnasari, Gina; Kaneyoshi, Kohei; Takata, Hideaki; Fukui, Kiichi

    2015-01-01

    Single particle imaging (SPI) is one of the front-page opportunities which were used to motivate the construction of the first x-ray free electron lasers (XFELs). SPI’s big advantage is that it avoids radiation damage to biological samples because the diffraction takes place in femtosecond single shots before any atomic motion can take place in the sample, hence before the onset of radiation damage. This is the ‘diffract before destruction’ theme, destruction being assured from the high x-ray doses used. This article reports our collaboration’s first attempt at SPI using the SACLA XFEL facility in June 2015. The report is limited to experience with the instrumentation and examples of data because we have not yet had time to invert them to images. (paper)

  4. Biological effects of single HZE-particles of the cosmic radiation: Free Flyer Biostack

    International Nuclear Information System (INIS)

    1989-01-01

    The Free Flyer Biostack is designed as a passive, longer term experiment for investigations into the dosimetry of cosmic HZE particles (high-charge energetic particles), the effects of single HZE particles on isolated biological samples, and the synergistic effects of conditions in space, as e.g. zero gravity and presence of a permanent, weakly ionizing component of the cosmic radiation. For the experiments summarized in this project report, the AgCl detector type developed in Frankfurt has been used, consisting of monocrystalline AgCl films, about 130-150 μm thick, and doped with 5000 ppm of Cd. (DG) With 9 figs [de

  5. Inversion of single-particle levels in nuclear Hartree-Fock and Brueckner-HF calculations with broken symmetry

    International Nuclear Information System (INIS)

    Becker, R.L.; Svenne, J.P.

    1975-12-01

    Energy levels of states connected by a symmetry of the Hamiltonian normally should be degenerate. In self-consistent field theories, when only one of a pair of single-particle levels connected by a symmetry of the full Hamiltonian is occupied, the degeneracy is split and the unoccupied level often lies below the occupied one. Inversions of neutron-proton (charge) and time-reversal doublets in odd nuclei, charge doublets in even nuclei with a neutron excess, and spin-orbit doublets in spherical configurations with spin-unsaturated shells are examined. The origin of the level inversion is investigated, and the following explanation offered. Unoccupied single-particle levels, from a calculation in an A-particle system, should be interpreted as levels of the (A + 1)-particle system. When the symmetry-related level, occupied in the A-particle system, is also calculated in the (A + 1)-particle system it is degenerate with or lies lower than the other. That is, when both levels are calculated in the (A + 1)-particle system, they are not inverted. It is demonstrated that the usual prescription to occupy the lowest-lying orbitals should be modified to refer to the single-particle energies calculated in the (A + 1)- or the (A - 1)-particle system. This observation is shown to provide a justification for avoiding an oscillation of occupancy between symmetry-related partners in successive iterations leading to a self-consistency. It is pointed out that two degenerate determinants arise from occupying one or the other partner of an initially degenerate pair of levels and then iterating to self-consistency. The existence of the degenerate determinants indicates the need for introducing correlations, either by mixing the two configurations or by allowing additional symmetry-breaking (resulting in a more highly deformed non-degenerate configuration). 2 figures, 3 tables, 43 references

  6. Indirect Charged Particle Detection: Concepts and a Classroom Demonstration

    Science.gov (United States)

    Childs, Nicholas B.; Horányi, Mihály; Collette, Andrew

    2013-01-01

    We describe the principles of macroscopic charged particle detection in the laboratory and their connections to concepts taught in the physics classroom. Electrostatic dust accelerator systems, capable of launching charged dust grains at hypervelocities (1-100 km/s), are a critical tool for space exploration. Dust grains in space typically have…

  7. SISGR: Room Temperature Single-Molecule Detection and Imaging by Stimulated Emission Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xiaoliang Sunney [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology

    2017-03-13

    Single-molecule spectroscopy has made considerable impact on many disciplines including chemistry, physics, and biology. To date, most single-molecule spectroscopy work is accomplished by detecting fluorescence. On the other hand, many naturally occurring chromophores, such as retinal, hemoglobin and cytochromes, do not have detectable fluorescence. There is an emerging need for single-molecule spectroscopy techniques that do not require fluorescence. In the last proposal period, we have successfully demonstrated stimulated emission microscopy, single molecule absorption, and stimulated Raman microscopy based on a high-frequency modulation transfer technique. These first-of-a- kind new spectroscopy/microscopy methods tremendously improved our ability to observe molecules that fluorescence weakly, even to the limit of single molecule detection for absorption measurement. All of these methods employ two laser beams: one (pump beam) excites a single molecule to a real or virtual excited state, and the other (probe beam) monitors the absorption/emission property of the single. We extract the intensity change of the probe beam with high sensitivity by implementing a high-frequency phase-sensitive detection scheme, which offers orders of magnitude improvement in detection sensitivity over direct absorption/emission measurement. However, single molecule detection based on fluorescence or absorption is fundamentally limited due to their broad spectral response. It is important to explore other avenues in single molecule detection and imaging which provides higher molecular specificity for studying a wide variety of heterogeneous chemical and biological systems. This proposal aimed to achieve single-molecule detection sensitivity with near resonance stimulated Raman scattering (SRS) microscopy. SRS microscopy was developed in our lab as a powerful technique for imaging heterogeneous samples based on their intrinsic vibrational contrasts, which provides much higher molecular

  8. Single particle characterization, source apportionment, and aging effects of ambient aerosols in Southern California

    Science.gov (United States)

    Shields, Laura Grace

    Composed of a mixture of chemical species and phases and existing in a variety of shapes and sizes, atmospheric aerosols are complex and can have serious influence on human health, the environment, and climate. In order to better understand the impact of aerosols on local to global scales, detailed measurements on the physical and chemical properties of ambient particles are essential. In addition, knowing the origin or the source of the aerosols is important for policymakers to implement targeted regulations and effective control strategies to reduce air pollution in their region. One of the most ground breaking techniques in aerosol instrumentation is single particle mass spectrometry (SPMS), which can provide online chemical composition and size information on the individual particle level. The primary focus of this work is to further improve the ability of one specific SPMS technique, aerosol time-of-flight mass spectrometry (ATOFMS), for the use of identifying the specific origin of ambient aerosols, which is known as source apportionment. The ATOFMS source apportionment method utilizes a library of distinct source mass spectral signatures to match the chemical information of the single ambient particles. The unique signatures are obtained in controlled source characterization studies, such as with the exhaust emissions of heavy duty diesel vehicles (HDDV) operating on a dynamometer. The apportionment of ambient aerosols is complicated by the chemical and physical processes an individual particle can undergo as it spends time in the atmosphere, which is referred to as "aging" of the aerosol. Therefore, the performance of the source signature library technique was investigated on the ambient dataset of the highly aged environment of Riverside, California. Additionally, two specific subsets of the Riverside dataset (ultrafine particles and particles containing trace metals), which are known to cause adverse health effects, were probed in greater detail. Finally

  9. Innovative molecular-based fluorescent nanoparticles for multicolor single particle tracking in cells

    International Nuclear Information System (INIS)

    Daniel, Jonathan; Blanchard-Desce, Mireille; Godin, Antoine G; Palayret, Matthieu; Lounis, Brahim; Cognet, Laurent

    2016-01-01

    Based on an original molecular-based design, we present bright and photostable fluorescent organic nanoparticles (FONs) showing excellent colloidal stability in various aqueous environments. Complementary near-infrared emitting and green emitting FONs were prepared using a simple, fast and robust protocol. Both types of FONs could be simultaneously imaged at the single-particle level in solution as well as in biological environments using a monochromatic excitation and a dual-color fluorescence microscope. No evidence of acute cytotoxicity was found upon incubation of live cells with mixed solutions of FONs, and both types of nanoparticles were found internalized in the cells where their motion could be simultaneously tracked at video-rate up to minutes. These fluorescent organic nanoparticles open a novel non-toxic alternative to existing nanoparticles for imaging biological structures, compatible with live-cell experiments and specially fitted for multicolor single particle tracking. (paper)

  10. The influence of transport phenomena on the fluidized bed combustion of a single carbon particle

    NARCIS (Netherlands)

    Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1990-01-01

    The burning rate and temperature of the carbon particles are known to affect the efficiency of a fluidized bed combustor, and also the emission levels of undesired noxious components. The main results of an extensive study on the fluidized bed combustion behaviour of a single carbon particle [1] are

  11. Determination of alpha particle detection efficiency of an imaging plate (IP) detector

    International Nuclear Information System (INIS)

    Rahman, N.M; Iida, Takao; Yamazawa, Hiromi; Moriizumi, Jun

    2006-01-01

    In order to determine the detection efficiency of the imaging plate (IP) detector, the true radioactivity of the alpha particles, which sampled in the collection media, should be known. The true radioactivity could be accurately predicted with the help of the reference alpha spectrometer measurement. The detection efficiency calculated for the IP was estimated with the theoretical curve and the experimental data. It is assumed that the air sample contained the decay products of both 222 Rn and 220 Rn series, the most significant sources of alpha particles. The present study estimated the detection efficiency of the IP as 39.3% with an uncertainty of 2.9 that is well enough to confirm the future use of the IP as a radiation detector. Experimental materials and methods are described. (S.Y.)

  12. Online differentiation of mineral phase in aerosol particles by ion formation mechanism using a LAAP-TOF single-particle mass spectrometer

    Science.gov (United States)

    Marsden, Nicholas A.; Flynn, Michael J.; Allan, James D.; Coe, Hugh

    2018-01-01

    Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS) is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI) followed by time-of-flight mass spectrometry (TOF-MS). Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.In this study, we introduce a novel technique that enables the differentiation of mineral phase in silicate mineral particles by ion formation mechanism measured from subtle changes in ion arrival times at the TOF-MS detector. Using a combination of peak area and peak centroid measurements, we show that the arrangement of the interstitial alkali metals in the crystal structure, an important property in silicate mineralogy, influences the ion arrival times of elemental and molecular ion species in the negative ion mass spectra. A classification scheme is presented that allowed for the differentiation of illite-smectite, kaolinite and feldspar minerals on a single-particle basis. Online analysis of mineral dust aerosol generated from clay mineral standards produced mineral fractions that are in agreement with bulk measurements reported by

  13. cisTEM, user-friendly software for single-particle image processing

    Science.gov (United States)

    2018-01-01

    We have developed new open-source software called cisTEM (computational imaging system for transmission electron microscopy) for the processing of data for high-resolution electron cryo-microscopy and single-particle averaging. cisTEM features a graphical user interface that is used to submit jobs, monitor their progress, and display results. It implements a full processing pipeline including movie processing, image defocus determination, automatic particle picking, 2D classification, ab-initio 3D map generation from random parameters, 3D classification, and high-resolution refinement and reconstruction. Some of these steps implement newly-developed algorithms; others were adapted from previously published algorithms. The software is optimized to enable processing of typical datasets (2000 micrographs, 200 k – 300 k particles) on a high-end, CPU-based workstation in half a day or less, comparable to GPU-accelerated processing. Jobs can also be scheduled on large computer clusters using flexible run profiles that can be adapted for most computing environments. cisTEM is available for download from cistem.org. PMID:29513216

  14. cisTEM, user-friendly software for single-particle image processing.

    Science.gov (United States)

    Grant, Timothy; Rohou, Alexis; Grigorieff, Nikolaus

    2018-03-07

    We have developed new open-source software called cis TEM (computational imaging system for transmission electron microscopy) for the processing of data for high-resolution electron cryo-microscopy and single-particle averaging. cis TEM features a graphical user interface that is used to submit jobs, monitor their progress, and display results. It implements a full processing pipeline including movie processing, image defocus determination, automatic particle picking, 2D classification, ab-initio 3D map generation from random parameters, 3D classification, and high-resolution refinement and reconstruction. Some of these steps implement newly-developed algorithms; others were adapted from previously published algorithms. The software is optimized to enable processing of typical datasets (2000 micrographs, 200 k - 300 k particles) on a high-end, CPU-based workstation in half a day or less, comparable to GPU-accelerated processing. Jobs can also be scheduled on large computer clusters using flexible run profiles that can be adapted for most computing environments. cis TEM is available for download from cistem.org. © 2018, Grant et al.

  15. Optimal state discrimination using particle statistics

    International Nuclear Information System (INIS)

    Bose, S.; Ekert, A.; Omar, Y.; Paunkovic, N.; Vedral, V.

    2003-01-01

    We present an application of particle statistics to the problem of optimal ambiguous discrimination of quantum states. The states to be discriminated are encoded in the internal degrees of freedom of identical particles, and we use the bunching and antibunching of the external degrees of freedom to discriminate between various internal states. We show that we can achieve the optimal single-shot discrimination probability using only the effects of particle statistics. We discuss interesting applications of our method to detecting entanglement and purifying mixed states. Our scheme can easily be implemented with the current technology

  16. Single molecule DNA detection with an atomic vapor notch filter

    Energy Technology Data Exchange (ETDEWEB)

    Uhland, Denis; Rendler, Torsten; Widmann, Matthias; Lee, Sang-Yun [University of Stuttgart and Stuttgart Research Center of Photonic Engineering (SCoPE) and IQST, 3rd Physics Institute, Stuttgart (Germany); Wrachtrup, Joerg; Gerhardt, Ilja [University of Stuttgart and Stuttgart Research Center of Photonic Engineering (SCoPE) and IQST, 3rd Physics Institute, Stuttgart (Germany); Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2015-12-01

    The detection of single molecules has facilitated many advances in life- and material-science. Commonly the fluorescence of dye molecules is detected, which are attached to a non-fluorescent structure under study. For fluorescence microscopy one desires to maximize the detection efficiency together with an efficient suppression of undesired laser leakage. Here we present the use of the narrow-band filtering properties of hot atomic sodium vapor to selectively filter the excitation light from the red-shifted fluorescence of dye labeled single-stranded DNA molecules. A statistical analysis proves an enhancement in detection efficiency of more than 15% in a confocal and in a wide-field configuration. (orig.)

  17. Single-cell multiple gene expression analysis based on single-molecule-detection microarray assay for multi-DNA determination

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lu [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang, Xianwei [School of Life Sciences, Shandong University, Jinan 250100 (China); Zhang, Xiaoli [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Wang, Jinxing [School of Life Sciences, Shandong University, Jinan 250100 (China); Jin, Wenrui, E-mail: jwr@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2015-01-07

    Highlights: • A single-molecule-detection (SMD) microarray for 10 samples is fabricated. • The based-SMD microarray assay (SMA) can determine 8 DNAs for each sample. • The limit of detection of SMA is as low as 1.3 × 10{sup −16} mol L{sup −1}. • The SMA can be applied in single-cell multiple gene expression analysis. - Abstract: We report a novel ultra-sensitive and high-selective single-molecule-detection microarray assay (SMA) for multiple DNA determination. In the SMA, a capture DNA (DNAc) microarray consisting of 10 subarrays with 9 spots for each subarray is fabricated on a silanized glass coverslip as the substrate. On the subarrays, the spot-to-spot spacing is 500 μm and each spot has a diameter of ∼300 μm. The sequence of the DNAcs on the 9 spots of a subarray is different, to determine 8 types of target DNAs (DNAts). Thus, 8 types of DNAts are captured to their complementary DNAcs at 8 spots of a subarray, respectively, and then labeled with quantum dots (QDs) attached to 8 types of detection DNAs (DNAds) with different sequences. The ninth spot is used to detect the blank value. In order to determine the same 8 types of DNAts in 10 samples, the 10 DNAc-modified subarrays on the microarray are identical. Fluorescence single-molecule images of the QD-labeled DNAts on each spot of the subarray are acquired using a home-made single-molecule microarray reader. The amounts of the DNAts are quantified by counting the bright dots from the QDs. For a microarray, 8 types of DNAts in 10 samples can be quantified in parallel. The limit of detection of the SMA for DNA determination is as low as 1.3 × 10{sup −16} mol L{sup −1}. The SMA for multi-DNA determination can also be applied in single-cell multiple gene expression analysis through quantification of complementary DNAs (cDNAs) corresponding to multiple messenger RNAs (mRNAs) in single cells. To do so, total RNA in single cells is extracted and reversely transcribed into their cDNAs. Three

  18. A Mathematical Model of the Single Aluminium Diboride Particle Ignition

    Directory of Open Access Journals (Sweden)

    D. A. Yagodnikov

    2014-01-01

    Full Text Available The paper presents a developed mathematical model of ignition of the single aluminum diboride particle as an aluminum-boron alloy in the oxidizing environment of a complicated chemical composition containing oxygen, water vapor, and carbon dioxide. The mathematical model is based on the theory of parallel chemical reactions proceeding on the appropriate parts of the particle surface occupied by each element in proportion to their molar share in the alloy. The paper considers a possibility to establish a thermodynamic balance between components over a particle surface in the gas phase. The composition of components is chosen as a result of thermodynamic calculation, namely В g , B2O3 g , BO, B2O2, BO2, Alg , AlO, Al2O, N2. The mathematical model is formed by a system of the differential equations of enthalpy balance, mass of aluminum diboride particle, and of formed oxides, which become isolated by initial and boundary conditions for temperature and size of particles, concentration of an oxidizer, and temperature of gas. The software package “AlB2“ is developed. It is a complete independent module written in Fortran algorithmic language, which together with a package of the subroutines “SPARKS” is used to calculate parameters of burning aluminum diboride particle by the Runge-Kutt method.For stoichiometry of chemical reactions of interaction between aluminum diboride and oxygen, a dynamics of changing temperature of a particle and thickness of an oxide film on its surface is calculated. It was admitted as initial conditions that the aluminum diboride particle radius was 100μ and the reference temperature of environment was 500 K, 1000 K, 2300 K, and 3000 K. Depending on this temperature the aluminum diboride particle temperature was calculated. Changing thickness of the oxide film on the particle surface at various initial gas temperatures characterizes its increase at the initial heating period of ~ 0,01 s and a gradual slowdown of the

  19. Decay properties of high-lying single-particles modes

    Energy Technology Data Exchange (ETDEWEB)

    Beaumel, D. [Institut de Physique Nucleaire, 91 - Orsay (France); Fortier, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Gales, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Guillot, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Langevin-Joliot, H. [Institut de Physique Nucleaire, 91 - Orsay (France); Laurent, H. [Institut de Physique Nucleaire, 91 -Orsay (France); Maison, J.M. [Institut de Physique Nucleaire, 91 - Orsay (France); Vernotte, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Bordewijck, J. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Brandenburg, S. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Krasznahorkay, A. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Crawley, G.M. [NSCL, Michigan State University, East Lansing, MI 48824 (United States); Massolo, C.P. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Renteria, M. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Khendriche, A. [University of Tizi-Ouzou, Tizi-Ouzou (Algeria)

    1996-03-18

    The neutron decay of high-lying single-particle states in {sup 64}Ni, {sup 90}Zr, {sup 120}Sn and {sup 208}Pb excited by means of the ({alpha},{sup 3}He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in {sup 91}Zr, and between 8 and 12 MeV excitation energy in {sup 209}Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations. (orig.).

