WorldWideScience

Sample records for polarization-controlled ir pump-probe

  1. Invited Review Article: Pump-probe microscopy

    International Nuclear Information System (INIS)

    Fischer, Martin C.; Wilson, Jesse W.; Robles, Francisco E.; Warren, Warren S.

    2016-01-01

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.

  2. Invited Review Article: Pump-probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Martin C., E-mail: Martin.Fischer@duke.edu; Wilson, Jesse W.; Robles, Francisco E. [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Warren, Warren S. [Departments of Chemistry, Biomedical Engineering, Physics, and Radiology, Duke University, Durham, North Carolina 27708 (United States)

    2016-03-15

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.

  3. Invited Review Article: Pump-probe microscopy

    Science.gov (United States)

    Fischer, Martin C.; Wilson, Jesse W.; Robles, Francisco E.; Warren, Warren S.

    2016-03-01

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.

  4. Invited Review Article: Pump-probe microscopy

    Science.gov (United States)

    Wilson, Jesse W.; Robles, Francisco E.; Warren, Warren S.

    2016-01-01

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications. PMID:27036751

  5. Femtosecond pump-probe studies of zinc phthalocynine in DMSO

    CSIR Research Space (South Africa)

    Ombinda-Lemboumba, Saturnin

    2010-09-01

    Full Text Available .kashan.co.za] Femtosecond pump-probe studies of zinc phthalocynine in DMSO S OMBINDA-LEMBOUMBA1,2, A DU PLESSIS1, LR BOTHA1, EG ROHWER2 AND CM STEENKANP2 1CSIR National Laser Centre, PO Box 395, Pretoria, 0001 2Laser Research Institute, Department of Physics, University.... The excited state of the oxygen will lead to the destruction of the tumour. Figure 1: Energy transfer and energy level diagram of zinc phthalocyanine PUMP-PROBE TECHNIQUE Figure 2 indicates the Femtosecond pump-probe technique used to investigate...

  6. Retrieval of spectral and dynamic properties from two-dimensional infrared pump-probe experiments.

    Science.gov (United States)

    Chelli, Riccardo; Volkov, Victor V; Righini, Roberto

    2008-07-15

    We have developed a fitting algorithm able to extract spectral and dynamic properties of a three level oscillator from a two-dimensional infrared spectrum (2D-IR) detected in time resolved nonlinear experiments. Such properties go from the frequencies of the ground-to-first and first-to-second vibrational transitions (and hence anharmonicity) to the frequency-fluctuation correlation function. This last is represented through a general expression that allows one to approach the various strategies of modeling proposed in the literature. The model is based on the Kubo picture of stochastic fluctuations of the transition frequency as a result of perturbations by a fluctuating surrounding. To account for the line-shape broadening due to pump pulse spectral width in double-resonance measurements, we supply the fitting algorithm with the option to perform the convolution of the spectral signal with a Lorentzian function in the pump-frequency dimension. The algorithm is tested here on 2D-IR pump-probe spectra of a Gly-Ala dipeptide recorded at various pump-probe delay times. Speedup benchmarks have been performed on a small Beowulf cluster. The program is written in FORTRAN language for both serial and parallel architectures and is available free of charge to the interested reader. (c) 2008 Wiley Periodicals, Inc.

  7. Pump probe spectroscopy of quasiparticle dynamics in cuprate superconductors

    International Nuclear Information System (INIS)

    Segre, Gino P.

    2001-01-01

    Pump probe spectroscopy is used to examine the picosecond response of a BSCCO thin film, and two YBCO crystals in the near infrared. The role of pump fluence and temperature have been closely examined in an effort to clarify the mechanism by which the quasiparticles rejoin the condensate. BSCCO results suggest that the recombination behavior is consistent with the d-wave density of states in that quasiparticles appear to relax to the nodes immediately before they rejoin the condensate. The first substantial investigation of polarized pump probe response in detwinned YBCO crystals is also reported. Dramatic doping dependent anisotropies along the a and b axes are observed in time and temperature resolved studies. Among many results, we highlight the discovery of an anomalous temperature and time dependence of a- axis response in optimally doped YBCO. We also report on the first observation of the photoinduced response in a magnetic field. We find the amplitude of the response, and in some cases, the dynamics considerably changed with the application of a 6T field. Finally, we speculate on two of the many theoretical directions stimulated by our results. We find that the two-fluid model suggests a mechanism to explain how changes at very low energies are visible to a high-energy probe. Also discussed are basic recombination processes which may play a role in the observed decay

  8. Techniques for Pump-Probe Synchronisation of Fsec Radiation Pulses

    CERN Document Server

    Schlarb, Holger

    2005-01-01

    The increasing interest on the production of ultra-short photon pulses in future generations of Free-Electron Lasers operating in the UV, VUV or X-ray regime demands new techniques to reliably measure and control the arrival time of the FEL-pulses at the experiment. For pump-probe experiments using external optical lasers the desired synchronisation is in the order of tens of femtoseconds, the typical duration of the FEL pulse. Since, the accelerators are large scale facilities of the length of several hundred meters or even kilometers, the problem of synchronisation has to be attacked twofold. First, the RF acceleration sections upstream of the magnetic bunch compressors need to be stabilised in amplitude and phase to high precision. Second, the remain electron beam timing jitter needs to be determined with femtosecond accuracy for off-line analysis. In this talk, several techniques using the electron or the FEL beam to monitor the arrival time are presented, and the proposed layout of the synchronisation sy...

  9. Dual-wavelength pump-probe microscopy analysis of melanin composition

    Science.gov (United States)

    Thompson, Andrew; Robles, Francisco E.; Wilson, Jesse W.; Deb, Sanghamitra; Calderbank, Robert; Warren, Warren S.

    2016-01-01

    Pump-probe microscopy is an emerging technique that provides detailed chemical information of absorbers with sub-micrometer spatial resolution. Recent work has shown that the pump-probe signals from melanin in human skin cancers correlate well with clinical concern, but it has been difficult to infer the molecular origins of these differences. Here we develop a mathematical framework to describe the pump-probe dynamics of melanin in human pigmented tissue samples, which treats the ensemble of individual chromophores that make up melanin as Gaussian absorbers with bandwidth related via Frenkel excitons. Thus, observed signals result from an interplay between the spectral bandwidths of the individual underlying chromophores and spectral proximity of the pump and probe wavelengths. The model is tested using a dual-wavelength pump-probe approach and a novel signal processing method based on gnomonic projections. Results show signals can be described by a single linear transition path with different rates of progress for different individual pump-probe wavelength pairs. Moreover, the combined dual-wavelength data shows a nonlinear transition that supports our mathematical framework and the excitonic model to describe the optical properties of melanin. The novel gnomonic projection analysis can also be an attractive generic tool for analyzing mixing paths in biomolecular and analytical chemistry. PMID:27833147

  10. Time zero determination for FEL pump-probe studies based on ultrafast melting of bismuth

    Directory of Open Access Journals (Sweden)

    S. W. Epp

    2017-09-01

    Full Text Available A common challenge for pump-probe studies of structural dynamics at X-ray free-electron lasers (XFELs is the determination of time zero (T0—the time an optical pulse (e.g., an optical laser arrives coincidently with the probe pulse (e.g., a XFEL pulse at the sample position. In some cases, T0 might be extracted from the structural dynamics of the sample's observed response itself, but generally, an independent robust method is required or would be superior to the inferred determination of T0. In this paper, we present how the structural dynamics in ultrafast melting of bismuth can be exploited for a quickly performed, reliable and accurate determination of T0 with a precision below 20 fs and an overall experimental accuracy of 50 fs to 150 fs (estimated. Our approach is potentially useful and applicable for fixed-target XFEL experiments, such as serial femtosecond crystallography, utilizing an optical pump pulse in the ultraviolet to near infrared spectral range and a pixelated 2D photon detector for recording crystallographic diffraction patterns in transmission geometry. In comparison to many other suitable approaches, our method is fairly independent of the pumping wavelength (UV–IR as well as of the X-ray energy and offers a favorable signal contrast. The technique is exploitable not only for the determination of temporal characteristics of the experiment at the interaction point but also for investigating important conditions affecting experimental control such as spatial overlap and beam spot sizes.

  11. Ultra-Broadband Two-Dimensional Electronic Spectroscopy and Pump-Probe Microscopy of Molecular Systems

    Science.gov (United States)

    Spokoyny, Boris M.

    Ultrafast spectroscopy offers an unprecedented view on the dynamic nature of chemical reactions. From charge transfer in semiconductors to folding and isomerization of proteins, these all important processes can now be monitored and in some instances even controlled on real, physical timescales. One of the biggest challenges of ultrafast science is the incredible energetic complexity of most systems. It is not uncommon to encounter macromolecules or materials with absorption spectra spanning significant portions of the visible spectrum. Monitoring a multitude of electronic and vibrational transitions, all dynamically interacting with each other on femtosecond timescales poses a truly daunting experimental task. The first part of this thesis deals with the development of a novel Two-Dimensional Electronic Spectroscopy (2DES) and its associated, advanced detection methodologies. Owing to its ultra-broadband implementation, this technique enables us to monitor femtosecond chemical dynamics that span the energetic landscape of the entire visible spectrum. In order to demonstrate the utility of our method, we apply it to two laser dye molecules, IR-144 and Cresyl Violet. Variation of photophysical properties on a microscopic scale in either man-made or naturally occurring systems can have profound implications on how we understand their macroscopic properties. Recently, inorganic hybrid perovskites have been tapped as the next generation solar energy harvesting materials. Their remarkable properties include low exciton binding energy, low exciton recombination rates and long carrier diffusion lengths. Nevertheless, considerable variability in device properties made with nearly identical preparation methods has puzzled the community. In the second part of this thesis we use non-linear pump probe microscopy to study the heterogeneous nature of femtosecond carrier dynamics in thin film perovskites. We show that the local morphology of the perovskite thin films has a

  12. High Speed Pump-Probe Apparatus for Observation of Transitional Effects in Ultrafast Laser Micromachining Processes

    Directory of Open Access Journals (Sweden)

    Ilya Alexeev

    2015-12-01

    Full Text Available A pump-probe experimental approach has been shown to be a very efficient tool for the observation and analysis of various laser matter interaction effects. In those setups, synchronized laser pulses are used to create an event (pump and to simultaneously observe it (probe. In general, the physical effects that can be investigated with such an apparatus are restricted by the temporal resolution of the probe pulse and the observation window. The latter can be greatly extended by adjusting the pump-probe time delay under the assumption that the interaction process remains fairly reproducible. Unfortunately, this assumption becomes invalid in the case of high-repetition-rate ultrafast laser material processing, where the irradiation history strongly affects the ongoing interaction process. In this contribution, the authors present an extension of the pump-probe setup that allows to investigate transitional and dynamic effects present during ultrafast laser machining performed at high pulse repetition frequencies.

  13. Comparison of pump-probe and hyperspectral imaging in unstained histology sections of pigmented lesions.

    Science.gov (United States)

    Wilson, Jesse W; Robles, Francisco E; Deb, Sanghamitra; Warren, Warren S; Fischer, Martin C

    2017-08-01

    Microscopic variations in melanin composition can be mapped through linear and nonlinear optical responses. Though instrumentation to measure linear attenuation is simple and inexpensive, the nonlinear response provides more degrees of freedom with which to spectroscopically resolve pigments. The objective of this study is to assess differences in imaging melanin contrast by comparing hyperspectral (linear) versus pump-probe (nonlinear) microscopy of unstained histology sections of pigmented lesions. The images and analysis we have presented here show that pump-probe uncovers a greater variation in pigment composition, compared with hyperspectral microscopy, and that the two methods yield complimentary biochemical information.

  14. Short-time solvation dynamics probed by phase-locked heterodyne detected pump-probe

    NARCIS (Netherlands)

    de Boeij, W.P.; Pshenichnikov, M.S; Wiersma, D. A.

    1995-01-01

    Phase-locked heterodyne detected pump-probe experiments are reported on solutions of a dye molecule in ethylene glycol, methanol and acetonitrile. By performing experiments at different phase-lock wavelengths, the real and imaginary parts of the line broadening function g(t) could be mapped out. The

  15. Spatiotemporal dynamics of Raman coherence in hollow-core fibers for a pump-probe setup

    Science.gov (United States)

    Husakou, Anton; Wang, Ying-Ying; Alharbi, Meshaal; Benabid, Fetah

    2018-02-01

    We present an experimental and theoretical study of the stimulated Raman emission in hollow-core kagome waveguides in a pump-probe arrangement. We perform an experimental investigation of the power of the Stokes signal from the probe, which is below the stimulated Raman scattering threshold, as a function the pump-probe delay time. The results show the Stokes power to increase with pump-probe delay, reaching a maximum at 10 ns, and to decrease afterward. In view of a coherence decay time of only 0.25 ns, we demonstrate a surprisingly slow reduction of Stokes signal with the characteristic time much longer than the coherence decay time by a factor of up to 40. The numerical investigations explain the observed phenomenon as a result of the spatiotemporal dynamics of the probe pulse and Raman coherence. We show that the increase of the characteristic time can be related to the spatial position of the intense sideband generation event and its dependence on the pump-probe delay.

  16. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  17. Dynamic characterization of silicon nanowires using a terahertz optical asymmetric demultiplexer-based pump-probe scheme

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.; Dailey, J. M.

    2012-01-01

    Dynamic phase and amplitude all-optical responses of silicon nanowires are characterized using a terahertz optical asymmetric demultiplexer (TOAD) based pump-probe scheme. Ultra-fast recovery is observed for moderate pump powers....

  18. Diagnosis and staging of female genital tract melanocytic lesions using pump-probe microscopy (Conference Presentation)

    Science.gov (United States)

    Robles, Francisco E.; Selim, Maria A.; Warren, Warren S.

    2016-02-01

    Melanoma of the vulva is the second most common type of malignancy afflicting that organ. This disease caries poor prognosis, and shows tendencies to recur locally and develop distant metastases through hematogenous dissemination. Further, there exists significant clinical overlap between early-stage melanomas and melanotic macules, benign lesions that are believed to develop in about 10% of the general female population. In this work we apply a novel nonlinear optical method, pump-probe microscopy, to quantitatively analyze female genitalia tract melanocytic lesions. Pump-probe microscopy provides chemical information of endogenous pigments by probing their electronic excited state dynamics, with subcellular resolution. Using unstained biopsy sections from 31 patients, we find significant differences between melanin type and structure in tissue regions with invasive melanoma, melanoma in-situ and non-malignant melanocytic proliferations (e.g., nevi, melanocytic macules). The molecular images of non-malignant lesion have a well-organized structure, with relatively homogenous pigment chemistry, most often consistent with that of eumelanin with large aggregate size or void of metals, such as iron. On the other hand, pigment type and structure observed in melanomas in-situ and invasive melanomas is typically much more heterogeneous, with larger contributions from pheomelanin, melanins with larger metal content, and/or melanins with smaller aggregate size. Of most significance, clear differences can be observed between melanocytic macules and vulvar melanoma in-situ, which, as discussed above, can be difficult to clinically distinguish. This initial study demonstrates pump-probe microscopy's potential as an adjuvant diagnostic tool by revealing systematic chemical and morphological differences in melanin pigmentation among invasive melanoma, melanoma in-situ and non-malignant melanocytic lesions.

  19. Ultrafast pump-probe spectroscopy in gallium arsenide at 25 T.

    Science.gov (United States)

    Curtis, Jeremy A; Tokumoto, Takahisa; Nolan, Nicholas K; McClintock, Luke M; Cherian, Judy G; McGill, Stephen A; Hilton, David J

    2014-10-01

    We have performed high-fluence, nondegenerate pump-probe spectroscopy in the Split Florida-Helix magnet at 25 T and 15 K. The electronic component of our ultrafast differential reflectivity can be described with a simplified four-level approximation to determine the scattering and recombination rates. Ultrafast oscillations are well described by a coherent acoustic phonon model. Our free-space ultrafast spectroscopic technique will permit future experimental investigations to study novel photoinduced phase transitions and complex interactions in correlated electron systems, which will require the high pulse energies of our free-space alternative.

  20. Anomalous phase behavior and apparent anharmonicity of the pump-probe signal in a two-dimensional harmonic potential system

    International Nuclear Information System (INIS)

    Taneichi, T.; Kobayashi, T.

    2007-01-01

    Discussion on wavelength dependent 'anharmonic' effects in a pump-probe signal for a system of wavepacket on one- and two-dimensional harmonic potentials was given. The Fourier power spectrum of the signal, calculated for a model composed of a three-state electronic system coupled to a set of displaced harmonic oscillators, depends on the pulse duration. Condition under which the wavepacket motion in the harmonic potential substantially deviates from that of the classical point mass is derived. The Fourier power spectrum has enhanced components with frequencies of harmonics even in a system composed of ideally harmonic potentials. Utility of the Fourier analysis of the spectrum for clarification of the squeezed molecular vibrational state is discussed. Calculated oscillatory behavior in phase of a pump-probe signal, as a function of probe frequency, was discussed in terms of a two-dimensional effect on a pump-probe signal

  1. Generation of stable sub-10 fs pulses at 400 nm in a hollow fiber for UV pump-probe experiment.

    Science.gov (United States)

    Liu, Jun; Kida, Yuichiro; Teramoto, Takahiro; Kobayashi, Takayoshi

    2010-03-01

    Stable sub-10-fs pulses useful for many pump-probe experiments with center wavelength at 400 nm were obtained using a hollow-fiber compression technique with a beam-pointing stabilizing system. The output power stability was improved by around 2-times with the beam-pointing stabilizer. A 1-mm-thick cell sample of perylene dissolved in cyclohexane was used to test the pulse using for the pump-probe experiment. Even the high C-H stretching of vibration mode at around 2860 cm(-1), 2916 cm(-1), and 2955 cm(-1) were real-time resolved with vibrational phase information.

  2. A two-parameter nondiffusive heat conduction model for data analysis in pump-probe experiments

    Science.gov (United States)

    Ma, Yanbao

    2014-12-01

    Nondiffusive heat transfer has attracted intensive research interests in last 50 years because of its importance in fundamental physics and engineering applications. It has unique features that cannot be described by the Fourier law. However, current studies of nondiffusive heat transfer still focus on studying the effective thermal conductivity within the framework of the Fourier law due to a lack of a well-accepted replacement. Here, we show that nondiffusive heat conduction can be characterized by two inherent material properties: a diffusive thermal conductivity and a ballistic transport length. We also present a two-parameter heat conduction model and demonstrate its validity in different pump-probe experiments. This model not only offers new insights of nondiffusive heat conduction but also opens up new avenues for the studies of nondiffusive heat transfer outside the framework of the Fourier law.

  3. Near shot-noise limited time-resolved circular dichroism pump-probe spectrometer

    Science.gov (United States)

    Stadnytskyi, Valentyn; Orf, Gregory S.; Blankenship, Robert E.; Savikhin, Sergei

    2018-03-01

    We describe an optical near shot-noise limited time-resolved circular dichroism (TRCD) pump-probe spectrometer capable of reliably measuring circular dichroism signals in the order of μdeg with nanosecond time resolution. Such sensitivity is achieved through a modification of existing TRCD designs and introduction of a new data processing protocol that eliminates approximations that have caused substantial nonlinearities in past measurements and allows the measurement of absorption and circular dichroism transients simultaneously with a single pump pulse. The exceptional signal-to-noise ratio of the described setup makes the TRCD technique applicable to a large range of non-biological and biological systems. The spectrometer was used to record, for the first time, weak TRCD kinetics associated with the triplet state energy transfer in the photosynthetic Fenna-Matthews-Olson antenna pigment-protein complex.

  4. Energy transfer in isolated LHC II studied by femtosecond pump-probe technique

    CERN Document Server

    Yang Yi; Liu Yuan; Liu Wei Min; Zhu Rong Yi; Qian Shi Xiong; Xu Chun He

    2003-01-01

    Excitation energy transfer in the isolated light-harvesting chlorophyll (Chl)-a/b protein complex of photosystem II (LHC II) was studied by the one-colour pump-probe technique with femtosecond time resolution. After exciting Chl-b by 638nm beam, the dynamic behaviour shows that the ultrafast energy transfer from Chl-b at positions of B2, B3, and B5 to the corresponding Chl-a molecules in monomeric subunit of LHC II is in the time scale of 230fs. While with the excitation of Chl-a at 678nm, the energy transfer between excitons of Chl-a molecules has the lifetime of about 370 fs, and two other slow decay components are due to the energy transfer between different Chl-a molecules in a monomeric subunit of LHC II or in different subunits, or due to change of molecular conformation. (20 refs).

  5. Frequency-domain modelling of gain in pump-probe experiment by an inhomogeneous medium

    Science.gov (United States)

    Kim, Minkyung; Oh, Sang Soon; Hess, Ortwin; Rho, Junsuk

    2018-02-01

    Introduction of a gain medium in lossy plasmonic metamaterials reduces and compensates losses or even amplifies an incident light often with nonlinear optical effect. Here, optical gain in a pump-probe experimental setup is effectively calculated in the frequency-domain by approximating a gain material as an inhomogeneous medium. Spatially varying local field amplitudes of the pump and probe beams are included in the model to reproduce the inhomogeneous gain effect, in which population inversion occurs most strongly near the surface and decays along the propagation direction. We demonstrate that transmission spectra calculated by this method agree well with finite-difference time-domain simulation results. This simplified approach of gain modelling offers an easy and reliable way to analyze wave propagation in a gain medium without nonlinear time-domain calculation.

  6. Time resolved EUV pump-probe microscopy of fs-LASER induced nanostructure formation

    Science.gov (United States)

    Freiberger, R.; Hauck, J.; Reininghaus, M.; Wortmann, D.; Juschkin, L.

    2011-05-01

    We report on our efforts in design and construction of a compact Extreme Ultraviolet (EUV)-pump-probe microscope. The goal is the observation of formation of nanostructures, induced by a femtosecond (fs)-laser pulse. The unique interaction processes of fs-laser radiation with matter open up new markets in laser material processing and, therefore, are actively investigated in the last decade. The resulting "sub 100 nm"-structures offer vast potential benefits in photonics, biotechnology, tribological surface design, plasmonic applications and production of nanoparticles. Focused fs-laser radiation causes a local modification resulting in nanostructures of high precision and reproducibility. However the formation dynamics is not well understood. Research in this field requires high temporal and spatial resolution. A combination of fs-laser and EUV-microscope provides a tool for "in situ"-observation of the formation dynamics. As exemplary structures to be investigated, we use nanojets on thin gold films and periodic surface structures (ripples) on dielectrics. In the future, the EUV-pump-probe microscope can become a versatile tool to observe physical or biological processes. Microscopy using EUV-light is capable of detecting structures on a scale down to several tens of nanometers. For detailed investigations a compact EUV-microscope has been realized utilizing OVI Balmer-alpha radiation at 17.3 nm coming from a discharge produced oxygen plasma. As optical elements a grazing incidence elliptical collector and a zone plate with a width of outermost zone of 50 nm and a spectral filter to avoid chromatic aberrations are used. The detector is a fast gated microchannel plate with a pore size of 2 microns contacted by a low impedance transmission line. The expected spatial resolution of the setup is better than 100 nm and the time resolution is better than 1 ns. The newly developed EUV-microscope is a powerful tool for a wide field of investigations that need high time

  7. Resolution enhancement of pump-probe microscope with an inverse-annular filter

    Science.gov (United States)

    Kobayashi, Takayoshi; Kawasumi, Koshi; Miyazaki, Jun; Nakata, Kazuaki

    2018-03-01

    Optical pump-probe microscopy can provide images by detecting changes in probe light intensity induced by stimulated emission, photoinduced absorbance change, or photothermal-induced refractive index change in either transmission or reflection mode. Photothermal microscopy, which is one type of optical pump-probe microscopy, has intrinsically super resolution capability due to the bilinear dependence of signal intensity of pump and probe. We introduce new techniques for further resolution enhancement and fast imaging in photothermal microscope. First, we introduce a new pupil filter, an inverse-annular pupil filter in a pump-probe photothermal microscope, which provides resolution enhancement in three dimensions. The resolutions are proved to be improved in lateral and axial directions by imaging experiment using 20-nm gold nanoparticles. The improvement in X (perpendicular to the common pump and probe polarization direction), Y (parallel to the polarization direction), and Z (axial direction) are by 15 ± 6, 8 ± 8, and 21 ± 2% from the resolution without a pupil filter. The resolution enhancement is even better than the calculation using vector field, which predicts the corresponding enhancement of 11, 8, and 6%. The discussion is made to explain the unexpected results. We also demonstrate the photothermal imaging of thick biological samples (cells from rabbit intestine and kidney) stained with hematoxylin and eosin dye with the inverse-annular filter. Second, a fast, high-sensitivity photothermal microscope is developed by implementing a spatially segmented balanced detection scheme into a laser scanning microscope using a Galvano mirror. We confirm a 4.9 times improvement in signal-to-noise ratio in the spatially segmented balanced detection compared with that of conventional detection. The system demonstrates simultaneous bi-modal photothermal and confocal fluorescence imaging of transgenic mouse brain tissue with a pixel dwell time of 20 µs. The

  8. Resolution enhancement of pump-probe microscope with an inverse-annular filter

    Science.gov (United States)

    Kobayashi, Takayoshi; Kawasumi, Koshi; Miyazaki, Jun; Nakata, Kazuaki

    2018-04-01

    Optical pump-probe microscopy can provide images by detecting changes in probe light intensity induced by stimulated emission, photoinduced absorbance change, or photothermal-induced refractive index change in either transmission or reflection mode. Photothermal microscopy, which is one type of optical pump-probe microscopy, has intrinsically super resolution capability due to the bilinear dependence of signal intensity of pump and probe. We introduce new techniques for further resolution enhancement and fast imaging in photothermal microscope. First, we introduce a new pupil filter, an inverse-annular pupil filter in a pump-probe photothermal microscope, which provides resolution enhancement in three dimensions. The resolutions are proved to be improved in lateral and axial directions by imaging experiment using 20-nm gold nanoparticles. The improvement in X (perpendicular to the common pump and probe polarization direction), Y (parallel to the polarization direction), and Z (axial direction) are by 15 ± 6, 8 ± 8, and 21 ± 2% from the resolution without a pupil filter. The resolution enhancement is even better than the calculation using vector field, which predicts the corresponding enhancement of 11, 8, and 6%. The discussion is made to explain the unexpected results. We also demonstrate the photothermal imaging of thick biological samples (cells from rabbit intestine and kidney) stained with hematoxylin and eosin dye with the inverse-annular filter. Second, a fast, high-sensitivity photothermal microscope is developed by implementing a spatially segmented balanced detection scheme into a laser scanning microscope using a Galvano mirror. We confirm a 4.9 times improvement in signal-to-noise ratio in the spatially segmented balanced detection compared with that of conventional detection. The system demonstrates simultaneous bi-modal photothermal and confocal fluorescence imaging of transgenic mouse brain tissue with a pixel dwell time of 20 µs. The

  9. Infrared-x-ray pump-probe spectroscopy of the NO molecule

    International Nuclear Information System (INIS)

    Guimaraes, F.F.; Felicissimo, V.C.; Kimberg, V.; Gel'mukhanov, F.; Aagren, H.; Cesar, A.

    2005-01-01

    Two color infrared-x-ray pump-probe spectroscopy of the NO molecule is studied theoretically and numerically in order to obtain a deeper insight of the underlying physics and of the potential of this suggested technology. From the theoretical investigation a number of conclusions could be drawn: It is found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the x-ray spectrum. The trajectory experiences fast oscillations with the vibrational frequency with a modulation due to the anharmonicity of the potential. The dependences of the x-ray spectra on the delay time, the duration, and the shape of the pulses are studied in detail. It is shown that the x-ray spectrum keep memory about the infrared phase after the pump field left the system. This memory effect is sensitive to the time of switching-off the pump field and the Rabi frequency. The phase effect takes maximum value when the duration of the x-ray pulse is one-fourth of the infrared field period, and can be enhanced by a proper control of the duration and intensity of the pump pulse. The manifestation of the phase is different for oriented and disordered molecules and depends strongly on the intensity of the pump radiation

  10. Investigation of electronically excited indole relaxation dynamics via photoionization and fragmentation pump-probe spectroscopy

    Science.gov (United States)

    Godfrey, T. J.; Yu, Hui; Ullrich, Susanne

    2014-07-01

    The studies herein investigate the involvement of the low-lying 1La and 1Lb states with 1ππ* character and the 1πσ* state in the deactivation process of indole following photoexcitation at 201 nm. Three gas-phase, pump-probe spectroscopic techniques are employed: (1) Time-resolved photoelectron spectroscopy (TR-PES), (2) hydrogen atom (H-atom) time-resolved kinetic energy release (TR-KER), and (3) time-resolved ion yield (TR-IY). Each technique provides complementary information specific to the photophysical processes in the indole molecule. In conjunction, a thorough examination of the electronically excited states in the relaxation process, with particular focus on the involvement of the 1πσ* state, is afforded. Through an extensive analysis of the TR-PES data presented here, it is deduced that the initial excitation of the 1Bb state decays to the 1La state on a timescale beyond the resolution of the current experimental setup. Relaxation proceeds on the 1La state with an ultrafast decay constant (IY experiments, both specifically probing 1πσ* dynamics, exhibit similar decay constants, further validating these observations.

  11. Thirteen pump-probe resonances of the sodium D1 line

    International Nuclear Information System (INIS)

    Wong, Vincent; Boyd, Robert W.; Stroud, C. R. Jr.; Bennink, Ryan S.; Marino, Alberto M.

    2003-01-01

    We present the results of a pump-probe laser spectroscopic investigation of the Doppler-broadened sodium D1 resonance line. We find 13 resonances in the resulting spectra. These observations are well described by the numerical predictions of a four-level atomic model of the hyperfine structure of the sodium D1 line. We also find that many, but not all, of these features can be understood in terms of processes originating in a two-level or three-level subset of the full four-level model. The processes we observed include forward near-degenerate four-wave mixing and saturation in a two-level system, difference-frequency crossing and nondegenerate four-wave mixing in a three-level V system, electromagnetically induced transparency and optical pumping in a three-level lambda system, cross-transition resonance in a four-level double-lambda system, and conventional optical pumping. Most of these processes lead to sub-Doppler or even subnatural linewidths. The dependence of these resonances on the pump intensity and pump detuning from atomic resonance are also studied

  12. Non-degenerate pump-probe spectroscopy of single GaN nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhya, Prashanth C [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory; Prasankumar, Rohiy P [Los Alamos National Laboratory; Wang, George T [SNL; Martinez, Julio A [SNL; Li, Qiming [SNL; Swartzentruber, Brian S [SNL

    2010-01-01

    Spatially-resolved ultrafast transient absorption measurements on a single GaN nanowire give insight into carrier relaxation dynamics as a function of the probe polarization and position on the nanowire on a femtosecond timescale. The synthesis and optical characterization of semiconductor nanowires (NWs) has gained considerable attention in recent years owing to their unique electronic and optical properties that arise from their anisotropic geometry, large surface to volume ratio and two-dimensional quasiparticle confinement, Post-growth characterization of their properties is crucial in understanding the fundamental physical processes that can lead to enhanced functionality of NW-based devices, In particular, it is important to understand the carrier relaxation pathways in individual NWs, since the geometry of these nanostructures can significantly influence carrier recombination and/or trapping. In this respect, ultrafast optical techniques offer reliable and non-contact spectroscopic tools to study carrier dynamics in semiconductor nanostructures. In summary, time-resolved optical pump-probe spectroscopy was performed on single GaN NWs. These measurements give insight into the different processes that govern carrier capture, particularly at surface states, and relaxation in individual nanostructures. Our experiments thus demonstrate the value of single-particle ultrafast optical spectroscopy in understanding the physical processes that govern the properties of semiconductor NWs, while suggesting approaches to optimize NW-based devices for nanophotonic applications.

  13. Femtosecond resolution timing jitter correction on a TW scale Ti:sapphire laser system for FEL pump-probe experiments.

    Science.gov (United States)

    Csatari Divall, Marta; Mutter, Patrick; Divall, Edwin J; Hauri, Christoph P

    2015-11-16

    Intense ultrashort pulse lasers are used for fs resolution pump-probe experiments more and more at large scale facilities, such as free electron lasers (FEL). Measurement of the arrival time of the laser pulses and stabilization to the machine or other sub-systems on the target, is crucial for high time-resolution measurements. In this work we report on a single shot, spectrally resolved, non-collinear cross-correlator with sub-fs resolution. With a feedback applied we keep the output of the TW class Ti:sapphire amplifier chain in time with the seed oscillator to ~3 fs RMS level for several hours. This is well below the typical pulse duration used at FELs and supports fs resolution pump-probe experiments. Short term jitter and long term timing drift measurements are presented. Applicability to other wavelengths and integration into the timing infrastructure of the FEL are also covered to show the full potential of the device.

  14. Polarization controlled UV writing of bragg gratings

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Plougmann, Nikolai; Deyerl, Hans-Jürgen

    2002-01-01

    In conclusion the polarization control method is superior to any double scan method since it allows much more flexible apodization and inclusion of phase shifts, and since only one exposure is required. In many cases the method performs just as well as the most sophisticated phase mask jitter met...

  15. Construction of a magnetic bottle spectrometer and its application to pulse duration measurement of X-ray laser using a pump-probe method

    Directory of Open Access Journals (Sweden)

    S. Namba

    2015-11-01

    Full Text Available To characterize the temporal evolution of ultrashort X-ray pulses emitted by laser plasmas using a pump-probe method, a magnetic bottle time-of-flight electron spectrometer is constructed. The design is determined by numerical calculations of a mirror magnetic field and of the electron trajectory in a flight tube. The performance of the spectrometer is characterized by measuring the electron spectra of xenon atoms irradiated with a laser-driven plasma X-ray pulse. In addition, two-color above-threshold ionization (ATI experiment is conducted for measurement of the X-ray laser pulse duration, in which xenon atoms are simultaneously irradiated with an X-ray laser pump and an IR laser probe. The correlation in the intensity of the sideband spectra of the 4d inner-shell photoelectrons and in the time delay of the two laser pulses yields an X-ray pulse width of 5.7 ps, in good agreement with the value obtained using an X-ray streak camera.

  16. Time-resolved pump-probe X-ray absorption fine structure spectroscopy of Gaq3

    International Nuclear Information System (INIS)

    Dicke, Benjamin

    2013-01-01

    Gallium(tris-8-hydroxyquinoline) (Gaq 3 ) belongs to a class of metal organic compounds, used as electron transport layer and emissive layer in organic light emitting diodes. Many research activities have concentrated on the optical and electronic properties, especially of the homologue molecule aluminum(tris-8-hydroxyquinoline) (Alq 3 ). Knowledge of the first excited state S 1 structure of these molecules could provide deeper insight into the processes involved into the operation of electronic devices, such as OLEDs and, hence, it could further improve their efficiency and optical properties. Until now the excited state structure could not be determined experimentally. Most of the information about this structure mainly arises from theoretical calculations. X-ray absorption fine structure (XAFS) spectroscopy is a well developed technique to determine both, the electronic and the geometric properties of a sample. The connection of ultrashort pulsed X-ray sources with a pulsed laser system offers the possibility to use XAFS as a tool for studying the transient changes of a sample induced by a laser pulse. In the framework of this thesis a new setup for time-resolved pump-probe X-ray absorption spectroscopy at PETRA III beamline P11 was developed for measuring samples in liquid form. In this setup the sample is pumped into its photo-excited state by a femtosecond laser pump pulse with 343 nm wavelength and after a certain time delay probed by an X-ray probe pulse. In this way the first excited singlet state S 1 of Gaq 3 dissolved in benzyl alcohol was analyzed. A structural model for the excited state structure of the Gaq 3 molecule based on the several times reproduced results of the XAFS experiments is proposed. According to this model it was found that the Ga-N A bond length is elongated, while the Ga-O A bond length is shortened upon photoexcitation. The dynamics of the structural changes were not the focus of this thesis. Nevertheless the excited state lifetime

  17. Development of an X-ray delay unit for correlation spectroscopy and pump-probe experiments

    International Nuclear Information System (INIS)

    Roseker, Wojciech

    2008-07-01

    Probing condensed matter on time scales ranging from femtoseconds to nanoseconds will be one of the key topics for future X-ray Free Electron Laser (XFEL) sources. The accessible time windows are, however, compromised by the intrinsic time structure of the sources. One way to overcome this limitation is the usage of a time delay unit. A prototype device capable of splitting an X-ray pulse into two adjustable fractions, delaying one of them with the aim to perform X-ray Photon Correlation Spectroscopy and pump-probe type studies was designed and manufactured. The device utilizes eight perfect crystals in vertical 90 scattering geometry. Its performance has been verified with 8.39 keV and 12.4 keV Xrays at various synchrotron sources. The measured throughput of the device with a Si(333) monochromator at 8.39 keV under ambient conditions is 0.6%. The stability was verified at 12.4 keV and operation without realignment and feedback was possible for more than 30 minutes. Time delays up to 2.95 ns have been achieved. The highest resolution achieved in an experiment was 15.4 ps, a value entirely determined by the diagnostics system. The influence of the delay unit optics on the coherence properties of the beam was investigated by means of Fraunhofer diffraction and static speckle analysis. The obtained high fringe visibility and contrast values larger than 23% indicate the feasibility of performing coherence based experiments with the delay line. (orig.)

  18. Development of an X-ray delay unit for correlation spectroscopy and pump-probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Roseker, Wojciech

    2008-07-15

    Probing condensed matter on time scales ranging from femtoseconds to nanoseconds will be one of the key topics for future X-ray Free Electron Laser (XFEL) sources. The accessible time windows are, however, compromised by the intrinsic time structure of the sources. One way to overcome this limitation is the usage of a time delay unit. A prototype device capable of splitting an X-ray pulse into two adjustable fractions, delaying one of them with the aim to perform X-ray Photon Correlation Spectroscopy and pump-probe type studies was designed and manufactured. The device utilizes eight perfect crystals in vertical 90 scattering geometry. Its performance has been verified with 8.39 keV and 12.4 keV Xrays at various synchrotron sources. The measured throughput of the device with a Si(333) monochromator at 8.39 keV under ambient conditions is 0.6%. The stability was verified at 12.4 keV and operation without realignment and feedback was possible for more than 30 minutes. Time delays up to 2.95 ns have been achieved. The highest resolution achieved in an experiment was 15.4 ps, a value entirely determined by the diagnostics system. The influence of the delay unit optics on the coherence properties of the beam was investigated by means of Fraunhofer diffraction and static speckle analysis. The obtained high fringe visibility and contrast values larger than 23% indicate the feasibility of performing coherence based experiments with the delay line. (orig.)

  19. An electro-optical timing diagnostic for pump-probe experiments at the free-electron laser in Hamburg FLASH

    International Nuclear Information System (INIS)

    Azima, Armin

    2009-07-01

    Femtosecond pump-probe experiments have extensively been used to follow atomic and molecular motion in time. The very intense extreme ultraviolet XUV light of the Free electron LASer in Hamburg FLASH facility allows to investigate fundamental processes such as direct one or few photon inner shell ionizations. A supplementary Ti:Sapphire near infrared femtosecond laser system allows to perform two-color pump-probe experiments with FLASH involving intense laser fields of hugely different photon energies. Within this work a bunch arrival measurement system has been built, which assists these two-color pump-probe experiments to reduce the temporal jitter of FLASH and to increase the temporal resolution. The diagnostic is based upon an electro-optical detection scheme and measures the relative arrival time between the Ti:Sapphire femtosecond pulse and the electron bunch, which generates the self-amplified by stimulated emission SASE XUV pulse in the undulator section of FLASH. Key feature of the diagnostic is a 150 m long glass fiber pulse transport line, which inflicts non-linear dispersion. A dispersion control system to compensate for this higher order dispersion has been developed including the control and programming of a spatial light phase modulator. It was possible to transport a 90 fs FWHM short near infrared femtosecond laser pulse Fourier limited by the dispersion compensated glass fiber. The electro-optical signal induced by the FLASH electron bunch was generated, characterized and optimized. The signal features beside the designated bunch arrival timing capability the additional possibility to measure the longitudinal electron bunch density distribution of an arbitrary bunch of FLASH in a single shot with a temporal resolution of below 100 fs RMS. Timing and bunch analysis capabilities of the developed diagnostic have been cross-checked with other comparable diagnostics at FLASH like the transversal deflecting cavity structure named LOLA. Finally, the

  20. An electro-optical timing diagnostic for pump-probe experiments at the free-electron laser in Hamburg FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Azima, Armin

    2009-07-15

    Femtosecond pump-probe experiments have extensively been used to follow atomic and molecular motion in time. The very intense extreme ultraviolet XUV light of the Free electron LASer in Hamburg FLASH facility allows to investigate fundamental processes such as direct one or few photon inner shell ionizations. A supplementary Ti:Sapphire near infrared femtosecond laser system allows to perform two-color pump-probe experiments with FLASH involving intense laser fields of hugely different photon energies. Within this work a bunch arrival measurement system has been built, which assists these two-color pump-probe experiments to reduce the temporal jitter of FLASH and to increase the temporal resolution. The diagnostic is based upon an electro-optical detection scheme and measures the relative arrival time between the Ti:Sapphire femtosecond pulse and the electron bunch, which generates the self-amplified by stimulated emission SASE XUV pulse in the undulator section of FLASH. Key feature of the diagnostic is a 150 m long glass fiber pulse transport line, which inflicts non-linear dispersion. A dispersion control system to compensate for this higher order dispersion has been developed including the control and programming of a spatial light phase modulator. It was possible to transport a 90 fs FWHM short near infrared femtosecond laser pulse Fourier limited by the dispersion compensated glass fiber. The electro-optical signal induced by the FLASH electron bunch was generated, characterized and optimized. The signal features beside the designated bunch arrival timing capability the additional possibility to measure the longitudinal electron bunch density distribution of an arbitrary bunch of FLASH in a single shot with a temporal resolution of below 100 fs RMS. Timing and bunch analysis capabilities of the developed diagnostic have been cross-checked with other comparable diagnostics at FLASH like the transversal deflecting cavity structure named LOLA. Finally, the

  1. A wavelength dependent investigation of the indole photophysics via ionization and fragmentation pump-probe spectroscopies.

    Science.gov (United States)

    Godfrey, T J; Yu, Hui; Biddle, Michael S; Ullrich, Susanne

    2015-10-14

    A wavelength dependent study investigating the low-lying (1)La and (1)Lb states, both possessing (1)ππ* character, and the (1)πσ* state in the deactivation process of indole is presented here. Relaxation dynamics following excitation at 241, 250, 260, 270, 273, and 282 nm are examined using three gas-phase, pump-probe spectroscopic techniques: (1) hydrogen atom (H-atom) time-resolved kinetic energy release (TR-KER), (2) time-resolved photoelectron spectroscopy (TR-PES), and (3) time-resolved ion yield (TR-IY). Applied in combination, a more complete picture of the indole relaxation dynamics may be gleaned. For instance, TR-PES experiments directly observe all relaxation pathways by probing the evolution of the excited states following photoexcitation; whereas, TR-KER measurements indirectly, yet specifically, probe for (1)πσ*-state activity through the detection of H-atoms eliminated along the indole nitrogen-hydrogen (N-H) stretch coordinate-a possible outcome of (1)πσ*-state relaxation in indole. In addition, mass information obtained via TR-IY monitors fragmentation dynamics that may occur within the neutral electronically excited and/or cationic states. The work herein assesses the onset and importance of the (1)πσ* state at various pump wavelengths by systematically tuning across the ultraviolet absorption spectrum of indole with a particular focus on those pump wavelengths longer than 263 nm, where the involvement of the (1)πσ* state is under current debate. As far as this experimental work is concerned, there does not appear to be any significant involvement by the (1)πσ* state in the indole relaxation processes following excitation at 270, 273, or 282 nm. This investigation also evaluates the primary orbital promotions contributing to the (1)La, (1)Lb, and (1)πσ* transitions based on ionization preferences observed in TR-PES spectra. Relaxation time constants associated with dynamics along these states are also reported for excitation at all

  2. Theoretical Simulations and Ultrafast Pump-probe Spectroscopy Experiments in Pigment-protein Photosynthetic Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Buck, D. R. [Iowa State Univ., Ames, IA (United States)

    2000-09-12

    Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by

  3. Ultrafast pump-probe spectroscopy of Zinc Phthalocynine (ZnPc) and light harvesting complex II (LHC II)

    CSIR Research Space (South Africa)

    Ombinda-Lemboumba, Saturnin

    2009-07-01

    Full Text Available • To develop light harvesting and energy transfer systems having architectures to enable energy transfer. • To characterize these systems with respect to the direction, efficiency and rate of energy transfer from the site of photon absorption... pump-probe spectroscopy of Zinc Phthalocynine (ZnPc) and light harvesting complex II (LHC II) SAIP 7-10 July 2009, University of Kwazulu Natal. S. Ombinda-Lemboumba1, 2 A. du Plessis1, L. Botha1, D.E. Roberts1, P. Molukanele1, 3, R.W. Sparrow3, E...

  4. Quantifying melanin spatial distribution using pump-probe microscopy and a 2-D morphological autocorrelation transformation for melanoma diagnosis

    Science.gov (United States)

    Robles, Francisco E.; Wilson, Jesse W.; Warren, Warren S.

    2013-12-01

    Pump-probe microscopy is an emerging molecular imaging technique that probes the excited state dynamics properties of pigmented samples. This method has been particularly intriguing for melanoma because, unlike other methods available, it can provide nondestructive, quantitative chemical information regarding different types of melanins, with high spatial resolution. In this Letter, we present a method based on mathematical morphology to quantify melanin structure (eumelanin, pheomelanin, and total melanin content, uniquely available with pump-probe microscopy) to aid in melanoma diagnosis. The approach applies a two-dimensional autocorrelation function and utilizes statistical parameters of the corresponding autocorrelation images, specifically, the second moments and entropy, to parameterize image structure. Along with bulk melanin chemical information, we show that this method can differentiate invasive melanomas from noninvasive and benign lesions with high sensitivity and specificity (92.3% and 97.5%, respectively, with N=53). The mathematical method and the statistical analysis are described in detail and results from cutaneous and ocular conjunctival melanocytic lesions are presented.

  5. Basic design of beamline and polarization control

    International Nuclear Information System (INIS)

    Watanabe, M.

    2006-01-01

    The basic concept of synchrotron radiation beamlines for' vacuum ultraviolet and X-ray experiments has been introduced to beginning users and designers of beamlines. The beamline defined here is composed of a front end, pre-mirrors, and a monochromator with refocusing mirrors, which are connected by beam pipes, providing monochromatic light for the experiments. Firstly, time characteristics of the synchrotron radiation are briefly reviewed. Secondly, the basic technology is introduced as the fundamental knowledge required to both users and designers. The topics are photoabsorption by air and solids, front ends and beam pipes, mirrors, monochromators, and filters. Thirdly, the design consideration is described mainly for the designers. The topics are design principle, principle of ray tracing, optical machinery and control, and vacuum. Fourthly, polarization control is considered. The topics are polarizers, polarization diagnosis of beamline, and circularly-polarized light generation. Finally, a brief summary is given introducing some references for further knowledge of the user's and the designers. (authors)

  6. Gauge invariance in the theoretical description of time-resolved angle-resolved pump/probe photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Freericks, J. K.; Krishnamurthy, H. R.; Sentef, M. A.; Devereaux, T. P.

    2015-10-01

    Nonequilibrium calculations in the presence of an electric field are usually performed in a gauge, and need to be transformed to reveal the gauge-invariant observables. In this work, we discuss the issue of gauge invariance in the context of time-resolved angle-resolved pump/probe photoemission. If the probe is applied while the pump is still on, one must ensure that the calculations of the observed photocurrent are gauge invariant. We also discuss the requirement of the photoemission signal to be positive and the relationship of this constraint to gauge invariance. We end by discussing some technical details related to the perturbative derivation of the photoemission spectra, which involve processes where the pump pulse photoexcites electrons due to nonequilibrium effects.

  7. Ultrafast pump-probe reflectance spectroscopy: Why sodium makes Cu(In,Ga)Se2 solar cells better

    KAUST Repository

    Eid, Jessica

    2015-04-14

    Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.

  8. Quantifying melanin distribution using pump-probe microscopy and a 2D morphological autocorrelation transformation for melanoma diagnosis

    Science.gov (United States)

    Robles, Francisco E.; Wilson, Jesse W.; Warren, Warren S.

    2014-03-01

    Pump-probe microscopy is a quantitative molecular imaging technique that yields diagnostically relevant information from endogenous pigments, like melanin, by probing their ultrafast photodynamic properties. Previously, the method was applied to image thin, pigmented, cutaneous samples at different stages of melanoma, and results have shown a correlation between melanin photodynamic behavior and malignancy. Here, we add to the diagnostic power of the method by applying principles of mathematical morphology to parameterize melanins' image structure. Along with bulk melanin chemical information, results show that this method can differentiate invasive melanomas from non-invasive and benign lesions with high sensitivity and specificity (92.3% and 97.5%, respectively, with N = 53). The mathematical method and the statistical analysis are described in detail and results from cutaneous and ocular conjuctival melanocytic lesions are presented.

  9. Light Driven Energy Research at LCLS: Planned Pump-Probe X-ray Spectroscopy Studies on Photosynthetic Water Splitting

    Science.gov (United States)

    Bergmann, Uwe

    2010-02-01

    Arguably the most important chemical reaction on earth is the photosynthetic splitting of water to molecular oxygen by the Mn-containing oxygen-evolving complex (Mn-OEC) in the protein known as photosystem II (PSII). It is this reaction which has, over the course of some 3.8 billion years, gradually filled our atmosphere with O2 and consequently enabled and sustained the evolution of complex aerobic life. Coupled to the reduction of carbon dioxide, biological photosynthesis contributes foodstuffs for nutrition while recycling CO2 from the atmosphere and replacing it with O2. By utilizing sunlight to power these energy-requiring reactions, photosynthesis also serves as a model for addressing societal energy needs as we enter an era of diminishing fossil hydrocarbon resources. Understanding, at the molecular level, the dynamics and mechanism of how nature has solved this problem is of fundamental importance and could be critical to aid in the design of manufactured devices to accomplish the conversion of sunlight into useful electrochemical energy and transportable fuel in the foreseeable future. In order to understand the photosynthetic splitting of water by the Mn-OEC we need to be able to follow the reaction in real time at an atomic level. A powerful probe to study the electronic and molecular structure of the Mn-OEC is x-ray spectroscopy. Here, in particular x-ray emission spectroscopy (XES) has two crucial qualities for LCLS based time-dependent pump-probe studies of the Mn-OEC: a) it directly probes the Mn oxidation state and ligation, b) it can be performed with wavelength dispersive optics to avoid the necessity of scanning in pump probe experiments. Recent results and the planned time dependent experiments at LCLS will be discussed. )

  10. Landau level lifetimes in an InAs/AlSb quantum well determined by a picosecond far-infrared pump-probe technique

    NARCIS (Netherlands)

    Murdin, B. N.; KamalSaadi, M.; Ciesla, C. M.; Pidgeon, C. R.; Langerak, Cjgm; Stradling, R. A.; Gornik, E.

    1997-01-01

    We present measurements of Landau level lifetimes in a doped quantum well structure of InAs/AlSb using a combination of pump-probe and saturation spectroscopy measurements. The cyclotron resonance was studied using far-infrared radiation from a free-electron laser has yielded the energy relaxation

  11. Atmospheric measurements of total OH reactivity: Intercomparison of the pump-probe technique and the comparative reactivity method

    Science.gov (United States)

    Dusanter, Sebastien; Hansen, Robert; Leonardis, Thierry; Schoemaecker, Coralie; Blocquet, Marion; Fittschen, Christa; Hanoune, Benjamin; Sinha, Vinayak; Stevens, Philip; Locoge, Nadine

    2013-04-01

    The hydroxyl radical (OH) drives the oxidation of organic trace gases that can lead to the production of ozone and secondary organic aerosols in the atmosphere. A complete understanding of the sources and sinks of OH is therefore important to address issues related to both air quality and climate change. However, recent measurements of total OH reactivity [1-2], which is the inverse of the OH lifetime, have pointed out that our understanding of OH sinks is still incomplete and important reactive trace gases have not yet been identified. These measurements of total OH reactivity are of particular interest since they provide a critical test of our understanding of the OH budget. Three techniques are available to measure the total OH reactivity, including the total OH loss rate method [3], the pump-probe method [4], and the comparative reactivity method (CRM) [5]. While the first two methods are based on direct measurements of OH decays using laser-induced fluorescence instruments, the CRM is based on a different approach in which a tracer molecule is detected instead of OH to determine the ambient OH loss rate. As these instruments were deployed in different field campaigns, intercomparison exercises would be useful to ensure the accuracy of the measurements. However, such intercomparisons have not yet been published. An informal intercomparison involving a CRM instrument from the Ecole des Mines de Douai (EMD) and a pump-probe instrument from the laboratory Physicochimie des Processus de Combustion et de l'Atmosphere (PC2A) took place in an urban environment at the university of Lille (France). The two OH reactivity instruments measured continuously side by side for a duration of two weeks. Collocated measurements of trace gases were also performed using O3, NOx and SO2 monitors, as well as two automated chromatographic instruments capable of measuring more than 50 volatile organic compounds (VOC). We will present cross calibrations of the two OH reactivity

  12. Optical beam transport to a remote location for low jitter pump-probe experiments with a free electron laser

    Directory of Open Access Journals (Sweden)

    P. Cinquegrana

    2014-04-01

    Full Text Available In this paper we propose a scheme that allows a strong reduction of the timing jitter between the pulses of a free electron laser (FEL and external laser pulses delivered simultaneously at the FEL experimental stations for pump-probe–type experiments. The technique, applicable to all seeding-based FEL schemes, relies on the free-space optical transport of a portion of the seed laser pulse from its optical table to the experimental stations. The results presented here demonstrate that a carefully designed laser beam transport, incorporating also a transverse beam position stabilization, allows one to keep the timing fluctuations, added by as much as 150 m of free space propagation and a number of beam folding mirrors, to less than 4 femtoseconds rms. By its nature our scheme removes the major common timing jitter sources, so the overall jitter in pump-probe measurements done in this way will be below 10 fs (with a margin to be lowered to below 5 fs, much better than the best results reported previously in the literature amounting to 33 fs rms.

  13. Polarization control method for UV writing of advanced bragg gratings

    DEFF Research Database (Denmark)

    Deyerl, Hans-Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We report the application of the polarization control method for the UV writing of advanced fiber Bragg gratings (FBG). We demonstrate the strength of the new method for different apodization profiles, including the Sinc-profile and two designs for dispersion-free square filters. The method has...

  14. Control over the Dissociation of Highly Excited Oxygen in Attosecond XUV Pump- IR Probe experiments

    Science.gov (United States)

    Timmers, Henry; Shivaram, Niranjan; Sandhu, Arvinder

    2013-05-01

    We present results on the phase and amplitude control over the photodissociation yield of O2+ in a pump-probe experiment. Using an attosecond pulse train, we create excited state wavepackets along both the B and c state pathways of O2+. We use a two-IR pulse probe to steer the wavepacket. By tuning the excitation spectrum and phase between the two IR pulses, we find we can modulate the dissociated O+ yield with the frequency of IR intensity modulation and control the phase difference between the two dissociation pathways. This work was supported by NSF grant PHY-0955274.

  15. Characterisation of the UFXC32k hybrid pixel detector for time-resolved pump-probe diffraction experiments at Synchrotron SOLEIL

    Science.gov (United States)

    Dawiec, A.; Maj, P.; Ciavardini, A.; Gryboś, P.; Laulhé, C.; Menneglier, C.; Szczygieł, R.

    2017-03-01

    The experimental set-up for time-resolved studies of ultra-fast photo-induced structural dynamics at the Synchrotron SOLEIL is based on a general pump-probe scheme that has been developed and implemented on the CRISTAL hard X-ray diffraction beamline [1,2]. In a so-called pump-probe cycle, the sample is excited with an ultra-short laser pulse of ≈40 fs duration (the pump), and induced changes in its atomic structure are studied by measuring, with a precisely controlled delay, a diffraction pattern from a single pulse of synchrotron radiation (the probe) with a 2-D pixel detector. An improvement to the classical scheme is proposed, where the sample's response is probed at two different delays after each laser excitation. The first measurement at short delays allows studying the photo-induced dynamics. The second one is a reference measurement taken after sample's relaxation, which permits detection of drifts in the experimental conditions (e.g. beam misalignment, sample degradation). A hybrid pixel detector with a very fast readout time, a high dynamic range and extended linearity was tested to achieve the experiment objectives. In this paper, the first results obtained with the UFXC32k single photon counting detector are presented.

