WorldWideScience

Sample records for plasmon-induced fluorescence peak

  1. Junction Plasmon-Induced Molecular Reorientation

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, Patrick Z.; Hu, Dehong; Hess, Wayne P.

    2013-10-17

    Time and frequency dependent intensity variations in sequences of Raman spectra recorded at plasmonic junctions can be assigned to molecular reorientation. This is revealed through Raman trajectories recorded at a nanojunction formed between a silver AFM tip and a corrugated silver surface coated with biphenyl-4,4’-dithiol. Molecular motion is not observed when the tip is retracted and only surface enhancement is operative. In effect, junction plasmon induced molecular reorientation is tracked.

  2. Application of direct peak analysis to energy dispersive x-ray fluorescence spectra

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, K.K.

    1977-07-01

    A modified Covell method for direct peak analysis has been applied to energy dispersive x-ray fluorescence spectra. The method is background independent and is well-suited to computerized data reduction. It provides acceptable precision, minimizes errors from instrumental gain shift, and permits peak overlap correction. Peak overlap errors exhibit both positive and negative nodes as a function of peak separation distance, and are corrected using concentration ratios determined from thin, single-element standards. Peak precisions and overlaps are evaluated as a function of window width to aid in width selection. Least-square polynomial smoothing prior to peak analysis significantly improves peak area precisions without significantly affecting their accuracies.

  3. Active tunable plasmonically induced polarization conversion in the THz regime

    Science.gov (United States)

    Ling, Furi; Yao, Gang; Yao, Jianquan

    2016-01-01

    A plasmon-induced polarization conversion (PIPC) structure based on periodically patterned graphene was demonstrated in the THz regime. By varying the Fermi level of two connected T-shape graphene strips through the electrostatic gating, the peak frequency and the group index in the transparency window can be tuned, which is good agreement with the coupled Lorentz oscillator model. Due to interference between two polarization selective graphene plasmonic resonances coexisting in the planar metamaterial, polarization conversion can be achieved. The linearly polarized THz wave can be converted to elliptically and right circularly polarized THz wave through varying the relaxation time of electrons in graphene. This novel chip-scale active terahertz device promises essential application opportunities in terahertz sensing and terahertz communications. PMID:27734912

  4. Broadband plasmon induced transparency in terahertz metamaterials

    KAUST Repository

    Zhu, Zhihua

    2013-04-25

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. © 2013 IOP Publishing Ltd.

  5. Lasing oscillation condition and group delay control in gain-assisted plasmon-induced transparency

    CERN Document Server

    Deng, Zi-Lan; Wang, He-Zhou; Cheng, S H; Li, Jensen

    2012-01-01

    A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency detunings of the two resonators. The gain coefficient for lasing oscillation condition is analytically shown to vary quadratically with the frequency detuning. In the amplification regime below the lasing threshold, the spectrum implies not only large group delay, but also high transmittance and narrow linewidth. This is in contrast to those in the loss-compensation regime and the passive case in which there always exists a trade-off between the linewidth and the peak transmittance.

  6. Multiple plasmon-induced transparency effects in a multimode-cavity-coupled metal-dielectric-metal waveguide

    Science.gov (United States)

    Chen, Zhiquan; Li, Hongjian; He, Zhihui; Xu, Hui; Zheng, Mingfei; Zhao, Mingzhuo

    2017-09-01

    We numerically and theoretically investigate multiple plasmon-induced transparency (PIT) effects in a multimode-cavity-coupled metal-dielectric-metal (MDM) waveguide system. The introduced multimode coupled-radiating oscillator theory (MC-ROT) gives a clear understanding of multiple PIT effects in the proposed system. Two and three PIT peaks appear in the transmission spectra corresponding to the symmetrical and asymmetrical structures, respectively. Evolution of the PIT peaks can be effectively tuned by adjusting the geometric dimensions and asymmetry of the structure. The ultra-compact plasmonic waveguide structure may have important applications for multichannel filters, optical switches, and other devices in integrated optical circuits.

  7. Giant Surface-Plasmon-Induced Drag Effect in Metal Nanowires

    Science.gov (United States)

    Durach, Maxim; Rusina, Anastasia; Stockman, Mark I.

    2009-10-01

    Here, for the first time we predict a giant surface-plasmon-induced drag-effect rectification (SPIDER), which exists under conditions of the extreme nanoplasmonic confinement. In nanowires, this giant SPIDER generates rectified THz potential differences up to 10 V and extremely strong electric fields up to ˜105-106V/cm. The giant SPIDER is an ultrafast effect whose bandwidth for nanometric wires is ˜20THz. It opens up a new field of ultraintense THz nanooptics with wide potential applications in nanotechnology and nanoscience, including microelectronics, nanoplasmonics, and biomedicine.

  8. Giant surface plasmon induced drag effect (SPIDEr) in metal nanowires

    Science.gov (United States)

    Durach, Maxim; Rusina, Anastasia; Stockman, Mark I.

    2009-08-01

    Here, for the first time we predict a giant surface plasmon-induced drag effect (SPIDEr), which exists under conditions of the extreme nanoplasmonic confinement. Under realistic conditions, in nanowires, this giant SPIDEr generates rectified THz potential differences up to 10 V and extremely strong electric fields up to ~ 105 ~ 106 V/cm. The SPIDEr is an ultrafast effect whose bandwidth for nanometric wires is ~ 20 THz. The giant SPIDEr opens up a new field of ultraintense THz nanooptics with wide potential applications in nanotechnology and nanoscience, including microelectronics, nanoplasmonics, and biomedicine.

  9. Giant increase in the metal-enhanced fluorescence of organic molecules in nanoporous alumina templates and large molecule-specific red/blue-shift of the fluorescence peak.

    Science.gov (United States)

    Sarkar, S; Kanchibotla, B; Nelson, J D; Edwards, J D; Anderson, J; Tepper, G C; Bandyopadhyay, S

    2014-10-08

    The fluorescence of organic fluorophore molecules is enhanced when they are placed in contact with certain metals (Al, Ag, Cu, Au, etc.) whose surface plasmon waves couple into the radiative modes of the molecules and increase the radiative efficiency. Here, we report a hitherto unknown size dependence of this metal-enhanced fluorescence (MEF) effect in the nanoscale. When the molecules are deposited in nanoporous anodic alumina films with exposed aluminum at the bottom of the pores, they form organic nanowires standing on aluminum nanoparticles whose plasmon waves have much larger amplitudes. This increases the MEF strongly, resulting in several orders of magnitude increase in the fluorescence intensity of the organic fluorophores. The increase in intensity shows an inverse superlinear dependence on nanowire diameter because the nanowires also act as plasmonic "waveguides" that concentrate the plasmons and increase the coupling of the plasmons with the radiative modes of the molecules. Furthermore, if the nanoporous template housing the nanowires has built-in electric fields due to space charges, a strong molecule-specific red- or blue-shift is induced in the fluorescence peak owing to a renormalization of the dipole moment of the molecule. This can be exploited to detect minute amounts of target molecules in a mixture using their optical signature (fluorescence) despite the presence of confounding background signals. It can result in a unique new technology for biosensing and chemical sensing.

  10. Dynamically tunable plasmon induced transparency in graphene metamaterials

    Science.gov (United States)

    Fu, Guang-Lai; Zhai, Xiang; Li, Hong-Ju; Xia, Sheng-Xuan; Wang, Ling-Ling

    2017-01-01

    Plasmon induced transparency (PIT) with graphene metamaterials is investigated with the finite-difference time-domain method. Interestingly, the modulation of the PIT transparency window can be achieved by changing not only the gap distance between the two resonators but also the polarization angle of the excitation light. The three-level plasmonic system is employed to clearly explain the formation mechanism of the PIT effect. The analytical results show good consistency with the numerical calculations. Moreover, the PIT resonant wavelength and group delays of incident waves can be dynamically tuned by varying the Fermi energy of the graphene. Our designed graphene nanostructure is promising for the development of compact elements such as tunable sensors, switches and slow-light devices.

  11. Line shapes in a plasmonic waveguide system based on plasmon-induced transparency and its application in nanosensor

    Science.gov (United States)

    He, Jialing; Yang, Shu

    2016-12-01

    A compact plasmonic coupled-resonator structure is investigated using a finite element method, which consists of a ring resonator and a stub coupled with a metal-insulator-metal (MIM) waveguide. Simulation results show that due to the resonant enhancement effect in this system, the plasmon-induced transparency (PIT) occurs and a sharp asymmetric Fano line arise in the transmission spectra by adjusting the parameters of the structure. Meanwhile, the position of the transmission peak can be controlled in any resonance mode by changing the depth of the stub, which is different from the previous researches. The physical features provide a high refractive index sensing with a sensitivity of 1100 nm/RIU and a figure of merit (FOM) of 42550. Moreover, dual resonance peaks are realized by adding an extra ring resonator placed on the stub. The proposed structures may have wide applications in photonic-integrated circuits and the on-chip nanosensors.

  12. Multispectral plasmon-induced transparency in hyperfine terahertz meta-molecules

    Science.gov (United States)

    Yang, Shengyan; Xia, Xiaoxiang; Liu, Zhe; Yiwen, E.; Wang, Yujin; Tang, Chengchun; Li, Wuxia; Li, Junjie; Wang, Li; Gu, Changzhi

    2016-11-01

    We experimentally and theoretically demonstrated an approach to achieve multispectral plasmon-induced transparency (PIT) by utilizing meta-molecules that consist of hyperfine terahertz meta-atoms. The feature size of such hyperfine meta-atoms is 400 nm, which is one order smaller than that of normal terahertz metamaterials. The hyperfine meta-atoms with close eigenfrequencies and narrow resonant responses introduce different metastable energy levels, which makes the multispectral PIT possible. In the triple PIT system, the slow light effect is further confirmed as the effective group delay at three transmission windows can reach 7.3 ps, 7.4 ps and 4.5 ps, respectively. Precisely controllable manipulation of the PIT peaks in such hyperfine meta-molecules was also proven. The new hyperfine planar design is not only suitable for high-integration applications, but also exhibits significant slow light effect, which has great potential in advanced multichannel optical information processing. Moreover, it reveals the possibility to construct hyperfine N-level energy systems by artificial hyperfine plasmonic structures, which brings a significant prospect for applications on miniaturized plasmonic devices.

  13. Pressure measurement using the R fluorescence peaks and 417 cm-1 Raman peak of an anvil in a sapphire-anvil cell

    Science.gov (United States)

    Gao, Rong; Li, Heping

    2012-06-01

    In this study, synthetic sapphire crystals were used as anvils, coupled with a metal gasket, in a Merrill-Bassett-type pressure cell (sapphire-anvil cell (SAC)). Quartz and ruby chips were compressed in the cell and used as pressure calibrators for the SAC. In the sample-anvil interface, the relationship of the frequency shifts of the R1, R2 and 417 cm-1 peaks with pressure was studied. They were constructed as new pressure calibrators. To test the applicability of the newly calibrated SAC, the Raman spectra of dolomite and calcite were measured in situ at room temperature.

  14. Site-selective nanoscale-polymerization of pyrrole on gold nanoparticles via plasmon induced charge separation.

    Science.gov (United States)

    Takahashi, Y; Furukawa, Y; Ishida, T; Yamada, S

    2016-04-28

    We proposed a nanoscale oxidative polymerization method which enables site-selective deposition on the surface of gold nanoparticles (AuNPs) combined with TiO2 by using plasmon induced charge separation (PICS) under visible-to-near infrared (IR) light irradiation. The method also revealed that the anodic site of PICS was located at the surface of AuNPs.

  15. Plasmon-induced optical anisotropy in hybrid graphene-metal nanoparticle systems.

    Science.gov (United States)

    Gilbertson, Adam M; Francescato, Yan; Roschuk, Tyler; Shautsova, Viktoryia; Chen, Yiguo; Sidiropoulos, Themistoklis P H; Hong, Minghui; Giannini, Vincenzo; Maier, Stefan A; Cohen, Lesley F; Oulton, Rupert F

    2015-05-13

    Hybrid plasmonic metal-graphene systems are emerging as a class of optical metamaterials that facilitate strong light-matter interactions and are of potential importance for hot carrier graphene-based light harvesting and active plasmonic applications. Here we use femtosecond pump-probe measurements to study the near-field interaction between graphene and plasmonic gold nanodisk resonators. By selectively probing the plasmon-induced hot carrier dynamics in samples with tailored graphene-gold interfaces, we show that plasmon-induced hot carrier generation in the graphene is dominated by direct photoexcitation with minimal contribution from charge transfer from the gold. The strong near-field interaction manifests as an unexpected and long-lived extrinsic optical anisotropy. The observations are explained by the action of highly localized plasmon-induced hot carriers in the graphene on the subresonant polarizability of the disk resonator. Because localized hot carrier generation in graphene can be exploited to drive electrical currents, plasmonic metal-graphene nanostructures present opportunities for novel hot carrier device concepts.

  16. Independently tunable dual-band plasmonically induced transparency based on hybrid metal-graphene metamaterials at mid-infrared frequencies.

    Science.gov (United States)

    Sun, Chen; Dong, Zhewei; Si, Jiangnan; Deng, Xiaoxu

    2017-01-23

    A tunable dual-band plasmonically induced transparency (PIT) device based on hybrid metal-graphene nanostructures is proposed theoretically and numerically at mid-infrared frequencies, which is composed of two kinds of gold dolmen-like structures with different sizes placed on separate graphene interdigitated finger sets respectively. The coupled Lorentz oscillator model is used to explain the physical mechanism of the PIT effect at multiple frequency domains. The finite-difference time-domain (FDTD) solutions are employed to simulate the characteristics of the hybrid metal-graphene dual-band PIT device. The simulated spectral locations of multiple transparency peaks are separately and dynamically modulated by varying the Fermi energy of corresponding graphene finger set, which is in good accordance with the theoretical analysis. Distinguished from the conventional metallic PIT devices, multiple PIT resonances in the hybrid metal-graphene PIT device are independently modulated by electrostatically changing bias voltages applied on corresponding graphene fingers, which can be widely applied in optical information processing as tunable sensors, switches, and filters.

  17. Novel oscillator model with damping factor for plasmon induced transparency in waveguide systems.

    Science.gov (United States)

    Zhao, Mingzhuo; Li, Hongjian; He, Zhihui; Chen, Zhiquan; Xu, Hui; Zheng, Mingfei

    2017-09-06

    We introduce a novel two-oscillator model with damping factor to describe the plasmon induced transparency (PIT) in a bright-dark model plasmonic waveguide system. The damping factor γ in the model can be calculated from metal conductor damping factor γ c and dielectric damping factor γ d . We investigate the influence of geometry parameters and damping factor γ on transmission spectra as well as slow-light effects in the plasmonic waveguide system. We can find an obvious PIT phenomenon and realize a considerable slow-light effect in the double-cavities system. This work may provide guidance for optical switching and plasmon-based information processing.

  18. Fluorescence peak integration ratio IC:IT as a new potential indicator tracing the compositional changes in chromophoric dissolved organic matter.

    Science.gov (United States)

    Zhou, Yongqiang; Shi, Kun; Zhang, Yunlin; Jeppesen, Erik; Liu, Xiaohan; Zhou, Qichao; Wu, Huawu; Tang, Xiangming; Zhu, Guangwei

    2017-01-01

    The present study demonstrates that the ratio of fluorescence integration of peak C to peak T (IC:IT) can be used as an indicator tracing the compositional dynamics of chromophoric dissolved organic matter (CDOM). CDOM absorption and fluorescence spectroscopy and stable isotope δ(13)C were determined on a seasonal basis in seventeen Chinese inland waters as well as in a series of mixing and photodegradation experiments in the lab. A strong positive linear correlation was recorded between IC:IT and the ratio of terrestrial humic-like C1 to tryptophan-like C4 (C1:C4) derived by parallel factor analysis. The r(2) for the linear fitting between IC:IT and C1:C4 (r(2)=0.80) was notably higher than between C1:C4 and other indices tested, including the ratio of CDOM absorption at 250nm to 365nm, i.e. a(250):a(365) (r(2)=0.09), spectral slope (S275-295) (r(2)=0.26), spectral slope ratio (SR) (r(2)=0.31), the humification index (HIX) (r(2)=0.47), the recent autochthonous biological contribution index (BIX) (r(2)=0.27), and a fluorescence index (FI370) (r(2)=0.07). IC:IT exhibited larger variability than the remaining six indices and a closer correlation with stable isotope δ(13)C than that observed for a(250):a(365), S275-295, SR, FI370, and BIX during field campaigns. Confirming our field observations, significant correlations were recorded between IC:IT and the remaining six indices, and IC:IT also demonstrated notably larger variability than the six other indices during our wastewater addition experiment. Compared with HIX, eutrophic water addition and photobleaching substantially decreased IC:IT but had no pronounced effect on a(250):a(365), S275-297, SR, FI370, and BIX, further suggesting that IC:IT is the most efficient indicator of the CDOM compositional dynamics.

  19. Storage and retrieval of electromagnetic waves with orbital angular momentum via plasmon-induced transparency.

    Science.gov (United States)

    Bai, Zhengyang; Xu, Datang; Huang, Guoxiang

    2017-01-23

    We propose a scheme to realize the storage and retrieval of high-dimensional electromagnetic waves with orbital angular momentum (OAM) via plasmon-induced transparency (PIT) in a metamaterial, which consists of an array of meta-atoms constructed by a metallic structure loaded with two varactors. We show that due to PIT effect the system allows the existence of shape-preserving dark-mode plasmonic polaritons, which are mixture of electromagnetic-wave modes and dark oscillatory modes of the meta-atoms and may carry various OAMs. We demonstrate that the slowdown, storage and retrieval of multi-mode electromagnetic waves with OAMs can be achieved through the active manipulation of a control field. Our work raises the possibility for realizing PIT-based spatial multi-mode memory of electromagnetic waves and is promising for practical application of information processing with large capacity by using room-temperature metamaterials.

  20. Active Multiple Plasmon-Induced Transparency with Graphene Sheets Resonators in Mid-Infrared Frequencies

    Directory of Open Access Journals (Sweden)

    Jicheng Wang

    2016-01-01

    Full Text Available A multiple plasmon-induced transparency (PIT device operated in the mid-infrared region has been proposed. The designed model is comprised of one graphene ribbon as main waveguide and two narrow graphene sheets resonators. The phase coupling between two graphene resonators has been investigated. The multimode PIT resonances have been found in both cases and can be dynamically tuned via varying the chemical potential of graphene resonators without optimizing its geometric parameters. In addition, this structure can get multiple PIT effect by equipping extra two sheets on the symmetric positions of graphene waveguide. The simulation results based on finite element method (FEM are in good agreement with the resonance theory. This work may pave new way for graphene-based thermal plasmonic devices applications.

  1. Tunable ultracompact chip-integrated multichannel filter based on plasmon-induced transparencies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoyu; Chai, Zhen; Lu, Cuicui; Yang, Hong [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China); Hu, Xiaoyong, E-mail: xiaoyonghu@pku.edu.cn, E-mail: qhgong@pku.edu.cn; Gong, Qihuang, E-mail: xiaoyonghu@pku.edu.cn, E-mail: qhgong@pku.edu.cn [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

    2014-06-02

    Nanoscale multichannel filter is realized in plasmonic circuits directly, which consists of four plasmonic nanocavities coupled via a plasmonic waveguide etched in a gold film. The feature device size is only 1.35 μm, which is reduced by five orders of magnitude compared with previous reports. The optical channels are formed by transparency windows of plasmon-induced transparencies. A shift of 45 nm in the central wavelengths of optical channels is obtained when the plasmonic coupled-nanocavities are covered with a 100-nm-thick poly(methyl methacrylate) layer. This work opens up the possibility for the realization of solid quantum chips based on plasmonic circuits.

  2. Theoretical realization of dynamically tunable double plasmonically induced transparency in a graphene-based waveguide structure

    Science.gov (United States)

    Zhang, Zhengren; Fan, Yuancheng; Long, Yang; Yin, Pengfei

    2017-10-01

    A graphene-based waveguide coupled with radiative and subradiant graphene ribbon resonators is proposed to represent the four-level energy diagram in conventional atomic systems and demonstrate a new realization of dynamically tunable double plasmonically induced transparency (DPIT). The radiative resonator is achieved with the help of direct coupling from the graphene waveguide while indirect coupling is relied for the subradiant resonator. By combining the numerical simulation results and the dressed theory, the physical mechanism behind the DPIT is presented in detail. The DPIT phenomenon is derived from the mode splitting caused by the phase-coupled effects. By controlling the Fermi energy level of graphene ribbon, the double transparency windows can be dynamically tuned. The proposed structure may find its application in optical communication or other novel terahertz integrated optical circuits and devices.

  3. Flexible modulation of plasmon-induced transparency in a strongly coupled graphene grating-sheet system.

    Science.gov (United States)

    Luo, Weiwei; Cai, Wei; Xiang, Yinxiao; Wang, Lei; Ren, Mengxin; Zhang, Xinzheng; Xu, Jingjun

    2016-03-21

    General actively tunable near-field plasmon-induced transparency (PIT) systems based on couplings between localized plasmon resonances of graphene nanostructures not only suffer from interantenna separations of smaller than 20 nm, but also lack switchable effect about the transparency window. Here, the performance of an active PIT system based on graphene grating-sheet with near-field coupling distance of more than 100 nm is investigated in mid-infrared. The transparency window in spectrum is analyzed objectively and proved to be more likely stemmed from Aulter-Townes splitting. The proposed system exhibits flexible tunability in slow-light and electro-optical switches, promising for practical active photonic devices.

  4. Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range.

    Science.gov (United States)

    Zhu, Yu; Hu, Xiaoyong; Fu, Yulan; Yang, Hong; Gong, Qihuang

    2013-01-01

    Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm(2) order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials.

  5. Broadband plasmon-induced transparency in terahertz metamaterials via constructive interference of electric and magnetic couplings.

    Science.gov (United States)

    Wan, Mingli; Song, Yueli; Zhang, Liufang; Zhou, Fengqun

    2015-10-19

    Plasmon-induced transparency (PIT) is a result of destructive interference of different plasmonic resonators. Due to the extreme dispersion within the narrow transparency window, PIT metamaterials are utilized to realize slow light and nonlinear effect. However, other applications such as broadband filtering more desire a broad transmission frequency band at the PIT resonance. In this paper, a broadband PIT effect is demonstrated theoretically in a planar terahertz metamaterial, consisting of a U-shaped ring (USR) supporting electric and magnetic dipole modes as the bright resonator and a cut wire pair (CWP) possessing planar electric quadrupole and magnetic dipole modes as the dark resonator. The dark resonant modes of the CWP can be excited simultaneously via near-field by both the electric and magnetic dipole modes of the USR. When the electric as well as magnetic excitation pathways constructively interact with each other, the enhanced near-field coupling between bright and dark resonators gives rise to an ultra-broad transparency window across a frequency range greater than 0.61 THz in the transmittance spectrum.

  6. Plasmon-induced photoluminescence immunoassay for tuberculosis monitoring using gold-nanoparticle-decorated graphene.

    Science.gov (United States)

    Lee, Jaewook; Kim, Jeonghyo; Ahmed, Syed Rahin; Zhou, Hongjian; Kim, Jong-Man; Lee, Jaebeom

    2014-12-10

    Metal-nanoparticle-functionalized graphene, in particular, graphene sheets containing Au nanoparticles (Au NPs), have generated considerable interest because of their unique optical and electrical characteristics. In this study, we successfully produced graphene sheets decorated with Au NPs (AuGrp) using phytochemicals as reducing agents. During this reaction, Au ions intercalated into the layered graphene flakes and were then reduced into NPs, exfoliating the graphene sheets. The physicochemical properties of the AuGrp nanocomposites were characterized, and the exfoliation process was investigated using a molecular dynamics simulation of Au NPs between graphene sheets. Our proposed technique is advantageous because the phytochemicals are mild reducing agents that preserve the graphene structure during exfoliation and NP decoration. The dispersity of the NPs on the graphene sheets was drastically improved due to the use of metal-ion intercalation. Moreover, the electrical conductivity was 6-30 times higher than that of bare graphene and reduced graphene oxide. Using antibody (Ab) modified AuGrp sheets and quantum dots, a plasmonic-induced photoluminescence immunoassay of tuberculosis (TB) antigen (aG) CFP-10 was demonstrated for a potential application of these materials. The enhancement of photoluminescence (PL) response was monitored depending on the various TB aG concentrations from 5.1 pg/mL to 51 μg/mL, and the detection limit for CFP-10 was 4.5 pg/mL. Furthermore, the selectivity was demonstrated with Ag85 as the other TB aG, and PL enhancement was not observed in this case. Therefore, AuGrp-based immunoassay showed the potential for biosensor application.

  7. Optical Control of Fluorescence through Plasmonic Eigenmode Extinction

    CERN Document Server

    Xu, Xiaoying; Li, Quanshui; Zhang, Zhili; Ivanov, Ilia N; Li, Yuan; Wang, Wenbin; Gu, Baohua; Zhang, Zhenyu; Hsueh, Chun-Hway; Snijders, Paul C; Seal, Katyayani

    2015-01-01

    We introduce the concept of optical control of the fluorescence yield of CdSe quantum dots through plasmon-induced structural changes in random semicontinuous nanostructured gold films. We demonstrate that the wavelength- and polarization dependent coupling between quantum dots and the semicontinuous films, and thus the fluorescent emission spectrum, can be controlled and significantly increased through the optical extinction of a selective band of eigenmodes in the films. This optical method of effecting controlled changes in the metal nanostructure allows for versatile functionality in a single sample and opens a pathway to in situ control over the fluorescence spectrum.

  8. PeakWorks

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-30

    The PeakWorks software is designed to assist in the quantitative analysis of atom probe tomography (APT) generated mass spectra. Specifically, through an interactive user interface, mass peaks can be identified automatically (defined by a threshold) and/or identified manually. The software then provides a means to assign specific elemental isotopes (including more than one) to each peak. The software also provides a means for the user to choose background subtraction of each peak based on background fitting functions, the choice of which is left to the users discretion. Peak ranging (the mass range over which peaks are integrated) is also automated allowing the user to chose a quantitative range (e.g. full-widthhalf- maximum). The software then integrates all identified peaks, providing a background-subtracted composition, which also includes the deconvolution of peaks (i.e. those peaks that happen to have overlapping isotopic masses). The software is also able to output a 'range file' that can be used in other software packages, such as within IVAS. A range file lists the peak identities, the mass range of each identified peak, and a color code for the peak. The software is also able to generate 'dummy' peak ranges within an outputted range file that can be used within IVAS to provide a means for background subtracted proximity histogram analysis.

  9. Paniek over Peak Food

    NARCIS (Netherlands)

    Koning, N.B.J.

    2015-01-01

    Het kon niet uitblijven. De groei van de voedselproductie stagneert en na Peak Oil dreigt nu Peak Food. Onzin, vindt Niek Koning, die zogenaamde peak is een van de toppen in een langjarige golfbeweging op de landbouwmarkten. Toch zijn er genoeg redenen om je zorgen te maken over de wereldvoedselvoor

  10. Are Bragg Peaks Gaussian?

    Science.gov (United States)

    Hammouda, Boualem

    2014-01-01

    It is common practice to assume that Bragg scattering peaks have Gaussian shape. The Gaussian shape function is used to perform most instrumental smearing corrections. Using Monte Carlo ray tracing simulation, the resolution of a realistic small-angle neutron scattering (SANS) instrument is generated reliably. Including a single-crystal sample with large d-spacing, Bragg peaks are produced. Bragg peaks contain contributions from the resolution function and from spread in the sample structure. Results show that Bragg peaks are Gaussian in the resolution-limited condition (with negligible sample spread) while this is not the case when spread in the sample structure is non-negligible. When sample spread contributes, the exponentially modified Gaussian function is a better account of the Bragg peak shape. This function is characterized by a non-zero third moment (skewness) which makes Bragg peaks asymmetric for broad neutron wavelength spreads. PMID:26601025

  11. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  12. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  13. The central peak revisited

    Energy Technology Data Exchange (ETDEWEB)

    Shirane, G.

    1995-10-27

    The central peak in SrTiO{sub 3} was first observed by Riste and his collaborators in 1971. This was one of the key discoveries leading to an understanding of the dynamics of phase transitions. The most recent discovery of two length scales in SrTiO{sub 3} motivated a reinvestigation of the soft phonon and associated central peak by neutron scattering. These recent experiments shed new light on the nature of the central peak. It is now well established to be strongly sample dependent and it originates from defects in bulk crystals.

  14. Pikes Peak, Colorado

    Science.gov (United States)

    Brunstein, Craig; Quesenberry, Carol; Davis, John; Jackson, Gene; Scott, Glenn R.; D'Erchia, Terry D.; Swibas, Ed; Carter, Lorna; McKinney, Kevin; Cole, Jim

    2006-01-01

    For 200 years, Pikes Peak has been a symbol of America's Western Frontier--a beacon that drew prospectors during the great 1859-60 Gold Rush to the 'Pikes Peak country,' the scenic destination for hundreds of thousands of visitors each year, and an enduring source of pride for cities in the region, the State of Colorado, and the Nation. November 2006 marks the 200th anniversary of the Zebulon M. Pike expedition's first sighting of what has become one of the world's most famous mountains--Pikes Peak. In the decades following that sighting, Pikes Peak became symbolic of America's Western Frontier, embodying the spirit of Native Americans, early explorers, trappers, and traders who traversed the vast uncharted wilderness of the Western Great Plains and the Southern Rocky Mountains. High-quality printed paper copies of this poster are available at no cost from Information Services, U.S. Geological Survey (1-888-ASK-USGS).

  15. Peak Oil, Peak Coal and Climate Change

    Science.gov (United States)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  16. Peak of Achievement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s first inland research station on the highest peak of Antarctic progresses smoothly China will complete the construction of its first inland Antarctic research station at Dome A,the highest polar icecap peak at 4,093 meters above sea level,next year,according to a south pole scientist involved in the project. "The preparatory work for the new sta-

  17. Correlation-Peak Imaging

    Science.gov (United States)

    Ziegler, A.; Metzler, A.; Köckenberger, W.; Izquierdo, M.; Komor, E.; Haase, A.; Décorps, M.; von Kienlin, M.

    1996-08-01

    Identification and quantitation in conventional1H spectroscopic imagingin vivois often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, β-glucose, glutamine/glutamate, lysine, and arginine.

  18. Semiconductor plasmon induced upconversion enhancement in mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell nanocomposites.

    Science.gov (United States)

    Zhou, Donglei; Li, Dongyu; Zhou, Xiangyu; Xu, Wen; Chen, Xu; Liu, Dali; Zhu, Yongsheng; Song, Hongwei

    2017-09-18

    The ability to modulate the intensity of electromagnetic field by semiconductor plasmon nanoparticles is becoming attractive owing to its unique doping induced local surface plasmon resonance (LSPR) effect different from metals. Herein, we synthesized the mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell composites and experimentally and theoretically studied the semiconductor plasmon induced upconversion (UC) enhancement, and obtained 30 folds UC enhancement compared to that of SiO2@Y2O3:Yb(3+),Er(3+) composites. The UC enhancement was induced by the synthetic effect: amplification of excitation field and the increase of resonance energy transfer (ET) rate from Yb(3+) ions to Er(3+) ions. The experimental results were analyzed in the light of FDTD calculations confirming the effect of amplification of excitation field. In addition, UCL spectra, UC enhancement and dynamics dependent on concentration (Yb(3+)/Er(3+) ions) were investigated and found that the resonance energy transfer (ET) rate from Yb(3+) ions to Er(3+) ions increased ~25% in the effect of LSPR waves. Finally, power dependence of fingerprint identification was successfully performed based on the mCu2-xS@SiO2@Y2O3:Yb(3+),Er(3+) core-shell composites, the color of which can change from green to orange with excitation power increasing. Our work opens up a new concept to design and fabricate the upconversion core-shell structure based on semiconductor plasmon nanoparticles (NPs) and provides applications for upconversion nanocrystals (UCNPs) and semiconductor plasmon NPs in photonics.

  19. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  20. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  1. Impact Crater with Peak

    Science.gov (United States)

    2002-01-01

    (Released 14 June 2002) The Science This THEMIS visible image shows a classic example of a martian impact crater with a central peak. Central peaks are common in large, fresh craters on both Mars and the Moon. This peak formed during the extremely high-energy impact cratering event. In many martian craters the central peak has been either eroded or buried by later sedimentary processes, so the presence of a peak in this crater indicates that the crater is relatively young and has experienced little degradation. Observations of large craters on the Earth and the Moon, as well as computer modeling of the impact process, show that the central peak contains material brought from deep beneath the surface. The material exposed in these peaks will provide an excellent opportunity to study the composition of the martian interior using THEMIS multi-spectral infrared observations. The ejecta material around the crater can is well preserved, again indicating relatively little modification of this landform since its initial creation. The inner walls of this approximately 18 km diameter crater show complex slumping that likely occurred during the impact event. Since that time there has been some downslope movement of material to form the small chutes and gullies that can be seen on the inner crater wall. Small (50-100 m) mega-ripples composed of mobile material can be seen on the floor of the crater. Much of this material may have come from the walls of the crater itself, or may have been blown into the crater by the wind. The Story When a meteor smacked into the surface of Mars with extremely high energy, pow! Not only did it punch an 11-mile-wide crater in the smoother terrain, it created a central peak in the middle of the crater. This peak forms kind of on the 'rebound.' You can see this same effect if you drop a single drop of milk into a glass of milk. With craters, in the heat and fury of the impact, some of the land material can even liquefy. Central peaks like the one

  2. Origin of bimodal fluorescence enhancement factors of Chlorobaculum tepidum reaction centers on silver island films.

    Science.gov (United States)

    Maćkowski, Sebastian; Czechowski, Nikodem; Ashraf, Khuram U; Szalkowski, Marcin; Lokstein, Heiko; Cogdell, Richard J; Kowalska, Dorota

    2016-08-01

    We focus on the spectral dependence of plasmon-induced enhancement of fluorescence of Chlorobaculum tepidum reaction centers. When deposited on silver island film, they exhibit up to a 60-fold increase in fluorescence. The dependence of enhancement factors on the excitation wavelength is not correlated with the absorption spectrum of the plasmonic structure. In particular, the presence of one (or multiple) trimers of the Fenna-Matthews-Olson (FMO) protein reveals itself in bimodal distribution of enhancement factors for the excitation at 589 nm, the wavelength corresponding to bacteriochlorophyll absorption of FMO and the core of the RC. We conclude that the structure of multichromophoric complexes can substantially affect the impact of plasmonic excitations, which is important in the context of assembling functional biohybrid systems.

  3. Geyser Peak Cabernet Sauvignon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>年份:2000产地:美国加州Sonoma County售价:$196 Geyser Peak(盖世峰)成立于1880年,是美国军有的过百岁葡萄酒庄。可惜美国酿制葡萄酒的技术在近三四十年才有突破,历史再悠久也没有太多帮助近二十年Geyser Peak就努力改进,希望迎头赶上其它加州新秀的水平,1989年,他们就聘请了澳洲Penfolds酒庄的酿酒师Daryl Groom,让旗下出品多了一份澳洲式的"霎眼娇"风格。2003年,Geyser Peak更在International Wine & Spirit Competition赢得"最佳美国葡萄酒生产商"大奖。

  4. Peak mass and dynamical friction

    CERN Document Server

    Del Popolo, A

    1995-01-01

    We show how the results given by several authors relatively to the mass of a density peak are changed when small scale substructure induced by dynamical friction are taken into account. The peak mass obtained is compared to the result of Peacock \\& Heavens (1990) and to the peak mass when dynamical friction is absent to show how these effects conspire to reduce the mass accreted by the peak.

  5. Peak capacity in unidimensional chromatography.

    Science.gov (United States)

    Neue, Uwe Dieter

    2008-03-14

    The currently existing knowledge about peak capacity in unidimensional separations is reviewed. The majority of the paper is dedicated to reversed-phase gradient chromatography, covering specific techniques as well as the subject of peak compression. Other sections deal with peak capacity in isocratic chromatography, size-exclusion chromatography and ion-exchange chromatography. An important topic is the limitation of the separation power and the meaning of the concept of peak capacity for real applications.

  6. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  7. [Fluorescence spectroscopy study of synthetic food colors].

    Science.gov (United States)

    Chen, Guo-qing; Wu, Ya-min; Wang, Jun; Zhu, Tuo; Gao, Shu-mei

    2009-09-01

    According to the characteristic of synthetic food colors molecule and the relationship between fluorescence and molecular structure, and through analyzing, it has been concluded that synthetic food colors is fluorescent material. By using SP-2558 multifunctional spectral measuring system, the three-dimensional fluorescence spectra of ponceau 4R, amaranth, tartrazine, sunset yellow and brilliant blue were measured. The results show that ponceau 4R excited by light at the wavelength of 330-430 nm can generate a strong fluorescence at the 621 nm peak wavelength with its best excitation wavelength being 376 nm, amaranth excited by light at the wavelength of 300-440 nm can generate a strong fluorescence at the 643 nm peak wavelength with its best excitation wavelength being 370 nm, tartrazine excited by light at the wavelength of 280-380 nm can generate a strong fluorescence at the 565 nm peak wavelength with its best excitation wavelength being 315 nm, sunset yellow excited by light with wavelength of 310-410 nm can generate a strong fluorescence at the 592 nm peak wavelength with its best excitation wavelength being 348 nm, and brilliant blue excited by light at the wavelength of 320-390 nm can generate a strong fluorescence at the 456 nm peak wavelength with its best excitation wavelength being 350 nm. Moreover, the fluorescence spectra of the five kinds of synthetic food colors were discussed. These results can provide helps for testing of food colors and food safety.

  8. PEAK SHAVING CONSIDERING STREAMFLOW UNCERTAINTIES

    African Journals Online (AJOL)

    user

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of ... Fuel cost at a conventional hydro plant is nil. On the other hand, the ... s(k) = spill at the hydro plant in period k. I(k) = loss due to ...

  9. How to use your peak flow meter

    Science.gov (United States)

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... If your airways are narrowed and blocked due to asthma, your peak flow values drop. You can ...

  10. Doppler peaks from active perturbations

    CERN Document Server

    Magueijo, J; Coulson, D; Ferreira, P; Magueijo, Joao; Albrecht, Andreas; Coulson, David; Ferreira, Pedro

    1995-01-01

    We examine how the qualitative structure of the Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy depends on the fundamental nature of the perturbations which produced them. The formalism of Hu and Sugiyama is extended to treat models with cosmic defects. We discuss how perturbations can be ``active'' or ``passive'' and ``incoherent'' or ``coherent'', and show how causality and scale invariance play rather different roles in these various cases. We find that the existence of secondary Doppler peaks and the rough placing of the primary peak unambiguously reflect these basic properties.

  11. Make peak flow a habit!

    Science.gov (United States)

    ... asthma - peak flow References Durrani SR, Busse WW. Management of asthma in adolescents and adults. In: Adkinson NF Jr, Bochner BS, Burks AW, et al, eds. Middleton's Allergy Principles and Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

  12. Peak Oil and other threatening peaks-Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian, E-mail: marian@radetzki.bi [Lulea University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

  13. Peak Oil and other threatening peaks. Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian [Luleaa University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth. (author)

  14. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  15. Gallstone identification by fluorescence spectroscopy

    Science.gov (United States)

    Pradhan, Asima; Laxmi, B. V.; Jena, Sidhartha S.; Khulbe, P. K.; Bist, Hari D.; Agarwal, Asha

    1998-04-01

    Gallstones have been classified as being cholesterol type and pigment type. The classification is important for diet control of the patient to avoid recurrence of the stone. Spectroscopy is a sensitive technique to determine the composition of the gallstone both in-vitro and in-vivo. this work deals with the fluorescence spectroscopy of gallstone. For fluorescence spectroscopic studies of gallstone, samples were excited with 5 mw of 488 nm line of argon-ion laser and spectra were recorded with a SPEX 1877E triplemate attached with a cooled PMT and DM3000R data acquisition system. Fluorescence spectra from pure cholesterol and bilirubin were also recorded for comparison. Different types of gallstones: mixed, cholesterol, pigment type were studied. All spectra exhibited a very broad band, 500 to 800 nm and sometimes two bands, depending on type of stone. Pure cholesterol shows three prominent fluorescence peaks at 513, 550, 583 nm along with two peaks at approximately 568 and 586 nm. Pure bilirubin shows prominent peak at 628 nm, without any Raman line. From fluorescence spectra different types of stones are identified. Different gallstones studied show a mixture of cholesterol and bilirubin types and the ratio of the two varies from one sample type to another.

  16. Significance Tests for Periodogram Peaks

    CERN Document Server

    Frescura, F A M; Frank, B S

    2007-01-01

    We discuss methods currently in use for determining the significance of peaks in the periodograms of time series. We discuss some general methods for constructing significance tests, false alarm probability functions, and the role played in these by independent random variables and by empirical and theoretical cumulative distribution functions. We also discuss the concept of "independent frequencies" in periodogram analysis. We propose a practical method for estimating the significance of periodogram peaks, applicable to all time series irrespective of the spacing of the data. This method, based on Monte Carlo simulations, produces significance tests that are tailor-made for any given astronomical time series.

  17. Hubbert's Peak -- A Physicist's View

    Science.gov (United States)

    McDonald, Richard

    2011-04-01

    Oil, as used in agriculture and transportation, is the lifeblood of modern society. It is finite in quantity and will someday be exhausted. In 1956, Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Bartlett extended this work in publications and lectures on the finite nature of oil and its production peak and depletion. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. Central to these analyses are estimates of total ``oil in place'' obtained from engineering studies of oil reservoirs as this quantity determines the area under the Hubbert's Peak. Knowing the production history and the total oil in place allows us to make estimates of reserves, and therefore future oil availability. We will then examine reserves data for various countries, in particular OPEC countries, and see if these data tell us anything about the future availability of oil. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

  18. Discriminate Modelling of Peak and Off-Peak Motorway Capacity

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2013-02-01

    Full Text Available Traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Without question traffic flow is an essential quantitative parameter that is used in planning, designs and roadway improvements.  Road capacity is significant because it is an important indicator of road performance and can point road managers in the right road maintenance and traffic management direction. In this paper four direct empirical capacity measurement methods have been considered. To test the efficacy of each method, data for peak period, off-peak and transition to peak have been used. The headway and the volume methods lack predictive capability and are suitable only for current assessment of flow rates.  The product limit method is weak in its predictive capability in view of the arbitrariness in the selection of the capacity value. It is also an extreme value method; hence not all volume data can be used with this method. The fundamental diagram method has good predictive capability and furnishes capacity values consistent with the standard of the facility. Unlike other methods, it does not rely on bottleneck conditions to deliver the capacity value.  The paper concluded that each method is uniquely suited to prevailing conditions and can be so employed.

  19. Fluorescence Studies of Selected 2-Alkylaminopyrimidines

    Directory of Open Access Journals (Sweden)

    B. K. Low

    2004-06-01

    Full Text Available The reactions of 2-chloropyrimidine with methylamine, ethylamine and piperidine gave the corresponding 2-N-methylamino-, 2-N-ethylamino- and 2N- piperidinopyrimidines, respectively. The fluorescence properties of these alkylamino derivatives in chloroform, ethyl acetate, carbon tetrachloride, acetone, ether, ethanol and methanol were studied. All the alkylamino derivatives showed the highest fluorescence intensity in polar protic solvents; thus 2-N-methylaminopyrimidine (highest fluorescence intensity at 377 nm when excited at 282 nm and 2-N-ethylaminopyrimidine (highest fluorescence intensity at 375 nm, when excited at 286 nm showed the highest fluorescence in methanol. In ethanol, 2-N-piperidinopyrimidine showed a fluorescence peak at 403 nm when excited at 360 nm and in chloroform it fluoresced at 392 nm when excited at 356 nm.

  20. Longitudinal peak detected Schottky spectrum

    CERN Document Server

    Shaposhnikova, E

    2009-01-01

    The "peak detected Schottky" spectrum is a diagnostic used since the late seventies for beam observation in the SPS and now already applied to the LHC. This tool was always believed, however without proof, to give a good picture of the particle distribution in synchrotron frequencies similar to the longitudinal Schottky spectrum of unbunched beam for revolution frequencies.In this paper an analysis of this measurement technique is presented both in a general form and for the particular realisation in the SPS. In addition the limitations of the present experimental set-up are discussed together with possible improvements. The analysis shows that for an optimised experimental set-up the spectrum of the peak detected signal is very close to the synchrotron frequency distribution inside the bunch - much closer than that given by the traditional longitudinal bunched-beam Schottky spectrum.

  1. Fluorescent microspheres

    Science.gov (United States)

    Rembaum, A.

    1978-01-01

    Latex particles with attached antibodies have potential biochemical and environmental applications. Human red blood cells and lymphocytes have been labeled with fluorescent microspheres by either direct or indirect immunological technique. Immunolatex spheres can also be used for detecting and localizing specific cell surface receptors. Hormones and toxins may also be bondable.

  2. Intense fluorescence of Au 20

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chongqi; Harbich, Wolfgang; Sementa, Luca; Ghiringhelli, Luca; Aprá, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Brune, Harald

    2017-08-21

    Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. We show that their fluorescence is an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ =739.2 nm (1.68 eV) for Au20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the HOMO-LUMO diabatic bandgap of the cluster. The cluster shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au20 has only one stable isomer (tetrahedral), therefore our sample is mono-disperse in cluster size and conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorptionand predict both main absorption peaks and intrinsic fluorescence in good agreement with experiment.

  3. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  4. Further insights into metal-DOM interaction: consideration of both fluorescent and non-fluorescent substances.

    Directory of Open Access Journals (Sweden)

    Huacheng Xu

    Full Text Available Information on metal binding with fluorescent substances has been widely studied. By contrast, information on metal binding with non-fluorescent substances remains lacking despite the dominance of these substances in aquatic systems. In this study, the metal binding properties of both fluorescent and non-fluorescent substances were investigated by using metal titration combined with two-dimensional correlation spectroscopy (2D-COS analysis. The organic matters in the eutrophic algae-rich lake, including natural organic matters (NOM and algae-induced extracellular polymeric substances (EPS, both contained fluorescent and non-fluorescent substances. The peaks in the one-dimensional spectra strongly overlapped, while 2D-COS can decompose the overlapped peaks and thus enhanced the spectral resolution. Moreover, 2D FTIR COS demonstrated that the binding susceptibility of organic ligands in both NOM and algal EPS matrices followed the order: 3400>1380>1650 cm-1, indicative the significant contribution of non-fluorescent ligands in metal binding. The modified Stern-Volmer equation also revealed a substantial metal binding potential for the non-fluorescent substances (logKM: 3.57∼4.92. As for the effects of organic ligands on metal binding, EPS was characterized with higher binding ability than NOM for both fluorescent and non-fluorescent ligands. Algae-induced EPS and the non-fluorescent substances in eutrophic algae-rich lakes should not be overlooked because of their high metal binding potential.

  5. Fluorescence detection of esophageal neoplasia

    Science.gov (United States)

    Borisova, E.; Vladimirov, B.; Avramov, L.

    2008-06-01

    White-light endoscopy is well-established and wide used modality. However, despite the many technological advances that have been occurred, conventional endoscopy is suboptimal and usually detects advanced stage lesions. The limitations of standard endoscopy initiate development of spectroscopic techniques, additional to standard endoscopic equipment. One of the most sensitive approaches is fluorescence spectroscopy of gastrointestinal mucosa for neoplasia detection. In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. Excitation source has max of emission at 405 nm and light is delivered by the standard light guide of the endoscopic equipment. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to reabsorption of blood. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of 5-ALA/PpIX only in abnormal sites Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

  6. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  7. Peak Detection Using Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Omar Daoud

    2014-07-01

    Full Text Available A new work based-wavelet transform is designed to o vercome one of the main drawbacks that found in the present new technologies. Orthogonal Frequency Divi sion Multiplexing (OFDMis proposed in the literature to enhance the multimedia resolution. Ho wever, the high peak power (PAPR values will obstr uct such achievements. Therefore, a new proposition is found in this work, making use of the wavelet transforms methods, and it is divided into three ma in stages; de-noising stage, thresholding stage and then the replacement stage. In order to check the system stages validity; a mat hematical model has been built and its checked afte r using a MATLAB simulation. A simulated bit error ra te (BER achievement will be compared with our previously published work, where an enhancement fro m 8×10 -1 to be 5×10 -1 is achieved. Moreover, these results will be compared to the work found in the l iterature, where we have accomplished around 27% PAPR extra reduction. As a result, the BER performance has been improved for the same bandwidth occupancy. Moreover and due to the de-noise stage, the verification rate ha s been improved to reach 81%. This is in addition t o the noise immunity enhancement.

  8. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus...... complement the well-studied notion of single-peaked preferences. We mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting...

  9. 27 CFR 9.140 - Atlas Peak.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Atlas Peak. 9.140 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.140 Atlas Peak. (a) Name. The name of the viticultural area described in this section is “Atlas Peak.”...

  10. On the fluorescence of C60 at room temperature

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The fluorescence properties of C 60 in different organic solvents have been investigated at room temperature. Three fluorescence emission centers are discovered and ascribed to different aggregations of C 60 in solvent. A series of blue fluorescence peaks centered at 440 nm derive from C 60 nanoparticles; a distinctive yellow-green fluorescence band in 575 nm region arises from the aggregates of C 60 nanoparticles; a more informative salmon fluorescence band around 700 nm originates from C 60 microcrystals. And the distinct configurations of C 60 aggregations are closely associated with the characteristic interaction between C 60 and solvent molecules.

