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Sample records for near-infrared core source

  1. Near-infrared photocatalysis based on YF3 : Yb3+,Tm3+/TiO2 core/shell nanoparticles.

    Science.gov (United States)

    Qin, Weiping; Zhang, Daisheng; Zhao, Dan; Wang, Lili; Zheng, Kezhi

    2010-04-07

    We report the novel near-infrared (NIR) photocatalysis of YF(3) : Yb(3+),Tm(3+)/TiO(2) core/shell nanoparticles. The core/shell nanoparticles show photocatalytic activity under the NIR irradiation. This study demonstrates that the NIR energy can be used as the driving source for photocatalysis besides the UV and visible energy.

  2. Rapid Estimation of Microfibril Angle of Increment Cores of Chinese Fir by Near Infrared Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Near infrared (NIR) spectroscope and X-ray diffractometry have been used for rapid prediction of the microfibril angle (MFA) which is one of the important factors affecting wood properties. Wood property evaluation in breeding and resource evaluation requires effective and rapid analysis methods for thousands of samples. In the experiment, all samples from increment cores with moisture content of 60% to 150% were used for measuring MFA by X-ray scanning diffractometry. Then, a partial least squares regressi...

  3. Study of Fast, Near-Infrared Photodetectors for the ITER Core LIDAR Thomson Scattering

    Science.gov (United States)

    Giudicotti, L.; Pasqualotto, R.; Alfier, A.; Beurskens, M.; Kempenaars, M.; Walsh, M. J.

    2008-03-01

    A key component for the ITER core LIDAR Thomson Scattering (TS) diagnostic would be a detector with good sensitivity in the 850-1060 nm near infrared (NIR) spectral region. Covering this spectral region becomes necessary if a Nd:YAG laser system operating at λ = 1.06 μm is used as the laser source, which is a very attractive choice in terms of available energy, repetition rate, reliability and cost. In this paper we review the state of the art of two types of detectors available for the above spectral range: the transferred electron (TE) InGaAs/InP hybrid photodiode and the InxGa1-xAs microchannel plate (MCP) image intensifier and we describe the advancements necessary for a possible application in the ITER LIDAR TS. In addition we describe the preliminary characterization of new GaAsP fast MCP photomultipliers (PMTs) suitable for the detection of the visible part of the LIDAR TS spectrum in JET and ITER.

  4. Incoherent photon conversion in selectively infiltrated hollow-core photonic crystal fibers for single photon generation in the near infrared.

    Science.gov (United States)

    Jiang, Ping; Schroeder, Tim; Bath, Michael; Lesnyak, Vladimir; Gaponik, Nikolai; Eychmüller, Alexander; Benson, Oliver

    2012-05-07

    At present, there exist a number of on-demand single photon sources with high emission rates and stability even at room temperature. However, their emission wavelength is restricted to specific transitions in single quantum emitters. Single photon generation in the near infrared, possibly within the telecom band, though most urgently needed, is particularly crucial. In this paper, we suggest an experimental method to convert visible single photons from a defect center in diamond to the near infrared. The conversion relies on efficient absorption by colloidal quantum dots and subsequent Stokes-shifted emission. The desired target wavelength can be chosen almost arbitrarily by selecting quantum dots with a suitable emission spectrum. A hollow core photonic crystal fiber selectively filled with a solution of quantum dots was used to achieve at the same time a single photon absorption probability of near unity and a very high re-collection efficiency of Stokes-shifted fluorescence (theoretically estimated to be 26%). A total conversion efficiency of light of 0.1% is achieved. Experimental strategies to significantly enhance this number are presented.

  5. Room temperature triggered single-photon source in the near infrared

    Energy Technology Data Exchange (ETDEWEB)

    Wu, E [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, Ecole Normale Superieure de Cachan (France); Rabeau, J R [Department of Physics, Macquarie University, Sydney, New South Wales 2109 (Australia); Roger, G [Laboratoire Charles Fabry de l' Institut d' Optique, UMR CNRS 8501, Palaiseau (France); Treussart, F [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, Ecole Normale Superieure de Cachan (France); Zeng, H [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China (China); Grangier, P [Laboratoire Charles Fabry de l' Institut d' Optique, UMR CNRS 8501, Palaiseau (France); Prawer, S [Centre of Excellence for Quantum Computer Technology and Quantum Communications Victoria, School of Physics, University of Melbourne, Victoria 3010 (Australia); Roch, J-F [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, Ecole Normale Superieure de Cachan (France)

    2007-12-15

    We report the realization of a solid-state triggered single-photon source with narrow emission in the near infrared at room temperature. It is based on the photoluminescence of a single nickel-nitrogen NE8 colour centre in a chemical vapour deposited diamond nanocrystal. Stable single-photon emission has been observed in the photoluminescence under both continuous-wave and pulsed excitations. The realization of this source represents a step forward in the application of diamond-based single-photon sources to quantum key distribution (QKD) under practical operating conditions.

  6. [The evaluation of hydrocarbon potential generation for source rocks by near-infrared diffuse reflection spectra].

    Science.gov (United States)

    Zhang, Yu-Jia; Xu, Xiao-Xuan; Song, Ning; Wu, Zhong-Chen; Zhou, Xiang; Chen, Jin; Cao, Xue-Wei; Wang, Bin

    2011-04-01

    Near-infrared (NIR) and mid-infrared (MIR) diffuse reflection spectra were compared and evaluated for hydrocarbon potential generation of source rocks. Near-infrared diffuse reflectance often exhibits significant differences in the spectra due to the non-homogeneous distribution of the particles, so the signal-to-noise ratio of NIR is much lower than MIR It is too difficult to get accurate results by NIR without using a strong spectral preprocessing method to remove systematic noise such as base-line variation and multiplicative scatter effects. In the present paper, orthogonal signal correction (OSC) and an improved algorithm of it, i.e. direct orthogonal signal correction (DOSC), are used as different methods to preprocess both the NIR and MIR spectra of the hydrocarbon source rocks. Another algorithm, wavelet multi-scale direct orthogonal signal correction (WMDOSC), which is a combination of discrete wavelet transform (DWT) and DOSC, is also used as a preprocessing method. Then, the calibration model of hydrocarbon source rocks before and after pretreatment was established by interval partial least square (iPLS). The experimental results show that WMDOSC is more successfully applied to preprocess the NIR spectra data of the hydrocarbon source rocks than other two algorithms, and NIR performed as good as MIR in the analysis of hydrocarbon potential generation of source rocks with WMDOSC-iPLS pretreatment calibration model.

  7. Long distance active hyperspectral sensing using high-power near-infrared supercontinuum light source.

    Science.gov (United States)

    Manninen, Albert; Kääriäinen, Teemu; Parviainen, Tomi; Buchter, Scott; Heiliö, Miika; Laurila, Toni

    2014-03-24

    A hyperspectral remote sensing instrument employing a novel near-infrared supercontinuum light source has been developed for active illumination and identification of targets. The supercontinuum is generated in a standard normal dispersion multi-mode fiber and has 16 W total optical output power covering 1000 nm to 2300 nm spectral range. A commercial 256-channel infrared spectrometer was used for broadband infrared detection. The feasibility of the presented hyperspectral measurement approach was investigated both indoors and in the field. Reflection spectra from several diffusive targets were successfully measured and a measurement range of 1.5 km was demonstrated.

  8. Near infrared spectral imaging of explosives using a tunable laser source

    Energy Technology Data Exchange (ETDEWEB)

    Klunder, G L; Margalith, E; Nguyen, L K

    2010-03-26

    Diffuse reflectance near infrared hyperspectral imaging is an important analytical tool for a wide variety of industries, including agriculture consumer products, chemical and pharmaceutical development and production. Using this technique as a method for the standoff detection of explosive particles is presented and discussed. The detection of the particles is based on the diffuse reflectance of light from the particle in the near infrared wavelength range where CH, NH, OH vibrational overtones and combination bands are prominent. The imaging system is a NIR focal plane array camera with a tunable OPO/laser system as the illumination source. The OPO is programmed to scan over a wide spectral range in the NIR and the camera is synchronized to record the light reflected from the target for each wavelength. The spectral resolution of this system is significantly higher than that of hyperspectral systems that incorporate filters or dispersive elements. The data acquisition is very fast and the entire hyperspectral cube can be collected in seconds. A comparison of data collected with the OPO system to data obtained with a broadband light source with LCTF filters is presented.

  9. Strategies for Imaging Faint Extended Sources in the Near-Infrared

    CERN Document Server

    Vaduvescu, O; Vaduvescu, Ovidiu; Call, Marshall L. Mc

    2004-01-01

    Quantitative information about variations in the background at J and K' are presented and used to develop guidelines for the acquisition and reduction of ground-based images of faint extended sources in the near-infrared, especially those which occupy a significant fraction of the field of view of a detector or which are located in areas crowded with foreground or background sources. Findings are based primarily upon data acquired over three photometric nights with the 3.6x3.6 arcmin CFHT-IR array on the Canada-France-Hawaii Telescope atop Mauna Kea. Although some results are specific to CFHT, overall conclusions should be useful in guiding observing and reduction strategies of extended objects elsewhere.

  10. THREE NEW GALACTIC CENTER X-RAY SOURCES IDENTIFIED WITH NEAR-INFRARED SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    DeWitt, Curtis [Department of Physics, University of California, Davis, CA 95616 (United States); Bandyopadhyay, Reba M.; Eikenberry, Stephen S.; Sarajedini, Ata [Department of Astronomy, University of Florida, 211 Bryant Space Center, P.O. Box 112055, Gainesville, FL 32611 (United States); Sellgren, Kris [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Blum, Robert; Olsen, Knut [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Bauer, Franz E., E-mail: curtis.n.dewitt@nasa.gov [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile)

    2013-11-01

    We have conducted a near-infrared spectroscopic survey of 47 candidate counterparts to X-ray sources discovered by the Chandra X-Ray Observatory near the Galactic center (GC). Though a significant number of these astrometric matches are likely to be spurious, we sought out spectral characteristics of active stars and interacting binaries, such as hot, massive spectral types or emission lines, in order to corroborate the X-ray activity and certify the authenticity of the match. We present three new spectroscopic identifications, including a Be high-mass X-ray binary (HMXB) or a γ Cassiopeiae (Cas) system, a symbiotic X-ray binary, and an O-type star of unknown luminosity class. The Be HMXB/γ Cas system and the symbiotic X-ray binary are the first of their classes to be spectroscopically identified in the GC region.

  11. Near-Infrared Image Reconstruction of Newborns' Brains: Robustness to Perturbations of the Source/Detector Location.

    Science.gov (United States)

    Ahnen, L; Wolf, M; Hagmann, C; Sanchez, S

    2016-01-01

    The brain of preterm infants is the most vulnerable organ and can be severely injured by cerebral ischemia. We are working on a near-infrared imager to early detect cerebral ischemia. During imaging of the brain, movements of the newborn infants are inevitable and the near-infrared sensor has to be able to function on irregular geometries. Our aim is to determine the robustness of the near-infrared image reconstruction to small variations of the source and detector locations. In analytical and numerical simulations, the error estimations for a homogeneous medium agree well. The worst case estimates of errors in reduced scattering and absorption coefficient for distances of r=40 mm are acceptable for a single source-detector pair. The optical properties of an inhomogeneity representing an ischemia are reconstructed correctly within a homogeneous medium, if the error in placement is random.

  12. A systematic search for near-infrared counterparts of nearby ultraluminous X-ray sources (II)

    Science.gov (United States)

    López, K. M.; Heida, M.; Jonker, P. G.; Torres, M. A. P.; Roberts, T. P.; Walton, D. J.; Moon, D.-S.; Harrison, F. A.

    2017-07-01

    We present the results of our continued systematic search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within 10 Mpc. We observed 42 ULXs in 24 nearby galaxies and detected NIR candidate counterparts to 15 ULXs. Fourteen of these ULXs appear to have a single candidate counterpart in our images and the remaining ULX has two candidate counterparts. Seven ULXs have candidate counterparts with absolute magnitudes in the range between -9.26 and -11.18 mag, consistent with them being red supergiants (RSGs). The other eight ULXs have candidate counterparts with absolute magnitudes too bright to be a single stellar source. Some of these NIR sources show extended morphology or colours expected for active galactic nuclei (AGNs), strongly suggesting that they are likely stellar clusters or background galaxies. The RSG candidate counterparts form a valuable sample for follow-up spectroscopic observations to confirm their nature, with the ultimate goal of directly measuring the mass of the compact accretor that powers the ULX using binary Doppler shifts.

  13. Near-infrared spectroscopy of 20 new Chandra sources in the Norma Arm

    CERN Document Server

    Rahoui, Farid; Fornasini, Francesca M; Bodaghee, Arash; Bauer, Franz E

    2014-01-01

    We report on CTIO/NEWFIRM and CTIO/OSIRIS photometric and spectroscopic observations of 20 new X-ray (0.5-10 keV) emitters discovered in the Norma Arm Region Chandra Survey (NARCS). NEWFIRM photometry was obtained to pinpoint the near-infrared counterparts of NARCS sources, while OSIRIS spectroscopy was used to help identify 20 sources with possible high mass X-ray binary properties. We find that (1) two sources are WN8 Wolf-Rayet stars, maybe in colliding wind binaries, part of the massive star cluster Mercer 81; (2) two are emission-line stars, possibly in X-ray binaries, that exhibit near- and mid-infrared excesses either due to free-free emission from the decretion discs of Be stars or warm dust in the stellar winds of peculiar massive stars such as B[e] supergiants or luminous blue variables; (3) one is a B8-A3 IV-V star that could be in a quiescent high mass X-ray binary system; (4) two are cataclysmic variables including one intermediate polar; (5) three may be neutron star symbiotic binaries; (6) five...

  14. Near-infrared-absorbing gold nanopopcorns with iron oxide cluster core for magnetically amplified photothermal and photodynamic cancer therapy.

    Science.gov (United States)

    Bhana, Saheel; Lin, Gan; Wang, Lijia; Starring, Hunter; Mishra, Sanjay R; Liu, Gang; Huang, Xiaohua

    2015-06-03

    We present the synthesis and application of a new type of dual magnetic and plasmonic nanostructures for magnetic-field-guided drug delivery and combined photothermal and photodynamic cancer therapy. Near-infrared-absorbing gold nanopopcorns containing a self-assembled iron oxide cluster core were prepared via a seed-mediated growth method. The hybrid nanostructures are superparamagnetic and show great photothermal conversion efficiency (η=61%) under near-infrared irradiation. Compact and stable nanocomplexes for photothermal-photodynamic therapy were formed by coating the nanoparticles with near-infrared-absorbing photosensitizer silicon 2,3-naphthalocyannie dihydroxide and stabilization with poly(ethylene glycol) linked with 11-mercaptoundecanoic acid. The nanocomplex showed enhanced release and cellular uptake of the photosensitizer with the use of a gradient magnetic field. In vitro studies using two different cell lines showed that the dual mode photothermal and photodynamic therapy with the assistance of magnetic-field-guided drug delivery dramatically improved the therapeutic efficacy of cancer cells as compared to the combination treatment without using a magnetic field and the two treatments alone. The "three-in-one" nanocomplex has the potential to carry therapeutic agents deep into a tumor through magnetic manipulation and to completely eradicate tumors by subsequent photothermal and photodynamic therapies without systemic toxicity.

  15. Near-Infrared Emitting CuInSe2/CuInS2 Dot Core/Rod Shell Heteronanorods by Sequential Cation Exchange

    OpenAIRE

    2015-01-01

    The direct synthesis of heteronanocrystals (HNCs) combining different ternary semiconductors is challenging and has not yet been successful. Here, we report a sequential topotactic cation exchange (CE) pathway that yields CuInSe2/CuInS2 dot core/rod shell nanorods with near-infrared luminescence. In our approach, the Cu+ extraction rate is coupled to the In3+ incorporation rate by the use of a stoichiometric trioctylphosphine-InCl3 complex, which fulfills the roles of both In-source and Cu-ex...

  16. Near-infrared emitting CuInSe_{2}/CuInS_{2} dot core/rod shell heteronanorods by sequential cation exchange

    OpenAIRE

    2015-01-01

    Abstract: The direct synthesis of heteronanocrystals (HNCs) combining different ternary semiconductors is challenging and has not yet been successful. Here, we report a sequential topotactic cation exchange (CE) pathway that yields CuInSe2/CuInS2 dot core/rod shell nanorods with near-infrared luminescence. In our approach, the Cu+ extraction rate is coupled to the In3+ incorporation rate by the use of a stoichiometric trioctylphosphine-InCl3 complex, which fulfills the roles of both In-source...

  17. Investigation into classification/sourcing of suspect counterfeit Heptodintrade mark tablets by near infrared chemical imaging.

    Science.gov (United States)

    Lopes, Marta B; Wolff, Jean-Claude

    2009-02-02

    Near infrared chemical imaging (NIR-CI) analysis was performed on 55 counterfeit Heptodin tablets obtained from a market survey and an additional 11 authentic Heptodin tablets for comparison. The aim of the study was to investigate whether NIR-CI can be used to detect the counterfeit tablets and to classify/source them so as to understand the possible number of origins to aid investigators and authorities to shut down counterfeiting operations. NIR-CI combined with multivariate analysis is particularly suited to compare chemical and physical properties of samples, since it is a quick and non-destructive method of analysis. Counterfeit tablets were easily distinguished from the authentic ones. Principal component analysis (PCA) and k-means clustering were performed on the data set. The results from both analyses grouped the counterfeit tablets in 13 main groups. The main groups found with both methods were quite consistent. Out of the 55 tablets only 18% contained the correct active pharmaceutical ingredient (API), i.e., the anti-viral drug lamivudine. The remaining 82% of counterfeit tablets contained talc and starch as main excipients. The API containing tablets classified into three main groups, based mainly on the amount of lamivudine present in the tablet. The group which had close to the correct amount of lamivudine sub-classified into three groups. From the analysis carried out, it is likely that the counterfeit tablets originate from as many as 15 different sources.

  18. Near-Infrared Properties of Faint X-rays Sources from NICMOS Imaging in the Chandra Deep Fields

    CERN Document Server

    Colbert, J W; Yan, L; Malkan, M A; McCarthy, P; Colbert, James W.; Teplitz, Harry; Yan, Lin; Malkan, Matthew; Carthy, Patrick Mc

    2004-01-01

    We measure the near-infrared properties of 42 X-ray detected sources from the Chandra Deep Fields North and South, the majority of which lie within the NICMOS Hubble Deep Field North and Ultra Deep Field. We detect all 42 Chandra sources with NICMOS, with 95% brighter than H = 24.5. We find that X-ray sources are most often in the brightest and most massive galaxies. Neither the X-ray fluxes nor hardness ratios of the sample show any correlation with near-infrared flux, color or morphology. This lack of correlation indicates there is little connection between the two emission mechanisms and is consistent with the near-infrared emission being dominated by starlight rather than a Seyfert non-stellar continuum. Near-infrared X-ray sources make up roughly half of all extremely red (J-H > 1.4) objects brighter than H > 24.5. These red X-ray sources have a range of hardness ratios similar to the rest of the sample, decreasing the likelihood of dust-obscured AGN activity as the sole explanation for their red color. ...

  19. Air core Bragg fibers for delivery of near-infrared laser radiation

    Science.gov (United States)

    Jelínek, Michal; Frank, Milan; Kubeček, Václav; Matějec, Vlastimil; Kašík, Ivan; Podrazký, Ondřej

    2014-12-01

    Optical fibers designed for high power laser radiation delivery represent important tools in medicine, solar systems, or industry. For such purposes several different types of glass optical fibers such as silica, sapphire, or chalcogenide ones as well as hollow-glass fibers, photonic crystal fibers and Bragg fibers have been investigated. Air-core Bragg fibers or photonic crystal fibers offer us the possibility of light transmission in a low dispersive material - air having a high damage threshold and small non-linear coefficient. However, preforms for drawing Bragg fibers can be fabricated by MCVD method similarly as preforms of standard silica fibers. In this paper we present fundamental characteristics of laboratory-designed and fabricated Bragg fibers with air cores intended for delivery of laser radiation at a wavelength range from 0.9 to 1.5 μm. Bragg fibers with different air core diameters of 5, 45 and 73 mm were prepared. The fiber core was surrounded by three pairs of circular Bragg layers. Each pair was composed of one layer with a high and one layer with a low refractive index with a contrast up to 0.03. Several laser sources emitting at 0.975, 1.06, and 1.55 μm were used as radiation sources. Attenuation coefficients, overall transmissions, bending losses, and spatial profiles of output beams from fibers were determined at these wavelengths. The lowest attenuation coefficient of 70 dB/km was determined for the 45 μm and 73 mm air-core fiber when radiation from a laser was launched into the fibers by using optical lenses. However, multimodal transmission has been observed in such condition. It has also been found that bending losses of such fibers are negligible for bending diameters higher than 15 mm.

  20. Near-Infrared Polarization Source Catalog of the Northeastern Regions of the Large Magellanic Cloud

    CERN Document Server

    Kim, Jaeyeong; Pak, Soojong; Park, Won-Kee; Tamura, Motohide

    2015-01-01

    We present a near-infrared band-merged photometric and polarimetric catalog for the 39$\\arcmin$ $\\times$ 69$\\arcmin$ fields on the northeastern part of the Large Magellanic Cloud (LMC), which were observed using SIRPOL, an imaging polarimeter of the InfraRed Survey Facility (IRSF). This catalog lists 1,858 sources brighter than 14 mag at $H$ band with polarization signal-to-noise ratio greater than three in the $J$, $H$, or $K_s$ bands. Based on the relationship between the extinction and the polarization degree, we argue that the polarization mostly arises from dichroic extinctions caused by local interstellar dust in the LMC. This catalog allows us to map polarization structures to examine the global geometry of the local magnetic field, and to show a statistical analysis of polarization of each field to understand its polarization properties. At the selected fields with coherent polarization position angles, we estimate magnetic field strengths in the range of 3$-$25 $\\mu$G using the Chandrasekhar-Fermi me...

  1. NEAR-INFRARED POLARIZATION SOURCE CATALOG OF THE NORTHEASTERN REGIONS OF THE LARGE MAGELLANIC CLOUD

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaeyeong; Pak, Soojong [School of Space Research, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin, Gyeonggi-do 446-701 (Korea, Republic of); Jeong, Woong-Seob; Park, Won-Kee [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Tamura, Motohide, E-mail: jaeyeong@khu.ac.kr, E-mail: jeongws@kasi.re.kr [The University of Tokyo/National Astronomical Observatory of Japan/Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2016-01-15

    We present a near-infrared band-merged photometric and polarimetric catalog for the 39′ × 69′ fields in the northeastern part of the Large Magellanic Cloud (LMC), which were observed using SIRPOL, an imaging polarimeter of the InfraRed Survey Facility. This catalog lists 1858 sources brighter than 14 mag in the H band with a polarization signal-to-noise ratio greater than three in the J, H, or K{sub s} bands. Based on the relationship between the extinction and the polarization degree, we argue that the polarization mostly arises from dichroic extinctions caused by local interstellar dust in the LMC. This catalog allows us to map polarization structures to examine the global geometry of the local magnetic field, and to show a statistical analysis of the polarization of each field to understand its polarization properties. In the selected fields with coherent polarization position angles, we estimate magnetic field strengths in the range of 3−25 μG using the Chandrasekhar–Fermi method. This implies the presence of large-scale magnetic fields on a scale of around 100 parsecs. When comparing mid- and far-infrared dust emission maps, we confirmed that the polarization patterns are well aligned with molecular clouds around the star-forming regions.

  2. Near infrared electroluminescence of ZnMgO/InN core-shell nanorod heterostructures grown on Si substrate.

    Science.gov (United States)

    Wu, Guoguang; Zheng, Weitao; Gao, Fubin; Yang, Hang; Zhao, Yang; Yin, Jingzhi; Zheng, Wei; Li, Wancheng; Zhang, Baolin; Du, Guotong

    2016-07-27

    This paper presents a systematic investigation of a ZnMgO/InN core-shell nanorods heterojunction device on a p-Si substrate. Here we demonstrated the heteroepitaxial growth of the well-aligned ZnMgO/InN core-shell nanorods structure, which enabled an increased heterojunction area to improve the carrier injection efficiency of nanodevices by plasma-assisted molecular beam epitaxy combined with metal-organic chemical vapor deposition. In situ X-ray photoelectron spectroscopy measurements were performed on the ZnMgO nanorods, the interface of ZnMgO/InN and the InN core-shell nanorods to fully understand the structure and working mechanism of the heterojunction device. The current transport mechanism has been discussed in terms of the characteristics of current-voltage and the energy band diagram of the n-InN/ZnMgO/p-Si heterojunction. At a low forward voltage, the current transport followed the dependence of I ∼ V(1.47), which was attributed to the deep-level assisted tunneling. When the forward voltage was larger than 10 V, the current followed the relation of I ∼ V(2) because of the radiative recombination process. In accordance with the above conclusion, the near-infrared electroluminescence of the diode could be observed after the forward bias voltage up to 11.6 V at room temperature. In addition, the size quantization effect and the intrinsic electron accumulation of the InN core-shell nanorods were investigated to explain the blueshift and broadened bandwidth. Furthermore, the light output power of about 0.6 microwatt at a fixed wavelength of 1500 nm indicated that our study will further provide a useful route for realizing the near-infrared electroluminescence of InN on Si substrate.

  3. Distortion of Magnetic Fields in a Starless Core: Near-infrared Polarimetry of FeSt 1-457

    Science.gov (United States)

    Kandori, Ryo; Tamura, Motohide; Kusakabe, Nobuhiko; Nakajima, Yasushi; Kwon, Jungmi; Nagayama, Takahiro; Nagata, Tetsuya; Tomisaka, Kohji; Tatematsu, Ken'ichi

    2017-08-01

    Magnetic fields are believed to play an important role in controlling the stability and contraction of the dense condensations of gas and dust that lead to the formation of stars and planetary systems. In the present study, the magnetic field of FeSt 1-457, a cold starless molecular cloud core, was mapped on the basis of the polarized near-infrared light from 185 background stars after being dichroically absorbed by dust aligned with the magnetic field in the core. A distinct “hourglass-shaped” magnetic field was identified in the region of the core, and was interpreted as the first evidence of a magnetic field structure distorted by mass condensation in a starless core. The steep curvature of the magnetic field lines obtained in the present study indicates that the distortion was mainly created during the formation phase of the dense core. The derived mass-to-magnetic flux ratio indicates that the core is in a magnetically supercritical state. However, the stability of the core can be considered to be in a nearly critical state if the additional contributions from the thermal and turbulent support are included. Further diffusion of the magnetic field and/or turbulent dissipation would cause the onset of the dynamical collapse of the core. The geometrical relationship between the direction of the magnetic field lines and the elongation of the core was found to be in good agreement with theoretical predictions for the formation of Sun-like stars under the influence of a magnetic field.

  4. A Near-Infrared and Temperature-Responsive Pesticide Release Platform through Core-Shell Polydopamine@PNIPAm Nanocomposites.

    Science.gov (United States)

    Xu, Xiaohui; Bai, Bo; Wang, Honglun; Suo, Yourui

    2017-02-22

    Controlled stimuli-responsive release systems are a feasible and effective way to increase the efficiency of pesticides and help improve environmental pollution issues. However, near-infrared (NIR)-responsive systems for encapsulation of pesticides for controlling release have not been reported because of high cost and load ability of conventional NIR absorbers as well as complicated preparation process. Herein, we proposed polydopamine (PDA) microspheres as a photothermal agent owing to their abundant active sites, satisfactory photothermal efficiency, low cost, and easy fabrication, followed by capping with a PNIPAm thermosensitive polymer shell. In this core-shell PDA@PNIPAm hybrid system, the PDA core provided excellent temperature and NIR-light sensitivity as well as high loading capacity, while the PNIPAm applied as both a thermosensitive gatekeeper and a pesticide reservoir. The structure of the PDA@PNIPAm nanocomposites was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering, and thermogravimetric analysis; the results showed that the nanocomposites had a well-defined core-shell configuration for efficient loading of small pesticide molecules. Moreover, the core-shell PDA@PNIPAm nanocomposites exhibited high loading capacity and temperature- or NIR-controlled release performance. Overall, this system has significant potential in controlled drug release and agriculture-related fields as a delivery system for pesticides with photothermal responsive behavior.

  5. Use of near infrared spectroscopy to distinguish carbonization processes and charcoal sources

    Directory of Open Access Journals (Sweden)

    Thiago Campos Monteiro

    2010-09-01

    Full Text Available The near infrared spectroscopy (NIRS has shown a rapid and accurate technique for evaluation of materials ofbiological origin. The objective of this study was to evaluate the ability of the near infrared (NIR spectroscopy associated to thePrincipal Component Analysis (PCA for the separation of carbonization processes and identification of the origin of the woodsused in the carbonizations. Hence, the charcoal of seven species of Eucalyptus and twenty native species from the Cerrado(savannah of Minas Gerais, Brazil were investigated. The Eucalyptus wood was carbonized in a laboratory furnace and in a 190m3 industrial rectangular kilns while the wood of native vegetation was carbonized only under laboratory conditions. The sampleswere grinded for NIR spectra acquirement. The NIR spectra were analyzed by PCA but no cluster were identified allowingdiscrimination between charcoal produced from native and from Eucalyptus wood. However, the cluster formed in the PCA whenusing the first derivative NIR spectra permitted to distinguish charcoal produced in different processes of carbonization. Twogroups of data for charcoal produced in the industrial rectangular kilns were also observed, suggesting heterogeneity in thecarbonization process.

  6. Green synthesis of near infrared core/shell quantum dots for photocatalytic hydrogen production

    Science.gov (United States)

    Zhao, Haiguang; Jin, Lei; Zhou, Yufeng; Bandar, AlOtaibi; Fan, Zhiyuan; Govorov, Alexander O.; Mi, Zetian; Sun, Shuhui; Rosei, Federico; Vomiero, Alberto

    2016-12-01

    Quantum dots (QDs) are attractive systems for potential applications in future solar energy technologies, due to their optical properties which are tunable as a function of size and composition. In this study, we synthesized PbS QDs with first excitonic peak in the range 1060 to 1300 nm using a PbCl2/sulfur molar ratio of 10:1. The first excitonic absorption peak from 1300 to 950 nm of the PbS/CdS core/shell QDs can be further synthesized via the cation exchange approach. Our method resulted in high quantum yield, good stability, monodisperse QD solutions with a full surface coverage by excess Cd cations. In addition, we used our core/shell QDs in a photoelectrochemical cell for hydrogen generation. This heterostructure exhibited a saturated photocurrent as high as 3.3 mA cm-2, leading to ˜29 ml cm-2 d-1 hydrogen generation, indicating the strong potential of our core/shell QDs for applications in water splitting.

  7. Highly efficient near-infrared light-emitting diodes by using type-II CdTe/CdSe core/shell quantum dots as a phosphor.

    Science.gov (United States)

    Shen, Huaibin; Zheng, Ying; Wang, Hongzhe; Xu, Weiwei; Qian, Lei; Yang, Yixing; Titov, Alexandre; Hyvonen, Jake; Li, Lin Song

    2013-11-29

    In this paper, we present an innovative method for the synthesis of CdTe/CdSe type-II core/shell structure quantum dots (QDs) using 'greener' chemicals. The PL of CdTe/CdSe type-II core/shell structure QDs ranges from 600 to 820 nm, and the as-synthesized core/shell structures show narrow size distributions and stable and high quantum yields (50–75%). Highly efficient near-infrared light-emitting diodes (LEDs) have been demonstrated by employing the CdTe/CdSe type-II core/shell QDs as emitters. The devices fabricated based on these type-II core/shell QDs show color-saturated near-infrared emission from the QD layers, a low turn-on voltage of 1.55 V, an external quantum efficiency (EQE) of 1.59%, and a current density and maximum radiant emittance of 2.1 × 10(3) mA cm−2 and 17.7 mW cm−2 at 8 V; it is the first report to use type-II core/shell QDs as near-infrared emitters and these results may offer a practicable platform for the realization of near-infrared QD-based light-emitting diodes, night-vision-readable displays, and friend/foe identification system.

  8. Core/Shell NaGdF4:Nd3+/NaGdF4 Nanocrystals with Efficient Near-Infrared to Near-Infrared Downconversion Photoluminescence for Bioimaging Applications

    Science.gov (United States)

    Chen, Guanying; Ohulchanskyy, Tymish Y.; Liu, Sha; Law, Wing-Cheung; Wu, Fang; Swihart, Mark T.; Ågren, Hans; Prasad, Paras N.

    2012-01-01

    We have synthesized core/shell NaGdF4:Nd3+/NaGdF4 nanocrystals with an average size of 15 nm and exceptionally high photoluminescence (PL) quantum yield. When excited at 740 nm, the nanocrystals manifest spectrally distinguished, near infrared to near infrared (NIR-to-NIR) downconversion PL peaked at ~900, ~1050, and ~1300 nm. The absolute quantum yield of NIR-to-NIR PL reached 40% for core-shell nanoparticles dispersed in hexane. Time-resolved PL measurements revealed that this high quantum yield was achieved through suppression of nonradiative recombination originating from surface states and cross relaxations between dopants. NaGdF4:Nd3+/NaGdF4 nanocrystals, synthesized in organic media, were further converted to be water-dispersible by eliminating the capping ligand of oleic acid. NIR-to-NIR PL bioimaging was demonstrated both in vitro and in vivo through visualization of the NIR-to-NIR PL at ~900 nm under incoherent lamp light excitation. The fact that both excitation and the PL of these nanocrystals are in the biological window of optical transparency, combined with their high quantum efficiency, spectral sharpness and photostability, makes these nanocrystals extremely promising as optical biomaging probes. PMID:22401578

  9. Near-Infrared Imaging Polarimetry of M42: Aperture Polarimetry of Point-like Sources

    CERN Document Server

    Kusakabe, Nobuhiko; Kandori, Ryo; Hashimoto, Jun; Nakajima, Yasushi; Nagata, Tetsuya; Nagayama, Takahiro; Hough, Jim; Lucas, Phil

    2008-01-01

    We have conducted aperture polarimetry of ~500 stars of the Orion Nebula Cluster (ONC) in M42 based on our wide-field (~8'\\times 8') $JHKs$ band polarimetry. Most of the near-infrared (NIR) polarizations are dichroic, with position angles of polarization agreeing, both globally and locally, with previous far-infrared (FIR) and submillimeter observations, having taken into account the 90$^\\circ $ difference in angles between dichroic absorption and emission. This is consistent with the idea that both NIR dichroic polarizations and FIR/submillimeter thermal polarizations trace the magnetic fields in the OMC-1 region. The magnetic fields inferred from these observations show a pinch at scales less than 0.5 pc with a centroid near IRc2. The hourglass-shaped magnetic field pattern is explained by the models in which the magnetic field lines are dragged along with the contracting gas and then wound up by rotation in a disk. The highly polarized region to the northwest of IRc2 and the low-polarized region near the b...

  10. Magnetic nanohybrids loaded with bimetal core-shell-shell nanorods for bacteria capture, separation, and near-infrared photothermal treatment.

    Science.gov (United States)

    Hu, Bo; Wang, Ning; Han, Lu; Chen, Ming-Li; Wang, Jian-Hua

    2015-04-20

    A novel antimicrobial nanohybrid based on near-infrared (NIR) photothermal conversion is designed for bacteria capture, separation, and sterilization (killing). Positively charged magnetic reduced graphene oxide with modification by polyethylenimine (rGO-Fe3 O4 -PEI) is prepared and then loaded with core-shell-shell Au-Ag-Au nanorods to construct the nanohybrid rGO-Fe3 O4 -Au-Ag-Au. NIR laser irradiation melts the outer Au shell and exposes the inner Ag shell, which facilitates controlled release of the silver shell. The nanohybrids combine physical photothermal sterilization as a result of the outer Au shell with the antibacterial effect of the inner Ag shell. In addition, the nanohybrid exhibits high heat conductivity because of the rGO and rapid magnetic-separation capability that is attributable to Fe3 O4 . The nanohybrid provides a significant improvement of bactericidal efficiency with respect to bare Au-Ag-Au nanorods and facilitates the isolation of bacteria from sample matrixes. A concentration of 25 μg mL(-1) of nanohybrid causes 100 % capture and separation of Escherichia coli O157:H7 (1×10(8) cfu mL(-1) ) from an aqueous medium in 10 min. In addition, it causes a 22 °C temperature rise for the surrounding solution under NIR irradiation (785 nm, 50 mW cm(-2) ) for 10 min. With magnetic separation, 30 μg mL(-1) of nanohybrid results in a 100 % killing rate for E. coli O157:H7 cells. The facile bacteria separation and photothermal sterilization is potentially feasible for environmental and/or clinical treatment.

  11. XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources

    CERN Document Server

    Haakonsen, Christian Bernt; 10.1088/0067-0049/184/1/138

    2009-01-01

    The 18806 ROSAT All Sky Survey Bright Source Catalog (RASS/BSC) X-ray sources are quantitatively cross-associated with near-infrared (NIR) sources from the Two Micron All Sky Survey Point Source Catalog (2MASS/PSC). An association catalog is presented, listing the most likely counterpart for each RASS/BSC source, the probability Pid that the NIR source and X-ray source are uniquely associated, and the probability Pnoid that none of the 2MASS/PSC sources are associated with the X-ray source. The catalog includes 3853 high quality (Pid>0.98) X-ray--NIR matches, 2280 medium quality (0.98>Pid>0.9) matches, and 4153 low quality (0.9>Pid>0.5) matches. Of the high quality matches, 1418 are associations that are not listed in the SIMBAD database, and for which no high quality match with a USNO-A2 optical source was presented for the RASS/BSC source in previous work. The present work offers a significant number of new associations with RASS/BSC objects that will require optical/NIR spectroscopy for classification. For...

  12. Near-infrared counterparts of Chandra X-ray sources toward the Galactic Center

    CERN Document Server

    DeWitt, Curtis; Eikenberry, Stephen S; Blum, Robert; Olsen, Knut; Sellgren, Kris; Sarajedini, Ata

    2010-01-01

    The Chandra X-ray Observatory has now discovered nearly 10,000 X-ray point sources in the 2 x 0.8 degree region around the Galactic Center (Muno 2009). The sources are likely to be a population of accreting binaries in the Galactic Center, but little else is known of their nature. We obtained JHKs imaging of the 17'x 17' region around Sgr A*, an area containing 4339 of these X-ray sources, with the ISPI camera on the CTIO 4-m telescope. We cross-correlate the Chandra and ISPI catalogs to find potential IR counterparts to the X-ray sources. The extreme IR source crowding in the field means that it is not possible to establish the authenticity of the matches with astrometry and photometry alone. We find 2137 IR/X-ray astrometrically matched sources: statistically we estimate that our catalog contains 289 +/- 13 true matches to soft X-ray sources and 154 +/- 39 matches to hard X-ray sources. However, the fraction of true counterparts to candidate counterparts for hard sources is just 11 %, compared to 60 % for s...

  13. Near-Infrared Spectroscopy of Faint Discrete X-ray Point Sources Constituting the Galactic Ridge X-ray Emission

    CERN Document Server

    Morihana, Kumiko; Dubath, Pierre; Yoshida, Tessei; Suzuki, Kensuke; Ebisawa, Ken

    2016-01-01

    The Galactic Ridge X-ray Emission (GRXE) is apparently extended X-ray emission along the Galactic Plane. The X-ray spectrum is characterized by hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (~80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations, thus GRXE is mostly composed of dim Galactic X-ray point sources at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out Near-Infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l,b)=(0.1{\\arcdeg}, -1.4{\\arcdeg}) and (28.5{\\arcdeg}, 0.0{\\arcdeg}) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as HI(Br{\\gamma}), HeI, and HeII (2 objects), (B)...

  14. Dual-modal photoacoustic and optical coherence tomography using a single near-infrared supercontinuum laser source

    Science.gov (United States)

    Lee, Changho; Han, Seunghoon; Kim, Sehui; Jeon, Minyoung; Jeon, Mansik; Kim, Chulhong; Kim, Jeehyun

    2013-03-01

    We report the development of a combined dual-modal photoacoustic and optical coherence tomography (PA-OCT) system using a single near-infrared (NIR) supercontinuum laser source which can provide both optical absorption and scattering contrasts simultaneously. By using a small sized pulsed Nd:YAG microchip laser and a photonic crystal fiber, we fabricated a pulsed broadband supercontinuum source from 600 to 1700 nm. Under the same optical hardware system, intrinsically registered PA and OCT images are acquired in a single scanning. In order to demonstrate feasibility of our system, we successfully acquired the PA and OCT images of black and white hairs images at the same time. The black hair was detected in both PA and OCT images, while the white hair appeared only in the OCT image. This result suggests the potential of compact, cost-effective, and simple dual-modal PA-OCT system. Moreover, we believe that this approach will be a key point for commercialization and clinical translation.

  15. Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs

    CERN Document Server

    Halverson, Samuel; Ramsey, Lawrence; Hearty, Fred; Wilson, John; Holtzman, Jon; Redman, Stephen; Nave, Gillian; Nidever, David; Nelson, Matt; Venditti, Nick; Bizyaev, Dmitry; Fleming, Scott

    2014-01-01

    We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astro-photonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units that can yield a stable and repeatable output spectrum. An FFP is a unique alternative to a traditional etalon, as the interferometric cavity is made of single-mode fiber rather than an air-gap spacer. This design allows for excellent collimation, high spectral finesse, rigid mechanical stability, insensitivity to vibrations, and no need for vacuum operation. The device we have tested is a commercially available product from Micron Optics. Our development path is targeted towards a calibration source for the Habitable-Zone Planet Finder (HPF), a near-infrared spectrograph designed to detect terrestrial-mass planets around low-mass stars, but this reference could also be used in many existing and planned fiber-fed spectrographs as we illustrate using the Apache Point Observato...

  16. Towards a wireless open source instrument:functional Near-Infrared Spectroscopy in mobile neuroergonomics and BCI applications

    Directory of Open Access Journals (Sweden)

    Alexander eVon Lühmann

    2015-11-01

    Full Text Available Brain-Computer Interfaces (BCIs and neuroergonomics research have high requirements regarding robustness and mobility. Additionally, fast applicability and customization are desired. Functional Near-Infrared Spectroscopy (fNIRS is an increasingly established technology with a potential to satisfy these conditions. EEG acquisition technology, currently one of the main modalities used for mobile brain activity assessment, is widely spread and open for access and thus easily customizable. fNIRS technology on the other hand has either to be bought as a predefined commercial solution or developed from scratch using published literature. To help reducing time and effort of future custom designs for research purposes, we present our approach towards an open source multichannel stand-alone fNIRS instrument for mobile NIRS-based neuroimaging, neuroergonomics and BCI/BMI applications. The instrument is low-cost, miniaturized, wireless and modular and openly documented on www.opennirs.org. It provides features such as scalable channel number, configurable regulated light intensities, programmable gain and lock-in amplification.In this paper, the system concept, hardware, software and mechanical implementation of the lightweight stand-alone instrument are presented and the evaluation and verification results of the instrument's hardware and physiological fNIRS functionality are described. Its capability to measure brain activity is demonstrated by qualitative signal assessments and a quantitative mental arithmetic based BCI study with 12 subjects.

  17. Synthesis and Near-infrared Luminescent Properties of NaGdF4:Nd3+@NaGdF4 Core/Shell Nanocrystals with Different Shell Thickness.

    Science.gov (United States)

    Li, Xinke; You, Fangtian; Peng, Hongshang; Huang, Shihua

    2016-04-01

    The near-infrared to near-infrared (NIR-to-NIR) photoluminescence of nanocrystals has outstanding advantages in biological imaging. NaGdF4:Nd3+ core nanocrystals and NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with different shell thicknesses were synthesized by a simple solvothermal method. The obtained nanocrystals were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The phase of all nanocrystals is hexagonal. NaGdF4:Nd3+ core nanocrystals have an average size of 6 nm. By controlling core-shell ratio for 1:2 and 1:3, we obtained NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with average sizes of 10 nm and 11 nm, respectively. When excited at 808 nm, strong NIR emission was observed. The emission peaks at -860 nm, -1060 nm and -1330 nm correspond to the transitions from the 4F3/2 state to the 4I9/2, 4I1/2 and 4I13/2 state of Nd3+ ions, respectively. The emission intensity of NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals is stronger than that of the core. The intensity increases with the increase of shell thickness. The shell improves the luminous efficiency by reducing surface defects. The decay time of Nd3+ emission in NaGdF4:Nd3+@NaGdF4 core/shell nanocrystal is longer than that in NaGdF4:Nd3+ core, indicating that the shell isolates effectively the emitting ions (Nd3+) from the quenching defects. With the increase of shell thickness, the decay time becomes longer. Within a certain range of shell thickness, thicker shell can protect the emitting Nd3+ ions on the surface of core nanocrystals more effectively.

  18. InAs/InP/ZnSe Core/Shell/Shell Quantum Dots as Near-Infrared Emitters: Bright, Narrow-Band, Non-Cadmium Containing, and Biocompatible

    Science.gov (United States)

    Xie, Renguo; Chen, Kai; Chen, Xiaoyuan; Peng, Xiaogang

    2010-01-01

    High quality InAs/InP/ZnSe core/shell/shell quantum dots have been grown by a one-pot approach. This engineered quantum dots with unique near-infrared (NIR) fluorescence, possessing outstanding optical properties, and the biocompatibility desired for in vivo applications. The resulting quantum dots have significantly lower intrinsic toxicity compared to NIR emissive dots containing elements such as cadmium, mercury, or lead. Also, these newly developed ultrasmall non-Cd containing and NIR-emitting quantum dots showed significantly improved circulation half-life and minimal reticuloendothelial system (RES) uptake. PMID:20631914

  19. Iron/iron oxide core/shell nanoparticles for magnetic targeting MRI and near-infrared photothermal therapy.

    Science.gov (United States)

    Zhou, Zhiguo; Sun, Yanan; Shen, Jinchao; Wei, Jie; Yu, Chao; Kong, Bin; Liu, Wei; Yang, Hong; Yang, Shiping; Wang, Wei

    2014-08-01

    The development of photothermal agents (PTAs) with good stability, low toxicity, highly targeting ability and photothermal conversion efficiency is an essential pre-requisite to near-infrared photothermal therapy (PTT) in vivo. Herein, we report the readily available PEGylated Fe@Fe3O4 NPs, which possess triple functional properties in one entity - targeting, PTT, and imaging. Compared to Au nanorods, they exhibit comparable photothermal conversion efficiency (∼20%), and much higher photothermal stability. They also show a high magnetization value and transverse relaxivity (∼156 mm(-1) s(-1)), which should be applied for magnetic targeting MRI. With the Nd-Fe-B magnet (0.5 T) beside the tumour for 12 h on the xenograft HeLa tumour model, PEGylated Fe@Fe3O4 NPs exhibit an obvious accumulation. In tumour, the intensity of MRI signal is ∼ three folds and the increased temperature is ∼ two times than those without magnetic targeting, indicating the good magnetic targeting ability. Notably, the intrinsic high photothermal conversion efficiency and selective magnetic targeting effect of the NPs in tumour play synergistically in highly efficient ablation of cancer cells in vitro and in vivo.

  20. Investigation on Guided-Mode Characteristics of Hollow-Core Photonic Crystal Fibre at Near-Infrared Wavelengths

    Institute of Scientific and Technical Information of China (English)

    YUAN Jin-Hui; YU Chong-Xiu; SANG Xin-Zhu; LI Wen-Jing; ZHOU Gui-Yao; LI Shu-Guang; HOU Lan-Tian

    2009-01-01

    Guided-mode characteristics of hollow-core photonic crystal fibre (HC-PCF) are experimentally and theoretically investigated.The transmission spectrum in the range from 755 to 845 nm is observed and the loss is measured to be 0.12dB/m at 80Onto by cut-back method.Based on the full-vector beam propagation method and the full-vector plane-wave method,the characteristics of mode field over propagation distance I m are simulated,and the results show that the propagation efficiency can be above 80%.Compared with the fundamental guided mode well confined in air core within shorter propagation distance,the second-order guided mode leaks into the cladding region and graduafiy attenuates due to larger refractive index difference.The primary loss factors in HC-PCF and the corresponding solutions are elementarily discussed.

  1. Multistate Redox Switching and Near-Infrared Electrochromism Based on a Star-Shaped Triruthenium Complex with a Triarylamine Core

    Science.gov (United States)

    Tang, Jian-Hong; He, Yan-Qin; Shao, Jiang-Yang; Gong, Zhong-Liang; Zhong, Yu-Wu

    2016-01-01

    A star-shaped cyclometalated triruthenium complex 2(PF6)n (n = 3 and 4) with a triarylamine core was synthesized, which functions as a molecular switch with five well-separated redox states in both solution and film states. The single-crystal X-ray structure of 2(PF6)3 is presented. This complex displays four consecutive one-electron redox waves at +0.082, +0.31, +0.74, and +1.07 V vs Ag/AgCl. In each redox state, it shows significantly different NIR absorptions with λmax of 1590 nm for 24+, 1400 nm for 25+, 1060 nm for 26+, and 740 nm for 27+, respectively. Complex 24+ shows a single-line EPR signal at g = 2.060, while other redox states are all EPR inactive. The spin density distributions and NIR absorptions in different redox states were rationalized by DFT and TDDFT calculations. A vinyl-substituted triruthenium analogous 3(PF6)4 was prepared, which was successfully polymerized on ITO glass electrode surfaces by reductive electropolymerization. The obtained poly-3n+/ITO film was characterized by FTIR, AFM, and SEM analysis. It shows four well-defined redox couples and reversible multistate NIR electrochromism. In particular, a contrast ratio (ΔT%) up to 63% was achieved at the optic telecommunication wavelength (1550 nm). PMID:27731404

  2. Near Infrared Spectroscopy

    Science.gov (United States)

    2009-01-01

    directly, but to evaluate the performance of each of these systems in their recommended (UMMS) and mar- keted (HT) configurations. Although we did not...son Technology (HT) oximeter is mar- keted specifically for use on the thenar muscle. We therefore used the thenar site for the HT sensor because...critical fourth fac- tor which differentiates near-infrared spectroscopic tissue monitors—the de- sign of the spectroscopic system . There are multiple

  3. Design and synthesis of highly luminescent near-infrared-emitting water-soluble CdTe/CdSe/ZnS core/shell/shell quantum dots.

    Science.gov (United States)

    Zhang, Wenjin; Chen, Guanjiao; Wang, Jian; Ye, Bang-Ce; Zhong, Xinhua

    2009-10-19

    Applications of water-dispersible near-infrared (NIR)-emitting quantum dots (QDs) have been hampered by their instability and low photoluminescence (PL) efficiencies. In this paper, water-soluble highly luminescent NIR-emitting QDs were developed through constructing CdTe/CdSe/ZnS core/shell/shell nanostructure. The CdTe/CdSe type-II structure yields the QDs with NIR emission. By varying the size of CdTe cores and the thickness of the CdSe shell, the emission wavelength of the obtained nanostructure can span from 540 to 825 nm. In addition, the passivation of the ZnS shell with a substantially wide bandgap confines the excitons within the CdTe/CdSe interface and isolates them from the solution environment and consequently improves the stability of the nanostructure, especially in aqueous media. An effective shell-coating route was developed for the preparation of CdTe/CdSe core/shell nanostructures by selecting capping reagents with a strong coordinating capacity and adopting a low temperature for shell deposition. An additional ZnS shell was deposited around the outer layer of CdTe/CdSe QDs to form the core/shell/shell nanostructure through the decomposition of single molecular precursor zinc diethyldithiocarbamate in the crude CdTe/CdSe reaction solution. The water solubilization of the initially oil-soluble CdTe/CdSe/ZnS QDs was achieved through ligand replacement by 3-mercaptopropionic acid. The as-prepared water-soluble CdTe/CdSe/ZnS QDs possess PL quantum yields as high as 84% in aqueous media, which is one of the best results for the luminescent semiconductor nanocrystals.

  4. 近红外技术在岩心含水检测中的应用%APPLICATION OF NEAR INFRARED TECHNIQUE IN CORE WATER CONTENT DETECTION

    Institute of Scientific and Technical Information of China (English)

    郭伟

    2011-01-01

    岩心含水识别一直是困扰录井解释的难题,随着精细勘探对资料的高质量需求,开展岩心含水检测技术研究成为录井技术发展的必然趋势.将近红外技术引入到岩心含水检测中,研制成功了可以直接在录井现场使用的近红外岩心含水检测仪.经过大量的室内研究实验和现场实际应用,确定了仪器的标定方法和工作流程.在大庆油田8口试油井的13个层中,检测结果与试油结论符合的有12个层,符合率92.3%,见到了很好的效果.%The identification of those water-content cores is always being the problem in the mud logging interpretation. With the requirements of high-quality data in fine exploration, the researches on the identifying techniques of water-content cores have become the inexorable trend for mud logging techniques. Through the introduction of near infrared water-content core identifying technique, the corresponding instrument is developed and directly applied in the field identification. With the help of a large number of laboratory studies & tests and field application, the calibrating method and work flow have been determined. The much better results have been achieved: the coincidence rate is up to 92. 3% I. E. The oil tested results in 12 layers is the same with those of the detection among 13 layers in 8 oil tested wells in Daqing Oilfield.

  5. GUI-based Processing of Near Infrared Imaging

    Science.gov (United States)

    Lambert, Dustin; Crews, L. J.; Huard, T. L.; Gutermuth, R. A.

    2007-05-01

    As part of The University of Tennessee at Martin's University Scholars mentored research program, we have developed GUI-based, interactive software to aid in the processing of ground-based, near-infrared images. The software is coded in Perl and Tcl/Tk to maximize cross-platform compatibility. The software reduces the raw images to a final set of flat-fielded, sky-subtracted images, which are then input into PhotVis (Gutermuth et al. 2004) to extract the positions and photometric magnitudes of the sources. The final result is a band-merged catalog of sources ready for scientific analysis. Using near-infrared observations of molecular cloud cores obtained with the Magellan 6.5-meter Baade telescope at Las Campanas Observatory, we demonstrate the capability of this software.

  6. Theoretical prediction of the source-detector separation distance suited to the application of the spatially resolved spectroscopy from the near-infrared attenuation data cube of tissues

    CERN Document Server

    Ri, Yong-Wu; Im, Song-Jin

    2014-01-01

    The modified Beer-Lambert law (MBL) and the spatially resolved spectroscopy are used to measure the tissue oxidation in muscles and brains by the continuous wave near-infrared spectroscopy. The spatially resolved spectroscopy predicts the change in the concentration of the absorber by measuring the slope of attenuation data according to the separation and calculating the absorption coefficients of tissue on the basis of the slop in attenuation at the separation distance satisfying the linearity of this slop. This study analyzed the appropriate source-detector separation distance by using the diffuse approximation resolution for photon migration when predicting the absorption coefficient by the spatially resolved spectroscopy on the basis of the reflective image of the tissue. We imagine the 3 dimensional attenuation image with the absorption coefficient, reduced scattering coefficient and separation distance as its axes and obtained the attenuation data cube by calculating the attenuation on a certain interva...

  7. Near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Virendra Jain

    2015-01-01

    Full Text Available Tissue ischaemia can be a significant contributor to increased morbidity and mortality. Conventional oxygenation monitoring modalities measure systemic oxygenation, but regional tissue oxygenation is not monitored. Near-infrared spectroscopy (NIRS is a non-invasive monitor for measuring regional oxygen saturation which provides real-time information. There has been increased interest in the clinical application of NIRS following numerous studies that show improved outcome in various clinical situations especially cardiac surgery. Its use has shown improved neurological outcome and decreased postoperative stay in cardiac surgery. Its usefulness has been investigated in various high risk surgeries such as carotid endarterectomy, thoracic surgeries, paediatric population and has shown promising results. There is however, limited data supporting its role in neurosurgical population. We strongly feel, it might play a key role in future. It has significant advantages over other neuromonitoring modalities, but more technological advances are needed before it can be used more widely into clinical practice.

  8. The HELLAS2XMM survey. V. Near-Infrared observations of X-ray sources with extreme X/O ratios

    CERN Document Server

    Mignoli, M; Comastri, A; Brusa, M; Ciliegi, P; Cocchia, F; Fiore, F; La Franca, F; Maiolino, R; Matt, G; Molendi, S; Perola, G C; Puccetti, S; Severgnini, P; Vignali, C

    2004-01-01

    We present the results of deep near-infrared observations of 11 hard X-ray selected sources in the Hellas2XMM survey, with faint optical magnitude (R>24) and high X-ray-to-optical flux ratio. All but one of the sources have been detected in the Ks band, with bright counterparts (Ks5), therefore belonging to the ERO population. A detailed analysis of the surface brightness profiles permits us to classify all of the NIR counterparts. There are 2 point-like objects, 7 elliptical galaxies and one source with a disky profile. None of the extended sources shows any evidence for the presence of a central unresolved object tracing the putative X-ray emitting AGN. Using both the R-K colors and the morphological information, we have estimated for all the sources a ``minimum photometric redshift'', ranging between 0.8 and 2.4; the elliptical hosts have zmin=0.9-1.4. We computed the X-ray properties using these redshifts: most of the sources have NH>10^{22}, with unabsorbed X-ray luminosities up to 10^{45}erg s^{-1}. The...

  9. Near infrared lasers in flow cytometry.

    Science.gov (United States)

    Telford, William G

    2015-07-01

    Technology development in flow cytometry has closely tracked laser technology, the light source that flow cytometers almost exclusively use to excite fluorescent probes. The original flow cytometers from the 1970s and 1980s used large water-cooled lasers to produce only one or two laser lines at a time. Modern cytometers can take advantage of the revolution in solid state laser technology to use almost any laser wavelength ranging from the ultraviolet to the near infrared. Commercial cytometers can now be equipped with many small solid state lasers, providing almost any wavelength needed for cellular analysis. Flow cytometers are now equipped to analyze 20 or more fluorescent probes simultaneously, requiring multiple laser wavelengths. Instrument developers are now trying to increase this number by designing fluorescent probes that can be excited by laser wavelength at the "edges" of the visible light range, in the near ultraviolet and near-infrared region. A variety of fluorescent probes have been developed that excite with violet and long wavelength ultraviolet light; however, the near-infrared range (660-800 nm) has yet seen only exploitation in flow cytometry. Fortunately, near-infrared laser diodes and other solid state laser technologies appropriate for flow cytometry have been in existence for some time, and can be readily incorporated into flow cytometers to accelerate fluorescent probe development. The near infrared region represents one of the last "frontiers" to maximize the number of fluorescent probes that can be analyzed by flow cytometry. In addition, near infrared fluorescent probes used in biomedical tracking and imaging could also be employed for flow cytometry with the correct laser wavelengths. This review describes the available technology, including lasers, fluorescent probes and detector technology optimal for near infrared signal detection. Published by Elsevier Inc.

  10. Near Infrared Counterpart of 2E 1613.5-5053, the Central Source in Supernova Remnant RCW 103

    CERN Document Server

    Tendulkar, Shriharsh P; Archibald, Robert F; Scholz, Paul

    2016-01-01

    On 2016 June 22, 2E 1613.5-5053, the puzzling central compact object in supernova remnant RCW 103, emitted a magnetar-like burst. Using Director's Discretionary Time, we observed 2E 1613.5-5053 with the Hubble Space Telescope (WFC3/IR) and we report here on the detection of a previously unseen infrared counterpart. In observations taken on 2016 July 4 and August 11, we detect a new source ($m_\\mathrm{F110W} = 26.3$ AB mag and $m_\\mathrm{F160W} = 24.2$ AB mag) at the Chandra position of 2E 1613.5-5053 which was not detected in HST/NICMOS images from 2002 August 15 and October 8 to a depth of 24.5 AB mag (F110W) and 25.5 AB mag (F160W). We show that these deep IR observations rule out the possibility of an accreting binary but mimic IR emission properties of magnetars and isolated neutron stars. The presence or absence of a low-mass fallback disk cannot be confirmed from our observations.

  11. Performance characteristics of a passively locked cavity-enhanced absorption spectrometer with wideband-tunable multimode near-infrared light source

    Science.gov (United States)

    Someya, Ryuta; Imamura, Takeshi; Okamoto, Tetsushi; Hatano, Hiroshi; Toyoshima, Naoko; Tei, Kazuyoku; Yamaguchi, Shigeru

    2016-03-01

    A trace material detection system was developed on the basis of cavity-enhanced absorption spectroscopy (CEAS) using a fiber-coupled passively locked external cavity diode laser (PLEC-DL) in the near-infrared (NIR) wavelength region. The oscillation range of an antireflection-coated diode laser (AR-DL) coupled into an external cavity could be simply selected with a narrowband bandpass filter (1 nm), resulting in a stable wavelength oscillation in the wideband tunability between 1640 and 1680 nm. The external cavity acts as a trace material sensor that exhibits excellent flexibility because it is free from the DL source and is carefully designed with mirrors having reflectivities of ca. 99.995 and 99.99%. Trace-level detection was successfully demonstrated with the developed sensor having a minimum detectable absorption coefficient of 2.4 × 10-8 cm-1, which corresponds to 0.15 ppm for CH4 concentration without interference from H2O absorption lines under atmospheric pressure.

  12. The Contribution of z < or Approx. 6 Sources to the Spatial Coherence in the Unresolved Cosmic Near-Infrared and X-Ray Backgrounds

    Science.gov (United States)

    Helgason, K.; Cappelluti, N.; Hasinger, G.; Kashlinsky, A.; Ricotti, M.

    2014-01-01

    A spatial clustering signal has been established in Spitzer/IRAC measurements of the unresolved cosmic near-infrared background (CIB) out to large angular scales, approx. 1deg. This CIB signal, while significantly exceeding the contribution from the remaining known galaxies, was further found to be coherent at a highly statistically significant level with the unresolved soft cosmic X-ray background (CXB). This measurement probes the unresolved CXB to very faint source levels using deep near-IR source subtraction.We study contributions from extragalactic populations at low to intermediate redshifts to the measured positive cross-power signal of the CIB fluctuations with the CXB. We model the X-ray emission from active galactic nuclei (AGNs), normal galaxies, and hot gas residing in virialized structures, calculating their CXB contribution including their spatial coherence with all infrared emitting counterparts. We use a halo model framework to calculate the auto and cross-power spectra of the unresolved fluctuations based on the latest constraints of the halo occupation distribution and the biasing of AGNs, galaxies, and diffuse emission. At small angular scales (1), the 4.5microns versus 0.5-2 keV coherence can be explained by shot noise from galaxies and AGNs. However, at large angular scales (approx.10), we find that the net contribution from the modeled populations is only able to account for approx. 3% of the measured CIB×CXB cross-power. The discrepancy suggests that the CIB×CXB signal originates from the same unknown source population producing the CIB clustering signal out to approx. 1deg.

  13. Synthesis of GdAlO3:Mn(4+),Ge(4+)@Au Core-Shell Nanoprobes with Plasmon-Enhanced Near-Infrared Persistent Luminescence for in Vivo Trimodality Bioimaging.

    Science.gov (United States)

    Liu, Jing-Min; Liu, Yao-Yao; Zhang, Dong-Dong; Fang, Guo-Zhen; Wang, Shuo

    2016-11-09

    The rise of multimodal nanoprobes has promoted the development of new methods to explore multiple molecular targets simultaneously or to combine various bioimaging tools in one assay to more clearly delineate localization and expression of biomarkers. Persistent luminescence nanophosphors (PLNPs) have been qualified as a promising contrast agent for in vivo imaging. The easy surface modification and proper nanostructure design strategy would favor the fabrication of PLNP-based multifunctional nanoprobes for biological application. In this paper, we have proposed novel multifunctional core-shell nanomaterials, applying the Mn(4+) and Ge(4+) co-doped gadolinium aluminate (GdAlO3:Mn(4+),Ge(4+)) PLNPs as the near-infrared persistent luminescence emission center and introducing the gold nanoshell coated on the PLNPs to enhance the luminescence efficiency via plasmon resonance. Our developed core-shell nanoprobes have demonstrated the excellent features of ultrabrightness, superlong afterglow, good monodispersity, low toxicity, and excellent biocompatibility. The well-characterized nanoprobes have been utilized for trimodality in vivo imaging, with near-infrared persistent luminescence for optical imaging, Gd element for magnetic resonance imaging, and Au element for computed tomography imaging.

  14. Cu₂-xSe@mSiO₂-PEG core-shell nanoparticles: a low-toxic and efficient difunctional nanoplatform for chemo-photothermal therapy under near infrared light radiation with a safe power density.

    Science.gov (United States)

    Liu, Xijian; Wang, Qian; Li, Chun; Zou, Rujia; Li, Bo; Song, Guosheng; Xu, Kaibing; Zheng, Yun; Hu, Junqing

    2014-04-21

    A low-toxic difunctional nanoplatform integrating both photothermal therapy and chemotherapy for killing cancer cells using Cu₂-xSe@mSiO₂-PEG core-shell nanoparticles is reported. Silica coating and further PEG modification improve the hydrophilicity and biocompatibility of copper selenide nanoparticles. As-prepared Cu₂-xSe@mSiO₂-PEG nanoparticles not only display strong near infrared (NIR) region absorption and good photothermal effect, but also exhibit excellent biocompatibility. The mesoporous silica shell is provided as the carrier for loading the anticancer drug, doxorubicin (DOX). Moreover, the release of DOX from Cu₂-xSe@mSiO₂-PEG core-shell nanoparticles can be triggered by pH and NIR light, resulting in a synergistic effect for killing cancer cells. Importantly, the combination of photothermal therapy and chemotherapy driven by NIR radiation with safe power density significantly improves the therapeutic efficacy, and demonstrates better therapeutic effects for cancer treatment than individual therapy.

