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Sample records for annealed zircon near-infrared

  1. Oxidation state of uranium in metamict and annealed zircon: near-infrared spectroscopic quantitative analysis

    International Nuclear Information System (INIS)

    Radiation and thermally induced changes in the oxidation state of uranium in metamict zircon have been systematically analysed, for the first time, using polarized near-infrared spectroscopy. The results showed that in damaged zircon U ions in crystalline domains exhibited relatively sharp, anisotropic signals from tetravalent and pentavalent U ions in crystalline domains (Ucrystal4+ and Ucrystal5+). The linewidths and peak positions of the 4834 cm-1 band (Ucrystal4+, E || c) and the 6668 cm-1 band (Ucrystal5+, E perp. c) are a non-linear function of the self-radiation dose. They reach nearly constant values at doses greater than ∼ 3.5 x 1018 α-events g-1. Quantitative analysis of Ucrystal4+ and Ucrystal5+ signals revealed that the intensity ratio (Ucrystal4+ /Ucrystal5+) exhibited a nearly linear increase as a function of dose and decreased on heating. This suggests that radiation leads to an alteration of the oxidation states of U and the tetravalent state is more preferable in radiation-damaged zircons. U ions associated with amorphous materials (Uamorphous) gave rise to broad and isotropic signals and they were mainly in the tetravalent state (Uamorphous4+), although small amounts of pentavalent U ions (Uamorphous5+) may exist. The dose dependence of the intensity ratio of Uamorphous/Utotal did not follow that of the reported fraction of the amorphous domain, but gave clearly lower values. This implies the potential preferential occurrence of U ions or possible U enrichment in the crystalline regions. Annealing intermediately and highly damaged zircon had different impacts on the oxidation state of U. An intermediately damaged zircon (with a dose of ∼ 5.2 x 1018 α-events g-1), annealed at high temperatures between 500 and 1800 K, showed a systematic increase in the signals of Ucrystal4+ and Ucrystal5+ above 700 K while Ucrystal4+ bands disappeared at temperatures above 1600 K. In contrast, a highly damaged zircon (with a dose of ∼ 15.9 x 1018

  2. Oxidation state of uranium in metamict and annealed zircon: near-infrared spectroscopic quantitative analysis

    CERN Document Server

    Zhang Ming; Ewing, R C

    2003-01-01

    Radiation and thermally induced changes in the oxidation state of uranium in metamict zircon have been systematically analysed, for the first time, using polarized near-infrared spectroscopy. The results showed that in damaged zircon U ions in crystalline domains exhibited relatively sharp, anisotropic signals from tetravalent and pentavalent U ions in crystalline domains (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l sup 5 sup +). The linewidths and peak positions of the 4834 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + , E || c) and the 6668 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 5 sup + , E perp. c) are a non-linear function of the self-radiation dose. They reach nearly constant values at doses greater than approx 3.5 x 10 sup 1 sup 8 alpha-events g sup - sup 1. Quantitative analysis of U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l...

  3. Compensating the Degradation of Near-Infrared Absorption of Black Silicon Caused by Thermal Annealing.

    Science.gov (United States)

    Wang, Yanchao; Gao, Jinsong; Yang, Haigui; Wang, Xiaoyi; Shen, Zhenfeng

    2016-12-01

    We propose the use of thin Ag film deposition to remedy the degradation of near-infrared (NIR) absorption of black Si caused by high-temperature thermal annealing. A large amount of random and irregular Ag nanoparticles are formed on the microstructural surface of black Si after Ag film deposition, which compensates the degradation of NIR absorption of black Si caused by thermal annealing. The formation of Ag nanoparticles and their contributions to NIR absorption of black Si are discussed in detail. PMID:26831694

  4. Intrinsic disorders and annealing metamict zircon as wave-guides

    International Nuclear Information System (INIS)

    The study of intrinsic disorders in zircon showed that at certain temperature during an annealing process, both Schottky and interstitial disorders would dominate the zircon structure. This time would be the best time to implant relative ions by diffusion, or directly to use an accelerator to implant these ions, then anneal the metamict zircon to tailor the characteristics of the zircon as wave-guides

  5. Extrapolation of zircon fission-track annealing models

    International Nuclear Information System (INIS)

    One of the purposes of this study is to give further constraints on the temperature range of the zircon partial annealing zone over a geological time scale using data from borehole zircon samples, which have experienced stable temperatures for ∼1 Ma. In this way, the extrapolation problem is explicitly addressed by fitting the zircon annealing models with geological timescale data. Several empirical model formulations have been proposed to perform these calibrations and have been compared in this work. The basic form proposed for annealing models is the Arrhenius-type model. There are other annealing models, that are based on the same general formulation. These empirical model equations have been preferred due to the great number of phenomena from track formation to chemical etching that are not well understood. However, there are two other models, which try to establish a direct correlation between their parameters and the related phenomena. To compare the response of the different annealing models, thermal indexes, such as closure temperature, total annealing temperature and the partial annealing zone, have been calculated and compared with field evidence. After comparing the different models, it was concluded that the fanning curvilinear models yield the best agreement between predicted index temperatures and field evidence. - Highlights: ► Geological data were used along with lab data for improving model extrapolation. ► Index temperatures were simulated for testing model extrapolation. ► Curvilinear Arrhenius models produced better geological temperature predictions

  6. Atomic retention and near infrared photoluminescence from PbSe nanocrystals fabricated by sequential ion implantation and electron beam annealing

    International Nuclear Information System (INIS)

    Nanocrystals of PbSe have been fabricated in a silicon dioxide matrix by sequential low energy ion implantation followed by an electron beam annealing step. Transmission electron microscopy reveals PbSe nanocrystals with typical sizes between 3 and 10 nm in the sub-surface region. Rutherford Backscattering Spectrometry has been used to study the total atomic retention, as a function of implanted atoms, following annealing. Photoluminescence was observed in various samples, at 4 K, as a broad peak between 1.4 and 2.0 μm, with observation of a dependence of the peak wavelength on annealing temperature. Room temperature photoluminescence was observed for samples with a high retention of implanted atoms, demonstrating the importance of nanocrystal density for achieving ambient temperature emission in these systems

  7. Annealing of natural metamict zircons: II high degree of radiation damage

    CERN Document Server

    Colombo, M

    1998-01-01

    In situ time-dependent high-temperature X-ray powder diffraction was used to study the amorphous to crystalline transition in natural zircons which are characterized by a high degree of radiation damage. It was possible to distinguish two stages of the annealing process: (i) the recovery of the heavily disturbed but still crystalline domains and (ii) the recrystallization of the amorphous regions. The first stage is very fast under the chosen experimental conditions and, at least apparently, is not thermally activated. The second stage is a diffusion-controlled process, whose products (zircon or zircon and zirconia phases) are strongly correlated to the annealing temperature.

  8. Effect of α-damage on fission-track annealing in zircon

    Science.gov (United States)

    Kasuya, Masao; Naeser, Charles W.

    1988-01-01

    The thermal stability of confined fission-track lengths in four zircon samples having different spontaneous track densities (i.e., different amounts of ??-damage) has been studied by one-hour isochronal annealing experiments. The thermal stability of spontaneous track lengths is independent of initial spontaneous track density. The thermal stability of induced track lengths in pre-annealed zircon, however, is significantly higher than that of spontaneous track lengths. The results indicate that the presence of ??-damage lowers the thermal stability of fission-tracks in zircon.

  9. Annealing of natural metamict zircons. I low degree of radiation damage

    CERN Document Server

    Colombo, M

    1998-01-01

    In-situ time dependent high temperature X-ray powder diffraction was used to investigate the ordering process occurring during annealing of natural zircons with a low degree of radiation damage. It was possible to distinguish two stages of this process. Firstly, the diffusion of defects induced by alpha-particles, this stage contributes only to a certain degree of relaxation in the unit cell. In the second stage there is some degree of recrystallization. A hkl-dependence in the variation of the integrated intensity is observed and the increase in the volume of crystalline zircon is therefore related to a process of migration of dislocations.

  10. Effect of microwave annealing temperatures on lead zirconate titanate thin films

    International Nuclear Information System (INIS)

    Lead zirconate titanate (Pb1.1(Zr0.52Ti0.48)O3) thin films of thickness 260 nm on Pt/Ti/SiO2/Si substrates were densified by 2.45 GHz microwave annealing. The PZT thin films were annealed at various annealing temperatures from 400 to 700 deg. C for 30 min. X-ray diffraction showed that the pyrochlore phase was transformed to the perovskite phase at 450 deg. C and the film was fully crystallized. The secondary (again pyrochlore) phase was observed in the PZT thin films, which were annealed above 550 deg. C. The surface morphologies were changed above 550 deg. C of the PZT thin films due to the secondary phase. Higher dielectric constant (εr) and lower dielectric loss coercive field (Ec) were achieved for the 450 deg. C film than for the other annealed films

  11. Annealing of α-decay damage in zircon: a Raman spectroscopic study

    International Nuclear Information System (INIS)

    Recrystallization and structural recovery in α-decay damage in zircon samples have been studied using Raman spectroscopy. Fifteen zircon samples with different degrees of radiation damage have been thermally annealed between 600 K and 1800 K for up to 28 days and 8 hours. The experimental results from this study reveal that recrystallization in the damaged zircon samples is a multi-stage process that depends on the degree of initial damage of the samples. In partially damaged samples the lattice recovery of damaged crystalline ZrSiO4 takes place at temperatures as low as about 700 K, as shown by a remarkable band-sharpening and a significant increase in the frequencies of ν1 and ν3 Si-O stretching vibrations together with the external band near 357 cm-1 with increasing temperature. A dramatic increase of Raman scattering intensity of ZrSiO4 occurs in partially damaged samples near 1000 K due to a recrystallization process involving epitaxial growth. Heavily damaged samples tend to decompose into ZrO2 and SiO2 at high temperatures. Tetragonal ZrO2 has been observed under annealing between 1125 K and about 1600 K in heavily damaged samples while monoclinic ZrO2 appears above 1600 K. Weak signals from ZrSiO4 were detected at 1125 K in highly metamict zircon although the main recrystallization appears to occur near 1500 K accompanied by a decrease of the volumes of ZrO2 as well as SiO2. This suggests that this recrystallization is associated with the reaction of ZrO2 with SiO2 to form ZrSiO4. A possible intermediate phase has been observed, for the first time, by Raman spectroscopy in damaged zircons annealed at temperatures between 800 K and 1400 K. This phase is characterized by strong, broad Raman signals near 670, 798 and 1175 cm-1. Prolonged isothermal annealing at 1050 K results in a decrease of these characteristic bands and eventually the disappearance of this intermediate phase. (author)

  12. Near infrared laser annealing of CdTe and in-situ measurement of the evolution of structural and optical properties

    Science.gov (United States)

    Simonds, Brian J.; Misra, Sudhajit; Paudel, Naba; Vandewal, Koen; Salleo, Alberto; Ferekides, Christos; Scarpulla, Michael A.

    2016-04-01

    The high performance of polycrystalline CdTe thin film solar cells is enabled by annealing in the presence of Cl. This process is typically carried out for tens of minutes resulting in reduction of defect states within the bandgap among other beneficial effects. In this work, we investigate laser annealing as a means of rapidly annealing CdTe using a continuous wave sub-bandgap 1064 nm laser. The partial transmission of the beam allows us to monitor the annealing process in-situ and in real time. We find that optoelectronic and structural changes occur through two distinct kinetic processes resulting in the removal of deep defects and twinned regions, respectively. A multilayer optical model including surface roughness is used to interpret both the in-situ transmission as well as ex-situ reflectivity measurements. These experiments demonstrate beneficial material changes resulting from sub-bandgap laser-driven CdCl2 treatment of CdTe in minutes, which is an important step towards accelerating the processing of the CdTe absorber layer.

  13. Orientation of rapid thermally annealed lead zirconate titanate thin films on (111) Pt substrate

    International Nuclear Information System (INIS)

    The nucleation, growth and orientation of lead zirconate titanate thin films prepared from organometallic precursor solutions by spin coating on (111) oriented platinum substrates and crystallized by rapid thermal annealing was investigated. The effects of pyrolysis temperature, post-pyrolysis thermal treatments, excess lead addition, and Nb dopant substitution are reported. The use of post pyrolysis oxygen anneals at temperatures in the regime of 350-450 deg C was found to strongly effect the kinetics of subsequent amorphous-pyrochlore perovskite crystallization by rapid thermal annealing. It has also allowed films of reproducible microstructure and textures (both (100) and (111)) to be prepared by rapid thermal annealing. It is suggested that such anneals and pyrolysis temperature affect the oxygen concentration/average Pb valence in the amorphous films prior to annealing. The changes in Pb valence state then affect the stability of the transient pyrochlore phase and thus the kinetics of perovskite crystallization. Nb dopant was also found to influence the crystallization kinetics. 28 refs., 18 figs

  14. 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.

  15. Near infrared testbed sensor

    Science.gov (United States)

    Sanderson, R. B.; McCalmont, J. F.; Montgomery, J. B.; Johnson, R. S.; McDermott, D. J.

    2007-04-01

    A new tactical airborne multicolor missile warning testbed was developed and fielded as part of an Air Force Research Laboratory (AFRL) initiative focusing on clutter and missile signature measurements for algorithm development. Multicolor discrimination is one of the most effective ways of improving the performance of infrared missile warning sensors, particularly for heavy clutter situations. Its utility has been demonstrated in multiple fielded sensors. Traditionally, multicolor discrimination has been performed in the mid-infrared, 3-5 μm band, where the molecular emission of CO and CO2 characteristic of a combustion process is readily distinguished from the continuum of a black body radiator. Current infrared warning sensor development is focused on near infrared (NIR) staring mosaic detector arrays that provide similar spectral discrimination in different bands to provide a cost effective and mechanically simpler system. This, in turn, has required that multicolor clutter data be collected for both analysis and algorithm development. The developed sensor test bed is a multi-camera system 1004x1004 FPA coupled with optimized filters integrated with the optics. The collection portion includes a ruggedized field-programmable gate array processor coupled with with an integrated controller/tracker and fast disk array capable of real-time processing and collection of up to 60 full frames per second. This configuration allowed the collection and real-time processing of temporally correlated, radiometrically calibrated data in multiple spectral bands that was then compared to background and target imagery taken previously

  16. Effects of rapid thermal annealing on nucleation, growth, and properties of lead zirconate titanate films.

    Science.gov (United States)

    Lu, Jian; Zhang, Yi; Ikehara, Tsuyoshi; Mihara, Takashi; Maeda, Ryutaro

    2007-12-01

    The nucleation and growth behavior of solgel-derived lead zirconate titanate (PZT) films was investigated at different rapid thermal annealing (RTA) processes. The effects of RTA on PZT film surface morphology, crystal orientation, residual stress, and properties were also studied and are discussed. PZT nucleation and growth behavior were found to be more sensitive to heating rate than to hold time during RTA. Higher heating rates were preferred for uniform PZT nucleation and grain growth, which resulted in dense microstructures, smooth surfaces, and better film ferroelectric properties. Lower heating rates led to strong PZT (100) orientation, better film piezoelectric properties, and low residual stress, but at the risk of film cracks caused by arbitrarily distributed large crystallites with diameters of approximately 300 nm among crystallites with diameters of approximately 30 nm. Furthermore, the residual stress of the PZT film was found to be effectively reduced by extending the hold time. PMID:18276553

  17. XAS and XRD study of annealed 238Pu- and 239Pu-substituted zircons (Zr0.92Pu0.08SiO4)

    International Nuclear Information System (INIS)

    An annealing study has been completed on two compositionally identical Pu-substituted zircons (Zr0.92Pu0.08SiO4) prepared 18 yr ago with different 238Pu/239Pu isotopic ratios. The activity and accumulated dose for each material varies greatly due to the very different half-lives of 238Pu (87.7 yr) and 239Pu (24 100 yr). The predominantly 238Pu-substituted zircon is in a highly amorphous state after accumulating a dose of 2.8x1019 α-decays/g, which is a factor of two higher than the dose previously determined necessary to amorphize this material. The 239Pu-substituted zircon has remained highly crystalline after an accumulated dose of 1.2x1017 α-decays/g. The Pu in both samples is trivalent due to sintering under reducing conditions. The short-range and long-range structures of each sample have been characterized by detailed X-ray absorption spectroscopy and X-ray diffraction (XRD) methods. The oxidation of Pu3+ to Pu4+ in the crystalline 239Pu-substituted zircon during annealing in air resulted in a decrease in lattice distortion due to the decrease in ionic radius of Pu3+ to Pu4+ on the Zr4+ site. A significant amount of PuO2 exsolved from the zircon structure after annealing at 1200 deg. C in air. Detailed characterization of the amorphous 238Pu-substituted zircon demonstrated that while devoid of long-range order it still retained a distorted zircon structure and composition over a length scale of 0.5 nm. The recrystallization of the amorphous 238Pu-substituted zircon could be achieved directly at temperatures as low as 1200 deg. C when annealed for 12 h in air; however, annealing at 1000 deg. C resulted in decomposition into constituent oxides

  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. The TNG Near Infrared Camera Spectrometer

    OpenAIRE

    Baffa, C.; Comoretto, G.; Gennari, S.; F. Lisi; Oliva, E; Biliotti, V.; Checcucci, A.; Gavrioussev, V.; Giani, E; Ghinassi, F.; Hunt, L. K.; Maiolino, R.; Mannuci, F.; Marcucci, G.; Sozzi, M.

    2001-01-01

    NICS (acronym for Near Infrared Camera Spectrometer) is the near-infrared cooled camera-spectrometer that has been developed by the Arcetri Infrared Group at the Arcetri Astrophysical Observatory, in collaboration with the CAISMI-CNR for the TNG (the Italian National Telescope Galileo at La Palma, Canary Islands, Spain). As NICS is in its scientific commissioning phase, we report its observing capabilities in the near-infrared bands at the TNG, along with the measured performance and the limi...

  20. Near infrared spectroscopy and exercise

    International Nuclear Information System (INIS)

    Near infrared spectroscopy (NIRS) provides a non-invasive method for the continuous monitoring of changes in tissue oxygenation and blood volume during aerobic exercise. During incremental exercise in adult subjects there was a positive correlation between lactate threshold (measured by blood sampling) and changes in the rate of muscle deoxygenation (measured by NIRS). However, the 7% failure rate for the NIRS test mitigated against the general use of this method. NIRS did not provide a valid method for LT determination in an adolescent population. NIRS was then used to examine whether haemodynamic changes could be a contributing factor to the mechanism underlying the cross-transfer effect. During a one-legged incremental aerobic exercise test the muscle was more deoxygenated in the exercising leg than in the non-exercising leg, consistent with oxygen consumption outstripping blood flow to the exercising limb. However, muscle blood volume increased equally in both legs. This suggests that blood flow may be raised to similar levels in both the legs; although local factors may signal an increase in blood volume, this effect is expressed in both legs. Muscle blood flow and changes in muscle blood volume were then measured directly by NIRS during an incremental one-arm aerobic exercise test. There was no significant difference in either blood volume or blood flow in the two arms at the end of the test. In the non-exercising arm changes in blood flow and blood volume were measured throughout the protocol. At higher exercise intensities, blood volume continued to rise as muscle blood flow plateaued, indicating that blood volume changes become independent of changes in blood flow. Finally, the effect of different training regimes on changes in muscle blood volume was examined. Subjects were assigned to a training group; two-arm training, one-arm training or a control group. Training did not affect blood volume changes during two-arm exercise. However, during one

  1. Low-temperature optical characterization of a near-infrared single-photon emitter in nanodiamonds

    OpenAIRE

    Siyushev, P.; Jacques, V.; Aharonovich, I; Kaiser, F.; Müller, T; Lombez, L.; Atatüre, M.; Castelletto, S.; Prawer, S.; Jelezko, F.; Wrachtrup, J.

    2009-01-01

    In this paper, we study the optical properties of single defects emitting in the near infrared in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line in the near infrared, the radiative lifetime is in the nanos...

  2. Near-infrared thermochromic diazapentalene dyes

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Gang [Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario (Canada); Wang, Zhi Yuan [Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario (Canada); State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-03-22

    A series of 2,5-diazapentalene containing dyes with tunable energy gaps are visible and near-infrared halochromic towards various acids and their protonated counterparts represent a new class of thermochromic materials with the near-infrared absorption being switched on at room temperature and off above 50 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Illuminant estimation and detection using near infrared

    OpenAIRE

    Fredembach, Clement; Süsstrunk, Sabine

    2009-01-01

    Digital camera sensors are sensitive to wavelengths ranging from the ultraviolet (200-400nm) to the near-infrared (700-100nm) bands. This range is, however, reduced because the aim of photographic cameras is to capture and reproduce the visible spectrum (400-700nm) only. Ultraviolet radiation is filtered out by the optical elements of the camera, while a specifically designed "hot-mirror" is placed in front of the sensor to prevent near-infrared contamination of the visible image. We propose ...

  4. Near-infrared scintillation of liquid argon

    Science.gov (United States)

    Alexander, T.; Escobar, C. O.; Lippincott, W. H.; Rubinov, P.

    2016-03-01

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 μm 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.

  5. 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.

  6. Speeded Near Infrared Spectroscopy (NIRS) Response Detection

    OpenAIRE

    Cui, Xu; Bray, Signe; Reiss, Allan L

    2010-01-01

    The hemodynamic response measured by Near Infrared Spectroscopy (NIRS) is temporally delayed from the onset of the underlying neural activity. As a consequence, NIRS based brain-computer-interfaces (BCIs) and neurofeedback learning systems, may have a latency of several seconds in responding to a change in participants' behavioral or mental states, severely limiting the practical use of such systems. To explore the possibility of reducing this delay, we used a multivariate pattern classificat...

  7. Multiphoton microscopy with near infrared contrast agents

    Science.gov (United States)

    Yazdanfar, Siavash; Joo, Chulmin; Zhan, Chun; Berezin, Mikhail Y.; Akers, Walter J.; Achilefu, Samuel

    2010-05-01

    While multiphoton microscopy (MPM) has been performed with a wide range of excitation wavelengths, fluorescence emission has been limited to the visible spectrum. We introduce a paradigm for MPM of near-infrared (NIR) fluorescent molecular probes via nonlinear excitation at 1550 nm. This all-NIR system expands the range of available MPM fluorophores, virtually eliminates background autofluorescence, and allows for use of fiber-based, turnkey ultrafast lasers developed for telecommunications.

  8. Low temperature optical characterization of near infrared single photon emitter in nanodiamonds

    CERN Document Server

    Siyushev, P; Aharonovich, I; Kaiser, F; Müller, T; Lombez, L; Atatüre, M; Castelletto, S; Prawer, S; Jelezko, F; Wrachtrup, J

    2009-01-01

    In this paper, we study the optical properties of single defects emitting in the near infrared in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line in the near infrared, the radiative lifetime is in the nanosecond range and the emission is perfectly linearly polarized. The spectral stability of the defects is then investigated. An optical resonance linewidth of 4 GHz is measured using resonant excitation on the zero-phonon line. Although Fourier-transform limited emission is not achieved, our results show that it might be possible to use consecutive photons emitted in the near infrared by single defects in diamond nanocrystals to perform two photon interference experiments, which are at the heart of linear quantum computing p...

  9. The physics of near-infrared photography

    International Nuclear Information System (INIS)

    The physics behind the sometimes strange effects and ‘unnatural’ appearance of near-infrared (NIR) photographs is discussed in terms of reflection, absorption and transmission of NIR radiation with the respective objects. Besides discussing how NIR cameras work, several visible and NIR photograph pairs are presented, which include vegetation, natural water, clouds, the sky, and humans. In addition, some physics-oriented experimental NIR images are presented which clearly demonstrate some of the basic physics behind some of these awesome sights. (paper)

  10. 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.

  11. 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.

  12. Multi-channel near infrared spectroradiometer

    International Nuclear Information System (INIS)

    A multichannel spectroradiometer has been developed by Sira Ltd. for the study of rapidly varying events in the near infrared. The instrument is being used in the examination of gun flashes, rocket motor exhaust efflux analysis and ordnance or pyrotechnic flash studies. The spectral range of about 1.4 to 5.2 microns is covered in two bands with the first order dispersion from a pair of ruled blazed gratings being imaged onto a pair of detector arrays. Data may be logged at a rate of 1000 complete spectra per second

  13. 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.

  14. Near-infrared spectroscopy for cocrystal screening

    DEFF Research Database (Denmark)

    Allesø, Morten; Velaga, Sitaram; Alhalaweh, Amjad; Cornett, Claus; Rasmussen, Morten Arendt; Van Der Berg, Franciscus Winfried J; de Diego, Heidi Lopez; Rantanen, Jukka

    2008-01-01

    Near-infrared (NIR) spectroscopy is a well-established technique for solid-state analysis, providing fast, noninvasive measurements. The use of NIR spectroscopy for polymorph screening and the associated advantages have recently been demonstrated. The objective of this work was to evaluate the...... retained in a physical mixture with the guest molecule, while liquid-assisted cogrinding did not induce any changes in the crystal lattice. The good chemical peak selectivity of Raman spectroscopy allowed a straightforward interpretation of sample data by analyzing peak positions and comparing to those of...

  15. Speeded near infrared spectroscopy (NIRS) response detection.

    Science.gov (United States)

    Cui, Xu; Bray, Signe; Reiss, Allan L

    2010-01-01

    The hemodynamic response measured by Near Infrared Spectroscopy (NIRS) is temporally delayed from the onset of the underlying neural activity. As a consequence, NIRS based brain-computer-interfaces (BCIs) and neurofeedback learning systems, may have a latency of several seconds in responding to a change in participants' behavioral or mental states, severely limiting the practical use of such systems. To explore the possibility of reducing this delay, we used a multivariate pattern classification technique (linear support vector machine, SVM) to decode the true behavioral state from the measured neural signal and systematically evaluated the performance of different feature spaces (signal history, history gradient, oxygenated or deoxygenated hemoglobin signal and spatial pattern). We found that the latency to decode a change in behavioral state can be reduced by 50% (from 4.8 s to 2.4 s), which will enhance the feasibility of NIRS for real-time applications. PMID:21085607

  16. Evaluation of a near-infrared photomultiplier

    Science.gov (United States)

    Evans, W. E.

    1978-01-01

    A high performance near infrared sensitive photomultiplier tube was procured and evaluated with emphasis on those characteristics affecting its use over the very large amplitude range of signals encountered by an airborne lidar intended for mapping the distribution of stratospheric aerosols. A cathode quantum efficiency of 4.3 percent at 1.06 micrometer wavelength and a background count of less than 10,000 per second were realized. It is recommended that the tube be stored and operated at a temperature near -20 C, or cooler. Performance was found acceptable for the application in both pulse counting and analog modes, but careful design, probably including dynamic gain control, will be required to effectively utilize both modes on the same lidar shot.

  17. Designed blending for near infrared calibration.

    Science.gov (United States)

    Scheibelhofer, Otto; Grabner, Bianca; Bondi, Robert W; Igne, Benoît; Sacher, Stephan; Khinast, Johannes G

    2015-07-01

    Spectroscopic methods are increasingly used for monitoring pharmaceutical manufacturing unit operations that involve powder handling and processing. With that regard, chemometric models are required to interpret the obtained spectra. There are many ways to prepare artificial powder blend samples used in a chemometric model for predicting the chemical content. Basically, an infinite number of possible concentration levels exist in terms of the individual components. In our study, design of experiments for ternary mixtures was used to establish a suitable number of blend compositions that represents the entire mixture region of interest for a three component blend. Various experimental designs and their effect on the predictive power of a chemometric model for near infrared spectra were investigated. It was determined that a particular choice of experimental design could change the predictive power of a model, even with the same number of calibration experiments. PMID:25980978

  18. Near infrared microcoupler with multilayer isotropic metamaterials

    Science.gov (United States)

    Li, Kun; Tian, Chao; Liu, Shengchun; Zhang, Jintao; Lv, Houjun; Zhu, Xuefeng

    2015-10-01

    This paper reports the design of a microcoupler in the near-infrared region. The proposed structure consists of two alternately arranged complementary media. The complementary media, which consist of double-positive material and double-negative material, also can be made of a pair of single-negative materials. Simulation results show that the proposed structure has an excellent coupling efficiency compared to direct coupling. It has a maximum coupling efficiency closing to 1 at 1550 nm. As the total size of the coupling structure decreases, the passband exhibits a property of gradual blue shift. Therefore, we can design couplers operating in different frequency bands with high coupling efficiency. The influence of the permittivity and the thickness of each material layer on the coupling efficiency are also studied in detail. The proposed microcoupler has potential guidance in the design and development of high-performance coupling structures.

  19. 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...

  20. Near-infrared fluorescence sensor technology

    Science.gov (United States)

    Evans, Lawrence, III; Casay, Guillermo A.; Dai, Dong; Patonay, Gabor

    1995-10-01

    Fluorescence spectroscopy has been used extensively to solve environmental problems (including biological, water quality, separation and etc.). Despite its numerous applications, long wavelength, near- infrared (NIR) fluorescence has been the subject of very few studies. This wavelength region is advantageous, if we wish to minimize the effect of background interference. Lowering the background interference is especially advantageous in environmental monitoring applications where very little or no preseparation is necessary to achieve selective measurements. The applications of NIR absorbing fluorophores which usually have high molar absorptivities and good quantum yields can be especially advantageous when laser diodes are employed as the excitation source. This paper will focus on several general practical analytical applications of NIR fluorescence spectroscopy for solving environmental related analytical problems, including but not limited to: use of NIR fluorophores as labels (in conjunction with immunosensor technology) and the use of NIR chromophores as direct probes (pH, metal ion, etc.). Additionally the use of laser diodes and semiconductor detectors (silicon photodiodes and avalanche photodiodes) as light sources and detectors will be discussed.

  1. Near-infrared fluorophores as biomolecular probes

    Science.gov (United States)

    Patonay, Gabor; Beckford, Garfield; Strekowski, Lucjan; Henary, Maged; Merid, Yonathan

    2010-02-01

    Near-Infrared (NIR) fluorescence has been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including hydrophobicity of protein binding sites, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) has advantages for the spectroscopist due to the inherently lower background interference from the biological matrix and the high molar absorptivities of NIR chromophores. During the studies we report here several NIR dyes were prepared to determine the role of the hydrophobicity of NIR dyes and their charge in binding to amino acids and proteins, e.g., serum albumins. We synthesized NIR dye homologs containing the same chromophore but substituents of varying hydrophobicity. Hydrophobic moieties were represented by alkyl and aryl groups. These NIR dyes of varying hydrophobicity exhibited varying degrees of H-aggregation in aqueous solution indicating that the degree of H-aggregation could be used as an indicator to predict binding characteristics to serum albumins. In order to understand what factors may be important in the binding process, spectral behavior of these varying hydrophobicity dyes were examined in the presence of amino acids. Typical dye structures that exhibit large binding constants to biomolecules were compared in order to optimize applications utilizing non-covalent interactions.

  2. 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...

  3. Near-infrared spectroscopy during peripheral vascular surgery

    DEFF Research Database (Denmark)

    Eiberg, J P; Schroeder, T V; Vogt, K C; Secher, N H

    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...... indicate that near-infrared spectroscopy is appropriate for perioperative monitoring during vascular grafting....

  4. Near-infrared probes: design and applications

    Science.gov (United States)

    Patonay, G.; Strekowski, L.; Raszkiewicz, A.; Kim, J. S.

    2006-02-01

    Near-Infrared (NIR) absorbing chromophores have been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including solvent polarity, hydrophobicity, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) is more advantageous for the bioanalytical chemist due to the inherently lower background interference and the high molar absorptivities. NIR dyes can be used as simple probes to investigate biomolecule properties or just simply to detect the presence of biomolecules. Another typical application is the use of NIR fluorophores as labels. In these applications covalent labeling is the preferred method but it requires NIR dyes with appropriate reactive moieties. Due to the hydrophobic nature of NIR chromophores non-covalent labeling may be a viable alternative. For this purpose novel bis(carbocynines) have been developed in our laboratories. These dyes form intramolecular H-aggregates in polar solvents, even at very low concentrations. Spectral properties of this intramolecular dimer greatly depend on the properties of heterocyclic moieties and the length, the location and/or flexibility of the connecting chain. This form of the dye can be described as a clamshell complex with two interacting hydrophobic carbocyanine moieties. This intramolecular H-aggregate has a low extinction coefficient and fluorescence quantum yield. Upon opening the clamshell that can be facilitated by changing microhydrophobicity (i.e., binding to biomolecules) the H-and D- bands are decreased and the monomeric band is increased, with concomitant increase in fluorescence intensity. The main analytical utility of these bis(carbocyanines) is that the free dye (i.e., not complexed to an analyte) has negligible fluorescence in a typical aqueous buffer environment. Examples of different applications of these bis(carbocyanines) are given including forensic applications.

  5. Dependence of the optimum parameters of femtosecond laser annealing of lead zirconate titanate films on their thickness

    Science.gov (United States)

    Elshin, A. S.; Abdullaev, D. A.; Mishina, E. D.

    2016-06-01

    The optimum parameters of laser annealing (crystallization) induced by repetitive pulses with a pulse duration of 100 fs and a wavelength of 800 nm, which falls in the transparency region of the film and, simultaneously, in the absorption region of the substrate, have been investigated experimentally as a function of the thickness of the ferroelectric film. It has been shown that, with an increase in the thickness of the ferroelectric film by 100 nm (in the range from 300 to 600 nm), the required power density of the laser beam increases, on the average, by 0.1 MW/cm2. The optimum exposure time of the laser beam with the desired power increases nonlinearly with an increase in the thickness of the film.

  6. 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

  7. 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.

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

    International Nuclear Information System (INIS)

    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. Tunable near infrared radiation for sensing of natural gas

    International Nuclear Information System (INIS)

    Near infrared radiation tunable from 3.04 to 3.40 microns for sensing of natural gas is generated through difference frequency mixing of Nd laser and the same pumped dye laser radiations in the recently developed Beta Barium Borate crystal. Exploiting very high laser damage threshold of the crystal, the conversion efficiency at the generated near infrared radiation in the mixing process can be increased to a large extent simply by raising the peak power densities of the input dye and Nd lasers

  10. FIRE near-infrared spectroscopic classifications of SN 2016dag

    Science.gov (United States)

    Morrell, N.; Phillips, M. M.; Contreras, C.; Hsia, E. Y.

    2016-07-01

    We report the spectroscopic classification of SN 2016dag, discovered by the Backyard Observatory Supernova Search (BOSS), using a near-infrared spectrum (range 800-2500 nm) obtained on Jul 14.95 UT with the FoldedPort Infrared Echellette (FIRE) spectrograph on the 6.5-m Magellan Baade Telescope at Las Campanas Observatory.

  11. 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...

  12. Detecting Counterfeit Antimalarial Tablets by Near-Infrared Spectroscopy

    Science.gov (United States)

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discrim...

  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. On...

  14. 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 is...

  15. Near-Infrared Quantum Cutting Long Persistent Luminescence

    Science.gov (United States)

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called “near-infrared quantum cutting long persistent luminescence (NQPL)”, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in 3P0 levels of Pr3+. Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging. PMID:27143282

  16. 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.

  17. TIRCAM2: The TIFR near infrared imaging camera

    Science.gov (United States)

    Naik, M. B.; Ojha, D. K.; 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.

    2012-12-01

    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 μm 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 mum) band enabling our primary motivation of mapping of Polycyclic Aromatic Hydrocarbon (PAH) emission at 3.3 mum.

  18. Underground fluid composition analysis based on the near infrared spectrum

    Science.gov (United States)

    Li, Wenxi; Liao, Yanbiao; Zhang, Min

    2011-11-01

    The near-infrared spectrum is very practical for real-time analyzing in the field of industry. This paper describes the structure of optical system, which is a part of the well logging instruments. The optical system is designed to analyze the composition of underground fluid, using the differences between oil and water in near-infrared absorption. Using Beer- Lambert law, the article analyzes the light intensity when broad-spectrum light passes through the liquid. According to the results of analysis, a group of wavelength including center wavelength and bandwidth can be selected. With each selected wavelength, light intensity changes significantly as the concentration of liquid changes. By measuring the light intensity, the system can analyse the composition of underground fluid.

  19. Mapping the Surface Composition of Venus in the Near Infrared

    OpenAIRE

    Helbert, J.; Müller, N.; Ferrari, Sabrina; Dyar, M.D.; Smrekar, S. E.; Head, J.W.; Elkins-Tanton, L.T.

    2014-01-01

    Observing the surface of Venus in the near-infrared from orbit or from an aerial platform will provide new insights into the mineralogy of Venus. In combination with a high-resolution radar mapper that provides accurate topographic data, this would allow global or regional mapping of the surface composition at a spatial scale of approximately 50km. In addition to the high scientific value of this data in itself, VEM will also provide important constraints for future landing site selections. T...

  20. 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

  1. AMBER : a near infrared focal instrument for the VLTI

    OpenAIRE

    Petrov, R. G.; Malbet, F.; Richichi, A.; Hofmann, K.H.; Mourard, Denis; Agabi, Karim; Antonelli, P.; Aristidi, Eric; Baffa, Carlo; Beckmann, Udo; Berio, Philippe; Bresson, Yves; Cassaing, Frederic; Chelli, Alain; Dreiss, Albrecht

    2001-01-01

    AMBER is the General User near-infrared focal instrument of the Very Large Telescope interferometer. Its specifications are based on three key programs on Young Stellar Objects, Active Galactic Nuclei central regions, masses and spectra of hot Extra Solar Planets. It has an imaging capacity because it combines up to three beams and very high accuracy measurement are expected from the spatial filtering of beams by single mode fibers and the comparison of measurements made simultaneously in dif...

  2. Studies of lipid oxidation in Salmon by Near infrared Spectroscopy

    OpenAIRE

    Poon, Cheau Ling

    2009-01-01

    The purpose of this study was to examine if Near infrared (NIR) spectroscopy which is a rapid and non-destructive method, can be used to determine primary and secondary lipid oxidation products in salmon oils. PV (peroxide value) and TBARS (thiobarbituric acid reactive substances) were used as chemical measures of lipid oxidation. PV measures the degree of primary oxidation products, while TBARS measures the degree of secondary oxidation products formed from the oil. NIR spectroscopy with tra...

  3. Intrinsic Near-Infrared Spectroscopic Markers of Breast Tumors

    OpenAIRE

    Shwayta Kukreti; Albert Cerussi; Bruce Tromberg; Enrico Gratton

    2009-01-01

    We have discovered quantitative optical biomarkers unique to cancer by developing a double-differential spectroscopic analysis method for near-infrared (NIR, 650–1000 nm) spectra acquired non-invasively from breast tumors. These biomarkers are characterized by specific NIR absorption bands. The double-differential method removes patient specific variations in molecular composition which are not related to cancer, and reveals these specific cancer biomarkers. Based on the spectral regions of a...

  4. Lymphatic Imaging in Humans with Near-Infrared Fluorescence

    OpenAIRE

    Rasmussen, John C.; Tan, I-Chih; Marshall, Milton V.; Fife, Caroline E.; Sevick-Muraca, Eva M

    2009-01-01

    While the lymphatic system is increasingly associated with diseases of prevalence, study of these diseases is difficult owing to the paucity of imaging techniques with the sensitivity and temporal resolution to discriminate lymphatic function. Herein, we review the known, pertinent features of the human lymphatic system in health and disease and set the context for a number of emerging studies that use near-infrared fluorescence imaging to non-invasively assess tumor draining lymphatic basins...

  5. Near infrared face recognition using Zernike moments and Hermite kernels

    Czech Academy of Sciences Publication Activity Database

    Farokhi, Sajad; Sheikh, U.U.; Flusser, Jan; Yang, Bo

    2015-01-01

    Roč. 316, č. 1 (2015), s. 234-245. ISSN 0020-0255 R&D Projects: GA ČR(CZ) GA13-29225S Keywords : face recognition * Zernike moments * Hermite kernel * Decision fusion * Near infrared Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.038, year: 2014 http://library.utia.cas.cz/separaty/2015/ZOI/flusser-0444205.pdf

  6. 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. PMID:27336412

  7. IR CMOS: near infrared enhanced digital imaging (Presentation Recording)

    Science.gov (United States)

    Pralle, Martin U.; Carey, James E.; Joy, Thomas; Vineis, Chris J.; Palsule, Chintamani

    2015-08-01

    SiOnyx has demonstrated imaging at light levels below 1 mLux (moonless starlight) at video frame rates with a 720P CMOS image sensor in a compact, low latency camera. Low light imaging is enabled by the combination of enhanced quantum efficiency in the near infrared together with state of the art low noise image sensor design. The quantum efficiency enhancements are achieved by applying Black Silicon, SiOnyx's proprietary ultrafast laser semiconductor processing technology. In the near infrared, silicon's native indirect bandgap results in low absorption coefficients and long absorption lengths. The Black Silicon nanostructured layer fundamentally disrupts this paradigm by enhancing the absorption of light within a thin pixel layer making 5 microns of silicon equivalent to over 300 microns of standard silicon. This results in a demonstrate 10 fold improvements in near infrared sensitivity over incumbent imaging technology while maintaining complete compatibility with standard CMOS image sensor process flows. Applications include surveillance, nightvision, and 1064nm laser see spot. Imaging performance metrics will be discussed. Demonstrated performance characteristics: Pixel size : 5.6 and 10 um Array size: 720P/1.3Mpix Frame rate: 60 Hz Read noise: 2 ele/pixel Spectral sensitivity: 400 to 1200 nm (with 10x QE at 1064nm) Daytime imaging: color (Bayer pattern) Nighttime imaging: moonless starlight conditions 1064nm laser imaging: daytime imaging out to 2Km

  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. Low-temperature optical characterization of a near-infrared single-photon emitter in nanodiamonds

    International Nuclear Information System (INIS)

    In this paper, we study the optical properties of single defects emitting in the near infrared (NIR) in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line (ZPL) in the NIR, the radiative lifetime is in the nanosecond range and the emission is linearly polarized. The spectral stability of the defects is then investigated. An optical resonance linewidth of 4 GHz is measured using resonant excitation on the ZPL. Although Fourier-transform-limited emission is not achieved, our results show that it might be possible to use consecutive photons emitted in the NIR by single defects in diamond nanocrystals to perform two photon interference experiments, which are at the heart of linear quantum computing protocols.

  10. Dilute nitride based double-barrier quantum-well infrared photodetector operating in the near infrared

    International Nuclear Information System (INIS)

    Near-infrared detection is reported for a double-barrier quantum-well infrared photodetector based on a 30-A GaAs1-yNy (y≅0.01) quantum well. The growth procedure using plasma-assisted molecular-beam epitaxy is described. The as-grown sample exhibits a detection wavelength of 1.64 μm at 25 K. The detection peak strengthens and redshifts to 1.67 μm following rapid thermal annealing at 850 deg. C for 30 s. The detection peak position is consistent with the calculated band structure based on the band-anticrossing model for nitrogen incorporation into GaAs

  11. Nanocomposites Polarizing by Absorption: Dichroism in the Near-Infrared Region (NIR

    Directory of Open Access Journals (Sweden)

    Lorenz Bonderer

    2014-03-01

    Full Text Available We describe the preparation of nanocomposites which exhibit dichroism in the near infrared region (NIR. These materials consist of crosslinked poly(dimethylsiloxane (PDMS and gold nanoparticles, coated with 1-dodecanethiol or tert-tetradecanethiol. The alkanethiols improve dispersibility of the gold particles, and accordingly composites were manufactured by diffusion of the particles into swollen self-supporting PDMS elastomer films. After drying, the films were exposed to solvents for one minute, stretched in wet state, dried again and annealed. This procedure led to formation of oriented linear gold particle assemblies within stretched polymer. If the aspect ratio of the particle assemblies is high, the absorption of polarized light in the NIR region is expected to depend on the angle between the polarization plane and the orientation direction of the particle assemblies, and this was observed to be the case.

  12. [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

  13. Visible/near-infrared spectra of experimentally shocked plagioclase feldspars

    Science.gov (United States)

    Johnson, Jeffrey R.; Hörz, Friedrich

    2003-11-01

    High shock pressures cause structural changes in plagioclase feldspars such as mechanical fracturing and disaggregation of the crystal lattice at submicron scales, the formation of diaplectic glass (maskelynite), and genuine melting. Past studies of visible/near-infrared spectra of shocked feldspars demonstrated few spectral variations with pressure except for a decrease in the depth of the absorption feature near 1250-1300 nm and an overall decrease in reflectance. New visible/near-infrared spectra (400-2500 nm) of experimentally shocked (17-56 GPa) albite- and anorthite-rich rock powders demonstrate similar trends, including the loss of minor hydrated mineral bands near 1410, 1930, 2250, and 2350 nm. However, the most interesting new observations are increases in reflectance at intermediate pressures, followed by subsequent decreases in reflectance at higher pressures. The amount of internal scattering and overall sample reflectance is controlled by the relative proportions of micro-fractures, submicron grains, diaplectic glass, and melts formed during shock metamorphism. We interpret the observed reflectance increases at intermediate pressures to result from progressively larger proportions of submicron feldspar grains and diaplectic glass. The ensuing decreases in reflectance occur after diaplectic glass formation is complete and the proportion of genuine melt inclusions increases. The pressure regimes over which these reflectance variations occur differ between albite and anorthite, consistent with thermal infrared spectra of these samples and previous studies of shocked feldspars. These types of spectral variations associated with different peak shock pressures should be considered during interpretation and modeling of visible/near-infrared remotely sensed spectra of planetary and asteroidal surfaces.

  14. Compressive Acquisition of Color and Near-Infrared Images

    OpenAIRE

    Sadeghipoor Kermani, Zahra; Lu, Yue; Süsstrunk, Sabine

    2014-01-01

    We propose using a single silicon sensor and a modified Bayer CFA for joint acquisition of color and near-infrared (NIR) images. Silicon sensors, which are placed in most color cameras, are inherently sensitive to NIR. Hence, our proposed design is very similar to consumer color cameras in terms of hardware. The main contribution of this work is an algorithm that estimates full-resolution color and NIR images from subsampled and mixed sensor measurements. Our method results in high-quality RG...

  15. 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

  16. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

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

    2015-01-01

    ultrasonography. RANDOMISATION: Allocation sequence 1:1 with block sizes 4 and 6 in random order concealed for the investigators. The allocation was stratified for gestational age (<26 weeks or ≥ 26 weeks). BLINDING: Cerebral oxygenation measurements were blinded in the control group. All outcome assessors were......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...... infants using a dedicated treatment guideline in combination with cerebral NIRS monitoring.Trial registration ClinicalTrial.gov NCT01590316....

  17. Near-infrared spectroscopy. Innovative technology summary report

    International Nuclear Information System (INIS)

    A near-infrared (NIR) spectroscopy system with a remote fiber-optic probe was developed and demonstrated to measure the water content of high-level radioactive wastes from the underground storage tanks at the Hanford Site in richland Washington. The technology was developed as a cost-effective and safer alternative to the thermogravimetric analysis (TGA) technique in use as the baseline. This work was supported by the Tanks Focus Area (TFA) within the Department of Energy's (DOE) Office of Science and Technology (OST) in cooperation with the Hanford Tank Waste Remediation System (TWRS) Program

  18. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sørensen, 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...... group compared with 1.1 (0.1-23.4) %hours in the control group (P=0.98). We found no statistically significant differences between the two groups at term corrected age. No severe adverse reactions were associated with the device. CONCLUSIONS: Cerebral oxygenation was stabilised in extremely preterm...

  19. Analytical applications of near-infrared fluorescent probes

    Science.gov (United States)

    Patonay, Gabor; Tarazi, Leila A.; George, Abraham; Van Aken, Koen; Gorecki, Tadeusz; Strekowski, Lucjan

    1997-05-01

    By combining near-infrared (NIR) fluorophores and commercially available laser diodes, a promising technique emerges where visible probes are less effective due to background interference. The application of NIR fluorophores in fiber-optic probes for the determination of metal ions in the environment and for biological assays will be discussed. The spectral behavior of a new NIR fluorophore TG-170 in the presence of metal ions and the first synthesis and spectral characterization of a NIR dye KVA-22 substituted with a crown ether, a metal complexing functionality, will be presented.