  20. Chaos and nonlinear dynamics of single-particle orbits in a magnetotaillike magnetic field

    Science.gov (United States)

    Chen, J.; Palmadesso, P. J.

    1986-01-01

    The properties of charged-particle motion in Hamiltonian dynamics are studied in a magnetotaillike magnetic field configuration. It is shown by numerical integration of the equation of motion that the system is generally nonintegrable and that the particle motion can be classified into three distinct types of orbits: bounded integrable orbits, unbounded stochastic orbits, and unbounded transient orbits. It is also shown that different regions of the phase space exhibit qualitatively different responses to external influences. The concept of 'differential memory' in single-particle distributions is proposed. Physical implications for the dynamical properties of the magnetotail plasmas and the possible generation of non-Maxwellian features in the distribution functions are discussed.

  1. Measurement of ambient aerosols in northern Mexico City by single particle mass spectrometry

    Directory of Open Access Journals (Sweden)

    R. C. Moffet

    2008-08-01

    Full Text Available Continuous ambient measurements with aerosol time-of-flight mass spectrometry (ATOFMS were made in an industrial/residential section in the northern part of Mexico City as part of the Mexico City Metropolitan Area-2006 campaign (MCMA-2006. Results are presented for the period of 15–27 March 2006. The submicron size mode contained both fresh and aged biomass burning, aged organic carbon (OC mixed with nitrate and sulfate, elemental carbon (EC, nitrogen-organic carbon, industrial metal, and inorganic NaK inorganic particles. Overall, biomass burning and aged OC particle types comprised 40% and 31%, respectively, of the submicron mode. In contrast, the supermicron mode was dominated by inorganic NaK particle types (42% which represented a mixture of dry lake bed dust and industrial NaK emissions mixed with soot. Additionally, aluminosilicate dust, transition metals, OC, and biomass burning contributed to the supermicron particles. Early morning periods (2–6 a.m. showed high fractions of inorganic particles from industrial sources in the northeast, composed of internal mixtures of Pb, Zn, EC and Cl, representing up to 73% of the particles in the 0.2–3μm size range. A unique nitrogen-containing organic carbon (NOC particle type, peaking in the early morning hours, was hypothesized to be amines from local industrial emissions based on the time series profile and back trajectory analysis. A strong dependence on wind speed and direction was observed in the single particle types that were present during different times of the day. The early morning (3:30–10 a.m. showed the greatest contributions from industrial emissions. During mid to late mornings (7–11 a.m., weak northerly winds were observed along with the most highly aged particles. Stronger winds from the south picked up in the late morning (after 11 a.m., resulting in a decrease in the concentrations of the major aged particle types and an increase in the number fraction of fresh

  2. A single particle energies

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1993-09-01

    We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.

  3. Fault detection and isolation in GPS receiver autonomous integrity monitoring based on chaos particle swarm optimization-particle filter algorithm

    Science.gov (United States)

    Wang, Ershen; Jia, Chaoying; Tong, Gang; Qu, Pingping; Lan, Xiaoyu; Pang, Tao

    2018-03-01

    The receiver autonomous integrity monitoring (RAIM) is one of the most important parts in an avionic navigation system. Two problems need to be addressed to improve this system, namely, the degeneracy phenomenon and lack of samples for the standard particle filter (PF). However, the number of samples cannot adequately express the real distribution of the probability density function (i.e., sample impoverishment). This study presents a GPS receiver autonomous integrity monitoring (RAIM) method based on a chaos particle swarm optimization particle filter (CPSO-PF) algorithm with a log likelihood ratio. The chaos sequence generates a set of chaotic variables, which are mapped to the interval of optimization variables to improve particle quality. This chaos perturbation overcomes the potential for the search to become trapped in a local optimum in the particle swarm optimization (PSO) algorithm. Test statistics are configured based on a likelihood ratio, and satellite fault detection is then conducted by checking the consistency between the state estimate of the main PF and those of the auxiliary PFs. Based on GPS data, the experimental results demonstrate that the proposed algorithm can effectively detect and isolate satellite faults under conditions of non-Gaussian measurement noise. Moreover, the performance of the proposed novel method is better than that of RAIM based on the PF or PSO-PF algorithm.

  4. NA49 Results on Single Particle and Correlation Measurements in Central PB+PB Collisions

    CERN Document Server

    Wang, Fuqiang; Bachler, J.; Bailey, S.J.; Barna, D.; Barnby, L.S.; Bartke, J.; Barton, R.A.; Bialkowska, H.; Billmeier, A.; Blyth, C.O.; Bock, R.; Boimska, B.; Bormann, C.; Brady, F.P.; Brockmann, R.; Brun, R.; Buncic, P.; Caines, H.L.; Carr, L.D.; Cebra, D.A.; Cooper, G.E.; Cramer, J.G.; Cristinziani, M.; Csato, P.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Ferguson, M.I.; Fischer, H.G.; Flierl, D.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Fuchs, M.; Gabler, F.; Gal, J.; Ganz, R.; Gazdzicki, M.; Gladysz, E.; Grebieszkow, J.; Gunther, J.; Harris, J.W.; Hegyi, S.; Henkel, T.; Hill, L.A.; Hummler, H.; Igo, G.; Irmscher, D.; Jacobs, P.; Jones, P.G.; Kadija, K.; Kolesnikov, V.I.; Kowalski, M.; Lasiuk, B.; Levai, P.; Malakhov, A.I.; Margetis, S.; Markert, C.; Melkumov, G.L.; Mock, A.; Molnar, J.; Nelson, John M.; Oldenburg, M.; Odyniec, G.; Palla, G.; Panagiotou, A.D.; Petridis, A.; Piper, A.; Porter, R.J.; Poskanzer, Arthur M.; Prindle, D.J.; Puhlhofer, F.; Rauch, W.; Reid, J.G.; Renfordt, R.; Retyk, W.; Ritter, H.G.; Rohrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sandoval, A.; Sann, H.; Semenov, A.Yu.; Schafer, E.; Schmischke, D.; Schmitz, N.; Schonfelder, S.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Skrzypczak, E.; Snellings, R.; Squier, G.T.A.; Stock, R.; Strobele, H.; Struck, C.; Szentpetery, I.; Sziklai, J.; Toy, M.; Trainor, T.A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Veres, G.; Vesztergombi, G.; Voloshin, S.; Vranic, D.; Weerasundara, D.D.; Wenig, S.; Whitten, C.; Wienold, T.; Wood, L.; Xu, N.; Yates, T.A.; Zimanyi, J.; Zhu, X.Z.; Zybert, R.; Wang, Fuqiang

    2000-01-01

    Single-particle spectra and two-particle correlation functions measured by the NA49 collaboration in central Pb+Pb collisions at 158 GeV/nucleon are presented. These measurements are used to study the kinetic and chemical freeze-out conditions in heavy ion collisions. We conclude that large baryon stopping, high baryon density and strong transverse radial flow are achieved in central Pb+Pb collisions at the SPS.

  5. To the evaluation of single-particle strengths of states

    International Nuclear Information System (INIS)

    Ochirbat, G.

    1976-01-01

    Method of Green's function has been applied to calculating the distribution of single-particle states over actual nuclear levels. Chain of equations for these functions has been obtained in a model of interacting phonons and quasiparticles. It has been noticed that cutting the chain of equations by means of neglecting the higher order Green function corresponds to neglecting the higher order components of the wave function in variational methods. The one- and two-phonon approximations are discussed and the convenience of the Green function method for this case is demonstrated

  6. Single Nanoparticle Plasmonic Sensors

    Directory of Open Access Journals (Sweden)

    Manish Sriram

    2015-10-01

    Full Text Available The adoption of plasmonic nanomaterials in optical sensors, coupled with the advances in detection techniques, has opened the way for biosensing with single plasmonic particles. Single nanoparticle sensors offer the potential to analyse biochemical interactions at a single-molecule level, thereby allowing us to capture even more information than ensemble measurements. We introduce the concepts behind single nanoparticle sensing and how the localised surface plasmon resonances of these nanoparticles are dependent upon their materials, shape and size. Then we outline the different synthetic approaches, like citrate reduction, seed-mediated and seedless growth, that enable the synthesis of gold and silver nanospheres, nanorods, nanostars, nanoprisms and other nanostructures with tunable sizes. Further, we go into the aspects related to purification and functionalisation of nanoparticles, prior to the fabrication of sensing surfaces. Finally, the recent developments in single nanoparticle detection, spectroscopy and sensing applications are discussed.

  7. Efficiencies of dynamic Monte Carlo algorithms for off-lattice particle systems with a single impurity

    KAUST Repository

    Novotny, M.A.

    2010-02-01

    The efficiency of dynamic Monte Carlo algorithms for off-lattice systems composed of particles is studied for the case of a single impurity particle. The theoretical efficiencies of the rejection-free method and of the Monte Carlo with Absorbing Markov Chains method are given. Simulation results are presented to confirm the theoretical efficiencies. © 2010.

  8. Fourier Transform Near Infrared Microspectroscopy, Infrared Chemical Imaging, High-Resolution Nuclear Magnetic Resonance and Fluorescence Microspectroscopy Detection of Single Cancer Cells and Single Viral Particles

    CERN Document Server

    Baianu,I C; Hofmann, N E; Korban, S S; Lozano, P; You, T

    2004-01-01

    Single Cancer Cells from Human tumors are being detected and imaged by Fourier Transform Infrared (FT-IR), Fourier Transform Near Infrared (FT-NIR)Hyperspectral Imaging and Fluorescence Correlation Microspectroscopy. The first FT-NIR chemical, microscopic images of biological systems approaching one micron resolution are here reported. Chemical images obtained by FT-NIR and FT-IR Microspectroscopy are also presented for oil in soybean seeds and somatic embryos under physiological conditions. FT-NIR spectra of oil and proteins were obtained for volumes as small as two cubic microns. Related, HR-NMR analyses of oil contents in somatic embryos as well as 99% accurate calibrations are also presented here with nanoliter precision. Such high-resolution, 400 MHz H-1 NMR analyses allowed the selection of mutagenized embryos with higher oil content (e.g. >~20%) compared to the average levels in non-mutagenized control embryos. Moreover, developmental changes in single soybean seeds and/or somatic embryos may be monito...

  9. Numerical analysis of single particle impact in the context of Cold Spray: a new adhesion model

    Science.gov (United States)

    Profizi, P.; Combescure, A.; Ogawa, K.

    2016-03-01

    A new adhesion model for numerical simulation of single particle impact in the context of Cold Spray is introduced. As in other studies, cohesive forces are put between the particle and substrate to account for adhesion. In this study however, the forces are put only when a local physical criterion is met. The physical phenomenon most often attributed to Cold Spray adhesion is a shear stress instability. The Johnson-Cook material law is used with a shear damage softening law to enable strong localization at the interface without the need for an extremely fine mesh. This localization is then detected as a drop in local yield stress value by the algorithm, which then implements a local cohesive force. The evolution of this cohesive force is defined by an energy dissipative cohesive model, using a surface adhesion energy as a material parameter. Each cohesive link is broken once all its associated surface energy is dissipated. A criterion on the damage value is also used to break a cohesive bond prematurely, to account for the effect of erosion at higher speeds. This model is found to reproduce the Cold Spray-like adhesion behavior with observed critical and maximum speeds.

  10. Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry

    International Nuclear Information System (INIS)

    Adolphi, Natalie L; Huber, Dale L; Monson, Todd C; Provencio, Paula P; Bryant, Howard C; Fegan, Danielle L; Tessier, Trace E; Flynn, Edward R; Lim, JitKang; Majetich, Sara A; Trujillo, Jason E; Lovato, Debbie M; Butler, Kimberly S; Larson, Richard S; Hathaway, Helen J

    2010-01-01

    Optimizing the sensitivity of SQUID (superconducting quantum interference device) relaxometry for detecting cell-targeted magnetic nanoparticles for in vivo diagnostics requires nanoparticles with a narrow particle size distribution to ensure that the Neel relaxation times fall within the measurement timescale (50 ms-2 s, in this work). To determine the optimum particle size, single-core magnetite nanoparticles (with nominal average diameters 20, 25, 30 and 35 nm) were characterized by SQUID relaxometry, transmission electron microscopy, SQUID susceptometry, dynamic light scattering and zeta potential analysis. The SQUID relaxometry signal (detected magnetic moment/kg) from both the 25 nm and 30 nm particles was an improvement over previously studied multi-core particles. However, the detected moments were an order of magnitude lower than predicted based on a simple model that takes into account the measured size distributions (but neglects dipolar interactions and polydispersity of the anisotropy energy density), indicating that improved control of several different nanoparticle properties (size, shape and coating thickness) will be required to achieve the highest detection sensitivity. Antibody conjugation and cell incubation experiments show that single-core particles enable a higher detected moment per cell, but also demonstrate the need for improved surface treatments to mitigate aggregation and improve specificity.

  11. Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry

    Energy Technology Data Exchange (ETDEWEB)

    Adolphi, Natalie L [Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131 (United States); Huber, Dale L; Monson, Todd C; Provencio, Paula P [Sandia National Laboratories, P. O. Box 5800, Albuquerque, NM 87185 (United States); Bryant, Howard C; Fegan, Danielle L; Tessier, Trace E; Flynn, Edward R [Senior Scientific, LLC, 11109 Country Club NE, Albuquerque, NM 87111 (United States); Lim, JitKang; Majetich, Sara A [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Trujillo, Jason E; Lovato, Debbie M; Butler, Kimberly S; Larson, Richard S [Department of Pathology, Cancer Research and Treatment Center, University of New Mexico, Albuquerque, NM 87131 (United States); Hathaway, Helen J, E-mail: NAdolphi@salud.unm.ed [Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM 87131 (United States)

    2010-10-07

    Optimizing the sensitivity of SQUID (superconducting quantum interference device) relaxometry for detecting cell-targeted magnetic nanoparticles for in vivo diagnostics requires nanoparticles with a narrow particle size distribution to ensure that the Neel relaxation times fall within the measurement timescale (50 ms-2 s, in this work). To determine the optimum particle size, single-core magnetite nanoparticles (with nominal average diameters 20, 25, 30 and 35 nm) were characterized by SQUID relaxometry, transmission electron microscopy, SQUID susceptometry, dynamic light scattering and zeta potential analysis. The SQUID relaxometry signal (detected magnetic moment/kg) from both the 25 nm and 30 nm particles was an improvement over previously studied multi-core particles. However, the detected moments were an order of magnitude lower than predicted based on a simple model that takes into account the measured size distributions (but neglects dipolar interactions and polydispersity of the anisotropy energy density), indicating that improved control of several different nanoparticle properties (size, shape and coating thickness) will be required to achieve the highest detection sensitivity. Antibody conjugation and cell incubation experiments show that single-core particles enable a higher detected moment per cell, but also demonstrate the need for improved surface treatments to mitigate aggregation and improve specificity.

  12. Toward single-mode random lasing within a submicrometre-sized spherical ZnO particle film

    International Nuclear Information System (INIS)

    Niyuki, Ryo; Fujiwara, Hideki; Sasaki, Keiji; Ishikawa, Yoshie; Koshizaki, Naoto; Tsuji, Takeshi

    2016-01-01

    We had recently reported unique random laser action such as quasi-single-mode and low-threshold lasing from a submicrometre-sized spherical ZnO nanoparticle film with polymer particles as defects. The present study demonstrates a novel approach to realize single-mode random lasing by adjusting the sizes of the defect particles. From the dependence of random lasing properties on defect size, we find that the average number of lasing peaks can be modified by the defect size, while other lasing properties such as lasing wavelengths and thresholds remain unchanged. These results suggest that lasing wavelengths and thresholds are determined by the resonant properties of the surrounding scatterers, while the defect size stochastically determines the number of lasing peaks. Therefore, if we optimize the sizes of the defects and scatterers, we can intentionally induce single-mode lasing even in a random structure (Fujiwara et al 2013 Appl. Phys. Lett. 102 061110). (paper)

  13. Scintillating optical fibres and the detection of very short lived particles

    International Nuclear Information System (INIS)

    Fisher, C.M.