  15. Cation exchange synthesis of uniform PbSe/PbS core/shell tetra-pods and their use as near-infrared photodetectors

    Science.gov (United States)

    Mishra, N.; Mukherjee, B.; Xing, G.; Chakrabortty, S.; Guchhait, A.; Lim, J. Y.

    2016-07-01

    In this work we explore the preparation of complex-shaped semiconductor nanostructures composed of different materials via a cationic exchange process in which the cations of the original semiconductor nanostructure are replaced by cations of different metals with preservation of the shape and the anionic framework of the nanocrystals. Utilizing this cation exchange method, we synthesized two new tetrapods for the first time: Cu2-xSe/Cu2-xS and PbSe/PbS, both prepared from CdSe/CdS tetrapods as `templates'. We also fabricated near-infrared (NIR) photodetectors with a very simple architecture comprising a PbSe/PbS tetrapod layer between two Au electrodes on a glass substrate. When illuminated by a NIR laser, these devices are capable of achieving a responsivity of 11.9 A W-1 without the use of ligand-exchange processes, thermal annealing or hybrid device architecture. Transient absorption spectroscopy was carried out on these PbSe/PbS tetrapods, the results of which suggest that the branched morphology contributes in part to device performance. Investigation of the charge dynamics of the PbSe/PbS tetrapods revealed an extremely long-lived exciton recombination lifetime of ~17 ms, which can result in enhanced photoconductive gain. Overall, these heterostructured tetrapods showcase simultaneously the importance of nanoparticle shape, band structure, and surface chemistry in the attainment of NIR photodetection.In this work we explore the preparation of complex-shaped semiconductor nanostructures composed of different materials via a cationic exchange process in which the cations of the original semiconductor nanostructure are replaced by cations of different metals with preservation of the shape and the anionic framework of the nanocrystals. Utilizing this cation exchange method, we synthesized two new tetrapods for the first time: Cu2-xSe/Cu2-xS and PbSe/PbS, both prepared from CdSe/CdS tetrapods as `templates'. We also fabricated near-infrared (NIR) photodetectors

  16. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  17. Deep Near-Infrared Imaging of the rho Oph Cloud Core: Clues to the Origin of the Lowest-Mass Brown Dwarfs

    CERN Document Server

    Marsh, Kenneth A; Kirkpatrick, J Davy; Lowrance, Patrick J; Cutri, Roc M; Velusamy, Thangasamy

    2010-01-01

    A search for young substellar objects in the rho Oph cloud core region has been made using the deep-integration Combined Calibration Scan images of the 2MASS extended mission in J, H and Ks bands, and Spitzer IRAC images at 3.6, 4.5, 5.8 and 8.0 microns. The field of view of the combined observations was 1 deg x 9.3 arcmin, and the 5 sigma limiting magnitude at J was 20.5. Comparison of the observed SEDs with the predictions of the COND and DUSTY models, for an assumed age of 1 Myr, supports the identification of many of the sources with brown dwarfs, and enables the estimation of effective temperature, Teff. The cluster members are then readily distinguishable from background stars by their locations on a plot of flux density versus Teff. The range of estimated Teff extends down to ~ 750 K, suggesting the presence of objects of sub-Jupiter mass. The results also suggest that the mass function for the rho Oph cloud resembles that of the sigma Orionis cluster based on a recent study, with both rising towards l...

  18. Advances in near-infrared measurements

    CERN Document Server

    Patonay, Gabor

    1991-01-01

    Advances in Near-Infrared Measurements, Volume 1 provides an overview of near-infrared spectroscopy. The book is comprised of six chapters that tackle various areas of near-infrared measurement. Chapter 1 discusses remote monitoring techniques in near-infrared spectroscopy with an emphasis on fiber optics. Chapter 2 covers the applications of fibers using Raman techniques, and Chapter 3 tackles the difficulties associated with near-infrared data analysis. The subsequent chapters present examples of the capabilities of near-infrared spectroscopy from various research groups. The text wi

  19. Adapting photosynthesis to the near-infrared: non-covalent binding of phycocyanobilin provides an extreme spectral red-shift to phycobilisome core-membrane linker from Synechococcus sp. PCC7335.

    Science.gov (United States)

    Miao, Dan; Ding, Wen-Long; Zhao, Bao-Qing; Lu, Lu; Xu, Qian-Zhao; Scheer, Hugo; Zhao, Kai-Hong

    2016-06-01

    Phycobiliproteins that bind bilins are organized as light-harvesting complexes, phycobilisomes, in cyanobacteria and red algae. The harvested light energy is funneled to reaction centers via two energy traps, allophycocyanin B and the core-membrane linker, ApcE1 (conventional ApcE). The covalently bound phycocyanobilin (PCB) of ApcE1 absorbs near 660 nm and fluoresces near 675 nm. In cyanobacteria capable of near infrared photoacclimation, such as Synechococcus sp. PCC7335, there exist even further spectrally red shifted components absorbing >700 nm and fluorescing >710 nm. We expressed the chromophore domain of the extra core-membrane linker from Synechococcus sp. PCC7335, ApcE2, in E. coli together with enzymes generating the chromophore, PCB. The resulting chromoproteins, PCB-ApcE2(1-273) and the more truncated PCB-ApcE2(24-245), absorb at 700 nm and fluoresce at 714 nm. The red shift of ~40 nm compared with canonical ApcE1 results from non-covalent binding of the chromophore by which its full conjugation length including the Δ3,3(1) double bond is preserved. The extreme spectral red-shift could not be ascribed to exciton coupling: dimeric PCB-ApcE2(1-273) and monomeric-ApcE2(24-245) absorbed and fluoresced similarly. Chromophorylation of ApcE2 with phycoerythrobilin- or phytochromobilin resulted in similar red shifts (absorption at 615 and 711 nm, fluorescence at 628 or 726 nm, respectively), compared to the covalently bound chromophores. The self-assembled non-covalent chromophorylation demonstrates a novel access to red and near-infrared emitting fluorophores. Brightly fluorescent biomarking was exemplified in E. coli by single-plasmid transformation.

  20. Visible-near infrared point spectrometry of drill core samples from Río Tinto, Spain: results from the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) drilling exercise.

    Science.gov (United States)

    Sutter, Brad; Brown, Adrian J; Stoker, Carol R

    2008-10-01

    Sampling of subsurface rock may be required to detect evidence of past biological activity on Mars. The Mars Astrobiology Research and Technology Experiment (MARTE) utilized the Río Tinto region, Spain, as a Mars analog site to test dry drilling technologies specific to Mars that retrieve subsurface rock for biological analysis. This work examines the usefulness of visible-near infrared (VNIR) (450-1000 nm) point spectrometry to characterize ferric iron minerals in core material retrieved during a simulated Mars drilling mission. VNIR spectrometry can indicate the presence of aqueously precipitated ferric iron minerals and, thus, determine whether biological analysis of retrieved rock is warranted. Core spectra obtained during the mission with T1 (893-897 nm) and T2 (644-652 nm) features indicate goethite-dominated samples, while relatively lower wavelength T1 (832-880 nm) features indicate hematite. Hematite/goethite molar ratios varied from 0 to 1.4, and within the 880-898 nm range, T1 features were used to estimate hematite/goethite molar ratios. Post-mission X-ray analysis detected phyllosilicates, which indicates that examining beyond the VNIR (e.g., shortwave infrared, 1000-2500 nm) will enhance the detection of other minerals formed by aqueous processes. Despite the limited spectral range of VNIR point spectrometry utilized in the MARTE Mars drilling simulation project, ferric iron minerals could be identified in retrieved core material, and their distribution served to direct core subsampling for biological analysis.

  1. Indocyanine Green-Loaded Silver Nanoparticle@Polyaniline Core/Shell Theranostic Nanocomposites for Photoacoustic/Near-Infrared Fluorescence Imaging-Guided and Single-Light-Triggered Photothermal and Photodynamic Therapy.

    Science.gov (United States)

    Tan, Xiaoxiao; Wang, Jinping; Pang, Xiaojuan; Liu, Li; Sun, Qi; You, Qing; Tan, Fengping; Li, Nan

    2016-12-28

    Photoacoustic (PA)/near-infrared fluorescence (NIRF) dual-modal imaging-guided phototherapy has been wide explored very recently. However, the development of high-efficiency and simplified-performed theranostic system for amplifying imaging-guided photothermal therapy/photodynamic therapy (PTT/PDT) is still a great challenge. Herein, a single-light-triggered indocyanine green (ICG)-loaded PEGylation silver nanoparticle core/polyaniline shell (Ag@PANI) nanocomposites (ICG-Ag@PANI) for PA/NIRF imaging-guided enhanced PTT/PDT synergistic effect has been successfully constructed. In this study, the synthesized Ag@PANI nanocomposites are utilized not only as the promising photothermal agent but also as potential nanovehicles for loading photosensitizer ICG via π-π stacking and hydrophobic interaction. The as-prepared ICG-Ag@PANI possesses many superior properties such as strong optical absorption in the near-infrared (NIR) region, enhanced photostability of ICG, as well as outstanding NIR laser-induced local hyperthermia and reactive oxygen species (ROS) generation. In the in vivo study, PA/NIRF dual-modal imaging confirms the accumulation and distribution of ICG-Ag@PANI in the tumor region via enhanced permeability and retention (EPR) effect. Moreover, the PTT effect of ICG-Ag@PANI rapidly raised the tumor temperature to 56.8 °C within 5 min. It is also demonstrated that the cytotoxic ROS generation ability of ICG is well maintained after being loaded onto Ag@PANI nanocomposites. Remarkably, in comparison with PTT or PDT alone, the single 808 nm NIR laser-triggered combined PTT/PDT therapy exhibits enhanced HeLa cells lethality in vitro and tumor growth inhibition in vivo.

  2. Cu2-xSe@mSiO2-PEG core-shell nanoparticles: a low-toxic and efficient difunctional nanoplatform for chemo-photothermal therapy under near infrared light radiation with a safe power density

    Science.gov (United States)

    Liu, Xijian; Wang, Qian; Li, Chun; Zou, Rujia; Li, Bo; Song, Guosheng; Xu, Kaibing; Zheng, Yun; Hu, Junqing

    2014-03-01

    A low-toxic difunctional nanoplatform integrating both photothermal therapy and chemotherapy for killing cancer cells using Cu2-xSe@mSiO2-PEG core-shell nanoparticles is reported. Silica coating and further PEG modification improve the hydrophilicity and biocompatibility of copper selenide nanoparticles. As-prepared Cu2-xSe@mSiO2-PEG nanoparticles not only display strong near infrared (NIR) region absorption and good photothermal effect, but also exhibit excellent biocompatibility. The mesoporous silica shell is provided as the carrier for loading the anticancer drug, doxorubicin (DOX). Moreover, the release of DOX from Cu2-xSe@mSiO2-PEG core-shell nanoparticles can be triggered by pH and NIR light, resulting in a synergistic effect for killing cancer cells. Importantly, the combination of photothermal therapy and chemotherapy driven by NIR radiation with safe power density significantly improves the therapeutic efficacy, and demonstrates better therapeutic effects for cancer treatment than individual therapy.A low-toxic difunctional nanoplatform integrating both photothermal therapy and chemotherapy for killing cancer cells using Cu2-xSe@mSiO2-PEG core-shell nanoparticles is reported. Silica coating and further PEG modification improve the hydrophilicity and biocompatibility of copper selenide nanoparticles. As-prepared Cu2-xSe@mSiO2-PEG nanoparticles not only display strong near infrared (NIR) region absorption and good photothermal effect, but also exhibit excellent biocompatibility. The mesoporous silica shell is provided as the carrier for loading the anticancer drug, doxorubicin (DOX). Moreover, the release of DOX from Cu2-xSe@mSiO2-PEG core-shell nanoparticles can be triggered by pH and NIR light, resulting in a synergistic effect for killing cancer cells. Importantly, the combination of photothermal therapy and chemotherapy driven by NIR radiation with safe power density significantly improves the therapeutic efficacy, and demonstrates better therapeutic

  3. Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

    Science.gov (United States)

    Kawauchi, Satoko; Nishidate, Izumi; Nawashiro, Hiroshi; Sato, Shunichi

    2014-03-01

    To understand the pathophysiology of ischemic stroke, in vivo imaging of the brain tissue viability and related spreading depolarization is crucial. In the infarct core, impairment of energy metabolism causes anoxic depolarization (AD), which considerably increases energy consumption, accelerating irreversible neuronal damage. In the peri-infarct penumbra region, where tissue is still reversible despite limited blood flow, peri-infarct depolarization (PID) occurs, exacerbating energy deficit and hence expanding the infarct area. We previously showed that light-scattering signal, which is sensitive to cellular/subcellular structural integrity, was correlated with AD and brain tissue viability in a rat hypoxia-reoxygenation model. In the present study, we performed transcranial NIR diffuse reflectance imaging of the rat brain during middle cerebral artery (MCA) occlusion and examined whether the infarct core and PIDs can be detected. Immediately after occluding the left MCA, light scattering started to increase focally in the occlusion site and a bright region was generated near the occlusion site and spread over the left entire cortex, which was followed by a dark region, showing the occurrence of PID. The PID was generated repetitively and the number of times of occurrence in a rat ranged from four to ten within 1 hour after occlusion (n=4). The scattering increase in the occlusion site was irreversible and the area with increased scattering expanded with increasing the number of PIDs, indicating an expansion of the infarct core. These results suggest the usefulness of NIR diffuse reflectance signal to visualize spatiotemporal changes in the infarct area and PIDs.

  4. S-CANDELS: The Spitzer-Cosmic Assembly Near-Infrared Deep Extragalactic Survey. Survey Design, Photometry, and Deep IRAC Source Counts

    CERN Document Server

    Ashby, M L N; Fazio, G G; Dunlop, J S; Egami, E; Faber, S M; Ferguson, H C; Grogin, N A; Hora, J L; Huang, J -S; Koekemoer, A M; Labbe, I; Wang, Z

    2015-01-01

    The Spitzer-Cosmic Assembly Deep Near-Infrared Extragalactic Legacy Survey (S-CANDELS; PI G. Fazio) is a Cycle 8 Exploration Program designed to detect galaxies at very high redshifts (z > 5). To mitigate the effects of cosmic variance and also to take advantage of deep coextensive coverage in multiple bands by the Hubble Space Telescope Multi-Cycle Treasury Program CANDELS, S-CANDELS was carried out within five widely separated extragalactic fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the HST Deep Field North, and the Extended Groth Strip. S-CANDELS builds upon the existing coverage of these fields from the Spitzer Extended Deep Survey (SEDS) by increasing the integration time from 12 hours to a total of 50 hours but within a smaller area, 0.16 square degrees. The additional depth significantly increases the survey completeness at faint magnitudes. This paper describes the S-CANDELS survey design, processing, and publicly-available data products. We present IRAC dual-...

  5. High-resolution Fourier-transform cavity-enhanced absorption spectroscopy in the near-infrared using an incoherent broad-band light source.

    Science.gov (United States)

    Orphal, Johannes; Ruth, Albert A

    2008-11-10

    An incoherent broad-band cavity-enhanced absorption (IBB-CEA) set-up was used in combination with a Fourier-transform (FT) spectrometer in order to explore the potential of this technique for high-resolution molecular spectroscopy in the near-infrared region. Absorption spectra of overtone bands of CO2, OCS, and HD18O were measured between 5800 and 7000 cm(-1) using a small sampling volume (1100 cm3, based on a 90 cm cavity length). The quality of the spectra in this study is comparable to that obtained with Fourier transform spectrometers employing standard multi-pass reflection cells, which require substantially larger sampling volumes. High-resolution methods such as FT-IBB-CEAS also provide an elegant way to determine effective mirror reflectivities (R(eff), i.e. a measure of the inherent overall cavity loss) by using a calibration gas with well-known line strengths. For narrow absorption features and non-congested spectra this approach does not even require a zero-absorption measurement with the empty cavity. Absolute cross-sections or line strengths of a target species can also be determined in one single measurement, if gas mixtures with known partial pressures are used. This feature of FT-IBB-CEAS reduces systematic errors significantly; it is illustrated based on CO2 as calibration gas.

  6. Understanding Radio-Selected Thermal Sources in M 33: Ultraviolet, Optical, Near-Infrared, Spitzer Mid-Infrared, and Radio Observations

    CERN Document Server

    Buckalew, B A; Darnel, J M; Polomski, E; Gehrz, R D; Humphreys, R M; Woodward, C E; Hinz, J L; Engelbracht, C W; Gordon, K D; Misselt, K; Pérez-González, P G; Rieke, G H; Willner, S P; Ashby, M L N; Barmby, P; Pahre, M A; Roellig, T L; Devereux, N; Van Loon, J T; Brandl, B; Buckalew, Brent A.; Kobulnicky, Henry A.; Darnel, Jonathan M.; Polomski, Elisha; Gehrz, Robert D.; Humphreys, Roberta M.; Woodward, Charles E.; Hinz, Joannah L.; Gordon, Karl D.; Rieke, George H.; Devereux, Nick; Loon, Jacco Th. Van

    2005-01-01

    We present ultraviolet, optical, near-infrared, Spitzer mid-infrared, and radio images of 14 radio-selected objects in M 33. These objects are thought to represent the youngest phase of star cluster formation. We have detected the majority of cluster candidates in M 33 at all wavelengths. From the near-IR images, we derived ages 2-10 Myr, K_S-band extinctions (A_K_S) of 0-1 mag, and stellar masses of 10^3-10^4 M_solar. We have generated spectral energy distributions (SEDs) of each cluster from 0.1 micron to 160 microns. From these SEDs, we have modeled the dust emission around these star clusters to determine the dust masses (1-10^3 M_solar) and temperatures (40-90 K) of the clusters' local interstellar medium. Extinctions derived from the JHK_S, Halpha, and UV images are similar to within a factor of 2 or 3. These results suggest that eleven of the fourteen radio-selected objects are optically-visible young star clusters with a surrounding H II region, that two are background objects, possibly AGN, and that ...

  7. All solution processed low turn-on voltage near infrared LEDs based on core-shell PbS-CdS quantum dots with inverted device structure.

    Science.gov (United States)

    Sanchez, Rafael S; Binetti, Enrico; Torre, Jose A; Garcia-Belmonte, G; Striccoli, Marinella; Mora-Sero, Ivan

    2014-08-07

    Colloidal semiconductor quantum dots (QDs) are extraordinarily appealing for the development of light emitting devices (LEDs) due to tunable and pure color emission, brightness and solution processability. This last advantage of the QD-LEDs is even more evident in the field of infrared emission where the devices currently used are prepared by high cost epitaxial techniques. Here we show the fabrication of low cost NIR QD-LEDs based on high quantum yield core-shell PbS-CdS QDs and a novel inverted device structure. Devices are produced using SnO2:F (FTO) as the conductive transparent contact, nanostructured TiO2 as the electron transport layer (ETL) and poly(3-hexylthiophene) P3HT as the hole transport layer (HTL). Despite the roughness of this ETL, the obtained external quantum efficiencies (EQEs) are similar to previously reported values, obtained with regular configuration and more expensive ITO substrates. A turn-on voltage as low as the QD band gap (1.47 eV) is achieved for a large area (1.54 cm(2)) and relatively stable QD-LEDs.

  8. Ability of combined Near-Infrared Spectroscopy-Intravascular Ultrasound (NIRS-IVUS) imaging to detect lipid core plaques and estimate cap thickness in human autopsy coronary arteries

    Science.gov (United States)

    Grainger, S. J.; Su, J. L.; Greiner, C. A.; Saybolt, M. D.; Wilensky, R. L.; Raichlen, J. S.; Madden, S. P.; Muller, J. E.

    2016-03-01

    The ability to determine plaque cap thickness during catheterization is thought to be of clinical importance for plaque vulnerability assessment. While methods to compositionally assess cap integrity are in development, a method utilizing currently available tools to measure cap thickness is highly desirable. NIRS-IVUS is a commercially available dual imaging method in current clinical use that may provide cap thickness information to the skilled reader; however, this is as yet unproven. Ten autopsy hearts (n=15 arterial segments) were scanned with the multimodality NIRS-IVUS catheter (TVC Imaging System, Infraredx, Inc.) to identify lipid core plaques (LCPs). Skilled readers made predictions of cap thickness over regions of chemogram LCP, using NIRS-IVUS. Artery segments were perfusion fixed and cut into 2 mm serial blocks. Thin sections stained with Movat's pentachrome were analyzed for cap thickness at LCP regions. Block level predictions were compared to histology, as classified by a blinded pathologist. Within 15 arterial segments, 117 chemogram blocks were found by NIRS to contain LCP. Utilizing NIRSIVUS, chemogram blocks were divided into 4 categories: thin capped fibroatheromas (TCFA), thick capped fibroatheromas (ThCFA), pathological intimal thickening (PIT)/lipid pool (no defined cap), and calcified/unable to determine cap thickness. Sensitivities/specificities for thin cap fibroatheromas, thick cap fibroatheromas, and PIT/lipid pools were 0.54/0.99, 0.68/0.88, and 0.80/0.97, respectively. The overall accuracy rate was 70.1% (including 22 blocks unable to predict, p = 0.075). In the absence of calcium, NIRS-IVUS imaging provided predictions of cap thickness over LCP with moderate accuracy. The ability of this multimodality imaging method to identify vulnerable coronary plaques requires further assessment in both larger autopsy studies, and clinical studies in patients undergoing NIRS-IVUS imaging.

  9. Precise radial velocities in the near infrared

    Science.gov (United States)

    Redman, Stephen L.

    Since the first detection of a planet outside our Solar System byWolszczan & Frail (1992), over 500 exoplanets have been found to date2, none of which resemble the Earth. Most of these planets were discovered by measuring the radial velocity (hereafter, RV) of the host star, which wobbles under the gravitational influence of any existing planetary companions. However, this method has yet to achieve the sub-m/s precision necessary to detect an Earth-mass planet in the Habitable Zone (the region around a star that can support liquid water; hereafter, HZ) (Kasting et al. 1993) around a Solar-type star. Even though Kepler (Borucki et al. 2010) has announced several Earth-sized HZ candidates, these targets will be exceptionally difficult to confirm with current astrophysical spectrographs (Borucki et al. 2011). The fastest way to discover and confirm potentiallyhabitable Earth-mass planets is to observe stars with lower masses - in particular, late M dwarfs. While M dwarfs are readily abundant, comprising some 70% of the local stellar population, their low optical luminosity presents a formidable challenge to current optical RV instruments. By observing in the near-infrared (hereafter, NIR), where the flux from M dwarfs peaks, we can potentially reach low RV precisions with significantly less telescope time than would be required by a comparable optical instrument. However, NIR precision RV measurements are a relatively new idea and replete with challenges: IR arrays, unlike CCDs, are sensitive to the thermal background; modal noise is a bigger issue in the NIR than in the optical; and the NIR currently lacks the calibration sources like the very successful thorium-argon (hereafter, ThAr) hollow-cathode lamp and Iodine gas cell of the optical. The PSU Pathfinder (hereafter, Pathfinder) was designed to explore these technical issues with the intention of mitigating these problems for future NIR high-resolution spectrographs, such as the Habitable-Zone Planet Finder (HZPF

  10. Intraoperative near-infrared autofluorescence imaging of parathyroid glands.

    Science.gov (United States)

    Ladurner, Roland; Sommerey, Sandra; Arabi, Nora Al; Hallfeldt, Klaus K J; Stepp, Herbert; Gallwas, Julia K S

    2017-08-01

    To identify parathyroid glands intraoperatively by exposing their autofluorescence using near-infrared light. Fluorescence imaging was carried out during minimally invasive and open parathyroid and thyroid surgery. After identification, the parathyroid glands as well as the surrounding tissue were exposed to near-infrared (NIR) light with a wavelength of 690-770 nm using a modified Karl Storz near-infrared/indocyanine green (NIR/ICG) endoscopic system. Parathyroid tissue was expected to show near-infrared autofluorescence, captured in the blue channel of the camera. Whenever possible the visual identification of parathyroid tissue was confirmed histologically. In preliminary investigations, using the original NIR/ICG endoscopic system we noticed considerable interference of light in the blue channel overlying the autofluorescence. Therefore, we modified the light source by interposing additional filters. In a second series, we investigated 35 parathyroid glands from 25 patients. Twenty-seven glands were identified correctly based on NIR autofluorescence. Regarding the extent of autofluorescence, there were no noticeable differences between parathyroid adenomas, hyperplasia and normal parathyroid glands. In contrast, thyroid tissue, lymph nodes and adipose tissue revealed no substantial autofluorescence. Parathyroid tissue is characterized by showing autofluorescence in the near-infrared spectrum. This effect can be used to distinguish parathyroid glands from other cervical tissue entities.

  11. The DENIS & 2MASS Near Infrared Surveys

    CERN Document Server

    Mamon, G A

    1996-01-01

    The DENIS and 2MASS near infrared surveys are presented. Their applications in extragalactic astronomy and cosmology are listed. The prospects for a rapid spectroscopic followup survey of a near infrared selected sample of nearly $10^5$ galaxies are illustrated with Monte-Carlo simulations.

  12. 基于近红外光谱法的多组分复杂溢油源定量建模分析%Quantitative Analysis Model of Multi-Component Complex Oil Spill Source Based on Near Infrared Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    谈爱玲; 毕卫红

    2012-01-01

    Near infrared spectroscopy technology was used for quantitative analysis of the simulation of complex oil spill source. Three light petroleum products, i. e. gasoline, diesel fuel and kerosene oil, were selected and configured as simulated mixture of oil spill samples in accordance with different concentrations proportion, and their near infrared spectroscopy in the range of 8 000 —12 000 cm"1 was collected by Fourier transform near infrared spectrometer. After processing the NIR spectra with different pretreatment methods, partial least squares method was used to establish quantitative analysis model for the mixture of oil spill samples. For gasoline, diesel fuel and kerosene oil, the second derivative method is the optimal pretreatment method, and for these three oil components in the ranges of 8 501. 3—7 999. 8 and 6 102.1—4 597. 8 cm"1; 6 549. 5~4 597. 8;7 999. 8—7 498. 4 and 102.1—4 597. 8 cm"1, the correlation coefficients i?2 of the prediction model are 0. 998 2, 0. 990 2 and 0. 993 6 respectively, while the forecast RMSEP indicators are 0. 474 7, 0. 936 1 and 1. 013 1 respectively; The experimental results show that using near infrared spectroscopy can quantitatively determine the content of each component in the simulated mixed oil spill samples, thus this method can provide effective means for the quantitative detection and analysis of complex marine oil spill source.%研究利用近红外光谱分析方法进行模拟复杂混合溢油源的定量分析问题.选取汽油、柴油、煤油三种轻质石油类产品,按照不同浓度比例配置成40个模拟混合溢油样本,利用傅里叶变换近红外光谱仪采集其在4 000~12 000 cm-1谱区范围内的近红外光谱;采用不同预处理方法,利用偏最小二乘算法建立混合溢油样本三组分各自的浓度定量模型.汽油、柴油和煤油的最优预处理方法均为二阶导数方法,分别在8501.3~7 999.8 cm-1,6 102.1~4 597.8 cm-1,6 549.5~4 597.8 cm-1

  13. Towards high efficiency air-processed near-infrared responsive photovoltaics: bulk heterojunction solar cells based on PbS/CdS core-shell quantum dots and TiO2 nanorod arrays.

    Science.gov (United States)

    Gonfa, Belete Atomsa; Kim, Mee Rahn; Delegan, Nazar; Tavares, Ana C; Izquierdo, Ricardo; Wu, Nianqiang; El Khakani, My Ali; Ma, Dongling

    2015-06-14

    Near infrared (NIR) PbS quantum dots (QDs) have attracted significant research interest in solar cell applications as they offer several advantages, such as tunable band gaps, capability of absorbing NIR photons, low cost solution processability and high potential for multiple exciton generation. Nonetheless, reports on solar cells based on NIR PbS/CdS core-shell QDs, which are in general more stable and better passivated than PbS QDs and thus more promising for solar cell applications, remain very rare. Herein we report high efficiency bulk heterojunction QD solar cells involving hydrothermally grown TiO2 nanorod arrays and PbS/CdS core-shell QDs processed in air (except for a device thermal annealing step) with a photoresponse extended to wavelengths >1200 nm and with a power conversion efficiency (PCE) as high as 4.43%. This efficiency was achieved by introducing a thin, sputter-deposited, uniform TiO2 seed layer to improve the interface between the TiO2 nanorod arrays and the front electrode, by optimizing TiO2 nanorod length and by conducting QD annealing treatment to enhance charge carrier transport. It was found that the effect of the seed layer became more obvious when the TiO2 nanorods were longer. Although photocurrent did not change much, both open circuit voltage and fill factor clearly changed with TiO2 nanorod length. This was mainly attributed to the variation of charge transport and recombination processes, as evidenced by series and shunt resistance studies. The optimal PCE was obtained at the nanorod length of ∼450 nm. Annealing is shown to further increase the PCE by ∼18%, because of the improvement of charge carrier transport in the devices as evidenced by considerably increased photocurrent. Our results clearly demonstrate the potential of the PbS/CdS core-shell QDs for the achievement of high PCE, solution processable and NIR responsive QD solar cells.

  14. Near-infrared counterparts to Chandra X-ray sources toward the Galactic Center. II. Discovery of Wolf-Rayet stars and O supergiants

    CERN Document Server

    Mauerhan, Jon C; Morris, Mark R; Stolovy, Susan R; Cotera, Angela S

    2009-01-01

    We present new identifications of infrared counterparts to the population of hard X-ray sources near the Galactic center detected by the Chandra X-ray Observatory. We have confirmed 16 new massive stellar counterparts to the X-ray population, including nitrogen-type (WN) and carbon-type (WC) Wolf-Rayet stars, and O supergiants. For the majority of these sources, the X-ray photometry is consistent with thermal emission from plasma having temperatures in the range of kT=1-8 keV or non-thermal emission having power-law indices in the range of -1sources have exhibited X-ray variability of several factors between separate observations. The X-ray properties are not a ubiquitous feature of single massive stars but are typical of massive binaries, in which the high-energy emission is generated by the collision of supersonic winds, or by accretion onto a compact companion. However, the possibility of intrinsic hard X-ray generation from...

  15. Estimation of basic density of Eucalyptus globulus using near-infrared spectroscopy

    National Research Council Canada - National Science Library

    Muneri, Allie; Raymond, Carolyn A; Michell, Anthony J; Schimleck, Laurence R

    1999-01-01

    .... A method for estimating pulp yields has been developed by measuring the near-infrared spectra of wood powders from cores withdrawn from standing eucalypt plantation trees using motorized equipment...

  16. Near-infrared variability study of the central 2.3 arcmin × 2.3 arcmin of the Galactic Centre - I. Catalogue of variable sources

    Science.gov (United States)

    Dong, Hui; Schödel, Rainer; Williams, Benjamin F.; Nogueras-Lara, Francisco; Gallego-Cano, Eulalia; Gallego-Calvente, Teresa; Wang, Q. Daniel; Morris, Mark R.; Do, Tuan; Ghez, Andrea

    2017-09-01

    We used 4-yr baseline Hubble Space Telescope/Wide Field Camera 3 IR observations of the Galactic Centre in the F153M band (1.53 μm) to identify variable stars in the central ∼2.3 arcmin × 2.3 arcmin field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sample of 33 070 stars. For 36 of the latter ones, we also derived their periods (<3 d). Our catalogue not only confirms bright long period variables and massive eclipsing binaries identified in previous works but also contains many newly recognized dim variable stars. For example, we found δ Scuti and RR Lyrae stars towards the Galactic Centre for the first time, as well as one BL Her star (period < 1.3 d). We cross-correlated our catalogue with previous spectroscopic studies and found that 319 variables have well-defined stellar types, such as Wolf-Rayet, OB main sequence, supergiants and asymptotic giant branch stars. We used colours and magnitudes to infer the probable variable types for those stars without accurately measured periods or spectroscopic information. We conclude that the majority of unclassified variables could potentially be eclipsing/ellipsoidal binaries and Type II Cepheids. Our source catalogue will be valuable for future studies aimed at constraining the distance, star formation history and massive binary fraction of the Milky Way nuclear star cluster.

  17. Functional near-infrared imager

    Science.gov (United States)

    Luo, Qingming; Nioka, Shoko; Chance, Britton

    1997-08-01

    We developed a continuous wave (cw) light imaging probe which includes 9 light sources and four pairs detectors (each pair has one 850 nm filtered detector and one 760 nm filtered detector). The light sources are controlled by a computer and the signals from the detectors are converted and processed in the computer. There are 16 measurement sections and total detection area is 9 cm multiplied by 4 cm which can be scanned every 8 seconds. The detector-source uses 2.5 cm spacing. In this study, we present the noise, drift, detectivity and spatial resolution test results of the imager. Changes of oxygenation and blood volume in about 2 cm depth from the surface of brain model can be detected. The temporal resolution is 8 seconds and spatial resolution is about 2 cm. The detectivity of OD changes can reach 0.008. With this cw imaging probe, we measured motor function in motor cortex area, visual function in occipital area, and cognitive activity in frontal forehead area of the human brian when the subjects are stimulated by moving fingers, viewing a flashing light and doing an analogy test, respectively. The experimental results show that the cw imaging probe can be used for functional images of brain activity, base upon changes of oxygenation and blood volume due to the stimulus.

  18. Near-infrared hyperspectral reflective confocal microscopy

    Science.gov (United States)

    Huang, Wei; Zhang, Yunhai; Miao, Xin; Xue, Xiaojun; Xiao, Yun

    2016-10-01

    A Near-Infrared HyperSpectral Reflective Confocal Microscopy (NIHS-RCM) is proposed in order to get high resolution images of deep biological tissues such as skin. The microscopy system uses a super-continuum laser for illumination, an acousto-optic tunable filter (AOTF) for rapid selection of near-infrared spectrum, a resonant galvanometer scanner for high speed imaging (15f/s) and near-infrared avalanche diode as detector. Porcine skin and other experiments show that the microscopy system could get deep tissue images (180 μm), and show the different ingredients of tissue with different wavelength of illumination. The system has the ability of selectively imaging of multiple ingredients at deep tissue which can be used in skin diseases diagnosis and other fields.

  19. Near-infrared imaging spectrometer onboard NEXTSat-1

    Science.gov (United States)

    Jeong, Woong-Seob; Park, Sung-Joon; Moon, Bongkon; Lee, Dae-Hee; Pyo, Jeonghyun; Park, Won-Kee; Park, Youngsik; Kim, Il-Joong; Ko, Kyeongyeon; Lee, Dukhang; Kim, Min Gyu; Kim, Minjin; Ko, Jongwan; Shin, Goo-Hwan; Chae, Jangsoo; Matsumoto, Toshio

    2016-07-01

    The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the first next generation of small satellite (NEXTSat-1) in Korea. The spectro-photometric capability in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the NISS will perform the large areal imaging spectroscopic survey for astronomical objects and low background regions. We have paid careful attention to reduce the volume and to increase the total throughput. The newly implemented off-axis optics has a wide field of view (2° x 2°) and a wide wavelength range from 0.9 to 3.8μm. The mechanical structure is designed to consider launching conditions and passive cooling of the telescope. The compact dewar after relay-lens module is to operate the infrared detector and spectral filters at 80K stage. The independent integration of relay-lens part and primary-secondary mirror assembly alleviates the complex alignment process. We confirmed that the telescope and the infrared sensor can be cooled down to around 200K and 80K, respectively. The engineering qualification model of the NISS was tested in the space environment including the launch-induced vibration and shock. The NISS will be expected to demonstrate core technologies related to the development of the future infrared space telescope in Korea.

  20. Near-Infrared Polarimetry toward the Galactic Center

    CERN Document Server

    Nishiyama, Shogo; Hatano, Hirofumi; Kanai, Saori; Kurita, Mikio; Sato, Shuji; Nagata, Tetsuya

    2008-01-01

    Near-infrared polarimetry of point sources reveals the presence of a toroidal magnetic field in the central 20' x 20' region of our Galaxy. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we have obtained a polarization originating from magnetically aligned dust grains at the central region of our Galaxy of at most 1-2 kpc. The derived direction of the magnetic field is in good agreement with that obtained from far-infrared/submillimeter observations, which detect polarized thermal emission from dust in the molecular clouds at the Galactic center. Our results show that by subtracting foreground components, near-infrared polarimetry allows investigation of the magnetic field structure at the Galactic center. The distribution of the position angles shows a peak at around 20deg, nearly parallel to the direction of the Galactic plane, suggesting a toroidal magnetic configuration.

  1. Note: Near infrared interferometric silicon wafer metrology.

    Science.gov (United States)

    Choi, M S; Park, H M; Joo, K N

    2016-04-01

    In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer.

  2. 近红外发光Ag2S-CdS核壳结构水溶性量子点的合成及光学性质%Near-Infrared Emitting Ag2S-CdS Core-Shell Quantum Dots in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    成戡; 方正; 马云飞; 张华

    2013-01-01

    High-quality Ag2S-CdS core-shell water soluble quantum dots have been synthesized via growing CdS shell on the surface of Ag2S core when using glutathione (GSH) as capping agents in aqueous solution. XRD, TEM, HRTEM and EDS were used to characterize the structure, morphology and composition of the samples. The optical properties were studied by UV-Vis absorption and PL. The effects of contents of GSH, Ag and S sources on the optical property have also been studied. The experimental results show that the quantum dots exhibit near-infrared emission in the range of 710~718 nm with long lifetime and high stability. Both the PL peak position and intensity change along with the concentration of Ag and S during the growth of core, while the GSH contents only make the PL peak shift. The different optical properties could be associated with the distribution of Ag and surface states in the core-shell structured quantum dots.%本文以谷胱甘肽(GSH)作为表面活性剂,采用两步法,先生成Ag2S核,再生长CdS,得到了高质量的Ag2S-CdS核壳结构水溶性量子点.我们用XRD,TEM,HRTEM和EDS研究了产物的结构,形貌和组分,用紫外可见吸收光谱和荧光发射光谱研究了所得量子点的光学性质,同时考察了反应时间,GSH的量,Ag和S源前驱物的含量对量子点光学性质的影响.实验结果表明量子点稳定性好,荧光寿命长,可在710~718 nm近红外区域发光.在核生长过程中,Ag和S源的含量同时影响量子点的发光位置和强度,而GSH量和壳层生长中S源的量几乎只影响近红外发光强度,发光位置保持不变.不同的量子点光学性质可能来源于量子点中组分及表面缺陷的分布.

  3. NIP: the near infrared imaging photometer for Euclid

    Science.gov (United States)

    Schweitzer, Mario; Bender, Ralf; Katterloher, Reinhard; Eisenhauer, Frank; Hofmann, Reiner; Saglia, Roberto; Holmes, Rory; Krause, Oliver; Rix, Hans-Walter; Booth, Jeff; Fagrelius, Parker; Rhodes, Jason; Seshadri, Suresh; Refregier, Alexandre; Amiaux, Jerome; Augueres, Jean-Louis; Boulade, Olivier; Cara, Christophe; Amara, Adam; Lilly, Simon; Atad-Ettedgui, Eli; di Giorgio, Anna-Maria; Duvet, Ludovic; Kuehl, Christopher; Syed, Mohsin

    2010-07-01

    The NIP is a near infrared imaging photometer that is currently under investigation for the Euclid space mission in context of ESA's 2015 Cosmic Vision program. Together with the visible camera (VIS) it will form the basis of the weak lensing measurements for Euclid. The NIP channel will perform photometric imaging in 3 near infrared bands (Y, J, H) covering a wavelength range from ~ 0.9 to 2 μm over a field of view (FoV) of ~ 0.5 deg2. With the required limiting point source magnitude of 24 mAB (5 sigma) the NIP channel will be used to determine the photometric redshifts of over 2 billion galaxies collected over a wide survey area of 20 000 deg2. In addition to the photometric measurements, the NIP channel will deliver unique near infrared (NIR) imaging data over the entire extragalactic sky, enabling a wide variety of ancillary astrophysical and cosmological studies. In this paper we will present the results of the study carried out by the Euclid Imaging Consortium (EIC) during the Euclid assessment phase.

  4. Transrectal Near-Infrared Optical Tomography for Prostate Imaging

    Science.gov (United States)

    2011-03-01

    2009. CA Cancer J Clin. 2009;59:225-249. 2. Hodge KK, McNeal JE, Stamey TA. Ultrasound guided transrectal core biopsies of the palpably abnormal...near-infrared spectroscopy: pilot results in the breast," Radiology 218, 261-266 (2001). [4] Tara Yates, Jeremy C Hebden, Adam Gibson, Nick ...digital rectal examination as screening tests for prostate carcinoma,” J Am Board Fam Pract.; 16(2):95- 101 (2003). 3. Hodge KK, McNeal JE, Stamey TA

  5. [Application of near infrared spectroscopy in analysis of wood properties].

    Science.gov (United States)

    Yao, Sheng; Pu, Jun-wen

    2009-04-01

    There is substantial interest in the improvement of wood properties through genetic selection or a change in silviculture prescription. Tree breeding purpose requires measurement of a large number of samples. However, traditional methods of assessing wood properties are both time consuming and destructive, limiting the numbers of samples that can be processed, so new method would be needed to find. Near infrared spectroscopy (NIR) is an advanced spectroscopic tool for nondestructive evaluation of wood and it can quickly, accurately estimate the properties of increment core, solid wood or wood meal. The present paper reviews the advances in the research on the wood chemistry properties and anatomical properties using NIR.

  6. Near infrared polymer light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong; YANG Jian; HOU Qiong; MO Yueqi; PENG Junbiao; CAO Yong

    2005-01-01

    High efficiency of near infrared polymer light-emitting diodes with bilayer structure was obtained. The diode structure is ITO/PEDOT/L1/L2/Ba/Al, where L1 is phenyl-substituted poly [p-phenylphenylene vinylene] derivative (P-PPV), L2 is 9,9-dioctylfluorene (DOF) and 4,7- bis(3-hexylthiophen)-2-yl-2,1,3-naphthothiadiazole (HDNT) copolymer (PFHDNT10). The electroluminescence (EL) spectrum of diodes from PFHDNT10 is at 750 nm located in the range of near infrared. The maximum external quantum efficiency is up to 2.1% at the current density of 35 mA/cm2. The improvement of the diode's performances was considered to be the irradiative excitons confined in the interface between L1 and L2 layers.

  7. Characterization of an erbium-doped fiber amplifier as a light source and development of a near-infrared spectrophotometer based on the EDFA and an acoustooptic tunable filter.

    Science.gov (United States)

    Tran, C D; Gao, G H

    1996-07-01

    A novel light source for the near-infrared region which has the highest intensity and widest spectral bandwidth of all near-IR light sources has been developed. The system is based on a single-mode fiber (about 18 m long) doped with Er3+ ion. The doped ion produces amplified spontaneous emission (ASE) in the near-IR region (from 1500 to 1600 nm) when it is excited by a diode laser at 980 nm. Because the diode laser is fusion-spliced directly to the doped fiber, the system is compact, all-solid-state, reliable, and stable and requires little maintenance. Its ASE output intensity was found to be comparable with those of diode lasers currently available for this near-IR region and is much higher than those of conventional halogen-tungsten lamps and the so-called (high-intensity) superluminescent light emitting diodes (SLEDs). Its spectral bandwidth is, however, much wider than those of the diode lasers and the SLEDs. Even higher intensity can be obtained from the doped fiber when a low-intensity (1 mW) light from a 1550-nm laser diode is introduced into the doped fiber. The intensity is enhanced (up to 7 times compared to the ASE) because the input light is amplified by the doped fiber. Furthermore, the output intensity of this erbium-doped fiber amplifier (EDFA) can be appropriately adjusted to provide relatively higher output intensity at any range of wavelengths (within this 1500-1600-nm region) by simply changing the temperature and/or the driven current of the input diode laser. Subsequently, an acoustooptic tunable filter was used to provide a means to spectrally tune the EDFA rapidly and to develop an all-solid-state, compact near-IR spectrophotometer which not only is very sensitive, stable, and reliable but also has a very high throughput. This spectrophotometer can detect water in ethanol at a limit of detection of 10 ppm. More importantly, the high through-put makes it possible to use the instrument to measure spectra of highly absorbing samples (e

  8. Near Infrared Spectra of SAGE LMC AGB Stars

    Science.gov (United States)

    Blum, Robert D.; Volk, K.; Srinivasan, S.

    2011-01-01

    We present K-band spectra of a sample of Spitzer SAGE LMC sources obtained on the 4-m SOAR telescope in Chile. The near infrared spectral classifications are compared to classifications from Spitzer IRS spectra of the same sources and to the original SAGE IRAC and MIPS photometric classifications. The SOAR Telescope is a joint project of: Conselho Nacional de Pesquisas Cientficas e Tecnolgicas CNPq-Brazil, The University of North Carolina at Chapel Hill, Michigan State University, and NOAO (which is run by the Association of Universities for Research in Astronomy on behalf of the National Science Foundation).

  9. Near-Infrared Super Resolution Imaging with Metallic Nanoshell Particle Chain Array

    CERN Document Server

    Kong, Weijie; Cao, Penfei; Cheng, Lin; Gong, Li; Zhao, Xining; Yang, Lili

    2012-01-01

    We propose a near-infrared super resolution imaging system without a lens or a mirror but with an array of metallic nanoshell particle chain. The imaging array can plasmonically transfer the near-field components of dipole sources in the incoherent and coherent manners and the super resolution images can be reconstructed in the output plane. By tunning the parameters of the metallic nanoshell particle, the plasmon resonance band of the isolate nanoshell particle red-shifts to the near-infrared region. The near-infrared super resolution images are obtained subsequently. We calculate the field intensity distribution at the different planes of imaging process using the finite element method and find that the array has super resolution imaging capability at near-infrared wavelengths. We also show that the image formation highly depends on the coherence of the dipole sources and the image-array distance.

  10. Spitzer SAGE-Spec: Near Infrared Spectroscopy, Dust Shells, and Cool Envelopes in Extreme Large Magellanic Cloud AGB Stars

    CERN Document Server

    Blum, R D; Kemper, F; Ling, B; Volk, K

    2014-01-01

    K-band spectra are presented for a sample of 39 Spitzer IRS SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near infrared - Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars were chosen from the luminous and red extreme "tip" of the color magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich "stellar" cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near infrared and mid infrared colors. One object in our sample, HV 915, a known post asymptotic giant branch star of the RV Tau type exhibits CO 2.3 micron band head emission consistent with previ...

  11. Near-infrared scintillation of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, T. [Fermilab; Escobar, C. O. [Campinas State U.; Lippincott, W. H. [Fermilab; Rubinov, P. [Fermilab

    2016-03-03

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  12. Near-infrared scintillation of liquid argon

    CERN Document Server

    Alexander, T; Lippincott, W H; Rubinov, P

    2016-01-01

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  13. Precise Near-Infrared Radial Velocities

    CERN Document Server

    Plavchan, Peter; Gagne, Jonathan; Furlan, Elise; Brinkworth, Carolyn; Bottom, Michael; Tanner, Angelle; Anglada-Escude, Guillem; White, Russel; Davison, Cassy; Mills, Sean; Beichman, Chas; Johnson, John Asher; Ciardi, David; Wallace, Kent; Mennesson, Bertrand; Vasisht, Gautam; Prato, Lisa; Kane, Stephen; Crawford, Sam; Crawford, Tim; Sung, Keeyoon; Drouin, Brian; Lin, Sean; Leifer, Stephanie; Catanzarite, Joe; Henry, Todd; von Braun, Kaspar; Walp, Bernie; Geneser, Claire; Ogden, Nick; Stufflebeam, Andrew; Pohl, Garrett; Regan, Joe

    2016-01-01

    We present the results of two 2.3 micron near-infrared radial velocity surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~46,000) at the NASA InfraRed Telescope Facility, combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20-30 m/s on our survey targets.

  14. The Gemini Near-Infrared Imager (NIRI)

    Science.gov (United States)

    Hodapp, Klaus W.; Jensen, Joseph B.; Irwin, Everett M.; Yamada, Hubert; Chung, Randolph; Fletcher, Kent; Robertson, Louis; Hora, Joseph L.; Simons, Douglas A.; Mays, Wendy; Nolan, Robert; Bec, Matthieu; Merrill, Michael; Fowler, Albert M.

    2003-12-01

    This paper presents the basic design of the Gemini Near-Infrared Imager (NIRI) and discusses its capabilities. NIRI offers three different pixel scales to match different operating modes of the Gemini telescope and allows polarimetric and spectroscopic observations. It is equipped with an infrared on-instrument wave-front sensor (OIWFS) to allow tip-tilt and focus correction even in highly obscured regions. The science detector array is an Aladdin II InSb 1024×1024 pixel device sensitive from 1.0 to 5.5 μm.

  15. Near-infrared neuroimaging with NinPy

    Directory of Open Access Journals (Sweden)

    Gary E Strangman

    2009-05-01

    Full Text Available There has been substantial recent growth in the use of non-invasive optical brain imaging in studies of human brain function in health and disease. Near-infrared neuroimaging (NIN is one of the most promising of these techniques and, although NIN hardware continues to evolve at a rapid pace, software tools supporting optical data acquisition, image processing, statistical modeling and visualization remain less refined. Python, a modular and computationally efficient development language, can support functional neuroimaging studies of diverse design and implementation. In particular, Python's easily readable syntax and modular architecture allow swift prototyping followed by efficient transition to stable production systems. As an introduction to our ongoing efforts to develop Python software tools for structural and functional neuroimaging, we discuss: (i the role of noninvasive diffuse optical imaging in measuring brain function, (ii the key computational requirements to support NIN experiments, (iii our collection of software tools to support near-infrared neuroimaging, called NinPy, and (iv future extensions of these tools that will allow integration of optical with other structural and functional neuroimaging data sources. Source code for the software discussed here will be made available at www.nmr.mgh.harvard.edu/Neural_SystemsGroup/software.html.

  16. Properties of Near-Infrared Selected AGN Candidates with 2MASS/ROSAT Catalogues

    CERN Document Server

    Kouzuma, Shinjirou

    2010-01-01

    We report on the near-infrared selected AGN candidates extracted from 2MASS/ROSAT catalogues and discuss their properties. First, near-infrared counterparts of a X-ray source in ROSAT catalogues (namely, Bright Source Catalogue (BSC) and Faint Source Catalogue (FSC)) were extracted by positional cross-identification of <=30''. Because these counterparts would contain many mis-identifications, we further imposed near-infrared colour selection criteria and extracted reliable AGN candidates (BSC: 5,273, FSC: 10,071). Of 5,273 (10,071) candidates in the BSC (FSC), 2,053 (1,008) are known AGNs. Near-infrared and X-ray properties of candidates show similar properties with known AGNs and are consistent with previous studies. We also searched for counterparts in other wavelengths (that is, optical, near-infrared, and radio), and investigated properties in multiwavelength. No significant difference between known AGNs and unclassified sources could be seen. However, some unclassified sources in the FSC showed slight...

  17. Near Infrared (nir) Imaging for Nde

    Science.gov (United States)

    Diamond, G. G.; Pallav, P.; Hutchins, D. A.

    2008-02-01

    A novel application of near infrared (NIR) signals is presented, which can be used to provide images of many different materials and objects. It is effectively a very low cost non-ionising alternative to many applications currently being investigated using electromagnetic waves at other frequencies, such as THz and X-ray imaging. This alternative technique can be realised by very simple and inexpensive electronics and is inherently far more portable and easy to use. Transmission imaging results from this technique are presented from examples industrial quality control, food inspection and various security applications, and the results compared to existing techniques. In addition, this technique can be used in through-transmission mode on biological and medical samples, and images are presented that differentiate between not only flesh and bone, but also various types of soft tissue.

  18. Near Infrared Spectroscopy Systems for Tissue Oximetry

    DEFF Research Database (Denmark)

    Petersen, Søren Dahl

    We present exible silicon device platforms, which combine polyimide with polydimethylsiloxane in order to add flexibility and biocompatibility to the silicon devices. The device platforms are intended as tissue oximeters, using near infrared spectroscopy, but could potentially also be used...... for other medical applications. The tissue oximeters are realised by incorporation of pn-diodes into the silicon in order to form arrays of infrared detectors. These arrays can then be used for spatially resolved spectroscopy measurements, with the targeted end user being prematurely born infant children...... of incidence. Thus, also minimising the drop in quantum efficiency for light incident at 38 from normal to only 5.2 % compared to a drop of 9.1 % for devices without the black silicon nanostructures. In conclusion both the flexible device platforms and infrared detectors were found to work....

  19. Optical glass: dispersion in the near infrared

    Science.gov (United States)

    Hartmann, Peter

    2011-10-01

    With deliveries of optical glass lots measurement data are given for the visible range usually from 436 nm (g-line) to 656 nm (C-line). Sometimes the question arises if refractive index values in the near infrared can be calculated from these data. With near infrared we mean the range from the C-line up to 1700 nm in this publication. The reason is that up to 1700 nm most optical glasses have hardly any reduction in their transmission. On the basis of a large amount of production data obtained over more than ten years with precision v-block refractometer evaluations are possible up to 1014 nm. The precision spectrometer URIS developed by SCHOTT enables to analyze the refractive index with measurement uncertainty fairly below 10-5 for even longer wavelengths up to 2325 nm, however on a much smaller data basis. The variability of the IR dispersion is shown for selected glass types. Frequency distributions for the different deviation shapes give information how reliable extrapolations are from the visible range to the near IR. The precision refractometer data were used to simulate such extrapolations employing partial dispersion data from catalog data sheets and to check the consistency of simulated with real data. For some glass types extrapolations seem to be possible. However, there are also glass types, where the method using catalog partial dispersions leads to significant deviations from reality. So if extrapolations are intended to be done, a general check should be performed if this is justified for the glass type of interest.

  20. Near infrared few-cycle pulses for high harmonic generation

    CERN Document Server

    Driever, Steffen; Delagnes, Jean-Christophe; Fedorov, Nikita; Arnold, Martin; Bigourd, Damien; Cormier, Eric; Guichard, Roland; Constant, Eric; Zair, Amelle

    2014-01-01

    We report on the development of tunable few-cycle pulses with central wavelengths from 1.6 um to 2 um. Theses pulses were used as a proof of principle for high harmonic generation in atomic and molecular targets. In order to generate such pulses we produced a filament in a 4 bar krypton cell. Spectral broadening by a factor of 2 to 3 of a 40 fs near infrared input pulse was achieved. The spectrally broadened output pulses were then compressed by fused silica plates down to the few-cycle regime close to the Fourier limit. The auto-correlation of these pulses revealed durations of about 3 cycles for all investigated central wavelengths. Pulses with a central wavelength of 1.7 um and up to 430 uJ energy per pulse were employed to generate high order harmonics in Xe, Ar and N2. Moving to near infrared few-cycle pulses opens the possibility to operate deeply in the non-perturbative regime with a Keldysh parameter smaller than 1. Hence, this source is suitable for the study of the non-adiabatic tunneling regime in ...

  1. Near-infrared Spectroscopy Of NEOs: Characterization Of Targets Of The ExploreNEOs (Spitzer) Program

    NARCIS (Netherlands)

    Emery, Joshua P.; Thomas, C. A.; Trilling, D. E.; Dave, R.; Delbo, M.; Mueller, M.

    2010-01-01

    In order to complement the ExploreNEOs program, we are characterizing surface compositions of near-Earth objects (NEOs) with near-infrared (NIR) spectroscopy (0.7 to 2.5 microns). The core ExploreNEOs program is an ambitious exploration of the history of near-Earth space using NASA's Spitzer space t

  2. On the Near-Infrared Size of Vega

    CERN Document Server

    Ciardi, D R; Akeson, R L; Thompson, R R; Lada, E A; Howell, S B; Ciardi, David R.; Belle, Gerard T. van; Akeson, Rachel L.; Thompson, Robert R.; Lada, Elizabeth A.; Howell, Steve B.

    2001-01-01

    Near-infrared (2.2 um) long baseline interferometric observations of Vega are presented. The stellar disk of the star has been resolved, and the data have been fitted with a limb darkened stellar disk of diameter Theta_{LD} = 3.28 +/- 0.01 mas. The derived effective temperature is T_eff = 9553 +/- 111 K. However, the residuals resulting from the stellar disk model appear to be significant and display organized structure. Instrumental artifacts, stellar surface structure, stellar atmosphere structure, and extended emission/scattering from the debris disk are discussed as possible sources of the residuals. While the current dataset cannot uniquely determine the origin of the residuals, the debris disk is found to be the most likely source. A simple debris disk model, with 3-6% of Vega's flux emanating from the disk at r < 4 AU, can explain the residuals.

  3. The Munich Near-Infrared Cluster Survey -- IV. Biases in the Completeness of Near-Infrared Imaging Data

    CERN Document Server

    Snigula, J; Bender, R; Botzler, C S; Feulner, G; Hopp, U

    2002-01-01

    We present the results of completeness simulations for the detection of point sources as well as redshifted elliptical and spiral galaxies in the K'-band images of the Munich Near-Infrared Cluster Survey (MUNICS). The main focus of this work is to quantify the selection effects introduced by threshold-based object detection algorithms used in deep imaging surveys. Therefore, we simulate objects obeying the well-known scaling relations between effective radius and central surface brightness, both for de Vaucouleurs and exponential profiles. The results of these simulations, while presented for the MUNICS project, are applicable in a much wider context to deep optical and near-infrared selected samples. We investigate the detection probability as well as the reliability for recovering the true total magnitude with Kron-like (adaptive) aperture photometry. The results are compared to the predictions of the visibility theory of Disney and Phillipps in terms of the detection rate and the lost-light fraction. Addit...

  4. Near-Infrared Intraoperative Chemiluminescence Imaging

    KAUST Repository

    Büchel, Gabriel E.

    2016-08-03

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce4+ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9pmolcm-2 of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the invivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Probing brain oxygenation with near infrared spectroscopy

    CERN Document Server

    Gersten, Alexander; Raz, Amir; Fried, Robert

    2011-01-01

    The fundamentals of near infrared spectroscopy (NIRS) are reviewed. This technique allows to measure the oxygenation of the brain tissue. The particular problems involved in detecting regional brain oxygenation (rSO2) are discussed. The dominant chromophore (light absorber) in tissue is water. Only in the NIR light region of 650-1000 nm, the overall absorption is sufficiently low, and the NIR light can be detected across a thick layer of tissues, among them the skin, the scull and the brain. In this region, there are many absorbing light chromophores, but only three are important as far as the oxygenation is concerned. They are the hemoglobin (HbO2), the deoxy-hemoglobin (Hb) and cytochrome oxidase (CtOx). In the last 20 years there was an enormous growth in the instrumentation and applications of NIRS. . The devices that were used in our experiments were : Somanetics's INVOS Brain Oximeter (IBO) and Toomim's HEG spectrophotometer. The performances of both devices were compared including their merits and draw...

  6. Near-Infrared Diffuse Optical Tomography

    Directory of Open Access Journals (Sweden)

    A. H. Hielscher

    2002-01-01

    Full Text Available Diffuse optical tomography (DOT is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI or X-ray computerized tomography (CT, DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals.

  7. Bioprocess monitoring using near-infrared spectroscopy.

    Science.gov (United States)

    Suehara, Ken-ichiro; Yano, Takuo

    2004-01-01

    Near-infrared spectroscopy (NIR) is a nondestructive analytical technique that has been used for simultaneous prediction of the concentrations of several substrates, products and constructs in mixtures sampled from fermentation processes. In this chapter, we discuss applications of NIR for the monitoring of bioprocesses involving rice vinegar, compost, glycolipid, L-glutamic acid, lactic acid fermentation, mushroom cultivation, and Koji production. This includes detailed discussion of applications of NIR to process management of rice vinegar fermentation and compost fermentation. In the present study, absorbance at wavelengths between 400 and 2500 nm was measured at 2 nm intervals. To obtain calibration equations, multiple linear regression (MLR) was performed on NIR spectral data and conventional analysis values of a calibration sample set. To validate these calibration equations, they were used to calculate concentrations of a prediction sample set, which were then compared with concentrations measured by conventional methods. There was excellent agreement between the results of the conventional method and those of the NIR method, when both were used to analyze culture broth of rice vinegar fermentation and solid-state fermented compost. These results indicate that NIR is a useful method for monitoring and control of bioprocesses.

  8. A near-infrared confocal scanner

    Science.gov (United States)

    Lee, Seungwoo; Yoo, Hongki

    2014-06-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface.

  9. Near infrared spectroscopy in natural products analysis.

    Science.gov (United States)

    Cozzolino, Daniel

    2009-06-01

    Several medicinal and herbal plants properties are related to individual compounds such as essential oils, terpenoids, flavonoids, which are present in natural products in low concentrations (e. g., ppm or ppb). For many years, the use of classical separation and chromatographic and spectrometric techniques such as high performance liquid chromatography (HPLC), gas chromatography (GC), liquid chromatography (LC) and mass spectrometry (MS) were initially used for the elucidation of isolated compounds from different plant matrices. Spectroscopic techniques in the infrared (IR) wavelength region of the electromagnetic spectrum have been used in the food industry to monitor and evaluate the composition of foods. Although Herschel discovered light in the near-infrared (NIR) region as early as 1800, most spectroscopists of the first half of the last century ignored it, in the belief that it lacked any analytical interest. However, during the last 40 years NIR spectroscopy has become one of the most attractive and used methods for analysis. This mini-review highlights recent applications of NIR spectroscopy to the qualitative and quantitative analysis of plant natural products.

  10. TIRSPEC : TIFR Near Infrared Spectrometer and Imager

    CERN Document Server

    Ninan, J P; Ghosh, S K; D'Costa, S L A; Naik, M B; Poojary, S S; Sandimani, P R; Meshram, G S; Jadhav, R B; Bhagat, S B; Gharat, S M; Bakalkar, C B; Prabhu, T P; Anupama, G C; Toomey, D W

    2014-01-01

    We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT), Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The TIRSPEC provides for various modes of operation which include photometry with broad and narrow band filters, spectrometry in single order mode with long slits of 300" length and different widths, with order sorter filters in the Y, J, H and K bands and a grism as the dispersing element as well as a cross dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was successfully commissioned in June 2013 and the subsequent characterization and astronomical observatio...

  11. Biochemical and physiological basis of medical near-infrared spectroscopy

    Science.gov (United States)

    Joebsis-vander Vliet, Frans F.; Joebsis, Paul

    1999-10-01

    Near infrared spectroscopy (NIRS) can monitor both the redox status of Cytochrome c oxidase located in the mitochondria within the cell and the oxygenation of the blood in the tissue being monitored. Since the enzyme catalyzes more than 90% of oxygen utilization, it is the sink for the oxygen while the hemoglobin in the capillaries is the oxygen source. In order to evaluate the oxidative metabolic status of a tissue the optical data obtained from both molecules are commonly interpreted in the basis of test tube experiments with purified preparations. We are concerned that the validity of this practice may not have been tested sufficiently and raise four basic questions that have not yet been answered. Citing some examples of in vitro versus in vivo differences we conclude that more effort should be expended on the in vivo testing of the range of the signals, their natural variability, and the physiological and pathological meaning of their deviations from norm.

  12. NIRS - Near infrared spectroscopy - investigations in neurovascular diseases

    DEFF Research Database (Denmark)

    Schytz, Henrik Winther

    2015-01-01

    in cerebral blood flow (CBF), the first study investigated a multi-source detector separation configuration and indocyanine green (ICG) as a tracer to calculate a corrected blood flow index (BFI) value. The study showed no correlation between CBF changes measured by 133Xenon single photon emission computer......The purpose of this thesis was to explore and develop methods, where continuous wave near infrared spectroscopy (CW-NIRS) can be applied in different neurovascular diseases, in order to find biological markers that are useful in clinical neurology. To develop a new method to detect changes...... tomography (133Xe-SPECT) and the corrected BFI value. It was concluded, that it was not possible to obtain reliable BFI data with the ICG CW-NIRS method. NIRS measurements of low frequency oscillations (LFOs) may be a reliable method to investigate vascular alterations in neurovascular diseases...

  13. Near infrared spectroscopy of food systems using a supercontinuum laser

    DEFF Research Database (Denmark)

    Ringsted, Tine

    applied near- and mid-infrared incandescent light bulbs. This thesis aim to explore the utility of using a supercontinuum source in two food applications. (1) The supercontinuum light was applied for the first time to barley seeds in transmission mode in the long wavelength near-infrared region from 2260......-2380 nm. From these spectra it was possible to predict the β-glucan content of individual seeds. The measurements of single seeds can be used in plant breeding to sort according to trait or in grain industries to sort according to quality or property. (2) The supercontinuum light has been used with a new...... wavelength separation method called dispersive Fourier transformation. Different wavelengths travel at different speed through a dispersive element, which in this case is a 10.6 km long silica fiber, and the polychromatic light pulses will therefore be separated by wavelength. The signal...