  11. On the trail of double peak hydrographs

    Science.gov (United States)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceased. Double peak hydrographs may occur for various reasons. They can occur (i) in large catchments when lag times in tributary responses are large, (ii) in urban catchments where the first peak is often caused by direct surface runoff on impervious land cover, and the delayed peak to slower subsurface flow, and (iii) in non-urban catchments, where the first and the delayed discharge peaks are explained by different runoff mechanisms (e.g. overland flow, subsurface flow and/or deep groundwater flow) that have different response times. Here we focus on the third case, as a formal description of the different hydrological mechanisms explaining these complex hydrological dynamics across catchments with diverse physiographic characteristics is still needed. Based on a review of studies documenting double peak events we have established a formal classification of catchments presenting double peak events based on their regolith structure (geological substratum and/or its weathered products). We describe the different hydrological mechanisms that trigger these complex hydrological dynamics across each catchment type. We then use hydrometric time series of precipitation, runoff, soil moisture and groundwater levels collected in the Weierbach (0.46 km2) headwater catchment (Luxembourg) to better understand double peak hydrograph generation. Specifically, we aim to find out (1) if the generation of a double peak hydrograph is a threshold process, (2) if the hysteretic relationships between storage and discharge are consistent during single and double peak hydrographs, and (3) if different functional landscape units (the hillslopes

  12. Fluorescence characterization of clinically-important bacteria.

    Directory of Open Access Journals (Sweden)

    Lewis R Dartnell

    Full Text Available Healthcare-associated infections (HCAI/HAI represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of

  13. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  14. Ruby fluorescence pressure scale: Revisited

    Science.gov (United States)

    Liu, Lei; Bi, Yan; Xu, Ji-An

    2013-05-01

    Effect of non-hydrostatic stress on X-ray diffraction in a diamond anvil cell (DAC) is studied. The pressure gradient in the sample chamber leads to the broadening of the diffraction peaks, which increase with the hkl index of the crystal. It is found that the difference between the determined d-spacing compressive ratio d/d0 and the real d-spacing compressive ratio dr/d0 is determined by the yield stress of the pressure transmitting media (if used) and the shear modulus of the sample. On the basis of the corrected experiment data of Mao et al. (MXB86), which was used to calibrate the most widely used ruby fluorescence scale, a new relationship of ruby fluorescence pressure scale is corrected, i.e., P = (1904/9.827)[(1 + Δλ/λ0)9.827-1].

  15. [A peak recognition algorithm designed for chromatographic peaks of transformer oil].

    Science.gov (United States)

    Ou, Linjun; Cao, Jian

    2014-09-01

    In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

  16. Mechanism of fluorescent cocoon sex identification for silkworms Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By using silkworms,Bombyx mori, fluorescent cocoon sex identification (FCSI) as an experimental material, direct fluorescence spectrometry of the cocoon surface indicates that the fluorescent color of silkworm cocoons is made up of two peaks of yellow and blue-purple fluorescence emission. The fluorescent difference between male and female cocoons is attributed to the differential absorption of yellow fluorescent substances by the midgut tissue of 5th instar female silkworms. Thin layer chromatography (TLC) and fluorescent spectra indicate that blue-purple fluorescent substances are composed of at least five blue-purple fluorescent pigments, and yellow fluorescent substances are made up of at least three. UV spectra and AlCl3 color reaction show that the three fluorescent yellow pigments are flavonoids or their glycosides. Silkworm FCSI is due to selective absorption or accumulation of the yellow fluorescent pigments by the posterior midgut cells of female 5th instar larvae. The cells of the FCSI silkworm midgut, especially the cylinder intestinal cells of the posterior midgut have a component which is a yellow fluorescent pigment-specific binding protein that may be vigorously expressed in the 5th instar larvae.

  17. Laser induced fluorescence of dental caries

    Science.gov (United States)

    Albin, S.; Byvik, C. E.; Buoncristiani, A. M.

    1988-01-01

    Significant differences between the optical spectra taken from sound regions of teeth and carious regions have been observed. These differences appear both in absorption and in laser induced fluorescence spectra. Excitation by the 488 nm line of an argon ion laser beam showed a peak in the emission intensity around 553 nm for the sound dental material while the emission peak from the carious region was red-shifted by approximately 40 nm. The relative absorption of carious region was significantly higher at 488 nm; however its fluorescence intensity peak was lower by an order of magnitude compared to the sound tooth. Implications of these results for a safe, reliable and early detection of dental caries are discussed.

  18. Laser induced fluorescence of dental caries

    Science.gov (United States)

    Albin, S.; Byvik, C. E.; Buoncristiani, A. M.

    1988-01-01

    Significant differences between the optical spectra taken from sound regions of teeth and carious regions have been observed. These differences appear both in absorption and in laser induced fluorescence spectra. Excitation by the 488 nm line of an argon ion laser beam showed a peak in the emission intensity around 553 nm for the sound dental material while the emission peak from the carious region was red-shifted by approximately 40 nm. The relative absorption of carious region was significantly higher at 488 nm; however its fluorescence intensity peak was lower by an order of magnitude compared to the sound tooth. Implications of these results for a safe, reliable and early detection of dental caries are discussed.

  19. Fundamentals of fluorescence and fluorescence microscopy.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    This chapter discusses the fundamental physics of fluorescence. The application of fluorescence to microscopy represents an important transition in the development of microscopy, particularly as it applies to biology. It enables quantitating the amounts of specific molecules within a cell, determining whether molecules are complexing on a molecular level, measuring changes in ionic concentrations within cells and organelles, and measuring molecular dynamics. This chapter also discusses the issues important to quantitative measurement of fluorescence and focuses on four of quantitative measurements of fluorescence--boxcar-gated detection, streak cameras, photon correlation, and phase modulation. Although quantitative measurement presents many pitfalls to the beginner, it also presents significant opportunities to one skilled in the art. This chapter also examines how fluorescence is measured in the steady state and time domain and how fluorescence is applied in the modern epifluorescence microscope.

  20. Do dark matter halos explain lensing peaks?

    Science.gov (United States)

    Zorrilla Matilla, José Manuel; Haiman, Zoltán; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-10-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with S /N >1 (where S /N is the ratio of the peak height to the r.m.s. shape noise), we find ≈50 % fewer counts for peaks near S /N =0 and significantly higher counts in the negative S /N tail. Adding shape noise reduces the differences to within 20% for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the {Ωm,σ8} are ≈30 % larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with 2 important cosmological information in N-body data, as shown in previous studies, but Camelus constrains cosmology almost exclusively from high significance peaks (S /N >3 ). Our results confirm the importance of using a cosmology-dependent covariance with at least a 14% improvement in parameter constraints. We identified the covariance estimation as the main driver behind differences in inference, and suggest possible ways to make Camelus even more useful as a highly accurate peak count emulator.

  1. Electrocapillary instability of magnetic fluid peak

    CERN Document Server

    Mkrtchyan, Levon; Dikansky, Yuri

    2013-01-01

    The paper presents an experimental study of the capillary electrostatic instability occurring under effect of a constant electric field on a magnetic fluid individual peak. The peaks under study occur at disintegration of a magnetic fluid layer applied on a flat electrode surface under effect of a perpendicular magnetic field. The electrocapillary instability shows itself as an emission of charged drops jets from the peak point in direction of the opposing electrode. The charged drops emission repeats periodically and results in the peak shape pulsations. It is shown that a magnetic field affects the electrocapillary instability occurrence regularities and can stimulate its development. The critical electric and magnetic field strengths at which the instability occurs have been measured; their dependence on the peak size is shown. The hysteresis in the system has been studied; it consists in that the charged drops emission stops at a lesser electric (or magnetic) field strength than that of the initial occurr...

  2. Multiphoton fluorescence spectra and lifetimes of biliverdins and their protein-associated complex

    Science.gov (United States)

    Huang, Chin-Jie; Wu, Cheng-Ham; Liu, Tzu-Ming

    2012-03-01

    To investigate whether endogenous biliverdins can serve as a fluorescence metabolic marker in cancer diagnosis, we measured their multiphoton fluorescence spectra and lifetimes with femtosecond Cr:forsterite laser. Excited at 1230nm, the two-photon fluorescence of biliverdins peaks around 670nm. The corresponding lifetime (catabolism in human cells or tissues.

  3. Fluorescence from Varnishes for Oil Paintings under N2 Laser Excitation

    Science.gov (United States)

    Miyoshi, Tadaki

    1987-05-01

    The fluorescence spectra of varnish films have been measured as a function of the storage time. The varnishes used were made from natural resins (copal, mastic and dammar), synthetic resin and beeswax. Peak wavelengths of the fluorescence shifted to longer wavelengths with long-time storage. The effect of light on the fluorescence spectrum was found to be small.

  4. The Origin of Weak Lensing Convergence Peaks

    CERN Document Server

    Liu, Jia

    2016-01-01

    Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $\\Omega_m$ and $\\sigma_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational data from the 154 deg$^2$ Canada-France-Hawaii Telescope Lensing Survey. We found that while high peaks (with height $\\kappa$ >3.5 $\\sigma_\\kappa$, where $\\sigma_\\kappa$ is the r.m.s. of the convergence $\\kappa$) are typically due to one single massive halo of ~$10^{15}M_\\odot$, low peaks ($\\kappa$ ~ their virial radii), compared with ~0.25 virial radii for halos linked with high peaks, hinting that low peaks are more immune to baryonic processes whose impact is confined to the inner regions of the dark matter halos. Our fi...

  5. Fluorescence of fullerene derivatives at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S.K.; Shiu, L.L.; Chien, K.M.; Luh, T.Y.; Lin, T.I. (National Taiwan Univ., Taipei (Taiwan, Province of China))

    1995-01-05

    The absorption and fluorescence spectral properties of fullerene (C[sub 60]) and its derivatives C[sub 60]C[sub 4]H[sub 6], C[sub 60]C[sub 5]H[sub 6], C[sub 60]CHCO[sub 2]Et, and C[sub 60]NCO[sub 2]Et at room temperature were investigated. Breaking the structural symmetry of C[sub 60] results in enhancing the fluorescence quantum yield 2-3-fold in some derivatives. Thus, the room temperature fluorescence of fullerene compounds could be detected more rapidly. New absorption bands and altered fluorescence spectra were observed in the derivatives. The Stokes' shifts of the derivatives are small, about 4-5 nm, compared to 68 nm for the parent compound. The time-resolved fluorescence decay study indicates that all four fullerene derivatives have a single fluorescence lifetime of ca. 1.2-1.4 as, which is about the same as that for C[sub 60] (ca. 1.3 ns). Aliphatic solvents have little influence on the absorption or fluorescence spectral profile except on the extinction coefficient whereas aromatic and polar solvents strongly interact with the fullerene derivatives, causing a peak broadening effect. 31 refs., 7 figs., 3 tabs.

  6. Reviews in fluorescence 2010

    CERN Document Server

    Geddes, Chris D

    2011-01-01

    ""Reviews in Fluorescence 2010"", the seventh volume of the book serial from Springer, serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence and closely related disciplines. It summarizes the year's progress in fluorescence and its applications, with authoritative analytical reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. ""Reviews in Fluorescence"" offers an essential reference material for any lab working in the fluoresc

  7. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  8. Peak load arrangements : Assessment of Nordel guidelines

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

  9. The effect of temperature of fluorescence: an animal study

    Science.gov (United States)

    Walsh, Alex; Masters, Bart; Jansen, Duco; Welch, A. J.; Mahadevan-Jansen, Anita

    2010-02-01

    The effect of temperature on the fluorescence of enucleated porcine eyes and rat skin was studied. The fluorescence peak intensity was found to decrease as the tissue temperature increased. A dual-excitation, fiber-based system was used to collect fluorescence and diffuse-reflectance spectra from the samples. A thermal camera was used to determine the temperature of the tissue at the time of fluorescence measurement. The samples were mounted in a saline bath and measurements were made as the tissue temperature was increased from -20°C to 70°C. Results indicate that temperature affects several fluorescence spectra characteristics. The peak height decreased as temperature increased. At temperatures above 60°C, the peak position shifted to lower wavelengths. Heating and cooling experiments of the rat skin demonstrate the recovery of the loss in fluorescence. The diffuse reflectance spectra indicated a change in optical properties past 60°C, but prior to the denaturation temperature for collagen at 57°C, no change in optical properties was observed. Results suggest that the decrease in fluorescence is both a property of fluorescence and a result of altering optical properties.

  10. Bioaerosol Analysis by Online Fluorescence Detection and Fluorescence Microscopy

    Science.gov (United States)

    Huffman, Alex; Pöhlker, Christopher; Treutlein, Bärbel; Pöschl, Ulrich

    2010-05-01

    Primary biological aerosol particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany, we used an ultraviolet aerodynamic particle sizer (UV-APS) to measure fluorescent biological aerosol particles (FBAPs), which can be regarded as viable bioaerosol particles representing a lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (concentration of coarse FBAPs was 3x10-2 cm-3, corresponding to 4% of total coarse particle number [1]. The mean mass concentration of FBAPs was 1 ?g m-3, corresponding to 20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters, though a pronounced peak at 3 μm was essentially always observed. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle with maximum intensity during early/mid-morning. FBAP peaks around 1.5 μm, 5 μm, and 13 μm were also observed, but less pronounced and less frequent. These may be explained by single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of PBAPs in aerosol filter samples. To our knowledge, however, this is the first study reporting continuous online measurements of bioaerosol particles over several months, a range of characteristic size distribution patterns, and a persistent bioaerosol peak at 3 μm. The measurement results confirm that PBAPs account for a

  11. Bayesian peak picking for NMR spectra.

    Science.gov (United States)

    Cheng, Yichen; Gao, Xin; Liang, Faming

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein-DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  12. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... not supported by your browser. Home Osteoporosis Women Osteoporosis: Peak Bone Mass in Women Publication available in: ... drug products. NIH Pub. No. 15-7891 NIH Osteoporosis and Related Bone Diseases ~ National Resource Center 2 ...

  13. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  14. Amplification of postwildfire peak flow by debris

    Science.gov (United States)

    Kean, J. W.; McGuire, L. A.; Rengers, F. K.; Smith, J. B.; Staley, D. M.

    2016-08-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  15. Peak Vegetation Growth 2000 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2000 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  16. Peak Vegetation Growth 2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2004 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  17. Peak Vegetation Growth 1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1999 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  18. Peak Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  19. Peak Vegetation Growth 1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1994 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  20. Peak Vegetation Growth 1995 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1995 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  1. Peak Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  2. Peak Vegetation Growth 2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2001 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  3. Peak Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  4. Peak Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  5. Peak Vegetation Growth 1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1990 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  6. Peak Vegetation Growth 1996 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1996 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  7. Peak Vegetation Growth 2005 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2005 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  8. Tectonics, Climate and Earth's highest peaks

    Science.gov (United States)

    Robl, Jörg; Prasicek, Günther; Hergarten, Stefan

    2016-04-01

    Prominent peaks characterized by high relief and steep slopes are among the most spectacular morphological features on Earth. In collisional orogens they result from the interplay of tectonically driven crustal thickening and climatically induced destruction of overthickened crust by erosional surface processes. The glacial buzz-saw hypothesis proposes a superior status of climate in limiting mountain relief and peak altitude due to glacial erosion. It implies that peak altitude declines with duration of glacial occupation, i.e., towards high latitudes. This is in strong contrast with high peaks existing in high latitude mountain ranges (e.g. Mt. St. Elias range) and the idea of peak uplift due to isostatic compensation of spatially variable erosional unloading an over-thickened orogenic crust. In this study we investigate landscape dissection, crustal thickness and vertical strain rates in tectonically active mountain ranges to evaluate the influence of erosion on (latitudinal) variations in peak altitude. We analyze the spatial distribution of serval thousand prominent peaks on Earth extracted from the global ETOPO1 digital elevation model with a novel numerical tool. We compare this dataset to crustal thickness, thickening rate (vertical strain rate) and mean elevation. We use the ratios of mean elevation to peak elevation (landscape dissection) and peak elevation to crustal thickness (long-term impact of erosion on crustal thickness) as indicators for the influence of erosional surface processes on peak uplift and the vertical strain rate as a proxy for the mechanical state of the orogen. Our analysis reveals that crustal thickness and peak elevation correlate well in orogens that have reached a mechanically limited state (vertical strain rate near zero) where plate convergence is already balanced by lateral extrusion and gravitational collapse and plateaus are formed. On the Tibetan Plateau crustal thickness serves to predict peak elevation up to an altitude

  9. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

  10. Do dark matter halos explain lensing peaks?

    CERN Document Server

    Matilla, José Manuel Zorrilla; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-01-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with $\\mathcal{S/N}>1$ (where $\\mathcal{S/N}$ is the ratio of the peak height to the r.m.s. shape noise), we find $\\approx 50\\%$ fewer counts for peaks near $\\mathcal{S/N}=0$ and significantly higher counts in the negative $\\mathcal{S/N}$ tail. Adding shape noise reduces the differences to within $20\\%$ for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the $\\{\\Omega_m, \\sigma_8\\}$ are $\\approx 30\\%$ larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with $23)$. Our results confirm the importance of using a cosmology-dependent covariance with at least a 14\\% improveme...

  11. Fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    Hink, M.A.; Verveer, P.J.

    2015-01-01

    Fluorescence fluctuation spectroscopy techniques allow the quantification of fluorescent molecules present at the nanomolar concentration level. After a brief introduction to the technique, this chapter presents a protocol including background information in order to measure and quantify the molecul

  12. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

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

  13. Use of laser fluorescence in dental caries diagnosis: a fluorescence x biomolecular vibrational spectroscopic comparative study.

    Science.gov (United States)

    Carvalho, Fabíola Bastos de; Barbosa, Artur Felipe Santos; Zanin, Fátima Antonia Aparecida; Brugnera Júnior, Aldo; Silveira Júnior, Landulfo; Pinheiro, Antonio Luiz Barbosa

    2013-01-01

    The aim of this work was to verify the existence of correlation between Raman spectroscopy readings of phosphate apatite (~960 cm-1), fluoridated apatite (~575 cm-1) and organic matrix (~1450 cm-1) levels and Diagnodent® readings at different stages of dental caries in extracted human teeth. The mean peak value of fluorescence in the carious area was recorded and teeth were divided in enamel caries, dentin caries and sound dental structure. After fluorescence readings, Raman spectroscopy was carried out on the same sites. The results showed significant difference (ANOVA, pcaries. There was significant negative correlation (pcaries. It may be concluded that the higher the fluorescence detected by Diagnodent the lower the peaks of phosphate apatite and fluoridated apatite. As the early diagnosis of caries is directly related to the identification of changes in the inorganic tooth components, Raman spectroscopy was more sensitive to variations of these components than Diagnodent.

  14. The PEAK experience in South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    The PEAK Institute was developed to provide a linkage for formal (schoolteachers) and nonformal educators (extension agents) with agricultural scientists of Clemson University`s South Carolina Agricultural Experiment Station System. The goal of the Institute was to enable teams of educators and researchers to develop and provide PEAK science and math learning experiences related to relevant agricultural and environmental issues of local communities for both classroom and 4-H Club experiences. The Peak Institute was conducted through a twenty day residential Institute held in June for middle school and high school teachers who were teamed with an Extension agent from their community. These educators participated in hands-on, minds-on sessions conducted by agricultural researchers and Clemson University Cooperative Extension specialists. Participants were given the opportunity to see frontier science being conducted by scientists from a variety of agricultural laboratories.

  15. Fluorescent silver nanoparticles via exploding wire technique

    Indian Academy of Sciences (India)

    Alqudami Abdullah; S Annapoorni

    2005-11-01

    Aqueous solution containing spherical silver nanoparticles of 20–80 nm size have been generated using a newly developed novel electro-exploding wire (EEW) technique where thin silver wires have been exploded in double distilled water. Structural properties of the resulted nanoparticles have been studied by means of X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The absorption spectrum of the aqueous solution of silver nanoparticles showed the appearance of a broad surface plasmon resonance (SPR) peak centered at a wavelength of 390 nm. The theoretically generated SPR peak seems to be in good agreement with the experimental one. Strong green fluorescence emission was observed from the water-suspended silver nanoparticles excited with light of wavelengths 340, 360 and 390 nm. The fluorescence of silver nanoparticles could be due to the excitation of the surface plasmon coherent electronic motion with the small size effect and the surface effect considerations.

  16. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  17. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  18. Real estate price peaks: a comparative overview

    CERN Document Server

    Röhner, B M

    2006-01-01

    First, we emphasize that the real estate price peaks which are currently under way in many industrialized countries (one important exception is Japan) share many of the characteristics of previous historical price peaks. In particular, we show that: (i) In the present episode real price increases are, at least for now, of the same order of magnitude as in previous episodes, typically of the order of 80 percent to 100 percent. (ii) Historically, price peaks turned out to be symmetrical with respect to the peak; soft landing, i.e. an upgoing phase followed by a plateau, has rarely (if ever) been observed. (iii) The inflated demand is mainly boosted by investors and high-income buyers. (iv) In the present as well as in previous episodes, the main engines in the upgoing phase have been the hot markets which developed in major cities such as London, Los Angeles, New York, Paris, San Francisco or Sydney. In our conclusion, we propose a prediction for real estate prices in the West of the United States over the peri...

  19. Spanish Peaks, Sangre de Cristo Range, Colorado

    Science.gov (United States)

    2002-01-01

    The Spanish Peaks, on the eastern flank of the Sangre de Cristo range, abruptly rise 7,000 feet above the western Great Plains. Settlers, treasure hunters, trappers, gold and silver miners have long sighted on these prominent landmarks along the Taos branch of the Santa Fe trail. Well before the westward migration, the mountains figured in the legends and history of the Ute, Apache, Comanche, and earlier tribes. 'Las Cumbres Espanolas' are also mentioned in chronicles of exploration by Spaniards including Ulibarri in 1706 and later by de Anza, who eventually founded San Francisco (California). This exceptional view (STS108-720-32), captured by the crew of Space Shuttle mission STS108, portrays the Spanish Peaks in the context of the southern Rocky Mountains. Uplift of the Sangre de Cristo began about 75 million years ago and produced the long north-trending ridges of faulted and folded rock to the west of the paired peaks. After uplift had ceased (26 to 22 million years ago), the large masses of igneous rock (granite, granodiorite, syenodiorite) that form the Peaks were emplaced (Penn, 1995-2001). East and West Spanish Peaks are 'stocks'-bodies of molten rock that intruded sedimentary layers, cooled and solidified, and were later exposed by erosion. East Peak (E), at 12,708 ft is almost circular and is about 5 1/2 miles long by 3 miles wide, while West Peak (W), at 13,623 ft is roughly 2 3/4 miles long by 1 3/4 miles wide. Great dikes-long stone walls-radiate outward from the mountains like spokes of a wheel, a prominent one forms a broad arc northeast of East Spanish Peak. As the molten rock rose, it forced its way into vertical cracks and joints in the sedimentary strata; the less resistant material was then eroded away, leaving walls of hard rock from 1 foot to 100 feet wide, up to 100 feet high, and as long as 14 miles. Dikes trending almost east-west are also common in the region. For more information visit: Sangres.com: The Spanish Peaks (accessed January 16

  20. Two-photon bioimaging utilizing supercontinuum light generated by a high-peak-power picosecond semiconductor laser source.

    Science.gov (United States)

    Yokoyama, Hiroyuki; Tsubokawa, Hiroshi; Guo, Hengchang; Shikata, Jun-ichi; Sato, Ki-ichi; Takashima, Keijiro; Kashiwagi, Kaori; Saito, Naoaki; Taniguchi, Hirokazu; Ito, Hiromasa

    2007-01-01

    We developed a novel scheme for two-photon fluorescence bioimaging. We generated supercontinuum (SC) light at wavelengths of 600 to 1200 nm with 774-nm light pulses from a compact turn-key semiconductor laser picosecond light pulse source that we developed. The supercontinuum light was sliced at around 1030- and 920-nm wavelengths and was amplified to kW-peak-power level using laboratory-made low-nonlinear-effects optical fiber amplifiers. We successfully demonstrated two-photon fluorescence bioimaging of mouse brain neurons containing green fluorescent protein (GFP).

  1. [Study on the characters of phytoplankton chlorophyll fluorescence excitation spectra based on fourth-derivative].

    Science.gov (United States)

    Lu, Lu; Su, Rong-Guo; Wang, Xiu-Lin; Zhu, Chen-Jian

    2007-11-01

    Chlorophyll fluorescence excitation spectra of six phytoplankton species, belonging to Bacillariophyta and Dinophyta, were dealt by fourth-derivative analysis with the Matlab program. The results show that between 350 nm and 550 nm six fluorescence peaks were found in the fourth-derivative spectra, which are representatives of non-pigments, chlorophylls and carotenoides respectively. The method makes Bacillariophyta and Dinophyta more distinguishable when the fourth-derivative spectra are compared with the chlorophyll fluorescence excitation spectra. It can be used not only to discriminate the two groups of algaes, but also to reduce the effect of noise. The fluorescence peaks in the fourth-derivative spectra are proved to be stable.

  2. Predicting VO2peak from Submaximal- and Peak Exercise Models: The HUNT 3 Fitness Study, Norway.

    Directory of Open Access Journals (Sweden)

    Henrik Loe

    Full Text Available Peak oxygen uptake (VO2peak is seldom assessed in health care settings although being inversely linked to cardiovascular risk and all-cause mortality. The aim of this study was to develop VO2peak prediction models for men and women based on directly measured VO2peak from a large healthy population.VO2peak prediction models based on submaximal- and peak performance treadmill work were derived from multiple regression analysis. 4637 healthy men and women aged 20-90 years were included. Data splitting was used to generate validation and cross-validation samples.The accuracy for the peak performance models were 10.5% (SEE = 4.63 mL⋅kg(-1⋅min(-1 and 11.5% (SEE = 4.11 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 75% and 72% of the variance explained. For the submaximal performance models accuracy were 14.1% (SEE = 6.24 mL⋅kg(-1⋅min(-1 and 14.4% (SEE = 5.17 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 55% and 56% of the variance explained. The validation and cross-validation samples displayed SEE and variance explained in agreement with the total sample. Cross-classification between measured and predicted VO2peak accurately classified 91% of the participants within the correct or nearest quintile of measured VO2peak.Judicious use of the exercise prediction models presented in this study offers valuable information in providing a fairly accurate assessment of VO2peak, which may be beneficial for risk stratification in health care settings.

  3. Effect of gear ratio on peak power and time to peak power in BMX cyclists.

    Science.gov (United States)

    Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

    2017-03-01

    The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders' bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14) = 6.448; p = .010) and peak torque (F(2,14) = 4.777; p = .026), but no significant difference was found for time to peak power (F(2,14) = 0.200; p = .821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658 ± 221 W, compared to 1436 ± 129 W and 1380 ± 56 W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in -0.01 s and a 45/16 in 0.22 s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.

  4. The Doppler peaks from a generic defect

    CERN Document Server

    Magueijo, J

    1996-01-01

    We investigate which of the exotic Doppler peak features found for textures and cosmic strings are generic novelties pertaining to defects. We find that the ``out of phase'' texture signature is an accident. Generic defects, when they generate a secondary peak structure similar to inflation, apply to it an additive shift. It is not necessary for this shift to be ``out of phase''. We also show which factors are responsible for the absence of secondary oscillations found for cosmic strings. Within this general analysis we finally consider the conditions under which topological defects and inflation can be confused. It is argued that only \\Omega=1 inflation and a defect with a horizon size coherence length have a chance to be confused. Any other inflationary or defect model always differ distinctly. (To appear in the proceedings of the XXXIth Moriond meeting, ``Microwave Background Anisotropies'')

  5. Solar Cycle 24: is the peak coming?

    CERN Document Server

    Sello, Stefano

    2012-01-01

    Solar cycle activity forecasting, mainly its magnitude and timing, is an essential issue for numerous scientific and technological applications: in fact, during an active solar period, many strong eruptions occur on the Sun with increasing frequency, such as flares, coronal mass ejections, high velocity solar wind photons and particles, which can severely affect the Earth's ionosphere and the geomagnetic field, with impacts on the low atmosphere. Thus it is very important to develop reliable solar cycle prediction methods for the incoming solar activity. The current solar cycle 24 appeared unusual from many points of view: an unusually extended minimum period, and a global low activity compared to those of the previous three or four cycles. Currently, there are many different evidences that the peak in the northern hemisphere already occurred at 2011.6 but not yet in the southern hemisphere. In this brief note we update the peak prediction and its timing, based on the most recent observations.

  6. Peak oil, food systems, and public health.

    Science.gov (United States)

    Neff, Roni A; Parker, Cindy L; Kirschenmann, Frederick L; Tinch, Jennifer; Lawrence, Robert S

    2011-09-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all.

  7. Excursion set peaks: the role of shear

    CERN Document Server

    Castorina, Emanuele; Hahn, Oliver; Sheth, Ravi K

    2016-01-01

    Recent analytical work on the modelling of dark halo abundances and clustering has demonstrated the advantages of combining the excursion set approach with peaks theory. We extend these ideas and introduce a model of excursion set peaks that incorporates the role of initial tidal effects or shear in determining the gravitational collapse of dark haloes. The model -- in which the critical density threshold for collapse depends on the tidal influences acting on protohaloes -- is well motivated from ellipsoidal collapse arguments and is also simple enough to be analytically tractable. We show that the predictions of this model are in very good agreement with measurements of the halo mass function and traditional scale dependent halo bias in N-body simulations across a wide range of masses and redshift. The presence of shear in the collapse threshold means that halo bias is naturally predicted to be nonlocal, and that protohalo densities at fixed mass are naturally predicted to have Lognormal-like distributions. ...

  8. Binding of dicamba to soluble and bound extracellular polymeric substances (EPS) from aerobic activated sludge: a fluorescence quenching study.

    Science.gov (United States)

    Pan, Xiangliang; Liu, Jing; Zhang, Daoyong; Chen, Xi; Song, Wenjuan; Wu, Fengchang

    2010-05-15

    Binding of dicamba to soluble EPS (SEPS) and bound EPS (BEPS) from aerobic activated sludge was investigated using fluorescence spectroscopy. Two protein-like fluorescence peaks (peak A with Ex/Em=225 nm/342-344 nm and peak B with Ex/Em=275/340-344 nm) were identified in SEPS and BEPS. Humic-like fluorescence peak C (Ex/Em=270-275 nm/450-460 nm) was only found in BEPS. Fluorescence of the peaks A and B for SEPS and peak A for BEPS were markedly quenched by dicamba at all temperatures whereas fluorescence of peaks B and C for BEPS was quenched only at 298 K. A dynamic process dominated the fluorescence quenching of peak A of both SEPS and BEPS. Fluorescence quenching of peak B and C was governed a static process. The effective quenching constants (logK(a)) were 4.725-5.293 for protein-like fluorophores of SEPS and 4.23-5.190 for protein-like fluorophores of BEPS, respectively. LogK(a) for humic-like substances was 3.85. Generally, SEPS had greater binding capacity for dicamba than BEPS, and protein-like substances bound dicamba more strongly than humic-like substances. Binding of dicamba to SEPS and BEPS was spontaneous and exothermic. Electrostatic force and hydrophobic interaction forces play a crucial role in binding of dicamba to EPS.

  9. Reducing Peak Power in Automated Weapon Laying

    Science.gov (United States)

    2016-02-01

    The values used are determined based on a number of factors including available power, maximum motor speed , maximum safe slewing speeds , peak...METHODS, ASSUMPTIONS, AND PROCEDURES Conventions and Variable Definitions Before describing the formulas to solve the aforementioned problems, it is...These two formulas are set equal to each other in equation 9 and then solved for t2 in equation 10. Note that the negative value of α2 results in a

  10. Hanford Site peak gust wind speeds

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.

    1998-09-29

    Peak gust wind data collected at the Hanford Site since 1945 are analyzed to estimate maximum wind speeds for use in structural design. The results are compared with design wind speeds proposed for the Hanford Site. These comparisons indicate that design wind speeds contained in a January 1998 advisory changing DOE-STD-1020-94 are excessive for the Hanford Site and that the design wind speeds in effect prior to the changes are still appropriate for the Hanford Site.

  11. METing SUSY on the Z peak

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, G.; Bernabeu, J.; Vives, O. [Universitat de Valencia, Departament de Fisica Teorica, Burjassot (Spain); Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain); Mitsou, V.A.; Romero, E. [Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain)

    2016-02-15

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E{sub T}{sup miss} > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m{sub g} or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  12. Pyrene-based dual-mode fluorescence switches and logic gates that function in solution and film.

    Science.gov (United States)

    Zhou, Weidong; Li, Yongjun; Li, Yuliang; Liu, Huibiao; Wang, Shu; Li, Cuihong; Yuan, Mingjian; Liu, Xiaofeng; Zhu, Daoben

    2006-07-17

    A dual-mode fluorescence switch controlled by external inputs such as protons and metal ions is described, and each state corresponds to a specific fluorescent emission peak. Based on the reversible changes of the fluorescence emission of the switch responding to different external stimuli, the corresponding integrated logic gates and communication networks have been constructed in solid film or in solution.

  13. Will peak oil accelerate carbon dioxide emissions?

    Science.gov (United States)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  14. Measurements of extrinsic fluorescence in Intralipid and polystyrene microspheres

    Science.gov (United States)

    Du Le, Vinh Nguyen; Nie, Zhaojun; Hayward, Joseph E.; Farrell, Thomas J.; Fang, Qiyin

    2014-01-01

    The fluorescence of Intralipid and polystyrene microspheres with sphere diameter of 1 µm at a representative lipid and microsphere concentration for simulation of mucosal tissue scattering has not been a subject of extensive experimental study. In order to elucidate the quantitative relationship between lipid and microsphere concentration and the respective fluorescent intensity, the extrinsic fluorescence spectra between 360 nm and 650 nm (step size of 5 nm) were measured at different lipid concentrations (from 0.25% to 5%) and different microsphere concentrations (0.00364, 0.0073, 0.0131 spheres per cubic micrometer) using laser excitation at 355 nm with pulse energy of 2.8 µJ. Current findings indicated that Intralipid has a broadband emission between 360 and 650 nm with a primary peak at 500 nm and a secondary peak at 450 nm while polystyrene microspheres have a single peak at 500 nm. In addition, for similar scattering properties the fluorescence of Intralipid solutions is approximately three-fold stronger than that of the microsphere solutions. Furthermore, Intralipid phantoms with lipid concentrations ~2% (simulating the bottom layer of mucosa) produce up to seven times stronger fluorescent emission than phantoms with lipid concentration ~0.25% (simulating the top layer of mucosa). The fluoresence decays of Intralipid and microsphere solutions were also recorded for estimation of fluorescence lifetime. PMID:25136497

  15. Fluorescence spectrum analysis of atherosclerotic plaque using doxycycline.

    Science.gov (United States)

    Miyagi, M; Nakajima, H; Katoh, T; Usui, M; Amemiya, T; Nagai, Y; Ibukiyama, C

    1999-05-01

    Using doxycycline (DOXY), fluorescence spectrum analysis was performed on arteriosclerotic lesions, and the efficacy of this method was examined in basic and clinical studies. In the basic study, DOXY 50 mg was administered intravenously to arteriosclerotic rabbits, and the thoracoabdominal aorta removed. Fluorescence spectral analysis was performed on each specimen, and the fluorescence spectral pattern, peak intensity and degree of intimal hypertrophy were studied. In the clinical study, DOXY 200 mg was administered intravenously to 6 human subjects with stable angina and coronary arterial stenosis of greater than 90%, and coronary angiography, coronary angioscopy and fluorescence spectral analysis were performed. DOXY accumulation in the arteriosclerotic intima of rabbit aortae was confirmed. The fluorescence spectrum was monomodal, peaking at around 532 nm. In the noncalcification group, significant correlation was observed between peak intensity and arteriosclerotic intimal thickness. Using DOXY as a fluorescent marker, it was possible to assess the level of arteriosclerotic intimal hypertrophy. Clinically, it was possible to obtain the DOXY spectrum of the coronary arteries.

  16. Effect of Rainfall on Traffic Stream Characteristics during Peak and Non-Peak Periods

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2012-01-01

    Full Text Available This paper examined the effect of rainfall on traffic stream behaviour during  peak and non-peak periods on a basic highway section. Data on this section which is located on the J5 was collected for four months during which 99 rainfall events occurred. The traffic consisted of 75.80% cars, 10.23% motorcycles, 3.51% trucks and 10.46%  of other vehicles. Traffic was observed for both rain and no-rain conditions and the data was analysed to see the effect of the rain. The results showed decreases in the speed as the rain intensity increased. Similarly, the traffic flow rates decreased as the rain intensity increased. This trend was observed for both peak and non-peak periods and for both directions. It is concluded that the effect of rain during peak period could have more serious consequences on the traffic flow than during non-peak periods because of the higher flow rates and the constrained nature of the flow. Consequently, capacity degradations up to 30% during peak periods would require resources to be employed to manage the traffic.

  17. Fabrication of fluorescent chitosan-containing microcapsules

    Directory of Open Access Journals (Sweden)

    Zhang R.

    2013-08-01

    Full Text Available Intense emission peaks of Eu(DBM3Phen (DBM and Phen are dibenzoylmethane and 1,10-phenanthroline, respectively in the microcapsules containing molecules of quaternary ammonium chitosan (QACS and sodium alginate are observed. The microcapsules are assembled by using CaCO3 particles as template cores by the layer-by-layer (LbL technique. Observation of microcapsules by the fluorescence mode and the transmission mode in the confocal laser scanning microscopy shows that the microcapsules are intact after core decomposition. Fluorescence under ultraviolet irradiation comes directly from the Eu(DBM3Phen. Homogeneous assembly of Eu(DBM3Phen can be deduced due to the homogeneous fluorescence of the microcapsules in the fluorescence micrographs. The microcapsules show adherence to solid substrates due to large quantities of hydroxyl groups of QACS. AFM measurements of dried hollow microcapsules with only 4 bilayers of (CS/SA fabricated with Eu(DBM3Phen show the intact shell with a thickness of 3.0 nm. Regarding the biocompatible natural polysaccharides and the intense fluorescence emission, the microcapsules in this work might be of great importance in potential application in drug delivery and bioassay.

  18. Red fluorescent biofilm: the thick, the old, and the cariogenic

    Directory of Open Access Journals (Sweden)

    Catherine M.C. Volgenant

    2016-04-01

    Full Text Available Background: Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective: The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design: The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results: From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions: The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence.

  19. Red fluorescent biofilm: the thick, the old, and the cariogenic

    Science.gov (United States)

    Volgenant, Catherine M.C.; Hoogenkamp, Michel A.; Buijs, Mark J.; Zaura, Egija; ten Cate, Jacob (Bob) M.; van der Veen, Monique H.

    2016-01-01

    Background Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF) by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM) and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm) and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence. PMID:27060056

  20. Fluorescence antibunching microscopy

    CERN Document Server

    Schwartz, Osip

    2011-01-01

    Breaking the diffraction limit in microscopy by utilizing quantum properties of light has been the goal of intense research in the recent years. We propose a quantum superresolution technique based on non-classical emission statistics of fluorescent markers, routinely used as contrast labels for bio-imaging. The technique can be readily implemented using standard fluorescence microscopy equipment.

  1. Fluorescence of atopic allergens

    NARCIS (Netherlands)

    Berrens, L.

    1967-01-01

    Purified atopic allergens have been found to emit flue fluorescence upon irradiation with ultraviolet light of 365 mμ wavelength. The maximum of fluorescence is in the region 445–490 mμ and the intensity is of the same order of magnitude for different atopic allergens. Synthetic model compounds, inc

  2. Fluorescent Lamp Replacement Study

    Science.gov (United States)

    2017-07-01

    Light-emitting diode, LED, lighting, fluorescent, waste reduction, energy conservation, net zero , mercury 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...Center (ATC) to assess the benefits of converting fluorescent tube lighting to light-emitting diode (LED) technology. The report documents the waste ...1-15 SECTION 2. SUBTESTS 2.1 HAZARDOUS WASTE REDUCTION

  3. LEDs for fluorescence microscopy

    NARCIS (Netherlands)

    Young, I.T.; Garini, Y.; Dietrich, H.R.C.; Van Oel, W.; Liqui Lung, G.

    2004-01-01

    Traditional light sources for fluorescence microscopy have been mercury lamps, xenon lamps, and lasers. These sources have been essential in the development of fluorescence microscopy but each can have serious disadvantages: lack of near monochromaticity, heat generation, cost, lifetime of the light

  4. Characterisation of estuarine intertidal macroalgae by laser-induced fluorescence

    DEFF Research Database (Denmark)

    Gameiro, Carla; Utkin, Andrei B.; Sousa Dias Cartaxana, Paulo Jorge

    2015-01-01

    spectra were determined by differences in the main fluorescing pigments: phycoerythrin, phycocyanin and chlorophyll a (Chl a). In the green and brown macroalgae groups, the relative significance of the two emission maxima seems to be related to the thickness of the photosynthetic layer. In thick...... macroalgae, like Codium tomentosum or Fucus vesiculosus, the contribution of the far-red emission fluorescence peak was more significant, most probably due to re-absorption of the emitted red Chl a fluorescence within the dense photosynthetic layer. Similarly, an increase in the number of layers of the thin...

  5. U(IV) fluorescence spectroscopy. A new speciation tool

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, Susanne; Brendler, Vinzenz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2017-06-01

    We combined absorption and fluorescence spectroscopy to study the speciation of U(IV) in solution in concentrations down to 10{sup -6} M uranium. With our time-resolved laser-induced fluorescence setup we could determine the fluorescence decay time of U(IV) in perchloric as well as in chloric acid with 2.6 ± 0.3 ns at room temperature and 148.4 ± 6.5 ns at liquid nitrogen temperature. For the U(IV) sulfate system, we observed a bathochromic shift and a peak shape modification in the fluorescence spectra with increasing sulfate concentration in solution. Thus, the potential of U(IV) fluorescence for speciation analysis could be proven.

  6. Stink Bug Feeding Induces Fluorescence in Developing Cotton Bolls

    Directory of Open Access Journals (Sweden)

    Toews Michael D

    2011-08-01

    Full Text Available Abstract Background Stink bugs (Hemiptera: Pentatomidae comprise a critically important insect pest complex affecting 12 major crops worldwide including cotton. In the US, stink bug damage to developing cotton bolls causes boll abscission, lint staining, reduced fiber quality, and reduced yields with estimated losses ranging from 10 to 60 million dollars annually. Unfortunately, scouting for stink bug damage in the field is laborious and excessively time consuming. To improve scouting accuracy and efficiency, we investigated fluorescence changes in cotton boll tissues as a result of stink bug feeding. Results Fluorescent imaging under long-wave ultraviolet light showed that stink bug-damaged lint, the inner carpal wall, and the outside of the boll emitted strong blue-green fluorescence in a circular region near the puncture wound, whereas undamaged tissue emissions occurred at different wavelengths; the much weaker emission of undamaged tissue was dominated by chlorophyll fluorescence. We further characterized the optimum emission and excitation spectra to distinguish between stink bug damaged bolls from undamaged bolls. Conclusions The observed characteristic fluorescence peaks associated with stink bug damage give rise to a fluorescence-based method to rapidly distinguish between undamaged and stink bug damaged cotton bolls. Based on the fluorescent fingerprint, we envision a fluorescence reflectance imaging or a fluorescence ratiometric device to assist pest management professionals with rapidly determining the extent of stink bug damage in a cotton field.

  7. Electromechanical Peak Devices of Distributed Power Generation

    Directory of Open Access Journals (Sweden)

    S. V. Konstantinova

    2011-01-01

    Full Text Available The power world crises (1973, 1979 have demonstrated that mankind entered the expensive energy epoch. More and more attitude is given to power saving problem by including renewable power sources in energy balance of the countries. The paper analyzes a power system inBelarusand a typical chart of the active load is cited in the paper. Equalization of load chart is considered as one of measures directed on provision of higher operational efficiency of power system and power saving.  This purpose can be obtained while including electromechanical peak devices of the distributed generation in the energy balance.

  8. LARAMIE PEAK WILDERNESS STUDY AREA, WYOMING.

    Science.gov (United States)

    Segerstrom, Kenneth; Weisner, R.C.

    1984-01-01

    On the basis of a mineral survey, most of the Laramie Peak Wilderness study area in Wyoming was concluded to have little promise for the occurrence of mineral or energy resources. Only three small areas in the northern part, one extending outside the study area to Esterbrook, were found to have probable mineral-resource potential for copper and lead. The geologic setting precludes the presence of fossil-fuel resources in the study area. There are no surface indications that geothermal energy could be developed within or near the study area.

  9. Forecasting peaks of seasonal influenza epidemics.

    Science.gov (United States)

    Nsoesie, Elaine; Mararthe, Madhav; Brownstein, John

    2013-06-21

    We present a framework for near real-time forecast of influenza epidemics using a simulation optimization approach. The method combines an individual-based model and a simple root finding optimization method for parameter estimation and forecasting. In this study, retrospective forecasts were generated for seasonal influenza epidemics using web-based estimates of influenza activity from Google Flu Trends for 2004-2005, 2007-2008 and 2012-2013 flu seasons. In some cases, the peak could be forecasted 5-6 weeks ahead. This study adds to existing resources for influenza forecasting and the proposed method can be used in conjunction with other approaches in an ensemble framework.

  10. Peak oil, economic growth, and wildlife conservation

    CERN Document Server

    Gates, J Edward; Czech, Brian

    2014-01-01

    The proposed book focuses on one of the most important issues affecting humankind in this century - Peak Oil or the declining availability of abundant, cheap energy-and its effects on our industrialized economy and wildlife conservation. Energy will be one of the defining issues of the 21st Century directly affecting wildlife conservation wherever energy extraction is a primary economic activity and indirectly through deepening economic recessions. Since cheap, abundant energy has been at the core of our industrial society, and has resulted in the technological advancements we enjoy today, the

  11. Particle creation by peak electric field

    CERN Document Server

    Adorno, T C; Gitman, D M

    2016-01-01

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially-increasing and another exponentially-decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered.

  12. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  13. Beyond the Peak - Tactile Temporal Discrimination Does Not Correlate with Individual Peak Frequencies in Somatosensory Cortex.

    Science.gov (United States)

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2017-01-01

    The human sensory systems constantly receive input from different stimuli. Whether these stimuli are integrated into a coherent percept or segregated and perceived as separate events, is critically determined by the temporal distance of the stimuli. This temporal distance has prompted the concept of temporal integration windows or perceptual cycles. Although this concept has gained considerable support, the neuronal correlates are still discussed. Studies suggested that neuronal oscillations might provide a neuronal basis for such perceptual cycles, i.e., the cycle lengths of alpha oscillations in visual cortex and beta oscillations in somatosensory cortex might determine the length of perceptual cycles. Specifically, recent studies reported that the peak frequency (the frequency with the highest spectral power) of alpha oscillations in visual cortex correlates with subjects' ability to discriminate two visual stimuli. In the present study, we investigated whether peak frequencies in somatosensory cortex might serve as the correlate of perceptual cycles in tactile discrimination. Despite several different approaches, we were unable to find a significant correlation between individual peak frequencies in the alpha- and beta-band and individual discrimination abilities. In addition, analysis of Bayes factor provided evidence that peak frequencies and discrimination thresholds are unrelated. The results suggest that perceptual cycles in the somatosensory domain are not necessarily to be found in the peak frequency, but in other frequencies. We argue that studies based solely on analysis of peak frequencies might thus miss relevant information.

  14. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    Science.gov (United States)

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported.

  15. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  16. Equivalence Principle and the Baryon Acoustic Peak

    CERN Document Server

    Baldauf, Tobias; Simonović, Marko; Zaldarriaga, Matias

    2015-01-01

    We study the dominant effect of a long wavelength density perturbation $\\delta(\\lambda_L)$ on short distance physics. In the non-relativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at $l_{\\rm BAO}$, this naive expectation breaks down for $\\lambda_Lpeak, and is calculable to all orders in the long modes. This can be used to improve the result of perturbative calculations - a technique known as "infra-red resummation"- and is explicitly applied to the one-loop calculation of power spectrum. Finally, the success of BAO reconstruction schemes is argue...

  17. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

  18. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    HAN GuangZe; CHEN MingDong

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms, and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent), the material will intensively absorb microwave energy. This is also known as resonant absorption, and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work, dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model, the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time, the expression of microwave peak absorption frequency as a func-tion of the material physical structure, rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene, and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material, but also provide a possible guide for the experiment of microwave-assisted extraction.

  19. Method and apparatus for current-output peak detection

    Energy Technology Data Exchange (ETDEWEB)

    De Geronimo, Gianluigi

    2017-01-24

    A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

  20. , Recorded at Ladron Peak, Central New Mexico

    Science.gov (United States)

    Ricketts, J. W.; Kelley, S.; Read, A. S.; Karlstrom, K. E.

    2010-12-01

    Ladron Peak, situated on the western flank of the Rio Grande rift ~30 miles NW of Socorro, NM, is composed of Precambrian granitic and metamorphic assemblages that have been faulted and uplifted during the late Tertiary formation of the rift. The area is bounded on three sides by normal faults, including the anomalously low-angle (~26°) Jeter fault to the east, which places Precambrian rocks in the footwall against Paleozoic and Mesozoic fault slivers, and mainly Cenozoic Santa Fe Group basin fill in the hanging wall. New apatite fission track (AFT) thermochronological data collected at 22 locations along the NE and SE margins of Ladron Peak give a range of ages from 10.9 ± 1.9 to 20.4 ± 8.6 Ma. Samples within the footwall include granitic and metasedimentary rocks that have mean track lengths of 13.1 to 14.1 μm; one quartzite sample has a mean track length of 12.5 μm, suggesting time in the partial annealing zone. Within the hanging wall block, new AFT ages from the Permian Bursum and Abo Formations give cooling ages of 23.1 ± 3.3 Ma. and 59.9 ± 12.4 Ma., respectively. The Bursum Formation sample, with a track length of 13.7 μm, cooled below the 110°C isotherm during the Miocene, while the Abo Formation sample, with a track length of 11.2 μm, was only partially reset prior to rift-related deformation. Mylonitized granitic and metamorphic rocks in the immediate footwall preserve dip-slip lineations that are parallel to slip on the Jeter fault. This suggests that strain associated with exhumation was recorded by both brittle and ductile deformation. Although this type of deformation is common within metamorphic core complexes in highly extended terranes, ductile normal faulting has not been recognized within the Rio Grande rift in New Mexico, though there is some suggestion of ductile deformation around Blanca Peak in the San Luis Valley in Colorado. These observations imply one or both of the following: (1) Ductile deformation at Ladron Peak was

  1. Fluorescence and Spectral Imaging

    Directory of Open Access Journals (Sweden)

    Ralph S. DaCosta

    2007-01-01

    Full Text Available Early identification of dysplasia remains a critical goal for diagnostic endoscopy since early discovery directly improves patient survival because it allows endoscopic or surgical intervention with disease localized without lymph node involvement. Clinical studies have successfully used tissue autofluorescence with conventional white light endoscopy and biopsy for detecting adenomatous colonic polyps, differentiating benign hyperplastic from adenomas with acceptable sensitivity and specificity. In Barrett's esophagus, the detection of dysplasia remains problematic because of background inflammation, whereas in the squamous esophagus, autofluorescence imaging appears to be more dependable. Point fluorescence spectroscopy, although playing a crucial role in the pioneering mechanistic development of fluorescence endoscopic imaging, does not seem to have a current function in endoscopy because of its nontargeted sampling and suboptimal sensitivity and specificity. Other point spectroscopic modalities, such as Raman spectroscopy and elastic light scattering, continue to be evaluated in clinical studies, but still suffer the significant disadvantages of being random and nonimaging. A recent addition to the fluorescence endoscopic imaging arsenal is the use of confocal fluorescence endomicroscopy, which provides real-time optical biopsy for the first time. To improve detection of dysplasia in the gastrointestinal tract, a new and exciting development has been the use of exogenous fluorescence contrast probes that specifically target a variety of disease-related cellular biomarkers using conventional fluorescent dyes and novel potent fluorescent nanocrystals (i.e., quantum dots. This is an area of great promise, but still in its infancy, and preclinical studies are currently under way.