    1985-01-01

    The application of scintillating fiber optics to the problem of heavy flavour particle detection in both fixed target and collider experiments is reviewed. Brief specifications for both fibres and read-out systems are given. (orig.)

  14. Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV

    International Nuclear Information System (INIS)

    Koontz, R.W.

    1980-01-01

    Results of an experimental study of the interaction of 140 MeV alpha particles with 90 Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from 90 Zr(α,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. The second largest observed coincidence yield involving two charged fragments arises from 90 Zr(α,pd)X reactions, where the p and d fragments, as in the 90 Zr(α,pp)X reactions also have energy distribution similar to the singles energy distributions. Analysis of additional measurements, where alpha particle fragments at the fixed angle are detected in coincidence with evaporation and nonequilibrium particles at many coplanar angles, show that the alpha particle fragmentation reactions are also generally associated with large energy transfer to the target nucleus. A multiple scattering model of the fragmentation reaction is employed, in conjunction with the experimental observations, to estimate the cross sections for alpha particle fragmentation into multi-particle final states resulting in n, 2n, p, pp, d, dn, dp, t and 3 He fragments. The estimated total cross section for all fragmentation reactions is 755 mb or approximately 38% of the total reaction cross section for 140 MeV alpha particle interactions with 90 Zr

  15. Spin-lock MR enhances the detection sensitivity of superparamagnetic iron oxide particles

    NARCIS (Netherlands)

    Moonen, R.P.M.; van der Tol, P.; Hectors, S.J.C.G.; Starmans, L.W.E.; Nicolaij, K.; Strijkers, G.J.

    2015-01-01

    Purpose To evaluate spin-lock MR for detecting superparamagnetic iron oxides and compare the detection sensitivity of quantitative T1ρ with T2 imaging. Methods In vitro experiments were performed to investigate the influence of iron oxide particle size and composition on T1ρ. These comprise T1ρ and

  16. Spin-lock MR enhances the detection sensitivity of superparamagnetic iron oxide particles

    NARCIS (Netherlands)

    Moonen, Rik P. M.; van der Tol, Pieternel; Hectors, Stefanie J. C. G.; Starmans, Lucas W. E.; Nicolay, Klaas; Strijkers, Gustav J.

    2015-01-01

    To evaluate spin-lock MR for detecting superparamagnetic iron oxides and compare the detection sensitivity of quantitative T1ρ with T2 imaging. In vitro experiments were performed to investigate the influence of iron oxide particle size and composition on T1ρ . These comprise T1ρ and T2 measurements

  17. Search for long-lived massive particles with the ATLAS detector

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Numerous new physics models predict the existence of massive long-lived particles. Such particles may be produced at the LHC singly or in pairs, and can be detected through abnormal specific energy loss, long time-of-flight, late calorimetric energy deposits, disappearing tracks or displaced vertices. The seminar presents the experimental challenges and recent results from searches for long-lived particles with the ATLAS detector.

  18. [Particle Size and Number Density Online Analysis for Particle Suspension with Polarization-Differentiation Elastic Light Scattering Spectroscopy].

    Science.gov (United States)

    Chen, Wei-kang; Fang, Hui

    2016-03-01

    The basic principle of polarization-differentiation elastic light scattering spectroscopy based techniques is that under the linear polarized light incidence, the singlely scattered light from the superficial biological tissue and diffusively scattered light from the deep tissue can be separated according to the difference of polarization characteristics. The novel point of the paper is to apply this method to the detection of particle suspension and, to realize the simultaneous measurement of its particle size and number density in its natural status. We design and build a coaxial cage optical system, and measure the backscatter signal at a specified angle from a polystyrene microsphere suspension. By controlling the polarization direction of incident light with a linear polarizer and adjusting the polarization direction of collected light with another linear polarizer, we obtain the parallel polarized elastic light scattering spectrum and cross polarized elastic light scattering spectrum. The difference between the two is the differential polarized elastic light scattering spectrum which include only the single scattering information of the particles. We thus compare this spectrum to the Mie scattering calculation and extract the particle size. We then also analyze the cross polarized elastic light scattering spectrum by applying the particle size already extracted. The analysis is based on the approximate expressions taking account of light diffusing, from which we are able to obtain the number density of the particle suspension. We compare our experimental outcomes with the manufacturer-provided values and further analyze the influence of the particle diameter standard deviation on the number density extraction, by which we finally verify the experimental method. The potential applications of the method include the on-line particle quality monitoring for particle manufacture as well as the fat and protein density detection of milk products.

  19. Application of CTOF method to detect secondly charged particle from 2 GeV electron

    International Nuclear Information System (INIS)

    Takahashi, Kazutoshi; Sanami, Toshiya; Ban, Syuichi; Lee, Hee-Seok; Sato, Tatsuhiko

    2002-01-01

    To design a shield and evaluate leakage radiation at high energy electron accelerators, the energy and angular data of secondary particle from the reaction of electrons with structural materials are required. Secondly neutron spectrum from structural materials has been measured by using electron accelerator in PAL (Pohang Accelerator Laboratory). In the neutron measurement, the electronics with Multi-hit TDC (MHTDC) was adopted to measure Time of Flight of every particles (TOFs) emitted from the reactions by each single electron bunch. The measurements are extended to secondly charged particles. For the charged particles measurement, the pulse height data for every particles are indispensable to distinguish charged particles by Δ E-E method. A new system which can measure pulse height for every particle is required instead of the MHTDC system. For this requirement, the method which can take output current from detectors was developed by using digital storage oscilloscope system is named ''Current Time of Flight method'' (CTOF). The CTOF method is able to measure pulse height and TOF for every particles produced by single electron bunch. Electrons are accelerated to 2.04 GeV and the repetition rate is 10 Hz. These electrons bombard thin disk samples of Cu 1mm, Al 4 mm and W 0.5 mm. Secondly charged particles, proton and deuteron, are produced in the samples by photonuclear reaction. Two dimensional of Δ E-E spectrum for each the samples measured by CTOF shows separation between proton and deuteron perfectly. Thus, proton and deuteron spectrum are obtained from this data. (M. Suetake)

  20. An integrated micro-chip for rapid detection of magnetic particles

    KAUST Repository

    Gooneratne, Chinthaka P.

    2012-03-09

    This paper proposes an integrated micro-chip for the manipulation and detection of magnetic particles (MPs). A conducting ring structure is used to manipulate MPs toward giant magnetoresistance(GMR) sensing elements for rapid detection. The GMRsensor is fabricated in a horseshoe shape in order to detect the majority of MPs that are trapped around the conducting structure. The GMR sensing elements are connected in a Wheatstone bridge circuit topology for optimum noise suppression. Full fabrication details of the micro-chip, characterization of the GMRsensors, and experimental results with MPs are presented in this paper. Experimental results showed that the micro-chip can detect MPs from low concentration samples after they were guided toward the GMRsensors by applying current to the conducting ring structure.

  1. Application of single-chip microcomputer in radiation detection

    International Nuclear Information System (INIS)

    Zhang Songshou

    1993-01-01

    The single-chip microcomputer has some advantages in many aspects for example the strong function, the small volume, the low-power, firmed and reliable. It is used widely in the control of industry, instrument, communication and machine, etc.. The paper introduces that the single-chip microcomputer is used in radiation detection, mostly including the use of control, linear, compensation, calculation, prefabricated change, improving precision and training

  2. Single-particle cryo-electron microscopy of Rift Valley fever virus

    OpenAIRE

    Sherman, Michael B.; Freiberg, Alexander N.; Holbrook, Michael R.; Watowich, Stanley J.

    2009-01-01

    Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human veterinary pathogen causing acute hepatitis in ruminants and has the potential to Single-particle cryo-EM reconstruction of RVFV MP-12 hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on...

  3. Superconducting nano-strip particle detectors

    International Nuclear Information System (INIS)

    Cristiano, R; Ejrnaes, M; Casaburi, A; Zen, N; Ohkubo, M

    2015-01-01

    We review progress in the development and applications of superconducting nano-strip particle detectors. Particle detectors based on superconducting nano-strips stem from the parent devices developed for single photon detection (SSPD) and share with them ultra-fast response times (sub-nanosecond) and the ability to operate at a relatively high temperature (2–5 K) compared with other cryogenic detectors. SSPDs have been used in the detection of electrons, neutral and charged ions, and biological macromolecules; nevertheless, the development of superconducting nano-strip particle detectors has mainly been driven by their use in time-of-flight mass spectrometers (TOF-MSs) where the goal of 100% efficiency at large mass values can be achieved. Special emphasis will be given to this case, reporting on the great progress which has been achieved and which permits us to overcome the limitations of existing mass spectrometers represented by low detection efficiency at large masses and charge/mass ambiguity. Furthermore, such progress could represent a breakthrough in the field. In this review article we will introduce the device concept and detection principle, stressing the peculiarities of the nano-strip particle detector as well as its similarities with photon detectors. The development of parallel strip configuration is introduced and extensively discussed, since it has contributed to the significant progress of TOF-MS applications. (paper)

  4. Novel approaches for single molecule activation and detection

    CERN Document Server

    Benfenati, Fabio; Torre, Vincent

    2014-01-01

    How can we obtain tools able to process and exchange information at the molecular scale In order to do this, it is necessary to activate and detect single molecules under controlled conditions. This book focuses on the generation of biologically-inspired molecular devices. These devices are based on the developments of new photonic tools able to activate and stimulate single molecule machines. Additionally, new light sensitive molecules can be selectively activated by photonic tools. These technological innovations will provide a way to control activation of single light-sensitive molecules, a

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

    International Nuclear Information System (INIS)

    Bernassau, A. L.; Al-Rawhani, M.; Beeley, J.; Cumming, D. R. S.

    2013-01-01

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

  6. Phase-coexistence simulations of fluid mixtures by the Markov Chain Monte Carlo method using single-particle models

    KAUST Repository

    Li, Jun; Calo, Victor M.

    2013-01-01

    models although its deviation in the liquid phase is greater. Since the single-particle model reduces the particle number and avoids the time-consuming Ewald summation used to evaluate Coulomb interactions, the proposed model improves the computational

  7. Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

    Science.gov (United States)

    Payne, A.; Ambal, K.; Boehme, C.; Williams, C. C.

    2015-05-01

    A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single-electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy system noise. The results show that the approach could provide single-spin measurement of electrically isolated qubit states with atomic spatial resolution at room temperature.

  8. Online differentiation of mineral phase in aerosol particles by ion formation mechanism using a LAAP-TOF single-particle mass spectrometer

    Directory of Open Access Journals (Sweden)

    N. A. Marsden

    2018-01-01

    Full Text Available Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase. Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI followed by time-of-flight mass spectrometry (TOF-MS. Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.In this study, we introduce a novel technique that enables the differentiation of mineral phase in silicate mineral particles by ion formation mechanism measured from subtle changes in ion arrival times at the TOF-MS detector. Using a combination of peak area and peak centroid measurements, we show that the arrangement of the interstitial alkali metals in the crystal structure, an important property in silicate mineralogy, influences the ion arrival times of elemental and molecular ion species in the negative ion mass spectra. A classification scheme is presented that allowed for the differentiation of illite–smectite, kaolinite and feldspar minerals on a single-particle basis. Online analysis of mineral dust aerosol generated from clay mineral standards produced mineral fractions that are in agreement with bulk

  9. Single-particle coherent diffractive imaging with a soft x-ray free electron laser: towards soot aerosol morphology

    Science.gov (United States)

    Bogan, Michael J.; Starodub, Dmitri; Hampton, Christina Y.; Sierra, Raymond G.

    2010-10-01

    The first of its kind, the Free electron LASer facility in Hamburg, FLASH, produces soft x-ray pulses with unprecedented properties (10 fs, 6.8-47 nm, 1012 photons per pulse, 20 µm diameter). One of the seminal FLASH experiments is single-pulse coherent x-ray diffractive imaging (CXDI). CXDI utilizes the ultrafast and ultrabright pulses to overcome resolution limitations in x-ray microscopy imposed by x-ray-induced damage to the sample by 'diffracting before destroying' the sample on sub-picosecond timescales. For many lensless imaging algorithms used for CXDI it is convenient when the data satisfy an oversampling constraint that requires the sample to be an isolated object, i.e. an individual 'free-standing' portion of disordered matter delivered to the centre of the x-ray focus. By definition, this type of matter is an aerosol. This paper will describe the role of aerosol science methodologies used for the validation of the 'diffract before destroy' hypothesis and the execution of the first single-particle CXDI experiments being developed for biological imaging. FLASH CXDI now enables the highest resolution imaging of single micron-sized or smaller airborne particulate matter to date while preserving the native substrate-free state of the aerosol. Electron microscopy offers higher resolution for single-particle analysis but the aerosol must be captured on a substrate, potentially modifying the particle morphology. Thus, FLASH is poised to contribute significant advancements in our knowledge of aerosol morphology and dynamics. As an example, we simulate CXDI of combustion particle (soot) morphology and introduce the concept of extracting radius of gyration of fractal aggregates from single-pulse x-ray diffraction data. Future upgrades to FLASH will enable higher spatially and temporally resolved single-particle aerosol dynamics studies, filling a critical technological need in aerosol science and nanotechnology. Many of the methodologies described for FLASH will

  10. Single-particle coherent diffractive imaging with a soft x-ray free electron laser: towards soot aerosol morphology

    International Nuclear Information System (INIS)

    Bogan, Michael J; Starodub, Dmitri; Hampton, Christina Y; Sierra, Raymond G

    2010-01-01

    The first of its kind, the Free electron LASer facility in Hamburg, FLASH, produces soft x-ray pulses with unprecedented properties (10 fs, 6.8-47 nm, 10 12 photons per pulse, 20 μm diameter). One of the seminal FLASH experiments is single-pulse coherent x-ray diffractive imaging (CXDI). CXDI utilizes the ultrafast and ultrabright pulses to overcome resolution limitations in x-ray microscopy imposed by x-ray-induced damage to the sample by 'diffracting before destroying' the sample on sub-picosecond timescales. For many lensless imaging algorithms used for CXDI it is convenient when the data satisfy an oversampling constraint that requires the sample to be an isolated object, i.e. an individual 'free-standing' portion of disordered matter delivered to the centre of the x-ray focus. By definition, this type of matter is an aerosol. This paper will describe the role of aerosol science methodologies used for the validation of the 'diffract before destroy' hypothesis and the execution of the first single-particle CXDI experiments being developed for biological imaging. FLASH CXDI now enables the highest resolution imaging of single micron-sized or smaller airborne particulate matter to date while preserving the native substrate-free state of the aerosol. Electron microscopy offers higher resolution for single-particle analysis but the aerosol must be captured on a substrate, potentially modifying the particle morphology. Thus, FLASH is poised to contribute significant advancements in our knowledge of aerosol morphology and dynamics. As an example, we simulate CXDI of combustion particle (soot) morphology and introduce the concept of extracting radius of gyration of fractal aggregates from single-pulse x-ray diffraction data. Future upgrades to FLASH will enable higher spatially and temporally resolved single-particle aerosol dynamics studies, filling a critical technological need in aerosol science and nanotechnology. Many of the methodologies described for FLASH will

  11. Effective particle magnetic moment of multi-core particles

    Energy Technology Data Exchange (ETDEWEB)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

    2015-04-15

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  12. Effective particle magnetic moment of multi-core particles

    International Nuclear Information System (INIS)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-01-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm

  13. Effective particle magnetic moment of multi-core particles

    Science.gov (United States)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; van IJzendoorn, Leo J.; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-04-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems - BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm - and one single-core particle system - SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  14. Modified Single Photo-diode (MSPD) Detection Technique for SAC-OCDMA System

    Science.gov (United States)

    Abdulqader, Sarah G.; Fadhil, Hilal A.; Aljunid, S. A.

    2015-03-01

    In this paper, a new detection technique called modified single photo-diode (MSPD) detection for SAC-OCDMA system is proposed. The proposed system based on the single photo-diode (SPD) detection technique. The new detection technique is proposed to overcome the limitation of phase-induced intensity noise (PIIN) in SPD detection technique. However, the proposed detection is based on an optical hard limiter (OHL) followed by a SPD and a low-pass filter (LPF) in order to suppress the phase intensity noise (PIIN) at the receiver side. The results show that the MSPD detection based on OHL has a good performance even when the transmission distance is long, which is different from the case of SPD detection technique. Therefore, the MSPD detection technique is shown to be effective to improve the bit error rate (BER<10-9) and to suppress the noise in the practical optical fiber network.

  15. Self-consistent neutral point current and fields from single particle dynamics

    International Nuclear Information System (INIS)

    Martin, R.F. Jr.

    1988-01-01

    In order to begin to build a global model of the magnetotail-auroral region interaction, it is of interest to understand the role of neutral points as potential centers of particle energization in the tail. In this paper, the single particle current is calculated near a magnetic neutral point with magnetotail properties. This is balanced with the Ampere's law current producing the magnetic field to obtain the self-consistent electric field for the problem. Also calculated is the current-electric field relationship and, in the regime where this relation is linear, an effective conductivity. Results for these macroscopic quantities are surprisingly similar to the values calculated for a constant normal field current sheet geometry. Application to magnetotail modeling is discussed. 11 references

  16. Detection of charged particles in thick hydrogenated amorphous silicon layers

    International Nuclear Information System (INIS)

    Fujieda, I.; Cho, G.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Ward, W.; Street, R.A.