  14. Near-Infrared Imaging Polarimetry of Young Stellar Objects in rho-Ophiuchi

    CERN Document Server

    Beckford, A F; Chrysostomou, A C; Gledhill, T M

    2008-01-01

    The results of a near-infrared (J H K LP) imaging linear polarimetry survey of 20 young stellar objects (YSOs) in rho Ophiuchi are presented. The majority of the sources are unresolved, with K-band polarizations, P_K 20 per cent are seen over their envelopes. Correlations are observed between the degree of core polarization and the evolutionary status inferred from the spectral energy distribution. K-band core polarizations >6 per cent are only observed in Class I YSOs. A 3D Monte Carlo model with oblate grains aligned with a magnetic field is used to investigate the flux distributions and polarization structures of three of the rho Oph YSOs with extended nebulae. A rho proportional to r^(-1.5) power law for the density is applied throughout the envelopes. The large-scale centrosymmetric polarization structures are due to scattering. However, the polarization structure in the bright core of the nebula appears to require dichroic extinction by aligned non-spherical dust grains. The position angle indicates a ...

  15. Investigation of graphene applied on near infrared photodetector (Conference Presentation)

    Science.gov (United States)

    Lien, I.-Chun; Chen, Sheng-Hui

    2016-10-01

    The particular Graphene-Germanium-Graphene photodetector (GSG PD) is investigated in this research. Germanium has good absorption coefficient in near infrared such as 850 nm, 1310 nm and 1550 nm which are commonly used in optics communication. Generally, the metal electrode was utilized for photodetector and there were lots of light being loss. In recent years, graphene is found to be a good conductive film. It is a two-dimensional monolayer of sp2-bonded carbon atoms. In cases where synthesized by chemical vapor deposition (CVD), graphene is especially a promising candidate for transparent conductive films (TCFs) due to its exceptional electrical conductivity and high optical transmittance which is almost transparent in the wide wavelength range, especially including near infrared. Therefore, the higher photo current and responsivity of the device can be achieved. In this investigation, interdigitated graphene electrodes are used on the devices with the purposes of a relatively easy process for high-speed devices and a comparable process for the integrated circuit. We used the n-type Germanium as the substrates for the absorption of photodetector and different layers of graphene as the interdigitated electrodes. The interdigitated graphene electrode is prepared by transferred the graphene which is grown by CVD on the substrate first and then pattern by O2 plasma. The most direct method of measuring the photo current is to be incident a laser source by fiber and give a DC bias then using KEITHLEY 2400 Source Meter to measure current from photodetectors. As the result of that, we can calculate the responsivity by formula.

  16. NEAR-INFRARED SPECTROSCOPY OF POST-AGB STARS

    NARCIS (Netherlands)

    OUDMAIJER, RD; WATERS, LBFM; VANDERVEEN, WECJ; GEBALLE, TR

    1995-01-01

    The results of a medium resolution near-infrared spectral survey of 18 post-AGB candidate stars are presented. Most of the stars have near-infrared hydrogen lines in absorption, which is normal for their spectral types. Three stars, HD 101584, HD 179821 and HD 170756 have the CO first overtone bands

  17. Taxonomic Classification of Asteroids via Broadband Near-Infrared Photometry

    NARCIS (Netherlands)

    Petersen, Eric; Thomas, C.; Trilling, D.; Emery, J.; Delbo, M.; Mueller, M.; Dave, R.

    2010-01-01

    For faint asteroids, it is not practical to obtain near-infrared spectra. However, it may be possible to use broadband photometry to infer spectral classifications and study composition. As a test of this, we processed SpeX near-infrared asteroid spectral data to simulate colors that would be obtain

  18. CHARACTERISTIC SIZE OF FLARE KERNELS IN THE VISIBLE AND NEAR-INFRARED CONTINUA

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yan; Jing, Ju; Wang, Haimin [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States); Cao, Wenda, E-mail: yx2@njit.edu [Big Bear Solar Observatory, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 (United States)

    2012-05-01

    In this Letter, we present a new approach to estimate the formation height of visible and near-infrared emission of an X10 flare. The sizes of flare emission cores in three wavelengths are accurately measured during the peak of the flare. The source size is the largest in the G band at 4308 A and shrinks toward longer wavelengths, namely the green continuum at 5200 A and NIR at 15600 A, where the emission is believed to originate from the deeper atmosphere. This size-wavelength variation is likely explained by the direct heating model as electrons need to move along converging field lines from the corona to the photosphere. Therefore, one can observe the smallest source, which in our case is 0.''65 {+-} 0.''02 in the bottom layer (represented by NIR), and observe relatively larger kernels in upper layers of 1.''03 {+-} 0.''14 and 1.''96 {+-} 0.''27, using the green continuum and G band, respectively. We then compare the source sizes with a simple magnetic geometry to derive the formation height of the white-light sources and magnetic pressure in different layers inside the flare loop.

  19. AKARI/IRC NEAR-INFRARED SPECTRAL ATLAS OF GALACTIC PLANETARY NEBULAE

    Energy Technology Data Exchange (ETDEWEB)

    Ohsawa, Ryou [Institute of Astronomy, Graduate School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Onaka, Takashi; Sakon, Itsuki [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Matsuura, Mikako [School of Physics and Astronomy, Cardiff University, Queen’s Buildings, 5 The Parade, Roath, Cardiff CF24 3AA (United Kingdom); Kaneda, Hidehiro, E-mail: ohsawa@ioa.s.u-tokyo.ac.jp [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)

    2016-04-15

    Near-infrared (2.5–5.0 μm) low-resolution (λ/Δλ ∼ 100) spectra of 72 Galactic planetary nebulae (PNe) were obtained with the Infrared Camera (IRC) in the post-helium phase. The IRC, equipped with a 1′ × 1′ window for spectroscopy of a point source, was capable of obtaining near-infrared spectra in a slit-less mode without any flux loss due to a slit. The spectra show emission features including hydrogen recombination lines and the 3.3–3.5 μm hydrocarbon features. The intensity and equivalent width of the emission features were measured by spectral fitting. We made a catalog providing unique information on the investigation of the near-infrared emission of PNe. In this paper, details of the observations and characteristics of the catalog are described.

  20. AKARI/IRC Near-Infrared Spectral Atlas of Galactic Planetary Nebulae

    CERN Document Server

    Ohsawa, Ryou; Sakon, Itsuki; Matsuura, Mikako; Kaneda, Hidehiro

    2016-01-01

    Near-infrared (2.5-5.0$\\,\\mu$m) low-resolution ($\\lambda/\\Delta\\lambda{\\sim}100$) spectra of 72 Galactic planetary nebulae (PNe) were obtained with the Infrared Camera (IRC) in the post-helium phase. The IRC, equipped with a $1'{\\times}1'$ window for spectroscopy of a point source, was capable of obtaining near-infrared spectra in a slit-less mode without any flux loss due to a slit. The spectra show emission features including hydrogen recombination lines and the 3.3-3.5$\\,\\mu$m hydrocarbon features. The intensity and equivalent width of the emission features were measured by spectral fitting. We made a catalog providing unique information on the investigation of the near-infrared emission of PNe. In this paper, details of the observations and characteristics of the catalog are described.

  1. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Elżbieta Pociask

    2016-01-01

    Full Text Available Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement, segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects.

  2. Fast determination of the resin and rubber content in Parthenium argentatum biomass using near infrared spectroscopy

    NARCIS (Netherlands)

    Suchat, S.; Pioch, D.; Palu, S.; Tardan, E.; Loo, van E.N.; Davrieux, F.

    2013-01-01

    Guayule (Parthenium argentatum), a plant native of semi-arid regions of northern Mexico and southern Texas, United States, is an under-used source of hypoallergenic latex, a solution to the serious latex allergy IgE problem worldwide. This study aimed to develop near infrared spectroscopy (NIRS) cal

  3. IMPROVING THE QUALITY OF NEAR-INFRARED IMAGING OF IN VIVOBLOOD VESSELS USING IMAGE FUSION METHODS

    DEFF Research Database (Denmark)

    Jensen, Andreas Kryger; Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2009-01-01

    We investigate methods for improving the visual quality of in vivo images of blood vessels in the human forearm. Using a near-infrared light source and a dual CCD chip camera system capable of capturing images at visual and nearinfrared spectra, we evaluate three fusion methods in terms of their ...

  4. Fast determination of the resin and rubber content in Parthenium argentatum biomass using near infrared spectroscopy

    NARCIS (Netherlands)

    Suchat, S.; Pioch, D.; Palu, S.; Tardan, E.; Loo, van E.N.; Davrieux, F.

    2013-01-01

    Guayule (Parthenium argentatum), a plant native of semi-arid regions of northern Mexico and southern Texas, United States, is an under-used source of hypoallergenic latex, a solution to the serious latex allergy IgE problem worldwide. This study aimed to develop near infrared spectroscopy (NIRS)

  5. Possible near-infrared counterpart to the Galactic transient 1RXH J173523.7-354013

    NARCIS (Netherlands)

    E.M. Cackett; R. Wijnands; M. Reynolds

    2008-01-01

    Following the recent announcement of an X-ray and optical outburst from a previously unknown Galactic transient possibly associated with 1RXH J173523.7-354013 (Israel et al. 2008, ATel #1528) we obtained near-infrared observations of the source using the PANIC camera on the 6.5-m Magellan Baade tele

  6. Deep near-infrared survey of the Southern Sky (DENIS)

    Science.gov (United States)

    Deul, E.

    1992-01-01

    DENIS (Deep Near-Infrared Survey of the Southern Sky) will be the first complete census of astronomical sources in the near-infrared spectral range. The challenges of this novel survey are both scientific and technical. Phenomena radiating in the near-infrared range from brown dwarfs to galaxies in the early stages of cosmological evolution, the scientific exploitation of data relevant over such a wide range requires pooling expertise from several of the leading European astronomical centers. The technical challenges of a project which will provide an order of magnitude more sources than given by the IRAS space mission, and which will involve advanced data-handling and image-processing techniques, likewise require pooling of hardware and software resources, as well as of human expertise. The DENIS project team is composed of some 40 scientists, computer specialists, and engineers located in 5 European Community countries (France, Germany, Italy, The Netherlands, and Spain), with important contributions from specialists in Australia, Brazil, Chile, and Hungary. DENIS will survey the entire southern sky in 3 colors, namely in the I band at a wavelength of 0.8 micron, in the 1.25 micron J band, and in the 2.15 micron K' band. The sensitivity limits will be 18th magnitude in the I band, 16th in the J band, and 14.5th in the K' band. The angular resolution achieved will be 1 arcsecond in the I band, and 3.0 arcseconds in the J and K' bands. The European Southern Observatory 1 m telescope on La Silla will be dedicated to survey use during operations expected to last four years, commencing in late 1993. DENIS aims to provide the astronomical community with complete digitized infrared images of the full southern sky and a catalogue of extracted objects, both of the best quality and in readily accessible form. This will be achieved through dedicated software packages and specialized catalogues, and with assistance from the Leiden and Paris Data Analysis Centers. The data

  7. [Drug release system controlled by near infrared light].

    Science.gov (United States)

    Niidome, Takuro

    2013-01-01

    Gold nanorods have absorption bands in the near-infrared region; in this spectral range, light penetrates deeply into tissues. The absorbed light energy is converted into heat by gold nanorods. This is the so-called photothermal effect. Gold nanorods are therefore expected to act not only as thermal converters for photothermal therapy, but also as controllers for drug-release systems responding to irradiation with near-infrared light. To achieve a controlled-release system that could be triggered by light irradiation, the gold nanorods were modified with double-stranded DNA (dsDNA). When the dsDNA-modified gold nanorods were irradiated with near-infrared light, single-stranded DNA (ssDNA) was released from the gold nanorods because of the photothermal effect. The release of ssDNA was also observed in tumors grown on mice after near-infrared light irradiation. We also proposed a different controlled-release system responding to near-infrared light. Gold nanorods were modified with polyethylene glycol (PEG) through Diels-Alder cycloadducts. When the gold nanorods were irradiated with near-infrared light, the PEG chains were released from the gold nanorods because of the retro Diels-Alder reaction induced by the photothermal effect. Such controlled-release systems triggered by near-infrared light irradiation will be expanded for gold nanorod drug delivery system applications.

  8. Advances in Organic Near-Infrared Materials and Emerging Applications.

    Science.gov (United States)

    Qi, Ji; Qiao, Wenqiang; Wang, Zhi Yuan

    2016-06-01

    Much progress has been made in the field of research on organic near-infrared materials for potential applications in photonics, communications, energy, and biophotonics. This account mainly describes our research work on organic near-infrared materials; in particular, donor-acceptor small molecules, organometallics, and donor-acceptor polymers with the bandgaps less than 1.2 eV. The molecular designs, structure-property relationships, unique near-infrared absorption, emission and color/wavelength-changing properties, and some emerging applications are discussed.

  9. Subaru Deep Survey I. Near-Infrared Observations

    CERN Document Server

    Maihara, T; Tanabe, H; Taguchi, T; Hata, R; Oya, S; Kashikawa, N; Iye, M; Miyazaki, S; Karoji, H; Yoshida, M; Totani, T; Yoshii, Y; Okamura, S; Shimasaku, K; Saitô, Y; Ando, H; Goto, M; Hayashi, M; Kaifu, N; Kobayashi, N; Kosugi, G; Motohara, K; Nishimura, T; Noumaru, J; Ogasawara, R; Sasaki, T; Sekiguchi, K; Takata, T; Terada, H; Yamashita, T; Usuda, T; Tokunaga, A T

    2000-01-01

    Deep near-infrared images of a blank 2'x2' section of sky near the Galactic north pole taken by Subaru Telescope are presented. The total integration times of the J and K' bands are 12.1 hours and 9.7 hours, resulting in 5-sigma limiting magnitudes of 25.1 and 23.5 mag, respectively. The numbers of sources within these limiting magnitudes found with an automated detection procedure are 385 in the J band and 350 in K'. Based on photometric measurements of these sources, we present number count vs. magnitude relations, color vs. magnitude diagrams, size vs. color relationships, etc. The slope of the galaxy number count plotted against the AB magnitude scale is about 0.23 in the 22 to 26 AB magnitude range of both bands. The spatial number density of galaxies as well as the slopes in the faint-end region given by the Subaru Deep Field (SDF) survey is consistent with those given by HST-NICMOS surveys as expressed on the AB magnitude diagram. Several sources having very large J-K' color are found including a few K...

  10. Resolved Near-Infrared Stellar Populations in Nearby Galaxies

    CERN Document Server

    Dalcanton, Julianne J; Melbourne, Jason L; Girardi, Léo; Dolphin, Andy; Rosenfield, Philip A; Boyer, Martha L; de Jong, Roelof S; Gilbert, Karoline; Marigo, Paola; Olsen, Knut; Seth, Anil C; Skillman, Evan

    2011-01-01

    We present near-infrared (NIR) color-magnitude diagrams (CMDs) for the resolved stellar populations within 26 fields of 23 nearby galaxies (<4 Mpc), based on F110W and F160W images from Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). The CMDs sample both old dormant and young star-forming populations. We match key NIR CMD features with their counterparts in optical CMDs, and identify the red core Helium burning (RHeB) sequence as a significant contributor to the NIR flux in stellar populations younger than a few 100 Myrs old, suggesting that star formation can drive surprisingly rapid variations in the NIR mass-to-light ratio. The NIR luminosity of star forming galaxies is therefore not necessarily proportional to the stellar mass. We note that these individual bright RHeB stars may be misidentified as old stellar clusters in low resolution imaging. We also discuss the CMD location of asymptotic giant branch (AGB) stars, and the separation of AGB sub-populations using a combination of optic...

  11. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas

    2015-01-01

    OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care units...

  12. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas;

    2015-01-01

    OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care units...

  13. Nano-plasmonic antennas in the near infrared regime.

    Science.gov (United States)

    Berkovitch, N; Ginzburg, P; Orenstein, M

    2012-02-22

    Plasmonic nano-antennas constitute a central research topic in current science and engineering with an enormous variety of potential applications. Here we review the recent progress in the niche of plasmonic nano-antennas operating in the near infrared part of the spectrum which is important for a variety of applications. Tuning of the resonance into the near infrared regime is emphasized in the perspectives of fabrication, measurement, modeling, and analytical treatments, concentrating on the vast recent achievements in these areas.

  14. Near-infrared branding efficiently correlates light and electron microscopy.

    Science.gov (United States)

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  15. Near-infrared absorption fiber-optic sensors for ultra-sensitive CO2 detection

    Science.gov (United States)

    Chong, Xinyuan; Kim, Ki-Joong; Ohodnicki, Paul R.; Chang, Chih-Hung; Wang, Alan X.

    2015-05-01

    We present a fiber-optic sensor working at near-infrared (NIR) wavelength (~1.57μm) for CO2 detection. In order to increase the NIR absorption, we utilize functional sensor materials metalorganic framework (MOF) on the surface of the core of a multimode-fiber with the cladding layer etched away. The selected functional materials demonstrated excellent adsorption capacity of CO2 and significantly increased the detection sensitivity down to 500 ppm with only 8-centimeter absorption length.

  16. Anthracene-fused BODIPYs as near-infrared dyes with high photostability

    KAUST Repository

    Zeng, Lintao

    2011-11-18

    An anthracene unit was successfully fused to the zigzag edge of a boron dipyrromethene (BODIPY) core by an FeCl 3-mediated oxidative cyclodehydrogenation reaction. Meanwhile, a dimer was also formed by both intramolecular cyclization and intermolecular coupling. The anthracene-fused BODIPY monomer 7a and dimer 7b showed small energy gaps (∼1.4 eV) and near-infrared absorption/emission. Moreover, they exhibited high photostability. © 2011 American Chemical Society.

  17. Internal Extinction in Spiral Galaxies in the Near Infrared

    CERN Document Server

    Masters, K L; Haynes, M P; Masters, Karen L.; Giovanelli, Riccardo; Haynes, Martha P.

    2003-01-01

    In order to study the effects of internal extinction in spiral galaxies we search for correlations of near infrared (NIR) photometric parameters with inclination. We use data from the 2 Micron All-Sky Survey (2MASS) Extended Source Catalog (XSC) on 15,224 spiral galaxies for which we also have redshifts. For 3035 of the galaxies, I-band photometry is available which is included in the analysis. From the simple dependence of reddening on inclination we derive a lower limit to the difference in magnitude between the face-on and edge-on aspect of 0.9, 0.3 and 0.1 magnitudes in I (0.81 um), J (1.25 um) and H (1.65 um) bands. We find that the faintest isophotal radius reported in the XSC (at the 21st mag/arc sq level) is closer to the centers of the galaxies than other common isophotal measures (e.g. the 23.5 mag/arc sq radius in I-band), and argue that it should not be assumed to represent an outer isophote at which galaxies are transparent at all viewing angles. A simple linear extinction law (i.e. Delta M = gam...

  18. Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars

    DEFF Research Database (Denmark)

    Jiang, Linhua; Fan, Xiaohui; Vestergaard, Marianne

    2007-01-01

    We present Gemini near-infrared spectroscopic observations of six luminous quasars at z=5.8$\\sim$6.3. Five of them were observed using Gemini-South/GNIRS, which provides a simultaneous wavelength coverage of 0.9--2.5 $\\mu$m in cross dispersion mode. The other source was observed in K band...... with Gemini-North/NIRI. We calculate line strengths for all detected emission lines and use their ratios to estimate gas metallicity in the broad-line regions of the quasars. The metallicity is found to be supersolar with a typical value of $\\sim$4 Z_{\\sun}, and a comparison with low-redshift observations...... shows no strong evolution in metallicity up to z$\\sim$6. The FeII/MgII ratio of the quasars is 4.9+/-1.4, consistent with low-redshift measurements. We estimate central BH masses of 10^9 to 10^{10} M_{\\sun} and Eddington luminosity ratios of order unity. We identify two MgII $\\lambda\\lambda$2796...

  19. A novel storage method for near infrared spectroscopy chemometric models.

    Science.gov (United States)

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

    2010-06-04

    Chemometric Modeling Markup Language (CMML) is developed by us for containing chemometrics models within one document through converting binary data into strings by base64 encode/decode algorithms to solve the interoperability issue in sharing chemometrics models. It provides a base functionality for storage of sampling, variable selection, pretreating, outlier and modeling parameters and data. With the help of base64 algorithm, the usability of CMML is in equilibrium with size by transforming the binary data into base64 encoded string. Due to the advantages of Extensible Markup Language (XML), models stored in CMML can be easily reused in various other software and programming languages as long as the programming language has XML parsing library. One can also use the XML Path Language (XPath) query language to select desired data from the CMML file effectively. The application of this language in near infrared spectroscopy model storage is implemented as a class in C++ language and available as open source software (http://code.google.com/p/cmml), and the implementations in other languages, such as MATLAB and R are in progress.

  20. LED-based near infrared sensor for cancer diagnostics

    Science.gov (United States)

    Bogomolov, Andrey; Ageev, Vladimir; Zabarylo, Urszula; Usenov, Iskander; Schulte, Franziska; Kirsanov, Dmitry; Belikova, Valeria; Minet, Olaf; Feliksberger, E.; Meshkovsky, I.; Artyushenko, Viacheslav

    2016-03-01

    Optical spectroscopic technologies are increasingly used for cancer diagnostics. Feasibility of differentiation between malignant and healthy samples of human kidney using Fluorescence, Raman, MIR and NIR spectroscopy has been recently reported . In the present work, a simplification of NIR spectroscopy method has been studied. Traditional high-resolution NIR spectrometry was replaced by an optical sensor based on a set of light-emitting diodes at selected wavelengths as light sources and a photodiode. Two prototypes of the sensor have been developed and tested using 14 in-vitro samples of seven kidney tumor patients. Statistical evaluation of results using principal component analysis and partial least-squares discriminant analysis has been performed. Despite only partial discrimination between tumor and healthy tissue achieved by the presented new technique, the results evidence benefits of LED-based near-infrared sensing used for oncological diagnostics. Publisher's Note: This paper, originally published on 4 March, 2016, was replaced with a corrected/revised version on 7 April, 2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  1. Novel near infrared sensors for hybrid BCI applications

    Science.gov (United States)

    Almajidy, Rand K.; Le, Khang S.; Hofmann, Ulrich G.

    2015-07-01

    This study's goal is to develop a low cost, portable, accurate and comfortable NIRS module that can be used simultaneously with EEG in a dual modality system for brain computer interface (BCI). The sensing modules consist of electroencephalography (EEG) electrodes (at the positions Fp1, Fpz and Fp2 in the international 10-20 system) with eight custom made functional near infrared spectroscopy (fNIRS) channels, positioned on the prefrontal cortex area with two extra channels to measure and eliminate extra-cranial oxygenation. The NIRS sensors were designed to guarantee good sensor-skin contact, without causing subject discomfort, using springs to press them to the skin instead of pressing them by cap fixture. Two open source software packages were modified to carry out dual modality hybrid BCI experiments. The experimental paradigm consisted of a mental task (arithmetic task or text reading) and a resting period. Both oxygenated hemoglobin concentration changes (HbO), and EEG signals showed an increase during the mental task, but the onset, period and amount of that increase depends on each modality's characteristics. The subject's degree of attention played an important role especially during online sessions. The sensors can be easily used to acquire brain signals from different cerebral cortex parts. The system serves as a simple technological test bed and will be used for stroke patient rehabilitation purposes.

  2. Near-infrared imaging survey of faint companions around young dwarfs in the Pleiades cluster

    Institute of Scientific and Technical Information of China (English)

    Yoichi Itoh; Yumiko Oasa; Hitoshi Funayama; Masahiko Hayashi; Misato Fukagawa; Toshio Hashiguchi; Thayne Currie

    2011-01-01

    We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the Subaru Telescope and the near-infrared coronagraph imager.We found ten faint point sources, with magnitudes as faint as 20 mag in the K-band,with around seven dwarfs. Comparison with the Spitzer archive images revealed that a pair of the faint sources around V 1171 Tau is very red in infrared wavelengths, which indicates very low-mass young stellar objects. However, the results of our follow-up proper motion measurements implied that the central star and the faint sources do not share common proper motions, suggesting that they are not physically associated.

  3. Near-field thermal radiative emission of materials demonstrating near infrared surface polariton resonance

    Science.gov (United States)

    Petersen, Spencer Justin

    Surface polariton mediated near-field radiative transfer exceeds the blackbody limit by orders of magnitude and is quasimonochromatic. Thermophotovoltaic (TPV) power generation consists of converting thermal radiation into useful electrical energy and exhibits a peak performance near the TPV cell bandgap, which is typically located within the near infrared bandwidth. Therefore, an ideal emission source for a nanoscale gap TPV device, in which the emitter and cell are separated by no more than one peak emitted wavelength, will sustain surface polariton resonance at or near the TPV cell bandgap in the near infrared. To date, few materials have been identified that satisfy this requirement. The first objective of this dissertation is to theoretically explore dielectric Mie resonance-based (DMRB) electromagnetic metamaterials for the potential to sustain near infrared surface polariton resonance. Electromagnetic metamaterials are composite media, consisting of subwavelength, repeating unit structures called "meta-atoms." The microscopic configuration of the meta-atom can be engineered, dictating the effective macroscale electromagnetic properties of the bulk metamaterial, including the surface polariton resonance wavelength. DMRB metamaterials consist of dielectric nanoparticles within a host medium and are analyzed using an effective medium theory. The local density of electromagnetic states, an indicator of possibly harvestable energy near an emitting surface, is calculated for two DMRB metamaterials: spherical nanoparticles of 1) silicon carbide, and 2) silicon embedded in a host medium. Results show that the surface polariton resonance of these metamaterials is tunable and, for the silicon metamaterial only, is found in the near infrared bandwidth, making it a viable candidate for use in a nano-TPV device. In order to demonstrate the practicality thereof, the second objective is to fabricate and characterize DMRB metamaterials. Specimens are fabricated by hand

  4. New and Better Near-Infrared Detectors for JWST Near Infrared Spectrograph

    Science.gov (United States)

    Rauscher, Bernard J.; Mott, D. Brent; Wen, Yiting; Linder, Don; Greenhouse, Matthew A.; Hill, Robert J.

    2014-01-01

    ESA and NASA recently selected two 5 m cutoff Teledyne H2RG sensor chip assemblies (SCA) for flight on the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These HgCdTe SCAs incorporate Teledynes improved barrier layer design that eliminates the degradation that affected earlier JWST H2RGs(Rauscher et al. 2012a). The better indium barrier, together with other design changes, has improved the performance and reliability of JWSTs SCAs. In this article, we describe the measured performance characteristics that most directly affect scientific observations including read noise, total noise, dark current, quantum efficiency (QE), and image persistence. As part of measuring QE, we measured the quantum yield as a function of photon energy,, and found that it exceeds unity for photon energies E (2.65.2) Eg, where Eg is the HgCdTe bandgap energy. This corresponds to. 2 m for NIRSpecs 5 m cutoff HgCdTe. Our measurements agree well with a previous measurement by McCullough et al. (2008) for. 1.3. For 1.3, we find a slower increase in with photon energy than McCullough et al. did. However, and as McCullough et al. note, their two state model of the yield process is not valid for large 1.

  5. Near-infrared surface-enhanced Raman spectroscopy of chemisorbed compounds on gold colloids

    Science.gov (United States)

    Xu, Hong; Tseng, Ching-Hui; Vickers, Thomas J.; Mann, Charles K.; Schlenoff, Joseph B.

    1994-05-01

    Near-infrared surface-enhanced Raman scattering (SERS) spectra have been measured for strongly chemisorbed compounds, such as 4-mercaptopyridine and thiophenol, on gold colloids in mixed solvents of ethanol and water using a diode laser as an excitation source. From UV-vis spectroscopy, the aggregated gold colloids show a broad absorbance band through the visible to the near-infrared after adding chemisorbing compounds. The absorption maximum is located in the range 750-850 nm, permitting the use of a near-IR source (826 nm) for the first time in SERS of gold colloid systems. The estimated enhancement is on the order of 10 5. Transmission electron microscopy of aggregated gold particles revealed a cluster morphology. The aggregated mixed-solvent colloids were more stable than those prepared in water, and were useful in dissolving compounds with poor water solubility.

  6. Near infrared reflectance analysis by Gauss-Jordan linear algebra

    Science.gov (United States)

    Honigs, D. E.; Freelin, J. M.; Hieftje, G. M.

    1983-02-01

    Near-infrared reflectance analysis (NIRA) is an analytical technique that uses the near-infrared diffuse reflectance of a sample at several discrete wavelengths to predict the concentration of one or more of the chemical species in that sample. However, because near-infrared bands from solid samples are both abundant and broad, the reflectance at a given wavelength usually contains contributions from several sample components, requiring extensive calculations on overlapped bands. In the present study, these calculations have been performed using an approach similar to that employed in multi-component spectrophotometry, but with Gauss-Jordan linear algebra serving as the computational vehicle. Using this approach, correlations for percent protein in wheat flour and percent benzene in hydrocarbons have been obtained and are evaluated. The advantages of a linear-algebra approach over the common one employing stepwise regression are explored.

  7. A near-infrared SETI experiment: instrument overview

    CERN Document Server

    Wright, Shelley A; Treffers, Richard R; Maire, Jerome; Marcy, Geoffrey W; Stone, Remington P S; Drake, Frank; Meyer, Elliot; Dorval, Patrick; Siemion, Andrew

    2014-01-01

    We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design builds upon our past optical SETI experiences, and is the first step toward a new, more versatile and sophisticated generation of very fast optical and near-infrared pulse search devices. We present our instrumental design by giving an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. This project makes use of near-infrared (950-1650 nm) discrete amplification Avalanche Photodiodes (APD) that have greater than 1 GHz bandwidths with low noise characteristics and moderate gain (~10^4). We have investigated the use of single versus multiple detectors in our instrument (see Maire et al., this conference), and have optimized the system to have both high sensitivity and low false coincidence rates. Our ...

  8. New applications of near infrared spectroscopy in the food industry

    Energy Technology Data Exchange (ETDEWEB)

    Groenewald, C.A. (Peter Rassloff Instruments and Services, Norwood, South Africa)

    The near infrared spectroscopic method of analysis was initially developed for rapid analyses of protein in wheat. A brief explanation of the theory and history of near infrared spectroscopic analysis will be given. Research was done on the application of near infrared spectroscopic (NIR) in the food industry. Especially exciting was the breakthrough achieved in applying NIR to determine the dry solid content of bread. Such application could revolutionise the baking industry. Results will also be presented of research done on the application of NIR techniques for the determination of protein and fat in bread based on dry matter; hardness in wheat; absorption and sedimentation in pasta products; and use in process control in snack products manufacture. The limitations that were found in the application of NIR analysis will also be covered. The developments in NIR technology may result in these methods becoming standard practice in many food laboratories.

  9. Raman crystal lasers in the visible and near-infrared

    Institute of Scientific and Technical Information of China (English)

    EICHLERH.J.; GADG.M.A.; KAMINSKIIA.A.; RHEEH.

    2003-01-01

    Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064/μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15 - 1.32/μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.

  10. Raman crystal lasers in the visible and near-infrared

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064 μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15-1.32 μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.

  11. Near-Infrared Observations of Compact Binary Systems

    Science.gov (United States)

    Khargharia, Juthika

    Low mass X-ray binaries (LMXBs) are a subset of compact binary systems in which a main-sequence or slightly evolved star fills its Roche lobe and donates mass to a neutron star or a black hole (BH) via an accretion disk. Robust estimates of compact object masses in these systems are required to enhance our current understanding of the physics of compact object formation, accretion disks and jets. Compact object masses are typically determined at near-infrared (NIR) wavelengths when the system is in quiescence and the donor star is the dominant source of flux. Previous studies have assumed that any non-stellar contribution at these wavelengths is minimal. However, this assumption is rarely true. By performing NIR spectroscopy, we determined the fractional donor star contribution to the NIR flux and the compact object masses in two LMXBs: V404 Cyg and Cen X-4. In our analysis, it was assumed that the light curve morphology remains consistent throughout quiescence. It has now been shown in several systems that veiling measurements from non-stellar sources are meaningful only if acquired contemporaneously with light curve measurements. We accounted for this in the measurement of the BH mass in the LMXB, XTE J1118+480. LMXBs are also considered to be the most likely candidates responsible for the formation of milli-second pulsars (MSP). Here, I present the unique case of PSR J1903+0327 that challenges this currently accepted theory of MSP formation and is a potential candidate for testing General Relativity. Observations in the NIR come with their own set of challenges. NIR detector arrays used in these observations generally have high dark current and readout noise. In an effort to lower the read noise in NICFPS at APO, we present a study done on the Hawaii-1RG engineering grade chip that served as a test bed for reducing the read noise in NICFPS.

  12. Application of near-infrared reflectance spectrometry to the analytical control of pharmaceuticals: ranitidine hydrochloride tablet production.

    Science.gov (United States)

    Dreassi, E; Ceramelli, G; Corti, P; Perruccio, P L; Lonardi, S

    1996-02-01

    The possibility of applying near-infrared reflectance spectrometry to the control of the production cycle of ranitidine hydrochloride tablets was investigated. The results were good for the identification of ranitidine hydrochloride drug substance, mixtures for tablets, cores and coated tablets. The determination of the compound and of its water content also gave satisfactory results.

  13. Near-infrared operating lamp for intraoperative molecular imaging of a mediastinal tumor

    OpenAIRE

    2016-01-01

    Background Near-Infrared (NIR) intraoperative molecular imaging is a new diagnostic modality utilized during cancer surgery for the identification of tumors, metastases and lymph nodes. Surgeons typically use headlamps during an operation to increase visible light; however, these light sources are not adapted to function simultaneously with NIR molecular imaging technology. Here, we design a NIR cancelling headlamp and utilize it during surgery to assess whether intraoperative molecular imagi...

  14. Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials

    Science.gov (United States)

    Wolf, Omri; Allerman, Andrew A.; Ma, Xuedan; Wendt, Joel R.; Song, Alex Y.; Shaner, Eric A.; Brener, Igal

    2015-10-01

    We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena.

  15. Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Omri, E-mail: owolf@sandia.gov, E-mail: ibrener@sandia.gov; Ma, Xuedan; Brener, Igal, E-mail: owolf@sandia.gov, E-mail: ibrener@sandia.gov [Center for Integrated Nanotechnologies, Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Allerman, Andrew A.; Wendt, Joel R.; Shaner, Eric A. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Song, Alex Y. [Electrical Engineering Department, Princeton University, EQuad, Olden St, Princeton, New Jersy 08540 (United States)

    2015-10-12

    We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena.

  16. Near-infrared spectroscopy during peripheral vascular surgery

    DEFF Research Database (Denmark)

    Eiberg, J P; Schroeder, T V; Vogt, K C;

    1997-01-01

    Near-infrared spectroscopy was performed perioperatively on the dorsum of the foot in 14 patients who underwent infrainguinal bypass surgery using a prosthesis or the greater saphenous vein. Dual-wavelength continuous light spectroscopy was used to assess changes in tissue saturation before, during...... and after the operation. Following the use of peripheral vascular grafts an immediate postoperative increase in tissue saturation of median 28 (range -10 to +81) arbitrary units was noted (P ... that near-infrared spectroscopy is appropriate for perioperative monitoring during vascular grafting....

  17. Near-infrared face recognition utilizing open CV software

    Science.gov (United States)

    Sellami, Louiza; Ngo, Hau; Fowler, Chris J.; Kearney, Liam M.

    2014-06-01

    Commercially available hardware, freely available algorithms, and authors' developed software are synergized successfully to detect and recognize subjects in an environment without visible light. This project integrates three major components: an illumination device operating in near infrared (NIR) spectrum, a NIR capable camera and a software algorithm capable of performing image manipulation, facial detection and recognition. Focusing our efforts in the near infrared spectrum allows the low budget system to operate covertly while still allowing for accurate face recognition. In doing so a valuable function has been developed which presents potential benefits in future civilian and military security and surveillance operations.

  18. Breast phantom for mammary tissue characterization by near infrared spectroscopy

    Science.gov (United States)

    Miranda, D. A.; Cristiano, K. L.; Gutiérrez, J. C.

    2013-11-01

    Breast cancer is a disease associated to a high morbidity and mortality in the entire world. In the study of early detection of breast cancer the development of phantom is so important. In this research we fabricate a breast phantom using a ballistic gel with special modifications to simulate a normal and abnormal human breast. Optical properties of woman breast in the near infrared region were modelled with the phantom we developed. The developed phantom was evaluated with near infrared spectroscopy in order to study its relation with breast tissue. A good optical behaviour was achieved with the model fabricated.

  19. Near-Infrared Properties of Type Ia Supernovae

    Science.gov (United States)

    Phillips, M. M.

    2012-02-01

    The photometric properties of Type Ia supernovae (SNe Ia) in the near-infrared as garnered from observations made over the last 30 years are reviewed. During this period, light curves for more than 120 nearby SNe Ia have been published, revealing considerable homogeneity but also some fascinating differences. These data have confirmed that, for all but the fastest declining objects, SNe Ia are essentially perfect standard candles in the near-infrared, displaying only a slight dependence of peak luminosity on decline rate and color.

  20. A Near-Infrared Imaging Survey of Coalsack Globule 2

    OpenAIRE

    Racca, German; Gomez, Mercedes; Kenyon, Scott J.

    2002-01-01

    We describe a near-infrared imaging survey of Globule 2 in the Coalsack. This Bok globule is the highest density region of this southern hemisphere molecular cloud and is the most likely location for young stars in this complex. The survey is complete for K < 14.0, H < 14.5, and J < 15.5, several magnitudes more sensitive than previous observations of this globule. From the large number of background stars, we derive an accurate near-infrared extinction law for the cloud. Our result, E_{J-H}/...

  1. Nanostructures graphene plasmon works close to near-infrared window

    DEFF Research Database (Denmark)

    Wang, Zhongli; Li, Tao; Almdal, Kristoffer

    concepts with existing mature technologies in the near-infrared region. We investigate localized graphene plasmons supported by graphene nanodisks and experimentally demonstrated graphene plasmon working at 2 μm with the aid of a fully scalable block copolymer selfassembly method. Our results show......Due to strong mode-confinement, long propagation-distance, and unique tunability, graphene plasmons have been widely explored in the mid-infrared and terahertz windows. However, it remains a big challenge to push graphene plasmons to shorter wavelengths in order to integrate graphene plasmon...... a promising way to promote graphene plasmons for both fundamental studies and potential applications in the near-infrared window....

  2. Near-infrared Mueller matrix imaging for colonic cancer detection

    Science.gov (United States)

    Wang, Jianfeng; Zheng, Wei; Lin, Kan; Huang, Zhiwei

    2016-03-01

    Mueller matrix imaging along with polar decomposition method was employed for the colonic cancer detection by polarized light in the near-infrared spectral range (700-1100 nm). A high-speed (colonic tissues (i.e., normal and caner) were acquired. Polar decomposition was further implemented on the 16 images to derive the diattentuation, depolarization, and the retardance images. The decomposed images showed clear margin between the normal and cancerous colon tissue samples. The work shows the potential of near-infrared Mueller matrix imaging for the early diagnosis and detection of malignant lesions in the colon.

  3. Steps Toward a Common Near-Infrared Photometric System

    CERN Document Server

    Tokunaga, A T

    2007-01-01

    The proliferation of near-infrared (1--5 $\\mu$m) photometric systems over the last 30 years has made the comparison of photometric results difficult. In an effort to standardize infrared filters in use, the Mauna Kea Observatories near-infrared filter set has been promoted among instrument groups through combined filter production runs. The characteristics of this filter set are summarized, and some aspects of the filter wavelength definitions, the flux density for zero magnitude, atmospheric extinction coefficients, and color correction to above the atmosphere are discussed.

  4. NEWS: the near-infrared Echelle for wideband spectroscopy

    Science.gov (United States)

    Veyette, Mark J.; Muirhead, Philip S.; Hall, Zachary J.; Taylor, Brian; Ye, Jimmy

    2016-08-01

    We present an updated optical and mechanical design of NEWS: the Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the High-resolution J, H and K spectrometer), a compact, high-resolution, near-infrared spectrometer for 5-meter class telescopes. NEWS provides a spectral resolution of 60,000 and covers the full 0.8-2.5 μm range in 5 modes. We adopt a compact, lightweight, monolithic design and have developed NEWS to be mounted to the instrument cube at the Cassegrain focus of the new 4.3-meter Discovery Channel Telescope.

  5. NEWS: the near-infrared Echelle for wideband spectroscopy

    CERN Document Server

    Veyette, Mark; Hall, Zachary; Taylor, Brian; Ye, Jimmy

    2016-01-01

    We present an updated optical and mechanical design of NEWS: the Near-infrared Echelle for Wide-band Spectroscopy (formerly called HiJaK: the High-resolution J, H and K spectrometer), a compact, high-resolution, near-infrared spectrometer for 5-meter class telescopes. NEWS provides a spectral resolution of 60,000 and covers the full 0.8-2.5 micron range in 5 modes. We adopt a compact, lightweight, monolithic design and developed NEWS to be mounted to the instrument cube at the Cassegrain focus of the the new 4.3-meter Discovery Channel Telescope.

  6. Near-infrared calibration systems for precise radial-velocity measurements

    Science.gov (United States)

    Redman, Stephen L.; Kerber, Florian; Nave, Gillian; Mahadevan, Suvrath; Ramsey, Lawrence W.; Smoker, Jonathan; Käufl, Hans-Ulrich; Figueira, P. R. L.

    2012-09-01

    We present work done to prepare two new near-infrared calibration sources for use on high-precision astrophysical spectrographs. Uranium-neon is an atomic calibration source, commercially available as a hollow-cathode lamp, with over 10 000 known emission lines between 0.85 and 4 μm. Four gas cells — containing C2H2, H13CN, 12CO, and 13CO, respectively—are available as National Institute of Standards and Technology (nist) Standard Reference Materials (SRMs), and provide narrow absorption lines between 1.5 and 1.65 μm. These calibration sources may prove useful for wavelength-calibrating the future near-infrared high-precision radial-velocity spectrometers, including the Calar Alto high-Resolution search for M dwarfs with Exo-earths with a Near-infrared Echelle Spectrograph (CARMENES),1 the SpectroPolarimetre InfraROUge (SPIRou)∗, and the Habitable-Zone Planet Finder (HPF).2

  7. Number Density Distribution of Near-Infrared Sources on a Sub-Degree Scale in the Galactic Center: Comparison with the Fe XXV Ka Line at 6.7 keV

    CERN Document Server

    Yasui, Kazuki; Yoshikawa, Tatsuhito; Nagatomo, Schun; Uchiyama, Hideki; Tsuru, Takeshi G; Koyama, Katsuji; Tamura, Motohide; Kwon, Jungmi; Sugitani, Koji; Schödel, Rainer; Nagata, Tetsuya

    2015-01-01

    The stellar distribution derived from an $H$ and $K_{\\mathrm S}$-band survey of the central region of our Galaxy is compared with the Fe XXV K$\\alpha$ (6.7 keV) line intensity observed with the Suzaku satellite. The survey is for the Galactic coordinates $|l| \\lesssim 3^{\\circ}.0$ and $|b| \\lesssim 1^{\\circ}.0$ (equivalent to 0.8 kpc $\\times$ 0.3 kpc for $R_0 = 8$ kpc), and the number-density distribution $N(K_{\\mathrm S,0}; l, b)$ of stars is derived using the extinction-corrected magnitude $K_{\\mathrm S,0}=10.5$. This is deep enough to probe the old red giant population and in turn to estimate the ($l$, $b$) distribution of faint X-ray point sources such as coronally active binaries and cataclysmic variables. In the Galactic plane ($b=0^{\\circ}$), $N(10.5; l, b)$ increases to the Galactic center as $|l|^{-0.30 \\pm 0.03}$ in the range of $-0^{\\circ}.1 \\geq l \\geq -0^{\\circ}.7$, but this increase is significantly slower than the increase ($|l|^{-0.44 \\pm 0.02}$ ) of the Fe XXV K$\\alpha$ line intensity. If nor...

  8. A near-infrared SETI experiment: probability distribution of false coincidences

    CERN Document Server

    Maire, Jérôme; Werthimer, Dan; Treffers, Richard R; Marcy, Geoffrey W; Stone, Remington P S; Drake, Frank; Siemion, Andrew

    2014-01-01

    A Search for Extraterrestrial Life (SETI), based on the possibility of interstellar communication via laser signals, is being designed to extend the search into the near-infrared spectral region (Wright et al, this conference). The dedicated near-infrared (900 to 1700 nm) instrument takes advantage of a new generation of avalanche photodiodes (APD), based on internal discrete amplification. These discrete APD (DAPD) detectors have a high speed response ($>$ 1 GHz) and gain comparable to photomultiplier tubes, while also achieving significantly lower noise than previous APDs. We are investigating the use of DAPD detectors in this new astronomical instrument for a SETI search and transient source observations. We investigated experimentally the advantages of using a multiple detector device operating in parallel to remove spurious signals. We present the detector characterization and performance of the instrument in terms of false positive detection rates both theoretically and empirically through lab measureme...

  9. COBE DIRBE near-infrared polarimetry of the zodiacal light: Initial results

    Science.gov (United States)

    Berriman, G. B.; Boggess, N. W.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    This Letter describes near-infrared polarimetry of the zodiacal light at 2.2 micrometers, measured with the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The polarization is due to scattering of sunlight. The polarization vector is perpendicular to the scattering plane, and its observed amplitude on the ecliptic equator at an elongation of 90 deg and ecliptic longitude of 10 deg declines from 12.0 +/- 0.4% at 1.25 micrometers to 8.0 +/- 0.6% at 3.5 micrometers (cf. 16% in the visible); the principal source of uncertainty is photometric noise due to stars. The observed near-infrared colors at this location are redder than Solar, but at 3.5 micrometers this is due at least in part to the thermal emission contribution from the interplanetary dust. Mie theory calculations show that both polarizations and colors are important in constraining models of interplanetary dust.

  10. Near Infrared Photoacoustic Detection of Heptane in Synthetic Air

    DEFF Research Database (Denmark)

    Duggen, Lars; Albu, Mihaela; Willatzen, Morten

    2013-01-01

    Trace contaminations of n-heptane in synthetic air is measured in the parts-per-billion (ppb) range using near infrared photoacoustic detection. We describe the fundamental theory used in the design of the photoacoustic cell for trace gas analysis and determine the detection limit of the cell...

  11. Electromagnetically induced transparency in metamaterials at near-infrared frequency

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Xiao, Sanshui; Jeppesen, Claus

    2010-01-01

    We employ a planar metamaterial structure composed of a splitring-resonator (SRR) and paired nano-rods to experimentally realize a spectral response at near-infrared frequencies resembling that of electromagnetically induced transparency. A narrow transparency window associated with low loss...

  12. X-Shooter Survey of Near-Infrared DIBs

    NARCIS (Netherlands)

    Cox, N.L.J.; Cami, J.; Kaper, L.; Foing, B.H.; Ehrenfreund, P.; Ochsendorf, B.B.; van Hooff, S.H.M.; Salama, F.

    2014-01-01

    We present the first results of an exploratory VLT/X-Shooter survey of near-infrared diffuse interstellar bands (DIBs) in diffuse to translucent interstellar clouds. These observations confirm the presence of recently discoved NIR DIBs and provide more accurate rest wavelengths and line widths.

  13. Near Infrared Photoacoustic Detection of Heptane in Synthetic Air

    DEFF Research Database (Denmark)

    Duggen, Lars; Albu, Mihaela; Willatzen, Morten

    2013-01-01

    Trace contaminations of n-heptane in synthetic air is measured in the parts-per-billion (ppb) range using near infrared photoacoustic detection. We describe the fundamental theory used in the design of the photoacoustic cell for trace gas analysis and determine the detection limit of the cell...

  14. Near infrared photoacoustic detection of heptane in synthetic air

    DEFF Research Database (Denmark)

    Duggen, Lars; Albu, Mihaela; Willatzen, Morten

    2013-01-01

    Trace contaminations of n-heptane in synthetic air is measured in the parts-per-billion (ppb) range using near infrared photoacoustic detection. We describe the fundamental theory used in the design of the photoacoustic cell for trace gas analysis and determine the detection limit of the cell...

  15. Spiral galaxy distance indicators based on near-infrared photometry

    NARCIS (Netherlands)

    Grijs, R. de; Peletier, R. F.

    1999-01-01

    We compare two methods of distance determination to spiral galaxies using optical/near-infrared (NIR) observations, the (I-K) versus M-K colour-absolute magnitude (CM) relation and the I- and K-band Tully-Fisher relation (TFR). Dust-free colours and NIR absolute magnitudes greatly enhance the

  16. Social Perception in Infancy: A Near Infrared Spectroscopy Study

    Science.gov (United States)

    Lloyd-Fox, Sarah; Blasi, Anna; Volein, Agnes; Everdell, Nick; Elwell, Claire E.; Johnson, Mark H.

    2009-01-01

    The capacity to engage and communicate in a social world is one of the defining characteristics of the human species. While the network of regions that compose the social brain have been the subject of extensive research in adults, there are limited techniques available for monitoring young infants. This study used near infrared spectroscopy to…

  17. Cotton micronaire measurements by small portable near infrared (nir) analyzers

    Science.gov (United States)

    A key quality and processing parameter for cotton fiber is micronaire, which is a function of the fiber’s maturity and fineness. Near Infrared (NIR) spectroscopy has previously shown the ability to measure micronaire, primarily in the laboratory and using large, research-grade laboratory NIR instru...

  18. Near-infrared transillumination photography of intraocular tumours.

    Science.gov (United States)

    Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

    2013-10-01

    To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

  19. ANALYSIS OF SWITCHGRASS CHARACTERISTICS USING NEAR INFRARED SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Nicole Labbé

    2008-11-01

    Full Text Available Switchgrass varieties grown under various environments were investi-gated by dispersive and Fourier Transform Near-Infrared (NIR spectro-meters. The collected NIR spectra were analyzed using multivariate approaches. More specifically, principal component analysis (PCA and projection to latent structures (PLS regression techniques were employed to classify and predict characteristics of the switchgrass samples. The multivariate results were compared to reflectance indices that are commonly used to study the physiological performance of plants. From near infrared spectra, discrimination between the two growth locations was successfully achieved by PCA. Separation based on the ecotype and the rate of fertilizer applied to the field was also possible by the multivariable analysis of the spectral data. For the classification/ discrimination of the switchgrass samples, the near infrared spectra collected by the dispersive and the Fourier Transform spectrometers provided similar results. From the two near infrared data sets robust models were developed to predict non-structural carbohydrates content and the rate of nitrogen applied to the field. However, the spectra collected by the dispersive spectrometer resulted in more accurate models for these samples.

  20. Gum Arabic authentication and mixture quantification by near infrared spectroscopy

    DEFF Research Database (Denmark)

    Dong, Yongjiang; Sørensen, Klavs Martin; He, Sailing

    2017-01-01

    A rapid and reliable method is developed for Gum Arabic authentication based on Near Infrared (NIR) spectroscopy and chemometric methods. On a large industrial collection of authentic gum Arabics, the two major Acacia gum species, Acacia senegal and Acacia seyal could be assigned perfectly...

  1. Near-infrared spectroscopy (NIRS) in a piglet model

    DEFF Research Database (Denmark)

    Clausen, Nicola Groes; Spielmann, Nelly; Ringer, Simone K.

    2017-01-01

    by Medtronic (Schweiz) AG - 3053 Münchenbuchsee | Switzerland. 1. Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS, et al. Cerebral oxygen desaturation events assessed by near-infrared spectroscopy during shoulder arthroscopy in the beach chair and lateral decubitus positions. Anesthesia...

  2. Near-infrared spectroscopy during peripheral vascular surgery

    DEFF Research Database (Denmark)

    Eiberg, J P; Schroeder, T V; Vogt, K C

    1997-01-01

    Near-infrared spectroscopy was performed perioperatively on the dorsum of the foot in 14 patients who underwent infrainguinal bypass surgery using a prosthesis or the greater saphenous vein. Dual-wavelength continuous light spectroscopy was used to assess changes in tissue saturation before, during...

  3. Social Perception in Infancy: A Near Infrared Spectroscopy Study

    Science.gov (United States)

    Lloyd-Fox, Sarah; Blasi, Anna; Volein, Agnes; Everdell, Nick; Elwell, Claire E.; Johnson, Mark H.

    2009-01-01

    The capacity to engage and communicate in a social world is one of the defining characteristics of the human species. While the network of regions that compose the social brain have been the subject of extensive research in adults, there are limited techniques available for monitoring young infants. This study used near infrared spectroscopy to…

  4. Discoveries from a Near-infrared Proper Motion Survey using Multi-epoch 2MASS Data

    CERN Document Server

    Kirkpatrick, J Davy; Burgasser, Adam J; Schurr, Steven D; Cutri, Roc M; Cushing, Michael C; Cruz, Kelle L; Sweet, Anne C; Knapp, Gillian R; Barman, Travis S; Bochanski, John J; Roellig, Thomas L; McLean, Ian S; McGovern, Mark R; Rice, Emily L

    2010-01-01

    We have conducted a 4030-square-deg near-infrared proper motion survey using multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find 2778 proper motion candidates, 647 of which are not listed in SIMBAD. After comparison to DSS images, we find that 107 of our proper motion candidates lack counterparts at B-, R-, and I-bands and are thus 2MASS-only detections. We present results of spectroscopic follow-up of 188 targets that include the infrared-only sources along with selected optical-counterpart sources with faint reduced proper motions or interesting colors. We also establish a set of near-infrared spectroscopic standards with which to anchor near-infrared classifications for our objects. Among the discoveries are six young field brown dwarfs, five "red L" dwarfs, three L-type subdwarfs, twelve M-type subdwarfs, eight "blue L" dwarfs, and several T dwarfs. We further refine the definitions of these exotic classes to aid future identification of similar objects. We examine their kinematics and fi...

  5. Discovery of Extremely Embedded X-ray Sources in the R Coronae Australis Star Forming Core

    CERN Document Server

    Hamaguchi, K; Petre, R; White, N E; Stelzer, B; Nedachi, K; Kobayashi, N; Tokunaga, A T; Hamaguchi, Kenji; Corcoran, Michael F.; Petre, Rob; White, Nicholas E.; Stelzer, Beate; Nedachi, Ko; Kobayashi, Naoto; Tokunaga, Alan T.

    2005-01-01

    With the XMM-Newton and Chandra observatories, we detected two extremely embedded X-ray sources in the R Corona Australis (R CrA) star forming core, near IRS 7. These sources, designated as XB and XA, have X-ray absorption columns of ~3e23 cm-2 equivalent to AV ~180 mag. They are associated with the VLA centimeter radio sources 10E and 10W, respectively. XA is the counterpart of the near-infrared source IRS 7, whereas XB has no K-band counterpart above 19.4 mag. This indicates that XB is younger than typical Class I protostars, probably a Class 0 protostar or in an intermediate phase between Class 0 and Class I. The X-ray luminosity of XB varied between 29

  6. Near-Infrared Observations of the Massive Star Forming Region IRAS 23151+5912

    Institute of Scientific and Technical Information of China (English)

    Xue-Peng Chen; Yong-Qiang Yao

    2004-01-01

    Near-infrared images and K-band spectroscopy of the massive starforming region IRAS 23151+5912 are presented.The JHK' images reveal an embedded infrared cluster associated with infrared nebula,and the H2(2.12μm)narrowband image provides for the first time evidence of outflow activity associated with the cluster.That the cluster is young can be shown by the high percentage of infrared excess sources and the outflow activity.We suggest an age of the cluster of ~ 106 yr.Eight young stars are found in the bright nebular core around IRAS 23151+5912.By the color-magnitude diagrams of the cluster,we found five high-mass YSOs and four intermediate-mass YSOs in the cluster.Eight H2 emission features are discovered in the region with a scattered and non-axisymmetric distribution,indicating the existence of multiple outflows driven by the cluster.Diffuse H2 emission detected to the north and to the west of the cluster may result from UV leakage of the cluster.Brγ,H2,and CIV emission lines are found in the K-band spectrum of the brightest source,NIRS 19,indicating the presence of envelope,stellar wind,and shock in the circumstellar environment.We have estimated an O7-O9spectral type for the central massive YSO(20 ~ 30M⊙),with an age of less than 1×106 yr.

  7. The water vapour continuum in near-infrared windows - Current understanding and prospects for its inclusion in spectroscopic databases

    Science.gov (United States)

    Shine, Keith P.; Campargue, Alain; Mondelain, Didier; McPheat, Robert A.; Ptashnik, Igor V.; Weidmann, Damien

    2016-09-01

    Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth's atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-infrared window regions (centred on 4700 and 6300 cm-1) and include reference to the window centred on 2600 cm-1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback - cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these windows. In individual windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-infrared windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum - as an example, we

  8. Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sabin, Guilherme P.; Breitkreitz, Marcia C.; Souza, Andre M. de [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Fonseca, Patricia da; Calefe, Lupercio; Moffa, Mario [Zelus Servicos para Industria Farmaceutica Ltda., Av. Professor Lineu Prestes n. 2242, Sao Paulo, SP (Brazil); Poppi, Ronei J., E-mail: ronei@iqm.unicamp.br [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

    2011-11-07

    Highlights: {yields} Near-Infrared Chemical Imaging was used for pellets analysis. {yields} Distribution of the components throughout the coatings layers and core of the pellets was estimated. {yields} Classical Least Squares (CLS) was used for calculation of the concentration maps. - Abstract: Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.

  9. Synthesis and properties of near infrared-absorbing magnetic-optical nanopins

    Science.gov (United States)

    Bhana, Saheel; Rai, Binod K.; Mishra, Sanjay R.; Wang, Yongmei; Huang, Xiaohua

    2012-07-01

    Novel near infrared-absorbing iron oxide-gold core-shell nanoparticles in pin shapes were synthesized. The nanopins are superparamagnetic, with 35-fold better surface enhanced Raman scattering activities than the conventional core-shell nanospheres and 50-fold greater photothermal properties than solid gold nanorods. The nanoparticles will have important impact on medical imaging, molecular diagnostics and disease treatment.Novel near infrared-absorbing iron oxide-gold core-shell nanoparticles in pin shapes were synthesized. The nanopins are superparamagnetic, with 35-fold better surface enhanced Raman scattering activities than the conventional core-shell nanospheres and 50-fold greater photothermal properties than solid gold nanorods. The nanoparticles will have important impact on medical imaging, molecular diagnostics and disease treatment. Electronic supplementary information (ESI) available: Experimental details, absorption spectrum of IO NPs, TEM images of IO-Ag seeds, TEM image and optical absorption spectra of IO-Au nanospheres. See DOI: 10.1039/c2nr31291c

  10. 近红外光镊技术结合脂质体膜相变用于硅-金核壳纳米粒子热效应的研究%Study on the Heating Profile of Silica-gold Core/shell Nanoparticles by Near-infrared Optical Tweezers and Lipid Vesicle Phase Transition

    Institute of Scientific and Technical Information of China (English)

    唐宏武

    2014-01-01

    通过测定近红外光镊捕获的单个硅-金核壳纳米粒子对荧光标记的脂质体膜加热产生的相变,建立了一种对纳米粒子的激光热效应的三维稳态测定方法.考察了介质温度和激光功率等因素对纳米粒子热效应的影响,并对硅-金核壳纳米粒子和纳米金的光热转换效率进行了比较,结果表明硅-金核壳纳米粒子的光热转换效率最高,其表面温度和光镊激光功率呈正相关(激光功率为0.6W时,其表面温度达200℃以上).最后对这类核壳纳米粒子具有良好热效应的原因进行了理论分析.本文建立的方法和获得的结果有助于深入了解硅-金核壳纳米材料的热效应,并展示了这类材料在癌症光热治疗等方面的应用前景.%This study presents a three-dimensional steady-state measurement of heat transduction of a single silica-gold core/shell nanoparticle by trapping it with a near-infrared laser and quantifies the temperature increase by measuring phase transition of a nearby lipid vesicle.Some factors such as the temperature in medium and laser power were investigated to evaluate their influences on the heating effect of the nanoparticles,and the efficiency of photothermal transduction of gold nanoshells and gold nanoparticles were compared.The results show that a gold nanoshell exhibits higher transduction efficiency and its surface temperature shows positive correlation with laser power(the temperature reaches above 200 ℃ at 0.6 W laser power).Finally,the excellent photothermal property of gold nanoshells is explained theoretically.The assay in this study is beneficial for a deep understanding of heating effect of silica-gold nanosells and shows a great promise of this material in photothermal therapy of cancers,etc.

  11. Near-infrared transmission spectroscopy of aqueous solutions: The influence of optical pathlength on signal-to-noise ratio

    DEFF Research Database (Denmark)

    Jensen, P.S.; Bak, J.

    2002-01-01

    The optimal choice of optical pathlength, source intensity, and detector for near-infrared transmission measurements of trace components in aqueous solutions depends on the strong absorption of water. In this study we examine under which experimental circumstances one may increase the pathlength...... to obtain a measurement with higher signal-to-noise ratio. The noise level of measurements at eight different pathlengths from 0.2 to 2.0 mm of pure water and of 1 g/dL aqueous glucose signals were measured using a Fourier transform near-infrared spectrometer and a variable pathlength transmission cell...

  12. Near-infrared uncaging or photosensitizing dictated by oxygen tension

    Science.gov (United States)

    Anderson, Erin D.; Gorka, Alexander P.; Schnermann, Martin J.

    2016-11-01

    Existing strategies that use tissue-penetrant near-infrared light for the targeted treatment of cancer typically rely on the local generation of reactive oxygen species. This approach can be impeded by hypoxia, which frequently occurs in tumour microenvironments. Here we demonstrate that axially unsymmetrical silicon phthalocyanines uncage small molecules preferentially in a low-oxygen environment, while efficiently generating reactive oxygen species in normoxic conditions. Mechanistic studies of the uncaging reaction implicate a photoredox pathway involving photoinduced electron transfer to generate a key radical anion intermediate. Cellular studies demonstrate that the biological mechanism of action is O2-dependent, with reactive oxygen species-mediated phototoxicity in normoxic conditions and small molecule uncaging in hypoxia. These studies provide a near-infrared light-targeted treatment strategy with the potential to address the complex tumour landscape through two distinct mechanisms that vary in response to the local O2 environment.

  13. A calibration unit for the near-infrared spectropolarimeter SPIRou

    Science.gov (United States)

    Boisse, Isabelle; Perruchot, Sandrine; Bouchy, François; Dolon, François; Moreau, François; Sottile, Rico; Wildi, François

    2016-08-01

    SPIRou is a near-infrared spectropolarimeter and high precision radial velocity instrument, to be implemented at CFHT in end 2017. It focuses on the search for Earth-like planets around M dwarfs and on the study of stellar and planetary formation in the presence of stellar magnetic field. The calibration unit and the radial-velocity reference module are essential to the short- and long-term precision (1 m/s). We highlight the specificities in the calibration techniques compared to the spectrographs HARPS (at LaSilla, ESO) or SOPHIE (at OHP, France) due to the near-infrared wavelengths, the CMOS detectors, and the instrument design. We also describe the calibration unit architecture, design and production.

  14. Noninvasive detection of gas exchange rate by near infrared spectroscopy

    Science.gov (United States)

    Xu, Guodong; Mao, Zongzhen; Wang, Bangde

    2008-12-01

    In order to study the relationship among the oxygen concentration in skeletal muscle tissues and the heart rate (HR), oxygen uptake (VO2), respiratory exchange ratio (RER) during incremental running exercises on a treadmill, a near-infrared spectroscopy muscle oxygen monitor system is employed to measure the relative change in muscle oxygenation, with the heart rate, oxygen uptake, production of carbon dioxide (VCO2) and respiratory exchange ratio are recorded synchronously. The results indicate parameters mentioned above present regular changes during the incremental exercise. High correlations are discovered between relative change of oxy-hemoglobin concentration and heart rate, oxygen uptake, respiratory exchange ratio at the significance level (P=0.01). This research might introduce a new measurement technology and/or a novel biological monitoring parameter to the evaluation of physical function status, control the training intensity, estimation of the effectiveness of exercise. Keywords: near-infrared spectroscopy; muscle oxygen concentration; heart rate; oxygen uptake; respiratory exchange ratio.