  20. Cartilage-Specific Near-Infrared Fluorophores for Biomedical Imaging.

    Science.gov (United States)

    Hyun, Hoon; Owens, Eric A; Wada, Hideyuki; Levitz, Andrew; Park, GwangLi; Park, Min Ho; Frangioni, John V; Henary, Maged; Choi, Hak Soo

    2015-07-20

    A novel class of near-infrared fluorescent contrast agents was developed. These agents target cartilage with high specificity and this property is inherent to the chemical structure of the fluorophore. After a single low-dose intravenous injection and a clearance time of approximately 4 h, these agents bind to all three major types of cartilage (hyaline, elastic, and fibrocartilage) and perform equally well across species. Analysis of the chemical structure similarities revealed a potential pharmacophore for cartilage targeting. Our results lay the foundation for future improvements in tissue engineering, joint surgery, and cartilage-specific drug development. PMID:26095685

  1. Endoscopically compatible near-infrared photon migration probe

    Science.gov (United States)

    Lubawy, Carmalyn; Ramanujam, Nirmala

    2004-09-01

    We have developed a 2.3-mm-diameter fiber-optic probe for near-infrared photon migration spectroscopy that can be inserted into the body through an endoscope or biopsy needle. This probe is specifically designed to be inserted into a core biopsy needle to facilitate optical sampling of lesions during breast needle biopsy. This probe was tested on tissue phantoms containing heterogeneities (to stimulate breast lesions) of various sizes and optical properties. Under the conditions tested, the probe can measure the absorption coefficient to within 30% for heterogeneities with radii as small as 10 mm.

  2. 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.

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

    DEFF Research Database (Denmark)

    Schytz, Henrik Winther

    2015-01-01

    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 in...... requires an acceptable LFOs variation between hemispheres and over time in the healthy brain. The second study therefore investigated day-to-day and hemispheric variations in LFOs with NIRS. It was shown that NIRS might be useful in assessing LFOs between hemispheres, as well as interhemispheric phase and...

  4. 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.

  5. Near-Infrared Camera Calibration for Optical Surgical Navigation.

    Science.gov (United States)

    Cai, Ken; Yang, Rongqian; Lin, Qinyong; Liu, Sujuan; Chen, Huazhou; Ou, Shanxing; Huang, Wenhua; Zhou, Jing

    2016-03-01

    Near-infrared optical tracking devices, which are important components of surgical navigation systems, need to be calibrated for effective tracking. The calibration results has a direct influence on the tracking accuracy of an entire system. Therefore, the study of calibration techniques is of theoretical significance and practical value. In the present work, a systematic calibration method based on movable plates is established, which analyzes existing calibration theories and implements methods using calibration reference objects. First, the distortion model of near-infrared cameras (NICs) is analyzed in the implementation of this method. Second, the calibration images from different positions and orientations are used to establish the required linear equations. The initial values of the NIC parameters are calculated with the direct linear transformation method. Finally, the accurate internal and external parameters of the NICs are obtained by conducting nonlinear optimization. Analysis results show that the relative errors of the left and right NICs in the tracking system are 0.244 and 0.282 % for the focal lengths and 0.735 and 1.111 % for the principal points, respectively. The image residuals of the left and right image sets are both less than 0.01 pixel. The standard error of the calibration result is lower than 1, and the measurement error of the tracking system is less than 0.3 mm. The experimental data show that the proposed method of calibrating NICs is effective and can generate favorable calibration results. PMID:26728393

  6. Airborne laser systems for atmospheric sounding in the near infrared

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

    2012-06-01

    This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

  7. 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...

  8. 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.

  9. Using near infrared light for deep sea mining observation systems

    Science.gov (United States)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  10. Near-infrared spectral methods for noninvasively measuring blood glucose

    Science.gov (United States)

    Fei, Sun; Kong, Deyi; Mei, Tao; Tao, Yongchun

    2004-05-01

    Determination of blood glucose concentrations in diabetic patients is a frequently occurring procedure and an important tool for diabetes management. Use of noninvasive detection techniques can relieve patients from the pain of frequent finger pokes and avoid the infection of disease via blood. This thesis discusses current research and analyzes the advantages and shortages of different measurement methods, including: optical methods (Transmission, Polarimetry and scattering), then, we give emphasis to analyze the technology of near-infrared (NIR) spectra. NIR spectral range 700 nm ~2300 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. In this work, we present an outline of noninvasive blood glucose measurement. A near-infrared light beam is passed through the finger, and the spectral components of the emergent beam are measured using spectroscopic techniques. The device includes light sources having the wavelengths of 600 nm - 1800 nm to illuminate the tissue. Receptors associated with the light sources for receiving light and generating a transmission signal representing the light transmitted are also provided. Once a transmission signal is received by receptors, and the high and low values from each of the signals are stored in the device. The averaged values are then analyzed to determine the glucose concentration, which is displayed on the device.

  11. Aqueous synthesis of near-infrared highly fluorescent platinum nanoclusters.

    Science.gov (United States)

    García Fernández, Jenifer; Trapiella-Alfonso, Laura; Costa-Fernández, José M; Pereiro, Rosario; Sanz-Medel, Alfredo

    2015-05-29

    A one-step synthesis of near infrared fluorescent platinum nanoclusters (PtNCs) in aqueous medium is described. The proposed optimized procedure for PtNC synthesis is rather simple, fast and it is based on the direct metal reduction with NaBH4. Bidentated thiol ligands (lipoic acid) were selected as nanoclusters stabilizers in water media. The structural characterization revealed attractive features of the PtNCs, including small size, high water solubility, near-infrared luminescence centered at 680 nm, long-term stability and the highest quantum yield in water reported so far (47%) for PtNCs. Moreover, their stability in different pH media and an ionic strength of 0.2 M NaCl was studied and no significant changes in fluorescence emission were detected. In brief, they offer a new type of fluorescent noble metal nanoprobe with a great potential to be applied in several fields, including biolabeling and imaging experiments. PMID:25944823

  12. Near infrared cathodoluminescence of III-V heterostructures

    International Nuclear Information System (INIS)

    The spectral range of the existing CL spectrometer (∼ 300 nm - 850 nm) was extended to the near infrared region of the electromagnetic spectrum by adding a liquid nitrogen-cooled germanium (Ge) diode detector. A special adapter was constructed in order to use both the existing and the near infrared apparatus in quick succession. The spectral range of the modified CL spectrometer was between ∼ 300 nm (4.13 eV) and ∼ 1800 nm (0.69 eV). The efficiency of the spectrometer was increased by ∼ 3 orders of magnitude by replacing the inefficient fibre-optic based connection with a more efficient aluminium mirror-based connection, by introducing a GaAs photomultipliers (PMT) and by carefully aligning the optical components. The efficiency of the near infrared CL spectrometer was increased by ∼ 3 orders of magnitude by adding a phase sensitive detection apparatus. The monochromator wavelength error was measured to be between ∼ -1.1 nm and +1.9 nm. The absolute response of the spectrometer was measured for the first time using a novel calibration procedure which correctly reproduced the throughput occurring during routine CL analysis. Using this spectrometer, quantitative measurements of CL intensity may be made with a precision of up to ∼ 7% in the near infrared region of the spectrum. The modified CL spectrometer had a spatial resolution of up to ∼ 200 nm and was able to detect up to ∼ 1 in 6300 photons/s in the near infrared region of the spectrum. This quantitative CL spectrometer was used to measure the black-body temperature of tungsten-strip lamps with a precision of ∼ 1-2%. The lamps may be used as tertiary radiance standards to measure the absolute response of spectrometers between ∼ 500 nm and ∼ 1050 nm. The CL spectrometer was used to study MOVPE grown InGaAsP/InP-based mesa overgrowths and InGaAsP/InP-based butt-coupled laser-waveguide devices, to be used for the fabrication of opto-electronic integrated circuits (OEICs). Growth induced

  13. 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...

  14. Alternating current thin film electroluminescence in the near infrared from zinc sulfide doped with rare earths

    Science.gov (United States)

    Kale, Ajay

    Near infrared emission (0.7--1.5 mum) of zinc sulfide (ZnS) doped with erbium (Er) or neodymium (Nd) has been studied in alternating current thin film electroluminescent devices (ACTFELDs). The electroluminescent (EL) thin film phosphors were radio frequency planar magnetron sputter deposited by co-sputtering an undoped ZnS target together with a ZnS: 1.5 mole% ErF 3 or ZnS: 1.5 mole% NdF3 target. The ZnS:ErF3 and ZnS:NdF3 thin film phosphors were annealed for one hour in ultra high purity N2 at temperatures ranging from 350--475°C. Annealing at 425°C for 1 hour in nitrogen was the optimal post-deposition treatment for both the ZnS:ErF3, and ZnS:NdF3 thin film phosphors, resulting in EL power densities of 7.5 and 28 muW/cm2 for the 990nm and the 1550nm emission of ZnS:ErF3, respectively. The power densities were 7.5 (750%) and 28 (2800%) times larger than those from the as-deposited films, which exhibited a power density ˜1muW/cm 2 at both wavelengths. In the case of ZnS:NdF3, 26 and 15 muW/cm2 deposited samples. Post-deposition annealing resulted in a 8 and 1.5 times increase in total device efficiency to 0.42 W/W and 0.7 W/W) for ZnS:ErF3 and ZnS:NdF3, respectively. This was attributed to a reduction in the concentration of shallow defects, which leads to a larger effective phosphor field and band bending, an increase in the conduction charge, and a reduction of inelastic scattering of ballistic electrons. While the peak emission wavelengths from Er were independent of annealing temperature, peak shifts were observed for Nd due to hybridization of the 5d-4f orbitals. At annealing temperatures 425°C, the shallow defect states are annealed out, leading to more efficient direct radiative relaxation from the higher lying excited states, and more intense visible luminescence is observed.

  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. Compositional stratigraphy of crustal material from near-infrared spectra

    Science.gov (United States)

    Pieters, Carle M.

    1987-01-01

    An Earth-based telescopic program to acquire near-infrared spectra of freshly exposed lunar material now contains data for 17 large impact craters with central peaks. Noritic, gabbroic, anorthositic and troctolitic rock types can be distinguished for areas within these large craters from characteristic absorptions in individual spectra of their walls and central peaks. Norites dominate the upper lunar crust while the deeper crustal zones also contain significant amounts of gabbros and anorthosites. Data for material associated with large craters indicate that not only is the lunar crust highly heterogeneous across the nearside, but that the compositional stratigraphy of the lunar crust is nonuniform. Crustal complexity should be expected for other planetary bodies, which should be studied using high spatial and spectral resolution data in and around large impact craters.

  17. 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.

  18. Review of functional near-infrared spectroscopy in neurorehabilitation.

    Science.gov (United States)

    Mihara, Masahito; Miyai, Ichiro

    2016-07-01

    We provide a brief overview of the research and clinical applications of near-infrared spectroscopy (NIRS) in the neurorehabilitation field. NIRS has several potential advantages and shortcomings as a neuroimaging tool and is suitable for research application in the rehabilitation field. As one of the main applications of NIRS, we discuss its application as a monitoring tool, including investigating the neural mechanism of functional recovery after brain damage and investigating the neural mechanisms for controlling bipedal locomotion and postural balance in humans. In addition to being a monitoring tool, advances in signal processing techniques allow us to use NIRS as a therapeutic tool in this field. With a brief summary of recent studies investigating the clinical application of NIRS using motor imagery task, we discuss the possible clinical usage of NIRS in brain-computer interface and neurofeedback. PMID:27429995

  19. Near-Infrared Spectroscopy of Young Galactic Supernova Remnants

    CERN Document Server

    Koo, Bon-Chul

    2015-01-01

    Young Galactic supernova remnants (SNRs) are where we can observe closely the supernova (SN) ejecta and its interaction with circumstellar/interstellar medium. Therefore, they provide an opportunity to explore the explosion and the final stage of the evolution of massive stars. Near-infrared (NIR) emission lines in SNRs mostly originate from shocked dense material. In shocked SN ejecta, forbidden lines from heavy ions are prominent, while in shocked circumstellar/interstellar medium, [Fe II] and H2 lines are prominent. [Fe II] lines are strong in both media, and therefore [Fe II] line images provide a good starting point for the NIR study of SNRs. There are about twenty SNRs detected in [Fe II] lines, some of which have been studied in NIR spectroscopy. We will review the NIR [Fe II] observations of SNRs and introduce our recent NIR spectroscopic study of the young core-collapse SNR Cas A where we detected strong [P II] lines.

  20. 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. PMID:24915307

  1. Near-infrared fluorescent proteins engineered from bacterial phytochromes.

    Science.gov (United States)

    Shcherbakova, Daria M; Baloban, Mikhail; Verkhusha, Vladislav V

    2015-08-01

    Near-infrared fluorescent proteins (NIR FPs), photoactivatable NIR FPs and NIR reporters of protein-protein interactions developed from bacterial phytochrome photoreceptors (BphPs) have advanced non-invasive deep-tissue imaging. Here we provide a brief guide to the BphP-derived NIR probes with an emphasis on their in vivo applications. We describe phenotypes of NIR FPs and their photochemical and intracellular properties. We discuss NIR FP applications for imaging of various cell types, tissues and animal models in basic and translational research. In this discussion, we focus on NIR FPs that efficiently incorporate endogenous biliverdin chromophore and therefore can be used as straightforward as GFP-like proteins. We also overview a usage of NIR FPs in different imaging platforms, from planar epifluorescence to tomographic and photoacoustic technologies. PMID:26115447

  2. Study of surfaces using near infrared optical fiber spectrometry

    Science.gov (United States)

    Workman, G. L.; Arendale, W. A.; Hughes, C.

    1995-01-01

    The measurement and control of cleanliness for critical surfaces during manufacturing and in service provides a unique challenge for fulfillment of environmentally benign operations. Of particular interest has been work performed in maintaining quality in the production of bondline surfaces in propulsion systems and the identification of possible contaminants. 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 surfaces. This presentation will provide an introduction to the use of optical fiber spectrometry in a nondestructive measurement system for process monitoring and how it can be used to help clarify issues concerning surface chemistry. Correlation of the Near Infrared (NIR) spectroscopic results with Optical Stimulated Electron Emission (OSEE) and ellipsometry will also be presented.

  3. Analysis of silage composition by near-infrared reflectance spectroscopy

    Science.gov (United States)

    Reeves, James B., III; Blosser, Timothy H.; Colenbrander, V. F.

    1991-02-01

    Two studies were performed to investigate the feasibility of using near infrared reflectance spectroscopy (NIRS) with undried silages. In the first study silages were analyzed for major components (e. g. dry matter crude protein and other forms of nitrogen fiber and in vitro digestible dry matter) and short chain fatty acids (SCFA). NIRS was found to operate satisfactorily except for some forms of nitrogen and SCFA. In study two various methods of grinding spectral regions and sample presentation were examined. Undried Wiley ground samples in a rectangular cell gave the best overall results for non-dry ice undried grinds with wavelengths between 1100 and 2498 nm. Silages scanned after drying however produced the best results. Intact samples did not perform as well as ground samples and wavelengths below 1100 nm were of little use. 2 .

  4. Theoretical analysis of crosstalk in near-infrared topography

    Science.gov (United States)

    Okada, E.; Okui, N.

    2006-09-01

    Crosstalk between changes in concentration of oxy-and deoxy-haemoglobin calculated by modified Lambert-Beer law in near-infrared topography is theoretically investigated. The change in intensity detected with source-detector pairs on the scalp caused by global or focal ahsorption change in the brain is predicted by Monte Carlo simulation. The topographic images of changes in oxy- and deoxy-haemoglobin are obtained from the changes in intensity detected with source-detector pairs on the scalp. The crosstalk depends on the relative position of the focal absorption change to source-detector pairs. The crosstalk is minimised when the focal absorption change is located below a measurement point that is the midpoint between a source and a detector.

  5. Portable multichannel multiwavelength near-infrared diffusive light imager

    Science.gov (United States)

    Chen, Nan Guang; Xia, Hongjun; Piao, Daqing; Zhu, Quing

    2003-07-01

    We have developed a near infrared optical tomography system features fast optical switching, three-wavelength excitations, and avalanche photodiode (APD) detectors with a high dynamic range. Pigtailed laser diodes at 660, 780, and 830 nm are used as light sources and their outputs are distributed sequentially to one of nine source fibers. The crosstalk between source channels is around 65 dB, equivalent to 130 dB in opto-electrical signals. 10 Silicon APD"s detect diffusive photon density waves simultaneously. The dynamic range of an APD is several orders higher than that of a photomultiplier tube (PMT), which eliminates the need of multi-step system gain control. However, the internal gain of the APD we are using is about 3 orders lower than an ordinary PMT. Efforts have been made to suppress the feed through interferences from the transmission part to the reception part so as to reduce the errors in amplitude and phase measurements.

  6. Near-infrared surface photometry of barred spiral galaxies

    International Nuclear Information System (INIS)

    On the basis of a number of theoretical studies, it must be concluded that bar-like stellar structures are a preferred dynamical form in the process of galaxy formation and evolution. The objective of the observational research reported in this paper is to study by surface photometry parameters which describe the radial and azimuthal luminosity distributions of the bars of barred spiral galaxies. Such information is important for a comparison with theoretical models. The observational data are discussed, taking into account the photographic material, the reduction of data, and the decomposition of the radial luminosity profiles. Attention is also given to the structure of the bars, a comparison with the Miller and Smith models, and a discussion of the results. The considered study has provided near-infrared surface photometry for the stellar bars of a number of barrel spiral galaxies. 53 references

  7. 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.

  8. 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...

  9. Deep Near-Infrared Survey toward the M17 Region

    Science.gov (United States)

    Jiang, Zhibo; Yao, Yongqiang; Yang, Ji; Ando, Minoru; Kato, Daisuke; Kawai, Toshihide; Kurita, Mikio; Nagata, Tetsuya; Nagayama, Takahiro; Nakajima, Yasushi; Nagashima, Chie; Sato, Shuji; Tamura, Motohide; Nakaya, Hidehiko; Sugitani, Koji

    2002-09-01

    We conducted a deep JHKs-band imaging survey of the M17 region, using a near-infrared camera, the Simultaneous 3-color InfraRed Imager for Unbiased Survey (SIRIUS), mounted on the InfraRed Survey Facility (IRSF) 1.4 m telescope at the South African Astronomical Observatory. This survey covers an area of ~200 arcmin2 with 10 σ limiting magnitudes of J~18.7, H~18.2, and Ks~17.5. The near-infrared (NIR) images reveal an unprecedented view of the region. The NIR nebulae are highly structured, with two nebular bars corresponding to, but a little larger than, the H II region defined by Felli, Massi, & Churchwell, constructing a conical shape. Fine structures are found all over the nebular area. The central region contains a congregation of intermediate- to high-mass stars. From the slope of the Ks-band luminosity function and the frequency of young stellar objects (YSOs) we infer that the central cluster has an age less than 3 Myr. The central OB cluster provides tremendous energy that heats and ionizes its surrounding materials, triggering the star formation of second-generation in the nebular bars. The second generation stars are so numerous that could they affect the star formation efficiency in the whole region. To the southwest of the central cluster and the nebular bars, where a giant molecular cloud core is located, a large number of red stars are detected. We argue that these red stars are most probably associated YSOs with intrinsic color excesses, not normal field stars reddened by the molecular cloud in front of them. Being located beyond the photodissociation region, the star-forming process in the molecular region could be independent of the impact of the central cluster.

  10. Asteroid 951 Gaspra Near Infrared Mapping Spectrometer Radiance Data

    Science.gov (United States)

    Granahan, J. C., Jr.

    2015-12-01

    Five radiance spectra of asteroid 951 Gaspra have been archived in the Small Bodies Node of the NASA Planetary Data System [Granahan, 2014]. The radiance spectra were created from uncalibrated Galileo spacecraft Near Infrared Mapping Spectrometer files archived in the Imaging Node of the NASA Planetary Data System. The NASA Galileo spacecraft observed asteroid 951 Gaspra on October 29, 1991 with the Near Infrared Mapping Spectrometer (NIMS) at wavelengths ranging from 0.7 - 5.2 micrometers [Carlson et al., 1992]. The five radiance spectra consist of two 17, two 100, and one 329 spectral channel data sets. They record data that was acquired by NIMS at ranges between 27232.6 to 14723.8 kilometers from asteroid 951 Gaspra. The uncalibrated NIMS data were converted into radiance spectra using calibration coefficients obtained during the Galileo mission's first Earth encounter on December 8, 1990. The archived radiance spectral data is located at the URL (Universal Record Locator): http://sbn.psi.edu/pds/resource/gaspraspec.html and contains radiance, solar, incidence over flux, and data documentation. This archived data set contains a variety of spectral signatures. These signatures include absorptions near 1.0, 2.0, 2.8, 3.4, and 4.5 micrometers. The 1.0 and 2.0 micrometer features are indicators of olivine and pyroxene on the asteroid surface. The 2.8 micrometer feature has a shape similar to the combined spectra of multiple iron bearing phyllosilicates. The 3.4 micrometer feature is in the same location as absorptions created by a carbon-hydrogen bond. The 4.5 micrometer feature, present only in the 329 channel data set, corresponds in position to absorptions detected in sulfate minerals. Carlson, R. W., et al. (1992) Bull. of the A.A.S., 24, 932. Granahan, J. C. (2014), GO-A-NIMS-3-GASPRASPEC-V1.0, NASA Planetary Data System.

  11. 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

  12. Near infrared absorbing near infrared emitting highly-sensitive luminescent nanothermometer based on Nd(3+) to Yb(3+) energy transfer.

    Science.gov (United States)

    Marciniak, Ł; Bednarkiewicz, A; Stefanski, M; Tomala, R; Hreniak, D; Strek, W

    2015-10-01

    A new type of near infrared absorbing near infrared emitting (NANE) luminescent nanothermometer is presented, with a physical background that relies on efficient Nd(3+) to Yb(3+) energy transfer under 808 nm photo-excitation. The emission spectra of LiLa0.9-xNd0.1YbxP4O12 (x = 0.05, 0.1, 0.2, 0.3, 0.5) nanocrystals were measured in a wide 100-700 °C temperature range. The ratio between the Nd(3+) ((4)F3/2→(4)I9/2) and Yb(3+) ((2)F5/2→(2)F7/2) luminescence bands, and the thermometer sensitivity were found to be strongly dependent on the Yb(3+) concentration. These phenomenological relations were discussed in terms of the competition between three phenomena, namely (a) Nd(3+)→ Yb(3+) phonon assisted energy transfer, (b) Yb(3+)→ Nd(3+) back energy transfer and (c) energy diffusion between Yb(3+) ions. The highest sensitivity of the temperature measurement was found for x = 0.5 (LiLa0.4Nd0.1Yb0.5P4O12), which was equal to 4 × 10(-3) K(-1) at 330 K. In stark contrast to conventional approaches, the proposed phosphate host matrix allows for a high level of doping, and thus, owing to the negligible concentration quenching, the presented luminophores exhibit a high absorption cross section and bright emission. Moreover, such optical remote thermometers, whose excitation and emission wavelengths are weakly scattered or absorbed and fall into the optical transmission window of the skin, may therefore become a practical solution for biomedical applications, such as remote control of thermotherapy. PMID:26327196

  13. 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

  14. Determination of Oxygen Saturation and Photoplethysmogram from Near Infrared Scattering Images

    OpenAIRE

    Ri, Yong-U; Pyon, Young-Hui; 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 ...

  15. The near infrared camera for the Subaru Prime Focus Spectrograph

    Science.gov (United States)

    Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Barkhouser, Robert; Vivès, Sebastien; Pascal, Sandrine; Carr, Michael; Hope, Stephen C.; Loomis, Craig; Hart, Murdock; Sugai, Hajime; Tamura, Naoyuki; Shimono, Atsushi

    2014-08-01

    We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 μm. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 μm. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 µm pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 μm cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 μm. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector. The camera optics and detector are packaged in a cryostat and cooled by two Stirling cycle cryocoolers. The first corrector element serves as the

  16. A near-Infrared SETI Experiment: Alignment and Astrometric precision

    Science.gov (United States)

    Duenas, Andres; Maire, Jerome; Wright, Shelley; Drake, Frank D.; Marcy, Geoffrey W.; Siemion, Andrew; Stone, Remington P. S.; Tallis, Melisa; Treffers, Richard R.; Werthimer, Dan

    2016-06-01

    Beginning in March 2015, a Near-InfraRed Optical SETI (NIROSETI) instrument aiming to search for fast nanosecond laser pulses, has been commissioned on the Nickel 1m-telescope at Lick Observatory. The NIROSETI instrument makes use of an optical guide camera, SONY ICX694 CCD from PointGrey, to align our selected sources into two 200µm near-infrared Avalanche Photo Diodes (APD) with a field-of-view of 2.5"x2.5" each. These APD detectors operate at very fast bandwidths and are able to detect pulse widths extending down into the nanosecond range. Aligning sources onto these relatively small detectors requires characterizing the guide camera plate scale, static optical distortion solution, and relative orientation with respect to the APD detectors. We determined the guide camera plate scale as 55.9+- 2.7 milli-arcseconds/pixel and magnitude limit of 18.15mag (+1.07/-0.58) in V-band. We will present the full distortion solution of the guide camera, orientation, and our alignment method between the camera and the two APDs, and will discuss target selection within the NIROSETI observational campaign, including coordination with Breakthrough Listen.

  17. 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. PMID:26971704

  18. Near Infrared Imaging of Molecular Beacons in Cancers

    Science.gov (United States)

    Chance, Britton

    2001-03-01

    The recent demonstrations of the efficacy of the tumor to background contrast in breast cancer using the tricarbo-cyanine near infrared (NIR) agent with time domain 2-D imaging presages the greater efficacy of site-directed optical contrast agents for early detection of cancers which show contrast (tissue to background) of over 20 fold. Further increases of contrast are obtained with structures that quench the fluorescence until the agent is delivered, recognized, and opened by specific enzymatic activity of the tumor. These are termed ``Molecular Beacons". In order to image the localization of the Beacons, we employ light pen ( 20μ) in LN2 gives the desired 3D high resolution image of the location of the Beacon within in the cancer cell. Since cancer prevention is linked to early detection, the high signal to background obtainable with Molecular Beacons enables the detection of very early subsurface cancers, especially breast and prostate (NIH, UIP). Thus the fluorescent Beacon excites and emits in the NIR window and signals from several cm deep in breast are detected by diffusive wave optical tomography (DWOT). Detection of objects ( 800 nm) affording 0.2 mm object detection of even low Beacon concentrations. One, two, and 3-D localization is made possible by one, two, and three orthogonal phase array null planes.

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

    CERN Document Server

    De Grijs, R

    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 usefulness of the NIR CM relation as a distance indicator for moderately to highly inclined_spiral_ galaxies_in the field_ (inclinations between ~ 80 and 90 deg); by avoiding contamination by dust the scatter in the CM relation is significantly reduced, compared to similar galaxy samples published previously. The CM relation can be used to determine distances to field spiral galaxies with M_K > -25.5, to at least M_K ~ -20. Our results, supplemented with previously published observations for which we can - to some degree - control the effects of extinction, are consistent with a universal nature of the CM relation for field spiral galaxies. High-resolution observations done with the Hubble Space Telescope can provide a ...

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

    International Nuclear Information System (INIS)

    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. Implanted near-infrared spectroscopy for cardiac monitoring

    Science.gov (United States)

    Bhunia, Sourav K.; Cinbis, Can

    2011-02-01

    Implanted Cardioverter Defibrillator (ICD) provides one of the most effective therapies for the prevention of sudden cardiac death, but also delivers some high voltage shocks inappropriately, causing morbidity and mortality. Implanted near-infrared spectroscopy (NIRS) may augment ICD arrhythmia detection by monitoring skeletal muscle perfusion. A two-wavelength, single-distance, continuous-wave implanted NIRS has been evaluated in-vivo. A weighted difference of the changes in attenuation at two wavelengths, across the isobestic point of the hemoglobin spectra, was taken to be the microvascular oxygenation trend indicator (O2 Index). Although the exact weight depends on the local vascular distribution and their oxygen levels, the hypothesis that a constant weight may be adequate for hemodynamic trending during short arrhythmic episodes, was tested. The sensor was implanted subcutaneously both on fresh tissue and inside scar tissue that formed around a pre-existing implant, in 3 animals each. Attenuations were recorded at 660 and 890 nm during normal sinus rhythm (NSR) and induced ventricular fibrillation (VF). The slope of the O2 Index over 10 seconds was computed for 7 NSR and 8 VF episodes in fresh and 13 NSR and 15 VF episodes in scar tissue pockets. The mean O2 Index slope was significantly different (pdetection of VF during electromagnetic interference, double counting of ECG T-wave as an R-wave, ICD lead failure, electrocardiographic aberrancy etc.

  2. Near-infrared measurements of brain oxygenation in stroke.

    Science.gov (United States)

    Moreau, François; Yang, Runze; Nambiar, Vivek; Demchuk, Andrew M; Dunn, Jeff F

    2016-07-01

    We investigated the feasibility of using frequency-domain near-infrared spectroscopy (fdNIRS) to study brain oxygenation in the first few hours of stroke onset. The OxiplexTS(®) fdNIRS system was used in this study. Using a standard probing protocol based on surface landmarks, we measured brain tHb and [Formula: see text] in healthy volunteers, cadavers, and acute stroke patients within 9 h of stroke onset and 3 days later. We obtained measurements from 11 controls, 5 cadavers, and 5 acute stroke patients. [Formula: see text] values were significantly lower in cadavers compared to the controls and stroke patients. Each stroke patient had at least one area with reduced [Formula: see text] on the stroke side compared to the contralateral side. The evolution of tHb and [Formula: see text] at 3 days differed depending on whether a large infarct occurred. This study shows the proof of principle that quantified measurements of brain oxygenation using NIRS could be used in the hectic environment of acute stroke management. It also highlights the current technical limitations and future challenges in the development of this unique bedside monitoring tool for stroke. PMID:26958577

  3. 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...

  4. 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...

  5. The Phoenix Deep Survey: Optical and near infrared imaging catalogs

    CERN Document Server

    Sullivan, M; Afonso, J; Georgakakis, A; Chan, B; Cram, L; Mobasher, B; Almeida, C; Sullivan, Mark; Hopkins, Andrew; Afonso, Jose; Georgakakis, Antonis; Chan, Ben; Cram, Lawrence; Mobasher, Bahram; Almeida, Cesario

    2004-01-01

    The Phoenix Deep Survey is a multi-wavelength galaxy survey based on deep 1.4 GHz radio imaging (Hopkins et al., 2003). The primary goal of this survey is to investigate the properties of star formation in galaxies and to trace the evolution in those properties to a redshift z=1, covering a significant fraction of the age of the Universe. By compiling a sample of star-forming galaxies based on selection at radio wavelengths we eliminate possible biases due to dust obscuration, a significant issue when selecting objects at optical and ultraviolet wavelengths. In this paper, we present the catalogs and results of deep optical (UBVRI) and near-infrared (Ks) imaging of the deepest region of the existing decimetric radio imaging. The observations and data-processing are summarised and the construction of the optical source catalogs described, together with the details of the identification of candidate optical counterparts to the radio catalogs. Based on our UBVRIKs imaging, photometric redshift estimates for the ...

  6. Near-infrared imaging spectroscopy for counterfeit drug detection

    Science.gov (United States)

    Arnold, Thomas; De Biasio, Martin; Leitner, Raimund

    2011-06-01

    Pharmaceutical counterfeiting is a significant issue in the healthcare community as well as for the pharmaceutical industry worldwide. The use of counterfeit medicines can result in treatment failure or even death. A rapid screening technique such as near infrared (NIR) spectroscopy could aid in the search for and identification of counterfeit drugs. This work presents a comparison of two laboratory NIR imaging systems and the chemometric analysis of the acquired spectroscopic image data. The first imaging system utilizes a NIR liquid crystal tuneable filter and is designed for the investigation of stationary objects. The second imaging system utilizes a NIR imaging spectrograph and is designed for the fast analysis of moving objects on a conveyor belt. Several drugs in form of tablets and capsules were analyzed. Spectral unmixing techniques were applied to the mixed reflectance spectra to identify constituent parts of the investigated drugs. The results show that NIR spectroscopic imaging can be used for contact-less detection and identification of a variety of counterfeit drugs.

  7. 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.

  8. Near-infrared oxygen airglow from the Venus nightside

    Science.gov (United States)

    Crisp, D.; Meadows, V. S.; Allen, D. A.; Bezard, B.; Debergh, C.; Maillard, J.-P.

    1992-01-01

    Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus.

  9. Near-infrared laser diodes in monitoring applications

    Science.gov (United States)

    Patonay, Gabor; Zen, Jyh-Myng; Czuppon, Tibor

    1992-05-01

    Absorption and fluorescence spectroscopy has proven to be a valuable analytical tool for environmental and process monitoring. Several publications have addressed different spectroscopic applications related to process monitoring. Since most chemicals absorb in the UVIVis part of the spectrum, the majority of laser applications utilize this shorter wavelength region. Nevertheless, the utilization of the longer wavelength part of the electromagnetic spectrum may be advantageous due to its relatively low interference. The environmental and process monitoring applications of this spectral region may be especially advantageous if semiconductor lasers are utilized as light sources. Laser diodes have all the properties of other types of lasers with the added benefits of compactness, low power consumption, low cost and long lifetime. However, to utilize this spectral region for environmental or process monitoring applications, appropriate near-infrared (NIR) absorbing probe molecules need to be employed. These probes may be used to determine analytical properties important for environmental or process monitoring applications, e.g., pH, oxygen concentration, metal ion determinations, solvent hydrophobicity, just to mention a few. These NIR probes may be incorporated into polymers to form a stable probe arrangement for convenient monitoring using semiconductor lasers. The utility can be further enhanced using fiber optics. In this paper the use of MR absorption and fluorescence spectroscopy for monitoring applications will be demonstrated.

  10. Near Infrared Light-Powered Janus Mesoporous Silica Nanoparticle Motors.

    Science.gov (United States)

    Xuan, Mingjun; Wu, Zhiguang; Shao, Jingxin; Dai, Luru; Si, Tieyan; He, Qiang

    2016-05-25

    We describe fuel-free, near-infrared (NIR)-driven Janus mesoporous silica nanoparticle motors (JMSNMs) with diameters of 50, 80, and 120 nm. The Janus structure of the JMSNMs is generated by vacuum sputtering of a 10 nm Au layer on one side of the MSNMs. Upon exposure to an NIR laser, a localized photothermal effect on the Au half-shells results in the formation of thermal gradients across the JMSNMs; thus, the generated self-thermophoresis can actively drive the nanomotors to move at an ultrafast speed, for instance, up to 950 body lengths/s for 50 nm JMSNMs under an NIR laser power of 70.3 W/cm(2). The reversible "on/off" motion of the JMSNMs and their directed movement along the light gradient can be conveniently modulated by a remote NIR laser. Moreover, dynamic light scattering measurements are performed to investigate the coexisting translational and rotational motion of the JMSNMs in the presence of both self-thermophoretic forces and strong Brownian forces. These NIR-powered nanomotors demonstrate a novel strategy for overcoming the necessity of chemical fuels and exhibit a significant improvement in the maneuverability of nanomotors while providing potential cargo transportation in a biofriendly manner. PMID:27152728

  11. 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...

  12. Near infrared light responsive hybrid nanoparticles for synergistic therapy.

    Science.gov (United States)

    Liang, Yan; Gao, Wenxia; Peng, Xinyu; Deng, Xin; Sun, Changzhen; Wu, Huayue; He, Bin

    2016-09-01

    A near infrared (NIR) light responsive chromophore 7-(diethylamino)-4-(hydroxymethyl)-2H-chromen-2-one (DEACM) was synthesized and incorporated to β-cyclodextrins with cRGD functionalized poly(ethylene glycol), the amphiphiles were coordinated with Au nanorods or nanoparticles to load anticancer drug doxorubicin (DOX) for fabricating hybrid nanoparticles. The π-π stacking interaction between DEACM and DOX was formed in the hybrid nanoparticles, which contributed to the high drug loading content. The Au nanorods or nanoparticles enhanced the photosolvolysis of DEACM under the irradiation of NIR with 808 nm wavelength and triggered the accelerated drug release from the nanoparticles. The drug loaded hybrid nanoparticles with NIR irradiation exhibited efficient inhibition effect on the proliferation of 4T1 breast cancer cells in vitro. The in vivo anticancer activity study on breast cancer bearing mice revealed that the hybrid nanoparticles containing Au nanorods exhibited excellent anticancer activity under the irradiation of 808 nm wavelength NIR with 800 mW. PMID:27244691

  13. Application of functional near-infrared spectroscopy in psychiatry.

    Science.gov (United States)

    Ehlis, Ann-Christine; Schneider, Sabrina; Dresler, Thomas; Fallgatter, Andreas J

    2014-01-15

    Two decades ago, the introduction of functional near-infrared spectroscopy (fNIRS) into the field of neuroscience created new opportunities for investigating neural processes within the human cerebral cortex. Since then, fNIRS has been increasingly used to conduct functional activation studies in different neuropsychiatric disorders, most prominently schizophrenic illnesses, affective disorders and developmental syndromes, such as attention-deficit/hyperactivity disorder as well as normal and pathological aging. This review article provides a comprehensive overview of state of the art fNIRS research in psychiatry covering a wide range of applications, including studies on the phenomenological characterization of psychiatric disorders, descriptions of life-time developmental aspects, treatment effects, and genetic influences on neuroimaging data. Finally, methodological shortcomings as well as current research perspectives and promising future applications of fNIRS in psychiatry are discussed. We conclude that fNIRS is a valid addition to the range of neuroscientific methods available to assess neural mechanisms underlying neuropsychiatric disorders. Future research should particularly focus on expanding the presently used activation paradigms and cortical regions of interest, while additionally fostering technical and methodological advances particularly concerning the identification and removal of extracranial influences on fNIRS data as well as systematic artifact correction. Eventually, fNIRS might be a useful tool in practical psychiatric settings involving both diagnostics and the complementary treatment of psychological disorders using, for example, neurofeedback applications. PMID:23578578

  14. Near-infrared fluorescent dyes for fiber optic sensing

    Science.gov (United States)

    Patonay, Gabor; Kim, Jun Seok; Medou-Ovono, Martial; Strekowski, Lucjan

    2005-05-01

    Fiber optic sensing requires the use of molecular probes such as fluorescent dyes or indicators that can be induced during analysis to produce a detectable spectral change. Spectroscopic techniques have long been applied to the determination of analytical and bioanalytical measurements using fiber optic sensors; however, relatively few studies have been reported utilizing near-infrared (NIR) absorbing chromophores. This longer wavelength region of the electromagnetic spectrum is more advantageous because of the inherently lower background interference and the high molar absorptivities of NIR absorbing chromophores. Low background interference is especially important in samples containing a complex matrix. The design and operation of an NIR probe are similar to that of conventional UV-visible probes. In principle optical fiber or other optical sensors can be made selective to a particular analyte. The selectivity will be determined primarily by the selectivity of the sensor dye and by the nature of the matrix entrapping the dye if the probe is non-covalently attached. This presentation discusses the development of different NIR dyes for fiber optic sensor applications. Examples are given for determining basic analytical properties, e.g., pH, metal ion concentration, and solvent hydrophobicity. Similarly, NIR dyes are very useful for bioanalytical probes (immunochemistry, etc.) as well.

  15. 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.

  16. 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...

  17. 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. PMID:26427443

  18. Analyzing near-infrared images for utility assessment

    Science.gov (United States)

    Salamati, Neda; Sadeghipoor, Zahra; Süsstrunk, Sabine

    2011-03-01

    Visual cognition is of significant importance in certain imaging applications, such as security and surveillance. In these applications, an important issue is to determine the cognition threshold, which is the maximum distortion level that can be applied to the images while still ensuring that enough information is conveyed to recognize the scene. The cognition task is usually studied with images that represent the scene in the visible part of the spectrum. In this paper, our goal is to evaluate the usefulness of another scene representation. To this end, we study the performance of near-infrared (NIR) images in cognition. Since surface reflections in the NIR part of the spectrum is material dependent, an object made of a specific material is more probable to have uniform response in the NIR images. Consequently, edges in the NIR images are likely to correspond to the physical boundaries of the objects, which are considered to be the most useful information for cognition. This feature of the NIR images leads to the hypothesis that NIR is better than a visible scene representation to be used in cognition tasks. To test this hypothesis, we compared the cognition thresholds of NIR and visible images performing a subjective study on 11 scenes. The images were compressed with different compression factors using JPEG2000 compression. The results of this subjective test show that recognizing 8 out of the 11 scenes is significantly easier based on the NIR images when compared to their visible counterparts.

  19. 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. PMID:25625132

  20. The Visible and Near Infrared module of EChO

    CERN Document Server

    Adriani, A; Gambicorti, L; Focardi, M; Oliva, E; Farina, M; Di Giorgio, A M; Santoli, F; Pace, E; Piccioni, G; Filacchione, G; Pancrazzi, M; Tozzi, A; Micela, G

    2014-01-01

    The Visible and Near Infrared (VNIR) is one of the modules of EChO, the Exoplanets Characterization Observatory proposed to ESA for an M-class mission. EChO is aimed to observe planets while transiting by their suns. Then the instrument had to be designed to assure a high efficiency over the whole spectral range. In fact, it has to be able to observe stars with an apparent magnitude Mv= 9-12 and to see contrasts of the order of 10-4 - 10-5 necessary to reveal the characteristics of the atmospheres of the exoplanets under investigation. VNIR is a spectrometer in a cross-dispersed configuration, covering the 0.4-2.5 micron spectral range with a resolving power of about 330 and a field of view of 2 arcsec. It is functionally split into two channels respectively working in the 0.4-1 and 1.0-2.5 micron spectral ranges. Such a solution is imposed by the fact the light at short wavelengths has to be shared with the EChO Fine Guiding System (FGS) devoted to the pointing of the stars under observation. The spectromete...

  1. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy.

    Science.gov (United States)

    Pociask, Elżbieta; Jaworek-Korjakowska, Joanna; Malinowski, Krzysztof Piotr; Roleder, Tomasz; Wojakowski, Wojciech

    2016-01-01

    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. PMID:27610191

  2. 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.

  3. Phase-amplitude crosstalk in intensity modulated near infrared spectroscopy

    Science.gov (United States)

    Alford, K.; Wickramasinghe, Y.

    2000-05-01

    Near infrared spectroscopy (NIRS) instruments that rely on phase sensitive detection suffer from what is called "phase-amplitude crosstalk," i.e., the phase measured is dependent on the average light intensity entering the detector. Changes in detector rise time with input light intensity is the accepted explanation of this phenomenon. It is concluded here that an additional simple mechanism can cause phase-amplitude errors, particularly if the ratio of the ac component of the detected signal to the dc component is low. It is shown that the form of the phase distortion encountered during the development of a new phase sensitive NIR instrument can be modeled by assuming the presence of a synchronous interfering signal, due to rf coupling, at the detector output. This modeling allows a required margin between the detected signal of interest, i.e., the signal from the tissue and the interfering signal to be set in order to achieve a measured phase accuracy necessary to derive sufficiently accurate clinical parameters.

  4. Near-infrared detectors for ITER LIDAR Thomson scattering

    International Nuclear Information System (INIS)

    In this paper we discuss strategies for the development of fast photodetectors suitable for operation in the λ > 850 nm near-infrared (NIR) spectral region in the ITER core LIDAR Thomson scattering (TS) system. Detection of this spectral range is necessary if a Nd:YAG laser operating at the fundamental wavelength (λ = 1.06 μm) will be used as the input laser source. Different types of NIR photodetectors are potentially suitable for use in ITER LIDAR TS: the transferred electron (TE) InGaAsP/InP hybrid photodiodes and microchannel plate photomultipliers (MCP PMTs), the InxGa1-xAs MCP image intensifiers and PMTs, and the detectors based on transmission Si photocathodes. But their characteristics of either sensitivity, active area or speed of response, do not match the ITER specifications and all devices require some developmental work. For each of these detector types we review the characteristics of devices presently available and suggest a realistic development strategy suitable to extend their performances to meet the ITER specifications. Finally the expected performance of the ITER LIDAR TS system for different detector choices are compared by calculating the expected signal-to-noise ratio of the measured plasma temperature and density.

  5. Studying hot exozodiacal dust with near-infrared interferometry

    Science.gov (United States)

    Absil, Olivier; Defrère, Denis; Le Bouquin, Jean-Baptiste; Mollier, Benjamin; Augereau, Jean-Charles; Coudé du Foresto, Vincent; Di Folco, Emmanuel; Ertel, Steve; ten Brummelaar, Theo

    2012-07-01

    Since our first detection of a resolved near-infrared emission around the main sequence star Vega, which we identified as the signature of hot dust grains close to the sublimation limit, we have been systematically searching for similar signatures around a magnitude-limited sample of nearby main sequence stars with the FLUOR instrument at the CHARA array. About 40 targets with spectral types ranging from A to K have been observed within the last 6 years, leading to first statistical trends on the occurence of the bright exozodi phenomenon as a function of spectral type. Our target sample is balanced between stars known to harbour cold dust populations from space-based missions (e.g., Spitzer, Herschel) and stars without cold dust, so that the occurence of abundant hot dust can also be correlated with the presence of large reservoirs of cold planetesimals. In this paper, we present preliminary conclusions from the CHARA/FLUOR survey. We also discuss the first results obtained in 2011/2012 with the new PIONIER visiting instrument at the VLTI, which is now used to extend our survey sample to the Southern hemisphere and to fainter targets. A first measurement of the exozodi/star flux ratio as a function of wavelength within the H band is presented, thanks to the low spectral resolution capability of PIONIER. Finally, we also briefly discuss our plans for extending the survey to fainter targets in the Northern hemisphere with an upgraded version of the FLUOR beam combiner.

  6. 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. PMID:25172747

  7. Near infrared Raman spectroscopy for Alzheimer's disease detection

    Science.gov (United States)

    Sudworth, Caroline D.; Archer, John K. J.; Mann, David

    2005-08-01

    In recent years, the use of Raman spectroscopy for the detection and diagnosis of disease has steadily grown within the research field. However, this research has primarily been restricted to oncology. This research expands the use of Raman spectroscopy as a potential tool for the diagnosis of Alzheimer's disease, which is currently the most prevalent, and fastest growing type of dementia in the Western world. Using a commercial Raman spectrometer (Renishaw PLC ®, UK) flash frozen post-mortem ex vivo brain tissue sections were illuminated using a high power (20mW) 830 nm near infrared diode laser, and subsequently spectra were gained in the region of 2000-200 cm-1 from a 10 second accumulation time. Ethical approval was gained for the examination of 18 individual donors exhibiting varying states of Alzheimer's disease, Huntingdon's disease and their corresponding age-matched healthy controls. Following on from previous preliminary studies, the Raman spectra were found to be highly reproducible, and when examined further, the spectra showed differences relating to the content and structure of the proteins in the individual brain samples, in particular, the beta-amyloid protein structure found in Alzheimer's disease patients. Principle components analysis further determined these protein structural changes, with Alzheimer's disease and Huntingdon's disease samples being defined from the healthy controls, and from each other.

  8. 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.

  9. Graphene surface plasmons at the near-infrared optical regime

    Science.gov (United States)

    Zhang, Qiming; Li, Xiangping; Hossain, Md Muntasir; Xue, Yunzhou; Zhang, Jie; Song, Jingchao; Liu, Jingying; Turner, Mark D.; Fan, Shanhui; Bao, Qiaoliang; Gu, Min

    2014-01-01

    Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back electrical gating and chemical doping methods cannot facilitate the demonstration of graphene SPs at the near-infrared (NIR) window because of the limited shift of the Fermi level. Here, we present the evidence for the existence of graphene SPs on a tapered graphene-silicon waveguide tip at a NIR wavelength, employing a surface carrier transfer method with molybdenum trioxides. The coupling between the graphene surface plasmons and the guiding mode in silicon waveguides allows for the observation of the concentrated field of the SPs in the tip by near-field scanning optical microscopy. Thus the hot spot from the concentrated SPs in the graphene layer can be used as a key experimental signature of graphene SPs. The NIR graphene SPs opens a new perspective for optical communications, optical sensing and imaging, and optical data storage with extreme spatial confinement, broad bandwidth and high tunability. PMID:25297570

  10. 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.

  11. 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...

  12. 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.

  13. Clutter and signatures from near infrared testbed sensor

    Science.gov (United States)

    Sanderson, R. B.; McCalmont, J. F.; Montgomery, J. B.; Johnson, R. S.; McDermott, D. J.

