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Sample records for infrared microscope based

  1. Infrared microscope inspection apparatus

    DOEpatents

    Forman, Steven E.; Caunt, James W.

    1985-02-26

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

  2. Infrared microscope inspection apparatus

    DOEpatents

    Forman, S.E.; Caunt, J.W.

    1985-02-26

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

  3. [Microscopic infrared spectral imaging of oily core].

    PubMed

    Huang, Qiao-Song; Yu, Zhao-Xian; Li, Jing; Chen, Chen

    2009-02-01

    In the present paper, the authors examined some oily core by microscopic infrared spectral imaging methods. Those methods can be classified in three modes, referred to as "transmission mode", "reflection mode" and "attenuated total reflection (ATR) mode". The observed oily core samples belong to siltstone. The samples were made of quartz (-20%), feldspar(-50%) and other rock (igneous rock 25%, metamorphic rocks 1%, sedimentary rock 4%); a little recrystallized calcite (-1%) was in the pore, and the argillaceous matter was distributed along the edge of a pore. The experimental work has been accomplished using SHIMADZU Model IRPrestige-21 Fourier transform infrared spectrophotometer plus AIM8800 infrared microscope. For IRPrestige-21, the spectral range is 7 800-350 cm(-1) spectral resolution is 1 cm(-1), and AIM8800 microscope with motorized stages has a resolution of 1 micrometer. The experiment was preformed at room temperature. In "transmission mode" infrared spectral imaging method, the spectral range was limited in wavenumbers greater than 2 000 cm(-1) because the base glass piece has strong light absorption. In contrast with "transmission mode", in "attenuated total reflection (ATR) mode", the depth of penetration into sample is very small (1-2 micrometer), then the absorbance value has nothing to do with base glass piece light absorption. In microscopic infrared transmission spectra, the experimental result shows that there are some strong absorption peaks at 2 866, 2 928, 3 618 and 2 515 cm(-1) respectively. The former two peaks correspond to methyl(methylene) symmetrical and unsymmetrical stretch vibration mode, respectively. The latter two peaks correspond to hydroxyl-stretch vibration mode and S-H, P-H chemical bond stretch vibration mode, respectively. In microscopic longwave infrared ATR spectra, there are other stronger absorption peaks at 1 400, 1 038 and 783 cm(i1)respectively, corresponding to methyl(methylene) widing vibration mode and optical mode

  4. [Microscopic infrared spectral imaging of oily core].

    PubMed

    Huang, Qiao-Song; Yu, Zhao-Xian; Li, Jing; Chen, Chen

    2009-02-01

    In the present paper, the authors examined some oily core by microscopic infrared spectral imaging methods. Those methods can be classified in three modes, referred to as "transmission mode", "reflection mode" and "attenuated total reflection (ATR) mode". The observed oily core samples belong to siltstone. The samples were made of quartz (-20%), feldspar(-50%) and other rock (igneous rock 25%, metamorphic rocks 1%, sedimentary rock 4%); a little recrystallized calcite (-1%) was in the pore, and the argillaceous matter was distributed along the edge of a pore. The experimental work has been accomplished using SHIMADZU Model IRPrestige-21 Fourier transform infrared spectrophotometer plus AIM8800 infrared microscope. For IRPrestige-21, the spectral range is 7 800-350 cm(-1) spectral resolution is 1 cm(-1), and AIM8800 microscope with motorized stages has a resolution of 1 micrometer. The experiment was preformed at room temperature. In "transmission mode" infrared spectral imaging method, the spectral range was limited in wavenumbers greater than 2 000 cm(-1) because the base glass piece has strong light absorption. In contrast with "transmission mode", in "attenuated total reflection (ATR) mode", the depth of penetration into sample is very small (1-2 micrometer), then the absorbance value has nothing to do with base glass piece light absorption. In microscopic infrared transmission spectra, the experimental result shows that there are some strong absorption peaks at 2 866, 2 928, 3 618 and 2 515 cm(-1) respectively. The former two peaks correspond to methyl(methylene) symmetrical and unsymmetrical stretch vibration mode, respectively. The latter two peaks correspond to hydroxyl-stretch vibration mode and S-H, P-H chemical bond stretch vibration mode, respectively. In microscopic longwave infrared ATR spectra, there are other stronger absorption peaks at 1 400, 1 038 and 783 cm(i1)respectively, corresponding to methyl(methylene) widing vibration mode and optical mode

  5. Large scale infrared imaging of tissue micro arrays (TMAs) using a tunable Quantum Cascade Laser (QCL) based microscope.

    PubMed

    Bassan, Paul; Weida, Miles J; Rowlette, Jeremy; Gardner, Peter

    2014-08-21

    Chemical imaging in the field of vibrational spectroscopy is developing into a promising tool to complement digital histopathology. Applications include screening of biopsy tissue via automated recognition of tissue/cell type and disease state based on the chemical information from the spectrum. For integration into clinical practice, data acquisition needs to be speeded up to implement a rack based system where specimens are rapidly imaged to compete with current visible scanners where 100's of slides can be scanned overnight. Current Fourier transform infrared (FTIR) imaging with focal plane array (FPA) detectors are currently the state-of-the-art instrumentation for infrared absorption chemical imaging, however recent development in broadly tunable lasers in the mid-IR range is considered the most promising potential candidate for next generation microscopes. In this paper we test a prototype quantum cascade laser (QCL) based spectral imaging microscope with a focus on discrete frequency chemical imaging. We demonstrate how a protein chemical image of the amide I band (1655 cm(-1)) of a 2 × 2.4 cm(2) breast tissue microarray (TMA) containing over 200 cores can be measured in 9 min. This result indicates that applications requiring chemical images from a few key wavelengths would be ideally served by laser-based microscopes.

  6. Large scale infrared imaging of tissue micro arrays (TMAs) using a tunable Quantum Cascade Laser (QCL) based microscope.

    PubMed

    Bassan, Paul; Weida, Miles J; Rowlette, Jeremy; Gardner, Peter

    2014-08-21

    Chemical imaging in the field of vibrational spectroscopy is developing into a promising tool to complement digital histopathology. Applications include screening of biopsy tissue via automated recognition of tissue/cell type and disease state based on the chemical information from the spectrum. For integration into clinical practice, data acquisition needs to be speeded up to implement a rack based system where specimens are rapidly imaged to compete with current visible scanners where 100's of slides can be scanned overnight. Current Fourier transform infrared (FTIR) imaging with focal plane array (FPA) detectors are currently the state-of-the-art instrumentation for infrared absorption chemical imaging, however recent development in broadly tunable lasers in the mid-IR range is considered the most promising potential candidate for next generation microscopes. In this paper we test a prototype quantum cascade laser (QCL) based spectral imaging microscope with a focus on discrete frequency chemical imaging. We demonstrate how a protein chemical image of the amide I band (1655 cm(-1)) of a 2 × 2.4 cm(2) breast tissue microarray (TMA) containing over 200 cores can be measured in 9 min. This result indicates that applications requiring chemical images from a few key wavelengths would be ideally served by laser-based microscopes. PMID:24965124

  7. Development of a scanning near-field infrared microscope based on a free electron laser

    SciTech Connect

    Hong, M.K.; Erramilli, S.; Jeung, A.

    1995-12-31

    Infrared spectroscopy is one of the most sensitive technique available for identifying and characterizing organic materials. Most molecules exhibit a large number of well-resolved strongly absorbing spectral lines in the mid-IR region of the spectrum. In addition to our own efforts described last year, Creuzet et al have also been working on combining infrared spectroscopy with sub-micron spatial resolution imaging. Scanning Near Field Infrared Microscopy (SNIM) when combined with high brightness tunable FEL radiation, provides a powerful new research tool. We have developed two new probes for use in SNIM. The first are chalcogenide fibers capable of transmitting images in the 2-12 {mu} range. At the Stanford picosecond Free Electron Laser, we have successfully obtained images of metal surfaces and of collagen fibers on diamond at a wavelength of 5.01 {mu}, with a nominal spatial resolution of 0.5 {mu} demonstrating that near field imaging can be obtained on biological samples. At a wavelength of 6.3{mu}, we found that the chalcogenide fibers are limited in their ability to withstand high powers, most likely because of the presence of absorption bands in the polyimide coating used to sheath the brittle fibers. In collaboration with Prof J. Harrington (Rutgers University), we have also developed hollow glass capillaries with metal coated on the inside. These probes are able to withstand significantly higher powers, and can function to longer wavelengths, out into the Far IR region.

  8. [Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

    PubMed

    Jiang, Zhi-quan; Hu, Ke-liang

    2016-03-01

    In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science. PMID:27400510

  9. [Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

    PubMed

    Jiang, Zhi-quan; Hu, Ke-liang

    2016-03-01

    In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science.

  10. [Identification of pearl powder using microscopic infrared reflectance spectroscopy].

    PubMed

    Zhang, Xuan; Hu, Chao; Yan, Yan; Yang, Hai-Feng; Li, Jun-Fang; Bai, Hua; Xi, Guang-Cheng; Liao, Jie

    2014-09-01

    Pearl is a precious ornament and traditional Chinese medicine, which application history in China is more than 2000 years. It is well known that the chemical ingredients of shell and pearl are very similar, which all of them including calcium carbonate and various amino acids. Generally, shell powders also can be used as medicine; however, its medicinal value is much lower than that of pearl powders. Due to the feature similarity between pearl powders and shell powders, the distinguishment of them by detecting chemical composition and morphology is very difficult. It should be noted that shell powders have been often posing as pearl powders in markets, which seriously infringes the interests of consumers. Identification of pearl powder was investigated by microscopic infrared reflectance spectroscopy, and pearl powder as well as shell powder was calcined at different temperatures for different time before infrared reflectance spectroscopy analysis. The experimental results indicated that when calcined at 400 °C for 30 minutes under atmospheric pressure, aragonite in pearl powder partly transformed into calcite, while aragonite in shell powder completely transformed into calcite. At the same time, the difference in phase transition between the pearl powders 'and shell powders can be easily detected by using the microscopic infrared reflectance spectroscopy. Therefore, based on the difference in their phase transition process, infrared reflectance spectroscopy can be used to identify phase transformation differences between pearl powder and shell powder. It's more meaningfully that the proposed infrared reflectance spec- troscopy method was also investigated for the applicability to other common counterfeits, such as oyster shell powders and abalone shell powders, and the results show that the method can be a simple, efficiently and accurately method for identification of pearl powder. PMID:25532338

  11. Detection of microscopic particles present as contaminants in latent fingerprints by means of synchrotron radiation-based Fourier transform infra-red micro-imaging.

    PubMed

    Banas, A; Banas, K; Breese, M B H; Loke, J; Heng Teo, B; Lim, S K

    2012-08-01

    Synchrotron radiation-based Fourier transform infra-red (SR-FTIR) micro-imaging has been developed as a rapid, direct and non-destructive technique. This method, taking advantage of the high brightness and small effective source size of synchrotron light, is capable of exploring the molecular chemistry within the microstructures of microscopic particles without their destruction at high spatial resolutions. This is in contrast to traditional "wet" chemical methods, which, during processing for analysis, often caused destruction of the original samples. In the present study, we demonstrate the potential of SR-FTIR micro-imaging as an effective way to accurately identify microscopic particles deposited within latent fingerprints. These particles are present from residual amounts of materials left on a person's fingers after handling such materials. Fingerprints contaminated with various types of powders, creams, medications and high explosive materials (3-nitrooxy-2,2-bis(nitrooxymethyl)propyl nitrate (PETN), 1,3,5-trinitro-1,3,5-triazinane (RDX), 2-methyl-1,3,5-trinitrobenzene (TNT)) deposited on various - daily used - substrates have been analysed herein without any further sample preparation. A non-destructive method for the transfer of contaminated fingerprints from hard-to-reach areas of the substrates to the place of analysis is also presented. This method could have a significant impact on forensic science and could dramatically enhance the amount of information that can be obtained from the study of fingerprints.

  12. Microscopic spectral imaging using mid-infrared semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Guo, Bujin-.; Wang, Yi; Peng, Chuan; Luo, Guipeng; Le, Han Q.

    2003-07-01

    Infrared micro-spectroscopy is a useful tool for basic research and biomedical applications. Conventional microspectroscopic imaging apparatuses use thermal sources for sample illumination, which have low brightness, low optical spectral intensity, and high noise. This work evaluates the system engineering advantages of using mid-infrared semiconductor lasers that offer orders-of magnitude higher brightness, spectral intensity, and lower noise. A laser-based microscopic spectral imaging system with focal plane array detectors demonstrated a high signal-to-noise ratio (>20 dB) at video frame rate for a large illuminated area. Microscopic spectral imaging with fixed-wavelength and tunable lasers of 4.6, 6, and 9.3-μm wavelength was applied to a number of representative samples that consist of biological tissues (plant and animal) and solid material (a stack of laminated polymers). Transmission spectral images with ~30-dB dynamic range were obtained with clear evidence of spectral features for different samples. The potential of more advanced systems with a wide coverage of spectral bands is discussed.

  13. Nanoscale Spectroscopy with a Scanning Near-Field Infrared Microscope

    NASA Astrophysics Data System (ADS)

    Michaels, Chris; Richter, Lee; Cavanagh, Richard; Stranick, Stephan

    2001-03-01

    The development of a scanning near-field microscope that allows the measurement of infrared spectra with nanoscale spatial resolution will be described. This instrument couples the spatial resolution of a scanning probe microscope with the chemical specificity of vibrational spectroscopy. This combination allows the in situ mapping of chemical functional groups with subwavelength spatial resolution. Infrared transmission images of a micropatterned thin gold film will be presented that demonstrate spatial resolution of λ/10 at 3.4 micrometers in the absence of artifacts due to topography-induced contrast. Near-field infrared absorption spectra of thin polymer films that demonstrate sensitivity sufficient for sub-diffraction absorption imaging in the aliphatic and aromatic C-H stretching regions will also be presented. Images of thin film polymer blends and nanocomposites acquired in the C-H stretching region will be used to benchmark the nanoscale chemical imaging capabilities of this microscope.

  14. An improved far-infrared microscope with quantum Hall detectors

    NASA Astrophysics Data System (ADS)

    Ikushima, Kenji; Sakuma, Hisato; Komiyama, Susumu

    2003-05-01

    A highly-sensitive scanning far-infrared (FIR) microscope is developed. The microscope consists of a silicon solid immersion lens that probes FIR and a condenser lens that focuses the FIR onto a small and highly-sensitive quantum Hall detector. The solid immersion lens is in contact with a sample, which is moved with a mechanical stage. The microscope is successfully applied to image extremely weak cyclotron emission from quantum Hall devices with a spatial resolution about 50 μm and a signal-to-noise ratio improved by a factor 18 compared to a previous system.

  15. Forensic applications of microscopical infrared internal reflection spectroscopy

    NASA Astrophysics Data System (ADS)

    Tungol, Mary W.; Bartick, Edward G.; Reffner, John A.

    1994-01-01

    Applications of microscopical infrared internal reflection spectroscopy in forensic science are discussed. Internal reflection spectra of single fibers, hairs, paint chips, vehicle rubber bumpers, photocopy toners, carbon copies, writing ink on paper, lipstick on tissue, black electrical tape, and other types of forensic evidence have been obtained. The technique is convenient, non-destructive, and may permit smeared materials to be analyzed in situ.

  16. Polarization microscope using a near infrared full-Stokes imaging polarimeter.

    PubMed

    Hsu, Wei-Liang; Davis, Jeffrey; Balakrishnan, Kaushik; Ibn-Elhaj, Mohammed; Kroto, Shona; Brock, Neal; Pau, Stanley

    2015-02-23

    This paper presents a polarization microscope using an infrared (IR) full-Stokes imaging polarimeter. The IR polarimeter utilizes an optimized interference-based micropolarizer design, and provides full-Stokes images with resolution of 1608 × 1208 at 35 frames/second. The device fabrication, instrument calibration, performance evaluation, and measurement results are presented. The measurement error of the imaging polarimeter is less than 3.5%, and the standard deviations are less than 2%. PMID:25836472

  17. Foldscope: Origami-Based Paper Microscope

    PubMed Central

    Cybulski, James S.; Clements, James; Prakash, Manu

    2014-01-01

    Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education. PMID:24940755

  18. Ground based infrared astronomy

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.

    1988-01-01

    Infrared spectroscopic instrumentation has been developed for ground-based measurements of astrophysical objects in the intermediate infrared. A conventional Michelson interferometer is limited for astronomical applications in the intermediate infrared by quantum noise fluctuations in the radiation form the source and/or background incident on the detector, and the multiplex advantage is no longer available. One feasible approach to recovering the multiplex advantage is post-dispersion. The infrared signal after passing through telescope and interferometer, is dispersed by a low resolution grating spectrometer onto an array of detectors. The feasibility of the post-dispersion system has been demonstrated with observations of astrophysical objects in the 5 and 10 micrometer atmospheric windows from ground-based telescopes. During FY87/88 the post-disperser was used at the Kitt Peak 4-meter telescope and McMath telescope with facility Fourier transform spectrometers. Jupiter, Saturn, Mars, and Venus were observed. On Jupiter, the resolution at 12 micrometer was 0.01/cm, considerably higher than had been acheived previously. The spectrum contains Jovian ethane and acetylene emission. Construction was begun on the large cryogenic grating spectrometer.

  19. Versatile multispectral microscope based on light emitting diodes

    NASA Astrophysics Data System (ADS)

    Brydegaard, Mikkel; Merdasa, Aboma; Jayaweera, Hiran; Ålebring, Jens; Svanberg, Sune

    2011-12-01

    We describe the development of a novel multispectral microscope, based on light-emitting diodes, capable of acquiring megapixel images in thirteen spectral bands from the ultraviolet to the near infrared. The system captures images and spectra in transmittance, reflectance, and scattering modes. We present as examples of applications ground truth measurements for remote sensing and parasitology diagnostics. The system is a general purpose scientific instrument that could be used to develop dedicated simplified instruments with optimal bands and mode selection.

  20. Chemical imaging of cotton fibers using an infrared microscope and a focal-plane array detector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this presentation, the chemical imaging of cotton fibers with an infrared microscope and a Focal-Plane Array (FPA) detector will be discussed. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In addition, FPA detectors allow for simultaneous spe...

  1. Atomic force microscope infrared spectroscopy of griseofulvin nanocrystals

    PubMed Central

    Harrison, A. J.; Bilgili, E. A.; Beaudoin, S. P.

    2013-01-01

    The goal of this work was to evaluate the ability of photothermal induced resonance (PTIR) to measure the local infrared absorption spectra of crystalline organic drug nanoparticles embedded within solid matrices. Herein, the first reports of the chemical characterization of sub-100 nm organic crystals are described; infrared spectra of 90 nm griseofulvin particles were obtained, confirming the chemical resolution of PTIR beyond the diffraction limit. Additionally, particle size distributions via dynamic light scattering and PTIR image analysis were found to be similar, suggesting that the PTIR measurements are not significantly affected by inhomogeneous infrared absorptivity of this system. Thus as medical applications increasingly emphasize localized drug delivery via micro/nano-engineered structures, PTIR can be used to unambiguously chemically characterize drug formulations at these length scales. PMID:24171582

  2. Laser scan microscope and infrared laser scan microcope: two important tools for device testing

    NASA Astrophysics Data System (ADS)

    Ziegler, Eberhard

    1991-03-01

    The optical beam induced current (OBIC) produced in devices by a laser scan microscope (LSM) is used to localize hot spots, leakage currents, electrostatic discharge defects and weak points. The LSM also allows photoluminescence measurements with high spatial and energy resolution. Using the infrared laser scan microscope (IR LSM), defects in the metallization and latch-up sensitive region could be detected from the back of the device.

  3. Detection and measurement of electroreflectance on quantum cascade laser device using Fourier transform infrared microscope

    SciTech Connect

    Enobio, Eli Christopher I.; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo

    2013-12-02

    We demonstrate the use of a Fourier Transform Infrared microscope system to detect and measure electroreflectance (ER) from mid-infrared quantum cascade laser (QCL) device. To characterize intersubband transition (ISBT) energies in a functioning QCL device, a microscope is used to focus the probe on the QCL cleaved mirror. The measured ER spectra exhibit resonance features associated to ISBTs under applied electric field in agreement with the numerical calculations and comparable to observed photocurrent, and emission peaks. The method demonstrates the potential as a characterization tool for QCL devices.

  4. Infrared Detection of Evidence for Microscopic Organisms on Europa

    NASA Astrophysics Data System (ADS)

    Dalton, J. B.; Mogul, R.

    2002-12-01

    The infrared detection of evidence for microorganisms on surfaces of icy satellites requires four conditions: (1) the emplacement of microorganisms at the surface, (2) the survival of biotic material in the hostile conditions of space, (3) that the biotic material exhibit diagnostic infrared absorption features and (4) spectra with sufficient resolution and signal-to-noise ratios. This paper will focus on each topic with respect to cryogenic data recently collected on model microorganisms. Several studies suggest that materials from a Europan interior ocean have been emplaced in disrupted regions[1-10]. If the Europan ocean at one time contained Life and its associated biomolecules, then it is possible that surface materials may still harbor some remnant of these structures. Such remnant material must be capable of surviving the low pressure, low temperature and high radiation environment. The terrestrial extremophile Deinococcus radiodurans has been found viable after exposure both to vacuum at temperatures as low as 80 K [11] and to 60 Gy/h of radiation[12]. The chemical degradation of D. radiodurans has also been shown to be dependent on plasma composition (O2 {>>} CO2)[13]. Hence, it is reasonable to assume that some degree of sterilization and degradation would be occurring at the surface of Europa. However, given the sputtering rate at Europa of approximately a few cm every few million years [14], it is possible that fresh material may be continually exposed from depths to which little radiation penetrates. Remote sensing of the surface, therefore, would not be dependent on the survival of the microorganism but on the endurance of the particular biomolecules that give rise to the spectral signature. This endurance is not unreasonable since previous studies have detected hydrated salts, which contain labile bonds to water, on Europa [3,15]. Cryogenic reflectance spectra of hydrated sulfate salts have broad (150-300 nm), asymmetric absorption features due to

  5. Optical microscopic imaging based on VRML language

    NASA Astrophysics Data System (ADS)

    Zhang, Xuedian; Zhang, Zhenyi; Sun, Jun

    2009-11-01

    As so-called VRML (Virtual Reality Modeling Language), is a kind of language used to establish a model of the real world or a colorful world made by people. As in international standard, VRML is the main kind of program language based on the "www" net building, which is defined by ISO, the kind of MIME is x-world or x-VRML. The most important is that it has no relationship with the operating system. Otherwise, because of the birth of VRML 2.0, its ability of describing the dynamic condition gets better, and the interaction of the internet evolved too. The use of VRML will bring a revolutionary change of confocal microscope. For example, we could send different kinds of swatch in virtual 3D style to the net. On the other hand, scientists in different countries could use the same microscope in the same time to watch the same samples by the internet. The mode of sending original data in the model of text has many advantages, such as: the faster transporting, the fewer data, the more convenient updating and fewer errors. In the following words we shall discuss the basic elements of using VRML in the field of Optical Microscopic imaging.

  6. Infrared astronomical data base and catalog of infrared observations

    NASA Technical Reports Server (NTRS)

    Schmitz, M.; Gezari, D. Y.; Mead, J. M.

    1981-01-01

    The NASA/Goddard Space Flight Center has developed a computer data base of infrared astronomical observations. The data base represents a machine-readable library of infrared observational data published in the relevant literature since 1960 for celestial sources outside the solar system. It likewise includes the contents of infrared surveys and catalogs. A catalog of infrared observations has been developed in both printed and magnetic-tape formats. The data base will be accessed through a bibliographic guide and an atlas of infrared source names and positions. Future plans also include two-dimensional graphical displays of infrared data and a user-interactive data terminal.

  7. Infrared microscopic imaging of cutaneous wound healing: lipid conformation in the migrating epithelial tongue

    NASA Astrophysics Data System (ADS)

    Yu, Guo; Stojadinovic, Olivera; Tomic-Canic, Marjana; Flach, Carol R.; Mendelsohn, Richard

    2012-09-01

    Infrared microscopic imaging has been utilized to analyze for the first time the spatial distribution of lipid structure in an ex vivo human organ culture skin wound healing model. Infrared images were collected at zero, two, four, and six days following wounding. Analysis of lipid infrared spectral properties revealed the presence of a lipid class with disordered chains within and in the vicinity of the migrating epithelial tongue. The presence of lipid ester C=O bands colocalized with the disordered chains provided evidence for the presence of carbonyl-containing lipid species. Gene array data complemented the biophysical studies and provided a biological rationale for the generation of the disordered chain species. This is the first clear observation, to our knowledge, of disordered lipid involvement in cutaneous wound healing. Several possibilities are discussed for the biological relevance of these observations.

  8. Real-time quantum cascade laser-based infrared microspectroscopy in-vivo

    NASA Astrophysics Data System (ADS)

    Kröger-Lui, N.; Haase, K.; Pucci, A.; Schönhals, A.; Petrich, W.

    2016-03-01

    Infrared microscopy can be performed to observe dynamic processes on a microscopic scale. Fourier-transform infrared spectroscopy-based microscopes are bound to limitations regarding time resolution, which hampers their potential for imaging fast moving systems. In this manuscript we present a quantum cascade laser-based infrared microscope which overcomes these limitations and readily achieves standard video frame rates. The capabilities of our setup are demonstrated by observing dynamical processes at their specific time scales: fermentation, slow moving Amoeba Proteus and fast moving Caenorhabditis elegans. Mid-infrared sampling rates between 30 min and 20 ms are demonstrated.

  9. Inquiry based learning with a virtual microscope

    NASA Astrophysics Data System (ADS)

    Kelley, S. P.; Sharples, M.; Tindle, A.; Villasclaras-Fernández, E.

    2012-12-01

    As part of newly funded initiative, the Wolfson OpenScience Laboratory, we are linking a tool for inquiry based learning, nQuire (http://www.nquire.org.uk) with the virtual microscope for Earth science (http://www.virtualmicroscope.co.uk) to allow students to undertake projects and gain from inquiry based study thin sections of rocks without the need for a laboratory with expensive petrological microscopes. The Virtual Microscope (VM) was developed for undergraduate teaching of petrology and geoscience, allowing students to explore rock hand specimens and thin sections in a browser window. The system is based on HTML5 application and allows students to scan and zoom the rocks in a browser window, view in ppl and xpl conditions, and rotate specific areas to view birefringence and pleochroism. Importantly the VM allows students to gain access to rare specimens such as Moon rocks that might be too precious to suffer loss or damage. Experimentation with such specimens can inspire the learners' interest in science and allows them to investigate relevant science questions. Yet it is challenging for learners to engage in scientific processes, as they may lack scientific investigation skills or have problems in planning their activities; for teachers, managing inquiry activities is a demanding task (Quintana et al., 2004). To facilitate the realization of inquiry activities, the VM is being integrated with the nQuire tool. nQuire is a web tool that guides and supports students through the inquiry process (Mulholland et al., 2011). Learners are encouraged to construct their own personally relevant hypothesis, pose scientific questions, and plan the method to answer them. Then, the system enables users to collect and analyze data, and share their conclusions. Teachers can monitor their students' progress through inquiries, and give them access to new parts of inquiries as they advance. By means of the integration of nQuire and the VM, inquiries that involve collecting data

  10. A highly sensitive scanning far-infrared microscope with quantum Hall detectors

    NASA Astrophysics Data System (ADS)

    Ikushima, Kenji; Sakuma, Hisato; Komiyama, Susumu

    2003-09-01

    We develop a highly sensitive scanning far-infrared (FIR) microscope, which consists of a silicon solid immersion lens that probes FIR and a condenser lens that focuses the FIR onto a small quantum Hall detector (400 μm×400 μm). The solid immersion lens is in contact with the backside of a Hall bar sample, which is moved with a mechanical XY stage. The quantum Hall detector, which function as a narrow band FIR detector (bandwidth of about 2%), is a Hall bar with a large length-to-width ratio in integer quantum Hall effect regimes. The microscope is successfully applied to image extremely weak cyclotron emissions from quantum Hall devices with a spatial resolution of about 50 μm and a signal-to-noise ratio improved by a factor 18 compared to a previous system.

  11. Examination of cotton fibers and common contaminants using an infrared microscope and a focal-plane array detector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chemical imaging of cotton fibers and common contaminants in fibers is presented. Chemical imaging was performed with an infrared microscope equipped with a Focal-Plane Array (FPA) detector. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In a...

  12. [Remote Slit Lamp Microscope Consultation System Based on Web].

    PubMed

    Chen, Junfa; Zhuo, Yong; Liu, Zuguo; Chen, Yanping

    2015-11-01

    To realize the remote operation of the slit lamp microscope for department of ophthalmology consultation, and visual display the real-time status of remote slit lamp microscope, a remote slit lamp microscope consultation system based on B/S structure is designed and implemented. Through framing the slit lamp microscope on the website system, the realtime acquisition and transmission of remote control and image data is realized. The three dimensional model of the slit lamp microscope is established and rendered on the web by using WebGL technology. The practical application results can well show the real-time interactive of the remote consultation system. PMID:27066677

  13. Infrared astronomical data base and catalog of infrared observations

    NASA Astrophysics Data System (ADS)

    Schmitz, M.; Gezari, D. Y.; Mead, J. M.

    A computer data base of infrared astronomical observations has been established at NASA/Goddard Space Flight Center. It contains a summary of all infrared (1-100 microns) observations of celestial sources outside the solar system, published in the major scientific journals since 1960, as well as the contents of infrared surveys and catalogs. A Catalog of Infrared Observations (CIO) has been developed from the data base in printed and magnetic tape versions. A bibliographic Guide to the Infrared Astronomical Literature, and an Altas of Infrared Source Names and Positions will be published in conjunction with the catalog. Future plans include development of an interactive data system at Goddard which will give a user direct access to the computerized data.

  14. Infrared astronomical data base and catalog of infrared observations

    NASA Technical Reports Server (NTRS)

    Schmitz, M.; Gezari, D. Y.; Mead, J. M.

    1982-01-01

    A computer data base of infrared astronomical observations has been established at NASA/Goddard Space Flight Center. It contains a summary of all infrared (1-100 microns) observations of celestial sources outside the solar system, published in the major scientific journals since 1960, as well as the contents of infrared surveys and catalogs. A Catalog of Infrared Observations (CIO) has been developed from the data base in printed and magnetic tape versions. A bibliographic Guide to the Infrared Astronomical Literature, and an Altas of Infrared Source Names and Positions will be published in conjunction with the catalog. Future plans include development of an interactive data system at Goddard which will give a user direct access to the computerized data.

  15. All-near-infrared multiphoton microscopy interrogates intact tissues at deeper imaging depths than conventional single- and two-photon near-infrared excitation microscopes.

    PubMed

    Sarder, Pinaki; Yazdanfar, Siavash; Akers, Walter J; Tang, Rui; Sudlow, Gail P; Egbulefu, Christopher; Achilefu, Samuel

    2013-10-01

    The era of molecular medicine has ushered in the development of microscopic methods that can report molecular processes in thick tissues with high spatial resolution. A commonality in deep-tissue microscopy is the use of near-infrared (NIR) lasers with single- or multiphoton excitations. However, the relationship between different NIR excitation microscopic techniques and the imaging depths in tissue has not been established. We compared such depth limits for three NIR excitation techniques: NIR single-photon confocal microscopy (NIR SPCM), NIR multiphoton excitation with visible detection (NIR/VIS MPM), and all-NIR multiphoton excitation with NIR detection (NIR/NIR MPM). Homologous cyanine dyes provided the fluorescence. Intact kidneys were harvested after administration of kidney-clearing cyanine dyes in mice. NIR SPCM and NIR/VIS MPM achieved similar maximum imaging depth of ∼100 μm. The NIR/NIR MPM enabled greater than fivefold imaging depth (>500 μm) using the harvested kidneys. Although the NIR/NIR MPM used 1550-nm excitation where water absorption is relatively high, cell viability and histology studies demonstrate that the laser did not induce photothermal damage at the low laser powers used for the kidney imaging. This study provides guidance on the imaging depth capabilities of NIR excitation-based microscopic techniques and reveals the potential to multiplex information using these platforms.

  16. Portable, X-Y translating, infrared microscope for remote inspection of photovoltaic solar arrays

    SciTech Connect

    Forman, S.E.; Caunt, J.W.

    1980-01-01

    The prevalent physical defect found in terrestrial photovoltaic modules during manufacture and field exposure has been the cracked solar cell. Cells can become cracked during handling, because of thermal mismatch in their encapsulation packages, or due to environmental phenomena such as hail. A device is described which can be used remotely to locate cracked silicon solar cells in photovoltaic modules. This solar-cell inspection device can be used either in the laboratory for quality assurance and failure analysis evaluation or at array fields to monitor cracked-cell occurrence. It consists of: (a) an infrared microscope that operates at 1.0 micron, uses darkfield illumination, has a relatively large field of view (3.0 in.), has low system magnification (5X to 15X), and has a video display output; (b) a portable X-Y translator that is capable of moving the microscope over an 8 ft. x 8 ft. area; and (c) a console that allows remote instrument control and visual inspection of modules or arrays (up to 500 ft). This system presently is undergoing laboratory and field testing as part of the DOE-sponsored MIT Lincoln Laboratory Solar Photovoltiac Residential Project.

  17. Wave-Based Inversion & Imaging for the Optical Quadrature Microscope

    SciTech Connect

    Lehman, S K

    2005-10-27

    The Center for Subsurface Sensing & Imaging System's (CenSSIS) Optical Quadrature Microscope (OQM) is a narrow band visible light microscope capable of measuring both amplitude and phase of a scattered field. We develop a diffraction tomography, that is, wave-based, scattered field inversion and imaging algorithm, for reconstructing the refractive index of the scattering object.

  18. Infrared microscopic investigation of skin biopsies after application of implant material for correction of aesthetic deficiencies

    NASA Astrophysics Data System (ADS)

    Heise, H. M.; Seifert, L.; Kuckuk, R.; Lenzen, C.

    2003-06-01

    Different implant materials are currently applied for correction of inborn and acquired aesthetic deficiencies of the human skin. Several commercial products are used as dermal fillers for aesthetic facial surgery, which contain bovine collagen and cross-linked substances, or hyaluronic acid derivatives, both also in combination with polymethylmethacrylate or co-polymerisates of methacrylate derivatives. Gels containing polylactate or dimethylpolysiloxane were also available. Infrared spectra of such products are presented after dry film preparation. Infrared microscopy using attenuated total reflection was employed to identify previously applied dermal filler products in excised tissue without embedding the sample in a matrix material such as paraffin as needed for microtoming. Several tissue spots guided by inspecting the different color grades were found with increased single implant component concentrations, as supported by the dominating spectral features and difference spectroscopy. The chemistry within dermal biopsies after material implantation can be uniquely investigated based on their infrared spectra.

  19. Characterization of process-induced damage in Cu/low-k interconnect structure by microscopic infrared spectroscopy with polarized infrared light

    NASA Astrophysics Data System (ADS)

    Seki, Hirofumi; Hashimoto, Hideki; Ozaki, Yukihiro

    2016-09-01

    Microscopic Fourier-transform infrared (FT-IR) spectra are measured for a Cu/low-k interconnect structure using polarized IR light for different widths of low-k spaces and Cu lines, and for different heights of Cu lines, on Si substrates. Although the widths of the Cu line and the low-k space are 70 nm each, considerably smaller than the wavelength of the IR light, the FT-IR spectra of the low-k film were obtained for the Cu/low-k interconnect structure. A suitable method was established for measuring the process-induced damage in a low-k film that was not detected by the TEM-EELS (Transmission Electron Microscope-Electron Energy-Loss Spectroscopy) using microscopic IR polarized light. Based on the IR results, it was presumed that the FT-IR spectra mainly reflect the structural changes in the sidewalls of the low-k films for Cu/low-k interconnect structures, and the mechanism of generating process-induced damage involves the generation of Si-OH groups in the low-k film when the Si-CH3 bonds break during the fabrication processes. The Si-OH groups attract moisture and the OH peak intensity increases. It was concluded that the increase in the OH groups in the low-k film is a sensitive indicator of low-k damage. We achieved the characterization of the process-induced damage that was not detected by the TEM-EELS and speculated that the proposed method is applicable to interconnects with line and space widths of 70 nm/70 nm and on shorter scales of leading edge devices. The location of process-induced damage and its mechanism for the Cu/low-k interconnect structure were revealed via the measurement method.

  20. A mirror based scheme of a laser projection microscope

    NASA Astrophysics Data System (ADS)

    Gubarev, F. A.; Li, Lin; Klenovskii, M. S.

    2016-04-01

    The paper discusses the design of a laser projection microscope with a mirror-based scheme of image formation. It is shown that the laser projection microscope with the mirror-based scheme of image formation is well suited for distant objects monitoring. This scheme allowed obtaining a field of view of more than 3 cm at the distance of 4 m from the brightness amplifier

  1. Characterization of Lunar Soils Using a Thermal Infrared Microscopic Spectral Imaging System

    NASA Astrophysics Data System (ADS)

    Crites, S. T.; Lucey, P. G.

    2010-12-01

    Lunar Reconnaissance Orbiter's Diviner radiometer has provided the planetary science community with a large amount of thermal infrared spectral data. This data set offers rich opportunities for lunar science, but interpretation of the data is complicated by the limited data on lunar materials. While spectra of pure terrestrial minerals have been used effectively for Mars applications, lunar minerals and glasses have been affected by space weathering processes that may alter their spectral properties in important ways. For example, mineral grains acquire vapor deposited coatings, and agglutinate glass contains abundant nanophase iron as a result of exposure to the space environment. Producing mineral separates in sufficient quantities (at least tens of mg) for spectral characterization is painstaking, time consuming and labor intensive; as an alternative we have altered an infrared hyperspectral imaging system developed for remote sensing under funding from the Planetary Instrument Definition and Development program (PIDDP) to enable resolved microscopic spectral imaging. The concept is to characterize the spectral properties of individual grains in lunar soils, enabling a wide range of spectral behaviors of components to be measured rapidly. The instrument, sensitive from 8 to 15 microns at 15 wavenumber resolution, images a field of view of 8 millimeters at 30 micron resolution and scans at a rate of about 1 mm/second enabling relatively large areas to be scanned rapidly. Our experiments thus far use a wet-sieved 90-150 um size fraction with the samples arrayed on a heated substrate in a single layer in order to prevent spectral interactions between grains. We have begun with pure mineral separates, and unsurprisingly we find that the individual mineral grain emission spectra of a wide range of silicates are very similar to spectra of coarse grained powders. We have begun to obtain preliminary data on lunar soils as well. We plan to continue imaging of lunar soils

  2. Microscopic dynamics of a base protonation

    NASA Astrophysics Data System (ADS)

    Knudsgaard, Bjørn; Petersen, Christian; Thøgersen, Jan; Keiding, Søren Rud; Jensen, Svend J. Knak

    2008-10-01

    The protonation of the base peroxynitrite in aqueous solution is investigated by way of the Car-Parrinello molecular dynamics technique. It is found that the protonation proceeds through an increase in the vibration amplitude of the hydrogen bond between the base and the hydronium ion. When the amplitude gets sufficiently large a proton may oscillate a few times between the base and the hydronium ion before it remains as part of peroxynitrous acid. The start of the protonation requires a certain orientation of the hydrogen bond. The estimated protonation time agrees well with the one obtained from femtosecond UV experiments.

  3. Multi-perspective scanning microscope based on Talbot effect

    NASA Astrophysics Data System (ADS)

    Sun, Yangyang; Pang, Shuo

    2016-01-01

    We report a multi-perspective scanning microscope based on the Talbot effect of a periodic focal spot array. Talbot illumination decouples the lateral scanning and the focal spots tuning. Large field of view fluorescence Talbot Microscope has been demonstrated by globally changing the incident wavefront gradient. Here, we explore the design freedom of adjusting the wavefront locally within each period and thus engineer the point spread function of the focal spots. We demonstrate an imaging system capable of reconstructing multi-perspective microscopic images in both bright field and fluorescence mode. With the multi-perspective imaging capability, we envision a more robust microscopic imaging system for large field of view fluorescence microscopy applications. This method is also suitable for compact imaging systems for multi-layer microfluidic systems.

  4. Antimonide-based barrier infrared detectors

    NASA Astrophysics Data System (ADS)

    Ting, David Z.; Hill, Cory J.; Soibel, Alexander; Nguyen, Jean; Keo, Sam A.; Lee, Michael C.; Mumolo, Jason M.; Liu, John K.; Gunapala, Sarath D.

    2010-04-01

    The nearly lattice-matched InAs/GaSb/AlSb (antimonide) material system offers tremendous flexibility in realizing high-performance infrared detectors. Antimonide-based alloy and superlattice infrared absorbers can be customized to have cutoff wavelengths ranging from the short wave infrared (SWIR) to the very long wave infrared (VLWIR). They can be used in constructing sophisticated heterostructures to enable advanced infrared photodetector designs. In particular, they facilitate the construction of unipolar barriers, which can block one carrier type but allow the unimpeded flow of the other. Unipolar barriers are used to implement the barrier infra-red detector (BIRD) design for increasing the collection efficiency of photo-generated carriers, and reducing dark current generation without impeding photocurrent flow. We report our recent efforts in achieving state-of-the-art performance in antimonide alloy and superlattice based infrared photodetectors using the BIRD architecture. Specifically, we report a 10 μm cutoff superlattice device based on a complementary barrier infrared detector (CBIRD) design. The detector, without antireflection coating or passivation, exhibits a responsivity of 1.5 A/W and a dark current density of 1×10-5 A/cm2 at 77K under 0.2 V bias. It reaches 300 K background limited infrared photodetection (BLIP) operation at 87 K, with a blackbody BLIP D* value of 1.1×1011 cm-Hz1/2/W for f/2 optics under 0.2 V bias.

  5. Microscopic emission and reflectance thermal infrared spectroscopy: instrumentation for quantitative in situ mineralogy of complex planetary surfaces.

    PubMed

    Edwards, C S; Christensen, P R

    2013-04-10

    The diversity of investigations of planetary surfaces, especially Mars, using in situ instrumentation over the last decade is unprecedented in the exploration history of our solar system. The style of instrumentation that landed spacecraft can support is dependent on several parameters, including mass, power consumption, instrument complexity, cost, and desired measurement type (e.g., chemistry, mineralogy, petrology, morphology, etc.), all of which must be evaluated when deciding an appropriate spacecraft payload. We present a laboratory technique for a microscopic emission and reflectance spectrometer for the analysis of martian analog materials as a strong candidate for the next generation of in situ instruments designed to definitively assess sample mineralogy and petrology while preserving geologic context. We discuss the instrument capabilities, signal and noise, and overall system performance. We evaluate the ability of this instrument to quantitatively determine sample mineralogy, including bulk mineral abundances. This capability is greatly enhanced. Whereas the number of mineral components observed from existing emission spectrometers is high (often >5 to 10 depending on the number of accessory and alteration phases present), the number of mineral components at any microscopic measurement spot is low (typically <2 to 3). Since this style of instrument is based on a long heritage of thermal infrared emission spectrometers sent to orbit (the thermal emission spectrometer), sent to planetary surfaces [the mini-thermal emission spectrometers (mini-TES)], and evaluated in laboratory environments (e.g., the Arizona State University emission spectrometer laboratory), direct comparisons to existing data are uniquely possible with this style of instrument. The ability to obtain bulk mineralogy and atmospheric data, much in the same manner as the mini-TESs, is of significant additional value and maintains the long history of atmospheric monitoring for Mars

  6. Microscopic emission and reflectance thermal infrared spectroscopy: instrumentation for quantitative in situ mineralogy of complex planetary surfaces.

    PubMed

    Edwards, C S; Christensen, P R

    2013-04-10

    The diversity of investigations of planetary surfaces, especially Mars, using in situ instrumentation over the last decade is unprecedented in the exploration history of our solar system. The style of instrumentation that landed spacecraft can support is dependent on several parameters, including mass, power consumption, instrument complexity, cost, and desired measurement type (e.g., chemistry, mineralogy, petrology, morphology, etc.), all of which must be evaluated when deciding an appropriate spacecraft payload. We present a laboratory technique for a microscopic emission and reflectance spectrometer for the analysis of martian analog materials as a strong candidate for the next generation of in situ instruments designed to definitively assess sample mineralogy and petrology while preserving geologic context. We discuss the instrument capabilities, signal and noise, and overall system performance. We evaluate the ability of this instrument to quantitatively determine sample mineralogy, including bulk mineral abundances. This capability is greatly enhanced. Whereas the number of mineral components observed from existing emission spectrometers is high (often >5 to 10 depending on the number of accessory and alteration phases present), the number of mineral components at any microscopic measurement spot is low (typically <2 to 3). Since this style of instrument is based on a long heritage of thermal infrared emission spectrometers sent to orbit (the thermal emission spectrometer), sent to planetary surfaces [the mini-thermal emission spectrometers (mini-TES)], and evaluated in laboratory environments (e.g., the Arizona State University emission spectrometer laboratory), direct comparisons to existing data are uniquely possible with this style of instrument. The ability to obtain bulk mineralogy and atmospheric data, much in the same manner as the mini-TESs, is of significant additional value and maintains the long history of atmospheric monitoring for Mars

  7. Infrared target recognition based on improved joint local ternary pattern

    NASA Astrophysics Data System (ADS)

    Sun, Junding; Wu, Xiaosheng

    2016-05-01

    This paper presents a simple, efficient, yet robust approach, named joint orthogonal combination of local ternary pattern, for automatic forward-looking infrared target recognition. It gives more advantages to describe the macroscopic textures and microscopic textures by fusing variety of scales than the traditional LBP-based methods. In addition, it can effectively reduce the feature dimensionality. Further, the rotation invariant and uniform scheme, the robust LTP, and soft concave-convex partition are introduced to enhance its discriminative power. Experimental results demonstrate that the proposed method can achieve competitive results compared with the state-of-the-art methods.

  8. [Infrared spectroscopy based on quantum cascade lasers].

    PubMed

    Wen, Zhong-Quan; Chen, Gang; Peng, Chen; Yuan, Wei-Qing

    2013-04-01

    Quantum cascade lasers (QCLs) are promising infrared coherent sources. Thanks to the quantum theory and band-gap engineering, QCL can access the wavelength in the range from 3 to 100 microm. Since the fingerprint spectrum of most gases are located in the mid-infrared range, mid-infrared quantum cascade laser based gas sensing technique has become the research focus world wide because of its high power, narrow linewidth and fast scanning. Recent progress in the QCL technology leads to a great improvement in laser output power and efficiency, which stimulates a fast development in the infrared laser spectroscopy. The present paper gives a broad review on the QCL based spectroscopy techniques according to their working principles. A discussion on their applications in gas sensing and explosive detecting is also given at the end of the paper.

  9. Single-channel stereoscopic ophthalmology microscope based on TRD

    NASA Astrophysics Data System (ADS)

    Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

    2016-03-01

    A stereoscopic imaging modality was developed for the application of ophthalmology surgical microscopes. A previous study has already introduced a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (SSVIM-TRD), in which two different view angles, image disparity, are generated by imaging through a transparent rotating deflector (TRD) mounted on a stepping motor and is placed in a lens system. In this case, the image disparity is a function of the refractive index and the rotation angle of TRD. Real-time single-channel stereoscopic ophthalmology microscope (SSOM) based on the TRD is improved by real-time controlling and programming, imaging speed, and illumination method. Image quality assessments were performed to investigate images quality and stability during the TRD operation. Results presented little significant difference in image quality in terms of stability of structural similarity (SSIM). A subjective analysis was performed with 15 blinded observers to evaluate the depth perception improvement and presented significant improvement in the depth perception capability. Along with all evaluation results, preliminary results of rabbit eye imaging presented that the SSOM could be utilized as an ophthalmic operating microscopes to overcome some of the limitations of conventional ones.

  10. Spin microscope based on optically detected magnetic resonance

    DOEpatents

    Berman, Gennady P.; Chernobrod, Boris M.

    2007-12-11

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  11. Spin microscope based on optically detected magnetic resonance

    DOEpatents

    Berman, Gennady P.; Chernobrod, Boris M.

    2010-06-29

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  12. Spin microscope based on optically detected magnetic resonance

    DOEpatents

    Berman, Gennady P.; Chernobrod, Boris M.

    2010-07-13

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  13. Spin microscope based on optically detected magnetic resonance

    DOEpatents

    Berman, Gennady P.; Chernobrod, Boris M.

    2009-10-27

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  14. Spin microscope based on optically detected magnetic resonance

    SciTech Connect

    Berman, Gennady P.; Chernobrod, Boris M.

    2009-11-10

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of impaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  15. Biomimetic, polymer-based microcantilever infrared sensors

    NASA Astrophysics Data System (ADS)

    Mueller, Michael Thomas

    This dissertation describes the initial development of a polymer-based, microcantilever infrared sensor. The development of the sensor is bio-inspired and based upon the long-range infrared sensor found in the pyrophilous jewel beetle Melanophila acuminata, which is able to seek out forest fires from more than 50 km away. Based on several proposed models of the infrared detector found in Melanophila acuminata, as well as published in vivo experiments, the feasibility of polymer-based infrared thermal sensors was explored and developed. Polymer materials were chosen due to their high absorptivity in the infrared range due to vibrational resonance modes characteristic of their organic bonds. Polymeric materials investigated in the course of this work include the polysaccharide and biomaterial chitin, its deacetylated derivative, chitosan, and the work-horse polymer of the semiconductor industry, novolak-resin-based photoresist. Chitin and chitosan are particularly noteworthy polymers for exploration in infrared detection due to their natural absorbance of infrared radiation near the 3 mum and 10 mum bands, which are important for the detection of the temperatures of warm engines and human body temperature, respectively. Because only limited work (primarily focused on electrodeposition) has been focused on the microscale patterning of chitosan, a photolithography process for chitosan and chitin was developed to allow the integration of the material into a variety of microelectromechanical systems processes. In addition to optical/infrared sensing, this process has a variety of potential applications in tissue engineering, protein engineering, and lab-on-a-chip devices. To demonstrate these areas of use, surface functionalization was demonstrated using bioconjugation to attach a protein to a patterned chitosan surface. Thin films of chitosan and chitin were characterized using laser profilometry to identify the effect of temperature on the film stress, and contact

  16. Microscopic roots of alcohol-ketone demixing: infrared spectroscopy of methanol-acetone clusters.

    PubMed

    Kollipost, Franz; Domanskaya, Alexandra V; Suhm, Martin A

    2015-03-19

    Infrared spectra of isolated methanol-acetone clusters up to tetramers are experimentally characterized for the first time. They show evidence for a nanometer-scale demixing trend of the cold species. In combination with quantum calculations, the mutual repulsion is demonstrated to start beyond three molecular units, whereas individual molecules still prefer to form a mixed complex.

  17. Infrared Imaging for Inquiry-Based Learning

    ERIC Educational Resources Information Center

    Xie, Charles; Hazzard, Edmund

    2011-01-01

    Based on detecting long-wavelength infrared (IR) radiation emitted by the subject, IR imaging shows temperature distribution instantaneously and heat flow dynamically. As a picture is worth a thousand words, an IR camera has great potential in teaching heat transfer, which is otherwise invisible. The idea of using IR imaging in teaching was first…

  18. Microscopic cell nuclei segmentation based on adaptive attention window.

    PubMed

    Ko, ByoungChul; Seo, MiSuk; Nam, Jae-Yeal

    2009-06-01

    This paper presents an adaptive attention window (AAW)-based microscopic cell nuclei segmentation method. For semantic AAW detection, a luminance map is used to create an initial attention window, which is then reduced close to the size of the real region of interest (ROI) using a quad-tree. The purpose of the AAW is to facilitate background removal and reduce the ROI segmentation processing time. Region segmentation is performed within the AAW, followed by region clustering and removal to produce segmentation of only ROIs. Experimental results demonstrate that the proposed method can efficiently segment one or more ROIs and produce similar segmentation results to human perception. In future work, the proposed method will be used for supporting a region-based medical image retrieval system that can generate a combined feature vector of segmented ROIs based on extraction and patient data.

  19. Integrated windows-based control system for an electron microscope

    NASA Astrophysics Data System (ADS)

    Ruan, Shengyang; Kapp, Oscar H.

    1994-12-01

    A Windows application has been developed for management and operation of beam instruments such as electron or ion microscopes. It provides a facility that allows an operator to manage a complicated instrument with minimal effort, primarily under mouse control. The hardware control components used on similar instruments (e.g., the scanning transmission electron microscopes in our lab), such as toggles, buttons, and potentiometers for adjustments on various scales, are all replaced by the controls of the Windows application and are addressable on a single screen. The new controls in this program (via adjustable software settings) offer speed of response and smooth operation providing tailored control of various instrument parameters. Along with the controls offering single parameter adjustment, a two-dimensional control was developed that allows two parameters to be coupled and addressed simultaneously. This capability provides convenience for such tasks as ``finding the beam'' and directing it to a location of interest on the specimen. Using an icon-based display, this Windows application provides better integrated and more robust information for monitoring instrument status than the indicators and meters of the traditional instrument controls. As a Windows application, this program is naturally able to share the resources of the Windows system and is thus able to link to many other applications such as our image acquisition and processing programs. Computer control provides automatic protection and instant diagnostics for the experimental instrument. This Windows application is fully functional and is in daily use to control a new type of electron microscope developed in our lab.

  20. Microscopic derivation of particle-based coarse-grained dynamics

    NASA Astrophysics Data System (ADS)

    Izvekov, Sergei

    2013-04-01

    In this paper we revisit the derivation of equations of motion for coarse-grained (CG) particles from the microscopic Hamiltonian dynamics of the underlying atomistic system in equilibrium. The derivation is based on the projection operator method and time-convolution equation. We demonstrate that due to the energy exchange between CG and intraparticle phase space coordinates in the microscopic system, the choice of projection operator is not unique, leading to different CG equations of motion that have the form of the nonlinear generalized Langevin equation (GLE). We derive the idempotence properties for the projection operators along the system trajectories and show that these properties result in streaming terms of the respective GLEs that are conservative forces and allow the expression of the non-conservative forces explicitly through thermodynamic averages, which can be measured from the microscopic simulations. The difference between GLEs that are presented herein lies in how the non-conservative forces are partitioned into dissipative and projected contributions. We compute the projected force and analyze conditions under which the projected (stochastic) force is orthogonal to (uncorrelated with) the momenta of CG particles, therefore justifying a transition to a framework of stochastic differential equations. We show that a position- and momentum-independent memory function appears only if the projected force is fully decoupled from the past CG positions and momenta, respectively. In the case of non-vanishing correlations between the projected force and the CG coordinates in past times, we derive explicitly the position- and momentum-dependent memory function in a form of projection onto a space spanned by N-order Hermite polynomials. The expressions presented herein can be used to construct a hierarchy of thermodynamically consistent CG models with momentum-dependent memory functions. They can also be used to design computational schemes for obtaining the

  1. Microscopic derivation of particle-based coarse-grained dynamics.

    PubMed

    Izvekov, Sergei

    2013-04-01

    In this paper we revisit the derivation of equations of motion for coarse-grained (CG) particles from the microscopic Hamiltonian dynamics of the underlying atomistic system in equilibrium. The derivation is based on the projection operator method and time-convolution equation. We demonstrate that due to the energy exchange between CG and intraparticle phase space coordinates in the microscopic system, the choice of projection operator is not unique, leading to different CG equations of motion that have the form of the nonlinear generalized Langevin equation (GLE). We derive the idempotence properties for the projection operators along the system trajectories and show that these properties result in streaming terms of the respective GLEs that are conservative forces and allow the expression of the non-conservative forces explicitly through thermodynamic averages, which can be measured from the microscopic simulations. The difference between GLEs that are presented herein lies in how the non-conservative forces are partitioned into dissipative and projected contributions. We compute the projected force and analyze conditions under which the projected (stochastic) force is orthogonal to (uncorrelated with) the momenta of CG particles, therefore justifying a transition to a framework of stochastic differential equations. We show that a position- and momentum-independent memory function appears only if the projected force is fully decoupled from the past CG positions and momenta, respectively. In the case of non-vanishing correlations between the projected force and the CG coordinates in past times, we derive explicitly the position- and momentum-dependent memory function in a form of projection onto a space spanned by N-order Hermite polynomials. The expressions presented herein can be used to construct a hierarchy of thermodynamically consistent CG models with momentum-dependent memory functions. They can also be used to design computational schemes for obtaining the

  2. [Multiple transmission electron microscopic image stitching based on sift features].

    PubMed

    Li, Mu; Lu, Yanmeng; Han, Shuaihu; Wu, Zhuobin; Chen, Jiajing; Liu, Zhexing; Cao, Lei

    2015-08-01

    We proposed a new stitching method based on sift features to obtain an enlarged view of transmission electron microscopic (TEM) images with a high resolution. The sift features were extracted from the images, which were then combined with fitted polynomial correction field to correct the images, followed by image alignment based on the sift features. The image seams at the junction were finally removed by Poisson image editing to achieve seamless stitching, which was validated on 60 local glomerular TEM images with an image alignment error of 62.5 to 187.5 nm. Compared with 3 other stitching methods, the proposed method could effectively reduce image deformation and avoid artifacts to facilitate renal biopsy pathological diagnosis. PMID:26403733

  3. All-optical optoacoustic microscope based on wideband pulse interferometry.

    PubMed

    Wissmeyer, Georg; Soliman, Dominik; Shnaiderman, Rami; Rosenthal, Amir; Ntziachristos, Vasilis

    2016-05-01

    Optical and optoacoustic (photoacoustic) microscopy have been recently joined in hybrid implementations that resolve extended tissue contrast compared to each modality alone. Nevertheless, the application of the hybrid technique is limited by the requirement to combine an optical objective with ultrasound detection collecting signal from the same micro-volume. We present an all-optical optoacoustic microscope based on a pi-phase-shifted fiber Bragg grating (π-FBG) with coherence-restored pulsed interferometry (CRPI) used as the interrogation method. The sensor offers an ultra-small footprint and achieved higher sensitivity over piezoelectric transducers of similar size. We characterize the spectral bandwidth of the ultrasound detector and interrogate the imaging performance on phantoms and tissues. We show the first optoacoustic images of biological specimen recorded with π-FBG sensors. We discuss the potential uses of π-FBG sensors based on CRPI. PMID:27128047

  4. Quantitative zonal differentiation of articular cartilage by microscopic magnetic resonance imaging, polarized light microscopy, and Fourier-transform infrared imaging.

    PubMed

    Lee, Ji Hyun; Xia, Yang

    2013-06-01

    This study aimed to synchronize the zonal differentiation of the full-thickness articular cartilage by three micro-imaging techniques, namely microscopic magnetic resonance imaging (µMRI), polarized light microscopy (PLM), and Fourier-transform infrared imaging (FTIRI). Eighteen cartilage-bone blocks from three canine humeral joints were imaged by: (a) µMRI T2 relaxation at 0° and 55° orientations in a 7 T magnetic field, (b) PLM optical retardation and azimuthal angle, and (c) FTIRI amide I and amide II anisotropies at 0° and 90° polarizations relative to the articular surface. In addition, µMRI T1 relaxation was imaged before and after the tissue being immersed in gadolinium (contrast agent) solution, to calculate the proteoglycan concentration. A set of previously established criteria in cartilage imaging was revised. The new criteria could simultaneously correlate the thicknesses of the three consecutive subtissue zones in articular cartilage among these imaging techniques.

  5. Near-infrared detection of potential evidence for microscopic organisms on Europa

    NASA Technical Reports Server (NTRS)

    Dalton, J. Brad; Mogul, Rakesh; Kagawa, Hiromi K.; Chan, Suzanne L.; Jamieson, Corey S.

    2003-01-01

    The possibility of an ocean within the icy shell of Jupiter's moon Europa has established that world as a primary candidate in the search for extraterrestrial life within our Solar System. This paper evaluates the potential to detect evidence for microbial life by comparing laboratory studies of terrestrial microorganisms with measurements from the Galileo Near Infrared Imaging Spectrometer (NIMS). If the interior of Europa at one time harbored life, some evidence may remain in the surface materials. Examination of laboratory spectra of terrestrial extremophiles measured at cryogenic temperatures reveals distorted, asymmetric nearinfrared absorption features due to water of hydration. The band centers, widths, and shapes of these features closely match those observed in the Europa spectra. These features are strongest in reddish-brown, disrupted terrains such as linea and chaos regions. Narrow spectral features due to amide bonds in the microbe proteins provide a means of constraining the abundances of such materials using the NIMS data. The NIMS data of disrupted terrains exhibit distorted, asymmetric near-infrared absorption features consistent with the presence of water ice, sulfuric acid octahydrate, hydrated salts, and possibly as much as 0.2 mg cm(-3) of carbonaceous material that could be of biological origin. However, inherent noise in the observations and limitations of spectral sampling must be taken into account when discussing these findings.

  6. Near-infrared detection of potential evidence for microscopic organisms on Europa.

    PubMed

    Dalton, J Brad; Mogul, Rakesh; Kagawa, Hiromi K; Chan, Suzanne L; Jamieson, Corey S

    2003-01-01

    The possibility of an ocean within the icy shell of Jupiter's moon Europa has established that world as a primary candidate in the search for extraterrestrial life within our Solar System. This paper evaluates the potential to detect evidence for microbial life by comparing laboratory studies of terrestrial microorganisms with measurements from the Galileo Near Infrared Imaging Spectrometer (NIMS). If the interior of Europa at one time harbored life, some evidence may remain in the surface materials. Examination of laboratory spectra of terrestrial extremophiles measured at cryogenic temperatures reveals distorted, asymmetric nearinfrared absorption features due to water of hydration. The band centers, widths, and shapes of these features closely match those observed in the Europa spectra. These features are strongest in reddish-brown, disrupted terrains such as linea and chaos regions. Narrow spectral features due to amide bonds in the microbe proteins provide a means of constraining the abundances of such materials using the NIMS data. The NIMS data of disrupted terrains exhibit distorted, asymmetric near-infrared absorption features consistent with the presence of water ice, sulfuric acid octahydrate, hydrated salts, and possibly as much as 0.2 mg cm(-3) of carbonaceous material that could be of biological origin. However, inherent noise in the observations and limitations of spectral sampling must be taken into account when discussing these findings. PMID:14678661

  7. Highly charged ion based time of flight emission microscope

    DOEpatents

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  8. Research on infrared imaging illumination model based on materials

    NASA Astrophysics Data System (ADS)

    Hu, Hai-he; Feng, Chao-yin; Guo, Chang-geng; Zheng, Hai-jing; Han, Qiang; Hu, Hai-yan

    2013-09-01

    In order to effectively simulate infrared features of the scene and infrared high light phenomenon, Based on the visual light illumination model, according to the optical property of all material types in the scene, the infrared imaging illumination models are proposed to fulfill different materials: to the smooth material with specular characteristic, adopting the infrared imaging illumination model based on Blinn-Phone reflection model and introducing the self emission; to the ordinary material which is similar to black body without highlight feature, ignoring the computation of its high light reflection feature, calculating simply the material's self emission and its reflection to the surrounding as its infrared imaging illumination model, the radiation energy under zero range of visibility can be obtained according to the above two models. The OpenGl rendering technology is used to construct infrared scene simulation system which can also simulate infrared electro-optical imaging system, then gets the synthetic infrared images from any angle of view of the 3D scenes. To validate the infrared imaging illumination model, two typical 3D scenes are made, and their infrared images are calculated to compare and contrast with the real collected infrared images obtained by a long wave infrared band imaging camera. There are two major points in the paper according to the experiment results: firstly, the infrared imaging illumination models are capable of producing infrared images which are very similar to those received by thermal infrared camera; secondly, the infrared imaging illumination models can simulate the infrared specular feature of relative materials and common infrared features of general materials, which shows the validation of the infrared imaging illumination models. Quantitative analysis shows that the simulation images are similar to the collected images in the aspects of main features, but their histogram distribution does not match very well, the

  9. [Myanmar jadeitite low-temperature metamorphic water-rock reaction: eveidence from microscopic fourier transform infrared spectroscopy].