  15. Cross Correlation Analysis of Multi-Channel Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Raul Fernandez Rojas

    2016-02-01

    Full Text Available In this paper we present the use of a signal proces sing technique to find dominant channels in near infrared spectroscopy (NIRS. Cross correlatio n is computed to compare measuring channels and identify delays among the channels. In addition, visual inspection was used to detect potential dominant channels. The results sho wed that the visual analysis exposed pain- related activations in the primary somatosensory co rtex (S1 after stimulation which is consistent with similar studies and the cross corre lation analysis found dominant channels on both cerebral hemispheres. The analysis also showed a relationship between dominant channels and neighbouring channels. Therefore, our results p resent a new method to detect dominant regions in the cerebral cortex using near-infrared spectroscopy. These results have also implications in the reduction of number of channels by eliminating irrelevant channels for the experiment

  16. TIRCAM2: The TIFR Near Infrared Imaging Camera

    CERN Document Server

    Naik, M B; Ghosh, S K; Poojary, S S; Jadhav, R B; Meshram, G S; Sandimani, P R; Bhagat, S B; D'Costa, S L A; Gharat, S M; Bakalkar, C B; Ninan, J P; Joshi, J S

    2012-01-01

    TIRCAM2 (TIFR Near Infrared Imaging Camera - II) is a closed cycle cooled imager that has been developed by the Infrared Astronomy Group at the Tata Institute of Fundamental Research for observations in the near infrared band of 1 to 3.7 microns with existing Indian telescopes. In this paper, we describe some of the technical details of TIRCAM2 and report its observing capabilities, measured performance and limiting magnitudes with the 2-m IUCAA Girawali telescope and the 1.2-m PRL Gurushikhar telescope. The main highlight is the camera's capability of observing in the nbL (3.59 microns) band enabling our primary motivation of mapping of Polycyclic Aromatic Hydrocarbon (PAH) emission at 3.3 microns.

  17. Near infrared organic photodetector utilizing a double electron blocking layer.

    Science.gov (United States)

    Shafian, Shafidah; Hwang, Heewon; Kim, Kyungkon

    2016-10-31

    A near infrared organic photodiode (OPD) utilizing a double electron blocking layer (EBL) fabricated by the sequential deposition of molybdenum (VI) oxide (MoO3) and poly(3,4ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) is reported. The double EBL improves the on/off current ratio of OPD up to 1.36 x 104 at -1V, which is one order of magnitude higher than PEDOT:PSS single EBL (2.45 x 103) and three orders of magnitude higher than that of MoO3 single EBL (7.86). The detectivity at near infrared (800 nm) at -1V is 4.90 x 1011 Jones, which is 2.83 times higher than the PEDOT:PSS single EBL and 2 magnitudes higher compared to the MoO3 single EBL.

  18. Near-infrared photodetector with reduced dark current

    Science.gov (United States)

    Klem, John F; Kim, Jin K

    2012-10-30

    A photodetector is disclosed for the detection of near-infrared light with a wavelength in the range of about 0.9-1.7 microns. The photodetector, which can be formed as either an nBp device or a pBn device on an InP substrate, includes an InGaAs light-absorbing layer, an InAlGaAs graded layer, an InAlAs or InP barrier layer, and an InGaAs contact layer. The photodetector can detect near-infrared light with or without the use of an applied reverse-bias voltage and is useful as an individual photodetector, or to form a focal plane array.

  19. Strategic sourcing: from periphery to the core.

    Science.gov (United States)

    Gottfredson, Mark; Puryear, Rudy; Phillips, Stephen

    2005-02-01

    As globalization changes the basis of competition, sourcing is moving from the periphery of corporate functions to the core. Always important in terms of costs, sourcing is becoming a strategic opportunity. But few companies are ready for this shift. Outsourcing has grown so sophisticated that even critical functions like engineering, R&D, manufacturing, and marketing can-and often should-be moved outside. And that, in turn, is changing the way companies think about their organizations, their value chains, and their competitive positions. Already, a handful of vanguard companies are transforming what used to be purely internal corporate functions into entirely new industries. Companies like UPS, Solectron, and Hewitt have created new business models by concentrating scale and skill within a single function. As these and other function-based companies grow, so does the potential value of outsourcing to all companies. Migrating from a vertically integrated company to a specialized provider of a single function is not a winning strategy for everyone. But all companies need to rigorously reassess each of their functions as possible outsourcing candidates. Presented in this article is a simple three-step process to identify which functions your company needs to own and protect, which can be best performed by what kinds of partners, and which could be turned into new business opportunities. The result of such an analysis will be a comprehensive capabilities-sourcing strategy. As a detailed examination of 7-Eleven's experience shows, the success of the strategy often hinges on the creativity with which partnerships are organized and managed. But only by first taking a broad, strategic view of capabilities sourcing can your company gain the greatest benefit from all of its sourcing choices.

  20. Cryogenic Tm: YAG Laser in the Near Infrared

    Science.gov (United States)

    2015-05-29

    REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < Cryogenic Tm:YAG Laser in the Near Infrared* Tso Yee Fan...therefore limits operation. However, operation at cryogenic temperature depopulates the lower laser level, reduces laser threshold, increases...efficiency, and greatly mitigates thermo-optic effects in crystalline host materials [21]-[23]. Here, we have used cryogenic cooling to enable laser

  1. Practical guide to interpretive near-infrared spectroscopy

    CERN Document Server

    Workman, Jr, Jerry

    2007-01-01

    Containing focused, comprehensive coverage, Practical Guide to Interpretive Near-Infrared Spectroscopy gives you the tools necessary to interpret NIR spectra. The authors present extensive tables, charts, and figures with NIR absorption band assignments and structural information for a broad range of functional groups, organic compounds, and polymers. They include visual spectral representation of all major compound functional groupings and NIR frequency ranges. Organized by functional group type and chemical structure, based on standard compound classification, the chapters are easy to

  2. [Near infrared spectroscopy study on water content in turbine oil].

    Science.gov (United States)

    Chen, Bin; Liu, Ge; Zhang, Xian-Ming

    2013-11-01

    Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for determination of water content in turbine oil. Through the 57 samples of different water content in turbine oil scanned applying near infrared (NIR) spectroscopy, with the water content in the turbine oil of 0-0.156%, different pretreatment methods such as the original spectra, first derivative spectra and differential polynomial least squares fitting algorithm Savitzky-Golay (SG), and successive projections algorithm (SPA) were applied for the extraction of effective wavelengths, the correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices, accordingly water content in turbine oil was investigated. The results indicated that the original spectra with different water content in turbine oil were pretreated by the performance of first derivative + SG pretreatments, then the selected effective wavelengths were used as the inputs of least square support vector machine (LS-SVM). A total of 16 variables selected by SPA were employed to construct the model of SPA and least square support vector machine (SPA-LS-SVM). There is 9 as The correlation coefficient was 0.975 9 and the root of mean square error of validation set was 2.655 8 x 10(-3) using the model, and it is feasible to determine the water content in oil using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in on-line monitoring of contamination such as water content in oil.

  3. Near-infrared sensitive organic-inorganic photorefractive device

    Science.gov (United States)

    Marinova, Vera; Liu, Ren-Chung; Lin, Shiuan-Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken-Yuh

    2016-10-01

    Organic-inorganic hybrid structure, assembled by Rh-doped Bi12TiO20 crystal and liquid crystal (LC) layer, operating at near-infrared range is proposed and demonstrated. Due to the photorefractive properties of inorganic substrate, light illumination caused a space charge field which acts as a driving force for LC molecules re-alignment and subsequent refractive index modulation. All optically controlled phase retardation ability has been demonstrated supporting possibilities for further infrared applications.

  4. Detection Limit of Glucose Concentration with Near-Infrared Absorption and Scattering Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LUO Yun-Han; HUANG Fu-Rong; LI Shi-Ping; CHEN Zhe

    2008-01-01

    @@ Theoretical analyses and Monte Carlo simulation are performed to investigate the detection limit of glucose concentration with near-infrared spectroscopy.The relation between detection limitation of glucose concentration and source-detector separation is derived.Monte Carlo simulation performed with a skin-layered model shows that the ratio of effective photons from the target layer could excess 50% by selecting proper source-detector separation,and that the detection limit of glucose concentration approaches to 0.28mM,which satisfies the requirement of food and drug administration for noninvasive glucose sensing.

  5. Degradation of near infrared and shortwave infrared imager performance due to atmospheric scattering of diffuse night illumination.

    Science.gov (United States)

    Vollmerhausen, Richard

    2013-07-20

    On moonless nights, airglow is the primary source of natural ground illumination in the near infrared and shortwave infrared spectral bands. Therefore, night vision imagers operating in these spectral bands view targets that are diffusely illuminated. Aerosol scattering of diffuse airglow illumination causes atmospheric path radiance and that radiance causes increased imager noise. These phenomena and their quantification are described in this paper.

  6. Optical and Near-Infrared Spectroscopy of the L Subdwarf SDSS J125637.13-022452.4

    NARCIS (Netherlands)

    Burgasser, Adam J.; Witte, Soeren; Helling, Christiane; Sanderson, Robyn E.; Bochanski, John J.; Hauschildt, Peter H.

    2009-01-01

    Red optical and near-infrared spectroscopy are presented for SDSS J125637.13-022452.4, one of only four L subdwarfs reported to date. These data confirm the low-temperature, metal-poor nature of this source, as indicated by prominent metal-hydride bands, alkali lines, and collision-induced H2 absorp

  7. Tunable Near-Infrared Luminescence in Tin Halide Perovskite Devices.

    Science.gov (United States)

    Lai, May L; Tay, Timothy Y S; Sadhanala, Aditya; Dutton, Siân E; Li, Guangru; Friend, Richard H; Tan, Zhi-Kuang

    2016-07-21

    Infrared emitters are reasonably rare in solution-processed materials. Recently, research into hybrid organo-lead halide perovskite, originally popular in photovoltaics,1-3 has gained traction in light-emitting diodes (LED) due to their low-cost solution processing and good performance.4-9 The lead-based electroluminescent materials show strong colorful emission in the visible region, but lack emissive variants further in the infrared. The concerns with the toxicity of lead may, additionally, limit their wide-scale applications. Here, we demonstrate tunable near-infrared electroluminescence from a lead-free organo-tin halide perovskite, using an ITO/PEDOT:PSS/CH3NH3Sn(Br1-xIx)3/F8/Ca/Ag device architecture. In our tin iodide (CH3NH3SnI3) LEDs, we achieved a 945 nm near-infrared emission with a radiance of 3.4 W sr(-1) m(-2) and a maximum external quantum efficiency of 0.72%, comparable with earlier lead-based devices. Increasing the bromide content in these tin perovskite devices widens the semiconductor bandgap and leads to shorter wavelength emissions, tunable down to 667 nm. These near-infrared LEDs could find useful applications in a range of optical communication, sensing and medical device applications.

  8. Near-Infrared Fluorescent Materials for Sensing of Biological Targets

    Directory of Open Access Journals (Sweden)

    Julia Xiaojun Zhao

    2008-05-01

    Full Text Available Near-infrared fluorescent (NIRF materials are promising labeling reagents for sensitive determination and imaging of biological targets. In the near-infrared region biological samples have low background fluorescence signals, providing high signal to noise ratio. Meanwhile, near-infrared radiation can penetrate into sample matrices deeply due to low light scattering. Thus, in vivo and in vitro imaging of biological samples can be achieved by employing the NIRF probes. To take full advantage of NIRF materials in the biological and biomedical field, one of the key issues is to develop intense and biocompatible NIRF probes. In this review, a number of NIRF materials are discussed including traditional NIRF dye molecules, newly developed NIRF quantum dots and single-walled carbon nanotubes, as well as rare earth metal compounds. The use of some NIRF materials in various nanostructures is illustrated. The enhancement of NIRF using metal nanostructures is covered as well. The fluorescence mechanism and bioapplications of each type of the NIRF materials are discussed in details.

  9. Synthesis of Non-blinking Semiconductor Quantum Dots Emitting in the Near-Infrared

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, Allison M. [Los Alamos National Laboratory; Mangum, Benjamin D. [Los Alamos National Laboratory; Piryatinski, Andrei [Los Alamos National Laboratory; Park, Young-Shin [Los Alamos National Laboratory; Htoon, Han [Los Alamos National Laboratory; Hollingsworth, Jennifer A. [Los Alamos National Laboratory

    2012-06-21

    Our previous work demonstrates that Quasi-Type II CdSe/CdS core-shell quantum dots with thick shells (3-5 nm) exhibit unique photophysical characteristics, including improved chemical robustness over typical thin-shelled core/shell systems and the elimination of blinking through suppression of nonradiative Auger recombination. Here we describe a new thick-shelled heterostructure, InP/CdS, which exhibits a Type II bandgap alignment producing near-infrared (NIR) emission. Samples with a range of shell thicknesses were synthesized, enabling shell-thickness-dependent study of the absorbance and emission spectra, fluorescence lifetimes, and quantum yields. InP/CdS/ZnS core/shell/shell structures were also synthesized to reduce cadmium exposure for applications in the biological environment. Single particle spectroscopy indicates reduced blinking and improved photostability with increasing shell thickness, resulting in thick-shelled dots that are appropriate for single-particle tracking measurements with NIR emission.

  10. CIBER : a near-infrared probe of the epoch of reionization

    Science.gov (United States)

    Sullivan, Ian Sorensen

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed to study the near-Infrared background by measuring fluctuations and the absolute spectrum. The platform of a sounding rocket enables observations of the near-Infrared background outside of narrow atmospheric windows that are uncontaminated by airglow. CIBER uses two spectrometers to measure the absolute brightness spectrum of the extragalactic near-Infrared background. One, a high-resolution Fabry-Perot spectometer, is tuned to the 854.5 nm CaII line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the near-Infrared background spectrum. The second spectrometer measures the near-Infrared background spectrum from 700 nm to 1800 nm, spanning the wavelength range where a Lyman limit cutoff feature from reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2 x 2 degree field of views with 7 arcsecond pixels, but have different band defining filters. The first imager has a wide band centered at 1600 nm, and images the background at the expected peak of the spectrum. The imagers?~@~Y wide field of view allows them to measure the distinctive power spectrum of first-light galaxy fluctuations peaking at 10 arcminutes. The second imager has a wide band centered at 1000 nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600 nm / 1000 nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or moderate-redshift galaxies. This work describes the design and

  11. Safety assessment of near infrared light emitting diodes for diffuse optical measurements

    Directory of Open Access Journals (Sweden)

    Onaral Banu

    2004-03-01

    Full Text Available Abstract Background Near infrared (NIR light has been used widely to monitor important hemodynamic parameters in tissue non-invasively. Pulse oximetry, near infrared spectroscopy, and diffuse optical tomography are examples of such NIR light-based applications. These and other similar applications employ either lasers or light emitting diodes (LED as the source of the NIR light. Although the hazards of laser sources have been addressed in regulations, the risk of LED sources in such applications is still unknown. Methods Temperature increase of the human skin caused by near infrared LED has been measured by means of in-vivo and in-vitro experiments. Effects of the conducted and radiated heat in the temperature increase have been analyzed separately. Results Elevations in skin temperature up to 10°C have been observed. The effect of radiated heat due to NIR absorption is low – less than 0.5°C – since emitted light power is comparable to the NIR part of sunlight. The conducted heat due to semiconductor junction of the LED can cause temperature increases up to 9°C. It has been shown that adjusting operational parameters by amplitude modulating or time multiplexing the LED decreases the temperature increase of the skin significantly. Conclusion In this study, we demonstrate that the major risk source of the LED in direct contact with skin is the conducted heat of the LED semiconductor junction, which may cause serious skin burns. Adjusting operational parameters by amplitude modulating or time multiplexing the LED can keep the LED within safe temperature ranges.

  12. Spitzer SAGE-Spec: Near Infrared Spectroscopy, Dust Shells, and Cool Envelopes in Extreme Large Magellanic Cloud Asymptotic Giant Branch Stars

    Science.gov (United States)

    Blum, R. D.; Srinivasan, S.; Kemper, F.; Ling, B.; Volk, K.

    2014-11-01

    K-band spectra are presented for a sample of 39 Spitzer Infrared Spectrograph (IRS) SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near-infrared—Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near-infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars was chosen from the luminous and red extreme ``tip" of the color-magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich ``stellar" cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near-infrared and mid-infrared colors. One object in our sample, HV 915, a known post-asymptotic giant branch star of the RV Tau type, exhibits CO 2.3 μm band head emission consistent with previous work that demonstrates that the object has a circumstellar disk. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  13. Spitzer SAGE-Spec: Near infrared spectroscopy, dust shells, and cool envelopes in extreme Large Magellanic Cloud asymptotic giant branch stars

    Energy Technology Data Exchange (ETDEWEB)

    Blum, R. D. [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Srinivasan, S.; Kemper, F.; Ling, B. [Academia Sinica, Institute of Astronomy and Astrophysics, 11F of Astronomy-Mathematics Building, NTU/AS, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Volk, K. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-11-01

    K-band spectra are presented for a sample of 39 Spitzer Infrared Spectrograph (IRS) SAGE-Spec sources in the Large Magellanic Cloud. The spectra exhibit characteristics in very good agreement with their positions in the near-infrared—Spitzer color-magnitude diagrams and their properties as deduced from the Spitzer IRS spectra. Specifically, the near-infrared spectra show strong atomic and molecular features representative of oxygen-rich and carbon-rich asymptotic giant branch stars, respectively. A small subset of stars was chosen from the luminous and red extreme ''tip'' of the color-magnitude diagram. These objects have properties consistent with dusty envelopes but also cool, carbon-rich ''stellar'' cores. Modest amounts of dust mass loss combine with the stellar spectral energy distribution to make these objects appear extreme in their near-infrared and mid-infrared colors. One object in our sample, HV 915, a known post-asymptotic giant branch star of the RV Tau type, exhibits CO 2.3 μm band head emission consistent with previous work that demonstrates that the object has a circumstellar disk.

  14. Nanoscale Biomolecular Detection Limit for Gold Nanoparticles Based on Near-Infrared Response

    Directory of Open Access Journals (Sweden)

    Mario D’Acunto

    2012-01-01

    Full Text Available Gold nanoparticles have been widely used during the past few years in various technical and biomedical applications. In particular, the resonance optical properties of nanometer-sized particles have been employed to design biochips and biosensors used as analytical tools. The optical properties of nonfunctionalized gold nanoparticles and core-gold nanoshells play a crucial role for the design of biosensors where gold surface is used as a sensing component. Gold nanoparticles exhibit excellent optical tunability at visible and near-infrared frequencies leading to sharp peaks in their spectral extinction. In this paper, we study how the optical properties of gold nanoparticles and core-gold nanoshells are changed as a function of different sizes, shapes, composition, and biomolecular coating with characteristic shifts towards the near-infrared region. We show that the optical tenability can be carefully tailored for particle sizes falling in the range 100–150 nm. The results should improve the design of sensors working at the detection limit.

  15. Zwitterion functionalized gold nanoclusters for multimodal near infrared fluorescence and photoacoustic imaging

    Directory of Open Access Journals (Sweden)

    Danjin Shen

    2017-05-01

    Full Text Available Gold nanoclusters (Au NCs are an emerging type of theranostic agents combining therapeutic and imaging features with reduced toxicity. Au NCs stabilized by a zwitterion ligand with a fine control of the metal core size and the ligand coverage were synthesized by wet chemistry. Intense fluorescence signal is reported for the highest ligand coverage, whereas photoacoustic signal is stronger for the largest metal core. The best Au NC candidate with an average molecular weight of 17 kDa could be detected with high sensitivity on a 2D-near-infrared imaging instrument (limit of detection (LOD = 2.3 μM and by photoacoustic imaging. In vitro and in vivo experiments demonstrate an efficient cell uptake in U87 cell lines, a fast renal clearance (t1/2α = 6.5 ± 1.3 min, and a good correlation between near infrared fluorescence and photoacoustic measurements to follow the early uptake of Au NCs in liver.

  16. Near-infrared Hubble Space Telescope polarimetry of a complete sample of narrow-line radio galaxies

    CERN Document Server

    Ramírez, E A; Axon, D; Batcheldor, D; Packham, C; Lopez-Rodriguez, E; Sparks, W; Young, S

    2014-01-01

    We present an analysis of 2.05 $\\mu$m Hubble Space Telescope (HST) polarimetric data for a sample of 13 nearby Fanaroff-Riley type II (FRII) 3CR radio sources ($0.03cores of the NLRG in our sample are intrinsically highly polarised in the near-IR ($6 < P_{2.05\\mu m} < 60$ per cent), with the electric-vector (E-vector) perpendicular to the radio axis in 54 per cent of the sources. The levels of extinction required to produce near-infrared polarisation by the dichroic extinction mechanism are consistent with the measured values reported in Ram\\'irez et al. (2014), provided that this mechanism has its maximum efficiency. This consistency suggests that the nuclear polarisation could be due to dichroic extinction. In this case, toroidal magnetic fields that are highly coherent would be required in the circumnuclear tori to align the elongated dust grains responsible for the dichroic extin...

  17. A Road Map for the Generation of a Near-Infrared Guide Star Catalog for Thirty Meter Telescope Observations

    Indian Academy of Sciences (India)

    Smitha Subramanian; Annapurni Subramaniam; T Sivarani; Luc Simard; G. C. Anupama; Kim Gillies; A. N. Ramaprakash; B. Eswar Reddy

    2016-09-01

    The near-infrared instruments in the upcoming Thirty Meter Telescope (TMT) will be assisted by a multi conjugate Adaptive Optics (AO) system. For the efficient operation of the AO system, during observations, a near-infrared guide star catalog which goes as faint as 22 mag in ${\\rm J}_{{\\rm Vega}}$ band is essential and such a catalog does not exist. A methodology, based on stellar atmospheric models, to compute the expected near-infrared magnitudes of stellar sources from their optical magnitudes is developed. The method is applied and validated in JHKs bands for a magnitude range of ${\\rm J}_{\\rm{Vega}}$ 16--22 mag. The methodology is also applied and validated using the reference catalog of PAN STARRS. We verified that the properties of the final PAN STARRS optical catalog will satisfy the requirements of TMT IRGSC and will be one of the potential sources for the generation of the final catalog. In a broader context, this methodology is applicable for the generation of a guide star catalog for any existing/upcoming near-infrared telescopes.

  18. Glucose response of near-infrared alginate-based microsphere sensors under dynamic reversible conditions.

    Science.gov (United States)

    Chaudhary, Ayesha; Harma, Harri; Hanninen, Pekka; McShane, Michael J; Srivastava, Rohit

    2011-08-01

    Minimally invasive optical glucose biosensors with increased functional longevity form one of the most promising techniques for continuous glucose monitoring, because of their long-term stability, reversibility, repeatability, specificity, and high sensitivity. They are based on the principle of competitive binding and fluorescence resonance energy transfer. Moving to the near-infrared region of the spectrum has the potential to improve signal throughput for implanted sensors, but requires a change in dye chemistry that could alter response sensitivity, range, and toxicity profiles. The near-infrared dissolved-core alginate microsphere sensors were fabricated by emulsion followed by surface coating by layer-by-layer self-assembly. The particles were characterized for sensor stability, sensor response, and reversibility in deionized water and simulated interstitial fluid. The sensor response to step changes in bulk glucose concentrations was also evaluated under dynamic conditions using a microflow cell unit. Finally, in vitro cytotoxicity assays were performed with L929 mouse fibroblast cell lines to demonstrate preliminary biocompatibility of the sensors. The glucose sensitivity under controlled and dynamic conditions was observed to be 0.86%/mM glucose with an analytical response range of 0-30 mM glucose, covering both the physiological and pathophysiological range. The sensor demonstrated a repeatable, reversible, and reproducible response, with a maximum response time of 120 s. In vitro cytotoxicity assays revealed nearly 95% viability of cells, thereby suggesting that the alginate microsphere sensor system does not exhibit cytotoxicity. The incorporation of near-infrared dyes shows promise in improving sensor response because of their high sensitivity and improved tissue penetration of infrared light. The sensitivity for the sensors was approximately 1.5 times greater than that observed for visible dye sensors, and the new dye chemistry did not significantly

  19. Narrow-band single-photon emission in the near infrared for quantum key distribution.

    Science.gov (United States)

    Wu, E; Jacques, Vincent; Zeng, Heping; Grangier, Philippe; Treussart, François; Roch, Jean-François

    2006-02-06

    We present a detailed study of photophysical properties of single color centers in natural diamond samples emitting in the near infrared under optical excitation. Photoluminescence of these single emitters has several striking features, including narrow-band (FWHM 2 nm) fully polarized emission around 780 nm, a short excited-state lifetime of about 2 ns, and perfect photostability at room temperature under our excitation conditions. Development of a triggered single-photon source relying on this single color center is discussed for application to quantum key distribution.

  20. Narrow-band single-photon emission in the near infrared for quantum key distribution

    CERN Document Server

    Wu, E; Jacques, V; Zeng, H; Grangier, Philippe; Jacques, Vincent; Zeng, Heping

    2005-01-01

    We report on the observation of single colour centers in natural diamond samples emitting in the near infrared region when optically excited. Photoluminescence of these single emitters have several striking features, such as a narrow-band fully polarized emission (FWHM 2 nm) around 780 nm, a short excited-state lifetime of about 2 ns, and perfect photostability at room temperature under our excitation conditions. We present a detailed study of their photophysical properties. Development of a triggered single-photon source relying on this single colour centre is discussed in the prospect of its application to quantum key distribution.

  1. NIMBUS: A Near-Infrared Multi-Band Ultraprecise Spectroimager for SOFIA

    Science.gov (United States)

    McElwain, Michael W.; Mandell, Avi; Woodgate, Bruce E.; Spiegel, David S.; Madhusudhan, Nikku; Amatucci, Edward; Blake, Cullen; Budinoff, Jason; Burgasser, Adam; Burrows, Adam; Clampin, Mark C.; Conroy, Charlie; Deming, L. Drake; Dunham, Edward; Foltz, Roger; Gong, Qian; Knutson, Heather; Muench, Theodore; Murray-Clay, Ruth; Peabody, Hume; Rauscher, Bernard J.; Rinehart, Stephen A.; Villanueva, Geronimo

    2012-01-01

    We present a new and innovative near-infrared multi-band ultraprecise spectroimager (NIMBUS) for SOFIA. This instrument will enable many exciting observations in the new age of precision astronomy. This optical design splits the beam into 8 separate spectral bandpasses, centered around key molecular bands from 1 to 4 microns. Each spectral channel has a wide field of view for simultaneous observations of a reference star that can decorrelate time-variable atmospheric and optical assembly effects, allowing the instrument to achieve ultraprecise photometry for a wide variety of astrophysical sources

  2. Near-Infrared, Adaptive Optics Observations of the T Tauri Multiple-Star System

    CERN Document Server

    Furlan, E; Watson, D M; Uchida, K I; Brandl, B R; Keller, L D; Herter, T L

    2003-01-01

    With high-angular-resolution, near-infrared observations of the young stellar object T Tauri at the end of 2002, we show that, contrary to previous reports, none of the three infrared components of T Tau coincide with the compact radio source that has apparently been ejected recently from the system (Loinard, Rodriguez, and Rodriguez 2003). The compact radio source and one of the three infrared objects, T Tau Sb, have distinct paths that depart from orbital or uniform motion between 1997 and 2000, perhaps indicating that their interaction led to the ejection of the radio source. The path that T Tau Sb took between 1997 and 2003 may indicate that this star is still bound to the presumably more massive southern component, T Tau Sa. The radio source is absent from our near-infrared images and must therefore be fainter than K = 10.2 (if located within 100 mas of T Tau Sb, as the radio data would imply), still consistent with an identity as a low-mass star or substellar object.

  3. [Detection of Adulteration in Milk Powder with Starch Near Infrared].

    Science.gov (United States)

    Wang, Ning-ning; Shen, Bing-hui; Guan, Jian-jun; Zhao, Zhong-rui; Zhu, Ye-wei; Zhang, Lu-da; Yan, Yan-lu; Zheng, Yu-yan; Dong, Cheng-yu; Kang, Ding-ming

    2015-08-01

    Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together

  4. [Near-infrared Raman spectroscopy for diagnosis of gastric cancer].

    Science.gov (United States)

    Jin, Shaoqin; Mao, Hua

    2014-03-01

    To establish a method for early diagnosis of gastric cancer using near-infrared Raman spectroscopy. A rapid near-infrared Raman system was used to examine the tissue specimens of pathologically confirmed gastric cancer (33 cases), gastric precancerous lesions (27 cases), and normal gastric mucosa (45 cases). All the specimens were obtained from 105 patients undergoing gastrectomy or endoscopic biopsy of suspected gastric lesions. High-quality Raman spectra ranging from 700 to 1800 cm(-1) were acquired from the gastric tissues within 5 s. The distribution pattern of Raman spectra in gastric cancer differed significantly from those of gastric precancerous lesions and normal gastric mucosa, particularly in the spectral ranges of 853 cm(-1), 936 cm(-1), 1003 cm(-1), 1032 cm(-1), 1174 cm(-1), 1208 cm(-1), 1323 cm(-1), 1335 cm(-1), 1450 cm(-1), and 1655 cm(-1), which contained signals related to proteins, nucleic acids and lipids. The diagnostic decision algorithm based on the Raman peak intensity ratios of I1003/ I1337, I1003/I1445, I1003/I1655, and I1156/I1655 yielded remarkable differences in gastric cancer from gastric precancerous lesions and normal gastric mucosa, and the ratios were significantly higher in normal gastric tissues (Pinfrared Raman spectroscopy using PCA-LDA algorithms associated with leave- one-out and cross-validation method showed diagnostic sensitivities of 81.5%, 85.3%, and 100%, and specificities of 86.4%, 100%, and 97.4% for normal gastric mucosa, precancerous lesions and gastric cancer, respectively. near-infrared Raman spectroscopy in conjunction with intensity ratio algorithms shows the potential for noninvasive diagnosis and detection of gastric malignancy at the molecular level.

  5. Near infrared polarimetry of a sample of blazars*

    Directory of Open Access Journals (Sweden)

    Pulido J. A. Acosta

    2013-12-01

    Full Text Available Polarization variability is one of the most ubiquitous characteristic of blazars. Near infrared (NIRpolarization measurements of blazars are not common, contrary to the optical ones. Nonetheless, the NIR regime can be essential to understand correlated or non-correlated behaviour between the optical and radio energy ranges. In this work, we report on NIR polarimetry measurements of a sample of 28 blazars, collected with LIRIS at WHT/La Palma in several campaigns during 2011. The majority of the blazars were observed more than one epoch using two filters (J and Ks. Here we present preliminary results for few selected targets.

  6. Near Infrared absorbing iron-complexed colorants for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Sekar, N., E-mail: n.sekar@ictmumbai.edu.i [Department of Dyestuff Technology, University Institute of Chemical Technology (UICT), University of Bombay, Mumbai 400019 (India); Raut, Rajesh K.; Umape, Prashant G. [Department of Dyestuff Technology, University Institute of Chemical Technology (UICT), University of Bombay, Mumbai 400019 (India)

    2010-04-15

    Near Infrared absorbing colorants have several applications in the high technology area like heat ray blocking, energy conversion, and optical data storage. All these applications require that the colorants need to have broadband absorption extending up to the NIR region as well improved thermal stability. With the above objective in mind several analogues of pigment Green B (C.I. Acid Green 1) are prepared with improved thermal stability. These novel colorants are obtained by the incorporation of carboxamide group which imparts higher thermal stability. The spectral and TGA studies have shown that they are superior colorants, for application into photovoltaic cells.

  7. Monitoring Key Parameters in Bioprocesses Using Near-Infrared Technology

    Directory of Open Access Journals (Sweden)

    Elena Tamburini

    2014-10-01

    Full Text Available Near-infrared spectroscopy (NIRS is known to be a rapid and non-destructive technique for process monitoring. Bioprocesses are usually complex, from both the chemical (ill-defined medium composition and physical (multiphase matrix aspects, which poses an additional challenge to the development of robust calibrations. We investigated the use of NIRS for on-line and in-line monitoring of cell, substrate and product concentrations, during aerobic and anaerobic bacterial fermentations, in different fermentation strategies. Calibration models were built up, then validated and used for the automated control of fermentation processes. The capability of NIR in-line to discriminate among differently shaped bacteria was tested.

  8. Exploring process dynamics by near infrared spectroscopy in lactic fermentations

    DEFF Research Database (Denmark)

    Svendsen, Carina; Cieplak, Tomasz; van der Berg, Franciscus Winfried J

    2016-01-01

    In the industrial production of yoghurt, measurement of pH is normally the only in-line technique applied as a real-time monitoring signalfor following the dynamics during the fermentation process. However, every dairy company would benefit from an in-line technique giving information about...... the chemical composition, physical/textural properties and/or microbial contamination. In this study lactic fermentation batches with the starter bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are explored by in-line near infrared (NIR) spectroscopy. The dynamics obtained...

  9. Near-infrared spectroscopy of comet Bradfield 1979l

    Science.gov (United States)

    Danks, A. C.; Dennefeld, M.

    1981-02-01

    Spectroscopic observations using an unintensified reticon detector are presented of comet Bradfield 1979l, covering the spectral region from 6100 to 11,000 A. The red CN 2-0, 3-1, and 1-0 bands are easily identified in the nuclear region and their intensity ratios are used to determine that the vibrational transition probability for the ground electronic state lies between 0.32 and 1/sec. The CN 2-0 and 1-0 bands are also present in the coma. The interest in simultaneous measurements of the near-infrared and space UV of future comets is pointed out.

  10. Near-infrared organic materials and emerging applications

    CERN Document Server

    Wang, Zhi Yuan

    2013-01-01

    Highlighting emerging applications of near-infrared (NIR) organic materials that are currently receiving great attention due to their potential use in optical communications, biomedicine, and camouflage materials, this cutting-edge book reviews important recent advances in an accessible style suitable for researchers and graduates in the field on organic/polymer solar cells, optical communications, and advanced optoelectronics. A beacon in the field literature, this comprehensive work discusses several areas of research and development including thermal control and emission detectors in which

  11. On the near infrared variability of chemically peculiar stars

    CERN Document Server

    Catalano, F A

    1998-01-01

    Some CP stars have recently been discovered by Catalano et al. (1991) to be variable also in the near infrared, although with smaller amplitudes than in the visible. Hence an observational campaign was started in which the infrared light variability of a number of CP2 and CP4 stars has been investigated at the ESO-La Silla Observatory in the bands J, H, and K. As a general result, infrared variations show the same behavior in all three filters but amplitudes are smaller than in the visible.

  12. Measuring moisture in cheese by near infrared absorption spectroscopy.

    Science.gov (United States)

    McKenna, D

    2001-01-01

    Data in the literature indicate that the measurement of moisture in cheese by near infrared transmittance (NIT) is more accurate than by reflectance (NIR). The accuracy of the NIT measurement (SEP) was calculated for Edam, Gouda, Brie, Colby, and Cheddar. A range of SEP values (0.12-0.35) was obtained using different methods of calibration for different types of samples. There was close agreement between these results, as they related to the precision of the reference method. The calibration validation technique described as Standard Error of Cross Validation (SECV) generated results that compared very closely to the equivalent SEP values for independent sample sets.

  13. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    Science.gov (United States)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  14. Investigation of a near-infrared-ray computed tomography scanner

    Science.gov (United States)

    Sato, Eiichi; Oda, Yasuyuki; Satoi, Yuichi; Yamaguchi, Satoshi; Ishii, Tomotaka; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Watanabe, Manabu; Kusachi, Shinya

    2016-10-01

    In the near-infrared-ray computed tomography (NIR-CT) scanner, NIR rays are produced from a light-emitting diode (LED) and detected using an NIR phototransistor (PT). The wavelengths of the LED peak intensity and the PT high sensitivity in the data table are both 940 nm. The photocurrents flowing through the PTR are converted into voltages using an emitter-follower circuit, and the output voltages are sent to a personal computer through an analog-digital converter. The NIR projection curves for tomography are obtained by repeated linear scans and rotations of the object, and the scanning is conducted in both directions of its movement.

  15. The PAH contribution to AGN near-infrared emission

    Science.gov (United States)

    Marco, O.; Brooks, K.

    In the course of building ``unified models'' of Active Galactic Nuclei, the near infrared emission in the central kilo-parsec nuclear region is a key parameter: this wavelength range corresponds to the hot to warm dust emission, which originates in the torus and the Narrow Line Region (from a few parsecs to hundreds of parsecs). The measured flux is interpreted in terms of thermal emission and, via a dust modelisation, torus models are built. Using ISAAC at VLT, we observed a sample of AGNs in order to estimate the relative contribution between the thermal continuum emission from silicate & graphite dust grains and PAH molecules.

  16. The Formation of Massive Stars: from Herschel to Near-Infrared

    Directory of Open Access Journals (Sweden)

    Paolo Persi

    2014-12-01

    Full Text Available We have studied a number of selected high mass star forming regions, including high resolution near-infrared broad- and narrow-band imaging, Herschel (70, 160, 250, 350 and 500 μm and Spitzer (3.6, 4.5, 5.8 and 8.0 m images. The preliminary results of one of this region, IRAS 19388+2357(MOL110 are discussed. In this region a dense core has been detected in the far-infrared, and a young stellar cluster has been found around this core. Combining near-IR data with Spitzer and Herschel photometry we have derived the spectral energy distribution of Mol110. Finally comparing our H2 and Kc narrow-band images, we have found an H2 jet in this region.

  17. Silicon photomultipliers for improved detection of low light levels in miniature near-infrared spectroscopy instruments.

    Science.gov (United States)

    Zimmermann, R; Braun, F; Achtnich, T; Lambercy, O; Gassert, R; Wolf, M

    2013-05-01

    Silicon photomultipliers are novel solid state photodetectors that recently became commercially available. The goal of this paper was to investigate their suitability for low light level detection in miniaturized functional near-infrared spectroscopy instruments. Two measurement modules with a footprint of 26×26 mm(2) were built, and the signal-to-noise ratio was assessed for variable source-detector separations between 25 and 65 mm on phantoms with similar optical properties to those of a human head. These measurements revealed that the signal-to-noise ratio of the raw signal was superior to an empirically derived design requirement for source-detector separations up to 50 mm. An arterial arm occlusion was also performed on one of the authors in vivo, to induce reproducible hemodynamic changes which confirmed the validity of the measured signals. The proposed use of silicon photomultipliers in functional near-infrared spectroscopy bears large potential for future development of precise, yet compact and modular instruments, and affords improvements of the source-detector separation by 67% compared to the commonly used 30 mm.

  18. Porphyrin Based Near Infrared-Absorbing Materials for Organic Photovoltaics

    Science.gov (United States)

    Zhong, Qiwen

    The conservation and transformation of energy is essential to the survival of mankind, and thus concerns every modern society. Solar energy, as an everlasting source of energy, holds one of the key solutions to some of the most urgent problems the world now faces, such as global warming and the oil crisis. Advances in technologies utilizing clean, abundant solar energy, could be the steering wheel of our societies. Solar cells, one of the major advances in converting solar energy into electricity, are now capturing people's interest all over the globe. While solar cells have been commercially available for many years, the manufacturing of solar cells is quite expensive, limiting their broad based implementation. The cost of solar cell based electricity is 15-50 cents per kilowatt hour (¢/kwh), depending on the type of solar cell, compared to 0.7 ¢/kwh for fossil fuel based electricity. Clearly, decreasing the cost of electricity from solar cells is critical for their wide spread deployment. This will require a decrease in the cost of light absorbing materials and material processing used in fabricating the cells. Organic photovoltaics (OPVs) utilize organic materials such as polymers and small molecules. These devices have the advantage of being flexible and lower cost than conventional solar cells built from inorganic semiconductors (e.g. silicon). The low cost of OPVs is tied to lower materials and fabrication costs of organic cells. However, the current power conversion efficiencies of OPVs are still below 15%, while convention crystalline Si cells have efficiencies of 20-25%. A key limitation in OPVs today is their inability to utilize the near infrared (NIR) portion of the solar spectrum. This part of the spectrum comprises nearly half of the energy in sunlight that could be used to make electricity. The first and foremost step in conversion solar energy conversion is the absorption of light, which nature has provided us optimal model of, which is

  19. Prediction of dissolution profiles by non-destructive near infrared spectroscopy in tablets subjected to different levels of strain.

    Science.gov (United States)

    Hernandez, Eduardo; Pawar, Pallavi; Keyvan, Golshid; Wang, Yifan; Velez, Natasha; Callegari, Gerardo; Cuitino, Alberto; Michniak-Kohn, Bozena; Muzzio, Fernando J; Romañach, Rodolfo J

    2016-01-01

    This study describes how the strain on formulation components affects dissolution and how near infrared spectroscopy can be used to predict dissolution. Strain (exposure to shear stress) applied during powder mixing affects the interaction between formulation components. Particles experience shear strain when they move relative to each other in a process affecting the properties of the final product. This stress affects the dissolution of oral solid dosages forms. However, dissolution testing destroys the entire tablet, making it impossible to further evaluate tablet properties when an out of specification result is obtained. Thus, a nondestructive technique such as near infrared spectroscopy is desirable to predict dissolution. The aim of this study was to predict dissolution on tablets with different levels of strain (shear) using near infrared spectroscopy in combination with multivariate data analysis. Shear was induced using a modified Couette cell on the powder mixture and tablets from these mixtures were produced using a tablet press emulator. Tablets produced with different strain levels were measured using near infrared spectroscopy. Spectra were obtained in diffuse reflectance mode and pretreated with baseline correction to maintain the physical and chemical information of the tablets. Dissolution profiles were obtained using USP Apparatus 2 as a reference method. Principal component analysis was used to study the sources of variation in the spectra obtained. Partial least squares 2 was used to predict dissolution on tablets with different levels of strain.

  20. Ischemic stroke assessment with near-infrared spectroscopy

    Science.gov (United States)

    Chen, Weiguo; Li, Pengcheng; Zeng, Shaoqun; Luo, Qingming; Hu, Bo

    1999-09-01

    Many authors have elucidated the theory about oxygenated hemoglobin, deoxygenated hemoglobin absorption in near-infrared spectrum. And the theory has opened a window to measure the hemodynamic changes caused by stroke. However, no proper animal model still has established to confirm the theory. The aim of this study was to validate near-infrared cerebral topography (NCT) as a practical tool and to try to trace the focal hemodynamic changes of ischemic stroke. In the present study, middle cerebral artery occlusion model and the photosensitizer induced intracranial infarct model had been established. NCT and functional magnetic resonance image (fMRI) were obtained during pre- and post-operation. The geometric shape and infarct area of NCT image was compared with the fMRI images and anatomical samples of each rat. The results of two occlusion models in different intervene factors showed the NCT for infarct focus matched well with fMRI and anatomic sample of each rats. The instrument might become a practical tool for short-term prediction of stroke and predicting the rehabilitation after stroke in real time.

  1. Length-free near infrared measurement of newborn malnutrition

    Science.gov (United States)

    Mustafa, Fatin Hamimi; Bek, Emily J.; Huvanandana, Jacqueline; Jones, Peter W.; Carberry, Angela E.; Jeffery, Heather E.; Jin, Craig T.; McEwan, Alistair L.

    2016-11-01

    Under-nutrition in neonates can cause immediate mortality, impaired cognitive development and early onset adult disease. Body fat percentage measured using air-displacement-plethysmography has been found to better indicate under-nutrition than conventional birth weight percentiles. However, air-displacement-plethysmography equipment is expensive and non-portable, so is not suited for use in developing communities where the burden is often the greatest. We proposed a new body fat measurement technique using a length-free model with near-infrared spectroscopy measurements on a single site of the body - the thigh. To remove the need for length measurement, we developed a model with five discrete wavelengths and a sex parameter. The model was developed using air-displacement-plethysmography measurements in 52 neonates within 48 hours of birth. We identified instrumentation required in a low-cost LED-based screening device and incorporated a receptor device that can increase the amount of light collected. This near-infrared method may be suitable as a low cost screening tool for detecting body fat levels and monitoring nutritional interventions for malnutrition in neonates and young children in resource-constrained communities.

  2. Advancing Nebular Astrophysics through Near-Infrared Spectroscopic Mapping

    Science.gov (United States)

    Waller, William H.; Kutyrev, A.; Silverberg, R.; Woodgate, B.; Allen, L.

    2006-12-01

    Infrared continuum surveys, optical emission-line surveys, and radio CO and HI surveys have revealed the star-forming ISM as a complex "froth" of shells, filaments, blobs, and myriad "working surfaces" whose origin and evolution remain poorly understood. The generic relations between these nebular structures and the embedded star clusters that have been discovered in abundance throughout the Galaxy by the Spitzer Space Telescope have yet to be deciphered. To address these challenges, we consider the options for carrying out wide-field narrow-band imaging surveys of the near-infrared line emission from the Milky Way and other nearby star-forming galaxies. The near-IR part of the EM spectrum is rich with diagnostic nebular emission features. We draw from the experiences gained from the ABU/SPIREX near-IR telescope that operated in Antarctica in the late 1990s, and from the Brackett-Alpha Mapper (BAM) -a Fabry-Perot spectrometer that successfully measured kinematics of the warm-ionized hydrogen gas in the northern Milky Way. Options for deploying a multi-line near-infrared spectroscopic mapper on SOFIA, high-altitude balloons, and the lunar surface will be discussed.

  3. Type Ia Supernova as Standard Candles in the Near Infrared

    Science.gov (United States)

    Wood-Vasey, Michael; Garnavich, Peter; Matheson, Thomas; Jha, Saurabh; Rest, Armin; Allen, Lori

    2011-08-01

    We propose to observe 15 SNeIa in the near infrared (NIR) with WHIRC on the WIYN telescope during 12 nights of bright time in 2011B. These observations will create an infrared Hubble diagram extending to z~0.1 to verify recent evidence that SNIa are excellent standard candles in the NIR. We will observe 15 SNeIa at 0.02color evolution in the near infrared where dust extinction is significantly reduced. In addition these NIR data will allow us to (1) explore the recent correlation between optical luminosity and host galaxy mass; (2) improve our understanding of intrinsic colors of SNeIa, (3) and study the nature of dust in galaxies beyond our Milky Way. Our ideal observing plan would consist of nights spaced every three days in each of four consecutive lunations in 2011B. This is a pilot proposal. If successful, this project will lead to a larger survey to obtain NIR luminosity distances to 100 SNeIa out to z<0.1 to provide a solid anchor for measuring luminosity distances in the Universe. We are not asking for long-term status at this time.

  4. Properties of the Young Milky Way Globular Cluster Whiting 1 from Near-Infrared Photometry

    CERN Document Server

    Valcheva, A T; Lalova, A D; Nedialkov, P L; Ivanov, V D; Carraro, G

    2014-01-01

    Whiting 1 is a member of the fast-growing group of young globular clusters in the Milky Way halo. Preliminary estimates of its fundamental parameters have been provided using optical photometry and low resolution spectroscopy. In an attempt to strengthen our knowledge of Whiting 1, in this study we employ a complementary approach. Isochrone fitting method was applied on the Near-Infrared Color-Magnitude Diagram and yields an age t=5.7$\\pm$0.3 Gyr, metallicity $z$=0.006$\\pm$0.001 ([Fe/H]=$-$0.5$\\pm$0.1) and distance modulus $(m-M)_0$=17.48$\\pm$0.10. Our results confirm that Whiting 1 is a young and moderately metal-rich globular cluster. It is one of the youngest from the Sgr dSph. We fitted an Elson, Fall and Freeman (EFF) profile to the near-infrared number counts, and measured cluster core radius $r_c$=9.1${\\prime\\prime}$$\\pm$3.9${\\prime\\prime}$. Two probable eclipsing variables in the cluster were found from multi-epoch $V$ band photometry. Finally, an unknown galaxy cluster was identified on our $K$ vs. $...

  5. Near Infrared Spectroscopy of Young Brown Dwarfs in Upper Scorpius

    CERN Document Server

    Dawson, P; Ray, T P; Peterson, D E; Rodgers-Lee, D; Geers, V

    2014-01-01

    Spectroscopic follow-up is a pre-requisite for studies of the formation and early evolution of brown dwarfs. Here we present IRTF/SpeX near-infrared spectroscopy of 30 candidate members of the young Upper Scorpius association, selected from our previous survey work. All 24 high confidence members are confirmed as young very low mass objects with spectral types from M5 to L1, 15-20 of them are likely brown dwarfs. This high yield confirms that brown dwarfs in Upper Scorpius can be identified from photometry and proper motions alone, with negligible contamination from field objects (<4%). Out of the 6 candidates with lower confidence, 5 might still be young very low mass members of Upper Scorpius, according to our spectroscopy. We demonstrate that some very low mass class II objects exhibit radically different near infrared (0.6 - 2.5micron) spectra from class III objects, with strong excess emission increasing towards longer wavelengths and partially filled in features at wavelengths shorter than 1.25micron...

  6. Near infrared transmission through clothing: applications in sensing and screening

    Science.gov (United States)

    Hutchins, D. A.; Canal, C. M.; Saleem, A.; Davis, L. A. J.; Green, R. J.

    2011-11-01

    Experiments have been performed to demonstrate that near infrared (NIR) transmission through a wide range of clothing materials is possible. Studies have shown that the characteristics of NIR transmission are affected by both the type of fibre used, and the weave pattern. A series of experiments has indicated that NIR transmission is also dependent on other variables such as fabric porosity and dye colour. It is shown that, in many cases, transmission coefficients are sufficiently high that imaging and spectroscopy of objects hidden behind clothing samples should be possible. However, while transmission through clothing at NIR wavelengths in the 750-1,700 nm range is often more effective than in the visible or IR regions, the fabrics themselves will modify the transmitted signal in terms of spatial effects, intensity and spectral content. The paper also describes the possible use of near infrared signals to identify objects that are hidden behind clothing layers. This can be done using spectroscopy. It is important, however, to distinguish the various contributions that exist within the backscattered signal. A set of careful laboratory experiments have demonstrated that transmission through a set of different clothing fabrics does modify the spectral content of signals, but that the spectrum of a particular chemical can still be identified, provided certain steps are taken. These involve a set of careful calibration measurements, and the use of processing techniques for the retrieval of data. It will be shown that this is possible for both granular solids and selected liquids.

  7. NIRS3: The Near Infrared Spectrometer on Hayabusa2

    Science.gov (United States)

    Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Ohtake, Makiko; Arai, Takehiko; Arai, Tomoko; Hirata, Naru; Hiroi, Takahiro; Honda, Chikatoshi; Imae, Naoya; Komatsu, Mutsumi; Matsunaga, Tsuneo; Matsuoka, Moe; Matsuura, Shuji; Nakamura, Tomoki; Nakato, Aiko; Nakauchi, Yusuke; Osawa, Takahito; Senshu, Hiroki; Takagi, Yasuhiko; Tsumura, Kohji; Takato, Naruhisa; Watanabe, Sei-ichiro; Barucci, Maria Antonietta; Palomba, Ernesto; Ozaki, Masanobu

    2017-03-01

    NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 μm. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 μm-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K ( -85°C), which enables to retaining sufficient sensitivity and noise level in the 3 μm wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.

  8. Infrared and Near-Infrared Spectroscopy of Acetylacetone and Hexafluoroacetylacetone.

    Science.gov (United States)

    Howard, Daryl L; Kjaergaard, Henrik G; Huang, Jing; Meuwly, Markus

    2015-07-23

    The infrared and near-infrared spectra of acetylacetone, acetylacetone-d8, and hexafluoroacetylacetone are characterized from experiment and computations at different levels. In the fundamental region, the intramolecular hydrogen bonded OH-stretching transition is clearly observed as a very broad band with substantial structure and located at significantly lower frequency compared to common OH-stretching frequencies. There is no clear evidence for OH-stretching overtone transitions in the near-infrared region, which is dominated by the CH-stretching overtones of the methine and methyl CH bonds. From molecular dynamics (MD) simulations, with a potential energy surface previously validated for tunneling splittings, the infrared spectra are determined and used in assigning the experimentally measured ones. It is found that the simulated spectrum in the region associated with the proton transfer mode is exquisitely sensitive to the height of the barrier for proton transfer. Comparison of the experimental and the MD simulated spectra establishes that the barrier height is around 2.5 kcal/mol, which favorably compares with 3.2 kcal/mol obtained from high-level electronic structure calculations.

  9. NIRS3: The Near Infrared Spectrometer on Hayabusa2

    Science.gov (United States)

    Iwata, Takahiro; Kitazato, Kohei; Abe, Masanao; Ohtake, Makiko; Arai, Takehiko; Arai, Tomoko; Hirata, Naru; Hiroi, Takahiro; Honda, Chikatoshi; Imae, Naoya; Komatsu, Mutsumi; Matsunaga, Tsuneo; Matsuoka, Moe; Matsuura, Shuji; Nakamura, Tomoki; Nakato, Aiko; Nakauchi, Yusuke; Osawa, Takahito; Senshu, Hiroki; Takagi, Yasuhiko; Tsumura, Kohji; Takato, Naruhisa; Watanabe, Sei-ichiro; Barucci, Maria Antonietta; Palomba, Ernesto; Ozaki, Masanobu

    2017-07-01

    NIRS3: The Near Infrared Spectrometer is installed on the Hayabusa2 spacecraft to observe the target C-type asteroid 162173 Ryugu at near infrared wavelengths of 1.8 to 3.2 μm. It aims to obtain reflectance spectra in order to detect absorption bands of hydrated and hydroxide minerals in the 3 μm-band. We adopted a linear-image sensor with indium arsenide (InAs) photo diodes and a cooling system with a passive radiator to achieve an optics temperature of 188 K (-85°C), which enables to retaining sufficient sensitivity and noise level in the 3 μm wavelength region. We conducted ground performance tests for the NIRS3 flight model (FM) to confirm its baseline specifications. The results imply that the properties such as the signal-to-noise ratio (SNR) conform to scientific requirements to determine the degree of aqueous alteration, such as CM or CI chondrite, and the stage of thermal metamorphism on the asteroid surface.

  10. A Unified Near Infrared Spectral Classification Scheme for T Dwarfs

    CERN Document Server

    Burgasser, A J; Leggett, S K; Kirkpatrick, J D; Golimowski, D A; Burgasser, Adam J.; Golimowski, David A.

    2006-01-01

    A revised near infrared classification scheme for T dwarfs is presented, based on and superseding prior schemes developed by Burgasser et al. and Geballe et al., and defined following the precepts of the MK Process. Drawing from two large spectroscopic libraries of T dwarfs identified largely in the Sloan Digital Sky Survey and the Two Micron All Sky Survey, nine primary spectral standards and five alternate standards spanning spectral types T0 to T8 are identified that match criteria of spectral character, brightness, absence of a resolved companion and accessibility from both northern and southern hemispheres. The classification of T dwarfs is formally made by the direct comparison of near infrared spectral data of equivalent resolution to the spectra of these standards. Alternately, we have redefined five key spectral indices measuring the strengths of the major H$_2$O and CH$_4$ bands in the 1-2.5 micron region that may be used as a proxy to direct spectral comparison. Two methods of determining T spectra...

  11. The Surface of 2003EL61 in the Near Infrared

    CERN Document Server

    Trujillo, C A; Barkume, K M; Schaller, E L; Rabinowitz, D L

    2006-01-01

    We report the detection of crystalline water ice on the surface of 2003EL61. Reflectance spectra were collected from Gemini North telescope from 1.0 to 2.4 micron wavelength range, and from the Keck telescope across the 1.4 to 2.4 micron wavelength range. The signature of crystalline water ice is clear and obvious in all data collected. Like the surface of many outer solar system bodies, the surface of 2003EL61 is rich in crystalline water ice, which is energetically less favored than amorphous water ice at cold temperatures, suggesting resurfacing processes may be taking place. The near infrared color of the object is much bluer than a pure water ice model. Adding a near infrared blue component such as hydrogen cyanide or phyllosilicate clays improves the fit considerably, with hydrogen cyanide providing the greatest improvement. The addition of hydrated tholins and bitumens also improves the fit but is inconsistent with the neutral V-J reflectance of 2003EL61. A small decrease in reflectance beyond 2.3 micr...

  12. Application of ceramic phosphors for near infrared biomedical imaging technologies

    Science.gov (United States)

    Soga, Kohei; Tokuzen, Kimikazu; Tsuji, Kosuke; Yamano, Tomoyoshi; Venkatachalam, Nallusamy; Hyodo, Hiroshi; Kishimoto, Hidehiro

    2010-02-01

    Near infrared wavelength region between 0.8 and 2 μm is an attractive region for biomedical imaging due to the low loss in biomedical objects in the region. Rare-earth doped ceramic phosphors are known to emit efficient fluorescence in the same wavelength region. The authors have developed micro fluorescence bioimaging system for cellular or tissue imaging and macro one for in vivo imaging. This paper will review the materials synthesis for the near infrared fluorescence probes as well as the system development and demonstrative works. Er-doped or Yb/Er-doped ceramic phosphors were synthesized with required particle size. The phosphors were partly modified with polyethylene glycol to give dispersion and controlled interaction with the biological objects. By using the micro imaging system, nematodes, mouse tissue and M1 cells were observed by detecting 1.5 μm emission from Er doped in the ceramic phosphor. in vivo imaging with the same fluorescence scheme was also performed for the digestive organs of live mouse.

  13. The Vela Pulsar in the Near-Infrared

    CERN Document Server

    Shibanov, Y A; Sollerman, J; Lundqvist, P

    2003-01-01

    We report on the first detection of the Vela pulsar in the near-infrared with the VLT/ISAAC in the Js and H bands. The pulsar magnitudes are Js=22.71 +/- 0.10 and H=22.04 +/- 0.16. We compare our results with the available multiwavelength data and show that the dereddened phase-averaged optical spectrum of the pulsar can be fitted with a power law F_nu propto nu^(-alpha_nu) with alpha_nu = 0.12 +/- 0.05, assuming the color excess E(B-V)=0.055 +/-0.005 based on recent spectral fits of the emission of the Vela pulsar and its supernova remnant in X-rays. The negative slope of the pulsar spectrum is different from the positive slope observed over a wide optical range in the young Crab pulsar spectrum. The near-infrared part of the Vela spectrum appears to have the same slope as the phase-averaged spectrum in the high energy X-ray tail, obtained in the 2-10 keV range with the RXTE. Both of these spectra can be fitted with a single power law suggesting their common origin. Because the phase-averaged RXTE spectrum i...

  14. Dependence of Core and Extended Flux on Core Dominance Parameter for Radio Sources

    Indian Academy of Sciences (India)

    J. J. Nie; J. H. Yang

    2014-09-01

    Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investigated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux density, but it is not correlated with the extended flux density. When the core dominance parameter is higher than unity, it is not correlated with the core flux density, but it is linearly correlated with the extended flux density. Therefore, there are different results from different samples. The results can be explained using a relativistic beaming model.

  15. A near-infrared survey of the entire R Coronae Australis cloud

    Science.gov (United States)

    Haas, M.; Heymann, F.; Domke, I.; Drass, H.; Chini, R.; Hoffmeister, V.

    2008-09-01

    Aims: To understand low- to intermediate-mass star-formation in the nearby R Cr A molecular cloud, we try to identify the stellar content that is accessible with near-infrared observations. Methods: We obtained a JHKs band mosaic of ~10 arcmin × 60 arcmin covering the entire R CrA molecular cloud with unprecedented sensitivity. We present a catalogue of about 3500 near-infrared sources fainter than the saturation limit Ks ˜ 10 mag, reaching Ks ˜ 18 mag. We analysed the extended sources by inspecting their morphology and point sources by means of colour-colour and colour-magnitude diagrams. Additionally, we compared the extinction inferred from the NIR data with the line-of-sight dust emission at 1.2 mm. Sources towards high dust emission but relatively low H-Ks show a projected mm-excess; these sources are either immediately surrounded by cold circumstellar material or, if too red to be a true foreground object, they are embedded in the front layer of the 1.2 mm emitting dust cloud. In both cases they are most likely associated with the cloud. Results: By means of the projected mm-excess technique we find 33 new faint near-infrared sources deeply embedded in the Coronet cluster around R CrA, for which so far about 20 bright infrared stars have been known. In contrast to the Coronet region, both the northwestern dust ridge and the southeastern cloud condensation “C” appear to be devoid of associated stars detectable with our near-infrared data. Furthermore, about a dozen sources, which are spread over the entire molecular cloud region, exhibit a possible K-band excess, but only with marginal statistical significance (indicated K-band excess as real. Finally, while the Herbig-Haro-like objects seen on our maps are concentrated around the Coronet, we find four new nebulae also located farther down to the southeast. At the position of IRAS 18595-3712, an X-shaped bipolar nebula is resolved; its exciting star is hidden behind an edge-on disc. Conclusions: The

  16. A near-infrared interferometric survey of debris-disc stars. V. PIONIER search for variability

    Science.gov (United States)

    Ertel, S.; Defrère, D.; Absil, O.; Le Bouquin, J.-B.; Augereau, J.-C.; Berger, J.-P.; Blind, N.; Bonsor, A.; Lagrange, A.-M.; Lebreton, J.; Marion, L.; Milli, J.; Olofsson, J.

    2016-10-01

    Context. Extended circumstellar emission has been detected within a few 100 milli-arcsec around ≳10% of nearby main sequence stars using near-infrared interferometry. Follow-up observations using other techniques, should they yield similar results or non-detections, can provide strong constraints on the origin of the emission. They can also reveal the variability of the phenomenon. Aims: We aim to demonstrate the persistence of the phenomenon over the timescale of a few years and to search for variability of our previously detected excesses. Methods: Using Very Large Telescope Interferometer (VLTI)/Precision Integrated Optics Near Infrared ExpeRiment (PIONIER) in H band we have carried out multi-epoch observations of the stars for which a near-infrared excess was previously detected using the same observation technique and instrument. The detection rates and distribution of the excesses from our original survey and the follow-up observations are compared statistically. A search for variability of the excesses in our time series is carried out based on the level of the broadband excesses. Results: In 12 of 16 follow-up observations, an excess is re-detected with a significance of > 2σ, and in 7 of 16 follow-up observations significant excess (> 3σ) is re-detected. We statistically demonstrate with very high confidence that the phenomenon persists for the majority of the systems. We also present the first detection of potential variability in two sources. Conclusions: We conclude that the phenomenon responsible for the excesses persists over the timescale of a few years for the majority of the systems. However, we also find that variability intrinsic to a target can cause it to have no significant excess at the time of a specific observation. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program IDs 088.C-0266, 089.C-0365, 090.C-0526, 091.C-0576, 091.C-0597, 094.C-0232, and commissioning data.

  17. VICS82: The VISTA-CFHT Stripe 82 Near-infrared Survey

    Science.gov (United States)

    Geach, J. E.; Lin, Y.-T.; Makler, M.; Kneib, J.-P.; Ross, N. P.; Wang, W.-H.; Hsieh, B.-C.; Leauthaud, A.; Bundy, K.; McCracken, H. J.; Comparat, J.; Caminha, G. B.; Hudelot, P.; Lin, L.; Van Waerbeke, L.; Pereira, M. E. S.; Mast, D.

    2017-07-01

    We present the VISTA-CFHT Stripe 82 (VICS82) survey: a near-infrared (J+K s ) survey covering 150 square degrees of the Sloan Digital Sky Survey (SDSS) equatorial Stripe 82 to an average depth of J = 21.9 AB mag and K s = 21.4 AB mag (80% completeness limits; 5σ point-source depths are approximately 0.5 mag brighter). VICS82 contributes to the growing legacy of multiwavelength data in the Stripe 82 footprint. The addition of near-infrared photometry to the existing SDSS Stripe 82 coadd ugriz photometry reduces the scatter in stellar mass estimates to δ {log}({M}\\star )≈ 0.3 dex for galaxies with {M}\\star > {10}9 {M}⊙ at z≈ 0.5, and offers improvement compared to optical-only estimates out to z≈ 1, with stellar masses constrained within a factor of approximately 2.5. When combined with other multiwavelength imaging of the Stripe, including moderate-to-deep ultraviolet (GALEX), optical and mid-infrared (Spitzer-IRAC) coverage, as well as tens of thousands of spectroscopic redshifts, VICS82 gives access to approximately 0.5 Gpc3 of comoving volume. Some of the main science drivers of VICS82 include (a) measuring the stellar mass function of {L}\\star galaxies out to z˜ 1; (b) detecting intermediate-redshift quasars at 2≲ z≲ 3.5; (c) measuring the stellar mass function and baryon census of clusters of galaxies, and (d) performing cross-correlation experiments of cosmic microwave background lensing in the optical/near-infrared that link stellar mass to large-scale dark matter structure. Here we define and describe the survey, highlight some early science results, and present the first public data release, which includes an SDSS-matched catalog as well as the calibrated pixel data themselves.

  18. Regressive Analysis on Leaf Nitrogen Content and Near Infrared Reflectance and Its Application for Agricultural Farm Monitoring with Helicopter Mounted Near Infrared Camera

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-03-01

    Full Text Available Method for evaluation of nitrogen richness of tealeaves with near infrared reflectance is proposed. Also tea farm monitoring with helicopter mounted near infrared camera is proposed. Through experiments and regressive analysis, it is found that the proposed method and monitoring system is validated.

  19. Super-Resolution Imaging by using a Metallic Rod Array in the Near Infrared Region

    Institute of Scientific and Technical Information of China (English)

    YAO Jie; YE Yong-Hong

    2012-01-01

    An array of metallic rods can transport details below the diffraction limit of an object from the front face to the back face. This super-resolution imaging system has been studied in the microwave, mid-infrared and optical range. We investigate its performance in the near infrared (1550 nm) region. Numerical simulations show that the near-field components of dipole sources are transferred by the excitation and propagation of the surface plasmon mode of the rods. The appropriate length of rods is determined by the excited surface plasmon mode. The spatial resolution is greatly affected by the loss of metal.%An array of metallic rods can transport details below the diffraction limit of an object from the front face to the back face.This super-resolution imaging system has been studied in the microwave,mid-infrared and optical range.We investigate its performance in the near infrared (1550nm) region.Numerical simulations show that the near-field components of dipole sources are transferred by the excitation and propagation of the surface plasmon mode of the rods.The appropriate length of rods is determined by the excited surface plasmon mode.The spatial resolution is greatly affected by the loss of metal.