  2. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM; Waldo, Geoffrey S [Santa Fe, NM; Kiss, Csaba [Los Alamos, NM

    2012-05-01

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

  3. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M.; Waldo, Geoffrey S.; Kiss, Csaba

    2011-03-22

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

  4. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  5. On the purported "backbone fluorescence" in protein three-dimensional fluorescence spectra

    DEFF Research Database (Denmark)

    Bortolotti, Annalisa; Wong, Yin How; Korsholm, Stine S.

    2016-01-01

    as any traditional protein emission spectrum. The many papers in reputable journals erroneously reporting this peak assignment, contradicting 5 decades of prior knowledge, have led to the creation of a new dogma, where many authors and reviewers now take the purported backbone fluorescence......In this study, several proteins (albumin, lysozyme, insulin) and model compounds (Trp, Tyr, homopolypeptides) were used to demonstrate the origin of the fluorescence observed upon their excitation at 220-230 nm. In the last 10 years we have observed a worrying increase in the number of articles...... claiming that this fluorescence originates from the protein backbone, contrary to the established knowledge that UV protein emission is due to aromatic amino acids only. Overall, our data clearly demonstrate that the observed emission upon excitation at 220-230 nm is due to the excitation of Tyr and/or Trp...

  6. Understanding microbial/DOM interactions using fluorescence and flow cytometry

    Science.gov (United States)

    Fox, Bethany; Rushworth, Cathy; Attridge, John; Anesio, Alexandre; Cox, Tim; Reynolds, Darren

    2015-04-01

    The transformation and movement of dissolved organic carbon (DOC) within freshwater aquatic systems is an important factor in the global cycling of carbon. DOC within aquatic systems is known to underpin the microbial food web and therefore plays an essential role in supporting and maintaining the aquatic ecosystem. Despite this the interactions between bacteria and dissolved organic matter (DOM) are not well understood, although the literature indicates that the microbial processing of bioavailable DOM is essential during the production of autochthonous, labile, DOM. DOM can be broadly characterised by its fluorescing properties and Coble et al. (2014) define terrestrially derived DOM as exhibiting "peak C" fluorescence, whilst labile microbially derived DOM is defined as showing "peak T" fluorescence. Our work explores the microbial/DOM interactions by analysing aquatic samples using fluorescence excitation and emission matrices (EEMs) in conjunction with microbial consumption of dissolved oxygen. Environmental and synthetic water samples were subjected to fluorescence characterisation using both fluorescence spectroscopy and in situ fluorescence sensors (Chelsea Technologies Group Ltd.). PARAFAC analysis and peak picking were performed on EEMs and compared with flow cytometry data, used to quantify bacterial numbers present within samples. Synthetic samples were created using glucose, glutamic acid, nutrient-rich water and a standard bacterial seed. Synthetic samples were provided with terrestrially derived DOM via the addition of an aliquot of environmental water. Using a closed system approach, samples were incubated over time (up to a maximum of 20 days) and analysed at pre-defined intervals. The main focus of our work is to improve our understanding of microbial/DOM interactions and how these interactions affect both the DOM characteristics and microbial food web in freshwater aquatic systems. The information gained, in relation to the origin, microbial

  7. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  8. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  9. Dependence of fluorescence intensity on the spectral overlap between fluorophores and plasmon resonant single silver nanoparticles.

    Science.gov (United States)

    Chen, Yeechi; Munechika, Keiko; Ginger, David S

    2007-03-01

    We investigate the fluorescence from dyes coupled to individual DNA-functionalized metal nanoparticles. We use single-particle darkfield scattering and fluorescence microscopy to correlate the fluorescence intensity of the dyes with the localized surface plasmon resonance (LSPR) spectra of the individual metal nanoparticles to which they are attached. For each of three different dyes, we observe a strong correlation between the fluorescence intensity of the dye and the degree of spectral overlap with the plasmon resonance of the nanoparticle. On average, we observe the brightest fluorescence from dyes attached to metal nanoparticles that have a LSPR scattering peak approximately 40-120 meV higher in energy than the emission peak of the fluorophore. These results should prove useful for understanding and optimizing metal-enhanced fluorescence.

  10. The study of blue LED to induce fluorescence spectroscopy and fluorescence imaging for oral carcinoma detection

    Science.gov (United States)

    Zheng, Longjiang; Hu, Yuanting

    2009-07-01

    Fluorescence spectroscopy and fluorescence imaging diagnosis of malignant lesions provides us with a new method to diagnose diseases in precancerous stage. Early diagnosis of disease has significant importance in cancer treatment, because most cancers can be cured well in precancerous, especially when the diffusion of cancer is limited in a restricted region. In this study, Golden hamster models were applied to 5% 9, 10 dimethyl-1, 2-benzanthracene (DMBA) to induce hamster buccal cheek pouch carcinoma three times a week. Rose Bengal, which has been used in clinican for years and avoids visible side-effect to human was chosen as photosensitizer. 405 nm blue LED was used to induce the fluorescence of photosensitizer. After topical application of photosensitizer, characteristic red emission fluorescence peak was observed around 600nm. Similar, normal oral cavity has special luminescence around 480nm. Fluorescence spectroscopy technology is based on analysing emission peaks of photosensitizer in the areas of oral carcinoma, moreover, red-to-green (IR/IG) intensity ratio is also applied as a diagnostic algorithm. A CCD which is connected with a computer is used to take pictures at carcinoma areas through different filters. Fluorescence images from normal hamster buccal cheek pouch are compared with those from carcinogen-induced models of carcinoma, and morphological differences between normal and lesion tissue can be distinguished. The pictures are analyzed by Matlab and shown on the screen of computer. This paper demonstrates that Rose Bengal could be used as photosensitizer to detect oral carcinoma, and blue LED as excitation source could not only have a good effect to diagnose oral carcinoma, but also decrease cost greatly.

  11. Introduction to fluorescence

    CERN Document Server

    Jameson, David M

    2014-01-01

    "An essential contribution to educating scientists in the principles of fluorescence. It will also be an important addition to the libraries of practitioners applying the principles of molecular fluorescence."-Ken Jacobson, Kenan Distinguished Professor of Cell Biology and Physiology, University of North Carolina at Chapel Hill"An exquisite compendium of fluorescence and its applications in biochemistry enriched by a very exciting historical perspective. This book will become a standard text for graduate students and other scientists."-Drs. Zygmunt (Karol) Gryczynski and Ignacy Gryczynski, University of North Texas Health Science Center"… truly a masterwork, combining clarity, precision, and good humor. The reader, novice or expert, will be pleased with the text and will not stop reading. It is a formidable account of the fluorescence field, which has impacted the life sciences so considerably in the last 60 years."-Jerson L. Silva, M.D., Ph.D., Professor and Director, National Institute of Science and Tech...

  12. Functional Fluorescent Organic Nanoparticles

    OpenAIRE

    Campioli, Elisa

    2013-01-01

    This thesis presents an extensive study on fluorescent organic nanoparticles and fluorescent organic binary and ternary nanoassemblies. In particular the attention is focused on the preparation and characterization of organic nanoparticles and new nanocomposites obtained from different types of small organic molecules, their stabilization and the use of these materials for biological and optoelectronics applications. The work deals at the beginning with the description of some methods used...

  13. [Study on fluorescence spectra of Chinese rice wine].

    Science.gov (United States)

    Liu, Zhou-yi; Zhu, Tuo; Gu, En-dong; Liu, Ying; Song, Chun-yuan

    2008-10-01

    Chinese rice wine has a history of more than 5000 years, only in China, hich is called "Nation Wine", and Shao Xing Chinese rice wine is a representative of it. The fluorescence spectra of 3 kinds of Shao Xing Chinese rice wine with different storage age induced by suitable UV-light were obtained in the present paper through experiment. The authors compared and analyzed them comprehensively by using three dimensional contour and two dimensional fluorescence technique, and found that their best induced light was all in the vicinity of 370 nm. The peak wavelength of 3 year storage age wine was 504 nm, while 488 nm and 505 nm were for 5 and 8 year storage age wine respectively. The emitted fluorescence existed in 400 to 680 nm, which had wide peak. More over, the emitting mechanism of Shao Xing Chinese rice wine was discussed. The authors also have explained the similarity and difference of fluorescence spectra among the 3 kinds of wine. The reason for wide fluorescence peak was also analyzed. This investigation contributes to the study of the characteristic, year detection and food safety of Chinese rice wine.

  14. Investigation of Laser Induced Fluorescence for Concentration Measurements of Diatomic Sulfur.

    Science.gov (United States)

    1981-12-01

    Once the spectrum was obtained, it was calibrated with N2 laser scatter and a mercury reference run. Fluorescence peaks were identified by com... Freddie , Jr. The Measurement of Quenching Rate Constants Using Fluorescence Emission. MS Thesis. Wright-Patterson Air Force Base, Ohio: Air Force Institute

  15. Fluorescence of muscle and connective tissue from cod and salmon

    DEFF Research Database (Denmark)

    Andersen, Charlotte Møller; Wold, J.P.

    2003-01-01

    Autofluorescence of salmon and cod muscle was measured and compared with autofluorescence of collagen type I and type V. Similarities between fluorescence of fish muscle and collagen were found in that the same peaks were obtained around 390, 430, and 480 nm, These similarities are supported by p...

  16. Fluorescent Pressure Response of Protein-Nanocluster Polymer Composites

    Science.gov (United States)

    2016-05-01

    fluorescence spectra of BSA:AuNCs found in literature.10 Notably, the BSA:AuNCs experience peak broadening and blue shifting upon incorporation into the...semiconductor quantum dots. Nature Biotechnology . 2004;22:969–976. 9. Medintz IL, Uyeda TH, Goldman ER, Mattoussi H. Quantum dot bioconjugates for imaging

  17. Peak, multi-peak and broadband absorption in graphene-based one-dimensional photonic crystal

    Science.gov (United States)

    Miloua, R.; Kebbab, Z.; Chiker, F.; Khadraoui, M.; Sahraoui, K.; Bouzidi, A.; Medles, M.; Mathieu, C.; Benramdane, N.

    2014-11-01

    We theoretically investigate the possibility of enhancing light absorption in graphene-based one dimensional photonic crystal. We demonstrate that it is possible to achieve total light absorption at technologically important wavelengths using one-dimensional graphene-based photonic crystals. By means of the transfer matrix method, we investigate the effect of refractive indices and layer numbers on the optical response of the structure. We found that it is possible to achieve one peak, multi-peak or broadband, and complete optical absorption. As a result, the proposed photonic structures enable myriad potential applications such as photodetection, shielding and optical sensing.

  18. Conversion of logarithmic channel numbers into relative linear fluorescence intensity.

    Science.gov (United States)

    Schmid, I; Schmid, P; Giorgi, J V

    1988-11-01

    We describe a simple, reproducible, and generally applicable method to assess the performance of log amplifiers by using a fluorescent sample that provides multiple peaks of different intensities. The channel differences between multiple peaks are used to evaluate the logarithmic behavior of the fluorescence signal amplifier on the flow cytometer. A calibration curve can be created to correct the channel numbers for deviations from true logarithmic behavior and then convert data into relative linear intensities. By using these linear fluorescent intensities, we compared the capacity of different antisera against HIV-1 (human immunodeficiency virus type 1) peptides to inhibit the binding of HIV-1 to CEM, a CD4-positive T-cell line. A wide range of applications for this calibration procedure can be envisioned and the method is valuable for monitoring instrument performance over time.

  19. Norwegian hydropower a valuable peak power source

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, Hermod

    2010-07-01

    given on a possible increase of the Norwegian hydropower peak power production to meet the growing the European demand for peak power caused by the growing non stationary production from wind mills and ocean energy from waves and sea current. Also building of reversible pump turbine power plants will be discussed even if approximately 10% power will be consumed by loss in the pumping phase compared to direct use of the water from reservoirs. (Author)

  20. Fluorescence self-quenching of tetraphenylporphyrin in liquid medium

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Mihir [Integrated Science Education and Research Centre, Siksha-Bhavana, Visva-Bharati, Santiniketan 731235 (India); Nath, Sukhendu [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Hajra, Alakananda [Department of Chemistry, Siksha-Bhavana, Visva-Bharati, Santiniketan 731235 (India); Sinha, Subrata, E-mail: subratasinha67@rediffmail.com [Integrated Science Education and Research Centre, Siksha-Bhavana, Visva-Bharati, Santiniketan 731235 (India)

    2013-09-15

    Self-quenching of the fluorescence emission of tetraphenylporphyrin at high concentrations in toluene at the ambient temperature (300 K) is discussed in detail based on steady state and time-resolved fluorescence measurements. The fluorescence self-quenching is mainly attributed to re-absorption effect and the Förster type resonance energy transfer process (homotransfer). The re-absorption effect is found to deform the fluorescence emission spectra significantly in energy positions as well as relative intensities of different peaks at high concentrations. Nearly ideal fluorescence emission spectra are observed at a concentration ∼10{sup −7} mol/L. Moreover, there is an apparent enhancement of the fluorescence lifetime value of tetraphenylporphyrin in toluene at high concentrations, especially on the blue side of the fluorescence emission spectra. To the best knowledge of the authors, this is the first detail report on the fluorescence self-quenching of porphyrins in liquid medium. This finding carries great importance in view of the widespread research on porphyrins in the fields of solar light harvesting, artificial photosynthesis, photodynamic therapy, etc. -- Highlights: • The effect of concentration on the fluorescence emission spectra of tetraphenylporphyrin (TPhP) in toluene at 300 K is investigated by using steady state and time-resolved fluorescence techniques. • Both re-absorption effect and the Förster type resonance energy transfer are found to be responsible for the observed fluorescence self-quenching at high concentrations. • These investigations are extremely important in view of the extensive applications of porphyrins in the fabrication of molecular electronic devices, especially for solar and artificial photosynthetic devices, where highly concentrated porphyrins are often used for efficient light harvesting.

  1. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak...

  2. Peak phosphorus - peak food? The need to close the phosphorus cycle.

    Science.gov (United States)

    Rhodes, Christopher J

    2013-01-01

    The peak in the world production of phosphorus has been predicted to occur in 2033, based on world reserves of rock phosphate (URR) reckoned at around 24,000 million tonnes (Mt), with around 18,000 Mt remaining. This figure was reckoned-up to 71,000 Mt, by the USGS, in 2012, but a production maximum during the present century is still highly probable. There are complex issues over what the demand will be for phosphorus in the future, as measured against a rising population (from 7 billion to over 9 billion in 2050), and a greater per capita demand for fertiliser to grow more grain, in part to feed animals and meet a rising demand for meat by a human species that is not merely more populous but more affluent. As a counterweight to this, we may expect that greater efficiencies in the use of phosphorus - including recycling from farms and of human and animal waste - will reduce the per capita demand for phosphate rock. The unseen game changer is peak oil, since phosphate is mined and recovered using machinery powered by liquid fuels refined from crude oil. Hence, peak oil and peak phosphorus might appear as conjoined twins. There is no unequivocal case that we can afford to ignore the likelihood of a supply-demand gap for phosphorus occurring sometime this century, and it would be perilous to do so.

  3. Analysis of the Peak Resistance Frequency Method.

    Science.gov (United States)

    Wang, Boshuo; Weiland, James D

    2016-10-01

    This study analyzes the peak resistance frequency (PRF) method described by Mercanzini et al., a method that can easily extract the tissue resistance from impedance spectroscopy for many neural engineering applications but has no analytical description thus far. Mathematical analyses and computer simulations were used to explore underlying principles, accuracy, and limitations of the PRF method. The mathematical analyses demonstrated that the PRF method has an inherent but correctable deviation dependent on the idealness of the electrode-tissue interface, which is validated by simulations. Further simulations show that both frequency sampling and noise affect the accuracy of the PRF method, and in general, it performs less accurately than least squares methods. However, the PRF method achieves simplicity and reduced measurement and computation time at the expense of accuracy. From the qualitative results, the PRF method can work with reasonable precision and simplicity, although its limitation and the idealness of the electrode-tissue interface involved should be taken into consideration. This paper provides a mathematical foundation for the PRF method and its practical implementation.

  4. Z-peaked excess in goldstini scenarios

    CERN Document Server

    Liew, Seng Pei; Mawatari, Kentarou; Sakurai, Kazuki; Vereecken, Matthias

    2015-01-01

    We study a possible explanation of a 3.0 $\\sigma$ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain $\\tilde g\\to g\\tilde\\chi^0_{1,2}\\to gZ\\tilde G'$ becomes dominant, where $\\tilde\\chi^0_{1,2}$ and $\\tilde G'$ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as $m_{\\tilde g}\\sim 900$ GeV, $m_{\\tilde\\chi^0_{1,2}}\\sim 700$ GeV and $m_{\\tilde G'}\\sim 600$ GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  5. Z-peaked excess in goldstini scenarios

    Directory of Open Access Journals (Sweden)

    Seng Pei Liew

    2015-11-01

    Full Text Available We study a possible explanation of a 3.0 σ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain g˜→gχ˜1,20→gZG˜′ becomes dominant, where χ˜1,20 and G˜′ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as mg˜∼1000 GeV, mχ˜1,20∼800 GeV and mG˜′∼600 GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  6. Asymmetry parameter of peaked Fano line shapes

    Science.gov (United States)

    Meierott, S.; Hotz, T.; Néel, N.; Kröger, J.

    2016-10-01

    The spectroscopic line shape of electronic and vibrational excitations is ubiquitously described by a Fano profile. In the case of nearly symmetric and peaked Fano line shapes, the fit of the conventional Fano function to experimental data leads to difficulties in unambiguously extracting the asymmetry parameter, which may vary over orders of magnitude without degrading the quality of the fit. Moreover, the extracted asymmetry parameter depends on initially guessed values. Using the spectroscopic signature of the single-Co Kondo effect on Au(110) the ambiguity of the extracted asymmetry parameter is traced to the highly symmetric resonance profile combined with the inevitable scattering of experimental data. An improved parameterization of the conventional Fano function is suggested that enables the nonlinear optimization in a reduced parameter space. In addition, the presence of a global minimum in the sum of squared residuals and thus the independence of start parameters may conveniently be identified in a two-dimensional plot. An angular representation of the asymmetry parameter is suggested in order to reliably determine uncertainty margins via linear error propagation.

  7. Solid-State Carbon Dots with Red Fluorescence and Efficient Construction of Dual-Fluorescence Morphologies.

    Science.gov (United States)

    He, Jiangling; He, Youling; Chen, Yonghao; Lei, Bingfu; Zhuang, Jianle; Xiao, Yong; Liang, Yeru; Zheng, Mingtao; Zhang, Haoran; Liu, Yingliang

    2017-07-01

    Stable solid-state red fluorescence from organosilane-functionalized carbon dots (CDs) with sizes around 3 nm is reported for the first time. Meanwhile, a novel method is also first reported for the efficient construction of dual-fluorescence morphologies. The quantum yield of these solid-state CDs and their aqueous solution is 9.60 and 50.7%, respectively. The fluorescence lifetime is 4.82 ns for solid-state CDs, and 15.57 ns for their aqueous solution. These CDs are detailedly studied how they can exhibit obvious photoluminescence overcoming the self-quenching in solid state. Luminescent materials are constructed with dual fluorescence based on as-prepared single emissive CDs (red emission) and nonfluorescence media (starch, Al2 O3 , and RnOCH3 COONa), with the characteristic peaks located at nearly 440 and 600 nm. Tunable photoluminescence can be successfully achieved by tuning the mass ratio of CDs to solid matrix (such as starch). These constructed dual-fluorescence CDs/starch composites can also be applied in white light-emitting diodes with UV chips (395 nm), and oxygen sensing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  9. Stroboscopic fluorescence lifetime imaging.

    Science.gov (United States)

    Holton, Mark D; Silvestre, Oscar R; Errington, Rachel J; Smith, Paul J; Matthews, Daniel R; Rees, Paul; Summers, Huw D

    2009-03-30

    We report a fluorescence lifetime imaging technique that uses the time integrated response to a periodic optical excitation, eliminating the need for time resolution in detection. A Dirac pulse train of variable period is used to probe the frequency response of the total fluorescence per pulse leading to a frequency roll-off that is dependent on the relaxation rate of the fluorophores. The technique is validated by demonstrating wide-field, realtime, lifetime imaging of the endocytosis of inorganic quantum dots by a cancer cell line. Surface charging of the dots in the intra-cellular environment produces a switch in the fluorescence lifetime from approximately 40 ns to technique offers lifetime based imaging at video rates with standard CCD cameras and has application in probing millisecond cell dynamics and in high throughput imaging assays.

  10. Nanosecond fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Leskovar, B.

    1985-03-01

    This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are discussed. A short comparison of the most important deconvolution methods for numerical analysis of experimental data is given particularly with respect to the signal-to-noise ratio of the fluorescence signal. 22 refs., 8 figs.

  11. Evaluating Activated Carbon Adsorption of Dissolved Organic Matter and Micropollutants Using Fluorescence Spectroscopy.

    Science.gov (United States)

    Shimabuku, Kyle K; Kennedy, Anthony M; Mulhern, Riley E; Summers, R Scott

    2017-02-14

    Dissolved organic matter (DOM) negatively impacts granular activated carbon (GAC) adsorption of micropollutants and is a disinfection byproduct precursor. DOM from surface waters, wastewater effluent, and 1 kDa size fractions were adsorbed by GAC and characterized using fluorescence spectroscopy, UV-absorption, and size exclusion chromatography (SEC). Fluorescing DOM was preferentially adsorbed relative to UV-absorbing DOM. Humic-like fluorescence (peaks A and C) was selectively adsorbed relative to polyphenol-like fluorescence (peaks T and B) potentially due to size exclusion effects. In the surface waters and size fractions, peak C was preferentially removed relative to peak A, whereas the reverse was found in wastewater effluent, indicating that humic-like fluorescence is associated with different compounds depending on DOM source. Based on specific UV-absorption (SUVA), aromatic DOM was preferentially adsorbed. The fluorescence index (FI), if interpreted as an indicator of aromaticity, indicated the opposite but exhibited a strong relationship with average molecular weight, suggesting that FI might be a better indicator of DOM size than aromaticity. The influence of DOM intermolecular interactions on adsorption were minimal based on SEC analysis. Fluorescence parameters captured the impact of DOM size on the fouling of 2-methylisoborneol and warfarin adsorption and correlated with direct competition and pore blockage indicators.

  12. Measurements of the Ultraviolet Fluorescence Cross Sections and Spectra of Bacillus Anthracis Simulants

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, J.R.

    1998-09-01

    Measurements of the ultraviolet autofluorescence spectra and absolute cross sections of the Bacillus anthracis (Ba) simulants Bacillus globigii (Bg), Bacillus megaterium (Bm), Bacillus subtilis (Bs), and Bacillus cereus (Bc) were measured. Fluorescence spectra and cross sections of pine pollen (Pina echinata) were measured for comparison. Both dried vegetative cells and spores separated from the sporulated vegetative material were studied. The spectra were obtained by suspending a small number (<10) of particles in air in our Single Particle Spectroscopy Apparatus (SPSA), illuminating the particles with light from a spectrally filtered arc lamp, and measuring the fluorescence spectra of the particles. The illumination was 280 nm (20 nm FWHM) and the fluorescence spectra was measured between 300 and 450 nm. The fluorescence cross section of vegetative Bg peaks at 320 nm with a maximum cross section of 5 X 10{sup -14} cm{sup 2}/sr-nm-particle while the Bg spore fluorescence peaks at 310 nm with peak fluorescence of 8 X 10{sup -15} cm{sup 2}/sr-nm-particle. Pine pollen particles showed a higher fluorescence peaking at 355 nm with a cross section of 1.7 X 10{sup -13} cm{sup 2}/sr-nm-particle. Integrated cross sections ranged from 3.0 X 10{sup -13} for the Bg spores through 2.25 X 10{sup -12} (cm{sup 2}/sr-particle) for the vegetative cells.

  13. Laser-induced fluorescence detection of stomach cancer using hypericin

    Science.gov (United States)

    Dets, Sergiy M.; Buryi, Alexander N.; Melnik, Ivan S.; Joffe, Alexander Y.; Rusina, Tatyana V.

    1996-12-01

    Natural photodynamic pigment hypericin having intrinsic antitumor properties was applied for fluorescence detection of cancer. Clinical investigation of hypericin was performed to ensure high tumor/normal fluorescence contrast in digestion organs. Laser-induced autofluorescence and exogenous fluorescence analysis of normal tissue and stomach adenocarcinoma was performed using helium-cadmium laser (8 mW, 442 nm). Twenty-one patients have undergone procedure of fluorescence detection of tumors before and after photosensitization. For sensitization of patients we used five or seven capsules containing hypericin in amount of 1 mg which have been administered orally. Strong yellow-red fluorescence of hypericin in tissue with maximum at 603 nm and autofluorescence peak at 535 nm gives an intensity ratio I(603 nm)/I(535 nm) of 2 - 2.5 from cancerous tissue and provides 85% specificity. Preliminary in vivo results of auto- and fluorescence analysis using hypericin photosensitization from one patient with esophageal cancer and eleven patients with stomach cancer proven histologically are encouraging and indicate the high reliability of laser-induced fluorescence technique with hypericin in detection of early stage malignant lesions.

  14. Laser-saturated fluorescence measurements in laminar sooting diffusion flames

    Science.gov (United States)

    Wey, Changlie

    1993-01-01

    The hydroxyl radical is known to be one of the most important intermediate species in the combustion processes. The hydroxyl radical has also been considered a dominant oxidizer of soot particles in flames. In this investigation the hydroxyl concentration profiles in sooting diffusion flames were measured by the laser-saturated fluorescence (LSF) method. The temperature distributions in the flames were measured by the two-line LSF technique and by thermocouple. In the sooting region the OH fluorescence was too weak to make accurate temperature measurements. The hydroxyl fluorescence profiles for all four flames presented herein show that the OH fluorescence intensities peaked near the flame front. The OH fluorescence intensity dropped sharply toward the dark region of the flame and continued declining to the sooting region. The OH fluorescence profiles also indicate that the OH fluorescence decreased with increasing height in the flames for all flames investigated. Varying the oxidizer composition resulted in a corresponding variation in the maximum OH concentration and the flame temperature. Furthermore, it appears that the maximum OH concentration for each flame increased with increasing flame temperature.

  15. Fluorescence Experiments with Quinine

    Science.gov (United States)

    O'Reilly, James E.

    1975-01-01

    Describes a series of experiments which illustrate the analytical capabilities of fluorescence, and outlines two straightforward analyses involving real analyses. These experiments are suitable for an undergraduate instrumental analysis course and require approximately six to seven hours of laboratory time. (MLH)

  16. FLEX: fluorescence explorer

    NARCIS (Netherlands)

    Stoll, M.Ph.; Court, A.J.; Smorenburg, C.; Visser, H.; Crocco, L.; Heilimo, J.; Honig, A.

    1999-01-01

    FLEX is a scientifically driven space mission to provide demonstration/validation of the instrumentation and technique for measuring the natural fluorescence of vegetation in the Fraunhofer lines. The payload consists of high spectral resolution (0.1-0.3 nm) CCD imaging grating spectrometer with two

  17. Study on fluorescence spectra of molecular association of acetic acid-water

    Institute of Scientific and Technical Information of China (English)

    Caiqin Han; Ying Liu; Yang Yang; Xiaowu Ni; Jian Lu; Xiaosen Luo

    2009-01-01

    Fluorescence spectra of acetic acid-water solution excited by ultraviolet (UV) light are studied, and the relationship between fluorescence spectra and molecular association of acetic acid is discussed. The results indicate that when the exciting light wavelength is longer than 246 nm, there are two fluorescence peaks located at 305 and 334 nm, respectively. By measuring the excitation spectra, the optimal wavelengths of the two fluorescence peaks are obtained, which are 258 and 284 nm, respectively. Fluorescence spectra of acetic acid-water solution change with concentrations, which is primarily attributed to changes of molecular association of acetic acid in aqueous solution. Through theoretical analysis, three variations of molecular association have been obtained in acetic acid-water solution, which are the hydrated monomers, the linear dimers, and the water separated dimers. This research can provide references to studies of molecular association of acetic acid-water, especially studies of hydrogen bonds.

  18. A Transformer Partial Discharge Measurement System Based on Fluorescent Fiber

    Directory of Open Access Journals (Sweden)

    Fan Liu

    2012-05-01

    Full Text Available Based on the physical phenomena of optical effects produced by the partial discharge (PD and on the characteristics of fluorescent fiber sensing of weak fluorescent signals, a PD measurement system using a fluorescent fiber sensor was designed. The main parameters of the sensing system were calculated, an experimental testing platform for PD simulation in the lab was established, and PD signals were then detected through ultra-high frequency (UHF and optical methods under a needle-plate discharge model. PD optical pulses in transformer oil contained signal-peak and multi-peak pulse waveforms. Compared with UHF detection results, the number of PD pulses and the elapsed PD pulse phase time revealed a good corresponding relationship. However, PD signal amplitudes presented the opposite, thus indicating that PD UHF signals reflected pulse amplitude value, whereas PD optical signals reflected pulse energy magnitude. The n-u-φ three-dimensional distributions indicated that most of the PD signals concentrated in the nearby industrial frequency voltage peak value. Overall, the proposed fluorescent fiber sensing system design can be used successfully in transformer PD signal detection.

  19. ASSESSING PEAK AEROBIC CAPACITY IN DUTCH LAW ENFORCEMENT OFFICERS

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report norm

  20. Peak-power-point monitor for solar panel

    Science.gov (United States)

    Schloss, A. I.

    1972-01-01

    Attempt was made to determine solar cell panel peak power capability without disrupting power flow from panel. Separate solar cell strings were switched from panel circuits, and increasingly larger loads were added rapidly until peak power points were transversed. String wattage output was recorded and all stored string measurements summed together indicate peak power point in panel.

  1. [A fluorescence quenching method for the determination of trace chlorite in water with rhodamine B].

    Science.gov (United States)

    Kang, Cai-yan; Jiang, Zhi-liang; Xi, Dan-li

    2007-02-01

    In acidic sodium acetate-HCl buffer solution containing KI, Rhodamine B (RhB) has a fluorescence peak at 580 nm. When ClO2(-) exists fluorescence quenching occur. The fluorescence quenching intensity is linear with the concentration of ClO2(-) in the range of 0.0218-0.51 microg x mL(-1). Based on this, a new, simple, sentisive fluorescence method has been proposed for the determination of ClO2(-) in water, with satisfactory results.

  2. A fluorescence spectroscopic study of a coagulating protein extracted from Moringa oleifera seeds.

    Science.gov (United States)

    Kwaambwa, H M; Maikokera, R

    2007-11-15

    The fluorescence studies of coagulating protein extracted from Moringa oleifera seeds have been studied using steady-state intrinsic fluorescence. The fluorescence spectra are dominated by tryptophan emission and the emission peak maximum (lambda(max)=343+ or -2nm) indicated that the tryptophan residue is not located in the hydrophobic core of the protein. Changes in solution pH affected the protein conformation as indicated by changes in the tryptophan fluorescence above pH 9 whereas the ionic strength had minimal effect. The exposure and environments of the tryptophan residue were determined using collisional quenchers.

  3. [Analysis of fluorescence spectrum of petroleum-polluted water].

    Science.gov (United States)

    Huang, Miao-Fen; Song, Qing-Jun; Xing, Xu-Feng; Jian, Wei-Jun; Liu, Yuan; Zhao, Zu-Long

    2014-09-01

    In four ratio experiments, natural waters, sampled from the mountain reservoir and the sea water around Dalian city, were mixed with the sewage from petroleum refinery and petroleum exploitation plants. The fluorescence spectra of water samples containing only chromophoric dissolved organic matters(CDOM), samples containing only petroleum, and samples containing a mixture of petroleum and CDOM were analyzed, respectively. The purpose of this analysis is to provide a basis for determining the contribution of petroleum substances and CDOM to the total absorption coefficient of the petroleum-contaminated water by using fluorescence technique. The results showed that firstly, CDOM in seawater had three main fluorescence peaks at Ex: 225-230 nm/Em: 320-330 nm, Ex: 280 nm/Em: 340 nm and Ex: 225-240 nm/Em: 430-470 nm, respectively, and these may arise from the oceanic chlorophyll. CDOM in natural reservoir water had two main fluorescence peaks at EX: 240- 260 nm/Em: 420-450 nm and Ex: 310~350 nm/Em: 420--440 nm, respectively, and these may arise from the terrestrial sources; secondly, the water samples containing only petroleum extracted with n-hexane had one to three fluorescence spectral peaksat Ex: 220-240 nm/Em: 320-340 nm, Ex: 270-290 nm/Em: 310-340 nm and Ex: 220-235 nm/Em: 280-310 nm, respectively, caused by their hydrocarbon component; finally, the water samples containing both petroleum and CDOM showed a very strong fluorescence peak at Ex: 230-250 nm/Em: 320-370 nm, caused by the combined effect of CDOM and petroleum hydrocarbons.

  4. Economic and safety analysis of unconventional peak regulation on power unit of peak shifting start-stop

    Science.gov (United States)

    Cao, X.; Zhao, J. F.; Duan, X. Q.; Jin, Y. A.

    2017-01-01

    Tthe capacity difference of peak regulation between the power gird and the actual demand has become a serious problem considering the growth in the difference between electricity supply and demand. Therefore, peak regulation of power grid needs to be deeply studied. Unconventional peak regulation on unit of peak shifting start-stop is a way that can broaden the range of power regulation, as well as benefit safe operation of the power grid. However, it requires frequent and fast unit start-stop, complex operation, and more staff labor. By carrying out unconventional thermal power unit load test, the start-stop mode of peak auxiliary equipment is studied in this paper, indicating that it has a positive effect on safety and economic of load-peaking operation. The best working conditions of the peak units is found by analysing consumption cost, safety specifications, and life lost of the start-stop peak regulation mode.

  5. Dual-wavelength excitation to reduce background fluorescence for fluorescence spectroscopic quantitation of erythrocyte zinc protoporphyrin-IX and protoporphyrin-IX from whole blood and oral mucosa

    Science.gov (United States)

    Hennig, Georg; Vogeser, Michael; Holdt, Lesca M.; Homann, Christian; Großmann, Michael; Stepp, Herbert; Gruber, Christian; Erdogan, Ilknur; Hasmüller, Stephan; Hasbargen, Uwe; Brittenham, Gary M.

    2014-02-01

    Erythrocyte zinc protoporphyrin-IX (ZnPP) and protoporphyrin-IX (PPIX) accumulate in a variety of disorders that restrict or disrupt the biosynthesis of heme, including iron deficiency and various porphyrias. We describe a reagent-free spectroscopic method based on dual-wavelength excitation that can measure simultaneously both ZnPP and PPIX fluorescence from unwashed whole blood while virtually eliminating background fluorescence. We further aim to quantify ZnPP and PPIX non-invasively from the intact oral mucosa using dual-wavelength excitation to reduce the strong tissue background fluorescence while retaining the faint porphyrin fluorescence signal originating from erythrocytes. Fluorescence spectroscopic measurements were made on 35 diluted EDTA blood samples using a custom front-face fluorometer. The difference spectrum between fluorescence at 425 nm and 407 nm excitation effectively eliminated background autofluorescence while retaining the characteristic porphyrin peaks. These peaks were evaluated quantitatively and the results compared to a reference HPLC-kit method. A modified instrument using a single 1000 μm fiber for light delivery and detection was used to record fluorescence spectra from oral mucosa. For blood measurements, the ZnPP and PPIX fluorescence intensities from the difference spectra correlated well with the reference method (ZnPP: Spearman's rho rs = 0.943, p erythrocyte ZnPP and PPIX.

  6. Nanoscale resolution for fluorescence microscopy via adiabatic passage

    CERN Document Server

    Rubio, Juan Luis; Ahufinger, Verònica; Mompart, Jordi

    2015-01-01

    We propose the use of the subwavelength localization via adiabatic passage technique for fluorescence microscopy with nanoscale resolution in the far field. This technique uses a {\\Lambda}-type medium coherently coupled to two laser pulses: the pump, with a node in its spatial profile, and the Stokes. The population of the {\\Lambda} system is adiabatically transferred from one ground state to the other except at the node position, yielding a narrow population peak. This coherent localization allows fluorescence imaging with nanometer lateral resolution. We derive an analytical expression to asses the resolution and perform a comparison with the coherent population trapping and the stimulated-emission-depletion techniques.

  7. Femtosecond broadband fluorescence upconversion spectroscopy: Improved setup and photometric correction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.-X. [Photonics Center, College of Physical Science, Nankai University, Tianjin (China); Department of Chemistry, Humboldt Universitaet zu Berlin (Germany); Wuerth, C.; Resch-Genger, U. [Federal Institute for Materials Research and Testing, Berlin (Germany); Zhao, L. [Photonics Center, College of Physical Science, Nankai University, Tianjin (China); Ernsting, N. P.; Sajadi, M. [Department of Chemistry, Humboldt Universitaet zu Berlin (Germany)

    2011-06-15

    A setup for fluorescence upconversion spectroscopy (FLUPS) is described which has 80 fs temporal response (fwhm) for emission in the spectral range 425-750 nm. Broadband phase matching is achieved with tilted gate pulses at 1340 nm. Background from harmonics of the gate pulse is removed and sensitivity increased compared to previous designs. Photometric calibration of the upconversion process is performed with a set of fluorescent dyes. For Coumarin 153 in methanol the peak position, bandwidth, and asymmetry depending on delay time are reported.

  8. Femtosecond broadband fluorescence upconversion spectroscopy: Improved setup and photometric correction

    Science.gov (United States)

    Zhang, X.-X.; Würth, C.; Zhao, L.; Resch-Genger, U.; Ernsting, N. P.; Sajadi, M.

    2011-06-01

    A setup for fluorescence upconversion spectroscopy (FLUPS) is described which has 80 fs temporal response (fwhm) for emission in the spectral range 425-750 nm. Broadband phase matching is achieved with tilted gate pulses at 1340 nm. Background from harmonics of the gate pulse is removed and sensitivity increased compared to previous designs. Photometric calibration of the upconversion process is performed with a set of fluorescent dyes. For Coumarin 153 in methanol the peak position, bandwidth, and asymmetry depending on delay time are reported.

  9. The formation of peak rings in large impact craters.

    Science.gov (United States)

    Morgan, Joanna V; Gulick, Sean P S; Bralower, Timothy; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Collins, Gareth S; Coolen, Marco J L; Ferrière, Ludovic; Gebhardt, Catalina; Goto, Kazuhisa; Jones, Heather; Kring, David A; Le Ber, Erwan; Lofi, Johanna; Long, Xiao; Lowery, Christopher; Mellett, Claire; Ocampo-Torres, Rubén; Osinski, Gordon R; Perez-Cruz, Ligia; Pickersgill, Annemarie; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Schmitt, Douglas R; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Urrutia-Fucugauchi, Jaime; Whalen, Michael; Wittmann, Axel; Yamaguchi, Kosei E; Zylberman, William

    2016-11-18

    Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust. Copyright © 2016, American Association for the Advancement of Science.

  10. The formation of peak rings in large impact craters

    Science.gov (United States)

    Morgan, Joanna V.; Gulick, Sean P. S.; Bralower, Timothy; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Collins, Gareth S.; Coolen, Marco J. L.; Ferrière, Ludovic; Gebhardt, Catalina; Goto, Kazuhisa; Jones, Heather; Kring, David A.; Le Ber, Erwan; Lofi, Johanna; Long, Xiao; Lowery, Christopher; Mellett, Claire; Ocampo-Torres, Rubén; Osinski, Gordon R.; Perez-Cruz, Ligia; Pickersgill, Annemarie; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Schmitt, Douglas R.; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Urrutia-Fucugauchi, Jaime; Whalen, Michael; Wittmann, Axel; Yamaguchi, Kosei E.; Zylberman, William

    2016-11-01

    Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust.

  11. Synthesis and Fluorescence Spectra of Triazolylcoumarin Fluorescent Dyes

    Institute of Scientific and Technical Information of China (English)

    PENG Xian-fu; LI Hong-qi

    2009-01-01

    Much attention is devoted to fluorescent dyes especially those with potential in versatile applications. Reactions under "click" conditions between nonfluorescent 3 - azidocoumarins and terminal alkynes produced 3 -(1, 2, 3- triazol- 1 - yl)cournarins, a novel type of fluorescent dyes with intense fluorescence. The structures of the new coumarins were characterized by 1H NMR, MS, and IR spectra. Fluorescence spectra measurement demonstrated excellent fluorescence performance of the triazolylcoumarins and this click reaction is a promising candidate for bioconjugation and bioimaging applications since both azide and alkynes are quite inert to biological systems.

  12. Fluorescence nanoscopy. Methods and applications

    OpenAIRE

    Requejo-Isidro, Jose

    2013-01-01

    Fluorescence nanoscopy refers to the experimental techniques and analytical methods used for fluorescence imaging at a resolution higher than conventional, diffraction-limited, microscopy. This review explains the concepts behind fluorescence nanoscopy and focuses on the latest and promising developments in acquisition techniques, labelling strategies to obtain highly detailed super-resolved images and in the quantitative methods to extract meaningful information from them.

  13. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed

    2013-01-07

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  14. Automatic peak selection by a Benjamini-Hochberg-based algorithm.

    Directory of Open Access Journals (Sweden)

    Ahmed Abbas

    Full Text Available A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into [Formula: see text]-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx.

  15. Delayed fluorescence in photosynthesis.

    Science.gov (United States)

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  16. Fluorescence properties of human teeth and dental calculus for clinical applications.

    Science.gov (United States)

    Lee, Yong-Keun

    2015-04-01

    Fluorescent emission of human teeth and dental calculus is important for the esthetic rehabilitation of teeth, diagnosis of dental caries, and detection of dental calculus. The purposes of this review were to summarize the fluorescence and phosphorescence of human teeth by ambient ultraviolet (UV) light, to investigate the clinically relevant fluorescence measurement methods in dentistry, and to review the fluorescence of teeth and dental calculus by specific wavelength light. Dentine was three times more phosphorescent than enamel. When exposed to light sources containing UV components, the fluorescence of human teeth gives them the quality of vitality, and fluorescent emission with a peak of 440 nm is observed. Esthetic restorative materials should have fluorescence properties similar to those of natural teeth. Based on the fluorescence of teeth and restorative materials as determined with a spectrophotometer, a fluorescence parameter was defined. As to the fluorescence spectra by a specific wavelength, varied wavelengths were investigated for clinical applications, and several methods for the diagnosis of dental caries and the detection of dental calculus were developed. Since fluorescent properties of dental hard tissues have been used and would be expanded in diverse fields of clinical practice, these properties should be investigated further, embracing newly developed optical techniques.

  17. Fluorescence properties of human teeth and dental calculus for clinical applications

    Science.gov (United States)

    Lee, Yong-Keun

    2015-04-01

    Fluorescent emission of human teeth and dental calculus is important for the esthetic rehabilitation of teeth, diagnosis of dental caries, and detection of dental calculus. The purposes of this review were to summarize the fluorescence and phosphorescence of human teeth by ambient ultraviolet (UV) light, to investigate the clinically relevant fluorescence measurement methods in dentistry, and to review the fluorescence of teeth and dental calculus by specific wavelength light. Dentine was three times more phosphorescent than enamel. When exposed to light sources containing UV components, the fluorescence of human teeth gives them the quality of vitality, and fluorescent emission with a peak of 440 nm is observed. Esthetic restorative materials should have fluorescence properties similar to those of natural teeth. Based on the fluorescence of teeth and restorative materials as determined with a spectrophotometer, a fluorescence parameter was defined. As to the fluorescence spectra by a specific wavelength, varied wavelengths were investigated for clinical applications, and several methods for the diagnosis of dental caries and the detection of dental calculus were developed. Since fluorescent properties of dental hard tissues have been used and would be expanded in diverse fields of clinical practice, these properties should be investigated further, embracing newly developed optical techniques.

  18. Near-infrared (NIR) fluorescence imaging of head and neck squamous cell carcinoma for fluorescence-guided surgery (Conference Presentation)

    Science.gov (United States)

    Moore, Lindsay; Warram, Jason M.; de Boer, Esther; Carroll, William R.; Morlandt, Anthony; Withrow, Kirk P.; Rosenthal, Eben L.

    2016-03-01

    During fluorescence-guided surgery, a cancer-specific optical probe is injected and visualized using a compatible device intraoperatively to provide visual contrast between diseased and normal tissues to maximize resection of cancer and minimize the resection of precious adjacent normal tissues. Six patients with squamous cell carcinomas of the head and neck region (oral cavity (n=4) or cutaneous (n=2)) were injected with an EGFR-targeting antibody (Cetuximab) conjugated to a near-infrared (NIR) fluorescent dye (IRDye800) 3, 4, or 7 days prior to surgical resection of the cancer. Each patient's tumor was then imaged using a commercially available, open-field NIR fluorescence imaging device each day prior to surgery, intraoperatively, and post-operatively. The mean fluorescence intensity (MFI) of the tumor was calculated for each specimen at each imaging time point. Adjacent normal tissue served as an internal anatomic control for each patient to establish a patient-matched "background" fluorescence. Resected tissues were also imaged using a closed-field NIR imaging device. Tumor to background ratios (TBRs) were calculated for each patient using both devices. Fluorescence histology was correlated with traditional pathology assessment to verify the specificity of antibody-dye conjugate binding. Peak TBRs using the open-field device ranged from 2.2 to 11.3, with an average TBR of 4.9. Peak TBRs were achieved between days 1 and 4. This study demonstrated that a commercially available NIR imaging device suited for intraoperative and clinical use can successfully be used with a fluorescently-labeled dye to delineate between diseased and normal tissue in this single cohort human study, illuminated the potential for its use in fluoresence-guided surgery.

  19. Reference Values for Peak Exercise Cardiac Output in Healthy Individuals.

    Science.gov (United States)

    Agostoni, Piergiuseppe; Vignati, Carlo; Gentile, Piero; Boiti, Costanza; Farina, Stefania; Salvioni, Elisabetta; Mapelli, Massimo; Magrì, Damiano; Paolillo, Stefania; Corrieri, Nicoletta; Sinagra, Gianfranco; Cattadori, Gaia

    2017-06-01

    Cardiac output (Q˙) is a key parameter in the assessment of cardiac function, its measurement being crucial for the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, Q˙ determination at peak exercise has been possible through invasive methods, so that normal values were obtained in studies based on small populations. Nowadays, peak Q˙ can be measured noninvasively by means of the inert gas rebreathing (IGR) technique. The present study was undertaken to provide reference values for peak Q˙ in the normal general population and to obtain a formula able to estimate peak exercise Q˙ from measured peak oxygen uptake (V˙o2). We studied 500 normal subjects (age, 44.9 ± 1.5 years; range, 18-77 years; 260 men, 240 women) who underwent a maximal cardiopulmonary exercise test with peak Q˙ measurement by IGR. In the overall study sample, peak Q˙ was 13.2 ± 3.5 L/min (men, 15.3 ± 3.3 L/min; women, 11.0 ± 2.0 L/min; P exercise was (4.4 × peak V˙o2) + 4.3 in the overall study cohort, (4.3 × peak V˙o2) + 4.5 in men, and (4.9 × peak V˙o2) + 3.6 in women. The simultaneous measurement of Q˙ and V˙o2 at peak exercise in a large sample of healthy subjects provided an equation to predict peak Q˙ from peak V˙o2 values. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  20. Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Huijuan; WANG; Jin; WU; Yishi; YUAN; Gu; AI; Xicheng; WANG; Li

    2006-01-01

    The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluorescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased intensity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32 ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

  1. Characteristics of the Three-Dimensional Fluorescence pectra of Fossil Fuels

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    We have found some fluorescence characteristics of fossil fuels based on the contour maps of the tlhree-dimensional fluorescence spectra of their non-quenching samples. The common fluorescence characteristic is that themain peaks of various fossil fuels are located in the vicinity of excitation/emission wavelength pair 228nm/340nm.The diversity of fluorescence characteristics can be represented with several indexes α, K, F and R, and these index-es provide measurable parameters for division of fluorescence fingerprints of fossil fuels. The fluorescence fingerprintsof fossil fuels can be divided into five models named O,B,Q,P and G that are corresponding to condensate oil, lightoil, heavy oil, coal and natural gas, respectively. The technique has a potential application in study of environmentpollution on crude oil and geochemical exploration of fossil fuels.

  2. The exploration of the characteristics of the hyperglycemia serum fluorescence spectrum

    Science.gov (United States)

    Wang, Lexin; Zhao, Zhimin; Chen, Hui; Li, Peng; Xin, Yujun

    2008-12-01

    Now, spectra technology is widely used in the biomedicine research,so this study investigates variation of the fluorescence spectra in different excitation wavelength, and the spectra of serum with different glucose concentration is tested in the excitation wavelength of 240nm to 280nm. The experimental result shows that the correlation between the serum fluorescence intensity and the excitation light is very close, when the excitation light is in the ultraviolet wave band, the fluorescence of serum is intensive. There is a violent fluorescence emission wavelength, which is 300nm to 410nm, while the excitation wavelength ranges from 220nm to 290nm, and the peaks wavelength are 330nm and 370nm. From 240nm to 280nm, the serum fluorescence intensity increases synchronously with the glucose concentration, and the relationship between the fluorescence peak wavelength and the glucose concentration is almost in line. In this way the blood sugar concentration can be estimated by the fluorescence spectra peak wavelength when the excitation wavelength is from 240nm to 280nm, which is effective. It provides experimental foundation for the wide use of spectra technology in medical diagnose, and the effectiv method to test the blood sugar concentration.