    1988-03-01

    We show our results in detecting particles of various linear energy transfer, including minimum ionizing electrons from a Sr-90 source with 5 to 12 micron thick n-i-p and p-i-n diodes. We measured W ( average energy to produce one electron-hole pair) using 17keV filtered xray pulses with a result W = 6.0 /+-/ 0.2eV. This is consistent with the expected value for a semiconductor with band gap of 1.7 to 1.9eV. With heavily ionizing particles such as 6 MeV alphas and 1 to 2 MeV protons, there was some loss of signal due to recombination in the particle track. The minimum ionizing electrons showed no sign of recombination. Applications to pixel and strip detectors for physics experiments and medical imaging will be discussed. 7 refs., 8 figs

  17. Spin resonance strength calculation through single particle tracking for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The strengths of spin resonances for the polarized-proton operation in the Relativistic Heavy Ion Collider are currently calculated with the code DEPOL, which numerically integrates through the ring based on an analytical approximate formula. In this article, we test a new way to calculate the spin resonance strengths by performing Fourier transformation to the actual transverse magnetic fields seen by a single particle traveling through the ring. Comparison of calculated spin resonance strengths is made between this method and DEPOL.

  18. Pre-asymptotic behavior of single-particle overlap integrals of non-Borromean two-neutron halos

    International Nuclear Information System (INIS)

    Timofeyuk, N.K.; Tostevin, J.A.; Blokhintsev, L.D.

    2003-01-01

    For non-Borromean two-neutron halo nuclei, modifications to the behavior of single-particle overlap integrals will arise due to the correlations of the two interacting nucleons in the halo. An additional contribution to the overlap integral can be obtained using the Feynman diagram approach. This additional term is modeled using a simple local potential model. We show that these modifications may play a role in detailed interpretations of experimental results from single-nucleon knockout, transfer, and other reactions that probe the single-nucleon overlap functions

  19. Study of the phase transformation of single particles of Ga2O3 by UV-Raman spectroscopy and high-resolution TEM.

    Science.gov (United States)

    Wang, Xiang; Xu, Qian; Fan, Fengtao; Wang, Xiuli; Li, Mingrun; Feng, Zhaochi; Li, Can

    2013-09-01

    By taking advantage of UV-Raman spectroscopy and high-resolution TEM (HRTEM), combined with the focused ion beam (FIB) technique, the transformation from GaOOH into α-Ga2O3 and then into β-Ga2O3 was followed. We found that the stepwise transformations took place from the surface region before developing into the bulk of single particles without particle agglomeration and growth. During the transformation from GaOOH into α-Ga2O3, the elimination of water vapor through the dehydroxylation of GaOOH resulted in the formation of micropores in the single particles, whilst maintaining their particle size. For the phase transformation from α-Ga2O3 into β-Ga2O3, the nucleation of β-Ga2O3 was found to occur at the surface defects and this process could be retarded by occupying these defects with a small amount of La2O3. By finely controlling the process of the phase transformation, the β-Ga2O3 domains gradually developed from the surface into the bulk of the single particles without particle agglomeration. Therefore, the surface structure of the α-Ga2O3 single particles can be easily tuned and a particle with an α@β core-shell phase structure has been obtained. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Photoluminescence detection of alpha particle using DAM-ADC nuclear detector

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, Ayman M., E-mail: aymanabdalla62@hotmail.com [Department of Physics, College of Science and Arts, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box: 1988, Najran 11001 (Saudi Arabia); Harraz, Farid A., E-mail: fharraz68@yahoo.com [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box: 1988, Najran 11001 (Saudi Arabia); Nanostructured Materials and Nanotechnology Division, Central Metallurgical Research and Development Institute (CMRDI), P.O. Box: 87 Helwan, Cairo 11421 (Egypt); Ali, Atif M. [Department of Physics, Faculty of Science, King Khalid University, Abha (Saudi Arabia); Al-Sayari, S.A. [Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box: 1988, Najran 11001 (Saudi Arabia); College of Science and Arts-Sharoura, Najran University (Saudi Arabia); Al-Hajry, A. [Department of Physics, College of Science and Arts, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box: 1988, Najran 11001 (Saudi Arabia)

    2016-09-11

    The photoluminescence (PL) and UV–vis spectral analysis of DAM-ADC (diallyl maleate: DAM, polyallyl diglycol carbonate: ADC) nuclear detector are demonstrated for the first time. The DAM-ADC surfaces were exposed to thin {sup 241}Am disk source that emits alpha particles with activity 333 kBq. It is found that the track density of the irradiated samples remarkably influences the PL characteristics of the DAM-ADC detector. The spectral peak heights and the integrated intensities under the peaks exhibit linear correlations with correlation coefficient R{sup 2}=0.9636 and 0.9806, respectively for different alpha particle fluences ranging from 8.16–40.82×10{sup 7} particles/cm{sup 2}. Additionally, a correlation coefficient R{sup 2}=0.9734 was achieved for the UV–vis spectral analysis. The linear fitting functions, along with the corresponding fitting parameters were evaluated in each case. Both the PL and the UV–vis data of the irradiated DAM-ADC samples showed considerable spectral differences, and hence they would be used to offer sensitive approaches for alpha particle detection.

  1. A new microcavity design for single molecule detection

    International Nuclear Information System (INIS)

    Steiner, M.; Schleifenbaum, F.; Stupperich, C.; Failla, A.V.; Hartschuh, A.; Meixner, A.J.

    2006-01-01

    We present a new microcavity design which allows for efficient detection of single molecules by measuring the molecular fluorescence emission coupled into a resonant cavity mode. The Fabry-Perot-type microresonator consists of two silver mirrors separated by a thin polymer film doped with dye molecules in ultralow concenctration. By slightly tilting one of the mirrors different cavity lengths can be selected within the same sample. Locally, on a μm scale, the microcavity still acts as a planar Fabry-Perot resonator. Using scanning confocal fluorescence microscopy, single emitters on resonance with a single mode of the microresonator can be spatially addressed. Our microcavity is demonstrated to be well-suited for investigating the coupling mechanism between single quantum emitters and single modes of the electromagnetic field. The microcavity layout could be integrated in a lab-on-a-microchip design for ultrasensitive microfluidic analytics and can be considered as an important improvement for single photon sources based on single molecules operating at room temperature

  2. Measurements of meteor smoke particles during the ECOMA-2006 campaign: 1. Particle detection by active photoionization

    Science.gov (United States)

    Rapp, Markus; Strelnikova, Irina

    2009-03-01

    We present a new design of an in situ detector for the study of meteor smoke particles (MSPs) in the middle atmosphere. This detector combines a classical Faraday cup with a xenon-flashlamp for the active photoionization/photodetachment of MSPs and the subsequent detection of corresponding photoelectrons. This instrument was successfully launched in September 2006 from the Andøya Rocket Range in Northern Norway. A comparison of photocurrents measured during this rocket flight and measurements performed in the laboratory proves that observed signatures are truly due to photoelectrons. In addition, the observed altitude cut-off at 60 km (i.e., no signals were observed below this altitude) is fully understood in terms of the mean free path of the photoelectrons in the ambient atmosphere. This interpretation is also proven by a corresponding laboratory experiment. Consideration of all conceivable species which can be ionized by the photons of the xenon-flashlamp demonstrates that only MSPs can quantitatively explain the measured currents below an altitude of 90 km. Above this altitude, measured photocurrents are most likely due to photoionization of nitric oxide. In conclusion, our results demonstrate that the active photoionization and subsequent detection of photoelectrons provides a promising new tool for the study of MSPs in the middle atmosphere. Importantly, this new technique does not rely on the a priori charge of the particles, neither is the accessible particle size range severely limited by aerodynamical effects. Based on the analysis described in this study, the geophysical interpretation of our measurements is presented in the companion paper by Strelnikova, I., et al. [2008. Measurements of meteor smoke particles during the ECOMA-2006 campaign: 2. results. Journal of Atmospheric and Solar-Terrestrial Physics, this issue, doi:10.1016/j.jastp.2008.07.011].

  3. Redundancy-free single-particle equation-of-motion method for nuclei. Pt. 1

    International Nuclear Information System (INIS)

    Rolnick, P.; Goswami, A.; Oregon Univ., Eugene

    1986-01-01

    The problem of coupling an odd nucleon to the collective states of an even core is considered in the intermediate-coupling limit. It is now well known that such intermediate-coupling calculations in spherical open-shell nuclei necessitate the inclusion of ground-state correlation or backward coupling which gives rise to an overcomplete basic set of states for the diagonalization of the hamiltonian. In a recent letter, we have derived a technique to free the single-particle equation-of-motion method of redundancy. Here we shall apply this redundancy-free equation-of-motion method to intermediate-coupling calculations in two regions of near-spherical odd-mass nuclei where forward coupling alone has not been successful. It is shown that qualitative effects of backward coupling previously reported are not spurious effects of double counting, although they are significantly modified by the removal of redundancy. We also discuss what further modifications of the theory will be needed in order to treat the dynamical interplay of collective and single-particle modes in nuclei self-consistently on the same footing. (orig.)

  4. Hierarchical Ag mesostructures for single particle SERS substrate

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Minwei, E-mail: xuminwei@xjtu.edu.cn; Zhang, Yin

    2017-01-30

    Highlights: • Hierarchical Ag mesostructures with the size of 250, 360 and 500 nm are synthesized via a seed-mediated approach. • The Ag mesostructures present the tailorable size and highly roughened surfaces. • The average enhancement factors for individual Ag mesostructures were estimated to be as high as 10{sup 6}. - Abstract: Hierarchical Ag mesostructures with highly rough surface morphology have been synthesized at room temperature through a simple seed-mediated approach. Electron microscopy characterizations indicate that the obtained Ag mesostructures exhibit a textured surface morphology with the flower-like architecture. Moreover, the particle size can be tailored easily in the range of 250–500 nm. For the growth process of the hierarchical Ag mesostructures, it is believed that the self-assembly mechanism is more reasonable rather than the epitaxial overgrowth of Ag seed. The oriented attachment of nanoparticles is revealed during the formation of Ag mesostructures. Single particle surface enhanced Raman spectra (sp-SERS) of crystal violet adsorbed on the hierarchical Ag mesostructures were measured. Results reveal that the hierarchical Ag mesostructures can be highly sensitive sp-SERS substrates with good reproducibility. The average enhancement factors for individual Ag mesostructures are estimated to be about 10{sup 6}.

  5. Orbital single particle tracking on a commercial confocal microscope using piezoelectric stage feedback

    International Nuclear Information System (INIS)

    Lanzanò, L; Gratton, E

    2014-01-01

    Single Particle Tracking (SPT) is a technique used to locate fluorescent particles with nanometer precision. In the orbital tracking method the position of a particle is obtained analyzing the distribution of intensity along a circular orbit scanned around the particle. In combination with an active feedback this method allows tracking of particles in 2D and 3D with millisecond temporal resolution. Here we describe a SPT setup based on a feedback approach implemented with minimal modification of a commercially available confocal laser scanning microscope, the Zeiss LSM 510, in combination with an external piezoelectric stage scanner. The commercial microscope offers the advantage of a user-friendly software interface and pre-calibrated hardware components. The use of an external piezo-scanner allows the addition of feedback into the system but also represents a limitation in terms of its mechanical response. We describe in detail this implementation of the orbital tracking method and discuss advantages and limitations. As an example of application to live cell experiments we perform the 3D tracking of acidic vesicles in live polarized epithelial cells. (paper)

  6. Neutron densities and the single particle structure of several even-even nuclei from 40Ca to 208Pb

    International Nuclear Information System (INIS)

    Ray, L.; Hodgson, P.E.

    1979-01-01

    Previously developed techniques which sum the squares of proton single particle wave functions to obtain nuclear charge densities are applied to the study of neutron distributions in /sup 40,48/Ca, /sup 58,64/Ni, /sup 116,124/Sn, and 208 Pb by comparing to those neutron densities deduced from 800 MeV proton elastic scattering data. The proton and neutron single particle wave functions are derived from a one-body, nonlocal Woods-Saxon binding potential whose parameters are adjusted to give the experimental single particle energies. Empirical spectroscopic factors determine the appropriate occupation probabilities for the single particle levels near the Fermi surface. Proper attention is given to nonorthogonality problems and to the removal of the spurious center-of-mass motion. These semiphenomenological neutron densities are compared to the predictions of the density matrix expansion variant of Hartree-Fock theory and to densities which are empirically deduced from recent 800 MeV polarized proton elastic scattering data. These ''experimental'' neutron distributions are obtained from approximate second order Kerman, McManus, and Thaler optical potential analyses using essentially ''model independent'' neutron densities. Qualitatively good agreement is obtained between the semiphenomenological neutron densities computed here, the density matrix expansion predictions, and the empirical results

  7. Detection alpha particles and Cf-252 fission fragments with track solid detectors and with surface barrier detectors: efficiency determination

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.R.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    The technique of particle detection by solid track detectors, types of developing and analysis of results are presented. Efficiency measurements of alpha particle detection with Makrofol e and surface barrier detector are made. Detection of Cf-252 fission fragments is shown. (L.C.)

  8. Beta particle detection efficiency of the radiation sensor made from a mixture of polyaniline and titanium oxide

    International Nuclear Information System (INIS)

    Tamura, M.; Miyata, H.; Katsumata, M.; Matsuda, K.; Ueno, T.; Ito, D.; Suzuki, T.

    2016-01-01

    We developed a new real-time radiation sensor using an organic semiconductor and measured its β-particle detection sensitivity. This sensor is fabricated by simply combining a p-type semiconductor, polyaniline (Pani), with an n-type semiconductor, TiO_2, and processing the compound. Since Pani and TiO_2 are both inexpensive materials, the sensor can be fabricated at a lower cost than inorganic semiconductor sensors. The signal of each fabricated sensor was measured by a charge sensitive ADC for the irradiation of β-particles. The response signal data of the ADC for each irradiation was measured to calculate the detection efficiency of the detector. The maximum detection efficiency measured as β-particle sensitivity of the sensor was 1%. This β-particle sensitivity is higher than that reported of Pani sensors in the past.

  9. 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

  10. Wigglers and single-particle dynamics in the NLC damping rings

    International Nuclear Information System (INIS)

    Venturini, Marco; Wolski, Andrzej; Dragt, Alex

    2003-01-01

    Wiggler insertions are expected to occupy a significant portion of the lattice of the Next Linear Collider (NLC) Main Damping Rings (MDR) and have a noticeable impact on the single-particle beam dynamics. Starting from a realistic 3D representation of the magnetic fields we calculate the transfer maps for the wigglers, accounting for linear and nonlinear effects, and we study the beam dynamics with particular attention paid to the Dynamic Aperture(DA). A DA reduction is observed but appears to remain within acceptable limits

  11. Associated-particle sealed-tube neutron probe: Detection of explosives, contraband, and nuclear materials

    International Nuclear Information System (INIS)

    Rhodes, E.; Dickerman, C.E.

    1996-01-01

    Continued research and development of the APSTNG shows the potential for practical field use of this technology for detection of explosives, contraband, and nuclear materials. The APSTNG (associated-particle sealed-tube generator) inspects the item to be examined using penetrating 14-MeV neutrons generated by the deuterium-tritium reaction inside a compact accelerator tube. An alpha detector built into the sealed tube detects the alpha-particle associated with each neutron emitted in a cone encompassing the volume to be inspected. Penetrating high-energy gamma-rays from the resulting neutron reactions identify specific nuclides inside the volume. Flight-times determined from the detection times of gamma-rays and alpha-particles separate the prompt and delayed gamma-ray spectra and allow a coarse 3-D image to be obtained of nuclides identified in the prompt spectrum. The generator and detectors can be on the same side of the inspected object, on opposite sides, or with intermediate orientations. Thus, spaces behind walls and other confined regions can be inspected. Signals from container walls can be discriminated against using the flight-time technique. No collimators or shielding are required, the neutron generator is relatively small, and commercial-grade electronics are employed. The use of 14-MeV neutrons yields a much higher cross-section for detecting nitrogen than that for systems based on thermal-neutron reactions alone, and the broad range of elements with significant 14-MeV neutron cross-sections extends explosives detection to other elements including low-nitrogen compounds, and allows detection of many other substances. Proof-of-concept experiments have been successfully performed for conventional explosives, chemical warfare agents, cocaine, and fissionable materials

  12. Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires

    International Nuclear Information System (INIS)

    Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Goltsman, Gregory N.; Korneev, Alexander; Pernice, Wolfram H. P.

    2015-01-01

    We investigate single- and multi-photon detection regimes of superconducting nanowire detectors embedded in silicon nitride nanophotonic circuits. At near-infrared wavelengths, simultaneous detection of up to three photons is observed for 120 nm wide nanowires biased far from the critical current, while narrow nanowires below 100 nm provide efficient single photon detection. A theoretical model is proposed to determine the different detection regimes and to calculate the corresponding internal quantum efficiency. The predicted saturation of the internal quantum efficiency in the single photon regime agrees well with plateau behavior observed at high bias currents

  13. Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Simone; Kahl, Oliver [Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe 76132 (Germany); Kovalyuk, Vadim [Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe 76132 (Germany); Department of Physics, Moscow State Pedagogical University, Moscow 119992 (Russian Federation); Goltsman, Gregory N. [Department of Physics, Moscow State Pedagogical University, Moscow 119992 (Russian Federation); National Research University Higher School of Economics, 20 Myasnitskaya Ulitsa, Moscow 101000 (Russian Federation); Korneev, Alexander [Department of Physics, Moscow State Pedagogical University, Moscow 119992 (Russian Federation); Moscow Institute of Physics and Technology (State University), Moscow 141700 (Russian Federation); Pernice, Wolfram H. P., E-mail: wolfram.pernice@kit.edu [Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe 76132 (Germany); Department of Physics, University of Münster, 48149 Münster (Germany)

    2015-04-13

    We investigate single- and multi-photon detection regimes of superconducting nanowire detectors embedded in silicon nitride nanophotonic circuits. At near-infrared wavelengths, simultaneous detection of up to three photons is observed for 120 nm wide nanowires biased far from the critical current, while narrow nanowires below 100 nm provide efficient single photon detection. A theoretical model is proposed to determine the different detection regimes and to calculate the corresponding internal quantum efficiency. The predicted saturation of the internal quantum efficiency in the single photon regime agrees well with plateau behavior observed at high bias currents.