  20. Near-infrared emission from ZnO nanorods grown by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tu [Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology (HUST), 01 Dai Co Viet, Hanoi (Viet Nam); Tuan, N.T. [College of Science, Cantho University, 3/2, Ninh Kieu, Cantho (Viet Nam); Nguyen, Van Dung; Cuong, N.D.; Kien, N.D.T.; Huy, P.T. [Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology (HUST), 01 Dai Co Viet, Hanoi (Viet Nam); Nguyen, Van Hieu [International Training Institute for Material Sciences, Hanoi University of Science and Technology (HUST), 01 Dai Co Viet, Hanoi (Viet Nam); Nguyen, D.H., E-mail: hung.nguyenduy@hust.edu.vn [Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology (HUST), 01 Dai Co Viet, Hanoi (Viet Nam)

    2014-12-15

    We report the growth of ZnO nanorods on Si/SiO{sub 2} subtrates by the thermal evaporation method at different distances (substrate temperatures) from vapor source to substrates. SEM images showed that morphologies of nanorods were significantly affected by distance from the substrate to vapor source. Energy dispersive X-ray spectroscopy (EDS) spectra present change of the ratio of zinc to oxygen in ZnO nanostructures as the substrate temperature varied. X-ray diffraction patterns revealed that the prepared ZnO nanorods are preferentially oriented in the c-axis at lower substrate temperature. The shift towards small angle of the XRD pattern peaks is consistent with the presence of the redundant zinc and the lack oxygen in the ZnO lattice. The photoluminescence (PL) spectra of the ZnO nanorods show beside the near band edge UV emission, a very broad emission ranges from green to near-infrared (NIR). The NIR emission is interpreted as due to the transition of carriers between radiative recombination centers related to Zn interstitials and oxygen interstitials. - Highlights: • ZnO nanorods were grown by thermal evaporation method at different temperatures. • Morphologies of ZnO nanorods were strongly affected by substrate temperature. • The depth level emission presents broad bands from green to infrared region simultaneously. • The depth level emitting at long wavelength region enhances as reducing growth temperature. • Near-infrared emission from ZnO nanorods grown by thermal evaporation method.

  1. FIRST OPTICAL AND NEAR-INFRARED POLARIMETRY OF A MOLECULAR CLOUD FORMING A PROTO-BROWN DWARF CANDIDATE

    Energy Technology Data Exchange (ETDEWEB)

    Soam, A.; Maheswar, G. [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital-263 002 (India); Kwon, Jugmi; Tamura, Motohide [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Lee, Chang Won, E-mail: archana@aries.res.in [Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

    2015-04-20

    LDN 328 is cited as an example of a fairly isolated clump contracting to form multiple sub-cores, possibly through gravitational fragmentation. In one of these sub-cores, a proto-brown dwarf (L328-IRS) candidate is in the process of formation through the self-gravitating contraction, similar to the formation scenario of a low-mass star. We present results of our optical and near-infrared polarization observations of regions toward LDN 328. This is the first observational attempt to map the magnetic field geometry of a cloud harboring a proto-brown dwarf candidate associated with a sub-parsec-scale molecular outflow. On a parsec scale, the magnetic field is found to follow the curved structure of the cloud showing a head–tail morphology. The magnetic field is found to be well ordered over a 0.02–0.2 pc scale around L328-IRS. Taking into account the uncertainties in the determination of position angles, the projected angular offset between the magnetic field direction and the outflow axis is found to be in the range of 0°–70°. Considering outflow to be the proxy for the rotation axis, the result obtained in this study implies that the rotation axis in L328 is preferably parallel to the local magnetic field. The magnetic field strength estimated in the close vicinity of L328-IRS is ∼20 μG. Results from the present study suggest that the magnetic field may be playing a vital role even in the cores that are forming sub-stellar sources.

  2. Very bright, near-infrared single photon emitters in diamond

    Directory of Open Access Journals (Sweden)

    D. W. M. Lau

    2013-09-01

    Full Text Available We demonstrate activation of bright diamond single photon emitters in the near infrared range by thermal annealing alone, i.e., without ion implantation. The activation is crucially dependent on the annealing ambient. The activation of the single photon emitters is only observed when the sample is annealed in forming gas (4% H2 in Ar above temperatures of 1000 °C. By contrast, no emitters are activated by annealing in vacuum, oxygen, argon or deuterium. The emitters activated by annealing in forming gas exhibit very bright emission in the 730-760 nm wavelength range and have linewidths of ∼1.5-2.5 nm at room temperature.

  3. Diverse Near-Infrared Resonant Gold Nanostructures for Biomedical Applications

    KAUST Repository

    Huang, Jianfeng

    2015-12-08

    The ability of near-infrared (NIR) light to penetrate tissues deeply and to target malignant sites with high specificity via precise temporal and spatial control of light illumination makes it useful for diagnosing and treating diseases. Owing to their unique biocompatibility, surface chemistry and optical properties, gold nanostructures offer advantages as in vivo NIR photosensitizers. This chapter describes the recent progress in the varied use of NIR-resonant gold nanostructures for NIR-light-mediated diagnostic and therapeutic applications. We begin by describing the unique biological, chemical and physical properties of gold nanostructures that make them excellent candidates for biomedical applications. From here, we make an account of the basic principles involved in the diagnostic and therapeutic applications where gold nanostructures have set foot. Finally, we review recent developments in the fabrication and use of diverse NIR-resonant gold nanostructures for cancer imaging and cancer therapy.

  4. Neuroimaging with functional near infrared spectroscopy: From formation to interpretation

    Science.gov (United States)

    Herrera-Vega, Javier; Treviño-Palacios, Carlos G.; Orihuela-Espina, Felipe

    2017-09-01

    Functional Near Infrared Spectroscopy (fNIRS) is gaining momentum as a functional neuroimaging modality to investigate the cerebral hemodynamics subsequent to neural metabolism. As other neuroimaging modalities, it is neuroscience's tool to understand brain systems functions at behaviour and cognitive levels. To extract useful knowledge from functional neuroimages it is critical to understand the series of transformations applied during the process of the information retrieval and how they bound the interpretation. This process starts with the irradiation of the head tissues with infrared light to obtain the raw neuroimage and proceeds with computational and statistical analysis revealing hidden associations between pixels intensities and neural activity encoded to end up with the explanation of some particular aspect regarding brain function.To comprehend the overall process involved in fNIRS there is extensive literature addressing each individual step separately. This paper overviews the complete transformation sequence through image formation, reconstruction and analysis to provide an insight of the final functional interpretation.

  5. Predicting rapeseed oil content with near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Roberta Rossato

    2013-12-01

    Full Text Available The objective of this work was to establish a calibration equation and to estimate the efficiency of near-infrared reflectance (NIR spectroscopy for evaluating rapeseed oil content in Southern Brazil. Spectral data from 124 half-sib families were correlated with oil contents determined by the chemical method. The accuracy of the equation was verified by coefficient of determination (R² of 0.92, error of calibration (SEC of 0.78, and error of performance (SEP of 1.22. The oil content of ten genotypes, which were not included in the calibration with NIR, was similar to the one obtained by the standard chemical method. NIR spectroscopy is adequate to differentiate oil content of rapeseed genotypes.

  6. Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bwambok, David [Louisiana State University; El-Zahab, Bilal [Lousianna State University; Challa, Santhosh [Louisiana State University; Li, Min [Lousianna State University; Chandler, Lin [Horiba Jobin Yvon Inc.; Baker, Gary A [ORNL; Warner, Isiah M [ORNL

    2009-01-01

    Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

  7. Usefulness of portable near infrared spectroscopy in olive breeding programs

    Energy Technology Data Exchange (ETDEWEB)

    Leon-Moreno, L.

    2012-11-01

    The usefulness of portable near infrared (NIR) spectroscopy as a simple and efficient method to determine some of the main selection traits in olive breeding is evaluated in this work. Calibration models were developed and evaluated using partial least squares (PLS) regression from samples collected in different selection steps of the breeding work and under different experimental conditions. The results showed that accurate enough models (values of correlation between actual and predicted constituent higher than 0.9) were obtained for oil and moisture content in both cross validation and prediction results. Portable NIR spectroscopy could be used for selection of genotypes on the basis of these characters, providing similar ranking of genotypes than reference methods both in different selection steps of the breeding process (progenies and selection plots) and different experimental conditions (on-tree or under laboratory conditions). The advantages of this technique to improve the efficiency of the evaluation process in olive breeding programs are discussed. (Author) 21 refs.

  8. Design of planar chiral metamaterials for near-infrared regime

    Science.gov (United States)

    Kaya, Sabri; Turkmen, Mustafa; Topaktas, Omer

    2017-01-01

    Planar chiral metamaterials (PCMs) comprising double-layer dielectric-metal-dielectric resonant structures in the shape of a windmill are presented for near-infrared regime. The circular dichroism is retrieved from transmission spectra. Effects of used materials on circular dichroism characteristics of PCM arrays are investigated for the first time. The dependence of spectral characteristics on the geometrical parameters of the PCMs is analyzed by the finite-difference time-domain method. The observations indicated that the circular dichroism characteristics of the proposed PCM arrays are strongly dependent on the type of metal and dielectric materials. Due to the enhanced chiroptical near-field response and tunable spectral behavior, proposed PCM arrays may have potential for biosensing applications of chiral biomolecules.

  9. Canopy near-infrared reflectance and terrestrial photosynthesis

    Science.gov (United States)

    Badgley, Grayson; Field, Christopher B.; Berry, Joseph A.

    2017-01-01

    Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIRV). NIRV provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors. NIRV is strongly correlated with solar-induced chlorophyll fluorescence, a direct index of photons intercepted by chlorophyll, and with site-level and globally gridded estimates of GPP. NIRV makes it possible to use existing and future reflectance data as a starting point for accurately estimating GPP.

  10. Near infrared reflectance measurement of nitrogen faecal losses.

    Science.gov (United States)

    Benini, L; Caliari, S; Bonfante, F; Guidi, G C; Brentegani, M T; Castellani, G; Sembenini, C; Bardelli, E; Vantini, I

    1992-06-01

    Chemical methods of measuring nitrogen in stools are complex, unpleasant, and therefore rarely performed. Recently, near infrared reflectance (NIRA) has been suggested for stool analysis. The aim of this study was to evaluate the possible application of this method in routine faecal nitrogen measurement. Nitrogen concentration and daily output were measured in the stools of 83 patients using NIRA and, for comparison, the Kjeldahl method. Nitrogen concentration and output ranged between 0.4-2.72 g% and 0.45-8.96 g/day respectively. Correlation coefficients (r), of 0.89 and 0.97 were found between the two methods for concentration and output respectively, and similar values were found in patients on enteral nutrition. Repeated measurements from the same stool collection, requiring only a few minutes, allowed homogenisation to be avoided. NIRA seems to be an easy, fast, and reliable alternative to chemical assays of nitrogen measurement in the management of patients with digestive disorders.

  11. Near-infrared spectrometric determination of dipyrone in closed ampoules.

    Science.gov (United States)

    Sanches, Fátima Aparecida C; Abreu, Rosimeri B; Pontes, Márcio José Coelho; Leite, Flaviano C; Costa, Daniel Jackson E; Galvão, Roberto Kawakami H; Araujo, Mario Cesar U

    2012-04-15

    The present paper proposes an analytical method for fast near-infrared (NIR) determination of dipyrone in injectable formulations with a nominal content of 50.0%mv(-1) without violation of the ampoule. For this purpose, two multivariate calibration methods are evaluated, namely Partial-Least-Squares (PLS) and Multiple Linear Regression (MLR) with variable selection by the Successive Projections Algorithm (SPA). The resulting models comprised four latent variables (PLS) and five spectral variables (MLR-SPA). Appropriate predictions were obtained in both cases, with RMSEP values of 0.39 (PLS) and 0.35%mv(-1) (MLR-SPA) and correlation coefficients of 0.9970 (PLS) and 0.9975 (MLR-SPA) for a calibration range of 40-60%mv(-1). No systematic error was observed and no significant differences were found between the predicted and reference values, according to a paired t-test at 95% confidence level.

  12. Near-infrared spectroscopy for monitoring muscle oxygenation

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Piantadosi, C A

    2000-01-01

    Near-infrared spectroscopy (NIRS) is a non-invasive method for monitoring oxygen availability and utilization by the tissues. In intact skeletal muscle, NIRS allows semi-quantitative measurements of haemoglobin plus myoglobin oxygenation (tissue O2 stores) and the haemoglobin volume. Specialized...... algorithms allow assessment of the oxidation-reduction (redox) state of the copper moiety (CuA) of mitochondrial cytochrome c oxidase and, with the use of specific tracers, accurate assessment of regional blood flow. NIRS has demonstrated utility for monitoring changes in muscle oxygenation and blood flow...... during submaximal and maximal exercise and under pathophysiological conditions including cardiovascular disease and sepsis. During work, the extent to which skeletal muscles deoxygenate varies according to the type of muscle, type of exercise and blood flow response. In some instances, a strong...

  13. PANIC: A Near-infrared Camera for the Magellan Telescopes

    CERN Document Server

    Martini, P; Murphy, D C; Birk, C; Shectman, S A; Grunnels, S M; Koch, E

    2004-01-01

    PANIC (Persson's Auxiliary Nasmyth Infrared Camera) is a near-infrared camera designed to operate at any one of the f/11 folded ports of the 6.5m Magellan telescopes at Las Campanas Observatory, Chile. The instrument is built around a simple, all-refractive design that reimages the Magellan focal plane to a plate scale of 0.125'' pixel^{-1} onto a Rockwell 1024x1024 HgCdTe detector. The design goals for PANIC included excellent image quality to sample the superb seeing measured with the Magellan telescopes, high throughput, a relatively short construction time, and low cost. PANIC has now been in regular operation for over one year and has proved to be highly reliable and produce excellent images. The best recorded image quality has been ~0.2'' FWHM.

  14. Cylindrical luminescent solar concentrators with near-infrared quantum dots.

    Science.gov (United States)

    Inman, R H; Shcherbatyuk, G V; Medvedko, D; Gopinathan, A; Ghosh, S

    2011-11-21

    We investigate the performance of cylindrical luminescent solar concentrators (CLSCs) with near-infrared lead sulfide quantum dots (QDs) in the active region. We fabricate solid and hollow cylinders from a composite of QDs in polymethylmethacrylate, prepared by radical polymerization, and characterize sample homogeneity and optical properties using spectroscopic techniques. We additionally measure photo-stability and photocurrent outputs under both laboratory and external ambient conditions. The experimental results are in good agreement with theoretical calculations which demonstrate that the hollow CLSCs have higher absorption of incident radiation and lower self-absorption compared to solid cylindrical and planar geometries with similar geometric factors, resulting in a higher optical efficiency. © 2011 Optical Society of America

  15. Near-infrared LIF spectroscopy of HfF

    CERN Document Server

    Grau, Matt; Loh, Huanqian; Sinclair, Laura C; Stutz, Russel P; Yahn, Tylser S; Cornell, Eric A

    2012-01-01

    The molecular ion HfF$^+$ is the chosen species for a JILA experiment to measure the electron electric dipole moment (eEDM). Detailed knowledge of the spectrum of HfF is crucial to prepare HfF$^+$ in a state suitable for performing an eEDM measurement\\cite{Leanhardt}. We investigated the near-infrared electronic spectrum of HfF using laser-induced fluorescence (LIF) of a supersonic molecular beam. We discovered eight unreported bands, and assign each of them unambiguously, four to vibrational bands belonging to the transition $[13.8]0.5 \\leftarrow X1.5$, and four to vibrational bands belonging to the transition $[14.2]1.5 \\leftarrow X1.5$. Additionally, we report an improved measurement of vibrational spacing of the ground state, as well as anharmonicity $\\omega_e x_e$.

  16. Recent advances in fetal near-infrared spectroscopy

    Science.gov (United States)

    D'Antona, Donato; Aldrich, Clive J.; O'Brien, Patrick; Lawrence, Sally; Delpy, David T.; Wyatt, John S.

    1997-01-01

    Fetal brain injury resulting from hypoxia and ischemia during labor remains an important cause of death and long- term disability. However, little is known about fetal brain oxygenation and hemodynamics. There are currently no satisfactory clinical techniques for fetal monitoring and there remains a need for a new method to assess brain oxygenation. Fetal near infrared spectroscopy (NIRS) is a new technique that allows noninvasive observation of changes in the cerebral concentrations of oxyhemoglobin and deoxyhemoglobin to be made during labor. A specially designed optical probe is inserted through the dilated cervix and placed against the fetal head. It is then possible to compare changes in NIRS data with other observations of fetal conditions, such as fetal heart rate and acid-base status.

  17. Near-infrared light responsive polymeric nanocomposites for cancer therapy.

    Science.gov (United States)

    Min, Cong; Zou, Xueqing; Yang, Quanzhu; Liao, Liqiong; Zhou, Guofu; Liu, Lijian

    2016-11-22

    Inorganic nanoparticles, which can absorb and convert near infrared (NIR) light to heat to ablate cancer cells, have been widely investigated in photothermal therapy. However, the inherent poor solubility and acute systemic toxicity of these inorganic particles hinder their application in clinical practice. Polymeric nnanocomposites materials containing both inorganic nanoparticles and polymers could be harnessed to achieve enhanced photothermal therapeutic effect as well as improved biocompatibility and multi-responsiveness. Synergistic chemo-photothermal efficacy towards cancer cells and tumor tissue can thus be realized through such multi-functional and multi-responsive polymeric nanocomposites. In this review, the recent developments in polymeric nanocomposites based on different types of inorganic nanoparticles (i.e. gold, carbon nanotube, graphene, and up-conversion nanoparticles) for NIR-triggered cancer therapy are summarized.

  18. Frequency comb vernier spectroscopy in the near infrared

    CERN Document Server

    Zhu, F; Bicer, A; Strohaber, J; Kolomenskii, A A; Gohle, C; Amani, M; Schuessler, H A

    2014-01-01

    We perform femtosecond frequency comb vernier spectroscopy in the near infrared with a femtosecond Er doped fiber laser, a scanning high-finesse cavity and an InGaAs camera. By utilizing the properties of a frequency comb and a scanning high-finesse cavity such spectroscopy provides broad spectral bandwidth, high spectral resolution, and high detection sensitivity on a short time scale. We achieved an absorption sensitivity of ~8E-8 cm-1Hz-1/2 corresponding to a detection limit of ~70 ppbv for acetylene, with a resolution of ~1.1 GHz in single images taken in 0.5 seconds and covering a frequency range of ~5 THz. These measurements have broad applications for sensing other greenhouse gases in this fingerprint near IR region with a simple apparatus.

  19. Near-Infrared Bulge-Disk Correlations of Lenticular Galaxies

    CERN Document Server

    Barway, Sudhanshu; Kembhavi, Ajit K; Mayya, Y D

    2008-01-01

    We consider the luminosity and environmental dependence of structural parameters of lenticular galaxies in the near-infrared K band. Using a two-dimensional galaxy image decomposition technique, we extract bulge and disk structural parameters for a sample of 36 lenticular galaxies observed by us in the K band. By combining data from the literature for field and cluster lenticulars with our data, we study correlations between parameters that characterise the bulge and the disk as a function of luminosity and environment. We find that scaling relations such as the Kormendy relation, photometric plane and other correlations involving bulge and disk parameters show a luminosity dependence. This dependence can be explained in terms of galaxy formation models in which faint lenticulars (M_T > -24.5) formed via secular formation processes that likely formed the pseudobulges of late-type disk galaxies, while brighter lenticulars (M_T < -24.5) formed through a different formation mechanism most likely involving maj...

  20. Near-infrared extinction with discretised stellar colours

    CERN Document Server

    Juvela, M

    2015-01-01

    Several methods exist to convert near-infrared (NIR) stellar observations into extinction maps. We present a new method based on NIR multiband observations. The method uses a discretised version of the distribution of intrinsic stellar colours. A number of variations of the basic method are tested, and the results are compared to NICER calculations. When photometric errors are large, the results are close to those of NICER method but some advantages can be seen when the distribution of intrinsic colours cannot be described well with a single covariance matrix. A priori information about relative column density variations at sub-beam scales can result in a significant increase in accuracy. The results may be further improved by considering the magnitude dependence of the intrinsic colours. Thus, the new methods are useful mostly when photometric errors are small, the distribution of intrinsic colours is well known, or one has prior knowledge of the small-scale structures.

  1. Discrimination and content analysis of fritillaria using near infrared spectroscopy.

    Science.gov (United States)

    Meng, Yu; Wang, Shisheng; Cai, Rui; Jiang, Bohai; Zhao, Weijie

    2015-01-01

    Fritillaria is a traditional Chinese herbal medicine which can be used to moisten the lungs. The objective of this study is to develop simple, accurate, and solvent-free methods to discriminate and quantify Fritillaria herbs from seven different origins. Near infrared spectroscopy (NIRS) methods are established for the rapid discrimination of seven different Fritillaria samples and quantitative analysis of their total alkaloids. The scaling to first range method and the partial least square (PLS) method are used for the establishment of qualitative and quantitative analysis models. As a result of evaluation for the qualitative NIR model, the selectivity values between groups are always above 2, and the mistaken judgment rate of fifteen samples in prediction sets was zero. This means that the NIR model can be used to distinguish different species of Fritillaria herbs. The established quantitative NIR model can accurately predict the content of total alkaloids from Fritillaria samples.

  2. Near-infrared Spectroscopy in the Brewing Industry.

    Science.gov (United States)

    Sileoni, Valeria; Marconi, Ombretta; Perretti, Giuseppe

    2015-01-01

    This article offers an exhaustive description of the use of Near-Infrared (NIR) Spectroscopy in the brewing industry. This technique is widely used for quality control testing of raw materials, intermediates, and finished products, as well as process monitoring during malting and brewing. In particular, most of the reviewed works focus on the assessment of barley properties, aimed at quickly selecting the best barley varieties in order to produce a high-quality malt leading to high-quality beer. Various works concerning the use of NIR in the evaluation of raw materials, such as barley, malt, hop, and yeast, are also summarized here. The implementation of NIR sensors for the control of malting and brewing processes is also highlighted, as well as the use of NIR for quality assessment of the final product.

  3. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    Science.gov (United States)

    Harrivel, Angela; Hearn, Tristan A.

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in real-time. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors.

  4. Functional near-infrared spectroscopy studies in children

    Directory of Open Access Journals (Sweden)

    Nagamitsu Shinichiro

    2012-03-01

    Full Text Available Abstract Psychosomatic and developmental behavioral medicine in pediatrics has been the subject of significant recent attention, with infants, school-age children, and adolescents frequently presenting with psychosomatic, behavioral, and psychiatric symptoms. These may be a consequence of insecurity of attachment, reduced self-confidence, and peer -relationship conflicts during their developmental stages. Developmental cognitive neuroscience has revealed significant associations between specific brain lesions and particular cognitive dysfunctions. Thus, identifying the biological deficits underlying such cognitive dysfunction may provide new insights into therapeutic prospects for the management of those symptoms in children. Recent advances in noninvasive neuroimaging techniques, and especially functional near-infrared spectroscopy (NIRS, have contributed significant findings to the field of developmental cognitive neuroscience in pediatrics. We present here a comprehensive review of functional NIRS studies of children who have developed normally and of children with psychosomatic and behavioral disorders.

  5. [Rapid determination of beet sugar content using near infrared spectroscopy].

    Science.gov (United States)

    Yang, Yong; Ren, Jian; Zheng, Xi-Qun; Zhao, Li-Ying; Li, Mao-Mao

    2014-10-01

    In order to classify and set different prices on basis of difference of beet sugar content in the acquisition process and promote the development of beet sugar industry healthily, a fast, nondestructive, accurate method to detect sugar content of beet was determined by applying near infrared spectroscopy technology. Eight hundred twenty samples from 28 representative varieties of beet were collected as calibration set and 70 samples were chosen as prediction set. Then near infrared spectra of calibration set samples were collected by scanning, effective information was extracted from NIR spectroscopy, and the original spectroscopy data was optimized by data preprocessing methods appropriately. Then partial least square(PLS)regression was used to establish beet sugar quantitative prediction mathematical model. The performances of the models were evaluated by the root mean square of cross-validation (RMSECV), the coefficient of determination (R2) of the calibration model and the standard error of prediction (SEP), and the predicted results of these models were compared. Results show that the established mathematical model by using first derivative (FD) and standard normal variate transformation (SNV) coupled with partial least squares has good predictive ability. The R2 of calibration models of sugar content of beet is 0.908 3, and the RMSECV is 0.376 7. Using this model to forecast the prediction set including 70 samples, the correlation coefficient is 0.921 4 between predicted values and measured values, and the standard error of prediction (SEP) is 0.439, without significant difference (p > 0.05) between predicted values and measured values. These results demonstrated that NIRS can take advantage of simple, rapid, nondestructive and environmental detection method and could be applied to predict beet sugar content. This model owned high accuracy and can meet the precision need of determination of beet sugar content. This detection method could be used to classify

  6. Near-infrared photoimmunotherapy: a comparison of light dosing schedules.

    Science.gov (United States)

    Ogata, Fusa; Nagaya, Tadanobu; Nakamura, Yuko; Sato, Kazuhide; Okuyama, Shuhei; Maruoka, Yasuhiro; Choyke, Peter L; Kobayashi, Hisataka

    2017-05-23

    Near infrared photoimmunotherapy (NIR-PIT) is a newly-developed cancer therapy in which a monoclonal antibody is conjugated to a near-infrared photoabsorber, IR700 to form an antibody photoabsorber conjugate (APC). After the APC binds to cancer cells expressing the cognate antigen, exposure to NIR light results in rapid, highly selective necrotic cell death of the cancer cells with minimal off-target effects. Several hours after NIR-PIT, the tumor vessels become supraphysiologically permeable and circulating APC can therefore readily leak into the already-treated tumor space where it can bind with viable cancer cells that is called super-enhanced permeability and retention effect. The presence of the SUPR effect after NIR-PIT has prompted regimens in which there is a repeat exposure of NIR light 24 hours after the initial NIR-PIT to take advantage of the leakage of additional APC deeper into the tumor. However, this post-treatment APC penetration was fully induced within 3 hours, therefore, it is possible that repeated exposures of NIR light could be administered much earlier than 24 hours and still produce the same effects. To test this idea, we compared several modes of delivering additional doses of light after initial NIR-PIT. We found that repeated exposures of NIR light starting 3 hours after initial NIR-PIT produced equal or superior results to more delayed exposures of NIR light. This finding has practical implications of an easy-to-perform regimen as repeated light exposures could be performed during a single day rather than extending the procedure over two days which is the current recommendation.

  7. Near-Infrared Coloring via a Contrast-Preserving Mapping Model.

    Science.gov (United States)

    Son, Chang-Hwan; Zhang, Xiao-Ping

    2017-11-01

    Near-infrared gray images captured along with corresponding visible color images have recently proven useful for image restoration and classification. This paper introduces a new coloring method to add colors to near-infrared gray images based on a contrast-preserving mapping model. A naive coloring method directly adds the colors from the visible color image to the near-infrared gray image. However, this method results in an unrealistic image because of the discrepancies in the brightness and image structure between the captured near-infrared gray image and the visible color image. To solve the discrepancy problem, first, we present a new contrast-preserving mapping model to create a new near-infrared gray image with a similar appearance in the luminance plane to the visible color image, while preserving the contrast and details of the captured near-infrared gray image. Then, we develop a method to derive realistic colors that can be added to the newly created near-infrared gray image based on the proposed contrast-preserving mapping model. Experimental results show that the proposed new method not only preserves the local contrast and details of the captured near-infrared gray image, but also transfers the realistic colors from the visible color image to the newly created near-infrared gray image. It is also shown that the proposed near-infrared coloring can be used effectively for noise and haze removal, as well as local contrast enhancement.

  8. A dual-modal magnetic nanoparticle probe for preoperative and intraoperative mapping of sentinel lymph nodes by magnetic resonance and near infrared fluorescence imaging.

    Science.gov (United States)

    Zhou, Zhengyang; Chen, Hongwei; Lipowska, Malgorzata; Wang, Liya; Yu, Qiqi; Yang, Xiaofeng; Tiwari, Diana; Yang, Lily; Mao, Hui

    2013-07-01

    The ability to reliably detect sentinel lymph nodes for sentinel lymph node biopsy and lymphadenectomy is important in clinical management of patients with metastatic cancers. However, the traditional sentinel lymph node mapping with visible dyes is limited by the penetration depth of light and fast clearance of the dyes. On the other hand, sentinel lymph node mapping with radionucleotide technique has intrinsically low spatial resolution and does not provide anatomic details in the sentinel lymph node mapping procedure. This work reports the development of a dual modality imaging probe with magnetic resonance and near infrared imaging capabilities for sentinel lymph node mapping using magnetic iron oxide nanoparticles (10 nm core size) conjugated with a near infrared molecule with emission at 830 nm. Accumulation of magnetic iron oxide nanoparticles in sentinel lymph nodes leads to strong T2 weighted magnetic resonance imaging contrast that can be potentially used for preoperative localization of sentinel lymph nodes, while conjugated near infrared molecules provide optical imaging tracking of lymph nodes with a high signal to background ratio. The new magnetic nanoparticle based dual imaging probe exhibits a significant longer lymph node retention time. Near infrared signals from nanoparticle conjugated near infrared dyes last up to 60 min in sentinel lymph node compared to that of 25 min for the free near infrared dyes in a mouse model. Furthermore, axillary lymph nodes, in addition to sentinel lymph nodes, can be also visualized with this probe, given its slow clearance and sufficient sensitivity. Therefore, this new dual modality imaging probe with the tissue penetration and sensitive detection of sentinel lymph nodes can be applied for preoperative survey of lymph nodes with magnetic resonance imaging and allows intraoperative sentinel lymph node mapping using near infrared optical devices.

  9. A near-infrared SETI experiment: probability distribution of false coincidences

    Science.gov (United States)

    Maire, Jérôme; Wright, Shelley A.; Werthimer, Dan; Treffers, Richard R.; Marcy, Geoffrey W.; Stone, Remington P. S.; Drake, Frank; Siemion, Andrew

    2014-07-01

    A Search for Extraterrestrial Life (SETI), based on the possibility of interstellar communication via laser signals, is being designed to extend the search into the near-infrared spectral region (Wright et al, this conference). The dedicated near-infrared (900 to 1700 nm) instrument takes advantage of a new generation of avalanche photodiodes (APD), based on internal discrete amplification. These discrete APD (DAPD) detectors have a high speed response (laser light pulse detection in our experiment. These criteria are defined to optimize the trade between high detection efficiency and low false positive coincident signals, which can be produced by detector dark noise, background light, cosmic rays, and astronomical sources. We investigate experimentally how false coincidence rates depend on the number of detectors in parallel, and on the signal pulse height and width. We also look into the corresponding threshold to each of the signals to optimize the sensitivity while also reducing the false coincidence rates. Lastly, we discuss the analytical solution used to predict the probability of laser pulse detection with multiple detectors.

  10. Chromatic aberration correction of the human eye for retinal imaging in the near infrared.

    Science.gov (United States)

    Fernández, Enrique J; Unterhuber, Angelika; Povazay, Boris; Hermann, Boris; Artal, Pablo; Drexler, Woflgang

    2006-06-26

    An achromatizing lens has been designed for the human eye in the near infrared range, from 700 to 900 nm, for retinal imaging purposes. Analysis of the performance of the lens, including tolerance to misalignments, has been mathematically accomplished by using an existing eye model. The calculations have shown a virtually perfect correction of the ocular longitudinal chromatic aberration, while still keeping a high optical quality. Ocular aberrations in five subjects have been measured with and without the achromatizing lens by using a Hartmann-Shack wavefront sensor and a broad bandwidth femtosecond Ti:sapphire laser in the spectral range of interest with a set of interference filters, studying the benefits and limits in the use of the achromatizing lens. Ocular longitudinal chromatic aberration has been experimentally demonstrated to be fully corrected by the proposed lens, with no induction of any other parasitic aberration. The practical implementation of the achromatizing lens for Ophthalmoscopy, specifically for optical coherence tomography where the use of polychromatic light sources in the near infrared portion of the spectrum is mandatory, has been considered. The potential benefits of using this lens in combination with adaptive optics to achieve a full aberration correction of the human eye for retinal imaging have also been discussed.

  11. Rapid discrimination of main red meat species based on near-infrared hyperspectral imaging technology

    Science.gov (United States)

    Qiao, Lu; Peng, Yankun; Chao, Kuanglin; Qin, Jianwei

    2016-05-01

    Meat is the necessary source of essential nutrients for people including protein, fat, and so on. The discrimination of meat species and the determination of meat authenticity have been an important issue in the meat industry. The objective of this study is to realize the fast and accurate identification of three main red meats containing beef, lamb and pork by using near-infrared hyperspectral imaging (HSI) technology. After acquiring the hyperspectral images of meat samples, the calibration of acquired images and selection of the region of interest (ROI) were carried out. Then spectral preprocessing method of standard normal variate correction (SNV) was used to reduce the light scattering and random noise before the spectral analysis. Finally, characteristic wavelengths were extracted by principal component analysis (PCA), and the Fisher linear discriminant method was applied to establish Fisher discriminant functions to identify the meat species. All the samples were collected from different batches in order to improve the coverage of the models. In addition to the validation of sample itself in train set and cross validation, three different meat samples were sliced at the size of 2cm×2cm×2 cm approximately and were spliced together in one interface to be scanned by HSI system. The acquired hyperspectral data was applied to further validate the discriminant model. The results demonstrated that the near-infrared hyperspectral imaging technology could be applied as an effective, rapid and non-destructive discrimination method for main red meats.

  12. Application of liposome-encapsulated ceramic phoshpors for cancer cell imaging under near infrared excitation

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Hirotada; Otsuka, Hiroko; Tashiro, Fumio [Department of Biological Science and Technology, Tokyo University of Science (Japan); Tokuzen, Kimikazu; Soga, Kohei, E-mail: hakiyama@rs.noda.tus.ac.j [Polyscale Technology Research Center, Tokyo University of Science (Japan)

    2010-06-01

    Bioimaging with fluorescent probes is used as an invaluable tool in a biomedical field both in vivo and in vitro. However, organic dyes have some problems such as photo-breaching and cytotoxicity due to short wavelength with high quantum energy. Recently, a new approach using rare-earth-doped ceramic nanophosphors (RED-CNP) shows that fluorescence from RED-CNP in both visible (upconversion) and near infrared (NIR) wavelength region under NIR excitation is available for bioimaging. In order to efficiently introduce the RED-CNP into cancer cells, in this study we have developed a lipid nano-particles of liposome-encapsulated erbium (Er) ion-doped Y{sub 2}O{sub 3} (lipo-Y{sub 2}O{sub 3}). Cationic lipo-Y{sub 2}O{sub 3} could clearly visualize the intracellular region of human hepatocellular carcinoma Huh-7 cells by a fluorescence microscope measurements equipped with near-infrared excitation source scanning. The results imply that the lipo-Y{sub 2}O{sub 3} would potentially be useful material for imaging of cancer cells. The embedded Y{sub 2}O{sub 3} in the liposome having cancer-specific ligands and/or antibodies on its surface should have a great potential for cancer cell imaging in general in living subjects.

  13. Near-Infrared Photometry of the Type IIn SN 2005ip: The Case for Dust Condensation

    CERN Document Server

    Fox, Ori; Chevalier, Roger A; Kanneganti, Srikrishna; Park, Chan; Wilson, John; Nelson, Matthew; Amirhadji, Jason; Crump, Danielle; Hoeft, Alexi; Provence, Sydney; Sargeant, Benjamin; Sop, Joel; Tea, Matthew; Thomas, Steven; Woolard, Kyle

    2008-01-01

    Near-infrared photometric observations of the Type IIn SN 2005ip in NGC 2906 reveal large fluxes (>1.3 mJy) in the K_s-band over more than 900 days. While warm dust can explain the late-time K_s-band emission of SN 2005ip, the nature of the dust heating source is ambiguous. Shock heating of pre-existing dust by post-shocked gas is unlikely because the forward shock is moving too slowly to have traversed the expected dust-free cavity by the time observations first reveal the K_s emission. While an infrared light echo correctly predicts a near-infrared luminosity plateau, heating dust to the observed temperatures of ~1400-1600 K at a relatively large distance from the supernova (\\ga 10^{18} cm) requires an extraordinarily high early supernova luminosity (~1 X 10^{11} L_sun). The evidence instead favors condensing dust in the cool, dense shell between the forward and reverse shocks. Both the initial dust temperature and the evolutionary trend towards lower temperatures are consistent with this scenario. We infer...

  14. Development of a near-infrared spectroscopy instrument for applications in urology.

    Science.gov (United States)

    Macnab, Andrew J; Stothers, Lynn

    2008-10-01

    Near infrared spectroscopy (NIRS) is an established technology using photons of light in the near infrared spectrum to monitor changes in tissue of naturally occurring chromophores, including oxygenated and deoxygenated hemoglobin. Technology and methodology have been validated for measurement of a range of physiologic parameters. NIRS has been applied successfully in urology research; however current instruments are designed principally for brain and muscle study. To describe development of a NIRS instrument specifically designed for monitoring changes in chromophore concentration in the bladder detrusor in real time, to facilitate research to establish the role of this non-invasive technology in the evaluation of patients with voiding dysfunction The portable continuous wave NIRS instrument has a 3 laser diode light source (785, 808 and 830 nanometers), fiber optic cables for light transmission, a self adhesive patient interface patch with an emitter and sensor, and software to detect the difference between the light transmitted and received by the instrument. Software incorporated auto-attenuates the optical signals and converts raw optical data into chromophore concentrations displayed graphically. The prototype was designed, tested, and iteratively developed to achieve optimal suprapubic transcutaneous monitoring of the detrusor in human subjects during bladder filling and emptying. Evaluation with simultaneous invasive urodynamic measurement in men and women indicates good specificity and sensitivity of NIRS chromophore concentration changes by receiver operator curve analysis, and correlation between NIRS data and urodynamic pressures. Urological monitoring with this NIRS instrument is feasible and generates data of potential diagnostic value.

  15. Absolute near-infrared refractometry with a calibrated tilted fiber Bragg grating.

    Science.gov (United States)

    Zhou, Wenjun; Mandia, David J; Barry, Seán T; Albert, Jacques

    2015-04-15

    The absolute refractive indices (RIs) of water and other liquids are determined with an uncertainty of ±0.001 at near-infrared wavelengths by using the tilted fiber Bragg grating (TFBG) cladding mode resonances of a standard single-mode fiber to measure the critical angle for total internal reflection at the interface between the fiber and its surroundings. The necessary condition to obtain absolute RIs (instead of measuring RI changes) is a thorough characterization of the dispersion of the core mode effective index of the TFBG across the full range of its cladding mode resonance spectrum. This technique is shown to be competitive with the best available measurements of the RIs of water and NaCl solutions at wavelengths in the vicinity of 1550 nm.

  16. A near-infrared magnetic aptasensor for Ochratoxin A based on near-infrared upconversion nanoparticles and magnetic nanoparticles.

    Science.gov (United States)

    Dai, Shaoliang; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2016-09-01

    A multiplexed, sensitive and specific detection method is highly desirable for the simultaneous detection of several pathogenic bacteria and bio-toxins. In our previous work, multicolor upconversion nanoparticles (UCNPs) via doping with various rare-earth ions to obtain well-separated emission peaks by means of a solvothermal method were synthesized and were successfully applied as luminescence labels in the detection of three pathogenic bacteria. One of the basic achievements of our group has been to establish that the key to increasing the number of simultaneous detection components is the preparation of more UCNPs, the emission peaks of which can be distinguished from each other. According to this vision, NaYF4:Yb0.2, Tm0.02 UCNPs were obtained via a thermal-decomposition protocol, which has a main near-infrared (NIR) UC emission at 804nm under 980nm excitation. The emission peak at 804nm was well-separated from the emission peaks of UCNPs we have reported at 477nm, 542nm, and 660nm. It means both the excitation and the emission of NaYF4:Yb0.2, Tm0.02 UCNPs are located in the NIR spectral range (NIR-to-NIR UC emission), the so-called biological window. This result establishes the basis of achieving simultaneous detection of four components. To confirm the analytical performance of this NaYF4:Yb0.2, Tm0.02 UCNPs, a novel near-infrared magnetic aptasensor for the detection of Ochratoxin A (OTA) was developed using the OTA aptamer-conjugated near-infrared upconversion nanoparticles (apt-UCNPs) and the complementary oligonucleotide-modified magnetic nanoparticles (cDNA-MNPs). The apt-UCNPs and cDNA-MNPs were hybridized to form a poly-network structure of MNP-UCNP nanocomposites. When the target OTA was introduced, the aptamer combined with the priority target and the cDNA-MNPs were replaced. The proposed method achieved a linear range between 0.01 and 100ngmL(-1), with a detection limit as low as 0.005ngmL(-1). Then, we successfully applied this method to measure

  17. A near-infrared survey of the OMC2 region

    Science.gov (United States)

    Jones, Terry Jay; Mergen, John; Odewahn, Steve; Gehrz, Robert D.; Gatley, I.; Merrill, K. M.; Probst, R.; Woodward, C. E.

    1994-01-01

    We present an unbiased survey at 1.25-2.2 micrometers of a 0.025 sq. deg. region surrounding the core of Orion Molecular Cloud 2 (OMC-2). Analysis of the source counts and colors indicates that the majority of the sources brighter than K = +13 are not field stars. They must be members of a young association or associations within the survey area. The K band luminosity function (corrected for field star contamination using model calculations) exhibits a drop in counts at magnitudes fainter than K = +13 (approximately 0.15 solar luminosity). This is most easily explained by assuming that the association(s) are young. The lowest mass stars simply have not yet reached the main sequence. The distribution of colors across the region shows moderate correlation with molecular gas, but both reddened and unreddened stars are present along most lines of sight. Considerable reflection nebulosity is present in the region of the core cluster of OMC2 itself. Of particular interest are the thin streamers emanating from the star J9, which may be the remnant of a bipolar nebula produced by the star in the recent past.

  18. A near-infrared survey of the OMC2 region

    Science.gov (United States)

    Jones, Terry Jay; Mergen, John; Odewahn, Steve; Gehrz, Robert D.; Gatley, I.; Merrill, K. M.; Probst, R.; Woodward, C. E.

    1994-01-01

    We present an unbiased survey at 1.25-2.2 micrometers of a 0.025 sq. deg. region surrounding the core of Orion Molecular Cloud 2 (OMC-2). Analysis of the source counts and colors indicates that the majority of the sources brighter than K = +13 are not field stars. They must be members of a young association or associations within the survey area. The K band luminosity function (corrected for field star contamination using model calculations) exhibits a drop in counts at magnitudes fainter than K = +13 (approximately 0.15 solar luminosity). This is most easily explained by assuming that the association(s) are young. The lowest mass stars simply have not yet reached the main sequence. The distribution of colors across the region shows moderate correlation with molecular gas, but both reddened and unreddened stars are present along most lines of sight. Considerable reflection nebulosity is present in the region of the core cluster of OMC2 itself. Of particular interest are the thin streamers emanating from the star J9, which may be the remnant of a bipolar nebula produced by the star in the recent past.

  19. Radio sources near the core of globular cluster 47 Tucanae

    CERN Document Server

    McConnell, D

    1999-01-01

    We present ATCA radio images of the globular cluster 47 Tucanae made at 1.4and 1.7 GHz and provide an analysis of the radio sources detected within 5arcmin of the cluster centre. 11 sources are detected, most of which areclustered about the core of 47 Tuc. Both of the pulsars in 47 Tuc whosepositions are known can be identified with sources in the 1.4 GHz image. Thesource distribution has a characteristic radius of ~100 arcsec, larger than the23 arcsec radius of the cluster core. We compare source positions with thepositions of nine X-ray sources and find no correspondence.

  20. Enhanced near-infrared photoacoustic imaging of silica-coated rare-earth doped nanoparticles.

    Science.gov (United States)

    Sheng, Yang; Liao, Lun-De; Bandla, Aishwarya; Liu, Yu-Hang; Yuan, Jun; Thakor, Nitish; Tan, Mei Chee

    2017-01-01

    Near-infrared photoacoustic (PA) imaging is an emerging diagnostic technology that utilizes the tissue transparent window to achieve improved contrast and spatial resolution for deep tissue imaging. In this study, we investigated the enhancement effect of the SiO2 shell on the PA property of our core/shell rare-earth nanoparticles (REs) consisting of an active rare-earth doped core of NaYF4:Yb,Er (REDNPs) and an undoped NaYF4 shell. We observed that the PA signal amplitude increased with SiO2 shell thickness. Although the SiO2 shell caused an observed decrease in the integrated fluorescence intensity due to the dilution effect, fluorescence quenching of the rare earth emitting ions within the REDNPs cores was successfully prevented by the undoped NaYF4 shell. Therefore, our multilayer structure consisting of an active core with successive functional layers was demonstrated to be an effective design for dual-modal fluorescence and PA imaging probes with improved PA property. The result from this work addresses a critical need for the development of dual-modal contrast agent that advances deep tissue imaging with high resolution and signal-to-noise ratio. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Non-thermal DNA damage of cancer cells using near-infrared irradiation.

    Science.gov (United States)

    Tanaka, Yohei; Tatewaki, Naoto; Nishida, Hiroshi; Eitsuka, Takahiro; Ikekawa, Nobuo; Nakayama, Jun

    2012-08-01

    Previously, we reported that near-infrared irradiation that simulates solar near-infrared irradiation with pre- and parallel-irradiational cooling can non-thermally induce cytocidal effects in cancer cells. To explore these effects, we assessed cell viability, DNA damage response pathways, and the percentage of mitotic cancer cells after near-infrared treatment. Further, we evaluated the anti-cancer effects of near-infrared irradiation compared with doxorubicin in xenografts in nude mice by measuring tumor volume and assessing protein phosphorylation by immunoblot analysis. The cell viability of A549 lung adenocarcinoma cells was significantly decreased after three rounds of near-infrared irradiation at 20 J/cm(2). Apoptotic cells were observed in near-infrared treated cells. Moreover, near-infrared treatment increased the phosphorylation of ataxia-telangiectasia mutated (ATM) at Ser(1981), H2AX at Ser(139), Chk1 at Ser(317), structural maintenance of chromosome (SMC) 1 at Ser(966), and p53 at Ser(15) in A549 cells compared with control. Notably, near-infrared treatment induced the formation of nucleic foci of γH2AX. The percentage of mitotic A549 cells, as measured by histone H3 phosphorylation, decreased significantly after three rounds of near-infrared irradiation at 20 J/cm(2). Both near-infrared and doxorubicin inhibited the tumor growth of MDA-MB435 melanoma cell xenografts in nude mice and increased the phosphorylation of p53 at Ser(15), Chk1 at Ser(317), SMC1 at Ser(966), and H2AX at Ser(139) compared with control mice. These results indicate that near-infrared irradiation can non-thermally induce cytocidal effects in cancer cells as a result of activation of the DNA damage response pathway. The near-infrared irradiation schedule used here reduces discomfort and side effects. Therefore, this strategy may have potential application in the treatment of cancer.

  2. Analysis of Leucaena mimosine, Acacia tannins and total phenols by near infrared reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M.N.V. [Hyderabad Univ. (India). Dept. of Plant Sciences

    1995-11-01

    The mimosine contents of Leucaena foliage, Acacia tannins and total phenols from leaf, bark and pod were analyzed by a near infrared relectance spectrophotometer (Compscan 3000). A calibration equation (linear summation regression) was developed with near infrared spectral analysis software, using 30 spectra from old and young leaves of Leucaena and 23 spectra from different samples of Acacia. The near infrared analyzer calculated that the percentages of mimosine, total phenols and tannins are closely comparable to laboratory results. (author)

  3. Gratings and Random Reflectors for Near-Infrared PIN Diodes

    Science.gov (United States)

    Gunapala, Sarath; Bandara, Sumith; Liu, John; Ting, David

    2007-01-01

    Crossed diffraction gratings and random reflectors have been proposed as means to increase the quantum efficiencies of InGaAs/InP positive/intrinsic/ negative (PIN) diodes designed to operate as near-infrared photodetectors. The proposal is meant especially to apply to focal-plane imaging arrays of such photodetectors to be used for near-infrared imaging. A further increase in quantum efficiency near the short-wavelength limit of the near-infrared spectrum of such a photodetector array could be effected by removing the InP substrate of the array. The use of crossed diffraction gratings and random reflectors as optical devices for increasing the quantum efficiencies of quantum-well infrared photodetectors (QWIPs) was discussed in several prior NASA Tech Briefs articles. While the optical effects of crossed gratings and random reflectors as applied to PIN photodiodes would be similar to those of crossed gratings and random reflectors as applied to QWIPs, the physical mechanisms by which these optical effects would enhance efficiency differ between the PIN-photodiode and QWIP cases: In a QWIP, the multiple-quantum-well layers are typically oriented parallel to the focal plane and therefore perpendicular or nearly perpendicular to the direction of incidence of infrared light. By virtue of the applicable quantum selection rules, light polarized parallel to the focal plane (as normally incident light is) cannot excite charge carriers and, hence, cannot be detected. A pair of crossed gratings or a random reflector scatters normally or nearly normally incident light so that a significant portion of it attains a component of polarization normal to the focal plane and, hence, can excite charge carriers. A pair of crossed gratings or a random reflector on a PIN photodiode would also scatter light into directions away from the perpendicular to the focal plane. However, in this case, the reason for redirecting light away from the perpendicular is to increase the length of the

  4. Intraoperative near-infrared fluorescent imaging during robotic operations.

    Science.gov (United States)

    Macedo, Antonio Luiz de Vasconcellos; Schraibman, Vladimir

    2016-01-01

    The intraoperative identification of certain anatomical structures because they are small or visually occult may be challenging. The development of minimally invasive surgery brought additional difficulties to identify these structures due to the lack of complete tactile sensitivity. A number of different forms of intraoperative mapping have been tried. Recently, the near-infrared fluorescence imaging technology with indocyanine green has been added to robotic platforms. In addition, this technology has been tested in several types of operations, and has advantages such as safety, low cost and good results. Disadvantages are linked to contrast distribution in certain clinical scenarios. The intraoperative near-infrared fluorescent imaging is new and promising addition to robotic surgery. Several reports show the utility of this technology in several different procedures. The ideal dose, time and site for dye injection are not well defined. No high quality evidence-based comparative studies and long-term follow-up outcomes have been published so far. Initial results, however, are good and safe. RESUMO A identificação intraoperatória de certas estruturas anatômicas, por seu tamanho ou por elas serem ocultas à visão, pode ser desafiadora. O desenvolvimento da cirurgia minimamente invasiva trouxe dificuldades adicionais, pela falta da sensibilidade tátil completa. Diversas formas de detecção intraoperatória destas estruturas têm sido tentadas. Recentemente, a tecnologia de fluorescência infravermelha com verde de indocianina foi associada às plataformas robóticas. Além disso, essa tecnologia tem sido testada em uma variedade de cirurgias, e suas vantagens parecem estar ligadas a baixo custo, segurança e bons resultados. As desvantagens estão associadas à má distribuição do contraste em determinados cenários. A imagem intraoperatória por fluorescência infravermelha é uma nova e promissora adição à cirurgia robótica. Diversas séries mostram

  5. Single Si nanowire (diameter ≤ 100 nm) based polarization sensitive near-infrared photodetector with ultra-high responsivity.

    Science.gov (United States)

    Das, K; Mukherjee, S; Manna, S; Ray, S K; Raychaudhuri, A K

    2014-10-01

    We report the fabrication and optical response of boron-doped single silicon nanowire-based metal-semiconductor-metal photodetector. Typical single nanowire devices with diameter of ∼80-100 nm and electrode spacing of ∼1 μm were made using electron-beam lithography from nanowires, grown by a metal-assisted chemical etching process. A high responsivity, of the order of 10(4) A W(-1), was observed even at zero bias in a single nanowire photodetector with peak responsivity in the near-infrared region. The responsivity was found to increase with increasing bias and decreasing nanowire diameter. Finite element based optical simulation was proposed to explain the diameter dependent performance of a single nanowire. The observed photoresponse is sensitive to the polarization of exciting light source, allowing the device to act as a polarization-dependent near-infrared photodetector.

  6. Near-infrared autofluorescence for the detection of parathyroid glands

    Science.gov (United States)

    Paras, Constantine; Keller, Matthew; White, Lisa; Phay, John; Mahadevan-Jansen, Anita

    2011-06-01

    A major challenge in endocrine surgery is the intraoperative detection of parathyroid glands during both thyroidectomies and parathyroidectomies. Current localization techniques such as ultrasound and sestamibi scan are mostly preoperative and rely on an abnormal parathyroid for its detection. In this paper, we present near-infrared (NIR) autofluorescence as a nonintrusive, real-time, automated in vivo method for the detection of the parathyroid gland. A pilot in vivo study was conducted to assess the ability of NIR fluorescence to identify parathyroid glands during thyroid and parathyroidectomies. Fluorescence measurements at 785 nm excitation were obtained intra-operatively from the different tissues exposed in the neck region in 21 patients undergoing endocrine surgery. The fluorescence intensity of the parathyroid gland was found to be consistently greater than that of the thyroid and all other tissues in the neck of all patients. In particular, parathyroid fluorescence was two to eleven times higher than that of the thyroid tissues with peak fluorescence occurring at 820 to 830 nm. These results indicate that NIR fluorescence has the potential to be an excellent optical tool to locate parathyroid tissue during surgery.

  7. Near-infrared absolute magnitudes of Type Ia Supernovae

    Science.gov (United States)

    Avelino, Arturo; Friedman, Andrew S.; Mandel, Kaisey; Kirshner, Robert; Challis, Peter

    2017-01-01

    Type Ia Supernovae light curves (SN Ia) in the near infrared (NIR) exhibit low dispersion in their peak luminosities and are less vulnerable to extinction by interstellar dust in their host galaxies. The increasing number of high quality NIR SNe Ia light curves, including the recent CfAIR2 sample obtained with PAIRITEL, provides updated evidence for their utility as standard candles for cosmology. Using NIR YJHKs light curves of ~150 nearby SNe Ia from the CfAIR2 and CSP samples, and from the literature, we determine the mean value and dispersion of the absolute magnitude in the range between -10 to 50 rest-frame days after the maximum luminosity in B band. We present the mean light-curve templates and Hubble diagram for YJHKs bands. This work contributes to a firm local anchor for supernova cosmology studies in the NIR which will help to reduce the systematic uncertainties due to host galaxy dust present in optical-only studies. This research is supported by NSF grants AST-156854, AST-1211196, Fundacion Mexico en Harvard, and CONACyT.

  8. Broadband near-infrared tomography for breast cancer imaging

    Science.gov (United States)

    Wang, Jia

    Near-infrared (NIR) light provides potential for a new approach to non-invasive detection, diagnosis and clinical management of breast cancer. Using NIR spectroscopic imaging techniques, the physiological information about breast tissue composition can be quantitatively estimated, including hemoglobin, water and lipid concentrations, together with scattering properties. In this thesis work, strategies to improve the accuracy of NIR imaging have been explored experimentally and numerically. A novel Ti:Sapphire laser-based frequency domain tomography system was developed to achieve maximum spectral information, using intrinsic phase-locked detection of the signal propagation. The improvement in quantification through addition of more wavelengths was demonstrated in simulations and in tissue-phantom experiments. A hybrid NIR tomography system combining frequency domain and continuous wave spectroscopy approaches was implemented for imaging healthy subjects and women with malignant breast tumors. Adding measurements at wavelengths above 850nm with the continuous wave method significantly improved the accuracy of water and lipid estimation. When used in cancer imaging in vivo, the NIR contrast information is consistent with physiological and pathological values expected in tumor as seen by investigational studies with Magnetic Resonance Imaging (MRI) and pathology analysis.

  9. Near-infrared spectroscopy is feasible to discriminate hazelnut cultivars

    Directory of Open Access Journals (Sweden)

    Elisabetta Stella

    2013-09-01

    Full Text Available The study demonstrated the feasibility of the near infrared (NIR spectroscopy use for hazelnut-cultivar sorting. Hazelnut spectra were acquired from 600 fruit for each cultivar sample, two diffuse reflectance spectra were acquired from opposite sides of the same hazelnut. Spectral data were transformed into absorbance before the computations. A different variety of spectral pretreatments were applied to extract characteristics for the classification. An iterative Linear Discriminant Analysis (LDA algorithm was used to select a relatively small set of variables to correctly classify samples. The optimal group of features selected for each test was analyzed using Partial Least Squares Discriminant Analysis (PLS-DA. The spectral region most frequently chosen was the 1980-2060 nm range, which corresponds to best differentiation performance for a total minimum error rate lower than 1.00%. This wavelength range is generally associated with stretching and bending of the N-H functional group of amino acids and proteins. The feasibility of using NIR Spectroscopy to distinguish different hazelnut cultivars was demonstrated.

  10. Moisture influence on near-infrared prediction of wheat hardness

    Science.gov (United States)

    Windham, William R.; Gaines, Charles S.; Leffler, Richard G.

    1991-02-01

    Recently near infrared (NTR) reflectance instrumentation has been used to provide an empirical measure of wheat hardness. This hardness scale is based on the radiation scattering properties of meal particles at 1680 and 2230 nm. Hard wheats have a larger mean particles size (PS) after grinding than soft wheats. However wheat kernel moisture content can influence mean PS after grinding. The objective of this study was to determine the sensitivity of MR wheat hardness measurements to moisture content and to make the hardness score independent of moisture by correcting hardness measurements for the actual moisture content of measured samples. Forty wheat cultivars composed of hard red winter hard red spring soft red winter and soft white winter were used. Wheat kernel subsamples were stored at 20 40 60 and 80 relative humidity (RH). After equilibration samples were ground and the meal analyzed for hardness score (HS) and moisture. HS were 48 50 54 and 65 for 20 40 60 and 80 RH respectively. Differences in HS within each wheat class were the result of a moisture induced change in the PS of the meal. An algorithm was developed to correct HS to 11 moisture. This correction provides HS that are nearly independent of moisture content. 1.

  11. Electro-optic sampling of near-infrared waveforms

    Science.gov (United States)

    Keiber, Sabine; Sederberg, Shawn; Schwarz, Alexander; Trubetskov, Michael; Pervak, Volodymyr; Krausz, Ferenc; Karpowicz, Nicholas

    2016-03-01

    Access to the complete electric field evolution of a laser pulse is essential for attosecond science in general, and for the scrutiny and control of electron phenomena in solid-state physics specifically. Time-resolved field measurements are routine in the terahertz spectral range, using electro-optic sampling (EOS), photoconductive switches and field-induced second harmonic generation. EOS in particular features outstanding sensitivity and ease of use, making it the basis of time-resolved spectroscopic measurements for studying charge carrier dynamics and active optical devices. In this Letter, we show that careful optical filtering allows the bandwidth of this technique to be extended to wavelengths as short as 1.2 μm (230 THz) with half-cycle durations 2.3 times shorter than the sampling pulse. In a proof-of-principle application, we measure the influence of optical parametric amplification (OPA) on the electric field dynamics of a few-cycle near-infrared (NIR) pulse.

  12. Near-Infrared Variability in the Orion Nebula Cluster

    CERN Document Server

    Rice, Thomas S; Wolk, Scott J; Vaz, Luiz Paolo; Cross, N J G

    2015-01-01

    Using the United Kingdom Infrared Telescope on Mauna Kea, we have carried out a new near-infrared J, H, K monitoring survey of almost a square degree of the star-forming Orion Nebula Cluster with observations on 120 nights over three observing seasons, spanning a total of 894 days. We monitored ~15,000 stars down to J=20 using the WFCAM instrument, and have extracted 1203 significantly variable stars from our data. By studying variability in young stellar objects (YSOs) in the H-K, K color-magnitude diagram, we are able to distinguish between physical mechanisms of variability. Many variables show color behavior indicating either dust-extinction or disk/accretion activity, but we find that when monitored for longer periods of time, a number of stars shift between these two variability mechanisms. Further, we show that the intrinsic timescale of disk/accretion variability in young stars is longer than that of dust-extinction variability. We confirm that variability amplitude is statistically correlated with ev...

  13. Transcranial doppler and near infrared spectroscopy in the perioperative period.

    Science.gov (United States)

    Kampf, Stephanie; Schramm, Patrick; Klein, Klaus Ulrich

    2013-10-01

    Maintenance of adequate blood flow and oxygen to the brain is one of the principal endpoints of all surgery and anesthesia. During operations in general anesthesia, however, the brain is at particular risk for silent ischemia. Despite this risk, the brain still remains one of the last monitored organs in clincial anesthesiology. Transcranial Doppler (TCD) sonography and near-infrared spectroscopy (NIRS) experience a revival as these noninvasive technologies help to detect silent cerebral ischemia. TCD allows for quantification of blood flow velocities in basal intracranial arteries. TCD-derived variables such as the pulsatility index might hint toward diminished cognitive reserve or raised intracranial pressure. NIRS allows for assessment of regional cerebral oxygenation. Monitoring should be performed during high-risk surgery for silent cerebral ischemia and special circumstances during critical care medicine. Both techniques allow for the assessment of cerebrovascular autoregulation and individualized management of cerebral hemodynamics. TCD and NIRS are noninvasive monitors that anesthesiologists apply to tailor cerebral oxygen delivery, aiming to safeguard brain function in the perioperative period.

  14. Adaptive optics near infrared integral field spectroscopy of NGC 2992

    CERN Document Server

    Friedrich, S; Hicks, E K S; Engel, H; Müller-Sánchez, F; Genzel, R; Tacconi, L J

    2010-01-01

    NGC 2992 is an intermediate Seyfert 1 galaxy showing outflows on kilo parsec scales which might be due either to AGN or starburst activity. We therefore aim at investigating its central region for a putative starburst in the past and its connection to the AGN and the outflows. Observations were performed with the adaptive optics near infrared integral field spectrograph SINFONI on the VLT, complemented by longslit observations with ISAAC on the VLT, as well as N- and Q-band data from the Spitzer archive. The spatial and spectral resolutions of the SINFONI data are 50 pc and 83 km/s, respectively. The field of view of 3" x 3" corresponds to 450 pc x 450 pc. Br_gamma equivalent width and line fluxes from PAHs were compared to stellar population models to constrain the age of the putative recent star formation. A simple geometric model of two mutually inclined disks and an additional cone to describe an outflow was developed to explain the observed complex velocity field in H_2 1-0S(1). The morphologies of the B...

  15. IRDye78 Conjugates for Near-Infrared Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Atif Zaheer

    2002-10-01

    Full Text Available The detection of human malignancies by near-infrared (NIR fluorescence will require the conjugation of cancer-specific ligands to NIR fluorophores that have optimal photoproperties and pharmacokinetics. IRDye78, a tetra-sulfonated heptamethine indocyanine NIR fluorophore, meets most of the criteria for an in vivo imaging agent, and is available as an N-hydroxysuccinimide ester for conjugation to low-molecular-weight ligands. However, IRDye78 has a high charge-to-mass ratio, complicating purification of conjugates. It also has a potentially labile linkage between fluorophore and ligand. We have developed an ion-pairing purification strategy for IRDye78 that can be performed with a standard C18 column under neutral conditions, thus preserving the stability of fluorophore, ligand, and conjugate. By employing parallel evaporative light scatter and absorbance detectors, all reactants and products are identified, and conjugate purity is maximized. We describe reversible and irreversible conversions of IRDye78 that can occur during sample purification, and describe methods for preserving conjugate stability. Using seven ligands, spanning several classes of small molecules and peptides (neutral, charged, and/or hydrophobic, we illustrate the robustness of these methods, and confirm that IRDye78 conjugates so purified retain bioactivity and permit NIR fluorescence imaging of specific targets.

  16. Rapid analysis of Radix puerariae by near-infrared spectroscopy.

    Science.gov (United States)

    Lau, Ching-Ching; Chan, Chi-On; Chau, Foo-Tim; Mok, Daniel Kam-Wah

    2009-03-13

    A new, rapid analytical method using near-infrared spectroscopy (NIRS) was developed to differentiate two species of Radix puerariae (GG), Pueraria lobata (YG) and Pueraria thomsonii (FG), and to determine the contents of puerarin, daidzin and total isoflavonoid in the samples. Five isoflavonoids, puerarin, daidzin, daidzein, genistin and genistein were analyzed simultaneously by high-performance liquid chromatography-diode array detection (HPLC-DAD). The total isoflavonoid content was exploited as critical parameter for successful discrimination of the two species. Scattering effect and baseline shift in the NIR spectra were corrected and the spectral features were enhanced by several pre-processing methods. By using linear discriminant analysis (LDA) and soft independent modeling class analogy (SIMCA), samples were separated successfully into two different clusters corresponding to the two GG species. Furthermore, sensitivity and specificity of the classification models were determined to evaluate the performance. Finally, partial least squares (PLS) regression was used to build the correlation models. The results showed that the correlation coefficients of the prediction models are R=0.970 for the puerarin, R=0.939 for daidzin and R=0.969 for total isoflavonoid. The outcome showed that NIRS can serve as routine screening in the quality control of Chinese herbal medicine (CHM).