  16. Development of a Pump-Probe System using a Non-Coated ZnSe Beam Splitter Cube for an MIR-FEL

    CERN Document Server

    Heya, Manabu; Horiike, Hiroshi; Ishii, Katsonuri; Suzuki, Sachiko

    2004-01-01

    A pump-probe technique is essential for a proper understanding of laser interaction with tissue and material. Our pump-probe system divides the incident mid-infrared Free Electron Laser (MIR-FEL) into two beams with equal intensity, and crosses simultaneously the two incoming beams at the same position. One is for a pump beam, another is for a probe beam. Time-resolved absorption spectroscopy involving this technique gives us information on the vibrational dynamics of molecules. We have developed this system for an MIR-FEL using a non-coating ZnSe beam splitter cube. The beam splitter cube is composed of two ZnSe prisms in the shape like a trapezoid. The two pulses with equal intensity are generated due to Fresnel reflection and transmission at the boundary between two prisms, then are reflected due to total reflection at other side boundaries between each prism and air, and illuminate simultaneously the same spot. We have conducted a proof-of-concept of experiment of this system using an MIR-FEL. We showed t...

  17. Polarization-controlled asymmetric excitation of surface plasmons

    KAUST Repository

    Xu, Quan

    2017-08-28

    Free-space light can be coupled into propagating surface waves at a metal–dielectric interface, known as surface plasmons (SPs). This process has traditionally faced challenges in preserving the incident polarization information and controlling the directionality of the excited SPs. The recently reported polarization-controlled asymmetric excitation of SPs in metasurfaces has attracted much attention for its promise in developing innovative plasmonic devices. However, the unit elements in these works were purposely designed in certain orthogonal polarizations, i.e., linear or circular polarizations, resulting in limited two-level polarization controllability. Here, we introduce a coupled-mode theory to overcome this limit. We demonstrated theoretically and experimentally that, by utilizing the coupling effect between a pair of split-ring-shaped slit resonators, exotic asymmetric excitation of SPs can be obtained under the x-, y-, left-handed circular, and right-handed circular polarization incidences, while the polarization information of the incident light can be preserved in the excited SPs. The versatility of the presented design scheme would offer opportunities for polarization sensing and polarization-controlled plasmonic devices.

  18. Intercomparison of the comparative reactivity method (CRM) and pump-probe technique for measuring total OH reactivity in an urban environment

    Science.gov (United States)

    Hansen, R. F.; Blocquet, M.; Schoemaecker, C.; Léonardis, T.; Locoge, N.; Fittschen, C.; Hanoune, B.; Stevens, P. S.; Sinha, V.; Dusanter, S.

    2015-10-01

    The investigation of hydroxyl radical (OH) chemistry during intensive field campaigns has led to the development of several techniques dedicated to ambient measurements of total OH reactivity, which is the inverse of the OH lifetime. Three techniques are currently used during field campaigns, including the total OH loss rate method, the pump-probe method, and the comparative reactivity method. However, no formal intercomparison of these techniques has been published so far, and there is a need to ensure that measurements of total OH reactivity are consistent among the different techniques. An intercomparison of two OH reactivity instruments, one based on the comparative reactivity method (CRM) and the other based on the pump-probe method, was performed in October 2012 in a NOx-rich environment, which is known to be challenging for the CRM technique. This study presents an extensive description of the two instruments, the CRM instrument from Mines Douai (MD-CRM) and the pump-probe instrument from the University of Lille (UL-FAGE), and highlights instrumental issues associated with the two techniques. It was found that the CRM instrument used in this study underestimates ambient OH reactivity by approximately 20 % due to the photolysis of volatile organic compounds (VOCs) inside the sampling reactor; this value is dependent on the position of the lamp within the reactor. However, this issue can easily be fixed, and the photolysis of VOCs was successfully reduced to a negligible level after this intercomparison campaign. The UL-FAGE instrument may also underestimate ambient OH reactivity due to the difficulty to accurately measure the instrumental zero. It was found that the measurements are likely biased by approximately 2 s-1, due to impurities in humid zero air. Two weeks of ambient sampling indicate that the measurements performed by the two OH reactivity instruments are in agreement, within the measurement uncertainties for each instrument, for NOx mixing ratios

  19. Temperature dependant thermal and mechanical properties of a metal-phase change layer interface using the time resolved pump probe technique

    International Nuclear Information System (INIS)

    Schick, V; Battaglia, J-L; Kusiak, A; Rossignol, C; Wiemer, C

    2011-01-01

    Time Resolved Pump Probe (TRPP) technique has been implemented to study the thermal and mechanical properties of Ge 2 Sb 2 Te 5 (GST) film deposited on a silicon substrate. According to the knowledge of the thermal properties of the GST layer, the temperature dependant Thermal Boundary Resistance (TBR) at the metal-GST interface is evaluated. Measuring the acoustic oscillation and more particularly its damping leads to characterize the adhesion at the metal - GST interface. This quantity can be efficiently related to the temperature dependent TBR in the 25 deg. C - 400 deg. C range. The TBR increases with temperature and follows the changes of the crystalline structure of materials. A linear relation between the acoustic reflection coefficient and the logarithm of the thermal boundary resistance is found.

  20. Electron-nuclear spin dynamics of Ga centers in GaAsN dilute nitride semiconductors probed by pump-probe spectroscopy

    Science.gov (United States)

    Sandoval-Santana, J. C.; Ibarra-Sierra, V. G.; Azaizia, S.; Carrère, H.; Bakaleinikov, L. A.; Kalevich, V. K.; Ivchenko, E. L.; Marie, X.; Amand, T.; Balocchi, A.; Kunold, A.

    2018-03-01

    We propose an experimental procedure to track the evolution of electronic and nuclear spins in Ga2+ centers in GaAsN dilute semiconductors. The method is based on a pump-probe scheme that enables to monitor the time evolution of the three components of the electronic and nuclear spin variables. In contrast to other characterization methods, as nuclear magnetic resonance, this one only needs moderate magnetic fields (B≈ 10 mT), and does not require microwave irradiation. Specifically, we carry out a series of tests for different experimental conditions in order to optimize the procedure for maximum sensitivity in the measurement of the circular degree of polarization. Based on previous experimental results and the theoretical calculations presented here, we estimate that the method could yield a time resolution of about 10ps.

  1. Two-Copy Wavelength Conversion of an 80 Gbit/s Serial Data Signal Using Cross-Phase Modulation in a Silicon Nanowire and Detailed Pump-Probe Characterisation

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.; Dailey, J. M.

    2012-01-01

    We experimentally demonstrate 80 Gbit/s wavelength conversion to two copies by simultaneously extracting the blue- and red-shifted sidebands from XPM in a silicon nanowire. Bit error rates of 10-9 with only ~2 dB power penalty is achieved for both sidebands. Detailed pump-probe characterisation...

  2. Scheme for femtosecond-resolution pump-probe experiments at XFELs with two-color ten GW-level X-ray pulses

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2010-01-01

    This paper describes a scheme for pump-probe experiments that can be performed at LCLS and at the European XFEL and determines what additional hardware development will be required to bring these experiments to fruition. It is proposed to derive both pump and probe pulses from the same electron bunch, but from different parts of the tunable-gap baseline undulator. This eliminates the need for synchronization and cancels jitter problems. The method has the further advantage to make a wide frequency range accessible at high peak-power and high repetition-rate. An important feature of the proposed scheme is that the hardware requirement is minimal. Our technique is based in essence on the ''fresh'' bunch technique. For its implementation it is sufficient to substitute a single undulator module with short magnetic delay line, i.e. a weak magnetic chicane, which delays the electron bunch with respect to the SASE pulse of half of the bunch length in the linear stage of amplification. This installation does not perturb the baseline mode of operation. We present a feasibility study and we make exemplifications with the parameters of the SASE2 line of the European XFEL. (orig.)

  3. Origin of the thermal expansion anomaly in layered Bi2X3 topological insulators: Ultrafast time-resolved pump-probe experiments and theory

    Science.gov (United States)

    Prakash, Gyan; Pal, Koushik; Jain, Manish; Waghmare, U. V.; Sood, A. K.

    2017-08-01

    Recent experiments on the thermal expansion of Sb2Te3 , a prototypical example of strong three-dimensional topological insulators, have shown an intriguing anomaly in the thermal expansion coefficient along the hexagonal axis (α ∥), which drops sharply to almost zero in a narrow range of temperature around ˜225 K. With no accompanying signatures in other properties, the origin of this anomaly is not understood. We present here femtosecond pump-probe differential reflectivity measurements on single crystals of Sb2Te3 as a function of temperature from 3 to 300 K to determine the temperature dependence of coherent optical and acoustic phonons along with the dynamics of the photoexcited carriers. We find clearly anomalous temperature dependence of the parameters associated with vibrational and electronic relaxation in the narrow temperature range of 200-250 K. Within first-principles density functional theoretical analysis, we show that the observed anomalies can be explained with a mechanism of formation of stacking faults stabilized by vibrational entropy above 200 K. As a similar anomaly in the thermal expansion is also observed in other chalcogenides in the same family, the proposed mechanism may also be applicable to these layered strong topological insulators.

  4. Excitation-Dependent Carrier lifetime and Diffusion Length in Bulk CdTe Determined by Time-Resolved Optical Pump-Probe Techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Kuciauskas, Darius [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Scajev, Patrik [Vilnius University; Miasojedovas, Saulius [Vilnius University; Mekys, Algirdas [Vilnius University; Lynn, Kelvin G. [Washington State University; Swain, Santosh K. [Washington State University; Jarasiunas, Kestutis [Vilnius University

    2018-01-11

    We applied time-resolved pump-probe spectroscopy based on free carrier absorption and light diffraction on a transient grating for direct measurements of the carrier lifetime and diffusion coefficient D in high-resistivity single crystal CdTe (codoped with In and Er). The bulk carrier lifetime t decreased from 670 +/-50 ns to 60 +/- 10 ns with increase of excess carrier density N from 10^16 to 5 x 10^18 cm-3 due to the excitation-dependent radiative recombination rate. In this N range, the carrier diffusion length dropped from 14 um to 6 um due to lifetime decrease. Modeling of in-depth (axial) and in-plane (lateral) carrier diffusion provided the value of surface recombination velocity S = 6 x 10^5 cm/s for the untreated surface. At even higher excitations, in the 10^19-3 x 10^20 cm-3 density range, D increase from 5 to 20 cm^2/s due to carrier degeneracy was observed.

  5. IR intensity

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2015-01-01

    Definitions, formulas, and code for producing epsilon values (molar absorption coefficients) and IR spectral curve from 'Gaussian' FREQ output.......Definitions, formulas, and code for producing epsilon values (molar absorption coefficients) and IR spectral curve from 'Gaussian' FREQ output....

  6. Innovation and optimization of a method of pump-probe polarimetry with pulsed laser beams in view of a precise measurement of parity violation in atomic cesium

    International Nuclear Information System (INIS)

    Chauvat, D.

    1997-10-01

    While Parity Violation (PV) experiments on highly forbidden transitions have been using detection of fluorescence signals; our experiment uses a pump-probe scheme to detect the PV signal directly on a transmitted probe beam. A pulsed laser beam of linear polarisation ε 1 excites the atoms on the 6S-7S cesium transition in a colinear electric field E || k(ex). The probe beam (k(pr) || k(ex)) of linear polarisation ε 2 tuned to the transition 7S-6P(3/2) is amplified. The small asymmetry (∼ 10 -6 ) in the gain that depends on the handedness of the tri-hedron (E, ε 1 , ε 2 ) is the manifestation of the PV effect. This is measured as an E-odd apparent rotation of the plane of polarization of the probe beam; using balanced mode polarimetry. New criteria of selection have been devised, that allow us to distinguish the true PV-signal against fake rotations due to electromagnetic interferences, geometrical effects, polarization imperfections, or stray transverse electric and magnetic fields. These selection criteria exploit the symmetry of the PV-rotation - linear dichroism - and the revolution symmetry of the experiment. Using these criteria it is not only possible to reject fake signals, but also to elucidate the underlying physical mechanisms and to measure the relevant defects of the apparatus. The present signal-to-noise ratio allows embarking in PV measurements to reach the 10% statistical accuracy. A 1% measurement still requires improvements. Two methods have been demonstrated. The first one exploits the amplification of the asymmetry at high gain - one major advantage provided by our detection method based on stimulated emission. The second method uses both a much higher incident intensity and a special dichroic component which magnifies tiny polarization rotations. (author)

  7. Efficient Vibrational Energy Transfer through Covalent Bond in Indigo Carmine Revealed by Nonlinear IR Spectroscopy.

    Science.gov (United States)

    He, Xuemei; Yu, Pengyun; Zhao, Juan; Wang, Jianping

    2017-10-12

    Ultrafast vibrational relaxation and structural dynamics of indigo carmine in dimethyl sulfoxide were examined using femtosecond pump-probe infrared and two-dimensional infrared (2D IR) spectroscopies. Using the intramolecularly hydrogen-bonded C═O and delocalized C═C stretching modes as infrared probes, local structural and dynamical variations of this blue dye molecule were observed. Energy relaxation of the vibrationally excited C═O stretching mode was found to occur through covalent bond to the delocalized aromatic vibrational modes on the time scale of a few picoseconds or less. Vibrational quantum beating was observed in magic-angle pump-probe, anisotropy, and 2D IR cross-peak dynamics, showing an oscillation period of ca. 1010 fs, which corresponds to the energy difference between the C═O and C═C transition frequency (33 cm -1 ). This confirms a resonant vibrational energy transfer happened between the two vibrators. However, a more efficient energy-accepting mode of the excited C═O stretching was believed to be a nearby combination and/or overtone mode that is more tightly connected to the C═O species. On the structural aspect, dynamical-time-dependent 2D IR spectra reveal an insignificant inhomogeneous contribution to time-correlation relaxation for both the C═O and C═C stretching modes, which is in agreement with the generally believed structural rigidity of such conjugated molecules.

  8. Low-Dispersion Fibre Bragg Gratings Written Using the Polarization Control Method

    DEFF Research Database (Denmark)

    Deyerl, Hans Jürgen; Plougmann, Nikolai; Jensen, Jesper Bo Damm

    2002-01-01

    We present two fibre Bragg gratings with reduced in-band dispersion for DWDM applications. The gratings were designed by the inverse scattering method and fabricated using the novel polarization control method for UV-writing of advanced gratings.......We present two fibre Bragg gratings with reduced in-band dispersion for DWDM applications. The gratings were designed by the inverse scattering method and fabricated using the novel polarization control method for UV-writing of advanced gratings....

  9. Inyang, IR

    African Journals Online (AJOL)

    Inyang, IR. Vol 5, No 4 (2009) - Articles Changes in Total Protein and Transaminase Activities in Clarias Gariepinus Exposed to Diazinon Abstract. ISSN: 0794-4721. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

  10. Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution.

    Science.gov (United States)

    Henn, T; Kiessling, T; Ossau, W; Molenkamp, L W; Biermann, K; Santos, P V

    2013-12-01

    We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast "white light" supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

  11. Mechanisms of Cell Polarity-Controlled Epithelial Homeostasis and Immunity in the Intestine.

    Science.gov (United States)

    Klunder, Leon J; Faber, Klaas Nico; Dijkstra, Gerard; van IJzendoorn, Sven C D

    2017-07-05

    Intestinal epithelial cell polarity is instrumental to maintain epithelial homeostasis and balance communications between the gut lumen and bodily tissue, thereby controlling the defense against gastrointestinal pathogens and maintenance of immune tolerance to commensal bacteria. In this review, we highlight recent advances with regard to the molecular mechanisms of cell polarity-controlled epithelial homeostasis and immunity in the human intestine. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  12. Tunable and switchable multi-wavelength erbium-doped fiber laser with highly nonlinear photonic crystal fiber and polarization controllers

    International Nuclear Information System (INIS)

    Liu, X M; Lin, A; Zhao, W; Lu, K Q; Wang, Y S; Zhang, T Y; Chung, Y

    2008-01-01

    We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature

  13. Ultrafast vibrational population transfer dynamics in 2-acetylcyclopentanone studied by 2D IR spectroscopy.

    Science.gov (United States)

    Park, Sungnam; Ji, Minbiao

    2011-03-14

    2-Acetylcyclopentanone (2-ACP), which is a β-dicarbonyl compound, undergoes keto-enol isomerization, and its enol tautomers are stabilized by a cyclic intramolecular hydrogen bond. 2-ACP (keto form) has symmetric and asymmetric vibrational modes of the two carbonyl groups at 1748 and 1715 cm(-1) , respectively, which are well separated from the carbonyl modes of its enol tautomers in the FTIR spectrum. We have investigated 2-ACP dissolved in carbon tetrachloride by 2D IR spectroscopy and IR pump-probe spectroscopy. Vibrational population transfer dynamics between the two carbonyl modes were observed by 2D IR spectroscopy. To extract the population exchange dynamics (i.e., the down- and uphill population transfer rate constants), we used the normalized volumes of the cross-peaks with respect to the diagonal peaks at the same emission frequency and the survival and conditional probability functions. As expected, the downhill population transfer time constant (3.2 ps) was measured to be smaller than the uphill population transfer time constant (3.8 ps). In addition, the vibrational population relaxation dynamics of the two carbonyl modes were observed to be the same within the experimental error and were found to be much slower than vibrational population transfer between two carbonyl modes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Circular polarization control for the European XFEL in the soft X-ray regime

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2011-06-01

    The possibility of producing X-ray radiation with high degree of circular polarization is an important asset at XFEL facilities. Polarization control is most important in the soft X-ray region.However, the baseline of the European XFEL, including the soft X-ray SASE3 line, foresees planar undulators only, yielding linearly-polarized radiation. It is clear that the lowest-risk strategy for implementing polarization control at SASE3 involves adding an APPLE II-type undulator at the end of the planar undulator, in order to exploit the micro bunching from the baseline FEL. Detailed experience is available in synchrotron radiation laboratories concerning the manufacturing of 5 m-long APPLE II undulators. However, the choice of a short helical radiator leads to the problem of background suppression. The driving idea of our proposal is that the background radiation can be suppressed by spatial filtering. This operation can be performed by inserting slits behind the APPLE II radiator, where the linearly-polarized radiation spot size is about 30 times larger than the radiation spot size from the helical radiator. The last 7 cells of the SASE3 undulator are left with an open gap in order to provide a total 42 m drift section for electron beam and radiation. Due to the presence of the drift the linearly-polarized radiation spot size increases, and the linearly polarized background radiation can be suppressed by the slits. At the same time, the microbunch structure is easily preserved, so that intense (100 GW) coherent radiation is emitted in the helical radiator. We propose a filtering setup consisting of a pair of water cooled slits for X-ray beam filtering and of a 5 m-long magnetic chicane, which creates an offset for slit installation immediately behind the helical radiator. Electrons and X-rays are separated before the slits by the magnetic chicane, so that the electron beam can pass by the filtering setup without perturbations. Based on start-to-end simulations we

  15. Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

    Science.gov (United States)

    Boll, D. I. R.; Fojón, O. A.

    2017-12-01

    We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets.

  16. Attosecond polarization control in atomic RABBITT-like experiments assisted by a circularly polarized laser

    International Nuclear Information System (INIS)

    Boll, D I R; Fojón, O A

    2017-01-01

    We study theoretically the single ionization of noble gas atoms by the combined action of an attosecond pulse train with linear polarization and an assistant laser field with circular polarization. We employ a non-perturbative model that under certain approximations gives closed-form expressions for the angular distributions of photoelectrons. Interestingly, our model allow us to interpret these angular distributions as two-centre interferences where the orientation and the modulus of the separation vector between the virtual emitters is governed by the assistant laser field. Additionally, we show that such a configuration of light fields is similar to the polarization control technique, where both the attosecond pulse train and the assistant laser field have linear polarizations whose relative orientation may be controlled. Moreover, in order to compare our results with the available experimental data, we obtain analytical expressions for the cross sections integrated over the photoelectron emission angles. By means of these expressions, we define the ‘magic time’ as the delay for which the total cross sections for atomic targets exhibit the same functional form as the one of the monochromatic photoionization of diatomic molecular targets. (paper)

  17. Temperature sensitivity analysis of polarity controlled electrostatically doped tunnel field-effect transistor

    Science.gov (United States)

    Nigam, Kaushal; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

    2016-09-01

    The conventional tunnel field-effect transistors (TFETs) have shown potential to scale down in sub-22 nm regime due to its lower sub-threshold slope and robustness against short-channel effects (SCEs), however, sensitivity towards temperature variation is a major concern. Therefore, for the first time, we investigate temperature sensitivity analysis of a polarity controlled electrostatically doped tunnel field-effect transistor (ED-TFET). Different performance metrics and analog/RF figure-of-merits were considered and compared for both devices, and simulations were performed using Silvaco ATLAS device tool. We found that the variation in ON-state current in ED-TFET is almost temperature independent due to electrostatically doped mechanism, while, it increases in conventional TFET at higher temperature. Above room temperature, the variation in ION, IOFF, and SS sensitivity in ED-TFET are only 0.11%/K, 2.21%/K, and 0.63%/K, while, in conventional TFET the variations are 0.43%/K, 2.99%/K, and 0.71%/K, respectively. However, below room temperature, the variation in ED-TFET ION is 0.195%/K compared to 0.27%/K of conventional TFET. Moreover, it is analysed that the incomplete ionization effect in conventional TFET severely affects the drive current and the threshold voltage, while, ED-TFET remains unaffected. Hence, the proposed ED-TFET is less sensitive towards temperature variation and can be used for cryogenics as well as for high temperature applications.

  18. Design of a polarization-controlled launcher for the ECH system on J-TEXT

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.H.; Xia, D.H., E-mail: xiadh@hust.edu.cn; Sun, D.L.; Wang, Z.J.; Xiao, J.X.; Zeng, Z.; Cui, F.T.; Yu, Z.X.; Zhuang, G.

    2016-11-15

    Highlights: • A polarization-controlled launcher is designed for the ECH system on J-TEXT. • The coordinate transformation method is used for the polarizer design of the launcher. • O-mode purity of no less than 97% for all possible injection can be achieved with this launcher. - Abstract: Based on main components including gyrotrons, magnets, auxiliary power supplies, transmission parts, etc. donated by the Culham Science Center, an electron cyclotron heating (ECH) system with four 60 GHz/200 kW/0.5 s subunits is being developed on J-TEXT for effective plasma heating and MHD studies. A launcher has been designed to inject the beam of the first subunit into plasma with the desired polarization and direction. The launcher mainly consists of a polarizer, an ellipsoidal mirror, a steerable flat mirror and a gate valve. When the beam arrives at the launcher, it is firstly diffracted by the polarizer and then focused by the ellipsoidal mirror. Finally, the beam is delivered to plasma by the steerable mirror. Owing to the limited space of the port for beam injection, the scanning range in both the toroidal and poloidal direction is about −8° to 8°. With optimization design, the available mode purity for all possible injection is no less than 97% and the beam radius at the center of plasma is about 38 mm, making it possible for high efficient coupling and localized absorption of the wave power.

  19. IOT Overview: IR Instruments

    Science.gov (United States)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  20. Active polarization control of a 1.43 kW narrow linewidth fiber amplifier based on SPGD algorithm

    Science.gov (United States)

    Su, Rongtao; Liu, Yakun; Yang, Baolai; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Xu, Xiaojun

    2017-04-01

    Active polarization control of a high power fiber amplifier has been demonstrated. The master oscillator power amplifier system consisted of a narrow linewidth laser seed and a three-stage Yb-fiber amplifier. The narrow linewidth laser seed was generated by phase modulating a single frequency fiber laser using a white noise source. Maximum power of 1437 W was obtained from the main amplifier, which was limited by the available pump power. When the polarization state of the narrow linewidth (∼0.17 nm) laser was actively controlled by using a polarization controller based on stochastic parallel gradient descent algorithm, the polarization extinction ratio of the laser beam was more than 11.1 dB at the maximum output power.

  1. IR Hot Wave

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  2. Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

    International Nuclear Information System (INIS)

    Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

    2015-01-01

    We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

  3. Into the development of a model to assess beam shaping and polarization control effects on laser cutting

    Science.gov (United States)

    Rodrigues, Gonçalo C.; Duflou, Joost R.

    2018-02-01

    This paper offers an in-depth look into beam shaping and polarization control as two of the most promising techniques for improving industrial laser cutting of metal sheets. An assessment model is developed for the study of such effects. It is built upon several modifications to models as available in literature in order to evaluate the potential of a wide range of considered concepts. This includes different kinds of beam shaping (achieved by extra-cavity optical elements or asymmetric diode staking) and polarization control techniques (linear, cross, radial, azimuthal). A fully mathematical description and solution procedure are provided. Three case studies for direct diode lasers follow, containing both experimental data and parametric studies. In the first case study, linear polarization is analyzed for any given angle between the cutting direction and the electrical field. In the second case several polarization strategies are compared for similar cut conditions, evaluating, for example, the minimum number of spatial divisions of a segmented polarized laser beam to achieve a target performance. A novel strategy, based on a 12-division linear-to-radial polarization converter with an axis misalignment and capable of improving cutting efficiency with more than 60%, is proposed. The last case study reveals different insights in beam shaping techniques, with an example of a beam shape optimization path for a 30% improvement in cutting efficiency. The proposed techniques are not limited to this type of laser source, neither is the model dedicated to these specific case studies. Limitations of the model and opportunities are further discussed.

  4. IR and the Earth

    DEFF Research Database (Denmark)

    Corry, Olaf; Stevenson, Hayley

    2017-01-01

    politics and offers an account of how this builds on older ways in which the natural world has made up part of the stuff of international politics. Second, it surveys the main traditions and approaches to studying International Relations of the environment, painting a picture of diversification in two......, ‘what has the environment ever done for IR?’, before the plan for the rest of the book sketches the content and direction of the ensuing chapters that explore the problematique of International Relations and the Earth....

  5. Detailed IR aperture measurements

    CERN Document Server

    Bruce, Roderik; Garcia Morales, Hector; Giovannozzi, Massimo; Hermes, Pascal Dominik; Mirarchi, Daniele; Quaranta, Elena; Redaelli, Stefano; Rossi, Carlo; Skowronski, Piotr Krzysztof; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2016-01-01

    MD 1673 was carried out on October 5 2016, in order to investigate in more detail the available aperture in the LHC high-luminosity insertions at 6.5 TeV and β∗=40 cm. Previous aperture measurements in 2016 during commissioning had shown that the available aperture is at the edge of protection, and that the aperture bottleneck at β∗=40 cm in certain cases is found in the separation plane instead of in the crossing plane. Furthermore, the bottlenecks were consistently found in close to the upstream end of Q3 on the side of the incoming beam, and not in Q2 on the outgoing beam as expected from calculations. Therefore, this MD aimed at measuring IR1 and IR5 separately (at 6.5 TeV and β∗=40 cm, for 185 µrad half crossing angle), to further localize the bottlenecks longitudinally using newly installed BLMs, investigate the difference in aperture between Q2 and Q3, and to see if any aperture can be gained using special orbit bumps.

  6. Polarization controlled deep sub-wavelength periodic features written by femtosecond laser on nanodiamond thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Kuntumalla, Mohan; Srikanth, Vadali V. S. S., E-mail: vvsssse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Rajamudili, Kuladeep; Rao Desai, Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-04-21

    Deep sub-wavelength (Λ/λ = ∼0.22) periodic features are induced uniformly on a nanodiamond (ND) thin film surface using femtosecond (fs) laser irradiation (pulse duration = ∼110 fs and central wavelength of ∼800 nm). The topography of the surface features is controlled by the laser polarization. Orientation of features is perpendicular to laser polarization. Periodicity (spatial periodicity of < λ/4) of the surface features is less than the laser wavelength. This work gives an experimental proof of polarization controlled surface plasmon-fs laser coupling mechanism prompting the interaction between fs laser and solid matter (here ND thin film) which in turn is resulting in the periodic surface features. Scanning electron microscopy in conjunction with micro Raman scattering, X-ray diffraction, and atomic force microscopy are carried out to extract surface morphology and phase information of the laser irradiated regions. This work demonstrates an easy and efficient surface fabrication technique.

  7. The IRS-1 signaling system.

    Science.gov (United States)

    Myers, M G; Sun, X J; White, M F

    1994-07-01

    Insulin-receptor substrate 1 (IRS-1) is a principal substrate of the receptor tyrosine kinase for insulin and insulin-like growth factor 1, and a substrate for a tyrosine kinase activated by interleukin 4. IRS-1 undergoes multisite tyrosine phosphorylation and mediates downstream signals by 'docking' various proteins that contain Src homology 2 domains. IRS-1 appears to be a unique molecule; however, 4PS, a protein found mainly in hemopoietic cells, may represent another member of this family.

  8. IR seeker simulator and IR scene generation to evaluate IR decoy effectiveness; 2005BU1-EO

    NARCIS (Netherlands)

    Jong, W. de; Dam, F.A.M.; Kunz, G.J.; Schleijpen, H.M.A.

    2005-01-01

    IR decoys can be an effective countermeasure against IR guided anti ship missiles. However, it's not so easy to determine how the decoys should be deployed to get maximum effectiveness. A limitation of trials is that results are obtained for the specific trial condition only. Software tools have

  9. Ultrafast 2D IR microscopy.

    Science.gov (United States)

    Baiz, Carlos R; Schach, Denise; Tokmakoff, Andrei

    2014-07-28

    We describe a microscope for measuring two-dimensional infrared (2D IR) spectra of heterogeneous samples with μm-scale spatial resolution, sub-picosecond time resolution, and the molecular structure information of 2D IR, enabling the measurement of vibrational dynamics through correlations in frequency, time, and space. The setup is based on a fully collinear "one beam" geometry in which all pulses propagate along the same optics. Polarization, chopping, and phase cycling are used to isolate the 2D IR signals of interest. In addition, we demonstrate the use of vibrational lifetime as a contrast agent for imaging microscopic variations in molecular environments.

  10. CCD and IR array controllers

    Science.gov (United States)

    Leach, Robert W.; Low, Frank J.

    2000-08-01

    A family of controllers has bene developed that is powerful and flexible enough to operate a wide range of CCD and IR focal plane arrays in a variety of ground-based applications. These include fast readout of small CCD and IR arrays for adaptive optics applications, slow readout of large CCD and IR mosaics, and single CCD and IR array operation at low background/low noise regimes as well as high background/high speed regimes. The CCD and IR controllers have a common digital core based on user- programmable digital signal processors that are used to generate the array clocking and signal processing signals customized for each application. A fiber optic link passes image data and commands to VME or PCI interface boards resident in a host computer to the controller. CCD signal processing is done with a dual slope integrator operating at speeds of up to one Megapixel per second per channel. Signal processing of IR arrays is done either with a dual channel video processor or a four channel video processor that has built-in image memory and a coadder to 32-bit precision for operating high background arrays. Recent developments underway include the implementation of a fast fiber optic data link operating at a speed of 12.5 Megapixels per second for fast image transfer from the controller to the host computer, and supporting image acquisition software and device drivers for the PCI interface board for the Sun Solaris, Linux and Windows 2000 operating systems.

  11. #Occupy IR: Exposing the Orthodoxy

    Directory of Open Access Journals (Sweden)

    Ivan Manokha

    2012-03-01

    Full Text Available The #occupy IR/IPE initiative was created in response to the #occupy movement, whose own roots can be traced backed to the latest crisis of global finance. In this contribution, we link #occupy and the crisis in a different way. We argue that we must occupy IR/IPE because of the discipline’s failure to apprehend and acknowledge the crisis itself, just as the Occupy movement is calling for their overarching authorities to notice and help address the social and economic inequalities produced by this crisis. More precisely, we argue that the dominant academic orthodoxy, via a series of continuously reproduced dichotomies, has rendered IR/IPE incapable of dealing with a phenomenon as complex as the financial crisis...

  12. Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

    Directory of Open Access Journals (Sweden)

    Andras Franko

    2017-05-01

    Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

  13. Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/--IRS-1+/-Double Heterozygous (IR-IRS1dh) Mice.

    Science.gov (United States)

    Franko, Andras; Kunze, Alexander; Böse, Marlen; von Kleist-Retzow, Jürgen-Christoph; Paulsson, Mats; Hartmann, Ursula; Wiesner, Rudolf J

    2017-05-30

    Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR) +/- -insulin receptor substrate-1 (IRS-1) +/- double heterozygous (IR-IRS1dh) mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

  14. 3D printed polarizing grids for IR-THz synchrotron radiation

    Science.gov (United States)

    Ryu, Meguya; Linklater, Denver; Hart, William; Balčytis, Armandas; Skliutas, Edvinas; Malinauskas, Mangirdas; Appadoo, Dominique; Tan, Yaw-Ren Eugene; Ivanova, Elena P.; Morikawa, Junko; Juodkazis, Saulius

    2018-03-01

    Grid polarisers 3D-printed out of commercial acrilic resin were tested for the polariser function and showed spectral regions where the dichroic ratio {D}R> 1 and molecular and/or stress induced anisotropy. Metal-coated 3D-printed THz optical elements can find a range of applications in intensity and polarization control of IR-THz beams. The used 3D printing method allows for fabrication of an arbitrary high aspect ratio grid polarisers. Polarization analysis of synchrotron THz radiation was carried out with a standard stretched polyethylene polariser and revealed that the linearly polarized (horizontal) component contributes up to 22% ± 5% to the circular polarized synchrotron emission extracted by a gold-coated mirror with a horizontal slit inserted near the bending magnet edge. Comparison with theoretical predictions shows a qualitative match with dominance of the edge radiation.

  15. Relaxation and excitation electronic processes in dielectrics irradiated by ultrafast IR and VUV pulses; Processus electroniques d'excitation et de relaxation dans les solides dielectriques excites par des impulsions IR et XUV ultracourtes

    Energy Technology Data Exchange (ETDEWEB)

    Gaudin, J

    2005-11-15

    We studied excitation and relaxation of electrons involved during interaction of visible and VUV femtosecond pulses with dielectrics. The generated population of hot electrons, having energy of few eV to few tens of eV above the bottom of the conduction band, is responsible of phenomena ranging to defect creation to optical breakdown. Owing to two techniques: photoemission and transient photoconductivity we improve the understanding of the The first photoemission experiments deal with dielectrics irradiated by 30 fs IR pulses. The photoemission spectra measured show a large population of electrons which energy rise up to 40 eV. We interpret this result in terms of a new absorption process: direct multi-photons inter-branch transitions. The 2. type of photoemission experiments are time resolved 'pump/probe' investigation. We study the relaxation of electrons excited by a VUV pulses. We used the high order harmonics (HOH) as light sources. We found surprisingly long decay time in the range of ps timescale. Last type of experiments is photoconductivity studies of diamond samples. Using HOH as light source we measure the displacement current induced by excited electrons in the conduction band. Those electrons relax mainly by impact ionisation creating secondary electrons. Hence by probing the number of electrons we were able to measure the efficiency of these relaxation processes. We observe a diminution of this efficiency when the energy of exciting photons is above 20 eV. Owing to Monte-Carlo simulation we interpret this result in terms of band structure effect. (author)

  16. Shaped Ir-Ni bimetallic nanoparticles for minimizing Ir utilization in oxygen evolution reaction.

    Science.gov (United States)

    Lim, Jinkyu; Yang, Sungeun; Kim, Chanyeon; Roh, Chi-Woo; Kwon, Yongwoo; Kim, Yong-Tae; Lee, Hyunjoo

    2016-04-25

    Shaped Ir-Ni bimetallic nanoparticles were synthesized and used for electrocatalytic oxygen evolution reaction (OER). The obtained bimetallic nanoparticles showed significantly enhanced Ir mass activity and durability compared with Ir nanoparticles.

  17. WFC3 IR subarray anomaly

    Science.gov (United States)

    Bushouse, Howard

    2009-07-01

    Certain combinations of WFC3 IR subarray size and sample sequence yield images that show a sharp change in background level that exactly bi-sects each detector amplifier quadrant. The change in level has an amplitude of a few DN per pixel. The cause of this anomaly and its apparent correlation with subarray size and sample sequence is not understood. Given the 4 available subarray sizes and 11 available readout sample sequences, there are a total of 44 possible subarray mode readout combinations. To date, 14 of those combinations have been used on-orbit in either calibration and GO programs. Of those, 3 combinations show the anomaly. This program will obtain IR dark exposures in the remaining 30 readout combinations that have not yet been explored. This will add to our knowledge of which combinations show the anomaly and will therefore help us to understand its origin.

  18. Oferta ir akceptas vartojimo sutartyse

    OpenAIRE

    Ežerskytė, Ramunė

    2011-01-01

    Sutarčiai sudaryti paprastai reikia, kad viena šalis pasiūlytų sudaryti sutartį (oferta), o kita šalis sutiktų su pasiūlymu (akceptas). Sutarčių įvairovėje išskiriamos vartojimo sutartys, kurios dėl silpnesnės šalies apsaugos principo įgyvendinimo pasižymi tam tikrais ypatumais. Vartojimo sutarčių sudarymas pateikiant ofertą ir akceptą yra šio magistro baigiamojo darbo objektas. Magistro baigiamąjį darbą sudaro trys dalys. Pirmojoje darbo dalyje analizuojama vartojimo sutarties sąvoka ir spec...

  19. Hidroenergijos panaudojimo raida ir perspektyvos

    OpenAIRE

    Vizbaras, Andrius

    2008-01-01

    Ilgą laiko tarpą hidroenergetika vertinta kaip sėkminga žmonijos vystimosi ir akivaizdžios naudos išraiška, pastaruoju metu siejama su reikšmingu poveikiu gamtinei aplinkai bei įtaka klimato kaitai. Lygumų šalyse, net ir mažos galios hidroelektrinių statyba pareikalauja didelių užliejamų žemės plotų. Šiame darbe atlikome aštuoniasdešimties iki 2007 metų pastatytų hidroelektrinių poveikio aplinkai analizę bei aptarėme galimą „Lietuvos hidroenergetinių išteklių schemoje„ numatytų statyti HE pov...

  20. Climate Prediction Center IR 4km Dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CPC IR 4km dataset was created from all available individual geostationary satellite data which have been merged to form nearly seamless global (60N-60S) IR...

  1. Isolated Gramicidin Peptides Probed by IR Spectroscopy

    NARCIS (Netherlands)

    Rijs, A. M.; Kabelac, M.; Abo-Riziq, A.; Hobza, P.; de Vries, M. S.

    2011-01-01

    We report double-resonant IR/UV ion-dip spectroscopy of neutral gramicidin peptides in the gas phase. The IR spectra of gramicidin A and C, recorded in both the 1000 cm(-1) to 1800 cm(-1) and the 2700 to 3750 cm(-1) region, allow structural analysis. By studying this broad IR range, various local

  2. Diffraction-limited IR Microspectroscopy with IRENI

    Science.gov (United States)

    J. Sedlmair; B. Illman; M. Unger; C. Hirschmugl

    2012-01-01

    In a unique way, IRENI (Infrared environmental Imaging), operated at the Synchrotron Radiation Center in Madison, combines IR spectroscopy and IR imaging, revealing the chemical morphology of a sample. Most storage ring based IR confocal microscopes have to overcome a trade-off between spatial resolution versus...

  3. Coprates Chasma Landslides in IR

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Today's daytime IR image is of a portion of Coprates Chasma, part of Valles Marineris. As with yesterday's image, this image shows multiple large landslides. Image information: IR instrument. Latitude -8.2, Longitude 300.2 East (59.8 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  4. Innovations in IR projector arrays

    Science.gov (United States)

    Cole, Barry E.; Higashi, B.; Ridley, Jeff A.; Holmen, J.; Newstrom, K.; Zins, C.; Nguyen, K.; Weeres, Steven R.; Johnson, Burgess R.; Stockbridge, Robert G.; Murrer, Robert Lee; Olson, Eric M.; Bergin, Thomas P.; Kircher, James R.; Flynn, David S.

    2000-07-01

    In the past year, Honeywell has developed a 512 X 512 snapshot scene projector containing pixels with very high radiance efficiency. The array can operate in both snapshot and raster mode. The array pixels have near black body characteristics, high radiance outputs, broad band performance, and high speed. IR measurements and performance of these pixels will be described. In addition, a vacuum probe station that makes it possible to select the best die for packaging and delivery based on wafer level radiance screening, has been developed and is in operation. This system, as well as other improvements, will be described. Finally, a review of the status of the present projectors and plans for future arrays is included.

  5. IR Thermography NDE of ISS Radiator Panels

    Science.gov (United States)

    Koshti, Ajay; Winfree, William; Morton, Richard; Wilson, Walter; Reynolds, Gary

    2010-01-01

    The presentation covers an active and a passive infrared (IR) thermography for detection of delaminations in the radiator panels used for the International Space Station (ISS) program. The passive radiator IR data was taken by a NASA astronaut in an extravehicular activity (EVA) using a modified FLIR EVA hand-held camera. The IR data could be successfully analyzed to detect gross facesheet disbonds. The technique used the internal hot fluid tube as the heat source in analyzing the IR data. Some non-flight ISS radiators were inspected using an active technique of IR flash thermography to detect disbond of face sheet with honeycomb core, and debonds in facesheet overlap areas. The surface temperature and radiated heat emission from flight radiators is stable during acquisition of the IR video data. This data was analyzed to detect locations of unexpected surface temperature gradients. The flash thermography data was analyzed using derivative analysis and contrast evolutions. Results of the inspection are provided.

  6. Feminist Challenge to the Mainstream IR

    OpenAIRE

    Aydın, Gülşen

    2016-01-01

    This study deals with the Feminist challenge to the Mainstream International Relations Discipline (IR) - rationalist theories, especially Realism - and the mainstream's responses to this challenge. It addresses the issue in five steps. Firstly, it sheds light on how Feminism is related to International Relations. Secondly, it examines how Feminist IR theorists criticize the Mainstream IR due to its state-centric approach and argue that being obsessed with anarchic international system prevent...

  7. Measuring Collimator Infrared (IR) Spectral Transmission

    Science.gov (United States)

    2016-05-01

    TECHNICAL REPORT RDMR-WD-16-15 MEASURING COLLIMATOR INFRARED ( IR ) SPECTRAL TRANSMISSION Christopher L. Dobbins Weapons...AND DATES COVERED Final 4. TITLE AND SUBTITLE Measuring Collimator Infrared ( IR ) Spectral Transmission 5. FUNDING NUMBERS 6. AUTHOR(S) Christopher L...release; distribution is unlimited. 12b. DISTRIBUTION CODE A 13. ABSTRACT (Maximum 200 Words) Several Infrared ( IR ) imaging systems have been measured

  8. How to remedy Eurocentrism in IR?

    DEFF Research Database (Denmark)

    Bilgin, Pinar

    2016-01-01

    While IR's Eurocentric limits are usually acknowledged, what those limits mean for theorizing about the international is seldom clarified. In The Global Transformation, Buzan and Lawson offer a 'composite approach' that goes some way towards addressing IR's Eurocentrism, challenging existing myths...... helps us recognize what is missing from IR theorizing - conceptions of the international by 'others' who also constitute the international. I illustrate this point by focussing on a landmark text on Ottoman history, Ortayll's The Longest Century of the Empire....

  9. Increasing Medical Student Exposure to IR through Integration of IR into the Gross Anatomy Course.

    Science.gov (United States)

    DePietro, Daniel M; Kiefer, Ryan M; Redmond, Jonas W; Workman, Alan D; Nadolski, Gregory J; Gade, Terence P; Trerotola, Scott O; Hunt, Stephen J

    2017-10-01

    To compare medical student knowledge of and interest in interventional radiology (IR) before and after the integration of an IR lecture series within the gross anatomy course. Four elective IR lectures were scheduled to coincide with the relevant anatomy dissection curriculum. Anonymous surveys were distributed to 146 students before and after the lectures regarding students' knowledge of and interest in IR, responsibilities of an IR physician, and IR training pathways. Those who did not attend served as controls. Response rates were 67% (n = 98) in the prelecture group, 55% (n = 22) in the group who attended the lecture, and 28% (n = 30) in the control group. A total of 73% of the prelecture group reported little knowledge of IR compared with other specialties. This decreased to 27% in those who attended the lecture (P IR than any other specialty, compared with 7% of controls (P value not significant) and 2% of the prelecture group (P IR procedures (mean, 1.82) than the prelecture group (mean, 0.57; P IR, compared with 24% in the prelecture group and 33% in the control group (P IR residency, compared with 5% in the prelecture group and 33% in the control group (P IR education into the gross anatomy course proved to be a highly effective way of teaching preclinical students about IR and generating interest in the field. Copyright © 2017 SIR. All rights reserved.

  10. Silver electrodeposition over an Ir/Ir oxide electrode

    International Nuclear Information System (INIS)

    Lezna, R.O.; Tacconi, N.R. de; Arvia, A.J.

    1984-01-01

    Changes in electrochemical response brought about by the electrodeposition of small amounts of silver on oxide covered iridium electrodes are examined in relation to the semiconducting properties of the oxide. The charge involved in both silver and hydrogen atoms was found to remain practically constant and independent of the oxide thickness which was gradually increased by potentiodynamic cycling up to greater anodic switching potentials. This result suggests that the charge transfer for both processes takes place at the bare metal. The considerable increase in the film conductivity when the potential is above ductivity when the potential is above oV (MSE) is shown by the fact that under certain controlled conditions the silver electroreduction/ electroxidation reactions are shifted to a more anodic potential region where the oxide becomes conductor and participates in the charge transfer process. Silver loading increases the electrical conductivity of the oxide providing a large cross section for the electroxidation of Ir, particularly in a region where the oxide conductivity is poor (E [pt

  11. Atmospheric Entry Experiments at IRS

    Science.gov (United States)

    Auweter-Kurtz, M.; Endlich, P.; Herdrich, G.; Kurtz, H.; Laux, T.; Löhle, S.; Nazina, N.; Pidan, S.

    2002-01-01

    Entering the atmosphere of celestial bodies, spacecrafts encounter gases at velocities of several km/s, thereby being subjected to great heat loads. The thermal protection systems and the environment (plasma) have to be investigated by means of computational and ground facility based simulations. For more than a decade, plasma wind tunnels at IRS have been used for the investigation of TPS materials. Nevertheless, ground tests and computer simulations cannot re- place space flights completely. Particularly, entry mission phases encounter challenging problems, such as hypersonic aerothermodynamics. Concerning the TPS, radiation-cooled materials used for reuseable spacecrafts and ablator tech- nologies are of importance. Besides the mentioned technologies, there is the goal to manage guidance navigation, con- trol, landing technology and inflatable technologies such as ballutes that aim to keep vehicles in the atmosphere without landing. The requirement to save mass and energy for planned interplanetary missions such as Mars Society Balloon Mission, Mars Sample Return Mission, Mars Express or Venus Sample Return mission led to the need for manoeuvres like aerocapture, aero-breaking and hyperbolic entries. All three are characterized by very high kinetic vehicle energies to be dissipated by the manoeuvre. In this field flight data are rare. The importance of these manoeuvres and the need to increase the knowledge of required TPS designs and behavior during such mission phases point out the need of flight experiments. As result of the experience within the plasma diagnostic tool development and the plasma wind tunnel data base, flight experiments like the PYrometric RE-entry EXperiment PYREX were developed, fully qualified and successfully flown. Flight experiments such as the entry spectrometer RESPECT and PYREX on HOPE-X are in the conceptual phase. To increase knowledge in the scope of atmospheric manoeuvres and entries, data bases have to be created combining both

  12. Innovation and optimization of a method of pump-probe polarimetry with pulsed laser beams in view of a precise measurement of parity violation in atomic cesium; Innovation et optimisation d'une methode de polarimetrie pompe-sonde avec des faisceaux laser impulsionnels en vue d'une mesure precise de violation de la parite dans l'atome de cesium

    Energy Technology Data Exchange (ETDEWEB)

    Chauvat, D

    1997-10-15

    While Parity Violation (PV) experiments on highly forbidden transitions have been using detection of fluorescence signals; our experiment uses a pump-probe scheme to detect the PV signal directly on a transmitted probe beam. A pulsed laser beam of linear polarisation {epsilon}{sub 1} excites the atoms on the 6S-7S cesium transition in a colinear electric field E || k(ex). The probe beam (k(pr) || k(ex)) of linear polarisation {epsilon}{sub 2} tuned to the transition 7S-6P(3/2) is amplified. The small asymmetry ({approx} 10{sup -6}) in the gain that depends on the handedness of the tri-hedron (E, {epsilon}{sub 1}, {epsilon}{sub 2}) is the manifestation of the PV effect. This is measured as an E-odd apparent rotation of the plane of polarization of the probe beam; using balanced mode polarimetry. New criteria of selection have been devised, that allow us to distinguish the true PV-signal against fake rotations due to electromagnetic interferences, geometrical effects, polarization imperfections, or stray transverse electric and magnetic fields. These selection criteria exploit the symmetry of the PV-rotation - linear dichroism - and the revolution symmetry of the experiment. Using these criteria it is not only possible to reject fake signals, but also to elucidate the underlying physical mechanisms and to measure the relevant defects of the apparatus. The present signal-to-noise ratio allows embarking in PV measurements to reach the 10% statistical accuracy. A 1% measurement still requires improvements. Two methods have been demonstrated. The first one exploits the amplification of the asymmetry at high gain - one major advantage provided by our detection method based on stimulated emission. The second method uses both a much higher incident intensity and a special dichroic component which magnifies tiny polarization rotations. (author)

  13. High performance polarization-independent Quantum Dot Semiconductor Optical Amplifier with 22 dB fiber to fiber gain using Mode Propagation Tuning without additional polarization controller

    Science.gov (United States)

    Farmani, Ali; Farhang, Mahmoud; Sheikhi, Mohammad H.

    2017-08-01

    A detailed numerical investigation of polarization-independent quantum dot InAs/GaAs semiconductor optical amplifier (PIQS) based on a technique called mode propagation tuning (MPT) without the need for the polarization controller (PC) is reported, which can solve the limitation caused by polarization sensitivity in a semiconductor optical amplifier (SOA). Our calculations show that by a suitable tuning of the thickness of the active layer, only the TE0 and TM0 modes can propagate. Moreover, the gain saturation behavior of this SOA was measured at 1.55 μ m and found to be polarization-independent (PI). At active layer thickness of 1.7 μ m, the confinement factor was 0.75 and 0.7 for TE0 and TM0 modes, respectively, which leads to a gain difference up to 0.1 dB. The rate equations of the QD-SOA were also solved and a fiber to fiber gain of 22 dB was obtained. Additionally, a numerical simulation is presented which shows that the residual gain ripple and polarization sensitivity are sufficiently reduced when residual facet reflectivities of the SOA are in the range below 10-4 . In addition, the full-width at half-maximum of the horizontal and vertical far-field patterns (FFPs) are measured as 30° × 30°. The proposed structure can be used for logical applications.

  14. Teaching IR to Medical Students: A Call to Action.

    Science.gov (United States)

    Lee, Aoife M; Lee, Michael J

    2018-02-01

    Interventional radiology (IR) has grown rapidly over the last 20 years and is now an essential component of modern medicine. Despite IR's increasing penetration and reputation in healthcare systems, IR is poorly taught, if taught at all, in most medical schools. Medical students are the referrers of tomorrow and potential IR recruits and deserve to be taught IR by expert IRs. The lack of formal IR teaching curricula in many medical schools needs to be addressed urgently for the continued development and dissemination of, particularly acute, IR services throughout Europe. We call on IRs to take up the baton to teach IR to the next generation of doctors.

  15. Premier's imaging IR limb sounder

    Science.gov (United States)

    Kraft, Stefan; Bézy, Jean-Loup; Meynart, Roland; Langen, Jörg; Carnicero Dominguez, Bernardo; Bensi, Paolo; Silvestrin, Pierluigi

    2017-11-01

    The Imaging IR Limb Sounder (IRLS) is one of the two instruments planned on board of the candidate Earth Explorer Core Mission PREMIER. PREMIER stands for PRocess Exploration through Measurements of Infrared and Millimetre-wave Emitted Radiation. PREMIER went recently through the process of a feasibility study (Phase A) within the Earth Observation Envelope Program. Emerging from recent advanced instrument technologies IRLS shall, next to a millimetre-wave limb sounder (called STEAMR), explore the benefits of three-dimensional limb sounding with embedded cloud imaging capability. Such 3D imaging technology is expected to open a new era of limb sounding that will allow detailed studies of the link between atmospheric composition and climate, since it will map simultaneously fields of temperature and many trace gases in the mid/upper troposphere and stratosphere across a large vertical and horizontal field of view and with high vertical and horizontal resolution. PREMIER shall fly in a tandem formation looking backwards to METOP's swath and thereby improve meteorological and environmental analyses.

  16. Atom condensation on an atomically smooth surface: Ir, Re, W, and Pd on Ir(111)

    International Nuclear Information System (INIS)

    Wang, S.C.; Ehrlich, G.

    1991-01-01

    The distribution of condensing metal atoms over the two types of sites present on an atomically smooth Ir(111) has been measured in a field ion microscope. For Ir, Re, W, and Pd from a thermal source, condensing on Ir(111) at ∼20 K, the atoms are randomly distributed, as expected if they condense at the first site struck

  17. Biochemical applications of FT-IR spectroscopy

    NARCIS (Netherlands)

    Pistorius, A.M.A.

    1996-01-01

    This thesis describes the use of (FT-)IR spectroscopy in general biochemical research. In chapter 3, IR spectroscopy is used in the quantitation of residual detergent after reconstitution of an integral membrane protein in a pre-defined lipid matrix. This chapter discusses the choice of the

  18. Status Of Sofradir IR-CCD Detectors

    Science.gov (United States)

    Tribolet, Philippe; Radisson, Patrick

    1988-05-01

    The topics of this paper deal with the IR-CCD detectors manufactured by SOFRADIR the new French joint venture. Description of the IRCCD technology and the advantages of this approach are given. In conclusion, some IR-CCD typical results are given.

  19. Visualizing Infrared (IR) Spectroscopy with Computer Animation

    Science.gov (United States)

    Abrams, Charles B.; Fine, Leonard W.

    1996-01-01

    IR Tutor, an interactive, animated infrared (IR) spectroscopy tutorial has been developed for Macintosh and IBM-compatible computers. Using unique color animation, complicated vibrational modes can be introduced to beginning students. Rules governing the appearance of IR absorption bands become obvious because the vibrational modes can be visualized. Each peak in the IR spectrum is highlighted, and the animation of the corresponding normal mode can be shown. Students can study each spectrum stepwise, or click on any individual peak to see its assignment. Important regions of each spectrum can be expanded and spectra can be overlaid for comparison. An introduction to the theory of IR spectroscopy is included, making the program a complete instructional package. Our own success in using this software for teaching and research in both academic and industrial environments will be described. IR Tutor consists of three sections: (1) The 'Introduction' is a review of basic principles of spectroscopy. (2) 'Theory' begins with the classical model of a simple diatomic molecule and is expanded to include larger molecules by introducing normal modes and group frequencies. (3) 'Interpretation' is the heart of the tutorial. Thirteen IR spectra are analyzed in detail, covering the most important functional groups. This section features color animation of each normal mode, full interactivity, overlay of related spectra, and expansion of important regions. This section can also be used as a reference.

  20. PKCδ-mediated IRS-1 Ser24 phosphorylation negatively regulates IRS-1 function

    International Nuclear Information System (INIS)

    Greene, Michael W.; Ruhoff, Mary S.; Roth, Richard A.; Kim, Jeong-a; Quon, Michael J.; Krause, Jean A.

    2006-01-01

    The IRS-1 PH and PTB domains are essential for insulin-stimulated IRS-1 Tyr phosphorylation and insulin signaling, while Ser/Thr phosphorylation of IRS-1 disrupts these signaling events. To investigate consensus PKC phosphorylation sites in the PH-PTB domains of human IRS-1, we changed Ser24, Ser58, and Thr191 to Ala (3A) or Glu (3E), to block or mimic phosphorylation, respectively. The 3A mutant abrogated the inhibitory effect of PKCδ on insulin-stimulated IRS-1 Tyr phosphorylation, while reductions in insulin-stimulated IRS-1 Tyr phosphorylation, cellular proliferation, and Akt activation were observed with the 3E mutant. When single Glu mutants were tested, the Ser24 to Glu mutant had the greatest inhibitory effect on insulin-stimulated IRS-1 Tyr phosphorylation. PKCδ-mediated IRS-1 Ser24 phosphorylation was confirmed in cells with PKCδ catalytic domain mutants and by an RNAi method. Mechanistic studies revealed that IRS-1 with Ala and Glu point mutations at Ser24 impaired phosphatidylinositol-4,5-bisphosphate binding. In summary, our data are consistent with the hypothesis that Ser24 is a negative regulatory phosphorylation site in IRS-1

  1. Implementing GPS into Pave-IR.

    Science.gov (United States)

    2009-03-01

    To further enhance the capabilities of the Pave-IR thermal segregation detection system developed at the Texas Transportation Institute, researchers incorporated global positioning system (GPS) data collection into the thermal profiles. This GPS capa...