  14. Practical Considerations for Detection and Characterization of Sub-Micron Particles in Protein Solutions by Nanoparticle Tracking Analysis.

    Science.gov (United States)

    Gruia, Flaviu; Parupudi, Arun; Polozova, Alla

    2015-01-01

    Nanoparticle Tracking Analysis (NTA) is an emerging analytical technique developed for detection, sizing, and counting of sub-micron particles in liquid media. Its feasibility for use in biopharmaceutical development was evaluated with particle standards and recombinant protein solutions. Measurements of aqueous suspensions of NIST-traceable polystyrene particle standards showed accurate particle concentration detection between 2 × 10(7) and 5 × 10(9) particles/mL. Sizing was accurate for particle standards up to 200 nm. Smaller than nominal value sizes were detected by NTA for the 300-900 nm particles. Measurements of protein solutions showed that NTA performance is solution-specific. Reduced sensitivity, especially in opalescent solutions, was observed. Measurements in such solutions may require sample dilution; however, common sample manipulations, such as dilution and filtration, may result in particle formation. Dilution and filtration case studies are presented to further illustrate such behavior. To benchmark general performance, NTA was compared against asymmetric flow field flow fractionation coupled with multi-angle light scattering (aF4-MALS) and dynamic light scattering, which are other techniques for sub-micron particles. Data shows that all three methods have limitations and may not work equally well under certain conditions. Nevertheless, the ability of NTA to directly detect and count sub-micron particles is a feature not matched by aF4-MALS or dynamic light scattering. Thorough characterization of particulate matter present in protein therapeutics is limited by the lack of analytical methods for particles in the sub-micron size range. Emerging techniques are being developed to bridge this analytical gap. In this study, Nanoparticle Tracking Analysis is evaluated as a potential tool for biologics development. Our results indicate that method performance is molecule-specific and may not work as well under all solution conditions, especially when

  15. Development and Characterization of Embedded Sensory Particles Using Multi-Scale 3D Digital Image Correlation

    Science.gov (United States)

    Cornell, Stephen R.; Leser, William P.; Hochhalter, Jacob D.; Newman, John A.; Hartl, Darren J.

    2014-01-01

    A method for detecting fatigue cracks has been explored at NASA Langley Research Center. Microscopic NiTi shape memory alloy (sensory) particles were embedded in a 7050 aluminum alloy matrix to detect the presence of fatigue cracks. Cracks exhibit an elevated stress field near their tip inducing a martensitic phase transformation in nearby sensory particles. Detectable levels of acoustic energy are emitted upon particle phase transformation such that the existence and location of fatigue cracks can be detected. To test this concept, a fatigue crack was grown in a mode-I single-edge notch fatigue crack growth specimen containing sensory particles. As the crack approached the sensory particles, measurements of particle strain, matrix-particle debonding, and phase transformation behavior of the sensory particles were performed. Full-field deformation measurements were performed using a novel multi-scale optical 3D digital image correlation (DIC) system. This information will be used in a finite element-based study to determine optimal sensory material behavior and density.

  16. Evolution of Single Particle and Collective properties in the Neutron-Rich Mg Isotopes

    CERN Multimedia

    Reiter, P; Wiens, A; Fitting, J; Lauer, M; Van duppen, P L E; Finke, F

    2002-01-01

    We propose to study the single particle and collective properties of the neutron-rich Mg isotopes in transfer reactions and Coulomb excitation using REX-ISOLDE and MINIBALL. From the Coulomb excitation measurement precise and largely model independent B( E2 ; 0$^{+}_{g.s.}\\rightarrow$ 2$^{+}_{1}$ ) will be determined for the even-even isotopes. For the odd isotopes the distribution of the E2 strength over a few low-lying states will be measured. The sign of the M1/E2 mixing ratio, extracted from angular distributions, is characteristic of the sign of the deformation, as is the resulting level scheme. The neutron-pickup channel in the transfer reactions will allow for a determination of the single particle properties (spin, parity, spectroscopic factors) of these nuclei. This information will give new insights in changes of nuclear structure in the vicinity of the island of deformation around $^{32}$Mg. A total of 24 shifts of REX beam time is requested.

  17. Direct detection of the optical field beyond single polarization mode.

    Science.gov (United States)

    Che, Di; Sun, Chuanbowen; Shieh, William

    2018-02-05

    Direct detection is traditionally regarded as a detection method that recovers only the optical intensity. Compared with coherent detection, it owns a natural advantage-the simplicity-but lacks a crucial capability of field recovery that enables not only the multi-dimensional modulation, but also the digital compensation of the fiber impairments linear with the optical field. Full-field detection is crucial to increase the capacity-distance product of optical transmission systems. A variety of methods have been investigated to directly detect the optical field of the single polarization mode, which normally sends a carrier traveling with the signal for self-coherent detection. The crux, however, is that any optical transmission medium supports at least two propagating modes (e.g. single mode fiber supports two polarization modes), and until now there is no direct detection that can recover the complete set of optical fields beyond one polarization, due to the well-known carrier fading issue after mode demultiplexing induced by the random mode coupling. To avoid the fading, direct detection receivers should recover the signal in an intensity space isomorphic to the optical field without loss of any degrees of freedom, and a bridge should be built between the field and its isomorphic space for the multi-mode field recovery. Based on this thinking, we propose, for the first time, the direct detection of dual polarization modes by a novel receiver concept, the Stokes-space field receiver (SSFR) and its extension, the generalized SSFR for multiple spatial modes. The idea is verified by a dual-polarization field recovery of a polarization-multiplexed complex signal over an 80-km single mode fiber transmission. SSFR can be applied to a much wider range of fields beyond optical communications such as coherent sensing and imaging, where simple field recovery without an extra local laser is desired for enhanced system performance.

  18. Competition between collective and single particle excitations in nuclear structure description

    International Nuclear Information System (INIS)

    Petrovici, A.N.

    1983-01-01

    The microscopic description of the quadrupole collective dynamics in even krypton isotopes is presented. A microscopic calculation of Bohr's collective Hamiltonian is used to describe the collective motion in 76 Kr. A single-particle basis calculated in a deformed Woods-Saxon potential leads to the potential energy surface obtained by the Strutinsky renormalization procedure, and to the inertial functions determined in the cranking model approximation. The collective Schroedinger equation is solved numerically to analyse the low-energy, even parity states in 76 Kr. A good agreement between experiment and theory is obtained without specifically adjusting any parameter in the model for this nucleus. Some results regarding statical and dynamical characteristics of sup(74,78,80)Kr isotopes are also presented. The asymmetric rotor model with admixture of two quasiparticles is used to describe the sup(66,68,70)Ge and the sup(64,66)Zn isotopes. The interplay of collective and single particle motions is further investigated by magnetic moment measurements using the method of integral angular correlations perturbed by recoil into gas. The results involve g-factor measurements for 166 Ho, 68 Ge, 64 Zn, 66 Zn and 68 Ga nuclei. Finally, a discussion of further possible improvements and more general developments of the problems under investigation is given. (author)

  19. Experimental study of single-phase pressure drops in coarse particle beds

    Energy Technology Data Exchange (ETDEWEB)

    Clavier, R., E-mail: remi.clavier@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Chikhi, N., E-mail: nourdine.chikhi@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Fichot, F., E-mail: florian.fichot@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Quintard, M., E-mail: Michel.Quintard@imft.fr [Université de Toulouse, Allée Camille Soula, F-31400 Toulouse (France); INPT, UPS, Allée Camille Soula, F-31400 Toulouse (France); IMFT (Institut de Mécanique des Fluides de Toulouse), Allée Camille Soula, F-31400 Toulouse (France); CNRS, F-31400 Toulouse (France)

    2017-02-15

    Motivated by uncertainty reduction in nuclear debris beds coolability, experiments have been conducted on the CALIDE facility in order to investigate single-phase pressure losses in representative debris beds, i.e., high sphericity (>80%) particle beds with small size dispersion (from 1 mm to 10 mm), for which no validated model exists. In this paper, experimental results are presented and analyzed in order to identify a simple correlation for single-phase flow pressure losses generated in this kind of porous media in reflooding flowing conditions, which cover Darcy to weakly turbulent regimes. In the literature, it has been observed that their behavior can be accurately described by a Darcy–Forchheimer law, involving the sum of a linear term and a quadratic non-linear deviation, with respect to the filtration velocity. Expressions for the coefficients of the linear and quadratic terms are determined by assessing the possibility to evaluate equivalent diameters, i.e., characteristic lengths allowing correct predictions of the linear and quadratic terms by the Ergun equation. It has been observed that the Sauter diameter of particles allows a very precise prediction of the linear term, while the quadratic term can be predicted using the product of the Sauter diameter and a sphericity coefficient as an equivalent diameter.

  20. Detection of alpha particles and Cf-252 fission fragments with solid track detectors and surface barrier detector. Efficiency calculation

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.E.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    A technique for particle detection by using track solid detector and also types of revealing and result analysis are presented concerned to Cf-252 fission fragments detection. Measurements of alpha particles detection efficiency using Makrofol E and surface barrier detector are performed. (L.C.J.A.)

  1. Particle-bubble aggregate stability on static bubble generated by single nozzle on flotation process

    Science.gov (United States)

    Warjito, Harinaldi, Setyantono, Manus; Siregar, Sahala D.

    2016-06-01

    There are three sub-processes on flotation. These processes are intervening liquid film into critical thickness, rupture of liquid film forming three phase contact line, and expansion three phase contact line forming aggregate stability. Aggregate stability factor contribute to determine flotation efficiency. Aggregate stability has some important factors such as reagent and particle geometry. This research focussed on to understand effect of particle geometry to aggregate stability. Experimental setup consists of 9 x 9 x26 cm flotation column made of glass, bubble generator, particle feeding system, and high speed video camera. Bubble generator made from single nozzle with 0.3 mm diameter attached to programmable syringe pump. Particle feeding system made of pipette. Particle used in this research is taken from open pit Grasberg in Timika, Papua. Particle has sub-angular geometry and its size varies from 38 to 300 µm. Bubble-particle interaction are recorded using high speed video camera. Recordings from high speed video camera analyzed using image processing software. Experiment result shows that aggregate particle-bubble and induction time depends on particle size. Small particle (38-106 µm) has long induction time and able to rupture liquid film and also forming three phase contact line. Big particle (150-300 µm) has short induction time, so it unable to attach with bubble easily. This phenomenon is caused by apparent gravity work on particle-bubble interaction. Apparent gravity worked during particle sliding on bubble surface experience increase and reached its maximum magnitude at bubble equator. After particle passed bubble equator, apparent gravity force experience decrease. In conclusion particle size from 38-300 µm can form stable aggregate if particle attached with bubble in certain condition.

  2. Effect of single-particle splitting in the exact wave function of the isovectorial pairing Hamiltonian

    International Nuclear Information System (INIS)

    Lerma H, S.

    2010-01-01

    The structure of the exact wave function of the isovectorial pairing Hamiltonian with nondegenerate single-particle levels is discussed. The way that the single-particle splittings break the quartet condensate solution found for N=Z nuclei in a single degenerate level is established. After a brief review of the exact solution, the structure of the wave function is analyzed and some particular cases are considered where a clear interpretation of the wave function emerges. An expression for the exact wave function in terms of the isospin triplet of pair creators is given. The ground-state wave function is analyzed as a function of pairing strength, for a system of four protons and four neutrons. For small and large values of the pairing strength a dominance of two-pair (quartets) scalar couplings is found, whereas for intermediate values enhancements of the nonscalar couplings are obtained. A correlation of these enhancements with the creation of Cooper-like pairs is observed.

  3. Nuclear charge and magnetization densities of single particle states

    International Nuclear Information System (INIS)

    Frois, B.

    1985-01-01

    High energy electron scattering data have recently determined the spatial distributions of nucleons in the center of nuclei with amazing accuracy. For the first time we have access to the structure of the nuclear interior throughout the periodic table. The spatial resolution achieved by high momentum transfer measurements is now sufficient to define clearly the present limits of nuclear theory. The experimental situation is briefly reviewed and the results interpreted in the framework of self-consistent field theory. The shapes of single particle distributions in the nuclear interior are found to be in surprisingly good agreement with the predictions of mean field theory. The effects of correlations are discussed. (orig.)

  4. Nuclear charge and magnetization densities of single particle states

    International Nuclear Information System (INIS)

    Frois, B.

    1985-05-01

    High energy electron scattering data have recently determined the spatial distributions of nucleons in the center of nuclei with amazing accuracy. For the first time we have access to the structure of the nuclear interior throughout the periodic table. The spatial resolution achieved by high momentum transfer measurements is now sufficient to define clearly the present limits of nuclear theory. The experimental situation is briefly reviewed and the results interpreted in the framework of self-consistent field theory. The shapes of single particle distributions in the nuclear interior are found to be in surprisingly good agreement with the predictions of mean field theory. The effects of correlations are discussed

  5. Feature-Based Analysis of Plasma-Based Particle Acceleration Data

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, Oliver [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geddes, Cameron G. R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Min [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cormier-Michel, Estelle [Tech-X Corp., Boulder, CO (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-02-01

    Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a novel approach for automatic detection and classification of particle beams and beam substructures due to temporal differences in the acceleration process, here called acceleration features. The automatic feature detection in combination with a novel visualization tool for fast, intuitive, query-based exploration of acceleration features enables an effective top-down data exploration process, starting from a high-level, feature-based view down to the level of individual particles. We describe the application of our analysis in practice to analyze simulations of single pulse and dual and triple colliding pulse accelerator designs, and to study the formation and evolution of particle beams, to compare substructures of a beam and to investigate transverse particle loss.

  6. Excitable particles in an optical torque wrench

    Science.gov (United States)

    Pedaci, Francesco; Huang, Zhuangxiong; van Oene, Maarten; Barland, Stephane; Dekker, Nynke H.

    2011-03-01

    The optical torque wrench is a laser trapping technique capable of applying and directly measuring torque on microscopic birefringent particles using spin momentum transfer, and has found application in the measurement of static torsional properties of biological molecules such as single DNAs. Motivated by the potential of the optical torque wrench to access the fast rotational dynamics of biological systems, a result of its all-optical manipulation and detection, we focus on the angular dynamics of the trapped birefringent particle, demonstrating its excitability in the vicinity of a critical point. This links the optical torque wrench to nonlinear dynamical systems such as neuronal and cardiovascular tissues, nonlinear optics and chemical reactions, all of which display an excitable binary (`all-or-none') response to input perturbations. On the basis of this dynamical feature, we devise and implement a conceptually new sensing technique capable of detecting single perturbation events with high signal-to-noise ratio and continuously adjustable sensitivity.

  7. Single photon detection in a waveguide-coupled Ge-on-Si lateral avalanche photodiode.

    Science.gov (United States)

    Martinez, Nicholas J D; Gehl, Michael; Derose, Christopher T; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

    2017-07-10

    We examine gated-Geiger mode operation of an integrated waveguide-coupled Ge-on-Si lateral avalanche photodiode (APD) and demonstrate single photon detection at low dark count for this mode of operation. Our integrated waveguide-coupled APD is fabricated using a selective epitaxial Ge-on-Si growth process resulting in a separate absorption and charge multiplication (SACM) design compatible with our silicon photonics platform. Single photon detection efficiency and dark count rate is measured as a function of temperature in order to understand and optimize performance characteristics in this device. We report single photon detection of 5.27% at 1310 nm and a dark count rate of 534 kHz at 80 K for a Ge-on-Si single photon avalanche diode. Dark count rate is the lowest for a Ge-on-Si single photon detector in this range of temperatures while maintaining competitive detection efficiency. A jitter of 105 ps was measured for this device.