    PubMed

    Yan, Ruo-Gu; Qiu, Zhi-Li; Feng, Ming; Jin, Chun-Mei; Li, Liu-Fen; Shi, Gui-Yong; Wang, Ping

    2014-09-01

    Weathering & transporting and depositing processes may improve the quality of some natural low-quality jadeite through reaction with surrounding water fluids. But the mechanism of such water-rock reaction has not been known clearly to date. Applying microscopic Fourier transform infrared spectroscopy (Micro-FTIR), this paper carried out comparatively in-situ research of jadeites' mineral composition before and after water-rock reaction. The results show that water-rock reaction cannot impact jadeites in their major and minor element composition, but greatly change their water content. Jadeites became richer, with even several times increase, in water content, after experiencing water-rock reaction, and hence show a shift of absorption peak at 3 550 cm(-1) to higher frequency. The mineral crystals of these jadeites showed reglar variation in water content from core to edge, and these jadeites have more water in marginal area than in center area, being opposite to the change in water content in jadeite during high temperature and pressure metamorphic process, hence implying that there are different mechanism and shift direction for H+/OH of jadeite between high pressure metamorphic process and low temperature water-rock reaction. We think that this finding may contribute to understanding the behavior of water in jadeite during metamorphic process and the mechanism of jadeite quality improvement. PMID:25532333

  10. [Myanmar jadeitite low-temperature metamorphic water-rock reaction: eveidence from microscopic fourier transform infrared spectroscopy].

    PubMed

    Yan, Ruo-Gu; Qiu, Zhi-Li; Feng, Ming; Jin, Chun-Mei; Li, Liu-Fen; Shi, Gui-Yong; Wang, Ping

    2014-09-01

    Weathering & transporting and depositing processes may improve the quality of some natural low-quality jadeite through reaction with surrounding water fluids. But the mechanism of such water-rock reaction has not been known clearly to date. Applying microscopic Fourier transform infrared spectroscopy (Micro-FTIR), this paper carried out comparatively in-situ research of jadeites' mineral composition before and after water-rock reaction. The results show that water-rock reaction cannot impact jadeites in their major and minor element composition, but greatly change their water content. Jadeites became richer, with even several times increase, in water content, after experiencing water-rock reaction, and hence show a shift of absorption peak at 3 550 cm(-1) to higher frequency. The mineral crystals of these jadeites showed reglar variation in water content from core to edge, and these jadeites have more water in marginal area than in center area, being opposite to the change in water content in jadeite during high temperature and pressure metamorphic process, hence implying that there are different mechanism and shift direction for H+/OH of jadeite between high pressure metamorphic process and low temperature water-rock reaction. We think that this finding may contribute to understanding the behavior of water in jadeite during metamorphic process and the mechanism of jadeite quality improvement.

  11. A fiber-laser-based stimulated Raman scattering spectral microscope

    NASA Astrophysics Data System (ADS)

    Nose, Keisuke; Ozeki, Yasuyuki; Kishi, Tatsuya; Sumimura, Kazuhiko; Kanematsu, Yasuo; Itoh, Kazuyoshi

    2013-02-01

    Stimulated Raman scattering (SRS) spectral microscopy is a powerful technique for label-free biological imaging because it allows us to distinguish chemical species with overlapping Raman bands. Here we present an SRS spectral microscope based only on fiber lasers (FL's), which offer the possibilities of downsizing and simplification of the system. A femtosecond figure-8 Er-FL at a repetition rate of 54.4 MHz is used to generate pump pulses. After amplified by an Er doped fiber amplifier, Er-FL pulses are spectrally compressed to 2-ps second harmonic pulses. For generating Stokes pulses, a femtosecond Yb-FL pulses at a repetition rate of 27.2 MHz is used. Then these lasers are synchronized by a phase locked loop, which consists of a two-photon absorption photodetector, a loop filter, a phase modulator in the Er- FL cavity, and a piezo electric transducer in the Yb-FL cavity. The intensity noise of pump pulses is reduced by the collinear balanced detection (CBD) technique based on delay-and-add fiber lines. Experimentally, we confirmed that the intensity noise level of probe pulses was close to the shot noise limit. The Stokes pulses are introduced to a wavelength tunable band pass filter (BPF), which consists of a galvanomirror scanner, a 4-f optical system, a reflection grating, and a collimator. This system is able to scan the wavenumber from 2850 cm-1 to 3100 cm-1 by tuning the BPF. We succeeded in the spectral imaging of a mixture of polystyrene beads and poly(methyl methacrylate) beads.

  12. Optical microscope combined with the nanopipette-based quartz tuning fork-atomic force microscope for nanolithography

    NASA Astrophysics Data System (ADS)

    An, Sangmin; Stambaugh, Corey; Kwon, Soyoung; Lee, Kunyoung; Kim, Bongsu; Kim, Qwhan; Jhe, Wonho

    2013-09-01

    We demonstrated the optical microscope (OM) combined with nanopipette-based quartz tuning fork - atomic force microscope (QTF-AFM) for nanolithography. The nanoparticle (Au, 5 nm), nanowire, PDMS solutions are ejected onto the substrate through the nano/microaperture of the pulled pipette, and the nano/microscale objects were in-situ formed on the surface with the proposed patterning system, while the position is defined by monitoring the phenomena on the substrate with a home-made OM. After forming of capillary condensation between apex of the pipette tip and the surface, the electric field is applied to extract out the inside liquid to the substrate and the nano/microscale objects are fabricated. The nanoscale patterning size can be controlled by the aperture diameters of the pulled pipette.

  13. [Bone Cell Biology Assessed by Microscopic Approach. Assessment of bone quality using Raman and infrared spectroscopy].

    PubMed

    Suda, Hiromi Kimura

    2015-10-01

    Bone quality, which was defined as "the sum total of characteristics of the bone that influence the bone's resistance to fracture" at the National Institute of Health (NIH) conference in 2001, contributes to bone strength in combination with bone mass. Bone mass is often measured as bone mineral density (BMD) and, consequently, can be quantified easily. On the other hand, bone quality is composed of several factors such as bone structure, bone matrix, calcification degree, microdamage, and bone turnover, and it is not easy to obtain data for the various factors. Therefore, it is difficult to quantify bone quality. We are eager to develop new measurement methods for bone quality that make it possible to determine several factors associated with bone quality at the same time. Analytic methods based on Raman and FTIR spectroscopy have attracted a good deal of attention as they can provide a good deal of chemical information about hydroxyapatite and collagen, which are the main components of bone. A lot of studies on bone quality using Raman and FTIR imaging have been reported following the development of the two imaging systems. Thus, both Raman and FTIR imaging appear to be promising new bone morphometric techniques.

  14. Electrowetting based infrared lens using ionic liquids

    NASA Astrophysics Data System (ADS)

    Hu, Xiaodong; Zhang, Shiguo; Liu, Yu; Qu, Chao; Lu, Liujin; Ma, Xiangyuan; Zhang, Xiaoping; Deng, Youquan

    2011-11-01

    We demonstrated an infrared variable focus ionic liquids lens using electrowetting, which could overcome the problems caused by use of water, e.g., evaporation and poor thermostability, while keeping good optical transparency in visible light and near-infrared region. Besides, the type of lens (convex or concave) could be tuned by applied voltage or refractive index of ILs used, and the transmittance was measured to exceed 90% over the spectrum of visible light and near-infrared. We believe this infrared variable focus ionic liquids lens has a great application prospect in both visible light and infrared image systems.

  15. Black silicon-based infrared radiation source

    NASA Astrophysics Data System (ADS)

    Anwar, Momen; Sabry, Yasser; Basset, Philippe; Marty, Frédéric; Bourouina, Tarik; Khalil, Diaa

    2016-03-01

    Micromachined infrared sources are enabling component for interferometric and spectroscopic sensors. Their compact size and low cost transform bulky instruments to the sensor scale, which is needed for a wide range of applications in the conventional and unconventional environments. The silicon micromachined sources should be engineered to have good emissivity across a large wavelength range because the intrinsic emissivity of silicon is low. This optimization was reported in literature by either the deposition of black metal at the surface of an emitter or the use of deep phonic crystal cavities, which complicates the fabrication technology and results in sharp dip lines in the spectral emissivity, respectively. In this work we report a micromachined infrared radiation source based on a heater on the top of black silicon structure for the first time in the literature, up to the authors' knowledge. The temperature of the device is characterized versus the applied voltage and the radiated spectrum is captured in the 1300 nm to 2500 nm spectral range; limited by the spectrum analysis instrument. The reported source opens the doors for completely integrated MEMS spectral sensors onchip.

  16. Adaptive enhancement method of infrared image based on scene feature

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Bai, Tingzhu; Shang, Fei

    2008-12-01

    All objects emit radiation in amounts related to their temperature and their ability to emit radiation. The infrared image shows the invisible infrared radiation emitted directly. Because of the advantages, the technology of infrared imaging is applied to many kinds of fields. But compared with visible image, the disadvantages of infrared image are obvious. The characteristics of low luminance, low contrast and the inconspicuous difference target and background are the main disadvantages of infrared image. The aim of infrared image enhancement is to improve the interpretability or perception of information in infrared image for human viewers, or to provide 'better' input for other automated image processing techniques. Most of the adaptive algorithm for image enhancement is mainly based on the gray-scale distribution of infrared image, and is not associated with the actual image scene of the features. So the pertinence of infrared image enhancement is not strong, and the infrared image is not conducive to the application of infrared surveillance. In this paper we have developed a scene feature-based algorithm to enhance the contrast of infrared image adaptively. At first, after analyzing the scene feature of different infrared image, we have chosen the feasible parameters to describe the infrared image. In the second place, we have constructed the new histogram distributing base on the chosen parameters by using Gaussian function. In the last place, the infrared image is enhanced by constructing a new form of histogram. Experimental results show that the algorithm has better performance than other methods mentioned in this paper for infrared scene images.

  17. Undulator based scanning microscope at the National Synchrotron Light Source

    SciTech Connect

    Rarback, H.; Shu, D.; Ade, H.; Jacobsen, C.; Kirz, J.; McNulty, I.; Rosser, R.

    1986-01-01

    A second generation scanning soft x-ray microscope is under construction, designed to utilize the dramatic increase in source bightness available at the soft x-ray undulator. The new instrument is expected to reduce image acquisition time by a factor of about 100, and to improve resolution, stability, and reproducibility.

  18. Near-infrared microscopic methods for the detection and quantification of processed by-products of animal origin

    NASA Astrophysics Data System (ADS)

    Abbas, O.; Fernández Pierna, J. A.; Dardenne, P.; Baeten, V.

    2010-04-01

    Since the BSE crisis, researches concern mainly the detection, identification, and quantification of meat and bone meal with an important focus on the development of new analytical methods. Microscopic based spectroscopy methods (NIR microscopy - NIRM or/and NIR hyperspectral imaging) have been proposed as complementary methods to the official method; the optical microscopy. NIR spectroscopy offers the advantage of being rapid, accurate and independent of human analyst skills. The combination of an NIR detector and a microscope or a camera allows the collection of high quality spectra for small feed particles having a size larger than 50 μm. Several studies undertaken have demonstrated the clear potential of NIR microscopic methods for the detection of animal particles in both raw and sediment fractions. Samples are sieved and only the gross fraction (superior than 250 μm) is investigated. Proposed methodologies have been developed to assure, with an acceptable level of confidence (95%), the detection of at least one animal particle when a feed sample is adulterated at a level of 0.1%. NIRM and NIR hyperspectral imaging are running under accreditation ISO 17025 since 2005 at CRA-W. A quantitative NIRM approach has been developed in order to fulfill the new requirements of the European commission policies. The capacities of NIRM method have been improved; only the raw fraction is analyzed, both the gross and the fine fractions of the samples are considered, and the acquisition parameters are optimized (the aperture, the gap, and the composition of the animal feed). A mapping method for a faster collection of spectra is also developed. The aim of this work is to show the new advances in the analytical methods developed in the frame of the feed ban applied in Europe.

  19. Satellite Characterization of Biomass Burning: Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope Study of Combustion Experiments

    NASA Astrophysics Data System (ADS)

    Padilla, D.; Steiner, J. C.

    2005-12-01

    Fourier Transform Infrared (FTIR) examination of the combustion products of selected forest materials using a meeker burner flame at temperatures up to 500 degrees Celsius produces a cluster of broad distinct peaks throughout the 400 to 4000 cm-1 wavenumber interval. Distinct bands bracketed by wavenumbers 400-700, 1500-1700, 2200-2400 and 3300-3600 cm-1 show variable intensity with an average difference between the least absorbing and most strongly absorbing species of approximately fifty percent. Given that spectral band differences of ten percent are within the range of modern satellite spectrometers, these band differences are of potential value for discriminating between fires that are impacting a range of vegetation types. Corresponding scanning electron microscope and energy dispersive micro-chemical (SEM/ED) analysis establishes that the evolved soot particles exhibit a characteristic rounded morphology, are carbon rich and host a wide range of adsorbed elements, including calcium, aluminum, potassium, silicon, sulfur and trace nitrogen. Combustion experiments involving leaves and branches as a subset of the biomass experiments at 200-500 degrees Celsius yield a similar broad background, but with peak shifts for maxima residing at less than 1700 cm-1. Additional peaks appear in the ranges 1438-1444, 875 and 713 cm-1. These peak are of potential use for discriminating between hot and smoldering fires, and between soot and smoke yields from green woods and whole-wood or lumber. The spectral shifts noted for low temperature smoldering conditions are in the vicinity of those cited for green vegetation and may not be resolved by present satellite platforms. Nevertheless, the experimental peak data set is of potential use for discriminating between a conflagration or accentuated fire and one characterized by smoldering at low temperature. SEM/ED analysis of the combusted leaf, branch, bark and various crown assemblages yields comparable morphological and

  20. Infrared/submillimeter optical properties data base

    NASA Technical Reports Server (NTRS)

    Alley, Phillip W.

    1989-01-01

    The general goal was to build a data base containing optical properties, such as reflectance, transmittance, refractive index, in the far infrared to submillimeter wavelength region. This data base would be limited to selected crystalline materials and temperature between 300 and 2 K. The selected materials were: lithium, lead, and strontium; the bromides of potassium and thallium; the carbides of silicone and tungsten; and the materials of KRS5, KRS6, diamond, and sapphire. Last summer, barium fluoride was selected as prototype material for building the data base. This summer the literature search, preparation of the data for barium fluoride was completed. In addition the literature search for data related to the compounds mentioned was completed. The current status is that barium fluoride is in a form suitable for a NASA internal publication. The papers containing the data on the other materials were xeroxed and they are ready to be reduced. On the reverse side, the top figure is a sample combination of data for the index of refraction at 300 K. The lower figure shows the transmittance vs wavelength at 300 and 80 K. These figures are a sample of many which were developed. Since barium fluoride was studied more than most of the materials listed above, it is clear that additional measurements should be made to fill in the gaps present on both temperature and wavelength data.

  1. Infrared Imaging for Inquiry-Based Learning

    NASA Astrophysics Data System (ADS)

    Xie, Charles; Hazzard, Edmund

    2011-09-01

    Based on detecting long-wavelength infrared (IR) radiation emitted by the subject, IR imaging shows temperature distribution instantaneously and heat flow dynamically. As a picture is worth a thousand words, an IR camera has great potential in teaching heat transfer, which is otherwise invisible. The idea of using IR imaging in teaching was first discussed by Vollmer et al. in 2001.1-3 IR cameras were then too expensive for most schools. Thanks to the growing need of home energy inspection using IR thermography, the price of IR cameras has plummeted and they have become easy to use. As of 2011, the price of an entry-level handheld IR camera such as the FLIR I3 has fallen below 900 for educators. A slightly better version, FLIR I5, was used to take the IR images in this paper. As easy to use as a digital camera, the I5 camera automatically generates IR images of satisfactory quality with a temperature sensitivity of 0.1°C. The purpose of this paper is to demonstrate how these affordable IR cameras can be used as a visualization, inquiry, and discovery tool. As the prices of IR cameras continue to drop, it is time to give teachers an update about the educational power of this fascinating tool, especially in supporting inquiry-based learning.

  2. Interactive intraoperative localization using an infrared-based system.

    PubMed

    Zamorano, L J; Nolte, L; Kadi, A M; Jiang, Z

    1993-10-01

    We discuss new methods of localizing and treating brain lesions for both the conventional method of a base-ring fixed to the patient's skull (referred to as frame-based procedures) and the new method of frameless procedures (no base ring). Frame-based procedures are used for finding a precise instrument position during neurosurgical procedures, such as stereotactic biopsy of deep-seated lesions, placing electrodes for functional stereotaxis or catheters with radioactive seeds for brachytherapy, or even the placement of a stereotactic retractor or endoscope for removal or internal decompression of lesions. In such procedures, the intraoperative image localization of instruments becomes useful as it tracks instruments as they travel through the preplanned trajectory. Additional intraoperative digitization of surgical instruments, e.g., bipolar suction, biopsy forceps, microscope, ultrasound probe, etc, can be achieved during the stereotactic resection of eloquent areas or deep intracranial lesions by adding an infrared-based system. Frameless procedures broaden the range of surgical approaches, image guidance planning, and operative procedures, since no ring is attached to the patient's head which might interfere with the surgical approach, and offers logistic advantages in scheduling diagnostic studies. Frameless diagnostic studies employ anatomical markers and/or surface matching techniques for data registration in the computer software surgical preplanning program. This simplifies scheduling of the procedures since the image study does not need to be acquired the same day as surgery. Frameless diagnostic studies allow for the use of more than one type of imaging data for planning and optimization of surgical procedures, and greatly improve patient tolerance and comfort during these procedures and during surgery, as compared with frame-based procedures.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7905601

  3. A stacking-fault based microscopic model for platelets in diamond

    NASA Astrophysics Data System (ADS)

    Antonelli, Alex; Nunes, Ricardo

    2005-03-01

    We propose a new microscopic model for the 001 planar defects in diamond commonly called platelets. This model is based on the formation of a metastable stacking fault, which can occur because of the ability of carbon to stabilize in different bonding configurations. In our model the core of the planar defect is basically a double layer of three-fold coordinated sp^2 carbon atoms embedded in the common sp^3 diamond structure. The properties of the model were determined using ab initio total energy calculations. All significant experimental signatures attributed to the platelets, namely, the lattice displacement along the [001] direction, the asymmetry between the [110] and the [11 0] directions, the infrared absorption peak B^' , and broad luminescence lines that indicate the introduction of levels in the band gap, are naturally accounted for in our model. The model is also very appealing from the point of view of kinetics, since naturally occurring shearing processes will lead to the formation of the metastable fault.Authors acknowledge financial support from the Brazilian agencies FAPESP, CNPq, FAEP-UNICAMP, FAPEMIG, and Instituto do Milênio em Nanociências-MCT

  4. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  5. A scanning acoustic microscope based on picosecond ultrasonics.

    PubMed

    Che, S; Guduru, P R; Nurmikko, A V; Maris, H J

    2015-02-01

    We report on the development of a new type of scanning acoustic microscope. We use a femtosecond light pulse to generate a short sound pulse, and then focus this sound onto the sample by means of a specially designed and microfabricated acoustic lens of radius a few microns. The sound travels to the sample through a thin layer of water. The sound reflected from the sample is collected by the lens and then passes through a monolithically integrated optical resonant cavity. The induced change in the properties of this cavity are measured using a time-delayed probe light pulse. We describe some of the challenges involved in the construction and operation of this high-precision metrology apparatus and present some preliminary results.

  6. Martian Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

  7. SOFI-based 3D superresolution sectioning with a widefield microscope

    PubMed Central

    Dertinger, Thomas; Xu, Jianmin; Naini, Omeed Foroutan; Vogel, Robert; Weiss, Shimon

    2013-01-01

    Background Fluorescence-based biological imaging has been revolutionized by the recent introduction of superresolution microscopy methods. 3D superresolution microscopy, however, remains a challenge as its implementation by existing superresolution methods is non-trivial. Methods Here we demonstrate a facile and straightforward 3D superresolution imaging and sectioning of the cytoskeletal network of a fixed cell using superresolution optical fluctuation imaging (SOFI) performed on a conventional lamp-based widefield microscope. Results and Conclusion SOFI’s inherent sectioning capability effectively transforms a conventional widefield microscope into a superresolution ‘confocal widefield’ microscope. PMID:24163789

  8. Shape quantification of single red blood cells based on their scattering patterns from microscopic images

    NASA Astrophysics Data System (ADS)

    Schneider, Gert; Artmann, Gerhard

    1995-02-01

    The differentiation between discocytic and stomatocytic red blood cell (RBC) shape using conventional microscopic imaging and image analysis tools is still on a very poor level. A procedure to differentiate the degree of stomatocytic shape changes was developed. We obtained multiple microscopic images of the same RBCs settled on a human albumin coated cover slip. The images were acquired when the microscope objective was subsequently focused through the cell layer. At equidistant horizontal planes (z-axis) below, within, and above the microscopic focal plane the light intensity distribution was considered. Using a model based on light refraction, we calculated the intensity distribution of the planes which are out of focus. Using this tool we are able to differentiate RBC shapes precisely. On the other hand, using this model from and the light intensity distributions of different focal planes, we are able to reconstruct the shape of one single RBC located in the optical axis of the microscope.

  9. Miniature transmissive DLP-based infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Koudsi, Badia; Refai, Hakki

    2016-02-01

    Spectroscopic measurements have the potential to positively impact a wide range of research, development, monitoring and control applications. In many cases, this potential is not realized because the spectrometer cannot be brought out of the laboratory to the measurement site due to sensitivities to environmental factors, highly accurate data cannot be obtained in a timely manner, or customizing the spectrometer to a specific application is costly and precludes re-use of the device for other application once its original purpose is served. We present the development of a DLP-based spectroscopic system in the near-infrared that is low-cost, compact and rugged, provides high resolution and is highly adaptable through straightforward software control. The key elements of the design include an efficient and compact optical pathway, a high-resolution DMD controlled by a fast DLP board, and a user-friendly, feature-rich software package that facilitates system configuration and data analysis. The DMD replaces the detector array in traditional spectrometers, and is shown to provide greater functionality while eliminating the need for mechanical scanning. We demonstrate how the long, thin columns of mirrors in the DMD provide high wavelength selectivity and capture more light at each wavelength, increasing measurement SNR. Selectively activating columns of mirrors is shown to adaptively tailor the resolution and the wavelengths collected and analyzed by the system allow one device to meet the needs of many different applications and to reduce measurement times. The software interface developed for accessing the many features of the spectrometer is discussed.

  10. Microscopic transport model animation visualisation on KML base

    NASA Astrophysics Data System (ADS)

    Yatskiv, I.; Savrasovs, M.

    2012-10-01

    By reading classical literature devoted to the simulation theory it could be found that one of the greatest possibilities of simulation is the ability to present processes inside the system by animation. This gives to the simulation model additional value during presentation of simulation results for the public and authorities who are not familiar enough with simulation. That is why most of universal and specialised simulation tools have the ability to construct 2D and 3D representation of the model. Usually the development of such representation could take much time and there must be put a lot forces into creating an adequate 3D representation of the model. For long years such well-known microscopic traffic flow simulation software tools as VISSIM, AIMSUN and PARAMICS have had a possibility to produce 2D and 3D animation. But creation of realistic 3D model of the place where traffic flows are simulated, even in these professional software tools it is a hard and time consuming action. The goal of this paper is to describe the concepts of use the existing on-line geographical information systems for visualisation of animation produced by simulation software. For demonstration purposes the following technologies and tools have been used: PTV VISION VISSIM, KML and Google Earth.

  11. Towards a Microscopic Reaction Description Based on Energy Density Functionals

    SciTech Connect

    Nobre, G A; DIetrich, F S; Escher, J E; Thompson, I J; Dupuis, M; Terasaki, J; Engel, J

    2011-09-26

    A microscopic calculation of reaction cross sections for nucleon-nucleus scattering has been performed by explicitly coupling the elastic channel to all particle-hole excitations in the target and one-nucleon pickup channels. The particle-hole states may be regarded as doorway states through which the flux flows to more complicated configurations, and subsequently to long-lived compound nucleus resonances. Target excitations for {sup 40,48}Ca, {sup 58}Ni, {sup 90}Zr and {sup 144}Sm were described in a random-phase framework using a Skyrme functional. Reaction cross sections obtained agree very well with experimental data and predictions of a state-of-the-art fitted optical potential. Couplings between inelastic states were found to be negligible, while the pickup channels contribute significantly. The effect of resonances from higher-order channels was assessed. Elastic angular distributions were also calculated within the same method, achieving good agreement with experimental data. For the first time observed absorptions are completely accounted for by explicit channel coupling, for incident energies between 10 and 70 MeV, with consistent angular distribution results.

  12. Space-based infrared surveys of small bodies

    NASA Astrophysics Data System (ADS)

    Mommert, M.

    2014-07-01

    Most small bodies in the Solar System are too small and too distant to be spatially resolved, precluding a direct diameter derivation. Furthermore, measurements of the optical brightness alone only allow a rough estimate of the diameter, since the surface albedo is usually unknown and can have values between about 3 % and 60 % or more. The degeneracy can be resolved by considering the thermal emission of these objects, which is less prone to albedo effects and mainly a function of the diameter. Hence, the combination of optical and thermal-infrared observational data provides a means to independently derive an object's diameter and albedo. This technique is used in asteroid thermal models or more sophisticated thermophysical models (see, e.g., [1]). Infrared observations require cryogenic detectors and/or telescopes, depending on the actual wavelength range observed. Observations from the ground are additionally compromised by the variable transparency of Earth's atmosphere in major portions of the infrared wavelength ranges. Hence, space-based infrared telescopes, providing stable conditions and significantly better sensitivities than ground-based telescopes, are now used routinely to exploit this wavelength range. Two observation strategies are used with space-based infrared observatories: Space-based Infrared All-Sky Surveys. Asteroid surveys in the thermal infrared are less prone to albedo-related discovery bias compared to surveys with optical telescopes, providing a more complete picture of small body populations. The first space-based infrared survey of Solar System small bodies was performed with the Infrared Astronomical Satellite (IRAS) for 10 months in 1983. In the course of the 'IRAS Minor Planet Survey' [2], 2228 asteroids (3 new discoveries) and more than 25 comets (6 new discoveries) were observed. More recent space-based infrared all-sky asteroid surveys were performed by Akari (launched 2006) and the Wide-field Infrared Survey Explorer (WISE

  13. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  14. Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

    SciTech Connect

    Qiu, Weicheng; Hu, Weida Lin, Tie; Yin, Fei; Zhang, Bo; Chen, Xiaoshuang; Lu, Wei; Cheng, Xiang'ai Wang, Rui

    2014-11-10

    In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixed conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.

  15. Inquiry-based Science Activities Using The Infrared Zoo and Infrared Yellowstone Resources at Cool Cosmos

    NASA Astrophysics Data System (ADS)

    Daou, D.; Gauthier, A.

    2003-12-01

    Inquiry-based activities that utilize the Cool Cosmos image galleries have been designed and developed by K12 teachers enrolled in The Invisible Universe Online for Teachers course. The exploration activities integrate the Our Infrared World Gallery (http://coolcosmos.ipac.caltech.edu/image_galleries/our_ir_world_gallery.html) with either the Infrared Zoo gallery (http://coolcosmos.ipac.caltech.edu/image_galleries/ir_zoo/index.html) or the Infrared Yellowstone image http://coolcosmos.ipac.caltech.edu/image_galleries/ir_yellowstone/index.html) and video (http://coolcosmos.ipac.caltech.edu/videos/ir_yellowstone/index.html) galleries. Complete instructor guides have been developed for the activities and will be presented by the authors in poster and CD form. Although the activities are written for middle and highschool learners, they can easily be adapted for college audiences. The Our Infrared World Gallery exploration helps learners think critically about visible light and infrared light as they compare sets of images (IR and visible light) of known objects. For example: by taking a regular photograph of a running faucet, can you tell if it is running hot or cold water? What new information does the IR image give you? The Infrared Zoo activities encourage learners to investigate the differences between warm and cold blooded animals by comparing sets of IR and visible images. In one activity, learners take on the role of a pit viper seeking prey in various desert and woodland settings. The main activities are extended into the real world by discussing and researching industrial, medical, and societal applications of infrared technologies. The Infrared Yellowstone lessons give learners a unique perspective on Yellowstone National Park and it's spectacular geologic and geothermal features. Infrared video technology is highlighted as learners make detailed observations about the visible and infrared views of the natural phenomena. The "Cool Cosmos" EPO activities are

  16. Measurement of borneol based on infrared spectrometry

    NASA Astrophysics Data System (ADS)

    Gu, Xiaoyu; Wang, Yan; Sun, Huili; Xu, Kexin

    2005-02-01

    The infrared spectrometry contains multiple information of the sample, and it is easy to be applied to on-line measurement. To Chinese medicine, this technology can improve the standard of quality control and accelerate the modernization course. In this paper, we investigate the spectral characteristics of borneol, an effective ingredient in many Chinese medicines. The following results are achieved. In middle infrared (MIR) region, utilizing the linear relationship between absorption and concentration, the concentration of borneol with relative error within 4.30% in the strongest absorption region (2950-2970 cm(-1)) is measured; in near infrared (NIR) region, the predicted concentrations of borneol are calculated by using partial least squares (PLS) regression analysis, in which the wavelengths are selected by genetic algorithm (GA) from the absorption bands of borneol in NIR region. The predicted relative error of calibration model is less than 2%. This result shows that PLS regression analysis combining genetic algorithm is a good method to improve prediction and reduce data in NIR region.

  17. Model based control of dynamic atomic force microscope

    SciTech Connect

    Lee, Chibum; Salapaka, Srinivasa M.

    2015-04-15

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H{sub ∞} control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments.

  18. Model based control of dynamic atomic force microscope.

    PubMed

    Lee, Chibum; Salapaka, Srinivasa M

    2015-04-01

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H(∞) control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments.

  19. A background suppression algorithm for infrared image based on shearlet

    NASA Astrophysics Data System (ADS)

    Zou, Ruibin; Shi, Caicheng; Qin, Xiao

    2015-04-01

    Because of the relative far distance between infrared imaging system and target or the wide field infrared optical, the imaging area of infrared target is only a few pixels, which is isolated or spots to be showed in the field of view. The only available is the intensity information (gray value) for the target detection. Simultaneously, there are many shortcomings of the infrared image, such as large noise, interference and so on, therefore the small target is always buried in the background and noises. The small target is relatively difficult to detect, so generally, it is impossible to make reliable detection to this target in a single frame image. Summarily, the core of the infrared small target detection algorithm is the background and noise suppression based on a single frame image. Aiming at the infrared small target detection and the above problems, a shearlets-based background suppression algorithm for infrared image is proposed. The algorithm demonstrates the performance of advantage based on shearlets, which is especially designed to address anisotropic and directional information at various scales. This transform provides an optimally efficient representation of images, which is greatly reduced the amount of the information and the available information representation. In the paper, introducing the principle of shearlets first, and then proposing the theory of the algorithm and explaining the implementation step. Finally, giving the simulation results. In Matlab simulations with this method for several sets of infrared images, simulation results conformed to the theory on background suppression based on shearlets. The result showed that this method can effectively suppress background, and improve the SCR and achieve a satisfactory effect in the sky background. The method is very effectively for target detection, identification, track in infrared image system for the future.

  20. Determination of the sequence of intersecting lines from laser toner and seal ink by Fourier transform infrared microspectroscopy and scanning electron microscope / energy dispersive X-ray mapping.

    PubMed

    Wang, Yuanfeng; Li, Bing

    2012-06-01

    The aim of this study was to verify that the combination of Fourier transform infrared microspectroscopy and scanning electron microscope / energy dispersive X-ray mapping could be applied to line intersection problems. The spectral data of red seal ink, laser toner and their intersections, such as peak location and peak intensity, were described. Relative peak height ratios of different chemical components in intersecting lines were used to distinguish the sequences. Energy dispersive X-ray mapping characteristics of intersecting areas were also detailed. The results show that both the laser toner and the seal ink appear on the surface of intersections, regardless of the sequence. The distribution of the two inks on the surface is influenced not only by the sequence of heterogeneous lines but also by diffusion. Fourier transform infrared microspectroscopy and scanning electron microscope/energy dispersive X-ray mapping are able to explore the chemical components and the corresponding elemental distribution in the intersections. The combination of these two techniques has provided a reliable method for sequencing intersecting lines of red seal ink and laser toner, and more importantly, this method may be a basis for sequencing superimposed lines from other writing instruments.

  1. Microscopic Approach to Species Coexistence Based on Evolutionary Game Dynamics

    NASA Astrophysics Data System (ADS)

    Grebogi, Celso; Lai, Ying-Cheng; Wang, Wen-Xu

    2014-12-01

    An outstanding problem in complex systems and mathematical biology is to explore and understand the fundamental mechanisms of species coexistence. Existing approaches are based on niche partitioning, dispersal, chaotic evolutionary dynamics, and more recently, evolutionary games. Here we briefly review a number of fundamental issues associated with the coexistence of mobile species under cyclic competitions in the framework of evolutionary games.

  2. Artificial tribotactic microscopic walkers: walking based on friction gradients.

    PubMed

    Steimel, Joshua P; Aragones, Juan L; Alexander-Katz, Alfredo

    2014-10-24

    Friction, the resistive force between two surfaces sliding past each other, is at the core of a wide diversity of locomotion schemes. While such schemes are well described for homogeneous environments, locomotion based on friction in inhomogeneous environments has not received much attention. Here we introduce and demonstrate the concept of tribotaxis, a motion that is guided by gradients in the friction coefficient. Our system is composed of microwalkers that undergo an effective frictional interaction with biological receptors on the substrate, which is regulated by the density of such receptors. When actuated stochastically, microwalkers migrate to regions of higher friction, much like a chemotactic cell migrates to regions of higher chemoattractant concentration. Simulations and theory based on biased random walks are in excellent agreement with experiments. We foresee important implications for tribotaxis in artificial and natural locomotion in biological environments.

  3. Reproducing kernel hilbert space based single infrared image super resolution

    NASA Astrophysics Data System (ADS)

    Chen, Liangliang; Deng, Liangjian; Shen, Wei; Xi, Ning; Zhou, Zhanxin; Song, Bo; Yang, Yongliang; Cheng, Yu; Dong, Lixin

    2016-07-01

    The spatial resolution of Infrared (IR) images is limited by lens optical diffraction, sensor array pitch size and pixel dimension. In this work, a robust model is proposed to reconstruct high resolution infrared image via a single low resolution sampling, where the image features are discussed and classified as reflective, cooled emissive and uncooled emissive based on infrared irradiation source. A spline based reproducing kernel hilbert space and approximative heaviside function are deployed to model smooth part and edge component of image respectively. By adjusting the parameters of heaviside function, the proposed model can enhance distinct part of images. The experimental results show that the model is applicable on both reflective and emissive low resolution infrared images to improve thermal contrast. The overall outcome produces a high resolution IR image, which makes IR camera better measurement accuracy and observes more details at long distance.

  4. Design of integration-ready metasurface-based infrared absorbers

    SciTech Connect

    Ogando, Karim Pastoriza, Hernán

    2015-07-28

    We introduce an integration ready design of metamaterial infrared absorber, highly compatible with many kinds of fabrication processes. We present the results of an exhaustive experimental characterization, including an analysis of the effects of single meta-atom geometrical parameters and collective arrangement. We confront the results with the theoretical interpretations proposed in the literature. Based on the results, we develop a set of practical design rules for metamaterial absorbers in the infrared region.

  5. Based on spatial-temporal multiframe association infrared target detection

    NASA Astrophysics Data System (ADS)

    Wang, Zhonghua; Wang, Chao; Huang, Faliang; Liu, Jianguo

    2015-12-01

    Infrared small target detection is difficult due to several aspects, including the low signal-to-clutter ratio of the infrared image, and the small size, lack of shape and texture information of the target. a novel method, which is based on spatial-temporal association, is presented for infrared target detection. The algorithm consists of the three steps: Firstly, 2-dimensional histogram of entropy flow field is computed to estimate the background motion. Secondly, the difference image through background motion compensation is obtained. Finally, the targets are detected by spatial-temporal filter. The experiment results demonstrate that the proposed algorithm is robust to noise, and also fit to detect small targets under moving backgrounds in infrared image sequences.

  6. Mercury arc lamp based super-resolution imaging with conventional fluorescence microscopes.

    PubMed

    Yuan, Zhiwei; Sun, Jielin; Zhai, Renkuan; Li, Xiaowei; Shao, Zhifeng

    2014-04-01

    We present an implementation of localization based three-dimensional super-resolution imaging on a regular microscope. We retain the original arc lamp as the photoactivation light source, and incorporate an inexpensive diode laser for imaging. As alterations to the standard microscope is minimal, this optical setup can be easily adapted in a typical research laboratory and even undergraduate teaching experiments, providing an inexpensive system for students and research scientists who require such super resolution capabilities. With this simple design, a spatial resolution of better than 40 nm at a reasonable frame rate has been achieved, adequate for most routine applications.

  7. An Introduction to Differentials Based on Hyperreal Numbers and Infinite Microscopes

    ERIC Educational Resources Information Center

    Henry, Valerie

    2010-01-01

    In this article, we propose to introduce the differential of a function through a non-classical way, lying on hyperreals and infinite microscopes. This approach is based on the developments of nonstandard analysis, wants to be more intuitive than the classical one and tries to emphasize the functional and geometric aspects of the differential. In…

  8. Microscope-Based Fluid Physics Experiments in the Fluids and Combustion Facility on ISS

    NASA Technical Reports Server (NTRS)

    Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Malarik, Diane C.

    2000-01-01

    At the NASA Glenn Research Center, the Microgravity Science Program is planning to conduct a large number of experiments on the International Space Station in both the Fluid Physics and Combustion Science disciplines, and is developing flight experiment hardware for use within the International Space Station's Fluids and Combustion Facility. Four fluids physics experiments that require an optical microscope will be sequentially conducted within a subrack payload to the Fluids Integrated Rack of the Fluids and Combustion Facility called the Light Microscopy Module, which will provide the containment, changeout, and diagnostic capabilities to perform the experiments. The Light Microscopy Module is planned as a fully remotely controllable on-orbit microscope facility, allowing flexible scheduling and control of experiments within International Space Station resources. This paper will focus on the four microscope-based experiments, specifically, their objectives and the sample cell and instrument hardware to accommodate their requirements.

  9. Land-based infrared imagery for marine mammal detection

    NASA Astrophysics Data System (ADS)

    Graber, Joseph; Thomson, Jim; Polagye, Brian; Jessup, Andrew

    2011-09-01

    A land-based infrared (IR) camera is used to detect endangered Southern Resident killer whales in Puget Sound, Washington, USA. The observations are motivated by a proposed tidal energy pilot project, which will be required to monitor for environmental effects. Potential monitoring methods also include visual observation, passive acoustics, and active acoustics. The effectiveness of observations in the infrared spectrum is compared to observations in the visible spectrum to assess the viability of infrared imagery for cetacean detection and classification. Imagery was obtained at Lime Kiln Park, Washington from 7/6/10-7/9/10 using a FLIR Thermovision A40M infrared camera (7.5-14μm, 37°HFOV, 320x240 pixels) under ideal atmospheric conditions (clear skies, calm seas, and wind speed 0-4 m/s). Whales were detected during both day (9 detections) and night (75 detections) at distances ranging from 42 to 162 m. The temperature contrast between dorsal fins and the sea surface ranged from 0.5 to 4.6 °C. Differences in emissivity from sea surface to dorsal fin are shown to aid detection at high incidence angles (near grazing). A comparison to theory is presented, and observed deviations from theory are investigated. A guide for infrared camera selection based on site geometry and desired target size is presented, with specific considerations regarding marine mammal detection. Atmospheric conditions required to use visible and infrared cameras for marine mammal detection are established and compared with 2008 meteorological data for the proposed tidal energy site. Using conservative assumptions, infrared observations are predicted to provide a 74% increase in hours of possible detection, compared with visual observations.

  10. Defects' geometric feature recognition based on infrared image edge detection

    NASA Astrophysics Data System (ADS)

    Junyan, Liu; Qingju, Tang; Yang, Wang; Yumei, Lu; Zhiping, Zhang

    2014-11-01

    Edge detection is an important technology in image segmentation, feature extraction and other digital image processing areas. Boundary contains a wealth of information in the image, so to extract defects' edges in infrared images effectively enables the identification of defects' geometric features. This paper analyzed the detection effect of classic edge detection operators, and proposed fuzzy C-means (FCM) clustering-Canny operator algorithm to achieve defects' edges in the infrared images. Results show that the proposed algorithm has better effect than the classic edge detection operators, which can identify the defects' geometric feature much more completely and clearly. The defects' diameters have been calculated based on the image edge detection results.

  11. Application of local gene induction by infrared laser-mediated microscope and temperature stimulator to amphibian regeneration study.

    PubMed

    Kawasumi-Kita, Aiko; Hayashi, Toshinori; Kobayashi, Takuya; Nagayama, Chikashi; Hayashi, Shinichi; Kamei, Yasuhiro; Morishita, Yoshihiro; Takeuchi, Takashi; Tamura, Koji; Yokoyama, Hitoshi

    2015-12-01

    Urodele amphibians (newts and salamanders) and anuran amphibians (frogs) are excellent research models to reveal mechanisms of three-dimensional organ regeneration since they have exceptionally high regenerative capacity among tetrapods. However, the difficulty in manipulating gene expression in cells in a spatially restricted manner has so far hindered elucidation of the molecular mechanisms of organ regeneration in amphibians. Recently, local heat shock by laser irradiation has enabled local gene induction even at the single-cell level in teleost fishes, nematodes, fruit flies and plants. In this study, local heat shock was made with infrared laser irradiation (IR-LEGO) by using a gene expression inducible system in transgenic animals containing a heat shock promoter, and gene expression was successfully induced only in the target region of two amphibian species, Xenopus laevis and Pleurodeles waltl (a newt), at postembryonic stages. Furthermore, we induced spatially restricted but wider gene expression in Xenopus laevis tadpoles and froglets by applying local heat shock by a temperature-controlled metal probe (temperature stimulator). The local gene manipulation systems, the IR-LEGO and the temperature stimulator, enable us to do a rigorous cell lineage trace with the combination of the Cre-LoxP system as well as to analyze gene function in a target region or cells with less off-target effects in the study of amphibian regeneration.

  12. Application of local gene induction by infrared laser-mediated microscope and temperature stimulator to amphibian regeneration study.

    PubMed

    Kawasumi-Kita, Aiko; Hayashi, Toshinori; Kobayashi, Takuya; Nagayama, Chikashi; Hayashi, Shinichi; Kamei, Yasuhiro; Morishita, Yoshihiro; Takeuchi, Takashi; Tamura, Koji; Yokoyama, Hitoshi

    2015-12-01

    Urodele amphibians (newts and salamanders) and anuran amphibians (frogs) are excellent research models to reveal mechanisms of three-dimensional organ regeneration since they have exceptionally high regenerative capacity among tetrapods. However, the difficulty in manipulating gene expression in cells in a spatially restricted manner has so far hindered elucidation of the molecular mechanisms of organ regeneration in amphibians. Recently, local heat shock by laser irradiation has enabled local gene induction even at the single-cell level in teleost fishes, nematodes, fruit flies and plants. In this study, local heat shock was made with infrared laser irradiation (IR-LEGO) by using a gene expression inducible system in transgenic animals containing a heat shock promoter, and gene expression was successfully induced only in the target region of two amphibian species, Xenopus laevis and Pleurodeles waltl (a newt), at postembryonic stages. Furthermore, we induced spatially restricted but wider gene expression in Xenopus laevis tadpoles and froglets by applying local heat shock by a temperature-controlled metal probe (temperature stimulator). The local gene manipulation systems, the IR-LEGO and the temperature stimulator, enable us to do a rigorous cell lineage trace with the combination of the Cre-LoxP system as well as to analyze gene function in a target region or cells with less off-target effects in the study of amphibian regeneration. PMID:26510480

  13. Scene classification of infrared images based on texture feature

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Bai, Tingzhu; Shang, Fei

    2008-12-01

    Scene Classification refers to as assigning a physical scene into one of a set of predefined categories. Utilizing the method texture feature is good for providing the approach to classify scenes. Texture can be considered to be repeating patterns of local variation of pixel intensities. And texture analysis is important in many applications of computer image analysis for classification or segmentation of images based on local spatial variations of intensity. Texture describes the structural information of images, so it provides another data to classify comparing to the spectrum. Now, infrared thermal imagers are used in different kinds of fields. Since infrared images of the objects reflect their own thermal radiation, there are some shortcomings of infrared images: the poor contrast between the objectives and background, the effects of blurs edges, much noise and so on. Because of these shortcomings, it is difficult to extract to the texture feature of infrared images. In this paper we have developed an infrared image texture feature-based algorithm to classify scenes of infrared images. This paper researches texture extraction using Gabor wavelet transform. The transformation of Gabor has excellent capability in analysis the frequency and direction of the partial district. Gabor wavelets is chosen for its biological relevance and technical properties In the first place, after introducing the Gabor wavelet transform and the texture analysis methods, the infrared images are extracted texture feature by Gabor wavelet transform. It is utilized the multi-scale property of Gabor filter. In the second place, we take multi-dimensional means and standard deviation with different scales and directions as texture parameters. The last stage is classification of scene texture parameters with least squares support vector machine (LS-SVM) algorithm. SVM is based on the principle of structural risk minimization (SRM). Compared with SVM, LS-SVM has overcome the shortcoming of

  14. Microscopic silicon-based lateral high-aspect-ratio structures for thin film conformality analysis

    SciTech Connect

    Gao, Feng; Arpiainen, Sanna; Puurunen, Riikka L.

    2015-01-15

    Film conformality is one of the major drivers for the interest in atomic layer deposition (ALD) processes. This work presents new silicon-based microscopic lateral high-aspect-ratio (LHAR) test structures for the analysis of the conformality of thin films deposited by ALD and by other chemical vapor deposition means. The microscopic LHAR structures consist of a lateral cavity inside silicon with a roof supported by pillars. The cavity length (e.g., 20–5000 μm) and cavity height (e.g., 200–1000 nm) can be varied, giving aspect ratios of, e.g., 20:1 to 25 000:1. Film conformality can be analyzed with the microscopic LHAR by several means, as demonstrated for the ALD Al{sub 2}O{sub 3} and TiO{sub 2} processes from Me{sub 3}Al/H{sub 2}O and TiCl{sub 4}/H{sub 2}O. The microscopic LHAR test structures introduced in this work expose a new parameter space for thin film conformality investigations expected to prove useful in the development, tuning and modeling of ALD and other chemical vapor deposition processes.

  15. Dual-mode optical microscope based on single-pixel imaging

    NASA Astrophysics Data System (ADS)

    Rodríguez, A. D.; Clemente, P.; Tajahuerce, E.; Lancis, J.

    2016-07-01

    We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.

  16. Identification of seven Zingiberaceous species based on comparative anatomy of microscopic characteristics of seeds

    PubMed Central

    2014-01-01

    Background The fruits and seeds of Alpinia galanga (L.) Willd., Alpinia katsumadai Hayata, Alpinia zerumbet (Pers.) Burtt. & Smith, Amomum kravanh Pierre ex Gagnep., Amomum subulatum Roxb., Amomum tsao-ko Crevost et Lemaire, and Elettaria cardamomum (L.) Maton from Alpinia, Amomum, and Elettaria genera in the Zingiberaceae family are difficult to distinguish between each other. This study aims to identify the seeds of these seven species from Zingiberaceae family based on comparative anatomy of microscopic characteristics. Methods We compared the morphological structures of seed coats by observing the microscopic characteristics of seeds in transverse sections. We described the macroscopic characteristics of seeds in detail. Results The seeds of these three genera could not be identified to the species level based on their macroscopic features. However, based on the anatomical features of the seed coat observed in transverse sections, a dichotomous key for these seven species was feasible. Conclusion Seven species in the Zingiberaceae family could be identified based on comparative anatomy of microscopic characteristics of transverse section of seed. PMID:24607026

  17. Infrared imaging using carbon nanotube-based detector

    NASA Astrophysics Data System (ADS)

    Chen, Hongzhi; Xi, Ning; Song, Bo; Chen, Liangliang; Lai, King W. C.; Lou, Jianyong

    2011-06-01

    Using carbon nanotubes (CNT), high performance infrared detectors have been developed. Since the CNTs have extraordinary optoelectronics properties due to its unique one dimensional geometry and structure, the CNT based infrared detectors have extremely low dark current, low noise equivalent temperature difference (NETD), short response time, and high dynamic range. Most importantly, it can detect 3-5 um middle-wave infrared (MWIR) at room temperature. This unique feature can significantly reduce the size and weight of a MWIR imaging system by eliminating a cryogenic cooling system. However, there are two major difficulties that impede the application of CNT based IR detectors for imaging systems. First, the small diameter of the CNTs results in low fill factor. Secondly, it is difficult to fabricate large scale of detector array for high resolution focal plane due to the limitations on the efficiency and cost of the manufacturing. In this paper, a new CNT based IR imaging system will be presented. Integrating the CNT detectors with photonic crystal resonant cavity, the fill factor of the CNT based IR sensor can reach as high as 0.91. Furthermore, using the compressive sensing technology, a high resolution imaging can be achieved by CNT based IR detectors. The experimental testing results show that the new imaging system can achieve the superb performance enabled by CNT based IR detectors, and, at the same time, overcame its difficulties to achieve high resolution and efficient imaging.

  18. Long-wave infrared polarimetric cluster-based vehicle detection.

    PubMed

    Dickson, Christopher N; Wallace, Andrew M; Kitchin, Matthew; Connor, Barry

    2015-12-01

    The sensory perception of other vehicles in cluttered environments is an essential component of situational awareness for a mobile vehicle. However, vehicle detection is normally applied to visible imagery sequences, while in this paper we investigate how polarized, infrared imagery can add additional discriminatory power. Using knowledge about the properties of the objects of interest and the scene environment, we have developed a polarimetric cluster-based descriptor to detect vehicles using long-wave infrared radiation in the range of 8-12 μm. Our approach outperforms both intensity and polarimetric image histogram descriptors applied to the infrared data. For example, at a false positive rate of 0.01 per detection window, our cluster approach results in a true positive rate of 0.63 compared to a rate of 0.05 for a histogram of gradient descriptor trained and tested on the same dataset. In conclusion, we discuss the potential of this new approach in comparison with state-of-the-art infrared and conventional video detection. PMID:26831384

  19. Automated cervical precancerous cells screening system based on Fourier transform infrared spectroscopy features

    NASA Astrophysics Data System (ADS)

    Jusman, Yessi; Mat Isa, Nor Ashidi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Abu Osman, Noor Azuan

    2016-07-01

    Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical cell that occurs before the morphological change could be observed under the light microscope as employed in conventional techniques. This paper presents developed features extraction for an automated screening system for cervical precancerous cell based on the FTIR spectroscopy as a second opinion to pathologists. The automated system generally consists of the developed features extraction and classification stages. Signal processing techniques are used in the features extraction stage. Then, discriminant analysis and principal component analysis are employed to select dominant features for the classification process. The datasets of the cervical precancerous cells obtained from the feature selection process are classified using a hybrid multilayered perceptron network. The proposed system achieved 92% accuracy.

  20. Comparative study on submillimeter flaws in stitched T-joint carbon fiber reinforced polymer by infrared thermography, microcomputed tomography, ultrasonic c-scan and microscopic inspection

    NASA Astrophysics Data System (ADS)

    Zhang, Hai; Hassler, Ulf; Genest, Marc; Fernandes, Henrique; Robitaille, Francois; Ibarra-Castanedo, Clemente; Joncas, Simon; Maldague, Xavier

    2015-10-01

    Stitching is used to reduce dry-core (incomplete infusion of T-joint core) and reinforce T-joint structure. However, it may cause new types of flaws, especially submillimeter flaws. Microscopic inspection, ultrasonic c-scan, pulsed thermography, vibrothermography, and laser spot thermography are used to investigate the internal flaws in a stitched T-joint carbon fiber-reinforced polymer (CFRP) matrix composites. Then, a new microlaser line thermography is proposed. Microcomputed tomography (microCT) is used to validate the infrared results. A comparison between microlaser line thermography and microCT is performed. It was concluded that microlaser line thermography can detect the internal submillimeter defects. However, the depth and size of the defects can affect the detection results. The microporosities with a diameter of less than 54 μm are not detected in the microlaser line thermography results. Microlaser line thermography can detect the microporosity (a diameter of 0.162 mm) from a depth of 90 μm. However, it cannot detect the internal microporosity (a diameter of 0.216 mm) from a depth of 0.18 mm. The potential causes are given. Finally, a comparative study is conducted.

  1. Dark current in antimony-based mid-infrared interband cascade infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Tian, Z.-B.; Schuler-Sandy, T.; Krishna, S.

    2015-05-01

    The quantum-engineered interband cascade (IC) photodetector is a new type of infrared detectors with many unique and highly desirable features. The multi-stage design allows much flexibility in device optimization for different application environment, such as operation temperature, irradiance level, and possibly high-speed and fast frame-rate application scenarios. Many other distinctive features, such as excellent photo-carrier extraction and photovoltaic (zero-bias) operations, are also very attractive for high performance infrared imaging applications. In this paper, we report our experimental investigation on the dark current mechanisms in mid-wave infrared (MWIR) InAs/GaSb type-II superlattices based IC photodetectors. The electrical performance of MWIR IC detectors with several different designs are presented in detail. The dark current density in the MWIR IC detectors is as low as 4.26 × 10-8 A/cm2 (1.44 × 10-3 A/cm2) at -10 mV, with Johnson-limited D∗ of 9.11 × 1011 cm Hz1/2/W (1.58 × 109 cm Hz1/2/W) at 140 K (room temperature) and 3.6 μm. Our results indicate that the dominating dark current in IC detectors is from tunneling components at lower temperatures, and changes to diffusion current at higher operating temperatures. Furthermore, our effort also shows that the dark current performance in IC devices can be improved substantially by refining the device design and implementations.

  2. Plasmons in molecules: Microscopic characterization based on orbital transitions and momentum conservation

    NASA Astrophysics Data System (ADS)

    Krauter, Caroline M.; Schirmer, Jochen; Jacob, Christoph R.; Pernpointner, Markus; Dreuw, Andreas

    2014-09-01

    In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator.

  3. Plasmons in molecules: microscopic characterization based on orbital transitions and momentum conservation.

    PubMed

    Krauter, Caroline M; Schirmer, Jochen; Jacob, Christoph R; Pernpointner, Markus; Dreuw, Andreas

    2014-09-14

    In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator.

  4. Plasmons in molecules: Microscopic characterization based on orbital transitions and momentum conservation

    SciTech Connect

    Krauter, Caroline M.; Schirmer, Jochen; Pernpointner, Markus; Jacob, Christoph R.; Dreuw, Andreas

    2014-09-14

    In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator.

  5. eSIP: A Novel Solution-Based Sectioned Image Property Approach for Microscope Calibration

    PubMed Central

    Butzlaff, Malte; Weigel, Arwed; Ponimaskin, Evgeni; Zeug, Andre

    2015-01-01

    Fluorescence confocal microscopy represents one of the central tools in modern sciences. Correspondingly, a growing amount of research relies on the development of novel microscopic methods. During the last decade numerous microscopic approaches were developed for the investigation of various scientific questions. Thereby, the former qualitative imaging methods became replaced by advanced quantitative methods to gain more and more information from a given sample. However, modern microscope systems being as complex as they are, require very precise and appropriate calibration routines, in particular when quantitative measurements should be compared over longer time scales or between different setups. Multispectral beads with sub-resolution size are often used to describe the point spread function and thus the optical properties of the microscope. More recently, a fluorescent layer was utilized to describe the axial profile for each pixel, which allows a spatially resolved characterization. However, fabrication of a thin fluorescent layer with matching refractive index is technically not solved yet. Therefore, we propose a novel type of calibration concept for sectioned image property (SIP) measurements which is based on fluorescent solution and makes the calibration concept available for a broader number of users. Compared to the previous approach, additional information can be obtained by application of this extended SIP chart approach, including penetration depth, detected number of photons, and illumination profile shape. Furthermore, due to the fit of the complete profile, our method is less susceptible to noise. Generally, the extended SIP approach represents a simple and highly reproducible method, allowing setup independent calibration and alignment procedures, which is mandatory for advanced quantitative microscopy. PMID:26244982

  6. eSIP: A Novel Solution-Based Sectioned Image Property Approach for Microscope Calibration.

    PubMed

    Butzlaff, Malte; Weigel, Arwed; Ponimaskin, Evgeni; Zeug, Andre

    2015-01-01

    Fluorescence confocal microscopy represents one of the central tools in modern sciences. Correspondingly, a growing amount of research relies on the development of novel microscopic methods. During the last decade numerous microscopic approaches were developed for the investigation of various scientific questions. Thereby, the former qualitative imaging methods became replaced by advanced quantitative methods to gain more and more information from a given sample. However, modern microscope systems being as complex as they are, require very precise and appropriate calibration routines, in particular when quantitative measurements should be compared over longer time scales or between different setups. Multispectral beads with sub-resolution size are often used to describe the point spread function and thus the optical properties of the microscope. More recently, a fluorescent layer was utilized to describe the axial profile for each pixel, which allows a spatially resolved characterization. However, fabrication of a thin fluorescent layer with matching refractive index is technically not solved yet. Therefore, we propose a novel type of calibration concept for sectioned image property (SIP) measurements which is based on fluorescent solution and makes the calibration concept available for a broader number of users. Compared to the previous approach, additional information can be obtained by application of this extended SIP chart approach, including penetration depth, detected number of photons, and illumination profile shape. Furthermore, due to the fit of the complete profile, our method is less susceptible to noise. Generally, the extended SIP approach represents a simple and highly reproducible method, allowing setup independent calibration and alignment procedures, which is mandatory for advanced quantitative microscopy. PMID:26244982

  7. Infrared transparent frequency selective surface based on metallic meshes

    SciTech Connect

    Yu, Miao; Xu, Nianxi; Liu, Hai; Gao, Jinsong

    2014-02-15

    This paper presents an infrared transparent frequency selective surface (ITFSS) based on metallic meshes. In this ITFSS structure, periodic cross-slot units are integrated on square metallic meshes empowered by coating and UV-lithography. A matching condition is proposed to avoid the distortion of units. Experimental results show that this ITFSS possesses a good transmittance of 80% in the infrared band of 3–5 μm, and also a stable band-pass behavior at the resonance frequency of 36.4 GHz with transmittance of −0.56 dB. Theoretical simulations about the ITFSS diffractive characteristics and frequency responses are also investigated. The novel ITFSS will attract renewed interest and be exploited for applications in various fields.

  8. Infrared sensor-based temperature control for domestic induction cooktops.

    PubMed

    Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

    2014-01-01

    In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented. PMID:24638125

  9. Infrared sensor-based temperature control for domestic induction cooktops.

    PubMed

    Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

    2014-03-14

    In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented.

  10. Infrared Sensor-Based Temperature Control for Domestic Induction Cooktops

    PubMed Central

    Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

    2014-01-01

    In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented. PMID:24638125

  11. Scene-based nonuniformity correction in infrared videos

    NASA Astrophysics Data System (ADS)

    Bae, Yoonsung; Lee, Jongho; Lee, Jong Ho; Ra, Jong Beom

    2012-05-01

    Recent infrared (IR) sensors are mostly based on a focal-plane array (FPA) structure. However, IR images suffer from the fixed pattern noise (FPN) due to non-uniform response of a FPA structure. Various nonuniformity correction (NUC) techniques have been developed to alleviate the FPN. They can be categorized into reference-based and scene-based approaches. In order to deal with a temporal drift, however, a scene-based approach is needed. Among scene-based algorithms, conventional algorithms compensate only for the offset non-uniformity of IR camera detectors based on the global motion information. Local motions in a video, however, can introduce inaccurate motion information for NUC. Considering global and local motions simultaneously, we propose a correction algorithm of gain and offset. Experiment results using simulated and real IR videos show that the proposed algorithm provides performance improvement on the FPN reduction.

  12. The Pocketscope: a spatial light modulator based epi-fluorescence microscope for optogenetics

    NASA Astrophysics Data System (ADS)

    Linnenberger, Anna; Peterka, Darcy S.; Quirin, Sean; Yuste, Rafael

    2014-09-01

    Microscopy incorporating spatial light modulators (SLMs) enables three dimensional (3D) excitation and monitoring of the activity of neuronal ensembles, enabling studies of neuronal circuit activity both in vitro and in vivo. In this paper we present a portable (22 cm x 42.5 cm x 30 cm), SLM-based epi-fluorescence upright microscope ("Pocketscope") that enables 3D calcium imaging and photoactivation of neurons in brain slices. Here we describe the implementation of the instrument; quantify the volume over which neural activity can be excited; and demonstrate the use of the system for mapping neural circuits in brain slices.

  13. Texture orientation-based algorithm for detecting infrared maritime targets.

    PubMed

    Wang, Bin; Dong, Lili; Zhao, Ming; Wu, Houde; Xu, Wenhai

    2015-05-20

    Infrared maritime target detection is a key technology for maritime target searching systems. However, in infrared maritime images (IMIs) taken under complicated sea conditions, background clutters, such as ocean waves, clouds or sea fog, usually have high intensity that can easily overwhelm the brightness of real targets, which is difficult for traditional target detection algorithms to deal with. To mitigate this problem, this paper proposes a novel target detection algorithm based on texture orientation. This algorithm first extracts suspected targets by analyzing the intersubband correlation between horizontal and vertical wavelet subbands of the original IMI on the first scale. Then the self-adaptive wavelet threshold denoising and local singularity analysis of the original IMI is combined to remove false alarms further. Experiments show that compared with traditional algorithms, this algorithm can suppress background clutter much better and realize better single-frame detection for infrared maritime targets. Besides, in order to guarantee accurate target extraction further, the pipeline-filtering algorithm is adopted to eliminate residual false alarms. The high practical value and applicability of this proposed strategy is backed strongly by experimental data acquired under different environmental conditions.

  14. Gas cloud infrared image enhancement based on anisotropic diffusion

    NASA Astrophysics Data System (ADS)

    Li, Jiakun; Wang, Lingxue; Zhang, Changxing; Long, Yunting; Zhang, Bei

    2011-05-01

    Leakage of dangerous gases will not only pollute the environment, but also seriously threat public safety. Thermal infrared imaging has been proved to be an efficient method to qualitatively detect the gas leakage. But some problems are remained, especially when monitoring the leakage in a passive way. For example, the signal is weak and the edge of gas cloud in the infrared image is not obvious enough. However, we notice some important characteristics of the gas plume and therefore propose a gas cloud infrared image enhancement method based on anisotropic diffusion. As the gas plume presents a large gas cloud in the image and the gray value is even inside the cloud, strong forward diffusion will be used to reduce the noise and to expand the range of the gas cloud. Frames subtraction and K-means cluttering pop out the gas cloud area. Forward-and-Backward diffusion is to protect background details. Additionally, the best iteration times and the time step parameters are researched. Results show that the gas cloud can be marked correctly and enhanced by black or false color, and so potentially increase the possibility of gas leakage detection.

  15. Graphene-based platform for nano-scale infrared near-field spectroscopy of biological materials

    NASA Astrophysics Data System (ADS)

    Khatib, Omar; Wood, Joshua D.; Doidge, Gregory P.; Damhorst, Gregory L.; Rangarajan, Aniruddh; Bashir, Rashid; Pop, Eric; Lyding, Joseph W.; Basov, Dimitri N.

    2014-03-01

    In biological and life sciences, Fourier Transform Infrared (FTIR) spectroscopy serves as a noninvasive probe of vibrational fingerprints used to identify chemical and molecular species. Near-field spectroscopy, based on the illumination of an atomic force microscope (AFM) tip with an infrared laser, allows for determination of IR properties of a material at nanometer length scales. However, application of near-field IR spectroscopy to most biological systems has thus far been elusive. Physiological conditions required for experimentation are incompatible with typical implementations of nano-FTIR. Recently it became possible to trap water and small biomolecules underneath large-area graphene sheets grown by chemical vapor deposition (CVD). The graphene layer serves as an IR-transparent cover that allows for a near-field interrogation of the underlying layers. We present near-field nano-imaging and spectroscopy data of unencapsulated Tobacco Mosaic Viruses (TMV), compared to those sandwiched between two large-area graphene sheets, and discuss the applicability of near-field IR spectroscopy to trapped biomolecules in aqueous environments.

  16. Quantitative morphological analysis of curvilinear network for microscopic image based on individual fibre segmentation (IFS).