  17. Near-Infrared Spectroscopy for the Evaluation of Anesthetic Depth

    Directory of Open Access Journals (Sweden)

    Gabriela Hernandez-Meza

    2015-01-01

    Full Text Available The standard-of-care guidelines published by the American Society of Anesthesiologists (ASA recommend monitoring of pulse oximetry, blood pressure, heart rate, and end tidal CO2 during the use of anesthesia and sedation. This information can help to identify adverse events that may occur during procedures. However, these parameters are not specific to the effects of anesthetics or sedatives, and therefore they offer little, to no, real time information regarding the effects of those agents and do not give the clinician the lead-time necessary to prevent patient “awareness.” Since no “gold-standard” method is available to continuously, reliably, and effectively monitor the effects of sedatives and anesthetics, such a method is greatly needed. Investigation of the use of functional near-infrared spectroscopy (fNIRS as a method for anesthesia or sedation monitoring and for the assessment of the effects of various anesthetic drugs on cerebral oxygenation has started to be conducted. The objective of this paper is to provide a thorough review of the currently available published scientific studies regarding the use of fNIRS in the fields of anesthesia and sedation monitoring, comment on their findings, and discuss the future work required for the translation of this technology to the clinical setting.

  18. Near-Infrared Grating Spectrometer for Mobile Phone Applications.

    Science.gov (United States)

    Pügner, Tino; Knobbe, Jens; Grüger, Heinrich

    2016-05-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications.

  19. Distributed Software for Observations in the Near Infrared

    Science.gov (United States)

    Gavryusev, V.; Baffa, C.; Giani, E.

    We have developed an integrated system that performs astronomical observations in Near Infrared bands operating two-dimensional instruments at the Italian National Infrared Facility's \\htmllink{ARNICA}{http://helios.arcetri.astro.it:/home/idefix/Mosaic/ instr/arnica/arnica.html} and \\htmllink{LONGSP}{http://helios.arcetri.astro.it:/home/idefix/Mosaic/ instr/longsp/longsp.html}. This software consists of several communicating processes, generally executed across a network, as well as on a single computer. The user interface is organized as widget-based X11 client. The interprocess communication is provided by sockets and uses TCP/IP. The processes denoted for control of hardware (telescope and other instruments) should be executed currently on a PC dedicated for this task under DESQview/X, while all other components (user interface, tools for the data analysis, etc.) can also work under UNIX\\@. The hardware independent part of software is based on the Athena Widget Set and is compiled by GNU C to provide maximum portability.

  20. Measurement of subcutaneous adipose tissue thickness by near-infrared.

    Science.gov (United States)

    Wang, Yu; Yang, Zeqiang; Hao, Dongmei; Zhang, Song; Yang, Yimin; Zeng, Yanjun

    2013-06-01

    Obesity is strongly associated with the risks of diabetes and cardiovascular disease, and there is a need to measure the subcutaneous adipose tissue (SAT) layer thickness and to understand the distribution of body fat. A device was designed to illuminate the body parts by near-infrared (NIR), measure the backscattered light, and predict the SAT layer thickness. The device was controlled by a single-chip microcontroller (SCM), and the thickness value was presented on a liquid crystal display (LCD). There were 30 subjects in this study, and the measurements were performed on 14 body parts for each subject. The paper investigated the impacts of pressure and skin colour on the measurement. Combining with principal component analysis (PCA) and support vector regression (SVR), the measurement accuracy of SAT layer thickness was 89.1 % with a mechanical caliper as reference. The measuring range was 5-11 mm. The study provides a non-invasive and low-cost technique to detect subcutaneous fat thickness, which is more accessible and affordable compared to other conventional techniques. The designed device can be used at home and in community.

  1. A 600 minute near-infrared lightcurve of Sagittarius A*

    CERN Document Server

    Meyer, L; Ghez, A; Morris, M R; Witzel, G; Eckart, A; Bélanger, G; Schödel, R

    2008-01-01

    We present the longest, by a factor of two, near-infrared lightcurve from Sgr A* - the supermassive black hole in the Galactic center. Achieved by combining Keck and VLT data from one common night, which fortuitously had simultaneous Chandra and SMA data, this lightcurve is used to address two outstanding problems. First, a putative quasi-periodicity of ~20 min reported by groups using ESO's VLT is not confirmed by Keck observations. Second, while the infrared and mm-regimes are thought to be related based on reported time lags between lightcurves from the two wavelength domains, the reported time lag of 20 min inferred using the Keck data of this common VLT/Keck night only is at odds with the lag of ~100 min reported earlier. With our long lightcurve, we find that (i) the simultaneous 1.3 millimeter observations are in fact consistent with a ~100 min time lag, (ii) the different methods of NIR photometry used by the VLT and Keck groups lead to consistent results, (iii) the Lomb-Scargle periodogram of the who...

  2. Near-infrared free carrier absorption in heavily doped silicon

    Energy Technology Data Exchange (ETDEWEB)

    Baker-Finch, Simeon C., E-mail: simeon.bakerfinch@gmail.com [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia); PV Lighthouse, Coledale, NSW 2515 (Australia); McIntosh, Keith R. [PV Lighthouse, Coledale, NSW 2515 (Australia); Yan, Di; Fong, Kean Chern; Kho, Teng C. [School of Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2014-08-14

    Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500 nm, and the range of dopant densities between ∼10{sup 18} and 3 × 10{sup 20} cm{sup −3}. Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis.

  3. Near-Infrared Photobiomodulation in Retinal Injury and Disease.

    Science.gov (United States)

    Eells, Janis T; Gopalakrishnan, Sandeep; Valter, Krisztina

    2016-01-01

    Evidence is growing that exposure of tissue to low energy photon irradiation in the far-red (FR) to near-infrared (NIR) range of the spectrum, collectively termed "photobiomodulation" (PBM) can restore the function of damaged mitochondria, upregulate the production of cytoprotective factors and prevent apoptotic cell death. PBM has been applied clinically in the treatment of soft tissue injuries and acceleration of wound healing for more than 40 years. Recent studies have demonstrated that FR/NIR photons penetrate diseased tissues including the retina. The therapeutic effects of PBM have been hypothesized to result from intracellular signaling pathways triggered when FR/NIR photons are absorbed by the mitochondrial photoacceptor molecule, cytochrome c oxidase, culminating in improved mitochondrial energy metabolism, increased cytoprotective factor production and cell survival. Investigations in rodent models of methanol-induced ocular toxicity, light damage, retinitis pigmentosa and age-related macular degeneration have demonstrated the PBM attenuates photoreceptor cell death, protects retinal function and exerts anti-inflammatory actions.

  4. DIAGNOcam--a Near Infrared Digital Imaging Transillumination (NIDIT) technology.

    Science.gov (United States)

    Abdelaziz, Marwa; Krejci, Ivo

    2015-01-01

    In developed countries, clinical manifestation of carious lesions is changing: instead of dentists being confronted with wide-open cavities, more and more hidden caries are seen. For a long time, the focus of the research community was on finding a method for the detection of carious lesions without the need for radiographs. The research on Digital Imaging Fiber-Optic Transillumination (DIFOTI) has been an active domain. The scope of the present article is to describe a novel technology for caries diagnostics based on Near Infrared Digital Imaging Transillumination (NIDIT), and to give first examples of its clinical indications. In addition, the coupling of NIDIT with a head-mounted retinal image display (RID) to improve clinical workflow is presented. The novel NIDIT technology was shown to be useful as a diagnostic tool in several indications, including mainly the detection of proximal caries and, less importantly, for occlusal caries, fissures, and secondary decay around amalgam and composite restorations. The coupling of this technology with a head-mounted retinal image system allows for its very efficient implementation into daily practice.

  5. Near infrared observations of the truncation of stellar disks

    CERN Document Server

    Florido, E; Guijarro, A; Garzón, F; Jiménez-Vicente, J; Florido, Estrella; Battaner, Eduardo; Guijarro, Ana; Garzon, Francisco; Jimenez-Vicente, Jorge

    2001-01-01

    We present a first study of truncation of the stellar disks of spiral galaxies in the near infrared. Observations of NGC4013, NGC4217, NGC6504 and NGC5981 were made with the CAIN NIR camera on the CST in Tenerife. This wavelength range provides the best description of the phenomenon, not only because extinction effects are minimized, but also because the distribution of the old stellar population is directly obtained. The four galaxies are edge-on and an inversion method was developed to obtain the deprojected profiles. We did not assume any model of the different galactic components. The ``truncation curve'', i.e. T(R)= mu(R)- mu_{D}(R), where mu is the actual surface brightness in mag/arcsec^2 and mu_{D} the exponential disk surface brightness, has been obtained with unprecedented precision. It is suggested that T(R) is proportional to (R_{t}-R)^{-1}, where R_{t} is the truncation radius, i.e. the radius beyond which no star is observed.

  6. Near-infrared spectroscopy of EX Lupi in outburst

    CERN Document Server

    Kóspál, Á; Goto, M; Regály, Zs; Dullemond, C P; Henning, Th; Juhász, A; Sicilia-Aguilar, A; Ancker, M van den

    2011-01-01

    EX Lup is the prototype of the EXor class of young eruptive stars: objects showing repetitive brightenings due to increased accretion from the circumstellar disk to the star. In this paper, we report on medium-resolution near-infrared spectroscopy of EX\\,Lup taken during its extreme outburst in 2008, as well as numerical modeling with the aim of determining the physical conditions around the star. We detect emission lines from atomic hydrogen, helium, and metals, as well as first overtone bandhead emission from carbon monoxide. Our results indicate that the emission lines are originating from gas located in a dust-free region within ~ 0.2 AU of the star. The profile of the CO bandhead indicates that the CO gas has a temperature of 2500 K, and is located in the inner edge of the disk or in the outer parts of funnel flows. The atomic metals are probably co-located with the CO. Some metallic lines are fluorescently excited, suggesting direct exposure to ultraviolet photons. The Brackett series indicates emission...

  7. Prediction of chicken quality attributes by near infrared spectroscopy.

    Science.gov (United States)

    Barbin, Douglas Fernandes; Kaminishikawahara, Cintia Midori; Soares, Adriana Lourenco; Mizubuti, Ivone Yurika; Grespan, Moises; Shimokomaki, Massami; Hirooka, Elisa Yoko

    2015-02-01

    In the present study, near-infrared (NIR) reflectance was tested as a potential technique to predict quality attributes of chicken breast (Pectoralis major). Spectra in the wavelengths between 400 and 2500nm were analysed using principal component analysis (PCA) and quality attributes were predicted using partial least-squares regression (PLSR). PCA performed on NIR dataset revealed the influence of muscle reflectance (L(∗)) influencing the spectra. PCA was not successful to completely discriminate between pale, soft and exudative (PSE) and pale-only muscles. High-quality PLSR were obtained for L(∗) and pH models predicted individually (R(2)CV of 0.91 and 0.81, and SECV of 1.99 and 0.07, respectively). Water-holding capacity was the most challenging attribute to determine (R(2)CV of 0.70 and SECV of 2.40%). Sample mincing and different spectra pre-treatments were not necessary to maximise the predictive performance of models. Results suggest that NIR spectroscopy can become useful tool for quality assessment of chicken meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Red/near-infrared reflectance sensor system for detecting plants

    Science.gov (United States)

    Von Bargen, Kenneth; Meyer, George E.; Mortensen, David A.; Merritt, Steven J.; Woebbecke, David M.

    1993-05-01

    Growing plants, soil types, and surfaces and residues on a soil surface have distinct natural light reflectances. These reflectance characteristics have been determined using current spectroradiometry technology. Detection of plants is possible based upon the distinct reflectance characteristics of plants, soil, and residues. An optical plant reflectance sensor was developed which utilizes a pair of red and near infrared sensitive photodetectors to measure the radiancy from the plant and soil. Another pair of sensors measures radiancy from a highly radiant reference surface to accommodate varying intensities of the natural light. The ratio of the target and reference radiancies is the target reflectance. Optical filters were used to select the spectral bandwidth sensitivities for the red and NIR photodetectors. The reflectance values were digitized for incorporation into a normalized difference index in order to provide a stronger indication that a live plant is present within the field of view of the sensor. This sensor system was combined with a microcontroller for activating a solenoid controlled spray nozzle on a single unit prototype spot agricultural sprayer.

  9. Assessment of hyaline cartilage matrix composition using near infrared spectroscopy.

    Science.gov (United States)

    Palukuru, Uday P; McGoverin, Cushla M; Pleshko, Nancy

    2014-09-01

    Changes in the composition of the extracellular matrix (ECM) are characteristic of injury or disease in cartilage tissue. Various imaging modalities and biochemical techniques have been used to assess the changes in cartilage tissue but lack adequate sensitivity, or in the case of biochemical techniques, result in destruction of the sample. Fourier transform near infrared (FT-NIR) spectroscopy has shown promise for the study of cartilage composition. In the current study NIR spectroscopy was used to identify the contributions of individual components of cartilage in the NIR spectra by assessment of the major cartilage components, collagen and chondroitin sulfate, in pure component mixtures. The NIR spectra were obtained using homogenous pellets made by dilution with potassium bromide. A partial least squares (PLS) model was calculated to predict composition in bovine cartilage samples. Characteristic absorbance peaks between 4000 and 5000 cm(-1) could be attributed to components of cartilage, i.e. collagen and chondroitin sulfate. Prediction of the amount of collagen and chondroitin sulfate in tissues was possible within 8% (w/dw) of values obtained by gold standard biochemical assessment. These results support the use of NIR spectroscopy for in vitro and in vivo applications to assess matrix composition of cartilage tissues, especially when tissue destruction should be avoided. Copyright © 2014. Published by Elsevier B.V.

  10. Near infrared spectroscopic evaluation of water in hyaline cartilage.

    Science.gov (United States)

    Padalkar, M V; Spencer, R G; Pleshko, N

    2013-11-01

    In diseased conditions of cartilage such as osteoarthritis, there is typically an increase in water content from the average normal of 60-85% to greater than 90%. As cartilage has very little capability for self-repair, methods of early detection of degeneration are required, and assessment of water could prove to be a useful diagnostic method. Current assessment methods are either destructive, time consuming, or have limited sensitivity. Here, we investigated the hypotheses that non-destructive near infrared spectroscopy (NIRS) of articular cartilage can be used to differentiate between free and bound water, and to quantitatively assess water content. The absorbances centered at 5200 and 6890 cm(-1) were attributed to a combination of free and bound water, and to free water only, respectively. The integrated areas of both absorbance bands were found to correlate linearly with the absolute water content (R = 0.87 and 0.86) and with percent water content (R = 0.97 and 0.96) of the tissue. Partial least square models were also successfully developed and were used to predict water content, and percent free water. These data demonstrate that NIRS can be utilized to quantitatively determine water content in articular cartilage, and may aid in early detection of degenerative tissue changes in a laboratory setting, and with additional validations, possibly in a clinical setting.

  11. SYNTHESIS AND CHARACTERIZATIONS OF NEAR INFRARED ABSORBING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    Ying-hua Qi; Pierre Desjardins; Maria Birau; Xian-guo Wu; Zhi-yuan Wang

    2003-01-01

    A series of near infrared (NIR) absorbing dinuclear ruthenium dicarbonylhydrazine complexes (DCH-Ru),[{Ru(bpy)2}2μ-DCH]n+ (where bpy = 2,2'-bipyridine and n = 2, 3 or 4), were prepared. The DCH-Ru complexes are electrochromic in the NIR region with a high absorption coefficient at 1550-1600 nm typically over 10000 M-1cm-1. DCHRu complex polymers with good NIR electrochromic properties were also obtained and processed to make a device for optical attenuation at a wavelength of 1550 nm. The potential of these DCH-Ru polymers for use in a variable optical attenuator has been demonstrated with an attenuating power at the 1550-nm telecommunication wavelength over 7.0 dB per micron of polymer film thickness. Other classes of NIR active materials are the pentacenediquinones and the corresponding poly(ether pentacenediquinone)s. These polymers can be electrochemically reduced to the corresponding semiquinone (radical anion) having NIR absorption within a telecom window (e.g., 1310 nm).

  12. SYNTHESIS AND CHARACTERIZATIONS OF NEAR INFRARED ABSORBING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    Ying-huaQi; PierreDesjardins; MariaBirau; Xian-guoWu; Zhi-yuanWang; Zhi-yuanWang

    2003-01-01

    A series of near infrared (NIR) absorbing dinuclear ruthenium dicarbonylhydrazine complexes(DCH-Ru),[{Ru(bpy)2}2μ-DCH]n+ (where bpy=2,2'=-bipyridine and n=2,3 or 4),were prepared.The DCH-Ru complexes are electrochromic in the NIR region with a high absorption coefficient at 1550-1600nm typically over 10000M-1cm-1.DCH-Ru complex polymers with good NIR electrochromic properties were also obtained and processed to make a device for optical attenuation at a wavelength of 1550nm.The potential of these DCH-Ru polymers for use in a variable optical attenuator has been demonstrated with an attenuating power at the 1550-nm telecommunication wavelength over 7.0dB per micron of polymer film thickness.Other classes of NIR active materials are the pentacenediquinones and the corresponding poly(ether pentacenediquinone)s.These polymers can be electrochemically reduced to the corresponding semiquinone (radical anion) having NIR absorption within a telecom window(e.g.,1310nm).

  13. Near-infrared spectropolarimetry of a delta-spot

    CERN Document Server

    Balthasar, H; Louis, R E; Verma, M; Denker, C

    2014-01-01

    Sunspots harboring umbrae of both magnetic polarities within a common penumbra (delta-spots) are often but not always related to flares. We present first near-infrared (NIR) observations (Fe I 1078.3 nm and Si I 1078.6 nm spectra) obtained with the Tenerife Infrared Polarimeter (TIP) at the Vacuum Tower Telescope (VTT) in Tenerife on 2012 June 17, which afford accurate and sensitive diagnostics to scrutinize the complex fields along the magnetic neutral line of a delta-spot within active region NOAA 11504. We examine the vector magnetic field, line-of-sight (LOS) velocities, and horizontal proper motions of this rather inactive delta-spot. We find a smooth transition of the magnetic vector field from the main umbra to that of opposite polarity (delta-umbra), but a discontinuity of the horizontal magnetic field at some distance from the delta-umbra on the polarity inversion line. The magnetic field decreases faster with height by a factor of two above the delta-umbra. The latter is surrounded by its own Eversh...

  14. Near-infrared spectroscopy for burning plasma diagnostic applications.

    Science.gov (United States)

    Soukhanovskii, V A

    2008-10-01

    Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ionized fuel species (H, D, T, and Li) and impurities (e.g., He, Be, C, and W) is a key element of plasma control and diagnosis on International Thermonuclear Experimental Reactor and future magnetically confined burning plasma experiments (BPXs). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window, and optical fiber transmission under intense neutron and gamma-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can be used for machine protection and plasma control applications, as well as contribute to plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to the parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma-facing component temperatures.

  15. Non-linear calibration models for near infrared spectroscopy.

    Science.gov (United States)

    Ni, Wangdong; Nørgaard, Lars; Mørup, Morten

    2014-02-27

    Different calibration techniques are available for spectroscopic applications that show nonlinear behavior. This comprehensive comparative study presents a comparison of different nonlinear calibration techniques: kernel PLS (KPLS), support vector machines (SVM), least-squares SVM (LS-SVM), relevance vector machines (RVM), Gaussian process regression (GPR), artificial neural network (ANN), and Bayesian ANN (BANN). In this comparison, partial least squares (PLS) regression is used as a linear benchmark, while the relationship of the methods is considered in terms of traditional calibration by ridge regression (RR). The performance of the different methods is demonstrated by their practical applications using three real-life near infrared (NIR) data sets. Different aspects of the various approaches including computational time, model interpretability, potential over-fitting using the non-linear models on linear problems, robustness to small or medium sample sets, and robustness to pre-processing, are discussed. The results suggest that GPR and BANN are powerful and promising methods for handling linear as well as nonlinear systems, even when the data sets are moderately small. The LS-SVM is also attractive due to its good predictive performance for both linear and nonlinear calibrations.

  16. The near-infrared spectrum of ethynyl radical

    CERN Document Server

    Le, Anh T; Sears, Trevor J

    2016-01-01

    Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C$_2$H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a $^2\\Sigma ^+$ state at 6696 cm$^{-1}$, a second $^2\\Sigma ^+$ state at 7088 cm$^{-1}$, and a $^2\\Pi$ state at 7110 cm$^{-1}$. By comparison with published calculations (R. Tarroni and S. Carter, \\textit{J. Chem. Phys} \\textbf{119}, 12878 (2003) and \\textit{Mol. Phys}. \\textbf{102}, 2167 (2004)), the vibronic character of these levels was also assigned. The observed states...

  17. Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Gan Luo

    2015-01-01

    Full Text Available Chemical and physical quality attributes of herbal extract powders play an important role in the research and development of Chinese medicine preparations. The active pharmaceutical ingredients have a direct impact on the herbal extract’s efficacy, while the physical properties of raw material affect the pharmaceutical manufacturing process and the final products’ quality. In this study, tanshinone extract powders from Salvia miltiorrhiza which are widely used for the treatment of cardiovascular diseases in the clinic are taken as the research object. Both the chemical information and physical information of tanshinone extract powders are analyzed by near infrared (NIR spectroscopy. The partial least squares (PLS and least square support vector machine (LS-SVM models are investigated to build the relationship between NIR spectra and reference values. PLS models performed well for the content of crytotanshinone, tanshinone IIA, the moisture, and average median particle size, while, for specific surface area and tapped density, the LS-SVM models performed better than the PLS models. Results demonstrated NIR to be a valid and fast process analytical technology tool to simultaneously determine multiple quality attributes of herbal extract powders and indicated that there existed some nonlinear relationship between NIR spectra and physical quality attributes.

  18. The application of near infrared spectroscopy in nutritional intervention studies

    Directory of Open Access Journals (Sweden)

    Philippa A Jackson

    2013-08-01

    Full Text Available Functional near infrared spectroscopy (NIRS is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials—in which the effects on CBF following administration of dietary components such as caffeine, polyphenols and omega-3 polyunsaturated fatty acids are assessed—have successfully demonstrated NIRS as a sensitive measure of change in haemodynamic response during cognitive tasks in both acute and chronic treatment intervention paradigms. The existent research in this area has been limited by the constraints of the technique itself however advancements in the measurement technology, paired with studies endeavouring increased sophistication in number and locations of channels over the head should render the use of NIRS in nutritional interventions particularly valuable in advancing our understanding of the effects of nutrients and dietary components on the brain.

  19. Bundled-Optode Method in Functional Near-Infrared Spectroscopy

    Science.gov (United States)

    Nguyen, Hoang-Dung; Hong, Keum-Shik; Shin, Yong-Il

    2016-01-01

    In this paper, a theory for detection of the absolute concentrations of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) from hemodynamic responses using a bundled-optode configuration in functional near-infrared spectroscopy (fNIRS) is proposed. The proposed method is then applied to the identification of two fingers (i.e., little and thumb) during their flexion and extension. This experiment involves a continuous-wave-type dual-wavelength (760 and 830 nm) fNIRS and five healthy male subjects. The active brain locations of two finger movements are identified based on the analysis of the t- and p-values of the averaged HbOs, which are quite distinctive. Our experimental results, furthermore, revealed that the hemodynamic responses of two-finger movements are different: The mean, peak, and time-to-peak of little finger movements are higher than those of thumb movements. It is noteworthy that the developed method can be extended to 3-dimensional fNIRS imaging. PMID:27788178

  20. High-Performance Near-Infrared Luminescent Solar Concentrators.

    Science.gov (United States)

    Rondão, Raquel; Frias, Ana R; Correia, Sandra F H; Fu, Lianshe; de Zea Bermudez, Verónica; André, Paulo S; Ferreira, Rute A S; Carlos, Luís D

    2017-04-12

    Luminescent solar concentrators (LSCs) appear as candidates to enhance the performance of photovoltaic (PV) cells and contribute to reduce the size of PV systems, decreasing, therefore, the amount of material needed and thus the cost associated with energy conversion. One way to maximize the device performance is to explore near-infrared (NIR)-emitting centers, resonant with the maximum optical response of the most common Si-based PV cells. Nevertheless, very few examples in the literature demonstrate the feasibility of fabricating LSCs emitting in the NIR region. In this work, NIR-emitting LSCs are reported using silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) (SiNc or NIR775) immobilized in an organic-inorganic tri-ureasil matrix (t-U(5000)). The photophysical properties of the SiNc dye incorporated into the tri-ureasil host closely resembled those of SiNc in tetrahydrofuran solution (an absolute emission quantum yield of ∼0.17 and a fluorescence lifetime of ∼3.6 ns). The LSC coupled to a Si-based PV device revealed an optical conversion efficiency of ∼1.5%, which is among the largest values known in the literature for NIR-emitting LSCs. The LSCs were posteriorly coupled to a Si-based commercial PV cell, and the synergy between the t-U(5000) and SiNc molecules enabled an effective increase in the external quantum efficiency of PV cells, exceeding 20% in the SiNc absorption region.

  1. Standardization of near infrared spectra measured on multi-instrument.

    Science.gov (United States)

    Liu, Yan; Cai, Wensheng; Shao, Xueguang

    2014-07-11

    Calibration model transfer is essential for practical applications of near infrared (NIR) spectroscopy because the measurements of the spectra may be performed on different instruments and the difference between the instruments must be corrected. An approach for calibration transfer based on alternating trilinear decomposition (ATLD) algorithm is proposed in this work. From the three-way spectral matrix measured on different instruments, the relative intensity of concentration, spectrum and instrument is obtained using trilinear decomposition. Because the relative intensity of instrument is a reflection of the spectral difference between instruments, the spectra measured on different instruments can be standardized by a correction of the coefficients in the relative intensity. Two NIR datasets of corn and tobacco leaf samples measured with three instruments are used to test the performance of the method. The results show that, for both the datasets, the spectra measured on one instrument can be correctly predicted using the partial least squares (PLS) models built with the spectra measured on the other instruments.

  2. The application of near infrared spectroscopy (NIR technique for

    Directory of Open Access Journals (Sweden)

    Sandor Barabassy

    2001-06-01

    Full Text Available The production of cow’s milk in Hungary fluctuates by 15-20 % annualy. Surplus milk is dried into powder and can also be converted to modified milk powders using techniques such as ultra filtration. From approximetely 20.000 tonnes, of all milk powder types, 3.000 tonnes, is converted using ultra filtration technology. Multivariable near infrared (NIR calibration was performed on powder mixtures of whole milk, skimmed milk, whey, retenate (protein concentrate and lactose for rapid fat, protein, lactose, water and ash content determination. More than 150 samples were prepared and measured in two NIRS labs (Scottish Agriculture College – SAC – Aberdeen and University of Horticulture and Food Science - UHFS – Budapest. The results obtained from the same samples were compared. The aims of the study were: 1. Rapid quantitative and qualitative determination of mixtures of milk powder products using NIR technique. 2. Comparison of the results achieved in Aberdeen (SAC and Budapest (UHFS institutes. The mass per cent varied between 0.0-2.8% for fat, 0.0-80% for protein, 6.6-100 % for lactose, 0.0-5.0 % for water and 0.0-8.0 % for ash. High correlation coefficients (0.97-0.99 were found for all five components.

  3. Population III and the Near-Infrared Backround Excess

    CERN Document Server

    Silk, P M J

    2005-01-01

    We make a critical assessment of models that attribute the recently detected near-infrared background ``excess'' (NIRBE) to the redshifted light from Population III objects. To supply the required 25 keV/baryon at redshift 9, Pop III massive stars must form with an efficiency exceeding 30% in all ``minihalos'' with virial temperatures above a few hundred kelvins: to avoid excessive metal pollution, most of the baryons once in Pop III stars must end up in intermediate-mass black holes (IMBHs). Gas accretion onto such IMBHs must either be inhibited or lead to early miniquasars with steep UV/X-ray spectra, in order not to overproduce the present-day unresolved soft X-ray background. In the latter case (NIRBE dominated by "X-ray quiet miniquasars"), the total mass density of IMBHs at redshift 9 must be greater than 50 times higher than the mass density of supermassive black holes observed today in the nuclei of galaxies. A stellar-dominated NIRBE is less economical energetically: more than 5% of all baryons in th...

  4. Near-Infrared water lines in V838 Monocerotis

    CERN Document Server

    Banerjee, D P K; Ashok, N M; Tennyson, J

    2005-01-01

    V838 Monocerotis had an intriguing, nova-like outburst in January 2002 which has subsequently led to several studies of the object. It is now recognized that the outburst of V838 Mon and its evolution are different from that of a classical nova or other classes of well-known eruptive variables. V838 Mon, along with two other objects that have analogous properties, appears to comprise a new class of eruptive variables. There are limited infrared studies of V838 Mon. Here, we present near-infrared H band (1.5 - 1.75micron) spectra of V838 Mon from late 2002 to the end of 2004. The principal, new result from our work is the detection of several, rotation-vibration lines of water in the H band spectra. The observed water lines have been modeled to first establish that they are indeed due to water. Subsequently the temperature and column densities of the absorbing material, from where the water absorption features originate, are derived. From our analysis, we find that the water features arise from a cool ~750-900...

  5. Near-infrared light-responsive nanomaterials in cancer therapeutics.

    Science.gov (United States)

    Shanmugam, Vijayakumar; Selvakumar, S; Yeh, Chen-Sheng

    2014-09-07

    Noninvasive techniques, such as breath tests (urea breath test), blood pressure measurements using a sphygmomanometer and electrocardiography, were employed by a physician to perform classical diagnosis. The use of state-of-the-art noninvasive therapies at the organ level in modern medicine has gradually become possible. However, cancer treatment demands spatially and temporally controlled noninvasive therapy at the cell level because nonspecific toxicity often causes complicated side effects. To increase survival in cancer patients further, combination therapy and combination drugs are explored which demand high specificity to avoid combined-drug side effects. We believe that high specificity could be obtained by implementing near-infrared (NIR) light-assisted nanoparticles in photothermal therapy, chemotherapy, and photodynamic therapy. To refine this therapy and subsequently achieve high efficiency, novel nanomaterials have been designed and modified either to enhance the uptake and drug delivery to the cancer site, or control treatment to administer therapy efficiently. These modifications and developments have been demonstrated to achieve spatial and temporal control when conducting an in vivo xenograft, because the NIR light penetrated effectively the biological tissue. The nanoplatforms discussed in this review are grouped under the following subheadings: Au nanorods (NRs), Au nanoshells, other Au-related nanomaterials, graphene oxide, upconversion nanoparticles, and other related materials (including materials such as CuS, Fe3O4-related systems, and carbon nanotubes (CNTs)).

  6. Functional nanomaterials for near-infrared-triggered cancer therapy.

    Science.gov (United States)

    Liu, Bei; Li, Chunxia; Cheng, Ziyong; Hou, Zhiyao; Huang, Shanshan; Lin, Jun

    2016-06-24

    The near-infrared (NIR) region (700-1100 nm) is the so-called transparency "therapeutic window" for biological applications owing to its deeper tissue penetration and minimal damage to healthy tissues. In recent years, various NIR-based therapeutic and interventional strategies, such as NIR-triggered drug delivery, photothermal therapy (PTT) and photodynamic therapy (PDT), are under research in intensive preclinical and clinical investigations for cancer treatment. The NIR control in these cancer therapy systems is considered crucial to boost local effective tumor suppression while minimizing side effects, resulting in improved therapeutic efficacy. Some researchers even predict the NIR-triggered cancer therapy to be a new and exciting possibility for clinical nanomedicine applications. In this review, the rapid development of NIR light-responsive cancer therapy based on various smartly designed nanocomposites for deep tumor treatments is introduced. In detail, the use of NIR-sensitive materials for chemotherapy, PTT as well as PDT is highlighted, and the associated challenges and potential solutions are discussed. The applications of NIR-sensitive cancer therapy modalities summarized here can highlight their potential use as promising nanoagents for deep tumor therapy.

  7. Prediction of sheep responses by near infrared reflectance spectroscopy.

    Science.gov (United States)

    Eckman, D D; Shenk, J S; Wangsness, P J; Westerhaus, M O

    1983-09-01

    Prediction of animal response from near infrared reflectance spectra of feeds was compared with predictions from chemical analyses. Sixty samples of pure and mixed forage-based diets were obtained from sheep intake and digestion trials. Sheep responses measured were digestible energy, dry matter intake, and calculated intake of digestible energy. Diets were analyzed chemically for protein, neutral detergent fiber, and in vitro dry matter disappearance. Coefficients of multiple determination and standard errors for fitting the sheep responses to these 60 diverse diets by regression equations developed from chemical analyses (.62 to .70) or spectra (.63 to .72) were similar. The 60 diets were divided into two sets of 30; one set was used to develop calibration equations for each sheep response, and the second set was used to test the equations. Calibration and errors of prediction were similar. When wavelengths chosen for each of the laboratory measurements were used to fit the sheep responses, standard errors were higher than when responses of sheep were predicted directly from spectra. The scanning instrument has the capability of predicting laboratory analyses and shows potential for predicting animal response as accurately as animal response can be predicted from laboratory analyses.

  8. Near infrared spectroscopy in the study of polymorphic transformations

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Marcel [Department of Chemistry, Analytical Chemistry Unity, Faculty of Sciences, Autonomous University of Barcelona, E-08193 Bellaterra, Barcelona (Spain)]. E-mail: marcel.blanco@uab.es; Alcala, Manel [Department of Chemistry, Analytical Chemistry Unity, Faculty of Sciences, Autonomous University of Barcelona, E-08193 Bellaterra, Barcelona (Spain); Gonzalez, Josep M. [Laboratorios Menarini S.A., c/. Alfons XII, 587, E-08918 Badalona, Barcelona (Spain); Torras, Ester [Laboratorios Menarini S.A., c/. Alfons XII, 587, E-08918 Badalona, Barcelona (Spain)

    2006-05-17

    The potential of near infrared (NIR) spectroscopy for the characterization of polymorphs in the active principle of a commercial formulation prior to and after the manufacturing process was assessed. Polymorphism in active principles is extremely significant to the pharmaceutical industry. Polymorphic changes during the production of commercial pharmaceutical formulations can alter some properties of the resulting end-products. Multivariate curve resolution-alternating least squares (MCR-ALS) methodology was used to obtain the 'pure' NIR spectrum for the active principle without the need to pretreat samples. This methodology exposed the polymorphic transformation of Dexketoprofen Trometamol (DKP) in both laboratory and production samples obtained by wet granulation. No polymorphic transformation, however, was observed in samples obtained by direct compaction. These results were confirmed using by X-ray powder diffractometry (XRD) and differential scanning calorimetry (DSC) measurements. Pure crystalline polymorphs of DKP were available in the laboratory but amorphous form was not, nevertheless the developed methodology allows the identification of amorphous and crystal forms in spite of the lack of pure DKP.

  9. Retinal safety of near-infrared lasers in cataract surgery

    Science.gov (United States)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel

    2012-09-01

    Femtosecond lasers have added unprecedented precision and reproducibility to cataract surgery. However, retinal safety limits for the near-infrared lasers employed in surgery are not well quantified. We determined retinal injury thresholds for scanning patterns while considering the effects of reduced blood perfusion from rising intraocular pressure and retinal protection from light scattering on bubbles and tissue fragments produced by laser cutting. We measured retinal damage thresholds of a stationary, 1030-nm, continuous-wave laser with 2.6-mm retinal spot size for 10- and 100-s exposures in rabbits to be 1.35 W (1.26 to 1.42) and 0.78 W (0.73 to 0.83), respectively, and 1.08 W (0.96 to 1.11) and 0.36 W (0.33 to 0.41) when retinal perfusion is blocked. These thresholds were input into a computational model of ocular heating to calculate damage threshold temperatures. By requiring the tissue temperature to remain below the damage threshold temperatures determined in stationary beam experiments, one can calculate conservative damage thresholds for cataract surgery patterns. Light scattering on microbubbles and tissue fragments decreased the transmitted power by 88% within a 12 deg angle, adding a significant margin for retinal safety. These results can be used for assessment of the maximum permissible exposure during laser cataract surgery under various assumptions of blood perfusion, treatment duration, and scanning patterns.

  10. Near-infrared (NIR) up-conversion optogenetics

    Science.gov (United States)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-11-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650-1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called ‘imaging window’. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system.

  11. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    Science.gov (United States)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  12. Observations of the Near-Infrared Spectrum of the Zodiacal Light with CIBER

    CERN Document Server

    Tsumura, K; Bock, J; Cooray, A; Hristov, V; Keating, B; Lee, D H; Levenson, L R; Mason, P; Matsumoto, T; Matsuura, S; Nam, U W; Renbarger, T; Sullivan, I; Suzuki, K; Wada, T; Zemcov, M

    2010-01-01

    Interplanetary dust (IPD) scatters solar radiation which results in the zodiacal light that dominates the celestial diffuse brightness at optical and near-infrared wavelengths. Both asteroid collisions and cometary ejections produce the IPD, but the relative contribution from these two sources is still unknown. The Low Resolution Spectrometer (LRS) onboard the Cosmic Infrared Background Experiment (CIBER) observed the astrophysical sky spectrum between 750 and 2100 nm over a wide range of ecliptic latitude. The resulting zodiacal light spectrum is redder than the solar spectrum, and shows a broad absorption feature, previously unreported, at approximately 900 nm, suggesting the existence of silicates in the IPD material. The spectral shape of the zodiacal light is isotropic at all ecliptic latitudes within the measurement error. The zodiacal light spectrum, including the extended wavelength range to 2500 nm using IRTS data, is qualitatively similar to the reflectance of S-type asteroids. This result can be ex...

  13. Rapid near infrared spectroscopy for prediction of enzymatic hydrolysis of corn bran after various pretreatments

    DEFF Research Database (Denmark)

    Baum, Andreas; Agger, Jane; Meyer, Anne S.

    2012-01-01

    step is to increase the responsivity of the substrate to enzymatic attack and the type of pretreatment affects the enzymatic conversion efficiency. Destarched corn bran is a fibrous, heteroxylan-rich side-stream from the starch industry which may be used as a feedstock for bioethanol production...... or as a source of xylose for other purposes. In the present study we demonstrate the use of diffuse reflectance near infrared spectroscopy (NIR) as a rapid and non-destructive analytical tool for evaluation of pretreatment effects on destarched corn bran. NIR was used to achieve classification between 43...... differently pretreated corn bran samples using principal component analysis (PCA) and hierarchal clustering algorithms. Quantification of the enzymatically released monosaccharides by HPLC was used to design multivariate calibration models (biPLS) on the NIR spectra. The models could predict the enzymatic...

  14. Single-photon emission in the near infrared from diamond colour centre

    Energy Technology Data Exchange (ETDEWEB)

    Wu, E [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, ENS de Cachan, 61 avenue du President Wilson, 94235 Cachan Cedex (France); Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, 3663 Zhongshan Road North, Shanghai 200062 (China); Jacques, V. [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, ENS de Cachan, 61 avenue du President Wilson, 94235 Cachan Cedex (France); Treussart, F. [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, ENS de Cachan, 61 avenue du President Wilson, 94235 Cachan Cedex (France)]. E-mail: francois.treussart@physique.ens-cachan.fr; Zeng, H. [Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, 3663 Zhongshan Road North, Shanghai 200062 (China); Grangier, P. [Laboratoire Charles Fabry de l' Institut d' Optique, UMR CNRS 8501, BP 147, 91403 Orsay Cedex (France); Roch, J.-F. [Laboratoire de Photonique Quantique et Moleculaire, UMR CNRS 8537, ENS de Cachan, 61 avenue du President Wilson, 94235 Cachan Cedex (France)

    2006-07-15

    Optically active colour centres based on nickel-nitrogen impurities are observed in natural diamond under continuous-wave excitation. The spectral analysis shows that the single emitters have a narrow band emission in the near infrared, around 780 nm, which is almost entirely concentrated in the zero phonon line even at room temperature. The colour centre excited-state lifetime is as short as 2 ns, and the photoluminescence light is linear polarized. These striking features pave the way to the realization of a triggered single-photon source based on this colour centre emission well suited for open-air single-photon Quantum Key Distribution operating in day-light conditions.

  15. Full-angle optical imaging of near-infrared fluorescent probes implanted in small animals

    Institute of Scientific and Technical Information of China (English)

    Gang Hu; Junjie Yao; Jing Bai

    2008-01-01

    To provide a valuable experimental platform for in vivo biomedical research of small animal model with fluorescence mediated approach, we developed a whole-body near-infrared fluorescence molecular imaging system as described in this paper. This system is based on a sensitive CCD camera and has the ability to achieve 360° full-angle source illuminations and projections capture of the targets to obtain the dense sampling by performing rotational scan. The measurement accuracy is validated from cylinder phantom experiments by the comparison between the experimental data and theoretical predictions. Finally, we also present typical in vivo images of fluorescent tube implanted into the mouse body. The results are promising and have proved the system imaging performance for macroscopic optical biomedical research.

  16. Southern near-infrared photometric monitoring of Galactic young star clusters (NIP of Stars)

    CERN Document Server

    Barbá, R; Gunthardt, G; Robledo, S Torres; Jaque, M; Soto, M; Ferrero, G; Arias, J; Román-Lópes, A; Gamen, R; Hormazabal, J Astudillo

    2012-01-01

    We have performed a near-infrared photometric monitoring of 39 galactic young star clusters and star-forming regions, known as {\\em NIP of Stars}, between the years 2009--2011, using the Swope telescope at Las Campanas Observatory (Chile) and the RetroCam camera. The primary objective of the campaign is to perform a census of photometric variability of such clusters and to discover massive eclipsing binary stars. In this work, we describe the general idea, the implementation of the survey, and the first preliminary results of some of the observed clusters. This monitoring program is complementary to the Vista Variables in the V\\'ia L\\'actea (VVV), as the brightest sources observed in NIP of Stars are saturated in VVV.

  17. Broadband Near-Infrared Emission from Transparent Ni2+-Doped Sodium Aluminosilicate Glass Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Feng; FENG Gao-Feng; XU Shi-Qing; WU Bo-Tao; QIU Jian-Rong

    2006-01-01

    @@ Broadband near-infrared emission from transparent Ni2+-doped sodium aluminosilicate glass-ceramics is observed.The broad emission is centred at 1290nm and covers the whole telecommunication wavelength region (1100-1700nm) with full width at half maximum of about 340nm. The observed infrared emission could be attributed to the 3T2(F) → 3A2(F) transition of octahedral Ni2+ ions that occupy high-field sites in nanocrystals. The product of the lifetime and the stimulated emission cross section is 2.15 × 10-24 cm2s. It is suggested that Ni2+-doped sodium aluminosilicate glass ceramics have potential applications in tunable broadband light sources and broadband amplifiers.

  18. AKARI near-infrared background fluctuations arise from normal galaxy populations

    CERN Document Server

    Helgason, Kári

    2016-01-01

    We show that measurements of the fluctuations in the near-infrared background (NIRB) from the AKARI satellite can be explained by faint galaxy populations at low redshifts. We demonstrate this using reconstructed images from deep galaxy catalogs (HUGS/S-CANDELS) and two independent galaxy population models. In all cases, we find that the NIRB fluctuations measured by AKARI are consistent with faint galaxies and there is no need for a contribution from unknown populations. We find no evidence for a steep Rayleigh-Jeans spectrum for the underlying sources as previously reported. The apparent Rayleigh-Jeans spectrum at large angular scales is likely a consequence of galaxies being removed systematically to deeper levels in the longer wavelength channels.

  19. Southern near-infrared photometric monitoring of Galactic young star clusters (NIP of Stars)

    Science.gov (United States)

    Barbá, R.; Morrell, N. I.; Gunthardt, G.; Torres Robledo, S.; Jaque, M.; Soto, M.; Ferrero, G.; Arias, J. I.; Roman-Lopes, A.; Gamen, R. C.; Astudillo Hormazabal, J.

    We have performed a near-infrared photometric monitoring of 39 galactic young star clusters and star-forming regions, known as NIP of Stars, be- tween the years 2009-2011, using the Swope telescope at Las Campanas Observatory (Chile) and the RetroCam camera. The primary objective of the campaign is to perform a census of photometric variability of such clus- ters and to discover massive eclipsing binary stars. In this work, we describe the general idea, the implementation of the survey, and the first preliminary results of some of the observed clusters. This monitoring program is com- plementary to the Vista Variables in the Vía Láctea (VVV), as the brightest sources observed in NIP of Stars are saturated in VVV.

  20. Synthesis of near-infrared-emitting CdTe/CdSe/ZnSe/ZnS heterostructure.

    Science.gov (United States)

    Yang, Ping

    2014-04-01

    Near-infrared-emitting quantum dots (QDs) were fabricated via organic synthesis strategies through constructing CdTe/CdSe/ZnSe/ZnS multishell heterostructure. An effective shell-coating route was developed for multishell growth on CdTe cores. Core/shell growth was monitored by absorption and photoluminescence (PL) spectroscopy and transmission electron microscopy observation. Yellow emitting CdTe cores were coated with a CdSe shell to generate type II structure. This yields core/shell QDs with red photoluminescence. The passivation by the ZnSe shell having a substantially wide bandgap confines the excitons within the CdTe/CdSe interface and isolates them from the solution environment and consequently improves the stability of the heterostructure. An additional ZnS shell was deposited around the outer layer of CdTe/CdSe/ZnSe QDs to form a heterostructure through the reaction between zinc oleate and trioctylphosphine sulfur in the crude CdTe/CdSe/ZnSe solution. By varying CdTe core size and each shell thickness, the PL wavelength of the obtained heterostructure can span from 580 to 770 nm. The PL efficiency is quenched in CdTe QDs in diluted solution but increases substantially up to 24% for CdTe/CdSe core/shell QDs. The PL efficiency of CdTe/CdSe/ZnSe/ZnS QDs with average diameter of 5.4 nm and a PL peak wavelength of 770 nm is 20%.

  1. Monitoring Cerebral perfusion using near infrared spectroscopy and laser doppler flowmetry

    NARCIS (Netherlands)

    Klaessens, J.H.G.M.; Kolkman, R.G.M.; Hopman, J.C.W.; Hondebrink, E.; Liem, K.D.; Steenbergen, W.; Mul, de F.F.M.; Thijssen, J.M.

    2003-01-01

    This paper describes the simultaneous use of two, noninvasive, near-infrared techniques near-infrared spectroscopy (NIRS) and a continuous wave NIR laser Doppler flow system (LDF) to measure changes in the blood oxygenation, blood concentration and blood flow velocity in the brain. A piglet was used

  2. Monitoring cerebral perfusion using near-infrared spectroscopy and laser Doppler flowmetry.

    NARCIS (Netherlands)

    Klaessens, J.H.G.M.; Kolkman, R.G.; Hopman, J.C.W.; Hondebrink, E.; Liem, K.D.; Steenbergen, W.; Mul, F.F. de; Thijssen, J.M.

    2003-01-01

    This paper describes the simultaneous use of two, noninvasive, near-infrared techniques near-infrared spectroscopy (NIRS) and a continuous wave NIR laser Doppler flow system (LDF) to measure changes in the blood oxygenation, blood concentration and blood flow velocity in the brain. A piglet was used

  3. Discriminating oat and groat kernels from other grains using near infrared spectroscopy

    Science.gov (United States)

    Oat and groats can be discriminated from other grains such as barley, wheat, rye, and triticale (non-oats) using near infrared spectroscopy. The two instruments tested were the manual version of the ARS-USDA Single Kernel Near Infrared (SKNIR) and the automated QualySense QSorter Explorer high-speed...

  4. Near-Infrared Versus Mid-Infrared for the Quantitative and Qualitative Analysis of Soils

    Science.gov (United States)

    Over several decades, near-infrared reflectance spectroscopy has been shown to be extremely versatile for the rapid analysis of many agricultural materials including forages, foods and grains. More recently, mid-infrared and near-infrared diffuse reflectance spectroscopy (DRIFTS and NIRS, respective...

  5. Vibrational Spectroscopy of Intramolecular Hydrogen Bonds in the Infrared and Near-Infrared Regions

    DEFF Research Database (Denmark)

    Schrøder, Sidsel Dahl

    and 1,4-diaminobutane). Experimentally, the hydrogen bonds have been studied with vibrational spectroscopy in the infrared and near-infrared regions. The focus is primarily on spectra recorded in the near-infrared regions, which in these studies are dominated by O-H and N-H stretching overtones...

  6. Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus.

    Science.gov (United States)

    Walther, L E; Asenov, D R; Di Martino, E

    2011-04-01

    Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

  7. The Mauna Kea Observatories Near-Infrared Filter Set. III. Isophotal Wavelengths and Absolute Calibration

    CERN Document Server

    Tokunaga, A T

    2005-01-01

    The isophotal wavelengths, flux densities, and AB magnitudes for Vega (alpha Lyr) are presented for the Mauna Kea Observatories near-infrared filter set. We show that the near-infrared absolute calibration for Vega determined by Cohen et al. and Megessier are consistent within the uncertainties, so that either absolute calibration may be used.

  8. Detecting and Segregating Black Tip-Damaged Wheat Kernels Using Visible and Near Infrared Spectroscopy

    Science.gov (United States)

    Detection of individual wheat kernels with black tip symptom (BTS) and black tip damage (BTD) was demonstrated using near infrared reflectance spectroscopy (NIRS) and silicon light-emitting-diode (LED) based instruments. The two instruments tested, a single kernel near-infrared spectroscopy instrume...

  9. Colonic Marking With Near-Infrared, Light-Emitting, Diode-Activated Indocyanine Green for Laparoscopic Colorectal Surgery.

    Science.gov (United States)

    Nagata, Jun; Fukunaga, Yosuke; Akiyoshi, Takashi; Konishi, Tsuyoshi; Fujimoto, Yoshiya; Nagayama, Satoshi; Yamamoto, Noriko; Ueno, Masashi

    2016-02-01

    Accurate identification of the location of colorectal lesions is crucial during laparoscopic surgery. Endoscopic marking has been used as an effective preoperative marker for tumor identification. We investigated the feasibility and safety of an imaging method using near-infrared, light-emitting, diode-activated indocyanine green fluorescence in colorectal laparoscopic surgery. This was a single-institution, prospective study. This study was conducted in a tertiary referral hospital. We enrolled 24 patients who underwent laparoscopic surgery. Indocyanine green and India ink were injected into the same patients undergoing preoperative colonoscopy for colon cancer. During subsequent laparoscopic resection of colorectal tumors, the colon was first observed with white light. Then, indocyanine green was activated with a light-emitting diode at 760 nm as the light source. Near-infrared-induced fluorescence showed tumor location clearly and accurately in all 24 of the patients. All of the patients who underwent laparoscopic surgery after marking had positive indocyanine green staining at the time of surgery. Perioperative complications attributed to dye use were not observed. This study is limited by the cost of indocyanine green detection, the timing of the colonoscopy and tattooing in relation to the operation and identification with indocyanine green, and the small size of the series. These data suggest that our novel method for colonic marking with fluorescence imaging of near-infrared, light-emitting, diode-activated indocyanine green is feasible and safe. This method is useful, has no adverse effects, and can be used for perioperative identification of tumor location. Near-infrared, light-emitting, diode-activated indocyanine green has potential use as a colonic marking agent.

  10. Soil profile organic carbon prediction with Visible Near Infrared Reflec-tance spectroscopy based on a national database

    DEFF Research Database (Denmark)

    Deng, Fan; Knadel, Maria; Peng, Yi

    (ele-vation, slope, profile curvature). All the soil profile cores were taken by a 1 m long hydraulic auger with plastic liners inside. A Labspec 5100 equipped with a contact probe was used to acquire spectra at (350-2500 nm) in each 5 cm depth interval. The results show that after the removal......This study focuses on the application of the Danish national soil Visible Near Infrared Re-flectance spectroscopy (NIRs) database for predicting SOC in a field. The Conditioned Latin hypercube sam-pling (cLHS) method was used for the selection of 120 soil profiles based on DualEM21s and DEM data...

  11. PRAXIS: a near infrared spectrograph optimised for OH suppression

    Science.gov (United States)

    Ellis, S. C.; Bauer, S.; Bland-Hawthorn, J.; Case, S.; Content, R.; Fechner, T.; Giannone, D.; Haynes, R.; Hernandez, E.; Horton, A. J.; Klauser, U.; Lawrence, J. S.; Leon-Saval, S. G.; Lindley, E.; Löhmannsröben, H.-G.; Min, S.-S.; Pai, N.; Roth, M.; Shortridge, K.; Staszak, Nicholas F.; Tims, Julia; Xavier, Pascal; Zhelem, Ross

    2016-08-01

    Atmospheric emission from OH molecules is a long standing problem for near-infrared astronomy. PRAXIS is a unique spectrograph, currently in the build-phase, which is fed by a fibre array that removes the OH background. The OH suppression is achieved with fibre Bragg gratings, which were tested successfully on the GNOSIS instrument. PRAXIS will use the same fibre Bragg gratings as GNOSIS in the first implementation, and new, less expensive and more efficient, multicore fibre Bragg gratings in the second implementation. The OH lines are suppressed by a factor of 1000, and the expected increase in the signal-to-noise in the interline regions compared to GNOSIS is a factor of 9 with the GNOSIS gratings and a factor of 17 with the new gratings. PRAXIS will enable the full exploitation of OH suppression for the first time, which was not achieved by GNOSIS due to high thermal emission, low spectrograph transmission, and detector noise. PRAXIS will have extremely low thermal emission, through the cooling of all significantly emitting parts, including the fore-optics, the fibre Bragg gratings, a long length of fibre, and a fibre slit, and an optical design that minimises leaks of thermal emission from outside the spectrograph. PRAXIS will achieve low detector noise through the use of a Hawaii-2RG detector, and a high throughput through an efficient VPH based spectrograph. The scientific aims of the instrument are to determine the absolute level of the interline continuum and to enable observations of individual objects via an IFU. PRAXIS will first be installed on the AAT, then later on an 8m class telescope.

  12. Crosstalk study of near infrared InGaAs detectors

    Science.gov (United States)

    Li, Xue; Tang, Hengjing; Li, Tao; Fan, Cui; Shao, Xiumei; Li, Jianwei; Wei, Jun; Gong, Haimei

    2016-05-01

    Crosstalk characteristics of high density FPA detectors attract widespread attention in the application of electro-optical systems. Crosstalk characteristics of near-infrared (NIR) InGaAs photodiodes and focal plane arrays (FPAs) were studied in this paper. The mesa type detector was investigated by using laser beam induced current technique (LBIC) to measure the absorption outside the designed photosensitive area, and the results show that the excess absorption enlarges the crosstalk of the adjacent pixels. The structure optimization using the effective absorption layer between the pixels can effectively reduce the crosstalk to 2.5%. The major crosstalk components of the optimization photodiode come from the electronic signal caused by carrier lateral diffusion. For the planar type detectors, test structures were used to compare the crosstalk of different structures, and the guard ring structure shows good suppression of the crosstalk. Then the back-illuminated 32x32 InGaAs photodiodes with 30μm pitch were designed, and LBIC was used to measure its lateral diffusion of the effective carriers and fill factor of photosensitive area. The results indicate that the fill factor of detectors can reach up to 98% when the diffusion region is optimized, and the minimum response exists between two neighborhood pixels. Based on these crosstalk measurement results and optimizing structure designs, the linear InGaAs photodiodes were designed and thus the InGaAs FPA assembly was fabricated. The assembly shows higher electro-optical performance and good improvement on crosstalk. The assembly was applied in infrared imaging system and modulation transfer function (MTF) of FPA assembly was calculated to be above 0.50. The clear image based on FPA assembly was obtained.

  13. The near-infrared spectrum of ethynyl radical.

    Science.gov (United States)

    Le, Anh T; Hall, Gregory E; Sears, Trevor J

    2016-08-21

    Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a (2)Σ(+) state at 6696 cm(-1), a second (2)Σ(+) state at 7088 cm(-1), and a (2)Π state at 7110 cm(-1). By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. The observed states contain both X(2)Σ(+) and A(2)Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. The case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants.

  14. Near-infrared dyes for molecular probes and imaging

    Science.gov (United States)

    Patonay, Gabor; Beckford, Garfield; Strekowski, Lucjan; Henary, Maged; Kim, Jun Seok; Crow, Sidney

    2009-02-01

    Near-Infrared (NIR) fluorescence has been used both as an analytical tool as molecular probes and in in vitro or in vivo imaging of individual cells and organs. The NIR region (700-1100 nm) is ideal with regard to these applications due to the inherently lower background interference and the high molar absorptivities of NIR chromophores. NIR dyes are also useful in studying binding characteristics of large biomolecules, such as proteins. Throughout these studies, different NIR dyes have been evaluated to determine factors that control binding to biomolecules, including serum albumins. Hydrophobic character of NIR dyes were increased by introducing alkyl and aryl groups, and hydrophilic moieties e.g., polyethylene glycols (PEG) were used to increase aqueous solubility. Recently, our research group introduced bis-cyanines as innovative NIR probes. Depending on their microenvironment, bis-cyanines can exist as an intramolecular dimer with the two cyanines either in a stacked form, or in a linear conformation in which the two subunits do not interact with each other. In this intramolecular H-aggregate, the chromophore has a low extinction coefficient and low fluorescence quantum yield. Upon addition of biomolecules, the H-and D- bands are decreased and the monomeric band is increased, with concomitant increase in fluorescence intensity. Introduction of specific moieties into the NIR dye molecules allows for the development of physiological molecular probes to detect pH, metal ions and other parameters. Examples of these applications include imaging and biomolecule characterizations. Water soluble dyes are expected to be excellent candidates for both in vitro and in vivo imaging of cells and organs.

  15. The near-infrared spectrum of ethynyl radical

    Science.gov (United States)

    Le, Anh T.; Hall, Gregory E.; Sears, Trevor J.

    2016-08-01

    Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a 2Σ+ state at 6696 cm-1, a second 2Σ+ state at 7088 cm-1, and a 2Π state at 7110 cm-1. By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. The observed states contain both X2Σ+ and A2Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. The case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants.

  16. Development of silicon-germanium visible-near infrared arrays

    Science.gov (United States)

    Zeller, John W.; Rouse, Caitlin; Efstathiadis, Harry; Haldar, Pradeep; Lewis, Jay S.; Dhar, Nibir K.; Wijewarnasuriya, Priyalal; Puri, Yash R.; Sood, Ashok K.

    2016-05-01

    Photodetectors based on germanium which do not require cooling and can provide good near-infrared (NIR) detection performance offer a low-cost alternative to conventional infrared sensors based on material systems such as InGaAs, InSb, and HgCdTe. As a result of the significant difference in thermal expansion coefficients between germanium and silicon, tensile strain incorporated into Ge epitaxial layers deposited on Si utilizing specialized growth processes can extend the operational range of detection to 1600 nm and longer wavelengths. We have fabricated Ge based PIN photodetectors on 300 mm diameter Si wafers to take advantage of high throughput, large-area complementary metal-oxide semiconductor (CMOS) technology. This device fabrication process involves low temperature epitaxial deposition of Ge to form a thin p+ (boron) Ge seed/buffer layer, and subsequent higher temperature deposition of a thicker Ge intrinsic layer. This is followed by selective ion implantation of phosphorus of various concentrations to form n+ Ge regions, deposition of a passivating oxide cap, and then top copper contacts to complete the PIN detector devices. Various techniques including transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) have been employed to characterize the material and structural properties of the epitaxially grown layers and fabricated detector devices, and these results are presented. The I-V response of the photodetector devices with and without illumination was also measured, for which the Ge based photodetectors consistently exhibited low dark currents of around ~1 nA at -1 V bias.

  17. [Proximate analysis of straw by near infrared spectroscopy (NIRS)].

    Science.gov (United States)

    Huang, Cai-jin; Han, Lu-jia; Liu, Xian; Yang, Zeng-ling

    2009-04-01

    Proximate analysis is one of the routine analysis procedures in utilization of straw for biomass energy use. The present paper studied the applicability of rapid proximate analysis of straw by near infrared spectroscopy (NIRS) technology, in which the authors constructed the first NIRS models to predict volatile matter and fixed carbon contents of straw. NIRS models were developed using Foss 6500 spectrometer with spectra in the range of 1,108-2,492 nm to predict the contents of moisture, ash, volatile matter and fixed carbon in the directly cut straw samples; to predict ash, volatile matter and fixed carbon in the dried milled straw samples. For the models based on directly cut straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.92% and 0.76% for moisture, 0.94% and 0.84% for ash, 0.88% and 0.82% for volatile matter, and 0.75% and 0.65% for fixed carbon, respectively. For the models based on dried milled straw samples, the determination coefficient of independent validation (R2v) and standard error of prediction (SEP) were 0.98% and 0.54% for ash, 0.95% and 0.57% for volatile matter, and 0.78% and 0.61% for fixed carbon, respectively. It was concluded that NIRS models can predict accurately as an alternative analysis method, therefore rapid and simultaneous analysis of multicomponents can be achieved by NIRS technology, decreasing the cost of proximate analysis for straw.

  18. Near-infrared (NIR) optogenetics using up-conversion system

    Science.gov (United States)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

    2015-03-01

    Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

  19. Effect of mechanical optical clearing on near-infrared spectroscopy.

    Science.gov (United States)

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations.

  20. Spitzer and near-infrared observations of the young supernova remnant 3C397

    Science.gov (United States)

    Rho, Jeonghee; Jarrett, Tom

    2016-06-01

    We present Spitzer IRS, IRAC and MIPS observations and near-infrared imaging and spectroscopy of the young supernova remnant 3C397 (G41.1-0.2). Near-infrared observations were made using the Palomar 200 inch telescope. Both mid- and near-infrared spectra are dominated by Fe lines and near-infrared imaging shows bright Fe emission with a shell-like morphology. There is no molecular hydrogen line belong to the SNR and some are in background. The Ni, Ar, S and Si lines are detected using IRS and hydrogen recombination lines are detected in near-infrared. Two nickel lines at 18.24 and 10.69 micron are detected. 3C397 is ejecta-dominated, and our observations support 3C397 to be a Type Ia supernova.

  1. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Marion, G. H.; Kirshner, R. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Burns, C. R.; Freedman, W. L.; Persson, S. E. [Carnegie Observatories, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Winge, C. [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Kromer, M.; Gall, E. E. E. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching bei Muenchen (Germany); Gerardy, C. L.; Hoeflich, P. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Im, M.; Jeon, Y. [CEOU/Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of); Nugent, P. E. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94611 (United States); Pignata, G. [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Stanishev, V., E-mail: hsiao@lco.cl [CENTRA - Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  2. Performance improvement of a near-infrared acetylene sensor system by reducing residual amplitude modulation

    Science.gov (United States)

    He, Qixin; Zheng, Chuantao; Liu, Huifang; Li, Bin; Wang, Yiding; Tittel, Frank K.

    2017-05-01

    A near-infrared acetylene (C2H2) sensor was experimentally demonstrated by using a tunable diode laser absorption spectroscopy (TDLAS) technique as well as a second-harmonic wavelength modulation spectroscopy technique. A near-infrared distributed feedback (DFB) laser was used as a light source, and an interference-free absorption line located at the vibration overtone band near 1.53 µm was selected for the detection of C2H2. A self-developed, open-reflective gas sensing probe with a 30 cm path length was adopted as the C2H2 absorption pool. In order to reduce the residual amplitude modulation (RAM) caused by wavelength modulation, a divider pretreatment module was introduced into the traditional dual-channel detection structure. The line shape distortion of the extracted 2f signal was eliminated by the reduction of RAM. Under general laboratory conditions (1 atm, 25 °C), a minimum detection limit (MDL) of 540 ppbv was achieved with an averaging time of 68 s while the MDL without reducing the RAM is up to 1.03 ppmv. A good linear relationship was observed between the amplitude of the 2f signal and the C2H2 concentration within the range of 50-2000 ppm. Long-term measurements were carried out to verify the stability of the system. Using an optical fiber to connect the DFB laser with the probe, the probe can be placed in a faraway field for long-distance, in situ measurement.

  3. Optical and near-infrared linear polarization of low and intermediate-gravity ultracool dwarfs

    Science.gov (United States)

    Miles-Páez, P. A.; Zapatero Osorio, M. R.; Pallé, E.; Peña Ramírez, K.

    2017-04-01

    We aim to study the optical and near-infrared linear polarimetric properties of a sample of young M7-L7 dwarfs (≈ 1-500 Myr) with spectroscopic signatures of low- and intermediate-gravity atmospheres. We collected optical (RIZ) and near-infrared (YJHKs) linear polarimetry images on various time-scales from ∼0.2 h to months. Linear polarization degrees in the interval 0-1.5 per cent (I and J bands) were measured with accuracies ranging from ±0.1 to ±0.9 per cent depending on the observing filter and the target brightness. We found that the young field dwarfs in our sample show similar polarimetric degrees at both I and J bands, and that there is no obvious trend with the spectral type. The two Taurus sources in our sample show intense levels of J-band linear polarization probably due to surrounding discs. By compiling data from the literature for high-gravity M7-L7 dwarfs with likely ages ≥500 Myr, we did not observe any apparent difference in the linear polarimetry intensity between the young and old samples that could be ascribed to differing atmospheric gravities. Polarimetric variability with peak to peak amplitudes up to 1.5 per cent is detected on scales of about a rotation in two out of four targets that were monitored over several hours. Long-term polarimetric variability is also detected in nearly all dwarfs of the sample with data spanning months to years.