  8. Biomarker detection of global infectious diseases based on magnetic particles.

    Science.gov (United States)

    Carinelli, Soledad; Martí, Mercè; Alegret, Salvador; Pividori, María Isabel

    2015-09-25

    Infectious diseases affect the daily lives of millions of people all around the world, and are responsible for hundreds of thousands of deaths, mostly in the developing world. Although most of these major infectious diseases are treatable, the early identification of individuals requiring treatment remains a major issue. The incidence of these diseases would be reduced if rapid diagnostic tests were widely available at the community and primary care level in low-resource settings. Strong research efforts are thus being focused on replacing standard clinical diagnostic methods, such as the invasive detection techniques (biopsy or endoscopy) or expensive diagnostic and monitoring methods, by affordable and sensitive tests based on novel biomarkers. The development of new methods that are needed includes solid-phase separation techniques. In this context, the integration of magnetic particles within bioassays and biosensing devices is very promising since they greatly improve the performance of a biological reaction. The diagnosis of clinical samples with magnetic particles can be easily achieved without pre-enrichment, purification or pretreatment steps often required for standard methods, simplifying the analytical procedures. The biomarkers can be specifically isolated and preconcentrated from complex biological matrixes by magnetic actuation, increasing specificity and the sensitivity of the assay. This review addresses these promising features of the magnetic particles for the detection of biomarkers in emerging technologies related with infectious diseases affecting global health, such as malaria, influenza, dengue, tuberculosis or HIV. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Single Molecule Detection in Living Biological Cells using Carbon Nanotube Optical Probes

    Science.gov (United States)

    Strano, Michael

    2009-03-01

    Nanoscale sensing elements offer promise for single molecule analyte detection in physically or biologically constrained environments. Molecular adsorption can be amplified via modulation of sharp singularities in the electronic density of states that arise from 1D quantum confinement [1]. Single-walled carbon nanotubes (SWNT), as single molecule optical sensors [2-3], offer unique advantages such as photostable near-infrared (n-IR) emission for prolonged detection through biological media, single-molecule sensitivity and, nearly orthogonal optical modes for signal transduction that can be used to identify distinct classes of analytes. Selective binding to the SWNT surface is difficult to engineer [4]. In this lecture, we will briefly review the immerging field of fluorescent diagnostics using band gap emission from SWNT. In recent work, we demonstrate that even a single pair of SWNT provides at least four optical modes that can be modulated to uniquely fingerprint chemical agents by the degree to which they alter either the emission band intensity or wavelength. We validate this identification method in vitro by demonstrating detection and identification of six genotoxic analytes, including chemotherapeutic drugs and reactive oxygen species (ROS), which are spectroscopically differentiated into four distinct classes. We also demonstrate single-molecule sensitivity in detecting hydrogen peroxide, one of the most common genotoxins and an important cellular signal. Finally, we employ our sensing and fingerprinting method of these analytes in real time within live 3T3 cells, demonstrating the first multiplexed optical detection from a nanoscale biosensor and the first label-free tool to optically discriminate between genotoxins. We will also discuss our recent efforts to fabricate biomedical sensors for real time detection of glucose and other important physiologically relevant analytes in-vivo. The response of embedded SWNT in a swellable hydrogel construct to

  10. The temporal evolution process from fluorescence bleaching to clean Raman spectra of single solid particles optically trapped in air

    Science.gov (United States)

    Gong, Zhiyong; Pan, Yong-Le; Videen, Gorden; Wang, Chuji

    2017-12-01

    We observe the entire temporal evolution process of fluorescence and Raman spectra of single solid particles optically trapped in air. The spectra initially contain strong fluorescence with weak Raman peaks, then the fluorescence was bleached within seconds, and finally only the clean Raman peaks remain. We construct an optical trap using two counter-propagating hollow beams, which is able to stably trap both absorbing and non-absorbing particles in air, for observing such temporal processes. This technique offers a new method to study dynamic changes in the fluorescence and Raman spectra from a single optically trapped particle in air.

  11. Inclusive photoproduction of single charged particles at high pT

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Flower, P.S.; Hallewell, G.; Morris, J.A.G.; Morris, J.V.; Paterson, C.N.; Sharp, P.H.; Atkinson, M.; Brook, N.; Coyle, P.; Dickinson, B.; Donnachie, A.; Doyle, A.T.; Ellison, R.J.; Foster, J.M.; Hughes-Jones, R.E.; Ibbotson, M.; Kolya, S.D.; Lafferty, G.D.; McCann, H.; McManus, C.; Mercer, D.; Ottewell, P.J.; Reid, D.; Thompson, R.J.; Waterhouse, J.; Barberis, D.; Davenport, M.; Eades, J.; McClatchey, R.; Brodbeck, T.J.; Charity, T.; Clegg, A.B.; Henderson, R.C.W.; Hickman, M.T.; Keemer, N.R.; Newton, D.; O'Connor, A.; Wilson, G.W.; Danaher, S.; Galbraith, W.; Thacker, N.A.; Thompson, L.

    1989-01-01

    Single charged-particle inclusive cross sections for photon, pion and kaon beams on hydrogen at the CERN-SPS are presented as functions of p T and x F . Data cover the range 0.0 T F T < 1.6 GeV/c for the photon-induced data. Using the hadron-induced data to estimate the hadronic behaviour of the photon, the difference distributions and ratios of cross sections are a measure of the contribution of the point-like photon interactions. The data are compared with QCD calculations and show broadly similar features. (orig.)

  12. Analysis and differentiation of mineral dust by single particle laser mass spectrometry

    International Nuclear Information System (INIS)

    Gallavardin, S. J.; Lohmann, U.; Cziczo, Daniel J.

    2008-01-01

    This study evaluates the potential of single particle laser desorption/ionization mass spectrometry for the analysis of atmospherically relevant mineral dusts. Samples of hematite, goethite, calcium carbonate, calcium sulfate, silica, quartz, montmorrillonite, kaolinite, illite, hectorite, wollastonite and nephelinsyenit were investigated in positive and negative ion mode with a monopolar time-of-flight mass spectrometer where the desorption/ionization step was performed with a 193 nm excimer laser (∼10 9 W/cm 2 ). Particle size ranged from 500 nm to 3 (micro)m. Positive mass spectra mainly provide elemental composition whereas negative ion spectra provide information on element speciation and of a structural nature. The iron oxide, calcium-rich and aluminosilicate nature of particles is established in positive ion mode. The differentiation of calcium materials strongly relies on the calcium counter-ions in negative mass spectra. Aluminosilicates can be differentiated in both positive and negative ion mode using the relative abundance of various aluminum and silicon ions

  13. Silver speciation and characterization of nanoparticles released from plastic food containers by single particle ICPMS.

    Science.gov (United States)

    Ramos, K; Gómez-Gómez, M M; Cámara, C; Ramos, L

    2016-05-01

    Silver migration from a commercial baby feeding bottle and a food box containing AgNPs, as confirmed by SEM-EDX analysis, was evaluated using food simulant solutions [i.e., water, 3% (v/v) acetic acid, and 10% and 90% (v/v) ethanol]. Silver release was investigated at temperatures in the 20-70°C range using contact times of up to 10 days. Migration of silver from the food box was in all cases 2 to 3 orders of magnitude higher than that observed for the baby bottle, although the total silver content in the original box material was half of that found in the baby bottle. As expected, for both food containers, silver migration depended on both the nature of the tested solution and the applied conditions. The highest release was observed for 3% acetic acid at 70°C for 2h, corresponding to 62ngdm(2) and 1887ngdm(-2) of silver for the baby bottle and the food box, respectively. Single particle-inductively coupled plasma mass spectrometry (SP-ICPMS) was used to characterise and quantify AgNPs in the food simulants extracts. Sample preparation was optimized to preserve AgNPs integrity. The experimental parameters affecting AgNPs detection, sizing and quantification by SP-ICPMS were also optimised. Analyses of water and acidic extracts revealed the presence of both dissolved silver and AgNPs. Small AgNPs (in the 18-30nm range) and particle number concentrations within the 4-1510 10(6)L(-1) range were detected, corresponding to only 0.1-8.6% of the total silver released from these materials. The only exception was AgNPs migrated into water at 40°C and 70°C from the food box, which accounted for as much as 34% and 69% of the total silver content, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Combined Data with Particle Swarm Optimization for Structural Damage Detection

    Directory of Open Access Journals (Sweden)

    Fei Kang

    2013-01-01

    Full Text Available This paper proposes a damage detection method based on combined data of static and modal tests using particle swarm optimization (PSO. To improve the performance of PSO, some immune properties such as selection, receptor editing, and vaccination are introduced into the basic PSO and an improved PSO algorithm is formed. Simulations on three benchmark functions show that the new algorithm performs better than PSO. The efficiency of the proposed damage detection method is tested on a clamped beam, and the results demonstrate that it is more efficient than PSO, differential evolution, and an adaptive real-parameter simulated annealing genetic algorithm.

  15. First-order reversal curves of single domain particles: diluted random assemblages and chains

    Science.gov (United States)

    Egli, R.

    2009-04-01

    Exact magnetic models can be used to calculate first-order reversal curves (FORC) of single domain (SD) particle assemblages, as shown by Newell [2005] for the case of isolated Stoner-Wohlfarth particles. After overcoming experimental difficulties, a FORC diagram sharing many similarities to Newell's model has been measured on a lake sediment sample (see A.P. Chen et al., "Quantification of magnetofossils using first-order reversal curves", EGU General Assembly 2009, Abstracts Vol. 11, EGU2009-10719). This sample contains abundant magnetofossils, as shown by coercivity analysis and electron microscopy, therefore suggesting that well dispersed, intact magnetosome chains are the main SD carriers. Subtle differences between the reversible and the irreversible contributions of the measured FORC distribution suggest that magnetosome chains might not be correctly described by the Stoner-Wohlfarth model. To better understand the hysteresis properties of such chains, a simple magnetic model has been implemented, taking dipole-dipole interactions between particles within the same chain into account. The model results depend on the magnetosome elongation, the number of magnetosomes in a chain, and the gap between them. If the chain axis is subparallel to the applied field, the magnetic moment reverses by a pseudo-fanning mode, which is replaced by a pseudo-coherent rotation mode at greater angles. These reversal modes are intrinsically different from coherent rotation assumed Stoner-Wohlfarth model, resulting in FORC diagrams with a smaller reversible component. On the other hand, isolated authigenic SD particles can precipitate in the sediment matrix, as it might occur for pedogenic magnetite. In this case, an assembly of randomly located particles provides a possible model for the resulting FORC diagram. If the concentration of the particles is small, each particle is affected by a random interaction field whose statistical distribution can be calculated from first

  16. Direct detection of a single photon by humans

    Science.gov (United States)

    Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  17. Detection of kinetic change points in piece-wise linear single molecule motion

    Science.gov (United States)

    Hill, Flynn R.; van Oijen, Antoine M.; Duderstadt, Karl E.

    2018-03-01

    Single-molecule approaches present a powerful way to obtain detailed kinetic information at the molecular level. However, the identification of small rate changes is often hindered by the considerable noise present in such single-molecule kinetic data. We present a general method to detect such kinetic change points in trajectories of motion of processive single molecules having Gaussian noise, with a minimum number of parameters and without the need of an assumed kinetic model beyond piece-wise linearity of motion. Kinetic change points are detected using a likelihood ratio test in which the probability of no change is compared to the probability of a change occurring, given the experimental noise. A predetermined confidence interval minimizes the occurrence of false detections. Applying the method recursively to all sub-regions of a single molecule trajectory ensures that all kinetic change points are located. The algorithm presented allows rigorous and quantitative determination of kinetic change points in noisy single molecule observations without the need for filtering or binning, which reduce temporal resolution and obscure dynamics. The statistical framework for the approach and implementation details are discussed. The detection power of the algorithm is assessed using simulations with both single kinetic changes and multiple kinetic changes that typically arise in observations of single-molecule DNA-replication reactions. Implementations of the algorithm are provided in ImageJ plugin format written in Java and in the Julia language for numeric computing, with accompanying Jupyter Notebooks to allow reproduction of the analysis presented here.

  18. g factors and the interplay of collective and single-particle degrees of freedom in superdeformed mass-190 nuclei

    International Nuclear Information System (INIS)

    Sun, Yang; Zhang, Jing-ye; Guidry, Mike

    2001-01-01

    Interplay of collective and single-particle degrees of freedom is a common phenomenon in strongly correlated many-body systems. Despite many successful efforts in the study of superdeformed nuclei, there is still unexplored physics that can be best understood only through the nuclear magnetic properties. We point out that study of the gyromagnetic factor (g factor) may open a unique opportunity for understanding superdeformed structure. Our calculations suggest that investigation of the g-factor dependence on spin and particle number can provide important information on single-particle structure and its interplay with collective motion in the superdeformed mass-190 nuclei. Modern experimental techniques combined with the new generation of sensitive detectors should be capable of testing our predictions

  19. Single Particle Potential of a Σ Hyperon in Nuclear Matter. II Rearrangement Effects

    International Nuclear Information System (INIS)

    Dabrowski, J.

    2000-01-01

    The rearrangement contribution to the real part of the single particle potential of a Σ hyperon in nuclear matter, U Σ , is investigated. The isospin and spin dependent parts of U Σ are considered. Results obtained for four models of the Nijmegen baryon-baryon interaction are presented and discussed. (author)

  20. Fission Detection Using the Associated Particle Technique

    International Nuclear Information System (INIS)

    R.P. Keegan; J.P. Hurley; J.R. Tinsley; R. Trainham; S.C. Wilde

    2008-01-01

    A beam of tagged 14 MeV neutrons from the deuterium-tritium (DT) reaction is used to induce fission in a target composed of depleted uranium. The generator yield is 10 7 neutrons/second radiated into a 4 x 4 in. NaI detectors are used for gamma-ray detection. The fission process is known to produce multiple gamma-rays and neutrons. Triple coincidences (α-γ-γ) are measured as a function of neutron flight time up to 90 ns after fission, where the α-particle arises from the DT reaction. A sudden increase in the triple coincidence rate at the location of the material is used to localize and detect fission in the interrogated target. Comparisons are made with experiment runs where lead, tungsten, and iron were used as target materials. The triple coincidence response profile from depleted uranium is noted to be different to those observed from the other target materials. The response from interrogation targets composed of fissile material is anticipated to be even more unique than that observed from depleted uranium

  1. A method for detecting the presence of organic fraction in nucleation mode sized particles

    Directory of Open Access Journals (Sweden)

    P. Vaattovaara

    2005-01-01

    Full Text Available New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d<20 nm and the lower end of Aitken mode particles (d≤50 nm is still insufficient. In this work, we have applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer method to shed light on the presence of an organic fraction in the nucleation mode size class in different atmospheric environments. The basic principle of the organic fraction detection is based on our laboratory UFO-TDMA measurements with organic and inorganic compounds. Our laboratory measurements indicate that the usefulness of the UFO-TDMA in the field experiments would arise especially from the fact that atmospherically the most relevant inorganic compounds do not grow in subsaturated ethanol vapor, when particle size is 10 nm in diameter and saturation ratio is about 86% or below it. Furthermore, internally mixed particles composed of ammonium bisulfate and sulfuric acid with sulfuric acid mass fraction ≤33% show no growth at 85% saturation ratio. In contrast, 10 nm particles composed of various oxidized organic compounds of atmospheric relevance are able to grow in those conditions. These discoveries indicate that it is possible to detect the presence of organics in atmospheric nucleation mode sized particles using the UFO-TDMA method. In the future, the UFO-TDMA is expected to be an important aid to describe the composition of atmospheric newly-formed particles.

  2. Single-Molecule Fluorescence Microscopy Reveals Local Diffusion Coefficients in the Pore Network of an Individual Catalyst Particle

    NARCIS (Netherlands)

    Hendriks, Frank|info:eu-repo/dai/nl/412642697; Meirer, Florian; Kubarev, Alexey V.; Ristanovic, Zoran|info:eu-repo/dai/nl/328233005; Roeffaers, Maarten B J; Vogt, Eelco T. C.|info:eu-repo/dai/nl/073717398; Bruijnincx, Pieter C. A.|info:eu-repo/dai/nl/33799529X; Weckhuysen, Bert M.|info:eu-repo/dai/nl/285484397

    2017-01-01

    We used single-molecule fluorescence microscopy to study self-diffusion of a feedstock-like probe molecule with nanometer accuracy in the macropores of a micrometer-sized, real-life fluid catalytic cracking (FCC) particle. Movies of single fluorescent molecules allowed their movement through the

  3. Charged particle spectra in π-p,π-d and π-C interactions at 38 GeV/c with single-particle high pT trigger

    International Nuclear Information System (INIS)

    Boos, E.G.; Mosienko, A.M.; Baerwolff, H.

    1987-01-01

    Angular momentum distributions of charged secondaries from 38 GeV/c π - p, π - d and π - C interactions triggered on at least one particle with p T >or approx. 1 GeV/c at an 90 deg πN c.m.s angle have been investigated with the spectrometer RISK (a streamer chamber placed into a magnet). Transversal momentum spectra of secondaries in the 0.4-2.4 GeV/c p T -range including triggering particles are quite well fitted with the exponential function for all nuclei studied and for particles of different charges. The azimuthal angle distribution of secondaries (an angle relative to the p T -tilde of the triggering particle) for both trigger-like and trigger-unlike charges is anisotropic, preferring the direction away from the triggering particle. The mean charge distribution of associated particles is discussed. A small fraction of triggering particles is due to neutral strange particle decays. Many Λ 0 -hyperons were detected among those neutral strange triggers

  4. Detecting charging state of ultra-fine particles: instrumental development and ambient measurements

    Directory of Open Access Journals (Sweden)

    L. Laakso

    2007-01-01

    Full Text Available The importance of ion-induced nucleation in the lower atmosphere has been discussed for a long time. In this article we describe a new instrumental setup – Ion-DMPS – which can be used to detect contribution of ion-induced nucleation on atmospheric new particle formation events. The device measures positively and negatively charged particles with and without a bipolar charger. The ratio between "charger off" to "charger on" describes the charging state of aerosol particle population with respect to equilibrium. Values above one represent more charges than in an equilibrium (overcharged state, and values below unity stand for undercharged situation, when there is less charges in the particles than in the equilibrium. We performed several laboratory experiments to test the operation of the instrument. After the laboratory tests, we used the device to observe particle size distributions during atmospheric new particle formation in a boreal forest. We found that some of the events were clearly dominated by neutral nucleation but in some cases also ion-induced nucleation contributed to the new particle formation. We also found that negative and positive ions (charged particles behaved in a different manner, days with negative overcharging were more frequent than days with positive overcharging.

  5. Single-atom-resolved fluorescence imaging of an atomic Mott insulator

    DEFF Research Database (Denmark)

    Sherson, Jacob; Weitenberg, Christof; Andres, Manuel

    2010-01-01

    in situ images of a quantum fluid in which each underlying quantum particle is detected. Here we report fluorescence imaging of strongly interacting bosonic Mott insulators in an optical lattice with single-atom and single-site resolution. From our images, we fully reconstruct the atom distribution...