    PubMed

    Qiu, J; Li, F-F

    2014-12-01

    Microscopic images of curvilinear fibre network structure like cytoskeleton are traditionally analysed by qualitative observation, which can hardly provide quantitative information of their morphological properties. However, such information is crucially contributive to the understanding of important biological events, even helps to learn about the inner relations hard to perceive. Individual fibre segmentation-based curvilinear structure detector proposed in this study can identify each individual fibre in the network, as well as connections between different fibres. Quantitative information of each individual fibre, including length, orientation and position, can be extracted; so are the connecting modes in the fibre network, such as bifurcation, intersection and overlap. Distribution of fibres with different morphological properties is also presented. No manual intervening or subjective judging is required in the analysing process. Both synthesized and experimental microscopic images have verified that the detector is capable to segment curvilinear network at the subcellular level with strong noise immunity. The proposed detector is finally applied to the morphological study on cytoskeleton. It is believed that the individual fibre segmentation-based curvilinear structure detector can greatly enhance our understanding of those biological images generated from tons of biological experiments. PMID:25243901

  17. A photoelastic modulator-based birefringence imaging microscope for measuring biological specimens

    NASA Astrophysics Data System (ADS)

    Freudenthal, John; Leadbetter, Andy; Wolf, Jacob; Wang, Baoliang; Segal, Solomon

    2014-11-01

    The photoelastic modulator (PEM) has been applied to a variety of polarimetric measurements. However, nearly all such applications use point-measurements where each point (spot) on the sample is measured one at a time. The main challenge for employing the PEM in a camera-based imaging instrument is that the PEM modulates too fast for typical cameras. The PEM modulates at tens of KHz. To capture the specific polarization information that is carried on the modulation frequency of the PEM, the camera needs to be at least ten times faster. However, the typical frame rates of common cameras are only in the tens or hundreds frames per second. In this paper, we report a PEM-camera birefringence imaging microscope. We use the so-called stroboscopic illumination method to overcome the incompatibility of the high frequency of the PEM to the relatively slow frame rate of a camera. We trigger the LED light source using a field-programmable gate array (FPGA) in synchrony with the modulation of the PEM. We show the measurement results of several standard birefringent samples as a part of the instrument calibration. Furthermore, we show results observed in two birefringent biological specimens, a human skin tissue that contains collagen and a slice of mouse brain that contains bundles of myelinated axonal fibers. Novel applications of this PEM-based birefringence imaging microscope to both research communities and industrial applications are being tested.

  18. Image distortion correction for micromanipulation system based on SLM microscopic vision.

    PubMed

    Wang, Yuezong; Jin, Yan; Wang, Lika

    2016-03-01

    Stereo light microscope (SLM) simulates stereo imaging principle of human eyes. Microscopic vision system based on SLM has become an important visual tool for micro measurement, micromanipulation, and microinjection. We develop a micromanipulation system based on SLM and present an image distortion correction method. We mainly correct two kinds of image distortions: lateral and vertical distortion. Distortion correction consists of two steps. First, a linear fitting algorithm for each row or column of target points is developed, and the fitting errors are calculated. If the fitting errors are smaller than a given threshold, the linear fitting results are kept and used. Otherwise polynomial fitting procedure will be used. Second, the parallelism of straight lines is corrected. The results show that a line in world coordinate frame (WCF) is not necessarily a straight line in image coordinate frame (ICF), or two parallel lines in WCF may be not parallel in ICF. Distortion correction can restore the parallel and linear relationship. For distorted left and right images, the magnitude of distortion exceeds 6 pixels and 4 pixels in the horizontal direction, and 1.2 pixels and 1.7 pixels in the vertical direction, respectively. After corrected, for left and right image, distortion can be reduced to 0.8 pixels and 0.7 pixels in the horizontal direction, and 0.96 pixels and 1.3 pixels in the vertical direction, respectively. The results show that distortion parameters obtained from the proposed method can effectively correct distorted images. PMID:26789139

  19. Microscope-based imaging platform for large-scale analysis of oral biofilms.

    PubMed

    Karygianni, L; Follo, M; Hellwig, E; Burghardt, D; Wolkewitz, M; Anderson, A; Al-Ahmad, A

    2012-12-01

    A microscopic method for noninvasively monitoring oral biofilms at the macroscale was developed to describe the spatial distribution of biofilms of different bacterial composition on bovine enamel surfaces (BES). For this purpose, oral biofilm was grown in situ on BES that were fixed at approximal sites of individual upper jaw acrylic devices worn by a volunteer for 3 or 5 days. Eubacteria, Streptococcus spp., and Fusobacterium nucleatum were stained using specific fluorescence in situ hybridization (FISH) probes. The resulting fluorescence signals were subsequently tested by confocal laser scanning microscopy (CLSM) and monitored by an automated wide-field microscope-based imaging platform (Scan∧R). Automated image processing and data analysis were conducted by microscope-associated software and followed by statistical evaluation of the results. The full segmentation of biofilm images revealed a random distribution of bacteria across the entire area of the enamel surfaces examined. Significant differences in the composition of the microflora were recorded across individual as well as between different enamel surfaces varying from sparsely colonized (47.26%) after 3 days to almost full surface coverage (84.45%) after 5 days. The enamel plates that were positioned at the back or in the middle of the oral cavity were found to be more suitable for the examination of biofilms up to 3 days old. In conclusion, automated microscopy combined with the use of FISH can enable the efficient visualization and meaningful quantification of bacterial composition over the entire sample surface. Due to the possibility of automation, Scan∧R overcomes the technical limitations of conventional CLSM.

  20. An infrared image based methodology for breast lesions screening

    NASA Astrophysics Data System (ADS)

    Morais, K. C. C.; Vargas, J. V. C.; Reisemberger, G. G.; Freitas, F. N. P.; Oliari, S. H.; Brioschi, M. L.; Louveira, M. H.; Spautz, C.; Dias, F. G.; Gasperin, P.; Budel, V. M.; Cordeiro, R. A. G.; Schittini, A. P. P.; Neto, C. D.

    2016-05-01

    The objective of this paper is to evaluate the potential of utilizing a structured methodology for breast lesions screening, based on infrared imaging temperature measurements of a healthy control group to establish expected normality ranges, and of breast cancer patients, previously diagnosed through biopsies of the affected regions. An analysis of the systematic error of the infrared camera skin temperature measurements was conducted in several different regions of the body, by direct comparison to high precision thermistor temperature measurements, showing that infrared camera temperatures are consistently around 2 °C above the thermistor temperatures. Therefore, a method of conjugated gradients is proposed to eliminate the infrared camera direct temperature measurement imprecision, by calculating the temperature difference between two points to cancel out the error. The method takes into account the human body approximate bilateral symmetry, and compares measured dimensionless temperature difference values (Δ θ bar) between two symmetric regions of the patient's breast, that takes into account the breast region, the surrounding ambient and the individual core temperatures, and doing so, the results interpretation for different individuals become simple and non subjective. The range of normal whole breast average dimensionless temperature differences for 101 healthy individuals was determined, and admitting that the breasts temperatures exhibit a unimodal normal distribution, the healthy normal range for each region was considered to be the dimensionless temperature difference plus/minus twice the standard deviation of the measurements, Δ θ bar ‾ + 2σ Δ θ bar ‾ , in order to represent 95% of the population. Forty-seven patients with previously diagnosed breast cancer through biopsies were examined with the method, which was capable of detecting breast abnormalities in 45 cases (96%). Therefore, the conjugated gradients method was considered effective

  1. Infrared imaging based hyperventilation monitoring through respiration rate estimation

    NASA Astrophysics Data System (ADS)

    Basu, Anushree; Routray, Aurobinda; Mukherjee, Rashmi; Shit, Suprosanna

    2016-07-01

    A change in the skin temperature is used as an indicator of physical illness which can be detected through infrared thermography. Thermograms or thermal images can be used as an effective diagnostic tool for monitoring and diagnosis of various diseases. This paper describes an infrared thermography based approach for detecting hyperventilation caused due to stress and anxiety in human beings by computing their respiration rates. The work employs computer vision techniques for tracking the region of interest from thermal video to compute the breath rate. Experiments have been performed on 30 subjects. Corner feature extraction using Minimum Eigenvalue (Shi-Tomasi) algorithm and registration using Kanade Lucas-Tomasi algorithm has been used here. Thermal signature around the extracted region is detected and subsequently filtered through a band pass filter to compute the respiration profile of an individual. If the respiration profile shows unusual pattern and exceeds the threshold we conclude that the person is stressed and tending to hyperventilate. Results obtained are compared with standard contact based methods which have shown significant correlations. It is envisaged that the thermal image based approach not only will help in detecting hyperventilation but can assist in regular stress monitoring as it is non-invasive method.

  2. Multi-element double ring infrared detector based on InSb

    NASA Astrophysics Data System (ADS)

    Li, Mo; Lv, Hui; Guo, Li; Liu, Zhu

    2015-10-01

    A multi-element double ring infrared detector based on InSb p-n photodiodes is presented. The presented detector includes an outer ring detector and an inner ring detector. Each ring consist 10 detector elements, five mid-wave infrared detector elements and five short wave infrared detector elements. Two wavebands of 3.5-5 μm and 1.5-3 μm in mid-wave infrared and short wave infrared are adopted. The mid-wave infrared and short wave infrared detector elements are arranged alternately and close to each other to form detection pair. Between the adjacent detector elements, there is an interval to avoid cross talk. Dual band filter thin films are directly coated on the photodiode surface to form a dual band infrared detector. The double ring detector which can perform dual band IR counter-countermeasures can track target effectively under infrared countermeasure conditions.

  3. Ambient temperature normalization for infrared face recognition based on the second-order polynomial model

    NASA Astrophysics Data System (ADS)

    Wang, Zhengzi

    2015-08-01

    The influence of ambient temperature is a big challenge to robust infrared face recognition. This paper proposes a new ambient temperature normalization algorithm to improve the performance of infrared face recognition under variable ambient temperatures. Based on statistical regression theory, a second order polynomial model is learned to describe the ambient temperature's impact on infrared face image. Then, infrared image was normalized to reference ambient temperature by the second order polynomial model. Finally, this normalization method is applied to infrared face recognition to verify its efficiency. The experiments demonstrate that the proposed temperature normalization method is feasible and can significantly improve the robustness of infrared face recognition.

  4. High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope.

    PubMed

    Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2016-03-01

    In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10(-7) Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies. PMID:27036755

  5. Measurement of PSF for the extended depth of field of microscope based on liquid lens

    NASA Astrophysics Data System (ADS)

    Xue, Yujia; Qu, Yufu; Zhu, Shenyu

    2015-08-01

    To obtain the accurate integral PSF of an extended depth of field (EDOF) microscope based on liquid tunable lens and volumetric sampling (VS) method, a method based on statistic and inverse filtering using quantum dot fluorescence nanosphere as a point source is proposed in this paper. First, a number of raw quantum dot images were captured separately when the focus length of the liquid lens was fixed and changed over the exposure time. Second, the raw images were separately added and averaged to obtain two noise-free mean images. Third, the integral PSF was achieved by computing the inverse Fourier transform of the mean image's Fourier transform caught when the focus lens is fixed divided by that when the focus length is changed. Finally, experimental results show that restored image using the measured accumulated PSF has good image quality and no artifacts.

  6. Indoor infrared wireless communication system based on Ethernet network

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Gong, Mali; Zhang, Kai; Zhang, Haitao; Yan, Ping; Jin, Wei; Jiang, Feng; Meng, Yu; Zou, Shanshan

    2002-12-01

    In this paper, we present an infrared wireless indoor communication system that bases on Ethernet network. The bit rate of Ethernet is 10Mbps, but after Manchester coding, in the physical layer the actual bit rate is 20Mbps. In our designs, the transmitter uses laser diodes (LDs). The transmitter consists of differential input circuit, LD driver circuit. The receiver consists of a coated truncated spherical concentrator whose field of view (FOV) is 40 degree, a large area Si PIN photo-detector followed by transimpedance amplifier, second-stage amplifier, low-pass filter (LPF), high-pass filter (HPF), limiting amplifier and differential output circuit. The network is constructed as a base-terminals configuration and two transit wavelengths are used for base and terminals respectively to avoid collision. Experimental testing was conducted in a room with size 5m × 5m × 3m and the network could work well.

  7. Defects evaluation system for spherical optical surfaces based on microscopic scattering dark-field imaging method.

    PubMed

    Zhang, Yihui; Yang, Yongying; Li, Chen; Wu, Fan; Chai, Huiting; Yan, Kai; Zhou, Lin; Li, Yang; Liu, Dong; Bai, Jian; Shen, Yibing

    2016-08-10

    In the field of automatic optical inspection, it is imperative to measure the defects on spherical optical surfaces. So a novel spherical surface defect evaluation system is established in this paper to evaluate defects on optical spheres. In order to ensure the microscopic scattering dark-field imaging of optical spheres with different surface shape and radius of curvature, illumination with variable aperture angle is employed. In addition, the scanning path of subapertures along the parallels and meridians is planned to detect the large optical spheres. Since analysis shows that the spherical defect information could be lost in the optical imaging, the three-dimensional correction based on a pin-hole model is proposed to recover the actual spherical defects from the captured two-dimensional images. Given the difficulty of subaperture stitching and defect feature extraction in three-dimensional (3D) space after the correction, the 3D subapertures are transformed into a plane to be spliced through geometric projection. Then, methods of the surface integral and calibration are applied to quantitatively evaluate the spherical defects. Furthermore, the 3D panorama of defect distribution on the spherical optical components can be displayed through the inverse projective reconstruction. Finally, the evaluation results are compared with the OLYMPUS microscope, testifying to the micrometer resolution, and the detection error is less than 5%. PMID:27534456

  8. A scanning measurement method of the pitch of grating based on photoelectric microscope

    NASA Astrophysics Data System (ADS)

    Gao, Hongtang; Wang, Zhongyu; Wang, Hao

    2015-10-01

    Grating is an important sensor widely used in CNC machine or equipment for length measurement with high precision. Special line scales with dense and micro lines are also widely used for the calibration of length measurement instrument. All the pitches of grating and spaces of dense lines of line scale are needed to be calibrated for a good measurement application. General methods for measurement of dense and micro lines include digital image processing method by CCD Microscope or line scanning method by AFM or SEM, and laser distraction method. There are some disadvantages to measure a long length grating with high precision and efficiently in these methods. A dynamic method based on Photoelectric Microscope is introduced, the lines of grating to be measured is moving uniformly when measuring, and the working distance is a bigger 65mm, the zoom of objective is low 10X. The principle of this dynamic method is discussed and the distortion of line signal is analyzed. The way to decrease the affection caused by distortion of line signal is also described. A special glass grating line scale with length 10mm, space 10μm and width 5μm is measured to verify the method. The measurement result and the uncertainty analysis demonstrate the expand measurement uncertainty (k=2) is less than 0.1μm.

  9. Single-spin microscope with sub-nanoscale resolution based on optically detected magnetic resonance

    SciTech Connect

    Berman, Gennady P; Chernobrod, Boris

    2009-01-01

    Invention of scanning tunneling microscope (STM) and atomic force microscope (AFM) initiated a new era of material science and technology characterized by 2-D imaging with atomic resolution and manipulation of individual atoms. However, for further progress in material science, and in particular in structural biology, 3-D imaging with sub-nanometer resolution is very desirable. Currently the most promising technique for 3-D imaging is magnetic resonance force microscopy (MRFM), which senses individual electron spins [1,2] with nanoscale resolution and can detect collective magnetization of about 100 nuclear spins [3]. The highest sensitivity demonstrated by MRFM is based on a time modulation technique called the oscillating cantilever-driven adiabatic reversals (OSCAAR) which requires a long phase relaxation time T 2 of measured spins, which usually corresponds to rather low temperature. For example, a temperature of 300 mK was used in the case of 3D imaging of the tobacco mosaic virus [3]. This limitation is incompatible with the room-temperature operation needed for the study of biological systems under physiological conditions.

  10. Learning-based compressed sensing for infrared image super resolution

    NASA Astrophysics Data System (ADS)

    Zhao, Yao; Sui, Xiubao; Chen, Qian; Wu, Shaochi

    2016-05-01

    This paper presents an infrared image super-resolution method based on compressed sensing (CS). First, the reconstruction model under the CS framework is established and a Toeplitz matrix is selected as the sensing matrix. Compared with traditional learning-based methods, the proposed method uses a set of sub-dictionaries instead of two coupled dictionaries to recover high resolution (HR) images. And Toeplitz sensing matrix allows the proposed method time-efficient. Second, all training samples are divided into several feature spaces by using the proposed adaptive k-means classification method, which is more accurate than the standard k-means method. On the basis of this approach, a complex nonlinear mapping from the HR space to low resolution (LR) space can be converted into several compact linear mappings. Finally, the relationships between HR and LR image patches can be obtained by multi-sub-dictionaries and HR infrared images are reconstructed by the input LR images and multi-sub-dictionaries. The experimental results show that the proposed method is quantitatively and qualitatively more effective than other state-of-the-art methods.

  11. Infrared imaging-based combat casualty care system

    NASA Astrophysics Data System (ADS)

    Davidson, James E., Sr.

    1997-08-01

    A Small Business Innovative Research (SBIR) contract was recently awarded to a start up company for the development of an infrared (IR) image based combat casualty care system. The company, Medical Thermal Diagnostics, or MTD, is developing a light weight, hands free, energy efficient uncooled IR imaging system based upon a Texas Instruments design which will allow emergency medical treatment of wounded soldiers in complete darkness without any type of light enhancement equipment. The principal investigator for this effort, Dr. Gene Luther, DVM, Ph.D., Professor Emeritus, LSU School of Veterinary Medicine, will conduct the development and testing of this system with support from Thermalscan, Inc., a nondestructive testing company experienced in IR thermography applications. Initial research has been done with surgery on a cat for feasibility of the concept as well as forensic research on pigs as a close representation of human physiology to determine time of death. Further such studies will be done later as well as trauma studies. IR images of trauma injuries will be acquired by imaging emergency room patients to create an archive of emergency medical situations seen with an infrared imaging camera. This archived data will then be used to develop training material for medical personnel using the system. This system has potential beyond military applications. Firefighters and emergency medical technicians could directly benefit from the capability to triage and administer medical care to trauma victims in low or no light conditions.

  12. Photoacoustic-based detector for infrared laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Scholz, L.; Palzer, S.

    2016-07-01

    In this contribution, we present an alternative detector technology for use in direct absorption spectroscopy setups. Instead of a semiconductor based detector, we use the photoacoustic effect to gauge the light intensity. To this end, the target gas species is hermetically sealed under excess pressure inside a miniature cell along with a MEMS microphone. Optical access to the cell is provided by a quartz window. The approach is particularly suitable for tunable diode laser spectroscopy in the mid-infrared range, where numerous molecules exhibit large absorption cross sections. Moreover, a frequency standard is integrated into the method since the number density and pressure inside the cell are constant. We demonstrate that the information extracted by our method is at least equivalent to that achieved using a semiconductor-based photon detector. As exemplary and highly relevant target gas, we have performed direct spectroscopy of methane at the R3-line of the 2v3 band at 6046.95 cm-1 using both detector technologies in parallel. The results may be transferred to other infrared-active transitions without loss of generality.

  13. MEMS-based uncooled infrared bolometer arrays: a review

    NASA Astrophysics Data System (ADS)

    Niklaus, Frank; Vieider, Christian; Jakobsen, Henrik

    2008-03-01

    Uncooled infrared bolometer arrays have become the technology of choice for low-cost infrared imaging systems used in applications such as thermography, firefighting, driver night vision, security and surveillance. Uncooled infrared bolometer arrays are reaching performance levels which previously only were possible with cooled infrared photon detectors. With a continuously increasing market volume (> 100 000 units per year to date), the cost for uncooled infrared imaging chips are decreasing accordingly. In this paper we give an overview of the historical development of uncooled infrared bolometer technology and present the most important bolometer performance parameters. The different technology concepts, bolometer design approaches and bolometer materials (including vanadium oxide, amorphous silicon, silicon diodes, silicon-germanium and metals) are discussed in detail. This is followed by an analysis of the current state-of-the-art infrared bolometer technologies, the status of the infrared industry and the latest technology trends.

  14. All-plastic miniature fluorescence microscope for point-of-care readout of bead-based bioassays

    NASA Astrophysics Data System (ADS)

    Forcucci, Alessandra; Pawlowski, Michal Emanuel; Crannell, Zachary; Pavlova, Ina; Richards-Kortum, Rebecca; Tkaczyk, Tomasz S.

    2015-10-01

    A number of new platforms have been developed for multiplexed bioassays that rely on imaging targeted fluorescent beads labeled with different fluorescent dyes. We developed a compact, low-cost three-dimensional printed fluorescence microscope that can be used as a detector for mutiplexed, bead-based assays to support point-of-care applications. Images obtained with the microscope were analyzed to differentiate multiple analytes in a single sample with a comparable limit of detection to commercially available macroscopic assay platforms.

  15. A magneto-optical scheme of a proton microscope based on the U-70 synchrotron radiograph complex

    NASA Astrophysics Data System (ADS)

    Maksimov, A. V.; Fedotov, Yu. S.

    2016-07-01

    A magneto-optical scheme of a proton microscope based on an active U-70 accelerator radiography complex is presented. The microscope is created in the magnetic structure of the radiography complex only by changing strengths of quadrupole lenses without changing their position. The achieved magnification ratio of the image of the studied object is no smaller than 10 at E = 60 GeV. This is sufficient for a spatial resolution of images of 10-20 μm.

  16. Enabling scanning electron microscope contour-based optical proximity correction models

    NASA Astrophysics Data System (ADS)

    Weisbuch, François; Jantzen, Kenneth

    2015-04-01

    A scanning electron microscope (SEM) is the metrology tool used to accurately characterize very fine structures on wafers, usually by extracting one critical dimension (CD) per SEM image. This approach for optical proximity correction (OPC) modeling requires many measurements resulting in a lengthy cycle time for data collection, review, and cleaning, and faces reliability issues when dealing with critical two-dimensional (2-D) structures. An alternative to CD-based metrology is to use SEM image contours for OPC modeling. To calibrate OPC models with contours, reliable contours matched to traditional CD-SEM measurements are required along with a method to choose structure and site selections (number, type, and image space coverage) specific to a contour-based OPC model calibration. The potential of SEM contour model-based calibration is illustrated by comparing two contour-based models to reference models, one empirical model and a second rigorous simulation-based model. The contour-based models are as good as or better than a CD-based model with a significant advantage in the prediction of complex 2-D configurations with a reduced metrology work load.

  17. Research of infrared laser based pavement imaging and crack detection

    NASA Astrophysics Data System (ADS)

    Hong, Hanyu; Wang, Shu; Zhang, Xiuhua; Jing, Genqiang

    2013-08-01

    Road crack detection is seriously affected by many factors in actual applications, such as some shadows, road signs, oil stains, high frequency noise and so on. Due to these factors, the current crack detection methods can not distinguish the cracks in complex scenes. In order to solve this problem, a novel method based on infrared laser pavement imaging is proposed. Firstly, single sensor laser pavement imaging system is adopted to obtain pavement images, high power laser line projector is well used to resist various shadows. Secondly, the crack extraction algorithm which has merged multiple features intelligently is proposed to extract crack information. In this step, the non-negative feature and contrast feature are used to extract the basic crack information, and circular projection based on linearity feature is applied to enhance the crack area and eliminate noise. A series of experiments have been performed to test the proposed method, which shows that the proposed automatic extraction method is effective and advanced.

  18. Scattering assisted injection based injectorless mid infrared quantum cascade laser

    SciTech Connect

    Singh, Siddharth Kamoua, Ridha

    2014-06-07

    An injectorless five-well mid infrared quantum cascade laser is analyzed which relies on phonon scattering injection in contrast to resonant tunneling injection, which has been previously used for injectorless designs. A Monte Carlo based self-consistent electron and photon transport simulator is used to analyze the performance of the analyzed design and compare it to existing injectorless designs. The simulation results show that the analyzed design could greatly enhance the optical gain and the characteristic temperatures of injectorless quantum cascade lasers (QCLs) which have typically been hindered by low characteristic temperatures and significant temperature related performance degradation. Simulations of the analyzed device predict threshold current densities of 0.85 kA/cm{sup 2} and 1.95 kA/cm{sup 2} at 77 K and 300 K, respectively, which are comparable to the threshold current densities of conventional injector based QCLs.

  19. Infrared small target detection based on Danger Theory

    NASA Astrophysics Data System (ADS)

    Lan, Jinhui; Yang, Xiao

    2009-11-01

    To solve the problem that traditional method can't detect the small objects whose local SNR is less than 2 in IR images, a Danger Theory-based model to detect infrared small target is presented in this paper. First, on the analog with immunology, the definition is given, in this paper, to such terms as dangerous signal, antigens, APC, antibodies. Besides, matching rule between antigen and antibody is improved. Prior to training the detection model and detecting the targets, the IR images are processed utilizing adaptive smooth filter to decrease the stochastic noise. Then at the training process, deleting rule, generating rule, crossover rule and the mutation rule are established after a large number of experiments in order to realize immediate convergence and obtain good antibodies. The Danger Theory-based model is built after the training process, and this model can detect the target whose local SNR is only 1.5.

  20. Compression of multispectral fluorescence microscopic images based on a modified set partitioning in hierarchal trees

    NASA Astrophysics Data System (ADS)

    Mansoor, Awais; Robinson, J. Paul; Rajwa, Bartek

    2009-02-01

    Modern automated microscopic imaging techniques such as high-content screening (HCS), high-throughput screening, 4D imaging, and multispectral imaging are capable of producing hundreds to thousands of images per experiment. For quick retrieval, fast transmission, and storage economy, these images should be saved in a compressed format. A considerable number of techniques based on interband and intraband redundancies of multispectral images have been proposed in the literature for the compression of multispectral and 3D temporal data. However, these works have been carried out mostly in the elds of remote sensing and video processing. Compression for multispectral optical microscopy imaging, with its own set of specialized requirements, has remained under-investigated. Digital photography{oriented 2D compression techniques like JPEG (ISO/IEC IS 10918-1) and JPEG2000 (ISO/IEC 15444-1) are generally adopted for multispectral images which optimize visual quality but do not necessarily preserve the integrity of scientic data, not to mention the suboptimal performance of 2D compression techniques in compressing 3D images. Herein we report our work on a new low bit-rate wavelet-based compression scheme for multispectral fluorescence biological imaging. The sparsity of signicant coefficients in high-frequency subbands of multispectral microscopic images is found to be much greater than in natural images; therefore a quad-tree concept such as Said et al.'s SPIHT1 along with correlation of insignicant wavelet coefficients has been proposed to further exploit redundancy at high-frequency subbands. Our work propose a 3D extension to SPIHT, incorporating a new hierarchal inter- and intra-spectral relationship amongst the coefficients of 3D wavelet-decomposed image. The new relationship, apart from adopting the parent-child relationship of classical SPIHT, also brought forth the conditional "sibling" relationship by relating only the insignicant wavelet coefficients of subbands

  1. Design and implementation of a fs-resolved transmission electron microscope based on thermionic gun technology

    NASA Astrophysics Data System (ADS)

    Piazza, L.; Masiel, D. J.; LaGrange, T.; Reed, B. W.; Barwick, B.; Carbone, Fabrizio

    2013-09-01

    In this paper, the design and implementation of a femtosecond-resolved ultrafast transmission electron microscope is presented, based on a thermionic gun geometry. Utilizing an additional magnetic lens between the electron acceleration and the nominal condenser lens system, a larger percentage of the electrons created at the cathode are delivered to the specimen without degrading temporal, spatial and energy resolution significantly, while at the same time maintaining the femtosecond temporal resolution. Using the photon-induced near field electron microscopy effect (PINEM) on silver nanowires the cross-correlation between the light and electron pulses was measured, showing the impact of the gun settings and initiating laser pulse duration on the electron bunch properties. Tuneable electron pulses between 300 fs and several ps can be obtained, and an overall energy resolution around 1 eV was achieved.

  2. Efficient alignment scheme for zone-plates-based transmission soft X-ray microscope

    NASA Astrophysics Data System (ADS)

    Lim, Jun; Shin, Hyun-Joon; Hong, Chung Ki

    2010-12-01

    Alignment and operation of a zone-plate (ZP)-based transmission soft X-ray microscope (TXM) is difficult and time consuming, especially when the TXM has no dedicated X-ray source. We introduce here an efficient TXM alignment scheme. The TXM employed is a simple in-situ-experiment-capable setup. It includes ultrahigh-vacuum (UHV)-compatible conflat flanges and is mountable in tandem with any soft X-ray synchrotron radiation beamlines. Obtaining zeroth- and first-order diffracted (condenser-zone-plate [CZP]-focused) beams simultaneously by means of the objective zone plate (OZP) is the most essential step in the alignment scheme. We were able to acquire, in one hour at a radiation wavelength of 2.49 nm, an image of 50 nm spatial resolution.

  3. Development of Novel System Combining Scanning Tunneling Microscope-Based Cathodoluminescence and Electroluminescence Nanospectroscopies

    NASA Astrophysics Data System (ADS)

    Watanabe, Kentaro; Nakamura, Yoshiaki; Kuboya, Shigeyuki; Katayama, Ryuji; Onabe, Kentaro; Ichikawa, Masakazu

    2011-08-01

    Novel system equipped with conductive optical fiber probe scanning tunneling microscope (STM) and bipolar sample holder is a powerful tool to characterize light-emitting devices by several STM-based techniques at the same sample position, which can realize photoluminescence (PL), cathodoluminescence (CL), electroluminescence (EL), and electron beam induced current (EBIC) measurements with higher spatial resolutions than conventional techniques. In this study, we developed a STM-CL/EL system which combines STM-CL technique for high CL excitation power and high spatial resolution and STM-EL technique for local EL collection. We demonstrated spatially resolved STM-CL/EL spectroscopy of GaAs/AlGaAs heterostructure (110) cross-sections.

  4. Protective infrared antireflection coating based on sputtered germanium carbide

    NASA Astrophysics Data System (ADS)

    Gibson, Des; Waddell, Ewan; Placido, Frank

    2011-09-01

    This paper describes optical, durablility and environmental performance of a germanium carbide based durable antireflection coating. The coating has been demonstrated on germanium and zinc selenide infra-red material however is applicable to other materials such as zinc sulphide. The material is deposited using a novel reactive closed field magnetron sputtering technique, offering significant advantages over conventional evaporation processes for germanium carbide such as plasma enhanced chemical vapour deposition. The sputtering process is "cold", making it suitable for use on a wide range of substrates. Moreover, the drum format provide more efficient loading for high throughput production. The use of the closed field and unbalanced magnetrons creates a magnetic confinement that extends the electron mean free path leading to high ion current densities. The combination of high current densities with ion energies in the range ~30eV creates optimum thin film growth conditions. As a result the films are dense, spectrally stable, supersmooth and low stress. Films incorporate low hydrogen content resulting in minimal C-H absorption bands within critical infra-red passbands such as 3 to 5um and 8 to 12um. Tuning of germanium carbide (Ge(1-x)Cx) film refractive index from pure germanium (refractive index 4) to pure germanium carbide (refractive index 1.8) will be demonstrated. Use of film grading to achieve single and dual band anti-reflection performance will be shown. Environmental and durability levels are shown to be suitable for use in harsh external environments.

  5. SPY: a new scission-point model based on microscopic inputs to predict fission fragment properties

    NASA Astrophysics Data System (ADS)

    Panebianco, Stefano; Dubray, Nöel; Goriely, Stéphane; Hilaire, Stéphane; Lemaître, Jean-François; Sida, Jean-Luc

    2014-04-01

    Despite the difficulty in describing the whole fission dynamics, the main fragment characteristics can be determined in a static approach based on a so-called scission-point model. Within this framework, a new Scission-Point model for the calculations of fission fragment Yields (SPY) has been developed. This model, initially based on the approach developed by Wilkins in the late seventies, consists in performing a static energy balance at scission, where the two fragments are supposed to be completely separated so that their macroscopic properties (mass and charge) can be considered as fixed. Given the knowledge of the system state density, averaged quantities such as mass and charge yields, mean kinetic and excitation energy can then be extracted in the framework of a microcanonical statistical description. The main advantage of the SPY model is the introduction of one of the most up-to-date microscopic descriptions of the nucleus for the individual energy of each fragment and, in the future, for their state density. These quantities are obtained in the framework of HFB calculations using the Gogny nucleon-nucleon interaction, ensuring an overall coherence of the model. Starting from a description of the SPY model and its main features, a comparison between the SPY predictions and experimental data will be discussed for some specific cases, from light nuclei around mercury to major actinides. Moreover, extensive predictions over the whole chart of nuclides will be discussed, with particular attention to their implication in stellar nucleosynthesis. Finally, future developments, mainly concerning the introduction of microscopic state densities, will be briefly discussed.

  6. Infrared near-field imaging and spectroscopy based on thermal or synchrotron radiation

    SciTech Connect

    Peragut, Florian; De Wilde, Yannick; Brubach, Jean-Blaise; Roy, Pascale

    2014-06-23

    We demonstrate the coupling of a scattering near-field scanning optical microscope combined with a Fourier transform infrared spectrometer. The set-up operates using either the near-field thermal emission from the sample itself, which is proportional to the electromagnetic local density of states, or with an external infrared synchrotron source, which is broadband and highly brilliant. We perform imaging and spectroscopy measurements with sub-wavelength spatial resolution in the mid-infrared range on surfaces made of silicon carbide and gold and demonstrate the capabilities of the two configurations for super-resolved near-field mid-infrared hyperspectral imaging and that the simple use of a properly chosen bandpass filter on the detector allows one to image the spatial distribution of materials with sub-wavelength resolution by studying the contrast in the near-field images.

  7. Integrity of the interface between denture base and soft liner: a scanning electron microscopic study.

    PubMed

    Muralidhar, G; Satish Babu, C L; Shetty, Shilpa

    2012-06-01

    Aims and objectives of the study was to study the integrity of the interface between the denture base and the soft liner when the thickness of the soft liner was 0.5, 1.0 and 2.0 mm, and to study the integrity of the soft liner and denture base interface as influenced by aging process. 80 rectangular based specimens were fabricated using heat cured acrylic resin. The heat cured component of the specimen was fabricated from stainless steel template form by compression molding technique. Different thickness of silicone soft layer component was added to heat cured acrylic resin component of the specimen following the manufacturer's instructions to fabricate the group A, group B, group C and group D specimens. All the specimens were subjected to the same finishing and polishing procedures. The group A specimens was immediately scanned in scanning electron microscope after processing. A thermo statically controlled artificial saliva bath designed to maintain the temperature between 38 ± 4°C was used to simulate the oral condition and to age the group B, group C and group D specimens for 3 months after which they were subjected to scanning under a scanning electron microscope. All the aged specimens demonstrated two types of failures namely adhesive which occurred along the bond interface between the soft liner and the acrylic resin and adhesive and cohesive type of failure which occurred not only at the interface but also within the soft liner material itself. When the data was subjected to ANOVA, the group A specimens showed statistical significance with group B (P = 0.006), group C (P = 0.007) and group D specimens (P = 0.004), the level of significance being (P < 0.05). However, there was no statistical significance between group B and C (P = 0.98), group C and D specimens (P = 0.52), group B and D specimens (P = 0.70), the level of significance being (P < 0.05). Based on the results, statistical analysis of the results and within the

  8. Integrity of the interface between denture base and soft liner: a scanning electron microscopic study.

    PubMed

    Muralidhar, G; Satish Babu, C L; Shetty, Shilpa

    2012-06-01

    Aims and objectives of the study was to study the integrity of the interface between the denture base and the soft liner when the thickness of the soft liner was 0.5, 1.0 and 2.0 mm, and to study the integrity of the soft liner and denture base interface as influenced by aging process. 80 rectangular based specimens were fabricated using heat cured acrylic resin. The heat cured component of the specimen was fabricated from stainless steel template form by compression molding technique. Different thickness of silicone soft layer component was added to heat cured acrylic resin component of the specimen following the manufacturer's instructions to fabricate the group A, group B, group C and group D specimens. All the specimens were subjected to the same finishing and polishing procedures. The group A specimens was immediately scanned in scanning electron microscope after processing. A thermo statically controlled artificial saliva bath designed to maintain the temperature between 38 ± 4°C was used to simulate the oral condition and to age the group B, group C and group D specimens for 3 months after which they were subjected to scanning under a scanning electron microscope. All the aged specimens demonstrated two types of failures namely adhesive which occurred along the bond interface between the soft liner and the acrylic resin and adhesive and cohesive type of failure which occurred not only at the interface but also within the soft liner material itself. When the data was subjected to ANOVA, the group A specimens showed statistical significance with group B (P = 0.006), group C (P = 0.007) and group D specimens (P = 0.004), the level of significance being (P < 0.05). However, there was no statistical significance between group B and C (P = 0.98), group C and D specimens (P = 0.52), group B and D specimens (P = 0.70), the level of significance being (P < 0.05). Based on the results, statistical analysis of the results and within the

  9. Infrared micro- and nano-spectroscopy of carbon-based materials

    NASA Astrophysics Data System (ADS)

    Khatib, Omar

    The following dissertation explores the low-energy physics and infrared properties associated with a suite of organic and molecular materials. The majority of the work is centered around organic semiconductors, specifically conducting polymers. First, we explore a novel method of charge injection in organic semiconductors involving exposure to vapors of fluorinated organosilane molecules. We show that ultra-high carrier densities in the range 10 14 cm-2 are attainable, a regime that is inaccessable by conventional oxide-based electrostatic field-effect. Further, we provide spectroscopic evidence of delocalized states and thus metallic transport, signaling that such highly-doped polymer films are at the threshold of the metal-insulator transition, an area of both high academic and practical interest. The next two sections explore a new class of narrow bandgap donor-acceptor (DA) copolymers, based on benzobisthiadiazole (BBT) and diketopyrrolopyrrole (DPP), that demonstrate intrinsic ambipolarity when integrated in field-effect transistors. We perform a systematic infrared investigation of thin film transistors based on DA copolymers. We study the electronic excitations under both positive and negative gate biases, to determine the electron- and hole-induced IR spectral features. For high-mobility polymer films based on DPP, we observe distinct polaronic absorption features associated with both electrons and holes. We employ a customized diffraction-limited IR microscope to study the evolution of the electronic response throughout the channel of a functional field-effect transistor device. From the strength of the IR absorptions, we are able to map the carrier density across the conduction channel. When biased at moderate gate biases in the 'ambipolar regime' where electrons and holes coexist in the channel, we register the transition from electron-polaron to hole-polaron IR absorption as a function of position. The last section explores an entirely new concept in

  10. Infrared Fibers for Use in Space-Based Smart Structures

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S.; Nettles, Alan T.; Brantley, Lott W. (Technical Monitor)

    2001-01-01

    Infrared optical fibers are finding a number of applications including laser surgery, remote sensing, and nuclear radiation resistant links. Utilizing these fibers in space-based structures is another application, which can be exploited. Acoustic and thermal sensing are two areas in which these fibers could be utilized. In particular, fibers could be embedded in IM7/8552 toughened epoxy and incorporated into space structures both external and internal. ZBLAN optical fibers are a candidate, which have been studied extensively over the past 20 years for terrestrial applications. For the past seven years the effects of gravity on the crystallization behavior of ZBLAN optical fiber has been studied. It has been found that ZBLAN crystallization is suppressed in microgravity. This lack of crystallization leads to a fiber with better transmission characteristics than its terrestrial counterpart.

  11. Optical-based spectral modeling of infrared focal plane arrays

    NASA Astrophysics Data System (ADS)

    Mouzali, Salima; Lefebvre, Sidonie; Rommeluère, Sylvain; Ferrec, Yann; Primot, Jérôme

    2016-07-01

    We adopt an optical approach in order to model and predict the spectral signature of an infrared focal plane array. The modeling is based on a multilayer description of the structure and considers a one-dimensional propagation. It provides a better understanding of the physical phenomena occurring within the pixels, which is useful to perform radiometric measurements, as well as to reliably predict the spectral sensitivity of the detector. An exhaustive model is presented, covering the total spectral range of the pixel response. A heuristic model is also described, depicting a complementary approach that separates the different optical phenomena inside the pixel structure. Promising results are presented, validating the models through comparison with experimental results. Finally, advantages and limitations of this approach are discussed.

  12. Infrared and visible images fusion based on RPCA and NSCT

    NASA Astrophysics Data System (ADS)

    Fu, Zhizhong; Wang, Xue; Xu, Jin; Zhou, Ning; Zhao, Yufei

    2016-07-01

    Current infrared and visible images fusion algorithms cannot efficiently extract the object information in the infrared image while retaining the background information in visible image. To address this issue, we propose a new infrared and visible image fusion algorithm by taking advantage of robust principal component analysis (RPCA) and non-subsampled Contourlet transform (NSCT). Firstly, RPCA decomposition is performed on the infrared and visible images respectively to obtain their corresponding sparse matrixes, which can well represent the sparse feature of images. Secondly, the infrared and visible images are decomposed into low frequency sub-band and high-frequency sub-band coefficients by using NSCT. Subsequently, the sparse matrixes are used to guide the fusion rule of low frequency sub-band coefficients and high frequency sub-band coefficients. Experimental results demonstrate that our fusion algorithm can highlight the infrared objects as well as retain the background information in visible image.

  13. Progress report towards a digital mirror device based confocal microscopic system

    NASA Astrophysics Data System (ADS)

    Yi, Dingrong; Lin, Shunhua; Huang, Simian; Xie, Shaochuan

    2013-12-01

    It is widely believed that by using a digital mirror device (DMD) as the spatial light modulator (SLM) of a programmable array microcopy (PAM), it is possible to achieve a cost-effective alternative to expensive confocal imaging devices. During the past decade, the design of such a DMD based PAM instrument has been frequently reported to enhance resolution and contrast, convincing images with improved quality are rare to be seen. The concrete implementation of a DMD based PAM instrument needs to successfully resolve multiple issues such as the adverse effects caused by the tilt angle of the micro-mirrors from the base board, the registration between a micro mirror of the DMD and the image pixel of the photo-detector and so on. In this paper, we report the design of a middle body consisting of a DMD as an independent attachment to a conventional microscope to convert the latter into a confocal imaging system, in a similar way as a filter turret that is placed below the head and the objectives of a regular microscopy to convert it into a fluorescent microscopy. Images of real objects with improved contrast are provided to demonstrate the effectiveness of using a DMD as SLM to improve the contrast of a PAM instrument. Such a PAM instrument has many advantages compared to conventional laser-scanning confocal systems including lower costs and higher imaging speeds. In addition, it allows convenient dynamic adjustments between imaging quality and imaging speed.

  14. Microscopic and infrared spectroscopic comparison of the underwater adhesives produced by germlings of the brown seaweed species Durvillaea antarctica and Hormosira banksii.

    PubMed

    Dimartino, Simone; Savory, David M; Fraser-Miller, Sara J; Gordon, Keith C; McQuillan, A James

    2016-04-01

    Adhesives from marine organisms are often the source of inspiration for the development of glues able to create durable bonds in wet environments. In this work, we investigated the adhesive secretions produced by germlings of two large seaweed species from the South Pacific, Durvillaea antarctica, also named 'the strongest kelp in the word', and its close relative Hormosira banksii The comparative analysis was based on optical and scanning electron microscopy imaging as well as Fourier transform infrared (FTIR) spectroscopy and principal component analysis (PCA). For both species, the egg surface presents peripheral vesicles which are released soon after fertilization to discharge a primary adhesive. This is characterized by peaks representative of carbohydrate molecules. A secondary protein-based adhesive is then secreted in the early developmental stages of the germlings. Energy dispersive X-ray, FTIR and PCA indicate that D. antarctica secretions also contain sulfated moieties, and become cross-linked with time, both conferring strong adhesive and cohesive properties. On the other hand, H. banksii secretions are complemented by the putative adhesive phlorotannins, and are characterized by a simple mechanism in which all constituents are released with the same rate and with no apparent cross-linking. It is also noted that the release of adhesive materials appears to be faster and more copious in D. antarctica than in H. banksii Overall, this study highlights that both quantity and quality of the adhesives matter in explaining the superior attachment ability of D. antarctica. PMID:27122179

  15. A registration based nonuniformity correction algorithm for infrared line scanner

    NASA Astrophysics Data System (ADS)

    Liu, Zhe; Ma, Yong; Huang, Jun; Fan, Fan; Ma, Jiayi

    2016-05-01

    A scene-based algorithm is developed for nonuniformity correction in focal plane of line scanning infrared imaging systems (LSIR) based on registration. By utilizing the 2D shift between consecutive frames, an implicit scheme is proposed to determine correction coefficients. All nonuniform biases are corrected to the same designated value, without estimating and removing biases explicitly, permitting quick computation for high-quality nonuniformity correction. Firstly, scene motion is estimated by image registration and consecutive frames exhibiting required 2D subpixel shift are collected. Secondly, we retrieve the difference matrix of adjacent biases by utilizing the 2D shift between consecutive frames. Thirdly, we perform specified elementary transformations and corresponding cumulative sums to the difference matrix to obtain a bias compensator. This bias compensator converts nonuniform biases to a designated detector's bias. Finally, based on the different bias compensators obtained from several frame pairs, we calculate an averaged bias compensator for nonuniformity correction with less error. Quantitative comparisons with other nonuniformity correction methods demonstrate that the proposed algorithm achieves better fixed-pattern noise reduction with low computational complexity.

  16. Broadband dielectric characterization of aqueous saline solutions by an interferometer-based microwave microscope

    NASA Astrophysics Data System (ADS)

    Gu, Sijia; Lin, Tianjun; Lasri, Tuami

    2016-06-01

    The complex dielectric permittivity of aqueous saline solutions has been determined in the frequency range [2-18 GHz] with a home-made near-field microwave microscope. The instrument is built on a vector network analyzer, a matching network, and an evanescent microwave probe. The interferometer-based matching network enables highly reproducible, sensitive, and accurate measurements on the entire frequency band of operation. NaCl solutions concentrations ranging from 0 to 160 mg/ml are investigated at 25 °C. A maximum measurement sensitivity for NaCl concentrations is found to be equal to 2.3 dB/(mg/ml) and 7.7°/(mg/ml) for magnitude and phase-shift, respectively. To translate the measurement data (S parameters) to the corresponding complex permittivities, an inversion procedure based on a simple calibration model is applied. The resulting complex permittivities are found to be in a very good agreement with those calculated by Cole-Cole model.

  17. A wide field-of-view microscope based on holographic focus grid

    NASA Astrophysics Data System (ADS)

    Wu, Jigang; Cui, Xiquan; Zheng, Guoan; Lee, Lap Man; Yang, Changhuei

    2010-02-01

    We have developed a novel microscope technique that can achieve wide field-of-view (FOV) imaging and yet possess resolution that is comparable to conventional microscope. The principle of wide FOV microscope system breaks the link between resolution and FOV magnitude of traditional microscopes. Furthermore, by eliminating bulky optical elements from its design and utilizing holographic optical elements, the wide FOV microscope system is more cost-effective. In our system, a hologram was made to focus incoming collimated beam into a focus grid. The sample is put in the focal plane and the transmissions of the focuses are detected by an imaging sensor. By scanning the incident angle of the incoming beam, the focus grid will scan across the sample and the time-varying transmission can be detected. We can then reconstruct the transmission image of the sample. The resolution of microscopic image is limited by the size of the focus formed by the hologram. The scanning area of each focus spot is determined by the separation of the focus spots and can be made small for fast imaging speed. We have fabricated a prototype system with a 2.4-mm FOV and 1-μm resolution. The prototype system was used to image onion skin cells for a demonstration. The preliminary experiments prove the feasibility of the wide FOV microscope technique, and the possibility of a wider FOV system with better resolution.

  18. A homemade atomic force microscope based on a quartz tuning fork for undergraduate instruction

    NASA Astrophysics Data System (ADS)

    Li, Yingzi; Zhang, Liwen; Shan, Guanqiao; Song, Zihang; Yang, Rui; Li, Hua; Qian, Jianqiang

    2016-06-01

    Atomic force microscopes are a key tool in nanotechnology that overcome the limitations of optical microscopes and provide imaging capabilities with nanoscale resolution. We have developed an atomic force microscope that uses an inexpensive quartz tuning fork as a micro cantilever. Because of its ease of operation and its open structure, it can be easily customized by students. Due to its low costs, it is possible that every student in the course has access to one setup, allowing all students to obtain deep insights into nanotechnology and to understand the principles of atomic force microscopy.

  19. Infrared small target detection based on visual attention

    NASA Astrophysics Data System (ADS)

    Chen, Hao; Zhang, Hong; Cheng, Feiyang; Yuan, Ding; Sun, Mingui

    2015-03-01

    Detecting dim and small target in infrared images and videos is one of the most important techniques in many computer vision applications, such as video surveillance and infrared imaging precise guidance. In this paper, we proposed a real-time target detection approach in infrared imagery. This method combined saliency detection technology and local average filtering. First, we compute the log amplitude spectrum of infrared image. Second, we find the spikes of the amplitude spectrum using cubic facet model and suppress the sharp spikes using local average filtering. At last, the detection result in spatial domain is obtained by reconstructing the 2D signal using the original phase and the filtered amplitude spectrum. Experimental results of infrared images with different types of backgrounds demonstrate the high efficiency and accuracy of the proposed method to detect the dim and small targets.

  20. Measuring glacier surface temperatures with ground-based thermal infrared imaging

    NASA Astrophysics Data System (ADS)

    Aubry-Wake, Caroline; Baraer, Michel; McKenzie, Jeffrey M.; Mark, Bryan G.; Wigmore, Oliver; Hellström, Robert È.; Lautz, Laura; Somers, Lauren

    2015-10-01

    Spatially distributed surface temperature is an important, yet difficult to observe, variable for physical glacier melt models. We utilize ground-based thermal infrared imagery to obtain spatially distributed surface temperature data for alpine glaciers. The infrared images are used to investigate thermal microscale processes at the glacier surface, such as the effect of surface cover type and the temperature gradient at the glacier margins on the glacier's temperature dynamics. Infrared images were collected at Cuchillacocha Glacier, Cordillera Blanca, Peru, on 23-25 June 2014. The infrared images were corrected based on ground truth points and local meteorological data. For the control points, the Pearson's correlation coefficient between infrared and station temperatures was 0.95. The ground-based infrared camera has the potential for greatly improving glacier energy budget studies, and our research shows that it is critical to properly correct the thermal images to produce robust, quantifiable data.

  1. LED-based near infrared sensor for cancer diagnostics

    NASA Astrophysics Data System (ADS)

    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.

  2. Detail enhancement of blurred infrared images based on frequency extrapolation

    NASA Astrophysics Data System (ADS)

    Xu, Fuyuan; Zeng, Deguo; Zhang, Jun; Zheng, Ziyang; Wei, Fei; Wang, Tiedan

    2016-05-01

    A novel algorithm for enhancing the details of the blurred infrared images based on frequency extrapolation has been raised in this paper. Unlike other researchers' work, this algorithm mainly focuses on how to predict the higher frequency information based on the Laplacian pyramid separation of the blurred image. This algorithm uses the first level of the high frequency component of the pyramid of the blurred image to reverse-generate a higher, non-existing frequency component, and adds back to the histogram equalized input blurred image. A simple nonlinear operator is used to analyze the extracted first level high frequency component of the pyramid. Two critical parameters are participated in the calculation known as the clipping parameter C and the scaling parameter S. The detailed analysis of how these two parameters work during the procedure is figure demonstrated in this paper. The blurred image will become clear, and the detail will be enhanced due to the added higher frequency information. This algorithm has the advantages of computational simplicity and great performance, and it can definitely be deployed in the real-time industrial applications. We have done lots of experiments and gave illustrations of the algorithm's performance in this paper to convince its effectiveness.

  3. A nitrogen-vacancy spin based molecular structure microscope using multiplexed projection reconstruction

    NASA Astrophysics Data System (ADS)

    Lazariev, Andrii; Balasubramanian, Gopalakrishnan

    2015-09-01

    Methods and techniques to measure and image beyond the state-of-the-art have always been influential in propelling basic science and technology. Because current technologies are venturing into nanoscopic and molecular-scale fabrication, atomic-scale measurement techniques are inevitable. One such emerging sensing method uses the spins associated with nitrogen-vacancy (NV) defects in diamond. The uniqueness of this NV sensor is its atomic size and ability to perform precision sensing under ambient conditions conveniently using light and microwaves (MW). These advantages have unique applications in nanoscale sensing and imaging of magnetic fields from nuclear spins in single biomolecules. During the last few years, several encouraging results have emerged towards the realization of an NV spin-based molecular structure microscope. Here, we present a projection-reconstruction method that retrieves the three-dimensional structure of a single molecule from the nuclear spin noise signatures. We validate this method using numerical simulations and reconstruct the structure of a molecular phantom β-cyclodextrin, revealing the characteristic toroidal shape.

  4. Microscopic predictions of fission yields based on the time dependent GCM formalism

    NASA Astrophysics Data System (ADS)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-03-01

    Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization in nuclear energy. The need for a predictive theory applicable where no data is available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. One of the most promising theoretical frameworks is the time-dependent generator coordinate method (TDGCM) applied under the Gaussian overlap approximation (GOA). Previous studies reported promising results by numerically solving the TDGCM+GOA equation with a finite difference technique. However, the computational cost of this method makes it difficult to properly control numerical errors. In addition, it prevents one from performing calculations with more than two collective variables. To overcome these limitations, we developed the new code FELIX-1.0 that solves the TDGCM+GOA equation based on the Galerkin finite element method. In this article, we briefly illustrate the capabilities of the solver FELIX-1.0, in particular its validation for n+239Pu low energy induced fission. This work is the result of a collaboration between CEA,DAM,DIF and LLNL on nuclear fission theory.

  5. Dark-field spectral imaging microscope for localized surface plasmon resonance-based biosensing

    NASA Astrophysics Data System (ADS)

    Yim, Sang-Youp; Park, Jin-Ho; Kim, Min-Gon

    2015-07-01

    Localized surface plasmon resonance (LSPR) of metal nanoparticles makes red-shift of extinction wavelength with an increase in the refractive index at the surface of the metal nanoparticles. Since biomolecules bound to the metal nanoparticle's surface induce refractive index change, biosensing based on LSPR effect can be possible by monitoring scattering or absorption spectrum changes. Generally, however, conventional method detects ensemble averaged LSPR signal of a huge number of metal nanoparticles. Here, we have constructed a dark-field spectral imaging microscope in order to monitor the scattering spectra of individual metal nanoparticles, simultaneously. Gold nanorod (GNR) and aptamer are employed to detect ochratoxin A (OTA) related to a carcinogenic illness. An aptamer-target binding mechanism promotes wavelength shift of extinction spectra due to refractive index change within sensing volume of GNR by structural change of aptamer. A number of GNRs can be identified in a dark-field LSPR image, simultaneously. A typical spectrum of a GNR exhibits red-shift after target binding of molecules and OTA detection is extended to the very low concentration of 1 pM level.

  6. A nitrogen-vacancy spin based molecular structure microscope using multiplexed projection reconstruction

    PubMed Central

    Lazariev, Andrii; Balasubramanian, Gopalakrishnan

    2015-01-01

    Methods and techniques to measure and image beyond the state-of-the-art have always been influential in propelling basic science and technology. Because current technologies are venturing into nanoscopic and molecular-scale fabrication, atomic-scale measurement techniques are inevitable. One such emerging sensing method uses the spins associated with nitrogen-vacancy (NV) defects in diamond. The uniqueness of this NV sensor is its atomic size and ability to perform precision sensing under ambient conditions conveniently using light and microwaves (MW). These advantages have unique applications in nanoscale sensing and imaging of magnetic fields from nuclear spins in single biomolecules. During the last few years, several encouraging results have emerged towards the realization of an NV spin-based molecular structure microscope. Here, we present a projection-reconstruction method that retrieves the three-dimensional structure of a single molecule from the nuclear spin noise signatures. We validate this method using numerical simulations and reconstruct the structure of a molecular phantom β-cyclodextrin, revealing the characteristic toroidal shape. PMID:26370514

  7. Fabrication of large scale nanostructures based on a modified atomic force microscope nanomechanical machining system.

    PubMed

    Hu, Z J; Yan, Y D; Zhao, X S; Gao, D W; Wei, Y Y; Wang, J H

    2011-12-01

    The atomic force microscope (AFM) tip-based nanomechanical machining has been demonstrated to be a powerful tool for fabricating complex 2D∕3D nanostructures. But the machining scale is very small, which holds back this technique severely. How to enlarge the machining scale is always a major concern for the researches. In the present study, a modified AFM tip-based nanomechanical machining system is established through combination of a high precision X-Y stage with the moving range of 100 mm × 100 mm and a commercial AFM in order to enlarge the machining scale. It is found that the tracing property of the AFM system is feasible for large scale machining by controlling the constant normal load. Effects of the machining parameters including the machining direction and the tip geometry on the uniform machined depth with a large scale are evaluated. Consequently, a new tip trace and an increasing load scheme are presented to achieve a uniform machined depth. Finally, a polymer nanoline array with the dimensions of 1 mm × 0.7 mm, the line density of 1000 lines/mm and the average machined depth of 150 nm, and a 20 × 20 polymer square holes array with the scale of 380 μm × 380 μm and the average machined depth of 250 nm are machined successfully. The uniform of the machined depths for all the nanostructures is acceptable. Therefore, it is verified that the AFM tip-based nanomechanical machining method can be used to machine millimeter scale nanostructures.

  8. Automated, highly reproducible, wide-field, light-based cortical mapping method using a commercial stereo microscope and its applications

    PubMed Central

    Jiang, Su; Liu, Ya-Feng; Wang, Xiao-Min; Liu, Ke-Fei; Zhang, Ding-Hong; Li, Yi-Ding; Yu, Ai-Ping; Zhang, Xiao-Hui; Zhang, Jia-Yi; Xu, Jian-Guang; Gu, Yu-Dong; Xu, Wen-Dong; Zeng, Shao-Qun

    2016-01-01

    We introduce a more flexible optogenetics-based mapping system attached on a stereo microscope, which offers automatic light stimulation to individual regions of interest in the cortex that expresses light-activated channelrhodopsin-2 in vivo. Combining simultaneous recording of electromyography from specific forelimb muscles, we demonstrate that this system offers much better efficiency and precision in mapping distinct domains for controlling limb muscles in the mouse motor cortex. Furthermore, the compact and modular design of the system also yields a simple and flexible implementation to different commercial stereo microscopes, and thus could be widely used among laboratories.

  9. Automated, highly reproducible, wide-field, light-based cortical mapping method using a commercial stereo microscope and its applications

    PubMed Central

    Jiang, Su; Liu, Ya-Feng; Wang, Xiao-Min; Liu, Ke-Fei; Zhang, Ding-Hong; Li, Yi-Ding; Yu, Ai-Ping; Zhang, Xiao-Hui; Zhang, Jia-Yi; Xu, Jian-Guang; Gu, Yu-Dong; Xu, Wen-Dong; Zeng, Shao-Qun

    2016-01-01

    We introduce a more flexible optogenetics-based mapping system attached on a stereo microscope, which offers automatic light stimulation to individual regions of interest in the cortex that expresses light-activated channelrhodopsin-2 in vivo. Combining simultaneous recording of electromyography from specific forelimb muscles, we demonstrate that this system offers much better efficiency and precision in mapping distinct domains for controlling limb muscles in the mouse motor cortex. Furthermore, the compact and modular design of the system also yields a simple and flexible implementation to different commercial stereo microscopes, and thus could be widely used among laboratories. PMID:27699114

  10. Infrared repair brazing of 403 stainless steel with a nickel-based braze alloy

    NASA Astrophysics Data System (ADS)

    Shiue, R. K.; Wu, S. K.; Hung, C. M.

    2002-06-01

    Martensitic stainless steel (403SS) is extensively used for intermediate and low-pressure steam turbine blades in fossil-fuel power plants. The purpose of this investigation is to study the repair of shallow cracks on the surface of 403SS steam turbine blades by infrared repair brazing using rapid thermal cycles. A nickel-based braze alloy (NICROBRAZ LM) is used as filler metal. The braze alloy after brazing is primarily comprised of borides and an FeNi3 matrix with different amounts of alloying elements, especially B and Si. As the brazing temperature increases, more Fe atoms are dissolved into the molten braze. Some boron atoms diffuse into the 403SS substrate primarily via grain boundary diffusion and form B-Cr-Fe intermetallic precipitates along the grain boundaries. The LM filler metal demonstrates better performance than 403SS in both microhardness and wear tests. It is also noted that specimens brazed in a vacuum have less porosity than those brazed in an Ar atmosphere. The shear strength of the joint is around 300 MPa except for specimens brazed in short time periods, e.g., 5 seconds in Ar flow and 30 seconds in vacuum. The fractographs mainly consist of brittle fractures and no ductile dimple fractures observed in the scanning electron microscope (SEM) examination.

  11. Industrial applications of accelerator-based infrared sources: Analysis using infrared microspectroscopy

    SciTech Connect

    Bantignies, J.L.; Fuchs, G.; Wilhelm, C.; Carr, G.L.; Dumas, P.

    1997-09-01

    Infrared Microspectroscopy, using a globar source, is now widely employed in the industrial environment, for the analysis of various materials. Since synchrotron radiation is a much brighter source, an enhancement of an order of magnitude in lateral resolution can be achieved. Thus, the combination of IR microspectroscopy and synchrotron radiation provides a powerful tool enabling sample regions only few microns size to be studied. This opens up the potential for analyzing small particles. Some examples for hair, bitumen and polymer are presented.

  12. Automatic target recognition algorithm based on statistical dispersion of infrared multispectral image

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Cao, Le-lin; Wu, Chun-feng; Hou, Qing-yu

    2009-07-01

    A novel automatic target recognition algorithm based on statistical dispersion of infrared multispectral images(SDOIMI) is proposed. Firstly, infrared multispectral characteristic matrix of the scenario is constructed based on infrared multispectral characteristic information (such as radiation intensity and spectral distribution etc.) of targets, background and decoys. Then the infrared multispectral characteristic matrix of targets is reconstructed after segmenting image by maximum distance method and fusing spatial and spectral information. Finally, an statistical dispersion of infrared multispectral images(SDOIMI) recognition criteria is formulated in terms of spectral radiation difference of interesting targets. In simulation, nine sub-bands multispectral images of real ship target and shipborne aerosol infrared decoy modulated by laser simulating ship geometry appearance are obtained via using spectral radiation curves. Digital simulation experiment result verifies that the algorithm is effective and feasible.

  13. Infrared face recognition based on binary particle swarm optimization and SVM-wrapper model

    NASA Astrophysics Data System (ADS)

    Xie, Zhihua; Liu, Guodong

    2015-10-01

    Infrared facial imaging, being light- independent, and not vulnerable to facial skin, expressions and posture, can avoid or limit the drawbacks of face recognition in visible light. Robust feature selection and representation is a key issue for infrared face recognition research. This paper proposes a novel infrared face recognition method based on local binary pattern (LBP). LBP can improve the robust of infrared face recognition under different environment situations. How to make full use of the discriminant ability in LBP patterns is an important problem. A search algorithm combination binary particle swarm with SVM is used to find out the best discriminative subset in LBP features. Experimental results show that the proposed method outperforms traditional LBP based infrared face recognition methods. It can significantly improve the recognition performance of infrared face recognition.

  14. Autonomous infrared-based guidance system for approach and landing

    NASA Astrophysics Data System (ADS)

    Doehler, Hans-Ullrich; Korn, Bernd R.

    2004-08-01

    This contribution summarizes DLR's recent development of a considerable robust and reliable method to estimate the relative position of an aircraft with respect to a runway based on camera images only (TV, infrared or even PMMW radar). The special advantage of the proposed method is, that neither a calibrated camera (referring to focus length and mounting angles relative to the aircraft) is required, nor any knowledge of special points of the runway (3-D world coordinates and their 2-D identification within the image) is needed. The only reference to the 3-D world, which has to be known, is the width of the runway stripe. The proposed algorithm computes the relative height of the aircraft above the runway stripe and the lateral deviation from the centre line of the runway as well. Additionally, several image analysis procedures are presented which allow to detect the runway stripe by either grouping the asphalt/grass border lines, or by analyzing the alignment structure of runway lights. The proposed image analysis method fulfills real-time requirements and has been tested with several image sequences acquired with different types of IR-cameras.

  15. MEMS-based infrared detector for body thermometer

    NASA Astrophysics Data System (ADS)

    Yoo, Kum-Pyo; Kim, Yun-Ho; Min, Nam-Ki

    2005-12-01

    Infrared detectors have many application fields. One of those, MEMS based thermopile is attractive for many low-cost commercial and industrial applications, mainly because it does not require cooling for operation and the process technologies are relatively simple. The MEMS thermopile fabricated on a silicon nitride microbridge structure was proposed. Using microbridge rather conventional membrane makes it possible to fabricate much smaller micro thermopile and to reduce heat loss because of small contact area at silicon rim. The bridge material is only composed of Si3N4. The thermocouple was used a poly-Si and an aluminum. The characteristic of electromotive force (EMF) generation was evaluated for various patterns at hot junction. Aluminum thermocouple shape on bridge structure was designed two patterns. One was a square shape and the other shape was a hollow square. The output voltage of hollow square-type electrode was increased in compared with square-type electrode from 3.03uV/°C to 4.609uV/°C at body temperature (37°C). With the same membrane dimensions and the same overall thickness of the chip a thermopile on microbridge is almost 53% smaller a conventional thermopile chip.