  2. Joint IAEA/NEA IRS guidelines

    International Nuclear Information System (INIS)

    1997-01-01

    The Incident Reporting System (IRS) is an international system jointly operated by the International Atomic Energy Agency (IAEA) and the Nuclear Energy Agency of the Organization for Economic Cooperation and Development (OECD/NEA). The fundamental objective of the IRS is to contribute to improving the safety of commercial nuclear power plants (NPPs) which are operated worldwide. This objective can be achieved by providing timely and detailed information on both technical and human factors related to events of safety significance which occur at these plants. The purpose of these guidelines, which supersede the previous IAEA Safety Series No. 93 (Part II) and the NEA IRS guidelines, is to describe the system and to give users the necessary background and guidance to enable them to produce IRS reports meeting a high standard of quality while retaining the high efficiency of the system expected by all Member States operating nuclear power plants

  3. Novel Wavelength Standards in the Near IR

    National Research Council Canada - National Science Library

    Corwin, Kristan L

    2008-01-01

    .... This research has three major components, consisting of spectroscopy in hollow fiber, the development of a near-IR optical frequency comb with which to characterize the transitions inside the fiber...

  4. IR aperture measurement at β*=40 cm

    CERN Document Server

    Bruce, Roderik; Hermes, Pascal Dominik; Kwee-Hinzmann, Regina; Mereghetti, Alessio; Mirarchi, Daniele; Redaelli, Stefano; Salvachua Ferrando, Belen Maria; Skowronski, Piotr Krzysztof; Valentino, Gianluca; Valloni, Alessandra; CERN. Geneva. ATS Department

    2015-01-01

    This note summarizes MD 307, performed on August 27 2015, during which we measured with beam the global apertures at 6.5 TeV with IR1 and IR5 squeezed to β* =40 cm and a half crossing angle of 205 rad. The measurement technique involved opening collimators in steps, while inducing beam losses at each step, until the main loss location moved from the collimators to the global bottleneck in one of the triplets. Measurements were performed in both beams and planes, and each measurement gave the minimum triplet aperture over IR1 and IR5. The results are in very good agreement with theoretical predictions. At the end of the MD, an asynchronous beam dump test was performed with all collimators moved in to so-called 2-σ retraction settings. This MD is one in a series meant to address various open points for the reach in β* in Run II.

  5. Activity uniformity of Ir-192 seeds

    International Nuclear Information System (INIS)

    Ling, C.C.; Gromadzki, Z.C.

    1981-01-01

    A simple device that uses materials and apparatus commonly available in a radiotherapy department has been designed, fabricated and used in routine quality control relative to the activity uniformity of clinical Ir-192 seeds in ribbons. Detailed evaluation indicated that this system is easy to use and can yield relative activity measurements of individual Ir-192 seeds accurate to within 2%. With this device, activity uniformity of commercial Ir-192 seeds from two manufacturers has been assessed. For the seven shipments of Ir-192 seeds studied, the root mean square variations of individual seed strength from the average of each shipment ranged from 3.4 to 7.1%. Variation in seed activity by more than +- 10% from the average is not uncommon

  6. Infrared (IR) remote sensing of gases

    OpenAIRE

    López Martínez, Fernando

    2008-01-01

    The IR Imaging and Remote Sensing Laboratory – LIR-UC3M of Universidad Carlos III, has developed Multi and Hyper spectral Infrared (IR) analysis techniques for gas remote sensing. Design of specific sensors for the determination of gases and their concentration are proposed. Almost all gases (CO2, CO, NO2, O3, HC o NH, …) related to industrial, environmental or military safety can be detected. Companies or centres with interest in the use of specific application sensors are required.

  7. Fabrication of flexible Ir and Ir-Rh wires and application for thermocouple

    Science.gov (United States)

    Murakami, Rikito; Kamada, Kei; Shoji, Yasuhiro; Yokota, Yuui; Yoshino, Masao; Kurosawa, Shunsuke; Ohashi, Yuji; Yamaji, Akihiro; Yoshikawa, Akira

    2018-04-01

    The fabrication and thermal electromotive force characteristics of Ir/Ir-Rh thermocouples capable of repeated bending deformation are described. Ir and Ir-Rh wires with a diameter of 0.5 mm were fabricated using the alloy-micro-pulling-down method. Scanning electron microscopy and electron backscattering diffraction of the radial cross section of the grown wires were performed to investigate the microstructure and orientation of the crystal grains. At the start of growth, the microstructure was polycrystalline with diameters of several hundred micrometers, while at the 8-m growth point it was found to be monocrystalline. The observed single crystals of pure Ir and Ir-Rh alloy were oriented in the 〈1 1 3〉 and 〈1 1 2〉 directions, respectively, whereas the polycrystalline Ir-Rh samples showed preferential growth in the 〈1 0 0〉 direction. The thermal electromotive force of the fabricated Ir/Ir-Rh thermocouple was measured by the comparison technique and the fixed-point technique, and the thermoelectric power was estimated to be 5.9 μV/°C in the range from 600°C to 1100°C.

  8. Single-nucleotide polymorphism of INS, INSR, IRS1, IRS2, PPAR-G ...

    Indian Academy of Sciences (India)

    2017-03-02

    Mar 2, 2017 ... Abstract. Polycystic ovary syndrome (PCOS) is the most common and a complex female endocrine disorder, and is one of the leading cause of female infertility. Here, we aimed to investigate the association of single-nucleotide polymorphism of INS, INSR,. IRS1, IRS2, PPAR-G and CAPN10 gene in the ...

  9. Intelligent multi-spectral IR image segmentation

    Science.gov (United States)

    Lu, Thomas; Luong, Andrew; Heim, Stephen; Patel, Maharshi; Chen, Kang; Chao, Tien-Hsin; Chow, Edward; Torres, Gilbert

    2017-05-01

    This article presents a neural network based multi-spectral image segmentation method. A neural network is trained on the selected features of both the objects and background in the longwave (LW) Infrared (IR) images. Multiple iterations of training are performed until the accuracy of the segmentation reaches satisfactory level. The segmentation boundary of the LW image is used to segment the midwave (MW) and shortwave (SW) IR images. A second neural network detects the local discontinuities and refines the accuracy of the local boundaries. This article compares the neural network based segmentation method to the Wavelet-threshold and Grab-Cut methods. Test results have shown increased accuracy and robustness of this segmentation scheme for multi-spectral IR images.

  10. Near-IR imaging and imaging polarimetry of OMC 2

    Science.gov (United States)

    Rayner, John; Mclean, Ian; Aspin, Colin; Mccaughrean, Mark

    1989-01-01

    NIR and 2.2-micron imaging polarimetry of the molecular cloud region OMC 2, reveals a cluster of low- to intermediate-mass premain-sequence stars embedded in circumstellar disks. The 2.2-micron imaging polarimetry indicates that the compact NIR sources OMC 2 IRS1, IRS2, IRS3 and IRS4 N, are illumination centers for the surrounding extended emission. By application of Hubble's relation to the nebulae illuminated by IRS1, IRS2 and IRS4 N, the illuminating geometry is explained and the intrinsic NIR colors of these objects are estimated.

  11. IR Thermometer with Automatic Emissivity Correction

    Directory of Open Access Journals (Sweden)

    A. Dobesch

    2013-12-01

    Full Text Available The paper describes the design and implementation of an infrared (IR thermometer with automatic emissivity correction. The temperature measurement is carried out by the simple digital thermopile sensor MLX90614. The emissivity correction is based on benefits of diffuse reflecting materials and it uses an IR laser diode in conjunction with a selective amplifier. Moreover, the paper includes the design of the control interface with a graphics LCD. Furthermore, this paper describes the power supply unit with a Li-ion cell controlled by basic integrated circuits.

  12. Kas netilpo tarp politikos ir diplomatijos?

    OpenAIRE

    Streikus, Arūnas

    2008-01-01

    The review analyzes A. Kasparavičius’s monograph “Tarp Politikos ir Diplomatijos: Šventasis Sostas ir Lietuvos Respublika” (Vilnius, 2008). The historiographic value of the study is undisputed. A. Kasperavičius had an opportunity to use a broad spectrum of sources, among which two sets of archive documents stand out: the funds of the archives of Ministry of Foreign Affairs of Lithuania and the Lithuanian Embassy under the Holy See in Rome. A. Kasparavičius managed to avoid the arid scientific...

  13. Elecciones Legislativas en Irán

    Directory of Open Access Journals (Sweden)

    José Antonio Sainz de la Peña

    2012-05-01

    Full Text Available Las elecciones legislativas en Irán, una vez eliminados los reformistas se han celebrado en un clima de rivalidad. Las elecciones tenían que dejar claro quién mandaba en Irán, si los clérigos y el Guía el ayatolá Seyed Ali Jamenei o, el Presidente de la República, el laico Mahmud Ahmadineyad, apoyado en el Cuerpo de Guardias Revolucionarios. La realidad ha sido que las facciones conservadoras encabezadas por el Frente Unido Principalista, apoyados por el Guía Supremo, han obtenido el triunfo.

  14. Isolated Gramicidin Peptides Probed by IR Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Rijs, A. M.; Kabeláč, Martin; Abo-Riziq, A.; Hobza, Pavel; de Vries, M. S.

    2011-01-01

    Roč. 12, č. 10 (2011), s. 1816-1821 ISSN 1439-4235 R&D Projects: GA MŠk LC512; GA AV ČR IAA400550808 Institutional research plan: CEZ:AV0Z40550506 Keywords : density functional calculations * gramicidin * IR spectroscopy * protein folding Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.412, year: 2011

  15. IR and OLAP in XML document warehouses

    DEFF Research Database (Denmark)

    Perez, Juan Manuel; Pedersen, Torben Bach; Berlanga, Rafael

    2005-01-01

    In this paper we propose to combine IR and OLAP (On-Line Analytical Processing) technologies to exploit a warehouse of text-rich XML documents. In the system we plan to develop, a multidimensional implementation of a relevance modeling document model will be used for interactively querying...

  16. Column Stores as an IR Prototyping Tool

    NARCIS (Netherlands)

    H.F. Mühleisen (Hannes); T. Samar (Thaer); J.J.P. Lin (Jimmy); A.P. de Vries (Arjen)

    2014-01-01

    textabstract. We make the suggestion that instead of implementing custom index structures and query evaluation algorithms, IR researchers should simply store document representations in a column-oriented relational database and write ranking models using SQL. For rapid prototyping, this is

  17. TIJAH: embracing IR methods in XML databases

    NARCIS (Netherlands)

    J.A. List; V. Mihajlovic; G. Ramirez Camps (Georgina); A.P. de Vries (Arjen); D. Hiemstra; H.E. Blok

    2005-01-01

    textabstractThis paper discusses our participation in INEX (the Initiative for the Evaluation of XML Retrieval) using the TIJAH XML-IR system. TIJAH's system design follows a `standard' layered database architecture, carefully separating the conceptual, logical and physical levels. At the conceptual

  18. Metal-Mesh Optical Filter Technology for Mid IR, Far IR, and Submillimeter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a method of fabrication of far IR and THZ range multilayer metal-mesh filters. This type of filter consists of alternative...

  19. Metal-Mesh Optical Filter Technology for Mid IR, Far IR, and Submillimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovative, high transmission band-pass filter technology proposed here is an improvement in multilayer metal-mesh filter design and manufacture for the far IR...

  20. Metal-Mesh Optical Filter Technology for Mid IR, Far IR, and Submillimeter, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovative, high transmission band-pass filter technology proposed here is an improvement in multilayer metal-mesh filter design and manufacture for the far IR...

  1. Suppression of superconductivity in Nb by IrMn in IrMn/Nb bilayers

    KAUST Repository

    Wu, B. L.

    2013-10-10

    Effect of antiferromagnet on superconductivity has been investigated in IrMn/Nb bilayers. Significant suppression of both transition temperature (Tc) and lower critical field (Hc1) of Nb is found in IrMn/Nb bilayers as compared to a single layer Nb of same thickness; the suppression effect is even stronger than that of a ferromagnet in NiFe/Nb bilayers. The addition of an insulating MgO layer at the IrMn-Nb interface nearly restores Tc to that of the single layer Nb, but Hc1 still remains suppressed. These results suggest that, in addition to proximity effect and magnetic impurity scattering, magnetostatic interaction also plays a role in suppressing superconductivity of Nb in IrMn/Nb bilayers. In addition to reduced Tc and Hc1, the IrMn layer also induces broadening in the transition temperature of Nb, which can be accounted for by a finite distribution of stray field from IrMn.

  2. Infrared Measurements of Possible IR Filter Materials

    Energy Technology Data Exchange (ETDEWEB)

    Koller,D.; Ediss, G.; Mihaly, L.; Carr, G.

    2006-01-01

    A Fourier Transform Infrared Spectrometer (FTS) was used to obtain the transmission spectra of candidate materials for use as infrared (IR) filters in cryogenic receivers. The data cover the range from 50 cm-1 ({approx}1.5 THz), well below the peak of the 300 K black body spectrum, to 5000 cm-1 ({approx}150 THz), Z-cut quartz, Gore-Tex, Zitex G and Zitex A, High Density Polyethylene (HDPE), Teflon (PTFE), Fluorogold and Black Polyethylene were measured. The relative effectiveness of each material as a filter is determined by integrating the transmission spectrum multiplied by the Planck distribution to obtain a normalized attenuation for the mid-IR band. Measurements at both room temperature and 8 K are compared.

  3. Development of pixellated Ir-TESs

    International Nuclear Information System (INIS)

    Zen, Nobuyuki; Takahashi, Hiroyuki; Kunieda, Yuichi; Dayanthi, Rathnayaka M.T.; Mori, Fumiakira; Fujita, Kaoru; Nakazawa, Masaharu; Fukuda, Daiji; Ohkubo, Masataka

    2006-01-01

    We have been developing Ir-based pixellated superconducting transition edge sensors (TESs). In the area of material or astronomical applications, the sensor with few eV energy resolution and over 1000 pixels imaging property is desired. In order to achieve this goal, we have been analyzing signals from pixellated TESs. In the case of a 20 pixel array of Ir-TESs, with 45 μmx45 μm pixel sizes, the incident X-ray signals have been classified into 16 groups. We have applied numerical signal analysis. On the one hand, the energy resolution of our pixellated TES is strongly degraded. However, using pulse shape analysis, we can dramatically improve the resolution. Thus, we consider that the pulse signal analysis will lead this device to be used as a practical photon incident position identifying TES

  4. Advances in handheld FT-IR instrumentation

    Science.gov (United States)

    Arnó, Josep; Cardillo, Len; Judge, Kevin; Frayer, Maxim; Frunzi, Michael; Hetherington, Paul; Levy, Dustin; Oberndorfer, Kyle; Perec, Walter; Sauer, Terry; Stein, John; Zuidema, Eric

    2012-06-01

    FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenges of ConOps (Concepts of Operation) in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the advances resulting from a project designed to overcome the challenges associated with miniaturizing FT-IR instruments. The project team developed a disturbance-corrected permanently aligned cube corner interferometer for improved robustness and optimized opto-mechanical design to maximize optical throughput and signal-to-noise ratios. Thermal management and heat flow were thoroughly modeled and studied to isolate sensitive components from heat sources and provide the widest temperature operation range. Similarly, extensive research on mechanical designs and compensation techniques to protect against shock and vibration will be discussed. A user interface was carefully created for military and emergency response applications to provide actionable information in a visual, intuitive format. Similar to the HazMatID family of products, state-of-the-art algorithms were used to quickly identify the chemical composition of complex samples based on the spectral information. This article includes an overview of the design considerations, tests results, and performance validation of the mechanical ruggedness, spectral, and thermal performance.

  5. Supplemental Security Income (SSI) / Internal Revenue Service (IRS) 1099

    Data.gov (United States)

    Social Security Administration — A finder file from SSA's Title XVI database is provided to the IRS. The IRS discloses 1099 information to SSA for use in verifying eligibility, amount, and benefits...

  6. ODYSSEY THEMIS IR PBT V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The THEMIS IR-PBT data set contains the spatially registered, infrared brightness temperature images derived from the projected radiance (IR-GEO) products. Each...

  7. Acquisition of Infrared Variable Angle Spectroscopic Ellipsometer (IR-VASE)

    Science.gov (United States)

    2016-04-22

    SECURITY CLASSIFICATION OF: This award was used to acquire a J.A. Woollam Infrared Variable Angle Spectroscopic Ellipsometer ( IR -VASE). The IR -VASE...unit is capable of obtaining crucial IR information of ultrathin films whilst being complemented with ellipsometry data. This powerful and versatile...Unlimited UU UU UU UU 22-04-2016 1-Feb-2015 31-Jan-2016 Final Report: Acquisition of Infrared Variable Angle Spectroscopic Ellipsometer ( IR -VASE) The

  8. IR Cards: Inquiry-Based Introduction to Infrared Spectroscopy

    Science.gov (United States)

    Bennett, Jacqueline; Forster, Tabetha

    2010-01-01

    As infrared spectroscopy (IR) is frequently used in undergraduate organic chemistry courses, an inductive introduction to IR spectroscopy that uses index cards printed with spectra, structures, and chemical names is described. Groups of students are given an alphabetized deck of these "IR cards" to sort into functional groups. The students then…

  9. IGF-IR targeted therapy: Past, present and future

    NARCIS (Netherlands)

    J.A.M.J.L. Janssen (Joseph); A.J. Varewijck (Aimee)

    2014-01-01

    textabstractThe IGF-I receptor (IGF-IR) has been studied as an anti-cancer target. However, monotherapy trials with IGF-IR targeted antibodies or with IGF-IR specific tyrosine kinase inhibitors have, overall, been very disappointing in the clinical setting. This review discusses potential reasons

  10. Comparison of simple and chelated amberlite IR-120 for ...

    African Journals Online (AJOL)

    In the present study, the efficiency of simple and chelating Amberlite IR-120 with α-nitroso β-naphthol (IR-αNβN) and with 8-hydroxy quinoline (IR-8HQ) has been compared for the removal of Cu(II) from aqueous solutions. The chelation was confirmed using different characterization techniques like SEM, TGA and FTIR.

  11. Infrared upconversion spectrometer for the mid-ir range

    DEFF Research Database (Denmark)

    2018-01-01

    The invention provides an infrared upconversion spectrometer for determining a mid-IR spectrum of received infrared light with a high resolution. The spectrometer applies upconversion to transform light in the mid-IR to the near-IR range where efficient detectors are available. The upconversion...

  12. X-ray magnetic circular dichroism at IrL 2,3 edges in Fe 100- Ir

    Indian Academy of Sciences (India)

    3, 10 and 17) and Co100-Ir (=5, 17, 25 and 32) alloys has been investigated by X-ray magnetic circular dichroism (XMCD) at Ir L2,3 absorption edges. Sum rule analysis of the XMCD data show that the orbital moment of Ir is in the range of ...

  13. IR Spectroscopic signs of malignant neoplasms in the thyroid gland

    Science.gov (United States)

    Tolstorozhev, G. B.; Skornyakov, I. V.; Butra, V. A.

    2012-03-01

    We use Fourier transform IR spectroscopy to study thyroid tumor tissues which were removed during surgery. The IR spectra of the tissues with pathological foci are compared with data from histologic examination. In the region of N-H, C-H, and C = O stretching vibrations, the IR spectra of the tissues for thyroid cancer are different from the IR spectra of tissues without malignant formations. We identify the spectral signs of thyroid cancer. We show that IR analysis is promising for identification of thyroid pathology at the molecular level.

  14. Defense Strategy of Aircraft Confronted with IR Guided Missile

    OpenAIRE

    Huang, Hesong; Tong, Zhongxiang; Li, Taorui; Jia, Lintong; Li, Shenbo

    2017-01-01

    Surface-type infrared (IR) decoy can simulate the IR characteristics of the target aircraft, which is one of the most effective equipment to confront IR guided missile. In the air combat, the IR guided missile poses a serious threat to the aircraft when it comes from the front of target aircraft. In this paper, firstly, the model of aircraft and surface-type IR decoy is established. To ensure their authenticity, the aircraft maneuver and radiation models based on real data of flight and exhau...

  15. IR and OLAP in XML document warehouses

    DEFF Research Database (Denmark)

    Perez, Juan Manuel; Pedersen, Torben Bach; Berlanga, Rafael

    2005-01-01

    In this paper we propose to combine IR and OLAP (On-Line Analytical Processing) technologies to exploit a warehouse of text-rich XML documents. In the system we plan to develop, a multidimensional implementation of a relevance modeling document model will be used for interactively querying...... the warehouse by allowing navigation in the structure of documents and in a concept hierarchy of query terms. The facts described in the relevant documents will be ranked and analyzed in a novel OLAP cube model able to represent and manage facts with relevance indexes....

  16. The Near-IR Extinction Law

    Science.gov (United States)

    Stead, Joseph J.; Hoare, Melvin G.

    2010-11-01

    We show that the power-law slope of the near-IR extinction law is significantly steeper than previously thought. Simulated colour-colour diagrams including a stellar population synthesis, realistic extinction distribution along the line-of-sight and synthesis through the filter profiles are compared to data from the UKIDSS Galactic Plane Survey. The slope of extinction with wavelength is found to be 2.14 ± 0.05 for total visual extinctions up to about 25 magnitudes and for a number of locations.

  17. Controlling Hydrogenation of Graphene on Ir(111)

    DEFF Research Database (Denmark)

    Balog, Richard; Andersen, Mie; Jørgensen, Bjarke

    2013-01-01

    Combined fast X-ray photoelectron spectroscopy and density functional theory calculations reveal the presence of two types of hydrogen adsorbate structures at the graphene/ Ir(111) interface, namely, graphane-like islands and hydrogen dimer structures. While the former give rise to a periodic...... pattern, dimers tend to destroy the periodicity. Our data reveal distinctive growth rates and stability of both types of structures, thereby allowing one to obtain well-defined patterns of hydrogen clusters. The ability to control and manipulate the formation and size of hydrogen structures on graphene...... facilitates tailoring of its properties for a wide range of applications by means of covalent functionalization....

  18. Fast IR diodes thermometer for tokamak

    International Nuclear Information System (INIS)

    Chen Xiangbo

    2001-01-01

    A 30 channel fast IR pyrometry array has been constructed for tokamak, which has 0.5 μs time response, 10 mm diameter spatial resolution and 5 degree C temperature resolution. The temperature measuring range is from 250 degree C to 1200 degree C. The two dimensional temperature profiles of the first wall during both major and minor disruptions can be measured with an accuracy of about 1% measuring temperature, which is adequate for tokamak experiments. This gives a very useful tool for the disruption study, especially for the divertor physics and edge heat flux research on tokamak and other magnetic confinement devices

  19. Atsiskaitymai e. versle: ypatumai ir naujos tendencijos

    OpenAIRE

    Vyšniauskas, Jonas

    2014-01-01

    Alternatyvių atsiskaitymų e. versle sistemos pradeda kelti rimtą grėsmę tradiciniams atsiskaitymams elektronine bankininkyste, mokėjimo kortelėmis ar grynaisiais pinigais. Todėl būtina detaliau išsiaiškinti kokie yra alternatyvių atsiskaitymų ypatumai, kurie veiksniai vartotojams yra svarbiausi ir kokie yra alternatyvūs atsiskaitymo būdai. Tai siekiama padaryti išanalizuojant mokslinę literatūrą, pateikiant pagrindines alternatyvių atsiskaitymų sistemas, atliekant alternatyvių atsiskaitymų pa...

  20. An IR Navigation System for Pleural PDT

    Directory of Open Access Journals (Sweden)

    Timothy C Zhu

    2015-03-01

    Full Text Available Pleural photodynamic therapy (PDT has been used as an adjuvant treatment with lung-sparing surgical treatment for malignant pleural mesothelioma (MPM. In the current pleural PDT protocol, a moving fiber-based point source is used to deliver the light. The light fluences at multiple locations are monitored by several isotropic detectors placed in the pleural cavity. To improve the delivery of light fluence uniformity, an infrared (IR navigation system is used to track the motion of the light source in real-time at a rate of 20 - 60 Hz. A treatment planning system uses the laser source positions obtained from the IR camera to calculate light fluence distribution to monitor the light dose uniformity on the surface of the pleural cavity. A novel reconstruction algorithm is used to determine the pleural cavity surface contour. A dual-correction method is used to match the calculated fluences at detector locations to the detector readings. Preliminary data from a phantom shows superior light uniformity using this method. Light fluence uniformity from patient treatments is also shown with and without the correction method.

  1. Perception range prediction for IR pilot sight

    Science.gov (United States)

    Weiss, A. Robert; Großmann, Peter; Repasi, Endre; Ritt, Gunnar; Wittenstein, Wolfgang

    2008-04-01

    The increasing use of IR pilot sight in helicopters calls for a reliable prediction of perception ranges for a variety of objects, especially those needed for orientation and those posing as a potential hazard, like power poles, masts, isolated trees etc. Since the visibility of objects in the IR depends mainly on the temperature differences between those objects and a given background and only marginally on illumination, range prediction techniques used for the visual range or light-amplified vision are only of very limited use. While range predictions based on the Johnson criterion do offer some insight into expected ranges, the inherently nominal nature of distance estimates thus obtained hampers their use for an actual field-deployable pre-flight consulting procedure. In order to overcome those limitations, long-term simultaneous measurements of relevant objects and background temperatures and weather data were carried out and used for temperature prediction from prevalent weather conditions. Together with a perception model derived from extensive observer experiments based on synthetic images of the UH Tiger Pilot Sight Unit we developed a perception range prediction package which is currently evaluated by the weather service of the Bundeswehr. We will present results from the observer experiments together with the derived perception models. These are then compared to actual perception ranges as obtained from flight experiments.

  2. Enhancing image quality produced by IR cameras

    Science.gov (United States)

    Dulski, R.; Powalisz, P.; Kastek, M.; Trzaskawka, P.

    2010-10-01

    Images produced by IR cameras are a specific source of information. The perception and interpretation of such image greatly depends on thermal properties of observed object and surrounding scenery. In practice, the optimal settings of the camera as well as automatic temperature range control do not guarantee the displayed images is optimal from observer's point of view. The solution to this could be the methods and algorithms of digital image processing implemented in the camera. Such solution should provide intelligent, dynamic contrast control applied not only across entire image but also selectively to specific areas in order to maintain optimal visualization of observed scenery. The paper discusses problems dealing with improvement of the visibility of low-contrast objects and presents method of image enhancement. The algorithm is based on adaptive histogram equalization. The image enhancement algorithm was tested on real IR images. The algorithm significantly improves the image quality and the effectiveness of object detection for the majority of thermal images. Due to its adaptive nature it should be effective for any given thermal image. The application of such algorithm is promising alternative to more expensive opto-electronic components like improved optics and detectors.

  3. Stable states in a strong IR field

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2015-05-01

    It is found that 10% of atoms stay in the quasi-stable states after being exposed to intense laser or microwave (MW) pulses, even though the pulses' intensity is much stronger than that needed for static fields ionization. The reason why atoms survive those strong pulses has attracted growing attentions. A. Arakelyan et al. have observed the optical spectra of the surviving Lithium atoms after interaction with intense 38-GHz MW fields for more than 1000 cycles, and the spectra exhibit a periodic train of peaks 38 GHz apart. It suggests that those weakly bound Rydberg electrons seldom go back to the ionic core, where the cycle average energy exchange happens. In this study, we are interested in the electron behavior in the presence of intense infrared fields with a much shorter wavelength (1000 nm). By solving the full 3D time dependent Schrodinger equation, we calculate the spectra of the surviving atoms under intense IR fields. Our numerical calculations show atoms survive the intense field in quasi-stable states for a long time, and the optical spectra are obviously modulated by the IR frequency. Through tuning the ponderomotive energy, we see how field parameters affect the behavior of electrons. Different atoms, such as Hydrogen, Helium, Lithium, and Sodium, are tested to see how atom's energy structures influence the results.

  4. Qualification tests for 192Ir sealed sources

    Science.gov (United States)

    Iancso, Georgeta; Iliescu, Elena; Iancu, Rodica

    2013-12-01

    This paper describes the results of qualification tests for 192Ir sealed sources, available in Testing and Nuclear Expertise Laboratory of National Institute for Physics and Nuclear Engineering "Horia Hulubei" (I.F.I.N.-HH), Romania. These sources had to be produced in I.F.I.N.-HH and were tested in order to obtain the authorization from The National Commission for Nuclear Activities Control (CNCAN). The sources are used for gammagraphy procedures or in gammadefectoscopy equipments. Tests, measurement methods and equipments used, comply with CNCAN, AIEA and International Quality Standards and regulations. The qualification tests are: 1. Radiological tests and measurements: dose equivalent rate at 1 m; tightness; dose equivalent rate at the surface of the transport and storage container; external unfixed contamination of the container surface. 2. Mechanical and climatic tests: thermal shock; external pressure; mechanic shock; vibrations; boring; thermal conditions for storage and transportation. Passing all tests, it was obtained the Radiological Security Authorization for producing the 192Ir sealed sources. Now IFIN-HH can meet many demands for this sealed sources, as the only manufacturer in Romania.

  5. Wafer level test solutions for IR sensors

    Science.gov (United States)

    Giessmann, Sebastian; Werner, Frank-Michael

    2014-05-01

    Wafer probers provide an established platform for performing electrical measurements at wafer level for CMOS and similar process technologies. For testing IR sensors, the requirements are beyond the standard prober capabilities. This presentation will give an overview about state of the art IR sensor probing systems reaching from flexible engineering solutions to automated production needs. Cooled sensors typically need to be tested at a target temperature below 80 K. Not only is the device temperature important but also the surrounding environment is required to prevent background radiation from reaching the device under test. To achieve that, a cryogenic shield is protecting the movable chuck. By operating that shield to attract residual gases inside the chamber, a completely contamination-free test environment can be guaranteed. The use of special black coatings are furthermore supporting the removal of stray light. Typically, probe card needles are operating at ambient (room) temperature when connecting to the wafer. To avoid the entrance of heat, which can result in distorted measurements, the probe card is fully embedded into the cryogenic shield. A shutter system, located above the probe field, is designed to switch between the microscope view to align the sensor under the needles and the test relevant setup. This includes a completely closed position to take dark current measurements. Another position holds a possible filter glass with the required aperture opening. The necessary infrared sources to stimulate the device are located above.

  6. Plasma thruster development program at the IRS

    Science.gov (United States)

    Auweter-Kurtz, Monika

    Since the early eighties the development of plasma thrusters has been an important research topic at the IRS, where a broad spectrum of stationary plasma thrusters has been investigated experimentally as well as theoretically. High power MPD thrusters (50 kW-1 MW) and a wide range of thermal arcjets (0.5-150 kW) are developed under contracts with ESA, NASA, USAF, USNAVY and with German funding. The IRS has excellent installations for continuous tests of high power accelerators. The high current power supply is a current regulated d.c. thyristor rectifier of 6 MW. The maximum current is 48 kA with a ripple less than 1%. The vacuum system is a roots pump system consisting of four stages with a total suction power of about 250,000 m 3/h at 1 Pa. Eight vacuum tanks of different sizes are connected to this system; six of them are used for plasma thruster development and two serve as plasma wind tunnels. For low power arcjet development and basic cathode erosion experiments four additional independent test stands are available.

  7. Irène Jacob visits CERN

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    French actress Irène Jacob, the daughter of physicist Maurice Jacob, visited the ATLAS and CMS control rooms on Monday 17 May together with Italian theatre actor-director Pippo Delbono, in search of inspiration for a short film. The film will be screened at the “nuit des particules” event accompanying this year’s ICHEP.   Pippo Delbono et Irène Jacob discussing their project. “La nuit des particules” (night of the particles) is an event open to the general public that is being organised for the evening of Tuesday, 27 July, to accompany the 35th International Conference on High Energy Physics (ICHEP). ICHEP is a major highlight in every physicist’s calendar, and this year’s edition is being held in Paris from 22 to 28 July. The short film will be screened during the evening, which will include a lecture and a show at the legendary Parisian cinema Le Grand Rex, with a colossal seating capacity of 2 700 spe...

  8. An IR Navigation System for Pleural PDT

    Science.gov (United States)

    Zhu, Timothy; Liang, Xing; Kim, Michele; Finlay, Jarod; Dimofte, Andreea; Rodriguez, Carmen; Simone, Charles; Friedberg, Joseph; Cengel, Keith

    2015-03-01

    Pleural photodynamic therapy (PDT) has been used as an adjuvant treatment with lung-sparing surgical treatment for malignant pleural mesothelioma (MPM). In the current pleural PDT protocol, a moving fiber-based point source is used to deliver the light. The light fluences at multiple locations are monitored by several isotropic detectors placed in the pleural cavity. To improve the delivery of light fluence uniformity, an infrared (IR) navigation system is used to track the motion of the light source in real-time at a rate of 20 - 60 Hz. A treatment planning system uses the laser source positions obtained from the IR camera to calculate light fluence distribution to monitor the light dose uniformity on the surface of the pleural cavity. A novel reconstruction algorithm is used to determine the pleural cavity surface contour. A dual-correction method is used to match the calculated fluences at detector locations to the detector readings. Preliminary data from a phantom shows superior light uniformity using this method. Light fluence uniformity from patient treatments is also shown with and without the correction method.

  9. HOMA1-IR and HOMA2-IR indexes in identifying insulin resistance and metabolic syndrome: Brazilian Metabolic Syndrome Study (BRAMS).

    Science.gov (United States)

    Geloneze, Bruno; Vasques, Ana Carolina Junqueira; Stabe, Christiane França Camargo; Pareja, José Carlos; Rosado, Lina Enriqueta Frandsen Paez de Lima; Queiroz, Elaine Cristina de; Tambascia, Marcos Antonio

    2009-03-01

    To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 90th percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. In the healthy group, HOMA-IR indexes were associated with central obesity, triglycerides and total cholesterol (p 2.7 and HOMA2-IR > 1.8; and, for MS were: HOMA1-IR > 2.3 (sensitivity: 76.8%; specificity: 66.7%) and HOMA2-IR > 1.4 (sensitivity: 79.2%; specificity: 61.2%). The cut-off values identified for HOMA1-IR and HOMA2-IR indexes have a clinical and epidemiological application for identifying IR and MS in Westernized admixtured multi-ethnic populations.

  10. Mid-IR Plasmonics, Cavity Coupled Excitations, and IR Spectra of Individual Airborne Particulate Matter

    Science.gov (United States)

    Luthra, Antriksh

    With the advances in plasmonics, new fields have evolved involving the mixing of light with various states like Surface Plasmons (SPs), Surface Phonons (SPh), molecular emitters or resonators, and wavelength scale cavities. This work concentrates on the interaction of infrared (IR) light with SPs, cavity modes, and molecular vibrations. In the first chapter, the field of Plasmonics is introduced from a classical and a quantum mechanical perspective and a comparison of both is presented. In Chapter 2, the interaction of cavity modes with vibrations is discussed. Briefly, when IR light is illuminated upon an etalon, its fringes disperse as function of angle. If there is a dielectric in a cavity having a vibrational transition in the fringe region, it leads to a strong interaction that gives rise to a Rabi splitting. Data was obtained from collaborators at the U.S. Naval Research Laboratory (NRL) and a derivation for the dispersion of etalon cavity modes was carried out to model the peak positions of the fringes. In Chapter 3, the excitation of Surface Plasmons Polaritons (SPPs) on metal bi-gratings is discussed. The resonance condition occurs when the momentum of the IR light parallel to the surface plus the grating vector match the momentum of the SPP. Experiments were performed in the GammaX space (ky=0) and the resonance peak positions were modeled with SPP momentum matching equations. In Chapter 4, the application of plasmonics in the mid-IR frequency range that overlaps with the frequencies of molecular vibrations is explored. The plasmonic mesh has interesting optical properties, it focuses more light in the holes and that leads to an enhancement of the IR spectra of a particle trapped in the mesh hole. In this work, plasmonic mesh is used to study airborne particles that are usually difficult to study using FTIR spectroscopy due to strong Mie scattering effect. Respiring dust particles of 4 microns size has significant negative health consequences. Different

  11. Electronic structure, local magnetism, and spin-orbit effects of Ir(IV)-, Ir(V)-, and Ir(VI)-based compounds

    Energy Technology Data Exchange (ETDEWEB)

    Laguna-Marco, M. A.; Kayser, P.; Alonso, J. A.; Martínez-Lope, M. J.; van Veenendaal, M.; Choi, Y.; Haskel, D.

    2015-06-01

    Element- and orbital-selective x-ray absorption and magnetic circular dichroism measurements are carried out to probe the electronic structure and magnetism of Ir 5d electronic states in double perovskite Sr2MIrO6 (M = Mg, Ca, Sc, Ti, Ni, Fe, Zn, In) and La2NiIrO6 compounds. All the studied systems present a significant influence of spin-orbit interactions in the electronic ground state. In addition, we find that the Ir 5d local magnetic moment shows different character depending on the oxidation state despite the net magnetization being similar for all the compounds. Ir carries an orbital contribution comparable to the spin contribution for Ir4+ (5d(5)) and Ir5+ (5d(4)) oxides, whereas the orbital contribution is quenched for Ir6+ (5d(3)) samples. Incorporation of a magnetic 3d atom allows getting insight into the magnetic coupling between 5d and 3d transition metals. Together with previous susceptibility and neutron diffractionmeasurements, the results indicate that Ir carries a significant local magnetic moment even in samples without a 3d metal. The size of the (small) net magnetization of these compounds is a result of predominant antiferromagnetic interactions between local moments coupled with structural details of each perovskite structure

  12. The Introduction of an Undergraduate Interventional Radiology (IR) Curriculum: Impact on Medical Student Knowledge and Interest in IR

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, M. [Bradford Royal Infirmary, Department of Radiology, Bradford Teaching Hospital Foundation Trust (United Kingdom); Shaygi, B. [Royal Devon and Exeter Hospital, Interventional Radiology Department (United Kingdom); Asadi, H., E-mail: asadi.hamed@gmail.com; Thanaratnam, P.; Pennycooke, K.; Mirza, M.; Lee, M., E-mail: mlee@rcsi.ie [Beaumont Hospital, Interventional Radiology Service, Department of Radiology (Ireland)

    2016-04-15

    IntroductionInterventional radiology (IR) plays a vital role in modern medicine, with increasing demand for services, but with a shortage of experienced interventionalists. The aim of this study was to determine the impact of a recently introduced IR curriculum on perception, knowledge, and interest of medical students regarding various aspects of IR.MethodsIn 2014, an anonymous web-based questionnaire was sent to 309 4th year medical students in a single institution within an EU country, both before and after delivery of a 10-h IR teaching curriculum.ResultsSeventy-six percent (236/309) of the respondents participated in the pre-IR module survey, while 50 % (157/309) responded to the post-IR module survey. While 62 % (147/236) of the respondents reported poor or no knowledge of IR compared to other medical disciplines in the pre-IR module survey, this decreased to 17 % (27/157) in the post-IR module survey. The correct responses regarding knowledge of selected IR procedures improved from 70 to 94 % for venous access, 78 to 99 % for uterine fibroid embolization, 75 to 97 % for GI bleeding embolization, 60 to 92 % for trauma embolization, 71 to 92 % for tumor ablation, and 81 to 94 % for angioplasty and stenting in peripheral arterial disease. With regard to knowledge of IR clinical roles, responses improved from 42 to 59 % for outpatient clinic review of patients and having inpatient beds, 63–76 % for direct patient consultation, and 43–60 % for having regular ward rounds. The number of students who would consider a career in IR increased from 60 to 73 %.ConclusionDelivering an undergraduate IR curriculum increased the knowledge and understanding of various aspects of IR and also the general enthusiasm for pursuing this specialty as a future career choice.

  13. ATF2 tests and CLIC IR study

    CERN Document Server

    Angal-Kalinin, D; Jones, J; Scarfe, A; Tygier, S

    2013-01-01

    This task covered three separate subtasks dealing with ILC and CLIC beam delivery system and Interaction region studies as well as testing the tuning procedures at ATF2 final focus test facility. The proposed local chromaticity correction final focus system for both ILC as well as CLIC is being tested experimentally for the first time at ATF2, various tuning procedures have been applied to study the applicability of various procedures to the ILC and CLIC to optimize the interaction region. The CLIC IR region was studied in detail, and the impact and mitigation of CLIC detector solenoid effects on the beam orbit, coupling and extraction have been considered. The work programme of this task concentrated on central region integration of the ILC following the design changes proposed during the technical design phase of the ILC, participation in ATF2 beam tuning studies and CLIC interaction region studies.

  14. IR-780 Loaded Phospholipid Mimicking Homopolymeric Micelles for Near-IR Imaging and Photothermal Therapy of Pancreatic Cancer.

    Science.gov (United States)

    Chen, Yangjun; Li, Zuhong; Wang, Haibo; Wang, Yin; Han, Haijie; Jin, Qiao; Ji, Jian

    2016-03-23

    IR-780 iodide, a near-infrared (near-IR) fluorescent dye, can be utilized as an effective theranostic agent for both imaging and photothermal therapy. However, its lipophilicity limits its further biomedical applications. Herein, we synthesized a phospholipid mimicking amphiphilic homopolymer poly(12-(methacryloyloxy)dodecyl phosphorylcholine) (PMDPC) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The amphiphilic homopolymer PMDPC can be self-assembled into micelles and used for the encapsulation of IR-780. The IR-780 loaded micelles (PMDPC-IR-780) exhibited low cytotoxicity in the dark, whereas remarkable photothermal cytotoxicity to pancreatic cancer cells (BxPC-3) was observed upon near-IR laser irradiation. We further investigated in vivo biodistribution of PMDPC-IR-780 micelles. Higher accumulation of PMDPC-IR-780 than that of free IR-780 in tumor tissue was verified, which might be ascribed to the enhanced permeability and retention (EPR) effect and long circulation time benefiting from the zwitterionic phosphorylcholine surface. Therefore, the IR-780 loaded phospholipid mimicking homopolymeric micelles could have great potential for cancer theranostics.

  15. Endurance test on IR rig for RI production

    International Nuclear Information System (INIS)

    Chung, Heung June; Youn, Y. J.; Han, H. S.; Hong, S. B.; Cho, Y. G.; Ryu, J. S.

    2000-12-01

    This report presents the pressure drop, vibration and endurance test results for IR rig for RI production which were desigened and fabricated by KAERI. From the pressure drop test results, it is noted that the flow rate through the IR rig corresponding to the pressure drop of 200 kPa is measured to be about 3.12 kg/sec. Vibration frequency for the IR rig ranges from 13 to 17 Hz. RMS(Root Mean Square) displacement for the IR rig is less than 30 μm, and the maximum displacement is less than 110μm. These experimental results show that the design criteria of IR rig meet the HANARO limit conditions. Endurance test results show that the appreciable fretting wear for the IR rig does not occur, however tiny trace of wear between contact points is observed

  16. Study on IR Properties of Reduced Graphene Oxide

    Science.gov (United States)

    Ma, Deyue; Li, Xiaoxia; Guo, Yuxiang; Zeng, Yurun

    2018-01-01

    Firstly, the reduced graphene oxide was prepared by modified hummer method and characterized. Then, the complex refractive index of reduced graphene oxide in IR band was tested and its IR absorption and radiation properties were researched by correlated calculation. The results show that reduced graphene oxide prepared by hummer method are multilayered graphene with defects and functional groups on its surface. Its absorption in near and far IR bands is strong, but it’s weaker in middle IR band. At the IR atmosphere Window, its normal spectral emissivity decreases with wavelength increasing, and its total normal spectral emissivity in 3 ∼ 5μm and 8 ∼ 14μm are 0.75 and 0.625, respectively. Therefore, reduced graphene oxide can be used as IR absorption and coating materials and have a great potential in microwave and infrared compatible materials.

  17. IR sensor for monitoring of burner flame; IR sensor foer oevervakning av braennarflamma

    Energy Technology Data Exchange (ETDEWEB)

    Svanberg, Marcus; Funkquist, Jonas; Clausen, Soennik; Wetterstroem, Jonas

    2007-12-15

    To obtain a smooth operation of the coal-fired power plants many power plant managers have installed online mass flow measurement of coal to all burners. This signal is used to monitor the coal mass flow to the individual burner and match it with appropriate amount of air and also to monitor the distribution of coal between the burners. The online mass flow measurement system is very expensive (approximately 150 kEUR for ten burners) and is not beneficial for smaller plants. The accuracy of the measurement and the sample frequency are also questionable. The idea in this project has been to evaluate a cheaper system that can present the same information and may also provide better accuracy and faster sample frequency. The infrared sensor is a cheap narrow banded light emission sensor that can be placed in a water cooed probe. The sensor was directed at the burner flame and the emitted light was monitored. Through calibration the mass flow of coal can be presented. Two measurement campaigns were performed. Both campaigns were carried out in Nordjyllandsverket in Denmark even though the second campaign was planned to be in Uppsala. Due to severe problems in the Uppsala plant the campaign was moved to Nordjyllandsverket. The pre-requisites for the test plant were that online measurement of coal flow was installed. In Nordjyllandsverket 4 out of 16 burners have the mass flow measurement installed. Risoe Laboratories has vast experiences in the IR technology and they provided the IR sensing equipment. One IR sensor was placed in the flame guard position just behind the flame directed towards the ignition zone. A second sensor was placed at the boiler wall directed towards the flame. The boiler wall position did not give any results and the location was not used during the second campaign. The flame-guard-positioned-sensor- signal was thoroughly evaluated and the results show that there is a clear correlation between the coal mass flow and the IR sensor signal. Tests were

  18. The pump-probe coupling of matter wave packets to remote lattice states

    DEFF Research Database (Denmark)

    Sherson, Jacob F; Park, Sung Jong; Pedersen, Poul Lindholm

    2012-01-01

    containing a Bose–Einstein condensate. The evolution of these wave packets is monitored in situ and their six-photon reflection at a band gap is observed. In direct analogy with pump–probe spectroscopy, a probe pulse allows for the resonant de-excitation of the wave packet into states localized around...... selected lattice sites at a long, controllable distance of more than 100 lattice sites from the main component. This precise control mechanism for ultra-cold atoms thus enables controlled quantum state preparation and splitting for quantum dynamics, metrology and simulation....

  19. Patterning effects in quantum dot amplifiers characterized through pump probe spectroscopy using two pump pulses

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Poel, Mike van der; Laemmlin, M.

    2004-01-01

    Patterning effects at ultrahigh bitrates in quantum dot amplifiers are investigated by a novel experimental technique. Slow carrier dynamics in the excited states and wetting layer are found to limit the potential for ultrahigh-speed signal processing....

  20. Understanding single-color multiphoton ionization spectra by pump--probe technique

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, K.; Manohar, K.G.; Bajaj, P.N.; Suri, B.M.; Talukdar, R.K.; Chakraborti, P.K.; Rao, P.R.K.

    1988-06-01

    A simple but elegant spectroscopic technique using two narrow-band dye lasers has been demonstrated for analyzing single-color resonant multi-photon-ionization spectra of atoms. This technique provides a direct identification of the starting level of the multi-photon-ionization pathway. This method can also be used to determine intermediate levels, which play an important role in the ionization process. Some typical results for uranium are presented.

  1. Mapping of wave packets in direct fragmentation via pump-probe frequency integrated fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Engel, Volker; Henriksen, Niels Engholm

    2000-01-01

    We consider femtosecond excitation of a molecule to a dissociative electronic state. The quantum dynamics is recorded via delayed excitation to a higher electronic state and measurement of the total fluorescence from this state detected as a function of delay time. It is shown that the signal can...

  2. Accessing thermo-mechanical properties of semiconductors using a pump-probe surface displacement method

    Science.gov (United States)

    González-Borrero, P. P.; Lukasievicz, G. V. B.; Zanuto, V. S.; Astrath, N. G. C.; Malacarne, L. C.

    2017-05-01

    Description of the physical mechanism leading to laser induced thermal and electronic effects in semiconductors is crucial in both basic research and technological applications. In this paper, we present a thermal mirror technique to study the thermo-mechanical properties of semiconductors. A detailed theoretical investigation is presented, and the dominant effects are described in terms of the physical properties of the material. The effect of heat coupling between the sample and the surrounding fluid was taken into account and considerations on the time and spatial approximations to the photogenerated carriers profile were used to simplify the theoretical model. These approximations were then compared to numerical models and the results hold for high recombination rate semiconductors. Experiments were performed to validate the theoretical model, and the thermal diffusivity and photogenerated heat in the sample were determined. The values obtained for these properties were found to be in good agreement with literature.

  3. Versatile ultrafast pump-probe imaging with high sensitivity CCD camera

    OpenAIRE

    Pezeril , Thomas; Klieber , Christoph; Temnov , Vasily; Huntzinger , Jean-Roch; Anane , Abdelmadjid

    2012-01-01

    International audience; A powerful imaging technique based on femtosecond time-resolved measurements with a high dynamic range, commercial CCD camera is presented. Ultrafast phenomena induced by a femtosecond laser pump are visualized through the lock-in type acquisition of images recorded by a femtosecond laser probe. This technique allows time-resolved measurements of laser excited phenomena at multiple probe wavelengths (spectrometer mode) or conventional imaging of the sample surface (ima...

  4. Ultra-short pulse laser pump-probe experiments for investigation of warm dense plasmas

    International Nuclear Information System (INIS)

    Yoneda, Hitoki; Morikami, Hidetoshi; Ueda, Ken-ichi; More, Richard M.

    2006-01-01

    We describe experiments on warm dense plasmas created with an ultra-short pulse UV laser, and probed with short pulses of various frequencies. The reflected probe pulse is analyzed to give the three Stokes' parameters which describe its elliptic polarization. From this data,-we infer the dielectric function of the warm dense plasma, taking account of its non-uniform density-temperature structure. In the experiments, we can identify an early time period when the plasma has not yet expanded significantly. In this first phase, the Fresnel formulas uniquely determine the dielectric function of hot solid-density matter from any two of the measured signals. Comparing reconstructed signals to the observed Stokes' parameters we can determine the time (usually a few 100fsec) after which surface expansion becomes important. In the second phase (t>200-300fsec), the plasma expansion is appreciable and must be modeled with analytical or numerical hydrodynamics. Comparing to experiment, we can approximately determine the plasma dielectric function. We find the free electron contribution to the dielectric function is often much less than expected from the usual Spitzer-Drude theory. Studies of dependence of probe reflection on probe laser frequency may enable us to extract the DC electrical conductivity from measured AC optical constants. New scattered-light measurements identify the onset of condensation of the expanding plasma and the formation of droplets of liquid metal

  5. New Ir Bis-Carbonyl Precursor for Water Oxidation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Daria L. [Department of Chemistry, Yale University, 225; Beltrán-Suito, Rodrigo [Department of Chemistry, Yale University, 225; Thomsen, Julianne M. [Department of Chemistry, Yale University, 225; Hashmi, Sara M. [Department of Chemical and Environmental; Materna, Kelly L. [Department of Chemistry, Yale University, 225; Sheehan, Stafford W. [Catalytic Innovations LLC, 70 Crandall; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225; Brudvig, Gary W. [Department of Chemistry, Yale University, 225; Crabtree, Robert H. [Department of Chemistry, Yale University, 225

    2016-02-05

    This paper introduces IrI(CO)2(pyalc) (pyalc = (2-pyridyl)-2-propanoate) as an atom-efficient precursor for Ir-based homogeneous oxidation catalysis. This compound was chosen to simplify analysis of the water oxidation catalyst species formed by the previously reported Cp*IrIII(pyalc)OH water oxidation precatalyst. Here, we present a comparative study on the chemical and catalytic properties of these two precursors. Previous studies show that oxidative activation of Cp*Ir-based precursors with NaIO4 results in formation of a blue IrIV species. This activation is concomitant with the loss of the placeholder Cp* ligand which oxidatively degrades to form acetic acid, iodate, and other obligatory byproducts. The activation process requires substantial amounts of primary oxidant, and the degradation products complicate analysis of the resulting IrIV species. The species formed from oxidation of the Ir(CO)2(pyalc) precursor, on the other hand, lacks these degradation products (the CO ligands are easily lost upon oxidation) which allows for more detailed examination of the resulting Ir(pyalc) active species both catalytically and spectroscopically, although complete structural analysis is still elusive. Once Ir(CO)2(pyalc) is activated, the system requires acetic acid or acetate to prevent the formation of nanoparticles. Investigation of the activated bis-carbonyl complex also suggests several Ir(pyalc) isomers may exist in solution. By 1H NMR, activated Ir(CO)2(pyalc) has fewer isomers than activated Cp*Ir complexes, allowing for advanced characterization. Future research in this direction is expected to contribute to a better structural understanding of the active species. A diol crystallization agent was needed for the structure determination of 3.

  6. Electrical and Optical Characterization System for IR Photodetectors

    Science.gov (United States)

    2015-10-12

    Electrical and Optical Characterization System for IR Photodetectors The views, opinions and/or findings contained in this report are those of the...published in non peer-reviewed journals: Final Report: Electrical and Optical Characterization System for IR Photodetectors Report Title This DURIP project...Final Report for the ARO DURIP Program Electrical and Optical Characterization System for IR Photodetectors Grant No.: W911NF-14-1-0446   Period 01

  7. Adaptive IR Sensing Based on Advanced Nanostructures with Tunable Kinetics

    Science.gov (United States)

    2015-11-05

    AFRL-AFOSR-VA-TR-2015-0360 ADAPTIVE IR SENSING BASED ON ADVANCED NANOSTRUCTURES WITH TUNABLE KINETICS Vladimir Mitin RESEARCH FOUNDATION OF STATE...1 August 2010 - 31 July 2015 4. TITLE AND SUBTITLE Adaptive IR Sensing Based on Advanced Nanostructures with Tunable Kinetics 5a. CONTRACT NUMBER...engineering, and technological basis for further development of IR nanomaterials with nanoscale potential profile that can be effectively controlled by

  8. Room temperature mid-IR single photon spectral imaging

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2012-01-01

    Spectral imaging and detection of mid-infrared (mid-IR) wavelengths are emerging as an enabling technology of great technical and scientific interest; primarily because important chemical compounds display unique and strong mid-IR spectral fingerprints revealing valuable chemical information. Whi...... 20 % for polarized incoherent light at 3 \\mum. The proposed method is relevant for existing and new mid-IR applications like gas analysis and medical diagnostics....

  9. Medicare Modernization Act (MMA) IRS Medicare Part D

    Data.gov (United States)

    Social Security Administration — SSA uses the Internal Revenue Service (IRS) information in determing the eligibility of Medicare recipients to receive subsidy payments for Medicare premiums. SSA...

  10. Role of IRS-2 in insulin and cytokine signalling.

    Science.gov (United States)

    Sun, X J; Wang, L M; Zhang, Y; Yenush, L; Myers, M G; Glasheen, E; Lane, W S; Pierce, J H; White, M F

    1995-09-14

    The protein IRS-1 acts as an interface between signalling proteins with Src-homology-2 domains (SH2 proteins) and the receptors for insulin, IGF-1, growth hormone, several interleukins (IL-4, IL-9, IL-13) and other cytokines. It regulates gene expression and stimulates mitogenesis, and appears to mediate insulin/IGF-1-stimulated glucose transport. Thus, survival of the IRS-1-/- mouse with only mild resistance to insulin was surprising. This dilemma is provisionally resolved with our discovery of a second IRS-signalling protein. We purified and cloned a likely candidate called 4PS from myeloid progenitor cells and, because of its resemblance to IRS-1, we designate it IRS-2. Alignment of the sequences of IRS-2 and IRS-1 revealed a highly conserved amino terminus containing a pleckstrin-homology domain and a phosphotyrosine-binding domain, and a poorly conserved carboxy terminus containing several tyrosine phosphorylation motifs. IRS-2 is expressed in many cells, including tissues from IRS-1-/- mice, and may be essential for signalling by several receptor systems.

  11. Supercontinuum based mid-IR imaging spectroscopy for cancer detection

    DEFF Research Database (Denmark)

    Bang, Ole; Møller, Uffe Visbech; Kubat, Irnis

    2014-01-01

    The mid-infrared (IR) spectral region is of significant technical and scientific interest because most molecules display fundamental vibrational absorptions in this region, leaving distinct spectral fingerprints. To date, the limitations of mid-IR light sources, such as thermal emitters, low-powe...... cancer detection with mid-IR imaging spectroscopy.......-project.eu] DTU Fotonik has now demonstrated the first optical fiber based broadband so-called supercontinuum light souce, which covers 1.4-13.3 μm and thereby most of the molecular fingerprint region [1]. This ultra-fast light source is the basic component in the mid-IR camera developed in MINERVA for early...