  4. Near infrared pulsed light for permanent hair reduction in Fitzpatrick skin types IV and V

    Directory of Open Access Journals (Sweden)

    Pratik Thacker

    2016-01-01

    Full Text Available Background: Excessive hair on the face is a significant cause for distress amongst women. Permanent hair reduction methods including lasers and pulsed light devices are increasingly being used. Aims: The aim of this study is to evaluate the efficacy and safety of near infrared pulsed light source for permanent hair reduction in women seeking treatment for excessive hair growth on the upper lip and chin. Settings and Design: This was a prospective observational study done at a tertiary care hospital in South India. Materials and Methods: Women above 18 years of age were observed for six sittings of the treatment for excessive hair over the upper lip and chin using a near infrared intense pulsed light device. Efficacy was evaluated by measuring percentage hair reduction using digital photography. Further, efficacy amongst women with polycystic ovarian syndrome (PCOS was compared with those without PCOS. Side effects were noted. Statistical Analysis Used: Student′s unpaired t-test using the software SPSS version 16. Results: Percentage hair reduction at the end of 6 sittings in 24 women for the upper lip and chin was 52.87% and 73.81%, respectively. Out of the 24 women, 12 had PCOS and the difference in hair reduction in these women was statistically insignificant when compared to that observed in those without PCOS. Only two patients experienced side effects in the form of mild pain and discomfort. Conclusions: Intense pulsed light is a safe and efficacious tool for permanent hair reduction over the upper lip and chin, efficacy being similar in patients with or without PCOS.

  5. Titania coated upconversion nanoparticles for near-infrared light triggered photodynamic therapy.

    Science.gov (United States)

    Lucky, Sasidharan Swarnalatha; Muhammad Idris, Niagara; Li, Zhengquan; Huang, Kai; Soo, Khee Chee; Zhang, Yong

    2015-01-27

    Because of the limited penetration depth of visible light that generally excites most of the available photosensitizers (PSs), conventional photodynamic therapy (PDT) is limited to the treatment of superficial and flat lesions. Recently, the application of deep penetrating near-infrared (NIR) light excitable upconversion nanoparticles (UCNs) in conjunction with PDT has shown to have clear potential in the treatment of solid tumors due to its ability to penetrate thick tissue. However, various constructs developed so far have certain limitations such as poor or unstable PS loading, reducing their therapeutic efficacy and limiting their application to solution or cell-based studies. In this work, we present a method to fabricate uniform core-shell structured nanoconstruct with a thin layer of photocatalyst or PS-titanium dioxide (TiO2) stably coated on individual UCN core. Our design allows controllable and highly reproducible PS loading, preventing any leakage of PS compared to previously developed nanoconstructs, thus ensuring repeatable PDT results. Further surface modification of the developed nanoconstructs with polyethylene glycol (PEG) rendered them biocompatible, demonstrating good therapeutic efficacy both in vitro and in vivo.

  6. Synthesis of gold nanostructures with optical properties within the near-infrared window for biomedical applications

    Science.gov (United States)

    Garcia-Soto, Mariano de Jesus

    The work reported in this dissertation describes the design and synthesis of different gold nanoshells with strong absorption coefficients at the near-infrared region (NIR) of the spectrum, and includes preliminary studies of their use for the photo-induced heating of pancreatic cancer cells and ex vivo tissues. As the emphasis was on gold nanoshells with maximum extinctions located at 800 nm, the methods explored for their synthesis led us to the preparation of silica-core and hollow gold nanoshells of improved stability, with maximum extinctions at or beyond the targeted within the near-infrared window. The synthesis of silica-core gold nanoshells was investigated first given its relevance as one of the pioneering methods to produce gold nanostructures with strong absorption and scattering coefficients in the visible and the near-infrared regions of the spectrum. By using a classical method of synthesis, we explored the aging of the precursor materials and the effect of using higher concentrations than the customary for the reduction of gold during the shell growth. We found that the aging for one week of the as-prepared or purified precursors, namely, the gold cluster suspensions, and the seeded silica particles, along with higher concentrations of gold in the plating solution, produced fully coated nanoshells of 120 nm in size with smooth surfaces and maximum extinctions around 800 nm. Additional work carried out to reduce the time and steps in the synthesis of silica-core gold nanoshells, led us to improve the seeding step by increasing the ionic strength of the cluster suspension, and also to explore the growth of gold on tin-seeded silica nanoparticles. The synthesis of hollow gold nanoshells (HGS) of with maximum extinctions at the NIR via the galvanic replacement of silver nanoparticles for gold in solution was explored next. A first method explored led us to obtain HGS with maximum extinctions between 650 and 800 nm and sizes between 30 and 80 nm from

  7. Spectra Transfer Between a Fourier Transform Near-Infrared Laboratory and a Miniaturized Handheld Near-Infrared Spectrometer.

    Science.gov (United States)

    Hoffmann, Uwe; Pfeifer, Frank; Hsuing, Chang; Siesler, Heinz W

    2016-05-01

    The aim of this contribution is to demonstrate the transfer of spectra that have been measured on two different laboratory Fourier transform near-infrared (FT-NIR) spectrometers to the format of a handheld instrument by measuring only a few samples with both spectrometer types. Thus, despite the extreme differences in spectral range and resolution, spectral data sets that have been collected and quantitative as well as qualitative calibrations that have been developed thereof, respectively, over a long period on a laboratory instrument can be conveniently transferred to the handheld system. Thus, the necessity to prepare completely new calibration samples and the effort required to develop calibration models when changing hardware platforms is minimized. The enabling procedure is based on piecewise direct standardization (PDS) and will be described for the data sets of a quantitative and a qualitative application case study. For this purpose the spectra measured on the FT-NIR laboratory spectrometers were used as "master" data and transferred to the "target" format of the handheld instrument. The quantitative test study refers to transmission spectra of three-component liquid solvent mixtures whereas the qualitative application example encompasses diffuse reflection spectra of six different current polymers. To prove the performance of the transfer procedure for quantitative applications, partial least squares (PLS-1) calibrations were developed for the individual components of the solvent mixtures with spectra transferred from the master to the target instrument and the cross-validation parameters were compared with the corresponding parameters obtained for spectra measured on the master and target instruments, respectively. To test the retention of the discrimination ability of the transferred polymer spectra sets principal component analyses (PCAs) were applied exemplarily for three of the six investigated polymers and their identification was demonstrated by

  8. Discovery of the Near-infrared Counterpart to the Luminous Neutron-star Low-mass X-Ray Binary GX 3+1

    NARCIS (Netherlands)

    van den Berg, M.; Homan, J.; Fridriksson, J.K.; Linares, M.

    2014-01-01

    Using the High Resolution Camera on board the Chandra X-ray Observatory, we have measured an accurate position for the bright persistent neutron star X-ray binary and atoll source GX 3+1. At a location that is consistent with this new position, we have discovered the near-infrared (NIR) counterpart

  9. A Brief Review on the Use of Functional Near-Infrared Spectroscopy (fNIRS) for Language Imaging Studies in Human Newborns and Adults

    Science.gov (United States)

    Quaresima, Valentina; Bisconti, Silvia; Ferrari, Marco

    2012-01-01

    Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have…

  10. A Brief Review on the Use of Functional Near-Infrared Spectroscopy (fNIRS) for Language Imaging Studies in Human Newborns and Adults

    Science.gov (United States)

    Quaresima, Valentina; Bisconti, Silvia; Ferrari, Marco

    2012-01-01

    Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have…

  11. In vivo comparison of near infrared lasers for skin welding.

    Science.gov (United States)

    Tabakoğlu, Haşim Ozgür; Gülsoy, Murat

    2010-05-01

    The skin closure abilities of near infrared lasers and suturing were compared by histological examination and mechanical tensile tests during a 21-day healing period. One-centimeter incisions on the dorsal skin of Wistar rats were treated by one of the closing techniques: (a) soldering, using an 809 nm diode laser (0.5 W, 5 s) with 25% bovine serum albumin (BSA) and 2.5 mg/ml indocyanine green (ICG); (b) direct welding with a 980 nm diode laser (0.5 W, 5 s); (c) direct welding with a 1,070 nm fiber laser (0.5 W, 5 s); (d) suturing. Six spots (79.61 J/cm(2) for each spot) were applied through the incisions. Healing was inspected on the 1st, 4th, 7th, 14th, and 21st post-operative days. The closure index (CI), thermally altered area (TAA), granulation area (GA) and epidermal thickness (ET) were determined by histological examination. Tensile tests were performed at a 5 mm/min crosshead speed up to the first opening along the incision. Immediate superficial closure with high CI values was found for the laser-irradiated incisions at the early phase of recovery. Clear welds without thermal damage were observed for the group irradiated at 1,070 nm. For the sutured group, the incisions remained unclosed for the first day, and openings through the incision were observed. At the end of the 21-day recovery period, no differences between experimental groups were observed in terms of the CI, GA and ET values. However, the tensile strength of the groups irradiated at 980 nm and 1,070 nm was found to be higher than that of the sutured incisions. The laser welding techniques were found to be reliable in terms of immediate and mechanically strong closure compared with suturing. Of them, 1,070 nm laser welding yielded noticeably stronger bonds, with minimal scarring at the end of the 21-days of recovery.

  12. Near infrared spectroscopy in animal science production: principles and applications

    Directory of Open Access Journals (Sweden)

    Roberto Riovanto

    2010-01-01

    Full Text Available Near infrared (NIR is one of the techniques belonging to vibrational spectroscopy. Its radiation (750 to 2500nm interacts with organic matter, and the absorption spectrum is rich in chemical and physical information of organic molecules. In order to extract valuable information on the chemical properties of samples, it is necessary to mathematically process spectral data by chemometric tools. The most important part in the development of an NIR method is building the predicting model generally called calibration. NIR spectroscopy has several advantages over other analytical techniques: rapidity of analysis, no use of chemicals, minimal or no samples preparation, easily applicable in different work environments (on/in/at line applications. On the other hand, NIR spectroscopy has some disadvantages: low ability to predict compounds at low concentration (<0.1%, necessity of accurate analysis as reference, development of calibration models required high trained personnel, need of a large and up-to-date calibration data set (often difficult to obtain, difficulties to transfer calibration among instruments, initial high financial investments. In the feed industry, NIR spectroscopy is used for: feed composition, digestibility (in vivo, in vitro, in situ, traceability assessment (to avoid possible frauds. As far as animal products are concerned, NIR spectroscopy has been used to determine the main composition of meat, milk, fish, cheese, eggs. Furthermore, it was also used to predict some physical properties (tenderness, WHC (Water Holding Capacity, drip loss, colour and pH in meat; coagulation ability in milk; freshness, flavour and other sensorial parameters in cheese. Interesting applications of NIR spectroscopy regard issues like: determination of animal products’ authenticity and the detection of adulteration (in order to prevent frauds, discrimination PDO (Protected Designation of Origin and PGI (Protected Geographical Indication from other non

  13. Bilateral near-infrared spectroscopy for detecting traumatic vascular injury.

    Science.gov (United States)

    Van Haren, Robert M; Ryan, Mark L; Thorson, Chad M; Namias, Nicholas; Livingstone, Alan S; Proctor, Kenneth G

    2013-09-01

    Extremity wounds account for most battlefield injuries. Clinical examination may be unreliable by medics or first responders, and continuous assessment by experienced practitioners may not be possible on the frontline or during transport. Near-infrared spectroscopy (NIRS) provides continuous, noninvasive monitoring of tissue oxygen saturation (StO2), but its use is limited by inter-patient and intra-patient variability. We tested the hypothesis that bilateral NIRS partially addresses the variability problem and can reliably identify vascular injury after extremity trauma. This prospective study consisted of 30 subjects: 20 trauma patients with extremity injury and 10 healthy volunteers. Bilateral StO2 tissue sensors were placed on the thenar eminence or medial plantar surface. Injured and non-injured extremities within the same patient (ΔStO2) were compared using Wilcoxon signed ranks test. Receiver operating characteristic curves were generated and areas under the curve (AUCs) were calculated for ΔStO2 of 6, 10, and 15. Values are expressed as median (interquartile range). Trauma patients were age 31 y (23 y), 85% male, with injury severity score of 9 (5). There were seven arterial and three venous injuries. Most involved the lower extremity (n = 16; 80%) and resulted from a penetrating mechanism (n = 14; 70%). ΔStO2 between limbs was 20.4 (10.4) versus 2.4 (3.0) (P vascular injury versus patients and volunteers with no vascular injury. ΔStO2 reliably identified any vascular injury (AUC, 0.975; P < 0.001), whereas pulse examination alone or in combination with Doppler exam could detect only arterial injury. A ΔStO2 of 6 had the greatest sensitivity and specificity (AUC, 0.900; P < 0.001). Continuous monitoring of bilateral limbs with NIRS detects changes in perfusion resulting from arterial or venous injury and may offer advantages over serial manual measurements of pulses or Doppler signals. This technique may be most relevant in military and disaster

  14. Localizing the focus of ischemic stroke with near infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To evaluate the changes in near infrared spectroscopy (NIRS) absorptive properties induced by cerebral ischemia. Methods A dual wavelength (760?nm and 850?nm) NIRS system measuring total hemoglobin concentration changes was constructed. Twenty Sprague-Dawley rats were used to set up middle cerebral artery occlusion (MCAO) model that had a stable ischemia focus on the cortex. We used NIRS to localize the ischemia focus that was confirmed with magnetic resonance imaging (MRI) and triphenyltetrazonlium chloride brain staining. The cortical ischemia area and the geometric configuration of the NIRS topograms were compared with those from MRI and the anatomical samples for the same rat. Results The reconstructed NIRS topograms showed that there was an optical density decreased area on the left cortex of the rats with MCAO model. The mean ischemia area as shown in NIRS images was 19.50?mm2 (19.50±0.35?mm2, n=20). Anatomical samples showed that the mean ischemic area located in the NIRS measurement area was 18.46?mm2  (18.46±0.38?mm2, n=20). For MRI, the mean ischemia area located in the NIRS measurement area was 20.71?mm2  (20.71±0.27?mm2, n=20). There were no significant differences among NIRS, MRI and anatomical samples (F(2,57)=2.47, P>0.05) for defining the ischemia area. The results showed that there was a significant correlation among NIRS, MRI (r=0.782, P<0.05) and anatomical sample (r=0.851, P<0.05) for the same cortical ischemia area. Meanwhile, the location and geometric configuration of the ischemia focus shown by NIRS were identified by MRI and anatomical samples, though the NIRS images had worse spatial resolution. Conclusions NIRS showed a good agreement with MRI and anatomical samples in the ischemic area and location determination of the infarction focus for the rat MCAO model. The study suggests that NIRS can non-invasively trace cortical hemodynamic changes induced by ischemia in real time.

  15. [Application of near infrared reflectance spectroscopy to predict meat chemical compositions: a review].

    Science.gov (United States)

    Tao, Lin-Li; Yang, Xiu-Juan; Deng, Jun-Ming; Zhang, Xi

    2013-11-01

    In contrast to conventional methods for the determination of meat chemical composition, near infrared reflectance spectroscopy enables rapid, simple, secure and simultaneous assessment of numerous meat properties. The present review focuses on the use of near infrared reflectance spectroscopy to predict meat chemical compositions. The potential of near infrared reflectance spectroscopy to predict crude protein, intramuscular fat, fatty acid, moisture, ash, myoglobin and collagen of beef, pork, chicken and lamb is reviewed. This paper discusses existing questions and reasons in the current research. According to the published results, although published results vary considerably, they suggest that near-infrared reflectance spectroscopy shows a great potential to replace the expensive and time-consuming chemical analysis of meat composition. In particular, under commercial conditions where simultaneous measurements of different chemical components are required, near infrared reflectance spectroscopy is expected to be the method of choice. The majority of studies selected feature-related wavelengths using principal components regression, developed the calibration model using partial least squares and modified partial least squares, and estimated the prediction accuracy by means of cross-validation using the same sample set previously used for the calibration. Meat fatty acid composition predicted by near-infrared spectroscopy and non-destructive prediction and visualization of chemical composition in meat using near-infrared hyperspectral imaging and multivariate regression are the hot studying field now. On the other hand, near infrared reflectance spectroscopy shows great difference for predicting different attributes of meat quality which are closely related to the selection of calibration sample set, preprocessing of near-infrared spectroscopy and modeling approach. Sample preparation also has an important effect on the reliability of NIR prediction; in particular

  16. Near-infrared anti-Stokes photoluminescence of PbS QDs embedded in glasses.

    Science.gov (United States)

    Xiong, Yuda; Liu, Chao; Wang, Jing; Han, Jianjun; Zhao, Xiujian

    2017-03-20

    Near-infrared photoluminescence properties of PbS QDs embedded in glasses were investigated upon below-bandgap excitation. PbS QDs were precipitated in the glasses upon thermal treatment. Near-infrared anti-Stokes photoluminescence (ASPL) from PbS QDs was observed. Dependence of the ASPL on size and excitation power indicated that ASPL was phonon-assisted one-photon process. These near-infrared anti-Stokes photoluminescence of PbS QDs in glasses have potential applications for light conversion and laser cooling.

  17. Near-infrared photodetectors utilizing MoS{sub 2}-based heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Park, Min Ji; Min, Jung Ki; Yi, Sum-Gyun; Kim, Joo Hyoung; Yoo, Kyung-Hwa, E-mail: khyoo@yonsei.ac.kr [Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Oh, Jeseung [ProteomeTech Inc., Seoul 120-749 (Korea, Republic of)

    2015-07-28

    Near-infrared photodetectors are developed using graphene/MoS{sub 2} and WSe{sub 2}/MoS{sub 2} vertical heterojunctions. These heterojunctions exhibit diode-rectifying behavior in the dark and enhanced photocurrent upon near-infrared irradiation. The photocurrent increases with increasing near-infrared power, leading to the photoresponsibility of 0.14 and 0.3 A W{sup −1} for the graphene/MoS{sub 2} and WSe{sub 2}/MoS{sub 2} heterojunctions, respectively, which are much higher than the photoresponsibility reported for a multilayer MoS{sub 2} phototransistor.

  18. Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

    Science.gov (United States)

    Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Huang, Jianhua Z.; Kanbur, Shashi M.; Ngeow, Chow-Choong

    2017-10-01

    We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK s . We use densely sampled I-band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K s . We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

  19. SN 2005cs in M51 II. Complete Evolution in the Optical and the Near-Infrared

    CERN Document Server

    Pastorello, A; Zampieri, L; Navasardyan, H; Taubenberger, S; Smartt, S J; Arkharov, A A; Baernbantner, O; Barwig, H; Benetti, S; Birtwhistle, P; Botticella, M T; Cappellaro, E; Del Principe, M; Di Mille, F; Di Rico, G; Dolci, M; Elias-Rosa, N; Efimova, N V; Fiedler, M; Harutyunyan, A; Hoeflich, P A; Kloehr, W; Larionov, V M; Lorenzi, V; Maund, J R; Napoleone, N; Ragni, M; Richmond, M; Ries, C; Spiro, S; Temporin, S; Turatto, M; Wheeler, J C

    2009-01-01

    We present the results of the one year long observational campaign of the type II-plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool Galaxy). This extensive dataset makes SN 2005cs the best observed low-luminosity, 56Ni-poor type II-plateau event so far and one of the best core-collapse supernovae ever. The optical and near-infrared spectra show narrow P-Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about 1000 km/s) of the ejected material. The optical light curves cover both the plateau phase and the late-time radioactive tail, until about 380 days after core-collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 days. In addition to optical observations, we also present near-infrared light curves that (together with already published UV observations) allow us to construct for the first time a reliable bolometric light...

  20. YOUNG STELLAR OBJECT SEARCH TOWARD THE BOUNDARY OF THE CENTRAL MOLECULAR ZONE WITH NEAR-INFRARED POLARIMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Tatsuhito; Nagata, Tetsuya [Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Nishiyama, Shogo; Kwon, Jungmi [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Tamura, Motohide, E-mail: yosikawa@kusastro.kyoto-u.ac.jp, E-mail: nagata@kusastro.kyoto-u.ac.jp, E-mail: shogo.nishiyama@nao.ac.jp [Department of Astronomy, University of Tokyo, Mitaka, Tokyo 181-0015 (Japan)

    2014-08-01

    We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (–1.°4 ≲ l ≲ –0.°3 and 1.°0 ≲ l ≲ 2.°9, |b| ≲ 0.°1), using the near-infrared polarimetric camera SIRPOL on the 1.4 m Infrared Survey Facility telescope. We have selected 112 intrinsically polarized sources on the basis of the estimate of interstellar polarization on Stokes Q/I – U/I planes. The selected sources are brighter than K{sub S} = 14.5 mag and have polarimetric uncertainty δP < 1%. Ten of these distinctive polarized sources are fit well with spectral energy distributions of young stellar objects when using the photometry in the archive of the Spitzer Space Telescope mid-infrared data. However, many sources have spectral energy distributions of normal stars suffering from heavy interstellar extinction; these might be stars behind dark clouds. Due to the small number of distinctive polarized sources and candidates of young stellar objects, we cannot judge if they are declining in number outside the Central Molecular Zone. Many massive candidates for young stellar objects in the literature have only small intrinsic polarization. This might suggest that their masses are 4-15 M {sub ☉}, whose intrinsic polarization has been expected to be small.

  1. Near-Infrared properties of the X-ray emitting young stellar objects in the Carina Nebula

    CERN Document Server

    Preibisch, Thomas; Irwin, Mike; Lewis, James R; King, Robert R; McCaughrean, Mark J; Zinnecker, Hans; Townsley, Leisa; Broos, Patrick

    2011-01-01

    Abbreviated Abstract: The near-infrared study of the Carina Nebula in this paper builds on the results of the Chandra Carina Complex Project (CCCP), that detected 14368 X-ray sources in the 1.4 square-degree survey region, an automatic source classification study that classified 10714 of these as very likely young stars in Carina, and an analysis of their clustering properties. We used HAWK-I at the ESO VLT to conduct a very deep near-IR survey with sub-arcsecond angular resolution, covering about 1280 square-arcminutes. The HAWK-I images reveal more than 600000 individual infrared sources, whereby objects as faint as J ~ 23, H ~ 22, and Ks ~ 21 are detected at S/N >= 3. While less than half of the Chandra X-ray sources have counterparts in the 2MASS catalog, the ~5 mag deeper HAWK-I data reveal infrared counterparts to 6636 (= 88.8%) of the 7472 Chandra X-ray sources in the HAWK-I field. We analyze near-infrared color-color and color-magnitude diagrams to derive information about the extinctions, infrared ex...

  2. Primary Sources. Update: Teachers' Views on Common Core State Standards

    Science.gov (United States)

    Scholastic Inc. and the Bill & Melinda Gates Foundation, 2014

    2014-01-01

    Scholastic and the Bill & Melinda Gates Foundation fielded the third edition of the "Primary Sources" survey of America's teachers in July 2013 (see ED562664). Twenty thousand pre-K through grade 12 public school teachers responded, sharing their perspectives on issues important to their profession, including the Common Core State…

  3. Obscuration in AGNs: near-infrared luminosity relations and dust colors

    CERN Document Server

    Burtscher, L; Davies, R I; Janssen, A; Lutz, D; Rosario, D; Contursi, A; Genzel, R; Gracia-Carpio, J; Lin, M -Y; Schnorr-Mueller, A; Sternberg, A; Sturm, E; Tacconi, L

    2015-01-01

    We combine two approaches to isolate the AGN luminosity at near-infrared wavelengths and relate the near-IR pure AGN luminosity to other tracers of the AGN. Using integral-field spectroscopic data of an archival sample of 51 local AGNs, we estimate the fraction of non-stellar light by comparing the nuclear equivalent width of the stellar 2.3 micron CO absorption feature with the intrinsic value for each galaxy. We compare this fraction to that derived from a spectral decomposition of the integrated light in the central arc second and find them to be consistent with each other. Using our estimates of the near-IR AGN light, we find a strong correlation with presumably isotropic AGN tracers. We show that a significant offset exists between type 1 and type 2 sources in the sense that type 1 sources are 7 (10) times brighter in the near-IR at log L_MIR = 42.5 (log L_X = 42.5). These offsets only becomes clear when treating infrared type 1 sources as type 1 AGNs. All AGNs have very red near-to-mid-IR dust colors. T...

  4. Comparison of Two Methodologies for Calibrating Satellite Instruments in the Visible and Near-Infrared

    Science.gov (United States)

    Barnes, Robert A.; Brown, Steven W.; Lykke, Keith R.; Guenther, Bruce; Butler, James J.; Schwarting, Thomas; Turpie, Kevin; Moyer, David; DeLuccia, Frank; Moeller, Christopher

    2015-01-01

    Traditionally, satellite instruments that measure Earth-reflected solar radiation in the visible and near infrared wavelength regions have been calibrated for radiance responsivity in a two-step method. In the first step, the relative spectral response (RSR) of the instrument is determined using a nearly monochromatic light source such as a lamp-illuminated monochromator. These sources do not typically fill the field-of-view of the instrument nor act as calibrated sources of light. Consequently, they only provide a relative (not absolute) spectral response for the instrument. In the second step, the instrument views a calibrated source of broadband light, such as a lamp-illuminated integrating sphere. The RSR and the sphere absolute spectral radiance are combined to determine the absolute spectral radiance responsivity (ASR) of the instrument. More recently, a full-aperture absolute calibration approach using widely tunable monochromatic lasers has been developed. Using these sources, the ASR of an instrument can be determined in a single step on a wavelength-by-wavelength basis. From these monochromatic ASRs, the responses of the instrument bands to broadband radiance sources can be calculated directly, eliminating the need for calibrated broadband light sources such as lamp-illuminated integrating spheres. In this work, the traditional broadband source-based calibration of the Suomi National Preparatory Project (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is compared with the laser-based calibration of the sensor. Finally, the impact of the new full-aperture laser-based calibration approach on the on-orbit performance of the sensor is considered.

  5. Theoretical Comparison of Optical Properties of Near-Infrared Colloidal Plasmonic Nanoparticles

    Science.gov (United States)

    Liu, Kai; Xue, Xiaozheng; Furlani, Edward P.

    2016-09-01

    We study optical properties of near-infrared absorbing colloidal plasmonic nanostructures that are of interest for biomedical theranostic applications: SiO2@Au core-shell particles, Au nanocages and Au nanorods. Full-wave field analysis is used to compare the absorption spectra and field enhancement of these structures as a function of their dimensions and orientation with respect to the incident field polarization. Absorption cross-sections of structures with the same volume and LSPR wavelength are compared to quantify differential performance for imaging, sensing and photothermal applications. The analysis shows that while the LSPR of each structure can be tuned to the NIR, particles with a high degree of rotational symmetry, i.e. the SiO2@Au and nanocage particles, provide superior performance for photothermal applications because their absorption is less sensitive to their orientation, which is random in colloidal applications. The analysis also demonstrates that Au nanocages are advantaged with respect to other structures for imaging, sensing and drug delivery applications as they support abundant E field hot spots along their surface and within their open interior. The modeling approach presented here broadly applies to dilute colloidal plasmonic nanomaterials of arbitrary shapes, sizes and material constituents and is well suited for the rational design of novel plasmon-assisted theranostic applications.

  6. Supermassive Black Holes and Their Host Galaxies - I. Bulge luminosities from dedicated near-infrared data

    CERN Document Server

    Läsker, Ronald; van de Ven, Glenn

    2013-01-01

    In an effort to secure, refine and supplement the relation between central Supermassive Black Hole masses (Mbh), and the bulge luminosities of their host galaxies, (Lbul), we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured Mbh, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope (CFHT). A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sersic-bulge + exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observe in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings and envelope...

  7. Formaldehyde sensing with plasmonic near-infrared optical fiber grating sensors

    Science.gov (United States)

    González-Vila, Á.; Debliquy, M.; Lahem, D.; Mégret, P.; Caucheteur, C.

    2016-04-01

    A tilted fiber Bragg grating is photo-inscribed in the core of a single-mode optical fiber, leading to the coupling of cladding mode resonances all along a wide region of the near-infrared spectrum. The grating is then coated with a thin film of gold in order to create a metal-dielectric interface. This way, light propagating through the cladding of the optical fiber is able to excite a surface plasmon wave on the outer interface. As sensitive element, a molecularly imprinted polymer is deposited by electropolymerization as a thin film around the previous gold coating. The thickness of the polymer is controlled by means of the surface plasmon resonance signature in order to preserve a correct surrounding refractive index sensitivity when used in a gaseous environment. The chosen polymer has an affinity to formaldehyde, which is a volatile organic compound worth to detect, especially because of its toxicity for the human being. We report a global wavelength shift of the grating cladding mode resonances in the presence of formaldehyde in gaseous state. This shift is due to a change in the refractive index of the polymer when it bounds to the target molecules. The sensor exhibits a linear response, together with a low limit of detection.

  8. 450 Days of Type II SN 2013ej in Optical and Near-Infrared

    CERN Document Server

    Yuan, Fang; Valenti, S; Sollerman, J; Seitenzahl, I R; Pastorello, A; Schulze, S; Chen, T -W; Childress, M J; Fraser, M; Fremling, C; Kotak, R; Ruiter, A J; Schmidt, B P; Smartt, S J; Taddia, F; Terreran, G; Tucker, B E; Barbarino, C; Benetti, S; Elias-Rosa, N; Gal-Yam, A; Howell, D A; Inserra, C; Kankare, E; Lee, M Y; Li, K L; Maguire, K; Margheim, S; Mehner, A; Ochner, P; Sullivan, M; Tomasella, L; Young, D R

    2016-01-01

    We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 days after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude M$_\\rm{V}$ = -17.6) but a small $^{56}$Ni production of ~0.023 M$_\\odot$. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the H{\\alpha} profile typical for a Type IIL. During transition to the radioactive decay tail at ~100 days, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from $^{56}$Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral model...

  9. A Smart Near-Infrared Fluorescence Probe for Selective Detection of Tau Fibrils in Alzheimer's Disease.

    Science.gov (United States)

    Seo, Yujin; Park, Kwang-Su; Ha, Taewoong; Kim, Mi Kyoung; Hwang, Yu Jin; Lee, Junghee; Ryu, Hoon; Choo, Hyunah; Chong, Youhoon

    2016-11-16

    Development of a novel, tau-selective smart near-infrared fluorescence (NIRF) probe was attempted by combining the previously identified core scaffold 3,5-dimethoxy-N,N-dimethylaniline-4-yl moiety, with the characteristic donor-π-acceptor architecture of the smart NIRF Aβ probes DANIR-2c and MCAAD-3. A series of compounds (2 and 3) were prepared, which were identified as "turn-on" NIRF probes for the visual detection of tau aggregates and Aβ fibrils (λem = 650 nm, Stokes shifts = 70-110 nm). In particular, combination of the 3,5-dimethoxy-N,N-dimethylanilin-4-yl moiety and the donor part of MCAAD-3 endowed the resulting probes, 3g and 3h, with significant selectivity toward tau aggregates (selectivity for tau over Aβ = 5.7 and 3.8); they showed much higher fluorescence intensities upon binding to tau aggregates (FItau = 49 and 108) than when bound to Aβ fibrils (FIAβ = 9 and 28). Quantitative analysis of binding affinities and fluorescence properties of 3g and 3h revealed that microenvironment-sensitive molecular rotor-like behavior, rather than binding affinity to the target, is responsible for their selective turn-on fluorescence detection of tau fibrils. Selective fluorescent labeling of tau fibrils by 3g and 3h was further demonstrated by immunofluorescence staining of human Alzheimer's disease brain sections, which showed colocalization of the probes (3g and 3h) and phosphorylated tau antibody.

  10. The Norma cluster (ACO3627): II. The near infrared K_s-band luminosity function

    CERN Document Server

    Skelton, R E; Kraan-Korteweg, R C

    2009-01-01

    A deep K_s-band photometric catalogue of galaxies at the core of the rich, nearby Norma cluster (ACO3627) is presented. The survey covers about 45 by 45 square arcmin (slightly less than 1/3 Abell radius), which corresponds to approx. 0.8 Mpc^2 at the adopted distance (v_cmb/H0) of 70 Mpc of this cluster. The survey is estimated to be complete to a magnitude of M_Ks <~ -19.5 mag. This extends into the dwarf regime, 6 magnitudes below M_Ks*. The catalogue contains 390 objects, 235 of which are classified as likely or definite galaxies and 155 as candidate galaxies. The Ks-band luminosity function (LF) is constructed from the photometric sample, using a spectroscopic subsample to correct for fore- and background contamination. We fit a Schechter function with a characteristic magnitude of M_Ks* = -25.39 \\pm 0.80 mag and faint-end slope of alpha = -1.26 \\pm 0.10 to the data. The shape of the LF is similar to those found in previous determinations of the cluster LF, in both optical and near infrared. The Schec...

  11. 450 d of Type II SN 2013ej in optical and near-infrared

    Science.gov (United States)

    Yuan, Fang; Jerkstrand, A.; Valenti, S.; Sollerman, J.; Seitenzahl, I. R.; Pastorello, A.; Schulze, S.; Chen, T.-W.; Childress, M. J.; Fraser, M.; Fremling, C.; Kotak, R.; Ruiter, A. J.; Schmidt, B. P.; Smartt, S. J.; Taddia, F.; Terreran, G.; Tucker, B. E.; Barbarino, C.; Benetti, S.; Elias-Rosa, N.; Gal-Yam, A.; Howell, D. A.; Inserra, C.; Kankare, E.; Lee, M. Y.; Li, K. L.; Maguire, K.; Margheim, S.; Mehner, A.; Ochner, P.; Sullivan, M.; Tomasella, L.; Young, D. R.

    2016-09-01

    We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude MV = -17.6) but a small 56Ni production of ˜0.023 M⊙. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the Hα profile typical for a Type IIL. During transition to the radioactive decay tail at ˜100 d, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from 56Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a MZAMS = 12-15 M⊙ progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.

  12. [Rapid prediction of annual ring density of Paulownia elongate standing tress using near infrared spectroscopy].

    Science.gov (United States)

    Jiang, Ze-Hui; Wang, Yu-Rong; Fei, Ben-Hua; Fu, Feng; Hse, Chung-Yun

    2007-06-01

    Rapid prediction of annual ring density of Paulownia elongate standing trees using near infrared spectroscopy was studied. It was non-destructive to collect the samples for trees, that is, the wood cores 5 mm in diameter were unthreaded at the breast height of standing trees instead of fallen trees. Then the spectra data were collected by autoscan method of NIR. The annual ring density was determined by mercury immersion. And the models were made and analyzed by the partial least square (PLS) and full cross validation in the 350-2 500 nm wavelength range. The results showed that high coefficients were obtained between the annual ring and the NIR fitted data. The correlation coefficient of prediction model was 0.88 and 0.91 in the middle diameter and bigger diameter, respectively. Moreover, high coefficients of correlation were also obtained between annual ring density laboratory-determined and the NIR fitted data in the middle diameter of Paulownia elongate standing trees, the correlation coefficient of calibration model and prediction model were 0.90 and 0.83, and the standard errors of calibration (SEC) and standard errors of prediction(SEP) were 0.012 and 0.016, respectively. The method can simply, rapidly and non-destructively estimate the annual ring density of the Paulownia elongate standing trees close to the cutting age.

  13. Theoretical Comparison of Optical Properties of Near-Infrared Colloidal Plasmonic Nanoparticles

    Science.gov (United States)

    Liu, Kai; Xue, Xiaozheng; Furlani, Edward P.

    2016-01-01

    We study optical properties of near-infrared absorbing colloidal plasmonic nanostructures that are of interest for biomedical theranostic applications: SiO2@Au core-shell particles, Au nanocages and Au nanorods. Full-wave field analysis is used to compare the absorption spectra and field enhancement of these structures as a function of their dimensions and orientation with respect to the incident field polarization. Absorption cross-sections of structures with the same volume and LSPR wavelength are compared to quantify differential performance for imaging, sensing and photothermal applications. The analysis shows that while the LSPR of each structure can be tuned to the NIR, particles with a high degree of rotational symmetry, i.e. the SiO2@Au and nanocage particles, provide superior performance for photothermal applications because their absorption is less sensitive to their orientation, which is random in colloidal applications. The analysis also demonstrates that Au nanocages are advantaged with respect to other structures for imaging, sensing and drug delivery applications as they support abundant E field hot spots along their surface and within their open interior. The modeling approach presented here broadly applies to dilute colloidal plasmonic nanomaterials of arbitrary shapes, sizes and material constituents and is well suited for the rational design of novel plasmon-assisted theranostic applications. PMID:27665922

  14. On-line near infrared monitoring of ammonium and dry matter in biosturry for robust biogas production

    DEFF Research Database (Denmark)

    Madsen, Michael; Ihunegbo, Felicia N.; Holm-Nielsen, Jens Bo

    2012-01-01

    Heterogeneous substrates fed into agricultural biogas plants originate from many sources with resulting quality fluctuations potentially inhibiting the process. Biogas yield can be substantially increased by optimisation of the organic dry matter load. In this study, near infrared spectroscopy...... be applied for optimising the efficiency of current and future biogas plants, as well as in biorefinery contexts converting heterogeneous bioslurry, energy crops, and wastes into value-added products. Adding model transfer capabilities, it is indicated that handheld instrumentation can play a vital role...... in bringing NIR technology directly in the field, and onto the plant floor – the implications for reliable biogas NIR process monitoring and control are significant....

  15. Near-infrared Polarimetric Study of the N159/N160 Star-forming Complex in the Large Magellanic Cloud

    Science.gov (United States)

    Kim, Jaeyeong; Jeong, Woong-Seob; Pyo, Jeonghyun; Pak, Soojong; Park, Won-Kee; Kwon, Jungmi; Tamura, Motohide

    2017-03-01

    We present near-infrared polarimetric results for the N159/N160 star-forming complex in the Large Magellanic Cloud with SIRPOL, the polarimeter of the Infrared Survey Facility. We separated foreground sources using their visual extinction derived from near-infrared photometric data. The 45 young stellar candidates and 2 high-excitation blobs were matched with our sources, and 12 of them showed high polarization that did not originate from the interstellar dust. We made a polarimetric catalog of 252, 277, and 89 sources at the J, H, and K s bands, respectively. Based on the ratios of the polarization degree between these bands, we verify that the origin of these polarized sources is the dichroic extinction from the interstellar dust aligned by the magnetic field and that the ratios follow a power-law dependence of {P}λ ∼ {λ }-0.9. The linear polarization vectors projected onto the Hα image of the complex turned out to follow the local magnetic field structure. The vector map overlaid on dust and gas emissions shows the close correlation between the magnetic field structure and surrounding interstellar medium. We suggest that the derived magnetic field structure supports the sequential formation scenario of the complex.

  16. Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center

    CERN Document Server

    Shahzamanian, B; Zajacek, M; Valencia-S., M; Sabha, N; Moser, L; Parsa, M; Peissker, F; Straubmeier, C

    2016-01-01

    We investigate an infrared-excess source called G2 or Dusty S-cluster Object (DSO) moving on a highly eccentric orbit around the Galaxy's central black hole, Sgr A*. We use, for the first time, near-infrared polarimetric imaging data to determine the nature and the properties of the DSO, and obtain an improved K_s-band identification of this source in median polarimetry images of different observing years. The source starts to deviate from the stellar confusion in 2008, and it does not show any flux density variability over the years we analyzed it. We measure the polarization degree and angle of the DSO between 2008 and 2012 and conclude, based on the significance analysis on polarization parameters, that it is an intrinsically polarized source (>20%) with a varying polarization angle as it approaches Sgr A* position. DSO shows a near-infrared excess of K_s-L' > 3 that remains compact close to the pericenter of its orbit. Its observed parameters and the significant polarization obtained in this work show tha...

  17. A near-infrared fluorescent probe for monitoring ozone and imaging in living cells.

    Science.gov (United States)

    Xu, Kehua; Sun, Shuxia; Li, Jing; Li, Lu; Qiang, Mingming; Tang, Bo

    2012-01-18

    A near-infrared fluorescent probe (Trp-Cy) for endogenous ozone is presented, which exhibited a large stokes shift about 140 nm and a rapid fluorescence response to ozone with high selectivity and sensitivity.

  18. Near infrared light amplification in Gold diffused Silicon-on-Insulator waveguides

    CERN Document Server

    Stepanov, S

    2016-01-01

    We report near infrared optical amplification in gold diffused silicon-on-insulator waveguides by visible optical pumping. More then 30dB/cm gain was measured for a light carrier at a wavelength of 1.55 microns

  19. A Near-Infrared Photon Counting Camera for High Sensitivity Astronomical Observation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a Near Infrared Photon-Counting Sensor (NIRPCS), an imaging device with sufficient sensitivity to capture the spectral signatures, in the...

  20. Near Infrared Spectroscopy Facilitates Rapid Identification of Both Young and Mature Amazonian Tree Species

    National Research Council Canada - National Science Library

    Lang, Carla; Costa, Flávia Regina Capellotto; Camargo, José Luís Campana; Durgante, Flávia Machado; Vicentini, Alberto

    2015-01-01

    .... Near-infrared spectroscopy (FT-NIR) has previously been shown to be effective in species discrimination of adult plants, so if young and adults have a similar spectral signature, discriminant functions based on FT-NIR spectra of adults...

  1. Turn-key Near-Infrared Photon-Counting Detector Module for LIDAR Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and deliver a turn-key photon counting detector module for near-infrared wavelengths, based on large-area InGaAs/InP avalanche photodiodes...

  2. Use of near-infrared spectroscopy to predict energy content of commercial dog food

    National Research Council Canada - National Science Library

    Hervera, M; Castrillo, C; Albanell, E; Baucells, M D

    2012-01-01

    Near-infrared spectroscopy (NIRS) is used in the pet food industry for rapid assessment of several macronutrients and GE content, but there is little published data on its usefulness for evaluating GE and GE digestibility (GED...

  3. Water Sorption on Martian Regolith Analogs: Near-Infrared Reflectance Spectroscopy and Thermodynamics

    Science.gov (United States)

    Pommerol, A.; Schmitt, B.; Beck, P.; Brissaud, O.

    2009-03-01

    Adsorption of water by a suite of six plausible martian regolith analogs is experimentally investigated. Adsorption and desorption isotherms are measured as well as near-infrared reflectance spectra for each step of hydration/dehydration processes.

  4. Cutaneous vasoconstriction affects near-infrared spectroscopy determined cerebral oxygen saturation during administration of norepinephrine

    DEFF Research Database (Denmark)

    Sørensen, Niels Henrik Breiner; Secher, Niels H; Siebenmann, Christoph

    2012-01-01

    Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine...

  5. A New Gas Cell for High-Precision Doppler Measurements in the Near-Infrared

    CERN Document Server

    Valdivielso, L; Martín, E

    2010-01-01

    High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low-mass stars and brown dwarfs. To help to achieve an accuracy of ~m/s, we are developing a gas cell which consists of a mixture of gases whose absorption spectral lines span all over the near-infrared region. We present the most promising mixture, made of acetylene, nitrous oxide, ammonia, chloromethans and hydrocarbons. The mixture is contained in a small size 13 cm long gas cell and covers most of the H and K-bands. It also shows small absorptions in the J-band but they are few and not sharp enough for near infrared wavelength calibration. We describe the working method and experiments and compare our results with the state of the art for near infrared gas cells.

  6. Near-Infrared Wireless Optical Communication with Particulates In-Suspension over the Underwater Channel

    KAUST Repository

    Lee, It Ee

    2017-05-08

    We demonstrate a gigabit near-infrared-based underwater wireless optical communication link using an 808-nm laser diode to mitigate the particle scattering effect in turbid medium. An improvement in the error performance is observed with increasing concentrations.

  7. Chemometrical Contributions Extending the Application of Near-Infrared and Raman Spectroscopy

    NARCIS (Netherlands)

    Groot, P.J. de

    2004-01-01

    Raman and near-infrared (NIR) reflectance spectroscopy are increasingly being applied in industry and laboratories. Examples are: investigation of interactions between DNA molecules, characterizing polymer properties, and separating demolition waste. These applications demand robust systems and requ

  8. Near infrared spectroscopy and chemometrics analysis of complex traits in animal physiology

    Science.gov (United States)

    Near infrared reflectance (NIR) applications have been expanding from the traditional framework of small molecule chemical purity and composition (as defined by spectral libraries) to complex system analysis and holistic exploratory approaches to questions in biochemistry, biophysics and environment...

  9. Near infrared spectroscopy for frontal lobe oxygenation during non-vascular abdominal surgery

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Grocott, Hilary P; Secher, Niels H

    2016-01-01

    PURPOSE: Cerebral deoxygenation, as determined by near infrared spectroscopy (NIRS), seems to predict postoperative complications following cardiac surgery. We identify the type of non-vascular abdominal surgery associated with cerebral deoxygenation and/or hyperoxygenation, how such deviations...

  10. Near-infrared spectroscopy and its potential in diagnosis of vascular disease : Translational research and clinical applications

    NARCIS (Netherlands)

    Boezeman, RPE

    2016-01-01

    Near-infrared light is already successfully used for a variety of applications in medical health care, such as pulse oximetry, optical coherence tomography, and near-infrared fluorescence. This thesis examines the potential of near-infrared light used by NIRS in the detection of (patho)physiological

  11. Transcranial red and near infrared light transmission in a cadaveric model.

    Directory of Open Access Journals (Sweden)

    Jared R Jagdeo

    Full Text Available BACKGROUND AND OBJECTIVE: Low level light therapy has garnered significant interest within the past decade. The exact molecular mechanisms of how red and near infrared light result in physiologic modulation are not fully understood. Heme moieties and copper within cells are red and near infrared light photoreceptors that induce the mitochondrial respiratory chain component cytochrome C oxidase, resulting in a cascade linked to cytoprotection and cellular metabolism. The copper centers in cytochrome C oxidase have a broad absorption range that peaks around 830 nm. Several in vitro and in vivo animal and human models exist that have demonstrated the benefits of red light and near infrared light for various conditions. Clinical applications for low level light therapy are varied. One study in particular demonstrated improved durable functional outcomes status post-stroke in patients treated with near infrared low level light therapy compared to sham treatment [1]. Despite previous data suggesting the beneficial effect in treating multiple conditions, including stroke, with low level light therapy, limited data exists that measures transmission in a human model. STUDY DESIGN/MATERIALS AND METHODS: To investigate this idea, we measured the transmission of near infrared light energy, using red light for purposes of comparison, through intact cadaver soft tissue, skull bones, and brain using a commercially available LED device at 830 nm and 633 nm. RESULTS: Our results demonstrate that near infrared measurably penetrates soft tissue, bone and brain parenchyma in the formalin preserved cadaveric model, in comparison to negligible red light transmission in the same conditions. CONCLUSION: These findings indicate that near infrared light can penetrate formalin fixed soft tissue, bone and brain and implicate that benefits observed in clinical studies are potentially related to direct action of near infrared light on neural tissue.

  12. UV Written Integrated Optical Beam Combiner for Near Infrared Astronomical Interferometry

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Olivero, Massimo; Jocou, Laurent;

    2006-01-01

    A near infrared integrated optical beam combiner for astronomical interferometry is demonstrated for the first time by direct UV writing. High fringe contrast >95%, low total loss (0.7 dB), low crosstalk and broadband performance is demonstrated.......A near infrared integrated optical beam combiner for astronomical interferometry is demonstrated for the first time by direct UV writing. High fringe contrast >95%, low total loss (0.7 dB), low crosstalk and broadband performance is demonstrated....

  13. All-semiconductor metamaterial with negative refraction in the near-infrared

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Liu, Jingjing; Kildishev, Alexander V.

    2012-01-01

    When heavily doped, semiconductors such as ZnO can exhibit metallic properties thus becoming versatile building blocks for optical metamaterials. Here, we design and fabricate an all-semiconductor metamaterial and demonstrate negative refraction in the near-infrared region.......When heavily doped, semiconductors such as ZnO can exhibit metallic properties thus becoming versatile building blocks for optical metamaterials. Here, we design and fabricate an all-semiconductor metamaterial and demonstrate negative refraction in the near-infrared region....

  14. Slow-Reduction Synthesis of a Thiolate-Protected One-Dimensional Gold Cluster Showing an Intense Near-Infrared Absorption.

    Science.gov (United States)

    Takano, Shinjiro; Yamazoe, Seiji; Koyasu, Kiichirou; Tsukuda, Tatsuya

    2015-06-10

    Slow reduction of Au ions in the presence of 4-(2-mercaptoethyl)benzoic acid (4-MEBA) gave Au76(4-MEBA)44 clusters that exhibited a strong (3 × 10(5) M(-1) cm(-1)) near-infrared absorption band at 1340 nm. Powder X-ray diffraction studies indicated that the Au core has a one-dimensional fcc structure that is elongated along the {100} direction.

  15. Near-Infrared Absorption and Scattering Separated by Extended Inverted Signal Correction (EISC): Analysis of Near-Infrared Transmittance Spectra of Single Wheat Seeds

    DEFF Research Database (Denmark)

    Pedersen, Dorthe Kjær; Martens, Harald; Engelsen, Søren Balling

    2002-01-01

    A new extended method for separating, e.g., scattering from absorbance in spectroscopic measurements, extended inverted signal correction (EISC), is presented and compared to multiplicative signal correction (MSC) and existing modiŽ cations of this. EISC preprocessing is applied to near-infrared...

  16. Excitation Mechanisms of Near-Infrared Emission Lines in LINER Galaxies

    Science.gov (United States)

    Boehle, Anna

    2017-01-01

    I will present high spatial resolution, integral field spectroscopic observations of the nearby LINER (low ionization nuclear emission line region) galaxy NGC 404. LINERs are found at the centers of ~1/3 of galaxies within 40 Mpc, but their physical nature is not well understood. Although NGC 404 is thought to host a intermediate mass black hole at its center, it is unclear whether accretion onto the black hole or another mechanism such as shock excitation drives its LINER emission. We use the OSIRIS near-infrared integral field spectrograph at Keck Observatory behind laser guide star adaptive optics to map the strength and kinematics of [FeII], H2, and hydrogen recombination lines in the nucleus of NGC 404. These observations have a spatial pixel sampling of 0.5 pc and span the central 30 pc of the galaxy. We find that the ionized and molecular gas show differences in their morphology and kinematics on parsec scales. In particular, there are regions with line ratios of [FeII]/Pa-β that are much higher than previously seen in spatially integrated spectra, significantly restricting the possible excitation mechanisms of the near-infrared emission lines in this source. We are also applying these analysis techniques to 10 additional nearby LINERs, a part of a larger sample of 14 sources, to understand what drives the emission lines in these active galaxies. As a part of this program, I worked on the upgrade of the detector in the OSIRIS spectrograph, which has allowed observations for this survey obtained since January 2016 to be taken with increased instrument sensitivity of a factor of ~2 at J-band wavelengths (1.2 - 1.4 microns) and ~1.6 at H- and K-band wavelengths (1.5 - 2.4 microns). I will present results from the LINER survey, the OSIRIS detector upgrade, and also touch on related work using stellar orbits around the Milky Way supermassive black hole Sgr A* to constrain the mass and distance to our own Galactic Center.

  17. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

    Science.gov (United States)

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

    2016-07-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

  18. Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared Polarimetry

    CERN Document Server

    Nishiyama, Shogo; Hatano, Hirofumi; Kanai, Saori; Kurita, Mikio; Sato, Shuji; Matsunaga, Noriyuki; Nagata, Tetsuya; Nagayama, Takahiro; Kandori, Ryo; Nakajima, Yasushi; Kusakabe, Nobuhiko; Sato, Yaeko; Hough, James H; Sugitani, Koji; Okuda, Haruyuki

    2008-01-01

    We present a polarimetric map of a 20'x20' area toward the Galactic center. The polarization of point sources has been measured in the J, H, and Ks bands using the near-infrared polarimetric camera SIRPOL on the 1.4 m telescope IRSF. One percent or better accuracy of polarization degree is achieved for sources with J<14.5, H<13.5, and Ks<12.0. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we have obtained a polarization originating from magnetically aligned dust grains at the central region of our Galaxy of at most 1-2 kpc. The distribution of the position angles shows a peak at about 20 deg, nearly parallel to the Galactic plane, suggesting a toroidal magnetic configuration. The derived direction of the magnetic field is in good agreement with that obtained from far-infrared/submillimeter observations, which detect polarized thermal emission from dust in the molecular clouds at the Galactic center. Our results show that by subtracting foreground co...

  19. Deep Near-Infrared Universe Seen in the Subaru Deep Field

    CERN Document Server

    Totani, T

    2002-01-01

    The Subaru Deep Field provides the currently deepest K-selected sample of high-z galaxies (K' = 23.5 at 5 sigma). The SDF counts, colors, and size distributions in the near-infrared bands are carefully compared with pure-luminosity-evolution (PLE) as well as CDM-based hierarchical merging (HM) models. The very flat faint-end slope of the SDF K count indicates that the bulk (more than 90%) of cosmic background radiation (CBR) in this band is resolved, even if we take into account every known source of incompleteness. The integrated flux from the counts is only about a third of reported flux of the diffuse CBR in the same band, suggesting that a new distinct source of this missing light may be required. We discovered unusually red objects with colors of (J-K) >~ 3-4, which are even redder than the known population of EROs, and difficult to explain by passively evolving elliptical galaxies. A plausible interpretation, which is the only viable one among those we examined, is that these are dusty starbursts at hig...

  20. The Planning Process for Multi-Object Spectroscopy with the JWST Near-Infrared Spectrograph

    Science.gov (United States)

    Beck, Tracy L.; Karakla, D. M.; Shyrokov, A.; Pontoppidan, K.; Soderblom, D. R.; Valenti, J. A.; Kassin, S. A.; Gilbert, K.; Blair, W. P.; Muzerolle, J.; Tumlinson, J.; Keyes, C. D.; Pavlovsky, C. M.; LeBlanc, T.

    2014-01-01

    The Near-Infrared Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) will have a powerful multi-object spectroscopy mode using four configurable Micro-Shutter Arrays (MSAs). The contiguous MSA shutters can be opened to form slits on astronomical targets, for simultaneous spectroscopy of up to 100 sources per exposure. The NIRSpec MSA shutters are in a fixed grid pattern, and careful analysis in the observation planning process will be crucial for optimal definition of science exposures. Our goal is to maximize the number of astronomical science sources observed in the fewest number of MSA slit configurations. We are developing algorithms in the NIRSpec MSA Planning Tool (MPT) to improve the quality of planned observations using several common science observing strategies as test use cases. For example, the needs for planning extremely deep exposures on a small number of JWST discovered z > 10 galaxy candidates will differ significantly from the requirements for planning spectral observations on a representative sample of stars from a galactic star cluster catalog. In this poster, we present a high level overview of our plans to develop and optimize the MPT for the JWST NIRSpec multi-object spectroscopy mode.

  1. Near-infrared Imaging Polarimetry of GGD 27: Circular Polarization and Magnetic Field Structures

    Science.gov (United States)

    Kwon, Jungmi; Tamura, Motohide; Hough, James H.; Nagata, Tetsuya; Kusakabe, Nobuhiko; Saito, Hiro

    2016-06-01

    Near-infrared imaging polarimetry in the J, H, and K s bands was carried out for GGD 27 in the dark cloud Lynds 291. Details of an infrared reflection nebula associated with the optical nebulosity GGD 27 and the infrared nebula GGD 27 IRS are presented. Aperture photometry of 1263 point-like sources, detected in all three bands, was used to classify them based on a color-color diagram, and the linear polarization of several hundred sources was determined, with the latter used to map the magnetic field structure around GGD 27. This field, around GGD 27 IRS, appears to be associated with the extended CO outflow of IRAS 18162-2048 however, there are partly distorted or bent components in the field. The Chandrasekhar-Fermi method gives an estimate of the magnetic field strength as ˜90 μG. A region associated with GGD 27 IRS is discovered to have a circular polarization in the range of ˜2%-11% in the K s band. The circular polarization has an asymmetric positive/negative pattern and extends out to ˜ 120″ or 1.0 pc. The circular and linear polarization patterns are explained as resulting from a combination of dense inner and fainter outer lobes, suggesting episodic outflow.

  2. Photogenerating Silver Nanoparticles and Polymer Nanocomposites by Direct Activation in the Near Infrared

    Directory of Open Access Journals (Sweden)

    Lavinia Balan

    2012-01-01

    Full Text Available This work reports on an improvement of the photochemically assisted synthesis of silver nanoparticles by direct photoreduction of AgNO3 with a laser source emitting in the near infrared range (NIR. For this, polymethine dyes were used as the photoactive agents. Both the effects of central chain structure and activation intensity were investigated. The reduction kinetics was followed up by UV-Vis spectroscopy, and the particles size was evaluated by transmission electron microscopy. The results showed that light intensity affects both the average size and size distribution of Ag nanoparticles generated through this process. The particles can also be generated in situ in a photopolymerizable formulation so that metal/polymer nanocomposites become available through a one-step photoassisted process on the basis of NIR activation. The process described herein is very fast (seconds to a few minutes, and it readily lends itself to automatization for mass production of micro-optical elements implemented directly onto integrated NIR sources.

  3. Handheld low-frequency phased array near-infrared (NIR) breast cancer localizer

    Science.gov (United States)

    Liu, Qian; Chen, Yu; Luo, Qingming

    2003-07-01

    A system for rapid and precise localization of breast cancer using low frequency phased array near-infrared technique has been developed. In this system, in-phase and out-of-phase of sine-wave signals at 3 kHz modulate two light emitting diode (LED) sources respectively. And amplitude cancellation of two photon density waves will occur in the silicon-detector at the mid-plane of two sources reference. Cancellation signal is displayed by an embedded amplitude and phase detector and is displayed acoustically. The whole system is pocket-size, handheld with the dimension of 6.0cm×5.0cm×2.5cm and the weight is 140g. Experiments with phantom and animals show that the system can provide real time detection and localization of small hidden absorbing-fluorescent objects inside the highly scattering medium at the depth of 2cm with high accuracy of +/-1 ~ 2mm. The limit of object detection with 20 mA LED current is 1cm and with 40 mA is 2cm. The potential application is that it can be used for early breast cancer detection as a convenient self-examination device.

  4. Matching Performance among Visible and near Infrared Coating, Low Infrared Emitting Coating and Microwave Absorbing Coating

    Institute of Scientific and Technical Information of China (English)

    XIE Guohua; ZHANG Zuoguang; WU Ruibin

    2005-01-01

    The matching performance among the visible and near infrared conting, the low infrared emitting coating and the microwave absorbing coating was investigated. Experimental results shaw that the resulting material is characteristic of wideband effect ranging from the visible, near infrared and 3-5μm, 8- 14 μm infrared portion of the spectrum, as well as the radar region from 8 to 18 GHz when these three materials form a layerstructure material system. The microwave absorbing ability of material is hardly changed. The resonance peak moves towards lower frequency as the thickness of the visible, near infrared coating and the low infrared emitting coating increases. This problem can be resolved by controlling the thickness of the material. On the other hand,the infrared emissivity ε of the material system increases as the thickness of the visible, near infrared coating increases. This can be resolved by increasing infrared transparency of the visible and near infrared topcoating or controlling its thickness. The experimental resulting material system has spectral reflection characteristics in visible and near infrared regions that are similar to those of the natural bnckground.

  5. Development of a neurofeedback protocol targeting the frontal pole using near-infrared spectroscopy.

    Science.gov (United States)

    Kinoshita, Akihide; Takizawa, Ryu; Yahata, Noriaki; Homae, Fumitaka; Hashimoto, Ryuichiro; Sakakibara, Eisuke; Kawasaki, Shingo; Nishimura, Yukika; Koike, Shinsuke; Kasai, Kiyoto

    2016-11-01

    Neurofeedback has been studied with the aim of controlling cerebral activity. Near-infrared spectroscopy is a non-invasive neuroimaging technique used for measuring hemoglobin concentration changes in cortical surface areas with high temporal resolution. Thus, near-infrared spectroscopy may be useful for neurofeedback, which requires real-time feedback of repeated brain activation measurements. However, no study has specifically targeted neurofeedback, using near-infrared spectroscopy, in the frontal pole cortex. We developed an original near-infrared spectroscopy neurofeedback system targeting the frontal pole cortex. Over a single day of testing, each healthy participant (n = 24) received either correct or incorrect (Sham) feedback from near-infrared spectroscopy signals, based on a crossover design. Under correct feedback conditions, significant activation was observed in the frontal pole cortex (P = 0.000073). Additionally, self-evaluation of control and metacognitive beliefs were associated with near-infrared spectroscopy signals (P = 0.006). The neurofeedback system developed in this study might be useful for developing control of frontal pole cortex activation. © 2016 The Authors. Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

  6. Enhanced spatial near-infrared modulation of graphene-loaded perfect absorbers using plasmonic nanoslits.

    Science.gov (United States)

    Cai, Yijun; Zhu, Jinfeng; Liu, Qing Huo; Lin, Timothy; Zhou, Jianyang; Ye, Longfang; Cai, Zhiping

    2015-12-14

    Modulating spatial near-infrared light for ultra-compact electro-optic devices is a critical issue in optical communication and imaging applications. To date, spatial near-infrared modulators based on graphene have been reported, but they showed limited modulation effects due to the relatively weak light-graphene interaction. In combination with graphene and metallic nanoslits, we design a kind of ultrathin near-infrared perfect absorber with enhanced spatial modulation effects and independence on a wide range of incident angles. The modulated spectral shift of central wavelength is up to 258.2 nm in the near-infrared range, which is more promising in applications than state-of-the-art devices. The modulation enhancement is attributed to the plasmonic nanoslit mode, in which the optical electric field is highly concentrated in the deep subwavelength scale and the light-graphene interaction is significantly strengthened. The physical insight is deeply revealed by a combination of equivalent circuit and electromagnetic field analysis. The design principles are not only crucial for spatial near-infrared modulators, but also provide a key guide for developing active near-infrared patch nanoantennas based on graphene.

  7. Remote Identification of Pyroclastic Deposits on Mars and the Moon with Near-Infrared Spectroscopy

    Science.gov (United States)

    Horgan, B. H.; Chojnacki, M.; Lai, J. C.; Bennett, K. A.; Bell, J. F.

    2013-12-01

    major contribution from explosive volcanism to the sedimentary budget of Mars. However, one major complication is the possible contribution of glass from impact melt. While we hypothesize that very glass-rich deposits and those deposits associated with likely volcanic features are volcanic in origin, moderately glassy deposits without a volcanic context could also have an impact origin. Further work on the spectral properties of impact and volcanic deposits may aid in discriminating between these two possible interpretations. We have also applied these techniques to near-infrared spectra from the Moon Mineralogy Mapper of a series of hypothesized Vulcanian pyroclastic deposits in Oppenheimer Crater on the Moon. Our mineral maps indicate that the deposits are glass-bearing, but also exhibit evidence for mixing with pyroxene-bearing country rock, consistent with explosive Vulcanian eruptions. Glass absorption band strengths do vary between individual deposits, and correlate with variations in the abundance of mafic phases inferred from Diviner mid-infrared spectra (Bennett et al., this volume). These inter-deposit variations may be representative of variations in eruption dynamics related to factors like volatile content, plug depth, or source depth.

  8. Study of SRM critical surfaces using near infrared optical fiber spectrometry

    Science.gov (United States)

    Workman, G. L.; Thompson, G. W.; Arendale, W. A.

    1999-12-01

    The measurement and control of cleanliness for critical bonding surfaces during manufacturing provides a unique challenge in the current thrust for the use of environmentally benign processes. Of particular interest has been work performed in maintaining quality in the production of bonds in aerospace propulsion systems and the identification of possible contaminants which are detrimental to the integrity of the bondline. This work requires an in-depth study of the possible sources of contamination, methodologies to identify contaminants, discrimination between contaminants and chemical species caused by environment, and the effect of particular contaminants on the bondline integrity of the critical bonds. Current research explores the use of near infrared (NIR) optical fiber spectrometry for process monitoring of materials used in aerospace systems. Characterization of contaminants on critical bondlines for aerospace materials such as D6AC steel, aluminum alloys and graphite epoxy composites will be presented. Experiments include quantitative measurement of silicone and Conoco HD2 grease, metal hydroxides, and tape residues on solid rocket motor surfaces.