  16. Near infrared spectroscopy based brain-computer interface

    NASA Astrophysics Data System (ADS)

    Ranganatha, Sitaram; Hoshi, Yoko; Guan, Cuntai

    2005-04-01

    A brain-computer interface (BCI) provides users with an alternative output channel other than the normal output path of the brain. BCI is being given much attention recently as an alternate mode of communication and control for the disabled, such as patients suffering from Amyotrophic Lateral Sclerosis (ALS) or "locked-in". BCI may also find applications in military, education and entertainment. Most of the existing BCI systems which rely on the brain's electrical activity use scalp EEG signals. The scalp EEG is an inherently noisy and non-linear signal. The signal is detrimentally affected by various artifacts such as the EOG, EMG, ECG and so forth. EEG is cumbersome to use in practice, because of the need for applying conductive gel, and the need for the subject to be immobile. There is an urgent need for a more accessible interface that uses a more direct measure of cognitive function to control an output device. The optical response of Near Infrared Spectroscopy (NIRS) denoting brain activation can be used as an alternative to electrical signals, with the intention of developing a more practical and user-friendly BCI. In this paper, a new method of brain-computer interface (BCI) based on NIRS is proposed. Preliminary results of our experiments towards developing this system are reported.

  17. [An ear thermometer based on infrared thermopiles sensor].

    PubMed

    Xie, Haiyuan; Qian, Mingli

    2013-09-01

    According to the development of body temperature measurement mode, an ear thermometer with infrared thermopiles sensor is designed for body thermometry Compared with oral thermometer, the accuracy of ear thermometer is acceptable.

  18. (abstract) Infrared Cirrus and Future Space Based Astronomy

    NASA Technical Reports Server (NTRS)

    Gautier, T. N.

    1993-01-01

    A review of the known properties of the distribution of infrared cirrus is followed by a discussion of the implications of cirrus on observations from space. Probable limitations on space observations due to IR cirrus.

  19. Infrared target tracking with kernel-based performance metric and eigenvalue-based similarity measure

    NASA Astrophysics Data System (ADS)

    Ling, Jianguo; Liu, Erqi; Liang, Haiyan; Yang, Jie

    2007-06-01

    An infrared target tracking framework is presented that consists of three main parts: mean shift tracking, its tracking performance evaluation, and position correction. The mean shift tracking algorithm, which is a widely used kernel-based method, has been developed for the initial tracking for its efficiency and effectiveness. A performance evaluation module is applied for the online evaluation of its tracking performance with a kernel- based metric to unify the tracking and performance metric within a kernel-based tracking framework. Then the tracking performance evaluation result is input into a controller in which a decision is made whether to trigger a position correction process. The position correction module employs a matching method with a new eigenvalue-based similarity measure computed from a local complexity degree weighted covariance matrix. Experimental results on real-life infrared image sequences are presented to demonstrate the efficacy of the proposed method.

  20. ASR potential of quartz based on expansion values and microscopic characteristics of mortar bars

    NASA Astrophysics Data System (ADS)

    Stastna, Aneta; Sachlova, Sarka; Kuchynova, Marketa; Pertold, Zdenek; Prikryl, Richard

    2016-04-01

    The alkali-silica reaction (ASR) is one of the most damaging factors for concrete structures. Different analytical techniques are used to quantify ASR potential of aggregates. The accelerated mortar bar test (ASTM C1260) in combination with the petrographic examination of aggregates by microscopic techniques belongs to the frequently employed methods. Such a methodical approach enables quantification of the ASR potential, based on the expansion values of accelerated mortar bars; and also to identify deleterious components in aggregates. In this study, the accelerated mortar bar test (ASTM C1260) was modified and combined with the scanning electron microscopy of polished sections prepared from mortar bars. The standard 14-day test period of mortar bars was prolonged to 1-year. ASR potential of aggregates was assessed based on expansion values (both 14-day and 1-year) of mortar bars and microscopic analysis of ASR products (alkali silica gels, microcracks, dissolution gaps) detected in the sections. Different varieties of quartz-rich rocks including chert, quartz meta-greywacke, three types of quartzite and pegmatite were used as aggregate. Only quartz from pegmatite was assessed to be non reactive (14-day expansion of 0.08%, 1-year expansion of 1.25%). Aggregate sections exhibited minor ASR products even after 1-year of mortar bar immersion in 1 M NaOH. Expansion values of the rest of samples exceeded the limit of 0.10% after 14-day test period indicating aggregates as reactive. The highest ASR potential was detected in mortar bars containing chert (14-day expansion of 0.55%, 1-year expansion of 2.70%) and quartz meta-greywacke (14-day expansion of 0.46%, 1-year expansion of 2.41%). The high ASR potential was explained by presence of cryptocrystalline matrix in significant volumes (24 - 65 vol%). Influence of the lengths of the immersion in the alkaline solution was observed mainly in the microstructure of the cement paste and on the extension of ASR products. The

  1. Key to Freshwater Algae: A Web-based Tool to Enhance Understanding of Microscopic Biodiversity

    NASA Astrophysics Data System (ADS)

    Shayler, Hannah A.; Siver, Peter A.

    2006-10-01

    The Freshwater Ecology Laboratory at Connecticut College has developed an interactive, Web-based identification key to freshwater algal genera using the Lucid Professional and Lucid 3 software developed by the Centre for Biological Information Technology at the University of Queensland, Brisbane, Australia. The Key to Freshwater Algae was funded by the National Science Foundation (Award #CCLI-0229531) to encourage awareness of microscopic diversity through a creative, investigative approach to learning. Users may answer questions in any order to quickly and efficiently narrow down the list of taxa to only those that match the characteristics they have chosen. All characters and terms are clearly explained for ease of use by those unfamiliar with the algae. This non-hierarchical, user-friendly key is linked to Web pages containing a wealth of resources, including images, movies, and information about the morphology, ecology, and reproduction of each organism. These materials are especially well suited for classroom use in conjunction with cultures purchased from the Carolina Biological Supply Company, a popular distributor of biological materials. Cultures from the Carolina Biological Supply Company representing nearly 75 freshwater genera from a variety of algal groups were observed and photographed using high resolution digital imaging to fully document cellular structure and highlight distinguishing features. High quality video footage of each taxon incorporating titles, diagrams, and structural terminology was outputted as QuickTime movies, on DVD, and on VHS cassettes. The Key to Freshwater Algae and supplemental materials are available online at http://silicasecchidisk.conncoll.edu to provide an innovative alternative to traditional dichotomous keys that is particularly appropriate for introducing students in undergraduate life science courses to the algal groups and genera.

  2. High-stability cryogenic scanning tunneling microscope based on a closed-cycle cryostat

    SciTech Connect

    Hackley, Jason D.; Kislitsyn, Dmitry A.; Beaman, Daniel K.; Nazin, George V.; Ulrich, Stefan

    2014-10-15

    We report on the design and operation of a cryogenic ultra-high vacuum (UHV) scanning tunneling microscope (STM) coupled to a closed-cycle cryostat (CCC). The STM is thermally linked to the CCC through helium exchange gas confined inside a volume enclosed by highly flexible rubber bellows. The STM is thus mechanically decoupled from the CCC, which results in a significant reduction of the mechanical noise transferred from the CCC to the STM. Noise analysis of the tunneling current shows current fluctuations up to 4% of the total current, which translates into tip-sample distance variations of up to 1.5 picometers. This noise level is sufficiently low for atomic-resolution imaging of a wide variety of surfaces. To demonstrate this, atomic-resolution images of Au(111) and NaCl(100)/Au(111) surfaces, as well as of carbon nanotubes deposited on Au(111), were obtained. Thermal drift analysis showed that under optimized conditions, the lateral stability of the STM scanner can be as low as 0.18 Å/h. Scanning Tunneling Spectroscopy measurements based on the lock-in technique were also carried out, and showed no detectable presence of noise from the closed-cycle cryostat. Using this cooling approach, temperatures as low as 16 K at the STM scanner have been achieved, with the complete cool-down of the system typically taking up to 12 h. These results demonstrate that the constructed CCC-coupled STM is a highly stable instrument capable of highly detailed spectroscopic investigations of materials and surfaces at the atomic scale.

  3. Observation of the potential distribution in GaN-based devices by a scanning electron microscope.

    PubMed

    Karumi, Takahiro; Tanaka, Shigeyasu; Tanji, Takayoshi

    2014-11-01

    Mapping of the potential distribution using a scanning electron microscope (SEM) has been reported in recent years [1,2] for semiconductors such as Si, GaAs and InP. But, there are no such studies on GaN-based devices, to our knowledge. In this study, we observed two types of GaN-based devices by SEM to see if there is a condition that the contrast matches the potential distribution of the devices. The first device we studied was GaN p-n junction (p, n ∼5 × 10(17) cm(-3)). The device was cut, and polished from the cross-section to a flat surface. The cross-section was observed by SEM. Fig. 1(a) shows an SEM image taken at 3 kV. The p-region appears bright and the n-region appears dark. The image intensity changes at the position of p-n junction, for which we used electron beam induced current (EBIC) technique to determine the p-n junction position. Fig. 1(b) is a line profile across the p-n junction (broken line) of the SEM image together with a calculated potential distribution (solid line) using p and n concentrations. It can be seen that the contrast profile matches the potential distribution very well. The SEM observations were carried out for several accelerating voltages. But, best result was obtained at 3 kV. For lower accelerating voltages, the image seemed to reflect the surface potential. On the other hand, higher accelerating voltages resulted in blurred images. The second sample was a light emitting diode structure based on AlN where a multiple quantum well (MQW) structure was sandwiched by p- and n-AlGaN materials. In this case, the sample was obliquely polished from the surface (∼10°) to improve the lateral resolution. The SEM image could reveal the structure of MQW.jmicro;63/suppl_1/i22/DFU051F1F1DFU051F1Fig. 1.(a) SEM image of p-n GaN. (b) Comparison of line profile across the p-n junction (broken line) and a calculated potential distribution (solid line). AcknowledgementWe thank professor H. Amano (Nagoya University) for providing the

  4. The method of infrared image simulation based on the measured image

    NASA Astrophysics Data System (ADS)

    Lou, Shuli; Liu, Liang; Ren, Jiancun

    2015-10-01

    The development of infrared imaging guidance technology has promoted the research of infrared imaging simulation technology and the key of infrared imaging simulation is the generation of IR image. The generation of IR image is worthful in military and economy. In order to solve the problem of credibility and economy of infrared scene generation, a method of infrared scene generation based on the measured image is proposed. Through researching on optical properties of ship-target and sea background, ship-target images with various gestures are extracted from recorded images based on digital image processing technology. The ship-target image is zoomed in and out to simulate the relative motion between the viewpoint and the target according to field of view and the distance between the target and the sensor. The gray scale of ship-target image is adjusted to simulate the radiation change of the ship-target according to the distance between the viewpoint and the target and the atmospheric transmission. Frames of recorded infrared images without target are interpolated to simulate high frame rate of missile. Processed ship-target images and sea-background infrared images are synthetized to obtain infrared scenes according to different viewpoints. Experiments proved that this method is flexible and applicable, and the fidelity and the reliability of synthesis infrared images can be guaranteed.

  5. Infrared super-resolution imaging method based on retina micro-motion

    NASA Astrophysics Data System (ADS)

    Sui, Xiubao; Gao, Hang; Sun, Yicheng; Chen, Qian; Gu, Guohua

    2013-09-01

    With the wide application of infrared focal plane arrays (IRFPA), military, aerospace, public security and other applications have higher and higher requirements on the spatial resolution of infrared images. However, traditional super-resolution imaging methods have increasingly unable to meet this requirement in technology. In this paper, we adopt the achievement that the human retina micro-motion is the important reason why the human has the hyperacuity ability. Based on the achievement, we bring forward an infrared super-resolution imaging method based on retina micro-motion. In the method, we use the piezoelectric ceramic equipment to control the infrared detector moving variably within a plane parallel to the focal plane. The motion direction is toward each other into a direction of 90°. In the four directions of the movement, we get four sub-images and generate a high spatial resolution infrared image by image interpolation method. In the process of the shifting movement of the detector, we set the threshold of the detector response and record the response time difference when adjacent pixel responses are up to the threshold. By the method, we get the object's edges, enhance them in the high resolution infrared image and get the super-resolution infrared image. The experimental results show that our proposed super-resolution imaging methods can improve the spatial resolution of the infrared image effectively. The method will offer a new idea for the super-resolution reconstruction of infrared images.

  6. Biomimetic infrared sensors based on the infrared receptors of pyrophilous insects

    NASA Astrophysics Data System (ADS)

    Schmitz, Helmut; Kahl, Thilo; Soltner, Helmut; Bousack, Herbert

    2011-04-01

    Beetles of the genus Melanophila and certain flat bugs of the genus Aradus approach forest fires. For the detection of fires and of hot surfaces the pyrophilous species of both genera have developed infrared (IR) receptors, which have developed from common hair mechanoreceptors. Thus this type of insect IR receptor has been termed photomechanic and shows the following two special features: (i) the formation of a complex cuticular sphere consisting of an outer exocuticular shell as well as of a cavernous microfluidic core. (ii) The enclosure of the dendritic tip of a mechanosensitive neuron inside the core in a liquid-filled chamber. Most probably a photomechanic IR sensillum acts as a microfluidic converter of infrared radiation into an increase in internal pressure inside the sphere, which is measured by a mechanosensitive neuron. A simple model for this biological IR sensor is the Golay sensor, which is filled with a liquid instead of gas. Here the absorbed IR radiation results in a pressure increase of the liquid and the deflection of a thin membrane. For the evaluation of this model analytical formulas are presented, which permits the calculation of the pressure increase in the cavity, the deformation of the membrane and the time constant of an artificial leak to compensate ambient temperature changes. Some organic liquids with high thermal expansion coefficients may improve the deflection of the membrane compared to water.

  7. Research and experiment of InGaAs shortwave infrared imaging system based on FPGA

    NASA Astrophysics Data System (ADS)

    Ren, Ling; Min, Chaobo; Sun, Jianning; Gu, Yan; Yang, Feng; Zhu, Bo; Pan, Jingsheng; Guo, Yiliang

    2015-04-01

    The design and imaging characteristic experiment of InGaAs shortwave infrared imaging system are introduced. Through the adoption of InGaAs focal plane array, the real time image process structure of InGaAs shortwave infrared imaging system is researched. The hardware circuit and image process software of the imaging system based on FPGA are researched. The InGaAs shortwave infrared imaging system is composed of shortwave infrared lens, InGaAs focal plane array, temperature controller module, power supply module, analog-to-digital converter module, digital-to-analog converter module, FPGA image processing module and optical-mechanical structure. The main lock frequency of InGaAs shortwave infrared imaging system is 30MHz. The output mode of the InGaAs shortwave infrared imaging system is PAL analog signal. The power dissipation of the imaging system is 2.6W. The real time signal process in InGaAs shortwave infrared imaging system includes non-uniformly correction algorithm, bad pixel replacement algorithm, and histogram equalization algorithm. Based on the InGaAs shortwave infrared imaging system, the imaging characteristic test of shortwave infrared is carried out for different targets in different conditions. In the foggy weather, the haze and fog penetration are tested. The InGaAs shortwave infrared imaging system could be used for observing humans, boats, architecture, and mountains in the haze and foggy weather. The configuration and performance of InGaAs shortwave infrared imaging system are respectively logical and steady. The research on the InGaAs shortwave infrared imaging system is worthwhile for improving the development of night vision technology.

  8. rFRET: A comprehensive, Matlab-based program for analyzing intensity-based ratiometric microscopic FRET experiments.

    PubMed

    Nagy, Peter; Szabó, Ágnes; Váradi, Tímea; Kovács, Tamás; Batta, Gyula; Szöllősi, János

    2016-04-01

    Fluorescence or Förster resonance energy transfer (FRET) remains one of the most widely used methods for assessing protein clustering and conformation. Although it is a method with solid physical foundations, many applications of FRET fall short of providing quantitative results due to inappropriate calibration and controls. This shortcoming is especially valid for microscopy where currently available tools have limited or no capability at all to display parameter distributions or to perform gating. Since users of multiparameter flow cytometry usually apply these tools, the absence of these features in applications developed for microscopic FRET analysis is a significant limitation. Therefore, we developed a graphical user interface-controlled Matlab application for the evaluation of ratiometric, intensity-based microscopic FRET measurements. The program can calculate all the necessary overspill and spectroscopic correction factors and the FRET efficiency and it displays the results on histograms and dot plots. Gating on plots and mask images can be used to limit the calculation to certain parts of the image. It is an important feature of the program that the calculated parameters can be determined by regression methods, maximum likelihood estimation (MLE) and from summed intensities in addition to pixel-by-pixel evaluation. The confidence interval of calculated parameters can be estimated using parameter simulations if the approximate average number of detected photons is known. The program is not only user-friendly, but it provides rich output, it gives the user freedom to choose from different calculation modes and it gives insight into the reliability and distribution of the calculated parameters. © 2016 International Society for Advancement of Cytometry.

  9. Thermal Infrared Imaging-Based Computational Psychophysiology for Psychometrics.

    PubMed

    Cardone, Daniela; Pinti, Paola; Merla, Arcangelo

    2015-01-01

    Thermal infrared imaging has been proposed as a potential system for the computational assessment of human autonomic nervous activity and psychophysiological states in a contactless and noninvasive way. Through bioheat modeling of facial thermal imagery, several vital signs can be extracted, including localized blood perfusion, cardiac pulse, breath rate, and sudomotor response, since all these parameters impact the cutaneous temperature. The obtained physiological information could then be used to draw inferences about a variety of psychophysiological or affective states, as proved by the increasing number of psychophysiological studies using thermal infrared imaging. This paper presents therefore a review of the principal achievements of thermal infrared imaging in computational physiology with regard to its capability of monitoring psychophysiological activity.

  10. Thermal Infrared Imaging-Based Computational Psychophysiology for Psychometrics.

    PubMed

    Cardone, Daniela; Pinti, Paola; Merla, Arcangelo

    2015-01-01

    Thermal infrared imaging has been proposed as a potential system for the computational assessment of human autonomic nervous activity and psychophysiological states in a contactless and noninvasive way. Through bioheat modeling of facial thermal imagery, several vital signs can be extracted, including localized blood perfusion, cardiac pulse, breath rate, and sudomotor response, since all these parameters impact the cutaneous temperature. The obtained physiological information could then be used to draw inferences about a variety of psychophysiological or affective states, as proved by the increasing number of psychophysiological studies using thermal infrared imaging. This paper presents therefore a review of the principal achievements of thermal infrared imaging in computational physiology with regard to its capability of monitoring psychophysiological activity. PMID:26339284

  11. The maxillary molar endodontic access opening: A microscope-based approach

    PubMed Central

    Mamoun, John Sami

    2016-01-01

    This article reviews the basic clinical techniques of performing a maxillary molar endodontic access opening, starting from the initial access opening into the pulp chamber, to the point where a size #10 file has been advanced to the apices of all three or four (or more) canals. The article explains how the use of the dental surgical operating microscope or microscope-level loupes magnification of ×6–8 or greater, combined with head-mounted or coaxial illumination, improve the ability of a dentist to identify microscopic root canal orifices, which facilitates the efficient creation of conservative access openings with adequate straight-line access in maxillary molars. Magnified photos illustrate various microscopic anatomical structures or landmarks of the initial access opening. Techniques are explored for implementing an access opening for teeth with vital versus necrotic pulpal tissues. The article also explores the use of piezoelectric or ultrasonic instruments for revealing root canal orifices and for removing pulp stones or calcified pulpal tissue inside the pulp chamber. PMID:27403069

  12. The maxillary molar endodontic access opening: A microscope-based approach.

    PubMed

    Mamoun, John Sami

    2016-01-01

    This article reviews the basic clinical techniques of performing a maxillary molar endodontic access opening, starting from the initial access opening into the pulp chamber, to the point where a size #10 file has been advanced to the apices of all three or four (or more) canals. The article explains how the use of the dental surgical operating microscope or microscope-level loupes magnification of ×6-8 or greater, combined with head-mounted or coaxial illumination, improve the ability of a dentist to identify microscopic root canal orifices, which facilitates the efficient creation of conservative access openings with adequate straight-line access in maxillary molars. Magnified photos illustrate various microscopic anatomical structures or landmarks of the initial access opening. Techniques are explored for implementing an access opening for teeth with vital versus necrotic pulpal tissues. The article also explores the use of piezoelectric or ultrasonic instruments for revealing root canal orifices and for removing pulp stones or calcified pulpal tissue inside the pulp chamber. PMID:27403069

  13. Multiple pinhole collimator based microscopic x-ray luminescence computed tomography

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Zhu, Dianwen; Li, Changqing

    2016-03-01

    X-ray luminescence computed tomography (XLCT) is a new hybrid imaging modality, which has the capability to improve optical spatial resolution to hundreds of micrometers for deep targets. In this paper, we report a multiple pinhole collimator based microscopic X-ray luminescence computed tomography (microXLCT) system for small animal imaging. Superfine collimated X-ray pencil beams are used to excite deeply embedded phosphor particles, allowing us to obtain sub-millimeter optical spatial resolution in deep tissues. Multiple collimated X-ray beams are generated by mounting an array of pinholes in the front of a powerful X-ray tube. With multiple X-ray beams scanning, the phosphor particles in the region of the multiple beams are excited simultaneously, which requires less scanning time compared with a single beam scanning. The emitted optical photons on the top surface of the phantom are measured with an electron multiplying charge-coupled device (EMCCD) camera. Meanwhile, an X-ray detector is used to determine the X-ray beam size and position, which are used as structural guidance in the microXLCT image reconstruction. To validate the performance of our proposed multiple pinhole based microXLCT imaging system, we have performed numerical simulations and a phantom experiment. In the numerical simulations, we simulated a cylindrical phantom with two and six embedded targets, respectively. In the simulations, we used four parallel X-ray beams with the beam diameter of 0.1 mm and the beam interval of 3.2 mm. We can reconstruct deeply embedded multiple targets with a target diameter of 0.2 mm using measurements in six projections, which indicated that four parallel X-ray beam scan could reduce scanning time without comprising the reconstructed image quality. In the phantom experiment, we generated two parallel X-ray beams with the beam diameter of 0.5 mm and the beam interval of 4.2 mm. We scanned a phantom of one target with the two parallel X-ray beams. The target was

  14. Synchrotron-based far-infrared spectroscopy of nickel tungstate

    NASA Astrophysics Data System (ADS)

    Kalinko, A.; Kuzmin, A.; Roy, P.; Evarestov, R. A.

    2016-07-01

    Monoclinic antiferromagnetic NiWO4 was studied by far-infrared (30-600 cm-1) absorption spectroscopy in the temperature range of 5-300 K using the synchrotron radiation from SOLEIL source. Two isomorphous CoWO4 and ZnWO4 tungstates were investigated for comparison. The phonon contributions in the far-infrared range of tungstates were interpreted using the first-principles spin-polarized linear combination of atomic orbital calculations. No contributions from magnetic excitations were found in NiWO4 and CoWO4 below their Neel temperatures down to 5 K.

  15. A new method for the characterization of micro-/nano-periodic structures based on microscopic Moiré fringes.

    PubMed

    Wu, Dan; Xie, Huimin; Tang, Minjin; Hu, Zhenxing

    2014-01-01

    Linewidth and opening ratio (ratio of linewidth to period) are important parameters in characterizing micro-/nano-periodic and quasi-periodic structures. Periodic structures are conventionally characterized by the direct observation of specimens under a microscope. However, the field of view is relatively small, and only certain details can be acquired under a microscope. Moreover, the non-uniformity of the linewidth in quasi-periodic structures cannot be detected. This paper proposes a new characterization method for determining the linewidth and opening ratio of periodic structures based on Moiré fringe analysis. This method has the advantage of full-field characterization of the linewidth of micro-/nano-structures over a larger area than that afforded by direct observation. To validate the method, the linewidth of scanning electron microscope (SEM) scan lines was first calibrated with a standard grating. Next, a microperiodic structure with known geometry was characterized using this calibrated SEM system. The results indicate that the proposed method is simple and effective, indicating a potential approach for the characterization of gratings over large areas. This technique can be extended to various high-power scanning microscopes to characterize micro-/nano-structures.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Infrared thermography-based visualization of droplet transport in liquid sprays

    NASA Astrophysics Data System (ADS)

    Akafuah, Nelson K.; Salazar, Abraham J.; Saito, Kozo

    2010-05-01

    An infrared thermography-based technique for the characterization and visualization of liquid sprays was developed. The technique was tested on two atomizers: a high-speed rotary bell atomizer and a high volume low pressure air-assisted atomizer. The technique uses an infrared thermography-based measurement in which a uniformly heated background acts as a thermal radiation source, and an infrared camera as the receiver. The infrared energy emitted by the radiation source in traveling through the spray is attenuated by the presence of the droplets inside the spray. The infrared intensity is captured by the receiver showing the attenuation in the image as a result of the presence of the spray. The captured thermal image is used to study detailed macroscopic features of the spray flow field and the evolution of the paint droplets as they are transferred from the applicator to the target surface.

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

    ERIC Educational Resources Information Center

    Bennett, Jacqueline; Forster, Tabetha

    2010-01-01

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

  19. Microscopic Polyangiitis

    MedlinePlus

    ... include purplish bumps and spots pictured below (palpable purpura). These areas range in size from several millimeters ... Syndrome (EGPA) Cryoglobulinemia Giant Cell Arteritis Henoch-Schönlein Purpura Microscopic Polyangiitis Polyarteritis Nodosa Rheumatoid Vasculitis Takayasu’s Arteritis ...

  20. Fluorescence microscopy imaging with a Fresnel zone plate array based optofluidic microscope

    PubMed Central

    Han, Chao; Lee, Lap Man; Yang, Changhuei

    2013-01-01

    We report the implementation of an on-chip microscope system, termed fluorescence optofluidic microscope (FOFM), which is capable of fluorescence microscopy imaging of samples in fluid media. The FOFM employs an array of Fresnel zone plates (FZP) to generate an array of focused light spots within a microfluidic channel. As a sample flows through the channel and across the array of focused light spots, the fluorescence emissions are collected by a filter-coated CMOS sensor, which serves as the channel's floor. The collected data can then be processed to render fluorescence microscopy images at a resolution determined by the focused light spot size (experimentally measured as 0.65 μm FWHM). In our experiments, our established resolution was 1.0 μm due to Nyquist criterion consideration. As a demonstration, we show that such a system can be used to image the cell nuclei stained by Acridine Orange and cytoplasm labeled by Qtracker®. PMID:21935556

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

    NASA Astrophysics Data System (ADS)

    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

  2. M3: Microscope-based maskless micropatterning with dry film photoresist

    PubMed Central

    Leigh, Steven Y.; Tattu, Aashay; Mitchell, Joseph S. B.

    2011-01-01

    We present a maskless micropatterning system that utilizes a fluorescence microscope with programmable X-Y stage and dry film photoresist to realize feature sizes in the sub-millimeter range (40–700 μm). The method allows for flexible in-house maskless photolithography without a dedicated microfabrication facility and is well-suited for rapid prototyping of microfluidic channels, scaffold templates for protein/cell patterning or optically-guided cell encapsulation for biomedical applications. PMID:21190086

  3. The Narrow Band AOTF Based Hyperspectral Microscopic Imaging on the Rat Skin Stratum Configuration

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Wang, H.; Huang, J.; Gao, Q.

    2014-08-01

    A noncollinear acousto-optic tunable filter (AOTF) was designed with a comprehensive treatment of the properties of TeO2 as an acoustooptic (A-O) material. The results of optical testing validated that it predicted the performance of the designed AOTF. The bandwidth of the AOTF was very narrow in the visible light range. The high spectral resolution of AOTF was useful in practical applications to the hyperspectral imaging. The experimentally observed spectral pattern of the diffracted light was nearly the same as the theoretical result. The measured tuning relationship between the diffracted central optical wavelength and acoustic frequency was in accordance with the theoretical prediction. It demonstrates the accuracy of our design theory. Furthermore, by selecting the AOTF as the spectroscopic element, a hyperspectral microscopic imaging system was designed. The hyperspectral microscopic images of the rat skin tissue under the different optical center wavelength were acquired. The experimental results indicated that the imaging performance was satisfactory. The stratums of the rat skin can be clearly distinguished. The inner details of the epidermis and the corium can be shown on the hyperspectral microscopic images. Some differences also can be found by the comparison of the hyperspectal images under the different optical wavelengths. The study indicated the applicability and the advantage of our system on biomedicine area.

  4. Microfluidic system based on the digital holography microscope for analysis of motile sperm

    NASA Astrophysics Data System (ADS)

    Di Caprio, G.; Coppola, G.; Grilli, S.; Ferraro, P.; Puglisi, R.; Balduzzi, D.; Galli, A.

    2009-06-01

    Digital holography (DH) has been employed in the retrieval of three dimensional images of bull's sperm heads. The system allows a three dimensional analysis of the sperm morphology by means of a Digital Holographic Microscope (DHM). Microscopic holography measurements are performed by projecting a magnified image of a microscopic hologram plane onto a CCD plane. This could constitute the basis of an alternative method for the zoothecnic industry aimed at the investigation of morphological features and the sorting of the motile sperm cells. Indeed, one of the main advantages of digital holography consists in its full non-invasivity and in the capability of investigating the shape of the sperm cells without altering their characteristics. In particular the proposed technique could be applied to investigate the frequency of aberrant spermatozoa. Until now, in fact, such industrial investigations have been mainly performed by means of specific painting probes: unfortunately this technique dramatically reduces the vitality of the sperm cells and can even cause chromosome aberration, making them useless for the zootechnical applications.

  5. Design of an infrared camera based aircraft detection system for laser guide star installations

    SciTech Connect

    Friedman, H.; Macintosh, B.

    1996-03-05

    There have been incidents in which the irradiance resulting from laser guide stars have temporarily blinded pilots or passengers of aircraft. An aircraft detection system based on passive near infrared cameras (instead of active radar) is described in this report.

  6. AOTF-based near-infrared imaging spectrometer for rapid identification of camouflaged target

    NASA Astrophysics Data System (ADS)

    Gao, Zhifan; Zeng, Libo; Wu, Qiongshui

    2014-11-01

    Acousto-optic tunable filter (AOTF) is a novel device for spectrometer. The electronic tunability qualifies it with the most compelling advantages of higher wavelength scan rate over the conventional spectrometers that are mechanically tuned, and the feature of large angular aperture makes the AOTF particularly suitable in imaging applications. In this research, an AOTF-based near-infrared imaging spectrometer was developed. The spectrometer consists of a TeO2 AOTF module, a near-infrared imaging lens assembly, an AOTF controller, an InGaAs array detector, an image acquisition card, and a PC. A precisely designed optical wedge is placed at the emergent surface of the AOTF to deal with the inherent dispersion of the TeO2 that may degrade the spatial resolution. The direct digital synthesizer (DDS) techniques and the phase locked loop (PLL) techniques are combined for radio frequency (RF) signal synthesis. The PLL is driven by the DDS to take advantage of both their merits of high frequency resolution, high frequency scan rate and strong spurious signals resistance capability. All the functions relating to wavelength scan, image acquisition, processing, storge and display are controlled by the PC. Calibration results indicate that the spectral range is 898~1670 nm, the spectral resolution is 6.8 nm(@1064 nm), the wavelength separation between frames in the spectral image assembly is 1.0 nm, and the processing time of a single image is less than 1 ms if a TV camera with 640×512 detector is incorporated. A prototype device was assembled to test the capability of differentiating samples with similar appearances, and satisfactory results were achieved. By this device, the chemical compositions and the distribution information can be obtained simultaneously. This system has the most advantages of no moving parts, fast wavelength scan and strong vibration resistance. The proposed imaging spectrometer has a significant application prospect in the area of identification of

  7. On the conversion of infrared radiation from fission reactor-based photon engine into parallel beam

    NASA Astrophysics Data System (ADS)

    Gulevich, Andrey V.; Levchenko, Vladislav E.; Loginov, Nicolay I.; Kukharchuk, Oleg F.; Evtodiev, Denis A.; Zrodnikov, Anatoly V.

    2002-01-01

    The efficiency of infrared radiation conversion from photon engine based on fission reactor into parallel photon beam is discussed. Two different ways of doing that are considered. One of them is to use the parabolic mirror to convert of infrared radiation into parallel photon beam. The another one is based on the use of special lattice consisting of numerous light conductors. The experimental facility and some results are described. .

  8. Infrared small target detection technology based on OpenCV

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Huang, Zhijian

    2013-05-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detection are described. These algorithms are traditional two-frame difference method, improved three-frame difference method, background estimate and frame difference fusion method, and building background with neighborhood mean method. On the foundation of above works, an infrared target detection software platform which is developed by OpenCV and MFC is introduced. Three kinds of tracking algorithms are integrated in this software. In order to explain the software clearly, the framework and the function are described in this paper. At last, the experiments are performed for some real-life IR images. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  9. Infrared small target detection technology based on OpenCV

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Huang, Zhijian

    2013-09-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detection are described. These algorithms are traditional two-frame difference method, improved three-frame difference method, background estimate and frame difference fusion method, and building background with neighborhood mean method. On the foundation of above works, an infrared target detection software platform which is developed by OpenCV and MFC is introduced. Three kinds of tracking algorithms are integrated in this software. In order to explain the software clearly, the framework and the function are described in this paper. At last, the experiments are performed for some real-life IR images. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  10. Heat Resistance of Xerophilic Fungi Based on Microscopical Assessment of Spore Survival

    PubMed Central

    Pitt, J. I.; Christian, J. H. B.

    1970-01-01

    An improved viable counting technique was developed to facilitate study of the heat resistance of fungal spores. Spores were heated and subsequently incubated in the same medium. After germination, hyphae and germ tubes were stained with lactofuchsin, and the germinated spores were counted with the aid of a microscope. A number of xerophilic strains were examined, mostly isolates from spoiled highmoisture prunes. Of these, ascospores of Aspergillus chevalieri, A. mangini, and Xeromyces bisporus were the most heat-resistant. A decimal reduction curve obtained for A. chevalieri was specified by a z value of 23 F and an F180 of 2.2 min. PMID:5485080

  11. Optical-disk-based imaging system to be used as an optical microscope

    NASA Astrophysics Data System (ADS)

    Shima, Takayuki; Fujimaki, Makoto; Awazu, Koichi

    2016-07-01

    An optical disk surface is scanned spirally by laser light, as in the case of digital versatile discs, and a reflectance image is formed by rearranging the scanned intensity results. A prototype system is developed for imaging with a rotary encoder equipped to precisely control the disk rotation angle. We measured Escherichia coli dispersed on an optical disk sample surface and successfully obtained an image that is identical to that obtained using an optical microscope. The system is advantageous as an optical sensor for detecting sub-micrometer- to micrometer-order substances on a large-area surface.

  12. Graphene-based Hall Sensors for direct magnetic imaging by using Scanning Hall Probe Microscope

    NASA Astrophysics Data System (ADS)

    Sonusen, Selda; Aksoy, Seda; Dede, Munir; Oral, Ahmet

    2013-03-01

    Graphene has been attracting great interest due to its unique electronic and mechanical properties for both fundamental and experimental studies since 2004. Graphene is a promising material for many applications in high speed electronic and spintronic devices as well as sensors. Its high mobility makes graphene a good candidate for magnetic imaging in Scanning Hall Probe Microscope (SHPM). Hall probes are used to scan the magnetic samples to image magnetic domains in SHPM. In this work, single layer graphene produced by chemical vapor deposition technique is used to fabricate Hall sensors by optical and the e-beam lithography with sizes from 500 nm to a few micrometers. The Hall crosses are characterized by Raman mapping to make sure that they are made of a single layer graphene. The Graphene Hall Sensors noise spectra is measured as a function of different bias currents and carrier concentrations at 300 K, 77 K and 4.24K. The imaging performance of the Hall sensor will be demonstrated at different temperatures by imaging a garnet crystal using a Low Temperature Scanning Hall Probe Microscope (LT-SHPM).

  13. Measuring microscopic evolution processes of complex networks based on empirical data

    NASA Astrophysics Data System (ADS)

    Chi, Liping

    2015-04-01

    Aiming at understanding the microscopic mechanism of complex systems in real world, we perform the measurement that characterizes the evolution properties on two empirical data sets. In the Autonomous Systems Internet data, the network size keeps growing although the system suffers a high rate of node deletion (r = 0.4) and link deletion (q = 0.81). However, the average degree keeps almost unchanged during the whole time range. At each time step the external links attached to a new node are about c = 1.1 and the internal links added between existing nodes are approximately m = 8. For the Scientific Collaboration data, it is a cumulated result of all the authors from 1893 up to the considered year. There is no deletion of nodes and links, r = q = 0. The external and internal links at each time step are c = 1.04 and m = 0, correspondingly. The exponents of degree distribution p(k) ∼ k-γ of these two empirical datasets γdata are in good agreement with that obtained theoretically γtheory. The results indicate that these evolution quantities may provide an insight into capturing the microscopic dynamical processes that govern the network topology.

  14. A MEMS based handheld confocal microscope with Raman spectroscopy for in-vivo skin cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Arrasmith, Christopher L.; Patil, Chetan A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2009-02-01

    Both Confocal Microscopy and Raman Spectroscopy have shown potential for diagnosis and differentiation of cancerous and normal skin. Many current studies utilizing these techniques use large bench-top microscopes, and are not suited for in-vivo diagnosis in a clinical setting. We have developed a microscope which combines confocal reflectance imaging with Raman spectroscopy into a compact handheld probe, allowing images and Raman spectra to be taken in-vivo. The compact design of this handheld unit is largely due to the use of a MEMS mirror which scans the illumination laser light in two dimensions to produce the confocal reflectance image of the skin. An integrated CCD camera provides a large area view of the skin surface which helps to guide the location of the confocal reflectance image area. Using this probe, in-vivo confocal reflectance images and Raman spectra of normal skin have been obtained with axial resolutions of 4 μm for the confocal channel and 10 μm for the Raman channel. This paper presents the instrument design and optical characteristics, including representative in-vivo images and Raman data from normal skin tissue.

  15. a Far Infrared Synchrotron-Based Investigation of 3-OXETANONE

    NASA Astrophysics Data System (ADS)

    Chen, Ziqiu; Wijngaarden, Jennifer Van

    2011-06-01

    The four membered ester ring 3-oxetanone is a precursor for adding oxetane subunits into pharmaceuticals which then block metabolically exposed sites in the bioactive molecule without increasing its lipophilicity. The high resolution (0.00096 cmCm-1) rovibrational spectrum of 3-oxetanone was recorded for the first time using far infrared radiation from the Canadian Light Source (CLS) synchrotron facility coupled to a Bruker IFS125HR FTIR spectrometer. A total of six rotationally-resolved vibrational bands were observed between 360 and 1150 cmCm-1 at room temperature. The assignment of the dense spectrum is currently underway and the progress will be discussed in this talk.

  16. Addressable micropatterning of multiple proteins and cells by microscope projection photolithography based on a protein friendly photoresist.

    PubMed

    Kim, Miju; Choi, Jong-Cheol; Jung, Hong-Ryul; Katz, Joshua S; Kim, Min-Gon; Doh, Junsang

    2010-07-20

    We report a new method for the micropatterning of multiple proteins and cells with micrometer-scale precision. Microscope projection photolithography based on a new protein-friendly photoresist, poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate) (PDMP), was used for the fabrication of multicomponent protein/cell arrays. Microscope projection lithography allows precise registration between multiple patterns as well as facile fabrication of microscale features. Thin films of PDMP became soluble in near-neutral physiological buffer solutions upon UV exposure and exhibited excellent resistance to protein adsorption and cell adhesion. By harnessing advantages in microscope projection photolithography and properties of PDMP thin films, we could successfully fabricate protein arrays composed of multiple proteins. Furthermore, we could extend this method for the patterning of two different types of immune cells for the potential study of immune cell interactions. This technique will in general be useful for protein chip fabrication and high-throughput cell-cell communication study.

  17. Methods of foreign fiber detecting based on PCA analyzing of infrared spectral images

    NASA Astrophysics Data System (ADS)

    Tian, LiXun; Fu, WeiSen; Liu, JieYu; Zhang, HongBo; Pan, Jin; Wang, YaPeng; Tong, Fei

    2014-02-01

    A set of near infrared high resolution spectral imaging system is set up, the infrared absorption properties of raw cotton and colorless foreign are analyzed through the system, and scheme of polypropylene fiber detection based on the near infrared spectral image is proposed; On this basis, reduce dimensions the spectral images through the principal component analysis, further improve the efficiency of colorless foreign detection. The experimental results show that the spectral images after reducing dimensions can be used to detect colorless or light color raw cotton fiber effectively.

  18. The generation of infrared and ultraviolet astronomical data bases and retrieval systems

    NASA Technical Reports Server (NTRS)

    Mead, J. M.

    1985-01-01

    Observations with the Infrared Astronomy Satellite (IRAS) and with the International Ultraviolet Explorer (IUE) satellite have stimulated the need for machine-readable data bases at infrared and ultraviolet wavelengths along with associated software. This paper describes the generation of three such data sets at the Astronomical Data Center (ADC) of the NASA-Goddard Space Flight Center (GSFC): the Catalog of Infrared Observations, the Combined List of Astronomical Sources, and the Bibliographical Index of Objects Observed by IUE 1978-82. The discussion is divided by spectral regime and includes summaries of the data products developed in each category.

  19. A parallel multiple path tracing method based on OptiX for infrared image generation

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Wang, Xia; Liu, Li; Long, Teng; Wu, Zimu

    2015-12-01

    Infrared image generation technology is being widely used in infrared imaging system performance evaluation, battlefield environment simulation and military personnel training, which require a more physically accurate and efficient method for infrared scene simulation. A parallel multiple path tracing method based on OptiX was proposed to solve the problem, which can not only increase computational efficiency compared to serial ray tracing using CPU, but also produce relatively accurate results. First, the flaws of current ray tracing methods in infrared simulation were analyzed and thus a multiple path tracing method based on OptiX was developed. Furthermore, the Monte Carlo integration was employed to solve the radiation transfer equation, in which the importance sampling method was applied to accelerate the integral convergent rate. After that, the framework of the simulation platform and its sensor effects simulation diagram were given. Finally, the results showed that the method could generate relatively accurate radiation images if a precise importance sampling method was available.

  20. Real-time generation of infrared ocean scene based on GPU

    NASA Astrophysics Data System (ADS)

    Jiang, Zhaoyi; Wang, Xun; Lin, Yun; Jin, Jianqiu

    2007-12-01

    Infrared (IR) image synthesis for ocean scene has become more and more important nowadays, especially for remote sensing and military application. Although a number of works present ready-to-use simulations, those techniques cover only a few possible ways of water interacting with the environment. And the detail calculation of ocean temperature is rarely considered by previous investigators. With the advance of programmable features of graphic card, many algorithms previously limited to offline processing have become feasible for real-time usage. In this paper, we propose an efficient algorithm for real-time rendering of infrared ocean scene using the newest features of programmable graphics processors (GPU). It differs from previous works in three aspects: adaptive GPU-based ocean surface tessellation, sophisticated balance equation of thermal balance for ocean surface, and GPU-based rendering for infrared ocean scene. Finally some results of infrared image are shown, which are in good accordance with real images.

  1. [Long optical path gas detection based on MEMS infrared light source].

    PubMed

    Du, Bin-Bin; Zhang, Peng; Gao, Wen-Hong; Shi, Yun-Bo; Zhu, Lin-Quan

    2014-04-01

    According to the requirements of infrared gas sensor for the light source, a broad wavelength, high modulation frequency, low power consumption and small size MEMS infrared light source is chosen as the radiation source, whose performance meets the requirements of infrared sensing system for the light source greatly. However, the infrared light source with the lamberation radiation characteristics is a surface light source, which is still with a large numerical aperture after shaping. It is difficult to increase the detection sensitivity by using a traditional long optical gas cell in a MEMS infrared light source detection system. Based on the dual-wavelength single beam differential detection method, an integrating sphere as the gas cell for long optical path is designed, which is able to realize long optical path for high sensitivity gas detection. The physical dimension is deduced for the equivalent optical path according to the flux conservation principle in the process of light transmission, solving the calculation problem of equivalent optical path of the integrating sphere cell. Using FPGA control chip, the MEMS infrared light source is droved at high frequency modulation and the detector output signal is processed, which makes the external circuit design much simple and flexible. It turns out that 166.7 cm equivalent optical path and the minimum concentration of methane of 0.001 x 10(-6) are achieved by the use of a 5 cm diameter integrating sphere in the research, improving the sensitivity of infrared detection system greatly.

  2. [Long optical path gas detection based on MEMS infrared light source].

    PubMed

    Du, Bin-Bin; Zhang, Peng; Gao, Wen-Hong; Shi, Yun-Bo; Zhu, Lin-Quan

    2014-04-01

    According to the requirements of infrared gas sensor for the light source, a broad wavelength, high modulation frequency, low power consumption and small size MEMS infrared light source is chosen as the radiation source, whose performance meets the requirements of infrared sensing system for the light source greatly. However, the infrared light source with the lamberation radiation characteristics is a surface light source, which is still with a large numerical aperture after shaping. It is difficult to increase the detection sensitivity by using a traditional long optical gas cell in a MEMS infrared light source detection system. Based on the dual-wavelength single beam differential detection method, an integrating sphere as the gas cell for long optical path is designed, which is able to realize long optical path for high sensitivity gas detection. The physical dimension is deduced for the equivalent optical path according to the flux conservation principle in the process of light transmission, solving the calculation problem of equivalent optical path of the integrating sphere cell. Using FPGA control chip, the MEMS infrared light source is droved at high frequency modulation and the detector output signal is processed, which makes the external circuit design much simple and flexible. It turns out that 166.7 cm equivalent optical path and the minimum concentration of methane of 0.001 x 10(-6) are achieved by the use of a 5 cm diameter integrating sphere in the research, improving the sensitivity of infrared detection system greatly. PMID:25007612

  3. Microscopic insights into the NMR relaxation-based protein conformational entropy meter.

    PubMed

    Kasinath, Vignesh; Sharp, Kim A; Wand, A Joshua

    2013-10-01

    Conformational entropy is a potentially important thermodynamic parameter contributing to protein function. Quantitative measures of conformational entropy are necessary for an understanding of its role but have been difficult to obtain. An empirical method that utilizes changes in conformational dynamics as a proxy for changes in conformational entropy has recently been introduced. Here we probe the microscopic origins of the link between conformational dynamics and conformational entropy using molecular dynamics simulations. Simulation of seven proteins gave an excellent correlation with measures of side-chain motion derived from NMR relaxation. The simulations show that the motion of methyl-bearing side chains are sufficiently coupled to that of other side chains to serve as excellent reporters of the overall side-chain conformational entropy. These results tend to validate the use of experimentally accessible measures of methyl motion--the NMR-derived generalized order parameters--as a proxy from which to derive changes in protein conformational entropy.

  4. Design and Implementation of a 4K Cryocooler-Based Scanning Tunneling Microscope

    NASA Astrophysics Data System (ADS)

    Vishnubhotla, Ramya; Harrington, Neal; Dusch, Bill; Geng, Carrie; Bannerjee, Riju; Pabbi, Lavish; Hudson, Eric W.

    2013-03-01

    Low temperature, ultra-high vacuum scanning tunneling microscopes (STMs) have proved to be excellent tools for the study of electronic properties of complex materials. Unfortunately, with the continuing increase in liquid helium prices, already a dominant cost for operating these systems, their use is becoming exceedingly expensive. Here we describe the design and implementation of a STM cooled by a Cryomech PT407 Remote Motor Cryorefrigerator, allowing us to reach helium temperatures using a closed thermodynamic cycle with zero cryogen waste. Unfortunately, this refrigeration technique is not ultra-high vacuum (UHV) compatible and introduces vibrations. To tackle these problems, we separately house the cryocooler in a high-vacuum (HV) chamber. This provides both a UHV environment for the STM and mechanical isolation to minimize vibrations reaching the instrument. However, it makes for more challenging thermal connections. This last difficulty we solve by introducing a novel coaxial thermal feedthrough between the HV and UHV chambers. Supported by NSF DMR-0904400

  5. Identification of cancerous gastric cells based on common features extracted from hyperspectral microscopic images

    PubMed Central

    Zhu, Siqi; Su, Kang; Liu, Yumeng; Yin, Hao; Li, Zhen; Huang, Furong; Chen, Zhenqiang; Chen, Weidong; Zhang, Ge; Chen, Yihong

    2015-01-01

    We construct a microscopic hyperspectral imaging system to distinguish between normal and cancerous gastric cells. We study common transmission-spectra features that only emerge when the samples are dyed with hematoxylin and eosin (H&E) stain. Subsequently, we classify the obtained visible-range transmission spectra of the samples into three zones. Distinct features are observed in the spectral responses between the normal and cancerous cell nuclei in each zone, which depend on the pH level of the cell nucleus. Cancerous gastric cells are precisely identified according to these features. The average cancer-cell identification accuracy obtained with a backpropagation algorithm program trained with these features is 95%. PMID:25909000

  6. SPY: A new scission point model based on microscopic ingredients to predict fission fragments properties

    NASA Astrophysics Data System (ADS)

    Lemaître, J.-F.; Dubray, N.; Hilaire, S.; Panebianco, S.; Sida, J.-L.

    2013-12-01

    Our purpose is to determine fission fragments characteristics in a framework of a scission point model named SPY for Scission Point Yields. This approach can be considered as a theoretical laboratory to study fission mechanism since it gives access to the correlation between the fragments properties and their nuclear structure, such as shell correction, pairing, collective degrees of freedom, odd-even effects. Which ones are dominant in final state? What is the impact of compound nucleus structure? The SPY model consists in a statistical description of the fission process at the scission point where fragments are completely formed and well separated with fixed properties. The most important property of the model relies on the nuclear structure of the fragments which is derived from full quantum microscopic calculations. This approach allows computing the fission final state of extremely exotic nuclei which are inaccessible by most of the fission model available on the market.

  7. A direct micropipette-based calibration method for atomic force microscope cantilevers

    PubMed Central

    Liu, Baoyu; Yu, Yan; Yao, Da-Kang; Shao, Jin-Yu

    2009-01-01

    In this report, we describe a direct method for calibrating atomic force microscope (AFM) cantilevers with the micropipette aspiration technique (MAT). A closely fitting polystyrene bead inside a micropipette is driven by precisely controlled hydrostatic pressures to apply known loads on the sharp tip of AFM cantilevers, thus providing a calibration at the most functionally relevant position. The new method is capable of calibrating cantilevers with spring constants ranging from 0.01 to hundreds of newtons per meter. Under appropriate loading conditions, this new method yields measurement accuracy and precision both within 10%, with higher performance for softer cantilevers. Furthermore, this method may greatly enhance the accuracy and precision of calibration for colloidal probes. PMID:19566228

  8. Self-testable CMOS thermopile-based infrared imager

    NASA Astrophysics Data System (ADS)

    Charlot, Benoit; Parrain, F.; Mir, Salvador; Courtois, Bernard

    2001-04-01

    This paper describes a CMOS-compatible self-testable uncooled InfraRed (IR) imager that can be used in multiple applications such as overheating detection, night vision, and earth tracking for satellite positioning. The imager consists of an array of thermal pixels that sense an infrared radiation. Each pixel is implemented as a front-side bulk micromachined membrane suspended by four arms, each arm containing a thermopile made of Poly/Al thermocouples. The imager has a pixel self-test function that can be activated off-line in the field for validation and maintenance purposes, with an on-chip test signal generation that requires only slight modifications in the pixel design. The self-test of a pixel takes about 15 ms. The area overhead required by the test electronics does not imply any reduction of the pixel fill factor, since the electronics fits in the pixel silicon boundary. However, the additional self-test circuitry contributes to a small increase in the thermal conductance of a pixel due to the wiring of a heating resistor over the suspended arms. The self-test capability of the imager allows for a production test with a standard test equipment, without the need of special infrared sources and the associated optical equipment. A prototype with 8 X 8 pixels is currently in fabrication for validation of the self-test approach. In this prototype, each pixel occupies an area of 200 X 200 micrometer2, with a membrane size of 90 X 90 micrometer2 (fill factor of 0.2). Simulation results indicate a pixel thermal conductance of 22.6 (mu) W/K, giving a responsivity of 138 V/W, with a thermocouple Seebeck coefficient that has been measured at 248 (mu) V/K for the 0.6 micrometer CMOS technology used. The noise equivalent power (considering only Johnson noise in the thermopile) is calculated as 0.18 nW.H-1/2 with a detectivity of 5.03 X 107 cm.Hz1/2.W-1, in line with current state-of-the-art. Since the imager may need to measure irradiation intensities below 1(mu) W

  9. Demonstration of mid and long-wavelength infrared antimonide-based focal plane arrays

    NASA Astrophysics Data System (ADS)

    Hill, Cory J.; Soibel, Alexander; Keo, Sam A.; Mumolo, Jason M.; Ting, David Z.; Gunapala, Sarath D.; Rhiger, David R.; Kvaas, Robert E.; Harris, Sean F.

    2009-05-01

    We have demonstrated the use of bulk antimonide based materials and type-II antimonide based superlattices in the development of large area mid wavelength infrared (MWIR) focal plane arrays (FPAs) as well as smaller format long wavelength infrared (LWIR) arrays. Barrier infrared photodetectors (BIRDs) and superlattice-based infrared photodetectors are expected to outperform traditional III-V MWIR and LWIR imaging technologies and are expected to offer significant advantages over II-VI material based FPAs. We have used molecular beam epitaxy (MBE) technology to grow InAs/GaSb superlattice pin photodiode and bulk InAsSb structures on GaSb substrates. The coupled quantum well superlattice device offers additional control in wavelength tuning via quantum well sizes and ternary composition. Furthermore, we have fabricated mid-wavelength 1024x1024 pixels superlattice imaging FPAs, 640x512 MWIR arrays based on the BIRD concept, and 256x256 LWIR arrays based on pin superlattice structures. These initial FPA have produced excellent infrared imagery.

  10. Scale-space point spread function based framework to boost infrared target detection algorithms

    NASA Astrophysics Data System (ADS)

    Moradi, Saed; Moallem, Payman; Sabahi, Mohamad Farzan

    2016-07-01

    Small target detection is one of the major concern in the development of infrared surveillance systems. Detection algorithms based on Gaussian target modeling have attracted most attention from researchers in this field. However, the lack of accurate target modeling limits the performance of this type of infrared small target detection algorithms. In this paper, signal to clutter ratio (SCR) improvement mechanism based on the matched filter is described in detail and effect of Point Spread Function (PSF) on the intensity and spatial distribution of the target pixels is clarified comprehensively. In the following, a new parametric model for small infrared targets is developed based on the PSF of imaging system which can be considered as a matched filter. Based on this model, a new framework to boost model-based infrared target detection algorithms is presented. In order to show the performance of this new framework, the proposed model is adopted in Laplacian scale-space algorithms which is a well-known algorithm in the small infrared target detection field. Simulation results show that the proposed framework has better detection performance in comparison with the Gaussian one and improves the overall performance of IRST system. By analyzing the performance of the proposed algorithm based on this new framework in a quantitative manner, this new framework shows at least 20% improvement in the output SCR values in comparison with Laplacian of Gaussian (LoG) algorithm.

  11. InN Quantum Dot Based Infra-Red Photodetectors.

    PubMed

    Shetty, Arjun; Kumar, Mahesh; Roull, Basanta; Vinoy, K J; Krupanidhj, S B

    2016-01-01

    Self-assembled InN quantum dots (QDs) were grown on Si(111) substrate using plasma assisted molecular beam epitaxy (PA-MBE). Single-crystalline wurtzite structure of InN QDs was confirmed by X-ray diffraction. The dot densities were varied by varying the indium flux. Variation of dot density was confirmed by FESEM images. Interdigitated electrodes were fabricated using standard lithog- raphy steps to form metal-semiconductor-metal (MSM) photodetector devices. The devices show strong infrared response. It was found that the samples with higher density of InN QDs showed lower dark current and higher photo current. An explanation was provided for the observations and the experimental results were validated using Silvaco Atlas device simulator. PMID:27398511

  12. Antimony-based superlattices for high-performance infrared imagers

    NASA Astrophysics Data System (ADS)

    Walther, Martin; Rehm, Robert; Schmitz, Johannes; Rutz, Frank; Fleissner, Joachim; Ziegler, Johann

    2008-04-01

    InAs/GaSb short-period superlattices (SL) for the fabrication of mono- and bispectral thermal imaging systems in the mid-wavelength infrared region (MWIR) have been optimized in order to increase the spectral response of the imaging systems. The responsivity in monospectral InAs/GaSb short-period superlattices increases with the number of periods in the intrinsic region of the diode and does not show a diffusion limited behavior for detector structures with up to 1000 periods. This allows the fabrication of InAs/GaSb SL camera systems with high responsivity. Dual-color MWIR/MWIR InAs/GaSb SL camera systems with high quantum efficiency for missile approach warning systems with simultaneous and spatially coincident detection in both spectral channels have been realized.

  13. Fast approach to infrared image restoration based on shrinkage functions calibration

    NASA Astrophysics Data System (ADS)

    Zhang, Chengshuo; Shi, Zelin; Xu, Baoshu; Feng, Bin

    2016-05-01

    High-quality image restoration in real time is a challenge for infrared imaging systems. We present a fast approach to infrared image restoration based on shrinkage functions calibration. Rather than directly modeling the prior of sharp images to obtain the shrinkage functions, we calibrate them for restoration directly by using the acquirable sharp and blurred image pairs from the same infrared imaging system. The calibration method is employed to minimize the sum of squared errors between sharp images and restored images from the blurred images. Our restoration algorithm is noniterative and its shrinkage functions are stored in the look-up tables, so an architecture solution of pipeline structure can work in real time. We demonstrate the effectiveness of our approach by testing its quantitative performance from simulation experiments and its qualitative performance from a developed wavefront coding infrared imaging system.

  14. Infrared image non-rigid registration based on regional information entropy demons algorithm

    NASA Astrophysics Data System (ADS)

    Lu, Chaoliang; Ma, Lihua; Yu, Ming; Cui, Shumin; Wu, Qingrong

    2015-02-01

    Infrared imaging fault detection which is treated as an ideal, non-contact, non-destructive testing method is applied to the circuit board fault detection. Since Infrared images obtained by handheld infrared camera with wide-angle lens have both rigid and non-rigid deformations. To solve this problem, a new demons algorithm based on regional information entropy was proposed. The new method overcame the shortcomings of traditional demons algorithm that was sensitive to the intensity. First, the information entropy image was gotten by computing regional information entropy of the image. Then, the deformation between the two images was calculated that was the same as demons algorithm. Experimental results demonstrated that the proposed algorithm has better robustness in intensity inconsistent images registration compared with the traditional demons algorithm. Achieving accurate registration between intensity inconsistent infrared images provided strong support for the temperature contrast.

  15. The design of real time infrared image generation software based on Creator and Vega

    NASA Astrophysics Data System (ADS)

    Wang, Rui-feng; Wu, Wei-dong; Huo, Jun-xiu

    2013-09-01

    Considering the requirement of high reality and real-time quality dynamic infrared image of an infrared image simulation, a method to design real-time infrared image simulation application on the platform of VC++ is proposed. This is based on visual simulation software Creator and Vega. The functions of Creator are introduced simply, and the main features of Vega developing environment are analyzed. The methods of infrared modeling and background are offered, the designing flow chart of the developing process of IR image real-time generation software and the functions of TMM Tool and MAT Tool and sensor module are explained, at the same time, the real-time of software is designed.

  16. Locally adaptive regression filter-based infrared focal plane array non-uniformity correction

    NASA Astrophysics Data System (ADS)

    Li, Jia; Qin, Hanlin; Yan, Xiang; Huang, He; Zhao, Yingjuan; Zhou, Huixin

    2015-10-01

    Due to the limitations of the manufacturing technology, the response rates to the same infrared radiation intensity in each infrared detector unit are not identical. As a result, the non-uniformity of infrared focal plane array, also known as fixed pattern noise (FPN), is generated. To solve this problem, correcting the non-uniformity in infrared image is a promising approach, and many non-uniformity correction (NUC) methods have been proposed. However, they have some defects such as slow convergence, ghosting and scene degradation. To overcome these defects, a novel non-uniformity correction method based on locally adaptive regression filter is proposed. First, locally adaptive regression method is used to separate the infrared image into base layer containing main scene information and the detail layer containing detailed scene with FPN. Then, the detail layer sequence is filtered by non-linear temporal filter to obtain the non-uniformity. Finally, the high quality infrared image is obtained by subtracting non-uniformity component from original image. The experimental results show that the proposed method can significantly eliminate the ghosting and the scene degradation. The results of correction are superior to the THPF-NUC and NN-NUC in the aspects of subjective visual and objective evaluation index.

  17. Dual tunneling-unit scanning tunneling microscope for length measurement based on crystalline lattice

    SciTech Connect

    Zhang, H.; Higuchi, T.; Nishioki, N.

    1997-01-01

    A dual tunneling-unit scanning tunneling microscope (DTU STM) was developed for nm order length measurement with wide scan range. The crystalline lattice of highly oriented pyrolitic graphite (HOPG) was used as reference scale. A reference unit was set up on top of a test unit. The reference sample holder and the probe tip of test unit were attached to one single XY scanner on either surface, while the test sample holder was open. This enables simultaneous acquisition of wide images of HOPG and test sample. The length in test sample image was measured by counting the number of HOPG lattices. An inchworm actuator and an impact drive mechanism were introduced to roughly position probe tips. The XY scanner was designed to be elastic to eliminate image distortion. Some comparison experiments using two HOPG chips were carried out in air. The DTU STM is confirmed to be a stable and more powerful device for length measurement which has nanometer accuracy when covering a wide scan range up to several micrometers, and is capable of measuring comparatively large and heavy samples. {copyright} {ital 1997 American Vacuum Society.}

  18. High-speed atomic force microscope based on an astigmatic detection system

    SciTech Connect

    Liao, H.-S.; Chen, Y.-H.; Hwu, E.-T.; Chang, C.-S.; Hwang, I.-S.; Ding, R.-F.; Huang, H.-F.; Wang, W.-M.; Huang, K.-Y.

    2014-10-15

    High-speed atomic force microscopy (HS-AFM) enables visualizing dynamic behaviors of biological molecules under physiological conditions at a temporal resolution of 1s or shorter. A small cantilever with a high resonance frequency is crucial in increasing the scan speed. However, detecting mechanical resonances of small cantilevers is technically challenging. In this study, we constructed an atomic force microscope using a digital versatile disc (DVD) pickup head to detect cantilever deflections. In addition, a flexure-guided scanner and a sinusoidal scan method were implemented. In this work, we imaged a grating sample in air by using a regular cantilever and a small cantilever with a resonance frequency of 5.5 MHz. Poor tracking was seen at the scan rate of 50 line/s when a cantilever for regular AFM imaging was used. Using a small cantilever at the scan rate of 100 line/s revealed no significant degradation in the topographic images. The results indicate that a smaller cantilever can achieve a higher scan rate and superior force sensitivity. This work shows the potential for using a DVD pickup head in future HS-AFM technology.

  19. Computer-aided diagnosis of breast cancer based on fine needle biopsy microscopic images.

    PubMed

    Kowal, Marek; Filipczuk, Paweł; Obuchowicz, Andrzej; Korbicz, Józef; Monczak, Roman

    2013-10-01

    Prompt and widely available diagnostics of breast cancer is crucial for the prognosis of patients. One of the diagnostic methods is the analysis of cytological material from the breast. This examination requires extensive knowledge and experience of the cytologist. Computer-aided diagnosis can speed up the diagnostic process and allow for large-scale screening. One of the largest challenges in the automatic analysis of cytological images is the segmentation of nuclei. In this study, four different clustering algorithms are tested and compared in the task of fast nuclei segmentation. K-means, fuzzy C-means, competitive learning neural networks and Gaussian mixture models were incorporated for clustering in the color space along with adaptive thresholding in grayscale. These methods were applied in a medical decision support system for breast cancer diagnosis, where the cases were classified as either benign or malignant. In the segmented nuclei, 42 morphological, topological and texture features were extracted. Then, these features were used in a classification procedure with three different classifiers. The system was tested for classification accuracy by means of microscopic images of fine needle breast biopsies. In cooperation with the Regional Hospital in Zielona Góra, 500 real case medical images from 50 patients were collected. The acquired classification accuracy was approximately 96-100%, which is very promising and shows that the presented method ensures accurate and objective data acquisition that could be used to facilitate breast cancer diagnosis. PMID:24034748

  20. Automatic choroid cells segmentation and counting based on approximate convexity and concavity of chain code in fluorescence microscopic image

    NASA Astrophysics Data System (ADS)

    Lu, Weihua; Chen, Xinjian; Zhu, Weifang; Yang, Lei; Cao, Zhaoyuan; Chen, Haoyu

    2015-03-01

    In this paper, we proposed a method based on the Freeman chain code to segment and count rhesus choroid-retinal vascular endothelial cells (RF/6A) automatically for fluorescence microscopy images. The proposed method consists of four main steps. First, a threshold filter and morphological transform were applied to reduce the noise. Second, the boundary information was used to generate the Freeman chain codes. Third, the concave points were found based on the relationship between the difference of the chain code and the curvature. Finally, cells segmentation and counting were completed based on the characteristics of the number of the concave points, the area and shape of the cells. The proposed method was tested on 100 fluorescence microscopic cell images, and the average true positive rate (TPR) is 98.13% and the average false positive rate (FPR) is 4.47%, respectively. The preliminary results showed the feasibility and efficiency of the proposed method.