  12. Local Mode Analysis: Decoding IR Spectra by Visualizing Molecular Details.

    Science.gov (United States)

    Massarczyk, M; Rudack, T; Schlitter, J; Kuhne, J; Kötting, C; Gerwert, K

    2017-04-20

    Integration of experimental and computational approaches to investigate chemical reactions in proteins has proven to be very successful. Experimentally, time-resolved FTIR difference-spectroscopy monitors chemical reactions at atomic detail. To decode detailed structural information encoded in IR spectra, QM/MM calculations are performed. Here, we present a novel method which we call local mode analysis (LMA) for calculating IR spectra and assigning spectral IR-bands on the basis of movements of nuclei and partial charges from just a single QM/MM trajectory. Through LMA the decoding of IR spectra no longer requires several simulations or optimizations. The novel approach correlates the motions of atoms of a single simulation with the corresponding IR bands and provides direct access to the structural information encoded in IR spectra. Either the contributions of a particular atom or atom group to the complete IR spectrum of the molecule are visualized, or an IR-band is selected to visualize the corresponding structural motions. Thus, LMA decodes the detailed information contained in IR spectra and provides an intuitive approach for structural biologists and biochemists. The unique feature of LMA is the bidirectional analysis connecting structural details to spectral features and vice versa spectral features to molecular motions.

  13. Local structural displacements across the structural phase transition in IrTe2: Order-disorder of dimers and role of Ir-Te correlations

    Science.gov (United States)

    Joseph, B.; Bendele, M.; Simonelli, L.; Maugeri, L.; Pyon, S.; Kudo, K.; Nohara, M.; Mizokawa, T.; Saini, N. L.

    2013-12-01

    We have studied local structure of IrTe2 by Ir L3-edge extended x-ray absorption fine structure (EXAFS) measurements as a function of temperature to investigate origin of the observed structural phase transition at Ts˜270 K. The EXAFS results show an appearance of longer Ir-Te bond length (ΔR ˜0.05 Å) at T Ir-Ir dimerization, characterized by distinct Ir-Ir bond lengths (ΔR ˜0.13 Å), existing both above and below Ts. The results suggest that the phase transition in IrTe2 should be an order-disorder-like transition of Ir-Ir dimers assisted by Ir-Te bond correlations, thus indicating important role of the interaction between the Ir 5d and Te 5p orbitals in this transition.

  14. Calibrated Mid-wave Infrared (IR) (MidIR) and Long-wave IR (LWIR) Stokes and Degree-of-Liner Polarization (DOLP)

    National Research Council Canada - National Science Library

    Gurton, Kristan P; Felton, Melvin

    2008-01-01

    ...., the 3-5 mu and 8-12 mu regions. Meteorological parameters measured during the study include temperature, relative humidity, wind speed/direction, precipitation, and ambient atmospheric IR loading...

  15. Spitzer IRS Observations of FU Orionis Objects

    Science.gov (United States)

    Green, J. D.; Hartmann, L.; Calvet, N.; Watson, D. M.; Ibrahimov, M.; Furlan, E.; Sargent, B.; Forrest, W. J.

    2006-09-01

    We present 5-35 μm spectra, taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope, of five FU Orionis objects: FU Ori, V1515 Cyg, V1057 Cyg, BBW 76, and V346 Nor. All but V346 Nor reveal amorphous silicate grains in emission at 10 and 20 μm, and show water-vapor absorption bands at 5.8 and 6.8 μm and SiO or possibly methane absorption at 8 μm. These absorption features closely match these bands in model stellar photospheres-signs of the gaseous photospheres of the inner regions of these objects' accretion disks. The continuum emission at 5-8 μm is also consistent with such disks, and, for FU Orionis and BBW 76, longer wavelength emission may be fit by a model that includes moderate disk flaring. V1057 Cyg and V1515 Cyg have much more emission at longer wavelengths than the others, perhaps evidence of a substantial remnant of their natal, infalling envelopes.

  16. Characterization of Hydrogen Bonds by IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Vojta, D.

    2012-05-01

    Full Text Available In the identification and quantification of hydrogen bond, as one of the most abundant non-covalent interactions in phenomena like self-assembly and molecular recognition, IR spectrosopy has been employed as the most sensitive method. The performance of the high dilution method enables determination of the stability constant of hydrogen-bonded complex as one of the most important thermodynamic quantities used in their characterization. However, the alleged experimental simplicity of the mentioned method is loaded with errors originating not only from researcher intervention but also independent from it. The second source of error is particularly emphasized and elaborated in this paper, which is designed as the recipe for the successful characterization of hydrogen bonds. Besides the enumeration of all steps in the determination of hydrogen-bonded stability constants, the reader can be acquainted with the most important ex perimental conditions that should be fulfilled in order to minimize the naturally occurring errors in this type of investigation. In the spectral analysis, the application of both uni- and multivariate approach has been discussed. Some computer packages, considering the latter, are mentioned, described, and recommended. KUI -10/2012Received August 1, 2011Accepted October 24, 2011

  17. Microstructures as IR-sensors with Staphylococcus aureus bacteria

    Science.gov (United States)

    Baikova, T. V.; Danilov, P. A.; Gonchukov, S. A.; Yermachenko, V. M.; Ionin, A. A.; Khmelnitskii, R. A.; Kudryashov, S. I.; Nguyen, T. T. H.; Rudenko, A. A.; Saraeva, I. N.; Svistunova, T. S.; Zayarny, D. A.

    2017-09-01

    Using a micro-hole grating in a supported silver film as a laser-fabricated novel optical platform for surface-enhanced IR absoprtion/reflection spectroscopy, characteristic absorption bands of Staphylococcus aureus, especially - its buried carotenoid fragments - were detected in FT-IR spectra with 10-fold analytical enhancement, paving the way to spectral express-identification of the pathogenic microorganisms.

  18. Cross calibration of IRS-P4 OCM satellite sensor

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Desa, E.; Mascarenhas, A.A.M.Q.; Matondkar, S.G.P.; Naik, P.; Nayak, S.R.

    obtained from the radiative transfer simulations of IRS-P4 OCM and SeaWiFS. The chlorophyll a values derived using the calibrated IRS-P4 OCM are found to be comparable with those derived from SeaWiFS and in close agreement with the measured values...

  19. NaIrO3-A pentavalent post-perovskite

    International Nuclear Information System (INIS)

    Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

    2011-01-01

    Sodium iridium (V) oxide, NaIrO 3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO 3 , the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO 3 . Among the oxide post-perovskites, NaIrO 3 is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO 6 octahedra separated by layers of NaO 8 bicapped trigonal prisms. NaIrO 3 shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides. -- Graphical abstract: Sodium iridium(V) oxide, NaIrO 3 , synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO 3 post-perovskite. Research highlights: → NaIrO 3 post-perovskite stabilized by pressure. → First example of a pentavalent oxide post-perovskite. → Non-metallic and non-magnetic behavior of NaIrO 3 .

  20. Understanding pave-IR : background, use, and advanced techniques

    Science.gov (United States)

    2010-01-01

    Why Has TxDOT Implemented Pave-IR? : Promote more uniform, higher quality pavements : Minimize/eliminate thermal segregation : Expand range of weather conditions for paving : Special Provision 341-024 : Contains option for contractor to use Pave-IR :...

  1. EXACT DIAGONALIZATION RESULTS FOR MULTIMAGNON IR ABSORPTION IN THE CUPRATES

    NARCIS (Netherlands)

    Lorenzana, J.; Eder, R; Meinders, M.B J; Sawatzky, G.A

    1995-01-01

    Recent measured bands in the mid IR of parent insulating compounds of cuprate superconductors [Perkins et al. Phys. Rev. Lett. 71 1621 (1993)] are interpreted as multimagnon infrared (IR) absorption assisted by phonons. We present results for the coupling constant of light with this excitations and

  2. New Directions for IR, the DQP, and Tuning

    Science.gov (United States)

    Jankowski, Natasha A.; Marshall, David W.

    2015-01-01

    This concluding essay provides a glimpse to the future and alerts IR professionals to related initiatives as well as provides an update to ongoing work with DQP and Tuning. Pulling from the prior chapters it provides some implications for IR offices to consider, not only in their work with the DQP and Tuning, but in terms of general decision…

  3. Bringing NMR and IR Spectroscopy to High Schools

    Science.gov (United States)

    Bonjour, Jessica L.; Hass, Alisa L.; Pollock, David W.; Huebner, Aaron; Frost, John A.

    2017-01-01

    Development of benchtop, portable Fourier transform nuclear magnetic resonance (NMR) and infrared (IR) spectrometers has opened up opportunities for creating university-high school partnerships that provide high school students with hands-on experience with NMR and IR instruments. With recent changes to the international baccalaureate chemistry…

  4. A Simulation Program for Dynamic Infrared (IR) Spectra

    Science.gov (United States)

    Zoerb, Matthew C.; Harris, Charles B.

    2013-01-01

    A free program for the simulation of dynamic infrared (IR) spectra is presented. The program simulates the spectrum of two exchanging IR peaks based on simple input parameters. Larger systems can be simulated with minor modifications. The program is available as an executable program for PCs or can be run in MATLAB on any operating system. Source…

  5. Median Measure: An Approach to IR Systems Evaluation.

    Science.gov (United States)

    Greisdorf, Howard; Spink, Amanda

    2001-01-01

    Results from three studies examining 1295 relevance judgments by 36 information retrieval (IR) system end-users are reported. Both the region of the relevance judgments, from non-relevant to highly relevant, and motivations or levels for the relevance judgments are examined. Implications for relevance theory and IR systems evaluation are…

  6. Operational experience - Lessons learned from IRS-reports in Germany

    International Nuclear Information System (INIS)

    Wetzel, N.; Maqua, M.

    2005-01-01

    The international Incident Reporting System (IRS), jointly operated by IAEA and OECD-NEA, is a main source of safety significant findings and lessons learned of nuclear operating experience. GRS (Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH) is a scientific-technical expert and research organisation. On Behalf of the Federal Minister of Environment, Nature Conservation and Reactor Safety (BMU), GRS provides the IRS officer. The evaluation of IRS-Reports and the dissemination of the main findings including the assessment of the relevance for German NPPs is task of GRS. The value of IRS is among experts undoubted. But nevertheless, the reporting to IRS decreases since some years. This presentation is aimed to show the support of IRS in strengthening the safety of German NPPs. The evaluation of IRS-Reports at GRS is three-fold. It comprises initial screening, quarterly and yearly reporting and the development of specific German Information Notices on safety significant events with direct applicability to German NPPs. Some examples of lessons learned from recent international events are discussed below. These examples shall demonstrate that the use of the IRS enhances significantly the knowledge on operational events. (author)

  7. 78 FR 913 - IRS Truncated Taxpayer Identification Numbers

    Science.gov (United States)

    2013-01-07

    ... using a social security number (SSN), IRS individual taxpayer identification number (ITIN), or IRS... individual's social security account number. Section 6109(d) provides that, except as otherwise specified under regulations, the social security account number issued to an individual under the Social Security...

  8. Simulation of Wakefield Effect in ILC IR Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Pei, S; Seryi, A.; Raubenheimer, T.O.; /SLAC

    2008-06-26

    To achieve super high luminosity, high current beams with very short bunch length are needed, which carry high intensity EM fields. For ILC, two bunch trains with bunch length of 300 {micro}m and bunch charge of 3.2nC are needed to collide at the IR to achieve the ILC luminosity goals. When the 300 {micro}m bunches pass through the IR chamber, wakefields will be excited, which will cause HOM power flowing through the IR chamber beam pipe to the final doublets due to the high frequency characteristic of the induced wakefields. Since superconducting technology is adopted for the final doublets of ILC BDS, whose operation stability might be affected by the HOM power produced at the IR chamber, quench might happen. In this paper, we did some analytical estimation and numerical simulation on the wakefield effects in ILC IR chamber.

  9. Defense Strategy of Aircraft Confronted with IR Guided Missile

    Directory of Open Access Journals (Sweden)

    Hesong Huang

    2017-01-01

    Full Text Available Surface-type infrared (IR decoy can simulate the IR characteristics of the target aircraft, which is one of the most effective equipment to confront IR guided missile. In the air combat, the IR guided missile poses a serious threat to the aircraft when it comes from the front of target aircraft. In this paper, firstly, the model of aircraft and surface-type IR decoy is established. To ensure their authenticity, the aircraft maneuver and radiation models based on real data of flight and exhaust system radiation in the state of different heights and different speeds are established. Secondly, the most effective avoidance maneuver is simulated when the missile comes from the front of the target aircraft. Lastly, combining maneuver with decoys, the best defense strategy is analysed when the missile comes from the front of aircraft. The result of simulation, which is authentic, is propitious to avoid the missile and improve the survivability of aircraft.

  10. Protection of p+-n-Si Photoanodes by Sputter-Deposited Ir/IrOxThin Films

    DEFF Research Database (Denmark)

    Mei, Bastian Timo; Seger, Brian; Pedersen, Thomas

    2014-01-01

    Sputter deposition of Ir/IrOx on p+-n-Si without interfacial corrosion protection layers yielded photoanodes capable of efficient water oxidation (OER) in acidic media (1 M H2SO4). Stability of at least 18 h was shown by chronoamperomety at 1.23 V versus RHE (reversible hydrogen electrode) under 38...

  11. The effect of test dose and first IR stimulation temperature on post-IR IRSL measurements of rock slices

    DEFF Research Database (Denmark)

    Liu, Jinfeng; Murray, Andrew; Sohbati, Reza

    2016-01-01

    lies close to the laboratory saturation levels only for higher first IR stimulation temperatures e.g. 200°C or 250°C. Our data confirm earlier suggestions based on sand-grain measurements that, for older sam-ples, accurate measurements close to saturation require that a higher first IR temperature...

  12. Metasurfaces for Terahertz Waves Polarization Control

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Malureanu, Radu; Zalkovskij, Maksim

    in the visible, near infrared or microwave regimes these issues in principle have strong alternatives via a conventional optics or electromagnetic approaches, at terahertz (THz) frequencies metamaterials are often considered as being the unique solution for the encountered problems. Several approaches involving...... that the maximal conversion efficiency with a single metamaterial surface is 50 % in transmission and up to 90% in reflection. However, a double layer transmission converter and a single layer with a metallic mirror can have 100% polarization conversion efficiency. We tested our conclusions numerically reaching...

  13. Vibrational energy relaxation in water-acetonitrile mixtures

    NARCIS (Netherlands)

    Cringus, D; Yeremenko, S; Pshenichnikov, MS; Wiersma, DA; Kobayashi, T; Okada, T; Kobayashi, T; Nelson, KA; DeSilvestri, S

    2005-01-01

    IR pump-probe spectroscopy is used to study the effect of hydrogen bonding on the vibrational energy relaxation pathways. Hydrogen bonding accelerates the population relaxation from 12ps in diluted acetonitrile solution to 700fs in bulk water.

  14. Vibrational energy relaxation in water-acetonitrile mixtures

    NARCIS (Netherlands)

    Cringus, Dan; Yeremenko, Sergey; Pshenichnikov, Maxim S.; Wiersma, Douwe A.

    2004-01-01

    IR pump-probe spectroscopy is used to study the effect of hydrogen bonding on the vibrational energy relaxation pathways. Hydrogen bonding accelerates the population relaxation from 12ps in diluted acetonitrile solution to 700fs in bulk water.

  15. Near-IR imaging of demineralization under sealants

    Science.gov (United States)

    Tom, Henry; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

    2014-02-01

    Previous studies have shown that near-IR reflectance and transillumination imaging can be used to acquire high contrast images of early caries lesions and composite restorative materials. The aim of the study was to determine the optimum near-IR wavelengths for imaging demineralized areas under dental sealants. Fifteen natural human premolars and molars with occlusal lesions were used in this in vitro study. Images before and after application of sealants were acquired using near-IR reflectance and near-IR transillumination at wavelengths of 1300 nm, 1460 nm, and 1500 - 1700 nm. Images were also acquired using polarization sensitive optical coherence tomography for comparison. The highest contrast for near- IR reflectance was at 1460 nm and 1500 - 1700 nm. These near-IR wavelengths are coincident with higher water absorption. The clear Delton sealant investigated was not visible in either co-polarization or crosspolarization OCT images. The wavelength region between 1500-1700-nm yielded the highest contrast of lesions under sealants for near-IR reflectance measurements.

  16. Patient Safety in Interventional Radiology: A CIRSE IR Checklist.

    LENUS (Irish Health Repository)

    2012-02-01

    Interventional radiology (IR) is an invasive speciality with the potential for complications as with other invasive specialities. The World Health Organization (WHO) produced a surgical safety checklist to decrease the morbidity and mortality associated with surgery. The Cardiovascular and Interventional Society of Europe (CIRSE) set up a task force to produce a checklist for IR. Use of the checklist will, we hope, reduce the incidence of complications after IR procedures. It has been modified from the WHO surgical safety checklist and the RAD PASS from Holland.

  17. Miesto šventinė įranga ir apipavidalinimas

    OpenAIRE

    Šimoliūnas, Tadas

    2008-01-01

    Magistro darbas “ Miesto šventinė įranga ir apipavidalinimas“ apima kelis objektus. Tai kompleksinio projektavimo darbas, kuriame labai svarbus ansambliškumas, bei harmoninga visuma. Kuriant šventinę įrangą buvo remiamasi bioninėmis formomis. Improvizuotos gyvosios gamtos formos įgalina sukurti neįprastus objektus, turinčius savitą stilistiką, tektoniką, ritmiką ir charakterį. Būtent iš gamtos nesenkančio šaltinio galima semtis naujų idėjų funkciniu ir estetiniu atžvilgiais. Lengvos konstrukc...

  18. Resonant photothermal IR spectroscopy of picogram samples with microstring resonator

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Boisen, Anja

    2013-01-01

    Here, we report a demonstration of resonant photothermal IR spectroscopy using microstrings in mid-infrared region providing rapid identification of picogram samples. In our microelectromechanical resonant photothermal IR spectroscopy system, samples are deposited directly on microstrings using...... an in-situ sampling method and the resonance frequency of the string is measured optically. Resonance frequency shifts, proportional to the absorbed heat, are recorded in real time as monochromatic infrared light is being scanned over the mid-infrared range. These resonant photothermal IR spectroscopy...

  19. Thin Film Electrodeposition of Ir(III Cyclometallated Complexes

    Directory of Open Access Journals (Sweden)

    Andreea Ionescu

    2016-01-01

    Full Text Available Novel electropolymerizable Ir(III cyclometallated complexes have been synthesized and characterized. In these complexes the cyclometallated ligands are either 2-phenylpyridine H(PhPy or benzothiazole-triphenylamine H(BzTh-tpa, while the Ir(III coordination sphere is completed by a Schiff base substituted with a triphenylamine fragment. A complete electrochemical study has been conducted on all complexes, in order to verify the feasibility of electropolymerization and to elucidate the role of the specific position of the triphenylamine moiety in the molecular structure. Homogeneous thin films of Ir(III metallopolymers have been successfully obtained through electropolymerization process.

  20. Linearly Polarized IR Spectroscopy Theory and Applications for Structural Analysis

    CERN Document Server

    Kolev, Tsonko

    2011-01-01

    A technique that is useful in the study of pharmaceutical products and biological molecules, polarization IR spectroscopy has undergone continuous development since it first emerged almost 100 years ago. Capturing the state of the science as it exists today, "Linearly Polarized IR Spectroscopy: Theory and Applications for Structural Analysis" demonstrates how the technique can be properly utilized to obtain important information about the structure and spectral properties of oriented compounds. The book starts with the theoretical basis of linear-dichroic infrared (IR-LD) spectroscop

  1. Chlorination of (PheboxIr(mesityl(OAc by Thionyl Chloride

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2015-06-01

    Full Text Available Pincer (PheboxIr(mesityl(OAc (2 (Phebox = 3,5-dimethylphenyl-2,6-bis(oxazolinyl complex, formed by benzylic C-H activation of mesitylene (1,3,5-trimethylbenzene using (PheboxIr(OAc2OH2 (1, was treated with thionyl chloride to rapidly form 1-(chloromethyl-3,5-dimethylbenzene in 50% yield at 23 °C. A green species was obtained at the end of reaction, which decomposed during flash column chromatography to form (PheboxIrCl2OH2 in 87% yield.

  2. Investigation of mid-IR picosecond image upconversion

    DEFF Research Database (Denmark)

    Mathez, Morgan David; Pedersen, Christian; Rodrigo, Peter John

    2017-01-01

    Imaging and spectroscopy in the mid-infrared (Mid-IR) wavelength region have received considerable attention in recent years. The reason is the high Mid-IR spectral specificity of many gases and complex molecules. In this pilot study we focus on picosecond upconversion imaging exploiting the χ(2......) nonlinearity of a bulk lithium niobate crystal as a means to convert the optical Mid-IR signal into the visible wavelength region, thus allowing the use of fast and sensitive silicon based CCD cameras. The picosecond upconversion system is synchronously pumped in order to increase the quantum efficiency, hence...

  3. Ion beam synthesis of IrSi3 by implantation of 2 MeV Ir ions

    International Nuclear Information System (INIS)

    Sjoreen, T.P.; Chisholm, M.F.; Hinneberg, H.J.

    1992-11-01

    Formation of a buried IrSi 3 layer in (111) oriented Si by ion implantation and annealing has been studied at an implantation energy of 2 MeV for substrate temperatures of 450--550C. Rutherford backscattering (RBS), ion channeling and cross-sectional transmission electron microscopy showed that a buried epitaxial IrSi 3 layer is produced at 550C by implanting ≥ 3.4 x 10 17 Ir/cm 2 and subsequently annealing for 1 h at 1000C plus 5 h at 1100C. At a dose of 3.4 x 10 17 Ir/cm 2 , the thickness of the layer varied between 120 and 190 nm and many large IrSi 3 precipitates were present above and below the film. Increasing the dose to 4.4 x 10 17 Ir/cm 2 improved the layer uniformity at the expense of increased lattice damage in the overlying Si. RBS analysis of layer formation as a function of substrate temperature revealed the competition between the mechanisms for optimizing surface crystallinity vs. IrSi 3 layer formation. Little apparent substrate temperature dependence was evident in the as-implanted state but after annealing the crystallinity of the top Si layer was observed to deteriorate with increasing substrate temperature while the precipitate coarsening and coalescence improved

  4. Fleet Protection Using a Small UAV Based IR Sensor

    National Research Council Canada - National Science Library

    Buss, James R; Ax, Jr, George R

    2005-01-01

    A study was performed to define candidate electro-optical and infrared (EO/IR) sensor configurations and assess their potential utility as small UAV-based sensors surveilling a perimeter around surface fleet assets...

  5. FT-IR, RAMAN AND DFT STUDIES ON THE VIBRATIONAL ...

    African Journals Online (AJOL)

    Bis(aminoethoxy)propane, IR spectra, Raman spectra, Molecular structure, DFT. INTRODUCTION. Ketal based linkages have recently been investigated for the development of novel acid- cleavable polymers those are formulated into the ...

  6. Characterization of Momordica charantia Ussing FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Attila Keseru

    2016-11-01

    In this paper, because earlier claim shows that the plant used as stomachic, carminative, tonic, antipyretic, antidiabetic, in rheumatoid arthritis and gout, the present investigation was carried to characterized a principal components of plant using FT-IR technique

  7. COMPARISON OF SIMPLE AND CHELATED AMBERLITE IR-120 ...

    African Journals Online (AJOL)

    13] have also been used. Many chelating ligands such as quinolone, ... synthesized by covalent bonds are much more resistant to external effects than those by simple adsorption [15]. Amberlite IR-120, a vinyl benzene polymer has good ...

  8. Analysis of effect of cable degradation on SPND IR calculation

    International Nuclear Information System (INIS)

    Tamboli, P.K.; Sharma, A.; Prasad, A.D.; Singh, Nita; Antony, J.; Kelkar, M.G.; Kaurav, Reetesh; Pramanik, M.

    2013-01-01

    Neutron flux is the most vital parameter in the nuclear reactor safety against Neutronic over power. The modern days Indian PHWRs with large core size are loosely coupled reactors and hence In-core Self Power Neutron Detectors (SPNDs) are most suitable for monitoring local neutron power for generating Regional Overpower Trip. However the SPNDs and its Mineral Insulation Cable are prone to IR loss due to use of ceramic insulation which are highly hygroscopic. The present paper covers the online analysis of IR f degraded cable as per the surveillance requirement of monitoring the IR to assess the healthiness of SPNDs which are part of SSC/SSE for Reactor Protection Systems. The paper also proposes an alternative method for monitoring IR for startup//low power range when SPND signals are yet to pick up and Reactor Control and Protection are based on out of core Ionization Chambers. (author)

  9. Dynamic IR Scene Projector Based Upon the Digital Micromirror Device

    National Research Council Canada - National Science Library

    Beasley, D. B; Bender, Matt; Crosby, Jay; Messer, Tim; Saylor, Daniel A

    2001-01-01

    ...). The MAPS is based upon the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project images which are suitable for testing sensor and seekers operating in the UV, visible, and IR wavebands...

  10. Upconversion applied for mid-IR hyperspectral image acquisition

    DEFF Research Database (Denmark)

    Tidemand-Lichtenberg, Peter; Kehlet, Louis Martinus; Sanders, Nicolai Højer

    2015-01-01

    Different schemes for upconversion mid-IR hyperspectral imaging is implemented and compared in terms of spectral coverage, spectral resolution, speed and noise. Phasematch scanning and scanning of the object within the field of view is considered....

  11. PTEN is a protein tyrosine phosphatase for IRS1.

    Science.gov (United States)

    Shi, Yuji; Wang, Junru; Chandarlapaty, Sarat; Cross, Justin; Thompson, Craig; Rosen, Neal; Jiang, Xuejun

    2014-06-01

    The biological function of the PTEN tumor suppressor is mainly attributed to its lipid phosphatase activity. This study demonstrates that mammalian PTEN is a protein tyrosine phosphatase that selectively dephosphorylates insulin receptor substrate-1 (IRS1), a mediator of insulin and IGF signals. IGF signaling was defective in cells lacking NEDD4, a PTEN ubiquitin ligase, whereas AKT activation triggered by EGF or serum was unimpaired. Defective IGF signaling caused by NEDD4 deletion, including phosphorylation of IRS1 and AKT, was rescued by PTEN ablation. We demonstrate the nature of PTEN as an IRS1 phosphatase by direct biochemical analysis and cellular reconstitution, showing that NEDD4 supports insulin-mediated glucose metabolism and is required for the proliferation of IGF1 receptor-dependent but not EGF receptor-dependent tumor cells. Thus, PTEN is a protein phosphatase for IRS1, and its antagonism by NEDD4 promotes signaling by IGF and insulin.

  12. A Modified Harris Corner Detection for Breast IR Image

    Directory of Open Access Journals (Sweden)

    Chia-Yen Lee

    2014-01-01

    Full Text Available Harris corner detectors, which depend on strong invariance and a local autocorrelation function, display poor detection performance for infrared (IR images with low contrast and nonobvious edges. In addition, feature points detected by Harris corner detectors are clustered due to the numerous nonlocal maxima. This paper proposes a modified Harris corner detector that includes two unique steps for processing IR images in order to overcome the aforementioned problems. Image contrast enhancement based on a generalized form of histogram equalization (HE combined with adjusting the intensity resolution causes false contours on IR images to acquire obvious edges. Adaptive nonmaximal suppression based on eliminating neighboring pixels avoids the clustered features. Preliminary results show that the proposed method can solve the clustering problem and successfully identify the representative feature points of IR breast images.

  13. Surface temperature measurements of heterogeneous explosives by IR emission

    Energy Technology Data Exchange (ETDEWEB)

    Henson, B.F.; Funk, D.J.; Dickson, P.M.; Fugard, C.S.; Asay, B.W.

    1998-03-01

    The authors present measurements of the integrated IR emission (1--5 {micro}m) from both the heterogeneous explosive PBX 9501 and pure HMX at calibrated temperatures from 300 C to 2,500 C. The IR power emitted as a function of temperature is that expected of a black body, attenuated by a unique temperature independent constant which the authors report as the thermal emissivity. The authors have utilized this calibration of IR emission in measurements of the surface temperature from PBX 9501 subject to 1 GPa, two dimensional impact, and spontaneous ignition in unconfined cookoff. They demonstrate that the measurement of IR emission in this spectral region provides a temperature probe of sufficient sensitivity to resolve the thermal response from the solid explosive throughout the range of weak mechanical perturbation, prolonged heating to ignition, and combustion.

  14. IceBridge KT19 IR Surface Temperature V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge KT19 IR Surface Temperature data set contains surface temperature measurements of Arctic and Antarctic sea ice and land ice acquired using the...

  15. Patient Safety in Interventional Radiology: A CIRSE IR Checklist

    NARCIS (Netherlands)

    Lee, M. J.; Fanelli, F.; Haage, P.; Hausegger, K.; van Lienden, K. P.

    2012-01-01

    Interventional radiology (IR) is an invasive speciality with the potential for complications as with other invasive specialities. The World Health Organization (WHO) produced a surgical safety checklist to decrease the morbidity and mortality associated with surgery. The Cardiovascular and

  16. Microstructure analysis of IrO2 thin films

    Science.gov (United States)

    Hou, Xiuyi; Takahashi, Ryota; Yamamoto, Takahisa; Lippmaa, Mikk

    2017-03-01

    We have grown IrO2 thin films on TiO2(110) substrates to determine the pulsed laser deposition growth window for iridates. Relaxed IrO2 films were obtained at a growth temperature of 500 °C and background oxygen pressure of 100 m Torr; otherwise, either pure Ir metal films or evaporative Ir loss were observed. Although x-ray Φ-scan measurement indicated that the films were epitaxial, a distinct grain structure was seen by atomic force microscopy and transmission electron microscopy. The grain boundaries were found to limit the conductivity of films at low temperature. It appeared that strain relaxation leads to stacking faults at grain boundaries.

  17. US-LHC IR magnet error analysis and compensation

    International Nuclear Information System (INIS)

    Wei, J.; Ptitsin, V.; Pilat, F.; Tepikian, S.; Gelfand, N.; Wan, W.; Holt, J.

    1998-01-01

    This paper studies the impact of the insertion-region (IR) magnet field errors on LHC collision performance. Compensation schemes including magnet orientation optimization, body-end compensation, tuning shims, and local nonlinear correction are shown to be highly effective

  18. Water equivalent phantom materials for 192 Ir brachytherapy

    OpenAIRE

    Schoenfeld, Andreas A.; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-01-01

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with 192Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading 192Ir brach...

  19. Dynamic IR scene projector using the digital micromirror device

    Science.gov (United States)

    Gao, JiaoBo; Wang, Jun; Yang, Bin; Wang, JiLong; Wang, WeiNa; Xie, JunHu; Hu, Yu

    2005-01-01

    We have developed a new dynamic infrared scene projector using the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project images which are suitable for testing sensor and seekers operating in the UV, visible, and IR wavebands. This paper provides an overview of the design and performance of the projection system, as well as example imagery from prototype projector systems. The dynamic IR scene contains 1024×768 pixels and can be updated at a rate of approximately 85 Hz.

  20. A study of the Al–Pt–Ir phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Grushko, B., E-mail: b.grushko@fz-juelich.de [MaTecK, 52428 Jülich (Germany); PGI-5, Forschungszentrum Jülich, 52425 Jülich (Germany); Samuha, S. [Dept. Materials Engineering, Ben-Gurion University of the Negev, 84105 Beer-Sheva (Israel); NRCN, P.O. Box 9001, 84190 Beer-Sheva (Israel); Meshi, L. [Dept. Materials Engineering, Ben-Gurion University of the Negev, 84105 Beer-Sheva (Israel)

    2015-10-15

    Phase equilibria in Al–Pt–Ir were studied up to 50 at.% Al at 1100 °C, up to 70 at.% Al at 900 °C and up to 75 at.% Al at 810 °C. At elevated temperatures the isostructural AlIr and high-temperature AlPt β-phases probably form a continuous compositional region. The ternary extensions of the phases Al{sub 4}Pt, Al{sub 21}Pt{sub 8}, Al{sub 3}Pt{sub 2} and low-temperature AlPt were revealed along approximately constant Al concentrations up to 15, 11, 20 and 10 at.% Ir, respectively. The Al–Ir C-phase dissolved up to 12 at.% Pt, and the χ-phase propagated up to almost Al{sub 3}Pt. A new ternary B-phase (I4{sub 1}/acd, a = 0.86250, c = 2.18409 nm) was revealed around Al{sub 69}Pt{sub 7}Ir{sub 24}. Its structural model was derived from the electron diffraction data. - Highlights: • The Al–Pt–Ir phase diagram was studied at 810, 900 and 1100 °C. • The majority of binaries extend widely along about constant Al. • The new ternary B-phase of the Ga{sub 4}Ir{sub 8}B type was revealed at Al{sub 69}Pt{sub 7}Ir{sub 24}. • The structural model of the B-phase was derived from electron diffraction.

  1. MERTIS - the design of a highly integrated IR imaging spectrometer

    OpenAIRE

    Walter, Ingo; Hirsch, Helmut; Knollenberg, Jörg; Jahn, Herbert; Säuberlich, Thomas; Venus, Holger; Skrbek, Wolfgang

    2006-01-01

    A belief that Mercury carries unique clues to the origin and evolution of the Solar System has driven the interest for detailed studies of the innermost planet. Here surface mineralogy requires information of the thermal inertia asking for observations by space borne instruments in the near IR and the thermal IR domain. With a background of several instrument developments in the past the German Aerospace Center in Berlin proposed for ESA’s deep space mission BepiColombo an imaging spectro...

  2. Thin Film Electrodeposition of Ir(III) Cyclometallated Complexes

    OpenAIRE

    Ionescu, Andreea; Aiello, Iolinda; Crispini, Alessandra; Godbert, Nicolas

    2016-01-01

    Novel electropolymerizable Ir(III) cyclometallated complexes have been synthesized and characterized. In these complexes the cyclometallated ligands are either 2-phenylpyridine H(PhPy) or benzothiazole-triphenylamine H(BzTh-tpa), while the Ir(III) coordination sphere is completed by a Schiff base substituted with a triphenylamine fragment. A complete electrochemical study has been conducted on all complexes, in order to verify the feasibility of electropolymerization and to elucidate the role...

  3. Fibre-Optic IR-Spectroscopy for Biomedical Diagnostics

    OpenAIRE

    Bindig, Uwe; Gersonde, Ingo; Meinke, Martina; Becker, Yukiyo; Müller, Gerhard

    2003-01-01

    The use of microscopy is a valuable means of gaining vital information for medical diagnostics. Due to a number of recent technological developments advances have been made in IR microscopy and in particular, rapid detection methods. Microscopic examination methods usually involve sampling followed by a method of sample purification or preparation. The advantages of the IR analytical method are that it is based on a direct, non‒destructive measurement of sample material and that the resulting...

  4. UV and IR Photochemistries of Malonaldehyde Trapped in Cryogenic Matrices.

    Science.gov (United States)

    Trivella, A; Wassermann, T N; Manca Tanner, C; Lüttschwager, N O B; Coussan, S

    2018-03-08

    UV and IR photochemistries of malonaldehyde, the simplest molecule exhibiting an intramolecular proton exchange, have been studied in four cryogenic matrices at 4.3 K, N 2 , Ne, Ar, and Xe. Samples have been irradiated using a UV and IR OPO type tunable laser, and with a broad band UV mercury lamp. UV and IR spectra have been recorded and compared with theoretical calculations carried out at the SAC-CI/6-31++G(d,p) (UV transitions) and B3LYP/6-311++G(2d,2p) (IR spectra) levels of theory. After deposition, the intramolecularly H-bonded form is found exclusively, while several open forms are formed upon UV irradiation. These open forms show ability to interconvert upon UV irradiation too. Some of them are also able to isomerize upon selective IR irradiations. The whole set of results allowed us to identify seven isomers among the eight postulated. The photodynamics of the electronic relaxation of malonaldehyde have also been investigated. By following the decay or rise of suited specific vibrational bands in the IR spectra, and by comparing the results with an earlier study of the homologous acetylacetone, we deduced that the electronic relaxation of malonaldehyde proceeds through singlet states, most probably through a 3-fold conical intersection, as postulated from theoretical calculations. In contrast with acetylacetone, malonaldehyde does not show fragmentation after UV excitation.

  5. Serial removal of caries lesions from tooth occlusal surfaces using near-IR image-guided IR laser ablation

    Science.gov (United States)

    Chan, Kenneth H.; Tom, Henry; Darling, Cynthia L.; Fried, Daniel

    2015-02-01

    Previous studies have established that caries lesions can be imaged with high contrast without the interference of stains at near-IR wavelengths greater than 1300-nm. It has been demonstrated that computer controlled laser scanning systems utilizing IR lasers operating at high pulse repetition rates can be used for serial imaging and selective removal of caries lesions. In this study, we report our progress towards the development of algorithms for generating rasterized ablation maps from near-IR reflectance images for the removal of natural lesions from tooth occlusal surfaces. An InGaAs camera and a filtered tungsten-halogen lamp producing near-IR light in the range of 1500-1700-nm were used to collect crosspolarization reflectance images of tooth occlusal surfaces. A CO2 laser operating at a wavelength of 9.3- μm with a pulse duration of 10-15-μs was used for image-guided ablation.

  6. Validation of the thermal code of RadTherm-IR, IR-Workbench, and F-TOM

    Science.gov (United States)

    Schwenger, Frédéric; Grossmann, Peter; Malaplate, Alain

    2009-05-01

    System assessment by image simulation requires synthetic scenarios that can be viewed by the device to be simulated. In addition to physical modeling of the camera, a reliable modeling of scene elements is necessary. Software products for modeling of target data in the IR should be capable of (i) predicting surface temperatures of scene elements over a long period of time and (ii) computing sensor views of the scenario. For such applications, FGAN-FOM acquired the software products RadTherm-IR (ThermoAnalytics Inc., Calumet, USA; IR-Workbench (OKTAL-SE, Toulouse, France). Inspection of the accuracy of simulation results by validation is necessary before using these products for applications. In the first step of validation, the performance of both "thermal solvers" was determined through comparison of the computed diurnal surface temperatures of a simple object with the corresponding values from measurements. CUBI is a rather simple geometric object with well known material parameters which makes it suitable for testing and validating object models in IR. It was used in this study as a test body. Comparison of calculated and measured surface temperature values will be presented, together with the results from the FGAN-FOM thermal object code F-TOM. In the second validation step, radiances of the simulated sensor views computed by RadTherm-IR and IR-Workbench will be compared with radiances retrieved from the recorded sensor images taken by the sensor that was simulated. Strengths and weaknesses of the models RadTherm-IR, IR-Workbench and F-TOM will be discussed.

  7. New infrared observations of IRS1, IRS3, and the adjacent nebula in the OMC-2 cluster

    Science.gov (United States)

    Pendleton, Y.; Werner, M.; Capps, R.; Dinerstein, H. L.

    1984-01-01

    Observations of the infrared cluster of low luminosity protostars in Orion Molecular Cloud 2 (OMC2) are reported. Results show that the asymmetric distribution of the extended emission seen about IRS1 is another infrared reflection nebula. Energy distributions show that the spectral shape is fairly constant throughout the nebula which indicates there is little internal extinction within this region. Integrated surface brightness values show that the nebula is 5 times brighter than IRS1 at K. Energy distributions show that IRS1 has a more pronounced ice band absorption feature at 3.1 micron; suggesting that there is more extinction along the direct line of sight to IRS1 than along a line from IRS1 to the scattering grains and then to the observer. The distribution of the extended emission around IRS1 is similar to the reflection nebula seen in NGC 7538 (Werner et al. 1979). The asymmetric shapes of the two nebulae are similar and in each case there is excess extinction along line of sight to the illuminating source.

  8. Myocardial loss of IRS1 and IRS2 causes heart failure and is controlled by p38α MAPK during insulin resistance.

    Science.gov (United States)

    Qi, Yajuan; Xu, Zihui; Zhu, Qinglei; Thomas, Candice; Kumar, Rajesh; Feng, Hao; Dostal, David E; White, Morris F; Baker, Kenneth M; Guo, Shaodong

    2013-11-01

    Cardiac failure is a major cause of death in patients with type 2 diabetes, but the molecular mechanism that links diabetes to heart failure remains unclear. Insulin resistance is a hallmark of type 2 diabetes, and insulin receptor substrates 1 and 2 (IRS1 and IRS2) are the major insulin-signaling components regulating cellular metabolism and survival. To determine the role of IRS1 and IRS2 in the heart and examine whether hyperinsulinemia causes myocardial insulin resistance and cellular dysfunction via IRS1 and IRS2, we generated heart-specific IRS1 and IRS2 gene double-knockout (H-DKO) mice and liver-specific IRS1 and IRS2 double-knockout (L-DKO) mice. H-DKO mice had reduced ventricular mass; developed cardiac apoptosis, fibrosis, and failure; and showed diminished Akt→forkhead box class O-1 signaling that was accompanied by impaired cardiac metabolic gene expression and reduced ATP content. L-DKO mice had decreased cardiac IRS1 and IRS2 proteins and exhibited features of heart failure, with impaired cardiac energy metabolism gene expression and activation of p38α mitogen-activated protein kinase (p38). Using neonatal rat ventricular cardiomyocytes, we further found that chronic insulin exposure reduced IRS1 and IRS2 proteins and prevented insulin action through activation of p38, revealing a fundamental mechanism of cardiac dysfunction during insulin resistance and type 2 diabetes.

  9. PENDIDIKAN AKHLAK MUSLIMAT MELALUISYA’IR : ANALISIS GENDER ATAS AJARAN SYI’IR MUSLIMAT KARYA NYAI WANIFAH KUDUS

    Directory of Open Access Journals (Sweden)

    Nur Said

    2016-03-01

    Full Text Available Penelitian ini difokuskan pada tiga hal: (1 Apakah karakteristik lingkup isi Syi’ir Muslimat?, (2 Bagai-manakah kondisi sosial budaya pada saat naskah ditulis oleh penulis?, (3 Apa nilai-nilai pendidikan moral bagi perempuan Muslim di isi Syi’ir Muslimat dalam perspektif gender?. Penelitian ini menggunakan pendekatan filologi dengan meningkatkan penggunaan analisis gender. Hasil dari penelitian ini adalah: Pertama, Syi’ir Muslimat ditulis oleh Nyai Wanifah, seorang wanita yang hidup pada zaman kolonial Belanda dipesantren tradisi di Kudus, Jawa Tengah. Kedua, beberapa nilai pendidikan moral di Syi’ir Muslimatantara lain: (1 Pentingnya pendidikan moral, (2 Bahaya perempuan bodoh; (3 Pentingnya belajar bagi perempuan di usia dini, (4 Etika menghias diri; (5 Bahaya materialisme, (6 Etika hubungan keluarga; (7 Dari rumah untuk mencapai surga; (8 Berhati-hatilah dengan tipu iblis; (9 Hindari perzinahan; (10 yang penting dari penutupan aurot; (11 yang ditujukan kepada orang tua. Ketiga, meskipun ada beberapa senyawa yang bias gender dalam Syi’ir Muslimat misalnya: (a Ada penjelasan yang menunjukkan bahwa perempuan lebih rendah dibandingkan laki-laki dalam derajat, (2 Pernyataan bahwa wanita bicara dibandingkan laki-laki, (3 wanita hanya cocok di wilayah domestik; Namun secara umum nasihat di syi’ir masih sangat relafen dalam konteks sekarang, terutama untuk memberikan solusi alternatif dalam merespon krisis moral bangsa terutama pada wanita generasi muda. Kata kunci: Syi’ir Muslimat, Pendidikan Karakter, Analisis Gender. This study focused on three things: (1 What is the characteristics of the scope of contents of Syi’ir Muslimat?, (2 What is the socio-cultural conditions at the time the manuscript was written by the author?, (3 What are the moral education values for Muslim women in the content of Syi’ir Muslimat in the perspective of gender?. This research uses a philological approach with enhanced use of gender analysis. The

  10. [HOMA-IR in patients with chronic hepatitis C].

    Science.gov (United States)

    Botshorishvili, T; Vashakidze, E

    2012-02-01

    The aim of investigation was to study the frequency of IR in type of viral hepatitis C, correlation with the degree of hepatic lesion and liver cirrhosis. 130 patients were investigated: 20 with acute hepatitis C; 38 with chronic hepatitis C; 72 with cirrhosis: among them 10 with Stage A, 14 with Stage B and 48 with Stage C. Also we used 30 healthy people as the controls. The study demonstrates significant changes of insulin, glucose, HOMA-IR type of viral hepatitis C, correlation with the degree of hepatic lesion and liver cirrhosis. In patients with liver cirrhosis levels of HOMA-IR is higher than in patients with chronic hepatitis C. In patients with acute hepatitis C levels of HOMA-IR was normal as in the control group. The results showed that various types of chronic viral hepatitis C and stages of cirrhosis set to increase HOMA-IR versus the controls., which were the most prominent in cases of severe hepatic lesion, which indicates that insulin resistance is a frequent companion of CHC.

  11. Ecological and agricultural applications of synchrotron IR microscopy

    Science.gov (United States)

    Raab, T. K.; Vogel, J. P.

    2004-10-01

    The diffraction-limited spot size of synchrotron-based IR microscopes provides cell-specific, spectrochemical imaging of cleared leaf, stem and root tissues of the model genetic organism Arabidopsis thaliana, and mutant plants created either by T-DNA insertional inactivation or chemical mutagenesis. Spectra in the wavelength region from 6 to 12 μm provide chemical and physical information on the cell wall polysaccharides of mutants lacking particular biosynthetic enzymes ("Cellulose synthase-like" genes). In parallel experiments, synchrotron IR microscopy delineates the role of Arabidopsis cell wall enzymes as susceptibility factors to the fungus Erysiphe cichoracearum, a causative agent of powdery mildew disease. Three genes, pmr4, pmr5, and pmr6 have been characterized by these methods, and biochemical relations between two of the genes suggested by IR spectroscopy and multivariate statistical techniques could not have been inferred through classical molecular biology. In ecological experiments, live plants can also be imaged in small microcosms with mid-IR transmitting ZnSe windows. Small exudate molecules may be spatially mapped in relation to root architecture at diffraction-limited resolution, and the effect of microbial symbioses on the quantity and quality of exudates inferred. Synchrotron IR microscopy provides a useful adjunct to molecular biological methods and underground observatories in the ongoing assessment of the role of root-soil-microbe communication.

  12. Crystal structure of the Al2CuIr phase

    International Nuclear Information System (INIS)

    Meshi, L.; Ezersky, V.; Kapush, D.; Grushko, B.

    2010-01-01

    A new ternary Al 2 CuIr phase was revealed in the Al-Cu-Ir system. It is formed below 1063 o C from the β-phase (CsCl-type structure) extending at elevated temperatures from AlIr. The crystal structure of the Al 2 CuIr phase was determined using a combination of precession electron diffraction and X-ray powder diffraction techniques. The phase has an orthorhombic C-centered unit cell with lattice parameters a = 8.1196(7) A, b = 5.0646(2) A and c = 5.18513(3) A; its crystal symmetry can be described by the Cmme (no. 67) space group (Pearson symbol oC16). The unit cell of the new phase contains 8 Al, 4 Cu and 4 Ir atoms and exhibits a new structure type. The reliability factors characterizing the Rietveld refinement procedure are: R p = 4.45%, R wp = 6.45%, R B = 3.69% and R f = 2.41%.

  13. Short infrared (IR) laser pulses can induce nanoporation

    Science.gov (United States)

    Roth, Caleb C.; Barnes, Ronald A.; Ibey, Bennett L.; Glickman, Randolph D.; Beier, Hope T.

    2016-03-01

    Short infrared (IR) laser pulses on the order of hundreds of microseconds to single milliseconds with typical wavelengths of 1800-2100 nm, have shown the capability to reversibly stimulate action potentials (AP) in neuronal cells. While the IR stimulation technique has proven successful for several applications, the exact mechanism(s) underlying the AP generation has remained elusive. To better understand how IR pulses cause AP stimulation, we determined the threshold for the formation of nanopores in the plasma membrane. Using a surrogate calcium ion, thallium, which is roughly the same shape and charge, but lacks the biological functionality of calcium, we recorded the flow of thallium ions into an exposed cell in the presence of a battery of channel antagonists. The entry of thallium into the cell indicated that the ions entered via nanopores. The data presented here demonstrate a basic understanding of the fundamental effects of IR stimulation and speculates that nanopores, formed in response to the IR exposure, play an upstream role in the generation of AP.

  14. IR emission and UV extinction in two open clusters

    International Nuclear Information System (INIS)

    Hackwell, J.A.; Hecht, J.H.

    1989-01-01

    Recent models of interstellar extinction have shown the importance of understanding both the UV and IR properties of interstellar dust grains. IRAS data have shown variations in 60 and 100 micron emissions presumably due to the presence of IR cirrus, while recent observations in the UV by Fitzpatrick and Massa have identified components in the UV extinction curve which vary in different star regions. A Draine and Anderson model connects these results by proposing that different size variations in interstellar grains would cause distinct changes in both the IR emission and the UV extinction. In order to test this model it is necessary to make observations in well defined locations away from peculiar extinction regions. In the infrared this means looking away from the galactic plane so as to limit non-local sources of IR radiation. Two open clusters that are out of the galactic plane and which contain a number of late B and early A stars suitable for UV extinction studies, and whose IRAS data show variations in the 60/100 micron ratio were studied. Based on the Drain and Anderson model, variations were expected in their UV extinction curves that correlate with the IR cirrus emission

  15. IR FPA sensor characterization and analysis using Matlab tm

    Science.gov (United States)

    Burke, Michael J.; Wan, William H.

    1998-08-01

    This paper documents the Matlab routines used to conduct infrared focal plane array (IR-FPA) sensor data analysis. Matlab is a commercially available software package that enables users to conduct a multitude of data analysis, file I/O, and generation of graphics with little or no computer programming skills. This effort was conducted in support of the US Army Tank-automotive and Armaments Command-Armament Research, Development and Engineering Center's (TACOM-ARDEC) 120 mm Precision Guided Mortar Munition (PGMM). PGMM's sensor included a 256 X 256 mid-band IR-FPA. This paper summarizes a primer generated to help train PGMM sensor engineers to use Matlab for conducting IR-FPA image analysis. A brief system description of the PGMM IR sensor will be presented, and follow by discussion on the Matlab IR-FPA image analysis, such as measurement of; FPA operability, Noise Equivalent Temperature Difference, temporal noise, spatial noise, as well as gain and offset calibration for non-uniformity correction.

  16. IR spectral analysis for the diagnostics of crust earthquake precursors

    Directory of Open Access Journals (Sweden)

    R. M. Umarkhodgaev

    2012-11-01

    Full Text Available Some possible physical processes are analysed that cause, under the condition of additional ionisation in a pre-breakdown electric field, emissions in the infrared (IR interval. The atmospheric transparency region of the IR spectrum at wavelengths of 7–15 μm is taken into account. This transparency region corresponds to spectral lines of small atmospheric constituents like CH4, CO2, N2O, NO2, NO, and O3. The possible intensities of the IR emissions observable in laboratories and in nature are estimated. The acceleration process of the electrons in the pre-breakdown electrical field before its adhesion to the molecules is analyzed. For daytime conditions, modifications of the adsorption spectra of the scattered solar emissions are studied; for nighttime, variations of emission spectra may be used for the analysis.

  17. Third-generation intelligent IR focal plane arrays

    Science.gov (United States)

    Caulfield, H. John; Jack, Michael D.; Pettijohn, Kevin L.; Schlesselmann, John D.; Norworth, Joe

    1998-03-01

    SBRC is at the forefront of industry in developing IR focal plane arrays including multi-spectral technology and '3rd generation' functions that mimic the human eye. 3rd generation devices conduct advanced processing on or near the FPA that serve to reduce bandwidth while performing needed functions such as automatic target recognition, uniformity correction and dynamic range enhancement. These devices represent a solution for processing the exorbitantly high bandwidth coming off large area FPAs without sacrificing systems sensitivity. SBRC's two-color approach leverages the company's HgCdTe technology to provide simultaneous multiband coverage, from short through long wave IR, with near theoretical performance. IR systems that are sensitive to different spectral bands achieve enhanced capabilities for target identification and advanced discrimination. This paper will provide a summary of the issues, the technology and the benefits of SBRC's third generation smart and two-color FPAs.

  18. Causality, Analyticity and an IR Obstruction to UV Completion

    CERN Document Server

    Adams, A; Dubovsky, S; Nicolis, A; Rattazzi, R; Adams, Allan; Arkani-Hamed, Nima; Dubovsky, Sergei; Nicolis, Alberto; Rattazzi, Riccardo

    2006-01-01

    We argue that certain apparently consistent low-energy effective field theories described by local, Lorentz-invariant Lagrangians, secretly exhibit macroscopic non-locality and cannot be embedded in any UV theory whose S-matrix satisfies canonical analyticity constraints. The obstruction involves the signs of a set of leading irrelevant operators, which must be strictly positive to ensure UV analyticity. An IR manifestation of this restriction is that the "wrong" signs lead to superluminal fluctuations around non-trivial backgrounds, making it impossible to define local, causal evolution, and implying a surprising IR breakdown of the effective theory. Such effective theories can not arise in quantum field theories or weakly coupled string theories, whose S-matrices satisfy the usual analyticity properties. This conclusion applies to the DGP brane-world model modifying gravity in the IR, giving a simple explanation for the difficulty of embedding this model into controlled stringy backgrounds, and to models of...

  19. IR spectroscopy of gaseous fluorocarbon ions: The perfluoroethyl anion

    Energy Technology Data Exchange (ETDEWEB)

    Crestoni, Maria Elisa; Chiavarino, Barbara [Dipartimento di Chimica e Tecnologie del Farmaco, Universita di Roma ' La Sapienza' , P. le A. Moro 5, I-00185 Roma (Italy); Lemaire, Joel; Maitre, Philippe [Universite Paris Sud, Laboratoire de Chimie Physique - UMR8000 CNRS, Faculte des Sciences - Batiment 350, 91405 Orsay Cedex (France); Fornarini, Simonetta, E-mail: simonetta.fornarini@uniroma1.it [Dipartimento di Chimica e Tecnologie del Farmaco, Universita di Roma ' La Sapienza' , P. le A. Moro 5, I-00185 Roma (Italy)

    2012-04-04

    Highlights: Black-Right-Pointing-Pointer C{sub 2}F{sub 5}{sup -} ions are formed by dissociative electron capture in perfluoropropane. Black-Right-Pointing-Pointer Both their reactivity towards neutrals and IRMPD spectroscopy are investigated. Black-Right-Pointing-Pointer The sampled C{sub 2}F{sub 5}{sup -} ions are best described as covalently bound pentafluoroethyl anions. - Abstract: The first IR spectrum of a perfluorinated carbanion has been obtained in the gas phase by IRMPD spectroscopy. Quantum chemical calculations at the MP2/cc-pVTZ level were performed yielding the optimized geometries and IR spectra for a covalently bound C{sub 2}F{sub 5}{sup -} species and for conceivable loosely bound F{sup -}(C{sub 2}F{sub 4}) complexes. Both the computational results and the IR characterization point to a covalent structure for the assayed species in agreement with the reactivity pattern displayed with selected neutrals.

  20. Jamming effectiveness analysis of IR smoke projectile based on sight optical observation

    Science.gov (United States)

    Wang, Longtao; Liu, Zhenxing; Wang, Falong

    2013-09-01

    This text makes use of the similar of the principle between IR imaging guided missile detection system and the general sight optics probe. In this text, the synopsis analysis on the jamming effectiveness of the IR smoke projectile resist the IR imaging guided missile is discussed. This research of the jamming technique to IR imaging guided missile have a very realistic meaning.