  3. Temperature dependent analysis of three classes of fluorescence spectra from p-6P nanofiber films

    DEFF Research Database (Denmark)

    Balzer, F.; Pogantsch, Alexander; Rubahn, Horst-Günter

    2009-01-01

    Discontinuous nanofiber films of para-hexaphenylene molecules can be routinely fabricated via vacuum deposition on muscovite mica. The fibers emit upon UV illumination blue fluorescence with excitonic spectral peaks. Their intense fluorescence makes them very attractive for the use in photonic de...

  4. Relationship between fluorescence characteristics and molecular weight distribution of natural dissolved organic matter in Lake Hongfeng and Lake Baihua, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Dissolved organic matter (DOM) is one of the most interesting and difficult problems in recent years due to its important functions in the ecological and environmental system and the complexity of its chemical composition and structure. It is well accepted that fluorescence characteristics and molecular weight distribution are two important parameters in the DOM characterization. However, the relationship between them is still unknown. In this study, fluorescence and molecular weight distribution of DOM in Lake Hongfeng, Lake Baihua and their rivers, and their relationship were investigated using the combination of fluorescence spectroscopy and high-performance size exclusion chromatography (HPSEC) with on-line UV absorbance and fluorescence detectors. The results show that there were two obvious humic-like fluorescence peaks (Peaks A and B) in DOM from lake water. But there was another obvious protein-like fluorescence peak (Peak C) in DOM from river water. The humic-like fluorescence material consisted of DOM fraction with smaller molecular weight, ranging from 1.0 to 3.0 kDa, while the protein-like fluorescence material mainly consisted of DOM fraction with MW larger than 2.0 kDa. The calculation of MW using HPSEC was related to the UV absorbance wavelength chosen.

  5. Do asthma patients prefer to monitor symptoms or peak flow?

    Science.gov (United States)

    Harver, Andrew; Humphries, C Thomas; Kotses, Harry

    2009-11-01

    We administered a 65-item survey to patients to assess preference of symptoms and peak flow to detect worsening asthma and to collect information about asthma triggers, asthma knowledge sources, and barriers to peak flow meter use. It was completed by 139 asthma patients. Survey responses were comparable for adult and pediatric patients and for those who owned peak flow meters and those who did not. But patients who owned a peak flow meter reported more severe asthma than others. On average, the patients preferred symptoms to peak flow for assessing worsening asthma. It is likely that the preference for symptom over peak flow monitoring was effort related: Patients preferred symptom monitoring because it was the easier of the two to conduct.

  6. Gamma-ray peak shapes from cadmium zinc telluride detectors

    Energy Technology Data Exchange (ETDEWEB)

    Namboodiri, M.N.; Lavietes, A.D.; McQuaid, J.H.

    1996-09-01

    We report the results of a study of the peak shapes in the gamma spectra measured using several 5 x 5 x 5 mm{sup 3} cadmium zinc telluride (CZT) detectors. A simple parameterization involving a Gaussian and an exponential low energy tail describes the peak shapes sell. We present the variation of the parameters with gamma energy. This type of information is very useful in the analysis of complex gamma spectra consisting of many peaks.

  7. Peak experiences of psilocybin users and non-users.

    Science.gov (United States)

    Cummins, Christina; Lyke, Jennifer

    2013-01-01

    Maslow (1970) defined peak experiences as the most wonderful experiences of a person's life, which may include a sense of awe, well-being, or transcendence. Furthermore, recent research has suggested that psilocybin can produce experiences subjectively rated as uniquely meaningful and significant (Griffiths et al. 2006). It is therefore possible that psilocybin may facilitate or change the nature of peak experiences in users compared to non-users. This study was designed to compare the peak experiences of psilocybin users and non-users, to evaluate the frequency of peak experiences while under the influence of psilocybin, and to assess the perceived degree of alteration of consciousness during these experiences. Participants were recruited through convenience and snowball sampling from undergraduate classes and at a musical event. Participants were divided into three groups, those who reported a peak experience while under the influence of psilocybin (psilocybin peak experience: PPE), participants who had used psilocybin but reported their peak experiences did not occur while they were under the influence of psilocybin (non-psilocybin peak experience: NPPE), and participants who had never used psilocybin (non-user: NU). A total of 101 participants were asked to think about their peak experiences and complete a measure evaluating the degree of alteration of consciousness during that experience. Results indicated that 47% of psilocybin users reported their peak experience occurred while using psilocybin. In addition, there were significant differences among the three groups on all dimensions of alteration of consciousness. Future research is necessary to identify factors that influence the peak experiences of psilocybin users in naturalistic settings and contribute to the different characteristics of peak experiences of psilocybin users and non-users.

  8. Some nonlinear parameters of PP intervals of pulse main peaks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The PP intervals of pulse main peaks from healthy and unhealthy people (arrhythmia) have different nonlinear characteristics. In this paper, the extraction of PP intervals of pulse main peaks is achieved by picking up P peaks of pulse wave with wavelet transform. Furthermore, several nonlinear parameters (correlative dimensions, maximum Lyapunov exponents, complexity and approximate entropy) of the PP intervals of pulse main peaks extracted from normal and unhealthy pulse signals are calculated, with the results showing that these nonlinear parameters calculated from the main wave interval signals are helpful for analyzing human's health state and diagnosing heart diseases.

  9. Peak load pricing in the electric utility industry

    Energy Technology Data Exchange (ETDEWEB)

    Wenders, J.T.

    In the electric utility industry, cost minimization requires that heterogeneous electric generation technologies be used to produce electricity demands of different durations. In contrast to the conclusions of traditional peak-load pricing theory, the existence of a heterogeneous capital stock means that off-peak marginal cost prices almost always should include some marginal capacity costs, and that the profit maximizing regulated electric utility may set peak price above marginal cost and off-peak price below marginal cost in order to encourage the expansion of capital-intensive base load generating capacity. (auth)

  10. Nonlinear preprocessing method for detecting peaks from gas chromatograms

    Directory of Open Access Journals (Sweden)

    Min Hyeyoung

    2009-11-01

    Full Text Available Abstract Background The problem of locating valid peaks from data corrupted by noise frequently arises while analyzing experimental data. In various biological and chemical data analysis tasks, peak detection thus constitutes a critical preprocessing step that greatly affects downstream analysis and eventual quality of experiments. Many existing techniques require the users to adjust parameters by trial and error, which is error-prone, time-consuming and often leads to incorrect analysis results. Worse, conventional approaches tend to report an excessive number of false alarms by finding fictitious peaks generated by mere noise. Results We have designed a novel peak detection method that can significantly reduce parameter sensitivity, yet providing excellent peak detection performance and negligible false alarm rates from gas chromatographic data. The key feature of our new algorithm is the successive use of peak enhancement algorithms that are deliberately designed for a gradual improvement of peak detection quality. We tested our approach with real gas chromatograms as well as intentionally contaminated spectra that contain Gaussian or speckle-type noise. Conclusion Our results demonstrate that the proposed method can achieve near perfect peak detection performance while maintaining very small false alarm probabilities in case of gas chromatograms. Given the fact that biological signals appear in the form of peaks in various experimental data and that the propose method can easily be extended to such data, our approach will be a useful and robust tool that can help researchers highlight valid signals in their noisy measurements.

  11. Adaptive Peak Frequency Estimation Using a Database of PARCOR Coefficients

    Directory of Open Access Journals (Sweden)

    Iiguni Youji

    2005-01-01

    Full Text Available This paper presents an adaptive peak frequency estimation method using a database that stores PARCOR coefficients as key attributes and the corresponding peak frequencies as nonkey attributes. The least-square lattice algorithm is used to recursively estimate the PARCOR coefficients to adapt to changing circumstances. The nearest neighbor to the current PARCOR coefficient is retrieved from the database, and the corresponding peak frequency is regarded as the estimation. A simultaneous execution of database construction and peak estimation with database update is performed to accelerate the processing time and to improve the estimation accuracy.

  12. Peak compression technique in high-performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    WEI YuXia; WANG Lin; XlAO ShengYuan; QING Hong; ZHU Yong; HU GaoFei; DENG YuLin

    2009-01-01

    Peak compression technique based on the difference of the solute migration velocity in two different mobile phases was described theoretically and confirmed using benzaldehyde and 4-hydroxyquinoline (4-HQ) as model compounds.After peak compression,the peak compression factors (the ratio of peak width at half-height under non-compression and that under compression condition) of benzaldehyde and 4-HQ were 0.19 and 0.13,respectively.By this application of the peak compression technique to the mixture,both enhanced peak height and good separation were obtained in one run cycle.This peak compression technique was introduced to determine benzaldehyde from semicarbazide-sensitive amine oxidase-catalyzed enzymetic reaction in order to illustrate the applicability of this technique to the real sample.As a result,the peak was compressed effectively,and 4.94-fold,19.3-fold and 5.74-fold enhancement in peak height,plate number and signal to noise ratio were also achieved,respectively.

  13. Zener Relaxation Peak in an Fe-Cr-Al Alloy

    Institute of Scientific and Technical Information of China (English)

    周正存; 程和法; 宫晨利; 魏健宁; 韩福生

    2002-01-01

    We have studied the temperature spectra of internal friction and relative dynamic modulus of the Fe-(25 wt%)Cr-(5wt%)Al alloy with different grain sizes. It is found that a peak appears in the internal friction versus temperature plot at about 550°C. The peak is of a stable relaxation and is reversible, which occurs not only during heating but also during cooling. Its activation energy is 2.5 (± 0.15) eV in terms of the Arrhenius relation. In addition, the peak is not obvious in specimens with a smaller grain size. It is suggested that the peak originates from Zener relaxation.

  14. Fluorescence spectral studies of Gum Arabic: Multi-emission of Gum Arabic in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dhenadhayalan, Namasivayam, E-mail: ndhena@gmail.com [Department of Chemistry, National Taiwan University, Taipei, Taiwan (China); Mythily, Rajan, E-mail: rajanmythily@gmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India); Kumaran, Rajendran, E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India)

    2014-11-15

    Gum Arabic (GA), a food hydrocolloid is a natural composite obtained from the stems and branches of Acacia Senegal and Acacia Seyal trees. GA structure is made up of highly branched arabinogalactan polysaccharides. Steady-state absorption, fluorescence, and time-resolved fluorescence spectral studies of acid hydrolyzed GA solutions were carried out at various pH conditions. The fluorescence in GA is predominantly attributed to the presence of tyrosine and phenylalanine amino acids. The presence of multi-emissive peaks at different pH condition is attributed to the exposure of the fluorescing amino acids to the aqueous phase, which contains several sugar units, hydrophilic and hydrophobic moieties. Time-resolved fluorescence studies of GA exhibits a multi-exponential decay with different fluorescence lifetime of varying amplitude which confirms that tyrosine is confined to a heterogeneous microenvironment. The existence of multi-emissive peaks with large variation in the fluorescence intensities were established by 3D emission contour spectral studies. The probable location of the fluorophore in a heterogeneous environment was further ascertained by constructing a time-resolved emission spectrum (TRES) and time-resolved area normalized emission spectrum (TRANES) plots. Fluorescence spectral technique is used as an analytical tool in understanding the photophysical properties of a water soluble complex food hydrocolloid containing an intrinsic fluorophore located in a multiple environment is illustrated. - Highlights: • The Manuscript deals with the steady state absorption, emission, fluorescence lifetime and time-resolved emission spectrum studies of Gum Arabic in aqueous medium at various pH conditions. • The fluorescence emanates from the tyrosine amino acid present in GA. • Change in pH results in marked variation in the fluorescence spectral properties of tyrosine. • Fluorescence spectral techniques are employed as a tool in establishing the

  15. Gold nanoparticle-fluorophore complex for conditionally fluorescing signal mediator

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jianting [Department of Chemical Engineering University of, Louisville, KY 40292 (United States); Achilefu, Samuel [Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Nantz, Michael [Department of Chemistry, University of Louisville, Louisville, KY 40292 (United States); Kang, Kyung A., E-mail: kyung.kang@louisville.edu [Department of Chemical Engineering University of, Louisville, KY 40292 (United States)

    2011-06-10

    Fluorescent contrast agents with high specificity and sensitivity are valuable for accurate disease detection and diagnosis. Spherical gold nanoparticles (GNPs) can be smartly utilized for developing highly effective agents. The strong electromagnetic (plasmon) field on their surface can be very effective in influencing the electrons of fluorophores and, thus, manipulating the fluorescence output (i.e., either quenching or enhancement). Fluorescence quenching can be used for negative sensing, or for conditional de-quenching to increase the specificity. Fluorescence enhancement allows sensing to be more sensitive. The level of fluorescence alteration depends on the GNP size, the excitation and emission wavelengths and quantum yield of the fluorophore, and the distance between the GNP and the fluorophore. To understand the mechanisms of the fluorescence change by GNP, we have theoretically analyzed the parameters involved in the fluorescence alteration for commonly used fluorophores, with an emphasis on quenching. The results showed that the fluorescence of fluorophores with the excitation (Ex) and emission (Ex) wavelengths close to the GNP resonance peak tended to be significantly quenched by GNPs. For those fluorophores emitting fluorescence in red or near infrared, to achieve quenching, the distance between GNP and the fluorophore was required to be very short. In general, a shorter distance resulted in more quenching. Bigger GNPs require a shorter distance to achieve the same level of quenching. The fluorescence of a fluorophore with a lower quantum yield (especially the one with emission in far-red or near-infrared) is more difficult to be quenched by GNPs (requires very short distance). Instead, it can be enhanced. Based on the theoretical study, we have developed a near-infrared contrast agent, i.e., Cypate conjugated GNP via a short peptide spacer. Normally the fluorescence of Cypate was quenched. The spacer has a motif of a substrate for urokinase type

  16. Twin peak HF QPOs as a spectral imprint of dual oscillation modes of accretion tori

    CERN Document Server

    Bakala, Pavel; Török, Gabriel; Šrámková, Eva; Abramowicz, Marek A; Vincent, Frederic H; Mazur, Grzegorz P

    2015-01-01

    High frequency (millisecond) quasi-periodic oscillations (HF QPOs) are observed in the X-ray power-density spectra of several microquasars and low mass X-ray binaries. Two distinct QPO peaks, so-called twin peak QPOs, are often detected simultaneously exhibiting their frequency ratio close or equal to 3/2. Following the analytic theory and previous studies of observable spectral signatures, we aim to model the twin peak QPOs as a spectral imprint of specific dual oscillation regime defined by a combination of the lowest radial and vertical oscillation mode of optically thick slender tori with constant specific angular momentum. We examined power spectra and fluorescent K$\\alpha$ iron line profiles for two different simulation setups with the mode frequency relations corresponding to the epicyclic resonance HF QPOs model and modified relativistic precession QPOs model. We use relativistic ray-tracing implemented in parallel simulation code LSDplus. In the background of the Kerr spacetime geometry, we analyze t...

  17. Quantitative analysis for nonlinear fluorescent spectra based on edges matching

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel spectra-edge-matching approach is proposed for the quantitative analysis of the nonlinear fluorescence spectra of the air impurities excited by a femtosecond laser.The fluorescence spectra are first denoised and compressed,both by wavelet transform,and several peak groups are then picked from each spectrum according to a threshold of intensity and are used to extract the spectral features through principal component analysis.It is indicated that the first two principle components actually cover up to 98% of the total information and are sufficient for the final concentration analysis.The analysis reveals a monotone relationship between the spectra intensity and the concentration of the air impurities,suggesting that the femtosecond laser induced fluorescence spectroscopy along with the proposed spectra analysis method can become a powerful tool for monitoring environmental pollutants.

  18. Assessing peak aerobic capacity in Dutch law enforcement officers

    Directory of Open Access Journals (Sweden)

    Harriet Wittink

    2015-06-01

    Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

  19. Assessing peak aerobic capacity in Dutch law enforcement officers.

    Science.gov (United States)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. The peak rate of oxygen consumption (ml×kg-1×min-1) was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA) were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET) in 95% of individuals. None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs) were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg-1×min-1). Normative values for Dutch law enforcement officers were presented. Substantial differences between measured and predicted VO2peak (ml×kg-1×min-1) were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  20. Plasmonic Induced Potential in Metal-Semiconductor Composits

    CERN Document Server

    Shahin, Shiva; Norwood, Robert A

    2015-01-01

    We utilize experimental tools such as conductive atomic force microscopy and electrostatic force microscopy on photo-excited arrays of gold nanoparticles on indium tin oxide substrate. The nanoparticles are partially covered by a thin semiconductor polymer. The change in the current and potential profiles of the composite metal-semiconductor sample after excitation at plasmonic resonance frequency of metallic nanoparticles is analyzed.

  1. Fluorescence enhancement of asCP595 is due to consecutive absorbance of two photons

    Science.gov (United States)

    Savitsky, Alexander P.; Agranat, Michail B.; Lukyanov, Konstantin A.; Schuttrigkeit, Tanja; von Feilitzsch, Till; Kompa, Christian; Michel-Beyerle, Maria-Elisabeth

    2004-06-01

    Colored proteins are widely used as gene markers in biotechnology. Chromophores result from autocatalytic posttranslational reactions involving several amino acids. The protein asCP595 was isolated for the first time from the coral as a weakly fluorescent chromoprotein with a fluorescence maximum at 595 nm. Strong illumination in the blue wing of the low energy absorption band results in a superlinear increase of the fluorescence yield and shifts its fluorescence spectrum by about 10 nm to the red. Time resolved fluorescence measurements using excitation pulses with 10 ps duration revealed a multiexponential decay pattern with time constants in the range from 20 ps to 2.1 ns. The ratio of amplitudes related to the different time constants depends on the intensity of illumination favoring the ns component at high intensities. Transient absorption measurements using ultrashort excitation pulses (150 fs, 1 kHz repetition rate) did not reveal excited states with nanosecond lifetimes as observed in fluorescence upon excitation using 10 ps pulses. This observation leads to the notion that within 10 ps a second photon is absorbed by a state not yet populated within 150 fs. As a consequence we propose two different excited singlet states operative in asCP595, one with low fluorescence quantum yield peaking at 595 nm and one with high fluorescence quantum yield peaking at 605 nm which is populated via the consecutive absorption of two photons at high excitation intensities.

  2. Recognition of edible oil by using BP neural network and laser induced fluorescence spectrum

    Science.gov (United States)

    Mu, Tao-tao; Chen, Si-ying; Zhang, Yin-chao; Guo, Pan; Chen, He; Zhang, Hong-yan; Liu, Xiao-hua; Wang, Yuan; Bu, Zhi-chao

    2013-09-01

    In order to accomplish recognition of the different edible oil we set up a laser induced fluorescence spectrum system in the laboratory based on Laser induced fluorescence spectrum technology, and then collect the fluorescence spectrum of different edible oil by using that system. Based on this, we set up a fluorescence spectrum database of different cooking oil. It is clear that there are three main peak position of different edible oil from fluorescence spectrum chart. Although the peak positions of all cooking oil were almost the same, the relative intensity of different edible oils was totally different. So it could easily accomplish that oil recognition could take advantage of the difference of relative intensity. Feature invariants were extracted from the spectrum data, which were chosen from the fluorescence spectrum database randomly, before distinguishing different cooking oil. Then back propagation (BP) neural network was established and trained by the chosen data from the spectrum database. On that basis real experiment data was identified by BP neural network. It was found that the overall recognition rate could reach as high as 83.2%. Experiments showed that the laser induced fluorescence spectrum of different cooking oil was very different from each other, which could be used to accomplish the oil recognition. Laser induced fluorescence spectrum technology, combined BP neural network,was fast, high sensitivity, non-contact, and high recognition rate. It could become a new technique to accomplish the edible oil recognition and quality detection.

  3. Brain cancer probed by native fluorescence and stokes shift spectroscopy

    Science.gov (United States)

    Zhou, Yan; Liu, Cheng-hui; He, Yong; Pu, Yang; Li, Qingbo; Wang, Wei; Alfano, Robert R.

    2012-12-01

    Optical biopsy spectroscopy was applied to diagnosis human brain cancer in vitro. The spectra of native fluorescence, Stokes shift and excitation spectra were obtained from malignant meningioma, benign, normal meningeal tissues and acoustic neuroma benign tissues. The wide excitation wavelength ranges were used to establish the criterion for distinguishing brain diseases. The alteration of fluorescence spectra between normal and abnormal brain tissues were identified by the characteristic fluorophores under the excitation with UV to visible wavelength range. It was found that the ratios of the peak intensities and peak position in both spectra of fluorescence and Stokes shift may be used to diagnose human brain meninges diseases. The preliminary analysis of fluorescence spectral data from cancer and normal meningeal tissues by basic biochemical component analysis model (BBCA) and Bayes classification model based on statistical methods revealed the changes of components, and classified the difference between cancer and normal human brain meningeal tissues in a predictions accuracy rate is 0.93 in comparison with histopathology and immunohistochemistry reports (gold standard).

  4. Characterisation of estuarine intertidal macroalgae by laser-induced fluorescence

    Science.gov (United States)

    Gameiro, Carla; Utkin, Andrei B.; Cartaxana, Paulo

    2015-12-01

    The article reports the application of laser-induced fluorescence (LIF) for the assessment of macroalgae communities of estuarine intertidal areas. The method was applied for the characterisation of fifteen intertidal macroalgae species of the Tagus estuary, Portugal, and adjacent coastal area. Three bands characterised the LIF spectra of red macroalgae with emission maxima in the ranges 577-583 nm, 621-642 nm and 705-731 nm. Green and brown macroalgae showed one emission maximum in the red region (687-690 nm) and/or one in the far-red region (726-732 nm). Characteristics of LIF emission spectra were determined by differences in the main fluorescing pigments: phycoerythrin, phycocyanin and chlorophyll a (Chl a). In the green and brown macroalgae groups, the relative significance of the two emission maxima seems to be related to the thickness of the photosynthetic layer. In thick macroalgae, like Codium tomentosum or Fucus vesiculosus, the contribution of the far-red emission fluorescence peak was more significant, most probably due to re-absorption of the emitted red Chl a fluorescence within the dense photosynthetic layer. Similarly, an increase in the number of layers of the thin-blade green macroalgae Ulva rigida caused a shift to longer wavelengths of the red emission maximum and the development of a fluorescence peak at the far-red region. Water loss from Ulva's algal tissue also led to a decrease in the red/far-red Chl fluorescence ratio (F685/F735), indicating an increase in the density of chloroplasts in the shrinking macroalgal tissue during low tide exposure.

  5. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue.

    Science.gov (United States)

    Lyndby, Niclas H; Kühl, Michael; Wangpraseurt, Daniel

    2016-05-26

    Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.

  6. Online junction temperature measurement using peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    A new method for junction temperature measurement of MOS-gated power semiconductor switches is presented. The measurement method involves detecting the peak voltage over the external gate resistor of an IGBT or MOSFET during turn-on. This voltage is directly proportional to the peak gate current...

  7. Quality Assurance in the Determination of Overlapping Peak Areas

    DEFF Research Database (Denmark)

    Christensen, L.H.; Heydorn, K.

    1987-01-01

    The ability of different computer programs to yield accurate peak areas in statistical control in the case of partially overlapping photopeaks has been tested by the Analysis of Precision. A modified Covell method, two commercially available peak-fitting programs from Nuclear Data and Ortec, and ...

  8. Psychological Preparation for Peak Performance in Sports Competition

    Science.gov (United States)

    Ohuruogu, Ben; Jonathan, Ugwuanyi I.; Ikechukwu, Ugwu Jude

    2016-01-01

    This paper attempts to make an overview of various techniques, sport psychologist adopt in psychological preparation of athletes for peak performance. To attain peak performance in sports competitions, coaches and athletes should not base their prospect on physical training on sport skills alone rather should integrate both the mental and physical…

  9. Probabilistic peak detection for first-order chromatographic data

    NARCIS (Netherlands)

    Lopatka, M.; Vivó-Truyols, G.; Sjerps, M.J.

    2014-01-01

    We present a novel algorithm for probabilistic peak detection in first-order chromatographic data. Unlike conventional methods that deliver a binary answer pertaining to the expected presence or absence of a chromatographic peak, our method calculates the probability of a point being affected by suc

  10. A rise in peak performance age in female athletes.

    Science.gov (United States)

    Elmenshawy, Ahmed R; Machin, Daniel R; Tanaka, Hirofumi

    2015-06-01

    It was reported in 1980s that ages at which peak performance was observed had remained remarkably stable in the past century, although absolute levels of athletic performance increased dramatically for the same time span. The emergence of older (masters) athletes in the past few decades has changed the demographics and age-spectrum of Olympic athletes. The primary aim of the present study was to determine whether the ages at which peak performance was observed had increased in the recent decades. The data spanning 114 years from the first Olympics (1898) to the most recent Olympics (2014) were collected using the publically available data. In the present study, ages at which Olympic medals (gold, silver, and bronze) were won were used as the indicators of peak performance age. Track and field, swimming, rowing, and ice skating events were analyzed. In men, peak performance age did not change significantly in most of the sporting events (except in 100 m sprint running). In contrast, peak performance ages in women have increased significantly since 1980s and consistently in all the athletic events examined. Interestingly, as women's peak performance age increased, they became similar to men's peak ages in many events. In the last 20-30 years, ages at which peak athletic performance is observed have increased in women but not in men.

  11. Peaked Periodic Wave Solutions to the Broer–Kaup Equation

    Science.gov (United States)

    Jiang, Bo; Bi, Qin-Sheng

    2017-01-01

    By qualitative analysis method, a sufficient condition for the existence of peaked periodic wave solutions to the Broer–Kaup equation is given. Some exact explicit expressions of peaked periodic wave solutions are also presented. Supported by National Nature Science Foundation of China under Grant No. 11102076 and Natural Science Fund for Colleges and Universities in Jiangsu Province under Grant No. 15KJB110005

  12. Deformation Induced Internal Friction Peaks in Nanocrystalline Nickel

    Institute of Scientific and Technical Information of China (English)

    LI Ping-Yun; ZHANG Xi-Yan; NI Hai-Tao; CAO Zhen-Hua; MENG Xiang-Kang

    2012-01-01

    We report the mechanical spectroscopy study of the cold-rolling induced dynamical behavior of crystalline defects in nanocrystalline (NC) nickel. The results show that internal friction (IF) peaks in NC nickel can be induced by cold-rolling. An IF peak, originating from dislocation activity, occurs when the strain is in the range of 9.7-32.8%. Two Bordoni peaks occur when the strain is 39.0% and an IF peak associated with deformation twinning appears when the strain is 42.6%. These results mean that deformation of NC nickel is mediated by different kinds of defects as the strain increases.%We report the mechanical spectroscopy study of the cold-rolling induced dynamical behavior of crystalline defects in nanocrystalline (NC) nickel The results show that internal friction (IF) peaks in NC nickel can be induced by cold-rolling.An IF peak,originating from dislocation activity,occurs when the strain is in the range of 9.7- 32.8%.Two Bordoni peaks occur when the strain is 39.0% and an IF peak associated with deformation twinning appears when the strain is 42.6%.These results mean that deformation of NC nickel is mediated by different kinds of defects as the strain increases.

  13. Fluorescence-Based Sensors

    Science.gov (United States)

    Orellana, Guillermo

    The natural luminescent phenomena (from the Latin words "lumen" and "essentia", i.e., "made of light") such as northern lights (aurora borealis), marine brightness, glow-worms, shining putrid fish scales, "bluish"- appearing water when contained in certain wooden cups (quinine fluorescence), some stones heated at high temperatures with reducing agents (BaS phosphorescence), or light emitted while crushing sugar (triboluminescence) already fascinated our ancestors. Nowadays we understand that ultraviolet and visible emission of light originates from a competitive deactivation pathway of the lowest electronic excited state of atoms and molecules that produces the so called luminescence (the sub-terms fluorescence and phosphorescence just designate whether the return of the excited to the ground state is an "allowed" or "forbidden" process, namely it is fast or slow, the loosely-defined border between them being a 1-μs-1 rate constant). Actually, luminescence is the only method to generate light in the known Universe regardless it is powered by the nuclear reactions in the stars, the ohmical heating in bulbs, an electric discharge, the absorption of light or a (bio)chemical reaction (chemiluminescence).

  14. The TALE Fluorescence Detectors

    Science.gov (United States)

    Jui, Charles

    2009-05-01

    The TALE fluorescence detectors are designed to extend the threshold for fluorescence observation by TA down to 3x10^16 eV. It will comprise two main components. The first is a set of 24 telescopes working in stereo, with an existing TA FD station at ˜6 km separation. These will cover between 3-31 degrees in elevation and have azimuthal coverage maximizing the stereo aperture in the 10^18-10^19 eV energy range. The second component consists of 15 telescopes equipped with 4m diameter mirrors and covering the sky between 31 and 73 degrees in elevation. The larger mirror size pushes the physics threshold down to 3x10^16 eV, and provides view of the shower maximum for the lower energy events. The Tower detector will cover one quadrant in azimuth and operate in hybrid mode with the TALE infill array to provide redundant composition measurements from both shower maximum information and muon-to-electron ratio.

  15. A fluorescence scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Takaaki Kanemaru

    2010-01-01

    Full Text Available Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM and an electron microscope (EM. In the current study, a scanning electron microscope (SEM (JEOL JXA8600 M was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM. In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

  16. OBSERVATION OF ENERGY DISSIPATION PEAK IN POLYSTYRENE MELT ABOVE Tg

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper two different kinds of dynamic mechanical techniques (inversed torsion pendulum and energy dissipation apparatus) were used to study the dynamic behavior of atactic monodisperse polystyrene above glass transition.The plots of energy dissipation versus temperature were presented for two atactic polystyrene samples. An apparent energy dissipation peak occurred above Tg in each plot measured by the inversed torsion pendulum, and simultaneously the sample was found to flow assuredly at the moment. To exclude the influence of the flow and demonstrate there was a peak indeed above Tg, the energy dissipation apparatus was used, in which the samples were put into a cup. An obvious peak appeared,and it was in agreement with the peak observed by the inversed torsion pendulum. On basis of the results measured by the two kinds of apparatus, a conclusion is drawn that a peak occurrs above Tg, which gives a manifestation for the existence of the liquid-liquid transition.

  17. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...... been collected. RESULTS The number of participants per activity is higher during peak hours, which is expected when demand is high. However, the usage of sport floor only differs slightly between peak and low hours. Both during peak and low hours on average 80-100 per cent of floor space is used......BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...

  18. Impact of Smart Grid Technologies on Peak Load to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The IEA's Smart Grids Technology Roadmap identified five global trends that could be effectively addressed by deploying smart grids. These are: increasing peak load (the maximum power that the grid delivers during peak hours), rising electricity consumption, electrification of transport, deployment of variable generation technologies (e.g. wind and solar PV) and ageing infrastructure. Along with this roadmap, a new working paper -- Impact of Smart Grid Technologies on Peak Load to 2050 -- develops a methodology to estimate the evolution of peak load until 2050. It also analyses the impact of smart grid technologies in reducing peak load for four key regions; OECD North America, OECD Europe, OECD Pacific and China. This working paper is a first IEA effort in an evolving modelling process of smart grids that is considering demand response in residential and commercial sectors as well as the integration of electric vehicles.

  19. Arrival Times of Gravitational Radiation Peaks for Binary Inspiral

    CERN Document Server

    Price, Richard H

    2016-01-01

    Modeling of gravitational waves (GWs) from binary black hole inspiral brings together early post-Newtonian waveforms and late quasinormal ringing waveforms. Attempts to bridge the two limits without recourse to numerical relativity involve predicting the time of the peak GW amplitude. This prediction will require solving the question of why the peak of the "source," i.e., the peak of the binary angular velocity, does not correspond to the peak of the GW amplitude. We show here that this offset can be understood as due to the existence two distinct components of the radiation: the "direct" radiation analogous to that in flat spacetime, and "scattered" radiation associated with curved spacetime. The time dependence of these two components, and of their relative phases determines the location of the peak amplitude. We use a highly simplified model to clarify the twocomponent nature of the source, then demonstrate that the explanation is valid also for an extreme mass ratio binary inspiral.

  20. Fluorescence of ceramic color standards.

    Science.gov (United States)

    Koo, Annette; Clare, John F; Nield, Kathryn M; Deadman, Andrew; Usadi, Eric

    2010-04-20

    Fluorescence has been found in color standards available for use in calibration and verification of color measuring instruments. The fluorescence is excited at wavelengths below about 600?nm and emitted above 700?nm, within the response range of silicon photodiodes, but at the edge of the response of most photomultipliers and outside the range commonly scanned in commercial colorimeters. The degree of fluorescence on two of a set of 12 glossy ceramic tiles is enough to introduce significant error when those tiles have been calibrated in one mode of measurement and are used in another. We report the nature of the fluorescence and the implications for color measurement.

  1. DAPI fluorescence in nuclei isolated from tumors.

    Science.gov (United States)

    Krishan, Awtar; Dandekar, Payal D

    2005-08-01

    In DNA histograms of some human solid tumors stained with nuclear isolation medium--4,6-diamidino-2-phenylindole dihydrochloride (NIM-DAPI), the coefficient of variation (CV) of the G0/G1 peak was broad, and in nuclear volume vs DNA scattergrams, a prominent slope was seen. To determine the cause for this, nuclei from frozen breast tumors were stained with NIM-DAPI and analyzed after dilution or resuspension in PBS. In two-color (blue vs red) analysis, most of the slope and broad CV was due to red fluorescence of nuclei stained with NIM-DAPI, which was reduced on dilution or resuspension in PBS, resulting in elimination of the slope and tightening of the CV.

  2. Thermal quenching of fluorescence in condensed media

    Science.gov (United States)

    Lagos, Miguel; Paredes, Rodrigo

    2016-09-01

    Environmental factors strongly affect the features of the electromagnetic spectra of fluorescent compounds hosted by material media. The shape of the absorption and emission peaks, their characteristic asymmetry and breadth, the Stokes shift and quantum yield are generally temperature dependent and heavily influenced by both the local and extended physical properties of the medium. The theoretical method used before to obtain the lineshape function is extended here to other terms of the interaction energy between the optically sensitive orbital and the hosting medium, which become significant when the spectral feature is broad. An analytical expression for the temperature dependent decay rate by non-radiative processes is obtained by this way. Comparison with experiment on thermal quenching gives agreement within the experimental uncertainty. The solvent polarity, its protic or aprotic character, hydrogen bonds, proximity effects and presence of quenchers are expected to enter through the coupling constants of the corresponding energy terms.

  3. Coexistence of Probe Conformations in Lipid Phases—A Polarized Fluorescence Microspectroscopy Study

    OpenAIRE

    Urbančič, Iztok; Ljubetič, Ajasja; Arsov, Zoran; Štrancar, Janez

    2013-01-01

    Several well-established fluorescence methods depend on environment-sensitive probes that report about molecular properties of their local environment. For reliable interpretation of experiments, careful characterization of probes’ behavior is required. In this study, bleaching-corrected polarized fluorescence microspectroscopy with nanometer spectral peak position resolution was applied to characterize conformations of two alkyl chain-labeled 7-nitro-2-1,3-benzoxadiazol-4-yl phospholipids in...

  4. [Excitation-Emission Matrix Fluorescence Spectra Characteristics of DOM in Integrated Verical Flow Constructed Wetland for Treating Eutrophic Water].

    Science.gov (United States)

    Li, Shu-juan; Ge, Li-yun; Deng, Huan-huan

    2015-04-01

    Three-dimensional fluorescence parameters can reflect classification, properties and content change of pollutants in wastewater treatment. In the present paper, by using three-dimensional fluorescence characteristic analysis, comparative analysis of conventional organic pollutants such as COD, TN and TP, and three dimensional fluorescence spectrum analysis, the classification and content of dissolved organic pollutants were identified. We studied fluorescence spectra, fluorescence peak (R. U.), fluorescence index (FI), humification index (HIX) of DOM's four components in the entrance and effluent water and interstitial water, as well as the correlation between these four components and COD, TN and TP. The results showed that the position and intensity of the characteristic fluorescence peak center changed significantly before and after sewage treatment, indicating that the relative composition and content of the organic wastewater varied with wastewater treatment. Furthermore, the test results presented that humic-like composition was not degraded significantly, while protein-like composition was degraded significantly. And the protein-like component and COD, TN and TP presented significant positive correlation. This paper analyzed the fluorescence characteristics changes of dissolved organic matter in sewage treatment by using three-dimensional fluorescence spectrometry, and discussed the feasibility of three-dimensional fluorescence technique applied for description of dissolved organic pollutant degradation rule in the wastewater treatment process.

  5. Red fluorescence in reef fish: A novel signalling mechanism?

    Directory of Open Access Journals (Sweden)

    Siebeck Ulrike E

    2008-09-01

    Full Text Available Abstract Background At depths below 10 m, reefs are dominated by blue-green light because seawater selectively absorbs the longer, 'red' wavelengths beyond 600 nm from the downwelling sunlight. Consequently, the visual pigments of many reef fish are matched to shorter wavelengths, which are transmitted better by water. Combining the typically poor long-wavelength sensitivity of fish eyes with the presumed lack of ambient red light, red light is currently considered irrelevant for reef fish. However, previous studies ignore the fact that several marine organisms, including deep sea fish, produce their own red luminescence and are capable of seeing it. Results We here report that at least 32 reef fishes from 16 genera and 5 families show pronounced red fluorescence under natural, daytime conditions at depths where downwelling red light is virtually absent. Fluorescence was confirmed by extensive spectrometry in the laboratory. In most cases peak emission was around 600 nm and fluorescence was associated with guanine crystals, which thus far were known for their light reflecting properties only. Our data indicate that red fluorescence may function in a context of intraspecific communication. Fluorescence patterns were typically associated with the eyes or the head, varying substantially even between species of the same genus. Moreover red fluorescence was particularly strong in fins that are involved in intraspecific signalling. Finally, microspectrometry in one fluorescent goby, Eviota pellucida, showed a long-wave sensitivity that overlapped with its own red fluorescence, indicating that this species is capable of seeing its own fluorescence. Conclusion We show that red fluorescence is widespread among marine fishes. Many features indicate that it is used as a private communication mechanism in small, benthic, pair- or group-living fishes. Many of these species show quite cryptic colouration in other parts of the visible spectrum. High inter

  6. Fluorescence dynamics of green fluorescent protein in AOT reversed micelles

    NARCIS (Netherlands)

    Uskova, M.A.; Borst, J.W.; Hink, M.A.; Hoek, van A.; Schots, A.; Klyachko, N.L.; Visser, A.J.W.G.

    2000-01-01

    We have used the enhanced green fluorescent protein (EGFP) to investigate the properties of surfactant-entrapped water pools in organic solvents (reversed micelles) with steady-state and time-resolved fluorescence methods. The surfactant used was sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and the

  7. Derived Equivalence Relations of Geometry Skills in Students with Autism: An Application of the PEAK-E Curriculum

    Science.gov (United States)

    Dixon, Mark R.; Belisle, Jordan; Stanley, Caleb R.; Daar, Jacob H.; Williams, Leigh Anne

    2016-01-01

    The present study evaluated the efficacy of equivalence-based instruction (EBI) as described in the PEAK-E curriculum (Dixon, 2015) for promoting the emergence of derived geometry skills in two children with high-functioning autism. The results suggested that direct training of shape name (A) to shape property (B) (i.e., A-B relations) was…

  8. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose

  9. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose po

  10. Generation of sub-nanosecond pulses using peaking capacitor

    Directory of Open Access Journals (Sweden)

    Madhu Palati

    2017-05-01

    Full Text Available This paper discusses the analysis, simulation and design of a peaking circuit comprising of a peaking capacitor, spark gap and load circuit. The peaking circuit is used along with a 200 kV, 20 J Marx generator for generation of sub-nanosecond pulses. A high pressure chamber to accommodate the peaking circuit was designed and fabricated and tested upto a pressure of 70 kg/cm2. Total estimated values of the capacitance and inductance of the peaking circuit are 10 pF and 72 nH respectively. At full charging voltage, the peaking capacitor gets charged to a peak voltage of 394.6 kV in 15 ns. The output switch is closed at this instant. From Analysis & Simulation, the output current & rise time (with a matched load of 85 Ω are 2.53 kA and 0.62 ns.

  11. Peak shift discrimination learning as a mechanism of signal evolution.

    Science.gov (United States)

    Lynn, Spencer K; Cnaani, Jonathan; Papaj, Daniel R

    2005-06-01

    "Peak shift" is a behavioral response bias arising from discrimination learning in which animals display a directional, but limited, preference for or avoidance of unusual stimuli. Its hypothesized evolutionary relevance has been primarily in the realm of aposematic coloration and limited sexual dimorphism. Here, we develop a novel functional approach to peak shift, based on signal detection theory, which characterizes the response bias as arising from uncertainty about stimulus appearance, frequency, and quality. This approach allows the influence of peak shift to be generalized to the evolution of signals in a variety of domains and sensory modalities. The approach is illustrated with a bumblebee (Bombus impatiens) discrimination learning experiment. Bees exhibited peak shift while foraging in an artificial Batesian mimicry system. Changes in flower abundance, color distribution, and visitation reward induced bees to preferentially visit novel flower colors that reduced the risk of flower-type misidentification. Under conditions of signal uncertainty, peak shift results in visitation to rarer, but more easily distinguished, morphological variants of rewarding species in preference to their average morphology. Peak shift is a common and taxonomically widespread phenomenon. This example of the possible role of peak shift in signal evolution can be generalized to other systems in which a signal receiver learns to make choices in situations in which signal variation is linked to the sender's reproductive success.

  12. Infrared absorption peaks in nitrogen doped CZ silicon

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, N. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)]. E-mail: inouen@riast.osakafu-u.ac.jp; Nakatsu, M. [RIAST, Osaka Prefecture University, Gakuen-cho, Sakai, Osaka 599-8570 (Japan); Ono, H. [Japan Fine Ceramics Center, 2-4-3 Nishi-shinbashi, Minato-ku, Tokyo 105-0003 (Japan); JEITA Nitrogen Measurement WG, 3-11 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Inoue, Y. [Tokyo University of Education, Bunkyo-ku, Tokyo 117-0002 (Japan)

    2006-10-15

    Dependences on annealing temperature and nitrogen concentration were examined for new local vibration mode infrared absorption peaks at 856, 973, 984 and 1002 cm{sup -1} in nitrogen-doped CZ silicon crystal. The new absorption peaks were so weak that two sets of samples were examined for temperature and concentration dependences, respectively, to get reliable results. The peak at 1002 cm{sup -1} behaved similarly for annealing, though much weaker, to the known peaks at 810 and 1018 cm{sup -1} which are attributed to interstitial N pair accompanied by the two oxygen interstitials (NNO {sub i}O {sub i}). This suggests that the origin contains 2 O {sub i} also. It was strong in low concentration regime, which is similar to the behavior of shallow thermal donors. This suggests that the structure contains one nitrogen rather than two (N-O interstitial pair). The results were compared with the electronic transition absorption by shallow thermal donors (STD). The absorptions at 1002 and 240 cm{sup -1} behaved similarly. These suggest that the peak at 1002 cm{sup -1} is likely due to NOO {sub i}O {sub i} which is the candidate for STD. The temperature dependence of the other new peaks was slightly different from each other. Origin of the other peaks is not clear yet.

  13. Peak loads and network investments in sustainable energy transitions

    Energy Technology Data Exchange (ETDEWEB)

    Blokhuis, Erik, E-mail: e.g.j.blokhuis@tue.nl [Eindhoven University of Technology, Department of Architecture, Building and Planning, Vertigo 8.11, P.O. Box 513, 5600MB Eindhoven (Netherlands); Brouwers, Bart [Eindhoven University of Technology, Department of Architecture, Building and Planning, Vertigo 8.11, P.O. Box 513, 5600MB Eindhoven (Netherlands); Putten, Eric van der [Endinet, Gas and Electricity Network Operations, P.O. Box 2005, 5600CA Eindhoven (Netherlands); Schaefer, Wim [Eindhoven University of Technology, Department of Architecture, Building and Planning, Vertigo 8.11, P.O. Box 513, 5600MB Eindhoven (Netherlands)

    2011-10-15

    Current energy distribution networks are often not equipped for facilitating expected sustainable transitions. Major concerns for future electricity networks are the possibility of peak load increases and the expected growth of decentralized energy generation. In this article, we focus on peak load increases; the effects of possible future developments on peak loads are studied, together with the consequences for the network. The city of Eindhoven (the Netherlands) is used as reference city, for which a scenario is developed in which the assumed future developments adversely influence the maximum peak loads on the network. In this scenario, the total electricity peak load in Eindhoven is expected to increase from 198 MVA in 2009 to 591-633 MVA in 2040. The necessary investments for facilitating the expected increased peak loads are estimated at 305-375 million Euros. Based upon these projections, it is advocated that - contrary to current Dutch policy - choices regarding sustainable transitions should be made from the viewpoint of integral energy systems, evaluating economic implications of changes to generation, grid development, and consumption. Recently applied and finished policies on energy demand reduction showed to be effective; however, additional and connecting policies on energy generation and distribution should be considered on short term. - Highlights: > Sustainable energy transitions can result in major electricity peak load increases. > Introduction of heat pumps and electrical vehicles requires network expansion. > Under worst case assumptions, peak loads in Eindhoven increase with 200% until 2040. > The necessary investment for facilitating this 2040 peak demand is Euro 305-375 million. > Future policy choices should be made from the viewpoint of the integral energy system.

  14. Fluorescence spectra of atomic ensembles in a magneto-optical trap as an optical lattice

    CERN Document Server

    Yoon, Seokchan; Kang, Sungsam; Kim, Wook-Rae; Kim, Jung-Ryul; An, Kyungwon

    2015-01-01

    We present a study on characteristics of a magneto-optical trap (MOT) as an optical lattice. Fluorescence spectra of atoms trapped in a MOT with a passively phase-stabilized beam configuration have been measured by means of the photon-counting heterodyne spectroscopy. We observe a narrow Rayleigh peak and well-resolved Raman sidebands in the fluorescence spectra which clearly show that the MOT itself behaves as a three-dimensional optical lattice. Optical-lattice-like properties of the phase-stabilized MOT such as vibrational frequencies and lineshapes of Rayleigh peak and Raman sidebands are investigated systematically for various trap conditions.

  15. Phase Dependence of Fluorescence Spectrum of a Two-Level Atom in a Trichromatic Field

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Yan; HU Xiang-Ming; LI Xiao-Xia; SHI Wen-Xing; XU Qing; GUO Hong-Ju

    2005-01-01

    @@ We examine the phase-dependent effects in resonance fluorescence of a two-level atom driven by a trichromatic modulated field. It is shown that the fluorescence spectrum depends crucially on the sum of relative phases of the sideband components compared to the central component, not simply on the respective phases. The appearance or disappearance of the central peak and the selective elimination of the sideband peaks are achieved simply by varying the sum phase. Once the sum phase is fixed, the spectrum keeps its features unchanged regardless of the respective relative phases.

  16. Fluorescence properties of Laurdan in cochleate phases.

    Science.gov (United States)

    Ramani, Karthik; Balasubramanian, Sathyamangalam V

    2003-12-03

    Cochleates are lipid-based delivery system that have found application in drug and gene delivery. They are precipitates, formed as a result of interaction between cations (e.g. Ca2+) and negatively charged phospholipids such as phosphatidylserine (PS). In the present study, we investigated the utility of fluorescent probe Laurdan (6-dodecanoyl-2-dimethylamino naphthalene) to monitor cochleate phase formation. Following addition of Ca2+ to Laurdan labeled lipid vesicles comprised of brain phosphatidylserine (BPS), a significant blue shift in the emission peak maximum of Laurdan was observed and the spectral features were distinct from those observed for the gel and liquid-crystalline (LC) phases. This is consistent with the formation of anhydrous cochleate cylinders that was further confirmed by electron microscopy studies. Due to dipolar relaxation, excitation and emission generalized polarization (GPEx and GPEm) indicate transition from a LC to a rigid and dehydrated (RD) cochleate phase. These spectral changes were utilized to monitor the influence of lipid composition, ionic strength and lamellarity on the formation of cochleate phase. The results indicated that the presence of phosphatidylcholine (PC) and bulk Na+ concentration influenced the formation of cochleate structures from small unilamellar vesicles (SUV) and multilamellar vesicles (MLV) composed of PS. The presence of PC and higher bulk Na+ concentration stabilized the PS vesicles against collapse and total loss of contents, intermediate molecular events in the formation of cochleate structures. From these studies, we conclude that Laurdan fluorescence is a sensitive and a rapid method to detect cochleate phase formation.

  17. Constellation Modification Method for OFDM Peak Power Reduction

    Directory of Open Access Journals (Sweden)

    R V. Orishko

    2011-10-01

    Full Text Available Constellation modification method for OFDM peak power reduction is considered. Choosing function which sum with OFDM symbol gives new symbol with lower peak power is the main idea of method. Signal modification by means of this function carrying out at subcarriers modulation constellation domain. Fourier transform of given function is executing, values obtained for the spectral components are added to the spectral components of the signal and reformed modified OFDM symbol. Main qualities and capabilities for given modification function and different subcarrier modulation methods is analyzed. Obtained plots of peak factor of the coefficients of the algorithm and the algorithm efficiency.

  18. Determination of kinetic energy release from metastable peak widths

    DEFF Research Database (Denmark)

    Petersen, Allan Christian; Sølling, Theis I.

    2017-01-01

    The kinetic energy that is released upon bond rupture is often represented as T1/2. A value that is derived from the FWHM of a fragment peak by the use of two different conversion formulas. The choice of formula depends on whether the peak is recorded by scanning a magnetic sector...... that are obtained from magnet scans compared to the peaks that are obtained by scanning an electrostatic analyzer. The E scans (MIKE experiments) give rise to the same values for both of the employed mass spectrometers. The results are explained in terms of energy defocusing when the reactions take place too far...

  19. Pressure dependence of the Boson peak in poly(butadiene)

    CERN Document Server

    Frick, B

    2002-01-01

    Variation of pressure and temperature in inelastic neutron scattering experiments allows us to separate density and thermal energy contributions. We summarise briefly the influence of pressure and temperature on the dynamic scattering law of the polymer glass former poly(butadiene) far below the glass transition. We also show the advantage of using a liquid-niobium pressure cell in such studies. The effect of pressure on the boson peak is to shift the peak towards higher energies and to reduce the low-frequency modes more strongly below the boson-peak maximum than above. A decrease in the Debye-Waller factor with increasing pressure is observed. (orig.)