    2008-04-01

    A new tactical airborne multicolor missile warning testbed was developed as part of an Air Force Research Laboratory (AFRL) initiative focusing on the development of sensors operating in the near infrared where commercially available silicon detectors can be used. At these wavelengths, the rejection of solar induced false alarms is a critical issue. Multicolor discrimination provides one of the most promising techniques for improving the performance of missile warning sensors, particularly for heavy clutter situations. This, in turn, requires that multicolor clutter data be collected for both analysis and algorithm development. The developed sensor test bed, as described in previous papers1, is a two-camera system with 1004x1004 FPA coupled with optimized filters integrated with the optics. The collection portion includes a high speed processor coupled with a high capacity disk array capable of collecting up to 48 full frames per second. This configuration allows the collection of temporally correlated, radiometrically calibrated data in two spectral bands that provide a basis for evaluating the performance of spectral discrimination algorithms. The presentation will describe background and clutter data collected from ground and flight locations in both detection and guard bands and the statistical analysis to provide a basis for evaluation of sensor performance. In addition, measurements have been made of discrete targets, both threats and false alarms. The results of these measurements have shown the capability of these sensors to provide a useful discrimination capability to distinguish threats from false alarms.

  14. Quantitative Tissue Spectroscopy of Near Infrared Fluorescent Nanosensor Implants.

    Science.gov (United States)

    Iverson, Nicole M; Bisker, Gili; Farias, Edgardo; Ivanov, Vsevolod; Ahn, Jiyoung; Wogan, Gerald N; Strano, Michael S

    2016-05-01

    Implantable, near infrared (nIR) fluorescent nanosensors are advantageous for in vivo monitoring of biological analytes since they can be rendered selective for a particular target molecule while utilizing their unique optical properties and the nIR tissue transparency window for information transfer without an internal power source or telemetry. However, basic questions remain regarding the optimal encapsulation platform, geometrical properties, and concentration ranges required for high signal to noise ratio and effective detection through biological tissue. In this work, we systematically explore these variables quantitatively to optimize the performance of such optical nanosensors for biomedical applications. We investigate both alginate and polyethylene glycol (PEG) as model hydrogel systems, encapsulating d(GT)15 ssDNA-wrapped single-walled carbon nanotubes (SWNT) as model fluorescent nanoparticle sensors, responsive to riboflavin. Hydrogel sensors implanted 0.5 mm into thick tissue samples exhibit 50% reduction of initial fluorescence intensity, allowing an optical detection limit of 5.4 mm and 5.1 mm depth in tissue for alginate and PEG gels, respectively, at a SWNT concentration of 10 mg L(-1), and 785 nm laser excitation of 80 mW and 30 s exposure. These findings are supported with in vivo nIR fluorescent imaging of SWNT hydrogels implanted subcutaneously in mice. For the case of SWNT, we find that the alginate system is preferable in terms of emission intensity, sensor response, rheological properties, and shelf life. PMID:27305824

  15. Near-infrared light absorption by polycrystalline SiSn alloys grown on insulating layers

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Masashi, E-mail: kurosawa@alice.xtal.nagoya-u.ac.jp [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Kato, Motohiro; Yamaha, Takashi; Taoka, Noriyuki; Nakatsuka, Osamu [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Zaima, Shigeaki [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-04-27

    High-Sn-content SiSn alloys are strongly desired for the next-generation near-infrared optoelectronics. A polycrystalline growth study has been conducted on amorphous SiSn layers with a Sn-content of 2%–30% deposited on either a substrate of SiO{sub 2} or SiN. Incorporating 30% Sn into Si permits the crystallization of the amorphous layers at annealing temperatures below the melting point of Sn (231.9 °C). Composition analyses indicate that approximately 20% of the Sn atoms are substituted into the Si lattice after solid-phase crystallization at 150–220 °C for 5 h. Correspondingly, the optical absorption edge is red-shifted from 1.12 eV (Si) to 0.83 eV (Si{sub 1−x}Sn{sub x} (x ≈ 0.18 ± 0.04)), and the difference between the indirect and direct band gap is significantly reduced from 3.1 eV (Si) to 0.22 eV (Si{sub 1−x}Sn{sub x} (x ≈ 0.18 ± 0.04)). These results suggest that with higher substitutional Sn content the SiSn alloys could become a direct band-gap material, which would provide benefits for Si photonics.

  16. Near-infrared light absorption by polycrystalline SiSn alloys grown on insulating layers

    International Nuclear Information System (INIS)

    High-Sn-content SiSn alloys are strongly desired for the next-generation near-infrared optoelectronics. A polycrystalline growth study has been conducted on amorphous SiSn layers with a Sn-content of 2%–30% deposited on either a substrate of SiO2 or SiN. Incorporating 30% Sn into Si permits the crystallization of the amorphous layers at annealing temperatures below the melting point of Sn (231.9 °C). Composition analyses indicate that approximately 20% of the Sn atoms are substituted into the Si lattice after solid-phase crystallization at 150–220 °C for 5 h. Correspondingly, the optical absorption edge is red-shifted from 1.12 eV (Si) to 0.83 eV (Si1−xSnx (x ≈ 0.18 ± 0.04)), and the difference between the indirect and direct band gap is significantly reduced from 3.1 eV (Si) to 0.22 eV (Si1−xSnx (x ≈ 0.18 ± 0.04)). These results suggest that with higher substitutional Sn content the SiSn alloys could become a direct band-gap material, which would provide benefits for Si photonics

  17. Metallic lead nanospheres discovered in ancient zircons.

    Science.gov (United States)

    Kusiak, Monika A; Dunkley, Daniel J; Wirth, Richard; Whitehouse, Martin J; Wilde, Simon A; Marquardt, Katharina

    2015-04-21

    Zircon (ZrSiO4) is the most commonly used geochronometer, preserving age and geochemical information through a wide range of geological processes. However, zircon U-Pb geochronology can be affected by redistribution of radiogenic Pb, which is incompatible in the crystal structure. This phenomenon is particularly common in zircon that has experienced ultra-high temperature metamorphism, where ion imaging has revealed submicrometer domains that are sufficiently heterogeneously distributed to severely perturb ages, in some cases yielding apparent Hadean (>4 Ga) ages from younger zircons. Documenting the composition and mineralogy of these Pb-enriched domains is essential for understanding the processes of Pb redistribution in zircon and its effects on geochronology. Using high-resolution scanning transmission electron microscopy, we show that Pb-rich domains previously identified in zircons from East Antarctic granulites are 5-30 nm nanospheres of metallic Pb. They are randomly distributed with respect to zircon crystallinity, and their association with a Ti- and Al-rich silica melt suggests that they represent melt inclusions generated during ultra-high temperature metamorphism. Metallic Pb is exceedingly rare in nature and previously has not been reported in association with high-grade metamorphism. Formation of these metallic nanospheres within annealed zircon effectively halts the loss of radiogenic Pb from zircon. Both the redistribution and phase separation of radiogenic Pb in this manner can compromise the precision and accuracy of U-Pb ages obtained by high spatial resolution methods. PMID:25848043

  18. Thermoluminescence of zircon: a kinetic model

    OpenAIRE

    Turkin, AA; Van Es, HJ; Vainshtein, DI; den Hartog, HW

    2003-01-01

    The mineral zircon, ZrSiO4, belongs to a class of promising materials for geochronometry by means of thermoluminescence (TL) dating. The development of a reliable and reproducible method for TL dating with zircon requires detailed knowledge of the processes taking place during exposure to ionizing radiation, long-term storage, annealing at moderate temperatures and heating at a constant rate (TL measurements). To understand these processes one needs a kinetic model of TL. This paper is devote...

  19. 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...

  20. A near infrared luminescent metal-organic framework for temperature sensing in the physiological range.

    Science.gov (United States)

    Lian, Xiusheng; Zhao, Dian; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-12-28

    A near infrared pumped luminescent metal-organic framework thermometer Nd(0.577)Yb(0.423)BDC-F4, with near infrared fluorescence and excellent sensitivity in the physiological temperature range (293-313 K), has been first realized, and might be potentially applied for biomedical systems. PMID:26489451

  1. 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.

  2. Nondestructive Assessment of Engineered Cartilage Composition by Near Infrared Spectroscopy.

    Science.gov (United States)

    McGoverin, Cushla M; Hanifi, Arash; Palukuru, Uday P; Yousefi, Farzad; Glenn, Padraig B M; Shockley, Michael; Spencer, Richard G; Pleshko, Nancy

    2016-03-01

    Tissue engineering presents a strategy to overcome the limitations of current tissue healing methods. Scaffolds, cells, external growth factors and mechanical input are combined in an effort to obtain constructs with properties that mimic native tissues. However, engineered constructs developed using similar culture environments can have very different matrix composition and biomechanical properties. Accordingly, a nondestructive technique to assess constructs during development such that appropriate compositional endpoints can be defined is desirable. Near infrared spectroscopy (NIRS) analysis is a modality being investigated to address the challenges associated with current evaluation techniques, which includes nondestructive compositional assessment. In the present study, cartilage tissue constructs were grown using chondrocytes seeded onto polyglycolic acid (PGA) scaffolds in similar environments in three separate tissue culture experiments and monitored using NIRS. Multivariate partial least squares (PLS) analysis models of NIR spectra were calculated and used to predict tissue composition, with biochemical assay information used as the reference data. Results showed that for combined data from all tissue culture experiments, PLS models were able to assess composition with significant correlations to reference values, including engineered cartilage water (at 5200 cm(-1), R = 0.68, p = 0.03), proteoglycan (at 4310 cm(-1), R = 0.82, p = 0.007), and collagen (at 4610 cm(-1), R = 0.84, p = 0.005). In addition, degradation of PGA was monitored using specific NIRS frequencies. These results demonstrate that NIR spectroscopy combined with multivariate analysis provides a nondestructive modality to assess engineered cartilage, which could provide information to determine the optimal time for tissue harvest for clinical applications. PMID:26817457

  3. Fetal oxygenation measurement using wireless near infrared spectroscopy

    Science.gov (United States)

    Macnab, Andrew; Shadgan, Babak; Janssen, Patricia; Rurak, Dan

    2012-03-01

    Background: Fetal well-being is determined in large part by how well the placenta is able to supply oxygen and nutrients, but current technology is unable to directly measure how well a placenta functions. Near-infrared spectroscopy (NIRS) utilizes optical methods to measure tissue oxygenation. This pilot project evaluated the feasibility of NIRS for fetal monitoring through the maternal abdominal wall using a sheep model. Methods: A miniature wireless 2-wavelength NIRS device was placed on the abdominal skin over the placenta of a pregnant ewe whose fetus had been chronically catheterized to allow arterial sampling for measurement of arterial oxygen saturation. The NIRS device has 3-paired light emitting diodes and a single photodiode detector; allowing measurement of an index of tissue oxygen saturation (TSI%). Fetal limb TSI% values were compared before and during fetal breathing movements. Correlation was made during these events between arterial values and placental TSI% monitored continuously in real time. Results: Serial measurements were obtained in a single experiment. The correlation between transcutaneous NIRS derived TSI% and direct arterial oxygen saturation was very high (R2=0.86). Measures of fetal limb TSI% were declined after episodes of fetal breathing (P<0.005). Conclusions: This correlation suggests that NIRS is sensitive enough to detect changes in fetal tissue oxygenation noninvasively through the maternal abdominal wall in real-time in a sheep model. NIRS data confirmed that fetal breathing movements decrease arterial oxygen saturation in fetal lambs. If validated by further study this optical methodology could be applied as means of monitoring fetal wellbeing in humans.

  4. 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. PMID:26041069

  5. 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.

  6. [Determination of adulteration in honey using near-infrared spectroscopy].

    Science.gov (United States)

    Chen, Lan-Zhen; Zhao, Jing; Ye, Zhi-Hua; Zhong, Yan-Ping

    2008-11-01

    The objective of the present research is to study the potential of using Fourier transform near-infrared spectroscopy (FT-NIR) in conjunction with discriminant partial least squares (DPLS) chemometric techniques for the discrimination of honey authenticity. First, seventy one commercial honey samples from Chinese market were analyzed to detect the levels of honey adulteration by stable carbon isotope ratio and the chemical result showed that the samples include unadulterated (n = 27) and adulterated (n = 44) products. The samples were scanned in the spectral region between 4 000 and 11 000 cm(-1) by FT-NIR spectrometer with an optic fiber of 2 mm path-length and an InGaAs detector and then divided randomly five times into two sets, namely calibration sets and validation sets, respectively. Five kinds of mathematic models of honey samples were established for classification of honeys as authentic or adulterated by using DPLS. Different spectra pretreatment methods, spectral range and different principal component factors were selected to optimize the calibration models. The calibration models were successfully validated with exterior cross-validation methods. Through comparison analysis of the results, the overall corrected identification rate of authentic and adulterated honey samples in five calibration models were 91.49%, 94.68%, 92.98%, 93.86% and 94.87%, respectively. The correct classification rate of the validation samples was 93.75%, 89.58%, 89.29%, 92.31% and 86.96% from model one to model five, respectively and 100% of adulterated honey samples were correctly identified and classified in validation models 2, 3 and 4. The results demonstrated that FT-NIR together with DPLS could be used as a rapid and cost-efficient screening tool for discrimination of commercial honey adulteration, and the analytical technique would be significant to Chinese honey quality supervision. PMID:19271491

  7. 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.

  8. Near-infrared mapping of spiral barred galaxies

    International Nuclear Information System (INIS)

    The results presented were obtained with a 32 x 32 InSb charge injection device (CID) array cooled at 4K, at the f/36 cassegrain focus of the 3m60 Canada-France-Hawaii telescope with a spatial resolution of 0.5 inches per pixel. The objects presented are spiral barred galaxies mapped at J(1.25 microns), H(1.65 microns) and K(2.2 microns). The non-axisymetric potential due to the presence of a bar induces dynamical processes leading to the confinement of matter and peculiar morphologies. Infrared imaging is used to study the link between various components. Correlations with other wavelengths ranges and 2-colors diagrams ((J-H), (H-K)) lead to the identification of star forming regions, nucleus. Maps show structures connected to the central core. The question is, are they flowing away or toward the nucleus. Observations of M83 lead to several conclusions. The star forming region, detected in the visible and the infrared cannot be very compact and must extend to the edge of the matter concentration. The general shape of the near-infrared emission and the location of radio and 10 micron peaks suggest the confinement of matter between the inner Linblad resonances localized from CO measurements about 100 and 400 pc. The distribution of color indices in the arc from southern part to the star forming region suggests an increasing amount of gas and a time evolution eventually triggered by supernova explosions. Close to the direction of the bar, a bridge-like structure connects the arc to the nucleus with peculiar color indices

  9. Near infrared spectroscopy monitoring in the pediatric cardiac catheterization laboratory.

    Science.gov (United States)

    Tanidir, Ibrahim Cansaran; Ozturk, Erkut; Ozyilmaz, Isa; Saygi, Murat; Kiplapinar, Neslihan; Haydin, Sertac; Guzeltas, Alper; Odemis, Ender

    2014-10-01

    Near-infrared spectroscopy (NIRS) is a noninvasive method used to evaluate tissue oxygenation. We evaluated the relationship between cerebral and renal NIRS parameters during transcatheter intervention and adverse events in the catheterization room. Between January 1 and May 31, 2012, 123 of 163 pediatric patients undergoing cardiac catheterization were followed by NIRS. All were monitored by electrocardiography, noninvasive blood pressure measurement, pulse oxymetry, initial and final blood lactate level measurement. The number of interventional procedures was 73 (59%). During the procedures, 39 patients experienced a total of 41 adverse events: 18 (19.5%) had desaturation, 10 (8.1%) arrhythmia, three (2.4%) had respiratory difficulty, six (4.8%) had a situation calling for cardiopulmonary resuscitation, three (2.4%) had anemia necessitating transfusion, and one (0.8%) had a cyanotic spell. Cranial NIRS values worsened in 12 (9.8%) and renal measurements worsened in 13 (12.5%) patients. The sensitivity and specificity of a 9% impairment of cranial values were 90 and 61%, respectively, while the corresponding calculations for a 21% fall in renal measurements were 54% sensitivity and 90% specificity. When arrhythmia developed, NIRS values fell simultaneously, while the development of a desaturation problem was heralded by NIRS falling 10-15 s earlier than changes in pulse oxymetry; on improving saturation, NIRS returned to earlier values 10-15 s before pulse oxymetry readings. NIRS monitoring may provide an early warning with regard to complications likely to develop during a procedure. A fall of 9% in cranial NIRS values, or of 21% in renal measurements, should raise clinician awareness. PMID:24404951

  10. 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. PMID:27544104

  11. Optical properties of nanostructured tungsten in near infrared range

    International Nuclear Information System (INIS)

    In nuclear fusion devices, infrared (IR) imaging diagnostics have been widely used for the temperature measurement of in-vessel surfaces. For the diagnostics, variations of the optical emittance and reflectance of wall materials will be an essential issue to measure the temperature correctly. In this study, variations in the optical properties in near IR range of tungsten exposed to helium plasmas were experimentally investigated in detail by observing the radiation spectrum from a heated sample. By the exposure to the helium plasma, nanostructures were grown from the surface, while the nanostructures were annealed out when the surface temperature was raised without helium ion irradiation. The optical emittance was measured from the radiation spectrum in the wavelength range 1400–4000 nm; it was revealed that the emittance significantly altered for a short time period in the formation and annealing processes of nanostructures. The influence of the variation in the optical properties on the IR diagnostics is discussed. (paper)

  12. 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

  13. 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

  14. Effects of Near-Infrared Laser on Neural Cell Activity

    International Nuclear Information System (INIS)

    Near-infrared laser has been used to relieve patients from various kinds of pain caused by postherpetic neuralgesia, myofascial dysfunction, surgical and traumatic wound, cancer, and rheumatoid arthritis. Clinically, He-Ne (λ=632.8 nm, 780 nm) and Ga-Al-As (805 ± 25 nm) lasers are used to irradiate trigger points or nerve ganglion. However the precise mechanisms of such biological actions of the laser have not yet been resolved. Since laser therapy is often effective to suppress the pain caused by hyperactive excitation of sensory neurons, interactions with laser light and neural cells are suggested. As neural excitation requires large amount of energy liberated from adenosine triphosphate (ATP), we examined the effect of 830-nm laser irradiation on the energy metabolism of the rat central nervous system and isolated mitochondria from brain. The diode laser was applied for 15 min with irradiance of 4.8 W/cm2 on a 2 mm-diameter spot at the brain surface. Tissue ATP content of the irradiated area in the cerebral cortex was 19% higher than that of the non-treated area (opposite side of the cortex), whereas the ADP content showed no significant difference. Irradiation at another wavelength (652 nm) had no effect on either ATP or ADP contents. The temperature of the brain tissue was increased 4.5-5.0 deg. C during the irradiation of both 830-nm and 652-nm laser light. Direct irradiation of the mitochondrial suspension did not show any wavelength-dependent acceleration of respiration rate nor ATP synthesis. These results suggest that the increase in tissue ATP content did not result from the thermal effect, but from specific effect of the laser operated at 830 nm. Electrophysiological studies showed the hyperpolarization of membrane potential of isolated neurons and decrease in membrane resistance with irradiation of the laser, suggesting an activation of potassium channels. Intracellular ATP is reported to regulate some kinds of potassium channels. Possible mechanisms

  15. Design of camouflage material for visible and near infrared based on thin film technology

    Science.gov (United States)

    Miao, Lei; Shi, Jia-ming; Zhao, Da-peng; Liu, Hao; Wang, Chao; Xu, Yan-liang

    2015-11-01

    Visible light and near infrared based camouflage materials achieve good stealth under traditional optical detection equipment but its spectral differences with green plants can be taken advantage of by high spectrum based detection technologies. Based on the thin structure of bandpass filter, we designed an optical film with both green and near infrared spectrum. We conducted simulations using transfer matrix methods and optimized the result by simplex methods. The spectral reflectance curve of the proposed thin film matches that of green plants, and experiments show that the proposed thin film achieve good invisibility under visible light and near infrared in a wide viewing angle.

  16. Near-infrared photodetectors utilizing MoS2-based heterojunctions

    International Nuclear Information System (INIS)

    Near-infrared photodetectors are developed using graphene/MoS2 and WSe2/MoS2 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−1 for the graphene/MoS2 and WSe2/MoS2 heterojunctions, respectively, which are much higher than the photoresponsibility reported for a multilayer MoS2 phototransistor

  17. 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

  18. Near infrared spectroscopy--investigations in neurovascular diseases.

    Science.gov (United States)

    Schytz, Henrik Winther

    2015-12-01

    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 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 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, but this requires an acceptable LFOs variation between hemispheres and over time in the healthy brain. The second study therefore investigated day-to-day and hemispheric variations in LFOs with NIRS. It was shown that NIRS might be useful in assessing LFOs between hemispheres, as well as interhemispheric phase and gain directly and over time. Migraine may be associated with persistent impairment of neurovascular coupling, but there is no experimental evidence to support this. The third study therefore investigated interictal neurovascular coupling during a mental task by a Stroop test in migraine without aura (MO) patients, which is the most common type of migraine. The study showed intact neurovascular coupling in the prefrontal cortex outside of attacks in patients with MO. The fourth study aimed to investigate possible changes in LFOs amplitude following nitric oxide (NO) donor infusion in familial hemiplegic migraine (FHM), which is a rare Mendelian subtype of migraine with aura. This study showed increased LFOs amplitude only in FHM patients with co-existing common type of migraine

  19. Near-infrared emissions from Yb3+-doped CeO2 and Ce2Si2O7 films based on silicon substrates subjected to thermal treatment

    Science.gov (United States)

    Mu, Guangyao; Wang, Shenwei; Li, Ling; Yin, Xue; Huang, Miaoling; Yi, Lixin

    2016-05-01

    Photoluminescence properties of Yb3+-doped CeO2 films annealed in different atmospheres were investigated. CeO2:Yb3+ films were deposited by electron-beam evaporation technique. Near-infrared emission around 970 nm was observed after annealing the films both in air and in Ar-H2 atmosphere, which is attributed to the Yb3+:2F5/2 → 2F7/2 transition. Optimization of the Yb3+ concentration for the 970 nm luminescence yield was also investigated. Characterized by different methods, Ce2Si2O7 was formed in the films annealed in reducing atmosphere, which was expected to be more applicable for the silicon-based optoelectronic applications.

  20. Variable selection in near-infrared spectroscopy: Benchmarking of feature selection methods on biodiesel data

    International Nuclear Information System (INIS)

    During the past several years, near-infrared (near-IR/NIR) spectroscopy has increasingly been adopted as an analytical tool in various fields from petroleum to biomedical sectors. The NIR spectrum (above 4000 cm-1) of a sample is typically measured by modern instruments at a few hundred of wavelengths. Recently, considerable effort has been directed towards developing procedures to identify variables (wavelengths) that contribute useful information. Variable selection (VS) or feature selection, also called frequency selection or wavelength selection, is a critical step in data analysis for vibrational spectroscopy (infrared, Raman, or NIRS). In this paper, we compare the performance of 16 different feature selection methods for the prediction of properties of biodiesel fuel, including density, viscosity, methanol content, and water concentration. The feature selection algorithms tested include stepwise multiple linear regression (MLR-step), interval partial least squares regression (iPLS), backward iPLS (BiPLS), forward iPLS (FiPLS), moving window partial least squares regression (MWPLS), (modified) changeable size moving window partial least squares (CSMWPLS/MCSMWPLSR), searching combination moving window partial least squares (SCMWPLS), successive projections algorithm (SPA), uninformative variable elimination (UVE, including UVE-SPA), simulated annealing (SA), back-propagation artificial neural networks (BP-ANN), Kohonen artificial neural network (K-ANN), and genetic algorithms (GAs, including GA-iPLS). Two linear techniques for calibration model building, namely multiple linear regression (MLR) and partial least squares regression/projection to latent structures (PLS/PLSR), are used for the evaluation of biofuel properties. A comparison with a non-linear calibration model, artificial neural networks (ANN-MLP), is also provided. Discussion of gasoline, ethanol-gasoline (bioethanol), and diesel fuel data is presented. The results of other spectroscopic techniques

  1. Design and development of SiGe based near-infrared photodetectors

    Science.gov (United States)

    Zeller, John W.; Puri, Yash R.; Sood, Ashok K.; McMahon, Shane; Efsthadiatis, Harry; Haldar, Pradeep; Dhar, Nibir K.

    2014-10-01

    Near-infrared (NIR) sensors operating at room temperatures are critical for a variety of commercial and military applications including detecting mortar fire and muzzle flashes. SiGe technology offers a low-cost alternative to conventional IR sensor technologies such as InGaAs, InSb, and HgCdTe for developing NIR micro-sensors that will not require any cooling and can operate with high bandwidths and comparatively low dark currents. Since Ge has a larger thermal expansion coefficient than Si, tensile strain may be incorporated into detector devices during the growth process, enabling an extended operating wavelength range above 1600 nm. SiGe based pin photodetectors have advantages of high stability, low noise, and high responsivity compared to metal-semiconductor-metal (MSM) devices. We have developed a process flow and are fabricating SiGe detector devices on 12" (300 mm) silicon wafers in order to take advantage of high throughput, large-area leading-edge silicon based CMOS technology that provides small feature sizes with associated device cost/density scaling advantages. The fabrication of the detector devices is facilitated by a two-step growth process incorporating initial low temperature growth of Ge/SiGe to form a thin strain-relaxed layer, followed by high temperature growth to deposit a thicker absorbing film, and subsequent high temperature anneal. This growth process is designed to effectively reduce dark current and enhance detector performance by reducing the number of defects and threading dislocations which form recombination centers during the growth process. Various characterization techniques have been employed to determine the properties of the epitaxially deposited Ge/SiGe layers, and the corresponding results are discussed.

  2. 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...

  3. Enhanced broadband near-infrared luminescence of Bi-doped oxyfluoride glasses.

    Science.gov (United States)

    Xu, Beibei; Tan, Dezhi; Zhou, Shifeng; Hong, Zhanglian; Sharafudeen, Kaniyarakkal N; Qiu, Jianrong

    2012-12-17

    Broadband near-infrared luminescence covering 900 to 1600 nm has been observed in Bi-doped oxyfluoride silicate glasses. The partial substitution of fluoride for oxide in Bi-doped silicate glasses leads to an increase of the intensity and lifetime of the near-infrared luminescence and blue-shift of the near-infrared emission peaks. Both Bi-doped silicate and oxyfluoride silicate glasses show visible luminescence with blue, green, orange and red emission bands when excited by ultra-violet light. Careful investigation on the luminescence properties indicates that the change of near-infrared luminescence is related to optical basicity, phonon energy of the glass matrix and crystal field around Bi active centers. These results offer a valuable way to control the luminescence properties of Bi-doped materials and may find some applications in fiber amplifier and fiber laser. PMID:23263148

  4. Near-Infrared spectroscopy of the possible nova candidate PNV J17355050-2934240

    Science.gov (United States)

    Srivastava, Mudit; Joshi, Vishal; Banerjee, D. P. K.; Ashok, N. M.

    2016-03-01

    We report near-infrared observations of PNV J17355050-2934240 which has been reported as a possible nova candidate in the CBAT TOCP site (http://www.cbat.eps.harvard.edu/unconf/followups/J17355050-2934240.html).

  5. 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...

  6. 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.

  7. Near infrared fluorescent chlorophyll nanoscale liposomes for sentinel lymph node mapping

    OpenAIRE

    Fan L; Wu Q; Chu M

    2012-01-01

    Lina Fan,1,* Qiang Wu,1,* Maoquan Chu1,21School of Life Science and Technology, 2The Institute for Advanced Materials and Nano Biomedicine Tongji University, Shanghai, People's Republic of China *These authors contributed equally to this workBackground: Sentinel lymph node (SLN) mapping using in vivo near infrared fluorescence imaging has attracted great attention during the past few years. Here we report on the early use of poorly water-soluble chlorophyll with near infrared fluoresc...

  8. The impact of SCIAMACHY near-infrared instrument calibration on CH4 and CO total columns

    OpenAIRE

    Gloudemans, A. M. S.; Schrijver, H.; Kleipool, Q.; Broek, M. M. P.; A. G. Straume; Lichtenberg, G.; Van Hees, R. M.; Aben, I.; Meirink, J. F.

    2005-01-01

    The near-infrared spectra measured with the SCIAMACHY instrument on board the ENVISAT satellite suffer from several instrument calibration problems. The effects of three important instrument calibration issues on the retrieved methane (CH4) and carbon monoxide (CO) total columns have been investigated: the effects of the growing ice layer on the near-infrared detectors, the effects of the orbital variation of the instrument dark signal, and the effects of the dead/bad ...

  9. Low loss liquid crystal photonic bandgap fiber in the near-infrared region

    DEFF Research Database (Denmark)

    Scolari, Lara; Wei, Lei; Gauza, S.;

    2010-01-01

    We infiltrate a photonic crystal fiber with a perdeuterated liquid crystal, which has a reduced infrared absorption. The lowest loss ever reported (about 1 dB) in the middle of the near-infrared bandgap is achieved.......We infiltrate a photonic crystal fiber with a perdeuterated liquid crystal, which has a reduced infrared absorption. The lowest loss ever reported (about 1 dB) in the middle of the near-infrared bandgap is achieved....

  10. Characterisation of polymeric rod-connected diamond photonic crystal at near-infrared range

    OpenAIRE

    Chen, L; Taverne, M.P.C.; X. Zheng; Huang, C. C.; Garcia, Y.L.; Hewak, D.W.; Rarity, J.G.

    2015-01-01

    We present a low-index polymeric three-dimensional photonic crystal, rod-connected diamond structure, created via direct laser writing, showing a partial photonic band gap at near-infrared wavelengths in both P and S polarization, measured by angular resolved Fourier image spectroscopy. We show initial tests of backfilling with high refractive index material aimed at achieving a full photonic bandgap in the near-infrared.

  11. Functional near-infrared spectroscopy of the neonatal brain: Instrumentation, methods and experiments

    OpenAIRE

    Kotilahti, Kalle

    2015-01-01

    Near-infrared spectroscopy (NIRS) is a noninvasive medical technology that uses visible red and near-infrared light to probe changes in the concentrations of absorbers in tissue. In functional NIRS (fNIRS), local hemoglobin concentration changes in brain are measured, which can be interpreted as changes in cerebral blood flow and volume, and are related to neuronal activation. NIRS is an especially suitable imaging modality for neonates as the instrumentation is safe, portable and silent comp...

  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. A route to brightly fluorescent carbon nanotubes for near-infrared imaging in mice

    OpenAIRE

    Welsher, Kevin; Liu, Zhuang; Sarah P Sherlock; Robinson, Joshua Tucker; Chen, Zhuo; Daranciang, Dan; Dai, Hongjie

    2009-01-01

    The near-infrared photoluminescence intrinsic to semiconducting single-walled carbon nanotubes is ideal for biological imaging owing to the low autofluorescence and deep tissue penetration in the near-infrared region beyond 1 µm. However, biocompatible single-walled carbon nanotubes with high quantum yield have been elusive. Here, we show that sonicating single-walled carbon nanotubes with sodium cholate, followed by surfactant exchange to form phospholipid–polyethylene glycol coated nanotube...

  14. Polymeric near-infrared absorbing dendritic nanogels for efficient in vivo photothermal cancer therapy

    Science.gov (United States)

    Molina, Maria; Wedepohl, Stefanie; Calderón, Marcelo

    2016-03-01

    In recent years, several near-infrared light absorbing inorganic nanomaterials have been developed for photothermal therapy. However, their biological fate after injection limits their clinical utilization. In this work, we developed a novel polymeric near-infrared light absorbing material based on a biocompatible thermoresponsive nanogel that is semi-interpenetrated with polyaniline, a conjugated polymer with strong near-infrared absorbance. This polymeric nanocomposite generates heat after being irradiated by NIR light, thereby inducing a local hyperthermia that is used for photothermal cancer therapy in vitro and in vivo.In recent years, several near-infrared light absorbing inorganic nanomaterials have been developed for photothermal therapy. However, their biological fate after injection limits their clinical utilization. In this work, we developed a novel polymeric near-infrared light absorbing material based on a biocompatible thermoresponsive nanogel that is semi-interpenetrated with polyaniline, a conjugated polymer with strong near-infrared absorbance. This polymeric nanocomposite generates heat after being irradiated by NIR light, thereby inducing a local hyperthermia that is used for photothermal cancer therapy in vitro and in vivo. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07587d

  15. Preparation and near-infrared absorption of nano-SnO2/SiO2 assemblies with doping and without doping

    International Nuclear Information System (INIS)

    The assemblies of nano-SnO2/SiO2 and Sb- or Pd-doped nano-SnO2/SiO2, in which the nano-SnO2 particles are located in the pores of mesoporous SiO2 dry gels, were synthesized. Only for the Sb-doped nano-SnO2/SiO2 assemblies, a broad near-infrared absorption step occurs in the optical absorption spectrum of the wavelength range from 300 to 1500 nm. The near-infrared absorption phenomenon is attributed to electronic transitions from the ground states to the excitation states of the impurity energy levels, which are formed by Sb doping in SnO2. With increasing the weight ratio of SnO2:SiO2 or the annealing temperature, the near-infrared absorption step slope side exhibits 'red shift', which is caused by the quantum confinement effect weakening due to the increased SnO2 crystalline diameter.

  16. Er-doped lead borate glasses and transparent glass ceramics for near-infrared luminescence and up-conversion applications.

    Science.gov (United States)

    Pisarski, Wojciech A; Goryczka, Tomasz; Pisarska, Joanna; Ryba-Romanowski, Witold

    2007-03-15

    Lead borate based glasses have been analyzed using Raman and infrared spectroscopy. The formation of different borate groups and the direction of BO3 BO4 conversion strongly depends on the PbO- and/or PbF2-to-B2O3 ratio in chemical composition. PbF2-PbO-B2O3 based glasses containing Er3+ ions have been studied after annealing. The orthorhombic PbF2 crystallites are formed during thermal treatment, which was evidenced by X-ray diffraction analysis. Near-infrared luminescence at 1530 nm and green up-conversion at 545 nm have been registered for samples before and after annealing. The luminescence bands correspond to 4I13/2-4I15/2 and 4S3/2-4I15/2 transitions of Er3+ ions, respectively. In comparison to the precursor glasses, the luminescence intensities are higher in the studied transparent oxyfluoride glass ceramics. Simultaneously, the half-width of the luminescence lines slightly decreases. It can be the evidence that a small amount of the Er3+ ions is incorporated into the orthorhombic PbF2 phase. PMID:17302452

  17. Application research on enhancing near-infrared micro-imaging quality by 2nd derivative

    Science.gov (United States)

    Wang, Dong; Ma, Zhi-hong; Zhao, Liu; Wang, Bei-hong; Han, Ping; Pan, Li-gang; Wang, Ji-hua

    2013-08-01

    Near-infrared micro-imaging will not only provide the sample's spatial distribution information, but also the spectroscopic information of each pixel. In this thesis, it took the artificial sample of wheat flour and formaldehyde sodium sulfoxylate distribution given for example to research the data processing method for enhancing the quality of near-infrared micro-imaging. Near-infrared spectroscopic feature of wheat flour and formaldehyde sodium sulfoxylate being studied on, compare correlation imaging and 2nd derivative imaging were applied in the imaging processing of the near-infrared micro-image of the artificial sample. Furthermore, the two methods were combined, i.e. 2nd derivative compare correlation imaging was acquired. The result indicated that the difference of the correlation coefficients between the two substances, i.e. wheat flour and formaldehyde sodium sulfoxylate, and the reference spectrum has been increased from 0.001 in compare correlation image to 0.796 in 2nd derivative compare correlation image respectively, which enhances the imaging quality efficiently. This study will, to some extent, be of important reference significance to near-infrared micro-imaging method research of agricultural products and foods.

  18. 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.

  19. Radiation damage in zircon and monazite

    International Nuclear Information System (INIS)

    Monazite and zircon respond differently to ion irradiation and to thermal and irradiation-enhanced annealing. The damage process (i.e., elastic interactions leading to amorphization) in radioactive minerals (metamictization) is basically the same as for the ion-beam-irradiated samples with the exception of the dose rate which is much lower in the case of natural samples. The crystalline-to-metamict transition in natural samples with different degrees of damage, from almost fully crystalline to completely metamict, is compared to the sequence of microstructures observed for ion-beam-irradiated monazite and zircon. The damage accumulation process, representing the competing effects of radiation-induced structural disorder and subsequent annealing mechanisms (irradiation-enhanced and thermal) occurs at much higher temperatures for zircon than for monazite. The amorphization dose, expressed as displacements per atom, is considerably higher in the natural samples, and the atomic-scale process leading to metamictization appears to develop differently. Ion-beam-induced amorphization data were used to calculate the α-decay-event dose required for amorphization in terms of a critical radionuclide concentration, i.e., the concentration above which a sample of a given age will become metamict at a specific temperature. This equation was applied to estimate the reliability of U-Pb ages, to provide a qualitative estimate of the thermal history of high-U natural zircons, and to predict whether actinide-bearing zircon or monazite nuclear waste forms will become amorphous (metamict) over long timescales

  20. Broadband near-infrared luminescence in gamma-irradiated Bi-doped alpha-BaB(2)O(4) single crystals.

    Science.gov (United States)

    Su, Liangbi; Yu, Jun; Zhou, Peng; Li, Hongjun; Zheng, Lihe; Yang, Yan; Wu, Feng; Xia, Haiping; Xu, Jun

    2009-08-15

    Spectroscopic properties of as-grown and gamma-irradiated undoped and Bi-doped alpha-BBO (BaB(2)O(4)) single crystals were investigated. Bi(2+) and color centers in Bi:alpha-BBO crystals were investigated to be nonluminescent in the near-infrared (NIR) region. Broadband NIR luminescence at 1139 nm with a FWHM of 108 nm and a decay time of 526 mus was realized in Bi:alpha-BBO crystal through gamma irradiation. Bi(+) was attributed to be responsible for the NIR emission, which can be bleached by thermal annealing. The involved physical processes in Bi:alpha-BBO crystal during the courses of irradiation and heat annealing were tentatively established. PMID:19684830

  1. Thermal loading induced near-infrared broadband upconversion emission of Sm3+-doped β-NaYbF4 nano-phosphors

    International Nuclear Information System (INIS)

    A non-closed hydrothermal synthetic processing is improved to synthesize Sm3+ doped β-NaYbF4 nano-phosphors at 98 deg. C without any high-temperature and high-pressure treatments as a final step. Novel green, red, and near-infrared broadband (799-873 nm) upconversion emissions of Sm3+-doped β-NaYbF4 nano-phosphors under 980 nm excitation are observed. These UC emissions can be assigned to the Sm3+ transitions of 4GJ, 4F3/2 and 6F11/2→6HJ. The half-width of 873 nm emission band is broadened nearly two-fold through the annealing treatment for nano-phosphors. The upconversion process in Yb3+-Sm3+ system is discussed based on energy transfer mechanisms. - Highlights: → Sm3+ doped β-NaYbF4 nano-phosphors were synthesized by non-closed hydrothermal synthetic processing at 98 deg. C. → Novel green, red, and near-infrared broadband upconversion emissions of Sm3+ are observed under 980 nm excitation. → Half-width of 873 nm emission band is broadened nearly two-fold through the annealing treatment for nano-phosphors. → Cooperative sensitization and phonon-assisted energy transfer process by the thermal loading mechanisms is discussed.

  2. 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.

  3. Nanostructured thin film-based near-infrared tunable perfect absorber using phase-change material

    Science.gov (United States)

    Kocer, Hasan

    2015-01-01

    Nanostructured thin film absorbers embedded with phase-change thermochromic material can provide a large level of absorption tunability in the near-infrared region. Vanadium dioxide was employed as the phase-change material in the designed structures. The optical absorption properties of the designed structures with respect to the geometric and material parameters were systematically investigated using finite-difference time-domain computations. Absorption level of the resonance wavelength in the near-IR region was tuned from the perfect absorption level to a low level (17%) with a high positive dynamic range of near-infrared absorption intensity tunability (83%). Due to the phase transition of vanadium dioxide, the resonance at the near-infrared region is being turned on and turned off actively and reversibly under the thermal bias, thereby rendering these nanostructures suitable for infrared camouflage, emitters, and sensors.

  4. The GRAPHENE-SiC Substrate Interaction Enhanced Near-Infrared Absorption

    Science.gov (United States)

    Xu, X. G.; Yin, R.; Xu, G. J.; Cao, J. C.

    When epitaxially grown on silicon carbide, a single layer graphene will exhibit a finite energy bandgap like a conventional semiconductor, and its energy dispersion is no longer linear in momentum space in the low energy regime. In this paper, we present a quantitative analysis on the effect of the SiC substrate in the optical absorption of π-electrons in graphene. We calculated the absorption matrix element and the optical absorption in the near infrared even to the visible region by taking into account the SiC substrate effect. It has been found that the substrate effect can significantly enhance the optical absorption in graphene in the near-infrared region, even by up to 90%. It may be helpful to eliminate the previous discrepancy of optical transmission between the theoretical results and the experimental results in the near-infrared to the visible region.

  5. 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.

  6. Low-cost near-infrared imaging device for inspection of historical manuscripts

    International Nuclear Information System (INIS)

    Near-infrared (NIR) or sometimes called black light is a waveform beyond visible light and it is not detectable by human eyes. However electronic sensors such as the type used in digital cameras are able to detect signals in the infrared band. To avoid distortion in the pictures obtained near-infrared is blocked by optical filters inserted in digital cameras. By carrying out minor modification allowing near-infrared signal to be imaged while blocking the visible signal, the camera is turned into a low-cost NIR imaging instrument. NIR imaging can be a useful tool in historical manuscript study or restoration. A few applications have been successfully demonstrated in laboratory experiment using the instrument available in MINT. However, due to unavailability of historical items, easily available texts and paintings are used in the demonstrations. This paper reports achievements of early work on the application of digital camera in the detection of damaged prints or writings. (Author)

  7. An Optical Computed Tomography by Means of the Simplified Collimator in Near-infrared Region

    Science.gov (United States)

    Mizumoto, Iwao; Odake, Sotoji; Mashiko, Shinro; Suzuki, Nobutaka

    The optical CT unit which was assembled with the laser diode working at the wavelength of 1.3 μm, and a glass optical fiber and a pin-hole with a diameter of the 100 μm yields the collimated near-infrared light through a scattering medium. Because the spatial collimator system needs no fast response time, a high sensitive Ge-PIN photodetector was employed the CT system. The optical CT image is allowed by use of near-infrared absorption characteristic. When the image construction of a grape was performed using projection data, so the comparatively good experimental results was obtained. The places of a grape seed was found without cutting. By means of the difference in characteristics of near-infrared absorption, the image of a cylindrical oil phantom in gelatin was reproduced.

  8. 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...

  9. Near infrared fluorescent chlorophyll nanoscale liposomes for sentinel lymph node mapping

    Directory of Open Access Journals (Sweden)

    Fan L

    2012-06-01

    Full Text Available Lina Fan,1,* Qiang Wu,1,* Maoquan Chu1,21School of Life Science and Technology, 2The Institute for Advanced Materials and Nano Biomedicine Tongji University, Shanghai, People's Republic of China *These authors contributed equally to this workBackground: Sentinel lymph node (SLN mapping using in vivo near infrared fluorescence imaging has attracted great attention during the past few years. Here we report on the early use of poorly water-soluble chlorophyll with near infrared fluorescence extracted from the leaf of Chimonanthus salicifolius, for mouse axillary SLN mapping.Methods and results: To improve the water solubility and SLN targeting of the chlorophyll, we encapsulated the chlorophyll in nanoscale liposomes. The liposome-coated chlorophyll nanocomposites obtained were spherical in shape and had an average diameter of 21.7 ± 6.0 nm. The nanocomposites dispersed well in water, and in aqueous suspension they exhibited brighter near infrared fluorescence than chlorophyll alone. After incubation of the nanocomposites with normal liver cells (QSG-7701 and macrophage cells (Ana-1 for no more than 48 hours, there was no obvious reduction in cell viability. When the nanocomposites were injected intradermally into the paw of a mouse, the axillary SLN was found to be strongly fluorescent and was easily visualized in real time without a requirement for surgery. The intensity of the near infrared fluorescence emitted by the SLN was obviously brighter than that emitted by the SLN of another mouse that had been intradermally injected with chlorophyll alone.Conclusion: Our data show that the liposome-coated chlorophyll nanocomposites could have great potential for clinical SLN mapping due to their lack of toxicity, bright near infrared fluorescence, and small diameter.Keywords: chlorophyll, liposomes, nanocomposites, near infrared fluorescence, sentinel lymph node mapping

  10. Near-Infrared Imaging of Barred Halo Dominated Low Surface Brightness Galaxies

    OpenAIRE

    Honey, M.; Das, M.; Ninan, J. P.; Purvankara, M.

    2016-01-01

    We present a near-infrared (NIR) imaging study of barred low surface brightness (LSB) galaxies using the TIFR near-infrared Spectrometer and Imager (TIRSPEC). LSB galaxies are dark matter dominated, late type spirals that have low luminosity stellar disks but large neutral hydrogen (HI) gas disks. Using SDSS images of a very large sample of LSB galaxies derived from the literature, we found that the barred fraction is only 8.3%. We imaged twenty five barred LSB galaxies in the J, H, K$_S$ wav...

  11. Near-infrared spiroximetry: noninvasive measurements of venous saturation in piglets and human subjects

    OpenAIRE

    Franceschini, Maria Angela; Boas, David A.; ZOURABIAN, ANNA; Diamond, Solomon G.; NADGIR, SHALINI; Lin, David W.; Moore, John B.; Fantini, Sergio

    2002-01-01

    We present a noninvasive method to measure the venous oxygen saturation (SvO2) in tissues using near-infrared spectroscopy (NIRS). This method is based on the respiration-induced oscillations of the near-infrared absorption in tissues, and we call it spiroximetry (the prefix spiro means respiration). We have tested this method in three piglets (hind leg) and in eight human subjects (vastus medialis and vastus lateralis muscles). In the piglet study, we compared our NIRS measurements of the Sv...

  12. [Application of near-infrared diffuse reflectance spectroscopy to the detection and identification of transgenic corn].

    Science.gov (United States)

    Rui, Yu-kui; Luo, Yun-bo; Huang, Kun-lun; Wang, Wei-min; Zhang, Lu-da

    2005-10-01

    With the rapid development of the GMO, more and more GMO food has been pouring into the market. Much attention has been paid to GMO labeling under the controversy of GMO safety. Transgenic corns and their parents were scanned by continuous wave of near infrared diffuse reflectance spectroscopy range of 12000-4000 cm(-1); the resolution was 4 cm(-1); scanning was carried out for 64 times; BP algorithm was applied for data processing. The GMO food was easily resolved. Near-infrared diffuse reflectance spectroscopy is unpolluted and inexpensive compared with PCR and ELISA, so it is a very promising detection method for GMO food. PMID:16395887

  13. Generation and performance of automated jarosite mineral detectors for visible/near-infrared spectrometers at Mars

    Science.gov (United States)

    Gilmore, Martha S.; Bornstein, Benjamin; Merrill, Matthew D.; Castaño, Rebecca; Greenwood, James P.

    2008-05-01

    We have developed two automated detectors that can recognize the sulfate mineral jarosite in unknown visible to near-infrared spectra (350-2500 nm). The two detectors are optimized for use within the terrestrial and martian atmospheres. The detectors are built from Support Vector Machines trained using a generative model to create linear mixtures of library mineral spectra. Both detectors performed with an average ˜90% accuracy on laboratory spectra of single minerals and the laboratory and field spectra of rocks collected in a hydrothermal environment. This type of algorithm will contribute to the efficiency of onboard data analysis of landed and orbital visible/near-infrared spectrometers at Mars.

  14. The Development of Novel Near-Infrared (NIR Tetraarylazadipyrromethene Fluorescent Dyes

    Directory of Open Access Journals (Sweden)

    Young-Tae Chang

    2013-05-01

    Full Text Available Novel structures of an near-infrared (NIR tetraarylazadipyrromethene (aza-BODIPY series have been prepared. We designed the core structure containing two amido groups at the para-position of the aromatic rings. The amido group was incorporated to secure insensitivity to pH and to ensure a bathochromic shift to the NIR region. Forty members of aza-BODIPY compounds were synthesized by substitution of the acetyl group with commercial amines on the alpha bromide. The physicochemical properties and photostability were investigated and the fluorescence emission maxima (745~755 nm were found to be in the near infrared (NIR range of fluorescence.