  9. Near-infrared background anisotropies from diffuse intrahalo light of galaxies.

    Science.gov (United States)

    Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Gong, Yan; Stern, Daniel; Ashby, Matthew L N; Eisenhardt, Peter R; Frazer, Christopher C; Gonzalez, Anthony H; Kochanek, Christopher S; Kozłowski, Szymon; Wright, Edward L

    2012-10-25

    Unresolved anisotropies of the cosmic near-infrared background radiation are expected to have contributions from the earliest galaxies during the epoch of reionization and from faint, dwarf galaxies at intermediate redshifts. Previous measurements were unable to pinpoint conclusively the dominant origin because they did not sample spatial scales that were sufficiently large to distinguish between these two possibilities. Here we report a measurement of the anisotropy power spectrum from subarcminute to one-degree angular scales, and find the clustering amplitude to be larger than predicted by the models based on the two existing explanations. As the shot-noise level of the power spectrum is consistent with that expected from faint galaxies, a new source population on the sky is not necessary to explain the observations. However, a physical mechanism that increases the clustering amplitude is needed. Motivated by recent results related to the extended stellar light profile in dark-matter haloes, we consider the possibility that the fluctuations originate from intrahalo stars of all galaxies. We find that the measured power spectrum can be explained by an intrahalo light fraction of 0.07 to 0.2 per cent relative to the total luminosity in dark-matter haloes of 10(9) to 10(12) solar masses at redshifts of about 1 to 4.

  10. Comparison of motion correction techniques applied to functional near-infrared spectroscopy data from children

    Science.gov (United States)

    Hu, Xiao-Su; Arredondo, Maria M.; Gomba, Megan; Confer, Nicole; DaSilva, Alexandre F.; Johnson, Timothy D.; Shalinsky, Mark; Kovelman, Ioulia

    2015-12-01

    Motion artifacts are the most significant sources of noise in the context of pediatric brain imaging designs and data analyses, especially in applications of functional near-infrared spectroscopy (fNIRS), in which it can completely affect the quality of the data acquired. Different methods have been developed to correct motion artifacts in fNIRS data, but the relative effectiveness of these methods for data from child and infant subjects (which is often found to be significantly noisier than adult data) remains largely unexplored. The issue is further complicated by the heterogeneity of fNIRS data artifacts. We compared the efficacy of the six most prevalent motion artifact correction techniques with fNIRS data acquired from children participating in a language acquisition task, including wavelet, spline interpolation, principal component analysis, moving average (MA), correlation-based signal improvement, and combination of wavelet and MA. The evaluation of five predefined metrics suggests that the MA and wavelet methods yield the best outcomes. These findings elucidate the varied nature of fNIRS data artifacts and the efficacy of artifact correction methods with pediatric populations, as well as help inform both the theory and practice of optical brain imaging analysis.

  11. Observations of the Near-infrared Spectrum of the Zodiacal Light with CIBER

    Science.gov (United States)

    Tsumura, K.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2010-08-01

    Interplanetary dust (IPD) scatters solar radiation which results in the zodiacal light that dominates the celestial diffuse brightness at optical and near-infrared wavelengths. Both asteroid collisions and cometary ejections produce the IPD, but the relative contribution from these two sources is still unknown. The low resolution spectrometer (LRS) onboard the Cosmic Infrared Background ExpeRiment (CIBER) observed the astrophysical sky spectrum between 0.75 and 2.1 μm over a wide range of ecliptic latitude. The resulting zodiacal light spectrum is redder than the solar spectrum, and shows a broad absorption feature, previously unreported, at approximately 0.9 μm, suggesting the existence of silicates in the IPD material. The spectral shape of the zodiacal light is isotropic at all ecliptic latitudes within the measurement error. The zodiacal light spectrum, including the extended wavelength range to 2.5 μm using Infrared Telescope in Space (IRTS) data, is qualitatively similar to the reflectance of S-type asteroids. This result can be explained by the proximity of S-type asteroidal dust to Earth's orbit, and the relatively high albedo of asteroidal dust compared with cometary dust.

  12. Measurement of oxygen consumption during muscle flaccidity exercise by near-infrared spectroscopy

    Science.gov (United States)

    Fukuda, K.; Fukawa, Y.

    2013-03-01

    Quantitative measurement oxygen consumption in the muscles is important to evaluate the effect of the exercise. Near-infrared spectroscopy (NIRS) is a noninvasive method for measuring muscle oxygenation. However, measurement results are affected by blood volume change due to changes in the blood pressure. In order to evaluate changes in blood volume and to improve measurement accuracy, we proposed a calculation method of three-wavelength measurement with considering the scattering factor and the measurement with monitoring blood flow for measuring the temporal change of the oxygen concentration more precisely. We applied three-wavelength light source (680nm, 808nm and 830nm) for the continued wave measurement. Two detectors (targeted detector and the reference detector) were placed near the target muscle and apart from it. We measured the blood flow by controlling the intravascular pressure and the oxygen consumption with the handgrip exercise in the forearm. The measured results show that the scattering factor contains the artifact at the surface and the blood flow in the artery and the vein in the same phase. The artifact and the blood flow in the same phase are reduced from the oxygenated and the deoxygenated hemoglobin densities. Thus our proposed method is effective for reducing the influence of the artifact and the blood flow in the same phase from the oxygen consumption measurement. Further, it is shown that the oxygen consumption is measured more accurately by subtracting the blood flow measured by the reference detector.

  13. Transmission in near-infrared optical windows for deep brain imaging.

    Science.gov (United States)

    Shi, Lingyan; Sordillo, Laura A; Rodríguez-Contreras, Adrián; Alfano, Robert

    2016-01-01

    Near-infrared (NIR) radiation has been employed using one- and two-photon excitation of fluorescence imaging at wavelengths 650-950 nm (optical window I) for deep brain imaging; however, longer wavelengths in NIR have been overlooked due to a lack of suitable NIR-low band gap semiconductor imaging detectors and/or femtosecond laser sources. This research introduces three new optical windows in NIR and demonstrates their potential for deep brain tissue imaging. The transmittances are measured in rat brain tissue in the second (II, 1,100-1,350 nm), third (III, 1,600-1,870 nm), and fourth (IV, centered at 2,200 nm) NIR optical tissue windows. The relationship between transmission and tissue thickness is measured and compared with the theory. Due to a reduction in scattering and minimal absorption, window III is shown to be the best for deep brain imaging, and windows II and IV show similar but better potential for deep imaging than window I.

  14. Nanodissection of human chromosomes with near-infrared femtosecond laser pulses.

    Science.gov (United States)

    König, K; Riemann, I; Fritzsche, W

    2001-06-01

    Near-infrared laser pulses of a compact 80-MHz femtosecond laser source at 800 nm, a mean power of 15-100 mW, 170-fs pulse width, and millisecond beam dwell times at the target have been used for multiphoton-mediated nanoprocessing of human chromosomes. By focusing of the laser beam with high-numerical-aperture objectives of a scanning microscope to diffraction-limited spots and with light intensities of terawatts per cubic centimeter, precise submicrometer holes and cuts in human chromosomes have been processed by single-point exposure and line scans. A minimum FWHM cut size of ~100 nm during a partial dissection of chromosome 1, which is below the diffraction-limited spot size, and a minimum material removal of ~0.003mum (3) were determined by a scanning-force microscope. The plasma-induced ablated material corresponds to ~1/400 of the chromosome 1 volume and to ~65x10(3) base pairs of chromosomal DNA. A complete dissection could be performed with FWHM cut sizes below 200 nm. High-repetition-frequency femtosecond lasers at low mean power in combination with high-numerical-aperture focusing optics appear therefore as appropriate noncontact tools for nanoprocessing of bulk and (or) surfaces of transparent materials such as chromosomes. In particular, the noninvasive inactivation of certain genomic regions on single chromosomes within living cells becomes possible.

  15. Near infrared photometric and optical spectroscopic study of 22 low mass star clusters embedded in nebulae

    Science.gov (United States)

    Soares, J. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2008-02-01

    Aims:Among the star clusters in the Galaxy, those embedded in nebulae represent the youngest group, which has only recently been explored. The analysis of a sample of 22 candidate embedded stellar systems in reflection nebulae and/or HII environments is presented. Methods: We employed optical spectroscopic observations of stars in the directions of the clusters carried out at CASLEO (Argentina) together with near infrared photometry from the 2MASS catalogue. Our analysis is based on source surface density, colour-colour diagrams and on theoretical pre-main sequence isochrones. We take into account the field star contamination by carrying out a statistical subtraction. Results: The studied objects have the characteristics of low mass systems. We derive their fundamental parameters. Most of the cluster ages are younger than 2 Myr. The studied embedded stellar systems in reflection nebulae and/or HII region complexes do not have stars of spectral types earlier than B. The total stellar masses locked in the clusters are in the range 20-220 M⊙. They are found to be gravitationally unstable and are expected to dissolve in a timescale of a few Myr. Based on observations made at Complejo Astronómico El Leoncito, which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juan, Argentina.

  16. Near-infrared photometry of WISE J085510.74$-$071442.5

    CERN Document Server

    Osorio, M R Zapatero; Béjar, V J S; Martín, E L; Ivanov, V D; Bayo, A; Boffin, H M J; Mužić, K; Minniti, D; Beamín, J C

    2016-01-01

    (Abridged) We aim at measuring the near-infrared photometry, and deriving the mass, age, temperature, and surface gravity of WISE J085510.74-071442.5 (J0855-0714), which is the coolest known object beyond the Solar System as of today. We use publicly available data from the archives of the HST and the VLT to determine the emission of this source at 1.153 micron (F110W) and 1.575 micron (CH_4). J0855-0714 is detected at both wavelengths with signal-to-noise ratio of ~10 (F110W) and ~4 (CH_4-off) at the peak of the corresponding PSFs. This is the first detection of J0855-0714 in the H-band. We measure 26.31 +/- 0.10 and 23.22 +/- 0.35 mag in F110W and CH_4 (Vega system). J0855-0714 remains unresolved in the HST images that have a spatial resolution of 0.22". Companions at separations of 0.5 AU (similar brightness) and at ~1 AU (~1 mag fainter in the F110W filter) are discarded. By combining the new data with published photometry, we build the spectral energy distribution of J0855-0714 from 0.89 to 22.09 micron,...

  17. Fluorescent light induces neurodegeneration in the rodent nigrostriatal system but near infrared LED light does not.

    Science.gov (United States)

    Romeo, Stefania; Vitale, Flora; Viaggi, Cristina; di Marco, Stefano; Aloisi, Gabriella; Fasciani, Irene; Pardini, Carla; Pietrantoni, Ilaria; Di Paolo, Mattia; Riccitelli, Serena; Maccarone, Rita; Mattei, Claudia; Capannolo, Marta; Rossi, Mario; Capozzo, Annamaria; Corsini, Giovanni U; Scarnati, Eugenio; Lozzi, Luca; Vaglini, Francesca; Maggio, Roberto

    2017-05-01

    We investigated the effects of continuous artificial light exposure on the mouse substantia nigra (SN). A three month exposure of C57Bl/6J mice to white fluorescent light induced a 30% reduction in dopamine (DA) neurons in SN compared to controls, accompanied by a decrease of DA and its metabolites in the striatum. After six months of exposure, neurodegeneration progressed slightly, but the level of DA returned to the basal level, while the metabolites increased with respect to the control. Three month exposure to near infrared LED light (∼710nm) did not alter DA neurons in SN, nor did it decrease DA and its metabolites in the striatum. Furthermore mesencephalic cell viability, as tested by [(3)H]DA uptake, did not change. Finally, we observed that 710nm LED light, locally conveyed in the rat SN, could modulate the firing activity of extracellular-recorded DA neurons. These data suggest that light can be detrimental or beneficial to DA neurons in SN, depending on the source and wavelength. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Structure of the Large Magellanic Cloud from the Near Infrared magnitudes of Red Clump stars

    CERN Document Server

    Subramanian, Smitha

    2013-01-01

    The structural parameters, like the inclination, i and the position angle of the line of nodes (PA_lon) of the disk of the Large Magellanic Cloud (LMC) are estimated using the JH photometric data of red clump stars from the Infrared Survey Facility - Magellanic Cloud Point Source Catalog (IRSF-MCPSC). The observed LMC region is divided into several sub-regions and stars in each region are cross identified with the optically identified red clump stars to obtain the near infrared magnitudes. The peak values of H magnitude and (J-H) colour of the observed red clump distribution are obtained by fitting a profile to the distributions and also by taking the average value of magnitude and colour of the red clump stars in the bin with largest number. Then the dereddened peak H0 magnitude of the red clump stars in each sub-region is obtained. The RA, Dec and relative distance from the center of each sub-region are converted into x, y & z Cartesian coordinates. A weighted least square plane fitting method is applie...

  19. Chemical Imaging of Heterogeneous Muscle Foods Using Near-Infrared Hyperspectral Imaging in Transmission Mode.

    Science.gov (United States)

    Wold, Jens Petter; Kermit, Martin; Segtnan, Vegard Herman

    2016-06-01

    Foods and biomaterials are, in general, heterogeneous and it is often a challenge to obtain spectral data which are representative for the chemical composition and distribution. This paper presents a setup for near-infrared (NIR) transmission imaging where the samples are completely trans-illuminated, probing the entire sample. The system measures falling samples at high speed and consists of an NIR imaging scanner covering the spectral range 760-1040 nm and a powerful line light source. The investigated samples were rather big: whole pork bellies of thickness up to 5 cm, salmon fillets with skin, and 3 cm thick model samples of ground pork meat. Partial least square regression models for fat were developed for ground pork and salmon fillet with high correlations (R = 0.98 and R = 0.95, respectively). The regression models were applied at pixel level in the hyperspectral transmission images and resulted in images of fat distribution where also deeply embedded fat clearly contributed to the result. The results suggest that it is possible to use transmission imaging for rapid, nondestructive, and representative sampling of very heterogeneous foods. The proposed system is suitable for industrial use. © The Author(s) 2016.

  20. Near-Infrared-Light-Assisted Photothermal Polymerization for Transdermal Hydrogelation and Cell Delivery.

    Science.gov (United States)

    Lee, Hwangjae; Chung, Solchan; Kim, Min-Gon; Lee, Luke P; Lee, Jae Young

    2016-07-01

    Photopolymerization of hydrogels has been widely used to encapsulate cells and support their growth in 3D environments. However, common light sources (i.e., ultraviolet and visible light) strongly interact with biological systems and are therefore inappropriate for in vivo applications, such as transdermal polymerization. Using near infrared (NIR) light that minimally interacts with living tissues, this study investigates NIR light-assisted photothermal polymerization (NAPP) of diacrylated polyethylene glycol (PEGDA), in which interactions between NIR light and gold nanorods activate a thermal initiator (i.e., AIPH), resulting in generation of radicals for polymerization of PEGDA. Gelation parameters, including precursor concentrations and NIR power, are investigated to minimize the use of initiator and temperature increases (adhesive peptide moiety (Arg-Gly-Asp) into the gel system further enables prolongation of cell viability during incubation up to 7 d. NAPP results in successful transdermal gelation and good viability of the transplanted cells. Thus, this new cell encapsulation approach, demonstrated for the first time in this study, will benefit various applications, including cell delivery and remote control over cellular environments. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Design of a portable near infrared system for topographic imaging of the brain in babies

    Science.gov (United States)

    Vaithianathan, Tharshan; Tullis, Iain D. C.; Everdell, Nicholas; Leung, Terence; Gibson, Adam; Meek, Judith; Delpy, David T.

    2004-10-01

    A portable topographic near-infrared spectroscopic (NIRS) imaging system has been developed to provide real-time temporal and spatial information about the cortical response to stimulation in unrestrained infants. The optical sensing array is lightweight, flexible, and easy to apply to infants ranging from premature babies in intensive care to children in a normal environment. The sensor pad consists of a flexible double-sided circuit board onto which are mounted multiple sources (light-emitting diodes) and multiple detectors (p-i-n photodiodes), all electrically encapsulated in silicone rubber. The control electronics are housed in a box with a medical grade isolated power supply and linked to a PC fitted with a data acquisition card, the signal acquisition and analysis being performed using LABVIEW™. The signal output is displayed as an image of oxy- and deoxyhemoglobin concentration ([HbO2], [Hb]) changes at a frame rate of 3 Hz. Experiments have been conducted on phantoms to determine the sensitivity of the system, and the results have been compared to theoretical simulations. The system has been tested in volunteers by imaging changes in forearm muscle oxygenation, following blood pressure cuff occlusion to obtain typical [Hb] and [HbO2] plots.

  2. An in vitro hemodynamic tissue model to study the variations in flow using near infrared spectroscopy

    Science.gov (United States)

    Ranga, Raghavender; Kashyap, Dheerendra; Behbehani, Khosrow; Liu, Hanli

    2005-04-01

    Determination of blood flow changes will be helpful for evaluation of tumor prognosis and therapy. Our study is to develop an in vitro hemodynamic phantom model, which allows us to show the feasibility of using near infrared spectroscopy (NIRS) to determine flow changes as a dynamic imaging modality to monitor tumor responses to therapy. In the hemodynamic phantom model, both single and multiple, transparent, plastic tubes were used to pass through a cylindral glass chamber. The chamber was filled with either an Intralipid solution or a soft gelatin phantom, while the tube or tubes were pumped with either an Intralipid-ink mixture or animal whole blood to simulate the tumor vasculature. The Intralipid solutions that were filled in the chamber and tubes had optical scattering and absorption properties similar to those of tumor tissues and tumor vasculature. A single-channel, broadband, NIRS system with a tungsten light source and a CCD-array spectrometer was used to quantify the changes in optical density (OD) of the intralipid-ink mixture with variations in flow rate and concentration. A single-exponential curve fit has been used to determine the time constant (τ) from the change in OD to estimate the flow rate. The obtained preliminary results show a strong correlation between changing rates of concentration and flow; a multivariable dynamic mathematical model may be also established to relate changes of Hb, HbO and blood volume with blood flow.

  3. Probing the Circumnuclear Stellar Populations of Starburst Galaxies in the Near-infrared

    CERN Document Server

    Dametto, N Z; Pastoriza, M G; Rodríguez-Ardila, A; Hernandez-Jimenez, J A; Carvalho, E A

    2014-01-01

    We employ the NASA Infrared Telescope Facility's near-infrared spectrograph SpeX at 0.8-2.4$\\mu$m to investigate the spatial distribution of the stellar populations (SPs) in four well known Starburst galaxies: NGC34, NGC1614, NGC3310 and NGC7714. We use the STARLIGHT code updated with the synthetic simple stellar populations models computed by Maraston (2005, M05). Our main results are that the NIR light in the nuclear surroundings of the galaxies is dominated by young/intermediate age SPs ($t \\leq 2\\times10^9$yr), summing from $\\sim$40\\% up to 100\\% of the light contribution. In the nuclear aperture of two sources (NGC1614 and NGC3310) we detected a predominant old SP component ($t > 2\\times10^9$yr), while for NGC34 and NGC7714 the younger component prevails. Furthermore, we found evidence of a circumnuclear star formation ring-like structure and a secondary nucleus in NGC1614, in agreement with previous studies. We also suggest that the merger/interaction experienced by three of the galaxies studied, NGC161...

  4. First Detection of Galactic Latitude Dependence of Near-Infrared Diffuse Galactic Light from DIRBE Reanalysis

    CERN Document Server

    Sano, K; Tsumura, K; Arai, T; Shirahata, M; Onishi, Y

    2016-01-01

    Observational study on near-infrared (IR) scattering properties of interstellar dust grains has been limited due to its faintness. Using all-sky maps obtained from Diffuse Infrared Background Experiment (DIRBE), we investigate the scattering property from diffuse Galactic light (DGL) measurements at 1.25, 2.2, and 3.5 {\\mu}m in addition to our recent analyses of diffuse near-IR emission (Sano et al. 2015; Sano et al. 2016). As a result, we first find that the intensity ratios of near-IR DGL to 100 {\\mu}m emission increase toward low Galactic latitudes at 1.25 and 2.2 {\\mu}m. The derived latitude dependence can be reproduced by a scattered light model of interstellar dust with a large scattering asymmetry factor g = of $0.8^{+0.2}_{-0.3}$ at 1.25 and 2.2 {\\mu}m, assuming an infinite Galaxy disk as an illuminating source. The derived asymmetry factor is comparable to the values obtained in the optical, but several times larger than that expected from a recent dust model. Since possible latitude dependence of u...

  5. Real-time near-infrared spectroscopic inspection system for adulterated sesame oil

    Science.gov (United States)

    Kang, Sukwon; Lee, Kang-jin; Son, Jaeryong; Kim, Moon S.

    2010-04-01

    Sesame seed oil is popular and expensive in Korea and has been often mixed with other less expensive vegetable oils. The objective of this research is to develop an economical and rapid adulteration determination system for sesame seed oil mixed with other vegetable oils. A recently developed inspection system consists of a light source, a measuring unit, a spectrophotometer, fiber optics, and a data acquisition module. A near-infrared transmittance spectroscopic method was used to develop the prediction model using Partial Least Square (PLS). Sesame seed oil mixed with a range of concentrations of corn, or perilla, or soybean oil was measured in 8 mm diameter glass tubes. For the model development, a correlation coefficient value of 0.98 was observed for corn, perilla, and soybean oil mixtures with standard errors of correlation of 6.32%, 6.16%, and 5.67%, respectively. From the prediction model, the correlation coefficients of corn oil, perilla oil, and soybean oil were 0.98, 0.97 and 0.98, respectively. The Standard Error of Prediction (SEP) for corn oil, perilla oil, and soybean oil were 6.52%, 6.89% and 5.88%, respectively. The results indicated that this system can potentially be used as a rapid non-destructive adulteration analysis tool for sesame seed oil mixed with other vegetable oils.

  6. Augmented reality with Microsoft HoloLens holograms for near infrared fluorescence based image guided surgery

    Science.gov (United States)

    Cui, Nan; Kharel, Pradosh; Gruev, Viktor

    2017-02-01

    Near infrared fluorescence (NIRF) based image guided surgery aims to provide vital information to the surgeon in the operating room, such as locations of cancerous tissue that should be resected and healthy tissue that should to be preserved. Targeted molecular markers, such as tumor or nerve specific probes, are used in conjunctions with NIRF imaging and display systems to provide key information to the operator in real-time. One of the major hurdles for the wide adaptation of these imaging systems is the high cost to operate the instruments, large footprint and complexity of operating the systems. The emergence of wearable NIRF systems has addressed these shortcomings by minimizing the imaging and display systems' footprint and reducing the operational cost. However, one of the major shortcomings for this technology is the replacement of the surgeon's natural vision with an augmented reality view of the operating room. In this paper, we have addressed this major shortcoming by exploiting hologram technology from Microsoft HoloLens to present NIR information on a color image captured by the surgeon's natural vision. NIR information is captured with a CMOS sensor with high quantum efficiency in the 800 nm wavelength together with a laser light illumination light source. The NIR image is converted to a hologram that is displayed on Microsoft HoloLens and is correctly co-registered with the operator's natural eyesight.

  7. Application of near-infrared spectroscopy to measurement of hemodynamic signals accompanying stimulated saliva secretion.

    Science.gov (United States)

    Sato, Hiroki; Obata, Akiko N; Moda, Ichiro; Ozaki, Kazutaka; Yasuhara, Takaomi; Yamamoto, Yukari; Kiguchi, Masashi; Maki, Atsushi; Kubota, Kisou; Koizumi, Hideaki

    2011-04-01

    We aim to test the feasibility of using near-infrared spectroscopy (NIRS) for indirect measurement of human saliva secretion in response to taste stimuli for potential application to organoleptic testing. We use an NIRS system to measure extracranial hemodynamics (Hb-signals around the temples) of healthy participants when taste stimuli are taken in their mouths. First, the Hb-signals and volume of expelled saliva (stimulated by distilled-water or sucrose-solution intake) are simultaneously measured and large Hb-signal changes in response to the taste stimuli (Hb-responses) are found. Statistical analysis show that both the Hb response and saliva volume are larger for the sucrose solution than for the distilled water with a significant correlation between them (r = 0.81). The effects of swallowing on the Hb-signals are investigated. Similar Hb responses, differing from the sucrose solution and distilled water, are obtained even though the participants swallow the mouth contents. Finally, functional magnetic resonance imaging is used to identify possible sources of the Hb signals corresponding to salivation. Statistical analysis indicates similar responses in the extracranial regions, mainly around the middle meningeal artery. In conclusion, the identified correlation between extracranial hemodynamics and the saliva volume suggests that NIRS is applicable to the measurement of hemodynamic signals accompanying stimulated saliva secretion.

  8. A Disk Wind Model for the Near-Infrared Excess Emission in Protostars

    CERN Document Server

    Bans, Alissa

    2012-01-01

    Protostellar systems, ranging from low-luminosity T Tauri and Herbig Ae stars to high-luminosity Herbig Be stars, exhibit a near-infrared (NIR) excess in their spectra that is dominated by a bump in the monochromatic luminosity with a peak near 3 microns. The bump can be approximated by a thermal emission component of temperature 1500 K that is of the order of the sublimation temperature of interstellar dust grains. In the currently popular "puffed up rim" scenario, the bump represents stellar radiation that propagates through the optically thin inner region of the surrounding accretion disk and is absorbed and reemitted by the dust that resides just beyond the dust sublimation radius, Rsub. However, this model cannot account for the strongest bumps measured in these sources, and it predicts a large secondary bounce in the interferometric visibility curve that is not observed. In this paper we present an alternative interpretation, which attributes the bump to reemission of stellar radiation by dust that is u...

  9. Optimal parameters for near infrared fluorescence imaging of amyloid plaques in Alzheimer's disease mouse models

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, S B [Harvard-MIT Division of Health Sciences and Technology, 77 Mass Ave., E25-519, Cambridge, MA 02139 (United States); Kumar, A T N; Boas, D A [Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149 13th St Charlestown, MA 02129 (United States); Bacskai, B J [Alzheimer' s Research Unit, Department of Neurology, Massachusetts General Hospital, 114 16th St, Charlestown, MA 02129 (United States)], E-mail: bbacskai@partners.org

    2009-10-21

    Amyloid-{beta} plaques are an Alzheimer's disease biomarker which present unique challenges for near-infrared fluorescence tomography because of size (<50 {mu}m diameter) and distribution. We used high-resolution simulations of fluorescence in a digital Alzheimer's disease mouse model to investigate the optimal fluorophore and imaging parameters for near-infrared fluorescence tomography of amyloid plaques. Fluorescence was simulated for amyloid-targeted probes with emission at 630 and 800 nm, plaque-to-background ratios from 1-1000, amyloid burden from 0-10%, and for transmission and reflection measurement geometries. Fluorophores with high plaque-to-background contrast ratios and 800 nm emission performed significantly better than current amyloid imaging probes. We tested idealized fluorophores in transmission and full-angle tomographic measurement schemes (900 source-detector pairs), with and without anatomical priors. Transmission reconstructions demonstrated strong linear correlation with increasing amyloid burden, but underestimated fluorescence yield and suffered from localization artifacts. Full-angle measurements did not improve upon the transmission reconstruction qualitatively or in semi-quantitative measures of accuracy; anatomical and initial-value priors did improve reconstruction localization and accuracy for both transmission and full-angle schemes. Region-based reconstructions, in which the unknowns were reduced to a few distinct anatomical regions, produced highly accurate yield estimates for cortex, hippocampus and brain regions, even with a reduced number of measurements (144 source-detector pairs)

  10. Near-infrared polarization study of L1641S

    Institute of Scientific and Technical Information of China (English)

    CHEN; Xuepeng; YAO; Yongqiang

    2005-01-01

    H-band polarimetric images and Ks-band images of star formation region L1641S are presented. Two reflection nebulae, Re50N and Re50, are in the north and south of the region, respectively. The polarization maps of two nebulae exhibit high degrees of polarization and centrosymmetric patterns, indicating the single scattering and small dust grains in the nebulae. There are two infrared sources, IRS1 and IRS2, in the nebula Re50N. IRS1 is the illuminating source of the nebulae and the driving source of CO outflow; IRS2 is suggested to provide considerable light at optical wavelengths. The high polarization in Re50N can be interpreted as surface scattering from the outflow at an inclination of 30 degrees. Based on the polarization arc structure, we further identified the bipolar structure of the nebula Re50N. The FU Orionis phenomenon in L1641S is discussed at the end of this paper.

  11. 近红外光源对光合细菌生长的影响%Influence of near-infrared on growth of photosynthetic bacteria

    Institute of Scientific and Technical Information of China (English)

    李家洲; 张冬青; 黄荣林; 赵鑫; 肖玉平

    2012-01-01

    光合细菌的光合色素能吸收近红外光进行光合作用.利用加可见光滤光镜的卤钨灯作为近红外光源,照射光合细菌,探讨其对光合细菌生长的影响.结果表明,相对于可见光,近红外光对光合细菌的生长有明显促进作用,可使最大菌体浓度提高45%以上.近红外光照强度饱和区为20W~35W之间,低于20W时,光合细菌的生长速率随光照强度升高而升高;超过50W后,近红外光对光合细菌产生抑制作用.温度和pH值2个培养参数对近红外光的光照效果没有明显的影响.%The photosynthetic pigments can absorb near-infrared lights for photosynthesis. Halogen tungsten lamp filtered with visible-light filter lens as light source, influence of photosynthetic bacteria growth was researched. The results were as follows: compared with visible-light, near-infrared lights can promote photosynthetic bacteria growth markedly and can increase the max cell concentration about 45%; the region of near-infrared light saturation was between 20W to 35W; when lower than 20W, growth rate of photosynthetic bacteria increased with light intensity increasing; when higher than 50W, near-infrared light could inhibit photosynthetic bacteria growth. The temperature and pH value had no influence on the near-infrared light effect.

  12. A near-infrared SETI experiment: A multi-time resolution data analysis

    Science.gov (United States)

    Tallis, Melisa; Maire, Jerome; Wright, Shelley; Drake, Frank D.; Duenas, Andres; Marcy, Geoffrey W.; Stone, Remington P. S.; Treffers, Richard R.; Werthimer, Dan; NIROSETI

    2016-06-01

    We present new post-processing routines which are used to detect very fast optical and near-infrared pulsed signals using the latest NIROSETI (Near-Infrared Optical Search for Extraterrestrial Intelligence) instrument. NIROSETI was commissioned in 2015 at Lick Observatory and searches for near-infrared (0.95 to 1.65μ) nanosecond pulsed laser signals transmitted by distant civilizations. Traditional optical SETI searches rely on analysis of coincidences that occur between multiple detectors at a fixed time resolution. We present a multi-time resolution data analysis that extends our search from the 1ns to 1ms range. This new feature greatly improves the versatility of the instrument and its search parameters for near-infrared SETI. We aim to use these algorithms to assist us in our search for signals that have varying duty cycles and pulse widths. We tested the fidelity and robustness of our algorithms using both synthetic embedded pulsed signals, as well as data from a near-infrared pulsed laser installed on the instrument. Applications of NIROSETI are widespread in time domain astrophysics, especially for high time resolution transients, and astronomical objects that emit short-duration high-energy pulses such as pulsars.

  13. Effect of near-infrared rays on female menstrual pain in Korea.

    Science.gov (United States)

    Lee, Jin-Min; Kim, Kye-Ha

    2017-09-01

    Most Korean women who experience menstrual pain have reported taking pain medicine and making use of complementary alternative therapies. However, because some interventions may cause side effects, more effective pain-relieving measures need to be identified. This study using a non-equivalent group design, evaluated the effects of near-infrared rays on dysmenorrhea among Korean women. The experimental group wore a near-infrared ray abdominal belt for the duration of one menstrual cycle until the end of the menstrual period, while the control group used hot packs. The level of menstrual pain, menstrual pain duration, and pain medicine use were measured. The menstrual pain, average menstrual pain duration, and use of analgesics were reduced in the near-infrared rays group. The results of this study indicate that the near-infrared ray LED belt was effective in reducing menstrual pain, menstrual pain duration compared to the use of analgesics in Korean women with dysmenorrhea. Therefore, near-infrared rays may be used to relieve menstrual pain and improve the quality of life of women with dysmenorrhea in Korea. © 2017 John Wiley & Sons Australia, Ltd.

  14. First Detection of Near-Infrared Intraday Variations in the Seyfert 1 Nucleus NGC4395

    CERN Document Server

    Minezaki, T; Kobayashi, Y; Enya, K; Suganuma, M; Tomita, H; Koshida, S; Yamauchi, M; Aoki, T

    2006-01-01

    We carried out a one-night optical V and near-infrared JHK monitoring observation of the least luminous Seyfert 1 galaxy, NGC4395, on 2004 May 1, and detected for the first time the intraday flux variations in the J and H bands, while such variation was not clearly seen for the K band. The detected J and H variations are synchronized with the flux variation in the V band, which indicates that the intraday-variable component of near-infrared continuum emission of the NGC4395 nucleus is an extension of power-law continuum emission to the near-infrared and originates in an outer region of the central accretion disk. On the other hand, from our regular program of long-term optical BVI and near-infrared JHK monitoring observation of NGC4395 from 2004 February 12 until 2005 January 22, we found large flux variations in all the bands on time scales of days to months. The optical BVI variations are almost synchronized with each other, but not completely with the near-infrared JHK variations. The color temperature of ...

  15. Unveiling the near-infrared structure of the massive-young stellar object NGC 3603 IRS 9A* with sparse aperture masking and spectroastrometry

    Science.gov (United States)

    Sanchez-Bermudez, J.; Hummel, C. A.; Tuthill, P.; Alberdi, A.; Schödel, R.; Lacour, S.; Stanke, T.

    2016-04-01

    Context. Contemporary theory holds that massive stars gather mass during their initial phases via accreting disk-like structures. However, conclusive evidence for disks has remained elusive for most massive young objects. This is mainly due to significant observational challenges: objects are rare and located at great distances within dusty, highly opaque environments. Incisive studies, even targeting individual objects, are therefore relevant to the progression of the field. NGC 3603 IRS 9A* is a young massive stellar object that is still surrounded by an envelope of molecular gas for which previous mid-infrared observations with long-baseline interferometry have provided evidence of a plausible disk of 50 mas diameter at its core. Aims: This work aims at a comprehensive study of the physics and morphology of IRS 9A at near-infrared wavelengths. Methods: New sparse aperture-masking interferometry data, taken with the near-infrared camera NACO of the Very Large Telescope (VLT) at Ks and L' wavelengths, were analyzed together with archival high-resolution H2 and Brγ lines obtained with the cryogenic high-resolution infrared schelle spectrograph (CRIRES). Results: The trends in the calibrated visibilities at Ks and L'-bands suggest the presence of a partially resolved compact object with an angular size of ≤30 mas at the core of IRS 9A, together with the presence of over-resolved flux. The spectroastrometric signal of the H2 line, obtained from the CRIRES spectra, shows that this spectral feature proceeds from the large-scale extended emission (~300 mas), while the Brγ line appears to be formed at the core of the object (~20 mas). To better understand the physics that drive IRS 9A, we have performed continuum radiative transfer modeling. Our best model supports the existence of a compact disk with an angular diameter of 20 mas, together with an outer envelope of 1'' exhibiting a polar cavity with an opening angle of ~30°. This model reproduces the MIR morphology

  16. Bimodal Imaging Using Neodymium Doped Gadolinium Fluoride Nanocrystals with Near-Infrared to Near-Infrared Downconversion Luminescence and Magnetic Resonance Properties

    OpenAIRE

    Mimun, L. Christopher; Ajithkumar, Gangadharan; Pokhrel, Madhab; Yust, Brian G.; Elliott, Zak G.; Pedraza, Francisco; Dhanale, Ashish; Tang, Liang; Lin, Ai-Ling; Dravid, Vinayak P.; Sardar, Dhiraj K.

    2013-01-01

    Here we report the synthesis, characterization and application of a multifunctional surface functionalized GdF3:Nd3+ nanophosphor that exhibits efficient near infrared (NIR) fluorescence as well as magnetic properties, which can be utilized for bimodal imaging in medical applications. The nanoparticles are small with an average size of 5 nm and form stable colloids that last for several weeks without settling, enabling the use for several biomedical and photonic applications. Their excellent ...

  17. Size-tunable and monodisperse Tm³⁺/Gd³⁺-doped hexagonal NaYbF₄ nanoparticles with engineered efficient near infrared-to-near infrared upconversion for in vivo imaging.

    Science.gov (United States)

    Damasco, Jossana A; Chen, Guanying; Shao, Wei; Ågren, Hans; Huang, Haoyuan; Song, Wentao; Lovell, Jonathan F; Prasad, Paras N

    2014-08-27

    Hexagonal NaYbF4:Tm(3+) upconversion nanoparticles hold promise for use in high contrast near-infrared-to-near-infrared (NIR-to-NIR) in vitro and in vivo bioimaging. However, significant hurdles remain in their preparation and control of their morphology and size, as well as in enhancement of their upconversion efficiency. Here, we describe a systematic approach to produce highly controlled hexagonal NaYbF4:Tm(3+) nanoparticles with superior upconversion. We found that doping appropriate concentrations of trivalent gadolinium (Gd(3+)) can convert NaYbF4:Tm(3+) 0.5% nanoparticles with cubic phase and irregular shape into highly monodisperse NaYbF4:Tm(3+) 0.5% nanoplates or nanospheres in a pure hexagonal-phase and of tunable size. The intensity and the lifetime of the upconverted NIR luminescence at 800 nm exhibit a direct dependence on the size distribution of the resulting nanoparticles, being ascribed to the varied surface-to-volume ratios determined by the different nanoparticle size. Epitaxial growth of a thin NaYF4 shell layer of ∼2 nm on the ∼22 nm core of hexagonal NaYbF4:Gd(3+) 30%/Tm(3+) 0.5% nanoparticles resulted in a dramatic 350 fold NIR upconversion efficiency enhancement, because of effective suppression of surface-related quenching mechanisms. In vivo NIR-to-NIR upconversion imaging was demonstrated using a dispersion of phospholipid-polyethylene glycol (DSPE-PEG)-coated core/shell nanoparticles in phosphate buffered saline.

  18. Real-time functional near-infrared imager

    Science.gov (United States)

    Luo, Qingming; Zeng, Shaoqun; Chance, Britton; Nioka, Shoko

    1998-08-01

    A real time functional Near-InfraRed Imager (fNIRI) was presented in this paper. We developed a continuous wave (cw) light imaging probe which includes 9 light sources and 4 pairs detectors (each pair has one 850 nm filtered detector and one 760 nm filtered detector). There are 16 measurement sections and total detection area is 9 cm X 4 cm. The detector- source uses 2.5 cm spacing. The light sources are controlled by a computer and the signals from the detectors are converted and processed in real time by the computer. The user-friendly software was programmed with Visual C++ language. Relative changes of oxy-Hb, Hb, and total blood concentration in 16 channels and the corresponding images combined by 16 channels could be displayed in real time on computer. With this cw imaging probe, we have measured motor function in motor cortex area, visual function in occipital area, and cognitive activity in frontal forehead area of the human brain when the subjects are stimulated by moving fingers, viewing a flashing light and doing an analogy test, respectively. The experimental results show that the cw imaging probe can be used for functional images of brain activity, based upon changes of oxygenation and blood volume due to the stimulus.

  19. Broadband near-infrared to visible upconversion in quantum dot-quantum well heterostructures (Conference Presentation)

    Science.gov (United States)

    Teitelboim, Ayelet; Oron, Dan

    2016-09-01

    Upconversion (UC) is a nonlinear process in which two, or more, long wavelength photons are converted to a shorter wavelength photon. This process is based on sequential absorption of two or more photons, involving metastable, long lived intermediate energy states, thus is not restricted to upconversion of coherent laser radiation as a non-coherent process. Hence, requirements for UC processes are long lived excited states, a ladder like arrangement of energy levels and a mechanism inhibiting cooling of the hot charge carrier. UC holds great promise for bioimaging, enabling spatially resolved imaging in a scattering specimen and for photovoltaic devices as a mean to surpass the Shockley-Queisser efficiency limit. Here, we present a novel luminescence upconversion nano-system based on colloidal semiconductor double quantum dots, consisting of a NIR-emitting component and a visible emitting component separated by a tunneling barrier in a spherical onion-like geometry. These dual near-infrared and visible emitting core/shell/shell PbSe/CdSe/CdS nanocrystals are shown to upconvert a broad range of NIR wavelengths to visible emission at room temperature, covering a spectral range where there are practically no alternative upconversion systems. The synthesis is a three-step process, which enables versatility and tunability of both the visible emission color and the NIR absorption edge. Using this method one can achieve a range of desired upconverted emission peak positions with a suitable NIR band gap. The physical mechanism for upconversion in this structure, as well as possible extensions and improvements will be discussed. 1 (1) Teitelboim, A.; Oron, D. ACS Nano 2015, acsnano.5b05329.

  20. Supermassive black holes and their host galaxies. II. The correlation with near-infrared luminosity revisited

    Energy Technology Data Exchange (ETDEWEB)

    Läsker, Ronald; Van de Ven, Glenn [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Ferrarese, Laura [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E2E7 (Canada); Shankar, Francesco, E-mail: laesker@mpia.de [GEPI Observatoire de Paris, CNRS, Univ. Paris Diderot, 5 Place Jules Janssen, F-92195 Meudon (France)

    2014-01-01

    We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M {sub •}, and their host galaxies' K-band bulge (L {sub bul}) and total (L {sub tot}) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M {sub •}, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations have consistent intrinsic scatter, suggesting that M {sub •} correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M {sub •}-L {sub bul} relation depends on the detail of the image decomposition, the characterization of M {sub •}-L {sub tot} does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L {sub tot} is more suitable as a tracer of SMBH mass than L {sub bul}, and that the M {sub •}-L {sub tot} relation should be used when studying the co-evolution of SMBHs and galaxies.

  1. Cancer theranostics with near-infrared light-activatable multimodal nanoparticles.

    Science.gov (United States)

    Melancon, Marites P; Zhou, Min; Li, Chun

    2011-10-18

    Nanomaterials that interact with light provide a unique opportunity for applications in biophotonic nanomedicine. Image-guided therapies could be designed based on multifunctional nanoparticles (NPs). Such NPs have a strong and tunable surface plasmon resonance absorption in the near-infrared region and can be detected using multiple imaging modalities (magnetic resonance imaging, nuclear imaging, and photoacoustic imaging). These novel nanostructures, once introduced, are expected to home in on solid tumors either via a passive targeting mechanism (i.e., the enhanced permeability and retention effect) or via an active targeting mechanism facilitated by ligands bound to their surfaces. Once the NPs reach their target tissue, their activity can then be turned on using an external stimulus. For example, photothermal conducting NPs primarily act by converting light energy into heat. As a result, the temperature in the treatment volume is elevated above the thermal damage threshold, which kills the cells. This process, termed photothermal ablation therapy (PTA), is effective, but it is also unlikely to kill all tumor cells when used alone. In addition to PTA, photothermal conducting NPs can also efficiently trigger the release of drugs and activate RNA interference. A multimodal approach, which permits simultaneous PTA therapy, chemotherapy, and therapeutic RNA interference, has the potential to completely eradicate residual diseased cells. In this Account, we provide an up-to-date review of the synthesis and characterization, functionalization, and in vitro and in vivo evaluation of NIR lightactivatable multifunctional nanostructures used for imaging and therapy. We emphasize research on hollow gold nanospheres, magnetic core-shell gold nanoshells, and semiconductor copper monosulfide NPs. We discuss three types of novel drug delivery systems in which hollow gold nanospheres are used to mediate controlled drug release.

  2. Near infrared rubidium 62P3/2,1/2→62S1/2 laser

    Science.gov (United States)

    Moran, Paul J.; Richards, Ryan M.; Rice, Christopher A.; Perram, Glen P.

    2016-09-01

    An optically pumped near infrared rubidium (Rb) pulsed, mirrorless laser has been demonstrated in a heat pipe along both the 62P3/2-62S1/2 transition at 2.73 μm and the 62P1/2-62S1/2 transition at 2.79 μm. The bleached limit, slope efficiency, and maximum laser output energy of the near infrared Rb laser scale linearly with increasing Rb density, contrary to prior results. Previously, a maximum output energy of ~5 nJ had been observed before a rollover occurred in the scaling of output energy with rubidium concentration. In this experiment, the maximum laser output energy observed was ~100 nJ, with no indication of any scaling limitation. A maximum slope efficiency of 1.7×10-4 was observed. A small percentage of the pump photons were absorbed even at the maximum Rb density attainable in the heat pipe, indicating that laser efficiency could be scaled to near the quantum efficiency. Additionally, the hyperfine structure and absorption spectral profile of the 52S1/2-62P1/2 and 52S1/2-62P3/2 (blue) pump transitions were studied using a cw pump source.

  3. Noise reduction methods in analysis of near infrared lunar occultation light curves for high angular resolution measurements

    CERN Document Server

    Baug, Tapas

    2013-01-01

    Lunar occultation (LO) technique in the near-infrared provides angular resolution down to milliarcseconds on the occulted source even with ground-based 1m class telescopes. LO observations are limited to brighter objects because they require high signal to noise ratio (S/N ~ 40) for proper extraction of angular diameter values. Hence, methods to improve the S/N ratio by reducing noise using Fourier and Wavelet transforms have been explored in this study. A sample of 54 near-infrared LO light curves observed with IR Camera at Mt Abu observatory has been used. It is seen that both Fourier and Wavelet methods have shown improvement in S/N, compared to the original data. However, the application of wavelet transforms results in slight smoothening of the fringes resulting in a higher angular diameter value. Fourier transforms which reduce discrete noise frequencies do not distort the fringe. Fourier transform method seems to be effective in S/N improvement, as well as improved model fit particularly in the fainter...

  4. Characterization and correction of the false-discovery rates in resting state connectivity using functional near-infrared spectroscopy

    Science.gov (United States)

    Santosa, Hendrik; Aarabi, Ardalan; Perlman, Susan B.; Huppert, Theodore J.

    2017-05-01

    Functional near-infrared spectroscopy (fNIRS) is a noninvasive neuroimaging technique that uses low levels of red to near-infrared light to measure changes in cerebral blood oxygenation. Spontaneous (resting state) functional connectivity (sFC) has become a critical tool for cognitive neuroscience for understanding task-independent neural networks, revealing pertinent details differentiating healthy from disordered brain function, and discovering fluctuations in the synchronization of interacting individuals during hyperscanning paradigms. Two of the main challenges to sFC-NIRS analysis are (i) the slow temporal structure of both systemic physiology and the response of blood vessels, which introduces false spurious correlations, and (ii) motion-related artifacts that result from movement of the fNIRS sensors on the participants' head and can introduce non-normal and heavy-tailed noise structures. In this work, we systematically examine the false-discovery rates of several time- and frequency-domain metrics of functional connectivity for characterizing sFC-NIRS. Specifically, we detail the modifications to the statistical models of these methods needed to avoid high levels of false-discovery related to these two sources of noise in fNIRS. We compare these analysis procedures using both simulated and experimental resting-state fNIRS data. Our proposed robust correlation method has better performance in terms of being more reliable to the noise outliers due to the motion artifacts.

  5. A review on the applications of portable near-infrared spectrometers in the agro-food industry.

    Science.gov (United States)

    dos Santos, Cláudia A Teixeira; Lopo, Miguel; Páscoa, Ricardo N M J; Lopes, João A

    2013-11-01

    Industry has created the need for a cost-effective and nondestructive quality-control analysis system. This requirement has increased interest in near-infrared (NIR) spectroscopy, leading to the development and marketing of handheld devices that enable new applications that can be implemented in situ. Portable NIR spectrometers are powerful instruments offering several advantages for nondestructive, online, or in situ analysis: small size, low cost, robustness, simplicity of analysis, sample user interface, portability, and ergonomic design. Several studies of on-site NIR applications are presented: characterization of internal and external parameters of fruits and vegetables; conservation state and fat content of meat and fish; distinguishing among and quality evaluation of beverages and dairy products; protein content of cereals; evaluation of grape ripeness in vineyards; and soil analysis. Chemometrics is an essential part of NIR spectroscopy manipulation because wavelength-dependent scattering effects, instrumental noise, ambient effects, and other sources of variability may complicate the spectra. As a consequence, it is difficult to assign specific absorption bands to specific functional groups. To achieve useful and meaningful results, multivariate statistical techniques (essentially involving regression techniques coupled with spectral preprocessing) are therefore required to extract the information hidden in the spectra. This work reviews the evolution of the use of portable near-infrared spectrometers in the agro-food industry.

  6. Optical and Near-Infrared Spectroscopy of the L Subdwarf SDSS J125637.13-022452.4

    CERN Document Server

    Burgasser, Adam J; Helling, Christiane; Sanderson, Robyn E; Bochanski, John J; Hauschildt, Peter H

    2009-01-01

    Red optical and near-infrared spectroscopy are presented for SDSS J125637.13-022452.4, one of only four L subdwarfs reported to date. These data confirm the low-temperature, metal-poor nature of this source, as indicated by prominent metal-hydride bands, alkali lines, and collision-induced H2 absorption. The optical and near-infrared spectra of SDSS J1256-0224 are similar to those of the sdL4 2MASS J16262034+3925190, and we derive a classification of sdL3.5 based on the preliminary scheme of Burgasser, Cruz, & Kirkpatrick. The kinematics of SDSS J1256-0224 are consistent with membership in the Galactic inner halo, with estimated $UVW$ space velocities indicating a slightly prograde, eccentric and inclined Galactic orbit (3.5 <~ R <~ 11 kpc; |Zmax| = 7.5 kpc). Comparison to synthetic spectra computed with the Phoenix code, including the recent implementation of kinetic condensate formation (Drift-Phoenix), indicate Teff ~ 2100-2500 K and [M/H] ~ -1.5 to -1.0 for logg ~ 5.0-5.5 (cgs), although there a...

  7. Combined autofluorescence and Raman spectroscopy method for skin tumor detection in visible and near infrared regions

    Science.gov (United States)

    Zakharov, V. P.; Bratchenko, I. A.; Artemyev, D. N.; Myakinin, O. O.; Khristoforova, Y. A.; Kozlov, S. V.; Moryatov, A. A.

    2015-07-01

    The combined application of Raman and autofluorescence spectroscopy in visible and near infrared regions for the analysis of malignant neoplasms of human skin was demonstrated. Ex vivo experiments were performed for 130 skin tissue samples: 28 malignant melanomas, 19 basal cell carcinomas, 15 benign tumors, 9 nevi and 59 normal tissues. Proposed method of Raman spectra analysis allows for malignant melanoma differentiating from other skin tissues with accuracy of 84% (sensitivity of 97%, specificity of 72%). Autofluorescence analysis in near infrared and visible regions helped us to increase the diagnostic accuracy by 5-10%. Registration of autofluorescence in near infrared region is realized in one optical unit with Raman spectroscopy. Thus, the proposed method of combined skin tissues study makes possible simultaneous large skin area study with autofluorescence spectra analysis and precise neoplasm type determination with Raman spectroscopy.

  8. High responsivity near-infrared photodetectors in evaporated Ge-on-Si

    Science.gov (United States)

    Sorianello, V.; De Iacovo, A.; Colace, L.; Fabbri, A.; Tortora, L.; Buffagni, E.; Assanto, G.

    2012-08-01

    Germanium is considered the most suitable semiconductor for monolithic integration of near-infrared detectors on silicon photonic chips. Here we report on Ge-on-Si near-infrared photodetectors fabricated by thermal evaporation, demonstrating the use of phosphorus spin-on-dopant to compensate the acceptor states introduced by dislocations. The detectors exhibit 1.55 μm responsivities as high as 0.1 A/W, more than two orders of magnitude larger than in undoped devices and comparing well with state-of-the-art p-i-n photodiodes. This approach enables simple and low-cost monolithic integration of near-infrared sensors with silicon photonics.

  9. Determination of Oxygen Saturation and Photoplethysmogram from Near Infrared Scattering Images

    CERN Document Server

    Ri, Yong-U; Sin, Kye-Ryong

    2016-01-01

    The near infrared scattering images of human muscle include some information on bloodstream and hemoglobin concentration according to skin depth and time. This paper addressed a method of determining oxygen saturation and photoplethysmogram from the near infrared (NIR) scattering images of muscle. Depending on the modified Beer-Lambert Law and the diffuse scattering model of muscular tissue, we determined an extinction coefficient matrix of hemoglobin from the near infrared scattering images and analyzed distribution of oxygen saturation of muscle with a depth from the extinction coefficient matrix. And we determined a dynamic attenuation variation curve with respect to fragmentary image frames sensitive to bloodstream from scattering image frames of muscle with time and then obtained the photoplethysmogram and heart rate by Fourier transformation and inverse transformation. This method based on the NIR scattering images can be applied in measurement of an average oxygen saturation and photoplethysmogram even...

  10. Near-infrared reflectance analysis by Gauss-Jordan linear algebra

    Energy Technology Data Exchange (ETDEWEB)

    Honigs, D.E.; Freelin, J.M.; Hieftje, G.M.; Hirschfeld, T.B.

    1983-11-01

    Near-infrared reflectance analysis is an analytical technique that uses the near-infrared diffuse reflectance of a sample at several discrete wavelengths to predict the concentration of one or more of the chemical species in that sample. However, because near-infrared bands from solid samples are both abundant and broad, the reflectance at a given wavelength usually contains contributions from several sample components, requiring extensive calculations on overlapped bands. In the present study, these calculations have been performed using an approach similar to that employed in multi-component spectrophotometry, but with Gauss-Jordan linear algebra serving as the computational vehicle. Using this approach, correlations for percent protein in wheat flour and percent benzene in hydrocarbons have been obtained and are evaluated. The advantages of a linear-algebra approach over the common one employing stepwise regression are explored.

  11. Optical and near-infrared spectrophotometric properties of Long Period Variables and other luminous red stars

    CERN Document Server

    Alvarez, R; Plez, B; Wood, P R

    2000-01-01

    Based on a new and large sample of optical and near-infrared spectra obtained at the Mount Stromlo and Siding Spring Observatories (Lancon & Wood 1998; Lancon & Wood, in preparation), spectrophotometric properties of cool oxygen- and carbon-rich Long Period Variables and supergiants are presented. Temperatures of oxygen-rich stars are assigned by comparison with synthetic spectra computed from up-to-date oxygen-rich model atmosphere grids. The existence of reliable optical and near-infrared temperature indicators is investigated. A narrow relation between the bolometric correction BC(I) and the broad-band colour I-J is obtained for oxygen-rich cool stars. The ability of specific near-infrared indices to separate luminosity classes, atmospheric chemistry or variability subtypes is discussed. Some comments are also given on extinction effects, water band strengths in Long Period Variables and the evaluation of 12CO/13CO ratio in red giants.

  12. Quantitative analysis of peanut oil content in ternary blended edible oil using near infrared spectroscopy

    Science.gov (United States)

    Chen, Huacai; Liu, Fuli; Wang, Zhilan; Jin, Shangzhong

    2008-03-01

    Calibration models of quantitative analysis of peanut oil content in ternary blended edible oil by near infrared spectroscopy were built using partial least square (PLS) regression. A total of 92 samples blended with three kinds of pure oil in different proportion (V/V) were prepared. Near infrared diffuse reflectance spectra of the samples were collected over 4 000 cm -1-10 000 cm -1 spectral region with a FT-NIR spectrometer. A calibration model of prediction to the peanut oil content was established with PLS using the original spectra and validated with leave-one-out cross validation method. The correlation coefficient and the RMSEC of the model were 0.9926 and 2.91%, respectively. The result showed that near infrared spectroscopy could be an ideal tool for fast determination to the peanut oil content in blended edible oil.

  13. Near infrared single photon avalanche detector with negative feedback and self quenching

    Science.gov (United States)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2009-08-01

    We present the design and development of a negative feedback devices using the internal discrete amplifier approach used for the development of a single photon avalanche photodetector in the near infrared wavelength region. This new family of photodetectors with negative feedback, requiring no quenching mechanism using Internal Discrete Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions, operates in the non-gated mode under a constant bias voltage. The demonstrated device performance far exceeds any available solid state Photodetectors in the near infrared wavelength range. The measured devices have Gain > 2×105, Excess noise factor Lidar, free space optical communication, 3D imaging, industrial and scientific instrumentation, night vision, quantum cryptography, and other military, defence and aerospace applications.

  14. Dissolved Gas-in-Oil Analysis in Transformers Based on Near-Infrared Photoacoustic Spectroscopy

    Science.gov (United States)

    Mao, Xuefeng; Zhou, Xinlei; Zhai, Liang; Yu, Qingxu

    2015-06-01

    This paper investigates an application of near-infrared photoacoustic spectroscopy (PAS) to analyze the dissolved gas-in-oil of a transformer. A near-infrared tunable fiber laser-based PAS system has been developed. Using this system, the gas detection limits (signal-to-noise ratio = 1) of 4 ppb at 1531.59 nm for , 39 ppm at 1565.98 nm for CO, and 34 ppm at 1572.34 are reached. In addition, the fault gas () is produced by a transformer spatial discharge simulation system, and the productivity of the gas is measured quantitatively. The experiment demonstrates the near-infrared PAS system is able to be applied to the dissolved gas analysis of a transformer.

  15. Near-infrared observations of the Be/X-ray binary pulsar A0535+262

    Institute of Scientific and Technical Information of China (English)

    Sachindra Naik; Blesson Mathew; D. P. K. Banerjee; N. M. Ashok; Rajeev R. Jaiswal

    2012-01-01

    We present the results obtained from extensive near-infrared (IR) spectro-scopic and photometric observations of the Be/X-ray binary A0535+262/HDE 245770 at different phases of its ~ 111 d orbital period.This observation campaign is part of the monitoring program of selective Be/X-ray binary systems aimed at understanding X-ray and near-IR properties at different orbital phases,especially during the periastron passage of the neutron star.The near-IR observations presented here were carried out using the 1.2 m telescope at the Mt.Abu IR Observatory.Though the source was relatively faint for spectroscopic observations with the 1.2 m telescope,we monitored the source closely during the 2011 February-March giant X-ray outburst to primarily investigate whether any drastic changes in the near-IR JHK spectra took place at the periastron passage.Changes of such a striking nature were expected to be detectable in our spectra.Photometric observations of the Be star show a gradual and systematic fading in the JHK light curves since the onset of the X-ray outburst,which could suggest a mild evacuation/truncation of the circumstellar disk of the Be companion.Near-IR spectroscopy of the object shows that the JHK spectra are dominated by the emission lines of hydrogen Brackett and Paschen series and HeI lines at 1.0830,1.7002 and 2.0585 μm.The presence of all the hydrogen emission lines in the JHK spectra,along with the absence of any significant change in the continuum of the Be companion during X-ray quiescent and X-ray outburst phases,suggests that the near- IR line emitting regions of the disk are not significantly affected during the X-ray outburst.

  16. Intraoperative Near-Infrared Fluorescence Imaging using indocyanine green in colorectal carcinomatosis surgery: Proof of concept.

    Science.gov (United States)

    Barabino, G; Klein, J P; Porcheron, J; Grichine, A; Coll, J-L; Cottier, M

    2016-12-01

    This study assesses the value of using Intraoperative Near Infrared Fluorescence Imaging and Indocyanine green to detect colorectal carcinomatosis during oncological surgery. In colorectal carcinomatosis cancer, two of the most important prognostic factors are completeness of staging and completeness of cytoreductive surgery. Presently, intraoperative assessment of tumoral margins relies on palpation and visual inspection. The recent introduction of Near Infrared fluorescence image guidance provides new opportunities for surgical roles, particularly in cancer surgery. The study was a non-randomized, monocentric, pilot "ex vivo" blinded clinical trial validated by the ethical committee of University Hospital of Saint Etienne. Ten patients with colorectal carcinomatosis cancer scheduled for cytoreductive surgery were included. Patients received 0.25 mg/kg of Indocyanine green intravenously 24 h before surgery. A Near Infrared camera was used to detect "ex-vivo" fluorescent lesions. There was no surgical mortality. Each analysis was done blindly. In a total of 88 lesions analyzed, 58 were classified by a pathologist as cancerous and 30 as non-cancerous. Among the 58 cancerous lesions, 42 were correctly classified by the Intraoperative Near-Infrared camera (sensitivity of 72.4%). Among the 30 non-cancerous lesions, 18 were correctly classified by the Intraoperative Near-Infrared camera (specificity of 60.0%). Near Infrared fluorescence imaging is a promising technique for intraoperative tumor identification. It could help the surgeon to determine resection margins and reduce the risk of locoregional recurrence. Copyright © 2016 Elsevier Ltd, BASO ~ the Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  17. Near-infrared absorption spectroscopy of interstellar hydrocarbon grains

    Science.gov (United States)

    Pendleton, Y. J.; Sandford, S. A.; Allamandola, L. J.; Tielens, A. G. G. M.; Sellgren, K.

    1994-01-01

    We present new 3600 - 2700/cm (2.8 - 3.7 micrometer) spectra of objects whose extinction is dominated by dust in the diffuse interstellar medium. The observations presented here augment an ongoing study of the organic component of the diffuse interstellar medium. These spectra contain a broad feature centered near 3300/cm (3.0 micrometers) and/or a feature with a more complex profile near 2950/cm (3.4 micrometers), the latter of which is attributed to saturated aliphatic hydrocarbons in interstellar grains and is the primary interest of this paper. As in our earlier work, the similarity of the absorption bands near 2950/cm (3.4 micrometers) along different lines of sight and the correlation of these features with interstellar extinction reveal that the carrier of this band lies in the dust in the diffuse interstellar medium (DISM). At least 2.5% of the cosmic carbon in the local interstellar medium and 4% toward the Galactic center is tied up in the carrier of the 2950/cm (3.4 micrometer) band. The spectral structure of the diffuse dust hydrocarbon C-H stretch absorption features is reasonably similar to UV photolyzed laboratory ice residues and is quite similar to the carbonaceous component of the Murchison meteorite. The similarity between the DISM and the meteoritic spectrum suggests that some of the interstellar material originally incorporated into the solar nebula may have survived relatively untouched in primitive solar system bodies. Comparisons of the DISM spectrum to hydrogenated amorphous carbon and quenched carbonaceous composite are also presented. The A(sub V)/tau ratio for the 2950/cm (3.4 micrometer) feature is lower toward the Galactic center than toward sources in the local solar neighborhood (approximately 150 for the Galactic center sources vs. approximately 250 for the local ISM sources). A similar trend has been observed previously for silicates in the diffuse medium by Roche & Aitken, suggesting that (1) the silicate and carbonaceous

  18. Near-infrared pulsed light to guide prostate biopsy

    Science.gov (United States)

    Boutet, J.; Debourdeau, M.; Laidevant, A.; Hervé, L.; Allié, C.; Vray, D.; Dinten, J.-M.

    2011-03-01

    The protocol for prostate cancer diagnosis, currently based on ultrasound guided biopsy, is limited by a lack of relevance. To improve this protocol, a new approach was proposed combining optical and ultrasound measurements to guide biopsy specifically to the tumors. Adding an optical measurement modality into an already existing ultrasound probe is challenging as the overall size of the system should not exceed a given dimension so as to fit the operative environment. Moreover, examination should not take more than 15 min to avoid any complication. A combined ultrasound and optical endorectal probe was designed to comply with the constraints of the sterilization protocols, the examination duration and required compactness. Therefore a totally innovative pulsed laser source has been designed to meet compactness requirements while providing accurate time-resolved measurements. A dedicated multi-channel photon counting system was optimized to decrease the examination duration. A fast reconstruction method based on the analysis of the intensity and time of flight of the detected photons has been associated to provide 3D localization of fluorescent dots almost immediately after acquisition. The bi-modal probe was capable of withstanding the sterilization procedures. The performance of the compact laser source has been shown at the same level as that of a standard laboratory Titane:Sapphire laser. The dedicated photon counting solution was capable of acquiring optical data in less than one minute. To evaluate the overall performance of the system in dealing with a realistic background signal, measurements and reconstructions were conducted on prostate mimicking phantom and in vivo.

  19. Localization of Vibrating Noise Sources in Nuclear Reactor Cores

    Energy Technology Data Exchange (ETDEWEB)

    Hultqvist, Pontus

    2004-09-01

    In this thesis the possibility of locating vibrating noise sources in a nuclear reactor core from the neutron noise has been investigated using different localization methods. The influence of the vibrating noise source has been considered to be a small perturbation of the neutron flux inside the reactor. Linear perturbation theory has been used to construct the theoretical framework upon which the localization methods are based. Two different cases have been considered: one where a one-dimensional one-group model has been used and another where a two-dimensional two-energy group noise simulator has been used. In the first case only one localization method is able to determine the position with good accuracy. This localization method is based on finding roots of an equation and is sensitive to other perturbations of the neutron flux. It will therefore work better with the assistance of approximative methods that reconstruct the noise source to determine if the results are reliable or not. In the two-dimensional case the results are more promising. There are several different localization techniques that reproduce both the vibrating noise source position and the direction of vibration with enough precision. The approximate methods that reconstruct the noise source are substantially better and are able to support the root finding method in a more constructive way. By combining the methods, the results will be more reliable.

  20. Crude Oil Model Emulsion Characterised by means of Near Infrared Spectroscopy and Multivariate Techniques

    DEFF Research Database (Denmark)

    Kallevik, H.; Hansen, Susanne Brunsgaard; Sæther, Ø.

    2000-01-01

    Water-in-oil emulsions are investigated by means of multivariate analysis of near infrared (NIR) spectroscopic profiles in the range 1100 - 2250 nm. The oil phase is a paraffin-diluted crude oil from the Norwegian Continental Shelf. The influence of water absorption and light scattering of the wa......Water-in-oil emulsions are investigated by means of multivariate analysis of near infrared (NIR) spectroscopic profiles in the range 1100 - 2250 nm. The oil phase is a paraffin-diluted crude oil from the Norwegian Continental Shelf. The influence of water absorption and light scattering...