  1. Rapid discrimination of extracts of Chinese propolis and poplar buds by FT-IR and 2D IR correlation spectroscopy

    Science.gov (United States)

    Wu, Yan-Wen; Sun, Su-Qin; Zhao, Jing; Li, Yi; Zhou, Qun

    2008-07-01

    The extract of Chinese propolis (ECP) has recently been adulterated with that of poplar buds (EPB), because most of ECP is derived from the poplar plant, and ECP and EPB have almost identical chemical compositions. It is very difficult to differentiate them by using the chromatographic methods such as high performance liquid chromatography (HPLC) and gas chromatography (GC). Therefore, how to effectively discriminate these two mixtures is a problem to be solved urgently. In this paper, a rapid method for discriminating ECP and EPB was established by the Fourier transform infrared (FT-IR) spectra combined with the two-dimensional infrared correlation (2D IR) analysis. Forty-three ECP and five EPB samples collected from different areas of China were analyzed by the FT-IR spectroscopy. All the ECP and EPB samples tested show similar IR spectral profiles. The significant differences between ECP and EPB appear in the region of 3000-2800 cm -1 of the spectra. Based on such differences, the two species were successfully classified with the soft independent modeling of class analogy (SIMCA) pattern recognition technique. Furthermore, these differences were well validated by a series of temperature-dependent dynamic FT-IR spectra and the corresponding 2D IR plots. The results indicate that the differences in these two natural products are caused by the amounts of long-chain alkyl compounds (including long-chain alkanes, long-chain alkyl esters and long chain alkyl alcohols) in them, rather than the flavonoid compounds, generally recognized as the bioactive substances of propolis. There are much more long-chain alkyl compounds in ECP than those in EPB, and the carbon atoms of the compounds in ECP remain in an order Z-shaped array, but those in EPB are disorder. It suggests that FT-IR and 2D IR spectroscopy can provide a valuable method for the rapid differentiation of similar natural products, ECP and EPB. The IR spectra could directly reflect the integrated chemical

  2. RADIO MONITORING OF THE PERIODICALLY VARIABLE IR SOURCE LRLL 54361: NO DIRECT CORRELATION BETWEEN THE RADIO AND IR EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Forbrich, Jan, E-mail: jan.forbrich@univie.ac.at [University of Vienna, Department of Astrophysics, Türkenschanzstraße 17, A-1180 Vienna (Austria); Rodríguez, Luis F.; Palau, Aina; Zapata, Luis A. [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán (Mexico); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gutermuth, Robert A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2015-11-20

    LRLL 54361 is an infrared source located in the star-forming region IC 348 SW. Remarkably, its infrared luminosity increases by a factor of 10 over roughly one week every 25.34 days. To understand the origin of these remarkable periodic variations, we obtained sensitive 3.3 cm JVLA radio continuum observations of LRLL 54361 and its surroundings in six different epochs: three of them during the IR-on state and three during the IR-off state. The radio source associated with LRLL 54361 remained steady and did not show a correlation with the IR variations. We suggest that the IR is tracing the results of fast (with a timescale of days) pulsed accretion from an unseen binary companion, while the radio traces an ionized outflow with an extent of ∼100 AU that smooths out the variability over a period of the order of a year. The average flux density measured in these 2014 observations, 27 ± 5 μJy, is about a factor of two less than that measured about 1.5 years before, 53 ± 11 μJy, suggesting that variability in the radio is present, but over larger timescales than in the IR. We discuss other sources in the field, in particular two infrared/X-ray stars that show rapidly varying gyrosynchrotron emission.

  3. Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Zhi-Min [Harvard School of Public Health

    2013-04-28

    Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

  4. Feminism and IR and the Conditions for Critical Dialogue

    OpenAIRE

    Nicholls, Esteban

    2016-01-01

    My objective in this paper is to problematize the call for dialogue and engagement between feminists and non-feminist International Relations (IR) scholars. I will concentrate on two pieces of scholarship to discuss the issue of dialogue: first, Robert Keohane’s “Beyond Dychotomies: Conversations between International Relations and Feminist Theory’s” (Keohane, 1998); and second, Anne Tickner’s (1997) “You Just don’t Understand: Troubled Engagements between Feminists and IR Theorists.” In both...

  5. Thomas L.Friedman, „Lexus ir alyvmedis“, recenzija

    OpenAIRE

    Karpavičiūtė, Ieva

    2006-01-01

    Vienas dažniausiai cituojamų globalizacijos optimistų, hiperglobalistų - New York Times užsienio reikalų skilties apžvalgininkas Thomas L. Friedman, stengiasi savitai pažvelgti į globalizacijos procesus, išskirti pagrindines tendencijas, pažvelgti į jų teigiamas bei neigiamas pasekmes. T.L. Friedman dar 1999 metais išleistoje knygoje “Lexus ir alyvmedis” analizuoja globalėjimą, teigia technologinį determinizmą ir akcentuoja JAV vaidmens globalizacijos procesuose unikalumą bei svarbą. Knyga „L...

  6. High field Moessbauer study of dilute Ir-(Fe) alloys

    International Nuclear Information System (INIS)

    Takabatake, Toshiro; Mazaki, Hiromasa; Shinjo, Teruya.

    1981-01-01

    The magnetic behavior of very dilute Fe impurities in Ir has been studied by means of Moessbauer measurement in external fields up to 80 kOe at 4.2 K. The saturation hyperfine field increases in proportion to the external field up to the maximum magnetic field available. This means that for a localized spin fluctuation system IrFe, the effective magnetic moment associated with Fe impurities is induced in proportion to the external field. No anomalous spectrum was observed with a very dilute sample (--10 ppm 57 Co), indicating that the interaction between impurities is responsible for the anomalous spectrum previously observed with a less homogeneous sample. (author)

  7. Cost effective method of manual afterloading 192Ir brachytherapy

    International Nuclear Information System (INIS)

    Mohan, R.; Ravishankar, B.; Muralkrishna, B.V.

    2001-01-01

    Full text: In radiotherapy, brachytherapy mode of treatment has equal importance like the external beam radiotherapy. In our hospital we have manual afterloading 137 Cs kit supplied by BRIT for intracavitary treatment of carcinoma cervix and vaginal cases. In July 1999, we also started afterloading 192 Ir brachytherapy. For a hospital like ours, where funds are minimal, it is impossible to procure remote afterloading brachytherapy unit, which is very costly. So we have developed the cost-effective 192 Ir manual brachytherapy and so far we have done 60 cases which include intraluminal and interstitial cases

  8. Upconversion imager measures single mid-IR photons

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2013-01-01

    The most sensitive IR detectors today are based on exotic semicoductor technology such as indium antimonide or mercury cadmium telluride. High quality detectors of these sorts are expensive and suffer from high dark currents. Dark current can be somewhat alleviated by extreme cooling. Comparing t...

  9. SYNTHESIS, IR AND NMR SPECTRAL CORRELATIONS IN SOME ...

    African Journals Online (AJOL)

    Preferred Customer

    correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. KEY WORDS: Diimines, IR and NMR spectra, Spectral correlation, Hammett sigma constants.

  10. Multi-scale Adaptive Gain Control of IR Images

    NARCIS (Netherlands)

    Schutte, K.

    1997-01-01

    IR imagery tends to have a higher dynamic range then typical display devices such as a CRT. Global methods such as stretching and histogram equalization improve the visibility of many images, but some information in the images stays hidden for a human operator. This paper reports about the

  11. Spatially-resolved mid-IR spectroscopy of NGC 1068

    Science.gov (United States)

    Mason, R. E.; Geballe, T. R.; Packham, C.; Levenson, N. A.; Elitzur, M.; Fisher, R. S.; Perlman, E.

    2006-06-01

    We present spatially-resolved, near-diffraction-limited 10μm spectra of the nucleus of the Seyfert 2 galaxy NGC068. The spectra reveal striking variations in continuum slope, silicate feature profile and depth, and fine structure line fluxes on subarcsecond scales, illustrating in unprecedented detail the complexity of the circumnuclear regions of this galaxy at mid-IR wavelengths. The acquisition images show two distinct components: a compact (radius dust in the ionization cones. The observed spectrum of the compact source is compared with clumpy torus models, the first detailed comparison of such models with observational data. The models require most of the clouds to be located within a few parsecs of the central engine, in good agreement with recent mid-IR interferometric observations. However, the mid-IR flux measured with apertures larger than about 1 arcsec dominated by the dust emission from the ionization cones. Many previous attempts to determine the torus spectral energy distribution are thus likely to be significantly affected by contamination from the extended emission, highlighting the importance of spatial resolution in IR studies of nearby AGN.

  12. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    Administrator

    to study their structure systematically. IR spectrum of each glass composition shows a number of absorption bands. These bands are strongly influenced by the increasing substitution of SrO for PbO. Various bands shift with composition. Absorption peaks occur due to the vibrational mode of the borate network in these ...

  13. Mock Target Window OTR and IR Design and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Wass, Alexander Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-19

    In order to fully verify temperature measurements made on the target window using infrared (IR) optical non-contact methods, actual comparative measurements are made with a real beam distribution as the heat source using Argonne National Laboratory’s (ANL) 35 MeV electron accelerator. Using Monte Carlo N-Particle (MCNP) simulations and thermal Finite Element Analysis (FEA), a cooled mock target window with thermocouple implants is designed to be used in such a test to achieve window temperatures up to 700°C. An uncoated and blackcoated mock window is designed to enhance the IR temperature measurements and verify optical transmitted radiation (OTR) imagery. This allows us to fully verify and characterize our temperature accuracy with our current IR camera method and any future method we may wish to explore using actual production conditions. This test also provides us with valuable conclusions/concerns regarding the calibration method we developed using our IR test stand at TA-53 in MPF-14.

  14. IR Microspectrometers based on Linear-Variable Optical Filters

    NARCIS (Netherlands)

    Emadi, A.; Wu, H.; De Graaf, G.; Wolffenbuttel, R.F.

    2013-01-01

    This paper presents the design, fabrication and characterization of Infra-Red (IR) Linear Variable Optical Filter (LVOF)-based micro-spectrometers. Two LVOF microspectrometer designs have been realized: one for operating in the 1400 nm to 2500 nm wavelength range and another between 3000 nm and 5000

  15. Historical Materialism and the Postcolonial Challenge to IR

    DEFF Research Database (Denmark)

    Ougaard, Morten

    This paper addresses one of the “exemplary questions” listed by the panel conveners, namely: “How does the postcolonial perspective enable/disable the rethinking of theories and concepts considered central to critical IR?” This requires an explication of how I see the several parts of the exempla...

  16. Score Region Algebra: Building a Transparent XML-IR Database

    NARCIS (Netherlands)

    Mihajlovic, V.; Blok, H.E.; Hiemstra, Djoerd; Apers, Peter M.G.; Chowdhury, A.; Fuhr, N.; Ronthaler, M.; Schek, H-J.; Teiken, W.

    2005-01-01

    A unified database framework that will enable better comprehension of ranked XML retrieval is still a challenge in the XML database field. We propose a logical algebra, named score region algebra, that enables transparent specification of information retrieval (IR) models for XML databases. The

  17. Near-IR imaging of cracks in teeth.

    Science.gov (United States)

    Fried, William A; Simon, Jacob C; Lucas, Seth; Chan, Kenneth H; Darling, Cynthia L; Staninec, Michal; Fried, Daniel

    2014-02-18

    Dental enamel is highly transparent at near-IR wavelengths and several studies have shown that these wavelengths are well suited for optical transillumination for the detection and imaging of tooth decay. We hypothesize that these wavelengths are also well suited for imaging cracks in teeth. Extracted teeth with suspected cracks were imaged at several wavelengths in the near-IR from 1300-1700-nm. Extracted teeth were also examined with optical coherence tomography to confirm the existence of suspected cracks. Several teeth of volunteers were also imaged in vivo at 1300-nm to demonstrate clinical potential. In addition we induced cracks in teeth using a carbon dioxide laser and imaged crack formation and propagation in real time using near-IR transillumination. Cracks were clearly visible using near-IR imaging at 1300-nm in both in vitro and in vivo images. Cracks and fractures also interfered with light propagation in the tooth aiding in crack identification and assessment of depth and severity.

  18. Active IR System for Projectile Detection and Tracking

    Directory of Open Access Journals (Sweden)

    STANCIC, I.

    2017-11-01

    Full Text Available Reliable detection and tracking of high-speed projectiles is crucial in providing modern battlefield protection or to be used as a forensic tool. Subsonic projectiles fired from silenced weapons are difficult to detect, whereas reliable tracking of the projectile trajectory is hard to accomplish. Contemporary radar based counter-battery systems showed to be valuable in detection of incoming artillery fire, but are unable to provide detection at close ranges. In this paper, an active IR system is proposed that aims to detect and track incoming projectiles at close ranges. Proposed system is able to reconstruct projectile’s trajectory in space, predict impact location and estimate direction of projectile origin. Active detector system is based on a pair of high-speed cameras in stereo-configuration synced with computer and IR illuminator that emits coded IR light bursts. Innovative IR light coding enables automated detection and tracking of a nearby projectile and elimination of false positive alarms caused by distant objects.

  19. Phytochemical, IR Spectral and Biological Studies on the Leaf ...

    African Journals Online (AJOL)

    However, the n-hexane and diethyl ether fractions were not active against any of the test organisms even at 2000μg. The IR spectra of crude extract and fractions showed the presence of hydroxyl, carbonyl and aromatic systems which are in good agreement with results of the phytochemical analysis of the crude extract.

  20. The Community College IR Shop and Accreditation: A Case Study

    Science.gov (United States)

    Johnston, George

    2011-01-01

    This article presents results of a study the author recently conducted on the role of traditional institutional research (IR) offices in support of accreditation activities and institutional effectiveness. The purpose of the study was to confirm or disconfirm the utility of a theoretical model developed by Brittingham, O'Brien, and Alig (2008) of…

  1. Neo-Poulantzian Perspectives in IR and the Current Crisis

    DEFF Research Database (Denmark)

    Ougaard, Morten

    This paper is about Poulantzas, historical materialism, international relations, and the current crisis. My purpose is to discuss how some Poulantzian theoretical contributions can be applied to the study of subject matters that are the focus of academic fields such as International Relations (IR...

  2. The IR-4 Program - how it can benefit nurseries

    Science.gov (United States)

    J. Ray Frank

    2002-01-01

    The Interregional Research Project 4 (IR-4) was initiated in 1963 to obtain national pesticide label regsitrations for use on food and fiber. This program has an emphasis on minor uses or specialty crops. In this arena in the United States today it includes 600 crops.

  3. Assessment of the exchange parameters of Amberlite IR-45 (OH ...

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: Simple quantitative technique has been developed for assessing the exchange parameters of Amberlite IR. – 45 (OH) using column chromatographic techniques from the displacement of exchangeable hydroxyl ions of the resin by sulphate ions. The results obtained showed retention time of 33min, retention ...

  4. Isothermal anisotropic magnetoresistance in antiferromagnetic metallic IrMn.

    Science.gov (United States)

    Galceran, R; Fina, I; Cisneros-Fernández, J; Bozzo, B; Frontera, C; López-Mir, L; Deniz, H; Park, K-W; Park, B-G; Balcells, Ll; Martí, X; Jungwirth, T; Martínez, B

    2016-10-20

    Antiferromagnetic spintronics is an emerging field; antiferromagnets can improve the functionalities of ferromagnets with higher response times, and having the information shielded against external magnetic field. Moreover, a large list of aniferromagnetic semiconductors and metals with Néel temperatures above room temperature exists. In the present manuscript, we persevere in the quest for the limits of how large can anisotropic magnetoresistance be in antiferromagnetic materials with very large spin-orbit coupling. We selected IrMn as a prime example of first-class moment (Mn) and spin-orbit (Ir) combination. Isothermal magnetotransport measurements in an antiferromagnetic-metal(IrMn)/ferromagnetic-insulator thin film bilayer have been performed. The metal/insulator structure with magnetic coupling between both layers allows the measurement of the modulation of the transport properties exclusively in the antiferromagnetic layer. Anisotropic magnetoresistance as large as 0.15% has been found, which is much larger than that for a bare IrMn layer. Interestingly, it has been observed that anisotropic magnetoresistance is strongly influenced by the field cooling conditions, signaling the dependence of the found response on the formation of domains at the magnetic ordering temperature.

  5. Misaligned disks in the binary protostar IRS 43

    DEFF Research Database (Denmark)

    Brinch, Christian; Jørgensen, Jes Kristian; Hogerheijde, Michiel R.

    2016-01-01

    Recent high angular resolution (∼ 0\\buildrel{\\prime\\prime}\\over{.} 2) ALMA observations of the 1.1 mm continuum and of HCO+ J = 3–2 and HCN J = 3–2 gas toward the binary protostar IRS 43 reveal multiple Keplerian disks that are significantly misaligned (\\gt 60^\\circ ), both in inclination...

  6. Score Region Algebra: Building a Transparant XML-IR Database

    NARCIS (Netherlands)

    Mihajlovic, V.; Blok, H.E.; Hiemstra, Djoerd; Apers, Peter M.G.

    2005-01-01

    A unied database framework that will enable better comprehension of ranked XML retrieval is still a challenge in the XML database field. We propose a logical algebra, named score region algebra, that enables transparent specification of information retrieval (IR) models for XML databases. The

  7. The TIJAH XML-IR system at INEX 2003

    NARCIS (Netherlands)

    J.A. List; V. Mihajlovic; A.P. de Vries (Arjen); G. Ramirez Camps (Georgina); D. Hiemstra

    2003-01-01

    textabstractThis paper discusses our participation in INEX (the Initiative for the Evaluation of XML Retrieval) using the TIJAH XML-IR system. TIJAH's system design follows a `standard' layered database architecture, carefully separating the conceptual, logical and physical levels. At the conceptual

  8. Phytochemical, IR Spectral and Biological Studies on the Leaf ...

    African Journals Online (AJOL)

    MBI

    investigations some extracts of the root of C. africana were found to possess ... vapour and UV lamp (366+254 nm). IR measurements were ... ChemSearch Journal 4(1): 14 – 17, June, 2013. Publication of Chemical Society of Nigeria, Kano Chapter. Received: 31/05/2013. Accepted: 21/06/2013. C .S. N. C. H. E. M. IC. A.

  9. Assessment of the exchange parameters of Amberlite IR-45 (OH ...

    African Journals Online (AJOL)

    Simple quantitative technique has been developed for assessing the exchange parameters of Amberlite IR – 45 (OH) using column chromatographic techniques from the displacement of exchangeable hydroxyl ions of the resin by sulphate ions. The results obtained showed retention time of 33min, retention volume of ...

  10. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    Administrator

    IR study of Pb–Sr titanate borosilicate glasses. C R GAUTAM*, DEVENDRA KUMAR. † and OM PARKASH. †. Department of Physics, University of Lucknow, Lucknow 226 007, India. †. Department of Ceramic Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221 005, India. MS received 3 January ...

  11. Near-IR imaging of cracks in teeth

    Science.gov (United States)

    Fried, William A.; Simon, Jacob C.; Lucas, Seth; Chan, Kenneth H.; Darling, Cynthia L.; Staninec, Michal; Fried, Daniel

    2014-02-01

    Dental enamel is highly transparent at near-IR wavelengths and several studies have shown that these wavelengths are well suited for optical transillumination for the detection and imaging of tooth decay. We hypothesize that these wavelengths are also well suited for imaging cracks in teeth. Extracted teeth with suspected cracks were imaged at several wavelengths in the near-IR from 1300-1700-nm. Extracted teeth were also examined with optical coherence tomography to confirm the existence of suspected cracks. Several teeth of volunteers were also imaged in vivo at 1300-nm to demonstrate clinical potential. In addition we induced cracks in teeth using a carbon dioxide laser and imaged crack formation and propagation in real time using near-IR transillumination. Cracks were clearly visible using near-IR imaging at 1300-nm in both in vitro and in vivo images. Cracks and fractures also interfered with light propagation in the tooth aiding in crack identification and assessment of depth and severity.

  12. Development of nanostructured protective "sight glasses" for IR gas sensors

    DEFF Research Database (Denmark)

    Bergmann, René; Davis, Zachary James; Schmidt, Michael Stenbæk

    2011-01-01

    property of the surface could be enhanced, shown by contact angle and roll-off angle measurements. The "self-cleaning" surface property and chemical robustness towards aggressive environments are demonstrated. FT-IR spectroscopy concerning the optical properties of these nanostructured silicon windows...

  13. FT-IR, NMR SPECTROSCOPIC and QUANTUM MECHANICAL ...

    African Journals Online (AJOL)

    FT-IR, NMR SPECTROSCOPIC and QUANTUM MECHANICAL. INVESTIGATIONS OF TWO FERROCENE DERIVATIVES. Özgür Alver1* and Cemal Parlak2. 1Department of Physics, Science Faculty, Anadolu University, Eskişehir, 26470, Turkey. 2Department of Physics, Science Faculty, Ege University, İzmir, 35100, ...

  14. Iridium Sulfide and Ir Promoted Mo Based Catalysts.

    Czech Academy of Sciences Publication Activity Database

    Vít, Zdeněk

    2007-01-01

    Roč. 322, - (2007), s. 142-151 ISSN 0926-860X R&D Projects: GA ČR(CZ) GA104/06/0870 Institutional research plan: CEZ:AV0Z40720504 Keywords : iridium sulfide * IrMo catalyst * hydrodesulfurization Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.166, year: 2007

  15. Using IR Imaging of Water Surfaces for Estimating Piston Velocities

    Science.gov (United States)

    Gålfalk, M.; Bastviken, D.; Arneborg, L.

    2013-12-01

    The transport of gasses dissolved in surface waters across the water-atmosphere interface is controlled by the piston velocity (k). This coefficient has large implications for, e.g., greenhouse gas fluxes but is challenging to quantify in situ. At present, empirical k-wind speed relationships from a small number of studies and systems are often extrapolated without knowledge of model performance. It is therefore of interest to search for new methods for estimating k, and to compare the pros and cons of existing and new methods. Wind speeds in such models are often measured at a height of 10 meters. In smaller bodies of water such as lakes, wind speeds can vary dramatically across the surface through varying degrees of wind shadow from e.g. trees at the shoreline. More local measurements of the water surface, through wave heights or surface motion mapping, could give improved k-estimates over a surface, also taking into account wind fetch. At thermal infrared (IR) wavelengths water has very low reflectivity (depending on viewing angle) than can go below 1%, meaning that more than 99% is heat radiation giving a direct measurement of surface temperature variations. Using an IR camera at about 100 frames/s one could map surface temperature structures at a fraction of a mm depth even with waves present. In this presentation I will focus on IR imaging as a possible tool for estimating piston velocities. Results will be presented from IR field measurements, relating the motions of surface temperature structures to k calculated from other simultaneous measurements (flux chamber and ADV-Based Dissipation Rate), but also attempting to calculate k directly from the IR surface divergence. A relation between wave height and k will also be presented.

  16. Thermal-to-visible transducer (TVT) for thermal-IR imaging

    Science.gov (United States)

    Flusberg, Allen; Swartz, Stephen; Huff, Michael; Gross, Steven

    2008-04-01

    We have been developing a novel thermal-to-visible transducer (TVT), an uncooled thermal-IR imager that is based on a Fabry-Perot Interferometer (FPI). The FPI-based IR imager can convert a thermal-IR image to a video electronic image. IR radiation that is emitted by an object in the scene is imaged onto an IR-absorbing material that is located within an FPI. Temperature variations generated by the spatial variations in the IR image intensity cause variations in optical thickness, modulating the reflectivity seen by a probe laser beam. The reflected probe is imaged onto a visible array, producing a visible image of the IR scene. This technology can provide low-cost IR cameras with excellent sensitivity, low power consumption, and the potential for self-registered fusion of thermal-IR and visible images. We will describe characteristics of requisite pixelated arrays that we have fabricated.

  17. OGTT results in obese adolescents with normal HOMA-IR values.

    Science.gov (United States)

    Sahin, Nursel Muratoglu; Kinik, Sibel Tulgar; Tekindal, Mustafa Agah

    2013-01-01

    To investigate insulin resistance (IR) with OGTT in obese adolescents who have normal fasting insulin and homeostasis model assessment for insulin resistance (HOMA-IR). A total of 97 obese adolescents who had values of HOMA-IR 2083.5 pmol/L (300 μU/mL) in OGTT. IR risk factors were defined as family history of diabetes mellitus, acanthosis nigricans (AN), and hepatic steatosis. IR was detected in 61 (62.9%) patients. The IR group had significantly more frequent AN (p=0.0001). As the number of risk factors increased, the frequency of IR also increased (p=0.01). We advise to perform OGTT in obese adolescents with normal HOMA-IR, if they have risk factors for IR.

  18. Galaxy Evolution Studies with the SPace IR Telescope for Cosmology and Astrophysics (SPICA): The Power of IR Spectroscopy

    Science.gov (United States)

    Spinoglio, L.; Alonso-Herrero, A.; Armus, L.; Baes, M.; Bernard-Salas, J.; Bianchi, S.; Bocchio, M.; Bolatto, A.; Bradford, C.; Braine, J.; Carrera, F. J.; Ciesla, L.; Clements, D. L.; Dannerbauer, H.; Doi, Y.; Efstathiou, A.; Egami, E.; Fernández-Ontiveros, J. A.; Ferrara, A.; Fischer, J.; Franceschini, A.; Gallerani, S.; Giard, M.; González-Alfonso, E.; Gruppioni, C.; Guillard, P.; Hatziminaoglou, E.; Imanishi, M.; Ishihara, D.; Isobe, N.; Kaneda, H.; Kawada, M.; Kohno, K.; Kwon, J.; Madden, S.; Malkan, M. A.; Marassi, S.; Matsuhara, H.; Matsuura, M.; Miniutti, G.; Nagamine, K.; Nagao, T.; Najarro, F.; Nakagawa, T.; Onaka, T.; Oyabu, S.; Pallottini, A.; Piro, L.; Pozzi, F.; Rodighiero, G.; Roelfsema, P.; Sakon, I.; Santini, P.; Schaerer, D.; Schneider, R.; Scott, D.; Serjeant, S.; Shibai, H.; Smith, J.-D. T.; Sobacchi, E.; Sturm, E.; Suzuki, T.; Vallini, L.; van der Tak, F.; Vignali, C.; Yamada, T.; Wada, T.; Wang, L.

    2017-11-01

    IR spectroscopy in the range 12-230 μm with the SPace IR telescope for Cosmology and Astrophysics (SPICA) will reveal the physical processes governing the formation and evolution of galaxies and black holes through cosmic time, bridging the gap between the James Webb Space Telescope and the upcoming Extremely Large Telescopes at shorter wavelengths and the Atacama Large Millimeter Array at longer wavelengths. The SPICA, with its 2.5-m telescope actively cooled to below 8 K, will obtain the first spectroscopic determination, in the mid-IR rest-frame, of both the star-formation rate and black hole accretion rate histories of galaxies, reaching lookback times of 12 Gyr, for large statistically significant samples. Densities, temperatures, radiation fields, and gas-phase metallicities will be measured in dust-obscured galaxies and active galactic nuclei, sampling a large range in mass and luminosity, from faint local dwarf galaxies to luminous quasars in the distant Universe. Active galactic nuclei and starburst feedback and feeding mechanisms in distant galaxies will be uncovered through detailed measurements of molecular and atomic line profiles. The SPICA's large-area deep spectrophotometric surveys will provide mid-IR spectra and continuum fluxes for unbiased samples of tens of thousands of galaxies, out to redshifts of z 6.

  19. Ankyrin repeat and SOCS box containing protein 4 (Asb-4 colocalizes with insulin receptor substrate 4 (IRS4 in the hypothalamic neurons and mediates IRS4 degradation

    Directory of Open Access Journals (Sweden)

    Xia Zefeng

    2011-09-01

    Full Text Available Abstract Background The arcuate nucleus of the hypothalamus regulates food intake. Ankyrin repeat and SOCS box containing protein 4 (Asb-4 is expressed in neuropeptide Y and proopiomelanocortin (POMC neurons in the arcuate nucleus, target neurons in the regulation of food intake and metabolism by insulin and leptin. However, the target protein(s of Asb-4 in these neurons remains unknown. Insulin receptor substrate 4 (IRS4 is an adaptor molecule involved in the signal transduction by both insulin and leptin. In the present study we examined the colocalization and interaction of Asb-4 with IRS4 and the involvement of Asb-4 in insulin signaling. Results In situ hybridization showed that the expression pattern of Asb-4 was consistent with that of IRS4 in the rat brain. Double in situ hybridization showed that IRS4 colocalized with Asb-4, and both Asb-4 and IRS4 mRNA were expressed in proopiomelanocortin (POMC and neuropeptide Y (NPY neurons within the arcuate nucleus of the hypothalamus. In HEK293 cells co-transfected with Myc-tagged Asb-4 and Flag-tagged IRS4, Asb-4 co-immunoprecipitated with IRS4; In these cells endogenous IRS4 also co-immunoprecipitated with transfected Myc-Asb-4; Furthermore, Asb-4 co-immunoprecipitated with IRS4 in rat hypothalamic extracts. In HEK293 cells over expression of Asb-4 decreased IRS4 protein levels and deletion of the SOCS box abolished this effect. Asb-4 increased the ubiquitination of IRS4; Deletion of SOCS box abolished this effect. Expression of Asb-4 decreased both basal and insulin-stimulated phosphorylation of AKT at Thr308. Conclusions These data demonstrated that Asb-4 co-localizes and interacts with IRS4 in hypothalamic neurons. The interaction of Asb-4 with IRS4 in cell lines mediates the degradation of IRS4 and decreases insulin signaling.

  20. Compensatory insulin receptor (IR) activation on inhibition of insulin-like growth factor-1 receptor (IGF-1R): rationale for cotargeting IGF-1R and IR in cancer.

    Science.gov (United States)

    Buck, Elizabeth; Gokhale, Prafulla C; Koujak, Susan; Brown, Eric; Eyzaguirre, Alexandra; Tao, Nianjun; Rosenfeld-Franklin, Maryland; Lerner, Lorena; Chiu, M Isabel; Wild, Robert; Epstein, David; Pachter, Jonathan A; Miglarese, Mark R

    2010-10-01

    Insulin-like growth factor-1 receptor (IGF-1R) is a receptor tyrosine kinase (RTK) and critical activator of the phosphatidylinositol 3-kinase-AKT pathway. IGF-1R is required for oncogenic transformation and tumorigenesis. These observations have spurred anticancer drug discovery and development efforts for both biological and small-molecule IGF-1R inhibitors. The ability for one RTK to compensate for another to maintain tumor cell viability is emerging as a common resistance mechanism to antitumor agents targeting individual RTKs. As IGF-1R is structurally and functionally related to the insulin receptor (IR), we asked whether IR is tumorigenic and whether IR-AKT signaling contributes to resistance to IGF-1R inhibition. Both IGF-1R and IR(A) are tumorigenic in a mouse mammary tumor model. In human tumor cells coexpressing IGF-1R and IR, bidirectional cross talk was observed following either knockdown of IR expression or treatment with a selective anti-IGF-1R antibody, MAB391. MAB391 treatment resulted in a compensatory increase in phospho-IR, which was associated with resistance to inhibition of IRS1 and AKT. In contrast, treatment with OSI-906, a small-molecule dual inhibitor of IGF-1R/IR, resulted in enhanced reduction in phospho-IRS1/phospho-AKT relative to MAB391. Insulin or IGF-2 activated the IR-AKT pathway and decreased sensitivity to MAB391 but not to OSI-906. In tumor cells with an autocrine IGF-2 loop, both OSI-906 and an anti-IGF-2 antibody reduced phospho-IR/phospho-AKT, whereas MAB391 was ineffective. Finally, OSI-906 showed superior efficacy compared with MAB391 in human tumor xenograft models in which both IGF-1R and IR were phosphorylated. Collectively, these data indicate that cotargeting IGF-1R and IR may provide superior antitumor efficacy compared with targeting IGF-1R alone.

  1. IR-based spot weld NDT in automotive applications

    Science.gov (United States)

    Chen, Jian; Feng, Zhili

    2015-05-01

    Today's auto industry primarily relies on destructive teardown evaluation to ensure the quality of the resistance spot welds (RSWs) due to their criticality in crash resistance and performance of vehicles. The destructive teardown evaluation is labor intensive and costly. The very nature of the destructive test means only a few selected welds will be sampled for quality. Most of the welds in a car are never checked. There are significant costs and risks associated with reworking and scrapping the defective welded parts made between the teardown tests. IR thermography as a non-destructive testing (NDT) tool has its distinct advantage — its non-intrusive and non-contact nature. This makes the IR based NDT especially attractive for the highly automated assembly lines. IR for weld quality inspection has been explored in the past, mostly limited to the offline post-processing manner in a laboratory environment. No online real-time RSW inspection using IR thermography has been reported. Typically for postprocessing inspection, a short-pulse heating via xenon flash lamp light (in a few milliseconds) is applied to the surface of a spot weld. However, applications in the auto industry have been unsuccessful, largely due to a critical drawback that cannot be implemented in the high-volume production line - the prerequisite of painting the weld surface to eliminate surface reflection and other environmental interference. This is due to the low signal-to-noise ratio resulting from the low/unknown surface emissivity and the very small temperature changes (typically on the order of 0.1°C) induced by the flash lamp method. An integrated approach consisting of innovations in both data analysis algorithms and hardware apparatus that effectively solved the key technical barriers for IR NDT. The system can be used for both real-time (during welding) and post-processing inspections (after welds have been made). First, we developed a special IR thermal image processing method that

  2. Hybrid nanomaterial and its applications: IR sensing and energy harvesting

    Science.gov (United States)

    Tseng, Yi-Hsuan

    In this dissertation, a hybrid nanomaterial, single-wall carbon nanotubes-copper sulfide nanoparticles (SWNTs-CuS NPs), was synthesized and its properties were analyzed. Due to its unique optical and thermal properties, the hybrid nanomaterial exhibited great potential for infrared (IR) sensing and energy harvesting. The hybrid nanomaterial was synthesized with the non-covalent bond technique to functionalize the surface of the SWNTs and bind the CuS nanoparticles on the surface of the SWNTs. For testing and analyzing the hybrid nanomaterial, SWNTs-CuS nanoparticles were formed as a thin film structure using the vacuum filtration method. Two conductive wires were bound on the ends of the thin film to build a thin film device for measurements and analyses. Measurements found that the hybrid nanomaterial had a significantly increased light absorption (up to 80%) compared to the pure SWNTs. Moreover, the hybrid nanomaterial thin film devices exhibited a clear optical and thermal switching effect, which could be further enhanced up to ten times with asymmetric illumination of light and thermal radiation on the thin film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials was demonstrated, indicating a new route for achieving thermoelectricity. In addition, CuS nanoparticles have great optical absorption especially in the near-infrared region. Therefore, the hybrid nanomaterial thin films also have the potential for IR sensing applications. The first application to be covered in this dissertation is the IR sensing application. IR thin film sensors based on the SWNTs-CuS nanoparticles hybrid nanomaterials were fabricated. The IR response in the photocurrent of the hybrid thin film sensor was significantly enhanced, increasing the photocurrent by 300% when the IR light illuminates the thin film device asymmetrically. The detection limit could be as low as 48mW mm-2. The dramatically enhanced

  3. IR spectral analysis for the diagnostics of crust earthquake precursors

    Science.gov (United States)

    Umarkhodgaev, R. M.; Liperovsky, V. A.; Mikhailin, V. V.; Meister, C.-V.; Naumov, D. Ju

    2012-04-01

    In regions of future earthquakes, a few days before the seismic shock, the emanation of radon and hydrogen is being observed, which causes clouds of increased ionisation in the atmosphere. In the present work the possible diagnostics of these clouds using infrared (IR) spectroscopy is considered, which may be important and useful for the general geophysical system of earthquake prediction and the observation of industrial emissions of radioactive materials into the atmosphere. Some possible physical processes are analysed, which cause, under the condition of additional ionisation in a pre-breakdown electrical field, emissions in the IR interval. In doing so, the transparency region of the IR spectrum at wavelengths of 7-15 μm is taken into account. This transparency region corresponds to spectral lines of small atmospheric constituents like CH4, CO2, N2O, NO2, NO, and O3. The possible intensities of the IR emissions observable in laboratories and in nature are estimated. The acceleration process of the electrons in the pre-breakdown electrical field before its adhesion to the molecules is analysed. The laboratory equipment for the investigation of the IR absorption spectrum is constructed for the cases of normal and decreased atmospheric pressures. The syntheses of ozone and nitrous oxides are performed in the barrier discharge. It is studied if the products of the syntheses may be used to model atmospheric processes where these components take part. Spectra of products of the syntheses in the wavelength region of 2-10 μm are observed and analysed. A device is created for the syntheses and accumulation of nitrous oxides. Experiments to observe the IR-spectra of ozone and nitrous oxides during the syntheses and during the further evolution of these molecules are performed. For the earthquake prediction, practically, the investigation of emission spectra is most important, but during the laboratory experiments, the radiation of the excited molecules is shifted by a

  4. Assessment of COTS IR image simulation tools for ATR development

    Science.gov (United States)

    Seidel, Heiko; Stahl, Christoph; Bjerkeli, Frode; Skaaren-Fystro, Paal

    2005-05-01

    Following the tendency of increased use of imaging sensors in military aircraft, future fighter pilots will need onboard artificial intelligence e.g. ATR for aiding them in image interpretation and target designation. The European Aeronautic Defence and Space Company (EADS) in Germany has developed an advanced method for automatic target recognition (ATR) which is based on adaptive neural networks. This ATR method can assist the crew of military aircraft like the Eurofighter in sensor image monitoring and thereby reduce the workload in the cockpit and increase the mission efficiency. The EADS ATR approach can be adapted for imagery of visual, infrared and SAR sensors because of the training-based classifiers of the ATR method. For the optimal adaptation of these classifiers they have to be trained with appropriate and sufficient image data. The training images must show the target objects from different aspect angles, ranges, environmental conditions, etc. Incomplete training sets lead to a degradation of classifier performance. Additionally, ground truth information i.e. scenario conditions like class type and position of targets is necessary for the optimal adaptation of the ATR method. In Summer 2003, EADS started a cooperation with Kongsberg Defence & Aerospace (KDA) from Norway. The EADS/KDA approach is to provide additional image data sets for training-based ATR through IR image simulation. The joint study aims to investigate the benefits of enhancing incomplete training sets for classifier adaptation by simulated synthetic imagery. EADS/KDA identified the requirements of a commercial-off-the-shelf IR simulation tool capable of delivering appropriate synthetic imagery for ATR development. A market study of available IR simulation tools and suppliers was performed. After that the most promising tool was benchmarked according to several criteria e.g. thermal emission model, sensor model, targets model, non-radiometric image features etc., resulting in a

  5. Metal oxide-coating PMMA or Talc as a new IR blocker inhibits IR-induced decrease of collagens in human dermal fibroblasts.

    Science.gov (United States)

    Nam, J-J; Lee, K-E; Kim, Y J

    2015-08-01

    The purpose of this study was whether P/M or T/M inhibits IR-induced decrease of collagens in human dermal fibroblasts, using P/M or T/M blocked near-IR (NIR) transmittance significantly in spectrophotometer measurement. As metal oxides are effective inorganic molecules for intercepting IR radiation, we have developed metal oxide-coating PMMA (P/M) or Talc (T/M) as a new IR blocker. Inhibitory effect of the new IR blocker on collagen degradation was measured by gene and protein expressions of procollagens and MMPs, respectively, in IR-irradiated Hs68 cell line. Using P/M or T/M inhibited IR-induced increases of MMP-1, MMP-3 and MMP-9, and IR-induced decreases of type 1 and 4 procollagen in a dose-dependent manner in dermal fibroblasts. In addition, using both P/M and T/M blocked the increase of cell media temperature induced by IR lamp. The results suggest that P/M or T/M can inhibit decrease of collagens by blocking IR-induced heat transmission in human dermal fibroblasts. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  6. Plk1 phosphorylation of IRS2 prevents premature mitotic exit via AKT inactivation

    Science.gov (United States)

    Chen, Long; Li, Zhiguo; Ahmad, Nihal; Liu, Xiaoqi

    2016-01-01

    Insulin receptor substrate (IRS) proteins play important roles by acting as a platform in transducing signals from transmembrane receptors upon growth factor stimulation. Although tyrosine phosphorylation on IRS proteins plays critical roles in signal transduction, phosphorylation of IRS proteins on serine/threonine residues are believed to play various regulatory roles on IRS protein function. However, studies on serine/threonine phosphorylation of IRS proteins are very limited, especially for insulin receptor substrate 2 (IRS2), one member of the IRS protein family. In this study, we identify Polo-like kinase 1 (Plk1) as the responsible kinase for phosphorylation of IRS2 on two serine residues, Ser 556 and Ser 1098. Phosphorylation of IRS2 on these two serine residues by Plk1 prevents the activation of the PI3K pathway upon growth factor stimulation by inhibiting the binding between IRS2 and the PI3K pathway components and increasing IRS2 protein degradation. Of significance, we show that IRS2 phosphorylation is cell cycle regulated and that Plk1 phosphorylation of IRS2 prevents premature mitotic exit via AKT inactivation. PMID:25830382

  7. (Ir)reconcilable differences? The debate concerning nursing and technology.

    Science.gov (United States)

    Sandelowski, M

    1997-01-01

    To review and critique the debate concerning nursing and technology. Technology has been considered both at one and at odds with nursing. Mitcham's (1994) concepts of technological optimism and romanticism. Nursing literature since 1960. Historical analysis. Technological optimists in nursing have viewed technology as an extension of and as readily assimilable into humanistic nursing practice, and nursing as socially advantaged by technology. Technological romantics have viewed technology as irreconcilable with nursing culture, as an expression of masculine culture, and as recirculating existing gender and social inequalities. Both optimists and romantics essentialize technology and nursing, treating the two as singular and fixed entities. The (ir)reconcilability of nursing and technology may be a function of how devices are used by people in different contexts, or of the (ir)reconcilability of views of technology in nursing.

  8. IR OPTICS MEASUREMENT WITH LINEAR COUPLING'S ACTION-ANGLE PARAMETERIZATION

    International Nuclear Information System (INIS)

    LUO, Y.; BAI, M.; PILAT, R.; SATOGATA, T.; TRBOJEVIC, D.

    2005-01-01

    A parameterization of linear coupling in action-angle coordinates is convenient for analytical calculations and interpretation of turn-by-turn (TBT) beam position monitor (BPM) data. We demonstrate how to use this parameterization to extract the twiss and coupling parameters in interaction regions (IRs), using BPMs on each side of the long IR drift region. The example of TBT BPM analysis was acquired at the Relativistic Heavy Ion Collider (RHIC), using an AC dipole to excite a single eigenmode. Besides the full treatment, a fast estimate of beta*, the beta function at the interaction point (IP), is provided, along with the phase advance between these BPMs. We also calculate and measure the waist of the beta function and the local optics

  9. Mid-IR laser system for advanced neurosurgery

    Science.gov (United States)

    Klosner, M.; Wu, C.; Heller, D. F.

    2014-03-01

    We present work on a laser system operating in the near- and mid-IR spectral regions, having output characteristics designed to be optimal for cutting various tissue types. We provide a brief overview of laser-tissue interactions and the importance of controlling certain properties of the light beam. We describe the principle of operation of the laser system, which is generally based on a wavelength-tunable alexandrite laser oscillator/amplifier, and multiple Raman conversion stages. This configuration provides robust access to the mid-IR spectral region at wavelengths, pulse energies, pulse durations, and repetition rates that are attractive for neurosurgical applications. We summarize results for ultra-precise selective cutting of nerve sheaths and retinas with little collateral damage; this has applications in procedures such as optic-nerve-sheath fenestration and possible spinal repair. We also report results for cutting cornea, and dermal tissues.

  10. Laser welding parameters for manufacturing iridium-192 (Ir-192) source

    International Nuclear Information System (INIS)

    Anung Pujiyanto; Moch Subechi; Hotman Lubis; Diandono KY

    2013-01-01

    Number of cervical cancer patients in Indonesia is growing every year. One of cervical cancer treatment was fairly effective use brachytherapy treatment with radioisotope sources of iridium-192. Manufacturing of iridium sources for brachytherapy can be done by incorporating the iridium-192 into stainless steel microcapsules then welding using laser welder which the quality of the welding of iridium source (Ir-192) was determined by the welding parameters such as full power, energy frequency, average power and speed. Based on the result of leakage test using pressure -20 inch Hg and tensile test 2.5 bar showed the welding parameters III and IV did not have leakage and damaged. So that parameters III and IV are recommended to be applied to Ir-192 HDR's source. (author)

  11. Photothermal IR spectroscopy with perforated membrane micromechanical resonators

    DEFF Research Database (Denmark)

    Kurek, Maksymilian

    wavelength corresponding to its specific molecular vibrations. This thermal energy heats the resonator and leads to its thermal expansion followed by a decrease of the tensile stress in the resonator. In turn it eventually causes the resonance frequency to shift towards lower values. However, further...... development of this approach was curbed by difficult and inefficient coupling of the IR light beam to a nanometer-sized resonator. In addition, readout of vibration was done by laser Doppler vibrometer, a precise but bulky and expensive instrument. These issues hindered a realworld application of the NAM......-IR method. In order to overcome them, string resonators were replaced by membranes. A reliable sampling technique was maintained by adding perforation to membranes and thereby essentially getting membrane porous filters. Membranes gave also access to fully integrated magnetic transduction that allowed...

  12. Photonics in nature: Yellowstone National Park in IR

    Science.gov (United States)

    Vollmer, Michael; Shaw, Joseph A.; Nugent, Paul W.; Harris, Wilson; Gillis, Kendra; Weiss, William; Carpenter, Logan; Carpenter, Amy; Scherrer, Bryan

    2017-08-01

    Infrared thermal imaging is a valuable tool not only in science but also in optics and photonics education and outreach activities. Observing natural optical phenomena in a different spectral region like the thermal infrared often offers new insights. The commonly used false color images not only allow extraction of useful information about thermal properties of objects, but they can also provide aesthetic sights and are thus an excellent tool for public outreach activities. Recently we have pursued this kind of study using IR imaging within Yellowstone National Park, complementing earlier work on thermal pool colors and spectroscopy. We will discuss and compare images of a variety of VIS and IR cameras of hot springs, geysers, mud pools and other natural phenomena recorded in the park during 2012 and 2016.

  13. IR-ATR investigation of surface anisotropy in silicate glasses

    Science.gov (United States)

    Ivanovski, Vladimir; Mayerhöfer, Thomas G.; Kriltz, Antje; Popp, Jürgen

    2017-02-01

    Several samples of flat soda-lime silicate glass were investigated by the Infrared Attenuated Total Reflection (IR-ATR) spectroscopy technique. The specular reflectance spectra together with the results of the performed dispersion analysis and the generated reflectance spectra, using Fresnel equations, suggest that the samples are isotropic. In contrast, spectra recorded by the ATR technique suggest an anisotropic structure on the surface of the specimen different from that in the bulk. This is established through differences in the s- and p-polarized IR-ATR spectra, which cannot be simply transformed into one another employing Fresnel formula for an isotropic case. It appears that this thin film having a structure different from the bulk is larger than the ATR effective penetration depth of the evanescent ray for each incidence angle above the critical one. The investigation suggests C2 symmetry of the SiO4 unit.

  14. From UV/IR mixing to closed strings

    International Nuclear Information System (INIS)

    Lopez, Esperanza

    2003-01-01

    It was shown in [1] that the leading UV/IR mixing effects in noncommutative gauge theories on D-branes are able to capture information about the closed string spectrum of the parent string theory. The analysis was carried out for D-branes on nonsupersymmetric C 3 /Z N orbifolds of Type IIB. In this paper we consider D-branes on twisted circles compactifications of Type II string theory. We find that the signs of the leading UV/IR mixing effects know about the (mass) 2 gap between the lowest modes in NSNS and RR closed string towers. Moreover, the relevant piece of the field theory effective action can be reproduced purely in the language of closed strings. Remarkably, this approach unifies in a single structure, that of a closed string exchange between D-branes, both the leading planar and nonplanar effects associated to the absence of supersymmetry. (author)

  15. Applications of FT-IR spectrophotometry in cancer diagnostics.

    Science.gov (United States)

    Bunaciu, Andrei A; Hoang, Vu Dang; Aboul-Enein, Hassan Y

    2015-01-01

    This review provides a brief background to the application of infrared spectroscopy, including Fourier transform-infrared spectroscopy, in biological fluids. It is not meant to be complete or exhaustive but to provide the reader with sufficient background for selected applications in cancer diagnostics. Fourier transform-infrared spectroscopy (FT-IR) is a fast and nondestructive analytical method. The infrared spectrum of a mixture serves as the basis to quantitate its constituents, and a number of common clinical chemistry tests have proven to be feasible using this approach. This review focuses on biomedical FT-IR applications, published in the period 2009-2013, used for early detection of cancer through qualitative and quantitative analysis.

  16. Thermal IR exitance model of a plant canopy

    Science.gov (United States)

    Kimes, D. S.; Smith, J. A.; Link, L. E.

    1981-01-01

    A thermal IR exitance model of a plant canopy based on a mathematical abstraction of three horizontal layers of vegetation was developed. Canopy geometry within each layer is quantitatively described by the foliage and branch orientation distributions and number density. Given this geometric information for each layer and the driving meteorological variables, a system of energy budget equations was determined and solved for average layer temperatures. These estimated layer temperatures, together with the angular distributions of radiating elements, were used to calculate the emitted thermal IR radiation as a function of view angle above the canopy. The model was applied to a lodgepole pine (Pinus contorta) canopy over a diurnal cycle. Simulated vs measured radiometric average temperatures of the midcanopy layer corresponded with 2 C. Simulation results suggested that canopy geometry can significantly influence the effective radiant temperature recorded at varying sensor view angles.

  17. Vibrational microspectroscopy of food. Raman vs. FT-IR

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Løkke, Mette Marie; Micklander, Elisabeth

    2003-01-01

    FT-IR and Raman spectroscopy are complementary techniques for the study of molecular vibrations and structure. The combination with a microscope results in an analytical method that allows spatially resolved investigation of the chemical composition of heterogeneous foods and food ingredients...... to different heterogeneous food systems. FT-IR and Raman microspectroscopy were applied to a number of different problems related to food analysis: (1) in situ determination of starch and pectin in the potato cell, (2) in situ determination of the distribution of amygdalin in bitter almonds, (3......) the composition of blisters found on the surface of bread, (4) the microstructure of high-lysine barley and (5) the composition of white spots in the shell of frozen shrimps. (C) 2003 Elsevier Science Ltd. All rights reserved....

  18. IR-laser assisted additive freeform optics manufacturing.

    Science.gov (United States)

    Hong, Zhihan; Liang, Rongguang

    2017-08-02

    Computer-controlled additive manufacturing (AM) processes, also known as three-dimensional (3D) printing, create 3D objects by the successive adding of a material or materials. While there have been tremendous developments in AM, the 3D printing of optics is lagging due to the limits in materials and tight requirements for optical applicaitons. We propose a new precision additive freeform optics manufacturing (AFOM) method using an pulsed infrared (IR) laser. Compared to ultraviolet (UV) curable materials, thermally curable optical silicones have a number of advantages, such as strong UV stability, non-yellowing, and high transmission, making it particularly suitable for optical applications. Pulsed IR laser radiation offers a distinct advantage in processing optical silicones, as the high peak intensity achieved in the focal region allows for curing the material quickly, while the brief duration of the laser-material interaction creates a negligible heat-affected zone.

  19. Divertor IR thermography on Alcator C-Moda)

    Science.gov (United States)

    Terry, J. L.; LaBombard, B.; Brunner, D.; Payne, J.; Wurden, G. A.

    2010-10-01

    Alcator C-Mod is a particularly challenging environment for thermography. It presents issues that will similarly face ITER, including low-emissivity metal targets, low-Z surface films, and closed divertor geometry. In order to make measurements of the incident divertor heat flux using IR thermography, the C-Mod divertor has been modified and instrumented. A 6° toroidal sector has been given a 2° toroidal ramp in order to eliminate magnetic field-line shadowing by imperfectly aligned divertor tiles. This sector is viewed from above by a toroidally displaced IR camera and is instrumented with thermocouples and calorimeters. The camera provides time histories of surface temperatures that are used to compute incident heat-flux profiles. The camera sensitivity is calibrated in situ using the embedded thermocouples, thus correcting for changes and nonuniformities in surface emissivity due to surface coatings.

  20. IR-stimulated visible fluorescence in pink and brown diamond

    International Nuclear Information System (INIS)

    Byrne, K S; Luiten, A N; Chapman, J G

    2014-01-01

    Irradiation of natural pink and brown diamond by middle-ultraviolet light (photon energy ϵ ≥ 4.1 eV ) is seen to induce anomalous fluorescence phenomena at N3 defect centres (structure N 3 −V). When diamonds primed in this fashion are subsequently exposed to infrared light (even with a delay of many hours), a transient burst of blue N3 fluorescence is observed. The dependence of this IR-triggered fluorescence on pump wavelength and intensity suggest that this fluorescence phenomena is intrinsically related to pink diamond photochromism. An energy transfer process between N3 defects and other defect species can account for both the UV-induced fluorescence intensity changes, and the apparent optical upconversion of IR light. From this standpoint, we consider the implications of this N3 fluorescence behaviour for the current understanding of pink diamond photochromism kinetics. (paper)

  1. Laser Spark Formamide Decomposition Studied by FT-IR Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Ferus, Martin; Kubelík, Petr; Civiš, Svatopluk

    2011-01-01

    Roč. 115, č. 44 (2011), s. 12132-12141 ISSN 1089-5639 R&D Projects: GA AV ČR IAA400400705; GA AV ČR IAAX00100903; GA ČR GAP208/10/2302 Institutional research plan: CEZ:AV0Z40400503 Keywords : FT-IR spectroscopy * high-power laser * induced dielectric-breakdown Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.946, year: 2011

  2. US-LARP progress on LHC IR upgrades

    CERN Document Server

    Sen, Tanaji; Mokhov, Nikolai; Fischer, Wolfram; Gupta, Ramesh; Qiang, Ji

    2006-01-01

    We review the progress on LHC IR upgrades made by the US-LARP collaboration since the last CARE meeting in November 2004. We introduce a new optics design with doublet focusing, and discuss energy deposition calculations with an open mid-plane dipole. We present the results of a beam-beam experiment at RHIC. This experiment was the first phase of a planned test of the wire compensation principle at RHIC.

  3. MTF measurement of IR optics in different temperature ranges

    Science.gov (United States)

    Bai, Alexander; Duncker, Hannes; Dumitrescu, Eugen

    2017-10-01

    Infrared (IR) optical systems are at the core of many military, civilian and manufacturing applications and perform mission critical functions. To reliably fulfill the demanding requirements imposed on today's high performance IR optics, highly accurate, reproducible and fast lens testing is of crucial importance. Testing the optical performance within different temperature ranges becomes key in many military applications. Due to highly complex IR-Applications in the fields of aerospace, military and automotive industries, MTF Measurement under realistic environmental conditions become more and more relevant. A Modulation Transfer Function (MTF) test bench with an integrated thermal chamber allows measuring several sample sizes in a temperature range from -40 °C to +120°C. To reach reliable measurement results under these difficult conditions, a specially developed temperature stable design including an insulating vacuum are used. The main function of this instrument is the measurement of the MTF both on- and off-axis at up to +/-70° field angle, as well as measurement of effective focal length, flange focal length and distortion. The vertical configuration of the system guarantees a small overall footprint. By integrating a high-resolution IR camera with focal plane array (FPA) in the detection unit, time consuming measurement procedures such as scanning slit with liquid nitrogen cooled detectors can be avoided. The specified absolute accuracy of +/- 3% MTF is validated using internationally traceable reference optics. Together with a complete and intuitive software solution, this makes the instrument a turn-key device for today's state-of- the-art optical testing.

  4. IR Spectra and Bond Energies Computed Using DFT

    Science.gov (United States)

    Bauschlicher, Charles; Andrews, Lester; Arnold, James (Technical Monitor)

    2000-01-01

    The combination of density functional theory (DFT) frequencies and infrared (IR) intensities and experimental spectra is a very powerful tool in the identification of molecules and ions. The computed and measured isotopic ratios make the identification much more secure than frequencies and intensities alone. This will be illustrated using several examples, such as Mn(CO)n and Mn(CO)n-. The accuracy of DFT metal-ligand bond energies will also be discussed.

  5. IR Camera Report for the 7 Day Production Test

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-22

    The following report gives a summary of the IR camera performance results and data for the 7 day production run that occurred from 10 Sep 2015 thru 16 Sep 2015. During this production run our goal was to see how well the camera performed its task of monitoring the target window temperature with our improved alignment procedure and emissivity measurements. We also wanted to see if the increased shielding would be effective in protecting the camera from damage and failure.