  15. Deep near-infrared observations of W3 Main star forming region

    OpenAIRE

    Ojha, D. K.; Tamura, M.; Nakajima, Y; Fukagawa, M.; Sugitani ,K, Mimura, K, Takeuchi, M, Lepot, K, & Javaux E.J; Nagashima, C.; Nagayama, T.; Nagata, T.; Sato, S.; Pickles, A. J.; Ogura, K.

    2004-01-01

    We present a deep JHKs-band imaging survey of the W3 Main star forming region, using the near-infrared camera, SIRIUS, mounted on the University of Hawaii 2.2m telescope. The near-infrared survey covers an area of ~ 24 sq. arcmin with 10 sigma limiting magnitudes of ~ 19.0, 18.1, and 17.3 in J, H, and Ks-band, respectively. We construct JHK color-color and J/J-H and K/H-K color-magnitude diagrams to identify young stellar objects and estimate their masses. Based on these color-color and color...

  16. Simultaneous optical and near-infrared linear spectropolarimetry of the earthshine

    OpenAIRE

    Miles-Páez, P. A.; Pallé, E.; Osorio, M. R. Zapatero

    2014-01-01

    Aims: We aim to extend our current observational understanding of the integrated planet Earth spectropolarimetry from the optical to the near-infrared wavelengths. Major biomarkers like O$_{\\rm 2}$ and water vapor are strong flux absorbents in the Earth atmosphere and some linear polarization of the reflected stellar light is expected to occur at these wavelengths. Methods: Simultaneous optical ($0.4-0.9$ $\\mu$m) and near-infrared ($0.9-2.3$ $\\mu$m) linear spectropolarimetric data of the eart...

  17. Near infrared spectra of galactic and magellanic Wolf-Rayet stars

    International Nuclear Information System (INIS)

    The first part of this paper presents near infrared spectra (λ 6150 - λ 10350 Angstroms) of galactic and mainly Magellanic Wolf Rayet Stars. The spectra are compared to the ones published previously in the Catalogue of near infrared spectra of southern galactic WR stars and some peculiarities are pointed out. In the second part, the hydrogen signature in the Paschen series is discussed. For all the galactic and Magellanic objects in which such a signature could be quantified, a value of the H+ / He++ ratio has been derived and compared to previous estimations based on the Balmer series

  18. Comparative effectiveness of light emitting diodes (LEDs) and Lasers in near infrared photoimmunotherapy

    OpenAIRE

    Sato, Kazuhide; Watanabe, Rira; Hanaoka, Hirofumi; Nakajima, Takahito; Peter L. Choyke; Kobayashi, Hisataka

    2016-01-01

    Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with the toxicity induced by photosensitizers after exposure to near infrared (NIR) light. Herein we compare two NIR-light sources; light emitting diodes (LEDs) and Lasers, for their effectiveness in NIR-PIT. A photosensitizer, IRDye-700DX, conjugated to panitumumab (pan-IR700), was incubated with EGFR-expressing A431 and MDA-MB-468-luc cells. NIR-light was pro...

  19. Negative refraction in Al:ZnO/ZnO metamaterial in the near-infrared

    CERN Document Server

    Naik, Gururaj V; Kildishev, Alexander V; Shalaev, Vladimir M; Boltasseva, Alexandra

    2011-01-01

    Noble metals such as gold and silver are the primary metallic building blocks of metamaterial devices. Making subwavelength-sized structural elements from these metals seriously limits the optical performance of a device, however, and complicates the manufacturing process of nearly all metamaterial devices in the optical wavelength range. As an alternative to noble metals, we propose to use heavily-doped oxide semiconductors that offer both functional and fabrication advantages in the near-infrared. In this letter, we report an experimental demonstration of negative refraction in a near-infrared metamaterial device that is designed and fabricated using aluminum-doped zinc oxide.

  20. Near-Infrared Properties of Metal-poor Globular Clusters in the Galactic Bulge Direction

    OpenAIRE

    Chun, S. -H.; Kim, J. -W.; Shin, I. -G.; Chung, C.; Lim, D. -W.; Park, J. -H.; Kim, H. -I.; Han, W.; Sohn, Y. -J.

    2010-01-01

    Aims. J, H, and K' images obtained from the near-infrared imager CFHTIR on the Canada-France-Hawaii Telescope are used to derive the morphological parameters of the red giant branch (RGB) in the near-infrared color-magnitude diagrams for 12 metal-poor globular clusters in the Galactic bulge direction. Using the compiled data set of the RGB parameters for the observed 12 clusters, in addition to the previously studied 5 clusters, we discuss the properties of the RGB morphology for the clusters...

  1. Metamictization of zircon: Raman spectroscopic study

    International Nuclear Information System (INIS)

    Raman spectroscopy of radiation-damaged natural zircon samples shows increased line broadening and shifts of phonon frequencies with increasing radiation dose. Stretching and bending frequencies of SiO4 tetrahedra soften dramatically with increasing radiation damage. The frequency shifts can be used to determine the degree of radiation damage. Broad spectral bands related to Si-O stretching vibrations between 900 and 1000 cm-1 were observed in metamict/amorphous zircon. The radiation-dose-independent spectral profiles and the coexistence of this broad background and relative sharp Raman modes in partially damaged samples indicate that these bands are correlated with amorphous domains in zircon. The spectral profiles of metamict zircon suggest that in comparison with silica, the SiO4 tetrahedra are less polymerized in metamict zircon. This study also shows that ZrO2 and SiO2 are not the principal products of metamictization in zircon. No indication of bulk chemical unmixing of zircon into ZrO2 and SiO2 was found in 26 samples with a large variation of radiation damage (maximum dose: 23.5x1018 α-events g-1). Only one sample showed clearly, in all measured sample areas, extra sharp lines at 146, 260, 312, 460 and 642 cm-1 characteristic of tetragonal ZrO2. The geological (and possibly artificial heating) history of this sample is not known. It is concluded that radiation damage without subsequent high temperature annealing does not cause unmixing of zircon into constituent oxides. (author)

  2. Large-Area Metasurface Perfect Absorbers from Visible to Near-Infrared.

    Science.gov (United States)

    Akselrod, Gleb M; Huang, Jiani; Hoang, Thang B; Bowen, Patrick T; Su, Logan; Smith, David R; Mikkelsen, Maiken H

    2015-12-22

    An absorptive metasurface based on film-coupled colloidal silver nanocubes is demonstrated. The metasurfaces are fabricated using simple dip-coating methods and can be deposited over large areas and on arbitrarily shaped objects. The surfaces show nearly complete absorption, good off-angle performance, and the resonance can be tuned from the visible to the near-infrared. PMID:26549512

  3. Towards a Low-Cost Mobile Subcutaneous Vein Detection Solution Using Near-Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Simon Juric

    2014-01-01

    Full Text Available Excessive venipunctures are both time- and resource-consuming events, which cause anxiety, pain, and distress in patients, or can lead to severe harmful injuries. We propose a low-cost mobile health solution for subcutaneous vein detection using near-infrared spectroscopy, along with an assessment of the current state of the art in this field. The first objective of this study was to get a deeper overview of the research topic, through the initial team discussions and a detailed literature review (using both academic and grey literature. The second objective, that is, identifying the commercial systems employing near-infrared spectroscopy, was conducted using the PubMed database. The goal of the third objective was to identify and evaluate (using the IEEE Xplore database the research efforts in the field of low-cost near-infrared imaging in general, as a basis for the conceptual model of the upcoming prototype. Although the reviewed commercial devices have demonstrated usefulness and value for peripheral veins visualization, other evaluated clinical outcomes are less conclusive. Previous studies regarding low-cost near-infrared systems demonstrated the general feasibility of developing cost-effective vein detection systems; however, their limitations are restricting their applicability to clinical practice. Finally, based on the current findings, we outline the future research direction.

  4. Visible/near-infrared spectroscopy for discrimination of HLB-infected citrus leaves from healthy leaves

    Science.gov (United States)

    Researchers have used various hyperspectral systems, covering several areas of the electromagnetic spectrum to investigate all types of disease/plant interactions. The purpose of this research was to investigate using visible and near-infrared (400-1100nm) spectroscopy to differentiate HLB infected...

  5. Silica-porphyrin hybrid nanotubes for in vivo cell tracking by near-infrared fluorescence imaging.

    Science.gov (United States)

    Hayashi, Koichiro; Nakamura, Michihiro; Ishimura, Kazunori

    2012-04-21

    Near-infrared fluorescent silica-porphyrin hybrid nanotubes (HNTs) were successfully synthesized by π-π stacking, electrostatic interaction and a sol-gel reaction. The HNTs-labeled macrophages were detected in vivo, and the minimum detectable number of cells was 200. Furthermore, the biodistribution of HNTs-labeled macrophages was tracked by fluorescence imaging. PMID:22437325

  6. 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.; Sjöblom, J.; Kvalheim, O. M.

    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...

  7. Hyperspectral visible-near infrared imaging for the detection of waxed rice

    Science.gov (United States)

    Zhao, Mantong

    2014-11-01

    Presently, unscrupulous traders in the market use the industrial wax to wax the rice. The industrial wax is a particularly hazardous substance. Visible-near infrared hyperspectral images (400-1,000 nm) can be used for the detection of the waxed rice and the non-waxed rice. This study was carried out to find effective testing methods based on the visible-near infrared imaging spectrometry to detect whether the rice was waxed or not. An imaging spectroscopy system was assembled to acquire hyperspectral images from 80 grains of waxed rice and 80 grains of non-waxed rice over visible and near infrared spectral region. Spectra of 100 grains of rice were analyzed by principal component analysis (PCA) to extract the information of hyperspectral images. PCA provides an effective compressed representation of the spectral signal of each pixel in the spectral domain. We used PCA to acquire the effective wavelengths from the spectra. Based on the effective wavelengths, the predict models were set up by using partial least squares (PLS) analysis and linear discriminant analysis (LDA). Also, compared with the PLS of 80% for the waxed rice and 86.7% for the non-waxed rice detection rate, LDA gives 93.3% and 96.7% detection rate. The results demonstrated that the LDA could detect the waxed rice better, while illustrating the hyperspectral imaging technique with the visible-near infrared region could be a reliable method for the waxed rice detection.

  8. THE VARIABLE NEAR-INFRARED COUNTERPART OF THE MICROQUASAR GRS 1758–258

    Energy Technology Data Exchange (ETDEWEB)

    Luque-Escamilla, Pedro L. [Departamento de Ingeniería Mecánica y Minera, EPSJ, Universidad de Jaén, Campus Las Lagunillas s/n, A3-008, 23071 Jaén (Spain); Martí, Josep [Departamento de Física, EPSJ, Universidad de Jaén, Campus Las Lagunillas s/n, A3-420, 23071 Jaén (Spain); Muñoz-Arjonilla, Álvaro J., E-mail: peter@ujaen.es, E-mail: jmarti@ujaen.es, E-mail: ajmunoz@ujaen.es [Grupo de Investigación FQM-322, Universidad de Jaén, Campus Las Lagunillas s/n, A3-065, 23071 Jaén (Spain)

    2014-12-10

    We present a new study of the microquasar system GRS 1758–258 in the near-infrared domain based on archival observations with the Hubble Space Telescope and the NICMOS camera. In addition to confirming the near-infrared counterpart pointed out by Muñoz-Arjonilla et al., we show that this object displays significant photometric variability. From its average magnitudes, we also find that GRS 1758–258 fits well within the correlation between the optical/near-infrared and X-ray luminosity known to exist for low-mass, black-hole candidate X-ray binaries in a hard state. Moreover, the spectral energy distribution built using all radio, near-infrared, and X-ray data available closest in time to the NICMOS observations can be reasonably interpreted in terms of a self-absorbed radio jet and an irradiated accretion disk model around a stellar-mass black hole. All these facts match the expected behavior of a compact binary system and strengthen our confidence in the counterpart identification.

  9. The First Maximum-light Ultraviolet through Near-infrared Spectrum of a Type Ia Supernova

    DEFF Research Database (Denmark)

    Foley, Ryan J.; Kromer, Markus; Howie Marion, G.;

    2012-01-01

    We present the first maximum-light ultraviolet (UV) through near-infrared (NIR) Type Ia supernova (SN Ia) spectrum. This spectrum of SN 2011iv was obtained nearly simultaneously by the Hubble Space Telescope at UV/optical wavelengths and the Magellan Baade telescope at NIR wavelengths. These data...

  10. External carotid artery flow maintains near infrared spectroscopy-determined frontal lobe oxygenation during ephedrine administration

    DEFF Research Database (Denmark)

    Sørensen, H; Rasmussen, P; Sato, K;

    2014-01-01

    BACKGROUND: Phenylephrine and ephedrine affect frontal lobe oxygenation ([Formula: see text]) differently when assessed by spatially resolved near infrared spectroscopy. We evaluated the effect of phenylephrine and ephedrine on extra- vs intra-cerebral blood flow and on [Formula: see text]. METHODS...

  11. Intact neurovascular coupling during executive function in migraine without aura: interictal near-infrared spectroscopy study

    DEFF Research Database (Denmark)

    Schytz, H W; Ciftçi, K; Akin, A; Ashina, M; Bolay, H

    2010-01-01

    An altered neurovascular coupling has been proposed in migraine. We aimed to investigate neurovascular coupling during a mental task interictally in patients with migraine without aura (MO) by near-infrared spectroscopy (NIRS). Twelve migraineurs and 12 healthy controls were included. Using NIRS,...

  12. Simultaneous optical and near-infrared linear spectropolarimetry of the earthshine

    CERN Document Server

    Miles-Páez, P A; Osorio, M R Zapatero

    2014-01-01

    Aims: We aim to extend our current observational understanding of the integrated planet Earth spectropolarimetry from the optical to the near-infrared wavelengths. Major biomarkers like O$_{\\rm 2}$ and water vapor are strong flux absorbents in the Earth atmosphere and some linear polarization of the reflected stellar light is expected to occur at these wavelengths. Methods: Simultaneous optical ($0.4-0.9$ $\\mu$m) and near-infrared ($0.9-2.3$ $\\mu$m) linear spectropolarimetric data of the earthshine were acquired by observing the nightside of the waxing Moon. The data have sufficient spectral resolution (2.51 nm in the optical, and 1.83 and 2.91 nm in the near-infrared) to resolve major molecular species present in the Earth atmosphere. Results: We find the highest values of linear polarization ($\\ge 10\\%$) at the bluest wavelengths, which agrees with the literature. Linear polarization intensity steadily decreases towards red wavelengths reaching a nearly flat value beyond $\\sim$0.8 $\\mu$m. In the near-infrar...

  13. Near-infrared Single-photon-counting Detectors for Free-space Laser Receivers

    Science.gov (United States)

    Krainak, Michael A.; Sun, Xiaoli; Hasselbrack, William; Wu, Stewart; Waczynski, Augustyn; Miko, Laddawan

    2007-01-01

    We compare several photon-counting detector technologies for use as near-infrared timeresolved laser receivers in science instrument, communication and navigation systems. The key technologies are InGaAs(P) photocathode hybrid photomultiplier tubes and InGaAs(P) and HgCdTe avalanche photodiodes. We discuss recent experimental results and application.

  14. Optical and near-infrared observations of the GRB 970616 error box

    DEFF Research Database (Denmark)

    Gorosabel, J.; Castro-Tirado, A.J.; Pedersen, Henrik;

    1999-01-01

    We report on near-infrared and optical observations of the GRB 970616 error box and of the X-ray sources discovered by ASCA and ROSAT in the region. No optical transient was found either within the IPN band or in the X-ray error boxes, similarly to other bursts, and we suggest that either...

  15. Huanglongbing (Citrus Greening Detection Using Visible, Near Infrared and Thermal Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Reza Ehsani

    2013-02-01

    Full Text Available This study demonstrates the applicability of visible-near infrared and thermal imaging for detection of Huanglongbing (HLB disease in citrus trees. Visible-near infrared (440–900 nm and thermal infrared spectral reflectance data were collected from individual healthy and HLB-infected trees. Data analysis revealed that the average reflectance values of the healthy trees in the visible region were lower than those in the near infrared region, while the opposite was the case for HLB-infected trees. Moreover, 560 nm, 710 nm, and thermal band showed maximum class separability between healthy and HLB-infected groups among the evaluated visible-infrared bands. Similarly, analysis of several vegetation indices indicated that the normalized difference vegetation index (NDVI, Vogelmann red-edge index (VOG and modified red-edge simple ratio (mSR demonstrated good class separability between the two groups. Classification studies using average spectral reflectance values from the visible, near infrared, and thermal bands (13 spectral features as input features indicated that an average overall classification accuracy of about 87%, with 89% specificity and 85% sensitivity could be achieved with classification models such as support vector machine for trees with symptomatic leaves.

  16. Quantitative analysis of melamine in milk powders using near-infrared hyperspectral imaging and band ratio

    Science.gov (United States)

    Since 2008, the detection of the adulterant melamine (2,4,6-triamino-1,3,5-triazine) in food products has become the subject of research due to several food safety scares. Near-infrared (NIR) hyperspectral imaging offers great potential for food safety and quality research because it combines the fe...

  17. Targeted and Untargeted Detection of Skim Milk Powder Adulteration by Near-Infrared Spectroscopy

    NARCIS (Netherlands)

    Capuano, Edoardo; Boerrigter-Eenling, Rita; Koot, Alex; Ruth, van S.M.

    2015-01-01

    In the present study, near-infrared spectroscopy (NIRS) was explored as a fast and reliable screening method for the detection of adulteration of skim milk powder (SMP). Sixty genuine SMP were adulterated with acid whey (1–25 % w/w), starch (2 and 5 %) and maltodextrin (2 and 5 %) for a total of

  18. Use of visible and near-infrared spectroscopy to predict pork longissimus lean color stability

    Science.gov (United States)

    This study evaluated using visible and near-infrared (VIS/NIR) spectroscopy to predict lean color stability in pork loin chops. Spectra were collected immediately following and approximately 1 h after rib removal from 1,208 loins. Loins were aged for 14 d before a 2.54-cm chop was placed in simula...

  19. Spectral reflectance from plant canopies and optimum spectral channels in the near infrared

    Science.gov (United States)

    Allen, W. A.; Gausman, H. W.; Wiegand, C. L.

    1970-01-01

    Theoretical and experimental aspects of the interaction of light with a typical plant canopy are considered. Both theoretical and experimental results are used to establish optimum electromagnetic wavelength channels for remote sensing in agriculture. The spectral range considered includes half of the visible and much of the near-infrared regions.

  20. 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...... reduces the scO2. We hypothesized that norepinephrine-induced reduction in scO2 is influenced by cutaneous vasoconstriction....

  1. Design of a solid state laser for low noise upconversion detection of near infrared light

    DEFF Research Database (Denmark)

    Høgstedt, Lasse; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2015-01-01

    To maximize signal-to-noise ratio for upconversion of near-infrared light we show that the mixing intensity should be 3 GW/m2. With emphasis on the noise contribution from random duty-cycle errors the optimum design parameters is discussed....

  2. Species authentication and geographical origin discrimination of herbal medicines by near infrared spectroscopy:A review

    Institute of Scientific and Technical Information of China (English)

    Pei Wang; Zhiguo Yu

    2015-01-01

    Near infrared (NIR) spectroscopy as a rapid and nondestructive analytical technique, integrated with chemometrics, is a powerful process analytical tool for the pharmaceutical industry and is becoming an attractive complementary technique for herbal medicine analysis. This review mainly focuses on the recent applications of NIR spectroscopy in species authentication of herbal medicines and their geo-graphical origin discrimination.

  3. Investigation of vegetation history of buried chernozem soils using near-infrared spectroscopy (NIRS)

    Czech Academy of Sciences Publication Activity Database

    Vysloužilová, B.; Ertlen, D.; Šefrna, L.; Novák, T.; Virágh, K.; Rué, M.; Campaner, A.; Dreslerová, Dagmar; Schwartz, D.

    2015-01-01

    Roč. 365, 16 April (2015), s. 203-211. ISSN 1040-6182 Institutional support: RVO:67985912 Keywords : Holocene * paleopedology * paleoecology * near-infrared spectroscopy * chernozem * buried paleosol Subject RIV: DF - Soil Science Impact factor: 2.062, year: 2014

  4. Experimental characterization of dielectric-loaded plasmonic waveguide-racetrack resonators at near-infrared wavelengths

    DEFF Research Database (Denmark)

    Garcia, Cesar; Coello, Victor; Han, Zhanghua;

    2012-01-01

    Dielectric-loaded plasmonic waveguide-racetrack resonators (WRTRs) were designed and fabricated for operating at near-infrared wavelengths (750–850 nm) and characterized using leakage-radiation microscopy. The transmission spectra of the WRTRs are found experimentally and compared to the calculat...

  5. Authentication of Organic Feed by Near-Infrared Spectroscopy Combined with Chemometrics A Feasibilily Study

    NARCIS (Netherlands)

    Tres, A.; Veer, van der J.C.; Perez-Marin, M.D.; Ruth, van S.M.; Garrido-Varo, A.

    2012-01-01

    Organic products tend to retail at a higher price than their conventional counterparts, which makes them susceptible to fraud. In this study we evaluate the application of near-infrared spectroscopy (NIRS) as a rapid, cost-effective method to verify the organic identity of feed for laying hens. For

  6. A highly sensitive near-infrared luminescent metal-organic framework thermometer in the physiological range.

    Science.gov (United States)

    Zhao, Dian; Zhang, Jun; Yue, Dan; Lian, Xiusheng; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2016-07-01

    A near-infrared luminescent metal-organic framework Nd0.866Yb0.134BTB was developed as a self-calibrated thermometer in the physiological range. Its features include high sensitivity and resolution, and good biocompatibility, making such a material useful for biomedical applications. PMID:27284589

  7. Is near-infrared spectroscopy clinically useful in the preterm infant?

    DEFF Research Database (Denmark)

    da Costa, Cristine Sortica; Greisen, Gorm; Austin, Topun

    2015-01-01

    Near-infrared spectroscopy (NIRS) has been used to study cerebral haemodynamics and oxygenation in the preterm infant for many years, but its use as a clinical tool has remained elusive. This has partly been due to the challenges of providing a continuous quantitative measurement that is valid an...

  8. Feasibility of noninvasive near-infrared spectroscopy to diagnose detrusor overactivity

    NARCIS (Netherlands)

    Farag, F.; Martens, F.M.J.; Feitz, W.F.J.; Heesakkers, J.P.F.A.

    2011-01-01

    Introduction: Near-infrared spectroscopy (NIRS) is an optical technology able to detect the hemodynamic changes in biological tissues. Our objective was to determine the feasibility of applying NIRS in the noninvasive diagnosis of detrusor overactivity (DO). Patients and Methods: Comparative analysi

  9. A near-infrared study of thermally induced structural changes in polyethylene crystal

    Czech Academy of Sciences Publication Activity Database

    Watanabe, S.; Dybal, Jiří; Tashiro, K.; Ozaki, Y.

    2006-01-01

    Roč. 47, č. 6 (2006), s. 2010-2017. ISSN 0032-3861 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyethylene * near-infrared * phase transition Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.773, year: 2006

  10. Silicon based near infrared photodetector using self-assembled organic crystalline nano-pillars

    Science.gov (United States)

    Ajiki, Yoshiharu; Kan, Tetsuo; Yahiro, Masayuki; Hamada, Akiko; Adachi, Junji; Adachi, Chihaya; Matsumoto, Kiyoshi; Shimoyama, Isao

    2016-04-01

    We propose a silicon (Si) based near-infrared photodetector using self-assembled organic crystalline nano-pillars, which were formed on an n-type Si substrate and were covered with an Au thin-film. These structures act as antennas for near-infrared light, resulting in an enhancement of the light absorption on the Au film. Because the Schottky junction is formed between the Au/n-type Si, the electron excited by the absorbed light can be detected as photocurrent. The optical measurement revealed that the nano-pillar structures enhanced the responsivity for the near-infrared light by 89 (14.5 mA/W) and 16 (0.433 mA/W) times compared with those of the photodetector without nano-pillars at the wavelengths of 1.2 and 1.3 μm, respectively. Moreover, no polarization dependency of the responsivity was observed, and the acceptable incident angle ranged from 0° to 30°. These broad responses were likely to be due to the organic nano-pillar structures' having variation in their orientation, which is advantageous for near-infrared detector uses.

  11. Progress toward red and near-infrared (NIR) emitting saccharide sensors*

    OpenAIRE

    Sibrian-Vazquez, Martha; Escobedo, Jorge O.; Lowry, Mark; Strongin, Robert M.

    2012-01-01

    Red-shifted and near-infrared (NIR)-active rhodamine analogs and their boronic acid derivatives were synthesized and studied. These latter compounds function as fluorogenic NIR active substrates for sugar sensing. The effects of benzannulation and boronic acid functionalization on fluorophore optical and sensing properties are described.

  12. Main-belt asteroids with WISE/NEOWISE: Near-infrared albedos

    International Nuclear Information System (INIS)

    We present revised near-infrared albedo fits of 2835 main-belt asteroids observed by WISE/NEOWISE over the course of its fully cryogenic survey in 2010. These fits are derived from reflected-light near-infrared images taken simultaneously with thermal emission measurements, allowing for more accurate measurements of the near-infrared albedos than is possible for visible albedo measurements. Because our sample requires reflected light measurements, it undersamples small, low-albedo asteroids, as well as those with blue spectral slopes across the wavelengths investigated. We find that the main belt separates into three distinct groups of 6%, 16%, and 40% reflectance at 3.4 μm. Conversely, the 4.6 μm albedo distribution spans the full range of possible values with no clear grouping. Asteroid families show a narrow distribution of 3.4 μm albedos within each family that map to one of the three observed groupings, with the (221) Eos family being the sole family associated with the 16% reflectance 3.4 μm albedo group. We show that near-infrared albedos derived from simultaneous thermal emission and reflected light measurements are important indicators of asteroid taxonomy and can identify interesting targets for spectroscopic follow-up.

  13. Mechanisms of radon loss from zircon: Microstructural controls on emanation and diffusion

    Science.gov (United States)

    Eakin, Marty; Brownlee, S. J.; Baskaran, M.; Barbero, L.

    2016-07-01

    Understanding how radon escapes from minerals is important for many fields in Earth science, yet few studies have focused on the mechanisms for radon escape. We measured radon emanation rate and radon loss upon heating for crushed aliquots of three large zircon crystals from three localities: Mud Tank (Australia), Bancroft (Canada), and Malawi (Africa). Our study, in conjunction with published data, shows that the room temperature radon emanation coefficient (REC) varies over 5 orders of magnitude in zircon. For low U zircon, Mud Tank, there are variations in REC that appear to be related to annealing at different temperatures, possibly due to annealing of fission tracks, however, all REC values for Mud Tank zircon are within error of one another. Bancroft and Malawi zircons have higher U content and do not show any systematic relationship of REC to annealing temperature. Results from Mud Tank zircon suggest that partial annealing of fission tracks decreases REC, but when all fission tracks are annealed REC reaches a maximum. REC in zircons with high U content, Bancroft and Malawi, is slightly higher than in zircon with lower U, although results are within error. Results of measurements of radon loss upon heating suggest that radon diffusion is slow, ∼30% of the radon is lost during heating at 975 °C for 48 h. Samples heated a second time yield less fractional radon loss, ∼10%, suggesting that diffusion parameters are changed during heating at temperatures ⩾975 °C, which is likely the result of annealing of radiation damage. Diffusion parameters calculated from the fractional loss experiments reflect diffusion in highly radiation damaged or metamict zircons. Our results indicate that internal microstructures in zircon, such as fission tracks and alpha-radiation damage, influence radon escape for diffusion and recoil mechanisms, and hence if these effects can be further characterized, measurements of 222Rn escape have the potential to be useful for probing

  14. [The research progress in determining lignocellulosic content by near infrared reflectance spectroscopy technology].

    Science.gov (United States)

    Du, Juan; An, Dong; Xia, Tian; Huang, Yan-Hua; Li, Hong-Chao; Zhang, Yun-Wei

    2013-12-01

    Near infrared reflectance spectroscopy technology, as a new analytic method, can be used to determine the content of lignin, cellulose and hemi-cellulose which is faster, effective, easier to operate, and more accurate than the traditional wet chemical methods. Nowadays it has been widely used in measuring the composition of lignocelluloses in woody plant and herbaceous plant. The domestic and foreign research progress in determining the lignin, cellulose and hemi-cellulose content in woody plant ( wood and bamboo used as papermaking raw materials and wood served as potential biomass energy) and herbaceous plant (forage grass and energy grass) by near infrared reflectance spectroscopy technology is comprehensively summarized and the advances in method studies of measuring the composition of lignocelluloses by near infrared reflectance spectroscopy technology are summed up in three aspects, sample preparation, spectral data pretreatment and wavelength selection methods, and chemometric analysis respectively. Four outlooks are proposed combining the development statues of wood, forage grass and energy grass industry. First of all, the authors need to establish more feasible and applicable models for a variety of uses which can be used for more species from different areas, periods and anatomical parts. Secondly, comprehensive near infrared reflectance spectroscopy data base of grass products quality index needs to be improved to realize on-line quality and process control in grassproducts industry, which can guarantee the quality of the grass product. Thirdly, the near infrared reflectance spectroscopy quality index model of energy plant need to be built which can not only contribute to breed screening, but also improve the development of biomass industry. Besides, modeling approaches are required to be explored and perfected any further. Finally, the authors need to try our best to boost the advancement in the determination method of lignin, cellulose and hemi

  15. Near-infrared luminescence of Tm3+-doped CeO2 films based on silicon substrates

    International Nuclear Information System (INIS)

    CeO2/Tm2O3 multilayer films were deposited on silicon substrates by electron-beam evaporation. Tm3+ ions were doped in CeO2 after the films were annealed in oxygen atmosphere at 1000 C. The doping concentration of Tm3+ varies in the range of 0.1-3 mol%. A series of near-infrared emission peaks were observed under the excitation of 330 nm, which correspond to 1G4-3H5, 3H4-3H6, 1G4-3H4, 3H5-3H6, 3F2-3H5, 3H4-3F4, 1G4-3F3,2 and 3F4-3H6 transitions of Tm3+, respectively. The dominant transition of 3H4-3H6 near 805 nm was within optical transmission window. The luminescence properties and the crystal structure of CeO2:Tm3+ films were investigated by excitation and emission spectroscopy and X-ray diffraction. Meanwhile, the substitution process of Ce4+ by Tm3+ was illustrated, and lattice expansion of the matrix CeO2 gave rise to the increase in FWHM of CeO2 diffraction peaks. In addition, the effect of Tm3+ concentration on photoluminescence was also studied, and the optimal concentration of Tm3+ was 0.5 mol%. (orig.)

  16. Near-infrared hyperspectral imaging: the road traveled to a clinical burn application

    Science.gov (United States)

    Levasseur, Michelle; Leonardi, Lorenzo; Payette, Jeri; Kohlenberg, Elicia; Sowa, Michael; Fish, Joel S.; Cross, Karen; Gomez, Manuel

    2005-09-01

    The process of taking a concept to a clinical device begins with the idea for a technological solution to an unmet clinical challenge. Burns are one of the most destructive insults to the skin causing damage, scarring, and in some cases death. The approach most commonly used to evaluate burns is based on the appearance of the wound. This technique is somewhat subjective and unreliable, relying on clinical experience to assess the burn. Instrument based diagnostic techniques as an adjunct to current practices has the potential to enhance the quality and timeliness of decisions concerning wound assessment and treatment. Near Infrared Spectroscopy is a promising technique that can track changes within the tissue, and can therefore provide insight as to how deep the burn actually penetrates before visual signs become apparent. Preliminary bench and animal studies were used to prove the concept of a near infrared based method of burn assessment. This study demonstrated the ability of near infrared imaging to detect and monitor the hemodynamics of burn injuries in the early post-burn period. Based on this study, a pre-prototype near infrared spectroscopic system was built with the goal of developing a reliable yet simple system that could be used in a clinical setting. A pilot clinical study was designed and implemented at the Ross Tilley Burn Center (Toronto, Canada) in order to assess the feasibility of our strategy in the clinical realm. The goal of this preliminary clinical study was to determine if the pre-prototype could be integrated into the strict regiment of an active burn centre. Both the instrument performance in a clinical setting and the injury assessment based on the analysis of near infrared reflectance measurements were a success.

  17. Optical constants and near infrared emission of Er doped ZnO sol–gel thin films

    International Nuclear Information System (INIS)

    Erbium (Er) doped zinc oxide (ZnO) sol–gel thin films were deposited on glass substrate using the spin coating method. The effect of erbium concentration and annealing temperature on structural and optical properties was studied. The annealed film was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDX), micro-Raman, photoluminescence (PL) and UV–vis spectroscopy. All the films showed a wurtzite structure of polycrystalline nature with an average crystal size of 27.44 nm at 500 °C and 29.28 nm at 600 °C. The Raman spectra confirmed the absence of secondary phases in the Er doped ZnO films and the longitudinal optical phonon mode was upto the fifth order. Densely packed surfaces of the films were observed from SEM images. The presence and distribution of Zn, O and Er elements in the deposited films were confirmed by EDX analysis. The calculated value of exciton binding energy of ZnO film was 60 meV with a maximum value of 72 meV being observed for Er doped films. The near infra-red emission peak was observed at 1.63 eV through PL spectra studies. The average transmission was 80% with the calculated value of optical band gap being 3.26–3.32 eV. An increase in the refractive index value predicts the substitutional incorporation of Er ions in ZnO with the maximum optical conductivity being observed in the UV region. - Highlights: • Higher exciton binding energy in the doped ZnO films. • Near infrared emission is observed and better than ZnO. • Refractive index is calculated by theoretical and experimental means. • Maximum optical conductivity in the UV region

  18. Optical constants and near infrared emission of Er doped ZnO sol–gel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Vettumperumal, R. [P.G. and Research Department of Physics, Sri Paramakalyani College, Alwarkurichi 627412, Tamil Nadu (India); Kalyanaraman, S., E-mail: mayura_priya2003@yahoo.co.in [P.G. and Research Department of Physics, Sri Paramakalyani College, Alwarkurichi 627412, Tamil Nadu (India); Thangavel, R., E-mail: rtvel_au@yahoo.co.in [Department of Applied Physics, Indian School of Mines, Dhanbad (India)

    2015-02-15

    Erbium (Er) doped zinc oxide (ZnO) sol–gel thin films were deposited on glass substrate using the spin coating method. The effect of erbium concentration and annealing temperature on structural and optical properties was studied. The annealed film was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDX), micro-Raman, photoluminescence (PL) and UV–vis spectroscopy. All the films showed a wurtzite structure of polycrystalline nature with an average crystal size of 27.44 nm at 500 °C and 29.28 nm at 600 °C. The Raman spectra confirmed the absence of secondary phases in the Er doped ZnO films and the longitudinal optical phonon mode was upto the fifth order. Densely packed surfaces of the films were observed from SEM images. The presence and distribution of Zn, O and Er elements in the deposited films were confirmed by EDX analysis. The calculated value of exciton binding energy of ZnO film was 60 meV with a maximum value of 72 meV being observed for Er doped films. The near infra-red emission peak was observed at 1.63 eV through PL spectra studies. The average transmission was 80% with the calculated value of optical band gap being 3.26–3.32 eV. An increase in the refractive index value predicts the substitutional incorporation of Er ions in ZnO with the maximum optical conductivity being observed in the UV region. - Highlights: • Higher exciton binding energy in the doped ZnO films. • Near infrared emission is observed and better than ZnO. • Refractive index is calculated by theoretical and experimental means. • Maximum optical conductivity in the UV region.

  19. Slow light enhanced near infrared luminescence in CeO2: Er3+, Yb3+ inverse opal photonic crystals

    International Nuclear Information System (INIS)

    Highlights: • CeO2: Er3+, Yb3+ photonic crystals was prepared. • Near infrared emission in the CeO2: Er3+, Yb3+ inverse opal was obtained. • Near infrared emission was enhanced by slow light effect of photonic crystals. - Abstract: The surface plasmon resonances of metal nanoparticles and energy transfer between rare earth ions were used widely to enhance the near infrared emission of rare earth ions. In this paper, a new method for near infrared emission enhancement of rare-earth is reported. The CeO2: Er3+, Yb3+ inverse opals with the photonic band gaps at the 500 and 450 nm were prepared by using polystyrene colloidal crystal as templates, and their near infrared emission properties were investigated. The results show that the near infrared emission property of the CeO2: Er3+, Yb3+ inverse opals depends on the overlapped extend between the excited light and photonic band gap. The near infrared emission located at the 1540 nm of the CeO2: Er3+, Yb3+ inverse opals have been enhanced obviously when the wavelength of the excitation light overlapped with photonic band gaps edge, which is attributed to the slow light effect of photonic crystals. The enhancement of near infrared emission may be important for the development of infrared laser and amplifiers for optical communication

  20. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide

    Science.gov (United States)

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm2 C-1 at 650 nm and 255 cm2 C-1 at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions.In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured

  1. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    International Nuclear Information System (INIS)

    We performed a near-infrared spectroscopic survey toward an area of ∼10 deg2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R ∼ 20) spectra in 2-5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near-infrared

  2. Preparation of Ag/SiO{sub 2} near-infrared absorbers using the combination of sputtering and spin-coating depositions

    Energy Technology Data Exchange (ETDEWEB)

    Liau, Leo Chau-Kuang, E-mail: lckliau@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 320, Taiwan (China); Lai, Guo-Bin [Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li 320, Taiwan (China); Juang, Rei-Cheng; Chang, Bing-Hung [Green Energy and Environmental Laboratories, Industrial Technology Research Institute, Hsinchu 300, Taiwan (China); Yang, Thomas Chun-Kuang [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan (China)

    2015-03-02

    This study presents the design and fabrication of near-infrared (NIR) absorbers constructed in multilayer structures using Ag and SiO{sub 2} materials. The absorbers, consisting of Ag and SiO{sub 2} films, were fabricated using sputtering and spin-coating approaches, respectively. The fabricated absorbing devices were evaluated using ultraviolet–visible-NIR spectra. Results revealed that the structure of the Ag/SiO{sub 2}/Ag films exhibited an NIR absorbing effect. The absorbing properties were substantially influenced by the fabrication parameters and the thickness of the multilayer films. Furthermore, the NIR absorbing performance improved significantly when the SiO{sub 2} layer was annealed at 300 °C before the deposition of the top Ag film. Additionally, the absorptance of the absorbers was affected by the thickness of the top Ag layer. The long-term stability of the multilayer absorber was tested and verified based on absorptance data analysis. The NIR absorbing performance can be further improved using the optimal device design of the film thickness and by fabricating additional Ag/SiO{sub 2} layers. - Highlights: • Ag/SiO{sub 2} near-infrared absorbers were designed and fabricated. • The absorbing performance was greatly influenced by the fabrication schemes. • The optimal fabrication process of the absorber was obtained. • The long-term stability of the absorber was verified.

  3. Preparation of Ag/SiO2 near-infrared absorbers using the combination of sputtering and spin-coating depositions

    International Nuclear Information System (INIS)

    This study presents the design and fabrication of near-infrared (NIR) absorbers constructed in multilayer structures using Ag and SiO2 materials. The absorbers, consisting of Ag and SiO2 films, were fabricated using sputtering and spin-coating approaches, respectively. The fabricated absorbing devices were evaluated using ultraviolet–visible-NIR spectra. Results revealed that the structure of the Ag/SiO2/Ag films exhibited an NIR absorbing effect. The absorbing properties were substantially influenced by the fabrication parameters and the thickness of the multilayer films. Furthermore, the NIR absorbing performance improved significantly when the SiO2 layer was annealed at 300 °C before the deposition of the top Ag film. Additionally, the absorptance of the absorbers was affected by the thickness of the top Ag layer. The long-term stability of the multilayer absorber was tested and verified based on absorptance data analysis. The NIR absorbing performance can be further improved using the optimal device design of the film thickness and by fabricating additional Ag/SiO2 layers. - Highlights: • Ag/SiO2 near-infrared absorbers were designed and fabricated. • The absorbing performance was greatly influenced by the fabrication schemes. • The optimal fabrication process of the absorber was obtained. • The long-term stability of the absorber was verified

  4. Double ionization of helium by intense near-infrared and VUV laser pulses

    International Nuclear Information System (INIS)

    We investigate the dynamics of double ionization of He atom by an intense near-infrared and an attosecond vacuum ultraviolet (VUV) laser pulse, which are either applied in sequence or at the same time. To this end we solve the time-dependent Schroedinger equation for a two-electron model atom interacting with the two fields. We compare the double-ionization yields and probability density distributions, with and without the application of the attosecond pulse, for the different scenarios. The results of our numerical simulations show how ionization or excitation of the neutral atom by a preceding or simultaneously applied VUV pulse affects the double-ionization dynamics driven by the near-infrared laser pulse. The findings provide insights regarding the question if attosecond technology can be used to temporally resolve mechanisms of correlated emission of electrons in a strong laser field.

  5. Concurrent Application of TMS and Near-infrared Optical Imaging: Methodological Considerations and Potential Artifacts

    Directory of Open Access Journals (Sweden)

    Nathan A Parks

    2013-09-01

    Full Text Available The simultaneous application of transcranial magnetic stimulation (TMS with non-invasive neuroimaging provides a powerful method for investigating functional connectivity in the human brain and the causal relationships between areas in distributed brain networks. TMS has been combined with numerous neuroimaging techniques including, electroencephalography (EEG, functional magnetic resonance imaging (fMRI, and positron emission tomography (PET. Recent work has also demonstrated the feasibility and utility of combining TMS with non-invasive near-infrared optical imaging techniques, functional near-infrared spectroscopy (fNIRS and the event-related optical signal (EROS. Simultaneous TMS and optical imaging affords a number of advantages over other neuroimaging methods but also involves a unique set of methodological challenges and considerations. This paper describes the methodology of concurrently performing optical imaging during the administration of TMS, focusing on experimental design, potential artifacts, and approaches to controlling for these artifacts.

  6. Effect of motion artifacts and their correction on near-infrared spectroscopy oscillation data

    DEFF Research Database (Denmark)

    Selb, Juliette; Yücel, Meryem A; Phillip, Dorte;

    2015-01-01

    Functional near-infrared spectroscopy is prone to contamination by motion artifacts (MAs). Motion correction algorithms have previously been proposed and their respective performance compared for evoked rain activation studies. We study instead the effect of MAs on "oscillation" data which is at...... the basis of functional connectivity and autoregulation studies. We use as our metric of interest the interhemispheric correlation (IHC), the correlation coefficient between symmetrical time series of oxyhemoglobin oscillations. We show that increased motion content results in a decreased IHC. Using a...... in the frequency band around 0.1 and 0.04 Hz, suggesting a physiological origin for the difference. We emphasize the importance of considering MAs as a confounding factor in oscillation-based functional near-infrared spectroscopy studies....

  7. Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

    International Nuclear Information System (INIS)

    Bulk silicon carbide (SiC) is a very promising material system for bio-applications and quantum sensing. However, its optical activity lies beyond the near infrared spectral window for in-vivo imaging and fiber communications due to a large forbidden energy gap. Here, we report the fabrication of SiC nanocrystals and isolation of different nanocrystal fractions ranged from 600 nm down to 60 nm in size. The structural analysis reveals further fragmentation of the smallest nanocrystals into ca. 10-nm-size clusters of high crystalline quality, separated by amorphization areas. We use neutron irradiation to create silicon vacancies, demonstrating near infrared photoluminescence. Finally, we detect room-temperature spin resonances of these silicon vacancies hosted in SiC nanocrystals. This opens intriguing perspectives to use them not only as in-vivo luminescent markers but also as magnetic field and temperature sensors, allowing for monitoring various physical, chemical, and biological processes

  8. 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.

  9. 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...

  10. Near-infrared electroluminescent devices using single-wall carbon nanotubes thin flms

    Science.gov (United States)

    Kazaoui, S.; Minami, N.; Nalini, B.; Kim, Y.; Takada, N.; Hara, K.

    2005-11-01

    We have fabricated near-infrared electroluminescent (EL) devices utilizing single-wall carbon nanotubes (SWNTs) finely dispersed in a polymer, such as poly[2-methoxy-5-(2'-ethylhexyloxy]-1,4-phenylenevinylene (MEHPPV). Al/SWNT-MEHPPV/indium tin oxide thin-film devices exhibit a very promising EL response over a broad spectrum, including the range of 900-1600nm. From the analysis of the optical absorption, photoluminescence and EL spectra, as well as the current-voltage characteristics, we demonstrate that those devices exploit the intrinsic near-infrared light-emitting properties of semiconducting SWNTs and the electronic transport properties of SWNT-doped MEHPPV. Those achievements are essential for the future development of thin-film SWNT optoelectronic devices.

  11. Identification of oil spills by near-infrared spectroscopy (NIR) and support vector machine (SVM)

    Science.gov (United States)

    Bi, Weihong; Tan, Ailing; Zhao, Yong; Gao, Meijing

    2009-11-01

    The identification of the spilled oil is an essential and important part in the investigation and handling of oil spill accidents. The combination of near-infrared spectroscopy (NIR) and chemometrics is ideal for such a situation. NIR spectroscopy is a powerful and effective technique and qualitative information can be obtained with classification models. Support vector machines (SVM) have been introduced recently in chemometrics and have proven to be powerful in NIR spectra classification tasks, such as material identification and food discrimination. In this work, the SVM is utilized to classify near infrared spectroscopy of simulated spilled oils of gasoline, diesel fuel and kerosene on the marine. A good classification performance is obtained :the identification rate were 100%, 96% and 98% on the test sets respectively.

  12. Electrochemical redox-based tuning of near infrared localized plasmons of CuS nanoplates

    Science.gov (United States)

    Asami, Keisuke; Nishi, Hiroyasu; Tatsuma, Tetsu

    2016-07-01

    Fast and reversible control of the plasmonic properties of compound nanoparticles (i.e. CuS nanoplates) was achieved through electrochemical redox reactions. Their electrochemical tunability can be applied to fast-switching near infrared electrochromic devices, whose visible appearance is not changed by switching.Fast and reversible control of the plasmonic properties of compound nanoparticles (i.e. CuS nanoplates) was achieved through electrochemical redox reactions. Their electrochemical tunability can be applied to fast-switching near infrared electrochromic devices, whose visible appearance is not changed by switching. Electronic supplementary information (ESI) available: TEM images, absorption spectra and electrochromic response of CuS nanoplates and the relationship between the relative amount of CuS and absorbance change. See DOI: 10.1039/c6nr03709g

  13. Pushing graphene plasmon polaritons to the near-infrared window by block copolymer nanolithography

    CERN Document Server

    Wang, Zhongli; Almdal, Kristoffer; Mortensen, N Asger; Xiao, Sanshui; Ndoni, Sokol

    2016-01-01

    Due to strong mode-confinement, long propagation-distance, and unique tunability, graphene plasmon polaritons 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 concepts with existing mature technologies in the near-infrared region. We investigate localized graphene plasmons supported by graphene nanodisk arrays, which are fabricated by a fully scalable block copolymer (BCP) self-assembly method. BCP masks with well-ordered vertically oriented cylinder or monolayer packed sphere morphologies are utilized to pattern graphene over centimeter scale dimensions. By carefully controlling the dry-etching time and by choosing an appropriate BCP mask, the wavelength of the localized graphene plasmons can be pushed down to and even below 2 um. Our results show a promising way to promote graphene plasmons for both fundamental studies and potential applications in the near-infrared...

  14. Design and spectroscopic characterization of novel series of near infrared indocyanine dyes

    Science.gov (United States)

    Abd-El-Aziz, Alaa S.; Strohm, Elizabeth A.; Okasha, Rawda M.

    2015-07-01

    A novel series of near infrared heptamethine indocyanine dyes bearing various aromatic chromophores has been synthesized. The synthetic methodology was achieved via ester condensation reactions of heptamethine indocyanine parent dye with carboxylic moiety and aromatic compounds such as anthracene, pyrene and thiophene derivatives. Structural analysis of the newly prepared dyes was accomplished using one- and two-dimensional nuclear magnetic resonance, infrared spectroscopy and electrospray ionization mass spectrometry. These dyes exhibited high molar absorptivity based on the UV-visible/near-infrared spectral data. Fluorescence emission spectral data was used to determine the relative quantum yield. The new dyes displayed formation of H-aggregates in water at low concentrations, while this behavior was not observed in methanol.