  1. Infrared thermography based studies on mobile phone induced heating

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Bagavathiappan, S.; Soumya, C.; Jayakumar, T.; Philip, John

    2015-07-01

    Here, we report the skin temperature rise due to the absorption of radio frequency (RF) energy from three handheld mobile phones using infrared thermography technique. Experiments are performed under two different conditions, viz. when the mobile phones are placed in soft touch with the skin surface and away from the skin surface. Additionally, the temperature rise of mobile phones during charging, operation and simultaneous charging and talking are monitored under different exposure conditions. It is observed that the temperature of the cheek and ear regions monotonically increased with time during the usage of mobile phones and the magnitude of the temperature rise is higher for the mobile phone with higher specific absorption rate. The increase in skin temperature is higher when the mobile phones are in contact with the skin surface due to the combined effect of absorption of RF electromagnetic power and conductive heat transfer. The increase in the skin temperature in non-contact mode is found to be within the safety limit of 1 °C. The measured temperature rise is in good agreement with theoretical predictions. The empirical equation obtained from the temperature rise on the cheek region of the subjects correlates well with the specific absorption rate of the mobile phones. Our study suggests that the use of mobile phones in non-contact mode can significantly lower the skin temperature rise during its use and hence, is safer compared to the contact mode.

  2. Software design of a digital holographic microscope based on MFC, multi-document and multi-thread

    NASA Astrophysics Data System (ADS)

    Zhang, Jialin; Zuo, Chao; Sun, Jiasong; Feng, Shijie; Zhang, Liguang; Fan, Yao; Hu, Yan; Kong, Fucheng; Chen, Qian; Zhang, Yuzheng; Chen, Dongdong; Tao, Tianyang; Lin, Fei; Yang, Yang; Tian, Chen

    2015-10-01

    Friendly interactive interface always significantly accelerate the progress of scientific research. However, most of the commercial softwares cannot meet the demand of a digital holographic microscope. Therefore, we designed a software in order to satisfy this requirement. We use Visual Studio 2010 to build this software, which is based on MFC multi-documents and multi-threads. The main process of designing this software is as follow: 1) Firstly, build the main frame of the software. It is easy to realize the basic interface of Windows style by programming with MFC. The most important thing in this module is adding algorithms and the functions of tool buttons to the program. 2) Secondly, implement functionality of each sub module. In this software, sub modules mainly mean sub windows. In order to have the unity of style, all sub windows use the similar toolbar. Specially, if one sub window have its own functionality, we will add button alone. 3) Thirdly, pass messages among modules. Passing messages among modules is significant in this software. The news in main program must be transmitted to the relevant sub window. The operation information in any sub windows must be transmitted to the main program, or transmitted to other sub windows. In order to make the program more efficient, we utilize multi-thread programming. With a digital holographic microscope, our software has many useful features, such as capturing the hologram of a sample (Holo View), displaying its Fourier spectrum (Fourier View), unwrapping phase map (Phase View), digital refocusing intensity information (Intensity View), drawing 2D line across the sample (2D View) and displaying three-dimensional images (Plot View). The experimental results demonstrate that a digital holographic microscope could be used much easier with the help of our software.

  3. Infrared image enhancement based on atmospheric scattering model and histogram equalization

    NASA Astrophysics Data System (ADS)

    Li, Yi; Zhang, Yunfeng; Geng, Aihui; Cao, Lihua; Chen, Juan

    2016-09-01

    Infrared images are fuzzy due to the special imaging technology of infrared sensor. In order to achieve contrast enhancement and gain clear edge details from a fuzzy infrared image, we propose an efficient enhancement method based on atmospheric scattering model and histogram equalization. The novel algorithm optimizes and improves the visual image haze remove method which combines the characteristics of the fuzzy infrared images. Firstly, an average filtering operation is presented to get the estimation of coarse transmission rate. Then we get the fuzzy free image through self-adaptive transmission rate calculated with the statistics information of original infrared image. Finally, to deal with low lighting problem of fuzzy free image, we propose a sectional plateau histogram equalization method which is capable of background suppression. Experimental results show that the performance and efficiency of the proposed algorithm are pleased, compared to four other algorithms in both subjective observation and objective quantitative evaluation. In addition, the proposed algorithm is competent to enhance infrared image for different applications under different circumstances.

  4. Infrared small target detection based on bilateral filtering algorithm with similarity judgments

    NASA Astrophysics Data System (ADS)

    Li, Yanbei; Li, Yan

    2014-11-01

    Infrared small target detection is part of the key technologies in infrared precision-guided, search and track system. Resulting from the relative distance of the infrared image system and the target is far, the target becomes small, faint and obscure. Furthermore, the interference of background clutter and system noise is intense. To solve the problem of infrared small target detection in a complex background, this paper proposes a bilateral filtering algorithm based on similarity judgments for infrared image background prediction. The algorithm introduces gradient factor and similarity judgment factor into traditional bilateral filtering. The two factors can enhance the accuracy of the algorithm for smooth region. At the same time, spatial proximity coefficients and gray similarity coefficient in the bilateral filtering are all expressed by the first two of McLaughlin expansion, which aiming at reducing the time overhead. Simulation results show that the proposed algorithm can effectively suppress complex background clutter in the infrared image and enhance target signal compared with the improved bilateral filtering algorithm, and it also can improve the signal to noise ratio (SNR) and contrast. Besides, this algorithm can reduce the computation time. In a word, this algorithm has a good background rejection performance.

  5. Infrared/laser multi-sensor fusion and tracking based on the multi-scale model

    NASA Astrophysics Data System (ADS)

    Wang, Bingjian; Hao, Jingya; Yi, Xiang; Wu, Feihong; Li, Min; Qin, Hanlin; Huang, Hanqiao

    2016-03-01

    The state estimation problem of targets detected by infrared/laser composite detection system with different sampling rates was studied in this paper. An effective state estimation algorithm based on data fusion is presented. Because sampling rate of infrared detection system is much higher than that of the laser detection system, the theory of multi-scale analysis is used to establish multi-scale model in this algorithm. At the fine scale, angle information provided by infrared detection system is used to estimate the target state through the unscented Kalman filter. It makes full use of the high frequency characteristic of infrared detection system to improve target state estimation accuracy. At the coarse scale, due to the sampling ratio of infrared and laser detection systems is an integer multiple, the angle information can be fused directly with the distance information of laser detection system to determine the target location. The fused information is served as observation, while the converted measurement Kalman filter (CMKF) is used to estimate the target state, which greatly reduces the complexity of filtering process and gets the optimal fusion estimation. The simulation results of tracking a target in 3-D space by infrared and laser detection systems demonstrate that the proposed algorithm in this paper is efficient and can obtain better performance than traditional algorithm.

  6. [Design and Preparation of Plant Bionic Materials Based on Optical and Infrared Features Simulation].

    PubMed

    Jiang, Xiao-jun; Lu, Xu-liang; Pan, Jia-liang; Zhang, Shuan-qin

    2015-07-01

    Due to the life characteristics such as physiological structure and transpiration, plants have unique optical and infrared features. In the optical band, because of the common effects of chlorophyll and water, plant leafs show spectral reflectance characteristics change in 550, 680, 1400 and 1900 nm significantly. In the infrared wave band, driven by transpiration, plants could regulate temperature on their own initiative, which make the infrared characteristics of plants different from artificial materials. So palnt bionic materials were proposed to simulate optical and infrared characteristics of plants. By analyzing formation mechanism of optical and infrared features about green plants, the component design and heat-transfer process of plants bionic materials were studied, above these the heat-transfer control formulation was established. Based on water adsorption/release compound, optical pigments and other man-made materials, plant bionic materials preparation methods were designed which could simulate the optical and infrared features of green plants. By chemical casting methods plant bionic material films were prepared, which use polyvinyl alcohol as film forming and water adsorption/release compound, and use optical pigments like chrome green and macromolecule yellow as colouring materials. The research conclusions achieved by testings figured out: water adsorption/release testing showed that the plant bionic materials with a certain thickness could absorb 1.3 kg water per square meter, which could satisfy the water usage of transpiration simulation one day; the optical and infrared simulated effect tests indicated that the plant bionic materials could preferably simulate the spectral reflective performance of green plants in optical wave band (380-2500 nm, expecially in 1400 and 1900 nm which were water absorption wave band of plants), and also it had similar daily infrared radiation variations with green plants, daily average radiation temperature

  7. [Design and Preparation of Plant Bionic Materials Based on Optical and Infrared Features Simulation].

    PubMed

    Jiang, Xiao-jun; Lu, Xu-liang; Pan, Jia-liang; Zhang, Shuan-qin

    2015-07-01

    Due to the life characteristics such as physiological structure and transpiration, plants have unique optical and infrared features. In the optical band, because of the common effects of chlorophyll and water, plant leafs show spectral reflectance characteristics change in 550, 680, 1400 and 1900 nm significantly. In the infrared wave band, driven by transpiration, plants could regulate temperature on their own initiative, which make the infrared characteristics of plants different from artificial materials. So palnt bionic materials were proposed to simulate optical and infrared characteristics of plants. By analyzing formation mechanism of optical and infrared features about green plants, the component design and heat-transfer process of plants bionic materials were studied, above these the heat-transfer control formulation was established. Based on water adsorption/release compound, optical pigments and other man-made materials, plant bionic materials preparation methods were designed which could simulate the optical and infrared features of green plants. By chemical casting methods plant bionic material films were prepared, which use polyvinyl alcohol as film forming and water adsorption/release compound, and use optical pigments like chrome green and macromolecule yellow as colouring materials. The research conclusions achieved by testings figured out: water adsorption/release testing showed that the plant bionic materials with a certain thickness could absorb 1.3 kg water per square meter, which could satisfy the water usage of transpiration simulation one day; the optical and infrared simulated effect tests indicated that the plant bionic materials could preferably simulate the spectral reflective performance of green plants in optical wave band (380-2500 nm, expecially in 1400 and 1900 nm which were water absorption wave band of plants), and also it had similar daily infrared radiation variations with green plants, daily average radiation temperature

  8. Atomic force microscope based near-field imaging for probing cell surface interactions

    NASA Astrophysics Data System (ADS)

    Amini, Sina

    Near-membrane and trans-membrane proteins and their interactions with the extracellular matrix (ECM) can yield valuable information about cell dynamics. However, advances in the field of nanoscale cellular processes have been hindered, in part, due to limits imposed by current technology. In this work, a novel evanescent field (EF) imaging technique is designed, modeled, created and tested for near-field imaging in the apical surface of cells. This technique and Forster resonance energy transfer (FRET) were used to investigate interactions between integrins on the cell surface and the ECM protein, fibronectin. The goal was to monitor changes in the integrin density at the cell surface as a function of clustering after binding to fibronectin on the microsphere surface. For the EF technique, quantum dot (QD)-embedded polystyrene microspheres were used to couple light into whispering gallery modes (WGMs) inside the microspheres; the resulting EF at the surface of the microsphere was used as a near-field excitation source with ~50 nm axial resolution for exciting fluorescently-labeled integrins. For FRET measurements (~10 nm axial resolution), QDs (donors) were coated on the surface of microspheres and energy transfer to red fluorescent protein (RFP)-integrin constructs (acceptors) studied. In both techniques, the QD-modified microspheres were mounted on atomic force microscope (AFM) cantilevers, functionalized with fibronectin, and brought into contact with fluorescently-labeled HeLa or vascular smooth muscle (VSM) cells. The results obtained from both methods show the clustering and activity of the integrins and are in good agreement with each other. Amsterdam discrete dipole approximation (ADDA) was used to study the effects of inhomogeneous surrounding refractive index on the quality factor and position of the WGMs due to the attachment of a microsphere to an AFM cantilever. WGMs of various QD-embedded microspheres mounted on AFM cantilevers were experimentally

  9. Air quality monitoring based on Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; Wang, Yan; Wang, Rui

    2006-09-01

    The use of optical techniques to identify and quantify atmospheric pollutants has been focused within the past two decades. Fourier Transform Infrared (FTIR) spectroscopy has proven to be a powerful tool for multi-component analysis of air quality monitoring. The technique has been used for gaseous samples by extractive sampling as well as in the open-path configuration. The present contribution has described the application of FTIR to analyze gaseous pollutants in ambient air in detail. The study for the detection limits of the interested gas, the design of the multipass White mirror system, and the experimental results are described. The White cell is employed to increase the absorbance relative to noise in the absorbance spectrum by increasing the path length without proportional loss of signal. A classical least squares (CLS) fit is used to match the scaled standards or previously measured absorption profiles to those of the observed spectrum in the specified spectral analysis regions for simultaneous quantification of the compounds of interest, plus several other ambient air constituents. The regions were chosen carefully to provide optimum detection of the compounds of interest with minimum interference by other compounds. Specially, spectrum subtraction and differential absorption concepts are introduced into FTIR data analysis. The optimal window for CO, S0 II, NO II, NO and CO II would be the region at 2250-2020 cm -1, 1230-1070 cm -1, 2940-2840 cm -1, 1965-1775 cm -1, and around 668.24 cm -1 respectively. Deviations from traditional measured results for all approaches are in 10%.

  10. Small infrared target detection by region-adaptive clutter rejection for sea-based infrared search and track.

    PubMed

    Kim, Sungho; Lee, Joohyoung

    2014-07-22

    This paper presents a region-adaptive clutter rejection method for small target detection in sea-based infrared search and track. In the real world, clutter normally generates many false detections that impede the deployment of such detection systems. Incoming targets (missiles, boats, etc.) can be located in the sky, horizon and sea regions, which have different types of clutters, such as clouds, a horizontal line and sea-glint. The characteristics of regional clutter were analyzed after the geometrical analysis-based region segmentation. The false detections caused by cloud clutter were removed by the spatial attribute-based classification. Those by the horizontal line were removed using the heterogeneous background removal filter. False alarms by sun-glint were rejected using the temporal consistency filter, which is the most difficult part. The experimental results of the various cluttered background sequences show that the proposed region adaptive clutter rejection method produces fewer false alarms than that of the mean subtraction filter (MSF) with an acceptable degradation detection rate.

  11. Small Infrared Target Detection by Region-Adaptive Clutter Rejection for Sea-Based Infrared Search and Track

    PubMed Central

    Kim, Sungho; Lee, Joohyoung

    2014-01-01

    This paper presents a region-adaptive clutter rejection method for small target detection in sea-based infrared search and track. In the real world, clutter normally generates many false detections that impede the deployment of such detection systems. Incoming targets (missiles, boats, etc.) can be located in the sky, horizon and sea regions, which have different types of clutters, such as clouds, a horizontal line and sea-glint. The characteristics of regional clutter were analyzed after the geometrical analysis-based region segmentation. The false detections caused by cloud clutter were removed by the spatial attribute-based classification. Those by the horizontal line were removed using the heterogeneous background removal filter. False alarms by sun-glint were rejected using the temporal consistency filter, which is the most difficult part. The experimental results of the various cluttered background sequences show that the proposed region adaptive clutter rejection method produces fewer false alarms than that of the mean subtraction filter (MSF) with an acceptable degradation detection rate. PMID:25054633

  12. Improvements to a Grating-Based Spectral Imaging Microscope and Its Application to Reflectance Analysis of Blue Pen Inks.

    PubMed

    McMillan, Leilani C; Miller, Kathleen P; Webb, Michael R

    2015-08-01

    A modified design of a chromatically resolved optical microscope (CROMoscope), a grating-based spectral imaging microscope, is described. By altering the geometry and adding a beam splitter, a twisting aberration that was present in the first version of the CROMoscope has been removed. Wavelength adjustment has been automated to decrease analysis time. Performance of the new design in transmission-absorption spectroscopy has been evaluated and found to be generally similar to the performance of the previous design. Spectral bandpass was found to be dependent on the sizes of apertures, and the smallest measured spectral bandpass was 1.8 nm with 1.0 mm diameter apertures. Wavelength was found to be very linear with the sine of the grating angle (R(2) = 0.9999995), and wavelength repeatability was found to be much better than the spectral bandpass. Reflectance spectral imaging with a CROMoscope is reported for the first time, and this reflectance spectral imaging was applied to blue ink samples on white paper. As a proof of concept, linear discriminant analysis was used to classify the inks by brand. In a leave-one-out cross-validation, 97.6% of samples were correctly classified. PMID:26162719

  13. Airborne measurements in the infrared using FTIR-based imaging hyperspectral sensors

    NASA Astrophysics Data System (ADS)

    Puckrin, E.; Turcotte, C. S.; Lahaie, P.; Dubé, D.; Farley, V.; Lagueux, P.; Marcotte, F.; Chamberland, M.

    2009-05-01

    Hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. Push-broom dispersive sensors have been typically used for airborne hyperspectral mapping. However, extending the spectral range towards the mid-wave and long-wave infrared brings performance limitations due to the self emission of the sensor itself. The Fourier-transform spectrometer technology has been extensively used in the infrared spectral range due to its high transmittance as well as throughput and multiplex advantages, thereby reducing the sensor self-emission problem. Telops has developed the Hyper-Cam, a rugged and compact infrared hyperspectral imager. The Hyper-Cam is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320x256 pixels at spectral resolutions of up to 0.25 cm-1. The Hyper-Cam has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. A special pointing module was designed to compensate for airplane attitude and forward motion. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. The first airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in

  14. Airborne measurements in the infrared using FTIR-based imaging hyperspectral sensors

    NASA Astrophysics Data System (ADS)

    Puckrin, E.; Turcotte, C. S.; Lahaie, P.; Dubé, D.; Lagueux, P.; Farley, V.; Marcotte, F.; Chamberland, M.

    2009-09-01

    Hyperspectral ground mapping is being used in an ever-increasing extent for numerous applications in the military, geology and environmental fields. The different regions of the electromagnetic spectrum help produce information of differing nature. The visible, near-infrared and short-wave infrared radiation (400 nm to 2.5 μm) has been mostly used to analyze reflected solar light, while the mid-wave (3 to 5 μm) and long-wave (8 to 12 μm or thermal) infrared senses the self-emission of molecules directly, enabling the acquisition of data during night time. Push-broom dispersive sensors have been typically used for airborne hyperspectral mapping. However, extending the spectral range towards the mid-wave and long-wave infrared brings performance limitations due to the self emission of the sensor itself. The Fourier-transform spectrometer technology has been extensively used in the infrared spectral range due to its high transmittance as well as throughput and multiplex advantages, thereby reducing the sensor self-emission problem. Telops has developed the Hyper-Cam, a rugged and compact infrared hyperspectral imager. The Hyper-Cam is based on the Fourier-transform technology yielding high spectral resolution and enabling high accuracy radiometric calibration. It provides passive signature measurement capability, with up to 320x256 pixels at spectral resolutions of up to 0.25 cm-1. The Hyper-Cam has been used on the ground in several field campaigns, including the demonstration of standoff chemical agent detection. More recently, the Hyper-Cam has been integrated into an airplane to provide airborne measurement capabilities. A special pointing module was designed to compensate for airplane attitude and forward motion. To our knowledge, the Hyper-Cam is the first commercial airborne hyperspectral imaging sensor based on Fourier-transform infrared technology. The first airborne measurements and some preliminary performance criteria for the Hyper-Cam are presented in

  15. Validation of a fiber-based confocal microscope for interventional image-guided procedures: correlation with multispectral optical imaging

    NASA Astrophysics Data System (ADS)

    Herzka, Daniel; Quijano, Jade; Xie, Jianwu; Krueger, Sascha; Weiss, Steffen; Abrat, Benjamin; Osdoit, Anne; Cavé, Charlotte; Burnett, Christopher; Danthi, S. Narasimhan; Li, King

    2006-03-01

    The concept of the biopsy is ubiquitous in current medical diagnosis of cancer and other diseases. The standard biopsy consists of removing a sample of tissue for evaluation and diagnosis, primarily to ascertain the presence of cancer cells by (histo)pathological analyses. However, the advent of new optical imaging modalities and targeted or "smart" agents, that have affinity for a select target, suggests the possibility of performing in vivo tissue characterization without the need for sample removal or the wait for histopathologic processing. Here we present work testing and validating a fiber-based confocal fluorescence microscopic imaging system intended for combination with a larger scale imaging modality (i.e. MRI or CT) to be used in image-guided in vivo tissue characterization. Fiber-based confocal fluorescence microscopic imaging experiments were performed (Cellvizio, Mauna Kea Technologies, Paris, France) in vivo in two mouse models including: 1) EGFP-expressing mouse melanoma model and 2) M21 mouse melanoma model. Both models are known to express integrin α νβ 3, a cell-surface receptor protein. We also performed an experiment in ex vivo chicken muscle tissue labelled with a fluorescein isothiocyanate-lectin targeted compound. In the mouse models, contrast agents that targeted the integrin were injected and the contrast agent localization in tumor was verified by a whole-body multispectral imager. The fiber-based tool was sensitive enough to detect and image the tissue of interest in all different experiments, and was found appropriate for use in interventional catheter-based procedures.

  16. Hybrid PSO-ASVR-based method for data fitting in the calibration of infrared radiometer.

    PubMed

    Yang, Sen; Li, Chengwei

    2016-06-01

    The present paper describes a hybrid particle swarm optimization-adaptive support vector regression (PSO-ASVR)-based method for data fitting in the calibration of infrared radiometer. The proposed hybrid PSO-ASVR-based method is based on PSO in combination with Adaptive Processing and Support Vector Regression (SVR). The optimization technique involves setting parameters in the ASVR fitting procedure, which significantly improves the fitting accuracy. However, its use in the calibration of infrared radiometer has not yet been widely explored. Bearing this in mind, the PSO-ASVR-based method, which is based on the statistical learning theory, is successfully used here to get the relationship between the radiation of a standard source and the response of an infrared radiometer. Main advantages of this method are the flexible adjustment mechanism in data processing and the optimization mechanism in a kernel parameter setting of SVR. Numerical examples and applications to the calibration of infrared radiometer are performed to verify the performance of PSO-ASVR-based method compared to conventional data fitting methods. PMID:27370427

  17. Image processing system design for microcantilever-based optical readout infrared arrays

    NASA Astrophysics Data System (ADS)

    Tong, Qiang; Dong, Liquan; Zhao, Yuejin; Gong, Cheng; Liu, Xiaohua; Yu, Xiaomei; Yang, Lei; Liu, Weiyu

    2012-12-01

    Compared with the traditional infrared imaging technology, the new type of optical-readout uncooled infrared imaging technology based on MEMS has many advantages, such as low cost, small size, producing simple. In addition, the theory proves that the technology's high thermal detection sensitivity. So it has a very broad application prospects in the field of high performance infrared detection. The paper mainly focuses on an image capturing and processing system in the new type of optical-readout uncooled infrared imaging technology based on MEMS. The image capturing and processing system consists of software and hardware. We build our image processing core hardware platform based on TI's high performance DSP chip which is the TMS320DM642, and then design our image capturing board based on the MT9P031. MT9P031 is Micron's company high frame rate, low power consumption CMOS chip. Last we use Intel's company network transceiver devices-LXT971A to design the network output board. The software system is built on the real-time operating system DSP/BIOS. We design our video capture driver program based on TI's class-mini driver and network output program based on the NDK kit for image capturing and processing and transmitting. The experiment shows that the system has the advantages of high capturing resolution and fast processing speed. The speed of the network transmission is up to 100Mbps.

  18. Hybrid PSO-ASVR-based method for data fitting in the calibration of infrared radiometer

    NASA Astrophysics Data System (ADS)

    Yang, Sen; Li, Chengwei

    2016-06-01

    The present paper describes a hybrid particle swarm optimization-adaptive support vector regression (PSO-ASVR)-based method for data fitting in the calibration of infrared radiometer. The proposed hybrid PSO-ASVR-based method is based on PSO in combination with Adaptive Processing and Support Vector Regression (SVR). The optimization technique involves setting parameters in the ASVR fitting procedure, which significantly improves the fitting accuracy. However, its use in the calibration of infrared radiometer has not yet been widely explored. Bearing this in mind, the PSO-ASVR-based method, which is based on the statistical learning theory, is successfully used here to get the relationship between the radiation of a standard source and the response of an infrared radiometer. Main advantages of this method are the flexible adjustment mechanism in data processing and the optimization mechanism in a kernel parameter setting of SVR. Numerical examples and applications to the calibration of infrared radiometer are performed to verify the performance of PSO-ASVR-based method compared to conventional data fitting methods.

  19. An infrared image super-resolution reconstruction method based on compressive sensing

    NASA Astrophysics Data System (ADS)

    Mao, Yuxing; Wang, Yan; Zhou, Jintao; Jia, Haiwei

    2016-05-01

    Limited by the properties of infrared detector and camera lens, infrared images are often detail missing and indistinct in vision. The spatial resolution needs to be improved to satisfy the requirements of practical application. Based on compressive sensing (CS) theory, this thesis presents a single image super-resolution reconstruction (SRR) method. With synthetically adopting image degradation model, difference operation-based sparse transformation method and orthogonal matching pursuit (OMP) algorithm, the image SRR problem is transformed into a sparse signal reconstruction issue in CS theory. In our work, the sparse transformation matrix is obtained through difference operation to image, and, the measurement matrix is achieved analytically from the imaging principle of infrared camera. Therefore, the time consumption can be decreased compared with the redundant dictionary obtained by sample training such as K-SVD. The experimental results show that our method can achieve favorable performance and good stability with low algorithm complexity.

  20. A graphene-based Fabry-Pérot spectrometer in mid-infrared region.

    PubMed

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-08-30

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region.

  1. A graphene-based Fabry-Pérot spectrometer in mid-infrared region

    NASA Astrophysics Data System (ADS)

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-08-01

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region.

  2. A graphene-based Fabry-Pérot spectrometer in mid-infrared region.

    PubMed

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-01-01

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region. PMID:27573080

  3. A graphene-based Fabry-Pérot spectrometer in mid-infrared region

    PubMed Central

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-01-01

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region. PMID:27573080

  4. Infrared thermography based magnetic hyperthermia study in Fe3O4 based magnetic fluids

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Ranoo, Surojit; Philip, John

    2016-09-01

    Owing to the immense clinical benefits, magnetic hyperthermia is likely to emerge as an alternate cancer therapeutic procedure in the near future. Presently, radio frequency immune fiber optic based sensors are being used to monitor temperature changes during magnetic hyperthermia measurements, which have inherent limitations due to the requirement of physical contact of the sensor with the sample, contamination and temperature monitoring at a single point. Here, we investigate the field induced heating of oil based oleic acid coated Fe3O4 nanofluid, synthesized using co-precipitation method, using infrared thermal imaging (IRT) camera and compare the results with those of fiber optic temperature sensor. Experiments were performed on nanofluid samples of four different concentrations and under five different external field amplitudes. The specific absorption rate (SAR) of the samples were determined from the initial rate of temperature rise measured using both the techniques. The SAR values determined from both the techniques were in very good agreement with each other, with in an accuracy of 5%, after incorporating convection loss correction on the infrared thermal imaging data. The consecutive thermal cycling on the samples showed good thermal stability and thermal recovery. The maximum SAR obtained was 95.9 W/gFe for a sample concentration and field amplitude of 23 wt.% and 57.3 kA m-1, respectively. This study showed the efficacy and accuracy of temperature measurement using IRT during field induced heating of magnetic nanofluid and its advantages over conventional point measurements techniques for real-time, non-contact and wide area temperature mapping without sample contamination.

  5. Infrared and multi-type images fusion algorithm based on contrast pyramid transform

    NASA Astrophysics Data System (ADS)

    Xu, Hua; Wang, Yan; Wu, Yujing; Qian, Yunsheng

    2016-09-01

    A fusion algorithm for infrared and multi-type images based on contrast pyramid transform (CPT) combined with Otsu method and morphology is proposed in this paper. Firstly, two sharpened images are combined to the first fused image based on information entropy weighted scheme. Afterwards, two enhanced images and the first fused one are decomposed into a series of images with different dimensions and spatial frequencies. To the low-frequency layer, the Otsu method is applied to calculate the optimal segmentation threshold of the first fused image, which is subsequently used to determine the pixel values in top layer fused image. With respect to the high-frequency layers, the top-bottom hats morphological transform is employed to each layer before maximum selection criterion. Finally, the series of decomposed images are reconstructed and then superposed with the enhanced image processed by morphological gradient operation as a second fusion to get the final fusion image. Infrared and visible images fusion, infrared and low-light-level (LLL) images fusion, infrared intensity and infrared polarization images fusion, and multi-focus images fusion are discussed in this paper. Both experimental results and objective metrics demonstrate the effectiveness and superiority of the proposed algorithm over the conventional ones used to compare.

  6. Analysis of biofluids in aqueous environment based on mid-infrared spectroscopy.

    PubMed

    Fabian, Heinz; Lasch, Peter; Naumann, Dieter

    2005-01-01

    In this study we describe a semiautomatic Fourier transform infrared spectroscopic methodology for the analysis of liquid serum samples, which combines simple sample introduction with high sample throughput. The applicability of this new infrared technology to the analysis of liquid serum samples from a cohort of cattle naturally infected with bovine spongiform encephalopathy and from controls was explored in comparison to the conventional approach based on transmission infrared spectroscopy of dried serum films. Artifical neural network analysis of the infrared data was performed to differentiate between bovine spongiform encephalopathy-negative controls and animals in the late stage of the disease. After training of artifical neural network classifiers, infrared spectra of sera from an independent external validation data set were analyzed. In this way, sensitivities between 90 and 96% and specificities between 84 and 92% were achieved, respectively, depending upon the strategy of data collection and data analysis. Based on these results, the advantages and limitations of the liquid sample technique and the dried film approach for routine analysis of biofluids are discussed.

  7. Monitoring TriAcylGlycerols Accumulation by Atomic Force Microscopy Based Infrared Spectroscopy in Streptomyces Species for Biodiesel Applications.

    PubMed

    Deniset-Besseau, Ariane; Prater, Craig B; Virolle, Marie-Joëlle; Dazzi, Alexandre

    2014-02-20

    An atomic force microscope coupled with a tunable infrared laser source (AFM-IR) was used to measure the size and map the distribution of oil inclusions inside of microorganism without staining or other special sample preparation. The microorganism under study is Streptomyces, a soil bacterium that possesses the capability, under some specific nutritional conditions, to store its carbon source into TriAcylGlycerols, a potential direct source of biodiesel. PMID:26270832

  8. In situ microparticle analysis of marine phytoplankton cells with infrared laser-based optical tweezers

    NASA Astrophysics Data System (ADS)

    Sonek, G. J.; Liu, Y.; Iturriaga, R. H.

    1995-11-01

    We describe the application of infrared optical tweezers to the in situ microparticle analysis of marine phytoplankton cells. A Nd:YAG laser (lambda=3D 1064 nm) trap is used to confine and manipulate single Nannochloris and Synechococcus cells in an enriched seawater medium while spectral fluorescence and Lorenz-Mie backscatter signals are simultaneously acquired under a variety of excitation and trapping conditions. Variations in the measured fluorescence intensities of chlorophyll a (Chl a) and phycoerythrin pigments in phytoplankton cells are observed. These variations are related, in part, to basic intrasample variability, but they also indicate that increasing ultraviolet-exposure time and infrared trapping power may have short-term effects on cellular physiology that are related to Chl a photobleaching and laser-induced heating, respectively. The use of optical tweezers to study the factors that affect marine cell physiology and the processes of absorption, scattering, and attenuation by individual cells, organisms, and particulate matter that contribute to optical closure on a microscopic scale are also described. (c)1995 Optical Society of America

  9. Binary mixtures of rod-like colloids under shear: microscopically-based equilibrium theory and order-parameter dynamics.

    PubMed

    Lugo-Frías, Rodrigo; Klapp, Sabine H L

    2016-06-22

    This paper is concerned with the dynamics of a binary mixture of rod-like, repulsive colloidal particles driven out of equilibrium by means of a steady shear flow (Couette geometry). To this end we first derive, starting from a microscopic density functional in Parsons-Lee approximation, a mesoscopic free energy functional whose main variables are the orientational order parameter tensors. Based on this mesoscopic functional we then explore the stability of isotropic and nematic equilibrium phases in terms of composition and rod lengths. Second, by combining the equilibrium theory with the Doi-Hess approach for the order parameter dynamics under shear, we investigate the orientational dynamics of binary mixtures for a range of shear rates and coupling parameters. We find a variety of dynamical states, including synchronized oscillatory states of the two components, but also symmetry breaking behavior where the components display different in-plane oscillatory states.

  10. Binary mixtures of rod-like colloids under shear: microscopically-based equilibrium theory and order-parameter dynamics.

    PubMed

    Lugo-Frías, Rodrigo; Klapp, Sabine H L

    2016-06-22

    This paper is concerned with the dynamics of a binary mixture of rod-like, repulsive colloidal particles driven out of equilibrium by means of a steady shear flow (Couette geometry). To this end we first derive, starting from a microscopic density functional in Parsons-Lee approximation, a mesoscopic free energy functional whose main variables are the orientational order parameter tensors. Based on this mesoscopic functional we then explore the stability of isotropic and nematic equilibrium phases in terms of composition and rod lengths. Second, by combining the equilibrium theory with the Doi-Hess approach for the order parameter dynamics under shear, we investigate the orientational dynamics of binary mixtures for a range of shear rates and coupling parameters. We find a variety of dynamical states, including synchronized oscillatory states of the two components, but also symmetry breaking behavior where the components display different in-plane oscillatory states. PMID:27115342

  11. Sensitivity analysis of rectangular atomic force microscope cantilevers immersed in liquids based on the modified couple stress theory.

    PubMed

    Lee, Haw-Long; Chang, Win-Jin

    2016-01-01

    The modified couple stress theory is adopted to study the sensitivity of a rectangular atomic force microscope (AFM) cantilever immersed in acetone, water, carbon tetrachloride (CCl4), and 1-butanol. The theory contains a material length scale parameter and considers the size effect in the analysis. However, this parameter is difficult to obtain via experimental measurements. In this study, a conjugate gradient method for the parameter estimation of the frequency equation is presented. The optimal method provides a quantitative approach for estimating the material length scale parameter based on the modified couple stress theory. The results show that the material length scale parameter of the AFM cantilever immersed in acetone, CCl4, water, and 1-butanol is 0, 25, 116.3, and 471 nm, respectively. In addition, the vibration sensitivities of the AFM cantilever immersed in these liquids are investigated. The results are useful for the design of AFM cantilevers immersed in liquids.

  12. Binary mixtures of rod-like colloids under shear: microscopically-based equilibrium theory and order-parameter dynamics

    NASA Astrophysics Data System (ADS)

    Lugo-Frías, Rodrigo; Klapp, Sabine H. L.

    2016-06-01

    This paper is concerned with the dynamics of a binary mixture of rod-like, repulsive colloidal particles driven out of equilibrium by means of a steady shear flow (Couette geometry). To this end we first derive, starting from a microscopic density functional in Parsons-Lee approximation, a mesoscopic free energy functional whose main variables are the orientational order parameter tensors. Based on this mesoscopic functional we then explore the stability of isotropic and nematic equilibrium phases in terms of composition and rod lengths. Second, by combining the equilibrium theory with the Doi-Hess approach for the order parameter dynamics under shear, we investigate the orientational dynamics of binary mixtures for a range of shear rates and coupling parameters. We find a variety of dynamical states, including synchronized oscillatory states of the two components, but also symmetry breaking behavior where the components display different in-plane oscillatory states.

  13. Scanning photon microscope based on ac surface photovoltage: applications to nondestructive evaluation of metallic contaminants in silicon wafers

    NASA Astrophysics Data System (ADS)

    Shimizu, Hirofumi; Munakata, Chusuke

    1995-09-01

    A scanning photon microscope based on ac surface photovoltage (SPV), which can be used to characterize electronic charges in silicon (Si) wafers, is successfully applied for nondestructive detection of metallic contaminants. If Al3+ and Fe3+ replace Si4+ in a native oxide, (AlOSi)- and (FeOSi)- networks form and a negative charge appears. However, P$5+) acts as a positive charge, possibly in the form of (POSi)+. Thermal oxidation causes Al and Fe to segregate at the very top of the thermal oxide and a negative charge survives. Dipping in an aqueous hydrofluoric acid (HF) solution causes a positive charge at wafer surfaces. When n-type Si wafers treated with HF solution are dipped in aqueous solutions containing Fe or Cu ions, the net negative charge is proportionally enhanced as the Fe or Cu concentration increases, resulting in the appearance of an ac SPV.

  14. Photon path distribution and optical responses of turbid media: theoretical analysis based on the microscopic Beer-Lambert law.

    PubMed

    Tsuchiya, Y

    2001-08-01

    A concise theoretical treatment has been developed to describe the optical responses of a highly scattering inhomogeneous medium using functions of the photon path distribution (PPD). The treatment is based on the microscopic Beer-Lambert law and has been found to yield a complete set of optical responses by time- and frequency-domain measurements. The PPD is defined for possible photons having a total zigzag pathlength of l between the points of light input and detection. Such a distribution is independent of the absorption properties of the medium and can be uniquely determined for the medium under quantification. Therefore, the PPD can be calculated with an imaginary reference medium having the same optical properties as the medium under quantification except for the absence of absorption. One of the advantages of this method is that the optical responses, the total attenuation, the mean pathlength, etc are expressed by functions of the PPD and the absorption distribution.

  15. Flexible infrared detectors based on p-n junctions of multi-walled carbon nanotubes.

    PubMed

    Huang, Zhenlong; Gao, Min; Yan, Zhuocheng; Pan, Taisong; Liao, Feiyi; Lin, Yuan

    2016-05-14

    Different types of multi-walled carbon nanotubes (CNTs), synthesized by chemical vapor deposition, are used to fabricate infrared (IR) detectors on flexible substrates based on CNT p-n junctions. It is found that this kind of detector is sensitive to infrared signals with a power density as low as 90 μW mm(-2) even at room temperature. Besides, unlike other devices, the detector with this unique structure can be bent for 100 cycles without any damage and its functionality does not degenerate once it recovers to the initial state. The results give a good reference for developing efficient, low-cost, and flexible IR detectors. PMID:27101973

  16. An infrared thermal image processing framework based on superpixel algorithm to detect cracks on metal surface

    NASA Astrophysics Data System (ADS)

    Xu, Changhang; Xie, Jing; Chen, Guoming; Huang, Weiping

    2014-11-01

    Infrared thermography has been used increasingly as an effective non-destructive technique to detect cracks on metal surface. Due to many factors, infrared thermal image has low definition compared to visible image. The contrasts between cracks and sound areas in different thermal image frames of a specimen vary greatly with the recorded time. An accurate detection can only be obtained by glancing over the whole thermal video, which is a laborious work. Moreover, experience of the operator has a great important influence on the accuracy of detection result. In this paper, an infrared thermal image processing framework based on superpixel algorithm is proposed to accomplish crack detection automatically. Two popular superpixel algorithms are compared and one of them is selected to generate superpixels in this application. Combined features of superpixels were selected from both the raw gray level image and the high-pass filtered image. Fuzzy c-means clustering is used to cluster superpixels in order to segment infrared thermal image. Experimental results show that the proposed framework can recognize cracks on metal surface through infrared thermal image automatically.

  17. Advancements in quantum cascade laser-based infrared microscopy of aqueous media.

    PubMed

    Haase, K; Kröger-Lui, N; Pucci, A; Schönhals, A; Petrich, W

    2016-06-23

    The large mid-infrared absorption coefficient of water frequently hampers the rapid, label-free infrared microscopy of biological objects in their natural aqueous environment. However, the high spectral power density of quantum cascade lasers is shifting this limitation such that mid-infrared absorbance images can be acquired in situ within signal-to-noise ratios of up to 100. Even at sample thicknesses well above 50 μm, signal-to-noise ratios above 10 are readily achieved. The quantum cascade laser-based microspectroscopy of aqueous media is exemplified by imaging an aqueous yeast solution and quantifying glucose consumption, ethanol generation as well as the production of carbon dioxide gas during fermentation. PMID:27032367

  18. Advancements in quantum cascade laser-based infrared microscopy of aqueous media.

    PubMed

    Haase, K; Kröger-Lui, N; Pucci, A; Schönhals, A; Petrich, W

    2016-06-23

    The large mid-infrared absorption coefficient of water frequently hampers the rapid, label-free infrared microscopy of biological objects in their natural aqueous environment. However, the high spectral power density of quantum cascade lasers is shifting this limitation such that mid-infrared absorbance images can be acquired in situ within signal-to-noise ratios of up to 100. Even at sample thicknesses well above 50 μm, signal-to-noise ratios above 10 are readily achieved. The quantum cascade laser-based microspectroscopy of aqueous media is exemplified by imaging an aqueous yeast solution and quantifying glucose consumption, ethanol generation as well as the production of carbon dioxide gas during fermentation.

  19. Infrared moving point target detection based on spatial-temporal local contrast filter

    NASA Astrophysics Data System (ADS)

    Deng, Lizhen; Zhu, Hu; Tao, Chao; Wei, Yantao

    2016-05-01

    Infrared moving point target detection is a challenging task. In this paper, we define a novel spatial local contrast (SLC) and a novel temporal local contrast (TLC) to enhance the target's contrast. Based on the defined spatial local contrast and temporal local contrast, we propose a simple but powerful spatial-temporal local contrast filter (STLCF) to detect moving point target from infrared image sequences. In order to verify the performance of spatial-temporal local contrast filter on detecting moving point target, different detection methods are used to detect the target from several infrared image sequences for comparison. The experimental results show that the proposed spatial-temporal local contrast filter has great superiority in moving point target detection.

  20. Architecture and performance of the space-based Far-Infrared Interferometer Instrument Simulator

    NASA Astrophysics Data System (ADS)

    Juanola-Parramon, R.; Fenech, D. M.; Savini, G.

    2016-04-01

    FIRI (Far Infra-Red Interferometer) is a spatial and spectral space interferometer with an operating wavelength range of 25-400 μm and sub-arcsecond angular resolution. It is based on the combination of stellar interferometry and Fourier transform spectroscopy to perform spectroscopy at high angular resolution in the far-infrared. The resulting technique is referred to as double Fourier spatio-spectral interferometry. With increased spatial and spectral resolution come a number of interesting science cases such as the formation and evolution of AGN and the characterization of gas, ice and dust in discs undergoing planetary formation, among others. To study the feasibility of a FIRI system, the Far-Infrared Interferometer Instrument Simulator (FIInS) has been developed. With FIInS, once a set of modelled scientific data is available, one can compare an input sky map with the synthesized one after data reduction algorithms have been applied.

  1. Evaluation of paint coating thickness variations based on pulsed Infrared thermography laser technique

    NASA Astrophysics Data System (ADS)

    Mezghani, S.; Perrin, E.; Vrabie, V.; Bodnar, J. L.; Marthe, J.; Cauwe, B.

    2016-05-01

    In this paper, a pulsed Infrared thermography technique using a homogeneous heat provided by a laser source is used for the non-destructive evaluation of paint coating thickness variations. Firstly, numerical simulations of the thermal response of a paint coated sample are performed. By analyzing the thermal responses as a function of thermal properties and thickness of both coating and substrate layers, optimal excitation parameters of the heating source are determined. Two characteristic parameters were studied with respect to the paint coating layer thickness variations. Results obtained using an experimental test bench based on the pulsed Infrared thermography laser technique are compared with those given by a classical Eddy current technique for paint coating variations from 5 to 130 μm. These results demonstrate the efficiency of this approach and suggest that the pulsed Infrared thermography technique presents good perspectives to characterize the heterogeneity of paint coating on large scale samples with other heating sources.

  2. "Key to Freshwater Algae": A Web-Based Tool to Enhance Understanding of Microscopic Biodiversity

    ERIC Educational Resources Information Center

    Shayler, Hannah A.; Siver, Peter A.

    2006-01-01

    The Freshwater Ecology Laboratory at Connecticut College has developed an interactive, Web-based identification key to freshwater algal genera using the Lucid Professional and Lucid 3 software developed by the Centre for Biological Information Technology at the University of Queensland, Brisbane, Australia. The "Key to Freshwater Algae" was funded…

  3. A model for μ-biomimetic thermal infrared sensors based on the infrared receptors of Melanophila acuminata.

    PubMed

    Siebke, Georg; Holik, Peter; Schmitz, Sam; Schmitz, Helmut; Lacher, Manfred; Steltenkamp, Siegfried

    2014-09-01

    Beetles of the genus Melanophila acuminata detect forest fires from distances as far as 130 km with infrared-sensing organs. Inspired by this extremely sensitive biological device, we are developing an IR sensor that operates at ambient temperature using MEMS technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of these chambers leads to heating and expansion of a liquid. The increasing pressure deflects a membrane covered by one electrode of a plate capacitor. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. However, the strong frequency dependence of the filter demands a precise characterization of its properties. Here, we present a theoretical model that describes the frequency-dependent response of the sensor based on material properties and geometrical dimensions. Our model is divided into four distinct parts that address different aspects of the sensor. The model describes the frequency-dependent behaviour of the fluidic filter and a thermal low-pass filter as well as saturation effects at low frequencies. This model allows the calculation of optimal design parameters, and thereby provides the foundation for the development of such a sensor.

  4. Soft nanomaterial-based targeting polymersomes for near-infrared fluorescence multispectral in vivo imaging.

    PubMed

    Li, Zuhong; Wu, Liyuan; Hu, Peiran; Han, Sihai; Zhang, Tao; Fan, Hongliang; Jin, Wei; Jin, Qinhan; Mu, Ying

    2012-11-21

    We report here the soft nanomaterial-based targeting polymersomes for near-infrared (NIR) fluorescence imaging to carry out in vivo tumor detection. Two polymersome-based NIR fluorescent probes were prepared through the self-assembly of amphiphilic block copolymers, poly(butadiene-b-ethylene oxide) (PEO-b-PBD). Each of them was encapsulated with distinct hydrophobic near-infrared dyes (DiD and DiR) and modified with different targeting ligands (anti-CEA antibody and anti-EGFR antibody), respectively. After simultaneous injection of these two probes into the tumor-bearing mice via tail vein, multispectral near-infrared fluorescence images were obtained. The results indicate that both probes are successfully directed to the tumor foci, where two distinguishable fluorescent signals were detected through the unmixed fluorescence images. By taking advantage of two targeting polymersome-based probes with distinct fluorescent features, the proposed multispectral near-infrared fluorescence imaging method can greatly improve the specificity and accuracy for in vivo tumor detection.

  5. Infrared image guidance for ground vehicle based on fast wavelet image focusing and tracking

    NASA Astrophysics Data System (ADS)

    Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

    2009-08-01

    We studied the infrared image guidance for ground vehicle based on the fast wavelet image focusing and tracking. Here we uses the image of the uncooled infrared imager mounted on the two axis gimbal system and the developed new auto focusing algorithm on the Daubechies wavelet transform. The developed new focusing algorithm on the Daubechies wavelet transform processes the result of the high pass filter effect to meet the direct detection of the objects. This new focusing gives us the distance information of the outside world smoothly, and the information of the gimbal system gives us the direction of objects in the outside world to match the sense of the spherical coordinate system. We installed this system on the hand made electric ground vehicle platform powered by 24VDC battery. The electric vehicle equips the rotary encoder units and the inertia rate sensor units to make the correct navigation process. The image tracking also uses the developed newt wavelet focusing within several image processing. The size of the hand made electric ground vehicle platform is about 1m long, 0.75m wide, 1m high, and 50kg weight. We tested the infrared image guidance for ground vehicle based on the new wavelet image focusing and tracking using the electric vehicle indoor and outdoor. The test shows the good results by the developed infrared image guidance for ground vehicle based on the new wavelet image focusing and tracking.

  6. Soft nanomaterial-based targeting polymersomes for near-infrared fluorescence multispectral in vivo imaging

    NASA Astrophysics Data System (ADS)

    Li, Zuhong; Wu, Liyuan; Hu, Peiran; Han, Sihai; Zhang, Tao; Fan, Hongliang; Jin, Wei; Jin, Qinhan; Mu, Ying

    2012-10-01

    We report here the soft nanomaterial-based targeting polymersomes for near-infrared (NIR) fluorescence imaging to carry out in vivo tumor detection. Two polymersome-based NIR fluorescent probes were prepared through the self-assembly of amphiphilic block copolymers, poly(butadiene-b-ethylene oxide) (PEO-b-PBD). Each of them was encapsulated with distinct hydrophobic near-infrared dyes (DiD and DiR) and modified with different targeting ligands (anti-CEA antibody and anti-EGFR antibody), respectively. After simultaneous injection of these two probes into the tumor-bearing mice via tail vein, multispectral near-infrared fluorescence images were obtained. The results indicate that both probes are successfully directed to the tumor foci, where two distinguishable fluorescent signals were detected through the unmixed fluorescence images. By taking advantage of two targeting polymersome-based probes with distinct fluorescent features, the proposed multispectral near-infrared fluorescence imaging method can greatly improve the specificity and accuracy for in vivo tumor detection.

  7. 1Click1View: Interactive Visualization Methodology for RNAi Cell-Based Microscopic Screening

    PubMed Central

    Zwolinski, Lukasz; Kozak, Marta; Kozak, Karol

    2013-01-01

    Technological advancements are constantly increasing the size and complexity of data resulting from large-scale RNA interference screens. This fact has led biologists to ask complex questions, which the existing, fully automated analyses are often not adequate to answer. We present a concept of 1Click1View (1C1V) as a methodology for interactive analytic software tools. 1C1V can be applied for two-dimensional visualization of image-based screening data sets from High Content Screening (HCS). Through an easy-to-use interface, one-click, one-view concept, and workflow based architecture, visualization method facilitates the linking of image data with numeric data. Such method utilizes state-of-the-art interactive visualization tools optimized for fast visualization of large scale image data sets. We demonstrate our method on an HCS dataset consisting of multiple cell features from two screening assays. PMID:23484084

  8. Microscopic understanding of heavy-tailed return distributions in an agent-based model

    NASA Astrophysics Data System (ADS)

    Schmitt, Thilo A.; Schäfer, Rudi; Münnix, Michael C.; Guhr, Thomas

    2012-11-01

    The distribution of returns in financial time series exhibits heavy tails. It has been found that gaps between the orders in the order book lead to large price shifts and thereby to these heavy tails. We set up an agent-based model to study this issue and, in particular, how the gaps in the order book emerge. The trading mechanism in our model is based on a double-auction order book. In situations where the order book is densely occupied with limit orders we do not observe fat-tailed distributions. As soon as less liquidity is available, a gap structure forms which leads to return distributions with heavy tails. We show that return distributions with heavy tails are an order-book effect if the available liquidity is constrained. This is largely independent of specific trading strategies.

  9. 1Click1View: interactive visualization methodology for RNAi cell-based microscopic screening.

    PubMed

    Zwolinski, Lukasz; Kozak, Marta; Kozak, Karol

    2013-01-01

    Technological advancements are constantly increasing the size and complexity of data resulting from large-scale RNA interference screens. This fact has led biologists to ask complex questions, which the existing, fully automated analyses are often not adequate to answer. We present a concept of 1Click1View (1C1V) as a methodology for interactive analytic software tools. 1C1V can be applied for two-dimensional visualization of image-based screening data sets from High Content Screening (HCS). Through an easy-to-use interface, one-click, one-view concept, and workflow based architecture, visualization method facilitates the linking of image data with numeric data. Such method utilizes state-of-the-art interactive visualization tools optimized for fast visualization of large scale image data sets. We demonstrate our method on an HCS dataset consisting of multiple cell features from two screening assays.

  10. Determination of microscopic acid-base parameters from NMR-pH titrations.

    PubMed

    Szakács, Zoltán; Kraszni, Márta; Noszál, Béla

    2004-03-01

    The theory and practice of proton microspeciation based on NMR-pH titrations are surveyed. Principles of bi-, tri-, tetra-, and n-protic microequilibrium systems are discussed. Evaluation methods are exemplified by case studies on bi- and tetraprotic biomolecules. Selection criteria and properties of 'reporter' NMR nuclei are described. Literature data on complete microspeciations of small ligands and site-specific basicity characterizations of peptides and proteins are critically reviewed.

  11. NEAR-INFRARED THERMAL EMISSION DETECTIONS OF A NUMBER OF HOT JUPITERS AND THE SYSTEMATICS OF GROUND-BASED NEAR-INFRARED PHOTOMETRY

    SciTech Connect

    Croll, Bryce; Albert, Loic; Lafreniere, David; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

    2015-03-20

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K {sub CONT}-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations.

  12. A custom-built two-photon microscope based on a mode-locked Yb3+ doped fiber laser

    NASA Astrophysics Data System (ADS)

    Kim, Dong Uk; Song, Hoseong; Song, Woosub, III; Kwon, Hyuk-Sang; Kim, Dug Yong

    2012-03-01

    Two-photon microscopy is a very attractive tool for the study of the three-dimensional (3D) and dynamic processes in cells and tissues. One of the feasible constructions of two-photon microscopy is the combination a confocal laser scanning microscope and a mode-locked Ti:sapphire laser. Even though this approach is the simplest and fastest implementation, this system is highly cost-intensive and considerably difficult in modification. Many researcher therefore decide to build a more cost-effective and flexible system with a self-developed software for operation and data acquisition. We present a custom-built two-photon microscope based on a mode-locked Yb3+ doped fiber laser and demonstrate two-photon fluorescence imaging of biological specimens. The mode-locked fiber laser at 1060 nm delivers 320 fs laser pulses at a frequency of 36 MHz up to average power of 80 mW. The excitation at 1060 nm can be more suitable in thick, turbid samples for 3D image construction as well as cell viability. The system can simply accomplish confocal and two-photon mode by an additional optical coupler that allows conventional laser source to transfer to the scanning head. The normal frame rate is 1 frames/s for 400 x 400 pixel images. The measured full width at half maximum resolutions were about 0.44 μm laterally and 1.34 μm axially. A multi-color stained convallaria, rat basophilic leukemia cells and a rat brain tissue were observed by two-photon fluorescence imaging in our system.

  13. Dynamic infrared scene projectors based upon the DMD

    NASA Astrophysics Data System (ADS)

    Beasley, D. Brett; Bender, Matt; Crosby, Jay; Messer, Tim

    2009-02-01

    The Micromirror Array Projector System (MAPS) is an advanced dynamic scene projector system developed by Optical Sciences Corporation (OSC) for Hardware-In-the-Loop (HWIL) simulation and sensor test applications. The MAPS is based upon the Texas Instruments Digital Micromirror Device (DMD) which has been modified to project high resolution, realistic imagery suitable for testing sensors and seekers operating in the UV, visible, NIR, and IR wavebands. Since the introduction of the first MAPS in 2001, OSC has continued to improve the technology and develop systems for new projection and Electro-Optical (E-O) test applications. This paper reviews the basic MAPS design and performance capabilities. We also present example projectors and E-O test sets designed and fabricated by OSC in the last 7 years. Finally, current research efforts and new applications of the MAPS technology are discussed.

  14. Novel carbon dioxide gas sensor based on infrared absorption

    NASA Astrophysics Data System (ADS)

    Zhang, Guangjun; Lui, Junfang; Yuan, Mei

    2000-08-01

    The feasibility of sensing carbon dioxide with a IR single- beam optical structure is studied, and a novel carbon dioxide gas sensor based on IR absorption is achieved. Applying the Lambert-Beer law and some key techniques such as current stabilization for IR source, using a high-quality IR detector, and data compensation for the influences of ambience temperature and atmosphere total pressure, the sensor can measure carbon dioxide with high precision and efficiency. The mathematical models for providing temperature and pressure compensation for the sensor are established. Moreover the solutions to the models are proposed. Both the models and the solutions to the models are verified via experiments. The sensor possesses the advantages of small volume, light weight, low power consumption, and high reliability. Therefore it can be used in many associated fields, such as environmental protection, processing control, chemical analysis, medical diagnosis, and space environmental and control systems.

  15. Near infrared spectroscopy for fibre based gas detection

    NASA Astrophysics Data System (ADS)

    Stewart, George; Johnstone, Walter; Thursby, Graham; Culshaw, Brian

    2010-04-01

    Gas sensing systems based on fibre optic linked near infra red absorption cells are potentially a flexible and effective tool for monitoring accumulations of hazardous and noxious gases in enclosed areas such as tunnels and mines. Additionally the same baseline technology is readily modified to measure concentrations of hydrocarbon fuels - notably but not exclusively methane, and monitoring emissions of greenhouse gases. Furthermore the system can be readily implemented to provide intrinsically safe monitoring over extensive areas at up to ~250 points from a single interrogation unit. In this paper we review our work on fibre coupled gas sensing systems. We outline the basic principles through which repeatable and accurate self calibrating gas measurements may be realised, including the recover of detailed line shapes for non contact temperature and / or pressure measurements in addition to concentration assessments in harsh environments. We also outline our experience in using these systems in extensive networks operating under inhospitable conditions over extended periods extending to several years.

  16. The virtual microscope.

    PubMed

    Catalyürek, Umit; Beynon, Michael D; Chang, Chialin; Kurc, Tahsin; Sussman, Alan; Saltz, Joel

    2003-12-01

    We present the design and implementation of the Virtual Microscope, a software system employing a client/server architecture to provide a realistic emulation of a high power light microscope. The system provides a form of completely digital telepathology, allowing simultaneous access to archived digital slide images by multiple clients. The main problem the system targets is storing and processing the extremely large quantities of data required to represent a collection of slides. The Virtual Microscope client software runs on the end user's PC or workstation, while database software for storing, retrieving and processing the microscope image data runs on a parallel computer or on a set of workstations at one or more potentially remote sites. We have designed and implemented two versions of the data server software. One implementation is a customization of a database system framework that is optimized for a tightly coupled parallel machine with attached local disks. The second implementation is component-based, and has been designed to accommodate access to and processing of data in a distributed, heterogeneous environment. We also have developed caching client software, implemented in Java, to achieve good response time and portability across different computer platforms. The performance results presented show that the Virtual Microscope systems scales well, so that many clients can be adequately serviced by an appropriately configured data server.

  17. Model-based estimation of microscopic anisotropy using diffusion MRI: a simulation study.

    PubMed

    Ianuş, Andrada; Drobnjak, Ivana; Alexander, Daniel C

    2016-05-01

    Non-invasive estimation of cell size and shape is a key challenge in diffusion MRI. This article presents a model-based approach that provides independent estimates of pore size and eccentricity from diffusion MRI data. The technique uses a geometric model of finite cylinders with gamma-distributed radii to represent pores of various sizes and elongations. We consider both macroscopically isotropic substrates and substrates of semi-coherently oriented anisotropic pores and we use Monte Carlo simulations to generate synthetic data. We compare the sensitivity of single and double diffusion encoding (SDE and DDE) sequences to the size distribution and eccentricity, and further analyse different protocols of DDE sequences with parallel and/or perpendicular pairs of gradients. We show that explicitly accounting for size distribution is necessary for accurate microstructural parameter estimates, and a model that assumes a single size yields biased eccentricity values. We also find that SDE sequences support estimates, although DDE sequences with mixed parallel and perpendicular gradients enhance accuracy. In the case of macroscopically anisotropic substrates, this model-based approach can be extended to a rotationally invariant framework to provide features of pore shape (specifically eccentricity) in the presence of size distribution and orientation dispersion. PMID:27003223

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

    PubMed

    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

  19. System design and new applications for atomic force microscope based on tunneling

    NASA Astrophysics Data System (ADS)

    Wang, X.; Liu, A. P.; Yang, X. H.

    2015-09-01

    The design of atomic force microscopy (AFM) with high resolution is introduced in this paper. Mainly, we have developed the system design of the apparatus based on tunneling. AFM.IPC-208B, this kind of apparatus combines scanning tunnel microscopy (STM) and AFM availability, and its lens body with original frame enhances the capability of the machine. In order to analyze the performance of AFM.IPC-208B, as a new tool in the field of Life Science, we make use of the system to study natural mica and molecular protein structures of Cattle-insulin and human antibody immunoglobulin G (IgG) coupled with staphylococcus protein A (SPA). As the results of new applications, the resolution of AFM.IPC-208B is proved to be 0.1 nm, and these nanometer measurement results provide much valuable information for the study of small molecular proteins and HIV experiments.

  20. Penetration of resin-based materials into initial erosion lesion: A confocal microscopic study.

    PubMed

    Ionta, Franciny Querobim; Boteon, Ana Paula; Moretto, Marcelo Juliano; Júnior, Odair Bim; Honório, Heitor Marques; Silva, Thiago Cruvinel; Wang, Linda; Rios, Daniela

    2016-02-01

    The application of resin-based materials is an alternative of treatment for eroded lesions. Nevertheless, there are no studies about the penetration of these materials into eroded lesion, which might affect its adhesion. Therefore, this study evaluated the penetration of four resin-based materials, with and without enamel etching. By using an in vitro protocol, types of treatment were studied at five levels (AdheSE(®) , Tetric N-Bond(®) , Single Bond 2(®) , Helioseal Clear(®) , Icon(®) ) and types of enamel etching in two levels (with and without). Materials were stained with 0.02 mg/mL ethanolic solution of tetramethylrhodamine isothiocyanate. Bovine enamel samples (4 × 4 mm) were immersed in 0.01 M HCl, pH 2.3, for 30 seconds to produce initial eroded lesions. Afterward, the materials were applied on half of sample enamel surface following the manufacturer's instructions. On the other half of sample, the materials were applied without etching the enamel. Materials penetration into the enamel was assessed by Confocal Laser Scanning Microscopy on reflection and fluorescence modes. The penetration depth (PD) was measured using ImageJ software. Data were analyzed by two-way ANOVA and Tukey test (P < 0.05). Regardless of the material, etched enamel resulted in higher PD than non-etched (P < 0.05). Icon(®) showed the highest PD in enamel followed by Helioseal Clear(®) (P < 0.05), with significant difference between them (P < 0.05) and no difference was found among AdheSE(®) , Tetric N-Bond(®) , and Single Bond 2(®) (P > 0.05). It can be concluded that prior enamel etching increased the materials penetration into eroded enamel and the Icon(®) -infiltrant presented highest penetration.

  1. Microscopic origin of read current noise in TaOx-based resistive switching memory by ultra-low temperature measurement

    NASA Astrophysics Data System (ADS)

    Pan, Yue; Cai, Yimao; Liu, Yefan; Fang, Yichen; Yu, Muxi; Tan, Shenghu; Huang, Ru

    2016-04-01

    TaOx-based resistive random access memory (RRAM) attracts considerable attention for the development of next generation nonvolatile memories. However, read current noise in RRAM is one of the critical concerns for storage application, and its microscopic origin is still under debate. In this work, the read current noise in TaOx-based RRAM was studied thoroughly. Based on a noise power spectral density analysis at room temperature and at ultra-low temperature of 25 K, discrete random telegraph noise (RTN) and continuous average current fluctuation (ACF) are identified and decoupled from the total read current noise in TaOx RRAM devices. A statistical comparison of noise amplitude further reveals that ACF depends strongly on the temperature, whereas RTN is independent of the temperature. Measurement results combined with conduction mechanism analysis show that RTN in TaOx RRAM devices arises from electron trapping/detrapping process in the hopping conduction, and ACF is originated from the thermal activation of conduction centers that form the percolation network. At last, a unified model in the framework of hopping conduction is proposed to explain the underlying mechanism of both RTN and ACF noise, which can provide meaningful guidelines for designing noise-immune RRAM devices.