  6. Adsorbed or intercalated: Na on graphene/Ir(111)

    Science.gov (United States)

    Pervan, Petar; Lazić, Predrag

    2017-09-01

    Interaction of sodium with graphene (Gr) on Ir(111) was studied with the aim to resolve the issue of Na adsorption/intercalation kinetics. The system Na/Gr/Ir(111) was studied by means of angle-resolved photoemission spectroscopy, low-energy electron diffraction, and ab initio density functional theory (DFT) calculation. It has been found that at room temperature (RT) and low concentrations Na is dominantly adsorbed on graphene. At higher concentrations, an intercalation process sets in so that it is possible to observe the coexistence of these two states. Eventually, all Na atoms are found in the intercalated state as determined by exposure to oxygen. While adsorption of Na on graphene already intercalated by Na [Na/Gr/Na/Ir(111) system] at RT was not possible, we could observe Li adsorption through the increase of Dirac point binding energy. Li coadsorption strongly affects the binding energy of the iridium surface state as well. This finding was supported by DFT calculations of adsorption energy of Na and Li on bare and fully Na intercalated graphene.

  7. Structure and linear spectroscopic properties of near IR polymethine dyes

    International Nuclear Information System (INIS)

    Webster, Scott; Padilha, Lazaro A.; Hu Honghua; Przhonska, Olga V.; Hagan, David J.; Van Stryland, Eric W.; Bondar, Mikhail V.; Davydenko, Iryna G.; Slominsky, Yuriy L.; Kachkovski, Alexei D.

    2008-01-01

    We performed a detailed experimental investigation and quantum-chemical analysis of a new series of near IR polymethine dyes with 5-butyl-7,8-dihydrobenzo[cd]furo[2,3-f]indolium terminal groups. We also synthesized and studied two neutral dyes, squaraine and tetraone, with the same terminal groups and performed a comparison of the spectroscopic properties of this set of 'near IR' dyes (polymethine, squaraine, and tetraone) with an analogous set of 'visible' dyes with simpler benzo[e]indolium terminal groups. From these measurements, we find that the dyes with dihydrobenzo[cd]furo[2,3-f]indolium terminal groups are characterized by a remarkably large shift ∼300 nm (∼200 nm for tetraone) of their absorption bands towards the red region. We discuss the difference in electronic structure for these molecules and show that the 'near IR' dyes are characterized by an additional weak fluorescence band from the higher lying excited states connected with the terminal groups. Absorption spectra for the longest polymethines are solvent-dependent and are characterized by a broadening of the main band in polar solvents, which is explained by ground state symmetry breaking and reduced charge delocalization within the polymethine chromophore. The results of these experiments combined with the agreement of quantum chemical calculations moves us closer to a predictive capability for structure-property relations in cyanine-like molecules

  8. Power-Law Template for IR Point Source Clustering

    Science.gov (United States)

    Addison, Graeme E.; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark; Halpern, Mark; Hincks, Adam; Hlozek, Renee; hide

    2011-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217,353,545 and 857 GHz, over angular scales 100 law of the form C_l\\propto I(sup -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, nu(sup beta) B(nu,T_eff), with a single emissivity index beta = 2.20 +/- 0.07 and effective temperature T_eff= 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha_150-220 = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in Cosmic Microwave Background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  9. Revenue Potential for Inpatient IR Consultation Services: A Financial Model.

    Science.gov (United States)

    Misono, Alexander S; Mueller, Peter R; Hirsch, Joshua A; Sheridan, Robert M; Siddiqi, Assad U; Liu, Raymond W

    2016-05-01

    Interventional radiology (IR) has historically failed to fully capture the value of evaluation and management services in the inpatient setting. Understanding financial benefits of a formally incorporated billing discipline may yield meaningful insights for interventional practices. A revenue modeling tool was created deploying standard financial modeling techniques, including sensitivity and scenario analyses. Sensitivity analysis calculates revenue fluctuation related to dynamic adjustment of discrete variables. In scenario analysis, possible future scenarios as well as revenue potential of different-size clinical practices are modeled. Assuming a hypothetical inpatient IR consultation service with a daily patient census of 35 patients and two new consults per day, the model estimates annual charges of $2.3 million and collected revenue of $390,000. Revenues are most sensitive to provider billing documentation rates and patient volume. A range of realistic scenarios-from cautious to optimistic-results in a range of annual charges of $1.8 million to $2.7 million and a collected revenue range of $241,000 to $601,000. Even a small practice with a daily patient census of 5 and 0.20 new consults per day may expect annual charges of $320,000 and collected revenue of $55,000. A financial revenue modeling tool is a powerful adjunct in understanding economics of an inpatient IR consultation service. Sensitivity and scenario analyses demonstrate a wide range of revenue potential and uncover levers for financial optimization. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

  10. Electromagnetic properties of 181Ir: Evidence of β-stretching?

    International Nuclear Information System (INIS)

    Garg, U.; Reviol, W.; Semmes, P.

    1991-01-01

    We have calculated the B(Ml)/B(E2) ratios in 18l Ir within a shape-fixed particle + rotor model, in order to investigate how sensitive these may be to the nuclear shapes under consideration, and whether or not there is evidence of shape coexistence in the electromagnetic data alone. The model calculations employed the same Woods-Saxon potential that has been used previously for TRS and bandhead calculations and all parameters have been taken at their standard values, without any adjustments. To the extent possible with present models, these calculations should represent predictions for the B(M1)/B(E2) ratios at the deformations expected from the TRS and bandhead calculations. A comparison with the 181 Ir data is stimulated by the fact that this is the lightest-mass Ir nucleus for which the spins and parities am firmly established experimentally; we find that the electromagnetic transition rates in this nucleus are well reproduced under the assumption of a single, fixed shape

  11. A multistage target tracker in IR image sequences

    Science.gov (United States)

    Huang, Qiao; Yang, Jie

    2014-07-01

    In this paper, we propose a robust approach for tracking target in forward looking infrared imagery taken from an airborne moving platform. The tracker is proposed in a two stage algorithm with a coarse to fine manner. First, we introduce a coarse but quick algorithm to roughly locate the target, which based on a model matching procedure by computing the SIFT vector of the target. The raw position and the size of the target are then used to initialize the multistage tracking algorithm. Second, the target's position is refined through a dedicated localization algorithm, which based on a HOG feature tracking procedure to overcome the rapid size and angel changes of the dim target in the IR image sequence. Finally, the target's model can automatically been updated and utilized in the first stage. As confirmed by experimental results on a variety of IR image sequences, the proposed approach efficiently and robustly tracks target under challenging environmental conditions. Moreover, the speed of the multistage algorithm is also convincing in the tested IR imagery.

  12. The IR Sector – Opening new horizons for CERN

    CERN Multimedia

    2016-01-01

    Last week saw the CERN family grow by one, as we welcomed Cyprus as an Associate Member in the pre-stage to Membership. This gives me a good opportunity, three months into the job, to share the vision for the new International Relations (IR) Sector. CERN is and always has been an incredible example of successful, inclusive international collaboration and exchange in the pursuit of common goals. The IR Sector continues and builds on that tradition and spirit.   In the 60-plus years of CERN’s existence, our world has been transformed at all levels. And over the last decade or so, the world of particle physics has evolved beyond recognition. CERN is now a global lab, with a European core, and particle physics is a field that is increasingly planned and coordinated around the world. It is for these reasons that CERN needs to develop its International Relations so we can respond to and navigate these changes. The establishment by the Director-General of the IR Sector is a sign of her commitm...

  13. Near-IR Explorations of Buried AGN in Advanced Mergers

    Science.gov (United States)

    Ferguson, Jason; Constantin, Anca; Satyapal, Shobita; Rothberg, Barry

    2018-01-01

    Close separation dual AGNs provide unambiguous confirmation of ongoing mergers where the black holes experience their most rapid growth. Most of these systems have been discovered serendipitously, and confirmed cases remain, however, extremely rare. We present here the results of the analysis of new near-IR spectroscopy of nine advanced merger systems that display mid-IR colors suggestive of AGNs while lacking signatures of activity in the optical. Using the Large Binocular Telescope's LUCI (LBT Utility Camera for Infrared) 1 & 2 spectrographs we confirm the presence of broadened and/or high-excitation lines indicative of powerful AGN, reveal signs of hidden AGN feedback in the form of kinematic outflows, measure the properties of the host stellar populations, and begin to probe the gas-metallicities in these systems. Our results yield critical evidence that the epoch of peak black hole growth in mergers occurs in a highly obscured phase, consistent with theoretical predictions. We also confirm the effectiveness of using mid-IR colors as a pre-selection technique to identify dual AGN systems. This is one of the first detailed investigations into the physical environment of optically obscured dual AGNs, and provides key indications for finding and characterizing elusive black hole accretion.

  14. Anisotropic Magnetoresistance in Antiferromagnetic Sr_{2}IrO_{4}

    Directory of Open Access Journals (Sweden)

    C. Wang

    2014-11-01

    Full Text Available We report point-contact measurements of anisotropic magnetoresistance (AMR in a single crystal of antiferromagnetic Mott insulator Sr_{2}IrO_{4}. The point-contact technique is used here as a local probe of magnetotransport properties on the nanoscale. The measurements at liquid nitrogen temperature reveal negative magnetoresistances (up to 28% for modest magnetic fields (250 mT applied within the IrO_{2} a-b plane and electric currents flowing perpendicular to the plane. The angular dependence of magnetoresistance shows a crossover from fourfold to twofold symmetry in response to an increasing magnetic field with angular variations in resistance from 1% to 14%. We tentatively attribute the fourfold symmetry to the crystalline component of AMR and the field-induced transition to the effects of applied field on the canting of antiferromagnetic-coupled moments in Sr_{2}IrO_{4}. The observed AMR is very large compared to the crystalline AMRs in 3d transition metal alloys or oxides (0.1%–0.5% and can be associated with the large spin-orbit interactions in this 5d oxide while the transition provides evidence of correlations between electronic transport, magnetic order, and orbital states. The finding of this work opens an entirely new avenue to not only gain a new insight into physics associated with spin-orbit coupling but also to better harness the power of spintronics in a more technically favorable fashion.

  15. Media handling for visual information retrieval in VizIR

    Science.gov (United States)

    Eidenberger, Horst

    2003-06-01

    This paper describes how the handling of visual media objects is implemented in the visual information retrieval project VizIR. Essentially, four areas are concerned: media access, media representation in user interfaces, visualisation of media-related data and media transport over the network. The paper offers detailed technical descriptions of the solutions developed in VizIR for these areas. Unified media access for images and video is implemented through class MediaContent. This class contains methods to access the view on a media object at any point in time as well as methods to change the colour model and read/write format parameters (size, length, frame-rate). Based on this low-level-API class VisualCube allows accessing spatio-temporal areas in temporal media randomly. Transformer-classes allow to modify visual objects in a very simple but effective way. Visualisation of media object is implemented in class MediaRenderer. Each MediaRenderer represents one media object and is responsible for any aspect of its visualisation. In the paper examples for reasonable implementations of MediaRenderer-classes are presented. Visualisation of media-related data is strongly connected to MediaRenderer. MediaRenderer is to a large extent responsible for displaying visual panels created by other framework components. Finally, media object transport in VizIR is based on the Realtime Transfer Protocol (for media objects) and XML-messaging (for XML-data).

  16. Will IR Staff Stick? An Exploration of Institutional Researchers' Intention to Remain in or Leave Their Jobs

    Science.gov (United States)

    Knight, William E.; Leimer, Christina L.

    2010-01-01

    The study explored the factors that relate to the likelihood of institutional researchers (IRs) to plan to leave their jobs. Learning more about the effects on IR job turnover can serve to improve the employment experience of IR practitioners, the profession of IR, and, indirectly, higher education. 1,264 IRs responded to a national survey…

  17. Tax Administration: IRS's Innocent Spouse Program Performance Improved; Balanced Performance Measures Needed

    National Research Council Canada - National Science Library

    2002-01-01

    .... Under the Internal Revenue Services (IRS) Innocent Spouse Program, IRS can relieve taxpayers of tax debts on the basis of equity considerations, such as not knowing that their spouse failed to pay taxes due...

  18. Tax Administration: Information on Selected IRS Tax Enforcement and Collection Efforts

    National Research Council Canada - National Science Library

    2001-01-01

    ...) in enforcing the nation's tax laws. These two topics will be discussed: (1) the relationship between IRS audits of taxpayers and other programs IRS uses to ensure that taxpayers returns are accurate, and (2...

  19. Detectors with Improved Near-to-Mid IR Performance and Reduced Cooling Requirements, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR Phase I proposal addresses a NASA need for improved near-to-mid IR detectors for imaging and spectroscopy. High performance IR detectors with cutoff...

  20. Statewide implementation of Pave-IR in the Texas Department of Transportation.

    Science.gov (United States)

    2012-02-01

    This project conducted work to complement implementation of Pave-IR into the Texas Department of : Transportations hot-mix-asphalt quality control/quality assurance specification. Pave-IR provides real-time : thermal profiling of paving operations...

  1. The use of IAEA-IRS information in Russia's nuclear power industry

    International Nuclear Information System (INIS)

    1996-01-01

    The use of IAEA-IRS information in Russia's nuclear power industry is described, including the following issues: organizational aspects; organization of the information process; assessment of information uses; examples of using IAEA-IRS information. Figs

  2. Fourier Transform Infrared Spectroscopy: Part II. Advantages of FT-IR.

    Science.gov (United States)

    Perkins, W. D.

    1987-01-01

    This is Part II in a series on Fourier transform infrared spectroscopy (FT-IR). Described are various advantages of FT-IR spectroscopy including energy advantages, wavenumber accuracy, constant resolution, polarization effects, and stepping at grating changes. (RH)

  3. Tax Administration: IRS Should Evaluate the Changes to Its Offer in Compromise Program

    National Research Council Canada - National Science Library

    2002-01-01

    ...), the demand for offers has increased significantly. Even though IRS added staff to the program, the inventory of unresolved offers and the processing times have grown. IRS now takes about 10 months, on average, to make an offer determination.

  4. Research into the usage of integrated jamming of IR weakening and smoke-screen resisting the IR imaging guided missiles

    Science.gov (United States)

    Wang, Long-tao; Jiang, Ning; Lv, Ming-shan

    2015-10-01

    With the emergence of the anti-ship missle with the capability of infrared imaging guidance, the traditional single jamming measures, because of the jamming mechanism and technical flaws or unsuitable use, greatly reduced the survival probability of the war-ship in the future naval battle. Intergrated jamming of IR weakening + smoke-screen Can not only make jamming to the search and tracking of IR imaging guidance system , but also has feasibility in conjunction, besides , which also make the best jamming effect. The research conclusion has important realistic meaning for raising the antimissile ability of surface ships. With the development of guidance technology, infrared guidance system has expanded by ir point-source homing guidance to infrared imaging guidance, Infrared imaging guidance has made breakthrough progress, Infrared imaging guidance system can use two-dimensional infrared image information of the target, achieve the precise tracking. Which has Higher guidance precision, better concealment, stronger anti-interference ability and could Target the key parts. The traditional single infrared smoke screen jamming or infrared decoy flare interference cannot be imposed effective interference. So, Research how to effectively fight against infrared imaging guided weapons threat measures and means, improving the surface ship antimissile ability is an urgent need to solve.

  5. Semiclassical relations and IR effects in de Sitter and slow-roll space-times

    DEFF Research Database (Denmark)

    B. Giddings, Steven; Sloth, Martin Snoager

    2010-01-01

    We calculate IR divergent graviton one-loop corrections to scalar correlators in de Sitter space, and show that the leading IR contribution may be reproduced via simple semiclassical consistency relations. One can likewise use such semiclassical relations to calculate leading IR corrections to co...... with a sharp perturbative calculation of "missing information" in Hawking radiation....

  6. Manual for IRS Coding. Joint IAEA/NEA International Reporting System for Operating Experience

    International Nuclear Information System (INIS)

    2011-01-01

    The International Reporting System for Operating Experience (IRS) is jointly operated by the International Atomic Energy Agency (IAEA) and the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD/NEA). In early 2010, the IAEA and OECD/NEA jointly issued the IRS Guidelines, which described the reporting system and process and gave users the necessary elements to enable them to produce IRS reports to a high standard of quality while retaining the effectiveness of the system expected by all Member States operating nuclear power plants. The purpose of the present Manual for IRS Coding is to provide supplementary guidance specifically on the coding element of IRS reports to ensure uniform coding of events that are reported through IRS. This Coding Manual does not supersede the IRS Guidelines, but rather, supports users and preparers in achieving a consistent and high level of quality in their IRS reports. Consistency and high quality in the IRS reports allow stakeholders to search and retrieve specific event information with ease. In addition, well-structured reports also enhance the efficient management of the IRS database. This Coding Manual will give specific guidance on the application of each section of the IRS codes, with examples where necessary, of when and how these codes are to be applied. As this reporting system is owned by the Member States, this manual has been developed and approved by the IRS National Coordinators with the assistance of the IAEA and NEA secretariats

  7. MODIS_AQUA_L3_SST_MID-IR_ANNUAL_4KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  8. MODIS_TERRA_L3_SST_MID-IR_MONTHLY_9KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  9. A Prospective Cohort Study on IRS Gene Polymorphisms in Type 2 ...

    African Journals Online (AJOL)

    Insulin resistance status was determined using the homeostatic model assessment for insulin resistance (HOMA-IR) index. Results: IRS1 polymorphisms were associated with increased insulin resistance (X2 = 5.09, p = 0.023) in T2DM patients with severe/acute hyperglycemia. IRS2 polymorphisms were not associated with ...

  10. DFT study of the structure, chemical ordering and molecular adsorption of Pd-Ir nanoalloys.

    Science.gov (United States)

    Fan, Tian-E; Demiroglu, Ilker; Hussein, Heider A; Liu, Tun-Dong; Johnston, Roy L

    2017-10-11

    The structures and surface adsorption sites of Pd-Ir nanoalloys are crucial to the understanding of their catalytic performance because they can affect the activity and selectivity of nanocatalysts. In this article, density functional theory (DFT) calculations are performed on bare Pd-Ir nanoalloys to systematically explore their stability and chemical ordering properties, before studying the adsorption of CO on the nanoalloys. First, the structural stability of 38-atom and 79-atom truncated octahedral (TO) Pd-Ir nanoalloys are investigated. Then the adsorption properties and preferred adsorption sites of CO on 38-atom Pd-Ir nanoalloys are considered. The Pd shell Ir core structure, which has the lowest energy of all the considered isomers, exhibits the highest structural stability, while the Pd core Ir shell configuration is the least stable. In addition, the adsorption strength of CO on Ir atoms is found to be greater than on Pd for Pd-Ir nanoclusters. The preferred adsorption sites of CO on pure Pd and Ir clusters are in agreement with calculations and experiments on extended Pd and Ir surfaces. In addition, d-band center and charge effects on CO adsorption strength on Pd-Ir nanoalloys are analyzed by comparison with pure clusters. The study provides a valuable theoretical insight into catalytically active Pd-Ir nanoalloys.

  11. MODIS_TERRA_L3_SST_MID-IR_ANNUAL_4KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  12. MODIS_AQUA_L3_SST_MID-IR_MONTHLY_9KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  13. MODIS_TERRA_L3_SST_MID-IR_8DAY_9KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  14. MODIS_TERRA_L3_SST_MID-IR_MONTHLY_4KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  15. MODIS_AQUA_L3_SST_MID-IR_DAILY_9KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  16. MODIS_TERRA_L3_SST_MID-IR_ANNUAL_9KM_NIGHTTIME:1

    Data.gov (United States)

    National Aeronautics and Space Administration — SST is derived from the MODIS IR channels using two channels in either the thermal IR (11-12 um) or channels in the mid-IR region (3.8-4.1 um). The approach is...

  17. IR spectroscopy of isolated neutral and protonated adenine and 9-methyladenine

    NARCIS (Netherlands)

    van Zundert, G. C. P.; Jaeqx, S.; Berden, G.; Bakker, J.M.; Kleinermanns, K.; Oomens, J.; Rijs, A.M.

    2011-01-01

    IR spectroscopy is employed to study isolated adenine and its derivative 9-methyladenine in both their neutral and protonated forms. The IR spectra of neutral adenine and 9-methyladenine are measured in a molecular beam expansion via IR-UV ion-dip spectroscopy in the 525 to 1750 cm−1 region. For

  18. IR Spectroscopy of Isolated Neutral and Protonated Adenine and 9-Methyladenine

    NARCIS (Netherlands)

    van Zundert, G. C. P.; Jaeqx, S.; G. Berden,; Bakker, J. M.; Kleinermanns, K.; Oomens, J.; Rijs, A. M.

    2011-01-01

    IR spectroscopy is employed to study isolated adenine and its derivative 9-methyladenine in both their neutral and protonated forms. The IR spectra of neutral adenine and 9-methyladenine are measured in a molecular beam expansion via IR-UV ion-dip spectroscopy in the 525 to 1750 cm(-1) region. For

  19. Comparative study of potentially J{sub eff} = 0 ground state iridium(V) in SrLaNiIrO{sub 6}, SrLaMgIrO{sub 6}, and SrLaZnIrO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Klaus K.; Agrestini, Stefano; Tjeng, Liu Hao [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Tanaka, Arata [Department of Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima (Japan); Jansen, Martin [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Max Planck Institute for Solid State Research, Stuttgart (Germany)

    2017-12-13

    A series of polycrystalline double perovskites SrLaBIrO{sub 6} (B = Ni, Mg, Zn) containing Ir{sup 5+} (5d{sup 4}) was synthesized by solid state reactions, and structural, magnetic and electronic properties were investigated. The isotypic fully ordered double perovskites crystallize in space group P2{sub 1}/n and show semiconducting behavior with estimated bandgaps of approximately 0.2 eV for SrLaNiIrO{sub 6} and SrLaZnIrO{sub 6}, and 0.4 eV for SrLaMgIrO{sub 6}. SrLaNiIrO{sub 6} is an antiferromagnet with a Neel temperature of 74 K (μ{sub eff} = 3.3 μ{sub B}, θ{sub W} = -90 K), whereas SrLaMgIrO{sub 6} and SrLaZnIrO{sub 6} are weakly paramagnetic. All title compounds exhibit a temperature-independent contribution to the measured magnetic susceptibility, which supports the notion for a van-Vleck-type response originating from the Ir{sup 5+} (5d{sup 4}, J{sub eff} = 0) ions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. The effect of interligand energy transfer on the emission spectra of heteroleptic Ir complexes.

    Science.gov (United States)

    Cho, Yang-Jin; Kim, So-Yoen; Son, Ho-Jin; Cho, Dae Won; Kang, Sang Ook

    2017-03-29

    In order to understand the causes of the emission shape and colour changes of heteroleptic Ir 3+ complexes containing 2-(2,4-difluorophenyl)pyridine (dfppy) as the main ligands, we introduced two types of ancillary ligands: (1) non-luminescent ancillary ligands, namely tetrakis(pyrazolyl)borate (bor) and picolinate (pic), which were employed for the preparation of Ir(dfppy) 2 (bor) and Ir(dfppy) 2 (pic), respectively, and (2) luminescent ancillary ligands, namely 1,10-phenanthroline (phen), bipyridine (bpy), and 2,3-dipyridylpyrazine (dpp), which were employed for the preparation of Ir(dfppy) 2 (phen), Ir(dfppy) 2 (bpy), and Ir(dfppy) 2 (dpp), respectively. In a glassy matrix at 77 K, the Ir complexes showed well-structured emission spectra, except Ir(dfppy) 2 (dpp). The vibronic structures in the emission spectra of Ir(dfppy) 2 (bor) and Ir(dfppy) 2 (pic) were maintained even at 300 K. However, Ir(dfppy) 2 (phen), Ir(dfppy) 2 (bpy), and Ir(dfppy) 2 (dpp) showed markedly red-shifted and broad emission spectra. The anomalous rigidochromism was attributed to an interligand energy transfer (ILET), and showed a strong temperature dependence. The excited states of dfppy are higher than those of phen, bpy, and dpp; thus, ILET occurs from dfppy to the other ligands lying in lower energy states. The ILET dynamics were probed directly using femtosecond transient absorption (TA) spectroscopy after the excitation of dfppy. As the time delay increased, the intensity of the TA band of dfppy decreased, while those of the bands related to the phen, bpy, and dpp ancillary ligands increased. On the other hand, no changes in the TA spectra were observed for Ir(dfppy) 2 (bor) and Ir(dfppy) 2 (pic). The TA spectral behaviours can be explained in terms of the relative ordering of the emissive states for cyclometalating and ancillary ligands.

  1. Study on seasonal IR signature change of a ship by considering seasonal marine environmental conditions

    Science.gov (United States)

    Kim, Do-Hwi; Han, Kuk-Il; Choi, Jun-Hyuk; Kim, Tae-Kuk

    2017-05-01

    Infrared (IR) signal emitted from objects over 0 degree Kelvin has been used to detect and recognize the characteristics of those objects. Recently more delicate IR sensors have been applied for various guided missiles and they affect a crucial influence on object's survivability. Especially, in marine environment it is more vulnerable to be attacked by IR guided missiles since there are nearly no objects for concealment. To increase the survivability of object, the IR signal of the object needs to be analyzed properly by considering various marine environments. IR signature of a naval ship consists of the emitted energy from ship surface and the reflected energy by external sources. Surface property such as the emissivity and the absorptivity on the naval ship varies with different paints applied on the surface and the reflected IR signal is also affected by the surface radiative property, the sensor's geometric position and various climatic conditions in marine environment. Since the direct measurement of IR signal using IR camera is costly and time consuming job, computer simulation methods are developing rapidly to replace those experimental tasks. In this study, we are demonstrate a way of analyzing the IR signal characteristics by using the measured background IR signals using an IR camera and the estimated target IR signals from the computer simulation to find the seasonal trends of IR threats of a naval ship. Through this process, measured weather data are used to analyze more accurate IR signal conditions for the naval ship. The seasonal change of IR signal contrast between the naval ship and the marine background shows that the highest contrast radiant intensity (CRI) value is appeared in early summer.

  2. NO Reactions Over Ir-Based Catalysts in the Presence of O2

    Directory of Open Access Journals (Sweden)

    Mingxin Guo

    2011-01-01

    Full Text Available The behaviour of a series of Ir-based catalysts supported on SiO2, ZSM-5 and γ-Al2O3 with various Ir loadings prepared by impregnation method was conducted by temperature programmed reaction (TPR technique. The result implies that NO is oxidized to NO2 while simultaneously being reduced to N2 or N2O in the NO reactions over iridium catalysts. The surface active phase over iridium catalysts that promote the NO reactions is IrO2. The catalytic activity increases with the increase of the Ir loading and support materials have a little effect on the catalytic activity. When the loading is less than 0.1%, the catalytic activity was found to be dependent on the nature of support materials and in order: Ir/ZSM-5>Ir/γ-Al2O3>Ir/SiO2. When the loading is higher than 0.1%, the catalytic activity for NO oxidation is in order: Ir/ZSM-5>Ir/SiO2>Ir/γ -Al2O3, which is correlated with Ir dispersion on the surface of support materials and the catalytic activity for NO reduction is in sequence: Ir/γ -Al2O3>Ir/SiO2>Ir/ZSM-5, which is attributed to the adsorbed-dissociation of NO2. Compared to Pt/γ-Al2O3, Ir/γ-Al2O3 catalyst is more benefit for the NO reduction.

  3. “Contrapuntal Reading” as a Method, an Ethos, and a Metaphor for Global IR

    DEFF Research Database (Denmark)

    Bilgin, Pinar

    2016-01-01

    How to approach Global International Relations (IR)? This is a question asked by students of IR who recognize the limits of our field while expressing their concern that those who strive for a Global IR have been less-than-clear about the “how to?” question. In this article, I point to Edward W....... Said’s approach to “contrapuntal reading” as one way of approaching Global IR that embraces diversity and reflects multiple and overlapping experiences and perspectives of humankind. More specifically, I suggest that contrapuntal reading offers students of IR a method of studying world politics...

  4. Using Fourier transform IR spectroscopy to analyze biological materials.

    Science.gov (United States)

    Baker, Matthew J; Trevisan, Júlio; Bassan, Paul; Bhargava, Rohit; Butler, Holly J; Dorling, Konrad M; Fielden, Peter R; Fogarty, Simon W; Fullwood, Nigel J; Heys, Kelly A; Hughes, Caryn; Lasch, Peter; Martin-Hirsch, Pierre L; Obinaju, Blessing; Sockalingum, Ganesh D; Sulé-Suso, Josep; Strong, Rebecca J; Walsh, Michael J; Wood, Bayden R; Gardner, Peter; Martin, Francis L

    2014-08-01

    IR spectroscopy is an excellent method for biological analyses. It enables the nonperturbative, label-free extraction of biochemical information and images toward diagnosis and the assessment of cell functionality. Although not strictly microscopy in the conventional sense, it allows the construction of images of tissue or cell architecture by the passing of spectral data through a variety of computational algorithms. Because such images are constructed from fingerprint spectra, the notion is that they can be an objective reflection of the underlying health status of the analyzed sample. One of the major difficulties in the field has been determining a consensus on spectral pre-processing and data analysis. This manuscript brings together as coauthors some of the leaders in this field to allow the standardization of methods and procedures for adapting a multistage approach to a methodology that can be applied to a variety of cell biological questions or used within a clinical setting for disease screening or diagnosis. We describe a protocol for collecting IR spectra and images from biological samples (e.g., fixed cytology and tissue sections, live cells or biofluids) that assesses the instrumental options available, appropriate sample preparation, different sampling modes as well as important advances in spectral data acquisition. After acquisition, data processing consists of a sequence of steps including quality control, spectral pre-processing, feature extraction and classification of the supervised or unsupervised type. A typical experiment can be completed and analyzed within hours. Example results are presented on the use of IR spectra combined with multivariate data processing.

  5. Critical Dispersion-Theory Tests of Silicon's IR Refractive Index

    Science.gov (United States)

    Karstens, William; Smith, D. Y.

    Silicon strongly absorbs both visible and UV light, but is highly transparent in the IR. Hence, it is a common choice for infrared windows and lenses. However, optical design is hindered by literature index values that disagree by up to 1%. In contrast optical-glass indices are known to 0.01% or better. The most widely available silicon IR indices are based on bulk measurements using either Snell's-Law refraction by a prism or channel-spectra interference of front- and backsurface reflections from a planar sample. To test the physical acceptability of these data, we have developed criteria based on a Taylor expansion of the Kramers-Kronig relation for the index at energies below strong inter-band transitions. These tests require that the coefficients of the series in powers of energy squared must be positive within the region of transparency. This is satisfied by essentially all prism measurements; their small scatter arises primarily from impurities and doping. In contrast, channel-spectra data fail in the second and third coefficients. A review of the experimental analysis indicates three problems besides purity: incorrect channel number arising from a channel-spectra model that neglects spectrum distortion by the weak lattice absorption; use of a series expansion of mixed parity in photon energy to describe the even-parity index; and use of an incorrect absorption energy in the Li-Sellmeier dispersion formula. Recommendations for IR index values for pure silicon will be discussed. Supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC02-06CH11357.

  6. Wavelet based image visibility enhancement of IR images

    Science.gov (United States)

    Jiang, Qin; Owechko, Yuri; Blanton, Brendan

    2016-05-01

    Enhancing the visibility of infrared images obtained in a degraded visibility environment is very important for many applications such as surveillance, visual navigation in bad weather, and helicopter landing in brownout conditions. In this paper, we present an IR image visibility enhancement system based on adaptively modifying the wavelet coefficients of the images. In our proposed system, input images are first filtered by a histogram-based dynamic range filter in order to remove sensor noise and convert the input images into 8-bit dynamic range for efficient processing and display. By utilizing a wavelet transformation, we modify the image intensity distribution and enhance image edges simultaneously. In the wavelet domain, low frequency wavelet coefficients contain original image intensity distribution while high frequency wavelet coefficients contain edge information for the original images. To modify the image intensity distribution, an adaptive histogram equalization technique is applied to the low frequency wavelet coefficients while to enhance image edges, an adaptive edge enhancement technique is applied to the high frequency wavelet coefficients. An inverse wavelet transformation is applied to the modified wavelet coefficients to obtain intensity images with enhanced visibility. Finally, a Gaussian filter is used to remove blocking artifacts introduced by the adaptive techniques. Since wavelet transformation uses down-sampling to obtain low frequency wavelet coefficients, histogram equalization of low-frequency coefficients is computationally more efficient than histogram equalization of the original images. We tested the proposed system with degraded IR images obtained from a helicopter landing in brownout conditions. Our experimental results show that the proposed system is effective for enhancing the visibility of degraded IR images.

  7. Looking at Art in the IR and UV

    Science.gov (United States)

    Falco, Charles

    2013-03-01

    Starting with the very earliest cave paintings art has been created to be viewed by the unaided eye and, until very recently, it wasn't even possible to see it at wavelengths outside the visible spectrum. However, it is now possible to view paintings, sculptures, manuscripts, and other cultural artifacts at wavelengths from the x-ray, through the ultraviolet (UV), to well into the infrared (IR). Further, thanks to recent advances in technology, this is becoming possible with hand-held instruments that can be used in locations that were previously inaccessible to anything but laboratory-scale image capture equipment. But, what can be learned from such ``non-visible'' images? In this talk I will briefly describe the characteristics of high resolution UV and IR imaging systems I developed for this purpose by modifying high resolution digital cameras. The sensitivity of the IR camera makes it possible to obtain images of art ``in situ'' with standard museum lighting, resolving features finer than 0.35 mm on a 1.0x0.67 m painting. I also have used both it and the UV camera in remote locations with battery-powered illumination sources. I will illustrate their capabilities with images of various examples of Western, Asian, and Islamic art in museums on three continents, describing how these images have revealed important new information about the working practices of artists as famous as Jan van Eyck. I also will describe what will be possible for this type of work with new capabilities that could be developed within the next few years. This work is based on a collaboration with David Hockney, and benefitted from image analys research supported by ARO grant W911NF-06-1-0359-P00001.

  8. Femtosecond pump probe spectroscopy for the study of energy transfer of light-harvesting complexes from extractions of spinach leaves

    CSIR Research Space (South Africa)

    Ombinda-Lemboumba, Saturnin

    2009-09-01

    Full Text Available was resuspended in cold buffer C (20 mM Hepes, pH 7.8 with NaOH) and again homogenised as above. Triton x-100 was added to the suspension to obtain the final detergent concentration of 0.7–0.9%, and the suspension was then stirred continuously on ice... of large macro-aggregates with long-range chiral order within the sample, which allows energy transfer. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) A SDS-PAGE gel of 12% acrylamide was cast (using a Bio-Rad mini-protean tetra...

  9. Ultrafast Dynamics of the VO2 Insulator-to-Metal Transition Observed by Nondegenerate Pump-Probe Spectroscopy

    Directory of Open Access Journals (Sweden)

    Haglund R. F.

    2013-03-01

    Full Text Available Non-degenerate pump (1.5 eV-probe (0.4 eV transmission spectroscopy on vanadium dioxide films grown on glass and three different sapphire substrates shows systematic variations with substrate that correlate with VO2 grain size and laser fluence. Temperature dependent measurements showed changes in the electronic response that is proportional to the metallic fraction.

  10. X-Ray Emission Spectrometer Design with Single-Shot Pump-Probe and Resonant Excitation Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Spoth, Katherine; /SUNY, Buffalo /SLAC

    2012-08-28

    Core-level spectroscopy in the soft X-ray regime is a powerful tool for the study of chemical bonding processes. The ultrafast, ultrabright X-ray pulses generated by the Linac Coherent Light Source (LCLS) allow these reactions to be studied in greater detail than ever before. In this study, we investigated a conceptual design of a spectrometer for the LCLS with imaging in the non-dispersive direction. This would allow single-shot collection of X-ray emission spectroscopy (XES) measurements with varying laser pump X-ray probe delay or a variation of incoming X-ray energy over the illuminated area of the sample. Ray-tracing simulations were used to demonstrate how the components of the spectrometer affect its performance, allowing a determination of the optimal final design. These simulations showed that the spectrometer's non-dispersive focusing is extremely sensitive to the size of the sample footprint; the spectrometer is not able to image a footprint width larger than one millimeter with the required resolution. This is compatible with a single shot scheme that maps out the laser pump X-ray probe delay in the non-dispersive direction as well as resonant XES applications at normal incidence. However, the current capabilities of the Soft X-Ray (SXR) beamline at the LCLS do not produce the required energy range in a small enough sample footprint, hindering the single shot resonant XES application at SXR for chemical dynamics studies at surfaces. If an upgraded or future beamline at LCLS is developed with lower monochromator energy dispersion the width can be made small enough at the required energy range to be imaged by this spectrometer design.

  11. Photoacoustic imaging of a near-infrared fluorescent marker based on dual wavelength pump-probe excitation

    Science.gov (United States)

    Märk, Julia; Theiss, Christoph; Schmitt, Franz-Josef; Laufer, Jan

    2014-03-01

    Photoacoustic imaging has been used to determine the spatial distribution of fluorophores, such as exogenous dyes and genetically expressed proteins, from images acquired in phantoms and in vivo. Most methods involve the acquisition of multiwavelength images and rely on differences in the absorption spectra of the tissue chromophores to estimate the spatial distribution and abundance of the latter using spectral decomposition techniques, such as model based inversion schemes. However, the inversion of 3-D images can be computationally expensive. Experimental approaches to localising contrast agents may therefore be useful, especially if quantification is not essential. This work aims to develop a method for determining the spatial distribution of a near-infrared fluorescent cell marker from images acquired using dual wavelength excitation. The excitation wavelengths coincided with the absorption and emission spectrum of the fluorophore. The contrast mechanism relies on reducing the excited state lifetime of the fluorophore by inducing stimulated emission. This changes the amount of energy thermalized by the fluorophore, and hence the photoacoustic signal amplitude. Since this is not observed in endogenous chromophores, the background may be removed by subtracting two images acquired with and without pulse delay between the pump and probe pulses. To characterise the fluorophore, the signal amplitude is measured in a cuvette as a function of pulse delay, concentration, and fluence. The spatial distribution of the fluorophore is determined from images acquired in realistic tissue phantoms. This method may be suitable for in vivo applications, such as imaging of exogenous or genetically expressed fluorescent cell markers.

  12. Tailored pump-probe transient spectroscopy with time-dependent density-functional theory: controlling absorption spectra

    Science.gov (United States)

    Walkenhorst, Jessica; De Giovannini, Umberto; Castro, Alberto; Rubio, Angel

    2016-05-01

    Recent advances in laser technology allow us to follow electronic motion at its natural time-scale with ultra-fast time resolution, leading the way towards attosecond physics experiments of extreme precision. In this work, we assess the use of tailored pumps in order to enhance (or reduce) some given features of the probe absorption (for example, absorption in the visible range of otherwise transparent samples). This type of manipulation of the system response could be helpful for its full characterization, since it would allow us to visualize transitions that are dark when using unshaped pulses. In order to investigate these possibilities, we perform first a theoretical analysis of the non-equilibrium response function in this context, aided by one simple numerical model of the hydrogen atom. Then, we proceed to investigate the feasibility of using time-dependent density-functional theory as a means to implement, theoretically, this absorption-optimization idea, for more complex atoms or molecules. We conclude that the proposed idea could in principle be brought to the laboratory: tailored pump pulses can excite systems into light-absorbing states. However, we also highlight the severe numerical and theoretical difficulties posed by the problem: large-scale non-equilibrium quantum dynamics are cumbersome, even with TDDFT, and the shortcomings of state-of-the-art TDDFT functionals may still be serious for these out-of-equilibrium situations.

  13. Derivatives as an IR regulator for massless fields

    CERN Document Server

    Elmfors, P

    1995-01-01

    The free propagator for the scalar \\lambda \\phi^4--theory is calculated exactly up to the second derivative of a background field. Using this propagator I compute the one--loop effective action, which then contains all powers of the field but with at most two derivatives acting on each field. The standard derivative expansion, which only has a finite number of derivatives in each term, breaks down for small fields when the mass is zero, while the expression obtained here has a well--defined expansion in \\phi. In this way the resummation of derivatives cures the naive IR divergence. The extension to finite temperature is also discussed.

  14. Neo-Poulantzian Perspectives in IR and the Current Crisis

    DEFF Research Database (Denmark)

    Ougaard, Morten

    This paper is about Poulantzas, historical materialism, international relations, and the current crisis. My purpose is to discuss how some Poulantzian theoretical contributions can be applied to the study of subject matters that are the focus of academic fields such as International Relations (IR...... that contains its own theoretical definition of the object under study. This object, with inspiration from Poulantzas’ notion of the imperialist chain and his general theory of society, I will define as the global social formation or for short, world society....

  15. Improved Likelihood Function in Particle-based IR Eye Tracking

    DEFF Research Database (Denmark)

    Satria, R.; Sorensen, J.; Hammoud, R.

    2005-01-01

    In this paper we propose a log likelihood-ratio function of foreground and background models used in a particle filter to track the eye region in dark-bright pupil image sequences. This model fuses information from both dark and bright pupil images and their difference image into one model. Our...... enhanced tracker overcomes the issues of prior selection of static thresholds during the detection of feature observations in the bright-dark difference images. The auto-initialization process is performed using cascaded classifier trained using adaboost and adapted to IR eye images. Experiments show good...

  16. Dynamic IR scene projector based upon the digital micromirror device

    Science.gov (United States)

    Beasley, D. Brett; Bender, Matt W.; Crosby, Jay; Messer, Tim; Saylor, Daniel A.

    2001-08-01

    Optical Sciences Corp. has developed a new dynamic infrared scene projector technology called the Micromirror Array Projector System (MAPS). The MAPS is based upon the Texas Instruments Digital Micromirror DeviceTM which has been modified to project images that are suitable for testing sensors and seekers operating in the UV, visible, and IR wavebands. The projector may be used in several configurations which are optimized for specific applications. This paper provides an overview of the design and performance of the MAPS projection system, as well as example imagery from prototype projector systems.

  17. Metal-carbon nanocomposites based on activated IR pyrolized polyacrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Efimov, Mikhail N.; Zhilyaeva, Natalya A.; Vasilyev, Andrey A.; Muratov, Dmitriy G.; Zemtsov, Lev M.; Karpacheva, Galina P. [A.V. Topchiev Institute of Petrochemical Synthesis RAS, Leninskiy Prospekt 29, 119991 Moscow Russia (Russian Federation)

    2016-05-18

    In this paper we report about new approach to preparation of metal-carbon nanocomposites based on activated carbon. Polyacrylonitrile is suggested as a precursor for Co, Pd and Ru nanoparticles carbon support which is prepared under IR pyrolysis conditions of a precursor. The first part of the paper is devoted to study activated carbon structural characteristics dependence on activation conditions. In the second part the effect of type of metal introduced in precursor on metal-carbon nanocomposite structural characteristics is shown. Prepared AC and nanocomposite samples are characterized by BET, TEM, SEM and X-ray diffraction.

  18. Metal-carbon nanocomposites based on activated IR pyrolized polyacrylonitrile

    International Nuclear Information System (INIS)

    Efimov, Mikhail N.; Zhilyaeva, Natalya A.; Vasilyev, Andrey A.; Muratov, Dmitriy G.; Zemtsov, Lev M.; Karpacheva, Galina P.

    2016-01-01

    In this paper we report about new approach to preparation of metal-carbon nanocomposites based on activated carbon. Polyacrylonitrile is suggested as a precursor for Co, Pd and Ru nanoparticles carbon support which is prepared under IR pyrolysis conditions of a precursor. The first part of the paper is devoted to study activated carbon structural characteristics dependence on activation conditions. In the second part the effect of type of metal introduced in precursor on metal-carbon nanocomposite structural characteristics is shown. Prepared AC and nanocomposite samples are characterized by BET, TEM, SEM and X-ray diffraction.

  19. IR-UWB radio-over-fiber system components development

    Science.gov (United States)

    Sultanov, Albert K.; Vinogradova, Irina L.; Meshkov, Ivan K.; Grakhova, Elizaveta P.; Shmidt, Svyatoslav P.; Abdrakhmanova, Guzel I.; Tafur Monroy, Idelfonso

    2016-03-01

    The paper describes the application of IR-UWB technology for organizing the radio part of Radio-over-Fiber system. Four physical layer components are proposed and designed in the paper: three microstrip filters and UWB antenna. Firstly the effective SCRF mask was calculated to ensure electromagnetic compatibility with existing radio services. Then this mask was considered as a cost function for filters design. The simulation was made with Agilent Genesys™ and CST Microwave Studio. All the devices have shown good performance and could be implemented on one circuit board for reducing losses.

  20. Apie filosofijos ir meno sąsajas

    OpenAIRE

    Martinkus, Vytautas

    2008-01-01

    The article provides a review of Leonarda Jekentaitė’s book “De Profundis: Psichoanalitinės Filosofijos Žvilgsniu apie Mąstytojus ir Menininkus” (2007), written by V. Martinkus, according to whom, there are still few original art philosophy studies, published by Lithuanian authors in Lithuania. The review provides an analysis of the structure of the book, the style and main subjects are distinguished. The book provides the author’s articles, written during the period of thirty years. Most of ...

  1. IR Algorithm Development for Fire and Forget Projectiles.

    Science.gov (United States)

    1982-06-18

    its in-house computer . These algorithms are then run against stored IR images of actual foreign tanks to determine the capabilities and -1il-rations of...34"ELECTE- S JUL 212U 0-1 MARCHESE 2. ALGORITHMS USED FOR ARMORED TARGET DETECTION: An algorithm is a set of logical rules or mathenatical instructions used...three adjacent pixels of the array sampled three times while the array rotates) an M2 value is computed . An M2 or variance map of the scene is thus

  2. Quench observation using quench antennas on RHIC IR quadrupole magnets

    International Nuclear Information System (INIS)

    Ogitsu, T.; Terashima, A.; Tsuchiya, K.; Ganetis, G.; Muratore, J.; Wanderer, P.

    1995-01-01

    Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals

  3. Investigation of IR absorption spectra of oral cavity bacteria

    Science.gov (United States)

    Belikov, Andrei V.; Altshuler, Gregory B.; Moroz, Boris T.; Pavlovskaya, Irina V.

    1996-12-01

    The results of comparative investigation for IR and visual absorption spectra of oral cavity bacteria are represented by this paper. There are also shown the main differences in absorption spectra of such pure bacteria cultures as : E- coli, Candida, Staph, Epidermidis, and absorption spectra of bacteria colonies cultured in tooth root canals suspected to harbour several endodontical problems. The results of experimental research targeted to investigate an effect of such combined YAG:Nd and YAG:Cr; Tm; Ho laser parameters like: wavelength, energy density, average power and etc., to oral cavity bacteria deactivation are given finally.

  4. IR Thermography of International Space Station Radiator Panels

    Science.gov (United States)

    Koshti, Ajay; Winfree, WIlliam; Morton, Richard; Howell, Patricia

    2010-01-01

    Several non-flight qualification test radiators were inspected using flash thermography. Flash thermography data analysis used raw and second derivative images to detect anomalies (Echotherm and Mosaic). Simple contrast evolutions were plotted for the detected anomalies to help in anomaly characterization. Many out-of-family indications were noted. Some out-of-family indications were classified as cold spot indications and are due to additional adhesive or adhesive layer behind the facesheet. Some out-of-family indications were classified as hot spot indications and are due to void, unbond or lack of adhesive behind the facesheet. The IR inspection helped in assessing expected manufacturing quality of the radiators.

  5. Properties of CO Molecular Gas in IR Luminous Galaxies

    OpenAIRE

    Yao, Lihong

    2003-01-01

    We present the properties of the 12CO(1-0) and (3-2) line emission from the nuclei of 60 IR luminous SLUGS galaxies. This subsample is flux limited at S60 > 5.24 Jy with FIR luminosities mostly at LFIR > 10^10 Lo. The emission line strengths of 12CO(1-0) and (3-2) transitions were compared at a common resolution of ~ 15", and the line ratios r31 vary from 0.22 to 1.72 with a mean value of 0.66 for the sources observed, indicating a large spread of the degree of excitation of CO in the sample....

  6. Data in support of FSH induction of IRS-2 in human granulosa cells: Mapping the transcription factor binding sites in human IRS-2 promoter

    Directory of Open Access Journals (Sweden)

    Surleen Kaur

    2016-03-01

    Full Text Available Insulin receptor substrate-2 (IRS-2 plays critical role in the regulation of various metabolic processes by insulin and IGF-1. The defects in its expression and/or function are linked to diseases like polycystic ovary syndrome (PCOS, insulin resistance and cancer. To predict the transcription factors (TFs responsible for the regulation of human IRS-2 gene expression, the transcription factor binding sites (TFBS and the corresponding TFs were investigated by analysis of IRS-2 promoter sequence using MatInspector Genomatix software (Cartharius et al., 2005 [1]. The ibid data is part of author׳s publication (Anjali et al., 2015 [2] that explains Follicle stimulating hormone (FSH mediated IRS-2 promoter activation in human granulosa cells and its importance in the pathophysiology of PCOS. Further analysis was carried out for binary interactions of TF regulatory genes in IRS-2 network using Cytoscape software tool and R-code. In this manuscript, we describe the methodology used for the identification of TFBSs in human IRS-2 promoter region and provide details on experimental procedures, analysis method, validation of data and also the raw files. The purpose of this article is to provide the data on all TFBSs in the promoter region of human IRS-2 gene as it has the potential for prediction of the regulation of IRS-2 gene in normal or diseased cells from patients with metabolic disorders and cancer.

  7. The insulin receptor substrate 1 (IRS1 in intestinal epithelial differentiation and in colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Diana L Esposito

    Full Text Available Colorectal cancer (CRC is associated with lifestyle factors that affect insulin/IGF signaling, of which the insulin receptor substrate 1 (IRS1 is a key transducer. We investigated expression, localization and pathologic correlations of IRS1 in cancer-uninvolved colonic epithelium, primary CRCs with paired liver metastases and in vitro polarizing Caco2 and HT29 cells. IRS1 mRNA and protein resulted higher, relative to paired mucosa, in adenomas of familial adenomatous polyposis patients and in CRCs that overexpressed c-MYC, ß-catenin, InsRß, and IGF1R. Analysis of IRS1 immunostaining in 24 cases of primary CRC with paired colonic epithelium and hepatic metastasis showed that staining intensity was significantly higher in metastases relative to both primary CRC (P<0.01 and colonic epithelium (P<0.01. Primary and metastatic CRCs, compared to colonic epithelium, contained significantly higher numbers of IRS1-positive cells (P = 0.013 and P = 0.014, respectively. Pathologic correlations in 163 primary CRCs revealed that diffuse IRS1 staining was associated with tumors combining differentiated phenotype and aggressive markers (high Ki67, p53, and ß-catenin. In Caco 2 IRS1 and InsR were maximally expressed after polarization, while IGF1R was highest in pre-polarized cells. No nuclear IRS1 was detected, while, with polarization, phosphorylated IRS1 (pIRS1 shifted from the lateral to the apical plasma membrane and was expressed in surface cells only. In HT29, that carry mutations constitutively activating survival signaling, IRS1 and IGF1R decreased with polarization, while pIRS1 localized in nuclear spots throughout the course. Overall, these data provide evidence that IRS1 is modulated according to CRC differentiation, and support a role of IRS1 in CRC progression and liver metastatization.

  8. Spin orientations of the spin-half Ir{sup 4+} ions in Sr{sub 3}NiIrO{sub 6}, Sr{sub 2}IrO{sub 4}, and Na{sub 2}IrO{sub 3}: Density functional, perturbation theory, and Madelung potential analyses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Elijah E.; Whangbo, Myung-Hwan, E-mail: mike-whangbo@ncsu.edu [Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204 (United States); Xiang, Hongjun [Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, Collaborative Innovation Center of Advanced Microstructures, and Department of Physics, Fudan University, Shanghai 200433 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093 (China); Köhler, Jürgen [Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart (Germany)

    2016-03-21

    The spins of the low-spin Ir{sup 4+} (S = 1/2, d{sup 5}) ions at the octahedral sites of the oxides Sr{sub 3}NiIrO{sub 6}, Sr{sub 2}IrO{sub 4}, and Na{sub 2}IrO{sub 3} exhibit preferred orientations with respect to their IrO{sub 6} octahedra. We evaluated the magnetic anisotropies of these S = 1/2 ions on the basis of density functional theory (DFT) calculations including spin-orbit coupling (SOC), and probed their origin by performing perturbation theory analyses with SOC as perturbation within the LS coupling scheme. The observed spin orientations of Sr{sub 3}NiIrO{sub 6} and Sr{sub 2}IrO{sub 4} are correctly predicted by DFT calculations, and are accounted for by the perturbation theory analysis. As for the spin orientation of Na{sub 2}IrO{sub 3}, both experimental studies and DFT calculations have not been unequivocal. Our analysis reveals that the Ir{sup 4+} spin orientation of Na{sub 2}IrO{sub 3} should have nonzero components along the c- and a-axis directions. The spin orientations determined by DFT calculations are sensitive to the accuracy of the crystal structures employed, which is explained by perturbation theory analyses when interactions between adjacent Ir{sup 4+} ions are taken into consideration. There are indications implying that the 5d electrons of Na{sub 2}IrO{sub 3} are less strongly localized compared with those of Sr{sub 3}NiIrO{sub 6} and Sr{sub 2}IrO{sub 4}. This implication was confirmed by showing that the Madelung potentials of the Ir{sup 4+} ions are less negative in Na{sub 2}IrO{sub 3} than in Sr{sub 3}NiIrO{sub 6} and Sr{sub 2}IrO{sub 4}. Most transition-metal S = 1/2 ions do have magnetic anisotropies because the SOC induces interactions among their crystal-field split d-states, and the associated mixing of the states modifies only the orbital parts of the states. This finding cannot be mimicked by a spin Hamiltonian because this model Hamiltonian lacks the orbital degree of freedom, thereby leading to the spin-half syndrome. The

  9. Crosstalk between adiponectin and IGF-IR in breast cancer

    Directory of Open Access Journals (Sweden)

    Loredana eMauro

    2015-07-01

    Full Text Available Obesity is a chronic and multifactorial disorder that is reaching epidemic proportions. It is characterized by an enlarged mass of adipose tissue caused by a combination of size increase of preexisting adipocytes (hypertrophy and de novo adipocyte differentiation (hyperplasia. Obesity is related to many metabolic disorders like hypertension, type 2 diabetes, metabolic syndrome, cardiovascular disease, and it is associated with an increased risk of cancer development in different tissues including breast. Adipose tissue is now regarded as not just a storage reservoir for excess energy, but rather as an endocrine organ, secreting a large number of bioactive molecules called adipokines. Among these, adiponectin represents the most abundant adipose tissue-excreted protein, which exhibits insulin-sensitizing, anti-inflammatory and antiatherogenic properties. The serum concentrations of adiponectin are inversely correlated with body mass index. Recently, low levels of plasma adiponectin have been associated with an increased risk for obesity-related cancers and development of more aggressive phenotype, concomitantly with alterations in the bioavailability of Insulin-like Growth Factor-I (IGF-I and IGF-I Receptor (IGF-IR signaling pathways. In this review we discuss the cross-talk between adiponectin/AdipoR1 and IGF-I/IGF-IR in breast cancer.

  10. Uncooled IR imager with 5-mK NEDT

    Science.gov (United States)

    Amantea, Robert; Knoedler, C. M.; Pantuso, Francis P.; Patel, Vipulkumar; Sauer, Donald J.; Tower, John R.

    1997-08-01

    The bi-material concept for room-temperature infrared imaging has the potential of reaching an NE(Delta) T approaching the theoretical limit because of its high responsivity and low noise. The approach, which is 100% compatible with silicon IC foundry processing, utilizes a novel combination of surface micromachining and conventional integrated circuits to produce a bimaterial thermally sensitive element that controls the position of a capacitive plate coupled to the input of a low noise MOS amplifier. This approach can achieve the high sensitivity, the low weight, and the low cost necessary for equipment such as helmet mounted IR viewers and IR rifle sights. The pixel design has the following benefits: (1) an order of magnitude improvement in NE(Delta) T due to extremely high sensitivity and low noise, (2) low cost due to 100% silicon IC compatibility, (3) high image quality and increased yield due to ability to do offset and sensitivity corrections on the imager, pixel-by-pixel; (4) no cryogenic cooler and no high vacuum processing; and (5) commercial applications such as law enforcement, home security, and transportation safety. Two designs are presented. One is a 50 micrometer pixel using silicon nitride as the thermal isolation element that can achieve 5 mK NE(Delta) T; the other is a 29 micrometer pixel using silicon carbide that provides much higher thermal isolation and can achieve 10 mK NE(Delta) T.