  15. In Vivo Tumor Angiogenesis Imaging Using Peptide-Based Near-Infrared Fluorescent Probes.

    Science.gov (United States)

    Huang, Rui; Conti, Peter S; Chen, Kai

    2016-01-01

    Near-infrared fluorescence (NIRF) imaging is an emerging imaging technique for studying diseases at the molecular level. Optical imaging with a near-infrared emitting fluorophore for targeting tumor angiogenesis offers a noninvasive method for early tumor detection and efficient monitoring of tumor response to anti-angiogenesis therapy. CD13 receptor, a zinc-dependent membrane-bound ectopeptidase, plays important roles in regulating tumor angiogenesis and the growth of new blood vessels. In this chapter, we use CD13 receptor as an example to demonstrate how to construct CD13-specific NGR-containing peptides via bioorthogonal click chemistry for visualizing and quantifying the CD13 receptor expression in vivo by means of NIRF optical imaging. PMID:27283419

  16. Semiconducting Polymer Nanoparticles with Persistent Near-Infrared Luminescence for In Vivo Optical Imaging.

    Science.gov (United States)

    Palner, Mikael; Pu, Kanyi; Shao, Shirley; Rao, Jianghong

    2015-09-21

    Materials with persistent luminescence are attractive for in vivo optical imaging since they have a long lifetime that allows the separation of excitation of fluorophores and image acquisition for time-delay imaging, thus eliminating tissue autofluorescence associated with fluorescence imaging. Persistently luminescent nanoparticles have previously been fabricated from toxic rare-earth metals. This work reports that nanoparticles made of the conjugated polymer MEH-PPV can generate luminescence persisting for an hour upon single excitation. A near-infrared dye was encapsulated in the conjugated polymer nanoparticle to successfully generate persistent near-infrared luminescence through resonance energy transfer. This new persistent luminescence nanoparticles have been demonstrated for optical imaging applications in living mice. PMID:26223794

  17. Utilization of functional near infrared spectroscopy for non-invasive evaluation

    Science.gov (United States)

    Halim, A. A. A.; Laili, M. H.; Aziz, N. A.; Laili, A. R.; Salikin, M. S.; Rusop, M.

    2016-07-01

    The goal of this brief review is to report the techniques of functional near infrared spectroscopy for non-invasive evaluation in human study. The development of functional near infrared spectroscopy (fNIRS) technologies has advanced quantification signal using multiple wavelength and detector to solve the propagation of light inside the tissues including the absorption, scattering coefficient and to define the light penetration into tissues multilayers. There are a lot of studies that demonstrate signal from fNIRS which can be used to evaluate the changes of oxygenation level and measure the limitation of muscle performance in human brain and muscle tissues. Comprehensive reviews of diffuse reflectance based on beer lambert law theory were presented in this paper. The principle and development of fNIRS instrumentation is reported in detail.

  18. Near-infrared line identification in type Ia supernovae during the transitional phase

    International Nuclear Information System (INIS)

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of 58Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  19. Investigation of near infrared autofluorescence imaging for the detection of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Demos, S G; Bold, R; White, R d; Ramsamooj, R

    2005-08-19

    Detection of breast cancer in fresh tissue obtained from surgery is investigated using Near-infrared autofluorescence imaging under laser excitation at 532-nm and 632.8-nm. The differences in intensity between the three main components of breast tissue (cancer, fibrous and adipose) are estimated and compared to those obtained from cross-polarized light scattering images recorded under polarized illumination at 700-nm. The optical spectroscopic images for each tissue sample were subsequently compared with the histopathology slides. The experimental results indicate that the intensity of the near-infrared emission is considerably different in breast cancer compared to that of the adjacent non-neoplastic tissues (adipose and fibrous tissue). The experimental results suggest that 632.8-nm excitation offers key advantages compared to 532-nm excitation.

  20. Quantum efficiencies of near-infrared emission from Ni2+-doped glass-ceramics

    International Nuclear Information System (INIS)

    A systematic method to evaluate potentials of Ni2+-doped transparent glass-ceramics as a new broadband optical gain media is presented. At first, near-infrared emission of various ceramics were investigated to explore the suitable crystalline phase to be grown in the glass-ceramics. The quantum efficiency of Ni2+ near-infrared emission estimated by the Struck-Fonger analysis was higher than 95% for spinel-type structure gallate crystals MgGa2O4 and LiGa5O8 at room temperature. Transparent glass-ceramics containing Ni2+:LiGa5O8 could be prepared and the quantum efficiency for the glass-ceramics was measured to be about 10%. This value shows a potential of Ni-doped transparent glass-ceramics as a broadband gain media

  1. 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.

  2. Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

    Science.gov (United States)

    Muzha, A.; Fuchs, F.; Tarakina, N. V.; Simin, D.; Trupke, M.; Soltamov, V. A.; Mokhov, E. N.; Baranov, P. G.; Dyakonov, V.; Krueger, A.; Astakhov, G. V.

    2014-12-01

    Bulk silicon carbide (SiC) is a very promising material system for bio-applications and quantum sensing. However, its optical activity lies beyond the near infrared spectral window for in-vivo imaging and fiber communications due to a large forbidden energy gap. Here, we report the fabrication of SiC nanocrystals and isolation of different nanocrystal fractions ranged from 600 nm down to 60 nm in size. The structural analysis reveals further fragmentation of the smallest nanocrystals into ca. 10-nm-size clusters of high crystalline quality, separated by amorphization areas. We use neutron irradiation to create silicon vacancies, demonstrating near infrared photoluminescence. Finally, we detect room-temperature spin resonances of these silicon vacancies hosted in SiC nanocrystals. This opens intriguing perspectives to use them not only as in-vivo luminescent markers but also as magnetic field and temperature sensors, allowing for monitoring various physical, chemical, and biological processes.

  3. Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects

    Energy Technology Data Exchange (ETDEWEB)

    Muzha, A. [Institute of Organic Chemistry, Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Fuchs, F.; Simin, D.; Astakhov, G. V., E-mail: astakhov@physik.uni-wuerzburg.de [Experimental Physics VI, Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Tarakina, N. V. [Wilhelm Conrad Röntgen Research Centre for Complex Material Systems (RCCM), Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Experimental Physics III, Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Trupke, M. [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Wien (Austria); Soltamov, V. A.; Mokhov, E. N.; Baranov, P. G. [Ioffe Physical-Technical Institute, 194021 St. Petersburg (Russian Federation); Dyakonov, V. [Experimental Physics VI, Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Wilhelm Conrad Röntgen Research Centre for Complex Material Systems (RCCM), Julius-Maximilian University of Würzburg, 97074 Würzburg (Germany); Bavarian Center for Applied Energy Research (ZAE Bayern), 97074 Würzburg (Germany); and others

    2014-12-15

    Bulk silicon carbide (SiC) is a very promising material system for bio-applications and quantum sensing. However, its optical activity lies beyond the near infrared spectral window for in-vivo imaging and fiber communications due to a large forbidden energy gap. Here, we report the fabrication of SiC nanocrystals and isolation of different nanocrystal fractions ranged from 600 nm down to 60 nm in size. The structural analysis reveals further fragmentation of the smallest nanocrystals into ca. 10-nm-size clusters of high crystalline quality, separated by amorphization areas. We use neutron irradiation to create silicon vacancies, demonstrating near infrared photoluminescence. Finally, we detect room-temperature spin resonances of these silicon vacancies hosted in SiC nanocrystals. This opens intriguing perspectives to use them not only as in-vivo luminescent markers but also as magnetic field and temperature sensors, allowing for monitoring various physical, chemical, and biological processes.

  4. Near-Infrared Fluorescence Enhanced (NIR-FE) Molecular Imaging of Live Cells on Gold Substrates

    CERN Document Server

    Hong, Guosong; Welsher, Kevin; Chen, Zhuo; Robinson, Joshua T; Wang, Hailiang; Zhang, Bo; Dai, Hongjie

    2011-01-01

    Low quantum yields of near infrared (NIR) fluorophores have limited their capabilities as imaging probes in a transparent, low background imaging window. Here for the first time we reported near-infrared fluorescence enhance (NIR-FE) cell imaging using nanostructured Au substrate, which was employed as a general platform for both single-walled carbon nanotubes (SWNTs) and organic fluorescent labels in the NIR region. Fluorescence intensity, as well as cell targeting specificity, was greatly improved by this novel imaging technique. With NIR-FE imaging, we were able to image SWNT-stained cells at short exposure time of 300ms, and push the detectable limit of SWNT staining of cells down to an ultralow concentration of ~50 pM. Further, different degrees of fluorescence enhancement for endocytosed, intracellular SWNTs vs. nanotubes on the cell membrane at the cell/gold interface were observed, suggesting the possibility of using this technique to track the transmembrane behavior of NIR fluorophores.

  5. Batch and continuous blending of particulate material studied by near-infrared spectroscopy

    OpenAIRE

    Martínez Heredia, Lizbeth Araceli

    2013-01-01

    Background: Pharmaceutical manufacturing is moving towards real-time release of the products. This objective can only be achieved by clearly understanding the process and by implementing suitable technologies for manufacturing and for process control. Near-infrared (NIR) spectroscopy is one technology that has attracted lot of attention from the pharmaceutical industry since it can analyze bulk solids without any pretreatment, therefore reducing or eliminating wet chemistr...

  6. MULTISCALE GUIDED DEBLURRING: CHROMATIC ABERRATION CORRECTION IN COLOR AND NEAR-INFRARED IMAGING

    OpenAIRE

    Sadeghipoor Kermani, Zahra; Lu, Yue; Mendez, Erick; Süsstrunk, Sabine

    2015-01-01

    Chromatic aberration, caused by photographic lens imperfections, results in the image of only one spectral channel being sharp, while the other channels are blurred depending on their wavelengths difference with the sharp channel. We study chromatic aberration for a system that jointly records color and near-infrared (NIR) images on a single sensor. Chromatic aberration in such a system leads to a blurred NIR image when the color image is in-focus and sharp. We propose an algorithm that deblu...

  7. Single camera imaging system for color and near-infrared fluorescence image guided surgery

    OpenAIRE

    Chen, Zhenyue; Zhu, Nan; Pacheco, Shaun; Wang, Xia; Liang, Rongguang

    2014-01-01

    Near-infrared (NIR) fluorescence imaging systems have been developed for image guided surgery in recent years. However, current systems are typically bulky and work only when surgical light in the operating room (OR) is off. We propose a single camera imaging system that is capable of capturing NIR fluorescence and color images under normal surgical lighting illumination. Using a new RGB-NIR sensor and synchronized NIR excitation illumination, we have demonstrated that the system can acquire ...

  8. Near infrared face recognition by combining Zernike moments and undecimated discrete wavelet transform

    Czech Academy of Sciences Publication Activity Database

    Farokhi, Sajad; Shamsuddin, S.M.; Sheikh, U.U.; Flusser, Jan; Khansari, M.; Jafari-Khouzani, K.

    2014-01-01

    Roč. 31, č. 1 (2014), s. 13-27. ISSN 1051-2004 R&D Projects: GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Zernike moments * Undecimated discrete wavelet transform * Decision fusion * Near infrared * Face recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 1.256, year: 2014 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0428536.pdf

  9. 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 water droplets are shown to be strong. Despite the strong influence of the water phase, the NIR technique is still capable of predicting the composition of the investigated oil phase....

  10. The convection of close red supergiant stars observed with near-infrared interferometry

    CERN Document Server

    Montargès, Miguel; Perrin, Guy; Chiavassa, Andrea; Aurière, Michel

    2015-01-01

    Our team has obtained observations of the photosphere of the two closest red supergiant stars Betelgeuse ($\\alpha$ Ori) and Antares ($\\alpha$ Sco) using near infrared interferometry. We have been monitoring the photosphere of Betelgeuse with the VLTI/PIONIER instrument for three years. On Antares, we obtained an unprecedented sampling of the visibility function. These data allow us to probe the convective photosphere of massive evolved stars.

  11. Near-infrared photonic energy penetration: can infrared phototherapy effectively reach the human brain?

    OpenAIRE

    Henderson TA; Morries LD

    2015-01-01

    Theodore A Henderson,1,2 Larry D Morries2 1The Synaptic Space, Centennial, CO, USA; 2Neuro-Laser Foundation, Lakewood, CO, USA Abstract: Traumatic brain injury (TBI) is a growing health concern effecting civilians and military personnel. Research has yielded a better understanding of the pathophysiology of TBI, but effective treatments have not been forthcoming. Near-infrared light (NIR) has shown promise in animal models of both TBI and stroke. Yet, it remains unclear if sufficient photoni...

  12. Characterization of lignin amount and composition by near infrared spectroscopy and analytical pyrolisis

    OpenAIRE

    Alves, Ana Maria Martins

    2010-01-01

    Doutoramento em Engenharia Florestal - Instituto Superior de Agronomia In this work analytical pyrolysis and near infrared spectroscopy (NIR) were used to assess lignin amount and composition, namely the H/G (phydroxyphenyl/ guaiacyl) ratio, in the wood of three softwood species Pinus pinaster, Picea abies and Larix sp.. A method was developed for the quantification of lignin directly from analytical pyrolysis results (Py-lignin). A good correlation was found between Py-l...

  13. DETERMINATION OF LIGNIN CONTENT IN ACACIA SPP. USING NEAR-INFRARED REFLECTANCE SPECTROSCOPY

    OpenAIRE

    Sheng Yao; Guofen Wu; Mian Xing; Shuke Zhou; Junwen Pu

    2010-01-01

    Near infrared (NIR) spectroscopy method was introduced to measure the lignin content in Acacia species. Acid-soluble lignin, Klason lignin, and total lignin contents from 78 wood meal samples of Acacia spp. trees grown in Guangxi province with different ages, height, and families were measured by wet chemistry. NIR spectra were also collected using a Bruker MPA spectrometer within 4000-12500cm-1 of wavenumbers using a standard sample cup and split into calibration and prediction sets. Equatio...

  14. 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.

  15. Near-infrared optical coherence tomography for the inspection of fiber composites

    OpenAIRE

    Liu, P; Yao, L.; Groves, R.M.

    2015-01-01

    Optical coherence tomography (OCT) is a non-invasive imaging method, which allows the econstruction of three dimensional depth-resolved images with microscale resolution. Originally developed for biomedical diagnostics, nowadays it also shows a high potential for applications in the field of non-destructive testing (NDT). This work demonstrates how OCT could help to investigate the delamination growth in fiber composites. A customized OCT system was built with a near-infrared light source wit...

  16. A near infrared vegetation index formed with airborne multispectral scanner data

    Science.gov (United States)

    Elvidge, Christopher D.; Rock, Barrett N.

    1987-01-01

    A near infrared vegetation index (NIVI) has been formed with the 1.24 and 1.65 micron bands on the NS001 Thematic Mapper Simulator. The NIVI was compared to the more traditional Perpendicular Vegetation Index (PVI) formed with the 0.66 and 0.83 micron bands. The PVI was found to be less susceptible to problems with rock and soil spectral variations than the VIVI.

  17. Advances in near-infrared spectroscopy to study the brain of the preterm and term neonate

    DEFF Research Database (Denmark)

    Wolf, Martin; Greisen, Gorm

    2009-01-01

    This article reviews tissue oximetry and imaging to study the preterm and newborn infant brain by near-infrared spectroscopy. These two technologies are now advanced; nearly 100 reports on their use in newborn infants have been published, and commercial instruments are available. The precision...... of oximetry, however, is a limitation for its clinical use of assessing cerebral oxygenation. Imaging of brain function needs very well defined protocols for sensory stimulation as well as signal analysis to provide meaningful results....

  18. Synthesis and application of novel near infrared cyanine dyes and optical imaging agents

    OpenAIRE

    Norouzi, Neil

    2014-01-01

    The use of fluorescent imaging probes for the real time detection of cellular malfunctions, such as enzyme over expression has shown promise. Fluorescent dyes with absorption and emission values below 600 nm are limited in their in vivo applications due to high background auto-fluorescence and low resolution images. Employing near infrared (NIR) fluorophores such as cyanine dyes can overcome this disadvantage. Cyanine dyes can be synthesised using solution or solid-phase tec...

  19. Multivariate Calibration Models for Sorghum Composition using Near-Infrared Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wolfrum, E.; Payne, C.; Stefaniak, T.; Rooney, W.; Dighe, N.; Bean, B.; Dahlberg, J.

    2013-03-01

    NREL developed calibration models based on near-infrared (NIR) spectroscopy coupled with multivariate statistics to predict compositional properties relevant to cellulosic biofuels production for a variety of sorghum cultivars. A robust calibration population was developed in an iterative fashion. The quality of models developed using the same sample geometry on two different types of NIR spectrometers and two different sample geometries on the same spectrometer did not vary greatly.

  20. Near- infrared spectroscopy of palladium-containing layered double hydroxides used as catalysts

    OpenAIRE

    Mora, Manuel; Lopez, María I.; Jiménez-Sanchidrián, César; Ruiz, José R.

    2011-01-01

    ABSTRACT Three catalysts consisting of layered double hydroxides (LDHs) of magnesium and aluminium, and containing palladium in various forms, were synthesized and subsequently characterized by mid- and near-infrared spectroscopies. The results thus obtained are compared with those for a pure Mg/Al layered double hydroxide. The spectra for the Pd-containing LDHs (particularly the strength of the bands) were found to depend on the particular palladium form present. As a rule, the mi...

  1. High precision radial velocities in the near-infrared domain: Status and prospects

    Directory of Open Access Journals (Sweden)

    Fiorenzano A.M.

    2011-07-01

    Full Text Available The extension of the highly successful Doppler technique into the near-infrared (0.9–2.5 μm is highly desirable as it would open the possibility for searches for extra-solar planets around young stars, very low-mass stars and brown dwarfs. Here we review the current status of this technique and discuss future prospects with particular emphasis on challenging problems for the next decade.

  2. Acoustic Events and “Optophonic” Cochlear Responses Induced by Pulsed Near-Infrared LASER

    OpenAIRE

    Teudt, Ingo Ulrik; Maier, Hannes; Richter, Claus-Peter; Kral, Andrej

    2011-01-01

    Optical stimulation of neural tissue within the cochlea was described as a possible alternative to electrical stimulation. Most optical stimulation was performed with pulsed lasers operating with near-infrared (NIR) light and in thermal confinement. Under these conditions, the coexistence of laser-induced optoacoustic stimulation of the cochlea (“optophony”) has not been analyzed yet. This study demonstrates that pulsed 1850-nm laser light used for neural stimulation also results in sound pre...

  3. Long-term histological comparison between near-infrared irradiated skin and scar tissues

    OpenAIRE

    Yohei Tanaka; Kiyoshi Matsuo; Shunsuke Yuzuriha

    2010-01-01

    Yohei Tanaka1,2, Kiyoshi Matsuo1, Shunsuke Yuzuriha11Department of Plastic and Reconstructive Surgery, Shinshu University School of Medicine, Matsumoto, Japan; 2Clinica Tanaka Plastic and Reconstructive Surgery and Anti-aging Center, Matsumoto, JapanBackground and objective: Our previous histological studies indicated that near-infrared (NIR) irradiation stimulates collagen proliferation in rat and human skin for 3 months. High collagen density in the dermis and smoothing of the epidermis wer...

  4. Acceleration of the Meckel Syndrome by Near-Infrared Light Therapy

    OpenAIRE

    Lim, Jinhwan; Gattone, Vincent H.; Sinders, Rachel; Miller, Caroline A.; Liang, Yun; Harris, Peter; Watkins, John B; Henshel, Diane S.

    2011-01-01

    Background/Aims Phototherapy using a narrow-band, near-infrared (NIR) light (using a light-emitting diode, LED) is being used to treat certain medical conditions. This narrow-band red light has been shown to stimulate cytochrome c oxidase (CCO) in mitochondria that would stimulate ATP production and has the ability to stimulate wound healing. LED treatment also decreases chemical-induced oxidative stress in tested systems. As renal cystic diseases are known to have evidence of oxidative stres...

  5. Wireless near-infrared spectroscopy of skeletal muscle oxygenation and hemodynamics during exercise and ischemia

    OpenAIRE

    Shadgan, Babak; Reid, W. Darlene; Gharakhanlou, Reza; Stpublisher-ids, Lynn; Macnab, Andrew John

    2009-01-01

    The majority of in vivo applications of near-infrared spectroscopic (NIRS) monitoring use continuous wave instruments that require a fiberoptic cable connection between the subject and the instrument during monitoring. In studies of muscle physiology where subjects are exercising, and particularly in those who are engaged in sports activity, a wireless instrument with telemetric capacity provides obvious advantages. Having access to reliable telemetric NIRS technology will also increase the p...

  6. Intraoperative evaluation of revascularization effect on ischemic muscle hemodynamics using near-infrared diffuse optical spectroscopies

    OpenAIRE

    Yu, Guoqiang; Shang, Yu; Zhao, Youquan; Cheng, Ran; Dong, Lixin; Saha, Sibu P

    2011-01-01

    Arterial revascularization in patients with peripheral arterial disease (PAD) reestablishes large arterial blood supply to the ischemic muscles in lower extremities via bypass grafts or percutaneous transluminal angioplasty (PTA). Currently no gold standard is available for assessment of revascularization effects in lower extremity muscles. This study tests a novel near-infrared diffuse correlation spectroscopy flow-oximeter for monitoring of blood flow and oxygenation changes in medial gastr...

  7. Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

    KAUST Repository

    Jiao, Chongjun

    2011-07-15

    Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

  8. Gold/Chitosan Nanocomposites with Specific Near Infrared Absorption for Photothermal Therapy Applications

    OpenAIRE

    Guandong Zhang; Xinghua Sun; Jacek Jasinski; Dhruvin Patel; Gobin, Andre M

    2012-01-01

    Gold/chitosan nanocomposites were synthesized and evaluated as a therapeutic agent for the photothermal therapy. Gold nanoparticles (Au NPs) with controllable optical absorption in the near infrared (NIR) region were prepared by the reaction of chloroauric acid and sodium thiosulfate. To apply these particles to cancer therapy, the bare Au NPs were coated with chitosan (CS), O-carboxymethyl chitosan (CMCS), and a blend of CS and CMCS for utilizations in physiologic conditions. The surface pro...

  9. Classification of change detection and change blindness from near-infrared spectroscopy signals

    OpenAIRE

    Tanaka, Hirokazu; Katura, Takusige

    2011-01-01

    Using a machine-learning classification algorithm applied to near-infrared spectroscopy (NIRS) signals, we classify a success (change detection) or a failure (change blindness) in detecting visual changes for a change-detection task. Five subjects perform a change-detection task, and their brain activities are continuously monitored. A support-vector-machine algorithm is applied to classify the change-detection and change-blindness trials, and correct classification probability of 70–90% is o...

  10. Regression models based on new local strategies for near infrared spectroscopic data.

    Science.gov (United States)

    Allegrini, F; Fernández Pierna, J A; Fragoso, W D; Olivieri, A C; Baeten, V; Dardenne, P

    2016-08-24

    In this work, a comparative study of two novel algorithms to perform sample selection in local regression based on Partial Least Squares Regression (PLS) is presented. These methodologies were applied for Near Infrared Spectroscopy (NIRS) quantification of five major constituents in corn seeds and are compared and contrasted with global PLS calibrations. Validation results show a significant improvement in the prediction quality when local models implemented by the proposed algorithms are applied to large data bases. PMID:27496996

  11. Near-Infrared Quantum Dots as Optical Probes for Tumor Imaging

    OpenAIRE

    Gao, Jinhao; Chen, Xiaoyuan; Cheng, Zhen

    2010-01-01

    Molecular imaging plays a key role in personalized medicine, which is the goal and future of patient management. Among the various molecular imaging modalities, optical imaging may be the fastest growing area for bioanalysis, and the major reason is the research on fluorescence semiconductor quantum dots (QDs) and dyes have evolved over the past two decades. The great efforts on the synthesis of QDs with fluorescence emission from UV to near-infrared (NIR) regions speed up the studies of QDs ...

  12. Objective assessment of skin rejuvenation using near-infrared 1064-nm neodymium: YAG laser in Asians

    OpenAIRE

    Tanaka Y.; Matsuo K; Yuzuriha S

    2011-01-01

    Yohei Tanaka1,2, Kiyoshi Matsuo1, Shunsuke Yuzuriha11Department of Plastic and Reconstructive Surgery, Shinshu University School of Medicine, Matsumoto, Japan; 2Clinica Tanaka Plastic and Reconstructive Surgery and Anti-aging Center, Matsumoto, JapanBackground: We reported previously that near-infrared (NIR) irradiation provides long-lasting stimulation of elastin, and is efficient for skin rejuvenation. Many studies have indicated the efficacy of various types of laser, but did not include s...

  13. Multispectral Near-Infrared Imaging of Composite Restorations in Extracted Teeth

    OpenAIRE

    Logan, Cooper M.; Co, Katrina U.; Fried, William A.; Simon, Jacob C.; Staninec, Michal; and, Daniel Fried; Darling, Cynthia L.

    2014-01-01

    One major advantage of composite restoration materials is that they can be color matched to the tooth. However, this presents a challenge when composites fail and they need to be replaced. Dentists typically spend more time repairing and replacing composites than placing new restorations. Previous studies have shown that near-infrared imaging can be used to distinguish between sound enamel and decay due to the differences in light scattering. The purpose of this study was to use a similar app...

  14. Passive tumor targeting and imaging by using mercaptosuccinic acid-coated near-infrared quantum dots

    OpenAIRE

    Lin, Guimiao

    2015-01-01

    Guimiao Lin,1 Xiaomei Wang,1 Feng Yin,2 Ken-Tye Yong2 1The Engineering Lab of Synthetic Biology and Research Institute of Uropoiesis and Reproduction, School of Medicine, Shenzhen University, Shenzhen, People’s Republic of China; 2School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore Abstract: In this paper, we demonstrate the preparation of monodispersed quantum dots (QDs) as near-infrared (NIR) optical probes for in vivo pancreati...

  15. A New Multi-wavelength Solar Telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)

    OpenAIRE

    Fang, C.; Chen, P. F.; Li, Z.; Ding, M. D.; Dai, Y.; X. Y. Zhang; Mao, W. J.; J. P. Zhang; T. Li; Liang, Y J; Lu, H T

    2013-01-01

    A new multi-wavelength solar telescope, Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, was constructed, being fabricated by Nanjing Institute of Astronomical Optics & Technology and run in cooperation with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He {\\small I} 10830 \\AA, H$\\alpha$, and white-light at 3600 \\AA and 4250 \\AA, which are selected in order to obtain the dynamics in the corona, chromosphere, and th...

  16. Modelling Cerebrovascular Reactivity: A Novel Near-Infrared Biomarker of Cerebral Autoregulation?

    OpenAIRE

    Highton, D.; Panovska-Griffiths, J; Ghosh, A; Tachtsidis, I; Banaji, M.; Elwell, C.; Smith, M.

    2013-01-01

    Understanding changes in cerebral oxygenation, haemodynamics and metabolism holds the key to individualised, optimised therapy after acute brain injury. Near-infrared spectroscopy (NIRS) offers the potential for non-invasive, continuous bedside measurement of surrogates for these processes. Interest has grown in applying this technique to interpret cerebrovascular pressure reactivity (CVPR), a surrogate of the brain's ability to autoregulate blood flow. We describe a physiological model-based...

  17. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

    OpenAIRE

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

    2013-01-01

    Abstract. Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detecte...

  18. Determination of Hemicellulose, Cellulose and Lignin in Moso Bamboo by Near Infrared Spectroscopy

    OpenAIRE

    Xiaoli Li; Chanjun Sun; Binxiong Zhou; Yong He

    2015-01-01

    The contents of hemicellulose, cellulose and lignin are important for moso bamboo processing in biomass energy industry. The feasibility of using near infrared (NIR) spectroscopy for rapid determination of hemicellulose, cellulose and lignin was investigated in this study. Initially, the linear relationship between bamboo components and their NIR spectroscopy was established. Subsequently, successive projections algorithm (SPA) was used to detect characteristic wavelengths for establishing th...

  19. Noncollinear parametric amplification in the near-infrared based on type-II phase matching

    OpenAIRE

    Schmidt, Christian; Bühler, Johannes; Heinrich, Alexander-Cornelius; Leitenstorfer, Alfred; Brida, Daniele

    2015-01-01

    Noncollinear parametric amplification based on type-II phase matching for the generation of ultrabroadband and tunable spectra in the near infrared is investigated. In a noncollinear geometry the group velocity matching condition between signal and idler can be obtained in frequently used crystals such as β-barium borate (BBO) even for wavelengths fully located in the anomalous dispersion region. The extremely broadband operation, peculiar tuning possibilities and straightforward experimental...

  20. Level-set algorithm for the reconstruction of functional activation in near-infrared spectroscopic imaging

    OpenAIRE

    Jacob, Mathews; Bresler, Yoram; Toronov, Vlad; Zhang, Xiaofeng; Webb, Andrew

    2006-01-01

    We introduce a new algorithm for the reconstruction of functional brain activations from near-infrared spectroscopic imaging (NIRSI) data. While NIRSI offers remarkable biochemical specificity, the attainable spatial resolution with this technique is rather limited, mainly due to the highly scattering nature of brain tissue and the low number of measurement channels. Our approach exploits the support-limited (spatially concentrated) nature of the activations to make the reconstruction problem...

  1. Quality evaluation of regional forage resources by means of near infrared reflectance spectroscopy

    OpenAIRE

    Bruno Ronchi; Umberto Bernabucci; Paolo Carlini; Pier Paolo Danieli

    2010-01-01

    Quality parameters of grassland and pasture samples collected during a three-year period at two environmentally andgeographically different areas were analysed by Near Infrared Reflectance Spectroscopy (NIRS). Chemical analysis forcrude protein (CP), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL)and crude ash (ASH) carried out on two-thirds of the samples were used in calibration processes. The remaining onethirdof the data was used to...

  2. Rapid and Accurate Evaluation of the Quality of Commercial Organic Fertilizers Using Near Infrared Spectroscopy

    OpenAIRE

    Chang Wang; Chichao Huang; Jian Qian; Jian Xiao; Huan Li; Yongli Wen; Xinhua He; Wei Ran; Qirong Shen; Guanghui Yu

    2014-01-01

    The composting industry has been growing rapidly in China because of a boom in the animal industry. Therefore, a rapid and accurate assessment of the quality of commercial organic fertilizers is of the utmost importance. In this study, a novel technique that combines near infrared (NIR) spectroscopy with partial least squares (PLS) analysis is developed for rapidly and accurately assessing commercial organic fertilizers quality. A total of 104 commercial organic fertilizers were collected fro...

  3. Sensitivity of Hemoglobin Concentration on Optical Probe Positioning in Image-guided Near Infrared Spectroscopy

    OpenAIRE

    Srinivasan, Subhadra; Carpenter, Colin; Pogue, Brian W.

    2009-01-01

    Multi-modality image-guided near infrared spectroscopy provides volume-based quantification of total hemoglobin, oxygen saturation, water and scatter in various tissue types in-vivo. The accuracy of these parameters depends on the location of the imaging probe and its distance from the tumor. In a numerical study, we have performed simulation to analyze this effect in a breast-specific imaging domain. Results show that the accuracy of total hemoglobin decreases by 25% for every centimeter awa...

  4. Three dimensional water vapour visualization in porous packing by near-infrared diffuse transmittance tomography

    OpenAIRE

    Aiouache, Farid; Hardacre, Christopher; de Sa, J.; Fernandes, D.L.A.; Kitagawa, K; Nic an tSaoir, Meabh

    2012-01-01

    Near-infrared diffuse tomography was used in order to observe dynamic behaviour of flowing gases by measuring the 3D distributions of composition and temperature in a weakly scattering packed bed reactor, subject to wall effects and non-isothermal conditions. The technique was applied to the vapour phase hydrogen isotopic exchange reaction in a hydrophobic packing of low aspect ratio made of platinum on styrene divinyl benzene sulphonate copolymer resin. The results of tomography revealed une...

  5. Investigation of tolerances of diffractive optical elements for the high power near infrared lasers

    International Nuclear Information System (INIS)

    The deformations due to thermal expansion of a binary diffractive grating in fused silica under near infrared high power laser exposure are estimated by a Finite Element Method. They are compared to the geometrical tolerances obtained by a rigorous electromagnetic method which is used to calculate the optical performances. It is shown that the grating deformations remain below the geometrical tolerances for an average laser power of up to 1 kW and an exposition of up to 100 s

  6. GEMINI near-infrared spectroscopic observations of young massive stars embedded in molecular clouds

    OpenAIRE

    Roman-Lopes, A.; Abraham, Z.; R Ortiz; Rodrigues-Ardila, A.

    2008-01-01

    K-band spectra of young stellar candidates in four southern hemisphere clusters have been obtained with the near-infrared spectrograph GNIRS in Gemini South. The clusters are associated with IRAS sources that have colours characteristic of ultracompact HII regions. Spectral types were obtained by comparison of the observed spectra with those of a NIR library; the results include the spectral classification of nine massive stars and seven objects confirmed as background late-type stars. Two of...

  7. Indocyanine Green Enhanced Near Infrared Laser Treatment of Murine Mammary Carcinoma

    OpenAIRE

    SHAFIRSTEIN, GAL; Bäumler, Wolfgang; Hennings, Leah J.; Siegel, Eric R.; Friedman, Ran; Mauricio A Moreno; Webber, Jessica; Jackson, Cassie; Griffin, Robert J.

    2011-01-01

    It is well accepted that near-infrared (NIR) lasers are appropriate to ablate benign lesions and induce irreversible thermal injury in deeply seated blood vessels. At this wavelength, the laser light penetrates deep (3–5 mm) into the skin. However, many researchers have reported noticeable pain, extending from mild to severe, during and immediately following NIR laser treatment. Intravenous administration of an exogenous chromophore (indocyanine green, ICG, dye) can effectively convert NIR la...

  8. Near infrared spectroscopy for frontal lobe oxygenation during non-vascular abdominal surgery

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Grocott, Hilary P; Secher, Niels H

    2015-01-01

    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......; mini-mental state examination) and reduced LOS (14 versus 23 days) were seen. Also, during liver transplantation (LTx), impaired cerebral autoregulation (25%), cerebral deoxygenation in the anhepatic phase (36%) and cerebral hyperoxygenation with reperfusion of the grafted liver (14%) were identified...

  9. Photon sorting in the near field using subwavelength cavity arrays in the near-infrared

    International Nuclear Information System (INIS)

    A frequency selective metasurface capable of sorting photons in the near-infrared spectral range is designed, fabricated, and characterized. The metasurface, a periodic array of dielectric cylindrical cavities in a gold film, localizes and transmits light of two spectral frequency bands into spatially separated cavities, resulting in near-field light splitting. The design and fabrication methodologies of the metasurface are discussed. The transmittance and photon sorting properties of the designed structure is simulated numerically and the measured transmission is presented

  10. Glucosamine-Bound Near-Infrared Fluorescent Probes with Lysosomal Specificity for Breast Tumor Imaging1

    OpenAIRE

    Li, Cong; Greenwood, Tiffany R; Glunde, Kristine

    2008-01-01

    Noninvasive imaging of lysosomes will be useful 1) to elucidate the role of lysosomal parameters in cancer, 2) to diagnose malignant lesions, and 3) to evaluate future lysosome-targeted anticancer therapies. Lysosome-specific labeling of glucosamine-bound near-infrared (NIR) fluorescent probes, IR-1 and IR-2, but not control probe IR-15 without the glucosamine moiety, was observed by fluorescence microscopy in human breast epithelial cell lines. Lysosome labeling and tumor specificity of thes...

  11. Glucosamine-Bound Near-Infrared Fluorescent Probes with Lysosomal Specificity for Breast Tumor Imaging

    OpenAIRE

    Cong Li; Greenwood, Tiffany R; Kristine Glunde

    2008-01-01

    Noninvasive imaging of lysosomes will be useful 1) to elucidate the role of lysosomal parameters in cancer, 2) to diagnose malignant lesions, and 3) to evaluate future lysosome-targeted anticancer therapies. Lysosome-specific labeling of glucosamine-bound near-infrared (NIR) fluorescent probes, IR-1 and IR-2, but not control probe IR-15 without the glucosamine moiety, was observed by fluorescence microscopy in human breast epithelial cell lines. Lysosome labeling and tumor specificity of thes...

  12. Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

    OpenAIRE

    Brunet, Didier; Woignier, Thierry; Lesueur-Jannoyer, M.; R. Achard; Rangon, Luc; Barthès, Bernard

    2009-01-01

    Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q(2) = 0.75, R-2 = 0.8...

  13. Social inclusion enhances biological motion processing: A functional near-infrared spectroscopy study

    OpenAIRE

    Bolling, Danielle Z.; Pelphrey, Kevin A.; Kaiser, Martha D.

    2012-01-01

    Humans are especially tuned to the movements of other people. Neural correlates of this social attunement have been proposed to lie in and around the right posterior superior temporal sulcus (STS) region, which robustly responds to biological motion in contrast to a variety of non-biological motions. This response persists even when no form information is provided, as in point-light displays (PLDs). The aim of the current study was to assess the ability of functional near-infrared spectroscop...

  14. Near-Infrared Imaging of Injured Tissue in Living Subjects using IR-820

    OpenAIRE

    Prajapati, Suresh I.; Martinez, Carlo O.; Ali N. Bahadur; Wu, Isabel Q; Zheng, Wei; Lechleiter, James D.; McManus, Linda M.; Chisholm, Gary B; Joel E. Michalek; Shireman, Paula K.; Keller, Charles

    2009-01-01

    The unprecedented increase in pre-clinical studies necessitates high-throughput, inexpensive and straightforward methods for evaluating diseased tissues. Near-infrared imaging of live subjects is a versatile, cost-effective technology that can be effectively used in a variety of pathological conditions. We have characterized an inexpensive optoelectronic chemical, IR-820, as an infrared blood pool contrast agent to detect and quantify diseased tissue in live animals. IR-820 has maximal excita...

  15. Near infrared radiation rescues mitochondrial dysfunction in cortical neurons after oxygen-glucose deprivation

    OpenAIRE

    Yu, Zhanyang; Liu, Ning; Zhao, Jianhua; Li, Yadan; McCarthy, Thomas J.; Tedford, Clark E; Lo, Eng H.; Wang, Xiaoying

    2014-01-01

    Near infrared radiation (NIR) is known to penetrate and affect biological systems in multiple ways. Recently, a series of experimental studies suggested that low intensity NIR may protect neuronal cells against a wide range of insults that mimic diseases such as stroke, brain trauma and neuro-degeneration. However, the potential molecular mechanisms of neuroprotection with NIR remain poorly defined. In this study, we tested the hypothesis that low intensity NIR may attenuate hypoxia/ischemia-...

  16. ARNICA and LonGSp: the refurbishment of two near infrared instruments

    Science.gov (United States)

    Koshida, Shintaro; Vanzi, Leonardo; Guzman, Dani; Leiva, Rodrigo; Bonati, Marco A.; Avilés, Roberto L.; Baffa, Carlo; Palla, Francesco; Mannucci, Filippo; Shen, Tzu Chiang; Suc, Vincent

    2014-07-01

    ARNICA and LonGSp are two NICMOS based near infrared instruments developed in the 90's by the Astrophysical Observatory of Arcetri. After more than 10 years from decommissioning we refurbished the two instruments with a new read-out electronics and control software. We present the performances of the refurbished systems and compare them with the historic behavior. Both instruments are currently used for testing purposes in the Lab and at the telescope, we present some example applications.

  17. Efficient near-infrared up-conversion photoluminescence in carbon nanotubes

    OpenAIRE

    Akizuki, Naoto; Aota, Shun; Mouri, Shinichiro; Matsuda, Kazunari; Miyauchi, Yuhei

    2015-01-01

    Photoluminescence phenomena normally obey Stokes' law of luminescence according to which the emitted photon energy is typically lower than its excitation counterparts. Here we show that carbon nanotubes break this rule under one-photon excitation conditions. We found that the carbon nanotubes exhibit efficient near-infrared photoluminescence upon photoexcitation even at an energy lying >100–200 meV below that of the emission at room temperature. This apparently anomalous phenomenon is attribu...

  18. The physiological origin of task-evoked systemic artefacts in functional near infrared spectroscopy

    OpenAIRE

    Kirilina, Evgeniya; Jelzow, Alexander; Heine, Angela; Niessing, Michael; Wabnitz, Heidrun; Brühl, Rüdiger; Ittermann, Bernd; Jacobs, Arthur M.; Tachtsidis, Ilias

    2012-01-01

    A major methodological challenge of functional near-infrared spectroscopy (fNIRS) is its high sensitivity to haemodynamic fluctuations in the scalp. Superficial fluctuations contribute on the one hand to the physiological noise of fNIRS, impairing the signal-to-noise ratio, and may on the other hand be erroneously attributed to cerebral changes, leading to false positives in fNIRS experiments. Here we explore the localisation, time course and physiological origin of task-evoked superficial si...

  19. MUC1 aptamer based near infrared fluorescence probes for tumor diagnosis

    Science.gov (United States)

    Zhao, Juan; Ma, Yuxiang; Cui, Sisi; Cao, Jie; Achilefu, Samuel; Gu, Yueqing

    2013-02-01

    Mucin 1 (MUC1) is a cell surface mucin broadly expressed in mucosal tissues. The aberrant expression of MUC1 under-glycosylated forms has been reported in various carcinomas of the epithelium, such as breast, pancreatic and ovarian cancers. Using the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) methodology, aptamers previously selected against MUC1 glycoprotein with high affinities and specificities. In this study, we developed two targeted near-infrared fluorescent probes for tumor in-vivo diagnostics using a MUC1 aptamer(APT) as targeted ligand and near-infrared fluorescent dye (ICG-Der-02) as labelling. MUC1 aptamer conjugated ICG-Der-02 (APT-ICG-Der-02) displayed a great selectivity to MUC1 positive cell line MCF7 and MCF7 xenograft-bearing nude mice. To improve the high targeting of the probe to the tumor cells, PEG, with high biocompatibility, non immunogenicity and long circulation, was conjugated to the probe .The new probe (APT-PEG-ICG-Der-02) showed better tumour uptake and clearance, and also displayed a great selectivity to MCF7 tumor-bearing nude mice. Data obtained demonstrate a high potential of the targeted near-infrared fluorescent probes in cancer early diagnosis.

  20. Exploration of in vivo Effect Assessment Factor Monitoring by Near-infrared Spectroscopy during LITT

    Energy Technology Data Exchange (ETDEWEB)

    Qian Aiping; Hua Guoran; Zhang Hua [Department of Biomedical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Qian Zhiyu, E-mail: huagr@ntu.edu.cn

    2011-02-01

    By studying the variation trends of the absorption coefficient ({mu}{sub a}) and the reduced scattering coefficient ({mu}'{sub s}), which were monitored in vivo by functional near infrared spectroscopy (fNIRS) system in real time during laser induced interstitial thermotherapy (LITT), the optimized near infrared effect assessment factor would be explored. In vivo measurements of the absorption coefficient (u{sub a}) and the reduced scattering coefficient (u'{sub s}) were performed with a functional near infrared spectroscopy system during LITT. Fresh porcine liver tissue samples in vitro and the subcutaneous implanted rat liver cancers were examined in different laser doses and define heating times. The absorption coefficient obtained by the fNIRS increased in the pork liver experiments, but decreased in the rat liver cancer experiments. The reduced scattering coefficient increased in the pork liver experiments and the rat liver cancer experiments, it increased quickly at beginning, and gradually reached the stable state. Therefore, the reduced scattering coefficient is more suitable for reflecting the progress of damage during different biological tissues' LITT than the absorption coefficient. This conclusion will effectively guide the study of suitable therapy effect assessment system during LITT in real time.

  1. Ultra-deep GEMINI near-infrared observations of the bulge globular cluster NGC 6624

    CERN Document Server

    Saracino, S; Ferraro, F R; Geisler, D; Mauro, F; Lanzoni, B; Origlia, L; Miocchi, P; Cohen, R E; Villanova, S; Bidin, C Moni

    2016-01-01

    We used ultra-deep $J$ and $K_s$ images secured with the near-infrared GSAOI camera assisted by the multi-conjugate adaptive optics system GeMS at the GEMINI South Telescope in Chile, to obtain a ($K_s$, $J-K_s$) color-magnitude diagram (CMD) for the bulge globular cluster NGC 6624. We obtained the deepest and most accurate near-infrared CMD from the ground for this cluster, by reaching $K_s$ $\\sim$ 21.5, approximately 8 magnitudes below the horizontal branch level. The entire extension of the Main Sequence (MS) is nicely sampled and at $K_s$ $\\sim$ 20 we detected the so-called MS "knee" in a purely near-infrared CMD. By taking advantage of the exquisite quality of the data, we estimated the absolute age of NGC 6624 ($t_{age}$ = 12.0 $\\pm$ 0.5 Gyr), which turns out to be in good agreement with previous studies in the literature. We also analyzed the luminosity and mass functions of MS stars down to M $\\sim$ 0.45 M$_{\\odot}$ finding evidence of a significant increase of low-mass stars at increasing distances f...

  2. Near-infrared dichroism of a mesogenic transition metal complex and its solubility in nematic hosts

    International Nuclear Information System (INIS)

    A transition metal complex possessing the nematic phase, bis (p-n-butylstyryl-1, 2-dithiolato) nickel, was synthesized and its optical properties and solubility in the nematic hosts K15 and MBBA were investigated. The metal complex displayed a high solubility in both host materials (up to 10% wt/wt) and a strong near-infrared absorption band centered at 860 nm. A blocking extinction of greater than OD = 3 was obtained with a 100 micron pathlength of a 0.5% wt/wt mixture of the nematic metal complex in K15, suggesting its usefulness for passive blocking of near infrared radiation. A 24 micron thick, homogeneously aligned guest-host cell containing a 1% wt/wt mixture of the metal complex in K15 possessed a contrast ratio of nearly 5:1 and a blocking extinction of OD = 3.5 at 860 nm, demonstrating for the first time the existence of near-infrared dichroism in this class of materials. The solubility and blocking extinction of the mesogenic metal complex in K15 was considerably superior to the non-mesogenic near ir laser dye bis(dimethylaminodithiobenzil) nickel in the same host. An interaction of the nematic metal complex in mixtures with MBBA which resulted in the creation of a new absorption band at 1050 nm was also observed. 21 refs., 9 figs

  3. Herbig Stars' Near-Infrared Excess: An Origin in the Protostellar Disk's Magnetically-Supported Atmosphere

    CERN Document Server

    Turner, N J; Dullemond, C P; Hirose, S

    2013-01-01

    Young stars with masses 2-8 Suns, called the Herbig Ae and Be stars, often show a near-infrared excess too large to explain with a hydrostatically-supported circumstellar disk of gas and dust. At the same time the accretion flow carrying the circumstellar gas to the star is thought to be driven by magneto-rotational turbulence, which according to numerical MHD modeling yields an extended low-density atmosphere supported by the magnetic fields. We demonstrate that the base of the atmosphere can be optically-thick to the starlight and that the parts lying near 1 AU are tall enough to double the fraction of the stellar luminosity reprocessed into the near-infrared. We generate synthetic spectral energy distributions (SEDs) using Monte Carlo radiative transfer calculations with opacities for sub-micron silicate and carbonaceous grains. The synthetic SEDs closely follow the median Herbig SED constructed recently by Mulders and Dominik, and in particular match the large near-infrared flux, provided the grains have ...

  4. Authentication of cow feeding and geographic origin on milk using visible and near-infrared spectroscopy.

    Science.gov (United States)

    Coppa, M; Martin, B; Agabriel, C; Chassaing, C; Sibra, C; Constant, I; Graulet, B; Andueza, D

    2012-10-01

    The ability of near-infrared spectroscopy to trace cow feeding systems and farming altitude was tested on 486 bulk milk samples from France and northwestern Italy. Milks were grouped into feeding systems according to the main forage in the diet. Partial least square discriminant analysis correctly classified 95.5, 91.5, and 93.3% of pasture versus maize silage, hay, and fermented herbage feeding systems, respectively. Discrimination was slightly less successful when diets with large proportions of the nondominant forage were included in each group. Near-infrared spectroscopy correctly discriminated no-pasture from pasture milk, even with only 30% of pasture in the diet (5.4% cross-validation error), and the error stabilized when pasture exceeded 70% (2.5% error). Near-infrared spectroscopy did not reliably trace milk geographic origin when the feeding system effect was isolated from the altitude effect. These findings may be usefully exploited for the authentication of dairy products. PMID:22901470

  5. Optimizing Strontium Ruthenate Thin Films for Near-Infrared Plasmonic Applications

    Science.gov (United States)

    Braic, Laurentiu; Vasilantonakis, Nikolaos; Zou, Bin; Maier, Stefan A.; Alford, Neil Mcn.; Zayats, Anatoly V.; Petrov, Peter K.