  20. Determination of the total absorption peak in an electromagnetic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jia-Hua [Institute of Physics, National Chiao-Tung University, Hsinchu (China); Wang, Zhe, E-mail: wangzhe-hep@mail.tsinghua.edu.cn [Department of Engineering Physics, Tsinghua University, Beijing (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education (China); Lebanowski, Logan [Department of Engineering Physics, Tsinghua University, Beijing (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education (China); Lin, Guey-Lin [Institute of Physics, National Chiao-Tung University, Hsinchu (China); Chen, Shaomin [Department of Engineering Physics, Tsinghua University, Beijing (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education (China)

    2016-08-11

    A physically motivated function was developed to accurately determine the total absorption peak in an electromagnetic calorimeter and to overcome biases present in many commonly used methods. The function is the convolution of a detector resolution function with the sum of a delta function, which represents the complete absorption of energy, and a tail function, which describes the partial absorption of energy and depends on the detector materials and structures. Its performance was tested with the simulation of three typical cases. The accuracy of the extracted peak value, resolution, and peak area was improved by an order of magnitude on average, relative to the Crystal Ball function.

  1. Determination of the total absorption peak in an electromagnetic calorimeter

    CERN Document Server

    Cheng, Jia-Hua; Lebanowski, Logan; Lin, Guey-Lin; Chen, Shaomin

    2016-01-01

    A physically-motivated function was developed to accurately determine the total absorption peak in an electromagnetic calorimeter and to overcome biases present in many commonly used methods. The function is the convolution of a detector resolution function with the sum of a delta function, which represents the complete absorption of energy, and a tail function, which describes the partial absorption of energy and depends on the detector materials and structures. Its performance was tested with the simulation of three typical cases. The accuracy of the extracted peak value, resolution, and peak area was improved by an order of magnitude on average, relative to the Crystal Ball function.

  2. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the National Energy Peak Leveling Program (NEPLP).

  3. Evaluation of peak-picking algorithms for protein mass spectrometry.

    Science.gov (United States)

    Bauer, Chris; Cramer, Rainer; Schuchhardt, Johannes

    2011-01-01

    Peak picking is an early key step in MS data analysis. We compare three commonly used approaches to peak picking and discuss their merits by means of statistical analysis. Methods investigated encompass signal-to-noise ratio, continuous wavelet transform, and a correlation-based approach using a Gaussian template. Functionality of the three methods is illustrated and discussed in a practical context using a mass spectral data set created with MALDI-TOF technology. Sensitivity and specificity are investigated using a manually defined reference set of peaks. As an additional criterion, the robustness of the three methods is assessed by a perturbation analysis and illustrated using ROC curves.

  4. Modeled future peak streamflows in four coastal Maine rivers

    Science.gov (United States)

    Hodgkins, Glenn A.; Dudley, Robert W.

    2013-01-01

    To safely and economically design bridges and culverts, it is necessary to compute the magnitude of peak streamflows that have specified annual exceedance probabilities (AEPs). Annual precipitation and air temperature in the northeastern United States are, in general, projected to increase during the 21st century. It is therefore important for engineers and resource managers to understand how peak flows may change in the future. This report, prepared in cooperation with the Maine Department of Transportation (MaineDOT), presents modeled changes in peak flows at four basins in coastal Maine on the basis of projected changes in air temperature and precipitation. To estimate future peak streamflows at the four basins in this study, historical values for climate (temperature and precipitation) in the basins were adjusted by different amounts and input to a hydrologic model of each study basin. To encompass the projected changes in climate in coastal Maine by the end of the 21st century, air temperatures were adjusted by four different amounts, from -3.6 degrees Fahrenheit (ºF) (-2 degrees Celsius (ºC)) to +10.8 ºF (+6 ºC) of observed temperatures. Precipitation was adjusted by three different percentage values from -15 percent to +30 percent of observed precipitation. The resulting 20 combinations of temperature and precipitation changes (includes the no-change scenarios) were input to Precipitation-Runoff Modeling System (PRMS) watershed models, and annual daily maximum peak flows were calculated for each combination. Modeled peak flows from the adjusted changes in temperature and precipitation were compared to unadjusted (historical) modeled peak flows. Annual daily maximum peak flows increase or decrease, depending on whether temperature or precipitation is adjusted; increases in air temperature (with no change in precipitation) lead to decreases in peak flows, whereas increases in precipitation (with no change in temperature) lead to increases in peak flows. As

  5. Assessing Photosynthesis by Fluorescence Imaging

    Science.gov (United States)

    Saura, Pedro; Quiles, Maria Jose

    2011-01-01

    This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

  6. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  7. Diagnostics of Susabi-nori (Porphyra Yezoensis) by Laser-Induced Fluorescence Method

    Science.gov (United States)

    Okamoto, Tamotsu; Nakamura, Yuki; Takahashi, Kunio; Kaneko, Shohei; Shimada, Yuji

    Susabi-nori (Porphyra yezoensis) was diagnosed by means of laser-induced fluorescence (LIF) method. Fluorescence peaks located at approximately 580, 660, 685 and 720 nm were observed in the LIF spectra of Susabi-nori. In the spectrum of the sample infected with the red rot disease, the intensity of 580 nm peak was relatively high as compared with that of the control sample. On the other hand, the intensities of 580 nm and 660 nm peaks drastically decreased by the influence of the chytrid disease. Furthermore, the intensity of the 580 nm peak increased by dipping into fresh water. These results indicate that LIF spectra of Susabi-nori are affected by the diseases and the stress of fresh water and that the diseases and the stress of Susabi-nori can be diagnosed by the LIF method.

  8. Optical Properties of Fluorescent Dyes

    Institute of Scientific and Technical Information of China (English)

    李戎; 陈东辉

    2001-01-01

    Fluorescent dyes have been widely used these years.Because of the special optical performance, conventional CCM systems seem to be unable to predict the recipes of fabrics dyed with fluorescent dyes. In order to enhance the functions of CCM systems, the optical properties of fluorescent dyes in their absorption region were investigated. It has been found that there was a fixed maximum absorption wavelength for each fluorescent dyes whatever its concentration is. Both absorption region and maximum absorption wavelength of the dyes in solution are the same to those in fabric, and that the absorption is directly proportional to the concentration of the dye. So the optical properties obtained in solutions cna be applied for describing the optics performance of fluorescent dyes in fabrics.

  9. annoPeak: a web application to annotate and visualize peaks from ChIP-seq/ChIP-exo-seq.

    Science.gov (United States)

    Tang, Xing; Srivastava, Arunima; Liu, Huayang; Machiraju, Raghu; Huang, Kun; Leone, Gustavo

    2017-05-15

    We developed annoPeak, a web application to annotate, visualize and compare predicted protein-binding regions derived from ChIP-seq/ChIP-exo-seq experiments using human and mouse cells. Users can upload peak regions from multiple experiments onto the annoPeak server to annotate them with biological context, identify associated target genes and categorize binding sites with respect to gene structure. Users can also compare multiple binding profiles intuitively with the help of visualization tools and tables provided by annoPeak. In general, annoPeak will help users identify patterns of genome wide transcription factor binding profiles, assess binding profiles in different biological contexts and generate new hypotheses. The web service is freely accessible through URL: http://ccc-annopeak.osumc.edu/annoPeak . Source code is available at https://github.com/XingTang2014/annoPeak . gustavo.leone@osumc.edu or kun.huang@osumc.edu. Supplementary data are available at Bioinformatics online.

  10. Brian Eno Hollandi Festivali peakülaliseks

    Index Scriptorium Estoniae

    1999-01-01

    Inglise helilooja, videokunstnik ja muusikaprodutsent Brian Eno on 5.-26. juunini Amsterdamis toimuva avangardse Hollandi Festivali peakülaline, kelle videoinstallatsioon seatakse üles Stedelijki Muuseumis. Festivali programmist

  11. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  12. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  13. Corona discharge ionization of paracetamol molecule: Peak assignment

    Science.gov (United States)

    Bahrami, H.; Farrokhpour, H.

    2015-01-01

    Ionization of paracetamol was investigated using ion mobility spectrometry equipped with a corona discharge ionization source. The measurements were performed in the positive ion mode and three peaks were observed in the ion mobility spectrum. Experimental evidence and theoretical calculations were used to correlate the peaks to related ionic species of paracetamol. Two peaks were attributed to protonated isomers of paracetamol and the other peak was attributed to paracetamol fragment ions formed by dissociation of the N-C bond after protonation of the nitrogen atom. It was observed that three sites of paracetamol compete for protonation and their relative intensities, depending on the sample concentration. The ratio of ion products could be predicted from the internal proton affinity of the protonation sites at each concentration.

  14. Daily peak electricity load forecasting in South Africa using a ...

    African Journals Online (AJOL)

    major source of variation in peak demand forecasting and the inclusion of temperature has a significant ... This definition of electrical demand has its weaknesses. Electrical ..... The coefficient of t is positive, showing a positive linear trend.

  15. Mathematical functions for the representation of chromatographic peaks.

    Science.gov (United States)

    Di Marco, V B; Bombi, G G

    2001-10-05

    About ninety empirical functions for the representation of chromatographic peaks have been collected and tabulated. The table, based on almost 200 references, reports for every function: (1) the most used name; (2) the most convenient equation, with the existence intervals for the adjustable parameters and for the independent variable; (3) the applications; (4) the mathematical properties, in relation to the possible applications. The list includes also equations originally proposed to represent peaks obtained in other analytical techniques (e.g. in spectroscopy), which in many instances have proved useful in representing chromatographic peaks as well; the built-in functions employed in some commercial peak-fitting software packages were included, too. Some of the most important chromatographic functions, i.e. the Exponentially Modified Gaussian, the Poisson, the Log-normal, the Edgeworth/Cramér series and the Gram/Charlier series, have been reviewed and commented in more detail.

  16. Bedrock Geologic Map of the Jay Peak, VT Quadrangle

    Data.gov (United States)

    Vermont Center for Geographic Information — Digital data from VG99-1 Compilation bedrock geologic map of the Jay Peak quadrangle, Compiled by B. Doolan, 1999: VGS Open-File Report VG99-1, 1 plate, scale...

  17. A Second Peak in Diphoton (or Diboson) Resonances

    CERN Document Server

    Carena, Marcela; Ismail, Ahmed; Low, Ian; Shah, Nausheen R; Wagner, Carlos E M

    2016-01-01

    A resonant diphoton peak can be explained by gluon fusion production of a new neutral scalar which subsequently decays into a pair of photons. Loop-induced couplings of the new scalar to gluons and photons should be mediated by particles carrying color and electric charge. We point out that, if the loop particles hadronize before decaying, their bound states will induce a second peak in the diphoton invariant mass spectrum near twice their mass. Using the recently reported 750 GeV excess as a benchmark, we discuss implications of this second peak for resonance searches at the LHC. The second peak could be present for resonances in the $gg$ and $Z\\gamma$ channels, or even in the $WW$ and $ZZ$ channels for a pseudo-scalar resonance, where the couplings are mediated by new loop particles.

  18. Effects of equipment and technique on peak flow measurements

    Directory of Open Access Journals (Sweden)

    O'Driscoll B Ronan

    2006-06-01

    Full Text Available Abstract Background Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients. Methods We studied 36 subjects (PEF range 80–570 l/min. All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique or a forced maximal expiration to residual volume (FVC technique. Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer. Results The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p Conclusion Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.

  19. Modeling and forecasting the peak flows of a river

    Directory of Open Access Journals (Sweden)

    Mario Lefebvre

    2002-01-01

    Full Text Available A stochastic model is found for the value of the peak flows of the Mistassibi river in Québec, Canada, when the river is in spate. Next, the objective is to forecast the value of the coming peak flow about four days in advance, when the flow begins to show a marked increase. Both the stochastic model proposed in the paper and a model based on linear regression are used to produce the forecasts. The quality of the forecasts is assessed by considering the standard errors and the peak criterion. The forecasts are much more accurate than those obtained by taking the mean value of the previous peak flows.

  20. Effect of Gymnema inodorum on postprandial peak plasma glucose ...

    African Journals Online (AJOL)

    USER

    2010-02-15

    Feb 15, 2010 ... on peak plasma glucose concentrations in healthy subjects was investigated. ... fasting plasma glucose and liver function test (AST, ALT, GGT and ALP) .... culture medium was measured using an immunoradiometric assay.

  1. Sakste vara: Eesti peaks õppima Poola kogemusest / Helle Kalda

    Index Scriptorium Estoniae

    Kalda, Helle, 1950-

    2009-01-01

    Poolas on jõutud seisukohale, et Poola riik ei pea Saksamaale ümberasunutele vara tagastama. Riigikogu liikme arvates peaks Eesti mitte kandma kulutusi, vaid hoopis küsima Saksamaalt kompensatsiooni seoses baltisakslaste varaga kantavate kulutuste katteks

  2. Desert Peak East Enhanced Geothermal Systems (EGS) Project

    Energy Technology Data Exchange (ETDEWEB)

    Zemach, Ezra [Ormat Technologies Inc., Reno, NV (United States); Drakos, Peter [Ormat Technologies Inc., Reno, NV (United States); Spielman, Paul [Ormat Technologies Inc., Reno, NV (United States); Akerley, John [Ormat Technologies Inc., Reno, NV (United States)

    2013-09-30

    This manuscript is a draft to replaced with a final version at a later date TBD. A summary of activities pertaining to the Desert Peak EGS project including the planning and resulting stimulation activities.

  3. The effect of gold colloid on the fluorescence spectrum from Safranine T: a physical mechanism based on resonance light scattering.

    Science.gov (United States)

    Li, Jianjun; Zhu, Jian; Zhao, Junwu

    2011-05-01

    The non-monotonic change of fluorescence intensity from Safranine T was observed experimentally by adding gold colloids to the Safranine T aqueous solution. Increasing the content of gold colloids leads to the fluorescence emission peak red shift and increases first and then decreases. We believe that one of the important reasons of the fluorescence changing and shifting is due to the resonance light scattering from gold nanoparticles which is stimulated by the fluorescence of Safranine T and is tunable by the shell thickness of the ST that coated around the gold particles.

  4. Assessment of flood peak simulations by Global Hydrological Models

    OpenAIRE

    Miller, James; Kjeldsen, Thomas; Prudhomme, Christel

    2011-01-01

    With significant changes to flood frequency anticipated as a result of climate change it becomes important to investigate how global hydrological models process climate forcing data. Flood frequency distribution describes the relationship between flood peak magnitude and its return period, indicating the average period of time between exceedance of a certain flood magnitude. The steepness of the distribution (or of the growth curve) is a measure of the variability of the flood peak series. An...

  5. Double-peak Splitting in High-order Harmonics Generation

    Institute of Scientific and Technical Information of China (English)

    WANG Yingsong; LIU Yaqing; YANG Xiaodong; XU Zhizhan

    2000-01-01

    When the intensity of the driving pulse is much higher than the saturation intensity of the media involved, the double-peak splitting in frequency domain emerges in the generated high-order harmonic spectra. The possible origins of this splitting are carefully investigated. The ionization of the gas media and the propagation effect of harmonic field are the main reason for the double-peak splitting observed.

  6. Generation of narrow peaks in spectroscopy of charged particles

    Science.gov (United States)

    Dubbers, Dirk; Schmidt, Ulrich

    2016-11-01

    In spectroscopy of charged particles, narrow peaks may appear in continuous spectra if magnetic transport of the particles is involved. These artefacts, which so far have escaped the attention of investigators, can develop whenever geometric detection efficiency is less than 100%. As such peaks may be misinterpreted as new physics, their generation is investigated, both analytically and experimentally, for various detector configurations, including those used in searches for the spontaneous decay of the vacuum in heavy-ion collisions.

  7. Fluorescence calibration method for single-particle aerosol fluorescence instruments

    Science.gov (United States)

    Shipley Robinson, Ellis; Gao, Ru-Shan; Schwarz, Joshua P.; Fahey, David W.; Perring, Anne E.

    2017-05-01

    Real-time, single-particle fluorescence instruments used to detect atmospheric bioaerosol particles are increasingly common, yet no standard fluorescence calibration method exists for this technique. This gap limits the utility of these instruments as quantitative tools and complicates comparisons between different measurement campaigns. To address this need, we have developed a method to produce size-selected particles with a known mass of fluorophore, which we use to calibrate the fluorescence detection of a Wideband Integrated Bioaerosol Sensor (WIBS-4A). We use mixed tryptophan-ammonium sulfate particles to calibrate one detector (FL1; excitation = 280 nm, emission = 310-400 nm) and pure quinine particles to calibrate the other (FL2; excitation = 280 nm, emission = 420-650 nm). The relationship between fluorescence and mass for the mixed tryptophan-ammonium sulfate particles is linear, while that for the pure quinine particles is nonlinear, likely indicating that not all of the quinine mass contributes to the observed fluorescence. Nonetheless, both materials produce a repeatable response between observed fluorescence and particle mass. This procedure allows users to set the detector gains to achieve a known absolute response, calculate the limits of detection for a given instrument, improve the repeatability of the instrumental setup, and facilitate intercomparisons between different instruments. We recommend calibration of single-particle fluorescence instruments using these methods.

  8. Optical sensing of peroxide using ceria nanoparticles via fluorescence quenching technique

    Science.gov (United States)

    Shehata, Nader; Samir, Effat; Gaballah, Soha; Salah, Mohammed

    2016-07-01

    This study introduces the application of ceria nanoparticles (NPs) as an optical sensor for peroxide using fluorescence quenching technique. Our synthesized ceria NPs have the ability to adsorb peroxides via its oxygen vacancies. Ceria NPs solution with added variable concentrations of hydrogen peroxides is exposed through near-UV excitation and the detected visible fluorescent emission is found to be at ˜520 nm. The fluorescent intensity peak is found to be reduced with increasing the peroxide concentrations due to static fluorescence quenching technique. The relative intensity change of the visible fluorescent emission has been reduced to more than 50% at added peroxide concentrations up to 10 wt. %. In order to increase ceria peroxides sensing sensitivity, lanthanide elements such as samarium (Sm) are used as ceria NPs dopant. This research work could be applied further in optical sensors of radicals in biomedical engineering and environmental monitoring.

  9. Angular shaping of fluorescence from synthetic opal-based photonic crystal.

    Science.gov (United States)

    Boiko, Vitalii; Dovbeshko, Galyna; Dolgov, Leonid; Kiisk, Valter; Sildos, Ilmo; Loot, Ardi; Gorelik, Vladimir

    2015-01-01

    Spectral, angular, and temporal distributions of fluorescence as well as specular reflection were investigated for silica-based artificial opals. Periodic arrangement of nanosized silica globules in the opal causes a specific dip in the defect-related fluorescence spectra and a peak in the reflectance spectrum. The spectral position of the dip coincides with the photonic stop band. The latter is dependent on the size of silica globules and the angle of observation. The spectral shape and intensity of defect-related fluorescence can be controlled by variation of detection angle. Fluorescence intensity increases up to two times at the edges of the spectral dip. Partial photobleaching of fluorescence was observed. Photonic origin of the observed effects is discussed.

  10. In Vivo Imaging of Far-red Fluorescent Proteins after DNA Electrotransfer to Muscle Tissue

    Directory of Open Access Journals (Sweden)

    Hojman Pernille

    2009-04-01

    Full Text Available Abstract DNA electrotransfer to muscle tissue yields long-term, high levels of gene expression; showing great promise for future gene therapy. We want to characterize the novel far-red fluorescent protein Katushka as a marker for gene expression using time domain fluorescence in vivo imaging. Highly efficient transgenic expression was observed after DNA electrotransfer with 100-fold increase in fluorescent intensity. The fluorescent signal peaked 1 week after transfection and returned to background level within 4 weeks. Katushka expression was not as stable as GFP expression, which was detectable for 8 weeks. Depth and 3D analysis proved that the expression was located in the target muscle. In vivo bio-imaging using the novel Katushka fluorescent protein enables excellent evaluation of the transfection efficacy, and spatial distribution, but lacks long-term stability.

  11. Widely tunable, high peak power ultrafast laser sources in biological imaging (Conference Presentation)

    Science.gov (United States)

    Klein, Julien

    2017-02-01

    Widely tunable ultrafast lasers have enabled a large number of biological imaging techniques including point scanning multiphoton excited fluorescence (MPEF), SHG/THG and stimulated Raman imaging. Tunable ultrafast lasers offer spectral agility, covering the entire relative transparency window in live tissue (700-1300nnm) and flexibility with multi-color, synchronized outputs to support sophisticated label free techniques (e.g. stimulated Raman modalities). More recently newly available high peak power lasers based on Ytterbium technology drive advances in two-photon light-sheet, 3 photon excited fluorescence and holographic patterning for optogenetics photo-stimulation. These laser platforms offer a unique blend of compactness, ease of use and cost efficiency, and ideally complement tunable platforms typically based on Ti:Sapphire and IR optical parametric oscillators (OPO). We present various types of ultrafast laser architectures, link their optical characteristics to key bio-imaging requirements, and present relevant examples and images illustrating their impact in biological science. In particular we review the use of ultrafast lasers in optogenetics and fast in-vivo Calcium imaging deep in mouse brain.

  12. Synthesis of photolabile fluorescent polymeric micelles.

    Science.gov (United States)

    Park, Teahoon; You, Jungmok; Oikawa, Hidetoshi; Kim, Eunkyoung

    2014-11-01

    A new amphiphilic block copolymers were synthesized with the atom transfer radical polymerization (ATRP) method. Then, the micelle structures were fabricated with a self-assembly method for application in nanocarriers and sensing. The fluorescent intensity was increased by a factor of 4 in the micelle solution due to more stacked pyrene moieties. The core-shell structure of the micelle was confirmed by HR-TEM images. The pyrene moieties were positioned in the core of the micelle, and the surface consisted of hydrophilic PMMA blocks. The ester bond of the polymer backbone was breakable by irradiation with UV light. Therefore, the micelle structure was deformed after UV irradiation, and the excimer peak was drastically reduced as the monomer peak appeared. The deformation of micelle structures was clearly confirmed by FE-SEM and NMR analysis. These photolabile polymeric micelles may be widely useful for photo-stimulative nanocarriers as well as for the design of new functional micelles with many other chromophores.

  13. Evaluation of Peak-Fitting Software for Gamma Spectrum Analysis

    CERN Document Server

    Zahn, Guilherme S; Moralles, Maurício

    2015-01-01

    In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. There's a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be made in several different ways -- the most common ways are to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with standard sources of $^{137}$Cs, $^{60}$Co, $^{133}$Ba and $^{152}$Eu. The results...

  14. Peak oil: The four stages of a new idea

    Energy Technology Data Exchange (ETDEWEB)

    Bardi, Ugo [Dipartimento di Chimica, Universita di Firenze, Association for the Study of Peak Oil and Gas (ASPO), Polo Scientifico di Sesto Fiorentino, Via della Lastruccia 3, 50019 Sesto Fiorentino (Fi) (Italy)

    2009-03-15

    The present paper reviews the reactions and the path of acceptance of the theory known as ''peak oil''. The theory was proposed for the first time by M.K. Hubbert in the 1950s as a way to describe the production pattern of crude oil. According to Hubbert, the production curve is ''bell shaped'' and approximately symmetric. Hubbert's theory was verified with good approximation for the case of oil production in the United States that peaked in 1971, and is now being applied to the worldwide oil production. It is generally believed that the global peak of oil production (''peak oil'') will take place during the first decade of the 21st century, and some analysts believe that it has already occurred in 2005 or 2006. The theory and its consequences have unpleasant social and economical implications. The present paper is not aimed at assessing the peak date but offers a discussion on the factors that affect the acceptance and the diffusion of the concept of ''peak oil'' with experts and with the general public. The discussion is based on a subdivision of ''four stages of acceptance'', loosely patterned after a sentence by Thomas Huxley. (author)

  15. Peaking of world oil production: Impacts, mitigation, & risk management

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, R.L. (SAIC); Bezdek, Roger (MISI); Wendling, Robert (MISI)

    2005-02-01

    The peaking of world oil production presents the U.S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.... The purpose of this analysis was to identify the critical issues surrounding the occurrence and mitigation of world oil production peaking. We simplified many of the complexities in an effort to provide a transparent analysis. Nevertheless, our study is neither simple nor brief. We recognize that when oil prices escalate dramatically, there will be demand and economic impacts that will alter our simplified assumptions. Consideration of those feedbacks will be a daunting task but one that should be undertaken. Our aim in this study is to-- • Summarize the difficulties of oil production forecasting; • Identify the fundamentals that show why world oil production peaking is such a unique challenge; • Show why mitigation will take a decade or more of intense effort; • Examine the potential economic effects of oil peaking; • Describe what might be accomplished under three example mitigation scenarios. • Stimulate serious discussion of the problem, suggest more definitive studies, and engender interest in timely action to mitigate its impacts.

  16. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea

    KAUST Repository

    Prudkovsky, Andrey A.

    2016-02-03

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  17. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Science.gov (United States)

    Prudkovsky, Andrey A; Ivanenko, Viatcheslav N; Nikitin, Mikhail A; Lukyanov, Konstantin A; Belousova, Anna; Reimer, James D; Berumen, Michael L

    2016-01-01

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  18. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Directory of Open Access Journals (Sweden)

    Andrey A Prudkovsky

    Full Text Available Green Fluorescent Proteins (GFPs have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera found at night time in the southern Red Sea (Saudi Arabia living on shells of the gastropod Nassarius margaritifer (Dunker, 1847 (Neogastropoda: Buccinoidea: Nassariidae. We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  19. Development of near-infrared fluorescent probes for nitric oxide and zinc ion

    Science.gov (United States)

    Kojima, Hirotatsu; Kiyose, Kazuki; Sasaki, Eita; Nishimatsu, Hiroaki; Hirata, Yasunobu; Nagano, Tetsuo

    2007-02-01

    In fluorescence imaging studies of biological mechanisms, cyanine dyes have been employed as fluorescent labels. In particular, tricarbocyanines have the advantage that light at their emission and absorption maxima in the near-infrared (NIR) region around 650-900 nm can penetrate deeply into tissues. We successfully developed two types of cyanine dyes whose fluorescence properties change upon specific reaction with nitric oxide (NO) or zinc ion. The mechanism of fluorescence modulation of the NO probes involves photoinduced electron transfer, and the fluorescent intensity can change at the same wavelengths. We synthesized a series of amine-substituted tricarbocyanines in order to examine the correlation between the electron-donating ability of the amine and the fluorescence peak wavelength. We found that changing the electron-donating ability of the amine substituent altered the absorption and emission wavelengths. Then, we synthesized dipicolylcyanine (DIPCY), consisting of tricarbocyanine as a fluorophore and dipicolylethylenediamine as a heavy metal chelator, and investigated its response to various heavy metal ions. DIPCY can work as a ratiometric fluorescent sensor for zinc ion. This fluorescence modulation of amine-substituted tricarbocyanines should be applicable to dual-wavelength measurement of various biomolecules or enzyme activities. Thus, we have established two mechanisms for modulating the fluorescence properties of cyanines.

  20. New algorithm for MODIS chlorophyll fluorescence height retrieval: performance and comparison with the current product

    Science.gov (United States)

    Ioannou, I.; Zhou, J.; Gilerson, A.; Gross, B.; Moshary, F.; Ahmed, S.

    2009-09-01

    Our previous studies showed that the Fluorescence Line Height (FLH) product, which uses 3 NIR bands at 667, 678, and 746 nm on the MODerate-resolution Imaging Spectroradiometer (MODIS) sensor, and similar bands on MERIS sensor, is not reliable in coastal waters because of a peak in the elastic reflectance spectra which occurs due to the confluence of chlorophyll and water absorption spectra and which overlaps spectrally the chlorophyll fluorescence. This combination of two overlapping peaks makes fluorescence signal retrieval inaccurate. As a consequence, the present FLH algorithm significantly underestimates fluorescence magnitudes in coastal waters. To overcome this problem, we introduce a new and more accurate approach for the retrieval of FLH in turbid waters by the MODIS sensor, which exploits the correlation between the blue-green and red bands reflectance ratios. We show that by making use of the combined remote sensing reflectance's (Rrs) at 488nm, 547nm, 667nm and 678nm we can retrieve fluorescence accurately in case 2 waters even for low fluorescence quantum yield when fluorescence magnitudes are low. The derivation and validation of our algorithm was performed using extensive synthetic datasets which cover a large variability of parameters typical of coastal waters: with CDOM absorption at 400nm 0-2 m-1, mineral concentration 0-5g/m3 and chlorophyll concentration of 0.5-100 mg/m3. In addition, we applied this proposed algorithm to MODIS satellite data and compared it with the traditional FLH algorithm.

  1. Ship-of-opportunity based phycocyanin fluorescence monitoring of the filamentous cyanobacteria bloom dynamics in the Baltic Sea

    Science.gov (United States)

    Seppälä, J.; Ylöstalo, P.; Kaitala, S.; Hällfors, S.; Raateoja, M.; Maunula, P.

    2007-07-01

    Distribution of cyanobacteria cannot be evaluated using chlorophyll a (Chl a) in vivo fluorescence, as most of their Chl a is located in non-fluorescing photosystem I. Phycobilin fluorescence, in turn, is noted as a useful tool in the detection of cyanobacterial blooms. We applied phycocyanin (PC) fluorometer in the monitoring of the filamentous cyanobacterial bloom in the Baltic Sea. For the bloom forming filamentous cyanobacteria Aphanizomenon flos-aquae and Nodularia spumigena, PC fluorescence maximum was identified using the excitation-emission fluorescence matrix. Consequently, the optical setup of our instrument was noted to be appropriate for the detection of PC, and with minor or no interference from Chl a and phycoerythrin fluorescence, respectively. During summer 2005, the instrument was installed on a ferryboat commuting between Helsinki (Finland) and Travemünde (Germany), and data were collected during 32 transects providing altogether 200 000 fluorescence records. PC in vivo fluorescence was compared with Chl ain vivo fluorescence and turbidity measured simultaneously, and with Chl a concentration and biomass of the bloom forming filamentous cyanobacteria determined from discrete water samples. PC fluorescence showed a linear relation to the biomass of the bloom forming filamentous cyanobacteria, and the other sources of PC fluorescence are considered minor in the open Baltic Sea. Estimated by PC fluorescence, cyanobacterial bloom initiated late June at the Northern Baltic Proper, rapidly extended to the central Baltic Proper and the Gulf of Finland, and peaked in the mid-July with values up to 10 mg l -1 (fresh weight). In late July, bloom vanished in most areas. During single transects, or for the whole summer, the variability in Chl a concentrations was explained more by PC fluorescence than by Chl a fluorescence. Thus, filamentous cyanobacteria dominated the overall variability in phytoplankton biomass. Consequently, we show that during the

  2. Single Molecule Spectroscopy of Fluorescent Proteins

    NARCIS (Netherlands)

    Blum, Christian; Subramaniam, Vinod

    2009-01-01

    The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject to intense research. Understanding the

  3. FLEX: fluorescence explorer

    Science.gov (United States)

    Stoll, Marc-Ph.; Court, Andrew; Smorenburg, Kees; Visser, Huib; Crocco, Luiggi; Heilimo, Jyro; Honig, Andre

    1999-12-01

    FLEX is a scientifically driven space mission to provide demonstration/validation of the instrumentation and technique for measuring the natural fluorescence of vegetation in the Fraunhofer lines. The payload consists of high spectral resolution (0.1 - 0.3 nm) CCD imaging grating spectrometer with two channels: one in the red (648 - 664 nm) and one in the blue (391 - 438 nm) for working with several Fraunhofer lines. The across track FOV is 8.4 degrees; ground spatial resolution is better than 0.5 X 0.5 km2. To increase the S/N ratio a steering mirror will be used, if necessary, to 'freeze' the image and also to provide plus or minus 4 degrees across track depointing. Calibration is made by viewing the sun via a diffuser plate switched into the telescope field of view. A separate CCD camera will allow cloud detection and scene identification. A TIR radiometer will provide simultaneous surface temperature measurements. The spacecraft, overall mass estimated at 200 kg, is derived from the ASI-MITA bus which provides all the necessary subsystems and stabilized platform. By use of on-board storage, ground requirements for satellite control and data link are minimized; the possibility of local stations for real time reception/distribution is also envisaged. Provisional orbit characteristics are: LEO sun synchronous, 500 - 900 km altitude. Priority will be given to highest revisit frequency on a sufficient number of selected test sites.

  4. Fluorescent blood cell angiography

    Science.gov (United States)

    Ben-nun, Joshua; Constable, Ian J.

    1994-06-01

    Fluorescein angiography is currently the main method for evaluation of the retinal vascular patency. Ashton noted that capillary patency to the small fluorescein molecule may differ from that of the larger red blood cells. He concluded that fluorescein angiography is not able to demonstrate a developing stenosis, that might be the precipitating cause of a later capillary closure in various microvasculopathies. Sarelius et al have shown, in hamster cheek pouch and cremaster muscle, that fluorescently labeled erythrocytes in known concentrations can be used for the direct measurement of capillary flow parameters. The only assumption that this method relies on, is that the labeled cells are rheologically normal and therefore reflect the behavior of the total cell population. We have developed a new method for an in-vivo, real-time demonstration of the blood cell flow in the retinal capillary net. Based on the assumption presented by Sarelius et al, measurement and analysis of the retinal capillary blood cell flow is also possible from the results achieved by the new method.

  5. Fluorescence endoscopy and photodynamic therapy.

    Science.gov (United States)

    Messmann, H; Endlicher, E; Gelbmann, C M; Schölmerich, J

    2002-10-01

    Fluorescence endoscopy is a new technique which allows a better detection of non-visible malignant or premalignant lesions or, those which are difficult to detect. Exogenously applied sensitisers accumulate selectively in malignant lesions and induce fluorescence after illumination with light of adequate wavelength. However, also endogenous fluorophores, different located in malignant or benign lesions, induce a different autofluorescence in these lesions. Tissue fluorescence can be detected by optical sampling of the mucosa using fluorescence spectroscopy or by generating real time fluorescence images with specialised camera systems. Compared to point fluorescence spectroscopy the latter technique enables the screening of large surface areas of mucosa. Meanwhile, fluorescence endoscopy is a widely used technique in urology employing 5-aminolaevulinic acid sensitisation. In gastroenterology, this technique seems promising for the detection of early cancers or dysplasia in patients with Barrett's oesophagus or ulcerative colitis. Using different sensitisers, photodynamic therapy seems to be a promising option for patients with advanced oesophageal cancer and in the palliative treatment of non-resectable bile duct cancer, furthermore for patients with early gastric cancer and dysplasia in Barrett's oesophagus. Probably, by laser light fractionation or a combination of different sensitisers, an enhanced effect can be expected.

  6. Superoxide dismutase levels and peak expiratory flow in asthmatic children

    Directory of Open Access Journals (Sweden)

    Arie Kurniasih

    2015-09-01

    Full Text Available Background Asthma is a chronic inflammatory process which involve variety of cells such as inflammatory mediators, reactive oxygen species (ROS, and cytokines. The inflammatory process would be exacerbated in the presence of oxidative stress. Superoxide dismutase (SOD is the first important enzyme to protect the respiratory tract against oxidative stress. The decreased of SOD has a correlation with increased of airway obstruction and bronchospasm. Objective To assess for a correlation between superoxide dismutase (SOD levels and peak expiratory flow, as well as to determine the impact of SOD levels for predicting asthma attacks. Methods We conducted a prospective cohort study at Dr. Sardjito Hospital, Yogyakarta, between February and April 2011 involving asthmatic children aged 5-18 years. Subjects’ serum SOD levels and peak expiratory flow were measured at the same time point. We then performed a prospective study following up on the same subjects to find out if they had a recurrent asthma attack within one month of the tests. We also reassessed their peak expiratory flow one month after blood specimens were obtained. Results Thirty-nine patients were enrolled in this study. There was no significant correlation between SOD level and peak expiratory flow [r=0.289; 95%CI -0.025 to 0.47; P=0.074]. However, older age was significantly associated with higher peak expiratory flow (=0.5; 95%CI 3.10 to 11.57; P=0.01. Lower levels of SOD increased the risk of asthma attacks in a month following the initial measurements (RR=5.5; 95%CI 1.6 to 18.9; P=0.009. Conclusion Superoxide dismutase (SOD level is not significantly associated with peak expiratory flow. However, we find a relationship between older age and higher peak expiratory flow and a relationship between lower SOD levels and risk of asthma attacks within one month following the tests.

  7. Poor compensatory hyperventilation in morbidly obese women at peak exercise.

    Science.gov (United States)

    Zavorsky, Gerald S; Murias, Juan M; Kim, Do Jun; Gow, Jennifer; Christou, Nicolas V

    2007-11-15

    This study was designed to compare differences in pulmonary gas exchange at rest and at peak exercise in two groups of women: (1) physically active, non-obese women and (2) women with morbid obesity. Fourteen morbidly obese women (body mass index or BMI=49+/-7 kg/m2; peak oxygen consumption or VO2 peak=14+/-2 ml/(kg min)) and 14 physically active non-obese women (BMI=22+/-2 kg/m2; VO2 peak=50+/-6 ml/(kg min)) performed an incremental, ramped exercise test to exhaustion on a cycle ergometer. Arterial blood was sampled at rest and at peak exercise. At rest, the alveolar to arterial oxygen partial pressure difference was 3x higher in the obese women (14+/-10 mmHg) compared to non-obese women (5+/-4 mmHg). Arterial carbon dioxide pressure (PaCO2) was identical in both groups at rest (37+/-4 mmHg). Only the non-obese women showed a decrease in PaCO2 rest to peak exercise (-5+/-3 mmHg). The slope between heart rate and VO2 during exercise was higher in the morbidly obese compared to non-obese women indicating that for the same absolute increase in VO2 a larger increase in heart rate is needed, demonstrating poorer cardiac efficiency in obese women. In conclusion, morbidly obese women have poorer exercise capacity, cardiac efficiency, and compensatory hyperventilation at peak exercise, and poorer gas exchange at rest compared to physically active, non-obese women.

  8. Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

    Directory of Open Access Journals (Sweden)

    Gabriele Grandi

    2013-08-01

    Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

  9. Ns-scale time-resolved laser induced fluorescence imaging for detection of fecal contamination on apples

    Science.gov (United States)

    Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

    2004-11-01

    Our laboratory has been utilizing fluorescence techniques as a potential means for detection of quality and wholesomeness of food products. A system with a short pulse light source such as a laser coupled with a gated detector can be used to harvest fluorescence in ambient light conditions from biological samples with relatively low fluorescence yields. We present a versatile multispectral laser-induced fluorescence (LIF) imaging system capable of ns-scale time resolved fluorescence. The system is equipped with a tunable pulse laser system that emits in the visible range from 410 nm to 690 nm. Ns-scale, time-dependent multispectral fluorescence emissions of apples contaminated with a range of diluted cow feces were acquired. Four spectral bands, F670, F680, F685 and F730, centered near the emission peak wavelengths of the major constituents responsible for the red fluorescence emissions from apples artificially contaminated with cow feces were examined to determine a suitable single red fluorescence band and optimal ns-gate window for detection of fecal contamination on apples. The results based on the ns decay curves showed that 670 nm with 10 nm full width at half maximum (FWHM) at a gate-delay of 4 ns from the laser excitation peak provided the greatest differences in time-dependent fluorescence responses between feces contaminated spots and apples surfaces.

  10. Modulation of a solid-state reversible fluorescent photoswitching based on a controllable photochromic pyrazolones

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hu; Guo, Jixi [Key Laboratory of Material and Technology for Clean Energy, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang (China); Jia, Dianzeng, E-mail: jdz@xju.edu.cn [Key Laboratory of Material and Technology for Clean Energy, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang (China); Guo, Mingxi; Le, Fuhe; Liu, Lang; Wu, Dongling [Key Laboratory of Material and Technology for Clean Energy, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang (China); Li, Feng [State Laboratory of Surface and Interface Science and Technology, School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, Henan (China); University of Texas, M. D. Anderson Cancer Center, Houston, TX 77002 (United States)

    2014-08-15

    A novel solid-state reversible fluorescence photoswitching system (FPS) based on photochromism of photochromic pyrazolones has been developed by employing phosphor Sr{sub 2}P{sub 2}O{sub 7} co-doped with europium ion and chlorine ion (Sr{sub 2}P{sub 2}O{sub 7}–EC) and 1,3-diphenyl-4-(3-chlorobenzal)-5-hydroxypyrazole-4-phenylsemicarbazone (1a) as the fluorescence dye and the photochromic compound, respectively. With carefully selected components, the absorption band of the keto-form photochromic pyrazolones well overlaps with the emission peak of Sr{sub 2}P{sub 2}O{sub 7}–EC. The fluorescence emission intensity of Sr{sub 2}P{sub 2}O{sub 7}–EC is efficiently modulated by the photoisomerization of 1a with controlling the exposure time in the solid state. The fluorescence photoswitching system displayed high fluorescence quenching efficiency and remarkable fatigue resistance. It can be repeated 7 cycles without observable the changes of emission intensity. A fluorescence quenching efficiency can be achieved with a reversible colour change from white to yellow. - Graphical abstract: A novel fluorescence photoswitching system based on doping inorganic fluorescence dye into photochromic pyrazolones was constructed successfully. Its fluorescence emission could be efficiently modulated by the photoisomerization of pyrazolones. - Highlights: • A solid-state fluorescence photoswitching material was prepared. • Photoswitching is due to energy transfer between pyrazolone and fluorescence dye. • It exhibits excellent fluorescence contrast and fatigue resistance in the solid state.

  11. Energy Saving by Chopping off Peak Demand Using Day Light

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Maitra

    2011-08-01

    Full Text Available An artificial intelligent technique has been implemented in this research using real time datas to calculate how much energy can be chopped from peak load demand. The results are based on real time data that are taken from power delivering centers. These datas do reflect the present condition of power and a solution to those critical conditions during the peak period. These are done in such a way such that helps in judicious scheduling of load. The time based load scheduling has been done so as to understand the basic criteria for solving power crisis during morning peak and early evening peak. The sunray availability and percentage of load that will use day light saving (DLS technique has been taken into account in this work. The results shows that about 0.5% to 1% of load can be shedded off from the peak load period which otherwise is reduction of power. Thus it otherwise also means that an equivalent amount of energy is saved which amounts to a large saving of national money. This result is obtained on monthly and even daily basis. Thus this paper justifies DLS gives a new renewable technique to save energy.

  12. Variable threshold method for ECG R-peak detection.

    Science.gov (United States)

    Kew, Hsein-Ping; Jeong, Do-Un

    2011-10-01

    In this paper, a wearable belt-type ECG electrode worn around the chest by measuring the real-time ECG is produced in order to minimize the inconvenient in wearing. ECG signal is detected using a potential instrument system. The measured ECG signal is transmits via an ultra low power consumption wireless data communications unit to personal computer using Zigbee-compatible wireless sensor node. ECG signals carry a lot of clinical information for a cardiologist especially the R-peak detection in ECG. R-peak detection generally uses the threshold value which is fixed. There will be errors in peak detection when the baseline changes due to motion artifacts and signal size changes. Preprocessing process which includes differentiation process and Hilbert transform is used as signal preprocessing algorithm. Thereafter, variable threshold method is used to detect the R-peak which is more accurate and efficient than fixed threshold value method. R-peak detection using MIT-BIH databases and Long Term Real-Time ECG is performed in this research in order to evaluate the performance analysis.

  13. Pediatric Exercise Testing: Value and Implications of Peak Oxygen Uptake

    Directory of Open Access Journals (Sweden)

    Paolo T. Pianosi

    2017-01-01

    Full Text Available Peak oxygen uptake (peak V ˙ O 2 measured by clinical exercise testing is the benchmark for aerobic fitness. Aerobic fitness, estimated from maximal treadmill exercise, is a predictor of mortality in adults. Peak V ˙ O 2 was shown to predict longevity in patients aged 7–35 years with cystic fibrosis over 25 years ago. A surge of exercise studies in young adults with congenital heart disease over the past decade has revealed significant prognostic information. Three years ago, the first clinical trial in children with pulmonary arterial hypertension used peak V ˙ O 2 as an endpoint that likewise delivered clinically relevant data. Cardiopulmonary exercise testing provides clinicians with biomarkers and clinical outcomes, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response hidden at rest. Momentum from these pioneering observations in multiple disease states should impel clinicians to employ similar methods in other patient populations; e.g., sickle cell disease. Advances in pediatric exercise science will elucidate new pathways that may identify novel biomarkers. Our initial aim of this essay is to highlight the clinical relevance of exercise testing to determine peak V ˙ O 2 , and thereby convince clinicians of its merit, stimulating future clinical investigators to broaden the application of exercise testing in pediatrics.

  14. Rotational and peak torque stiffness of rugby shoes.

    Science.gov (United States)

    Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

    2014-09-01

    Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Pediatric Exercise Testing: Value and Implications of Peak Oxygen Uptake.

    Science.gov (United States)

    Pianosi, Paolo T; Liem, Robert I; McMurray, Robert G; Cerny, Frank J; Falk, Bareket; Kemper, Han C G

    2017-01-24

    Peak oxygen uptake (peak V ˙ O 2 ) measured by clinical exercise testing is the benchmark for aerobic fitness. Aerobic fitness, estimated from maximal treadmill exercise, is a predictor of mortality in adults. Peak V ˙ O 2 was shown to predict longevity in patients aged 7-35 years with cystic fibrosis over 25 years ago. A surge of exercise studies in young adults with congenital heart disease over the past decade has revealed significant prognostic information. Three years ago, the first clinical trial in children with pulmonary arterial hypertension used peak V ˙ O 2 as an endpoint that likewise delivered clinically relevant data. Cardiopulmonary exercise testing provides clinicians with biomarkers and clinical outcomes, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response hidden at rest. Momentum from these pioneering observations in multiple disease states should impel clinicians to employ similar methods in other patient populations; e.g., sickle cell disease. Advances in pediatric exercise science will elucidate new pathways that may identify novel biomarkers. Our initial aim of this essay is to highlight the clinical relevance of exercise testing to determine peak V ˙ O 2 , and thereby convince clinicians of its merit, stimulating future clinical investigators to broaden the application of exercise testing in pediatrics.

  16. Peak alignment using wavelet pattern matching and differential evolution.

    Science.gov (United States)

    Zhang, Zhi-Min; Chen, Shan; Liang, Yi-Zeng

    2011-01-30

    Retention time shifts badly impair qualitative or quantitative results of chemometric analyses when entire chromatographic data are used. Hence, chromatograms should be aligned to perform further analysis. Being inspired and motivated by this purpose, a practical and handy peak alignment method (alignDE) is proposed, implemented in this research for one-way chromatograms, which basically consists of five steps: (1) chromatogram lengths equalization using linear interpolation; (2) accurate peak pattern matching by continuous wavelet transform (CWT) with the Mexican Hat and Haar wavelets as its mother wavelets; (3) flexible baseline fitting utilizing penalized least squares; (4) peak clustering when gap of two peaks is smaller than a certain threshold; (5) peak alignment using differential evolution (DE) to maximize linear correlation coefficient between reference signal and signal to be aligned. This method is demonstrated with both simulated chromatograms and real chromatograms, for example, chromatograms of fungal extracts and Red Peony Root obtained by HPLC-DAD. It is implemented in R language and available as open source software to a broad range of chromatograph users (http://code.google.com/p/alignde).

  17. An online peak extraction algorithm for ion mobility spectrometry data.

    Science.gov (United States)

    Kopczynski, Dominik; Rahmann, Sven

    2015-01-01

    Ion mobility (IM) spectrometry (IMS), coupled with multi-capillary columns (MCCs), has been gaining importance for biotechnological and medical applications because of its ability to detect and quantify volatile organic compounds (VOC) at low concentrations in the air or in exhaled breath at ambient pressure and temperature. Ongoing miniaturization of spectrometers creates the need for reliable data analysis on-the-fly in small embedded low-power devices. We present the first fully automated online peak extraction method for MCC/IMS measurements consisting of several thousand individual spectra. Each individual spectrum is processed as it arrives, removing the need to store the measurement before starting the analysis, as is currently the state of the art. Thus the analysis device can be an inexpensive low-power system such as the Raspberry Pi. The key idea is to extract one-dimensional peak models (with four parameters) from each spectrum and then merge these into peak chains and finally two-dimensional peak models. We describe the different algorithmic steps in detail and evaluate the online method against state-of-the-art peak extraction methods.

  18. Non-Gaussian bias: insights from discrete density peaks

    CERN Document Server

    Desjacques, Vincent; Riotto, Antonio

    2013-01-01

    Corrections induced by primordial non-Gaussianity to the linear halo bias can be computed from a peak-background split or the widespread local bias model. However, numerical simulations clearly support the prediction of the former, in which the non-Gaussian amplitude is proportional to the linear halo bias. To understand better the reasons behind the failure of standard Lagrangian local bias, in which the halo overdensity is a function of the local mass overdensity only, we explore the effect of a primordial bispectrum on the 2-point correlation of discrete density peaks. We show that the effective local bias expansion to peak clustering vastly simplifies the calculation. We generalize this approach to excursion set peaks and demonstrate that the resulting non-Gaussian amplitude, which is a weighted sum of quadratic bias factors, precisely agrees with the peak-background split expectation, which is a logarithmic derivative of the halo mass function with respect to the normalisation amplitude. We point out tha...

  19. Group Elevator Peak Scheduling Based on Robust Optimization Model

    Directory of Open Access Journals (Sweden)

    ZHANG, J.

    2013-08-01

    Full Text Available Scheduling of Elevator Group Control System (EGCS is a typical combinatorial optimization problem. Uncertain group scheduling under peak traffic flows has become a research focus and difficulty recently. RO (Robust Optimization method is a novel and effective way to deal with uncertain scheduling problem. In this paper, a peak scheduling method based on RO model for multi-elevator system is proposed. The method is immune to the uncertainty of peak traffic flows, optimal scheduling is realized without getting exact numbers of each calling floor's waiting passengers. Specifically, energy-saving oriented multi-objective scheduling price is proposed, RO uncertain peak scheduling model is built to minimize the price. Because RO uncertain model could not be solved directly, RO uncertain model is transformed to RO certain model by elevator scheduling robust counterparts. Because solution space of elevator scheduling is enormous, to solve RO certain model in short time, ant colony solving algorithm for elevator scheduling is proposed. Based on the algorithm, optimal scheduling solutions are found quickly, and group elevators are scheduled according to the solutions. Simulation results show the method could improve scheduling performances effectively in peak pattern. Group elevators' efficient operation is realized by the RO scheduling method.