  11. Multiplexing of spatial modes in the mid-IR region

    Science.gov (United States)

    Gailele, Lucas; Maweza, Loyiso; Dudley, Angela; Ndagano, Bienvenu; Rosales-Guzman, Carmelo; Forbes, Andrew

    2017-02-01

    Traditional optical communication systems optimize multiplexing in polarization and wavelength both trans- mitted in fiber and free-space to attain high bandwidth data communication. Yet despite these technologies, we are expected to reach a bandwidth ceiling in the near future. Communications using orbital angular momentum (OAM) carrying modes offers infinite dimensional states, providing means to increase link capacity by multiplexing spatially overlapping modes in both the azimuthal and radial degrees of freedom. OAM modes are multiplexed and de-multiplexed by the use of spatial light modulators (SLM). Implementation of complex amplitude modulation is employed on laser beams phase and amplitude to generate Laguerre-Gaussian (LG) modes. Modal decomposition is employed to detect these modes due to their orthogonality as they propagate in space. We demonstrate data transfer by sending images as a proof-of concept in a lab-based scheme. We demonstrate the creation and detection of OAM modes in the mid-IR region as a precursor to a mid-IR free-space communication link.

  12. Measuring the acceleration due to gravity using an IR transceiver

    International Nuclear Information System (INIS)

    AbdElazem, Sohaib; Al-Basheer, Watheq

    2015-01-01

    In this paper, we present a new technique to study the dynamics of a free-falling object in a lab setting and to measure the acceleration due to gravity g using a simple and economic setup. The precise measurement of time taken for an object to fall freely passing an infrared (IR) transceiver is utilized to deduce the acceleration due to gravity. The reflected IR intensity from a free-falling 0.19 m rod of equally spaced white stripes of 0.01 m is detected and sent to a digital oscilloscope to observe and record the falling time period of each stripe. By fitting recorded elapsed falling times to the well-known quadratic equation of motion under constant acceleration, an accurate value of the acceleration due to gravity of g = 9.8092 ± 0.0384 m s −2 is obtained. In addition to its accuracy, the proposed technique is safer and more economic than most of the other currently used setups to determine g in undergraduate teaching labs. This study may provide undergraduate lab instructors with an efficient teaching technique for a traditional classroom experiment. (paper)

  13. Monitoring combat wound healing by IR hyperspectral imaging

    Science.gov (United States)

    Howle, Chris R.; Spear, Abigail M.; Gazi, Ehsan; Crane, Nicole J.

    2016-03-01

    In recent conflicts, battlefield injuries consist largely of extensive soft injuries from blasts and high energy projectiles, including gunshot wounds. Repair of these large, traumatic wounds requires aggressive surgical treatment, including multiple surgical debridements to remove devitalised tissue and to reduce bacterial load. Identifying those patients with wound complications, such as infection and impaired healing, could greatly assist health care teams in providing the most appropriate and personalised care for combat casualties. Candidate technologies to enable this benefit include the fusion of imaging and optical spectroscopy to enable rapid identification of key markers. Hence, a novel system based on IR negative contrast imaging (NCI) is presented that employs an optical parametric oscillator (OPO) source comprising a periodically-poled LiNbO3 (PPLN) crystal. The crystal operates in the shortwave and midwave IR spectral regions (ca. 1.5 - 1.9 μm and 2.4 - 3.8 μm, respectively). Wavelength tuning is achieved by translating the crystal within the pump beam. System size and complexity are minimised by the use of single element detectors and the intracavity OPO design. Images are composed by raster scanning the monochromatic beam over the scene of interest; the reflection and/or absorption of the incident radiation by target materials and their surrounding environment provide a method for spatial location. Initial results using the NCI system to characterise wound biopsies are presented here.

  14. Limewashed mural paintings as seen by VIS-IR reflectography

    Science.gov (United States)

    Fontana, R.; Striova, J.; Barucci, M.; Pampaloni, E.; Raffaelli, M.; Pezzati, L.; Mariotti, P.

    2015-06-01

    Near-Infrared (NIR) reflectography is a well-established technique for painting diagnostics, offering a fundamental contribution to the conservation of paintings. Since the '80s it has been routinely applied to study the execution technique of the author, as well as the presence of pentimenti, retouches, integrations or underdrawing. In the last decades IR reflectography has been extended to the visible (VIS) spectral range, providing information about the pigment composition. Up to now the multispectral analysis is still applied at an experimental level, as the processing of the image set is not straightforward. Rarely multispectral VIS-IR application has been applied to frescos, probably due to the lack, in most cases, of a scattering background. In this work we present the results provided by a multispectral scanning device based on single sensor acquisition, working in the 380-2500 nm spectral range, that is a laboratory prototype specifically built for research-grade imaging. The technique have been applied on a mock up simulating a mural painting substrate where an underdrawing, made of either carbon or iron-gall ink, was covered by different surface layers of limewash, the so-called scialbo.

  15. UV-IR mixing in nonassociative Snyder ϕ4 theory

    Science.gov (United States)

    Meljanac, Stjepan; Mignemi, Salvatore; Trampetic, Josip; You, Jiangyang

    2018-03-01

    Using a quantization of the nonassociative and noncommutative Snyder ϕ4 scalar field theory in a Hermitian realization, we present in this article analytical formulas for the momentum-conserving part of the one-loop two-point function of this theory in D -, 4-, and 3-dimensional Euclidean spaces, which are exact with respect to the noncommutative deformation parameter β . We prove that these integrals are regularized by the Snyder deformation. These results indicate that the Snyder deformation does partially regularize the UV divergences of the undeformed theory, as it was proposed decades ago. Furthermore, it is observed that different nonassociative ϕ4 products can generate different momentum-conserving integrals. Finally, most importantly, a logarithmic infrared divergence emerges in one of these interaction terms. We then analyze sample momentum nonconserving integral qualitatively and show that it could exhibit IR divergence too. Therefore, infrared divergences should exist, in general, in the Snyder ϕ4 theory. We consider infrared divergences at the limit p →0 as UV/IR mixings induced by nonassociativity, since they are associated to the matching UV divergence in the zero-momentum limit and appear in specific types of nonassociative ϕ4 products. We also discuss the extrapolation of the Snyder deformation parameter β to negative values as well as certain general properties of one-loop quantum corrections in Snyder ϕ4 theory at the zero-momentum limit.

  16. Tenoxicam-kollicoat IR binary systems: physicochemical and biological evaluation.

    Science.gov (United States)

    Ibrahim, Mohamed Abbas

    2014-01-01

    Tenoxicam (TNX) binary systems in Kollicoat IR (KL) matrix were prepared in different drug: polymer ratios using kneading and spray-drying method. The prepared binary systems were characterized for drug dissolution rate, differential scanning calorimetry (DSC), IR spectroscopy and x-ray diffractometry. The results showed that the drug dissolution rate was remarkably enhanced by incorporating it in the KL matrix either by kneading or spray-drying, and the dissolution rate was increased by decreasing the drug weight ratio. The DSc and x-ray studies revealed the presence of TNX in less crystalline or amorphous state in its-KL binary systems. Moreover, the spray-dried TNX-KL system in 1:4 ratio, that exhibited the faster dissolution rate, was formulated in oral disintegrating tablets (ODTs). The data indicated that a fast disintegration and higher drug dissolution rate was achieved in case of the ODTs containing the spray-dried form compared to the ODTS containing untreated drug or the commercial tablet (Epicotil). Also, the drug exhibited significantly (p < 0.01) faster onset of the anti-inflammatory analgesic activities in case of the ODTs containing the spray-dried form, that was superior to that observed with both the commercial tablet product and the ODTS containing untreated drug.

  17. Quantifying photometric observing conditions on Paranal using an IR camera

    Science.gov (United States)

    Kerber, Florian; Querel, Richard R.; Hanuschik, Reinhard

    2014-08-01

    A Low Humidity and Temperature Profiling (LHATPRO) microwave radiometer, manufactured by Radiometer Physics GmbH (RPG), is used to monitor sky conditions over ESO's Paranal observatory in support of VLT science operations. In addition to measuring precipitable water vapour (PWV) the instrument also contains an IR camera measuring sky brightness temperature at 10.5 μm. Due to its extended operating range down to -100 °C it is capable of detecting very cold and very thin, even sub-visual, cirrus clouds. We present a set of instrument flux calibration values as compared with a detrended fluctuation analysis (DFA) of the IR camera zenith-looking sky brightness data measured above Paranal taken over the past two years. We show that it is possible to quantify photometric observing conditions and that the method is highly sensitive to the presence of even very thin clouds but robust against variations of sky brightness caused by effects other than clouds such as variations of precipitable water vapour. Hence it can be used to determine photometric conditions for science operations. About 60 % of nights are free of clouds on Paranal. More work will be required to classify the clouds using this technique. For the future this approach might become part of VLT science operations for evaluating nightly sky conditions.

  18. Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

    Science.gov (United States)

    Pereverzev, Sergey

    2016-06-14

    A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

  19. MTG-IRS: from raw measurements to calibrated radiances

    Science.gov (United States)

    Coppens, Dorothee; Theodore, Bertrand; Klaes, Dieter

    2017-09-01

    The Meteosat Third Generation (MTG) series of future European geostationary meteorological satellites consists of two types of satellites, the imaging satellites (MTG-I) and the sounding satellites (MTG-S). The Infrared Sounder (IRS) is one of the two instruments hosted on board the MTG-S satellites. The scope of the IRS mission is to provide the user community with information on time evolution of humidity and temperature distribution, as function of latitude, longitude and altitude. Regarding time and space sampling, the entire Earth disk will be covered, with particular focus on Europe, which will be revisited every 30 minutes. This paper presents a synthetic overview of the mission and the instrument, and will go through the level 1 processing chain which takes instrument raw data to obtain spectrally and radiometrically calibrated and geolocalised radiances, called level 1b products. A discussion will be presented around the radiances uniformisation in space, spectral range and time and its impact for the users community.

  20. Parallel visual information retrieval in VizIR

    Science.gov (United States)

    Eidenberger, Horst

    2004-10-01

    This paper describes how parallel retrieval is implemented in the content-based visual information retrieval framework VizIR. Generally, two major use cases for parallelisation exist in visual retrieval systems: distributed querying and simultaneous multi-user querying. Distributed querying includes parallel query execution and querying multiple databases. Content-based querying is a two-step process: transformation of feature space to distance space using distance measures and selection of result set elements from distance space. Parallel distance measurement is implemented by sharing example media and query parameters between querying threads. In VizIR, parallelisation is heavily based on caching strategies. Querying multiple distributed databases is already supported by standard relational database management systems. The most relevant issues here are error handling and minimisation of network bandwidth consumption. Moreover, we describe strategies for distributed similarity measurement and content-based indexing. Simultaneous multi-user querying raises problems such as caching of querying results and usage of relevance feedback and user preferences for query refinement. We propose a 'real' multi-user querying environment that allows users to interact in defining queries and browse through result sets simultaneously. The proposed approach opens an entirely new field of applications for visual information retrieval systems.

  1. Crystal growth of Mg2Si for IR-detector

    Science.gov (United States)

    Tokairin, Toshio; Ikeda, Junya; Udono, Haruhiko

    2017-06-01

    Semiconducting Mg2Si is known as a thermoelectric material and recently attracts increasing attention as a Si-based, low-cost and environmental friendly material for an infrared (IR) sensor. With the aim of producing cost-effective Mg2Si single crystal substrates for the IR sensor, we have investigated single crystal growth of Mg2Si using the vertical Bridgman (VB) and micro-pulling-down (μ-PD) methods in open-system. Since the evaporation of Mg was not suppressed during the μ-PD, the composition of the Mg2Si single crystal grown by this method was not stoichiometric. On the other hand, single crystalline Mg2Si was produced by the VB method using the Si-treated inner carbon seat and BN-coated carbon crucible. The Mg2Si crystals with a diameter of 30 mm were grown at a growth rate of 0.5 mm/min and a temperature gradient of 5 °C/cm. The electron density and mobility of the crystal so obtained were 1.8×1017 cm-3 and 283 cm2V-1s-1 at 300 K, respectively. The high electron density was due to contamination from the impurities presented in the crucible.

  2. Composition dependence of phase transformation behavior and shape memory effect of Ti(Pt, Ir)

    International Nuclear Information System (INIS)

    Yamabe-Mitarai, Y.; Hara, T.; Kitashima, T.; Miura, S.; Hosoda, H.

    2013-01-01

    Highlights: ► The partial isothemal section at 1523 K was determined in Ti–Pt–Ir. ► The high-temperature shape memory effect of Ti(Pt, Ir) was investigated. ► The shape recovery ratio was 72% in Ti–10Pt–32Ir after deformation at 1123 K. ► Ir addition to TiPt is effective to improve shape memory effect of TiPt. -- Abstract: The phase transformation and high-temperature shape memory effect of Ti(Pt, Ir) were investigated. First, the Ti-rich phase boundary of Ti(Pt, Ir) was investigated by phase composition analysis by secondary electron microscopy (SEM) using an electron probe X-ray micro analyzer (EPMA), X-ray diffraction analysis and transmission electron microscopy (TEM). Then, the three alloys Ti–35Pt–10Ir, Ti–22Pt–22Ir, and Ti–10Pt–32Ir (at%) close to the phase boundary but in the single phase of Ti(Pt, Ir) were prepared by the arc melting method. The shape memory effect and crystal structure were investigated by compression loading–unloading tests and high-temperature X-ray diffraction analysis, respectively

  3. Traceable calibration of hospital 192Ir HDR sources

    International Nuclear Information System (INIS)

    Govinda Rajan, K.N.; Bhatt, B.C.; Pendse, A.M.; Kannan, V.

    2002-01-01

    Presently, no primary standard exists for the standardization of remote afterloading 192 Ir HDR sources. These sources are, therefore, being standardized by a few Secondary Standard Dosimetry Laboratories (SSDLs), in terms of Air Kerma Strength (AKS) or Reference Air Kerma Rate (RAKR) using a 0.6 cc Farmer type chamber, set up as an Interim Standard. These SSDLs offer calibration to well type of ionization chambers that are normally used by the hospitals for calibrating the 192 lr HDR source. Presently, in many countries, including India, well chambers are not commercially available. Nor do these countries offer any calibration service for 192 lr HDR source. With the result users make use of well chambers imported from different countries with their calibration traceable to the country of origin. Since no intercomparisons between these countries have been reported, the measurement consistency between hospitals becomes questionable. The problem is compounded by the fact that these chambers are used for several years without re-calibration since no calibration service is locally available. For instance, in India, the chambers have been in use in hospitals, since 1994, without a second calibration. Not all hospitals use the well chamber for the calibration of the 192 lr HDR source. Many hospitals make use of 0.6 cc chambers, in air, at short source to chamber distances, for measuring the AKS of the source. The latter method is prone to much larger inaccuracy due to the use of very short source to chamber distances without proper calibration jigs, use of 60 Co calibration factor for 192 Ir HDR source calibrations, neglecting correction factors for room scatter, fluence non-uniformity, use of arbitrary buildup factors for the buildup cap of the chamber etc. A comparison of the procedures used at hospitals revealed that various arbitrary methods are in use at hospitals. An indigenously developed well chamber was calibrated against a Reference Standard traceable to the

  4. Ligand binding affinity at the insulin receptor isoform A (IR-A and subsequent IR-A tyrosine phosphorylation kinetics are important determinants of mitogenic biological outcomes.

    Directory of Open Access Journals (Sweden)

    Harinda eRajapaksha

    2015-07-01

    Full Text Available The insulin receptor (IR is a tyrosine kinase receptor that can mediate both metabolic and mitogenic biological actions. The IR isoform-A (IR-A arises from alternative splicing of exon 11 and has different ligand binding and signalling properties compared to the IR isoform-B. The IR-A not only binds insulin but also insulin-like growth factor-II (IGF-II with high affinity. IGF-II acting through the IR-A promotes cancer cell proliferation, survival and migration by activating some unique signalling molecules compared to those activated by insulin. This observation led us to investigate whether the different IR-A signalling outcomes in response to IGF-II and insulin could be attributed to phosphorylation of a different subset of IR-A tyrosine residues or to the phosphorylation kinetics. We correlated IR-A phosphorylation to activation of molecules involved in mitogenic and metabolic signalling (MAPK and Akt and receptor internalisation rates (related to mitogenic signalling. We also extended this study to incorporate two ligands that are known to promote predominantly mitogenic ([His4, Tyr15, Thr49, Ile51] IGF-I, qIGF-I or metabolic (S597 peptide biological actions, to see if common mechanisms can be used to define mitogenic or metabolic signalling through the IR-A. The 3-fold lower mitogenic action of IGF-II compared to insulin was associated with a decreased potency in activation of Y960, Y1146, Y1150, Y1151, Y1316 and Y1322, in MAPK phosphorylation and in IR-A internalization. With the poorly mitogenic S597 peptide it was a decreased rate of tyrosine phosphorylation rather than potency that was associated with a low mitogenic potential. We conclude that both decreased affinity of IR-A binding and the kinetics of IR-A phosphorylation can independently lead to a lower mitogenic activity. None of the studied parameters could account for the lower metabolic activity of qIGF-I.

  5. Ice contamination on satellite IR sensors: the MIPAS case

    Science.gov (United States)

    Niro, F.; Fehr, T.; Kleinert, A.; Laur, H.; Lecomte, P.; Perron, G.

    2009-04-01

    MIPAS on board the ENVISAT platform is a Michelson Interferometer measuring the atmospheric limb emission in the mid-infrared (IR), from 4.15 µm to 14.5 µm [1]. The calibrated MIPAS measurements are radiance spectra as a function of wavenumber. The radiometric and spectral calibrations of the raw data are part of the Level 1 processing in the Ground Segment [2]. The accuracy of the radiometric calibration is essential in order to ensure precise temperature and trace gas retrieval in the Level 2 processing. This calibration process requires a set of cold space measurements and a series of measurements of a black body source to determine the radiometric gain function and to correct for instrument self-emission. The deep space measurements are repeated every four limb scanning sequences with the purpose of compensating the variation of instrument's temperature along the orbit. The radiometric gain function is updated every week to correct for a degraded transmission at the detector due to ice contamination. The ice contamination leads to a decrease of the signal, mainly due to ice absorption of the incoming IR radiation. This paper presents an analysis of the effect of ice contamination during the MIPAS mission; in particular we will study its impact on the radiometric accuracy and on the Level 2 retrieval precision. We will highlight the importance of the ice monitoring for the MIPAS mission and we will show that this type of monitoring allows improving the stability and the overall performances of the MIPAS instrument. The effect of ice in other ENVISAT instruments will be also mentioned (e.g., AATSR). The lessons learned during the mission about ice contamination are very important, especially for IR sensors that are the most affected by this type of problem. These lessons will be useful in order to improve the in-flight operations of present and future satellite missions. [1] H. Fischer, M. Birk, C. Blom, B. Carli, M. Carlotti, T. von Clarmann, L. Delbouille, A

  6. Analysis of Spitzer-IRS spectra of hyperluminous infrared galaxies

    Science.gov (United States)

    Ruiz, A.; Risaliti, G.; Nardini, E.; Panessa, F.; Carrera, F. J.

    2013-01-01

    Context. Hyperluminous infrared galaxies (HLIRG) are the most luminous persistent objects in the Universe. They exhibit extremely high star formation rates, and most of them seem to harbour an active galactic nucleus (AGN). They are unique laboratories for investigating the most extreme star formation and its connection to super-massive black hole growth. Aims: The relative AGN and starburst (SB) contributions to the total output in these objects is still debated. Our aim is to disentangle the AGN and SB emission of a sample of thirteen HLIRG. Methods: We studied the MIR low-resolution spectra of a sample of thirteen HLIRG obtained with the Infrared Spectrograph on board Spitzer. The 5-8 μm range is an optimal window for detecting AGN activity even in a heavily obscured environment. We performed an SB/AGN decomposition of the continuum using templates, which has been successfully applied for ULIRG in previous works. Results: The MIR spectra of all sources is largely dominated by AGN emission. By converting the 6 μm luminosity into IR luminosity, we found that ~80% of the sample shows an IR output dominated by the AGN emission. However, the SB activity is significant in all sources (mean SB contribution ~30%), showing star formation rates ~300-3000 M⊙ yr-1. With X-ray and MIR data we estimated the dust covering factor (CF) of these HLIRG, finding that a significant fraction presents a CF consistent with unity. Along with the high X-ray absorption shown by these sources, this suggests that large amounts of dust and gas enshroud the nucleus of these HLIRG, as also observed in ULIRG. Conclusions: Our results agree with previous studies of the IR SED of HLIRG using radiative transfer models, and we find strong evidence that all HLIRG harbour an AGN. Moreover, this work provides further support for the idea that AGN and SB are both crucial to understanding the properties of HLIRG. Our study of the CF supports the hypothesis that HLIRG can be divided into two

  7. Differentiation of the root of Cultivated Ginseng, Mountain Cultivated Ginseng and Mountain Wild Ginseng using FT-IR and two-dimensional correlation IR spectroscopy

    Science.gov (United States)

    Liu, Dan; Li, Yong-Guo; Xu, Hong; Sun, Su-Qin; Wang, Zheng-Tao

    2008-07-01

    Ginseng is one of the most widely used herbal medicines. Based on the grown environments and the cultivate method, three kinds of ginseng, Cultivated Ginseng (CG), Mountain Cultivated Ginseng (MCG) and Mountain Wild Ginseng (MWG) are classified. A novel and scientific-oriented method was developed and established to discriminate and identify three kinds of ginseng using Fourier transform infrared spectroscopy (FT-IR), secondary derivative IR spectra and two-dimensional correlation infrared spectroscopy (2D-IR). The findings indicated that the relative contents of starch in the CG were more than that in MCG and MWG, while the relative contents of calcium oxalate and lipids in MWG were more than that in CG and MCG, and the relative contents of fatty acid in MCG were more than that in CG and MWG. The hierarchical cluster analysis was applied to data analysis of MWG, CG and MWG, which could be classified successfully. The results demonstrated the macroscopic IR fingerprint method, including FT-IR, secondary derivative IR and 2D-IR, can be applied to discriminate different ginsengs rapidly, effectively and non-destructively.

  8. Reentrant spin glass behavior and magnetodielectric coupling of an Ir-based double perovskite compound, La2CoIrO6.

    Science.gov (United States)

    Song, Jiyue; Zhao, Bangchuan; Yin, Lihua; Qin, Yanfeng; Zhou, Jiafeng; Wang, Dong; Song, Wenhai; Sun, Yuping

    2017-09-12

    The structural, magnetic, electrical and dielectric properties of an Ir-based double perovskite compound, La 2 CoIrO 6 , have been investigated. The sample undergoes a paramagnetic-ferromagnetic transition at T C , followed by a reentrant spin-glass transition at lower temperatures. The reentrant spin glass state in La 2 CoIrO 6 is associated with the competitions of the antiferromagnetic coupling between Ir 4+ and Co 2+ ions and the ferromagnetic clusters. La 2 CoIrO 6 shows a semiconducting transport behavior in the temperature range 65 to 360 K and the transport behavior can be well described by the three-dimensional Mott variable range hopping conduction mechanism. Moreover, a strong frequency dependence of dielectric constant behavior for La 2 CoIrO 6 is observed and the dielectric relaxation can be ascribed to the electron hopping between different transition metal ions. In addition, the isothermal magnetic field dependent dielectric constant measurements show that a clear magnetodielectric coupling effect exists in La 2 CoIrO 6 at low temperatures.

  9. High Power Operation of the JLab IR FEL Driver Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

    2007-08-01

    Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

  10. Radioactivity measurements of metallic 192Ir sources by calorimetric methods

    International Nuclear Information System (INIS)

    Genka, Tsuguo; Iwamoto, Seikichi; Takeuchi, Norio

    1992-01-01

    The necessity of establishing the traceability of dose measurement in brachytherapy 192 Ir sources is realized by physicians and researchers in the medical field. Standard sources of various shapes such as open-quotes hairpin,close quotes open-quotes single pin,close quotes open-quotes thin wire,close quotes and open-quotes seedclose quotes for calibrating ionization chambers in hospitals are being demanded. Nominal activities of not only these source products but also the standard sources have been so far specified by open-quotes apparentclose quotes values. Determination of open-quotes absoluteclose quotes activity by an established means such as 4pi-beta-gamma coincidence counting is not practical because quantitative dissolution of metallic iridium is very difficult. We tried to determine the open-quotes absoluteclose quotes activity by a calorimetric method in a fully nondestructive way

  11. Hydrogenated fullerenes in space: FT-IR spectra analysis

    International Nuclear Information System (INIS)

    El-Barbary, A. A.

    2016-01-01

    Fullerenes and hydrogenated fullerenes are found in circumstellar and interstellar environments. But the determination structures for the detected bands in the interstellar and circumstellar space are not completely understood so far. For that purpose, the aim of this article is to provide all possible infrared spectra for C 20 and C 60 fullerenes and their hydrogenated fullerenes. Density Functional theory (DFT) is applied using B3LYP exchange-functional with basis set 6–31G(d, p). The Fourier transform infrared spectroscopy (FT-IR) is found to be capable of distinguishing between fullerenes, mono hydrogenated fullerenes and fully hydrogenated fullerenes. In addition, deposition of one hydrogen atom outside the fully hydrogenated fullerenes is found to be distinguished by forming H 2 molecule at peak around 4440 cm −1 . However, deposition of one hydrogen atom inside the fully hydrogenated fullerenes cannot be distinguished. The obtained spectral structures are analyzed and are compared with available experimental results.

  12. Venus Aerosol Properties from Modelling and Akatsuki IR2 Observations

    Science.gov (United States)

    McGouldrick, K.

    2017-09-01

    I am creating computer simulations of the clouds of Venus. In these simulations, I make changes to the properties of the aerosols that affect their ability to form, grow, evaporate, or combine with other particles. I then use the results of these models to predict how bright or dark Venus might appear when viewed at infrared wavelengths. By comparing this calculated brightness with the infrared observations made by the IR2 infrared camera on the Akatsuki spacecraft (currently orbiting Venus since its arrival in December 2015, built by the Japan Aerospace Exploration Agency (JAXA)), I hope to explain the causes for the changes that are seen to occur in the clouds via these and other images.

  13. Surveying the IR corona during the 2017 solar eclipse

    Science.gov (United States)

    Bryans, P.; Hannigan, J. W.; Sewell, S. D.; Judge, P. G.

    2017-12-01

    The spectral emission of the infrared solar corona is the most promising direct diagnostic of the coronal magnetic field, and yet remains poorly measured. During the 2017 total solar eclipse, we will perform the first spectral survey of the IR corona using the NCAR Airborne Interferometer. This Fourier Transform Infrared Spectrometer is configured to observe the coronal spectrum from 1.5 to 5.5 microns at R 10,000 from a ground-based site. The location is atop Casper Mountain, Wyoming (42.73ºN, 106.32ºW, 2400 masl), 8 km from the center-line of totality. In this presentation, we will outline the need for such measurements, describe the instrument design and adaptation for the eclipse measurement, observation scheme, and present preliminary results. We will also discuss implications for observing infrared coronal lines from the ground, for example with the upcoming DKIST facility.

  14. Sm cluster superlattice on graphene/Ir(111)

    Science.gov (United States)

    Mousadakos, Dimitris; Pivetta, Marina; Brune, Harald; Rusponi, Stefano

    2017-12-01

    We report on the first example of a self-assembled rare earth cluster superlattice. As a template, we use the moiré pattern formed by graphene on Ir(111); its lattice constant of 2.52 nm defines the interparticle distance. The samarium cluster superlattice forms for substrate temperatures during deposition ranging from 80 to 110 K, and it is stable upon annealing to 140 K. By varying the samarium coverage, the mean cluster size can be increased up to 50 atoms, without affecting the long-range order. The spatial order and the width of the cluster size distribution match the best examples of metal cluster superlattices grown by atomic beam epitaxy on template surfaces.

  15. Hydrogenation of Tetralin over Supported Ni and Ir Catalysts

    Directory of Open Access Journals (Sweden)

    Dipali P. Upare

    2013-01-01

    Full Text Available Selective hydrogenation and ring opening (SRO of tetrahydronaphthalene (tetralin was studied over nickel and iridium supported catalysts in the context of the removal of polynuclear aromatics from diesel fuel. The tetralin hydrogenation was carried out in a fixed-bed reactor at 270°C, using H2 pressure of 30 bars, WHSV of 2.3 h−1, and H2/feed molar ratio of 40; the resultant products were analyzed by GC and GC-MS. The Ir/SiO2 catalyst gave 85% of tetralin conversion and 75.1% of decalin products selectivity whereas Ni/SiO2 catalyst showed an unprecedented high catalytic performance with 88.3% of tetralin conversion and 93% of decalin products selectivity. The catalysts were characterized by using different characterization techniques such as XRD, TPR, and HR-TEM to know the physicochemical properties as well as active sites in the catalysts.

  16. Near-IR spectral evolution of dusty starburst galaxies

    Science.gov (United States)

    Lançon, Ariane; Rocca-Volmerange, Brigitte

    1996-11-01

    We propose a multicomponent analysis of starburst galaxies, based on a model that takes into account the young and evolved stellar components and the gas emission, with their respective extinction, in the frame of a coherent dust distribution pattern. Near-IR signatures are preferentially investigated, in order to penetrate as deep as possible into the dusty starburst cores. We computed the 1.4-2.5 μm spectra of synthetic stellar populations evolving through strong, short timescale bursts of star formation (continuum and lines, R ≃ 500). The evolution model is specifically sensitive to cool stellar populations (AGB and red supergiant stars). It takes advantage of the stellar library of Lançon & Rocca-Volmerange (1992) [A&ASS, 96, 593], observed with the same instrument (FTS/CFHT) as the analysed galaxy sample, so that the instrumental effects are minimised. The main near-IR observable constraints are the molecular signatures of CO and H2O and the slope of the continuum, observed over a range exceptionally broad for spectroscopic data. The H - K colour determined from the spectra measures the intrinsic stellar energy distribution but also differential extinction, which is further constrained by optical emission line ratios. Other observational constraints are the near-IR emission lines (Brγ, He I 2.06 μm, [Fe II] 1.64 μm, H2 2.12 μm) and the far-IR luminosity. The coherence of the results relies on the interpretation in terms of stellar populations from which all observable properties are derived, so that the link between the various wavelength ranges is secured. The luminosity LK is used for the absolute calibration. We apply this approach to the typical spectrum of the core of NGC 1614. Consistent solutions for the starburst characteristics (star-formation rate, IMF, burst age, morphology) are found and the role of each observational constraint in deriving satisfactory models is extensively discussed. The acceptable contamination of the K band light by the

  17. Solidify, An LLVM pass to compile LLVM IR into Solidity

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-12

    The software currently compiles LLVM IR into Solidity (Ethereum’s dominant programming language) using LLVM’s pass library. Specifically, his compiler allows us to convert an arbitrary DSL into Solidity. We focus specifically on converting Domain Specific Languages into Solidity due to their ease of use, and provable properties. By creating a toolchain to compile lightweight domain-specific languages into Ethereum's dominant language, Solidity, we allow non-specialists to effectively develop safe and useful smart contracts. For example lawyers from a certain firm can have a proprietary DSL that codifies basic laws safely converted to Solidity to be securely executed on the blockchain. In another example, a simple provenance tracking language can be compiled and securely executed on the blockchain.

  18. Near diffraction limited mid-IR spectromicroscopy using frequency upconversion

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter

    2014-01-01

    Mid-infrared microscopy and spectroscopy is interesting due to its medical, biological and chemical applications. Spectromicroscopy can be used for histopathology, sample analysis and diagnosis. The ability to do spectromicroscopy in the 2.5 to 4.5 μm wavelength range where many organic molecules...... technologies. With these applications in mind, we have incorporated microscopy optics into an image upconversion system, achieving near diffraction limited spatial resolution in the 3 μm range. Spectroscopic information is further acquired by appropriate control of the phase match condition of the upconversion...... have their fundamental vibrations, with the addition of sufficient spectroscopic resolution to resolve these bands, cane.g.potentially allow for diagnostics without the need for staining of the sample. On a longer timeframe, mid-IR spectromicroscopy has the potential for in-vivo diagnostics, combining...

  19. THE CHANDRA COSMOS LEGACY SURVEY: OPTICAL/IR IDENTIFICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, S.; Civano, F.; Urry, C. M. [Yale Center for Astronomy and Astrophysics, 260 Whitney Avenue, New Haven, CT 06520 (United States); Elvis, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Salvato, M. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei München (Germany); Brusa, M.; Lanzuisi, G.; Vignali, C. [Dipartimento di Fisica e Astronomia, Università di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy); Comastri, A.; Gilli, R.; Zamorani, G.; Cappelluti, N. [INAF—Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Hasinger, G. [Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States); Miyaji, T. [Instituto de Astronomía sede Ensenada, Universidad Nacional Autónoma de México, Km. 103, Carret. Tijunana-Ensenada, Ensenada, BC (Mexico); Treister, E. [Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción (Chile); Allevato, V.; Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki (Finland); Cardamone, C. [Department of Science, Wheelock College, Boston, MA 02215 (United States); Griffiths, R. E. [Physics and Astronomy Dept., Natural Sciences Division, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720 (United States); Karim, A. [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); and others

    2016-01-20

    We present the catalog of optical and infrared counterparts of the Chandra  COSMOS-Legacy  Survey, a 4.6 Ms Chandra  program on the 2.2 deg{sup 2} of the COSMOS field, combination of 56 new overlapping observations obtained in Cycle 14 with the previous C-COSMOS survey. In this Paper we report the i, K, and 3.6 μm identifications of the 2273 X-ray point sources detected in the new Cycle 14 observations. We use the likelihood ratio technique to derive the association of optical/infrared (IR) counterparts for 97% of the X-ray sources. We also update the information for the 1743 sources detected in C-COSMOS, using new K and 3.6 μm information not available when the C-COSMOS analysis was performed. The final catalog contains 4016 X-ray sources, 97% of which have an optical/IR counterpart and a photometric redshift, while ≃54% of the sources have a spectroscopic redshift. The full catalog, including spectroscopic and photometric redshifts and optical and X-ray properties described here in detail, is available online. We study several X-ray to optical (X/O) properties: with our large statistics we put better constraints on the X/O flux ratio locus, finding a shift toward faint optical magnitudes in both soft and hard X-ray band. We confirm the existence of a correlation between X/O and the the 2–10 keV luminosity for Type 2 sources. We extend to low luminosities the analysis of the correlation between the fraction of obscured AGNs and the hard band luminosity, finding a different behavior between the optically and X-ray classified obscured fraction.

  20. YSO inner disk chemistry - pushing the IRS limits

    Science.gov (United States)

    Lahuis, Fred; Blake, Geoffrey; Boogert, Adwin; Dullemond, Cornelis; Evans, Neal; Hogerheijde, Michiel; Pontoppidan, Klaus; van Dishoeck, Ewine

    2007-05-01

    The aim of this proposal is to observe molecular absorption bands at 13-15 micron of gaseous acetylene (C2H2), hydrogen cyanide (HCN), and carbon dioxide (CO2) in the planet-forming zones of a sample of nearly edge-on disk sources. These molecules are predicted to be among the most abundant organic molecules in hot gas and the precursors of much more complex, prebiotic species. In addition to being unique probes of inner disk chemistry, the molecular bands also provide a direct measure of the temperature and density of the warm gas in the planet-forming zones of disks. The presence of warm C2H2, HCN, and CO2 gas has already been reported in two proto-planetary disks. However, in existing IRS observations of other disks, the bands of these molecules are expected to lie just below the detection limit allowed by the achieved dynamic range. We have designed a new observing strategy designed to push the achievable dynamic range of the SH module by at least a factor of 3-5 to conduct the most sensitive search possible in sixteen disks. The targets have been selected on basis of deep absorption at 4.7 micron due to warm CO gas in the inner disk. The data will most certainly be the driving force for further development of optimal extraction algorithms (developed as part of the c2d legacy program) to obtain the highest S/N spectra of which the IRS is capable.

  1. A UV to mid-IR study of AGN selection

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sun Mi; Kochanek, Christopher S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Assef, Roberto [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Brown, Michael J. I. [School of Physics, Monash University, Clayton, Vic 3800 (Australia); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Jannuzi, Buell T. [Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Hickox, Ryan C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Moustakas, John [Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States)

    2014-07-20

    We classify the spectral energy distributions (SEDs) of 431,038 sources in the 9 deg{sup 2} Boötes field of the NOAO Deep Wide-Field Survey (NDWFS). There are up to 17 bands of data available per source, including ultraviolet (GALEX), optical (NDWFS), near-IR (NEWFIRM), and mid-infrared (IRAC and MIPS) data, as well as spectroscopic redshifts for ∼20,000 objects, primarily from the AGN and Galaxy Evolution Survey. We fit galaxy, active galactic nucleus (AGN), stellar, and brown dwarf templates to the observed SEDs, which yield spectral classes for the Galactic sources and photometric redshifts and galaxy/AGN luminosities for the extragalactic sources. The photometric redshift precision of the galaxy and AGN samples are σ/(1 + z) = 0.040 and σ/(1 + z) = 0.169, respectively, with the worst 5% outliers excluded. On the basis of the χ{sub ν}{sup 2} of the SED fit for each SED model, we are able to distinguish between Galactic and extragalactic sources for sources brighter than I = 23.5 mag. We compare the SED fits for a galaxy-only model and a galaxy-AGN model. Using known X-ray and spectroscopic AGN samples, we confirm that SED fitting can be successfully used as a method to identify large populations of AGNs, including spatially resolved AGNs with significant contributions from the host galaxy and objects with the emission line ratios of 'composite' spectra. We also use our results to compare with the X-ray, mid-IR, optical color, and emission line ratio selection techniques. For an F-ratio threshold of F > 10, we find 16,266 AGN candidates brighter than I = 23.5 mag and a surface density of ∼1900 AGN deg{sup –2}.

  2. IR sensor design insight from missile-plume prediction models

    Science.gov (United States)

    Rapanotti, John L.; Gilbert, Bruno; Richer, Guy; Stowe, Robert

    2002-08-01

    Modern anti-tank missiles and the requirement of rapid deployment have significantly reduced the use of passive armour in protecting land vehicles. Vehicle survivability is becoming more dependent on sensors, computers and countermeasures to detect and avoid threats. An analysis of missile propellants suggests that missile detection based on plume characteristics alone may be more difficult than anticipated. Currently, the passive detection of missiles depends on signatures with a significant ultraviolet component. This approach is effective in detecting anti-aircraft missiles that rely on powerful motors to pursue high-speed aircraft. The high temperature exhaust from these missiles contains significant levels of carbon dioxide, water and, often, metal oxides such as alumina. The plumes emits strongest in the infrared, 1 to 5micrometers , regions with a significant component of the signature extending into the ultraviolet domain. Many anti-tank missiles do not need the same level of propulsion and radiate significantly less. These low velocity missiles, relying on the destructive force of shaped-charge warhead, are more difficult to detect. There is virtually no ultraviolet component and detection based on UV sensors is impractical. The transition in missile detection from UV to IR is reasonable, based on trends in imaging technology, but from the analysis presented in this paper even IR imagers may have difficulty in detecting missile plumes. This suggests that the emphasis should be placed in the detection of the missile hard body in the longer wavelengths of 8 to 12micrometers . The analysis described in this paper is based on solution of the governing equations of plume physics and chemistry. These models will be used to develop better sensors and threat detection algorithms.

  3. 4PS/insulin receptor substrate (IRS)-2 is the alternative substrate of the insulin receptor in IRS-1-deficient mice.

    Science.gov (United States)

    Patti, M E; Sun, X J; Bruening, J C; Araki, E; Lipes, M A; White, M F; Kahn, C R

    1995-10-20

    Insulin receptor substrate-1 (IRS-1) is the major cytoplasmic substrate of the insulin and insulin-like growth factor (IGF)-1 receptors. Transgenic mice lacking IRS-1 are resistant to insulin and IGF-1, but exhibit significant residual insulin action which corresponds to the presence of an alternative high molecular weight substrate in liver and muscle. Recently, Sun et al. (Sun, X.-J., Wang, L.-M., Zhang, Y., Yenush, L. P., Myers, M. G., Jr., Glasheen, E., Lane, W.S., Pierce, J. H., and White, M. F. (1995) Nature 377, 173-177) purified and cloned 4PS, the major substrate of the IL-4 receptor-associated tyrosine kinase in myeloid cells, which has significant structural similarity to IRS-1. To determine if 4PS is the alternative substrate of the insulin receptor in IRS-1-deficient mice, we performed immunoprecipitation, immunoblotting, and phosphatidylinositol (PI) 3-kinase assays using specific antibodies to 4PS. Following insulin stimulation, 4PS is rapidly phosphorylated in liver and muscle, binds to the p85 subunit of PI 3-kinase, and activates the enzyme. Insulin stimulation also results in the association of 4PS with Grb 2 in both liver and muscle. In IRS-1-deficient mice, both the phosphorylation of 4PS and associated PI 3-kinase activity are enhanced, without an increase in protein expression. Immunodepletion of 4PS from liver and muscle homogenates removes most of the phosphotyrosine-associated PI 3-kinase activity in IRS-1-deficient mice. Thus, 4PS is the primary alternative substrate, i.e. IRS-2, which plays a major role in physiologic insulin signal transduction via both PI 3-kinase activation and Grb 2/Sos association. In IRS-1-deficient mice, 4PS/IRS-2 provides signal transduction to these two major pathways of insulin signaling.

  4. Source and Inheritance of the Within Cultivar Residual Variation Detected in an indica Variety IR64

    Directory of Open Access Journals (Sweden)

    Jian-li WU

    2007-03-01

    Full Text Available The phenotypically uniform indica variety IR64 was chosen for study of the source and inheritance of within cultivar residual variation using a set of SSR markers. Residual heterogeneity in IR64 was identified on the short arm of chromosome 2 involving at least 5 SSR loci spanning nearly 30 cM. The SSR variations originated from the parental lines of IR64 (IR5657-33-2/IR2061-465-1-5-5 and were segregating in the selfed bulk seed stock in a Mendelian manner for more than 20 years. This study verified that the within cultivar variations of SSR in a morphologically uniform variety IR64 of a selfing crop came from its parental lines, which has immediate and commercial applications including test of hybrid seed purity, varietal fingerprinting, and curation and propagation of germplasm collections.

  5. Edukacinių inovacijų taikymas X rajono švietimo ir ugdymo organizacijose

    OpenAIRE

    Juškutė, Milda

    2013-01-01

    Magistro darbe pateikiamas tyrimas, kuris yra taikomas vertinant ir analizuojant X rajono švietimo ir ugdymo organizacijų vadovų požiūrį, nuostatas, vertinimus taikant edukacines inovacijas. Išanalizuoti Europos Tarybos komunikatai, kurie reglamentuoja inovacijų, žinių trikampio ir kūrybiškumo svarbą šiuolaikinėje visuomenėje. Mokslinės ir dalykinės literatūros pagalba išryškinta kas yra inovacija ir edukacinė inovacija, jų klasifikavimas ir raiška švietime. Pateikiama gautų tyrimo duomenų an...

  6. Nanomechanical IR spectroscopy for fast analysis of liquid-dispersed engineered nanomaterials

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Yamada, Shoko; Ek, Pramod Kumar

    2016-01-01

    The proliferated use of engineered nanomaterials (ENMs), e.g. in nanomedicine, calls for novel techniques allowing for fast and sensitive analysis of minute samples. Here we present nanomechanical IR spectroscopy (NAM-IR) for chemical analysis of picograms of ENMs. ENMs are nebulized directly from...... dispersion and efficiently collected on nanomechanical string resonators through a non-diffusion limited sampling method. Even very small amounts of sample can convert absorbed IR light into a measurable frequency detuning of the string through photothermal heating. An IR absorption spectrum is thus readily...... obtained by recording this detuning of the resonator over a range of IR wavelengths. Results recorded using NAM-IR agree well with corresponding results obtained through ATR-FTIR, and remarkably, measurement including sample preparation takes only a few minutes, compared to ∼2 days sample preparation...

  7. FT-IR microscopical analysis with synchrotron radiation: The microscope optics and system performance

    International Nuclear Information System (INIS)

    Reffner, J.A.; Martoglio, P.A.; Williams, G.P.

    1995-01-01

    When a Fourier transform infrared (FT-IR) microspectrometer was first interfaced with the National Synchrotron Light Source (NSLS) in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40-100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization

  8. Relationship between HOMA-IR and serum vitamin D in Chinese children and adolescents.

    Science.gov (United States)

    Wang, Lingli; Wang, Huiyan; Wen, Huaikai; Tao, Hongqun; Zhao, Xiaowei

    2016-07-01

    The objective of this study was to examine the cross-sectional relationship between homeostasis model assessment for insulin resistance (HOMA-IR) and serum 25-hydroxyvitamin D (25-OHD) level in Chinese children and adolescents. Anthropometric indices, lipid metabolic profile, and serum levels of glucose, insulin and 25-OHD were determined among 278 healthy prepubertal and pubertal, normal and overweight/obese children and adolescents aged 8-18 years between March 2014 and February 2015. HOMA-IR was significantly different across vitamin D statuses (pHOMA-IR negatively correlated with serum 25-OHD level for all subjects (R2=0.148, pHOMA-IR and BMI and serum 25-OHD level (R2=0.654, pHOMA-IR. Our findings supported that lower vitamin D status is strongly associated with worse HOMA-IR.

  9. The Moral Values of Syi’ir Ngudi Susilo in Building of Children’s Character

    Directory of Open Access Journals (Sweden)

    Moh Hasim

    2015-12-01

    Full Text Available This research was motivated by a condition that reading of Syi’ir as a culture in societydecreased. Whereas, Syi’ir contained a lot of good values related to children’s character building. Through field research method, philology, and documentary research, this study found that Syi’ir Ngudi Susilo was Syi’ir that contains children’s moral value to build their character. Syi’ir Ngudi Susilo consists of a very useful basic moral value to  develop of children’s character. The Basic moral embedded in Syi’ir Ngudi Susilo were respect and responsibility. Respect would bring children to have polite in personality and behavior based on the moral value. From respect, children would have a responsible character that would create self-consciousness to do moral act. By those two basic moral values, respect and responsibility, then children would grow with noble characters.

  10. IR radiation characteristics and operating range research for a quad-rotor unmanned aircraft vehicle.

    Science.gov (United States)

    Gong, Mali; Guo, Rui; He, Sifeng; Wang, Wei

    2016-11-01

    The security threats caused by multi-rotor unmanned aircraft vehicles (UAVs) are serious, especially in public places. To detect and control multi-rotor UAVs, knowledge of IR characteristics is necessary. The IR characteristics of a typical commercial quad-rotor UAV are investigated in this paper through thermal imaging with an IR camera. Combining the 3D geometry and IR images of the UAV, a 3D IR characteristics model is established so that the radiant power from different views can be obtained. An estimation of operating range to detect the UAV is calculated theoretically using signal-to-noise ratio as the criterion. Field experiments are implemented with an uncooled IR camera in an environment temperature of 12°C and a uniform background. For the front view, the operating range is about 150 m, which is close to the simulation result of 170 m.

  11. Cosmological observables, IR growth of fluctuations, and scale-dependent anisotropies

    DEFF Research Database (Denmark)

    B. Giddings, Steven; Sloth, Martin Snoager

    2011-01-01

    We extend semiclassical methods in inflationary cosmology that capture leading IR corrections to correlators. Such large IR effects can be absorbed into a coordinate change when examining sufficiently local observables, but not when comparing observations at large separation in scales, such as seen...... by a late-time observer. The analysis is facilitated by definition of a scale-dependent metric and physical momentum. These assist definition of "IR-safe" observables seen by a post-inflationary observer, which are contrasted to those based on the local geometry of the reheating surface....... For such observables, the observer's horizon provides an effective IR cutoff. IR growth contributes to enhanced statistical inhomogeneities/anisotropies at short scales, observation of which by a present day observer might be sought in 21 cm measurements. Such IR corrections are argued to grow large for a very late...

  12. FT-IR microscopical analysis with synchrotron radiation: The microscope optics and system performance

    Energy Technology Data Exchange (ETDEWEB)

    Reffner, J.A.; Martoglio, P.A. [Spectra-Tech, Inc., Shelton, CT (United States); Williams, G.P. [Brookhaven National Lab., Upton, NY (United States)

    1995-01-01

    When a Fourier transform infrared (FT-IR) microspectrometer was first interfaced with the National Synchrotron Light Source (NSLS) in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40-100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization.

  13. Nanomechanical IR Spectroscopy for the fast analysis of picogram samples of engineered nanomaterials

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Ek, Pramod Kumar; Andresen, Thomas Lars

    2014-01-01

    The proliferation of engineered nanomaterials (ENMs), e.g. in nanomedicine, demands for novel sensitive techniques allowing for the analysis of minute samples. We present nanoelectromechanical system-based IR spectroscopy (NEMS-IR) of picograms of polymeric micelles. The micelles are nebulized...... with electrospray directly from dispersion and then efficiently collected on the sensor, which detects the IR-wavelength-dependent photothermal sample heating. Only 10 nL of sample (~0.1 mg/mL) is required for the acquisition of an IR spectrum. Measurement, including sample preparation, takes only a few minutes......, compared to 2 days for analysis by ATR-FT-IR. NEMS-IR constitutes a promising technique for the fast analysis of ENMs....

  14. Miofascijinių trigerinių taškų terapijos ir tempimo pratimų poveikis skausmui ir kaklo judesių amplitudei

    OpenAIRE

    Vaišnoraitė, Lina

    2013-01-01

    Tyrimo problema: miofascijinis skausmo sindromas, sukeltas aktyvių miofascijinių trigerinių, taškų vargina lėtiniais raumenų skausmais, sutrikdo judesių amplitudę, miegą ir gyvenimo kokybę. Latentiniai miofascijiniai trigeriniai taškai bet kuriuo metu, paveikti bet kokio mechaninio stimulo gali tapti aktyviais. Gydant ir taip šalinant latentinius miofascijinius trigerinius taškus užkertamas kelias aktyvių miofascijinių trigerinių taškų formavimuisi ir tuo pačiu miofascijinio skausmo sindromo ...

  15. Yo-Yo IR2 testing of elite and sub-elite soccer players

    DEFF Research Database (Denmark)

    Ingebrigtsen, Jørgen; Bendiksen, Mads; Randers, Morten Bredsgaard

    2012-01-01

    Abstract We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO(2)max, Yo-Yo IR1 and repeated sprint tests (RSA) (n = 51) and match-analyses (n = 39) were also performed. Yo-Yo IR2...

  16. High-Energy, Multi-Octave-Spanning Mid-IR Sources via Adiabatic Difference Frequency Generation

    Science.gov (United States)

    2016-10-17

    AFRL-AFOSR-VA-TR-2016-0354 High-Energy, Multi-Octave-Spanning Mid- IR Sources via Adiabatic Difference Frequency Generation Franz Kaertner...COVERED (From - To) 15 Mar 2013 to 14 Jul 2016 4. TITLE AND SUBTITLE High-Energy, Multi-Octave-Spanning Mid- IR Sources via Adiabatic Difference Frequency...ABSTRACT The creation of energetic, arbitrarily shapeable, multi-octave-spanning, coherent sources of short-wave, mid-wave, and long-wave mid- IR

  17. Exploring the Thermal Limits of IR-Based Automatic Whale Detection (ETAW)

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Exploring the thermal limits of IR -based automatic whale...mammal detection, consisting of an actively stabilized, spinning IR camera and an algorithm that detects whale blows on the basis of their thermal...2 OBJECTIVES This project aims at a cost-efficient test of the thermal limits of the abovementioned IR based automatic whale detection

  18. UV/IR Filaments for High Resolution Novel Spectroscopic Interrogation of Plumes on Nuclear Materials

    Science.gov (United States)

    2016-06-01

    6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-66 UV/ IR filaments for high resolution novel spectroscopic...by the factor to get the U.S. customary unit. UV/ IR filaments for high resolution novel spectroscopic Interrogation of Plumes on nuclear materials...10 5.1 UV filaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.2 IR filaments

  19. High-resolution x-ray scatter and reflectivity study of sputtered IR surfaces

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Abdali, S.; Hornstrup, Allan

    1993-01-01

    In recent years there has been an increased interest in the possible use of Ir as the reflecting surface in X-ray telescope programs. An X-ray study of such surfaces produced by sputtering of Ir on highly polished Zerodur flats is presented here. The study was performed using Fe K(alpha) 1 (6...... result shows that an Ir coating can be produced with nominal bulk density....

  20. Nanomechanical IR spectroscopy for fast analysis of liquid-dispersed engineered nanomaterials

    OpenAIRE

    Andersen, Alina Joukainen; Yamada, Shoko; Ek, Pramod Kumar; Andresen, Thomas Lars; Boisen, Anja; Schmid, Silvan

    2016-01-01

    The proliferated use of engineered nanomaterials (ENMs), e.g. in nanomedicine, calls for novel techniques allowing for fast and sensitive analysis of minute samples. Here we present nanomechanical IR spectroscopy (NAM-IR) for chemical analysis of picograms of ENMs. ENMs are nebulized directly from dispersion and efficiently collected on nanomechanical string resonators through a non-diffusion limited sampling method. Even very small amounts of sample can convert absorbed IR light into a measu...

  1. [Reliability of HOMA-IR for evaluation of insulin resistance during perioperative period].

    Science.gov (United States)

    Fujino, Hiroko; Itoda, Shoko; Sako, Saori; Matsuo, Kazuki; Sakamoto, Eiji; Yokoyama, Takeshi

    2013-02-01

    Hyperglycemia due to increase in insulin resistance (IR) is often observed after surgery in spite of normal insulin secretion. To evaluate the degree of IR, the golden standard method is the normoglycemic hyperinsulinemic clamp technique (glucose clamp: GC). The GC using the artificial pancreas, STG-22 (Nikkiso, Tokyo, Japan), was established as a more reliable method, since it was evaluated during steady-state period under constant insulin infusion. Homeostasis model assessment insulin resistance (HOMA-IR), however, is frequently employed in daily practice because of its convenience. We, therefore, investigated the reliability of HOMA-IR in comparison with the glucose clamp using the STG-22. Eight healthy patients undergoing maxillofacial surgery were employed in this study after obtaining written informed consent. Their insulin resistance was evaluated by HOMA-IR and the GC using the STG-22 before and after surgery. HOMA-IR increased from 0.81 +/- 0.48 to 1.17 +/- 0.50, although there were no significant differences between before and after surgery. On the other hand, M-value by GC significantly decreased after surgery from 8.82 +/- 2.49 mg x kg(-1) x min(-1) to 3.84 +/- 0.79 mg x kg(-1) x min(-1) (P = 0.0003). In addition, no significant correlation was found between the values of HOMA-IR and the M-value by GC. HOMA-IR may not be reliable to evaluate IR for perioperative period.

  2. Structural, magnetic, and electronic transport properties of pyrochlore iridate Pr2Ir2O7

    Science.gov (United States)

    Kumar, Harish; Chaurasia, Rachna; Kumari, Pratibha; Paramanik, A. K.

    2018-04-01

    We have studied the structural, magnetic, and electronic transport properties of pyrochlore iridate Pr2Ir2O7. Structural investigation has been done using x-ray powder diffraction and Rietveld analysis. Pr2Ir2O7 crystallize in cubic crystallographic phase with Fd-3m space group. Temperature dependent magnetization data does not show magnetic bifurcation down to 2 K. Electrical resistivity data of Pr2Ir2O7 exhibits metallic behavior throughout temperature range. Below 50 K, a small rise in resistivity data of Pr2Ir2O7 is observed down to 12 K.

  3. Novel near-to-mid IR imaging sensors without cooling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Boston Applied Technologies, Inc (BATi), together with Kent State University (KSU), proposes to develop a high sensitivity infrared (IR) imaging sensor without...

  4. An Evaluation of Trends in Patient and Public Awareness of IR.

    Science.gov (United States)

    Heister, David; Jackson, Susan; Doherty-Simor, Margaret; Newton, Isabel

    2018-03-20

    To evaluate patient and public awareness of interventional radiology (IR). This single-center study prospectively administered voluntary paper surveys to 80 patients in an academic hospital radiology waiting room. Separate, Internet-based surveys were administered to the general public. Additionally, Internet metadata were used to evaluate relative search engine activity and IR-related news coverage compared with similar procedural specialties. 65% of radiology department outpatients had no prior knowledge of IR. Of the general population surveyed, 72% could not identify an interventional radiologist as a physician. Relative annual IR-related Google search volumes peaked in 2004 and were at their nadir in 2011. After normalizing for number of practicing physicians, IR was the subject of substantially fewer Google searches than similar specialties (15.9% of urology volumes, 27.9% of cardiology volumes, and 39.0% of vascular surgery volumes). Between 2006 and 2016, IR had a similar rate of annual increase in the volume of Internet news results as similar medical specialties, although the volumes reached by IR in 2016 were obtained by more established fields, such as cardiology, in 2011. These data provide metrics of current and historical awareness trends in IR, which demonstrate low patient and public awareness. The findings of this study may help guide future efforts to promote patient and public awareness of IR. Published by Elsevier Inc.