    2015-03-01

    Several new plasmonic materials have recently been introduced in order to achieve better temperature stability than conventional plasmonic metals and control field localization with a choice of plasma frequencies in a wide spectral range. Here, epitaxial SrRuO3 thin films with low surface roughness fabricated by pulsed laser deposition are studied. The influence of the oxygen deposition pressure (20-300 mTorr) on the charge carrier dynamics and optical constants of the thin films in the near-infrared spectral range is elucidated. It is demonstrated that SrRuO3 thin films exhibit plasmonic behavior of the thin films in the near-infrared spectral range with the plasma frequency in 3.16-3.86 eV range and epsilon-near-zero wavelength in 1.11-1.47 μm range that could be controlled by the deposition conditions. The possible applications of these films range from the heat-generating nanostructures in the near-infrared spectral range, to metamaterial-based ideal absorbers and epsilon-near-zero components, where the interplay between real and imaginary parts of the permittivity in a given spectral range is needed for optimizing the spectral performance.

  6. Noninvasive measurement of postocclusive parameters in human forearm blood by near infrared spectroscopy

    Science.gov (United States)

    Rao, K. Prahlad; Radhakrishnan, S.; Reddy, M. Ramasubba

    2005-04-01

    Near infrared (NIR) light in the wavelength range from 700 to 900 nm can pass through skin, bone and other tissues relatively easily. As a result, NIR techniques allow a noninvasive assessment of hemoglobin saturation for a wide range of applications, such as in the study of muscle metabolism, the diagnosis of vascular disorders, brain imaging, and breast cancer detection. Near infrared Spectroscopy (NIRS) is an effective tool to measure the hemoglobin concentration in the tissues, which can discriminate optically the oxy- and deoxy- hemoglobin species because of their different near-infrared absorption spectra. We have developed an NIRS probe consisting of a laser diode of 830 nm wavelength and a PIN photodiode in reflectance mode. We have selected a set of healthy volunteers (mean age 30, range 26-40 years) for the study. The probe is placed on forearm of each subject and the backscattered light intensity is measured by occluding the blood flow at 210, 110 and 85 mmHg pressures. Recovery time, peak time and time after 50% release of the cuff pressure are determined from the optical densities during the post occlusive state of forearm. These parameters are useful for determining the transient increase in blood flow after the release of blood occlusion. Clinically, the functional aspects of blood flow in the limbs could be evaluated noninvasively by NIRS.

  7. Efficiency improvement by near infrared quantum dots for luminescent solar concentrators

    Science.gov (United States)

    Wang, Chunhua; Shcherbatyuk, Georgiy; Inman, Richard; Pelka, Dave; Zhang, Weiya; Rodriguez, Yvonne; Carter, Sue; Winston, Roland; Ghosh, Sayantani

    2010-08-01

    Quantum dot (QD) luminescent solar concentrator (LSC) uses a sheet of highly transparent materials doped with luminescent QDs materials. Sunlight is absorbed by these quantum dots and emitted through down conversion process. The emitted light is trapped in the sheet and travels to the edges where it can be collected by photovoltaic solar cells. In this study, we investigate the performance of LSCs fabricated with near infrared QDs (lead sulfide) and compared with the performance of LSCs containing normal visible QDs (CdSe/ZnS), and LSCs containing organic dye (Rhodamine B). Effects of materials concentrations (related to re-absorption) on the power conversion efficiency are also analyzed. The results show that near infrared QDs LSCs can generate nearly twice as much as the output current from normal QDs and organic dye LSCs. This is due to their broad absorption spectra. If stability of QDs is further improved, the near infrared QDs will dramatically improve the efficiency of LSCs for solar energy conversion with lower cost per Wp.

  8. Quantitative Determination of Germinability of Puccinia striiformis f. sp. tritici Urediospores Using Near Infrared Spectroscopy Technology

    Directory of Open Access Journals (Sweden)

    Yaqiong Zhao

    2015-01-01

    Full Text Available Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst is an important disease on wheat. In this study, quantitative determination of germinability of Pst urediospores was investigated by using near infrared reflectance spectroscopy (NIRS combined with quantitative partial least squares (QPLS and support vector regression (SVR. The near infrared spectra of the urediospore samples were acquired using FT-NIR MPA spectrometer and the germination rate of each sample was measured using traditional spore germination method. The best QPLS model was obtained with vector correction as the preprocessing method of the original spectra and 4000–12000 cm−1 as the modeling spectral region while the modeling ratio of the training set to the testing set was 4 : 1. The best SVR model was built when vector normalization was used as the preprocessing method, the modeling ratio was 5 : 1 and the modeling spectral region was 8000–11000 cm−1. The results showed that the effect of the best model built using QPLS or SVR was satisfactory. This indicated that quantitative determination of germinability of Pst urediospores using near infrared spectroscopy technology is feasible. A new method based on NIRS was provided for rapid, automatic, and nondestructive determination of germinability of Pst urediospores.

  9. Near-infrared reflectance bull’s eye maculopathy as an early indication of hydroxychloroquine toxicity

    Directory of Open Access Journals (Sweden)

    Wong KL

    2015-03-01

    Full Text Available Keye L Wong,1 Scott E Pautler,2 David J Browning31Retina Associates of Sarasota, Sarasota, FL, USA; 2Retina Vitreous Associates of Florida, Tampa, FL, USA; 3Charlotte Eye Ear Nose and Throat Associates, Charlotte, NC, USAImportance: In some patients, hydroxychloroquine ocular toxicity may progress even following cessation of therapy. Any leverage the clinician may use to allow earlier detection may avert significant vision loss.Observation: We report three cases suggesting that bull’s eye maculopathy seen on near-infrared reflectance with a confocal scanning laser ophthalmoscope could be an early, objective manifestation of hydroxychloroquine ocular toxicity, and with progression of the disease this near-infrared “bull’s eye” change may disappear.Conclusion and relevance: Alerting clinicians to this observation may allow a larger case series to corroborate the hypothesis that bull’s eye maculopathy detected by near-infrared reflectance may represent an early sign of hydroxychloroquine toxicity.Keywords: confocal, scanning laser ophthalmoscope, multifocal ERG

  10. Near-infrared reddening of extra-galactic GMCs in a face-on geometry

    CERN Document Server

    Kainulainen, Jouni; Alves, Joao

    2008-01-01

    [Abridged] We describe the near-infrared reddening signature of giant molecular clouds (GMCs) in external galaxies. In particular, we examine the E(J-H) and E(H-K) color-excesses, and the effective extinction law observed in discrete GMC regions. We also study the effect of the relative scale height of the GMC distribution to the color-excesses, and to the observed mass function of GMCs. We perform Monte Carlo radiative transfer simulations with 3D models of stellar radiation and clumpy dust distributions, resembling a face-on geometry. The scattered light is included in the models, and near-infrared color maps are calculated from the simulated data. The effective near-infrared reddening law, i.e. the ratio E(J-H)/E(H-K), has a value close to unity in GMC regions. The ratio depends on the relative scale height of GMCs, xi, and for xi values 0.1...0.75 we find the typical ratios of 0.6...1.1. The effective extinction law turns out to be very flat in GMC regions. We find the ratios of apparent extinctions of A(...

  11. Blood species identification using Near-Infrared diffuse transmitted spectra and PLS-DA method

    Science.gov (United States)

    Zhang, Linna; Zhang, Shengzhao; Sun, Meixiu; Wang, Zhennan; Li, Hongxiao; Li, Yingxin; Li, Gang; Lin, Ling

    2016-05-01

    Blood species identification is of great significance for blood supervision and wildlife investigations. The current methods used to identify the blood species are destructive. Near-Infrared spectroscopy method is known for its non-invasive properties. In this research, we combined Near-Infrared diffuse transmitted spectra and Partial Least Square Discrimination Analysis (PLS-DA) to identify three blood species, including macaque, human and mouse. Blind test and external test were used to assess the PLS-DA model. The model performed 100% accuracy in its identification between three blood species. This approach does not require a specific knowledge of biochemical features for each individual class but relies on a spectroscopic statistical differentiation of the whole components. This is the first time to demonstrate Near-Infrared diffuse transmitted spectra have the ability to identify the species of origin of blood samples. The results also support a good potential of absorption and scattering spectroscopy for species identification in practical applications for real-time detection.

  12. Preparation and near-infrared reflective characterization of Cu-doped sodium zincophosphate

    International Nuclear Information System (INIS)

    Cu-doped sodium zincophosphate [NaZn1-x(Cu)xPO4; x=0.05, 0.10, 0.15, and 0.20] powders were prepared by a coprecipitation method for the use as a dark heat-reflective material. The weighted average of the reflectance was calculated according to the reflectivity data measured using a UV-visible and near-infrared spectrophotometer. The measurement wavelength region was 380-2500 nm. The visible and near-infrared reflective properties of NaZn1-x(Cu)xPO4 doped with different amounts of Cu at varied calcination temperatures were investigated. NaZn(Cu)PO4 was found to be the main phase that crystallized in a monoclinic system of NaZn0.9(Cu)0.1PO4 at 800 °C. The sample of NaZn0.9(Cu)0.1PO4 was black in the visible region because of its high absorption, and its weighted average reflectance reached 51% in the near-infrared region. As a result, NaZn1-x(Cu)xPO4 has potential applications as a dark heat-reflective material.

  13. Near-Infrared Quantum Cutting in Yb3+ Doped SrMoO4 Phosphors.

    Science.gov (United States)

    Luo, Xiaobing; Shen, Jun; Huang, He; Xu, Lu; Wang, Zhixiang; Chen, Yang; Li, Li

    2016-04-01

    Efficient near-infrared (NIR) quantum cutting (QC) has been demonstrated in Yb3+ doped SrMoO4 phosphors synthesized by the high-temperature solid-state reaction method. The obtained SrMoO4:Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra and decay lifetime to understand the observed near-infrared quantum cutting phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of SrMoO4 and exhibit good crystallinity. The experimental results showed that the strong visible molybdate (MoO2-(4)) emission around 493 nm and near-infrared (NIR) emission around 1000 nm from Yb3+(2F(5/2)-->2F(7/2)) of SrMoO4:Yb3+ phosphors were observed under ultraviolet (290 nm) excitation. The Yb + concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches as high as 10 mol%. The cooperative energy transfer (CET) mechanism was also discussed in detail. The broadband NIR QC phosphors may possibly have potential application in enhancing the conversion efficiency of solar cells. PMID:27451655

  14. In vivo visualization and quantification of collecting lymphatic vessel contractility using near-infrared imaging.

    Science.gov (United States)

    Chong, Chloé; Scholkmann, Felix; Bachmann, Samia B; Luciani, Paola; Leroux, Jean-Christophe; Detmar, Michael; Proulx, Steven T

    2016-01-01

    Techniques to image lymphatic vessel function in either animal models or in the clinic are limited. In particular, imaging methods that can provide robust outcome measures for collecting lymphatic vessel function are sorely needed. In this study, we aimed to develop a method to visualize and quantify collecting lymphatic vessel function in mice, and to establish an in vivo system for evaluation of contractile agonists and antagonists using near-infrared fluorescence imaging. The flank collecting lymphatic vessel in mice was exposed using a surgical technique and a near-infrared tracer was infused into the inguinal lymph node. Collecting lymphatic vessel contractility and valve function could be easily visualized after the infusion. A diameter tracking method was established and the diameter of the vessel was found to closely correlate to near-infrared fluorescence signal. Phasic contractility measures of frequency and amplitude were established using an automated algorithm. The methods were validated by tracking the vessel response to topical application of a contractile agonist, prostaglandin F2α, and by demonstrating the potential of the technique for non-invasive evaluation of modifiers of lymphatic function. These new methods will enable high-resolution imaging and quantification of collecting lymphatic vessel function in animal models and may have future clinical applications. PMID:26960708

  15. An atlas of bright star spectra in the near infrared from Cassini-VIMS

    CERN Document Server

    Stewart, Paul N; Nicholson, Philip D; Sloan, G C; Hedman, Matthew M

    2015-01-01

    We present the Cassini Atlas Of Stellar Spectra (CAOSS), comprised of near-infrared low-resolution spectra of bright stars recovered from space-based observations by the Cassini spacecraft. The 65 stellar targets in the atlas are predominately M, K and S giants. However it also contains spectra of other bright nearby stars including carbon stars and main sequence stars from A to F. The spectra presented are free of all spectral contamination caused by the Earth's atmosphere, including the detrimental telluric molecular bands which put parts of the near-infrared spectrum out of reach of terrestrial observations. With a single instrument, a spectro-photometric dataset is recovered that spans the near-infrared from 0.8 to 5.1 microns with spectral resolution ranging from R=53.5 to R=325. Spectra have been calibrated into absolute flux units after careful characterisation of the instrumental spectral efficiency. Spectral energy distributions for most stars match closely with literature values. All final data prod...

  16. Near-infrared-to-near-infrared down-shifting and upconversion luminescence of KY3F10 with single dopant of Nd3+ ion

    Science.gov (United States)

    Lin, Huihong; Yu, Ting; Tsang, Ming-Kiu; Bai, Gongxun; Zhang, Qinyuan; Hao, Jianhua

    2016-01-01

    We have studied the structural and near-infrared (NIR) luminescent properties of KY3F10 phosphors, singly doped with Nd3+ serving as both sensitizer and activator. With a single laser diode at the wavelength of 808 nm as a pump source, simultaneous NIR-to-NIR upconversion (UC) and down-shifting (DS) emissions are effectively achieved, due to the specific energy levels of Nd3+ dopant and the low phonon energy of the host. The luminescence mechanism related to energy transfer is discussed. The luminescence can be modulated through controlling the population of Nd3+:4F3/2 state in our experiment. Interestingly, both UC and DS emissions of the material fall within the dual biological window, suggesting that the prepared phosphors have potential applications in the bioimaging field.

  17. Near-infrared-to-near-infrared down-shifting and upconversion luminescence of KY3F10 with single dopant of Nd3+ ion

    International Nuclear Information System (INIS)

    We have studied the structural and near-infrared (NIR) luminescent properties of KY3F10 phosphors, singly doped with Nd3+ serving as both sensitizer and activator. With a single laser diode at the wavelength of 808 nm as a pump source, simultaneous NIR-to-NIR upconversion (UC) and down-shifting (DS) emissions are effectively achieved, due to the specific energy levels of Nd3+ dopant and the low phonon energy of the host. The luminescence mechanism related to energy transfer is discussed. The luminescence can be modulated through controlling the population of Nd3+:4F3/2 state in our experiment. Interestingly, both UC and DS emissions of the material fall within the dual biological window, suggesting that the prepared phosphors have potential applications in the bioimaging field

  18. Ceramic with zircon coating

    Science.gov (United States)

    Wang, Hongyu (Inventor)

    2003-01-01

    An article comprises a silicon-containing substrate and a zircon coating. The article can comprise a silicon carbide/silicon (SiC/Si) substrate, a zircon (ZrSiO.sub.4) intermediate coating and an external environmental/thermal barrier coating.

  19. Near-infrared luminescence of Tm{sup 3+}-doped CeO{sub 2} films based on silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xue; Wang, Shenwei; Li, Ling; Mu, Guangyao; Huang, Miaoling; Yi, Lixin [Beijing Jiaotong University, Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing (China)

    2016-02-15

    CeO{sub 2}/Tm{sub 2}O{sub 3} multilayer films were deposited on silicon substrates by electron-beam evaporation. Tm{sup 3+} ions were doped in CeO{sub 2} after the films were annealed in oxygen atmosphere at 1000 C. The doping concentration of Tm{sup 3+} varies in the range of 0.1-3 mol%. A series of near-infrared emission peaks were observed under the excitation of 330 nm, which correspond to {sup 1}G{sub 4}-{sup 3}H{sub 5}, {sup 3}H{sub 4}-{sup 3}H{sub 6}, {sup 1}G{sub 4}-{sup 3}H{sub 4}, {sup 3}H{sub 5}-{sup 3}H{sub 6}, {sup 3}F{sub 2}-{sup 3}H{sub 5}, {sup 3}H{sub 4}-{sup 3}F{sub 4}, {sup 1}G{sub 4}-{sup 3}F{sub 3,2} and {sup 3}F{sub 4}-{sup 3}H{sub 6} transitions of Tm{sup 3+}, respectively. The dominant transition of {sup 3}H{sub 4}-{sup 3}H{sub 6} near 805 nm was within optical transmission window. The luminescence properties and the crystal structure of CeO{sub 2}:Tm{sup 3+} films were investigated by excitation and emission spectroscopy and X-ray diffraction. Meanwhile, the substitution process of Ce{sup 4+} by Tm{sup 3+} was illustrated, and lattice expansion of the matrix CeO{sub 2} gave rise to the increase in FWHM of CeO{sub 2} diffraction peaks. In addition, the effect of Tm{sup 3+} concentration on photoluminescence was also studied, and the optimal concentration of Tm{sup 3+} was 0.5 mol%. (orig.)

  20. 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 was...

  1. Near-infrared fundus autofluorescence-visualized melanin in the choroidal abnormalities of neurofibromatosis type 1

    Directory of Open Access Journals (Sweden)

    Ueda-Consolvo T

    2012-07-01

    Full Text Available Tomoko Ueda-Consolvo, Akio Miyakoshi, Hironori Ozaki, Satoshi Houki, Atsushi HayashiDepartment of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, JapanPurpose: To report a series of three cases of neurofibromatosis type 1 examined by near-infrared fundus autofluorescence (NIR-AF with a scanning laser ophthalmoscope and spectral-domain optical coherence tomography (OCT to show the characteristics of choroidal abnormalities.Methods: Retrospective case series. Six eyes of three patients were examined by conventional fundus examinations, near-infrared monochromatic light reflectance (NIR-R and NIR-AF, OCT, fluorescein angiography, and indocyanine green angiography.Results: All eyes showed multiple bright patchy regions in the choroid of the posterior pole with NIR-R. NIR-AF revealed high fluorescent regions of similar sizes at fundus locations identical to those shown by NIR-R. In one case, hypofluorescent regions were shown by indocyanine green angiography in the bright fluorescent region shown by NIR-AF. The other two cases showed no abnormality under conventional fundus examination or fluorescein angiography. OCT images crossing the bright patchy region showed irregular hyper-reflectivity in the choroid in two cases and hyporeflectivity in one case.Conclusions: NIR-AF demonstrated that dense melanin was included in the choroidal nodules of neurofibromatosis type 1. The choroidal nodules showed hyper- or hyporeflectivity in the choroid on OCT, which did not affect the retinal structure.Keywords: near-infrared fundus autofluorescence, neurofibromatosis type 1, choroidal nodule, melanin

  2. Ischemia monitoring in off-pump coronary artery bypass surgery using intravascular near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Zerkowski Hans-Reinhard

    2006-05-01

    Full Text Available Abstract Background In off-pump coronary artery bypass surgery, manipulations on the beating heart can lead to transient interruptions of myocardial oxygen supply, which can generate an accumulation of oxygen-dependent metabolites in coronary venous blood. The objective of this study was to evaluate the reliability of intravascular near-infrared spectroscopy as a monitoring method to detect possible ischemic events in off-pump coronary artery bypass procedures. Methods In 15 elective patients undergoing off-pump myocardial revascularization, intravascular near-infrared spectroscopic analysis of coronary venous blood was performed. NIR signals were transferred through a fiberoptic catheter for signal emission and collection. For data analysis and processing, a miniature spectrophotometer with multivariate statistical package was used. Signal acquisition and analysis were performed before and after revascularization. Spectroscopic data were compared with hemodynamic parameters, electrocardiogram, transesophageal echocardiography and laboratory findings. Results A conversion to extracorporeal circulation was not necessary. The mean number of grafts per patient was 3.1 ± 0.6. An intraoperative myocardial ischemia was not evident, as indicated by electrocardiogram and transesophageal echocardiography. Continuous spectroscopic analysis showed reproducible absorption spectra of coronary sinus blood. Due to uneventful intraoperative courses, clear ischemia-related changes could be detected in none of the patients. Conclusion Our initial results show that intravascular near-infrared spectroscopy can reliably be used for an online intraoperative ischemia monitoring in off-pump coronary artery bypass surgery. However, the method has to be further evaluated and standardized to determine the role of spectroscopy in off-pump coronary artery bypass surgery.

  3. 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.

  4. Diffuse reflectance near infrared-chemometric methods development and validation of amoxicillin capsule formulations

    Science.gov (United States)

    Khan, Ahmed Nawaz; Khar, Roop Krishen; Ajayakumar, P. V.

    2016-01-01

    Objective: The aim of present study was to establish near infrared-chemometric methods that could be effectively used for quality profiling through identification and quantification of amoxicillin (AMOX) in formulated capsule which were similar to commercial products. In order to evaluate a large number of market products easily and quickly, these methods were modeled. Materials and Methods: Thermo Scientific Antaris II near infrared analyzer with TQ Analyst Chemometric Software were used for the development and validation of the identification and quantification models. Several AMOX formulations were composed with four excipients microcrystalline cellulose, magnesium stearate, croscarmellose sodium and colloidal silicon dioxide. Development includes quadratic mixture formulation design, near infrared spectrum acquisition, spectral pretreatment and outlier detection. According to prescribed guidelines by International Conference on Harmonization (ICH) and European Medicine Agency (EMA) developed methods were validated in terms of specificity, accuracy, precision, linearity, and robustness. Results: On diffuse reflectance mode, an identification model based on discriminant analysis was successfully processed with 76 formulations; and same samples were also used for quantitative analysis using partial least square algorithm with four latent variables and 0.9937 correlation of coefficient followed by 2.17% root mean square error of calibration (RMSEC), 2.38% root mean square error of prediction (RMSEP), 2.43% root mean square error of cross-validation (RMSECV). Conclusion: Proposed model established a good relationship between the spectral information and AMOX identity as well as content. Resulted values show the performance of the proposed models which offers alternate choice for AMOX capsule evaluation, relative to that of well-established high-performance liquid chromatography method. Ultimately three commercial products were successfully evaluated using developed

  5. Visualization and prediction of porosity in roller compacted ribbonswith near infrared chemical imaging (NIR-CI)

    DEFF Research Database (Denmark)

    Khorasani, Milad Rouhi; Amigo Rubio, Jose Manuel; Sonnergaard, Jørn;

    2015-01-01

    reference methods that ribbons compressed at a higher pressure resulted in a lower mean porosity. Using NIR-CI in combination with multivariate data analysis it was possible to visualize and predict the porosity distribution of the ribbons. This approach is considered important for process monitoring and......The porosity of roller compacted ribbon is recognized as an important critical quality attribute which has a huge impact on the final product quality. The purpose of this study was to investigate the use of near-infrared chemical imaging (NIR-CI) for porosity estimation of ribbons produced at...

  6. Near-infrared micro-variability of radio-loud quasars

    OpenAIRE

    Whiting, Matthew; Oshlack, Alicia; Webster, Rachel

    2001-01-01

    We observed three AGN from the Parkes Half-Jansky Flat-spectrum Sample at near-infrared (NIR) wavelengths to search for micro-variability. In one source, the blue quasar PKS 2243-123, good evidence for NIR micro-variability was found. In the other two sources, PKS 2240-260 and PKS 2233-148, both BL Lacertae objects, no such evidence of variability was detected. We discuss the implications of these observations for the various mechanisms that have been proposed for micro-variability.

  7. Near-Infrared Synchrotron Emission from the Compact Jet of GX 339-4

    OpenAIRE

    Corbel, S.; Fender, R. P.

    2002-01-01

    We have compiled contemporaneous broadband observations of the black hole candidate X-ray binary GX 339-4 when in the low/hard X-ray state in 1981 and 1997. The data clearly reveal the presence of two spectral components, with thermal and non-thermal spectra, overlapping in the optical -- near-infrared bands. The non-thermal component lies on an extrapolation of the radio spectrum of the source, and we interpret it as optically thin synchrotron emission from the powerful, compact jet in the s...

  8. Room-Temperature Near-Infrared Electroluminescence from Boron-Diffused Silicon Pn-Junction Diodes

    OpenAIRE

    Li, Si; Gao, Yuhan; Fan, Ruixin; Li, Dongsheng; Yang, Deren

    2015-01-01

    Silicon pn-junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL) was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 μm (0.78 eV) was observed besides the band-to-band line (~1.1 eV) under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was observed. ...

  9. Room-temperature near-infrared electroluminescence from boron-diffused silicon pn junction diodes

    OpenAIRE

    Si eLi; Yuhan eGao; Ruixin eFan; Dongsheng eLi; Deren eYang

    2015-01-01

    Silicon pn junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski (CZ) n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL) was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 m (0.78 eV ) was observed besides the band-to-band line (~1.1eV) under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was obser...

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

    International Nuclear Information System (INIS)

    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

  11. Near-infrared surface-enhanced Raman spectroscopy: New developments and applications

    Energy Technology Data Exchange (ETDEWEB)

    Angel, S.M.; Myrick, M.L.

    1989-01-01

    The surface-enhanced Raman phenomenon was discovered in 1974 and analytical applications of it are only now being developed. Near-infrared surface-enhanced Raman spectroscopy was first reported in 1988, and the characteristics of the technique are still being determined. The purpose of this paper is to introduce the reader to the technique and to describe some of its characteristics. In addition, some of the applications being explored by the authors, including remote monitoring of groundwater contaminants and qualitative assays for drugs, are presented. 61 refs., 12 figs.

  12. Euclid near infrared spectrophotometer instrument concept and first test results at the end of phase B

    OpenAIRE

    2014-01-01

    The Euclid mission objective is to understand why the expansion of the Universe is accelerating by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020. The NISP (Near Infrared Spectro-Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (0.9-2µm) as a photometer and spect...

  13. Near Infrared Optical Projection Tomography for Assessments of β-cell Mass Distribution in Diabetes Research

    OpenAIRE

    Eriksson, Anna U; Svensson, Christoffer; Hörnblad, Andreas; Cheddad, Abbas; Kostromina, Elena; Eriksson, Maria; Norlin, Nils; Pileggi, Antonello; Sharpe, James; Georgsson, Fredrik; Alanentalo, Tomas; Ahlgren, Ulf

    2013-01-01

    By adapting OPT to include the capability of imaging in the near infrared (NIR) spectrum, we here illustrate the possibility to image larger bodies of pancreatic tissue, such as the rat pancreas, and to increase the number of channels (cell types) that may be studied in a single specimen. We further describe the implementation of a number of computational tools that provide: 1/ accurate positioning of a specimen's (in our case the pancreas) centre of mass (COM) at the axis of rotation (AR)2; ...

  14. ANIR : Atacama Near-Infrared Camera for the 1.0-m miniTAO Telescope

    OpenAIRE

    Konishi, Masahiro; Motohara, Kentaro; Tateuchi, Ken; TAKAHASHI, Hidenori; Kitagawa, Yutaro; Kato, Natsuko; Sako, Shigeyuki; Uchimoto, Yuka K.; Toshikawa, Koji; Ohsawa, Ryou; Yamamuro, Tomoyasu; Asano, Kentaro; Ita, Yoshifusa; Kamizuka, Takafumi; Komugi, Shinya

    2015-01-01

    We have developed a near-infrared camera called ANIR (Atacama Near-InfraRed camera) for the University of Tokyo Atacama Observatory 1.0m telescope (miniTAO) installed at the summit of Cerro Chajnantor (5640 m above sea level) in northern Chile. The camera provides a field of view of 5'.1 $\\times$ 5'.1 with a spatial resolution of 0".298 /pixel in the wavelength range of 0.95 to 2.4 $\\mu$m. Taking advantage of the dry site, the camera is capable of hydrogen Paschen-$\\alpha$ (Pa$\\alpha$, $\\lamb...

  15. In Vivo Fluorescence Imaging in the Second Near-Infrared Window Using Carbon Nanotubes.

    Science.gov (United States)

    Hong, Guosong; Dai, Hongjie

    2016-01-01

    In vivo fluorescence imaging in the second near-infrared window (NIR-II window, 1000-1700 nm) is a powerful imaging technique that emerged in recent years. This imaging tool allows for noninvasive, deep-tissue visualization and interrogation of anatomical features and functions with improved imaging resolution and contrast at greater tissue penetration depths than traditional fluorescence imaging. Here, we present the detailed protocol for conducting NIR-II fluorescence imaging in live animals, including the procedures for preparation of biocompatible and NIR-II fluorescent carbon nanotube solution, live animal administration and NIR-II fluorescence image acquisition. PMID:27283426

  16. 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.

  17. Visualization of Anatomical Information in Near-Infrared Imaging for Robotic Urological Surgery

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Minnillo, Brian; Taylor, Russels;

    2011-01-01

    Commercial telerobotic surgery systems for soft tissue surgery are generally limited to visual imaging, though it is possible to simultaneously view picture-in-picture visualization of another workstation. However, it is not easy to correlate such information with the primary endoscopic view since...... it may not relate to the surface visible in the visual endoscopic images. As critical surfaces as well as surgical targets often lie subsurface, a range of techniques (e.g. ultrasound and near-infrared imaging) and registration methods have been investigated as robotic surgery gains popularity. While...

  18. A near infrared test for two recent luminosity functions for galaxies

    CERN Document Server

    Zaninetti, L

    2014-01-01

    Two recent luminosity function (LF) for galaxies are reviewed and the parameters which characterize the near infrared are fixed. A first LF is a modified Schechter LF with four parameters. The second LF is derived from the generalized gamma and has four parameters. The formulas which give the number of galaxies as function of the redshift are reviewed and a special attention is given to the position of the photometric maximum which is expressed as function of a critical parameter or the flux of radiation or the apparent magnitude. A simulation of the 2MASS Redshift Survey is given in the framework of the non Poissonian Voronoi Tessellation.

  19. High-resolution near-infrared imaging of the Orion 114-426 silhouette disk

    OpenAIRE

    McCaughrean, Mark J.; Chen, Hua; Bally, John; Erickson, Ed; Thompson, Rodger; Rieke, Marcia; Schneider, Glenn; Stolovy, Susan; Young, Erick

    1997-01-01

    We present the first high-resolution near-infrared images of the edge-on silhouette circumstellar disk, Orion 114-426, made using NICMOS on the Hubble Space Telescope. Images taken against the bright nebular background of the ionized hydrogen Pa$\\alpha$ line at 1.87 micron show the major axis of the disk to be approximately 20% smaller than at 0.6 micron, from which we deduce the structure of the edge of the disk. Continuum images of diffuse polar lobes above and below the plane of the disk s...

  20. Mechanism of oxidative stress generation in cells by localized near-infrared femtosecond laser excitation

    Science.gov (United States)

    He, Hao; Chan, Kam Tai; Kong, Siu Kai; Lee, Rebecca Kit Ying

    2009-12-01

    We examined the effect of femtosecond (fs) and continuous wave (CW) lasers at near-infrared range on the creation of reactive oxygen species in a human liver cancer cell line. By controlling the mitochondria electron transport chain (ETC), it was found that a major part of the oxidative stress was generated by the laser induced thermal effect on the mitochondria while the remaining part was created by direct free electron liberation by the fs pulses, which could be observed after breaking the ETC. The study helps clarify the major effects produced on animal cells when excited by fs lasers.

  1. Use of near infrared spectroscopy for assessment of beef quality traits

    Directory of Open Access Journals (Sweden)

    L. Gallo

    2010-04-01

    Full Text Available Chemical and physical traits and fatty acid composition of meat samples from 148 Piemontese beef samples were predicted by near infrared spectroscopy. Coefficients of determination in calibration (R2 ranged between 0.44 and 0.99 for chemical composition and between 0.02 and 0.98 for fatty acid (FA profile, being in general more accurate for the major FA. The calibration results gave inaccurate prediction for cholesterol and collagen content and for most physical traits, such as Warner-Bratzler shear force, cooking loss, drip loss, colour (L, a, b and pH.

  2. Ultrathin polarizing films for the near-infrared region consisting of stacked anisotropic gold island films

    Science.gov (United States)

    Takakuwa, Makoto; Baba, Kazutaka; Miyagi, Mitsunobu

    1996-08-01

    We have fabricated an ultrathin polarizing film for the near-infrared region by stretching a periodic multilayer consisting of gold island layers and glass layers. A polarizing film with an extinction ratio of 21.5 dB and a thickness of \\similar 0.2 mu m has been realized at the wavelength of 1300 nm by use of a periodic multilayer of 12 gold island layers with a mass thickness of 21 nm. This polarizing film could be useful as a micropolarizer for fiber-embedded in-line optical devices and hybrid integrated optics.

  3. meso-Substituted bisanthenes as soluble and stable near-infrared dyes

    KAUST Repository

    Li, Jinling

    2010-02-05

    (Chemical Equation Presented) Three meso-substituted bisanthenes, 4-6, were prepared in a short synthetic route from the bisanthenequinone. They exhibit largely improved stability and solubility in comparison to the parent bisanthene. All of these compounds also show near-infrared (NIR) absorption and emission with high to moderate fluorescence quantum yields. Amphoteric redox behavior was observed for 4-6 by cyclic voltammetry, and these compounds can be reversibly oxidized and reduced into respective cationic and anionic species by both electrochemical and chemical processes. In addition, compound 5 adopts a herringbone π-stacking motif in the single crystal. © 2010 American Chemical Society.

  4. Near infrared observations of galaxies in the Coma supercluster and in the cancer cluster. II

    International Nuclear Information System (INIS)

    We present new near infrared observations of 110 galaxies in the Coma/A1367 supercluster region, and 40 galaxies in the Cancer cluster. These observations are part of an on-going investigation of the properties of normal galaxies and of their near-IR emission, which aims at obtaining homogeneous, multifrequency data for a large sample of galaxies in different density environments. The addition of these observations to the sample presented in Gavazzi and Trinchieri raises the number of Coma/A1367 galaxies with near-IR data to 275. Our measurements, together with data published by Bothun et al, give a sample of 45 spirals in the Cancer cluster

  5. A near infrared organic photodiode with gain at low bias voltage

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Ian H [Los Alamos National Laboratory; Crone, Brian K [Los Alamos National Laboratory

    2009-01-01

    We demonstrate an organic photodiode with near infrared optical response out to about 1100 run with a gain of {approx}10 at 1000 run under 5V reverse bias. The diodes employ a soluble naphthalocyanine with a peak absorption coefficient of {approx}10{sup 5} cm{sup -1} at 1000 nm. In contrast to most organic photodiodes, no exciton dissociating material is used. At zero bias, the diodes are inefficient with an external quantum efficiency of {approx} 10{sup -2}. In reverse bias, large gain occurs and is linear with bias voltage above 4V. The observed gain is consistent with a photoconductive gain mechanism.

  6. Size controlled near-infrared high-quality PbSe quantum dots

    International Nuclear Information System (INIS)

    Herein, we report the size controlled preparation of PbSe quantum dots (QDs) by non coordinating solvent route using oleic acid as surfactant molecules. The particles size is controlled by varying temperature and time of reaction. The present method of synthesis gives highly stable colloids, spherical in shape, better size tunability, narrow size distribution, extremely small size, monodisperse and exhibit strong near-infrared emission. The estimated particles sizes are in the range of 2 to 8 nm. These PbSe quantum dots are used for applications in optoelectronics and biological imaging

  7. Ternary I–III–VI Quantum Dots Luminescent in the Red to Near Infrared

    OpenAIRE

    Allen, Peter M.; Bawendi, Moungi G.

    2008-01-01

    We report the synthesis of a size series of copper indium selenide quantum dots (QDs) of various stoichiometries exhibiting photoluminescence (PL) from the red to near infrared (NIR). The synthetic method is modular and we have extended it to the synthesis of luminescent silver indium diselenide QDs. Previous reports on QDs luminescent in the NIR region have been primarily restricted to binary semiconductor systems, such as InAs, PbS, and CdTe. This work seeks to expand the availability of lu...

  8. Size controlled near-infrared high-quality PbSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kalasad, M. N., E-mail: mnkalasad@gmail.com [Dept. of Physics, SDM College of Engineering & Technology, Dharwad-580003 (India); Rabinal, M. K.; Mulimani, B. G. [Department of Physics, Karnatak University, Dharwad-580003 (India); Greenham, N. C. [Cavendish Laboratory, Dept. of Physics, University of Cambridge, Cambridge CB3 OHE United Kingdom (United Kingdom)

    2015-06-24

    Herein, we report the size controlled preparation of PbSe quantum dots (QDs) by non coordinating solvent route using oleic acid as surfactant molecules. The particles size is controlled by varying temperature and time of reaction. The present method of synthesis gives highly stable colloids, spherical in shape, better size tunability, narrow size distribution, extremely small size, monodisperse and exhibit strong near-infrared emission. The estimated particles sizes are in the range of 2 to 8 nm. These PbSe quantum dots are used for applications in optoelectronics and biological imaging.

  9. Enhanced near-infrared absorption in graphene with multilayer metal-dielectric-metal nanostructure.

    Science.gov (United States)

    Zhang, Lei; Tang, Linlong; Wei, Wei; Cheng, Xinlu; Wang, Wei; Zhang, Hong

    2016-09-01

    A multilayer metal-dielectric-metal nanostructure is proposed to enhance the absorption in graphene in a near-infrared region. The main feature of the structure is the generation of strong magnetic response within the dielectric spacer, which is directly related to absorption enhancement in graphene to over 22 times higher than that of free-standing monolayer graphene. We also show that absorption enhancement in graphene can be easily controlled by adjusting the geometry of the propose structure. The simple structural configuration and the flexible tunability in absorption enhancement are beneficial for practical fabrication and future applications in graphene-based active optoelectronic devices. PMID:27607608

  10. High-power, continuous-wave optical parametric oscillators from visible to near-infrared

    OpenAIRE

    Samanta, Goutam Kumar

    2009-01-01

    This thesis presents the development of a new class of high-power, continuous-wave (cw) optical parametric oscillators (OPOs) with extended tunability from visible to near-infrared (near-IR). While lasers have been in use for nearly 50 years, it is still difficult to develop laser systems that can cover many regions of the optical spectrum, from ultraviolet (UV) and visible to the near and mid-infrared wavelength range, with potential applications in the fields such as spectroscopy, remote se...

  11. Spectroscopy of fullerenes, fulleranes and PAHs in the UV, visible and near infrared spectral range

    OpenAIRE

    F. Cataldo; Garcia-Hernandez, D. A.; Manchado, A.; Iglesias-Groth, S.

    2013-01-01

    The spectra of fullerenes C60 and C70, higher fullerenes C76, C78 and C84 and hydrogenated fullerenes (fulleranes) were studied in laboratory in the UV and in the visible spectral range and could be used for searching and recognizing these molecules in space. Furthermore, the radical cation spectra of all the mentioned fullerene series and also of a series of large and very large polycyclic aromatic hydrocarbons (PAHs) were generated in laboratory and studied in the near infrared spectral range.

  12. FAST TRACK COMMUNICATION: Selective inactivation of human immunodeficiency virus with subpicosecond near-infrared laser pulses

    Science.gov (United States)

    Tsen, K. T.; Tsen, Shaw-Wei D.; Hung, Chien-Fu; Wu, T.-C.; Kiang, Juliann G.

    2008-06-01

    We demonstrate for the first time that human immunodeficiency virus (HIV) can be inactivated by irradiation with subpicosecond near-infrared laser pulses at a moderate laser power density. By comparing the threshold laser power density for the inactivation of HIV with those of human red blood cells and mouse dendritic cells, we conclude that it is plausible to use the ultrashort pulsed laser to selectively inactivate blood-borne pathogens such as HIV while leaving sensitive materials like human red blood cells unharmed. This finding has important implications in the development of a new laser technology for disinfection of viral pathogens in blood products and in the clinic.

  13. Determination of the protein content in brine from salted herring using near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Svensson, V.T.; Nielsen, Henrik Hauch; Bro, Rasmus

    2004-01-01

    Near-infrared reflectance (NIR) spectroscopy in the spectral range of 1000-2500 nm, was measured directly on brine from barrel salted herring, to investigate the potential of NIR as a fast method to determine the protein content. A principal component analysis performed on the NIR spectra shows two...... clearly indicate that NIR spectroscopy has a potential as a fast and noninvasive method for assessing the protein content in brine from barrel salted herring, which again may be used as an indicator for the ripening quality of barrel salted herring....

  14. Low frequency oscillations in cephalic vessels assessed by near infrared spectroscopy

    DEFF Research Database (Denmark)

    Phillip, Dorte; Schytz, Henrik W; Selb, Juliette;

    2012-01-01

    BACKGROUND AND METHODS: Low frequency oscillations (LFO) of cerebral vessels are believed to reflect cerebral autoregulation. We investigated day-to-day and hemispheric variations in 0.1 Hz LFO with near infrared spectroscopy (NIRS) and transcranial Doppler (TCD) to determine phase shift and gain...... of oxygenated haemoglobin (oxyHb) and the velocity of the middle cerebral artery (Vmca) to the arterial blood pressure (ABP). The direct left-right phase shifts of oxyHb and Vmca were also assessed. We examined 44 healthy volunteers by simultaneous recordings of ABP, oxyHb and Vmca during spontaneous...

  15. Development of a near infrared fluorescence catheter: operating characteristics and feasibility for atherosclerotic plaque detection

    International Nuclear Information System (INIS)

    We present a one-dimensional optical fibre-based imaging catheter specifically developed for the atherosclerotic plaque detection of emerging novel near infrared fluorescence imaging agents. We show that femtomole amounts of fluorochromes can be detected, especially in the presence of a blood-free medium. We further studied the catheter responses for a wide range of laser powers and biologically relevant concentrations of fluorochrome. In vitro tissue-like phantoms and human carotid plaque specimen measurements further demonstrate the feasibility of atherosclerotic plaque detection

  16. Noncollinear parametric amplification in the near-infrared based on type-II phase matching

    Science.gov (United States)

    Schmidt, C.; Bühler, J.; Heinrich, A.-C.; Leitenstorfer, A.; Brida, D.

    2015-09-01

    Noncollinear parametric amplification based on type-II phase matching for the generation of ultrabroadband and tunable spectra in the near infrared is investigated. In a noncollinear geometry the group velocity matching condition between signal and idler can be obtained in frequently used crystals such as β-barium borate (BBO) even for wavelengths fully located in the anomalous dispersion region. The extremely broadband operation, peculiar tuning possibilities and straightforward experimental implementation with the standard BBO crystal pave the way for a versatile NIR source in ultrafast spectroscopy.

  17. First Evidence of Near-Infrared Photonic Bandgap in Polymeric Rod-Connected Diamond Structure

    CERN Document Server

    Chen, Lifeng; Zheng, Xu; Lin, Jia-De; Oulton, Ruth; Lopez-Garcia, Martin; Ho, Ying-Lung D; Rarity, John G

    2015-01-01

    We present the simulation, fabrication, and optical characterization of low-index polymeric rod-connected diamond (RCD) structures. Such complex three-dimensional photonic crystal structures are created via direct laser writing by two-photon polymerization. To our knowledge, this is the first measurement at near-infrared wavelengths, showing partial photonic bandgaps. We characterize structures in transmission and reflection using angular resolved Fourier image spectroscopy to visualize the band structure. Comparison of the numerical simulations of such structures with the experimentally measured data show good agreement for both P- and S-polarizations.

  18. Enhanced near-infrared responsivity of silicon photodetector by the impurity photovoltaic effect

    Institute of Scientific and Technical Information of China (English)

    袁吉仁; 黄海宾; 邓新华; 梁晓军; 周耐根; 周浪

    2015-01-01

    The near-infrared responsivity of a silicon photodetector employing the impurity photovoltaic (IPV) effect is inves-tigated with a numerical method. The improvement of the responsivity can reach 0.358 A/W at a wavelength of about 1200 nm, and its corresponding quantum efficiency is 41.1%. The origin of the enhanced responsivity is attributed to the absorption of sub-bandgap photons, which results in the carrier transition from the impurity energy level to the con-duction band. The results indicate that the IPV effect may provide a general approach to enhancing the responsivity of photodetectors.

  19. Selective inactivation of human immunodeficiency virus with subpicosecond near-infrared laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Tsen, K T [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States); Tsen, S-W D; Hung, C-F; Wu, T-C [Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21231 (United States); Kiang, Juliann G [Scientific Research Department, Armed Forces Radiobiology Research Institute, Uniformed Services University of The Health Sciences, Bethesda, MD 20889-5603 (United States)

    2008-06-25

    We demonstrate for the first time that human immunodeficiency virus (HIV) can be inactivated by irradiation with subpicosecond near-infrared laser pulses at a moderate laser power density. By comparing the threshold laser power density for the inactivation of HIV with those of human red blood cells and mouse dendritic cells, we conclude that it is plausible to use the ultrashort pulsed laser to selectively inactivate blood-borne pathogens such as HIV while leaving sensitive materials like human red blood cells unharmed. This finding has important implications in the development of a new laser technology for disinfection of viral pathogens in blood products and in the clinic. (fast track communication)

  20. Southern near-infrared photometric monitoring of Galactic young star clusters (NIP of Stars)

    OpenAIRE

    Barbá, R.; Morrell, N; 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, an...

  1. The Application of the Edge Sharpening Operator to the Breast Near-Infrared Imaging

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The principles of Gradient operator, Laplacian operator, LOG operator and Sobel operator are discussed. Certain features of breast can be extracted in different degrees and aspects from original images by applying four edge sharpening operators to the breast near-infrared imaging. A great number of cases prove that compared with the other three operators, the improved Sobel operator can effectively extract the structural features of the breast from an original image. It can be concluded that the improved Sobel operator can assist in diagnosing breast diseases.

  2. The VISTA near-infrared YJKs public survey of the Magellanic Clouds System (VMC)

    OpenAIRE

    Cioni, M. R.; Clementini, G.; et al, ...

    2011-01-01

    The VISTA public survey project VMC targets the Large Magellanic Cloud, the Small Magellanic Cloud, the Bridge and two fields in the Stream. The VMC survey is a uniform and homogeneous survey in the Y, J and Ks near-infrared filters. The main goals are the determination of the star formation history and the three-dimensional structure of the Magellanic system. The survey is therefore designed to reach stars as faint as the oldest main sequence turn-off point and to constrain the mean magnitud...

  3. Standard reference for instrument response function in fluorescence lifetime measurements in visible and near infrared

    Science.gov (United States)

    Chib, Rahul; Shah, Sunil; Gryczynski, Zygmunt; Fudala, Rafal; Borejdo, Julian; Zelent, Bogumil; Corradini, Maria G.; Ludescher, Richard D.; Gryczynski, Ignacy

    2016-02-01

    Allura red (AR) fluorophore, a common dye in the food industry, displays a broad emission spectrum in water (visible-to-near infrared region of the electromagnetic spectrum) and has a remarkably short fluorescence lifetime of about 10 ps. This short lifetime does not depend on the emission (observation) wavelength. We examined time responses of AR fluorescence across emission wavelengths from 550 nm to 750 nm and found that it is an ideal candidate for impulse response functions in fluorescence lifetime measurements.

  4. Extraction of heart rate from functional near-infrared spectroscopy in infants

    OpenAIRE

    Perdue, Katherine L.; Westerlund, Alissa; McCormick, Sarah A.; Nelson, Charles A.

    2014-01-01

    Changes in heart rate are a useful physiological measure in infant studies. We present an algorithm for calculating the heart rate (HR) from oxyhemoglobin pulsation in functional near-infrared spectroscopy (fNIRS) signals. The algorithm is applied to data collected from 10 infants, and the HR derived from the fNIRS signals is compared against the HR as calculated by electrocardiography. We show high agreement between the two HR signals for all infants (r>0.90), and also compare stimulus-relat...

  5. Extraction of heart rate from functional near-infrared spectroscopy in infants

    OpenAIRE

    Perdue, Katherine L.; Westerlund, Alissa; McCormick, Sarah A.; Nelson, Charles A.

    2014-01-01

    Changes in heart rate are a useful physiological measure in infant studies. We present an algorithm for calculating the heart rate (HR) from oxyhemoglobin pulsation in functional near-infrared spectroscopy (fNIRS) signals. The algorithm is applied to data collected from 10 infants, and the HR derived from the fNIRS signals is compared against the HR as calculated by electrocardiography. We show high agreement between the two HR signals for all infants (r > 0.90), and also compare stimulus-rel...