  20. Polysulfone as a scintillation material without doped fluorescent molecules

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hidehito, E-mail: hidehito@rri.kyoto-u.ac.jp [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kitamura, Hisashi [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Sato, Nobuhiro; Kanayama, Masaya [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Shirakawa, Yoshiyuki [Kobe University, 1-1, Rokkodai, Nada, Kobe 657-8501 (Japan); Takahashi, Sentaro [Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

    2015-10-11

    Scintillation materials made from un-doped aromatic ring polymers can be potentially used for radiation detection. Here we demonstrate that Polysulfone (PSU) works without doped fluorescent guest molecules, and thus broadens the choices available for radiation detection. The transparent PSU substrate (1.24 g/cm{sup 3}) significantly absorbs short-wavelength light below approximately 350 nm. Visible light absorption colours the substrate slightly yellow, and indigo blue fluorescence is emitted. The fluorescence maximum occurs at the intersection of the 340-nm excitation and 380-nm emission spectra; thus the emission is partially absorbed by the substrate. An effective refractive index of 1.70 is derived based on the wavelength dependence of the refractive indices and the emission spectrum. A peak caused by 976-keV internal-conversion electrons from a {sup 207}Bi radioactive source appears in the light yield distribution. The light yield is equivalent to that of poly (phenyl sulfone), which has a similar structure. Overall, un-doped PSU could be a component substrate in polymer blends and be used as an educational tool in radiation detection. - Highlights: • Polysulfone (PSU) is a scintillation material that does not require doping. • PSU is slightly yellow. • Indigo blue light with 380-nm emission maximum is emitted. • An effective refractive index of 1.70 was derived. • A peak caused by mono-energetic internal-conversion electrons appears in the light yield distribution.

  1. Fluorescence spectroscopy of fulvic acids from fen peatlands

    Science.gov (United States)

    Maryganova, Victoria; Wojciech Szajdak, Lech

    2010-05-01

    Intensive cultivation and agricultural use of peatlands lead to the degradation and mineralization of peat. Fulvic acids (FA) as the most mobile part of peat organic matter can be considered as an early indicator of its changes. One of the most sensitive and simple methods for studying the structural chemistry of humic substances is fluorescence spectroscopy. The objective of this study was to analyze comparatively the fluorescence properties of FA from low-moor peats of different genesis and decomposition degree with respect to the peculiarities of their chemical structure. FA were isolated from 4 peat samples collected from different fen peatlands of Belarus. Fluorescence spectra were obtained on water solutions of FA at a concentration of 50 mg/L after adjustment to pH=2, 6 and 13 on a MSL-4800 spectrofluorimeter (Perkin Elmer, USA.) at 20 ± 2 oC. Emission spectra were obtained using an excitation wavelength of 365 nm. Excitation spectra were recorded by varying the excitation wavelength from 260 to 520 nm and measuring the fluorescence emission at a fixed wavelength of 520 nm. Elemental composition of FA and optical density at 465 nm (D465) of FA solutions in 0.1 N NaOH were determined. Emission spectra of FA are characterized by a broad featureless band of the maximum wavelengths at λ=460-475 nm. Excitation spectra of FA have three peaks localized in different wavelength regions. The maximum wavelengths and intensities of the excitation peaks depend on the pH values. The highest intensities are observed at pH=6. FA exhibit a main excitation peak at λ=355-370 nm, a minor peak at λ=395-400 nm, and a weak band at λ=430-440 nm. At pH=2, all the peaks decrease in intensity. With increasing the pH to 13, the excitation maximum at λ=355-370 nm shifts from 10 to 20 nm towards longer wavelengths compared to acidic solutions. A general decrease in fluorescence intensity is observed, the intensity decline of the peak at λ=355-370 nm being more marked than of the

  2. Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas

    Science.gov (United States)

    Waltemeyer, Scott D.

    2008-01-01

    Estimates of the magnitude and frequency of peak discharges are necessary for the reliable design of bridges, culverts, and open-channel hydraulic analysis, and for flood-hazard mapping in New Mexico and surrounding areas. The U.S. Geological Survey, in cooperation with the New Mexico Department of Transportation, updated estimates of peak-discharge magnitude for gaging stations in the region and updated regional equations for estimation of peak discharge and frequency at ungaged sites. Equations were developed for estimating the magnitude of peak discharges for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years at ungaged sites by use of data collected through 2004 for 293 gaging stations on unregulated streams that have 10 or more years of record. Peak discharges for selected recurrence intervals were determined at gaging stations by fitting observed data to a log-Pearson Type III distribution with adjustments for a low-discharge threshold and a zero skew coefficient. A low-discharge threshold was applied to frequency analysis of 140 of the 293 gaging stations. This application provides an improved fit of the log-Pearson Type III frequency distribution. Use of the low-discharge threshold generally eliminated the peak discharge by having a recurrence interval of less than 1.4 years in the probability-density function. Within each of the nine regions, logarithms of the maximum peak discharges for selected recurrence intervals were related to logarithms of basin and climatic characteristics by using stepwise ordinary least-squares regression techniques for exploratory data analysis. Generalized least-squares regression techniques, an improved regression procedure that accounts for time and spatial sampling errors, then were applied to the same data used in the ordinary least-squares regression analyses. The average standard error of prediction, which includes average sampling error and average standard error of regression, ranged from 38 to 93 percent

  3. Pre-Peak and Post-Peak Rock Strain Characteristics During Uniaxial Compression by 3D Digital Image Correlation

    Science.gov (United States)

    Munoz, H.; Taheri, A.; Chanda, E. K.

    2016-07-01

    A non-contact optical method for strain measurement applying three-dimensional digital image correlation (3D DIC) in uniaxial compression is presented. A series of monotonic uniaxial compression tests under quasi-static loading conditions on Hawkesbury sandstone specimens were conducted. A prescribed constant lateral-strain rate to control the applied axial load in a closed-loop system allowed capturing the complete stress-strain behaviour of the rock, i.e. the pre-peak and post-peak stress-strain regimes. 3D DIC uses two digital cameras to acquire images of the undeformed and deformed shape of an object to perform image analysis and provides deformation and motion measurements. Observations showed that 3D DIC provides strains free from bedding error in contrast to strains from LVDT. Erroneous measurements due to the compliance of the compressive machine are also eliminated. Furthermore, by 3D DIC technique relatively large strains developed in the post-peak regime, in particular within localised zones, difficult to capture by bonded strain gauges, can be measured in a straight forward manner. Field of strains and eventual strain localisation in the rock surface were analysed by 3D DIC method, coupled with the respective stress levels in the rock. Field strain development in the rock samples, both in axial and shear strain domains suggested that strain localisation takes place progressively and develops at a lower rate in pre-peak regime. It is accelerated, otherwise, in post-peak regime associated with the increasing rate of strength degradation. The results show that a major failure plane, due to strain localisation, becomes noticeable only long after the peak stress took place. In addition, post-peak stress-strain behaviour was observed to be either in a form of localised strain in a shearing zone or inelastic unloading outside of the shearing zone.

  4. Maximizing utilization of sport halls during peak hours

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård; Forsberg, Peter

    the number of participants 7.5 persons higher pr. activity compared to club activities. This implies that clubs during peak hours could include more participants. Another possibility to increase utilization is if the management of sport facilities forced sport clubs and other organisers to adapt......BACKGROUNDDuring peak hours (4.30pm-8pm) demand for timeslots in sport halls in Denmark are high and there are few timeslots available. Further, focus on how public resources are spent most efficient is increasing (Iversen, 2013). This makes it interesting to analyse how utilization could...... be increased during peak hours. DATA AND METHODOLOGYData is collected by observation of activities during two weeks on for example whether halls are used or not; the amount of playing field used; and number of participants (Iversen, 2012). Data on 1.331 activities in 36 sport halls across 4 municipalities have...

  5. The Peak/Dip Picture of the Cosmic Web

    Science.gov (United States)

    Rossi, Graziano

    2016-10-01

    The initial shear field plays a central role in the formation of large-scale structures, and in shaping the geometry, morphology, and topology of the cosmic web. We discuss a recent theoretical framework for the shear tensor, termed the `peak/dip picture', which accounts for the fact that halos/voids may form from local extrema of the density field - rather than from random spatial positions; the standard Doroshkevich's formalism is generalized, to include correlations between the density Hessian and shear field at special points in space around which halos/voids may form. We then present the `peak/dip excursion-set-based' algorithm, along with its most recent applications - merging peaks theory with the standard excursion set approach.

  6. The structure of Doppler peaks induced by active perturbations

    CERN Document Server

    Magueijo, J; Ferreira, P; Coulson, D; Magueijo, Joao; Albrecht, Andreas; Ferreira, Pedro; Coulson, David

    1996-01-01

    We investigate how the qualitative structure of Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy is affected by basic assumptions going into theories of structure formation. We define the concepts of ``coherent'' and ``incoherent'' fluctuations, and also of ``active'' and ``passive'' fluctuations. In these terms inflationary fluctuations are passive and coherent while topological defects are active incoherent fluctuations. Causality and scale invariance are shown to have different implementations in theories differing in the above senses. We then extend the formalism of Hu and Sugiyama to treat models with cosmic defects. Using this formalism we show that the existence or absence of secondary Doppler peaks and the rough placing of the primary peak are very sensitive to the fundamental properties defined. We claim therefore that even a rough measurement of the angular power spectrum C_l shape at 100

  7. Weak Lensing Peak Finding: Estimators, Filters, and Biases

    CERN Document Server

    Schmidt, Fabian

    2010-01-01

    Large catalogs of shear-selected peaks have recently become a reality. In order to properly interpret the abundance and properties of these peaks, it is necessary to take into account the effects of the clustering of source galaxies, among themselves and with the lens. In addition, the preferred selection of lensed galaxies in a flux- and size-limited sample leads to fluctuations in the apparent source density which correlate with the lensing field (lensing bias). In this paper, we investigate these issues for two different choices of shear estimators which are commonly in use today: globally-normalized and locally-normalized estimators. While in principle equivalent, in practice these estimators respond differently to systematic effects such as lensing bias and cluster member dilution. Furthermore, we find that which estimator is statistically superior depends on the specific shape of the filter employed for peak finding; suboptimal choices of the estimator+filter combination can result in a suppression of t...

  8. Mercer County off-peak fare-free bus demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Dommasch, I.N.; Hollinger, R.L.

    1979-07-01

    A system-wide, off-peak fare-free bus demonstration project is being conducted in Mercer County, New Jersey to study effects of fare-free bus operation. Data collected for 2 1/2 months of operation are presented. Since implementation of the fare-free service, Mercer Metro off-peak ridership has increased approximately 45 to 50%. This equates to an overall system-wide ridership increase of about 10 to 15%. One effect of the fare-free operation has been to increase bus run times, caused in part by accompanying increases in the occurrence and length of bus delays in the downtown area. The percentage of filled bus seats has changed from about 10% before the demonstration, to over 50% after the off-peak fares were eliminated.

  9. The Peak Pairs algorithm for strain mapping from HRTEM images

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, Pedro L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)], E-mail: pedro.galindo@uca.es; Kret, Slawomir [Institute of Physics, PAS, AL. Lotnikow 32/46, 02-668 Warsaw (Poland); Sanchez, Ana M. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Laval, Jean-Yves [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, Paris (France); Yanez, Andres; Pizarro, Joaquin; Guerrero, Elisa [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain); Ben, Teresa; Molina, Sergio I. [Departamento de Ciencia de los Materiales e Ing. Metalurgica y Q. Inorganica, Facultad de Ciencias, Universidad de Cadiz, Pol. Rio San Pedro s/n. 11510, Puerto Real, Cadiz (Spain)

    2007-11-15

    Strain mapping is defined as a numerical image-processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. Algorithms to map elastic strains from high-resolution transmission electron microscopy (HRTEM) images may be classified into two categories: those based on the detection of peaks of intensity in real space and the Geometric Phase approach, calculated in Fourier space. In this paper, we discuss both categories and propose an alternative real space algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in an affine transformed space dependent on the reference area. In spite of the fact that it is a real space approach, the Peak Pairs algorithm exhibits good behaviour at heavily distorted defect cores, e.g. interfaces and dislocations. Quantitative results are reported from experiments to determine local strain in different types of semiconductor heterostructures.

  10. COPAR: A ChIP-Seq Optimal Peak Analyzer

    Directory of Open Access Journals (Sweden)

    Binhua Tang

    2017-01-01

    Full Text Available Sequencing data quality and peak alignment efficiency of ChIP-sequencing profiles are directly related to the reliability and reproducibility of NGS experiments. Till now, there is no tool specifically designed for optimal peak alignment estimation and quality-related genomic feature extraction for ChIP-sequencing profiles. We developed open-sourced COPAR, a user-friendly package, to statistically investigate, quantify, and visualize the optimal peak alignment and inherent genomic features using ChIP-seq data from NGS experiments. It provides a versatile perspective for biologists to perform quality-check for high-throughput experiments and optimize their experiment design. The package COPAR can process mapped ChIP-seq read file in BED format and output statistically sound results for multiple high-throughput experiments. Together with three public ChIP-seq data sets verified with the developed package, we have deposited COPAR on GitHub under a GNU GPL license.

  11. Correlation Filter Learning Toward Peak Strength for Visual Tracking.

    Science.gov (United States)

    Sui, Yao; Wang, Guanghui; Zhang, Li

    2017-04-13

    This paper presents a novel visual tracking approach to correlation filter learning toward peak strength of correlation response. Previous methods leverage all features of the target and the immediate background to learn a correlation filter. Some features, however, may be distractive to tracking, like those from occlusion and local deformation, resulting in unstable tracking performance. This paper aims at solving this issue and proposes a novel algorithm to learn the correlation filter. The proposed approach, by imposing an elastic net constraint on the filter, can adaptively eliminate those distractive features in the correlation filtering. A new peak strength metric is proposed to measure the discriminative capability of the learned correlation filter. It is demonstrated that the proposed approach effectively strengthens the peak of the correlation response, leading to more discriminative performance than previous methods. Extensive experiments on a challenging visual tracking benchmark demonstrate that the proposed tracker outperforms most state-of-the-art methods.

  12. Peaks in the Cosmic Microwave Background flat versus open models

    CERN Document Server

    Barreiro, R B; Martínez-González, E; Cayon, L; Silk, J; Silk, Joseph

    1996-01-01

    We present properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We obtain analytical expressions of several topological descriptors: mean number of maxima and the probability distribution of the gaussian curvature and the eccentricity of the peaks. These quantities are calculated as functions of the radiation power spectrum, assuming a gaussian distribution of temperature anisotropies. We present results for angular resolutions ranging from 5' to 20' (antenna FWHM), scales that are relevant for the MAP and COBRAS/SAMBA space missions and the ground-based interferometer experiments. Our analysis also includes the effects of noise. We find that the number of peaks can discriminate between standard CDM models, and that the gaussian curvature distribution provides a useful test for these various models, whereas the eccentricity distribution can not distinguish between them.

  13. Is the baryon acoustic oscillation peak a cosmological standard ruler?

    CERN Document Server

    Roukema, Boudewijn F; Fujii, Hirokazu; Ostrowski, Jan J

    2016-01-01

    In the standard model of cosmology, the Universe is static in comoving coordinates; expansion occurs homogeneously and is represented by a global scale factor. The baryon acoustic oscillation (BAO) peak location is a statistical tracer that represents, in the standard model, a fixed comoving-length standard ruler. Recent gravitational collapse should modify the metric, rendering the effective scale factor, and thus the BAO standard ruler, spatially inhomogeneous. Using the Sloan Digital Sky Survey, we show to high significance (P < 0.001) that the spatial compression of the BAO peak location increases as the spatial paths' overlap with superclusters increases. Detailed observational and theoretical calibration of this BAO peak location environment dependence will be needed when interpreting the next decade's cosmological surveys.

  14. Zero-bias peak splitting in InSb nanowires

    Science.gov (United States)

    Chen, Jun; Yu, Peng; Hocevar, Moïra; Plissard, Sébastien; Car, Diana; Bakkers, Erik; Frolov, Sergey

    2015-03-01

    Zero-bias conductance peak(ZBP) has been reported as a signature of Majorana fermions in InSb nanowires. Other features like ZBP phase diagram in chemical potential vs magnetic field and peak splitting are proposed as additional evidences of Majorana fermions. We make superconductor-InSb nanowire hybrid devices with the aim of exploring these features and beyond. By means of high-k HfOx as the dielectric layer, we obtain large gate-tunability of chemical potential, which may enable us to map out ZBP phase diagram. Here we report observation of ZBP at finite magnetic field. Such peak is tunable with gates underneath the superconductor. In particular, it splits and merges again as a function of the center gate. We study such splitting in the context of a pair of coupled Majorana bound states.

  15. Modular generation of fluorescent phycobiliproteins.

    Science.gov (United States)

    Wu, Xian-Jun; Chang, Kun; Luo, Juan; Zhou, Ming; Scheer, Hugo; Zhao, Kai-Hong

    2013-06-01

    Phycobiliproteins are brightly-fluorescent light-harvesting pigments for photosynthesis in cyanobacteria and red algae. They are also of interest as fluorescent biomarkers, but their heterologous generation in vivo has previously required multiple transformations. We report here a modular approach that requires only two DNA segments. The first codes for the apo-protein. The second codes for fusions capable of chromophore biosynthesis and its covalent attachment to the apo-protein; it contains the genes of heme oxygenase, a bilin reductase, and a chromophore lyase. Phycobiliproteins containing phycoerythrobilin (λ(fluor) ~ 560 nm), phycourobilin (λ(fluor) ~ 500 nm), phycocyanobilin (λ(fluor) ~ 630 nm) or phycoviolobilin (λ(fluor) ~ 580 nm) were obtained in high yield in E. coli. This approach facilitates chromophorylation studies of phycobiliproteins, as well as their use for fluorescence labeling based on their high fluorescence.

  16. Fluorescence diagnosis in tissue injury

    Science.gov (United States)

    Maciel, Vitória H.; Ferreira, Juliana; Bagnato, Vanderlei S.

    2009-06-01

    Background and Objectives: The paper aim was to evaluate the efficacy of the fluorescence spectroscopy in the detection of UV-induced skin change of Wistar rats. Study Design/ Materials and Methods: In a group male Wistar rats, the skin damage was produced by an UV-C lamp, periodically monitored using the laser-induced fluorescence, until complete healing process. After determining a characteristic emission band present in the fluorescence spectra of the induced injuries, the amplitude band monitoring allowed the follow up on the injury and the recovery. Results: We observed the appearance of two new emission bands more evident at the injury spectra when compared to the spectrums from normal non-exposed tissue. Following such spectral bands was possible to observe the establishment and recovery. Conclusions: The fluorescence spectroscopy is a promising technique in distinguishing between normal and UV induced skin change helping the evaluation of changes which are irreversible cancer tissue characteristics.

  17. Fluorescent Sensors for Biological Applications

    Directory of Open Access Journals (Sweden)

    Hui-wang Ai

    2014-09-01

    Full Text Available Fluorescence is one of the most important analytical methods used in biological studies. In the past decade or two, instrumentation in this field has greatly advanced, and now it is possible to detect single photons or fluorescent molecules [1,2], or break the Abbe diffraction limit to distinguish two points spaced less than 50 nm apart [3]. Concurrently, the development of improved fluorescent probes, which can be coupled with state-of-the-art instruments, has been equally important. This special issue on “fluorescent biosensors” in Sensors reports recent results from eight research groups in the field of sensor development. It includes three review articles, and six research articles reporting original results. [...

  18. Synthesis and fluorescence studies of nine 1,5-benzodiazepine-2,4-dione derivatives: Dual emission and excimer fluorescence

    Science.gov (United States)

    Qomi, Hamid Reza; Habibi, Azizollah; Shahcheragh, Seyyed Mohammad

    2017-03-01

    The photophysical properties of nine 1,5-benzodiazepine-2,4-dione (BZD) derivatives were investigated using absorption and fluorescence spectral techniques in dimethyl sulfoxide. The trend of red shifts caused by the substitutions had full compliance with the trend of decreasing the calculated band gap (ΔELUMO-HOMO) by semi-empirical AM1 and DFT/B3LYP/6-311 + G* computational methods. The positive solvatochromism of BZD a demonstrated the π-π* nature of the singlet excited state. Dual fluorescence was observed in the emission spectra of BZD f and g, while their spectrum in different concentration showed only one peak short wavelength (SW) in dilute solutions. The main peak in SW around 370 nm was attributed to the monomer of BZD (f* or g*) and the broader emission shifted to the visible region around 400 nm in middle wavelength (MW) to the intermolecular excimer emission of BZD ([f/f]*or [g/g]*). The observed phenomena, such as solvatochromism, dual fluorescence, some red shifts caused by substitution, and larger Stokes shift indicated the existence of intramolecular charge transfer (ICT) in the BZDs series. The phosphorescence emission of the BZDs demonstrated their intersystem crossing (ISC) process.

  19. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  20. Fe-peak element abundances in disk and halo stars

    CERN Document Server

    Bergemann, Maria

    2009-01-01

    At present none of Galactic chemical evolution (GCE) models provides a self-consistent description of observed trends for all iron-peak elements with metallicity simultaneously. The question is whether the discrepancy is due to deficiencies of GCE models, such as stellar yields, or due to erroneous spectroscopically-determined abundances of these elements in metal-poor stars. The present work aims at a critical reevaluation of the abundance trends for several odd and even-Z Fe-peak elements, which are important for understanding explosive nucleosynthesis in supernovae.

  1. Copernicus crater central peak - Lunar mountain of unique composition

    Science.gov (United States)

    Pieters, C. M.

    1982-01-01

    Olivine is identified as the major mafic mineral in a central peak of Copernicus crater. Information on the mineral assemblages of such unsampled lunar surface material is provided by near infrared reflectance spectra (0.7 to 2.5 micrometers) obtained with earth-based telescopes. The composition of the deep-seated material comprising the Copernicus central peak is unique among measured areas. Other lunar terra areas and the wall of Copernicus exhibit spectral characteristics of mineral assemblages comparable to the feldspathic breccias returned by the Apollo missions, with low-calcium orthopyroxene being the major mafic mineral.

  2. Peak Oil and the Everyday Complexity of Human Progress Narratives

    Directory of Open Access Journals (Sweden)

    John C. Pruit

    2012-11-01

    Full Text Available The “big” story of human progress has polarizing tendencies featuring the binary options of progress or decline. I consider human progress narratives in the context of everyday life. Analysis of the “little” stories from two narrative environments focusing on peak oil offers a more complex picture of the meaning and contours of the narrative. I consider the impact of differential blog site commitments to peak oil perspectives and identify five narrative types culled from two narrative dimensions. I argue that the lived experience complicates human progress narratives, which is no longer an either/or proposition.

  3. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This multisectioned three-Volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of volume III contains appendixes of information on load shedding determination, analysis, socio-economic study, contractual cross references, and definitions.

  4. Thermal conductivity peaks in old and new ceramic superconductors

    Science.gov (United States)

    Williams, Wendell S.

    1993-07-01

    A sharp peak in the thermal conductivity curve of high Tc ceramic superconductors below Tc found by many workers is compared with a similar but even larger effect found earlier for niobium carbide — an older ceramic superconductor — by Radosevich and Williams. The interpretation of this peak given in the literature for the high Tc materials — reduced phonon-electron scattering below Tc as the superconducting energy gap opens — is the same as that established earlier for niobium carbide, which can be treated by BCS/BRT theory, thus lending support to this view. The role of point defects (vacancies) in both materials is also emphasized.

  5. New explanation of Raman peak redshift in nanoparticles

    Science.gov (United States)

    Meilakhs, A. P.; Koniakhin, S. V.

    2017-10-01

    In this letter, we propose a new model that explains the Raman peak downshift observed in nanoparticles with respect to bulk materials. The proposed model takes into account discreteness of the vibrational spectra of nanoparticles. For crystals with a cubic lattice (Diamond, Silicon, Germanium) we give a relation between the displacement of Raman peak position and the size of nanoparticles. The proposed model does not include any uncertain parameters, unlike the conventionally used phonon confinement model (PCM), and can be employed for unambiguous nanoparticles size estimation.

  6. Peak metamorphic temperatures from cation diffusion zoning in garnet

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik; Mezger, Klaus

    2013-01-01

    A model that relates the characteristic diffusion length and average cooling rate to peak temperature was developed for chemical diffusion in spherical geometries on the basis of geospeedometry principles and diffusion theory. The model is quantitatively evaluated for cation diffusion profiles in...... is robust and provides a reliable means of estimating peak temperatures for different types of high-grade metamorphic rock. The tool could be of particular advantage in rocks where critical assemblages for conventional thermometry do not occur or have been replaced during retrogression....

  7. Peak heart rate decreases with increasing severity of acute hypoxia

    DEFF Research Database (Denmark)

    Lundby, C; Araoz, M; Van Hall, Gerrit

    2001-01-01

    The purpose of the present study was to investigate the degree to which peak heart rate is reduced during exhaustive exercise in acute hypoxia. Five sea-level lowlanders performed maximal exercise at normobaric normoxia and at three different levels of hypobaric hypoxia (barometric pressures of 518......, 459, and 404 mmHg) in a hypobaric chamber and while breathing 9% O(2) in N(2). These conditions were equivalent to altitudes of 3300, 4300, 5300, and 6300 m above sea level, respectively. At 4300 m, maximal exercise was also repeated after 4 and 8 h. Peak heart rate (HR) decreased from 191 (182...

  8. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program for computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. The report consists of the following three volumes: Volume I: management overview; Volume II: methodology and technology; and Volume III; appendices.

  9. National energy peak leveling program (NEPLP). Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This three-volume report is responsive to the requirements of Contract E (04-3)-1152 to provide a detailed methodology, to include management, technology, and socio-economic aspects, of a voluntary community program of computer-assisted peak load leveling and energy conservation in commercial community facilities. The demonstration project established proof-of-concept in reducing the kW-demand peak by the unofficial goal of 10%, with concurrent kWh savings. This section of the three volume report is a final report appendix with information on the financial management of load leveling, audit procedures, and building operating profiles.

  10. Quasispecies evolution on a fitness landscape with a fluctuating peak

    Science.gov (United States)

    Nilsson, Martin; Snoad, Nigel

    2002-03-01

    A quasispecies evolving on a fitness landscape with a single peak of fluctuating height is studied. In the approximation that back mutations can be ignored, the rate equations can be solved analytically. It is shown that the error threshold on this class of dynamic landscapes is defined by the time average of the selection pressure. In the case of a periodically fluctuating fitness peak, we also study the phase shift and response amplitude of the previously documented low-pass filter effect. The special case of a small harmonic fluctuation is treated analytically.

  11. A low-toxic artificial fluorescent glycoprotein can serve as an efficient cytoplasmic labeling in living cell.

    Science.gov (United States)

    Si, Jiangju; Liang, Dawei; Kong, Dan; Wu, Sufang; Yuan, Lan; Xiang, Yan; Jiang, Lei

    2015-03-06

    To maintain the virtue of good optical property and discard the dross of conventional fluorescent staining dyes, we provide a strategy for designing new fluorescent scaffolds. In this study, a novel fluorescent labeling glycoprotein (chitosan-poly-L-cysteine, CPC) was synthesized through graft copolymerization. CPC gives emission peak at 465-470 nm when excited at 386 nm. The submicro-scale CPC microspheres could be localized and persisted specifically in the cytoplasm of living cells, with strong blue fluorescence. Moreover, CPC was highly resistant to photo bleaching, the fluorescence was remained stable for up to 72 h as the cells grew and developed. The glycoprotein CPC was bio-compatible and in zero grade cytotoxicity as quantified by MTT assay. The fluorescent labeling process with our newly designed glycoprotein CPC is exceptionally efficient. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Impact Melt Cover on Central Peaks of Complex Craters: Implications for Deriving Crustal Composition

    Science.gov (United States)

    Dhingra, D.; Pieters, C. M.

    2017-05-01

    The use of impact crater central peaks for deriving crustal mineralogy at depth assumes pristine nature of the peaks. Impact melt on several central peaks is evidence for contamination. Central-peaks-derived crustal mineralogy may be affected.

  13. Melanin-originated carbonaceous dots for triple negative breast cancer diagnosis by fluorescence and photoacoustic dual-mode imaging.

    Science.gov (United States)

    Xiao, Wei; Li, Yuan; Hu, Chuan; Huang, Yuan; He, Qin; Gao, Huile

    2017-07-01

    Carbonaceous dots exhibit increasing applications in diagnosis and drug delivery due to excellent photostability and biocompatibility properties. However, relative short excitation and emission of melanin carbonaceous dots (MCDs) limit the applicability in fluorescence bioimaging. Furthermore, the generally poor spatial resolution of fluorescence imaging limits potential in vivo applications. Due to a variety of beneficial properties, in this study, MCDs were prepared exhibiting great potential in fluorescence and photoacoustic dual-mode bioimaging. The MCDs exhibited a long excitation peak at 615nm and emission peak at 650nm, further highlighting the applicability in fluorescence imaging, while the absorbance peak at 633nm renders MCDs suitable for photoacoustic imaging. In vivo, the photoacoustic signal of MCDs was linearly correlated with the concentration of MCDs. Moreover, the MCDs were shown to be taken up into triple negative breast cancer cell line 4T1 in both a time- and concentration-dependent manner. In vivo fluorescence and photoacoustic imaging of subcutaneous 4T1 tumor demonstrated that MCDs could passively target triple negative breast cancer tissue by enhanced permeability and retention effects and may therefore be used for tumor dual-mode imaging. Furthermore, fluorescence distribution in tissue slices suggested that MCDs may distribute in 4T1 tumor with high efficacy. In conclusion, the MCDs studied offer potential application in fluorescence and photoacoustic dual-mode imaging.

  14. Fluorescence lifetimes: fundamentals and interpretations.

    Science.gov (United States)

    Noomnarm, Ulai; Clegg, Robert M

    2009-01-01

    Fluorescence measurements have been an established mainstay of photosynthesis experiments for many decades. Because in the photosynthesis literature the basics of excited states and their fates are not usually described, we have presented here an easily understandable text for biology students in the style of a chapter in a text book. In this review we give an educational overview of fundamental physical principles of fluorescence, with emphasis on the temporal response of emission. Escape from the excited state of a molecule is a dynamic event, and the fluorescence emission is in direct kinetic competition with several other pathways of de-excitation. It is essentially through a kinetic competition between all the pathways of de-excitation that we gain information about the fluorescent sample on the molecular scale. A simple probability allegory is presented that illustrates the basic ideas that are important for understanding and interpreting most fluorescence experiments. We also briefly point out challenges that confront the experimenter when interpreting time-resolved fluorescence responses.

  15. Combined enhanced fluorescence and label-free biomolecular detection with a photonic crystal surface.

    Science.gov (United States)

    Mathias, Patrick C; Ganesh, Nikhil; Chan, Leo L; Cunningham, Brian T

    2007-04-20

    A 2D photonic crystal surface with a different period in each lateral direction is demonstrated to detect biomolecules using two distinct sensing modalities. The sensing mechanisms both rely on the generation of a resonant reflection peak at one of two specific wavelengths, depending on the polarization of light that is incident on the photonic crystal. One polarization results in a resonant reflection peak in the visible spectrum to coincide with the excitation wavelength of a fluorophore, while the orthogonal polarization results in a resonant reflection peak at an infrared wavelength which is used for label-free detection of adsorbed biomolecules. The photonic crystal resonance for fluorescence excitation causes enhanced near fields at the structure surface, resulting in increased signal from fluorophores within 100 nm of the device surface. Label-free detection is performed by illuminating the photonic crystal with white light and monitoring shifts in the peak reflected wavelength of the infrared resonance with a high-resolution imaging detection instrument. Rigorous coupled-wave analysis was used to determine optimal dimensions for the photonic crystal structure, and devices were fabricated using a polymer-based nanoreplica molding approach. Fluorescence-based and label-free detection were demonstrated using arrays of spots of dye-conjugated streptavidin. Quantification of the fluorescent signal showed that the fluorescence output from protein spots on the photonic crystal was increased by up to a factor of 35, and deposited spots were also imaged in the label-free detection mode.

  16. Capillary electrophoresis of FITC labeled amino acids with laser-induced fluorescence detection

    Institute of Scientific and Technical Information of China (English)

    党福全; 陈义

    1999-01-01

    FITC labeled amino acids have been separated using a home-huilt capillary electrophoresis with a laserinduced fluorescence detection (CE-LIF) system. Seventeen peaks can now be generated from the twenty common amino acids. The key conditions lie in the optimization of pH, buffer electrolytes and buffer additives.

  17. Differentiation of cancerous and normal brain tissue using label free fluorescence and Stokes shift spectroscopy

    Science.gov (United States)

    Zhou, Yan; Wang, Leana; Liu, Cheng-hui; He, Yong; Yu, Xinguang; Cheng, Gangge; Wang, Peng; Shu, Cheng; Alfano, Robert R.

    2016-03-01

    In this report, optical biopsy was applied to diagnose human brain cancer in vitro for the identification of brain cancer from normal tissues by native fluorescence and Stokes shift spectra (SSS). 77 brain specimens including three types of human brain tissues (normal, glioma and brain metastasis of lung cancers) were studied. In order to observe spectral changes of fluorophores via fluorescence, the selected excitation wavelength of UV at 300 and 340 nm for emission spectra and a different Stokes Shift spectra with intervals Δλ = 40 nm were measured. The fluorescence spectra and SSS from multiple key native molecular markers, such as tryptophan, collagen, NADH, alanine, ceroid and lipofuscin were observed in normal and diseased brain tissues. Two diagnostic criteria were established based on the ratios of the peak intensities and peak position in both fluorescence and SSS spectra. It was observed that the ratio of the spectral peak intensity of tryptophan (340 nm) to NADH (440 nm) increased in glioma, meningioma (benign), malignant meninges tumor, and brain metastasis of lung cancer tissues in comparison with normal tissues. The ratio of the SS spectral peak (Δλ = 40 nm) intensities from 292 nm to 366 nm had risen similarly in all grades of tumors.

  18. An adaptive sampling algorithm for Doppler-shift fluorescence velocimetry in high-speed flows

    Science.gov (United States)

    Le Page, Laurent M.; O'Byrne, Sean

    2017-03-01

    We present an approach to improving the efficiency of obtaining samples over a given domain for the peak location of Gaussian line-shapes. The method uses parameter estimates obtained from previous measurements to determine subsequent sampling locations. The method may be applied to determine the location of a spectral peak, where the monetary or time cost is too high to allow a less efficient search method, such as sampling at uniformly distributed domain locations, to be used. We demonstrate the algorithm using linear least-squares fitting of log-scaled planar laser-induced fluorescence data combined with Monte-Carlo simulation of measurements, to accurately determine the Doppler-shifted fluorescence peak frequency for each pixel of a fluorescence image. A simulated comparison between this approach and a uniformly spaced sampling approach is carried out using fits both for a single pixel and for a collection of pixels representing the fluorescence images that would be obtained in a hypersonic flow facility. In all cases, the peak location of Doppler-shifted line-shapes were determined to a similar precision with fewer samples than could be achieved using the more typical uniformly distributed sampling approach.

  19. Fluorescence of silicon nanoparticles prepared by nanosecond pulsed laser

    Directory of Open Access Journals (Sweden)

    Chunyang Liu

    2014-03-01

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

  20. Silver nanoclusters emitting weak NIR fluorescence biomineralized by BSA

    Science.gov (United States)

    Li, Baoshun; Li, Jianjun; Zhao, Junwu

    2015-01-01

    Noble metal (e.g., gold and silver) nanomaterials possess unique physical and chemical properties. In present work, silver nanoclusters (also known as silver quantum clusters or silver quantum dots) were synthesized by bovine serum albumin (BSA) biomineralization. The synthesized silver nanoclusters were characterized by UV-VIS absorption spectroscopy, fluorescence spectroscopy, upconversion emission spectroscopy, TEM, HRTEM and FTIR spectroscopy. TEM results showed that the average size of the silver nanoclusters was 2.23 nm. Fluorescence results showed that these silver nanoclusters could emit weak near-infrared (NIR) fluorescence (the central emission wavelength being about 765 nm). And the central excitation wavelength was about 395 nm, in the UV spectral region. These silver nanoclusters showed an extraordinarily large gap (about 370 nm) between the central excitation wavelength and central emission wavelength. In addition, it was found that these silver nanoclusters possess upconversion emission property. Upconversion emission results showed that the upconversion emission spectrum of the silver nanoclusters agreed well with their normal fluorescence emission spectrum. The synthesized silver nanoclusters showed high stability in aqueous solution and it was considered that they might be confined in BSA molecules. It was found that silver nanoclusters might enhance and broaden the absorption of proteins, and the protein absorption peak showed an obvious red shift (being 7 nm) after the formation of silver nanoclusters.

  1. Multiplex fluorescent immunoassay device based on magnetic nanoparticles

    Science.gov (United States)

    Godjevargova, T. I.; Ivanov, Y. L.; Dinev, D. D.

    2017-02-01

    Immunofluorescent analyzer based compact disc for simultaneous detection of 3 antibiotics in the same milk sample is consisting of two parts: CD-based immunofluorescence kit and optoelectronic fluorometer. Kit consists of 2 parts: Lyophilized immobilized antibodies on supermagnetic nanoparticles in Eppendorf tubes and CD-based microfluidic disk, in which are formed five chamber systems for simultaneous detecting of 5 separate samples. Each system consists of 2 chambers connected by a special micro channel acting as a hydrophobic valve. In the first chamber lyophilised conjugates of 3 antibiotics with accordingly 3 different fluorescent dyes are placed. The second chamber is for detection of fluorescent signal. The optoelectronic fluorometer is comprising of: integrated thermostatic block; mechanical-detecting unit (fluorometer) and block with controlling and visualizing electronics.The disc gets into a second block of the analyzer, where centrifugation is performed and also reporting of the fluorescent signals. This unit comprises a rotor on which the disc is fixed, permanent electromagnet in the form of a ring inserted under the disc and module of 3 LED diodes with emission filters for the relevant wavelengths corresponding to the used fluorescent dyes and 1 integrated photodiode, in front of which is mounted filter with 3 spectral peaks.The signal from the photodiode is detected by the electronic unit which is sensitive "lock-in" amplifier, the engine rotor management, control of thermostatic device and management of periphery of the analyzer, consisting of display and communications with computer.

  2. Fluorescence of silicon nanoparticles prepared by nanosecond pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-15

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

  3. Effect of Phosphatidylcholine on the Steady State Fluorescence of Chlorophyll in Photosystem Ⅱ Particles

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Phosphatidylcholine (PC) accounts for less than 1% of the total lipids in plant photosystem II (PSII) particles.In this experiment, PSII particles were reconstituted with PC to construct PSII-PC vesicles.The effect of PC on the steady state fluorescence of chlorophyll (Chl) in PSII particles was studied.The results show that PC significantly affected the fluorescence intensity, but did not obviously affect the fluorescence emission band peak position.PC also did not obviously affect the absorbance at 436 nm or the amide I band peak position in FT-IR spectroscopy of PSII particles.The results suggest that PC may affect the light energy transfer from the antenna chlorophyll molecules to the reaction center chlorophyll molecule (P680).

  4. Standardization of I-125. Sum-Peak Coincidence Counting

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2011-07-01

    I-125 is a nuclide which presents difficulties for standardization. The sum-peak method is one of the procedures used to standardize this radionuclide. Initially NaI (Tl)detectors and then the semiconductor detectors with higher resolution have been used.This paper describes the different methods based on the sum-peak procedure and the different expressions used to calculate the activity are deduced. We describe a general procedure for obtaining all of the above equations and many more. We analyze the influence of uncertainties in the used parameters in the uncertainty of the activity. We give a complete example of the transmission of uncertainty and the effects of correlations in the uncertainty of the activity of the sample. High-resolution spectra show an unresolved doublet of 62.0 keV and 62.8 keV. The paper presents two approaches to solve this problem. One is based on the calculation of area ratio and the sum of peak areas obtained from atomic and nuclear data, in the other we modify the equations so that the sum of the peak areas doublet, rather than its components, is present. (Author) 19 refs.

  5. After Cotton Prices Hit a 10-Year Peak...

    Institute of Scientific and Technical Information of China (English)

    Wang Zhaofeng

    2010-01-01

    @@ "With the fifth-grade seed cotton being priced at 4.5 yuan per 500 grams and Xinjiang lint cotton at nearly RMB 20,000 per ton, cotton prices have rocketed to a 10-year peak," Gap Chaoshan, President of the Liaocheng Cotton Association, told the reporter on September 26.

  6. Extreme value statistics of weak lensing shear peak counts

    CERN Document Server

    Reischke, Robert; Bartelmann, Matthias

    2015-01-01

    The statistics of peaks in weak gravitational lensing maps is a promising technique to constrain cosmological parameters in present and future surveys. Here we investigate its power when using general extreme value statistics which is very sensitive to the exponential tail of the halo mass function. To this end, we use an analytic method to quantify the number of weak lensing peaks caused by galaxy clusters, large-scale structures and observational noise. Doing so, we further improve the method in the regime of high signal-to-noise ratios dominated by non-linear structures by accounting for the embedding of those counts into the surrounding shear caused by large scale structures. We derive the extreme value and order statistics for both over-densities (positive peaks) and under-densities (negative peaks) and provide an optimized criterion to split a wide field survey into sub-fields in order to sample the distribution of extreme values such that the expected objects causing the largest signals are mostly due ...

  7. T(peak)T(end) interval in long QT syndrome

    DEFF Research Database (Denmark)

    Kanters, Jørgen Kim; Haarmark, Christian; Vedel-Larsen, Esben;

    2008-01-01

    to the occurrence of syncope. METHODS: Electrocardiograms were taken in 95 patients with LQTS drawn from the Danish long QT registry (44 patients with KvLQT1, 43 with HERG, and 8 with SCN5A mutations) and manually evaluated for the QT, QT(peak), and RR interval. RESULTS AND CONCLUSION: (1) T(p)T(e) cannot be used...

  8. Effect of residual stress on peak cap stress in arteries.

    Science.gov (United States)

    Vandiver, Rebecca

    2014-10-01

    Vulnerable plaques are a subset of atherosclerotic plaques that are prone to rupture when high stresses occur in the cap. The roles of residual stress, plaque morphology, and cap stiffness on the cap stress are not completely understood. Here, arteries are modeled within the framework of nonlinear elasticity as incompressible cylindrical structures that are residually stressed through differential growth. These structures are assumed to have a nonlinear, anisotropic, hyperelastic response to stresses in the media and adventitia layers and an isotropic response in the intima and necrotic layers. The effect of differential growth on the peak stress is explored in a simple, concentric geometry and it is shown that axial differential growth decreases the peak stress in the inner layer. Furthermore, morphological risk factors are explored. The peak stress in residually stressed cylinders is not greatly affected by changing the thickness of the intima. The thickness of the necrotic layer is shown to be the most important morphological feature that affects the peak stress in a residually stressed vessel.

  9. Correlative Peak Interval Prediction and Analysis of Chaotic Sequences

    Directory of Open Access Journals (Sweden)

    Qun Ding

    2011-07-01

    Full Text Available The paper proposes a digital circuit design for the logistic-map module used in chaotic stream ciphers, analyzes the factors that may affect the output of the sequences, and develops a calculation method for estimating the output sequential correlative peak interval. With the respective tests using different initial values, the values of parameter u and the computational precisions, extensive experiments   have   been   carried   out.   A   formula   for calculating correlative peak interval is proposed. Moreover, the relationships among precision, parameter u and correlative peak interval is provided. To ensure the security of the plaintext which is encrypted by the output sequence of the logistic-map, a proper precision could be chosen according to the formula. It provides a theoretic basis for the actual application of the chaos cryptology. The basic theory and methods have a significant implication on the statistical analysis and practical applications of the digital chaotic sequences. A diagram that presents the relationship among precision, parameter u and correlative peak interval has been generated for analysis.

  10. Assessment of a peak flow whistle in nonasthmatic children.

    Science.gov (United States)

    Terblanche, E; Fourie, P R; Wessels, J A

    1999-06-01

    We tested the agreement of peak expiratory flow (PEF) measurements between an electronic spirometer and a peak flow whistle (Whistle Watch, HarMed, Capetown, South Africa). One hundred and three healthy children between ages 6-13 years and with no previous experience in lung function tests participated in the study. Sequential PEF-readings were obtained from the spirometer and the peak flow whistle; all children had an equal number of attempts using both devices. In the case of the spirometer, the highest PEF reading of three acceptable and reproducible efforts was noted as the best PEF (PEF(SPIRO)). Whistle Watch readings were taken as the highest value when the child could activate the whistle. Despite a strong correlation (r = 0.91; R2 = 83%) between the readings of the spirometer and Whistle Watch, there was a lack of agreement between the two devices. For any individual subject, the 95% probability interval ranged between +30.4 to -47 L.min(-1); 64% of the children obtained higher PEF-values on Whistle Watch, compared to the spirometer. These findings suggest that the whistle sound of the peak flow whistle was a significant incentive, which resulted in greater maximal expiratory efforts.

  11. Focal F0 peak shape and sentence mode in Swedish

    DEFF Research Database (Denmark)

    Ambrazaitis, Gilbert; Buanzur, Tuarik C.; Niebuhr, Oliver

    2015-01-01

    Shape characteristics of rising-falling accentual F0 peaks of Stockholm Swedish Accent I words in narrow focus are studied in a corpus of 287 read sentences. The corpus includes statements and three types of polar questions. Results reveal a clear effect of sentence mode on the shape of the accen...

  12. High Peak Power Gain Switched Flared Waveguide Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chow, W.W.; Indik, R.; Koch, S.W.; Mar, Alan, Vawter, G. Allen; Moloney, J.

    1999-08-05

    We gain-switch flared waveguide lasers to obtain 14.5 W peak powers and 0.5 nJ pulse energies with laser structures compatible with the generation of diffraction-limited beams. The results are in excellent agreement with a microscopic laser model.

  13. Mass spectral peak distortion due to Fourier transform signal processing.

    Science.gov (United States)

    Rockwood, Alan L; Erve, John C L

    2014-12-01

    Distortions of peaks can occur when one uses the standard method of signal processing of data from the Orbitrap and other FT-based methods of mass spectrometry. These distortions arise because the standard method of signal processing is not a linear process. If one adds two or more functions, such as time-dependent signals from a Fourier transform mass spectrometer and performs a linear operation on the sum, the result is the same as if the operation was performed on separate functions and the results added. If this relationship is not valid, the operation is non-linear and can produce unexpected and/or distorted results. Although the Fourier transform itself is a linear operator, the standard algorithm for processing spectra in Fourier transform-based methods include non-linear mathematical operators such that spectra processed by the standard algorithm may become distorted. The most serious consequence is that apparent abundances of the peaks in the spectrum may be incorrect. In light of these considerations, we performed theoretical modeling studies to illustrate several distortion effects that can be observed, including abundance distortions. In addition, we discuss experimental systems where these effects may manifest, including suggested systems for study that should demonstrate these peak distortions. Finally, we point to several examples in the literature where peak distortions may be rationalized by the phenomena presented here.

  14. Peak signal-to-noise ratio revisited: Is simple beautiful?

    DEFF Research Database (Denmark)

    Korhonen, Jari; You, Junyong

    2012-01-01

    Heavy criticism has been directed against using peak signal-to-noise ratio (PSNR) as a full reference quality metric for digitally processed images and video, since many studies have shown a weak correlation between subjective quality scores and the respective PSNR values. In this paper, we show...

  15. Peak broadening in paper chromatography and related techniques

    NARCIS (Netherlands)

    Ligny, C.L. de; Veen, N.G. van

    1972-01-01

    Peak dispersion (i.e. the separation efficiency) in thin-layer electrophoresis was investigated and compared for six different cellulose layers. The relative importance of longitudinal diffusion and of macroscopic inhomoeneities in the electric field and in the electroosmotic and sucking flow have

  16. Robust peak-shaving for a neighborhood with electric vehicles

    NARCIS (Netherlands)

    Gerards, Marco E.T.; Hurink, Johann L.

    2016-01-01

    Demand Side Management (DSM) is a popular approach for grid-aware peak-shaving. The most commonly used DSM methods either have no look ahead feature and risk deploying flexibility too early, or they plan ahead using predictions, which are in general not very reliable. To counter this, a DSM approach

  17. Probabilistic assignment of formulas to mass peaks in metabolomics experiments

    NARCIS (Netherlands)

    Rogers, Simon; Scheltema, Richard A.; Girolami, Mark; Breitling, Rainer

    2009-01-01

    Motivation: High-accuracy mass spectrometry is a popular technology for high-throughput measurements of cellular metabolites (metabolomics). One of the major challenges is the correct identification of the observed mass peaks, including the assignment of their empirical formula, based on the

  18. Analysis of multibeam-hydrosweep echo peaks for seabed characterisation

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Schenke, H.W.; Kodagali, V.N.; Hagen, R.

    , in general, Gaussian in nature except in the case of the Kainan Maru seamount summit (area D). The outer beams of the Enderby abyssal plain (area C) echo-peak PDF statistics reveal the highest possible large-scale feature dominance. Interestingly, Extremal...

  19. Determining cosmic microwave background structure from its peak distribution

    CERN Document Server

    Kashlinsky, A; Atrio-Barandela, F

    2001-01-01

    We present a new method for time-efficient and accurate extraction of the power spectrum from future cosmic microwave background (CMB) maps based on properties of peaks and troughs of the Gaussian CMB sky. We construct a statistic describing their angular clustering - analogously to galaxies, the 2-point angular correlation function, $\\xi_\

  20. Peak Stir Zone Temperatures during Friction Stir Processing

    Science.gov (United States)

    Swaminathan, Srinivasan; Oh-Ishi, Keiichiro; Zhilyaev, Alexander P.; Fuller, Christian B.; London, Blair; Mahoney, Murray W.; McNelley, Terry R.

    2010-03-01

    The stir zone (SZ) temperature cycle was measured during the friction stir processing (FSP) of NiAl bronze plates. The FSP was conducted using a tool design with a smooth concave shoulder and a 12.7-mm step-spiral pin. Temperature sensing was accomplished using sheathed thermocouples embedded in the tool path within the plates, while simultaneous optical pyrometry measurements of surface temperatures were also obtained. Peak SZ temperatures were 990 °C to 1015 °C (0.90 to 0.97 T Melt) and were not affected by preheating to 400 °C, although the dwell time above 900 °C was increased by the preheating. Thermocouple data suggested little variation in peak temperature across the SZ, although thermocouples initially located on the advancing sides and at the centerlines of the tool traverses were displaced to the retreating sides, precluding direct assessment of the temperature variation across the SZ. Microstructure-based estimates of local peak SZ temperatures have been made on these and on other similarly processed materials. Altogether, the peak-temperature determinations from these different measurement techniques are in close agreement.