  5. Who We Are and What We Can Become: An Analysis of Professional Identity Formation in IR.

    Science.gov (United States)

    Keller, Eric J; McGee, Katherine A; Resnick, Scott A; Trerotola, Scott O; Valji, Karim; Johnson, Matthew S; Collins, Jeremy D; Vogelzang, Robert L

    2017-06-01

    To characterize the unique experiences, values, and perspectives of interventional radiology (IR) fellows. Sixteen fellows from 4 US vascular and IR programs were interviewed within 2 months of beginning and 2-3 months following their 2015-2016 fellowships about patient interactions, training experiences, and views of IR and other specialties. Interviews were systematically analyzed for dominant themes by using constructivist grounded theory. Four interviews with 2015-2016 interventional cardiology fellows, 16 interviews with IR attending physicians, and online descriptions of IR were also analyzed for context. Themes were compared qualitatively and quantitatively. Interobserver agreement was good for interview themes (κ = 0.70; P IR fellows' professional identity emerged primarily from radiologic and surgical interests, with distinct emphasis on being "innovators," "thinking differently," and "needing to adapt and advertise abilities to survive." Fellows' descriptions of patient care were more clinically focused than past interviews with attending physicians (P = .05), but clinical interests common in medical specialties were limited, and descriptions of "nonprocedural patient care" were primarily periprocedural (81%). Descriptions of the future of the field conveyed competing pressures, loose role definition, and disconnect between academic and private-practice IR. IR fellows share professional interests, views of their field and others, and descriptions of patient care, but there is uncertainty regarding future roles of the specialty and a need for more specific and unified definitions of nonprocedural patient care in IR. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  6. TIME-RESOLVED INFRARED SPECTROSCOPY IN THE U121R BEAMLINE AT THE NSLS

    Energy Technology Data Exchange (ETDEWEB)

    CARR,G.L.; LAVEIGNE,J.D.; LOBO,R.P.S.M.; REITZE,D.H.; TANNER,D.B.

    1999-07-19

    A facility for performing time-resolved infrared spectroscopy has been developed at the NSLS, primarily at beamline U12IR. The pulsed IR light from the synchrotron is used to perform pump-probe spectroscopy. The authors present here a description of the facility and results for the relaxation of photoexcitations in both a semiconductor and superconductor.

  7. TIME-RESOLVED INFRARED SPECTROSCOPY IN THE U121R BEAMLINE AT THE NSLS

    International Nuclear Information System (INIS)

    CARR, G.L.; LAVEIGNE, J.D.; LOBO, R.P.S.M.; REITZE, D.H.; TANNER, D.B.

    1999-01-01

    A facility for performing time-resolved infrared spectroscopy has been developed at the NSLS, primarily at beamline U12IR. The pulsed IR light from the synchrotron is used to perform pump-probe spectroscopy. The authors present here a description of the facility and results for the relaxation of photoexcitations in both a semiconductor and superconductor

  8. Energy Efficient Clothes Dryer with IR Heating and Electrostatic Precipitator

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Stanton [GE Global Research, Niskayuna, NY (United States)

    2017-12-12

    The project goal was to develop a revolutionary energy saving technology for residential clothes drying. The team developed an IR (infrared) heating system and NESP (Nebulizer and Electro-Static Precipitator) for integration into a ventless clothes dryer. The proposed technology addresses two of the major inefficiencies in current electric vented dryers by providing effective energy transfer for the removal of the water and recapture of the vapor latent heat. The IR heaters operating in the mid wave (2.5-10um) are very efficient as they target the 3-micron peak absorption of the water molecule. This allows direct energy absorption, unlike conventional element heaters where heat is transferred by convection. The low power NESP removes water vapor from the exhausted stream and recaptures the latent heat in the ESP (Electro-Static Precipitator) exchanger section. This allows the warm dry air to be recirculated back into the drum for additional efficiency savings. The remaining majority of the dryer hardware stays the same. Summing the efficiency gain from the two subcomponents we anticipated the EF (Efficiency Factor) to exceed the goal of 4.04. EF is obtained by dividing the weight (lbs) of water removed by the energy (kWhr) used, where the test load size is 8.45 lbs of bone dry clothing wetted to 57.5% or 4.8lbs of water, and dried to a remaining moisture content of 2.5-5%. Additional benefits include not having to recondition (heat or cool) the large amounts of make-up air to replace the air exhausted by a vented dryer. It was anticipated that the NESP/heat exchanger would be the most challenging and highest risk element in the program. Therefore, the team focused their efforts during Phase 1 of the program on the design, construction, testing, and optimization of the NESP/heat exchanger. At the end Phase 1, the team compared the performance of the NESP/heat exchanger with the system level requirements and made a Go/No-Go decision on proceeding with the second

  9. Cell surface GRP78 facilitates hepatoma cells proliferation and migration by activating IGF-IR.

    Science.gov (United States)

    Yin, Yancun; Chen, Chen; Chen, Jinliang; Zhan, Renhui; Zhang, Qiang; Xu, Xiaoyan; Li, Defang; Li, Minjing

    2017-07-01

    The 78kDa glucose regulated protein (GRP78) is a multifunctional chaperone that is involved in a variety of cellular processes. Insulin like growth factor I receptor (IGF-IR) often aberrant expresses in many types of tumor cells. The IGF-IR signaling plays key roles in carcinogenesis and maintenance of the malignant phenotype. The crosstalk between GRP78 and IGF-IR molecules has not well been illuminated. Here, we demonstrated a reciprocal regulation of GRP78 expression and IGF-IR pathway activation. IGF-I induced GRP78 expression in hepatoma cells. IGF-IR knockdown or IGF-IR inhibitor repressed GRP78 expression. Both phosphatidylinositol 3-kianase (PI3K) and mitogen-activated protein kinase (MAPK) pathways involved in IGF-I induction of GRP78 expression. Interestingly, treatment of hepatoma cells with IGF-I re-distributes GRP78 from endoplasmic reticulum (ER) to cell surface and promotes its physical interaction with IGF-IR. Also, GRP78 promotes IGF-IR phosphorylation and activation. Blocked of GRP78 by small interfering RNA or inhibition of GRP78 function by (-)-epigallocatechin gallate (EGCG) blocks IGF-I induced IGF-IR phosphorylation and its downstream signaling. Further, blocked cell surface GRP78 with antibody inhibits IGF-I stimulated cellular proliferation and migration. These data reveal an essential role for the molecular chaperone GRP78 in IGF-IR signaling and implicate the use of GRP78 inhibitors in blocking IGF-IR signaling in hepatoma cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Water equivalent phantom materials for 192Ir brachytherapy

    Science.gov (United States)

    Schoenfeld, Andreas A.; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2015-12-01

    Several solid phantom materials have been tested regarding their suitability as water substitutes for dosimetric measurements in brachytherapy with 192Ir as a typical high energy photon emitter. The radial variations of the spectral photon fluence, of the total, primary and scattered photon fluence and of the absorbed dose to water in the transversal plane of the tested cylindrical phantoms surrounding a centric and coaxially arranged Varian GammaMed afterloading 192Ir brachytherapy source were Monte-Carlo simulated in EGSnrc. The degree of water equivalence of a phantom material was evaluated by comparing the radial dose-to-water profile in the phantom material with that in water. The phantom size was varied over a large range since it influences the dose contribution by scattered photons with energies diminished by single and multiple Compton scattering. Phantom axis distances up to 10 cm were considered as clinically relevant. Scattered photons with energies reaching down into the 25 keV region dominate the photon fluence at source distances exceeding 3.5 cm. The tested phantom materials showed significant differences in the degree of water equivalence. In phantoms with radii up to 10 cm, RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR phantoms show excellent water equivalence with dose deviations from a water phantom not exceeding 0.8%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene show deviations up to 2.6%. For larger phantom radii up to 30 cm, the deviations for RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, and Plastic Water LR remain below 1.4%, while Original Plastic Water (as of 2015), Plastic Water (1995), Blue Water, polyethylene, and polystyrene produce deviations up to 8.1%. PMMA plays a separate role, with deviations up to 4.3% for radii not exceeding 10 cm, but below 1% for radii up to 30 cm. As suggested by

  11. Competing reaction channels in IR-laser-induced unimolecular reactions

    International Nuclear Information System (INIS)

    Berman, M.R.

    1981-01-01

    The competing reaction channels in the unimolecular decomposition of two molecules, formaldehyde and tetralin were studied. A TEA CO 2 laser was used as the excitation source in all experiments. The dissociation of D 2 CO was studied by infrared multiphoton dissociation (MPD) and the small-molecule nature of formaldehyde with regard to MPD was explored. The effect of collisions in MPD were probed by the pressure dependence of the MPD yield and ir fluorescence from multiphoton excited D 2 CO. MPD yield shows a near cubic dependence in pure D 2 CO which is reduced to a 1.7 power dependence when 15 torr of NO is added. The peak amplitude of 5 μm ir fluorescence from D 2 CO is proportional to the square of the D 2 CO pressure in pure D 2 CO or in the presence of 50 torr of Ar. Results are explained in terms of bottlenecks to excitation at the v = 1 level which are overcome by a combination of vibrational energy transfer and rotational relaxation. The radical/molecule branching ratio in D 2 CO MPD was 0.10 +- 0.02 at a fluence of 125 J/cm 2 at 946.0 cm -1 . The barrier height to molecular dissociation was calculated to be 3.6 +- 2.0 kcal/mole below the radical threshold or 85.0 +- 3.0 kcal/mole above the ground state of D 2 CO. In H 2 CO, this corresponds to 2.5 +- 2.0 kcal/mole below the radical threshold or 83.8 +- 3.0 kcal/mole above the ground state. Comparison with uv data indicate that RRKM theory is an acceptable description of formaldehyde dissociation in the 5 to 10 torr pressure range. The unimolecular decomposition of tetralin was studied by MPD and SiF 4 - sensitized pyrolysis. Both techniques induce decomposition without the interference of catalytic surfaces. Ethylene loss is identified as the lowest energy reaction channel. Dehydrogenation is found to result from step-wise H atom loss. Isomerization via disproportionation is also identified as a primary reaction channel

  12. High throughput testing and characterization of IR readouts and hybrids

    Science.gov (United States)

    Mandl, William J.; Bui, Khang X.; Patel, Manilal J.

    1992-07-01

    A program to upgrade the test capability for IR focal plane arrays and readouts is in progress at Aerojet. The objective of the development is to reduce the number and complexity of the steps in the test process, reduce in socket test time and provide a simplified set up procedure for production testing. There are two areas of study in the program. One is concerned with examining multiple fabrication sources for readout circuits. The application of a commercially available automated test system for production testing and engineering characterization of readouts and focal plane arrays is discussed. The Sentry Series 80 mixed signal tester is being fixtured for low noise measurements and interfacing to dewars for cryogenic testing. The multiuser foreground/background operating system software has the advantage of allowing noise and other statistical calculations to be performed in the background without impeding test measurements. It also has the advantage in production of requiring no manual instrumentation set up or interconnect. The improvements in test throughput and analysis capability will be shown in adapting this class of tester as opposed to assembling test instruments in a custom made computer controlled test approach.

  13. FT-IR spectroscopic studies of polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Salisbury, D.W.; Allen, J.E. Jr.; Donn, B.; Moore, W.J.; Khanna, R.K.

    1990-01-01

    Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared absorption coefficients instead of those at the temperature of interest because of the latter's unavailability. The present studies are designed to address the differences between the calculated and experimental thermal emission spectra and to provide information which will be useful in future ultraviolet induced infrared fluorescence studies. The emission spectra have been obtained for temperatures up to 825K using an emission cell designed to mount against an external port of an FT-IR spectrometer. These spectra provide information concerning relative band intensities and peak positions which is unavailable from previous calculations

  14. 640 X 480 MOS PtSi IR sensor

    Science.gov (United States)

    Sauer, Donald J.; Shallcross, Frank V.; Hseuh, Fu-Lung; Meray, Grazyna M.; Levine, Peter A.; Gilmartin, Harvey R.; Villani, Thomas S.; Esposito, Benjamin J.; Tower, John R.

    1991-12-01

    The design of a 1st and 2nd generation 640(H) X 480(V) element PtSi Schottky-barrier infrared image sensor employing a low-noise MOS X-Y addressable readout multiplexer and on-chip low-noise output amplifier is described. Measured performance characteristics for Gen 1 devices are presented along with calculated performance for the Gen 2 design. A multiplexed horizontal/vertical input address port and on-chip decoding is used to load scan data into CMOS horizontal and vertical scanning registers. This allows random access to any sub-frame in the 640 X 480 element focal plane array. By changing the digital pattern applied to the vertical scan register, the FPA can be operated in either an interlaced or non- interlaced format, and the integration time may be varied over a wide range (60 microsecond(s) to > 30 ms, for RS170 operation) resulting in a form of 'electronic shutter,' or variable exposure control. The pixel size of 24-micrometers X 24-micrometers results in a fill factor of 38% for 1.5-micrometers process design rules. The overall die size for the IR imager is 13.7 mm X 17.2 mm. All digital inputs to the chip are TTL compatible and include ESD protection.

  15. Tunable IR differential absorption lidar for remote sensing of chemicals

    Science.gov (United States)

    Prasad, Coorg R.; Kabro, Pierre; Mathur, Savyasachee L.

    1999-10-01

    Standoff sensors for rapid remote detection of chemical emissions from either clandestine chemical production sites, chemical and biological warfare agents, concealed internal combustion engine emissions or rocket propellants from missiles are required for several DoD applications. The differential absorption lidar (DIAL) operating in the infrared wavelengths has established itself as a very effective tool for rapidly detecting many of the chemicals, with sufficient sensitivity with a range of several kilometers. The wavelengths required for this task lie within the atmospheric window regions 3 to 5 micrometers and 8 to 12 micrometers . We are currently developing a differential absorption lidar (DIAL) tunable in the 3 to 5 micrometers range for detecting low concentrations of chemical species with high sensitivity (5 ppb) and accuracy (error measurements for greater than 5 km range. We have successfully established the feasibility of an innovative frequency agile laser source which is the crucial component of the infrared DIAL. A diode-pumped ytterbium YAG laser was built for pumping and rapidly tuning an optical parametric oscillator (OPO) over the mid-infra red region. Good performance (5 mJ/pulse) of the laser and low threshold wide infra red tuning of OPO (2.2 - 3.1 micrometers ) were demonstrated. The simulated performance of the topographical IR-DIAL showed that 5 ppb concentration can be measured at 5 km range with a 35 cm telescope.

  16. Mid-IR enhanced laser ablation molecular isotopic spectrometry

    Science.gov (United States)

    Brown, Staci; Ford, Alan; Akpovo, Codjo A.; Johnson, Lewis

    2016-08-01

    A double-pulsed laser-induced breakdown spectroscopy (DP-LIBS) technique utilizing wavelengths in the mid-infrared (MIR) for the second pulse, referred to as double-pulse LAMIS (DP-LAMIS), was examined for its effect on detection limits compared to single-pulse laser ablation molecular isotopic spectrometry (LAMIS). A MIR carbon dioxide (CO2) laser pulse at 10.6 μm was employed to enhance spectral emissions from nanosecond-laser-induced plasma via mid-IR reheating and in turn, improve the determination of the relative abundance of isotopes in a sample. This technique was demonstrated on a collection of 10BO and 11BO molecular spectra created from enriched boric acid (H3BO3) isotopologues in varying concentrations. Effects on the overall ability of both LAMIS and DP-LAMIS to detect the relative abundance of boron isotopes in a starting sample were considered. Least-squares fitting to theoretical models was used to deduce plasma parameters and understand reproducibility of results. Furthermore, some optimization for conditions of the enhanced emission was achieved, along with a comparison of the overall emission intensity, plasma density, and plasma temperature generated by the two techniques.

  17. Mid-IR Spectra of Refractory Minerals Relevant to Comets

    Science.gov (United States)

    Jauhari, Shekeab

    2008-09-01

    On 4 July 2005 the Spitzer Space Telescope obtained mid-IR ( 5-40 µm) spectra of the ejecta from the hypervelocity impact of the Deep Impact projectile with comet 9P/Tempel 1. Spectral modeling demonstrates that there are abundant minerals present in the ejecta including Ca/Fe/Mg-rich silicates, carbonates, phyllosilicates, water ice, amorphous carbon, and sulfides [1]. However, precise mineralogical identifications are hampered by the lack of comprehensive 5 - 40 µm spectral measurements of the emissivity for a broad compositional range of these materials. Here, we present our initial results for 2 - 50 µm transmission spectra and absorption constants for materials relevant to comets, including pyrrhotite, pyrite, and several phyllosilicate (clay) minerals. Measuring the transmission of materials over the full spectral range sensitive by Spitzer requires grinding the minerals into submicron powders and then mixing them with KBr (for the 1-25 um region) and polyethylene (16-50 um region) to form pellets. Transmission measurements of sub-micron sulfides are particularly difficult to obtain because the minerals oxidize rapidly upon grinding and subsequent handling unless special care is taken. A detailed description of our sample preparation and measurement technique will be provided to assist other researchers in their attempts to acquire similar spectra. References: [1] Lisse, C.M. et al., Science 313, 635 - 640 (2006)

  18. Quadrupole magnets for IR-FEL at RRCAT

    International Nuclear Information System (INIS)

    Ruwali, Kailash; Singh, Kushraj; Mishra, Anil Kumar; Biswas, Bhaskar

    2013-01-01

    The IR-FEL project at RRCAT needs quadrupole magnets for focusing 15 to 35 MeV electron beam through a dog-leg type beam line. This bend needs tighter relative tolerances on the central quadrupole triplet . The magnetic design, fabrication and magnetic characterization of five quadrupole magnets were carried out. The poles are detachable and wider than the coils. This significantly improves the good field region of the magnet. The magnet cross-section was optimized using 2D POISON code and entry-exit tapers were optimized using 3D code TOSCA.. The aperture radius of the magnet is 30 mm and the total core length is 180 mm. The integrated gradient of magnet is 0.51 T. The magnetic measurements were carried out using Danfysik make rotating coil bench model 690. Integrated gradient and multipoles present in the magnet aperture were measured at various excitation levels. The details of magnetic development and the magnetic measurements are discussed in this paper. (author)

  19. Hydrocarbon decomposition kinetics on the Ir(111) surface.

    Science.gov (United States)

    Tetlow, H; Curcio, D; Baraldi, A; Kantorovich, L

    2018-02-28

    The kinetics of the thermal decomposition of hydrocarbons on the Ir(111) surface is determined using kinetic Monte Carlo (kMC) and rate equations simulations, both based on the density functional theory (DFT) calculated energy barriers of the involved reaction processes. This decomposition process is important for understanding the early stages of epitaxial graphene growth where the deposited hydrocarbon acts as a carbon feedstock for graphene formation. The methodology of the kMC simulations and the rate equation approaches is discussed and a comparison between the results obtained from both approaches is made in the case of the temperature programmed decomposition of ethylene for different initial coverages. The theoretical results are verified against experimental data from in situ X-ray photoelectron spectroscopy (XPS) experiments. Both theoretical approaches give reasonable results; however we find that, as expected, rate equations are less reliable at high coverages. We find that the agreement between experiment and theory can be improved in all cases if slight adjustments are made to the energy barriers in order to account for the intrinsic errors in DFT. Finally we extend our approach to the case where hydrocarbon species are dosed onto the substrate continuously, as in the chemical vapour deposition (CVD) graphene growth method. For ethylene and methane the thermal decomposition mechanism is determined, and it is found that in both cases the formation of C monomers is to be expected, which is limited by the presence of hydrogen atoms.

  20. Composite delamination depth profiling in sonic-IR imaging

    Science.gov (United States)

    Zhao, Selina X.; Han, Xiaoyan; Favro, Lawrence D.; Newaz, Golam; Thomas, Robert L.

    2012-05-01

    Impact damage remains a major issue for aerospace composite structures. Considerable internal damage can occur in laminated composites from external impact loads in service with only minimal visual detectability from the surface of the structure. Damage can occur at any ply depth without visual indications on the front surface. Accurate depth measurements can aid repair assessments. This method is focused on investigating depth profiling of composite delamination by using Sonic-IR, which is a nondestructive evaluation method (NDE) technique that makes images of defects using an infrared camera with an ultrasonic transducer as a stimulation source. The depth profiling relies on the time delays of the temperature increases at the surface from the different defect depths. To process the time vs. temperature data captured from the camera, polynomial curve fitting was used. A mathematical model has been built to calculated time vs. second derivative of temperature curves for depth measurements. The samples used to calibrate the mathematical model data are carbon fiber composite panels with ply thickness variance and inserts with known depths.

  1. Structure, IR and Raman spectra of phosphotrihydrazide studied by DFT.

    Science.gov (United States)

    Furer, V L; Vandyukov, A E; Majoral, J P; Caminade, A M; Kovalenko, V I

    2016-09-05

    The FTIR and FT Raman measurements of the phosphotrihydrazide (S)P[N(Me)-NH2]3 have been performed. This compound is a zero generation dendrimer G0 with terminal amine groups. Structural optimization and normal mode analysis were obtained for G0 by the density functional theory (DFT). Optimized geometric bond length and angles obtained by DFT show good agreement with experiment. The amine terminal groups are characterized by the well-defined bands at 3321, 3238, 1614cm(-1) in the experimental IR spectrum and by bands at 3327, 3241cm(-1) in the Raman spectrum of G0. The experimental frequencies of asymmetric and symmetric NH2 stretching vibrations of amine group are lower than theoretical values due to intramolecular NH⋯S hydrogen bond. This hydrogen bond is also responsible for higher experimental infrared intensity of these bands as compared with theoretical values. Relying on DFT calculations a complete vibrational assignment is proposed for the studied dendrimer. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Simple laboratory methods for quantitative IR measurements of CW agents

    Science.gov (United States)

    Puckrin, Eldon; Thériault, Jean-Marc; Lavoie, Hugo; Dubé, Denis; Lepage, Carmela J.; Petryk, Michael

    2005-11-01

    A simple method is presented for quantitatively measuring the absorbance of chemical warfare (CW) agents and their simulants in the vapour phase. The technique is based on a standard lab-bench FTIR spectrometer, 10-cm gas cell, a high accuracy Baratron pressure manometer, vacuum pump and simple stainless-steel hardware components. The results of this measurement technique are demonstrated for sarin (GB) and soman (GD). A second technique is also introduced for the passive IR detection of CW agents in an open- air path located in a fumehood. Using a modified open-cell with a pathlength of 45 cm, open-air passive infrared measurements have been obtained for simulants and several classical CW agents. Detection, identification and quantification results based on passive infrared measurements are presented for GB and the CW agent simulant, DMMP, using the CATSI sensor which has been developed by DRDC Valcartier. The open-cell technique represents a relatively simple and feasible method for examining the detection capability of passive sensors, such as CATSI, for CW agents.

  3. IRS2 and PTEN are key molecules in controlling insulin sensitivity in podocytes.

    Science.gov (United States)

    Santamaria, Beatriz; Marquez, Eva; Lay, Abigail; Carew, RoseaMarie M; González-Rodríguez, Águeda; Welsh, Gavin I; Ni, Lan; Hale, Lorna J; Ortiz, Alberto; Saleem, Moin A; Brazil, Derek P; Coward, Richard J; Valverde, Ángela M

    2015-12-01

    Insulin signaling to the glomerular podocyte is important for normal kidney function and is implicated in the pathogenesis of diabetic nephropathy (DN). This study determined the role of the insulin receptor substrate 2 (IRS2) in this system. Conditionally immortalized murine podocytes were generated from wild-type (WT) and insulin receptor substrate 2-deficient mice (Irs2(-/-)). Insulin signaling, glucose transport, cellular motility and cytoskeleton rearrangement were then analyzed. Within the glomerulus IRS2 is enriched in the podocyte and is preferentially phosphorylated by insulin in comparison to IRS1. Irs2(-/-) podocytes are significantly insulin resistant in respect to AKT signaling, insulin-stimulated GLUT4-mediated glucose uptake, filamentous actin (F-actin) cytoskeleton remodeling and cell motility. Mechanistically, we discovered that Irs2 deficiency causes insulin resistance through up-regulation of the phosphatase and tensin homolog (PTEN). Importantly, suppressing PTEN in Irs2(-/-) podocytes rescued insulin sensitivity. In conclusion, this study has identified for the first time IRS2 as a critical molecule for sensitizing the podocyte to insulin actions through its ability to modulate PTEN expression. This finding reveals two potential molecular targets in the podocyte for modulating insulin sensitivity and treating DN. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Structure and dynamics of the class i young stellar object L1489 IRS

    DEFF Research Database (Denmark)

    Brinch, C.; Crapsi, A.; Hogerheijde, M. R.

    2007-01-01

    properly, implying that L1489 IRS is located partially behind this core. Conclusions. We speculate that L1489 IRS was originally formed closer to the center of this core, but has migrated to its current position over the past few times 105 yr, consistent with their radial velocity difference of 0.4 kms-1...

  5. 20 CFR 418.1150 - When will we use your amended tax return filed with IRS?

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false When will we use your amended tax return... your amended U.S. Individual Income Tax Return on the required IRS form and a copy of the IRS letter... income-related monthly adjustment amount. Determinations Using a More Recent Tax Year's Modified Adjusted...

  6. Examining China’s Assertiveness through the Eyes of Chinese IR Scholars

    DEFF Research Database (Denmark)

    Feng, Huiyun; He, Kai

    reactions. Relying on an original survey of China’s IR scholars conducted in Beijing in 2013 and using structural equation modeling (SEM), we empirically examine Chinese IR scholars’ attitude towards Chinese power versus the United States, their perceptions of U.S. policy in Asia, and their preference...

  7. Bleaching of the post-IR IRSL signal: new insights for feldspar luminescence dating

    NARCIS (Netherlands)

    Kars, R.H.; Reimann, T.; Ankjaergaard, C.; Wallinga, J.

    2014-01-01

    Post-infrared (pIR) stimulated luminescence dating of sedimentary feldspar largely avoids the effects of anomalous fading that affect conventional infrared stimulated luminescence (IRSL) dating. However, optical resetting of pIR signals is more difficult than resetting the conventional IRSL signal,

  8. 78 FR 76894 - Proposed Collection; Comment Request for the IRS Taxpayer Burden Surveys

    Science.gov (United States)

    2013-12-19

    ... R. Joseph Durbala, (202) 622-3634, at Internal Revenue Service, room 6129, 1111 Constitution Avenue... activities, tax-related recordkeeping, gathering materials, learning about tax law, using IRS and/or non-IRS... preparation software, increased efficiency of such software, changes in tax preparation regulations, the...

  9. Are feldspar SAR protocols appropriate for post-IR IRSL dating?

    NARCIS (Netherlands)

    Kars, R.H.; Reimann, T.; Wallinga, J.

    2014-01-01

    Recently proposed post-infrared infrared stimulated luminescence (post-IR IRSL or pIR) dating protocols have largely overcome problems associated with anomalous fading and have become increasingly important for age determination of Quaternary sediments. Here, we investigate the suitability of the

  10. Genetic variation near IRS1 associates with reduced adiposity and an impaired metabolic profile

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas; Zillikens, M Carola; Stančákova, Alena

    2011-01-01

    genes with potential links to adipocyte physiology. Notably, the body-fat-decreasing allele near IRS1 is associated with decreased IRS1 expression and with an impaired metabolic profile, including an increased visceral to subcutaneous fat ratio, insulin resistance, dyslipidemia, risk of diabetes...

  11. A Rapid Method of Crude Oil Analysis Using FT-IR Spectroscopy

    African Journals Online (AJOL)

    HP USER

    spectroscopy as a substitute to traditional petroleum geochemical methods for crude oil characterisation. IR spectra of Crude oil sample containing a mixture of both degraded (sample 151) and non-degraded (sample 145) oils at different concentrations were determined. The IR fingerprints agree with results obtained from ...

  12. FT-IR and XRD analysis of coal from Makum coalfield of Assam

    Indian Academy of Sciences (India)

    High sulphur coal sample from Ledo colliery of Makum coalfield, Assam, India was studied using FT-IR and XRD methods. FT-IR study shows the presence of ... Function of Radial Distribution Analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite-like structure. The first maximum in the G() ...

  13. The Importance of Surface IrOx in Stabilizing RuO2 for Oxygen Evolution

    DEFF Research Database (Denmark)

    Escribano, Maria Escudero; Pedersen, Anders Filsøe; Paoli, Elisa Antares

    2017-01-01

    corrosion on IrOx/RuO2 thin films by combining electrochemical quartz crystal microbalance (EQCM) with inductively coupled mass spectrometry (ICP-MS). We elucidate the importance of sub-monolayer surface IrOx in minimizing Ru dissolution. Our work shows that we can tune the surface properties of active OER...

  14. The Effectiveness of Integrating Teaching Strategies into IRS Activities to Facilitate Learning

    Science.gov (United States)

    Wang, Y.-H.

    2017-01-01

    Previous studies on the interactive response system (IRS) have generally adopted the lecture method to facilitate teaching and learning, while few have made efforts to investigate the learning effects of instructional methods and IRS activities on learning and teaching. The purpose of the present study was therefore to explore whether the use of…

  15. A Study of IR Loss Correction Methodologies for Commercially Available Pyranometers

    Energy Technology Data Exchange (ETDEWEB)

    Long, Chuck; Andreas, Afshin; Augustine, John; Dooraghi, Mike; Habte, Aron; Hall, Emiel; Kutchenreiter, Mark; McComiskey, Allison; Reda, Ibrahim; Sengupta, Manajit

    2017-03-24

    This presentation provides a high-level overview of a study of IR Loss Connection Methodologies for Commercially Available Pyranometers. The IR Loss Corrections Study is investigating how various correction methodologies work for several makes and models of commercially available pyranometers in common use, both when operated in ventilators with DC fans and without ventilators, as when they are typically calibrated.

  16. Chirality-induced conformational preferences in peptide-metal ion binding revealed by IR spectroscopy

    NARCIS (Netherlands)

    Dunbar, R.C.; Steill, J.D.; Oomens, J.

    2011-01-01

    Chirality reversal of a residue in a peptide can change its mode of binding to a metal ion, as shown here experimentally by gas-phase IR spectroscopy of peptide−metal ion complexes. The binding conformations of Li+, Na+, and H+ with the ll and dl stereoisomers of PhePhe were compared through IR ion

  17. Chirality-Induced Conformational Preferences in Peptide-Metal Ion Binding Revealed by IR Spectroscopy

    NARCIS (Netherlands)

    Dunbar, R. C.; Steill, J. D.; Oomens, J.

    2011-01-01

    Chirality reversal of a residue in a peptide can change its mode of binding to a metal ion, as shown here experimentally by gas-phase IR spectroscopy of peptide metal ion complexes. The binding conformations of Li+, Na+, and H+ with the LL and DL stereoisomers of PhePhe were compared through IR ion

  18. Red-IR stimulated luminescence in K-feldspar: Single or multiple trap origin?

    DEFF Research Database (Denmark)

    Andersen, Martin Thalbitzer; Jain, Mayank; Tidemand-Lichtenberg, Peter

    2012-01-01

    We investigate on the origins of the infra-red stimulated luminescence (IRSL) signals in 3 potassium feldspars based on IR-red spectroscopy (700–1050 nm) using a fiber-coupled tunable Ti:Sapphire laser, in combination with different thermal and optical (pre)treatments of the samples. We also...

  19. $β'_{IR}$ at an Infrared Fixed Point in Chiral Gauge Theories

    DEFF Research Database (Denmark)

    Ryttov, Thomas A.; Shrock, Robert

    2018-01-01

    We present scheme-independent calculations of the derivative of the beta function, denoted $\\beta'_{IR}$, at a conformally invariant infrared (IR) fixed point, in several asymptotically free chiral gauge theories, namely SO($4k+2$) with $2 \\le k \\le 4$ with respective numbers $N_f$ of fermions...

  20. Sustained p16INK4aexpression is required to prevent IR-induced tumorigenesis in mice.

    Science.gov (United States)

    Palacio, L; Krishnan, V; Le, N L O; Sharpless, N E; Beauséjour, C M

    2017-03-02

    Exposure of murine and human tissues to ionizing radiation (IR) induces the expression of p16 INK4a , a tumor suppressor gene and senescence/aging biomarker. Increased p16 INK4a expression is often delayed several weeks post exposure to IR. In this context, it remains unclear if it occurs to suppress aberrant cellular growth of potentially transformed cells or is simply a result of IR-induced loss of tissue homeostasis. To address this question, we used a conditional p16 INK4a null mouse model and determined the impact of p16 INK4a inactivation long-term post exposure to IR. We found that, in vitro, bone marrow stromal cells exposed to IR enter DNA replication following p16 INK4a inactivation. However, these cells did not resume growth; instead, they mostly underwent cell cycle arrest in G2. Similarly, delayed inactivation of p16 INK4a in mice several weeks post exposure to IR resulted in increased BrdU incorporation and cancer incidence. In fact, we found that the onset of tumorigenesis was similar whether p16 INK4a was inactivated before or after exposure to IR. Overall, our results suggest that IR-induced p16 INK4a dependent growth arrest is reversible in mice and that sustained p16 INK4a expression is necessary to protect against tumorigenesis.

  1. FT-IR SOLUTION SPECTRA OF PROPYL SULFIDE, PROPYL SULFOXIDE, AND PROPYL SULFONE

    Science.gov (United States)

    FT-IR spectra were obtained of 0.5% volumetric solutions of propyl sulfide, propyl sulfoxide, and propyl sulfone in hexane, CCl4, CS2, and CHCl3 to assist in the assignment of FT-IR-PAS spectra of propyl sulfoxide sorbed within the structure of several peats and onto cellulose. T...

  2. Structured Reporting of IR Procedures: Effect on Report Compliance, Accuracy, and Satisfaction.

    Science.gov (United States)

    Nguyen, Quang; Sarwar, Ammar; Luo, Michael; Berkowitz, Seth; Ahmed, Muneeb; Brook, Olga R

    2018-03-01

    To compare effect of free-text versus structured reporting of IR procedures on report quality and report coding and value. In this retrospective study, 432 common consecutive free-text IR reports created during 4 months (from September 2013 to December 2013) before implementation of structured reporting (February 2014) and 415 structured IR reports created after implementation (from September 2014 to December 2014) were reviewed to assess ease of use and compliance with reporting requirements for regulatory requirements and coding. IR staff and trainees and referring physicians to IR were surveyed on procedure report attributes, such as detail, quality, and clarity. Structured reporting increased compliance with reporting fluoroscopy time, radiation dose, and contrast administration compared with free-text reports (402/432 [93.1%] vs 251/415 [60.5%], P IR physicians found structured reports to require less time to complete (21/26 [81%]), to be easier to complete (23/26 [89%]), and to have a similar or higher level of detail (19/26 [73%]) compared with free-text reports. Referring physicians were more satisfied with structured reports compared with free-text reports (6.9/10 vs 5.6/10, P = .03). Structured IR reporting compared with free-text reporting improves compliance with radiation dose and contrast reporting, reporting and coding efficiency, and satisfaction among IR and referring physicians. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  3. IR spectroscopy on jet-cooled isolated two-station rotaxanes

    NARCIS (Netherlands)

    Rijs, A.M.; Kay, E.R.; Leigh, D.A.; Buma, W.J.

    2011-01-01

    High-resolution IR spectroscopy has been employed to study isolated, switchable [2]rotaxanes. IR absorption spectra of two-station rotaxanes, their separate thread, and macrocycle components, as well as those of the individual stations incorporated into the thread, have been measured in the

  4. Intracavity upconversion for IR absorption lidar: Comparison of linear and ring cavity designs

    DEFF Research Database (Denmark)

    Meng, Lichun; Høgstedt, Lasse; Tidemand-Lichtenberg, Peter

    2017-01-01

    Upconversion detection is a promising technology for measurement of IR signals in the 1.5 μm–2 μm region used for lidar remote sensing [1-2]. In comparison to conventional InGaAs detector, the upconversion detector can achieve IR detection with better signal-to-noise ratio (SNR), not only due...

  5. IR's Role in Piloting an Assessment Model: Coordination, Consultation and Compromise

    Science.gov (United States)

    Sweatman, Robert A.

    2015-01-01

    This chapter focuses on IR's role in coordinating a pilot of the Degree Qualifications Profile (DQP) for assessment in a new master's degree program and provides guidance on frameworks that can be used, important technical considerations, and ways IR can be involved to advance the use of rubrics as a primary program assessment tool.

  6. An add-on system including a micro-reactor for an atr-ir spectrometer

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to an add-on system for an attenuated total reflectance infrared (ATR-IR) spectrometer, the add-on system allowing for time-resolved in situ IR measurements of heterogeneous mixtures. The add-on device comprises a micro-reactor (300A) forming a sample cavity (305) when...

  7. Pdx1 restores beta cell function in Irs2 knockout mice.

    Science.gov (United States)

    Kushner, Jake A; Ye, Jing; Schubert, Markus; Burks, Deborah J; Dow, Matthew A; Flint, Carrie L; Dutta, Sanjoy; Wright, Christopher V E; Montminy, Marc R; White, Morris F

    2002-05-01

    The homeodomain transcription factor Pdx1 is required for pancreas development, including the differentiation and function of beta cells. Mutations in Pdx1 or upstream hepatocyte nuclear factors cause autosomal forms of early-onset diabetes (maturity-onset diabetes of the young [MODY]). In mice, the Irs2 branch of the insulin/Igf signaling system mediates peripheral insulin action and pancreatic beta cell growth and function. To investigate whether beta cell failure in Irs2(-/-) mice might be related to dysfunction of MODY-related transcription factors, we measured the expression of Pdx1 in islets from young Irs2(-/-) mice. Before the onset of diabetes, Pdx1 was reduced in islets from Irs2(-/-) mice, whereas it was expressed normally in islets from wild-type or Irs1(-/-) mice, which do not develop diabetes. Whereas male Irs2(-/-)Pdx1(+/+) mice developed diabetes between 8 and 10 weeks of age, haploinsufficiency for Pdx1 caused diabetes in newborn Irs2(-/-) mice. By contrast, transgenic expression of Pdx1 restored beta cell mass and function in Irs2(-/-) mice and promoted glucose tolerance throughout life, as these mice survived for at least 20 months without diabetes. Our results suggest that dysregulation of Pdx1 might represent a common link between ordinary type 2 diabetes and MODY.

  8. Reviewing History and IR Journals : Academic Publication Practices and Dominance in World Society

    NARCIS (Netherlands)

    Duijvendak, Maarten; de Wilde, J.H.

    2016-01-01

    1 Reviewing History and IR Journals: Academic Publication Practices and dominance in World Society Maarten Duijvendak & Jaap de Wilde Groningen, 2016 This article reflects on analyses of academic History journals and International Relations (IR) journals conducted by students in our Research

  9. Initial study of a method for IR measurements in boilers; Inledande studie av metod foer IR-maetning i aangpannor

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, Martin; Joensson, Magnus; Lundin, Leif [Swedish National Testing and Research Inst., Boraas (Sweden)

    1999-10-01

    The tubes in steam boilers are required to be regularly inspected, in order to find water-side deposits, thinning of walls or material defects. This is for safety, problem-free operation and high availability. No non-destructive method of inspection is available today for finding deposits on the insides of boiler tubes. Nor is there any method that can not only detect deposits on the insides of the tubes but also monitor the tubes' wall thicknesses. A suitable method - reliable, safe, easy to use and cost-efficient - is therefore needed. One such method is to measure the surface temperature of a larger area of the diaphragm wall, using a non-contact method, and from the resulting information to assess the material thickness and possible water-side or steam-side deposits. An IR camera is used for non-contact measurement of the radiated energy from several adjacent surface elements, and thus also of their temperature. The temperature is displayed on the camera's screen to produce a picture of the temperature distribution. This is a well-established method today, and is used in applications such as the steel industry, the electricity industry, electronics and health care. The surface temperatures of the tube walls can be measured by inserting an IR camera on an arm into the combustion chamber, without anyone having to get inside the boiler. The combustion chamber is the part of the boiler that is of main interest for inspection, as it is the easiest to reach. Measurements are facilitated by higher temperatures and thus higher heat fluxes through the tube walls. Diaphragm wall temperatures can be measured quickly and rationally over large areas. Points of interest in inspections include determining where there are water-side deposits in the tubes, where tubes are thin, where flow is obstructed and where there might be material defects. With the exception of material defects, all of these mechanisms result in changes in the surface temperature, which in many

  10. Absorption, phosphorescence and Raman spectra of IrQ(ppy){sub 2} organometallic compound

    Energy Technology Data Exchange (ETDEWEB)

    Polosan, Silviu, E-mail: silv@infim.ro [National Institute of Materials Physics, R-77125 Bucharest-Magurele (Romania); Ciobotaru, Iulia Corina [National Institute of Materials Physics, R-77125 Bucharest-Magurele (Romania); Tsuboi, Taiju [Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan)

    2015-07-15

    The absorption and photoluminescence (PL) spectra, PL decays, Raman spectrum, cyclic voltammetry (CV) and nuclear magnetic resonance of heteroleptic Ir-compound IrQ(ppy){sub 2} compound with two phenylpyridine (ppy) ligands and one quinoline (Q) ligand have been investigated experimentally and theoretically. Two very weak absorption bands due to the transitions to the triplet states are found at about 560 and 595 nm in IrQ(ppy){sub 2} doped in CH{sub 2}Cl{sub 2} solution. IrQ(ppy){sub 2} exhibits a dual emission of red and green phosphorescence bands. The red emission intensity is much higher than the green one in IrQ(ppy){sub 2} powder, but much lower than the green one in lightly IrQ(ppy){sub 2}-doped CH{sub 2}Cl{sub 2} solution and PMMA film. The intensity ratio of the red emission to the green emission, however, is observed to increase with increasing the IrQ(ppy){sub 2} concentration in CH{sub 2}Cl{sub 2} solution and PMMA film. The enhancement of the red emission is suggested to be caused by the Forester energy transfer from Ir-ppy component to Ir–Q components between two neighboring IrQ(ppy){sub 2} molecules. The HOMO energy is estimated to be −4.865 eV from the CV measurement, which is close to the HOMO energy of −4.844 eV calculated using the time dependent density function theory (TD-DFT). The LUMO energy is estimated as −2.856 eV from the HOMO energy and the long-wavelength absorption edge found at 617 nm in the absorption spectrum. The absorption spectrum of IrQ(ppy){sub 2} is calculated by the TD-DFT. Discussion is given on a deviation of the calculated spectrum from the measured spectrum. - Graphical abstract: Display Omitted - Highlights: • IrQ(ppy){sub 2} has red and green emissions of different ratio between film and solution. • Intensity ratio of red to green emissions increases with IrQ(ppy){sub 2} concentration. • Enhancement of red emission is due to energy transfer in two neighboring IrQ(ppy){sub 2}. • Lowest-energy absorption

  11. Mechanism of CO 2 Fixation by Ir I -X Bonds (X = OH, OR, N, C)

    KAUST Repository

    Vummaleti, Sai V. C.

    2015-09-08

    Density functional theory calculations have been used to investigate the CO2 fixation mechanism proposed by Nolan et al. for the IrI complex [Ir(cod)(IiPr)(OH)] (1; cod = 1,5-cyclooctadiene; IiPr = 1,3-diisopropylimidazol-2-ylidene) and its derivatives. For 1, our results suggest that CO2 insertion is the rate-limiting step rather than the dimerization step. Additionally, in agreement with the experimental results, our results show that CO2 insertion into the Ir-OR1 (R1 = H, methyl, and phenyl) and Ir-N bonds is kinetically facile, and the calculated activation energies span a range of only 12.0-23.0 kcal/mol. Substantially higher values (35.0-50.0 kcal/mol) are reported for analogous Ir-C bonds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. IrPdRu/C as H2Oxidation Catalysts for Alkaline Fuel Cells.

    Science.gov (United States)

    Wang, Hongsen; Abruña, Héctor D

    2017-05-24

    H 2 oxidation kinetics on Pt in alkaline media are very sluggish, being over 100 times slower than in acidic media, and thus, new and more active H 2 oxidation electrocatalysts must be developed in order to enable alkaline exchange membrane fuel cells (AEMFCs). In this Communication, we present a new type of catalysts-carbon-supported IrPdRu nanoparticles-as H 2 oxidation catalysts in alkaline media. These catalysts exhibit higher activity than Pt/C and Ir/C catalysts and are also quite stable. In particular, Ir 3 Ru 7 /C and Ir 3 Pd 1 Ru 6 /C catalysts are significantly more active and less expensive than Pt/C and Ir/C, and are thus promising new anode catalysts for alkaline fuel cell applications.

  13. Miesto nuotekų dumblo ir maisto atliekų perdirbimo į biodujas tyrimas

    OpenAIRE

    Pilipavičius, Vilmantas

    2011-01-01

    Lietuvoje susidaro nemaži nuotekų dumblo kiekiai, kurių susidarymą sąlygoje gyventojų ir iš pramonės įmonių atitekančios nuotekos. Tinkamai paruoštas nuotekų dumblas, gali būti naudojamas kaip trąša žemės ūkyje ir kaip kuras energetikoje (tiesiogiai ar kaip žaliava biodujų gamybai). Dumblą apdoroti ir išgauti energiją galima įdiegiant bioreaktorius. Darbo tikslas: ištirti nuotekų dumblo ir maisto atliekų mišinio anaerobinio perdirbimo į biodujas galimybes ir įvertinti jų energinį potencialą. ...

  14. Pulsating stars in ω Centauri. Near-IR properties and period-luminosity relations

    Directory of Open Access Journals (Sweden)

    Navarrete Camila

    2017-01-01

    Full Text Available ω Centauri (NGC 5139 contains many variable stars of different types, including the pulsating type II Cepheids, RR Lyrae and SX Phoenicis stars. We carried out a deep, wide-field, near-infrared (IR variability survey of ω Cen, using the VISTA telescope. We assembled an unprecedented homogeneous and complete J and KS near-IR catalog of variable stars in the field of ω Cen. In this paper we compare optical and near-IR light curves of RR Lyrae stars, emphasizing the main differences. Moreover, we discuss the ability of near-IR observations to detect SX Phoenicis stars given the fact that the amplitudes are much smaller in these bands compared to the optical. Finally, we consider the case in which all the pulsating stars in the three different variability types follow a single period-luminosity relation in the near-IR bands.

  15. Photon transferred TL signals from potassium feldspars and their effects on post-IR IRSL measurements

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Jintang [State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029 (China); Chen, Jie, E-mail: chenjie@ies.ac.cn [State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029 (China); Salisbury, James Barrett [School of Earth and Space Exploration, Arizona State University, Tempe 85287 (United States)

    2015-04-15

    A recent flourish of studies using post-infrared infrared stimulated luminescence (post-IR IRSL) signals for retrospective dose determinations necessitates the investigation of photon transferred thermoluminescence (PTTL) signals induced by IR stimulation for potassium feldspars (K-feldspars). In this study, we investigated characteristics of PTTL signals and their effects on post-IR IRSL measurements for K-feldspars extracted from two bedrock samples. The temperature corresponding to maximum PTTL intensity (T{sub peak}) and the highest temperature at which PTTL signals are observed (T{sub max}) increase with the preheat temperature before IR stimulation, although no further increment of T{sub peak} is observed when preheat is higher than 320 °C. The interference of the PTTL signal with the post-IR IRSL signal is non-monotonically dependent upon the temperature of the latter. The PTTL signals lead to an underestimation of the thermal stability of multiple-elevated-temperature (MET)-post-IR IRSL{sub 290} signals and may contribute to poor dose recovery ratios (DRR) using post-IR IRSL{sub 290} signals. The DRR values are substantially improved when the temperatures of preheat and post-IR IR stimulation are elevated to suppress the interference of the PTTL signal. This study highlights the importance of a careful inspection on PTTL signals before measuring the post-IR IRSL signals for K-feldspars. - Highlights: • PTTL signals show major dependence on preheat temperature. • PTTL signals cause underestimation of thermal stability for MET-pIRIR{sub 290} signals. • High temperature pIRIR suppresses PTTL signals and improves dose recovery ratios.

  16. Synthesis of Iridium(III) Carboxamides via the Bimetallic Reaction between Cp(PMe(3))IrPh(OH) and [Cp(PMe(3))Ir(Ph)NCR](+).

    Science.gov (United States)

    Tellers, David M.; Ritter, Joachim C. M.; Bergman, Robert G.

    1999-10-18

    Reaction of Cp(PMe(3))IrPh(OH) (1) with nitriles is undetectably slow in benzene solution at room temperature. However, in the presence of Cp(PMe(3))IrPh(OTf) (2) (OTf = O(3)SCF(3)), the reaction is strongly catalyzed, leading to iridium(III) carboxamides Cp(PMe(3))IrPh[NHC(O)R] (6a-d) [R = C(6)H(4)CH(3) (6a), C(6)H(5) (6b), C(6)H(4)CF(3) (6c), CH(3) (6d)]. We propose that these transformations occur by initial displacement of the trifluoromethanesulfonate ("triflate") anion of 2 by a molecule of nitrile, leading to a nitrile-substituted iridium cation, [Cp(PMe(3))IrPh(NCR)](+) (10). Following this, the nucleophilic hydroxide group of 1 attacks the (activated) nitrile molecule bound in 10, leading (after proton transfer) to the iridium carboxamide complex. In the case of nitriles possessing hydrogens alpha to the cyano group, competitive loss of one of these protons is observed, leading to iridium C-bound cyanoenolates such as Cp(PMe(3))(Ph)Ir(CH(2)CN) (7). Protonolysis of carboxamides 6a-d with HCl yields Cp(PMe(3))IrPh(Cl) (9) and the free amides. A pronounced solvent effect is observed when the reaction between 1 and nitriles catalyzed by 2 is carried out in THF solution. The basic hydroxide ligand of 1 induces an overall dehydration/cyclization reaction of the coordinated aromatic nitrile. For example, the reaction of 1 with p-trifluorotolunitrile and a catalytic amount of 2 leads to the formation of 6c, water, [Ph(PMe(3))Ir[C(5)Me(4)CH(2)C(C(6)H(4)CF(3))N

  17. The relationship between visfatin and HOMA-IR in hypertensive patients, and the effect of antihypertensive drugs on visfatin and HOMA-IR in hypertensive patients with insulin resistance.

    Science.gov (United States)

    Lan, Jianjun; Chen, Xiaoni; Chen, Xiaoping; Wang, Si; Zhang, Xin; Wu, Kai; He, Sen; Peng, Yong; Jiang, Lingyun; Li, Longxin; Wan, Liyan

    2011-10-01

    To investigate the correlation between serum visfatin and insulin resistance (IR) in non-diabetic essential hypertensive (EH) patients with and without IR, and to evaluate the effect of antihypertensive treatment on serum visfatin and IR in these patients. A total of 81 non-diabetic EH patients, including 54 with IR and 27 without IR, were enrolled. After two weeks wash-out, patients with IR were randomly assigned to telmisartan (group T) or amlodipine (group A) for 6 months. Blood samples were taken before and after treatment for measurement of routine biochemical parameters, visfatin and insulin resistance (measured by HOMA-IR). Visfatin was independently correlated with HOMA-IR (r=0.845, P=0.000). After 6 months of treatment, both drugs lowered HOMA-IR, more significantly so in group T than group A (P=0.010). Serum visfatin levels increased in group T but decreased in group A. Serum visfatin levels were higher in non-diabetic EH patients with IR compared with those without IR. Visfatin is independently correlated with HOMA-IR. Telmisartan lowers HOMA-IR to a greater extent than amlodipine. Interestingly, serum visfatin increased with telmisartan yet decreased with amlodipine treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. Constraining Cometary Crystal Shapes from IR Spectral Features

    Science.gov (United States)

    Wooden, D. H.; Lindsay, S.; Harker, D. E.; Kelley, M. S.; Woodward, C. E.; Murphy, J. R.

    2013-12-01

    A major challenge in deriving the silicate mineralogy of comets is ascertaining how the anisotropic nature of forsterite crystals affects the spectral features' wavelength, relative intensity, and asymmetry. Forsterite features are identified in cometary comae near 10, 11.05-11.2, 16, 19, 23.5, 27.5 and 33 μm [1-10], so accurate models for forsterite's absorption efficiency (Qabs) are a primary requirement to compute IR spectral energy distributions (SEDs, λFλ vs. λ) and constrain the silicate mineralogy of comets. Forsterite is an anisotropic crystal, with three crystallographic axes with distinct indices of refraction for the a-, b-, and c-axis. The shape of a forsterite crystal significantly affects its spectral features [13-16]. We need models that account for crystal shape. The IR absorption efficiencies of forsterite are computed using the discrete dipole approximation (DDA) code DDSCAT [11,12]. Starting from a fiducial crystal shape of a cube, we systematically elongate/reduce one of the crystallographic axes. Also, we elongate/reduce one axis while the lengths of the other two axes are slightly asymmetric (0.8:1.2). The most significant grain shape characteristic that affects the crystalline spectral features is the relative lengths of the crystallographic axes. The second significant grain shape characteristic is breaking the symmetry of all three axes [17]. Synthetic spectral energy distributions using seven crystal shape classes [17] are fit to the observed SED of comet C/1995 O1 (Hale-Bopp). The Hale-Bopp crystalline residual better matches equant, b-platelets, c-platelets, and b-columns spectral shape classes, while a-platelets, a-columns and c-columns worsen the spectral fits. Forsterite condensation and partial evaporation experiments demonstrate that environmental temperature and grain shape are connected [18-20]. Thus, grain shape is a potential probe for protoplanetary disk temperatures where the cometary crystalline forsterite formed. The

  19. 2-Ethynylpyridine dimers: IR spectroscopic and computational study

    Science.gov (United States)

    Bakarić, Danijela; Spanget-Larsen, Jens

    2018-04-01

    2-ethynylpyridine (2-EP) presents a multifunctional system capable of participation in hydrogen-bonded complexes utilizing hydrogen bond donating (tbnd Csbnd H, Aryl-H) and hydrogen bond accepting functions (N-atom, Ctbnd C and pyridine π-systems). In this work, IR spectroscopy and theoretical calculations are used to study possible 2-EP dimer structures as well as their distribution in an inert solvent such as tetrachloroethene. Experimentally, the tbnd Csbnd H stretching vibration of the 2-EP monomer absorbs close to 3300 cm-1, whereas a broad band with maximum around 3215 cm-1 emerges as the concentration rises, indicating the formation of hydrogen-bonded complexes involving the tbnd Csbnd H moiety. The Ctbnd C stretching vibration of monomer 2-EP close to 2120 cm-1 is, using derivative spectroscopy, resolved from the signals of the dimer complexes with maximum around 2112 cm-1. Quantum chemical calculations using the B3LYP + D3 model with counterpoise correction predict that the two most stable dimers are of the π-stacked variety, closely followed by dimers with intermolecular tbnd Csbnd H⋯N hydrogen bonding; the predicted red shifts of the tbnd Csbnd H stretching wavenumbers due to hydrogen bonding are in the range 54-120 cm-1. No species with obvious hydrogen bonding involving the Ctbnd C or pyridine π-systems as acceptors are predicted. Dimerization constant at 25 °C is estimated to be K2 = 0.13 ± 0.01 mol-1 dm3.

  20. Clinical Application of Renograph IR-03 for the Hospital

    Directory of Open Access Journals (Sweden)

    R. Isaris

    2012-08-01

    Full Text Available The renography using renograph is one of clinical modality to investigate the renal function among other such as laboratory medical check up and X-rays. The prototype of renograph IR-03 designed by BATAN has been constructed and the laboratory tests as well as clinical tests have been carried out at PRPN-BATAN Serpong and General Hospital Dr. Sardjito Jogyakarta, respectively. Cost associated with the clinical use of renograph at the hospital are analyzed according to the two major components: radiopharmaceutical cost and the use of equipment. Annual cost of operational of renograph by estimate number of patient is about 2,000 is IDR. 30.0 millions for radiopharmaceutical 131Iodine. Total Direct Cost is about IDR. 212.5 millions and the Capital Cost for one unit renograph is IDR. 250 millions. The Break Event Point of invest one unit renograph is 1194 procedures (0.597%, or about IDR. 209,475 millions, which the cost for each procedure is IDR. 85,000.-. This value is depending on several variables, especially number of procedure can be reached. The cash flow analyses by Rate of Return (ROR showed that the value of i* is 22.6% is much greater than the value of MARR or saving rate of interest in the Bank now is about < 10%. The Payback Period calculation to see on how interesting the investment of renograph and its prospect for application in the hospitals showed about 1.818 years, that is good prospect economically