  6. The Structure of Molecular Clouds: I - All Sky Near Infrared Extinction Maps

    OpenAIRE

    Rowles, J; Froebrich, D.

    2009-01-01

    We are studying the column density distribution of all nearby giant molecular clouds. As part of this project we generated several all sky extinction maps. They are calculated using the median near infrared colour excess technique applied to data from the Two Micron All-Sky Survey (2MASS). Our large scale approach allows us to fit spline functions to extinction free regions in order to accurately determine the colour excess values. Two types of maps are presented: i) Maps with a constant nois...

  7. Near infrared electrochromic variable optical attenuator based on ruthenium complex and polycrystalline tungsten oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jidong; WU Xianguo; YU Hongan; YAN Donghang; WANG Zhiyuan

    2005-01-01

    A near infrared (NIR) electrochromic attenuator based on a dinuclear ruthenium complex and polycrystalline tungsten oxide was fabricated and characterized. The results show that the use of the NIR-absorbing ruthenium complex as a counter electrode material can improve the device performance. By replacing the visible electrochromic ferrocene with the NIR-absorbing ruthenium complex, the optical attenuation at 1550 nm was enhanced from 19.1 to 30.0 dB and color efficiency also increased from 29.2 to 121.2 cm2/C.

  8. Near-infrared analysis for in-line testing of capsules for the pharmaceutical industry

    International Nuclear Information System (INIS)

    A novel electronic system is presented for 100% in-line testing of capsules in high-speed packaging machines for the pharmaceutical industry. The system exploits transmission analysis of near-infrared radiation and works at a speed compatible with production throughput of tens of parts per second. A prototype of the system has been realized and validated with pharmaceutical products. The presented solution, however, can be used in other contexts, such as, in particular, food production and small-part manufacturing. (paper)

  9. The frequency of large variations in the near-infrared fluxes of T Tauri stars

    OpenAIRE

    Scholz, Aleks

    2011-01-01

    Variability is a characteristic feature of young stellar objects (YSOs) and could contribute to the large scatter observed in HR diagrams for star forming regions. For typical YSOs, however, the long-term effects of variability are poorly constrained. Here I use archived near-infrared photometry from 2MASS, UKIDSS, and DENIS to investigate the long-term variability of high-confidence members of the four star forming regions Rho-Oph, ONC, IC348, and NGC1333. The total sample comprises more tha...

  10. Near-infrared spectroscopic study on the effects of chewing on short-term memory.

    Science.gov (United States)

    Wada, Mayumi; Hoshi, Yoko; Iguchi, Yoshinobu; Kida, Ikuhiro

    2011-12-01

    Using near-infrared spectroscopy, we examined whether chewing gum improves performance in a short-term memory task - immediate recall of random eight-digit numbers - by assessing cerebral hemodynamic response in the prefrontal cortex. We found that the oxyhemoglobin concentration during and after chewing gum was higher than that before chewing; further, the concentration increased during the task, and this increase was reduced with chewing, although non-significantly. Chewing did not improve task performance. Therefore, chewing-induced hemodynamic responses were unrelated to the performance in short-term memory tasks. PMID:21911018

  11. Visible/Near-Infrared Hyperspectral Sensing of Solids under Controlled Environmental Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.; Anheier, Norman C.; Mendoza, Albert; Fritz, Brad G.; Johnson, Timothy J.

    2011-06-01

    We describe the use of a wind tunnel for conducting controlled passive hyperspectral imaging experiments. Passive techniques are potentially useful for detecting explosives, solid-phase chemicals and other materials of interest from a distance so as to provide operator safety. The Pacific Northwest National Laboratory operates a wind tunnel facility that can generate and circulate artificial atmospheres to control lighting, humidity, temperature, aerosol burdens, and obscurants. We will present recent results describing optimized sensing of solids over tens of meters distance using both visible and near-infrared cameras, as well as the effects of certain environmental parameters on data retrieval.

  12. Monitoring tissue oxygen availability with near infrared spectroscopy (NIRS) in health and disease

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Langberg, H; Olesen, J;

    2001-01-01

    Near infrared spectroscopy (NIRS) is becoming a widely used research instrument to measure tissue oxygen (O2) status non-invasively. Continuous-wave spectrometers are the most commonly used devices, which provide semi-quantitative changes in oxygenated and deoxygenated hemoglobin in small blood......, brain and connective tissue, and more recently it has been used in the clinical setting to assess circulatory and metabolic abnormalities. Quantitative measures of blood flow are also possible using NIRS and a light-absorbing tracer, which can be applied to evaluate circulatory responses to exercise...

  13. Theranostic reduction-sensitive gemcitabine prodrug micelles for near-infrared imaging and pancreatic cancer therapy

    Science.gov (United States)

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

    2015-12-01

    A biodegradable and reduction-cleavable gemcitabine (GEM) polymeric prodrug with in vivo near-infrared (NIR) imaging ability was reported. This theranostic GEM prodrug PEG-b-[PLA-co-PMAC-graft-(IR820-co-GEM)] was synthesized by ring-opening polymerization and ``click'' reaction. The as-prepared reduction-sensitive prodrug could self-assemble into prodrug micelles in aqueous solution confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In vitro drug release studies showed that these prodrug micelles were able to release GEM in an intracellular-mimicking reductive environment. These prodrug micelles could be effectively internalized by BxPC-3 pancreatic cancer cells, which were observed by confocal laser scanning microscopy (CLSM). Meanwhile, a methyl thiazolyl tetrazolium (MTT) assay demonstrated that this prodrug exhibited high cytotoxicity against BxPC-3 cells. The in vivo whole-animal near-infrared (NIR) imaging results showed that these prodrug micelles could be effectively accumulated in tumor tissue and had a longer blood circulation time than IR820-COOH. The endogenous reduction-sensitive gemcitabine prodrug micelles with the in vivo NIR imaging ability might have great potential in image-guided pancreatic cancer therapy.A biodegradable and reduction-cleavable gemcitabine (GEM) polymeric prodrug with in vivo near-infrared (NIR) imaging ability was reported. This theranostic GEM prodrug PEG-b-[PLA-co-PMAC-graft-(IR820-co-GEM)] was synthesized by ring-opening polymerization and ``click'' reaction. The as-prepared reduction-sensitive prodrug could self-assemble into prodrug micelles in aqueous solution confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In vitro drug release studies showed that these prodrug micelles were able to release GEM in an intracellular-mimicking reductive environment. These prodrug micelles could be effectively internalized by BxPC-3 pancreatic cancer cells, which

  14. Discrimination of industrial products by on-line near infrared spectroscopy with an improved dendrogram

    Institute of Scientific and Technical Information of China (English)

    Jing Jing Liu; Heng Xu; Wen Sheng Cai; Xue Guang Shao

    2011-01-01

    Near infrared (NIR) spectroscopy technique has shown great power and gained wide acceptance for analyzing complicated samples. The present work is to distinguish different brands of tobacco products by using on-line NIR spectroscopy and pattern recognition techniques. Moreover, since each brand contains a large number of samples, an improved dendrogram was proposed to show the classification of different brands. The results suggest that MR spectroscopy combined with principal component analysis (PCA) and hierarchical cluster analysis (HCA) performs well in discrimination of the different brands, and the improved dendrogram could provide more information about the difference of the brands.

  15. Multivariate calibration and moisture control in yerba mate by near infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Larize Mazur

    2014-04-01

    Full Text Available This work describes the development of a multivariate model based on near infrared reflectance spectroscopy (NIR and partial least squares regression for the prediction of the moisture content in yerba mate samples. The multivariate model based on derivatized and multiplicative sign correction (MSC spectral signals (4000-8500 cm-1 was elaborated with 3 latent variables, allowing the fast evaluation of the moisture content with average prediction errors of about 2.5%. The minimal manipulation of the samples permits a high analytical speed that facilitates the implementation of quality control operations.

  16. Optical and Near-Infrared spectroscopy of Nova V1494 Aquilae 1999 #2

    CERN Document Server

    Kamath, U S; Ashok, N M; Mayya, Y D; Sahu, D K

    2005-01-01

    Optical and near-infrared spectroscopic observations of the fast nova V1494 Aquilae 1999 #2 covering various phases -- early decline, transition and nebular -- during the first eighteen months of its post-outburst evolution are presented in this paper. During this period, the nova evolved in the P_fe P_fe^o C_o spectral sequence. The transition from an optically thick wind to a polar blob - equatorial ring geometry is seen in the evolution of the spectral line profiles. There is evidence of density and temperature stratification in the ejecta. Physical conditions in the ejecta have been estimated based on our observations.

  17. Clinical trials in near infrared fluorescence imaging with IRDye 800CW

    Science.gov (United States)

    Draney, Daniel R.

    2015-03-01

    A monofunctional, heptamethine dye, IRDye® 800CW, is being manufactured under GMP conditions for use in human clinical trials. When attached to a suitable targeting agent and paired with an appropriate camera system, the dye allows Near Infrared (NIR) fluorescence imaging of tumor tissue during surgery. The talk will describe the properties of the dye and give an overview of current and planned clinical trials in Europe and the USA. The dye is available in both the NHS ester and carboxylate forms for conjugation to targeting molecules. A GMP toxicology study of the dye was described in a previous publication.

  18. Performance of the Near-infrared coronagraphic imager on Gemini-South

    CERN Document Server

    Chun, Mark; Wahhaj, Zahed; Biller, Beth; Artigau, Etienne; Hayward, Tom; Liu, Mike; Close, Laird; Hartung, Markus; Rigaut, Francois; Ftaclas, Christ

    2008-01-01

    We present the coronagraphic and adaptive optics performance of the Gemini-South Near-Infrared Coronagraphic Imager (NICI). NICI includes a dual-channel imager for simultaneous spectral difference imaging, a dedicated 85-element curvature adaptive optics system, and a built-in Lyot coronagraph. It is specifically designed to survey for and image large extra-solar gaseous planets on the Gemini Observatory 8-meter telescope in Chile. We present the on-sky performance of the individual subsystems along with the end-to-end contrast curve. These are compared to our model predictions for the adaptive optics system, the coronagraph, and the spectral difference imaging.

  19. The End of an Era - The Population III to Population II Transition and the Near Infrared Background

    OpenAIRE

    Fernandez, Elizabeth R.; Zaroubi, Saleem

    2013-01-01

    There are only a few ways to constrain the Era of Reionization and the properties of high redshift (z>6) stars through observations. Here, we discuss one of these observables - the spectrum of the Near Infrared Background - and how it is potentially affected by the transition from Population III to Population II stars. The stronger Lyman-alpha emission expected from massive Population III stars could result in a 'bump' in the spectrum of the Near Infrared Background (referred to in this work ...

  20. The impact of SCIAMACHY near-infrared instrument calibration on CH4 and CO total columns

    OpenAIRE

    Gloudemans, A. M. S.; Schrijver, H.; Kleipool, Q.; Van Den Broek, M. M. P.; A. G. Straume; Lichtenberg, G.; Van Hees, R. M.; Aben, I.; Meirink, J. F.

    2005-01-01

    The near-infrared spectra measured with the SCIAMACHY instrument on board the ENVISAT satellite suffer from several instrument calibration problems. The effects of three important instrument calibration issues on the retrieved methane (CH4) and carbon monoxide (CO) total columns have been investigated: the effects of the growing ice layer on the near-infrared detectors, the effects of the orbital variation of the instrument dark signal, and the effects of the dead/bad detector pixels. Correct...

  1. The impact of SCIAMACHY near-infrared instrument calibration on CH4 and CO total columns

    OpenAIRE

    Aben, I.; Van Hees, R. M.; Lichtenberg, G.; Van Den Broek, M. M. P.; A. G. Straume; Kleipool, Q.; Schrijver, H.; Gloudemans, A. M. S.; Meirink, J. F.

    2005-01-01

    International audience The near-infrared spectra measured with the SCIAMACHY instrument on board the ENVISAT satellite suffer from several instrument calibration problems. The effects of three important instrument calibration issues on the retrieved methane (CH4) and carbon monoxide (CO) total columns have been investigated: the effects of the growing ice layer on the near-infrared detectors, the effects of the orbital variation of the instrument dark signal, and the effects of the dead/ba...

  2. Transcranial Near-Infrared Laser Transmission (NILT) Profiles (800 nm): Systematic Comparison in Four Common Research Species

    OpenAIRE

    Lapchak, Paul A; Boitano, Paul D.; Butte, Pramod V.; Fisher, David J.; Hölscher, Thilo; Ley, Eric J.; Nuño, Miriam; Voie, Arne H; Rajput, Padmesh S.

    2015-01-01

    Background and Purpose Transcranial near-infrared laser therapy (TLT) is a promising and novel method to promote neuroprotection and clinical improvement in both acute and chronic neurodegenerative diseases such as acute ischemic stroke (AIS), traumatic brain injury (TBI), and Alzheimer’s disease (AD) patients based upon efficacy in translational animal models. However, there is limited information in the peer-reviewed literature pertaining to transcranial near-infrared laser transmission (NI...

  3. Aptamer-based luminescence energy transfer from near-infrared-to-near-infrared upconverting nanoparticles to gold nanorods and its application for the detection of thrombin.

    Science.gov (United States)

    Yuan, Fei; Chen, Hongqi; Xu, Juan; Zhang, Yiyan; Wu, Yong; Wang, Lun

    2014-03-01

    A new luminescence energy transfer (LET) system has been designed for the detection of thrombin in the near-infrared (NIR) region by utilizing NIR-to-NIR upconversion lanthanide nanophosphors (UCNPs) as the donor and gold nanorods (Au NRs) as the acceptor. The use of upconverting NaYF4 :Yb(3+) ,Tm(3+) nanoparticles with sharp NIR emission peaks upon NIR excitation by an inexpensive infrared continuous wave laser diode provided large spectral overlap between the donor and the acceptor. Both the Au NRs and carboxyl-terminated NaYF4 :Yb(3+) ,Tm(3+) UCNPs were first modified with different thrombin aptamers. When thrombin was added, a LET system was then formed because of the specific recognition between the thrombin aptamers and thrombin. The LET system was used to monitor thrombin concentrations in aqueous buffer and human blood samples. The limits of detection for thrombin are as low as 0.118 nM in buffer solution and 0.129 nM in human serum. The method was also successfully applied to thrombin detection in blood samples. PMID:24501010

  4. Control of quality and silo storage of sunflower seeds using near infrared technology

    International Nuclear Information System (INIS)

    This work assesses the application of near infrared spectroscopy technology for the quality control of sunflower seeds direct from farmers and from a storage silo. The results show that the analytical method employing near infrared spectroscopy can be used as a rapid and non-destructive tool for the determination of moisture, fat and high/low oleic acid contents in samples of sunflower seeds. The ranges obtained were comparable to those reported for classic chemical methods, and were between 4.6-21.4% for moisture; 38.4-49.6% for fat, and 60.0-93.1% for oleic acid expressed as percentage of total fatty acids. A stepwise discriminant analysis was performed to determine the most useful wavelengths for classifying sunflower seeds in terms of their (high/low) oleic acid composition. The discriminant model allows the acid contents, with a prediction rate of 90.5% for internal validation and of 89.4% for cross-validation. (Author) 23 refs.

  5. Dynamic analysis of temporal moisture profiles in heatset printing studied with near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Dynamic analysis of the water transfer onto coated paper, and its permeation and absorption into the porous structure were studied online in a full-scale heatset web offset printing environment. The moisture content of the paper was investigated at five different positions during the printing process. Changes in the moisture content of the paper were studied as a function of the web temperature, printing speed and silicone application in the folding unit positioned after the hot air drying oven. Additionally, the influence of fountain solution composition on the pick-up by the paper was investigated. The water content of the fountain solution transferred to the paper from the printing units was observed as changes in near-infrared absorbance. A calibration data set enabled the subsequent quantification of the dynamic moisture content of the paper at the studied locations. An increase in the printing speed reduced the water transfer to the paper and an increase in web temperature resulted in a reduction in the moisture content. An increase in the dosage level of the water–silicone mixture was observed as a re-moistening effect of the paper. Differences in the drying strategy resulted in different moisture profiles depending on the type of fountain solution used. As a conclusion, the near-infrared signal provides an effective way to characterize the moisture dynamics online at different press units

  6. A Near-Infrared Spectrometer Based on Novel Grating Light Modulators

    Directory of Open Access Journals (Sweden)

    Weimin Chen

    2009-04-01

    Full Text Available A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.

  7. Precision near-infrared radial velocity instrumentation II: Non-Circular Core Fiber Scrambler

    CERN Document Server

    Plavchan, Peter P; Gao, Peter; Wallace, J Kent; Mennesson, Bertrand; Ciardi, David; Crawford, Sam; Lin, Sean; Beichman, Chas; Brinkworth, Carolyn; Johnson, John Asher; Davison, Cassy; White, Russel; Anglada-Escude, Guillem; von Braun, Kaspar; Vasisht, Gautum; Prato, Lisa; Kane, Stephen; Tanner, Angelle; Walp, Bernie; Mills, Sean

    2013-01-01

    We have built and commissioned a prototype agitated non-circular core fiber scrambler for precision spectroscopic radial velocity measurements in the near-infrared H band. We have collected the first on-sky performance and modal noise tests of these novel fibers in the near-infrared at H and K bands using the CSHELL spectrograph at the NASA InfraRed Telescope Facility (IRTF). We discuss the design behind our novel reverse injection of a red laser for co-alignment of star-light with the fiber tip via a corner cube and visible camera. We summarize the practical details involved in the construction of the fiber scrambler, and the mechanical agitation of the fiber at the telescope. We present radial velocity measurements of a bright standard star taken with and without the fiber scrambler to quantify the relative improvement in the obtainable blaze function stability, the line spread function stability, and the resulting radial velocity precision. We assess the feasibility of applying this illumination stabilizat...

  8. Absorption intensity tunability in the near infrared region using phase-change nanostructure (Presentation Recording)

    Science.gov (United States)

    Ozdemir, Abdurrahman; Saraydemir, Safak; Barut, Bilal; Kocer, Hasan

    2015-08-01

    Nanostructured thin film absorbers embedded with phase-change material (PCM) can provide large level of absorption intensity tunability in the near-infrared region. Germanium Antimonide Tellurite (Ge2Sb1Te4-GST) was employed as the phase-change material in the designed structures. The structure is composed of a periodic grating-type array of 200 nm thick Au buried with 100 nm-thick GST layer from the top of the Au layer. The period of the gratings is 2 μm and in each period, GST width is 0.5 μm. GST was selected as the active PCM because its optical properties undergo a substantial change during a structural transition from the amorphous to the crystalline phase. The optical absorption properties of the designed structures with respect to the geometric and material parameters were systematically investigated using finite-difference time-domain computations. It was shown that absorption intensity in the near-infrared region was tuned from the near-perfect to the near-zero level by switching the PCM from its amorphous to crystalline states. The distributions of the electric field and absorbed power at the resonant wavelengths with respect to different phases of the GST were investigated to further explain the physical origin of the absorption tuning. This study provides a path toward the realization of tunable infrared absorbers for the applications, such as selective infrared emitters, infrared camouflage, sensors, and photovoltaic devices.

  9. Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

    International Nuclear Information System (INIS)

    Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q2 = 0.75, R2 = 0.82 for the total set), especially for samples with chlordecone content -1 or when the sample set was rather homogeneous (Q2 = 0.91, R2 = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg-1, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. - Soil content in chlordecone, an organochlorine insecticide, can be determined time- and cost-effectively using near infrared reflectance spectroscopy (NIRS).

  10. Control of quality and silo storage of sunflower seeds using near infrared technology

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Martin, I.; Vilaescusa-Garcia, V.; Lopez-Gonzalez, F.; Oiz-Jimenez, C.; Lobos-Ortega, I. A.; Gordillo, B.; Hernandez-Hierro, J. M.

    2013-05-01

    This work assesses the application of near infrared spectroscopy technology for the quality control of sunflower seeds direct from farmers and from a storage silo. The results show that the analytical method employing near infrared spectroscopy can be used as a rapid and non-destructive tool for the determination of moisture, fat and high/low oleic acid contents in samples of sunflower seeds. The ranges obtained were comparable to those reported for classic chemical methods, and were between 4.6-21.4% for moisture; 38.4-49.6% for fat, and 60.0-93.1% for oleic acid expressed as percentage of total fatty acids. A stepwise discriminant analysis was performed to determine the most useful wavelengths for classifying sunflower seeds in terms of their (high/low) oleic acid composition. The discriminant model allows the acid contents, with a prediction rate of 90.5% for internal validation and of 89.4% for cross-validation. (Author) 23 refs.

  11. Discriminant analysis of milk adulteration based on near-infrared spectroscopy and pattern recognition

    Science.gov (United States)

    Liu, Rong; Lv, Guorong; He, Bin; Xu, Kexin

    2011-03-01

    Since the beginning of the 21st century, the issue of food safety is becoming a global concern. It is very important to develop a rapid, cost-effective, and widely available method for food adulteration detection. In this paper, near-infrared spectroscopy techniques and pattern recognition were applied to study the qualitative discriminant analysis method. The samples were prepared and adulterated with one of the three adulterants, urea, glucose and melamine with different concentrations. First, the spectral characteristics of milk and adulterant samples were analyzed. Then, pattern recognition methods were used for qualitative discriminant analysis of milk adulteration. Soft independent modeling of class analogy and partial least squares discriminant analysis (PLSDA) were used to construct discriminant models, respectively. Furthermore, the optimization method of the model was studied. The best spectral pretreatment methods and the optimal band were determined. In the optimal conditions, PLSDA models were constructed respectively for each type of adulterated sample sets (urea, melamine and glucose) and all the three types of adulterated sample sets. Results showed that, the discrimination accuracy of model achieved 93.2% in the classification of different adulterated and unadulterated milk samples. Thus, it can be concluded that near-infrared spectroscopy and PLSDA can be used to identify whether the milk has been adulterated or not and the type of adulterant used.

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

    International Nuclear Information System (INIS)

    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 Y2O3 (lipo-Y2O3). Cationic lipo-Y2O3 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-Y2O3 would potentially be useful material for imaging of cancer cells. The embedded Y2O3 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. OISTER Optical and Near-Infrared Observations of Type Iax Supernova 2012Z

    CERN Document Server

    Yamanaka, Masayuki; Kawabata, Koji S; Tanaka, Masaomi; Tominaga, Nozomu; Akitaya, Hiroshi; Nagayama, Takahiro; Kuroda, Daisuke; Takahashi, Jun; Saito, Yoshihiko; Yanagisawa, Kenshi; Fukui, Akihiko; Miyanoshita, Ryo; Watanabe, Makoto; Arai, Akira; Isogai, Mizuki; Hattori, Takashi; Hanayama, Hidekazu; Itoh, Ryosuke; Ui, Takahiro; Takaki, Katsutoshi; Ueno, Issei; Yoshida, Michitoshi; Ali, Gamal B; Essam, Ahmed; Ozaki, Akihito; Nakao, Hikaru; Hamamoto, Ko; Nogami, Daisaku; Morokuma, Tomoki; Oasa, Yumiko; Izumiura, Hideyuki; Sekiguchi, Kazuhiro

    2015-01-01

    We report observations of the Type Iax supernova (SN Iax) 2012Z at optical and near-infrared wavelengths from immediately after the explosion until $\\sim$ $260$ days after the maximum luminosity using the Optical and Infrared Synergetic Telescopes for Education and Research (OISTER) Target-of-Opportunity (ToO) program and the Subaru telescope. We found that the near-infrared (NIR) light curve evolutions and color evolutions are similar to those of SNe Iax 2005hk and 2008ha. The NIR absolute magnitudes ($M_{J}\\sim-18.1$ mag and $M_{H}\\sim-18.3$ mag) and the rate of decline of the light curve ($\\Delta$ $m_{15}$($B$)$=1.6 \\pm 0.1$ mag) are very similar to those of SN 2005hk ($M_{J}\\sim-17.7$ mag, $M_{H}\\sim$$-18.0$ mag, and $\\Delta$ $m_{15}$($B$)$\\sim1.6$ mag), yet differ significantly from SNe 2008ha and 2010ae ($M_{J}\\sim-14 - -15$ mag and $\\Delta$ $m_{15}$($B$)$\\sim2.4-2.7$ mag). The estimated rise time is $12.0 \\pm 3.0$ days, which is significantly shorter than that of SN 2005hk or any other Ia SNe. The rapi...

  14. The Altitude of an Infrared Bright Cloud Feature on Neptune from Near-Infrared Spectroscopy

    CERN Document Server

    Roe, H G; McLean, I S; De Pater, I; Becklin, E E; Figer, D F; Gilbert, A M; Larkin, J E; Levenson, N A; Teplitz, H I; Wilcox, M K; Roe, Henry G.; Graham, James R.; Lean, Ian S. Mc; Pater, Imke de; Figer, Donald F.; Gilbert, Andrea M.; Larkin, James E.; Teplitz, Harry I.; Wilcox, Mavourneen K.

    2001-01-01

    We present 2.03-2.30 micron near-infrared spectroscopy of Neptune taken 1999 June 2 (UT) with the W.M. Keck Observatory's near-infrared spectrometer (NIRSPEC) during the commissioning of the instrument. The spectrum is dominated by a bright cloud feature, possibly a storm or upwelling, in the southern hemisphere at approximately 50 degrees S latitude. The spectrum also includes light from a dimmer northern feature at approximately 30 degrees N latitude. We compare our spectra (R ~ 2000) of these two features with a simple model of Neptune's atmosphere. Given our model assumption that the clouds are flat reflecting layers, we find that the top of the bright southern cloud feature sat at a pressure level of 0.14 (+0.05, -0.03) bar, and thus this cloud did not extend into the stratosphere (P < 0.1 bar). A similar analysis of the dimmer northern feature gives a cloud-top pressure of 0.084 +/- 0.026 bar. This suggests that the features we observed efficiently transport methane to the base of the stratosphere, b...

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

    CERN Document Server

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

    2016-01-01

    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 time scales of a few years and to search for variability of our previously detected excesses. Methods: Using VLTI/PIONIER in H band we have carried out multi-epoch observations of the stars for which a near-infrared excess was previously detected with the same observing 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 o...

  16. Near-infrared Metallicities, Radial Velocities and Spectral Types for 447 Nearby M Dwarfs

    CERN Document Server

    Newton, Elisabeth R; Irwin, Jonathan; Berta-Thompson, Zachory K; Rojas-Ayala, Barbara; Covey, Kevin; Lloyd, James P

    2013-01-01

    We present metallicities, radial velocities and near-infrared spectral types for 447 M dwarfs determined from moderate resolution (R~2000) near-infrared (NIR) spectra obtained with IRTF/SpeX. These M dwarfs are targets of the MEarth Survey, a transiting planet survey searching for super Earths around mid-to-late M dwarfs within 33pc. We present NIR spectral types and new IRTF spectral templates in the Z, J, H and K-bands, created using M dwarfs with near-solar metallicities. We developed two spectroscopic distance calibrations that use NIR spectral type or an index based on the curvature of the K-band continuum. Our distance calibration has a scatter of 14%. We searched 27 NIR spectral lines and 10 spectral indices for metallicity sensitive features, taking into account correlated noise in our estimates of the errors on these parameters. We calibrated our relation using 36 M dwarfs in common proper pairs with an F, G or K-type star of known metallicity. We validated the physical association of these pairs usi...

  17. The nature of the near-infrared interline sky background using fibre Bragg grating OH suppression

    CERN Document Server

    Trinh, Christopher Q; Bland-Hawthorn, Joss; Horton, Anthony J; Lawrence, Jon S; Leon-Saval, Sergio G

    2013-01-01

    (Abridged) We analyse the near-infrared interline sky background, OH and O2 emission in 19 hours of H band observations with the GNOSIS OH suppression unit and the IRIS2 spectrograph at the 3.9-m AAT. The observations cover a range of sky positions with varying lunar conditions throughout the night. We measure the interline background at 1.520 micron where the instrumental thermal background is very low and exploit its variation to determine the presence of non-thermal atmospheric emission, zodiacal scattered light and scattered moonlight. Zodiacal scattered light is too faint to be detected in the summed observations. Our data are consistent with a contribution from moonlight that is ~30 times greater than expected from a model based on extrapolated V band measurements. Demanding near-infrared observations during low lunar phase angles should be made at lunar distances > 80 deg if the background contribution is not to exceed 100 photons s^-1 m^-2 micron^-1 arcsec^-2. Although moonlight may dominate the inter...

  18. Iron Pyrite/Titanium Dioxide Photoanode for Extended Near Infrared Light Harvesting in a Photoelectrochemical Cell

    Science.gov (United States)

    Wang, Di-Yan; Li, Cheng-Hung; Li, Shao-Sian; Kuo, Tsung-Rong; Tsai, Chin-Ming; Chen, Tin-Reui; Wang, Ying-Chiao; Chen, Chun-Wei; Chen, Chia-Chun

    2016-02-01

    The design of active and stable semiconducting composites with enhanced photoresponse from visible light to near infrared (NIR) is a key to improve solar energy harvesting for photolysis of water in photoelectrochemical cell. In this study, we prepared earth abundant semiconducting composites consisting of iron pyrite and Titanium oxide as a photoanode (FeS2/TiO2 photoanode) for photoelectrochemical applications. The detailed structure and atomic compositions of FeS2/TiO2 photoanode was characterized by high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD), inductively coupled plasma with atomic emission spectroscopy (ICPAES) and Raman spectroscopy. Through the proper sulfurization treatment, the FeS2/TiO2 photoanode exhibited high photoresponse from visible light extended to near infrared range (900 nm) as well as stable durability test for 4 hours. We found that the critical factors to enhance the photoresponse are on the elimination of surface defect of FeS2 and on the enhancement of interface charge transfer between FeS2 and TiO2. Our overall results open a route for the design of sulfur-based binary compounds for photoelectrochemical applications.

  19. Detection of the total viable counts in chicken based on visible/near-infrared spectroscopy

    Science.gov (United States)

    Jiang, Fachao; Long, Yuan; Tang, Xiuying; Zhao, Linlin; Peng, Yankun; Wang, Caiping

    2014-05-01

    The viable counts in chicken have significant effects on food safety. Exceeding standard index can have negative influence to the public. Visible-near infrared spectra have had rapid development in food safety recently. The objective of this study was to detect the total viable counts in chicken breast fillets.36 chicken breast fillets used in the study were stored in a refrigerator at 4°C for 9 days. Each day four samples were taken and Vis/NIR spectra were collected from each sample before detecting their total viable counts by standard method. The original data was processed in four main steps: Savitzky-Golay smoothing method, standard normalized variate (SNV), model calibrating and model validating. Prediction model was established using partial least squares regression (PLSR) method. Several statistical indicators such as root mean squared errors and coefficients were calculated for determination of calibration and validation accuracy respectively. As a result, the Rc, SEC, Rv and SEV, of the best model were obtained to be 0.8854, 0.7455, 0.9070 and 0.6045 respectively, which demonstrate that visible-near infrared spectra is a potential technique to detect the total viable counts(TVC) in chicken and the best wavelengths for the establishment of the calibration model are near 449nm.

  20. Application of near-infrared spectroscopy for monitoring and control of cell culture and fermentation

    DEFF Research Database (Denmark)

    Cervera Padrell, Albert Emili; Petersen, Nanna; Eliasson Lantz, Anna;

    2009-01-01

    Near-infrared (NIR) spectroscopy can potentially provide on-line information on substrate, biomass, product, and metabolite concentrations in fermentation processes, which could be useful for improved monitoring or control. However, several factors can negatively influence the quality of chemomet......Near-infrared (NIR) spectroscopy can potentially provide on-line information on substrate, biomass, product, and metabolite concentrations in fermentation processes, which could be useful for improved monitoring or control. However, several factors can negatively influence the quality of...... chemometric models built for interpretation of the spectra, thus impairing the analyte concentration predictions. The aim of this review was to provide an overview of necessary conditions and challenges that one has to face when developing a NIR application for monitoring of cell culture or fermentation...... processes. Important practical aspects are introduced, such as sampling, modeling of biomass concentration, influence of microorganism morphology on the spectra, effects of the hydrodynamic conditions in the fermenter, temperature influence, instrument settings, and signal optimization. Several examples...

  1. 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.

  2. Optimal parameters for near infrared fluorescence imaging of amyloid plaques in Alzheimer's disease mouse models

    International Nuclear Information System (INIS)

    Amyloid-β plaques are an Alzheimer's disease biomarker which present unique challenges for near-infrared fluorescence tomography because of size (<50 μm 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).

  3. Characterizing the stellar photospheres and near-infrared excesses in accreting T Tauri systems

    CERN Document Server

    McClure, M K; Espaillat, C; Hartmann, L; Hernandez, J; Ingleby, L; Luhman, K L; D'Alessio, P; Sargent, B

    2013-01-01

    Using NASA IRTF SpeX data from 0.8 to 4.5 $\\mu$m, we determine self-consistently the stellar properties and excess emission above the photosphere for a sample of classical T Tauri stars (CTTS) in the Taurus molecular cloud with varying degrees of accretion. This process uses a combination of techniques from the recent literature as well as observations of weak-line T Tauri stars (WTTS) to account for the differences in surface gravity and chromospheric activity between the TTS and dwarfs, which are typically used as photospheric templates for CTTS. Our improved veiling and extinction estimates for our targets allow us to extract flux-calibrated spectra of the excess in the near-infrared. We find that we are able to produce an acceptable parametric fit to the near-infrared excesses using a combination of up to three blackbodies. In half of our sample, two blackbodies at temperatures of 8000 K and 1600 K suffice. These temperatures and the corresponding solid angles are consistent with emission from the accreti...

  4. Near-infrared microscopy imaging for quantitative analysis of active component in counterfeit imidacloprid

    Science.gov (United States)

    Huang, Yue; Cao, Jinli; Ye, Shengfeng; Duan, Jia; Wu, Lijun; Li, Qianqian; Min, Shungeng

    2012-01-01

    Near-infrared (NIR) imaging systems simultaneously record spectral and spatial information. Near-infrared imaging was applied to the identification of imidacloprid in both artificially mixed samples and commercial formulation in this study. The distributions of technical imidacloprid and additive in the heterogeneous counterfeit were obtained by the relationship imaging (RI) mode. Furthermore a series of samples which consisted of different contents of uniformly distributed imidacloprid were prepared and three data cubes were generated at each content. Extracted spectra from those images were imported to establish the partial least squares model. The model's results were: R2 99.21%, RMSEC 0.0306, RMSECV 0.0183, RMSECV/mean value 0.0348 and RSEP 0.0784. The prediction relative error of commercial formulation is 0.0680, indicating the predicted value was correlated to the real content. Lastly the chemical value reconstruction image of imidacloprid formulation products was calculated by MATLAB program. NIR microscopy imaging manifests herein its potential in qualitatively identifying the active component in counterfeit pesticide and quantifying the active component in scanned image.

  5. Identification of pesticide varieties by testing microalgae using Visible/Near Infrared Hyperspectral Imaging technology

    Science.gov (United States)

    Shao, Yongni; Jiang, Linjun; Zhou, Hong; Pan, Jian; He, Yong

    2016-04-01

    In our study, the feasibility of using visible/near infrared hyperspectral imaging technology to detect the changes of the internal components of Chlorella pyrenoidosa so as to determine the varieties of pesticides (such as butachlor, atrazine and glyphosate) at three concentrations (0.6 mg/L, 3 mg/L, 15 mg/L) was investigated. Three models (partial least squares discriminant analysis combined with full wavelengths, FW-PLSDA; partial least squares discriminant analysis combined with competitive adaptive reweighted sampling algorithm, CARS-PLSDA; linear discrimination analysis combined with regression coefficients, RC-LDA) were built by the hyperspectral data of Chlorella pyrenoidosa to find which model can produce the most optimal result. The RC-LDA model, which achieved an average correct classification rate of 97.0% was more superior than FW-PLSDA (72.2%) and CARS-PLSDA (84.0%), and it proved that visible/near infrared hyperspectral imaging could be a rapid and reliable technique to identify pesticide varieties. It also proved that microalgae can be a very promising medium to indicate characteristics of pesticides.

  6. Rapid Characterization of Fatty Acids in Oleaginous Microalgae by Near-Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Bin Liu

    2015-03-01

    Full Text Available The key properties of microalgal biodiesel are largely determined by the composition of its fatty acid methyl esters (FAMEs. The gas chromatography (GC based techniques for fatty acid analysis involve energy-intensive and time-consuming procedures and thus are less suitable for high-throughput screening applications. In the present study, a novel quantification method for microalgal fatty acids was established based on the near-infrared spectroscopy (NIRS technique. The lyophilized cells of oleaginous Chlorella containing different contents of lipids were scanned by NIRS and their fatty acid profiles were determined by GC-MS. NIRS models were developed based on the chemometric correlation of the near-infrared spectra with fatty acid profiles in algal biomass. The optimized NIRS models showed excellent performances for predicting the contents of total fatty acids, C16:0, C18:0, C18:1 and C18:3, with the coefficient of determination (R2 being 0.998, 0.997, 0.989, 0.991 and 0.997, respectively. Taken together, the NIRS method established here bypasses the procedures of cell disruption, oil extraction and transesterification, is rapid, reliable, and of great potential for high-throughput applications, and will facilitate the screening of microalgal mutants and optimization of their growth conditions for biodiesel production.

  7. Neuronal Correlates of Cognitive Control during Gaming Revealed by Near-Infrared Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Matthias Witte

    Full Text Available In everyday life we quickly build and maintain associations between stimuli and behavioral responses. This is governed by rules of varying complexity and past studies have identified an underlying fronto-parietal network involved in cognitive control processes. However, there is only limited knowledge about the neuronal activations during more natural settings like game playing. We thus assessed whether near-infrared spectroscopy recordings can reflect different demands on cognitive control during a simple game playing task. Sixteen healthy participants had to catch falling objects by pressing computer keys. These objects either fell randomly (RANDOM task, according to a known stimulus-response mapping applied by players (APPLY task or according to a stimulus-response mapping that had to be learned (LEARN task. We found an increased change of oxygenated and deoxygenated hemoglobin during LEARN covering broad areas over right frontal, central and parietal cortex. Opposed to this, hemoglobin changes were less pronounced for RANDOM and APPLY. Along with the findings that fewer objects were caught during LEARN but stimulus-response mappings were successfully identified, we attribute the higher activations to an increased cognitive load when extracting an unknown mapping. This study therefore demonstrates a neuronal marker of cognitive control during gaming revealed by near-infrared spectroscopy recordings.

  8. Near-Infrared Resonance Energy Transfer Glucose Biosensors in Hybrid Microcapsule Carriers

    Directory of Open Access Journals (Sweden)

    Mike McShane

    2008-09-01

    Full Text Available Fluorescence-based sensing systems offer potential for noninvasive monitoring with implantable devices, but require carrier technologies that provide suitable immobilization, accessibility, and biocompatibility. Recent developments towards this goal include a competitive binding assay for glucose that has been encapsulated in semipermeable microcapsule carriers. This paper describes an extension of this work to increase the applicability to in vivo monitoring, wherein two significant developments are described: (1 a near-infrared resonance energy transfer system for transducing glucose concentration, and (2 novel hybrid organic-inorganic crosslinked microcapsules as carriers. The quenching-based assay is a competitive binding (CB system based on apo-glucose oxidase (AG as the receptor and dextran as the competitive ligand. The encapsulated quencher-labeled dextran and near infrared donor-labeled glucose receptor showed a stable and reversible response with tunable sensitivity of 1–5%/mM over the physiological range, making these transducers attractive for continuous monitoring for biomedical applications.

  9. Quantification of simvastatin in mice plasma by near-infrared and chemometric analysis of spectral data

    Directory of Open Access Journals (Sweden)

    Fahmy UA

    2016-08-01

    Full Text Available Usama A Fahmy Department of Pharmaceutics & Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: Time and cost saving is an essential requirement in pharmacokinetics and bioequivalence studies. The aim of this study is to use a simple, fast, and nondestructive near-infrared transmission spectroscopic method to quantify simvastatin (SMV concentrations in mice plasma and also to improve SMV bioavailability by using alpha-lipoic acid as a carrier. Calibration curve was built at a concentration range of 10–250 ng/mL, and HPLC method was considered as a reference method. A partial least squares regression analysis model was used for method development, which gave less root mean square error cross-validation. Comparison of SMV concentrations obtained from both instruments showed no statistically significant differences between all the data. Near-infrared spectroscopy was utilized as a rapid, simple accurate method to quantify drug–plasma concentrations without need for any extraction protocols, and the significant effect of alpha-lipoic acid as a novel carrier to enhance SMV bioavailability is also addressed. Keywords: alpha lipoic acid, bioavailability, non invasive, FTIR, pharmacokinetics

  10. Five supernova survey galaxies in the southern hemisphere. I. Optical and near-infrared database

    International Nuclear Information System (INIS)

    The determination of the supernova (Sn) rate is based not only on the number of detected events but also on the properties of the parent galaxy population. This is the first paper of a series aimed at obtaining new, refined, Sn rates from a set of five Sn surveys by making use of a joint analysis of near-infrared (Nir) data. We describe the properties of the 3838 galaxies that were monitored for S Ne events, including newly determined morphologies and their Denies and Poses-II/Ust I, 2MASS and DENIS J and KS and 2MASS H magnitudes. We have compared 2MASS, DENIS and POSS-II/UKST IJK magnitudes in order to find possible systematic photometric shifts in the measurements. The DENIS and POSS-II/UKST I band magnitudes show large discrepancies (mean absolute difference of 0.4 mag.), mostly due to different spectral responses of the two instruments, with an important contribution (0.33 mag rms) from the large uncertainties in the photometric calibration of the POSS-II and UKST photo-graphic plates. In the other wavebands, the limiting near infrared magnitude, morphology and inclination of the galaxies are the most influential factors which affect the determination of photometry of the galaxies. Nevertheless, no significant systematic differences have been found between of any pair of NIR magnitude measurements, except for few percent of galaxies showing large discrepancies. This allows to combine DENIS and 2MASS data for the J and KS filters

  11. Utility of near infrared spectroscopy for the screening of the growth restricted fetus.

    Science.gov (United States)

    Acton, Angus L; Goswami, Tarun; McKenna, David S

    2013-09-01

    A myriad of factors have been linked to increased risk for intrauterine growth restriction and the associated complications; the majority of which are based on observational statistics of demographics, socioeconomics and patient history. Unfortunately, there is a paucity of factors available that can appropriately address the underlying anatomy and physiology responsible for intrauterine growth restriction. To this point, it becomes necessary to use data acquisition modalities capable of addressing both the etiology and pathology in an effort to improve clinical management strategies. Near-infrared spectroscopy, although not traditionally used in standard, clinical screening has proven valuable for risk assessment in a number of recent investigational studies. Simulations based on the current literature are presented to assess near infrared spectroscopy utility regarding the ability to distinguish between the normal fetus and the growth restricted fetus. Findings are presented for all simulated data as well as the equipment-specific data derived from the NIRO-100 system (Hamamatsu Photonics, Hamamatsu, Japan). Results suggest an overall sensitivity and specificity on the order of 62% and 58%, respectively, and NIRO-100 sensitivity and specificity on the order of 85% and 92%, respectively. PMID:23998263

  12. THE USE OF NEAR INFRARED SPECTROSCOPY AS A DIAGNOSTIC TOOL FOR HISTORIC SILK ARTEFACTS

    Directory of Open Access Journals (Sweden)

    Paul Garside

    2009-01-01

    Full Text Available As a prestigious and expensive textile, silk is found in manyhistoric artefacts of cultural importance. However, as silkages it becomes increasingly fragile and thus prone to damagethrough handling, display or even conservation treatment;these problems are exacerbated by some of the processingmethods traditionally applied to such materials.Therefore, in order to minimise the danger to these objects,it is vital to have a good understanding of the physical stateof the silk component. It is shown that near infrared spectroscopy,in combination with multivariate analysis, providesa method of assessing the stresses within a silk artefact,thereby highlighting areas at particular risk and allowinginformed decisions to be made as to the potential dangersof intervention. As near infrared spectroscopy mayreadily be used with a fibre optic probe, these analyses canbe performed in situ, rapidly and in a non-invasive manner,thus allowing assessment to be carried out in collectionsand displays without requiring samples to be taken, limitingthe disturbance to artefacts. Therefore, the technique providesa valuable tool to gain a practical understanding ofthe condition of silk artefacts, and a means of informingconservation, display and storage strategies.

  13. Organic peroxyl radical photolysis in the near-infrared: Effects on tropospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Frost, G.J.; Ellison, G.B.; Vaida, V.

    1999-12-09

    This work is an investigation of the effects of near-infrared photolysis of organic peroxyl radicals (RO{sub 2}) on tropospheric chemistry. The authors propose that the excitation of an RO{sub 2} to its lowest excited electronic state with near-infrared (near-IR) light is followed by intramolecular reactions that produce hydroxyl (OH) or hydroperoxyl (HO{sub 2}) radicals. Spectra to this low-lying state have recently been obtained, but absorption cross sections for this electronic transition and yields of the resulting photoproducts have not been directly measured. The authors suggest a limiting range of cross sections from estimates for the same transition in HO{sub 2} and by comparison to other allowed electronic transitions. On the basis of a thermochemical assessment, OH and an aldehyde are proposed as the principal photoproducts of near-IR photolysis of RO{sub 2}. These photolysis reactions are included in a model of the troposphere with a standard photochemical mechanism and conditions appropriate to remote, rural, and urban locations. Inclusion of RO{sub 2} photolysis has a small effect on any of the major tropospheric chemical constituents if lower limit estimates of the absorption cross sections are used. Midrange or upper limit cross section estimates result in significant departures from the currently accepted photochemical scheme. These studies provide a clear need for further measurements of RO{sup 2} absorption cross sections and photoproduct yields, which are the principal uncertainties.

  14. Polarimetry and photometry of active quasars at visual and near-infrared wavelengths

    International Nuclear Information System (INIS)

    The optical and near-infrared continua of highly luminous BL Lacertae (BL Lac) objects and optically violent variable (OVV) quasars are studied through simultaneous broad-band photometry and linear polarimetry. Nineteen BL Lacs and OVVs were monitored during a ∼1 1/2-year period, with the major aim of characterizing the wavelength-dependent polarization exhibited by these objects. Optical (UBVRI) observations were conducted at the UCSD/U. Minn. 1.5-m telescope on Mt. Lemmon, Arizona. Simultaneous (within 1 hr.) near-infrared (JHK) measurements were made using the KPNO 2.1-m telescope. Most of the BL Lac objects exhibit large variations in polarization and brightness on time scale of less than a week. The degree of fractional linear polarization (P) is not observed to be related to brightness or optical spectral index. Most BL Lacs did not show a preferred polarization position angle (theta). Wavelength-dependent P and theta are observed in almost all BL Lacs, but not always simultaneously. The OVV quasar 1156 + 295 shows behavior very similar to the BL Lac objects. 3C 345 Exhibited polarization properties that are quite different from those of the BL Lacs. This object showed a clear correlation between brightness and P

  15. Wavelength-tuneable liquid crystal lasers from the visible to the near-infrared

    Science.gov (United States)

    Hands, P. J. W.; Dobson, C. A.; Morris, S. M.; Qasim, M. M.; Gardiner, D. J.; Wilkinson, T. D.; Coles, H. J.

    2011-10-01

    The study of band-edge lasing from dye-doped chiral nematic liquid crystals has thus far been largely restricted to visible wavelengths. In this paper, a wide range of commercially available laser dyes are examined for their suitability as infrared emitters within a chiral nematic host. Problems such as poor solubility and reduced quantum efficiencies are overcome, and successful band-edge lasing is demonstrated within the range of 735-850 nm, using the dyes LD800, HITC-P and DOTC-P. This paper also reports on progress towards widely tuneable liquid crystal lasers, capable of emission in the region 460- 850 nm. Key to this is the use of common pump source, capable of simultaneously exciting all of the dyes (both infrared and visible) that are present within the system. Towards this aim, we successfully demonstrate near-infrared lasing (800 nm) facilitated by Förster energy transfer between the visible dye DCM, and the infra-red dye LD800, enabling pump wavelengths anywhere between 420 and 532 nm to be used. These results demonstrate that small and low-cost tuneable visible to near-infrared laser sources are achievable, using a single common pump source. Such devices are envisaged to have wide-ranging applications including medical imaging (including optical coherence tomography), point-of-care optical medical diagnostics (such as flow cytometry), telecommunications, and optical signatures for security coatings.