  2. Flexible infrared detectors based on p-n junctions of multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Huang, Zhenlong; Gao, Min; Yan, Zhuocheng; Pan, Taisong; Liao, Feiyi; Lin, Yuan

    2016-05-01

    Different types of multi-walled carbon nanotubes (CNTs), synthesized by chemical vapor deposition, are used to fabricate infrared (IR) detectors on flexible substrates based on CNT p-n junctions. It is found that this kind of detector is sensitive to infrared signals with a power density as low as 90 μW mm-2 even at room temperature. Besides, unlike other devices, the detector with this unique structure can be bent for 100 cycles without any damage and its functionality does not degenerate once it recovers to the initial state. The results give a good reference for developing efficient, low-cost, and flexible IR detectors.Different types of multi-walled carbon nanotubes (CNTs), synthesized by chemical vapor deposition, are used to fabricate infrared (IR) detectors on flexible substrates based on CNT p-n junctions. It is found that this kind of detector is sensitive to infrared signals with a power density as low as 90 μW mm-2 even at room temperature. Besides, unlike other devices, the detector with this unique structure can be bent for 100 cycles without any damage and its functionality does not degenerate once it recovers to the initial state. The results give a good reference for developing efficient, low-cost, and flexible IR detectors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08791k

  3. Gaussian mixture model-based gradient field reconstruction for infrared image detail enhancement and denoising

    NASA Astrophysics Data System (ADS)

    Zhao, Fan; Zhao, Jian; Zhao, Wenda; Qu, Feng

    2016-05-01

    Infrared images are characterized by low signal-to-noise ratio and low contrast. Therefore, the edge details are easily immerged in the background and noise, making it much difficult to achieve infrared image edge detail enhancement and denoising. This article proposes a novel method of Gaussian mixture model-based gradient field reconstruction, which enhances image edge details while suppressing noise. First, by analyzing the gradient histogram of noisy infrared image, Gaussian mixture model is adopted to simulate the distribution of the gradient histogram, and divides the image information into three parts corresponding to faint details, noise and the edges of clear targets, respectively. Then, the piecewise function is constructed based on the characteristics of the image to increase gradients of faint details and suppress gradients of noise. Finally, anisotropic diffusion constraint is added while visualizing enhanced image from the transformed gradient field to further suppress noise. The experimental results show that the method possesses unique advantage of effectively enhancing infrared image edge details and suppressing noise as well, compared with the existing methods. In addition, it can be used to effectively enhance other types of images such as the visible and medical images.

  4. A new method to inverse soil moisture based on thermal infrared and passive microwave remote sensing

    NASA Astrophysics Data System (ADS)

    Zhou, Zhuang; Kou, Xiaokang; Zhao, Shaojie; Jiang, Lingmei

    2014-11-01

    Soil moisture is one of the main factors in the water, energy and carbon cycles. It constitutes a major uncertainty in climate and hydrological models. By now, passive microwave remote sensing and thermal infrared remote sensing technology have been used to obtain and monitor soil moisture. However, as the resolution of passive microwave remote sensing is very low and the thermal infrared remote sensing method fails to provide soil temperature on cloudy days, it is hard to monitor the soil moisture accurately. To solve the problem, a new method has been tried in this research. Thermal infrared remote sensing and passive microwave remote sensing technology have been combined based on the delicate experiment. Since the soil moisture retrieved by passive microwave in general represents surface centimeters deep, which is different from deeper soil moisture estimated by thermal inertia method, a relationship between the two depths soil moisture has been established based on the experiment. The results show that there is a good relationship between the soil moisture estimated by passive microwave and thermal infrared remote sensing method. The correlation coefficient is 0.78 and RMSE (root mean square error) is 0.0195 · ?. This research provides a new possible method to inverse soil moisture.

  5. Microscopic biomineralization processes and Zn bioavailability: a synchrotron-based investigation of Pistacia lentiscus L. roots.

    PubMed

    De Giudici, G; Medas, D; Meneghini, C; Casu, M A; Gianoncelli, A; Iadecola, A; Podda, S; Lattanzi, P

    2015-12-01

    Plants growing on polluted soils need to control the bioavailability of pollutants to reduce their toxicity. This study aims to reveal processes occurring at the soil-root interface of Pistacia lentiscus L. growing on the highly Zn-contaminated tailings of Campo Pisano mine (SW Sardinia, Italy), in order to shed light on possible mechanisms allowing for plant adaptation. The study combines conventional X-ray diffraction (XRD) and scanning electron microscopy (SEM) with advanced synchrotron-based techniques, micro-X-ray fluorescence mapping (μ-XRF) and X-ray absorption spectroscopy (XAS). Data analysis elucidates a mechanism used by P. lentiscus L. as response to high Zn concentration in soil. In particular, P. lentiscus roots take up Al, Si and Zn from the rhizosphere minerals in order to build biomineralizations that are part of survival strategy of the species, leading to formation of a Si-Al biomineralization coating the root epidermis. XAS analysis rules out Zn binding to organic molecules and indicates that Zn coordinates Si atoms stored in root epidermis leading to the precipitation of an amorphous Zn-silicate. These findings represent a step forward in understanding biological mechanisms and the resulting behaviour of minor and trace elements during plant-soil interaction and will have significant implications for development of phytoremediation techniques.

  6. New Kohn-Sham density functional based on microscopic nuclear and neutron matter equations of state

    NASA Astrophysics Data System (ADS)

    Baldo, M.; Robledo, L. M.; Schuck, P.; Viñas, X.

    2013-06-01

    A new version of the Barcelona-Catania-Paris energy functional is applied to a study of nuclear masses and other properties. The functional is largely based on calculated ab initio nuclear and neutron matter equations of state. Compared to typical Skyrme functionals having 10-12 parameters apart from spin-orbit and pairing terms, the new functional has only 2 or 3 adjusted parameters, fine tuning the nuclear matter binding energy and fixing the surface energy of finite nuclei. An energy rms value of 1.58 MeV is obtained from a fit of these three parameters to the 579 measured masses reported in the Audi and Wapstra [Nucl. Phys. ANUPABL0375-947410.1016/j.nuclphysa.2003.11.003 729, 337 (2003)] compilation. This rms value compares favorably with the one obtained using other successful mean field theories, which range from 1.5 to 3.0 MeV for optimized Skyrme functionals and 0.7 to 3.0 for the Gogny functionals. The other properties that have been calculated and compared to experiment are nuclear radii, the giant monopole resonance, and spontaneous fission lifetimes.

  7. Microscopic biomineralization processes and Zn bioavailability: a synchrotron-based investigation of Pistacia lentiscus L. roots.

    PubMed

    De Giudici, G; Medas, D; Meneghini, C; Casu, M A; Gianoncelli, A; Iadecola, A; Podda, S; Lattanzi, P

    2015-12-01

    Plants growing on polluted soils need to control the bioavailability of pollutants to reduce their toxicity. This study aims to reveal processes occurring at the soil-root interface of Pistacia lentiscus L. growing on the highly Zn-contaminated tailings of Campo Pisano mine (SW Sardinia, Italy), in order to shed light on possible mechanisms allowing for plant adaptation. The study combines conventional X-ray diffraction (XRD) and scanning electron microscopy (SEM) with advanced synchrotron-based techniques, micro-X-ray fluorescence mapping (μ-XRF) and X-ray absorption spectroscopy (XAS). Data analysis elucidates a mechanism used by P. lentiscus L. as response to high Zn concentration in soil. In particular, P. lentiscus roots take up Al, Si and Zn from the rhizosphere minerals in order to build biomineralizations that are part of survival strategy of the species, leading to formation of a Si-Al biomineralization coating the root epidermis. XAS analysis rules out Zn binding to organic molecules and indicates that Zn coordinates Si atoms stored in root epidermis leading to the precipitation of an amorphous Zn-silicate. These findings represent a step forward in understanding biological mechanisms and the resulting behaviour of minor and trace elements during plant-soil interaction and will have significant implications for development of phytoremediation techniques. PMID:26062465

  8. Microscopic evaluation of creep-fatigue interaction in a nickel-based superalloy

    SciTech Connect

    Santella, Michael L; Yamamoto, Masato; Shingledecker, John P; Boehlert, C. J.; Ogata, Takashi

    2009-01-01

    In order to verify the applicability of Nickel-based alloy Alloy 263 for the thick component, a series of creep, fatigue and creep-fatigue experiments were carried out. To investigate the detailed damage process under the creep-fatigue condition, simple aged, crept, fatigued, and creep-fatigued specimens were subjected to electron back scattering diffraction (EBSD) pattern observation in the SEM. While the simple aged and fatigued specimens showed no remarkable local change in orientation (less than 1deg), the crept specimen exhibited inhomogeneous change of crystallographic orientation, at most 5 degrees, within the grains. This shows that the creep strain is inhomogeneously distributed in the grains due to the effect of relative constraint among the grains. The creep-fatigued specimen exhibited similar local inhomogeniety in strain distribution compared to the crept sample near the center of the grains. However, the creep-fatigued specimen showed remarkable local change in orientation at the vicinity of grain boundaries up to 15 degrees, indicating the occurrence of high strain concentration nearby the grain boundaries. A detailed observation of creep-fatigue damage evolution process in SEM revealed that the inhomogeneous grain deformation precedes the remarkable inhomogeneous deformation nearby the grain boundaries, and followed by the grain boundary cracking.

  9. An improved fusion algorithm for infrared and visible images based on multi-scale transform

    NASA Astrophysics Data System (ADS)

    Li, He; Liu, Lei; Huang, Wei; Yue, Chao

    2016-01-01

    In this paper, an improved fusion algorithm for infrared and visible images based on multi-scale transform is proposed. First of all, Morphology-Hat transform is used for an infrared image and a visible image separately. Then two images were decomposed into high-frequency and low-frequency images by contourlet transform (CT). The fusion strategy of high-frequency images is based on mean gradient and the fusion strategy of low-frequency images is based on Principal Component Analysis (PCA). Finally, the final fused image is obtained by using the inverse contourlet transform (ICT). The experiments and results demonstrate that the proposed method can significantly improve image fusion performance, accomplish notable target information and high contrast and preserve rich details information at the same time.

  10. Femtosecond photoelectron point projection microscope

    SciTech Connect

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-10-15

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  11. Quantitative characterization of carbon/carbon composites matrix texture based on image analysis using polarized light microscope.

    PubMed

    Li, Yixian; Qi, Lehua; Song, Yongshan; Hou, Xianghui; Li, Hejun

    2015-10-01

    A quantitative characteristic method was proposed for characterizing the matrix texture of carbon/carbon(C/C) composites, which determined the mechanical and physical properties of C/C composites. Based on the cloud theory that was commonly used for uncertain reasoning and the transformation between quantitative and qualitative characterization, so the relationship between the extinction angle and texture types was built by the cloud models for describing the texture of microstructure, moreover, linguistic controllers were established to analyze the matrix texture in accordance with the features of the polarized light microscope (PLM) image. On this basis, the extinction angle could be calculated from the PLM image of the C/C composites. In contrast to the results of measurement, the errors between calculative values and measured values were maintained 1-2° in basically. Meanwhile, the PLM image of C/C composites was segmented by the component, in particular, the matrix with mixed textures was further segmented by the difference of texture. It means that the quantitative characterization of C/C composites matrix based on single PLM image has been realized.

  12. A pressure gauge based on gas density measurement from analysis of the thermal noise of an atomic force microscope cantilever

    SciTech Connect

    Seo, Dongjin; Ducker, William A.; Paul, Mark R.

    2012-05-15

    We describe a gas-density gauge based on the analysis of the thermally-driven fluctuations of an atomic force microscope (AFM) cantilever. The fluctuations are modeled as a ring-down of a simple harmonic oscillator, which allows fitting of the resonance frequency and damping of the cantilever, which in turn yields the gas density. The pressure is obtained from the density using the known equation of state. In the range 10-220 kPa, the pressure readings from the cantilever gauge deviate by an average of only about 5% from pressure readings on a commercial gauge. The theoretical description we use to determine the pressure from the cantilever motion is based upon the continuum hypothesis, which sets a minimum pressure for our analysis. It is anticipated that the cantilever gauge could be extended to measure lower pressures given a molecular theoretical description. Alternatively, the gauge could be calibrated for use in the non-continuum range. Our measurement technique is similar to previous AFM cantilever measurements, but the analysis produces improved accuracy.

  13. Parallel algorithm of real-time infrared image restoration based on total variation theory

    NASA Astrophysics Data System (ADS)

    Zhu, Ran; Li, Miao; Long, Yunli; Zeng, Yaoyuan; An, Wei

    2015-10-01

    Image restoration is a necessary preprocessing step for infrared remote sensing applications. Traditional methods allow us to remove the noise but penalize too much the gradients corresponding to edges. Image restoration techniques based on variational approaches can solve this over-smoothing problem for the merits of their well-defined mathematical modeling of the restore procedure. The total variation (TV) of infrared image is introduced as a L1 regularization term added to the objective energy functional. It converts the restoration process to an optimization problem of functional involving a fidelity term to the image data plus a regularization term. Infrared image restoration technology with TV-L1 model exploits the remote sensing data obtained sufficiently and preserves information at edges caused by clouds. Numerical implementation algorithm is presented in detail. Analysis indicates that the structure of this algorithm can be easily implemented in parallelization. Therefore a parallel implementation of the TV-L1 filter based on multicore architecture with shared memory is proposed for infrared real-time remote sensing systems. Massive computation of image data is performed in parallel by cooperating threads running simultaneously on multiple cores. Several groups of synthetic infrared image data are used to validate the feasibility and effectiveness of the proposed parallel algorithm. Quantitative analysis of measuring the restored image quality compared to input image is presented. Experiment results show that the TV-L1 filter can restore the varying background image reasonably, and that its performance can achieve the requirement of real-time image processing.

  14. Wavelet-Based Visible and Infrared Image Fusion: A Comparative Study.

    PubMed

    Sappa, Angel D; Carvajal, Juan A; Aguilera, Cristhian A; Oliveira, Miguel; Romero, Dennis; Vintimilla, Boris X

    2016-01-01

    This paper evaluates different wavelet-based cross-spectral image fusion strategies adopted to merge visible and infrared images. The objective is to find the best setup independently of the evaluation metric used to measure the performance. Quantitative performance results are obtained with state of the art approaches together with adaptations proposed in the current work. The options evaluated in the current work result from the combination of different setups in the wavelet image decomposition stage together with different fusion strategies for the final merging stage that generates the resulting representation. Most of the approaches evaluate results according to the application for which they are intended for. Sometimes a human observer is selected to judge the quality of the obtained results. In the current work, quantitative values are considered in order to find correlations between setups and performance of obtained results; these correlations can be used to define a criteria for selecting the best fusion strategy for a given pair of cross-spectral images. The whole procedure is evaluated with a large set of correctly registered visible and infrared image pairs, including both Near InfraRed (NIR) and Long Wave InfraRed (LWIR). PMID:27294938

  15. System design and description of infrared simulator system based on the multidimensional flight table

    NASA Astrophysics Data System (ADS)

    Huang, Chong; Chen, Haiqing; Li, Jun; Yang, Zhengang; Zhao, Shuang

    2008-12-01

    This paper deals with the simulation for the army aviation and missile command at the thermal infrared range scale from 2.0 to 4.9μm. The infrared simulator system based on the multidimensional flight table(ISSBMFT) is the significant part of hardware - in - the - loop (HWIL) simulation system for controlling and guiding weapon systems with infrared seekers. It emphasizes on the infrared scene of HWIL simulation experimentation for controlling and guiding weapon and provides a realistic environment of combat with target/jamming which owns the specific properties of radiant spectrum, entrance angle and target's relative distance variation. Optical system is the basis of the characteristics of the simulator. In the system, three-beam structure is put forward which will make the optical path equal. Through settling attenuators, filters, and polaroids in the beams, which modulates the transmittance, the energy proportion is simulated, so as wave energy and the entrance angle. So we can simulate one target and two different forms of jamming through various distance and conformations. Radiant system and controlling system is the guarantee of the simulation. Calculation of energy and the method of controlling is depicted in the article.

  16. Non-uniformity correction for infrared focal plane array with image based on neural network algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Yu, Junsheng; Zhou, Yun; Xing, Yanmin; Jiang, Yadong

    2010-10-01

    Non-uniformity response of detectors based on infrared focal plane array (IRFPA) result in fixed pattern noise (FPN) due to detector materials' non-uniformity and fabrication technology. Once fixed pattern noise added to the infrared image, focal plane image quality will have a serious impact. So non-uniformity correction (NUC) is a key technology in IRFPA application. This paper briefly introduces the traditional neural network algorithm and puts forward an improved algorithm for the neural network algorithm for NUC of infrared focal plane arrays. The main improvement is focused on the estimation method of desired image. The algorithm is used to analyze the image array, correcting data on the array both in space and in time. The correction image in the text is from the infrared data sequence which is more successful of three frames of data obtained. It was found that the estimated image corrected by new algorithm is closer to real image than the estimated image corrected by other algorithm. Moreover, we simulated the new proposed algorithm using Matlab. The results showed that the method of spatial and temporal co-correction of the images is more realistic than the original image.

  17. Wavelet-Based Visible and Infrared Image Fusion: A Comparative Study

    PubMed Central

    Sappa, Angel D.; Carvajal, Juan A.; Aguilera, Cristhian A.; Oliveira, Miguel; Romero, Dennis; Vintimilla, Boris X.

    2016-01-01

    This paper evaluates different wavelet-based cross-spectral image fusion strategies adopted to merge visible and infrared images. The objective is to find the best setup independently of the evaluation metric used to measure the performance. Quantitative performance results are obtained with state of the art approaches together with adaptations proposed in the current work. The options evaluated in the current work result from the combination of different setups in the wavelet image decomposition stage together with different fusion strategies for the final merging stage that generates the resulting representation. Most of the approaches evaluate results according to the application for which they are intended for. Sometimes a human observer is selected to judge the quality of the obtained results. In the current work, quantitative values are considered in order to find correlations between setups and performance of obtained results; these correlations can be used to define a criteria for selecting the best fusion strategy for a given pair of cross-spectral images. The whole procedure is evaluated with a large set of correctly registered visible and infrared image pairs, including both Near InfraRed (NIR) and Long Wave InfraRed (LWIR). PMID:27294938

  18. The infrared target enhancement method based on optimization at the whole directional polarization

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Li, Ji-Cheng; Wang, Sha-fei; Gong, Ting

    2016-03-01

    An infrared target enhancement method based on optimization in the whole directional polarization is studied in this paper. By using the description relationship between the stokes vector of incident light and the intensity of emergent light, the analytical formula between the intensity of emergent light and the polarizing angle is deduced, and thus virtually derives the intensity of emergent light from 0°to 360° polarizing angle. Then according to the criterion of maximum contrast between target and background, the searching of optimal polarizing angle is iteratively realized, and finally gets the enhanced infrared target image. The feasibility and validity of the algorithm are validated by using real long wave infrared (LWIR) polarization images of target. Experimental results show that, the enhanced image using proposed algorithm possesses obvious suppression effect of background clutter, and the quantitative evaluation under two kinds of image quality evaluation indexes of average gradient and image entropy also validates the effectiveness of our algorithm in infrared target enhancement.

  19. Wavelet-Based Visible and Infrared Image Fusion: A Comparative Study.

    PubMed

    Sappa, Angel D; Carvajal, Juan A; Aguilera, Cristhian A; Oliveira, Miguel; Romero, Dennis; Vintimilla, Boris X

    2016-06-10

    This paper evaluates different wavelet-based cross-spectral image fusion strategies adopted to merge visible and infrared images. The objective is to find the best setup independently of the evaluation metric used to measure the performance. Quantitative performance results are obtained with state of the art approaches together with adaptations proposed in the current work. The options evaluated in the current work result from the combination of different setups in the wavelet image decomposition stage together with different fusion strategies for the final merging stage that generates the resulting representation. Most of the approaches evaluate results according to the application for which they are intended for. Sometimes a human observer is selected to judge the quality of the obtained results. In the current work, quantitative values are considered in order to find correlations between setups and performance of obtained results; these correlations can be used to define a criteria for selecting the best fusion strategy for a given pair of cross-spectral images. The whole procedure is evaluated with a large set of correctly registered visible and infrared image pairs, including both Near InfraRed (NIR) and Long Wave InfraRed (LWIR).

  20. A robust infrared dim target detection method based on template filtering and saliency extraction

    NASA Astrophysics Data System (ADS)

    Wang, Wenguang; Li, Chenming; Shi, Jianing

    2015-11-01

    Dim target detection in infrared image with complex background and low signal-clutter ratio (SCR) is a significant and difficult task in the infrared target tracking system. A robust infrared dim target detection method based on template filtering and saliency extraction is proposed in this paper. The weighted gray map is obtained from the infrared image to highlight the target which is brighter than its neighbors and has weak correlation with its background. The target saliency map is then calculated by phase spectrum of Fourier Transform, so that the dim target detection could be converted to salient region extraction. The potential targets are finally extracted by combining the two maps. Moreover, position discrimination between targets in the two maps is used to exclude the false alarms and extract the targets. Experimental results on measured images indicate that our method is feasible, adaptable and robust in different backgrounds. The ROC (Receiver Operating Characteristic) curves obtained from the simulated images demonstrate the proposed method outperforms some existing typical methods in both detection rate and false alarm rate, for target detection with low SCR.

  1. Low Size, Weight and Power Concept for Mid-Wave Infrared Optical Communication Transceivers Based on Quantum Cascade Lasers

    NASA Technical Reports Server (NTRS)

    Luzhanskiy, Edward; Choa, Fow-Sen; Merritt, Scott; Yu, Anthony; Krainak, Michael

    2015-01-01

    The low complexity, low size, weight and power Mid-Wavelength Infra-Red optical communications transceiver concept presented, realized and tested in the laboratory environment. Resilience to atmospheric impairments analyzed with simulated turbulence. Performance compared to typical telecom based Short Wavelength Infra-Red transceiver.

  2. Irradiance-based emissivity correction in infrared thermography for electronic applications.

    PubMed

    Vellvehi, M; Perpiñà, X; Lauro, G L; Perillo, F; Jordà, X

    2011-11-01

    This work analyzes, discusses, and proposes a solution to the problem of the emissivity correction present in infrared thermography when coatings with known emissivity cannot be deposited on the inspected surface. It is shown that the conventional technique based on two reference thermal images and the linearization of the blackbody radiation dependence on temperature is not a reliable and accurate solution when compared with the coating procedure. In this scenario, a new approach based on the direct processing of the output signal of the infrared camera (which is proportional to the detected irradiance) is proposed to obtain an accurate emissivity and surrounding reflections map, perfectly compensating the thermal maps. The results obtained have been validated using a module as a test vehicle containing two thermal test chips which incorporate embedded temperature sensors.

  3. Mid-wave interband cascade infrared photodetectors based on GaInAsSb absorbers

    NASA Astrophysics Data System (ADS)

    Lei, Lin; Li, Lu; Lotfi, Hossein; Jiang, Yuchao; Yang, Rui Q.; Johnson, Matthew B.; Lubyshev, Dmitri; Qiu, Yueming; Fastenau, Joel M.; Liu, Amy W. K.

    2016-10-01

    In this work, we report the demonstration of quaternary GaInAsSb-based mid-wavelength infrared photodetectors with cutoff wavelengths longer than 4 μm at 300 K. Both interband cascade infrared photodetector (ICIP) with a three-stage discrete absorber architecture and conventional one-stage detector structures have been grown by molecular beam epitaxy and investigated in experiments for their electrical and optical properties. High absorption coefficient and gain were observed in both detector structures. The three-stage ICIPs had superior carrier transport over the one-stage detectors. A detectivity as high as 1.0 × 109 cm Hz1/2 W-1 was achieved at 3.3 μm for both one- and three-stage detectors under zero bias at 300 K. The implications of these results are discussed along with potential of GaInAsSb-based ICIPs for high-speed applications.

  4. Fiber based infrared lasers and their applications in medicine, spectroscopy and metrology

    NASA Astrophysics Data System (ADS)

    Alexander, Vinay Varkey

    In my thesis, I have demonstrated the development of fiber based infrared lasers and devices for applications in medicine, spectroscopy and metrology. One of the key accomplishments presented in this thesis for medical applications is the demonstration of a focused infrared laser to perform renal denervation both in vivo and in vitro. Hypertension is a significant health hazard in the US and throughout the world, and the laser based renal denervation procedure may be a potential treatment for resistant hypertension. Compared to current treatment modalities, lasers may be able to perform treatments with lesser collateral tissue damage and quicker treatment times helping to reduce patient discomfort and pain. An additional medical application demonstrated in this thesis is the use of infrared fiber lasers to damage sebaceous glands in human skin as a potential treatment for acne. Another significant work presented in this thesis is a field trial performed at the Wright Patterson Air Force Base using a Short Wave Infrared (SWIR) Supercontinuum (SC) laser as an active illumination source for long distance reflectance measurements. In this case, an SC laser developed as part of this thesis is kept on a 12 story tower and propagated through the atmosphere to a target kept 1.6 km away and used to perform spectroscopy measurements. In the future this technology may permit 24/7 surveillance based on looking for the spectral signatures of materials. Beyond applications in defense, this technology may have far reaching commercial applications as well, including areas such as oil and natural resources exploration. Beyond these major contributions to the state-of-the-art, this thesis also describes other significant studies such as power scalability of SWIR SC sources and non-invasive measurement of surface roughness.

  5. Infrared small target detection via line-based reconstruction and entropy-induced suppression

    NASA Astrophysics Data System (ADS)

    Shang, Ke; Sun, Xiao; Tian, Jinwen; Li, Yansheng; Ma, Jiayi

    2016-05-01

    This paper proposes a novel infrared small target detection method which is composed of two stages. The first stage is implemented by line-based reconstruction for suppressing the background clutter, and the second stage is induced by information entropy for further standing out the targets. Compared with the state-of-the-art approaches, the proposed approach is able to achieve better performance in terms of efficiency and accuracy.

  6. Benzodipyrrole-based Donor-Acceptor-type Boron Complexes as Tunable Near-infrared-Absorbing Materials.

    PubMed

    Nakamura, Tomoya; Furukawa, Shunsuke; Nakamura, Eiichi

    2016-07-20

    Benzodipyrrole-based donor-acceptor boron complexes were designed and synthesized as near-infrared-absorbing materials. The electron-rich organic framework combined with the Lewis acidic boron co-ordination enabled us to tune the LUMO energy level and the HOMO-LUMO gap (i.e.,the absorption wavelength) by changing the organic acceptor units, the number of boron atoms, and the substituents on the boron atoms.

  7. Far infrared supplement: Catalog of infrared observations

    NASA Technical Reports Server (NTRS)

    Gezari, D. Y.; Schmitz, M.; Mead, J. M.

    1982-01-01

    The development of a new generation of orbital, airborne and ground-based infrared astronomical observatory facilities, including the infrared astronomical satellite (IRAS), the cosmic background explorer (COBE), the NASA Kuiper airborne observatory, and the NASA infrared telescope facility, intensified the need for a comprehensive, machine-readable data base and catalog of current infrared astronomical observations. The Infrared Astronomical Data Base and its principal data product, this catalog, comprise a machine-readable library of infrared (1 micrometer to 1000 micrometers) astronomical observations published in the scientific literature since 1965.

  8. Design of infrared signal processing system based on heterogeneous MPSoC

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Tang, Xinyi

    2015-02-01

    As one of the most significant parts in the development of the next generation infrared detection system, the infrared signal processing system requires the ability of real-time processing and high speed data transmission. A newly developed real-time signal processing system for infrared detecting based on the heterogeneous multiprocessor system on chip (MPSoC) is proposed in this paper. The device follows the architecture of Xilinx Zynq platform, integrating a feature rich dual-core ARM and Xilinx FPGA in a single chip, built on the 28nm high-k metal gate process technology. According to our design, the FPGA fabric portion retains all the programmable flexibility to drive the infrared detector and acquire data from ADC, with registers parallel operations to implement hardware acceleration. Furthermore, the FPGA fabric is connected to the ARM centered processor unit through multiple high performance interfaces, confirming high bandwidth communication and high speed data transmission between the two portions. Finally, the dual core ARM takes charge of the infrared signal processing system in general. One of the CPUs controls separate hardware modules and maintains the GUI for user interaction. The other responds to the dedicated system commands and external interrupts to update system parameters simultaneously. The integration of ARM and FPGA provides levels of performance that two-chip solutions cannot match due to their limited I/O bandwidth, loose coupling and power budgets. Experiments show that the architecture of heterogeneous MPSoC enhances the efficiency of memory controller and increases the speed of data transmission, approaching the theoretical value of the interfaces bandwidth.

  9. Theoretical investigation of all-metal-based mushroom plasmonic metamaterial absorbers at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Kimata, Masafumi

    2015-12-01

    High-performance wavelength-selective infrared (IR) sensors require small pixel structures, a low-thermal mass, and operation in the middle-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) regions for multicolor IR imaging. All-metal-based mushroom plasmonic metamaterial absorbers (MPMAs) were investigated theoretically and were designed to enhance the performance of wavelength-selective uncooled IR sensors. All components of the MPMAs are based on thin layers of metals such as Au without oxide insulators for increased absorption. The absorption properties of the MPMAs were investigated by rigorous coupled-wave analysis. Strong wavelength-selective absorption is realized over a wide range of MWIR and LWIR wavelengths by the plasmonic resonance of the micropatch and the narrow-gap resonance, without disturbance from the intrinsic absorption of oxide insulators. The absorption wavelength is defined mainly by the micropatch size and is longer than its period. The metal post width has less impact on the absorption properties and can maintain single-mode operation. Through-holes can be formed on the plate area to reduce the thermal mass. A small pixel size with reduced thermal mass and wideband single-mode operation can be realized using all-metal-based MPMAs.

  10. The ship-borne infrared searching and tracking system based on the inertial platform

    NASA Astrophysics Data System (ADS)

    Li, Yan; Zhang, Haibo

    2011-08-01

    As a result of the radar system got interferenced or in the state of half silent ,it can cause the guided precision drop badly In the modern electronic warfare, therefore it can lead to the equipment depended on electronic guidance cannot strike the incoming goals exactly. It will need to rely on optoelectronic devices to make up for its shortcomings, but when interference is in the process of radar leading ,especially the electro-optical equipment is influenced by the roll, pitch and yaw rotation ,it can affect the target appear outside of the field of optoelectronic devices for a long time, so the infrared optoelectronic equipment can not exert the superiority, and also it cannot get across weapon-control system "reverse bring" missile against incoming goals. So the conventional ship-borne infrared system unable to track the target of incoming quickly , the ability of optoelectronic rivalry declines heavily.Here we provide a brand new controlling algorithm for the semi-automatic searching and infrared tracking based on inertial navigation platform. Now it is applying well in our XX infrared optoelectronic searching and tracking system. The algorithm is mainly divided into two steps: The artificial mode turns into auto-searching when the deviation of guide exceeds the current scene under the course of leading for radar.When the threshold value of the image picked-up is satisfied by the contrast of the target in the searching scene, the speed computed by using the CA model Least Square Method feeds back to the speed loop. And then combine the infrared information to accomplish the closed-loop control of the infrared optoelectronic system tracking. The algorithm is verified via experiment. Target capturing distance is 22.3 kilometers on the great lead deviation by using the algorithm. But without using the algorithm the capturing distance declines 12 kilometers. The algorithm advances the ability of infrared optoelectronic rivalry and declines the target capturing

  11. Electron tomography of HEK293T cells using scanning electron microscope-based scanning transmission electron microscopy.

    PubMed

    You, Yun-Wen; Chang, Hsun-Yun; Liao, Hua-Yang; Kao, Wei-Lun; Yen, Guo-Ji; Chang, Chi-Jen; Tsai, Meng-Hung; Shyue, Jing-Jong

    2012-10-01

    Based on a scanning electron microscope operated at 30 kV with a homemade specimen holder and a multiangle solid-state detector behind the sample, low-kV scanning transmission electron microscopy (STEM) is presented with subsequent electron tomography for three-dimensional (3D) volume structure. Because of the low acceleration voltage, the stronger electron-atom scattering leads to a stronger contrast in the resulting image than standard TEM, especially for light elements. Furthermore, the low-kV STEM yields less radiation damage to the specimen, hence the structure can be preserved. In this work, two-dimensional STEM images of a 1-μm-thick cell section with projection angles between ±50° were collected, and the 3D volume structure was reconstructed using the simultaneous iterative reconstructive technique algorithm with the TomoJ plugin for ImageJ, which are both public domain software. Furthermore, the cross-sectional structure was obtained with the Volume Viewer plugin in ImageJ. Although the tilting angle is constrained and limits the resulting structural resolution, slicing the reconstructed volume generated the depth profile of the thick specimen with sufficient resolution to examine cellular uptake of Au nanoparticles, and the final position of these nanoparticles inside the cell was imaged.

  12. Piezoelectric bimorph-based scanner in the tip-scan mode for high speed atomic force microscope

    NASA Astrophysics Data System (ADS)

    Zhao, Jianyong; Gong, Weitao; Cai, Wei; Shang, Guangyi

    2013-08-01

    A piezoelectric bimorph-based scanner operating in tip-scan mode for high speed atomic force microscope (AFM) is first presented. The free end of the bimorph is used for fixing an AFM cantilever probe and the other one is mounted on the AFM head. The sample is placed on the top of a piezoelectric tube scanner. High speed scan is performed with the bimorph that vibrates at the resonant frequency, while slow scanning is carried out by the tube scanner. The design and performance of the scanner is discussed and given in detailed. Combined with a commercially available data acquisition system, a high speed AFM has been built successfully. By real-time observing the deformation of the pores on the surface of a commercial piezoelectric lead zirconate titanate (PZT-5) ceramics under electric field, the dynamic imaging capability of the AFM is demonstrated. The results show that the notable advantage of the AFM is that dynamic process of the sample with large dimensions can be easily investigated. In addition, this design could provide a way to study a sample in real time under the given experimental condition, such as under an external electric field, on a heating stage, or in a liquid cell.

  13. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.

    PubMed

    Ogura, Toshihiko

    2009-08-01

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  14. Lab-on-DVD: standard DVD drives as a novel laser scanning microscope for image based point of care diagnostics.

    PubMed

    Ramachandraiah, Harisha; Amasia, Mary; Cole, Jackie; Sheard, Paul; Pickhaver, Simon; Walker, Chris; Wirta, Valtteri; Lexow, Preben; Lione, Richard; Russom, Aman

    2013-04-21

    We present a novel "Lab-on-DVD" system and demonstrate its capability for rapid and low-cost HIV diagnostics by counting CD4+ cells isolated from whole blood. We show that a commercial DVD drive can, with certain modifications, be turned into an improved DVD-based laser scanning microscope (DVD-LSM). The system consists of a multi-layered disposable polymer disc and a modified commercial DVD reader with rotational control for sample handling, temperature control for optimized bioassay, a photodiode array for detection, and software for signal processing and user interface - all the necessary components required for a truly integrated lab-on-a-chip system, with the capability to deliver high-resolution images down to 1 μm in size. Using discs modified with antibodies, we specifically captured CD4+ cells from whole blood, demonstrating single cell resolution imaging. The novel integrated DVD platform with sub-micron image resolution brings, for the first time, affordable cellular diagnostic testing to the point-of-care and should be readily applicable at resource-limited settings.

  15. In situ, dual-mode monitoring of organ-on-a-chip with smartphone-based fluorescence microscope.

    PubMed

    Cho, Soohee; Islas-Robles, Argel; Nicolini, Ariana M; Monks, Terrence J; Yoon, Jeong-Yeol

    2016-12-15

    The use of organ-on-a-chip (OOC) platforms enables improved simulation of the human kidney's response to nephrotoxic drugs. The standard method of analyzing nephrotoxicity from existing OOC has majorly consisted of invasively collecting samples (cells, lysates, media, etc.) from an OOC. Such disruptive analyses potentiate contamination, disrupt the replicated in vivo environment, and require expertize to execute. Moreover, traditional analyses, including immunofluorescence microscopy, immunoblot, and microplate immunoassay are essentially not in situ and require substantial time, resources, and costs. In the present work, the incorporation of fluorescence nanoparticle immunocapture/immunoagglutination assay into an OOC enabled dual-mode monitoring of drug-induced nephrotoxicity in situ. A smartphone-based fluorescence microscope was fabricated as a handheld in situ monitoring device attached to an OOC. Both the presence of γ-glutamyl transpeptidase (GGT) on the apical brush-border membrane of 786-O proximal tubule cells within the OOC surface, and the release of GGT to the outflow of the OOC were evaluated with the fluorescence scatter detection of captured and immunoagglutinated anti-GGT conjugated nanoparticles. This dual-mode assay method provides a novel groundbreaking tool to enable the internal and external in situ monitoring of the OOC, which may be integrated into any existing OOCs to facilitate their subsequent analyses.

  16. A tuning fork based wide range mechanical characterization tool with nanorobotic manipulators inside a scanning electron microscope

    SciTech Connect

    Acosta, Juan Camilo; Hwang, Gilgueng; Regnier, Stephane; Polesel-Maris, Jerome

    2011-03-15

    This study proposes a tuning fork probe based nanomanipulation robotic system for mechanical characterization of ultraflexible nanostructures under scanning electron microscope. The force gradient is measured via the frequency modulation of a quartz tuning fork and two nanomanipulators are used for manipulation of the nanostructures. Two techniques are proposed for attaching the nanostructure to the tip of the tuning fork probe. The first technique involves gluing the nanostructure for full range characterization whereas the second technique uses van der Waals and electrostatic forces in order to avoid destroying the nanostructure. Helical nanobelts (HNB) are proposed for the demonstration of the setup. The nonlinear stiffness behavior of HNBs during their full range tensile studies is clearly revealed for the first time. Using the first technique, this was between 0.009 N/m for rest position and 0.297 N/m before breaking of the HNB with a resolution of 0.0031 N/m. For the second experiment, this was between 0.014 N/m for rest position and 0.378 N/m before detaching of the HNB with a resolution of 0.0006 N/m. This shows the wide range sensing of the system for potential applications in mechanical property characterization of ultraflexible nanostructures.

  17. A tuning fork based wide range mechanical characterization tool with nanorobotic manipulators inside a scanning electron microscope.

    PubMed

    Acosta, Juan Camilo; Hwang, Gilgueng; Polesel-Maris, Jérôme; Régnier, Stéphane

    2011-03-01

    This study proposes a tuning fork probe based nanomanipulation robotic system for mechanical characterization of ultraflexible nanostructures under scanning electron microscope. The force gradient is measured via the frequency modulation of a quartz tuning fork and two nanomanipulators are used for manipulation of the nanostructures. Two techniques are proposed for attaching the nanostructure to the tip of the tuning fork probe. The first technique involves gluing the nanostructure for full range characterization whereas the second technique uses van der Waals and electrostatic forces in order to avoid destroying the nanostructure. Helical nanobelts (HNB) are proposed for the demonstration of the setup. The nonlinear stiffness behavior of HNBs during their full range tensile studies is clearly revealed for the first time. Using the first technique, this was between 0.009 N/m for rest position and 0.297 N/m before breaking of the HNB with a resolution of 0.0031 N/m. For the second experiment, this was between 0.014 N/m for rest position and 0.378 N/m before detaching of the HNB with a resolution of 0.0006 N/m. This shows the wide range sensing of the system for potential applications in mechanical property characterization of ultraflexible nanostructures.

  18. A tuning fork based wide range mechanical characterization tool with nanorobotic manipulators inside a scanning electron microscope.

    PubMed

    Acosta, Juan Camilo; Hwang, Gilgueng; Polesel-Maris, Jérôme; Régnier, Stéphane

    2011-03-01

    This study proposes a tuning fork probe based nanomanipulation robotic system for mechanical characterization of ultraflexible nanostructures under scanning electron microscope. The force gradient is measured via the frequency modulation of a quartz tuning fork and two nanomanipulators are used for manipulation of the nanostructures. Two techniques are proposed for attaching the nanostructure to the tip of the tuning fork probe. The first technique involves gluing the nanostructure for full range characterization whereas the second technique uses van der Waals and electrostatic forces in order to avoid destroying the nanostructure. Helical nanobelts (HNB) are proposed for the demonstration of the setup. The nonlinear stiffness behavior of HNBs during their full range tensile studies is clearly revealed for the first time. Using the first technique, this was between 0.009 N/m for rest position and 0.297 N/m before breaking of the HNB with a resolution of 0.0031 N/m. For the second experiment, this was between 0.014 N/m for rest position and 0.378 N/m before detaching of the HNB with a resolution of 0.0006 N/m. This shows the wide range sensing of the system for potential applications in mechanical property characterization of ultraflexible nanostructures. PMID:21456797

  19. Development of plenoptic infrared camera using low dimensional material based photodetectors

    NASA Astrophysics Data System (ADS)

    Chen, Liangliang

    Infrared (IR) sensor has extended imaging from submicron visible spectrum to tens of microns wavelength, which has been widely used for military and civilian application. The conventional bulk semiconductor materials based IR cameras suffer from low frame rate, low resolution, temperature dependent and highly cost, while the unusual Carbon Nanotube (CNT), low dimensional material based nanotechnology has been made much progress in research and industry. The unique properties of CNT lead to investigate CNT based IR photodetectors and imaging system, resolving the sensitivity, speed and cooling difficulties in state of the art IR imagings. The reliability and stability is critical to the transition from nano science to nano engineering especially for infrared sensing. It is not only for the fundamental understanding of CNT photoresponse induced processes, but also for the development of a novel infrared sensitive material with unique optical and electrical features. In the proposed research, the sandwich-structured sensor was fabricated within two polymer layers. The substrate polyimide provided sensor with isolation to background noise, and top parylene packing blocked humid environmental factors. At the same time, the fabrication process was optimized by real time electrical detection dielectrophoresis and multiple annealing to improve fabrication yield and sensor performance. The nanoscale infrared photodetector was characterized by digital microscopy and precise linear stage in order for fully understanding it. Besides, the low noise, high gain readout system was designed together with CNT photodetector to make the nano sensor IR camera available. To explore more of infrared light, we employ compressive sensing algorithm into light field sampling, 3-D camera and compressive video sensing. The redundant of whole light field, including angular images for light field, binocular images for 3-D camera and temporal information of video streams, are extracted and

  20. Near-infrared Thermal Emission Detections of a Number of Hot Jupiters and the Systematics of Ground-based Near-infrared Photometry

    NASA Astrophysics Data System (ADS)

    Croll, Bryce; Albert, Loic; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Lafreniere, David; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

    2015-03-01

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K CONT-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations. Based on observations obtained with WIRCam, a joint project of Canada-France-Hawaii Telescope (CFHT), Taiwan, Korea, Canada, France, at the CFHT, which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

  1. Microscopes and ocular infections.

    PubMed

    Olcerst, R B

    1987-05-01

    Environmental microbial assays of industrial microscope eyepieces were conducted following reports of multiple intershift ocular infections. Pathogenic Staphylococcus aureus was identified among the microorganisms cultured. This paper suggests that direct contact with industrial microscope eyepieces provides a potentially significant route of transmission of both bacterial and viral ocular infections. An industrial hygiene ocular health questionnaire was distributed to a first and second shift manufacturing operation to assess the incidence of ocular infections. These data were compared to the questionnaire responses of 122 control manufacturing workers who did not use microscopes. Based on self-reporting by employees, those who used microscopes were found to have statistically significant incidence of sites and conjunctivitis that was 8.3 times that of the control group. Sterilization of eyepieces by ethylene oxide, formaldehyde and isopropyl alcohol were considered, but ultimately rejected. These biocides were found respectively to damage ocular lens coatings, contribute to volatile organic emissions, or be ineffective against spore-forming bacteria. This article presents a detailed evaluation of a commercially available ultraviolet sanitization unit (manufactured by the King Bactostat Corp., 7115 Armistad Street, El Paso, TX 79912). This ultraviolet disinfection process proved to be rapid and emission free; it also yielded eyepieces free of residual chemical biocides that have the potential for ocular irritation. Field tests involving 60 eyepieces demonstrated effective disinfection by a Chi-Square statistical comparison, at values greater than 95% confidence level, as compared to unirradiated eyepieces.

  2. Division of focal plane polarimeter-based 3 × 4 Mueller matrix microscope: a potential tool for quick diagnosis of human carcinoma tissues

    NASA Astrophysics Data System (ADS)

    Chang, Jintao; He, Honghui; Wang, Ye; Huang, Yi; Li, Xianpeng; He, Chao; Liao, Ran; Zeng, Nan; Liu, Shaoxiong; Ma, Hui

    2016-05-01

    A polarization microscope is a useful tool to reveal the optical anisotropic nature of a specimen and can provide abundant microstructural information about samples. We present a division of focal plane (DoFP) polarimeter-based polarization microscope capable of simultaneously measuring both the Stokes vector and the 3×4 Mueller matrix with an optimal polarization illumination scheme. The Mueller matrix images of unstained human carcinoma tissue slices show that the m24 and m34 elements can provide important information for pathological observations. The characteristic features of the m24 and m34 elements can be enhanced by polarization staining under illumination by a circularly polarized light. Hence, combined with a graphics processing unit acceleration algorithm, the DoFP polarization microscope is capable of real-time polarization imaging for potential quick clinical diagnoses of both standard and frozen slices of human carcinoma tissues.

  3. Mid-infrared frequency comb based on a quantum cascade laser.

    PubMed

    Hugi, Andreas; Villares, Gustavo; Blaser, Stéphane; Liu, H C; Faist, Jérôme

    2012-12-13

    Optical frequency combs act as rulers in the frequency domain and have opened new avenues in many fields such as fundamental time metrology, spectroscopy and frequency synthesis. In particular, spectroscopy by means of optical frequency combs has surpassed the precision and speed of Fourier spectrometers. Such a spectroscopy technique is especially relevant for the mid-infrared range, where the fundamental rotational-vibrational bands of most light molecules are found. Most mid-infrared comb sources are based on down-conversion of near-infrared, mode-locked, ultrafast lasers using nonlinear crystals. Their use in frequency comb spectroscopy applications has resulted in an unequalled combination of spectral coverage, resolution and sensitivity. Another means of comb generation is pumping an ultrahigh-quality factor microresonator with a continuous-wave laser. However, these combs depend on a chain of optical components, which limits their use. Therefore, to widen the spectroscopic applications of such mid-infrared combs, a more direct and compact generation scheme, using electrical injection, is preferable. Here we present a compact, broadband, semiconductor frequency comb generator that operates in the mid-infrared. We demonstrate that the modes of a continuous-wave, free-running, broadband quantum cascade laser are phase-locked. Combining mode proliferation based on four-wave mixing with gain provided by the quantum cascade laser leads to a phase relation similar to that of a frequency-modulated laser. The comb centre carrier wavelength is 7 micrometres. We identify a narrow drive current range with intermode beat linewidths narrower than 10 hertz. We find comb bandwidths of 4.4 per cent with an intermode stability of less than or equal to 200 hertz. The intermode beat can be varied over a frequency range of 65 kilohertz by radio-frequency injection. The large gain bandwidth and independent control over the carrier frequency offset and the mode spacing

  4. Speciation and distribution of copper in a mining soil using multiple synchrotron-based bulk and microscopic techniques.

    PubMed

    Yang, Jianjun; Liu, Jin; Dynes, James J; Peak, Derek; Regier, Tom; Wang, Jian; Zhu, Shenhai; Shi, Jiyan; Tse, John S

    2014-02-01

    Molecular-level understanding of soil Cu speciation and distribution assists in management of Cu contamination in mining sites. In this study, one soil sample, collected from a mining site contaminated since 1950s, was characterized complementarily by multiple synchrotron-based bulk and spatially resolved techniques for the speciation and distribution of Cu as well as other related elements (Fe, Ca, Mn, K, Al, and Si). Bulk X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that soil Cu was predominantly associated with Fe oxides instead of soil organic matter. This agreed with the closest association of Cu to Fe by microscopic X-ray fluorescence (U-XRF) and scanning transmission X-ray microscopy (STXM) nanoanalysis, along with the non-occurrence of photoreduction of soil Cu(II) by quick Cu L3,2-edge XANES spectroscopy (Q-XANES) which often occurs when Cu organic complexes are present. Furthermore, bulk-EXAFS and STXM-coupled Fe L3,2-edge nano-XANES analysis revealed soil Cu adsorbed primarily to Fe(III) oxides by inner-sphere complexation. Additionally, Cu K-edge μ-XANES, L3,2-edge bulk-XANES, and successive Q-XANES results identified the presence of Cu2S rather than radiation-damage artifacts dominant in certain microsites of the mining soil. This study demonstrates the great benefits in use of multiple combined synchrotron-based techniques for comprehensive understanding of Cu speciation in heterogeneous soil matrix, which facilitates our prediction of Cu reactivity and environmental fate in the mining site.

  5. A Review of Automatic Methods Based on Image Processing Techniques for Tuberculosis Detection from Microscopic Sputum Smear Images.

    PubMed

    Panicker, Rani Oomman; Soman, Biju; Saini, Gagan; Rajan, Jeny

    2016-01-01

    Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs, but it can also affect other parts of the body. TB remains one of the leading causes of death in developing countries, and its recent resurgences in both developed and developing countries warrant global attention. The number of deaths due to TB is very high (as per the WHO report, 1.5 million died in 2013), although most are preventable if diagnosed early and treated. There are many tools for TB detection, but the most widely used one is sputum smear microscopy. It is done manually and is often time consuming; a laboratory technician is expected to spend at least 15 min per slide, limiting the number of slides that can be screened. Many countries, including India, have a dearth of properly trained technicians, and they often fail to detect TB cases due to the stress of a heavy workload. Automatic methods are generally considered as a solution to this problem. Attempts have been made to develop automatic approaches to identify TB bacteria from microscopic sputum smear images. In this paper, we provide a review of automatic methods based on image processing techniques published between 1998 and 2014. The review shows that the accuracy of algorithms for the automatic detection of TB increased significantly over the years and gladly acknowledges that commercial products based on published works also started appearing in the market. This review could be useful to researchers and practitioners working in the field of TB automation, providing a comprehensive and accessible overview of methods of this field of research. PMID:26573654

  6. Evolution of structure and infrared radiation properties for ferrite-based amorphous coating

    NASA Astrophysics Data System (ADS)

    Lu, Lei; Fan, Xi'an; Zhang, Jianyi; Hu, Xiaoming; Li, Guangqiang; Zhang, Zhan

    2014-10-01

    The ferrite-based amorphous coatings with high infrared radiation properties have been successfully prepared on the surface of carbon steel substrate by plasma spraying process. The phase, morphology, microstructure, thermal behavior and infrared emissivity were determined by X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and infrared spectroscopy. The prepared coating could keep amorphous structure when the ambient temperature was below 700 °C and it would crystallize gradually with further increasing the temperature. The amorphous structure is confirmed to be constructive for improving the emissivity of ferrite-based coatings, especially in the 3-8 μm band. The emissivity of the amorphous coating obtained by plasma spraying was over 0.8 in 3-8 μm band at 800 °C, which was higher than that of the coating with same composition prepared by conventional brushing method. The excellent thermal shock resistance of the coatings makes them to be good candidates for sensible energy-saving materials, which could work for long term at 1000 °C.

  7. [The correlation based mid-infrared temperature and emissivity separation algorithm].

    PubMed

    Cheng, Jie; Nie, Ai-Xiu; Du, Yong-Ming

    2009-02-01

    Temperature and emissivity separation is the key problem in infrared remote sensing. Based on the analysis of the relationship between the atmospheric downward radiance and surface emissivity containing atmosphere residue without the effects of sun irradiation, the present paper puts forward a temperature and emissivity separation algorithm for the ground-based mid-infrared hyperspectral data. The algorithm uses the correlation between the atmospheric downward radiance and surface emissivity containing atmosphere residue as a criterion to optimize the surface temperature, and the correlation between the atmospheric downward radiance and surface emissivity containing atmosphere residue depends on the bias between the estimated surface temperature and true surface temperature. The larger the temperature bias, the greater the correlation. Once we have obtained the surface temperature, the surface emissivity can be calculated easily. The accuracy of the algorithm was evaluated with the simulated mid-infrared hyperspectral data. The results of simulated calculation show that the algorithm can achieve higher accuracy of temperature and emissivity inversion, and also has broad applicability. Meanwhile, the algorithm is insensitive to the instrumental random noise and the change in atmospheric downward radiance during the field measurements.

  8. Continuous glucose determination using fiber-based tunable mid-infrared laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Yu, Songlin; Li, Dachao; Chong, Hao; Sun, Changyue; Xu, Kexin

    2014-04-01

    Wavelength-tunable laser spectroscopy in combination with a small-sized fiber-optic attenuated total reflection (ATR) sensor (fiber-based evanescent field analysis, FEFA) is reported for the continuous measurement of the glucose level. We propose a method of controlling and stabilizing the wavelength and power of laser emission and present a newly developed mid-infrared wavelength-tunable laser with a broad emission spectrum band of 9.19-9.77 μm (1024-1088 cm-1). The novel small-sized flow-through fiber-optic ATR sensor with long optical sensing length was used for glucose level determination. The experimental results indicate that the noise-equivalent concentration of this laser measurement system is as low as 3.8 mg/dL, which is among the most precise glucose measurements using mid-infrared spectroscopy. The sensitivity, which is three times that of conventional Fourier transform infrared spectrometer, was acquired because of the higher laser power and higher spectral resolution. The best prediction of the glucose concentration in phosphate buffered saline solution was achieved using the five-variable partial least-squares model, yielding a root-mean-square error of prediction as small as 3.5 mg/dL. The high sensitivity, multiple tunable wavelengths and small fiber-based sensor with long optical sensing length make glucose determination possible in blood or interstitial fluid in vivo.

  9. A color fusion method of infrared and low-light-level images based on visual perception

    NASA Astrophysics Data System (ADS)

    Han, Jing; Yan, Minmin; Zhang, Yi; Bai, Lianfa

    2014-11-01

    The color fusion images can be obtained through the fusion of infrared and low-light-level images, which will contain both the information of the two. The fusion images can help observers to understand the multichannel images comprehensively. However, simple fusion may lose the target information due to inconspicuous targets in long-distance infrared and low-light-level images; and if targets extraction is adopted blindly, the perception of the scene information will be affected seriously. To solve this problem, a new fusion method based on visual perception is proposed in this paper. The extraction of the visual targets ("what" information) and parallel processing mechanism are applied in traditional color fusion methods. The infrared and low-light-level color fusion images are achieved based on efficient typical targets learning. Experimental results show the effectiveness of the proposed method. The fusion images achieved by our algorithm can not only improve the detection rate of targets, but also get rich natural information of the scenes.

  10. Autonomous docking based on infrared system for electric vehicle charging in urban areas.

    PubMed

    Pérez, Joshué; Nashashibi, Fawzi; Lefaudeux, Benjamin; Resende, Paulo; Pollard, Evangeline

    2013-02-21

    Electric vehicles are progressively introduced in urban areas, because of their ability to reduce air pollution, fuel consumption and noise nuisance. Nowadays, some big cities are launching the first electric car-sharing projects to clear traffic jams and enhance urban mobility, as an alternative to the classic public transportation systems. However, there are still some problems to be solved related to energy storage, electric charging and autonomy. In this paper, we present an autonomous docking system for electric vehicles recharging based on an embarked infrared camera performing infrared beacons detection installed in the infrastructure. A visual servoing system coupled with an automatic controller allows the vehicle to dock accurately to the recharging booth in a street parking area. The results show good behavior of the implemented system, which is currently deployed as a real prototype system in the city of Paris.

  11. Near-Infrared Phosphorescent Iridium(III) Benzonorrole Complexes Possessing Pyridine-based Axial Ligands.

    PubMed

    Maurya, Yogesh Kumar; Ishikawa, Takahiro; Kawabe, Yasunori; Ishida, Masatoshi; Toganoh, Motoki; Mori, Shigeki; Yasutake, Yuhsuke; Fukatsu, Susumu; Furuta, Hiroyuki

    2016-06-20

    Novel near-infrared phosphorescent iridium(III) complexes based on benzo-annulated N-linked corrole analogue (termed as benzonorrole) were synthesized. The structures of the complexes revealed octahedral coordination geometries involving an organometallic iridium-carbon bond with two external axial ligands. Interestingly, the iridium(III) complex exhibits near-infrared phosphorescence at room temperature at wavelengths beyond 900 nm. The significant redshift of the emission, as compared to the corrole congener, is originated from the ligand-centered triplet character. The fine-tuning of the photophysical properties of the complexes was achieved by introducing electron-donating and electron-withdrawing substituents on the axial pyridine ligands. PMID:27249778

  12. Autonomous Docking Based on Infrared System for Electric Vehicle Charging in Urban Areas

    PubMed Central

    Pérez, Joshué; Nashashibi, Fawzi; Lefaudeux, Benjamin; Resende, Paulo; Pollard, Evangeline

    2013-01-01

    Electric vehicles are progressively introduced in urban areas, because of their ability to reduce air pollution, fuel consumption and noise nuisance. Nowadays, some big cities are launching the first electric car-sharing projects to clear traffic jams and enhance urban mobility, as an alternative to the classic public transportation systems. However, there are still some problems to be solved related to energy storage, electric charging and autonomy. In this paper, we present an autonomous docking system for electric vehicles recharging based on an embarked infrared camera performing infrared beacons detection installed in the infrastructure. A visual servoing system coupled with an automatic controller allows the vehicle to dock accurately to the recharging booth in a street parking area. The results show good behavior of the implemented system, which is currently deployed as a real prototype system in the city of Paris. PMID:23429581

  13. Quantitative detection of defects based on Markov-PCA-BP algorithm using pulsed infrared thermography technology

    NASA Astrophysics Data System (ADS)

    Tang, Qingju; Dai, Jingmin; Liu, Junyan; Liu, Chunsheng; Liu, Yuanlin; Ren, Chunping

    2016-07-01

    Quantitative detection of debonding defects' diameter and depth in TBCs has been carried out using pulsed infrared thermography technology. By combining principal component analysis with neural network theory, the Markov-PCA-BP algorithm was proposed. The principle and realization process of the proposed algorithm was described. In the prediction model, the principal components which can reflect most characteristics of the thermal wave signal were set as the input, and the defect depth and diameter was set as the output. The experimental data from pulsed infrared thermography tests of TBCs with flat bottom hole defects was selected as the training and testing sample. Markov-PCA-BP predictive system was arrived, based on which both the defect depth and diameter were identified accurately, which proved the effectiveness of the proposed method for quantitative detection of debonding defects in TBCs.

  14. A Differential Interference Contrast-Based Light Microscopic System for Laser Microsurgery and Optical Trapping of Selected Chromosomes during Mitosis In Vivo

    NASA Astrophysics Data System (ADS)

    Cole, Richard W.; Khodjakov, Alexey; Wright, William H.; Rieder, Conly L.

    1995-10-01

    Laser microsurgery and laser-generated optical force traps (optical tweezers) are both valuable light microscopic-based approaches for studying intra- and extracellular motility processes, including chromosome segregation during mitosis. Here we describe a system in use in our laboratory that allows living cells to be followed by high-resolution differential interference contrast (DIC) video-enhanced time-lapse light microscopy while selected mitotic organelles and spindle components are subjected to laser microsurgery and/or manipulation with an optical force trap. This system couples the output from two different Neodymium-YAG lasers to the same inverted light microscope equipped with both phase-contrast and de Senarmont compensation DIC optics, a motorized stage, and a high-resolution low-light-level CCD camera. Unlike similar systems using phase-contrast optics, our DIC-based system can image living cells in thin optical sections without contamination due to phase halos or out-of-focus object information. These advantages greatly facilitate laser-based light microscopic studies on mitotic organelles and components, including spindle poles (centrosomes) and kinetochores, which are at or below the resolution limit of the light microscope and buried within a large complex structure. When used in conjunction with image processing and high-resolution object-tracking techniques, our system provides new information on the roles that kinetochores and spindle microtubules play during chromosome segregation in plant and animal cells.

  15. Non-local means-based nonuniformity correction for infrared focal-plane array detectors

    NASA Astrophysics Data System (ADS)

    Yu, Hui; Zhang, Zhi-jie; Chen, Fu-sheng; Wang, Chen-sheng

    2014-11-01

    The infrared imaging systems are normally based on the infrared focal-plane array (IRFPA) which can be considered as an array of independent detectors aligned at the focal plane of the imaging system. Unfortunately, every detector on the IRFPA may have a different response to the same input infrared signal which is known as the nonuniformity problem. Then we can observe the fixed pattern noise (FPN) from the resulting images. Standard nonuniformity correction (NUC) methods need to be recalibrated after a short period of time due the temporal drift of the FPN. Scene-based nonuniformity correction (NUC) techniques eliminate the need for calibration by correction coefficients based on the scene being viewed. However, in the scene-based NUC method the problem of ghosting artifacts widely seriously decreases the image quality, which can degrade the performance of many applications such as target detection and track. This paper proposed an improved scene-based method based on the retina-like neural network approach. The method incorporates the use of non-local means (NLM) method into the estimation of the gain and the offset of each detector. This method can not only estimates the accurate correction coefficient but also restrict the ghosting artifacts efficiently. The proposed method relies on the use of NLM method which is a very successful image denoising method. And then the NLM used here can preserve the image edges efficiently and obtain a reliable spatial estimation. We tested the proposed NUC method by applying it to an IR sequence of frames. The performance of the proposed method was compared the other well-established adaptive NUC techniques.

  16. Trends in Correlation-Based Pattern Recognition and Tracking in Forward-Looking Infrared Imagery

    PubMed Central

    Alam, Mohammad S.; Bhuiyan, Sharif M. A.

    2014-01-01

    In this paper, we review the recent trends and advancements on correlation-based pattern recognition and tracking in forward-looking infrared (FLIR) imagery. In particular, we discuss matched filter-based correlation techniques for target detection and tracking which are widely used for various real time applications. We analyze and present test results involving recently reported matched filters such as the maximum average correlation height (MACH) filter and its variants, and distance classifier correlation filter (DCCF) and its variants. Test results are presented for both single/multiple target detection and tracking using various real-life FLIR image sequences. PMID:25061840

  17. Infrared laser-based monitoring of the silane dissociation during deposition of silicon thin films

    SciTech Connect

    Bartlome, R.; Feltrin, A.; Ballif, C.

    2009-05-18

    The silane dissociation efficiency, or depletion fraction, is an important plasma parameter by means of which the film growth rate and the amorphous-to-microcrystalline silicon transition regime can be monitored in situ. In this letter we implement a homebuilt quantum cascade laser-based absorption spectrometer to measure the silane dissociation efficiency in an industrial plasma-enhanced chemical vapor deposition system. This infrared laser-based diagnostic technique is compact, sensitive, and nonintrusive. Its resolution is good enough to resolve Doppler-broadened rotovibrational absorption lines of silane. The latter feature various absorption strengths, thereby enabling depletion measurements over a wide range of process conditions.

  18. Space-based infrared scanning sensor LOS determination and calibration using star observation

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Xu, Zhan; An, Wei; Deng, Xin-Pu; Yang, Jun-Gang

    2015-10-01

    This paper provides a novel methodology for removing sensor bias from a space based infrared (IR) system (SBIRS) through the use of stars detected in the background field of the sensor. Space based IR system uses the LOS (line of sight) of target for target location. LOS determination and calibration is the key precondition of accurate location and tracking of targets in Space based IR system and the LOS calibration of scanning sensor is one of the difficulties. The subsequent changes of sensor bias are not been taking into account in the conventional LOS determination and calibration process. Based on the analysis of the imaging process of scanning sensor, a theoretical model based on the estimation of bias angles using star observation is proposed. By establishing the process model of the bias angles and the observation model of stars, using an extended Kalman filter (EKF) to estimate the bias angles, and then calibrating the sensor LOS. Time domain simulations results indicate that the proposed method has a high precision and smooth performance for sensor LOS determination and calibration. The timeliness and precision of target tracking process in the space based infrared (IR) tracking system could be met with the proposed algorithm.

  19. Oral cancer diagnostics based on infrared spectral markers and wax physisorption kinetics.

    PubMed

    Chiu, Li-Fang; Huang, Pei-Yu; Chiang, Wei-Fan; Wong, Tung-Yiu; Lin, Sheng-Hsiang; Lee, Yao-Chang; Shieh, Dar-Bin

    2013-02-01

    Infrared microspectroscopy is an emerging approach for disease analysis owing to its capability for in situ chemical characterization of pathological processes. Synchrotron-based infrared microspectroscopy (SR-IMS) provides ultra-high spatial resolution for profiling biochemical events associated with disease progression. Spectral alterations were observed in cultured oral cells derived from healthy, precancerous, primary, and metastatic cancers. An innovative wax-physisorption-based kinetic FTIR imaging method for the detection of oral precancer and cancer was demonstrated successfully. The approach is based on determining the residual amount of paraffin wax (C(25)H(52)) or beeswax (C(46)H(92)O(2)) on a sample surface after xylene washing. This amount is used as a signpost of the degree of physisorption that altered during malignant transformation. The results of linear discriminant analysis (LDA) of oral cell lines indicated that the methylene (CH(2)) and methyl group (CH(3)) stretching vibrations in the range of 3,000-2,800 cm(-1) have the highest accuracy rate (89.6 %) to discriminate the healthy keratinocytes (NHOK) from cancer cells. The results of wax-physisorption-based FTIR imaging showed a stronger physisorption with beeswax in oral precancerous and cancer cells as compared with that of NHOK, which showed a strong capability with paraffin wax. The infrared kinetic study of oral cavity tissue showed a consistency in the wax physisorption of the cell lines. On the basis of our findings, these results show the potential use of wax-physisorption-based kinetic FTIR imaging for the early screening of oral cancer lesions and the chemical changes during oral carcinogenesis.