  1. Peak HIV prevalence : a useful outcome variable for ecological studies

    NARCIS (Netherlands)

    Kenyon, Chris; Colebunders, Robert; Voeten, Helene; Lurie, Mark

    2013-01-01

    A key question for ecological studies with HIV as the outcome variable is what measure of HIV prevalence to use. In this study we compared the strengths and weaknesses of a variety of measures of HIV prevalence, focusing on peak HIV prevalence and HIV prevalence measured at the same time as the expo

  2. Characteristics of peaks of inhalation exposure to organic solvents

    NARCIS (Netherlands)

    Preller, L.; Burstyn, I.; Pater, N. de; Kromhout, H.

    2004-01-01

    Objectives: To determine which exposure metrics are sufficient to characterize 'peak' inhalation exposure to organic solvents (OS) during spraying operations. Methods: Personal exposure measurements (n = 27; duration 5-159 min) were collected during application of paints, primers, resins and glues i

  3. Identification of photoelectron energy peaks in Saturn's inner neutral torus

    Science.gov (United States)

    Schippers, P.; André, N.; Johnson, R. E.; Blanc, M.; Dandouras, I.; Coates, A. J.; Krimigis, S. M.; Young, D. T.

    2009-12-01

    We present observations from the Cassini Plasma Electron Spectrometer (CAPS/ELS) of characteristic peaks in the electron energy spectrum that are identified in the innermost regions of the Saturnian magnetosphere during low-latitude orbits of the Cassini spacecraft around Saturn. We show how a narrow electron energy peak at about 20 eV and a possible peak at about 42 eV can be extracted from the background in CAPS observations after the contamination from high-energy particles has been removed from the measurements. We estimate the density of the newly discovered electron population to be a small fraction (10%) of the electron density measured in the CAPS/ELS energy range, and a much smaller fraction (about 1%) of the total electron density measured by Radio and Plasma Wave Science since our measurements are affected by spacecraft negative potential. We suggest that this population corresponds to photoelectrons generated by the solar EUV photoionization of the extended cloud of neutral gas observed in these regions. We use pitch angle information to assess the near-equatorial source of these photoelectrons and a simple model of chemistry in order to further support our interpretation. Therefore, photoionization seems to be an additional process for plasma production in the innermost Saturnian magnetosphere. Finally, we mention that the comparison of the modeled and the observed photoelectron peak energies could be used to estimate the spacecraft potential in this region which is measured independently by the Langmuir Probe.

  4. Probabilistic assignment of formulas to mass peaks in metabolomics experiments

    NARCIS (Netherlands)

    Rogers, Simon; Scheltema, Richard A.; Girolami, Mark; Breitling, Rainer

    2009-01-01

    Motivation: High-accuracy mass spectrometry is a popular technology for high-throughput measurements of cellular metabolites (metabolomics). One of the major challenges is the correct identification of the observed mass peaks, including the assignment of their empirical formula, based on the measure

  5. Robust peak-shaving for a neighborhood with electric vehicles

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Hurink, Johann L.

    2016-01-01

    Demand Side Management (DSM) is a popular approach for grid-aware peak-shaving. The most commonly used DSM methods either have no look ahead feature and risk deploying flexibility too early, or they plan ahead using predictions, which are in general not very reliable. To counter this, a DSM approach

  6. Peak Reduction and Clipping Mitigation by Compressive Sensing

    CERN Document Server

    Al-Safadi, Ebrahim B

    2011-01-01

    This work establishes the design, analysis, and fine-tuning of a Peak-to-Average-Power-Ratio (PAPR) reducing system, based on compressed sensing at the receiver of a peak-reducing sparse clipper applied to an OFDM signal at the transmitter. By exploiting the sparsity of the OFDM signal in the time domain relative to a pre-defined clipping threshold, the method depends on partially observing the frequency content of extremely simple sparse clippers to recover the locations, magnitudes, and phases of the clipped coefficients of the peak-reduced signal. We claim that in the absence of optimization algorithms at the transmitter that confine the frequency support of clippers to a predefined set of reserved-tones, no other tone-reservation method can reliably recover the original OFDM signal with such low complexity. Afterwards we focus on designing different clipping signals that can embed a priori information regarding the support and phase of the peak-reducing signal to the receiver, followed by modified compres...

  7. [Application of the racial algorithm in energy dispersive X-ray fluorescence overlapped spectrum analysis].

    Science.gov (United States)

    Zeng, Guo-Qiang; Luo, Yao-Yao; Ge, Liang-Quan; Zhang, Qing-Xian; Gu, Yi; Cheng, Feng

    2014-02-01

    In the energy dispersive X-ray fluorescence spectrum analysis, scintillation detector such as NaI (Tl) detector usually has a low energy resolution at around 8%. The low energy resolution causes problems in spectral data analysis especially in the high background and low counts condition, it is very limited to strip the overlapped spectrum, and the more overlapping the peaks are, the more difficult to peel the peaks, and the qualitative and quantitative analysis can't be carried out because we can't recognize the peak address and peak area. Based on genetic algorithm and immune algorithm, we build a new racial algorithm which uses the Euclidean distance as the judgment of evolution, the maximum relative error as the iterative criterion to be put into overlapped spectrum analysis, then we use the Gaussian function to simulate different overlapping degrees of the spectrum, and the racial algorithm is used in overlapped peak separation and full spectrum simulation, the peak address deviation is in +/- 3 channels, the peak area deviation is no more than 5%, and it is proven that this method has a good effect in energy dispersive X-ray fluorescence overlapped spectrum analysis.

  8. Fluorescent Biotin Analogues for Microstructure Patterning and Selective Protein Immobilization.

    Science.gov (United States)

    Krishna, K Vijaya; Ghosh, Subhadip; Sharma, Bikramjit; Singh, Leeju; Mukherjee, Saptarshi; Verma, Sandeep

    2015-11-24

    Benzyl substitution on ureido nitrogens of biotin led to manifestation of aggregation-induced emission, which was studied by steady-state fluorescence, microscopy, and TD-DFT, providing a rationale into the observed photophysical behavior. Besides exhibiting solvatochromism, the biotin derivatives revealed emission peaks centered at ∼430 and 545 nm, which has been attributed to the π-π stacking interactions. Our TD-DFT results also correlate the spectroscopic data and quantify the nature of transitions involved. The isothermal titration calorimetry data substantiates that the binding of the biotin derivatives with avidin are pretty strong. These derivatives on lithographic patterning present a platform for site specific strept(avidin) immobilization, thus opening avenues for potential applications exploiting these interactions. The fluorescent biotin derivatives can thus find applications in cellular biology and imaging.

  9. Effect of Ag Particles on the Fluorescence Properties of Eu Ions in Lead Borate Glasses

    Science.gov (United States)

    Giri, Prakash; Dc, Mahendra; Mallur, Saisudha; Babu, P. K.

    2011-11-01

    We have investigated the effect of Ag particles on the fluorescence of trivalent Eu ions in lead borate glasses. Lead borate glasses were prepared with varying Ag content (0 to 3 mol%) and sizes of Ag particles were controlled by varying the duration of annealing near the glass transition temperature. Fluorescence spectra of all these samples were obtained at two different excitation wavelengths (395 nm and 464 nm). Glass samples with Ag particles show an increase in the intensities for the major peaks in the Eu fluorescence spectra, appearing near 589 nm and 613 nm. Detailed analysis show that the enhancement effects clearly depend on the duration of annealing and the concentration of Ag. Fluorescence intensity enhancement is readily observed at relatively shorter annealing time (5 h) for samples with higher Ag concentration whereas a much longer annealing time (25 h) is required to observe any significant enhancement in fluorescence intensity for lower concentration of Ag. For higher concentrations of Ag, a broad feature is seen around 450 nm due to the emission from Ag particles and the effect of Ag is more pronounced for the fluorescence peak at 589 nm.

  10. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-06-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  11. Superoxide dismutase levels and peak expiratory flow in asthmatic children

    Directory of Open Access Journals (Sweden)

    Arie Kurniasih

    2016-11-01

    Full Text Available involvevariety of cells such as inflammatory mediators, reactive oxygenspecies (ROS, and cytokines. The inflammatory process would beexacerbated in the presence of oxidative stress. Superoxide dismutase(SOD is the first important enzyme to protect the respiratory tractagainst oxidative stress. The decreased of SOD has a correlation withincreased of airway obstruction and bronchospasm.Objective To assess for a correlation between superoxide dismutase(SOD levels and peak expiratory flow, as well as to determinethe impact of SOD levels for predicting asthma attacks.Methods We conducted a prospective cohort study at Dr. SardjitoHospital, Yogyakarta, between February and April 2011 involvingasthmatic children aged 5-18 years. Subjects’ serum SOD levelsand peak expiratory flow were measured at the same time point.We then performed a prospective study following up on the samesubjects to find out if they had a recurrent asthma attack withinone month of the tests. We also reassessed their peak expiratoryflow one month after blood specimens were obtained.Results Thirty-nine patients were enrolled in this study. Therewas no significant correlation between SOD level and peakexpiratory flow [r=0.289; 95%CI -0.025 to 0.47; P=0.074].However, older age was significantly associated with higher peakexpiratory flow (=0.5; 95%CI 3.10 to 11.57; P=0.01. Lowerlevels of SOD increased the risk of asthma attacks in a monthfollowing the initial measurements (RR=5.5; 95%CI 1.6 to 18.9;P=0.009.Conclusion Superoxide dismutase (SOD level is not significantlyassociated with peak expiratory flow. However, we find arelationship between older age and higher peak expiratory flowand a relationship between lower SOD levels and risk of asthmaattacks within one month following the tests. [

  12. Aerobic power and peak power of elite America's Cup sailors.

    Science.gov (United States)

    Neville, Vernon; Pain, Matthew T G; Folland, Jonathan P

    2009-05-01

    Big-boat yacht racing is one of the only able bodied sporting activities where standing arm-cranking ('grinding') is the primary physical activity. However, the physiological capabilities of elite sailors for standing arm-cranking have been largely unreported. The purpose of the study was to assess aerobic parameters, VO(2peak) and onset of blood lactate (OBLA), and anaerobic performance, torque-crank velocity and power-crank velocity relationships and therefore peak power (P (max)) and optimum crank-velocity (omega(opt)), of America's Cup sailors during standing arm-cranking. Thirty-three elite professional sailors performed a step test to exhaustion, and a subset of ten grinders performed maximal 7 s isokinetic sprints at different crank velocities, using a standing arm-crank ergometer. VO(2peak) was 4.7 +/- 0.5 L/min (range 3.6-5.5 L/min) at a power output of 332 +/- 44 W (range 235-425 W). OBLA occurred at a power output of 202 +/- 31 W (61% of W(max)) and VO(2) of 3.3 +/- 0.4 L/min (71% of VO(2peak)). The torque-crank velocity relationship was linear for all participants (r = 0.9 +/- 0.1). P (max) was 1,420 +/- 37 W (range 1,192-1,617 W), and omega(opt) was 125 +/- 6 rpm. These data are among the highest upper-body anaerobic and aerobic power values reported. The unique nature of these athletes, with their high fat-free mass and specific selection and training for standing arm cranking, likely accounts for the high values. The influence of crank velocity on peak power implies that power production during on-board 'grinding' may be optimised through the use of appropriate gear-ratios and the development of efficient gear change mechanisms.

  13. Peak-locking reduction for particle image velocimetry

    Science.gov (United States)

    Michaelis, Dirk; Neal, Douglas R.; Wieneke, Bernhard

    2016-10-01

    A parametric study of the factors contributing to peak-locking, a known bias error source in particle image velocimetry (PIV), is conducted using synthetic data that are processed with a state-of-the-art PIV algorithm. The investigated parameters include: particle image diameter, image interpolation techniques, the effect of asymmetric versus symmetric window deformation, number of passes and the interrogation window size. Some of these parameters are found to have a profound effect on the magnitude of the peak-locking error. The effects for specific PIV cameras are also studied experimentally using a precision turntable to generate a known rotating velocity field. Image time series recorded using this experiment show a linear range of pixel and sub-pixel shifts ranging from 0 to  ±4 pixels. Deviations in the constant vorticity field (ω z ) reveal how peak-locking can be affected systematically both by varying parameters of the detection system such as the focal distance and f-number, and also by varying the settings of the PIV analysis. A new a priori technique for reducing the bias errors associated with peak-locking in PIV is introduced using an optical diffuser to avoid undersampled particle images during the recording of the raw images. This technique is evaluated against other a priori approaches using experimental data and is shown to perform favorably. Finally, a new a posteriori anti peak-locking filter (APLF) is developed and investigated, which shows promising results for both synthetic data and real measurements for very small particle image sizes.

  14. Combining fluorescence and bioluminescence microscopy.

    Science.gov (United States)

    Goda, Kazuhito; Hatta-Ohashi, Yoko; Akiyoshi, Ryutaro; Sugiyama, Takashi; Sakai, Ikuko; Takahashi, Takeo; Suzuki, Hirobumi

    2015-08-01

    Bioluminescence microscopy has revealed that gene expression in individual cells can respond differently to the same stimulus. To understand this phenomenon, it is important to sequentially observe the series of events from cellular signal transduction to gene expression regulated by specific transcription factors derived from signaling cascades in individual cells. However, these processes have been separately analyzed with fluorescence and bioluminescence microscopy. Furthermore, in culture medium, the background fluorescence of luciferin-a substrate of luciferase in promoter assays of gene expression in cultured cells-confounds the simultaneous observation of fluorescence and bioluminescence. Therefore, we optimized conditions for optical filter sets based on spectral properties and the luciferin concentration based on cell permeability for fluorescence observation combined with bioluminescence microscopy. An excitation and emission filter set (492-506 nm and 524-578 nm) was suitable for green fluorescent protein and yellow fluorescent protein imaging of cells, and >100 μM luciferin was acceptable in culture medium based on kinetic constants and the estimated intracellular concentration. Using these parameters, we present an example of sequential fluorescence and bioluminescence microscopic observation of signal transduction (translocation of protein kinase C alpha from the cytoplasm to the plasma membrane) coupled with activation of gene expression by nuclear factor of kappa light polypeptide B in individual cells and show that the gene expression response is not completely concordant with upstream signaling following stimulation with phorbol-12-myristate-13-acetate. Our technique is a powerful imaging tool for analysis of heterogeneous gene expression together with upstream signaling in live single cells.

  15. Dual channel fluorescence engineering on the nano-patterened metamaterial (Conference Presentation)

    Science.gov (United States)

    Wu, Huijun; Tseng, Ming Lun; Tsai, Wei Yi; Chen, Ting-Yu; Chien, Yihsin; Chang, Yun-Chorng; Tsai, Din Ping

    2016-09-01

    Upconversion fluorescence from Lanthanide-doped nanocrystals has attracted widespread interests because of its greatly potential applications in various fields, such as photonic crystal lasers, material science, biological therapy, and so on. However, the relatively low quantum yield (typically chemical methods, plasmonic structures have been adopted as another strategy to improve the radiation efficiency and control the relaxation process of the upcovnersion nanocrystals. We designed the anti-symmetric split ring resonators with various periods and the fishnet structures. The surface plasmon resonance peaks of the structure shift as the periods varies. For example, in a multi-layered plamsonic metasurface with the period of 250nm, both the electric and magnetic modes could be generated simultaneously when excited by the incident light with proper polarization. This plasmonic structure provides two different channels for the enhancement of upconversion fluorescence. The resonance peak of 650nm is magnetic resonance mode, while the peak of 980nm is electric resonance mode. The resonance peak of 980nm coincides with the absorption band of the Lanthanide-dopoed nanocrystal, and the peak of 650nm matches with its emission band. We found that the upconversion fluorescence intensity could be enhanced more than 10 times when the electric resonance frequency of the metasurface matches with the absorption band of the upconversion nanocrystals, while the magnetic mode overlaps with its emission band. This is due to the local density of optical states was significantly enhanced by the plasmonic metasurface. The detailed results and mechanism will be discussed.

  16. Delayed fluorescence spectroscopy and mechanism of the 730 nm component of chloroplast

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-long; XING Da; FAN Duo-wang; QIAN Long; LU Mai

    2006-01-01

    Charge recombination in reaction center (RC) of photosystem Ⅱ(PS Ⅱ)is regarded as the location of 685 nm delayed fluorescence (DF). The mechanism of 730 nm component appearing in the DF spectrum for chloroplast was studied by various spectral analysis methods. Experimental results of the DF spectrum at different chloroplast concentration show that the intensity of peaks at 685nm and 730 nm ascends with the chloroplast concentration increasing when the concentration is relatively low. When the concentration increases to the level of 7.8 μg/ml, a maximum intensity of the peak at 685 nm appears but the intensity of 730 nm peak still increases. The peak at 730 nm finally reaches a maximum intensity at the chloroplast concentration of 31.2 μg/ml while the intensity of the 685 nm peak has apparently fallen down. The results of absorption spectrum show that the ratios of A685 to A730 keep almost constant with the increasing of chloroplast concentration. Furthermore, the excitation spectrum for 730 nm fluorescence shows that the 685nm light has high excitation efficiency.These results indicate that the 730nm component of DF spectrum is the fluorescence of chlorophyll in PS Ⅰ RC excited by 685 nm DF. Meanwhile, this can be further verified by the invariability of DF spectrum at different delay time (1 second~9 seconds).

  17. Fluorescence-based enhanced reality (FLER) for real-time estimation of bowel perfusion in minimally invasive surgery

    Science.gov (United States)

    Diana, Michele

    2016-03-01

    Pre-anastomotic bowel perfusion is a key factor for a successful healing process. Clinical judgment has limited accuracy to evaluate intestinal microperfusion. Fluorescence videography is a promising tool for image-guided intraoperative assessment of the bowel perfusion at the future anastomotic site in the setting of minimally invasive procedures. The standard configuration for fluorescence videography includes a Near-Infrared endoscope able to detect the signal emitted by a fluorescent dye, more frequently Indocyanine Green (ICG), which is administered by intravenous injection. Fluorescence intensity is proportional to the amount of fluorescent dye diffusing in the tissue and consequently is a surrogate marker of tissue perfusion. However, fluorescence intensity alone remains a subjective approach and an integrated computer-based analysis of the over-time evolution of the fluorescence signal is required to obtain quantitative data. We have developed a solution integrating computer-based analysis for intra-operative evaluation of the optimal resection site, based on the bowel perfusion as determined by the dynamic fluorescence intensity. The software can generate a "virtual perfusion cartography", based on the "fluorescence time-to-peak". The virtual perfusion cartography can be overlapped onto real-time laparoscopic images to obtain the Enhanced Reality effect. We have defined this approach FLuorescence-based Enhanced Reality (FLER). This manuscript describes the stepwise development of the FLER concept.

  18. Revisiting the Correlations of Peak Luminosity with Spectral Lag and Peak Energy of the Observed Gamma-ray Bursts

    Science.gov (United States)

    Jo, Yun-A.; Chang, Heon-Young

    2016-12-01

    An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs). We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at 0.1 and 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV) yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT) has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV). We also found that peak luminosity is positively correlated with peak energy.

  19. Plasmonics Enhanced Smartphone Fluorescence Microscopy

    KAUST Repository

    Wei, Qingshan

    2017-05-12

    Smartphone fluorescence microscopy has various applications in point-of-care (POC) testing and diagnostics, ranging from e.g., quantification of immunoassays, detection of microorganisms, to sensing of viruses. An important need in smartphone-based microscopy and sensing techniques is to improve the detection sensitivity to enable quantification of extremely low concentrations of target molecules. Here, we demonstrate a general strategy to enhance the detection sensitivity of a smartphone-based fluorescence microscope by using surface-enhanced fluorescence (SEF) created by a thin metal-film. In this plasmonic design, the samples are placed on a silver-coated glass slide with a thin spacer, and excited by a laser-diode from the backside through a glass hemisphere, generating surface plasmon polaritons. We optimized this mobile SEF system by tuning the metal-film thickness, spacer distance, excitation angle and polarization, and achieved ~10-fold enhancement in fluorescence intensity compared to a bare glass substrate, which enabled us to image single fluorescent particles as small as 50 nm in diameter and single quantum-dots. Furthermore, we quantified the detection limit of this platform by using DNA origami-based brightness standards, demonstrating that ~80 fluorophores per diffraction-limited spot can be readily detected by our mobile microscope, which opens up new opportunities for POC diagnostics and sensing applications in resource-limited-settings.

  20. Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W., E-mail: walter.assmann@lmu.de; Reinhardt, S.; Lehrack, S.; Edlich, A.; Thirolf, P. G.; Parodi, K. [Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748 (Germany); Kellnberger, S.; Omar, M.; Ntziachristos, V. [Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764 (Germany); Moser, M.; Dollinger, G. [Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577 (Germany)

    2015-02-15

    Purpose: Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. Methods: A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. Results: In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 10{sup 12} eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. Conclusions: The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound

  1. Dependence of Purcell effect on fluorescence wavelength in dye molecules on metal-dielectric multilayer hyperbolic metamaterials

    Science.gov (United States)

    Tsurumachi, Noriaki; Izawa, Hayato; Tomioka, Ryo; Sakata, Tomohiro; Suzuki, Makoto; Tanaka, Yasuhiro; Shimokawa, Fusao; Nakanishi, Shunsuke

    2016-02-01

    Recently, the enhancement of spontaneous emission, i.e., broadband Purcell effect, has been achieved using hyperbolic metamaterials. Hyperbolic metamaterials, which can be realized using a metal-dielectric multilayer structure, have an extremely large optical anisotropy of permittivity in both the parallel and perpendicular directions to the propagation of light, especially when the signs of permittivities in both directions differ. In this study, we investigated the conditions for realizing the broadband Purcell effect using dye molecules with different fluorescence wavelengths. Our fabricated metal-dielectric multilayer structure exhibited hyperbolic dispersion at wavelengths beyond 500 nm. In the case of coumarin 500 whose fluorescence peak is located at 500 nm, no broadband Purcell effect was observed. However, in the case of pyridine 1 whose fluorescence peak is located at 650 nm, we observed the successfull fluorescence lifetime shortening, i.e., the broadband Purcell effect.

  2. Magnetic resonance tracking of fluorescent nanodiamond fabrication

    Science.gov (United States)

    Shames, A. I.; Osipov, V. Yu; Boudou, J. P.; Panich, A. M.; von Bardeleben, H. J.; Treussart, F.; Vul', A. Ya

    2015-04-01

    Magnetic resonance techniques (electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR)) are used for tracking the multi-stage process of the fabrication of fluorescent nanodiamonds (NDs) produced by high-energy electron irradiation, annealing, and subsequent nano-milling. Pristine commercial high pressure and high temperature microdiamonds (MDs) with mean size 150 μm contain ~5  ×  1018 spins/g of singlet (S = 1/2) substitutional nitrogen defects P1, as well as sp3 C-C dangling bonds in the crystalline lattice. The half-field X-band EPR clearly shows (by the appearance of the intense ‘forbidden’ g = 4.26 line) that high-energy electron irradiation and annealing of MDs induce a large amount (~5  ×  1017 spins/g) of triplet (S = 1) magnetic centers, which are identified as negatively charged nitrogen vacancy defects (NV-). This is supported by EPR observations of the ‘allowed’ transitions between Zeeman sublevels of the triplet state. After progressive milling of the fluorescent MDs down to an ultrasubmicron scale (≤100 nm), the relative abundance of EPR active NV- defects in the resulting fluorescent NDs (FND) substantially decreases and, vice versa, the content of C-inherited singlet defects correlatively increases. In the fraction of the finest FNDs (mean particle size dried supernatant of ultracentrifuged aqueous dispersion of FNDs, the NV- content is found to be reduced by one order of magnitude whereas the singlet defects content increases up to ~2  ×  1019 spins/g. In addition, another triplet-type defect, which is characterized by the g = 4.00 ‘forbidden’ line, appears. On reduction of the particle size below the 20 nm limit, the ‘allowed’ EPR lines become practically unobservable, whereas the ‘forbidden’ lines remain as a reliable fingerprint of the presence of NV- centers in small ND systems. The same size reduction causes the disappearance of the characteristic hyperfine satellites in the

  3. Resonance fluorescence from an asymmetric quantum dot dressed by a bichromatic electromagnetic field

    Science.gov (United States)

    Kryuchkyan, G. Yu.; Shahnazaryan, V.; Kibis, O. V.; Shelykh, I. A.

    2017-01-01

    We present the theory of resonance fluorescence from an asymmetric quantum dot driven by a two-component electromagnetic field with two different frequencies, polarizations, and amplitudes (bichromatic field) in the regime of strong light-matter coupling. It follows from the elaborated theory that the broken inversion symmetry of the driven quantum system and the bichromatic structure of the driving field result in unexpected features of the resonance fluorescence, including the infinite set of Mollow triplets, the quench of fluorescence peaks induced by the dressing field, and the oscillating behavior of the fluorescence intensity as a function of the dressing field amplitude. These quantum phenomena are of general physical nature and, therefore, can take place in various double-driven quantum systems with broken inversion symmetry.

  4. Identification of tartrazine and sunset yellow by fluorescence spectroscopy combined with radial basis function neural network

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Guoqing Chen; Tuo Zhu; Shumei Gao; Bailin Wei; Linna Bi

    2009-01-01

    @@ The fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed.The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480-750 and 500-750 nm induced by ultraviolet light between 310-400 nm.The fluorescence spectra of sunset yellow overlap heavily with those of tartrazine, so it is diffic ult to distinguish them.Based on the principle of radial basis function neural network, a neural network is obtained from the training of the 14 groups of experimental data.The results show that the species of sunset yellow and tartrazine could be recognized accurately.This method has potential applications in other synthetic food dyes detection and food safety inspection.

  5. Novel aspects of fluorescence lifetime for molecules positioned close to metal surfaces

    Science.gov (United States)

    Aussenegg, F. R.; Leitner, A.; Lippitsch, M. E.; Reinisch, H.; Riegler, M.

    1987-10-01

    On metal surfaces with submicroscopic corrugations, surface-enhanced optical processes can be observed. Results obtained by picosecond time-resolved fluorescence spectroscopy for dye molecules in the proximity (0-50 nm) of silver islands films are reported. It is demonstrated how the rather complex dependence of the integral fluorescence intensity on the distance dye-islands, can be resolved in the contributions of different mechanisms by analysing the fluorescence decay curves at various distances. It turns out, that the enhancement of absorption influences only the peak fluorescence intensity without changing the decay time, while the enhancement of emission and dissipative losses reduces the decay time. Thus time-resolved spectroscopy opens the possibility to test theoretical concepts on surface enhancement and provides basic data for tailoring molecule-metal structures with well-defined surface-enhancement properties.

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

    Science.gov (United States)

    Bilski, P.; Marczewska, B.

    2017-02-01

    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 F2 and F3+ 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.

  7. Fluorescence characteristic changes of dissolved organic matter during municipal solid waste composting

    Institute of Scientific and Technical Information of China (English)

    WEI Zi-min; XI Bei-dou; WANG Shi-ping; XU Jing-gang; ZHOU Yu-yan; LIU Hong-liang

    2005-01-01

    Dissolved organic matter(DOM) of municipal solid waste(MSW) consists of minerals, water, ash and humic substances, and is known to enhance plant growth. In this study, inoculating microbes (Z J, MS) were used in municipal solid wastes composting, and composting implemented a industrialized technology. During composting, dissolved organic matter was extracted from the compost and purified. The spectral characteristics of dissolved organic matter was determined by fluorescence emission, excitation, and synchronous spectroscopy. Fluorescence emission, excitation, and synchronous spectra characterized by different relative fluorescent intensities and peaks over time. Fluorescence spectra were similar to that of fulvic acid in sewage sludge, indicating the presence of dissolved organic matter with aromatic structures and a high degree of molecular polymerization. Compared with the controls with no microbial inoculation,the microbe-inoculated treatments exhibited the increase of aromatic polycondensation, in the following order: MS + ZJ > ZJ > MS >CK.

  8. [Study of reference material for excitation spectrum wavelength calibration of fluorescence spectrophotometer].

    Science.gov (United States)

    Chen, Xiao-bo; Kang, Dong-guo; Zhao, Cheng-yi; Li, Song; Wu, Zheng-long; Ma, Hui; Liu, Zhong-min; Zheng, Zhe

    2005-07-01

    A reference material used for wavelength calibration of fluorescence spectrophotometer was found. The holmium doped oxide reference material GBW(E) 130112 is a kind of standard reference material for absorption spectrophotometer. It can emit 547.7 nm fluorescence when excited by xenon lamp light. The excitation spectrum of 547.7 nm fluorescence was measured. It was found that the measured peaks of excitation spectrum are positioned at 333.56, 360.43 and 418.39 nm, respectively, which are coincident with the true values 333.8, 360.9 and 418.5 nm of reference material certification. It was illustrated that the holmium doped oxide reference material GBW(E)130112 could be used as reference material for the excitation wavelength calibration of the fluorescence spectrophotometer. Its property could be enhanced very much if high luminescent efficiency material is selected as rare earth ion doped matrix, and the purity is enhanced to reduce the cross relaxation.

  9. Evaluation of peaking factors uncertainty for CASMO-3

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Suk; Song, Jae Seung; Kim, Yong Rae; Ji, Seong Kyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-02-01

    This document evaluates the pin-to-box factor uncertainty based on using the CASMO-3 with 40-group J-library. Five CE criticals performed by Westinghouse, two by B and W and four RPI criticals were analyzed, using cross sections by CASMO-3. DOT was used for the core calculation. THis is one hof series of efforts to verify ADONIS procedure which is a new core design package under development by KAERI. The expected outcome of this analysis is CASMO-3 pin peak uncertainty applicable to CE type fuel assembly design. The evaluated uncertainty of peaking factors for CASMO-3 was 1.863%. 21 tabs., 23 figs., 12 refs. (Author) .new.

  10. Households’ hourly electricity consumption and peak demand in Denmark

    DEFF Research Database (Denmark)

    Møller Andersen, Frits; Baldini, Mattia; Hansen, Lars Gårn

    2017-01-01

    to a considerable introduction of electric vehicles and individual heat pumps, household consumption is expected to increase considerably, especially peak hour consumption is expected to increase. Next the paper presents results from a new experiment where household customers are given economic and/or environmental......The electrification of residential energy demand for heating and transportation is expected to increase peak load and require additional generation and transmission capacities. Electrification also provides an opportunity to increase demand response. With a focus on household electricity...... incentives to shift consumption to or away from specified hours. The experiment focuses on the present classic consumption and shows that household customers do react to incentives, but today the flexibility of the classic consumption is limited. Considering electric vehicles and individual heat pumps...

  11. Peak Clipping in Power Lines using Distributed Generation

    Directory of Open Access Journals (Sweden)

    S. Sambath

    2015-05-01

    Full Text Available This real time study is intent to analyze the impact and role of Distributed Generation (DG in Tamil Nadu, India to examine what the benefits of decentralized generation would be for peak clipping. Using load flow analysis to simulation over a quantify the loss reduction and system improvement by having decentralized generation available line conditions for actual rural feeders in Tamil Nadu, India. In order to realize the energy efficiency potential and upscale the implementation of DSM program by utility, load research should be the starting point. One of the key objectives of load research is to understand and analyze the utility’s system load profile and Peak clipping. This helps utilities to better plan their system in Demand side Management.

  12. Systems and Methods for Peak-Seeking Control

    Science.gov (United States)

    Ryan, John J (Inventor); Speyer, Jason L (Inventor)

    2013-01-01

    A computerized system and method for peak-seeking-control that uses a unique Kalman filter design to optimize a control loop, in real time, to either maximize or minimize a performance function of a physical object ("plant"). The system and method achieves more accurate and efficient peak-seeking-control by using a time-varying Kalman filter to estimate both the performance function gradient (slope) and Hessian (curvature) based on direct position measurements of the plant, and does not rely upon modeling the plant response to persistent excitation. The system and method can be naturally applied in various applications in which plant performance functions have multiple independent parameters, and it does not depend upon frequency separation to distinguish between system dimensions.

  13. Peak athletic performance and ageing: evidence from baseball.

    Science.gov (United States)

    Bradbury, John Charles

    2009-04-01

    Baseball players exhibit a pattern of improvement and decline in performance; however, differing lengths of careers and changes in rules and characteristics of the game complicate assessments of age-related effects on performance. This study attempts to isolate the impact of age on several player skills while controlling for relevant outside factors using longitudinal data from 86 seasons of Major League Baseball. The results indicate that players age in different skills in accord with studies of ageing in other athletic contests. For overall performance, multiple-regression estimates indicate that hitters and pitchers peak around the age of 29 - later than previous estimates. Athletic skills such as hitting and running peak earlier than skills that rely heavily on experience and knowledge, such as issuing and drawing walks.

  14. The SECIS instrument on the Lomnicky Peak Observatory

    CERN Document Server

    Ambroz, J; Rudawy, P; Rybak, J; Phillips, K J H

    2010-01-01

    Heating mechanisms of the solar corona will be investigated at the high-altitude solar observatory Lomnicky Peak of the Astronomical Institute of SAS (Slovakia) using its mid-size Lyot coronagraph and post-focal instrument SECIS provided by Astronomical Institute of the University of Wroclaw (Poland). The data will be studied with respect to the energy transport and release responsible for heating the solar corona to temperatures of mega-Kelvins. In particular investigations will be focused on detection of possible high-frequency MHD waves in the solar corona. The scientific background of the project, technical details of the SECIS system modified specially for the Lomnicky Peak coronagraph, and inspection of the test data are described in the paper.

  15. The baryon acoustic oscillation peak: a flexible standard ruler

    CERN Document Server

    Roukema, Boudewijn F

    2016-01-01

    For about a decade, the baryon acoustic oscillation (BAO) peak at about 105 Mpc/h has provided a standard ruler test of the LCDM cosmological model, a member of the Friedmann--Lemaitre--Robertson--Walker (FLRW) family of cosmological models---according to which comoving space is rigid. However, general relativity does not require comoving space to be rigid. During the virialisation epoch, when the most massive structures form by gravitational collapse, it should be expected that comoving space evolves inhomogeneous curvature as structure grows. The BAO peak standard ruler should also follow this inhomogeneous evolution if the comoving rigidity assumption is false. This "standard" ruler has now been detected to be flexible, as expected under general relativity.

  16. Frequency interpretation of tidal peak in intracranial pressure wave.

    Science.gov (United States)

    Shahsavari, Sima; McKelvey, Tomas

    2008-01-01

    A new approach to locate different components of ICP signal for each cardiac induced ICP beat is presented. In this method an initial timing map is used to define the appropriate part of the ICP wave which should be searched for the specific component. In parallel a recently proposed method was used to decompose the ICP wave to its different frequency harmonics. This algorithm, which is based on tracking the amplitude of the harmonic components using Kalman filtering, brings both heart rate variability and cardiorespiratory interaction into account and provides good time and frequency resolution. Comparing the results of two methods for seventeen ICP records, each one hour long, it has been observed that the fundamental cardiac component has the most significant contribution in the construction of the tidal peak in ICP and therefore tracking of this harmonic could be informative of the tidal peak evolution over the time.

  17. Simulation of Peak Flows Using Remote Sensing Systems

    Science.gov (United States)

    Magaña Hernández, F.; Ba, K. M.; Guerra-Cobián, V.

    2013-05-01

    In this study we utilized remotely sensed data (radar and satellite precipitation products) to simulate the peak discharges of some storm events of the Escondido River. This is a poorly gauged watershed located in Northern Mexico, in the State of Coahuila and is a sub-basin of Rio Bravo, known also as Río Grande. The radar data are from NOAA (Radar KDFX located in Laughlin Air Force Base, Texas). We used two satellite product estimates PERSIANN and CMORPH. These three estimated precipitation products have been compared using the hydrologic model HEC-HMS to simulate the peak discharge. The results of the simulations show the importance of the use of this type of data in hydrologic modeling.

  18. Evaluations of pleasurable experiences: the peak-end rule.

    Science.gov (United States)

    Do, Amy M; Rupert, Alexander V; Wolford, George

    2008-02-01

    Prior research suggests that the addition of mild pain to an aversive event may lead people to prefer and directly choose more pain over less pain (Kahneman, Fredrickson, Schreiber, & Redelmeier, 1993). Kahneman et al. suggest that pain ratings are based on a combination of peak pain and final pain. Similarly, people rate a happy life that ends suddenly as being better than one with additional years of mild happiness (Diener, Wirtz, & Oishi, 2001), even though the former objectively consists of less pleasure than the latter. Applying these concepts to material goods, we investigated the impact of positivity and timing on the retrospective evaluations of material goods. We found strong evidence that the peak-end rule applies to both material goods and pain.

  19. Identification and separation of DNA mixtures using peak area information

    DEFF Research Database (Denmark)

    Cowell, R.G.; Lauritzen, Steffen Lilholt; Mortera, J.

    , whose profiles have been measured, have contributed to the mixture, but also to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our methodology is illustrated on case data examples and compared with alternative approaces......We show how probabilistic expert systems can be used to analyse forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for scertaining whether individuals....... The advantages are that identification and separation issues can be handled in a unified way within a single network model and the uncertainty associated with the analysis is quantified....

  20. Multiple peaks of species abundance distributions induced by sparse interactions

    CERN Document Server

    Obuchi, Tomoyuki; Tokita, Kei

    2016-01-01

    We investigate the replicator dynamics with "sparse" symmetric interactions which represent specialist-specialist interactions in ecological communities. By considering a large self interaction $u$, we conduct a perturbative expansion which manifests that the nature of the interactions has a direct impact on the species abundance distribution. The central results are all species coexistence in a realistic range of the model parameters and that a certain discrete nature of the interactions induces multiple peaks in the species abundance distribution, providing the possibility of theoretically explaining multiple peaks observed in various field studies. To get more quantitative information, we also construct a non-perturbative theory which becomes exact on tree-like networks if all the species coexist, providing exact critical values of $u$ below which extinct species emerge. Numerical simulations in various different situations are conducted and they clarify the robustness of the presented mechanism of all spe...

  1. Fluorescence applications in molecular neurobiology.

    Science.gov (United States)

    Taraska, Justin W; Zagotta, William N

    2010-04-29

    Macromolecules drive the complex behavior of neurons. For example, channels and transporters control the movements of ions across membranes, SNAREs direct the fusion of vesicles at the synapse, and motors move cargo throughout the cell. Understanding the structure, assembly, and conformational movements of these and other neuronal proteins is essential to understanding the brain. Developments in fluorescence have allowed the architecture and dynamics of proteins to be studied in real time and in a cellular context with great accuracy. In this review, we cover classic and recent methods for studying protein structure, assembly, and dynamics with fluorescence. These methods include fluorescence and luminescence resonance energy transfer, single-molecule bleaching analysis, intensity measurements, colocalization microscopy, electron transfer, and bimolecular complementation analysis. We present the principles of these methods, highlight recent work that uses the methods, and discuss a framework for interpreting results as they apply to molecular neurobiology.

  2. Lasing from fluorescent protein crystals.

    Science.gov (United States)

    Oh, Heon Jeong; Gather, Malte C; Song, Ji-Joon; Yun, Seok Hyun

    2014-12-15

    We investigated fluorescent protein crystals for potential photonic applications, for the first time to our knowledge. Rod-shaped crystals of enhanced green fluorescent protein (EGFP) were synthesized, with diameters of 0.5-2 μm and lengths of 100-200 μm. The crystals exhibit minimal light scattering due to their ordered structure and generate substantially higher fluorescence intensity than EGFP or dye molecules in solutions. The magnitude of concentration quenching in EGFP crystals was measured to be about 7-10 dB. Upon optical pumping at 485 nm, individual EGFP crystals located between dichroic mirrors generated laser emission with a single-mode spectral line at 513 nm. Our results demonstrate the potential of protein crystals as novel optical elements for self-assembled, micro- or nano-lasers and amplifiers in aqueous environment.

  3. Adjustment of Peak Streamflows of a Tropical River for Urbanization

    OpenAIRE

    Ata Amini; Thamer M. Ali; Abdul H.B. Ghazali; Bujang K. Huat

    2009-01-01

    Peak runoff from a catchment is influenced by many factors such as intensity and duration of rainfall, catchment topography, catchment shape, land use and other variables. For a particular catchment, landuse change and other human activities will alter the characteristic of catchment hydrograph. Problem statement: As a result of urbanization, the magnitude of floods occurring in a catchment increased. It was found that the land use change in the Langat River catchment has clear impact on annu...

  4. Sustained fixation induced changes in phoria and convergence peak velocity.

    Directory of Open Access Journals (Sweden)

    Eun H Kim

    Full Text Available PURPOSE: This study sought to investigate the influence of phoria adaptation on convergence peak velocity from responses located at different initial vergence positions. METHODS: Symmetrical 4° convergence step responses and near dissociated phoria (measured at 40 cm from the subject's midline were recorded from six subjects with normal binocular vision using an infrared limbus tracking system with a haploscope. Two different sustained fixations (1° and 16° convergent rotation along the subject's midline were used to study whether phoria had an influence on the peak velocity of convergence responses located at two initial vergence positions (1° or 'far' steps and 12° or 'near' steps. RESULTS: Phoria was significantly adapted after a sustained fixation task at near (16° and far (1° (p<0.002. A repeated measures ANOVA showed that convergence far steps were significantly faster than the near steps (p<0.03. When comparing convergence steps with the same initial vergence position, steps measured after near phoria adaptation were faster than responses after far adaptation (p<0.02. A regression analysis demonstrated that the change in phoria and the change in convergence peak velocity were significantly correlated for the far convergence steps (r = 0.97, p = 0.001. A weaker correlation was observed for the near convergence steps (r = 0.59, p = 0.20. CONCLUSION: As a result of sustained fixation, phoria was adapted and the peak velocity of the near and far convergence steps was modified. This study has clinical considerations since prisms, which evoke phoria adaptation, can be prescribed to help alleviate visual discomfort. Future investigations should include a systematic study of how prisms may influence convergence and divergence eye movements for those prescribed with prisms within their spectacles.

  5. Peak earthquake response of structures under multi-component excitations

    Institute of Scientific and Technical Information of China (English)

    Jianwei Song; Zach Liang; Yi-Lun Chu; George C.Lee

    2007-01-01

    Accurate estimation of the peak seismic responses of structures is important in earthquake resistant design.The internal force distributions and the seismic responses of structures are quite complex,since ground motions are multidirectional.One key issue is the uncertainty of the incident angle between the directions of ground motion and the reference axes of the structure.Different assumed seismic incidences can result in difierent peak values within the scope of design spectrum analysis for a given structure and earthquake ground motion record combination.Using time history analysis to determine the maximum structural responses excited by a given earthquake record requires repetitive calculations to determine the critical incident angle.This paper presents a transformation approach for relatively accurate and rapid determination of the maximum peak responses of a linear structure subjected to three-dimensional excitations within all possible seismic incident angles.The responses can be deformations,internal forces,strains and so on.An irregular building structure model is established using SAP2000 program.Several typical earthquake records and an artificial white noise are applied to the structure model to illustrate the variation of the maximum structural responses for different incident angles.Numerical results show that for many structural parameters,the variation can be greater than 100%.This method can be directly applied to time history analysis of structures using existing computer software to determine the peak responses without carrying out the analyses for all possible incident angles.It can also be used to verify and/or modify aseismic designs by using response spectrum analysis.

  6. Connection between ozone concentration and atmosphere circulation at peak Moussala

    Science.gov (United States)

    Nojarov, Peter; Ivanov, Peter; Kalapov, Ivo; Penev, Ilia; Drenska, Mirolujba

    2009-09-01

    Connection between ozone concentration and atmosphere circulation is investigated based on measurements at BEO station, peak Moussala (2,925 m a.s.l.), for the period 09 August 2006 to 29 January 2008. Ozone concentration data are collected with UV-analyzer “Environnement O3 42” and meteo data with weather station “Vaisala”. There are measurements of 7Be. Data from NOAA HYSPLIT model for particle trajectories are also used. Eight wind directions and three ranges of wind velocities are employed in the analysis. A comparison of ozone concentrations in upward and downward air transport according to HYSPLIT model is made. The number of cases with ozone concentration above 63 ppb has been counted. Mann-Whitney nonparametric test is employed as a basic statistical method. Correlation between atmosphere pressure and tropospheric ozone content is made. The same is done for 7Be and ozone. The main conclusion is that there is not any local or regional pollution effect detectable at peak Moussala, but most of the ozone measured is due to emissions of hydrocarbons and NO x over a larger region. There could be some regional sources of ozone building substances in southwest direction from peak Moussala. Air transported from the north quarter has higher ozone concentrations compared to the south quarter. In vertical direction, upward transport of air masses shows higher values of ozone concentration. Higher wind velocity is associated with low ozone concentrations at peak Moussala. The annual course of ozone concentration has summer maximum and winter minimum. There is right connection between air pressure and ozone concentration. The same is valid for the correlation between 7Be and ozone. Diurnal ozone course shows daytime maximum in winter and nighttime maximum in summer.

  7. Degradation of the Bragg peak due to inhomogeneities.

    Science.gov (United States)

    Urie, M; Goitein, M; Holley, W R; Chen, G T

    1986-01-01

    The rapid fall-off of dose at the end of range of heavy charged particle beams has the potential in therapeutic applications of sparing critical structures just distal to the target volume. Here we explored the effects of highly inhomogeneous regions on this desirable depth-dose characteristic. The proton depth-dose distribution behind a lucite-air interface parallel to the beam was bimodal, indicating the presence of two groups of protons with different residual ranges, creating a step-like depth-dose distribution at the end of range. The residual ranges became more spread out as the interface was angled at 3 degrees, and still more at 6 degrees, to the direction of the beam. A second experiment showed little significant effect on the distal depth-dose of protons having passed through a mosaic of teflon and lucite. Anatomic studies demonstrated significant effects of complex fine inhomogeneities on the end of range characteristics. Monoenergetic protons passing through the petrous ridges and mastoid air cells in the base of skull showed a dramatic degradation of the distal Bragg peak. In beams with spread out Bragg peaks passing through regions of the base of skull, the distal fall-off from 90 to 20% dose was increased from its nominal 6 to well over 32 mm. Heavy ions showed a corresponding degradation in their ends of range. In the worst case in the base of skull region, a monoenergetic neon beam showed a broadening of the full width at half maximum of the Bragg peak to over 15 mm (compared with 4 mm in a homogeneous unit density medium). A similar effect was found with carbon ions in the abdomen, where the full width at half maximum of the Bragg peak (nominally 5.5 mm) was found to be greater than 25 mm behind gas-soft-tissue interfaces. We address the implications of these data for dose computation with heavy charged particles.

  8. General Merrill A. McPeak Leadership and Organizational Change

    Science.gov (United States)

    2001-06-01

    GENERAL MERRILL A. MCPEAK LEADERSHIP AND ORGANIZATIONAL CHANGE BY MAJOR THOMAS A. BUSSIERE A THESIS PRESENTED TO THE...Covered (from... to) - Title and Subtitle General Merrill A. McPeak Leadership and Organizational Change Contract Number Grant Number Program Element...General McPeak�s leadership. The sections of each case focus on the particular issues associated with organizational change and leadership. The

  9. Martial arts striking hand peak acceleration, accuracy and consistency.

    Science.gov (United States)

    Neto, Osmar Pinto; Marzullo, Ana Carolina De Miranda; Bolander, Richard P; Bir, Cynthia A

    2013-01-01

    The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r(2)=0.456, p =0.032) and accuracy (r(2)=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r(2)=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.

  10. 36Cl bomb peak: comparison of modeled and measured data

    Directory of Open Access Journals (Sweden)

    A. Eichler

    2009-06-01

    Full Text Available The extensive nuclear bomb testing of the fifties and sixties and the final tests in the seventies caused a strong 36Cl peak that has been observed in ice cores world-wide. The measured 36Cl deposition fluxes in eight ice cores (Dye3, Fiescherhorn, Grenzgletscher, Guliya, Huascarán, North GRIP, Inylchek (Tien Shan and Berkner Island were compared with an ECHAM5-HAM general circulation model simulation (1952–1972. We find a good agreement between the measured and the modeled 36Cl fluxes assuming that the bomb test produced global 36Cl input was ~80 kg. The model simulation indicates that the fallout of the bomb test produced 36Cl is largest in the subtropics and mid-latitudes due to the strong stratosphere-troposphere exchange. In Greenland the 36Cl bomb signal is quite large due to the relatively high precipitation rate. In Antarctica the 36Cl bomb peak is small but is visible even in the driest areas. The model suggests that the large bomb tests in the Northern Hemisphere are visible around the globe but the later (end of sixties and early seventies smaller tests in the Southern Hemisphere are much less visible in the Northern Hemisphere. The question of how rapidly and to what extent the bomb produced 36Cl is mixed between the hemispheres depends on the season of the bomb test. The model results give an estimate of the amplitude of the bomb peak around the globe.

  11. 36Cl bomb peak: comparison of modeled and measured data

    Directory of Open Access Journals (Sweden)

    A. Eichler

    2009-01-01

    Full Text Available The extensive nuclear bomb testing of the fifties and sixties and the final tests in the seventies caused a strong 36Cl peak that has been observed in ice cores world-wide. The measured 36Cl deposition fluxes in eight ice cores (Dye3, Fiescherhorn, Grenzgletscher, Guliya, Huascarán, North GRIP, Inylchek (Tien Shan and Berkner Island were compared with an ECHAM5-HAM general circulation model simulation (1952–1972. We find a good agreement between the measured and the modeled 36Cl fluxes assuming that the bomb test produced global 36Cl input was ~80 kg. The model simulation indicates that the fallout of the bomb test produced 36Cl is largest in the subtropics and mid-latitudes due to the strong stratosphere-troposphere exchange. In Greenland the 36Cl bomb signal is quite large due to the relatively high precipitation rate. In Antarctica the 36Cl bomb peak is small but is visible even in the driest areas. The model suggests that the large bomb tests in the Northern Hemisphere are visible around the globe but the later (end of sixties and early seventies smaller tests in the Southern Hemisphere are much less visible in the Northern Hemisphere. The question of how rapidly and to what extent the bomb produced 36Cl is mixed between the hemispheres depends on the season of the bomb test. The model results give an estimate of the amplitude of the bomb peak around the globe.