  16. Highlighting the DNA damage response with ultrashort laser pulses in the near infrared and kinetic modeling

    Directory of Open Access Journals (Sweden)

    Elisa eFerrando-May

    2013-07-01

    Full Text Available Our understanding of the mechanisms governing the response to DNA damage in higher eucaryotes crucially depends on our ability to dissect the temporal and spatial organization of the cellular machinery responsible for maintaining genomic integrity. To achieve this goal, we need experimental tools to inflict DNA lesions with high spatial precision at pre-defined locations, and to visualize the ensuing reactions with adequate temporal resolution. Near-infrared femtosecond laser pulses focused through high-aperture objective lenses of advanced scanning microscopes offer the advantage of inducing DNA damage in a 3D-confined volume of subnuclear dimensions. This high spatial resolution results from the highly nonlinear nature of the excitation process. Here we review recent progress based on the increasing availability of widely tunable and user-friendly technology of ultrafast lasers in the near infrared. We present a critical evaluation of this approach for DNA microdamage as compared to the currently prevalent use of UV or VIS laser irradiation, the latter in combination with photosensitizers. Current and future applications in the field of DNA repair and DNA-damage dependent chromatin dynamics are outlined. Finally, we discuss the requirement for proper simulation and quantitative modeling. We focus in particular on approaches to measure the effect of DNA damage on the mobility of nuclear proteins and consider the pros and cons of frequently used analysis models for FRAP and photoactivation and their applicability to nonlinear photoperturbation experiments.

  17. Near-Infrared Imaging of Barred Halo Dominated Low Surface Brightness Galaxies

    CERN Document Server

    Honey, M; Ninan, J P; Purvankara, M

    2016-01-01

    We present a near-infrared (NIR) imaging study of barred low surface brightness (LSB) galaxies using the TIFR near-infrared Spectrometer and Imager (TIRSPEC). LSB galaxies are dark matter dominated, late type spirals that have low luminosity stellar disks but large neutral hydrogen (HI) gas disks. Using SDSS images of a very large sample of LSB galaxies derived from the literature, we found that the barred fraction is only 8.3%. We imaged twenty five barred LSB galaxies in the J, H, K$_S$ wavebands and twenty nine in the K$_S$ band. Most of the bars are much brighter than their stellar disks, which appear to be very diffuse. Our image analysis gives deprojected mean bar sizes of $R_{b}/R_{25}$ = 0.40 and ellipticities $e$ $\\approx$ 0.45, which are similar to bars in high surface brightness galaxies. Thus, although bars are rare in LSB galaxies, they appear to be just as strong as bars found in normal galaxies. There is no correlation of $R_{b}/R_{25}$ or $e$ with the relative HI or stellar masses of the galax...

  18. Improved CEEMDAN and PSO-SVR Modeling for Near-Infrared Noninvasive Glucose Detection

    Science.gov (United States)

    Li, Xiaoli

    2016-01-01

    Diabetes is a serious threat to human health. Thus, research on noninvasive blood glucose detection has become crucial locally and abroad. Near-infrared transmission spectroscopy has important applications in noninvasive glucose detection. Extracting useful information and selecting appropriate modeling methods can improve the robustness and accuracy of models for predicting blood glucose concentrations. Therefore, an improved signal reconstruction and calibration modeling method is proposed in this study. On the basis of improved complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and correlative coefficient, the sensitive intrinsic mode functions are selected to reconstruct spectroscopy signals for developing the calibration model using the support vector regression (SVR) method. The radial basis function kernel is selected for SVR, and three parameters, namely, insensitive loss coefficient ε, penalty parameter C, and width coefficient γ, are identified beforehand for the corresponding model. Particle swarm optimization (PSO) is employed to optimize the simultaneous selection of the three parameters. Results of the comparison experiments using PSO-SVR and partial least squares show that the proposed signal reconstitution method is feasible and can eliminate noise in spectroscopy signals. The prediction accuracy of model using PSO-SVR method is also found to be better than that of other methods for near-infrared noninvasive glucose detection.

  19. The optical properties of mouse skin in the visible and near infrared spectral regions.

    Science.gov (United States)

    Sabino, Caetano P; Deana, Alessandro M; Yoshimura, Tania M; da Silva, Daniela F T; França, Cristiane M; Hamblin, Michael R; Ribeiro, Martha S

    2016-07-01

    Visible and near-infrared radiation is now widely employed in health science and technology. Pre-clinical trials are still essential to allow appropriate translation of optical methods into clinical practice. Our results stress the importance of considering the mouse strain and gender when planning pre-clinical experiments that depend on light-skin interactions. Here, we evaluated the optical properties of depilated albino and pigmented mouse skin using reproducible methods to determine parameters that have wide applicability in biomedical optics. Light penetration depth (δ), absorption (μa), reduced scattering (μ's) and reduced attenuation (μ't) coefficients were calculated using the Kubelka-Munk model of photon transport and spectrophotometric measurements. Within a broad wavelength coverage (400-1400nm), the main optical tissue interactions of visible and near infrared radiation could be inferred. Histological analysis was performed to correlate the findings with tissue composition and structure. Disperse melanin granules present in depilated pigmented mouse skin were shown to be irrelevant for light absorption. Gender mostly affected optical properties in the visible range due to variations in blood and abundance of dense connective tissue. On the other hand, mouse strains could produce more variations in the hydration level of skin, leading to changes in absorption in the infrared spectral region. A spectral region of minimal light attenuation, commonly referred as the "optical window", was observed between 600 and 1350nm. PMID:27101274

  20. Developing Quinoidal Fluorophores with Unusually Strong Red/Near-Infrared Emission.

    Science.gov (United States)

    Ren, Longbin; Liu, Feng; Shen, Xingxing; Zhang, Cheng; Yi, Yuanping; Zhu, Xiaozhang

    2015-09-01

    Despite the dominant position of aromatic fluorophores, we report herein the design and synthesis of quinoidal fluorophores based on rarely emissive quinoidal bithiophene. Quinoidal bitheno[3,4-b]thiophene, QBTT-C6, consisting of cruciform-fused (E)-1,2-bis(5-hexylthiophen-2-yl)ethene and quinoidal bithiophene, shows a fluorescence quantum yield of 8.5%, 25-fold higher than that of the parent quinoidal QBT chromophore, but its maximum emission is at similar wavelengths. QBTT-Ar's featuring intramolecular charge transfer can further shift the maximum emission into the near-infrared region. The intramolecular charge transfer is programmably enhanced by tuning the substituents on the aryl groups from the electron-withdrawing trifluoromethyl to the electron-donating methoxy groups. Unexpectedly, a positive relationship between intramolecular charge transfer and fluorescence quantum yield is observed; as a result, QBTT-FL gives an unprecedentedly high fluorescence quantum yield of up to 53.1% for quinoidal oligothiophenes. With detailed photophysical and theoretical investigations, we demonstrate that the nonradiative intersystem crossing (S1 → T2) is significantly restrained in QBTT-Ar's, which can be attributed to the faster reverse intersystem crossing (T2 → S1) characteristic of a small activation energy. This work reveals the possibility for developing red/near-infrared fluorophores from the less explored quinoidal molecules because of their intrinsically narrow bandgaps. PMID:26293207

  1. Analysis of colon tumors in rats by near-infrared Raman spectroscopy

    Science.gov (United States)

    Duarte, Janaína; Hage, Raduan; Silveira, Landulfo, Jr.; Silveira, Fabricio; Pacheco, Marcos Tadeu T.; Munin, Egberto; Plapler, Hélio

    2007-02-01

    Biomedical applications of near-infrared Raman spectroscopy have increased their importance at the last ten years. This technique can determinate the molecular composition of materials, allowing a sensible and fast biological diagnosis. It has showed to be a promising tool for health diagnosis due to its high sensibility. Colorectal cancer (CRC) is one of the most common malignant tumors in humans beings. In the last decades many experimental models have been developed in animals based in the use of chemical composites to induce the formation and development of these tumors, many of them present similar characteristics to those of natural occurrence aiming to the attainment of information on genesis, evolution, as well as diagnosis and more efficient therapies for treating these neoplasias. Amongst the most used chemical composites is the 1,2- dimetilhydrazine (DMH) because its morphological and histological similarity to those tumors. This study aims to compare in vivo normal colon tissue and tumoral colon tissue, induced by DMH, in rats by near-infrared Raman spectroscopy to permit the use in the near future for an efficient diagnosis in real time besides being useful as an auxiliary method for several therapies, including the photodynamic therapy.

  2. Deep near-infrared observations of W3 Main star forming region

    CERN Document Server

    Ojha, D K; Nakajima, Y; Fukagawa, M; Sugitani, K; Nagashima, C; Nagayama, T; Nagata, T; Sato, S; Pickles, A J; Ogura, K

    2004-01-01

    We present a deep JHKs-band imaging survey of the W3 Main star forming region, using the near-infrared camera, SIRIUS, mounted on the University of Hawaii 2.2m telescope. The near-infrared survey covers an area of ~ 24 sq. arcmin with 10 sigma limiting magnitudes of ~ 19.0, 18.1, and 17.3 in J, H, and Ks-band, respectively. We construct JHK color-color and J/J-H and K/H-K color-magnitude diagrams to identify young stellar objects and estimate their masses. Based on these color-color and color-magnitude diagrams, a rich population of YSOs is identified which is associated with the W3 Main region. A large number of previously unreported red sources (H-K > 2) have also been detected around W3 Main. We argue that these red stars are most probably pre-main sequence stars with intrinsic color excesses. We find that the slope of the Ks-band luminosity function of W3 Main is lower than the typical values reported for the young embedded clusters. The derived slope of the KLF is the same as that found by Megeath et al....

  3. Estimating soil total nitrogen contents from visible/near-infrared reflectance based on successive projections algorithm

    International Nuclear Information System (INIS)

    The Visible/near-infrared reflectance (Vis/NIR) spectroscopy combined with multiple regression methods have been employed to assess various soil properties quantitatively. However, useless or irrelevant information in some bands worsen the performances of the calibrated models. Successive projections algorithm (SPA) is an effective technique for selecting informative variables, and its application potential in estimating soil contents using visible/near-infrared reflectance (Vis/NIR) spectroscopy has not been explored. This paper aimed to explore the effect of SPA combined with support vector machine regression (SVMR) on soil total nitrogen (TN) contents estimation using Vis/NIR spectroscopy. For this purpose, SPA-SVMR was compared with full spectrum based SVMR (FS-SVMR) for soil total nitrogen (TN) estimation, respectively. The results showed that the SPA-SVMR model (R2v = 0.58, RMSEV = 0.364) performed better than the FS-SVMR model (R2v = 0.49, RMSEV = 0.394). We concluded that the SPA could eliminate the uninformative variables and improve the performance of SVMR on estimating TN contents. In further study, using the SPA-SVMR method to estimate other soil properties is necessary to test this finding

  4. High-resolution near-infrared and millimeter-wave spectroscopy of NGC 7027

    International Nuclear Information System (INIS)

    The compact planetary nebula NGC 7027 has been observed at high spectral resolution at near-infrared and millimeter wavelengths. In the near-infrared, the line profiles of H Brackett γ, He ii 10--4, He i 21P--21S are presented and discussed. The widths and intensities of the three lines are generally in agreement with visual and radio recombination line observations. New J = 1→0 12CO and 13CO millimeter-wave observations are also presented. While 12CO was readily detected, 13CO emission at a level reported previously for NGC 7027 could not be confirmed. A peak antena temperature of T(/sub A/ = 0.035 +- 0.007 K was found for 13CO. An isotope ratio of [12C]/[13C]> or =36 +- 6 is derived for the planetary. On the basis of this value, it is suggested that NGC 7027 evolved from a 3 M/sub sun/ star that passed through at least the asymptotic giant branch stage

  5. Near-Infrared Integral Field Spectroscopy of Star-Forming Galaxies

    CERN Document Server

    Dale, D A; Contursi, A; Helou, G; Dinerstein, H L; Hunter, D A; Hollenbach, D J; Egami, E; Matthews, K; Murphy, T W; Lafon, C E; Rubin, R H; Dale, Daniel A.; Roussel, Helene; Contursi, Alessandra; Helou, George; Dinerstein, Harriet L.; Hunter, Deidre A.; Hollenbach, David J.; Egami, Eiichi; Matthews, Keith; Murphy, Thomas W.; Lafon, Christine E.; Rubin, Robert H.

    2004-01-01

    The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios. For the first time, near-infrared spectroscopy was obtained for nuclear or bright HII regions in star-forming galaxies over two spatial dimensions (5.7"x10.0") in the [FeII] (1.257um), [FeII] (1.644um), Paschen beta (1.282um), H2 (2.122um), and Brackett gamma (2.166um) transition lines. These data yield constraints on various characteristics of the star-forming episodes in these regions, including their strength, maturity, spatial variability, and extinction. The HII regions stand out from the nuclei. Unlike observations of nuclear regions, HII region near-infrared observations do not show a spatial coincidence of the line and continuum emission; the continuum and line maps of HII regions usually show distinct and sometimes spatially-separated morphologies. Gauging from Paschen beta and Brackett gamma equ...

  6. Micro- and nanophotonic structures in the visible and near infrared spectral region for optical devices

    International Nuclear Information System (INIS)

    In this paper we present some research results on the micro and nano-photonic structures in the visible and near infrared spectral region for optical devices that have been done within the framework of Nanoscience and Nanotechnology Program of Institute of Materials Science. In the first part, we report the design and fabrication of 1D photonic structure based on porous silicon layers fabricated by electrochemical etching method and some of their potential applications such as optical filters, microcavity and optical sensors for distinguishing the content of bio-gasoline. In addition, we demonstrate some results on preparation of the 2D and 3D nanophotonic structures based on silica opal layers prepared by sol–gel and self-assembled methods. In the second part, we demonstrate the results of lasing emissions of erbium ions in the visible and near infrared zone from microcavity. The observation of emission of single-mode green light at the wavelength of 537 nm from erbium ions in the microcavity is interesting for the study of atom–photon interaction phenomenon. In the last part, we will show some new results of design and fabrication of nanocomposite based on nanoscale TiO2 and/or ZnO and nanoparticles of semiconductors and metals, which are oriented to the fabrication of energy conversion and photo-reactor devices. (review)

  7. Near-infrared Downconversion in LuPO4: Tm3+, Yb3+ Phosphors.

    Science.gov (United States)

    Li, Li; Wang, Yongjie; Shen, Jun; Chang, Wenxuan; Jin, Tianting; Wei, Xiantao; Tian, Ya

    2016-04-01

    Tm3+ and Yb3+ codoped LuPO4 phosphors were synthesized by the reverse-strike co-precipitation method. The obtained LuPO4:Tm3+,Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra, and decay lifetime to understand the observed near-infrared downconversion (DC) phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of LuPO4 and exhibit good crystallinity. The experimental results showed that the strong visible emission around 649 nm from Tm3+(1G4 --> 3F4) and near-infrared (NIR) emission around 1003 nm from Yb3+(2F5/2 --> 2F7/2) of LuPO4:Tm3+,Yb3+ phosphors were observed under 468 nm excitation, respectively. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches 30 mol%. The DC mechanism is also discussed in detail. PMID:27451658

  8. Quantification of simvastatin in mice plasma by near-infrared and chemometric analysis of spectral data

    Science.gov (United States)

    Fahmy, Usama A

    2016-01-01

    Time and cost saving is an essential requirement in pharmacokinetics and bioequivalence studies. The aim of this study is to use a simple, fast, and nondestructive near-infrared transmission spectroscopic method to quantify simvastatin (SMV) concentrations in mice plasma and also to improve SMV bioavailability by using alpha-lipoic acid as a carrier. Calibration curve was built at a concentration range of 10–250 ng/mL, and HPLC method was considered as a reference method. A partial least squares regression analysis model was used for method development, which gave less root mean square error cross-validation. Comparison of SMV concentrations obtained from both instruments showed no statistically significant differences between all the data. Near-infrared spectroscopy was utilized as a rapid, simple accurate method to quantify drug–plasma concentrations without need for any extraction protocols, and the significant effect of alpha-lipoic acid as a novel carrier to enhance SMV bioavailability is also addressed. PMID:27540278

  9. Near-infrared spectroscopy and plasma homovanillic acid levels in bipolar disorder: a case report

    Directory of Open Access Journals (Sweden)

    Miura I

    2014-03-01

    Full Text Available Itaru Miura,1,2 Soichi Kono,1 Sachie Oshima,1 Keiko Kanno-Nozaki,1 Hirobumi Mashiko,1 Shin-Ichi Niwa,1 Hirooki Yabe11Department of Neuropsychiatry, School of Medicine, Fukushima Medical University, Fukushima, Japan; 2Division of Psychiatry Research, The Zucker Hillside Hospital, Glen Oaks, NY, USAAbstract: Misdiagnosis of bipolar disorder is a serious, but not unusual problem for patients. Nevertheless, there are few biomarkers for distinguishing unipolar and bipolar disorder. Near-infrared spectroscopy (NIRS is a noninvasive and useful method for the measurement of hemoglobin concentration changes in the cortical surface area, which enables the assessment of brain function. We measured NIRS and plasma monoamine metabolite levels in a patient with bipolar disorder. A 22-year-old man was admitted due to major depression. At admission, NIRS findings showed oxygenated hemoglobin reincrease in the posttask period, which is characteristic of schizophrenia. After treatment with paroxetine, he became manic with psychotic symptoms. His plasma level of homovanillic acid just before the manic switch was ten times higher than that just after paroxetine initiation. Treatment with lithium and antipsychotics was successful, and plasma homovanillic acid decreased after treatment. In this case, the NIRS findings may predict a possible risk of a manic switch, which is likely induced by paroxetine. NIRS may be able to help distinguish unipolar and bipolar disorder in clinical settings.Keywords: near-infrared spectroscopy, bipolar disorder, homovanillic acid, diagnosis, biomarker

  10. Development of 200-channel mapping system for tissue oxygenation measured by near-infrared spectroscopy

    Science.gov (United States)

    Niwayama, Masatsugu; Kohata, Daisuke; Shao, Jun; Kudo, Nobuki; Hamaoka, Takatumi; Katsumura, Toshihito; Yamamoto, Katsuyuki

    2000-07-01

    Near-infrared spectroscopy (NIRS) is a very useful technique for noninvasive measurement of tissue oxygenation. Among various methods of NIRS, continuous wave near-infrared spectroscopy (CW- NIRS) is especially suitable for real-time measurement and for practical use. CW-NIRS has recently been applied in vivo reflectance imaging of muscle oxygenation and brain activity. However, conventional mapping systems do not have a sufficient mapping area at present. Moreover, they do not enable quantitative measurement of tissue oxygenation because conventional NIRS is based on the inappropriate assumption that tissue is homogeneous. In this study, we developed a 200-channel mapping system that enables measurement of changes in oxygenation and blood volume and that covers a wider area (30 cm x 20 cm) than do conventional systems. The spatial resolution (source- detector separation) of this system is 15 mm. As for the effcts of tissue inhomogeneity on muscle oxygenation measurement, subcutaneous adipose tissue greatly reduces measurement sensitivity. Therefore, we also used a correction method for influence of the subcutaneous fat layer so that we could obtain quantitative changes in concentrations of oxy- and deoxy- hemoglobin. We conducted exercise tests and measured the changed in hemoglobin concentration in the thigh using the new system. The working muscles in the exercises could be imaged, and the heterogeneity of the muscles was shown. These results demonstrated the new 200-channel mapping system enables observation of the distribution of muscle metabolism and localization of muscle function.

  11. HIGH-CONTRAST NEAR-INFRARED IMAGING POLARIMETRY OF THE PROTOPLANETARY DISK AROUND RY TAU

    International Nuclear Information System (INIS)

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at the H band at a high resolution (∼0.''05) for the first time, using Subaru/HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk

  12. Revised Wavelength and Spectral Response Calibrations for AKARI Near-Infrared Grism Spectroscopy: Cryogenic Phase

    CERN Document Server

    Baba, S; Shirahata, M; Isobe, N; Usui, F; Ohyama, Y; Onaka, T; Yano, K; Kochi, C

    2016-01-01

    We perform revised spectral calibrations for the AKARI near-infrared grism to quantitatively correct for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5--5.0 micron with a spectral resolving power of 120 at 3.6 micron, is found to be contaminated by second-order light at wavelengths longer than 4.9 micron which is especially serious for red objects. First, we present the wavelength calibration considering the refractive index of the grism as a function of the wavelength for the first time. We find that the previous solution is positively shifted by up to 0.01 micron compared with the revised wavelengths at 2.5--5.0 micron. In addition, we demonstrate that second-order contamination occurs even with a perfect order-sorting filter owing to the wavelength dependence of the refractive index. Second, the spectral responses of the system from the first- and second-order light are simultaneously obtained from two types of standard objects with dif...

  13. Extending the Canada-France Brown Dwarf Survey to the near infrared

    Directory of Open Access Journals (Sweden)

    Bertin E.

    2011-07-01

    Full Text Available We present the first results of the Canada-France Brown Dwarfs Survey-InfraRed, hereafter CFBDSIR, our near infrared extension to the optical wide field survey CFBDS. Our final objectives are to constrain ultracool atmosphere physics by finding a statistically significant sample of objects cooler than 600K and to explore the ultracool brown dwarf mass function building on a well defined sample of such objects. We identify candidates in CFHT/Wircam J and CFHT/MegaCam z′ images using optimized psf-fitting within Source Extractor, and follow them up with pointed near infrared imaging with SOFI at NTT. We have so far analysed and followed up all candidates on the first 66 square degrees of the 280 square degrees survey. We identified 64 T dwarfs candidates with z′− J > 3.5 and have confirmed 3 of them as ultracool brown dwarfs (later than T7 dwarfs and Y dwarfs candidates, and 14 of them as early and mid-T dwarfs based on their far red and NIR colours. We also present here the NIR spectra of one of these ultracool dwarfs, CFBDSIR1458 which confirms it as one of the coldest brown dwarf known, in the 500–600 K temperature range.

  14. 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.

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

    International Nuclear Information System (INIS)

    Highlights: → Near-Infrared Chemical Imaging was used for pellets analysis. → Distribution of the components throughout the coatings layers and core of the pellets was estimated. → 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.

  16. Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, Didier, E-mail: didier.brunet@ird.f [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France); Woignier, Thierry [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); CNRS - Centre National de la Recherche Scientifique, Universite Montpellier 2, place Eugene Bataillon, 34095 Montpellier Cedex 5 (France); Lesueur-Jannoyer, Magalie; Achard, Raphael [CIRAD (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), PRAM, BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Rangon, Luc [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Barthes, Bernard G. [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France)

    2009-11-15

    Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q{sup 2} = 0.75, R{sup 2} = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg{sup -1} or when the sample set was rather homogeneous (Q{sup 2} = 0.91, R{sup 2} = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg{sup -1}, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. - Soil content in chlordecone, an organochlorine insecticide, can be determined time- and cost-effectively using near infrared reflectance spectroscopy (NIRS).

  17. Virus-mimicking nano-constructs as a contrast agent for near infrared photoacoustic imaging

    Science.gov (United States)

    Gupta, Sharad; Chatni, Muhammad R.; Rao, Ayala L. N.; Vullev, Valentine I.; Wang, Lihong V.; Anvari, Bahman

    2013-02-01

    We report the first proof-of-principle demonstration of photoacoustic imaging using a contrast agent composed of a plant virus protein shell, which encapsulates indocyanine green (ICG), the only FDA-approved near infrared chromophore. These nano-constructs can provide higher photoacoustic signals than blood in tissue phantoms, and display superior photostability compared to non-encapsulated ICG. Our preliminary results suggest that the constructs do not elicit an acute immunogenic response in healthy mice.We report the first proof-of-principle demonstration of photoacoustic imaging using a contrast agent composed of a plant virus protein shell, which encapsulates indocyanine green (ICG), the only FDA-approved near infrared chromophore. These nano-constructs can provide higher photoacoustic signals than blood in tissue phantoms, and display superior photostability compared to non-encapsulated ICG. Our preliminary results suggest that the constructs do not elicit an acute immunogenic response in healthy mice. Electronic supplemental information (ESI) available: Information on experimental procedure for fabrication of the nano-constructs, photoacoustic imaging, and immunogenic studies. See DOI: 10.1039/c3nr34124k

  18. Determination of chemical composition of commercial honey by near-infrared spectroscopy.

    Science.gov (United States)

    Qiu, P Y; Ding, H B; Tang, Y K; Xu, R J

    1999-07-01

    The feasibility of using near-infrared spectroscopy to determine chemical composition of commercial honey was examined. The influences of various sample presentation methods and regression models on the performance of calibration equations were also studied. Transmittance spectra with 1 mm optical path length produced the best calibration for all constituents examined. The regression model of modified partial least squares (mPLS) was selected for the calibration of all honey constituents except moisture, for which the optimal calibration was developed with PLS. Validation of the established calibration equations with independent samples showed that the spectroscopic technique could accurately determine the contents of moisture, fructose, glucose, sucrose, and maltose with squared correlation coefficients (R(2)) of 1.0, 0.97, 0.91, 0.86, and 0.93 between the predicted values and the reference values. The prediction accuracy for free acid, lactone, and hydroxymethylfurfural (HMF) contents in honey was poor and unreliable. The study indicates that near-infrared spectroscopy can be used for rapid determination of major components in commercial honey. PMID:10552561

  19. 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.

  20. Low cost near infrared imaging device for agriculture and general inspection

    International Nuclear Information System (INIS)

    Researchers have found that plants reflect near infrared (NIR) radiation several times more intensely than visible radiation. It has been demonstrated that NIR reflectance of plants begins very quickly when a plant is under stressed. This means that it is often possible to detect stressed areas in a field long before the human eyes begin to see evidence of stress or problem. The most sophisticated devices used to detect plant stress through NIR reflectance are referred to as hyperspectral cameras. A hyperspectral camera will record the radiation intensity of narrow bands throughout the spectrum range of the camera. A less sophisticated class of equipment is referred to as multispectral. Multispectral cameras record only a few (usually 3 or 4) bands of reflectance for each pixel. A near infrared (NIR) images, which can be used to gain early recognition of crop performance or stresses can be acquired using digital camera. Unfortunately, since the cameras are originally intended to record only visible light images, it is not clear how the NIR wavelengths are mapped to the data returned by the camera. This paper reports some early work on the application of digital camera in plants imaging and other application in MINT. (Author)

  1. 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.

  2. [Quality Analysis of Peanut Seed by Visible/Near-Infrared Spectra].

    Science.gov (United States)

    Zheng, Tian-tian; Sun, Teng-fei; Cao, Zeng-hui; Zhang, Jun

    2015-03-01

    In this paper, three representative varieties of peanut seeds were selected for the experiment based on visible/near-infrared reflectance spectroscopy living in the wavelength rang from 600 to 1 100 nm. Firstly, spectral datas ware collected by the near-infrared fiber optic spectrometer, and the spectral features of the original spectral dates were extracted by the wavelet analysis. Then the principal component analysis (PCA) was used for cluster analysis of spectral features. Finally, the four principal components were applied as the inputs, the varieties category as the output and the Mahalanobis distance as the discriminant function of the recognition model, so a linear discriminant analysis model was established. In the 50 samples of each varieties, 30 samples were randomly selected as the training set, and the remaining 20 samples as the predictor set. The recognition model for three peanut varieties have a recognition rate of 95% on average. As the experimental results show that this method is reliable and effectively, and a new method to distinguish and discriminate the quality of peanut seeds was put forword. PMID:26117867

  3. [Applied Research in Grade Estimation of Surimi by Near Infrared Spectroscopy].

    Science.gov (United States)

    Wu, Hao; Chen, Wei-hua; Wang, Xi-chang; Liu, Yuan

    2015-05-01

    The feasibility of utilizing near infrared spectroscopy for estimating frozen and thawed white croaker surimi with different grades was presented in the research. First-derivative and standard normal variable transformation were used as pretreatment method, then principal component analysis was carried out on the processed datas. Establish grade estimation model on white croaker surimi with different grades by principal component analysis-mahalanobis distance pattern recognition method. Seven kinds of physicochemical indexes (moisture, protein, crude fat, salt-soluble protein, gel strength, water-holding ability and whiteness) of white croaker surimi with different grades were determinated. We came to the following conclusions. Firstly, white croaker surimi with three grade could be distinguished effectively by principal component analysis. Secondly, the model of grade estimation established by principal component analysis-mahalanobis distance pattern recognition method had better performance on frozen white croaker surimi than thawed ones, the former's comprehensive accuracy was 96. 3 % with the latter's is 83. 3%. Thirdly, the physicochemical indexes of white croaker surimi with different grades had some distinctions. The research indicated that near infrared spectroscopy could estimate the grade of white croaker surimi rapidly and nondestructively. PMID:26415435

  4. Through Skull Fluorescence Imaging of the Brain in a New Near-Infrared Window

    CERN Document Server

    Hong, Guosong; Chang, Junlei; Antaris, Alexander L; Chen, Changxin; Zhang, Bo; Zhao, Su; Atochin, Dmitriy N; Huang, Paul L; Andreasson, Katrin I; Kuo, Calvin J; Dai, Hongjie

    2014-01-01

    To date, brain imaging has largely relied on X-ray computed tomography and magnetic resonance angiography with limited spatial resolution and long scanning times. Fluorescence-based brain imaging in the visible and traditional near-infrared regions (400-900 nm) is an alternative but currently requires craniotomy, cranial windows and skull thinning techniques, and the penetration depth is limited to 1-2 mm due to light scattering. Here, we report through-scalp and through-skull fluorescence imaging of mouse cerebral vasculature without craniotomy utilizing the intrinsic photoluminescence of single-walled carbon nanotubes in the 1.3-1.4 micrometre near-infrared window. Reduced photon scattering in this spectral region allows fluorescence imaging reaching a depth of >2 mm in mouse brain with sub-10 micrometre resolution. An imaging rate of ~5.3 frames/s allows for dynamic recording of blood perfusion in the cerebral vessels with sufficient temporal resolution, providing real-time assessment of blood flow anomaly...

  5. Vibrational Spectroscopy of Intramolecular Hydrogen Bonds in the Infrared and Near-Infrared Regions

    DEFF Research Database (Denmark)

    Schrøder, Sidsel Dahl

    This PhD thesis describes the gas phase studies of four intramolecular hydrogen bonds: O-H···O (in methyl lactate), O-H···π (in methallyl carbinol and allyl carbinol), O-H···N (in methylated and triuoromethylated 2-aminoethanol) and N-H···N (in the diamines 1,2-diaminoethane, 1,3-diaminopropane 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...... spectra. The experimental characterization of hydrogen bonds have been complemented by theoretical analyzes. These analyzes are based on the electron density topology, natural bond orbital theory and visualization of the distribution of electrostatic potential energy in the molecules. In these studies...

  6. Noninvasive imaging of multiple myeloma using near infrared fluorescent molecular probe

    Science.gov (United States)

    Hathi, Deep; Zhou, Haiying; Bollerman-Nowlis, Alex; Shokeen, Monica; Akers, Walter J.

    2016-03-01

    Multiple myeloma is a plasma cell malignancy characterized by monoclonal gammopathy and osteolytic bone lesions. Multiple myeloma is most commonly diagnosed in late disease stages, presenting with pathologic fracture. Early diagnosis and monitoring of disease status may improve quality of life and long-term survival for multiple myeloma patients from what is now a devastating and fatal disease. We have developed a near-infrared targeted fluorescent molecular probe with high affinity to the α4β1 integrin receptor (VLA-4)overexpressed by a majority of multiple myeloma cells as a non-radioactive analog to PET/CT tracer currently being developed for human diagnostics. A near-infrared dye that emits about 700 nm was conjugated to a high affinity peptidomimmetic. Binding affinity and specificity for multiple myeloma cells was investigated in vitro by tissue staining and flow cytometry. After demonstration of sensitivity and specificity, preclinical optical imaging studies were performed to evaluate tumor specificity in murine subcutaneous and metastatic multiple myeloma models. The VLA-4-targeted molecular probe showed high affinity for subcutaneous MM tumor xenografts. Importantly, tumor cells specific accumulation in the bone marrow of metastatic multiple myeloma correlated with GFP signal from transfected cells. Ex vivo flow cytometry of tumor tissue and bone marrow further corroborated in vivo imaging data, demonstrating the specificity of the novel agent and potential for quantitative imaging of multiple myeloma burden in these models.

  7. Quantum annealing

    OpenAIRE

    Ruiz, Alfonso de la Fuente

    2014-01-01

    Brief description on the state of the art of some local optimization methods: Quantum annealing Quantum annealing (also known as alloy, crystallization or tempering) is analogous to simulated annealing but in substitution of thermal activation by quantum tunneling. The class of algorithmic methods for quantum annealing (dubbed: 'QA'), sometimes referred by the italian school as Quantum Stochastic Optimization ('QSO'), is a promising metaheuristic tool for solving local search problems in mult...

  8. Chemical durability of zircon

    Science.gov (United States)

    Trocellier, Patrick; Delmas, Robert

    2001-07-01

    Zircon (ZrSiO 4) exhibits a strong structural affinity for uranium and thorium together with a very high chemical durability. This makes it a potential crystalline host matrix to immobilize actinides issued from separation of nuclear wastes. Irradiation induces amorphization of the crystalline structure (the metamictization process) and thus may decrease the chemical durability of the material. Leaching tests have been conducted on natural zircons from Brazil and Madagascar at 96°C for a period of 1 month, using deionized water. Leachates have been analysed by inductively coupled plasma mass spectrometry (ICP-MS) and UV-visible spectrophotometry. Zircon solid surfaces have been investigated by coupling scanning electron microscopy and X-ray microanalysis (SEM-EDX) with nuclear microprobe analysis ( μPIXE, μRBS and μERDA). From the mass balance between leachates and hydrated surfaces, the probable mechanisms of zircon aqueous alteration are presented and discussed.

  9. Chemical durability of zircon

    International Nuclear Information System (INIS)

    Zircon (ZrSiO4) exhibits a strong structural affinity for uranium and thorium together with a very high chemical durability. This makes it a potential crystalline host matrix to immobilize actinides issued from separation of nuclear wastes. Irradiation induces amorphization of the crystalline structure (the metamictization process) and thus may decrease the chemical durability of the material. Leaching tests have been conducted on natural zircons from Brazil and Madagascar at 96 deg. C for a period of 1 month, using deionized water. Leachates have been analysed by inductively coupled plasma mass spectrometry (ICP-MS) and UV-visible spectrophotometry. Zircon solid surfaces have been investigated by coupling scanning electron microscopy and X-ray microanalysis (SEM-EDX) with nuclear microprobe analysis (μPIXE, μRBS and μERDA). From the mass balance between leachates and hydrated surfaces, the probable mechanisms of zircon aqueous alteration are presented and discussed

  10. Near-Infrared Hubble Diagrams and The Effectiveness of Using Type Ia Supernovae as Standard Candles In The Near-Infrared.

    Science.gov (United States)

    Gooding, Samuel D.; Hsiao, E. Y.; Marion, G. H.; Krisciunas, K.; Suntzeff, N. B.

    2009-12-01

    We use a combination of near-infrared and optical data to study the diversity in intrinsic brightness of Type Ia supernovae and to learn how better to correct for the systematic errors involved in using them as standard candles. Our sample includes light curves of 29 nearby Type Ia SNe from the Carnegie Supernova Project (CSP) at Las Campanas observatory in Chile, which observes in both optical (uBVgri) and near-IR (YJHK) filters, and other well observed nearby Type Ia SNe having light curves with both optical and near-IR data published in the literature. We also use more than forty near-IR spectra from the Marion/IRTF data set plus eleven near-IR spectra of SN 1999ee from Hamuy et al. (2002). The combined set of near-IR spectra consists of many different SNe and covers the epoch range from -13 days to +76 days with respect to V-band maximum. We are working on deriving a set of near-IR, K-corrected, and extinction-corrected YJHK light curve templates and new methods for fitting future YJHK light curve data. From observations of 20 Type Ia supernovae obtained by the CSP collaboration, along with previously published results, I will present near-IR Hubble diagrams and derived absolute magnitudes at maximum brightness for the objects that have well observed near-IR light curves. Type Ia supernovae appear to be standard candles in the near-IR to ±0.15 mag or better and there is much less extinction by dust in the near-IR compared to the optical. A better understanding of the Standard Candle nature of SNe will enable us to improve their usefulness as precise distance indicators and enter deeper into the era of precision cosmology.

  11. Near-infrared spectroscopy for process and substrate supervision of a full-scale biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Jacobi, Hans Fabian

    2012-07-01

    Aim of this study was to investigate the possible use of near-infrared spectroscopy in the supervision of the biogas production process or parts thereof. It was examined, whether the surveillance of (a) the process and (b) substrate was feasible. The following tasks were accomplished to this end: 1. Development, construction and assembly of suitable NIRS-metrology, development of proper control-software as well as of strategies for data acquisition and data handling, 2. calculation and validation of regression models on the basis of acquired spectra and reference data for (a) suitable parameters of the biogas process, (b) composition and biogas potential of the substrate, 3. calculation of continuous time series of all parameters in order to prove the possibility of continuous surveillance, 4. integrated processing of continuously calculated biogas potentials together with plant data for the prediction of the biogas production behavior of the biogas plant. A near-infrared spectrometer was installed and equipped with NIR-measuring heads of own design and construction on a full-scale agricultural biogas plant. For 500 days spectra were continuously logged at (a) a pipe flowed through by fermenter slurry and (b) the feeding station, where silage passed. Based on regularly withdrawn reference samples and the corresponding spectra regression models were calibrated for the several constituents. Continuously logged spectra were used to calculate time series with the aid of the regression models for each constituent. Models and time series were established for the following parameters: (a) process parameters: volatile fatty acids, acetic acid, propionic acid, dry matter, volatile solids; (b) substrate parameters: dry matter, volatile solids, crude fiber, crude fat, crude protein, nitrogen-free extracts, experimentally assessed biogas potential, theoretically assessed biogas potential. Despite the partially low quality of the models it was possible to follow the course of

  12. Far-red to near infrared emission and scattering spectroscopy for biomedical applications

    Science.gov (United States)

    Zhang, Gang

    2001-06-01

    The thesis investigates the far-red and near infrared (NIR) spectral region from biomedical tissue samples for monitoring the state of tissues. The NIR emission wing intensity is weak in comparison to the emission in the visible spectral region. The wing emission from biomedical samples has revealed meaningful information about the state of the tissues. A model is presented to explain the shape of the spectral wing based on a continuum of energy levels. The wing can be used to classify different kinds of tissues; especially it can be used to differentiate cancer part from normal human breast tissues. The research work of the far-red emission from thermal damaged tissue samples shows that the emission intensity in this spectral region is proportional to the extent of the thermal damage of the tissue. Near infrared spectral absorption method is used to investigate blood hemodynamics (perfusion and oxygenation) in brain during sleep-wake transition. The result of the research demonstrates that the continuous wave (CW) type near infrared spectroscopy (NIRS) device can be used to investigate brain blood perfusion and oxygenation with a similar precision with frequency domain (FD) type device. The human subject sleep and wake transition, has been monitored by CW type NIRS instrument with traditional electroencephalograph (EEG) method. Parallel change in oxy-Hb and deoxy-Hb is a discrete event that occurs in the transition from both sleep to wakefulness and wakefulness to sleep. These hemodynamic switches are generally about few seconds delayed from the human decided transition point between sleep and wake on the polygraph EEG recording paper. The combination of NIRS and EEG methods monitor the brain activity, gives more information about the brain activity. The sleep apnea investigation was associated with recurrent apneas, insufficient nasal continuous positive airway pressure (CPAP) and the different response of the peripheral and central compartments to breathing

  13. [Study on an Algorithm for Near Infrared Singular Sample Identification Based on Strong Influence Degree].

    Science.gov (United States)

    Wu, Zhao-na; Ding, Xiang-qian; Gong, Hui-li; Dong, Mel; Wang, Mei-xun

    2015-07-01

    Correcting sample selection and elimination of singular sample is very important for the quantitative and qualitative modeling of near infrared spectroscopy. However, methods for identification of singular sample available are generally based on data center estimates which require an experience decision threshold, this largely limit its recognition accuracy and practicability. Aiming at the low accuracy of the existing methods of singular sample recognition problem, this paper improves the existing metric-Leverage value and presents a new algorithm for near infrared singular sample identification based on strong influence degree. This metric reduces the dependence on the data center to a certain extent, so that the normal samples become more aggregation, and the distance between the singular samples and the normal samples is opened; at the same time, in order to avoid artificial setting threshold unreasonably according to experience, this paper introduces the concept of the jump degree in the field of statistics, and proposes an automatic threshold setting method to distinguish singular samples. In order to verify the validity of our algorithm, abnormal samples of 200 representative samples were eliminated in the calibration set with using Mahalanobis distance, Leverage-Spectral residual method and the algorithm presented in this paper respectively; then through partial least squares (PLS), the rest of the calibration samples were made quantitative modelings (took Nicotine as index), and the results of quantitative modelings were made a comparative analysis; besides, 60 representative testing samples were made a prediction through the modelings; at last, all the algorithms above were made a comparison with took Root Mean Square Error of Cross Validation (RMSECV), Correlation Coefficient (r) and Root Mean Square Error of Prediction (RMSEP) as evaluation Index. The experimental results demonstrate that the algorithm for near infrared singular sample identification

  14. Detection of adulteration in acetonitrile using near infrared spectroscopy coupled with pattern recognition techniques.

    Science.gov (United States)

    Hu, Le-Qian; Yin, Chun-Ling; Zeng, Zhi-Peng

    2015-12-01

    In this paper, near infrared spectroscopy (NIR) in cooperation with the pattern recognition techniques were used to determine the type of neat acetonitrile and the adulteration in acetonitrile. NIR spectra were collected between 400 nm and 2498 nm. The experimental data were first subjected to analysis of principal component analysis (PCA) to reveal significant differences and potential patterns between samples. Then support vector machine (SVM) were applied to develop classification models and the best parameter combination was selected by grid search. Under the best parameter combination, the classification accuracy rates of three types of neat acetonitrile reached 87.5%, and 100% for the adulteration with different concentration levels. The results showed that NIR spectroscopy combined with SVM could be utilized for determining the potential adulterants including water, ethanol, isopropyl alcohol, acrylonitrile, methanol, and by-products associated with the production of acetonitrile. PMID:26123603

  15. Probing depth and dynamic response of speckles in near infrared region for spectroscopic blood flow imaging

    Science.gov (United States)

    Yokoi, Naomichi; Aizu, Yoshihisa

    2016-04-01

    Imaging method based on bio-speckles is a useful means for blood flow visualization of living bodies and, it has been utilized for analyzing the condition or the health state of living bodies. Actually, the sensitivity of blood flow is influenced by tissue optical properties, which depend on the wavelength of illuminating laser light. In the present study, we experimentally investigate characteristics of the blood flow images obtained with two wavelengths of 780 nm and 830 nm in the near-infrared region. Experiments are conducted for sample models using a pork layer, horse blood layer and mirror, and for a human wrist and finger, to investigate optical penetration depth and dynamic response of speckles to the blood flow velocity for two wavelengths.

  16. Near-Infrared (NIR) Spectroscopy of Synthetic Hydroxyapatites and Human Dental Tissues.

    Science.gov (United States)

    Kolmas, Joanna; Marek, Dariusz; Kolodziejski, Waclaw

    2015-08-01

    Near-infrared spectroscopy (NIR) was used to analyze synthetic hydroxyapatite calcined at various temperatures, synthetic carbonated hydroxyapatite, and human hard dental tissues (enamel and dentin). The NIR bands of those materials in the combination, first-overtone, and second-overtone spectral regions were assigned and evaluated for structural characterization. They were attributed to adsorbed and structural water, structural hydroxyl (OH) groups and surface P-OH groups. The NIR spectral features were quantitatively discussed in view of proton solid-state magic-angle spinning nuclear magnetic resonance ((1)H MAS NMR) results. We conclude that the NIR spectra of apatites are useful in the structural characterization of synthetic and biogenic apatites. PMID:26163232

  17. Food Safety Evaluation Based on Near Infrared Spectroscopy and Imaging: A Review.

    Science.gov (United States)

    Fu, Xiaping; Ying, Yibin

    2016-08-17

    In recent years, due to the increasing consciousness of food safety and human health, much progress has been made in developing rapid and nondestructive techniques for the evaluation of food hazards, food authentication, and traceability. Near infrared (NIR) spectroscopy and imaging techniques have gained wide acceptance in many fields because of their advantages over other analytical techniques. Following a brief introduction of NIR spectroscopy and imaging basics, this review mainly focuses on recent NIR spectroscopy and imaging applications for food safety evaluation, including (1) chemical hazards detection; (2) microbiological hazards detection; (3) physical hazards detection; (4) new technology-induced food safety concerns; and (5) food traceability. The review shows NIR spectroscopy and imaging to be effective tools that will play indispensable roles for food safety evaluation. In addition, on-line/real-time applications of these techniques promise to be a huge growth field in the near future. PMID:24972267

  18. Photoacoustic imaging of the near-infrared fluorescent protein iRFP in vivo

    Science.gov (United States)

    Krumholz, Arie; Filonov, Grigory S.; Xia, Jun; Yao, Junjie; Verkhusha, Vladislav V.; Wang, Lihong V.

    2012-02-01

    Genetically encoded probes powerfully and non-invasively target specific tissues, cells, and subcellular locations. iRFP, a novel near-infrared fluorescent protein with low quantum yield whose absorption and fluorescence maxima are located at wavelengths longer than the Q-band of hemoglobin absorption, is ideal for PAT. Here, we report on an in vitro comparison of iRFP with other far-red fluorescent proteins, and its use in imaging a mouse tumor xenograft model. In an in vivo experiment, we stably transfected iRFP into MTLn3 adenocarcinoma cells and injected them into the mammary fat pad of female SCID/NCr mice, then imaged the resulting tumors two and three weeks post injection. The contrast increase from the protein expression was high enough to clearly separate the tumor region from the rest of the animal.

  19. Methodical experiences on application of near-infrared reflectance spectroscopy (NIRS) for breeding of rapeseed kernels

    International Nuclear Information System (INIS)

    In rapeseed breeding special efforts are undertaken to manipulate genetically the composition of constituents in the seed. Success in this field depends on efficient analytical methods for a determination of the relevant constituents. Therefore, near infrared reflectance spectroscopy (NIRS) has a high potential in rapeseed breeding applications. Being based on physical principles, NIRS allows a fast, easy, and non-destructive determination of several constituents by one single measurement. In this study, the applicability of NIRS for quality breeding of rapeseed was investigated. Using a type of NIRS-instrument designed for scientific applications, at first general prerequisites for the optimal development of NIRS methods have been investigated. Then specific NIRS methods for the determination of several constituents were established for NIRS measurement of intact rapeseed kernels. Lastly NIRS routine analysis was tested in rapeseed breeding applications

  20. Virtually pure near-infrared electroluminescence from exciplexes at polyfluorene/hexaazatrinaphthylene interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tregnago, G.; Fléchon, C.; Cacialli, F., E-mail: amateo@polymat.eu, E-mail: f.cacialli@ucl.ac.uk [Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, London WC1E 6BT (United Kingdom); Choudhary, S. [School of Soft Matter Research, Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs-Universität Freiburg, Albertstraße 19, 79104 Freiburg (Germany); Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg (Germany); Gozalvez, C. [POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian (Spain); Mateo-Alonso, A., E-mail: amateo@polymat.eu, E-mail: f.cacialli@ucl.ac.uk [POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, E-20018 Donostia-San Sebastian (Spain); Ikerbasque, Basque Foundation for Science, Bilbao (Spain)

    2014-10-06

    Electronic processes at the heterojunction between chemically different organic semiconductors are of special significance for devices such as light-emitting diodes (LEDs) and photovoltaic diodes. Here, we report the formation of an exciplex state at the heterojunction of an electron-transporting material, a functionalized hexaazatrinaphthylene, and a hole-transporting material, poly(9,9-dioctylfluorene-alt-N-(4-butylphenyl)diphenylamine) (TFB). The energetics of the exciplex state leads to a spectral shift of ∼1 eV between the exciton and the exciplex peak energies (at 2.58 eV and 1.58 eV, respectively). LEDs incorporating such bulk heterojunctions display complete quenching of the exciton luminescence, and a nearly pure near-infrared electroluminescence arising from the exciplex (at ∼1.52 eV) with >98% of the emission at wavelengths above 700 nm at any operational voltage.