  6. Electrocatalytic oxidation of alcohols on single gold particles in highly ordered SiO2 cavities

    International Nuclear Information System (INIS)

    Li, Na; Zhou, Qun; Tian, Shu; Zhao, Hong; Li, Xiaowei; Adkins, Jason; Gu, Zhuomin; Zhao, Lili; Zheng, Junwei

    2013-01-01

    In the present work, we report a new and simple approach for preparing a highly ordered Au (1 1 1) nanoparticle (NP) array in SiO 2 cavities on indium-doped tin oxide (ITO) electrodes. We fabricated a SiO 2 cavity array on the surface of an ITO electrode using highly ordered self-assembly of polystyrene spheres as a template. Gold NPs were electrodeposited at the bottom of the SiO 2 cavities, and single gold NPs dominated with (1 1 1) facets were generated in each cavity by annealing the electrode at a high temperature. Such (1 1 1) facets were the predominate trait of the single gold particle which exhibited considerable electrocatalytic activity toward oxidation of methanol, ethanol, and glycerol. This has been attributed to the formation of incipient hydrous oxides at unusually low potential on the specific (1 1 1) facet of the gold particles. Moreover, each cavity of the SiO 2 possibly behaves as an independent electrochemical cell in which the methanol molecules are trapped; this produces an environment advantageous to catalyzing electrooxidation. The oxidation of methanol on the electrodes is a mixed control mechanism (both by diffusion and electrode kinetics). This strategy both provided an approach to study electrochemical reactions on a single particle in a microenvironment and may supply a way to construct alcohols sensors

  7. Direct uranium isotope ratio analysis of single micrometer-sized glass particles

    International Nuclear Information System (INIS)

    Kappel, Stefanie; Boulyga, Sergei F.; Prohaska, Thomas

    2012-01-01

    We present the application of nanosecond laser ablation (LA) coupled to a ‘Nu Plasma HR’ multi collector inductively coupled plasma mass spectrometer (MC-ICP-MS) for the direct analysis of U isotope ratios in single, 10–20 μm-sized, U-doped glass particles. Method development included studies with respect to (1) external correction of the measured U isotope ratios in glass particles, (2) the applied laser ablation carrier gas (i.e. Ar versus He) and (3) the accurate determination of lower abundant 236 U/ 238 U isotope ratios (i.e. 10 −5 ). In addition, a data processing procedure was developed for evaluation of transient signals, which is of potential use for routine application of the developed method. We demonstrate that the developed method is reliable and well suited for determining U isotope ratios of individual particles. Analyses of twenty-eight S1 glass particles, measured under optimized conditions, yielded average biases of less than 0.6% from the certified values for 234 U/ 238 U and 235 U/ 238 U ratios. Experimental results obtained for 236 U/ 238 U isotope ratios deviated by less than −2.5% from the certified values. Expanded relative total combined standard uncertainties U c (k = 2) of 2.6%, 1.4% and 5.8% were calculated for 234 U/ 238 U, 235 U/ 238 U and 236 U/ 238 U, respectively. - Highlights: ► LA-MC-ICP-MS was fully validated for the direct analysis of individual particles. ► Traceability was established by using an IRMM glass particle reference material. ► Measured U isotope ratios were in agreement with the certified range. ► A comprehensive total combined uncertainty evaluation was performed. ► The analysis of 236 U/ 238 U isotope ratios was improved by using a deceleration filter.

  8. The use of silicon devices (diodes, RAMs, etc.) for alpha particle detection

    International Nuclear Information System (INIS)

    Agosteo, S.; Foglio Para, A.

    1993-01-01

    Silicon electronic devices (diodes, random access memories (RAMs), etc.) can be employed in alpha particle detection and spectroscopy with a good energy resolution. The detection mechanisms are first discussed; the performances of these devices operating in the pulse and in the current mode are then described starting from the pioneering works of the last decade. Some peculiar applications of RAMs are finally reported. (author). 7 refs, 5 figs, 1 tab

  9. Analysis of a Single Hot Particle by a Combination of Non-Destructive Analytical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Hrnecek, E.; Aldave de las Heras, L.; Bielewski, M.; Carlos, R. [EC JRC Institute for Transuranium Elements, Karlsruhe (Germany); Betti, M. [IAEA Environment Laboratories (Monaco)

    2013-07-15

    Radioactive substances are often released to the environment in the form of particles. The determination of their chemical composition is a key factor in the overall understanding of their environmental behaviour. The aim of this investigation was to identify the source of one single radioactive particle collected from the Irish Sea and to understand its fate in the environment and in human body fluids. As the particle was supposed to be analysed for its dissolution behaviour in humans after ingestion, it was necessary to gain as much information as possible beforehand on the chemical and isotopic composition by means of non-destructive analysis such as SEM, SIMS, {mu}-XRF and {mu}-XANES. In this paper, an overview of the different non-destructive methods applied for the analysis of this particle and the results obtained is given. Additionally, the dissolution behaviour in human digestive solutions is discussed. (author)

  10. Temperature effects on drift of suspended single-domain particles induced by the Magnus force

    Science.gov (United States)

    Denisov, S. I.; Lyutyy, T. V.; Reva, V. V.; Yermolenko, A. S.

    2018-03-01

    We study the temperature dependence of the drift velocity of single-domain ferromagnetic particles induced by the Magnus force in a dilute suspension. A set of stochastic equations describing the translational and rotational dynamics of particles is derived, and the particle drift velocity that depends on components of the average particle magnetization is introduced. The Fokker-Planck equation for the probability density of magnetization orientations is solved analytically in the limit of strong thermal fluctuations for both the planar rotor and general models. Using these solutions, we calculate the drift velocity and show that the out-of-plane fluctuations of magnetization, which are not accounted for in the planar rotor model, play an important role. In the general case of arbitrary fluctuations, we investigate the temperature dependence of the drift velocity by numerically simulating a set of effective stochastic differential equations for the magnetization dynamics.

  11. Evaluation strategies for isotope ratio measurements of single particles by LA-MC-ICPMS.

    Science.gov (United States)

    Kappel, S; Boulyga, S F; Dorta, L; Günther, D; Hattendorf, B; Koffler, D; Laaha, G; Leisch, F; Prohaska, T

    2013-03-01

    Data evaluation is a crucial step when it comes to the determination of accurate and precise isotope ratios computed from transient signals measured by multi-collector-inductively coupled plasma mass spectrometry (MC-ICPMS) coupled to, for example, laser ablation (LA). In the present study, the applicability of different data evaluation strategies (i.e. 'point-by-point', 'integration' and 'linear regression slope' method) for the computation of (235)U/(238)U isotope ratios measured in single particles by LA-MC-ICPMS was investigated. The analyzed uranium oxide particles (i.e. 9073-01-B, CRM U010 and NUSIMEP-7 test samples), having sizes down to the sub-micrometre range, are certified with respect to their (235)U/(238)U isotopic signature, which enabled evaluation of the applied strategies with respect to precision and accuracy. The different strategies were also compared with respect to their expanded uncertainties. Even though the 'point-by-point' method proved to be superior, the other methods are advantageous, as they take weighted signal intensities into account. For the first time, the use of a 'finite mixture model' is presented for the determination of an unknown number of different U isotopic compositions of single particles present on the same planchet. The model uses an algorithm that determines the number of isotopic signatures by attributing individual data points to computed clusters. The (235)U/(238)U isotope ratios are then determined by means of the slopes of linear regressions estimated for each cluster. The model was successfully applied for the accurate determination of different (235)U/(238)U isotope ratios of particles deposited on the NUSIMEP-7 test samples.

  12. Efficient alpha particle detection by CR-39 applying 50 Hz-HV electrochemical etching method

    International Nuclear Information System (INIS)

    Sohrabi, M.; Soltani, Z.

    2016-01-01

    Alpha particles can be detected by CR-39 by applying either chemical etching (CE), electrochemical etching (ECE), or combined pre-etching and ECE usually through a multi-step HF-HV ECE process at temperatures much higher than room temperature. By applying pre-etching, characteristics responses of fast-neutron-induced recoil tracks in CR-39 by HF-HV ECE versus KOH normality (N) have shown two high-sensitivity peaks around 5–6 and 15–16 N and a large-diameter peak with a minimum sensitivity around 10–11 N at 25°C. On the other hand, 50 Hz-HV ECE method recently advanced in our laboratory detects alpha particles with high efficiency and broad registration energy range with small ECE tracks in polycarbonate (PC) detectors. By taking advantage of the CR-39 sensitivity to alpha particles, efficacy of 50 Hz-HV ECE method and CR-39 exotic responses under different KOH normalities, detection characteristics of 0.8 MeV alpha particle tracks were studied in 500 μm CR-39 for different fluences, ECE duration and KOH normality. Alpha registration efficiency increased as ECE duration increased to 90 ± 2% after 6–8 h beyond which plateaus are reached. Alpha track density versus fluence is linear up to 10 6  tracks cm −2 . The efficiency and mean track diameter versus alpha fluence up to 10 6  alphas cm −2 decrease as the fluence increases. Background track density and minimum detection limit are linear functions of ECE duration and increase as normality increases. The CR-39 processed for the first time in this study by 50 Hz-HV ECE method proved to provide a simple, efficient and practical alpha detection method at room temperature. - Highlights: • Alpha particles of 0.8 MeV were detected in CR-39 by 50 Hz-HV ECE method. • Efficiency/track diameter was studied vs fluence and time for 3 KOH normality. • Background track density and minimum detection limit vs duration were studied. • A new simple, efficient and low-cost alpha detection method

  13. Stochastic transport of particles across single barriers

    International Nuclear Information System (INIS)

    Kreuter, Christian; Siems, Ullrich; Henseler, Peter; Nielaba, Peter; Leiderer, Paul; Erbe, Artur

    2012-01-01

    Transport phenomena of interacting particles are of high interest for many applications in biology and mesoscopic systems. Here we present measurements on colloidal particles, which are confined in narrow channels on a substrate and interact with a barrier, which impedes the motion along the channel. The substrate of the particle is tilted in order for the particles to be driven towards the barrier and, if the energy gained by the tilt is large enough, surpass the barrier by thermal activation. We therefore study the influence of this barrier as well as the influence of particle interaction on the particle transport through such systems. All experiments are supported with Brownian dynamics simulations in order to complement the experiments with tests of a large range of parameter space which cannot be accessed in experiments.

  14. Particle and photon detection for a neutron radiative decay experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, T.R. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: thomas.gentile@nist.gov; Dewey, M.S.; Mumm, H.P.; Nico, J.S.; Thompson, A.K. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Chupp, T.E. [University of Michigan, Ann Arbor, MI 48109 (United States); Cooper, R.L. [University of Michigan, Ann Arbor, MI 48109 (United States)], E-mail: cooperrl@umich.edu; Fisher, B.M.; Kremsky, I.; Wietfeldt, F.E. [Tulane University, New Orleans, LA 70118 (United States); Kiriluk, K.G.; Beise, E.J. [University of Maryland, College Park, MD 20742 (United States)

    2007-08-21

    We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons and protons are guided by a 4.6 T magnetic field and detected by a silicon surface barrier detector. Photons with energies between 15 and 750 keV are registered by a detector consisting of a bismuth germanate scintillator coupled to a large area avalanche photodiode. The photon detector operates at a temperature near 80 K in the bore of a superconducting magnet. We discuss CsI as an alternative scintillator, and avalanche photodiodes for direct detection of photons in the 0.1-10 keV range.

  15. Ionizing particle detection based on phononic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Aly, Arafa H., E-mail: arafa16@yahoo.com, E-mail: arafa.hussien@science.bsu.edu.eg; Mehaney, Ahmed; Eissa, Mostafa F. [Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef (Egypt)

    2015-08-14

    Most conventional radiation detectors are based on electronic or photon collections. In this work, we introduce a new and novel type of ionizing particle detector based on phonon collection. Helium ion radiation treats tumors with better precision. There are nine known isotopes of helium, but only helium-3 and helium-4 are stable. Helium-4 is formed in fusion reactor technology and in enormous quantities during Big Bang nucleo-synthesis. In this study, we introduce a technique for helium-4 ion detection (sensing) based on the innovative properties of the new composite materials known as phononic crystals (PnCs). PnCs can provide an easy and cheap technique for ion detection compared with conventional methods. PnC structures commonly consist of a periodic array of two or more materials with different elastic properties. The two materials are polymethyl-methacrylate and polyethylene polymers. The calculations showed that the energies lost to target phonons are maximized at 1 keV helium-4 ion energy. There is a correlation between the total phonon energies and the transmittance of PnC structures. The maximum transmission for phonons due to the passage of helium-4 ions was found in the case of making polyethylene as a first layer in the PnC structure. Therefore, the concept of ion detection based on PnC structure is achievable.

  16. Photoresponsive Release from Azobenzene-Modified Single Cubic Crystal NaCl/Silica Particles

    Directory of Open Access Journals (Sweden)

    Xingmao Jiang

    2011-01-01

    Full Text Available Azobenzene ligands were uniformly anchored to the pore surfaces of nanoporous silica particles with single crystal NaCl using 4-(3-triethoxysilylpropylureidoazobenzene (TSUA. The functionalization delayed the release of NaCl significantly. The modified particles demonstrated a photocontrolled release by trans/cis isomerization of azobenzene moieties. The addition of amphiphilic solvents, propylene glycol (PG, propylene glycol propyl ether (PGPE, and dipropylene glycol propyl ether (DPGPE delayed the release in water, although the wetting behavior was improved and the delay is the most for the block molecules with the longest carbon chain. The speedup by UV irradiation suggests a strong dependence of diffusion on the switchable pore size. TGA, XRD, FTIR, and NMR techniques were used to characterize the structures.

  17. Single Nanoparticle Detection Using Optical Microcavities.

    Science.gov (United States)

    Zhi, Yanyan; Yu, Xiao-Chong; Gong, Qihuang; Yang, Lan; Xiao, Yun-Feng

    2017-03-01

    Detection of nanoscale objects is highly desirable in various fields such as early-stage disease diagnosis, environmental monitoring and homeland security. Optical microcavity sensors are renowned for ultrahigh sensitivities due to strongly enhanced light-matter interaction. This review focuses on single nanoparticle detection using optical whispering gallery microcavities and photonic crystal microcavities, both of which have been developing rapidly over the past few years. The reactive and dissipative sensing methods, characterized by light-analyte interactions, are explained explicitly. The sensitivity and the detection limit are essentially determined by the cavity properties, and are limited by the various noise sources in the measurements. On the one hand, recent advances include significant sensitivity enhancement using techniques to construct novel microcavity structures with reduced mode volumes, to localize the mode field, or to introduce optical gain. On the other hand, researchers attempt to lower the detection limit by improving the spectral resolution, which can be implemented by suppressing the experimental noises. We also review the methods of achieving a better temporal resolution by employing mode locking techniques or cavity ring up spectroscopy. In conclusion, outlooks on the possible ways to implement microcavity-based sensing devices and potential applications are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Single-Molecule Tethered Particle Motion: Stepwise Analyses of Site-Specific DNA Recombination

    Directory of Open Access Journals (Sweden)

    Hsiu-Fang Fan

    2018-05-01

    Full Text Available Tethered particle motion/microscopy (TPM is a biophysical tool used to analyze changes in the effective length of a polymer, tethered at one end, under changing conditions. The tether length is measured indirectly by recording the Brownian motion amplitude of a bead attached to the other end. In the biological realm, DNA, whose interactions with proteins are often accompanied by apparent or real changes in length, has almost exclusively been the subject of TPM studies. TPM has been employed to study DNA bending, looping and wrapping, DNA compaction, high-order DNA–protein assembly, and protein translocation along DNA. Our TPM analyses have focused on tyrosine and serine site-specific recombinases. Their pre-chemical interactions with DNA cause reversible changes in DNA length, detectable by TPM. The chemical steps of recombination, depending on the substrate and the type of recombinase, may result in a permanent length change. Single molecule TPM time traces provide thermodynamic and kinetic information on each step of the recombination pathway. They reveal how mechanistically related recombinases may differ in their early commitment to recombination, reversibility of individual steps, and in the rate-limiting step of the reaction. They shed light on the pre-chemical roles of catalytic residues, and on the mechanisms by which accessory proteins regulate recombination directionality.

  19. Single-atom detection on a chip: from realization to application

    Energy Technology Data Exchange (ETDEWEB)

    Stibor, A; Bender, H; Kuehnhold, S; Fortagh, J; Zimmermann, C; Guenther, A, E-mail: aguenth@pit.physik.uni-tuebingen.d [CQ Center for Collective Quantum Phenomena and their Applications, Eberhard-Karls-Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)

    2010-06-15

    In this paper, we describe the preparation and detection of ultracold atoms on a microchip with single-atom sensitivity. The detection scheme is based on multi-photon ionization of atoms and the subsequent guiding of the generated ions by ion optics to a channel electron multiplier. We resolve single atoms with a detection efficiency above 60%. The detector is suitable for real-time observations of static and dynamic processes in ultracold quantum gases. Although the ionization is destructive, sampling a small subset of the atomic distribution is sufficient for the determination of the desired information. We take full high-resolution spectra of ultracold atoms by ionizing only 5% of the atoms. Using an additional microwave near 6.8 GHz, the detection scheme becomes energy, position and state selective. This can be used for in situ determination of the energy distribution and temperature of atom clouds inside the trap and applied for future correlation measurements.