  20. Monitoring enzyme-catalyzed reactions in micromachined nanoliter wells using a conventional microscope-based microarray reader

    NASA Astrophysics Data System (ADS)

    van den Doel, L. Richard; Moerman, R.; van Dedem, G. W. K.; Young, Ian T.; van Vliet, Lucas J.

    2002-06-01

    Yeast-Saccharomyces cerevisiae - it widely used as a model system for other higher eukaryotes, including man. One of the basic fermentation processes in yeast is the glycolytic pathway, which is the conversion of glucose to ethanol and carbon dioxide. This pathway consists of 12 enzyme-catalyzed reactions. With the approach of microarray technology we want to explore the metabolic regulation of this pathway in yeast. This paper will focus on the design of a conventional microscope based microarray reader, which is used to monitor these enzymatic reactions in microarrays. These microarrays are fabricated in silicon and have sizes of 300 by 300 micrometers 2. The depth varies from 20 to 50 micrometers . Enzyme activity levels can be derived by monitoring the production or consumption rate of NAD(P)H, which is excited at 360nm and emits around 450nm. This fluorophore is involved in all 12 reactions of the pathway. The microarray reader is equipped with a back-illuminated CCD camera in order to obtain a high quantum efficiency for the lower wavelengths. The dynamic range of our microarray reader varies form 5(mu) Molar to 1mMolar NAD(P)H. With this microarray reader enzyme activity levels down to 0.01 unit per milliliter can be monitored. The acquisition time per well is 0.1s. The total scan cycle time for a 5 X 5 microarray is less than half a minute. The number of cycles for a proper estimation of the enzyme activity is inversely proportional to the enzyme activity: long measurement times are needed to determine low enzyme activity levels.

  1. [Study on Trace Water Influence on Electrical Properties of Insulating Oil Based on the Mid-Infrared Spectrum Analysis].

    PubMed

    Chen, Bin; Wu, Hong-yang; Han, Chao; Yan, Huan; Liu, Ge

    2015-10-01

    Trace water has a significant impact on the electrical performances of the insulating oil, such as the dielectric loss factor, resistivity. So there is an important significance to investigate the influence of insulating oil by trace water, and monitor its operating status with effective measures. First, it is necessary to prepare the insulating oil samples with different water content and treat them 8 hours with ultrasonic oscillator, and observe microscopic images about the water-oil mixtures in order to study their relative uniformity and stable time, in the way it can be concluded that the relative uniformity can be kept favorable during the 25 min stable time for free water and emulsification water in oil; Based on this conclusion, the dielectric loss factor, resistivity were tested and the electrical performances of insulating oil with different water content in oil can obtained by analyzing these data; Then, the absorbance value of the different water content in oil at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm(-1), with the mid-infrared spectral scanning and analyzing to the different water content in oil, Therefore, combined the water absorbance values by the mid-infrared spectral scanning and analyzing with the experimental data of dielectric loss factor value, resistivity value of oil samples. The results shows that the absorbance value of the different water content in oil has a significant difference at the spectral wave number of 1 640, 3 400, 3450, 3 615 cm(-1), their correlation coefficient are 0.964 1, 0.984 8, 0.984 5, 0.944 0 between the absorbance value and water content at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm(-1), it can be obtained that the absorbance value of sample of moisture in the corresponding characteristic wave number can better reflect the change trend of water content; there is the highly relative of water absorbance values at the spectral wave number of 3 400 and 3 450 cm(-1) with the trends of

  2. Clinical Trial on the Characteristics of Zheng Classification of Pulmonary Diseases Based on Infrared Thermal Imaging Technology

    PubMed Central

    Ni, Jin-xia; Gao, Si-hua; Li, Yu-hang; Ma, Shi-lei; Tian, Tian; Mo, Fang-fang; Wang, Liu-qing; Zhu, Wen-zeng

    2013-01-01

    Zheng classification study based on infrared thermal imaging technology has not been reported before. To detect the relative temperature of viscera and bowels of different syndromes patients with pulmonary disease and to summarize the characteristics of different Zheng classifications, the infrared thermal imaging technology was used in the clinical trial. The results showed that the infrared thermal images characteristics of different Zheng classifications of pulmonary disease were distinctly different. The influence on viscera and bowels was deeper in phlegm-heat obstructing lung syndrome group than in cold-phlegm obstructing lung syndrome group. It is helpful to diagnose Zheng classification and to improve the diagnosis rate by analyzing the infrared thermal images of patients. The application of infrared thermal imaging technology provided objective measures for medical diagnosis and treatment in the field of Zheng studies and provided a new methodology for Zheng classification. PMID:23606873

  3. Clinical trial on the characteristics of zheng classification of pulmonary diseases based on infrared thermal imaging technology.

    PubMed

    Ni, Jin-Xia; Gao, Si-Hua; Li, Yu-Hang; Ma, Shi-Lei; Tian, Tian; Mo, Fang-Fang; Wang, Liu-Qing; Zhu, Wen-Zeng

    2013-01-01

    Zheng classification study based on infrared thermal imaging technology has not been reported before. To detect the relative temperature of viscera and bowels of different syndromes patients with pulmonary disease and to summarize the characteristics of different Zheng classifications, the infrared thermal imaging technology was used in the clinical trial. The results showed that the infrared thermal images characteristics of different Zheng classifications of pulmonary disease were distinctly different. The influence on viscera and bowels was deeper in phlegm-heat obstructing lung syndrome group than in cold-phlegm obstructing lung syndrome group. It is helpful to diagnose Zheng classification and to improve the diagnosis rate by analyzing the infrared thermal images of patients. The application of infrared thermal imaging technology provided objective measures for medical diagnosis and treatment in the field of Zheng studies and provided a new methodology for Zheng classification.

  4. Leaf Chlorophyll Content Estimation of Winter Wheat Based on Visible and Near-Infrared Sensors.

    PubMed

    Zhang, Jianfeng; Han, Wenting; Huang, Lvwen; Zhang, Zhiyong; Ma, Yimian; Hu, Yamin

    2016-03-25

    The leaf chlorophyll content is one of the most important factors for the growth of winter wheat. Visual and near-infrared sensors are a quick and non-destructive testing technology for the estimation of crop leaf chlorophyll content. In this paper, a new approach is developed for leaf chlorophyll content estimation of winter wheat based on visible and near-infrared sensors. First, the sliding window smoothing (SWS) was integrated with the multiplicative scatter correction (MSC) or the standard normal variable transformation (SNV) to preprocess the reflectance spectra images of wheat leaves. Then, a model for the relationship between the leaf relative chlorophyll content and the reflectance spectra was developed using the partial least squares (PLS) and the back propagation neural network. A total of 300 samples from areas surrounding Yangling, China, were used for the experimental studies. The samples of visible and near-infrared spectroscopy at the wavelength of 450,900 nm were preprocessed using SWS, MSC and SNV. The experimental results indicate that the preprocessing using SWS and SNV and then modeling using PLS can achieve the most accurate estimation, with the correlation coefficient at 0.8492 and the root mean square error at 1.7216. Thus, the proposed approach can be widely used for winter wheat chlorophyll content analysis.

  5. A novel objective sour taste evaluation method based on near-infrared spectroscopy.

    PubMed

    Hoshi, Ayaka; Aoki, Soichiro; Kouno, Emi; Ogasawara, Masashi; Onaka, Takashi; Miura, Yutaka; Mamiya, Kanji

    2014-05-01

    One of the most important themes in the development of foods and drinks is the accurate evaluation of taste properties. In general, a sensory evaluation system is frequently used for evaluating food and drink. This method, which is dependent on human senses, is highly sensitive but is influenced by the eating experience and food palatability of individuals, leading to subjective results. Therefore, a more effective method for objectively estimating taste properties is required. Here we show that salivary hemodynamic signals, as measured by near-infrared spectroscopy, are a useful objective indicator for evaluating sour taste stimulus. In addition, the hemodynamic responses of the parotid gland are closely correlated to the salivary secretion volume of the parotid gland in response to basic taste stimuli and respond to stimuli independently of the hedonic aspect. Moreover, we examined the hemodynamic responses to complex taste stimuli in food-based solutions and demonstrated for the first time that the complicated phenomenon of the "masking effect," which decreases taste intensity despite the additional taste components, can be successfully detected by near-infrared spectroscopy. In summary, this study is the first to demonstrate near-infrared spectroscopy as a novel tool for objectively evaluating complex sour taste properties in foods and drinks.

  6. Determination of melamine of milk based on two-dimensional correlation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yang, Ren-jie; Liu, Rong; Xu, Kexin

    2012-03-01

    The adulteration of milk with harmful substances is a threat to public health and beyond question a serious crime. In order to develop a rapid, cost-effective, high-throughput analysis method for detecting of adulterants in milk, the discriminative analysis of melamine is established in milk based on the two-dimensional (2D) correlation infrared spectroscopy in present paper. Pure milk samples and adulterated milk samples with different content of melamine were prepared. Then the Fourier Transform Infrared spectra of all samples were measured at room temperature. The characteristics of pure milk and adulterated milk were studied by one-dimensional spectra. The 2D NIR and 2D IR correlation spectroscopy were calculated under the perturbation of adulteration concentration. In the range from 1400 to 1800 cm-1, two strong autopeaks were aroused by melamine in milk at 1464 cm-1 and 1560 cm-1 in synchronous spectrum. At the same time, the 1560 cm-1 band does not share cross peak with the 1464 cm-1 band, which further confirm that the two bands have the same origin. Also in the range from 4200 to 4800 cm-1, the autopeak was shown at 4648 cm-1 in synchronous spectrum of melamine in milk. 2D NIR-IR hetero-spectral correlation analysis confirmed that the bands at 1464, 1560 and 4648 cm-1 had the same origin. The results demonstrated that the adulterant can be discriminated correctly by 2D correlation infrared spectroscopy.

  7. Captive flight test-based infrared validation of a hardware-in-the-loop simulation

    NASA Astrophysics Data System (ADS)

    Sanders, Jeffrey S.; Roland, Randall; Cosby, David S.; Saylor, Daniel A.; Harrison, Kenneth R.

    2000-07-01

    This paper describes infrared (IR) scene generation and validation activities at the U.S. Army Aviation and Missile Command's (AMCOM) Dual-Mode Hardware-in-the-Loop (HWIL) Simulation. The HWIL simulation validation results are based on comparison of infrared seeker data collected in the HWIL simulation to infrared seeker data collected during captive flight tests (CFTs). Use of CFT data allows a simulation developer to quantify not only the radiometric fidelity of the simulation inputs, but also the effects that any limitations of the inputs may have on simulation validity with respect to a particular seeker and its algorithms. Validation of this type of simulation is a complex process and all aspects of the validation are covered. Topics include real-time IR signature modeling and validation, simulation output verification, projected energy verification, and total end-to-end simulation validation. Also included are descriptions of the different types of CFT scenarios necessary for simulation validation and the comparison methodologies used for each case.

  8. Thermal physical property-based fusion of geostationary meteorological satellite visible and infrared channel images.

    PubMed

    Han, Lei; Shi, Lu; Yang, Yiling; Song, Dalei

    2014-06-10

    Geostationary meteorological satellite infrared (IR) channel data contain important spectral information for meteorological research and applications, but their spatial resolution is relatively low. The objective of this study is to obtain higher-resolution IR images. One common method of increasing resolution fuses the IR data with high-resolution visible (VIS) channel data. However, most existing image fusion methods focus only on visual performance, and often fail to take into account the thermal physical properties of the IR images. As a result, spectral distortion occurs frequently. To tackle this problem, we propose a thermal physical properties-based correction method for fusing geostationary meteorological satellite IR and VIS images. In our two-step process, the high-resolution structural features of the VIS image are first extracted and incorporated into the IR image using regular multi-resolution fusion approach, such as the multiwavelet analysis. This step significantly increases the visual details in the IR image, but fake thermal information may be included. Next, the Stefan-Boltzmann Law is applied to correct the distortion, to retain or recover the thermal infrared nature of the fused image. The results of both the qualitative and quantitative evaluation demonstrate that the proposed physical correction method both improves the spatial resolution and preserves the infrared thermal properties.

  9. [Detection of reducing sugar content of potato granules based on wavelet compression by near infrared spectroscopy].

    PubMed

    Dong, Xiao-Ling; Sun, Xu-Dong

    2013-12-01

    The feasibility was explored in determination of reducing sugar content of potato granules based on wavelet compression algorithm combined with near-infrared spectroscopy. The spectra of 250 potato granules samples were recorded by Fourier transform near-infrared spectrometer in the range of 4000- 10000 cm-1. The three parameters of vanishing moments, wavelet coefficients and principal component factor were optimized. The optimization results of three parameters were 10, 100 and 20, respectively. The original spectra of 1501 spectral variables were transfered to 100 wavelet coefficients using db wavelet function. The partial least squares (PLS) calibration models were developed by 1501 spectral variables and 100 wavelet coefficients. Sixty two unknown samples of prediction set were applied to evaluate the performance of PLS models. By comparison, the optimal result was obtained by wavelet compression combined with PLS calibration model. The correlation coefficient of prediction and root mean square error of prediction were 0.98 and 0.181%, respectively. Experimental results show that the dimensions of spectral data were reduced, scarcely losing effective information by wavelet compression algorithm combined with near-infrared spectroscopy technology in determination of reducing sugar in potato granules. The PLS model is simplified, and the predictive ability is improved. PMID:24611373

  10. Visible and infrared tracking based on multi-view multi-kernel fusion model

    NASA Astrophysics Data System (ADS)

    Yun, Xiao; Jing, Zhongliang; Jin, Bo

    2016-04-01

    In the visual tracking problem, fusion of visible and infrared sensors provides complementarily useful features and can consistently help distinguish the target from the background efficiently. Recently, multi-view learning has received growing attention due to its enormous potential in combining diverse view features containing consistent and complementary characteristics. Therefore, in this paper, a visible and infrared fusion tracking algorithm based on multi-view multi-kernel fusion (MVMKF) model is presented. The proposed MVMKF model considers the diversities of visible and infrared views and embeds complementary information from them. Furthermore, the multi-kernel framework is used to learn the importance of view features so that an integrated appearance representation is made with regard to the respective performance. Besides, the tracking task is completed with naive Bayes classifier in sophisticated compressive feature domain, considering the high performances of classifier-level and sophisticated feature-level learning for multiple views. The experimental results demonstrate that the MVMKF tracking algorithm performs well in terms of accuracy and robustness.

  11. Precise Temperature Mapping of GaN-Based LEDs by Quantitative Infrared Micro-Thermography

    PubMed Central

    Chang, Ki Soo; Yang, Sun Choel; Kim, Jae-Young; Kook, Myung Ho; Ryu, Seon Young; Choi, Hae Young; Kim, Geon Hee

    2012-01-01

    A method of measuring the precise temperature distribution of GaN-based light-emitting diodes (LEDs) by quantitative infrared micro-thermography is reported. To reduce the calibration error, the same measuring conditions were used for both calibration and thermal imaging; calibration was conducted on a highly emissive black-painted area on a dummy sapphire wafer loaded near the LED wafer on a thermoelectric cooler mount. We used infrared thermal radiation images of the black-painted area on the dummy wafer and an unbiased LED wafer at two different temperatures to determine the factors that degrade the accuracy of temperature measurement, i.e., the non-uniform response of the instrument, superimposed offset radiation, reflected radiation, and emissivity map of the LED surface. By correcting these factors from the measured infrared thermal radiation images of biased LEDs, we determined a precise absolute temperature image. Consequently, we could observe from where the local self-heat emerges and how it distributes on the emitting area of the LEDs. The experimental results demonstrated that highly localized self-heating and a remarkable temperature gradient, which are detrimental to LED performance and reliability, arise near the p-contact edge of the LED surface at high injection levels owing to the current crowding effect. PMID:22666050

  12. Fabrication of metasurface-based infrared absorber structures using direct laser write lithography

    NASA Astrophysics Data System (ADS)

    Fanyaeu, Ihar; Mizeikis, Vygantas

    2016-03-01

    We report fabrication and optical properties of ultra-thin polarization-invariant electromagnetic absorber metasurface for infra-red spectral. The absorber structure, which uses three-dimensional architecture is based on single-turn metallic helices arranged into a periodic square lattice on a metallic substrate, is expected to exhibit total resonant absorption due to balanced coupling between resonances of the helices. The structure was designed using numerical simulations aiming to tune the total absorption resonance to infra-red wavelength range by appropriately downscaling the unit cell of the structure, and taking into account dielectric dispersion and losses of the metal. The designed structures were subsequently fabricated using femtosecond direct laser write technique in a dielectric photoresist, and subsequent metallisation by gold sputtering. In accordance with the expectations, the structure was found to exhibit resonant absorption centred near the wavelength of 6 - 9 µm, with peak absorption in excess of 82%. The absorber metasurface may be applied in various areas of science and technology, such as harvesting infra-red radiation in thermal detectors and energy converters.

  13. A novel infrared small moving target detection method based on tracking interest points under complicated background

    NASA Astrophysics Data System (ADS)

    Dong, Xiabin; Huang, Xinsheng; Zheng, Yongbin; Bai, Shengjian; Xu, Wanying

    2014-07-01

    Infrared moving target detection is an important part of infrared technology. We introduce a novel infrared small moving target detection method based on tracking interest points under complicated background. Firstly, Difference of Gaussians (DOG) filters are used to detect a group of interest points (including the moving targets). Secondly, a sort of small targets tracking method inspired by Human Visual System (HVS) is used to track these interest points for several frames, and then the correlations between interest points in the first frame and the last frame are obtained. Last, a new clustering method named as R-means is proposed to divide these interest points into two groups according to the correlations, one is target points and another is background points. In experimental results, the target-to-clutter ratio (TCR) and the receiver operating characteristics (ROC) curves are computed experimentally to compare the performances of the proposed method and other five sophisticated methods. From the results, the proposed method shows a better discrimination of targets and clutters and has a lower false alarm rate than the existing moving target detection methods.

  14. Leaf Chlorophyll Content Estimation of Winter Wheat Based on Visible and Near-Infrared Sensors

    PubMed Central

    Zhang, Jianfeng; Han, Wenting; Huang, Lvwen; Zhang, Zhiyong; Ma, Yimian; Hu, Yamin

    2016-01-01

    The leaf chlorophyll content is one of the most important factors for the growth of winter wheat. Visual and near-infrared sensors are a quick and non-destructive testing technology for the estimation of crop leaf chlorophyll content. In this paper, a new approach is developed for leaf chlorophyll content estimation of winter wheat based on visible and near-infrared sensors. First, the sliding window smoothing (SWS) was integrated with the multiplicative scatter correction (MSC) or the standard normal variable transformation (SNV) to preprocess the reflectance spectra images of wheat leaves. Then, a model for the relationship between the leaf relative chlorophyll content and the reflectance spectra was developed using the partial least squares (PLS) and the back propagation neural network. A total of 300 samples from areas surrounding Yangling, China, were used for the experimental studies. The samples of visible and near-infrared spectroscopy at the wavelength of 450,900 nm were preprocessed using SWS, MSC and SNV. The experimental results indicate that the preprocessing using SWS and SNV and then modeling using PLS can achieve the most accurate estimation, with the correlation coefficient at 0.8492 and the root mean square error at 1.7216. Thus, the proposed approach can be widely used for winter wheat chlorophyll content analysis. PMID:27023550

  15. Novel infrared image enhancement technology based on the frequency compensation approach

    NASA Astrophysics Data System (ADS)

    Qi, Yuhua; He, Rulong; Lin, Haitao

    2016-05-01

    A novel infrared image enhancement method has been proposed in this paper. Our aim is to develop a detail enhancement method which is focused on the frequency feature of the image. The proposed method is following the most popular strategy of enhancing the infrared images nowadays, but concentrating on the frequency domain. Firstly, the original image is separated by a guided image filter into detail layer and the base layer. Quite unlike the traditional methods, we use the guided image filter to eliminate most of the noise and weak signal of the scenario. Then, by a designed iteration process, the higher frequency of the scenario will be calculated back and add to the detail layer. The noise will not be enhanced because the iteration is only focused on the leftover scenario frequency. We run many tests on the raw data captured by the 320 × 256 HgCdTe cooled thermal imager, and make a comparison between our approach with the previous method of bilateral filtering digital detail enhancement and guided image filtering digital detail enhancement. Figures and analytical data show that our method is better than the previous proposed researches. Our method could effectively process the infrared image with less noise and artifacts, which has potential applications in testing, manufacturing, chemical imaging, night vision, and surveillance security.

  16. Precise temperature mapping of GaN-based LEDs by quantitative infrared micro-thermography.

    PubMed

    Chang, Ki Soo; Yang, Sun Choel; Kim, Jae-Young; Kook, Myung Ho; Ryu, Seon Young; Choi, Hae Young; Kim, Geon Hee

    2012-01-01

    A method of measuring the precise temperature distribution of GaN-based light-emitting diodes (LEDs) by quantitative infrared micro-thermography is reported. To reduce the calibration error, the same measuring conditions were used for both calibration and thermal imaging; calibration was conducted on a highly emissive black-painted area on a dummy sapphire wafer loaded near the LED wafer on a thermoelectric cooler mount. We used infrared thermal radiation images of the black-painted area on the dummy wafer and an unbiased LED wafer at two different temperatures to determine the factors that degrade the accuracy of temperature measurement, i.e., the non-uniform response of the instrument, superimposed offset radiation, reflected radiation, and emissivity map of the LED surface. By correcting these factors from the measured infrared thermal radiation images of biased LEDs, we determined a precise absolute temperature image. Consequently, we could observe from where the local self-heat emerges and how it distributes on the emitting area of the LEDs. The experimental results demonstrated that highly localized self-heating and a remarkable temperature gradient, which are detrimental to LED performance and reliability, arise near the p-contact edge of the LED surface at high injection levels owing to the current crowding effect.

  17. Robust method for infrared small-target detection based on Boolean map visual theory.

    PubMed

    Qi, Shengxiang; Ming, Delie; Ma, Jie; Sun, Xiao; Tian, Jinwen

    2014-06-20

    In this paper, we present an infrared small target detection method based on Boolean map visual theory. The scheme is inspired by the phenomenon that small targets can often attract human attention due to two characteristics: brightness and Gaussian-like shape in the local context area. Motivated by this observation, we perform the task under a visual attention framework with Boolean map theory, which reveals that an observer's visual awareness corresponds to one Boolean map via a selected feature at any given instant. Formally, the infrared image is separated into two feature channels, including a color channel with the original gray intensity map and an orientation channel with the orientation texture maps produced by a designed second order directional derivative filter. For each feature map, Boolean maps delineating targets are computed from hierarchical segmentations. Small targets are then extracted from the target enhanced map, which is obtained by fusing the weighted Boolean maps of the two channels. In experiments, a set of real infrared images covering typical backgrounds with sky, sea, and ground clutters are tested to verify the effectiveness of our method. The results demonstrate that it outperforms the state-of-the-art methods with good performance.

  18. Particle filter-based relative rolling estimation algorithm for non-cooperative infrared spacecraft

    NASA Astrophysics Data System (ADS)

    Li, Zhengzhou; Ge, Fengzeng; Chen, Wenhao; Shao, Wanxing; Liu, Bing; Cheng, Bei

    2016-09-01

    The issue of feature point mismatching among infrared image sequence would bring big challenge to estimating the relative motion of non-cooperative spacecraft for it couldn't provide the prior knowledge about its geometric structure and motion pattern. The paper introduces particle filter to precisely match the feature points within a desired region predicted by a kinetic equation, and presents a least square estimation-based algorithm to measure the relative rolling motion of non-cooperative spacecraft. The state transition equation and the measurement update equation of non-cooperative spacecraft are represented by establishing its kinetic equations, and then the relative pose measurement is converted to the maximum posteriori probability estimation via assuming the uncertainties about geometric structure and motion pattern as random and time-varying variables. These uncertainties would be interpreted and even solved through continuously measuring the image feature points of the rotating non-cooperative infrared spacecraft. Subsequently, the feature point is matched within a predicted region among sequence infrared image using particle filter algorithm to overcome the position estimation noise caused by the uncertainties of geometric structure and motion pattern. Finally, the position parameters including rotation motion are estimated by means of solving the minimum error of feature point mismatching using least square estimate theory. Both simulated and real infrared image sequences are induced in the experiment to evaluate the performance of the relative rolling estimation, and the experimental data show that the rolling motion estimated by the proposed algorithm is more robust to the feature extraction noise and various rotation speed. Meanwhile, the relative rolling estimation error would increase dramatically with distance and rotation speed increasing.

  19. Toward autonomous surface-based infrared remote sensing of polar clouds: cloud-height retrievals

    NASA Astrophysics Data System (ADS)

    Rowe, Penny M.; Cox, Christopher J.; Walden, Von P.

    2016-08-01

    Polar regions are characterized by their remoteness, making measurements challenging, but an improved knowledge of clouds and radiation is necessary to understand polar climate change. Infrared radiance spectrometers can operate continuously from the surface and have low power requirements relative to active sensors. Here we explore the feasibility of retrieving cloud height with an infrared spectrometer that would be designed for use in remote polar locations. Using a wide variety of simulated spectra of mixed-phase polar clouds at varying instrument resolutions, retrieval accuracy is explored using the CO2 slicing/sorting and the minimum local emissivity variance (MLEV) methods. In the absence of imposed errors and for clouds with optical depths greater than ˜ 0.3, cloud-height retrievals from simulated spectra using CO2 slicing/sorting and MLEV are found to have roughly equivalent high accuracies: at an instrument resolution of 0.5 cm-1, mean biases are found to be ˜ 0.2 km for clouds with bases below 2 and -0.2 km for higher clouds. Accuracy is found to decrease with coarsening resolution and become worse overall for MLEV than for CO2 slicing/sorting; however, the two methods have differing sensitivity to different sources of error, suggesting an approach that combines them. For expected errors in the atmospheric state as well as both instrument noise and bias of 0.2 mW/(m2 sr cm-1), at a resolution of 4 cm-1, average retrieval errors are found to be less than ˜ 0.5 km for cloud bases within 1 km of the surface, increasing to ˜ 1.5 km at 4 km. This sensitivity indicates that a portable, surface-based infrared radiance spectrometer could provide an important complement in remote locations to satellite-based measurements, for which retrievals of low-level cloud are challenging.

  20. [Passive detection of aeroengine exhaust based on Fourier transform infrared system].

    PubMed

    Li, Shao-cheng; Zuo, Hong-fu; Xia, Qing

    2008-10-01

    Since the composition and concentration of aeroengine exhaust can reflect the combustion efficiency, they can provide the basis for condition based maintenance, and also the basis for the analysis of environment pollution caused by aeroengine exhaust. So the importance of aeroengine exhaust detection is evident. Up to now, the measurement of aeroengine exhaust is based on sampling analysis which is not convenient and can't meet the detection requirements when an aeroplane is flying-off or flying in the sky. Hence, new methods of exhaust detection must be studied. The passive measurement technology based on Fourier transform infrared spectroscopy (FTIR) was applied to the measurement of aeroengine exhaust in the present paper. At first, the principle of passive measurement based on FTIR was introduced in detail. On this basis, a model algorithm for gas concentration calculation was deduced based on the principle of infrared transmission. Then the feasibility of aeroengine exhaust measurement based on passive FTIR was analyzed, and the passive measurement method of aeroengine exhaust based on FTIR was given. In the end, an experiment of aeroengine exhaust passive measurement was carried out by a FTIR with the type of Tensor 27 produced by BRUKER. Good quality spectra of the exhaust and the background were measured. Based on the model algo rithm of passive measurement, the absorbance spectra of CO and NO were obtained respectively, and the concentrations of CO and NO were figured out. To check up the veracity of this method, a comparison was made with another apparatus. There were only little differences between the results of the two experiments, showing that the passive measurement technology based on FTIR could meet the requirements of aeroengine exhaust detection.

  1. Limiting dark current mechanisms in antimony-based superlattice infrared detectors for the long-wavelength infrared regime

    NASA Astrophysics Data System (ADS)

    Rehm, Robert; Lemke, Florian; Schmitz, Johannes; Wauro, Matthias; Walther, Martin

    2015-06-01

    A detailed understanding of limiting dark current mechanisms in InAs/GaSb type-II superlattice (T2SL) infrared detectors is key to improve the electrooptical performance of these devices. We present a six-component dark current analysis which, for the first time, takes account of sidewall-related dark current contributions in mesa-etched T2SL photodiodes. In a wide temperature range from 30K to 130K, the paper compares limiting mechanisms in two homojunction T2SL photodiode wafers for the long-wavelength infrared regime. While the two epi wafers were fabricated with nominally the same frontside process they were grown on different molecular beam epitaxy systems. In the available literature a limitation by Shockley-Read-Hall processes in the space charge region giving rise to generation-recombination (GR) dark current is the prevailing verdict on the bulk dark current mechanism in T2SL homojunction photodiodes around 77K. In contrast, we find that investigated photodiode wafers are instead limited by the diffusion mechanism and the ohmic shunt component, respectively. Furthermore, our in-depth analysis of the various dark current components has led to an interesting observation on the temperature dependence of the shunt resistance in T2SL homojunction photodiodes. Our results indicate that the GR and the shunt mechanism share the same dependence on bandgap and temperature, i.e., a proportionality to exp(-Eg/2kT).

  2. Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data.

    PubMed

    Balabin, Roman M; Safieva, Ravilya Z

    2011-03-18

    The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000cm(-1)) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E=6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification. PMID:21397073

  3. High dynamic range infrared images detail enhancement based on local edge preserving filter

    NASA Astrophysics Data System (ADS)

    Song, Qiong; Wang, Yuehuan; Bai, Kun

    2016-07-01

    In the field of infrared (IR) image processing, displaying a high dynamic range (HDR) image on a low dynamic range display equipment with a natural visual effect, clear details on local areas and less artifacts is an important issue. In this paper, we present a new approach to display HDR IR images with contrast enhancement. First, the local edge-preserving filter (LEPF) is utilized to separate the image into a base layer and detail layer(s). After the filtering procedure, we use an adaptive Gamma transformation to adjust the gray distribution of the base layer, and stretch the detail layer based on a human visual effect principle. Then, we recombine the detail layer and base layer to obtain the enhance output. Finally, we adjust the luminance of output by applying multiple exposure fusion method. The experimental results demonstrate that our proposed method can provide a significant performance in terms of enhancing details and less artifacts than the state of the arts.

  4. Liquid scintillators with near infrared emission based on organoboron conjugated polymers.

    PubMed

    Tanaka, Kazuo; Yanagida, Takayuki; Yamane, Honami; Hirose, Amane; Yoshii, Ryousuke; Chujo, Yoshiki

    2015-11-15

    The organic liquid scintillators based on the emissive polymers are reported. A series of conjugated polymers containing organoboron complexes which show the luminescence in the near infrared (NIR) region were synthesized. The polymers showed good solubility in common organic solvents. From the comparison of the luminescent properties of the synthesized polymers between optical and radiation excitation, similar emission bands were detected. In addition, less significant degradation was observed. These data propose that the organoboron conjugated polymers are attractive platforms to work as an organic liquid scintillator with the emission in the NIR region.

  5. Design of mid-infrared ultra-wideband metallic absorber based on circuit theory

    NASA Astrophysics Data System (ADS)

    Arik, Kamalodin; Abdollahramezani, Sajjad; Farajollahi, Saeed; Khavasi, Amin; Rejaei, Behzad

    2016-12-01

    An ultra-broadband absorber of light is proposed by using periodic array of ultra-thin metallic ribbons on top of a lossless quarter-wavelength dielectric spacer placed on a metallic reflector. We propose a fully analytical circuit model for the structure, and then the absorber is duly designed based on the impedance matching concept. As a result, normalized bandwidth of 99.5% is realized by the proposed absorbing structure in mid-infrared regime. Performing a numerical optimization algorithm, we could also reach to normalized bandwidth of 103%.

  6. Robust infrared small target detection via non-negativity constraint-based sparse representation.

    PubMed

    Wan, Minjie; Gu, Guohua; Qian, Weixian; Ren, Kan; Chen, Qian

    2016-09-20

    Infrared (IR) small target detection is one of the vital techniques in many military applications, including IR remote sensing, early warning, and IR precise guidance. Over-complete dictionary based sparse representation is an effective image representation method that can capture geometrical features of IR small targets by the redundancy of the dictionary. In this paper, we concentrate on solving the problem of robust infrared small target detection under various scenes via sparse representation theory. First, a frequency saliency detection based preprocessing is developed to extract suspected regions that may possibly contain the target so that the subsequent computing load is reduced. Second, a target over-complete dictionary is constructed by a varietal two-dimensional Gaussian model with an extent feature constraint and a background term. Third, a sparse representation model with a non-negativity constraint is proposed for the suspected regions to calculate the corresponding coefficient vectors. Fourth, the detection problem is skillfully converted to an l1-regularized optimization through an accelerated proximal gradient (APG) method. Finally, based on the distinct sparsity difference, an evaluation index called sparse rate (SR) is presented to extract the real target by an adaptive segmentation directly. Large numbers of experiments demonstrate both the effectiveness and robustness of this method. PMID:27661588

  7. A ground-based near-infrared emission spectrum of the exoplanet HD 189733b.

    PubMed

    Swain, Mark R; Deroo, Pieter; Griffith, Caitlin A; Tinetti, Giovanna; Thatte, Azam; Vasisht, Gautam; Chen, Pin; Bouwman, Jeroen; Crossfield, Ian J; Angerhausen, Daniel; Afonso, Cristina; Henning, Thomas

    2010-02-01

    Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H(2)O), methane (CH(4)), carbon dioxide (CO(2)), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4-5.2 microm spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 microm and 3.1-4.1 microm, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at approximately 3.25 microm is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10(-6) bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH(4), similar to what is seen in the atmospheres of planets in our own Solar System. These results suggest that non-LTE effects may need to be considered when interpreting measurements of strongly irradiated exoplanets.

  8. Packet based serial link realized in FPGA dedicated for high resolution infrared image transmission

    NASA Astrophysics Data System (ADS)

    Bieszczad, Grzegorz

    2015-05-01

    In article the external digital interface specially designed for thermographic camera built in Military University of Technology is described. The aim of article is to illustrate challenges encountered during design process of thermal vision camera especially related to infrared data processing and transmission. Article explains main requirements for interface to transfer Infra-Red or Video digital data and describes the solution which we elaborated based on Low Voltage Differential Signaling (LVDS) physical layer and signaling scheme. Elaborated link for image transmission is built using FPGA integrated circuit with built-in high speed serial transceivers achieving up to 2500Gbps throughput. Image transmission is realized using proprietary packet protocol. Transmission protocol engine was described in VHDL language and tested in FPGA hardware. The link is able to transmit 1280x1024@60Hz 24bit video data using one signal pair. Link was tested to transmit thermal-vision camera picture to remote monitor. Construction of dedicated video link allows to reduce power consumption compared to solutions with ASIC based encoders and decoders realizing video links like DVI or packed based Display Port, with simultaneous reduction of wires needed to establish link to one pair. Article describes functions of modules integrated in FPGA design realizing several functions like: synchronization to video source, video stream packeting, interfacing transceiver module and dynamic clock generation for video standard conversion.

  9. A ground-based near-infrared emission spectrum of the exoplanet HD 189733b.

    PubMed

    Swain, Mark R; Deroo, Pieter; Griffith, Caitlin A; Tinetti, Giovanna; Thatte, Azam; Vasisht, Gautam; Chen, Pin; Bouwman, Jeroen; Crossfield, Ian J; Angerhausen, Daniel; Afonso, Cristina; Henning, Thomas

    2010-02-01

    Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H(2)O), methane (CH(4)), carbon dioxide (CO(2)), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4-5.2 microm spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 microm and 3.1-4.1 microm, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at approximately 3.25 microm is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10(-6) bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH(4), similar to what is seen in the atmospheres of planets in our own Solar System. These results suggest that non-LTE effects may need to be considered when interpreting measurements of strongly irradiated exoplanets. PMID:20130645

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

    PubMed

    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

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

    PubMed

    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. Research on a middle infrared and long infrared dual-band laser based on energy transferring from DF (v) to CO2 (0000)

    NASA Astrophysics Data System (ADS)

    Zhong, Wei; Yuan, Shengfu; Sun, Xu

    2013-05-01

    We propose a continuous wave (CW) middle infrared (MIR) and long infrared (LIR) dual-band laser based on energy transferring from DF (v) to CO2(0000). A total output power of 5W is achieved by the proposed dual-band laser consisted of DF gain medium module (DF module) and DF-CO2 gain medium module (DF-CO2 module). Technologies about the gain peak position, beam qualification are analyzed. The two modules use a common stable resonator and output mirror with nominal transmissivities of 3.5%-5% in the MIR band and 6%-10% in the LIR band. Spectra of dual-band laser are acquired.

  13. Virtual pinhole confocal microscope

    SciTech Connect

    George, J.S.; Rector, D.M.; Ranken, D.M.; Peterson, B.; Kesteron, J.

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  14. Thermal Lens Microscope

    NASA Astrophysics Data System (ADS)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  15. Microscopic structure of heterogeneous lipid-based formulations revealed by 13C high-resolution solid-state and 1H PFG NMR methods.

    PubMed

    Guillermo, Armel; Gerbaud, Guillaume; Bardet, Michel

    2010-03-01

    Lipid-based formulations such as lip glosses that are very alike on the base of their components may have significant differences in their expected macroscopic properties as cosmetics. To differentiate such formulations, high-resolution (13)C NMR was performed under magic angle spinning to investigate the properties at both molecular and microscopic levels. Temperature studies were carried out and no polymorphism in the solid domains could be evidenced after the thermal treatment performed for obtaining the commercial lip glosses. (13)C NMR spectra also showed that some waxes remain partially solubilized in the oils of formulations. The microscopic structure of the wax-oil liquid domains was worked out on the basis of restricted diffusion properties obtained with proton pulsed-field gradient NMR. Changing a single wax component, in two identical formulations, yields significant morphological differences. In the first one the liquid phase appears as a continuum whereas in the second one, the liquid phase is fractionated into micrometric droplets.

  16. Characterization of a subwavelength-scale 3D void structure using the FDTD-based confocal laser scanning microscopic image mapping technique.

    PubMed

    Choi, Kyongsik; Chon, James W; Gu, Min; Lee, Byoungho

    2007-08-20

    In this paper, a simple confocal laser scanning microscopic (CLSM) image mapping technique based on the finite-difference time domain (FDTD) calculation has been proposed and evaluated for characterization of a subwavelength-scale three-dimensional (3D) void structure fabricated inside polymer matrix. The FDTD simulation method adopts a focused Gaussian beam incident wave, Berenger's perfectly matched layer absorbing boundary condition, and the angular spectrum analysis method. Through the well matched simulation and experimental results of the xz-scanned 3D void structure, we first characterize the exact position and the topological shape factor of the subwavelength-scale void structure, which was fabricated by a tightly focused ultrashort pulse laser. The proposed CLSM image mapping technique based on the FDTD can be widely applied from the 3D near-field microscopic imaging, optical trapping, and evanescent wave phenomenon to the state-of-the-art bio- and nanophotonics.

  17. Upcoming and Future Missions in the Area of Infrared Astronomy: Spacecraft and Ground-based Observations

    NASA Technical Reports Server (NTRS)

    Sittler, E. C., Jr.

    2004-01-01

    will also be discussed. Improved thermal detectors could have important applications in solar physics, specifically in the detection of far-IR synchrotron emission from energetic electrons in solar flares. For infrared astronomy we have missions like SIRTF and JWST, which will cover the spectral range from near-IR to far-IR in the search and probing of both new and old planetary systems in our galaxy and the measurement of the most distant galaxies of our universe. SIRTF is scheduled to be launched in August 2003, while JWST will be launched next decade. Another mission is TPF, which will use interferometer techniques at infrared wavelengths to search for planetary systems beyond 2010. With regard to ground based telescopes we have, for example, the twin 10 meter Keck telescopes and the IRTF telescope at Mauna Kea. The Keck telescopes are presently using interferometer techniques. Over the next several decades there are plans for 50 meter to 200 meter telescopes providing near-IR to far-IR measurements with the eventual plan to combine all telescopes using interferometer techniques to provide unprecedented spectral-spatial resolution and sensitivity.

  18. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals

    PubMed Central

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-01

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector’s false alarms. PMID:26805837

  19. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals.

    PubMed

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-01

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector's false alarms. PMID:26805837

  20. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    NASA Astrophysics Data System (ADS)

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John

    2014-02-01

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  1. Infrared thermography for laser-based powder bed fusion additive manufacturing processes

    SciTech Connect

    Moylan, Shawn; Whitenton, Eric; Lane, Brandon; Slotwinski, John

    2014-02-18

    Additive manufacturing (AM) has the potential to revolutionize discrete part manufacturing, but improvements in processing of metallic materials are necessary before AM will see widespread adoption. A better understanding of AM processes, resulting from physics-based modeling as well as direct process metrology, will form the basis for these improvements. Infrared (IR) thermography of AM processes can provide direct process metrology, as well as data necessary for the verification of physics-based models. We review selected works examining how IR thermography was implemented and used in various powder-bed AM processes. This previous work, as well as significant experience at the National Institute of Standards and Technology in temperature measurement and IR thermography for machining processes, shapes our own research in AM process metrology with IR thermography. We discuss our experimental design, as well as plans for future IR measurements of a laser-based powder bed fusion AM process.

  2. Field-testing of a cost-effective mobile-phone based microscope for screening of Schistosoma haematobium infection (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ceylan Koydemir, Hatice; Bogoch, Isaac I.; Tseng, Derek; Ephraim, Richard K. D.; Duah, Evans; Tee, Joseph; Andrews, Jason R.; Ozcan, Aydogan

    2016-03-01

    Schistosomiasis is a parasitic and neglected tropical disease, and affects <200-million people across the world, with school-aged children disproportionately affected. Here we present field-testing results of a handheld and cost effective smartphone-based microscope in rural Ghana, Africa, for point-of-care diagnosis of S. haematobium infection. In this mobile-phone microscope, a custom-designed 3D printed opto-mechanical attachment (~150g) is placed in contact with the smartphone camera-lens, creating an imaging-system with a half-pitch resolution of ~0.87µm. This unit includes an external lens (also taken from a mobile-phone camera), a sample tray, a z-stage to adjust the focus, two light-emitting-diodes (LEDs) and two diffusers for uniform illumination of the sample. In our field-testing, 60 urine samples, collected from children, were used, where the prevalence of the infection was 72.9%. After concentration of the sample with centrifugation, the sediment was placed on a glass-slide and S. haematobium eggs were first identified/quantified using conventional benchtop microscopy by an expert diagnostician, and then a second expert, blinded to these results, determined the presence/absence of eggs using our mobile-phone microscope. Compared to conventional microscopy, our mobile-phone microscope had a diagnostic sensitivity of 72.1%, specificity of 100%, positive-predictive-value of 100%, and a negative-predictive-value of 57.1%. Furthermore, our mobile-phone platform demonstrated a sensitivity of 65.7% and 100% for low-intensity infections (≤50 eggs/10 mL urine) and high-intensity infections (<50 eggs/10 mL urine), respectively. We believe that this cost-effective and field-portable mobile-phone microscope may play an important role in the diagnosis of schistosomiasis and various other global health challenges.

  3. Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology

    PubMed Central

    Yin, C.; Glaser, A.K.; Leigh, S. Y.; Chen, Y.; Wei, L.; Pillai, P. C. S.; Rosenberg, M. C.; Abeytunge, S.; Peterson, G.; Glazowski, C.; Sanai, N.; Mandella, M. J.; Rajadhyaksha, M.; Liu, J. T. C.

    2016-01-01

    There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device. PMID:26977337

  4. Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology.

    PubMed

    Yin, C; Glaser, A K; Leigh, S Y; Chen, Y; Wei, L; Pillai, P C S; Rosenberg, M C; Abeytunge, S; Peterson, G; Glazowski, C; Sanai, N; Mandella, M J; Rajadhyaksha, M; Liu, J T C

    2016-02-01

    There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device. PMID:26977337

  5. [A method of hyperspectral quantificational identification of minerals based on infrared spectral artificial immune calculation].

    PubMed

    Liu, Qing-Jie; Jing, Lin-Hai; Li, Xin-Wu; Bi, Jian-Tao; Wang, Meng-Fei; Lin, Qi-Zhong

    2013-04-01

    Rapid identification of minerals based on near infrared (NIR) and shortwave infrared (SWIR) hyperspectra is vital to remote sensing mine exploration, remote sensing minerals mapping and field geological documentation of drill core, and have leaded to many identification methods including spectral angle mapping (SAM), spectral distance mapping (SDM), spectral feature fitting(SFF), linear spectral mixture model (LSMM), mathematical combination feature spectral linear inversion model(CFSLIM) etc. However, limitations of these methods affect their actual applications. The present paper firstly gives a unified minerals components spectral inversion (MCSI) model based on target sample spectrum and standard endmember spectral library evaluated by spectral similarity indexes. Then taking LSMM and SAM evaluation index for example, a specific formulation of unified MCSI model is presented in the form of a kind of combinatorial optimization. And then, an artificial immune colonial selection algorithm is used for solving minerals feature spectral linear inversion model optimization problem, which is named ICSFSLIM. Finally, an experiment was performed to use ICSFSLIM and CFSLIM to identify the contained minerals of 22 rock samples selected in Baogutu in Xinjiang China. The mean value of correctness and validness identification of ICSFSLIM are 34.22% and 54.08% respectively, which is better than that of CFSLIM 31.97% and 37.38%; the correctness and validness variance of ICSFSLIM are 0.11 and 0.13 smaller than that of CFSLIM, 0.15 and 0.25, indicating better identification stability.

  6. Identification of forensic samples by using an infrared-based automatic DNA sequencer.

    PubMed

    Ricci, Ugo; Sani, Ilaria; Klintschar, Michael; Cerri, Nicoletta; De Ferrari, Francesco; Giovannucci Uzielli, Maria Luisa

    2003-06-01

    We have recently introduced a new protocol for analyzing all core loci of the Federal Bureau of Investigation's (FBI) Combined DNA Index System (CODIS) with an infrared (IR) automatic DNA sequencer (LI-COR 4200). The amplicons were labeled with forward oligonucleotide primers, covalently linked to a new infrared fluorescent molecule (IRDye 800). The alleles were displayed as familiar autoradiogram-like images with real-time detection. This protocol was employed for paternity testing, population studies, and identification of degraded forensic samples. We extensively analyzed some simulated forensic samples and mixed stains (blood, semen, saliva, bones, and fixed archival embedded tissues), comparing the results with donor samples. Sensitivity studies were also performed for the four multiplex systems. Our results show the efficiency, reliability, and accuracy of the IR system for the analysis of forensic samples. We also compared the efficiency of the multiplex protocol with ultraviolet (UV) technology. Paternity tests, undegraded DNA samples, and real forensic samples were analyzed with this approach based on IR technology and with UV-based automatic sequencers in combination with commercially-available kits. The comparability of the results with the widespread UV methods suggests that it is possible to exchange data between laboratories using the same core group of markers but different primer sets and detection methods.

  7. [Validation of HJ-1B thermal infrared channels onboard radiometric calibration based on spectral response differences].

    PubMed

    Liu, Li; Fu, Qiao-yan; Shi, Ting-ting; Wang, Ai-chun; Zhang, Xue-wen

    2014-08-01

    Since HJ-1B was launched, 7 sets of blackbody data have been used to calculate onboard calibration coefficients, but the research work on the validation of coefficients is rare. According to the onboard calibration principle, calibration coefficients of HJ-1B thermal infrared channel on Sep 14th, 2009 were calculated with the half-width, moments and look-up table methods. MODIS was selected for the reference sensor, and algorithms of spectral match were improved between the HJ-1B thermal infrared channel and MODIS 31, 32 channels based on the spectral response divergence. The relationship of top of atmosphere (TOA) radiance between the remote sensors was calculated, based on which the surface leaving brightness temperature was calculated by Planck function to validate the brightness temperature calculated through the onboard calibration coefficients. The equivalent brightness temperature calculated by spectral response divergence method is 285.97 K, and the inversion brightness temperature calculated by half-width, moments and look-up table methods is 288.77, 274.52 and 285.97 K respectively. The difference between the inversion brightness temperature and the equivalent brightness temperature is 2.8, -11.46 and 0.02 K, respectively, which demonstrate that onboard calibration coefficients calculated by the look-up table method has better precision and feasibility.

  8. Bonding surgical incisions using a temperature-controlled laser system based on a single infrared fiber.

    PubMed

    Gabay, Ilan; Barequet, Irina; Varssano, David; Rosner, Mordechai; Katzir, Abraham

    2013-11-01

    ABSTRACT. Although there has been great interest in laser heating for bonding of surgical incisions in tissues, it has not gained wide acceptance by surgeons. We argue that the main obstacle has been the lack of temperature control, which may lead to a weak bonding. We previously developed a laser bonding system based on two infrared transmitting AgBrCl fibers, one for laser heating and one for temperature control. In view of the inherent limitations of such systems observed in many animal experiments, we developed an improved system based on a single infrared fiber. Besides the decreased dimensions, this system offers many advantages over the two-fiber system. It is less sensitive to accuracy of height and tilt of the fiber distal tip above the tissue, ensuring more accurate heating that can potentially lead to stronger bonding with minimal thermal damage. The system is successfully tested in the soldering of 15 corneal incisions, ex vivo. Histopathology shows little thermal damage and good wound apposition. The average burst pressure is 100±30  mm Hg. These findings indicate the usefulness of the system for ophthalmic surgery as well as other surgical procedures, including endoscopic and robotic surgery.

  9. [Validation of HJ-1B thermal infrared channels onboard radiometric calibration based on spectral response differences].

    PubMed

    Liu, Li; Fu, Qiao-yan; Shi, Ting-ting; Wang, Ai-chun; Zhang, Xue-wen

    2014-08-01

    Since HJ-1B was launched, 7 sets of blackbody data have been used to calculate onboard calibration coefficients, but the research work on the validation of coefficients is rare. According to the onboard calibration principle, calibration coefficients of HJ-1B thermal infrared channel on Sep 14th, 2009 were calculated with the half-width, moments and look-up table methods. MODIS was selected for the reference sensor, and algorithms of spectral match were improved between the HJ-1B thermal infrared channel and MODIS 31, 32 channels based on the spectral response divergence. The relationship of top of atmosphere (TOA) radiance between the remote sensors was calculated, based on which the surface leaving brightness temperature was calculated by Planck function to validate the brightness temperature calculated through the onboard calibration coefficients. The equivalent brightness temperature calculated by spectral response divergence method is 285.97 K, and the inversion brightness temperature calculated by half-width, moments and look-up table methods is 288.77, 274.52 and 285.97 K respectively. The difference between the inversion brightness temperature and the equivalent brightness temperature is 2.8, -11.46 and 0.02 K, respectively, which demonstrate that onboard calibration coefficients calculated by the look-up table method has better precision and feasibility. PMID:25508743

  10. [Validation of HJ-1B thermal infrared channels onboard radiometric calibration based on spectral response differences].

    PubMed

    Liu, Li; Fu, Qiao-yan; Shi, Ting-ting; Wang, Ai-chun; Zhang, Xue-wen

    2014-08-01

    Since HJ-1B was launched, 7 sets of blackbody data have been used to calculate onboard calibration coefficients, but the research work on the validation of coefficients is rare. According to the onboard calibration principle, calibration coefficients of HJ-1B thermal infrared channel on Sep 14th, 2009 were calculated with the half-width, moments and look-up table methods. MODIS was selected for the reference sensor, and algorithms of spectral match were improved between the HJ-1B thermal infrared channel and MODIS 31, 32 channels based on the spectral response divergence. The relationship of top of atmosphere (TOA) radiance between the remote sensors was calculated, based on which the surface leaving brightness temperature was calculated by Planck function to validate the brightness temperature calculated through the onboard calibration coefficients. The equivalent brightness temperature calculated by spectral response divergence method is 285.97 K, and the inversion brightness temperature calculated by half-width, moments and look-up table methods is 288.77, 274.52 and 285.97 K respectively. The difference between the inversion brightness temperature and the equivalent brightness temperature is 2.8, -11.46 and 0.02 K, respectively, which demonstrate that onboard calibration coefficients calculated by the look-up table method has better precision and feasibility. PMID:25474964

  11. UV-laser-based microscopic dissection of tree rings - a novel sampling tool for δ(13) C and δ(18) O studies.

    PubMed

    Schollaen, Karina; Heinrich, Ingo; Helle, Gerhard

    2014-02-01

    UV-laser-based microscopic systems were utilized to dissect and sample organic tissue for stable isotope measurements from thin wood cross-sections. We tested UV-laser-based microscopic tissue dissection in practice for high-resolution isotopic analyses (δ(13) C/δ(18) O) on thin cross-sections from different tree species. The method allows serial isolation of tissue of any shape and from millimetre down to micrometre scales. On-screen pre-defined areas of interest were automatically dissected and collected for mass spectrometric analysis. Three examples of high-resolution isotopic analyses revealed that: in comparison to δ(13) C of xylem cells, woody ray parenchyma of deciduous trees have the same year-to-year variability, but reveal offsets that are opposite in sign depending on whether wholewood or cellulose is considered; high-resolution tree-ring δ(18) O profiles of Indonesian teak reflect monsoonal rainfall patterns and are sensitive to rainfall extremes caused by ENSO; and seasonal moisture signals in intra-tree-ring δ(18) O of white pine are weighted by nonlinear intra-annual growth dynamics. The applications demonstrate that the use of UV-laser-based microscopic dissection allows for sampling plant tissue at ultrahigh resolution and unprecedented precision. This new technique facilitates sampling for stable isotope analysis of anatomical plant traits like combined tree eco-physiological, wood anatomical and dendroclimatological studies. PMID:24219751

  12. [Freshwater fish freshness on-line detection method based on near-infrared spectroscopy].

    PubMed

    Huang, Tao; Li, Xiao-Yu; Peng, Yi; Tao, Hai-Long; Li, Peng; Xiong, Shan-Bai

    2014-10-01

    In the present study, the near infrared spectrum of freshwater fish was used to detect the freshness on line, and the near infrared spectra on-line acquisition device was built to get the fish spectrum. In the process of spectrum acquisition, experiment samples move at a speed of 0.5 m · s(-1), the near-infrared diffuse reflection spectrum (900-2,500 nm) could be got for the next analyzing, and SVM was used to build on-line detection model. Sample set partitioning based on joint X-Y distances algo- rithm (SPXY) was used to divide sample set, there were 111 samples in calibration set (57 fresh samples and 54 bad samples), and 37 samples in test set (19 fresh samples and 18 bad samples). Seven spectral preprocessing methods were utilized to prepro- cess the spectrum, and the influences of different methods were compared. Model results indicated that first derivative (FD) with autoscale was the best preprocessing method, the model recognition rate of calibration set was 97.96%, and the recognition rate of test set was 95.92%. In order to improve the modeling speed, it is necessary to optimize the spectra variables. Therefore genetic algorithm (GA), successive projection algorithm (SPA) and competitive adaptive reweighed sampling (CARS) were adopted to select characteristic variables respectively. Finally CARS was proved to be the optimal variable selection method, 10 characteristic wavelengths were selected to develop SVM model, recognition rate of calibration set reached 100%, and recognition rate of test set was 93.88%. The research provided technical reference for freshwater fish freshness online detection.

  13. [Testing of germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy].

    PubMed

    Li, Yi-nian; Jiang, Dan; Liu, Ying-ying; Ding, Wei-min; Ding, Qi-shuo; Zha, Liang-yu

    2014-06-01

    Germination rate of rice seeds was measured according to technical stipulation of germination testing for agricultural crop seeds at present. There existed many faults for this technical stipulation such as long experimental period, more costing and higher professional requirement. A rapid and non-invasive method was put forward to measure the germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy. Two varieties of hybrid rice seeds were aged artificially at temperature 45 degrees C and humidity 100% condition for 0, 24, 48, 72, 96, 120 and 144 h. Spectral data of 280 samples for 2 varieties of hybrid rice seeds with different aging time were acquired individually by near-infrared spectra analyzer. Spectral data of 280 samples for 2 varieties of hybrid rice seeds were randomly divided into calibration set (168 samples) and prediction set (112 samples). Gormination rate of rice seed with different aging time was tested. Regression model was established by using partial least squares (PLS). The effect of the different spectral bands on the accuracy of models was analyzed and the effect of the different spectral preprocessing methods on the accuracy of models was also compared. Optimal model was achieved under the whole bands and by using standardization and orthogonal signal correction (OSC) preprocessing algorithms with CM2000 software for spectral data of 2 varieties of hybrid rice seeds, the coefficient of determination of the calibration set (Rc) and that of the prediction set (Rp) were 0.965 and 0.931 individually, standard error of calibration set (SEC) and that of prediction set (SEP) were 1.929 and 2.899 respectively. Relative error between tested value and predicted value for prediction set of rice seeds is below 4.2%. The experimental results show that it is feasible that rice germination rate is detected rapidly and nondestructively by using the near-infrared spectroscopy analysis technology. PMID:25358159

  14. Near-infrared emission spectrometry based on an acousto-optical tunable filter.

    PubMed

    Gonzaga, Fabiano Barbieri; Pasquini, Celio

    2005-02-15

    A spectrometer has been constructed to detect the radiation emitted by thermally excited samples in the near-infrared spectral region extending from 1500 to 3000 nm. The instrument employs an acousto-optical tunable filter (AOTF) made of TeO2 and attains maximum sensitivity by making effective use of the two diffracted beams produced by the anisotropic AOTF. The full exploitation of the transmitted power of the monochromatic beams is reported for the first time and became possible because the detector does not saturate when employed for the acquisition of the weak emission signal in the NIR region, even when exposed to the total (nondiffracted) beam. Thus, modulation and lock-in-based detection can be employed to find the intensity of the diffracted beams superimposed on the nondiffracted beam. The resolution is slighted degraded in view of the small (approximately 10 nm) difference in the wavelength diffracted in the ordinary and extraordinary beams. The instrument has been evaluated in terms of signal-to-noise ratio, effect of sample thickness, and excitation temperature and for its potential in analytical applications in monitoring high-temperature kinetics, for qualitative identification of inorganic solids, for use with a closed cell to obtain spectra of species that evaporate at the temperatures (> 150 degrees C) necessary for sample excitation, and for quantitative purposes in the determination of soybean oil content in olive oil. The feasibility of near-infrared emission spectroscopy has been demonstrated together with some of its advantages over mid-infrared emission spectroscopy, such as greater tolerance to sample thickness, suitable signal-to-noise, and its use in the investigation of kinetic phenomena and phase transitions at high temperatures.

  15. [Testing of germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy].

    PubMed

    Li, Yi-nian; Jiang, Dan; Liu, Ying-ying; Ding, Wei-min; Ding, Qi-shuo; Zha, Liang-yu

    2014-06-01

    Germination rate of rice seeds was measured according to technical stipulation of germination testing for agricultural crop seeds at present. There existed many faults for this technical stipulation such as long experimental period, more costing and higher professional requirement. A rapid and non-invasive method was put forward to measure the germination rate of hybrid rice seeds based on near-infrared reflectance spectroscopy. Two varieties of hybrid rice seeds were aged artificially at temperature 45 degrees C and humidity 100% condition for 0, 24, 48, 72, 96, 120 and 144 h. Spectral data of 280 samples for 2 varieties of hybrid rice seeds with different aging time were acquired individually by near-infrared spectra analyzer. Spectral data of 280 samples for 2 varieties of hybrid rice seeds were randomly divided into calibration set (168 samples) and prediction set (112 samples). Gormination rate of rice seed with different aging time was tested. Regression model was established by using partial least squares (PLS). The effect of the different spectral bands on the accuracy of models was analyzed and the effect of the different spectral preprocessing methods on the accuracy of models was also compared. Optimal model was achieved under the whole bands and by using standardization and orthogonal signal correction (OSC) preprocessing algorithms with CM2000 software for spectral data of 2 varieties of hybrid rice seeds, the coefficient of determination of the calibration set (Rc) and that of the prediction set (Rp) were 0.965 and 0.931 individually, standard error of calibration set (SEC) and that of prediction set (SEP) were 1.929 and 2.899 respectively. Relative error between tested value and predicted value for prediction set of rice seeds is below 4.2%. The experimental results show that it is feasible that rice germination rate is detected rapidly and nondestructively by using the near-infrared spectroscopy analysis technology.

  16. An adaptive fusion approach for infrared and visible images based on NSCT and compressed sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Qiong; Maldague, Xavier

    2016-01-01

    A novel nonsubsampled contourlet transform (NSCT) based image fusion approach, implementing an adaptive-Gaussian (AG) fuzzy membership method, compressed sensing (CS) technique, total variation (TV) based gradient descent reconstruction algorithm, is proposed for the fusion computation of infrared and visible images. Compared with wavelet, contourlet, or any other multi-resolution analysis method, NSCT has many evident advantages, such as multi-scale, multi-direction, and translation invariance. As is known, a fuzzy set is characterized by its membership function (MF), while the commonly known Gaussian fuzzy membership degree can be introduced to establish an adaptive control of the fusion processing. The compressed sensing technique can sparsely sample the image information in a certain sampling rate, and the sparse signal can be recovered by solving a convex problem employing gradient descent based iterative algorithm(s). In the proposed fusion process, the pre-enhanced infrared image and the visible image are decomposed into low-frequency subbands and high-frequency subbands, respectively, via the NSCT method as a first step. The low-frequency coefficients are fused using the adaptive regional average energy rule; the highest-frequency coefficients are fused using the maximum absolute selection rule; the other high-frequency coefficients are sparsely sampled, fused using the adaptive-Gaussian regional standard deviation rule, and then recovered by employing the total variation based gradient descent recovery algorithm. Experimental results and human visual perception illustrate the effectiveness and advantages of the proposed fusion approach. The efficiency and robustness are also analyzed and discussed through different evaluation methods, such as the standard deviation, Shannon entropy, root-mean-square error, mutual information and edge-based similarity index.

  17. Selecting the quality of mule duck fatty liver based on near-infrared spectroscopy

    PubMed Central

    2014-01-01

    Background “Foie gras” is produced predominantly in France and about 90% of the commercialized product is obtained from male mule ducks. The melting rate (percentage of fat released during cooking) is the main criterion used to determine the quality of “foie gras”. However, up to now the melting rate could not be predicted without causing liver damage, which means that selection programs could not use this criterion. Methods Fatty liver phenotypes were obtained for a population of over 1400 overfed male mule ducks. The phenotypes were based on two types of near-infrared spectra (on the liver surface and on ground liver) in order to predict the melting rate and liver composition (ash, dry matter, lipid and protein contents). Genetic parameters were computed in multiple traits with a “sire-dam” model and using a Gibbs sampling approach. Results The estimates for the genetic parameters show that the measured melting rate and the predicted melting rate obtained with two near-infrared spectrometer devices are genetically the same trait: genetic correlations are very high (ranging from +0.89 to +0.97 depending on the mule duck parental line and the spectrometer) and heritabilities are comparable. The predictions based on the spectra of ground liver samples using a laboratory spectrometer correlate with those based on the surface spectra using a portable spectrometer (from +0.83 to +0.95 for dry matter, lipid and protein content) and are particularly high for the melting rate (higher than +0.95). Although less accurate than the predictions obtained using the spectra of ground liver samples, the phenotypic prediction of the melting rate based on surface spectra is sufficiently accurate to be used by “foie gras” processors. Conclusions Near-infrared spectrometry is an efficient tool to select liver quality in breeding programs because animals can be ranked according to their liver melting rate without damaging their livers. Thus, these original results will

  18. Precise autofocusing microscope with rapid response

    NASA Astrophysics Data System (ADS)

    Liu, Chien-Sheng; Jiang, Sheng-Hong

    2015-03-01

    The rapid on-line or off-line automated vision inspection is a critical operation in the manufacturing fields. Accordingly, this present study designs and characterizes a novel precise optics-based autofocusing microscope with a rapid response and no reduction in the focusing accuracy. In contrast to conventional optics-based autofocusing microscopes with centroid method, the proposed microscope comprises a high-speed rotating optical diffuser in which the variation of the image centroid position is reduced and consequently the focusing response is improved. The proposed microscope is characterized and verified experimentally using a laboratory-built prototype. The experimental results show that compared to conventional optics-based autofocusing microscopes, the proposed microscope achieves a more rapid response with no reduction in the focusing accuracy. Consequently, the proposed microscope represents another solution for both existing and emerging industrial applications of automated vision inspection.