  12. Mineral Resources: Reserves, Peak Production and the Future

    Directory of Open Access Journals (Sweden)

    Lawrence D. Meinert

    2016-02-01

    Full Text Available The adequacy of mineral resources in light of population growth and rising standards of living has been a concern since the time of Malthus (1798, but many studies erroneously forecast impending peak production or exhaustion because they confuse reserves with “all there is”. Reserves are formally defined as a subset of resources, and even current and potential resources are only a small subset of “all there is”. Peak production or exhaustion cannot be modeled accurately from reserves. Using copper as an example, identified resources are twice as large as the amount projected to be needed through 2050. Estimates of yet-to-be discovered copper resources are up to 40-times more than currently-identified resources, amounts that could last for many centuries. Thus, forecasts of imminent peak production due to resource exhaustion in the next 20–30 years are not valid. Short-term supply problems may arise, however, and supply-chain disruptions are possible at any time due to natural disasters (earthquakes, tsunamis, hurricanes or political complications. Needed to resolve these problems are education and exploration technology development, access to prospective terrain, better recycling and better accounting of externalities associated with production (pollution, loss of ecosystem services and water and energy use.

  13. Calibration of {sup 133}Ba by Sum-Peak Method

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.L. da; Delgado, J.U.; Poledna, R.; Trindade, O.L.; Veras, E.V. de; Santos, A.; Rangel, J., E-mail: ronaldo@ird.gov.br, E-mail: delgado@ird.gov.br, E-mail: poledna@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Almeida, M.C.M, E-mail: marcandida@yahoo.com.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    A calibration laboratory should have several methods of measurement in order to ensure robustness on the values applied. The National Laboratory for Metrology of Ionizing Radiation, (LNMRI IRD), provides gamma sources of radionuclide in various geometries and standardized in activity with reduced uncertainties. Some absolute and relative methods of calibrations could be used routinely. Relative methods require standards to determine the activity of sample to be calibrated, while the absolute methods do not need, simply make the counting and the calculation of the activity is obtained directly. The great advantage of calibrations of radionuclides by absolute method is the accuracy and low uncertainties. {sup 133}Ba is a radionuclide enough used in research laboratories and calibration of detectors for environmental analysis and, according to the scheme, it decays 100% by electron capture and emits about 14 energy gamma and X-ray lines, forming several coincidences. However, the classical methods of absolute measurement, as coincidence 4 πβ-γ have difficulty to calibrate {sup 133}Ba due to its complex decay scheme. The sum-peak method, developed by Brickman, could allow this calibration. It is used for radionuclide calibration that emits at least two photons in coincidence. Therefore, it was developed a methodology that combines gamma spectrometry technique with sum-peak method to standardize {sup 133}Ba samples. Activity results obtained proved compatible, with uncertainties of less than 1%, and, when compared with other methods of calibration, sum-peak demonstrated the feasibility of this methodology, particularly, for simplicity and effectiveness. (author)

  14. R-peaks detection based on stationary wavelet transform.

    Science.gov (United States)

    Merah, M; Abdelmalik, T A; Larbi, B H

    2015-10-01

    Automatic detection of the QRS complexes/R-peaks in an electrocardiogram (ECG) signal is the most important step preceding any kind of ECG processing and analysis. The performance of these systems heavily relies on the accuracy of the QRS detector. The objective of present work is to drive a new robust method based on stationary wavelet transform (SWT) for R-peaks detection. The decimation of the coefficients at each level of the transformation algorithm is omitted, more samples in the coefficient sequences are available and hence a better outlier detection can be performed. Using the information of local maxima, minima and zero crossings of the fourth SWT coefficient detail, the proposed algorithm identifies the significant points for detection and delineation of the QRS complexes, as well as detection and identification of the QRS individual waves peaks of the pre-processed ECG signal. Various experimental results show that the proposed algorithm exhibits reliable QRS detection as well as accurate ECG delineation, achieving excellent performance on different databases, on the MIT-BIH database (Se=99.84%, P=99.88%), on the QT Database (Se=99.94%, P=99.89%) and on MIT-BIH Noise Stress Test Database, (Se=95.30%, P=93.98%). Reliability and accuracy are close to the highest among the ones obtained in other studies. Experiments results being satisfactory, the SWT may represent a novel QRS detection tool, for a robust ECG signal analysis.

  15. Predictors of the peak width for networks with exponential links

    Science.gov (United States)

    Troutman, B.M.; Karlinger, M.R.

    1989-01-01

    We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations of S and T given network magnitude N and given mainstream length H. In addition, a simulation study is performed to examine various predictors of S and T, including N, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor of S is N, of T is H, and of the scaled peak (S divided by the area under the width function) is H. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predicting S and T despite probable violations of the original assumptions. ?? 1989 Springer-Verlag.

  16. Silicon Burning: Formation of the Iron Peak Nuclei

    Science.gov (United States)

    Hix, Wm. Raphael; Thielemann, Friederich-Karl

    1993-12-01

    As the most tightly bound nuclei, the 'Iron Peak' nuclei are the culmination of nuclear energy generation in astrophysical environments. Our re-examination of silicon burning, the mechanism by which the nuclei of the iron peak are produced, has revealed a number of potential improvements in the treatment of this ultimate stage of astrophysical nuclear energy generation. Previous work on Nuclear Statistical Equilibrium (NSE), the end state of silicon burning, has neglected the effect that Coulomb screening of capture reactions and their reverse reactions has on the equilibrium distribution, or assumed that these effects cancel, leaving an abundance distribution identical to that predicted in the absence of such screening. We find that the proper treatment of the screening of nuclear reactions in Nuclear Statistical Equilibrium (NSE), can produce significant differences in the relative abundances of the nuclei produced. This is particularly true at high density. Further, results gleaned from simulation work done with a large nuclear network (300 nuclei and 3000 reactions) and from independent calculations of NSE abundance distributions, offer new insights into the quasi-equilibrium mechanism and the approach to NSE. We will discuss methods which use this quasi-equilibrium mechanism to preserve the most important features of the large nuclear network calculations at a significant improvement in computational speed. Such improved methods are ideally suited for hydro- dynamic calculations which involve the production of iron peak nuclei, where the larger network calculation proves unmanageable.

  17. A new record peak luminosity for the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Two weeks of dedicated machine development paid off last weekend when the LHC ran for physics with three nominal intensity (∼1011 protons) bunches in each beam.   This brought a new record peak luminosity of around 8×1029 cm-2 s-1, and allowed the LHC to double the integrated luminosity delivered to the experiments since 30 March from 16 to 32 inverse nanobarns over the weekend. After a few more fills in this configuration, the number of bunches will be raised to six per beam, which will in turn allow the peak luminosity to break the 1030 cm-2 s-1 barrier for the first time, well on the way to achieving the 2010 objective of 1032 cm-2 s-1. This peak luminosity goal requires 800 nominal bunches per beam squeezed to a beta of 3.5 metres. The plan for 2011 is to run the LHC in this configuration over about 10 months, thus achieving the objective of recording one inverse femtobarn of data in total. The machine development period also allowed the TOTEM detectors to be set up with 45...

  18. Projectile remnants in central peaks of lunar impact craters

    Science.gov (United States)

    Yue, Z.; Johnson, B. C.; Minton, D. A.; Melosh, H. J.; di, K.; Hu, W.; Liu, Y.

    2013-06-01

    The projectiles responsible for the formation of large impact craters are often assumed to melt or vaporize during the impact, so that only geochemical traces or small fragments remain in the final crater. In high-speed oblique impacts, some projectile material may survive, but this material is scattered far down-range from the impact site. Unusual minerals, such as magnesium-rich spinel and olivine, observed in the central peaks of many lunar craters are therefore attributed to the excavation of layers below the lunar surface. Yet these minerals are abundant in many asteroids, meteorites and chondrules. Here we use a numerical model to simulate the formation of impact craters and to trace the fate of the projectile material. We find that for vertical impact velocities below about 12kms-1, the projectile may both survive the impact and be swept back into the central peak of the final crater as it collapses, although it would be fragmented and strongly deformed. We conclude that some unusual minerals observed in the central peaks of many lunar impact craters could be exogenic in origin and may not be indigenous to the Moon.

  19. Cycle Average Peak Fuel Temperature Prediction Using CAPP/GAMMA+

    Energy Technology Data Exchange (ETDEWEB)

    Tak, Nam-il; Lee, Hyun Chul; Lim, Hong Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In order to obtain a cycle average maximum fuel temperature without rigorous efforts, a neutronics/thermo-fluid coupled calculation is needed with depletion capability. Recently, a CAPP/GAMMA+ coupled code system has been developed and the initial core of PMR200 was analyzed using the CAPP/GAMMA+ code system. The GAMMA+ code is a system thermo-fluid analysis code and the CAPP code is a neutronics code. The General Atomics proposed that the design limit of the fuel temperature under normal operating conditions should be a cycle-averaged maximum value. Nonetheless, the existing works of Korea Atomic Energy Research Institute (KAERI) only calculated the maximum fuel temperature at a fixed time point, e.g., the beginning of cycle (BOC) just because the calculation capability was not ready for a cycle average value. In this work, a cycle average maximum fuel temperature has been calculated using CAPP/GAMMA+ code system for the equilibrium core of PMR200. The CAPP/GAMMA+ coupled calculation was carried out for the equilibrium core of PMR 200 from BOC to EOC to obtain a cycle average peak fuel temperature. The peak fuel temperature was predicted to be 1372 .deg. C near MOC. However, the cycle average peak fuel temperature was calculated as 1181 .deg. C, which is below the design target of 1250 .deg. C.

  20. The bias of weighted dark matter halos from peak theory

    CERN Document Server

    Verde, Licia; Simpson, Fergus; Alvarez-Gaume, Luis; Heavens, Alan; Matarrese, Sabino

    2014-01-01

    We give an analytical form for the weighted correlation function of peaks in a Gaussian random field. In a cosmological context, this approach strictly describes the formation bias and is the main result here. Nevertheless, we show its validity and applicability to the evolved cosmological density field and halo field, using Gaussian random field realisations and dark matter N-body numerical simulations. Using this result from peak theory we compute the bias of peaks (and dark matter halos) and show that it reproduces results from the simulations at the ${\\mathcal O}(10\\%)$ level. Our analytical formula for the bias predicts a scale-dependent bias with two characteristics: a broad band shape which, however, is most affected by the choice of weighting scheme and evolution bias, and a more robust, narrow feature localised at the BAO scale, an effect that is confirmed in simulations. This scale-dependent bias smooths the BAO feature but, conveniently, does not move it. We provide a simple analytic formula to des...

  1. [Laser Induced Fluorescence Spectroscopic Analysis of Aromatics from One Ring to Four Rings].

    Science.gov (United States)

    Zhang, Peng; Liu, Hai-feng; Yue, Zong-yu; Chen, Bei-ling; Yao, Ming-fa

    2015-06-01

    In order to distinguish small aromatics preferably, a Nd : YAG Laser was used to supply an excitation laser, which was adjusted to 0.085 J x cm(-2) at 266 nm. Benzene, toluene, naphthalene, phenanthrene, anthracene, pyrene and chrysene were used as the representative of different rings aromatics. The fluorescence emission spectra were researched for each aromatic hydrocarbon and mixtures by Laser induced fluorescence (LIF). Results showed that the rings number determined the fluorescence emission spectra, and the structure with same rings number did not affect the emission fluorescence spectrum ranges. This was due to the fact that the absorption efficiency difference at 266 nm resulted in that the fluorescence intensities of each aromatic hydrocarbon with same rings number were different and the fluorescence intensities difference were more apparently with aromatic ring number increasing. When the absorption efficiency was similar at 266 nm and the concentrations of each aromatic hydrocarbon were same, the fluorescence intensities were increased with aromatic ring number increasing. With aromatic ring number increasing, the fluorescence spectrum and emission peak wavelength were all red-shifted from ultraviolet to visible and the fluorescence spectrum range was also wider as the absorption efficiency was similar. The fluorescence emission spectra from one to four rings could be discriminated in the following wavelengths, 275 to 320 nm, 320 to 375 nm, 375 to 425 nm, 425 to 556 nm, respectively. It can be used for distinguish the type of the polycyclic aromatic hydrocarbons (PAHs) as it exists in single type. As PAHs are usually exist in a variety of different rings number at the same time, the results for each aromatic hydrocarbon may not apply to the aromatic hydrocarbon mixtures. For the aromatic hydrocarbon mixtures, results showed that the one- or two-ring PAHs in mixtures could not be detected by fluorescence as three- or four-ring PAHs existed in mixture

  2. Going Viral with Fluorescent Proteins.

    Science.gov (United States)

    Costantini, Lindsey M; Snapp, Erik L

    2015-10-01

    Many longstanding questions about dynamics of virus-cell interactions can be answered by combining fluorescence imaging techniques with fluorescent protein (FP) tagging strategies. Successfully creating a FP fusion with a cellular or viral protein of interest first requires selecting the appropriate FP. However, while viral architecture and cellular localization often dictate the suitability of a FP, a FP's chemical and physical properties must also be considered. Here, we discuss the challenges of and offer suggestions for identifying the optimal FPs for studying the cell biology of viruses.

  3. Fluorescence for high school students

    CERN Document Server

    Schultheiss, Niek G

    2012-01-01

    In a not obligatory series of lessons for high school students in the Netherlands we discuss the fluorescence aspects of anthracene. These lessons were developed because HiSPARC (High school Project on Astrophysics Research with Cosmics) detection of cosmic rays are available for different secondary schools. With the help of special designed scintillator detection stations, containing anthracene, cosmic rays can be detected. Fluorescence of anthracene is one of the topics discussed in these series of extra curricular lessons aimed at excellent pupils working on cosmic radiation within the HiSPARC - project.

  4. Multichromophoric sugar for fluorescence photoswitching

    Directory of Open Access Journals (Sweden)

    Stéphane Maisonneuve

    2014-06-01

    Full Text Available A multichromophoric glucopyranoside 2 bearing three dicyanomethylenepyran (DCM fluorophores and one diarylethene (DAE photochrome has been prepared by Cu(I-catalyzed alkyne–azide cycloaddition reaction. The fluorescence of 2 was switched off upon UV irradiation, in proportion with the open to closed form (OF to CF conversion extent of the DAE moiety. A nearly 100% Förster-type resonance energy transfer (FRET from all three DCM moieties to a single DAE (in its CF moiety was achieved. Upon visible irradiation, the initial fluorescence intensity was recovered. The observed photoswiching is reversible, with excellent photo resistance.

  5. Climate change and peak demand for electricity: Evaluating policies for reducing peak demand under different climate change scenarios

    Science.gov (United States)

    Anthony, Abigail Walker

    This research focuses on the relative advantages and disadvantages of using price-based and quantity-based controls for electricity markets. It also presents a detailed analysis of one specific approach to quantity based controls: the SmartAC program implemented in Stockton, California. Finally, the research forecasts electricity demand under various climate scenarios, and estimates potential cost savings that could result from a direct quantity control program over the next 50 years in each scenario. The traditional approach to dealing with the problem of peak demand for electricity is to invest in a large stock of excess capital that is rarely used, thereby greatly increasing production costs. Because this approach has proved so expensive, there has been a focus on identifying alternative approaches for dealing with peak demand problems. This research focuses on two approaches: price based approaches, such as real time pricing, and quantity based approaches, whereby the utility directly controls at least some elements of electricity used by consumers. This research suggests that well-designed policies for reducing peak demand might include both price and quantity controls. In theory, sufficiently high peak prices occurring during periods of peak demand and/or low supply can cause the quantity of electricity demanded to decline until demand is in balance with system capacity, potentially reducing the total amount of generation capacity needed to meet demand and helping meet electricity demand at the lowest cost. However, consumers need to be well informed about real-time prices for the pricing strategy to work as well as theory suggests. While this might be an appropriate assumption for large industrial and commercial users who have potentially large economic incentives, there is not yet enough research on whether households will fully understand and respond to real-time prices. Thus, while real-time pricing can be an effective tool for addressing the peak load

  6. Modeling chlorophyll a fluorescence transient: relation to photosynthesis.

    Science.gov (United States)

    Stirbet, A; Riznichenko, G Yu; Rubin, A B; Govindjee

    2014-04-01

    To honor Academician Alexander Abramovitch Krasnovsky, we present here an educational review on the relation of chlorophyll a fluorescence transient to various processes in photosynthesis. The initial event in oxygenic photosynthesis is light absorption by chlorophylls (Chls), carotenoids, and, in some cases, phycobilins; these pigments form the antenna. Most of the energy is transferred to reaction centers where it is used for charge separation. The small part of energy that is not used in photochemistry is dissipated as heat or re-emitted as fluorescence. When a photosynthetic sample is transferred from dark to light, Chl a fluorescence (ChlF) intensity shows characteristic changes in time called fluorescence transient, the OJIPSMT transient, where O (the origin) is for the first measured minimum fluorescence level; J and I for intermediate inflections; P for peak; S for semi-steady state level; M for maximum; and T for terminal steady state level. This transient is a real signature of photosynthesis, since diverse events can be related to it, such as: changes in redox states of components of the linear electron transport flow, involvement of alternative electron routes, the build-up of a transmembrane pH gradient and membrane potential, activation of different nonphotochemical quenching processes, activation of the Calvin-Benson cycle, and other processes. In this review, we present our views on how different segments of the OJIPSMT transient are influenced by various photosynthetic processes, and discuss a number of studies involving mathematical modeling and simulation of the ChlF transient. A special emphasis is given to the slower PSMT phase, for which many studies have been recently published, but they are less known than on the faster OJIP phase.

  7. Trends in peak flows of selected streams in Kansas

    Science.gov (United States)

    Rasmussen, T.J.; Perry, C.A.

    2001-01-01

    The possibility of a systematic change in flood potential led to an investigation of trends in the magnitude of annual peak flows in Kansas. Efficient design of highway bridges and other flood-plain structures depends on accurate understanding of flood characteristics. The Kendall's tau test was used to identify trends at 40 stream-gaging stations during the 40-year period 1958-97. Records from 13 (32 percent) of the stations showed significant trends at the 95-percent confidence level. Only three of the records (8 percent) analyzed had increasing trends, whereas 10 records (25 percent) had decreasing trends, all of which were for stations located in the western one-half of the State. An analysis of flow volume using mean annual discharge at 29 stations in Kansas resulted in 6 stations (21 percent) with significant trends in flow volumes. All six trends were decreasing and occurred in the western one-half of the State. The Kendall's tau test also was used to identify peak-flow trends over the entire period of record for 54 stream-gaging stations in Kansas. Of the 23 records (43 percent) showing significant trends, 16 (30 percent) were decreasing, and 7 (13 percent) were increasing. The trend test then was applied to 30-year periods moving in 5-year increments to identify time periods within each station record when trends were occurring. Systematic changes in precipitation patterns and long-term declines in ground-water levels in some stream basins may be contributing to peak-flow trends. To help explain the cause of the streamflow trends, the Kendall's tau test was applied to total annual precipitation and ground-water levels in Kansas. In western Kansas, the lack of precipitation and presence of decreasing trends in ground-water levels indicated that declining water tables are contributing to decreasing trends in peak streamflow. Declining water tables are caused by ground-water withdrawals and other factors such as construction of ponds and terraces. Peak

  8. Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila; Xu, Peng

    2006-04-06

    California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. (3) Determine how customers

  9. Automated Critical Peak Pricing Field Tests: Program Descriptionand Results

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann; Watson, David; Motegi, Naoya; Kiliccote, Sila; Xu, Peng

    2006-04-06

    California utilities have been exploring the use of critical peak prices (CPP) to help reduce needle peaks in customer end-use loads. CPP is a form of price-responsive demand response (DR). Recent experience has shown that customers have limited knowledge of how to operate their facilities in order to reduce their electricity costs under CPP (Quantum 2004). While the lack of knowledge about how to develop and implement DR control strategies is a barrier to participation in DR programs like CPP, another barrier is the lack of automation of DR systems. During 2003 and 2004, the PIER Demand Response Research Center (DRRC) conducted a series of tests of fully automated electric demand response (Auto-DR) at 18 facilities. Overall, the average of the site-specific average coincident demand reductions was 8% from a variety of building types and facilities. Many electricity customers have suggested that automation will help them institutionalize their electric demand savings and improve their overall response and DR repeatability. This report focuses on and discusses the specific results of the Automated Critical Peak Pricing (Auto-CPP, a specific type of Auto-DR) tests that took place during 2005, which build on the automated demand response (Auto-DR) research conducted through PIER and the DRRC in 2003 and 2004. The long-term goal of this project is to understand the technical opportunities of automating demand response and to remove technical and market impediments to large-scale implementation of automated demand response (Auto-DR) in buildings and industry. A second goal of this research is to understand and identify best practices for DR strategies and opportunities. The specific objectives of the Automated Critical Peak Pricing test were as follows: (1) Demonstrate how an automated notification system for critical peak pricing can be used in large commercial facilities for demand response (DR). (2) Evaluate effectiveness of such a system. (3) Determine how customers

  10. Use of fluorescence EEM to monitor the removal of emerging contaminants in full scale wastewater treatment plants.

    Science.gov (United States)

    Sgroi, Massimiliano; Roccaro, Paolo; Korshin, Gregory V; Greco, Valentina; Sciuto, Sebastiano; Anumol, Tarun; Snyder, Shane A; Vagliasindi, Federico G A

    2017-02-05

    This study investigated the applicability of different techniques for fluorescence excitation/emission matrices data interpretations, including peak-picking method, fluorescence regional integration and PARAFAC modelling, to act as surrogates in predicting emerging trace organic compounds (ETOrCs) removal during conventional wastewater treatments that usually comprise primary and secondary treatments. Results showed that fluorescence indexes developed using alternative methodologies but indicative of a same dissolved organic matter component resulted in similar predictions of the removal of the target compounds. The peak index defined by the excitation/emission wavelength positions (λex/λem) 225/290nm and related to aromatic proteins and tyrosine-like fluorescence was determined to be a particularly suitable surrogate for monitoring ETOrCs that had very high removal rates (average removal >70%) (i.e., triclosan, caffeine and ibuprofen). The peak index defined by λex/λem=245/440nm and the PARAFAC component with wavelength of the maxima λex/λem=245, 350/450, both identified as humic-like fluorescence, were found remarkably well correlated with ETOrCs such as atenolol, naproxen and gemfibrozil that were moderately removed (51-70% average removal). Finally, the PARAFAC component with wavelength of the maxima λex/λem=<240, 315/380 identified as microbial humic-like fluorescence was the only index correlated with the removal of the antibiotic trimethoprim (average removal 68%).

  11. Fluorescence Imaging Study of Impinging Underexpanded Jets

    Science.gov (United States)

    Inman, Jennifer A.; Danehy, Paul M.; Nowak, Robert J.; Alderfer, David W.

    2008-01-01

    An experiment was designed to create a simplified simulation of the flow through a hole in the surface of a hypersonic aerospace vehicle and the subsequent impingement of the flow on internal structures. In addition to planar laser-induced fluorescence (PLIF) flow visualization, pressure measurements were recorded on the surface of an impingement target. The PLIF images themselves provide quantitative spatial information about structure of the impinging jets. The images also help in the interpretation of impingement surface pressure profiles by highlighting the flow structures corresponding to distinctive features of these pressure profiles. The shape of the pressure distribution along the impingement surface was found to be double-peaked in cases with a sufficiently high jet-exit-to-ambient pressure ratio so as to have a Mach disk, as well as in cases where a flow feature called a recirculation bubble formed at the impingement surface. The formation of a recirculation bubble was in turn found to depend very sensitively upon the jet-exit-to-ambient pressure ratio. The pressure measured at the surface was typically less than half the nozzle plenum pressure at low jet pressure ratios and decreased with increasing jet pressure ratios. Angled impingement cases showed that impingement at a 60deg angle resulted in up to a factor of three increase in maximum pressure at the plate compared to normal incidence.

  12. The aggregation behavior of native collagen in dilute solution studied by intrinsic fluorescence and external probing

    Science.gov (United States)

    Wu, Kun; Liu, Wentao; Li, Guoying

    2013-02-01

    The aggregation behavior of type I collagen in acid solutions with the concentrations covering a range of 0.06-1.50 mg/mL was studied utilizing both of the fluorescence resonance energy transfer (FRET) between the phenylalanine and tyrosine residues and the external probing of 1,8-anilinonaphthalene sulfonate (ANS). FRET at 0.30 mg/mL showed the distance among collagen monomers was within 10 nm without the obvious aggregates formed. The predominance of tyrosine fluorescence in FRET in the range of 0.45-0.75 mg/mL identified the existence of collagen aggregates companied with the formation of hydrophobic microdomains revealed by the change of the fluorescence of ANS. The blue-shift of tyrosine fluorescence from 303 to 293 nm for 0.90-1.50 mg/mL dedicated the formation of high order aggregates. The results from the two-phase diagrams of the intrinsic fluorescence for the guanidine hydrochloride-induced unfolding of collagen confirmed these conclusions. By the two-dimensional correlation analysis for the intrinsic fluorescence of collagen solutions of 0.45, 0.75 and 1.05 mg/mL, the probable characteristic fluorescence peaks for the interactions of proline-aromatic (CH ˜ π) among the collagen molecules were found at 298 and 316 nm.

  13. Biomolecule-to-fluorescent-color encoder: modulation of fluorescence emission via DNA structural changes.

    Science.gov (United States)

    Nishimura, Takahiro; Ogura, Yusuke; Yamada, Kenji; Ohno, Yuko; Tanida, Jun

    2014-07-01

    A biomolecule-to-fluorescent-color (B/F) encoder for optical readout of biomolecular information is proposed. In the B/F encoder, a set of fluorescence wavelengths and their intensity levels are used for coding of a biomolecular signal. A hybridization chain reaction of hairpin DNAs labeled with fluorescent reporters was performed to generate the fluorescence color codes. The fluorescence is modulated via fluorescence resonance energy transfer, which is controlled by DNA structural changes. The results demonstrate that fluorescent color codes can be configured based on two wavelengths and five intensities using the B/F encoder, and the assigned codes can be retrieved via fluorescence measurements.

  14. Fluorescence for high school students

    NARCIS (Netherlands)

    Schultheiss, N.G.; Kool, T.W.

    2012-01-01

    In a not obligatory series of lessons for high school students in the Netherlands we discuss the fluorescence aspects of anthracene. These lessons were developed because HiSPARC (High school Project on Astrophysics Research with Cosmics) detection of cosmic rays are available for different secondary

  15. Development of Sealed Fluorescence Spectrometer

    Institute of Scientific and Technical Information of China (English)

    QIAN; Hong-juan; ZHANG; Li-hua; LIU; Huan-liang; FAN; De-jun

    2012-01-01

    <正>In nuclear fuel reprocessing, the fluorescent analytical instrument can be used to analyze various trace elements, such as boron and thorium in uranium product. Due to the high radioactivity, strong acidity, fatal toxic and complex components of spent nuclear fuel reprocessing sample, analytical works become more difficult and instruments used can be damaged easier.

  16. A fluorescent probe for ecstasy.

    Science.gov (United States)

    Masseroni, D; Biavardi, E; Genovese, D; Rampazzo, E; Prodi, L; Dalcanale, E

    2015-08-18

    A nanostructure formed by the insertion in silica nanoparticles of a pyrene-derivatized cavitand, which is able to specifically recognize ecstasy in water, is presented. The absence of effects from interferents and an efficient electron transfer process occurring after complexation of ecstasy, makes this system an efficient fluorescent probe for this popular drug.

  17. Studying Photosynthesis by Measuring Fluorescence

    Science.gov (United States)

    Sanchez, Jose Francisco; Quiles, Maria Jose

    2006-01-01

    This paper describes an easy experiment to study the absorption and action spectrum of photosynthesis, as well as the inhibition by heat, high light intensity and the presence of the herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the photosynthetic process. The method involves measuring the chlorophyll fluorescence emitted by intact…

  18. In vivo fluorescence lifetime tomography

    Science.gov (United States)

    Nothdurft, Ralph E.; Patwardhan, Sachin V.; Akers, Walter; Ye, Yunpeng; Achilefu, Samuel; Culver, Joseph P.

    2009-03-01

    Local molecular and physiological processes can be imaged in vivo through perturbations in the fluorescence lifetime (FLT) of optical imaging agents. In addition to providing functional information, FLT methods can quantify specific molecular events and multiplex diagnostic and prognostic information. We have developed a fluorescence lifetime diffuse optical tomography (DOT) system for in vivo preclinical imaging. Data is captured using a time-resolved intensified charge coupled device (ICCD) system to measure fluorescence excitation and emission in the time domain. Data is then converted to the frequency domain, and we simultaneously reconstruct images of yield and lifetime using an extension to the normalized Born approach. By using differential phase measurements, we demonstrate DOT imaging of short lifetimes (from 350 ps) with high precision (+/-5 ps). Furthermore, this system retains the efficiency, speed, and flexibility of transmission geometry DOT. We demonstrate feasibility of FLT-DOT through a progressive series of experiments. Lifetime range and repeatability are first measured in phantoms. Imaging of subcutaneous implants then verifies the FLT-DOT approach in vivo in the presence of inhomogeneous optical properties. Use in a common research scenario is ultimately demonstrated by imaging accumulation of a targeted near-infrared (NIR) fluorescent-labeled peptide probe (cypate-RGD) in a mouse with a subcutaneous tumor.

  19. Fluorescence diagnostics in oncological gynecology

    Science.gov (United States)

    Belyaeva, Ludmila A.; Adamyan, Leila V.; Kozachenko, Vladimir P.; Stratonnikov, Alexander A.; Stranadko, Eugene F.; Loschenov, Victor B.

    2003-10-01

    The method of fluorescent diagnostics (FD) of tumors is a promising tool that may allow to increase sensitivity of tumor detection especially at initial stages. One of the most promising photosensitizers today is 5-aminolevulinic acid (5-ALA) that, actually, is not photosensitizer itself but precursor of protoporphyrin IX (PpIX). This paper deals with cancer diagnostics in gynecology by means of ALA-induced Pp IX laser-fluorescence spectroscopy. The tissue fluorescence spectra in vivo were studied in patients with various pathologies of ovaries, uterine and vulva after 5-aminolevulinic acid administration. It was shown that different pathologies varies in accumulation of Pp IX. Coefficient of fluorescence kf for normal tissue is not high, but exceptions are endometrium and mucous membrane of uterine tubes. Benign tumors of uterus and ovary have low values of kf, but polyps of endometrium exhibit high kf. Optical express-biopsy is important for diagnosis of ovarian cancer and micrometastatic spread. Coefficients of diagnostic contrast were determined for cancer of endometrium, cervical cancer, vulvar cancer.

  20. Fluorescent Labeling of Nanometer Hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    Yuan ZHANG; Yuan YUAN; Changsheng LIU

    2008-01-01

    A novel surface treatment method using 3-aminopropyltriethoxysilane (AMPTES), was developed to immobilize the fluorescein molecule on nano-HAP (nanometer hydroxyapatite) powders. By pretreating the nano-HAP powders surface with AMPTES, fluorescein, chosen on the basis of the chemical structure of the nano- HAP powders, could be bound to the nano-HAP powders surface. The chemical compositions of nano-HAP before and after being labeled were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The morphology, phase composition, and the fluorescence characteristics of the nano-HAP powders with and without staining were also investigated. The FTIR and XPS results revealed that fiuorescein had been successfully immobilized on the surface of AMPTES-bound nano-HAP powders via the acylamide bond formation between the -COOH of fluorescein and the -NH2 of AMPTES. The labeled nano-HAP powders possessed strong fluorescent intensity with a little deviation from the maximum emission wavelength of fluorescein. But the morphology and phase composition had no obvious alteration. Under fluorescence microscopy, the labeled nano-HAP powders., even after 24 h cell incubation, exhibited strong fluorescence.

  1. High-throughput retrotransposon-based fluorescent markers: improved information content and allele discrimination

    Directory of Open Access Journals (Sweden)

    Baker David

    2009-07-01

    Full Text Available Abstract Background Dense genetic maps, together with the efficiency and accuracy of their construction, are integral to genetic studies and marker assisted selection for plant breeding. High-throughput multiplex markers that are robust and reproducible can contribute to both efficiency and accuracy. Multiplex markers are often dominant and so have low information content, this coupled with the pressure to find alternatives to radio-labelling, has led us to adapt the SSAP (sequence specific amplified polymorphism marker method from a 33P labelling procedure to fluorescently tagged markers analysed from an automated ABI 3730 xl platform. This method is illustrated for multiplexed SSAP markers based on retrotransposon insertions of pea and is applicable for the rapid and efficient generation of markers from genomes where repetitive element sequence information is available for primer design. We cross-reference SSAP markers previously generated using the 33P manual PAGE system to fluorescent peaks, and use these high-throughput fluorescent SSAP markers for further genetic studies in Pisum. Results The optimal conditions for the fluorescent-labelling method used a triplex set of primers in the PCR. These included a fluorescently labelled specific primer together with its unlabelled counterpart, plus an adapter-based primer with two bases of selection on the 3' end. The introduction of the unlabelled specific primer helped to optimise the fluorescent signal across the range of fragment sizes expected, and eliminated the need for extensive dilutions of PCR amplicons. The software (GeneMarker Version 1.6 used for the high-throughput data analysis provided an assessment of amplicon size in nucleotides, peak areas and fluorescence intensity in a table format, so providing additional information content for each marker. The method has been tested in a small-scale study with 12 pea accessions resulting in 467 polymorphic fluorescent SSAP markers of which

  2. Fluorescence fingerprint as an instrumental assessment of the sensory quality of tomato juices.

    Science.gov (United States)

    Trivittayasil, Vipavee; Tsuta, Mizuki; Imamura, Yoshinori; Sato, Tsuneo; Otagiri, Yuji; Obata, Akio; Otomo, Hiroe; Kokawa, Mito; Sugiyama, Junichi; Fujita, Kaori; Yoshimura, Masatoshi

    2016-03-15

    Sensory analysis is an important standard for evaluating food products. However, as trained panelists and time are required for the process, the potential of using fluorescence fingerprint as a rapid instrumental method to approximate sensory characteristics was explored in this study. Thirty-five out of 44 descriptive sensory attributes were found to show a significant difference between samples (analysis of variance test). Principal component analysis revealed that principal component 1 could capture 73.84 and 75.28% variance for aroma category and combined flavor and taste category respectively. Fluorescence fingerprints of tomato juices consisted of two visible peaks at excitation/emission wavelengths of 290/350 and 315/425 nm and a long narrow emission peak at 680 nm. The 680 nm peak was only clearly observed in juices obtained from tomatoes cultivated to be eaten raw. The ability to predict overall sensory profiles was investigated by using principal component 1 as a regression target. Fluorescence fingerprint could predict principal component 1 of both aroma and combined flavor and taste with a coefficient of determination above 0.8. The results obtained in this study indicate the potential of using fluorescence fingerprint as an instrumental method for assessing sensory characteristics of tomato juices. © 2015 Society of Chemical Industry.

  3. Base pairing enhances fluorescence and favors cyclobutane dimer formation induced upon absorption of UVA radiation by DNA.

    Science.gov (United States)

    Banyasz, Akos; Vayá, Ignacio; Changenet-Barret, Pascale; Gustavsson, Thomas; Douki, Thierry; Markovitsi, Dimitra

    2011-04-13

    The photochemical properties of the DNA duplex (dA)(20)·(dT)(20) are compared with those of the parent single strands. It is shown that base pairing increases the probability of absorbing UVA photons, probably due to the formation of charge-transfer states. UVA excitation induces fluorescence peaking at ∼420 nm and decaying on the nanosecond time scale. The fluorescence quantum yield, the fluorescence lifetime, and the quantum yield for cyclobutane dimer formation increase upon base pairing. Such behavior contrasts with that of the UVC-induced processes.

  4. Fluorescent sensors based on bacterial fusion proteins

    Science.gov (United States)

    Prats Mateu, Batirtze; Kainz, Birgit; Pum, Dietmar; Sleytr, Uwe B.; Toca-Herrera, José L.

    2014-06-01

    Fluorescence proteins are widely used as markers for biomedical and technological purposes. Therefore, the aim of this project was to create a fluorescent sensor, based in the green and cyan fluorescent protein, using bacterial S-layers proteins as scaffold for the fluorescent tag. We report the cloning, expression and purification of three S-layer fluorescent proteins: SgsE-EGFP, SgsE-ECFP and SgsE-13aa-ECFP, this last containing a 13-amino acid rigid linker. The pH dependence of the fluorescence intensity of the S-layer fusion proteins, monitored by fluorescence spectroscopy, showed that the ECFP tag was more stable than EGFP. Furthermore, the fluorescent fusion proteins were reassembled on silica particles modified with cationic and anionic polyelectrolytes. Zeta potential measurements confirmed the particle coatings and indicated their colloidal stability. Flow cytometry and fluorescence microscopy showed that the fluorescence of the fusion proteins was pH dependent and sensitive to the underlying polyelectrolyte coating. This might suggest that the fluorescent tag is not completely exposed to the bulk media as an independent moiety. Finally, it was found out that viscosity enhanced the fluorescence intensity of the three fluorescent S-layer proteins.

  5. Peak Bone Mass Measurement in Iranian Healthy Population

    Directory of Open Access Journals (Sweden)

    B Larijani

    2007-08-01

    Full Text Available Background: Osteoporosis is a disabling disease characterized by compromised bone strength, which predisposes a patient to increased risk of fracture. The aim of this study was evaluation the pattern of bone mass in Iranian healthy population. Methods: The study was performed between December 2000 and May 2001 on one thousand three healthy Iranian sub¬jects who currently live in Tehran. They were selected randomly by cluster random sampling among men and women of 10-76 yr from 50 clusters. The volunteer people were referred to the Bone Mineral Density BMD unit of EMRC. The partici¬pants were recalled for three times and the response rate was 83%. BMD was measured by DXA using Lunar DPX-MD device. Results: Females achieved maximum lumbar BMD up to 25-35. Femur BMD maximized in 30 to 35 and after 45 the inten¬sity of bone loss increased. Female peak bone mass in lumbar region was 1.19 ± 0.12 g/cm2and in femur was 1.02±0.12 g/cm2. Male peak bone mass in lumbar region occurred between ages 25-40 yr, Male's femur BMD maximized in 20-30. In male peak lumbar bone mass was 1.22±0.16 g/cm2 and femur was 1.08±0.15 g/cm2. Osteopenia was recog¬nized in 50% and 48.8% of women above 50 in spine and total femur, respectively, however these percentages were 37.1% and 34.8% among male subjects. Conclusion: Iranian BMD values sufficiently different from other countries to warrant a separate reference sample with which to compare individuals for the purpose of diagnosing osteoporosis and osteopenia according to the WHO criteria.

  6. Specific Intensity for Peaking: Is Race Pace the Best Option?

    Directory of Open Access Journals (Sweden)

    Munoz

    2015-09-01

    Full Text Available Background The peaking period for endurance competition is characterized for a relative increase of the intensity of training, after a longer period of training relatively dominated by lower intensity and higher volume Objectives The present study was designed to compare physiological and 10 km performance effects of high intensity training (HIT versus race pace interval training (RP during peaking for competition in well-trained runners. Patients and Methods 13 athletes took part in the study, they were divided into two groups: HIT and RP. HIT performed short intervals at ~105% of the maximal aerobic velocity (MAV, while RP trained longer intervals at a speed of ~90% of the MAV (a speed approximating 10 km race pace. After 12 weeks of baseline training, the athletes trained for 6 weeks under one of the two peaking regimes. Subjects performed 10 km prior to and after the intervention period. The total load of training was matched between groups during the treatment phase. Subjects completed a graded treadmill running test until volitional exhaustion prior to each 10 km race. MAV was determined as the minimal velocity eliciting maximal oxygen consumption (VO2max. Results Both groups significantly improved their 10 km time (35 minutes 29 seconds ± 1 minutes 41 seconds vs 34 minutes 53 seconds ± 1 minutes 55 seconds, P 0.05. In contrast, running economy decreased significantly after HIT (210 ± 6 ml.Kg-1.km-1 vs 218 ± 9, P < 0.05. Conclusions A 6 week period of training at either 105% of MAV or 90% of MAV yielded similar performance gains in a 10km race performed at ~90% MAV. Therefore, the physiological impact of HIT training seems to be positive for VO2max but negative for running economy.

  7. Adjustment of Peak Streamflows of a Tropical River for Urbanization

    Directory of Open Access Journals (Sweden)

    Ata Amini

    2009-01-01

    Full Text Available Peak runoff from a catchment is influenced by many factors such as intensity and duration of rainfall, catchment topography, catchment shape, land use and other variables. For a particular catchment, landuse change and other human activities will alter the characteristic of catchment hydrograph. Problem statement: As a result of urbanization, the magnitude of floods occurring in a catchment increased. It was found that the land use change in the Langat River catchment has clear impact on annual peak streamflow record, particularly from 1983-2003 while, the change has no significant impact on streamflow record from 1960-1982. Spatial data confirms the heavy development occurred in river basin from 1983-2003. Thus, urbanization makes the historical record of Langat River non-homogenous and this makes the mathematical simulation for the record inappropriate due to poor expected output. Approach: In this study, historical record of Langat River, Selangor, Malaysia from 1960-2003 was used to study the impact of urbanization on the streamflow. The annual peak streamflow was selected for this purpose. The peak streamflow record was divided into two sets. Set one from 1960-1982 and set two from 1983-2003, which represent periods before and after urbanization, respectively. To adjust the set one data for urbanization, different adjustment factors were used to make the data homogeneous. Normal model was applied to find the best factor for model fitness. Results: The best adjustment factors were selected by trial and error technique based on 95% confidence level. To determine the optimum adjustment factors from the best ones, the point of intersection between the homogeneity and Normal model evaluation curves was located. This point represented the optimum adjustment factor and its value was found to be 1.9. Autorun model was used to validate the above finding and it was found that the model prediction is acceptable with reasonable accuracy. Conclusion

  8. Numerical simulation of meteorological conditions for peak pollution in Paris

    Energy Technology Data Exchange (ETDEWEB)

    Carissimo, B. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1997-06-01

    Results obtained on the simulation of meteorological conditions during two episodes of peak pollution in Paris are presented, one in the winter, the other in the summer. The A3UR air quality modelling system is first described followed by the MERCURE mesoscale meteorological model. The conditions of simulation are described. The results obtained on these two causes show satisfactory agreement, for example on the magnitude of the urban heat island which is correctly reproduced. In this study, several areas of progress have been identified: improvement of the altitude measurement network around cities, the simulation of light wind conditions and the simulation of formation and dissipation of fog. (author) 24 refs.

  9. Peaked and Smooth Solitons for K*(4,1 Equation

    Directory of Open Access Journals (Sweden)

    Yongan Xie

    2013-01-01

    Full Text Available This paper is contributed to explore all possible single peak solutions for the K*(4,1 equation ut=uxu2+2α(uuxxx+2uxuxx. Our procedure shows that the K*(4,1 equation either has peakon, cuspon, and smooth soliton solutions when sitting on a nonzero constant pedestal limξ→±∞u=A≠0 or possesses compacton solutions only when limξ→±∞u=A=0. We present a new smooth soliton solution in an explicit form. Mathematical analysis and numeric graphs are provided for those soliton solutions of the K*(4,1 equation.

  10. Gamma ray energy spectra to test the peak analysis

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Jong In; Song, Myeong Han; Yun, Ju Yong [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Jee Yon; Row, Jung Whan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2009-09-15

    Gamma ray energy spectra for testing of the spectrum analysis method were produced by using a HPGe detector system. Standard mixed sources emitting gamma ray were used for the purpose. The Monte Carlo Simulation method was utilized for the optimization of measurement condition for radioisotopes in the sources with cascade coincidence summing effects. Calibration spectrum and test spectrum including gamma ray energy peaks with various characteristics were created. The set of test spectra was independently analyzed by 28 spectrometrists in different analysis centers. The reasonability of the spectra was estimated by standard deviations of the intercomparison results of the radioactivity analysis of radioisotopes in the test spectrum.

  11. Peak intensity measurement of relativistic lasers via nonlinear Thomson scattering

    CERN Document Server

    Har-Shemesh, Omri

    2011-01-01

    The measurement of peak laser intensities exceeding $10^{20}\\;\\text{W/cm$^2$}$ is in general a very challenging task. We suggest a simple method to accurately measure such high intensities up to about $10^{23}\\,\\text{W/cm$^2$}$, by colliding a beam of ultrarelativistic electrons with the laser pulse. The method exploits the specific features of the angular distribution of the radiation emitted by ultrarelativistic electrons via nonlinear Thomson scattering. Initial electron energies well within the reach of laser wake-field accelerators are required, allowing in principle for an all-optical setup. Accuracies of the order of 10% are envisaged.

  12. Nonlinear generalization of Den Hartog's equal-peak method

    Science.gov (United States)

    Habib, G.; Detroux, T.; Viguié, R.; Kerschen, G.

    2015-02-01

    This study addresses the mitigation of a nonlinear resonance of a mechanical system. In view of the narrow bandwidth of the classical linear tuned vibration absorber, a nonlinear absorber, termed the nonlinear tuned vibration absorber (NLTVA), is introduced in this paper. An unconventional aspect of the NLTVA is that the mathematical form of its restoring force is tailored according to the nonlinear restoring force of the primary system. The NLTVA parameters are then determined using a nonlinear generalization of Den Hartog's equal-peak method. The mitigation of the resonant vibrations of a Duffing oscillator is considered to illustrate the proposed developments.

  13. Quasispecies theory for multiple-peak fitness landscapes

    Science.gov (United States)

    Munoz, Enrique; Saakian, David; Hu, Chin-Kun; Deem, Michael

    2007-03-01

    We used a path integral representation to solve the Eigen and Crow-Kimura molecular evolution models for the case of multiple fitness peaks with arbitrary fitness and degradation functions. In the general case, we find that the solution to these molecular evolution models can be written as the optimum of a fitness function, with constraints enforced by Lagrange multipliers and with a term accounting for the entropy of the spreading population in sequence space. The results for the Eigen model are applied to consider virus or cancer proliferation under the control of drugs or the immune system.

  14. Peak into the Past - An Archaeo-Astronomy Summer School

    OpenAIRE

    Brown, Daniel Stephen; Neale, N; Francis, R.

    2010-01-01

    Description:\\ud The delivery and impact of an archaeo-astronomy summer school for year 5-8 pupils,utilising local Peak District National Park monuments as an outdoor classroom.\\ud \\ud Abstract:\\ud Our landscape has been shaped by man throughout the millennia. It still contains many clues to how it was used in the past giving us insights into ancient cultures and their everyday life. Our summer school uses archaeology and astronomy as a focus for effective out-of-classroom learning experiences...

  15. Double passing the Kitt Peak 1-m Fourier transform spectrometer

    Science.gov (United States)

    Jennings, D. E.; Hubbard, R.; Brault, J. W.

    1985-01-01

    Attention is given to a simple technique for performing the conversion of the Kitt Peak 1-m Fourier transform spectrometer's dual input/output optical configuration to a double pass configuration that improves spectral resolution by a factor of 2. The modification is made by placing a flat mirror in the output beam from each cat's eye, retroreflecting the beams back through the cat's eyes to the first beam splitter. A single detector is placed at the second input port, which then becomes the instrument's output.

  16. Ultrafast, ultrahigh-peak power Ti:sapphire laser system

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, Koichi; Aoyama, Makoto; Matsuoka, Shinichi; Akahane, Yutaka; Kase, Teiji; Nakano, Fumihiko; Sagisaka, Akito [Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Inst., Kizu, Kyoto (Japan)

    2001-01-01

    We review progress in the generation of multiterawatt optical pulses in the 10-fs range. We describe a design, performance and characterization of a Ti:sapphire laser system based on chirped-pulse amplification, which has produced a peak power in excess of 100-TW with sub-20-fs pulse durations and an average power of 19-W at a 10-Hz repetition rate. We also discuss extension of this system to the petawatt power level and potential applications in the relativistic, ultrahigh intensity regimes. (author)

  17. A New Model of Peaks over Threshold for Multivariate Extremes

    Institute of Scientific and Technical Information of China (English)

    罗耀; 朱良生

    2014-01-01

    The peaks over threshold (POT) methods are used for the univariate and multivariate extreme value analyses of the wave and wind records collected from a hydrometric station in the South China Sea. A new multivariate POT method:Multivariate GPD (MGPD) model is proposed, which can be built easily according to developed parametric models and is a natural distribution of multivariate POT methods. A joint threshold selection approach is used in the MGPD model well. Finally, sensitivity analyses are carried out to calculate the return values of the base shear, and two declustering schemes are compared in this study.

  18. Applications of timing theories to a peak procedure.

    Science.gov (United States)

    Yi, Linlin

    2007-06-01

    This article describes applications of scalar expectancy theory (SET), learning-to-time theory (LeT), and Packet theory to data from a peak procedure. Twelve rats were trained in a multiple cued-interval procedure with two fixed intervals (60 and 120 s) signaled by houselight and white noise. Twenty-five percent of the cycles were nonfood cycles, which were 360 s long and had no reinforcement. Mean and individual response rates on nonfood cycles were fitted with explicit solutions of SET, LeT and Packet theory. Applications of the three timing theories were compared in terms of goodness of fit and complexity.

  19. Reducing Electricity Demand Peaks by Scheduling Home Appliances Usage

    DEFF Research Database (Denmark)

    Rossello Busquet, Ana; Kardaras, Georgios; Iversen, Villy Bæk

    2011-01-01

    (RFS) algorithm, which was originally developed for telecommunication networks, is applied. The purpose is to analyze how a power consumption limit and priorities for home appliances will affect the demand peak and the users’ everyday life. Verification of the effectiveness of the RFS algorithm is done....... Moreover, users can be granted lower electricity bill rates for accepting delaying the operation of some of their appliances. In order to analyze this scenario, teletraffic engineering theory, which is used in evaluating the performance of telecommunication networks, is used. A reversible fair scheduling...

  20. Modelling and Analysis of High Pressure Peaking Switch

    Science.gov (United States)

    S, Bindu; Parekh, Mrunal; Mangalvedekar, H. A.; Sharma, Archana; Chakravarthy, D. P.

    2012-07-01

    This paper presents modelling and analysis of peaking switch used in Marx generator, such that the rise time of the pulse produced by the Marx generator is reduced substantially. Towards this FEMM (Finite Element Methods Magnetics) software is used for the field modelling of the switch and MATLAB for circuit modelling to observe the rise time. The switch has to produce pulse with sub-nanosecond rise time, hence the electrode distance has to be minimum. This switch can withstand high voltage only under high pressure. A mathematical model is simulated in MATLAB to see the performance under high pressure.