  20. Induction of prophage lambda by chlorinated organics: Detection of some single-species/single-site carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, D.M.; Brooks, H.G. (Environmental Protection Agency, Research Triangle Park, NC (United States))

    1992-01-01

    Twenty-eight chlorinated organic compounds were evaluated for their ability to induce DNA damage using the Microscreen prophage-induction assay in Escherichia coli. Comparison of the performance characteristics of the prophage-induction and Salmonella assays to rodent carcinogenicity assays showed that the prophage-induction assay had a somewhat higher specificity than did the Salmonella assay (70% vs. 50%); sensitivity, concordance, and positive and negative predictivity were similar for the two microbial assays. The Microscreen prophage-induction assay failed to detect eight carcinogens, perhaps due to toxicity or other unknown factors; five of these eight carcinogens were detected by the Salmonella assay. However, the prophage-induction assay did detect six carcinogens that were not detected by the Salmonella assay, and five of these were single-species, single-site carcinogens, mostly mouse liver carcinogens. Some of these carcinogens, such as the chloroethanes, produce free radicals, which may be the basis for their carcinogenicity and ability to induce prophage. The prophage-induction (or other SOS) assay may be useful in identifying some genotoxic chlorinated carcinogens that induce DNA damage that do not revert the standard Salmonella tester strains.

  1. Tailoring particle translocation via dielectrophoresis in pore channels

    Science.gov (United States)

    Tanaka, Shoji; Tsutsui, Makusu; Theodore, Hu; Yuhui, He; Arima, Akihide; Tsuji, Tetsuro; Doi, Kentaro; Kawano, Satoyuki; Taniguchi, Masateru; Kawai, Tomoji

    2016-01-01

    Understanding and controlling electrophoretic motions of nanoscopic objects in fluidic channels are a central challenge in developing nanopore technology for molecular analyses. Although progress has been made in slowing the translocation velocity to meet the requirement for electrical detections of analytes via picoampere current measurements, there exists no method useful for regulating particle flows in the transverse directions. Here, we report the use of dielectrophoresis to manipulate the single-particle passage through a solid-state pore. We created a trap field by applying AC voltage between electrodes embedded in a low-aspect-ratio micropore. We demonstrated a traffic control of particles to go through center or near side surface via the voltage frequency. We also found enhanced capture efficiency along with faster escaping speed of particles by virtue of the AC-mediated electroosmosis. This method is compatible with nanopore sensing and would be widely applied for reducing off-axis effects to achieve single-molecule identification. PMID:27527126

  2. Direct single-molecule dynamic detection of chemical reactions.

    Science.gov (United States)

    Guan, Jianxin; Jia, Chuancheng; Li, Yanwei; Liu, Zitong; Wang, Jinying; Yang, Zhongyue; Gu, Chunhui; Su, Dingkai; Houk, Kendall N; Zhang, Deqing; Guo, Xuefeng

    2018-02-01

    Single-molecule detection can reveal time trajectories and reaction pathways of individual intermediates/transition states in chemical reactions and biological processes, which is of fundamental importance to elucidate their intrinsic mechanisms. We present a reliable, label-free single-molecule approach that allows us to directly explore the dynamic process of basic chemical reactions at the single-event level by using stable graphene-molecule single-molecule junctions. These junctions are constructed by covalently connecting a single molecule with a 9-fluorenone center to nanogapped graphene electrodes. For the first time, real-time single-molecule electrical measurements unambiguously show reproducible large-amplitude two-level fluctuations that are highly dependent on solvent environments in a nucleophilic addition reaction of hydroxylamine to a carbonyl group. Both theoretical simulations and ensemble experiments prove that this observation originates from the reversible transition between the reactant and a new intermediate state within a time scale of a few microseconds. These investigations open up a new route that is able to be immediately applied to probe fast single-molecule physics or biophysics with high time resolution, making an important contribution to broad fields beyond reaction chemistry.

  3. Single-particle thermal diffusion of charged colloids: Double-layer theory in a temperature gradient

    NARCIS (Netherlands)

    Dhont, J.K.G.; Briels, Willem J.

    2008-01-01

    The double-layer contribution to the single-particle thermal diffusion coefficient of charged, spherical colloids with arbitrary double-layer thickness is calculated and compared to experiments. The calculation is based on an extension of the Debye-Hückel theory for the double-layer structure that

  4. Single-particle density matrix and superfluidity in the two-dimensional Bose Coulomb fluid

    International Nuclear Information System (INIS)

    Minguzzi, A.; Tosi, M.P.; Davoudi, B.

    2002-01-01

    A study by Magro and Ceperley [Phys. Rev. Lett. 73, 826 (1994)] has shown that the ground state of the two-dimensional fluid of charged bosons with logarithmic interactions is not Bose condensed, but exhibits algebraic off-diagonal order in the single-particle density matrix ρ(r). We use a hydrodynamic Hamiltonian expressed in terms of density and phase operators, in combination with an f-sum rule on the superfluid fraction, to reproduce these results and to extend the evaluation of the density matrix to finite temperature T. This approach allows us to treat the liquid as a superfluid in the absence of a condensate. The algebraic decay of the one-body density matrix is due to correlations between phase fluctuations, and we find that the exponent in the power law is determined by the superfluid density n s (T). We also find that the plasmon gap in the single-particle energy spectrum at long wavelengths decreases with increasing T and closes at the critical temperature for the onset of superfluidity

  5. Pairing in the BCS and LN approximations using continuum single particle level density

    International Nuclear Information System (INIS)

    Id Betan, R.M.; Repetto, C.E.

    2017-01-01

    Understanding the properties of drip line nuclei requires to take into account the correlations with the continuum spectrum of energy of the system. This paper has the purpose to show that the continuum single particle level density is a convenient way to consider the pairing correlation in the continuum. Isospin mean-field and isospin pairing strength are used to find the Bardeen–Cooper–Schrieffer (BCS) and Lipkin–Nogami (LN) approximate solutions of the pairing Hamiltonian. Several physical properties of the whole chain of the Tin isotope, as gap parameter, Fermi level, binding energy, and one- and two-neutron separation energies, were calculated and compared with other methods and with experimental data when they exist. It is shown that the use of the continuum single particle level density is an economical way to include explicitly the correlations with the continuum spectrum of energy in large scale mass calculation. It is also shown that the computed properties are in good agreement with experimental data and with more sophisticated treatment of the pairing interaction.

  6. Test of a Diamond Detector Using Unbunched Beam Halo Particles

    CERN Document Server

    Dehning, B; Pernegger, H; Dobos, D; Frais-Kolbl, H; Griesmayer, E

    2010-01-01

    A pCVD diamond detector has been evaluated as a beam loss monitor for future applications in the LHC accelerator. The test monitor was mounted in the SPS BA5 downstream of a LHC collimator during the LHC beam set-up. CVD diamond particle detectors are already in use in the CERN experiments ATLAS, CMS, LHCb and Alice. This is a proven technology with high radiation tolerance and very fast signal read-out. It can be used for single-particle detection, as well as for measuring particle cascades, for timing measurements on the nanosecond scale and for beam protection systems. Despite the read-out being made through 250 m of CK50 cable, the tests have shown a very good signal-to-noise ratio of 6.8, an excellent double-pulse resolution of less than 5 ns and a high dynamic range of 1:350 MIP particles. The efficiency of particle detection is practically 100% for charged particles.

  7. Particle levitation and laboratory scattering

    International Nuclear Information System (INIS)

    Reid, Jonathan P.

    2009-01-01

    Measurements of light scattering from aerosol particles can provide a non-intrusive in situ method for characterising particle size distributions, composition, refractive index, phase and morphology. When coupled with techniques for isolating single particles, considerable information on the evolution of the properties of a single particle can be gained during changes in environmental conditions or chemical processing. Electrostatic, acoustic and optical techniques have been developed over many decades for capturing and levitating single particles. In this review, we will focus on studies of particles in the Mie size regime and consider the complimentarity of electrostatic and optical techniques for levitating particles and elastic and inelastic light scattering methods for characterising particles. In particular, we will review the specific advantages of establishing a single-beam gradient force optical trap (optical tweezers) for manipulating single particles or arrays of particles. Recent developments in characterising the nature of the optical trap, in applying elastic and inelastic light scattering measurements for characterising trapped particles, and in manipulating particles will be considered.

  8. Tonneau: a multidetector array for charged particle and light fragment 4π detection

    International Nuclear Information System (INIS)

    Peghaire, A.; Zwieglinski, B.; Rosato, E.; Jin, G.M.; Kasagi, J.; Doubre, H.; Peter, J.; Guilbault, F.; Lebrun, C.; Cassagnou, Y.; Legrain, R.

    1989-01-01

    The central part of the light-particle detection unit for the GANIL multidetector is a spherical (80 cm radius) shell of 2 mm thick NE 102A plastic scintillator. It spans the range of polar angles from θ = 30 0 - 150 0 and the azimuthal range φ = 0 0 - 360 0 , and it is segmented into 72 individual Δθ = 60 0 and Δφ = 10 0 wide detection modules. Each module is viewed by a photomultiplier at each end which provide information on the particle impact position, atomic number Z and velocity. The performance of the modules was studied with an α-source and during several experiments with heavy ion beams from 25 up to 85 MeV/amu

  9. Evaluation of Aerosol Mixing State Classes in the GISS Modele-matrix Climate Model Using Single-particle Mass Spectrometry Measurements

    Science.gov (United States)

    Bauer, Susanne E.; Ault, Andrew; Prather, Kimberly A.

    2013-01-01

    Aerosol particles in the atmosphere are composed of multiple chemical species. The aerosol mixing state, which describes how chemical species are mixed at the single-particle level, provides critical information on microphysical characteristics that determine the interaction of aerosols with the climate system. The evaluation of mixing state has become the next challenge. This study uses aerosol time-of-flight mass spectrometry (ATOFMS) data and compares the results to those of the Goddard Institute for Space Studies modelE-MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) model, a global climate model that includes a detailed aerosol microphysical scheme. We use data from field campaigns that examine a variety of air mass regimens (urban, rural, and maritime). At all locations, polluted areas in California (Riverside, La Jolla, and Long Beach), a remote location in the Sierra Nevada Mountains (Sugar Pine) and observations from Jeju (South Korea), the majority of aerosol species are internally mixed. Coarse aerosol particles, those above 1 micron, are typically aged, such as coated dust or reacted sea-salt particles. Particles below 1 micron contain large fractions of organic material, internally-mixed with sulfate and black carbon, and few external mixtures. We conclude that observations taken over multiple weeks characterize typical air mass types at a given location well; however, due to the instrumentation, we could not evaluate mass budgets. These results represent the first detailed comparison of single-particle mixing states in a global climate model with real-time single-particle mass spectrometry data, an important step in improving the representation of mixing state in global climate models.

  10. Rapid Reagentless Detection of M. tuberculosis H37Ra in Respiratory Effluents

    International Nuclear Information System (INIS)

    Adams, K.L.; Steele, P.T.; Bogan, M.J.; Sadler, N.M.; Martin, S.; Martin, A.N.; Frank, M.

    2008-01-01

    Two similar mycobacteria, Mycobacteria tuberculosis H37Ra and Mycobacteria smegmatis are rapidly detected and identified within samples containing a complex background of respiratory effluents using Single Particle Aerosol Mass Spectrometry (SPAMS). M. tuberculosis H37Ra (TBa), an avirulent strain, is used as a surrogate for virulent tuberculosis (TBv); M. smegmatis (MSm) is utilized as a near neighbor confounder for TBa. Bovine lung surfactant and human exhaled breath condensate are used as first-order surrogates for infected human lung expirations from patients with pulmonary tuberculosis. This simulated background sputum is mixed with TBa or MSm and nebulized to produce conglomerate aerosol particles, single particles that contain a bacterium embedded within a background respiratory matrix. Mass spectra of single conglomerate particles exhibit ions associated with both respiratory effluents and mycobacteria. Spectral features distinguishing TBa from MSm in pure and conglomerate particles are shown. SPAMS pattern matching alarm algorithms are able to distinguish TBa containing particles from background matrix and MSm for >50% of the test particles, which is sufficient to enable a high probability of detection and a low false alarm rate if an adequate number of such particles are present. These results indicate the potential usefulness of SPAMS for rapid, reagentless tuberculosis screening

  11. Rapid Reagentless Detection of M. tuberculosis H37Ra in Respiratory Effluents

    Energy Technology Data Exchange (ETDEWEB)

    Adams, K L; Steele, P T; Bogan, M J; Sadler, N M; Martin, S; Martin, A N; Frank, M

    2008-01-29

    Two similar mycobacteria, Mycobacteria tuberculosis H37Ra and Mycobacteria smegmatis are rapidly detected and identified within samples containing a complex background of respiratory effluents using Single Particle Aerosol Mass Spectrometry (SPAMS). M. tuberculosis H37Ra (TBa), an avirulent strain, is used as a surrogate for virulent tuberculosis (TBv); M. smegmatis (MSm) is utilized as a near neighbor confounder for TBa. Bovine lung surfactant and human exhaled breath condensate are used as first-order surrogates for infected human lung expirations from patients with pulmonary tuberculosis. This simulated background sputum is mixed with TBa or MSm and nebulized to produce conglomerate aerosol particles, single particles that contain a bacterium embedded within a background respiratory matrix. Mass spectra of single conglomerate particles exhibit ions associated with both respiratory effluents and mycobacteria. Spectral features distinguishing TBa from MSm in pure and conglomerate particles are shown. SPAMS pattern matching alarm algorithms are able to distinguish TBa containing particles from background matrix and MSm for >50% of the test particles, which is sufficient to enable a high probability of detection and a low false alarm rate if an adequate number of such particles are present. These results indicate the potential usefulness of SPAMS for rapid, reagentless tuberculosis screening.

  12. The ratio of double to single ionization of helium: The relationship of photon and bare charged particle impact ionization

    International Nuclear Information System (INIS)

    Manson, S.T.

    1994-01-01

    In this paper the author derives expressions for the ratio of double to single ionization of helium from its ground state, by both single photons, and charged particle impact. He shows that in the limit of large reduced incident energy T of a charged particle, that the ratio of the double to single ionization cross sections at some energy transfer ΔE is equal to the ratio of photoionization cross sections for a photon of energy hν = ΔE, independent of T. He then goes on to find a relationship for this ionization ratio which is not restricted to some specific energy transfer, and shows that the double to single ionization cross section ratio approaches an asymtotic limit for large enough T

  13. Applications of differential algebra to single-particle dynamics in storage rings

    International Nuclear Information System (INIS)

    Yan, Y.

    1991-09-01

    Recent developments in the use of differential algebra to study single-particle beam dynamics in charged-particle storage rings are the subject of this paper. Chapter 2 gives a brief review of storage rings. The concepts of betatron motion and synchrotron motion, and their associated resonances, are introduced. Also introduced are the concepts of imperfections, such as off-momentum, misalignment, and random and systematic errors, and their associated corrections. The chapter concludes with a discussion of numerical simulation principles and the concept of one-turn periodic maps. In Chapter 3, the discussion becomes more focused with the introduction of differential algebras. The most critical test for differential algebraic mapping techniques -- their application to long-term stability studies -- is discussed in Chapter 4. Chapter 5 presents a discussion of differential algebraic treatment of dispersed betatron motion. The paper concludes in Chapter 6 with a discussion of parameterization of high-order maps

  14. Single-Particle Momentum Distributions of Efimov States in Mixed-Species Systems

    DEFF Research Database (Denmark)

    T. Yamashita, M.; F. Bellotti, F.; Frederico, T.

    2013-01-01

    to derive formulas for the scaling factor of the Efimov spectrum for any mass ratio assuming either that two or three of the two-body subsystems have a bound state at zero energy. We consider the single-particle momentum distribution analytically and numerically and analyse the tail of the momentum......We solve the three-body bound state problem in three dimensions for mass imbalanced systems of two identical bosons and a third particle in the universal limit where the interactions are assumed to be of zero-range. The system displays the Efimov effect and we use the momentum-space wave equation...... distribution to obtain the three-body contact parameter. Our finding demonstrate that the functional form of the three-body contact term depends on the mass ratio and we obtain an analytic expression for this behavior. To exemplify our results, we consider mixtures of Lithium with either two Caesium or Rubium...

  15. Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques

    Science.gov (United States)

    Worringen, A.; Kandler, K.; Benker, N.; Dirsch, T.; Mertes, S.; Schenk, L.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Curtius, J.; Kupiszewski, P.; Weingartner, E.; Vochezer, P.; Schneider, J.; Schmidt, S.; Weinbruch, S.; Ebert, M.

    2015-04-01

    In the present work, three different techniques to separate ice-nucleating particles (INPs) as well as ice particle residuals (IPRs) from non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed-phase clouds and allow after evaporation in the instrument for the analysis of the residuals. The Fast Ice Nucleus Chamber (FINCH) coupled with the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated particles for analysis. The instruments were run during a joint field campaign which took place in January and February 2013 at the High Alpine Research Station Jungfraujoch (Switzerland). INPs and IPRs were analyzed offline by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Online analysis of the size and chemical composition of INP activated in FINCH was performed by laser ablation mass spectrometry. With all three INP/IPR separation techniques high abundances (median 20-70%) of instrumental contamination artifacts were observed (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). After removal of the instrumental contamination particles, silicates, Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types obtained by all three techniques. In addition, considerable amounts (median abundance mostly a few percent) of soluble material (e.g., sea salt, sulfates) were observed. As these soluble particles are often not expected to act as INP/IPR, we consider them as potential measurement artifacts. Minor types of INP/IPR include soot and Pb-bearing particles. The Pb-bearing particles are mainly present as an internal mixture with other