  19. Multitarget tracking system based on an infrared fish-eye lens.

    PubMed

    Li, Gang; Li, Li; Shen, Hongbin; He, Yongqiang; Huang, Jingxia; Mao, Shaojuan; Wang, Yuanbo

    2013-11-20

    A multitarget tracking system based on an infrared (IR) fish-eye lens is built to satisfy urgent requirements of large-field IR, multitarget, real-time reconnaissance and tracking. Utilizing an IR fish-eye lens and a 512×512 pixel PtSi detector, the system can detect threatening targets at the whole space domain and the whole time domain. The hardware of the system based on a dual-digital signal processor is designed to implement data processing for multitarget tracking algorithms, which include a track initiation algorithm and a modified generalized probability data association algorithm. We also carried out a tracking experiment for two aerial maneuvering targets. Comparing the theoretical and experimental tracks, the availability of the system and the real-time capability of multitarget tracking are validated.

  20. A near-Infrared Fluorescent Chemodosimeter for Ratiometric Detecting Fluoride Based on Desilylation Reaction.

    PubMed

    Xie, Puhui; Guo, Fengqi; Gao, Guangqin; Fan, Wei; Yang, Guoyu; Xie, Lixia

    2016-09-01

    A new chemodosimeter based on dicyanomethylene-4H-chromene chromophore (probe 1) was developed as a ratiometric fluorescent probe in near-infrared range for F(-) with good selectivity in acetonitrile. Probe 1 could be used to directly visualize F(-) by the naked eye and showed more than 621-fold fluorescence enhancement at 715 nm upon reaction with F(-) upon excitation at 625 nm. The recognition of probe 1 to fluoride was featured by F(-)-induced red-shifts of both absorption (185 nm) and fluorescence peaks (132 nm) based on internal charge transfer (ICT) in acetonitrile. The desilylation reaction of 1 by F(-) was proposed for its dual absorption and emission ratiometric detection of fluoride. PMID:27365125

  1. [Correction method for infrared spectral emissivity measurement system based on integrating sphere reflectometer].

    PubMed

    Zhang, Yu-Feng; Dai, Jing-Min; Zhang, Yu; Pan, Wei-Dong; Zhang, Lei

    2013-08-01

    In view of the influence of non-ideal reference standard on spectral emissivity measurement, by analyzing the principle of infrared emissivity measurement system based on integrating sphere reflectometer, a calibration method suitable for measuring spectral emissivity system using the reflection measurement was proposed. By fitting a spectral reflectance curve of the reference standard sample to the given reflectance data, the correction coefficient of measurement system was computed. Then the output voltage curve of reference standard sample was corrected by this coefficient. The system error caused by the imperfection of reference standard was eliminated. The correction method was applied to the spectral emissivity measurement system based on integrating sphere reflectometer. The results measured by the corrected system and the results measured by energy comparison measurement were compared to verify the feasibility and effectivity of this correction method in improving the accuracy of spectral emissivity measurement.

  2. Calibration diagnostic and updating strategy based on quantitative modeling of near-infrared spectral residuals.

    PubMed

    Yu, Hua; Small, Gary W

    2015-02-01

    A diagnostic and updating strategy is explored for multivariate calibrations based on near-infrared spectroscopy. For use with calibration models derived from spectral fitting or decomposition techniques, the proposed method constructs models that relate the residual concentrations remaining after a prediction to the residual spectra remaining after the information associated with the calibration model has been extracted. This residual modeling approach is evaluated for use with partial least-squares (PLS) models for predicting physiological levels of glucose in a simulated biological matrix. Residual models are constructed with both PLS and a hybrid technique based on the use of PLS scores as inputs to support vector regression. Calibration and residual models are built with both absorbance and single-beam data collected over 416 days. Effective models for the spectral residuals are built with both types of data and demonstrate the ability to diagnose and correct deviations in performance of the calibration model with time. PMID:25473807

  3. Physics Based Modeling and Rendering of Vegetation in the Thermal Infrared

    NASA Technical Reports Server (NTRS)

    Smith, J. A.; Ballard, J. R., Jr.

    1999-01-01

    We outline a procedure for rendering physically-based thermal infrared images of simple vegetation scenes. Our approach incorporates the biophysical processes that affect the temperature distribution of the elements within a scene. Computer graphics plays a key role in two respects. First, in computing the distribution of scene shaded and sunlit facets and, second, in the final image rendering once the temperatures of all the elements in the scene have been computed. We illustrate our approach for a simple corn scene where the three-dimensional geometry is constructed based on measured morphological attributes of the row crop. Statistical methods are used to construct a representation of the scene in agreement with the measured characteristics. Our results are quite good. The rendered images exhibit realistic behavior in directional properties as a function of view and sun angle. The root-mean-square error in measured versus predicted brightness temperatures for the scene was 2.1 deg C.

  4. Design of readout circuit for microcantilever-based ripple uncooled infrared focal plane arrays

    NASA Astrophysics Data System (ADS)

    Cao, Junmin; Chen, Zhongjian; Lu, Wengao; Zhang, Yacong; Lei, Ke; Zhao, Baoying

    2009-07-01

    A readout integrated circuit (ROIC) for uncooled microcantilever infrared focal plane arrays (IRFPAs) based on capacitive readout is proposed. The ROIC is optimized according to noise modeling and analysis to reduce noise. An experimental chip of 16×16 FPAs readout circuit has been designed and fabricated using 0.35um CMOS technology. The measurement results showed that the power dissipation is 16.5mW from a 5V supply voltage at 50Hz frame rate, the linearity is 99.2% at the typical mode; the uniformity is larger than 97% and the equivalent noise charge (ENC) is below 150e. It is believed that the ROIC has a great potential in the applications of large-scale micro-cantilever-based uncooled IRFPAs.

  5. Flag-based detection of weak gas signatures in long-wave infrared hyperspectral image sequences

    NASA Astrophysics Data System (ADS)

    Marrinan, Timothy; Beveridge, J. Ross; Draper, Bruce; Kirby, Michael; Peterson, Chris

    2016-05-01

    We present a flag manifold based method for detecting chemical plumes in long-wave infrared hyperspectral movies. The method encodes temporal and spatial information related to a hyperspectral pixel into a flag, or nested sequence of linear subspaces. The technique used to create the flags pushes information about the background clutter, ambient conditions, and potential chemical agents into the leading elements of the flags. Exploiting this temporal information allows for a detection algorithm that is sensitive to the presence of weak signals. This method is compared to existing techniques qualitatively on real data and quantitatively on synthetic data to show that the flag-based algorithm consistently performs better on data when the SINRdB is low, and beats the ACE and MF algorithms in probability of detection for low probabilities of false alarm even when the SINRdB is high.

  6. Intensity tunable infrared broadband absorbers based on VO2 phase transition using planar layered thin films

    PubMed Central

    Kocer, Hasan; Butun, Serkan; Palacios, Edgar; Liu, Zizhuo; Tongay, Sefaattin; Fu, Deyi; Wang, Kevin; Wu, Junqiao; Aydin, Koray

    2015-01-01

    Plasmonic and metamaterial based nano/micro-structured materials enable spectrally selective resonant absorption, where the resonant bandwidth and absorption intensity can be engineered by controlling the size and geometry of nanostructures. Here, we demonstrate a simple, lithography-free approach for obtaining a resonant and dynamically tunable broadband absorber based on vanadium dioxide (VO2) phase transition. Using planar layered thin film structures, where top layer is chosen to be an ultrathin (20 nm) VO2 film, we demonstrate broadband IR light absorption tuning (from ~90% to ~30% in measured absorption) over the entire mid-wavelength infrared spectrum. Our numerical and experimental results indicate that the bandwidth of the absorption bands can be controlled by changing the dielectric spacer layer thickness. Broadband tunable absorbers can find applications in absorption filters, thermal emitters, thermophotovoltaics and sensing. PMID:26294085

  7. Fast Measurement of Soluble Solid Content in Mango Based on Visible and Infrared Spectroscopy Technique

    NASA Astrophysics Data System (ADS)

    Yu, Jiajia; He, Yong

    Mango is a kind of popular tropical fruit, and the soluble solid content is an important in this study visible and short-wave near-infrared spectroscopy (VIS/SWNIR) technique was applied. For sake of investigating the feasibility of using VIS/SWNIR spectroscopy to measure the soluble solid content in mango, and validating the performance of selected sensitive bands, for the calibration set was formed by 135 mango samples, while the remaining 45 mango samples for the prediction set. The combination of partial least squares and backpropagation artificial neural networks (PLS-BP) was used to calculate the prediction model based on raw spectrum data. Based on PLS-BP, the determination coefficient for prediction (Rp) was 0.757 and root mean square and the process is simple and easy to operate. Compared with the Partial least squares (PLS) result, the performance of PLS-BP is better.

  8. Identification of Structural Motifs of Imidazolium Based Ionic Liquids from Jet-Cooled Infrared Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Young, Justin W.; Booth, Ryan S.; Annesley, Christopher; Stearns, Jaime A.

    2016-06-01

    Highly variable and potentially revolutionary, ionic liquids (IL) are a class of molecules with potential for numerous Air Force applications such as satellite propulsion, but the complex nature of IL structure and intermolecular interactions makes it difficult to adequately predict structure-property relationships in order to make new IL-based technology a reality. For example, methylation of imidazolium ionic liquids leads to a substantial increase in viscosity but the underlying physical mechanism is not understood. In addition the role of hydrogen bonding in ILs, especially its relationship to macroscopic properties, is a matter of ongoing research. Here, structural motifs are identified from jet-cooled infrared spectra of different imidazolium based ionic liquids, such as 1-ethyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide. Measurements of the C-H stretches indicate three structural families present in the gas phase.

  9. Infrared ground-based astronomy with the Hughes 256 X 256 PtSi array

    NASA Technical Reports Server (NTRS)

    Fowler, A.; Joyce, R.; Gatley, I.; Gates, J.; Herring, J.

    1989-01-01

    It is shown that large format PtSi Schottky diode infrared arrays, the Hughes 256 X 256 hybrid Schottky array in particular, are competitive alternatives to the smaller format photovoltaic arrays for ground-based astronomy. The modest quantum efficiency of the PtSi compared to the photovoltaic devices is more than compensated for by the larger format. The use of hybrid technology yields effective fill factors of nearly 100 percent, and the low dark current, noise, excellent imaging characteristics, cost, and solid nitrogen operating temperature add to the effectiveness of this array for ground-based imaging. In addition to discussing the characteristics of this array, researchers present laboratory test data and astronomical results achieved at Kitt Peak.

  10. About the scheme of the infrared FEL system for the accelerator based on HF wells

    SciTech Connect

    Kabanov, V.S.; Dzergach, A.I.

    1995-12-31

    Accelerators, based on localization of plasmoids in the HF wells (RF traps) of the axially-symmetric electromagnetic field E {sub omn} in an oversized (m,n>>1) resonant system, can give accelerating gradients {approximately}100 kV/{lambda}, e.g. 10 GV/m if {lambda}=10 {mu}m. One of possible variants of HF feeding for these accelerators is based on using the powerful infrared FEL System with 2 frequencies. The corresponding FEL`s may be similar to the Los Alamos compact Advanced FEL ({lambda}{sub 1,2}{approximately}10 pm, e-beam energy {approximately}15 MeV, e-beam current {approximately}100 A). Their power is defined mainly by the HF losses in the resonant system of the supposed accelerator.

  11. A Ground-Based Near Infrared Camera Array System for UAV Auto-Landing in GPS-Denied Environment

    PubMed Central

    Yang, Tao; Li, Guangpo; Li, Jing; Zhang, Yanning; Zhang, Xiaoqiang; Zhang, Zhuoyue; Li, Zhi

    2016-01-01

    This paper proposes a novel infrared camera array guidance system with capability to track and provide real time position and speed of a fixed-wing Unmanned air vehicle (UAV) during a landing process. The system mainly include three novel parts: (1) Infrared camera array and near infrared laser lamp based cooperative long range optical imaging module; (2) Large scale outdoor camera array calibration module; and (3) Laser marker detection and 3D tracking module. Extensive automatic landing experiments with fixed-wing flight demonstrate that our infrared camera array system has the unique ability to guide the UAV landing safely and accurately in real time. Moreover, the measurement and control distance of our system is more than 1000 m. The experimental results also demonstrate that our system can be used for UAV automatic accurate landing in Global Position System (GPS)-denied environments. PMID:27589755

  12. A Ground-Based Near Infrared Camera Array System for UAV Auto-Landing in GPS-Denied Environment.

    PubMed

    Yang, Tao; Li, Guangpo; Li, Jing; Zhang, Yanning; Zhang, Xiaoqiang; Zhang, Zhuoyue; Li, Zhi

    2016-08-30

    This paper proposes a novel infrared camera array guidance system with capability to track and provide real time position and speed of a fixed-wing Unmanned air vehicle (UAV) during a landing process. The system mainly include three novel parts: (1) Infrared camera array and near infrared laser lamp based cooperative long range optical imaging module; (2) Large scale outdoor camera array calibration module; and (3) Laser marker detection and 3D tracking module. Extensive automatic landing experiments with fixed-wing flight demonstrate that our infrared camera array system has the unique ability to guide the UAV landing safely and accurately in real time. Moreover, the measurement and control distance of our system is more than 1000 m. The experimental results also demonstrate that our system can be used for UAV automatic accurate landing in Global Position System (GPS)-denied environments.

  13. A Ground-Based Near Infrared Camera Array System for UAV Auto-Landing in GPS-Denied Environment.

    PubMed

    Yang, Tao; Li, Guangpo; Li, Jing; Zhang, Yanning; Zhang, Xiaoqiang; Zhang, Zhuoyue; Li, Zhi

    2016-01-01

    This paper proposes a novel infrared camera array guidance system with capability to track and provide real time position and speed of a fixed-wing Unmanned air vehicle (UAV) during a landing process. The system mainly include three novel parts: (1) Infrared camera array and near infrared laser lamp based cooperative long range optical imaging module; (2) Large scale outdoor camera array calibration module; and (3) Laser marker detection and 3D tracking module. Extensive automatic landing experiments with fixed-wing flight demonstrate that our infrared camera array system has the unique ability to guide the UAV landing safely and accurately in real time. Moreover, the measurement and control distance of our system is more than 1000 m. The experimental results also demonstrate that our system can be used for UAV automatic accurate landing in Global Position System (GPS)-denied environments. PMID:27589755

  14. High efficiency near diffraction-limited mid-infrared flat lenses based on metasurface reflectarrays.

    PubMed

    Zhang, Shuyan; Kim, Myoung-Hwan; Aieta, Francesco; She, Alan; Mansuripur, Tobias; Gabay, Ilan; Khorasaninejad, Mohammadreza; Rousso, David; Wang, Xiaojun; Troccoli, Mariano; Yu, Nanfang; Capasso, Federico

    2016-08-01

    We report the first demonstration of a mid-IR reflection-based flat lens with high efficiency and near diffraction-limited focusing. Focusing efficiency as high as 80%, in good agreement with simulations (83%), has been achieved at 45° incidence angle at λ = 4.6 μm. The off-axis geometry considerably simplifies the optical arrangement compared to the common geometry of normal incidence in reflection mode which requires beam splitters. Simulations show that the effects of incidence angle are small compared to parabolic mirrors with the same NA. The use of single-step photolithography allows large scale fabrication. Such a device is important in the development of compact telescopes, microscopes, and spectroscopic designs. PMID:27505769

  15. A compact "water-window" microscope with 60-nm spatial resolution based on a double stream gas-puff target and Fresnel zone plate optics

    NASA Astrophysics Data System (ADS)

    Wachulak, Przemyslaw; Torrisi, Alfio; Nawaz, Muhammad F.; Adjei, Daniel; Bartnik, Andrzej; Kostecki, Jerzy; Wegrzynski, Łukasz; Vondrová, Šárka; Turňová, Jana; Fok, Tomasz; Jančarek, Alexandr; Fiedorowicz, Henryk

    2015-05-01

    Radiation with shorter illumination wavelength allows for extension of the diffraction limit towards nanometer scale, which is a straightforward way to significantly improve a spatial resolution in photon based microscopes. Soft X-ray (SXR) radiation, from the so called "water window" spectral range, λ=2.3-4.4 nm, which is particularly suitable for biological imaging due to natural optical contrast, providing much better spatial resolution than one obtained with visible light microscopes. The high contrast is obtained because of selective absorption of radiation by carbon and water, being constituents of the biological samples. We present a desk-top system, capable of resolving 60 nm features in few seconds exposure time. We exploit the advantages of a compact, laser-plasma SXR source, based on a double stream nitrogen gas puff target, developed at the Institute of Optoelectronics, Military University of Technology. The source, emitting quasi-monochromatic, incoherent radiation, in the "water widow" spectral range at λ = 2.88 nm, is coupled with ellipsoidal, grazing incidence condenser and Fresnel zone plate objective. The construction of the microscope with some recent images of test and real samples will be presented and discussed.

  16. Research on the algorithm of infrared target detection based on the frame difference and background subtraction method

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Hui, Mei; Liu, Xiaohua; Wu, Yijian

    2015-09-01

    As an important branch of infrared imaging technology, infrared target tracking and detection has a very important scientific value and a wide range of applications in both military and civilian areas. For the infrared image which is characterized by low SNR and serious disturbance of background noise, an innovative and effective target detection algorithm is proposed in this paper, according to the correlation of moving target frame-to-frame and the irrelevance of noise in sequential images based on OpenCV. Firstly, since the temporal differencing and background subtraction are very complementary, we use a combined detection method of frame difference and background subtraction which is based on adaptive background updating. Results indicate that it is simple and can extract the foreground moving target from the video sequence stably. For the background updating mechanism continuously updating each pixel, we can detect the infrared moving target more accurately. It paves the way for eventually realizing real-time infrared target detection and tracking, when transplanting the algorithms on OpenCV to the DSP platform. Afterwards, we use the optimal thresholding arithmetic to segment image. It transforms the gray images to black-white images in order to provide a better condition for the image sequences detection. Finally, according to the relevance of moving objects between different frames and mathematical morphology processing, we can eliminate noise, decrease the area, and smooth region boundaries. Experimental results proves that our algorithm precisely achieve the purpose of rapid detection of small infrared target.

  17. Coherent near infrared photodetection with indium gallium arsenide based optoelectronic devices

    NASA Astrophysics Data System (ADS)

    Fu, Jun-Xian

    Over the extremely broad electromagnetic spectrum, the near-infrared region (0.7--3 mum) is of great interests to physicists, chemists and biologists. Coherent photo-detection in the near-infrared as well as visible and other wavelength regions is extremely useful in identifying coherent light sources from the noisy background. It has great potential to be applied to single-molecule detection by surface-enhanced coherent anti-Stokes Raman scattering. Other applications include chemical gas detection, remote sensing and environmental monitoring, semiconductor processing control and others. Indium gallium arsenide (InGaAs) based optoelectronic devices have been extensively investigated in the wavelength range extending from 800nm for gallium-rich material to 3mum for indium-rich material. A range of InGaAs alloys with bandgap energies in the near infrared wavelength range are investigated by solid-source molecular beam epitaxy (SSMBE). They include strain-free standard In0.532Ga0.468As and In0.532Ga0.468 AsNxSby lattice-matched to InP substrates, highly strained pseudomorphic InxGa1-xAs/InyGa 1-yAs quantum structures on InP substrates and relaxed metamorphic thick Inx>0.8Ga1-xAs device layers with cyclic arsenic-assisted in-situ annealed step-graded InAlAs buffer layers on GaAs and InP substrates. An InP/InAlAs/InGaAs heterojunction bipolar phototransistor (HPT) is designed, simulated and fabricated. The electrical and optical properties, such as responsivity and spectral response, of the HPT are characterized. A compact standing-wave Fourier-transform interferometer system capable of coherent detection in the near-infrared region is demonstrated. A new technique of identifying coherent light sources using harmonic Fourier spectra analysis is developed. The system only includes a PZT-controlled gold-coated scan mirror and a partial-transparent (3.8% single-path loss) InP/InAlAs/InGaAs HPT. The close-loop scan range of PZT-controlled mirror is 32mum. With such mirror

  18. Neonatal non-contact respiratory monitoring based on real-time infrared thermography

    PubMed Central

    2011-01-01

    Background Monitoring of vital parameters is an important topic in neonatal daily care. Progress in computational intelligence and medical sensors has facilitated the development of smart bedside monitors that can integrate multiple parameters into a single monitoring system. This paper describes non-contact monitoring of neonatal vital signals based on infrared thermography as a new biomedical engineering application. One signal of clinical interest is the spontaneous respiration rate of the neonate. It will be shown that the respiration rate of neonates can be monitored based on analysis of the anterior naris (nostrils) temperature profile associated with the inspiration and expiration phases successively. Objective The aim of this study is to develop and investigate a new non-contact respiration monitoring modality for neonatal intensive care unit (NICU) using infrared thermography imaging. This development includes subsequent image processing (region of interest (ROI) detection) and optimization. Moreover, it includes further optimization of this non-contact respiration monitoring to be considered as physiological measurement inside NICU wards. Results Continuous wavelet transformation based on Debauches wavelet function was applied to detect the breathing signal within an image stream. Respiration was successfully monitored based on a 0.3°C to 0.5°C temperature difference between the inspiration and expiration phases. Conclusions Although this method has been applied to adults before, this is the first time it was used in a newborn infant population inside the neonatal intensive care unit (NICU). The promising results suggest to include this technology into advanced NICU monitors. PMID:22243660

  19. Principal component analysis based interconversion between infrared and near-infrared spectra for the study of thermal-induced weak interaction changes of poly(N-isopropylacrylamide).

    PubMed

    Zhang, Liping; Noda, Isao; Wu, Yuqing

    2009-06-01

    The use of a novel spectral interconversion scheme, principal component analysis (PCA) based spectral prediction, to probe weak molecular interactions of a polymer film is reported. A PCA model is built based on a joint data matrix by concatenating two related spectral data matrices (such as infrared (IR) and near-infrared (NIR) spectra) along the variable direction, then the obtained loading matrix of the model is split into two parts to predict the desired spectra. For a better PCA-based prediction, it is suggested that the samples whose spectra are to be predicted should be as similar as possible to those used in the model. Based on the PCA model, the thermal-induced changes in the weak interaction of poly(N-isopropylacrylamide) (PNiPA) film is revealed by the interconversion between selected spectral ranges measured between 40 and 220 degrees C. The thermal-induced weak interaction changes of PNiPA, expressed as either the band shift or intensity changes at a specific region, have been probed properly. Meanwhile, the robustness of the spectral prediction is also compared with that achieved by a partial least squares (PLS2) model in detail, illustrating its advantages in predicting more subtle structural changes such as C-H groups.

  20. (Center of excellence: Microlaser microscope)

    SciTech Connect

    Webb, R.H.

    1992-01-01

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  1. Adaptive scene-based nonuniformity correction method for infrared-focal plane arrays

    NASA Astrophysics Data System (ADS)

    Torres, Sergio N.; Vera, Esteban M.; Reeves, Rodrigo A.; Sobarzo, Sergio K.

    2003-08-01

    The non-uniform response in infrared focal plane array (IRFPA) detectors produces corrupted images with a fixed-pattern noise. In this paper we present an enhanced adaptive scene-based non-uniformity correction (NUC) technique. The method simultaneously estimates detector's parameters and performs the non-uniformity compensation using a neural network approach. In addition, the proposed method doesn't make any assumption on the kind or amount of non-uniformity presented on the raw data. The strength and robustness of the proposed method relies in avoiding the presence of ghosting artifacts through the use of optimization techniques in the parameter estimation learning process, such as: momentum, regularization, and adaptive learning rate. The proposed method has been tested with video sequences of simulated and real infrared data taken with an InSb IRFPA, reaching high correction levels, reducing the fixed pattern noise, decreasing the ghosting, and obtaining an effective frame by frame adaptive estimation of each detector's gain and offset.

  2. Small moving infrared space target tracking algorithm based on probabilistic data association filter

    NASA Astrophysics Data System (ADS)

    Li, Zhengzhou; Chen, Jing; Gu, Yuanshan; Tang, Lan; Dai, Zhen; Fu, Hongxia; Li, Ruzhang; Liu, Changju; Jin, Gang

    2014-03-01

    Numerous false alarms for low signal-to-noise ratio (SNR) would seriously debase the performance for infrared low observable (LO) space target tracking. Due to the motion (i.e. azimuth, elevation and their derivative velocity), amplitude and size of infrared target are almost invariable and highly correlative, a multi-feature association approach based on probabilistic data association (PDA) is presented to track target in this paper. Firstly, the motion, amplitude and size of target are modeled as stationary random signal afforded Gaussian distribution. The probability of motion, amplitude and size of measurement originated as the target of interest is then estimated by Gaussian distribution, and that of false alarm is distributed uniformly. Subsequently, the combined probability of motion, amplitude and size is derived by PDA, and their weight coefficients are estimated adaptively according to their fluctuations. Finally, the relevant parameters including combination measurement are predicted and updated. Some experiments are included and the results show that the performance of target tracking by the proposed approach is significantly enhanced.

  3. A regional density distribution based wide dynamic range algorithm for infrared camera systems

    NASA Astrophysics Data System (ADS)

    Park, Gyuhee; Kim, Yongsung; Joung, Shichang; Shin, Sanghoon

    2014-10-01

    Forward Looking InfraRed (FLIR) imaging system has been widely used for both military and civilian purposes. Military applications include target acquisition and tracking, night vision system. Civilian applications include thermal efficiency analysis, short-ranged wireless communication, weather forecasting and other various applications. The dynamic range of FLIR imaging system is larger than one of commercial display. Generally, auto gain controlling and contrast enhancement algorithm are applied to FLIR imaging system. In IR imaging system, histogram equalization and plateau equalization is generally used for contrast enhancement. However, they have no solution about the excessive enhancing when luminance histogram has been distributed in specific narrow region. In this paper, we proposed a Regional Density Distribution based Wide Dynamic Range algorithm for Infrared Camera Systems. Depending on the way of implementation, the result of WDR is quite different. Our approach is single frame type WDR algorithm for enhancing the contrast of both dark and white detail without loss of bins of histogram with real-time processing. The significant change in luminance caused by conventional contrast enhancement methods may introduce luminance saturation and failure in object tracking. Proposed method guarantees both the effective enhancing in contrast and successive object tracking. Moreover, since proposed method does not using multiple images on WDR, computation complexity might be significantly reduced in software / hardware implementation. The experimental results show that proposed method has better performance compared with conventional Contrast enhancement methods.

  4. Adaptive non-uniformity correction method based on temperature for infrared detector array

    NASA Astrophysics Data System (ADS)

    Zhang, Zhijie; Yue, Song; Hong, Pu; Jia, Guowei; Lei, Bo

    2013-09-01

    The existence of non-uniformities in the responsitivity of the element array is a severe problem typical to common infrared detector. These non-uniformities result in a "curtain'' like fixed pattern noises (FPN) that appear in the image. Some random noise can be restrained by the method kind of equalization method. But the fixed pattern noise can only be removed by .non uniformity correction method. The produce of non uniformities of detector array is the combined action of infrared detector array, readout circuit, semiconductor device performance, the amplifier circuit and optical system. Conventional linear correction techniques require costly recalibration due to the drift of the detector or changes in temperature. Therefore, an adaptive non-uniformity method is needed to solve this problem. A lot factors including detectors and environment conditions variety are considered to analyze and conduct the cause of detector drift. Several experiments are designed to verify the guess. Based on the experiments, an adaptive non-uniformity correction method is put forward in this paper. The strength of this method lies in its simplicity and low computational complexity. Extensive experimental results demonstrate the disadvantage of traditional non-uniformity correct method is conquered by the proposed scheme.

  5. Titan's surface and troposphere, investigated with ground-based, near-infrared observations.

    PubMed

    Griffith, C A; Owen, T; Wagener, R

    1991-01-01

    New observations of Titan's near-infrared spectrum (4000-5000 cm-1) combined with points taken from Fink and Larson's (1979) spectrum (4000-12500 cm-1) provide information on Titan's haze, possible clouds, surface albedo, and atmospheric abundance of H2. In the near-infrared, the main features in Titan's spectrum result from absorption of solar radiation by CH4. The strength of this absorption varies considerably with wavelength, allowing us to probe various atmospheric levels down to the surface itself by choosing specific wavelengths for analysis. At 4715 cm-1, the pressure-induced S(1) fundamental band of H2 lies in the wings of CH4 bands. Based on current values for the CH4 line parameters, Titan's spectrum can be best interpreted with a volume mixing ratio of H2 between 0.5 and 1.0%. Our observations suggest the existence of an optically thin CH4 cloud layer. The optical depths that we derive for Titan's haze and clouds are small enough to allow us to sense the surface of Titan at 4900, 6250, and 7700 cm-1. The most plausible interpretation of the albedos determined at these wavenumbers suggests a surface dominated by "dirty" water ice. A global ethane ocean is not compatible with these albedos.

  6. Discrimination between two different grades of human glioma based on blood vessel infrared spectral imaging.

    PubMed

    Wehbe, Katia; Forfar, Isabelle; Eimer, Sandrine; Cinque, Gianfelice

    2015-09-01

    Gliomas are brain tumours classified into four grades with increasing malignancy from I to IV. The development and the progression of malignant glioma largely depend on the tumour vascularization. Due to their tissue heterogeneity, glioma cases can be difficult to classify into a specific grade using the gold standard of histological observation, hence the need to base classification on a quantitative and reliable analytical method for accurately grading the disease. Previous works focused specifically on vascularization study by Fourier transform infrared (FTIR) spectroscopy, proving this method to be a way forward to detect biochemical changes in the tumour tissue not detectable by visual techniques. In this project, we employed FTIR imaging using a focal plane array (FPA) detector and globar source to analyse large areas of glioma tumour tissue sections via molecular fingerprinting in view of helping to define markers of the tumour grade. Unsupervised multivariate analysis (hierarchical cluster analysis and principal component analysis) of blood vessel spectral data, retrieved from the FPA images, revealed the fine structure of the borderline between two areas identified by a pathologist as grades III and IV. Spectroscopic indicators are found capable of discriminating different areas in the tumour tissue and are proposed as biomolecular markers for potential future use of grading gliomas. Graphical Abstract Infrared imaging of glioma blood vessels provides a means to revise the pathologists' line of demarcation separating grade III (GIII) from grade IV (GIV) parts. PMID:26168973

  7. Infrared dim small target detection algorithm based on NSCT and SVD

    NASA Astrophysics Data System (ADS)

    Zhao, Ying; Liu, Gang; Zhou, Huixin; Qin, Hanlin; Li, Xiao; Wen, Zhigang; Ni, Man; Wang, Bingjian

    2015-10-01

    A novel dim small target detection algorithm based on the nonsubsampled contourlet transform (NSCT) and the singular value decomposition (SVD) is proposed in this paper, which is to improve the performance of the dim small target detection under the complex sky cloud background. Firstly, the original infrared image is decomposed with the SVD, and several different numbers of the singular value for reconstruction is chosen to analyze the application of the SVD to the image. The complex sky cloud background in the infrared target image is predicted by choosing a certain number of the singular value to reconstruct the image, and it is subtracted from the original image to suppress the background and enhance the target signal. Secondly, to use the scale and the direction information of the image, the residual image is decomposed by the NSCT into several high-pass directional subbands and a low-pass subband. Thirdly, the SVD filtering is utilized again to those directional subbands to eliminate the noise and the residual background. And the low-pass subband is modified by the local mean removal method. Finally, the refined subbands are reconstructed by the inverse NSCT to fulfill the dim small target detection. The experimental results demonstrate that the proposed algorithm has better subjective vision and objective numerical indicators, and can acquire a better performance of the target detection.

  8. Infrared thermography based defect detection in ferromagnetic specimens using a low frequency alternating magnetic field

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Bagavathiappan, S.; Soumya, C.; Mahendran, V.; Pillai, V. P. M.; Philip, John; Jayakumar, T.

    2014-05-01

    A new active infrared thermography based technique is proposed for defect detection in ferromagnetic specimens using a low frequency alternating magnetic field induced heating. The test specimens (four mild steel specimens with artificial rectangular slots of 8.0, 5.0, 3.3 and 3.0 mm depths) are magnetized using a low frequency alternating magnetic field and by using an infrared camera, the surface temperature is remotely monitored in real time. An alternating magnetic field induces an eddy current in the specimen which increases the specimen temperature due to the Joule's heating. The experimental results show a thermal contrast in the defective region that decays exponentially with the defect depth. The observed thermal contrast is attributed to the reduction in induction heating due to the leakage of magnetic flux caused by magnetic permeability gradient in the defective region. The proposed technique is suitable for rapid non-contact wide area inspection of ferromagnetic materials and offers several advantages over the conventional active thermography techniques like fast direct heating, no frequency optimization, no dependence on the surface absorption coefficient and penetration depth.

  9. Novel far infrared imaging sensor based on the use of titanium-nickel shape memory alloys

    NASA Astrophysics Data System (ADS)

    Ho, Ho-Pui; Chung, Jonathan C. Y.; Ng, Ki-Cheong; Cheng, K. L.; Wu, Shu-Yuen

    2002-11-01

    In this paper we describe a novel imaging sensor design1 that uses the thermo-mechanical properties of nickel-titanium (NiTi) shape memory alloys (SMAs) for detecting far infrared radiation (FIR). A thin NiTi SMA cantilever is coated with a FIR absorbing layer on one surface, while the other is coated with a highly reflecting metallic layers such as gold. Upon absorption of FIR, the temperature of the cantilever changes. This causes the tilt angle of the cantilever to change as well. The deflection is very large if the temperature change coincides with the temperature range of the phase transformation of the NiTi SMA. The detection of the mechanical movements in the cantilever is achieved by illuminating the reflective side using a visible laser beam. A Michelson interferometer is used to covert the reflected light into optical modulation. In doing this, very small displacement in the cantilever can be visualized as laser intensity variation. A single element device has been fabricated for this purpose and our initial experimental results have demonstrated the successful detection of FIR. An estimation of angular deflection per unit change of temperature suggests that our approach can offer sensitivity higher than the reported design based on the use of bi-material strips. We envisage that a two-dimensional array of such devices can lead to the possibility of realizing a practical low-cost infrared imaging device operating under room temperature conditions.

  10. Investigation of acousto-optic properties of tellurium-based glasses for infrared applications

    NASA Astrophysics Data System (ADS)

    Voloshinov, V. B.; Gupta, N.; Kulakova, L. A.; Khorkin, V. S.; Melekh, B. T.; Knyazev, G. A.

    2016-02-01

    We examined the physical properties of infrared optical glasses composed of tellurium, germanium, selenium, sulfur and silicon. In particular, we measured optical, acoustic and photoelastic parameters of the following alloy compounds: germanium-selenium-tellurium (Ge-Se-Te), germanium-selenium-sulfur-tellurium (Ge-Se-S-Te), germanium-silicon-tellurium (Ge-Si-Te) and silicon-tellurium (Si-Te). Like single-crystal tellurium, the glasses demonstrate good acousto-optic (AO) diffraction efficiency and have reasonable optical transparency in a wide spectral region covering wavelengths from 1.5 to 20 μm. The optical, acoustic and photoelastic properties of the tellurium-based compounds were measured using infrared lamp sources of radiation as well as He-Ne and CO2 lasers. In this paper, we report on the optical, acoustic and photoelastic parameters of a selection of these compounds and discuss the advantages and disadvantages of using these glasses for AO device applications. We also present the measured characteristics of an AO cell fabricated in a Si20Te80 glass material which exhibited high optical uniformity and long-term chemical stability.

  11. Infrared and visible image fusion based on region growing and contourlet transform

    NASA Astrophysics Data System (ADS)

    Zhao, Bingjie; Gao, Wei; Song, Zongxi

    2013-09-01

    According to the characteristics of infrared and visible images, a new image fusion method based on region growing and contourlet transform is proposed in this paper. To obtain more complementary information, the method is designed as a two-stage procedure. Firstly, the input infrared image is processed with region growing to segment the thermal target. Different fusion rules are adopted in target and background regions, respectively. For the target region, local energy is utilized as the fusion rule of the first fusion to fuse the thermal target and the visible image, while for the non-target region, we reserve the visible background information. Secondly, in order to fully add original information of the source images and avoid loss of information caused by segmentation, we make the second fusion between the visible image and the result image of the one-stage fusion. For good properties of localization, directionality and anisotropy, we adopt contourlet transform as the second fusion method. Experiments are carried out and the results show that our method is clearer in visual quality and effective in quantitative evaluations and the fused images are better than those resulting of using wavelet transform and contourlet transform.

  12. [Based on Trigger Sampling Method and Phase Correction of Infrared Spectrum Measurement Applications].

    PubMed

    Li, Yan; Gao, Min-guang; Xu, Liang; Li, Sheng; Li, Xiang-xian; Ye, Shu-bin; Liu, Jian-guo

    2015-07-01

    Fourier transform infrared spectrometer can be realized in high temperature flue gas multicomponent measurement at the same time, has wide application prospects in the field. And one of the important factors to determine the success of application, lies in the measuring system of infrared interference figure sampling phase error control. This paper discusses the main-reasons of the appearance of phase error in the system, through the analysis of Helium-neon laser interference signal zero uniformity, illustrates the produce phase error is the main reason of the laser signal and reference signal phase difference. At the meantime, the quantitative analysis of the phase error influence on instrument signal to noise ratio (SNR), also the Mertz phase correction method for the instrument improves the thousands of times of the original signal to noise ratio. And the related experiment, the experimental results show that the system based on the interference figure sampling method satisfy the needs of high temperature flue gas measurements. PMID:26717778

  13. Adaptive contour-based statistical background subtraction method for moving target detection in infrared video sequences

    NASA Astrophysics Data System (ADS)

    Akula, Aparna; Khanna, Nidhi; Ghosh, Ripul; Kumar, Satish; Das, Amitava; Sardana, H. K.

    2014-03-01

    A robust contour-based statistical background subtraction method for detection of non-uniform thermal targets in infrared imagery is presented. The foremost step of the method comprises of generation of background frame using statistical information of an initial set of frames not containing any targets. The generated background frame is made adaptive by continuously updating the background using the motion information of the scene. The background subtraction method followed by a clutter rejection stage ensure the detection of foreground objects. The next step comprises of detection of contours and distinguishing the target boundaries from the noisy background. This is achieved by using the Canny edge detector that extracts the contours followed by a k-means clustering approach to differentiate the object contour from the background contours. The post processing step comprises of morphological edge linking approach to close any broken contours and finally flood fill is performed to generate the silhouettes of moving targets. This method is validated on infrared video data consisting of a variety of moving targets. Experimental results demonstrate a high detection rate with minimal false alarms establishing the robustness of the proposed method.

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

    PubMed

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

    2013-12-01

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

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

    SciTech Connect

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

    2013-12-15

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

  16. Variation of phytoplankton assemblages of Kongsfjorden in early autumn 2012: a microscopic and pigment ratio-based assessment.

    PubMed

    Bhaskar, Jane T; Tripathy, S C; Sabu, P; Laluraj, C M; Rajan, S

    2016-04-01

    Phytoplankton species distribution and composition were determined by using microscopy and pigment ratios in the Kongsfjorden during early autumn 2012. Variation in sea surface temperature (SST) was minimal and matched well with satellite-derived SST. Nutrients were generally limited. Surface phytoplankton abundance ranged from 0.21 × 10(3) to 10.28 × 10(3) cells L(-1). Phytoplankton abundance decreased with depth and did not show any significant correlation with chlorophyll a (chl a). Column-integrated phytoplankton cell counts (PCC) ranged from 94.3 × 10(6) cells m(-2) (Kf4) to 13.7 × 10(6) cells m(-2) (Kf5), while chl a was lowest at inner part of the fjord (6.3 mg m(-2)) and highest towards the mouth (24.83 mg m(-2)). Biomass from prymnesiophytes and raphidophytes dominated at surface and 10 m, respectively. The contribution of Bacillariophyceae to biomass was low. Generally, heterotrophic dinoflagellates were great in abundance (12.82 %) and ubiquitous in nature and were major contributors to biomass. Various chl pigments (chl b, chl c, phaeopigments (phaeo)) were measured to obtain pigment/chl a ratios to ascertain phytoplankton composition. Phaeo were observed only in inner fjord. Chl b:a ratios and microscopic observations indicated dominance of Chlorophyceae at greater depths than surface. Furthermore, microscopic observations confirmed dominance of chl c containing algae throughout the fjord. The study indicates that pigment ratios can be used as a tool for preliminary identification of major phytoplankton groups. However, under the presence of a large number of heterotrophic dinoflagellates such as Gymnodinium sp. and Gyrodinium sp., pigment signatures need to be supplemented by microscopic observations.

  17. C-V measurements of micron diameter metal-oxide-semiconductor capacitors using a scanning-electron-microscope-based nanoprobe.

    PubMed

    Zheng, T; Jia, H; Wallace, R M; Gnade, B E

    2007-10-01

    The C-V electrical characterization of microstructures on a standard probe station is limited by the magnification of the imaging system and the precision of the probe manipulators. To overcome these limitations, we examine the combination of in situ electrical probing and a dual column scanning electron microscope/focused ion beam system. The imaging parameters and probing procedures are carefully chosen to reduce e-beam damage to the metal oxide semiconductor capacitor device under test. Estimation of shunt capacitance is critical when making femtofarad level measurements. C-V measurements of micron size metal-oxide-silicon capacitors are demonstrated. PMID:17979444

  18. The Scanning Optical Microscope.

    ERIC Educational Resources Information Center

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  19. A single-cell scraper based on an atomic force microscope for detaching a living cell from a substrate

    SciTech Connect

    Iwata, Futoshi; Adachi, Makoto; Hashimoto, Shigetaka

    2015-10-07

    We describe an atomic force microscope (AFM) manipulator that can detach a single, living adhesion cell from its substrate without compromising the cell's viability. The micrometer-scale cell scraper designed for this purpose was fabricated from an AFM micro cantilever using focused ion beam milling. The homemade AFM equipped with the scraper was compact and standalone and could be mounted on a sample stage of an inverted optical microscope. It was possible to move the scraper using selectable modes of operation, either a manual mode with a haptic device or a computer-controlled mode. The viability of the scraped single cells was evaluated using a fluorescence dye of calcein-acetoxymethl ester. Single cells detached from the substrate were collected by aspiration into a micropipette capillary glass using an electro-osmotic pump. As a demonstration, single HeLa cells were selectively detached from the substrate and collected by the micropipette. It was possible to recultivate HeLa cells from the single cells collected using the system.

  20. A new method based on Adaptive Discrete Wavelet Entropy Energy and Neural Network Classifier (ADWEENN) for recognition of urine cells from microscopic images independent of rotation and scaling.

    PubMed

    Avci, Derya; Leblebicioglu, Mehmet Kemal; Poyraz, Mustafa; Dogantekin, Esin

    2014-02-01

    So far, analysis and classification of urine cells number has become an important topic for medical diagnosis of some diseases. Therefore, in this study, we suggest a new technique based on Adaptive Discrete Wavelet Entropy Energy and Neural Network Classifier (ADWEENN) for Recognition of Urine Cells from Microscopic Images Independent of Rotation and Scaling. Some digital image processing methods such as noise reduction, contrast enhancement, segmentation, and morphological process are used for feature extraction stage of this ADWEENN in this study. Nowadays, the image processing and pattern recognition topics have come into prominence. The image processing concludes operation and design of systems that recognize patterns in data sets. In the past years, very difficulty in classification of microscopic images was the deficiency of enough methods to characterize. Lately, it is seen that, multi-resolution image analysis methods such as Gabor filters, discrete wavelet decompositions are superior to other classic methods for analysis of these microscopic images. In this study, the structure of the ADWEENN method composes of four stages. These are preprocessing stage, feature extraction stage, classification stage and testing stage. The Discrete Wavelet Transform (DWT) and adaptive wavelet entropy and energy is used for adaptive feature extraction in feature extraction stage to strengthen the premium features of the Artificial Neural Network (ANN) classifier in this study. Efficiency of the developed ADWEENN method was tested showing that an avarage of 97.58% recognition succes was obtained.

  1. Fabrication of large area plasmonic nanoparticle grating structure on silver halide based transmission electron microscope film and its application as a surface enhanced Raman spectroscopy substrate

    SciTech Connect

    Sudheer, Tiwari, P.; Singh, M. N.; Sinha, A. K.; Rai, V. N.; Srivastava, A. K.; Bhartiya, S.; Mukherjee, C.

    2015-08-14

    The plasmonic responses of silver nanoparticle grating structures of different periods made on silver halide based electron microscope film are investigated. Raster scan of the conventional scanning electron microscope (SEM) is used to carry out electron beam lithography for fabricating the plasmonic nanoparticle grating (PNG) structures. Morphological characterization of the PNG structures, carried out by the SEM and the atomic force microscope, indicates that the depth of the groove decreases with a decrease in the grating period. Elemental characterization performed by the energy dispersive spectroscopy and the x-ray diffraction shows the presence of nanoparticles of silver in the PNG grating. The optical characterization of the gratings shows that the localized surface plasmon resonance peak shifts from 366 to 378 nm and broadens with a decrease in grating period from 10 to 2.5 μm. The surface enhanced Raman spectroscopy of the Rhodamine-6G dye coated PNG structure shows the maximum enhancement by two orders of magnitude in comparison to the randomly distributed silver nanoparticles having similar size and shape as the PNG structure.

  2. TEAM Electron Microscope Animation

    SciTech Connect

    2012-01-01

    The TEAM Electron Microscope, a device that enables atomic-scale imaging in 3-D, has a rotating stage that can hold and position samples inside electron microscopes with unprecedented stability, position-control accuracy, and range of motion.The TEAM Stage makes one of the world's most powerful electron microscopes even better, and enables previously impossible experiments.

  3. Novel InP- and GaSb-based light sources for the near to far infrared

    NASA Astrophysics Data System (ADS)

    Stephan, Sprengel; Frederic, Demmerle; Markus-Christian, Amann

    2016-11-01

    This topical review presents an overview on novel concepts for light emitting diodes (LEDs) and lasers for the near infrared to the THz regime. GaSb-based quantum well lasers are shown to be a promising concept for laser from the near to mid infrared. The GaSb-based edge-emitting lasers offer low thresholds for wavelengths ranging from about 2 to 3.7 μm. However, the development of vertical-cavity surface-emitting lasers and other advanced laser concepts is lagging behind due to material issues and complicated process technology. InP-based type-II quantum wells are an innovative concept for sources emitting in the wavelength range from 2 to 4 μm. This concept combines extended long wavelength emission with the reliable process technology of the already well-established InP-based lasers. Based on this, we present LEDs up to 3.5 μm wavelength, surface emitting lasers at 2.5 μm wavelength and edge emitting lasers up to 2.7 μm. For longer wavelengths, the so-called GaSb- and InAs-based interband cascade lasers can be used operating up to about 7 μm. The mid infrared range between 3 and 20 μm is also covered by quantum cascade lasers (QCL), which are dominating especially in the longer wavelength range above 7 μm. The far infrared reaching to the THz regime is exclusively covered by QCL. While for decades the only available semiconductor laser source for the far infrared and THz range was the direct THz QCL, recent progress demonstrated THz emission in nonlinear mid infrared QCLs. These devices are emitting THz by a nonlinear frequency conversion process, which allows operation at room temperature and beyond. Tunable THz lasers were demonstrated using both monolithic tuning mechanisms and an external cavity approach.

  4. High dynamic solutions for short-wavelength infrared imaging based on InGaAs

    NASA Astrophysics Data System (ADS)

    Reverchon, Jean-Luc; Decobert, Jean; Djedidi, Anis; Gentner, Jean-Louis; Huet, Odile; Lagay, Nadine; Rouvié, Anne; Robo, Jean-Alexandre; Truffer, Jean-Patrick; Costard, Eric; Ni, Yang; Arion, Bogdan; Zhu, Yiming; Potet, Pierre

    2011-06-01

    Short-wavelength infrared image sensors based on p-i-n photodiode arrays present a tremendous interest in applications such as passive and active imagery for laser detection/warning, hot spot or detection for lasers sensors, enhanced vision systems or low light level sensors. The capability to work at room temperature with dark current equivalent to silicon-based devices is another motivation for the fast development of this technology. This paper presents several modules and camera based on InGaAs photodiode arrays from the III-VLab. First, we describe the electro-optics performance in terms of dark signal, sensitivity, and particularly the visible extension capability. We also present a nucless logarithmic sensor based on a 1/2 video graphics array (VGA) format at a pitch of 25 μm initially designed for visible CMOS camera chip. We will also present the next generation of focal plane arrays based on a VGA format of 640×512 pixels with a pitch of 15 μm. This array will be associated to a CTIA readout circuit and also to an innovative CMOS logarithmic wide dynamic range ROIC, developed by New Imaging Technologies. This VGA logarithmic device developed for automotive safety will involve visible extension capability in a European project named 2Wide_sense.

  5. Improving Agricultural Water Resources Management Using Ground-based Infrared Thermometry

    NASA Astrophysics Data System (ADS)

    Taghvaeian, S.

    2014-12-01

    Irrigated agriculture is the largest user of freshwater resources in arid/semi-arid parts of the world. Meeting rapidly growing demands in food, feed, fiber, and fuel while minimizing environmental pollution under a changing climate requires significant improvements in agricultural water management and irrigation scheduling. Although recent advances in remote sensing techniques and hydrological modeling has provided valuable information on agricultural water resources and their management, real improvements will only occur if farmers, the decision makers on the ground, are provided with simple, affordable, and practical tools to schedule irrigation events. This presentation reviews efforts in developing methods based on ground-based infrared thermometry and thermography for day-to-day management of irrigation systems. The results of research studies conducted in Colorado and Oklahoma show that ground-based remote sensing methods can be used effectively in quantifying water stress and consequently triggering irrigation events. Crop water use estimates based on stress indices have also showed to be in good agreement with estimates based on other methods (e.g. surface energy balance, root zone soil water balance, etc.). Major challenges toward the adoption of this approach by agricultural producers include the reduced accuracy under cloudy and humid conditions and its inability to forecast irrigation date, which is a critical knowledge since many irrigators need to decide about irrigations a few days in advance.

  6. A method based on infrared detection for determining the moisture content of ceramic plaster materials.

    PubMed

    Macias-Melo, E V; Aguilar-Castro, K M; Alvarez-Lemus, M A; Flores-Prieto, J J

    2015-09-01

    In this work, we describe a methodology for developing a mathematical model based on infrared (IR) detection to determine the moisture content (M) in solid samples. For this purpose, an experimental setup was designed, developed and calibrated against the gravimetric method. The experimental arrangement allowed for the simultaneous measurement of M and the electromotive force (EMF), fitting the experimental variables as much as possible. These variables were correlated by a mathematical model, and the obtained correlation was M=1.12×exp(3.47×EMF), ±2.54%. This finding suggests that it is feasible to measure the moisture content when it has greater values than 2.54%. The proposed methodology could be used for different conditions of temperature, relative humidity and drying rates to evaluate the influence of these variables on the amount of energy received by the IR detector.

  7. Reanalysis of the Near-infrared Extragalactic Background Light Based on the IRTS Observations

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  8. Sediment mineralogy based on visible and near-infrared reflectance spectroscopy

    USGS Publications Warehouse

    Jarrard, R.D.; Vanden Berg, M.D.; ,

    2006-01-01

    Visible and near-infrared spectroscopy (VNIS) can be used to measure reflectance spectra (wavelength 350-2500 nm) for sediment cores and samples. A local ground-truth calibration of spectral features to mineral percentages is calculated by measuring reflectance spectra for a suite of samples of known mineralogy. This approach has been tested on powders, core plugs and split cores, and we conclude that it works well on all three, unless pore water is present. Initial VNIS studies have concentrated on determination of relative proportions of carbonate, opal, smectite and illite in equatorial Pacific sediments. Shipboard VNIS-based determination of these four components was demonstrated on Ocean Drilling Program Leg 199. ?? The Geological Society of London 2006.

  9. REANALYSIS OF THE NEAR-INFRARED EXTRAGALACTIC BACKGROUND LIGHT BASED ON THE IRTS OBSERVATIONS

    SciTech Connect

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  10. Multispectral imaging in the extended near-infrared window based on endogenous chromophores

    PubMed Central

    Cao, Qian; Zhegalova, Natalia G.; Wang, Steven T.; Akers, Walter J.

    2013-01-01

    Abstract. To minimize the problem with scattering in deep tissues while increasing the penetration depth, we explored the feasibility of imaging in the relatively unexplored extended near infrared (exNIR) spectral region at 900 to 1400 nm with endogenous chromophores. This region, also known as the second NIR window, is weakly dominated by absorption from water and lipids and is free from other endogenous chromophores with virtually no autofluorescence. To demonstrate the applicability of the exNIR for bioimaging, we analyzed the optical properties of individual components and biological tissues using an InGaAs spectrophotometer and a multispectral InGaAs scanning imager featuring transmission geometry. Based on the differences in spectral properties of tissues, we utilized ratiometric approaches to extract spectral characteristics from the acquired three-dimensional “datacube”. The obtained images of an exNIR transmission through a mouse head revealed sufficient details consistent with anatomical structures. PMID:23933967

  11. A novel sensor system for 3D face scanning based on infrared coded light

    NASA Astrophysics Data System (ADS)

    Modrow, Daniel; Laloni, Claudio; Doemens, Guenter; Rigoll, Gerhard

    2008-02-01

    In this paper we present a novel sensor system for three-dimensional face scanning applications. Its operating principle is based on active triangulation with a color coded light approach. As it is implemented in the near infrared band, the used light is invisible for human perception. Though the proposed sensor is primarily designed for face scanning and biometric applications, its performance characteristics are beneficial for technical applications as well. The acquisition of 3d data is real-time capable, provides accurate and high resolution depthmaps and shows high robustness against ambient light. Hence most of the limiting factors of other sensors for 3d and face scanning applications are eliminated, such as blinding and annoying light patterns, motion constraints and highly restricted scenarios due to ambient light constraints.

  12. High efficiency near diffraction-limited mid-infrared flat lenses based on metasurface reflectarrays

    NASA Astrophysics Data System (ADS)

    Zhang, Shuyan; Kim, Myoung-Hwan; Aieta, Francesco; She, Alan; Mansuripur, Tobias; Gabay, Ilan; Khorasaninejad, Mohammadreza; Rousso, David; Wang, Xiaojun; Troccoli, Mariano; Yu, Nanfang; Capasso, Federico

    2016-08-01

    A limiting factor in the development of mid-infrared optics is the lack of abundant materials that are transparent, low cost, lightweight, and easy to machine. In this paper, we demonstrate a metasurface device that circumvents these limitations. A flat lens based on antenna reflectarrays was designed to achieve near diffraction-limited focusing with a high efficiency (experiment: 80%, simulation: 83%) at 45(o) incidence angle at {\\lambda} = 4.6 {\\mu}m. This geometry considerably simplifies the experimental arrangement compared to the common geometry of normal incidence which requires beam splitters. Simulations show that the effect of comatic aberrations is small compared to parabolic mirrors. The use of single-step photolithography allows large scale fabrication.

  13. Infrared marker-based tracking in an indoor unknown environment for augmented reality applications

    NASA Astrophysics Data System (ADS)

    Huang, Yetao; Weng, Dongdong; Liu, Yue; Wang, Yongtian

    2009-11-01

    Marker based tracking requires complicated preparation work that impedes its use in augmented reality applications. This paper presents a novel tracking scheme to be used in an indoor unknown scene by adapting simultaneous localization and mapping (SLAM) algorithms. An infrared (IR) marker system is specifically designed to simplify the feature recognition and tracking in SLAM process. With one initial IR marker, the other markers can be projected randomly onto a large-area environment. The pose of camera can be estimated with a monocular IR camera in real time. Experimental result demonstrates that the proposed system meets the requirements of accuracy for large-area tracking. A prototype system is built to show its feasibility in unknown environment and potential use in applications.

  14. Reaction monitoring using mid-infrared laser-based vibrational circular dichroism.

    PubMed

    Rüther, Anja; Pfeifer, Marcel; Lórenz-Fonfría, Víctor A; Lüdeke, Steffen

    2014-09-01

    Changes in vibrational circular dichroism (VCD) were recorded on-line during a chemical reaction. The chiral complex nickel-(-)-sparteine chloride was hydrolyzed to free (-)-sparteine base in a biphasic system of sodium hydroxide solution and chloroform (CHCl(3)). Infrared (IR) and VCD spectra were iteratively recorded after pumping a sample from the CHCl(3) phase through a lab-built VCD spectrometer equipped with a tunable mid-IR quantum cascade laser light source, which allows for VCD measurements even in the presence of strongly absorbing backgrounds. Time-dependent VCD spectra were analyzed by singular value decomposition and global exponential fitting. Spectral features corresponding to the complex and free (-)-sparteine could be clearly identified in the fitted amplitude spectrum, which was associated with an exponential decay with an apparent time constant of 127 min (t(½) = 88 min).

  15. A method based on infrared detection for determining the moisture content of ceramic plaster materials.

    PubMed

    Macias-Melo, E V; Aguilar-Castro, K M; Alvarez-Lemus, M A; Flores-Prieto, J J

    2015-09-01

    In this work, we describe a methodology for developing a mathematical model based on infrared (IR) detection to determine the moisture content (M) in solid samples. For this purpose, an experimental setup was designed, developed and calibrated against the gravimetric method. The experimental arrangement allowed for the simultaneous measurement of M and the electromotive force (EMF), fitting the experimental variables as much as possible. These variables were correlated by a mathematical model, and the obtained correlation was M=1.12×exp(3.47×EMF), ±2.54%. This finding suggests that it is feasible to measure the moisture content when it has greater values than 2.54%. The proposed methodology could be used for different conditions of temperature, relative humidity and drying rates to evaluate the influence of these variables on the amount of energy received by the IR detector. PMID:25887842

  16. [Local Regression Algorithm Based on Net Analyte Signal and Its Application in Near Infrared Spectral Analysis].

    PubMed

    Zhang, Hong-guang; Lu, Jian-gang

    2016-02-01

    Abstract To overcome the problems of significant difference among samples and nonlinearity between the property and spectra of samples in spectral quantitative analysis, a local regression algorithm is proposed in this paper. In this algorithm, net signal analysis method(NAS) was firstly used to obtain the net analyte signal of the calibration samples and unknown samples, then the Euclidean distance between net analyte signal of the sample and net analyte signal of calibration samples was calculated and utilized as similarity index. According to the defined similarity index, the local calibration sets were individually selected for each unknown sample. Finally, a local PLS regression model was built on each local calibration sets for each unknown sample. The proposed method was applied to a set of near infrared spectra of meat samples. The results demonstrate that the prediction precision and model complexity of the proposed method are superior to global PLS regression method and conventional local regression algorithm based on spectral Euclidean distance.

  17. An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements

    NASA Astrophysics Data System (ADS)

    Dammers, Enrico; Palm, Mathias; Van Damme, Martin; Vigouroux, Corinne; Smale, Dan; Conway, Stephanie; Toon, Geoffrey C.; Jones, Nicholas; Nussbaumer, Eric; Warneke, Thorsten; Petri, Christof; Clarisse, Lieven; Clerbaux, Cathy; Hermans, Christian; Lutsch, Erik; Strong, Kim; Hannigan, James W.; Nakajima, Hideaki; Morino, Isamu; Herrera, Beatriz; Stremme, Wolfgang; Grutter, Michel; Schaap, Martijn; Wichink Kruit, Roy J.; Notholt, Justus; Coheur, Pierre-F.; Erisman, Jan Willem

    2016-08-01

    Global distributions of atmospheric ammonia (NH3) measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI) contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-)daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR) observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC) stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs = 547) give a mean relative difference of -32.4 ± (56.3) %, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (-50 to +100 %).

  18. An infrared-visible image fusion scheme based on NSCT and compressed sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Qiong; Maldague, Xavier

    2015-05-01

    Image fusion, as a research hot point nowadays in the field of infrared computer vision, has been developed utilizing different varieties of methods. Traditional image fusion algorithms are inclined to bring problems, such as data storage shortage and computational complexity increase, etc. Compressed sensing (CS) uses sparse sampling without knowing the priori knowledge and greatly reconstructs the image, which reduces the cost and complexity of image processing. In this paper, an advanced compressed sensing image fusion algorithm based on non-subsampled contourlet transform (NSCT) is proposed. NSCT provides better sparsity than the wavelet transform in image representation. Throughout the NSCT decomposition, the low-frequency and high-frequency coefficients can be obtained respectively. For the fusion processing of low-frequency coefficients of infrared and visible images , the adaptive regional energy weighting rule is utilized. Thus only the high-frequency coefficients are specially measured. Here we use sparse representation and random projection to obtain the required values of high-frequency coefficients, afterwards, the coefficients of each image block can be fused via the absolute maximum selection rule and/or the regional standard deviation rule. In the reconstruction of the compressive sampling results, a gradient-based iterative algorithm and the total variation (TV) method are employed to recover the high-frequency coefficients. Eventually, the fused image is recovered by inverse NSCT. Both the visual effects and the numerical computation results after experiments indicate that the presented approach achieves much higher quality of image fusion, accelerates the calculations, enhances various targets and extracts more useful information.

  19. An instrumentation amplifier based readout circuit for a dual element microbolometer infrared detector

    NASA Astrophysics Data System (ADS)

    de Waal, D. J.; Schoeman, J.

    2014-06-01

    The infrared band is widely used in many applications to solve problems stretching over very diverse fields, ranging from medical applications like inflammation detection to military, security and safety applications employing thermal imaging in low light conditions. At the heart of these optoelectrical systems lies a sensor used to detect incident infrared radiation, and in the case of this work our focus is on uncooled microbolometers as thermal detectors. Microbolometer based thermal detectors are limited in sensitivity by various parameters, including the detector layout and design, operating temperature, air pressure and biasing that causes self heating. Traditional microbolometers use the entire membrane surface for a single detector material. This work presents the design of a readout circuit amplifier where a dual detector element microbolometer is used, rather than the traditional single element. The concept to be investigated is based on the principle that both elements will be stimulated with a similar incoming IR signal and experience the same resistive change, thus creating a common mode signal. However, such a common mode signal will be rejected by a differential amplifier, thus one element is placed within a negative resistance converter to create a differential mode signal that is twice the magnitude of the comparable single mode signal of traditional detector designs. An instrumentation amplifier is used for the final stage of the readout amplifier circuit, as it allows for very high common mode rejection with proper trimming of the Wheatstone bridge to compensate for manufacturing tolerance. It was found that by implementing the above, improved sensitivity can be achieved.

  20. In vivo continuous glucose monitoring using a chip based near infrared sensor

    NASA Astrophysics Data System (ADS)

    Ben Mohammadi, L.; Sigloch, S.; Frese, I.; Welzel, K.; Göddel, M.; Klotzbücher, T.

    2014-05-01

    Diabetes is a serious health condition considered to be one of the major healthcare epidemics of modern era. An effective treatment of this disease can be only achieved by reliable continuous information on blood glucose levels. In this work we present a minimally invasive, chip-based near infrared (NIR) sensor, combined with microdialysis, for continuous glucose monitoring (CGM). The sensor principle is based on difference absorption spectroscopy in the 1st overtone band of the near infrared spectrum. The device features a multi-emitter LED and InGaAs-Photodiodes, which are located on a single electronic board (non-disposable part), connected to a personal computer via Bluetooth. The disposable part consists of a chip containing the fluidic connections for microdialysis, two fluidic channels acting as optical transmission cells and total internally reflecting mirrors for in- and out-coupling of the LED light to the chip and to the detectors. The sensor is combined with an intraveneous microdialysis to separate the glucose from the cells and proteins in the blood and operates without any chemical consumption. In vitro measurements showed a linear relationship between glucose concentration and the integrated difference signal with a coefficient of determination of 99 % in the relevant physiological concentration range from 0 to 400 mg/dl. In vivo measurements on 10 patients showed that the NIR-CGM sensor data reflects the blood reference values adequately, if a proper calibration and signal drift compensation is applied. The MARE (mean absolute relative error) value taken over all patient data is 13.8 %. The best achieved MARE value is at 4.8 %, whereas the worst is 25.8 %, with a standard deviation of 5.5 %.